Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.3.1 (alkaline phosphatase)
 47,916 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Rats were subjected to a two-stage subtotal nephrectomy or sham operation, and treated with aluminum (Al) or both aluminum and vitamin D3 metabolites for 5 weeks with a cumulative dose of 13.6 mg aluminum. Animals were injected with 3H-thymidine and 3H-proline. The following analyses were performed: quantitative histology of tibial metaphyses and cytomorphometric electron microscopy of osteoclasts, quantitative (ICP-spectroscopy) and qualitative determination (histochemical staining) of aluminum within organs, and serum biochemistry (Ca, P, Mg, vitamin D3 metabolites, alkaline phosphatase, urea). The following new facts of the aluminum-related bone disease became evident: (a) Application of aluminum to growing uremic rats induced rickets, whose major epiphyseal growth plate changes were 1 alpha,25(OH)2D3-dependent. Addition of 1 alpha,25(OH)2D3 prevented the formation of rachitic metaphysis, but failed to prevent osteoid accumulation on epiphyseal and metaphyseal trabecular surfaces. Moreover, calcitriol produced hyperosteoidosis and osteosclerosis in the same rats. Aluminum did not alter the function of osteoblasts, while osteoclasts seemed inactivated. (b) The development of rickets was associated with suppressed serum levels of 1,25(OH)2D3, reduced phosphorus level and the high content of aluminum in the bone, kidney, and liver. The addition of 24R,25(OH)2D3 markedly exaggerated the reduction of serum levels of calcitriol. We suggested that aluminum induces rickets in growing uremic rats, which consists of two components: vitamin D refractory osteomalacia and 1 alpha,25(OH)2D3-dependent epiphyseal growth plate changes.
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PMID:Effects of 1 alpha,25- and 24R,25-dihydroxyvitamin D3 on aluminum-induced rickets in growing uremic rats. 350 83

We report on a 5-year, prospective, double-blind trial of 1,25 dihydroxycholecalciferol (calcitriol) versus placebo in 76 hemodialysis patients without biochemical or radiological evidence of bone disease. Calcitriol, 1 microgram daily, regularly induced hypercalcemia. Doses of 0.25 microgram daily or less proved satisfactory in most patients. During calcitriol treatment, plasma calcium concentration was significantly higher and serum parathyroid hormone concentration significantly lower than on placebo. There was no difference in the rates of development or of progression of vascular calcification in the two groups. Significantly more patients on placebo (17 vs. 6, p less than 0.05) developed a sustained elevation of plasma alkaline phosphatase concentration. Calcitriol appeared to protect against the development of histological evidence of osteitis fibrosa but not of osteomalacia, but accumulation of aluminum in bone occurred during the study. We conclude that calcitriol delays and may prevent the development of osteitis fibrosa in patients receiving regular hemodialysis and may reasonably be prescribed routinely in hemodialysis patients without biochemical or radiological abnormality, unless there is a substantial prospect of early renal transplantation.
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PMID:Controlled trial of calcitriol in hemodialysis patients. 353 32

Elevated levels of aluminum and beta 2-microglobulin have been demonstrated in chronic dialysis patients. The role of aluminum in the pathogenesis of renal osteodystrophy has also been shown. We report on the effects of beta 2-microglobulin on calcification in vitro using osteoblastic cells, clone MC3T3-El. At concentrations comparable to those in plasma of chronic dialysis patients, both beta 2-microglobulin and aluminum suppressed calcification while collagen synthesis and alkaline phosphatase activity were maintained. These observations may be related to the impaired bone mineralization frequently observed in chronic dialysis patients.
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PMID:Inhibitory effects of beta 2-microglobulin on in vitro calcification of osteoblastic cells. 354 31

