Elsevier BV Acta Medica Okayama 2211-7156 18 2025 Development of FTase inhibitors inspired by the structures of andrastins 102828 EN Fumino Kitamura Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama Masaru Tanioka Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama Ayano Kosaka Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama Nao Matsuzawa Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama Takayuki Obita Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama Yuko Sakajiri Tomokazu Shibata Department of Complex Systems Science, Graduate School of Informatics, Nagoya University Ryusuke Sawada Department of Pharmacology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Takeshi Yokoyama Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama Aki Kohyama Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama Tsuyoshi Yamada Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama Yoshihiro Yamanishi Department of Complex Systems Science, Graduate School of Informatics, Nagoya University Mineyuki Mizuguchi Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama Yuji Matsuya Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama We designed and synthesized structurally simple farnesyl transferase (FTase) inhibitors (1a–1d) by leveraging andrastin, a natural product with FTase inhibitory activity. 1a–1d possess a cyclopentane-1,3-dione core, which is critical for FTase recognition; a farnesyl moiety, which is a simplified motif of A to C rings of andrastin; and a carboxylic acid or methoxycarbonyl group, which enables multipoint hydrogen bonding interactions with FTase. Competitive inhibition experiments revealed that 1d has the most potent FTase inhibitory activity. Docking simulation analysis of 1a–1d with FTase suggested that the multipoint hydrogen bonding interactions between the cyclopentane-1,3-dione moiety and the carboxyl group play an important role in FTase recognition. No potential conflict of interest relevant to this article was reported.

MDPI AG Acta Medica Okayama 2218-273X 16 2 2026 Targeting the Gut in Sepsis: Therapeutic Potential of Medical Gases 199 EN Tetsuya Yumoto Department of Emergency, Critical Care, and Disaster Medicine, Faculty of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University Takafumi Obara Department of Emergency, Critical Care, and Disaster Medicine, Faculty of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University Hiromichi Naito Department of Emergency, Critical Care, and Disaster Medicine, Faculty of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University Atsunori Nakao Department of Emergency, Critical Care, and Disaster Medicine, Faculty of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University Sepsis is a life-threatening condition characterized by a dysregulated host response to infection, often resulting in multiorgan dysfunction. Among affected systems, the gastrointestinal tract plays a central role in sepsis progression by promoting systemic inflammation through impaired barrier function, immune imbalance, and microbiome alterations. Recent research has identified selected medical gases and gasotransmitters as promising therapeutic candidates for preserving gut integrity in sepsis. In particular, hydrogen, carbon monoxide, and hydrogen sulfide exhibit antioxidative, anti-inflammatory, and cytoprotective properties. These gases act through defined molecular pathways, including activation of Nrf2, inhibition of NF-κB, and preservation of tight junction integrity, thereby supporting intestinal barrier function. In addition, they influence immune cell phenotypes and autophagy, with indirect effects on the gut microbiome. Although most supporting evidence derives from preclinical models, translational findings and emerging safety data highlight the potential of gut-targeted gas-based strategies. This review summarizes current mechanistic and translational evidence for gut-protective medical gases in sepsis and discusses their integration into future organ-specific and mechanism-based therapeutic approaches. No potential conflict of interest relevant to this article was reported.

Wiley Acta Medica Okayama 0385-5600 2026 Overexpression of Escherichia coli yaiX Confers Multidrug Resistance and Enhances Virulence in the Silkworm Infection Model EN Kinuka Hongu Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Kazuya Ishikawa Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Tomoki Kosaki Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Shin‐Ichi Miyoshi Research Center for Intestinal Health Science, Okayama University Kazuyuki Furuta Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Chikara Kaito Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University The emergence of bacteria with both antimicrobial resistance and high virulence has become a global health concern, underscoring the urgent need to elucidate the molecular basis underlying these traits. Here, we employed the silkworm (Bombyx mori) infection model, which is suitable for high-throughput screening, together with an Escherichia coli library containing plasmid clones of all genes from strain W3110, to identify genes whose overexpression enhances virulence. We found that overexpression of the uncharacterized protein YaiX promoted bacterial proliferation in silkworms and increased host lethality. Compared with the empty-vector control, the YaiX-overexpressing strain exhibited resistance to multiple antimicrobial agents with diverse mechanisms of action, including β-lactams, tetracyclines, fluoroquinolones, aminoglycosides, cationic surfactants, and hydrogen peroxide. Sequence analysis revealed that amino acids 18–52 of YaiX contain a transferase hexapeptide domain predicted to form a left-handed parallel β-helix. Overexpression of YaiX mutants lacking regions outside this domain conferred ampicillin resistance, whereas deletion of the hexapeptide domain abolished this phenotype. RNA sequencing and GO enrichment analyses further indicated that YaiX overexpression altered the expression of genes encoding RNA-binding proteins and porins. These findings suggest that YaiX overexpression, through its hexapeptide domain, modulates gene expression and contributes to both multidrug resistance and enhanced virulence in E. coli. No potential conflict of interest relevant to this article was reported.

Elsevier BV Acta Medica Okayama 1349-0079 68 1 2026 Insights into the taste of organic acids via TAS1Rs 100731 EN Yuko Yamase Department of Dental Anesthesiology and Special Care Dentistry, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Katsuki Takebe Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Kengo Horie Department of Oral Physiology, Graduate School of Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Yoshihiro Mitoh Department of Oral Physiology, Graduate School of Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Atsuko Yamashita Institute for Protein Research, The University of Osaka Ryusuke Yoshida Department of Oral Physiology, Graduate School of Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Objectives: Organic acids contribute significantly to the flavor of fermented foods by imparting sourness. Although mice generally avoid sour taste, previous studies have reported greater consumption of l-lactic acid than its d-enantiomer, suggesting enantiomer-specific recognition. This behavior is hypothesized to involve TAS1Rs, which consists of sweet/umami receptors. However, it remains unclear whether TAS1Rs additionally contribute to the recognition of other chiral organic acids. This study aimed to evaluate the role of TAS1Rs, particularly TAS1R3, in the modulation of enantiomer-dependent behavioral responses to organic acids in mice.<br> Methods: Behavioral responses were evaluated using 48-h and 1-h 2-bottle tests. Binding of organic acids to TAS1Rs was investigated by differential scanning fluorimetry (DSF) with the ligand-binding domain (LBD) of medaka Tas1r2a/Tas1r3.<br> Results: Wild-type mice consumed more d-malic acid than l-malic acid in the 48-h test, whereas Tas1r3-KO mice showed no such difference. This pattern was not observed in the short-term 1-h test, which minimized the contribution of post-ingestion and learned effects. DSF analysis revealed no binding of any of the tested organic acids to the LBD of medaka Tas1r2a/Tas1r3.<br> Conclusions: Organic acids may elicit TAS1R3-dependent post-ingestion signals that contribute to enantiomer-selective consumption in mice. Electrostatic interactions and hydrogen-bonding networks within the orthosteric pocket of TAS1Rs may account for the differences in binding affinity to the LBD of medaka Tas1r2a/Tas1r3 between organic acids and L-alanine, a known ligand. No potential conflict of interest relevant to this article was reported.

The Japan Institute of Heterocyclic Chemistry Acta Medica Okayama 0385-5414 69 1 2006 Synthesis of Functionalized Phospholane Oxides and Phosphorinane Oxides from 1,4- and 1,5-Di-O-Mesyloxy Compounds 283 294 EN Tadashi Hanaya Department of Chemistry, Faculty of Science, Okayama University Karsten Schürrle Department of Chemistry, Faculty of Science, Okayama University Hiroshi Yamamoto Department of Chemistry, Faculty of Science, Okayama University Treatment of 1,4-di-O-mesyl-2,3-di-O-methyl-L-threitol (8b) with phenylphosphine in the presence of sodium hydride in DMSO, followed by the action of hydrogen peroxide, afforded 3,4-dimethoxy-1-phenylphospholane 1- oxide (7), while the same treatment of 1,5-di-O-mesyl-2,3,4-tri-O-methyl-meso- xylitol (11b) provided 2,3,4-trimethoxy-1-phenylphosphorinane 1-oxide (14). No potential conflict of interest relevant to this article was reported.

Elsevier BV Acta Medica Okayama 0009-2541 695 2025 Flash vaporization and migration of iodine in the oceanic plate subduction zone 123031 EN Noriyuki Suzuki Department of Earth and Planetary Sciences, Faculty of Science, Hokkaido University Jun Kameda Institute for Planetary Materials, Okayama University Miki Amo Geology and Geophysics Division, Technology Department, Japan Organization for Metals and Energy Security Crustal fluids in subduction zones, such as subsurface aquifers, submarine seeps, and gas hydrate waters, are often rich in iodine (I2) and methane (CH4). Large-scale aquifers in the Kanto subduction zone, where the Pacific Plate (PAC) and the Philippine Sea Plate (PHS) are subducting, also exhibit high concentrations of I2 and CH4. However, the origin and behavior of I2 in the subduction zone are unclear, and its coexistence with CH4 remains unresolved. To investigate this, we compiled the I2 phase diagram under high-pressure and high-temperature (P–T) conditions to predict its physicochemical properties in the subduction zone. We then applied the P–T paths of subducted PAC and PHS sediments to the I2 phase diagram. Our findings reveal that I2 can exist as a liquid in the young and hot PHS subduction zone. Transient decompressions during earthquake ruptures can cause liquid iodine to flash-vaporize and be expelled from subducted sediments. Along with I2, thermogenic CH4 and hydrogen (H2) generated in the subducted sediments are also released and transported upward, likely by slab-dehydrated fluids. Additionally, H2 may enhance microbial CH4 production through hydrogenotrophic methanogenesis. In subduction zones of young and hot oceanic plates such as the PHS, crustal fluids are enriched in I2 and coexist with CH4 owing to the simultaneous expulsion of I2, CH4, and H2 from the same subducted sediments and their migration via deep fluids. Large subsurface aquifers can act as traps and reservoirs for migrating I2 and CH4, forming large-scale I2 and CH4 deposits. No potential conflict of interest relevant to this article was reported.

AIP Publishing Acta Medica Okayama 0021-9606 163 22 2025 Fourier-transform infrared spectroscopy of hydrogen fluoride dimers in solid parahydrogen 224312 EN Yuki Miyamoto Research Institute for Interdisciplinary Science, Okayama University Hiroki Ooe Graduate School of Natural Science and Technology, Okayama University Susumu Kuma Department of Physics, Rikkyo University We investigate the Fourier-transform infrared spectra of hydrogen fluoride dimers in solid parahydrogen, the detailed analysis of which has remained unexplored. We propose a plausible analysis based on concentration dependence, light polarization, annealing, and time evolution. The absorption lines exhibited multiple peaks, with intensity ratios significantly altered by annealing and by time evolution at a constant temperature. The spectral patterns and isotopic effects suggest that the dimers do not rotate freely in solid parahydrogen, while multiple peaks arise from different stable structures, including single and double substitution sites. Unlike in the gas phase and helium droplets, no tunneling splitting was observed. The broad ν1 band suggests that some dimer structures may exhibit axial rotation. Spectral changes due to annealing likely result from site conversion, while observed IR-induced changes indicate preferential dissociation of dimers in double substitution sites. These findings still remain tentative, necessitating further experimental and theoretical studies. No potential conflict of interest relevant to this article was reported.

Wiley Acta Medica Okayama 0031-9317 177 4 2025 Comparative Transcriptome Reveals ART1-Dependent Regulatory Pathways for Fe Toxicity Response in Rice Roots e70398 EN Yoshiaki Ueda Crop, Livestock and Environment Division, Japan International Research Center for Agricultural Sciences Naoki Yamaji Institute of Plant Science and Resources, Okayama University Matthias Wissuwa Crop, Livestock and Environment Division, Japan International Research Center for Agricultural Sciences Iron (Fe) is an essential element for plants, but an excess supply can have detrimental effects. Fe toxicity induces complex physiological and genetic responses, and due to this complexity, the knowledge of transcriptional regulatory mechanisms under Fe toxicity is very limited. Previous studies suggested that plant responses to excess Fe involve oxidative stress caused by reactive oxygen species (ROS), which itself causes transcriptional changes. We hypothesized that dissecting these complex responses could lead to the identification of a novel factor and conducted a comparative transcriptome analysis using roots of rice plants exposed to nutrient solutions containing 1 or 5 mM of hydrogen peroxide (a major form of ROS) or 300 mg L−1 of Fe (as FeSO4). Genes induced by hydrogen peroxide overlapped with 62%, 49%, and 30% of Fe toxicity-upregulated genes at 3 h, 1 day, and 3 days following treatment initiation. Subsequent gene co-expression analyses classified genes into 21 groups with varying responsiveness to ROS and Fe toxicity. Genes in group 15 were specifically upregulated by Fe toxicity and overlapped significantly with aluminum (Al)-inducible genes and target genes of the Zn-finger transcription factor, ART1, which regulates Al response in rice roots. Additional experiments using the art1 knock-out mutant demonstrated that ART1 is crucial for upregulating genes such as STAR2 and FRDL4 in response to Fe toxicity. This study reveals the contribution of ART1-dependent regulatory pathways in rice roots under Fe toxicity. No potential conflict of interest relevant to this article was reported.

Springer Science and Business Media LLC Acta Medica Okayama 2041-1723 16 1 2025 Efficient and stable n-type sulfide overall water splitting with separated hydrogen production 8786 EN Haolin Luo Research Center for Combustion and Environment Technology, Shanghai Jiao Tong University Zhixi Liu Research Center for Combustion and Environment Technology, Shanghai Jiao Tong University Haifeng Lv State Key Laboratory of Precision and Intelligent Chemistry, School of Chemistry and Material Sciences, and Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), University of Science and Technology of China Junie Jhon M. Vequizo Institute of Aqua Regeneration, Shinshu University Mengting Zheng College of Chemical and Biological Engineering, Zhejiang University Feng Han Research Center for Combustion and Environment Technology, Shanghai Jiao Tong University Zhen Ye Research Center for Combustion and Environment Technology, Shanghai Jiao Tong University Akira Yamakata Faculty of Natural Science and Technology, Okayama University Wenfeng Shangguan Research Center for Combustion and Environment Technology, Shanghai Jiao Tong University Adam F. Lee Centre for Catalysis and Clean Energy, School of Environment and Science, Griffith University Xiaojun Wu State Key Laboratory of Precision and Intelligent Chemistry, School of Chemistry and Material Sciences, and Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), University of Science and Technology of China Domen Kazunari Institute of Aqua Regeneration, Shinshu University Jun Lu College of Chemical and Biological Engineering, Zhejiang University Zhi Jiang Research Center for Combustion and Environment Technology, Shanghai Jiao Tong University N-type sulfide semiconductors are promising photocatalysts due to their broad visible-light absorption, facile synthesis and chemical diversity. However, photocorrosion and limited electron transport in one-step excitation and solid-state Z-scheme systems hinder efficient overall water splitting. Liquid-phase Z-schemes offer a viable alternative, but sluggish mediator kinetics and interfacial side reactions impede their construction. Here we report a stable Z-scheme system integrating n-type CdS and BiVO₄ with a [Fe(CN)₆]³⁻/[Fe(CN)₆]⁴⁻ mediator, achieving 10.2% apparent quantum yield at 450 nm with stoichiometric H₂/O₂ evolution. High activity reflects synergies between Pt@CrOx and Co3O4 cocatalysts on CdS, and cobalt-directed facet asymmetry in BiVO₄, resulting in matched kinetics for hydrogen and oxygen evolution in a reversible mediator solution. Stability is dramatically improved through coating CdS and BiVO4 with different oxides to inhibit Fe4[Fe(CN)6]3 precipitation and deactivation by a hitherto unrecognized mechanism. Separate hydrogen and oxygen production is also demonstrated in a two-compartment reactor under visible light and ambient conditions. This work unlocks the long-sought potential of n-type sulfides for efficient, durable and safe solar-driven hydrogen production. No potential conflict of interest relevant to this article was reported.

MDPI AG Acta Medica Okayama 2073-4344 14 10 2024 Photocatalytic Ammonia Decomposition Using Dye-Encapsulated Single-Walled Carbon Nanotubes 715 EN Tomoyuki Tajima Graduate School of Environmental and Life Science, Okayama University Kotone Yano Graduate School of Environmental and Life Science, Okayama University Kazushi Mukai Department of Materials Design and Engineering, University of Toyama Yutaka Takaguchi Department of Materials Design and Engineering, University of Toyama The photocatalytic decomposition of ammonia to produce N2 and H2 was achieved using single-walled carbon nanotube (SWCNT) nanohybrids. The physical modification of ferrocene-dye-encapsulated CNTs by amphiphilic C60-dendron yielded nanohybrids with a dye/CNT/C60 coaxial heterojunction. Upon irradiation with visible light, an aqueous solution of NH3 and dye@CNT/C60-dendron nanohybrids produced both N2 and H2 in a stoichiometric ratio of 1/3. The action spectra of this reaction clearly demonstrated that the encapsulated dye acted as the photosensitizer, exhibiting an apparent quantum yield (AQY) of 0.22% at 510 nm (the λmax of the dye). This study reports the first example of dye-sensitized ammonia decomposition and provides a new avenue for developing efficient and sustainable photocatalytic hydrogen production systems. No potential conflict of interest relevant to this article was reported.

Elsevier BV Acta Medica Okayama 0006-291X 786 2025 Hydrogen-rich gas enhances mitochondrial membrane potential and respiratory function recovery in Caco-2 cells post-ischemia-reperfusion injury 152753 EN Mizuki Seya Department of Emergency, Critical Care and Disaster Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Toshiyuki Aokage Biological Process of Aging, Tokyo Metropolitan Institute for Geriatrics and Gerontology Ying Meng Department of Emergency, Critical Care and Disaster Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Takahiro Hirayama Department of Emergency, Critical Care and Disaster Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Takafumi Obara Department of Emergency, Critical Care and Disaster Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Tsuyoshi Nojima Department of Emergency, Critical Care and Disaster Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Kosaki Yoshinori Department of Emergency, Critical Care and Disaster Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Tetsuya Yumoto Department of Emergency, Critical Care and Disaster Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Akihiro Watanabe Department of Emergency, Disaster and Critical Care Medicine, Hyogo Medical University Taihei Yamada Department of Emergency, Disaster and Critical Care Medicine, Hyogo Medical University Hiromichi Naito Department of Emergency, Critical Care and Disaster Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Atsunori Nakao Department of Emergency, Critical Care and Disaster Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Background: Ischemia-reperfusion (I/R) injury induces oxidative stress, leading to damage in highly susceptible intestinal tissues. Molecular hydrogen (H2) has shown therapeutic potential in I/R injuries, with our prior research showing its efficacy in improving outcomes in rat intestinal transplantation models. However, its impact on mitochondrial function remain insufficiently understood. This study aims to elucidate how H2 modulates mitochondrial function impaired by I/R injury.<br> Methods: To assess the effects of H2 on I/R injury, cells were divided into three groups: a control group, a hypoxic group (99 % N2, 1 % O2, without H2 for 3, 6, or 24 h), and a hypoxic-H2 group (99 % H2, 1 % O2, for the same durations). After treatment, cells were reoxygenated under normoxic conditions (21 % O2) for 1, 2, 4, or 6 h. Mitochondrial membrane potential, oxygen consumption, and ATP production were measured. Reactive oxygen species production and apoptotic and metabolic regulators were also assessed.<br> Results: H2 markedly promoting mitochondrial recovery following I/R injury, by enhancing ATP production, restoring mitochondrial membrane potential, and improving oxygen consumption. It also reduced ROS levels and suppressed pro-apoptotic signaling. Notably, H2 suppressed the expression of HIF1α and PDK1, suggesting that H2 may act upstream of hypoxia-driven signaling pathways. These changes promoted oxidative phosphorylation and overall cellular function during reperfusion.<br> Conclusions: Our findings reveal that H2 therapy supports mitochondrial function, suppresses ROS, and modulates hypoxia-driven pathways in I/R injury. These insights advance the understanding of H2's potential in addressing I/R injury and provide a foundation for its application in other hypoxia-related conditions. No potential conflict of interest relevant to this article was reported.

Royal Society of Chemistry (RSC) Acta Medica Okayama 2398-4902 2025 Activation of barium titanate for photocatalytic overall water splitting via low-valence cation codoping EN Shigeru Ikeda Faculty of Science and Engineering, Konan University Kaori Takagi Faculty of Science and Engineering, Konan University Ryota Tomizawa Carbon Neutral Energy Development Division, Toyota Motor Corporation Tomoya Nagano Carbon Neutral Energy Development Division, Toyota Motor Corporation Koji Hayashi Carbon Neutral Energy Development Division, Toyota Motor Corporation Akira Yamakata Research Institute for Interdisciplinary Science, Okayama University Yoshitaro Nose Department of Materials Science and Engineering, Kyoto University Barium titanate (BaTiO3) has long been regarded as inactive for photocatalytic overall water splitting, in stark contrast to its perovskite counterparts SrTiO3 and CaTiO3. Here we report that BaTiO3 codoped with Al3+ and Sc3+ at Ti4+ sites under flux synthesis conditions is activated as a robust photocatalyst for overall water splitting. This material achieves apparent quantum yields of 29.8% at 310 nm and 27.5% at 365 nm, representing the first demonstration of efficient overall water splitting on BaTiO3. Comparative analyses show that BaTiO3 doped only with Al3+ suffers from severe band-edge disorder, whereas BaTiO3 codoped with Al3+ and Mg2+ exhibits clear activation with moderate efficiency. In contrast, BaTiO3 codoped with Al3+ and Sc3+ achieves the critical defect and structural control required to push the material across the threshold from inactive to highly active. These findings overturn the long-standing perception of BaTiO3 as unsuitable for water splitting and establish a general design principle for activating previously inactive perovskite oxides, thereby expanding the materials palette for solar-to-hydrogen energy conversion. No potential conflict of interest relevant to this article was reported.

Elsevier BV Acta Medica Okayama 0008-6223 243 2025 Organic solvent transport through reduced graphene oxide membranes with controlled oxygen content 120539 EN Hongzhe Chen School of Materials Science and Engineering, University of New South Wales Sydney Tongxi Lin School of Materials Science and Engineering, University of New South Wales Sydney Zeno Rizqi Ramadhan Electron Microscope Unit, University of New South Wales Aditya Rawal Mark Wainwright Analytical Centre, University of New South Wales Yuta Nishina Research Institute for Interdisciplinary Science, Okayama University Amir Karton School of Science and Technology, University of New England Xiaojun Ren School of Materials Science and Engineering, University of New South Wales Sydney Rakesh Joshi School of Materials Science and Engineering, University of New South Wales Sydney Recent advances in membranes based on 2-dimensional (2D) materials have enabled precise control over angstrom-scale pores, providing a unique platform for studying diverse mass transport mechanisms. In this work, we systematically investigate the transport of solvent vapors through 2D channels made of graphene oxide (GO) laminates with precisely controlled oxygen content. Using in-situ chemical reduction of GO with vitamin C, we fabricated reduced GO membranes (VRGMs) with oxygen content systematically decreased from 31.6 % (pristine GO) to 24.0 % (VRGM-maximum reduction). Vapor permeability measurements showed a distinct correlation between oxygen functional groups and solvent transport behaviour. Specifically, non-polar hexane exhibits 114 % of enhanced permeance through the reduced membranes with larger graphitic domains, while the permeance of water decreases by 55 %. With the support of density functional theory (DFT) simulations, we modelled the hydrogen-bond and dispersion complexes between the solvents and GO and calculated the complexation energies. The simulation results suggest that polar molecules interact with the oxygen functional groups of GO via a hydrogen-bond network, supporting in-plane transport. In contrast, van der Waals forces drive the transport of low-polarity solvents along the graphitic domains of the 2D channel in reduced GO membranes. Our findings provide potential strategies for future design of organic solvent nanofiltration membranes. No potential conflict of interest relevant to this article was reported.

Springer Science and Business Media LLC Acta Medica Okayama 1939-5981 2025 MATERIAL PROPERTIES OF DIE-CASTING DIE AROUND HEAT-CHECKING CREATED BY A HIGH-PRESSURE ALUMINUM ALLOY DIE-CASTING OPERATION EN Mitsuhiro Okayasu Department of Mechanical Systems Engineering, Okayama University Junya Shimazu Department of Mechanical Systems Engineering, Okayama University In this study, the material properties of a nitride die-casting die exhibiting heat-checking after the die-casting process were experimentally investigated using various methods. Based on the obtained results, the authors believe that several possible mechanisms underlying the formation of heat-checking can be identified. The microstructure of the die-casting die near the heat-checking region is characterized by equiaxed grains along the vicinity of the prior γ-grain boundaries, resulting from the lath martensitic formation. Additionally, numerous Cr–Mo–V-based nitride particles, approximately 100 nm in diameter, are precipitated. The surface hardness of the die-casting die, enhanced by nitriding, induces compressive residual stresses and increases adhesive forces. As a result of changes in microstructural characteristics and crack formation, the stress state near the die-casting die is altered, where compressive residual stresses, observed in the die-casting die, are released, leading to the tensile residual stresses. This phenomenon could accelerate the formation of a large number of heat-checking cracks. No potential conflict of interest relevant to this article was reported.

Elsevier BV Acta Medica Okayama 0360-3199 140 2025 Advances in filler-crosslinked membranes for hydrogen fuel cells in sustainable energy generation 745 776 EN Aminul Islam Department of Petroleum and Mining Engineering, Jashore University of Science and Technology Mamun Shahriar Department of Petroleum and Mining Engineering, Jashore University of Science and Technology Md. Tarekul Islam Department of Leather Engineering, Faculty of Mechanical Engineering, Khulna University of Engineering and Technology Siow Hwa Teo Industrial Chemistry Program, Faculty of Science and Natural Resources, Universiti Malaysia Sabah M. Azizur R. Khan Department of Chemistry, Jashore University of Science and Technology Yun Hin Taufiq-Yap Catalysis Science and Technology Research Centre, Faculty of Science, Universiti Putra Malaysia Suman C. Mohanta Department of Chemistry, Jashore University of Science and Technology Ariyan Islam Rehan Department of Chemistry, School of Science, The University of Tokyo Adiba Islam Rasee Department of Chemistry, Graduate School of Science, Osaka University Khadiza Tul Kubra Department of Chemistry, Graduate School of Science, Osaka University Md. Munjur Hasan Department of Chemistry, Graduate School of Science, Osaka University Md. Shad Salman Institute for Chemical Research, Kyoto University R.M. Waliullah Institute for Chemical Research, Kyoto University Md. Nazmul Hasan Department of Chemistry, School of Science, The University of Tokyo Md. Chanmiya Sheikh Division of Applied Chemistry, Graduate School of Natural Science and Technology, Okayama University Tetsuya Uchida Division of Applied Chemistry, Graduate School of Natural Science and Technology, Okayama University Mrs Eti Awual Institute for Chemical Research, Kyoto University Mohammed Sohrab Hossain Department of Chemistry, Graduate School of Science, Osaka University Hussein Znad Western Australian School of Mines: Minerals, Energy and Chemical Engineering, Curtin University Md. Rabiul Awual Western Australian School of Mines: Minerals, Energy and Chemical Engineering, Curtin University Fuel cell membranes can be used in various ways to achieve zero-emission transport and energy systems, which offer a promising way to power production due to their higher efficiency compared to the internal combustion engine and the eco-environment. Perfluoro sulfonic acid membranes used for proton exchange membranes (PEMs) have certain drawbacks, like higher fuel permeability and expense, lower mechanical and chemical durability, and proton conductivity under low humidity and above 80 °C temperature. Researchers have drawn their attention to the production of polymer electrolyte membranes with higher proton conductivity, thermal and chemical resilience, maximum power density, lower fuel permeability, and lower expense. For sustainable clean energy generation, a review covering the most useful features of advanced material-associated membranes would be of great benefit to all interested communities. This paper endeavors to explore several types of novel inorganic fillers and crosslinking agents, which have been incorporated into membrane matrices to design the desired properties for an advanced fuel cell system. Membrane parameters such as proton conductivity, the ability of H2 transport, and the stability of the membrane are described. Research directions for developing fuel cell membranes are addressed based on several challenges suggested. The technological advancement of nanostructured materials for fuel cell applications is believed to significantly promote the future clean energy generation technology in practice. No potential conflict of interest relevant to this article was reported.

Elsevier BV Acta Medica Okayama 0360-3199 101 2025 Next frontier in photocatalytic hydrogen production through CdS heterojunctions 173 211 EN Aminul Islam Department of Petroleum and Mining Engineering, Jashore University of Science and Technology Abdul Malek Department of Petroleum and Mining Engineering, Jashore University of Science and Technology Md. Tarekul Islam Department of Leather Engineering, Faculty of Mechanical Engineering, Khulna University of Engineering and Technology Farzana Yeasmin Nipa Department of Petroleum and Mining Engineering, Jashore University of Science and Technology Obayed Raihan Department of Pharmaceutical Sciences, College of Health Sciences and Pharmacy, Chicago State University Hasan Mahmud Bangladesh Energy and Power Research Council (BEPRC) Md. Elias Uddin Department of Leather Engineering, Faculty of Mechanical Engineering, Khulna University of Engineering and Technology Mohd Lokman Ibrahim School of Chemistry and Environment, Faculty of Applied Sciences, Universiti Teknologi MARA G. Abdulkareem-Alsultan Catalysis Science and Technology Research Centre, Faculty of Science, Universiti Putra Malaysia Alam Hossain Mondal USAID - Bangladesh Advancing Development and Growth through Energy (BADGE) Project, Tetra Tech Md. Munjur Hasan Department of Chemistry, Graduate School of Science, Osaka University Md. Shad Salman Institute for Chemical Research, Kyoto University Khadiza Tul Kubra Department of Chemistry, Graduate School of Science, Osaka University Md. Nazmul Hasan Department of Chemistry, School of Science, The University of Tokyo Md. Chanmiya Sheikh Division of Applied Chemistry, Graduate School of Natural Science and Technology, Okayama University Tetsuya Uchida Division of Applied Chemistry, Graduate School of Natural Science and Technology, Okayama University Adiba Islam Rasee Department of Chemistry, Graduate School of Science, Osaka University Ariyan Islam Rehan Department of Chemistry, School of Science, The University of Tokyo Mrs Eti Awual Institute for Chemical Research, Kyoto University Mohammed Sohrab Hossain Department of Chemistry, Graduate School of Science, Osaka University R.M. Waliullah Institute for Chemical Research, Kyoto University Md. Rabiul Awual Western Australian School of Mines: Minerals, Energy and Chemical Engineering, Curtin University Photocatalytic hydrogen (H₂) generation via solar-powered water splitting represents a sustainable solution to the global energy crisis. Cadmium sulfide (CdS) has emerged as a promising semiconductor photocatalyst due to its tunable bandgap, high physicochemical stability, cost-effectiveness, and widespread availability. This review systematically examines recent advancements in CdS-based heterojunctions, categorized into CdS-metal (Schottky), CdS-semiconductor (p-n, Z-scheme, S-scheme), and CdS-carbon heterojunctions. Various strategies employed to enhance photocatalytic efficiency and stability are discussed, including band structure engineering, surface modification, and the incorporation of crosslinked architectures. A critical evaluation of the underlying photocatalytic mechanisms highlights recent efforts to improve charge separation and photostability under operational conditions. This review highlights the challenges and opportunities in advancing CdS-based photocatalysts and provides a direction for future research. The insights presented aim to accelerate the development of efficient and durable CdS-based photocatalysts for sustainable H₂ production. No potential conflict of interest relevant to this article was reported.

Elsevier BV Acta Medica Okayama 0001-8686 343 2025 Progress in silicon-based materials for emerging solar-powered green hydrogen (H2) production 103558 EN Aminul Islam Department of Petroleum and Mining Engineering, Jashore University of Science and Technology Md. Tarekul Islam Department of Leather Engineering, Faculty of Mechanical Engineering, Khulna University of Engineering and Technology Siow Hwa Teo Industrial Chemistry Program, Faculty of Science and Natural Resources, Universiti Malaysia Sabah Hasan Mahmud Bangladesh Energy and Power Research Council (BEPRC) A.M. Swaraz Department of Genetic Engineering and Biotechnology, Jashore University of Science and Technology Ariyan Islam Rehan Department of Chemistry, School of Science, The University of Tokyo Adiba Islam Rasee Department of Chemistry, Graduate School of Science, Osaka University Khadiza Tul Kubra Department of Chemistry, Graduate School of Science, Osaka University Md. Munjur Hasan Department of Chemistry, Graduate School of Science, Osaka University Md. Shad Salman Institute for Chemical Research, Kyoto University R.M. Waliullah Institute for Chemical Research, Kyoto University Md. Nazmul Hasan Department of Chemistry, School of Science, The University of Tokyo Md. Chanmiya Sheikh Division of Applied Chemistry, Graduate School of Natural Science and Technology, Okayama University Tetsuya Uchida Division of Applied Chemistry, Graduate School of Natural Science and Technology, Okayama University Mrs Eti Awual Department of Chemistry, Graduate School of Science, Osaka University Mohammed Sohrab Hossain Department of Chemistry, Graduate School of Science, Osaka University Hussein Znad Western Australian School of Mines: Minerals, Energy and Chemical Engineering, Curtin University Md. Rabiul Awual Western Australian School of Mines: Minerals, Energy and Chemical Engineering, Curtin University The imperative demand for sustainable and renewable energy solutions has precipitated profound scientific investigations into photocatalysts designed for the processes of water splitting and hydrogen fuel generation. The abundance, low toxicity, high conductivity, and cost-effectiveness of silicon-based compounds make them attractive candidates for hydrogen production, driving ongoing research and technological advancements. Developing an effective synthesis method that is simple, economically feasible, and environmentally friendly is crucial for the widespread implementation of silicon-based heterojunctions for sustainable hydrogen production. Balancing the performance benefits with the economic and environmental considerations is a key challenge in the development of these systems. The specific performance of each catalyst type can vary depending on the synthesis method, surface modifications, catalyst loading, and reaction conditions. The confluence of high crystallinity, reduced oxygen concentration, and calcination temperature within the silicon nanoparticle has significantly contributed to its noteworthy hydrogen evolution rate. This review provides an up-to-date evaluation of Si-based photocatalysts, summarizing recent developments, guiding future research directions, and identifying areas that require further investigation. By combining theoretical insights and experimental findings, this review offers a comprehensive understanding of Si-based photocatalysts for water splitting. Through a comprehensive analysis, it aims to elucidate existing knowledge gaps and inspire future research directions towards optimized photocatalytic performance and scalability, ultimately contributing to the realization of sustainable hydrogen generation. No potential conflict of interest relevant to this article was reported.

Springer Science and Business Media LLC Acta Medica Okayama 1598-2351 2025 Hydrogen Embrittlement Characteristics of Austenitic Stainless Steels After Punching Process EN Mitsuhiro Okayasu Department of Mechanical and Systems Engineering, Okayama University Xichang Li Department of Mechanical and Systems Engineering, Okayama University Tomohisa Kawakami SHOYO SANGYO Co., Ltd. This study investigates the influence of microstructural characteristics on the hydrogen embrittlement of SUS304 austenitic stainless steel. The investigation utilized SUS304 sheets with a thickness of 1.5 mm, which were processed by punching with an 8 mm diameter to make specimens. Severe plastic deformation was localized near the punching edge, with the extent of deformation determined by the punching speed. Slower punching speeds induced more pronounced plastic strain, which was closely associated with work hardening and strain-induced martensitic (SIM) transformation. The SIM phase was predominantly observed within a depth of approximately 0.1 mm from the punched edge when processed at a punching speed of 0.25 mm/s, corresponding to roughly 10% of the cross-sectional area of the sample. These microstructural changes led to a significant reduction in tensile and fatigue strength, thereby exacerbating susceptibility to severe hydrogen embrittlement, despite the limited extent of microstructural alteration. Based on these findings, a modified Goodman diagram for SUS304 austenitic stainless steel, incorporating mechanical properties and hydrogen embrittlement behavior, was proposed. No potential conflict of interest relevant to this article was reported.

Proceedings of the National Academy of Sciences Acta Medica Okayama 0027-8424 122 32 2025 Structural insights into a citrate transporter that mediates aluminum tolerance in barley e2501933122 EN Tran Nguyen Thao Degree Program in Interdisciplinary Sciences, Graduate School of Environmental, Life, Natural Science, and Technology, Okayama University Namiki Mitani-Ueno Research Core for Plant Stress Science, Institute of Plant Science and Resources, Okayama University Ryo Urano Division of Superconducting and Functional Materials, Research Institute for Interdisciplinary Science, Okayama University Yasunori Saitoh Degree Program in Interdisciplinary Sciences, Graduate School of Environmental, Life, Natural Science, and Technology, Okayama University Peitong Wang Research Core for Plant Stress Science, Institute of Plant Science and Resources, Okayama University Naoki Yamaji Research Core for Plant Stress Science, Institute of Plant Science and Resources, Okayama University Jian-Ren Shen Degree Program in Interdisciplinary Sciences, Graduate School of Environmental, Life, Natural Science, and Technology, Okayama University Wataru Shinoda Degree Program in Interdisciplinary Sciences, Graduate School of Environmental, Life, Natural Science, and Technology, Okayama University Jian Feng Ma Research Core for Plant Stress Science, Institute of Plant Science and Resources, Okayama University Michihiro Suga Degree Program in Interdisciplinary Sciences, Graduate School of Environmental, Life, Natural Science, and Technology, Okayama University HvAACT1 is a major aluminum (Al)-tolerance gene in barley, encoding a citrate transporter that belongs to the multidrug and toxic compound extrusion (MATE) family. This transporter facilitates citrate secretion from the roots, thereby detoxifying external Al ions―a major constraint of crop production on acidic soils. In this study, we present the outward-facing crystal structure of HvAACT1, providing insights into a citrate transport mechanism. The putative citrate binding site consists of three basic residues―K126 in transmembrane helix 2 (TM2), R358 in TM7, and R535 in TM12―creating substantial positive charges in the C-lobe cavity. Proton coupling for substrate transport may involve two pairs of aspartate residues in the N-lobe cavity, one of which corresponds to the essential Asp pair found in prokaryotic H+-coupled MATE transporters belonging to the DinF subfamily. Structural coupling between proton uptake in the N-lobe and citrate extrusion in the C-lobe can be enabled by an extensive, unique hydrogen-bonding network at the extracellular half of the N-lobe. Mutation-based functional analysis, structural comparisons, molecular dynamics simulation, and phylogenic analysis suggest an evolutionary link between citrate MATE transporters and the DinF MATE subfamily. Our findings provide a solid structural basis for citrate transport by HvAACT1 in barley and contribute to a broader understanding of citrate transporter structures in other plant species. No potential conflict of interest relevant to this article was reported.

American Chemical Society (ACS) Acta Medica Okayama 2691-3704 2025 Electrochemical Generation of Sulfonamidyl Radicals via Anodic Oxidation of Hydrogen Bonding Complexes: Applications to Electrosynthesis of Benzosultams EN Yasuyuki Okumura Division of Applied Chemistry, Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Eisuke Sato Division of Applied Chemistry, Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Koichi Mitsudo Division of Applied Chemistry, Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Seiji Suga Division of Applied Chemistry, Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Amidyl radicals and sulfonamidyl radicals are widely used in the field of organic synthesis. In particular, the electrochemical oxidation of amides in the presence of bases is one of the most practical methods for generating amidyl radicals. However, it is often difficult to observe the “true” radical precursor, such as an amide anion and/or a hydrogen bonding complex with an amide and a base. We found that a sulfonamide and Bu4NOAc form a 1:1 hydrogen bonding complex by spectroscopic experiments. Cyclic voltammetry suggested that 1:1 hydrogen bonding complexes should be oxidized predominantly under the optimized conditions to afford a sulfonamidyl radical via the proton-coupled electron transfer (PCET) process by the oxidation of the complex. Thus-generated sulfonamidyl radicals could be used in the electrochemical synthesis of a variety of benzosultams. No potential conflict of interest relevant to this article was reported.

