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

Vitamin D deficiency leads to secondary hyperparathyroidism, increased bone turnover, and bone loss and, when severe, to osteomalacia. Vitamin D deficiency is common in elderly people, especially the institutionalized. The definition of vitamin D deficiency is hampered by the fact that large interlaboratory differences exist in assays for serum 25-hydroxyvitamin D (25OHD), the main circulating metabolite. The international Multiple Outcomes of Raloxifene Evaluation study, a large prospective intervention trial in postmenopausal women with osteoporosis, offered the opportunity to compare vitamin D status and parathyroid function throughout many countries over the world. For this study, baseline data were available from 7564 postmenopausal women from 25 countries on 5 continents. All women had osteoporosis, i.e. bone mineral density (BMD) at femoral neck or lumbar spine was lower than t-score -2.5, or they had 2 vertebral fractures. Serum 25OHD was measured by RIA, and serum PTH was measured by immunoradiometric assay. BMD was measured by dual x-ray absorptiometry. The mean (+/-SD) serum 25OHD was 70.8 +/- 30.9 nmol/L. A low serum 25OHD (<25 nmol/L) was observed in 4.1% of all women in the Multiple Outcomes of Raloxifene Evaluation study, ranging from 0% in south east Asia (very few patients) to 8.3% in southern Europe. Serum 25OHD was between 25-50 nmol/L in 24.3% of the women. Serum 25OHD showed a significant seasonal relationship, with lower values in all regions in winter. Serum PTH correlated negatively with serum 25OHD (r = -0.25; P < 0.001). This significant negative correlation was observed in all regions. When serum 25OHD was less than 25, 25-50, or more than 50 nmol/L, respectively, mean serum PTH levels were 4.8, 4.1, and 3.5 pmol/L, respectively (by ANOVA, P < 0.001). Similarly, mean alkaline phosphatase levels were 83.7, 79.1, and 75.7 U/L (P < 0.001), respectively, with increasing serum 25OHD. The effect of serum 25OHD on BMD was only significant for the BMD of the trochanter where a serum 25OHD level less than 25 nmol/L was associated with a 4% lower BMD. After 6 months of treatment with vitamin D(3) (400-600 IU/day) and calcium (500 mg/day), serum 25OHD increased from 70.8 +/- 29.8 to 92.3 +/- 28.6 nmol/L. Serum PTH decreased significantly after 6 months of treatment, and this decrease depended on baseline serum 25OHD. When baseline serum 25OHD was less than 25, 25-50, or more than 50 nmol/L, respectively, serum PTH decreased by 0.8, 0.5, or 0.2 pmol/L, respectively (P < 0.001). In conclusion, serum 25OHD was less than 25 nmol/L in 4% of the women, and this was associated with a 30% higher serum PTH. In 24% of the women serum 25OHD was between 25-50 nmol/L, associated with a 15% higher level of serum PTH compared with women with a serum 25OHD greater than 50 nmol/L. A low serum 25OHD level was also associated with higher serum alkaline phosphatase and lower BMD of the trochanter. Treatment with vitamin D(3) and calcium increased serum 25OHD and decreased serum PTH significantly; the effect was greater for lower baseline serum 25OHD.
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PMID:A global study of vitamin D status and parathyroid function in postmenopausal women with osteoporosis: baseline data from the multiple outcomes of raloxifene evaluation clinical trial. 1123 11

