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)

Renal handling of phosphorus was studied in the following groups of parathyroidectomized rats with maleate-induced Fanconi syndrome: 1) 6 rats receiving intravenous parathyroid hormone, 2) 6 rats receiving intravenous dibutyryl cyclic AMP (DBcAMP), 3) 6 rats undergoing volume expansion with saline, 4) 12 rats receiving intravenous 25 (OH)vitamin D3, 5) 12 rats with acute hypercalcemia induced by intravenous CaCl2, 6) 6 rats with phosphate deprivation, and 7) 6 rats receiving intravenous calcitonin. Parathyroid hormone and calcitonin failed to increase the urinary excretion of both cAMP and phosphorus. Likewise, DBcAMP failed to increase the urinary excretion of phosphorus. Extracellular volume expansion and hypercalcemia (serum calcium 12.9 +/- 0.7 mg/100 ml) did not alter the tubular reabsorption of phosphorus. In phosphate-deprived animals, the fractional excretion 0.16 +/- 0.05 (mean +/- SE) was lower than that in the control animals (maleate-treated without phosphate depletion), 0.46 +/- 0.04 (P less than 0.001). 25 (OH)vitamin D3 decreased the fractional excretion of phosphorus from 0.39 +/- 0.03 in the control (maleate-treated not receiving 25 (OH)vitamin D3) to 0.23 +/- 0.02 (P less than 0.001) in the experimental animals. The present study demonstrated an antiphosphaturic effect of 25(OH)vitamin D3 in experimental Fanconi syndrome; the mechanism of this action is not well understood.
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PMID:Antiphosphaturic action of 25 (OH) vitamin D3 in experimental Fanconi syndrome. 21 76

In a patient with hypercalcaemia secondary to a renal-cell carcinoma, a concentration gradient of bioactivity was detected between the tumour effluent vein and the peripheral venous blood that was capable of stimulating adenylate cyclase in bone cells. Immuno-reactive PTH was undetectable in the tumour effluent and in the peripheral blood. It is concluded that a non-parathyroid humoral factor whose action involved cyclic AMP stimulation was responsible for the hypercalcaemia.
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PMID:Humoral hypercalcaemia in a patient with renal-cell carcinoma. 21 93

Refractory hypercalcemia developed suddenly in a patient who had undergone a radical cystectomy for an anaplastic transitional cell carcinoma of the bladder. A normal serum parathyroid hormone (PTH) value was obtained by immunoassay while the patient had hypercalcemia and unimpaired renal function. This normal PTH value in the presence of hypercalcemia was consistent with his hypercalcemia being secondary to excessive amounts of circulating PTH. The finding of increased nephrogenous cyclic AMP, however, provided the definitive diagnosis of hyyperparathyroidism. Since autopsy revealed that there was no residual tumor in the bladder area, only evidence of metastatic disease, and since the parathyroid glands were not hyperplastic or adenomatous, we attributed this patient's hypercalcemia to hyperparathyroidism due to the ectopic production of PTH by a metastasis from the transitional cell carcinoma of the bladder.
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PMID:Fulminating hypercalcemia and markedly increased nephrogenous cyclic AMP in a patient with transitional cell carcinoma of the bladder. 22 Aug 74

