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In the course of studies on the cleavage reaction of S-(isopropylcarboxymethyl) glutathione (GSIV) into isovalthine in kidney homogenate or glutathionase preparation, it has sometimes been observed that the amount of isovalthine formed is far less than that of GSIV decomposed¹. Furthermore, when such reaction mixture is analyzed on an automatic amino acid analyzer, prominent peak corresponding to the reasonable amount of S-(isopropy1carboxymethyl)cysteinylglycine which is an expected intermediate of the GSIV cleavage reaction cannot be found up to 400 effluent ml. Though several reasons may be considered for the explanation of the above curious phenomenon, the effect of cystathionase on isovalthine is at first examined here. But the result was negative. L- and L-Alloisovalthineused as substrate were prepared by the method of OHMORI². Homoserine and purified cystathionase in ammonium sulfate solution prepared according to the method of GREENBERGB³ were kindly furnished by Prof. M. Suda of Osaka University. Incubation mixture contains 0.1 ml of enzyme solution, 1.0 ml of 0.2 M borate buffer (pH 8.0) containing 2×10-³M cysteine, 0.lml of 0.1 M substrate, and 0.8ml of deionized water containing 5×10-4M EDTA. The mixture was shaken at 37°C for 30 minutes in the air. The reaction was terminated by adding 2ml of 10% trichloroacetic acid and the α-keto acids formed were determined by the method of FRIEDEMANN and HAUGEN4 with a following modification: toluene extract was washed once with 8 ml of 10% sodium sulfate. The results obtained are summarized in Table l. When the reaction mixtures are analyzed before or after incubation on an automatic amino acid analyzer, the amount of L- or L-Alloisovalthine is found to be unchanged. Furthermore, as indicated in Table 1, L-isovalthine showed no inhibitory effect on the homoserine cleavage by cystathionase. Since amino acid oxidases have already been reported to have no effect on isovalthine³, the curious phenomenon above cited may have to be explained by other reaction mechanism such as transpeptipation reaction.

Effects of antioxidants, such as superoxide dismutase, vitamin C, vitamin E, 4-(0-benzylphenoxy)-N-methylbutylamine hydrochloride (bifemelane), and selenite on survival of adult rat hepatocytes were examined under normoxic and hyperoxic conditions in serum-free primary culture. The tested antioxidants, except for vitamin C, significantly increased the survival rate of hepatocytes under the normoxic condition (under air). Thus, even the normoxic culture condition is hyperoxic for hepatocytes. Elevation of oxygen tension (40% O2) caused severe morphologic degeneration of hepatocytes and remarkable decrease in the survival rate of the cells. Addition of the antioxidants effectively protected hepatocytes from the morphologic degeneration, and significantly improved the survival of the cells under the hyperoxic condition. These findings indicate that the antioxidants can maintain the long-term survival of hepatocytes in serum-free primary culture.

We performed a long-term follow-up of 4 patients with penile cancer who underwent hyperthermotherapy from August 1985 until August 1992. Hyperthermia was applied using a frequency of 350 MHz with a waveguide applicator twice a week for 60 min each for an average of 9.5 times (varying from 6 to 13 times). The total heating time that the temperature of urethra could be kept above 42 degrees C, was 166 min on the average (ranging from 0 to 463 min). Two patients classified as stage I according to the Jackson classification and 1 patient classified as stage IV underwent combined radiotherapy and received an average radiation dose of 53 Gy (range, 40-70 Gy). Among these patients 2 underwent combined chemotherapy with bleomycin or peplomycin. Malignant cells disappeared posttherapeutically and in August 1992, after an average of 5 years and 9 months (varying from 4 years 6 months to 6 years 10 months), the patients were free of recurrences. The one patient on stage IV had extensive invasion of the abdominal wall, but still recovered completely. One patient on stage III underwent combined chemotherapy and hyperthermotherapy, but heating had obviously been insufficient. There was a residue of malignant cells after the treatment and we performed a penectomy. Regarding functional preservation of the penis a multidisciplinary therapy incorporating hyperthermotherapy can be expected to increase the curativity. This indicates that it could induce in an advanced case, where an operation would be difficult, complete remission.

