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Biomedical subjects

T Fujiwara

Publications and source records attributed to T Fujiwara.

At least 685 records · Page 38Linked to original sources
PubMed1994

Gastrin receptor gene expression in several human carcinomas.

Gastrin has been shown to enhance the growth of various human tumors. The present study was designed to examine the gastrin receptor gene expression in various human carcinoma cell lines and in surgically resected carcinoma tissues. By Northern blot analysis, gastrin receptor mRNA was detected in 3 out of 7 small cell lung carcinoma cell lines. Gastrin receptor mRNA was also expressed in one out of 8 colon carcinoma cell lines and 2 out of 10 colon carcinoma tissues. Moreover, one of two small cell carcinoma cell lines of the stomach clearly expressed gastrin receptor mRNA. However, none of the gastric adenocarcinoma cell lines or surgically resected gastric adenocarcinomas tested had any detectable expression of gastrin receptor gene. These findings may suggest a role of gastrin receptor in the growth and differentiation of certain human carcinomas.

Adenocarcinoma↗
PubMed1994

Coexistence of choriocarcinoma and hepatoid adenocarcinoma in the stomach.

The case is presented of a 46 year old woman who had a gastric tumor with components of choriocarcinoma, hepatoid adenocarcinoma and common types of adenocarcinoma. Although two histologic types of tumor producing carcinoplacental or carcinofetal proteins were contained within the tumor, immunohistochemical analyses, especially of placental alkaline phosphatase, clearly showed that each component was present separately within the same tumor. It was only hepatoid adenocarcinoma cells that permeated the lymph and blood vessels. After the recurrence, the serum level of alpha-fetoprotein (AFP) markedly elevated, but that of human chorionic gonadotropic beta-subunit (hCG-beta) was always within normal range. These findings indicate that in the present case the hepatoid adenocarcinoma component was more aggressive in growth than the choriocarcinoma component.

Adenocarcinoma↗
PubMed1994

A flow cytometric method for measurement of hydrogen peroxide generation by pediatric polymorphonuclear leukocytes stimulated by Staphylococcus aureus and Escherichia coli.

The generation of hydrogen peroxide (H2O2), one of the reactive oxygen species, by polymorphonuclear leukocytes (PMN) stimulated by Staphylococcus aureus and Escherichia coli was studied in infants by cytofluorography. After heparinized whole blood was incubated with bacteria for 60 min, generated H2O2 was measured. The positive rate of H2O2 generation of PMN and mean fluorescent intensity of positive PMN stimulated by S. aureus and E. coli were significantly reduced in infants aged < 1 year and H2O2 generation increased with advancing age. In 10-15 year old children, the level of generated H2O2 reached adult levels. When sera from 1 year old children were added to separated PMN from healthy adults, H2O2 generation was reduced. In contrast, H2O2 generation by PMN from 1 year old children was increased by the addition of adult sera. These results suggest that the ability to generate H2O2 in response to S. aureus and E. coli is lower in infants and that such reduced activity may be related to the susceptibility of such infants to S. aureus and E. coli infections.

Adolescent↗
PubMed1994

Effect of varicella zoster virus antigen-antibody complexes on hydrogen peroxide generation by human polymorphonuclear leukocytes.

Hydrogen peroxide (H2O2) generation by human polymorphonuclear leukocytes (PMN) incubated with varicella zoster virus (VZV) antigen was studied by cytofluorography. Hydrogen peroxide generation was detected in the presence of VZV-seropositive sera. When seropositive sera were heat-inactivated, H2O2 generation was reduced. When PMN were pre-incubated with Leu-11b, a monoclonal antibody to the Fc receptor on PMN, H2O2 generation was also reduced. These results suggest that VZV antigen-antibody-complement complexes induce H2O2 generation by PMN after these complexes attach to Fc receptors on PMN.

Antibodies, Viral↗
PubMed1994

Biophysical properties of protein-free, totally synthetic pulmonary surfactants, ALEC and Exosurf, in comparison with surfactant TA.

