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 extensive chromatographic characterization of four parathyroid hormone (PTH)-like proteins in a human bronchial carcinoid tumour associated with humoral hypercalcaemia and severe osteitis fibrosa is described. PTH-like bioactivity was detected in acetic acid extracts of the tumour using an in-vitro osteo-sarcoma cell bioassay. The active tumour proteins were positively charged at physiological pH and had apparent Mr of approximately 29,000, 16,000, 4000-9000 and less than 4000. The proteins were immunologically distinct from PTH, but each stimulated PTH-sensitive adenylate cyclase in cultured osteoblastic cells. There was no evidence of PTH gene expression by the tumour. These proteins represent different molecular forms of PTH-related protein.
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PMID:Multiple forms of parathyroid hormone-like proteins in a human tumour. 254 21

Osteitis fibrosa, a frequent complication of chronic renal failure, is characterized by increased rates of bone formation and bone resorption due to increased secretion of parathyroid hormone (PTH). Effective treatment with oral calcitriol is often impossible in patients with osteitis fibrosa, because low doses may cause hypercalcemia. Because short-term infusions of intravenous calcitriol are capable of suppressing the secretion of parathyroid hormone in patients with uremia without causing hypercalcemia, we evaluated the effectiveness of long-term intermittent calcitriol infusions (1.0 to 2.5 micrograms three times weekly, during dialysis) in treating severe osteitis fibrosa in 12 consecutive patients on hemodialysis whose disease was refractory to conventional therapy. After a mean (+/- SE) treatment period of 11.5 +/- 1.4 months, the mean bone-formation rate declined from 1642 +/- 277 to 676 +/- 106 microns 2 per square millimeter per day (P less than 0.01) in the 11 patients who successfully completed the study. Similar reductions occurred in the osteoblastic osteoid (18 +/- 3 to 9 +/- 2 percent; P less than 0.01) and the degree of marrow fibrosis (6.2 +/- 1.7 to 3.5 +/- 1.3 percent; P = 0.01). Concomitant serum biochemical changes included increased calcium levels (2.55 +/- 0.03 to 2.67 +/- 0.05 mmol per liter; P less than 0.01), decreased alkaline phosphatase levels (489 +/- 77 to 184 +/- 32 U per liter; P less than 0.001), and decreased levels of PTH (amino-terminal, 172 +/- 34 to 69 +/- 16 ng per liter in five patients, P less than 0.03; and carboxy-terminal, 1468 +/- 467 to 1083 +/- 402 ml-eq per liter in six patients, P not significant). Although the majority of the patients had transient episodes of asymptomatic hypercalcemia, this complication could be quickly reversed by temporarily halting treatment or decreasing the dose of calcitriol. We conclude that long-term intermittent infusions of intravenous calcitriol are effective in ameliorating osteitis fibrosa in patients on dialysis. Patients whose osteitis fibrosa is refractory to oral calcitriol and who are candidates for parathyroidectomy should be considered first for intravenous calcitriol therapy.
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PMID:Intravenous calcitriol in the treatment of refractory osteitis fibrosa of chronic renal failure. 274 71

Six patients with progressive chronic renal failure not yet requiring dialysis and not consuming supplemental calcium or vitamin D developed hypercalcemia. Three had proven and 1 suspected tertiary hyperparathyroidism, 1 parathyroid carcinoma and 1 aplastic bone. None of the 3 patients who underwent bone biopsy had heavy bone aluminum staining. The patients with proven parathyroid-mediated hypercalcemia had marked elevation of C-terminal parathyroid hormone and alkaline phosphatase values and, when performed, radiographs consistent with osteitis fibrosa. When these findings are absent or the diagnosis is otherwise uncertain, a bone biopsy may provide a definitive diagnosis and guide management.
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PMID:Hypercalcemia in patients with advanced chronic renal failure not yet requiring dialysis. 275 79

