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Sample records for bone mass loss

  1. Biologically rational ways of bone mass loss prophylaxis and treatment

    Directory of Open Access Journals (Sweden)

    A. S. Avrunin

    2015-01-01

    Full Text Available Aim. Based on own and literature date to define biologically rational elements of complex approach to bone mass loss prophylaxis and treatment. Nowadays there are two points of view regarding bone mass loss prophylaxis and treatment. The first favor pharmaceuticals as a basic and physical exercises as additional. According to the second, therapeutic and prophylactic significance of physical exercises in maintenance and development of structural and functional capacities of musculoskeletal system is fundamental. The latter approach correspond to evolutionary formed biological model in that muscles act upon levers - bones that connected by means of joints and provide the movement of the body against gravity. The present work from pathogenethically point of view establish the systemic approach to the bone mass loss prophylaxis and treatment. It is based on physical exercises while additional pharmacotherapy that should aim for optimization of regulatory function of bone cells, first of all osteocytes providing for adaptational reorganisation of bone structures.

  2. Low body mass index is an important risk factor for low bone mass and increased bone loss in early postmenopausal women. Early Postmenopausal Intervention Cohort (EPIC) study group

    DEFF Research Database (Denmark)

    Ravn, Pernille; Cizza, G; Bjarnason, N H

    1999-01-01

    Thinness (low percentage of body fat, low body mass index [BMI], or low body weight) was evaluated as a risk factor for low bone mineral density (BMD) or increased bone loss in a randomized trial of alendronate for prevention of osteoporosis in recently postmenopausal women with normal bone mass (n...... (r = -0.12 to -0.15, p mass parameters and response to alendronate treatment, which...... indicated that risk of low bone mass and increased bone loss caused by thinness could be compensated by alendronate treatment. In conclusion, thinness is an important risk factor for low bone mass and increased bone loss in postmenopausal women. Because the response to alendronate treatment is independent...

  3. Effects of COLIA1 polymorphisms and haplotypes on perimenopausal bone mass, postmenopausal bone loss and fracture risk

    DEFF Research Database (Denmark)

    González-Bofill, N; Husted, Camilla L.; Harsløf, Torben

    2011-01-01

    mineral density (BMD) and increased bone turnover at menopause and after 10 years of follow-up. Introduction We wanted to investigate whether the -1997G/T, -1663indelT and +1245G/T polymorphisms in the COLIA1 gene are associated with perimenopausal bone mass, early postmenopausal bone loss and interact.......015±0.006 g/cm2 and 0.017±0.006 g/cm2, respectively (pchanges in bone mass and fracture risk and no overall interaction with the effects of hormone therapy could be demonstrated for any of the polymorphisms in COLIA1. Conclusions The -1997G/T polymorphism...... and haplotype 3 are significantly associated with perimenopausal bone mass, and these effects were sustained up to 10 years after menopause. No association between the -1663indelT or +1245G/T polymorphisms and peri- or postmenopausal bone mass could be demonstrated....

  4. Chronic Alcohol Abuse Leads to Low Bone Mass with No General Loss of Bone Structure or Bone Mechanical Strength

    DEFF Research Database (Denmark)

    Ulhøi, Maiken Parm; Meldgaard, Karoline; Steiniche, Torben

    2017-01-01

    Chronic alcohol abuse (CAA) has deleterious effects on skeletal health. This study examined the impact of CAA on bone with regard to bone density, structure, and strength. Bone specimens from 42 individuals with CAA and 42 individuals without alcohol abuse were obtained at autopsy. Dual-energy X...... wall thickness of trabecular osteons compared to individuals without alcohol abuse. No significant difference was found for bone strength and structure. Conclusion: CAA leads to low bone mass due to a decrease in bone formation but with no destruction of bone architecture nor a decrease in bone...

  5. Chronic Alcohol Abuse Leads to Low Bone Mass with No General Loss of Bone Structure or Bone Mechanical Strength.

    Science.gov (United States)

    Ulhøi, Maiken Parm; Meldgaard, Karoline; Steiniche, Torben; Odgaard, Anders; Vesterby, Annie

    2017-01-01

    Chronic alcohol abuse (CAA) has deleterious effects on skeletal health. This study examined the impact of CAA on bone with regard to bone density, structure, and strength. Bone specimens from 42 individuals with CAA and 42 individuals without alcohol abuse were obtained at autopsy. Dual-energy X-ray absorptiometry (DEXA), compression testing, ashing, and bone histomorphometry were performed. Individuals with CAA had significantly lower bone mineral density (BMD) in the femoral neck and significantly lower bone volume demonstrated by thinner trabeculae, decreased extent of osteoid surfaces, and lower mean wall thickness of trabecular osteons compared to individuals without alcohol abuse. No significant difference was found for bone strength and structure. CAA leads to low bone mass due to a decrease in bone formation but with no destruction of bone architecture nor a decrease in bone strength. It is questionable whether this per se increases fracture risk. © 2016 American Academy of Forensic Sciences.

  6. Establishment of age- and sex-adjusted reference data for hand bone mass and investigation of hand bone loss in patients with rheumatoid arthritis treated in clinical practice

    DEFF Research Database (Denmark)

    Ørnbjerg, Lykke Midtbøll; Østergaard, Mikkel; Jensen, Trine

    2016-01-01

    BACKGROUND: Rheumatoid arthritis is characterised by progressive joint destruction and loss of periarticular bone mass. Hand bone loss (HBL) has therefore been proposed as an outcome measure for treatment efficacy. A definition of increased HBL adjusted for age- and sex-related bone loss is lacking...

  7. Growth hormone mitigates loss of periosteal bone formation and muscle mass in disuse osteopenic rats.

    Science.gov (United States)

    Grubbe, M-C; Thomsen, J S; Nyengaard, J R; Duruox, M; Brüel, A

    2014-12-01

    Growth hormone (GH) is a potent anabolic agent capable of increasing both bone and muscle mass. The aim was to investigate whether GH could counteract disuse-induced loss of bone and muscle mass in a rat model. Paralysis was induced by injecting 4 IU Botox (BTX) into the muscles of the right hind limb. Sixty female Wistar rats, 14 weeks old, were divided into the following groups: baseline, controls, BTX, BTX+GH, and GH. GH was given at a dosage of 5 mg/kg/d for 4 weeks. Compared with controls, BTX resulted in lower periosteal bone formation rate (BFR/BS,-79%, Pbone mineral density (aBMD, -13%, Pbone volume (BV/TV, -26%, Pbone strength (-12%, Pbone strength was found. In addition, GH partly prevented loss of muscle mass (+29% vs. BTX, P<0.001), and tended to prevent loss of muscle CSA (+11%, P=0.064). In conclusion, GH mitigates disuse-induced loss of periosteal BFR/BS at the mid-femur and rectus femoris muscle mass.

  8. Growth hormone mitigates loss of periosteal bone formation and muscle mass in disuse osteopenic rats

    DEFF Research Database (Denmark)

    Grubbe, M-C; Thomsen, Jesper Skovhus; Nyengaard, J R

    2014-01-01

    Growth hormone (GH) is a potent anabolic agent capable of increasing both bone and muscle mass. The aim was to investigate whether GH could counteract disuse-induced loss of bone and muscle mass in a rat model. Paralysis was induced by injecting 4 IU Botox (BTX) into the muscles of the right hind...... limb. Sixty female Wistar rats, 14 weeks old, were divided into the following groups: baseline, controls, BTX, BTX+GH, and GH. GH was given at a dosage of 5 mg/kg/d for 4 weeks. Compared with controls, BTX resulted in lower periosteal bone formation rate (BFR/BS,-79%, Pbone mineral density (a......BMD, -13%, Pbone volume (BV/TV, -26%, Pbone strength (-12%, P

  9. Medicines and Bone Loss

    Science.gov (United States)

    Fact Sheet Medici a ne n s d Bone Loss Some types of medicines can cause bone loss, making your bones weak, if used for a long time. Use over a short time ... old bone and replaces it with new bone. Bone loss occurs when old bone breaks down faster than ...

  10. Effects of Weight Loss on Lean Mass, Strength, Bone, and Aerobic Capacity.

    Science.gov (United States)

    Weiss, Edward P; Jordan, Richard C; Frese, Ethel M; Albert, Stewart G; Villareal, Dennis T

    2017-01-01

    This study aimed to evaluate the hypothesis that exercise attenuates the reductions in lean mass, muscle strength, bone mineral density, and V˙O2max that accompany modest weight loss induced by calorie restriction (CR). Overweight, sedentary women and men (n = 52, 45-65 yr) were randomized to 6%-8% weight loss by using CR, endurance exercise training (EX), or both (CREX). The CR and the CREX groups underwent counseling to reduce energy intake by 20% and 10%, respectively. The EX and the CREX groups exercised 7.4 ± 0.5 and 4.4 ± 0.5 h·wk, respectively. Before and after 16.8 ± 1.1 wk of weight loss, lean mass and bone mineral density were measured with dual-energy x-ray absorptiometry, strength was measured with dynamometry, and aerobic capacity (V˙O2max) was measured with indirect calorimetry during maximal-intensity treadmill exercise. Weight loss was ~7% in all groups. Decreases in whole-body (~2%, P = 0.003) and lower extremity (~4%, P weight loss, these reductions were attenuated in the CREX group (~1%, P = 0.44 and ~2%, P = 0.05, respectively) and absent in the EX group. Absolute aerobic capacity decreased ~6% in the CR group (P = 0.04), was unchanged in the CREX group (P = 0.28), and increased ~15% in the EX group (P weight loss (~7%) induced by 20% CR in overweight women and men decreases lean mass and reduces absolute V˙O2max. Exercise protects against these effects. Although the CR-induced changes might be considered physiologically appropriate for a reduced body weight, exercise preserves and/or improves these parameters during weight loss, which likely improves physical function. These findings support the notion of using exercise as an important component of weight loss programs.

  11. Effects of Weight Loss on Lean Mass, Strength, Bone, and Aerobic Capacity

    Science.gov (United States)

    Weiss, Edward P.; Jordan, Richard C.; Frese, Ethel M.; Albert, Stewart G.; Villareal, Dennis T.

    2016-01-01

    Purpose To evaluate the hypothesis that exercise attenuates the reductions in lean mass, muscle strength, BMD, and VO2max that accompany modest weight loss induced by calorie restriction. Methods Overweight, sedentary women and men (n=52, 45–65y) were randomized to 6–8% weight loss by using calorie restriction (CR), endurance exercise (EX), or both (CREX). The CR and CREX groups underwent counseling to reduce energy intake by 20% and 10%, respectively. The EX and CREX groups exercised 7.4±0.5 and 4.4±0.5 hr/wk, respectively. Before and after 16.8±1.1 weeks of weight loss, lean mass and BMD were measured with dual-energy X-ray absorptiometry, strength was measured with dynamometry, and aerobic capacity (VO2max) was measured with indirect calorimetry during maximal-intensity treadmill exercise. Results Weight loss was ~7% in all groups. Decreases in whole body (~2%, p=0.003) and lower extremity (~4%, p<0.0001) lean mass occurred in the CR group (both p<0.05). Despite similar weight loss, these reductions were attenuated in the CREX group (~1%, p=0.44 and ~2%, p=0.05, respectively) and absent in the EX group. Absolute aerobic capacity decreased ~6% in the CR group (p=0.04), was unchanged in the CREX group (p=0.28) and increased ~15% in the EX group (p<0.0001). No changes in muscle strength or bone were observed. Conclusions Modest weight loss (~7%) induced by 20% calorie restriction in overweight women and men decreases lean mass and reduces absolute VO2max. Exercise protects against these effects. While the CR-induced changes might be considered physiologically appropriate for a reduced body weight, exercise preserves and/or improves these parameters during weight loss, which likely improves physical function. These findings support the notion of using exercise as an important component of weight loss programs. PMID:27580151

  12. The role of fat and lean mass in bone loss in older men: findings from the CHAMP study.

    Science.gov (United States)

    Bleicher, Kerrin; Cumming, Robert G; Naganathan, Vasikaran; Travison, Thomas G; Sambrook, Philip N; Blyth, Fiona M; Handelsman, David J; Le Couteur, David G; Waite, Louise M; Creasey, Helen M; Seibel, Markus J

    2011-12-01

    Weight loss is associated with bone loss; however, it is unclear whether loss of fat or loss of lean body mass plays the key role in this relationship. The aim of this longitudinal analysis was to clarify the relationship between hip BMD, hip BMC and whole body BMC with changes in fat and lean tissue mass in older men. The Concord Health and Aging in Men Project (CHAMP) is a population-based study in Sydney, Australia, involving 1705 men aged 70-97 years. Bone mineral density (BMD) of the total hip, and bone mineral content (BMC) of the hip and whole body (WB), lean mass and fat mass were measured with Dual X-ray Absorptiometry (DXA). Multivariate linear regression models were used to assess relationships. Over 2.2 years of follow-up, 368(33%) men lost at least 2% of their body weight, which included a mean loss of 0.8 kg/year of lean body mass and 0.9 kg/year of fat body mass. Fat loss was strongly associated with BMD loss in men who lost weight. As a group, weight losers lost 1.0% of hip BMD annually compared to 0.2% in men who gained weight, with each kilo of fat loss associated with 0.6%/year hip BMD loss (p<0.0001). Lean mass was not associated with hip BMD loss in weight losers, however, lean mass change was associated with BMD change in men who gained weight (0.3% hip BMD increase per kilo increase of lean mass p<0.01). Maintaining body weight is important for bone health in elderly men. Body fat plays an important role in this relationship, which may reflect the additional metabolic function of adipose tissue. Copyright © 2011 Elsevier Inc. All rights reserved.

  13. Lycopene treatment against loss of bone mass, microarchitecture and strength in relation to regulatory mechanisms in a postmenopausal osteoporosis model.

    Science.gov (United States)

    Ardawi, Mohammed-Salleh M; Badawoud, Mohammed H; Hassan, Sherif M; Rouzi, Abdulrahim A; Ardawi, Jumanah M S; AlNosani, Nouf M; Qari, Mohammed H; Mousa, Shaker A

    2016-02-01

    Lycopene supplementation decreases oxidative stress and exhibits beneficial effects on bone health, but the mechanisms through which it alters bone metabolism in vivo remain unclear. The present study aims to evaluate the effects of lycopene treatment on postmenopausal osteoporosis. Six-month-old female Wistar rats (n=264) were sham-operated (SHAM) or ovariectomized (OVX). The SHAM group received oral vehicle only and the OVX rats were randomized into five groups receiving oral daily lycopene treatment (mg/kg body weight per day): 0 OVX (control), 15 OVX, 30 OVX, and 45 OVX, and one group receiving alendronate (ALN) (2μg/kg body weight per day), for 12weeks. Bone densitometry measurements, bone turnover markers, biomechanical testing, and histomorphometric analysis were conducted. Micro computed tomography was also used to evaluate changes in microarchitecture. Lycopene treatment suppressed the OVX-induced increase in bone turnover, as indicated by changes in biomarkers of bone metabolism: serum osteocalcin (s-OC), serum N-terminal propeptide of type 1 collagen (s-PINP), serum crosslinked carboxyterminal telopeptides (s-CTX-1), and urinary deoxypyridinoline (u-DPD). Significant improvement in OVX-induced loss of bone mass, bone strength, and microarchitectural deterioration was observed in lycopene-treated OVX animals. These effects were observed mainly at sites rich in trabecular bone, with less effect in cortical bone. Lycopene treatment down-regulated osteoclast differentiation concurrent with up-regulating osteoblast together with glutathione peroxidase (GPx) catalase (CAT) and superoxide dismutase (SOD) activities. These findings demonstrate that lycopene treatment in OVX rats primarily suppressed bone turnover to restore bone strength and microarchitecture. Copyright © 2015. Published by Elsevier Inc.

  14. Establishment of age- and sex-adjusted reference data for hand bone mass and investigation of hand bone loss in patients with rheumatoid arthritis treated in clinical practice

    DEFF Research Database (Denmark)

    Ørnbjerg, Lykke Midtbøll; Østergaard, Mikkel; Jensen, Trine

    2016-01-01

    BACKGROUND: Rheumatoid arthritis is characterised by progressive joint destruction and loss of periarticular bone mass. Hand bone loss (HBL) has therefore been proposed as an outcome measure for treatment efficacy. A definition of increased HBL adjusted for age- and sex-related bone loss is lacking......: DXR-BMD was measured from hand x-rays in a reference cohort (1485 men/2541 women) without arthritis randomly selected from an urban Danish population. Sex- and age-related HBL/year was estimated. DXR-BMD was measured in rheumatoid arthritis patients (n = 350: at start of TNFI, and ~2 years after TNFI...... start), of which 135 patients had three x-rays (~2 years prior to TNFI, at start of TNFI, and ~2 years after TNFI start). Individual HBL/year prior to and during TNFI was calculated and compared to reference values. RESULTS: Estimated HBL/year varied strongly with age and sex. Compared to the reference...

  15. Loss of lean body mass affects low bone mineral density in patients with rheumatoid arthritis - results from the TOMORROW study.

    Science.gov (United States)

    Okano, Tadashi; Inui, Kentaro; Tada, Masahiro; Sugioka, Yuko; Mamoto, Kenji; Wakitani, Shigeyuki; Koike, Tatsuya; Nakamura, Hiroaki

    2017-11-01

    Osteoporosis is one of the complications for patients with rheumatoid arthritis (RA). Rheumatoid cachexia, the loss of lean body mass, is another. However, the relationship between decreased lean body mass and reduced bone mineral density (BMD) in patients with RA has not been well studied. This study included 413 participants, comprising 208 patients with RA and 205 age- and sex-matched healthy volunteers. Clinical data, BMD, bone metabolic markers (BMM) and body composition, such as lean body mass and percent fat, were collected. Risk factors for osteoporosis in patients with RA including the relationship BMD and body composition were analyzed. Patients with RA showed low BMD and high BMM compared with controls. Moreover, lean body mass was lower and percent fat was higher in patients with RA. Lean body mass correlated positively and percent fat negatively with BMD. Lean body mass was a positive and disease duration was a negative independent factor for BMD in multivariate statistical analysis. BMD and lean body mass were significantly lower in patients with RA compared to healthy controls. Lean body mass correlated positively with BMD and decreased lean body mass and disease duration affected low BMD in patients with RA. [UMIN Clinical Trials Registry, http://www.umin.ac.jp/ctr/ , UMIN000003876].

