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)

It is still uncertain whether bone mass and bone turnover are completely normalized after treatment of hyperthyroidism. The aim of the present investigation was to determine bone mass, bone turnover, body composition, and calcium homeostasis in former hyperthyroid patients who had been euthyroid for at least 4 years following combined medical therapy. Thirty-nine former hyperthyroid patients and 67 normal sex- and age-matched controls participated. Height, body weight, and body composition were similar in the two groups. All patients were euthyroid. However, serum FT3I (free T3-index) was reduced by 9% (p < 0.01) in the patients compared to controls, serum FT4I was normal, while serum TSH was nonsignificantly reduced by 39%. No significant differences were observed between patients and controls with respect to total or regional bone mineral content (BMC) or density (BMD). The former hyperthyroid patients had slightly higher serum calcium (2.35 +/- 0.06 vs. 2.32 +/- 0.07 mmol/L, p < 0.05) and lower serum phosphate (1.15 +/- 0.15 vs. 1.24 +/- 0.15 mmol/L, p < 0.01) than their controls. Renal excretion of calcium and serum levels of magnesium, 1,25-vitamin D and intact PTH were unchanged. Renal excretion of pyridinoline was increased by 30% (p < 0.05) in the patients, whereas the remaining resorptive markers, renal excretion of hydroxyproline and deoxypyridinoline and serum cross-linked carboxy-terminal teleopeptide of type I collagen (ICTP) were unaltered. Among the formative bone markers the average serum carboxy-terminal propeptide of human type I procollagen (PICP) level was 12% lower (p < 0.05) than in the control group, whereas serum levels of osteocalcin and total and bone alkaline phosphatase were normal. In conclusion, former hyperthyroid patients treated by combined medical therapy have normal bone mineral content and density in spite of minor variations in thyroid hormones and skeletal homeostasis.
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PMID:Bone mass, bone turnover, body composition, and calcium homeostasis in former hyperthyroid patients treated by combined medical therapy. 883 21

Untreated hyperthyroidism is characterized by increased bone turnover with loss of bone and bone mineral. The aim of the present investigation was to evaluate the reversibility of these changes by measuring bone mass, bone turnover, and calcium homeostasis in surgically treated former hyperthyroid patients who had been euthyroid for at least 6 years. Sixty euthyroid former hyperthyroid patients and 94 normal sex- and age-matched controls participated. Heights and body weights and composition were similar in the two groups. In the thyroxine substituted patients (n = 27) both serum T4 and serum free T4-index (S-FT4I) were increased (p < 0.001) compared to the normal controls as well as the nonsubstituted patients. In the nonsubstituted patients. In the nonsubstituted patients (n = 33), serum TSH was increased (p < 0.001) compared to the normal controls. No significant differences were observed between substituted and nonsubstituted patients and normal controls with respect to serum T3, serum free T3-index (S-FT3I), or regional or total bone mineral content (BMC) and density (BMD) values. Serum levels of calcium, phosphate, magnesium, intact PTH, and renal excretion of calcium were unchanged. However, serum levels of 1,25-dihydroxy- and 25-hydroxyvitamin D were reduced. Urinary excretion of hydroxyproline was increased by 16% (p < 0.05), but serum cross-linked carboxy-terminal teleopeptide of type I collagen (ICTP) was decreased by 11% (p < 0.01). Urinary excretion of collagen cross-links was normal. Serum levels of osteocalcin, carboxy-terminal propeptide of human type I procollagen (PICP), and total and bone alkaline phosphatase were all normal. In conclusion, surgically treated former hyperthyroid patients have normal bone mass, bone turnover, and calcium homeostasis in spite of minor variations in thyroid hormones and vitamin D metabolites.
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PMID:Bone mass, bone turnover, calcium homeostasis, and body composition in surgically and radioiodine-treated former hyperthyroid patients. 883 22