Psoriatic plaque contains an increased number of mast cells that are thought to play an important role in the initiation and maintenance of the disease through the release of mediators such as histamine, proteoglycans, proteinases and cytokines. To verify the possible participation of these cells in the chronic inflammatory cutaneous response in psoriasis, we performed a double-blind controlled study to investigate the presence and activation of tryptase-positive mast cells in the lesional skin of 19 patients affected by active psoriasis vulgaris minima compared with five healthy, age-matched subjects. Psoriatic patients were randomized into two groups (A and B). The first group was treated with cetirizine (10 mg/three times a day for 15 days) and the second one was treated with placebo. Both groups underwent clinical staging [psoriasis area and severity index (PASI) score] and immunohistochemical evaluation [alkaline phosphatase antialkaline phosphatase (APAAP) procedure] before and after treatment. In group A, the PASI score ranged from 3.8 (SE +/- 1.00) to 1.8 (SE +/- 0.68) and in group B, from 5.0 (SE +/- 0.98) to 3.4 (SE +/- 0.47). The mean number of tryptase-positive mast cells for field, mainly distributed in the perivascular and periadnexal sites, ranged from 40.8 (SE +/- 7.15) to 21.6 (SE +/- 3.04) in group A and from 25.1 (SE +/- 3.78) to 26.3 (SE +/- 3.59) in group B (ANOVA test f = 6.95; gl = 1.16; p = 0.02). In our psoriatic patients, cetirizine significantly reduced the expression of tryptase-positive mast cells and produced a clinical improvement in erythema, suggesting a multilevel immunopharmacologic modulation of this antihistamine in psoriasis.
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PMID:Cetirizine reduces the number of tryptase-positive mast cells in psoriatic patients: a double-blind controlled study. 1151 56

The most common clinical presentation of primary hyperparathyroidism (PHPT) is nowadays characterized by a slight skeletal involvement. We studied 5 consecutive female patients with PHPT presenting with bone turnover marker levels within the reference range of our Center and whose bone mineral density values were above the usual fracture risk threshold. In each patient we measured, both in basal conditions and daily, for the first 5 days after surgery, the following indexes: serum total (T-ALP) and bone-specific (B-ALP) alkaline phosphatase activity, osteocalcin (BGP, by two different assays), together with the 24-hour urinary excretions of total pyridinoline (Pyr/Cr) and deoxypyridinoline (DPyr/Cr), free deoxypyridinoline (FD-Pyr/Cr), cross-linked N-telopeptide of type I collagen (NTx/Cr), and type I C-telopeptide (CTx/Cr). The markers of both bone formation and resorption significantly decreased after surgery (p<0.001 by multiple ANOVA). Individual post-surgical markers changes were all significant but T-ALP and FD-Pyr, the most pronounced percent reductions being shown by NTx and CTx. The time-course of such variations substantially differed among the various indexes. These results show that bone formation and resorption markers are up-regulated also in PHPT patients with mild skeletal involvement; acute removal of parathyroid hormone excess differently affected the markers of bone turnover in terms of both entity and time-course.
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PMID:Short-term effects of surgery in post-menopausal patients with primary hyperparathyroidism and normal bone turnover. 1168 39

Bisphosphonates are potent antiresorptive drugs commonly employed in the treatment of metabolic bone diseases. Despite their frequent use, the mechanisms of bisphosphonates on bone cells have largely remained unclear. Receptor activator of nuclear factor-kappaB ligand (RANKL) is essential for osteoclast formation and activation, whereas osteoprotegerin (OPG) neutralizes RANKL. Various osteotropic drugs have been demonstrated to modulate osteoblastic production of RANKL and OPG. In this study, we assessed the effects of the bisphosphonates pamidronate (PAM) and zoledronic acid (ZOL) on OPG mRNA steady-state levels (by semiquantitative RT-PCR) and protein production (by ELISA) in primary human osteoblasts (hOB). PAM increased OPG mRNA levels and protein secretion by hOB by up to 2- to 3-fold in a dose-dependent fashion with a maximum effect at 10(-6) M (P < 0.001) after 72 h. Similarly, ZOL enhanced OPG gene expression and protein secretion by hOB in a dose-dependent fashion with a maximum effect at 10(-8) M after 72 h, consistent with the higher biological potency of ZOL. Time course experiments indicated a stimulatory effect of PAM and ZOL on osteoblastic OPG protein secretion by 6-fold, respectively (P < 0.001). Pretreatment with PAM and ZOL prevented the inhibitory effects of the glucocorticoid dexamethasone on OPG mRNA and protein production. Analysis of cellular markers of osteoblastic differentiation revealed that PAM and ZOL induced type I collagen secretion and alkaline phosphatase activity by 2- and 4-fold, respectively (P < 0.0001 by ANOVA). In conclusion, our data suggest that bisphosphonates modulate OPG production by normal human osteoblasts, which may contribute to the inhibition of osteoclastic bone resorption. Since, OPG production increases with osteoblastic cell maturation, enhancement of OPG by bisphosphonates could be related to their stimulatory effects on osteoblastic differentiation.
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PMID:Bisphosphonates pamidronate and zoledronic acid stimulate osteoprotegerin production by primary human osteoblasts. 1185 44