  16. Biologicals and bone loss

    NARCIS (Netherlands)

    Krieckaert, C.L.M.; Lems, W.F.

    2012-01-01

    Inflammatory joint diseases are associated with extra-articular side effects including bone involvement.There is an increased risk of osteoporotic fractures. The pathogeneses of local and generalized bone loss share a common pathway. Early and active rheumatoid arthritis is associated with

  17. Menopause and Bone Loss

    Science.gov (United States)

    ... calcium supplement if necessary. • Vitamin D. Your body needs vitamin D to absorb calcium and move it into ... bone density test? • Should I take calcium and vitamin D supplements? How much do I need? • Do I need medication for my bone loss? • ...

  18. Intrauterine stress induces bone loss in adult offspring of C3H/HeJ mice having high bone mass phenotype but not C57BL/6J mice with low bone mass phenotype.

    Science.gov (United States)

    Raygorodskaya, M; Gabet, Y; Shochat, C; Kobyliansky, E; Torchinsky, A; Karasik, D

    2016-06-01

    In this study we examined to what extent and how genetics may modify osteoporosis risk arising due to environmental stresses which act during the antenatal period of life and have the potential to induce bone loss in adulthood. C57Bl/6J (C57) and C3H/HeJ (C3H) mice were used as a model system. The mice were exposed to a single injection of 5-aza-2'-deoxycytidine (5-AZA) on day 10 of pregnancy and the structure and bone mineral density (BMD) of the femur and 3rd lumbar vertebra of 3- and 6-month-old male and female offspring were evaluated by micro-computed tomography (μCT). Besides, we also attempted to evaluate whether 5-AZA affects the expression of some osteogenic genes in the embryonic limb buds. The main observation of this study is that 5-AZA-induced loss of bone quality was registered in 6-mo-old C3H offspring but not in their C57 counterparts. We also observed that C57 and C3H embryos may differ in their response to 5-AZA-induced detrimental stimuli: whereas 5-AZA treated C3H embryos exhibited a decreased expression of Col1a1, C57 embryos exhibit a decreased expression of Sox9. Overall, our study, by thorough characterization of bone homeostasis in 3- and 6-month-old offspring of 5-AZA-exposed C57 and C3H mice, allows hypothesizing that the adaptive response to antenatal insults may be stronger in offspring inherently exhibiting a low bone mass phenotype than in offspring inherently exhibiting a high bone mass phenotype. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. Associated among endocrine, inflammatory, and bone markers, body composition and weight loss induced bone loss

    Science.gov (United States)

    Weight loss reduces co-¬morbidities of obesity but decreases bone mass. Our aims were to determine whether adequate dairy intake could prevent weight loss related bone loss and to evaluate the contribution of energy-related hormones and inflammatory markers to bone metabolism. Overweight and obese w...

  20. A well-balanced diet combined or not with exercise induces fat mass loss without any decrease of bone mass despite bone micro-architecture alterations in obese rat.

    Science.gov (United States)

    Gerbaix, Maude; Metz, Lore; Mac-Way, Fabrice; Lavet, Cédric; Guillet, Christelle; Walrand, Stéphane; Masgrau, Aurélie; Vico, Laurence; Courteix, Daniel

    2013-04-01

    The association of a well-balanced diet with exercise is a key strategy to treat obesity. However, weight loss is linked to an accelerated bone loss. Furthermore, exercise is known to induce beneficial effects on bone. We investigated the impact of a well-balanced isoenergetic reducing diet (WBR) and exercise on bone tissue in obese rats. Sixty male rats had previously been fed with a high fat/high sucrose diet (HF/HS) for 4months to induce obesity. Then, 4 regimens were initiated for 2months: HF/HS diet plus exercise (treadmill: 50min/day, 5days/week), WBR diet plus exercise, HF/HS diet plus inactivity and WBR diet plus inactivity. Body composition and total BMD were assessed using DXA and visceral fat mass was weighed. Tibia densitometry was assessed by Piximus. Bone histomorphometry was performed on the proximal metaphysis of tibia and on L2 vertebrae (L2). Trabecular micro-architectural parameters were measured on tibia and L2 by 3D microtomography. Plasma concentration of osteocalcin and CTX were measured. Both WBR diet and exercise had decreased global weight, global fat and visceral fat mass (pdiet alone failed to alter total and tibia bone mass and BMD. However, Tb.Th, bone volume density and degree of anisotropy of tibia were decreased by the WBR diet (pdiet had involved a significant lower MS/BS and BFR/BS in L2 (pdiet inducing weight and fat mass losses did not affected bone mass and BMD of obese rats despite alterations of their bone micro-architecture. The moderate intensity exercise performed had improved the tibia BMD of obese rats without any trabecular and cortical adaptation. Copyright © 2013 Elsevier Inc. All rights reserved.

  1. DLK1 is a novel regulator of bone mass that mediates estrogen deficiency-induced bone loss in mice

    DEFF Research Database (Denmark)

    Abdallah, Basem M; Ditzel, Nicholas; Mahmood, Amer

    2011-01-01

    Delta-like 1/fetal antigen 1 (DLK1/FA-1) is a transmembrane protein belonging to the Notch/Delta family that acts as a membrane-associated or a soluble protein to regulate regeneration of a number of adult tissues. Here we examined the role of DLK1/FA-1 in bone biology using osteoblast-specific Dlk......1-overexpressing mice (Col1-Dlk1). Col1-Dlk1 mice displayed growth retardation and significantly reduced total body weight and bone mineral density (BMD). Micro-computed tomographis (µCT) scanning revealed a reduced trabecular and cortical bone volume fraction. Tissue-level histomorphometric...... analysis demonstrated decreased bone-formation rate and enhanced bone resorption in Col1-Dlk1 mice compared with wild-type mice. At a cellular level, Dlk1 markedly reduced the total number of bone marrow (BM)-derived colony-forming units fibroblasts (CFU-Fs), as well as their osteogenic capacity...

  2. Breast Cancer and Bone Loss

    Science.gov (United States)

    ... Menopause Map Featured Resource Find an Endocrinologist Search Breast Cancer and Bone Loss July 2010 Download PDFs English ... G. Komen Foundation What is the link between breast cancer and bone loss? Certain treatments for breast cancer ...

  3. Menopausal bone loss and estrogen replacement.

    Science.gov (United States)

    Meema, S; Meema, H E

    1976-07-01

    Throughout adult life the bone mineral mass of the radius is greater in males than in females. In males, it decreases after 60 years of age, while in females, it decreases earlier, at approximately 50 years, and the loss is greater. At the average age of 67 years, one half of the normal white female population has less than the normal amount of bone in the radius. Premenopausal women over the age of 50 do not show any decline of bone mineral mass, while in postmenopausal women, regardless of age, there is a loss of bone mass related to the number of years after menopause. Castrated women have significantly less bone mass than premenopausal women of the same average age. No decrease in cortical thickness of the radius was found in oophorectomized women treated with estrogens after castration. In a long-term, follow-up study, untreated postmenopausal women (after a natural or an artifical menopause) showed a significant loss of bone mass, while estrogen-treated, postmenopausal women showed no such loss. Estrogen treatment thus appears to prevent postmenopausal bone loss.

  4. Physical activity increases bone mass during growth

    OpenAIRE

    Karlsson, Magnus K.; Nordvist, Anders; Karlsson, Caroline

    2008-01-01

    Background: The incidence of fragility fractures has increased during the last half of the 1900?s. One important determinant of fractures is the bone mineral content (BMC) or bone mineral density (BMD), the amount of mineralised bone. If we could increase peak bone mass (the highest value of BMC reached during life) and/or decrease the age-related bone loss, we could possibly improve the skeletal resistance to fracture. Objective: This review evaluates the importance of exercise as a strategy...

  5. Inactivation of Vhl in Osteochondral Progenitor Cells Causes High Bone Mass Phenotype and Protects Against Age-Related Bone Loss in Adult Mice

    Science.gov (United States)

    Weng, Tujun; Xie, Yangli; Huang, Junlan; Luo, Fengtao; Yi, Lingxian; He, Qifen; Chen, Di; Chen, Lin

    2014-01-01

    Previous studies have shown that disruption of von Hippel–Lindau gene (Vhl) coincides with activation of hypoxia-inducible factor α (HIFα) signaling in bone cells and plays an important role in bone development, homeostasis, and regeneration. It is known that activation of HIF1α signaling in mature osteoblasts is central to the coupling between angiogenesis and bone formation. However, the precise mechanisms responsible for the coupling between skeletal angiogenesis and osteogenesis during bone remodeling are only partially elucidated. To evaluate the role of Vhl in bone homeostasis and the coupling between vascular physiology and bone, we generated mice lacking Vhl in osteochondral progenitor cells (referred to as Vhl cKO mice) at postnatal and adult stages in a tamoxifen-inducible manner and changes in skeletal morphology were assessed by micro–computed tomography (µCT), histology, and bone histomorphometry. We found that mice with inactivation of Vhl in osteochondral progenitor cells at the postnatal stage largely phenocopied that of mice lacking Vhl in mature osteoblasts, developing striking and progressive accumulation of cancellous bone with increased microvascular density and bone formation. These were accompanied with a significant increase in osteoblast proliferation, upregulation of differentiation marker Runx2 and osteocalcin, and elevated expression of vascular endothelial growth factor (VEGF) and phosphorylation of Smad1/5/8. In addition, we found that Vhl deletion in osteochondral progenitor cells in adult bone protects mice from aging-induced bone loss. Our data suggest that the VHL-mediated signaling in osteochondral progenitor cells plays a critical role in bone remodeling at postnatal/adult stages through coupling osteogenesis and angiogenesis. © 2014 American Society for Bone and Mineral Research. PMID:23999831

  6. What causes bone loss?

    Science.gov (United States)

    ... Paula FJA, Black DM, Rosen CJ. Osteoporosis and bone biology. In: Melmed S, Polonsky KS, Larsen PR, Kronenberg HM, eds. Williams Textbook of Endocrinology . 13th ed. Philadelphia, PA: ... HM. Bone development and remodeling. In: Jameson JL, De Groot ...

  7. Policosanol prevents bone loss in ovariectomized rats.

    Science.gov (United States)

    Noa, M; Más, R; Mendoza, S; Gámez, R; Mendoza, N; González, J

    2004-01-01

    Osteoporosis is characterized by reduced bone mass, abnormal bone architecture and increased fracture risk. Ovariectomy impairs bone mass and metabolism in rats and ovariectomized rats are considered as a suitable model of postmenopausal osteoporosis. Mevalonate is required for producing lipoids that are important in osteoclast activity and thus drugs affecting mevalonate production can prevent bone loss in rodents. Policosanol is a cholesterol-lowering drug isolated from sugar cane wax that inhibits cholesterol biosynthesis through an indirect regulation of hydroxymethylglutaryl coenzyme A (HMG-CoA) reductase activity. The purpose of this study was to determine whether policosanol could prevent bone loss in the bones of ovariectomized rats by comparing its effects with those induced by estradiol. Sprague Dawley female rats were randomly distributed in four groups: a sham-operated group treated with Tween/H2O vehicle and three groups of ovariectomized rats treated with 17beta-estradiol (30 microg/kg/day) or policosanol (50 and 200 mg/kg/day), respectively, for 3 months. At treatment completion the rats were sacrificed, their bones removed and variables of bone resorption and formation were investigated by histomorphometry. Ovariectomy increased trabecular separation but diminished the number and thickness of trabecules. Estradiol and policosanol prevented these effects compared with ovariectomized controls. Both treatments also prevented an increase in the number of osteoclasts and their surface area induced by ovariectomy. Estradiol, but not policosanol, significantly prevented an increase of osteoblast surface area compared with ovariectomized controls. In conclusion, policosanol prevented bone loss and decreased bone resorption in ovariectomized rats, suggesting that it should be potentially useful in preventing bone loss in postmenopausal women.

  8. Interleukin-10 Inhibits Bone Resorption: A Potential Therapeutic Strategy in Periodontitis and Other Bone Loss Diseases

    Directory of Open Access Journals (Sweden)

    Qian Zhang

    2014-01-01

    Full Text Available Periodontitis and other bone loss diseases, decreasing bone volume and strength, have a significant impact on millions of people with the risk of tooth loss and bone fracture. The integrity and strength of bone are maintained through the balance between bone resorption and bone formation by osteoclasts and osteoblasts, respectively, so the loss of bone results from the disruption of such balance due to increased resorption or/and decreased formation of bone. The goal of therapies for diseases of bone loss is to reduce bone loss, improve bone formation, and then keep healthy bone density. Current therapies have mostly relied on long-term medication, exercise, anti-inflammatory therapies, and changing of the life style. However there are some limitations for some patients in the effective treatments for bone loss diseases because of the complexity of bone loss. Interleukin-10 (IL-10 is a potent anti-inflammatory cytokine, and recent studies have indicated that IL-10 can contribute to the maintenance of bone mass through inhibition of osteoclastic bone resorption and regulation of osteoblastic bone formation. This paper will provide a brief overview of the role of IL-10 in bone loss diseases and discuss the possibility of IL-10 adoption in therapy of bone loss diseases therapy.

  9. Interleukin-10 inhibits bone resorption: a potential therapeutic strategy in periodontitis and other bone loss diseases.

    Science.gov (United States)

    Zhang, Qian; Chen, Bin; Yan, Fuhua; Guo, Jianbin; Zhu, Xiaofeng; Ma, Shouzhi; Yang, Wenrong

    2014-01-01

    Periodontitis and other bone loss diseases, decreasing bone volume and strength, have a significant impact on millions of people with the risk of tooth loss and bone fracture. The integrity and strength of bone are maintained through the balance between bone resorption and bone formation by osteoclasts and osteoblasts, respectively, so the loss of bone results from the disruption of such balance due to increased resorption or/and decreased formation of bone. The goal of therapies for diseases of bone loss is to reduce bone loss, improve bone formation, and then keep healthy bone density. Current therapies have mostly relied on long-term medication, exercise, anti-inflammatory therapies, and changing of the life style. However there are some limitations for some patients in the effective treatments for bone loss diseases because of the complexity of bone loss. Interleukin-10 (IL-10) is a potent anti-inflammatory cytokine, and recent studies have indicated that IL-10 can contribute to the maintenance of bone mass through inhibition of osteoclastic bone resorption and regulation of osteoblastic bone formation. This paper will provide a brief overview of the role of IL-10 in bone loss diseases and discuss the possibility of IL-10 adoption in therapy of bone loss diseases therapy.

  10. Bone mass loss is associated with systolic blood pressure in postmenopausal women with type 2 diabetes in Tibet: a retrospective cross-sectional study.

    Science.gov (United States)

    Zhou, L; Song, J; Yang, S; Meng, S; Lv, X; Yue, J; Mina, A; Puchi, B; Geng, Y; Yang, L

    2017-05-01

    We conducted an observational cross-section study to investigate the status of bone mineral mass of Tibetan postmenopausal women with type 2 diabetes and the possible predictors for osteoporosis. We found that prevalence of osteoporosis was 27.0% and blood pressure was an independent risk factor for bone mass loss. The aims of this study is to investigate the prevalence of osteoporosis in postmenopausal women with type 2 diabetes dwelling in Tibet and the possible risk factors for bone mass loss. We recruited 99 Chinese Tibetan postmenopausal women with type 2 diabetes from the department of endocrinology of People's Hospital Tibet Autonomous Region. Multiple sites of bone mineral density (BMD) were measured by dual-energy X-ray absorptiometry (DXA). The subjects were divided into three groups based on BMD T-score: osteoporosis, osteopenia, and normal. The clinical characteristics were compared between groups. The risk factors for bone mass loss were assessed by multiple linear regression analysis. Among diabetic postmenopausal women dwelling in high altitude, mean age was 62 ± 8 years, the median postmenopausal period was 12 years (5, 20), the median duration of diabetes mellitus was 3 years (1, 8), and mean BMI was 27.6 ± 4.2 kg/m 2 . Patients (52.5%) had hypertension. The percentages of patients with osteoporosis, osteopenia and normal BMD were 27.3, 42.4, and 30.3%, respectively. HbA1c and systolic blood pressure (SBP) were independently associated with T-scores of spine; ages and SBP were independently associated with T-scores of femoral neck or hip. Among diabetic postmenopausal women dwelling in high altitude, 27.3% patients have osteoporosis, 42.4% patients have osteopenia, and 30.3% are normal. The BMD T-score of spine was inversely associated with SBP and positively associated with HbA1c, while the BMD T-score of femoral neck or hip was inversely associated with ages and SBP.

  11. Mass Loss from Betelgeuse

    Science.gov (United States)

    Richards, A. M. S.

    2013-05-01

    Betelgeuse is just starting to produce a wind which is thick enough to form dust. However, the grains seem to coalesce at much greater distances than those in "dust-driven" winds from later-stage AGB and RSG stars. Is the mass loss mechanism different, and how will it evolve? We know a great deal about the kinematics of the more evolved winds, thanks to sub-au imaging using masers, and easily-resolved CO shells, but Betelgeuse is a much fainter target, only resolved with great difficulty (although ALMA will change that). On the other hand, Betelgeuse was the first star other than the Sun to be imaged in detail in the radio as well as optical. Radio studies from the photosphere to the astropause will reveal: How is mass lost from the stellar surface? In what form is this returned to the ISM? These results could even help to answer: How will Betelgeuse evolve in the next few millennia?

  12. Bone mass and turnover in fibromyalgia

    DEFF Research Database (Denmark)

    Jacobsen, Søren; Gam, A; Egsmose, C

    1993-01-01

    Physical inactivity accelerates bone loss. Since patients with fibromyalgia are relatively physically inactive, bone mass and markers of bone metabolism were determined in 12 premenopausal women with fibromyalgia and in healthy age matched female control subjects. No differences were found...... in lumbar bone mineral density, femoral neck bone mineral density, serum levels of alkaline phosphatase, osteocalcin, ionized calcium and phosphate. The urinary excretion of both hydroxyproline and calcium relative to urinary creatinine excretion was significantly higher in patients with fibromyalgia, p = 0.......01. This was linked to lower urinary creatinine excretion (p = 0.02) probably reflecting lower physical activity in the patients with fibromyalgia. We conclude that bone mass and turnover are generally not affected in premenopausal women with fibromyalgia....

