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)

We present data on the changes of the bone formation markers osteocalcin (OC), bone-specific alkaline phosphatase (bone ALP) and bone sialoprotein (BSP), as well as the resorption markers pyridinoline (PYD), deoxypyridinoline (DPD), C- and N-terminal telopeptide cross-linked collagen type I (CTX, NTX), and tartrate-resistant acid phosphatase type 5b (TRACP) at five time points during the course of two years in healthy premenopausal, perimenopausal and early postmenopausal women. The prospective study showed that CTX (p<0.001), NTX (p=0.001) and TRACP (p=0.001), as well as bone ALP (p=0.009) and OC (p=0.052), were significantly increased already in the transition period from peri- to postmenopause. The pyridinium crosslinks indicated an increased collagen degradation rate already in the perimenopause (PYD, p=0.017; DPD, p=0.054). Significant inverse correlations with the two years changes of the bone mineral density were found for bone ALP, CTX, OC and DPD in the perimenopausal group. The measurement of a comprehensive panel of biochemical bone markers clearly shows that metabolic changes in bone metabolism appear pronounced in the perimenopause, a period still presenting satisfactory estrogen supply. Thus, the perimenopause is an important phase for a contingent development of osteoporosis.
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PMID:Changes of biochemical bone markers during the menopausal transition. 1193 87

The Asp1211 residue of the 1209AHDGGR1214 sequence of the C-terminal cross-linking telopeptide of type I collagen (CTX) can undergo spontaneous post-translational modifications, namely, racemization and isomerization, which result in the formation of four isomers: the native form (alpha-L) and three age-related forms, that is, an isomerized form (beta-L), a racemized form (alpha-D), and an isomerized/racemized (beta-D) form. Previous studies have suggested that changes in the pattern of type I collagen racemization/isomerization, which can be assessed in vivo by measuring the degradation products of the CTX isoforms, may be associated with alterations of bone structure. The aim of this study was to examine prospectively the value of the different urinary CTX isoforms and their related ratio in the prediction of osteoporotic fractures in 408 healthy untreated postmenopausal women aged 50-89 years (mean, 64 years) who were part of the OFELY cohort. During a median 6.8 years follow-up, 16 incident vertebral fractures and 55 peripheral fractures were recorded in 65 women. The baseline levels of the four CTX isoforms in women who subsequently had a fracture were compared with those of the 343 women who did not fracture. At baseline, women with fractures had increased levels of ratios of native alpha-L-CTX to age-related isoforms (beta-L, alpha-D, and beta-D) compared with controls (p < 0.01). In logistic regression analysis after adjustment for age, prevalent fractures, and physical activity, women with levels of alpha-L/beta-L, alpha-L/alpha-D, and alpha-L/beta-D-CTX ratios in the highest quartile had a 1.5- to 2-fold increased risk of fractures compared with women with levels in the three lowest quartiles with relative risk (RR) and 95% CI of 2.0 (1.2-3.5), 1.8 (1.02-2.7), and 1.5 (0.9-2.7), respectively. Adjustment of alpha-L/beta-L and alpha-L/alpha-D-CTX ratios by the level of bone turnover assessed by serum bone alkaline phosphatase (ALP)- or femoral neck bone mineral density (BMD) decreased slightly the RR, which remained significant for the alpha-L/beta-L-CTX ratio (RR [95%] CI, 1.8 [1.1-3.2] after adjustment for bone ALP, 1.8 [1.03-3.1] after adjustment for BMD, and 1.7 [0.95-2.9] after adjustment for both bone ALP and BMD). Women with both high alpha-L/beta-L-CTX ratio and high bone ALP had a 50% higher risk of fracture than women with either one of these two risk factors. Similarly, women with both increased CTX ratio and low femoral neck BMD (T score < -2.5) had a higher risk of fracture with an RR (95% CI) of 4.5 (2.0-10.1). In conclusion, increased urinary ratio between native and age-related forms of CTX, reflecting decreased degree of type I collagen racemization/isomerization, is associated with increased fracture risk independently of BMD and partly of bone turnover rate. This suggests that alterations of type I collagen isomerization/racemization that can be detected by changes in urinary CTX ratios may be associated with increased skeletal fragility.
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PMID:Type I collagen racemization and isomerization and the risk of fracture in postmenopausal women: the OFELY prospective study. 1200 13