Wiley Acta Medica Okayama 0031-9317 177 4 2025 CNGC2 Negatively Regulates Stomatal Closure and Is Not Required for flg22- and H2O2-Induced Guard Cell [Ca2+]cyt Elevation in Arabidopsis thaliana e70396 EN Rojina Akter Graduate School of Environmental and Life Science, Okayama University Yasuhiro Inoue Graduate School of Environmental and Life Science, Okayama University Saori Masumoto Faculty of Agriculture, Okayama University Yoshiharu Mimata Graduate School of Environmental and Life Science, Okayama University Takakazu Matsuura Institute of Plant Science and Resources, Okayama University Izumi C. Mori Toshiyuki Nakamura Graduate School of Environmental and Life Science, Okayama University Yoshimasa Nakamura Graduate School of Environmental and Life Science, Okayama University Yoshiyuki Murata Graduate School of Environmental and Life Science, Okayama University Shintaro Munemasa Graduate School of Environmental and Life Science, Okayama University In guard cells, cytosolic Ca2+ acts as a second messenger that mediates abscisic acid (ABA)- and pathogen-associated molecular pattern (PAMP)-induced stomatal closure. It was reported that Arabidopsis cyclic nucleotide-gated ion channel 2 (CNGC2) functions as hydrogen peroxide (H2O2)- and PAMP-activated Ca2+-permeable channels at the plasma membrane of mesophyll cells and mediates Ca2+-dependent PAMP-triggered immunity. In this study, we examined the role of CNGC2 in the regulation of stomatal movement because CNGC2 is also expressed in guard cells. We found that stomata of the CNGC2 disruption mutant cngc2-3 are constitutively closed even in the absence of ABA or the flagellar-derived PAMP, flg22. Consistently, leaf temperatures of the cngc2-3 mutant were higher than those of wild-type (WT) plants. The stomatal phenotype of the cngc2-3 mutant was restored by complementation with wild-type CNGC2 under the control of the guard cell preferential promoter, pGC1. Elevation of cytosolic free Ca2+ concentration in guard cells induced by flg22 and H2O2 remained intact in the cngc2-3 mutant. The introduction of the ost1-3 mutation into the cngc2-3 background did not alter the stomatal phenotype. However, the stomatal phenotype of the cngc2-3 mutant was successfully rescued in the double disruption mutant cngc2-3aba2-2. Taken together, these results suggest that CNGC2 negatively regulates stomatal closure response and does not function as flg22– and H2O2-activated Ca2+ channels in guard cells. Though CNGC2 is responsive for H2O2- and flg22-induced [Ca2+]cyt elevation in mesophyll cells, the involvement of CNGC2 in the response to H2O2 and flg22 in guard cells is questionable. No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 2025 Roles of GUARD CELL HYDROGEN PEROXIDE-RESISTANT1 and endogenous abscisic acid in guard-cell signaling EN SHAIEK Oumayma Graduate School of Environmental and Life Science, Okayama University No potential conflict of interest relevant to this article was reported.

American Chemical Society (ACS) Acta Medica Okayama 1523-7060 27 18 2025 Electrochemical Oxidation of Benzyl Alcohols via Hydrogen Atom Transfer Mediated by 2,2,2-Trifluoroethanol 4737 4741 EN Takahiro Kawajiri API R&D Laboratory, Research Division, Shionogi & Co., Ltd. Masahiro Hosoya API R&D Laboratory, Research Division, Shionogi & Co., Ltd. Satoshi Goda API R&D Laboratory, Research Division, Shionogi & Co., Ltd. Eisuke Sato Division of Applied Chemistry, Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Seiji Suga Division of Applied Chemistry, Graduate School of Environmental, Life, Natural Science and Technology, Okayama University We report a novel electrochemical oxidation of benzyl alcohols. We found that trifluoroethanol plays a role as a hydrogen atom transfer (HAT) mediator, enabling the oxidation of electron-deficient substrates that are difficult to directly oxidize on electrode surfaces. Density functional theory calculations, cyclic voltammetry measurements, and constant potential electrolysis studies supported the proposed HAT mechanism. Moreover, the obtained carbonyl compounds could be functionalized in an electrochemical one-pot manner, further highlighting their synthetic utility. No potential conflict of interest relevant to this article was reported.

MDPI Acta Medica Okayama 2227-9032 13 5 2025 Efficacy of Oral Intake of Hydrogen-Rich Jelly Intake on Gingival Inflammation: A Double-Blind, Placebo-Controlled and Exploratory Randomized Clinical Trial 577 EN Takayuki Maruyama Department of Preventive Dentistry, Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Eiji Takayama Department of Oral Biochemistry, Asahi University School of Dentistry Shinichi Tokuno Graduate School of Health Innovation, Kanagawa University of Human Services Manabu Morita Department of Oral Health, Takarazuka University of Medical and Health Care Daisuke Ekuni Department of Preventive Dentistry, Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Background/Objectives: Initiation and progression of periodontal disease include oxidative stress. Systemic application of antioxidants may provide clinical benefits against periodontal disease including gingivitis. Recently, a jelly containing a high concentration of hydrogen (40 ppm) was developed. We hypothesized that oral intake of this hydrogen-rich jelly may be safe and effective on gingivitis. This clinical trial was designed to investigate the safety and efficacy of oral intake of hydrogen-rich jelly against gingival inflammation. Methods: Participants with gingivitis were instructed to orally ingest 30 g of hydrogen-rich jelly (experimental group) or placebo jelly (control group) three times a day for 14 consecutive days. The primary outcome of this trial was the percentage of bleeding on probing (BOP) sites. Secondary outcomes were oral parameters, serum reactive oxygen metabolites, antioxidant capacity, oxidative index, concentrations of cytokine (interleukin [IL]-1β, IL-6, IL-10, IL-17, and tumor necrosis factor-alpha) in gingival crevicular fluid, and adverse events. For all parameters, Mann–Whitney U test was used for comparison between experimental and control groups. Analysis of covariance, controlling for baseline periodontal inflamed surface area, was performed to evaluate the association between the effect of the hydrogen-rich jelly and gingival inflammation. Results: In the experiment and control groups, the percentage of sites with BOP and PISA significantly decreased at the end of the experiment compared to the baseline. However, no significant differences were found between groups (p > 0.05). Conclusions: Administration of hydrogen-rich jelly for 14 days decreased gingival inflammation. However, no significant differences were identified compared to the control group. No potential conflict of interest relevant to this article was reported.

Okayama University Medical School Acta Medica Okayama 0386-300X 79 1 2025 Retrospective Analysis of the Safety of High-Volume Dental Articaine Preparations for Japanese Patients 31 37 EN Shigeru Maeda Department of Dental Anesthesiology, Graduate School of Medical and Dental Sciences, Institute of Science Tokyo Atiphan Pimkhaokham Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Chulalongkorn University Michihiro Yoshida Data Science Division, Center for Innovative Clinical Medicine, Okayama University Hospital Hiroki Hosoi Data Science Division, Center for Innovative Clinical Medicine, Okayama University Hospital Ayako Ohshima Data Science Division, Center for Innovative Clinical Medicine, Okayama University Hospital Ryoko Kurisu Department of Dental Anesthesiology, Graduate School of Medical and Dental Sciences, Institute of Science Tokyo Nozomi Utsumi Department of Dental Anesthesiology, Graduate School of Medical and Dental Sciences, Institute of Science Tokyo Hitoshi Higuchi Department of Dental Anesthesiology and Special Care Dentistry, Okayama University Hospital Takuya Miyawaki Department of Dental Anesthesiology and Special Care Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Original Article 10.18926/AMO/68356 We retrospectively analyzed the safety of the use of articaine, an amide-type local anesthetic, in Japanese dental patients (n=300) treated in Thailand in 2015-2017. The dosage, adverse events (AEs) caused by local anesthesia, and treatment efficacy were examined. Articaine, which is safe for patients with liver impairments due to its unique metabolism, has not been thoroughly tested in Japan for doses above 5.1 mL. Eighty of the present patients had undergone root canal treatment (RCT), 71 underwent tooth extraction, and 149 underwent implant-related surgery. More than three articaine cartridges were used in 41 patients, and no AEs occurred in these cases. The only AE occurred in a 52-year-old woman who was treated with three cartridges and presented with what appeared to be hyperventilation syndrome; she later recovered and received her dental treatment as scheduled. Most treatments were completed with three or fewer cartridges, suggesting that this number is generally sufficient. Our findings, particularly the low AE risk even with doses exceeding three cartridges, support the potential applicability of the overseas recommended maximum dose of articaine (7 mg/kg) in Japanese patients. This conclusion is significant for advancing dental anesthetic practices and ensuring patient safety and treatment efficacy in Japan. No potential conflict of interest relevant to this article was reported.

Oxford University Press Acta Medica Okayama 2050-3911 2025 1 2024 Modification on Thermal Motion in Geant4 for Neutron Capture Simulation in Gadolinium Loaded Water 013C01 EN Y. Hino Department of Physics, Okayama University K. Abe Kamioka Observatory, Institute for Cosmic Ray Research, University of Tokyo R. Asaka Department of Physics, Faculty of Science and Technology, Tokyo University of Science S. Han Research Center for Cosmic Neutrinos, Institute for Cosmic Ray Research, University of Tokyo M. Harada Kamioka Observatory, Institute for Cosmic Ray Research, University of Tokyo M. Ishitsuka Department of Physics, Faculty of Science and Technology, Tokyo University of Science H. Ito Department of Physics, Faculty of Science and Technology, Tokyo University of Science S. Izumiyama Department of Physics, Tokyo Institute of Technology Y. Kanemura Kamioka Observatory, Institute for Cosmic Ray Research, University of Tokyo Y. Koshio Department of Physics, Okayama University F. Nakanishi Department of Physics, Okayama University H. Sekiya Kamioka Observatory, Institute for Cosmic Ray Research, University of Tokyo T. Yano Kamioka Observatory, Institute for Cosmic Ray Research, University of Tokyo Neutron tagging is a fundamental technique for electron anti-neutrino detection via the inverse beta decay channel. A reported discrepancy in neutron detection efficiency between observational data and simulation predictions prompted an investigation into neutron capture modeling in Geant4. The study revealed that an overestimation of the thermal motion of hydrogen atoms in Geant4 impacts the fraction of captured nuclei. By manually modifying the Geant4 implementation, the simulation results align with calculations based on evaluated nuclear data and show good agreement with observables derived from the SK-Gd data. No potential conflict of interest relevant to this article was reported.

AIP Publishing Acta Medica Okayama 0021-9606 161 21 2024 The nature of the hydrophobic interaction varies as the solute size increases from methane’s to C60’s 214501 EN Hidefumi Naito Department of Chemistry, Faculty of Science, Okayama University Tomonari Sumi Department of Chemistry, Faculty of Science, Okayama University Kenichiro Koga Department of Chemistry, Faculty of Science, Okayama University The hydrophobic interaction, often combined with the hydrophilic or ionic interactions, makes the behavior of aqueous solutions very rich and plays an important role in biological systems. Theoretical and computer simulation studies have shown that the water-mediated force depends strongly on the size and other chemical properties of the solute, but how it changes with these factors remains unclear. We report here a computer simulation study that illustrates how the hydrophobic pair interaction and the entropic and enthalpic terms change with the solute size when the solute–solvent weak attractive interaction is unchanged with the solute size. The nature of the hydrophobic interaction changes qualitatively as the solute size increases from that of methane to that of fullerene. The potential of mean force between small solutes has several well-defined extrema, including the third minimum, whereas the potential of mean force between large solutes has the deep contact minimum and the large free-energy barrier between the contact and the water-bilayer separated configurations. The difference in the potential of mean force is related to the differences in the water density, energy, and hydrogen bond number distributions in the vicinity of the pairs of hydrophobic solutes. No potential conflict of interest relevant to this article was reported.

Wiley Acta Medica Okayama 0947-6539 30 70 2024 MoSe2-Sensitized Water Splitting Assisted by C60-Dendrons on the Basal Surface e202402690 EN Tomoyuki Tajima Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Tomoki Matsuura Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Arif Efendi Department of Materials Design and Engineering, University of Toyama Mariko Yukimoto Department of Materials Design and Engineering, University of Toyama Yutaka Takaguchi Department of Materials Design and Engineering, University of Toyama To facilitate water splitting using MoSe2 as a light absorber, we fabricated water-dispersible MoSe2/C60-dendron nanohybrids via physical modification of the basal plane of MoSe2. Upon photoirradiation, the mixed-dimension MoSe2/C60 (2D/0D) heterojunction generates a charge-separated state (MoSe2⋅+/C60⋅−) through electron extraction from the exciton in MoSe2 to C60. This process is followed by the hydrogen evolution reaction (HER) from water in the presence of a sacrificial donor (1-benzyl-1,4-dihydronicotinamide) and co-catalyst (Pt-PVP). The apparent quantum yields of the HER were estimated to be 0.06 % and 0.27 % upon photoexcitation at the A- and B-exciton absorption peaks (λmax=800 and 700 nm), respectively. No potential conflict of interest relevant to this article was reported.

MDPI Acta Medica Okayama 2223-7747 13 15 2024 Light-Driven H2 Production in Chlamydomonas reinhardtii: Lessons from Engineering of Photosynthesis 2114 EN Michael Hippler Institute of Plant Science and Resources, Okayama University Fatemeh Khosravitabar Department of Biological and Environmental Sciences, University of Gothenburg In the green alga Chlamydomonas reinhardtii, hydrogen production is catalyzed via the [FeFe]-hydrogenases HydA1 and HydA2. The electrons required for the catalysis are transferred from ferredoxin (FDX) towards the hydrogenases. In the light, ferredoxin receives its electrons from photosystem I (PSI) so that H-2 production becomes a fully light-driven process. HydA1 and HydA2 are highly O-2 sensitive; consequently, the formation of H-2 occurs mainly under anoxic conditions. Yet, photo-H-2 production is tightly coupled to the efficiency of photosynthetic electron transport and linked to the photosynthetic control via the Cyt b(6)f complex, the control of electron transfer at the level of photosystem II (PSII) and the structural remodeling of photosystem I (PSI). These processes also determine the efficiency of linear (LEF) and cyclic electron flow (CEF). The latter is competitive with H-2 photoproduction. Additionally, the CBB cycle competes with H-2 photoproduction. Consequently, an in-depth understanding of light-driven H-2 production via photosynthetic electron transfer and its competition with CO2 fixation is essential for improving photo-H-2 production. At the same time, the smart design of photo-H-2 production schemes and photo-H-2 bioreactors are challenges for efficient up-scaling of light-driven photo-H-2 production. No potential conflict of interest relevant to this article was reported.

Beilstein-Institut Acta Medica Okayama 1860-5397 20 2024 Electrocatalytic hydrogenation of cyanoarenes, nitroarenes, quinolines, and pyridines under mild conditions with a proton-exchange membrane reactor 1560 1571 EN Koichi Mitsudo Division of Applied Chemistry, Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Atsushi Osaki Division of Applied Chemistry, Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Haruka Inoue Division of Applied Chemistry, Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Eisuke Sato Division of Applied Chemistry, Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Naoki Shida Graduate School of Engineering Science and Advanced Chemical Energy Research Center, Yokohama National University Mahito Atobe Graduate School of Engineering Science and Advanced Chemical Energy Research Center, Yokohama National University Seiji Suga Division of Applied Chemistry, Graduate School of Environmental, Life, Natural Science and Technology, Okayama University An electrocatalytic hydrogenation of cyanoarenes, nitroarenes, quinolines, and pyridines using a proton-exchange membrane (PEM) reactor was developed. Cyanoarenes were then reduced to the corresponding benzylamines at room temperature in the presence of ethyl phosphate. The reduction of nitroarenes proceeded at room temperature, and a variety of anilines were obtained. The quinoline reduction was efficiently promoted by adding a catalytic amount of p-toluenesulfonic acid (PTSA) or pyridinium p-toluenesulfonate (PPTS). Pyridine was also reduced to piperidine in the presence of PTSA. No potential conflict of interest relevant to this article was reported.

MDPI Acta Medica Okayama 2227-9032 12 10 2024 Effect of Antimicrobial Photodynamic Therapy on the Tongue Dorsum on Reducing Halitosis and the Duration of the Effect: A Randomized Clinical Trial 980 EN Takayuki Maruyama Department of Preventive Dentistry, Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Daisuke Ekuni Department of Preventive Dentistry, Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Aya Yokoi Department of Preventive Dentistry, Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Junichiro Nagasaki Okayama University Dental School Nanami Sawada Department of Preventive Dentistry, Okayama University Hospital Manabu Morita Department of Oral Health Sciences, Takarazuka University of Medical and Health Care Antimicrobial photodynamic therapy (PDT) is a treatment that is gaining popularity in modern clinical medicine. However, little is known about the effect of PDT alone on reducing oral halitosis and the duration of the effect. This trial examined the effect of PDT on the tongue dorsum on reducing oral halitosis and the duration of the effect. This study was approved by the Ethics Committee of Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, and Okayama University Hospital (CRB20-015), and it was registered in the Japan Registry of Clinical Trials (jRCTs061200060). Twenty-two participants were randomly assigned to two groups: an intervention group and control group. PDT was performed in the intervention group using red laser emission and methylene blue gel on the middle and posterior area of the tongue dorsum. The concentration of volatile sulfur compounds, bacterial count on the tongue dorsum, probing pocket depth, bleeding on probing, and simplified oral debris index score were determined before and 1 week after PDT. The Mann-Whitney U test was used to assess the significance of the differences in each parameter between the two groups. We found that the hydrogen sulfide concentration and bacterial count on the tongue dorsum were decreased in the intervention group, but there was no statistically significant difference between the two groups. These results indicated that performing only PDT on the tongue dorsum may not contribute to reducing halitosis. No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 2024 Hydrogen inhalation attenuates lung contusion after blunt chest trauma in mice EN Kohei AGETA Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University No potential conflict of interest relevant to this article was reported.

Public Library of Science Acta Medica Okayama 1932-6203 19 3 2024 Chemical range recognized by the ligand-binding domain in a representative amino acid-sensing taste receptor, T1r2a/T1r3, from medaka fish e0300981 EN Hikaru Ishida Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Norihisa Yasui Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Atsuko Yamashita Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Taste receptor type 1 (T1r) proteins are responsible for recognizing nutrient chemicals in foods. In humans, T1r2/T1r3 and T1r1/T1r3 heterodimers serve as the sweet and umami receptors that recognize sugars or amino acids and nucleotides, respectively. T1rs are conserved among vertebrates, and T1r2a/T1r3 from medaka fish is currently the only member for which the structure of the ligand-binding domain (LBD) has been solved. T1r2a/T1r3 is an amino acid receptor that recognizes various l-amino acids in its LBD as observed with other T1rs exhibiting broad substrate specificities. Nevertheless, the range of chemicals that are recognized by T1r2a/T1r3LBD has not been extensively explored. In the present study, the binding of various chemicals to medaka T1r2a/T1r3LBD was analyzed. A binding assay for amino acid derivatives verified the specificity of this protein to l-alpha-amino acids and the importance of alpha-amino and carboxy groups for receptor recognition. The results further indicated the significance of the alpha-hydrogen for recognition as replacing it with a methyl group resulted in a substantially decreased affinity. The binding ability to the protein was not limited to proteinogenic amino acids, but also to non-proteinogenic amino acids, such as metabolic intermediates. Besides l-alpha-amino acids, no other chemicals showed significant binding to the protein. These results indicate that all of the common structural groups of alpha-amino acids and their geometry in the l-configuration are recognized by the protein, whereas a wide variety of alpha-substituents can be accommodated in the ligand binding sites of the LBDs. No potential conflict of interest relevant to this article was reported.

AIP Publishing Acta Medica Okayama 0021-9606 160 9 2024 GenIce-core: Efficient algorithm for generation of hydrogen-disordered ice structures 094101 EN Masakazu Matsumoto Research Institute for Interdisciplinary Science, Okayama University Takuma Yagasaki Division of Chemical Engineering, Graduate School of Engineering Science, Osaka University Hideki Tanaka Toyota Physical and Chemical Research Institute Ice is different from ordinary crystals because it contains randomness, which means that statistical treatment based on ensemble averaging is essential. Ice structures are constrained by topological rules known as the ice rules, which give them unique anomalous properties. These properties become more apparent when the system size is large. For this reason, there is a need to produce a large number of sufficiently large crystals that are homogeneously random and satisfy the ice rules. We have developed an algorithm to quickly generate ice structures containing ions and defects. This algorithm is provided as an independent software module that can be incorporated into crystal structure generation software. By doing so, it becomes possible to simulate ice crystals on a previously impossible scale. No potential conflict of interest relevant to this article was reported.

Elsevier BV Acta Medica Okayama 0020-1693 564 2024 Synthesis and characterization of iron(II) complex with unsymmetrical heterocyclic (2-pyridyl)(4-imidazolyl)azine 121937 EN Kennedy Mawunya Hayibor Yukinari Sunatsuki Takayoshi Suzuki A new iron(II) complex bearing unsymmetrical azine, [Fe(HLH)2](PF6)2·H2O·MeCN (HLH = 2-pyridylmethylidenehydrazono(4-imidazolyl)methane), was synthesized exclusively by a reaction of 2-pyridine carboxaldehyde, 1H-imidazole-4-carboxaldehyde, hydrazine monohydrate and FeCl2·4H2O (in a molar ratio of 2:2:2:1) in methanol, followed by the addition of an aqueous NH4PF6 solution. It was characterized using spectroscopic techniques, elemental analysis, magnetic measurement, and cyclic voltammetry. The molecular and crystal structure of the compound was revealed by X-ray analysis, where an iron(II) ion was surrounded by two HLH azines with a planar E(py),Z(im) conformation, and tridentate κ3N,N’,N” coordination mode, forming a monomeric six-coordinated and diamagnetic complex. The complex cations were linked by water molecules via intermolecular hydrogen-bonding interactions between the imidazole N−H and the neighboring uncoordinated azine-N atom, forming a 1D chain structure. The selective formation of this unsymmetrical azine (HLH) from a stoichiometric mixture of the components would result from the steric preference of the five- and six-membered chelate rings by the 2-pyridyl and 4-imidazolyl azine moieties, respectively, with the E(py),Z(im) configuration. No potential conflict of interest relevant to this article was reported.

IOP Publishing Acta Medica Okayama 0021-4922 63 3 2024 Evaluation of transducer for cryogenic actuators by equivalent circuit model 03SP03 EN Kazuki Kubo Graduate School of Environment, Life, Natural, Science and Technology, Okayama University Kairi Yagi Graduate School of Environment, Life, Natural, Science and Technology, Okayama University Takefumi Kanda Graduate School of Environment, Life, Natural, Science and Technology, Okayama University Koa Yasuda Graduate School of Environment, Life, Natural, Science and Technology, Okayama University Daisuke Yamaguchi Graduate School of Environment, Life, Natural, Science and Technology, Okayama University Shuichi Wakimoto Graduate School of Environment, Life, Natural, Science and Technology, Okayama University Cryogenic environments are increasingly used in scientific and industrial fields. Recently, cryogenic environments are also used for storage and supply of liquid hydrogen, which is considered essential for the realization of a decarbonized society. Actuators to drive a valve that controls such a low-temperature fluid are required. In this study, a piezoelectric transducer that can be driven in the cryogenic environment has been fabricated and evaluated. Although the performance of piezoelectric elements degrades at cryogenic temperatures in general, the application of a preload can suppress the degradation of performance. Equivalent circuits were used for evaluation, and force factors and figures of merit were compared. As a result, the force factor was as high as that at RT even at cryogenic temperatures, and a high figure of merit was obtained. The result indicates that the transducer can be used for the driving of micro actuator at cryogenic temperature. No potential conflict of interest relevant to this article was reported.

MDPI Acta Medica Okayama 1424-8220 24 2 2024 Ultrathin Platinum Film Hydrogen Sensors with a Twin-T Type Notch Filter Circuit 548 EN Shoki Wakabayashi Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University Yuki Oh Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University Haruhito Nakayama Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University Jin Wang Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University Toshihiko Kiwa Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University In recent years, hydrogen energy has garnered attention as a potential solution for mitigating greenhouse gas emissions. However, concerns regarding the inherent risk of hydrogen gas leakage and potential explosions have necessitated the development of advanced sensors. Within our research group, we have innovated an ultrathin platinum (Pt) film hydrogen sensor that gauges resistance changes in Pt thin films when exposed to hydrogen gas. Notably, the sensitivity of each sensor is contingent upon the thickness of the Pt film. To address the challenge of detecting hydrogen using multiple sensors, we integrated the ultrathin Pt film as a resistance element within a twin-T type notch filter. This filter exhibits a distinctive reduction in output signals at a specific frequency. The frequency properties of the notch filter dynamically alter with changes in the resistance of the Pt film induced by hydrogen exposure. Consequently, the ultrathin Pt film hydrogen sensor monitors output signal variations around the notch frequency, responding to shifts in frequency properties. This innovative approach enables the electrical control of sensor sensitivity by adjusting the operating frequency in proximity to the notch frequency. Additionally, the simultaneous detection of hydrogen by multiple sensors was successfully achieved by interconnecting sensors with distinct notch frequencies in series. No potential conflict of interest relevant to this article was reported.

MDPI Acta Medica Okayama 2227-9059 12 1 2024 Hydrogen in Transplantation: Potential Applications and Therapeutic Implications 118 EN Takafumi Obara Department of Emergency, Critical Care, and Disaster Medicine, Faculty of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University Hiromichi Naito Department of Emergency, Critical Care, and Disaster Medicine, Faculty of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University Tsuyoshi Nojima Department of Emergency, Critical Care, and Disaster Medicine, Faculty of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University Takahiro Hirayama Department of Emergency, Critical Care, and Disaster Medicine, Faculty of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University Takashi Hongo Department of Emergency, Critical Care, and Disaster Medicine, Faculty of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University Kohei Ageta Department of Emergency, Critical Care, and Disaster Medicine, Faculty of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University Toshiyuki Aokage Department of Emergency, Critical Care, and Disaster Medicine, Faculty of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University Masaki Hisamura Department of Emergency, Critical Care, and Disaster Medicine, Faculty of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University Tetsuya Yumoto Department of Emergency, Critical Care, and Disaster Medicine, Faculty of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University Atsunori Nakao Department of Emergency, Critical Care, and Disaster Medicine, Faculty of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University Hydrogen gas, renowned for its antioxidant properties, has emerged as a novel therapeutic agent with applications across various medical domains, positioning it as a potential adjunct therapy in transplantation. Beyond its antioxidative properties, hydrogen also exerts anti-inflammatory effects by modulating pro-inflammatory cytokines and signaling pathways. Furthermore, hydrogen's capacity to activate cytoprotective pathways bolsters cellular resilience against stressors. In recent decades, significant advancements have been made in the critical medical procedure of transplantation. However, persistent challenges such as ischemia-reperfusion injury (IRI) and graft rejection continue to hinder transplant success rates. This comprehensive review explores the potential applications and therapeutic implications of hydrogen in transplantation, shedding light on its role in mitigating IRI, improving graft survival, and modulating immune responses. Through a meticulous analysis encompassing both preclinical and clinical studies, we aim to provide valuable insights into the promising utility of hydrogen as a complementary therapy in transplantation. No potential conflict of interest relevant to this article was reported.

American Chemical Society (ACS) Acta Medica Okayama 1936-0851 18 1 2023 Close-Packed Ices in Nanopores 347 354 EN Kenji Mochizuki Department of Chemistry, Zhejiang University Yuji Adachi Graduate School of Natural Sciences, Okayama University Kenichiro Koga Department of Chemistry, Okayama University Water molecules in any of the ice polymorphs organize themselves into a perfect four-coordinated hydrogen-bond network at the expense of dense packing. Even at high pressures, there seems to be no way to reconcile the ice rules with the close packing. Here, we report several close-packed ice phases in carbon nanotubes obtained from molecular dynamics simulations of two different water models. Typically they are in plastic states at high temperatures and are transformed into the hydrogen-ordered ice, keeping their close-packed structures at lower temperatures. The close-packed structures of water molecules in carbon nanotubes are identified with those of spheres in a cylinder. We present design principles of hydrogen-ordered, close-packed structures of ice in nanotubes, which suggest many possible dense ice forms with or without nonzero polarization. In fact, some of the simulated ices are found to exhibit ferroelectric ordering upon cooling. No potential conflict of interest relevant to this article was reported.

Elsevier Acta Medica Okayama 0531-5565 180 2023 Attenuation of pulmonary damage in aged lipopolysaccharide-induced inflammation mice through continuous 2 % hydrogen gas inhalation: A potential therapeutic strategy for geriatric inflammation and survival 112270 EN Toshiyuki Aokage Department of Emergency, Critical Care and Disaster Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Masumi Iketani Biological Process of Aging, Tokyo Metropolitan Institute for Geriatrics and Gerontology Mizuki Seya Department of Emergency, Critical Care and Disaster Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Ying Meng Department of Emergency, Critical Care and Disaster Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Kohei Ageta Department of Emergency, Critical Care and Disaster Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Hiromichi Naito Department of Emergency, Critical Care and Disaster Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Atsunori Nakao Department of Emergency, Critical Care and Disaster Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Ikuroh Ohsawa Biological Process of Aging, Tokyo Metropolitan Institute for Geriatrics and Gerontology Introduction: With the global population aging, there is an increased prevalence of sepsis among the elderly, a demographic particularly susceptible to inflammation. This study aimed to evaluate the therapeutic potential of hydrogen gas, known for its anti-inflammatory and antioxidant properties, in attenuating inflammation specifically in the lungs and liver, and age-associated molecular markers in aged mice.<br> Methods: Male mice aged 21 to 23 months, representative of the human elderly population, were subjected to inflammation via intraperitoneal injection of lipopolysaccharide (LPS). The mice were allocated into eight groups to examine the effects of varying durations and concentrations of hydrogen gas inhalation: control, saline without hydrogen, saline with 24-hour 2 % hydrogen, LPS without hydrogen, LPS with 24-hour 2 % hydrogen, LPS with 6-hour 2 % hydrogen, LPS with 1-hour 2 % hydrogen, and LPS with 24-hour 1 % hydrogen. Parameters assessed included survival rate, activity level, inflammatory biomarkers, and organ injury.<br> Results: Extended administration of hydrogen gas specifically at a 2 % concentration for 24 h led to a favorable prognosis in the aged mice by reducing mRNA expression of inflammatory biomarkers in lung and liver tissue, mitigating lung injury, and diminishing the expression of the senescence-associated protein p21. Moreover, hydrogen gas inhalation selectively ameliorated senescence-related markers in lung tissue, including C-X-C motif chemokine 2, metalloproteinase-3, and arginase-1. Notably, hydrogen gas did not alleviate LPS-induced liver injury under the conditions tested.<br> Conclusion: The study highlights that continuous inhalation of hydrogen gas at a 2 % concentration for 24 h can be a potent intervention in the geriatric population for improving survival and physical activity by mitigating pulmonary inflammation and modulating senescence-related markers in aged mice with LPS-induced inflammation. This finding paves the way for future research into hydrogen gas as a therapeutic strategy to alleviate severe inflammation that can lead to organ damage in the elderly. No potential conflict of interest relevant to this article was reported.

MDPI Acta Medica Okayama 2075-4701 13 8 2023 Microstructural Control and Alloy Design for Improving the Resistance to Delayed Fracture of Ultrahigh-Strength Automotive Steel Sheets 1368 EN Takehide Senuma Department of Mechanical and Systems Engineering, Okayama University Mitsuhiro Okayasu Department of Mechanical and Systems Engineering, Okayama University Hardy Mohrbacher NiobelCon BV The demand for higher-strength automotive steel sheets has increased significantly for lightweight and safe body concepts. However, the increment of the steel strength is often limited by the potential occurrence of delayed fracture. This paper discusses proper microstructure control and alloy design to improve the resistance against the delayed fracture of ultrahigh-strength automotive steel sheets in order to increase the usable upper limit of their strength and provides basic data serving as a practical guide for solving the problem of delayed fracture in ultrahigh-strength automotive steel sheets. It is confirmed that grain refinement, the appropriate dual-phase structure of martensite with ferrite or retained austenite, and surface decarburization, increase the resistance to delayed fracture. In terms of alloy design, the effects of Nb, Mo, and B on the delayed fracture resistance of hot-stamped steels have been investigated. The results suggest that there are other reasons for Nb to improve delayed fracture resistance in addition to grain refinement and the ability to trap hydrogen by its precipitates, as has been conventionally believed. Regarding Mo, it was clearly demonstrated that the segregation of this element at the grain boundary plays a main role in improving the delayed fracture resistance. No potential conflict of interest relevant to this article was reported.

Okayama University Medical School Acta Medica Okayama 0386-300X 77 4 2023 Association of Tumor Necrosis Factor-Alpha with Psychopathology in Patients with Schizophrenia 395 405 EN Marko Pavlovic University Hospital Center Mostar, University of Mostar Dragan Babic University Hospital Center Mostar, University of Mostar Pejana Rastovic University Hospital Center Mostar, University of Mostar Jurica Arapovic University Hospital Center Mostar, University of Mostar Marko Martinac Health Care Center Mostar, University of Mostar Sanja Jakovac University Hospital Center Mostar, University of Mostar Romana Barbaric University Hospital Center Mostar, University of Mostar Original Article 10.18926/AMO/65750 We investigated the relationship between serum tumor necrosis factor-alpha (TNF-α) levels and psychopathological symptoms, clinical and socio-demographic characteristics and antipsychotic therapy in individuals with schizophrenia. TNF-α levels were measured in 90 patients with schizophrenia and 90 healthy controls matched by age, gender, smoking status, and body mass index. The Positive and Negative Syndrome Scale (PANSS) was used to assess the severity of psychopathology in patients. No significant differences in TNF-α levels were detected between the patients and controls (p=0.736). TNF-α levels were not correlated with total, positive, negative, general, or composite PANSS scores (all p>0.05). A significant negative correlation was observed between TNF-α levels and the PANSS cognitive factor (ρ=−0.222, p=0.035). A hierarchical regression analysis identified the cognitive factor as a significant predictor of the TNF-α level (beta=−0.258, t=−2.257, p=0.027). There were no significant differences in TNF-α levels among patients treated with different types of antipsychotics (p=0.596). TNF-α levels correlated positively with the age of onset (ρ=0.233, p=0.027) and negatively with illness duration (ρ=−0.247, p=0.019) and antipsychotic treatment duration (ρ=−0.256, p=0.015). These results indicate that TNF-α may be involved in cognitive impairment in schizophrenia, and would be a potential clinical-state marker in schizophrenia. No potential conflict of interest relevant to this article was reported.

MDPI Acta Medica Okayama 2076-3921 12 7 2023 Combined Effect of Salicylic Acid and Proline Mitigates Drought Stress in Rice (Oryza sativa L.) through the Modulation of Physiological Attributes and Antioxidant Enzymes 1438 EN Tahmina Akter Urmi Department of Soil Science, Faculty of Agriculture, Bangladesh Agricultural University Md. Moshiul Islam Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Kamrun Naher Zumur Department of Agronomy, Faculty of Agriculture, Bangabandhu Sheikh Mujibur Rahman Agricultural University Md. Anwarul Abedin Department of Soil Science, Faculty of Agriculture, Bangladesh Agricultural University M. Moynul Haque Department of Agronomy, Faculty of Agriculture, Bangabandhu Sheikh Mujibur Rahman Agricultural University Manzer H. Siddiqui Department of Botany and Microbiology, College of Science, King Saud University Yoshiyuki Murata Graduate School of Environmental, Life, Natural Science and Technology, Okayama University Md. Anamul Hoque Department of Soil Science, Faculty of Agriculture, Bangladesh Agricultural University Salicylic acid (SA) and proline exhibit protective effects against a wide range of stresses. However, the combined impact of SA and proline on rice under drought stress is still unknown. Therefore, we investigated the protective roles of SA and/or proline in conferring drought tolerance in rice. There were eight treatments comprising the control (T1; 95-100% FC), 1.5 mM SA (T2), 2 mM proline (T3), 0.75 mM SA + 1 mM proline (T4), 45-50% FC (T5, drought stress), T5 + 1.5 mM SA (T6), T5 + 2 mM proline (T7), and T5 + 0.75 mM SA + 1 mM proline (T8), and two rice varieties: BRRI dhan66 and BRRI dhan75. Drought stress significantly decreased the plant growth, biomass, yield attributes, photosynthetic rate (Pn), stomatal conductance (gs), transpiration rate (Tr), photosynthetic pigments (chlorophyll and carotenoids content), relative water content (RWC), membrane stability index (MSI), soluble sugar and starch content, and uptake of N, P and K+ in roots and shoots. Drought-induced oxidative stress in the form of increased hydrogen peroxide (H2O2) production and lipid peroxidation (MDA) was observed. The combined application of SA (0.75 mM) + proline (1 mM) was found to be more effective than the single application of either for drought stress mitigation in rice. A combined dose of SA + proline alleviated oxidative stress through boosting antioxidant enzymatic activity in contrast to their separate application. The application of SA + proline also enhanced proline, soluble sugar and starch content, which resulted in the amelioration of osmotic stress. Consequently, the combined application of SA and proline significantly increased the gas exchange characteristics, photosynthetic pigments, RWC, MSI, nutrient uptake, plant growth, biomass and yield of rice. Therefore, the combined application of SA and proline alleviated the detrimental impacts of drought stress more pronouncedly than their separate application did by increasing osmoprotectants, improving nutrient transport, up-regulating antioxidant enzyme activity and inhibiting oxidative stress. No potential conflict of interest relevant to this article was reported.

Wiley Acta Medica Okayama 1347-9032 114 10 2023 Combination therapy with hydrogen peroxide and irradiation promotes an abscopal effect in mouse models 3848 3856 EN Naoya Kemmotsu Department of Tumor Microenvironment, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Li Zhu Department of Tumor Microenvironment, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Joji Nagasaki Department of Tumor Microenvironment, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Yoshihiro Otani Department of Neurological Surgery, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Youki Ueda Department of Tumor Microenvironment, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Hiromichi Dansako Department of Tumor Microenvironment, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Yue Fang Department of Microbial and Biochemical Pharmacy, School of Pharmacy, China Medical University Isao Date Department of Neurological Surgery, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Yosuke Togashi Department of Tumor Microenvironment, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Hydrogen peroxide (H2O2) induces oxidative stress and cytotoxicity, and can be used for treating cancers in combination with radiotherapy. A product comprising H2O2 and sodium hyaluronate has been developed as a radiosensitizer. However, the effects of H2O2 on antitumor immunity remain unclear. To investigate the effects of H2O2, especially the abscopal effect when combined with radiotherapy (RT), we implanted murine tumor cells simultaneously in two locations in mouse models: the hind limb and back. H2O2 mixed with sodium hyaluronate was injected intratumorally, followed by irradiation only at the hind limb lesion. No treatment was administered to the back lesion. The H2O2/RT combination significantly reduced tumor growth at the noninjected/nonirradiated site in the back lesion, whereas H2O2 or RT individually did not reduce tumor growth. Flow cytometric analyses of the tumor-draining lymph nodes in the injected/irradiated areas showed that the number of dendritic cells increased significantly with maturation in the H2O2/RT combination group. In addition, analyses of tumor-infiltrating lymphocytes showed that the number of CD8+ (cluster of differentiation 8) T cells and the frequency of IFN-γ+ (interferon gamma) CD8+ T cells were higher in the noninjected/nonirradiated tumors in the H2O2/RT group compared to those in the other groups. PD-1 (programmed death receptor 1) blockade further increased the antitumor effect against noninjected/nonirradiated tumors in the H2O2/RT group. Intratumoral injection of H2O2 combined with RT therefore induces an abscopal effect by activating antitumor immunity, which can be further enhanced by PD-1 blockade. These findings promote the development of H2O2/RT therapy combined with cancer immunotherapies, even for advanced cancers. No potential conflict of interest relevant to this article was reported.

Oxford University Press (OUP) Acta Medica Okayama 0032-0889 189 1 2022 Photosystem I light-harvesting proteins regulate photosynthetic electron transfer and hydrogen production 329 343 EN Thi Thu Hoai Ho Institute of Plant Biology and Biotechnology, University of Münster Chris Schwier Institute of Plant Biology and Biotechnology, University of Münster Tamar Elman School of Plant Sciences and Food Security, The George S. Wise Faculty of Life Sciences, Tel Aviv University Vera Fleuter Institute of Plant Biology and Biotechnology, University of Münster Karen Zinzius Institute of Plant Biology and Biotechnology, University of Münster Martin Scholz Institute of Plant Biology and Biotechnology, University of Münster Iftach Yacoby School of Plant Sciences and Food Security, The George S. Wise Faculty of Life Sciences, Tel Aviv University Felix Buchert Institute of Plant Biology and Biotechnology, University of Münster Michael Hippler Institute of Plant Science and Resources, Okayama University Linear electron flow (LEF) and cyclic electron flow (CEF) compete for light-driven electrons transferred from the acceptor side of photosystem I (PSI). Under anoxic conditions, such highly reducing electrons also could be used for hydrogen (H2) production via electron transfer between ferredoxin and hydrogenase in the green alga Chlamydomonas reinhardtii. Partitioning between LEF and CEF is regulated through PROTON-GRADIENT REGULATION5 (PGR5). There is evidence that partitioning of electrons also could be mediated via PSI remodeling processes. This plasticity is linked to the dynamics of PSI-associated light-harvesting proteins (LHCAs) LHCA2 and LHCA9. These two unique light-harvesting proteins are distinct from all other LHCAs because they are loosely bound at the PSAL pole. Here, we investigated photosynthetic electron transfer and H2 production in single, double, and triple mutants deficient in PGR5, LHCA2, and LHCA9. Our data indicate that lhca2 and lhca9 mutants are efficient in photosynthetic electron transfer, that LHCA2 impacts the pgr5 phenotype, and that pgr5/lhca2 is a potent H2 photo-producer. In addition, pgr5/lhca2 and pgr5/lhca9 mutants displayed substantially different H2 photo-production kinetics. This indicates that the absence of LHCA2 or LHCA9 impacts H2 photo-production independently, despite both being attached at the PSAL pole, pointing to distinct regulatory capacities. No potential conflict of interest relevant to this article was reported.

