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Biomedical subjects

S Otani

Publications and source records attributed to S Otani.

At least 343 records · Page 19Linked to original sources
PubMed1981

[Change of left ventricular segment length by nitroglycerin measured by biplane coronary cineangiography in man (author's transl)].

Left ventricular size at different portions was evaluated following the administration of nitroglycerin to find whether there is any regional difference in the amount of shortening. In 6 patients with old myocardial infarction, biplane coronary cineangiograms were obtained before and after sublingual administration of nitroglycerin of 0.3 mg. The coordinates of the bifurcations of the left coronary artery at multiple sites were measured on the postero-anterior and lateral films and the spatial lengths (L) between any paired two points were calculated frame by frame covering one cardiac cycle. The maximum length (Lmax) was 63.2 +/- 3.1 (SE) mm before nitroglycerin as a whole and was 61.4 +/- 2.9 mm after nitroglycerin, showing no significant change. The minimum length (Lmin) also showed no significant change after nitroglycerin; from 56.1 +/- 2.9 to 54.9 +/- 2.6 mm. However, at the free wall, Lmax after nitroglycerin was reduced by 4.5 +/- 2.5%, and Lmax at the anterior septum was also reduced by 3.0 +/- 1.3%. Lmax at the base was unchanged after nitroglycerin. Lmin at the free wall and at the anterior septum were also reduced after nitroglycerin, 4.4 +/- 2.6 and 2.9 +/- 1.2%, respectively, and it was unchanged at the base. Since a reduction in the left ventricular size is effective in reducing myocardial oxygen demand and is effective in treating myocardial ischemia, it was suggested that nitroglycerin is more effective in relieving ischemia at the free wall and septum and less effective at the base.

Cineangiography↗
PubMed1981

Studies on intrahepatic cholestatic: intrahepatic cholestasis induced in rats by the culture supernatant of activated lymphocytes.

When lymph node lymphocytes from sensitized guinea pigs were stimulated with a specific antigen in vitro, and their culture supernatants injected into the mesenteric vein of rats, a marked reduction of bile flow and bile secretion was seen. Gel filtration of this active principle revealed that the active material has a molecular size similar to that of the macrophage migration inhibitory factor (MIF). Histologically, dilated bile canaliculi with decreased microvilli were observed by electron microscopy in rat liver after injection of culture supernatant. No such change was observed in rats after injection of the supernatant of lymphocyte cultures prepared from non-sensitized guinea pigs. These results strongly suggest that the sensitized lymphocytes produce a factor (or factors) which causes intrahepatic cholestasis when stimulated with a specific antigen.

Animals↗
PubMed1981

Possible involvement of macrophage-mediated hepatocytotoxicity in chronic active hepatitis: the induction of liver cell injury by culture supernatant of MAF-activated macrophages.

When peripheral blood lymphocytes from patients with various types of hepatitis were stimulated in vitro with liver specific protein, lymphocyte transformation and MIF production were demonstrated in many cases, especially in chronic active hepatitis. The culture supernatant of these activated lymphocytes was also shown to contain MAF, a kind of lymphokine, which activated the peritoneal macrophages of guinea pigs. When the culture fluid of MAF-activated macrophages was added to isolated liver cells, a significant inhibition of their albumin biosynthesis was detected. The active principle which caused the impairment of liver function was fractionated by gel filtration using a Sephadex G-75 column, and it was found that the active material was a protein-like substance with a molecular weight of about 10,000-40,000. The results suggest the possibility that the soluble substance released from the activated macrophage may be involved at least partially in the immunological pathogenesis of chronic active hepatitis among many other immunological processes.

Adult↗
PubMed1981

Studies on intrahepatic cholestasis in drug-induced allergic hepatitis: intrahepatic cholestasis induced in the rat by the culture supernatant of activated lymphocytes.

A marked reduction in bile flow and bile acid excretion was whenever peripheral lymphocytes from patients with drug-induced allergic intrahepatic cholestasis were stimulated with a specific drug in vitro in the presence of a soluble liver-specific antigen fraction, and their culture supernatant injected into the mesenteric vein of rats. A gel filtration study of the active fraction of the supernatant that caused a reduction in bile flow, suggested that the molecular size of this active principle is similar to that of the macrophage migration inhibitory factor (MIF). Histologically, dilated bile canaliculi with decreased microvilli were observed via electron microscopy in rat liver after injection of culture supernatant. No such changes were observed in rats after injection of the supernatant of a lymphocyte culture similarly prepared from normal individuals. These results strongly suggested that sensitized lymphocytes obtained from patients with drug-induced intrahepatic cholestasis produce a factor (of factors) causing cholestasis when stimulated with a specific drug in the presence of liver-specific antigen fractions.

