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)

Recently, several reports have suggested that there is a higher incidence of low turnover bone in the absence of aluminium exposure in peritoneal dialysis patients than in hemodialysis patients. Relative hypoparathyroidism with mild hypercalcemia, induced by a positive calcium balance, is considered to be one of the major causes of this disorder. Thus, we recruited 9 continuous ambulatory peritoneal dialysis (CAPD) patients with relative hypoparathyroidism and low bone turnover [intact parathyroid hormone (iPTH) < 50 pg/mL, intact osteocalcin < 10.0 ng/mL] who had been prescribed 1.75 mmol/L calcium (Ca) dialysate for 5.0 +/- 0.3 years. They were then treated by low Ca (1.25 mmol/L) dialysate for nine months without vitamin D and aluminum administration. Intact PTH and bone metabolic markers [intact osteocalcin, alkaline phosphatase (ALP)] were measured every three months. Intact PTH levels increased from 21.1 +/- 3.8 to 159.2 +/- 32.8 pg/mL after the first three months; thereafter, those levels were maintained at around 150 pg/mL. On the other hand, intact osteocalcin levels rose consecutively from 6.7 +/- 1.2 to reach 22.0 +/- 3.8 ng/mL after nine months. Interestingly, the pattern of time course changes between PTH and intact osteocalcin was different. ALP activity did not change during the nine-month period. Corrected serum calcium was significantly decreased (p < 0.001) to approximately 0.25 mmol/L within one month, and the level remained almost the same thereafter. The serum phosphate level did not change without adjusting the original dose of calcium carbonate as a phosphate binder. We concluded that low Ca dialysate (1.25 mmol/L) is effective for the treatment of CAPD-related hypoparathyroidism with low bone turnover.
Adv Perit Dial 1996
PMID:Low calcium (1.25 mmol/L) dialysate can normalize relative hypoparathyroidism in CAPD patients with low bone turnover. 886 14

In the present work, we studied: (i) the effect of different doses of desferrioxamine and deferiprone on the proliferation of osteoblasts and the possible role of iron in this; and (ii) the effect of both chelators on the metabolic activity of these cells, using the quantification of alkaline phosphatase as an enzymatic marker of cellular activity or differentiation. Cellular proliferation was investigated at different concentrations of deferiprone and desferrioxamine, and the effect of the addition of iron citrate on this proliferation was measured. The production of alkaline phosphatase after incubation with deferiprone (150 and 300 microM) and desferrioxamine (20 and 100 microM) was also studied. Cellular proliferation was completely inhibited with 100 microM of desferrioxamine and 300 microM of deferiprone. In both cases, this effect was corrected by means of co-incubation with iron citrate. In the second phase, using the same dose that inhibited the proliferation, it was observed that after 24 h, both chelators slightly decreased alkaline phosphatase activity, while at 48 and 96 h they increased alkaline phosphatase activity. These results demonstrate that both desferrioxamine and deferiprone inhibit the proliferation of the osteoblast-like cell line MG-63; the effect seems to be related to the chelation of some fraction of available iron. In spite of the effect on bone cell proliferation, the chelators do not impair cellular activity.
Nephrol Dial Transplant 1998
PMID:Effect of desferrioxamine and deferiprone (L1) on the proliferation of MG-63 bone cells and on phosphatase alkaline activity. 956 16

