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)

Secondary hyperparathyroidism (HP) is well known complication of long-term uremia. CAPD patients show a peculiar behaviour due to loss of vitamin D metabolites through peritoneum. Severe degrees of hyperparathyroidism may require parathyroidectomy in order to achieve appropriate control. Recently, the possibility of controlling this situation with high oral doses of calcitriol has been communicated. The purpose of this study is to evaluate the effect of this agent on hyperparathyroidism in CAPD patients. Two different groups were constituted according to the length of time on dialysis when HP was detected. All of the patients had i-PTH serum levels five times higher than the normal values (50 pg/ml). During a six month period the daily dose of oral calcitriol was increased in order to achieve a reduction in i-PTH level. The results after this period showed a significant reduction in i-PTH levels (614 +/- 378 to 241 +/- 80 pg/ml) with an average increase in oral calcitriol from 0.16 +/- 0.1 to 0.67 +/- 0.4 with no significant changes in serum calcium or phosphorus. The group with HP at start of dialysis achieved these effects easier and with lower doses of calcitriol. We conclude that moderately high doses of oral calcitriol control secondary hyperparathyroidism in CAPD patients without hypercalcemia.
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PMID:Secondary hyperparathyroidism in CAPD patients: its suppressibility with high doses of calcitriol. 198 16

The cause of hypercalcemia in familial benign hypercalcemia (FBH; also called familial hypocalciuric hypercalcemia) is unclear, although it is PTH dependent. It is also uncertain how plasma PTH levels are related to the severity of biochemical abnormalities in FBH. Because the PTH-related peptide (PTHrP) has many PTH-like actions, it might have a role in the hypercalcemia of FBH. Thus, we studied 29 patients with FBH from 11 families, 29 age- and sex-matched controls, and 42 patients with primary hyperparathyroidism (1 degree HPT), measuring PTH with a highly sensitive two-site immunochemiluminometric assay and the hypercalcemic tumor factor PTH-related peptide (PTHrP) with an extraction/concentration RIA. Plasma PTH values were elevated in 86% of 1 degree HPT patients (36 of 42), but in only 20% of FBH patients, (6 of 29). Plasma PTHrP was elevated in 1 FBH patient, and the group mean value was normal. Plasma PTH was positively correlated with calcium (Ca) in 1 degree HPT (r = 0.66; P less than 0.0001) and in FBH (r = 0.53; P less than 0.004), but the slopes of the regressions were markedly different: 1 degree HPT, 6.72; FBH, 1.61 (P less than 0.0001). There was a negative correlation between PTH and phosphorus (P) in 1 degree HPT (r = -0.39; P less than 0.01) and in FBH (r = -0.41; P less than 0.03), but, again, the slopes differed greatly: 1 degree HPT, -6.57; FBH, -1.95 (P less than 0.0001). There were no correlations between PTHrP and Ca or between PTH and PTHrP. The sums and products of PTH and PTHrP were not better correlated with Ca than PTH alone. Thus, PTH values are lower at given Ca and P levels in patients with FBH than in those with 1 degree HPT, suggesting that PTH is more effective in raising Ca and lowering P in FBH than in 1 degree HPT. The enigma of FBH remains: what molecular defect can simultaneously cause parathyroid cell insensitivity to Ca, enhanced renal tubular reabsorption of Ca, increased renal rejection of P, and enhanced or retained sensitivity to PTH?
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PMID:Plasma intact parathyroid hormone (PTH) and PTH-related peptide in familial benign hypercalcemia: greater responsiveness to endogenous PTH than in primary hyperparathyroidism. 199 10

