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Biomedical subjects

M Sata

Publications and source records attributed to M Sata.

At least 289 records · Page 16Linked to original sources

Serum hyaluronate reflects hepatic sinusoidal capillarization.

BACKGROUND: Most of circulating hyaluronate has been commonly degraded by hepatic sinusoidal endothelial cells (SECs). In hepatic sinusoidal capillarization, SECs morphologically change and also seem to decrease hyaluronate degradation. This work expands on the relationship between serum hyaluronate levels and changes in hepatic SECs accompanying hepatic sinusoidal capillarization. METHODS: Serum hyaluronate levels were determined using an enzyme binding assay system. Liver biopsy specimens were collected to examine basement-membrane formation, the localization of Weibel-Palade bodies, and the localization of factor VIII-related antigen (FVIIIRAg) in SECs. RESULTS: Serum hyaluronate levels increased with the progression of liver disorder, being high in all patients with liver cirrhosis. Patients showing markedly high serum hyaluronate levels, 200 ng/mL or more, had liver cirrhosis involving the SECs, which showed basement-membrane formation, Weibel-Palade bodies, and FVIIIRAg and closely resembled vascular endothelial cells. CONCLUSIONS: Measurement of the serum hyaluronate concentration allows the evaluation of morphological and functional changes that occur in SEC accompanying hepatic sinusoidal capillarization in various liver disorders. The findings also suggest that patients with high serum hyaluronate levels, 200 ng/mL or more, have liver cirrhosis with typical hepatic sinusoidal capillarization formed by SECs containing FVIIIRAg.

Adolescent↗

Chronic hepatitis C in alcoholic patients: studies with various HCV assay procedures.

Chronic hepatitis (CH) is one of the features of alcoholic liver disease (ALD). The role of hepatitis C virus (HCV) infection was investigated in 50 alcoholic patients with CH, employing various types of HCV antibody. All patients had a drinking history of more than 80 g/day of ethanol and the diagnosis of CH was made by liver histology within 2 weeks of abstinence. We assayed serum HCV using C100-3 antibody (Ortho EIA and RIA), the second generation (HCV-2nd) (DAINABOT EIA and PHA), and we also examined HCV-RNA by PCR. The positive rate of C100-3 antibody was 56% by EIA and 66% by RIA. The HCV-2nd was much higher; 80% and 82% by EIA and PHA, respectively. The HCV-RNA was positive in 82% of patients. The positive rate for either of the HCV markers was 92% (46/50). In patients positive for C100-3, serum aminotransferase levels were still elevated even after abstinence and most of them showed chronic active hepatitis by liver histology. Follow-up liver biopsies showed histological progression even after abstinence. On the other hand, in some patients positive only for HCV-2nd and/or HCV-RNA, serum aminotransferase levels were normalized and histological improvement was observed soon after abstinence. These results suggest that histological determined CH in alcoholics is attributed mainly to the infection of HCV, HCV plays an important role in the histological deterioration after abstinence, and that the presence of C100-3 antibody reflects the activity of liver disease caused by HCV.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Roles of the splenic cytokines and arachidonic acid metabolites in severe hepatic injury after lipopolysaccharide injection in chronically alcohol-fed rats.

We examined the early changes after lipopolysaccharide (LPS) injection in chronically alcohol-fed rats with or without splenectomy. Administration of 2 mg/kg body weight LPS caused severe hepatic injury. The plasma aspartate aminotransferase (ASAT) activity was significantly higher in sham-operated rats 8 hr after LPS injection than in splenectomized rats. The plasma tumor necrosis factor (TNF) activity was also significantly higher 1 hr after LPS injection in sham-operated rats than in splenectomized rats. The plasma thromboxane (TX) B2/6-keto-prostaglandin (PG) F1 alpha ratio increased in sham-operated rats after LPS injection. Therefore, the balance of arachidonic acid metabolites was in a hypercoagulated state in sham-operated rats after the LPS injection. Neutrophil infiltration into liver tissue increased in sham-operated rats after the LPS injection. The cytokines and arachidonic acid metabolites released from the spleen after LPS injection in alcohol-fed rats may play important roles in severe hepatic injury.

Animals↗

Clinical and pathological features, and the mechanism of development in severe alcoholic hepatitis, especially in comparison with acute type fulminant hepatitis.