An artificial pulmonary surfactant prepared from chloroform-methanol extract of bovine pulmonary surfactant (surfactant TA) has been shown to be effective in both the prevention and the treatment of respiratory distress syndrome in premature babies. Recently, two types of protein-free totally synthetic surfactants, artificial lung expanding compound (ALEC) and Exosurf, have been evaluated in clinical trials of surfactant therapy. Artificial lung expanding compound was used initially as a dry powder, but is now prepared as a crystalline suspension in saline at 4 degrees C. In this study we compared the biophysical properties of three different forms of ALEC (dry powder, crystalline suspension at 4 degrees C and 37 degrees C), Exosurf and surfactant TA (Surfacten) using a modified Wilhelmy surface balance and a pulsating bubble surfactometer. Surface activity of a crystalline suspension of ALEC in cold saline was no better than the dry powder of ALEC. Surfactant activity of ALEC was improved by addition of hydrophobic surfactant protein B and C (SP-B, SP-C) which are important constituents of surfactant TA. Surface properties of ALEC in any form and Exosurf were not superior to those of surfactant TA. These results suggest that a surfactant which contains SP-B and SP-C does not necessarily have to be dry or crystalline for an effective exogenous surfactant.

Adsorption↗
PubMed1994

Detection and characterization of a functional complex of human immunodeficiency virus type 1 integrase and its DNA substrate by UV cross-linking.

To analyze the association of the human immunodeficiency virus type 1 integrase (IN) protein with DNA substrates, we applied a shortwave UV cross-linking method to the in vitro integration system. Three photoadduct bands were detected on sodium dodecyl sulfate-polyacrylamide gels. The appearances of these photoadducts were examined with various substrates and under several incubation conditions. Our data suggest that one of these photoadducts is derived from the sequence- and strand-specific bound state of the early phase of the integration reaction before the 3' processing reaction. We also show that most of the photoadduct complexes are competent for integration even after UV irradiation.

Base Sequence↗
PubMed1994

Idiopathic AA amyloidosis manifested by autonomic neuropathy, vestibulocochleopathy, and lattice corneal dystrophy.

A 69-year-old Japanese woman with non-familial amyloidosis had polyneuropathy and profound autonomic neuropathy, and kappa chain monoclonal gammopathy. Immunohistopathological examination showed protein AA and protein AP in the amyloid deposits. She showed involvement of the vestibulocochlear nerve and lattice dystrophy of the cornea. Vestibulocochleopathy and corneal lattice dystrophy have been reported in familial amyloid polyneuropathy type IV, Finnish type, but never in non-familial amyloidosis.

Aged↗
PubMed1994

Ischemic preconditioning elevates cardiac stress protein but does not limit infarct size 24 or 48 h later in rabbits.

We investigated whether ischemic preconditioning (PC) produced a second window of protection by delayed synthesis of cardioprotective proteins. Anesthetized open-chest rabbits were subjected to 30 min of coronary occlusion and 3 h of reperfusion. PC was elicited by 5 min of ischemia and was separated from sustained ischemia by 5 min, 2 h, or 24 h of reperfusion. Infarct size (% area at risk) was markedly limited by PC with 5 min of reperfusion when compared with controls (13.3 +/- 2.5 vs. 46.8 +/- 7.0%; P < 0.05). This protective effect was lost when the interval between PC and sustained ischemia was extended to 2 h (47.8 +/- 4.8%; P = NS vs. control) and did not reoccur even when it was extended to 24 h (44.2 +/- 6.5%; P = NS vs. sham-operated control). To potentiate induction of heat shock proteins (HSPs), a PC protocol involving four 5-min episodes of ischemia and reperfusion was also used and was separated from sustained ischemia by 24 or 48 h of reperfusion. However, neither of these protocols was protective, and limitation of infarct size was not observed (55.5 +/- 5.9 and 53.4 +/- 6.5% in 24 and 48 h of reperfusion, respectively; P = NS vs. corresponding sham-operated control). Myocardial expression of HSPs was examined using a monoclonal antibody against 72- to 73-kDa HSP in additional rabbits. Immunoreactivity was observed in the myocardium at 24 and 48 h after PC, but not immediately after PC.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Effects of vinconate and pentobarbital against postischemic alterations in spirodecanone binding sites in the gerbil brain.

