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Query: UMLS:C0020437 (hypercalcemia)
 10,293 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In the submitted review the author pays attention to mechanisms of control of insulin secretion and the mutual interaction of other messengers (cAMP, calcium and inisitol triphosphate) with special attention to the calcium signal which plays a most important role in the stimulation of the excitable B cell. The trigger of the two-stage insulin secretion is cyclic accumulation of calcium in the cytosol of the B cell and the mutual harmony between calcium of the intra- and extracellular compartment. In the early stage of insulin secretion in particular the intracellular compartment is the source of calcium; from there the ion is released due to the action of inositol triphosphate (IP3) activated by phospholipase C. Calcium of the extracellular compartment is mobilized also in the early secretory stage by opening of the depolarization-dependent calcium channels, it plays, however, a more important part during the second stage. Activation of the other messengers, incl. the calcium signal, depends on the type of secretagogue stimulus. During systemic changes of calcium homeostasis in vivo the calcium signal of the B cell is activated or inhibited in different ways. In the course of hypercalcaemia, in particular if acute, the direct influence of calcium ions on insulin secretion is modulated by further factors, e.g. somatostatin, calcitonin, cholecystokinin, glucagon, adrenocortical hormones, opioids and other substances released into the blood stream. In chronic hypercalcaemia which is the result of primary hyperparathyroidism or vitamin D intoxication the action of calcium on the metabolic and hormonal response is enhanced by the ionophoretic action of parathormone or active vitamin D metabolites.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[The calcium signal in the regulation of insulin secretion]. 269 62

Aluminium-containing phosphate binders were replaced by a calcium and magnesium carbonate-containing antacid in 20 patients on long-term haemodialysis, over a three-month period in all of them, for 12 months in ten. After two months the serum aluminium level fell (mean +/- SD) from 3.0 +/- 1.6 to 1.4 +/- 0.5 mumol/l (P less than 0.001). After three months the serum phosphate level had fallen from 1.8 +/- 0.4 to 1.5 +/- 0.4 mumol/l (P less than 0.05), while during the same period parathormone (PTH-NH2) fell from 1.4 +/- 1.4 to 0.8 +/- 0.7 ng/ml (P less than 0.05). Serum total calcium concentration rose after two months from 2.2 +/- 0.2 to 2.4 +/- 0.2 mmol/l (P less than 0.001). In a third of patients the uraemic acidosis was corrected, standard bicarbonate rising from 18 +/- 2 to 21 +/- 3 mmol/l (P less than 0.05). Serum pH, potassium, sodium, magnesium and alkaline phosphatase did not change significantly. Hypercalcaemia was an expected disadvantage: repeated symptom-free episodes of hypercalcaemia occurred in six of 20 patients during the first three months and in a further two up to 12 months. These episodes were successfully controlled by a reduction of CaCO3/MgCO3 dosage and readministration of Al(OH)3. Extraosseous calcifications were not observed.
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PMID:[Replacement of aluminum-containing phosphate binders by calcium and magnesium carbonates in long-term hemodialysis]. 270 34

Clinical investigations have shown that 1 alpha-hydroxycholecalciferol (oxydevit, alphacalcidiol) and 1 alpha, 25-dihydroxycholecalciferol (rocaltrol) are act vitamin D3 agents producing a positive clinical effect in different types of osteoporosis and osteomalacia. Clinical improvement of the patients' status (alleviation of the pain syndrome, an increase in motor activity) was noted in 1-2 mos., an x-ray picture of regeneration of the bone structure of both axial and peripheral skeleton--in 6-12 mos. after the initiation of therapy. Therapy was attended by an increase in the serum content of total and ionized calcium, the return of alkaline phosphatase activity to normal, and a decrease in the level of parathormone. During prolonged therapy these agents administered at daily doses of 0.25-2 micrograms caused no pathological side-effects and hypercalcemia. In osteoporotic conditions all these drugs were equal in their clinical effectiveness. Rocaltrol has some advantages in the presence of associated liver pathology.
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PMID:[Comparative evaluation of the effectiveness of vitamin D3 preparations (1-alpha-hydroxy- and 1-alpha,25-dihydroxycholecalciferol in various forms of osteoporosis and osteomalacia]. 276 60

The "N-tact" immunoradiometric assay (IRMA) from INCSTAR for parathyrin (PTH) in serum involves a 125I-labeled affinity-purified antiserum to PTH 1-34 and an affinity-purified antiserum to PTH 39-84, the latter bound to a polystyrene bead. The mean detection limit, determined in six consecutive assays, was 4 ng/L. The within-batch CV was less than 7% in the range 15 to 2135 ng/L. The between-batch CV was 11.7% and 5.3% at 30 and 371 ng/L, respectively. Serum PTH in 14 proven cases of primary hyperparathyroidism was 49-808 (median 111) ng/L, undetectable (less than 5 ng/L) in 10 cases of primary hypoparathyroidism and in 10 cases of hypercalcemia associated with malignancy, compared with 7-39 ng/L in 45 normal subjects. PTH was 9 to 19 ng/L in four patients with familial benign hypercalcemia. In 39 patients with renal failure, apparent concentrations were 14 to 857 (median 133) ng/L, but sera from these patients pre-diluted with zero standard did not parallel dilutions of the standard, PTH 1-84. PTH concentrations were not significantly decreased in blood or serum kept at 20 degrees C for up to 6 h. After successful removal of a parathyroid adenoma, the mean half-time for disappearance of PTH in vivo in five hyperparathyroid patients was 3.3 min.
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PMID:Performance and diagnostic application of a two-site immunoradiometric assay for parathyrin in serum. 277 25

