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

A link between hyperparathyroidism and the growth of hematopoietic stem cells is suggested by this report of a parathyroid carcinoma with polycythemia vera. A 56-year-old white woman presented with splenomegaly, a palpable neck mass and hypercalcemia, recurrent six years after resection of a parathyroid tumor. She had pancytosis with a subnormal serum concentration of erythropoietin. Radiographs showed subperiosteal erosions an dosteopenia. Nephrocalcinosis was absent. Bone biopsy showed a decreased cortical width with many intracortical osteoclasts. The cancellous bone area remained normal, but the osteoid area/bone area, osteoblast perimeter and osteoclast perimeter were increased. At surgery, a parathyroid carcinoma was found in the same location operated on previously. As in two other reported cases, postoperative improvement in the hypercalcemia was associated with remission of the blood dyscrasia. A novel finding in this case is that when the hypercalcemia eventually recurred, it was again accompanied by pancytosis. With bisphosphonate therapy, the serum intact parathyroid hormone level increased in response to a decrease in the ionized calcium level, indicating that the cancer was not autonomous. This case suggests that in the presence of the ionized hypercalcemia, the parathyroid tumor may have produced or induced production of a growth factor that can stimulate pancytosis. The differential diagnosis of polycythemia and hypercalcemia should be expanded to include parathyroid tumors in addition to hepatic, adrenal, renal, and ovarian neoplasms.
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PMID:Parathyroid carcinoma associated with polycythemia vera. 179 72

A retrospective study of 68 children with increased medullary echogenicity on renal ultrasound (US) examination showed nephrocalcinosis to be present in 42 patients. The cause was believed to be iatrogenic in 30 and noniatrogenic in 12. Furosemide therapy was responsible for 11 of the cases of iatrogenic nephrocalcinosis and vitamin D therapy for the remaining iatrogenic cases. Noniatrogenic nephrocalcinosis was seen with hypercalcemia, hypercalciuria, renal tubular acidosis and dystrophic calcification following renal tubular necrosis. In 26 patients, medullary deposits of urates or proteins, medullary fibrosis, or vascular congestion (due to a variety of diseases) appeared to account for the finding. These possibilities should be added to the differential diagnosis of hyperechoic renal pyramids when nephrocalcinosis is unlikely.
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PMID:Echogenic renal pyramids in children. 184 53

The synergistic interaction of fructose and magnesium (Mg) deficiency on kidney calcification was compared in male and female rats. Male and female weanling rats were divided into four dietary groups: fructose or starch, with or without Mg. Rats were fed their respective diets for 9 weeks, and 24 h urine was collected to measure urinary output, pH, Mg, calcium (Ca), and oxalic acid. Rats were fasted overnight. After decapitation, blood was collected immediately, and kidneys were removed to determine their Mg and Ca content. Dietary fructose significantly increased kidney Ca in female rats fed deficient or adequate Mg diet and in male rats fed Mg-deficient diet only; the greatest kidney calcification occurred in female rats fed Mg-deficient diet (P less than 0.0001). Even in starch groups female rats fed the Mg-deficient diet showed some kidney Ca accumulation. The synergistic interaction of fructose and magnesium deficiency on nephrocalcinosis was significantly greater in female than in male rats. Low urinary output, optimal pH 6.8 for calcium phosphate precipitation, hypercalcaemia, hypercalciuria, hypomagnesuria, and low ratio of urinary Mg to Ca may independently or multifactorially contribute to nephrocalcinosis. The possible mechanism of this interaction is discussed.
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PMID:Dietary fructose produces greater nephrocalcinosis in female than in male magnesium-deficient rats. 191 Oct 97

One hundred and eleven stable renal transplant patients were investigated, using sensitive methods, for the effect of hypercalcaemia on renal function and for the presence of nephrocalcinosis. Twenty-five patients (22.5%) were hypercalcaemic but this had no effect on renal function. Nephrocalcinosis was detected in a small percentage of patients using ultrasonography and computed tomography.
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PMID:Investigation--including computed tomography and ultrasonography--of the renal transplant patient with hypercalcaemia. 194 98

Although hypercalcaemia is considered to be aetiological factor of nephrocalcinosis and uroliths formation, its effect on the major salivary glands, where lithiasis is frequent, has not been studied enough. The purpose of this project was the parallel histologic study of the effect of experimentally induced hypercalcaemia on the kidney and the major salivary glands of the rat. Temporary hypercalcaemia was induced in 17 females rates after 8 daily intraperitoneal doses 1.5 ml of 10% calcium gluconate. After the fixation of the tissues in 4% formaldehyde containing 1% CaCl2, serial sections were stained with haematoxylin and eosin and Von Kossa's method for calcified deposits. In the kidneys calcified deposits were observed in the cytoplasm of the cells of the proximal convoluted tubules, in the basement membrane, and their lumen. The major salivary glands were normal. Calcified deposits were not observed in the glandular parenchyma either in the lumina. The results suggest that during hypercalcaemia the transcellular transport of the calcium continue to be under the normal influence of the autonomic nervous system, preventing the formation of calcified deposits.
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PMID:[The effect of the hypercalcaemia on the major salivary glands of the rat]. 194 96

An association between homozygous familial hypercholesterolemia (FH) and nephrocalcinosis has not, to our knowledge, been previously reported. Evaluation in 10 cases of homozygous FH revealed evidence of nephrocalcinosis in 7 cases. Fine, uniform calcifications in the renal papillae were demonstrated by renal ultrasound or CT. Renal papillary necrosis was demonstrated by intravenous pyelogram in one case. No renal function impairment was noted in these seven patients. There was no evidence of hypercalcemia. These findings may have implications for the use of a potentially nephrotoxic drug for the treatment of this disease--in particular, when an immunosuppressive agent is required following liver transplantation.
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PMID:Nephrocalcinosis in homozygous familial hypercholesterolemia: ultrasound and CT findings. 198 76

