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Biomedical subjects

M Sata

Publications and source records attributed to M Sata.

At least 271 records · Page 15Linked to original sources
PubMed1994

Video-assisted thoracoscopic resection of a mediastinal cyst: report of a case.

Video-assisted endoscopic surgery has recently been expanding its potential, which is shown by our report herein describing the case of a 23-year-old woman for whom successful thoracoscopic resection of a mediastinal cystic lesion was carried out. The patient's postoperative course was uneventful with minimal pain and a prompt recovery. Histological examination confirmed that the lesion was a benign cystic teratoma. We believe that video-assisted thoracoscopic surgery will become the standard procedure for most mediastinal cystic lesions in the future.

Adult↗
PubMed1994

Cultured rat hepatic sinusoidal endothelial cells express intercellular adhesion molecule-1 (ICAM-1) by tumor necrosis factor-alpha or interleukin-1 alpha stimulation.

This study investigated the expression of intercellular adhesion molecule-1, a leukocyte adhesion molecule, on cultured rat hepatic sinusoidal endothelial cells during stimulation with tumor necrosis factor-alpha or interleukin-1 alpha. Using immunoelectron microscopy and the immunogold technique against intercellular adhesion molecule-1, gold particles were shown to increase significantly on the surface of sinusoidal epithelial cells treated with tumor necrosis factor-alpha (100 U/ml) or interleukin-1 alpha (10 U/ml) for 8 h compared with unstimulated cells. In addition, semi-quantitative analysis of intercellular adhesion molecule-1 on the sinusoidal endothelial cells was performed by cytofluorometer. Even without stimulation, intercellular adhesion molecule-1 was weakly expressed. However, 8 h after tumor necrosis factor-alpha or interleukin-1 alpha treatment, the expression of intercellular adhesion molecule-1 on cells was increased in a dose-dependent manner. Kinetic analysis showed that the expression of intercellular adhesion molecule-1 on sinusoidal endothelial cells treated with these cytokines increased gradually from the beginning of stimulation to 24 h. These findings suggest that hepatic sinusoidal endothelial cells may mediate the direct interaction between leukocytes and sinusoidal endothelial cells by expressing leukocyte adhesion molecules such as intercellular adhesion molecule-1.

Animals↗
PubMed1994

Ultrastructure of the intracellular membranous system of rat hepatocytes in intrahepatic cholestasis induced by phalloidin.

To investigate the effect of a thickened pericanalicular ectoplasm in tubulovesicular transport and biliary excretion, we examined the ultrastructure of the intracellular membranous system in rat hepatocytes with and without phalloidin treatment, by transmission electron microscopy and scanning electron microscopy combined with the Aldehyde prefix Osmium-Dimethyl Sulfoxide-Osmium method. Hepatocytes possessed elaborate networks of tubules around bile canaliculi, and some of them extended to the bile canaliculi in control rats. Vesicles were also present around the bile canaliculus. Treatment of rats with phalloidin produced a thick pericanalicular ectoplasm around the bile canaliculus visualized by transmission electron microscopy, and the density of vesicles (p < 0.001) and tubules (p < 0.001) within 0.5 microns around the bile canaliculus significantly decreased in phalloidin-treated rats. The number of lysosomes in hepatocytes apparently increased in phalloidin-treated rats; however, they were rarely observed around the bile canaliculus. The Aldehyde prefix Osmium-Dimethyl Sulfoxide-Osmium method produced an organelle-free space around the bile canaliculus by removing the thick pericanalicular ectoplasm in scanning electron microscopic examination, and the thickened pericanalicular ectoplasm inhibited the approach of intracellular membranes to the canalicular membrane in the transmission electron microscopic examination. In some pathological cholestatic conditions, the thickened pericanalicular ectoplasm may inhibit not only bile canalicular contraction but also biliary excretion of substances, which is mediated by the tubulovesicular transport system.

Animals↗
PubMed1994

The extracellular matrix in hepatocellular carcinoma shows different localization patterns depending on the differentiation and the histological pattern of tumors: immunohistochemical analysis.

