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

We evaluated the effect of pulse oral calcitriol (4 micrograms three times weekly for 6 months) on parathyroid function in nine CAPD patients with hyperparathyroidism refractory to conventional low-dose oral calcitriol. Zero calcium peritoneal solutions were used to prevent the development of hypercalcaemia. The peritoneal loss of calcium increased from 168 +/- 40 to 417 +/- 48 mg/day using zero calcium solutions. Pulse oral calcitriol resulted in a significant decrease in PTH (from 617 +/- 272 to 382 +/- 299 pg/ml) by the 15th day of therapy, while serum iCa did not change from baseline. During the first month of therapy the mean PTH levels remained significantly reduced compared to baseline, thereafter PTH increased in four of nine patients. Hyperphosphataemia was not satisfactorily controlled in four patients, despite large amounts of binders used; seven of nine patients developed hypercalcaemia and required either the substitution of calcium acetate for calcium carbonate or reduction of calcitriol dose. Three patients showed a progressive increase in PTH. In conclusion our data suggest that in most CAPD patients with severe hyperparathyroidism oral calcitriol pulse therapy is not effective in maintaining a permanent suppression in PTH levels.
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PMID:High-dose oral calcitriol and zero calcium peritoneal solutions in CAPD patients with refractory secondary hyperparathyroidism. 770 73

Hyperphosphataemia plays a key role in the pathogenesis of renal osteodystrophy, and phosphate-binding agents are required in many chronic dialysis patients. Aluminium hydroxide and calcium carbonate are well-established phosphate binders, but their use is associated with toxicity or poor efficacy. Calcium acetate is known to be a potent phosphate binder, and has recently been used successfully in chronic dialysis patients. In this randomized cross-over trial in 31 chronic haemodialysis patients, equimolar doses of calcium acetate and calcium carbonate were administered for 6 weeks each. Compliance was estimated from tablet counts, and biochemical parameters were measured at the end of each treatment period. Of the 31 patients 23 completed both treatment arms; of the remainder, three withdrew due to adverse symptoms, hypercalcaemia necessitated treatment withdrawal in two, and three died. Non-compliance was significantly higher with acetate (18.3% tablets not taken) than with carbonate (8.7%). Serum phosphate was significantly lower after treatment with acetate (1.51 mmol/l) than with carbonate (1.80), as was the Ca x PO4 product (3.59 vs 4.18 respectively) and PTH (17.8 vs 25.4 pmol/l respectively). Serum calcium was significantly higher after acetate therapy (2.40 vs 2.32 mmol/l). No significant difference was found for sodium, potassium, bicarbonate, urea, creatinine, and haemoglobin. This study confirms that the treatment of hyperphosphataemia is more effective with calcium acetate than with calcium carbonate. For the first time an associated beneficial effect on secondary hyperparathyroidism has also been demonstrated. Patient tolerability of calcium acetate was considerably poorer, probably due in part to tablet formulation and bulkiness, as well as possible direct gastrointestinal effects of the acetate salt.
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PMID:Calcium acetate versus calcium carbonate as phosphate-binding agents in chronic haemodialysis. 780 Feb 11

A 24 year old patient with epigastric pain, polyuria, polydipsia and hypercalcemia was admitted to the hospital. Besides the frequent causes of hypercalcemia such as primary hyperparathyroidism and malignancy-related hypercalcemia we had to consider sarcoidosis because of massive splenomegaly. The interstitial lung disease shown on x-ray films of the chest, the epithelioid granulomas in lung tissue and the increased ACE confirmed the diagnosis of sarcoidosis. Hypercalcemia is found in less than 5% of all cases with sarcoidosis. After treatment with steroids, diphosphonates and diuretics all symptoms and the hypercalcemia improved.
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PMID:[Polyuria, polydipsia]. 780 Oct 19

We report a case of hypercalcaemic crisis due to sarcoidosis in a 15-year-old boy. The clinical suspicion of sarcoidosis was confirmed by a liver biopsy. At admission serum calcium, 1,25(OH)2 and ACE were elevated and iPTH was suppressed. The levels of serum total and ionized calcium, iPTH, ACE, 1,25(OH)2 and 25-OH were followed and chest X-ray and pulmonary function tests were performed during systemic steroid treatment. The clinical condition improved during treatment and the paraclinical measurements normalised within 5 weeks. The mechanism whereby hypercalcaemia occurs in childhood sarcoidosis is clarified.
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PMID:Childhood sarcoidosis presenting with hypercalcaemic crisis. 780 1