  13. Bone mass in patients with rheumatoid arthritis

    International Nuclear Information System (INIS)

    Steen-Hansen, E.; Hove, B.; Andresen, J.; Kommunehospitalet, Aarhus

    1987-01-01

    Bone loss was evaluated in 118 patients with rheumatoid arthritis by measurement of the total width and marrow cavity of the second metacarpal bone. Both in men and women a significant increase in width of the medullary cavity could be demonstrated, probably due to bone loss at the endosteal surface. Although a certain increase in the total width of the second metacarpal bone took place in men but not in women, combined cortical thickness and metacarpal bone mass decreased significantly. There was no significant difference in the values in patients on gold treatment and in patients without systemic treatment, while patients treated with steroids demonstrated a significantly greater loss of endosteal bone compared to the other two groups. Some correlation was found between the severity of joint involvement and the measured loss of cortical bone. In summary, the study shows that bone loss takes place in patients with rheumatoid arthritis, being most pronounced in steroid-treated patients, in postmenopausal women, and in patients with more severe joint involvement. (orig.)

  14. Bisphosphonates as a Countermeasure to Space Flight Induced Bone Loss

    Science.gov (United States)

    LeBlanc, Adrian; Matsumoto, Toshio; Jones, Jeff; Shapiro, Jay; Lang, Tom; Smith, Scott M.; Shackelford, Linda C.; Sibonga, Jean; Evans, Harlan; Spector, Elisabeth; hide

    2011-01-01

    Experiment Hypothesis -- The combined effect of anti-resorptive drugs plus in-flight exercise regimen will have a measurable effect in preventing space flight induced bone mass and strength loss and reducing renal stone risk.

  15. The osteoimmunology of alveolar bone loss.

    Science.gov (United States)

    Tompkins, Kevin A

    2016-01-01

    The mineralized structure of bone undergoes constant remodeling by the balanced actions of bone-producing osteoblasts and bone-resorbing osteoclasts (OCLs). Physiologic bone remodeling occurs in response to the body's need to respond to changes in electrolyte levels, or mechanical forces on bone. There are many pathological conditions, however, that cause an imbalance between bone production and resorption due to excessive OCL action that results in net bone loss. Situations involving chronic or acute inflammation are often associated with net bone loss, and research into understanding the mechanisms regulating this bone loss has led to the development of the field of osteoimmunology. It is now evident that the skeletal and immune systems are functionally linked and share common cells and signaling molecules. This review discusses the signaling system of immune cells and cytokines regulating aberrant OCL differentiation and activity. The role of these cells and cytokines in the bone loss occurring in periodontal disease (PD) (chronic inflammation) and orthodontic tooth movement (OTM) (acute inflammation) is then described. The review finishes with an exploration of the emerging role of Notch signaling in the development of the immune cells and OCLs that are involved in osteoimmunological bone loss and the research into Notch signaling in OTM and PD.

  16. Alveolar bone loss in obese subjects.

    Science.gov (United States)

    Alabdulkarim, Maher; Bissada, Nabil; Al-Zahrani, Mohammad; Ficara, Anthony; Siegel, Burton

    2005-04-01

    Obesity was found to be significantly associated with periodontal disease prevalence as measured by probing depth and clinical attachment loss. The aim of this study was to examine if obesity correlates with chronic periodontitis as diagnosed by radiographic alveolar bone loss. Four hundred subjects > or =18 years old were included; 200 with body mass index (BMI) > or =30 kg/m2 (obese) and 200 with BMI periodontitis. Obesity was found to be significantly associated with periodontitis in the uni-variate regression analysis (OR = 2.37, 95% CI, 1.55-3.63). After adjusting for age, gender, smoking, employment, diabetes, marital status, and number of teeth present, obese subjects were found to be 1.86 times more likely to have periodontitis (95% CI, 0.99-3.51) than non-obese ones. When the sample was stratified based on age, the multivariate association was statistically significant among individuals or = 40 years of age the association was statistically insignificant (OR = 1.06, 95% CI, 0.57-1.95). Stratifying the sample based on gender and smoking status revealed a stronger association among females than males (OR = 3.14 vs. 1.95) and among non-smokers than smokers (OR = 3.36 vs. 2.22). Obesity is associated with increased prevalence of periodontitis as measured by radiographic alveolar bone loss, especially among younger individuals. Prevention and management of obesity may be considered to promote better systemic and periodontal health.

  17. Horizontal alveolar bone loss: A periodontal orphan

    Directory of Open Access Journals (Sweden)

    Jayakumar A

    2010-01-01

    Full Text Available Background: Attempts to successfully regenerate lost alveolar bone have always been a clinician′s dream. Angular defects, at least, have a fairer chance, but the same cannot be said about horizontal bone loss. The purpose of the present study was to evaluate the prevalence of horizontal alveolar bone loss and vertical bone defects in periodontal patients; and later, to correlate it with the treatment modalities available in the literature for horizontal and vertical bone defects. Materials and Methods: The study was conducted in two parts. Part I was the radiographic evaluation of 150 orthopantomographs (OPGs (of patients diagnosed with chronic periodontitis and seeking periodontal care, which were digitized and read using the AutoCAD 2006 software. All the periodontitis-affected teeth were categorized as teeth with vertical defects (if the defect angle was ≤45° and defect depth was ≥3 mm or as having horizontal bone loss. Part II of the study comprised search of the literature on treatment modalities for horizontal and vertical bone loss in four selected periodontal journals. Results: Out of the 150 OPGs studied, 54 (36% OPGs showed one or more vertical defects. Totally, 3,371 teeth were studied, out of which horizontal bone loss was found in 3,107 (92.2% teeth, and vertical defects were found only in 264 (7.8% of the teeth, which was statistically significant (P<.001. Search of the selected journals revealed 477 papers have addressed the treatment modalities for vertical and horizontal types of bone loss specifically. Out of the 477 papers, 461 (96.3% have addressed vertical bone loss, and 18 (3.7% have addressed treatment options for horizontal bone loss. Two papers have addressed both types of bone loss and are included in both categories. Conclusion: Horizontal bone loss is more prevalent than vertical bone loss but has been sidelined by researchers as very few papers have been published on the subject of regenerative treatment

  18. Probiotics protect mice from ovariectomy-induced cortical bone loss.

    Directory of Open Access Journals (Sweden)

    Claes Ohlsson

    Full Text Available The gut microbiota (GM modulates the hosts metabolism and immune system. Probiotic bacteria are defined as live microorganisms which when administered in adequate amounts confer a health benefit on the host and can alter the composition of the GM. Germ-free mice have increased bone mass associated with reduced bone resorption indicating that the GM also regulates bone mass. Ovariectomy (ovx results in bone loss associated with altered immune status. The purpose of this study was to determine if probiotic treatment protects mice from ovx-induced bone loss. Mice were treated with either a single Lactobacillus (L strain, L. paracasei DSM13434 (L. para or a mixture of three strains, L. paracasei DSM13434, L. plantarum DSM 15312 and DSM 15313 (L. mix given in the drinking water during 6 weeks, starting two weeks before ovx. Both the L. para and the L. mix treatment protected mice from ovx-induced cortical bone loss and bone resorption. Cortical bone mineral content was higher in both L. para and L. mix treated ovx mice compared to vehicle (veh treated ovx mice. Serum levels of the resorption marker C-terminal telopeptides and the urinary fractional excretion of calcium were increased by ovx in the veh treated but not in the L. para or the L. mix treated mice. Probiotic treatment reduced the expression of the two inflammatory cytokines, TNFα and IL-1β, and increased the expression of OPG, a potent inhibitor of osteoclastogenesis, in cortical bone of ovx mice. In addition, ovx decreased the frequency of regulatory T cells in bone marrow of veh treated but not probiotic treated mice. In conclusion, treatment with L. para or the L. mix prevents ovx-induced cortical bone loss. Our findings indicate that these probiotic treatments alter the immune status in bone resulting in attenuated bone resorption in ovx mice.

  19. Bone Mass Measurement: What the Numbers Mean

    Science.gov (United States)

    ... the Test Do? The T-Score World Health Organization Definitions Based on Bone Density Levels Low Bone Mass ... number, the more severe the osteoporosis. World Health Organization Definitions Based on Bone Density Levels Level Definition Normal ...

  20. A multi-method assessment of bone maintenance and loss in an Imperial Roman population: Implications for future studies of age-related bone loss in the past.

    Science.gov (United States)

    Beauchesne, Patrick; Agarwal, Sabrina C

    2017-09-01

    One of the hallmarks of contemporary osteoporosis and bone loss is dramatically higher prevalence of loss and fragility in females post-menopause. In contrast, bioarchaeological studies of bone loss have found a greater diversity of age- and sex-related patterns of bone loss in past populations. We argue that the differing findings may relate to the fact that most studies use only a single methodology to quantify bone loss and do not account for the heterogeneity and complexity of bone maintenance across the skeleton and over the life course. We test the hypothesis that bone mass and maintenance in trabecular bone sites versus cortical bone sites will show differing patterns of age-related bone loss, with cortical bone sites showing sex difference in bone loss that are similar to contemporary Western populations, and trabecular bone loss at earlier ages. We investigated this hypothesis in the Imperial Roman population of Velia using three methods: radiogrammetry of the second metacarpal (N = 71), bone histology of ribs (N = 70), and computerized tomography of trabecular bone architecture (N = 47). All three methods were used to explore sex and age differences in patterns of bone loss. The suite of methods utilized reveal differences in the timing of bone loss with age, but all methods found no statistically significant differences in age-related bone loss. We argue that a multi-method approach reduces the influence of confounding factors by building a reconstruction of bone turnover over the life cycle that a limited single-method project cannot provide. The implications of using multiple methods beyond studies of bone loss are also discussed. © 2017 Wiley Periodicals, Inc.

  1. Mass loss from Eta Carinae

    International Nuclear Information System (INIS)

    Andriesse, C.D.; Viotti, R.

    1979-01-01

    This high luminosity (5x10 6 solar luminosity) star since 1840 is losing mass at the rate of 7.5x10 -2 solar masses per year. The large mass loss could be the result of vibrational instabilities produced in the CNO hydrogen burning phase of a very massive (160 solar masses) star. The presence of high excitation lines in the ultraviolet spectrum of Eta Car suggests the idea of a hot zone excited by dissipation of the supersonic turbulent flow. (Auth.)

  2. Bed Rest and Immobilization: Risk Factors for Bone Loss

    Science.gov (United States)

    ... Risk Factors for Bone Loss Bed Rest and Immobilization: Risk Factors for Bone Loss Like muscle, bone ... complications of pregnancy; and those who are experiencing immobilization of some part of the body because of ...

  3. Sclerostin Antibody Reverses Bone Loss by Increasing Bone Formation and Decreasing Bone Resorption in a Rat Model of Male Osteoporosis.

    Science.gov (United States)

    Li, Xiaodong; Ominsky, Michael S; Villasenor, Kelly S; Niu, Qing-Tian; Asuncion, Frank J; Xia, Xuechun; Grisanti, Mario; Wronski, Thomas J; Simonet, W Scott; Ke, Hua Zhu

    2018-01-01

    Sclerostin antibody (Scl-Ab) restored bone mass and strength in the ovariectomized rat model of postmenopausal osteoporosis. Increased bone mineral density (BMD) and decreased skeletal fragility fracture risk have been reported in postmenopausal osteoporotic women receiving Scl-Ab. In males, loss of androgen leads to rapid decreases in BMD and an increased risk of fragility fractures. We hypothesized that Scl-Ab could reverse the loss of bone mass and strength caused by androgen ablation in the orchiectomized (ORX) rat model of male osteoporosis. We treated 9-month-old ORX Sprague Dawley rats (3 months after ORX) subcutaneously twice weekly with vehicle or Scl-Ab (5 or 25 mg/kg) for 6 weeks (n = 10 per group). Both doses of Scl-Ab fully reversed the BMD deficit in the lumbar spine and femur and tibia in ORX rats. Microcomputed tomography showed that the bone mass in the fifth lumbar vertebral body, femur diaphysis, and femoral neck were dose-dependently restored by Scl-Ab. The bone strength at these sites increased significantly with Scl-Ab to levels matching those of sham-operated controls and correlated positively with improvements in bone mineral content, demonstrating bone quality maintenance. Dynamic histomorphometry of the tibial diaphysis and second lumbar vertebral body demonstrated that Scl-Ab significantly increased bone formation on periosteal, endocortical, and trabecular surfaces and significantly decreased bone resorption on endocortical and trabecular surfaces. The effects of Scl-Ab on increasing bone formation and decreasing bone resorption led to restoration of bone mass and strength in androgen-deficient rats. These findings support the ongoing evaluation of Scl-Ab as a potential therapeutic agent for osteoporosis in men. Copyright © 2018 Endocrine Society.

  4. Body Mass Influences Cortical Bone Mass Independent of Leptin Signaling

    OpenAIRE

    Iwaniec, U.T.; Dube, M.G.; Boghossian, S.; Song, H.; Helferich, W.G.; Turner, R.T.; Kalra, S.P.

    2008-01-01

    Obesity in humans is associated with increased bone mass. Leptin, a hormone produced by fat cells, functions as a sentinel of energy balance, and may mediate the putative positive effects of body mass on bone. We performed studies in male C57Bl/6 wild type (WT) and leptin-deficient ob/ob mice to determine whether body mass gain induced by high fat intake increases bone mass and, if so, whether this requires central leptin signaling. The relationship between body mass and bone mass and archite...

  5. Rate of bone loss in postmenopausal and osteoporotic women

    International Nuclear Information System (INIS)

    Aloia, J.F.; Ross, P.; Vaswani, A.; Zanzi, I.; Cohn, S.H.

    1982-01-01

    Regional and total bone mass were determined in three groups of women by photon absorptiometry of the distal radius [bone mineral content (BMC)] and total neutron activation analysis [total body calcium (TBCa)], respectively. There were three groups of patients: group A, osteoporotic women treated with a variety of pharmacologic agents; group B, osteoporotic women (controls) taking only calcium supplements; and group C, normal postmenopausal women. The mean TBCa and BMC were considerably higher in the postmenopausal women than in the osteoporotic women. The rate of change of bone mass in group C was -0.45%/yr and -0.9%/yr for the total skeleton and radius, respectively. Group B had no significant rate of loss, whereas group A demonstrated a significant increase in TBCa of 0.75%/yr with no change in the BMC of the radius. There were no significant between-subject correlations for the slopes (rates of change) of the two bone mineral measurements

  6. Interleukin-10 Inhibits Bone Resorption: A Potential Therapeutic Strategy in Periodontitis and Other Bone Loss Diseases

    OpenAIRE

    Zhang, Qian; Chen, Bin; Yan, Fuhua; Guo, Jianbin; Zhu, Xiaofeng; Ma, Shouzhi; Yang, Wenrong

    2014-01-01

    Periodontitis and other bone loss diseases, decreasing bone volume and strength, have a significant impact on millions of people with the risk of tooth loss and bone fracture. The integrity and strength of bone are maintained through the balance between bone resorption and bone formation by osteoclasts and osteoblasts, respectively, so the loss of bone results from the disruption of such balance due to increased resorption or/and decreased formation of bone. The goal of therapies for diseases...

  7. Vitamin C reverses hypogonadal bone loss

    Science.gov (United States)

    Epidemiologic studies correlate low vitamin C intake with bone loss. The genetic deletion of enzymes involved in de novo vitamin C synthesis in mice, likewise, causes severe osteoporosis. However, very few studies have evaluated a protective role of this dietary supplement on the skeleton. Here, ...

  8. Lrp5 functions in bone to regulate bone mass.

    Science.gov (United States)

    Cui, Yajun; Niziolek, Paul J; MacDonald, Bryan T; Zylstra, Cassandra R; Alenina, Natalia; Robinson, Daniel R; Zhong, Zhendong; Matthes, Susann; Jacobsen, Christina M; Conlon, Ronald A; Brommage, Robert; Liu, Qingyun; Mseeh, Faika; Powell, David R; Yang, Qi M; Zambrowicz, Brian; Gerrits, Han; Gossen, Jan A; He, Xi; Bader, Michael; Williams, Bart O; Warman, Matthew L; Robling, Alexander G

    2011-06-01

    The human skeleton is affected by mutations in low-density lipoprotein receptor-related protein 5 (LRP5). To understand how LRP5 influences bone properties, we generated mice with osteocyte-specific expression of inducible Lrp5 mutations that cause high and low bone mass phenotypes in humans. We found that bone properties in these mice were comparable to bone properties in mice with inherited mutations. We also induced an Lrp5 mutation in cells that form the appendicular skeleton but not in cells that form the axial skeleton; we observed that bone properties were altered in the limb but not in the spine. These data indicate that Lrp5 signaling functions locally, and they suggest that increasing LRP5 signaling in mature bone cells may be a strategy for treating human disorders associated with low bone mass, such as osteoporosis.

  9. Bone Loss Among Women Living With HIV.

    Science.gov (United States)

    Weitzmann, M Neale; Ofotokun, Ighovwerha; Titanji, Kehmia; Sharma, Anjali; Yin, Michael T

    2016-12-01

    Clinical data accumulated over the past two decades attests to a significant decline in bone mineral density (BMD) in patients infected by HIV, which does not remit but may actually intensify with anti-retroviral therapy (ART). Long generally perceived as an aberration without clinical consequences in relatively young HIV-infected cohorts, recent studies have documented marked increases in fracture incidence in HIV-infected men and women over a wide age continuum. Fractures are associated with chronic pain, crippling morbidity, and increased mortality, undermining the gains in quality of life achieved though ART. As bone loss and resulting increases in fracture incidence are a natural consequence of aging, there is now concern regarding the long-term consequences of HIV/ART-associated premature bone loss, given the transition of the HIV/AIDS population into an older age demographic. The development of guidelines for diagnosis and treatment of bone disease within the context of HIV and ART has been an important recent step in raising awareness of the problem and the implications of bone fracture for patient health. Significant progress has also been made in recent years in dissecting the complex and multifactorial mechanisms driving bone loss in HIV/ART and the role of underlying immunological disruption in skeletal dysmorphogenesis. This review examines recent progress in the field and studies by Women's Interagency HIV Study (WIHS)-associated investigators, inside and outside of the WIHS cohort, aimed at identifying skeletal abnormalities, quantifying facture incidence, management, and understanding underlying mechanisms in people living with HIV in the context of chronic ART.