This study investigated cells producing type I, III, and IV collagens, laminin, and fibronectin, the major components of the extracellular matrix, and compared their localization patterns in relation to the grade of tumor differentiation and the histological pattern of hepatocellular carcinoma. Type I, III, and IV collagens, laminin, and fibronectin were produced by tumor, endothelial, and Ito cells. Regarding their localization pattern in relation to the histological pattern of tumors, although the extracellular matrix was present in the subendothelial spaces of sinusoids in every histological pattern, the localization of these components in the intercellular spaces of tumor cells was most marked in hepatocellular carcinoma with a compact pattern. These results suggest that the extracellular matrix produced by tumor, endothelial, and Ito cells is deposited in appropriate positions in hepatocellular carcinoma to sustain the tissue structure showing different histological patterns. In relation to the grade of tumor differentiation, in most cases, Type I, III, and IV collagens and fibronectin were present in the subendothelial spaces of sinusoids and the intercellular spaces of some tumor cells, while little laminin was observed in well-differentiated small hepatocellular carcinoma (less than 10 mm diameter). In undifferentiated hepatocellular carcinoma, little extracellular matrix was observed, except around vessels. These results suggest that sinusoidal capillarization may not yet have occurred in the early stage of hepatocarcinogenesis, although it develops as the tumors increase in size and the tumor cells dedifferentiate. In undifferentiated hepatocellular carcinoma, tumor cells are too atypical to produce each extracellular matrix component.

Adult↗
PubMed1994

Long-term graft survival rate of zero-mismatch kidney transplants for HLA-DRB1.

The study of a two-locus association between HLA-B and -DRB 1 revealed a significant 43 linkage disequilibrium. Donor-recipient HLA-DRB1 was determined by these 43 linkages. Zero-mismatch for HLA-DRB1 had a significant effect on the graft survival rate in living related and cadaver transplants. The 5-year graft survival rate was 94% in the zero-mismatch group for HLA-DRB1, 96% for related transplants, 92% for cadaver cases, and 94% in HLA identical siblings. A statistically significant difference was found between the zero-mismatch group for HLA-DRB1 and mismatch groups for HLA-DRB1 or HLA-DR (P < 0.01). The zero-mismatch group for HLA-DRB1 had mismatches for HLA-A and/or HLA-B in 46 of 70 cases (66%). No significant differences in the rejection rate was observed between zero-mismatch and mismatch cases for HLA-A and/or -B in the zero-mismatch group for HLA-DRB1. In the second step, genotyping was conducted in 118 cases. The 5-year graft survival rate was 93% in the zero-mismatch group for HLA-DRB1 and 86% in mismatch group (not a significant difference). We concluded that zero-mismatch transplant for HLA-DRB1 had a better long-term graft survival rate regardless of HLA class I.

Cyclosporine↗
PubMed1994

A patient with hepatic granuloma formation and angiotensin-converting enzyme production by granuloma cells during clinical relapse of hepatitis A.

Elevation of the serum angiotensin-converting enzyme (sACE) level and hepatic granulomas were found during a clinical relapse in a 22 year old patient with acute viral hepatitis type A (AVH-A). The serum transaminase level and sACE level remained high for more than 6 months. In the biopsied specimen of the liver, fibrous rings of granulomas composed of collagen types I, III, and V were observed. Furthermore, the localization of ACE was visible in the rough endoplasmic reticulum of epithelioid cells of granulomas in the liver under electron microscopy using the indirect immunoperoxidase method. These results suggest that granuloma cells in the liver caused by hepatitis A may be involved in ACE production. In addition, other diseases associated with the presence of granulomas in the liver, such as lymphoma, cytomegalovirus infection, visceral leishmaniasis, and lupoid hepatitis, were ruled out. However, the hepatic granulomas disappeared with the healing of AVH-A. In this regard, the present case is considered to be one of the very few cases of hepatic sarcoidosis.

Adult↗
PubMed1994

Morphological observation on extrahepatic bile duct of golden hamsters fed a lithogenic diet: histochemical, ultrastructural and cell kinetic studies.

