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Biomedical subjects

S Oikawa

Publications and source records attributed to S Oikawa.

At least 271 records · Page 15Linked to original sources

Effect of methylprednisolone and "pulse" therapy with methylprednisolone sodium succinate on autologous immune complex nephritis in rats.

Autologous immune complex (AIC) nephritis was induced in rats with a single foot-pad injection of renal tubular epithelial antigen suspended in complete Freund's adjuvant. It was suggested by gel filtration of serum on Sephadex G-200 column that increase in the concentration of macroglobulins was the first alteration reflected on the serum proteins after immunization; the concentration of macroglobulins increased while the concentrations of albumin and gamma-globulin still remained in the normal range. The effect of 6 alpha-methylprednisolone sodium succinate (MP-S), 6 alpha-methylprednisolone (MP) and cyclophosphamide on the AIC nephritis in rats was studied. "Pulse" therapy, that is, an intraperitoneal administration of a large dose (26.5 mg/kg) of MP-S for 3 successive days a week and followed by an intermission for 4 days a week was started from the week of immunization with renal tubular epithelial antigen and continued for 8 weeks, resulting in the retardation of the AIC nephritis induction associated with a partial suppression of the development of proteinuria. Treatment with MP (4 mg/kg) or cyclophosphamide (10 mg/kg) every other day from the week of immunization for 8 weeks partially retarded or completely suppressed the AIC nephritis induction, respectively. On the other hand, the MP-S "pulse" therapy and the MP treatment of rats suffering from the already established AIC nephritis resulted in no apparent improvement of the disease.

Animals↗

Abnormal response of pancreatic glucagon to glycemic changes in diabetes mellitus.

In order to determine pancreatic alpha cell function in diabetes mellitus, plasma glucagon responses to either an oral glucose load or insulin-induced hypoglycemia were investigated. Plasma glucagon in 6 normal control subjects fell significantly after the administration of glucose, whereas the levels of plasma glucagon did not decrease after glucose ingestion in patients with diabetes mellitus. In the group with severe diabetes, whose fasting blood glucose exceeded 200 mg/100 ml, the plasma glucagon level rose after glucose administration instead of decreasing. In 6 patients with diabetes mellitus, plasma glucagon did not decrease but rather increased during a glucose tolerance test which was performed after treatment with insulin and/or diet. In 6 control subjects, there was a remarkable rise of plasma glucagon in response to insulin-induced hypoglycemia. In contrast, no significant rise in plasma glucagon was demonstrated in 19 diabetic subjects undergoing intravenous insulin test. Seven patients, in whom an insulin test was repeated after treatment with insulin, sulfonylurea, or diet had a small rise in peak plasma glucagon and an increase in the integrated area under the glucagon response curve. It is concluded that the abnormal glucagon response to changes in blood glucose might be a primary defect in diabetes mellitus.

Adult↗

Interactions of obesity and glucose-stimulated insulin secretion in familial hypertriglyceridemia.

Plasma lipids and lipoproteins, glucose tolerance, plasma insulin response to glucose load, and liver function were examined in 81 relatives of 12 index cases with primary endogenous hypertriglyceridemia, hyperinsulinemia, and hepatic steatosis, as well as in 90 nonrelatives, including the spouses, as controls. Insulin hypersecretion (with or without glucose intolerance), endogenous hypertriglyceridemia, and abnormal liver function suggesting hepatic steatosis were shown to exist in the relatives mostly in combined fashion. Correlation analysis and stepwise multiple regression analysis revealed that the combined disorder developed on the basis of obesity. The incidence of diabetes mellitus was significantly high in the relatives (14.8 per cent) as compared with the normal Japanese population (3.5 per cent). Although the vertical transmission of the combined disorder was noted in almost all pedigrees, the frequency distribution analysis of insulin response, glucose tolerance, and plasma triglyceride showed the histograms of these variables similarly skewed to the right as compared with those of the controls, with no apparent bimodality. In view of the hitherto suggested role of insulin in triglyceride metabolism, it is concluded that hyperinsulinemia coupled with obesity seems to be the basic trait of this form of familial hypertriglyceridemia and hepatic steatosis, though the mode of transmission remains to be elucidated.

Adolescent↗

Purification and properties of two acid phosphatases from midgut glands of abalone Haliotis discus.

Midgut glands of abalone Haliotis discus contained two acid phosphatases [orthophosphoric-monoester phosphohydrolase (acid optimum), EC 3.1.3.2] separable by phosphocellulose column chromatography. They were designated as acid phosphatases I and II in order of elution and were purified 99- and 290-fold, respectively. Purified acid phosphatase II was nearly homogeneous as judged by polyacrylamide gel electrophoresis. The substrate specificity of acid phosphatase I was narrow, whereas that of acid phosphatase II was broad. Good substrates for acid phosphatase I included p-nitrophenyl phosphate, phosphoenolpyruvate, inorganic pyrophosphate, and nucleoside di- and triphosphates. The acid phosphatases did not require any metal ion for maximum activity and were inhibited by Zn2+, Cu2+ and Hg2+. Fluoride and arsenate were potent inhibitors of both enzymes. The pH optima of acid phosphatases I and II were 5.9 and 5.5, respectively. The molecular weights of acid phosphatases I and II were estimated to be 28,000 and 100,000, respectively, by gel filtration on Sephadex G-100. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis suggested that acid phosphatase II consists of two identical subunits.

Acid Phosphatase↗

Detection of serum haptoglobin by enzyme-linked immunosorbent assay in cows with fatty liver.

Haptoglobin cannot be detected in the serum of healthy cattle by the haemoglobin-binding assay or single radial immunodiffusion. The present study was designed to examine whether an enzyme-linked immunosorbent assay could be applied to measure serum haptoglobin concentrations in healthy cows and in cows with fatty liver. When either purified cow haptoglobin or haptoglobin-positive serum were used as the antigen in the assay, the standard curves obtained were distinctly different, and haptoglobin in serum was detected more sensitively than the purified protein. The addition of bovine serum albumin to purified haptoglobin shifted the curve towards that obtained with haptoglobin-positive serum, suggesting that an interaction with serum albumin was partly responsible for the different standard curves. By use of the standard curve for haptoglobin in serum, the mean (SEM) concentration of haptoglobin in samples from four cows with fatty liver was 466 (147) micrograms ml-1, but the sera from four apparently healthy cows contained less than 0.01 microgram ml-1 haptoglobin.

Animals↗

Cloning and sequence analysis of cDNA encoding a precursor for human atrial natriuretic polypeptide.

Recent identification of natriuretic-diuretic activity in peptides isolated from human and rat atrial tissue implicates them in the control of extracellular fluid volume and electrolytic homeostasis. The presence of multiple forms of the peptides ranging from 3,000 to 13,000 molecular weight (MW) suggests they may all derive from the same precursor. The established amino acid sequence of alpha-human atrial natriuretic polypeptide (alpha- hANP ), a 28-residue peptide with potent natriuretic activity, provided the means to elucidate the structure of the precursor for alpha- hANP and the gene encoding it. Here we report the cloning and sequence analysis of the cDNA of human atrial mRNA encoding a precursor of alpha- hANP . The cDNA encodes gamma-human atrial natriuretic polypeptide (gamma- hANP ) of 13,000 MW, whose C-terminal 28 amino acid residues may be processed as alpha- hANP .

Amino Acid Sequence↗