  10. Donepezil regulates energy metabolism and favors bone mass accrual.

    Science.gov (United States)

    Eimar, Hazem; Alebrahim, Sharifa; Manickam, Garthiga; Al-Subaie, Ahmed; Abu-Nada, Lina; Murshed, Monzur; Tamimi, Faleh

    2016-03-01

    The autonomous nervous system regulates bone mass through the sympathetic and parasympathetic arms. The sympathetic nervous system (SNS) favors bone loss whereas the parasympathetic nervous system (PNS) promotes bone mass accrual. Donepezil, a central-acting cholinergic agonist, has been shown to down-regulate SNS and up-regulate PNS signaling tones. Accordingly, we hypothesize that the use of donepezil could have beneficial effects in regulating bone mass. To test our hypothesis, two groups of healthy female mice were treated either with donepezil or saline. Differences in body metabolism and bone mass of the treated groups were compared. Body and visceral fat weights as well as serum leptin level were increased in donepezil-treated mice compared to control, suggesting that donepezil effects on SNS influenced metabolic activity. Donepezil-treated mice had better bone quality than controls due to a decrease in osteoclasts number. These results indicate that donepezil is able to affect whole body energy metabolism and favors bone mass in young female WT mice. Copyright © 2015 Elsevier Inc. All rights reserved.

  11. Suppressed bone remodeling in black bears conserves energy and bone mass during hibernation.

    Science.gov (United States)

    McGee-Lawrence, Meghan; Buckendahl, Patricia; Carpenter, Caren; Henriksen, Kim; Vaughan, Michael; Donahue, Seth

    2015-07-01

    Decreased physical activity in mammals increases bone turnover and uncouples bone formation from bone resorption, leading to hypercalcemia, hypercalcuria, bone loss and increased fracture risk. Black bears, however, are physically inactive for up to 6 months annually during hibernation without losing cortical or trabecular bone mass. Bears have been shown to preserve trabecular bone volume and architectural parameters and cortical bone strength, porosity and geometrical properties during hibernation. The mechanisms that prevent disuse osteoporosis in bears are unclear as previous studies using histological and serum markers of bone remodeling show conflicting results. However, previous studies used serum markers of bone remodeling that are known to accumulate with decreased renal function, which bears have during hibernation. Therefore, we measured serum bone remodeling markers (BSALP and TRACP) that do not accumulate with decreased renal function, in addition to the concentrations of serum calcium and hormones involved in regulating bone remodeling in hibernating and active bears. Bone resorption and formation markers were decreased during hibernation compared with when bears were physically active, and these findings were supported by histomorphometric analyses of bone biopsies. The serum concentration of cocaine and amphetamine regulated transcript (CART), a hormone known to reduce bone resorption, was 15-fold higher during hibernation. Serum calcium concentration was unchanged between hibernation and non-hibernation seasons. Suppressed and balanced bone resorption and formation in hibernating bears contributes to energy conservation, eucalcemia and the preservation of bone mass and strength, allowing bears to survive prolonged periods of extreme environmental conditions, nutritional deprivation and anuria. © 2015. Published by The Company of Biologists Ltd.

  12. Regulators of G protein signaling 12 promotes osteoclastogenesis in bone remodeling and pathological bone loss.

    Science.gov (United States)

    Yuan, X; Cao, J; Liu, T; Li, Y-P; Scannapieco, F; He, X; Oursler, M J; Zhang, X; Vacher, J; Li, C; Olson, D; Yang, S

    2015-12-01

    Regulators of G protein signaling (Rgs) have pivotal roles in controlling various cellular processes, such as cell differentiation. How Rgs proteins regulate osteoclast (OC) differentiation, function and bone homeostasis is poorly understood. It was previously demonstrated that Rgs12, the largest protein in the Rgs family, is predominantly expressed in OCs and regulates OC differentiation in vitro. To further understand the role and mechanism of Rgs12 in OC differentiation and bone diseases in vivo, we created OC-targeted Rgs12 knockout mice by using inducible Mx1-Cre and CD11b-Cre. Deletion of Rgs12 in hematopoietic cells or specifically in OC precursors resulted in increased bone mass with decreased OC numbers. Loss of Rgs12 impaired OC differentiation and function with impaired Ca(2+) oscillations and reduced nuclear factor of activated T cells (NFAT) 2 expression. The introduction of wild-type osteoblasts did not rescue the defective osteoclastogenesis. Ectopic expression of NFAT2 rescued defective OC differentiation in CD11b;Rgs12(fl/fl) cells and promoted normal OC differentiation. Moreover, deletion of Rgs12 significantly inhibited pathological osteoclastogenesis and bone destruction in Rgs12-deficient mice that were subjected to ovariectomy and lipodysaccharide for bone loss. Thus our findings demonstrate that Rgs12 is an important regulator in OC differentiation and function and identify Rgs12 as a potential therapeutic target for osteoporosis and inflammation-induced bone loss.

  13. Mass loss from Wolf-Rayet stars

    International Nuclear Information System (INIS)

    Willis, A.J.

    1982-01-01

    Recent results relating to the stellar winds and mass loss rates of the WR stars are reviewed, emphasising new data and their interpretation acquired at UV, IR and Radio wavelengths. The subject is discussed under the headings: physical and chemical properties of WR stars (effective temperatures and radiative luminosities; masses; chemical abundances); velocity, ionisation and excitation structure of WR winds; mass loss rates of WR stars; mass loss properties of WR stars in the LMC; comparisons with theoretical models of mass loss; ring nebulae around WR stars; conclusions. (author)

  14. Bone mass and turnover in fibromyalgia

    DEFF Research Database (Denmark)

    Jacobsen, Søren; Gam, A; Egsmose, C

    1993-01-01

    in lumbar bone mineral density, femoral neck bone mineral density, serum levels of alkaline phosphatase, osteocalcin, ionized calcium and phosphate. The urinary excretion of both hydroxyproline and calcium relative to urinary creatinine excretion was significantly higher in patients with fibromyalgia, p = 0.......01. This was linked to lower urinary creatinine excretion (p = 0.02) probably reflecting lower physical activity in the patients with fibromyalgia. We conclude that bone mass and turnover are generally not affected in premenopausal women with fibromyalgia....

  15. Monosodium glutamate-sensitive hypothalamic neurons contribute to the control of bone mass

    Science.gov (United States)

    Elefteriou, Florent; Takeda, Shu; Liu, Xiuyun; Armstrong, Dawna; Karsenty, Gerard

    2003-01-01

    Using chemical lesioning we previously identified hypothalamic neurons that are required for leptin antiosteogenic function. In the course of these studies we observed that destruction of neurons sensitive to monosodium glutamate (MSG) in arcuate nuclei did not affect bone mass. However MSG treatment leads to hypogonadism, a condition inducing bone loss. Therefore the normal bone mass of MSG-treated mice suggested that MSG-sensitive neurons may be implicated in the control of bone mass. To test this hypothesis we assessed bone resorption and bone formation parameters in MSG-treated mice. We show here that MSG-treated mice display the expected increase in bone resorption and that their normal bone mass is due to a concomitant increase in bone formation. Correction of MSG-induced hypogonadism by physiological doses of estradiol corrected the abnormal bone resorptive activity in MSG-treated mice and uncovered their high bone mass phenotype. Because neuropeptide Y (NPY) is highly expressed in MSG-sensitive neurons we tested whether NPY regulates bone formation. Surprisingly, NPY-deficient mice had a normal bone mass. This study reveals that distinct populations of hypothalamic neurons are involved in the control of bone mass and demonstrates that MSG-sensitive neurons control bone formation in a leptin-independent manner. It also indicates that NPY deficiency does not affect bone mass.

  16. Regenerate augmentation with bone marrow concentrate after traumatic bone loss

    Directory of Open Access Journals (Sweden)

    Jan Gessmann

    2012-03-01

    Full Text Available Distraction osteogenesis after post-traumatic segmental bone loss of the tibia is a complex and time-consuming procedure that is often complicated due to prolonged consolidation or complete insufficiency of the regenerate. The aim of this feasibility study was to investigate the potential of bone marrow aspiration concentrate (BMAC for percutaneous regenerate augmentation to accelerate bony consolidation of the regenerate. Eight patients (age 22-64 with an average posttraumatic bone defect of 82.4 mm and concomitant risk factors (nicotine abuse, soft-tissue defects, obesity and/or circulatory disorders were treated with a modified Ilizarov external frame using an intramedullary cable transportation system. At the end of the distraction phase, each patient was treated with a percutaneously injection of autologous BMAC into the centre of the regenerate. The concentration factor was analysed using flow cytometry. The mean follow up after frame removal was 10 (4-15 months. With a mean healing index (HI of 36.9 d/cm, bony consolidation of the regenerate was achieved in all eight cases. The mean concentration factor of the bone marrow aspirate was 4.6 (SD 1.23. No further operations concerning the regenerate were needed and no adverse effects were observed with the BMAC procedure. This procedure can be used for augmentation of the regenerate in cases of segmental bone transport. Further studies with a larger number of patients and control groups are needed to evaluate a possible higher success rate and accelerating effects on regenerate healing.

  17. Lutein Enhances Bone Mass by Stimulating Bone Formation and Suppressing Bone Resorption in Growing Mice.

    Science.gov (United States)

    Takeda, Hiroshi; Tominari, Tsukasa; Hirata, Michiko; Watanabe, Kenta; Matsumoto, Chiho; Grundler, Florian M W; Inada, Masaki; Miyaura, Chisato

    2017-01-01

    Lutein is a member of the xanthophyll family of carotenoids, which are known to prevent hypoxia-induced cell damage in the eye by removing free radicals. However, its role in other tissues is controversial, and the effects of lutein on bone tissues are unknown. To identify a possible role of lutein in bone tissues, we examined the effects of lutein on bone formation and bone resorption and on femoral bone mass in mice. Lutein enhanced the formation of mineralized bone nodules in cultures of osteoblasts. On the other hand, lutein clearly suppressed 1α, 25-dihydroxyvitamin D 3 -induced bone resorption as measured by pit formation in organ culture of mouse calvaria. In co-cultures of bone marrow cells and osteoblasts, lutein suppressed 1α, 25-dihydroxyvitamin D 3 -induced osteoclast formation. In cultures of bone marrow macrophages, lutein suppressed soluble RANKL, the receptor activator of nuclear factor-kappaB (NF-κB) ligand, induced osteoclast formation. When five-week-old male mice were orally administered lutein for 4 weeks, the femoral bone mass was clearly enhanced in cortical bone, as measured by bone mineral density in dual X-ray absorptiometry and micro computed tomography (µCT) analyses. The present study indicates that lutein enhances bone mass in growing mice by suppressing bone resorption and stimulating bone formation. Lutein may be a natural agent that promotes bone turnover and may be beneficial for bone health in humans.

  18. Evaluating Bone Loss in ISS Astronauts.

    Science.gov (United States)

    Sibonga, Jean D; Spector, Elisabeth R; Johnston, Smith L; Tarver, William J

    2015-12-01

    The measurement of bone mineral density (BMD) by dual-energy X-ray absorptiometry (DXA) is the Medical Assessment Test used at the NASA Johnson Space Center to evaluate whether prolonged exposure to spaceflight increases the risk for premature osteoporosis in International Space Station (ISS) astronauts. The DXA scans of crewmembers' BMD during the first decade of the ISS existence showed precipitous declines in BMD for the hip and spine after the typical 6-mo missions. However, a concern exists that skeletal integrity cannot be sufficiently assessed solely by DXA measurement of BMD. Consequently, use of relatively new research technologies is being proposed to NASA for risk surveillance and to enhance long-term management of skeletal health in long-duration astronauts. Sibonga JD, Spector ER, Johnston SL, Tarver WJ. Evaluating bone loss in ISS astronauts.

  19. Bone loss and human adaptation to lunar gravity

    Science.gov (United States)

    Keller, T. S.; Strauss, A. M.

    1992-01-01

    Long-duration space missions and establishment of permanently manned bases on the Moon and Mars are currently being planned. The weightless environment of space and the low-gravity environments of the Moon and Mars pose an unknown challenge to human habitability and survivability. Of particular concern in the medical research community today is the effect of less than Earth gravity on the human skeleton, since the limits, if any, of human endurance in low-gravity environments are unknown. This paper provides theoretical predictions on bone loss and skeletal adaptation to lunar and other nonterrestrial-gravity environments based upon the experimentally derived relationship, density approximately (mass x gravity)(exp 1/8). The predictions are compared to skeletal changes reported during bed rest, immobilization, certrifugation, and spaceflight. Countermeasures to reduce bone losses in fractional gravity are also discussed.

  20. Sclerostin antibody treatment increases bone formation, bone mass, and bone strength in a rat model of postmenopausal osteoporosis.

    Science.gov (United States)

    Li, Xiaodong; Ominsky, Michael S; Warmington, Kelly S; Morony, Sean; Gong, Jianhua; Cao, Jin; Gao, Yongming; Shalhoub, Victoria; Tipton, Barbara; Haldankar, Raj; Chen, Qing; Winters, Aaron; Boone, Tom; Geng, Zhaopo; Niu, Qing-Tian; Ke, Hua Zhu; Kostenuik, Paul J; Simonet, W Scott; Lacey, David L; Paszty, Chris

    2009-04-01

    The development of bone-rebuilding anabolic agents for potential use in the treatment of bone loss conditions, such as osteoporosis, has been a long-standing goal. Genetic studies in humans and mice have shown that the secreted protein sclerostin is a key negative regulator of bone formation, although the magnitude and extent of sclerostin's role in the control of bone formation in the aging skeleton is still unclear. To study this unexplored area of sclerostin biology and to assess the pharmacologic effects of sclerostin inhibition, we used a cell culture model of bone formation to identify a sclerostin neutralizing monoclonal antibody (Scl-AbII) for testing in an aged ovariectomized rat model of postmenopausal osteoporosis. Six-month-old female rats were ovariectomized and left untreated for 1 yr to allow for significant estrogen deficiency-induced bone loss, at which point Scl-AbII was administered for 5 wk. Scl-AbII treatment in these animals had robust anabolic effects, with marked increases in bone formation on trabecular, periosteal, endocortical, and intracortical surfaces. This not only resulted in complete reversal, at several skeletal sites, of the 1 yr of estrogen deficiency-induced bone loss, but also further increased bone mass and bone strength to levels greater than those found in non-ovariectomized control rats. Taken together, these preclinical results establish sclerostin's role as a pivotal negative regulator of bone formation in the aging skeleton and, furthermore, suggest that antibody-mediated inhibition of sclerostin represents a promising new therapeutic approach for the anabolic treatment of bone-related disorders, such as postmenopausal osteoporosis.

  1. The correlation between postmenopausal osteoporosis and inflammatory periodontitis regarding bone loss in experimental models.

    Science.gov (United States)

    Kobayashi, Megumi; Matsumoto, Chiho; Hirata, Michiko; Tominari, Tsukasa; Inada, Masaki; Miyaura, Chisato

    2012-01-01

    We have invented a mouse model of periodontitis associated with alveolar bone loss induced by lipopolysaccharide. Ovariectomized (OVX) animals are widely used as a model for osteoporosis due to estrogen deficiency. To define the relationship between periodontitis and osteoporosis, we examined the influence of estrogen deficiency on the mouse alveolar bone mass. In OVX mice, bone loss was detected not only in the femur, but also in the alveolar bone, indicating that estrogen deficiency could induce resorption in alveolar bone. In experiments using a combination of osteoporosis and periodontitis models, OVX significantly enhanced the alveolar bone loss in the model of periodontitis. Therefore, postmenopausal osteoporosis may enhance the risk of periodontitis associated with inflammatory alveolar bone resorption.

  2. Feeding blueberry diets during early development is sufficient to prevent senescence of osteoblasts and bone loss in adulthood

    Science.gov (United States)

    Appropriate nutrition during early development is essential for optimal bone mass accretion; however, linkage between early nutrition, childhood bone mass and prevention of bone loss later in life has not been extensively studied. In this report, we show that feeding a high quality diet supplemented...

  3. Feeding Blueberry Diets in Early Life Prevent Senescence of Osteoblasts and Bone Loss in Ovariectomized Adult Female Rats

    Science.gov (United States)

    Appropriate nutrition during early development is essential for optimal bone mass accretion; however, linkage between early nutrition, childhood bone mass and prevention of bone loss later in life has not been extensively studied. In this report, we show that feeding a high quality diet supplemented...

  4. GLP-1 receptor agonist treatment increases bone formation and prevents bone loss in weight-reduced obese women

    DEFF Research Database (Denmark)

    Iepsen, Eva Pers Winning; Lundgren, Julie Rehné; Hartmann, Bolette

    2015-01-01

    bone mass reductions. DESIGN: Randomized control study. SETTING: Out-patient research hospital clinic. PARTICIPANTS: Thirty-seven healthy obese women. BMI 34±0.5 kg/m(2), age 46±2 years. INTERVENTION: After a low-calorie diet-induced 12% weight loss, participants were randomized to treatment......CONTEXT: Recent studies indicate that glucagon-like peptide 1 (GLP-1) regulates bone turnover, but the effects of GLP-1 receptor agonists (GLP-1 RAs) on bone in obese weight-reduced individuals are unknown. OBJECTIVE: To investigate the role of GLP-1 RAs on bone formation and weight loss induced...... markers (CTX-1 and P1NP) were investigated before, after weight loss and after 52 weeks weight maintenance. Primary end points: Change in BMC and bone markers after 52 weeks weight maintenance with or without GLP-1 RA treatment. RESULTS: Total, pelvic and arm-leg BMC decreased during weight maintenance...