Among the patients with alcoholic hepatitis, the patients with severe alcoholic hepatitis (SAH) were distinguished by clinical course, laboratory data and histological findings. The aim of this study was to clarify the clinicopathological features, pathological condition and pathogenesis of SAH. Twenty-four SAH patients were compared with 55 patients with acute type fulminant hepatitis (FH) and the other types of alcoholic liver disease. SAH showed a very poor prognosis with a survival rate of 25% and was complicated by multiple organ failure earlier than FH. IgA class lipid A antibody, endotoxin (Et) and tumor necrosis factor-alpha (TNF-alpha) levels in the blood well reflected the pathological condition and severity of SAH. The white blood cell count in the peripheral blood was thought to be the simplest indicator for the prediction of the prognosis of SAH. In conclusion, SAH involves hyper-endotoxemia due to dysfunction of the reticuloendothelial system in the liver, and cytokines including TNF-alpha and neutrophils play an important role in the severity of liver injury.

Adult↗

The significant effect of HLA-DRB1 matching on long-term kidney graft outcome.

Serotyping and genotyping (polymerase chain reaction with sequence-specific oligonucleotide probes method) were conducted on 520 unrelated individuals to determine the linkage disequilibrium of HLA-B and HLA-DRB1. Analyses of 511 kidney transplants (300 related and 211 cadaver recipients) were carried out at 4 transplant centers using the linkage disequilibrium of HLA-B and HLA-DRB1 established previously. All transplant recipients received CsA immunosuppression and were transplanted from June 1983 to December 1991. There were 51 significant linkages formed between HLA-B and HLA-DRB1 alleles (P < 0.05). DRB1-compatible transplants experienced a comparable 5-year graft success rate of 94% as did the HLA-identical recipients with a 100% 5-year success rate. However DRB1-incompatible recipients displayed a significantly reduced 5-year graft survival rate of 73% (73% vs. 94% P < 0.01). The 5-year graft survival rate of HLA-DR-incompatible recipients of 71% was compatible to the 73% for HLA-DRB1-incompatible recipients. No variation of rejection rate for DRB1-compatible grafts was seen in any of the 4 transplant centers. The results also indicated that HLA-DRB1 compatibility was essential for optimal success rate, regardless of HLA class I mismatches. The overall conclusion was that matching for HLA-DR was important to achieve optimal kidney graft survival on the molecular level but not on the serotyping level.

Alleles↗

A study of erythrocyte C3b receptors (E-CR1) in patients with acute viral hepatitis.

Erythrocyte C3b receptors (E-CR1) were assayed by ELISA in 16 patients with acute viral hepatitis. In 13 patients with hepatitis type A, type B, or type non-A non-B, the E-CR1 level was significantly lower in the acute phase than in healthy controls, and recovered in the convalescent phase. The E-CR1 levels in 3 patients with non-A, non-B hepatitis remained below the mean level of the healthy controls. These findings suggest that the E-CR1 level fluctuates in acute viral hepatitis, and that it continues to be reduced in some patients with non-A non-B acute hepatitis.

Acute Disease↗

Dynamic interaction between cardiac myosin isoforms modifies velocity of actomyosin sliding in vitro.

To study the functional significance of cardiac isomyosin heterogeneity, active sliding of actin-myosin was studied using two different types of in vitro motility assay systems: (1) a sliding actin filament assay, in which fluorescently labeled actin filaments were made to slide on a myosin layer attached to a glass coverslip, and (2) a myosin-coated bead assay, in which myosin-coated latex beads were made to slide on actin cables of an alga. Two different isomyosins were obtained from 3-week-old (V1) and hypothyroid (V3) rat hearts and were mixed to form solutions with various mixing ratios [V1/(V1 + V3)]. For these myosin mixtures, both ATPase activity and sliding velocity of actin-myosin were determined. As the relative content of V1 increased, both ATPase activity and velocity increased. However, in contrast to the linear relation between the mixing ratio and ATPase activity, the relation between the mixing ratio and sliding velocity was sigmoid, suggesting the existence of mechanical interaction between different isomyosins. To clarify the nature of this interaction, sliding velocity was measured for mixtures of V1 and p-N,N'-phenylene-dimaleimide-treated V1 myosin (pPDM-M). A convex relation was observed between the relative content of pPDM-M and velocity. Because pPDM-M is known to form a noncycling and weakly bound crossbridge with actin, it is expected to exert a constant internal load on V1, in contrast to the actively cycling V3. In conclusion, in actomyosin sliding, different isomyosins mechanically interact when they coexist. The interaction may be a dynamic one that cannot be explained by a simple load effect.

Actomyosin↗

Fatal acute hepatitis B virus infection while receiving immunosuppressants after renal transplantation.