Both raloxifene (RLX) and alendronate (ALN) can treat and prevent new vertebral fractures, increase bone mineral density (BMD), and decrease biochemical markers of bone turnover in postmenopausal women with osteoporosis. This phase 3, randomized, double-blind 1-yr study assessed the effects of combined RLX and ALN in 331 postmenopausal women with osteoporosis (femoral neck BMD T-score, less than -2). Women (aged < or = 75 yr; > or = 2 yr since their last menstrual period) received placebo, RLX 60 mg/d, ALN 10 mg/d, or RLX 60 mg/d and ALN 10 mg/d combined. At baseline, 6 and 12 months, BMD was measured by dual x-ray absorptiometry. The bone turnover markers serum osteocalcin, bone-specific alkaline phosphatase, and urinary N- and C-telopeptide corrected for creatinine were measured. The effects of RLX and ALN were considered to be independent and additive if the interaction effect was not statistically significant (P > 0.10) in a two-way ANOVA model. All changes in BMD and bone markers at 12 months were different between placebo and each of the active treatment groups, and between the RLX and RLX+ALN groups (P < 0.05). On average, lumbar spine BMD increased by 2.1, 4.3, and 5.3% from baseline with RLX, ALN, and RLX+ALN, respectively. The increase in femoral neck BMD in the RLX+ALN group (3.7%) was greater than the 2.7 and 1.7% increases in the ALN (P = 0.02) and RLX (P < 0.001) groups, respectively. The changes from baseline to 12 months in bone markers ranged from 7.1 to -16.0% with placebo, -23.8 to -46.5% with RLX, -42.3 to -74.2% with ALN, and -54.1 to -81.0% in the RLX+ALN group. RLX and ALN increased lumbar spine and femoral neck BMD, and decreased osteocalcin and C-telopeptide corrected for creatinine in an additive and independent manner, because the interaction effects were not significant. Although the ALN group had changes in BMD and bone markers that were approximately twice the magnitude as in the RLX group, it is not known how well these changes correlate to the clinical outcome of fracture. RLX+ALN reduced bone turnover more than either drug alone, resulting in greater BMD increment, but whether this difference reflects better fracture risk reduction was not assessed in this study.
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PMID:Additive effects of raloxifene and alendronate on bone density and biochemical markers of bone remodeling in postmenopausal women with osteoporosis. 1188 48

The purpose of this study was to evaluate the responses of succinic dehydrogenase (SDH) and alkaline phosphatase (ALP) activities of human deciduous teeth pulpal fibroblasts (HDPF) to dental restorative materials. Tested materials included Z100 (3M), Dyract (Dentsply), FujiII (GC), and FujiIILC (GC). IRM (Dentsply) and culture medium (MD) alone were used as positive and negative controls, respectively. Specimens 6 mm (diameter) x 3 mm were prepared in accordance with manufacturers' instructions. For light-cured materials, specimens were light cured for 40 s on both sides under a celluloid strip. For chemical-cured materials, specimens were allowed to set at room temperature for 15 min. The specimens were immersed in 1 mL of culture medium without serum for 24 h at room temperature. The extracts were filtered through 0.22-mm filters. HDPF (10,000 cells/well) was incubated with 100 microL of extract and 20 % FBS in a 96-well plate for 24 h in a 37 degrees, 5 % CO(2) incubator. Six wells per material were prepared. Optical density (OD) of SDH and ALP of HDPF were measured by a spectrophotometer. The means were analyzed by ANOVA and then a Duncan Test. The ranking of OD of SDH was IRM < FujiIILC < FujiII = Z100 < Dyract < MD (p < 0.05). The ranking of OD of ALP was IRM < Z100 = Dyract < FujiII < FujiIILC < MD (p < 0.05). The result showed that all of the tested restorative materials were cytotoxic to human deciduous pulpal fibroblasts. The cytotoxicity of resin-modified glass ionomer cements (FujiIILC) was stronger than that of traditional glass ionomer cements (FujiII) and composite resin (Z100), and that of compomer (Dyract) was the weakest. On the contrary, ALP activities of resin-modified glass ionomer cements (FujiIILC) and composite resin (Z100) were higher than those of traditional glass ionomer cements (FujiII), while those of compomer (Dyract) were the lowest. It is concluded that, in this study, FujiIILC was the most cytotoxic material and the least inhibitive of ALP activities, Dyract was the weakest cytotoxic material and had the highest inhibition of ALP activities. The rankings of the MTT assay and the ALP assay were not consistent.
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PMID:Enzymatic responses of human deciduous pulpal fibroblasts to dental restorative materials. 1192 Jun 69

