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Biomedical subjects

T Tsuji

Publications and source records attributed to T Tsuji.

At least 595 records · Page 33Linked to original sources
PubMed1994

Induction of superoxide anion production from monocytes an neutrophils by activated platelets through the P-selectin-sialyl Lewis X interaction.

Activated platelets expressing P-selectin on their surface are known to adhere to monocytes and neutrophils. We examined the possibility that the leukocytes were activated by their adhesion to activated platelets and demonstrated that P-selectin-dependent platelet adhesion to neutrophils and monocytes induced production of extracellular superoxide anion (O2-) by these leukocytes. Leukocyte membrane glycoproteins containing Ser/Thr-linked carbohydrate chains were responsible for the signal reception leading to the leukocyte activation. Cytokines were shown to influence these processes. For example, treatments of neutrophils with interleukin-8 (IL-8) or granulocyte colony-stimulating factor (G-CSF) potentiated the P-selectin-induced O2- production. Furthermore, interleukin-1 (IL-1) and interferon-gamma (IFN-gamma) induced surface expression of P-selectin on platelets in the presence of a low concentration of thrombin and consequently enhanced their adhesion capacity to leukocytes. These results indicated that the adhesion of activated platelets to the leukocytes through the interaction between P-selectin and its carbohydrate ligand, sialyl Lewis X (LeX), was a crucial step for the activation of leukocyte function and supported the notion that activated platelets were actively involved in the inflammatory processes.

Blood Platelets↗
PubMed1994

Intercellular adhesion induced by anti-alpha 3 integrin (VLA-3) antibodies.

We generated four monoclonal antibodies (mAbs) specific for human alpha 3 integrin (VLA-3 alpha subunit). All of them were found to induce homotypic cell aggregation of HT1080 fibrosarcoma and SN12C renal carcinoma cells, both of which express high levels of alpha 3 integrin. The antibodies also induced the cell aggregation of K562 erythroleukemic cells transfected with alpha 3 integrin cDNA, but not the parental K562 cells. The aggregation was observed in a temperature-dependent manner and was not inhibited by the addition of EDTA. Immunofluorescence microscopic observation showed that alpha 3 integrin on HT1080 cells was translocated into the contact regions after the mAb treatment. The intercellular adhesion between cells expressing alpha 3 integrin and cells without alpha 3 integrin was also induced by the anti-alpha 3 antibody treatment.

Antibodies, Monoclonal↗
PubMed1994

Construction of plasmids useful for production of the B subunit of cholera toxin from Vibrio cholerae or a heat-labile enterotoxin from enterotoxigenic Escherichia coli.

A simple method to construct the plasmids producing the B subunit of porcine or human heatlabile enterotoxin or cholera toxin was developed, and the B subunits produced by the resulting plasmids were purified. The gene of LTp from pEWD 299 was ligated to pHSG 396 or pBluescript SK(+)-1 and the vector carrying one Xbal and EcoR1 site in the LTp-A gene was constructed. The Xbal-EcoR1 fragment of LTp-A gene was exchanged for the multicloning site of pHSG 396 containing Xbal, BamH1, Cla 1, Kpn1, Sac1 and EcoR1 sites. This plasmid (pTSU28) produced the LTp-B subunit. Moreover, the fragment of the LTp-B gene of pTSU 28 was exchanged by the EcoR1-HindIII fragment of LTh-B from E. coli H10407 strain (pTSU 35) or by the Cla 1-Hind III fragment of CT-B gene amplified by the PCR procedure with the chromosomal DNA of V. cholerae 86KT25 (pTSU 32). The DNA sequence of the CT-B subunit amplified by PCR procedure was compared and found identical to that cited in the literature [11]. After these plasmids were transformed into E. coli MV 1184 strain, the toxins produced by them were purified using a Bio-Gel A 5m affinity column for both LT-Bs and an immunobilized D-galactose affinity column for CT-B. Though both columns absorbed only the B subunit, the eluates contained a single protein corresponding to the B subunit, suggesting that each mutant produces only the B subunit.

Animals↗
PubMed1994

Effect of proton pump inhibitor, omeprazole, on expression of rat parietal cell specific carbohydrate antigen, type 2 chain N-acetyllactosamine.

