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S Fujimoto

Publications and source records attributed to S Fujimoto.

At least 379 records · Page 21Linked to original sources
PubMed1996

Tyrosine phosphorylation and translocation of phospholipase C-gamma 2 in polymorphonuclear leukocytes treated with pervanadate.

We examined in detail the tyrosine phosphorylation of proteins, especially inositol phospholipid-specific phospholipase C (PLC) gamma 2, during activation of respiratory burst of guinea pig polymorphonuclear leukocytes (PMNs) by pervanadate. The pervanadate, generated from a combination of H2O2 and orthovanadate, induced concomitantly tyrosine phosphorylation of 145, 120, 104, 76, 68, 60, 53, 42, 37, 28, and 25 kDa proteins and superoxide anion (O2-) production of PMNs. The pretreatment of PMNs with genistein caused an inhibition of tyrosine phosphorylation of these proteins, and also markedly depressed O2- production. Among the above proteins, a 145 kDa protein was found to be identical with the protein recognized by the anti-PLC gamma 2 antibody on Western blots. PLC gamma 2 was detected in the cytosol fraction but not in the membrane fraction of resting PMNs, whereas it was detected in both cytosol and membrane fractions of pervanadate treated PMNs. PLC activity of pervanadate treated PMNs was higher than that of resting cells. In addition, the enzyme activity of the cytosol fraction from the former cells was significantly lower than that from the latter cells, whereas the enzyme activity of membrane fraction from the former cells was significantly higher than that from the latter cells. These findings suggest that the tyrosine residue(s) of PLC gamma 2 is phosphorylated and the enzyme is translocated from the cytosol to membrane fractions in PMNs by pervanadate treatment.

Animals↗
PubMed1996

A tumor-specific Th2 clone initiating tumor rejection via primed CD8+ cytotoxic T-lymphocyte activation in mice.

We established a CD4+ T-cell clone specific for syngeneic methylcholanthrene-induced sarcoma, S1509a raised in an A/J mouse, involved in tumor regression. The phenotype of the T-cell clone was CD3+, TCR-beta+, CD4+, CD45RB+, LFA-1+, ICAM-1+, CD44+, and VLA-4+. The CD4+ T-cell clone specifically proliferated through antigen stimulation with attenuated S1509a in the presence of syngeneic accessory cells, and this antigen-induced proliferation was inhibited with anti-CD4 and anti-I-Ek monoclonal antibodies. The CD4+ T-cell clone designated YS1093 secreted interleukin (IL) 4, IL-5, and IL-6, but not IFN-gamma, tumor necrosis factor alpha, or IL-2, thus indicating that the clone belongs to the Th2 type. YS1093 cells and their culture supernatant after antigen stimulation augmented the primed cytotoxic T lymphocyte killing activity at the effector phase. YS1093 cells having Th2-type characteristics made the homologous growing tumor regress in the tumor-bearing syngeneic mice when YS1093 cells were transferred into the tumor-bearing mice i.v. The in vivo tumor regression initiated by YS1093 cell transfer essentially required the presence of CD8+ T cells in the tumor-bearing hosts, thus suggesting that some specific Th2 cells are positively involved in tumor regression by activating primed CD8+ cytotoxic T lymphocytes against the homologous tumor in situ.

Adoptive Transfer↗
PubMed1996

Involvement of transcription factors TCF-1 and GATA-3 in the initiation of the earliest step of T cell development in the thymus.

Flow cytometric and immunocytochemical analyses of murine fetal thymus (FT) cells with antibodies to various surface markers and transcription factors reveal that the synthesis of TCF-1 and GATA-3 protein begins simultaneously in a fraction of the most immature population of FT cells, which have the phenotype of CD4-CD8-CD44+CD25-. No TCF-1-producing cells is found in the fetal liver (FL). In CD44+CD25- FT cells, the production of TCF-1 is immediately followed by intracellular expression of CD3 epsilon. It is also found that the T cell development from FL, but not FT, progenitors in the FT organ culture system is severely inhibited by the addition of antisense oligonucleotides for either TCF-1 or GATA-3. These results strongly suggest that TCF-1 and GATA-3 play essential roles in the initiation of the earliest steps of T cell development in the thymus.

3T3 Cells↗
PubMed1996

Association of p53 gene mutation with decreased chemosensitivity in human malignant gliomas.