Animals↗
PubMed1980

Immunological studies on drug-induced allergic hepatitis--hepatocellular injury by macrophage-mediated cytotoxicity.

When the peripheral blood lymphocytes from patients with drug-induced allergic hepatitis were stimulated with a specific drug in vitro in the presence of a liver cytosol fraction containing liver specific antigen, lymphocyte transformation was seen in eight out of 11 patients. The macrophage activating factor (MAF), a kind of lymphokines, was also detectable in the culture medium of activated lymphocytes from seven out of eight patients who showed positive blastogenesis evaluated the uptake of 3H-glucosamine into macrophages. MAF-activated macrophages exhibited a cytotoxic effect on separated liver cells resulting in a marked inhibition of albumin synthesis. This macrophage-mediated cytotoxicity was also observed in eight out of 11 patients who showed positive lymphocyte transformation. These observations suggest that macrophage-mediated cytotoxicity may play some role in the pathogenesis of drug-induced allergic hepatitis.

Adult↗
PubMed1980

Effect of urethan on polyamine and DNA synthesis in the regenerating rat liver.

When a single dose of urethan was injected into the peritoneal cavity of rats immediately after partial hepatectomy, DNA synthesis was delayed by 12 h. The induction of ornithine decarboxylase which was induced biphasically following partial hepatectomy was also reduced and delayed by 14-15 h by the administration of urethan. S-Adenosylmethionine decarboxylase activity in urethan-treated rat liver at 20 h and 29 h after operation was significantly lower than that of untreated animals. This enzyme activity was shown to increase thereafter, reaching a higher level than in untreated rats at 37-42 h. Hepatic spermidine content changed biphasically in a manner similar to DNA synthesis. These results suggest that the activities of ornithine decarboxylase and S-adenosylmethionine decarboxylase may correlate with DNA synthesis and that an increase of spermidine concentration is necessary to DNA synthesis.

Adenosylmethionine Decarboxylase↗
PubMed1980

Increases in coronary vascular resistance related to high arterial oxygen tension in dogs.

It is known that oxygen inhalation induces coronary vessel constriction as well as brings about a reduction in myocarial oxygen consumption. The present study was performed to clarify whether or not this constriction of the coronary vessels resulting from oxygen is secondary to the reduction in myocardial oxygen consumption. The regional myocardium in 12 mongrel dogs was perfused with femoral arterial blood at a constant rate of flow. While maintaining myocardial oxygen consumption equal by adjusting heart rate, coronary vascular resistance was compared under the two following conditions: 1) perfusion of the coronary artery with the dog's own femoral arterial blood (pO2 : 95 +/- 14 mmHg) and 2) perfusion with blood with a high level of oxygen tension (pO2 : 497 +/- 56 mmHg). Coronary vascular resistance was increased (p < 0.001) from 3.00 +/- 1.25 to 3.36 +/- 1.28 mmHg/ml/min by incresing the pO2 in the perfusing blood, even though myocardial oxygen consumption was kept at the same level. This increase in coronary vascular resistance resulting from the increase in oxygen tension was independent of the coronary perfusion rate as well as independent of the presence or absence of myocardial ischemia. This suggests that coronary vasoconstriction due to oxygen is not secondary to decreases in myocardial oxygen demand.

Animals↗
PubMed1980

Identification of the corticosteroid-sensitive cells in antibody responses in mice.

To elucidate the cellular basis of corticosteroid-induced suppression of antibody response, the immune responses of hydrocortisone-pretreated mice against various antigens, both thymus-dependent and thymus-independent antigens, were compared with those of normal mice. The in vitro antibody responses to some antigens were also studied by a combination of lymphocyte subpopulations and macrophages from normal and hydrocortisone-treated mouse spleen. It was shown that the antibody responses to all antigens tested were significantly reduced by hydrocortisone. Experimental results in vitro also suggested that the susceptibility of splenic B cells to hydrocortisone treatment was higher than that of T cells, although the helper T cell function was significantly suppressed by hydrocortisone. No impairment of macrophage functions by hydrocortisone was observed in our experiments.