Renal osteodystrophy (ROD) is a multifactorial disease. Aluminium deposits have been implicated in its physiopathology but iron deposits have seldom been described. The purpose of this study was to investigate the presence of iron on the mineralization front, in 70 patients with ROD. Their mean age was 48+/-16 years, 36 were female, 34 male, 55 were admitted on peritoneal dialysis (78.5%) and 15 to haemodialysis (21.5%), for a period of 28+/-22 months. A bone biopsy was obtained from each patient after double tetracycline labelling. Blood samples were also obtained at the time of bone biopsy. The histomophometric analysis was performed following the criteria of Sherrard et al., with slight modifications; beside the usual stains, aluminium, iron and amyloid stainings were done on all bone specimens. Biochemical findings were: Ca 8.8+/-0.9 mg/dl, P 6.1+/-1.5 mg/dl; total alkaline phosphatase 197+/-258; PTHm 4.9+/-4.05ng/ml (normal 0.4-0.7 ng/ml), calcitonin 11+/-6 pg/ml (normal 1-26 pg/ml). Osteitis fibrosa was found in 31 patients (44.28%), mixed bone disease in two patients (2.28%); mild bone disease in 20 subjects (28.57%), adynamic bone lesion in 15 cases (21.42%) and osteomalacia in two patients (2.28%). Iron deposits were found on the mineralization front in 43 patients (61.4%); in 17, the percentage was <25 and, in 26, >25%. The iron deposits in the osteitis fibrosa group were highly significant (25/31). The aluminium deposit at the mineralization front was observed in eight patients (11.4%); in all but one, the percentage of this metal was <10%. Amyloid deposits were negative in all cases. The results show: (i) a Mexican population with ROD, present a highly significant incidence of siderosis on the bone mineralization front; (ii) in contrast, the aluminium deposits in this group of patients is lower than that reported in other series, and (iii) the spectrum of RO in this Mexican population is similar to that reported in other studies.
Nephrol Dial Transplant 1998
PMID:High frequency of iron bone deposits in a Mexican population with renal osteodystrophy. 956 20

The purpose of the present study is to investigate whether an ethnic difference exists in the incidence of renal osteodystrophy between Asian and Western countries in end-stage renal disease (ESRD) patients. We evaluated bone histology in 58 pre-dialysis patients (28 male, 30 female; mean age: 47.7 years). All patients had bone biopsies with quantitative histomorphometry and serological parameters such as intact PTH, osteocalcin, total alkaline phosphatase, and basal and deferoxamine-stimulated serum aluminum levels. We observed that 91.4% of all evaluated patients showed renal osteodystrophy before the start of dialytic therapy. Mild osteitis fibrosa were observed in 21 patients (36.2%), severe osteitis fibrosa in 5 patients (8.6%), mixed lesions in 7 patients (12.1%), osteomalacia in 6 patients (10.3%), aplastic bone disease in 14 patients (24.1%), and normal bone in 5 patients (8.6%). Among the bone histomorphometric parameters, fibrosis area rate (%) showed the best correlation with intact PTH, and osteocalcin and osteoid area rate (%) with total alkaline phosphatase. Aluminum-related bone disease was not observed. Among patients with aplastic bone disease, only 14.3% showed aluminum deposition of any significance (5% < stainable bone surface aluminum < 25%). In the diabetic patients, aplastic bone disease was most common, but no case was related to aluminum intoxication. In conclusion, the distribution of renal osteodystrophy in our study was different from that of Western countries in pre-dialysis patients. Our patients tended to have more mild-form osteitis fibrosa and normal findings, and less severe-form osteitis fibrosa and aplastic bone disease. Aluminum-related bone disease was not observed.
Perit Dial Int 1999
PMID:Renal osteodystrophy in pre-dialysis patients: ethnic difference? 1040 54

