bluuebunny/crossref_metadata_2025_split huggingface dataset:
Intermittent On/Off Prostaglandin E2 and Risedronate Are Equally Anabolic as Daily PGE2 Alone Treatment in Cortical Bone of Ovariectomized Rats
Authors: Ma Yan Fei , Pan Zeng , Jee Webster S. S. , Lin Chao Hua , Liang Hao Hai , Chen Hongka , Pun Sunwah , Li Xiao Jian 
Published: April 2006

Abstract
In this study, we evaluated the rat cortical bone changes after a two-cycle, 60-day each (ON/OFF/ON/OFF) treatment with either prostaglandin E2 (OVX/c-PGE2) alone or in combination with risedronate (OVX/c-PGE2+Ris), in comparison with daily treatment with PGE2 for 240 days (OVX/PGE2−240d) in ovariectomized (OVX) rats. At the end of the study, we found that: (1) the overall effectiveness of the treatment on bone mass in the tibial shaft indicates the following ranking: OVX/PGE2−240d = OVX/c-PGE2+Ris &gt; OVX/c-PGE2 &gt; OVX/c-Ris ≥ OVX = aging; (2) the same bone mass and architecture were produced in the OVX/PGE2−240d and the OVX/c-PGE2+Ris groups, but the histomorphometric profiles differed in that the former exhibited a higher bone turnover and index of resorption; (3) OVX/c-PGE2+Ris treatment prevented endocortical bone loss and minimized trabecular bone loss during the OFF periods; and (4) the OVX/c-PGE2 alone treatment resulted in the accumulation of less total bone than OVX/PGE2−240d and OVX/c-PGE2+Ris because it could not maintain most of the new subendocortical and marrow trabecular bone generated earlier. In summary, both continuous daily PGE2 and two cycles ON/OFF combined PGE2 and Ris treatments result in more bone mass than two cycles ON/OFF PGE2 alone and Ris alone in estrogen-deficient rats. This study showed that the anabolic effects of PGE2 can be induced and maintained either by continuous administration or by cyclical PGE2+Ris.
Age-Related (Type II) Femoral Neck Osteoporosis in Men: Biochemical Evidence for Both Hypovitaminosis D– and Androgen Deficiency–Induced Bone Resorption
Authors: Boonen Steven , Vanderschueren Dirk , Cheng Xiao Guang , Verbeke Geert , Dequeker Jan , Geusens Piet , Broos Paul , Bouillon Roger 
Published: April 2006

Abstract
The problem of osteoporosis in men has recently been recognized as an important public health issue. To test the hypothesis that endocrine deficiency–mediated alterations in bone metabolism might contribute to osteoporotic fracture risk in elderly men, serum levels of 25-hydroxycholecalciferol (25(OH)D), 1,25-dihydroxycholecalciferol (1,25(OH)2D), intact parathyroid hormone (PTH), testosterone, and estradiol were measured in 40 males (mean age 73 years) who were consecutively recruited within 18 h following a fracture of the proximal femur, and in an equal number of community-living older men (mean age 72 years) who served as controls. In addition, circulating osteocalcin and urinary excretion of (deoxy)pyridinoline were determined as markers of bone formation and resorption, respectively. No differences were observed between the mean serum concentrations of osteocalcin and estradiol. Serum levels of 25(OH)D, 1,25(OH)2D, and testosterone, however, were decreased in hip fracture patients. When correcting for differences in vitamin D binding protein, differences in 1,25(OH)2D did not persist, whereas serum 25(OH)D was still significantly lower in patients than in controls (6.1 ± 4.3 vs. 7.6 ± 2.8, p = 0.01). Similarly, a highly significant deficit was observed in the free testosterone index, calculated from total testosterone and the level of sex hormone binding globulin (2.6 ± 1.3 vs. 8.2 ± 2.9, p &lt; 0.001). Serum PTH and urinary pyridinium cross-links, however, were markedly increased in the fracture group. Moreover, in fracture patients, free 25(OH)D and free testosterone were both significant and mutually independent negative predictors of (deoxy)pyridinoline excretion. Although limited by its cross-sectional design, the present study suggests that both hypovitaminosis D and androgen deficiency may predispose to bone resorption in elderly men and in turn to remodeling imbalance and fracture risk.
A New Method of Bone Tissue Measurement Based upon Light Scattering
Authors: Takeuchi Akira , Araki Ryuichiro , Proskurin S. G. , Takahashi Yukari , Yamada Yukio , Ishii Jun , Katayama Shigehiro , Itabashi Akira 
Published: April 2006

