Richard E. Reitz

Ketoconazole Blocks Adrenal Steroid Synthesis

Ketoconazole, a broad-spectrum, antifungal drug that is administered orally, has been shown to inhibit sterol synthesis in fungi. When gynecomastia developed in some patients taking this drug, we investigated the effects of ketoconazole on steroid synthesis in humans and in isolated adrenal cells from rats. In healthy humans, the cortisol response to adrenocorticotropic hormone was significantly blunted 4 hours after a 400-mg or 600-mg dose. The inhibition persisted for up to 8 hours and was absent by 16 hours. This finding indicated that adrenal androgen response was reduced. Easily achieved therapeutic concentrations of ketoconazole virtually eliminated corticosterone production by isolated adrenal cells from rats. Although ketoconazole at currently used doses has never been documented to cause clinical hypoadrenalism, caution is urged in high- or multiple-dose trials. The drug may prove useful as an agent to block steroid synthesis.

Ischemic Ulcerations of Skin and Necrosis of Muscle in Azotemic Hyperparathyroidism

Abstract Two women, 29 and 36 years old, with hyperparathyroidism due to chronic renal failure had extensive medial calcification and fibrous intimal proliferation of the small arteries of subcutan...

Localization of Parathyroid Adenomas by Selective Venous Catheterization and Radioimmunoassay

Abstract We have successfully applied the radioimmunoassay for parathyroid hormone (PTH) to the localization of parathyroid adenomas by measurements of hormone concentration in multiple blood samples obtained by selective catheterization of the major veins draining the neck and thorax. During venous catheterization, blood samples collected from the left and right jugular, left and right subclavian and left and right innominate veins and superior and inferior vena cava showed a definite localized increase in PTH concentration in six patients. In five patients the increase was found in either the right or the left jugular vein; in the sixth patient a mediastinal location of the adenoma was indicated. The location of the tumor was in agreement with findings at surgery in all patients. The application of these technics can greatly facilitate efforts to remove all abnormal parathyroid tissue at a single operation.

Parathyroid Hormone Secretion in Familial Vitamin-D-Resistant Rickets

Abstract Parathyroid function was determined in four adults and one child with familial vitamin-D-resistant rickets. All subjects demonstrated hypophosphatemia, whereas the total serum calcium and ...

Localization of hyperfunctioning parathyroids: The surgeons' riddle☆☆☆

Abstract Localization of hyperfunctioning parathyroid tumors often poses much difficult for the surgeon. With radioimmunoassay of the PTH of the blood sampled at various levels by selective venous catheterization, it is possible to pinpoint the exact location of the hyperfunctioning parathyroid tumor. The result of a study of seven hyperparathyroid patients is presented. The usefulness and limitations of this technic are discussed.

Role of Free Fatty Acids in Growth Hormone Regulation During Fasting.

Excerpt The effect of nicotinic acid administration (100 mg, intravenously, each 15 min, two doses) on mean plasma levels of free fatty acids (FFA), growth hormone, Cortisol, and glucose was determ...