One of the classic histologic forms of renal osteodystrophy is osteitis fibrosa, and its distinguishing characteristic is bone marrow (BM) fibrosis, caused by the activation of marrow parenchymal cells. A bone biopsy must be performed in order to establish the diagnosis of renal osteodystrophy. The clinical use of bone biopsy is restricted, however, due to the invasiveness of the procedure. In recent studies, bone scans have provided information useful for the differential diagnosis between osteomalacia and osteitis fibrosa. However, bone scans can not provide information on the bone marrow status. Bone marrow immunoscintigraphy (BMIS) using Tc-99m anti-granulocyte antibody (AGA), a highly sensitive test for the detection of bone marrow abnormalities which is also a noninvasive method, has rarely been reported in chronic renal failure (CRF). BMIS can provide information in patients with myelofibrosis. The purpose of this study was to evaluate the usefulness of BMIS in CRF patients with special regards to biochemical parameters. Nineteen CRF patients (13 men, 6 women; mean age: 48 +/- 11 years) in whom bone scintigraphy using Tc-99m MDP (methylene diphosphonate) showed the so-called superscan pattern were included in the study. Their primary renal diseases were chronic glomerulonephritis (n = 14), diabetes (n = 4), and polycystic kidney disease (n = 1). Modes of therapies were continuous ambulatory peritoneal dialysis (CAPD) (n = 13; mean duration: 9.5 months), HD (n = 5; mean duration: 7.8 months), and conservative treatment (n = 1). BMIS using Tc-99m labeled anti-granulocyte monoclonal mouse antibody BW250/183 was performed, and the results were compared with the biochemical parameters of the patients. According to the presence of BM expansion, which may represent marrow fibrosis, the 19 patients were divided into two groups: Group I (n = 7) with BM expansion and Group II (n = 12) with normal marrow distribution. The biochemical parameters and bone markers of Group I were compared with those of Group II. There was no significant difference in biochemical parameters (blood hemoglobin, serum ferritin, erythropoietin, BUN, creatinine) between the two groups. There were no significants difference in serum calcium, phosphorus, tartate-resistant acid phosphatase (TRAP), and intact parathyroid hormone (iPTH) between the two groups. Serum alkaline phosphatase (ALP) and osteocalcin were significantly (P < 0.05) higher in Group I than in Group II. These results suggest that patients with bone marrow expansion in BMIS have increased levels of ALP and osteocalcin, indicating an increased osteoblastic activity. BMIS may be useful for the detection of bone marrow expansion due to marrow fibrosis in renal osteodystrophy, and for the evaluation of the extent of bone marrow fibrosis.
Adv Perit Dial 1998
PMID:Bone marrow immunoscintigraphy (BMIS): a new and important tool for the assessment of marrow fibrosis in renal osteodystrophy? 1064 20

Adynamic bone disease (ABD) has an increasing prevalence in the dialysis population, more so in peritoneal dialysis patients. Anemia in patients with high turnover bone disease and high intact parathyroid hormone (iPTH) tends to be resistant to recombinant human erythropoietin (rHuEPO). The same problem may occur in patients with ABD; however, data are scarce. This study evaluates the effectiveness of rHuEPO in 32 chronic peritoneal dialysis patients, 9 with iPTH levels below 100 pg/mL for more than 6 months (group A, with ABD) and 23 with iPTH levels above 100 pg/mL (group B, without ABD). In group A and group B respectively, the dosage of rHuEPO was 141.8 +/- 59 U/kg/week and 144.8 +/- 77 U/kg/week, and hematocrit was 33.2% +/- 4.3% and 31.7% +/- 4.5% (p > 0.05). Iron indices, nutritional parameters, and bone indices were similar, except that group A had lower alkaline phosphatase and serum ferritin levels. The data suggest that patients with ABD may not be resistant to rHuEPO, but may even have a slightly better hematocrit at a similar rHuEPO dosage. Further studies in a larger number of patients are needed to confirm these findings.
Adv Perit Dial 2000
PMID:Influence of adynamic bone disease on responsiveness to recombinant human erythropoietin in peritoneal dialysis patients. 1104 14

