Stromal-vascular cells obtained from adult human subcutaneous adipose tissue were cultured in a chemically defined serum-free medium. In the presence of 0.2 nM triiodothyronine and 0.5 gM insulin, up to 25% of the cells were able to undergo terminal adipose differentiation within 18 d, as assessed by lipid accumulation and the expression of lipoprotein lipase (LPL) and glycerol-3-phosphate dehydrogenase (GPDH) activities. Addition of cortisol resulted in a potent dose-dependent stimulation of the adipose differentiation process. Cortisol could be replaced by dexamethasone and partly by aldosterone, but not by sex steroids. The proportion of differentiated cells was dependent upon the age of the donor; when isolated from young adults, up to 70% of the stromal-vascular cells expressed the adipocyte phenotype as compared with 5-10% when the cells were isolated from the oldest subjects. An inverse relationship was observed between the age of the 27 normal-weight donors and the extent of GPDH expression after maintenance of the cells for 18 d in chemically defined medium supplemented with insulin, triiodothyronine, and cortisol (r = -0.787, P < 0.001). It is concluded that adult human adipose tissue still contains precursor cells that are able to undergo adipose differentiation in vitro. This improved culture system may offer the opportunity to characterize other adipogenic factors as well as antiadipogenic factors involved in the control of adipose tissue growth.

To study the in vitro differentiation of human adipocyte precursor cells and its regulation by hormones, primary cultures of stromal vascular cells of human adipose tissue were established. A 30- to 70-fold increase in the number of developing fat cells was achieved by the addition of cortisol or related corticosteroids in the presence of insulin. Either of the two hormones alone was ineffective. The stimulatory action of cortisol was dose dependent and occurred at physiological concentrations. The results suggest that glucocorticoids may play a role in the development of human hyperplastic obesity by stimulating the formation of adipocytes from precursor cells.

Continuous contral of blood sugar in diabetics without dietary restriction has been effected by a Glucose Controlled Insulin Infusion System (GCnS) consisting of an automatie blood glucose determination apparatus, a dedicated microcomputer, allowing the optimal adaptation of the diabetie to the artificial endoerine pancreas, a special insulin pump and an automatie printer. Insulin-dependent juvenile diabetics and diabetic subjeets suffering from diabetic coma and ketoacidosis were successfully controlled and corrected for various periods of time, exhibiting eompletely normal blood glucose values despite unrestricted food intake. Future developments are seen on the one band in the further improvement of the present apparatus for complete automatic treatment of acute diabetic conditions, e.g. diabetic coma, pre-and post-

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Somatostatin, a recently synthesized hypothalamic growth hormone release-inhibiting factor (GIF), was used in the cyclic and linear form. In all subjects studied, the cyclic GIF inhibited gastrin secretion during basal conditions as well as during a standard food stimulus, with immediate rebound after the infusion was stopped. Similar responses were observed in a hypophysectomized patient, indicating that this effect of GIF was independent of suppression of growth hormone secretion. Cyclic and linear GIF, when administered in normal subjects during an infusion of synthetic human gastrin I, almost totally suppressed gastric secretion. The results indicate that GIF is a potent inhibitor of gastric secretion and gastrin release.