bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of growth hormone on bone: Bone mineral density, trabecular bone volume, and alkaline phosphatase improve or are restored in the dwarf rat treated with growth hormone
Authors: Wright Nancy M. , Renault Josette , Hollis Bruce , Bell Norman H. , Key Lyndon L. 
Published: February 2010

Abstract
Studies were performed to determine whether serum total alkaline phosphatase (SAP), an index of bone formation; body weight; total body bone mineral density (BMD), measured by dual-energy X-ray absorptiometry; and tibial trabecular bone volume (TBV), measured by histomorphometry, are reduced in 2-week-old female sexually immature Lewis dwarf (dw/dw) rats (DW-CT, n = 9) with isolated growth hormone (GH) deficiency and, if so, whether recombinant human GH (rhGH), 200 μg/day subcutaneously for 4 weeks (DW-GH, n = 7), restores them. Studies were also performed to determine if 30% dietary restriction in 2-week-old female Lewis rats (LW-DR, n = 11) alters SAP, body weight, total BMD, or TBV compared with pair-fed controls (LW-CT, n = 7) given an ad libitum diet. Mean SAP (91 ± 5 versus 109 ± 5 U/l), body weight (102 ± 11 versus 140 ± 10 g), total BMD (88.5 ± 03 versus 101.4 ± 2.0 mg/cm2), and TBV (19.0 ± 1.0 versus 27.0 ± 1.4%) were significantly lower in DW-CT than in LW-CT animals, p &lt; 0.05. In DW-GH, rhGH significantly increased mean SAP (130 ± 7 U/l), body weight (133 ± 10 g), total BMD (92.7 ± 13), and TBV (24.0 ± 1.9) compared with DW-CT animals. Compared with LW-CT rats, mean body weight and TBV were not different, but mean SAP was significantly higher (p &lt; 0.01) and mean total BMD was significantly lower (p &lt; 0.003) in DW-GH rats. In LW-DR compared with LW-CT animals, dietary restriction significantly reduced mean body weight (p &lt; 0.05) but did not alter mean SAP, total BMD, or TBV. Thus, body weight, SAP, total BMD, and TBV were lower in DW-CT than in LW-CT rats. In the dose administered, SAP is markedly increased and reductions in body weight, total BMD, and TBV are completely or partially restored by treatment with rhGH in young female rats caused by isolated GH deficiency. Dietary restriction in young female rats with intact secretion of GH prevents weight gain but does not alter SAP, total BMD, or TBV compared with animals fed ad libitum.
The effects of risedronate on canine cancellous bone remodeling: Three-dimensional kinetic reconstruction of the remodeling site
Authors: Boyce R.W. , Paddock C.L. , Gleason J.R. , Sletsema W.K. , Eriksen E.F. 
Published: February 2010

Abstract
To investigate the dose-dependent effects of risedronate on cancellous bone remodeling, adult female beagle dogs were treated with either placebo, 0.1, 0.5, or 2.5 mg/kg/day of risedronate orally in an intermittent cyclic regimen (7 days on 21 days off), repeated three times. Iliac cancellous bone samples were subjected to histomorphometric analysis and three-dimensional (3-D) kinetic reconstruction of the remodeling site was performed. In the 0.1 mg/kg dose group, resorption and activation indices were no different from the placebo group. However, wall thickness was increased resulting in a positive bone balance at the level of the remodeling unit. In the 0.5 and 2.5 mg/kg dose groups, a dose-dependent reduction in activation frequency and tissue level bone formation was observed. Resorption rates were also significantly decreased, 60% and 80% for the 0.5- and 2.5-mg/kg groups, respectively. An approximate 25% reduction in final erosion depth was noted in both these groups. Analyses of the growth curves of the bone packet confirmed that the kinetics of the growth of a completed packet were different in the 0.5- and 2.5-mg/kg dose groups compared with placebo. These changes were associated with a significant increase in the final wall thickness in both groups indicating no net impairment of osteoblast function. These increases in wall thickness in combination with the reductions in final erosion depth in the 0.5 and 2.5 mg/kg groups resulted in a significant dose-dependent positive bone balance. This pharmacological profile suggests that risedronate may be of therapeutic utility in the treatment of metabolic bone diseases where reductions in activation frequency and resorptive cell activity at the level of the remodeling unit are a therapeutic goal.
Decreased bone density in inflammatory bowel disease is related to corticosteroid use and not disease diagnosis
Authors: Bernstein Charles N. , Seeger Leanne L. , Sayre James W. , Anton Peter A. , Artinian Lucy , Shanahan Fergus 
Published: February 2010