45 bone biopsies from patients with chronic uremia were reviewed to define which noninvasive investigations were of value in predicting the histological diagnosis and to quantify the spectrum of uremic bone disease at a center that has consistently used an aluminum-free dialysis bath. 17 biopsies were taken postmortem. 15 patients received conservative treatment, the rest were on maintenance dialysis. 13 patients had symptomatic bone disease. Virtually all patients with a uremia duration greater than 3 years had uremic osteodystrophy. All patients with clinical bone disease, hypercalcemia or raised alkaline phosphatase activity had osteodystrophy, but the specific histology was not indicated. Greatly raised parathyroid levels suggested secondary hyperparathyroidism, but the test was only 100% specific when 20 times normal. Total aluminum consumption was highly indicative of bone aluminum concentration (p less than 0.0001) and aluminum-related osteomalacia (5 cases), suggesting that a considerable proportion of uremic bone disease is iatrogenic. Serum aluminum was of some use in the diagnosis of aluminum-related osteomalacia, but was not wholly reliable. Bone mineral content (BMC) using both forearm measurements and total body bone mineral levels (TBBM) were assessed in 32 patients and were found to be reduced in 12, with a preponderance of secondary hyperparathyroidism. BMC and TBBM were negatively correlated to resorbing surfaces and bone formation rate, suggesting that secondary hyperparathyroidism is the uremic bone disease that represents the greatest threat to bone mass. It is concluded that while noninvasive investigations give considerable information, reliable diagnosis requires the use of histological methods.
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PMID:Noninvasive diagnosis of uremic osteodystrophy: uses and limitations. 363 Nov 50

This study was undertaken to determine the success of surgical treatment of advanced secondary (renal) hyperparathyroidism. From 1978 to 1985, total parathyroidectomy and autotransplantation (TPA) were performed for secondary hyperparathyroidism in 23 patients who had had dialysis for a mean of 6.5 years preoperatively. Indications for surgery included hypercalcemia, bone pain and pathologic fractures, metastatic calcification, and pruritus. Four glands were found and removed in all patients; 100-150 mg of diced tissue were autotransplanted to one forearm. Two patients died of myocardial infarction in the first postoperative week. Bone pain, present in 19 of 23 patients, was relieved almost immediately postoperatively and relief was sustained to death (of unrelated causes) or most recent follow-up in 13 patients. All fractures healed. All patients had markedly elevated serum parathormone (PTH) preoperatively and 14 of 23 were hypercalcemic. The group mean values of serum calcium, alkaline phosphatase, and PTH all fell to and remained in a normal range by 1 year postoperatively in that subset of patients who did not suffer recurrence. Six patients were reoperated on after 12 to 37 months with partial graft excision for recurrent bone pain and hypercalcemia. Bone pain in two of these patients was due to aluminum-associated bone disease and the diagnosis of recurrent secondary hyperparathyroidism was erroneous. The actual recurrence rate was thus 19 per cent. Consistent technical success, with no late hypocalcemia, was achieved and most patients were restored to medical manageability.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:A community hospital experience with total parathyroidectomy and autotransplantation for renal hyperparathyroidism. 368 58

In view of the known toxicity of aluminum, we studied the effects of CaCO3 as an alternative phosphate binder in 12 chronic renal failure (CRF) children during 152 patient-months. Mean (+/- SD) serum creatinine concentration rose during that period from 3.7 +/- 1.8 to 5.1 +/- 3.0 mg/dl. 8 patients received CaCO3 from the start, and 4 were switched from A1(OH)3 after 2 months of interruption. In addition to CaCO3 (0.1-0.3 mg/kg BW) all patients received NaHCO3, and all but two received 1 alpha-hydroxyvitamin D3 [1 alpha(OH)D3] or dihydrotachysterol (DHT). Urine and blood variables were checked every 4-6 weeks and medication dosages were adjusted accordingly, aiming to keep serum Ca at 10.4-10.8 mg/dl, serum Pi at 3.5-5.5 mg/dl, and serum HCO-3 above 18 mEq/l. Bone X-rays were obtained every 6-9 months. With treatment, mean serum Ca increased from 8.9 +/- 0.7 to 10.3 +/- 0.4 mg/dl (p less than 0.01), serum Pi decreased from 6.3 +/- 0.9 to 4.2 +/- 0.5 mg/dl (p less than 0.01), and the mean Ca X P product decreased slightly and insignificantly. Mean serum alkaline phosphatase levels decreased significantly from 486 +/- 251 to 168 +/- 28 IU (p less than 0.01). Bone X-rays at the end of the study showed either healing of renal osteodystrophy or its prevention. Only one episode of mild hypercalcemia (serum Ca 11.7 mg/dl) was observed in 1 patient, but his Ca X P product remained low.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Oral calcium carbonate as phosphate-binder in infants and children with chronic renal failure. 380 30