To examine the effect of estradiol (E(2)) without the confounding effect of hypothalamic-pituitary feedback, we studied men with prostate cancer in whom gonadotropin secretion was suppressed by LH-releasing hormone agonists (LHRH-A). Fourteen men over 65 yr of age and receiving established LHRH-A treatment (EST group) without bony metastases and 12 men who received LHRH-A as neoadjuvant therapy for locally advanced prostate cancer (NEO group) were randomized (double blind) to receive either 1 mg/d micronized E(2) (n = 12) or placebo (PL; n = 13) for 9 wk. E(2), estrone, testosterone, SHBG, PTH, and 25-hydroxy- and 1,25-dihydroxyvitamin D levels as well as markers of bone resorption [N- and C-telopeptide cross-links (NTX and CTX) and deoxypyridinoline] and bone formation (bone-specific alkaline phosphatase, osteocalcin, and N-terminal type I collagen) were measured before LHRH-A in the NEO group, before [baseline (BL)] and after 9 wk of E(2) or PL in all patients, and 6 wk after E(2) treatment in the EST group. In the NEO group, hormone levels fell 3 wk after the initial LHRH-A injection, and deoxypyridinoline increased significantly (P = 0.006). At BL, the EST group had higher bone turnover due to the longer duration of LHRH-A treatment. With E(2) treatment, E(2) levels rose into the normal male range, and two resorption markers decreased significantly from BL by 33% for NTX (P < 0.001) and 28% for CTX (P = 0.009). Bone formation markers did not change. PTH increased by 43% from BL (P < 0.01) in the E(2) group and decreased 16% from BL in the PL group (P < 0.01). Ionized calcium did not change in the E(2) group, but increased in the PL group by 2.3% (P < 0.01). NTX and CTX increased 6 wk after E(2) withdrawal in the EST group. We conclude that E(2) inhibits bone resorption in hypogonadal men through a direct skeletal effect that is independent of PTH. Low dose estrogen may be an option for the prevention and/or treatment of bone loss in this population.
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PMID:The effect of micronized estradiol on bone turnover and calciotropic hormones in older men receiving hormonal suppression therapy for prostate cancer. 1241 49

To investigate day-to-day biological change of biochemical makers of bone turnover, we measured eight markers for 5 days in 10 healthy women. They aged 26-41 years (mean age; 31.1 years old), and had regular menstrual cycles. Fasting second void urine and blood was collected from them on five successive days. As serum marker, Estradiol (E2), intact PTH (i-PTH), Bone-specific alkaline phosphatase (BAP), and serum C-telopeptide (S-CTX) were measured. As urinary markers, urinary CTX (U-CTX), N-telopeptide (NTX), pyridinoline (Pyr) and deoxypyridinoline (Dpyr) were measured. Day-to-day physiological variations were different between bone markers. Variability of serum markers was less than that of urinary markers. Moreover, in the comparison of the same molecular marker, CTX, the variability of S-CTX was less than U-CTX. One should consider physiological variation of the marker to evaluate whether the change of the biochemical marker of bone turnover is significant or not.
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PMID:Biological variability of biochemical markers of bone turnover in healthy women. 1248 74

A 30-yr-old Caucasian man with a history of dorsal and lumbar back pain, which responded partially to antiinflammatory agents, was seen at our Unit. The biochemical bone markers showed an increment in bone alkaline phosphatase and urinary CTX. Serum phosphate tended to be low. Radiographic abnormalities were marked osteosclerosis in the pelvis and vertebral bodies without changes in size. Bone scintigraphy results were normal. The increase in bone mineral density (BMD) was greater in L2-L4 (+ 3.9 SDs) than in total skeleton (+ 1.4 SDs). Analysis of skeletal subareas showed a marked increase in axial skeleton BMD: trunk, +4.0 SDs; spine, +2.5 SDs and pelvis, +4.5 SDs. BMD of the remaining subareas was found to be normal: skull, +0.04 SDs; arms, -0.3 SDs and legs, -0.05 SDs. The patient refused to have a bone biopsy. The radiologic, densitometric, and biochemical findings in the patient presented herein are compatible with axial osteomalacia. Evaluation of total skeleton BMD, and especially skeletal subareas, clearly indicated that the abnormal BMD was restricted to the spine and pelvis whereas the rest of the skeleton was not affected.
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PMID:Bone densitometry of a patient with osteosclerosis. 1266 4