Hyperparathyroidism was described initially in the mid 1920s in patients suffering from a rare and severe form of bone disease, osteitis fibrosa cystica. In the 1940s and 1950s renal stone disease was recognized as a far more frequent complication of primary hyperparathyroidism than bone disease, and approximately half of the patients with primary hyperparathyroidism in clinical series published through the 1970s presented with renal stones. The introduction of routine determination of serum calcium concentration in the mid 1970s has had a dramatic impact on the frequency with which primary hyperparathyroidism is diagnosed in the population, particularly in older individuals with predominantly nonspecific symptoms of the disease. Stone complications appear to occur in less than 10 per cent of such patients. Underlying primary hyperparathyroidism is diagnosed in approximately 1 to 5 per cent of the patients with calcium stone disease. The predominant risk factor for stone formation in primary hyperparathyroidism is hypercalciuria, and patients typically present with moderate to marked hypercalciuria but with only mild hypercalcemia, in the range of 11 mg. per dl. or less. Hypercalciuria in these patients is principally the result of 1,25-dihydroxyvitamin D-mediated hyperabsorption of calcium from the intestine. The pattern of hypercalciuria disproportionate to the degree of hypercalcemia that typifies patients with primary hyperparathyroidism and stone disease reaches an extreme degree in patients with so-called subtle or normocalcemic primary hyperparathyroidism, in whom diagnosis by routine techniques may be difficult. Parathyroid exploration remains the treatment of choice in patients with primary hyperparathyroidism and stone complications.
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PMID:Primary hyperparathyroidism. 291 15

Renal failure is frequently associated with osteodystrophia due to secondary hyperparathyreoidism and/or increased aluminum intake. The problem of hypercalcemia and hyperphosphatemia can more easily controlled by CAPD than by hemodialysis. Total serum and ionized calcium levels are rapidly normalized by a CAPD regime of four 2-1 exchanges with 1.75 mmol/l Ca. Under the same CAPD regime 250-300 mg phosphate are removed per day. Depending on the ingestion of phosphate, 100-200 mg phosphate per day remain to be removed by phosphate binding agents. Since the main source of aluminum in CAPD patients is oral ingestion of aluminum-containing phosphate binders, serum levels should be regulated by diet and calcium carbonate. To suppress PTH secretion serum ionized calcium levels need to be maintained at the upper limit of normal. This can also be achieved by the use of oral calcium carbonate. Vitamin D or analogs should be prescribed only when clinically indicated by persistent hypocalcemia, osteitis fibrosa or non-aluminum related osteomalacia.
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PMID:Renal osteodystrophy and aluminum bone disease in CAPD patients. 305 62

Two patients with long-standing hyperparathyroidism due to a parathyroid adenoma are described. Both had severe osteitis fibrosa cystica and a proximal myopathy. Both were treated with alfacalcidol (2 micrograms/day) prior to and following parathyroidectomy, and infused with calcium gluconate following the operation. Plasma total and ionized calcium and magnesium concentrations were maintained within the normal range. However, both developed tetany in the postoperative period in spite of normal ionized calcium and magnesium concentrations. Tetany continued for 4 weeks in one patient and for longer in the other. Prolonged hypercalcaemia may result in a state of neuromuscular excitability following parathyroidectomy even at high normal concentrations of ionized calcium.
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PMID:Tetany despite normocalcaemia and normomagnesaemia following parathyroidectomy. 344 16

A syndrome of pulmonary alveolar septal calcinosis, pneumothorax, and pneumomediastinum, leading to rapidly progressive acute respiratory insufficiency and death was observed in 2 children with acute lymphoblastic leukemia (ALL). Primary clinical and radiological considerations in these patients were pulmonary edema and infection, and the diagnosis of pulmonary alveolar septal calcification was established only at autopsy. One patient, a 15-year-old girl, was found also to have parathyroid hyperplasia typical of familial hyperparathyroidism. The other, a 16-month-old girl, showed osteitis fibrosa of the bones and parathyroid hyperplasia of secondary type, suggesting that the pulmonary calcinosis resulted from hypercalcemia caused by a parathormone or prostaglandin-secreting tumor. The cause of pneumothorax and pneumomediastinum may have been rupture of calcified alveolar septa induced by high PEEP during ventilation of these patients. Other possible mechanisms contributing to hypercalcemia and pulmonary calcinosis in children with acute leukemia include bone resorption due to marrow infiltration, immobilization syndrome, renal failure, and administration of calcium, phosphate, or bicarbonate. This complication of acute leukemia in childhood is rare (2 patients in 430 autopsied over the period 1961-1982 at Childrens Hospital of Los Angeles). How often the process can be reversed if diagnosed before severe respiratory insufficiency is present is not known.
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PMID:Pulmonary alveolar septal calcinosis causing progressive respiratory failure in acute lymphoblastic leukemia in childhood. 347 56

