bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Effects of Smoking on Bone Mass and the Rates of Bone Loss Among Elderly Japanese-American Men
Authors: Vogel John M. , Davis James W. , Nomura Abraham , Wasnich Richard D. , Ross Philip D. 
Published: April 2006

Abstract
Bone density and bone loss rates were examined among Japanese-American men categorized as current cigarette smokers, past smokers, and nonsmokers. The design included a retrospective study of smoking and bone density and a prospective study of current smoking and bone loss rates. The mean length of follow-up was 5 years; the setting was the island of Oahu. The subjects included 1303 men in the Hawaii Osteoporosis Study, 51–82 years old at their initial examination. Twenty percent were current smokers, 45% past smokers, and 35% had never smoked. Their bone density was measured at the distal and proximal radius and calcaneus using single photon absorptiometry. Compared with never smokers, current and past smokers had significantly lower bone density, especially in the predominantly cancellous calcaneus (4.8 and 4.3% lower, respectively) and partially trabecular distal radius (1.8 and 3.3% lower, respectively). The magnitude of the smoking effect was linked strongly to the duration of smoking and also to the number of cigarettes smoked. Bone loss rates subsequent to the initial measurement were greater in the current smokers than the never smokers (20.5, 27.2, and 9.7% greater at the calcaneus, distal, and proximal radius, respectively) but the differences did not achieve significance. Smokers of more than one pack per day had 32.0, 77.6, and 30.7% greater loss rates than never smokers in these same sites; the difference achieved significance at the distal radius. The results from the distal radius suggest that these smokers may increase their fracture risk 10–30% per decade of smoking. The adverse effects of smoking appeared to be greater in cancellous than cortical bone.
Short-Term and Long-Term Fracture Prediction by Bone Mass Measurements: A Prospective Study
Authors: Dr. Huang Chun , Ross Philip D. , Wasnich Richard D. 
Published: April 2006

Abstract
Prospective and cross-sectional studies have demonstrated that bone mass predicts fracture risk. However, most prospective studies have been limited to a few years of follow-up. We investigated the long-term associations of bone mass with vertebral fractures using longitudinal data collected from more than 500 postmenopausal Japanese-American women in the Hawaii Osteoporosis Study. New vertebral fractures were identified during an average of 2.7 years between 1992 and 1995. Short-term fracture prediction was evaluated using bone mass (spine, calcaneus, distal radius, and proximal radius) measured at the beginning of follow-up. Long-term prediction was evaluated using bone mass measured before the follow-up period (11 years earlier for nonspine bone mass and 8 years earlier for spine). All four bone mass measurements were significant predictors of vertebral fractures identified during the subsequent 2.7 years (short-term prediction), with odds ratios (ORs) ranging from 1.5 to 1.9. The ORs for long-term prediction were slightly lower in magnitude, but the confidence intervals overlapped the short-term ORs considerably, suggesting that both long-term and short-term associations are similar in magnitude. Furthermore, cross-sectional analyses based on bone mass measurements performed at the end of follow-up (after fractures had occurred) yielded results similar to those based on prospective data (bone mass measured prior to fractures), suggesting that the relatively quick and inexpensive cross-sectional studies are useful for preliminary evaluations of new bone mass measurement techniques. The results suggest that bone mass measurements made up to 11 years earlier can predict vertebral fractures almost as well as measurements made more recently.
Effect of Locally Infused IGF-I on Femoral Gene Expression and Bone Turnover Activity in Old Rats
Authors: Wakisaka Atsuhiko , Tanaka Hiroshi , Barnes Janice , Liang C. Tony 
Published: April 2006

Abstract
Previously, we showed that the age-dependent deficit in bone formation activity can be attributed in part to a decline in local expression of insulin-like growth factor I (IGF-I) and altered mitogenic response of old osteoprogenitor cells to IGF-I. To establish the cellular basis for using IGF-I as a possible therapeutic agent for osteoporosis, we examined the effect of locally infused (50 ng/day for 14 days) on the expression of osteoblast-related genes in femurs of old rats. Northern and dot blot analyses showed that the expression of procollagen (I), osteopontin, alkaline phosphatase, and osteocalcin was increased 0.4- to 1.5-fold in IGF-1–treated femurs as compared with control femurs. Histomorphometric analyses were carried out in parallel experiments to assess the changes in bone remodeling activity. Trabecular bone volume, trabecular number, and trabecular thickness were increased 56%, 29%, and 23%, respectively, whereas trabecular separation was reduced 26% by IGF-1 treatment. IGF-I treatment increased significantly the osteoid volume, osteoid surface, osteoblast number, and osteoblast surface. Mineralizing surface and mineral apposition rate, kinetic indices of bone formation, were also stimulated by IGF-I treatment. The bone formation rate was stimulated 81% in IGF-I–treated femurs as compared with control femurs. In contrast, eroded surface and osteoclast surface, parameters associated with bone resorption, were not affected by IGF-I treatment. These findings suggest that local administration of IGF-I into femurs of old rats can stimulate the expression of matrix proteins and improve trabecular bone status by stimulating bone formation without any appreciable effect on bone resorption.
Modulation of Osteoclast Function by Adenovirus Vector-Induced Epidermal Growth Factor Receptor
Authors: Tanaka Sakae , Takahashi Tokiharu , Takayanagi Hiroshi , Miyazaki Tsuyoshi , Oda Hiromi , Nakamura Kozo , Hirai Hisamaru , Kurokawa Takahide 
Published: April 2006

