The in vitro effect of a thymic polypeptidic extract on the function of T-cells and macrophages.

: A thymic polypeptidic extract with a molecular weight of under 10,000 daltons was used in in vitro experiments to test its effect on the E-rosetting reaction of the T-total and T-helper lymphocytes from the peripheral blood of patients with thyroid cancer, Cushing's syndrome and others, as well as from healthy persons. The effect of the extract on peritoneal macrophages phagocytosis from both irradiated and normal rats was also tested in vitro. It was found that in healthy persons the E-total rosettes count did not change under the influence of the thymic extract, whereas the E-helper rosettes count increased up to 21% in 4 of the 10 subjects. In thyroid cancer, Cushing's disease, and operated Graves' disease, the thymic extract induced a up to 23% increase in E-total rosettes count in 8 of 11 cases and an increase of up to 90% in the E-helper rosettes count in 9 of 12 cases. The thymic extract had no effect on the rat peritoneal macrophages phagocytosis in vitro.