  5. Clinical assessment of bone mass in children

    Directory of Open Access Journals (Sweden)

    L A Sheplyagina

    2005-01-01

    Full Text Available Objective. To give clinical assessment of bone mass main indices in healthy children living in Moscow and Moscow region. Material and methods. 357 healthy children aged 5-16 years (194 male, 163 female were included. Physical development, bone mineral density (BMD by 2-power radiological absorptiometry, bone mineral content (BMC were evaluated. Results. Significant variability of height in children age groups was revealed. 40,2% had disharmonious physical development. BMC and BMD were closely associated with height (r=0,8, p=0,0001 and body mass (r=0,7, p=0,0001. Bone mass indices were proved to be significantly less in children with height and body mass less then 10% percentile. BMD growth rate was less than mineral accumulation rate. Method of body mass clinical assessment in children was elaborated. Conclusion. Application of elaborated tables of conjugated values of anthropometric and densitometric indices allows to decrease of osteopenia overdiagnosis in children and determine causes of insufficient bone mineral content.

  6. Do vegetarians have a normal bone mass?

    Science.gov (United States)

    New, Susan A

    2004-09-01

    Public health strategies targeting the prevention of poor bone health on a population-wide basis are urgently required, with particular emphasis being placed on modifiable factors such as nutrition. The aim of this review was to assess the impact of a vegetarian diet on indices of skeletal integrity to address specifically whether vegetarians have a normal bone mass. Analysis of existing literature, through a combination of observational, clinical and intervention studies were assessed in relation to bone health for the following: lacto-ovo-vegetarian and vegan diets versus omnivorous, predominantly meat diets, consumption of animal versus vegetable protein, and fruit and vegetable consumption. Mechanisms of action for a dietary "component" effect were examined and other potential dietary differences between vegetarians and non-vegetarians were also explored. Key findings included: (i) no differences in bone health indices between lacto-ovo-vegetarians and omnivores; (ii) conflicting data for protein effects on bone with high protein consumption (particularly without supporting calcium/alkali intakes) and low protein intake (particularly with respect to vegan diets) being detrimental to the skeleton; (iii) growing support for a beneficial effect of fruit and vegetable intake on bone, with mechanisms of action currently remaining unclarified. The impact of a "vegetarian" diet on bone health is a hugely complex area since: 1) components of the diet (such as calcium, protein, alkali, vitamin K, phytoestrogens) may be varied; 2) key lifestyle factors which are important to bone (such as physical activity) may be different; 3) the tools available for assessing consumption of food are relatively weak. However, from data available and given the limitations stipulated above, "vegetarians" do certainly appear to have "normal" bone mass. What remains our challenge is to determine what components of a vegetarian diet are of particular benefit to bone, at what levels and under

  7. Regional cortical and trabecular bone loss after spinal cord injury

    OpenAIRE

    Dudley-Javoroski, Shauna; Shields, Richard K.

    2012-01-01

    Spinal cord injury (SCI) triggers rapid loss of trabecular bone mineral density (BMD) in bone epiphyses and a loss of cortical cross-sectional area (CSA) in bone diaphyses, increasing fracture risk for people with SCI. The purpose of this study was to measure trabecular BMD and cortical CSA loss at several previously unexamined lower-limb sites (4% fibula, 12% femur, 86% tibia, cortical) in individuals with SCI. Using peripheral quantitative computed tomography, we scanned 13 participants wit...

  8. [Regulation of bone mass by osteocyte network].

    Science.gov (United States)

    Moriishi, Takeshi; Komori, Toshihisa

    2012-05-01

    Immobilization osteoporosis is a big issue in modern societies with aging population. Mechanical stress is essential for maintaining bone mass ; however, the mechanism of the regulation of bone mass by the osteocyte network, which comprises a communication system through processes and canaliculi throughout bone, still remains to be clarified. Therefore, it is urgent to reveal the mechanism of bone mass regulation at loaded and unloaded conditions and the physiological functions of the osteocyte network on osteoblasts and osteoclasts using appropriate mouse models such as a mouse line with the disrupted osteocyte function. We identified a novel mechanical stress-responsible molecule, pyruvate dehydrogenase kinase 4 (Pdk4) , whose expression was upregulated in osteoblasts at the unloaded condition, using a mouse model with the disrupted osteocyte function. We found that Pdk4 regulates Rankl expression in osteoblasts through the signal from the osteocyte network and induces osteoclastogenesis and bone resorption at the unloaded condition. The analyses using appropriate mouse models are gradually revealing the physiological roles of the osteocyte network, which were difficult to examine for a long time because of the anatomic sites of osteocytes that are embedded in bone matrix.

  9. Using Natural Stable Calcium Isotopes to Rapidly Assess Changes in Bone Mineral Balance Using a Bed Rest Model to Induce Bone Loss

    Science.gov (United States)

    Morgan, J. L. L.; Skulan, J. L.; Gordon, G. E.; Smith, Scott M.; Romaniello, S. J.; Anbar, A. D.

    2012-01-01

    Metabolic bone diseases like osteoporosis result from the disruption of normal bone mineral balance (BMB) resulting in bone loss. During spaceflight astronauts lose substantial bone. Bed rest provides an analog to simulate some of the effects of spaceflight; including bone and calcium loss and provides the opportunity to evaluate new methods to monitor BMB in healthy individuals undergoing environmentally induced-bone loss. Previous research showed that natural variations in the Ca isotope ratio occur because bone formation depletes soft tissue of light Ca isotopes while bone resorption releases that isotopically light Ca back into soft tissue (Skulan et al, 2007). Using a bed rest model, we demonstrate that the Ca isotope ratio of urine shifts in a direction consistent with bone loss after just 7 days of bed rest, long before detectable changes in bone mineral density (BMD) occur. The Ca isotope variations tracks changes observed in urinary N-teleopeptide, a bone resorption biomarker. Bone specific alkaline phosphatase, a bone formation biomarker, is unchanged. The established relationship between Ca isotopes and BMB can be used to quantitatively translate the changes in the Ca isotope ratio to changes in BMD using a simple mathematical model. This model predicts that subjects lost 0.25 0.07% ( SD) of their bone mass from day 7 to day 30 of bed rest. Given the rapid signal observed using Ca isotope measurements and the potential to quantitatively assess bone loss; this technique is well suited to study the short-term dynamics of bone metabolism.

  10. The Cepheid mass discrepancy and pulsation-driven mass loss

    NARCIS (Netherlands)

    Neilson, H.R.; Cantiello, M.; Langer, N.

    2011-01-01

    Context. A longstanding challenge for understanding classical Cepheids is the Cepheid mass discrepancy, where theoretical mass estimates using stellar evolution and stellar pulsation calculations have been found to differ by approximately 10−20%. Aims. We study the role of pulsation-driven mass loss

  11. Biglycan deficiency interferes with ovariectomy-induced bone loss

    DEFF Research Database (Denmark)

    Nielsen, Karina L; Allen, Matthew R; Bloomfield, Susan A

    2003-01-01

    were killed 4 weeks after surgery. Bone mass and bone turnover were analyzed by peripheral quantitative computed tomography (pQCT), biochemical markers, and histomorphometry. RESULTS AND CONCLUSIONS: In contrast to the male mice, there were only few effects of bgn deficiency on bone metabolism...... to biglycan deficiency. INTRODUCTION: Biglycan (bgn) is a small extracellular matrix proteoglycan enriched in skeletal tissues, and biglycan-deficient male mice have decreased trabecular bone mass and bone strength. The purpose of this study was to investigate the bone phenotype of the biglycan...

  12. GLP-1 Receptor Agonist Treatment Increases Bone Formation and Prevents Bone Loss in Weight-Reduced Obese Women.

    Science.gov (United States)

    Iepsen, Eva W; Lundgren, Julie R; Hartmann, Bolette; Pedersen, Oluf; Hansen, Torben; Jørgensen, Niklas R; Jensen, Jens-Erik B; Holst, Jens J; Madsbad, Sten; Torekov, Signe S

    2015-08-01

    Recent studies indicate that glucagon-like peptide (GLP)-1 regulates bone turnover, but the effects of GLP-1 receptor agonists (GLP-1 RAs) on bone in obese weight-reduced individuals are unknown. To investigate the role of GLP-1 RAs on bone formation and weight loss-induced bone mass reduction. Randomized control study. Outpatient research hospital clinic. Thirty-seven healthy obese women with body mass index of 34 ± 0.5 kg/m(2) and age 46 ± 2 years. After a low-calorie-diet-induced 12% weight loss, participants were randomized to treatment with or without administration of the GLP-1 RA liraglutide (1.2 mg/d) for 52 weeks. In case of weight gain, up to two meals per day could be replaced with a low-calorie-diet product to maintain the weight loss. Total, pelvic, and arm-leg bone mineral content (BMC) and bone markers [C-terminal telopeptide of type 1 collagen (CTX-1) and N-terminal propeptide of type 1 procollagen (P1NP)] were investigated before and after weight loss and after 52-week weight maintenance. Primary endpoints were changes in BMC and bone markers after 52-week weight maintenance with or without GLP-1 RA treatment. Total, pelvic, and arm-leg BMC decreased during weight maintenance in the control group (P GLP-1 RA increased bone formation by 16% and prevented bone loss after weight loss obtained through a low-calorie diet, supporting its role as a safe weight-lowering agent.

  13. Low Bone Mineral Mass Is Associated with Decreased Bone Formation and Diet in Females with Rett Syndrome

    Science.gov (United States)

    Motil, Kathleen J.; Barrish, Judy O.; Neul, Jeffrey L.; Glaze, Daniel G.

    2014-01-01

    Objective To characterize biomarkers of bone turnover and their relation with bone mineral mass in a cross-sectional cohort of females with Rett syndrome (RTT) and to examine the role of dietary, biochemical, hormonal, and inflammatory factors on bone mineral mass and bone biomarkers in this disorder. Methods Total body bone mineral content (BMC) and density (BMD) were determined by dual-energy x-ray absorptiometry. Dietary nutrient intakes were determined from 3-day food records. Biomarkers of bone turnover, bone metabolites, vitamin D metabolites, hormones, and inflammatory markers were measured by standard clinical laboratory methods. Results Serum osteocalcin, bone alkaline phosphatase, and C-telopeptide showed significant inverse relations with age in the RTT cohort. Mean osteocalcin concentrations were significantly lower and mean bone alkaline phosphatase concentrations were significantly higher for individual age groups in the RTT cohort than mean values for their respective age ranges in the reference population. Significant inverse associations were identified between urinary calcium losses, expressed as calcium:creatinine ratios, and total body BMC and BMD z-scores. Dietary protein, calcium, and phosphorus intakes, expressed as a proportion of Dietary Reference Intakes for age and gender, showed significant positive associations with total body BMD z-scores. Conclusion This study suggests decreased bone formation rather than increased bone resorption may explain in part the deficits in bone mineral mass in RTT and that attention to the adequacy of dietary protein, calcium and phosphorus intakes may offer an opportunity to improve bone health in RTT. PMID:25144778

  14. Peak bone mass density among residents of Metro Manila

    International Nuclear Information System (INIS)

    Lim-Abrahan, M.A.B.; Guanzon, M.L.V.V.; Balderas, J.A.J.; Villaruel, C.M.; Santos, F.

    1996-01-01

    To determine the peak bone mass density among residents of Metro Manila using dual x-ray absorptiometry (DEXA).The design used is cross-sectional study. The study include 23 females and 22 males, with 3 to 4 subjects for each age range of 5. The methods used was bone mass density measurements on the lumbar spine and the femur using dual x-ray absorptiometry (DPXI lunar) were taken. The values were also age-matched and matched with that of a young adult based on programmed Caucasian norm provided by Lunar Co. The values were then scattered against age for each sex. Ten (10) cc of blood was also extracted from the patients, with 5 cc of blood separated for future studies. Patients were also interviewed as to their lifestyle, diet, use of contraceptive pill or hormonal replacement treatment, using a Filipino version of the revised questionnaire on the WHO Study on osteoporosis. The mean bone mass density at the L21.4 level for females was 1.12±0.11 g/cm 2 and 0,91±0.11 g/cm 2 at the femur. The highest BMD in both the lumbar spine femoral neck measurements among females was achieved between the ages 30-35 years of age with the lowest BMD occurring between 15-20 yrs. old and incidentally in 2 subjects with ages between 40-44. There seems to be little bone loss among beyond the age 35, unlike in the females. Bone mass density among a sample Metro Manila residents was determined using DEXA and the measurements on the lumbar spine and femoral neck. These were age-matched with that of young adult based on Caucasian norm provided by the Lunar Co. Peak bone mass density in the L2L4 level among the females is reached between the ages 30-35 years old, after which there is progressive bone loss with values in the 45-50 years old approximating the values in the 15-19 years old age range. A similar pattern is seen in the measurements taken at the femoral neck. Among males, the peak BMD is reached during the 30-35 years old, but there seems to be no rapid decline or rapid bone

  15. Finite element analysis of bone loss around failing implants

    NARCIS (Netherlands)

    Wolff, J.E.H.; Narra, N.; Antalainen, A.K.; Valasek, J.; Kaiser, J.; Sandor, G.K.; Marcian, P.

    2014-01-01

    Dental implants induce diverse forces on their surrounding bone. However, when excessive unphysiological forces are applied, resorption of the neighbouring bone may occur. The aim of this study was to assess possible causes of bone loss around failing dental implants using finite element analysis. A

  16. Novel Radiomitigator for Radiation-Induced Bone Loss

    Science.gov (United States)

    Schreurs, A-S; Shirazi-fard, Y.; Terada, M.; Alwood, J. S.; Steczina, S.; Medina, C.; Tahimic, C. G. T.; Globus, R. K.

    2016-01-01

    Radiation-induced bone loss can occur with radiotherapy patients, accidental radiation exposure and during long-term spaceflight. Bone loss due to radiation is due to an early increase in oxidative stress, inflammation and bone resorption, resulting in an imbalance in bone remodeling. Furthermore, exposure to high-Linear Energy Transfer (LET) radiation will impair the bone forming progenitors and reduce bone formation. Radiation can be classified as high-LET or low-LET based on the amount of energy released. Dried Plum (DP) diet prevents bone loss in mice exposed to total body irradiation with both low-LET and high-LET radiation. DP prevents the early radiation-induced bone resorption, but furthermore, we show that DP protects the bone forming osteoblast progenitors from high-LET radiation. These results provide insight that DP re-balances the bone remodeling by preventing resorption and protecting the bone formation capacity. This data is important considering that most of the current osteoporosis treatments only block the bone resorption but do not protect bone formation. In addition, DP seems to act on both the oxidative stress and inflammation pathways. Finally, we have preliminary data showing the potential of DP to be radio-protective at a systemic effect and could possible protect other tissues at risk of total body-irradiation such as skin, brain and heart.

  17. Increasing mass loss from Greenland's Mittivakkat Gletscher

    DEFF Research Database (Denmark)

    Hasholt, Bent; Mernild, S.H.; Knudsen, N.T.

    2011-01-01

    Warming in the Arctic during the past several decades has caused glaciers to thin and retreat, and recent mass loss from the Greenland Ice Sheet is well documented. Local glaciers peripheral to the ice sheet are also retreating, but few mass-balance observations are available to quantify that ret......Warming in the Arctic during the past several decades has caused glaciers to thin and retreat, and recent mass loss from the Greenland Ice Sheet is well documented. Local glaciers peripheral to the ice sheet are also retreating, but few mass-balance observations are available to quantify...... balance and glacier front fluctuations. We attribute this mass loss primarily to record high mean summer (June–August) temperatures in combination with lower-than-average winter precipitation. Also, we use the 15-yr mass-balance record to estimate present-day and equilibrium accumulation-area ratios...... for the MG. We show that the glacier is significantly out of balance and will likely lose at least 70% of its current area and 80% of its volume even in the absence of further climate changes. Temperature records from coastal stations in Southeast Greenland suggest that recent MG mass losses are not merely...

  18. Antibody-based inhibition of circulating DLK1 protects from estrogen deficiency-induced bone loss in mice

    DEFF Research Database (Denmark)

    Figeac, Florence; Andersen, Ditte C.; Nipper Nielsen, Casper A.

    2018-01-01

    /TV) and inhibition of bone resorption. No significant changes were observed in total fat mass or in the number of bone marrow adipocytes. These results support the potential use of anti-DLK1 antibody therapy as a novel intervention to protect from E deficiency associated bone loss....... deficiency-associated bone loss in mice. Thus, we generated mouse monoclonal anti-mouse DLK1 antibodies (MAb DLK1) that enabled us to reduce and also quantitate the levels of bioavailable serum DLK1 in vivo. Ovariectomized (ovx) mice were injected intraperitoneally twice weekly with MAb DLK1 over a period...... of one month. DEXA-, microCT scanning, and bone histomorphometric analyses were performed. Compared to controls, MAb DLK1 treated ovx mice were protected against ovx-induced bone loss, as revealed by significantly increased total bone mass (BMD) due to increased trabecular bone volume fraction (BV...

  19. Glucocorticoid: A potential role in microgravity-induced bone loss

    Science.gov (United States)

    Yang, Jiancheng; Yang, Zhouqi; Li, Wenbin; Xue, Yanru; Xu, Huiyun; Li, Jingbao; Shang, Peng

    2017-11-01

    Exposure of animals and humans to conditions of microgravity, including actual spaceflight and simulated microgravity, results in numerous negative alterations to bone structure and mechanical properties. Although there are abundant researches on bone loss in microgravity, the explicit mechanism is not completely understood. At present, it is widely accepted that the absence of mechanical stimulus plays a predominant role in bone homeostasis disorders in conditions of weightlessness. However, aside from mechanical unloading, nonmechanical factors such as various hormones, cytokines, dietary nutrition, etc. are important as well in microgravity induced bone loss. The stress-induced increase in endogenous glucocorticoid (GC) levels is inevitable in microgravity environments. Moreover, it is well known that GCs have a detrimental effect to bone health at excess concentrations. Therefore, GC plays a potential role in microgravity-induced bone loss. This review summarizeds several studies and their prospective solutions to this hypothesis.