Abstract
Although corticosteroid therapy is associated with the development of osteopenia, it is unclear whether the cause of osteopenia in inflammatory bowel disease (Crohn's disease and ulcerative colitis) is related to corticosteroid therapy or other disease-related variables. Patients with Crohn's disease (a diffuse gastrointestinal disease) could have greater osteopenia than patients with ulcerative colitis because of small bowel disease and secondary malabsorption of calcium and vitamin D. A cross-sectional analysis of consecutive patients with Crohn's disease and ulcerative colitis was undertaken. Bone density was determined by measurements of the L2–L4 spine, the total hip, and Ward's triangle using dual energy X-ray absorptiometry (DXA). A number of clinical parameters were recorded prior to bone density evaluation and analyzed by univariate and subsequently multivariate analysis to determine possible predictors of osteopenia. Of the 26 patients with Crohn's disease, diminished bone density (a Z score of at least −1) was found at the hip in 64% and at the spine in 44%; and of the 23 patients with ulcerative colitis diminished bone density was found at the hip in 43% and at the spine in 48%. Among all the variables tested, only corticosteroid use was a statistically significant predictor of diminished bone density (p = 0.025 for the spine and hip and p = 0.005 for Ward's triangle). Disease diagnosis (Crohn's disease compared with ulcerative colitis) did not predict or correlate with diminished bone density. No obvious associations were seen between the measurements of any serum hormones or biochemistries and bone density, although the patients using corticosteroids had lower serum calcium levels than the nonusers. Separate multivariate analyses were performed for males and females. Corticosteroid use was statistically significantly associated with diminished bone density in females but not in males. All patients with inflammatory bowel disease (both Crohn's disease and ulcerative colitis), independent of whether or not they have small bowel disease, who have been using corticosteroids for long periods should have their bone density status investigated, since they have a high prevalence of diminished bone density and, therefore, are at risk for bone fractures. Further studies are required to sort out factors that may make bone density in females more sensitive to the effects of corticosteroids than that of males.
Prediction of fracture risk using axial bone mineral density in a perimenopausal population: A prospective study
Authors: Kröger Heikki , Huopio Jukka , Honkanen Risto , Tuppurainen Marjo , Puntila Eero , Alhava Esko , Saarikoski Seppo 
Published: February 2010

Abstract
Several prospective studies have shown that the bone mineral density (BMD) measured in the appendicular or axial skeleton has an inverse relationship with the risk of subsequent fractures. However, most of these studies have concentrated on relatively old age groups, and the usefulness of measuring BMD at the time of menopause has not been established. In the present study, BMD was measured at the lumbar spine and femoral neck by dual X-ray absorptiometry (DXA) in a random stratified population sample of 3222 perimenopausal women (mean age 53.4 years, range 47–59 years). These women were followed for fractures over a period of 2 years. The fractures reported by a postal inquiry were verified from medical records. Fractures sustained in motor vehicle accidents were excluded from the analyses. During a mean follow-up of 2.4 years, 183 fractures occurred in 168 women. Wrist (n = 47), ankle (n = 31), and rib (n = 28) were the most common sites of a fracture. Women in the lowest quartile of spinal BMD had a 2.9 times greater risk of fracture than those in the highest quartile. The respective risk increased 2.2 times from the lowest to the highest quartile of femoral BMD, respectively. The relative risk for suffering from any fracture per one SD decrease in BMD was 1.50 (95% CI; 1.27–1.76) for the spine and 1.41 (1.21–1.64) for the femoral neck. The present study demonstrates that bone mass is important in the pathogenesis of fractures even in perimenopausal women. We conclude that the axial BMD measurement at the time of menopause can be of use in predicting subsequent fracture risk.
Dual X-ray absorptiometry of the proximal femur: Normal european values standardized with the european spine phantom
Authors: Pearson J. , Dequeker J. , DR. Reeve J. , Felsenberg D. , Henley M. , Bright J. , Lunt M. , Adams J. , Curiel Diaz M. , Galan F. , Geusens P. , Jaeger P. , Kröger H. , Lips P. , Mitchell A. , Cano Perez R. , Pols H. , Rapado A. , Reid D.M. , Ribot C. , Schneider P. , Laval-Jeantet A.M. , Ruegsegger P. , Kalender W. 
Published: February 2010

