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Biomedical subjects

S Baba

Publications and source records attributed to S Baba.

At least 1,117 records · Page 62Linked to original sources
PubMed1979

Glucagon secretion during the development of insulin-secreting tumors induced by streptozotocin and nicotinamide.

Serial oral glucose tolerance tests in rats treated with streptozotocin and nicotinamide showed that blood glucose levels after glucose loading were suppressed significantly 7 months after treatment as compared to those of earlier stages. Post-glucose plasma insulin levels were significantly elevated at the 9th to 12th month and concomitantly fasting plasma glucagon levels rose significantly. At that time pancreatic islet cell tumors were demonstrated in all of the rats in this experiment. Post-glucose plasma glucagon levels, however, did not show remarkable changes throughout the observation. In spite of hyperinsulinemia, post-glucose plasma glucagon levels of tumor-bearing rats were significantly lower than those of body weight adjusted controls. It is inferred from the study that secretory activity of pancreatic A-cells of tumor-bearing rats is restrained by excess insulin released from islet cell tumors.

Adenoma, Islet Cell↗
PubMed1979

High concentration of gamma-aminobutyric acid in pancreatic beta cells.

The gamma-aminobutyric acid (GABA) concentration of pancreatic islets in rats treated with streptozotocin (STZ) and of human insulinoma tissue was studied. Seven hours after the administration of 65 mg/kg body weight of STZ, a distinct increase in serum insulin concentration and at the same time a decrease in blood glucose level were seen. Twenty-four hours after the injection of STZ, however, the level of serum insulin decreased much, whereas that of blood glucose increased considerably. On the other hand, the GABA concentration of the islet was reduced dramatically to about one-tenth the control level after both 7 and 24 h. The histologic investigations of the islets revealed the destruction of B cells but no changes in A and D cells 7 and 24 h after the treatment of STZ. Nerve fibers and nerve endings in the islets were preserved intact all through the study. The GABA and insulin contents of the two cases of human insulinoma were determined. One insulinoma, which was compactly occupied with B cells according to its histologic features, contained a high concentration of GABA. The other tumor, having a rather sparse distribution of B cells in it as compared with the former case, possessed a lower concentration of GABA, but it was still high compared with that of its surrounding tissues. The present observations indicate that a large amount of GABA is available in the B cells of the pancreatic islets.

Adenoma, Islet Cell↗
PubMed1979

Studies on the biotransformation of paeonol by means of isotope tracer techniques.--Synthesis and physicochemical properties of carbon-13 and deuterium labeled compounds--.

In order to perform the metabolic study of paeonol (I) in human and animals by using isotope tracer techniques, synthesis of I and its urinary metabolites labeled with carbon-13 or deuterium was investigated. 2-Hydroxy-4-methoxy[d3]acetophenone, 2,5-dihydroxy-4-methoxy[d3]acetophenone, and resacetophenone[acetyl-13C2] were synthesized from methyl iodide-d3, dimethyl sulfate-d6, and acetic acid-1,2-13C2, respectively. Physicochemical studies by IR and NMR spectra showed that stable isotope was not eliminated during the synthetic process of each compound. For the quantification of the metabolites by GC-MS analysis, isotope effect on gas chromatography and fragmentation was studied.

Acetophenones↗
PubMed1979

Evaluation of a commercial enzyme immunoassay for insulin in human serum, and its clinical application.

We applied a "sandwich" method, with use of beads coated with anti-insulin serum and of peroxidase-labeled anti-insulin serum, to an enzyme immunoassay of insulin in human serum. 5-Aminosalicylic acid was used as the substrate for the enzymic reaction. As little as 5 milli-int. units of insulin per liter of serum insulin was detectable. Reproducibility was satisfactory, but extraordinarily high concentrations of proinsulin and of hydrogen donors such as reduced glutathione affect results of the assay. Values determined by our enzyme immunoassay and by double-antibody radioimmunoassay correlated highly (r = 0.938, p less than 0.001, n = 216). We recommend this method for use in the clinical laboratory.

C-Peptide↗
PubMed1979

Gonadal function after renal allotransplantation.

Our data suggest that impaired testicular function was corrected, but not completely, by renal allotransplantation. One patient with impaired renal function showed azoospermia and six patients with normal renal function oligospermia. It was observed that conception might occur when the sperm count was below 10 million/ml. The elevated FSH among patients with azoospermia or oligospermia indicates a responsive pituitary. The positive clomiphene test suggests that the function of the hypothalamo-hypophysial axis is normal.

Adult↗