Biomedical subjects
Publications and source records attributed to C Sato.
A rare case of choledochal cyst complicated by papillary adenocarcinoma in the cystically dilated intrahepatic bile duct is reported. The tumor was located in the neck of the cystic lesion, and imaging modalities failed to show communication between the cystic lesion and the bile ducts.
A 35-year-old woman with clinical features of Budd-Chiari syndrome is presented. Abdominal ultrasonography, computed tomography, and venography disclosed that the venous congestion in this patient resulted from complex venous anomalies including azygos-hemiazygos continuation, absent superior hepatic veins, and retroaortic transposition of the left renal vein.
A rapid screening test was developed to detect CGG repeat expansion of the FMR-1 gene causing the fragile X syndrome by a non-radioisotope PCR technique. A biotin-labeled primer was initially used and the biotin-labeled PCR product was detected by means of chemiluminescence. The normal PCR product of around 300 bp was not created in the abnormal FMR-1 gene sample with this method. Four positive samples were found among those from 226 mentally retarded males, but the CGG repeat expansion was shown on Southern blot analysis in only one sample. To eliminate false-positive samples, a hybridization method involving a biotin-labeled (CGG)s oligonucleotide was developed for the PCR product and the CGG repeat expansion could be detected. Finally, 256 mentally retarded males in Japan were examined and only 2 abnormal samples were detected. The prevalence of this abnormality was less than 1%, which is relatively lower than those reported previously.
The low density, detergent-insoluble membrane fraction (LD-DIM), where gangliosides are likely to be highly enriched, was prepared from sperm of two sea urchin species, Hemicentrotus pulcherrimus and Strongylocentrotus purpuratus. Immunoblotting showed the presence in the LD-DIM of two receptors for egg ligands, a glycosylphosphatidylinositol (GPI)-anchored protein, and four proteins which may be involved in signal transduction. Co-immunoprecipitation revealed that at least three proteins, the speract receptor, the 63kDa GPI-anchored protein and the alpha subunit of a heterotrimeric Gs protein, are localized in the LD-DIM. This suggests that the LD-DIM fraction may be a membrane microdomain for speract-speract receptor interaction, as well as the subsequent signal transduction pathway involved in induction of sperm respiration, motility and possibly the acrosome reaction.
Intermediate filaments are a major component of the cytoskeleton of eukaryotic cells. Although there appear to be at least five distinct classes of these filaments, cells of mesenchymal origin and most cells in culture contain the intermediate filament composed of the subunit protein vimentin. Vimentin exists in a nonphosphorylated as well as in a phosphorylated form, and there is increased phosphorylation of this protein when the filament undergoes marked redistribution in various cells. The role of phosphorylation on assembly-disassembly and organization of the vimentin filament has remained obscure. We report here a stable and purified system allowing biochemical examination of vimentin filament assembly and disassembly. Using this in vitro system, we carried out stoichiometrical phosphorylations, using purified protein kinases. We obtained evidence for site-specific, phosphorylation-dependent disassembly of the vimentin filament.
In order to characterize the expression of adrenomedullin during pregnancy, we measured the mature and total concentrations in maternal plasma and amniotic fluid, and examined its expression in fetoplacental tissues. Plasma samples were obtained from 13 normal normotensive non-pregnant women and 14 normal normotensive post partum women. Maternal plasma and amniotic fluid samples were obtained from 37 normal pregnant women (10 in the first trimester, 13 in the second trimester and 14 in the third trimester). Fetoplacental tissues were obtained from first and third-trimester pregnancies. Mature and total adrenomedullin concentrations in plasma and amniotic fluid were determined by using specific radioimmunoassay. The distribution and expression of adrenomedullin were determined using immunohistochemistry, reverse-transcriptase polymerase chain reaction, and in situ hybridization. Plasma total adrenomedullin concentrations were increasing with advancing gestation. The mature/total adrenomedullin ratio in the second trimester was the highest during pregnancy. Mature and total adrenomedullin concentrations in the amniotic fluid were significantly higher than those in the maternal plasma throughout gestation (P< 0.05). Mature adrenomedullin concentrations and the mature/total adrenomedullin ratio in the amniotic fluid increased with advancing gestation. There was a significant linear correlation between amniotic fluid and maternal plasma mature/total adrenomedullin ratio in the first or second trimester of pregnancy. Adrenomedullin mRNA was identified in the amniotic membrane and chorionic villi, and within the endothelial layers of villous blood vessels. These results suggest that the mature/total adrenomedullin ratio is modified in maternal plasma and amniotic fluid with advancing gestation.
