Biomedical subjects

T Tsuji

Publications and source records attributed to T Tsuji.

At least 739 records · Page 41Linked to original sources

PubMed1992

Characterization of a monoclonal antibody that specifically binds to choline phospholipids and its use in immunocytochemistry.

A monoclonal IgM (MC22-33F), raised in response to mouse embryonic dental papilla cells, was selected for further analysis on the basis of the unusual resistance of its epitope to detergent extractions and protease treatments of cell cultures. Binding of MC22-33F to cultured cells was abolished after either pre-treatment of the cells with phospholypase C or pre-incubation of the hybridoma culture supernatant with multilamellar phosphatidylcholine-containing vesicles. MC22-33F reacted with phosphatidylcholine, with the phosphatidylcholine analogue dimethylphosphatidylethanolamine, and with sphingomyelin immobilized on polystyrene surfaces or in thin-layer chromatograms. Crossreaction with other phospholipids was not observed. The surface of cultured epithelial cells was labeled by MC22-33F at sites of bleb formation. Combining immunostaining by MC22-33F and histochemical staining of cultured cells revealed codistribution of phospholipid-containing inclusions with either lysosomes or neutral fat droplets, and inhibition of lipid degradation by kanamycin resulted in a parallel accumulation of these inclusions and of neutral fats in the cytoplasm. Immunolabeling by MC22-33F of frozen mouse tissues was maximal in fat-storing and steroid-producing cells. Extracellular phospholipids present in calcifying cartilage septa strongly reacted with MC22-33F. This monoclonal antibody offers an interesting alternative to histochemical lipid stains for investigating fatty metamorphosis and extracellular lipid deposition under physiological and pathological conditions.

Animals↗

PubMed1992

Amino acids and peptides. XVI. Synthesis of N-terminal tetrapeptide analogs of fibrin alpha-chain and their inhibitory effects on fibrinogen/thrombin clotting.

N-Terminal tetrapeptide analogs of fibrin alpha-chain were synthesized by the solution method using a new active ester, the ester of the oxime of p-nitroacetophenone, and by the solid-phase method. Their inhibitory effects on fibrinogen/thrombin clotting were examined. Of the synthetic peptides, amide analogs of Gly-Pro-Arg-Pro exhibited a more potent inhibitory effect.

Amino Acid Sequence↗

PubMed1992

Effects of reperfusion on left ventricular ejection fraction and volume after acute myocardial infarction.

The effects of reperfusion on left ventricular (LV) function and volume were studied in patients with evolving acute myocardial infarction (AMI). We analyzed the LV ejection fraction and volume in patients who had been admitted within 24 h of the onset of their first AMI with culprit lesion of #6, #7 and #1 (American Heart Association classification). Sixty-five patients (Re group) received successful reperfusion therapy within 6 h after the AMI. The other 60 patients (Oc group), who were admitted from 6 to 24 h after the AMI, received conservative therapy. Patients with re-obstruction of the culprit lesion after reperfusion therapy were excluded from the Re group. Patients with spontaneous recanalization following conservative therapy were excluded from the Oc group. The LV ejection fraction (LVEF), LV end-systolic volume index (LVESVI), and LV end-diastolic volume index (LVEDVI) were measured using a modified Dodge's formula by left ventriculography performed 4 weeks after the AMI. LVEF in the Re group was significantly greater than in the Oc group (57 +/- 12 vs 49 +/- 11%) (mean +/- SD, p less than 0.01). LVESVI in the Re group was significantly smaller than in the Oc group (30 +/- 13 vs 38 +/- 16 ml/m2, p less than 0.01). Although LVEDVI was not significantly different between the 2 groups, in patients with a responsible coronary lesion of segment #6, LVEDVI in the Re group was significantly smaller than in the Oc group (67 +/- 14 vs 77 +/- 18 ml/m2, p less than 0.05). Although LVEF and LV volume correlated in both groups, the correlation was weak (r = 0.40-0.42), suggesting that LV volume was not dependent solely on LV functional recovery. The incidence of ventricular aneurysm in the Re group was significantly lower than in the Oc group (15.4 vs 45.0%, p less than 0.01). Multivariate analysis selected reperfusion of the responsible coronary artery as one of the factors significantly associated with a reduction of LVEDVI, LVESVI, an improvement of LVEF, and a decrease in the rate of aneurysm formation. In summary, our results indicated that reperfusion improved EF, reduced LV volume, and decreased the rate of aneurysm formation as compared to non-reperfusion, which suggests that reperfusion therapy is beneficial for both functional recovery and ventricular remodeling.

