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)

Freshwater catfish, Heteropneustes fossilis, were injected daily intraperitoneally either with vehicle (0.05 ml of 95% ethanol/100 g body wt) or vitamin D3 (50 I.U./100 g body wt) and maintained in artificial fresh water, calcium-rich fresh water, or calcium-deficient fresh water for 10 days. The specimens were sacrificed on Days 1, 3, 5, and 10 after initiation of the experiment. The blood samples were collected on these intervals and serum calcium and inorganic phosphate levels were analyzed. Vitamin D3 induced hypercalcemia and hyperphosphatemia in the freshwater catfish, H. fossilis. These effects of vitamin D3 are not dependent upon the calcium concentration of the different ambient media used in this study.
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PMID:Effect of vitamin D3 administration on the serum calcium and inorganic phosphate levels of the freshwater catfish, Heteropneustes fossilis, maintained in artificial fresh water, calcium-rich fresh water, and calcium-deficient fresh water. 132 May 83

We studied the effect of converting 100 established CAPD patients from aluminium- to calcium-based phosphate binders. After a follow-up of 1 year only 60% of patients remained on calcium carbonate. Hypercalcaemia was the major problem, with more than 40% of patients having a serum calcium in excess of 3.0 mmol/l. Several patients required hospitalization for symptomatic hypercalcaemia. Hypercalcaemia was more common in patients with normal serum parathyroid hormone concentrations (65 versus 25%, P less than 0.01). Serum phosphate control was better prior to commencing calcium carbonate when patients were treated with aluminium phosphate binders mean 1.71 +/- 0.15 mmol/l (SEM) than at the time of maximum serum calcium concentration, 1.81 +/- 0.25, P less than 0.05. This study does not confirm the findings of others, which have suggested that calcium carbonate is a safe and effective phosphate binder for patients with end-stage renal failure.
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PMID:Audit of the use of calcium carbonate as a phosphate binder in 100 patients treated with continuous ambulatory peritoneal dialysis. 838 46

This study evaluates the effect of intravenous calcitriol on parathyroid function and ionized calcium-PTH sigmoidal curve obtained during low- and high-calcium haemodialysis in 10 patients with osteitis fibrosa whose secondary hyperparathyroidism was refractory to conventional therapy. After 4 months of intravenous calcitriol, serum ionized calcium increased from 1.28 +/- 0.08 to 1.37 +/- 0.11 mmol/l (P less than 0.001), serum phosphate from 1.54 +/- 0.18 to 1.79 +/- 0.4 mmol/l (P NS), serum calcitriol from 16.7 +/- 9.9 to 34.3 +/- 6.4 pg/ml (P less than 0.001), while alkaline phosphatase decreased from 366 +/- 340 to 226 +/- 180 IU/l (P less than 0.05), osteocalcin from 46.4 +/- 20 to 34.5 +/- 15.3 ng/ml (P less than 0.05), and basal intact PTH from 1069 +/- 700 to 305 +/- 270 (P less than 0.01). Basal PTH started to decrease after 1 month of treatment prior to the increase in the ionized calcium. Because of hypercalcaemia the dialysate calcium was decreased from 1.75 to 1.5 mmol/l in three of five patients on haemodialysis, and calcium-containing solutions were replaced by calcium-free fluids in four of five patients on haemodiafiltration. Calcitriol dose, at the first month of therapy was 5.6 +/- 0.8 micrograms/week, but it was successively decreased because of hypercalcaemia to a final dose of 3.6 +/- 1.3 micrograms/week. After intravenous calcitriol the ionized calcium-PTH sigmoidal curve shifted to the left and downward. Maximally stimulated PTH and maximally inhibited PTH obtained during low- and high-calcium dialysis significantly decreased, as well as the ratio of basal PTH/PTHmax and the set point of calcium.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Effect of chronic intravenous calcitriol on parathyroid function and set point of calcium in dialysis patients with refractory secondary hyperparathyroidism. 132 15

Increased 1,25-dihydroxyvitamin D levels and decreased basal and calcium-stimulated calcitonin serum levels have been found in children with Williams-Beuren syndrome (WBS). To determine whether isolated or combined disturbances of secretion or action of the calcium-regulating hormones may cause the tendency to hypercalcemia in WBS, we investigated several aspects of calcium metabolism in 27 normocalcemic children and adults, aged 2 to 47 years, with WBS. With the exception of slightly decreased 25-hydroxyvitamin D and slightly increased calcitonin in serum, all measured basal indexes of calcium and bone metabolism, including the serum levels of intact parathyroid hormone and 1,25-dihydroxyvitamin D, were comparable to control values. Total and extractable calcitonin, the latter representing the monomeric and biologically important form of the hormone, showed the same relative increase after a low-dose calcium infusion in patients and control subjects, indicating a normal capacity of the calcitonin-producing C cells of the thyroid gland in WBS. Furthermore, exogenous parathyroid hormone induced a normal response of 1,25-dihydroxyvitamin D, cyclic adenosine monophosphate, and phosphate excretion, indicating a normal response of the renal 25-hydroxyvitamin D-1 alpha-hydroxylase and the renal receptor-adenylate cyclase system to parathyroid hormone. These findings suggest that neither deficient calcitonin secretion nor increased renal sensitivity to parathyroid hormone is a feature of WBS in normocalcemic patients.
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PMID:Calcium metabolism in Williams-Beuren syndrome. 835 37

