Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: 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)

Raloxifene is a selective estrogen receptor modulator that in experimental animals acts as an estrogen receptor antagonist in breast and endometrium but as an estrogen receptor agonist in the skeletal and cardiovascular systems. We conducted a 1-year prospective, randomized, double-blind trial in 143 postmenopausal osteoporotic women (mean +/- SD age, 68.4+/-5.0 years) with at least one prevalent vertebral fractures and low bone mineral density (BMD), comparing groups receiving raloxifene at 60 mg/day (RLX60) or 120 mg/day (RLX120) and a control group receiving supplements of 750 mg/day of calcium and 400 IU/day of vitamin D. There were no differences among groups in the occurrence of uterine bleeding, thrombophlebitis, breast abnormalities, or increased endometrial thickness (assessed by ultrasonography). As compared with controls, the changes in values over 1 year for RLX60 and RLX120, respectively, were significant for serum bone alkaline phosphatase (-14.9%, -8.87%), serum osteocalcin (-20.7%, -17.0%), and urinary C-telopeptide fragment of type I collagen/creatinine (-24.9%, -30.8%), markers of bone turnover; for serum total cholesterol (-7.0% for RLX60) and low density lipoprotein cholesterol (LDL) (-11.4% for RLX60) and for the LDL/HDL cholesterol ratio (-13.2%, -8.3%). BMD increased significantly in the total hip (1.66% for RLX60) and ultradistal radius (2.92%, 2.50%). There were nonsignificant trends toward increases over controls in BMD for lumbar spine, total body, and total hip (for RLX120). Using a >15% cutoff definition, raloxifene had no effect on incident fractures, but using a >30% cutoff, there was a dose-related reduction (p = 0.047). We conclude that raloxifene therapy is well tolerated, reduces serum lipids, and does not stimulate the uterus or breasts. It has beneficial effects on bone, although, under the conditions of this study, these appear to be of a smaller magnitude than have been reported with estrogen therapy.
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PMID:Treatment of established postmenopausal osteoporosis with raloxifene: a randomized trial. 979 84

A new class of compounds known as selective estrogen receptor modulators (SERMs) may possess the optimal combination of characteristics desirable in a drug designed for use in postmenopausal women. Among this class of compounds, raloxifene is the most studied and is currently available for clinical use in some countries for the prevention of osteoporosis in post-menopausal women. Raloxifene is a non-steroidal benzotiophene derivative shown to prevent bone loss at axial and appendicular sites and reduce serum cholesterol, like estrogen, in oophorectomized rats and in postmenopausal women. In animal models, unlike estrogen, raloxifene does not stimulate breast or uterine tissues. These appealing attributes make raloxifene a potential treatment for osteoporosis and other menopause related risks in middle aged and elderly women. Multicenter studies have been performed in early postmenopausal women, randomly assigned to receive raloxifene 30, 60, or 150 mg/day or placebo. All subjects received a calcium supplement. Bone mineral density, which was measured twice a year over 24 months by dual X-ray absorptiometry, decreased significantly at all skeletal sites with placebo, and significantly increased with raloxifene at the spine, hip, and total body at the three doses. At 24 months, the mean increase with raloxifene 60 mg compared with placebo was 2.4% at the lumbar spine and at the total hip, and 2% at the total body. Markers of bone formation (serum osteocalcin and bone specific alkaline phosphatase) and of resorption (urinary CrossLaps) decreased significantly to the premenopausal range within 3-6 months of treatment with raloxifene. In addition, total serum and low-density lipoprotein cholesterol decreased significantly in all raloxifene therapy groups in a dose-related fashion. Serum HDL-cholesterol and triglycerides were not significantly changed by therapy. The most commonly observed side-effect was hot flushes, with patients taking raloxifene reporting a slightly higher rate of flushes (25%) than those on placebo (18%). This adverse event usually occurred within the first few months of therapy, was generally mild, and did not result in excess study dropout (raloxifene 1.5%, placebo 2.1%). Preliminary 2-year data indicated that raloxifene is not associated with an increased risk of breast cancer. In summary, the clinical efficacy and safety of raloxifene is very promising and this compound will offer a particularly attractive choice for postmenopausal women.
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PMID:Clinical efficacy of raloxifene in postmenopausal women. 1042 20