Adult↗

PubMed1992

Emergency coronary angioplasty for acute myocardial infarction--factors affecting acute restenosis in catheterization laboratory and reocclusion during hospitalization.

A total of 107 consecutive patients with acute myocardial infarction underwent emergency coronary angioplasty (PTCA). Restoration of blood flow with TIMI grade III was established by emergency PTCA in 101 patients (94.4%). "Acute restenosis" was defined as a lesion that, when dilated to less than 50%, narrowed again to more than 75% luminar reduction 5 min after the balloon inflation. Acute restenosis occurred in 39 patients (39%). Multivariate analysis selected 3 factors associated significantly with an increased rate of acute restenosis: (1) dissection, (2) small balloon/artery diameter ratio and (3) low systolic blood pressure during PTCA. Reocclusion, which was defined as a total reobstruction of the lesion during hospitalization following emergency PTCA, was examined by predischarge coronary angiography. Acute restenosis correlated significantly with an increase in reocclusion rate. The incidence of documented reocclusion was 12%. Residual stenosis, multivessel disease and irregular dilation correlated significantly with an increased rate of reocclusion. The in-hospital and postdischarge mortalities were 5.6% and 2.1%, respectively. In summary, emergency PTCA produced a high angiographic success rate. Use of adequate balloon size and sufficient dilation correlated significantly with angiographic outcome in emergency PTCA. Patients with acute restenosis, high residual stenosis, irregular dilation, and multivessel disease would have a relatively high risk of reocclusion.

Adult↗

PubMed1992

Anti-C100-3 antibody status, viral genomic sequences, and clinical features in chronic hepatitic patients with hepatitis C virus RNA in sera.

Since detection of hepatitis C virus RNA by the polymerase chain reaction (PCR) showed that there existed anti-C100-3 (anti-HCV) antibody negative patients infected with HCV, we attempted to find out whether there were any clinical or viral genomic differences between the anti-HCV antibody positive and negative groups. One hundred and fifty-nine patients with chronic liver diseases with hepatitis C virus RNA in their sera were selected. Anti-HCV antibody was tested for anti-C100-3 antibody by an enzyme linked immunosorbent assay. The incidence of anti-HCV antibody was 129/159. The concentration of serum gamma-globulin, the titier of ZTT, and the positive rate of the PCR with the primers of the NS3/4 region (NS3/4PCR) were significantly higher in the anti-HCV antibody positive group than in the negative group. However, the other data such as alanine aminotransferase activity or past history were not significantly different. Nucleotide sequence of the cDNA fragments of NS3/4 region amplified by the PCR did not differ significantly between isolates from anti-HCV antibody positive and negative sera. The sequences observed in the present study did not differ significantly from those reported previously. Although there remains the possibility that the variation of viral genomic sequences may cause the absence of anti-HCV antibody, these results suggested that the individual clinical backgrounds or immunoreactivity of the patients might influence the antibody development.

Adult↗

PubMed1992

Rat liver nodules induced by 2-acetylaminofluorene lose an ability to take up indocyanine green in the process of hepatocarcinogenesis.

Indocyanine green (ICG) was injected into rat liver nodules induced by 2-acetylaminofluorene (2-AAF) via portal vein. The relationship between ICG staining and cell atypism of liver nodules was examined by means of histology and DNA flow cytometry. After 2-AAF administration, many small nodules appeared on the liver surface. All hyperplastic nodules were ICG stained until 10 weeks after the administration, but some nodules were not stained after 14 weeks. ICG-stained nodules histologically consisted of benign tissues and borderline lesions, and many of them showed "diploidy" in DNA cytometry. ICG-unstained nodules consisted of hepatocellular carcinoma (HCCs) and borderline lesions, and many of them showed "aneuploidy". In this way, it has been suggested that HCC could derive from hyperplastic nodules and that they might lose an ability to take up ICG in the process of hepatocarcinogenesis. Immunohistochemical staining for glutathione-S-transferase alpha (GST-alpha), a carrier protein of ICG in hepatocytes, was well correlated with ICG staining in the nodules, suggesting that the loss of ICG uptake in HCC was partly due to the decrease of GST-alpha. Moreover, the appearance of ICG unstained and aneuploid nodules was significantly inhibited in rats which were fed on diet containing Syosaiko-to after the administration of 2-AAF. Chemopreventive effect of Syo-saiko-to on hepatocarcinogenesis was identified.