In vitro, 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) induces differentiation of HL-60 cells and inhibits their proliferation as well as the proliferation of leukemic cells from patients. In vivo, the survival of mice challenged with syngeneic leukemic cells is enhanced by treatment with 1,25(OH)2D3. Patients treated with 1,25(OH)2D3 develop hypercalcemia at a serum level of 2 x 10(-10) mol/l which is a concentration too low to achieve an antileukemic effect in vitro. Several interesting vitamin D3 analogs have recently been developed. We initially examined the effect of 1,25(OH)2-16ene-23yne-19-nor-26,27-F6-D3 and 24a,26a,27a-tri-homo-22,24-diene-1-alpha,25-(OH)2-D3 on clonal growth and differentiation of HL-60 cells. Each of the analogs had comparable effects on clonal growth with 50% inhibition (ED50) at concentrations of 0.2-0.5 x 10(-9) M; 1,25(OH)2D3 was about 20- to 50-fold less active in inhibiting growth. Differentiation was determined by induction of superoxide production, as measured by nitroblue tetrazolium (NBT) reduction and by expression of a macrophage-specific enzyme (alpha napthyl acetate esterase (ANAE)). The 24a,26a,27a-tri-homo-22,24-diene-1-alpha,25-(OH)2-D3 and 1,25(OH)2-16ene-23yne-19-nor-26,27-F6-D3 were about 5- to 14-fold more potent than 1,25(OH)2D3. The hypercalcemia inducing side-effects of these analogs and three other previously identified, extremely potent vitamin D3 compounds, as well as 1,25(OH)2D3, were studied. The analogs were administered intraperitoneally every other day (qod) for 5 weeks; serum was collected weekly and Ca2+ measured by atomic absorption spectrophotometry. The highest tolerated dose of each analog leaving all mice alive was for 1,25(OH)2D3: 0.25 micrograms; 1,25(OH)2-24a,26a,27a-tri-homo-22,24-diene-D3: 0.25 micrograms; and 1,25(OH)2-16ene-23yne-19-nor-26,27-F6-D3: 0.0625 micrograms. Another hexafluoro compound with potent abilities to induce differentiation (1,25(OH)2-16ene-23yne-26,27-F6-D3) was very toxic, all mice died in the second week while receiving 0.0625 micrograms qod. Prior studies showed that the most potent compound in inducing differentiation of HL-60 was 1,25(OH)2-20-epi-D3; but it is very toxic as only one mouse survived a dose of > or = 0.0125 micrograms qod for 5 weeks. 1,25(OH)2-16ene-23yne-D3 is an extremely active inducer of differentiation but, on the other hand, it has low potential to produce hypercalcemia; mice maintained normal serum calcium levels even while receiving 2 micrograms qod for 5 weeks.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Vitamin D3 analogs: effect on leukemic clonal growth and differentiation, and on serum calcium levels. 783 19

Phosphate retention plays a major role in the pathogenesis of hyperparathyroidism at all stages of renal insufficiency. Dietary phosphate restriction is mandatory only for adults and is not advised for children because of the recommended diet allowance. Dietary restriction is usually not sufficient, and phosphate binders are almost always necessary when the glomerular filtration rate falls below 40 mL/min. Because long-term administration of aluminum phosphate binders is associated with risk of aluminum intoxication despite the use of so-called "safe doses", alternative phosphate binders should be used. Magnesium hydroxide and carbonate can be used only for dialysis patients because a low dialysate magnesium concentration is necessary to prevent the hazards of hypermagnesemia. Therefore, the major alternative is the use of alkaline salts of calcium. The most recently proposed salt, acetate, has a higher phosphate-binding capacity than carbonate but exposes patients to the same incidence of hypercalcemia despite the use of half the dose of elemental calcium. These salts should be taken with meals in order to complex more dietary phosphate and decrease calcium absorption and therefore the risk of hypercalcemia. Oral calcium alone, without 1 alpha OH-vitamin D3 derivatives, can prevent hyperphosphatemia and hyperparathyroidism in most uremic patients before dialysis and in about half of the patients dialyzed with a dialysate calcium of 1.5 to 1.65 mmol/L. 1 alpha OH-vitamin D3 derivatives, which increase intestinal absorption of phosphate, should be used only when hyperphosphatemia has been prevented by oral calcium and diet and when plasma parathyroid hormone levels increase above three times the upper limit of normal. To decrease hypercalcemic risk, patients should be given 1 alpha OH-vitamin D3 derivatives, preferably at night, as an intermittent bolus (intravenous or oral). In dialysis patients, the dialysate concentration of calcium may have to be further decreased in order to prevent hypercalcemia when high doses of oral calcium are necessary to control hyperphosphatemia.
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PMID:Management of hyperphosphatemia in patients with renal failure. 785 19