Calcium acetate has many characteristics of an ideal phosphorus binder. It is a readily soluble salt that avidly binds phosphorus in vitro at pH 5 and above. One-dose/one-meal balance studies show it to be more potent than calcium carbonate or calcium citrate. We studied chronic (3-month) phosphorus binding with calcium acetate in 91 hyperphosphatemic dialysis patients at four different centers. All phosphorus binders were stopped for 2 weeks. Calcium acetate at an initial dose of 8.11 mmol (325 mg Ca2+) per meal was then used as the only phosphorus binder. Dose was adjusted to attempt control of predialysis phosphorus level less than 1.78 mmol/L (5.5 mg/100 mL). Final calcium acetate dose was 14.6 mmol (586 mg) Ca2+ per meal. Sixteen patients developed mild transient hypercalcemia (mean, 2.84 mmol/L [11.4 mg/dL]. Initial phosphorus values in mmol/L (mg/dL) were 2.39 (7.4); at 1 month, 1.91 (5.9); and at 3 months, 1.68 (5.2). Initial calcium values in mmol/L (mg/dL) were 2.22 (8.9); at 1 month, 2.37 (9.5); and at 3 months, 2.42 (9.7). Initial aluminum values in mumol/L (micrograms/L) were 2.99 (80.7); and at 3 months were 2.54 (68.4). Initial C-terminal parathyroid hormone (C-PTH) values in ng/mL were 14.6; at 1 month, 11.9; and at 3 months, 13.2. Sixty-nine patients then entered a double-blind study. Phosphorus binders were stopped for 1 week. Calcium acetate (at a dose established in a prior study) or placebo was then administered for 2 weeks. Next, patients were crossed to the opposite regimen for 2 weeks. Initial phosphorus was 2.36 mmol/L (7.3 mg/100 mL) and calcium 2.22 mmol/L (8.9 mg/100 mL).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Calcium acetate control of serum phosphorus in hemodialysis patients. 202 56

In order to assess the correlation between menopause and osteoporosis, both in pathogenetic and therapeutical terms, a study was carried out in four comparable group of patients at Department B of the Institute of Gynaecology and Obstetrics at the University of Turin. Patients were divided as follows: 24 patents affected by evident osteoporosis, 39 patients with the first symptoms of osteoporosis, 27 with hypercalcemia and 33 healthy controls. The following tests were performed in all subjects: serum assay of androstenedione, estrone, 17-beta-estradiol, PTH, calcium, phosphorus, alkaline phosphatase and creatinine. Laboratory tests were repeated monthly in all patients and control subjects. Dual chromatic ray bone densitometry was performed in all patients at the start and end of treatment. With regard to therapy, each group was subdivided into two equal subgroups which were treated with carbocalcitonin or conjugated estrogens. From the findings, it is clear that there is a non-significant difference between serum levels of androstenedione, estrone and estradiol in the three groups examined and control subjects. Although the possibility that the fall in steroid hormones might contribute to bone load cannot be excluded, it is not possible to demonstrate that this is the most important factor in the pathogenesis of osteoporosis given that many women do not develop osteoporotic symptoms after menopause. In addition, in therapeutic terms, all bone density parameters considered in patient osteoporosis improved after therapy.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Comparative analysis of therapeutic effects of carbocalcitonin and and conjugated estrogens in post-menopausal osteoporosis]. 208 96

We studied the effects of calciopenia and phosphopenia on longitudinal growth, skeletal mineralization, and development of rickets in young Sprague-Dawley rats. At an age of 21 days, two experimental groups were given diets containing 0.02% calcium or 0.02% phosphorus; otherwise the diets were nutritionally adequate. After 7, 14, and 21 days, five animals from each group were randomly chosen. The animals were anaesthetized and blood samples were drawn for analysis of calcium, phosphorus, and immunoreactive parathyroid hormone, whereupon the animals were killed. Length, weight, and specific weight of the left femur were measured. After 28 days on the respective diet the remaining animals were killed and one proximal tibia from each animal was processed for light microscopy and subjected to stereological analysis. Both experimental groups developed progressive growth retardation, more so the phosphate-depleted group. The calciopenic animals developed severe hypocalcaemia and secondary hyperparathyroidism, whereas the phosphate-depleted animals, in spite of marked secondary hypercalcaemia, had unaltered levels of immunoreactive parathyroid hormone. By 28 days both experimental groups displayed rachitic changes, more pronounced in the phosphate-depleted animals. This paper provides quantitative data demonstrating that calciopenia per se may cause rickets in young rats, but that the rachitic changes in this condition are less severe, and the growth pattern different from those in phosphate depletion.
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PMID:Rickets induced by calcium or phosphate depletion. 220 84