2-Acetylaminofluorene↗

PubMed1992

Detection by western blotting of an antibody to the hepatitis C virus E1 envelope protein in sera of patients with chronic liver disease.

We detected an antibody to HCV envelope protein (E1) in sera of patients with HCV-related chronic liver diseases (20 patients with chronic hepatitis and 5 patients with liver cirrhosis) by Western blotting using the fusion protein of E1 envelope protein and beta-galactosidase as an antigen. The antibody to HCV E1 (anti-HCV E1) was detected in 8 (42%) of 19 patients positive for HCV-RNA (16 were positive and 3 were negative for antibody to C100-3) and in 1 (17%) of 6 patients negative for HCV-RNA but positive for antibody to C100-3. HCV-RNA was detected in 8 (89%) of 9 anti-HCV E1 positive sera. The value of alanine aminotransferase was significantly higher in patients positive for anti-HCV E1 than in patients negative for the antibody. Although an antibody to the envelope protein of HCV is suspected to be one of the candidates of virus-neutralizing antibodies, our results suggest this hypothesis appears to be unlikely.

Adolescent↗

PubMed1992

Hepatitis C virus antibody titration in patients with chronic hepatitis C, before and after interferon treatment.

We measured hepatitis C virus antibody titers in 13 patients with chronic hepatitis C to determine whether titration of hepatitis C virus antibody was useful or not, to predict and evaluate the efficacy of interferon (IFN) treatment. During administration of IFN, hepatitis C virus titers declined in all patients. Antibody titers performed before treatment as well as just at the end of treatment did not correlate with change of the alanine aminotransferase levels during administration of IFN. Antibody titers declined continuously after treatment in 5 patients with normal alanine amino-transferase levels for over 6 months after discontinuation of IFN. Antibody titers rose again in 6 patients whose alanine aminotransferase levels fluctuated after treatment. An exceptional pattern of change occurred in 2 patients whose antibody titers declined continuously although their alanine aminotransferase levels fluctuated after treatment. Repeated titration of hepatitis C virus antibody appears to be useful for evaluating the long-term efficacy of IFN treatment.

Adult↗

PubMed1992

NG-nitro-L-arginine attenuates flow debt repayment in the reactive hyperemic response of the open-chest dog coronary artery: contribution of endothelium-derived relaxing factor.

To test the hypothesis that the endothelium-derived relaxing factor (EDRF) contributes to coronary vasodilation induced by myocardial ischemia, we examined the effect of NG-nitro-L-arginine (a potent and selective inhibitor of EDRF release) on the coronary reactive hyperemic response in the open-chest dogs. Intracoronary infusion of NG-nitro-L-arginine at a coronary plasma concentration of 5 x 10(-5) M had no effect on hemodynamics and myocardial oxygen metabolism, but attenuated repayment of the flow debt by an average of 20.4% and 20.0% following coronary occlusion for 10 sec and 20 sec, respectively. Concomitant infusion of NG-nitro-L-arginine at the same concentration and 8-phenyltheophylline (a potent adenosine receptor blocker) at a coronary plasma concentration of 10(-5) M further attenuated flow debt repayment following 10 sec and 20 sec of coronary occlusion by 47.7 and 59.4%, respectively. These results indicate that EDRF plays a significant role in the coronary reactive hyperemic response and may cause vasodilation independently of adenosine-mediated vasodilation following coronary occlusion.

Adenosine↗

PubMed1992

The role of Kupffer cells in complement activation in D-Galactosamine/lipopolysaccharide-induced hepatic injury of rats.