Abstract
Measurements of the proximal femur by dual X-ray absorptiometry (DXA) are assuming increasing importance in clinical and epidemiological studies. However, different DXA manufacturers have adopted varying approaches to measuring the femoral neck and trochanter regions with the result that there is as yet no agreement on normal ranges and how to cross-calibrate between different machines. In this Concerted Action (of the EU's 2nd Framework Programme), 12 clinical centers in eight countries recruited a total of 855 female and 517 male Caucasian subjects who were judged to be free of conditions known to cause secondary osteoporosis and who had not been treated with drugs known to affect bone mass. The DXA machines used were made by Hologic, Lunar, and Norland. Each machine was cross-calibrated with the European Spine Phantom prototype designed by Kalender. All femoral neck and trochanter results were expressed as standardized values and were first examined for possible bias due to between-brand differences in choice of areas for measurement. On average, trochanter areas were similar between brands but Norland chose a narrower neck region for analysis. Bone mineral density (BMA or BMD g/cm) was log-normally distributed for all groups at the femoral neck but normally distributed at the trochanter in men and postmenopausal women. There were substantial between-center differences after cross-calibration in age-adjusted mean values at both sites and also in the rates of apparent bone loss with age and the amounts of scatter within populations about mean age-adjusted values. With the proviso that locally derived normal ranges would allow more accurate comparisons for clinical purposes, European normal ranges were derived for both neck and trochanter. Data obtained with the three individual brands of machine fitted these overall ranges well. Bone loss was apparent in premenopausal women at the femoral neck but not the trochanter. Postmenopausal women's data was somewhat better fitted by reference to years since menopause than to chronological age. This work provides a basis for conducting future epidemiological and clinical studies with more than one brand of machine as long as each individual subject, if measured consecutively, is measured on the same machine throughout.
The matrix Gla protein gene is a marker of the chondrogenesis cell lineage during mouse development
Authors: Luo Guangbin , D'Souza Rena , Hogue Deborah , DR. Karsenty Gerard 
Published: February 2010

Abstract
Matrix Gla protein (MGP) is, along with osteocalcin, a skeletal member of the family of extracellular mineral-binding Gla proteins. Although the precise function of these proteins remains obscure, circumstantial evidence suggests that they play a role in endochondral ossification. As a first step toward understanding MGP function we have performed a preliminary characterization of its promoter element and studied the developmental pattern of expression of this gene. DNA transfection experiments indicate that the mouse MGP promoter functions better in cells expressing the MGP gene than in cells that do not express the gene. During mouse development, MGP gene expression is detectable as early as day 10.5 of embryonic development (E10.5), before any skeletal structures are identifiable. In situ hybridization analysis shows that MGP mRNA is initially present at the mesenchymal epithelial interphase in lung and limb buds. As development proceeds, MGP gene is predominantly expressed in cells of the chondrocytic lineage in areas that will undergo endochondral ossification as well as in areas that will remain cartilaginous, such as the trachea and bronchi. In growth plate cartilage, MGP mRNA is present in resting, proliferative, and late hypertrophic chondrocytes. Surprisingly, MGP mRNA is absent from the early hypertrophic chondrocytes and from the osteoblasts. Finally, the MGP gene is expressed at a lower level in kidney medulla and uterus smooth muscle but not in brain, spleen, or heart during development. This study demonstrates that during development MGP gene expression occurs early and is predominant at the epithelial mesenchymal interfaces, principally of lung and limb buds, and in cells of the chondrocytic lineage. This finding raises the intriguing possibility that MGP may play distinct roles during embryogenesis and in the adult organism.
Ultrasound velocity through bone predicts incident vertebral deformity
Authors: Heaney R.P. , Avioli L.V. , Chesnut C.H. , Lappe J. , Recker R.R. , Brandenburger G.H. 
Published: February 2010

