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V DiStefano

Publications and source records attributed to V DiStefano.

5 recordsLinked to original sources
PubMed1979

Control of phenylethanolamine N-methyltransferase by glucocorticoids in cultured bovine adrenal medullary cells.

A procedure for the disaggregation of bovine adrenal medullary cells and a system for their maintenance in primary culture is described. The effect of glucocorticoids on the epinephrine-synthesizing enzyme, phenylethanolamine N-methyltransferase (PNMT), was examined. The initial level of PNMT activity in cultured cells was maintained by cortisol for 5 days. PNMT activity in untreated cultures declined steadily. After 5 days in culture the response of PNMT activity to cortisol was lost. The EC50 for maintenance of PNMT activity was about 15 ng/ml or 4 x 10(-8) M cortisol. Steroid structural and stereochemical requirements were similar to other glucocorticoid responses. Changes in the functional group or steric configuration of position 11 of cortisol abolished activity. Progesterone inhibited the maintenance of PNMT activity by cortisol in a competitive fashion. It was concluded that the response of PNMT activity to glucocorticoids is specific and sensitive, with strict structural and stereochemical requirements.

Adrenal Medulla↗
PubMed1979

Serratus anterior paralysis in the young athlete.

Ten cases of isolated, complete paralysis of the serratus anterior muscle were diagnosed in young athletes during a three-year period. One patient had recurrent partial paralysis of the serratus anterior muscle, the first such case reported. From studies on cadavera and clinical observations, we concluded that paralysis of the serratus anterior muscle results from a traction injury to the long thoracic nerve of Bell. Since full recovery usually occurs in an average of nine months, surgical methods of treatment should be reserved for patients in whom function fails to return after a two-year period. Non-strenuous use of the involved extremity with avoidance of the precipitating activity, followed by exercises designed to maintain the range of motion of the shoulder and to increase the strength of associated muscles, is advocated for treatment of acute or repetitive injuries to the long thoracic nerve of Bell.

Adult↗