Elsevier Acta Medica Okayama 0039-6060 174 2 2023 Hydrogen inhalation attenuates lung contusion after blunt chest trauma in mice 343 349 EN Kohei Ageta Department of Emergency, Critical Care, and Disaster Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Takahiro Hirayama Department of Emergency, Critical Care, and Disaster Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Toshiyuki Aokage Department of Emergency, Critical Care, and Disaster Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Mizuki Seya Department of Emergency, Critical Care, and Disaster Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Ying Meng Department of Emergency, Critical Care, and Disaster Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Tsuyoshi Nojima Department of Emergency, Critical Care, and Disaster Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Hirotsugu Yamamoto Department of Emergency, Critical Care, and Disaster Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Takafumi Obara Department of Emergency, Critical Care, and Disaster Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Atsunori Nakao Department of Emergency, Critical Care, and Disaster Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Tetsuya Yumoto Department of Emergency, Critical Care, and Disaster Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Kohei Tsukahara Department of Emergency, Critical Care, and Disaster Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Hiromichi Naito Department of Emergency, Critical Care, and Disaster Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Background: Lung contusion caused by blunt chest trauma evokes a severe inflammatory reaction in the pulmonary parenchyma that may be associated with acute respiratory distress syndrome. Although hydrogen gas has antioxidant and anti-inflammatory effects and is protective against multiple types of lung injury at safe concentrations, the effects of inhaled hydrogen gas on blunt lung injury have not been previously investigated. Therefore, using a mouse model, we tested the hypothesis that hydrogen inhalation after chest trauma would reduce pulmonary inflammation and acute lung injury associated with lung contusion.<br> Methods: Inbred male C57BL/6 mice were randomly divided into 3 groups: sham with air inhalation, lung contusion with air inhalation, and lung contusion with 1.3% hydrogen inhalation. Experimental lung contusion was induced using a highly reproducible and standardized apparatus. Immediately after induction of lung contusion, mice were placed in a chamber exposed to 1.3% hydrogen gas in the air. Histopathological analysis and real-time polymerase chain reaction in lung tissue and blood gas analysis were performed 6 hours after contusion.<br> Results: Histopathological examination of the lung tissue after contusion revealed perivascular/intra-alveolar hemorrhage, perivascular/interstitial leukocyte infiltration, and interstitial/intra-alveolar edema. These histological changes and the extent of lung contusion, as determined by computed tomography, were significantly mitigated by hydrogen inhalation. Hydrogen inhalation also significantly reduced inflammatory cytokine and chemokine mRNA levels and improved oxygenation.<br> Conclusion: Hydrogen inhalation therapy significantly mitigated inflammatory responses associated with lung contusion in mice. Hydrogen inhalation therapy may be a supplemental therapeutic strategy for treating lung contusion. No potential conflict of interest relevant to this article was reported.

Frontiers Media Acta Medica Okayama 2296-634X 11 2023 Mutagenic analysis of actin reveals the mechanism of His161 flipping that triggers ATP hydrolysis 1105460 EN Mitsusada Iwasa Graduate School of Informatics, Nagoya University Shuichi Takeda Research Institute for Interdisciplinary Science (RIIS), Okayama University Akihiro Narita Structural Biology Research Center, Graduate School of Science, Nagoya University Yuichiro Maeda Research Institute for Interdisciplinary Science (RIIS), Okayama University Toshiro Oda Faculty of Health and Welfare, Tokai Gakuin University The dynamic assembly of actin is controlled by the hydrolysis of ATP, bound to the center of the molecule. Upon polymerization, actin undergoes a conformational change from the monomeric G-form to the fibrous F-form, which is associated with the flipping of the side chain of His161 toward ATP. His161 flipping from the gauche-minus to gauche-plus conformation leads to a rearrangement of the active site water molecules, including ATP attacking water (W1), into an orientation capable of hydrolysis. We previously showed that by using a human cardiac muscle a-actin expression system, mutations in the Pro-rich loop residues (A108G and P109A) and in a residue that was hydrogen-bonded to W1 (Q137A) affect the rate of polymerization and ATP hydrolysis. Here, we report the crystal structures of the three mutant actins bound to AMPPNP or ADP-P-i determined at a resolution of 1.35-1.55( )angstrom, which are stabilized in the F-form conformation with the aid of the fragmin F1 domain. In A108G, His161 remained non-flipped despite the global actin conformation adopting the F-form, demonstrating that the side chain of His161 is flipped to avoid a steric clash with the methyl group of A108. Because of the non-flipped His161, W1 was located away from ATP, similar to G-actin, which was accompanied by incomplete hydrolysis. In P109A, the absence of the bulky proline ring allowed His161 to be positioned near the Pro-rich loop, with a minor influence on ATPase activity. In Q137A, two water molecules replaced the side-chain oxygen and nitrogen of Gln137 almost exactly at their positions; consequently, the active site structure, including the W1 position, is essentially conserved. This seemingly contradictory observation to the reported low ATPase activity of the Q137A filament could be attributed to a high fluctuation of the active site water. Together, our results suggest that the elaborate structural design of the active site residues ensures the precise control of the ATPase activity of actin. No potential conflict of interest relevant to this article was reported.

SAGE Publications Acta Medica Okayama 1721-727X 21 2023 Hydrogen gas treatment improves survival in a rat model of crush syndrome by ameliorating rhabdomyolysis EN Tetsuya Yumoto Department of Emergency, Critical Care, and Disaster Medicine, Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Toshiyuki Aokage Department of Emergency, Critical Care, and Disaster Medicine, Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Takahiro Hirayama Department of Emergency, Critical Care, and Disaster Medicine, Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Hirotsugu Yamamoto Department of Emergency, Critical Care, and Disaster Medicine, Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Takafumi Obara Department of Emergency, Critical Care, and Disaster Medicine, Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Tsuyoshi Nojima Department of Emergency, Critical Care, and Disaster Medicine, Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Hiromichi Naito Department of Emergency, Critical Care, and Disaster Medicine, Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Atsunori Nakao Department of Emergency, Critical Care, and Disaster Medicine, Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Objectives: Crush syndrome (CS) is characterized by a systemic manifestation of traumatic rhabdomyolysis, leading to multiple organ dysfunction and death. Ischemia-reperfusion (IR) injury is commonly responsible for systemic response. Extending studies have shown that hydrogen gas treatment ameliorated IR injury in numerous experimental models; however, its effect on CS has not been well examined. This study aimed to investigate the effects of hydrogen gas inhalation following crush injury in an experimental model of CS.<br> Methods: Male Sprague-Dawley rats were subjected to experimental CS by applying a total of 3.0 kg weight to both hindlimb under general anesthesia for 6 h. Immediately after decompression, the animals were randomly placed in a gas chamber filled with either air or 1.3% hydrogen gas. Animals were sacrificed 18 h or 24 h following gas exposure for non-survival studies or for survival study, respectively.<br> Results: The rats with hydrogen treatment (n = 6) had a higher 24-h survival than the rats with air treatment (n = 9) (100% vs. 44%, p = 0.035). Lactate concentrations (2.9 +/- 0.2 vs. 2.2 +/- 0.2 mmol/L, p = 0.040) and creatine kinase (34,178 +/- 13,580 vs. 5005 +/- 842 IU/L, p = 0.016) were lower in the hydrogen group compared with the air group 18 h after decompression (n = 4 in the air group, and n = 5 in the H-2 group). Histological analysis revealed that the damage to the rectus femoris muscle and kidney appeared to be ameliorated by hydrogen treatment.<br> Conclusion: Hydrogen gas inhalation may be a promising therapeutic approach in the treatment of CS. No potential conflict of interest relevant to this article was reported.

岡山大学農学部 Acta Medica Okayama 2186-7755 112 2023 Streptomyces属放線菌由来の高基質特異性l-グルタミン酸オキシダーゼに関する研究 13 18 EN Natsume Nakayama Course of Agrochemical Bioscience K. Inagaki l-glutamate oxidase (LGOX) from Streptomyces sp. is a heterohexameric flavin enzyme that catalyzes the oxidative deamination of l-glutamate to form α-ketoglutarate with ammonia and hydrogen peroxide. LGOX shows strict substrate specificity for l-Glu. In addition, it is highly thermostable and pH stable. Because of these properties, LGOX is currently used as a biosensor for the trace determination of l-Glu in the food industry and clinical laboratories. The full-length cDNA is 2103 bp and is encoded by a single polypeptide chain consisting of 701 residues including subunits α-γ-β. The LGOX gene was heterologously expressed in Escherichia coli JM109. The LGOX precursor expressed in E. coli is a homodimer with weak enzymatic activity and becomes a heterohexamer upon activation by protease treatment. X-ray crystallography and docking studies of purified recombinant LGOX suggest that the Arg305 residue is a key residue for substrate recognition. Mutant analysis showed that Arg305 is essential for substrate recognition, as the activity toward l-Glu was greatly reduced and substrate specificity was changed in some enzymes. The functional analysis of R305E-LGOX, which is an l-Arg oxidase, revealed that R305E-LGOX can be used as a enzyme biosensor for l-Arg. No potential conflict of interest relevant to this article was reported.

MDPI Acta Medica Okayama 1422-0067 24 1 2023 Cycloartenyl Ferulate Is the Predominant Compound in Brown Rice Conferring Cytoprotective Potential against Oxidative Stress-Induced Cytotoxicity 822 EN Hongyan Wu School of Food Science and Technology, Dalian Polytechnic University Toshiyuki Nakamura Graduate School of Environmental and Life Science, Okayama University Yingnan Guo School of Food Science and Technology, Dalian Polytechnic University Riho Matsumoto Graduate School of Environmental and Life Science, Okayama University Shintaro Munemasa Graduate School of Environmental and Life Science, Okayama University Yoshiyuki Murata Graduate School of Environmental and Life Science, Okayama University Yoshimasa Nakamura Graduate School of Environmental and Life Science, Okayama University Since brown rice extract is a rich source of biologically active compounds, the present study is aimed to quantify the major compounds in brown rice and to compare their cytoprotective potential against oxidative stress. The content of the main hydrophobic compounds in brown rice followed the order of cycloartenyl ferulate (CAF) (89.00 +/- 8.07 nmol/g) >> alpha-tocopherol (alpha T) (19.73 +/- 2.28 nmol/g) > gamma-tocotrienol (gamma T3) (18.24 +/- 1.41 nmol/g) > alpha-tocotrienol (alpha T3) (16.02 +/- 1.29 nmol/g) > gamma-tocopherol (gamma T) (3.81 +/- 0.40 nmol/g). However, the percent contribution of CAF to the radical scavenging activity of one gram of whole brown rice was similar to those of alpha T, alpha T3, and gamma T3 because of its weaker antioxidant activity. The CAF pretreatment displayed a significant cytoprotective effect on the hydrogen peroxide-induced cytotoxicity from 10 mu M, which is lower than the minimal concentrations of alpha T and gamma T required for a significant protection. CAF also enhanced the nuclear factor erythroid 2-related factor 2 (Nrf2) nuclear translocation coincided with the enhancement of the heme oxygenase-1 (HO-1) mRNA level. An HO-1 inhibitor, tin protoporphyrin IX (SnPP), significantly impaired the cytoprotection of CAF. The cytoprotective potential of CAF is attributable to its cycloartenyl moiety besides the ferulyl moiety. These results suggested that CAF is the predominant cytoprotector in brown rice against hydrogen peroxide-induced cytotoxicity. No potential conflict of interest relevant to this article was reported.

Elsevier Acta Medica Okayama 1083-351X 298 12 2022 Crystal structures of photosystem II from a cyanobacterium expressing psbA2 in comparison to psbA3 reveal differences in the D1 subunit 102668 EN Yoshiki Nakajima Research Institute for Interdisciplinary Science, Okayama University Natsumi Ugai-Amo Graduate School of Natural Science and Technology, Okayama University Naoki Tone Graduate School of Natural Science and Technology, Okayama University Akiko Nakagawa Proteo-Science Research Center, Ehime University Masako Iwai Graduate School and College of Arts and Sciences, The University of Tokyo Masahiko Ikeuchi Graduate School and College of Arts and Sciences, The University of Tokyo Miwa Sugiura Proteo-Science Research Center, Ehime University Michihiro Suga Research Institute for Interdisciplinary Science, Okayama University Shen Jian-Ren Research Institute for Interdisciplinary Science, Okayama University Three psbA genes (psbA1, psbA2, and psbA3) encoding the D1 subunit of photosystem II (PSII) are present in the ther-mophilic cyanobacterium Thermosynechococcus elongatus and are expressed differently in response to changes in the growth environment. To clarify the functional differences of the D1 protein expressed from these psbA genes, PSII dimers from two strains, each expressing only one psbA gene (psbA2 or psbA3), were crystallized, and we analyzed their structures at resolu-tions comparable to previously studied PsbA1-PSII. Our results showed that the hydrogen bond between pheophytin/D1 (PheoD1) and D1-130 became stronger in PsbA2-and PsbA3-PSII due to change of Gln to Glu, which partially explains the increase in the redox potential of PheoD1 observed in PsbA3. In PsbA2, one hydrogen bond was lost in PheoD1 due to the change of D1-Y147F, which may explain the decrease in stability of PheoD1 in PsbA2. Two water molecules in the Cl-1 channel were lost in PsbA2 due to the change of D1-P173M, leading to the narrowing of the channel, which may explain the lower efficiency of the S-state transition beyond S2 in PsbA2-PSII. In PsbA3-PSII, a hydrogen bond between D1-Ser270 and a sulfoquinovosyl-diacylglycerol molecule near QB dis-appeared due to the change of D1-Ser270 in PsbA1 and PsbA2 to D1-Ala270. This may result in an easier exchange of bound QB with free plastoquinone, hence an enhancement of oxygen evolution in PsbA3-PSII due to its high QB exchange efficiency. These results provide a structural basis for further functional examination of the three PsbA variants. No potential conflict of interest relevant to this article was reported.

Elsevier BV Acta Medica Okayama 0010-8545 471 2022 Geometric, electronic and spin structures of the CaMn4O5 catalyst for water oxidation in oxygen-evolving photosystem II. Interplay between experiments and theoretical computations 214742 EN Kizashi Yamaguchi Center for Quantum Information and Quantum Biology, Osaka University Mitsuo Shoji Center of Computational Sciences, Tsukuba University Hiroshi Isobe Research Institute for Interdisciplinary Science, and Graduate School of Natural Science and Technology, Okayama University Takashi Kawakami RIKEN Center for Computational Science Koichi Miyagawa Center of Computational Sciences, Tsukuba University Michihiro Suga Research Institute for Interdisciplinary Science, and Graduate School of Natural Science and Technology, Okayama University Fusamichi Akita Research Institute for Interdisciplinary Science, and Graduate School of Natural Science and Technology, Okayama University Jian-Ren Shen Research Institute for Interdisciplinary Science, and Graduate School of Natural Science and Technology, Okayama University The aim of this review is to elucidate geometric structures of the catalytic CaMn4Ox (x = 5, 6) cluster in the Kok cycle for water oxidation in the oxygen evolving complex (OEC) of photosystem II (PSII) based on the high-resolution (HR) X-ray diffraction (XRD) and serial femtosecond crystallography (SFX) experiments using the X-ray free-electron laser (XFEL). Quantum mechanics (QM) and QM/molecular mechanics (MM) computations are performed to elucidate the electronic and spin structures of the CaMn4Ox (x = 5, 6) cluster in five states S-i (i = 0 similar to 4) on the basis of the X-ray spectroscopy, electron paramagnetic resonance (EPR) and related experiments. Interplay between the experiments and theoretical computations has been effective to elucidate the coordination structures of the CaMn4Ox (x = 5, 6) cluster ligated by amino acid residues of the protein matrix of PSII, valence states of the four Mn ions and total spin states by their exchange-couplings, and proton-shifted isomers of the CaMn4Ox (x = 5, 6) cluster. The HR XRD and SFX XFEL experiments have also elucidated the biomolecular systems structure of OEC of PSII and the hydrogen bonding networks consisting of water molecules, chloride anions, etc., for water inlet and proton release pathways in PSII. Large-scale QM/MM computations have been performed for elucidation of the hydrogen bonding distances and angles by adding invisible hydrogen atoms to the HR XRD structure. Full geometry optimizations by the QM and QM/MM methods have been effective for elucidation of the molecular systems structure around the CaMn4Ox (x = 5, 6) cluster in OEC. DLPNO-CCSD(T-0) method has been applied to elucidate relative energies of possible intermediates in each state of the Kok cycle for water oxidation. Implications of these results are discussed in relation to the blueprint for developments of artificial catalysts for water oxidation. No potential conflict of interest relevant to this article was reported.

MDPI Acta Medica Okayama 1420-3049 27 20 2022 Selective Formation of Unsymmetric Multidentate Azine-Based Ligands in Nickel(II) Complexes 6788 EN Kennedy Mawunya Hayibor Graduate School of Natural Science and Technology, Okayama University Yukinari Sunatsuki Advanced Science Research Center, Okayama University Takayoshi Suzuki Graduate School of Natural Science and Technology, Okayama University A mixture of 2-pyridine carboxaldehyde, 4-formylimidazole (or 2-methyl-4-formylimidazole), and NiCl2 center dot 6H(2)O in a molar ratio of 2:2:1 was reacted with two equivalents of hydrazine monohydrate in methanol, followed by the addition of aqueous NH4PF6 solution, afforded a Ni-II complex with two unsymmetric azine-based ligands, [Ni(HLH)(2)](PF6)(2) (1) or [Ni(HLMe)(2)](PF6)(2) (2), in a high yield, where HLH denotes 2-pyridylmethylidenehydrazono-(4-imidazolyl)methane and HLMe is its 2-methyl-4-imidazolyl derivative. The spectroscopic measurements and elemental analysis confirmed the phase purity of the bulk products, and the single-crystal X-ray analysis revealed the molecular and crystal structures of the Ni-II complexes bearing an unsymmetric HLH or HLMe azines in a tridentate kappa(3) N, N', N" coordination mode. The HLH complex with a methanol solvent, 1 center dot MeOH, crystallizes in the orthorhombic non-centrosymmetric space group P2(1)2(1)2(1) with Z = 4, affording conglomerate crystals, while the HLMe complex, 2 center dot H2O center dot Et2O, crystallizes in the monoclinic and centrosymmetric space group P2(1)/n with Z = 4. In the crystal of 2 center dot H2O center dot Et2O, there is intermolecular hydrogen-bonding interaction between the imidazole N-H and the neighboring uncoordinated azine-N atom, forming a one-dimensional polymeric structure, but there is no obvious magnetic interaction among the intra- and interchain paramagnetic Ni-II ions. No potential conflict of interest relevant to this article was reported.

Beilstein-Institut Acta Medica Okayama 1860-5397 18 2022 Electrochemical hydrogenation of enones using a proton- exchange membrane reactor: selectivity and utility 1055 1061 EN Koichi Mitsudo Division of Applied Chemistry, Graduate School of Natural Science and Technology, Okayama University Haruka Inoue Division of Applied Chemistry, Graduate School of Natural Science and Technology, Okayama University Yuta Niki Division of Applied Chemistry, Graduate School of Natural Science and Technology, Okayama University Eisuke Sato Division of Applied Chemistry, Graduate School of Natural Science and Technology, Okayama University Seiji Suga Division of Applied Chemistry, Graduate School of Natural Science and Technology, Okayama University Electrochemical hydrogenation of enones using a proton-exchange membrane reactor is described. The reduction of enones proceeded smoothly under mild conditions to afford ketones or alcohols. The reaction occurred chemoselectively with the use of different cathode catalysts (Pd/C or Ir/C). No potential conflict of interest relevant to this article was reported.

Springer Science and Business Media LLC Acta Medica Okayama 0910-6340 38 4 2022 N-Benzoyl leucomethylene blue as a novel substrate for the assays of horseradish peroxidase by spectrophotometry and capillary electrophoresis–laser-induced fluorometry 651 655 EN Jianchao Ren Department of Chemistry, Graduate School of Natural Science and Technology, Okayama University Takashi Kaneta Department of Chemistry, Graduate School of Natural Science and Technology, Okayama University Horseradish peroxidase (HRP) is an enzyme that is frequently employed in various assays because HRP catalyzes the oxidation reactions of chromogenic and fluorogenic compounds to produce chromophores and fluorophores, respectively. The results of this study show that N-benzoyl leucomethylene blue (BLMB) is an excellent substrate for enzyme assay using HRP. In the presence of hydrogen peroxide (H2O2), HRP catalyzed an oxidation reaction of BLMB that produced methylene blue with a deep blue color. Thus, absorption spectrophotometry and capillary electrophoresis-laser-induced fluorometry (CE-LIF) could be used to easily determine the produced methylene blue. Under the optimum conditions, absorption spectrophotometry showed a linear calibration curve that ranged from 25 to 500 mu g mL(-1). The reaction conditions were also applicable to CE-LIF, showing a linear range of from 25 to 500 mu g mL(-1) with limits of detection and quantification at 2 and 6 mu g mL(-1), respectively. No potential conflict of interest relevant to this article was reported.

Elsevier BV Acta Medica Okayama 0026-265X 179 2022 Determination of glutamate using paper-based microfluidic devices with colorimetric detection for food samples 107513 EN Kaewta Danchana Department of Chemistry, Graduate School of Natural Science and Technology, Okayama University Hiroshi Iwasaki Department of Chemistry, Graduate School of Natural Science and Technology, Okayama University Kenta Ochiai Department of Chemistry, Graduate School of Natural Science and Technology, Okayama University Haruka Namba Department of Chemistry, Graduate School of Natural Science and Technology, Okayama University Takashi Kaneta Department of Chemistry, Graduate School of Natural Science and Technology, Okayama University A paper-based device (PAD) capable of colorimetric detection was developed to determine the presence of glutamate in various food samples. The PAD employs an enzymatic reaction with glutamate followed by an oxidation reaction with N-benzoyl leucomethylene blue (BLMB) in the presence of horseradish peroxidase. The designed PAD consists of a sample introduction zone connected to a channel that transports a sample solution to three detection zones. The detection zones contain pre-deposited reagents: glutamate oxidase, horseradish peroxidase, BLMB, a phosphate buffer, and poly(acrylic acid). The PAD is perpendicularly immersed into a sample solution and bent at a right angle using a 3D-printed holder to allow the sample to simultaneously flow into three different detection zones. When the PAD is immersed into a sample containing glutamate, glutamate oxidase produces hydrogen peroxide, which changes the pale blue color of BLMB to a deep blue color in the presence of horseradish peroxidase. Under the optimum conditions, the calibration curve between the logarithm of the glutamate concentrations and the color intensity was linear within a range of from 5 x 10(-6) mol L-1 to 10(-2) and with a correlation coefficient of 0.994. Using this system, the PAD successfully determined glutamate in soup stocks, sauces, snacks, and tomato juice without the need of complicated sample pretreatment. These results agreed with those of a commercially available glutamate assay kit, which was employed as a certification method (t(stat )= 1.95, t(crit )= 2.57). The developed PAD is simple, easy to fabricate, portable, and could be used outside of equipped laboratories to determine the presence of glutamate in food samples. No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 2022 Industrial Asymmetric Hydrogenation Processes for Chiral Drug Substances EN Masatoshi Yamada Graduate School of Natural Science and Technology, Okayama university No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 2022 The effects of inhaling hydrogen gas on macrophage polarization, fibrosis, and lung function in mice with bleomycin-induced lung injury EN Toshiyuki Aokage Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 2022 Luminal preloading with hydrogen-rich saline ameliorates ischemia-reperfusion injury following intestinal transplantation in rats EN Hirotsugu Yamamoto Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University No potential conflict of interest relevant to this article was reported.

岡山大学農学部 Acta Medica Okayama 2186-7755 111 2022 糸状菌Trichoderma viride由来の抗腫瘍性酵素L-リシン α-オキシダーゼに関する研究 7 14 EN Masaya Saito Course of Agrochemical Bioscience Kenji Inagaki L-Lysine α-oxidase (LysOX) from Trichoderma viride is a homodimeric flavoenzyme that catalyzes the oxidative deamination of L-Lysine to produce α-keto-ε-aminocaproate with ammonia and hydrogen per-oxide. LysOX inhibited the growth of cancer cells but showed relatively low toxicity for normal cells. The full-length cDNA consists of 2,119 bp, and encodes a long N-terminal propeptide composed of 77 resi-dues (Met1-Arg77) and the mature protein (Ala78-Ile617). The LysOX gene was heterologously expressed in Streptomyces lividans TK24 or Escherichia coli SoluBL21. The enzymatic properties of the purified recombinant LysOX, such as substrate specificity, kinetic parameters and thermal stability, are the same as those of the native LysOX. The LysOX precursor (prLysOX) expressed in E. coli shows weak enzymatic activity and is activated by proteolytic processing. The crystal structure of prLysOX revealed that the propeptide of prLysOX indirectly changes the active site structure to inhibit enzyme activity. Moreover, the crystal structures of LysOX and its L-Lysine complex revealed that the hydrogen bonding network formed by Asp212, Asp315 and Ala440 with two water molecules is responsible for the recogni-tion of the ε-amino group of L-Lysine. In addition, a narrow substrate-binding site and acidic surface at the active site entrance both contribute to strict substrate specificity. Mutational analysis demonstrated that Asp212 and Asp315 are essential for substrate recognition, and the D212A/D315A LysOX prefers aromatic amino acids. Furthermore, the structural basis of the substrate specificity change has also been revealed by the structural analysis of the D212A/D315A LysOX and its substrate complexes. No potential conflict of interest relevant to this article was reported.

BMC Acta Medica Okayama 1471-2466 21 1 2021 The effects of inhaling hydrogen gas on macrophage polarization, fibrosis, and lung function in mice with bleomycin-induced lung injury 339 EN Toshiyuki Aokage Department of Emergency, Critical Care and Disaster Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Mizuki Seya Department of Emergency, Critical Care and Disaster Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Takahiro Hirayama Department of Disaster Medicine and Management, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Tsuyoshi Nojima Department of Primary Care and Medical Education, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Masumi Iketani Department of Biological Process of Aging, Tokyo Metropolitan Institute of Gerontology Michiko Ishikawa Department of Emergency, Disaster and Critical Care Medicine, Hyogo College of Medicine Yasuhiro Terasaki Department of Analytic Human Pathology, Nippon Medical School Akihiko Taniguchi Department of Hematology, Oncology, and Respiratory Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Nobuaki Miyahara Department of Medical Technology, Okayama University Graduate School of Health Sciences Atsunori Nakao Department of Emergency, Critical Care and Disaster Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Ikuroh Ohsawa Department of Biological Process of Aging, Tokyo Metropolitan Institute of Gerontology Hiromichi Naito Department of Emergency, Critical Care and Disaster Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Background : Acute respiratory distress syndrome, which is caused by acute lung injury, is a destructive respiratory disorder caused by a systemic inflammatory response. Persistent inflammation results in irreversible alveolar fibrosis. Because hydrogen gas possesses anti-inflammatory properties, we hypothesized that daily repeated inhalation of hydrogen gas could suppress persistent lung inflammation by inducing functional changes in macrophages, and consequently inhibit lung fibrosis during late-phase lung injury. <br> Methods : To test this hypothesis, lung injury was induced in mice by intratracheal administration of bleomycin (1.0 mg/kg). Mice were exposed to control gas (air) or hydrogen (3.2% in air) for 6 h every day for 7 or 21 days. Respiratory physiology, tissue pathology, markers of inflammation, and macrophage phenotypes were examined. <br> Results : Mice with bleomycin-induced lung injury that received daily hydrogen therapy for 21 days (BH group) exhibited higher static compliance (0.056 mL/cmH(2)O, 95% CI 0.047-0.064) than mice with bleomycin-induced lung injury exposed only to air (BA group; 0.042 mL/cmH(2)O, 95% CI 0.031-0.053, p = 0.02) and lower static elastance (BH 18.8 cmH(2)O/mL, [95% CI 15.4-22.2] vs. BA 26.7 cmH(2)O/mL [95% CI 19.6-33.8], p = 0.02). When the mRNA levels of pro-inflammatory cytokines were examined 7 days after bleomycin administration, interleukin (IL)-6, IL-4 and IL-13 were significantly lower in the BH group than in the BA group. There were significantly fewer M2-biased macrophages in the alveolar interstitium of the BH group than in the BA group (3.1% [95% CI 1.6-4.5%] vs. 1.1% [95% CI 0.3-1.8%], p = 0.008). <br> Conclusions The results suggest that hydrogen inhalation inhibits the deterioration of respiratory physiological function and alveolar fibrosis in this model of lung injury. No potential conflict of interest relevant to this article was reported.

Wiley Acta Medica Okayama 1467-7644 2021 Regulation of germination by targeted mutagenesis of grain dormancy genes in barley 1 10 EN Hiroshi Hisano Institute of Plant Science and Resources, Okayama University Robert E. Hoffie Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben Fumitaka Abe Institute of Crop Science, NARO Hiromi Munemori Institute of Plant Science and Resources, Okayama University Takakazu Matsuura Institute of Plant Science and Resources, Okayama University Masaki Endo Institute of Agrobiological Sciences, NARO Masafumi Mikami Institute of Agrobiological Sciences, NARO Shingo Nakamura Institute of Crop Science, NARO Jochen Kumlehn Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben Kazuhiro Sato Institute of Plant Science and Resources, Okayama University High humidity during harvest season often causes pre-harvest sprouting in barley (Hordeum vulgare). Prolonged grain dormancy prevents pre-harvest sprouting; however, extended dormancy can interfere with malt production and uniform germination upon sowing. In this study, we used Cas9-induced targeted mutagenesis to create single and double mutants in QTL FOR SEED DORMANCY 1 (Qsd1) and Qsd2 in the same genetic background. We performed germination assays in independent qsd1 and qsd2 single mutants, as well as in two double mutants, which revealed a strong repression of germination in the mutants. These results demonstrated that normal early grain germination requires both Qsd1 and Qsd2 function. However, germination of qsd1 was promoted by treatment with 3% hydrogen peroxide, supporting the notion that the mutants exhibit delayed germination. Likewise, exposure to cold temperatures largely alleviated the block of germination in the single and double mutants. Notably, qsd1 mutants partially suppress the long dormancy phenotype of qsd2, while qsd2 mutant grains failed to germinate in the light, but not in the dark. Consistent with the delay in germination, abscisic acid accumulated in all mutants relative to the wild type, but abscisic acid levels cannot maintain long-term dormancy and only delay germination. Elucidation of mutant allele interactions, such as those shown in this study, are important for fine-tuning traits that will lead to the design of grain dormancy through combinations of mutant alleles. Thus, these mutants will provide the necessary germplasm to study grain dormancy and germination in barley. No potential conflict of interest relevant to this article was reported.

Elsevier BV Acta Medica Okayama 0006-291X 566 2021 Role of the TRPM4 channel in mitochondrial function, calcium release, and ROS generation in oxidative stress 190 196 EN Chen Wang Department of Cardiovascular Physiology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Jian Chen Department of Cardiovascular Physiology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Mengxue Wang Department of Cardiovascular Physiology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Keiji Naruse Department of Cardiovascular Physiology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Ken Takahashi Department of Cardiovascular Physiology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Ischemic heart disease is one of the most common causes of death worldwide. Mitochondrial dysfunction, excessive reactive oxygen species (ROS) generation, and calcium (Ca2þ) overload are three key factors leading to myocardial death during ischemia-reperfusion (I/R) injury. Inhibition of TRPM4, a Ca2þ-activated nonselective cation channel, protects the rat heart from I/R injury, but the specific mechanism underlying this effect is unclear. In this study, we investigated the mechanism of cardioprotection against I/R injury via TRPM4 using hydrogen peroxide (H2O2), a major contributor to oxidative stress, as an I/R injury model. We knocked out the TRPM4 gene in the rat cardiomyocyte cell line H9c2 using CRISPR/Cas9. Upon H2O2 treatment, intracellular Ca2þ level and ROS production increased in wild type (WT) cells but not in TRPM4 knockout (TRPM4KO) cells. With this treatment, two indicators of mitochondrial function, mitochondrial membrane potential (DJm) and intracellular ATP levels, decreased inWT but not in TRPM4KO cells. Taken together, these findings suggest that blockade of the TRPM4 channel might protect the myocardium from oxidative stress by maintaining the mitochondrial membrane potential and intracellular ATP levels, possibly through preventing aberrant increases in intracellular Ca2þ and ROS. No potential conflict of interest relevant to this article was reported.

Nature Research Acta Medica Okayama 2399-3669 4 1 2021 Halogen-sodium exchange enables efficient access to organosodium compounds 76 EN Sobi Asako Division of Applied Chemistry, Graduate School of Natural Science and Technology, Okayama University Ikko Takahashi RIKEN Center for Sustainable Resource Science Hirotaka Nakajima Division of Applied Chemistry, Graduate School of Natural Science and Technology, Okayama University Laurean Ilies RIKEN Center for Sustainable Resource Science Kazuhiko Takai Division of Applied Chemistry, Graduate School of Natural Science and Technology, Okayama University With sodium being the most abundant alkali metal on Earth, organosodium compounds are an attractive choice for sustainable chemical synthesis. However, organosodium compounds are rarely used-and are overshadowed by organolithium compounds-because of a lack of convenient and efficient preparation methods. Here we report a halogen-sodium exchange method to prepare a large variety of (hetero)aryl- and alkenylsodium compounds including tri- and tetrasodioarenes, many of them previously inaccessible by other methods. The key discovery is the use of a primary and bulky alkylsodium lacking beta-hydrogens, which retards undesired reactions, such as Wurtz-Fittig coupling and beta-hydrogen elimination, and enables efficient halogen-sodium exchange. The alkylsodium is readily prepared in situ from neopentyl chloride and an easy-to-handle sodium dispersion. We believe that the efficiency, generality, and convenience of the present method will contribute to the widespread use of organosodium in organic synthesis, ultimately contributing to the development of sustainable organic synthesis by rivalling the currently dominant organolithium reagents. Halogen-sodium exchange reactions with neopentyl sodium provides access to a range of aryl and alkenyl organosodium compounds in situ, as an alternative to organolithium reagents. No potential conflict of interest relevant to this article was reported.

Oxford Univ Press Acta Medica Okayama 0449-3060 62 3 2021 Evaluation of the redox state in mouse organs following radon inhalation 390 400 EN Takahiro Kataoka Graduate School of Health Sciences, Okayama University Norie Kanzaki Ningyo-toge Environmental Engineering Center, Japan Atomic Energy Agency Akihiro Sakoda Ningyo-toge Environmental Engineering Center, Japan Atomic Energy Agency Hina Shuto Graduate School of Health Sciences, Okayama University Junki Yano Graduate School of Health Sciences, Okayama University Shota Naoe Graduate School of Health Sciences, Okayama University Hiroshi Tanaka Ningyo-toge Environmental Engineering Center, Japan Atomic Energy Agency Katsumi Hanamoto Graduate School of Health Sciences, Okayama University Hiroaki Terato Advanced Science Research Center, Okayama University Fumihiro Mitsunobu Graduate School ofMedicine Dentistry and Pharmaceutical Sciences, Okayama University Kiyonori Yamaoka Graduate School of Health Sciences, Okayama University Radon inhalation activates antioxidative functions in mouse organs, thereby contributing to inhibition of oxidative stress-induced damage. However, the specific redox state of each organ after radon inhalation has not been reported. Therefore, in this study, we evaluated the redox state of various organs in mice following radon inhalation at concentrations of 2 or 20 kBq/m(3) for 1, 3 or 10 days. Scatter plots were used to evaluate the relationship between antioxidative function and oxidative stress by principal component analysis (PCA) of data from control mice subjected to sham inhalation. The results of principal component (PC) 1 showed that the liver and kidney had high antioxidant capacity; the results of PC2 showed that the brain, pancreas and stomach had low antioxidant capacities and low lipid peroxide (LPO) content, whereas the lungs, heart, small intestine and large intestine had high LPO content but low antioxidant capacities. Furthermore, using the PCA of each obtained cluster, we observed altered correlation coefficients related to glutathione, hydrogen peroxide and LPO for all groups following radon inhalation. Correlation coefficients related to superoxide dismutase in organs with a low antioxidant capacity were also changed. These findings suggested that radon inhalation could alter the redox state in organs; however, its characteristics were dependent on the total antioxidant capacity of the organs as well as the radon concentration and inhalation time. The insights obtained from this study could be useful for developing therapeutic strategies targeting individual organs. No potential conflict of interest relevant to this article was reported.

American Chemical Society (ACS) Acta Medica Okayama 1523-7060 23 8 2021 Electrosynthesis of Phosphacycles via Dehydrogenative C–P Bond Formation Using DABCO as a Mediator 3120 3124 EN Yuji Kurimoto Division of Applied Chemistry, Graduate School of Natural Science and Technology, Okayama University Jun Yamashita Division of Applied Chemistry, Graduate School of Natural Science and Technology, Okayama University Koichi Mitsudo Division of Applied Chemistry, Graduate School of Natural Science and Technology, Okayama University Eisuke Sato Division of Applied Chemistry, Graduate School of Natural Science and Technology, Okayama University Seiji Suga Division of Applied Chemistry, Graduate School of Natural Science and Technology, Okayama University The first electrochemical synthesis of diarylphosphole oxides (DPOs) was achieved under mild conditions. The practical protocol employs commercially available and inexpensive DABCO as a hydrogen atom transfer (HAT) mediator, leading to various DPOs in moderate to good yields. This procedure can also be applied to the synthesis of six-membered phosphacycles, such as phenophosphazine derivatives. Mechanistic studies suggested that the reaction proceeds via an electro-generated phosphinyl radical. No potential conflict of interest relevant to this article was reported.

Elsevier Acta Medica Okayama 25901524 5 2021 Structural basis of enzyme activity regulation by the propeptide of l-lysine α-oxidase precursor from Trichoderma viride 100044 EN Masaki Kitagawa Department of Macromolecular Science, Graduate School of Science, Osaka University Nanako Ito Department of Macromolecular Science, Graduate School of Science, Osaka University Yuya Matsumoto Department of Biofunctional Chemistry, Graduate School of Environmental and Life Science, Okayama University Masaya Saito Department of Biofunctional Chemistry, Graduate School of Environmental and Life Science, Okayama University Takashi Tamura Department of Biofunctional Chemistry, Graduate School of Environmental and Life Science, Okayama University Hitoshi Kusakabe Enzyme Sensor Co., Ltd. Kenji Inagaki Department of Biofunctional Chemistry, Graduate School of Environmental and Life Science, Okayama University Katsumi Imada Department of Macromolecular Science, Graduate School of Science, Osaka University Harmuful proteins are usually synthesized as inactive precursors and are activated by proteolytic processing. l-Amino acid oxidase (LAAO) is a flavoenzyme that catalyzes the oxidative deamination of l-amino acid to produce a 2-oxo acid with ammonia and highly toxic hydrogen peroxide and, therefore, is expressed as a precursor. The LAAO precursor shows significant variation in size and the cleavage pattern for activation. However, the molecular mechanism of how the propeptide suppresses the enzyme activity remains unclear except for deaminating/decarboxylating Pseudomonasl-phenylalanine oxidase (PAO), which has a short N-terminal propeptide composed of 14 residues. Here we show the inactivation mechanism of the l-lysine oxidase (LysOX) precursor (prLysOX), which has a long N-terminal propeptide composed of 77 residues, based on the crystal structure at 1.97 Å resolution. The propeptide of prLysOX indirectly changes the active site structure to inhibit the enzyme activity. prLysOX retains weak enzymatic activity with strict specificity for l-lysine and shows raised activity in acidic conditions. The structures of prLysOX crystals that soaked in a solution with various concentrations of l-lysine have revealed that prLysOX can adopt two conformations; one is the inhibitory form, and the other is very similar to mature LysOX. The propeptide region of the latter form is disordered, and l-lysine is bound to the latter form. These results indicate that prLysOX uses a different strategy from PAO to suppress the enzyme activity and suggest that prLysOX can be activated quickly in response to the environmental change without proteolytic processing. No potential conflict of interest relevant to this article was reported.

Elsevier Acta Medica Okayama 0921-5093 807 2021 Effects of microstructural characteristics on the hydrogen embrittlement characteristics of austenitic, ferritic, and γ–α duplex stainless steels 140851 EN Mitsuhiro Okayasu Graduate School of Natural Science and Technology, Okayama University Takafumi Fujiwara Graduate School of Natural Science and Technology, Okayama University Hydrogen embrittlement (HE) characteristics of γ (AS), α (FS), and γ–α duplex (DS) stainless steels were examined experimentally and numerically. Severe HE occurred in the DS sample, whereas weak HE was detected in the AS and FS samples. This was attributed to the high hydrogen concentrations at the DS-trapping sites. Hydrogen trapping occurred in the low atomic density zones in the boundaries between α and γ phases in DS sample. The chemical bonding between atomic-scale phase boundaries was weakened by hydrogen penetration. This resulted in a crack growth along the DS α/γ phase boundaries. The ductility of DS decreased as the hydrogen content increased, especially when it exceeded 15 ppm. In contrast, the weak HE observed among AS and FS samples was attributed to the small hydrogen levels that infiltrated both samples. Finally, HE mechanism was proposed on the basis of these experimental results. No potential conflict of interest relevant to this article was reported.