The simultaneous occurrence of parathyroid carcinoma and other pathologic conditions of the parathyroid on a sporadic basis is extremely rare. Parathyroid exploration in an otherwise healthy 78-year-old woman with no underlying risk factors revealed synchronous right upper parathyroid adenoma and left upper parathyroid carcinoma. The patient's modest hypercalcemia (11.5 to 12.3 mg/dl) was seemingly at variance with remarkable parathormone elevations of 30 to 70 times normal.
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PMID:Synchronous occurrence of parathyroid carcinoma and adenoma in an elderly woman. 281 26

Hypercalcemia is an uncommon complication of childhood renal tumors. It is exclusively seen in infants 6 months of age or younger with malignant rhabdoid tumor of the kidney (MRTK) or congenital mesoblastic nephroma (CMN). Secretion of parathormone or prostaglandin E2 by the tumor cells is responsible for the hypercalcemia in most of these patients. Bone metastasis has been notably absent in these patients, and the hypercalcemia completely resolves with the removal of the tumor. Hypercalcemia in itself probably does not have any prognostic significance; however, it may serve as a tumor marker in some patients. Early recognition and effective management of this complication may prevent the acute life-threatening as well as the longstanding complications of this serious metabolic disorder.
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PMID:Hypercalcemia in childhood renal tumors. 282 81

This new bioassay for parathyrin (PTH) in plasma (bio-PTH) combines immunoextraction on affinity columns [goat anti-hPTH (1-44) conjugated to Sepharose 4B] and a receptor assay involving an osteosarcoma cell line. The mean extraction efficacy ranges from 87% (as determined with immunopurified 125I-labeled PTH) to 62% for hPTH bioactivity. The assay is standardized with synthetic hPTH (1-84) and can detect as little as 0.9 pmol/L of PTH in 2 mL of plasma. In 100 healthy adults, the 95% reference interval for bio-PTH was less than 0.9 to 6.1 pmol/L (median, 2.0 pmol/L). In 185 patients with surgically confirmed hyperparathyroidism, bio-PTH concentrations ranged from 1.0 to greater than 120 pmol/L (median, 12.9 pmol/L); 80% of values were greater than 6.1 pmol/L. In 50 patients with both preoperative and postoperative determinations, the mean (+/--SD) concentrations of calcium in serum were 113 +/- 10 and 89 +/- 6 mg/L, respectively; the median bio-PTH concentrations were 13.6 and 2.0 pmol/L, respectively. In 22 patients with nonparathyroid-mediated hypercalcemia, the concentration of bio-PTH ranged from less than 0.9 to 5.3 pmol/L (median, 1.8 pmol/L). This bio-PTH assay is slightly less sensitive than our GP235 immunoreactive PTH (iPTH) immunoassay for detecting hyperparathyroidism (Clin Chem 1982;28:69-74); however, the bioassay is more specific and detected some cases missed by the iPTH assay. Overall, 95% of the hyperparathyroid patients had an increased test result for either the bio-PTH or the iPTH assay.
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PMID:Bioassay of parathyrin: analytical characteristics and clinical performance in patients with hypercalcemia. 283 99

A case of prostatic carcinoma with the cellular patterns of an adenocarcinoma and carcinoid tumor is reported. The tumor contained ultrastructural dense core neuroendocrine granules, and immunoperoxidase staining revealed prostatic acid phosphatase, prostatic-specific antigen, chromogranin, neuron-specific enolase, serotonin, adrenocorticotrophic hormone (ACTH), somatostatin, parathormone, calcitonin, bombesin, and glucagon but no insulin. The patient had exhibited hypercalcemia that may have been related to hormone production by the tumor. The literature on the endocrine aspect of the prostate and its tumor is reviewed.
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PMID:Prostatic carcinoma with endocrine features. A report of a neoplasm containing multiple immunoreactive hormonal substances. 289 Dec 93

Sixty-one consecutive patients were examined to determine the current mode of presentation of primary hyperparathyroidism (pHPT). Of these patients, 37.7% were asymptomatic, and the initial indication of pHPT was hypercalcemia, which was found unexpectedly on biochemical screening of the serum in elderly patients. Hypertension was twice as common among patients with pHPT as in the general population (36.1%). The next most common presentations were urinary calculi (18%) and mental depression (18%). The most useful discriminant laboratory tests were serum calcium, phosphorus, chloride, and parathormone (PTH). The calculated coefficient of correlation of PTH to land weight was high (r = 0.571, p less than 0.001). There was very significant correlation between PTH and seriousness of bone disease (r = 0.620, p less than 0.001). After parathyroidectomy, 3.3% of patients remained hypercalcemic, 93% were normocalcemic, and 1.6% were hypocalcemic.
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PMID:Clinical and biochemical features in primary hyperparathyroidism. 291 78

Clodronate (dichlormethylene diphosphonate) was administered to 21 patients with hypercalcemia due to malignant tumor. The drug was initially given intravenously, then orally. In 20 patients the serum calcium level had been reduced to the normal range within one week of the start of treatment (from 3.3 +/- 0.5 mmol/l to 2.4 +/- 0.3 mmol/l). With oral administration there was a renewed rise in calcium levels in some patients, which had to be treated with higher oral doses or intravenous administration. Parallel with the reduction in calcium levels there was an improvement in the originally impaired renal function. The serum level of intact parathormone(1-84) and 1.25-dihydroxy-vitamin-D3 (calcitriol) rose significantly from usually lowered initial levels. There was a non-linear inverse correlation between parathormone and calcium. No side effects were noted, even after long-term administration.
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PMID:[Treatment of tumor hypercalcemia with clodronate. Effect on parathormone and calcitriol]. 295 79


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