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Biomedical subjects

T Tsuji

Publications and source records attributed to T Tsuji.

At least 19 recordsLinked to original sources
PubMed1992

Differential expression of apoptosis-related Fas antigen on lymphocyte subpopulations in human peripheral blood.

The Fas Ag is a newly defined cell-surface molecule that may mediate apoptosis. The antibody against Fas Ag can induce the apoptotic cell death in cell lines expressing this Ag. PBL subpopulations at various ages were here examined for Fas expression by two-or three-color flow-cytometric analyses using anti-Fas mAb. It was found that Fas Ag was appreciably detected on a proportion of T and B cells, whereas its expression was absent for NK cells. For CD4+ and CD8+ T cells, Fas Ag was expressed preferentially on CD45RO+ (memory or previously activated) populations, but not on CD45RO- naive ones. TCR-gamma/delta+ T cells, especially their CD45RO+ subsets, also expressed Fas Ag. Expectably, neonatal T cell subpopulations, most of which had the naive (CD45RO-) phenotype, expressed little Fas Ag. Fas-expressing B cells dominated in surface(s) IgD- populations, but neonatal B cells as well as adult sIgD+ B cells had little Fas Ag. The Fas Ag was inducible after in vitro mitogenic stimulation of naive T and B cells from neonatal blood. These observations suggested that expression of Fas Ag on T and B cells in the peripheral blood might reflect their in vivo Ag-activated status. In contrast to Fas-expressing cultured cell lines, however, viability of in vitro stimulated T and B cells as well as freshly isolated CD45RO+ T cells was not significantly changed after the treatment with anti-Fas mAb, indicating that additional cellular conditions to Fas expression might be required for anti-Fas-induced cell death.

Antigens, Surface↗
PubMed1992

Production of a low molecular weight growth inhibitory factor by adenovirus 12-transformed cells.

Malignant rodent cells transformed by human adenovirus 12 produce a potent cell growth inhibitory factor. The cell growth inhibitory factor inhibits the growth of and DNA synthesis in normal fibroblasts in vitro. Extent of the production of the cell growth inhibitory factor appears to be proportional to that of the malignancy of the transformed cells. C57AT1-AB cells, an adenovirus 12-transformant of C57BL/6 mouse origin, are highly tumorigenic in the syngeneic and allogeneic mice. The cell growth inhibitory factor produced by these cells was characterized for the physicochemical properties; the cell growth-inhibitory activity was quantitatively recovered in the filtrates of YM-2 membrane (M(r) less than 1,000), resistant to the heat treatments at 56 degrees C for 30 min and 100 degrees C for 5 min, and extractable by ethyl acetate under acid-condition. These results suggest that the cell growth inhibitory factor may be lipid or oligopeptides.

Adenoviruses, Human↗
PubMed1992

Regulatory role of GM3 ganglioside in integrin function, as evidenced by its effect on function of alpha 5 beta 1-liposomes: a preliminary note.

Mouse mammary carcinoma mutant cell line FUA169, characterized by high GM3 ganglioside content, was established from parent cell line FM3A/F28-7, which has high LacCer content but no GM3. Although both cell lines showed the same quantity and quality of integrin receptors, FUA169 showed much stronger adhesion to fibronectin (FN)-coated plates than did F28-7. Liposomes containing phosphatidylcholine, cholesterol, alpha 5 beta 1, and a moderate amount of GM3 showed greatly enhanced adhesion to FN-coated plates, but adhesion of similar liposomes containing a large amount of GM3, or no GM3, was much lower. Our results suggest that GM3 regulates integrin receptor function essential for cell adhesion to FN.

Animals↗
PubMed1992

The adjuvant effect of Vibrio cholerae and Escherichia coli heat-labile enterotoxins is linked to their ADP-ribosyltransferase activity.