The question of parathyroid autonomy in primary hyperparathyroidism has been the subject of conflicting immunoassay data. We studied the effects of calcium infusion (12 mg/kg/3h) and calcium injection (3 mg/kg/10 min) on peripheral plasma parathyroid hormone (iPTH) determined with a multivalent antiserum and on the excretion of nephrogenous cyclic AMP in normal subjects and in 7 patients with primary hyperparathyroidism who displayed only mild, intermittent hypercalcemia. In control subjects, calcium administration resulted in small (13-20%) reductions in iPTH, whereas some 4/5 (77-81%) of the nephrogenous cyclic AMP was rapidly and uniformly suppressed. In the patients with primary hyperparathyroidism, both analyses revealed a lack of absolute parathyroid autonomy in response to calcium, with overlapping iPTH responses between a majority of the patients and the control group. In contrast, the nephrogenous cyclic AMP responses provided a clear separation of the 2 groups after both calcium infusion and calcium injection (mean values for both studies, patients: 2.93 nmol/100 ml GF vs. normal sugjects: 0.38 nmol/100 ml GF), and measurements of total cyclic AMP excretion also clearly distinguished the 2 groups. When a sensitive antiserum with predominantly carboxy-terminal reactivity was employed, the iPTH responses to calcium injection provided an improved separation of patients and normal subjects. The data suggest that 1) although parathyroid autonomy is not, in general, a feature of primary hyperparathyroidism, abnormal parathyroid suppressibility is easily demonstrated even in patients with a subtle form of the disorder; 2) the determination of nephrogenous cyclic AMP provides an optimal method for assessing rapid changes in parathyroid function; and 3) the interpretation of iPTH results from such studies is dependent on a number of technological features of the assay employed.
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PMID:Effects of the intravenous administration of calcium on nephrogenous cyclic AMP: use as a parathyroid suppression test. 22 21

A leiomyoma of the small bowel produced laboratory features of hyperparathyroidism which disappeared promptly after tumour resection. Hypercalcaemia, hypophosphatemia, hyperchloremia, elevated chloride/phosphorus ratio, increased urinary cyclic AMP, and blood levels of immunoreactive parathormone were present. Electron microscopy showed dense round granules in the tumour cells.
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PMID:[Leiomyoma of the small bowel with hypercalcaemia: presence of a substance with parathormone activity (author's transl)]. 53 84

We describe a boy who presented at 4 years of age with radiological hyperparathyroidism, osteosclerosis, and necrosis of the femoral heads. Plasma biochemistry was normal but the parathyroid hormone (PTH) level was very high. He was deaf and had an unusual facies but did not have the phenotype of Albright's hereditary osteodystrophy. Plasma and urine cyclic AMP reponses to bovine PTH were markedly subnormal. Vitamin D produced sustained hypercalcaemia and a fall in plasma phosphorus. After four hyperplastic parathyroid glands were removed he became hypocalcaemic and plasma phosphorus rose. After operation he remained unresponsive to exogenous PTH; We suggest that he had a form of pseudohypoparathyroidism without the phenotype of Albright's hereditary osteodystrophy and with some residual skeletal and renal responsiveness to PTH.
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PMID:Normocalcaemic pseudohypoparathyroidism with unusual phenotype. 64 42

Patients with breast cancer and bone destruction were found to have a pattern of calcium metabolism which was broadly similar to that found in other malignancies, but different from that in primary hyperparathyroidism. Thus, they tended to have reduced absorption of calcium from the intestine, elevated endogenous faecal calcium and normal or reduced urinary cyclic AMP excretion. Since prostaglandin synthetase inhibitors have been shown to inhibit breast cancer-induced osteolysis in vitro we have attempted to reduce bone destruction and serum calcium in patients with hypercalcaemia complicating breast cancer using these agents. High doses failed to reduce the serum calcium or the urinary hydroxyproline: creatinine ratio in ten patients with skeletal metastases, four of whom had hypercalcaemia.
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PMID:Calcium metabolism in breast cancer. 87 Sep 1

The use of intravenous procaine in the treatment of hyperpyrexia in a patient with hyperparathyroidism has not been previously reported. A case of metastatic malignant melanoma precipitating the syndrome of hypertonicity of muscle, hyperpyrexia, acidemia, hypercalcemia and elevated serum parathormone levels is presented. Mithramycin was used in an attempt to reduce elevated serum calcium concentrations. The use of intravenous procaine in "caffeine rigor" and malignant hyperthermia due to succinylcholine and halothane formed the basis for its trial in this case. The relationship between cyclic AMP and calcium ions is discussed in postulating mechanism of procaine action.
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PMID:The use of procaine in acquired malignant hyperthermia in a patient with malignant melanoma metastatic to the parathyroid gland: a case report. 99 Sep 78