The effect of a proton pump inhibitor, omeprazole, on the rat gastric mucosal expression of carbohydrate antigens was studied. Type 2 chain N-acetyllactosamine was detected specifically on the apicocanalicular cell membranes of parietal cells. Pretreatment of rats with omeprazole profoundly suppressed the antigen expression, which followed the inhibition of gastric acid secretion. When omeprazole was discontinued, the antigen was reexpressed, which preceded the restoration of acid secretion. The antigen-negative tissues became antigen-positive when they were desialylated. Gastric membrane vesicles from the normal and omeprazole-treated rats were antigen-positive and -negative, respectively. SDS-PAGE revealed that a glycoprotein with an apparent molecular weight of 64-78 kDa carried type 2 chain N-acetyllactosamine. In the omeprazole-treated rats, the same molecular weight glycoprotein was positively immunostained only after desialylation. We concluded that: (1) the expression of type 2 chain N-acetyllactosamine was closely correlated with gastric acid secretion, and (2) the inhibition of acid secretion was accompanied by the sialylation of the parietal cell membrane glycoprotein.

Amino Sugars↗
PubMed1994

Quantitative detection of hepatitis C virus genome in liver tissue and circulation by competitive reverse transcription-polymerase chain reaction.

We quantified hepatitis C virus RNA in 25 Japanese patients with chronic type C liver disease by competitive reverse transcription-polymerase chain reaction. The amount of the viral RNA in the serum (2 x 10(5)-2 x 10(8) copies/ml) correlated with that in the liver tissue (10(8)-10(11) copies/g) (N = 23, r = 0.727, P < 0.0001). One gram of the infected liver tissue contained 10(2)-10(4) (geometric mean, 10(3), N = 23) times as many copies of the viral RNA as did 1 ml of the serum. Liver tissues of chronic aggressive hepatitis contained significantly higher amounts of the viral RNA than those of chronic persistent hepatitis (P < 0.05). These observations suggested that this method is useful to evaluate viral amount, and the amount of the circulating hepatitis C virus RNA could be used as a marker of the intrahepatic viral amounts, which might contribute to disease activity.

Adult↗
PubMed1994

Elevated urokinase-type plasminogen activator plasma levels are associated with deterioration of liver function but not with hepatocellular carcinoma.

We measured urokinase-type plasminogen activator (u-PA) plasma levels in patients with various chronic liver diseases, including hepatocellular carcinoma (HCC), also measuring these levels in healthy volunteers. Plasma u-PA levels in the group of patients with decompensated liver cirrhosis (mean modified Pugh score of 14 points) were markedly elevated and significantly higher than those in the patients with decompensated liver cirrhosis with HCC (modified Pugh score of 10 points), those with compensated liver cirrhosis with HCC, and those with compensated liver cirrhosis. Patients in all these three latter groups had moderately and significantly elevated u-PA levels compared to levels in the chronic hepatitis group and the healthy volunteers, but the levels were not significantly different from each other. There was no relationship between u-PA plasma level and the type of HCC tumor invasion or number or size of tumors. Significant correlations were found between u-PA plasma levels and the results of seven different liver function tests in three groups without associated HCC; u-PA antigen and prothrombin time (%), hepaplastin test (%), serum cholinesterase, serum albumin, serum total cholesterol, and indocyanine green clearance correlated negatively, while u-PA antigen and serum total bilirubin correlated positively. These results suggest that plasma u-PA is associated with deterioration of liver function but not with HCC invasion.

Carcinoma, Hepatocellular↗
PubMed1994

Immunohistochemical study of the distribution of intercellular adhesion molecule-1 and lymphocyte function-associated antigen-1 in chronic type B hepatitis.

The expression of intercellular adhesion molecule-1 (ICAM-1) and lymphocyte function-associated antigen-1 (LFA-1) in the livers of 11 patients with chronic hepatitis B was studied immunohistochemically by light and electron microscopy to clarify the role of these adhesion molecules in tissue damage in chronic hepatitis B. On hepatocytes, ICAM-1 expression was confined to the bile canalicular surface when the liver inflammation was mild. In contrast, when the liver inflammation was severe, ICAM-1 was distributed on the entire surface of the hepatocyte, including the sinusoidal and lateral membranes; lymphocytes which were mostly positive for LFA-1, were often observed invading deeply among these hepatocytes. The degree of ICAM-1 expression on the hepatocytes was also related to the expression of HLA class 1 antigen. In liver showing diffuse expression of ICAM-1 on the hepatocytes, strong expression of HLA class 1 antigen was observed, and amounts of HBV in the liver were decreased. Diffuse expression of ICAM-1 and HLA class 1 antigen was mostly observed after acute exacerbation of liver inflammation. These results suggest that the ICAM-1/LFA-1 pathway is involved in the immunological mechanism responsible for liver cell damage in chronic hepatitis B.