International Union of Crystallography Acta Medica Okayama 2056-9890 76 11 2020 Crystal structures of four isomeric hydrogen-bonded co-crystals of 6-methyl­quinoline with 2-chloro-4-nitro­benzoic acid, 2-chloro-5-nitro­benzoic acid, 3-chloro-2-nitro­benzoic acid and 4-chloro-2-nitro­benzoic acid 1701 1707 EN Kazuma Gotoh Department of Chemistry, Faculty of Science, Okayama University Hiroyuki Ishida Department of Chemistry, Faculty of Science, Okayama University The structures of the four isomeric compounds of 6-methyl­quinoline with chloro- and nitro-substituted benzoic acids, C7H4ClNO4·C10H9N, namely, 2-chloro-4-nitro­benzoic acid–6-methyl­quinoline (1/1), (I), 2-chloro-5-nitro­benzoic acid–6-methyl­quinoline (1/1), (II), 3-chloro-2-nitro­benzoic acid–6-methyl­quinoline (1/1), (III), and 4-chloro-2-nitro­benzoic acid–6-methyl­quinoline (1/1), (IV), have been determined at 185–190 K. In each compound, the acid and base mol­ecules are linked by a short hydrogen bond between a carboxyl O atom and an N atom of the base. The O⋯N distances are 2.5452 (12), 2.6569 (13), 2.5640 (17) and 2.514 (2) Å, respectively, for compounds (I)–(IV). In the hydrogen-bonded acid–base units of (I), (III) and (IV), the H atoms are each disordered over two positions with O site:N site occupancies of 0.65 (3):0.35 (3), 0.59 (4):0.41 (4) and 0.48 (5):0.52 (5), respectively, for (I), (III) and (IV). The H atom in the hydrogen-bonded unit of (II) is located at the O-atom site. In all of the crystals of (I)–(IV), π–π inter­actions between the quinoline ring system and the benzene ring of the acid mol­ecule are observed. In addition, a π–π inter­action between the benzene rings of adjacent acid mol­ecules and a C―H⋯O hydrogen bond are observed in the crystal of (I), and C―H⋯O hydrogen bonds and O⋯Cl contacts occur in the crystals of (III) and (IV). These inter­molecular inter­actions connect the acid and base mol­ecules, forming a layer structure parallel to the bc plane in (I), a column along the a-axis direction in (II), a layer parallel to the ab plane in (III) and a three-dimensional network in (IV). Hirshfeld surfaces for the title compounds mapped over dnorm and shape index were generated to visualize the weak inter­molecular inter­actions. No potential conflict of interest relevant to this article was reported.

Elsevier Acta Medica Okayama 2352-4847 6 Suppl. 7 2020 Self-assembly of Ni–Fe layered double hydroxide at room temperature for oxygen evolution reaction 248 254 EN Seong Hyun Kim Department of Materials Science and Engineering, Pusan National University Yoo Sei Park Department of Materials Science and Engineering, Pusan National University Chiho Kim Department of Materials Science and Engineering, Pusan National University Il Yeong Kwon Department of Materials Science and Engineering, Pusan National University Jooyoung Lee Materials Center for Energy Department, Surface Technology Division, Korea Institute of Materials Science, Hyunsoo Jin Department of Mechanical Engineering, Worcester Polytechnic Institute Yoon-Seok Lee Graduate School of Natural Science and Technology, Okayama University Sung Mook Choi Materials Center for Energy Department, Surface Technology Division, Korea Institute of Materials Science Yangdo Kim Department of Materials Science and Engineering, Pusan National University Active and stable electrocatalysts are the key to water electrolysis for hydrogen production. This paper reports a facile direct growth method to synthesize NiFe-layered double hydroxides (LDHs) on nickel foil as an electrocatalyst for the oxygen evolution reaction. The NiFe-LDH is synthesized by a galvanic process at room temperature without any additional energy for synthesis. The synthesized NiFe-LDH is a karst landform with abundant active sites and efficient mass diffusion. The NiFe-LDH with an oxygen defect show excellent electrocatalytic performance for the OER, with a low overpotential (272 mV at 10 mA/cm2), a small Tafel slope (43 mV/dec), and superior durability. Direct growth synthesis provide excellent electrical conductivity as well as strong bonding between the catalyst layer and the substrate. In addition, this synthesis process is simple to apply in the fabrication of a large size electrode and is believed to be applicable to commercialized alkaline water electrolysis. No potential conflict of interest relevant to this article was reported.

Elsevier Acta Medica Okayama 0032-3861 202 2020 Preparation of solution-grown lozenge-shaped poly(p-phenylene terephthalamide) single crystals and their structural stabilization by heat treatment 122672 EN Tetsuya Uchida Graduate School of Natural Science and Technology, Okayama University Yutaro Hara Graduate School of Natural Science and Technology, Okayama University Tomoyasu Takaki Graduate School of Natural Science and Technology, Okayama University In this study, the preparation of poly (p-phenylene terephthalamide) (PPTA) single crystals was examined using crystallization from dilute solutions in concentrated sulfuric acid. Lozenge-shaped PPTA single crystals were successfully prepared using a self-seeding method with a low degree of supercooling, and they consisted of modification I crystals. The a-axis direction of the crystal corresponded to the long diagonal direction of the rhombus, the b-axis direction with the short diagonal direction, and the PPTA molecular chain direction (the c-axis direction) with the crystal's thickness direction. In addition, the PPTA single crystals had a (110) growth plane, where the thickness of each single crystal was approximately equal to the molecular chain length of the PPTA. Upon heat treatment of the PPTA single crystals, the symmetry changed from P1a1 to the more stable P11n. In addition, the heat treatment caused a difference in the density of each symmetric crystal, resulting in crack formation along the b-axis direction, which is the hydrogen-bonding direction. However, the heat treatment did not change the thickness of the PPTA single crystals. Conversely, the isothermal crystallization of the PPTA caused progression in the crystallization only under a high degree of supercooling, thus yielding plate-like PPTA crystals that consisted of modification II crystals. In these plate-like PPTA crystals, the length corresponded to the crystal a-axis direction, and the electron diffraction pattern was broad. Furthermore, the equilibrium dissolution temperature of the PPTA single crystals was discussed. No potential conflict of interest relevant to this article was reported.

Elsevier Acta Medica Okayama 0921-5093 791 2020 The effect of precipitations (NbC and carbide) in Fe–C–Mn-xNb steels on hydrogen embrittlement characteristics 139598 EN Mitsuhiro Okayasu Graduate School of Natural Science and Technology, Okayama University Masaya Sato Graduate School of Natural Science and Technology, Okayama University Daiki Ishida Graduate School of Natural Science and Technology, Okayama University Takehide Senuma Graduate School of Natural Science and Technology, Okayama University Hydrogen embrittlement (HE) characteristics in Fe–C–Mn-xNb steels were examined via various analyses, including electron backscatter diffraction analysis, scanning transmission electron microscopy and three-dimensional atom-probe tomography. For the investigation, the steel samples were prepared with varying Nb contents and heat treatment processes. The material properties of steel samples that were subjected to: (i) water quenching and (ii) quenching and tempering at 170 °C for 20 min, were determined to be nearly similar, although different degrees of HE were detected. After the tempering process, ε-carbide precipitated clearly in the matrix, which could act as a trapping site for hydrogen atoms and lead to improved HE resistance. Moreover, with addition of Nb, niobium base precipitates (e.g., NbC) with a diameter of a few nanometers were obtained in the martensite matrix, which could also function as hydrogen trapping sites. There was slight improvement in the HE resistance with NbC. Hydrogen-assisted failure mechanisms under both static and cyclic loading were observed with intergranular brittle cracking for the water quenched sample, even though the brittle and ductile mix failure mode was detected for the sample after the quenching and tempering process. No potential conflict of interest relevant to this article was reported.

International Union of Crystallography Acta Medica Okayama 2052-2525 7 3 2020 Strong hydrogen bonding in a dense hydrous magnesium silicate discovered by neutron Laue diffraction 370 374 EN Narangoo Purevjav Institute for Planetary Materials, Okayama University Takuo Okuchi Institute for Planetary Materials, Okayama University Christina Hoffman Neutron Scattering Division, Neutron Sciences Directorate, Oak Ridge National Laboratory A large amount of hydrogen circulates inside the Earth, which affects the long-term evolution of the planet. The majority of this hydrogen is stored in deep Earth within the crystal structures of dense minerals that are thermodynamically stable at high pressures and temperatures. To understand the reason for their stability under such extreme conditions, the chemical bonding geometry and cation exchange mechanism for including hydrogen were analyzed in a representative structure of such minerals (i.e. phase E of dense hydrous magnesium silicate) by using time-of-flight single-crystal neutron Laue diffraction. Phase E has a layered structure belonging to the space group R (3) over barm and a very large hydrogen capacity (up to 18% H2O weight fraction). It is stable at pressures of 13-18 GPa and temperatures of up to at least 1573 K. Deuterated high-quality crystals with the chemical formula Mg2.28Si1.32D2.15O6 were synthesized under the relevant high-pressure and high-temperature conditions. The nuclear density distribution obtained by neutron diffraction indicated that the O-D dipoles were directed towards neighboring O2- ions to form strong interlayer hydrogen bonds. This bonding plays a crucial role in stabilizing hydrogen within the mineral structure under such high-pressure and high-temperature conditions. It is considered that cation exchange occurs among Mg2+, D+ and Si4+ within this structure, making the hydrogen capacity flexible. No potential conflict of interest relevant to this article was reported.

American Chemical Society Acta Medica Okayama 15237060 22 6 2020 Palladium-Catalyzed Decarbonylative Alkylation of Acyl Fluorides 2350 2353 EN Liyan Fu Graduate School of Natural Science and Technology, Okayama University Qiang Chen Graduate School of Natural Science and Technology, Okayama University Zhenhua Wang Graduate School of Natural Science and Technology, Okayama University Yasushi Nishihara Research Institute for Interdisciplinary Science, Okayama University Palladium-catalyzed decarbonylative alkylation reactions of acyl fluorides have been developed using alkylboranes having β-hydrogens. A wide range of functional groups were well tolerated, even at the high temperature required for decarbonylation. This protocol provides a diverse C(sp2)–C(sp3) bond formation via a highly efficient decarbonylative process. The hemilabile bidentate ligand DPPE plays a crucial role for retardation of the undesired β-hydride elimination. No potential conflict of interest relevant to this article was reported.

Elsevier Acta Medica Okayama 09215093 790 2020 Microstructure-dependent hydrogen diffusion and trapping in high-tensile steel 139418 EN Mitsuhiro Okayasu Graduate School of Natural Science and Technology, Okayama University Jun Motojima Graduate School of Natural Science and Technology, Okayama University In this work, the hydrogen embrittlement (HE) characteristics of high-tensile steel sheets with different microstructural characteristics were investigated. The sheets were fabricated via cold rolling (CR), water quenching (WQ), baking hardening (BH), and low-temperature annealing (LT), and their HE characteristics were clarified by examining the relationships between the microstructural characteristics and the severity of HE. Severe HE occurred in the WQ sample with hydrogen trapping at the boundaries of the retained austenite phases, resulting in intergranular and cleavage-like brittle failure. A reduction in HE was realized after the BH and LT processes. In these cases, hydrogen trapping was divided between the ε-carbide in the lattice spacings and at the boundaries of retained austenite, resulting in a mixed ductile/brittle failure mode. The extent of HE in the CR sample was similar to those in the BH and LT samples. However, the trapping sites were different; hydrogen trapping in the CR sample occurred in the slip band and around dislocations, resulting in delamination-like brittle failure on the slip planes. The extent of HE was also affected by the strain rate. More severe HE occurred in both the WQ and BH samples loaded slowly at 0.01 mm min−1 compared to the samples loaded 1.0 mm min−1 (i.e., intergranular failure). In this case, HE was affected by the large amount of hydrogen atoms trapped at the boundaries of the retained austenite phases. The hydrogen atoms in the lattice structure and ε-carbide migrated to the boundaries via dislocation movement. The extent of deterioration in tensile strength was two times higher in the samples loaded at the higher speed of 1.0 mm min−1 compared to those loaded at 0.01 mm min−1. Finally, the hydrogen trapping and failure mechanisms on the nano and atomic scales were discussed based on the results of the microstructural analyses. No potential conflict of interest relevant to this article was reported.

Elsevier Acta Medica Okayama 02775387 179 2020 A specific formation of an iridium(III) hydrido complex bearing 8-(diphenylphosphino)quinoline 114401 EN Keita Ariyoshi Department of Chemistry, Faculty of Science, Okayama University Mai Kotera Department of Chemistry, Faculty of Science, Osaka University Atsushi Namioka Department of Chemistry, Faculty of Science, Okayama University Takayoshi Suzuki Department of Chemistry, Faculty of Science, Okayama University A reaction of [Cp*IrCl(Ph2Pqn)]PF6 {Cp* = η5-pentamethylcyclopentadienyl; Ph2Pqn = 8-(diphenylphosphino)quinoline} and Ag(CF3SO3) in methanol afforded orange crystals of the corresponding hydrido complex, [Cp*IrH(Ph2Pqn)]PF6, which was identified by 1H, 31P{1H} NMR and IR spectroscopy as well as X-ray structural analysis. The reactions in deuterated solvents indicated that formation of the hydrido complex proceeded via β-hydrogen elimination of the coordinated methanol molecule. It was also revealed that the hydrido formation was specific for the complex bearing Ph2Pqn ancillary ligand; the analogous complex with 1,2-bis(diphenylphosphino)benzene (diphos) or 1,10-phenanthroline (phen) did not give the corresponding hydrido complex by a similar reaction with Ag+ in methanol. In order to elucidate the reason for the different reactivity among these complexes, the crystal structures of the precursor chlorido complexes, [Cp*IrCl(Ph2Pqn)]PF6, [Cp*IrCl(diphos)]PF6 and [Cp*IrCl(phen)]PF6, as well as an acetonitrile complex of [Cp*Ir(Ph2Pqn)(CH3CN)](PF6)2, were also determined by X-ray analysis. The resulting structural information suggested that a specific formation of the hydrido complex with Ph2Pqn could be originated from the facile formation of the corresponding methanol complex and the hemilabile nature of ancillary Ph2Pqn ligand, which induced the reactivity of the coordinated methanol toward β-hydrogen elimination. No potential conflict of interest relevant to this article was reported.

Royal Society of Chemistry Acta Medica Okayama 14668033 22 3 2019 Transition-metal(ii) complexes with a tripodal hexadentate ligand, 1,1,1-tris[2-aza-3-(imidazol-4-yl)prop-2-enyl]ethane, exhibiting incomplete total or absolute spontaneous resolution 458 466 EN Misaki Matsushima Graduate School of Natural Science and Technology, Okayama University Koki Wada Graduate School of Natural Science and Technology, Okayama University Kazuma Takahara Graduate School of Natural Science and Technology, Okayama University Yukinari Sunatsuki Graduate School of Natural Science and Technology, Okayama University Takayoshi Suzuki Graduate School of Natural Science and Technology, Okayama University Crystal structures and crystallisation behaviours of a series of first-row transition-metal(II) complexes bearing 1,1,1-tris[2-aza-3-(imidazol-4-yl)prop-2-enyl]ethane (H3L), [MII(H3L)]Cl(ClO4) (M = Mn, Fe, Co, Ni and Zn) were examined. These compounds crystallise in an orthorhombic crystal system with a non-enantiogenic (Sohncke) space group P212121, resulting in spontaneous resolution of the chiral complex cations. Hydrogen bonds between the imidazole N–H atoms in the tripodal ligand and chloride anions give enantiomorphic crystals with a homochiral three-dimensional network structure. In order to verify the spontaneous resolution of these compounds, solid-state circular dichroism spectra of the resulting single crystals were measured (KBr disk method). Unexpectedly, the observed spectra indicated that imbalanced formation of the enantiomorphic crystals (i.e., left-handed Λ-form vs. right-handed Δ-form complex cations) in all cases. Moreover, in the cases of NiII and ZnII compounds, predominant enantiomorphic crystals formed by spontaneous resolution were always the same (in at least ten of our recrystallisation experiments). These observations suggest that there is a certain (but as yet unknown) factor that affects the predominant deposition of either enantiomorphic crystal when spontaneous resolution takes place from a solution of a racemic mixture in which rapid racemisation occurs. No potential conflict of interest relevant to this article was reported.

American Chemical Society Acta Medica Okayama 15237060 21 17 2019 Rhenium-Catalyzed Cyclization via 1,2-Iodine and 1,5-Hydrogen Migration for the Synthesis of 2-Iodo-1H-indenes 6756 6760 EN Masahito Murai Graduate School of Natural Science and Technology, Okayama University Kazuhiko Takai Graduate School of Natural Science and Technology, Okayama University A rhenium complex catalyzed the formation of 2-iodo-1H-indene derivatives through iodine and hydrogen migration of 3-iodopropargyl ethers. The reaction proceeded via generation of 1-iodoalkenylrhenium carbene species by sequential 1,2-iodine and 1,5-hydrogen shifts with readily available precursors under neutral conditions. The reaction mechanism and the reactivity of the generated alkenylcarbene species were also investigated. No potential conflict of interest relevant to this article was reported.

American Chemical Society Acta Medica Okayama 0022-3263 85 2 2019 Formal Total Synthesis of Manzacidin B via Sequential Diastereodivergent Henry Reaction 798 805 EN Yuya Araki Division of Applied Chemistry, Graduate School of Natural Science and Technology, Okayama University Natsumi Miyoshi Division of Applied Chemistry, Graduate School of Natural Science and Technology, Okayama University Kazuki Morimoto Division of Applied Chemistry, Graduate School of Natural Science and Technology, Okayama University Takayuki Kudoh Division of Applied Chemistry, Graduate School of Natural Science and Technology, Okayama University Haruki Mizoguchi Division of Applied Chemistry, Graduate School of Natural Science and Technology, Okayama University Akira Sakakura Division of Applied Chemistry, Graduate School of Natural Science and Technology, Okayama University A formal total synthesis of manzacidin B is described. beta,beta-Disubstituted gamma-hydroxy-beta-aminoalcohol, the key structure of manzacidin B, is stereoselectively constructed via sequential Henry reactions. By taking advantage of noncovalent interactions, such as intramolecular hydrogen bonding and chelation, we could diastereodivergently control the stereoselectivity of the Henry reaction. No potential conflict of interest relevant to this article was reported.

International Union of Crystallography Acta Medica Okayama 2056-9890 75 2019 Crystal structure of 4-chloro-2-nitrobenzoic acid with 4-hydroxyquinoline: a disordered structure over two states of 4-chloro-2-nitrobenzoic acid-quinolin-4(1H)-one (1/1) and 4-hydroxyquinolinium 4-chloro-2-nitrobenzoate 1853 EN Kazuma Gotoh Department of Chemistry, Faculty of Science, Okayama University Hiroyuki Ishida Department of Chemistry, Faculty of Science, Okayama University The title compound, C9H7.5NO center dot C7H3.5ClNO4, was analysed as a disordered structure over two states, viz. co-crystal and salt, accompanied by a keto-enol tautomerization in the base molecule. The co-crystal is 4-chloro-2-nitrobenzoic acid-quinolin-4(1H)-one (1/1), C7H4ClNO4 center dot C9H7NO, and the salt is 4-hydroxy-quinolinium 4-chloro-2-nitrobenzoate, C9H8NO+center dot C7H3ClNO4. In the compound, the acid and base molecules are held together by a short hydrogen bond [O center dot center dot center dot O = 2.4393 (15) angstrom], in which the H atom is disordered over two positions with equal occupancies. In the crystal, the hydrogen-bonded acid-base units are linked by N-H center dot center dot center dot O and C-H center dot center dot center dot O hydrogen bonds, forming a tape structure along the a-axis direction. The tapes are stacked into a layer parallel to the ab plane via pi-pi interactions [centroid-centroid distances = 3.5504 (8)-3.9010 (11) angstrom]. The layers are further linked by another C-H center dot center dot center dot O hydrogen bond, forming a three-dimensional network. Hirshfeld surfaces for the title compound mapped over shape-index and d orm were generated to visualize the intermolecular interactions. No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 0386-2208 95 4 2019 Hypervelocity collision and water-rock interaction in space preserved in the Chelyabinsk ordinary chondrite 165 177 EN Eizo Nakamura The Pheasant Memorial Laboratory, Institute for Planetary Materials, Okayama University Tak Kunihiro The Pheasant Memorial Laboratory, Institute for Planetary Materials, Okayama University Tsutomu Ota The Pheasant Memorial Laboratory, Institute for Planetary Materials, Okayama University Chie Sakaguchi The Pheasant Memorial Laboratory for Geochemistry and Cosmochemistry, Institute for Planetary Materials, Okayama University Ryoji Tanaka The Pheasant Memorial Laboratory for Geochemistry and Cosmochemistry, Institute for Planetary Materials, Okayama University Hiroshi Kitagawa Okayama Univ, Inst Planetary Mat, Pheast Mem Lab Geochem & Cosmochem Katsura Kobayashi The Pheasant Memorial Laboratory for Geochemistry and Cosmochemistry, Institute for Planetary Materials, Okayama University Masahiro Yamanaka The Pheasant Memorial Laboratory for Geochemistry and Cosmochemistry, Institute for Planetary Materials, Okayama University Yuri Shimaki The Pheasant Memorial Laboratory for Geochemistry and Cosmochemistry, Institute for Planetary Materials, Okayama University Gray E. Bebout The Pheasant Memorial Laboratory for Geochemistry and Cosmochemistry, Institute for Planetary Materials, Okayama University Hitoshi Miura Graduate School of Natural Sciences, Nagoya City University Tetsuo Yamamoto Institute of Low Temperature Science, Hokkaido University Vladimir Malkovets The Pheasant Memorial Laboratory for Geochemistry and Cosmochemistry, Institute for Planetary Materials, Okayama University Victor Grokhovsky Institute of Physics and Technology, Ural Federal University Olga Koroleva Institute of Mineralogy, Ural Branch of the Russian Academy of Sciences South-Ural State University Konstantin Litasov V.S. Sobolev Institute of Geology and Mineralogy, Siberian Branch of the Russian Academy of Sciences A comprehensive geochemical study of the Chelyabinsk meteorite reveals further details regarding its history of impact-related fragmentation and melting, and later aqueous alteration, during its transit toward Earth. We support an similar to 30 Ma age obtained by Ar-Ar method (Beard et al., 2014) for the impact-related melting, based on Rb-Sr isotope analyses of a melt domain. An irregularly shaped olivine with a distinct 0 isotope composition in a melt domain appears to be a fragment of a silicate-rich impactor. Hydrogen and Li concentrations and isotopic compositions, textures of Fe oxyhydroxides, and the presence of organic materials located in fractures, are together consistent with aqueous alteration, and this alteration could have pre-dated interaction with the Earth's atmosphere. As one model, we suggest that hypervelocity capture of the impact-related debris by a comet nucleus could have led to shock-wave-induced supercritical aqueous fluids dissolving the silicate, metallic, and organic matter, with later ice sublimation yielding a rocky rubble pile sampled by the meteorite. No potential conflict of interest relevant to this article was reported.

岡山大学農学部 Acta Medica Okayama 2186-7755 109 2020 Marinomonas mediterranea由来キノン含有新規グリシンオキシダーゼの大腸菌発現系の確立と性質検討 1 6 EN Yuki Kajiyama Graduate School of Environmental and Life Science, Okayama University Satsuki Mizobata Graduate School of Environmental and Life Science, Okayama University Shusaku Akaji Graduate School of Environmental and Life Science, Okayama University Michiko Nemoto Graduate School of Environmental and Life Science, Okayama University Takashi Tamura Graduate School of Environmental and Life Science, Okayama University Kenji Inagaki Graduate School of Environmental and Life Science, Okayama University 　Novel glycine oxidase (GlyOX) from Marinomonas mediterranea depends on cysteine tryptophilquinone (CTQ) and catalyzes the oxidative deamination of glycine to produce a glyoxylate, ammonia, and hydrogen peroxide. M. mediterranea GlyOX genes (goxA and goxB) were cloned and recombinant GlyOX was heterologously expressed by E. coli. The purification of recombinant GlyOX was carried out by metal affinity and DEAE-Toyopearl 650M column chromatographies. M. mediterranea GlyOX was homotetramic with a molecular mass of 76kDa and showed optimum activity around 30°C and at pH 5.0, and stability below 50°C and between pH 5.0 to 9.0. M. mediterranea GlyOX shows a strict substrate specificity toward glycine, and the Michaelis constant for glycine was 0.5mM. M. mediterranea GlyOX could determine the quantity of glycine in human serum and human blood plasma with high sensitivity. This study revealed the catalytic and structural properties of M. mediterranea GlyOX with high substrate specificity. No potential conflict of interest relevant to this article was reported.

Nature Publishing Group Acta Medica Okayama 2045-2322 9 2019 Long-term stabilization of hydrogen peroxide by poly(vinyl alcohol) on paper-based analytical devices 12951 EN Tuchpongpuch Boonpoempoon Department of Chemistry, Faculty of Science and Technology, Suan Sunandha Rajabhat University Wanida Wonsawat Department of Chemistry, Faculty of Science and Technology, Suan Sunandha Rajabhat University Takashi Kaneta Department of Chemistry, Graduate School of Natural Science and Technology, Okayama University Stabilizing reagents that can be deposited onto paper is an important issue for researchers who depend on paper-based analytical devices (PADs), because long-term stability of the devices is essential in pointof-care testing. Here, we found that poly(vinyl alcohol) (PVA) would stabilize hydrogen peroxide placed on a paper substrate following exposure to air. Horseradish peroxidase was employed as a sample in colorimetric measurements of PADs after hydrogen peroxide and 3,3',5,5'-tetramethylbenzidine were deposited as substrates in an enzymatic reaction. The addition of PVA to hydrogen peroxide significantly suppressed its degradation. Concentrations of PVA that ranged from 0.5 to 2%, increased the duration of the stability of hydrogen peroxide, and the results for a PVA concentration of 1% approximated those of 2% PVA. Storage of the PADs at 4 degrees C in a refrigerator extended the stability of the hydrogen peroxide containing 2% PVA by as much as 30 days. The stability of hydrogen peroxide without PVA was degraded after one day under room temperature. No potential conflict of interest relevant to this article was reported.

Mineralogical Society of America Acta Medica Okayama 0003-004X 103 8 2018 The effects of ferromagnetism and interstitial hydrogen on the equation of states of hcp and dhcp FeHx: Implications for the Earth's inner core age 1271 1281 EN Hitoshi Gomi Institute for Planetary Materials, Okayama University Yingwei Fei Geophysical Laboratory, Carnegie Institution of Washington Takashi Yoshino Institute for Planetary Materials, Okayama University Hydrogen has been considered as an important candidate of light elements in the Earth's core. Because iron hydrides are unquenchable, hydrogen content is usually estimated from in situ X-ray diffraction measurements that assume the following linear relation: x = (V-FeHx - V-Fe)/Delta V-H, where x is the hydrogen content, Delta V-H is the volume expansion caused by unit concentration of hydrogen, and V-FeHx and V-Fe are volumes of FeHx and pure iron, respectively. To verify the linear relationship, we computed the equation of states of hexagonal iron with interstitial hydrogen by using the Korringa-Kohn-Rostoker method with the coherent potential approximation (KKR-CPA). The results indicate a discontinuous volume change at the magnetic transition and almost no compositional (x) dependence in the ferromagnetic phase at 20 GPa, whereas the linearity is confirmed in the non-magnetic phase. In addition to their effect on the density-composition relationship in the Fe-FeHx system, which is important for estimating the hydrogen incorporation in planetary cores, the magnetism and interstitial hydrogen also affect the electrical resistivity of FeHx. The thermal conductivity can be calculated from the electrical resistivity by using the Wiedemann-Franz law, which is a critical parameter for modeling the thermal evolution of the Earth. Assuming an Fe1-ySiyHx ternary outer core model (0.0 <= x <= 0.7), we calculated the thermal conductivity and the age of the inner core. The resultant thermal conductivity is similar to 100 W/m/K and the maximum inner core age ranges from 0.49 to 0.86 Gyr. No potential conflict of interest relevant to this article was reported.

INT UNION CRYSTALLOGRAPHY Acta Medica Okayama 2056-9890 75 10 2019 Crystal structures of 3-chloro-2-nitrobenzoic acid with quinoline derivatives: 3-chloro-2-nitrobenzoic acid-5-mtroqumohne (1/1), 3-chioro-2-nitrobenzoic acid-6-mtroquinoline (1/1) and 8-hydroxyquinolinium 3-chioro-2-nitrobenzoate 1552 1557 EN Kazuma Gotoh Department of Chemistry, Faculty of Science, Okayama University Hiroyuki Ishida Department of Chemistry, Faculty of Science, Okayama University The structures of three compounds of 3-chloro-2-nitrobenzoic acid with 5-nitroquinoline, (I), 6-nitroquinoline, (II), and 8-hydroxyquinoline, (III), have been determined at 190 K. In each of the two isomeric compounds, (I) and (II), C7H4ClNO4 center dot C9H6N2O2, the acid and base molecules are held together by O - H center dot center dot center dot N and C - H center dot center dot center dot O hydrogen bonds. In compound (III), C9H8NO+center dot-C7H3ClNO4-, an acid-base interaction involving H-atom transfer occurs and the H atom is located at the N site of the base molecule. In the crystal of (I), the hydrogen-bonded acid-base units are linked by C -H center dot center dot center dot O hydrogen bonds, forming a tape structure along the b-axis direction. Adjacent tapes, which are related by a twofold rotation axis, are linked by a third C - H center dot center dot center dot O hydrogen bond, forming wide ribbons parallel to the ((1) over bar 03) plane. These ribbons are stacked via pi-pi interactions between the quinoline ring systems [centroid-centroid distances = 3.4935 (5)-3.7721 (6) angstrom], forming layers parallel to the ab plane. In the crystal of (II), the hydrogen-bonded acid-base units are also linked into a tape structure along the b-axis direction via C -H center dot center dot center dot O hydrogen bonds. Inversion-related tapes are linked by further C-H center dot center dot center dot O hydrogen bonds to form wide ribbons parallel to the ((3) over bar 08) plane. The ribbons are linked by weak pi-pi interactions [centroid-centroid distances = 3.8016 (8)-3.9247 (9) angstrom], forming a three-dimensional structure. In the crystal of (III), the cations and the anions are alternately linked via N - H center dot center dot center dot O and O - H center dot center dot center dot-O hydrogen bonds, forming a 2(1) helix running along the b-axis direction. The cations and the anions are further stacked alternately in columns along the a-axis direction via pi-pi interactions [centroid-centroid distances = 3.8016 (8)-3.9247 (9) angstrom], and the molecular chains are linked into layers parallel to the ab plane through these interactions. No potential conflict of interest relevant to this article was reported.

Royal Society of Chemistry Acta Medica Okayama 20462069 3 31 2013 Effects of hydrophobic hydration on polymer chains immersed in supercooled water 12743 12750 EN Tomonari Sumi Department of Chemistry, Okayama University Hideo Sekino Department of Computer Science and Engineering, Toyohashi University of Technology A multiscale simulation of a hydrophobic polymer chain immersed in water including the supercooled region is presented. Solvent effects on the polymer conformation were taken into account via liquid–state density functional theory in which a free-energy functional model was constructed using a density response function of bulk water, determined from a molecular dynamics (MD) simulation. This approach overcomes sampling problems in simulations of high-viscosity polymer solutions in the deeply supercooled region. Isobars determined from the MD simulations of 4000 water molecules suggest a liquid–liquid transition in the deeply supercooled region. The multiscale simulation reveals that a hydrophobic polymer chain exhibits swelling upon cooling along isobars below a hypothesized second critical pressure; no remarkable swelling is observed at higher pressures. These observations agree with the behavior of a polymer chain in a Jagla solvent model that qualitatively reproduces the thermodynamics and dynamics of liquid water. A theoretical analysis of the results obtained from the multiscale simulation show that a decrease in entropy due to the swelling arises from the formation of a tetrahedral hydrogen bond network in the hydration shell. No potential conflict of interest relevant to this article was reported.

American Institute of Physics Acta Medica Okayama 00219606 150 4 2019 Phase diagram of ice polymorphs under negative pressure considering the limits of mechanical stability 041102 EN Takahiro Matsui Graduate School of Natural Science and Technology, Okayama University Takuma Yagasaki Research Institute for Interdisciplinary Science, Okayama University Masakazu Matsumoto Research Institute for Interdisciplinary Science, Okayama University Hideki Tanaka Research Institute for Interdisciplinary Science, Okayama University Thermodynamic and mechanical stabilities of various ultralow-density ices are examined using computer simulations to construct the phase diagram of ice under negative pressure. Some ultralow-density ices, which were predicted to be thermodynamically metastable under negative pressures on the basis of the quasi-harmonic approximation, can exist only in a narrow pressure range at very low temperatures because they are mechanically fragile due to the large distortion in the hydrogen bonding network. By contrast, relatively dense ices such as ice Ih and ice XVI withstand large negative pressure. Consequently, various ices appear one after another in the phase diagram. The phase diagram of ice under negative pressure exhibits a different complexity from that of positive pressure because of the mechanical instability. No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 2018 Experimental Investigation and CFD Simulation of Mixture Formation and Combustion in Hydrogen Direct Injection Spark-Ignition Engine EN Graduate School of Natural Science and Technology, Okayama University No potential conflict of interest relevant to this article was reported.

Okayama University Medical School Acta Medica Okayama 0386-300X 72 2 2018 Portal Venous Gas Following Ingestion of Hydrogen Peroxide Successfully Treated with Hyperbaric Oxygen Therapy 181 183 EN Chika Tsuboi Emergency Center and Critical Care Unit, Tsuyama Chuo Hospital Hiromichi Naito Department of Emergency and Critical Care Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Shingo Hagioka Emergency Center and Critical Care Unit, Tsuyama Chuo Hospital Hiroaki Hanafusa Emergency Center and Critical Care Unit, Tsuyama Chuo Hospital Takahiro Hirayama Department of Emergency and Critical Care Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Yoshinori Kosaki Department of Emergency and Critical Care Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Atsuyoshi Iida Department of Emergency and Critical Care Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Tetsuya Yumoto Department of Emergency and Critical Care Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Kohei Tsukahara Department of Emergency and Critical Care Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Naoki Morimoto Emergency Center and Critical Care Unit, Tsuyama Chuo Hospital Atsunori Nakao Department of Emergency and Critical Care Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Case Report 10.18926/AMO/55859 The primary toxicity of hydrogen peroxide results from its interaction with catalase, which liberates water and oxygen. We report the case of a 14-year-old Japanese girl with portal venous gas that was caused by oxygen liberated from intentionally ingested hydrogen peroxide. Although she had a past history of atrial septal defect, recovery without cardiac or neurological sequelae was achieved using hyperbaric oxygen therapy. Emergency physicians must be aware of the danger of liberated oxygen due to hydrogen peroxide ingestion. No potential conflict of interest relevant to this article was reported.

American Physical Society Acta Medica Okayama 2469-9926 96 6 2017 Frequency dependence of coherently amplified two-photon emission from hydrogen molecules 063827 EN Hideaki Hara Research Institute for Interdisciplinary Science, Okayama University Yuki Miyamoto Research Institute for Interdisciplinary Science, Okayama University Takahiro Hiraki Research Institute for Interdisciplinary Science, Okayama University Takahiko Masuda Research Institute for Interdisciplinary Science, Okayama University Noboru Sasao Research Institute for Interdisciplinary Science, Okayama University Satoshi Uetake Research Institute for Interdisciplinary Science, Okayama University Akihiro Yoshimi Research Institute for Interdisciplinary Science, Okayama University Koji Yoshimura Research Institute for Interdisciplinary Science, Okayama University Motohiko Yoshimura Research Institute for Interdisciplinary Science, Okayama University We investigate how the efficiency of coherently amplified two-photon emission depends on the frequency of one of the two emitted photons, namely the signal photon. This is done over the wavelength range of 5.048-10.21 mu m by using the vibrational transition of parahydrogen. The efficiency increases with the frequency of the signal photon. Considering experimental errors, our results are consistent with the theoretical prediction for the present experimental conditions. This study is an experimental demonstration of the frequency dependence of coherently amplified two-photon emission, and also presents its potential as a light source. No potential conflict of interest relevant to this article was reported.

Springer Acta Medica Okayama 1438-4957 18 4 2016 Gasification and reforming of biomass and waste samples by means of a novel catalyst 646 654 EN Katsuya Kawamoto Environmental Management CenterOkayama University Baowang Lu Hydrogen Isotope Research Center, Organization for Promotion of ResearchUniversity of Toyama This study conducted gasification and catalytic reforming experiments with the expectation of obtaining new advantages on energy recovery and aimed for the development of an effective catalyst. Initially, the use of thermal gasification technology for waste treatment in line with waste-to-energy strategies was reviewed. Technological systems which have gasification were classified and their current status was discussed. Then, the results of gasification and reforming experiments showed that product gas with 50 % H2 or more was obtained using a Ni catalyst on a mesoporous silica–based SBA-15 support (NiO/SBA-15), which we newly developed. Experiments using wood feedstock revealed that H2 production by the catalyst was better when the NiO content was 20 % (W/W) or more than when another catalyst or the Ni catalyst with a lower Ni loading was used. Tar formation as a by-product was also well controlled by the catalyst, and use of a catalyst with 40 % NiO reduced the tar concentration to less than 0.2 g/ m3NmN3 . Experiments using a mixed feedstock of wood and RPF resulted in an increase in hydrocarbon concentration because of insufficient reforming. This finding suggests that future work is required to find a better solution to wood and RPF co-gasification. No potential conflict of interest relevant to this article was reported.

American Society for Biochemistry and Molecular Biology Acta Medica Okayama 0021-9258 292 23 2017 Crystal structure and redox properties of a novel cyanobacterial heme protein with a His/Cys heme axial ligation and a Per-Arnt-Sim (PAS)-like domain 9599 9612 EN Taiki Motomura the Research Institute for Interdisciplinary Science and Graduate School of Natural Science and Technology, Okayama University Michihiro Suga the Research Institute for Interdisciplinary Science and Graduate School of Natural Science and Technology, Okayama University Rainer Hienerwadel the Laboratoire de Génétique et Biophysique des Plantes, UMR 7265, CNRS-CEA-Aix-Marseille Université, Faculté des Sciences de Luminy Akiko Nakagawa the Research Institute for Interdisciplinary Science and Graduate School of Natural Science and Technology, Okayama University Thanh-Lan Lai iBiTec-S Wolfgang Nitschke the Laboratoire de Bioénergétique et Ingénierie des Protéines Takahiro Kuma the Research Institute for Interdisciplinary Science and Graduate School of Natural Science and Technology, Okayama University Miwa Sugiura the Proteo-Science Research Center, Ehime University Alain Boussac iBiTec-S Jian-Ren Shen the Research Institute for Interdisciplinary Science and Graduate School of Natural Science and Technology, Okayama University Photosystem II catalyzes light-induced water oxidation leading to the generation of dioxygen indispensable for sustaining aerobic life on Earth. The Photosystem II reaction center is composed of D1 and D2 proteins encoded by psbA and psbD genes, respectively. In cyanobacteria, different psbA genes are present in the genome. The thermophilic cyanobacterium Thermosynechococcus elongatus contains three psbA genes: psbA1, psbA2, and psbA3, and a new c-type heme protein, Tll0287, was found to be expressed in a strain expressing the psbA2 gene only, but the structure and function of Tll0287 are unknown. Here we solved the crystal structure of Tll0287 at a 2.0 Å resolution. The overall structure of Tll0287 was found to be similar to some kinases and sensor proteins with a Per-Arnt-Sim-like domain rather than to other c-type cytochromes. The fifth and sixth axial ligands for the heme were Cys and His, instead of the His/Met or His/His ligand pairs observed for most of the c-type hemes. The redox potential, E½, of Tll0287 was -255 ± 20 mV versus normal hydrogen electrode at pH values above 7.5. Below this pH value, the E½ increased by ≈57 mV/pH unit at 15 °C, suggesting the involvement of a protonatable group with a pKred = 7.2 ± 0.3. Possible functions of Tll0287 as a redox sensor under microaerobic conditions or a cytochrome subunit of an H2S-oxidizing system are discussed in view of the environmental conditions in which psbA2 is expressed, as well as phylogenetic analysis, structural, and sequence homologies. No potential conflict of interest relevant to this article was reported.

