Search

To establish the most proper method of in situ hybridization in detection of HCV-RNA in the liver, various detailed procedures were examined using frozen as well as paraffin-embedded sections of tissue derived from patients. In frozen sections of the liver from hepatitis C patients obtained at autopsy or surgery, HCV-RNA was detectable by in situ hybridization using thymine-thymine dimerized oligonucleotide DNA probes when the sections were treated with ethanol-acetic acid at first, then 0.2 N hydrochloric acid, proteinase K (0.02 u/ml) and DNase. When the paraffin-embedded liver sections were used, more intense proteinase K treatment (0.2-2 u/ml) was required to expose viral RNA and even after that, the positive HCV-RNA signals were less than those in frozen sections, because the cytoplasmic RNA in the routine paraffin-embedded sections was preserved unevenly and less than in frozen sections. These findings indicate that in situ hybridization of HCV-RNA is useful for diagnosing HCV infection and should be a potent tool for monitoring the state of virus activities during therapy. However, the liver biopsy method should be modified so that RNA is retained properly to utilize biopsies more effectively for the routine diagnosis of HCV infection.

Since detection of hepatitis C virus RNA by the polymerase chain reaction (PCR) showed that there existed anti-C100-3 (anti-HCV) antibody negative patients infected with HCV, we attempted to find out whether there were any clinical or viral genomic differences between the anti-HCV antibody positive and negative groups. One hundred and fifty-nine patients with chronic liver diseases with hepatitis C virus RNA in their sera were selected. Anti-HCV antibody was tested for anti-C100-3 antibody by an enzyme linked immunosorbent assay. The incidence of anti-HCV antibody was 129/159. The concentration of serum gamma-globulin, the titier of ZTT, and the positive rate of the PCR with the primers of the NS3/4 region (NS3/4PCR) were significantly higher in the anti-HCV antibody positive group than in the negative group. However, the other data such as alanine aminotransferase activity or past history were not significantly different. Nucleotide sequence of the cDNA fragments of NS3/4 region amplified by the PCR did not differ significantly between isolates from anti-HCV antibody positive and negative sera. The sequences observed in the present study did not differ significantly from those reported previously. Although there remains the possibility that the variation of viral genomic sequences may cause the absence of anti-HCV antibody, these results suggested that the individual clinical backgrounds or immunoreactivity of the patients might influence the antibody development.

As has been well established, reticulocytes (RC) synthesize the species specific protein, globin, actively for about 24 hours or more till the time of their complete maturation1,2,3. This will be possible only in the presence of messenger RNA (m-RNA)4,5. Since the splendid hypothesis of m-RNA proposed by JACOB and MONOD6 for explaining the mechanism of the transfer of genetic information from nucleus to cytoplasm, it has largely been accepted through the numerous observations that followed7,8,9,10. However, the m-RNA hypothesis, which has been deduced by observing the protein synthesis in E. Coli, includes the meaning of labile RNA which is incessantly decomposed and newly synthesized to compensate the rapid degradation. As m-RNA cannot be synthesized in RC which have no detectable DNA, it has been supposed that the m-RNA of RC should be considerably stablell,12,13. Even in the denucleated cells, however, the RNA synthesis might be possible because Borsook reported the positive RNA synthesis of RC14, and this result has recently been reconfirmed by BURNY15.

The synthesis of nuclieic acids in the liver and the lymphoid tissues of adult mice was studied during the restitution period after the 6-day starvation. The results obtained indicate that there occurs an unexpected rapid synthesis of DNA in the hepatic parenchymal cells during the restitution period without significant increase in the total amount of DNA in the liver. Most rapid DNA-synthesis in the liver appears to occur one day after refeeding. With respect to RNA in the liver as well as to both RNA and DNA in the lymphoid tissnes, on the other hand, there is a good parallelism between the rate of their synthesis and that of increase in their amounts, without apparent dissociation between both rates as seen in the liver DNA.