Controversy exists among various studies in regard to the efficacy of oral (p.o.) versus parenteral calcitriol. Some studies suggest that intravenous (i.v.) calcitriol is superior to p.o. calcitriol for treating renal osteodystrophy in hemodialysis patients; others suggest that these routes of administration are equivalent. To our knowledge, no large, prospective, randomized study compares intraperitoneal (i.p.) to p.o. calcitriol in adult peritoneal dialysis patients. We conducted a prospective randomized study in 76 patients (38 on i.p. calcitriol and 38 on p.o. calcitriol), whom we followed for 48 months. Of the 76 patients, 34 (18 in the i.p. group and 16 in the p.o. group) completed the 48-month study period. Calcitriol dosing was similar in both groups (3-6 micrograms per week in three divided doses). Dose adjustments were made depending on levels of parathyroid hormone (PTH), serum calcium, phosphorus, and calcitriol. No significant difference was seen between the groups in regard to age, sex, race, body mass index, dialysis duration, or cause of ESRD. Neither was any difference in the incidence of peritonitis seen between the groups. In the first 3-6 months, PTH decreased equivalently in both groups. The PTH level remained suppressed in the i.p. group throughout the remainder of the study, but, in the p.o. group, PTH returned to its pretreatment level after 3-6 months. Mean serum calcium was not different in the two groups. In the p.o. group, a considerably higher mean follow-up phosphorus level (6.8 +/- 2.3 mg/dL versus 4.7 +/- 1.4 mg/dL, p = 0.008), PTH level (384 +/- 146 pg/mL versus 162 +/- 64 pg/mL; p = 0.005), and alkaline phosphatase level (178 +/- 37 IU/L versus 72 +/- 21 IU/L, p = 0.02) were seen as compared to the i.p. group. In the i.p. group, resolution of osteodystrophy occurred in all patients at the end of the study; in the p.o. group, 5 patients maintained or developed osteodystrophy by the end of the study (p = 0.016). We conclude that i.p. calcitriol is more effective than pulse p.o. calcitriol in lowering PTH and alkaline phosphatase levels and in resolving renal osteodystrophy, and that i.p. calcitriol is associated with a lower incidence of hyperphosphatemia and elevated Ca x PO4 byproduct.
Adv Perit Dial 2000
PMID:Pulse oral versus pulse intraperitoneal calcitriol: a comparison of efficacy in the treatment of hyperparathyroidism and renal osteodystrophy in peritoneal dialysis patients. 1104 16

A trial on the long-term administration of 1,25-dihydroxy-22-oxavitamin D(3) (22-oxacalcitoriol, OCT) was conducted among 124 patients with chronic renal failure on maintenance haemodialysis (HD) complicated with secondary hyperparathyroidism (2HPT). In the trial, OCT was administered three times weekly for 26 weeks subsequent to a 26-week pre-trial. As a result, intact-parathyroid hormone (PTH) levels fell significantly after the start of administration and, at the end of the trial, PTH was decreased by over 30% in 51.6% (64/124) of the patients, and the levels of bone metabolism markers such as alkaline phosphatase (ALP), bone ALP, and tartrate-resistant acid phosphatase (TRACP) were significantly decreased compared with those at the start of administration, suggesting a correction of high-turnover bone disease. Serum calcium (Ca) levels rose significantly following OCT administration, but were successfully maintained within a physiological level. Hypercalcaemia, which was diagnosed in 33.1% of patients, was found to resolve or ameliorate immediately after the withdrawal or dose reduction of OCT. OCT can be administered for as long as 1 year without any major problems other than hypercalcaemia. The final doses ranged from 2.5 to 20.0 microg/HD, and the optimal dose varied among patients depending on the intact-PTH and adjusted serum Ca levels. These results suggest that OCT is a highly effective drug for the suppression of PTH levels in 2HPT, and is an overall safe drug if the dosage is adjusted for serum Ca and intact-PTH levels. This study confirmed that the long-term (1-year) administration of OCT is very useful for the treatment of 2HPT.
Nephrol Dial Transplant 2002
PMID:Long-term effect of 1,25-dihydroxy-22-oxavitamin D(3) on secondary hyperparathyroidism in haemodialysis patients. One-year administration study. 1238 66