岡山医学会 Acta Medica Okayama 0030-1558 129 1 2017 水素水は怪しい水でしょうか？ 9 15 EN Atsunori Nakao Department of Emergency and Critical Care Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences No potential conflict of interest relevant to this article was reported.

Okayama University Medical School Acta Medica Okayama 0386-300X 70 5 2016 The Clinical Application of Hydrogen as a Medical Treatment 331 337 EN Atsuyoshi Iida Department of Emergency and Critical Care Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Nobuyuki Nosaka Department of Emergency and Critical Care Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Tetsuya Yumoto Department of Emergency and Critical Care Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Emily Knaup Department of Emergency and Critical Care Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Hiromichi Naito Department of Emergency and Critical Care Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Chihiro Nishiyama Department of Emergency and Critical Care Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Yasuaki Yamakawa Department of Emergency and Critical Care Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Kohei Tsukahara Department of Emergency and Critical Care Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Michihisa Terado Department of Emergency and Critical Care Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Keiji Sato Department of Emergency and Critical Care Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Toyomu Ugawa Department of Emergency and Critical Care Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Atsunori Nakao Department of Emergency and Critical Care Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Review 10.18926/AMO/54590 In recent years, it has become evident that molecular hydrogen is a particularyl effective treatment for various disease models such as ischemia-reperfusion injury; as a result, research on hydrogen has progressed rapidly. Hydrogen has been shown to be effective not only through intake as a gas, but also as a liquid medication taken orally, intravenously, or locally. Hydrogenʼs effectiveness is thus multifaceted. Herein we review the recent research on hydrogen-rich water, and we examine the possibilities for its clinical application. Now that hydrogen is in the limelight as a gaseous signaling molecule due to its potential ability to inhibit oxidative stress signaling, new research developments are highly anticipated. No potential conflict of interest relevant to this article was reported.

Okayama University Medical School Acta Medica Okayama 0386-300X 70 3 2016 Involvement of Xanthine Oxidoreductase-related Oxidative Stress in a Dermatophagoides farinae-induced Asthma Model of NC/Nga Mice 175 182 EN Heri Setiawan Department of Public Health, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Kenjiro Nagaoka Department of Public Health, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Masayuki Kubo Department of Public Health, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Yoshihisa Fujikura Division of Morphological Analysis, Department of Anatomy, Biology and Medicine, Faculty of Medicine, Oita University Keiki Ogino Department of Public Health, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Original Article 10.18926/AMO/54416 Oxidative stress is widely known to play a role in asthma. However, the contribution of xanthine oxidoreductase (XOR) as a source of the superoxide anion radical (O2−) in oxidative stress associated with asthma has not yet been examined in detail. Here we investigated pathophysiological changes in XOR in an experimental model of asthma induced by the house dust mite Dermatophagoides farinae (Df). In the lungs of Df-treated mice, the production of O2− from XOR increased and the nitrite concentrations decreased, whereas the protein expression of XOR remained unchanged. Moreover, the protein expression levels of XOR and the hydrogen peroxide (H2O2) concentrations in bronchoalveolar lavage fluid (BALF) were higher in the Df-treated mice than in saline-treated mice. Immunohistochemically, although XOR was highly localized in the bronchial epithelial cells of the saline-treated mice, immunostaining for XOR was absent in the bronchial epithelium of Df-treated mice. These results suggest that oxidative stress is up-regulated by increases in the conversion of the dehydrogenase form (xanthine dehydrogenase; XDH) of XOR to the oxidase form (xanthine oxidase; XOD). No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 2015 Mixture Formation Measurement of Transient Hydrogen Jet in Constant-Volume Vessel Using Spark Induced Breakdown Spectroscopy (SIBS) EN Md Tasyrif bin Abdul Rahman No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 2045-2322 4 2014 Effects of hydrogen-rich water on aging periodontal tissues in rats EN Takaaki Tomofuji Yuya Kawabata Kenta Kasuyama Yasumasa Endo Toshiki Yoneda Mayu Yamane Tetsuji Azuma Daisuke Ekuni Manabu Morita Oxidative damage is involved in age-related inflammatory reactions. The anti-oxidative effects of hydrogen-rich water suppress oxidative damage, which may aid in inhibiting age-related inflammatory reactions. We investigated the effects of drinking hydrogen-rich water on aging periodontal tissues in healthy rats. Four-month-old male Fischer 344 rats (n = 12) were divided into two groups: the experimental group (hydrogen-rich water treatment) and the control group (distilled water treatment). The rats consumed hydrogen-rich water or distilled water until 16 months of age. The experimental group exhibited lower periodontal oxidative damage at 16 months of age than the control group. Although protein expression of interleukin-1 beta did not differ, gene expression of Nod-like receptor protein 3 inflammasomes was activated in periodontal tissues from the experimental group as compared with the control group. Drinking hydrogen-rich water is proposed to have anti-aging effects on periodontal oxidative damage, but not on inflammatory reactions in healthy rats. No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 2014 Hydrogen-rich water attenuates experimental periodontitis in a rat model EN Kenta Kasuyama No potential conflict of interest relevant to this article was reported.

岡山医学会 Acta Medica Okayama 0030-1558 125 3 2013 NASHに対する水素分子の有用性 201 204 EN Daisuke Kawai Akinobu Takaki Kazuhide Yamamoto No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 2013 Comparison of serum ferritin and oxidative stress biomarkers between Japanese workers with and without metabolic syndrome EN Suketaka Iwanaga Noriko Sakano Kazuhisa Taketa Noriko Takahashi Da-Hong Wang Hidekazu Takahashi Masayuki Kubo Nobuyuki Miyatake Keiki Ogino Objective Metabolic syndrome (MS) is closely associated to life-style and is characterized by central obesity causing severe diseases such as diabetes mellitus (DM) or atherosclerosis. This study investigates the role of oxidative stress and inflammation in MS. Subjects Total of 685 workers stratified by gender (293 men and 392 women) with a mean age of 41.2 ± 10.4 in different offices in a city in Japan. Methods Fasting blood and urine tests for MS, oxidative and/or inflammatory biomarker analysis and blood pressure (BP) measurement were performed. MS was defined on the basis of the Japanese criterion. Results Serum ferritin and urinary hydrogen peroxide (H2O2) levels were significantly higher in subjects with MS than those without. Ferritin was positively correlated with 8-hydroxy-2′-deoxyguanosine (8-OHdG) in all subjects and it was negatively correlated with 8-isoprostane and H2O2 in men. In addition, there was a significant positive correlation between ferritin and homeostasis model assessment (HOMA-R) in men. By using multiple regression analysis, ferritin was closely correlated with HOMA-R, γ-GT, 8-OHdG, smoking value and amount of alcohol ingestion in men, and it was correlated with 8-OHdG, γ-GT, HOMA-R in women under 50 years old. Conclusions Ferritin is a useful marker of MS including insulin resistance, reflecting the importance of oxidative stress as a cause of MS, especially in men. No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 0385-5414 86 2 2012 Synthesis of 2-Acetamido-2,5-dideoxy-5-phosphoryl-D-glucopyranose Derivatives: New Phospha-sugar Analogs of N-Acetyl-D-glucosamine 1147 1165 EN Tadashi Hanaya Masahiro Kawaguchi Masakazu Sumi Kazuo Makino Keiko Tsukada Hiroshi Yamamoto Starting with N-acetyl-D-glucosamine, methyl 2-acetamido-3,6-di-O-benzyl-2-deoxy-beta-D-xylo-hexofuranosid-5-ulose (18) was prepared in 7 steps. The addition reaction of dimethyl phosphonate to 18, followed by deoxygenation of its 5-hydroxy group, provided the 5-deoxy-5-dimethoxyphosphoryl-D-glucofuranoside derivative (21a). The hydride reduction of 21a, followed by the action of hydrochloric acid and then hydrogen peroxide, afforded the first D-glucosamine analog (23) having a phosphoryl group in the hemiacetal ring. This was converted into the per-O-acetylated N-acetyl-D-glucosamine phospha-sugar (25), while the same treatment of the 5-deoxy-5-dimethoxyphosphoryl-L-idose dimethyl acetal derivative (13b) afforded the N-acetyl-L-idosamine phospha-sugar (29). No potential conflict of interest relevant to this article was reported.

Informa Healthcare Acta Medica Okayama 1071-5762 47 3 2013 Evaluation of urinary hydrogen peroxide as an oxidative stress biomarker in a healthy Japanese population 181 191 EN Y. Sato K. Ogino N. Sakano D. H. Wang J. Yoshida Y. Akazawa S. Kanbara K. Inoue M. Kubo H. Takahashi The usefulness of urinary hydrogen peroxide (H2O2) as an oxidative stress biomarker was evaluated in 766 healthy Japanese. The mean level of urinary concentrations of H2O2 was 5.66 +/- 8.27 mu mol/g creatinine, and was significantly higher in females than in males. Significant correlations of H2O2 were observed with age, aspartate aminotransferase (AST), alanine aminotransferase (ALT), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-c), insulin, 8-hydroxy-2'-deoxyguanosine (8-OHdG), and exercise habit in females. In both sexes, H2O2 showed a significant correlation with 8-OHdG. By a multiple logistic regression analysis, urinary H2O2 was positively associated with urinary 8-OHdG and TC and was inversely associated with insulin. By stratification of sex and age, the association of urinary H2O2 with TC was positive in both sexes under 50 years old and was inverse in males over 50 years old, and that with insulin was inverse in males over 50 years old and in females under 50 years old. Moreover, by stratification of sex and age, a positive association of H2O2 with exercise and an inverse association of H2O2 with alcohol consumption became clear in males under 50 years old, although there were no significant odds for H2O2 after adjustment for covariates. In conclusion, the present results suggest that urinary H2O2 is a useful biomarker for oxidative stress, showing an association with 8-OHdG, TC, and insulin independently. No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 2013 Evaluation of urinary hydrogen peroxide as an oxidative stress biomarker in a healthy Japanese population EN Yoshie Sato No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 2013 Investigation of Different Injection Strategies and Local Mixture Concentration for Jet-guided Combustion in a Hydrogen Direct Injection Spark-Ignition Engine EN Mithun Kanti Roy No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 2013 Hydrogen-rich water prevents progression of non-alchoholic steatohepatitis and accompanying hepatocarcinogenesis in mice EN Daisuke Kawai No potential conflict of interest relevant to this article was reported.

Elsevier Science B.V. Acta Medica Okayama 00219673 1288 2013 Determination of association constants between 5 '-guanosine monophosphate gel and aromatic compounds by capillary electrophoresis 149 154 EN Kaori Yamaguchi Nobuyuki Takeyasu Takashi Kaneta Hydro gel formed by 5'-guanosine monophosphate (GMP) in the presence of a potassium ion is expected to exhibit interesting selectivity in capillary electrophoretic separations. Here, we estimated the conditional association constants between the hydro gel (G-gel) and aromatic compounds by capillary electrophoresis in order to investigate the separation selectivity that is induced by the G-gel. Several aromatic compounds were separated in a solution containing GMP and potassium ion at different concentrations. The association constants were calculated by correlating the electrophoretic mobilities of the analytes obtained experimentally using a concentration of G-gel. During semi-quantitative estimation, naphthalene derivatives had larger association constants (K-ass = 10.3-16.8) compared with those of benzene derivatives (K-ass = 3.91-5.31), which means that the binding sites of G-gel match better to a naphthalene ring than to a benzene ring. A hydrophobic interaction was also found when the association constants for alkyl resorcinol were compared with those of different hydrocarbon chains. The association constants of nucleobases and tryptophan ranged from 6.05 to 12.6, which approximated the intermediate values between benzene and naphthalene derivatives. Consequently, the selective interaction between G-gel and aromatic compounds was classified as one of three types: (1) an intercalation into stacked planar GMP tetramers; (2) a hydrophobic interaction with a long alkyl chain; or, (3) a small contribution of steric hindrance and/or hydrogen bonding with functional groups such as amino and hydroxyl groups. No potential conflict of interest relevant to this article was reported.

Verlag des Ōhara Instituts Acta Medica Okayama 4 3 1930 Investigation on Antimony Electrode for Determination of Hydrogen Ion Concentration. II. Determination of the hydrogen ion concentration of soils. 383 394 EN Arao Itano Satiyo Arakawa No potential conflict of interest relevant to this article was reported.

Verlag des Ōhara Instituts Acta Medica Okayama 4 2 1929 Investigation on Antimony Electrode for Determination of Hydrogen Ion Cencentration. I. Standardization of an antimony electrode in the buffer solutions and calculation of PH. 273 277 EN Arao Itano No potential conflict of interest relevant to this article was reported.

Verlag des Ōhara Instituts Acta Medica Okayama 4 2 1929 Tables of PH Values corresponding to Electromotive Forces determined in Hydro-quinhydrone，Qninhydrone，Hydrogen，and Antimony Electrode against N/IO and saturated KCl Calomel and Quinhydrone Standard Electrode. 199 253 EN Arao Itano No potential conflict of interest relevant to this article was reported.

Biomed Central Ltd Acta Medica Okayama 1471-2369 13 14 2012 Acatalasemic mice are mildly susceptible to Acatalasemic mice are mildly susceptible to adriamycin nephropathy and exhibit increased albuminuria and glomerulosclerosis EN Keiichi Takiue Hitoshi Sugiyama Tatsuyuki Inoue Hiroshi Morinaga Yoko Kikumoto Masashi Kitagawa Shinji Kitamura Yohei Maeshima Dahong Wang Noriyoshi Masuoka Keiki Ogino Hirofumi Makino Background: Catalase is an important antioxidant enzyme that regulates the level of intracellular hydrogen peroxide and hydroxyl radicals. The effects of catalase deficiency on albuminuria and progressive glomerulosclerosis have not yet been fully elucidated. The adriamycin (ADR) nephropathy model is considered to be an experimental model of focal segmental glomerulosclerosis. A functional catalase deficiency was hypothesized to exacerbate albuminuria and the progression of glomerulosclerosis in this model. Methods: ADR was intravenously administered to both homozygous acatalasemic mutant mice (C3H/AnLCs(b)Cs(b)) and control wild-type mice (C3H/AnLCs(a)Cs(a)). The functional and morphological alterations of the kidneys, including albuminuria, renal function, podocytic, glomerular and tubulointerstitial injuries, and the activities of catalase were then compared between the two groups up to 8 weeks after disease induction. Moreover, the presence of a mutation of the toll-like receptor 4 (tlr4) gene, which was previously reported in the C3H/HeJ strain, was investigated in both groups. Results: The ADR-treated mice developed significant albuminuria and glomerulosclerosis, and the degree of these conditions in the ADR-treated acatalasemic mice was higher than that in the wild-type mice. ADR induced progressive renal fibrosis, renal atrophy and lipid peroxide accumulation only in the acatalasemic mice. In addition, the level of catalase activity was significantly lower in the kidneys of the acatalasemic mice than in the wild-type mice during the experimental period. The catalase activity increased after ADR injection in wild-type mice, but the acatalasemic mice did not have the ability to increase their catalase activity under oxidative stress. The C3H/AnL strain was found to be negative for the tlr4 gene mutation. Conclusions: These data indicate that catalase deficiency plays an important role in the progression of renal injury in the ADR nephropathy model. No potential conflict of interest relevant to this article was reported.

岡山医学会 Acta Medica Okayama 0030-1558 33 372 1921 ELECTRIC CHARGES OF THE RED BLOOD CORPUSCLES 1 34 EN K. Kosaka M. Seki 1. It is stated that the erythrocytes show a different cataphoresis in the same solution according to the species of the animals and the erythrocytes of the same animal in two different solutions. 2. The erythrocytes of the rabbit possess in 0,9% NaCl solution a positive charge unlike those of the other animals, while they are charged in the isotonic sugar solution most negatively charged. 3. The cataphoresis of the erythrocytes was observed under the microscope not only in the NaCl solution but in many other salt solutions. 4. The statement follows how the cataphoretic phenomena which the erythrocytes show in the isotonic solution of NaCl or cane-sugar are modified by the addition of several reagents. 5. A test is made showing the change of pH of different solutions after the addition of the erythrocytes. 6. It is demonstrated that some Cl-ions in solutions of NaCl or KCl are taken by the erythrocytes which in turn give off some HCO3-ions. 7. Of all the animals the efficiency of the erythrocytes to raise pH of some salt solutions, especially of acid salt solutions is the greatest in the rabbit and the least in the dog as far as they were examined. 8. On the other hand the erythrocytes of the rabbit have a weaker efficacy to neutralize an alkaline solution than those of the dog, guinea-pig or goat. 9. While the erythrocytes absorb some Cl-ions in an acid salt solution, they release these in an alkaline salt solution. 10. The strong efficiency of the rabbit erythrocytes to raise pH of some solutions is an important factor, the explanation, perhaps, being that they possess a positive charge in the salt solution unlike those of almost all other animals. Likewise the fact that the erythrocytes of the dog have a strong negative charge in the salt solution seems to bear upon their weak efficacy to neutralize an acid solution. 11. In order to explain the cataphoresis of the erythrocytes in the sugarsolution a hypothesis is offered concerning the permeability of the membrane of the erythrocytes. If the erythrocytes of the rabbit are thrown into a sugar solution which contains no electrolytes, there would occur a condensation of the cell membrane, so that it would hinder the passage of some anions, while the diffusion of cations goes on unaffected. On the other hand the permeability of the erythrocytes of the dog and cat seems to remain almost unchanged in the sugar solution as well as in the salt solution. For this reason the erythrocytes of the rabbit become in the sugar-solution strongly negatively charged, while those of the dog and cat remain weakly negatively charged. 12. Such solutions as 3,0% glycerine, 5,0% d-glucose, 5,0% laevulose, 9,5 % lactose and 2,0% glycocoll have the same effect as that of 9,5% canesugar solution on the cataphoresis of the erythrocytes. 13. The erythrocytes of the rabbit which have a strong power to neutralize an acid solution and are slightly positively charged in 0,9% NaCl solution resist the haemolytic effect of the acid more obstinately than those of other animals. On the contrary the crythrocytes of the goat which show a strong negative potential in 0,9% NaCl solution are most liable to the haemolysis caused by the acid. Generally speaking it seems probable that erythrocytes which are strongly negatively charged in the NaCl solution dissolve in an acid solution more easily than those weakly charged. 14. But in a solution of reserve acidity in which some substance acts as "buffer" the erythrocytes of the rabbit are most liable to haemolysis, while those of the goat and dog show a great resistance at least during the first few hours. 15. The erythrocytes of the dog are most easily dissolved in the alkaline solution. With this special exception, the erythrocytes of the rabbit are most liable to haemolysis and those of the goat and rat show the greatest resistance when they are thrown into the solution. Generally speaking it seems probable, that less negatively charged erythrocytes in the NaCl solution are more liable to the haemolytic effect of the base, the case of the dog being excluded. 16. Those elements which possess lower solution pressures than hydrogen have generally a strong power to dissolve or destroy the erythrocytes, and less negatively charged erythrocytes seem to be more liable to haemolysis in solutions of the copper, mercury, silver, gold or platinum compounds. 17. Those elements which possess higher solution pressures than hydrogen have generally only a weak haemolytic effect or none at all, but the trivalent cations Fe(…) and Al(…) are powerful in causing haemolysis, their effect resembling that of the acid. 18. The haemolytic effect of saponin, natrium oleat and alcohol has no bearing on the electric charge of the erythrocytes and seems to be chiefly concerned with the action to dissolve the lipoid. 19. Likewise the haemolysis caused by hypotonic solutions has no relation to the electric charge of the erythrocytes.20. The resistance of the erythrocytes towards hypotonic NaCl solutions is increased by the effect of the alkali and decreased by that of the acid (HAMBURGER). This change is seen very markedly in the goat erythrocytes which have a strong negative potential, while the positively charged erythrocytes of the rabbit in such cases show very little or no change at all. 21. The haemolytic serum has a power to neutralize the charge of the erythrocytes. This action must be attributed to either the amboceptor or agglutinin, the complement having surely nothing to do with it. An experiment on the goat erythrocytes gave a result, which seems to suggest, that the amboceptor acts upon the erythrocytes more effectually than the agglutinin, as far as the electric charge is concerned. No potential conflict of interest relevant to this article was reported.

Nature Publishing Group Acta Medica Okayama 0028-0836 473 7345 2011 Crystal structure of oxygen-evolving photosystem II at a resolution of 1.9 Å 55 60 EN Yasufumi Umena Keisuke Kawakami Jian-Ren Shen Nobuo Kamiya Photosystem II is the site of photosynthetic water oxidation and contains 20 subunits with a total molecular mass of 350 kDa. The structure of photosystem II has been reported at resolutions from 3.8 to 2.9 angstrom. These resolutions have provided much information on the arrangement of protein subunits and cofactors but are insufficient to reveal the detailed structure of the catalytic centre of water splitting. Here we report the crystal structure of photosystem II at a resolution of 1.9 angstrom. From our electron density map, we located all of the metal atoms of the Mn(4)CaO(5) cluster, together with all of their ligands. We found that five oxygen atoms served as oxo bridges linking the five metal atoms, and that four water molecules were bound to the Mn(4)CaO(5) cluster; some of them may therefore serve as substrates for dioxygen formation. We identified more than 1,300 water molecules in each photosystem II monomer. Some of them formed extensive hydrogen-bonding networks that may serve as channels for protons, water or oxygen molecules. The determination of the high-resolution structure of photosystem II will allow us to analyse and understand its functions in great detail. No potential conflict of interest relevant to this article was reported.

Elsevier Science SA. Acta Medica Okayama 0022-328X 696 1 2011 Rhenium-catalyzed insertion of terminal alkenes into a C(sp(2))–H bond and successive transfer hydrogenation 348 351 EN Yoichiro Kuninobu Takahiro Nakahara Peng Yu Kazuhiko Takai Treatment of aromatic aldimines with terminal alkenes in the presence of a rhenium catalyst, [HRe(CO)(4)](n), gives 2-alkenylbenzylamines in good to excellent yields. This reaction proceeds via the insertion of the alkene into a C-H bond at the ortho-position of the imino group of the aromatic aldimine followed by sequential beta-hydride elimination from the formed alkyl rhenium intermediate and then by hydrogenation of the imino group of the aldimine. No potential conflict of interest relevant to this article was reported.

岡山医学会 Acta Medica Okayama 0030-1558 68 11 1956 無カタラーゼ血液症に於るカタラーゼ量，ペルオキシダーゼ量並に家鴨，鵞鳥，鳩に於るカタラーゼ量に就て 第二編 家鴨，鵞鳥，鳩の各臓器組織カタラーゼ量に就て 2175 2183 EN Shin Mihara I examined the quantity of catalase in organ's tissues of wild duck, goose and pigeon, whose blood in reacting to hydrogen peroxide showed a close resemblance to the blood acatalasemia cases. When we poured hydrogen peroxide on to the blood of these fowl, the blood discolored immediately into a blackish color, and at that time no generation of bubbles could be seen. I used Warburg's manometric method and following results were obtained: I found that Qcat. of blood and bone marrow of these fowl showed an extremely low number, while the Qcat. of liver, kidney and small intestine of these fowl were almost equal index number to those of other animals. No potential conflict of interest relevant to this article was reported.

岡山医学会 Acta Medica Okayama 0030-1558 69 10 1957 発育電位時間曲線によるチフス菌代謝の研究 第3編 電位における二基質の相互作用 2631 2635 EN Kazuo Akita In the present part, the author studied the interaction of two substrates to oxidation-reduction potential. Salmonella typhi 57 S was used as the test organism. The results were as follows: 1) The combination of glucose and glutamate, markedly accelerated the fall of potential, while those of glucose and alanine, and glucose and lactate accelerated it moderately. 2) The combinations of aspartate and lactate, glutamate and lactate, malate and glutamate, alanine and malate, and aspartate and alanine did not noticeably accelerate the fall of potential. 3) In the combinations of aspartate and glucose, and lactate and alanine, contrary to the above-mentioned ones, the fall of potential was less than that in each of the substrates. 4) As the cause for the effect of the combinative administration of two substrates, transamination will play a very important role, and the opinion that the hydrogen production by hydrogenlyase is the only cause for the rapid fall of potential, can not be approved as a whole. The essential cause will be, however, disclosed by the studies in future. No potential conflict of interest relevant to this article was reported.

岡山医学会 Acta Medica Okayama 0030-1558 69 4 1957 Formalin変性蛋白の物理化学的性質に就て 1031 1037 EN Nobuo Otsuka Physicochemical properties of formalized proteins were studied. Decline of hydrogen ion concentration of formalized proteins was noticed in the high concentrations of formalin, while incline in the low concentrations. Colorization of formalized proteins, caused by Folin's phenol reagent, was depressed with increase of concentration of formalin. There was found increased turbidity of formalized proteins with increase of concentration of formalin. On paper electrophoresis marked changes were observed in the higher concentrations of formalin, while in the lower concentrations, slight changes were noticed compared with the controls. No potential conflict of interest relevant to this article was reported.

岡山医学会 Acta Medica Okayama 0030-1558 69 3 1957 ハインツ氏小体に関する研究 第一編 ハインツ氏小体出現を中心として観たビキニ水爆症及び実験的放射能障碍家兎に就て 627 647 EN Tetsuro Saito By determining at first the appearance of Heinz's body in man and male domestic rabbits, both normal, with the Yoshida-Kawamura method, and next by investigating the rate of the appearance of Heinz's body in Bikini hydrogen-bomb patients and in the domestic rabbits injected with radio-isotope P(32) as well as in the rabbits exposed to X-ray, the author obtained the following results: 1. Two separate groups of male and female, each consisting of 25 persons, were selected and the rate of the Heinz-body appearance was determined; and as the result, the average rates of the appearance of each were found to be 63.88‰ (male) and 66.52‰ (female) respectively; thus the average value of females was slightly higher. On the other hand, in the 62 normal male rabbits similarly measured, the average value of the appearance of Heinz's body was found to be 22.19‰. 2. In the case of the 7 fishermen passing through the Bikini area and having shown no apparent clinical disorders, the rate of Heinz-body appearance was found to be still high, yet within 3 to 4 weeks after the examination, it returned to normal, paralleling more or less with the change of blood-iron contents, Sideroblastogram, and the results of Bone marrow tissue culture. In view of this, in establishing a criterion of the recovery of these hydrogenbomb cases, it seems that scrupulous daily examinations such as mentioned previously are of urgent necessity. 3. In the domestic rabbits receiving the injection of 100 μc. P(32)/kg, Heinz's body increased 6 hours after the injection but it returned to normal after 20 to 42 days; even then they maintained a high value of blood-iron contents and showed an unmistakable evidence of radio-active substance in the bone as well. Whereas those rabbits receiving the dose of 850 μc. P(32)/kg showed the increase of Heinz's body either 30 minutes or 3 hours after the injection, and after 48 hours and 28 days respectively their values reached close to 1, 000‰ and continuously showing an intermediately progressive trend, they all died. The blood counts of capillary leucocytes in the case of the rabbit No.58 returned to normal 28 days after the injection, but the percentage of capillary leucocytes, the blood counts of erythrocytes, and the bone picture were still abnormal and radio-active substance could be recognized in the bone. Heinz's body, however, did not appear in the control injected with primary potassium phosphate. 4. Among the 6 rabbits suffering from acute X-ray radiation, and the five from chronic, three of the latter and all the acute cases revealed a progressive proclivity to the formation of Heinz's body before their death. No potential conflict of interest relevant to this article was reported.

岡山医学会 Acta Medica Okayama 0030-1558 69 1 1957 実験的硫化水素中毒の病理組織学的研究 第2編 特に脳下垂体・松果腺・甲状腺・上皮小体・胸腺・副腎及び睾丸の変化に就て 157 182 EN Ryozo Kuwahara Histologic observation was made on the lesons in various endocrine glands of the mouse and rabbit caused by hydrogen sulfide poisoning. The results are briefly summarized as follows: 1. The Hypophysis. In the anterior lobe, the chromophobe cells markedly decreased in number and displayed an irregular arrangement. The alpha cells showed the decrease of acidophilic granules in number and of cytoplasm in size, and the younger forms of the alpha cells markedly increased. The beta cells increased both in size and in number with the cytoplasm crowded with basophilic granules. The cells in the pars intermedia were deeply stained, the cytoplasm becoming compact in structure. 2. The Pineal gland. The gland cells showed a considerable atrophy, the cell borders becoming less distinct, and pycnotic nuclei seeming to crowd closely together. 3. The Thyroid gland. The lumens of the follicules were dilated with a marked increase of diluted colloid in amount. The colloid became quite homogenous with the disappearance of all vacuoles, and the follicular epithelium showed a low cuboidal or flat form. 4. The Parathyroid glands. The principal cells increased in size with the cytoplasm crowded with deeply stained granules in their central zone and faintly stained in their peripheral zone. The nuclei were also large in size, having vesicular appearance. 5. The Thymus. The bulk of the thymus was increased in general. The cortical cells decreased in number, the cortex thinning remarkably, while the medulla showed generally a marked hyperplasia, especially the Hassal's bodies increased in number showing a marked hypertrophia with advanced hyperkeratosis. 6. The Adrenal glands. The cells of the zona glomerulosa in the cortex showed hyperplasia with an abundant cytoplasm and vesicular nucleus. The lipid content in the cells of the zona fasciculata was decreased, and their cytoplasms were stained deeply. The bulk of the medulla was increased by the hypertrophy of the medullar cells with polygonal cytoplasm crowded with deeply stained granules and a large vesicular nucleus embedded. The chrome reaction proved highly positive. 7. The Testis. Decline or absence of spermatogenesis was seen in some parts of the seminiferous tubuli. In some cases, the seminiferous epithelium occasionally displayed a marked atrophy or degeneration. The changes mentioned above showed no difference in quality but in intensity according to the kind of animals and methods used. No potential conflict of interest relevant to this article was reported.

岡山医学会 Acta Medica Okayama 0030-1558 69 1 1957 実験的硫化水素中毒の病理組織学的研究 第1編 特に唾液腺及び膵臓の変化に就いて 143 156 EN Ryozo Kuwahara Histologic observation was made on the lesions in the salivary glands and pancreas of the mouse and rabbit caused by hydrogen sulfide poisoning. From the data obtained the present author concluded that the poisoning causes definite histologic changes in these tissues as follows: 1. In the parotid glands, the gland cells show a marked atrophy with a tendency of close arrangement of secretion glanules in the cytoplasm, and with a vacuolar degeneration or appearance of basement membrane. Moreover, the epithelium of the striated tubules decreases its height. 2. In the submaxillar salivary glands, the gland cells as well as the epithelial cells of the striated tubules show a high degree of atrophy with a marked decrease of secretion glanules. Vacuolar or collagenous degeneration is also seen in the gland cells. 3. In the pancreas, the acinar cells are degenerated with a marked decrease of zymogen granules and a vacuolar degeneration in the cytoplasm, resulting in a appearance of the basement membrane. Islets of Langerhans increase their sizes with the remarkable increase in number of beta cells and the slight increase of alpha cells. These changes show that the hydrogen sulfide poisoning causes a marked decline and disturbance of excretory function in the salivary glands and pancreas. According to the methods used in the poisoning, there is no difference in quality of the changes, but more or less difference in their intensity, the higher degree of changes are caused by injection than by inhalation and intragastric introduction of hydrogen sulfide. No potential conflict of interest relevant to this article was reported.

岡山医学会 Acta Medica Okayama 0030-1558 69 1 1957 放射線とHeinz小体 附. 昭和29年3月ビキニ環礁水爆実験の被害船第5福龍丸船員の赤血球Heinz小体に就て 103 107 EN Michio Yamamoto Soichi Nishishita Tadashi Hashigami Koki Yamamoto Mizuho Kanda Kimimasa Mimura Yukio Shigenobu Noruo Hamada It has been demonstrated that the formation of so-called Heinz's body in erythrocytes could be brought forth by the use of radioactive phosphorous (P(32)) in both vivo and in vitro. The Heinz's body formation was also recognized in erythrocytes in general of the blood obtained from the ship's crews of the Fukuryu Maru who had been subjected to an influence of the hydrogen bomb experimental trialx in Bikini on March 1954, and examined when red blood cells have been suspended in physiological salt solution and left for 6-9 hours in an incubator at the temperature of 37°C. The finding of Heinz's body in the red blood cells of the crews of the above vessel may have been attributed to the lowered functional capacity of the reticuloendothelial system, speaks for erythrocytes susceptible to undergo retrogressive degenerative change. No potential conflict of interest relevant to this article was reported.

岡山医学会 Acta Medica Okayama 0030-1558 71 12-2 1959 Verdohemochromeの生成とその性状に関する研究 第1編 Pyridine hemin-Hydrazine-O(2)反応系によるVerdohemochromeの生成に関する分光化学的研究 8325 8336 EN Shigeo Katami The influence to the formation of verdohemochrme was spectrochemically observed on the action of hydrazine sulphate and oxygen to pyridine hemin in various changes of the reacting condition and the formation process of the product with the absorption maximum at 630 mμ was spectrochemically observed on the action of hydrogen peroxide and hydrazine sulphate to pyridine hemin under the airless condition. And the results were as follows. 1. In this reaction system, the influence of pH was great, the formation dosis of verdohemochrome was low on the high pH-value of reaction solution, the reaction was slow and the formation dosis of verdohemochrome was declined on the pH-value around 7.0, and it was decided that the pH-value at 8.5-8.0 was the most suitable. 2. The pyridine concentraticn was the most suitable in 20% of absolute concentration, the reacting process was not good below 20% and the decomposition of verdohemochrome was promoted on the over dosis. 3. There was the correlation between the hemin concentration and hydrazine concentration, the most proper concentration rate was needed and the dosis of hydrazine sulphate was needed in 10 or 25 times' Mol. concentration of hemin dosis. 4. The most proper concentration of hemin was 20mg/dl, when the concentration of hydrazine sulphate was made to be the most proper concentration rate to the hemin concentration. 5. In the reaction using hydrazine sulphate, the shaking of flask at 50°C was necessary and it was more slow in comparison with the reaction using ascorbic acid. 6. The formation of the product with the absorption maximum at 630 mμ was certified in the pyridine hemin-hydrazine-H(2)O(2) reaction system and the absorption maximum was easily shifted to 650mμ on the aeration of oxygen to the above product. 7. In this reaction system, it persevered the absorption of pyridine hemichrome, and the absorption picture of pyridine hemochrome was observed on the progression of the pyridine hemin-hydrazine-H(2)O(2) reaction system under the airless condition. 8. Since the above results, it was understood that the oxydation-reduction potential in the hydrazine reaction system was much different in comparison with that of the 1-ascorbic acid reaction system. No potential conflict of interest relevant to this article was reported.

岡山医学会 Acta Medica Okayama 0030-1558 71 11-1 1959 胆汁色素に関する研究 第1編 Dihydrobilirubinの化学的性状に就て 7185 7191 EN Toshiro Mitsumoto 1. When dihyrobilirubin is prepared from crystalline bilirubin by direct contact reduction with the use of collagenous palladium, at least over 100 mg crystalline bilirubin is required and it is necessary to saturate callagenoes palladium sufficiently with hydrogen before the use. 2. Crystal of dihydrobilirubin isolated from pyridine solution or isolateid by column chromatography, when dissolved in chloform solution, shows the absorpton peak at 437 mμ on the absorption curve. 3. In the primary elevation paper chromtography of dihydrobilirubin conducted at 20°C using Schleicher and Schüll-No.2043 filter paper when the developing agent is acetone-water-ammonia in the proportion of 80: 15.5, Rf equals 0.02; while when the combination is in the ratio of 40:50:10, Rf equals 0.10. 4. When dihydrobilirubin previously added with iodine is made to undergo Schlesinger reaction, it turns bluish green, emanating red fluorescent light, and shows the absorption peak at 630 mμ and 585 mμ on its absorption curve. 5. Oxide of dihydrobilirubin is greenish blue, and when it is dissolved in a 5% methanol hydrochloride, the absorption curve shows the peak at 675 mμ and 365 mμ. 6. When a dihydobilirubin serum solution is put to filter paper electrophoresis, it acts in combination with serum albumin. No potential conflict of interest relevant to this article was reported.

岡山医学会 Acta Medica Okayama 0030-1558 71 10-1 1959 EDTAの細菌に対する影響に関する研究 第2編 EDTA加培養基に発育せる細菌の酵素的性状に就いて 6563 6569 EN Yoshiaki Kukida Using Sal. 57 S, the auther carried out the investigation on the enzymatic properties of EDTA resistant bacteria grown on EDTA added nutrient agar media in comparison to normal Sal. 57S. The following results were obtained 1) On oxidatinn of glucose, the normal bacteria oxidized it mostly through the EMBDEN-MEYERHOF pathway. But in the EDTA resistant bacteria the oxidaition pathway was supposedly via WARBURG-DICKENS shunt, While there were evidence of passing through the EMBDEN-MEYERHOR pathway to some extent. 2) Further oxidation beyond pyrvate stage was strongly inhibited in EDTA resiseant bacteria. 3) The enzymatic change mentioned above was easily restored to the normal by the shrot time incubation of the organism. 4) It was postulated no change occured in the hydrogen transfer system. No potential conflict of interest relevant to this article was reported.

岡山医学会 Acta Medica Okayama 0030-1558 71 10-1 1959 Dimethoxyisoquinoline誘導体についての二，三薬理学的検索 6223 6230 EN Akio Kuroda Kei Jinzenji Takashi Yamamoto Kazuji Kondo Junzo Shoda Twelve members of a new series of 1-trialkylmethyl-1-6, 7-dimethoxy-3, 4-dihydroisoquinoline (D type) and eleven analogs of 1-trialkylmethyl-6, 7-dimethoxy isoquinoline (I type) were investigated for their pharmacological properties, with special reference to the toxicity and spasmolytic activity, comparing with papaverine. Along these isoquinoline, 1-methylisoquinoline, 6, 7-dimethoxyisoquinoline and their respective 3, 4-hydrogenated derivatives, were also examined for the elucidation of structure-activity relationship. All the compounds of D type produced a marked inhibitory action on the isolated rabbit intestine. The most potent members were n-tripropyl, ethyl-n-propyl-n-butyl and methyl-ethyl-n-butyl derivatives. Their spasmolytic actions on both barium and histamine contraction of the intestine exceeded those of papaverine, though the effect on acetylcholine spasm was slightly inferior. They were less toxic in mice than in the latter. The intestine inhibitory activity and toxicity of I Type compounds were both smaller than those of D type analogs. The differences between the two types seemed to be related to the solubility. Other smaller components of the papaverine structure, namely, the primitive isoquinoline derivatives were more toxic, but much less spasmolytic than papaverine. In mice toxic doses of all the compounds caused tremors, excitability and convulsions followed by a generalized central depression. Respiratory paralysis may be direct cause of death. Toxic symptoms were generally similar to those in frogs. The stimulant properties were increased by the saturation of the 3, 4-position on the isoquinoline nucleus. No potential conflict of interest relevant to this article was reported.

岡山医学会 Acta Medica Okayama 0030-1558 71 9-1 1959 骨髄組織培養法による骨髄巨核球に関する研究 第3編 各種培養条件の人並びに海溟骨髄巨核球に及ぼす影響について 5477 5491 EN Kenjiro Ogawara In perfoming bone-marrow tissue culture of human and guinea pigs the author observed the influences of the temperature, the osmotic pressure and the hydrogen ion concentration of the media on magakaryocytes; and obtained the following results. 1. The range of temperature at which megakaryoctyes can move about is from 30°C the minimum to 41°C the maximum, and the optimal temperature is around 35° to 39°C. The fromation of tentacle-like processes can be observed at the optimal temperature and most suitable temperature is about 38°C. 2. On the whole the vaculole formation can be seen markedly at a relatively low temperature, while the formation of secretion granules tends to appeare more promptly at a higher temperature than than at a low temperature. 3. More megakaryocytes appear in the growth zone in a relatively hyposmotic pressure (ΔT=-0.43 to -0.45) than in isotonic, and also the acceleration of the cell motility can be recognized in the case of human bene marrow, but it seems to be due to a transient stimulation. On the other hand, in the hyperosmotic pressure hardly any formation of tentacle-like processes in megakaryocytes can be recongized. 4. Degenerative changes tend to appear promptly as the pressure fluctuates either way from the isotonic, and the higher the osmotic pressure the greater is this tendency. 5. The optimal pH of the medium for megakaryocytes is 7.63-7.92 in the case of human and 7.75-8.07 in the case of guinea pigs. 6. Of the media used separately such as physiological saline solution, serum, and Ringer's solution, for megakaryocytes Ringer's solution is most suitable followed by serum, but in the physiological saline solution the movement of megakaryocytes is completely inhibited, No potential conflict of interest relevant to this article was reported.