Sodium Fluoride (NaF) is the only medication so far clinically available with a bone formation stimulating property, through its peculiar mitogenic dose-dependent action on the osteoblast cell line. Bone strength is commensurate to bone mass, and in a condition with fragility fractures, like osteoporosis, it seems logical to restore bone mass without weakening bone strength. However, as with any active drug. NaF therapy requires adhesion to elementary rules if drawbacks are to be prevented. A first mandatory rule is not to prescribe NaF without calcium supplementation, if bone loss at the appendicular skeleton is to be avoided; to prevent this, the availability of monofluorophosphate (MFP), containing the fluoride and calcium salts in the same preparation has enhanced the compliance to calcium supplementation. A second rule is not to give supraphysiological doses of vitamin D, for the same reason. Third, if one wants to avoid a calcium shift from cortical to trabecular bone and osteomalacia, one should use small doses of NaF, of the order of 50 mg/day. With this in mind, the bioavailability of the drug has to be taken into account, particularly its gastrointestinal absorption which is dramatically enhanced if a plain non entericoated (EC) capsule is used, as compared to that of an EC tablet with the same face value. Too much NaF is deleterious to bone, a fact known for years. Already in 1972, it was noted that in all patients receiving 60 mg or more of NEC NaF, daily, morphologically abnormal bone developed and which appeared irregular and contained areas of incompletely mineralized bone. The bone was histologically and microradiographically normal in patients receiving 45 mg or less of NEC NaF/day. Fourth, NaF therapy is contraindicated in renal insufficiency owing to an enhanced retention in the skeleton. NaF is, however, by no means the ideal medication, because its therapeutic window is narrow. It has many bothersome drawbacks, and notably it is irritating for the gastric mucosa, a hazard which may be partly circumvented by the use of an Ec or slow release tablet. Furthermore, peripheral stress fractures may occur, and, in our experience, they were seen in 17% of patients, almost exclusively in females with a low lumbar BMD. Their occurrence should be curtailed by not allowing an increase in alkaline phosphatase activity of more than 50%. This is a relatively benign complication, because no stress fracture degenerated into a complete fracture. In all cases, the stress fractures healed after a transitory drug discontinuation. If there is some concern about cortical bone, NaF therapy may be associated with an antiresorber like estrogens which will prevent any further bone loss, and does not impair the response to NaF. NaF therapy should be reserved for patients suffering chiefly from trabecular osteoporosis and should be avoided in senile osteoporosis, because of a frequently impaired renal function. Currently, we would recommend in clinical practice a daily dose of 50 mg EC-NaF or 150 mg Ca-MFP as the therapy of involutional osteoporosis in women, reserving the dose of 75 mg EC-NAF or 200 mg MFP for males or female patients resistant to lower dose. The therapy should be maintained for 2 to 3 years, or more, according to the bone response, taking into account that patients with the vertebral crush fracture syndrome have lost on average 30%, as compard to the young adult mean.
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PMID:Fluoride therapy of type I osteoporosis. 884 58

In this study bone mineralization was evaluated using dual energy x-ray absorptiometry (DEXA), which measured regional bone mineral density [BMD (g/cm2)] at two skeletal sites, the lumbar spine and the femur, in 33 patients (15 male, 18 female) undergoing continuous ambulatory peritoneal dialysis (CAPD) with no history of chronic disease or medications affecting bone. The biochemical profile included measurements of plasma levels of calcium, phosphorus, alkaline phosphatase, and intact parathyroid hormone (iPTH). We did not find any statistically significant difference or correlation between BMD and the examined parameters, except for the lower BMD values in the female population. Because of the reported findings of significantly lower PTH levels in CAPD patients with low turnover bone disease (adynamic bone disease) and the higher prevalence in CAPD than in hemodialysis patients, we tried to evaluate any correlation between BMD and iPTH levels in CAPD patients that were separated into two groups: group A (iPTH < 200 pg/mL), 13 patients, and group B (iPTH > 200 pg/mL), 20 patients. Data analysis revealed a negative correlation between PTH levels and BMD values (r = -0.66, p = 0.014) as PTH and serum calcium (r = -0.77, p = 0.002) only in group A. No other statistically significant changes were observed. These findings suggest that there is a favorable influence of CAPD modality on bone mineralization, while no special DEXA findings are representative of the possible appearance of adynamic bone disease.
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PMID:Evaluation of bone mineral density in CAPD patients with dual energy X-ray absorptiometry. 886 13

In order to evaluate whether changes of adrenal steroid serum levels occurring during the prepubertal period influence the degree of osteopenia, dehydroepiandrosterone sulfate (DHEAS) was longitudinally monitored as marker of the onset of adrenarche. Fifteen thalassemic patients, 9 girls (Group 1) and 6 boys (Group 2), with chronological age (CA) from 6.1 to 10.3 years and bone age (BA) from 6 to 9.6 years, were studied. Two observations, 14 months apart, were made. All patients had no pubertal signs according to Tanner during the period of observation, and auxological data (height, BMI and height velocity) were evaluated in respect to bone age. There was a statistically significant difference between the two groups for serum DHEAS, BGP serum levels, height velocity and bone mineral density expressed as standard deviation score (BMDsds) in respect to both bone age and height age (the latter was calculated in order to eliminate the influence of height on BMD). Alterations of bone metabolism were excluded by determination of calcium, phosphorus, alkaline phosphatase activity, parathormone, 25-OH-D3, IGF-I serum levels, all these values being normal. In conclusion, our data show that a delayed adrenarche occurs in thalassemic boys which is correlated with a severe degree of osteopenia, even though the relationship between them is not yet established.
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PMID:Can adrenarche influence the degree of osteopenia in thalassemic children? 888 50