We investigated the effects of vinconate and pentobarbital against the alterations in spirodecanone binding in the gerbil striatum and hippocampus 5 h and 7 days after 10 min of cerebral ischemia, using receptor autoradiography. Vinconate and pentobarbital were given intraperitoneally 10 and 30 min prior to ischemic insult, respectively. The spirodecanone binding in vehicle-treated gerbils subjected to ischemia was unchanged in the brain 5 h after recirculation, compared with that in sham-operated animals. Seven days after ischemia, a significant elevation in the spirodecanone binding was observed in the striatum and the stratum radiatum of the hippocampal CA1 sector and the hippocampal CA3 sector of the vehicle-treated animals. Other regions showed no significant change in the binding. Vinconate and pentobarbital showed no significant change in the striatum and hippocampus 5 h after ischemia. However, the administration of vinconate inhibited a significant elevation in the spirodecanone binding in the lateral striatum and the stratum radiatum of hippocampal CA1 sector 7 days after ischemia. Pentobarbital also prevented a significant elevation only in the lateral striatum. A histological study revealed that cerebral ischemia caused severe neuronal damage in the lateral striatum and hippocampal CA1 and CA3 sectors. However, ischemic neuronal damage was not observed in the dentate gyrus. An immunohistochemical study also showed that numerous reactive astrocytes were evident in the hippocampus, particularly in the hippocampal CA1 sector, 7 days after ischemia. The present study demonstrates that cerebral ischemia can cause a conspicuous elevation in spirodecanone binding in the striatum and hippocampus. They also suggest that the postischemic elevation in the spirodecanone binding is partly prevented by treatment with vinconate and pentobarbital. These results suggest that the postischemic elevation in spirodecanone binding sites may reflect expression of reactive astrocytes.

Animals↗
PubMed1994

Endothelin-1-selective receptor in the arterial intima of patients with hypertension.

Endothelin-1 is a potent vasoconstrictor produced by vascular endothelial cells. A recently cloned endothelin-1-selective receptor, the endothelin-A receptor, mediates the vasoconstrictive action of endothelin-1. Because endothelin-1 also possesses mitogenic properties, it may play a role in regulating the proliferation of intimal smooth muscle cells. In this study, we analyzed the expression of endothelin-A receptor gene in the thickened arterial intima of patients with hypertension. Internal mammary artery specimens obtained from 12 patients undergoing cardiovascular surgery were subjected to in situ hybridization using a digoxigenin-labeled cRNA probe. High, homogeneous signals of endothelin-A receptor mRNA were observed in the medial smooth muscle cells of all vessels examined but not in the endothelial cells. Patients with hypertension displayed more severe intimal thickening than those without hypertension. Immunohistochemical analysis suggested that almost all of the intimal proliferative cells originated from smooth muscle cells. In contrast to media, endothelin-A receptor mRNA signals in intimal smooth muscle cells were low and heterogeneous. In the thickened arterial intima of hypertensive patients, the signals were detected just beneath the luminal endothelium but not deep in the intimal smooth muscle cell layer. By contrast, staining with anti-alpha-smooth muscle actin antibody was more intense in the deep layer than in the subendothelium. These findings suggest that the modulation of endothelin-A receptor gene expression in smooth muscle cells differs between the intima and media. Its regulated expression in intimal smooth muscle cells might affect the proliferative activity of these cells in patients with hypertension.

Aged↗
PubMed1994

Troglitazone prevents the inhibitory effects of inflammatory cytokines on insulin-induced adipocyte differentiation in 3T3-L1 cells.

Tumor necrosis factor (TNF) is implicated in wasting syndromes and insulin resistance in chronic infection and obese-linked diabetes. TNF (10 ng/ml) inhibited adipocyte differentiation of 3T3-L1 cells, and in these TNF treated cells little insulin-stimulated glucose uptake was observed. Treatment of 3T3-L1 cells with troglitazone (1-10 microM) partially prevented this inhibitory effect of TNF on adipogenesis, and enhanced expression of C/EBP alpha and GLUT4, even in the presence of TNF. Troglitazone also prevented the inhibitory effects of interleukin-1, interleukin-6, and leukemia inhibitory factor, but not of transforming growth factor beta on adipocyte differentiation of 3T3-L1 cells. These effects might contribute to the antidiabetic effect of troglitazone in obese diabetic animals.

3T3 Cells↗
PubMed1994

Synergistic effect between intraneoplastic methotrexate and radiation on experimental intracerebral rat gliosarcoma.