Loss of p53 function is involved in tumorigenesis of various human cancers, but the relation between mutation of the p53 tumor-suppressor gene and the chemo- and radiosensitivity of tumors remains unclear. Mutated p53 gene in malignant glioma is often associated with progression and recurrence of malignancy, and these events are closely linked with increased resistance to both chemotherapy and radiation. We have examined the status of the p53 gene in malignant gliomas obtained from 34 patients (glioblastoma: 29 cases, anaplastic astrocytomas: 5 cases). The chemosensitivities of these specimens using 28 kinds of anti-cancer agents were determined using an in vitro assay system. Overall, 12 mutated cases of p53 gene were found in malignant glioma samples. The mean numbers of effective agents were 0.58 for the tumor samples with p53 mutations and 5.00 for tumors without mutations. Our data indicate that p53 gene mutation predisposes to decreased cell killing via chemotherapy in malignant gliomas.

Adolescent↗
PubMed1996

Characterization of a human glycoprotein with a potential role in sperm-egg fusion: cDNA cloning, immunohistochemical localization, and chromosomal assignment of the gene (AEGL1).

Acidic epididymal glycoprotein (AEG), thus far identified only in rodents, is one of the sperm surface proteins involved in the fusion of the sperm and egg plasma membranes. In the present study, we describe the isolation and characterization of cDNA encoding a human glycoprotein related to AEG. Although this protein, designated ARP (AEG-related protein), is not the ortholog of rodent AEG, it resembles AEG in that it is an epididymal secretory glycoprotein that binds to the postacrosomal region of the sperm head. The fact that no AEG mRNA can be detected in the human epididymis suggests that ARP might be the functional counterpart of rodent AEG. The gene encoding ARP (AEGL1) was mapped by fluorescence in situ hybridization to 6p21.1-p21.2. This result indicates that AEGL1 and the mouse gene for AEG are located in the chromosomal segments with conserved syntenies.

Acrosome↗
PubMed1996

Survival time and prevention of side effects of intraperitoneal hyperthermic perfusion with mitomycin C combined with surgery for patients with advanced gastric cancer.

In an attempt to prevent postoperative intraperitoneal recurrence in patients with advanced gastric cancer and consequently to improve survival time, we treated patients with intraperitoneal hyperthermic perfusion (IPHP) using mitomycin C (MMC) combined with surgery. There were 60 patients with advanced gastric cancer who were treated with IPHP (long-term study) group, and the survival of this group was compared with the outcome in 52 patients with advanced gastric cancer treated with surgery alone (control group). To avoid or diminish side effects derived from scald injury of the peritoneal surface due to IPHP, 50 mg/kg of cimetidine was given intravenously just before administration of IPHP. For prophylaxis of anastomotic leakage, duodenostomy using a Foley catheter was performed. The 60 patients who were treated with IPHP lived longer than the 52 patients in the control group (p = 0.000610). The 3 year survival rate was 45 percent for the former compared with 16 percent for the latter. The intravenous administration of cimetidine just prior to IPHP protected the peritoneoserosal surface from scald injury, even though the heated perfusate exposure was at 44.3-46.3 degrees C for 2 hours. Because the intraabdominal pressure within the duodenum and jejunum was decompressed postoperatively through catheter duodenostomy and the peritoneoserosal surface was protected from scald injury caused by IPHP, anastomotic leakage in the study group was nil. Therefore, IPHP treatment plus aggressive surgery combined with pre-IPHP cimetidine administration are indicated for patients with advanced gastric cancer. The side effects of IPHP and postoperative morbidity can thus be reduced and a favorable outcome obtained.

Adult↗
PubMed1996

Increase in number of Weibel-Palade bodies and endothelin-1 release from endothelial cells in the cadmium-treated rat thoracic aorta.

Male rats received daily intraperitoneal injections of cadmium sulphate (2.0 mg/kg) for 3 (Cd-3 group), 6 (Cd-6 group) and 8 days (Cd-8 group). The blood samples were prepared for endothelin (ET)-1 assay, and the thoracic aorta was investigated by both electron microscopy and immunoelectron microscopy using anti ET-1 sera. The plasma ET-1 concentrations of both Cd-6 and Cd-8 groups increased significantly in a cumulative dose-dependent manner. The cadmium-treated rat aorta showed an increase in the number of Weibel-Palade (WP) bodies in endothelial cells, and degranulation and exocytosis of WP bodies occurred exclusively in the Cd-8 group. Immunoreaction for ET-1 was localized preferentially in WP bodies of both cadmium-treated and control groups, and in the rough endoplasmic reticulum of the cadmium-treated groups only. Reactivity was also found on the WP bodies undergoing exocytosis in the Cd-8 group. Cadmium intoxication induces an increase in number of ET-1-storing WP bodies in the rat aorta endothelium. The enhancement of extracellular release of their contents by exocytosis results in elevation of the plasma ET-1 concentration.

Animals↗
PubMed1996

Fine surface structure of enterotoxemic Escherichia coli O139:K12 strains associated with swine edema disease.