岡山医学会 Acta Medica Okayama 0030-1558 71 7-1 1959 細菌のグルコース酸化に対するCo(++), Ni(++), Zn(++)の影響 第2編 Co(++), Ni(++), Zn(++)添加培地発育菌の酵素的性状について 3681 3688 EN Masahiko Kitamura In order to investigate the inhibitory effects of Co(++), Ni(++) and Zn(++) on oxydation of glucose by Sh. flexneri and Staphy. albus, the author made a comparison between the enzymatic properties of the organisms that were cultured on the media containing these metal ions and that of control. The following results were obtained. 1) The oxydative ability for pyruvate and its related substances was considerably lower in the organism grown on inhibitor contained media than in in the control; the accumulated products from glucose metabolism, such as pyruvate, were abundant on the organism tested compaired with control; therefore it could be supposed that the further oxydation of pyruvate was not taken place so successfully. 2) The mechanism of the inhibition on the oxydation were supposed to be the same way in either metal ions tested. 3) It could not succeed to demonstrate the occurence of any changes in the way of glucose oxydation and the hydrogen transfer system of tested organisms. No potential conflict of interest relevant to this article was reported.

岡山医学会 Acta Medica Okayama 0030-1558 101 7-8 1989 Yersinia enterocoliticaの膜脂質解析および培養温度変換による適応変化 811 820 EN Sei-ichiro Shibuya The author studied the membrane lipid and fatty acid compositions of Yersinia enterocolitica. Furthermore, the author studied the adaptation of the membrane to changes in culture temperatures, and characterized the physical state of membrane lipid by nylon microcapsule method developed by Okahata and Nagamachi. Phosphatidylglycerol, phosphatidylethanolamine and cardiolipin were the main phospholipids of the membrane. The ratio of these phospholipid compositions was not changed by culture temperature. Fatty acids were found to be C(14:0), C(15:0), C(16:0), C(16:1), C(17:0), C(18:0), C(18:1) and cyclopropane C(17:0). The last was identified by gaschromatography-massspectrometry and hydrogenation. In 37°C cultures, saturated fatty acids were increased and unsaturated fatty acids were decreased in comparison with those from 25°C cultures. Cyclopropane C(17:0) was also increased in 37°C cultures. These changes appear to be necessary for maintaining membrane stability at high temperatures. Using NaCI-release from 0.2M NaCI-entrapped nylon microcapsules coated with the membrane lipids as an indicator, it was found that phase transition of lipid membranes from 25°C cultures and 37°C cultures occurred approximately at 30°C and 45°C, respectively. The differences in the phase transition temperature seem to correlate with the adaptive changes in fatty acid composition by culture temperatures. No potential conflict of interest relevant to this article was reported.

岡山大学温泉研究所 Acta Medica Okayama 0369-7142 13 1953 鳥取県三朝温泉に於ける二，三の放射性元素の存在について 5 8 EN Mitsuo Sato 10.18926/40342 The author tried to measure RaB, RaC and ThB in the hot spring waters using G-M counter and proved the existence of RaB and ThB in Misasa Hot Springs. To 100 liters of spring water ahout 20 gms of ferric chloride and then sodium hydroxide were added. Precipitate was dissolved in hydrochloric acid and after adding bismuth and lead, the solution was saturated with hydrogen sulfide. The precipitate of sulfides was filtered and ignited to ashes after drying. The β-activity of the ashes was measured by a mica-window type G-M counter with the recording circuits of scale of 16. Natural background was 50±5 connts per minutes. Six spring waters of Misasa, namely "Spring of Branch Laboratory", "Nakayu", "Gunze" "O-T-R", "Jwayu", and "Tsukiminoyu" were investigated. RaB was detected in all samples. ThB was found only in "Gunze" and "O-T-R". ThB content of "Gunze" was estimated, to be roughly 1×10(-12) Curie units per liter. No potential conflict of interest relevant to this article was reported.

岡山大学温泉研究所 Acta Medica Okayama 0369-7142 20 1958 鳥取県三朝温泉の温泉水中の二価鉄及び可還元鉄の密栓放置による濃度変化について 48 54 EN Shigeo Tanaka 10.18926/40272 The two sprigns called "Tanaka-no-Yu" and "Hisui-no-Yu" at Misasa Hot Springs, japan (Fig. 1), suitable for sampling the unpolluted water, the locations of which, are shown in Fig. 2, were chosen for this study. The o-phenanthroline method, details of which were discussed in the previous report by the author (Repts. Balneol. Lab. Okyama Univ., 17, 1, (1956)) was used for the determination of ferrous iron, ferrous iron + reducible iron, and ferrous iron + reducible iron + colloidally dispersed iron (to be referred to as "total irons" in this report). For comparison, the change in concentratin of iron dissolved in distilled water during preservation in a sealed bottle was observed, and the results obtained for the solutions with the pH values of 5.4 and 5.8 are illustrated in Fig.3 and Fig.5, rspectively. Both ferrous and reducible iron disappear within 5 minutes, when the pH of the solution is 6.4. The hydrogen ion concentration was thus seen to give a sensitive effects on the speed of diminution of ferrous and reducible iron dissolved in the distilled water. It should be noticed that no appreciable diminution was observed during the period from 60 min. to 120 min,. It is probable that the diminution of total iron is caused by the adsorption of colloidal iron hydroxides on the wall of glass bottle. The effects of charged anion (SO(4)(--)) on the change in concentration of iron during preservation was also investigated, but no appreciable effect was found. (Fig. 5 and Fig. 6). Fig.7, Fig.8, and Fig.9 show the change in concentration of iron during preservation of the spring water at "Tanaka-no-Yu". The content of iron in the spring water is about 0.3 mg/l, and its pH value is about 7.1. For the first 30 minutes, ferrous iron diminishes rapidly, the slope of the diminution curve being sharp and almost straight. Thereafter the slope becomes gentler, and, after an hour, the slope approaches nearly zero. On the other hand, ferrous iron dissolved in distilled water disappears in a moment at the same pH 7.1. Fig.10, Fig.11, and Fig.12 show the change in concentration of iron during preservation of the spring water at "Hisui-no-Yu". The content of iron in the spring water is about 1.0 mg/l, and its pH value is about 6.4. In this case, the diminution of ferrous iron is not remarkable, and only 20% of the initial quantity diminishes within 2 days. Whereas, in the case of distilled water, the diminution is very rapid at the same pH 6,4, and the ferrous iron disappears completely within 5 minutes. In Fig.13 the speed of diminution of iron in distilled water and that in spring water are compared. The difference here seen may probably be due either to that the ferrous iron in spring water is in a certain complex form not easily oxidizable, or to that the spring water contains some reducing substances. No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 143 4 2008 Selenite Assimilation into Formate Dehydrogenase H Depends on Thioredoxin Reductase in Escherichia coli 467 473 EN Muneaki Takahata Takashi Tamura Katsumasa Abe Hisaaki Mihara Suguru Kurokawa Yoshihiro Yamamoto Ryuhei Nakano Nobuyoshi Esaki Kenji Inagaki <p>Escherichia coli growing under anaerobic conditions produce H-2 and CO2 by the enzymatic cleavage of formate that is produced from pyruvate at the end of glycolysis. Selenium is an integral part of formate dehydrogenase H (FDHH), which catalyses the first step in the formate hydrogen lyase (FHL) system. The genes of FHL system are transcribed only under anaerobic conditions, in the presence of a sigma(54)-dependent transcriptional activator Fh1A that binds formate as an effector molecule. Although the formate addition to the nutrient media has been an established procedure for inducing high FDHH activity, we have identified a low-salt nutrient medium containing &#60;0.1% NaCl enabled constitutive, high expression of FDHH even without formate and D-glucose added to the medium. The novel conditions allowed us to study the effects of disrupting genes like trxB (thioredoxin reductase) or gor (glutathione reductase) on the production of FDHH activity and also reductive assimilation of selenite (SeO32-) into the selenoprotein. Despite the widely accepted hypothesis that selenite is reduced by glutathione reductase-dependent system, it was demonstrated that trxB gene was essential for FDHH production and for labelling the FDHH polypeptide with Se-75-selenite. Our present study reports for the first time the physiological involvement of thioredoxin reductase in the reductive assimilation of selenite in E. coli.</p> No potential conflict of interest relevant to this article was reported.

Blackwell Publishing Acta Medica Okayama 0108-2701 63 1 2007 Hydrogen bonding in two solid phases of phenazine-chloranilic acid (1/1) determined at 170 and 93 K o17 o20 EN Kazuma Gotoh Tetsuo Asaji Hiroyuki Ishida The crystal structures in two solid phases, i.e. phase II stable between 146 and 253 K and phase IV below 136 K, of the title compound [phenazine-chloranilic acid (1/1), C12H8N2 center dot C6H2Cl2O4, in phase II, and phenazinium hydrogen chloranilate, C12H9N2+center dot C6HCl2O4-, in phase IV], have been determined. Both phases crystallize in P2(1), and each structure was refined as an inversion twin. In phase II, the phenazine and chloranilic acid molecules are arranged alternately through two kinds of O-H center dot center dot center dot N hydrogen bonds. In phase IV, salt formation occurs by donation of one H atom from the chloranilic acid molecule to the phenazine molecule; the resulting monocation and monoanion are linked by N-H center dot center dot center dot O and O-H center dot center dot center dot N hydrogen bonds. No potential conflict of interest relevant to this article was reported.

Pergamon-Elsevier Science Ltd. Acta Medica Okayama 0968-0896 15 19 2007 Antitumor studies. Part 3: Design, synthesis, antitumor activity, and molecular docking study of novel 2-methylthio-, 2-amino-, and 2-(N-substituted amino)-10-alkyl-2-deoxo-5-deazaflavins 6336 6352 EN Hamed I. Ali Noriyuki Ashida Tomohisa Nagamatsu Various novel 10-alkyl-2-deoxo-2-methylthio-5-deazaflavins have been synthesized by reaction of 6-(N-alkylanilino)-2-methylthiopyrimidin-4(3H)-ones with Vilsmeier reagent. The similar 2-(N-substituted amino) derivatives were prepared by nucleophilic replacement reaction of the 2-methylthio moiety by appropriate amines. The 2-oxo derivatives (i.e., 5-deazaflavins) were obtained by acidic hydrolysis of the 2-methylthio derivatives. The antitumor activities against CCRF-HSB-2 and KB cells and the antiviral activities against HSV-1 and HSV-2 have been investigated in vitro, and many compounds showed promising antitumor activities. Furthermore, AutoDock molecular docking into PTK has been done for lead optimization of these compounds as potential PTK inhibitors. Whereas, the designed 2-deoxo-5-deazaflavins connected with amino acids at the 2-position exhibited the good binding affinities into PTK with more hydrogen bonds. No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 152 10 2005 Effect of annealing and hydrogen on properties of electrodeposited platinum electrode and lead-zirconate-titanate films for ferroelectric random access memory applications 688 691 EN Kazuo Kondo Keiji Watanabe Yuji Abe Junko Haji Masaru Shimizu <p>The selection of capacitor electrode materials for the nonvolatile ferroelectric random access memory is one of the most important issues because capacitor electrical characteristics are strongly influenced by the electrode materials. The lower Pt electrode was electrodeposited on the Ti seed/Pt seed layer. Two different thicknesses of Ti seed layer (5 and 15 nm) were adopted, and lead-zirconate-titanate (PZT) was deposited on the electrodeposited Pt. The Pt crystal orientation with a 5 nm Ti seed layer is much better than that with a 15 nm Ti seed layer, and the deposited PZT shows much better crystal orientation. Due to better crystal orientation of the PZT layer in the case of a 5 nm Ti seed layer, a Pt/PZT/Pt capacitor well-saturated D-V hysteresis loop was obtained whereas little current was observed in the large electric field. With the 15 nm Ti seed layer, numerous several-mu m-sized voids formed on the lower Pt electrode surface. With the 5 nm Ti seed layer, fewer voids formed on the lower Pt electrode surface. Glow discharge spectrometry measurement with a 15 nm Ti seed layer shows much higher H intensity than that with a 5 nm Ti seed layer, and the H peak coincides with the Ti peak. The H existing in the Ti seed layer must have transmitted into the PZT layer and deteriorated the PZT crystal orientation. (c) 2005 The Electrochemical Society. </p> No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 34 10 2005 Polar and hydrogen-bonding effects of alcohols on the emission spectrum of styrene-triethylamine system 1109 1119 EN Shunzo Yamamoto <p>The emission spectra of styrene (ST)-triethylamine (TEA) systems were measured under steady-state illumination conditions in some THF-protic solvent mixtures. The fluorescence spectrum of the ST-TEA system in THF consists of two bands (band A at 304 nm (fluorescence of ST) and band B at 460 nm (emission from an exciplex)). The intensity of band A increased and that of band B decreased with increasing amounts of protic solvents in THF-protic solvent mixtures. The increase in the intensity of band A was explained by the decrease in the concentration of free amine owing to the hydrogen-bonding interaction (or protonation) between TEA and protic solvents. The decrease in the intensity of band B was considered to be caused by the decrease in the concentration of free amine on the addition of protic solvents and the enhanced conversion of the exciplex to an ion pair with increasing solvent polarity. The polar effect was expressed as a function of the relative permittivity of the solution.</p> No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 123 11 2005 Infrared spectra of seeded hydrogen clusters: (para-H2)N-N2O and (ortho-H2)N-N2O, N=2-13 EN Jian Tang Robert A McKellar <p>High-resolution infrared spectra of clusters containing para-H2 and/or ortho-H2 and a single nitrous oxide molecule are studied in the 2225-cm–1 region of the 1 fundamental band of N2O. The clusters are formed in pulsed supersonic jet expansions from a cooled nozzle and probed using a tunable infrared diode laser spectrometer. The simple symmetric rotor-type spectra generally show no resolved K structure, with prominent Q-branch features for ortho-H2 but not para-H2 clusters. The observed vibrational shifts and rotational constants are reported. There is no obvious indication of superfluid effects for para-H2 clusters up to N=13. Sharp transitions due to even larger clusters are observed, but no definite assignments are possible. Mixed (para-H2)N–(ortho-H2)M–N2O cluster line positions can be well predicted by linear interpolation between the corresponding transitions of the pure clusters.</p> No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 401 2008 Formation of low-resistivity region in p-Si substrate of SiGe/Si episystem by remote-hydrogen plasma treatment 218 221 EN Yoshifumi Yamashita Yoshifumi Sakamoto Yoichi Kamiura Takeshi Ishiyama <p>We have studied effects of hydrogen treatment on the resistivity profile of the SiGe/Si episystem by spreading resistance (SR) method. In this paper, we present experimental findings that hydrogen treatment reduces the resistivity at a specific part in the Si substrate region. This position was confirmed to be under the interface between SiGe and Si that emerged on the bevel surface during hydrogen treatment. We investigated the depth of resistivity-reduced regions which was formed by various hydrogenating conditions and found that the region was extended to the same depth as the penetration depth of hydrogen. We concluded that the low-resistivity region was formed under the influence of hydrogen introduced from bevel surface. We attributed this resistivity reduction to formation of some defects which originally existed at the interface and diffused into Si substrate with hydrogen.</p> No potential conflict of interest relevant to this article was reported.

American Institute of Physics Acta Medica Okayama 122 10 2005 Phase diagram of water between hydrophobic surfaces EN Kenichiro Koga Hideki Tanaka Molecular dynamics simulations demonstrate that there are at least two classes of quasi-two-dimensional solid water into which liquid water confined between hydrophobic surfaces freezes spontaneously and whose hydrogen-bond networks are as fully connected as those of bulk ice. One of them is the monolayer ice and the other is the bilayer solid which takes either a crystalline or an amorphous form. Here we present the phase transformations among liquid, bilayer amorphous (or crystalline) ice, and monolayer ice phases at various thermodynamic conditions, then determine curves of melting, freezing, and solid-solid structural change on the isostress planes where temperature and intersurface distance are variable, and finally we propose a phase diagram of the confined water in the temperature-pressure-distance space. No potential conflict of interest relevant to this article was reported.

American Institute of Physics Acta Medica Okayama 0021-9606 127 4 2007 On the thermodynamic stability of hydrogen clathrate hydrates EN Keisuke Katsumasa Kenichiro Koga Hideki Tanaka The cage occupancy of hydrogen clathrate hydrate has been examined by grand canonical Monte Carlo (GCMC) simulations for wide ranges of temperature and pressure. The simulations are carried out with a fixed number of water molecules and a fixed chemical potential of the guest species so that hydrogen molecules can be created or annihilated in the clathrate. Two types of the GCMC simulations are performed; in one the volume of the clathrate is fixed and in the other it is allowed to adjust itself under a preset pressure so as to take account of compression by a hydrostatic pressure and expansion due to multiple cage occupancy. It is found that the smaller cage in structure II is practically incapable of accommodating more than a single guest molecule even at pressures as high as 500 MPa, which agrees with the recent experimental investigations. The larger cage is found to encapsulate at most 4 hydrogen molecules, but its occupancy is dependent significantly on the pressure of hydrogen. No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 133 2 2008 Analysis of response mechanism of a proton-pumping gate FET hydrogen gas sensor in air 538 542 EN Tomiharu Yamaguchi Masanori Takisawa Toshihiko Kiwa Hironobu Yamada Keiji Tsukada <p>Two different types of hydrogen response signals (DC and AC) of a proton-pumping gate FET with triple layer gate structure (Pd/proton conducting polymer/Pt) were obtained. The proton-pumping gate FET showed good selectivity against other gases (CH₄, C₂H₆, NH₃, and O₂). For practical use, the hydrogen response characteristics of the proton-pumping gate FET were investigated in air (a gaseous mixture of oxygen and nitrogen). The proton-pumping gate FET showed different hydrogen response characteristics in nitrogen as well as in air, despite the lack of oxygen interference independently. To clarify the response mechanism of the proton-pumping gate FET, a hydrogen response measurement was performed, using a gas flow system and electrochemical impedance spectroscopy. Consequently, the difference in response between nitrogen and air was found to be due to the hydrogen dissociation reaction and the interference with the proton transfer caused by the adsorbed oxygen on the upper Pd gate electrode</p> No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 68 3 2005 Kinetic-spectrophotometric method for the determination of trace amounts of bromide in seawater 951 956 EN Kanchana Uraisin Toshio Takayanagi Mitsuko Oshima Duangjai Nacapricha Shoji Motomizu <p>A novel simple, sensitive and rapid kinetic-spectrophotornetric method is proposed for the determination of trace amounts of bromide. The method is based on its catalytic effect on the oxidation of methylene blue (MB) by hydrogen peroxide in strongly acidic solution. The oxidation reaction is activated by large amounts of chloride and can be monitored spectrophotometrically by measuring the decrease in the absorbance of MB at 746 run. The determination of bromide is performed by a fixed-time method at the first 100 s from the initiation of the reaction. Unlike other kinetic-spectrophotornetric methods for the determination of bromide, the proposed method does not require heating the solution. Bromide can be determined in the range from 80 to 960 mu g l(-1) with the detection limit of 35 mu g l(-1). The relative standard deviation of ten replicate determination of 480 mu g l(-1) bromide was 1.4%. The influence of potential interfering ions was studied. The proposed method was satisfactorily applied to the determination of bromide in seawater without interfering effect from chloride ion.</p> No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 68 2 2005 Determination of trace amounts of bromide by flow injection/stopped-flow detection technique using kinetic-spectrophotometric method 274 280 EN K. Uraisin D. Nacapricha S. Lapanantnoppakhun K. Grudpan Shoji Motomizu <p>A simple, sensitive and selective method for the determination of bromide in seawater by using a flow injection/stopped-flow detection technique was examined. The detection system was developed for a new kinetic-spectrophotometric determination of bromide in the presence of chloride matrix without any extraction and/or separation. The detection was based on the kinetic effect of bromide on the oxidation of methylene blue (MB) with hydrogen peroxide in a strongly acidic solution. Large amounts of chloride could enhance the sensitivity of the method as an activator. The decolorisation of the blue color of MB was used for the spectrophotometric determination of bromide at 746 nm. A stopped-flow approach was used to improve the sensitivity of the measurement and provide good linearity of the calibration over the range of 0-3.2 p,g ml(-1) of bromide. The relative standard deviation was 0.74% for the determination of 2.4 jig ml(-1) bromide (n=5). The detection limit (3 sigma) was 0.1 mu g ml(-1) with a sampling frequency of 12 h(-1). The influence of potential interfering ions was studied. The proposed method was applied to the determination of bromide in seawater samples and provided satisfactory results. </p> No potential conflict of interest relevant to this article was reported.

The Japan Society for Analytical Chemistry Acta Medica Okayama 0910-6340 21 3 2005 Trace and ultratrace analysis of purified water samples and hydrogen peroxide solutions for phosphorus by flow-injection method 263 268 EN Zenhai Li Mitsuko Oshima Akhmad Sabarudin Shoji Motomizu <p>A highly sensitive fluorescence-quenching method for the determination of phosphorus based on the formation of an ion associate between molybdophosphate and Rhodamine B (RB) was developed. A simple flow-injection system coupled with a fluorescence detector was used to measure the fluorescence intensity at 560 nm and 580 nm as an excitation and an emission wavelength, respectively. The calibration graph for phosphorus showed a good linearity in the range of (0-1) x 10(-7) M (1 M = 1 mol L-1), and a detection limit of I x 10(-9) M (SIN = 3). The proposed method was successfully applied to the determination of ultratrace amounts of phosphorus in ultrapurified and purified water samples, and to the determination of trace amounts of phosphorus in commercially-available hydrogen peroxide solutions with satisfactory results. No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 126 8 2005 Intermolecular-medium and intramolecular-weak hydrogen bonding chains in the crystals of chiral trifluoromethylated amino alcohols 1134 1139 EN Toshimasa Katagiri Yasuyuki Fujiwara Satoshi Takahashi Kenji Uneyama <p>A structural feature of hydrogen bonding chains found in the crystals of trifluoromethylated amino alcohols is reported. Hydrogen bondings of 3-(N,N-dialkylamino)-1,1,1-trifluoro-2-propanols construct chiral spiral hydrogen bonding chains. Lone pairs on the nitrogen atoms of the amino alcohols participate in two hydrogen bondings. Detailed structural analysis of the hydrogen bonds of the 3-(N,N-dimethylamino)-1,1,1-trifluoro-2-propanol suggested that the chain built up with alternating intermolecular medium and intramolecular weak hydrogen bonds. The medium intermolecular hydrogen bond, which transfers a proton from the hydroxy group to the amino nitrogen, would make a tentative zwitterionic form of the molecule. Then, electrostatic attraction between the charges in the zwitterion centers induced a weak intramolecular hydrogen bond.</p> No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 162 1 2004 Separation into polar and hydrogen-bonding factors of the effects of alcohols on the emission spectrum of 4-phenyl-1-N,N-dimethylaminobutane in THF 73 79 EN Xie Guobin Mayuko Nakamura Yoshimi Sueishi Shunzo Yamamoto <p>The effects of the additions of protic and aprotic polar solvents on the emission spectrum of 4-phenyl-1-N,N-dimethylaminobutane (PDAB) in THF have been studied under conditions of steady-state illumination. The fluorescence spectrum of PDAB in THF was reported to consist of three component bands (band A at 285 nm (fluorescence of the phenyl group), band B at 343 nm (fluorescence of the amino group) and band C at 385 nm (emission from an intramolecular exciplex)). The intensities of bands B and C decreased with increasing solvent polarity. They also decreased owing to the hydrogen-bonding interaction between the amino group in PDAB and protic solvents, but in this case the intensity of band A was found to increase. Acetonitrile has only a polar effect and trichloroacetic acid only a hydrogen-bonding (or protonation) effect, while alcohols have both effects. The equilibrium constants for the formation of intermolecular hydrogen-bonded complexes of the amino group with alcohols were estimated from the intensity change of band A. The hydrogen-bonding and polar effects of alcohols on the intensities of bands B and C could be separately evaluated. The decrease in the intensities of bands B and C with increasing solvent polarity in THF-AN and THF-alcohol mixtures is considered to be caused by the conversion of the exciplex to an ion-pair enhanced by the increase in solvent polarity.</p> No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 162 2-3 2004 Effects of alcohols on emission spectra of toluene-triethylamine mixtures in THF: separation into polar and hydrogen-bonding interactions 449 456 EN Guobin Xie Yoshimi Sueishi Shunzo Yamamoto <p>The emission spectra of toluene (T)–triethylamine (TEA) systems were measured under conditions of steady-state illumination in some protic and aprotic solvent–THF mixtures. The fluorescence spectrum of the T–TEA system in THF could be separated into three component bands (band A at 279 nm (fluorescence of T), band B at 336 nm (fluorescence of TEA) and band C at 373 nm (emission from an intermolecular exciplex)). The intensities of bands B and C decreased with increasing solvent polarity. The decrease in the intensities of bands B and C is considered to be caused by the enhanced conversion of the exciplex to an ion-pair with increase in solvent polarity. The intensities of bands B and C also decreased owing to the hydrogen-bonding interaction between TEA and protic solvents, but in this case the intensity of band A increased. Acetonitrile only has a polar effect and trichloroacetic acid only has a hydrogen-bonding (or protonation) effect, while alcohols have both effects. The equilibrium constants for the formation of intermolecular hydrogen-bonded complexes of TEA with alcohols were estimated from the changes in the intensity of band A. The hydrogen-bonding and polar effects of alcohols on the intensities of bands B and C could be evaluated separately. The ratio of the hydrogen-bonding effect to the polar effect of alcohols was observed to increase with increasing vol.% of alcohol.</p> No potential conflict of interest relevant to this article was reported.

Okayama University Medical School Acta Medica Okayama 24 6 1970 Vaccination with complete adjuvant-added inactivated virus vaccine of Japanese encephalitis to swine for preventing viremia (with specific reference to the effect of vaccination on viremia; epidemiological study on Japanese encephalitis. 35) 579 587 EN Masana Ogata Yutaka Nagao Fumihiko Jitsunari Ritsuko Kikui Naoji Kitamura Article 10.18926/AMO/32766 <p>As to trial toward the elimination of Japanese encephalitis virus in natural surroundings, pigs received inoculation of inactivated Japanese encephalitis vaccine supplemented with complete Freund's adjuvant twice at one-week interval. Effect of adjuvant supplement on the magnitude of antibody and also prevention of viremia caused by natural infection by antibody induced with vaccine were investigated. The results of this study are summarized as follows. 1. In the group of pigs inoculated with vaccine containing adjuvant, titer of hemoagglutination inhibiting and neutralizing antibodies was higher than those inoculated with vaccine alone and their high titer persisted. 2. With respect to natural infection of pigs, on August 22 when the pigs were thought to have been infected, there was observed a rise in antibody titers. And on antibody formed in those pigs inoculated with vaccine with or without adjuvant proved to be all 2-ME resistant type, whereas the antibodies produced in control group were 2-ME sensitive antibody. 3. Viremia was detected in the blood of pigs naturally infected, but it was not demonstrated pigs inoculated with vaccine supplemented with adjuvant or without adjuvant. The virus of pig blood which was inoculated into suckling mouse brain and was separated after low suckling passage mouse was supposed to be JaGAr strain from optimum hydrogen ion concentration of its hemoagglutination reaction. 4. Effect of vaccination on antibody response of pigs having maternal antibody was not recognized.</p> No potential conflict of interest relevant to this article was reported.

Okayama University Medical School Acta Medica Okayama 20 5 1966 Nature of cultured cells of the skin from acatalasemic individuals with Takahara's disease 193 202 EN Masanori Sadamoto Article 10.18926/AMO/32741 <p>For the purpose to clarify whether minimal catalatic activity exists in Japanese acatalasemic cells or not and the manner how extrinsic hydrogen peroxide affects the acatalasemic cells, the author performed tissue cultures using the skin specimens from four acatalasemic persons affected with Takahara's disease and studied the nature of these cultured cells. The results are summarized as follows. 1. Between normal and acatalasemic cultured cells, no morphological differences could be seen and the growth rate of these cell-lines was similar to one another. 2. On the activity of succinoxidase and cytochrome oxidase there could be observed no difference between normal and acatalasemic cells. 3. In each acatalasemic cell line the minimal catalatic activity was observed and it seemed that this activity has an important role in decomposing hydrogen peroxide under normal metabolic pathway. 4. After treating with 10-4M hydrogen peroxide, respiratory enzyme activities and the growth rate in the acatalasemic cells were markedly disturbed, while in normal cells these remained almost intact. 5. There could be observed no differences between normal and acatalasemic cultured cells after X-ray irradiation (200 to 600 r) on the succinoxidase activity, catalatic activity and growth rate.</p> No potential conflict of interest relevant to this article was reported.

Okayama University Medical School Acta Medica Okayama 17 5 1963 The effect of oxygen tension on tetrazolium reduction by respiratory enzyme systems of tissue culture cells 221 230 EN Iwao Matsuoka Takuzo Oda Satimaru Seno Article 10.18926/AMO/32604 <p>1. Attempts have been made to confirm how the formazan formation is affected in the presence of oxygen gas when the cells are incubated with neotetrazolium salt and the subsrtates for the enzymes to be tested. 2. In the cases of succinoxidase formazan formation is minimized under pure O2tension, it increases with decrease in O2 tension, and reaches its maximum value under N2gas. 3. This relationship between the oxygen tension and the diformazan formmation can likewise be observed even after pretreatment of the system with KCN. 4. In measuring enzyme activity of the DPN-diaphorase system with L-glutamate and DPN as substrate and NT as hydrogen acceptor, the same relationships between the oxygen tension and the NT-reduction can be seen as in succinoxidase system. 5. In the determination of enzyme activity of the cytochrome-c-cytochrome oxidase system with p-phenylene-diamine as substrate and NT as hydrogen acceptor, likewise the diformazan formation is markedly affected by oxygen tension and increased with the reduced oxygen tension but under pure Ns gas the value is reduced. When the systen is pretreated with KCN, however, the diformazan formation reveals its maximum value under pure nitrogen gas, the values of which correspond to those values of endogenous reaction without substrate. 6. The above results show that the neotetrazolium salt can compete with O2 as hydrogen acceptor, and less values of formazan formation may be obtained under higher oxygen tension and the higher values under lower oxygen tension independently from the true activity of the enzyme.</p> No potential conflict of interest relevant to this article was reported.

Okayama University Medical School Acta Medica Okayama 23 6 1969 Catalase activity in the red cell ghost of hypocatalasemia and normal subject. II. Isolation of catalase in the red cell ghost by electrophoresis 553 558 EN Keiko Nisioka Article 10.18926/AMO/32531 <p>For the purpose to clarify further the residual catalase in the blood cell ghost, the ghost has been applied to Cyanogum and starch block electrophoresis and the results are briefly summarized as follows. 1. It has been demonstrated that after Cyanogum electrophoresis of the ghost after several washings, bubbling due to enzymatic reaction of catalase occurs near the points of origin, when the plate is immersed in hydrogen peroxide solution and also it has been proved the presence of catalase so firmly bound to the ghost that it is hardly moved by the electro phoresis. Even with the ghost of hypocatlasemia there can be detected catalase which is likewise hardly eluted from the ghost. 2. In the estimation of catalase activities of each fraction from red cell ghost by starch block electrophoresis there can be detected catalase near the point of origin, that is not eluted by the electrophoresis, and the activity of which corresponds to about 0.1 % of the total red cell catalase activity.</p> No potential conflict of interest relevant to this article was reported.

Okayama University Medical School Acta Medica Okayama 0386-300X 54 6 2000 Immunophilin ligands prevent H2O2-induced apoptotic cell death by increasing glutathione levels in neuro 2A neuroblastoma cells. 275 280 EN Ken-ichi Tanaka Naoko Fujita Masato Asanuma Norio Ogawa Article 10.18926/AMO/32278 <p>We examined the effects of FK506 and its non-immunosuppressive derivative, GPI1046, on H2O2-induced reduction of cell viability and apoptotic cell death in Neuro 2A cells. Our results suggest that the protective properties of GPI1046 against H2O2-induced reduction of cell viability are equipotent with those of FK506 and may be mediated by increased intracellular concentrations of glutathione (GSH). In addition, both FK506 and GPI1046 prevented apoptotic cell death in Neuro 2A cells, although the antiapoptotic effect of FK506 was somewhat stronger than that of GPI1046. These findings suggest that non-immunosuppressive immunophilin ligands such as GPI1046 might be potentially useful in treatment of neurodegenerative diseases without serious side effects such as immune deficiency.</p> No potential conflict of interest relevant to this article was reported.

Okayama University Medical School Acta Medica Okayama 0386-300X 41 5 1987 Radioprotective effects of thiomethylhydantoin derivatives on Escherichia coli and mice. 187 193 EN Akihisa Nishimura Kaname Aono Article 10.18926/AMO/31755 <p>Protection of Escherichia coli NIHJ and C57BL mice from the effects of 60Co gamma-rays provided by S-alk(en)yl-L-cysteines and their hydantoin derivatives was examined. E. coli (10(6) cells/ml) suspended in a 20 mM aqueous solution of one of the drugs was irradiated with 60 Gy of gamma-rays. Five week-old male mice were exposed to 5.0-9.5 Gy of gamma-rays after a single intraperitoneal injection of 0.75 mmol/kg body weight of each compound. In both E. coli and mice, S-allyl compounds afforded more effective radioprotection than S-propyl compounds. The replacement of the alpha-hydrogen of S-substituted cysteines by methyl groups decreased the radioprotective effect. Hydantoin derivatives were much more radioprotective than the original sulfur-containing amino acids. Especially, DL-5-allylthiomethyl-5-methylhydantoin had a remarkable radioprotective effect in mice. The gamma-radiolysis mechanism of thiomethylhydantoin derivatives was discussed in connection with the radioprotective effect of the drugs.</p> No potential conflict of interest relevant to this article was reported.

Okayama University Medical School Acta Medica Okayama 0386-300X 53 6 1999 Erythrocyte susceptibility to lipid peroxidation in patients with coronary atherosclerosis. 259 264 EN Yildiz Dincer Tulay Akcay Dildar Konukoglu Husrev Hatemi Article 10.18926/AMO/31620 <p>In recent years it has been reported that free oxygen radicals play an important role in the pathogenesis of degenerative diseases and that antioxidant vitamins such as vitamins E or C prevent their harmful effects. In this study, we evaluated the following: Erythrocyte susceptibility to lipid peroxidation; the role of erythrocyte glutathione (GSH) as an antioxidant; plasma lipid fractions; and the relationship between plasma lipid peroxides and antioxidant vitamin levels. Thiobarbituric acid-reactive substance (TBARS) levels were measured to determine the levels of plasma lipid peroxides and the susceptibility to lipid peroxidation when erythrocytes were stressed by hydrogen peroxide for 2 h in vitro. Erythrocyte TBARS production was significantly higher in patients with coronary atherosclerosis than in the controls. On the other hand, the levels of plasma high-density lipoproteins, vitamin C, vitamin E and erythrocyte GSH were significantly lower, and the levels of plasma total cholesterol, triglycerides, low-density lipoproteins and TBARS were significantly higher in the patients with coronary atherosclerosis than in the controls. In conclusion, our results indicate that erythrocytes from patients with coronary atherosclerosis are more susceptible to oxidation than those of controls and that these patients have lowered antioxidant capacity as revealed by decreased plasma levels of vitamins C and E.</p> No potential conflict of interest relevant to this article was reported.

Okayama University Medical School Acta Medica Okayama 0386-300X 52 5 1998 Determination of glutathione peroxidase activity and its contribution to hydrogen peroxide removal in erythrocytes. 233 237 EN Masahiro Wakimoto Noriyoshi Masuoka Taku Nakano Toshihiko Ubuka Article 10.18926/AMO/31323 <p>A new method for the determination of glutathione peroxidase activity in erythrocytes was developed. The present method was applied to the measurement of hydrogen peroxide removal rates by glutathione peroxidase in erythrocytes at 70 microM hydrogen peroxide under simulated in vivo conditions. The removal rates by glutathione peroxidase in mouse erythrocytes were twenty-times faster than those in human ones and were 5.2 mumol/sec/g of Hb. The removal rates in acatalasemic mouse erythrocytes indicate that glutathione peroxidase is the main means of hydrogen peroxide removal in acatalasemic mouse erythrocytes. Based on these results, we concluded that glutathione peroxidase in mouse erythrocytes had sufficient ability to remove hydrogen peroxide at even relatively high concentrations. This may be one of the reasons why acatalasemic mice suffer no health problems while Japanese acatalasemic patients suffer from Takahara disease when infected with hydrogen peroxide-generating bacteria.</p> No potential conflict of interest relevant to this article was reported.

Okayama University Medical School Acta Medica Okayama 0386-300X 35 3 1981 Generation of superoxide and hydrogen peroxide during interaction of nitrite with human hemoglobin. 173 178 EN Shinsaku Watanabe Masana Ogata Article 10.18926/AMO/31285 <p>Generation of superoxide and hydrogen peroxide during interaction of nitrite with human hemoglobin was detected by chemiluminescence of luminol. Luminol chemiluminescence was inhibited by the addition of superoxide dismutase (SOD) and catalase. Methemoglobin formation induced by nitrite was also inhibited by the addition of SOD and catalase. The mechanism of methemoglobin formation by nitrite was discussed in regard to the oxidation of hemoglobin by superoxide and hydrogen peroxide as generated by the interaction of nitrite with hemoglobin.</p> No potential conflict of interest relevant to this article was reported.

Okayama University Medical School Acta Medica Okayama 13 3 1959 Statistical study of aca-talasemia, a review of thirty-eight cases appearing in the literatures 209 219 EN Shigeo Takahara Yoshio Ogura Katsusaburo Doi Article 10.18926/AMO/31238 <p>1. With a view to grasp more simply and clearly the characteristics of this disease and in order to find a clue for prompt discovery of cases when encountered in future, the authors undertook a statistical study of the cases already reported by various authors. 2. The cases reported so far amount to 17 familial groups which consisted of 38 acatalasemic cases. These groups were distributed widely throughout Japan. The disease seemed to be prevalent in the rural communities where adherence to the custom of consanguineous marriage occurs. As yet, we have not heard of the occurrence of this disease in other countries. 3. The disease has equal distribution in both sexes. About one half of patients showed a peculiar oral gangrene (Takahara's disease). The great majority of these were noted in those less than 10 years of age. 4. The great majority of them were children whose parents were united in consanguineous marriage and have siblings with acatalasemia. 5. As for the treatment of oral lesions in this disease, extraction of tooth at the site of the lesions, removal of the diseased tissues en masse by resection, and penicillin treatment given concomitantly are effective. The course and the length of time required in healing of the wound due to the operation are about the same as in the case of normal persons. 6. The authors wish to call special attention to the phenomenon peculiar to the acatalasemic blood. The blood of acatalasemic individuals changes to brownish-black color in the absence of foaming or bubble formation upon the application of hydrogen peroxide to blood.</p> No potential conflict of interest relevant to this article was reported.

Okayama University Medical School Acta Medica Okayama 0386-300X 49 2 1995 Measurement of hepatic blood flow using 111In colloid. 91 95 EN Shuichi Sakumoto Keisuke Hamazaki Hisashi Mimura Kunzo Orita Article 10.18926/AMO/30395 <p>The reduced hepatic blood flow calculated from hepatic scintigram with 198Au colloid was elucidated as the primary responsible factor for postoperative hepatic insufficiency. However 198Au colloid is no longer in use because of the high levels of radiation. Although 99mTc-phytate behaves similarly to 198Au on imaging, there were discrepancies between the hepatic blood flow index (KL) value and the severity of cirrhosis determined by laboratory data or by histology. In the measurement of hepatic blood flow using a radioactive colloid, factors like organ distribution, stability and uniformity of the colloid particles influence the values. In the present study, a 111In colloid was prepared and administered to rats to investigate the usefulness: as much as 95.4 (0.8) [Mean (+/- SD)]% of the colloid accumulated in the liver at pH 6.8. The distribution of particle diameter was within a relatively narrow range with the peak at 0.2 to 0.4 microns. Moreover, the KL values were not affected by condition of the reticuloendothelial system. The values showed a significant correlation with the measurements of the hepatic tissue blood flow obtained by the hydrogen gas clearance method (gamma = 0.83, P &#60; 0.001). Thus, the 111In colloid can be clinically used as a substitute for 198Au colloid in the preoperative examination for estimation of the limit of resection.</p> No potential conflict of interest relevant to this article was reported.