Cell Adhesion Molecules↗
PubMed1994

Immunocytochemical localization of choline-phospholipids in postnatal mouse molars.

This localization was studied using anti-choline phospholipid monoclonal IgM antibody (MC22-33F). By immunofluorescence, the apical portions of enamel-secreting ameloblasts and dentine-secreting odontoblasts were positively stained with MC22-33F. By immunoelectron microscopy, lysosomes in preodontoblasts, odontoblasts, preameloblasts and ameloblasts as well as matrix vesicles in dentine were strongly stained with MC22-33F. On the other hand, plasma membrane of these cells did not stain with MC22-33F. The frequency of positively reacting lysosomes in ameloblasts and odontoblasts and of matrix vesicles increased with cell maturation and mineral deposition.

Ameloblasts↗
PubMed1994

Comparative studies of in vitro and in vivo function of three different shaped bioartificial pancreases made of agarose hydrogel.

Various kinds of bioartificial pancreas (BAP) have been developed in the past. There have been many disputes about the advantages and disadvantages of each BAP. However, little attention has been paid to the shape of the devices. In this study, three different shaped BAPs were made of the same material, agarose hydrogel. These are microbead-, rod- and disc-shaped BAPs, which are comparable to microcapsules, hollow fibre diffusion chambers and disc-shaped diffusion chambers, respectively, in shape. Their performances were studied by in vitro culture, mathematical simulations and in vivo implantation into diabetic animals. The islets in the BAPs could survive and release insulin for more than 100 d regardless of the BAP shape during in vitro culture. Numerical analyses showed that insulin release kinetics depended greatly on the thickness of the gel membrane but not on the shape of the agarose hydrogel. The microbead BAP normalized blood glucose levels of all five recipients for more than 100 d. Three of eight recipients of the rod BAP and only one of six recipients of the disc BAP demonstrated long normoglycaemia. These results suggest that the shape of the BAPs determines the in vivo functioning period of the BAPs and that the microbead is the most suitable shape for the BAP.

Animals↗
PubMed1994

Constitutive production of IL-6 in the anemic mice of W/Wv genotype.

IL-6 was found to be produced by bone marrow cell fraction enriched for hemopoietic stem cells in response to IL-3 stimulation. To confirm the production of IL-6 by hemopoietic stem cells, we studied the response of W/Wv mouse bone marrow cells to IL-3 stimulation in terms of IL-6 production. Genetically anemic mice of W/Wv genotype are known to be depleted of normal hemopoietic stem cells. Bone marrow cells of W/Wv mice produce IL-6 without IL-3 stimulation. But bone marrow cells of the litter mate (+/+) mice studied as controls do not produce IL-6 without stimulation. IL-3 induced the production of IL-6, GM-CSF and G-CSF from the bone marrow cells of +/+ mice. Gene expression of IL-6, GM-CSF, G-CSF and IL-3 in these mice was detected in total bone marrow cells after IL-3 stimulation. In contrast, bone marrow cells of C3H mice did not produce IL-3 even after IL-3 stimulation. Bone marrow cells of C3H mice reportedly produce a diffusible IL-3 inhibitor (NIL-3), but those of C57BL mice do not. Present findings indicate the strain-dependent differences in hemopoietic stimulating factor production. The constitutive IL-6 production in W/Wv mice might be due to a constant and strong demand for blood cell production of the anemic mice.

Anemia↗
PubMed1994

Effects of endothelium removal by saponin and of oxyhemoglobin on canine cerebrovascular responses.

