Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0020437 (hypercalcemia)
 10,293 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Mean plasma 1(alpha),25-dihydroxyvitamin D[1(alpha),25(OH)(2)D] was significantly increased and serum parathyroid hormone was suppressed in three patients with sarcoidosis and hypercalcemia. Prednisone lowered the mean plasma 1(alpha),25(OH)(2)D to normal range and corrected the hypercalcemia. To elucidate the mechanism for the increased sensitivity to vitamin D in this disorder, the effects of orally-administered vitamin D(2) were determined in seven normal subjects, four patients with sarcoidosis and normal calcium metabolism and three patients with sarcoidosis and a history of hypercalcemia who were normocalcemic when studied. Serum and urinary calcium, serum 25-hydroxyvitamin D (25-OHD), plasma 1(alpha),25(OH)(2)D and, in some studies, calcium balance were measured. Vitamin D(2), 250 mug a day for 12 d, produced little, if any, change in mean plasma 1(alpha),25(OH)(2)D and in urinary calcium in the normals and in the patients with normal calcium metabolism. In contrast, vitamin D(2) produced increases in plasma 1(alpha),25(OH)(2)D from concentrations which were within the normal range (20-55 pg/ml) to abnormal values and increased urinary calcium in two patients with abnormal calcium metabolism. In an abbreviated study in the third patient, vitamin D(2), 250 mug a day for 4 d, also increased plasma 1(alpha),25(OH)(2)D abnormally from a normal value. There was a highly significant correlation between plasma 1(alpha),25(OH)(2)D and urinary calcium. Serum 25-OHD and serum calcium remained within the normal range in all subjects and patients. These findings provide evidence that the defect in calcium metabolism in sarcoidosis probably results from impaired regulation of the production and(or) degradation of 1(alpha),25(OH)(2)D. Prednisone may act to correct the abnormal calcium metabolism by reducing circulating 1(alpha),25(OH)(2)D.
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PMID:Evidence that increased circulating 1 alpha, 25-dihydroxyvitamin D is the probable cause for abnormal calcium metabolism in sarcoidosis. 31 11

1 Agents known to delay absorption from a subcutaneous site were tested in chicks for their ability to prolong the hypercalcaemic response to parathyroid hormone (PTH). 2 Polyvinylpyrrolidone was found to enhance the response but gelatine greatly reduced the 2 h hypercalcaemia. 3 The reduction by gelatine was reversed when the protease inhibitor aprotinin was added to the injection vehicle, and hypercalcaemia then persisted for more than 8 h. 4 Of other protease inhibitors studied, epsilon-aminocaproic acid was also found to enhance the hypercalcaemic response to subcutaneous PTH and its fragments but, unlike aprotinin, it was ineffective in the presence of gelatine. 5 By radioimmunoassay and bioassay respectively, it was confirmed that aprotinin raised circulating levels of PTH and also of another peptide hormone, calcitonin, injected subcutaneously. 6 Addition of calcium to the solutions injected subcutaneously abolished the hypercalcaemic response to PTH while injection of calcium and PTH simultaneously but at separate sites left the response unaltered. 7 The two protease inhibitors, epsilon-aminocaproic acid and aprotinin, each restored the response to subcutaneous PTH despite the presence of calcium at the injection site. 8 It was concluded that protease inhibitors injected subcutaneously with PTH and calcitonin in the chick reduced the rate of degradation of these hormones and that the proteases responsible for hormone degradation at the subcutaneous injection site may be released or activated by calcium ions.
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PMID:Evidence that protease inhibitors reduce the degradation of parathyroid hormone and calcitonin injected subcutaneously. 31 28