A 47-year-old man with acute hepatitis B virus (HBV) infection who had been receiving immunosuppressants after renal transplantation developed progressive liver failure. During the clinical course (approximately 7 months), anti-HBc IgM antibody and HBV-DNA polymerase levels remained high, but the serum alanine aminotransferase (ALT) level was consistently less than 150 K.U. Histopathologic examination of the liver showed submassive hepatic necrosis without significant inflammation accompanied by marked fibrosis. Most hepatocytes showed strong nuclear expression of HBc antigen by immunohistochemical staining and electron microscopy revealed numerous intranuclear core-like particles. Hepatitis B virus infection in immunosuppressed individuals occasionally insidiously progresses, resulting in liver failure. The clinical course of such patients thus merits close scrutiny.

Acute Disease↗

Incidence of antibodies to hepatitis C virus in patients undergoing chronic dialysis and CAPD.

We measured antibodies to hepatitis C virus (anti-HCV) in patients who were receiving hemodialysis or continuous ambulatory peritoneal dialysis (CAPD). Sixty seven patients (28%) were anti-HCV positive. The anti-HCV positive frequency increased with the time of treatment with dialysis, the frequency being 50% with a dialysis period > or = 10 years. The frequency of anti-HCV positivity was similar in patients with a history of blood transfusion (48/152, 32%) and in those without this history (19/89, 21%, p > 0.05). Therefore, in addition to blood transfusion, there may be other routes of HCV infection associated with long-term dialysis. Chronic liver disease was observed in 31% (21/67) of the patients positive for anti-HCV but in only 6% (11/174) of the negative patients (p < 0.01). HCV seems to be important as a cause of chronic liver disease in dialysis patients.

Adult↗

Evaluation of first- and second-generation assays for detection of antibody to hepatitis C virus in non-A, non-B chronic liver diseases--evaluation of 1st and 2nd-generation assays in NANBH.

The positive rates of the second-generation enzyme-linked immunoassay (2nd-generation assay), and two first-generation immunoassays (C100-3 and KCL-163 assay) to test for anti-HCV antibodies in the serum of patients with non-A, non-B chronic liver disease were determined. The clinical usefulness of these assays was also evaluated. The group positive for the 2nd-generation assay alone was compared with that positive for the 2nd-generation and C100-3 assays with respect to the serum GPT levels determined simultaneously with the antibodies. The latter group showed slightly higher GPT levels. These findings suggest that the 2nd-generation assay is useful for the diagnosis of hepatitis C, and that C100-3 and KCL-163 assays are useful indicators of the activity of hepatic disorders.

Adult↗

Hydroxyl radical generation and membrane fluidity of erythrocytes treated with lipopolysaccharide.

The effect of lipopolysaccharide (LPS) and/or bile acids on rat erythrocyte membranes was studied in vitro. Addition of LPS isolated from E. coli (J5 mutant) into the erythrocyte resulted in the decrease of membrane fluidity as determined by spin labelling using electron paramagnetic resonance (EPR). This was accompanied by membrane fragility. It was found that hydroxyl radicals were generated from erythrocytes treated with LPS by using DMPO spin trapping. However, pretreatment of erythrocytes with taurine-conjugated bile acids was found to modify the membrane response induced by LPS. Taurocholic acid (TCA) and tauroursodeoxycholic acid (TUDCA) prevented the decrease of membrane fluidity induced by LPS, and, as a result, the membrane integrity was maintained although no significant changes were observed in the amount of hydroxyl radicals produced by LPS addition. However, taurochenodeoxycholic acid (TCDCA) exhibited little beneficial effect on the dynamic properties and the function of the erythrocyte membranes, although the hydroxyl radical declined markedly in the erythrocytes. Therefore, it is suggested that TCA and TUDCA have a protective effect against LPS-induced membrane fragility by modulating membrane fluidity.

Animals↗

Bacterial infection in cirrhosis, with and without hepatocellular carcinoma.

OBJECTIVE: The extent and type of bacterial infection occurring with liver cirrhosis has remained unknown. Further, while hepatocellular carcinoma (HCC) is known to occur mainly in patients with liver cirrhosis, no report has yet investigated the incidence of bacterial infection in HCC. The purpose of the present study was to establish the prevalence of bacterial infection in patients with HCC. METHODS: We have retrospectively investigated all 1140 patients with hepatic cirrhosis and/or HCC for any incidence of bacterial infection. RESULTS: The incidence of bacterial infection was found to be 15.4%, in 740 patients with HCC. This was approximately equal to the incidence of bacterial infection in 400 patients with cirrhosis without HCC, which was found to be 15.3%. When the severity of cirrhosis was graded according to Child-Pugh classification, the incidences of bacterial infection in Child-Pugh class A, class B, and class C were 3.3%, 11.1%, and 31.2%, respectively, in cirrhosis, and 2.3%, 9.1% and 25.6% in HCC. The incidence of bacterial infection increased with the severity of cirrhosis and severe bacterial infections occurred in Child-Pugh class B and C patients. CONCLUSION: The data suggest that the susceptibility of HCC patients to bacterial infection is mainly related to the underlying cirrhosis and not to the HCC.