The appropriate use of phosphate binders, calcium supplements and especially calcitriol therapy has significantly decreased the incidence of overt secondary hyperparathyroidism in dialysis patients. Nevertheless some patients may still need parathyroidectomy, especially in the event of severe clinical signs and symptoms such as persistent hypercalcemia, pruritus, calcifilaxis, or extensive extra-skeletal calcification. Since aluminum-induced bone disease may resemble hyperparathyroidism in dialysis patients, whenever parathyroidectomy is contemplated the diagnosis of secondary hyperparathyroidism must be firmly established. Thus, a bone biopsy is mandatory prior to parathyroidectomy. It is our experience that once the patient goes to surgery the most important factor in the surgical approach is the presence of a skilled surgeon who has extensive experience in parathyroid gland surgery. The data comparing subtotal parathyroidectomy with total parathyroidectomy and autotransplantation are similar. The most important shortcoming is the lack of long-term follow-up. Recently, new data by several investigators has been advanced reintroducing total parathyroidectomy. Long-term observations in patients who despite total parathyroidectomy still have normal PTH levels are of special interest. In addition, long-term follow-up of these patients has shown that normal plasma calcium and phosphorus levels may be maintained without the use of Vitamin D; this occurred in the presence of active mineralization. However, our major objection to this procedure is the risk of aluminum-induced bone disease. At the present time we feel that the relative high incidence of recurrent hyperparathyroidism following subtotal parathyroidectomy is a reasonable trade off for the risk of aluminum bone disease which may develop in absence of PTH.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Parathyroidectomy in chronic renal failure: indications, surgical approach and the use of calcitriol. 221 49

Four young milk-fed calves were fitted with catheters chronically implanted in the mesenteric, portal and hepatic veins and in the hepatic artery, and with electromagnetic blood flow probes in the portal vein and hepatic artery, allowing continuous measurement of IGF-I hepatic production. According to a latin square design, these calves received iv mesenteric infusion of calcium (Ca2+; 5 mg/kg) or synthetic salmon calcitonin (sCT; 1 microgram/kg), or synthetic bovine parathyroid hormone (1-34) (bPTH; 1 microgram/kg), or solvent alone (1.2 ml/kg). Ca2+, sCT or bPTH had no significant effect on portal vein or hepatic artery blood flow. Hypercalcemia observed following Ca2+ infusion did not significantly modify hepatic IGF-I production. sCT decreased plasma Ca2+, inorganic phosphorus and GH concentrations and hepatic IGF-I production. bPTH induced a slight hypercalcemia and hypophosphatemia. It had no significant effect on plasma GH concentration, but increased significantly hepatic IGF-I production. Thus, the anabolic effects of PTH on bone may be partly mediated through an increase in hepatic IGF-I production.
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PMID:Parathyroid hormone and calcitonin may modulate hepatic IGF-I production in calves. 223 93