Parathyroid hormone-related protein (PTHrP) was discovered as a hypercalcemia-inducing product of malignant cells and has since been demonstrated to be a product of many tissues. Although it is robustly expressed in fetal lung, PTHrP expression has not been assigned to alveolar epithelial cells in adult lung. We have shown that PTHrP is expressed in the adult rat lung and by cultured rat alveolar type II epithelial cells with sensitive and specific immunoassays and immunohistochemical techniques. Immunoassay of cell extracts demonstrated that freshly isolated type II cells contained PTHrP (136 pg/10(7) cells), whereas freshly isolated alveolar macrophages and cultured macrophages did not express PTHrP. Cultured type II cells secreted PTHrP into medium, 202 +/- 11 fg PTHrP/micrograms cell protein in 24 h. Basal secretion remained stable up to 7 days in culture. Treatment with phorbol myristate acetate or 1-oleoyl-2-acetyl-sn-glycerol produced a dose-related, 2- to 4-fold increase in PTHrP secretion. However, forskolin, ionomycin, ATP, phenylephrine, capsaicin, and bradykinin had no effect. Thus, PTHrP secretion appeared to be regulated by a protein kinase C-dependent pathway. PTHrP could also be demonstrated in pulmonary lavage fluid. Although the function of PTHrP in the adult lung is unknown, it could involve control of cell growth and differentiation or control of surfactant lipid secretion. Further studies are necessary to elucidate the function of PTHrP in the lung.
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PMID:Alveolar epithelial cells express and secrete parathyroid hormone-related protein. 794 99

Recent in vitro and in vivo studies have shown that calcium acetate (CaAC) is a more effective phosphorus binder than, among other calcium salts, calcium carbonate (CaCO3). More efficient binding allows serum phosphorus to be controlled with a lower dose; moreover, less calcium seems to be absorbed when CaAC is used. These properties could reduce the incidence of hypercalcemia; however, in clinical practice few reports have compared these two calcium salts, and results disagree. We evaluated in a 24-week prospective cross-over study the clinical efficiency of CaCO3 and CaAC in 10 selected chronic hemodialysis patients. Only 7 patients completed the study period. The patients were randomly assigned to start treatment with one of the two calcium salts; after 12 weeks they shifted to the other treatment. Serum analytical tests included weekly control of calcium, phosphorus, and alkaline phosphatase. PTH values (intact molecule) were obtained initially and at the end of every study period. The same good control of the phosphorus level (4.79 +/- 0.6 vs. 4.94 +/- 0.8 mg/dl) was obtained with CaAC (mean doses 4.1 +/- 0.3 g/day) as with CaCO3 (mean doses 4.01 +/- 0.8 g/day). The mean serum calcium levels were similar (10.36 +/- 0.5 vs. 10.20 +/- 0.5 mg/dl). The dose of elemental calcium administered was significantly less with CaAC (957 +/- 83 mg/day) than with CaCO3 (1,590 +/- 317 mg/day). However, the incidence of hypercalcemia (Ca > 11 mg/dl) was similar during the two treatment periods (13% with CaAC vs. 14% with CaCO3). Also the incidence of Ca x P products 765 was comparable (9.5 vs. 11.9%).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Calcium acetate versus calcium carbonate for the control of serum phosphorus in hemodialysis patients. 797 79

