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Biomedical subjects

N Kasai

Publications and source records attributed to N Kasai.

At least 199 records · Page 11Linked to original sources

Acetate kinase in the genus Veillonella: effect of succinate, serological cross-reactivity, and separation by electrophoresis.

Acetate kinases from the genus Veillonella were divided into two types: a succinate-stimulated enzyme and a succinate-independent enzyme. Three strains, V. parvula ATCC 17743 (antigenic group II), V. parvula ATCC 17744 (V), and V. parvula ATCC 10790 (VI), contained the succinate-stimulated enzyme. Among four types strains of V. alcalescens, three strains, ATCC 17747 (I), ATCC 17746 (III), and ATCC 17748 (VII), contained the succinate-independent enzyme, whereas only one strain, ATCC 17745 (IV), contained the succinate-stimulated enzyme. Small amounts of antiserum to the purified acetate kinase from V. alcalescens ATCC 17748 completely inhibited the purified and crude enzyme activity from the strain. Classification of the enzymes on the basis of stimulation by succinate was consistent with classification based on serological reactions using the antiserum as an independent parameter. The succinate-stimulated enzyme could be separated into two classes according to the degree of sensitivity to succinate: (i) enzymes from V. parvula ATCC 17744 and V. alcalescens ATCC 17745, which could be demonstrated on gel after electrophoresis by a histochemical method to be highly stimulated by the presence of succinate in the reaction mixture, and (ii) enzymes from V. parvula ATCC 10790 and V. parvula ATCC 17743, which could be easily demonstrated without succinate. Four groups of acetate kinases from the genus Veillonella were separated by gel electrophoretic mobility. The results showed that almost all enzymes from the seven type strains were heterogeneous at the molecular level.

Acetate Kinase↗

Platelet-aggregating immune complexes in idiopathic glomerulonephritis and SLE.

Immune complex-like material with a molecular weight of greater than 500,000 Daltons was detected in the majority of sera from patients with idiopathic glomerulonephritis, as well as in systemic lupus. In the Raji cell and Clq binding assays the glomerulonephritis sera gave, in general, negative results. Patients with membranous nephropathy, minimal change disease and Henoch-Schönlein purpura also gave positive results in the platelet test, in agreement with other tests not dependent upon complement fixation by the complexes. The amount of platelet-aggregating material detected in vitro correlated closely with in vivo depletion of intraplatelet amines, judged by serotonin concentrations; which suggests that this material may play a major role in platelet activation within the circulation.

Antigen-Antibody Complex↗

Platelet and plasma serotonin in glomerulonephritis. III: The nephritis of systemic lupus erythematosus.

Intraplatelet and plasma serotonin levels were measured in 269 samples from 44 patients with systemic lupus erythematosus (SLE) and clinical nephritis. The intraplatelet serotonin levels were depressed and the plasma serotonin levels were raised in lupus nephritis. There was a strong correlation between both lowered intraplatelet serotonin concentration and raised plasma "serotonin", and the overall clinical activity of the disease. This correlation was also observed in the majority of individual patients studied serially; the platelet serotonin levels correlated with both clinical and immunological tests. Serotonin uptake by platelets was significantly diminished, but there was no correlation between serotonin uptake and platelet serotonin levels. There was, however, a correlation between the amount of platelet-aggregating material in the serum and depression of intraplatelet serotonin. This study provides further evidence of in vivo platelet activation in SLE nephritis, and provides a measure of the activation in relation to the clinical and immunological activity of the disease.

Adolescent↗

Endotoxic glycolipid as a potent depressor of the hepatic drug-metabolizing enzyme systems in mice.

Inhibitory effects of the endotoxic glycolipid from Salmonella minnesota R595 on hepatic drug-metabolizing enzyme activities in mice were investigated, and the depressor activity of the glycolipid in the enzyme systems was confirmed. Among degradation products of lipopolysaccharides tested, lipid A preparations derived from the mild acetic acid hydrolysates of lipopolysaccharides were the most active, but the lipid A fractions prepared from the hydrolysates with 1 N-HCl were almost inactive. A degraded polysaccharide fraction from E. coli lipopolysaccharide was inactive. The activities of the glycolipid and the lipid A preparation were markedly reduced by treatment with alkaline-hydroxylamine, mild alkali or hydrazine. The data showed that the lipid A moiety of the glycolipid may be responsible for the inhibitory activity on the hepatic drug-metabolizing enzyme systems.

Aminopyrine N-Demethylase↗

Binding of bacterial lipopolysaccharide to histocompatibility-2-complex proteins of mouse lymphocytes.

The membrane binding sites for lipopolysaccharide (LPS) were isolated by affinity chromatography of the solubilized membranes prepared from 125I-labeled mouse B-cells and T-cells on an affinity adsorbent prepared by coupling Salmonella minnesota R595 LPS to activated Sepharose 4B. The membrane proteins bound to the affinity adsorbent and eluted with 1.0% Triton X-100 were analyzed according to their mobility on polyacrylamide gel electrophoresis in sodium dodecylsulphate. These membrane proteins were further identified by immunoprecipitation with specific antisera. Immunoglobulins, possibly immunoglobulins M and D, were identified in the eluate from the B-cell membranes. The histocompatibility-2-complex proteins (H-2D, H-2K and Ia antigens) were also found to be binding sites for LPS on both B-cells and T-cells.

Animals↗

Enhancement and suppression in production of IgM-antibody in mice treated with purified saponins.

Effects of purified saponins on antibody production against SRBC antigen were investigated in adult mice by using the direct hemolytic plaque technique of Cunningham and Szenberg. Intravenous injection of ginsenoside-Rb1, -Rc, senegin-III, -IV or platycodin-D caused increase in antibody-producing cells. However, the same treatment with ophiopogonin-D, ginsenoside-Rd or glycoside-H2 suppressed antibody production. Immuno-suppression due to the latter three substances seemed not to be associated with cytocidal effect. Ophiopogonin-B and platycodin-C had no effects.

Animals↗

Immunohistochemical and ultrastructural analysis of medullary carcinoma of the thyroid in relation to hormone production.

Eighteen cases of medullary carcinoma of the thyroid were analyzed immunohistochemically for calcitonin- and ACTH-containing cells, and tumor cells in 8 cases were examined by an electron microscope and analyzed by manual and computer procedures with particular attention paid to the size and quality of secretory granules. Calcitonin- and ACTH-containing cells were found singly or in clusters in 14 and 11 tumors, respectively. In 4 cases, calcitonin-positive cell clusters and an increase in number of singly scattered C cells were seen apart from the main tumor, suggesting a multicentric nature of certain medullary carcinomas. Some ACTH-containing cells were apparently also positive for calcitonin. In a case of familial Sipple disease, follicular lining cells were replaced in areas with ACTH-containing cells. Three to five frequency distribution curves of the size of secretory granules were obtained in all of 6 cases analyzed, and at least two different types of granule matrix were identified.

Adrenocorticotropic Hormone↗