Little notice has been paid in the surgical literature to problems with psychoeffective lithium, which by interfering with adenylate cyclase affects thyroid and parathyroid function, causing hypercalcemia, hyperparathyroidism, and hypothyroidism. Seven patients with lithiumogenic hyperparathyroidism occurring after years of lithium therapy underwent treatment and manifested osteoporosis (n = 2), hypertension (n = 2), nephrolithiasis (n = 1), coma (n = 1), rising hypercalcemia (n = 1), goitrous myxedema (n = 4), nephrogenic diabetes insipidus (n = 2), renal failure (n = 2), and hyperlipidemia (n = 1). Disease-directed parathyroidectomy (without morbidity) was curative. Unique laboratory findings included normal serum phosphorus and reduced urinary calcium and cyclic adenosine monophosphate values. Three separate cases of thyroid carcinoma after long-term lithium therapy were also treated, being preceded by myxedema (n = 2) and concurrent with hyperparathyroidism (n = 1). There has been only one previous report of lithium-associated thyroid carcinoma. All patients taking lithium should undergo surveillance for thyroid and parathyroid dysfunction and neoplasia, and appropriate surgical and medical treatment should be considered in each situation. Although hyperparathyroidism may be reversible with lithium discontinuance, such therapy may be obligatory for patient well-being, thus dictating parathyroidectomy.
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PMID:Lithiumogenic disorders of the thyroid and parathyroid glands as surgical disease. 224 24

Phosphorus is a well-known modulator of renal 1 alpha-hydroxylase activity. In early and moderate renal failure it is proposed that dietary Pi reduction ameliorates secondary hyperparathyroidism through increased circulating levels of calcitriol (i.e, 1 alpha, 25-dihydroxycholecalciferol). To gain further insight into the mechanisms by which a low-Pi diet ameliorates secondary hyperparathyroidism in advanced renal insufficiency, studies were performed in five dogs before and 6 mo after the induction of uremia by 5/6 nephrectomy. Glomerular filtration rate decreased from 69.0 +/- 2.3 to 10.5 +/- 0.5 ml/min, immunoreactive parathyroid hormone (irPTH) increased from 66.0 +/- 8.8 to 321.0 +/- 46 pg/ml, and calcitriol decreased from 39.0 +/- 10.4 to 27.0 +/- 6.2 pg/ml. Thereafter, dietary Pi was decreased gradually every 2 wk from 0.95% to 0.6, 0.45, and 0.3%, respectively. Dietary Ca was reduced from 1.6 to 0.6% to prevent development of hypercalcemia. Ionized Ca (ICa) decreased from 5.4 +/- 0.04 to 5.2 +/- 0.05 mg/dl (P less than 0.02), and plasma Pi decreased from 6.3 +/- 0.7 to 4.7 +/- 0.2 mg/dl (P less than 0.05). Calcitriol remained low (23.3 +/- 4.7 pg/ml). However, irPTH gradually decreased from 321.0 +/- 46.0 to 94.7 +/- 22.9 pg/ml (P less than 0.005). These studies indicate that a decrease in dietary Pi from 0.95 to 0.3% suppressed irPTH by approximately 70%. Reduction of irPTH was observed in the absence of a concomitant increase in levels of ICa or calcitriol. These studies suggest that reduction in dietary Pi in advanced renal insufficiency improves secondary hyperparathyroidism by a mechanism that is independent of the levels of calcitriol or plasma ICa.
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PMID:Phosphorus restriction reverses hyperparathyroidism in uremia independent of changes in calcium and calcitriol. 239 69

The occurrence of acetylation phenotype has been studied in 76 patients with untreated hyperthyroidism. In 23 of these patients having the "fast" and in 42 having the "slow" acetylation phenotype the selected parameters of calcium-phosphate metabolism have been determined before, during and after propranolol therapy lasting six days. Propranolol was administered at a dose of 160 milligrams daily. A significant decrease in the blood serum level of calcium and urinary calcium excretion following propranolol administration was found only in patients with hypercalcemia and hypercalciuria. On the other hand, a significant decrease in the urinary excretion of hydroxyproline was observed in all the patients with hyperthyroidism treated with propranolol. The effect of propranolol on the measured parameters of calcium-phosphorus metabolism was similar in hyperthyroid patients with both "fast" and "slow" acetylation phenotypes, what suggests that it does not depend on the N-acetyltransferase activity.
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PMID:[Acetylation phenotype and the changes in selected indicators of calcium-phosphate metabolism in patients with hyperthyroidism treated with propranolol]. 248 31


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