Bacterial Infections↗

[Cardiac contractile proteins].

Structure and function of cardiac contractile proteins were summarized in connection with the pathophysiology of the heart muscle. Myosin is a large molecule consisting of two heavy chains and four light chains. Functional domains including ATP binding and actin binding sites reside in heavy chain. Heavy chain has two functionally distinct isoforms and their relative content changes in response to various pathological stimuli. The structure of myosin heavy chain also plays an important role in pathogenesis of familial hypertrophic cardiomyopathy. Another component of contractile machine is the F-actin, polymer of actin molecules. Actin is also a polymorphic protein and its expression changes under various conditions. However, the functional significance of actin polymorphism is yet to be determined.

Actins↗

Biliary copper excretion in acutely and chronically copper-loaded rats.

Biliary copper excretion was examined in rats with acute, continuous and chronic copper loads. Copper was excreted into bile, and the concentration peaked 40 min after a venous injection of copper sulfate (127 ng/gm body weight). The excretion was significantly inhibited by colchicine. Therefore some copper may be transported in hepatocytes by a vesicular pathway and excreted into bile. Biliary copper output increased over time and reached a plateau 180 min after a continuous venous infusion of copper sulfate (318 ng/gm body weight/hr) had started, when the concentration of copper in bile was much higher than that in plasma; the bile/plasma ratio of copper concentrations was 4.32 +/- 0.46. These data support the idea that copper transport involves a specific uptake and transport system. In chronically copper-loaded rats, hepatic copper content was significantly increased compared with controls, and reaction products for copper were observed in hepatocyte granules by light microscopic examination with p-dimethylaminobenzylidene rhodanine stain. The number of lysosomes in hepatocytes increased and the shape changed. In chronically copper-loaded rats the number of tubular lysosomes was very high. However, other organelles appeared to be normal. In these rats biliary excretion of not only copper but also acid phosphatase, a lysosomal enzyme, was significantly greater than the control. Therefore hepatocyte lysosomes may play an important role in biliary copper excretion. Furthermore, when biliary lysosomal excretion increases, the tubular lysosomes actively participate in this excretion.

Acid Phosphatase↗

Clinical significance of serum HBVDNA detected by the PCR method.

Changes in serum HBVDNA and their relationship to the prognosis following interferon (IFN) therapy were examined by the polymerase chain reaction (PCR) in 4 patients with chronic hepatitis B infection undergoing IFN therapy. The disappearance of HBVDNA was confirmed by the PCR methods in 3 out of 4 patients who showed favorable subsequent courses. The remaining patient was positive for HBVDNA despite the disappearance of the HBe antigen. In this patient, the hepatitis recurred, and was accompanied by a persistent hepatic disorder. The PCR assay was also carried out to clarify the involvement of the hepatitis B virus in 12 patients who were positive for the HBe antibody and who showed fluctuating transaminase levels. The PCR method revealed that all 12 patients were positive for HBVDNA. These findings indicate the clinical usefulness of the PCR assay for hepatitis B virus infection.

Adolescent↗

[Combined use of chest X-rays and body mass index to predict pulmonary hemodynamics in patients with chronic obstructive pulmonary disease].

A study was undertaken to determine whether measurements of radiological indices from chest X-rays and body mass index (BMI) were useful in predicting pulmonary artery hypertension. Measurements of the cardiothoracic ratio (CTR) as well as right descending pulmonary artery diameter (RDPA) and BMI were made in 27 patients with chronic obstructive pulmonary disease (COPD). Mean pulmonary arterial pressure (mPA) correlated with CTR, RDPA and BMI. Multiple regression analysis gave the useful equation: predicted mPA = -3.523 + 0.196xBMI + 0.110xCTR + 0.786xRDPA (r = 0.704, p < 0.002). Fifteen patients were found to have pulmonary hypertension, defined as mPA > or = 20 mmHg. The sensitivity of CTR and BMI were 86.7%. The specificity of BMI was 83.3%. These results suggest that the measurements CTR, RDPA and BMI may be useful in screening for pulmonary hypertension in patients with COPD.

Aged↗