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

Although conventional therapy (pharmacologic doses of vitamin D and phosphorus supplementation) is usually successful in healing the rachitic bone lesion in patients with X-linked hypophosphatemic rickets, it does not heal the coexistent osteomalacia. Because serum 1,25-dihydroxyvitamin D levels are inappropriately low in these patients and high calcitriol concentrations may be required to heal the osteomalacia, we chose to treat five affected subjects with high doses of calcitriol (68.2 +/- 10.0 ng/kg total body weight/d) and supplemental phosphorus (1-2 g/d) performing metabolic studies and bone biopsies before and after 5-8 mo of this therapy in each individual. Of these five patients, three (aged 13, 13, and 19 yr) were receiving conventional treatment at the inception of the study and therefore showed base-line serum phosphorus concentrations within the normal range. The remaining two untreated patients (aged 2 and 37 yr) displayed characteristic hypophosphatemia before calcitriol therapy. All five patients demonstrated serum calcitriol levels in the low normal range (22.5 +/- 3.2 pg/ml), impaired renal phosphorus conservation (tubular maximum for the reabsorption of phosphate per deciliter of glomerular filtrate, 2.13 +/- 0.20 mg/dl), and osteomalacia on bone biopsy (relative osteoid volume, 14.4 +/- 1.7%; mean osteoid seam width, 27.7 +/- 3.7 micron; mineral apposition rate, 0.46 +/- 0.12 micron/d). On high doses of calcitriol, serum 1,25-dihydroxyvitamin D levels rose into the supraphysiologic range (74.1 +/- 3.8 pg/ml) with an associated increment in the serum phosphorus concentration (2.82 +/- 0.19 to 3.78 +/- 0.32 mg/dl) and improvement of the renal tubular maximum for phosphate reabsorption (3.17 +/- 0.22 mg/dl). The serum calcium rose in each patient while the immunoactive parathyroid hormone concentration measured by three different assays remained within the normal range. Most importantly, repeat bone biopsies showed that high doses of calcitriol and phosphorus supplements had reversed the mineralization defect in all patients (mineral apposition rate, 0.88 +/- 0.04 micron/d) and consequently reduced parameters of bone osteoid content to normal (relative osteoid volume, 4.1 +/- 0.7%; mean osteoid seam width, 11.0 +/- 1.0 micron). Complications (hypercalcemia and hypercalciuria) ensued in four of these five patients within 1-17 mo of documented bone healing, necessitating reduction of calcitriol doses to a mean of 1.6 +/- 0.2 micrograms/d (28 +/- 4 ng/kg ideal body weight per day). At follow-up bone biopsy, these four subjects continued to manifest normal bone mineralization dynamics (mineral apposition rate, 0.88 +/-0.10 micrometer/d) on reduced doses of 1.25-dihydroxyvitamin D with phosphorus supplements (2 g/d) for a mean of 21.3 +/- 1.3 mo after bone healing was first documented. Static histomorphometric parameters also remained normal (relative osteoid volume, 1.5 +/- 0.4%; mean osteoid seam width, 13.5 +/- 0.8 micrometer). These data indicate that administration of supraphysiologic amounts of calcitriol, in conjunction with oral phosphorus, results in complete healing of vitamin D resistant osteomalacia in patients with X-linked hypophosphatemic rickets. Although complications predictably require calcitriol dose reductions once healing is achieved, continued bone healing can be maintained for up to 1 yr with lower doses of 1,25-dihydroxyvitamin D and continued phosphorus supplementation.
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PMID:Healing of bone disease in X-linked hypophosphatemic rickets/osteomalacia. Induction and maintenance with phosphorus and calcitriol. 383 45