Abstract
We followed 130 postmenopausal women without evidence of vertebral deformity by lateral spine radiographs on entry into study for 2 years, and repeat spine radiographs were taken at the end of that time. Incident deformities occurring within this 2 year period were detected by two methods, a level-specific radiogrammetric approach and visual inspection by skilled clinicians. Fourteen incident deformities were detected by the radiogrammetric method, and 19 by the clinicians. Ultrasound transmission velocity was measured at the patella in each subject on entry. Values for ultrasound velocity were significantly correlated with incident fracture occurrence, with individuals having velocity values more than one standard deviation below the mean for the group exhibiting from 3.3 to 4.6 times the probability of incident fracture as individuals with velocity values more than one standard deviation above the mean. Thus, low values for ultrasound transmission velocity at the patella detect yet-unexpressed bony fragility at the spine and predict future fracture.
Sources of interracial variation in bone mineral density
Authors: Dr. Cundy Tim , Cornish Jill , Evans Margaret C. , Gamble Greg , Stapleton Joanne , Reid Ian R. 
Published: February 2010

Abstract
Many studies have demonstrated significant differences in bone mineral density between various racial groups. Although it has been suggested that differences in body weight contribute to such interracial variation, the artifactual effect of the skeletal size inherent in projectional absorptiometry methods has been largely ignored. We have measured bone mineral density by dual-energy X-ray absorptiometry in the lumbar spine and at three femoral sites in 200 premenopausal women of Chinese, Indian, European, or Polynesian origin (50 of similar mean age in each group). In the Chinese and Indian women the measured bone mineral density measurements (g/cm) were similar, but significantly less, at all sites, than those of European women (p ≤ 0.005). The European women were, however, significantly taller than both the Chinese and Indian women (p &lt; 0.0001), and when the scale artifact of absorptiometry was removed by dividing the measured bone mineral density either by the height of the subject, or by the square root of the area over which the X-ray beam was projected, then the differences in mean bone mineral density between the Chinese, Indian, and European women were almost completely eliminated. The Polynesian women were significantly more obese (as judged from mean body mass index) than all the other groups (p &lt; 0.0001) and had significantly greater bone mineral density at all sites than all the other groups both before (p &lt; 0.0001) and after (p &lt; 0.0001) correcting for the scale artifact. Analysis of covariance suggested that 10–40% of the remaining increase in bone density could be accounted for by their greater obesity, the balance representing a true interracial difference. This effect was most obvious in the lumbar spine and least evident at the femoral sites. We conclude that there is a true interracial difference in bone mineral density between Polynesians and the other races studied, and that this is increased further by the greater body weight of Polynesians. The differences between Europeans and Asians are substantially attributable to a measurement artifact arising from the smaller skeletal dimensions of Asians. This needs to be borne in mind by clinicians assessing bone density in Asian patients.
Rat tail suspension reduces messenger RNA level for growth factors and osteopontin and decreases the osteoblastic differentiation of bone marrow stromal cells
Authors: Zhang Renwen , Supowit Scott C. , Klein Gordon L. , Lu Zhaofeng , Christensen Monique D. , Lozano Renaud , Dr. Simmons David J. 
Published: February 2010

Abstract
We previously reported that bone marrow stromal cells produce insulin-like growth factors (IGF-I and -II), and that medium conditioned by marrow stromal cells stimulates osteoblast proliferation in vitro. The present study employed the rat tail-suspension model to unload the hindlimbs. It was designed to test the hypothesis that the development of osteopenia or osteoporosis could be due to a deficit in the osteogenic function of marrow stromal cells. Although tail suspension suppressed body weight during the first 3 days of an 11-day pair-fed study, the overall weight gain recorded by these animals was normal. Nevertheless, bone growth was inhibited by suspension. Similarly, the total adherent marrow stromal cell population harvested from the femurs and tibias was decreased by tail suspension, and only half the normal number of fibroblastic stromal cell colonies grew when they were cultured. The proliferation of alkaline-phosphatase-positive cells in the stroma was also inhibited. Northern hybridization revealed that the messenger RNA level for transforming growth factor-β2 and IGF-II in stromal cell was reduced by tail suspension. The production of IGF-II by marrow stromal cells was also decreased. The steady-state level of five different transcript sizes of IGF-I mRNA was altered differentially by tail suspension. Osteopontin mRNA was also reduced in marrow stromal cells from tail-suspended rats compared with the normal rats. These data suggest that skeletal unloading not only alters the mRNA level for growth factors and peptide production, but also affects the proliferation and osteogenic differentiation of marrow stromal cells. These changes may be responsible for the reduced bone formation in osteopenia and osteoporosis.
Differential effects of swimming versus weight-bearing activity on bone mineral status of eumenorrheic athletes
Authors: Taaffe Dennis R. , Snow-Harter Christine , Connolly Declan A. , Robinson Tracey L. , Brown Monte D. , Marcus Robert 
Published: February 2010