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

Malnutrition in elderly people contributes to osteoporosis and fracture. The aim of the study was to investigate the effects of nutritional improvement on bone metabolism in elderly community-dwelling women. A 12-month randomized controlled trial of 71 ambulant women aged > or =70 years with BMI < or =21 kg/m(2 )and osteoporosis at the hip was undertaken. They received either calcium (1 g) and vitamin D (800 units of cholecalciferol) only (group 1: n=35) or calcium/vitamin D and one or two cartons of a nutritional supplement drink which provided 300 Kcal, 12 g protein, 11.6 g fat and 36.8 g carbohydrate per carton (group 2: n=36). Body composition and bone mineral density (BMD) were assessed at baseline and 12 months. Biochemical markers of bone turnover were measured at baseline and at 1, 3, 6, 9 and 12 months. Group 2 gained significantly more weight [mean (SD) group 1: 0.15 (2.45), group 2:2.66 (2.8) kg P<0.001] and fat mass [group 1: -0.26 (1.8), group 2:1.9 (1.7) kg P<0.001]. BMD at the spine, femoral neck and total hip did not change significantly, although there was a positive trend at the total hip in group 2 [group 1: -0.5 (5.2), group 2:1.25 (3.3)%, P=0.13]. In a subgroup analysis, irrespective of their treatment group, there was a significant difference in changes in BMD at the lumbar spine and total hip in those who lost body weight (A) compared to those who had maintained or increased their weight (B), [mean (SD) % change in BMD lumbar spine; A: -1.64 (3.75), B: 0.96 (2.75) P=0.013, total hip A: -2.09 (6.0), B: 1.04 (3.3), P=0.05)] A significant reduction in serum CTX, a marker of bone resorption, was seen in group 2 [% decrease at 3 months, group 1: 1 (8.7), Group 2: 32 (5.8), P<0.01]. Serum osteoprotegerin (OPG) increased significantly in group 2 with a maximal increase (27%) observed at 6 ( P<0.01) and 9 months ( P<0.05). A small increase in bone-specific alkaline phosphatase was seen at 12 months in group 2 [% increase group 1:5 (5), group 2: 17 (6), P=0.05]. Serum osteocalcin increased at 12 months in group 2 ( P=0.01). Dietary improvement in elderly women with low BMI is associated with a reduction in bone resorption with a small but "net" positive effect on bone formation.
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PMID:Effects of dietary improvement on bone metabolism in elderly underweight women with osteoporosis: a randomised controlled trial. 1290 40

The beneficial effects of hormone replacement therapy (HRT) on bone mineral density (BMD) and bone turnover are well documented but whether HRT withdrawal is followed by an accelerated rate of bone loss is still controversial. We analyzed 26 women who have withdrawn HRT during a 6-year follow-up of the OFELY cohort. They were compared with three groups of women from the same cohort: one hundred four healthy postmenopausal women who continued HRT during the 6-year follow-up, 78 untreated postmenopausal women matched for age, and 31 untreated women within 5 years of menopause. Bone markers [serum osteocalcin (Intact OC), bone alkaline phosphatase (Bone ALP), and serum CTX] were performed annually during 4 years and bone mineral density (BMD) was measured at the forearm (DXA) during 6 years. Withdrawal of HRT was followed by a significant bone loss with an annual rate ranged from -0.7 to -1.6% at the radius according to the skeletal site and by a marked increase of bone markers after 6 months: +36 % for osteocalcin, +23% for bone alkaline phosphatase, and +120% for serum CTX (P < 0.05 to P < 0.001). In contrast, in the HRT continuing group, there was no bone loss and no substantial change of bone markers over 4 years. The rate of bone loss after withdrawal of HRT was significantly greater than in postmenopausal women matched for age who never received HRT (2.2 to 2.8 times higher according to the radius area) and not different as compared to the accelerated bone loss observed in untreated women within 5 years of menopause. We conclude that in postmenopausal women who have been on HRT for 6 years, cessation of treatment results in a rapid increase of bone turnover and a rate of bone loss similar to early postmenopausal women during the subsequent 4 years and greater than untreated women of the same age.
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PMID:Effect of withdrawal of hormone replacement therapy on bone mass and bone turnover: the OFELY study. 1291 11