  20. Effect of hormone replacement therapy on the bone mass and urinary excretion of pyridinium cross-links

    OpenAIRE

    Pardini,Dolores Perovano; Sabino,Anibal Tagliaferri; Meneses,Ana Maria; Kasamatsu,Teresa; Vieira,José Gilberto Henriques

    2000-01-01

    CONTEXT: The menopause accelerates bone loss and is associated with an increased bone turnover. Bone formation may be evaluated by several biochemical markers. However, the establishment of an accurate marker for bone resorption has been more difficult to achieve. OBJECTIVE: To study the effect of hormone replacement therapy (HRT) on bone mass and on the markers of bone resorption: urinary excretion of pyridinoline and deoxypyridinoline. DESIGN: Cohort correlational study. SETTING: Academic...

  1. Effect of trabecular bone loss on cortical strain rate during impact in an in vitro model of avian femur

    Directory of Open Access Journals (Sweden)

    Gefen Amit

    2006-07-01

    Full Text Available Abstract Background Osteoporotic hip fractures occur due to loss of cortical and trabecular bone mass and consequent degradation in whole bone strength. The direct cause of most fractures is a fall, and hence, characterizing the mechanical behavior of a whole osteopenic bone under impact is important. However, very little is known about the mechanical interactions between cortical and trabecular bone during impact, and it is specifically unclear to what extent epiphyseal trabecular bone contributes to impact resistance of whole bones. We hypothesized that trabecular bone serves as a structural support to the cortex during impact, and hence, loss of a critical mass of trabecular bone reduces internal constraining of the cortex, and, thereby, decreases the impact tolerance of the whole bone. Methods To test this hypothesis, we conducted cortical strain rate measurements in adult chicken's proximal femora subjected to a Charpy impact test, after removing different trabecular bone core masses to simulate different osteopenic severities. Results We found that removal of core trabecular bone decreased by ~10-fold the cortical strain rate at the side opposite to impact (p Conclusion We conclude that in our in vitro avian model, loss of over 10% of core trabecular bone substantially altered the deformation response of whole bone to impact, which supports the above hypothesis and indicates that integrity of trabecular bone is critical for resisting impact loads.

  2. Differential roles of MAPK kinases MKK3 and MKK6 in osteoclastogenesis and bone loss.

    Directory of Open Access Journals (Sweden)

    David L Boyle

    Full Text Available Bone mass is maintained by osteoclasts that resorb bone and osteoblasts that promote matrix deposition and mineralization. Bone homeostasis is altered in chronic inflammation as well as in post-menopausal loss of estrogen, which favors osteoclast activity that leads to osteoporosis. The MAPK p38α is a key regulator of bone loss and p38 inhibitors preserve bone mass by inhibiting osteoclastogenesis. p38 function is regulated by two upstream MAPK kinases, namely MKK3 and MKK6. The goal of this study was to assess the effect of MKK3- or MKK6-deficiency on osteoclastogenesis in vitro and on bone loss in ovariectomy-induced osteoporosis in mice. We demonstrated that MKK3 but not MKK6, regulates osteoclast differentiation from bone marrow cells in vitro. Expression of NFATc1, a master transcription factor in osteoclastogenesis, is decreased in cells lacking MKK3 but not MKK6. Expression of osteoclast-specific genes Cathepsin K, osteoclast-associated receptor and MMP9, was inhibited in MKK3-/- cells. The effect of MKK-deficiency on ovariectomy-induced bone loss was then evaluated in female WT, MKK3-/- and MKK6-/- mice by micro-CT analysis. Bone loss was partially inhibited in MKK3-/- as well as MKK6-/- mice, despite normal osteoclastogenesis in MKK6-/- cells. This correlated with the lower osteoclast numbers in the MKK-deficient ovariectomized mice. These studies suggest that MKK3 and MKK6 differentially regulate bone loss due to estrogen withdrawal. MKK3 directly mediates osteoclastogenesis while MKK6 likely contributes to pro-inflammatory cytokine production that promotes osteoclast formation.

  3. The influence of smoking on bone loss and response to nasal estradiol

    DEFF Research Database (Denmark)

    Bjarnason, N.H.; Nielsen, T.F.; Jørgensen, Henrik Løvendahl

    2009-01-01

    Objective To investigate the influence of smoking on bone during therapy with nasally administrated estradiol in sequential combination with oral progesterone in early postmenopausal women. In addition, to observe the consequences of smoking on bone in untreated women. Methods Post-hoc explorator...... estradiol to increase bone mass in early postmenopausal women. In addition, smoking may increase spontaneous bone loss in untreated women Udgivelsesdato: 2009......Objective To investigate the influence of smoking on bone during therapy with nasally administrated estradiol in sequential combination with oral progesterone in early postmenopausal women. In addition, to observe the consequences of smoking on bone in untreated women. Methods Post-hoc exploratory...... analyses of data from 270 postmenopausal women randomized to 2 years' therapy with daily nasal administration of 17-estradiol or placebo sequentially combined with oral micronized progesterone in the active groups or placebo in the placebo group. Results During treatment with nasal estradiol, the bone...

  4. Role of Oxidative Damage in Radiation-Induced Bone Loss

    Science.gov (United States)

    Schreurs, Ann-Sofie; Alwood, Joshua S.; Limoli, Charles L.; Globus, Ruth K.

    2014-01-01

    During prolonged spaceflight, astronauts are exposed to both microgravity and space radiation, and are at risk for increased skeletal fragility due to bone loss. Evidence from rodent experiments demonstrates that both microgravity and ionizing radiation can cause bone loss due to increased bone-resorbing osteoclasts and decreased bone-forming osteoblasts, although the underlying molecular mechanisms for these changes are not fully understood. We hypothesized that excess reactive oxidative species (ROS), produced by conditions that simulate spaceflight, alter the tight balance between osteoclast and osteoblast activities, leading to accelerated skeletal remodeling and culminating in bone loss. To test this, we used the MCAT mouse model; these transgenic mice over-express the human catalase gene targeted to mitochondria, the major organelle contributing free radicals. Catalase is an anti-oxidant that converts reactive species, hydrogen peroxide into water and oxygen. This animal model was selected as it displays extended lifespan, reduced cardiovascular disease and reduced central nervous system radio-sensitivity, consistent with elevated anti-oxidant activity conferred by the transgene. We reasoned that mice overexpressing catalase in mitochondria of osteoblast and osteoclast lineage cells would be protected from the bone loss caused by simulated spaceflight. Over-expression of human catalase localized to mitochondria caused various skeletal phenotypic changes compared to WT mice; this includes greater bone length, decreased cortical bone area and moment of inertia, and indications of altered microarchitecture. These findings indicate mitochondrial ROS are important for normal bone-remodeling and skeletal integrity. Catalase over-expression did not fully protect skeletal tissue from structural decrements caused by simulated spaceflight; however there was significant protection in terms of cellular oxidative damage (MDA levels) to the skeletal tissue. Furthermore, we

  5. Receptor tyrosine kinase inhibition causes simultaneous bone loss and excess bone formation within growing bone in rats

    International Nuclear Information System (INIS)

    Nurmio, Mirja; Joki, Henna; Kallio, Jenny; Maeaettae, Jorma A.; Vaeaenaenen, H. Kalervo; Toppari, Jorma; Jahnukainen, Kirsi; Laitala-Leinonen, Tiina

    2011-01-01

    During postnatal skeletal growth, adaptation to mechanical loading leads to cellular activities at the growth plate. It has recently become evident that bone forming and bone resorbing cells are affected by the receptor tyrosine kinase (RTK) inhibitor imatinib mesylate (STI571, Gleevec (registered) ). Imatinib targets PDGF, ABL-related gene, c-Abl, c-Kit and c-Fms receptors, many of which have multiple functions in the bone microenvironment. We therefore studied the effects of imatinib in growing bone. Young rats were exposed to imatinib (150 mg/kg on postnatal days 5-7, or 100 mg/kg on postnatal days 5-13), and the effects of RTK inhibition on bone physiology were studied after 8 and 70 days (3-day treatment), or after 14 days (9-day treatment). X-ray imaging, computer tomography, histomorphometry, RNA analysis and immunohistochemistry were used to evaluate bone modeling and remodeling in vivo. Imatinib treatment eliminated osteoclasts from the metaphyseal osteochondral junction at 8 and 14 days. This led to a resorption arrest at the growth plate, but also increased bone apposition by osteoblasts, thus resulting in local osteopetrosis at the osteochondral junction. The impaired bone remodelation observed on day 8 remained significant until adulthood. Within the same bone, increased osteoclast activity, leading to bone loss, was observed at distal bone trabeculae on days 8 and 14. Peripheral quantitative computer tomography (pQCT) and micro-CT analysis confirmed that, at the osteochondral junction, imatinib shifted the balance from bone resorption towards bone formation, thereby altering bone modeling. At distal trabecular bone, in turn, the balance was turned towards bone resorption, leading to bone loss. - Research highlights: → 3-Day imatinib treatment. → Causes growth plate anomalies in young rats. → Causes biomechanical changes and significant bone loss at distal trabecular bone. → Results in loss of osteoclasts at osteochondral junction.

  6. Bone mass in schizophrenia and normal populations across different decades of life

    Directory of Open Access Journals (Sweden)

    Chueh Ching-Mo

    2009-01-01

    Full Text Available Abstract Background Chronic schizophrenic patients have been reported as having higher osteoporosis prevalence. Survey the bone mass among schizophrenic patients and compare with that of the local community population and reported data of the same country to figure out the distribution of bone mass among schizophrenic patients. Methods 965 schizophrenic patients aged 20 years and over in Yuli Veterans Hospital and 405 members aged 20 and over of the community living in the same town as the institute received bone mass examination by a heel qualitative ultrasound (QUS device. Bone mass distribution was stratified to analyzed and compared with community population. Results Schizophrenic patients have lower bone mass while they are young. But aging effect on bone mass cannot be seen. Accelerated bone mass loss during menopausal transition was not observed in the female schizophrenic patients as in the subjects of the community female population. Conclusion Schizophrenic patients have lower bone mass than community population since they are young. Further study to investigate the pathophysiological process is necessary to delay or avoid the lower bone mass in schizophrenia patients.

  7. Primary Hyperparathyroidism: The Influence of Bone Marrow Adipose Tissue on Bone Loss and of Osteocalcin on Insulin Resistance

    Directory of Open Access Journals (Sweden)

    Maira L. Mendonça

    Full Text Available OBJECTIVES: Bone marrow adipose tissue has been associated with low bone mineral density. However, no data exist regarding marrow adipose tissue in primary hyperparathyroidism, a disorder associated with bone loss in conditions of high bone turnover. The objective of the present study was to investigate the relationship between marrow adipose tissue, bone mass and parathyroid hormone. The influence of osteocalcin on the homeostasis model assessment of insulin resistance was also evaluated. METHODS: This was a cross-sectional study conducted at a university hospital, involving 18 patients with primary hyperparathyroidism (PHPT and 21 controls (CG. Bone mass was assessed by dual-energy x-ray absorptiometry and marrow adipose tissue was assessed by 1H magnetic resonance spectroscopy. The biochemical evaluation included the determination of parathyroid hormone, osteocalcin, glucose and insulin levels. RESULTS: A negative association was found between the bone mass at the 1/3 radius and parathyroid hormone levels (r = -0.69; p<0.01. Marrow adipose tissue was not significantly increased in patients (CG = 32.8±11.2% vs PHPT = 38.6±12%. The serum levels of osteocalcin were higher in patients (CG = 8.6±3.6 ng/mL vs PHPT = 36.5±38.4 ng/mL; p<0.005, but no associations were observed between osteocalcin and insulin or between insulin and both marrow adipose tissue and bone mass. CONCLUSION: These results suggest that the increment of adipogenesis in the bone marrow microenvironment under conditions of high bone turnover due to primary hyperparathyroidism is limited. Despite the increased serum levels of osteocalcin due to primary hyperparathyroidism, these patients tend to have impaired insulin sensitivity.

  8. Determinants of bone mass and bone geometry in adolescent and young adult women

    NARCIS (Netherlands)

    Kardinaal, A.F.M.; Hoorneman, G.; Väänänen, K.; Charles, P.; Ando, S.; Maggiolini, M.; Charzewska, J.; Rotily, M.; Deloraine, A.; Heikkinen, J.; Juvin, R.; Schaafsma, G.

    2000-01-01

    Bone mass and bone geometry are considered to have independent effects on bone strength. The purpose of this study was to obtain data on bone mass and geometry in young female populations and how they are influenced by body size and lifestyle factors. In a cross-sectional, observational study in six

  9. Mass-loss rates of hot stars

    Czech Academy of Sciences Publication Activity Database

    Kubát, Jiří; Šurlan, Brankica

    -, č. 92 (2013), s. 137-146 ISSN 0373-3742. [Future science with metre-class telescopes. Beograd, 18.09.2012-21.09.2012] R&D Projects: GA ČR GA205/08/0003 Institutional support: RVO:67985815 Keywords : stars winds * outflows stars * mass-loss stars Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics

  10. Urinary calcium, sodium, and bone mass of young females.

    Science.gov (United States)

    Matkovic, V; Ilich, J Z; Andon, M B; Hsieh, L C; Tzagournis, M A; Lagger, B J; Goel, P K

    1995-08-01

    Calcium is an important determinant of peak bone mass in young adults because of its influence on skeletal development during growth. Attainment of maximum peak bone mass requires optimal positive balance between calcium intake and obligatory losses of calcium, primarily in urine and feces. Urinary excretion is an important determinant of calcium retention in the body. Accordingly, the purpose of this study was to evaluate the influence of various nutrients on urinary calcium excretion, and to assess their impact on bone mass of young females, aged 8-13 y, during early puberty. The study was conducted in 381 healthy white females in pubertal stage 2. From each participant we collected basic anthropometric measurements, a 3-d food record, blood, a 24-h urine sample, and bone mass measurements of the total body and forearm by dual X-ray absorptiometry. Urinary sodium was found to be one of the most important determinants of urinary calcium excretion: [urinary calcium (mmol/d) = 0.01154 x urinary sodium (mmol/d) + 0.823], whereas calcium intake had relatively little impact: [urinary calcium (mmol/d) = 0.02252 x calcium intake (mmol/d) + 1.5261]. Urinary calcium was much higher at a calcium intake of approximately 37.5 mmol/d (1500 mg/d), supporting the notion that calcium is a threshold nutrient. Calcium intake had a significant positive influence on the bone mineral content and density of the whole body and radius shaft whereas urinary calcium had a negative influence, presumably by reducing calcium accretion into the skeleton.(ABSTRACT TRUNCATED AT 250 WORDS)

  11. Bisphosphonates as a Countermeasure to Space Flight Induced Bone Loss

    Science.gov (United States)

    LeBlanc, Adrian; Matsumoto, Toshio; Jones, Jeffrey A.; Shapiro, Jay; Lang, Thomas F.; Smith, Scott M.; Shackelford, Linda C.; Sibonga, Jean; Evans, Harlan; Spector, Elisabeth; hide

    2009-01-01

    Bisphosphonates as a Countermeasure to Space Flight Induced Bone Loss (Bisphosphonates) will determine whether antiresorptive agents, in conjunction with the routine inflight exercise program, will protect ISS crewmembers from the regional decreases in bone mineral density documented on previous ISS missions.

  12. Biglycan deficiency interferes with ovariectomy-induced bone loss

    DEFF Research Database (Denmark)

    Nielsen, Karina L; Allen, Matthew R; Bloomfield, Susan A

    2003-01-01

    Biglycan is a matrix proteoglycan with a possible role in bone turnover. In a 4-week study with sham-operated or OVX biglycan-deficient or wildtype mice, we show that biglycan-deficient mice are resistant to OVX-induced trabecular bone loss and that there is a gender difference in the response...

  13. Bone loss following knee arthroplasty: potential treatment options.

    Science.gov (United States)

    Vasso, Michele; Beaufils, Philippe; Cerciello, Simone; Schiavone Panni, Alfredo

    2014-04-01

    The management of bone loss is a crucial aspect of the revision knee arthroplasty. Bone loss can hinder the correct positioning and alignment of the prosthetic components, and can prevent the achievement of a stable bone-implant interface. There is still controversy regarding the optimal management of knee periprosthetic bone loss, especially in large defects for which structural grafts, metal or tantalum augments, tantalum cones, porous metaphyseal sleeves, and special prostheses have been advocated. The aim of this review was to analyze all possible causes of bone loss and the most advanced strategies for managing bony deficiency within the knee joint reconstruction. Most significant and recent papers about the management of bone defects during revision knee arthroplasty were carefully analyzed and reviewed to report the most common causes of bone loss and the most effective strategies to manage them. Modular metal and tantalum augmentation showed to provide more stable and durable knee revisions compared to allografts, limited by complications such as graft failure, fracture and resorption. Moreover, modular augmentation may considerably shorten operative times with a potential decrease of complications, above all infection which has been frequently associated to the use of allografts. Modular augmentation may significantly reduce the need for allografting, whose complications appear to limit the long-term success of knee revisions.

  14. Salvianolic acid B prevents bone loss in prednisone-treated rats through stimulation of osteogenesis and bone marrow angiogenesis.