岡山大学温泉研究所 Acta Medica Okayama 0369-7142 43 1974 有馬地域の温泉,鉱泉の水素と酸素の同位体比について 15 28 EN Osamu Matsubaya Hitoshi Sakai Michiji Tsurumaki 10.18926/21205 Saline waters of thermal and mineral springs in Arima area, at Takarazuka, and in Ishibotoke area of Kawachinagano City indicate wide ranges of δD and δ(18)O values (Table 1). Excellent linearity exists between the δD and δ(18)O values (Fig. 1) and between the δ(18)O value and the chloride concentration (Fig. 2). These facts as well as the chemical evidence of the previous investigators strongly support the view that Arima springs are admixtures of a single deep brine and local ground water (TSURUMAKI, 1964). The deep brine may have the δ(18)O value of +8.0〜+8.5‰, the δD value of -25〜-30‰, and the chloride concentration of 1.20〜1.25 eq/l, which were estimated from the water of the maximum salinity so far reported. Because the thermal and mineral springs in Arima area closely associate with the upper Cretaceous granitic rocks, and the estimated δ(18)O value of the deep brine is similar to a value of water in isotopic equilibrium with those granitic rocks at 500〜600℃, the deep brine of Arima might have been the magmatic water of those granitic rocks. The mineral springs at Takarazuka and in Ishibotoke area also show the similar linearity among Cl(-), δ(18)O and δD to those in Arima area. Therefore it is assumed that the mineral springs at Takarazuka may be of the same origin as that in Arima area, and the mineral springs in Ishibotoke area might have been the fluid associated with Ryoke metamorphic rocks. Alternatively, the deep brine in Arima area may be isotopically and chemically similar to the saline formation waters in Illinois basin (GRAF et al., 1966). The high δD values and salinities of those formation waters were attributed to the isotopic and chemical fractionation during the passage of water through sediments. The deep brine in Arima area may be genetically similar to those saline formation waters. If such a saline water could have formed in Osaka basin, it is not surprising to find out the similar brines at Arima and Ishibotoke which are the northwestern and southeastern rims of the basin, respectively. At the present, it cannot be answered which of these two models is more probable. Further studies on other saline springs fluid inclusions of Cretaceous granitic rocks may be useful in order to solve this problem. No potential conflict of interest relevant to this article was reported.

岡山大学温泉研究所 Acta Medica Okayama 0369-7142 47 1978 北海道の温泉ならびに火山についての同位体化学的調査報告 55 67 EN Osamu Matsubaya Hitoshi Sakai Akira Ueda Makoto Tsutsumi Minoru Kusakabe Akira Sasaki 10.18926/21194 Stable isotope ratios of hydrogen, oxygen, carbon and sulfur of precipitation, thermal and mineral waters, and volcanic gases were measured. The isotopic data combined with chemical and geological information were discussed in terms of origin and evolution of the hotsprings and volcanic gases. The hotsprings along the Uchiura Bay, Oshima Peninsula are mostly near-neutral NaCl-type thermal water and may be divided into three groups : (1) thermal waters isotopically similar to the precipitation of this area, (2) those similar in D/H to the local meteoric waters but enriched by 2 to 3‰ in (18)O compared to the latter, and (3) those enriched significantly in both D and (18)O relative to the local meteoric waters. The first and second types of thermal water probably form from local meteoric water which percolates through "Green Tuff" formations and acquires dissolved chemicals from them. However, high salt concentration and the oxygen isotope shift (thesecond type) may imply that the NaCl-type water of volcanic origin might be involved. On the other hand, the waters of the third group can be explained by mixing of modern sea water into the second type thermal water (in case of Yachigashira) or by incorporation of fossil sea water of Tertiary origin into modern meteoric water (Nigorigawa). Except for Esan, Noboribetsu and Atosanupuri volcanic systems, waters from all the hotsprings and volcanic fumaroles associated with Quaternary volcanic rocks are meteoric in origin. Thermal waters at Esan, Noboribetsu and Atosanupuri have δD = -30〜-50 and δ(18)O = -1〜+ 3‰ and are enriched in D and (18)O relative to local meteoric water of the respective area. The origin of these waters and the mechanism (s) controlling the isotope ratios could not be made clear by the present study. Interesting is the finding that at Esan, Noboribetsu and Atosanupuri, thermal waters are enriched in D and (18)O relative to near-by fumarolic gases. The enrichment factor is 18 to 26‰ for hydrogen and 4 to 6‰ for oxygen, implying that more than one stages of liquidvapor separation are taking place in underground hydrothermal systems. No potential conflict of interest relevant to this article was reported.

岡山大学温泉研究所 Acta Medica Okayama 0369-7142 50 1980 長野県の温泉についての同位体化学的調査報告 17 24 EN Osamu Matsubaya Hitoshi Sakai Minoru Kusakabe Akira Sasaki 10.18926/21159 Water samples from 28 hotsprings and mineral springs in Nagano Prefecture, central Japan, were examined for their stable isotope ratios of hydrogen, oxygen, carbon, and sulfur. Spring waters of Kashio are highly saline and enriched in heavy isotopes of oxygen and hydrogen (δ(18)O=-2.5〜-4.6‰, δD=-54〜-57‰). Linear relationships among δD, δ(18)O, and Cl(-) suggest that spring waters are the mixtures of a deep brine and local surface water. Extrapolation of the linear relationships indicates that the deep brine is both isotopically and chemically very similar to the deep brine previously suggested for the springs of Arima, Takarazuka, and Ishibotoke of which δD, δ(18)O, and Cl(-) are estimated as -33‰, +8.0‰, and 44g/l, respectively. A common origin may be warranted among these postulated brines, while their provenance is yet to be worked out. The hot springs in Matsushiro are a Na-Ca-Cl type of high carbonate content. Their hydrogen and oxygen isotope ratios (δD=-71〜-46‰, δ(18)O=-9.1〜-2.0‰) are higher than the local surface water. On the basis of the relationships among δD, δ(18)O, and Cl(-), they are considered to be the mixtures of fossil sea water and certain water of meteoric origin of which Cl(-) is about 4g/l and δ(18)O is higher by about 3‰ than the local surface water. The latter may be meteoric water circulating in the marine sedimentary formations (Green Tuff formations) with soluble sea salts. Isotopic exchange with carbonate minerals in the formations explains its (18)O enrichment. Spring waters from Yashio and Isobe (Gunma Pref.) as well as Yunosawa and Yatate (Akita Pref.) were previously interpreted to be mixtures of fossil sea water and local surface water of low Cl(-) content. Re-examination of their data revealed that the meteoric waters responsible for these springs contain about 3g/l Cl(-), similar to the value obtained for Matsushiro. However, unlike Matsushiro, the meteoric waters in these areas are found to be isotopically similar to the local surface waters. Waters from other hot springs studied here are of simply meteoric origin, thus belonging to the GreenTuff type water previously defined. No potential conflict of interest relevant to this article was reported.

岡山大学温泉研究所 Acta Medica Okayama 0369-7142 50 1980 400℃, 1000気圧の熱水中におけるSO(2-)(4)-H(2)S間のイオウ同位体交換反応の実験的研究 1 15 EN Emi Kamada Hitoshi Sakai Noriaki Kishima 10.18926/21158 Experimental procedures used in this study are the same as those developed by Sakai and Dickson (1978). 0.005 M Na(2)S(2)O(3) solutions were heated to 400℃ under 1000 bar water pressure in a gold bag of Dickson gold-bag equipment (Fig. 1). At an elevated temperature Na(2)S(2)O(3) quickly and completely decomposed into 1:1 mixture of SO(4)(2-) and H(2)S (eq. (1)) and subsequent isotope exchange (eq. (2)) was monitored by consecutively withdrawing aliquots of solution for chemical and isotopic analyses at desired time intervals. For the preparation of SO(2) for isotope analyses, 2 to 5 mg BaSO(4) was thoroughly mixed with silica glass powder of 10 times the BaSO(4) in weight and heated to 1400℃ or so in sealed, evacuated silica glass tubings (see Fig. 2 and equation (4)). The technique is a modification of Holt and Engelkemeir (1971). The (18)O/(16)O ratios of SO(2) thus formed stayed constant by exchange with silica glass powder (Fig. 3). Numerical data of the three runs performed in this study are summarized in Tables 1 to 3. In runs 2 and 3, a small aliquot of (34)S- enriched H(2)SO(4) was added into the starting solution and thus equilibrium was approached from above the quilibrium value (see Fig. 4). When isotope exchange occurs between two molecules, X and Y, the reaction rate, r, is related to the extent of exchange, F, at given time, t, by equation (17), where X and Y indicate concentrations of given species, α(e), α(o) and α denote the　fractionation factor at equilibrium, at time　t=0 and at an arbitrary time t, and F = (α - α(o))/(α(e) - α(0)) or the extent of isotope exchange. Assuming the exchange rate is of the first order with respect to both X and Y and to the β'th power of hydrogen ion activity, a(H)(+), eq. (17) reduces to eq. (19), where k(1) denotes the rate constant. If X, Y and pH of solution stayed constant during the run, the half-time, t(1/2), of the exchange reaction can be obtained graphically as shown in Fig. 5. The t(1/2) for runs 1, 2, and 3 are determined to be 5.8, 5.5 and 6.1 hrs, respectively. Introducing F=0.5 and t=t(1/2) into eq. (19), we obtain eq. (20) which is graphically shown in Fig. 6 using the data by the present work and those by Sakai and Dickson(1978). The numerical values of log k(1) + 0.16 may be obtained by extrapolating the lines to pH=0 and, from these values, the rate constant, k(1) , may be calculated for temperatures of 300° and 400℃. From these two values of k(1) and from the Arrhenius plot, the activation energy of the exchange reaction was calculated to be 22 kcal/mole, a much smaller value than 55 kcal/mole obtained by Igumnov (1977). The value of β is found to be 0.29 at 300℃ and 0.075 at 400℃, although the physico-chemical nature of β is not clear to the present authors. Using these values, eq. (24), where C is a constant, is derived which would enable us to calculate the t(1/2) of any system of known ΣS and pH. However, as we do not know yet how β varies with different systems, eq. (24) is applicable only to limited systems in which temperature, total sulfur contents and pH are similar to those of the present study. Fig. 7 illustrates how t(1/2) varies with pH and total sulfur content at 300° and 400℃ and predicts t(1/2) for some solutions obtainable by hydrothermal reactions of seawater with various igneous rocks. The average equilibrium fractionation factor at 400℃ obtained by this study is 1.0153, in good accord with 1.0151 given by Igumnov et al. (1977). Theoretical fractionation factors between SO(4)(2-) and H(2)S have been calculated by Sakai (1968) , who gives too high values compared to the experimental data obtained by this and other researchers (Fig. 9). In the present study, the reduced partition function ratio (R.P.F.R.) of SO(4)(2-) was recalculated using two sets of the vibrational frequencies of SO(4)(2-) (shown in Table 5) and the valence force fields of Heath and Linnett (1947), which reproduces the observed frequencies of SO(4)(2-) better than Urey-Bradley force field used by Sakai (1968). The results of new calculation are shown in Table 6. This table also includes the R.P.F.R. of H(2)S which was calculated by Thode et al. (1971). Using these new R.P.F.R. of SO(4)(2-) and H(2)S, the fractionation factors between SO(4)(2-) and H(2)S were calculated and are listed in the last column of Table 6 and plotted in Fig. 9. Fig. 9 indicates that the new calculation gives values more shifted from the experimental values than before. The major sulfate ions in our solution at 300° and 400℃ exist as NaSO(4)(-) (Sakai and Dickson, 1978; see also Table 4 of this paper) and, therefore, the measured fractionation factors are those between NaSO(4)(-) and H(2)S. The discrepancy between the theory and experiments may, at least, be partially explained by this fact, although other more important reasons, which are not known to us at the moment, may also exist. No potential conflict of interest relevant to this article was reported.

岡山大学温泉研究所 Acta Medica Okayama 0369-7142 54 1984 熱水条件下での諸物質の諸特性 �T 金の膜を通しての水素の透過 55 60 EN Noriaki Kishima 10.18926/21109 Permeation rate of hydrogen through a gold cell made as a reaction vessel for a Dickson-type hydrothermal apparatus was measured at 50°intervals from 300°to 450℃ under a hydrothermal condition. The gold cell chosen for the measurement had a shape and size illustrated in Fig. 1 when it was fully expanded, and was a typical one in the meaning that it had been used several times for hydrothermal experiments (its total history may be equivalent to one month at 490℃) and that it had a body enlarged by about 8% in diameter from the original size as a result of pinhole check made by applying a gas pressure to the inside. The cell was filled with an appropriate amount of pure water, placed in a pressure vessel made of Ni-base alloy, pressurized by injecting water to the outside of the cell and kept under predetermined temperatures and pressure (=1 kbar). Meanwhile, small fractions of the waters inside and outside the cell were sampled at times and analyzed for H(2) gas-chromatographically as described in ref. (5). H(2) concentrations in the samples (CH(2)) were converted to H(2) fugacity values by using the conversion factors (Y) given in ref. (6). At each temperature, the permeation rate (k) of H(2) through the cell is evaluated by correlating the measured fH(2) values with time (t) according to eq. (2), where fo is the fH(2) in the outer water and is a constant, and fi and m are the fH(2) in and the mass of the inner water, respectively. The relevant data and results are shown in Table 1. The present data for the permeation rate φ, expressed in c㎥ H(2) at STP per 1c�u surface area, 1 mm wall thickness, 1 (bar)(1/2) of (fH(2))(1/2) difference and 1 hour, are plotted in Fig. 2 in relation to 1/T (K) and compared with one available data, which is a combination of reported solubility and diffusion coefficient data for hydrogen into gold at higher temperatures. The present data can be fitted into eq. (3). The present result may be of importance for hydrothermal experimental studies of geochemical redox reactions and of hydrogen isotope exchange reactions, and the technique used may also be important as a new, simple method of measuring hydrogen permeability through noble metals. No potential conflict of interest relevant to this article was reported.

岡山大学環境管理センター Acta Medica Okayama 0917-1533 20 1998 過酸化水素のフローインジェクション分析の環境水への応用 22 26 EN Akimasa Iwado Takashi Mukuno Hiromichi Akizawa Masaki Mifune Yutaka Saito 先に開発した過酸化水素のフローインジェクション分析法（FIA）のシステムや触媒カラムに詳細な検討を加え，ppbレベルの過酸化水素の定量法を開発した。また，本研究で得られたFIAを用いて，57〜944ppbになるように過酸化水素を雨水に添加し，回収実験を行った。その結果，回収率と再現性とも良好で，化学発光法より優れていた。なお，FIAでの検出下限は，約10ppbであった。 No potential conflict of interest relevant to this article was reported.

日本分析化学会 Acta Medica Okayama 0525-1931 33 1 1984 イオン会合抽出における陽,陰イオンの相対的抽出性と抽出定数の推定 31 36 EN Shoji Motomizu 水-クロロホルム系でのイオン会合抽出におけるイオンの抽出性の相対的尺度として,陽イオンに対しC値,陰イオンに対しA値を割り当てた.これらの値の算出の際の基準にはアルキル鎖及び水素原子を全く持たない仮想的な陽イオン[-〓N-(+)]をとった.C値,A値と抽出定数(logK(ex))の関係は,logK(ex)=C+Aで表される.陽イオンとして14種の第四級アンモニウムイオン,テトラフェニルホスホニウム(アルソニウム)イオン,5種のアゾ系染料陽イオン,7種のトリフェニルメタン系染料陽イオン及びメチレンブルーのC値を決めた.又π値(置換基の寄与)を用いるC値の計算方法についても考察した.C値を用い,無機,有機陰イオンのA値も決定した.得られたC値及びA値を用いて約150種のイオン会合体の抽出定数を推定し,既報の実測値との比較をしたところ,±0.3log単位程度の誤差であった.又著者以外により報告されている抽出定数との一致も良好であった. No potential conflict of interest relevant to this article was reported.

日本分析化学会 Acta Medica Okayama 0525-1931 34 10 1985 2-ニトロソ-5-ジメチルアミノフェノールとゼフィラミンを用いる銅の溶媒抽出-吸光光度定量 643 645 EN Cheng Rui Shi Shoji Motomizu Kyoji Toei 2-Nitroso-5-dimethylaminophenol (nitroso-DMAP) reacts with copper(II) ion to form a 1:2 complex in an aqueous solution. In the presence of zephiramine (tetradecyldimethylbenzylammonium chloride), a 1:3 complex is formed and can be extracted into chloroform. The excess of nitroso-DMAP co-extracted with complex anion into organic phase can be removed by adding an adequate amount of chloride ion at about pH 12. Maximum absorption wavelength of the copper complex in the organic phase is 468 nm, at which the molar absorptivity was found to be 3.6×10(4) l mol(-1) cm(-1). This method was applied to determine micro amounts of copper in iron and steel samples and aluminium alloys. The procedure is as follows. An adequate amount of the sample was dissolved in aqua regia. The resulting solution was evaporated nearly to dryness. The residue was re-dissolved in distilled water to give an adequate volume. Five milliliters of the sample solution were taken into a stoppered test tube. Ascorbic acid and potassium chloride solutions were then added. Dichlorocopper(I) ion was extracted with chloroform solution of zephiramine. The organic phase was shaken with an aqueous solution containing hydrogen peroxide, nitroso-DMAP, potassium chloride, and potassium hydroxide to form the copper complex of nitroso-DMAP and to remove the excess of reagent in the organic phase. The absorbance at 468 nm was measured against the reagent blank. No potential conflict of interest relevant to this article was reported.

日本分析化学会 Acta Medica Okayama 0525-1931 36 9 1987 ビンドシェドラーズグリーンロイコ塩基を用いるフローインジェクション分析法による過酸化水素の吸光光度定量 561 565 EN Masanori Akiba Shoji Motomizu Kyoji Toei ビンドシェドラーズグリーンロイコ塩基(LBG)を色原体とし,Fe(II)を触媒としたFIA系による過酸化水素の定量法について検討した.弱酸性溶液中,Fe(II)が存在するとLBGは過酸化水素によって725nmに吸収極大を持つ緑色のビンドシェドラーズグリーン(BG(+))に酸化され,この波長での吸光度の増加を利用して過酸化水素を定量した.pH及び共存させる塩酸ヒドロキシルアミンの濃度を調節することにより,過酸化水素が0~1ppmの範囲で検量線は直線性を示す.過酸化水素0.58ppmでの10回繰り返し測定の相対標準偏差は0.4%で,検出限界は5ppb(S/N=2)であった.1時間当たりの分析速度は30検体であった.市販の各種水あめ中のグルコース(3~96%)を,グルコースオキシターゼで反応させた後,FIAで測定した. No potential conflict of interest relevant to this article was reported.

日本分析化学会 Acta Medica Okayama 0525-1931 36 8 1987 吸光光度検出イオンクロマトグラフィーによる河川水中の総炭酸の定量 503 507 EN Takashi Hironaka Mitsuko Oshima Shoji Motomizu 吸光光度検出器を用いたイオンクロマトグラフィーによる,河川水中の総炭酸(炭酸,炭酸水素イオン及び炭酸イオンの合量)の定量法が検討された.吸収を示す溶離イオンとしては,トリメリット酸イオン(1,2,4-ベンゼントリカルボン酸イオン)を用い,陰イオン交換カラム(TSK gel IC-Anion-PW, 4.6mm i.d.×50mm)を用いた.試料中のカルシウム,マグネシウムイオンは,溶離イオンのカルボン酸イオンと反応し,総炭酸の定量に影響を与える.この妨害は,Na型に変えたイオン交換型試料前処理カートリッジカラム(Toyopak IC-SPM)に試料を通すことにより完全に除くことができた.試料中の陰イオンにより,追い出されてきたトリメリテートイオンの吸収は炭酸水素イオンのピークに影響を与え,負の誤差を生じる.この誤差は,試料中に共存する陰イオンのピークの面積の和を用いることにより補正可能であることが分かった.河川水中の総炭酸の定量を行ったところ,FIAにより得られた値と良く一致した. No potential conflict of interest relevant to this article was reported.

岡山医学会 Acta Medica Okayama 0030-1558 68 10 1956 超生体染色所見から見た血球の細胞膜透過性に関する研究 第1編 各種色素の濾紙電気泳動と,それ等色素の正常家兎白血球,網赤血球への超生体染色所見 1705 1719 EN Motomitsu Oguchi Supravital staining of granulocyte, lymphocyte and reticulocyte was carried out with a series of dyes including both acidie and basic ones. On each dye the affinity to cells was observed in those media which pH were changed serially from 1 to 13 using Mcllvaine's or Sorensen’s buffer solution. On the other hand the increasing or decreasing effect of hydrogen ion concentration of media on the charges of dyes was observed electrophoretically. In general, strongly charged dyes, both positive and negative, failed to invade into cells in the whole range of pH, while the Weakly charged dyes showed a positive stain in a certain region of pH, i. e. the acidic dyes in the acidic media and hasic dyes in the basic media, showing the accelerated permeability of dyes to cells in their fairly discharged states. However, some dyes proved to be inpermeable even in their weakly charged states. This inpermeability was attributed to the large molecnlar weight of the dyes or to the sparing solubility to water, alcohol, ether and ether-alcohol. No potential conflict of interest relevant to this article was reported.

Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 33 2 1999 Density Functional Molecular Dynamics of Hydrogen Plasma 51 59 EN Hiroo Totsuji Kenji Tsuruta Chieko Totsuji 10.18926/19671 Density functional molecular dynamics method is applied to hydrogen plasma in the domain of liquid metallic hydrogen. Tentative results for the proton-proton pair distribution function and the electron-proton pair distribution function are obtained. It is shown that with the increase of the parameter γ(s), we have increasingly strong screening of proton charge by electrons and the decrease of electron density in the domain between protons. No potential conflict of interest relevant to this article was reported.

Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 32 1-2 1998 Numerical Analysis of a Model for Isolated Hydrogen Bond 43 54 EN Chieko Totsuji 10.18926/19637 Large isotope effects have been observed in various kinds of hydrogen bonded ferro / antiferroelectrics. In clariflying their origin, themodynamic properties of the hydrogen bond are of essential importance. Two numerical methods are applied to analyze the model for isolated hydrogen bond at finite temperatures and the results of excited energy levels of proton or deuteron are examined. It is found that the second excited state is not far enough from the first excited state to be neglected discussing themodynamic properties of hydrogen especially in their ordered states. No potential conflict of interest relevant to this article was reported.

岡山医学会 Acta Medica Okayama 0030-1558 71 5-2 1959 諸種耳鼻咽喉科領域疾患及び無カタラーゼ血液症におけるHeinz小体の臨床的並びに実験的研究 2755 2768 EN Osamu Kokubu In his clinical and experimental observations on Heinz bodies in various diseases in the field of oto-rhino-laryngology and acatalasemia the author obtained the following results. 1. The mean estimated value of Heinz bodies in normal persons has been 61 ‰ in male and 73 ‰ in female. 2. In chronic sinuitis and chronic otitis media an intermediate acceleration in Heinz body fomation can be seen and only a mild acceleration in chronic tonsillitis. However, no significant fall in the hematocrit value can be recognized in any of these cases. 3. In the patients with cancer in the field of oto-rhino-laryngology the advanced acceleration in the Heinz body formation can be recognized, at the same time the hematocrit value reveals a considerable fall in a reverse proportion to the acceleration. 4. In acatalasemia despite the hematocrit value being within the normal range, the formation of Heinz bodies reveals the highest acceleration. 5. The increment in Heinz bodients in the patients gradually begins to fall after the operative removal of lesions and returns to the normal level, while in the case of malignant tumor it hardly declines even after the removal of tumor. 6. In the estimation of Heinz bodies, the higher acceleration can be recognized in the case where catalase in blood is decreased rather than in the case of anemia. 7. when HCl-hydroxylamine is made to act on pigeons and ducks, having an extremely small amount of catalase in blood, and hens and rabbits supposedly to have normal amount of blood catalase, pigeons show the most marked increment in the Heinz body formation, while on the other hand no significant acceleration can be recognized in hens. 8. When hydrogen peroxide (H(2)O(2)) solution is made to act on the blood of the four animals mentioned above, the acceleration in the Heinz body formation is most striking in pigeons followed by ducks, rabbits, and hens in that order, showing an extremely mild formation of Heinz bodies in hens. 9. In the daily examinations of the blood in the pigeons and hens injected continuously with H(2)O(2), the pigeons reveal a marked increment in Heinz bodins, showing about 87 per cent of the blood, while hens an increase of only about 35 per cent of the blood tested. 10. In the daily examinations of the blood of the pigeons given successive injections of HCl-hydroxylamine the Heinz body formation can be observed far more promptly than in the case of H(2)O(2)-injections in almost 100 per cent of the blood tested. 11. In the daily estimation of Heinz bodies in the blood of the animals receiving successive injections of H(2)O(2)-solutionor HCl-hydroxylamine, the decrease in Heinz bodies contained in erythrocytes commences on the fourth day after the start of injection and returns to the normal level on about the seventh day. 12. Judging from these results, it seems that the presence or the absence of catalase in blood is closely associated with the mechanism of the Heinz body formation. In other words, it is assumed that blood toxin or blood toxin-like substance induces the change in the blood pH, and because of this the catalase activity is either inhibited or inactivated, and it is gradually led from oxidative degeneration of blood components to the formation of Heinz bodies. No potential conflict of interest relevant to this article was reported.

岡山大学医学部附属環境病態研究施設, 岡山大学医学部附属病院三朝分院 Acta Medica Okayama 09133771 57 1986 末梢循環障害への人工炭酸浴の効果 3 8 EN Yoshiaki Komoto Tomoji Kohmoto Mitsuru Sunakawa Hidenori Yorozu Yasuteru Eguchi 10.18926/19630 末梢動脈の慢性閉塞性疾患に対する血行再建術の予後は不良で，虚血肢の治療には一定の見解が乏しく非常に難澁するものである。組織循環の概念にもとづいた評価法によると，医用質量分析装置を用いた虚血肢運動負荷後のPtCO(2)の脱飽和曲線の型により組織循環の良否が定まる。組織循環の良好な型では，自然予後は良好で，いかなる保存的治療にもよく反応する。一方，組織循環の不良な型の自然予後は不良であるので，人工炭酸泉浴によるPtO(2)の増加，および組織循環量の改善により予後は良好となる。人工炭酸泉浴は，組織循環の良好な症例には治癒促進的に作用し，組織循環の不良な症例にも有効に作用する。 No potential conflict of interest relevant to this article was reported.

岡山大学温泉研究所 Acta Medica Okayama 0369-7142 7 1952 三朝温泉の化学的研究(18)-硫黄泉の成因に関する黄鉄鉱多硫化物説- 15 19 EN Takashi Ashizawa 10.18926/19593 In Misasa there occur only few weak sulfur springs, their　maximum hydrogen sulfide content being about 5mg per liter. The ground of Misasa consists of granite and there is no active volcano in the vicinity. So the author tried　to explain the mechanism of the occurrence of sulfur spring in Misasa by a reaction of the primarily alkaline　thermal water upon pyrite. Namely: XFeS(2) + 3Na(2)C(O)3 = 2Na(2)S(1-5) + Na(2)S(2)O(3) + 3CO(2) + XFeS(1-2) Thiosulfate in sulfur spring waters should not be taken for a secondary product from hydrogen sulfide as accepted generally, but is most probably a primary product to the latter. The phenomenon of white turbidity in sulfur spring　is caused mainly by the sulfur liberated from the polysulfide decomposed by the change in pH and temperture of thermal waters and not by the sulfur liberated from the　oxidation of hydrogen sulfide. Some experimental data were　shown to support the theory． No potential conflict of interest relevant to this article was reported.

岡山医学会 Acta Medica Okayama 0030-1558 68 6 1956 インヂカン定量に関する実験的研究 第二編 尿インヂカン定量に関する実験的研究 597 629 EN Tsutomu Shindo 1) Laying emphasis on chemical equation of Jolles's reaction, and systematically examining those causes for mismeasurement happened during urinal determination of indican, I was enabled to find out certain new microestimating method for indican, which would prove somewhat satisfactory. 2) As indicated below, the normal value of urinal indican estimated by new method, have acknowledged certain marvelously high values that have far superseded those theories hitherto known. However, I am to recognize the Principle No. (2) i.e., the quantitative value for indican that was considered to have as its object the colour reaction against the fuming hydrochloric acid, which could purely has enabled to induce it solely into the Thymolindogenide; while, Principle No. (1), i.e., the quantitative value which has for its object the original color of Thymolindogenide, should be recognized as total Indican value, i.e., that was enabled to be induced into every kinds of Indogenide including the very Thymolindogenide: �@ Normal amount (mg) of excretion Within 24 hours. highest 158.0 (Principle No.(1))〜137.0 (Principle No.(2)), lowest 42.5 (〃 〃)〜29.8 (〃 〃), average 98.0 (〃 〃)〜77.0 (〃 〃). �A Normal density mg % highest 22.7 (Principle No.(1))〜19.7 (Prnciple No.(2)), lowest 2.5 (〃 〃)〜1.8 (〃 〃), average 9.3 (〃 〃)〜7.5 (〃 〃). �B Misestimation in quantitative value shown by Principle No.(2) to that of Principle No.(1) is estimated as + 2.2〜 -43.0% ; average, -26.7% . 3) Various stimulants to give rise to mismeasurement on the side of indican at its quantitative determination that have been able to investigate, were as follows. �@ The condensation between the thymol and indoxyl in the urine increasing at a gradual ratio, and the quantitative value shows a proportional increase as time for reaction lengthens; yet, if the reagent due to Takeuchi (Estimating method (1)) should be used, it may come to an end after two hours' reaction. �A The descent in estimation owing to a shortening of reactionary time may roughly be ascribed to the fact that while the condensation between the thymol and indoxyl remains incomplete, the formation of indigo undergoes certain stimulas. �B If one might consider the certain of Jolles's reaction as a principle for indican estimation, it would be told as very unsatisfactory in fact, even after 2 hours of reaction, already it has been seen to have given rise to so marked a difference as -51〜 -71% . Altogether, the chief cause will be pointed out as the incomplete oxidation owing to Obermayer's reagent. �C Order in adding chloroform according to Endo's method, assists to formulate Indigo, but in the same degree affects to decrease to formulate the Thymolindogenide; so that, in 2 hour's reactionary course, it brings about already -20% misestimation. �D Endo's standard solution, though excellent in its tint, its titer value amount even to 3 or 3.6 times larger than its theoretical value, being remarkably dense. This may take place, perhaps, when he decided on titer, Mr. Endo employed for standard the indican value estimated by Takeuchi's method. �E For an urinal oxidizing agent between the thymol and the indoxyl I might mention that of Mr. Takeuchi as best of that kind. The oxidizing agent indicated by 1% potassium chlorate, 3% hydrogen peroside, 1〜5% ammonium persulphate, 4% chlorinated lime, 10% copper sulphate, under the same conditions, only cope with 1/2 power proved by Takeuchi's, at most. Whereas, sodium nitrit cannot stand to be used because apt to produce some nitrosothymol. �F The precipitation rate due to precipitator attributed to urinal indican proves different according to the kinds as well as volume of precipitators. In case 1/10 volume of 20% lead acetate solution or 20% basic lead acetate solution has been added, the precipitation rate proves respectively 26〜36.4% or 15.4〜31.4% ; in case 1/20 volume has been added only the rate 1/3.5 of the former would be seen. The rate of discovery of precipitated indican nearly corresponds to 83〜94% of the entire quantity. �G Extinction curve for the dehydrated chloroform-extract, no matter what kind of test urin, technic, oxydizing agent or precipitator may be emplyed, would come so near the typical curve for Thymolindogenide, yet not so perfectly; the quantitative value due to Principle No.(1) indicating certain indefinite increase, compared to that of Principle No.(2), the cause of which rests with the fact that when the Thymol and Indoxyl in urin condense themselves, though taking care not to formulate the indigo, there will be given birth to certain brown pigment soluble to chloroform, besides the Thymolindogenide. �H When the Thymolindogenide in the urine containing the trichloroacetic acid (urin T.) is estimated, frequent washing of chloroform-extract may be necessary. Or else, the quantitative value indicates an abnormally high value, because of an increase in color tone caused by dehydrated chloroform-extract that has resulted from the increase of urinal trichloroacetic acid; so that one would have a marvelously high value at 80% density. �I The main motive for an increase in estimative value in urine T. is ascribed to those violet or reddish-violet tone that appear within reddishbrown dehydrated chloroform-extract. Its real state might be deemed, not only to depend upon the color reaction effected by Thymolindogenide against hydrochloric acid as well as trichloroacetic acid, but also due to certain color reaction shown by Thymolindo-genide owing to a new appearance of certain ether-like aromatic substance. �J The estimation for urine containing the acetic acid (urine A.) proved that the highest value was reached when urinal acetic acid had indicated about 0.5% density; too much acetic acid found in the urine is apt to make difficult the extraction of the Thymolindogenide due to Chloroform, and leads to lower its value. �K The estimated value for urine T. has proved maximum at about 10% density of urinal trichloroacetic acid; the overmuch amount of urinal trichloroacetic acid, aided by a strengthened color tone maitained by chloroform-extract, rather serves to enhance the estimation. �L The highest value indicated by Thymolindogenide in one and same urine, shows slight difference between urine A and urine T, in the light of principle No.(2); however, as to Principle No.(1); the latter undergoes about 1.5 times increase that of the former. Also, the value for Principle No.(1) against the highest value proved by Prineiple No.(2), amounts to in average 1.3 times in case of the former, but 2.5 times (in average) in the latter. �M The estimation value in urine T. should be corrected owing to a degree of increase. However, that degree tends to become unsteady due to estimating method, principle for the same, density of trichloroacetic acid or washing-method of chloroform extract and so on; so reliability could not be expected. �N The secondary extracted amount of Thymolindogenide for the 1st one which indicated greatest amount has proved, about 20% in case of urine A, 10% in urine T.; the extraction of Thymolindogenide proving better in latter case. �O The estimation mistake shown in Principle No.(1) due to stufenphotometry and colorimetry indicates as about 5% (urine A) and about 10% (urine T) increase in the latter. 4) From the above results as to the causes for misestimation of indican quantity, as well as about normal indican value, it was vindicated that there exists certain strong factors to lower the value in various estimation method for indican where Jolles's reaction deemed as it principle, as well as in such old-fashioned method in which precipitators are used; at the same time, the necessity for re-examination for those various achievement as to clinical significances of urinal indican thus clarified hitherto, by using new method, has become urgent. No potential conflict of interest relevant to this article was reported.

岡山医学会 Acta Medica Okayama 0030-1558 70 12 1958 生体内胆汁色素代謝に関する研究 第3編 嫌気性条件下における肝切片によるbiliverdinよりbilirubinへの還元に就いて 4627 4636 EN Yoshifumi Fujita The prosperity and decay between bilirubin and biliverdin in bile were observed on the action of the liver tissues in guinea pig to the untreated rabbit bile and the treated bile by adding of carbohydrate and or coferment in an anaerobic condition with nitrogen or hydrogen gas. 1. Biliverdin in bile seems to be partly reduced to bilirubin, since the results of the prosperity and decay between bilirubin and diliverdin, on the action of the liver tissue in healthy guinea pig to rabbit bile in an anaerobic condition with nitrogen or hydrogen gas. 2. The reduction of biliverdin to bilirubin is rather stimulated on the action of the liver tissue in healthy guinea pig to the treated rabbit bile by adding carbohydrates of glucose, sodium lactate, aicbol etc. in an anaerobic condition with nitrogen or hydrogen gas than on the use of the untreated rabbit bile, and the reducing process is remarkable on the use of hydrogen gas. 3. The reduction of biliverdin to bilirubin is more markedly stimulated on the action of the liver tissue to the treated rabbit bile by adding of coferment in an anaerobic condition with nitrogen or hydrogen gas than on the use of carbohydrat into rabbit bile, and the reducing process is more remarkable on the use of hydrogen gas. 4. The reduction of biliverdin in bile to bilirubin is most stimulated onthe action of the liver tissue in healthy, guinea pig to the treated rabbit bile by adding both glucose and coferment in an anaerobic condition with hydrogen gas. And these processes seems to be caused by the action of dehydrogenase in the liver tissue. No potential conflict of interest relevant to this article was reported.

岡山医学会 Acta Medica Okayama 0030-1558 71 4-2 1959 血球ミトコンドリアの細胞化学的研究 第2編 血球のチトクローム酸化酵素系に関する細胞化学的研究 1909 1913 EN Akira Sakai It is difficult to make an accurate cytochemical demonstration of the cytochrome oxidase system in the mitochondria of blood cells by the conventional Nadi reaction. By applying the Oda's method for the cytochemical, detection of cytochrome c-cytochrome oxidase system and cytochrome c oxdase the author succeeded in demonstrating cytochemically the cytochrome c oxidase or the cytochrome c-cytochrome oxidase system in the mitochondria of blood cells by using p-phenylenediamine as substrate and neotetrazolium salt as hydrogen acceptor with or without the addition of cytochrome c. This reaction appears in the cytoplasm of all blood cells with an exception of mature erythrocytes in the form of distinct violet-colored round or rod-like granules coinciding with mitochondria. The number, distribution and the grades of the enzyme activity of mitochondria can be seen. whose pictures are specific to each call species. Maturation and differentiation of cells generally proceed with the decrease both in number and enzyme activity. No potential conflict of interest relevant to this article was reported.

岡山医学会 Acta Medica Okayama 0030-1558 70 9 1958 家兎骨髄組織培養に於ける物理化学的要因の偽好酸球運動能に及ぼす影響 第三編 培地水素イオン濃度の影響 附. 全編の総括 3465 3477 EN Saburo Takahashi By addition of hydrochloric acid or causatic soda at various concentrations to bone-marrow tissue culture (cover-slip method) of rabbits, the author studied the influences of medium pH on the motility of pseudoeosinophils and obtained the following results: 1. The limit of pH of the medium which enables such observations of the movement of pseudoeosinophils is pH 7.11-8.05. 2. The more acidic or basic is the medium, the more marked is the decrease in the wandering velocity of pseudoeosinophils. 3. In the medium both acidic and basic, the boundary of the cell is distinct; the shape is irregular with different sizes of granules; pseudopodia are small; and the wandering cycle is indistinct. 4. In the medium which is either highly acidic or basic, the number of cells of Types A and B are less, but those of Types C, E, and I are increased. 5. By changing pH of the medium either higher or lower those with pseudopodia shaped like a tongue are lessened and the cells with saw-like pseudopodia are increased. Moreover, this tendency is stronger as the pH approaches that of the control medium; and what is more it is markedly so in an earlys tage of culture. 6. The tail-shape pattern of Type �T can be found less in the medium of pH 7.36 or pH 7.80, but this type increases in both more acidic and more basic media. Type �U shows a tendency just the reverse of Type �T. Type �V is rare in any medium, but it tends to increase slightly with the lapse of culture time. 7. As for the ratio of the long axis and short axis of a pseudoeosinophils, the smaller ratio increases while the greater ratio decreases, in a more acidic or a more basic medium. No potential conflict of interest relevant to this article was reported.

岡山医学会 Acta Medica Okayama 0030-1558 71 2-1 1959 Urobilinogenに関する研究 第一編 UrobilinogenのFhrlich氏aldehyde反応呈色物質の分光化学的研究 641 650 EN Hiroshi Sakurai The spectrophotometric studies were made on the coloured solutions prepared by the addition of the Ehrlich's aldehyde reagent into the urobilinogen solution (stercobilinogen) prepared from urine and stool, the mesobilirubinogen solution prepared from crystalline bilirubin by a reduction with natrium amalgam, and their salt and mesobilinogen dimethylester etc. And the results are as follows. 1. Both the urobilinogen solution in which stercobilinogen is mainly included and the mesobilinogen solution coloured with the Ehrlich's aldehyde reagent, display the absorption maxima at 560 mμ and 490 mμ at the pH 4.2. 2. When the hydrogen ion density of the above coloured solution becomes below 4.0, the absorption maxima display at 558 mμ and 490 mμ or 492 mμ. Both of these absorption maxima are not moved by the change of pH. 3. In proportion as the pH of the coloured solution becomes high more than 42, the absorption maximum at 560 mμ shifts slightly to the short wave length and displays at 556 mμ or 554 mμ, but the absorption maximum at 490 mμ shifts to the long wave length in a relatively prominent degree and displays at 506 mμ or 510 mμ. As the pH of the coloured solution becomes showing a alkaline reaction, the absorption maximum at 560 mμ disappears and the absorption maximum at 490 mμ shows shifting to the opposite direction, the short wave length. 4. On the use of methanol, as a solvent, instead of water, both of them display the absorption maxima at 550 mμ and 490 mμ at the pH 5.4. And no differences are observed, on the change of the pH, between the coloured substances of stercobilinogen and mesobilinogen with the Ehrlich's aldehyde reagent. 5. As for the absorption maximum of mesobilinogen is observed shifting to the long wave length for 1 or 3 mμ more than that of stercobilinogen under the acid-and weak acid condition of pH. 6. The coloured substances of the sodium-, potassium- and ammonium salts of urobilinogen with the Ehrlich's aldehyde reagent display the same absorption maxima by the change of the pH value, but the absorption maximum shifts to the short wave length for 2 mμ on the occasion of preparing the salts by adding several times of the computation dosis of caustic soda, caustic potash and ammonia more than on the occasion of preparing the salts by adding the computation dosis of them or the absorption maximum of the coloured substance of stercobilinogen itself with the Ehrlich's aldehyde reagent at the pH 1.4-1.0, and it displays at 556 mμ. 7. When the Ehrlich's aldehyde reaction is obtained immediately after the process being moved into caustic soda from the petroleum ether stratum on the preparation of stercobilinogen from stool, the absorption maximum displays only at 556 mμ at the pH 1.6 without showing the absorption maximum around 490 mμ. Therefore, it is thought that the absorption maximum at 420 mμ is not coexisted with the absorption maximum around 560 mμ when the oxidation is prevented on the preparation of urobilinogen or during it's process, and that the absorption maximum of the coloured substance with the Ehrlich's aldehyde reaction displays only one around 560 mμ and the absorption maximum around 490 mμ belongs to that of the urobilin oxygenated from urobilinogen. 8. The coloured substance of mesobilinogen dimethylester with the Ehrlich's aldehyde reagent displays the absorption maxima at 550 mμ and 488 mμ at the pH 3.8. 9. The attitude of mesobilinogen dimethylester to various solvents is markedly different from that of bilirubin dimethylester, and mesobilinogen dimethylester is more unstable to an oxidation than mesobilinogen. No potential conflict of interest relevant to this article was reported.