Raloxifene, a selective estrogen receptor modulator (SERM), has been shown to improved bone mineral density (BMD) and serum lipid profiles in healthy postmenopausal women. The objective of this study was to examine the effects of raloxifene on BMD, biochemical markers of bone metabolism and serum lipids in postmenopausal women with low bone density or osteoporosis. This Phase II, multicenter, 24-month, double-masked study assessed the efficacy and safety of raloxifene in 129 postmenopausal women (mean age +/- SD: 60.2 +/- 6.7 years) with osteoporosis or low bone density (baseline mean lumbar spine BMD T-score: -2.8). Women were randomly assigned to one of three treatment groups: placebo, 60 mg/day raloxifene-HCl (RLX 60) or 150 mg/day raloxifene-HCL (RLX 150) and concomitantly received 1000 mg/day calcium and 300 U/day vitamin D3. At 24 months, BMD was significantly increased in the lumbar spine (+3.2%), femoral neck (+2.1%), trochanter (+2.7%) and total hip (+1.6%) in the RLX 60 group compared with the placebo group (p < 0.05). The RLX 150 group had increases in BMD similar to those observed with RLX 60. A greater percentage of raloxifene-treated patients, compared with those receiving placebo, had increased BMD (p < 0.05). Serum bone-specific alkaline phosphatase activity, serum osteocalcin, and urinary type I collagen:creatinine ratio were significantly decreased in the RLX-treated groups, compared with the placebo group (p < 0.01). RLX 60 treatment significantly decreased serum levels of triglycerides, and total- and LDL-cholesterol levels (p < 0.01). The rates of patient discontinuation and adverse events were not significantly different among groups. In this study, raloxifene increased bone density, decreased bone turnover, and improved the serum lipid profile with minimal adverse events, and may be a safe and effective treatment for postmenopausal women with osteoporosis or low bone density.
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PMID:Treatment of postmenopausal women with osteoporosis or low bone density with raloxifene. Raloxifene Study Group. 1069 84

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

Measures with extreme magnitude are most likely to be the result of measurement variability. Repeated measurements genuinely lessen such variability, leading to a phenomenon known as regression to the mean (RTM), which may affect biochemical markers of bone turnover. We therefore studied four markers of bone turnover in the Multiple Outcomes of Raloxifene Evaluation (MORE) trial--serum procollagen type I C-propeptide (PICP), osteocalcin (OC), bone-specific alkaline phosphatase (BAP) and urinary type I collagen breakdown product (CTX)--among the 1704 women treated with raloxifene who had marker measurements and were at least 70% adherent, and among 915 control group patients. We examined the existence of RTM, and applied a method of adjustment for RTM of both baseline and follow-up results. We found that women who had the most extreme values tended to go in the opposite direction with the subsequent measurement, i.e., exhibited a pattern of RTM. For example, among women whose urinary CTX decreased at least 60% in the first 6 months, 61% had an increase in the next 6 months; and among those who had an increase in the first 6 months, 81% had a decrease in the next 6 months. We found a similar pattern for each of the four markers. When adjusting for RTM we obtained estimated true values of both baseline values and change in markers. These estimated true values were substantially different from the observed value when the latter was further from the mean. For example, for a 10% increase in urinary CTX in the first 6 months, after accounting for RTM we estimate that there was in fact a 3% decrease (80% confidence interval: -38% to 53%). We conclude that the few initial extreme marker responses observed in women treated with raloxifene represent RTM, and that one practical consequence is that patients with an increase in markers during the first 6 months should be continued on raloxifene therapy, because the values usually decrease later on.
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PMID:Changes in biochemical markers of bone turnover in women treated with raloxifene: influence of regression to the mean. 1184 25

Estrogen replacement therapy (ERT) decreases total serum calcium by about 0.5 mg/dl in postmenopausal women with primary hyperparathyroidism (PHPT). We investigated the ability of raloxifene, which has skeletal antiresorptive properties similar to those of ERT, to decrease serum calcium concentrations and markers of bone turnover in PHPT. Eighteen postmenopausal women with asymptomatic PHPT were randomized to 8 wk of raloxifene (60 mg/d) or placebo, followed by a 4-wk washout. At baseline, the groups were well matched. The calcium concentration decreased significantly by 8 wk of raloxifene administration (10.8 +/- 0.2 to 10.4 +/- 0.2 mg/dl; P < 0.05), as did markers of bone resorption and formation [osteocalcin, 11.4 +/- 1.6 to 9.9 +/- 1.6 nmol/liter (P < 0.05); serum N-telopeptide, 21.2 +/- 3.4 to 17.3 +/- 2.8 nmol bone collagen equivalents/liter (P < 0.05)]. Four weeks after raloxifene was discontinued, indices were indistinguishable from baseline. Raloxifene administration did not affect serum PTH, 1,25-dihydroxyvitamin D, total alkaline phosphatase, or urinary calcium excretion. Calcium and bone marker changes were therefore similar to those observed with ERT in PHPT. This short-term study suggests that raloxifene may be a useful approach to the treatment of postmenopausal women with mild PHPT.
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PMID:Raloxifene lowers serum calcium and markers of bone turnover in postmenopausal women with primary hyperparathyroidism. 1262 2