    Directory of Open Access Journals (Sweden)

    Liao Cui

    Full Text Available Glucocorticoid (GC induced osteoporosis (GIO is caused by the long-term use of GC for treatment of autoimmune and inflammatory diseases. The GC related disruption of bone marrow microcirculation and increased adipogenesis contribute to GIO development. However, neither currently available anti-osteoporosis agent is completely addressed to microcirculation and bone marrow adipogenesis. Salvianolic acid B (Sal B is a polyphenolic compound from a Chinese herbal medicine, Salvia miltiorrhiza Bunge. The aim of this study was to determine the effects of Sal B on osteoblast bone formation, angiogenesis and adipogenesis-associated GIO by performing marrow adipogenesis and microcirculation dilation and bone histomorphometry analyses. (1 In vivo study: Bone loss in GC treated rats was confirmed by significantly decreased BMD, bone strength, cancellous bone mass and architecture, osteoblast distribution, bone formation, marrow microvessel density and diameter along with down-regulation of marrow BMPs expression and increased adipogenesis. Daily treatment with Sal B (40 mg/kg/d for 12 weeks in GC male rats prevented GC-induced cancellous bone loss and increased adipogenesis while increasing cancellous bone formation rate with improved local microcirculation by capillary dilation. Treatment with Sal B at a higher dose (80 mg/kg/d not only prevented GC-induced osteopenia, but also increased cancellous bone mass and thickness, associated with increase of marrow BMPs expression, inhibited adipogenesis and further increased microvessel diameters. (2 In vitro study: In concentration from 10(-6 mol/L to 10(-7 mol/L, Sal B stimulated bone marrow stromal cell (MSC differentiation to osteoblast and increased osteoblast activities, decreased GC associated adipogenic differentiation by down-regulation of PPARγ mRNA expression, increased Runx2 mRNA expression without osteoblast inducement, and, furthermore, Sal B decreased Dickkopf-1 and increased β-catenin m

  15. Improvement of Lumbar Bone Mass after Infliximab Therapy in Crohn’s Disease Patients

    Directory of Open Access Journals (Sweden)

    Marina Mauro

    2007-01-01

    Full Text Available BACKGROUND: Patients with Crohn’s disease (CD have a high risk of developing osteoporosis, but the mechanisms underlying bone mass loss are unclear. Elevated proinflammatory cytokines, such as tumour necrosis factor-alpha (TNFα, have been implicated in the pathogenesis of bone resorption.

  16. CCR2 elimination in mice results in larger and stronger tibial bones but bone loss is not attenuated following ovariectomy or muscle denervation.

    Science.gov (United States)

    Mader, Tara L; Novotny, Susan A; Lin, Angela S; Guldberg, Robert E; Lowe, Dawn A; Warren, Gordon L

    2014-11-01

    Bone loss due to age and disuse contributes to osteoporosis and increases fracture risk. It has been hypothesized that such bone loss can be attenuated by modulation of the C-C chemokine receptor 2 (CCR2) and/or its ligands. The objectives of this study were to examine the effects of genetic elimination of CCR2 on cortical and trabecular bones in the mouse tibia and how bone loss was impacted following disuse and estrogen loss. Female CCR2 knockout (CCR2(-/-)) and wildtype mice underwent ovariectomy (OVX) or denervation of musculature adjacent to the tibia (DEN) to induce bone loss. Cortical and trabecular structural properties as well as mechanical properties (i.e., strength) of tibial bones were measured. Compared to wildtype mice, CCR2(-/-) mice had tibiae that were up to 9% larger and stronger; these differences could be explained mainly by the 17% greater body mass (P bone loss per se. These findings indicate that while CCR2(-/-) mice do have larger and stronger bones than do wildtype mice, there is minimal evidence that CCR2 elimination provides protection against bone loss during disuse and estrogen loss.

  17. Peak bone mineral density, lean body mass and fractures

    NARCIS (Netherlands)

    Boot, Annemieke M.; de Ridder, Maria A. J.; van der Sluis, Inge M.; van Slobbe, Ingrid; Krenning, Eric P.; Keizer-Schrama, Sabine M. P. F. de Muinck

    Background: During childhood and adolescence, bone mass and lean body mass (LBM) increase till a plateau is reached. In this longitudinal and cross-sectional study, the age of reaching the plateau was evaluated for lumbar spine and total body bone mass measurements and lean body mass. The

  18. Mass Loss Rates of Fasting Polar Bears.

    Science.gov (United States)

    Pilfold, Nicholas W; Hedman, Daryll; Stirling, Ian; Derocher, Andrew E; Lunn, Nicholas J; Richardson, Evan

    2016-01-01

    Polar bears (Ursus maritimus) have adapted to an annual cyclic regime of feeding and fasting, which is extreme in seasonal sea ice regions of the Arctic. As a consequence of climate change, sea ice breakup has become earlier and the duration of the open-water period through which polar bears must rely on fat reserves has increased. To date, there is limited empirical data with which to evaluate the potential energetic capacity of polar bears to withstand longer fasts. We measured the incoming and outgoing mass of inactive polar bears (n = 142) that were temporarily detained by Manitoba Conservation and Water Stewardship during the open-water period near the town of Churchill, Manitoba, Canada, in 2009-2014. Polar bears were given access to water but not food and held for a median length of 17 d. Median mass loss rates were 1.0 kg/d, while median mass-specific loss rates were 0.5%/d, similar to other species with high adiposity and prolonged fasting capacities. Mass loss by unfed captive adult males was identical to that lost by free-ranging individuals, suggesting that terrestrial feeding contributes little to offset mass loss. The inferred metabolic rate was comparable to a basal mammalian rate, suggesting that while on land, polar bears can maintain a depressed metabolic rate to conserve energy. Finally, we estimated time to starvation for subadults and adult males for the on-land period. Results suggest that at 180 d of fasting, 56%-63% of subadults and 18%-24% of adult males in this study would die of starvation. Results corroborate previous assessments on the limits of polar bear capacity to withstand lengthening ice-free seasons and emphasize the greater sensitivity of subadults to changes in sea ice phenology.

  19. Building better bone: The weaving of biologic and engineering strategies for managing bone loss.

    Science.gov (United States)

    Schwartz, Andrew M; Schenker, Mara L; Ahn, Jaimo; Willett, Nick J

    2017-09-01

    Segmental bone loss remains a challenging clinical problem for orthopaedic trauma surgeons. In addition to the missing bone itself, the local tissues (soft tissue, vascular) are often highly traumatized as well, resulting in a less than ideal environment for bone regeneration. As a result, attempts at limb salvage become a highly expensive endeavor, often requiring multiple operations and necessitating the use of every available strategy (autograft, allograft, bone graft substitution, Masquelet, bone transport, etc.) to achieve bony union. A cost-sensitive, functionally appropriate, and volumetrically adequate engineered substitute would be practice-changing for orthopaedic trauma surgeons and these patients with difficult clinical problems. In tissue engineering and bone regeneration fields, numerous research efforts continue to make progress toward new therapeutic interventions for segmental bone loss, including novel biomaterial development as well as cell-based strategies. Despite an ever-evolving literature base of these new therapeutic and engineered options, there remains a disconnect with the clinical practice, with very few translating into clinical use. A symposium entitled "Building better bone: The weaving of biologic and engineering strategies for managing bone loss," was presented at the 2016 Orthopaedic Research Society Conference to further explore this engineering-clinical disconnect, by surveying basic, translational, and clinical researchers along with orthopaedic surgeons and proposing ideas for pushing the bar forward in the field of segmental bone loss. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1855-1864, 2017. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  20. Bone loss in rheumatoid arthritis. Influence of disease activity, duration of the disease, functional capacity, and corticosteroid treatment

    DEFF Research Database (Denmark)

    Hansen, M; Florescu, A; Stoltenberg, M

    1996-01-01

    Axial and appendicular bone mass were studied in 95 patients with rheumatoid arthritis. The aims were to quantify bone mineral density (BMD) and to evaluate the importance of disease activity, duration of disease, functional capacity, and corticosteroid treatment for bone loss in patients...... activity at the time of investigation. By contrast, BMDARM was decreased in patients with active disease. BMD in any of the three measured locations was not directly correlated to duration of the disease. However, the bone mass in the appendicular skeleton was already decreased within the first two years...... to clinical improvement, which may counteract the expected negative effect of these drugs on bone in rheumatoid arthritis....

  1. The role of stromal cells in inflammatory bone loss.

    Science.gov (United States)

    Wehmeyer, C; Pap, T; Buckley, C D; Naylor, A J

    2017-07-01

    Rheumatoid arthritis (RA) is an autoimmune disease characterized by chronic inflammation, local and systemic bone loss and a lack of compensatory bone repair. Fibroblast-like synoviocytes (FLS) are the most abundant cells of the stroma and a key population in autoimmune diseases such as RA. An increasing body of evidence suggests that these cells play not only an important role in chronic inflammation and synovial hyperplasia, but also impact bone remodelling. Under inflammatory conditions FLS release inflammatory cytokines, regulate bone destruction and formation and communicate with immune cells to control bone homeostasis. Other stromal cells, such as osteoblasts and terminally differentiated osteoblasts, termed osteocytes, are also involved in the regulation of bone homeostasis and are dysregulated during inflammation. This review highlights our current understanding of how stromal cells influence the balance between bone formation and bone destruction. Increasing our understanding of these processes is critical to enable the development of novel therapeutic strategies with which to treat bone loss in RA. © 2017 British Society for Immunology.

  2. Temporal bone imaging in osteogenesis imperfecta patients with hearing loss

    NARCIS (Netherlands)

    Swinnen, F.K.R.; Casselman, J.W.; Leenheer, E.M. De; Cremers, C.W.R.J.; Dhooge, I.J.

    2013-01-01

    OBJECTIVES/HYPOTHESIS: Osteogenesis imperfecta (OI) is an autosomal-dominant connective-tissue disorder, predominantly characterized by bone fragility. Conductive hearing loss develops in half of the OI patients and often progresses to mixed loss. Findings of computed tomography (CT) and magnetic

  3. Bone loss after bariatric surgery: causes, consequences, and management.

    Science.gov (United States)

    Stein, Emily M; Silverberg, Shonni J

    2014-02-01

    Bariatric surgery is an effective and increasingly common treatment for severe obesity and its many comorbidities. The side-effects of bariatric surgery can include detrimental effects on bone and mineral metabolism. Bone disease in patients who have had bariatric surgery is affected by preoperative abnormalities in bone and mineral metabolism related to severe obesity. Changes that arise after bariatric surgery are specific to procedure type: the most pronounced abnormalities in calciotropic hormones and bone loss are noted after procedures that result in the most malabsorption. The most consistent site for bone loss after all bariatric procedures is at the hip. There are limitations of dual-energy x-ray absorptiometry technology in this population, including artefact introduced by adipose tissue itself. Bone loss after bariatric surgery is probably multifactorial. Proposed mechanisms include skeletal unloading, abnormalities in calciotropic hormones, and changes in gut hormones. Few data for fracture risk in the bariatric population are available, and this is a crucial area for additional research. Treatment should be geared toward correction of nutritional deficiencies and study of bone mineral density in high-risk patients. We explore the skeletal response to bariatric surgery, potential mechanisms for changes, and strategies for management. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. Serum markers of bone metabolism show bone loss in hibernating bears

    Science.gov (United States)

    Donahue, S.W.; Vaughan, M.R.; Demers, L.M.; Donahue, H.J.

    2003-01-01

    Disuse osteopenia was studied in hibernating black bears (Ursus americanus) using serum markers of bone metabolism. Blood samples were collected from male and female, wild black bears during winter denning and active summer periods. Radioimmunoassays were done to determine serum concentrations of cortisol, the carboxy-terminal cross-linked telopeptide, and the carboxy-terminal propeptide of Type I procollagen, which are markers of hone resorption and formation, respectively. The bone resorption marker was significantly higher during winter hibernation than it was in the active summer months, but the bone formation marker was unchanged, suggesting an imbalance in bone remodeling and a net bone loss during disuse. Serum cortisol was significantly correlated with the bone resorption marker, but not with the bone formation marker. The bone formation marker was four- to fivefold higher in an adolescent and a 17-year-old bear early in the remobilization period compared with the later summer months. These findings raise the possibility that hibernating black bears may minimize bone loss during disuse by maintaining osteoblastic function and have a more efficient compensatory mechanism for recovering immobilization-induced bone loss than that of humans or other animals.

  5. Pulsation, Mass Loss and the Upper Mass Limit

    Science.gov (United States)

    Klapp, J.; Corona-Galindo, M. G.

    1990-11-01

    RESUMEN. La existencia de estrellas con masas en exceso de 100 M0 ha sido cuestionada por mucho tiempo. Lfmites superiores para la masa de 100 M0 han sido obtenidos de teorfas de pulsaci6n y formaci6n estelar. En este trabajo nosotros primero investigamos la estabilidad radial de estrellas masivas utilizando la aproximaci6n clasica cuasiadiabatica de Ledoux, la aproximaci6n cuasiadiabatica de Castor y un calculo completamente no-adiabatico. Hemos encontrado que los tres metodos de calculo dan resultados similares siempre y cuando una pequefia regi6n de las capas externas de la estrella sea despreciada para la aproximaci6n clasica. La masa crftica para estabilidad de estrellas masivas ha sido encontrada en acuerdo a trabajos anteriores. Explicamos Ia discrepancia entre este y trabajos anteriores por uno de los autores. Discunmos calculos no-lineales y perdida de masa con respecto a) lfmite superior de masa. The existence of stars with masses in excess of 100 M0 has been questioned for a very long time. Upper mass limits of 100 Me have been obtained from pulsation and star formation theories. In this work we first investigate the radial stability of massive stars using the classical Ledoux's quasiadiabatic approximation. the Castor quasiadiabatic approximation and a fully nonadiabatic calculation. We have found that the three methods of calculation give similar results provided that a small region in outer layers of the star be neglected for the classical approximation. The critical mass for stability of massive stars is found to be in agreement with previous work. We explain the reason for the discrepancy between this and previous work by one of the authors. We discuss non-linear calculations and mass loss with regard to the upper mass limit. Key words: STARS-MASS FUNCTION - STARS-MASS LOSS - STARS-PULSATION

  6. Osteoporosis: Peak Bone Mass in Women

    Science.gov (United States)

    ... has been linked to low bone density in adolescents and is associated with other unhealthy behaviors, such ... Bone Health for Lupus Patients Bone Health and Anorexia Nervosa Partner Resources Screening Tests and Immunizations Guidelines for ...

  7. Regional cortical and trabecular bone loss after spinal cord injury.

    Science.gov (United States)

    Dudley-Javoroski, Shauna; Shields, Richard K

    2012-01-01

    Spinal cord injury (SCI) triggers rapid loss of trabecular bone mineral density (BMD) in bone epiphyses and a loss of cortical cross-sectional area (CSA) in bone diaphyses, increasing fracture risk for people with SCI. The purpose of this study was to measure trabecular BMD and cortical CSA loss at several previously unexamined lower-limb sites (4% fibula, 12% femur, 86% tibia, cortical) in individuals with SCI. Using peripheral quantitative computed tomography, we scanned 13 participants with SCI longitudinally and 16 on one occasion; 21 participants without SCI served as controls. In the first year post-SCI, 15% to 35% of BMD was lost at the distal femur, proximal tibia, and distal fibula. Bone loss at the distal fibula accelerated between 1 and 2 years post-SCI. BMD at these sites reached a steady state value of ~50% of the non-SCI value 4 years post-SCI. At the tibia diaphysis, cortical CSA decline was slower, eventually reaching 65% of the non-SCI value. Because of the extensive loss of bone observed at these sites, careful consideration needs to be given to the dose of musculoskeletal stress delivered during rehabilitation interventions like standing, muscle electrical stimulation, and aggressive stretching of spastic muscles.

  8. Bone Loss During Spaceflight: Available Models and Counter-Measures

    Science.gov (United States)

    Morris, Jonathan; Bach, David; Geller, David

    2015-01-01

    There is ongoing concern for human health during spaceflights. Of particular interest is the uncoupling of bone remodeling and its resultant effect on calcium metabolism and bone loss. The calculated average loss of bone mineral density (BMD) is approximately 1-1.5% per month of spaceflight. The effect of decreased BMD on associated fractures in astronauts is not known. Currently on the International Space Station (ISS), bone loss is managed through dietary supplements and modifications and resistance exercise regimen. As the duration of space flights increases, a review of the current methods available for the prevention of bone loss is warranted. The goal of this project is to review and summarize recent studies that have focused on maintaining BMD during exposure to microgravity. Interventions were divided into physical (Table 1), nutritional (Table 2), or pharmacologic (Table 3) categories. Physical modalities included resistance exercise, low level vibration, and low intensity pulsed ultrasound. Nutritional interventions included altering protein, salt, and fat intake; and vitamin D supplementation. Pharmacologic interventions included the use of bisphosphonates and beta blockers. Studies reported outcomes based on bone density determined by DXA bone scan, micro-architecture of histology and microCT, and serum and urine markers of bone turnover. The ground analog models utilized to approximate osseous physiology in microgravity included human patients previously paralyzed or subjects confined to bedrest. Ground analog animal models include paralysis, immobilization and ovariectomies. As a result of the extensive research performed there is a multi-modality approach available for the management of BMD during spaceflight that includes resistance training, nutrition and dietary supplements. However, there is a paucity of literature describing a formalized tiered protocol to guide investigators through the progression from animal models to human patient ground

  9. FSH and TSH in the Regulation of Bone Mass: The Pituitary/Immune/Bone Axis

    Directory of Open Access Journals (Sweden)

    Graziana Colaianni

    2013-01-01

    Full Text Available Recent evidences have highlighted that the pituitary hormones have profound effects on bone, so that the pituitary-bone axis is now becoming an important issue in the skeletal biology. Here, we discuss the topical evidence about the dysfunction of the pituitary-bone axis that leads to osteoporotic bone loss. We will explore the context of FSH and TSH hormones arguing their direct or indirect role in bone loss. In addition, we will focus on the knowledge that both FSH and TSH have influence on proinflammatory and proosteoclastogenic cytokine expression, such as TNFα and IL-1, underlining the correlation of pituitary-bone axis to the immune system.

  10. Osteopenia in anorexia nervosa: specific mechanisms of bone loss.

    Science.gov (United States)

    Lennkh, C; de Zwaan, M; Bailer, U; Strnad, A; Nagy, C; el-Giamal, N; Wiesnagrotzki, S; Vytiska, E; Huber, J; Kasper, S

    1999-01-01

    Osteopenia is a well recognized medical complication of anorexia nervosa (AN). The mechanism of bone loss is not fully understood and there is uncertainty about its management. New markers of bone turnover have been developed. C-terminal type 1 propeptide (PICP) is a measure of bone formation and urinary pyridinolines such as deoxypyridinoline (DPYRX) and serum carboxyterminal crosslinked telopeptide (ICTP) are markers of bone resorption. The aim of this study was to examine these bone markers in patients with AN. Twenty female patients with AN and 12 healthy controls were included in the study. Bone mineral density (BMD) of AN patients was measured by dual energy X-ray absorptiometry (DEXA). Lumbar bone density was significantly reduced in the AN group compared to standardised values of thirty year old adults (t-score 83.2%, S.D. 12.1). Femoral neck bone density showed an even greater reduction (t-score 79.4%, S.D. 13.5). We found a significant negative correlation between femoral BMD and the duration of the illness. Femoral BMD correlated significantly with minimal body weight (r(16) = 0.504, p = 0.033). The markers of bone resorption were significantly higher in the patients with AN compared to the values of the control group (ICTP t(30) = -2.15, p = 0.04, DPYRX t(25) = -2.26, p = 0.033), whereas the markers of bone formation did not differ significantly between the groups. AN appears to be a low turn over state associated with increased bone resorption without concomitant bone formation. This pattern differs from osteopenia in menopausal women and should, therefore, lead to the development of specific therapeutic strategies in AN associated osteopenia. Hormone replacement therapy as well as calcium and vitamine D-supplementation are so far discussed controversially. Long-term treatment studies are warranted.