Long term hypercalcaemia was induced in F. pennanti by alternate day intramuscular injections of 50,000 IU of vitamin D2 and by giving them 1% CaCl2 solution prepared in tap water to drink. The controls were not injected with vitamin D2 and were given tap water. The serum calcium levels at various stages of the experiment (1-29 days) show increased values as compared with those of control animals. The calcitonin cells in the treated animals generally exhibit an increase in their number up to the 15th day. Mitotic figures are also encountered between the 7th and the 15th day of treatment. This exhibits the increase in the number of C cells. Constant calcium challenge results in increased quantities of secretory granules among these cells up to the 15th day and in degranulation from the 17th day onwards. It also causes degenerative changes in a certain number of C cells. The parathyroids exhibit atrophic changes (25 days onwards) due to chronic hypercalcaemia. For short term hypercalcaemia, animals were injected intravenously with 1 ml of 10% solution of calcium gluconate. The calcitonin cells do not exhibit any change during the first half hour but thereafter they exhibit progressive degranulation, resulting in marked degranulation after 5 hours of the injection. The parathyroids remain unaffected throughout the experiment and show no histological change.
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PMID:Studies of calcitonin cells and parathyroid glands of the Indian palm squirrel, Funambulus pennanti in response to experimental hypercalcaemia. 31 55

Hypercalcemia after renal transplantation (post-T hypercalcemia) has been detected in 29 (16.7%) of 174 long-term survivors. The mean time of onset of hypercalcemia was 69 days after renal transplantation (range 3-210). In 18 patients the hypercalcemia was mild and resolved spontaneously (transient) from 2-65 months (mean 19) after onset. In 4 patients serum calcium normalized concurrently with rejection episodes. In 7 patients the hypercalcemia was more pronounced (permanent), being terminated by subtotal parathyroidectomy in 5 and persisting in 2 recipients. The hypercalcemia was asymptomatic except in one patient, who developed calculi in the graft and a fall in graft function, all of which disappeared after parathyroidectomy. At operation the parathyroid glands showed hyperplasia, except in one case with an adenoma in one of the hyperplastic glands. Serum phosphorus was markedly decreased, to the same extent in transiently and permanently hypercalcemic recipients. Serum parathyroid hormone (S-PTH) was increased in all of 5 patients with permanent and in 3 of 8 with transient post-T hypercalcemia. In normocalcemic and in transiently hypercalcemic recipients the mean S-PTH was identical, but significantly lower than in the permanently hypercalcemic recipients. S-PTH was suppressed to the same extent during an i.v. calcium infusion in patients with post-T hypercalcemia and with primary hyperparathyroidism.
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PMID:Hypercalcemia and parathyroid function after renal transplantation. 31 22

Catecholamines induce bone resorption and hypercalcaemia by the beta-adrenergic effect in bone and hypercalciuria by the alpha adrenergic effect in kidney. The interplay between the alpha-adrenergic hypercalciuria and beta-adrenergic hypercalcaemia explains why in some, but not all, phaeochromocytomas hypercalcaemia occurs. The hypothesis predicts hypercalciuria in both phaeochromocytoma and neuroblastoma. In hyperthyroidism, negative calcium balance and hypercalcaemia cannot be attributed to the direct effect of thyroid hormones on the bone but can be explained by augmentation of the catecholamine effects on bone and kidney by thyroid hormones. The hypothesis offers a solution for an apparent paradox in hyperthyroidism of increased urinary cAMP while nephrogenous cAMP is decreased. It also explains why propranolol corrects hypercalcaemia without influencing renal calcium loss.
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PMID:Catecholamines cause the hypercalciuria and hypercalcaemia in phaeochromocytoma and in hyperthyroidism. 33 Oct 32

The prophylaxis and treatment of renal osteodystrophy are based on pathophysiological principles. Development of secondary hyperparathyroidism should be averted by early prevention of hyperphosphatemia through diet and phosphate ligants, and by normalization of the calcium balance through calcium supplements and vitamin D or its analogues. This treatment requires close clinical and laboratory control in order to avoid several hazards (hypercalcemia, hypophosphatemia, and refractory constipation). In cases with severe secondary hyperparathyroidism, subtotal parathyroidectomy is sometimes required. Nevertheless, in one such case this operation resulted in sudden hypoparathyroidism two years postoperatively.
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PMID:[Treatment of renal osteodystrophy: physiopathology and secondary effects]. 33 72