1. For the purpose to clarify the mechanism of the revolutional changes in energy metabolism during the reticulocyte maturation the metabolisms of glucose and of the pentose moieties of acid soluble nucleotides have been observed on rabbit reticulocytes incubated in vitro under various conditions. 2. The maturation of reticulocyte proceeds by using the energy produced by aerobic glycolysis and is arrested in the glucose deficient medium, but the pentose moieties of purine nucleotide and nucleoside added exogenously serve as the energy source for reticulocyte maturation even in the absence of glucose. 3. The test on the utility efficiency of glucose and inosine as the energy source for reticulocyte maturation revealed that glucose is used more effectively than the pentose moiety of inosine under aerobic condition, which is advantageous for reticulocyte maturation, and vice versa under anaerobic condition, which is comparable to the metabolism of mature red cell. 4. From these results it has been suggested that the maturation of reticulocyte is the process of degradation of RNA and acid soluble nucleotides supported by the aerobic glycolysis, where the degradation products of RNA and acid soluble purine nucleotides provide the purine derivatives as the material for ATP synthesis (36) and the pentose moieties as energy source. 5. A possible mechanism for the superior utility of glucose to nucleoside pentose during reticulocyte maturation and vice versa in mature red cell has been discussed.

With the bone marrow of anemic rats, which had received the repeated injections of phenylhydrazine once a day for three to four days, the effects of aminopterin and bromouracil on the nucleic acid metabolism of erythroblasts were observed in vivo experiment. The injection of aminopterin suppressed DNA synthesis with the lowered labeling index as observed by the incorporation of ³H-thymidine into DNA in vitro. But the grain count per cell showed the level similar to that of anemic control. RNA synthesis was not interfered by AP injections. These results indicate that AP mainly suppresses the thymidilate kinase. Bromouracil showed no such effect even on the administration of a large dose. On the basis of the data obtained from the experiment by using AP, a discussion was made on the correlation between DNA synthesis, nuclear function and the cell specialization.

The disappearance of nucleolus has been traced in the rat erythroid cells in relation with the cell specialization under varying conditions, i. e. in anemia with or without treatment by bromouracil and aminopterin. To make the findings more reliable the observations have been made on tissue section as well as on the smeared samples as the nucleolus becomes often indistinct in smeared cell. The results indicate that under anemic condition nucleolus is lost by the late basoplilic stage. Treatment with bromouracil retained the nucleoli and cytoplasmic basophilicity till later stage of cell specialization suggesting some similar mechanism of RNA disintegration both in nucleolus and cytoplasm.

The present investigation was carried out to see effects of muscle cornin, an alcoholic fiaction of boiling-water extract from rabbit skeletal muscle, on the nucleic acid synthesis in the early development of Pseudocentrotus depressus. In this study, the author used the assay method of our own device by which we can estimate the incorporation into whole cell simultaneously that into nucleic acid fraction, with one and the same specimen. The results of the observations are briefly summarized as follows. 1) Cornin accelerated the incorporation of 3H-uridine into whole cell by 10-20 %. 3H-thymine, 3H-thymidine and 3H-uracil all inhibited such incorporation. 2) As to the incorporation into the RNA, it was retarded in the course of phosphorylation at the synthetic stage. 3) In the incorporation into DNA, since the incorporation is inhibited by about 2/3 at the synthetic stage, it seems that the polymerization is inhibited. 4) This inhibition of the DNA synthesis was also substantiated by the autoradiography with tritiated thymidine. Some coments were made on the operation of the nucleic acid synthesis, the specific protein structure during the early development of sea urchin egg, and effects of cornin on these as well as on the other intrinsic substances.

In vitro and in vivo experiments were conducted for the purpose to determine whether or not the antitumor factor found in the regional lymph node cells of the mouse sensitized with Ehrlich tumor cells would transfer its antitumor activity to normal lymph node cells. In in vivo experiments normal lymph node cells incubated at 5°C for 60 minutes in the supernatant containing the antitumor activity have shown the antitumor activity against JTC-11 cells in mixed culture. Namely, it hs been demonstrated that the antitumor activity in the supernatant can be transferred directly to normal lymph node cells in vitro. In the in vitro experiments, the same results as in in vivo experiments were obtained. The antitumor activity against JTC-11 cells has been detected in the lymph node cells obtained on 4, 7 and 9 days after subcutaneous and intraperitoneal injections of the supernatant having antitumor activity. Next, we tried DNase and RNase treatments of the sensitized supernant to observe the transfer factor-like snbstance. The results indicate that, while the passive transfer is possible with the supernatant treated with DNase, it is not with the RNase-treated supernatant. From these findings it is assumed that the factor (in the sensitized supernatant) capable of conferring the antitumor activity is an RNA-dependent substance (or a substance closely associated with RNA) and is probably different from the antitumor factor reported in Parts 1 and 2.