This study addressed the question of whether the mucosal adjuvant property of cholera toxin (CT) and the structurally closely related Escherichia coli heat-labile toxin (LT) requires the enterotoxic and adenylate cyclase/cAMP activating property of these molecules. Therefore, we investigated the cytotoxic and adjuvant abilities of the enterotoxins and compared the results with those obtained with the non-toxic CT and LT derivatives; recombinant CTB (rCTB) and a mutated LT (mLT), which had a single amino acid substitution in position 112 (Glu----Lys) of the A subunit. Detailed functional studies revealed that, in contrast to the enterotoxins, both rCTB and mLT lacked ADP-ribosylating and cAMP-stimulating abilities. However, similar membrane ganglioside GM1-receptor binding ability of all the putative adjuvants was demonstrated. When the probe antigen, keyhole limpet hemocyanin (KLH), was given perorally together with CT or LT strong gut mucosal anti-KLH immune responses were stimulated, whereas no or very low anti-KLH responses were seen in the groups which received antigen admixed with rCTB or the mLT. Moreover, the specific serum antibody responses to the various immunization protocols closely paralleled the local anti-KLH response in the gut. From these results it appears that the adjuvant mechanism of LT, and probably also of CT, is linked to the ability to ADP-ribosylate and to stimulate cAMP formation. However, this study does not unequivocally rule out other possibilities such as interactions by the A1 fragment of CT or LT with other G-proteins than Gs alpha or events that parallel or precede the effects on the adenylate cyclase/cAMP system. Thus, the levels of ADP-ribosylation and cAMP-induction that are required and the key event or target cell that is responsible for the adjuvant effect of CT and LT remain to be elucidated. Studies are underway to address these issues.

Adjuvants, Immunologic↗
PubMed1992

The protease from Vibrio cholerae nicks arginine at position 192 from the N-terminus of the heat-labile enterotoxin a subunit from enterotoxigenic Escherichia coli.

It was examined where a protease purified from Vibrio cholerae might nick the heat-labile enterotoxin (LT) A subunit from enterotoxigenic Escherichia coli. LT was digested by the protease and contained a fragment which had the same mobility on SDS-PAGE as that of the A1 fragment of LT digested by trypsin. The biological activity of LT by this protease was also identical to that of LT by trypsin. The amino acid sequence of the N-terminus of the A2-like fragment was Thr-Ser-Thr-Gly, which corresponded to the sequence from 193 to 196 of the A subunit. These data suggest that this protease, like trypsin, nicks arginine at position 192 from the N-terminus of the A subunit and that the biological activation of LT by this protease is similar to that by trypsin.

Amino Acid Sequence↗
PubMed1992

Heterogeneity among heat-labile enterotoxins produced by porcine enterotoxigenic Escherichia coli.

The heat-labile enterotoxins (LT) produced by various porcine strains (LTp) of enterotoxigenic Escherichia coli were purified to homogeneity and their molecular properties were compared with each other. By double gel diffusion and rabbit skin permeability test, LTps from WT-1 (LTp-WT-1) and BO-149 (LTp-BO-149) strains were antigenically and biologically identical. By polyacrylamide gel electrophoresis with sodium dodecyl sulfate (SDS), the mobilities of A and B subunits of LTp (BO-149) were identical to those of LTp (WT-1). However, on polyacrylamide gel electrophoresis without SDS, LTp (BO-149) and LTp (WT-1) differed in mobility, suggesting their molecular differences. Though the pI value of the B subunit of LTp (BO-149) was identical to that of LTp (WT-1), the pI value of the A subunit of LTp (BO-149) was higher than that of LTp (WT-1). These data suggest that there is molecular heterogeneity among LTps produced by the two porcine enterotoxigenic Escherichia coli strains.

Animals↗
PubMed1992

Surface glycoprotein of human natural killer cells recognized by wheat germ agglutinin.

We analyzed surface glycoproteins of human natural killer (NK) cells by utilizing lectins. Among the lectins tested, wheat germ agglutinin (WGA) was found to bind preferentially to CD16(Leu11)-positive lymphocytes as determined by two-colour flow cytometry. Analysis of glycoproteins in the lysate prepared from NK cells with sodium dodecyl sulfate (SDS) gel electrophoresis followed by Western blotting and 125I labeled WGA staining revealed that a glycoprotein with an M(r) of 65 kDa was strongly bound to the lectin, but no corresponding glycoprotein was detected in the lysate of T lymphocytes. This glycoprotein (GP65) gave several spots in the pI range 4.1-4.6 on 2-dimensional gel electrophoresis. Sialidase treatment of GP65 resulted in a single spot on the 2-dimensional gel, suggesting that GP65 is heterogeneous in the degree of sialylation. GP65 was shown to be exposed on the cell surface, since it was radiolabeled with 125I by the lactoperoxidase-catalyzed method. We next isolated GP65 from human peripheral blood lymphocytes by a combination of chromatography on a cation-exchange column and a WGA-agarose column and preparative SDS gel electrophoresis. It is suggested that GP65 is a novel surface glycoprotein on human NK cells.

Chromatography, Affinity↗
PubMed1992

Proliferating cell nuclear antigen in malignant and pre-malignant lesions of epithelial origin in the oral cavity and the skin: an immunohistochemical study.