Methotrexate (MTX) alone has a limited effect against malignant brain tumors, but we previously demonstrated a beneficial synergism between MTX and radiation therapy (XRT) against RT-9 gliosarcoma. Because the beneficial effects of that study were limited by systemic toxicity and poor brain penetration of MTX, we have continued our studies using direct intracerebral MTX therapy. Male CD-Fisher rats with intracerebrally implanted RT-9 gliosarcoma and indwelling brain tumor catheters were treated with intracerebral injections of MTX, whole-brain XRT, or a combination of both. MTX was given either as one of two "high-dose" treatments, on the basis of whole-body doses, or two "low-doses," on the basis of average brain weight. MTX alone at lower doses and XRT alone each prolonged survival moderately. High-dose MTX was highly toxic, but low-dose MTX was well tolerated. Combined MTX and XRT caused a significant prolongation of survival in all animals that survived treatment long enough to die from tumor growth.

Animals↗
PubMed1994

Attenuation of clonidine-induced vascular alpha 1-antagonistic action in hypercholesterolemic rabbit common carotid arteries.

We examined the effect of hypercholesterolemia on vasodilatory responses to clonidine in isolated and perfused rabbit common carotid arteries that had been preconstricted by phenylephrine. The responses decreased in rabbits fed an atherogenic diet for 4 or 8 weeks, whereas the responses to acetylcholine, nitroglycerin and substance P were not changed after the cholesterol feeding. Attenuated responses to clonidine were maintained for 24 weeks after cessation of the atherogenic diet, suggesting that this response might be an early marker of atherosclerosis.

Adrenergic alpha-1 Receptor Antagonists↗
PubMed1994

2-Methyl-5-HT-induced vasoconstrictions mediated via alpha 1-adrenoceptors in rabbit common carotid arteries.

We investigated the effects of 2-methyl-5-HT and 1-phenylbiguanide on isolated and perfused rabbit common carotid arteries by a cannula insertion method. 1-Phenylbiguanide produced neither vasoconstriction nor dilation. On the other hand, 2-methyl-5-HT produced only a vasoconstriction, and the dose-response curve was shifted to the right in parallel by treatment with either ketanserin or bunazosin, although methysergide and granisetron had no antagonistic effect. Moreover, the vasoconstriction was not inhibited by guanethidine and imipramine. These data showed that 2-methyl-5-HT acts as an alpha 1-adrenoceptor agonist but not as a 5-HT3-receptor agonist in this vessel.

Adrenergic alpha-1 Receptor Agonists↗
PubMed1994

Histopathological investigation on salt-loaded stroke-prone spontaneously hypertensive rats, whose biochemical parameters of renal dysfunction were ameliorated by administration of imidapril.

Our previous studies showed that imidapril prevented the occurrence of cerebral stroke and ameliorated biochemical parameter changes of renal dysfunction at a dose that did not inhibit the progression of hypertension in salt-loaded stroke-prone spontaneously hypertensive rats (SHRSP). To confirm these findings, a histopathological investigation was conducted on the kidney of salt-loaded (from 11 to 16 weeks of age) SHRSP, which was the subject of the preceding study. Their brains and hearts were also examined. Histopathologically, renal lesions such as fibrinoid necrosis and proliferative arteritis of small calibration arteries, necrotizing glomerulitis and tubular degeneration, and cerebral hemorrhage and slight cardial hypertrophy were observed in salt-loaded control SHRSP. The occurrence of these lesions were prevented in a dose-dependent manner by the administration of imidapril (1 and 2 mg/kg/day). Especially, the preventive effects on the renal lesions were apparently noted. Enalapril also prevented these renal lesions, but its preventive effects were weaker than those of imidapril at the same dose (2 mg/kg/day). It became evident from the results of the present and previous studies that imidapril reduced renal biochemical and histopathological injuries.

Animals↗
PubMed1994

Unresponsiveness of antidonor cytotoxic T cells in a long-term stable renal transplant recipient.

The antidonor immune response was examined in a one haplotype-mismatched renal transplant recipient with an allograft that had been well-functioning for more than 10 years. Although the relative response of the mixed lymphocyte reaction (MLR) was (45.8)% and the MLR responder cells stimulated by donor cells produced measurable amounts of interleukin-2 (IL-2) (11.6 U/ml), the cytotoxic T lymphocytes (CTL) could not be generated against donor cells, even with exogenous IL-2. These results indicate that antidonor CTL precursors were either deleted or inactivated in this recipient.

Adult↗