Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0020437 (hypercalcemia)
 10,293 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Metal ions have various and significant effects on the skeletal system. Aluminum accumulation in renal dialysis patients causes osteomalacia, while gallium is an effective therapeutic agent for treating the hypercalcemia accompanying certain malignancies. Using in-vitro systems that stimulate in-vivo mineralization, the authors have investigated the physical-chemical mechanisms of the actions of aluminum and gallium and report some of their findings.
 ...
PMID:The effect of aluminum and gallium ions on the mineralization process. 255 41

With increasing recognition of problems regarding the use of aluminum hydroxide as a phosphate binder, calcium carbonate has become the medication of choice. Use of calcium has, however, frequently been associated with development of hypercalcemia. At this institution, calcium carbonate powder as a phosphate binder, examination of its efficacy, and the frequency of hypercalcemia with its use were of great interest. Calcium carbonate powder (CalCarb-HD, 2.4 gms elemental calcium/packet) (CalCarb-HD, Lafayette Pharmacal Inc., Fort Worth, TX) was used in the study. Twenty-one end-stage renal disease (ESRD) patients (17 hemodialysis and 4 chronic ambulatory peritoneal dialysis) were chosen and converted from their previous binder (primarily, calcium carbonate tablets) to calcium powder. The dosage was adjusted to keep phosphorus levels at 3.5 to 5.5 mg/dl and calcium less than 11.5 mg/dl. At 2 months, the average calcium level in the 16 patients remaining in the study was 9.2 mg/dl, and the average phosphorus level was 5.2 mg/dl with an average calcium dose of 1.4 packets/day. By 7 months, the 8 patients remaining in the study had an average calcium level of 9.9 mg/dl with an average phosphorus level of 5.5 mg/dl; average calcium dose was 1.8 packets/day. Total episodes of hypercalcemia (calcium greater than 11.5 mg/dl) were two. Calcium carbonate powder appears to be an effective phosphate binder in the ESRD population. The relatively few episodes of hypercalcemia may be related to possible enhanced bioavailability of the compound secondary to its powdered form.
 ...
PMID:Calcium carbonate powder as a phosphate binder. 259 73

Many investigators have shown that calcium carbonate (CaCO3) is an effective phosphate binder which also prevents the potential disabling effects of aluminum (Al) accumulation. However, hypercalcemia may develop in a substantial numbers of patients. Thus, to control serum phosphate (PO4) and prevent hypercalcemia, we performed studies in 21 patients on maintenance hemodialysis in which, in addition to the oral administration of CaCO3, the concentration of calcium (Ca) in the dialysate was reduced from 3.25 to 2.5 mEq/liter. The studies were divided in three periods: I. control, on Al-binders (one month); II. no Al-binders (one month); III. CaCO3 (seven months). Blood was obtained three times/week before dialysis for the first five months of the study and once a week for the remaining four months. During the control period, the mean serum calcium was 8.86 +/- 0.08 mg/dl. The value decreased to 8.65 +/- 0.07 mg/dl when phosphate binders containing aluminum were discontinued, and increased to 9.19 +/- 0.07 mg/dl (P less than 0.001 compared to period II) during oral supplementation with calcium carbonate. The mean serum phosphorus was 5.03 +/- 0.07 mg/dl during the control period, and increased to 7.29 +/- 0.91 mg/dl (P less than 0.001) after phosphate binders were discontinued. It decreased to 4.95 +/- 0.06 mg/dl (P less than 0.001) with the administration of calcium carbonate. During CaCO3 administration, serum Al decreased from 64.2 +/- 8.5 to 37.1 +/- 3.6 and 25.1 +/- 3.0 micrograms/liter (P less than 0.001) at three and seven months, respectively. Serum parathyroid hormone (PTH) decreased by 20%.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Long-term effects of calcium carbonate and 2.5 mEq/liter calcium dialysate on mineral metabolism. 261 97

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.
 ...
PMID:[Replacement of aluminum-containing phosphate binders by calcium and magnesium carbonates in long-term hemodialysis]. 270 34

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.
 ...
PMID:Hypercalcemia in patients with advanced chronic renal failure not yet requiring dialysis. 275 79

Since dialysis solutions in CAPD are now nearly aluminum free, the only source for elevated aluminum levels are aluminum-containing phosphate binders. Elimination with CAPD is insufficient to prevent aluminum accumulation. Therefore, we investigated a phosphate binder consisting of calcium alginate, a natural polyuronic acid, containing 100 mg calcium/g substance in 14 patients on CAPD over a period of one year. The patients had previously been treated with aluminum-containing phosphate binders for a period of 24.3 +/- 21.3 months. During a period of 3 weeks before changing to the new phosphate binder the mean (+/- SD) serum phosphorus concentration was 1.8 +/- 0.4 mmol/l, while at the end of one year of treatment with calcium alginate the concentration was 1.6 +/- 0.4 mmol/l. In order to lower serum phosphorus to this level, it was necessary to increase the mean (+/- SD) amount of calcium alginate from 6.9 +/- 1.3 g per day at the beginning of the study to 8.3 +/- 2.1 g per day at the end. The mean (+/- SD) serum calcium concentration did not change throughout the study period. Serum levels of alkaline phosphatase, 1.25 (OH)2 vitamin D3, and intact parathyroid hormone did not change as well. The mean (+/- SD) serum aluminum level declined from 36.0 +/- 20 to 14.0 +/- 11.3 micrograms/l after 6 months (p less than 0.001). In conclusion, calcium alginate is a good alternative to aluminum-containing phosphate binders and to phosphate binders on a calcium base as it does not lead to hypercalcemia. It prevents aluminum intoxication and has no serious side effects.
 ...
PMID:Calcium alginate, an aluminum-free phosphate binder, in patients on CAPD. 276 87