The stainless steel cannula method was applied to isolated and perfused canine basilar arteries to examine the role of endothelium in the responses to intraluminal vasoactive substances. After intraluminal treatment with saponin to remove the endothelium, the monophasic constrictions to potassium chloride and prostaglandin F2 alpha were potentiated, while those to phenylephrine (alpha 1-adrenoceptor agonist) and 5-hydroxytryptamine were not changed. Xylazine (alpha 2-adrenoceptor agonist) and acetylcholine induced a constriction preceded by a small dilation in controls. The response to xylazine was not modified, while the constriction to acetylcholine was augmented after endothelium removal. Bradykinin, substance P and vasopressin caused a dilation in lower doses, and a dilation followed by a secondary constriction in higher doses in controls. The dilations to these peptides were reduced and the constrictions were enhanced after endothelial removal. Adenosine triphosphate produced a biphasic response, i.e., a dilation followed by a constriction, which was occasionally preceded by a small constriction in higher doses, and only the dilation in lower doses was attenuated. The monophasic dilation to adenosine was potentiated, while the papaverine-induced dilation was not influenced by endothelial removal. After extraluminal treatment with oxyhemoglobin, the dilations to calcium ionophore A23187 and thimerosal were attenuated, while the constriction to acetylcholine was enhanced. The dilations to substance P and vasopressin were depressed, and the constrictions were potentiated. The monophasic dilation to sodium nitroprusside was augmented, while that to papaverine was not changed. These results suggest that the endothelium may play important roles not only in producing endothelium-derived relaxing factors but also in modulating the calcium influx into the smooth muscle cells. The mechanisms of altered responsiveness might be implicated in cerebral vasospasm following subarachnoid hemorrhage.

Animals↗
PubMed1994

Studies on vocal fold injection and changes in pitch associated with alcohol intake.

The current study was carried out with particular emphasis on the association between phonetic function tests and alterations in the appearance of the hypopharyngeal and laryngeal mucosa, such as capillary dilatation, edema, and vocal fold injection after alcohol intake. The results demonstrated the occurrence of previously unrecognized pathophysiological changes associated with synchronous phonetic functions in the vocal pathway after alcohol intake. Serum ethanol and aldehyde concentration levels were evaluated hourly for 2.5 h after ingestion of alcohol. When an electronystagmogram showed the typical pattern of alcohol intake, the study was initiated. Occasionally, rhinography was performed on subjects complaining of a stuffy nose after alcohol intake.

Adult↗
PubMed1994

Effects of various protease inhibitors on the intestinal absorption and degradation of insulin in rats.

The effects of protease inhibitors on the intestinal absorption of insulin were investigated in situ in closed small and large intestinal loops in rats, and the stability of insulin was examined in homogenates of the small and large intestine. The intestinal absorption of insulin was evaluated by its hypoglycemic effect. When insulin alone was administered into small or large intestinal loops, no marked hypoglycemic response was observed in either region. Of the coadministered protease inhibitors, soybean trypsin inhibitor (1.5, 10 mg/ml) marginally promoted insulin absorption from the large intestine, whereas aprotinin (10 mg/ml) did to a moderate degree. However, a significant hypoglycemic effect was obtained following large intestinal administration of insulin with 20 mM of Na-glycocholate, camostat mesilate and bacitracin, when compared with the controls. In contrast, we found little hypoglycemic effect following small intestinal coadministration of insulin with these protease inhibitors. In the stability experiment, bacitracin, camostat mesilate and Na-glycocholate were effective in reducing insulin degradation in both small and large intestinal homogenates. It was found that the reduction in the proteolytic rate of insulin was related to the decrease in plasma glucose concentration by these protease inhibitors in the large intestine. These findings suggest that coadministration of protease inhibitors would be useful for improving the large intestinal absorption of insulin.

Animals↗
PubMed1994

Liver disease.

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Female↗
PubMed1994

Hepatic neoexpression and increased plasma levels of Lewis Y, a carbohydrate antigen, in chronic inflammatory liver diseases.

The clinicopathologic relevance of the hepatic expression of Lewis Y (Le(y)), a carbohydrate antigen, and its plasma levels was studied in benign and malignant liver diseases. Tissue and plasma antigens, respectively, were determined with an avidin-biotin-peroxidase complex method and a radioimmunoassay using monoclonal antibody AH6. Normal liver cells and bile ductules did not express Le(y). In the inflammatory tissues, the liver cells and proliferated bile ductules expressed Le(y). The strongest expression by the liver cells was observed in chronic active hepatitis with severe activity and that by the ductules in liver cirrhosis. Only 1 of 16 hepatocellular carcinomas expressed Le(y). The plasma levels of Le(y) increased significantly but nonspecifically in chronic persistent hepatitis, chronic active hepatitis, liver cirrhosis, and hepatocellular carcinomas. It was concluded that (1) Le(y) is an inflammation-associated but not a cancer-associated antigen; (2) the more the tissue damage advances, the more the antigen is expressed; and (3) hepatic and plasma Le(y) are, however, nonspecific markers of necroinflammatory liver diseases.

Adolescent↗