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Biomedical subjects

A Shibata

Publications and source records attributed to A Shibata.

At least 739 records · Page 41Linked to original sources

Case report: computed tomography of "Page" kidney.

The radiologic features and computed tomography (CT) findings in a case of "Page" kidney are described. Initial CT scans revealed a large mass in the left renal bed. A repeat CT study using contrast medium showed the mass to be a centrally enhanced renal tissue with surrounding avascular zone. CT gave the most useful diagnostic information of the radiologic examinations performed.

Adult↗

[The effect of calcium on steroidogenesis in isolated human adrenal cells (author's transl)].

The present experiment was planned to verify the effect of calcium on adenyl cyclase in isolated human adrenal cells. Normal adrenal glands were obtained surgically from patients with primary aldosteronism and advanced breast cancer. Isolated adrenal cells were prepared by the modified Haning's method. They were incubated at 37C under a gas mixture of 95 percent O2: 5 percent CO2 in calcium-free Krebs-Ringer bicarbonate buffer solution containing 0.2 percent glucose and 0.5 percent fatty acid-free bovine serum albumin, to which various doses of CaCl2 or ACTH were added. Thirty minutes later, cyclic-AMP was measured by cyclic-AMP assay kit (The Radio-chemical Center, Amersham). 11-OHCS was estimated fluorometrically by the modified Silber's method after incubation for 2 hours. In the calcium-free incubation medium, productions of 11-OHCS and cyclic-AMP were negligible. In the concentration of 2.54 mM/L of calcium, 11-OHCS production increased with significant difference statistically, while the increase of cyclic-AMP production was not significant. In the concentration of 12.70 mM/L of calcium, however, cyclic-AMP production increased remarkably. When ACTH was added to the incubation medium containing 2.54 mM/L of calcium, productions of 11-OHCS and cyclic-AMP also increased remarkably. These results indicate that adenyl cyclase of human adrenocortical cells is directly stimulated by calcium and suggest that calcium acts as the second messenger of ACTH.

11-Hydroxycorticosteroids↗

Standardization fo a digestion-filtration method for isolation of pancreatic islets.

Standardization of a technic for isolating large numbers of pancreatic islets is described. This procedure employed collagenase digestion of rat pancreatic tissue in a cylindrical wire screen in order to separate isolated islets from undigested pancreas. From this basic protocol the following conditions were established: (1) the duration of the initial digestion period was found to be optimal at six minutes; (2) three subsequent digestions of one minute each effected maximum islet yield; (3) the optimal initial collagenase concentration was found to be 1,000 U. (Worthington)/ml.; and (4) proper reductions of collagenase concentrations during the three subsequent digestions were found to be 50 per cent of each preceding incubation period. This method, combined with Ficoll gradient separation, yielded a mean of 800 islets per two rat pancreases. The isolated islets appeared morphologically intact, contained 0.36 +/- 0.05 mug. protein/islet, and demonstrated a normal biphasic release of insulin in response to stimulative levels of D-glucose. The present method provides a means for obtaining a large mass of viable islet cell tissue in a short time.

Animals↗