Abstract
We have explored the use of adenovirus vector-mediated gene transfer to introduce foreign genes into osteoclasts, terminally differentiated cells responsible for bone resorption. A replication-deficient adenovirus vector that contains a reporter gene encoding β-galactosidase efficiently infected human osteoclast-like cells (OCLs) derived from human giant cell tumors and mouse OCLs formed in vitro. We then constructed an adenovirus vector carrying human epidermal growth factor receptor (EGFR) cDNA (Ax1CAhEGFR) and introduced the EGFR gene into mouse OCLs. Clear induction of EGF receptor was detected in Ax1CAhEGFR-infected OCLs (EGFR-OCLs) by immunocytochemistry and immunoblotting, and EGF stimulation induced rapid tyrosine phosphorylation of several proteins including EGF receptor itself. Large vacuoles appeared in EGFR-OCLs in response to EGF treatment, and pit-forming activity by EGFR-OCLs was dose-dependently suppressed by recombinant human EGF. In addition, survival of EGFR-OCLs was prolonged by EGF. No expression of EGF receptor or effects of EGF were observed in noninfected OCLs or control vector-infected OCLs. These results suggest that adenoviral vectors are useful for modulating osteoclast function by introducing foreign genes into osteoclasts and that they will be a good means of gene therapy of metabolic bone diseases.
The Reproducibility of Ultrasound Bone Measures in a Triethnic Population of Pregnant Adolescents and Adult Women
Authors: Sowers M. , Jannausch M. , Scholl T. , Schall J. 
Published: April 2006

Abstract
We used bone ultrasound technology with its measurement of attenuation (broadband ultrasound attenuation [BUA] as dB/MHz) and sound velocity (speed of sound as m/s) for assessing the quantitative ultrasound index (QUI) summary measure in a triethnic population of 280 pregnant women. The study purpose was to describe the reproducibility of the ultrasound technology and determine if the correlations of age, weight, and ethnicity with the bone status measures in this population are consistent with the correlations of age, weight, and ethnicity that have been reported with other technologies that measure bone mass. We evaluated the first 280 women enrolled in our longitudinal study of lead turnover from maternal bone during pregnancy and lactation. Enrollees were pregnant, aged 12–29 years, and self-classified as black, white, or Hispanic. Bone ultrasound was measured twice at entry to prenatal care, which, on average, was at 14 weeks gestation. Reproducibility was described with intraclass correlations and the standard error of measurement. Age, weight, and ethnicity were associated with bone status measures using Spearman correlations and generalized linear models. The reproducibility of the summary bone measure, QUI, was high (96–97%). Variation in age and ethnicity did not alter reproducibility; however, the reproducibility of the attenuation measure (BUA as dB/MHz) lessened with increasing weight, declining from 95% to 89%. Since this attenuation is included in the summary QUI measure, there was a slight, and nonsignificant, decline in QUI reproducibility (from 97% to 96%) as women increased in size. There were no statistically significant differences in mean bone ultrasound measures according to age, where ages ranged from 12–29 years. Women who categorized themselves as black had, on average, an 8.5% greater QUI than did women who classified themselves as Hispanic or white. There were no significant pair-wise differences in mean ultrasound measures of bone between women classifying themselves as Hispanic or white. The use of ultrasound is a highly reproducible measure to assess bone characteristics in a population of pregnant adolescent and young adult women and its summary measure of bone mass is correlated with ethnic as well as body size characteristics.
Parathyroid Hormone Induces Expression of the Inducible cAMP Early Repressor in Osteoblastic MC3T3-E1 Cells and Mouse Calvariae
Authors: Tetradis Sotirios , Nervina Jeanne M. , Nemoto Ken , Dr. Kream Barbara E. 
Published: April 2006