Aluminum (Al) intoxication is a condition that reponds well to treatment with desferrioxamine (DFO) in humans with renal failure. The present study deals with the effect of DFO administration on the Al concentrations of different tissues and on bone histology in rats with renal failure, loaded with Al. After the Al-loading there is an important increase of Al in serum, (1,103 +/- 355 micrograms/l) (mean +/- SD), bone (116 +/- 14 mg/kg), liver 238 +/- 78 mg/kg) and muscle (8.5 +/- 4.1 mg/kg). Urinary Al excretion averages 287 +/- 68 micrograms/d. Serum biochemistry reveals renal failure and hypercalcemia (3.5 +/- 0.3 mmol/l). The rats were subsequently treated by either placebo or 150 mg DFO per week. The placebo-treated rats show a spontaneous decrease of serum Ca and Al and of liver and muscle Al content. The DFO-treated rats had, compared to the placebo-treated animals, an increase of urinary Al excretion and lower Al concentration in bone and brain. Bone histology after Al-loading shows an increase in osteoid measurement when compared with non-Al-loaded animals with renal failure: osteoid volume 25.6 +/- 13.3% versus 5.0 +/- 2.9% and osteoid index 63.6 +/- 22.1% versus 27.3 +/- 15.3% in Al-loaded and non-Al-loaded animals, respectively. In addition, the aluminon stain covered 89.7 +/- 3.8% of the bone trabeculae of Al-loaded rats. Under placebo treatment the osteoid measurements increase, reflecting a worsening of Al-induced bone disease. DFO therapy did not result in a significant change of the different measurements of bone histology, despite the decrease of aluminon staining to 67.7 +/- 13.7%.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:The effect of desferrioxamine on tissue aluminum concentration and bone histology in aluminum-loaded rats with renal failure. 298 Aug 1

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.
 ...
PMID:Renal osteodystrophy and aluminum bone disease in CAPD patients. 305 62

The efficacy and safety of calcium carbonate as a phosphate binder was evaluated in 20 patients on chronic hemodialysis who had previously received aluminum hydroxide. During the control period the patients were on aluminum hydroxide and calcitriol therapy and had plasma phosphorus levels less than 6 mg/dL (4.95 +/- 0.8 mg/dL). Aluminum hydroxide was then discontinued and no phosphate binder was prescribed for 1 month. Every patient developed hyperphosphatemia so that calcium carbonate treatment was begun and calcitriol dose was adjusted in relation to plasma calcium changes. After 24 months of calcium carbonate therapy, plasma phosphorus was 4.85 +/- 0.7 mg/dL, using a daily dose of calcium carbonate of 2.57 +/- 1.3 g (range, 1 to 6 g). The daily dose per patient of calcitriol was not different from that prescribed during the control period, but in five patients calcitriol was permanently withdrawn for hypercalcemia. At the end of the study plasma calcium, magnesium, bicarbonate, alkaline phosphatase, and parathyroid hormone values were unchanged in comparison with the control period, whereas a significant reduction in plasma aluminum and plasma aluminum increase induced by deferoxamine infusion was observed. The frequency of hypercalcemic and hyperphosphatemic episodes during the last 12 months of calcium carbonate therapy (6.2% and 16.6%, respectively) was not different from that observed during the 12 months on aluminum hydroxide therapy preceding the control period (4.5% and 14.7%, respectively). It was concluded that calcium carbonate is effective in the control of hyperphosphatemia and secondary hyperparathyroidism in patients on chronic hemodialysis and that the incidence of hypercalcemia is low when the daily dosage is less than 6 g.
 ...
PMID:Efficacy and safety of long-term treatment with calcium carbonate as a phosphate binder. 314 60

The effects of a small dose of calcitriol (less than or equal to 0.50 micrograms/day) on parathyroid and renal function, bone histomorphometry, and aluminum (Al) metabolism were studied in a randomized double blind study of 30 patients with predialysis chronic renal failure. The patients were followed at least monthly for 8 months. Serum Al levels were measured, and transiliac bone biopsies, double labeled with tetracycline, were obtained at both the beginning and end of the 8-month treatment period. Serum calcium and ionized calcium concentrations increased in the treatment group, and the calcitriol dosage had to be reduced in 8 patients at least once because of hypercalcemia. Calcitriol treatment did not significantly influence either serum A1 levels or the presence of stainable Al in bone. Serum PTH, urinary cAMP excretion, and bone resorption indices decreased in the treatment group, indicating suppression of parathyroid hyperfunction. Throughout the study renal function decreased at a similar rate in both groups, suggesting that calcitriol treatment had no depressive effect on renal function. We conclude that a low dose of calcitriol may be used to preserve or even restore bone metabolism in patients with predialysis chronic renal failure if serum calcium is closely followed and hypercalcemia promptly treated.
 ...
PMID:Low dose calcitriol versus placebo in patients with predialysis chronic renal failure. 318 64


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>