Adrenal Cortex Hormones↗
PubMed1980

Antibody activities of immunoglobulins in anti-leptospiral horse sera.

Antileptospiral sera from hyperimmunized horses were fractionated by gel filtration on Sephadex G-200 or by starch block electrophoresis. The fractions were examined quantitatively for leptospiricidal, agglutinating and complement fixing activities. The leptospiricidal activity was higher in the 78 globulin fraction than in the 19S globulin fraction, while the agglutinating activity was shared by both the fractions being higher in the 19S fraction. Complement fixing activity was found evenly in both the fractions. Leptospiricidal and complement fixing activities were higher in gamma-globulin than in T-globulin, while the agglutinating activity was comparable in the two globulin fractions. That is, the agglutinating activity may not always behave along with the leptospiricidal activity. The results were discussed in connection with the therapeutic antiserum product for human use.

Agglutination Tests↗
PubMed1980

Analyses for neutralizing activities of immunoglobulin fractions in anti-leptospiral horse antiserum.

The 7S and 19S fraction isolated from hyperimmunized antileptospiral horse sera by Sephadex G-200 gel filtration and gamma- and T-globulin fractions from the antisera by starch block electrophoresis were studied for neutralizing (leptospiricidal) activities against infection with Leptospira. The activity was determined by the intracutaneous method with virulent Shibaura Strain of Leptospira interrogans serovar copenhageni. No significant difference in regression coefficient was observed between the neutralization line with the 19S globulin fraction and that with the 7S globulin fraction, whereas a significant difference in the regression coefficient was observed when the gamma- and T-globulin fractions were compared; the regression coefficient with T-globulin was consistently larger than that with gamma-globulin.

Animals↗
PubMed1980

Lymphocyte activation by purified carrageenan.

The induction of polyclonal antibody production and mitogenic response by purified carrageenan was studied in vitro by using spleen cells. It was shown that kappa-CGN, lambda-CGN, and iota-CGN induced significant responses in mice, hamsters, and rats. The less purified CGN also exhibited the polyclonal antibody production in mice. In addition, purified CGN exhibited mitogenic action on B cells and to a lesser extent, on thymocytes. Polyclonal antibody responses induced by purified CGN were not affected by removal of T cells, adherent cells, or iron powder phagocytic cells. These results suggest that CGN may activate B cells resulting in polyclonal antibody responses.

Animals↗
PubMed1979

A study of flavin-protein and flavoprotein-ligand interactions. Binding aspects and spectral properties of D-amino acid oxidase and riboflavin binding protein.

To study flavin-protein and flavoprotein-ligand interaction, the absorption, CD and MCD spectra of riboflavin, FAD, roseoflavin, the complexes of riboflavin and roseoflavin with riboflavin binding protein(RBP),D-amino acid oxidase(D-AO) and its complexes with ligands were observed in the spectral region of 310-600 nm and the binding properties of D-AO with di-substituted benzoate derivatives and of RBP with roseoflavin were also measured. The dimer of D-amino acid oxidase has a higher affinity for di-substituted benzoate derivatives than the monomer. The change in the absorption of FAD in D-AO caused by the binding of the first ligand to the dimer, which can bind two ligands, was similar to that caused by the binding of the second ligand. Roseoflavin could bind to RBP in a 1 : 1 ratio and the dissociation constant was 3.8 x 10(-8)M. The protein fluorescence of RBP was quenched by about 86% due to complex formation with roseoflavin. The MCD spectra showed similar patterns for all molecular complexes of riboflavin and FAD, with two negative extrema of ellipticity which probably correspond to the Faraday B-term, but the Faraday A-term could not be observed, suggesting that there was no degeneracy in the excited state of flavins. It is also suggested, based on a comparison of the absorption, CD and MCD spectra, that the vibronic structure of flavin was modified differently by each flavin-protein or flavoprotein-ligand interaction. Comparison of the absorption, CD and MCD spectra(310-600 nm) for roseoflavin and the roseoflavin-RBP complex revealed that there were five spectral components around 320, 340, 400, 500, and 550 nm in roseoflavin.

Carrier Proteins↗