Quantitative bone histology, biochemistry and height velocities were studied in 18 children suffering from chronic renal failure. Eight received calcitriol, 7 ergocalciferol and 3, though alloted to a treatment group, failed to comply with therapy. A histochemical stain for aluminum showed heavy deposition at the calcification front in 3 patients; 2, in the calcitriol group had severe osteomalacia which worsened during treatment, and 1 in the ergocalciferol group had osteomalacia which did not improve. One had never undergone hemodialysis. Bone histology improved markedly in the remaining 12 patients, whichever vitamin D preparation was used; it was unchanged in 3 non-compliant children. Plasma calcium levels rose while parathyroid hormone and alkaline phosphatase levels fell following both treatments, and were unchanged in non-compliant children. Hypercalcemia occurred more frequently following calcitriol therapy (11 episodes) than following ergocalciferol therapy (3 episodes). Height velocities, studied in 11 children, increased in 5 (3 on ergocalciferol and 2 on calcitriol) and were unchanged in 6 (1 on ergocalciferol, 5 on calcitriol). Improved bone histology did not correlate with increase in height velocity. As ergocalciferol and calcitriol had similar therapeutic effects and as side-effects were more common with calcitriol, it is concluded that calcitriol provides no advantage over ergocalciferol in the treatment of renal bone disease in children.
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PMID:Treatment of childhood renal osteodystrophy with calcitriol or ergocalciferol. 387 85

Dialysis osteomalacia is characterized by distinctive, although not pathognomonic, clinical and biochemical features. Symptoms and signs may include musculoskeletal pain, arthralgias, proximal muscle weakness, and spontaneous fractures. Biochemical characteristics may be hypercalcemia and normal serum alkaline phosphatase activities. Vitamin D administration may induce early severe hypercalcemia. Plasma phosphate and immunoreactive parathyroid hormone concentrations may be at any level. Only bone histology allows to establish the diagnosis of dialysis osteomalacia with certainty. Diphosphonate bone scan, however, enables to distinguish between severe osteitis fibrosa and dialysis osteomalacia. The diagnostic value of desferrioxamine administration with subsequent measurement of plasma aluminium remains to be determined. The complex interactions existing between parathyroid hormone and aluminium are not yet fully understood.
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PMID:Dialysis osteomalacia: clinical aspects and physiopathological mechanisms. 391 57

In patients with severe chronic renal failure (SCRF), especially in those undergoing chronic dialysis, aluminium may accumulate in the body. The aluminium is derived from the dialysate and/or from orally-administered, aluminium-containing phosphate binders. Accumulation preferentially occurs in the bone causing aluminium-induced osteomalacia. The physiopathological mechanisms of the disease still have to be elucidated. It has been suggested that aluminium accumulates at the osteoid/calcified-bone boundary (OCBB) inhibiting the influx of calcium there, and also that aluminium directly suppresses the secretion of parathyroid hormone (PTH). A third factor inducing the mineralization defect may be the presence of aluminium within the mitochondria of the osteoblast. In accordance with these hypotheses, hypercalcemia and relatively low iPTH levels are frequently found in aluminium-induced osteomalacia. Histologic methods are essential for demonstrating the actual existence of aluminium-induced osteomalacia. A large bone biopsy is desirable. When the biopsy is not decalcified and embedded in plastic, excellent histologic pictures are obtained wherein mineralized and non-mineralized bone (i.e. osteoid) can be distinguished clearly. Furthermore, the un-decalcified sections can be stained for aluminium, iron or both, and they are suitable for evaluation of the bone marrow status. Several features, like irregularly distributed osteoid with variable thickness, a relatively low number of cubic osteoblasts, and the absence of marrow fibrosis, are suggestive of aluminium-induced osteomalacia. However, the latter can only be proven by histochemical methods, e.g. by the aluminon staining. The treatment of aluminium-induced osteomalacia is quite different from that of other types of renal bone disease.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Aluminium-induced osteomalacia in severe chronic renal failure (SCRF). 391 58