Proliferating cell nuclear antigen (PCNA) is a nuclear protein synthesized in the late G1 and S phase of the cell cycle and immunohistochemical detection of the protein represents a useful marker for the proliferating fraction of cells in tissue specimens. A series of malignant and pre-malignant lesions of the oral cavity and skin were evaluated by the streptavidin biotin immunoperoxidase method for detection of this protein. Monoclonal anti-PCNA antibody (PC 10) labelled proliferating cells in all cases with varying intensity of nuclear staining. In squamous cell carcinoma (n = 48), PCNA positivity correlated with the differentiation and atypia of the tumour cells; however, in poorly differentiated tumours, the relationship between PCNA expression and proliferation was lost. Basal cell carcinoma showed an increased growth fraction in tiny epithelial nests (mean 43.8, SD 6.0, n = 20) than in neoplastic basal cells (mean 30.1, SD 6.9, n = 8). The growth fractions were significantly higher in the pre-malignant lesions (leukoplakia, mean 22.3, SD 7.7, n = 14; Bowen's disease, mean 45.2, SD 11.7, n = 12; senile keratosis, mean 41.2, SD 7.0, n = 12) than in the normal mucosa (mean 9.8, SD 4.9, n = 10), suggesting that cellular growth fractions correlate with the degree of dysplasia in pre-malignant lesions.

Antibodies, Monoclonal↗
PubMed1992

Hepatitis type C virus infection in patients with type B chronic liver disease.

Anti-c100-3 (Ortho) was determined in the sera of 152 patients with HBs antigen-positive chronic liver diseases to assess coinfection of hepatitis B virus (HBV) and hepatitis C virus (HCV). Eleven patients (7.2%) were positive for anti-c100-3. Anti-CP-9 (Okamoto) and HCV-RNA (RT-PCR) were also examined in these 11 patients. Anti-CP-9 was detected in 7 patients and HCV-RNA was detected in all 11 patients. Four of the 11 anti-c100-3-positive patients were positive for HBe antigen (HBeAg) and others were negative. In 8 of the 11 patients, HCV was suspected to be superinfected by blood transfusion. In HBeAg-positive patients, serum glutamic pyruvic transaminase (SGPT) was elevated in relation to active replication of HBV shown by DNA-polymerase activity. The histological findings showed chronic active hepatitis, with or without cirrhosis. On the other hand, in HBeAg-negative patients, SGPT fluctuated without evidence of active replication of HBV. Active inflammation in the liver was observed in 3 of 5 HBeAg-negative patients by liver biopsy. These findings suggest that HBV might play an important role in chronic active inflammation in HBeAg-positive patients coinfected with HCV, and that HCV might be responsible for continuous inflammation in HBeAg-negative patients coinfected with HCV.

Adult↗
PubMed1992

Proliferation of collagen fibrils and Ito cells in the liver after Japanese sake administration in undernourished rats as demonstrated by scanning electron microscopy.

Intralobular fibrosis of the liver was induced in undernourished rats by administering Japanese sake for 12 days. Control rats administered the equivalent calories with glucose solutions did not show any fibrosis. In the sake group, Ito cells were increased and often clustered under the scanning electron microscope (SEM). Many collagen fibrils 0.1 microns in diameter twisted around Ito cells which had numerous microvillous projections. On the contrary, fibrils were not increased and Ito cells had rather smooth surfaces in the control group. The number of Ito cells counted under the SEM at 500 magnifications was increased in the sake group (mean +/- standard deviation; 70 +/- 23/mm2) as compared to the control group (44 +/- 9; P less than 0.01). The fact that Ito cells had proliferated and were tangled with collagen fibrils in the sake group was demonstrated three-dimensionally by SEM.

Animals↗
PubMed1992

Soluble HLA class I antigens in sera of patients with chronic hepatitis.

Soluble HLA Class I antigens in sera (serum-HLA Class I, s-HLA Class I) of patients with chronic hepatitis (CH) were measured with an enzyme-linked double determinant immunoassay (E-DDIA). The mean titers of s-HLA Class I antigens of patients with CPH (mean +/- standard deviation, 2.22 +/- 1.60), CAH2A (2.24 +/- 1.65) or CAH2B (2.73 +/- 1.46) were significantly higher than that of normal subjects (0.36 +/- 0.27) (P less than 0.01). The titer of s-HLA Class I correlated significantly with the level of serum glutamic pyruvic transaminase (s-GPT) (r = 0.73), and weakly with serum level of beta 2-microglobulin (r = 0.43). In patients with chronic hepatitis type B (CH-B) treated with human lymphoblastoid interferon alpha (IFN-alpha), the titer of s-HLA Class I antigens increased. The increased level of s-HLA Class I antigens in the clinical course of chronic hepatitis may be caused by their release from necrotizing hepatocytes which have acquired the expression of HLA Class I antigens on the cell-surface membrane during viral infection.