Genistein, a soybean isoflavone, has estrogen-like activity in mammals, including the prevention of bone loss. However, whether its mechanism of action on bone turnover is distinct from that of estrogen or raloxifene is unknown. Although genistein has been reported to bind both estrogen receptor (ER) isoforms (alpha and beta), little is known concerning differential activation of gene expression via these ER isoforms. To examine this question, comparison of the responses of normal fetal osteoblast (hFOB) cells stably expressing either ERalpha (hFOB/ERalpha9) or ERbeta (hFOB/ERbeta6), to treatment with genistein, 17beta-estradiol (E(2)) or raloxifene were conducted. In hFOB/ERalpha9 cells, both genistein and E(2) increased the endogenous gene expression of the progesterone receptor (PR), the proteoglycan versican, and alkaline phosphatase (AP), but inhibited osteopontin (OP) gene expression and interleukin-6 (IL-6) protein levels. Raloxifene had no effect on these bone markers. Genistein, but not raloxifene, also mimicked E(2) action in the hFOB/ERbeta6 cells increasing PR gene expression and inhibiting IL-6 production. To determine whether the gene regulatory actions of genistein in human osteoblast cells occur at the level of transcription, its action on the transcriptional activity of a PR-A promoter-reporter construct was assessed. Both genistein and E(2) were found to stimulate the PR promoter in the hFOB cell line when transiently co-transfected with either ERalpha or ERbeta. Whereas hFOB cell proliferation was unaffected by E(2), raloxifene or genistein at low concentrations, higher concentrations of genistein, displayed significant inhibition. Together, these findings demonstrate that genistein behaves as a weak E(2) agonist in osteoblasts and can utilize both ERalpha and ERbeta.
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PMID:Phytoestrogen genistein acts as an estrogen agonist on human osteoblastic cells through estrogen receptors alpha and beta. 1276 96

Raloxifene effectively reduces the incidence of vertebral fractures in patients with postmenopausal osteoporosis. Recent data suggest that low-dose monofluorophosphate (MFP) plus calcium reduces the vertebral fracture rate in postmenopausal women with moderate osteoporosis. The objective of this study was to evaluate the combination of raloxifene and MFP in the treatment of postmenopausal women with osteopenia, osteoporosis and severe osteoporosis. A total of 596 postmenopausal women with osteopenia, osteoporosis and severe osteoporosis (mean femoral neck T-score of -2.87 SD) were randomized to treatment with 60 mg/day raloxifene HCl and 20 mg/day fluoride ions (as MFP) or 20 mg/day fluoride and placebo for 18 months. All patients received calcium (1000 mg/day) and vitamin D (500 IU/day) supplements. Changes in bone mineral density (BMD), as primary endpoint, and the rate of osteoporotic fractures and biochemical markers, as secondary endpoints, were assessed. As compared with MFP, raloxifene plus MFP was associated with significantly greater mean increases in the BMD of the femoral neck (1.37% versus 0.33%; P=0.004), total hip (0.89% versus -0.42%; P<0.001) and lumbar spine (8.80% versus 5.47% P<0.001). In the raloxifene plus MFP group, 16 patients sustained 17 osteoporotic fractures, as compared with 22 patients sustaining 34 incident osteoporotic fractures in the MFP group ( P=0.313). One patient in the raloxifene plus MFP group sustained multiple osteoporotic fractures, as compared with eight patients in the MFP group ( P=0.020). MFP alone significantly increased the serum bone alkaline phosphatase (bone ALP) and the urinary C-terminal crosslinking telopeptide of type I collagene (U-CTX). The addition of raloxifene in the combination arm blunted the rise in bone ALP, which remained nevertheless significant, and abolished the increase in U-CTX. The combination of raloxifene with MFP was generally well tolerated. This study demonstrates that, in postmenopausal women with osteopenia, osteoporosis and severe osteoporosis, the combination therapy of raloxifene plus MFP favorably influences the BMD and the bone formation and resorption balance, and may reduce the risk of multiple osteoporotic fractures compared to MFP alone.
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PMID:Effect of raloxifene combined with monofluorophosphate as compared with monofluorophosphate alone in postmenopausal women with low bone mass: a randomized, controlled trial. 1282 24