Plasma glutathione levels were determined in 79 patients with various types of liver disease and 18 healthy controls in order to study their significance in the course of liver disease. Plasma was taken at the time of needle liver biopsy. A positive linear correlation was found between plasma and hepatic glutathione concentrations, as has been suggested in experimental animals. In patients with acute viral hepatitis, chronic hepatitis, non-alcoholic liver cirrhosis and alcoholic liver disease, plasma glutathione levels were significantly decreased compared with those in controls. Of importance is the fact that the plasma levels increased after recovery in patients with acute viral hepatitis and after abstinence from alcohol intake in patients with alcoholic liver disease. Determination of plasma glutathione may be valuable in the evaluation of liver disease, particularly in acute viral hepatitis and alcoholic liver disease in which the hepatic content of glutathione is suggested to be decreased. Such patients may be susceptible to oxidative stress and radical-related hepatic injury.
To investigate the role of lymphocytes frequently observed in the parenchyma of alcoholic liver disease (ALD), lymphocytes infiltrating into the liver were stained immunohistochemically with monoclonal antibodies (MoAb) and were quantitatively assessed by a morphometric analysis in 17 patients with ALD and, for comparison in five patients with chronic active hepatitis B (B-CAH). In patients with alcoholic hepatitis, the number of CD8+ lymphocytes in the hepatic lobule was similar to that in patients with B-CAH but was significantly greater than that in alcoholics with hepatic fibrosis (HF). The CD4/CD8 ratio in the hepatic lobule was low in both alcoholic hepatitis and B-CAH compared with that of alcoholic patients with HF. When Mallory bodies (MB) and lymphocytes were simultaneously stained with a specific antibody against MB and MoAb, respectively, only CD3+ and CD8+ lymphocytes were found to have a close contact with MB. These results suggest that in alcoholic hepatitis, hepatocyte necrosis may be partly mediated by immunological mechanisms involving cytotoxic T cells infiltrating into the hepatic lobule.
We found Encephalitozoon-like organisms in an in vitro culture of a human liver lesion which was due to larval Echinococcus multilocularis. The organisms developed in the same fashion as an Encephalitozoon cuniculi. The spores that developed in parasitophorous vacuoles were 2.0-2.6 x 1.1-1.5 microns; each contained a single nucleus and 4-5 polar tubule coils, closely resembling E. cuniculi in its ultrastructure. Mature spores were collected from the supernatants by the use of Percoll centrifugation resulting in the banding of the spores on continuous gradients. We prepared three sorts of spores which were different in buoyant density in 0.15 M NaCl: 1.05-1.07 g/ml spores, 1.12 g/ml spores, and spores of over 1.14 g/ml. Polyclonal antibodies to a pool of each spore preparation were produced in a rabbit and applied to the detection of microsporidian antigen in situ. The histoimmunoperoxidase (HIP) procedure was used to detect the microsporidian antigen in echinococcal liver lesions from patients with alveolar hydatid disease (AHD). Ten echinococcal liver lesions from different AHD patients were examined and four were found to be positive in the HIP test. The Percoll-separated spores were also used as an antigen to detect for antibodies in the sera from the patients with AHD by Western blotting. Antibodies were detected in 62 (52%) of the 119 AHD patients and in only 8 (5%) of the 159 normal healthy individuals.
Microsporidian spores were developed from cells which were grown in vitro from a human liver lesion which was due to larval Echinococcus multilocularis. The microsporidian spores developed in the same fashion as an Encephalitozoon cuniculi. The Encephalitozoon-like spores were completely separated on Percoll gradients. The separated spores contained DNA capable of amplification by two different primer sets designed for the polymerase chain reaction (PCR) of E. multilocularis DNA. However, the cell DNA from which microsporidium developed was thoroughly insensitive to the PCR using the E. multilocularis primer sets. The results strongly suggested that Encephalitozoon should be taken into consideration, when DNA isolated from larval E. multilocularis is analyzed.
BACKGROUND: Arterial ketone body ratio (acetoacetate/3-hydroxybutyrate, AKBR) has been reported to be a useful tool for the estimation of liver functional reserve, but a more recent report has cast doubt on the clinical significance of this redox theory. Furthermore, the effect of a diminution of liver functional reserve on AKBR has not been documented in chronic liver disease. METHODS: AKBR was measured in normal control subjects (n = 10), heavy alcohol drinkers (n = 19), patients with chronic hepatitis (n = 18) and patients with liver cirrhosis (n = 25). RESULTS: Though AKBR was lower in heavy alcohol drinkers (1.66 +/- 0. 82) than in the other noncirrhotic groups (1.97 +/- 0.93 in normal control subjects, 2.25 +/- 1.11 in patients with chronic hepatitis), this discrepancy did not reach a level of significance. AKBR in patients with liver cirrhosis (1.18 +/- 0.52) was significantly lower than that in normal controls (p < 0.01). AKBR in Child's class A, Child's class B, and Child's class C was 1.20 +/- 0.60, 1.07 +/- 0.56, and 1.27 +/- 0.45, respectively, and there were no significant differences among them. CONCLUSION: AKBR may be parallel to liver mitochondrial redox potential and hepatic functional reserve to some extent, but it does not appear to be an accurate parameter for their estimation.