The physiopathology of metabolic bone disease described during long term total parenteral nutrition is poorly understood. We therefore prospectively assessed bone status of seven adult patients [mean age, 42 +/- 16 (SD) yr] treated with cyclic total parenteral nutrition for a period of 7 +/- 2 (SD) months. All patients had hypercalciuria (381 +/- 96 mg/day) associated with negative calcium balance in six of seven patients (-49 +/- 120 mg/day). A correlation was found (r = +0.74, P less than 0.01) between protein intake and calciuria. Two patients developed slight transient hypercalcemia. Serum magnesium and phosphate levels remained within the normal range. A high aluminum load due to the added phosphate solution (253 +/- 84 micrograms/day) was associated with increased serum aluminum levels (52 +/- 38 micrograms/liter). Normal serum levels of 25 hydroxyvitamin D (12 +/- 7 ng/ml) and low normal 1,25 dihydroxyvitamin D levels (21 +/- 8 pg/ml) were found. Serum PTH was normal in five and increased in two of the seven patients. However, in these two patients skeletal unresponsiveness to the action of PTH was found. A new histomorphometric picture of bone was observed; it consisted of a markedly reduced bone formation with subnormal osteoclastic activity leading to a low trabecular bone volume. No osteomalacia was found. The aluminum load may have played a role in these bone defects. The hypercalciuria with negative calcium balance was attributed to the cyclic amino-acid delivery during TPN.
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PMID:Multifactorial low remodeling bone disease during cyclic total parenteral nutrition. 391 65

Ten dialysis-treated patients with hypercalcemia (11.5 +/- 0.3 mg/dl, mean +/- SE) due to renal osteodystrophy were compared with 30 control dialysis-treated patients who were not hypercalcemic (9.5 +/- 0.1 mg/dl). The hypercalcemic patients were more disabled than the control patients. Fifty percent of the hypercalcemic patients and 37 percent of the control patients had a mineralization defect (p greater than 0.6). In the control group, intact parathyroid hormone level was significantly higher in patients with osteitis fibrosa than in those with osteomalacia (247 +/- 39 pg/ml versus 60 +/- 20 pg/ml, respectively, p less than 0.005) whereas in the hypercalcemic patients, parathyroid hormone measurements did not discriminate between these two types of bone disease. Osteomalacia was more severe and bone aluminum staining was stronger in the hypercalcemic patients than in the control patients (2.02 +/- 0.47 versus 0.35 +/- 0.11 mm/mm2 tissue area, p less than 0.001). The mean serum calcium level fell from 11.2 +/- 0.2 mg/dl to 10.5 +/- 0.3 mg/dl (p less than 0.01) in eight hypercalcemic patients treated with 24,25-dihydroxyvitamin D. It is concluded that hypercalcemia in patients undergoing dialysis is associated with an increase in bone aluminum level, and with more severe osteomalacia. Intact parathyroid hormone levels are useful for predicting bone histomorphometric parameters but only when hypercalcemia is not present. The drug, 24,25-dihydroxyvitamin D, was effective in lowering the serum calcium level.
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PMID:Spontaneous hypercalcemia in patients undergoing dialysis. Etiologic and therapeutic considerations. 396 41