Abstract
In recent years, time-resolved spectroscopy systems using near infrared pulsed laser have been applied to develop optical computed tomography. We applied this technique to measure the optical properties of osseous tissue. First, we gradually demineralized 10 mm blocks of bovine trabecular bone with EDTA, maintaining the absorption characteristics and structure but varying the hydroxyapatite content, thus creating specimens differing only in light scattering properties. We used computer densitograms to assess light penetration, and analyzed the correlation with bone mineral density (BMD) as with dual-energy X-ray absorptiometry scans. The light penetration increased with decreasing BMD. Second, using the above-mentioned pulsed laser time-resolved spectroscopy system, we investigated the correlation between the BMD and the time response waveforms of 10-mm blocks of bovine cortical bone, trabecular bone, and surrounding tissue as well as human trabecular bone. The human lumbar vertebral bone also displayed an inverse correlation between BMD and maximum light penetration and a positive correlation between BMD and peak time delay. This is the first demonstration of a correlation between BMD and light scattering properties showing that BMD can indeed be measured with light. Our results show the possibility of obtaining information on internal bone structure and composition in vivo through assessment of the waveforms obtained by a time-resolution system in the near infrared region.
Bone Mineral Density and Blood Flow to the Lower Extremities: The Study of Osteoporotic Fractures
Authors: Vogt Molly T. , Cauley Jane A. , Kuller Lewis H. , Nevitt Michael C. 
Published: April 2006

Abstract
This study tests the hypothesis that reduced blood flow to the lower extremities may affect bone remodeling, resulting in a decrease in bone mineral density (BMD). BMD was measured in the axial and appendicular skeleton of 1292 elderly women (mean age, 71 years) enrolled in the Study of Osteoporotic Fractures. The ratio of the posterior tibial and brachial systolic blood pressures, the ankle/arm index, was used as a measure of blood flow to the legs. In the cross-sectional analysis, this index was positively correlated with BMD at the radius, calcaneus, and hip, but not at the spine. A decrease in the index of 2 standard deviations (SD) (as might occur in patients with moderate arterial disease) was associated with a decrease of 3.7% (95% CI, 1.7%, 5.8%) in hip BMD. The effect size at the hip decreased from 3.7 to 1.8% (and was not statistically significant) when adjustment was made for smoking and/or body mass index (BMI). In the prospective analysis, the rate of bone loss at the hip and calcaneus was greater (p &lt; 0.05) among women whose annual decrease in ankle/arm index was more than 1 SD greater than the mean decrease. This increase was independent of estrogen use, smoking, BMI, pattern of fat distribution, history of diabetes, exercise, and ability to walk. The results from this prospective community-based study provide the first evidence that among relatively healthy older women decreased vascular flow in the lower extremities may be associated with an increased rate of bone loss at the hip and calcaneus.
The Role of Testosterone in Cyclosporine-Induced Osteopenia
Authors: Bowman A. R. , Sass D. A. , Dissanayake I. R. , Ma Y. F. , Liang H. , Yuan Z. , Jee W. S. S. , Epstein S. 
Published: April 2006