Isolated hypogonadotropic hypogonadism (IHH) presents with delayed puberty in the late teens or early twenties, with a period of testosterone deficiency during active growth. The aims of the study were to determine 1) whether long term treatment of IHH results in normalization of bone density (BMD) and bone turnover, and 2) whether BMD and bone turnover respond to increasing doses of hCG. We studied 10 men, aged 26-46 yr, with IHH who were treated with hCG or testosterone esters (Sustanon) for 2-22 yr, with age at the start of treatment between 17-29 yr, and 10 age- and body weight-matched normal men as a control group. At baseline, lumbar spine, femoral neck, trochanter, and Ward's triangle BMD values were decreased, and serum bone Gla-protein, bone alkaline phosphatase, and urinary pyridinoline, deoxypyridinoline, and N-terminal telopeptide of type I collagen were increased compared with control values (by paired t test, P = 0.02, 0.03, 0.01, 0.05, 0.002, 0.02, 0.02, 0.007, and 0.006, respectively). The age at initial therapy was significantly correlated with total body BMD (r = -0.73; P = 0.017) and lumbar spine BMD (r = -0.756; P = 0.0097). Serum free testosterone was correlated with total body and trochanter BMD (r = 0.635; P = 0.048 and r = 0.629; P = 0.05), and serum free estradiol was correlated with total body and trochanter BMD (r = 0.641; P = 0.045 and r = 0.634; P = 0.048). Six of the 10 patients were recruited for a longitudinal study in which the dose of hCG was increased monthly from 2000 i.u. twice per week to 6000 i.u. twice per week. After increasing doses of hCG, levels of serum testosterone and estradiol and total body BMD increased significantly (by paired t test P = 0.001, 0.003, and 0.01, respectively). Serum bone Gla-protein levels increased by the first month and then decreased (paired t test, corrected by Bonferroni's method). Serum bone alkaline phosphatase and urinary N-terminal telopeptide of type I collagen/creatinine levels decreased significantly after increasing the dose of hCG. We conclude that patients with IHH who have serum testosterone within the laboratory reference range may require a higher dose of hCG to normalize BMD and bone turnover.
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PMID:Treatment of isolated hypogonadotropic hypogonadism effect on bone mineral density and bone turnover. 902 72

We examined the effects of nandrolone decanoate (25 mg im every 3 weeks) on bone mass, serum biomarkers, and bone histomorphometric endpoints in 52 female cynomolgus macaques randomized into four treatment groups: (1) sham-ovariectomized (sham); (2) ovariectomized + placebo for 2 years (ovx); (3) ovx + nandrolone decanoate for 2 years (Nan); and (4) ovx + nandrolone decanoate beginning 1 year after ovx (dNan). Serum alkaline phosphatase (ALP), osteocalcin, and tartrate-resistant acid phosphatase (TRAP) were assayed every 3 months, and X-ray densitometry of the lumbar spine was done every 6 months. Fluorochrome-labeled iliac biopsies collected at baseline and 1 year, and lumbar vertebrae and midshaft femur collected at 2 years, were evaluated histomorphometrically. Body weight increased over 50% with administration of nandrolone. After 2 years, ovx animals had lower spinal BMC and BMD than all other groups. Ovx animals also had higher bone turnover rates than all other groups, as indicated by higher levels of the serum and urine biomarkers, and by at least twofold higher label-based bone formation rates in the femur diaphysis and in both cancellous and cortical bone of the ilium and vertebral bodies. Nandrolone-treated animals had similar serum estradiol levels as the sham animals, presumably due to conversion of endogenous or exogenous androgens. The effects of nandrolone on bone in this experiment are consistent with estradiol action and may be attributable to the increased serum estradiol. Despite >50% higher body weight, nandrolone-treated, ovariectomized animals did not have higher bone mass than sham animals.
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PMID:The androgenic anabolic steroid nandrolone decanoate prevents osteopenia and inhibits bone turnover in ovariectomized cynomolgus monkeys. 910 56