Cholelithiasis is often accompanied with disorders of the extrahepatic bile duct and pancreas. However, studies on changes of the extrahepatic bile duct in cholecystolithiasis have not shown this clearly. We therefore investigated sequential histologic changes, mucous secretion and DNA synthetic activity of the extrahepatic bile duct epithelium in cholecystolithiasis. Serial changes in the mucosal epithelial cells of the extrahepatic bile duct in golden hamsters treated with a lithogenic diet were examined by light and electron microscopy and an ultrastructural quantitative technique. In addition, epithelial cell kinetics were studied using bromodeoxyuridine (BrdU). After the 2nd week of diet, the extrahepatic bile duct showed an increase in goblet cells of the mucosal epithelium, a large number of secretory granules in the upper nuclear area of the epithelial cells and an increase in the BrdU-labeling index compared with the controls. These findings indicate that mucous secretion and cell turnover were enhanced in the mucosal epithelial cells of the extrahepatic bile duct in cholelithiasis, suggesting that the epithelial cells of the bile duct were protected and regenerating.

Animals↗
PubMed1994

ADP inhibits the sliding velocity of fluorescent actin filaments on cardiac and skeletal myosins.

We studied the effect of MgADP on the mechanical interaction of actomyosin in cardiac and skeletal muscles using an in vitro motility assay. The sliding velocities of fluorescently labeled actin filaments on rat cardiac and skeletal myosins were measured at various MgATP and MgADP concentrations. The filament velocity depended on MgATP concentration according to classic Michaelis-Menten kinetics with apparent Michaelis constants (Km) of 43 and 137 mumol/L and maximum velocity of 5.6 and 8.6 microns/s for cardiac and skeletal myosins, respectively. The presence of 2 mmol/L MgADP decreased the filament velocity and shifted the substrate concentration dependence of the velocity toward higher MgATP concentrations, yielding the inhibition constants of 194 and 478 mumol/L for cardiac and skeletal myosins, respectively. The activation energies determined by the temperature dependence of the velocity were 61 and 83 kJ/mol for rat V1 and rabbit cardiac myosins, which were similar to those of the dissociation rate constant of actomyosin-ADP complex reported in a solution study. The inhibition of the velocity by MgADP can be explained by the crossbridge scheme in which MgADP competes with MgATP for the substrate site on myosin molecules. In cardiac myosin, addition of a concentration of MgADP as low as 25 mumol/L significantly inhibited the velocity in the presence of 2 mmol/L MgATP, suggesting that increased intracellular MgADP may reduce the rate of crossbridge detachment, resulting in a decreased ATP consumption and an increased economy of force production under ischemic conditions. The present results support the idea that MgADP may be a physiologically important modulator of contraction in cardiac muscle.

Actins↗
PubMed1994

Asialoglycoprotein receptor function of hepatocytes in patients with autoimmune hepatitis.

To assess whether the hepatocyte asialoglycoprotein receptors are affected in patients with autoimmune hepatitis, the function of the hepatocyte asialoglycoprotein receptor was investigated in patients with autoimmune hepatitis or chronic hepatitis C. A new radionuclide liver imaging technique, Technetium-99m diethylenetriamine-pentaacetic acid-galactosyl human serum albumin, was applied to evaluate the function of the receptor. A Receptor Index (LHL 15) was calculated by dividing the radioactivity of the liver region-of-interest (ROI) by that of the liver plus heart ROI 15 min after radiolabeled ligand injection. Serum albumin, prothrombin time, hepaplastin test and plasma retention rate of indocyanine green at 15 min were not significantly different between patients in the autoimmune hepatitis group and chronic hepatitis C group. In addition, the Receptor Index of patients with autoimmune hepatitis, in whom the asialoglycoprotein receptor is a candidate target antigen for autoimmune response, was similar to that of patients with chronic hepatitis C. These results indicate that the hepatocyte receptor for asialoglycoproteins is not affected in patients with autoimmune hepatitis.

Adult↗
PubMed1994

Function of asialoglycoprotein receptor of hepatocytes in patients with Wilson's disease.

The function of hepatocyte asialoglycoprotein receptors was analyzed in normal subjects, in patients with Wilson's disease and in patients with chronic hepatitis C. A new radionuclide liver imaging, using Technetium-99m diethylenetriamine-pentaacetic acid-galactosyl human serum albumin, was applied to evaluate the function of the receptor, and a Receptor Index, LHL 15, which was calculated by dividing the radioactivity of the liver region-of-interest (ROI) by that of the liver plus heart ROI at 15 min after the radiolabeled ligand injection, was evaluated. The values were similar between the patients with Wilson's disease and patients with chronic hepatitis C. Hepatocyte receptors for asialoglycoproteins were not affected specifically in patients with Wilson's disease, suggesting that the defect in patients with Wilson's disease involves steps other than receptor-mediated endocytosis of asialoceruloplasmin via asialoglycoprotein receptor.