About 30% of patients with clinical osteoporosis had histological signs of osteomalacia, in spite of normal serum 25-hydroxyvitamin D3 (25-OHD3). The excess osteoid disappeared during treatment with 1alpha-hydroxyvitamin D3 (1alpha-OHD3). These patients might have reduced ability to convert 25-OHD3 to 1,25-dihydroxyvitamin D3 (1,25-(OH)2D3). The intestinal calcium absorption increased during treatment with 1alpha-OHD3, but this was accompanied by a rise in urinary calcium excretion. Photon absorptiometry of the forearm indicated increased bone mineral content during treatment with a daily dose of 2 microgram 1alpha-OHD3 and a supplement of 1 g of calcium. This therapeutic combination, however, caused frequent episodes of hypercalcaemia, so further studies are necessary to evaluate an appropriate dose of 1alpha-OHD3 with or without a calcium supplement.
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PMID:Treatment of senile osteoporosis with 1alpha-hydroxyvitamin D3. 34 43

Four hundred and eighteen measurements of serum ionised calcium, total calcium, and protein concentrations were made from 47 normal volunteers, 104 patients with chronic renal failure (33 being treated conservatively and 71 with regular haemodialysis), and 83 renal transplant recipients. The serum ionised calcium concentration was measured with an Orion SS-20 meter and calculated from the total serum calcium and protein concentrations by using three formulae and a nomogram. In the normal subjects and patients undergoing regular haemodialysis, whose serum calcium concentrations were in or near the normal range, three of the calculations gave results similar to those obtained by direct measurement. In patients with conservatively treated chronic renal failure and those who had received renal transplants, however, there was poor aggrement between the methods. When patients with hypercalcaemia and hypocalcaemia from all the groups were considered separately there was again poor agreement between calculated and measured concentrations of serum ionised calcium. Of the patients whose measured concentrations of serum ionised calcium were high, 69-76% were classified as normal by the four indirect methods. We conclude that calculation of the serum ionised calcium concentrations is not an adequate substitute for direct measurement.
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PMID:Serum ionised calcium concentration: measurement versus calculation. 34 62

Our expanding knowledge of the physiologic and biochemical factors governing calcium homeostasis has improved our capacity to evaluate hypercalcemia, of which an increased incidence is being discovered through the widespread use of multiphasic screening. Consequently, we are diagnosing mild forms of hyperparathryoidism more often than formerly. The enhanced recognition of virtually symptom-free hyperparathyroidism presents a problem in patient management because the natural history of this form of hyperparathyroidism is unknown and the pathologic lesion underlying the condition may be ambiguous, resulting in difficult decisions in surgical management. Further study is required to resolve this issue in order to provide optimal care for the affected individual.
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PMID:Parathyroid hormone and hyperparathyroidism: current concepts. 35 59

Hypercalcemia after renal transplantation (post-TH) was detected in 32 (17%) of 188 long-term survivors. The mean time from renal transplantation (RT) till onset of post-TH was 60 (3-210) days. In 19 patients the hypercalcemia was mild and transient, resolving spontaneously within 1-65 (mean 18) months. In 6 patients s-calcium normalized simultaneously with a rejection episode treated with increased prednisone doses. The hypercalcemia was more pronounced (permanent) in 7 patients, and terminated by subtotal parathyroidectomy in 5 and still persists in 2. The hypercalcemia was asymptomatic and did not affect the function of the graft except in one patient who developed calculi in the graft and a fall in graft function, all of which disappeared after subtotal parathyroidectomy. The frequency of aseptic bone necrosis and spontaneous fractures was the same in recipients with and without post-TH. Serum parathyroid hormone (s-PTH) was significantly higher in patients with permanent than in those with transient post-TH, who had the same slight elevation of s-PTH as the normocalcemic recipients. A permanent course of post-TH can be expected when both s-calcium and s-PTH are persistingly elevated.
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PMID:The clinical significance of hyperparathyroidism after renal transplantation. 35 92


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