The mineralization process was investigated in the aortic wall of hypercalcemic rabbits. The elevated calcium level in serum was induced by intramuscular injection of vitamin D3. The animals were killed at different times of the experiment (max. 246 d). The freeze-dried tissue homogenates were used for elemental composition studies by means of proton induced X-ray emission (PIXE) and atomic absorption spectroscopy. The structural information was obtained from infrared (IR) and X-ray diffraction (XRD) spectra. Moreover, the ascending part of the aortic arch was separated and used for micro-PIXE (PIXE in combination with proton microprobe) and histochemical examinations. It was found that hypercalcemia (blood serum Ca content elevated by about 20%) induced calcification of the aortic wall. The mineral phase within the aortic wall consisted of Ca-P salts. The Ca/P ratio continuously increased during the experiment and approached 2 after 246 d of the vitamin D3 treatment. The IR and XRD studies made possible the identification of the complex phase composition of the samples. The hydroxyapatite crystals were detected after 196 days, however, in earlier phases of the experiment, amorphous calcium phosphate, dicalcium phosphate dihydrate and octacalcium phosphate were also observed. On the basis of the data obtained, the mechanism of the precipitation and growth of inorganic deposits in the tunica media of the aortic wall was discussed.
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PMID:Calcification of the aortic wall in hypercalcemic rabbits. 133 14

Oral calcium carbonate is an effective phosphate binder in dialysis patients. Its use minimizes aluminium intake, and by maintaining a high-normal serum ionized calcium, suppresses serum parathyroid hormone levels. However, the dose required to control hyperphosphataemia may cause hypercalcaemia. We performed prospective studies in 50 previously undialysed patients starting CAPD (28 study group, 22 control group). Calcium carbonate was the only phosphate binder used in the study group which utilized a low calcium PD fluid (calcium 1.25 mmol/l), whilst the control group used standard PD solution (calcium 1.75 mmol/l) with calcium carbonate plus aluminium hydroxide phosphate binders as clinically indicated. The study group was able to take larger doses of oral calcium carbonate with no increase in episodes of hypercalcaemia compared to the control group. There were no instances of hypocalcaemia in any patient using the low-calcium dialysis fluid. Phosphate control was better in the study group, despite the additional use of aluminium-containing phosphate binders by some patients in the control group. Serum aluminium levels in the study group were maintained at < 11.5 mumol/l, but increased significantly in the control group from 3 months onward. Mean serum parathyroid hormone in the study group declined significantly from baseline values over the first 6 months, and remained at the lower level. Bone histology showed a tendency towards improvement over the 12 months, in terms of osteoclast numbers and activity. We conclude that using dialysis fluid with a reduced calcium concentration in compliant, well-monitored patients is safe.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Low-calcium dialysis fluid and oral calcium carbonate in CAPD. A method of controlling hyperphosphataemia whilst minimizing aluminium exposure and hypercalcaemia. 133 63

Twelve patients (median age 44.5 years) on CAPD, who had previously used a dialysate calcium concentration of 1.75 mmol/l (for a median time of 11.5 months) were started on a low calcium dialysate (LCD) with a calcium concentration of 1.25 mmol/l and followed up for 24 weeks. During the first eight weeks, no changes in the doses of oral phosphate binders were made and serum ionized calcium decreased from 1.30 +/- 0.02 (mean +/- SE) mmol/l to 1.17 +/- 0.02 (p < 0.0001) and serum PTH (1-84) rose from 68 (median, range 16-397) ng/l to 147 (70-449, p = 0.005). After week 8, increasing doses of calcium carbonate were used to achieve target calcium levels of 1.20-1.30 mmol/l. No aluminum-containing binders were used. Calcium carbonate doses were increased from 2.3 (median, range 0.75-12) g/d to 6.8 (3.8-15.0, p = 0.0004) and serum phosphorus concentrations decreased from 2.00 mmol/l (median, range 1.25-2.67) at 8 weeks to 1.61 (1.18-2.39) at 24 weeks (p = 0.023). Serum intact PTH(1-84) values remained elevated despite the gradually increasing serum calcium concentrations. Hypercalcemia was recorded in 20/36 (56%) of blood samples during a period of four weeks before the start of LCD, and such episodes were observed in 15/89 (17%) of samples (p < 0.001) on LCD during the period when calcium carbonate doses were increased. It is concluded that on LCD 1) the number of episodes of hypercalcemia was markedly reduced, 2) higher calcium carbonate doses could be used, and thus 3) the control of serum phosphorus improved.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:CAPD with low calcium dialysate and calcium carbonate: results of a 24-week study. 136 22

