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H E Harrison

Publications and source records attributed to H E Harrison.

At least 37 records · Page 2Linked to original sources

Recent advances in calcium metabolism. I. Mechanisms of calcium homeostasis.

Within recent years newly acquired knowledge has provided a clearer understanding of some aspects of the complex mechanisms that collectively maintain calcium homeostasis within body fluids and it is our intent to define current concepts of the interrelationship of these various factors to the end that fuller understanding may be available concerning the maintenance of calcuim homeostasis in health as well as features which result in its disruption and the consequent effects of imbalances of calcium in various disease states. In this first section dealing with the physiologic state, there are included descriptions of: (1) the metabolism of vitamin D, the synthesis of its active metabolites, 25 OHD3 and1.25(OH)2D3, and the metabolic actions of the active vitamin D metabolite and analogues upon gastrointestinal, bone, and kidney functions; (2) the synthesis, secretion, and metabolic activity of parathyroid hormone and the difficulties with the radioimmunoassay of PTH related to the number of PTH-like peptides in the circulation; and (3) the chemistry, metabolism, and biologic activities of calcitonin, a hypocalcemic principle derived from the parafollicular cells of the thyroid gland. It is emphasized that under normal circumstances these humoral mechanisms act in an integrated manner to maintain serum concentrations of total and ionized calcium within narrowly defined limits.

Adolescent↗

Recent advances in calcium metabolism. II. Disorders of calcium homeostasis.

Abnormalities of calcium and mineral metabolism are described in relation to the differential diagnosis, clinical characteristics, diagnostic procedures, and treatment of infants and children with hypocalcemia, hypercalcemia, rickets, chronic renal insufficiency, and other disorders of calcium metabolism. Understanding of the basic pathogenesis of each abnormality of calcium homeostasis is essential for the rational management of affected patients.

Adolescent↗

Rickets.

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Animals↗

Fanconi syndrome following bowel surgery and hepatitis reversed by 25-hydroxycholecalciferol.

A permature male infant required intravenous alimentation for six weeks following extensive surgery for ileal and cecal necrosis. At 3 months he developed evidence of hepatitis. Subsequently osteoporosis and the Fanconi syndrome appeared. Urine phosphate clearance was 83 percent of creatinine clearance at a serum phosphate concentration of 1.6 mg/dl. Concentration of plasma immunoreactive parathyroid hormone was elevated at 550 pg/ml. 25-Hydroxycholecalciferol was given at 240 mug/day. Aminoaciduria disappeared and bone healing occurred. Serum phosphate rose to 6.5 mg/dl and phosphate clearance fell to 2 percent of creatinine clearance. Upon cessation of 25-OHCC therapy, the Fanconi syndrome recurred despite administration of vitamin D2. 25-OHCC was then administered at 40 mug/day, and the urine abnormalities were reversed. The patient probably developed hyperparathyroidism, secondary malabsorption, and hepatitis. The Fanconi syndrome was the consequence of the hyperparathyroidism. 25-OHCC therapy was more effective than vitamin D in reversing the disordered state, possibly because of impaired hepatic metabolism of vitamin D2.

Cecal Diseases↗

Calcium.

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Amino Acids↗

Dihydrotachysterol: a calcium active steroid not dependent upon kidney metabolism.

The activity of dihydrotachysterol and cholecalciferol was determined in nephrectomized or sham-operated vitamin D-depleted rats using in vitro transport of calcium and phosphate by everted intestinal preparations as the index of physiologic response. The activity of dihydrotachysterol was not reduced by absence of the kidneys whereas that of cholecalciferol was markedly inhibited so that at least a 10-fold greater dose of the latter was necessary to produce an equivalent effect in the nephrectomized rat as in the control. Dihydrotachysterol is therefore equipotent with cholecalciferol in the anephric rat although much less active in the intact animal.

Animals↗