Adult↗
PubMed1992

Obliteration of portal systemic shunts as therapy for hepatic encephalopathy in patients with non-cirrhotic portal hypertension.

The effects of obliteration of portal systemic shunts (PSS) in 5 patients with non-cirrhotic hepatic encephalopathy is reported. All patients had a history of disturbance of consciousness for several years, and examinations revealed large PSS, most of which connecting the left gastric vein to the left renal vein. After the obliteration of PSS, portal vein pressure elevated, the shunt ratio of the portal blood flow decreased, the indocyanine green disappearance rate increased, and serum albumin increased. Blood ammonia (NH3) decreased significantly accompanied by disappearance of hepatic encephalopathy. This treatment may open a way to improve the quality of life in patients with large PSS without severe hepatic injury.

Aged↗
PubMed1992

Histological pancreatitis in end-stage renal disease.

To clarify a possible cause of hyperamylasemia in end-stage renal disease (ESRD), histological studies were performed on the pancreatic glands of twenty-seven autopsied patients with ESRD who had received long-term hemodialysis. The findings were compared with those in a similar number of age-matched control subjects. Histological evidence of pancreatitis was found in 51.9% of the ESRD patients as compared with 14.8% in the controls (p < 0.005). The pancreatitis was chronic in nature in 85.7% of the ESRD patients showing changes of pancreatitis. Secretin administration to an additional group of twelve patients with ESRD induced an elevation in the activities of both total and P-type serum amylase in only one patient. These findings suggest that although histological pancreatic alterations are common in patients with ESRD, they are probably not responsible for the P-type hyperamylasemia frequently found in such patients.

Adult↗
PubMed1992

Chinese hamster ovary cells produce an enzyme that nicks heat-labile enterotoxin from enterotoxigenic Escherichia coli.

Chinese hamster ovary (CHO) cells were examined for production of an enzyme that nicked the polypeptide chain of the heat-labile enterotoxin from enterotoxigenic Escherichia coli between the A1 and A2 fragments of its A subunit. Serum-free culture medium prepared each day after CHO cell inoculation was concentrated 100 times and its proteolytic activity for formation of the A1 fragment was examined by Western blotting with anti-LT A antibody. The A subunit was detected in culture medium on day 6 after cell inoculation, although not in media on day 1 or 3, indicating that CHO cells produced a nicking enzyme. This nicking enzyme had an optimal pH of about 7.5 and an apparent Mr. of 120,000, as seen by Superose 12 TM gel filtration with an FPLC system. The activity of this enzyme was strongly inhibited by diisopropyl fluorophosphate and phenylmethylsulfonyl fluoride, but not by p-chloromercuribenzoic acid, EDTA or ethyleneglycol bis (beta-aminoethylether)-N,N-N',N'-tetraacetic acid, suggesting that this enzyme was a serine protease. The activity was not stimulated by plasminogen or fibrin. These findings suggest that the nicking enzyme was different from proteases such as elastase, collagenase and plasminogen activator, which are probably also secreted by fibroblast-like CHO cells.

Animals↗
PubMed1992

Immunohistochemical localization of Na,K-ATPase in the in situ lens, cultured human lens epithelium and lentoid.

The localization of Na,K-ATPase in the lens is quite controversial. We explored this problem through immunoelectron microscopic examination of rat and human lens. Unlike previously reported results, we have found that Na,K-ATPase is localized in the basal plasma membrane, but not in the lateral or apical plasma membrane of both rat and human lens epithelium. The lens fiber lacked immunoreaction. Localization of Na,K-ATPase was also investigated in the cultured human lens epithelium and in lentoid. Immunoreaction was detected in the apical (facing the media) plasma membrane of the lens epithelium cultured on the lens capsule, whereas the reaction was observable in both apical and basal plasma membrane of the lens epithelium cultured on the biopore membrane filters. Immunoreaction in lentoid was observed in the surface plasma membrane. These data indicate that the polarized distribution seen in the in situ lens epithelium changes when these cells are cultured, and that Na,K-ATPase in the cultured lens cells including lentoid is located in the plasma membrane which is in contact with the growth media. This change in polarity of Na,K-ATPase distribution in cultured epithelial cells may be dictated by the need to maintain ion homeostasis by extrusion of sodium ions across the cell membrane facing the media.

Animals↗