Abstract
Our laboratory has demonstrated that the immunosuppressants Cyclosporin A (CsA) and tacrolimus (FK506), in vivo in the rat, produce a high-turnover osteopenia. CsA is known to decrease serum testosterone (Test) levels both in the rat and in human transplant patients. Less is known of FK506's effect on androgens. CsA-induced hypogonadism may contribute to the aforementioned bone loss because hypogonadism itself is a risk factor for osteoporosis and fracture. The aim of this study was to assess serum androgen levels following CsA and FK506 therapy and to see whether Test replacement therapy, in the form of 28-day controlled release subcutaneous pellet implants, could prevent CsA-induced osteopenia. Two experiments were conducted. In experiment I, four groups of 6-month-old male Sprague-Dawley rats received the following: (A) CsA vehicle and placebo pellet, (B) Test 15 mg pellet and CsA vehicle, (C) CsA 10 mg/kg and placebo pellet, (D) Test 15 mg pellet and CsA 10 mg/kg. In experiment II, two groups of rats received (E) FK506 vehicle and (F) FK506 4 mg/kg. CsA, FK506, and vehicles were given for 28 days by daily oral gavage. The rats were weighed and bled on days 0, 14, and 28. All rats received double fluorescent labeling, and on day 28 the tibiae were removed for histomorphometry. Whole blood was assayed for CsA and FK506 levels. Serum was assayed for total and free Test as well as for osteocalcin (BGP), blood urea nitrogen (BUN), creatinine, and calcium. Whole blood monoclonal CsA levels measured by fluorescent immunoassay were in the therapeutic range, while a drug concentration profile showed good absorption of FK506. Those rats receiving Test and FK506 lost weight, while those receiving CsA remained constant. BUN was only marginally elevated in the CsA-treated groups on day 28 (p &lt; 0.05), while creatinine was unchanged. On day 28, total and free Test was significantly reduced in the CsA-treated rats versus control (p &lt; 0.05), while Test replacement therapy maintained total Test levels above vehicle (p &lt; 0.01) and free Test levels similar to vehicle on day 28. FK506 did not lower total or free Test levels. BGP levels were significantly increased in the CsA (p &lt; 0.01) and FK506 (p &lt; 0.001) groups on day 28. BGP in the groups receiving Test alone and in combination with CsA remained similar to vehicle. Histomorphometry confirmed CsA- and FK506-induced high-turnover osteopenia. The Test alone group marginally increased bone formation. Test replacement failed to prevent the CsA-induced bone loss. In conclusion, immunosuppressive doses of CsA, but not FK506, lowers serum total and free Test. Hypoandrogenemia does not seem to be a major factor in CsA-induced osteopenia because bone loss occurs despite Test replacement.
Effect of Resistance Exercise Training on Bone Formation and Resorption in Young Male Subjects Assessed by Biomarkers of Bone Metabolism
Authors: Fujimura Rei , Ashizawa Noriko , Watanabe Manami , Mukai Naoki , Amagai Hitoshi , Fukubayashi Toru , Hayashi Koichiro , Tokuyama Kumpei , Dr. Suzuki Masashige 
Published: April 2006

Abstract
We studied the effects of high intensity resistance exercise training on bone metabolism in 17 young adult Oriental males (23–31 years) by measuring sensitive biomarkers of bone formation and resorption. The subjects were assigned to a training group and a sedentary group. The training group followed a weight training program three times per week for 4 months. In the training group, serum osteocalcin concentration and serum bone-specific alkaline phosphatase activity were significantly increased within the first month after the beginning of resistance exercise training, and the elevated levels remained throughout the training period, while there was no significant change in plasma procollagen type-I C-terminal concentration. Urinary deoxypyridinoline excretion was transiently suppressed and returned to the initial value but was never stimulated during the 4 months. These results suggest that the resistance exercise training enhanced bone formation without prior bone resorption. In the sedentary group, there was no significant difference in bone metabolic markers except plasma procollagen type-I C-terminal, which continuously decreased during the experimental period. There were no significant changes in total and regional bone mineral density in either group. In conclusion, (1) resistance exercise training increased markers of bone formation, while it transiently suppressed a marker of bone resorption, and (2) such adaptive changes of bone metabolism to resistance exercise training occurred during the early period of the training, before changes in bone density were observable through densitometry.
Dexamethasone Stimulates Osteoclast-like Cell Formation by Directly Acting on Hemopoietic Blast Cells and Enhances Osteoclast-like Cell Formation Stimulated by Parathyroid Hormone and Prostaglandin E2
Authors: Kaji Hiroshi , Sugimoto Toshitsugu , Kanatani Masanori , Nishiyama Katsuhito , Chihara Kazuo 
Published: April 2006

Abstract
Although an excess of glucocorticoid induces secondary osteoporosis, the mechanism still remains unclear, particularly in regard to glucocorticoid-stimulated bone resorption. We examined the effects of dexamethasone (Dex) on osteoclast-like cell formation and bone-resorbing activity by employing mouse bone and spleen cell cultures and further investigated whether Dex would modulate osteoclast-like cell formation stimulated by several bone-resorbing factors. Dex stimulated osteoclast-like cell formation in stromal cell-containing mouse bone cell cultures in a concentration-dependent manner. Also, Dex significantly stimulated osteoclast-like cell formation from hemopoietic blast cells in spleen cell cultures derived from 5-fluorouracil-pretreated mice. In contrast, Dex (10−8 M) did not affect the bone-resorbing activity of mature osteoclasts. Pretreatment with 10−8 M Dex significantly enhanced osteoclast-like cell formation in unfractionated mouse bone cell cultures stimulated by 10−8 M human (h) parathyroid hormone (PTH) (1–34), 10−8 M hPTH-related protein (1–34) and 10−6 M prostaglandin E2, but not by 10−8 M 1,25-dihydroxyvitamin D3 (1,25(OH)2D3). Moreover, pretreatment with 10−8 M Dex significantly enhanced osteoclast-like cell formation stimulated by both forskolin and dbcAMP. In contrast, pretreatment with 10−8 M Dex significantly inhibited osteoclast-like cell formation in mouse spleen cell cultures stimulated by both 10−8 M hPTH(1–34) and 10−8 M 1,25(OH)2D3. These findings suggest that Dex stimulates osteoclast-like cell formation, at least in part by directly acting on hemopoietic blast cells. They further suggest that Dex enhances osteoclast-like cell formation stimulated by PTH and prostaglandin E2 through an indirect pathway via cells other than hemopoietic blast cells.
Microgravity Reduces the Differentiation of Human Osteoblastic MG-63 Cells
Authors: Carmeliet Geert , Nys Guy , Bouillon Roger 
Published: April 2006

