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)

The early fine structural changes in the arteries of rats induced by excess vitamin D3 perorally or parenterally were essentially similar, except the latter had a more prominent toxic effect to the vascular wall. The ultrastructural features, incidental to calcification, included the appearance of increased ground substance with a separation of collagenous and elastic fibrils, and degenerative changes in smooth muscle cells. Atherosclerosis was greatly accelerated at the sites of vascular injury when cholesterol, cholic acid and thiouracil were added to the basal diet. Calcification was initially observed in relation to elastic fibrils or degenerated cells in the upper and middle layers of the arteries, although there were few such deposits in the thickened intima of the coronary arteries. Calcium deposition could not be a direct effect of hypercalcemia, but the functional activity of smooth muscle cells did seem to promote the mineralization of calcium and phosphate. Furthermore, vitamin D-induced sclerosis did not prevent intimal thickening of the arteries when vitamin D3 was withdrawn.
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PMID:Vitamin D sclerosis in rats. 22 74

Comparison of the mechanism of action Vitamin D3 and 1 alpha-OH D3 under conditions of experimental hypercalcemia. Acta Physiol. Pol. 1979, 30 (2): 313--318. The hypercalcemic effect of supraphysiological doses of Vitamin D and 1 alpha-OH D3 were compared applying an animal model. Changes in serum calcium of animals with normal dietary calcium supplementation and those under conditions of calcium depletion were analyzed. Dietary calcium is necessary for the hypercalcemic effect of Vitamin D, whereas in case of 1 alpha-OH D3 calcium is mobilized not only from the dietary but also from some other sources. The analysis of the hypercalcemia kinetics in the Vitamin D and 1 alpha-OH D3 treated animals indicated that the kidney 1 hydroxylase of 25 hydroxycholecalciferol is an important step in the hypercalcemia preventing mechanism.
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PMID:Comparison of the mechanism of action of vitamin D3 and 1 alpha-OH D3 under conditions of experimental hypercalcemia. 22 75

Calcium balance studies and measurement of 25-hydroxyvitamin D3 (25[OH]D3) levels were performed on a vitamin D intoxicated, hypoparathyroid patient before, during, and after successful management of hypercalcemia with oral prednisone therapy. Prednisone effected a dramatic reduction in both mean serum calcium levels and mean 24-hour urinary calcium excretion within four days on two separate occasions. No changes were apparent in fecal calcium excretion. Calcium balance became less negative with prednisone treatment. Levels of 25(OH) D3 during the same period did not change. Decreased calcium mobilization from bone best accounted for the glucocorticoid-mediated amelioration of hypercalcemia.
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PMID:Glucocorticoid effects in vitamin D intoxication. 22 30

The occurence of hypercalcemia appears to be unusual in leukemia. The mechanisms are numerous: secretion of PTH of PTH like substance, prostaglandin E2 or vitamin D like sterols. The reported case is one of lymphoblastic acute leukemia and hypercalcemia associated with osteoclast activating factor secreted by leukemic cells. In this patient the serum levels calcium closely paralleled the course of acute leukemia.
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PMID:[Hypercalcemia and osteoclast activating factor (OAF) associated with acute lymphoblastic leukemia (author's transl)]. 22 85