Levels of plasma cyclic AMP, serum immunoreactive insulin (IRI), serum c-peptide immunoreactivity (CPR) and blood sugar (BS) were determined 0, 15, 30, 45 and 60 min after a glucagon injection (0.01 mg per kg body weight) in normal controls, patients with acute hepatitis and liver cirrhosis. Plasma cyclic AMP responses to glucagon in liver disease patients varied widely in peak value, and only in patients with fulminant hepatitis and decompensated liver cirrhosis with poor prognosis was the response suppressed. The peak response of BS was found significantly later in liver cirrhosis patients than in normal controls. IRI and CPR responses to glucagon were lower in acute hepatitis patients than in normal controls and liver cirrhosis patients. IRI levels and their sum were also lower in acute hepatitis patients, although CPR levels were not significantly different. Thus, the ratio of the sum of CPR from 0 to 60 min to that of IRI was significantly higher in acute hepatitis, indicating impaired pancreatic secretion of insulin to glucagon stimulation as well as increased uptake of insulin by the liver in acute hepatitis.

An exposure to GB virus C/hepatitis G virus (GBV-C/HGV) was studied among populations at risk for blood and sexual exposure to analyze risk factor of the transmission of the virus. Blood samples were drawn from 98 intravenous drug users (IVDU), 100 female high-class commercial sex workers (CSW) and 50 male outpatients (MOP) at a sexually transmitted diseases (STD) clinic in Chiang Mai, Thailand. These blood samples were analyzed for GBV-C/HGV RNA; antibodies against second envelope protein of GBV-C/HGV (anti-E2); anti-hepatitis C virus antibody (HCV-Ab); hepatitis B core antibody (HBcAb); and antibodies against human immunodeficiency virus (HIV-Ab). Prevalences of GBV-C/HGV RNA, anti-E2, HCV-Ab, HBcAb and HIV-Ab were 27.6%, 16.3%, 84.7%, 76.5% and 45.0% in IVDU; 0%, 21.5%, 2.0%, 72.0% and 11.0% in CSW; 6.0%, 13.6%, 0%, 64.0% and 14.0% in MOP. While the prevalence of GBV-C/HGV RNA was higher in IVDU than in CSW and MOP, comparable prevalences of anti-E2 among the three populations were found. Intravenous drug injection showed association with GBV-C/HGV RNA, while history of STD associated with anti-E2. In conclusion, intravenous drug injection and STD were found to be risk factors for the previous exposure to GBV-C/HGV, but STD did not increase the risk of the GBV-C/HGV viraemia.

Ki-67 is a commercially available mouse monoclonal antibody (MoAb), which reacts with a nucleolar antigen (the Ki-67 antigen) expressed in proliferating eukaryotic cells. The author examined the precise localization of the Ki-67 antigen in C-6 cells using immunohistochemical and immunoelectron microscopic methods and estimated the proliferative activity of human brain tumors in situ. Positive nucleoplasmic reactions (early G1 phase) and nucleolar staining (late G1 phase) were observed. The cells showed very weak positive reactions in only one or two nucleoli (S phase) and multiple spicule reactions in the nucleoplasm (G2 phase). During the mitotic phase, the Ki-67 antigen was stained on the surfaces of all chromosomes and finely dispersed in the cytoplasm. By immunoelectron microscopic study, positive reactions were observed on the granular and dense fibrillar components. Therefore, the Ki-67 antigen seems to participate in the processing and assembly of preribosomal particles. In human brain tumors, the Ki-67 score (positive cells/total neoplastic cells), ranging 0 to 36.7%, correlated well with the histopathological grade of malignancy of the tumor. These findings suggest that immunohistochemical staining with the MoAb Ki-67 can be used as a convenient procedure for the simple evaluation of the proliferative activity of brain tumors.

A progesterone receptor (PR) in human uterine cervical nuclei was demonstrated by a nuclear exchange assay using a synthetic progestin, promegestone (R5020) as a radio-labeled ligand. Total exchange of previously bound progesterone with R5020 was achieved by incubation at 0 degree C for 3 h. A 0.6 M KCl solution was used to extract the nuclear PR in uterine cervical tissue, and the dextran coated charcoal (DCC) method was used to separate the free [3H] R5020 from the bound form. Scatchard plots of nuclear PR binding showed two components with dissociation constants of Kd = 2.3 X 10(-10) and 4.6 X 10(-9) M. Three histological regions of the uterine cervix was studied as to their nuclear PR contents throughout the menstrual cycle. In the follicular phase, the connective tissue (CT) had the highest PR concentration (658.9 fmole/mg DNA), followed by the columnar epithelium (CE) (253.6 fmole/mg DNA), and the squamous epithelium (SE) (184.7 fmole/mg DNA). In the luteal phase, there was no significant difference among the three regions. Comparing these phases of cycle revealed that the CT had higher PR contents in the follicular phase than in the luteal phase, but no such difference was found in the CE or SE. These three regions had the same Kd value in both phases.