Genetic factors play an important role in determining bone mass and several genes are involved in this process. Interleukin-6 (IL-6) is a candidate gene for regulation of bone mineral density (BMD) and it has been suggested recently that novel IL-6 -174 G/C allelic variants may be associated with peak BMD in young men and with bone resorption in elderly women. In this study, we assessed the relationships between IL-6 gene polymorphism, peak BMD, rate of postmenopausal BMD loss, and bone turnover in women. BMD was measured by dual-energy X-ray absorptiometry in 255 healthy premenopausal women, aged 31-57 years. BMD loss at the forearm was measured over 4 years in 298 healthy untreated postmenopausal women, 50-88 years (mean 64 years). We also measured levels of serum osteocalcin, bone alkaline phosphatase, and N-propeptide of type I collagen for bone formation and three markers of bone resorption, including urinary and serum C-terminal cross-linking telopeptide of type I collagen and urinary N-terminal telopeptide of type I collagen, in both pre- and postmenopausal women at baseline. In premenopausal women we found a significant association between IL-6 genotypes and BMD at the whole body (analysis of variance [ANOVA], p = 0.03), femoral neck (p = 0.03), trochanter (p = 0.014), Ward's triangle (p = 0.03), and total hip (p = 0.006), with subjects having the CC genotype showing 3%-7% higher BMD levels than their GG counterparts. However, after matching women with CC and GG genotypes for body height the differences decreased (2%-4%), and were no longer significant (p = 0.10-0.23). In postmenopausal women the mean rate of loss at the ultradistal radius was significantly associated with IL-6 genotypes (ANOVA, p = 0.049), with women having the CC genotype showing a significantly greater rate of bone loss (p < 0.05) compared with their GC and GG counterparts. After adjustment for weight changes, the difference in the rate of ultradistal radius bone loss between genotypes decreased and was not significant (p = 0.06 for CC vs. GG). A similar trend was observed for distal radius bone loss (p = 0.10, ANOVA), but not for the middle radius. We found no significant association between genotypes, bone turnover markers in premenopausal women, and either bone turnover or BMD in postmenopausal women. We conclude that this new functional IL-6 polymorphism was weakly associated with level of peak BMD and the rate of forearm trabecular postmenopausal bone loss in this cohort of healthy French women. IL-6 genotypes accounted only for a small proportion of the interindividual variation of both peak BMD and rate of bone loss and were not significant after adjustment for height and changes in body weight, respectively, suggesting that part of the effect may have been due to the differences in body size. Larger long-term studies are necessary to assess adequately the relationships between IL-6 genotype, rate of bone loss, and risk of fracture.
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PMID:Association between a functional interleukin-6 gene polymorphism and peak bone mineral density and postmenopausal bone loss in women: the OFELY study. 1211 Apr 11