For the purpose of revealing whether AMD inhibits the RNA synthesis of erythroblasts in an effective dose in vivo to eradicate erythroid cells in rabbit bone marrow, the author observed the RNA synthesis by H3-uridine incorporation in vitro and RNA level on the cells from the anemic animals taken at a certain period after a single injection of AMD in a small dose of 50 and 100μg/kg body weight. The data revealed that by such a small dose of injection of AMD the RNA synthesis of erythroid precursors, early basophilic and proerythroblast stages, was successfully suppressed without any suppressing effect on the RNA synthesis of erythroblasts in the later stages of specialization, indicating that there are at least two kinds of RNA synthesis: one seen mainly in the earlier stages of specialization and the other one seen mainly in the later stages, and they can be distinguished from each other by the AMD sensitivity.

For the purpose to get the information about the control mechanism of erythropoiesis in bone marrow the author introduced a mass of homologous red cells into anemic animal and observed how the bone marrow cells and circulating blood react against the prompt normalization of the anemic condition. After the red cell transfusion which was enough to restore the anemia promptly the red cell number in the circulating blood continued to increase until 72 hours after the transfusion, reaching an extremely high level in both red cell number and hemoglobin contents. Mitotic index and the DNA synthesis as observed by tritiated thymidine incorporation into DNA proved no actual change even 24 hours after the red cell transfusion, though a marked decrease in labeling index was found in large size precursors. Histologic picture revealed the proliferation of reticulum cells. 48 to 72 hours after the red cell transfusion both mitotic index and DNA synthesis of erythroblasts have largely retarded in all series of specialization with the decreased appearance of the erythroblasts in bone marrow sections. The measurements of red cell size and the RNA contents of erythroblasts and reticulocytes proved the accelerated denucleation at the early stage of erythroid cell specialization, as early as basophilic stage resulting in a marked macrocytosis.

For the purpose of settling the specialization stage of erythroblast where the transcription for hemoglobin is initiated, the absorption of heme and the incorporation of tritiated uridine into RNA have been observed on the cells from the anemic rabbit after a mass red cell transfusion by which the DNA synthesis of large size precursors is suppressed and the early denucleation of erythroblasts is stimulated. In the erythroblasts obtained 24 to 72 hours after red cell transfusion a distinct absorption of heme appears first in the proerythroblast, followed by a progressive increase with the advance of the specialization. Hemoglobin synthesis is markedly stimulated after the denucleation. The incorporation of tritiated uridine into RNA is most marked in the proerythroblast and decreases with the advance of specialization stage suggesting that the mRNA synthesis for hemoglobin is initiated at the proerythroblast, continuing to the polychromatic erythroblast where. the synthesis is minimized. The volumetric observations indicate a possible denucleation at proerythroblast, but it has been revealed that the maximum RNA level of macrocytes is comparable to that of early basophilic erythroblast and its highest hemoglobin level is only that expected in the cells denucleated at late basophilic stage. From these observations it has been concluded that the transcription for hemoglobin is triggered at the initial step of erythroid cell specialization, proerythroblast, but it is insufficient for the synthesis of the expected amount of hemoglobin and is compensated or completed by the mRNA synthesis in more advanced stage of specialization.

The contents of nucleic acids in rat liver and hepatoma mitochondria and the physico-chemical properties on DNA's isolated from these mitochondria were comparatively investigated. The results are briefly summarized as follows. 1. The contents of DNA and RNA per mg protein of the hepatoma cell mitochondria were about 10 and 2 to 4 times higher than those of rat liver mitochondria, respectively. 2. The λ max. and λmin. values of DNA isolated from the hepatoma mitochondria were 257 mμ and 231 mμ, respectively and those of DNA isolated from the nuclei were 259 mμ and 233 mμ, respectively, in saline-citrate, pH 7.0. 3. Three fractions of mitochondrial DNA were obtained by the sucrose density gradient and these DNA fractions corresponded, probably, to about 30 S, and 20 S and 14 S DNA's. 4. There was little difference in base compositions between nuclear and mitochondrial DNA's of the hepatoma cells. 5. The degree of hybridization between the nuclear and mitochondrial DNA's of the hepatoma cells was almost the same as that between the nuclear and nuclear DNA's of the hepatoma cells, and somewhat higher than that between the nuclear DNA of rat liver and the nuclear DNA of hepatoma cells. 6. "Highly twisted" circular, "open" circular and linear forms were observed in the DNA preparations of the hepatoma mitochondria. The average values of contour lengths of rat liver and the hepatoma DNA's observed at high frequency were 5.3 μ and 4.5 μ. 7. A discussion was made on the relation between the genetic informations of mitochondrial DNA and the formation of a mitochondrion in rat liver and the hepatoma cells.