Abstract
Spaceflight leads to osteopenia in both humans and animals, principally as a result of decreased bone formation, which might be the consequence of impaired osteoblast differentiation. The effect of microgravity on osteoblast differentiation in vitro was investigated using the human osteosarcoma cell line MG-63. Genes related to matrix formation and maturation were quantified both at the protein and mRNA level in untreated and hormone-treated (dihydroxyvitamin D3 [1,25(OH)2D3], 10−7 M; transforming growth factor β2 (TGF-β2), 10 ng/ml) cells cultured for 9 days under microgravity conditions aboard the Foton 10 satellite and compared with ground and inflight unit-gravity cultures. The expression of alkaline phosphatase (ALP) activity following treatment at microgravity increased only by a factor of 1.8 compared with the 3.8-fold increase at unit-gravity (p &lt; 0.01), whereas no alteration was detected in the production of collagen type I between unit- and microgravity. In addition, gene expression for collagen Iα1, ALP, and osteocalcin following treatment at microgravity was reduced to 51, 62, and 19%, respectively, of unit-gravity levels (p &lt; 0.02). The lack of correlation between collagen type I gene and protein expression induced by microgravity is most likely related to the different kinetics of gene and protein expression observed at unit-gravity: following treatment with 1,25(OH)2D3 and TGF-β2, collagen Iα1 mRNA increased gradually during 72 h, but collagen type I production was already maximal after treatment for 48 h. In conclusion, microgravity decreases the activity of osteoblasts in vitro; in particular the differentiation of osteoblasts in response to systemic hormones and growth factors is reduced by microgravity.
Hip Fracture and Osteoporosis in a XIIth Dynasty Female Skeleton from Lisht, Upper Egypt
Authors: Dequeker Jan , Ortner Donald J. , Stix Agnes I. , Cheng Xiao-Gguang , Brys Peter , Boonen Steven 
Published: April 2006

Abstract
Osteoporosis and complications arising from loss of bone mass have been present in human populations for thousands of years. However, reports of this disease in antiquity remain uncommon. The purpose of this report is to describe an important case of osteoporosis in ancient Egypt because of its intrinsic interest and to provide perspectives on factors contributing to this condition today. The case providing the focus for this report is from Lisht, Upper Egypt and is dated to the XIIth Dynasty (1990–1786 B.C.). Methods used to characterize the pathology include gross anatomical study, radiology, and radiographic measurements. Observations, measurements, and indices all indicate osteoporosis complicated by fracture of the femoral neck and compression fractures of some vertebrae. The Lisht case adds to a small corpus of reports on osteoporosis and complicating factors of this disease in antiquity. Long-term survival of an extracapsular fracture of the femoral neck in this case is remarkable and may reflect supportive social conditions.
Peyronie's Disease Is Associated with Paget's Disease of Bone
Authors: Lyles Kenneth W. , Gold Deborah T. , Newton Rebecca A. , Parekh Sohail , Shipp Kathy M. , Pieper Carl F. , Krishan Ramesh , Carson Culley C. 
Published: April 2006