Abstract
Parathyroid hormone (PTH) regulates gene expression in skeletal osteoblasts mainly through the cAMP–protein kinase A (PKA) pathway. In neuroendocrine cells, activation of the cAMP–PKA signaling pathway leads to induction of the inducible cAMP early repressor (ICER), which is transcribed from an intronic promoter of the CREM gene and acts as a transcriptional repressor. To investigate whether PTH induces ICER expression in osteoblastic cells, RNA from MC3T3-E1 cells was subjected to reverse transcriptase-polymerase chain reaction using primers spanning the ICER sequence. Amplified products were subcloned, sequenced, and used as a probe for Northern blot analysis. In MC3T3-E1 cells, PTH induced ICER mRNA levels, which peaked at 2 h and declined to baseline by 8 h. Cycloheximide caused superinduction of ICER mRNA in response to PTH. In cultured mouse calvariae, PTH also induced ICER mRNA accumulation, which peaked at 2 h and returned almost to baseline by 10 h. Overexpression of ICER IIγ decreased both baseline and PTH-stimulated prostaglandin G/H synthase 2 promoter activity in MC3T3-E1 cells. The induction of ICER represents a novel mechanism by which PTH regulates gene expression in osteoblastic cells.
Inhibition of BMP Receptor Synthesis by Antisense Oligonucleotides Attenuates OP-1 Action in Primary Cultures of Fetal Rat Calvaria Cells
Authors: Yeh Lee-Chuan C. , Betchel Karen P. , Lee John C. 
Published: April 2006

Abstract
Osteogenic protein-1 (OP-1 or bone morphogenetic protein-7 [BMP-7]) stimulates osteoblast differentiation in vitro and induces bone formation in vivo. BMPs exert their effects through complex formation with a heterodimeric receptor composed of a type I and a type II polypeptide. In the present study, mRNAs for three BMP subtype I receptors (ActR-I, BMPR-IA, and BMPR-IB) and one BMPR-II receptor were detected by Northern analysis in two human osteosarcoma cell lines (SaOS-2 and TE85) and in the primary cultures of fetal rat calvaria (FRC) cells. OP-1 affected the steady-state mRNA levels of these receptors differently among these cell types. To study the role of each receptor type in OP-1 action in FRC cells, receptor synthesis was inhibited by antisense oligonucleotides. Inhibition of receptor synthesis was confirmed by immunoprecipitation of radiolabeled cellular proteins with specific antibodies. The osteogenic action of OP-1 was measured by alkaline phosphatase (ALP) activity and mineralized bone nodule formation in FRC cells. Results showed that inhibition of synthesis of a single subtype I receptor alone did not affect significantly the OP-1–stimulated ALP activity. Inhibition of BMPR-II synthesis reduced the OP-1–stimulated ALP activity by about 50%. Inhibition of synthesis of any one of the type I receptor plus the BMPR-II receptor did not reduce the OP-1–stimulated ALP activity significantly beyond that observed by inhibition of BMPR-II alone. Under these conditions, nodule formation was affected similarly, thus supporting the observations made with the ALP measurements. The present results suggest that the ActR-I, BMPR-IA, and BMPR-IB receptors and the BMPR-II receptor are expressed and functional for OP-1 in FRC cells and that regulation of synthesis of these receptors may be a mechanism by which a specific cell type responds to OP-1. The turnover rate of these receptor proteins might be relatively long and another type II receptor(s) for OP-1 might be functional in FRC cells.
Contortrostatin, a Homodimeric Snake Venom Disintegrin, Is a Potent Inhibitor of Osteoclast Attachment
Authors: Mercer B. , Markland F. , Minkin C. 
Published: April 2006