Activities of intracellular RNase of the liver cytoplasm, normal liver cells exposed to 3'-Me-DAB and heaptoma cells, have been studied in correlation with the contents of RNA and DNA and morphologic changes of the cells with or without treating RNase. The data showed that in hepatoma cells the intracellular acid RNase activity decreases with the decrease of RNA and unchanged DNA contents and alkaline RNase activity. Morphologic observation proved that hepatoma cells show a small low massed vesicular or vacuolar endoplasmic reticulum having ribosomes. For the exposure to RNase the hepatoma cells proved to be much less resistant comparing to normal liver cells. The former lost the granules and was destroyed in its endoplasmic reticulum, whereas the latter retained ribosomes and ER. From these experiments it has been speculated that acid RNase in the cell may be involved in RNA synthesis and alkaline RNase in RNA decompostition, though the effect of the difference in concentration in the case given RNase experimentally can not be neglected.

The authors have succeeded in isolating a biologically-active leukemia virus from leukemic tissues of AKR mice with a fluorocarbon. From the chemical analysis of the biologically-active virus fraction it has been clarified that the AKR leukemia virus is of the RNA type.

Conventional therapy for colorectal carcinoma using 5-fluorouracil (5-FU) has shown limited antitumor action. The purpose of our study was to investigate synergistic antitumor effects of the streptococcal preparation of OK-432 and 5-FU, and to elucidate the mechanisms of interaction between the 2 agents in mice. Biochemical modulation of OK-432 and 5-FU were determined in vivo against colon-26 carcinoma. The concentration of 5-FU and its metabolites, and the activity of thymidylate synthase and thymidine kinase, respectively, were measured using cytosolic extracts of the tumors. Combination treatment with OK-432 produced a significant increase in intratumor 5-FU and 5-FU in RNA (F-RNA) concentrations, increased the thymidylate synthetase inhibition rate, and decreased thymidine kinase activity, as compared with the results observed in the control mice. These additive antitumor effects are obtained by use of the 2 agents; the mechanism of action is considered to be the suppression of both the de novo and the salvage pathway for DNA synthesis, along with the suppression of RNA synthesis.

We have developed a reliable internally controlled RT-nested PCR method for the detection of hepatitis C virus (HCV) RNA using in vitro synthesized Renilla luciferase (Rluc) RNA as an internal control. Using this method, the 5'-noncoding region of HCV RNA (144 nucleotides) and Rluc RNA (276 nucleotides) were efficiently amplified in a single tube, and the sensitivity and specificity of this method were comparable to standard RT-nested PCR. This method was successfully performed on RNA specimens obtained from in vitro HCV-infected human hepatocyte PH5CH8 cells, which support HCV replication. In addition, we demonstrated that this method was useful for the evaluation of antiviral reagents by confirming the anti-HCV activity of bovine lactoferrin, which we previously found to be a new inhibitor of HCV infection. Therefore, this method may be useful for the studies of not only HCV but also of other viruses.

Trial of Rous sarcoma virus (RSV) induction by cell fusion with chick embryo cells (CEC) and wing web test from so-called RSV-transformed human cells, KC and RSb cells, was unsuccessful. The loss of RSV inducibility was also confirmed by DNA transfection method. Southern blot and northern blot hybridization of DNA and RNA from those cells with the v-src probe revealed that the v-src genes in those cells were defective and not expressed. On the other hand, the v-src gene in RSV-transformed mouse and rat cells was complete and transforming virus was inducible from them.</P>

Genetic variation of hepatitis C virus was assessed. We prepared RNA fractions from 21 patients' sera which were positive for hepatitis C virus RNA, synthesized their cDNAs, and amplified fragments, 406 base pairs, encoding a putative core protein, by polymerase chain reaction. One of them, N 15, was cloned and sequenced. N 15 showed 92.4% homology at the nucleotide level and 97.0% homology at the amino acid level compared with HC-J 1 which is the first isolated clone in Japan and similar to that isolated in USA. By restriction fragment length polymorphisms analysis, 14 out of 21 patients (66.7%) showed the same pattern as N 15. No patients showed the pattern of HC-J 1. We could not find a correlation between the genetic variation and clinical features of hepatitis C virus infection. These results indicate that the region, which encodes the core protein and is believed to be relatively conserved in hepatitis C virus genome, has several variations at the nucleotide level, and the major part of hepatitis C virus in Okayama district is different from HC-J 1 and the USA clone.