Ipriflavone (i.p.) positively affects bone density in postmenopausal osteoporosis, primarily by inhibiting bone resorption. Using in vitro models of human osteoblast differentiation, we have observed that i.p. and some of its metabolites stimulate the expression of bone sialoprotein, decorin, and type I collagen, and facilitate the deposition of mineralized matrix. This suggests that i.p. may stimulate bone formation in addition to its antiresorptive activity. To assess whether these effects translate into an improved bone "quality" in vivo, we measured biomechanical properties, mineral composition, and crystallinity of femurs of 12-week-old, male, Sprague-Dawley rats treated with i.p. for 1 month. i.p. significantly decreased vibration damping, an index of strain energy loss. Because vibration damping increases as bone porosity increases, the results indicate that i.p.-treated bones acquired a higher capacity to withstand dynamic stress. In fact, 1.5-fold higher energy was required to fracture femurs of i.p.-treated rats after a single supramaximal impact. i.p. also increased BMD, assessed by both volume displacement and ash analysis, whereas the relative contents of Ca, P, and Mg in the ashes were not affected. Thus, no gross abnormalities in mineral composition of bone occurred after i.p. administration. As a measure of bone crystallinity, X-ray diffraction analysis was performed. The broadening parameter beta 1/2 for the (310) and (002) reflections was not significantly different between i.p.-treated and control animals. Similarly, there were no differences in serum levels of Ca, Mg, alkaline phosphatase, and type I collagen telopeptides between treated and control animals at the end of the study. Therefore, 1-month treatment with i.p. increased bone density and improved the biomechanical properties of adult male rat bones without altering mineral composition or bone crystallinity.
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PMID:In vitro and in vivo effects of ipriflavone on bone formation and bone biomechanics. 926 10

Recent work has demonstrated differences in femoral bone mineral density between two common inbred strains of mice, C3H/HeJ (C3H) and C57BL/6J (B6), across a wide age range. To investigate one possible mechanism that could affect acquisition and maintenance of bone mass in mice, we studied circulatory and skeletal insulin-like growth factor-I (IGF-I) and femoral bone mineral density (F-BMD) by pQCT in C3H and B6 progenitor strains, as well as serum IGF-I obtained from matings between these two strains and mice bred from subsequent F1 intercrosses (F2). Serum IGF-I measured by radioimmunoassay was more than 35% higher in virgin progenitor C3H than virgin B6 at 1, 4, 8, and 10 months of age, and in 8-month-old C3H compared with B6 retired breeders (p < 0.001). In the progenitors, there was also a strong correlation between serum IGF-I and serum alkaline phosphatase (r = 0.51, p = 0.001). In the 4 month F1 females IGF-I levels and F-BMD were intermediate between C3H and B6 progenitors. In contrast, groups of F2 mice with the highest or lowest BMD also had the highest or lowest serum IGF-I (p = 0.0001). IGF-I accounted for > 35% of the variance in F-BMD among the F2 mice. Conditioned media from newborn C3H calvarial cultures had higher concentrations of IGF-I than media from B6 cultures, and cell layer extracts from C3H calvariae exhibited greater alkaline phosphatase activity than cultures from B6 calvarial cells (p < 0.0001). The skeletal content of IGF-I in C3H tibiae, femorae, and calvariae (6-14 weeks of age) was also significantly higher than IGF-I content in the same bones of the B6 mice (p < 0.05). These data suggest that a possible mechanism for the difference in acquisition and maintenance of bone mass between these two inbred strains is related to systemic and skeletal IGF-I synthesis.
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PMID:Circulating and skeletal insulin-like growth factor-I (IGF-I) concentrations in two inbred strains of mice with different bone mineral densities. 927 85

The aim of this study was to compare urinary galactosylhydroxylysine (GHyl) and deoxypyridinoline (d-Pyr) as biochemical markers of bone resorption in post-menopausal women treated and untreated with estrogen and cyclic etidronate. Fasting urinary GHyl, D-Pyr, pyridinoline, serum osteocalcin and total alkaline phosphatase were measured in three subgroups, i.e. post-menopausal women undergoing hormone replacement therapy, untreated post-menopausal women and post-menopausal women with low BMD treated with disodium etidronate. The results indicated that GHyl did not significantly discriminate between untreated post-menopausal women and estrogen replated ones unless an osteoporotic untreated group was selected. d-Pyr and GHyl showed similar performances when their values after bisphosphonate treatment were compared to those found in untreated post-menopausal women, thus suggesting that both markers were equal in their ability to detect the bone response to cyclic etidronate administration. This observation further proves the statement that GHyl is prone to confounding factors under estrogen therapy but it is adequate as is d-Pyr in monitoring the bone response to bisphosphonate treatment.
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PMID:A comparative study on biochemical markers of bone collagen breakdown in post-menopausal women. 936 68


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