Abstract
Peyronie's disease is an idiopathic disorder in which an inflammatory fibrosis occurs in the tunica albuginea of the corpora cavernosa which causes the erect penis to become deformed. Peyronie's disease has a prevalence of 1% in men over age 50 years. Paget's disease of bone is a chronic skeletal disease with areas of increased bone turnover leading to pain, deformity, and in some cases arthritis. Because of a high rate of Peyronie's disease in subjects in a Paget's disease industry-sponsored drug trial, we asked whether there was an association between Peyronie's disease and Paget's disease of bone. We evaluated 61 men with Paget's disease attending our clinic for metabolic bone disease in a tertiary referral hospital, reviewed hospital records of all men discharged from our three hospitals with the diagnosis of Peyronie's disease, and mailed a validated questionnaire about shape of the erect penis to 1500 male members of the Paget Foundation. In the clinic population of men with Paget's disease of bone, 51 of 61 (83.6%) reported having normal erections; 10 patients (16.4%) were impotent. Sixteen of the 51 men (31.4%) had developed a bend or deformity in their erect penis which was confirmed by a urologist's examination to be Peyronie's disease. When the men with Paget's disease with and without Peyronie's disease were compared, there was no difference in their ages, years with Paget's disease, or serum alkaline phosphatase level. Upon medical record review, 1 patient of 262 (0.4%) with Peyronie's disease was found to have Paget's disease of bone. The men with Paget's disease returned their questionnaires for a response rate of 44.8% and reported Peyronie's disease with a prevalence of 14.5%. We suggest that Peyronie's disease is associated with Paget's disease of bone. Furthermore, we suggest that Peyronie's disease may be a previously unrecognized complication of Paget's disease of bone.
Histomorphometric Assessment of Bone Mass, Structure, and Remodeling: A Comparison Between Healthy Black and White Premenopausal Women
Authors: Parisien May , Cosman Felicia , Morgan Dorcas , Schnitzer Michele , Liang Xiaoguang , Nieves Jeri , Forese Laura , Luckey Marjorie , Meier Diane , Shen Victor , Lindsay Robert , Dempster David W. 
Published: April 2006

Abstract
While noninvasive studies of bone mass and turnover in blacks and whites abound, histologic evaluations are very rare. We have performed a comparative bone histomorphometric study of iliac biopsies from 55 healthy, premenopausal women including 21 blacks (mean age 33.4 + 1.2 years) and 34 whites (mean age 32.5 + 0.8 years) of comparable age, weight, body composition, education, and lifestyle. Biochemical indices of mineral metabolism: parathyroid hormone, 25-hydroxyvitamin D, 1,25-dihydroxyvitamin D, serum ionized calcium, serum phosphorus, and urinary calcium/creatinine were measured in the fasting state. Blacks had lower 25-hydroxyvitamin D (31.5 ± 3.36 vs. 63.21 ± 3.79 nmol/l, p = 0.0001). Histomorphometric indices of bone volume, structure, and connectivity were not different between groups. The following indices of bone remodeling were also similar in both groups: eroded perimeter, osteoid width, mineralizing perimeter, tissue-based bone formation rate, osteoid maturation time, active formation period, and activation frequency. However, osteoid perimeter (black [B] = 15.85 ± 1.30 vs. white [W] = 9.49 ± 0.70%, p = 0.0002), osteoid area (B = 2.55 ± 0.32 vs. W = 1.39 ± 0.12%, p = 0.003), single-labeled perimeter (B = 5.46 ± 0.54 vs. W = 4.04 ± 0.33%, p = 0.03), mineralization lag time (B = 38.18 ± 4.04 vs. W = 21.83 ± 1.60 days, p &lt; 0.009), and total formation period (B = 148.15 ± 19.70 vs. W = 84.04 ± 7.62 days, p = 0.0056) were higher in blacks than in whites. The quiescent perimeter (B = 76.91 ± 1.40 vs. W = 84.25 ± 0.91%, p = 0.0001), mineral apposition rate (B = 0.70 ± 0.02 vs. W = 0.75 ± 0.02 μm/day, p = 0.066), mineralizing osteoid perimeter (B = 0.49 ± 0.04 vs. W = 0.75 ± 0.04%, p = 0.0001) and adjusted apposition rate (B = 0.35 ± 0.04 vs. W = 0.58 ± 0.04 μm3/μm2/day, p = 0.0001) were all lower in blacks than in whites. These results indicate that there are no differences in bone volume, microstructure, or turnover between black and white premenopausal women. However, there are significant differences in the mechanism of bone formation between the two groups, with a lower rate of mineralized matrix apposition within each remodeling unit and a longer total formation period in blacks than in whites. The differences appear to be the result of more frequent and/or longer inactive periods in the life span of the bone formation units in blacks. These differences may allow a greater overall deposition of bone mineral in black women and therefore help explain a higher bone mass and perhaps better bone quality in black than white women.