Hydroxyapatite (HA) has been used in orthopedic, dental, and maxillofacial surgery as a bone substitute. The aim of this investigation was to study the effect of surface topography produced by the presence of microporosity on cell response, evaluating: cell attachment, cell morphology, cell proliferation, total protein content, and alkaline phosphatase (ALP) activity. HA discs with different percentages of microporosity (< 5%, 15%, and 30%) were confected by means of the combination of uniaxial powder pressing and different sintering conditions. ROS17/2.8 cells were cultured on HA discs. For the evaluation of attachment, cells were cultured for two hours. Cell morphology was evaluated after seven days. After seven and fourteen days, cell proliferation, total protein content, and ALP activity were measured. Data were compared by means of ANOVA and Duncan's multiple range test, when appropriate. Cell attachment (p = 0.11) and total protein content (p = 0.31) were not affected by surface topography. Proliferation after 7 and 14 days (p = 0.0007 and p = 0.003, respectively), and ALP activity (p = 0.0007) were both significantly decreased by the most irregular surface (HA30). These results suggest that initial cell events were not affected by surface topography, while surfaces with more regular topography, as those present in HA with 15% or less of microporosity, favored intermediary and final events such as cell proliferation and ALP activity.
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PMID:Surface topography of hydroxyapatite affects ROS17/2.8 cells response. 1238 81

There is general agreement that rough surfaces improve both biologic and biomechanical responses to titanium (Ti) implants. The aim of this investigation was to study the effect of Ti surface roughness on the response of human bone marrow cell culture evaluating: cell attachment, cell proliferation, total protein content, alkaline phosphatase (ALP) activity, and bone-like nodule formation. Cells were cultured on commercially pure titanium (cpTi) discs with fourdifferent average roughnesses (Ra). For attachment evaluation, cells were cultured for 4 h. After 21 days, cell proliferation, total protein content, and ALP activity were evaluated. For bone-like nodule formation, cells were cultured for 28 days. Data were compared by ANOVA and Duncan's multiple range test. Cell attachment was not affected by surface roughness. For cells cultured on Ti with Ra ranging from 0.80 microm to 1.90 microm, proliferation was reduced while total protein content, and ALP activity were increased. There was a non-statistically significant increase of bone-like nodule formation on a surface with Ra near 0.80 microm. These results suggest that for Ti an Ra ranging from 0.80 microm to 1.90 microm would optimize both intermediary and final cellular responses but not affect the initial response, and a smoother surface would not favor any evaluated response.
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PMID:Effect of cpTi surface roughness on human bone marrow cell attachment, proliferation, and differentiation. 1265 59

A polymorphism in the gene encoding methylenetetrahydrofolate reductase (MTHFR) has recently been associated with bone mineral density (BMD) in postmenopausal Japanese women. It is not known whether this effect is also present in European populations and whether it is caused by lower peak bone mass or accelerated postmenopausal bone loss. MTHFR genotyping was done in 1748 healthy postmenopausal Danish women participating in a prospective study of risk factors for osteoporosis. At the time of enrollment, 3-24 months after last menstrual period, the less prevalent genotype (TT, 8.7% of the population) was associated with significantly lower BMD at the femoral neck (ANOVA, p < 0.05), total hip (p < 0.01), and spine (p < 0.05 adjusted for lifestyle covariates, p = 0.06 without adjustment). The mean difference was between 0.1 and 0.3 SD, depending on measurement site. MTHFR genotype added significantly to prediction of BMD by weight and age. Fracture incidence was increased more than 2-fold in subjects with the TT genotype (risk ratio [RR], 2.6; 95% CI 1.2-5.6). This remained significant when the Cox analysis was controlled for BMD (RR, 2.4; 95% CI 1.1-5.2). No differences in serum osteocalcin, bone-specific alkaline phosphatase, and 25-OH-vitamin D were found between genotypes. The response to hormone replacement therapy (HRT) did not differ, but the association of the TT genotype with reduced BMD was maintained at the total hip after 5 years of HRT. The MTHFR TT genotype is associated with low BMD and increased fracture incidence in early postmenopausal women.
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PMID:A common methylenetetrahydrofolate reductase (C677T) polymorphism is associated with low bone mineral density and increased fracture incidence after menopause: longitudinal data from the Danish osteoporosis prevention study. 1267 33


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