Severe hypercalcemia is a medical emergency requiring urgent treatment. It most commonly is caused by malignant tumors, as in the case study, but can also be caused by advanced hyperparathyroidism or high serum levels of vitamin D. The patient described in the case study shows clinical evidence of volume contraction due to hypercalcemia-related anorexia and vomiting. His elevated serum concentrations of urea nitrogen and creatinine reflect intravascular volume depletion and hypercalcemia-induced reduction of renal perfusion. He is also likely to have irreversible renal damage as a result of nephrocalcinosis. His central nervous system depression is most likely a result of hypercalcemia, but other central nervous system disorders such as cerebral metastases should be considered. Appropriate treatment would include intravenous fluids to correct volume depletion, dilute extracellular fluid calcium, and promote renal calcium excretion. Before waiting for the effects of volume expansion, the first dose of an inhibitor of bone resorption should be given. The agent of choice now (this may change when second-generation bisphosphonates become available) is plicamycin. Etidronate is a reasonable second choice. Because both drugs require at least 48 hours before their hypocalcemic action is manifest, calcitonin could be used to accelerate the rate of decline of the serum calcium. As the patient becomes more alert, weight-bearing and ambulation should be encouraged. With this combination of therapeutic modalities, this patient's serum calcium level should be corrected within 3 to 5 days. Intermittent injections of mithramycin or etidronate could be given on an outpatient basis approximately once a week in order to maintain the serum calcium within the normal range. One of the most important aspects of treatment in hypercalcemic patients is eradication of the underlying disease, which usually calls for specific antitumor therapy, including chemotherapy, radiation therapy, or surgery. Most of the agents currently available for the correction of hypercalcemia have cumulative toxicities or are only transiently effective and, therefore, their use should be considered a temporizing measure until specific treatment directed at the primary disease takes effect.
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PMID:Management of severe hypercalcemia. 200 13

A total of 79 infants born at less than 32 weeks' gestation were studied with serial renal ultrasound scans to assess the incidence of nephrocalcinosis. Twenty one infants developed renal calcification giving an overall incidence of 26.6% in the study group. Affected infants were significantly smaller (mean (SD) birth weight 940 (323) g) and significantly less mature (mean (SD) gestation 26.9 (1.9) weeks). In 17 patients the calcification was represented by hyperechogenic renal pyramids alone, and in four patients renal calculi were demonstrated. Factors associated with renal calcification included hypophosphataemia, hypercalcaemia, hypercreatininaemia, and prolonged oxygen requirement during the first month of life. Multivariate analysis showed that the strongest clinical indicator of calcification was duration of oxygen treatment. Infants who still required oxygen treatment at 28 days had a 62% chance of developing renal calcification.
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PMID:The incidence of renal calcification in preterm infants. 192 31

In this brief review of various hypercalcemic disorders and the likelihood of renal calculus formation, it is clearly evident that renal calculi occur much more often in hyperparathyroidism than in the other hypercalcemic states. Dystrophic calcification and nephrocalcinosis are common to all of the hypercalcemic disorders, including hyperparathyroidism, when the hypercalcemia is marked and the limit of solubility of calcium and phosphate in serum is approached. Interestingly, in sarcoidosis there are calcium oxalate crystals in variously distributed sarcoid granuloma, and the renal calculi are composed of calcium oxalate. By contrast, in hyperparathyroidism, the calculi composed of calcium phosphate predominate. This indicates a subtle and as yet undefined alteration in oxalate metabolism in sarcoidosis. An increase in urine pH occurs in hyperparathyroidism, and this enhances formation of crystalline calcium phosphate. However, the striking disparity between the frequency of calculus formation in hyperparathyroidism and that in other hypercalcemic disorders, several of which may be of relatively long duration, suggests that there indeed may be increased promoters of crystal formation in the urine of hyperparathyroid patients.
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PMID:Urinary calculi in hypercalcemic states. 208 14

Chronic hypercalcemia (HC) induced by dihydrotachysterol (DHT) is associated with a nephrogenic concentrating defect. The purpose of the present study is to assess the effects of HC on thick ascending limb (TAL) NaCl reabsorption in vivo by use of micro stop-flow technique. Feeding DHT (4.25 mg/kg diet) to rats was associated with an increase in plasma [Ca] within 24 h from 2.21 +/- 0.049 to 2.71 +/- 0.047 mM (P less than 0.001), which remained elevated during the 7-day period of study. Ambient plasma arginine vasopressin (AVP) in polydipsic HC rats was 3.10 +/- 0.605 pg/ml, a value not different from that measured in pair-fed control rats (1.82 +/- 0.260 pg/ml). A urine-concentrating defect developed after 3 days and occurred without nephrocalcinosis or reduced glomerular filtration rate (GFR). The estimated TAL [NaCl] after all stop-flow periods in HC rats did not decrease to the same extent as in controls. The rate constant of NaCl reabsorption derived from linear regression analysis of the ln[NaCl] vs. time for 0-15 s was significantly reduced by 25% in the HC nephrons. In addition, the minimum [NaCl] established after 30-60 s of contact time increased by 36% in HC nephrons. These data provide evidence that reduced TAL NaCl reabsorption, and not reduced GFR, nephrocalcinosis, or deficient AVP, contributes to the presence of a renal concentrating defect in DHT-induced chronic HC.
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PMID:Vitamin D-induced chronic hypercalcemia inhibits thick ascending limb NaCl reabsorption in vivo. 211 38


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