Abstract
To examine the role of skeletal loading patterns on bone mineral density (BMD), we compared eumenorrheic athletes who chronically trained by opposite forms of skeletal loading, intensive weight-bearing activity (gymnastics, n = 13), and nonweightbearing activity (swimming, n = 26) and 19 nonathletic controls. BMD (g/cm) of the lumbar spine, femoral neck, trochanter, and whole body was assessed by dual energy X-ray absorptiometry (DXA). Subregion analysis of the whole body scan permitted BMD evaluation of diverse regions. Swimmers were taller (p = 0.0001), heavier (p &gt; 0.005), and had a greater bone-free lean mass (p &lt; 0.001) than gymnasts and nonathletic controls. When adjusted for body surface area, there was no difference in lean mass between swimmers and gymnasts, and both were higher than controls (p &lt; 0.01). Gymnasts had a lower (p &gt; 0.005) fat mass than swimmers and controls. There were no group differences for spine or whole body BMD, but gymnasts had higher spine BMD corrected for body mass than either swimmers or controls. Gymnasts (1.117 ± 0.110) had higher femoral neck BMD than controls (0.974 ± 0.105), who were higher than swimmers (0.875 ± 0.105) (p = 0.0001). This result still applied when BMD was normalized for body weight and bone size. Trochanter BMD of gymnasts (0.898 ± 0.130) was also higher than controls (0.784 ± 0.097) and swimmers (0.748 ± 0.085) (p = 0.0002), and remained higher when corrected for body mass. Whole body BMD normalized for body mass or bone size was significantly higher in gymnasts than in swimmers. Subregion analysis revealed arm BMD of gymnasts was greater than swimmers and controls (p &gt; 0.01), and gymnasts' leg BMD was higher than that of swimmers (p &gt; 0.05). These results suggest that the intensive weight-bearing activity characteristic of gymnastics is a powerful osteogenic stimulus and that long-term nonweightbearing training that incorporates forceful muscular contractions, as in swimming, confers no beneficial skeletal effects on bone mass of young women.
Mineralization of alkaline phosphatase-complexed collagen implants in the rat in relation to serum inorganic phosphate
Authors: Van Den Bos T. , Oosting J. , Everts V. , Beertsen W. 
Published: February 2010

Abstract
The present study was designed to determine the relationship between mineralization of collagenous matrices and serum levels of calcium and inorganic phosphate. Collagen slices were prepared from bovine dentin or cortical bone and complexed with varying amounts of intestinal alkaline phosphatase (ALP). The enzyme was added to induce de novo mineralization. The ALP-complexed slices were implanted subcutaneously over the skull and in the dorsolateral aspect of the abdominal wall in female Wistar rats of various ages (5-, 10-, 20-, or 35-week-old) and in young male rats fed on a low-P diet. After 1–4 weeks, the implants were removed and analyzed for calcium and phosphate content. In addition, serum levels of calcium and phosphate (total and inorganic) were determined. It was shown that the highest mineral influx occurred in the younger rats (which were also highest in serum Pi), whereas almost no mineral uptake occurred in the older ones. Also in rats fed on a low-P diet (which were low in serum Pi), a strongly decreased mineral influx was noted. In all animal groups a positive correlation was found between the degree of mineralization and serum Pi. No distinct relationship was found between serum Ca/organic phosphate levels and mineral influx in the implants. In vitro incubation of ALP-collagen conjugates in serum from younger and older rats confirmed our view that serum Pi, besides local levels of ALP, is important in de novo mineral deposition. For accretion of mineral in partially remineralized collagenous carriers, ALP activity was not required.