The fine structure of the cell surface of seven enterotoxemic Escherichia coli (ETEEC) O139:K12 strains isolated from piglets with edema disease were examined electron microscopically using both the negative-staining method and the freeze-substitution fixation method. Densely packed, fine fibers were observed; they consisted of a capsule layer approximately 25 nm thick around the cell surfaces of strains 107/86, IW-2, ED-3, ED-43, and ED-61, all of which have a capacity to adhere strongly to HEp-2 cells. In contrast, no such structure was observed on the surface of strains RK-O139 or ED-1, both of which adhere only weakly to HEp-2 cells. These results suggest that the capsule structure might be associated with the ability to adhere to HEp-2 cells and, as a result, also potentially play some role in ETEEC infection.

Animals↗
PubMed1996

Natural history of abnormal conduction and its relation to prognosis in patients with dilated cardiomyopathy.

To investigate the natural history of disturbances in ventricular activation, atrioventricular conduction, and ventricular cavity size, we retrospectively studied 58 patients from a total of 296 patients with dilated cardiomyopathy seen within 4 years. A total of 309 computerised electrocardiograms (ECGs) and 135 M-mode echocardiograms were analysed. In the majority of the patients, PR interval, QRS duration and QT interval prolonged progressively, though heart rate changed little. Their increase was much more striking in patients who died (n = 10) or had a pacemaker inserted (n = 9), compared to that in the clinically stable patients, though at entry all these values, as well as age and left ventricular cavity size, were similar. There were no significant differences between patients who died and those with a pacemaker inserted, except for QRS axis, which had shifted rightwards in 8 out of 10 who died, but only in 3 of 9 who subsequently had a pacemaker inserted and 14 of the 29 stable patients. A QRS duration over 160 ms was found in 8 out of the 10 patients who died, 6 of 9 who had a pacemaker and only in 5 out of the 39 stable patients (P < 0.001). The sum of PR interval and QRS duration over 375 ms was not found in any stable patient but was present in 6 of the 7 patients who were in sinus rhythm and died (P < 0.001). Left ventricular cavity size also increased with time, but did not correlate significantly with ECG progression, nor did it identify patients who subsequently died. Thus, a combination of increasing PR interval and QRS duration, particularly along with rightwards shift of QRS axis, appears to be a marker of high risk in patients with dilated cardiomyopathy.

Adult↗
PubMed1996

Diagnosis of premature rupture of the membranes in preterm patients, using an improved AFP kit: comparison with ROM-check and/or nitrazine test.

OBJECTIVE: We developed a new kit for detecting AFP in leaked amniotic fluid. Later, we developed an improved AFP kit utilizing the same anti alpha-fetoprotein (AFP) monoclonal antibody. In this study, we evaluate the clinical usefulness of this improved kit in the diagnosis of preterm premature rupture of membranes (PROM). METHODS: We compared this improved AFP test with the ROM-check and/or the nitrazine tests in 46 preterm patients. RESULTS: The ROM-check and nitrazine tests showed a diagnostic accuracy of 89.1 and 87.0%, respectively, compared with 95.7% with the improved AFP test. The sensitivity of the improved AFP test on cervical samples was significantly higher than that of the nitrazine test on vaginal samples (P < 0.05). The reaction time with the improved AFP kit test is 90 s. CONCLUSION: This study has confirmed a great clinical utility of the improved AFP test kit as a method of PROM diagnosis.

Amniotic Fluid↗
PubMed1996

The potentiation of nitroglycerin-induced relaxation by PKG inhibition in rat aortic rings.

1. In rat aortic rings precontracted by phenylephrine, H7 (10(-5)M) and staurosporine (10(-7)M), which inhibit PKA, PKG and PKC, and H-89 (10(-6)M), which inhibits PKA and PKG, potentiated relaxations induced by nitroglycerin. Forskolin-induced relaxations were not affected by H7 (10(-5)M). 2. Nitroglycerin-induced relaxations were not affected by calphostin-C (10(-7)M), which inhibits PKC, H-89 (10(-7)M), which inhibits PKA, and staurosporine (2 x 10(-9)M), which inhibits PKC. 3. Iberiotoxin (3 x 10(-8)M), an inhibitor of large conductance Kca channels, partly inhibited the relaxation induced by nitroglycerin and completely inhibited the potentiating effect of H7 on nitroglycerin-induced relaxations. 4. The potentiating effect of zaprinast (10(-5)M), an inhibitor of cGMP-phosphodiesterase, on nitroglycerin-induced relaxation was not affected by iberiotoxin. In the presence of methylene blue (10(-5)M), an inhibitor of guanylate cyclase, the residual relaxing response to nitroglycerin was not affected by H7, but it was inhibited by iberiotoxin. 5. These results suggest that the potentiation of nitroglycerin-induced relaxation by H7, staurosporine and H-89 may be due to inhibition of PKG.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