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Biomedical subjects

S Shapiro

Publications and source records attributed to S Shapiro.

At least 577 records · Page 32Linked to original sources
PubMed1975

Regulation of in vitro insulin release from a transplantable Syrian hamster insulinoma.

An insulin-producing islet cell tumor of the Syrian hamster has been studied in vitro for its capacity to respond to known stimuli of insulin release. Insulin secretion during short term incubation and perifusion of fragments of tumor was detected by radioimmunoassay. Insulin release was increased 2-4 fold by 40 mM potassium in the presence of calcium, glucose (22 mM), glucagon (0.3-3.0 muM), N6,02'-dibutyryl adenosine 3',5'-monophosphate (cAMP; 6mM), and theophylline (10 mM). Concentrations of glucagon that induced insulin release were also effective in activating adenylate cyclase in the membranes of tumor cells. Thus, this tumor appears to possess a cAMP-mediated mechanism for insulin release. Somatostatin (0.8-25 mum) inhibited glucagon-induced insulin release without altering basal or glucagon stimulated adenylate cyclase activity. It would appear that inhibition of glucagon induced insulin release by somatostatin is not mediated by adenylate cyclase. We propose that insulin release by this tumor is sufficiently similar to that found in normal islets so as to make it a suitable model for biochemical studies that require large quantities of homogeneous tissue.

Adenoma, Islet Cell↗
PubMed1975

Ventricular premature beats and mortality of men with coronary heart disease.

Frequency and qualitative characteristics of ventricular premature beats (VPB) are determined from 1 hour of electrocardiogram (ECG) monitoring of men with coronary heart disease in a continuing study among members of the Health Insurance Plan of Greater New York. Mortality among 924 such men during an average observation period of 10 months was higher among men with VPB than among those free of VPB. In comparison with the routine 12-lead ECG, the hour of ECG monitoring increased the proportion of men identified as showing ectopic activity from 15% to 52%. Only half of men with 10 or more VPB in the hour of monitoring were noted as having VPB on the routine ECG; mortality among these men was relatively high whether or not VPB appeared on the short sample ECG.

Adult↗