Three different dialysis procedures have been investigated and compared with respect to the efficacy of aluminium elimination in intoxicated dialysis patients. For this purpose ten patients with increased serum aluminium have been treated for two months with the chelator DFO. The effect of DFO on the aluminium clearance has been investigated. In spite of difficult conditions during studies due to an unexpected cumulation of severe adverse effects of DFO, some statements given here may be of value for the care of hemodialysis patients: 1. Both, the commonly used cuprophan filters as well as the newer highly permeable dialysis membranes like the polysulfone membrane used in our study, permit a steady but low elimination of aluminium during a dialysis session without significant difference in efficacy. A prerequisite, however, is a very low level of aluminium in the dialysate. 2. DFO induces a dose-dependent mobilization of aluminium accumulated in the tissue. The level of plasma aluminium increases distinctly, dialysable aluminium-DFO complexes are produced, and marked amounts of aluminium can thus be eliminated by the use of DFO. 3. IF DFO is used, even the economical cuprophan membrane CF1511 may lead to a satisfactory elimination rate of aluminium. Equal increase of elimination rate is achieved whether the Cuprophan membrane CF1511 is combined with the hemoperfusion filter Alukart or the highly permeable polysulfone membrane F60 is used alone. This is of importance particularly in cases of severe intoxication with aluminium. The polysulfon dialysator may be preferred to conventional membranes combined with hemoperfusion because of the simpler handling. 4. In order to prevent accumulation of aluminium in dialysis patients, besides the use of dialysates poor in aluminium, phosphate binders containing aluminium should be avoided completely if possible. They may be replaced by the two phosphate binders calcium carbonate and calcium acetate and a diet poor in phosphates. The use of aluminium-containing phosphate-binders should be restricted to exceptional cases such as patients with hypercalcemia, severe intolerance of calcium-containing phosphate-binders or patients with hyperphosphatemia that cannot be treated otherwise. 5. Finally, regular controls of plasma aluminium levels are mandatory in dialysed patients. In cases with an increase over 50 micrograms/l and positive DFO test, DFO treatment should be initiated. Low doses of 10 mg/kg body weight DFO per week are actually in use for those cases.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:[Aluminum poisoning in dialysis patients--diagnosis and therapy]. 802 59

Intermittent bolus administration of calcitriol--i.e., 1,25-dihydroxycholecalciferol or 1,25-(OH)2D3--is highly efficacious in dialysis patients. In experimental studies, intermittent administration of calcitriol is superior to continuous administration in suppressing preproparathyroid hormone (PTH) mRNA and circulating PTH concentrations. In a randomized, prospective, open multicenter trial 45 dialysis patients with elevated 1,84-iPTH (> or = 20 pmol/l, normal 1-6 pmol/l) levels were randomly allocated to daily administration of 0.75 microgram calcitriol (continuous) or twice weekly administration (intermittent); the two protocols provided an identical total weekly doses of 5.25 micrograms calcitriol. Patients were dialyzed with a dialysate Ca concentration of 1.75 mmol/l and had oral CaCO3 or Ca acetate. 1,84-iPTH (immunoradiometric assay) and serum Ca and Pi levels were measured weekly. At the beginning of the study, the median 1,84-iPTH value was 37 pmol/l (range 20-115) in the intermittent versus 36 pmol/l (range 21-72) in the continuous calcitriol group. After 2 weeks, the median 1,84-iPTH level was 18.5 pmol/l (range 1.4-106) versus 18 pmol/l (range 1.2-48). After 12 weeks, 11 of 21 of the patients in the intermittent and 18 of 24 patients in the continuous group had reached the treatment goal, i.e., 1,84-iPTH < or = 10 pmol/l without hypercalcemia or hyperphosphatemia. There were seven episodes of hypercalcemia (> 2.7 mmol/l) in the intermittent versus two in the continuous group; the mean peak Ca level was 2.8 mmol/l (range 2.76-3.0) versus 2.9 mmol/l (range 2.74-3.06). There were 21 versus 17 episodes, respectively, of hyperphosphatemia (> 2.2 mmol/l).
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PMID:Comparison of intermittent and continuous oral administration of calcitriol in dialysis patients: a randomized prospective trial. 805 67


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