Adult↗
PubMed1994

[Serum HCV-RNA for evaluation of interferon-readministration to the former non responders in chronic hepatitis C].

We investigated the efficacy of retreatment with interferon in patients with chronic hepatitis C who were non responders to the initial interferon treatment. The results were as follows: 1) The effective rate was very low and 2 of the 16 responded to the 2nd treatment. 2) Serum HCV-RNA levels before retreatment with interferon were compared among the 4 responders and the 13 non responders to interferon and it was significantly lower in the 4 responders. 3) HCV-genotypes may be useful to predict the efficacy of interferon readministration.

Adult↗
PubMed1994

Clinical evaluation of four cases of acute viral hepatitis complicated by pure red cell aplasia.

Four patients with acute viral hepatitis complicated by pure red cell aplasia were clinically evaluated. Two patients with hepatitis type A, one with hepatitis type B, and one with posttransfusion non-A non-B hepatitis had pure red cell aplasia. Only the patient with posttransfusion hepatitis was female, and the mean age of the four patients was 37.8 yr (31-51 yr.) The mean interval from the onset of hepatitis to the appearance of pure red cell aplasia was 30.5 days (27-37 days), and the development of hematopoietic disorders coincided with decreases in transaminase levels. Laboratory findings included peak serum glutamate pyruvate transaminase levels of 1305-3160 KU and decreases in the prothrombin time to about 50% in the two patients with hepatitis type A. Pure red cell aplasia was successfully treated by prednisolone or transfusion in all patients.

Acute Disease↗
PubMed1994

Role of serum interleukin-8 and intercellular adhesion molecule-1 in the severity of alcoholic hepatitis.

Among patients with alcoholic hepatitis, three groups were distinguished by histological findings and clinico-pathological features. The aim of this study was to clarify the role of soluble intercellular adhesion molecule-1 (sICAM-1) and interleukin-8 (IL-8) in the development of severe alcoholic hepatitis. The levels of sICAM-1 and IL-8 were well correlated with the severity of liver injuries. The concentrations of serum IL-8 were significantly correlated with the number of polymorphonuclear leukocytes infiltrating the liver. Serial determination of these two markers revealed that IL-8 may be complementary in assessing the severity and prognosis of alcoholic hepatitis.

Adult↗
PubMed1993

Depressed sliding velocity of isolated cardiac myosin from cardiomyopathic hamsters: evidence for an alteration in mechanical interaction of actomyosin.

We measured the relative sliding velocity of cardiomyopathic hamster cardiac myosin on actin cables by using an in vitro motility assay system. We also investigated the relationship between the velocity and both myosin isozyme content and ATPase activity. Cardiac myosin was obtained from cardiomyopathic hamsters (BIO 14.6; B) aged 3, 6, 9, and 18 months and age-matched controls (F1B; F). Long well-organized actin cables of an alga, Nitellopsis, were used for the motility assay. Small latex beads (2 microns in diameter) were coated with purified cardiac myosin. When myosin-coated beads were introduced into an algal cell in the presence of Mg-ATP, myosin interacted with actin and dragged the beads. Active movement of the beads along the actin cables was observed under a photomicroscope and the velocity was measured. The velocity was significantly lower in B than in F for each age group (0.47 vs. 0.71 microns/s at the age of 3 months, p < 0.05; 0.44 vs. 0.88 microns/s at 6 months, p < 0.01; 0.44 vs. 0.67 microns/s at 9 months, p < 0.01; 0.35 vs. 0.52 microns/s at 18 months, p < 0.05). Both Ca(2+)-activated ATPase activity and the percentage of alpha-myosin heavy chain were also lower in B than in F for each age group. When examined for individual specimens, there was a positive correlation between the velocity and both myosin Ca(2+)-activated ATPase activity (r = 0.84) and percentage of alpha-myosin heavy chain (r = 0.83). These data points of both control and cardiomyopathic hamsters were distributed near the regression line obtained from control and thyroxine-treated rabbits reported previously. The present results indicate that the difference in mechanical properties between control and cardiomyopathic cardiac myosin is attributed to isozyme redistribution and not to a qualitative change in each myosin molecule.