Serum immunoreactive parathyroid hormone (iPTH) levels were increased in a 15 year old girl with pseudohypoparathyroidism, hypocalcemia, hyperphosphatemia, and minimal phosphaturic and absent hypercalcemic responses to exogenous parathyroid extract (PTE). Following normalization of the serum calcium concentration with vitamin D, serum iPTH and phosphate concentrations returned to the normal range, and phosphaturia could be clearly stimulated and hypercalcemia induced by PTE. On the other hand, the urinary cyclic adenosine 3',5'-monophosphate (cyclic AMP) excretion could not be stimulated, suggesting that in this case, there appears to be no relationship between the urinary excretion of cyclic AMP and the phosphaturic effect of PTE. The minimal phosphaturic effect and the lack of hypercalcemic effects of PTE in untreated pseudohypoparathyroidism can be explained by the secondary hyperparathyroidism causing elevated iPTH levels rather than by a defect at the level of the receptor sites. A requirement of pharmacologic amounts of vitamin D per se, however, for the responsiveness of patients with pseudohypoparathyroidism to PTE cannot be ruled out.
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PMID:Pseudohypoparathyroidism. Disappearance of the resistance to parathyroid extract during treatment with vitamin D. 113 47

Parathyroid hormone (PTH) and PTH-related protein (PTHrP) act via PTH receptors in bone to stimulate bone resorption. Bone resorption is also stimulated by certain cytokines, which are produced in bone and bone marrow. The effects of such cytokines on the PTH-receptor system were studied in the osteoblast-like osteosarcoma cell line UMR 106-06. 125I-labelled PTHrP-(1-84)-peptide bound specifically to the cells, and PTHrP-(1-34) and -(1-84) competed with equimolar affinity for binding to UMR 106-06 cells. The specific binding of 125I-PTHrP-(1-84) could be completely blocked by PTH. Therefore 125I-PTHrP-(1-84) bound to a classical receptor in UMR 106-06 cells. Preincubation for 3 days with either tumour necrosis factor alpha (TNF alpha) or retinoic acid (RA) both decreased the specific binding of 125I-PTHrP-(1-84) to about 40% of control levels. These effects were specific for PTH binding, since there was little effect on 125I-salmon-calcitonin binding. Both TNF alpha and RA required 24 h exposure to cells to produce a measurable effect. The decrease in 125I-PTHrP-(1-84) binding was due to a reduced number of binding sites, with little apparent change in affinity. Half-maximal effects were seen with 1 ng of TNF alpha/ml, whereas 1 microM-RA was needed to observe the loss of PTH receptors. Combinations of RA and TNF alpha produced a greater effect than that of either agonist alone. The loss of PTH receptors was accompanied by a specific loss of PTH-stimulated cyclic AMP production. Preincubation with TNF alpha increased the basal plasminogen activator (PA) activity in the cells and decreased the amplitude of the response of PA activity to PTH compared with control cells. Furthermore TNF alpha decreased sensitivity to PTH (50% stimulation of PA activity with 0.1 nM-PTH in control cells versus 50% stimulation with 0.3 nM-PTH in TNF alpha-treated cells). In contrast, TNF alpha pretreatment increased the amplitude of the response of PA activity to calcitonin, whereas sensitivity to calcitonin was not altered. These data are consistent with a specific down-regulation of PTH receptors in osteoblast-like UMR 106-06 cells after exposure to TNF alpha or RA. The loss of PTH receptors is accompanied by a decreased responsiveness to PTH, as measured with the PA system in these cells. A loss of PTH receptors could modulate PTH responses in osteoblasts, either in the local control of bone formation and resorption, or in pathological conditions such as humoral hypercalcaemia of malignancy.
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PMID:Specific down-regulation of parathyroid hormone (PTH) receptors and responses to PTH by tumour necrosis factor alpha and retinoic acid in UMR 106-06 osteoblast-like osteosarcoma cells. 166 Jul 13


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