Abstract
Disintegrins are small disulfide-rich proteins containing an Arg-Gly-Asp (RGD) sequence near their carboxyl terminus. These polypeptides inhibit binding of adhesion molecules to their receptors (integrins) on the surface of cells. Osteoclasts express integrins, heterodimeric cell surface adhesion receptors, that have been shown to be involved in interactions with the extracellular matrix (ECM), including attachment to bone and bone resorption. It has recently been shown that disintegrins effectively inhibit attachment of osteoclasts to components of the ECM and also disrupt osteoclast-mediated bone resorption. Here we characterize the effects of contortrostatin (CTS), a novel homodimeric snake venom disintegrin, on osteoclast attachment. Plastic dishes coated with CTS were able to support osteoclast attachment with a high affinity (EC50,CTS = 86 ± 6.7 nM) similar to that of vitronectin (VTN; EC50,VTN = 80 ± 20 nM). Further, CTS was observed to inhibit completely osteoclast attachment to fetal bovine serum (FBS; IC50,FBS = 0.36 ± 0.04 nM) and VTN (IC50,VTN = 0.85 ± 0.13 nM). We used monoclonal antibodies directed against the β1 (monoclonal antibody [MAb] CD29) and β3 (MAb F11) integrin subunits to explore the mechanism of osteoclast attachment to immobilized CTS. Only MAb F11 inhibited attachment to immobilized CTS (IC50 = 0.41 ± 0.12 μg/ml), suggesting that binding to CTS is mediated in part by a β3 integrin, presumably the αvβ3 VTN receptor. In further support of an integrin-mediated mechanism, binding of osteoclasts to CTS is inhibited by the RGD peptide, GRGDSP. CTS was also more potent (IC50,FBS = 0.36 ± 0.04 nM) at inhibiting osteoclast attachment to FBS-coated wells than the monomeric snake venom disintegrin echistatin (IC50,FBS = 8.9 ± 1.5 nM) or VTN (IC50,FBS = 97.5 ± 25.5 nM). Taken together, these data suggest that the snake venom disintegrin CTS is a potent inhibitor of β3 integrin-mediated osteoclast attachment, presumably involving the VTN receptor (an αvβ3 integrin). Further studies of the mechanism of CTS–osteoclast interactions may aid in the design of peptide mimetics to act as antiresorptive agents for the treatment of osteoporosis and other skeletal pathology.
Effect of Two Training Regimens on Bone Mineral Density in Healthy Perimenopausal Women: A Randomized Controlled Trial
Authors: Heinonen Ari , Oja Pekka , Sievänen Harri , Pasanen Matti , Vuori Ilkka 
Published: April 2006

Abstract
The aim of this randomized controlled trial was to evaluate the effects of 18 months of calisthenics and endurance training regimens on bone mineral density (BMD) in perimenopausal women. Clinically healthy sedentary female volunteers (n = 105) aged 52–53 years were randomly assigned to a calisthenics (n = 36), endurance (n = 34), or control (n = 35) group. The calisthenics training (2.6 times per week on average, 50 minutes per session) consisted of rhythmic strength-endurance exercises by large muscle groups, and the endurance training (3.2 times per week, 50 minutes) consisted of walking, stair climbing, ergometer cycling, and jogging at a controlled heart rate zone corresponding to 55–75% of the individual maximal oxygen uptake (VO2max) of the subjects. The control subjects performed a light stretching program once a week. The BMD of the lumbar spine (L2-L4), right femoral neck, calcaneus, and distal radius was measured by dual-energy X-ray absorptiometry at 0, 4, 8, 10, 14, and 18 months, and the maximal isometric strength during trunk extension and flexion, leg extension, and arm flexion and the VO2max by ergospirometry were evaluated at 0, 8, 10, and 18 months of intervention. The VO2max improved significantly (p = 0.021) in the endurance group. The linear trend of the femoral neck BMD in the endurance group, as determined by generalized linear models, was significantly different (p = 0.043) from that of the control group, the trend indicating a maintenance of the prestudy BMD. In the calisthenics group, the training effect was not significant. However, the distal radius BMD of the endurance group showed a significant negative trend (p = 0.006). These results suggest that multiexercise endurance training maintains the BMD the clinically important femoral neck of perimenopausal women. This form of endurance training proved also to be feasible for healthy perimenopausal women.
Intermittent and Continuous Administration of the Bisphosphonate Ibandronate in Ovariohysterectomized Beagle Dogs: Effects on Bone Morphometry and Mineral Properties
Authors: Monier-Faugere Marie-Claude , Geng Zhaopo , Paschalis Eleftherios P. , Qi Quanle , Arnala Illka , Bauss Frieder , Boskey Adele L. , Malluche Hartmut H. 
Published: April 2006