The myopathy associated with vitamin D deficiency has not been well characterized, and it is not known if weakness is a result of a specific effect of vitamin D deficiency on skeletal muscle. Chicks were raised from hatching on a vitamin D-deficient diet, and by 3 wk of age were hypocalcemic and appeared weak. Tension generated by triceps surae during repetitive stimulation of posterior tibial nerve was significantly less than that developed by chicks given vitamin D(3) supplements (309 g tension/g wet weight of triceps surae, SD 60, for vitamin D-deficient chicks; 470, SD 77, for vitamin D(3)-treated chicks, P < 0.01). Histochemical and electron microscopic examination of skeletal muscles of these chicks showed no abnormalities, and there were no electrophysiologic evidences of motor nerve or neuromuscular junction dysfunction. The concentration of ATP in skeletal muscle of the vitamin D-deficient chicks (5.75 mumol/g wet weight, SD 0.17) was not significantly different from that in vitamin D-treated chicks (5.60, SD 0.50). There was no correlation between strength and serum calcium, serum inorganic phosphate, or skeletal muscle inorganic phosphate. Relaxation of tension after tetanic stimulation was slowed in the vitamin D-deficient chicks (20.6 ms, SD 1.7, vs. 15.4, SD 1.3, in vitamin D-treated chicks and 15.3, SD 1.0, in normal control chicks), and in vitro (45)Ca(++) transport by sarcoplasmic reticulum from the vitamin D-deficient chicks was reduced. Calcium content of mitochondria prepared from leg muscles of vitamin D-deficient chicks (24 nmol/mg mitochondrial protein, SD 6) was considerably lower than that of mitochondria from normal control chicks (45, SD 8) or from chicks treated with vitamin D for 2 wk or more (66-100, depending upon level and duration of therapy). Treatment of the vitamin D-deficient chicks from hatching with sufficient dietary calcium to produce hypercalcemia did not significantly raise skeletal muscle mitochondrial calcium content (31 nmol/mg mitochondrial protein, SD 7) and did not prevent weakness. These studies demonstrate objective weakness as a result of myopathy in vitamin D-deficient chicks, and provide evidence that vitamin D deficiency has effects on skeletal muscle calcium metabolism not secondary to altered plasma concentrations of calcium and phosphate.
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PMID:Skeletal muscle calcium metabolism and contractile force in vitamin D-deficient chicks. 22 25

Acute massive vitamin D overdosage occurred in a family after eating food cooked in a nut oil containing 5 million units of vitamin D3/ml. The plasma vitamin D was 55 and 60 i.u./ml in the father and mother respectively, and 9.6 i.u./ml in their 11-month-old infant (normal range, 0--1.6 i.u/ml). All the family presented with symptoms of hypercalcaemia and the infant responded quickly to prednisone. After steroids had failed to control the hypercalcaemia in the parents, neutral phosphate was successful, although necessary for 9 months. Before phosphate therapy it was shown that both parents were in strongly negative calcium balance, indicating that the vitamin D was mobilizing calcium from bone. Eleven years later all 3 patients are well but a renal biopsy in one of them shows persistent nephrocalcinosis.
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PMID:A family with massive acute vitamin D intoxication. 23 12

Twelve children with chronic renal failure (CRF) and sixteen children receiving regular dialysis therapy (RDT) were treated with between 10,000 and 50,000 IU of vitamin D daily. This was associated with an increase in serum calcium levels and reduction in PTH levels. In the children with CRF, secondary hyperparathyroidism was improved with treatment but its development was not completely prevented nor was healing complete. In the patients receiving RDT, treatment with vitamin D improved the changes associated with secondary hyperparathyroidism in 50% of cases but these features sometimes reappeared despite continuing treatment. Hypercalcaemia or metastatic calcification was not seen. Subsequently, 1,25(OH)2D3 was administered to 14 children receiving RDT. This was associated with the return of serum calcium levels to normal, inhibition of PTH synthesis and an improvement in intestinal calcium absorption. Fibro-osteoclasia was cured and there was improvement in actual bone resorption. There was also improvement in osteoidosis in those children who showed disturbances of mineralisation. Calcification in the limbus area of the eyes may occur and hypercalcaemia was seen commonly. Treatment with 1,25(OH)2D3 should only be offered to children with severe renal bone disease. Neither vitamin D3 nor 1,25(OH)2D3 can guarantee complete recovery of osteodystrophy and of growth arrest in uraemic children.
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PMID:Renal bone disorders in children: therapy with vitamin D3 or 1,25-dihydroxycholecalciferol. 23 17

