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T Tsuji

Publications and source records attributed to T Tsuji.

At least 703 records · Page 39Linked to original sources
PubMed1993

Colorectal cancer metastasis determined by carbohydrate-mediated cell adhesion: role of sialyl-LeX antigens.

Human colorectal carcinomas with increased metastatic potential and with poor prognosis are characterized by the high content of sialyl-LeX carbohydrate antigens. The levels of these carbohydrate antigens apparently increase during colorectal carcinoma progression from non-metastatic to metastatic tumors. The levels of tumor-associated sialyl-LeX antigens are inversely correlated to the post surgical survival of colon carcinoma patients as revealed by retrospective studies. Cell lines selected for high levels of cell surface sialyl-LeX antigens metastasize to livers when they are injected intrasplenically into nude mice. The highly expressing cells also strongly adhere to activated endothelial cells apparently through E-selectin. We conclude that sialyl-LeX carbohydrate antigen is a unique molecular phenotype that determines colorectal cancer metastasis.

Cell Adhesion↗
PubMed1993

Inhibition of Abelson oncogene function by erbstatin analogues.

The authors examined the effect of a tyrosine kinase inhibitor, erbstatin, and its analogues on abl oncogene functions. Erbstatin and its stable analogue methyl 2,5-dihydroxycinnamate (2,5-MeC) inhibited the growth of v-ablts-NIH3T3 cells at the permissive temperature (33 degrees C) at lower concentrations than at the non-permissive temperature (39 degrees C). 2,5-MeC inhibited the morphological transformation and the activation of v-abl tyrosine kinase by the temperature shift (39 degrees C to 33 degrees C) more effectively than erbstatin. Previously the authors reported that erbstatin induced erythroid differentiation of K562 human chronic myelogenous leukaemia cells, so they examined the effect of erbstatin analogues on the erythroid differentiation. Among eight erbstatin analogues studied, ethyl 2,5-dihydroxycinnamate induced erythroid differentiation of K562 cells most effectively. Ethyl 2,5-dihydroxycinnamate also inhibited bcr-abl tyrosine kinase. These results indicate that the stable analogues of erbstatin suppress oncogene functions of Abl by inhibiting its tyrosine kinase.

Abelson murine leukemia virus↗
PubMed1993

[Prefeeding of aldose reductase inhibitor inhibits galactose cataract].

To examine the effect of prefeeding the aldose reductase inhibitor (ARI) on the cataract induced by the subsequent feeding of galactose diet, rats were first fed rat chow with or without ARI for 2 weeks. The animals were then transferred to a 25% galactose diet for different periods of time. Lenses were enucleated and examined by light microscopy. The amount of galactitol in the lenses was examined biochemically. The cataract was less severe and there was less galactitol in the lenses in the rats first fed with ARI than in those without ARI. These results indicate that the feeding the ARI prior to galactose feeding partly inhibits galactose cataract.

Aldehyde Reductase↗
PubMed1993

Proliferative changes of lens epithelial cells in rat and mouse galactose cataracts--examination using whole-mount preparations.

The proliferative activity of the lens epithelium in the early stages of cataract crisis was investigated in rats and mice using the 3H-thymidine autoradiographic method with the whole-mount preparations of total lens epithelial cells. Three-week-old Sprague-Dawley (SD) rats were given a diet which included galactose in three different concentrations (15%, 25%, 50%) to produce sugar cataracts of three different degrees. Seven-week-old ICR mice were given a 50% galactose-diet. In the lenses of control rats and mice, 3H-thymidine labeled cells were observed mainly in the germinative zone at the lens equator; a few labeled cells were detected in the anterior subcapsular central zone. In the lenses of the SD rats on the 4th day of the diet, labeled cells increased remarkably in the central zone. However, labeled cells decreased as the cataract progressed. The peak in the number of labeled cells was observed on the 4th day of the diet regardless of the galactose concentrations, and was not proportional to the degree of the cataracts. In the galactose-fed ICR mice, the blood galactose level was high, but there was no increase in the number of labeled cells or the development of galactose cataract. The marked increase of labeled cells in the central zone in the SD rat lenses had probably occurred because of the accumulation of galactitol.

Animals↗
PubMed1993

Natural course of chronic hepatitis C.

We studied 333 chronic hepatitis C patients to evaluate the natural course of this disease. Among 57 patients undergoing serial biopsies, 20 had chronic persistent hepatitis (CPH) at the first biopsy, and 10 of them progressed to chronic active hepatitis (CAH) or liver cirrhosis (LC) after 11 yr. Sixteen patients had CAH 2A, and this progressed to CAH 2B or LC in 10 cases over 9 yr. Among the 21 patients with CAH 2B, progression to LC was noted in 15 after 7 yr. Among the 100 patients observed for over 5 yr, the normalization of liver function for at least 3 yr was seen in only four patients. In two of these four patients, serum HCV-RNA was tested serially. Despite the sustained normalization of alanine aminotransferase levels, HCV-RNA continued to be detectable in one patient. We conclude that many patients with chronic hepatitis C eventually show progression of their disease after a long and symptomless course.

Adolescent↗
PubMed1993

Synthesis of lens capsule in long-term culture of human lens epithelial cells.

PURPOSE: This study examined the extent to which human lens epithelial (HLE) cells in tissue culture retain the potential for differentiation, expression of lens-specific marker proteins, and the synthesis of lens capsule, the major characteristics of lens epithelium in vivo. METHODS: Primary cultures of HLE cells were maintained for up to 450 days. Transmission and immunoelectron microscopy were used to study the thickness of the synthesized capsule and the formation of type IV collagen and laminin, two major protein components of the basement membrane of lens capsule in vivo. RESULTS: In a long-term HLE culture system, without subcloning, lens fiber differentiation and capsular synthesis were maintained over a period of 450 days. In these cultures, the cell sheet showed three distinct zones: (1) a central zone with tight monolayer; (2) a mild peripheral zone with irregularly aggregated multilayer; and (3) a peripheral zone with loose monolayer. The basement membrane-like material was synthesized in the central zone and lentoids, which serve as a model for fiber differentiation, developed primarily in the mid peripheral zone. No capsular material or lentoids were observed in the peripheral zone. The capsule-like material was 2 to 2.5 microns thick and showed the presence of type IV collagen and laminin, as detected by antibody reaction. CONCLUSION: This study demonstrates for the first time that HLE cells in long-term cultures synthesize a continuous sheet of capsule-like material. The findings also suggest that reformation of a tight cell-to-cell relationship or generation of high cell density similar to that found in vivo may be an important factor for the synthesis of lens capsule.

Basement Membrane↗
PubMed1993

Successful repair and postoperative management of tetralogy of Fallot in a patient with maple syrup urine disease.

A case of tetralogy of Fallot with maple syrup urine disease (MSUD) treated surgically is reported. This 2-year-old female patient developed neurologic deterioration after intracardiac repair. Postoperative management, which included peritoneal dialysis, intravenous hyperalimentation, and early intestinal alimentation with branched-chain amino acid-free milk was successful. At the present time, two years after the operation, she is doing quite well with a special diet for MSUD. This is the first report on a patient with MSUD who underwent open heart surgery using a cardiopulmonary bypass, stressing the importance of postoperative management.

Cardiopulmonary Bypass↗
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↗