Abstract
Bisphosphonates have emerged as a valuable treatment for postmenopausal osteoporosis. Bisphosphonate treatment is usually accompanied by a 3–6% gain in bone mineral density (BMD) during the first year of treatment and by a decrease in bone turnover. Despite low bone turnover, BMD continues to increase slowly beyond the first year of treatment. There is evidence that bisphosphonates not only increase bone volume but also enhance secondary mineralization. The present study was conducted to address this issue and to compare the effects of continuous and intermittent bisphosphonate therapy on static and dynamic parameters of bone structure, formation, and resorption and on mineral properties of bone. Sixty dogs were ovariohysterectomized (OHX) and 10 animals were sham-operated (Sham). Four months after surgery, OHX dogs were divided in six groups (n = 10 each). They received for 1 year ibandronate daily (5 out of 7 days) at a dose of 0, 0.8, 1.2, 4.1, and 14 μg/kg/day or intermittently (65 μg/kg/day, 2 weeks on, 11 weeks off). Sham dogs received vehicle daily. At month 4, there was a significant decrease in bone volume in OHX animals (p &lt; 0.05). Doses of ibandronate ≥ 4.1 μg/kg/day stopped or completely reversed bone loss. Bone turnover (activation frequency) was significantly depressed in OHX dogs given ibandronate at the dose of 14 μg/kg/day. This was accompanied by significantly higher crystal size, a higher mineral-to-matrix ratio, and a more uniformly mineralized bone matrix than in control dogs. This finding lends support to the hypothesis that an increase in secondary mineralization plays a role in gain in BMD associated with bisphosphonate treatment. Moreover, intermittent and continuous therapies had a similar effect on bone volume. However, intermittent therapy was more sparing on bone turnover and bone mineral properties. Intermittent therapy could therefore represent an attractive alternative approach to continuous therapy.
High-Dose Estrogen Induces De Novo Medullary Bone Formation in Female Mice
Authors: Samuels A. , Perry M. J. , Tobias J. H. 
Published: April 2006

Abstract
It is well recognized that, in the mouse, high-dose estrogen induces sclerosis within the shaft of long bones, an action that is largely thought to reflect increased osteoblastic cellular activity. We undertook to characterize this response in more detail, by performing a histologic analysis of the early changes induced by high-dose estrogen in the tibial cavity of young intact female mice. Female mice were sacrificed immediately before or 4, 8, 12, or 24 days after commencing subcutaneous injections of 17β-estradiol (500 μg/animal/week), and longitudinal tibial sections were subsequently examined. Estrogen was found to cause a rapid gain in cancellous bone, with cancellous bone volume increasing by ∼50% after 8 days, and by 5-fold after 24 days. Analysis of cancellous double-labeled surfaces revealed that this gain in bone reflected the emergence of new cancellous bone formation sites within the medullary cavity, rather than the reactivation and extension of formation over pre-existing bone surfaces. Comparison of the time course of these changes between proximal and distal regions of the proximal tibial metaphysis suggested that these new cancellous formation sites appear as a rapid wave extending distally from the secondary spongiosa. Alkaline phosphatase (ALP) immunocytochemistry revealed that, by 12 days after estrogen administration, a population of strongly ALP positive cells had appeared throughout the marrow cavity. We conclude that, at the proximal tibial metaphysis of female mice, estrogen-induced medullary sclerosis largely reflects a process of de novo medullary bone formation, possibly mediated by the generation of osteoblasts from bone marrow osteoprogenitor cells. (J Bone Miner Res 1999; 14: 178–186)
Effect of Prostaglandin and Bisphosphonate on Cancellous Bone Volume and Structure in the Ovariectomized Rat Studied by Quantitative Three-Dimensional Nuclear Magnetic Resonance Microscopy
Authors: Takahashi Masaya , Wehrli Felix W. , Wehrli Suzanne L. , Hwang Scott N. , Lundy Mark W. , Hartke Jim , Borah Babul 
Published: April 2006

Abstract
The purpose of this work was to evaluate the potential of nuclear magnetic resonance microscopy (NMRM) in conjunction with a processing technique to monitor the effect of preventive agents in an ovariectomized (OVX) rat. Twenty-five female Sprague-Dawley rats were OVX at 6 months of age (except for the intact control group), allowed to lose bone for 60 days, and then treated for 60 days. During treatment, animals were administered vehicle, prostaglandin E2 (PGE2; 6 mg/kg), or alendronate (3 μg/kg) subcutaneously once a day. Subsequently, tibiae were harvested and the marrow removed. NMRM was carried out at 9.4 T, with the specimens immersed in 1.2 mM diethylenetriaminepentaacetic acid-gadolinium salt (Gd-DTPA) aqueous solution. A three-dimensional (3D) partial flip-angle pulse sequence was used, providing a 1283 array of (46 μm)3 isotropic voxels. Fifty of the 128 axial images in the 3D data set comprising ∼2.4 mm volume distal to the growth plate were processed from each specimen using a probability-based method for determining bone volume fraction (BVF), tubularity, contiguity, as well as the mean trabecular plate thickness and separation. PGE2 and alendronate altered BVF consistently at all tibial regions. The effect of alendronate was to keep BVF about midway between intact and OVX, whereas PGE2 returned BVF to intact levels. The other parameters showed similar responses to treatment. The strongest discriminator was trabecular BVF, which could obviously differentiate the groups. The study establishes NMRM as a nondestructive histomorphometric method for the quantitative evaluation of drug response in a rat ovariectomy model.