The common intact parathyroid hormone (i-PTH) assay detects not only PTH (1-84) but also the PTH (7-84) fragment. Recently, it was reported that the PTH (7-84) fragment is an antagonist to the biological action of PTH (1-84). It was also reported that the accumulation of the PTH (7-84) fragment plays a role in skeletal resistance in haemodialysis (HD) patients. However, the role of accumulation of the PTH (7-84) fragment in continuous ambulatory peritoneal dialysis (CAPD) patients, with a different clearance rate from that of HD patients, is still unclear. Therefore, we have measured only the active form of PTH (1-84) using a new method of whole PTH (w-PTH) assay in 20 CAPD patients (15 male and five female; mean age 51.0+/-13.0 years). The mean w-PTH value was 88.5 +/-14.2 pg/ml in CAPD patients, which was 42.1% of i-PTH (152.6+/-23.6 pg/ml). The approximate value of w-PTH was calculated using the following formula (w-PTH=0.58 x iPTH-0.4, R(2)=0.94). PTH (7-84) fragment was calculated by the formula i-PTH-w-PTH. The PTH (7-84) fragment/w-PTH ratio as an index of skeletal resistance, and serum alkaline phosphatase activity as an osteoblastic marker were negatively correlated (P=0.02). From these results, we concluded that the i-PTH level as calculated using the common assay method might lead to an overestimation of parathyroid function and bone turnover in CAPD patients similarly to HD patients. The w-PTH assay may be useful for more precise evaluation of PTH activity in end-stage renal disease patients.
Nephrol Dial Transplant 2003 Jun
PMID:IRMA (whole PTH) is a more useful assay for the effect of PTH on bone than the Allegro intact PTH assay in CAPD patients with low bone turnover marker. 1277 13

Measuring the free:total ratio of prostate-specific antigen (f/t-PSA) can improve the specificity of single-serum PSA values, distinguishing between benign prostatic hyperplasia (BPH) and prostatic carcinoma (PCa) in men over the age of 50. Additionally, clinical trials have shown that dihydroxyvitamin D3 can slow the rate of PSA rise in PCa patients. However, little is known regarding the applicability of those findings in men undergoing chronic peritoneal dialysis (CPD). In the present study, we investigated the prevalence of increased serum PSA levels among CPD patients and correlated those values with serum levels of vitamin D [25-hydroxyvitamin D3 and 1,25-dihydroxyvitamin D3]. We undertook a cross-sectional study of 71 male CPD patients without a known history of prostate cancer from 24 centers in Canada, Greece, and Turkey. All of the patients were more than 50 years of age. In these patients, we measured serum concentrations of PSA, free PSA (f-PSA), total PSA (t-PSA), prostate alkaline phosphatase (PAP), 25-hydroxyvitamin D3, 1,25-dihydroxyvitamin D3, and intact parathyroid hormone (iPTH). We recorded serum PSA levels < 4 ng/mL in 62 patients (87.3%, group A) and levels > 4 ng/mL in 9 patients (12.7%, group B). The f/t-PSA ratio was < 0.25 in 16 patients (22.5%). Group B patients were older than those in group A (median: 73 years vs. 65 years, p < 0.01) and had a lower body weight (median: 66.5 kg vs. 76.7 kg, p < 0.05). We observed no statistically significant difference between the two groups for serum 1,25-dihydroxyvitamin D3 (median: 9.8 ng/mL vs. 10.1 ng/mL) or 25-hydroxyvitamin D3 (8 ng/mL vs. 8.2 ng/mL) levels. Also, we observed no correlation between vitamin D levels and f/t-PSA, but iPTH levels were significantly higher in group A (200.5 pg/mL vs. 61.2 pg/mL, p < 0.04). Also, serum PAP levels correlated significantly with PSA (r = 0.49, p = 0.01) and with f-PSA (r = 0.56, p = 0.000). Our results showed no clear relationship between vitamin D and serum levels of PSA or-of f/t-PSA in PD patients. However, further studies are needed to better define the uses of these PSA markers in PD patients because, in such patients, other relevant factors might be implicated in their predictive value.
Adv Perit Dial 2004
PMID:Serum levels of prostate-specific antigen and vitamin D in peritoneal dialysis patients. 1538 27


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