Intracellular localization of 73,000 and 72,000 dalton heat shock proteins (HSP73/72) in HeLa cells that were heat shocked or treated with chemical stressors was investigated using indirect immunofluorescent staining. The antiserum used specifically recognized the HSP73/72 in HeLa cells, and HSPs were increased by heating cells at 42 degrees C for 2 or 4 h and by prior treatment with chemical stressors (sodium arsenite, cadmium chloride, 8-hydroxyquinoline and ethanol). There was diffuse cytoplasmic staining at 37 degrees C, whereas nucleoli were stained brightly when cells were heated at 42 degrees C for 2 h. This rapid accumulation of HSP73/72 in the nucleoli was not inhibited by cycloheximide (50 micrograms/ml). Translocation of HSPs to the nucleoli was specific for heat because no translocation was induced by treatment with chemical stressors. When the cells were returned to 37 degrees C after heating, the HSPs in their nucleoli disappeared rapidly and diffuse cytoplasmic staining was present after 6-9 h. Our results suggest that the transient accumulation of HSP73/72 in HeLa cell nucleoli that is induced by heat shock is not correlated with the development of thermotolerance obtained in other cell systems.
1. Therapeutic effects of a 5-HT2 receptor antagonist sarpogrelate on microalbuminuria and thromboxane (TX)A2 biosynthesis were examined in non-insulin-dependent diabetes mellitus (NIDDM) patients. 2. In protocol I, the ankle-brachial pressure index (API; an indicator of peripheral blood flow) and urinary albumin excretion (UalbV; an indicator of renal function) were determined in 42 NIDDM patients who had been treated with 300 mg/day sarpogrelate for 8 weeks. In an analysis of the results, the NIDDM patients were divided into four groups based on the severity of either vasculopathy or nephropathy as follows: group A, API < 0.9, UalbV > or = 100 mg/day; group B, API < 0.9, UalbV < 100 mg/day; group CAPI > or = 0.9, UalbV > or = 100 mg/day; and group D, API > or = 0.9, UalbV < 100 mg/day. 3. In protocol II, 10 NIDDM patients with UalbV values > 100 mg/day were divided into two groups to further confirm the effect of sarpogrelate on albuminuria: group E, the sarpogrelate treatment group (n = 5); and group F, the no treatment group (n = 5). 4. In protocol I, the incidence of a cold sensation in the lower extremities was reduced from 45.2 to 21.4% following sarpogrelate treatment. In patients with UalbV > or = 100 mg/day (groups A and C), UalbV was significantly decreased independent of API, while it did not change in patients with UalbV < 100 mg/day (groups B and D). Plasma TXB2 levels were significantly decreased following sarpogrelate treatment, whereas plasma 6-keto-prostaglandin F1 alpha levels were not. 5. In protocol II, in the sarpogrelate treatment group (group E), albuminuria was significantly improved and both plasma levels TXB2 and urinary TXB2 excretion were significantly decreased. In contrast, in the untreated group (group F), neither plasma levels TXB2 nor urinary TXB2 excretion was changed. 6. In conclusion, microalbuminuria was improved by treatment with the 5-HT2 receptor antagonist sarpogrelate independent of latent vasculopathy. Blockade of 5-HT2 receptors is suggested to be beneficial for the treatment of nephropathy in NIDDM patients. It is possible that the inhibition of TXA2 biosynthesis is involved in the therapeutic effect of 5-HT2 receptor antagonists.
BACKGROUND/AIMS: To investigate the susceptibility of kidneys to ischemia-reperfusion injury under obstructive jaundice. MATERIALS AND METHODS: Bile ducts of male rats were ligated for five days, right kidneys were removed, and vascular clamps were placed across left renal arteries for 30 minutes. RESULTS: Twenty-four hours later, ischemia-reperfusion produced renal injury in jaundiced rats as shown by increased serum creatinine and urea nitrogen levels. Histological observation showed tubular damages. These changes were minimal after ischemia-reperfusion in control rats. Renal thiobarbituric acid reactive substance contents were increased after bile duct ligation, which did not change after ischemia-reperfusion. On the other hand, ischemia-reperfusion produced a significant increase in renal thiobarbituric acid reactive substance contents in control rats. Renal glutathione contents were increased two fold after bile duct ligation and they were significantly decreased by ischemia-reperfusion. CONCLUSIONS: Kidneys in obstructive jaundice appear to be susceptible to ischemia-reperfusion injury. Although protective roles of GSH is suggested, the role of oxygen radicals in this type of renal injury remains to be further elucidated.