岡山医学会 Acta Medica Okayama 0030-1558 71 2-1 1959 生体に於けるHem蛋白の分解に関する研究 第1編 肝臓の生理的食塩水抽出液に依るPyridin-verdohaemichromogen並びにGlobin-verdohaemichromogenの生成 343 353 EN Junichiro Mikami The reaction of pyridin-haematin or hemoglobin to the liver extract with physiologic saline solution was observed under various conditions. The results were as follows. 1. The formation of pyridin-verdohaemichromogen from pyridin-haematin was most suitable on the pH 8 of the hydrogen ion density of the reagent on the occasion of installation at 38℃., and the maximum value was observed in the 4th hour. 2. The formation of pyridin-verdohaemichromogen from pysidin-haemin was rather promoted on the pH 8 of the reagent on the occasion of installation at 60℃. than at 38℃., and the maximum value was also accelerated a little. 3. The formation of pyridin-verdohaemichromogen from pyridin-haematin was most powerful on the use of the liver extract of gunea pig among the liver extracts of gunia pig, white rat, rabbit and dog etc. on the occasion of the pH 8 and of installation at 38℃. 4. When pyridin-hematin and the liver extract of gunia pig were installated on the pH 8 at 33℃, the absorption curves of the ether extracts of the hourly reagents by the Engel's method displayed the absorption maximum at 655, 530 and 395 mμ, and the hight of those maximum was 655<530<395 mμ But the absorption maximum at 655 mμ was once elevated with hours until the 4th hour, then declined, and the maximum at 530 mμ was gradually declined without elevation and finally disadpeared, and the maximum at 395 mμ was also declined in some degree. Furthermore, a absorption maximum at 498 mμ was merely observed. 5. The formation of pyridinverdohaemichromogen was suppressed with the elevation of the extract's temperature and obstructed at 100℃. on the reaction between pyridin-haematin and the liver extract of guinea pig. 6. On the formation of globin-verdohaemichromogen on the occasion of installation at 38℃. under the pH 8, the absorption curve of the ether extract of the reagent by the Engel's method displayed the absorption maximum at 630, 540 and 395 mμ at the beginning after washing, and the hight of those maximum was 630<540<395 mμ. The absorption maxiumm at 630 mμ was once elevated with hours until the 16th hour and then declined, and the absorption maximum at 540 mμ was declined in some degree. 7. The absorption curve of the 0.5 % HCl extract after washing with ether and then water according to the Engel's method on the reagent at the 16th hour on the process of globin-verdohaemichromogen formation displayed the absorption maximum at 675 mμ and 366 mμ, and the hight of these absorption maximum was 675<366 mμ. It agreed with the absorption curve of biliverdin in acid solvent. And a light yellowish pigment was obtained from the extraction with chloroform in a weak acid condition after the reduction of the above product with natrium dithionit in weak basic condition, and it showed a positive diazo reaction on the addition of methanol after wahsing. 8. The absorption maximum (at 675 mμ) of the 0.5 % HCl extract solution of the hourly reagents by the Engel's method on the occasion of installation at 38℃. under the pH 8 on the globin-verdohaemichromogen formation by both haemoglobin and guinea pig liver extract were most high at the 16 hour and agreed with the vicissitude of the ether extract's absorption maximum at 630 mμ. 9. The formation of globin-verdohaemichromogen from haemoglobin was more promoted on the occasion of the installation at 60℃. than at 38℃. in the same pH 8. 10. When the guinea pig liver extract was heated on the reaction between haemoglobin and guinea pig liver extract, the formation of globin-verdohaemichromogen was suppressed with the elevation of temperature and obstructed at 100℃. 11. The reaction between haemoglobin and guinea pig liver extract was more promoted by an aeration of molecular oxygen than it was under an installation, but the obtained dosis of globin-verdohaemichromogen was decreased. 12. The katalase activity in the liver extract of guinea pig was rapidly declined with heat, and it was more effective on this occasion than it was effective to suppress on the globin-verdohaemichromogen formation. 13. Since the above results, it is supposed that pyridin-haematin or haemoglobin is analysed to bilirubin by the liver extracts and this process is perticipated by the enzym system. No potential conflict of interest relevant to this article was reported.

岡山医学会 Acta Medica Okayama 0030-1558 70 6 1958 家兎骨髄体外組織培養に於ける含水炭素代謝の研究 第1編 正常家兎骨髄含水炭素代謝並びに健康人血清の該代謝に及ぼす影響に就て 1939 1953 EN Takashi Kimura In observation on the carbohydrate metabolism of bone marrow of normal rabbits by bonemarrow tissue culture (Carrel's flask method) and on the effect of normal human serum on carbohydrate metabolism in the same culture, the following results have been obtained: 1) Sugar consumption increases in proportion to the increase in the rate of tissue frowth in culture. 2) Hydrogen ion concentration in substrate tends to turn acidic along with progress of the tissue growth. 3) With an addition of a small quantity of normal human serum the tissue growth is markedly accelerated, and both sugar consumption and the increase in hydrogen-ion concentration are also promoted. 4) With a large amount of normal human serum added to culture medium, on the other hand, the tissue growth is inhibited and gugar consumption and the increase in the hydrogenion concentration are less. 5) When a proper amount of normal human serum is added, no effect is observable on the tissue growth, sugar consumption and on hydrogen-ion concentration. No potential conflict of interest relevant to this article was reported.

岡山医学会 Acta Medica Okayama 0030-1558 70 3 1958 無カタラーゼ血液症患者血液に対する2, 3細菌の作用について 第2編 菌の呼吸に対する赤血球の影響 913 921 EN Mikitaro Kawata As previously reported in Part �T the author found that hemoglobin had tendency to show the production of MetHb and the decolorization remarkably when Streptococcus hemolyticus, Streptococcus viridans, and Diprococcus pneumoniae �T, �U and �V were cultured in the medium using the blood of acatalasemic patients. These changes clearly have indicated that the blood of these patients lacking in the catalase is unable to dispose of hydrogen peroxide (H(2)O(2)) produced by bacteria and subsequently Hb is oxidized to form MetHb and with progress of oxidation the constituents of the blood seem to turn to decolorization substances such as propentodyopent. This time with a view to clarify this point still further, the author studied action of still bacteria en erythrocytes of the normal and the patients, and from the results of this study arrived at the following conclusion. 1) Diprococcus pneumoniae �U, �V and Streptococcus viridans markedly accumulate H(2)O(2) during oxidation process of glucose. 2) When glucose is used as substrate loaded with acatalasemic erythrocytes and shaken, in the case of Diprococcus pnemoniae �T, �U, or Streptococcus viridans, a marked production of MetHb has bean observed, when normal erythrocytes are loaded, the production of MetHb has been extremely small as compared with each of these bacteria in the case of the acatalasemic erythrocytes. When pyruvate, succinate, or aspartate is used as substrate, the influences of each of these bacteria on erythrocytes are on the whole quite small. 3) Productivity of MetHb and decolorization by bacteria have a parallel relationship with the accumulation of H(2)O(2). 4) Using glucose as substrate, influences of Diprococcus pneumoniae �U on the respiration of erythrocytes are as follows. a. In the case where erythrocytes are not loaded (the control) O(2)-consumption decreases by 60-90 minutes. b. In the case where acatalasemic erythrocytes are loaded, so long as Hb exists, O(2)-consumption continues to rise. c. In the case where normal erythrocytes are loaded, up to 60 minutes O(2)-consumption is comparatively lower than that of the control but it does not fall even 120 minutes later. d. On examining H(2)O(2) in solution after these reactions, an extremely minutes quantity of it has been traced in the case of loading acatalasemic erythrocytes, while none can be traced in the case of loading normal erythrocytes. e. Thiourea and cysteine have been found to completely recompensate whatever influences exerted upon O(2)-comsumption of bacteria by acatalasemic blood. 5) After studying color changes of the erythrocytes to which H(2)O(2) of various concentrations had been adden, the results thus obtained were quite identical with those which erythrocytes had been influenced by respiring bacteria. 6) From these facts as far mentioned it may be assumed that the influences of respiring bacteria upon the acatalasemic erythrocytes are due to the action of H(2)O(2) produced by bacteria. No potential conflict of interest relevant to this article was reported.

岡山医学会 Acta Medica Okayama 0030-1558 70 3 1958 無カタラーゼ血液症患者血液に対する2, 3細菌の作用について 第1編 血液加培地に於ける発育菌の作用 905 912 EN Mikitaro Kawata Ever since Takahara discovered acatasemia in 1946, many studies on the questions concerning causative factors of progressive necrotic ulcers and phsiological significance of catalase have been made public. As there is no report other than that by Miyamoto concerning the relationship between blood of the acatalasemic patient and bacteria and considering this to be an interesting problem, the author conducted a series of experiments with a view to elucidate actions of several bacteria belonging to Streptococcus and Pneumococcus on blood of the acatalasemic patients. Namely, the author carried out aerobic and anaerobic cultures with the medium containing Diprococcus pneumoniae �T, �U, �V, Streptococcus hemolyticus, or Streptococcus viridans, which was loaded with either acatalasemic blood or blood of the normal person, and other series of cultures containing each of the these media loaded still further by inoculation of other medium containing either KCN or hydroxylamine (inhibitory agent of catalase action). By macroscopic and spectroscopic observation on the results of above mentioned expeirments, the following findings were obtained. 1) As regards the rate of bacterial growth under either condition no great difference could be recognized between the medium loaded with normal blood and that with acatalasemic blood. 2) In the cases of aerobic culture, the production of Methb and decolorization in the media containing actalasemic blood tended to be more marked than those in the media with normal blood. 3) In the cases of anaerobic culture, the production of MetHb and decolorization phenomenon decreased in the media containing acatalasemic blood. 4) In the aerobic culture with the medium loaded with inhibitory agent of catalase action, the rate of MetHb production and decolorization phenomenon were about the same in both the medium with normal blood and the medium with patient's blood. While, in anaerobic cultures influences of addition of these agents could hardly be discerned. 5) Since the blood of patient doss not contain catalase, the production of MetHb and decolorization phenomenon in the medium containing acatalasemic blood seem to have occured due to influences of hydrogen peroxide (H(2)O(2)) produced by bacteria. No potential conflict of interest relevant to this article was reported.

岡山医学会 Acta Medica Okayama 0030-1558 73 4-6 1961 骨髄体外組織培養に於ける人白血球の退行性変化に関する研究 第2編 各種培養条件の好中球退行性変化に及ぼす影響について 285 305 EN Koji Shinagawa The normal human bone marrow was cultured in vitro by the clinical tissue culture method devised in our Department in order to see the influences of such factors as the medium temperature, the hydrogen ion concentration, the osmotic pressure in the media, and some single media, on the degenerative changes of neutrophils appearing in the growth area. These results were compared with those in the case of neutrophils cultured in the normal medium. The following are the conclusions. 1. In general the degenerative changes of neutrophils proceed slowly under low temperature but more rapidly at higher temperature. At 15℃ the progress is most slow while on the contrary, at the temperature below 10℃ it is rapid, The number of degeneration granules, vacuoles, and abnormal processes decreases as the bone marrow is cultured at a lower or at a higher temperature centering around 37℃-39℃. More condensed nuclei can be observed at a high temperature, and also at a low temperature. The eruption of the nucleus appears more frequently at low temperature, however, there is almost no nuclear eruption at high temperature. 2. As for the influence of the hydrogen ion concentration, the further away is the pH from that of the normal medium the more rapid is the degenerative changes. In the acid medium the appearance of small degeneration granules is more rapid but the number of vacuoles and sbnormal processes is less, showing no tendency of fusion of nuclear lobes but a strong tendency of non-homogeneous pyknosis. In alkaline medium degeneration granules are less but vacuoles and blisters are numerous, and cytoplasm is swollen, and nucleus tends to swell up or to erupt. 3. As for the influence of the osmotic pressure, in the isotonic solution the degenerative changes appear most slowly, and in the hypotonic solution the swelling of specific granules is marked and degeneration granules are numerous and large with many vacuoles. Cytoplasm and nulcleus are swollen, especially the eruption of the nucleus is striking. In the hypertonic solution the swelling of specific granules is observed, but the number and the size of degeneration granules are small. Vacuoles and abnormal processes are less, while myelin forms can be recognized relatively many. The nucleus and cytoplasm are condensed at the initial stage of the culture but later both of them are swollen. 4. In the single medium such as physiological saline solution, Ringer's solution, serum, or in the isotonic glucose solution, the degenerative changes proceed radidly at an early stage in any of these media, and the changes progress most rapidly in the glucose solution followed by physiological saline solution and Ringer's solution. The progress is slowest in the serum medium but it is more rapid than in the normal medium. No potential conflict of interest relevant to this article was reported.

岡山医学会 Acta Medica Okayama 0030-1558 75 11-12 1963 肝臓組織培養に関する研究 第1編 廻転培養法による家兎肝臓の至適培養液の組成に就いて 981 989 EN Kenwo Asano The author has conducted tissue culture of rabbit liver by roller tube method. The pH changes in culture media were estimated. The rise of hydrogen ion concentration in the course of culture was parallel to the rate of cell increase. The most appropriate medium has been a fluid medium consisting of 70% Hank's solution, 20% rabbit serum and 10% chick embryo extract. Without chick embryo extract the cells found to grow do not easily grow out, but in its high concentration fibroblasts grow very well. Amoung the various sera rabbit serum is the most accelarative to the growth of liver cells. Human serum is second and horse serum worse in promoting activity. The ascites with stomach cancer almost dose not show promoting activity to liver cells. In addition of small amount of rabbit serum to the medium liver cells exhibit an excellent growth, but the more the serum becomes concentrated, the more fibroblasts grow. No potential conflict of interest relevant to this article was reported.

岡山医学会 Acta Medica Okayama 0030-1558 72 8-10 1960 人癌及びマウス癌組織の組織培養に関する研究 第2編 人子宮頸癌及びBashford氏マウス癌並びに正常マウス肝組織の組織培養に於ける糖代謝に就いて 1581 1593 EN Akinori Shiraishi The roller-tubo tissue cultures of human cervical carcinoma, Bashford's mouse carcinoma, and normal mouse liver tissue were performed in order to inquire into carbohydrate metabolism in the culture media. Glucose consumption, lactic acid, pyruvic acid, and α-ketoglutaric acid productions in cutlure media by human and animal tumors and by normal mouse liver tissue were estimated, and the following results have been obtained. 1. Glucose consumption and lactic acid production by human cervical carcinoma and Bashford's mouse carcinoma were in higher level than by normal mouse liver tissue. This was considered as the fact showing the high glycolysis of tumor tissues in vitro. 2. The ratios of lactic acid production/glcose consumption, pyruvic acid production/glucose consumption, α-ketoglutaric acid production/glueose consumption, in each tissue, were compared with each other. The ratio of lactic acid production/glucose consumption in every tissue turned out to be quite similar in values. But the ratios of pyruvic acid production/glucose consumption and α-ketoglutaric acid production/glucose consumption in Bashford's mouse carcinoma, were very low, about one third and one tenth of normal mouse liver tissue, respectively. In human cervical carcinoma, the ratio of pyruvic acid production/glucose consumption showed almost the same value as normal mouse liver tissue, but the ratio of α-ketoglutaric acid production/glucose consumption in human cervical carcinoma was half the value of normal mouse liver tissue. Thus pyruvic acid and α-ketoglutaric acid production, the components of tricarboyylic acid cycle, were reduced in tumor tissuen in vitro inspite of the same glucose consumption and lactic acid production as in normal mouse liver tissue in vitro. Therefore, the carbohydrate metabolism, as for the tricaroxylic acid cycle in tumor tissues, turned out to be different from normal mouse liver tissue. 3. The changes of hydrogen ion concentration in the culture media were in step with the course of tissue cultures. And the pH in tissue culture media had a correlation with the lactic acid production by tissues in vitro. But the increase in the pH was closely correlated with the lactic acid, pyruvic acid, and α-ketoglutaric acid productions by human cervical carcinoma, Bashford's mouse carcinoma, and normal mouse liver tissue in culture media. No potential conflict of interest relevant to this article was reported.

岡山医学会 Acta Medica Okayama 0030-1558 72 1 1959 Biliverdinの赤外部分光化学的研究 第2編 Bilirubinを酸化して得たBiliverdin赤外部吸收像に就いて 113 117 EN Takashi Nakahaara Biliverdin was obtained from cystallized bilirubin by adding hydrogen peroxide in hydrochloric acid alcohol. The biliverdin, separated in the column chromatography with an absorbent of silica gel and a developer of glacial acid, was confired by physicochemical features, absorption spectra in the ultraviolet and visible ranges. In its infrared absorption spectra, a broad absorption band ranging over 6.06 μ to 6.40 μ, other than the absorption band of carbonyl group at 5.91 μ (the C=O streching vibration of the carbonyl group (C=O)), was detected, and it was deemed probably responsible for mixture of the ionized carboxyl group instead of water of crystallization. Also the absorption band ranging over 3.80 μ to 5.00 μ. of hydrochloric acid was observed. Consequently, it was presumed that the separated, by our method, contained not only biliverdin but also hydrochloric double salt and probably mixture of acetic acid double salt. When hydrochloric acid was neutralized with caustic soda before the column chromatography, in its infrared absorption spectra, the absorption band of hydrochloric acid have disappeared, but the one of the ionized carboxyl group was still noted, presumably due to mixture of acetic double salt of biliverdin stemmed from glacial acetic acid using as a developer. No potential conflict of interest relevant to this article was reported.

岡山医学会 Acta Medica Okayama 0030-1558 80 5-6 1968 分光光度法による入血液カタラーゼ活性の定量および低カタラーゼ血液症のスクリーニング法について 第3編 本法の検討と活性測定に関する基礎的実験 625 630 EN Yoshito Nakagawa The present communication deals with the principle of measuring and calculating the catalase activity of human blood by UV method. Under the conditions previously described, it has been clarified that the reaction of catalase-hydrogen peroxide practically follows the first order kinetics within 30-120 seconds. The velocity constant, k, seems to have no concern with the substrate concentration within the range of 0.005-0.025 mole. Catalase values, Kcat, measured under room temperature, are about 10% lower than those taken at 37℃. It has been found that measurements of the catalase activity have to be taken within 5 minutes after hemolysis No potential conflict of interest relevant to this article was reported.

岡山医学会 Acta Medica Okayama 0030-1558 80 1-2 1968 無カタラーゼ血液症に出現する高原氏病の成因についての実験的研究 第�U編 酸化酵素に対する過酸化水素の影響についての生化学的研究 189 196 EN Tooru Takehisa With the purpose to know how is the effect of hydrogen peroxide on the succinic dehydrogenase system, experimental studies were conducted using duck, rabbit and mouse. The results obtained were as follows. I. In vivo study After injection of hydrogen peroxide in isotonic saline into the palate of ducks, having only a trace amount of catalase in their blood, inhibition of the activity of succinic dehydrogenase system was observed in the homogenate of their palate. Activity of succinic dehydrogenase system in the homogenate of palate of ducks, injected four times, decreased more markedly than that of duck injected ones. �U. In vitro Study 1) Activity of succinic dehydrogenase system in the homogenate of duck palate or mouse muscle, containing less amount of catalase, or in the mouse liver homogenate with addition of NaN(3), decreased more markedly than that of rabbit palate or mouse liver containing more amount of catalase. 2) Activity of succinic dehydrogenase system in the homogenate of the various tissues was decreased by addition of hydrogen peroxide. On the other hand, inhibited activity of succinic dehydrogenase system by hydrogen peroxide recovered as time lapses. From the above findings it is considered that the activity of succinic dehydrogenase system inhibited by hydrogen peroxide is reversible. Therefore, it seems that the causative factor of the gangrene in acatalasemia cases lies in the fact that so called respiratory enzyme group such as succinic dehydrogenase system in tissue cells, are disturbed by the accumulation of hydrogen peroxide produced from hydrogen peroxide generating micro organisms (hemolytic streptococcus, pneumococcus etc.) No potential conflict of interest relevant to this article was reported.

岡山医学会 Acta Medica Okayama 0030-1558 82 7-8 1970 急性頭蓋内圧亢進時の髄液酸塩基平衡に関する研究 361 372 EN Akihiro Doi The author devised on pparatus for continuous monitoring of acid base balance of CSF without any CSF exposure to the atomosphere. The apparatus is an extracorporeal "ventriculo-cisternal circulation system" which is consisted of pressure pump, glass capillary electrode, Clark PO(2) eleotrode and Severinghaus Pco(2) electrode, all-lined up on a stainless steal conduit betweeen　lateral ventricle and cisterna magna. In the experimental cases of 5 dogs, the ventriculo-cisternal circulation system was used for monitoring acid base balanec of the CSF under acute intracranial hypertension produced by extradural balloon inflation. The blood Pco(2) was constantly watched during experiment to be kept in the normal range by means of a respirator. Pco(2) in the CSF began to increase in early stage above the pressure of CSF of 300 mmH(2)O and incseased more and more in parallel with raised pressure. HCO(3)- in the CSF was decreased when acute and more severe intracranial hypertension was maintained for hours. Hypercapnic acidosis and　metabolic acidosis occured in the CSF specifically when the intracranial pressure was raised acutely. Clinically, acid base balance of the CSF was studied on acute intracranial hypertension of three patients who suffered from brain tumor. Intracranial pressure was monitored continuously by pressure gauge transducer connected to the ventricular drainage. In this clinical research, CSF, arterial blood and jugular blood were sampled for measurement. Pco(2) in the CSF was increased　when the intracranial pressure was elevated above 500mmH(2)O and metabolic　acidosis was added when the pressure was more elevated continued. That is to say, CSF　became acidosis as same as experimental results. On the contrary, arterial　blood became respiratory alkalosis when the intracranial pressure was elevated　to 500-1000mmH(2)O. This phenomenon suggest that increse of hydrogenic ions induced by intracranial hypertension stimulates respiratory center. Hypercapnic acidosis and metabolic acidosis occur specifically in　the CSF independently from the change in the blood when the intracranial　pressure rises. Namely, the acid base balance of the CSF can not evaluated　from that of the blood. The author adovocates this state is hidden acidosis. No potential conflict of interest relevant to this article was reported.

岡山医学会 Acta Medica Okayama 0030-1558 79 3-4 1967 脾臓組織培養に関する研究 第2編 培地の物理化学的条件の影響について 139 152 EN Koichi Shimazaki 1) The author observed the influences of osmotic tension upon the clinical tissue culture of mouce's spleen. In the hypotonic medium, although the rate of relative growth was higher than in the isotonic medium, the cell density was lower and in the wandering velocity of lymphocytes no significant difference was shown. In the hypertonic medium the rate of relative gromth, the index of cell density and the wandering velocity of lymphocytes were lower than in the normal medium. 2) The author observed the influences of temperature upon the clinical tissue culture of mouce's spleen. The most suitable temperature to culture was from 35℃ to 37℃, and the range of temperature in which culture was possible was from 25℃ to 39℃. At 33℃ and 35℃ the progress of degenerative process was delayed. 3) In order to observe the influences of hydrogen ion concentration of media upon the clinical tissue culture of mouce's spleen, the author cultured by adding the various concentration of hydrochloric acid or sodium hydroxide in the medium. In acid medium the growth was possible even by adding 1/100 N hydrochloric acid, and in alkaline medium the culture was possible even by adding less than 1/500 N sodium hydroxide. All the rate of relative growth, the index of cell density and the wandering velocity of lymphocytes, except the rate of relative growth in the medium adding 1/1000 N hydrochloric acid, were lower especially in high concentration of acid or alkali than in the control medium adding physiological salt solution. 4) According to these results in the clinical tissue culture of spleen, except relatively lower temperature, it was shown that unphysiological physicochemical conditions suppressed or stimulated the growth of tissue culture and were harmful to culture. No potential conflict of interest relevant to this article was reported.

岡山医学会 Acta Medica Okayama 0030-1558 81 9-10 1970 高原氏病に出現する口腔壊疽についての実験的研究 第2編 無カタラース血液症血液および正常人血液に対する過酸化水素産生菌の作用 609 622 EN Yasuo Mitani As described in Part 1, by injecting Diplococcus pneumoniae which generates hydrogen peroxide under the mucous membrane of the palate of duck, there appeared pathological changes in duck palate resembling macroscopically and microscopically the findings observed in acatalasemia cases. Being without definite conclusion on the point of action mechanism of hydrogen peroxide, it was assumed that the changes in duck palate were caused by hydrogen peroxide generated by the cocci. To illustrate the point of action mechanism of hydrogen peroxide and the etiology of Takahara's disease the degradation of oxyhemoglobin and the methemoglobin-formation in culture of these cocci supplemented with duck blood, rabbit blood, acatalasemic blood or normal human blood were investigated by the following methods in each chapter. No potential conflict of interest relevant to this article was reported.

岡山医学会 Acta Medica Okayama 0030-1558 81 9-10 1970 高原氏病に出現する口腔壊疽についての実験的研究 第1編 肺炎双球菌により惹起された家鴨口蓋粘膜病変の組織学的研究 601 608 EN Yasuo Mitani In acatalasemia we often encounter specific oral gangrene called Takahara's disease. With the purpose to elucidate the causative factor of this gangrene, ducks having only a trace amount of catalase in their blood or plalate tissue were used as experimental animals. Diplococcus pneumoniae (Type �U) is known to generate hydrogen peroxide and contains little or no catalatic substance in itself. By suspending this Diplococcus pneumoniae in isotonic saline solution of 0.75% glucose, this suspension was injected under the mucous membrane of the duck palate. Then histopathological investigations and macroscopical observations were carried out at certain intervals after the injection. The results obtained were as follows. 1) Macroscopically, 24 hours after injection there appeared whitish coat and slight reddening and swelling surrounding the coat, and 72 hours after injection gangrene resembling the one observable in acatalasemia cases appeared. 2) Experimental histopathological study showed marked changes in blood vessel wall, In contrast, pathological changes of muscles and glands were hardly observed. Now we hold such hypotheses proposed by Kaziro or Takahara that dysfunction of the so-called respiratory enzyme group or oxygen deficiency due to methemoglobin-formation are the causative factors of this disease. From these results, it is assumed that the macroscopical and histopathological changes in duck palate resembling the findings observed in acatalasemia cases were caused by the oxidative action of deposit of hydrogen peroxide generated by Diplococcus pneumoniae (Type �U). The action mechanism of hydrogen peroxide is not definitively clarified from these results. But it is certain that the circulatory disturbances brought about by the marked changes in blood vessel wall, especially the wall of arteries, seem to evoke definitively oral gangrene. No potential conflict of interest relevant to this article was reported.

岡山医学会 Acta Medica Okayama 0030-1558 84 11-12 1972 低カタラーゼ血液症の簡易検出法に関する研究 第3編 低カタラーゼ血液症の新簡易検出法:Floating Disk Method 397 404 EN Yoshiaki Takagoshi The way of preserving blood specimens is an important factor on the screening tests for acatalasemic gene carrier. Because, the decay time of catalase activity in blood depends on the physical conditions, largely on temperature, where the blood specimens are kept. The author investigated the decay rate of catalase activity under following conditions. 1. Preservation of human blood in a vacuum flask at the temperature of 0〜10℃. 2. Preservation in a deep-freezer at -20℃. In the former condition the blood specimen did not lose catalase activity at least seven days, and afterwards decay went on gradually. On the contrary, in the latter frozen specimens some degree of decay occurred soon. Afterwards, however, they kept constant catalase activity, 84% of the initial value, for months. So, it is concluded that for the practice of screening tests preservation in a vacuum flask at the temperature of 0〜10℃ is preferable. Next, the author devised a handy, feasible way of screening tests named the !! floating disk method. !! It is a modification from M. Gagnon's estimation of catalase activity by measuring floating time of a piece of paper disk dipped with enzymatic specimen in hydrogen per-oxide solution. The screening level set up by this method is 12.5cm for the depth and 13.5 sec for the floating time. No potential conflict of interest relevant to this article was reported.

岡山医学会 Acta Medica Okayama 0030-1558 84 5-6 1972 固型試料投入法を用いたガスクロマトグラフイーによる尿中17-KS分画の測定に関する研究 95 108 EN Shigeru Sato Since the introduction of gas-liquid chromatography by Janes and Martin for the qualitaive assays of various chemical substances, this method proved to be an excellent one for isolation and identification of a variety of oily liquids as well as many other substances. The gas-liquid chromatography has been used also in the analysis of steroids affording many satisfactory results. However, this method has one great disadvantage in the when a minute quantity of urinary 17-KS (ketosteroids) is placed in liquid form it is not possible to avoid the loss of test material other than in the first trial, and also the peak of the solvent often interferes with the peak of the steroid making it difficult to make an accurate chart of the mixture of steroids of varying concentrations. Therefore, the authors devised a new gas-liquid chromatography in which the steroids are first adsorbed into a stainless steel gauze and then inserted into the specimen chamber, and we find that this eliminates the appearance of solvent peaks, as observable in the routine gas-liquid chromatography. By this method we separated and analyzed seven fractions of urinary 17-KS; namely, androsterone, etiocholanolone, DHA, 11-OH-adrosterone, 11-OH-etiocholanolone, 11-oxo-androsterone and 11-oxo-etiocholanolone. The apparatus used was the super-sensitive gas chromatograph with GC-1B solid insertion attachment and hydrogen flame ionization detector of Shimazu Mfg. Co. For the column we used 2% NGS (Shimazu product). The test material was a part of the 24-hour pooled urines. The urine was hydrolyzed by solvolysis and β-glucuronidase (the twostep hydrolysis), and the residue (neutral steroids) was sebarated into 17-KS and corticosteroids by Florisil column chromatography. Further, the 17-Ketosteroid fraction was separated into 11-deoxy-17-KS, 11-oxy-17-KS and Pd fraction by the alumina column chromatography. This chromatography serves as the prechromatography of the 2% NGS' gas-lipuid chromatography by which we can isolate DHA from 11-OH-androsterone as well as androsterone from Pd. With the fractions isolated in this manner we esperified them in the presence of trimethylsilyl ester, and we studied the ratios of anderosterone, etiocholanolone, DHA, as well as the ratio of 11-deoxy-17-KS to 11-oxy-17-KS in the 7 fractions isolated from the urines of female with normal menstrual cycle, normal adult males, and females with endocrine disorders. The results of our study may briefly be summarized as follows. In the urine of females of normal menstrual cycle adrosterone, etiochlanolone and DHA of 17-Ketosteroids tend to be higher before the ovulation and during the corpus luteum period. In the urine of normal adult male the pattern of 17-KS tended to show a high androsterone level and high androsterone ratio. In the case of Hirstism a marked increase of 11-deoxy-17-KS was observed, and the aderosterone ratio tended to show a similar value as in the male. In the cases of testicular feminization syndrome the characteristic feature was the fall in the aderosterone ratio. In the ACTH loading test. 11-deoxy-17-KS responded in the order of DHA>etiocholanolone>androsterone. Also 11-oxy-17-KS responded well. In the dexamethasone inhibition test of 11-deoxy-17-KS; DHA was inhibited most markedly, while 11-deoxy-17-KS were all inhibited uniformly. No potential conflict of interest relevant to this article was reported.

岡山医学会 Acta Medica Okayama 0030-1558 92 9-10 1980 金属水銀酸化における鉄化合物と過酸化水素の役割について 1061 1064 EN Hiromi Aikoh The uptake of metallic mercury with ferric and ferrous ions was studied. The results were; (1) Mercury uptake of free ferric ion increased with hydrogen peroxide, the maximum uptake was 1.0 mM. However, ferric ion was not taken up without hydrogen peroxide. (2) In the presence of ferric and ferrous ions with hydrogen peroxide, mercury uptake was maximum when the mole ratio (Fe(3+)/Fe(2+)) was 0.1. No potential conflict of interest relevant to this article was reported.

岡山医学会 Acta Medica Okayama 0030-1558 92 9-10 1980 金属水銀のカタラーゼによる取り込みに関する研究 第1報 金属水銀の枯草菌カタラーゼによる酸化 1055 1059 EN Noboru Hirota Crude Natto Hay Bacillus extract of catalase without hydrogen peroxide showed a 22% decrease with hydrogen peroxide. With hydrogen peroxide plus potassium cyanide, a 48% decrease occurred with hydrogen peroxide, in regard to the ability to take up mercury from air saturated with mercury vapour. Purified extract without hydrogen peroxide showed a 63% decrease with hydrogen peroxide compared to hydrogen peroxide plus potassium cyanide which showed a 76% decrease with hydrogen peroxide alone. Hydrogen peroxide plus sodium azide showed a 97% decrease with hydrogen peroxide alone. The results were similar to human and mouse normal and acatalasemic erythrocytes or mouse lung and liver homogenates. Natto Hay Bacillus extract of catalase took up mercury from air saturated with mercury vapour. This indicates that the catalase-hydrogen peroxide system plays a role in mercury uptake presumably by oxidation. No potential conflict of interest relevant to this article was reported.

岡山医学会 Acta Medica Okayama 0030-1558 92 9-10 1980 金属水銀のカタラーゼによる取り込みに関する研究 第1報 カタラーゼ活性の異なる動物赤血球の金属水銀の取り込みの差異と粗赤血球カタラーゼ液による取り込み 999 1005 EN Katashi Kenmotsu The uptake of metallic mercury was studied using erythrocytes with different catalase activities taken from various kind of animals. The results were: 1) The uptake of metallic mercury by erythrocytes paralleled the activity of catalase in the erythrocytes with and without hydrogen peroxide, suggesting that the erythrocyte catalase activity is related to the uptake of metallic mercury. 2) The uptake of metallic mercury occurred not only with purified human erythrocyte catalase but also with hemolysate. 3) The uptake of metallic mercury by purified human erythrocyte catalase was inhibited by inhibitors of catalase, namely 3-amino-1,2,4-triazole, potassium cyanide and azide. It was concluded that erythrocyte catalase activity has an important role in the uptake of metallic mercury. No potential conflict of interest relevant to this article was reported.

岡山医学会 Acta Medica Okayama 0030-1558 91 7-8 1979 局所脳圧迫による神経機能障害に関する基礎的研究 第2編 術後に神経機能障害を残さないための術中の指標について 961 976 EN Syunichiro Fujimoto To evaluate the effect of brain retraction during neurosurgical procedures, changes of N(1) components of somatosensory evoked potential (SEP), cortical blood flow (CoBF) by a hydrogen clearance method and histology were studied following local brain compression with a brain spatula in 25 mongrel dogs. Local compression pressure (LCP) at 20 mmHg for 30 minutes was applied four times with five minute intermissions during which time the pressure was completely released. In the same way, the procedures were done at varying levels of LCP, namely 40, 60 and 80 mmHg respectively. Results were as follows: 1) The more the numbers of repetitive compression increased at each pressure level or the more LCP was raised, the more both N(1) amplitude and CoBF decreased. 2) When LCP was more than 40 mmHg and/or N(1) amplitude decreased by more than 50 % during brain compression, SEP did not recover for two hours after compression was ceased. In addition, histological study demonstrated cortical microhemorrhage and edema. It is likely that LCP over 40 mmHg and reduction of N(1) amplitude by more than 50 % during brain retraction produces postoperative neuronal dysfunction. 3) In the noncompressed hemisphere, N(1) amplitude, CoBF and histology were not changed to any significant degree. No potential conflict of interest relevant to this article was reported.

岡山医学会 Acta Medica Okayama 0030-1558 91 7-8 1979 局所脳圧迫による神経機能障害に関する基礎的研究 第1編 水素クリアランス法の基礎実験および脳灌流圧低下の神経機能に及ぼす影響 937 960 EN Syunichiro Fujimoto Following brain retraction with graded local compression pressure (LCP), somatosensory evoked potential (SEP) to median nerve stimulation and cortical blood flow (CoBF) by a hydrogen clearance method were studied at the primary somatosensory area in mongrel dogs. LCP was raised by 10 mmHg every 30 minutes. As the first step, a basic experiment of the hydrogen clearance method was performed, and its reliability and usefulness were confirmed. Studies included changes of SEP, CoBF and histological examination following reduction of cerebral perfusion pressure (CPP). According to the different methods of producing reduction of CPP, dogs could be grouped into three. Group 1 consisted of 9 dogs in which CPP was reduced by exsanguination. Group 2 included 11 dogs which had normal saline infused into the cisterns magna. Group 3 was composed of 11 dogs which had local brain compression. In the exsanguination group, there was a threshold type relationship between N(1) amplitude of SEP and CoBF. N(1) amplitude started to be suppressed when CPP decreased to 40-50 mmHg (CoBF decreased by 35 % ), and was suppressed by 50 % when CPP became 30-40 mmHg, and it was finally abolished when CPP became 20-30 mmHg (CoBF decreased by 55 % ). There were no abnormal histological findings. This suggests that neuronal dysfunction is dependent only on reduction of cerebral blood flow. In the cisterns magna infusion group, changes of N(1) amplitude were quite different from those of the exsanguination group. N(1) amplitude started to decrease as cisterna magna pressure (CMP) increased despite CoBF remaining unchanged. N(1) amplitude had decreased by 50 % when CMP arose to 70 mmHg (CPP, 70-80 mmHg), and flattened when CMP was raised to over 110 mmHg (CCP, below 30 mmHg). It is assumed that neuronal dysfunction relied on not only CoBF reduction but also compression of nerve fibers secondary to dilation of ventricles and subarachnoid space. Local compression decreased both N(1) amplitude and CoBF more markedly than the other two groups. N(1) amplitude decreased as soon as local compression was added, was suppressed by 50 % at 50 mmHg of LCP (CPP, 90-100 mmHg), and flattened when LCP was elevated over 90 mmHg (CPP, below 60 mmHg). This suggests that the immediate, severe occurrence of neuronal dysfunction was due to both disturbance of cerebral circulation and destruction of neuronal architectures by brain distortion following mechanical injury. This study supports the concept that brain spatulae should be applied with caution during brain retraction in neurosurgical procedures because both cerebral circulation and neuronal function are easily disturbed. No potential conflict of interest relevant to this article was reported.

岡山医学会 Acta Medica Okayama 0030-1558 94 7-8 1982 動物性ペルオキシダーゼによる金属水銀取り込みとL-dopaによるその抑制作用について 629 632 EN Hiromi Aikoh The uptake of metallic mercury by lactoperoxidase was measured. The results are described as follows: (1) The uptake of metallic mercury by lactoperoxidase in the presence of hydrogen peroxide was 10 times higher than that in the absence of hydrogen peroxide. (2) The uptake of metallic mercury by lactoperoxidase in the presence of L-dopa in the Lact. -H(2)O(2) system decreased, and decreased further as the concentration of L-dopa increased. (3) The uptake of metallic mercury by lactoperoxidase in the Lact. -H(2)O(2) system showed a tendency to increase, when the concentration of hydrogen peroxide increased. (4) The uptake of metallic mercury by lactoperoxidase increased with an increase in the lactoperoxidase concentration when the concentration of L-dopa and H(2)O(2) in the Lact. -L-dopa-H(2)O(2) system was constant. This uptake was similar in value to the increase changed by increase in the concentration of hydrogen peroxide. No potential conflict of interest relevant to this article was reported.

岡山医学会 Acta Medica Okayama 0030-1558 94 5-6 1982 無カタラーゼ血症に関する研究 第二編 正常および無カタラーゼ血症マウスの赤血球からのカリウムイオン遊出について 447 452 EN Seiichi Matsuda A study of erythrocyte fragility caused by hydrogen peroxide (H(2)O(2)) of relatively high concentration was conducted by means of measuring potassium ion (K(+)) release from erythrocytes by potassium ion electrode. Erythrocytes used in this experiment were of normal and acatalasemic mice. The following results were obtained; 1. K(+) release from red blood cells of normal mice was more than that from red blood cells of acatalasemic mice. 2. In the presence of ethylalcohol (EtOH), K(+) release from red blood cells of normal mice was suppressed, while that from red blood cells of acatalasemic mice was scarcely influenced by the existence of EtOH. It is suggested that this phenomenon is due to the fact that catalase shows peroxidatic activity and decreased oxygen generation from H(2)O(2) in the presence of EtOH. 3. Discussion was made between hemolysis caused by hydrogen peroxide on one hand and fragility of red blood cell membrane and catalase activity on the other. No potential conflict of interest relevant to this article was reported.