To investigate the role of Kupffer cells in complement activation, we used a rat model of acute hepatic injury induced by D-Galactosamine (GalN) and lipopolysaccharide (LPS). In in vivo study, minimal histological changes were observed after i.p. GalN (200 mg/kg) single administration. Complement hemolytic activity (CH 50) decreased to 70% of its initial value 2-3 h after i.p. LPS (1.5 mg/kg) single administration. Massive hepatic necrosis was induced by simultaneous administration of GalN and LPS. After 2-3 h, CH 50 decreased to 70% of its initial value, and deposition of C3 fluorescence (C3) was observed in Kupffer cells. After 4 h, GPT was greatly increased (1286 +/- 240 IU/l), CH 50 was further reduced, and C3 was observed on hepatocyte membranes and in the cytosol. In in vitro study, we used hepatocyte cultures and co-cultures of hepatocytes and Kupffer cells to investigate the participation of GalN, LPS, complement, and Kupffer cells in hepatic cell necrosis. We found no increase of LDH (% leakage) when LPS and complement were added to the medium (22.7 +/- 5.7%). A moderate increase was observed with the addition of GalN (33.2 +/- 2.6%). A remarkable increase was observed only with the addition of GalN, LPS, and complement to the co-culture (50.0 +/- 8.8%). These results suggest that Kupffer cells activated by LPS are very important in promoting acute hepatic injury by complement.

Alanine Transaminase↗

PubMed1992

Combination of epidermal growth factor and insulin is required for multicellular spheroid formation of rat hepatocytes in primary culture.

We showed that the combination of epidermal growth factor (EGF) and insulin is an essential supplement to Williams' #E medium for the formation of floating multicellular spheroids in primary culture of rat hepatocytes. Isolated hepatocytes assembled to form floating multicellular spheroids within 96 h through transient assembly of monolayer islands within the initial 24 h in dishes coated with liver-derived proteoglycans. However, the assembly of multicellular spheroids was severely suppressed in the absence of either EGF or insulin. The reduction of spheroid assembly was correlated with decreased attachment and subsequent decreased formation of monolayer islands within 24 h. The minimum amounts of EGF and insulin required for the formation of floating spheroids were 1 ng/ml and 0.4 microgram/ml, respectively. These results suggest that the enhancement of hepatocyte attachment provided by the combination of EGF and insulin during the early phase of culture is required for the formation of floating spheroids.

Animals↗

PubMed1992

Localization of hepatitis C virus RNA in human liver biopsies by in situ hybridization using thymine-thymine dimerized oligo DNA probes: improved method.

To establish the most proper method of in situ hybridization in detection of HCV-RNA in the liver, various detailed procedures were examined using frozen as well as paraffin-embedded sections of tissue derived from patients. In frozen sections of the liver from hepatitis C patients obtained at autopsy or surgery, HCV-RNA was detectable by in situ hybridization using thymine-thymine dimerized oligonucleotide DNA probes when the sections were treated with ethanol-acetic acid at first, then 0.2 N hydrochloric acid, proteinase K (0.02 u/ml) and DNase. When the paraffin-embedded liver sections were used, more intense proteinase K treatment (0.2-2 u/ml) was required to expose viral RNA and even after that, the positive HCV-RNA signals were less than those in frozen sections, because the cytoplasmic RNA in the routine paraffin-embedded sections was preserved unevenly and less than in frozen sections. These findings indicate that in situ hybridization of HCV-RNA is useful for diagnosing HCV infection and should be a potent tool for monitoring the state of virus activities during therapy. However, the liver biopsy method should be modified so that RNA is retained properly to utilize biopsies more effectively for the routine diagnosis of HCV infection.

Base Sequence↗

PubMed1992

Suprachiasmal carotid-ophthalmic artery aneurysm--report of two cases.

Two rare suprachiasmal carotid-ophthalmic artery aneurysms, one large and one giant, were discovered incidentally. The patients had no visual disturbances. Angiography showed superomedial projection of the sac. The aneurysms were clipped via an ipsilateral pterional approach. A suprachiasmal carotid-ophthalmic artery aneurysm is indicated when preoperative angiography reveals a superomedial carotid-ophthalmic artery aneurysm without visual disturbances. Direct surgery to clipp a suprachiasmal aneurysm should be carried out to prevent rupture of these frequently large aneurysms.

Aged↗

PubMed1992