Bone histologies and serum concentrations of calcium, phosphate, alkaline phosphatase, iPTH, 25 OHD, 1,25(OH)2D3, and aluminum were obtained from 113 chronically hemodialyzed patients free of symptoms and signs of renal osteodystrophy. All patients had a pathologic bone histology; in 69.0%, a mixed form with predominant osteitis fibrosa and concomitant osteoidosis. In 30.1%, we found pure hyperosteoidosis, nearly half of these cases showing osseous aluminum deposits. Hyperosteoidosis was much more frequent in women (35.7%) than in men (20.9%), although the prescribed intake of aluminum-containing phosphate binders was the same. It is possible that female hemodialysis patients were more prone to aluminum accumulation or that they had a better compliance in taking the aluminum hydroxide. Serum parameters alone were not very helpful in predicting the underlying bone disease. Mean iPTH concentrations tended to be lower in the patients with hyperosteoidosis than in those with the mixed lesion, but there was wide variation. Serum aluminum was only predictive for aluminum deposits in the bone when concentrations exceeded 100 micrograms/L.
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PMID:Renal osteodystrophy in asymptomatic hemodialysis patients: evidence of a sex-dependent distribution and predictive value of serum aluminum measurements. 381 72

We evaluated the effectiveness of calcium carbonate as a phosphate binder in 19 children with chronic renal failure; ten children were undergoing dialysis therapy (eight maintained by CAPD and two by hemodialysis). Twelve children had previously received aluminum hydroxide, while calcium carbonate was the primary phosphate binder used in seven children. Among all the children, the serum phosphorus level on no phosphate binder was 7.4 +/- 0.9 mg/dL, which decreased significantly (P less than .001) to 5.9 +/- 0.8 mg/dL during calcium carbonate therapy, while the serum calcium, bicarbonate, and creatinine were unchanged. The reduction in the serum phosphorus level occurred while dietary intake of calcium and phosphorus were unchanged, as demonstrated by three-day dietary records. The dose of calcium carbonate required to maintain the serum phosphorus in the normal range varied from 600 mg to 15 g/d (mean 7.4 g/d). Among the 12 children and four others who had received aluminum hydroxide, serum aluminum levels fell from 108.8 +/- 121.8 ng/mL to 36.1 +/- 29.1 ng/mL after aluminum hydroxide was stopped (P less than .05). Serum alkaline phosphatase and parathyroid hormone (PTH) levels during aluminum hydroxide therapy were similar to levels obtained during calcium carbonate therapy, while PTH levels fell in children treated initially with calcium carbonate. All the children have been observed for a mean of 12.0 months (range 4 months to 3 1/2 years). Hypercalcemia occurred in seven children, usually when vitamin D therapy was initiated or the dose changed. Hypercalcemia resolved with adjustment of the vitamin D or calcium carbonate dose in all but one patient.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Calcium carbonate is an effective phosphorus binder in children with chronic renal failure. 382 69

Dynamic skeletal histomorphometry was performed in 94 unselected patients receiving maintenance dialysis for chronic renal failure. An attempt was made to correlate the results with the clinical, biochemical and radiological findings. Skeletal histology was abnormal in each case. Hyperparathyroidism was present as the only abnormality in 18 patients and osteomalacia in 26; 50 patients showed both abnormalities. Osteomalacia, in contrast to hyperparathyroidism, increased in prevalence and severity with the duration of dialysis and with bone aluminum content. The majority of patients had histological osteosclerosis. It was impossible to predict either the nature or the severity of the histological lesions on the basis of symptoms and physical signs or on the basis of most biochemical parameters (including serum concentrations of three vitamin D metabolites). Serum alkaline phosphatase values and serum immunoreactive parathyroid hormone (iPTH) concentrations were positively correlated with the severity of histological hyperparathyroidism. Subperiosteal erosions of the phalanges were associated with severe histological hyperparathyroidism in each case but this radiological sign was absent in 66% of patients with histological hyperparathyroidism. Radiological osteosclerosis was associated with severe histological osteomalacia in each case, but this radiological sign was absent in 87% of patients with histological osteomalacia. No other radiological sign proved a reliable guide to the underlying skeletal histology. In the majority of dialysis patients, a skeletal biopsy is required for an accurate diagnosis of the nature and severity of azotemic osteodystrophy.
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PMID:Dialysis osteodystrophy. A study involving 94 patients. 383 91

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


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