27 patients on hemodialysis (dialysate aluminium less than 0.7 mumol/l for 2 years, and 2 mumol/l before) whose plasma Ca and PO4 were adequately controlled for already 6 months by high doses of CaCO3 alone (mean +/- SD: 9 +/- 5 g/day), were randomly divided into 2 groups, a control group (c group) which was kept on the same treatment, and a group in which CaCO3 was reduced to 3 g/day but in which plasma Ca was kept normal due to 1 alpha-OH-vitamin D3 administration (1 microgram/day at the beginning, 0.3 microgram/day after 6 months; 1 alpha group) whereas plasma phosphate was kept below 6.0 mg/dl because of Al(OH)3 (2.7-5 g/day). Initially, the 2 groups were comparable as regards the plasma concentrations of total and ionized Ca, phosphate, alkaline phosphatases, medium and C-terminal parathyroid hormone (PTH) and aluminium, but the control group had lower plasma 25-OH-vitamin D (25-OHD.) After 6 months, the same difference in plasma 25-OHD was found with comparable plasma concentrations of total and ionized calcium as well as of medium and C-terminal PTH (beta error 1%). However, plasma concentration of phosphate and the plasma Ca phosphate product, as well as the plasma aluminium were higher in the 1 alpha group whereas their PCO3H- was lower. Although the alkaline phosphatase values were not significantly different between the 2 groups, they increased only in the control group because of 1 patient who developed a vitamin-D-deficient osteomalacia (plasma 25-OHD 3 ng/ml), which was subsequently cured by physiological doses of 25-OHD3. The incidence of transient hypercalcemia (15 vs. 21 episodes) and worsening of soft tissue calcifications (3 in each group) was the same in the 2 groups.
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PMID:Comparison of 1 alpha-OH-vitamin D3 and high doses of calcium carbonate for the control of hyperparathyroidism and hyperaluminemia in patients on maintenance dialysis. 398 76

A patient with many symptoms and signs of primary hyperparathyroidism had hypocalcaemia when first seen. Bone section histology showed osteomalacia and osteitis fibrosa, and the hyperparathyroidism at this stage was considered to be secondary to osteomalacia with postgastrectomy steatorrhoea. On treatment with vitamin D (with disappearance of her bone pains and weakness) she developed hypercalcaemia. She regained her health after removal of a 6-g. parathyroid adenoma. Normal histology was shown in another parathyroid gland.We believe that the initial hypocalcaemia was due to vitamin-D deficiency, which produced ineffective hyperparathyroidism until it was corrected. A review of the few reports of patients with autonomous hyperparathyroidism with steatorrhoea and osteomalacia does not support the argument that these patients had "tertiary" disease. It suggests that most of them, like our patient, had primary hyperparathyroidism.
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PMID:Hypocalcaemic primary hyperparathyroidism. 541 47

In 16 patients with chronic renal failure and osteomalacia resistant to vitamin-D therapy, aluminium was demonstrated in bone biopsy specimens at the interface between thickened osteoid and calcified bone by means of both X-ray microanalysis and a specific histochemical stain. 14 patients also had hypercalcemia. It is suggested that this is due to the blocking by aluminium of additional calcium uptake into bone coupled with the availability of additional calcium from dialysis fluid and vitamin-D therapy. This study provides more aetiological evidence linking aluminium and the development of osteomalacia in chronic renal failure. Further, if hypercalcaemia develops in such patients it is important that aluminium toxicity be excluded as the cause to prevent unnecessary parathyroidectomy.
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PMID:Hypercalcaemic osteomalacia due to aluminium toxicity. 612 1

Diphosphonates were administered intravenously to 4 patients with myeloma-induced hypercalcaemia. All patients received EHDP 4.3 mg/kg/day for 3 to 8 days. One of them, whose hypercalcaemia recurred, was later treated with Cl 2 MDP 5 mg/kg i.v. for 8 days. In 2 patients EHDP infusions were followed by EHDP administered orally (5 mg/kg/d) for 3 weeks, after which transiliac bone biopsy was performed. In all patients calcemia fell from 130 +/- 14 to 99 +/- 4 mg/l at the end of the intravenous treatment, with parallel decrease in calciuria. Histomorphometric analysis of the bone biopsies showed few osteoclasts but massive infiltration with plasmocytes. In one case, EHDP probably induced a deficit in mineralization. Intravenous diphosphonates therefore proved to be rapidly effective in the treatment of hypercalcaemia due to malignancy. However prolonged administration of EHDP in high doses is not recommended, as it may result in osteomalacia.
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PMID:[Treatment of hypercalcemia of myelomatous origin with intravenous diphosphonates]. 622 88


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