Three indices of circulating parathyroid hormone (PTH) activity were compared between two groups: the first a group of 23 patients from three large kindreds with autosomal dominant hypercalcemia without hypercalciuria [familial hypocalciuric hypercalcemia (FHH)] and the second a group of 64 patients with typical primary hyperparathyroidism (1HPT) manifesting comparable hypercalcemia. The group with 1HPT differed from normal with respect to plasma PTH 1HPT concentration (normal, less 0.2 ng/ml), urinary cAMP excretion per 100 ml glomerular filtrate (U cAMP/GF) (normal, 2.3 x/divided by 0.6 nmol/100 ml glomerular filtrate; mean, x/divided 1 SD), and renal tubular maximum of phosphate transport corrected for glomerular filtration rate (TMP/GFR; normal, 3.4 +/- 0.4 mg/dl; mean, +/- 1 SD). The group with 1HPT also diverged significantly from the group with FHH for all three indices: for PTH, 0.37 x/divided by .48 vs. 0.25 x/divided .46 (P less than 0.05); for UcAMP/GF, 4.3 x/divided by .53 vs. 2.6 x/divided .60 (P less than 0.0005); and for TMP/GFR, 2.0 +/- 0.6 vs. 2.6 +/- 0.7 (P less than 0.01). The between-group differences for all three indices were also significant after adjustment for their variation with serum calcium. However, only the difference in TMP/GFR remained significant after adjustment for covariance attributable to serum calcium concentration, age, and creatinine clearance. The group with FHH differed from normal for TMP/GFR but not for UcAMP/GF. However, analysis of changes in UcAMP/GF and serum calcium concentration around the time of parathyroidectomy in three patients with FHH suggested that the parathyroid glands contributed to the abnormalities of mineral homeostasis in at least one. It was concluded that higher serum concentrations of PTH do not account for the lower renal clearance of calcium and magnesium in FHH calcium concentration, the group with FHH showed indices suggesting lower circulating PTH activity than the group with 1HPT.
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PMID:Circulating parathyroid hormone activity: familial hypocalciuric hypercalcemia versus typical primary hyperparathyroidism. 23 92

Parathyroid (PT) glands from 20-day-old embryonic chicks cultured in a chemically defined medium secreted a stimulator of in vitro bone resorption. This stimulator was presumed to be parathyroid hormone (PTH) because: 1) the in vitro dose response curve was parallel to that obtained with bovine PTH; 2) the activity was eluted on Sephadex G-1--chromatography at a postition similar to that for PTH; and 3) the material produced hypercalcemia in vivo in chicks. The amount of PTH-activity secreted was inversely proportional to the calcium concentration of the medium over the range of 0.75-2.25 mM. The chick PT glands also secreted an inhibitor of PTH-stimulated bone resorption in vitro. This inhibitor was presumed to be calcitonin (CT) because: 1) the in vitro dose-response curve was parallel to that obtained with synthetic salmon CT; 2) the activity was eluted on Sephadex G-50 chromatography at a position similar to that for salmon CT; and 3) the material produced hypocalcemia in vivo in rats. In contrast to what would be expected for CT secretion, the CT-activity was secreted by the PT glands in response to a low, not high calcium concentration. The data suggest that the secretion of avian PTH is similar to that of the mammalian hormone, and that the ultimobranchialectomized chick with an intact parathyroid gland may not be deficient in CT.
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PMID:The detection of transmissible gastroenteritis viral antigens by immunodiffusion. 23 83

Using a whole body radiation detector, we have measured the total body retention of 47-Ca 7 days after oral administration of the isotope to patients with various disorders of calcium metabolism. The percent retention of 47-Ca given with 90 mg of unlabeled (carrier) calcium varied with the calcium metabolic status as follows: normals (n equals 14), 33-43 percent (mean 38); primary hyperparathyroidism (n equals 28), 32-74 percent (mean 52); idiopathic hypercalciuria (n equals 9), 34-49 percent (mean 42); and hypercalcemia of other etiology (n equals 3), 23-26 percent (mean 25). Almost half (13/28) of those with hyperparathyroidism showed a retention above 55 percent, distinguishing them from subjects with idiopathic hypercalciuria. Retention of 47-Ca correlated poorly with clinical measures of severity of hyperparathyroidism. When isotope was diluted with a smaller amount of carrier calcium (20 mg), retention was increaseed in normals (n equals 5) to 46-54 percent (mean 50) and in hyperparathyroidism (n equals 5) to 64-87 percent (mean 73). After surgical cure of hyperparathyroidism retention of isotope returned toward normal in 5 of 7 subjects. Whole body retention of orally administered 47-Ca may prove useful in detecting hyperparathyroidism in subjects with mild hypercalcemia or hypercalciuria.
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PMID:Total body retention of orally administered 47-calcium in primary hyperparathyroidism. 23 21


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