John A. Colwell

Effect of Diabetic Control on Retinopathy

This paper presents an analysis of the literature regarding the effect of control of diabetes on retinopathy. In diabetics with age of onset before forty years of age and with a duration greater than fifteen years, there is a significantly higher incidence of retinopathy in those judged to have been under poor control than in those with better control. Those patients with poor control had a significantly higher incidence of the more severe forms of diabetic retinopathy. While this association does not necessarily imply a cause and effect relationship, it is not compatible with a point of view which accepts poor control as of little consequence in diabetes.

PERFUSION STUDIES WITH SULFONYLUREAS IN DOGS

These studies were undertaken to determine the site of hypoglycemic action of the available sulfonylureas. In a preliminary report of acute perfusion experiments we suggested a pancreatic site of action. Our results now come from thirty-four experiments in which the compounds and control solutions have been injected at various locations and changes in blood glucose observed. The experiments have been grouped and the data averaged, permitting an improved measure of differences of effect by various injection routes. Statistical validation still is not possible, however, because of the small size of each group.

Primary hyperparathyroidism and salt-wasting nephropathy

Abstract Studies are presented in two male patients with primary hyperparathyroidism who had developed salt-wasting nephropathy in the course of their disease. Both of them had nephrocalcinosis and markedly impaired renal function and exhibited an abnormal decrease in the fraction of filtered sodium reabsorbed by the renal tubules. Both patients showed impaired intestinal absorption and negative balances of calcium and phosphorous and had osteitis fibrosa cystica. Thus salt-wasting nephropathy is an additional and previously undescribed complication of primary hyperparathyroidism.