Actomyosin↗
PubMed1993

Ito cell contraction in response to endothelin-1 and substance P.

The contractile response of cultured Ito cells to endothelin-1 and substance P was examined. Ito cells were obtained from rat liver by perfusion with collagenase, followed by separation through centrifugal elutriation, and were cultured for 24 hr. The area of the Ito cells was measured after treatment with endothelin-1 or substance P at various concentrations in the culture medium. The area of the cells decreased dose dependently after treatment with endothelin-1 or substance P. The area of Ito cells before addition of interleukin-1 or substance P was defined as 100%. The area of the cells after treatment with endothelin-1 or substance P medium was expressed as the percentage against the area before treatment with endothelin-1 or substance P. The percentage in area after treatment with 200 nmol/L endothelin-1 was as follows: 81% +/- 13% at 30 min, 77% +/- 15% at 60 min, 87% +/- 15% at 120 min and 99% +/- 18% at 180 min. The maximal decrease in area occurred at 60 min after treatment. The percentage values for 200 nmol/L substance P were as follows: 88% +/- 15% at 10 min, 95% +/- 17% at 30 min and 101% +/- 17% at 60 min. The maximal decrease in area was noted at 10 min. Thus Ito cells contracted in response to treatment with endothelin-1 or substance P. The mode of the extent and onset of the contraction was different for the two peptides. These findings suggest that Ito cells are involved in the regulation of the hepatic sinusoidal microcirculation.

Animals↗
PubMed1993

The relationship between LeY antigen and the therapeutic efficacy of interferon in chronic hepatitis C.

The expression of LeY antigen (Fuc alpha 1-->2Gal beta 1-->4 [Fuc alpha-->3] GlcNAc beta 1-->R), recognized by the monoclonal antibody BM-1, was studied in peripheral blood T-lymphocyte subpopulations in patients with viral hepatitis, and in liver tissue of patients with acute viral hepatitis. The relationship between the expression of LeY antigen on peripheral blood T-lymphocytes and the effects of interferon (IFN) therapy for chronic hepatitis type C were also evaluated. LeY antigen is not markedly expressed in B or T-lymphocytes of healthy individuals. However, it was strongly expressed in CD8 and CD4 T-lymphocytes in patients with viral hepatitis. In the acute phase of acute viral hepatitis, the expression of LeY antigen was more markedly expressed on peripheral CD8 T-lymphocytes than on CD4 T-lymphocytes. In chronic hepatitis type B and type C, it was significantly expressed more often on CD4 T-lymphocytes. In the liver tissues of patients with acute viral hepatitis, LeY antigen was expressed on hepatocytes and infiltrating lymphocytes. IFN therapy for chronic active hepatitis type C proved most effective when LeY antigen was more markedly expressed on the patient's CD4 and CD8 peripheral blood T-lymphocytes before treatment. Further studies are needed to clarify the relationship between the mechanisms of hepatic cell injury and LeY antigen.

Adult↗
PubMed1993

The endothelin-1 binding site in rat liver tissue: light- and electron-microscopic autoradiographic studies.

BACKGROUND: Endothelin (ET) is known as a vasoconstrictive substance. The receptors for ET have been shown in various organs. However, little is known about the endothelin-1 (ET-1) binding sites in the liver. The aim of this study was to examine ET-1 binding sites in the liver. METHODS: ET-1 binding sites in rat liver were studied in vivo by light- and electron-microscopic autoradiography using 125I-ET-1. RESULTS: Light-microscopic autoradiographic observation revealed strong localization of grains in the sinusoidal lining cells of the hepatic lobule and a small number of grains in the luminal space of the portal vein and central vein. In the hepatic lobule, more grains were located in the periportal region, and the quantity tended to decrease from the midzonal to the pericentral region. Electron-microscopic autoradiographic observation revealed grains in Ito cells and in the endothelial cells of the portal vein, central vein, and hepatic sinusoids. CONCLUSIONS: These results suggest that ET-1 acts on Ito cells and on endothelial cells of the hepatic sinusoids, portal vein, and central vein and that its action is related to hemodynamics of the liver, particularly regulation of the microcirculation of the hepatic sinusoids.

Animals↗