Raloxifene reduces bone loss and prevents vertebral fractures in postmenopausal women. Its skeletal effects are mediated by estrogen receptors (ER) and their modulation of paracrine osteoblastic factors. Receptor activator of nuclear factor-kappa B ligand is essential for osteoclasts and enhances bone resorption, whereas osteoprotegerin (OPG) neutralizes receptor activator of nuclear factor-kappa B ligand. Here, we assessed the effects of raloxifene on OPG production in human osteoblasts (hOB). Raloxifene enhanced gene expression of ER-alpha and progesterone receptor. Moreover, raloxifene increased OPG mRNA levels and protein secretion by hOB in a dose- and time-dependent fashion by 2- to 4-fold with a maximum effect at 10(-7) M and after 72 h (P < 0.001). Treatment with the ER antagonist ICI 182,780 abrogated the effects of raloxifene on OPG production. Moreover, raloxifene enhanced osteoblastic differentiation markers, type 1 collagen secretion, and alkaline phosphatase activity by 3- and 2-fold, respectively (P < 0.001). In addition, raloxifene inhibited expression of the bone-resorbing cytokine IL-6 by 25-45% (P < 0.001). In conclusion, our data suggest that raloxifene stimulates OPG production and inhibits IL-6 production by hOB. Because OPG production increases with osteoblastic maturation, enhancement of OPG production by raloxifene could be related to its stimulatory effects on osteoblastic differentiation.
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PMID:Raloxifene concurrently stimulates osteoprotegerin and inhibits interleukin-6 production by human trabecular osteoblasts. 1297 Feb 88

Raloxifene, a nonsteroidal selective estrogen receptor modulator (SERM), increases bone mineral density (BMD), decreases biochemical markers of bone turnover, and prevents incident vertebral fractures in postmenopausal women, while sparing the breast and endometrium from the undesirable stimulation caused by estrogen. How the long-term beneficial effects of raloxifene on bone turnover, as assessed by bone histomorphometry, compare with hormone replacement therapy (HRT) and placebo are not known. We studied 66 healthy postmenopausal women (age 55 to 75 years, mean 63 years) who were randomized to either raloxifene 150 mg/day, HRT (Premarin 0.625 mg/day, and Provera 2.5 mg/day), or placebo for 1 year. All women received 1-1.5 g of calcium/day. Following double tetracycline labeling, transiliac bone biopsies were obtained at baseline and 1 year and analyzed for changes in histologic indexes of bone remodeling on the cancellous surface as well as at the endocortical subdivision of the endosteal envelope, the location of the greatest fraction of postmenopausal bone loss. BMD and biochemical markers of bone turnover were also determined at baseline and 1 year. Four paired biopsies were obtained in the HRT group, six in the raloxifene group, and five in the placebo group. The frequency of remodeling events on cancellous bone and rate of bone formation in both cancellous and endocortical bone increased in the placebo group, while these measurements decreased in both drug treatment groups. Using analysis of mean percentage changes, when compared with the placebo group, these changes were significantly different for both raloxifene and HRT treatment groups (p<0.02). In all subjects, the bone was lamellar with discrete tetracycline labels and there was no evidence of marrow fibrosis or abnormal bone cells. BMD increased from baseline at the lumbar spine (p<0.05 in the HRT group) and in the total body (p<0.05 for both raloxifene and HRT). Compared with that of the raloxifene group, the increase in BMD was greater in the HRT group at the lumbar spine but not in the total body. Serum bone alkaline phosphatase, serum osteocalcin, and urine C-terminal cross-linking telopeptide of type I collagen significantly decreased (p<0.05) in both active treatment groups, changes significantly different from those seen with placebo. Overall, these results support the hypothesis that raloxifene preserves bone mass by reducing the elevated bone turnover found in postmenopausal women receiving placebo, by mechanisms similar to those operative in postmenopausal women receiving HRT.
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PMID:Effects of raloxifene, hormone replacement therapy, and placebo on bone turnover in postmenopausal women. 1461 Jun 42


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