David M. Kessner

Physiologic studies in renal osteodystrophy treated by subtotal parathyroidectomy.

Abstract Two patients with advanced renal insufficiency and osteitis fibrosa cystica were found to have severe renal salt-wasting and hypercalciuria. Medullary cysts were demonstrated at postmortem in one case and suspected in the other. The level of parathyroid hormone in plasma was greatly elevated. Both patients were treated with subtotal parathyroidectomy for renal osteodystrophy. In each there was clinical and roentgenologic evidence of bone healing and decreased metastatic calcification. There was a slow decrease in the circulating levels of parathyroid hormone after parathyroid tissue was removed. In one patient the level returned to normal, in the other it fell to one tenth of the preoperative level. Renal tubular reabsorption of phosphate was extremely low and was unaffected by subtotal parathyroidectomy, suggesting that parathyroid hormone was not the primary factor responsible for the abnormal renal handling of phosphate in these uremic patients.

Effect of magnesium deficiency on gastrointestinal transfer of calcium.

Summary Experimental magnesium deficiency in rats is associated with an increased ability of the isolated everted intestine to transfer calcium against a concentration gradient. The augmented calcium accumulation of magnesium deficiency is not altered by replacement of magnesium in the bath. Although a direct effect of magnesium depletion on cellular transport mechanisms is not ruled out, the results are consistent with a humoral influence, like that of parathyroid hormone, on the gut in magnesium deficiency. The authors gratefully acknowledge the technical assistance of Mrs. Lorraine Pozika.

Effects of Mg deficiency and parathyroidectomy on gastrointestinal Ca transport in the rat.

An open-ended, everted gut-sac technique was used to measure in vitro duodenal transfer of calcium in magnesium-deficient and pair-fed control animals with and without parathyroid glands. In contrast to previous studies employing the closed gut-sac technique in calcium-deprived animals, we were unable to demonstrate an effect of parathyroidectomy on the in vitro transport of calcium across the duodenum. Magnesium deficiency resulted in enhanced intestinal transport of calcium. These data confirm our previous studies and demonstrate that this effect of magnesium deficiency is linear over 2 hr of incubation. This enhancing effect of magnesium deficiency on gastrointestinal calcium transport was blocked by parathyroidectomy. The results of this study are consistent with the hypothesis that magnesium deficiency increases calcium transfer of the isolated everted gut-sac of rats by stimulating the secretion of parathyroid hormone.

Mortality trends for chronic nephritis and infections of the kidney: A clinical and statistical comparison between mortality in New Haven, Connecticut and the United States, 1950–1960☆

Abstract The hypothesis is tested that, for the United States, in the absence of changes in diagnostic criteria, the combined death rates for chronic nephritis and infections of the kidney between 1950 and 1960 should have remained constant. The study population consisted of all residents of New Haven, Connecticut who died in New Haven during the triennia 1949–1951 and 1959–1961 from the underlying causes of chronic nephritis and infections of the kidney (ISC 592–594, 600) ( N = 99). All available clinical and autopsy records from the two major New Haven hospitals were abstracted. No significant change between the triennia was observed in diagnostic practice or in mortality even though in the United States as a whole mortality from these conditions have shown a marked decline. The data support the hypothesis that the decline in the combined rates between 1950 and 1960 in the U.S. was due primarily to alteration in diagnostic habits.