Bisphosphonates have been used with success in the treatment of osteoporosis, but oral therapy often lacks compliance. Here we report the results of clinical trial with aminobisphosphonate neridronate administered intravenously (i.v.). The study included 78 postmenopausal women with spine bone mineral density (BMD) at least -2.5 SD below peak. Patients were randomized to receive for 2 years either 50 mg i.v. neridronate bimonthly and 500 mg calcium plus 400 U vitamin D supplements daily (n=39) or calcium-vitamin D supplements alone (control group, n=39). Treatment was continued over 2 years with an additional 1 year follow-up of calcium-vitamin D supplements alone. Neridronate was well tolerated with the appearance of typical clinical signs of an acute phase reaction in only 3 of the patients after the first infusion. In the control group no significant changes in BMD or bone markers were observed. In the neridronate group BMD rose progressively at the spine rose up to 7.4% +/- 6.1% (SD) and at the femoral neck up to 5.8% +/- 8.2% (SD) at the end of the second year. In the succeeding follow-up these gains were maintained at both skeletal sites. Serum bone alkaline phosphatase (bone ALP) and serum type I collagen C-telopeptide (s-CTX) significantly decreased within 2 months. The bone ALP values reached a -35% plateau after 6 months, while s-CTX attained the lowest mean value (-47%) only by the end of the treatment with neridronate. Both bone markers returned almost to baseline values 1 year after treatment discontinuation. Treatment of postmenopausal osteoporosis with 50 mg i.v. neridronate bimonthly results in clinically relevant increases in BMD, among the largest so far observed with any other bisphosphonate.
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PMID:Intravenous intermittent neridronate in the treatment of postmenopausal osteoporosis. 1367 75

Peak bone mass, a determinant of osteoporosis at older ages, is affected by genetic, nutritional, lifestyle, and hormonal factors. Adolescence is a critical time for peak bone mass accrual, and boys achieve a higher peak bone mass than girls. We have reported vitamin D insufficiency in adolescents in our population, but its impact on bone remodeling is unclear. We systematically evaluated the impact of puberty, gender, and vitamin D status on biochemical markers of bone remodeling. Serum osteocalcin (OC), bone alkaline phosphatase (BAP), C-terminal telopeptide of type I collagen crosslinks (S-CTX), and 25 OH vitamin D were measured in 172 healthy students from private schools in the fall of 1999: There were 92 girls and 80 boys, age 10-17 years. In girls, all markers of bone turnover changed significantly with pubertal stage, were maximal at midpuberty, and decreased toward adult levels by Tanner stage V. Conversely in boys, these markers increased during early pubertal stages but had not normalized by Tanner stage V. Levels of all biochemical markers were significantly higher in boys compared to girls even after adjustment for age, body weight, and Tanner stage, P < 0.0001. In the subgroup of girls, those with vitamin D insufficiency, serum levels of BAP and S-CTX were highest. However, in multiple regression analyses, gender was the only consistent correlate of all three markers of bone remodeling. In conclusion, after adjusting for age, weight, and Tanner stages, changes in bone remodeling markers were most powerfully affected by gender. The latter may have important implications on gender differences in peak bone mass.
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PMID:Effect of gender, puberty, and vitamin D status on biochemical markers of bone remodedeling. 1449 58


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