We report on a 5-year, prospective, double-blind trial of 1,25 dihydroxycholecalciferol (calcitriol) versus placebo in 76 hemodialysis patients without biochemical or radiological evidence of bone disease. Calcitriol, 1 microgram daily, regularly induced hypercalcemia. Doses of 0.25 microgram daily or less proved satisfactory in most patients. During calcitriol treatment, plasma calcium concentration was significantly higher and serum parathyroid hormone concentration significantly lower than on placebo. There was no difference in the rates of development or of progression of vascular calcification in the two groups. Significantly more patients on placebo (17 vs. 6, p less than 0.05) developed a sustained elevation of plasma alkaline phosphatase concentration. Calcitriol appeared to protect against the development of histological evidence of osteitis fibrosa but not of osteomalacia, but accumulation of aluminum in bone occurred during the study. We conclude that calcitriol delays and may prevent the development of osteitis fibrosa in patients receiving regular hemodialysis and may reasonably be prescribed routinely in hemodialysis patients without biochemical or radiological abnormality, unless there is a substantial prospect of early renal transplantation.
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PMID:Controlled trial of calcitriol in hemodialysis patients. 353 32

The metabolic manifestations and operative findings in 10 patients with a diagnosis of parathyroid carcinoma were analyzed to determine whether they differ from those in patients with parathyroid adenomas and similar degrees of hypercalcemia. Two groups of patients with parathyroid adenomas were used for comparison. Group A consisted of eight patients with "atypical" benign adenomas (mean preoperative level of serum calcium: 13.4 mg/dl); group B consisted of 13 patients with benign typical adenomas--all with preoperative serum calcium levels greater than or equal to 13.0 mg/dl (mean: 14.2 mg/dl). The patients with carcinoma (mean preoperative level of serum calcium: 15.3 mg/dl) had a frequency of osteoporosis and osteitis fibrosa cystica (50%) comparable with that of group A (33%) and group B (62%). Seventy percent of the patients with carcinoma had renal disease (nephrolithiasis, nephrocalcinosis, or impaired renal function), whereas only 38% of group A and 15% of group B had similar disorders. The patients with carcinomas had the highest frequency of combined bone and renal disease (50% versus 14% in group A and 15% in group B). Anemia, peptic ulcer disease, and hypertension occurred with similar frequencies in the three groups. Three patients with recurrent parathyroid carcinoma died of profound hypercalcemia, renal failure, or cardiac arrhythmia. In general, although patients with parathyroid carcinomas have more profound metabolic abnormalities than do patients with primary hyperparathyroidism, the metabolic manifestations in patients with parathyroid carcinoma are comparable with those in patients with parathyroid adenomas and profound hypercalcemia. Furthermore atypical adenomas share many anatomic and histopathologic features with parathyroid carcinomas, and distinguishing between the two is sometimes possible only in cases of tumor recurrence.
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PMID:Parathyroid carcinoma versus parathyroid adenoma in patients with profound hypercalcemia. 358 61

This is a first report of primary hyperparathyroidism (HPT) masquerading as a destructive fibrous sphenoid sinus "Brown tumor" associated with progressive blindness and hypercalcemia. Diagnosis of a Brown tumor was delayed despite serial computerized tomography of the head and repeated transnasal and transethmoid sphenoid biopsies demonstrating diffuse fibrosis. Only detection and medical evaluation of hypercalcemia, demonstrating elevation of both serum calcium and C-terminal parathyroid hormone with an elevated chloride/phosphate ratio, prompted neck exploration, thus confirming a solitary left superior parathyroid adenoma. Postoperative normocalcemia occurred synchronously with the return of light perception and the arrest of sphenoid sinus and parasellar erosion. Although maxillary Brown tumors of secondary HPT have been reported, this is the first report of osteitis fibrosa of the sphenoid sinus. Differential diagnosis of an erosive sphenoid lesion with cranial nerve dysfunction, exclusive of inflammatory or vascular disease, should include sarcoidosis, primary and metastatic sphenoid carcinoma, fibrous dysplasia, giant cell reparative granuloma, midline lethal granuloma, chordoma, and chondrosarcoma. Furthermore, the bony destructive lesions with concomitant hypercalcemia of sarcoidosis and HPT are distinguishable by radiographic and laboratory analyses and by the Dent corticosteroid suppression test. Hypercalcemia of primary HPT is associated with elevated serum C-terminal parathormone, osteitis fibrosa, a negative Dent test, and a chloride/phosphate ratio greater than 33 in 94% of primary HPT patients. Hypercalcemia of sarcoidosis is associated with a normal or decreased C-terminal parathormone assay and a positive Dent test, as well as elevated serum immunoglobulins and erythrocyte sedimentation rate, and a positive angiotensin-converting enzyme assay.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Sphenoid sinus brown tumor, hypercalcemia, and blindness: an unusual presentation of primary hyperparathyroidism. 379 83


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