Potassium-wasting nephropathy secondary to chemotherapy simulating Bartter's syndrome.

A patient with a potassium wasting nephropathy secondary to chemotherapy simulating Bartter's syndrome is described. A 64-year-old woman with diffuse histiocytic lymphoma developed persistent hypokalemia following a course of Cytoxan (cyclophosphamide), Adriamycin (doxorubicin), vincristine, and prednisone (CHOP)-Bleo. The diagnosis of a functional Bartter's syndrome was concluded following evaluation of serial plasma renins, aldosterone levels, and urinary electrolytes. Evidence is suggestive that a subpopulation of patients receiving chemotherapy may develop a functional Bartter's syndrome, and it is important to consider this diagnosis in patients who develop hypokalemia subsequent to chemotherapy introduction.

Water-soluble specific growth hormone binding sites from cultured human lymphocytes: preparation and partial characterization.

Cultured human lymphocytes (IM-9 cell line) have specific binding sites or receptors for human growth hormone (hGH). Under appropriate conditions, this specific binding material is spontaneously released into the incubation medium and is solubilized without the use of detergents. This water-soluble preparation binds [125I]iodo-hGH with the same specifictiy as receptors on the intact cell. Unlabeled hGH, but not porcine growth hormone or insulin, competes with labeled hGH for binding to the soluble preparation. Growth hormone preparations of varying purity compete for binding to the soluble binding preparation in the same rank order as they compete for binding to the intact IM-9 lymphocyte. [125I]iodo-hGH incubated with, but not bound to, the soluble preparation is partially degraded, while the [125I]iodo-hGH that is bound to the soluble preparation is protected from degradation, and its ability to rebind to fresh cells is enhanced. The [125I]iodo-hGH-soluble binding preparation complex can be dissociated by the addition of large quantities of unlabeled hGH or by lowering the pH, and [125I]iodo-hGH in both instances remains intact and undegraded. The soluble binding preparation did not sediment when centrifuged at 200,000 X g for 4 hours and was not retained on 0.20 micron Millipore filters. The soluble binding preparation was not retarded on Sephadex G-200. Binding activity was abolished by tryptic digestion. These studies demonstrate that hGH-binding sites, like previously reported insulin binding sites, can be spontaneously solubilized from cultured human lymphocytes, without the use of detergents; these soluble binding preparations are of high molecular weight and are, at least in part, protein in nature.

Response to LH-RH and clomiphene citrate in two women with the Prader-Labhart-Willi syndrome.

Two women with the Prader-Labhart-Willi syndrome are presented. The gonadotropin response to LH-RH administration was studied prior to, immediately following, and 6 months after a 6-week trial of clomiphene citrate, 200 mg per day for 21 days in divided doses, followed by 100 mg for 21 days in divided doses, followed by 100 mg per day for 14 days in divided doses, and followed by 50 mg per day in a single dose for an additional 14 days. During therapy, the basal gonadotropin and estradiol concentrations rose from prepubertal levels to those of mature women in midmenstrual cycle. However, 6 months after cessation of treatment, the basal gondadotropin and estradiol levels had returned to the prepubertal range. The initial response to LH-RH in the 2 patients differed in that one was clearly prepubertal and the other indistinguishable from the broad range of the adult normal response. The LY and FSH responses to LH-RH administration was greater after 6 weeks of clomiphene citrate therapy than they were either before (both patients) or 6 months after treatment (1 patient). We conclude that there is heterogeneity in the response to LH-RH administration in the Prader-Labhart-Willi Syndrome, just as there is in other syndromes of hypogonadotropic hypogonadism. A normal adult response of gonadotropins to the administration of LH-RH was acheived during clomiphene citrate therapy.

Pituitary stones.

Two cases of patients having calcification within the sella turcica (pituitary stones) have been studied and followed up, one patient for 18 years. A detailed analysis of the radiographic findings and endocrinologic profiles of these two patients is presented. The rarity of bona fide pituitary stones and their benign nature, as evidenced by the two cases reported here, are emphasized.

Low renin hypertension.

Low renin hypertension comprises a spectrum of disorders ranging from primary aldosteronism to obvious disorders of other mineralocorticoids, as well as a variety of miscellaneous disorders. The largest group of patients with low renin hypertension have no clear abnormality in mineralocorticoid production. However, many lines of evidence suggest the critical role of volume excess in the pathogenesis of hypertension in these patients. More detailed physiological studies must be performed in order to totally understand the spectrum of pathophysiology in low renin hypertension. However, while such studies are in progress the evidence from the literature suggests that these patients must be treated and that in most of these patients diuretic administration, either spironolactone or the thiazide group of diuretics, is usually effective in achieving a reduction of blood pressure to normal.