We studied calcium (Ca), magnesium (Mg) mass transfer (MT) in 10 and lactate balance in 5 CAPD patients using standard dialysis solution [(ST) (Ca 1.75 mmol/l; Mg 0.75 mmol/l; lactate 35 mmol/l)] and with reduced Ca/Mg, high lactate solution [(LC) (1.25 mmol/l; 0.25 mmol/l; 40 mmol/l respectively)]. Exchanges were performed with 1.36% and 3.86% glucose solutions. MT was calculated as mmol/exchange. Ca MT was +0.96 and +0.39 with ST 1.36% and 3.86% glucose respectively. Serum ionised Ca (iCa++) levels were less than fluid Ca during these exchanges. With LC 1.36% glucose it was -0.66 when ICa++ was more than dialysate Ca, but +0.66 when iCa++ was less than dialysate Ca. Ca MT was negative with LC 3.86% glucose irrespective of iCa++ levels. All patients were hypermagnesaemic (mean 1.24 mmol/l. Mg MT was +0.21 and -0.04 with ST 1.36% and 3.86% glucose respectively and -0.62 and -1.13 with LC 1.36% and 3.86% glucose respectively. The difference between mean lactate gain and bicarbonate loss was less (-0.4) during exchange with LC 1.36% glucose. Mean plasma TCo2 and plasma pH did not differ between ST and LC solutions. We conclude that reduced Ca/Mg, high lactate solutions should reduce hypercalcaemia/magnesaemia and maintain a better acid base balance in CAPD patients who may require Ca/Mg containing phosphate binders.
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PMID:Calcium, magnesium mass transfer and lactate balance study in CAPD patients with reduced calcium/magnesium and high lactate dialysis fluid. 136 24

Theoretical and clinical studies suggest that reduction of PD fluid calcium to 1.25 mmol/liter allows administration of larger doses of calcium carbonate, improves phosphate control and obviates the need for aluminum gels in most CAPD patients, without increasing hypercalcemia or hyperparathyroidism. Hypermagnesemia can also be avoided by reducing PD fluid magnesium concentration to 0.25 mmol/liter. Although glucose is a safe, effective an cheap osmotic agent, it provides a short duration of ultrafiltration, and contributes to significant metabolic abnormalities. Amino acids and glucose polymer are potential alternatives to glucose, and early clinical studies are encouraging. The unphysiological concentration of lactate in PD fluids has been shown to have pathological consequences, and undoubtedly bicarbonate would be a preferable buffer. Manufacturing techniques are being developed to produce such a fluid. A fluid containing bicarbonate and the peptide glycylglycine (30:10 mmol/liter) gives a stable buffer with a pH of 7.35, but has only undergone animal studies so far. Glucose solutions have deleterious effects on the peritoneal membrane, particularly during episodes of severe peritonitis, and the high osmolality is toxic to peritoneal host defense cells. Prompt treatment of peritonitis, early removal of the catheter where necessary, and minimization of glucose exposure, may do much to lengthen the dialysis life of the peritoneum.
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PMID:Improved solutions for peritoneal dialysis: physiological calcium solutions, osmotic agents and buffers. 140 67

In order to prevent aluminum toxicity induced by the association of aluminum phosphate binder with 1 alpha(OH) vitamin D3 derivatives and the use of deferoxamine with its own hazards to diagnose and treat this toxicity, we have shown in 1982 that it was possible to replace the iatrogenic association of aluminum phosphate binder with 1 alpha OH vitamin D derivatives by oral calcium carbonate taken with the meals in order to bind phosphate and correct the negative calcium balance. This led to the disappearance of the crippling aluminic osteomalacia and adynamic bone diseases in our center. The effectiveness of CaCO3 without 1 alpha(OH)D3 derivatives in the control of hyperparathyroidism in dialysis patients has been proven by the appearance in four patients of our dialysis population of an histological idiopathic adynamic bone disease associated with relative hypoparathyroidism, and by the finding that more than 50% of our dialysis population treated by this sole treatment have plasma concentration of intact PTH below twice the upper limit of normal (that is, the threshold above which only significant histological osteitis fibrosa is observed). Besides the compliance problem, the limit of CaCO3 is the occurrence of hypercalcemia which occurs in about 8% of the measurements. Since calcium acetate binds twice as much phosphate for the same dose of elemental calcium as CaCO3, its use has been recommended. However, clinical experience has shown that in spite of the fact that half the dose of calcium element given as acetate does actually control predialysis plasma phosphate as well as CaCO3, the incidence of hypercalcemia is not decreased, probably because calcium availability at the alkaline pH of the intestine is much greater with Ca acetate. When hypercalcemia is frequent (and not explained by autonomized hyperparathyroidism, adynamic bone disease, overtreatment with vitamin D, granulomatosis or neoplasia) it is necessary either to decrease the dose of calcium and complete the necessary binding of phosphate by adding small doses of Mg(OH)2 or Mg carbonate, provided the dialysate Mg is decreased to 0.2 to 0.35 mmol/liter to prevent hypermagnesemia or to decrease the dialysate calcium (DCa) concentration. The decrease of DCa can be made either just when hypercalcemia occurs or on a systemic basis according to the amount of CaCO3 used and to the necessity of associating 1 alpha(OH) vitamin D3 derivatives.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Use of alkaline calcium salts as phosphate binder in uremic patients. 140 82


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