Biomedical subjects
Publications and source records attributed to U S Barzel.
Most hyperparathyroidism is subclinical, with no complaints of bone pain, constipation, mental confusion, or depression, no skeletal findings on x-ray, and no history of kidney stones. Routine hyperparathyroidectomy for asymptomatic hypercalcemia, with normal bone density and normal calciuria, particularly with moderate elevations of serum calcium, is now generally rejected.
Despite its earlier reputation as a relentlessly progressive disease, hyperparathyroidism may actually remain asymptomatic for many year. If its possible presence is signaled by hypercalcemia and supported by other laboratory findings, surgery is often indicated because no medical treatment is effective, and long-term follow-up of this frequently malignant condition is difficult; the surgical cure rate is about 95%.
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Described here is a patient with esophageal carcinoma who had hypercalcemia, an elevated serum level of parathyroid hormone and normal parathyroid glands. A review of the literature reveals that a total of 25 other patients with ectopic hyperparathyroidism in esophageal malignancy have been described, four of whom had documented elevations of serum parathyroid hormone levels. Esophageal neoplasms should be added to the list of tumors associated with ectopic secretion of parathyroid hormone.
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The purpose of this study was to examine the effect of ammonium chloride ingestion on the hypercalcemic effect of parathyroid hormone in vivo. Thyroparathyroidectomized rats were given 1.5% ammonium chloride for 5-6 days. Ingestion of ammonium chloride increased serum calcium, but also significantly enhanced the calcium elevating effect of injected parathyroid extract. This result is compatible with a proposed hypothesis that the calcium mobilizing function of the parathyroid hormone may be enhanced by the hormone's own influence on systemic hydrogen ion concentration.
Adult female rats were subjected to a prolonged period of observation after oophorectomy. The oophorectomized animals and their controls were given a regular diet ad lib and water or ammonium chloride as their drinking fluid. Oophorectomy did not result in reduced bone density, fat free weight, total ash weight, or calcium content of the bone, thus failing to produce the changes of osteoporosis. Ammonium chloride ingestion caused significant decreases in the same parameters equally in normal and oophorectomized rats. Thus, oophorectomy neither leads to changes of osteoporosis, nor increases the sensitivity of the bone to ammonium chloride-induced osteoporosis.