  11. Genistein supplementation increases bone turnover but does not prevent alcohol-induced bone loss in male mice

    Science.gov (United States)

    Chronic alcohol consumption results in bone loss through increased bone resorption and decreased bone formation. These effects can be reversed by estradiol (E2) supplementation. Soy diets are suggested to have protective effects on bone loss in men and women, as a result of the presence of soy prote...

  12. Bone loss rate in adrenal incidentalomas: a longitudinal study.

    Science.gov (United States)

    Chiodini, I; Torlontano, M; Carnevale, V; Guglielmi, G; Cammisa, M; Trischitta, V; Scillitani, A

    2001-11-01

    Although by definition patients with adrenal incidentalomas (AI) do not have evident clinical syndromes, they may frequently suffer from subclinical hypercortisolism (SH). This is of some importance because of evidence that SH may lead to clinical complications, including bone loss. Thus, the understanding of bone involvement due to SH may be extremely important in the management of AI. Unfortunately, the available data on bone mineral density (BMD) in AI patients come from cross-sectional studies, which, to further complicate our understanding, are also conflicting, probably due to a different selection of patients and/or the variability in cortisol secretion (CS) often described in AI. To gain further insight about this topic, we performed a longitudinal study evaluating the rate of spinal and femoral bone loss levels in 24 females with AI. AI subjects were subdivided in two groups on the basis of the median of urinary cortisol secretion (UFC): group I (n = 12; UFC, 140.4 nmol/24 h). Spinal BMD was measured by both single energy quantitative computed tomography (L1-L4) and dual energy x-ray absorptiometry (DXA; L2-L4), and femoral BMD was determined by DXA. Bone loss rate was expressed as the change in z-score per yr. The spinal bone loss rate was higher (P < 0.005) in group II than in group I when measured by both quantitative computed tomography (-0.19 +/- 0.14 vs. 0.00 +/- 0.15) and DXA (-0.19 +/- 0.17 vs. 0.00 +/- 0.11). Moreover, CS and spinal bone loss rate were significantly correlated when patients were considered together. In conclusion, our data show that 1) AI patients with higher CS have increased lumbar trabecular bone loss rate than those with lower CS; and 2) the degree of spinal bone loss rate is related to the degree of CS. Thus, lumbar spine (LS) BMD has to be evaluated for well balanced decision-making on the treatment of choice for AI female patients.

  13. Synergistic effects of green tea polyphenols and alphacalcidol on chronic inflammation-induced bone loss in female rats

    Science.gov (United States)

    Summary: Studies suggest that green tea polyphenols (GTP) or alphacalcidol is promising agent for preventing bone loss. Findings that GTP supplementation in the drinking water plus alphacalcidol administration resulted in increased bone mass via a decrease of oxidative stress and inflammation sugges...

  14. Does platform switching really prevent crestal bone loss around implants?

    Directory of Open Access Journals (Sweden)

    Yoshiyuki Hagiwara

    2010-08-01

    Full Text Available To maintain long-term implant stability, it is important to minimize bone loss around the implant. Several clinical studies have shown a mean marginal bone loss around dental implants of 1.5–2 mm in the first year after prosthetic restoration. Currently, concepts to prevent bone loss around dental implants have been reported as the platform switching (PLS. This technique use of prosthetic abutments with reduced width in relation to the implant platform diameter seems to have the greatest potential to limit the crestal resorption. However, there are only a few reports on the mechanism of action or the extent of bone loss prevention, and as such, it is difficult to say that the effect of PLS has been thoroughly examined. Excluding case reports, articles on PLS can be broadly categorized into: (1 radiographic evaluation of crestal bone level in humans, (2 histological and histomorphometrical analysis in animals, or (3 finite element analysis. This review revealed a shortage of published data for above three categories related PLS. Researchers have attempted to explain the mechanism of action of PLS; however, it is necessary to conduct further studies, including histological studies using animals, to clarify the mechanism fully.

  15. The Role of Mechanical Stimulation in Recovery of Bone Loss-High versus Low Magnitude and Frequency of Force.

    Science.gov (United States)

    Nagaraja, Mamta Patel; Jo, Hanjoong

    2014-04-02

    Musculoskeletal pathologies associated with decreased bone mass, including osteoporosis and disuse-induced bone loss, affect millions of Americans annually. Microgravity-induced bone loss presents a similar concern for astronauts during space missions. Many pharmaceutical treatments have slowed osteoporosis, and recent data shows promise for countermeasures for bone loss observed in astronauts. Additionally, high magnitude and low frequency impact such as running has been recognized to increase bone and muscle mass under normal but not microgravity conditions. However, a low magnitude and high frequency (LMHF) mechanical load experienced in activities such as postural control, has also been shown to be anabolic to bone. While several clinical trials have demonstrated that LMHF mechanical loading normalizes bone loss in vivo, the target tissues and cells of the mechanical load and underlying mechanisms mediating the responses are unknown. In this review, we provide an overview of bone adaptation under a variety of loading profiles and the potential for a low magnitude loading as a way to counteract bone loss as experienced by astronauts.

  16. Targeting cellular senescence prevents age-related bone loss in mice.

    Science.gov (United States)

    Farr, Joshua N; Xu, Ming; Weivoda, Megan M; Monroe, David G; Fraser, Daniel G; Onken, Jennifer L; Negley, Brittany A; Sfeir, Jad G; Ogrodnik, Mikolaj B; Hachfeld, Christine M; LeBrasseur, Nathan K; Drake, Matthew T; Pignolo, Robert J; Pirtskhalava, Tamar; Tchkonia, Tamara; Oursler, Merry Jo; Kirkland, James L; Khosla, Sundeep

    2017-09-01

    Aging is associated with increased cellular senescence, which is hypothesized to drive the eventual development of multiple comorbidities. Here we investigate a role for senescent cells in age-related bone loss through multiple approaches. In particular, we used either genetic (i.e., the INK-ATTAC 'suicide' transgene encoding an inducible caspase 8 expressed specifically in senescent cells) or pharmacological (i.e., 'senolytic' compounds) means to eliminate senescent cells. We also inhibited the production of the proinflammatory secretome of senescent cells using a JAK inhibitor (JAKi). In aged (20- to 22-month-old) mice with established bone loss, activation of the INK-ATTAC caspase 8 in senescent cells or treatment with senolytics or the JAKi for 2-4 months resulted in higher bone mass and strength and better bone microarchitecture than in vehicle-treated mice. The beneficial effects of targeting senescent cells were due to lower bone resorption with either maintained (trabecular) or higher (cortical) bone formation as compared to vehicle-treated mice. In vitro studies demonstrated that senescent-cell conditioned medium impaired osteoblast mineralization and enhanced osteoclast-progenitor survival, leading to increased osteoclastogenesis. Collectively, these data establish a causal role for senescent cells in bone loss with aging, and demonstrate that targeting these cells has both anti-resorptive and anabolic effects on bone. Given that eliminating senescent cells and/or inhibiting their proinflammatory secretome also improves cardiovascular function, enhances insulin sensitivity, and reduces frailty, targeting this fundamental mechanism to prevent age-related bone loss suggests a novel treatment strategy not only for osteoporosis, but also for multiple age-related comorbidities.

  17. Blocking antibody to the beta-subunit of FSH prevents bone loss by inhibiting bone resorption and stimulating bone synthesis

    Science.gov (United States)

    Low estrogen levels undoubtedly underlie menopausal bone thinning. However, rapid and profuse bone loss begins three years prior to the last menstrual period, when serum estrogen is relatively normal. We have shown that the pituitary hormone FSH, the levels of which are high during the late peri-men...

  18. Rapid cortical bone loss in patients with chronic kidney disease.

    Science.gov (United States)

    Nickolas, Thomas L; Stein, Emily M; Dworakowski, Elzbieta; Nishiyama, Kyle K; Komandah-Kosseh, Mafo; Zhang, Chiyuan A; McMahon, Donald J; Liu, Xiaowei S; Boutroy, Stephanie; Cremers, Serge; Shane, Elizabeth

    2013-08-01

    Chronic kidney disease (CKD) patients may have high rates of bone loss and fractures, but microarchitectural and biochemical mechanisms of bone loss in CKD patients have not been fully described. In this longitudinal study of 53 patients with CKD Stages 2 to 5D, we used dual-energy X-ray absorptiometry (DXA), high-resolution peripheral quantitative computed tomography (HRpQCT), and biochemical markers of bone metabolism to elucidate effects of CKD on the skeleton. Median follow-up was 1.5 years (range 0.9 to 4.3 years); bone changes were annualized and compared with baseline. By DXA, there were significant declines in areal bone mineral density (BMD) of the total hip and ultradistal radius: -1.3% (95% confidence interval [CI] -2.1 to -0.6) and -2.4% (95% CI -4.0 to -0.9), respectively. By HRpQCT at the distal radius, there were significant declines in cortical area, density, and thickness and increases in porosity: -2.9% (95% CI -3.7 to -2.2), -1.3% (95% CI -1.6 to -0.6), -2.8% (95% CI -3.6 to -1.9), and +4.2% (95% CI 2.0 to 6.4), respectively. Radius trabecular area increased significantly: +0.4% (95% CI 0.2 to 0.6), without significant changes in trabecular density or microarchitecture. Elevated time-averaged levels of parathyroid hormone (PTH) and bone turnover markers predicted cortical deterioration. Higher levels of serum 25-hydroxyvitamin D predicted decreases in trabecular network heterogeneity. These data suggest that significant cortical loss occurs with CKD, which is mediated by hyperparathyroidism and elevated turnover. Future investigations are required to determine whether these cortical losses can be attenuated by treatments that reduce PTH levels and remodeling rates. Copyright © 2013 American Society for Bone and Mineral Research.

  19. Risk Factors for Osteoporosis and Oral Bone Loss in Postmenopausal Women

    National Research Council Canada - National Science Library

    Wactawski-Wende, Jean

    1998-01-01

    ... and oral bone loss, periodontal disease and tooth loss. We hypothesize that reduction in bone density leading to osteoporosis, plays a significant role in increasing susceptibility to destructive periodontitis and tooth loss...

  20. Risk Factors for Osteoporosis and Oral Bone Loss in Postmenopausal Women

    National Research Council Canada - National Science Library

    Wactawski-Wende, Jean

    2001-01-01

    ... and oral bone loss, periodontal disease and tooth loss. We hypothesize that reduction in bone density leading to osteoporosis, plays a significant role in increasing susceptibility to destructive periodontitis and tooth loss...

  1. Risk Factors for Osteoporosis and Oral Bone Loss in Postmenopausal Women

    National Research Council Canada - National Science Library

    Wacawski-Wende, Jean

    1997-01-01

    ... and oral bone loss, periodontal disease and tooth loss. We hypothesize that reduction in bone density leading to osteoporosis, plays a significant role in increasing susceptibility to destructive periodontitis and tooth loss...

  2. Risk Factors for Osteoporosis and Oral Bone Loss in Postmenopausal Women

    National Research Council Canada - National Science Library

    Wactawski-Wende, Jean

    1999-01-01

    ... and oral bone loss, periodontal disease and tooth loss. We hypothesize that reduction in bone density leading to osteoporosis, plays a significant role in increasing susceptibility to destructive periodontitis and tooth loss...

  3. Risk Factors for Osteoporosis and Oral Bone Loss in Postmenopausal Women

    National Research Council Canada - National Science Library

    Wactawski-Wende, Jean

    2000-01-01

    ... and oral bone loss, periodontal disease and tooth loss. We hypothesize that reduction in bone density leading to osteoporosis, plays a significant role in increasing susceptibility to destructive periodontitis and tooth loss...

  4. Staged subtalar fusion for severe calcaneus fractures with bone loss.

    Science.gov (United States)

    Williams, Chad G; Coffey, Michael J; Shorten, Peter; Lyions, James D; Laughlin, Richard T

    2013-01-01

    With high energy fractures to the calcaneus there is the potential for significant bone loss. The loss of bone can make it difficult to fully regain calcaneal alignment. In addition these fractures are often associated with significant soft tissue injury. These two factors make it difficult to address this injury in a single stage, and can have significant complications. To address these issues our initial goal in treatment has been restoration of calcaneal alignment and stabilization of the surrounding soft tissue, followed by delayed/staged subtalar arthrodesis. Patients with calcaneus fractures treated by a single surgeon from 2002 to 2012 were reviewed. Injuries which were found to have medial extrusion of the posterior facet and bone loss, and subsequently underwent a staged protocol involving early provisional fixation and late subtalar fusion were included. We treated 6 calcaneus fractures with bone loss. All patients were treated with staged subtalar fusion after initial irrigation and debridement and provisional fixation. No soft-tissue complications were noted after the fusion procedure in any of the six cases. Fusion occurred in all six patients at an average of 20.6 weeks (range, 13-23 weeks). All patients were able to ambulate and wear a regular shoe by one year following the initial injury. It is important in the high energy calcaneus fracture to assess for both soft tissue integrity and bone loss. A thorough debridement of both the soft tissues and any devitalized bone should be performed as well as provisional fixation which attempts to restore near normal calcaneal anatomy. Definitive fusion should not be performed until the soft tissues have fully recovered.

  5. Suppression Effect of Astaxanthin on Osteoclast Formation In Vitro and Bone Loss In Vivo

    Directory of Open Access Journals (Sweden)

    Yun-Ho Hwang

    2018-03-01

    Full Text Available Osteoporosis is characterized by a reduction of the bone mineral density (BMD and microarchitectural deterioration of the bone, which lead to bone fragility and susceptibility to fracture. Astaxanthin (AST has a variety of biological activities, such as a protective effect against asthma or neuroinflammation, antioxidant effect, and decrease of the osteoclast number in the right mandibles in the periodontitis model. Although treatment with AST is known to have an effect on inflammation, no studies on the effect of AST exposure on bone loss have been performed. Thus, in the present study, we examined the antiosteoporotic effect of AST on bone mass in ovariectomized (OVX mice and its possible mechanism of action. The administration of AST (5, 10 mg/kg for 6 weeks suppressed the enhancement of serum calcium, inorganic phosphorus, alkaline phosphatase, total cholesterol, and tartrate-resistant acid phosphatase (TRAP activity. The bone mineral density (BMD and bone microarchitecture of the trabecular bone in the tibia and femur were recovered by AST exposure. Moreover, in the in vitro experiment, we demonstrated that AST inhibits osteoclast formation through the expression of the nuclear factor of activated T cells (NFAT c1, dendritic cell-specific transmembrane protein (DC-STAMP, TRAP, and cathepsin K without any cytotoxic effects on bone marrow-derived macrophages (BMMs. Therefore, we suggest that AST may have therapeutic potential for the treatment of postmenopausal osteoporosis.

  6. Cepharanthine Prevents Estrogen Deficiency-Induced Bone Loss by Inhibiting Bone Resorption

    Directory of Open Access Journals (Sweden)

    Chen-he Zhou

    2018-03-01

    Full Text Available Osteoporosis is a common health problem worldwide caused by an imbalance of bone formation vs. bone resorption. However, current therapeutic approaches aimed at enhancing bone formation or suppressing bone resorption still have some limitations. In this study, we demonstrated for the first time that cepharanthine (CEP, derived from Stephania cepharantha Hayata exerted a protective effect on estrogen deficiency-induced bone loss. This protective effect was confirmed to be achieved through inhibition of bone resorption in vivo, rather than through enhancement of bone formation in vivo. Furthermore, the in vitro study revealed that CEP attenuated receptor activator of nuclear factor κB ligand (RANKL-induced osteoclast formation, and suppressed bone resorption by impairing the c-Jun N-terminal kinase (JNK and phosphatidylinositol 3-kinase (PI3K-AKT signaling pathways. The inhibitory effect of CEP could be partly reversed by treatment with anisomycin (a JNK and p38 agonist and/or SC79 (an AKT agonist in vitro. Our results thus indicated that CEP could prevent estrogen deficiency-induced bone loss by inhibiting osteoclastogenesis. Hence, CEP might be a novel therapeutic agent for anti-osteoporosis therapy.

  7. Soy Isoflavones and Osteoporotic Bone Loss: A Review with an Emphasis on Modulation of Bone Remodeling

    Science.gov (United States)

    Zheng, Xi; Lee, Sun-Kyeong

    2016-01-01

    Abstract Osteoporosis is an age-related disorder that affects both women and men, although estrogen deficiency induced by menopause accelerates bone loss in older women. As the demographic shifts to a more aged population, a growing number of men and women will be afflicted with osteoporosis. Since the current drug therapies available have multiple side effects, including increased risk of developing certain types of cancer or complications, a search for potential nonpharmacologic alternative therapies for osteoporosis is of prime interest. Soy isoflavones (SI) have demonstrated potential bone-specific effects in a number of studies. This article provides a systematic review of studies on osteoporotic bone loss in relation to SI intake from diet or supplements to comprehensively explain how SI affect the modulation of bone remodeling. Evidence from epidemiologic studies supports that dietary SI attenuate menopause-induced osteoporotic bone loss by decreasing bone resorption and stimulating bone formation. Other studies have also illustrated that bone site-specific trophic and synergistic effects combined with exercise intervention might contribute to improve the bioavailability of SI or strengthen the bone-specific effects. To date, however, the effects of dietary SI on osteoporotic bone loss remain inconclusive, and study results vary from study to study. The current review will discuss the potential factors that result in the conflicting outcomes of these studies, including dosages, intervention materials, study duration, race, and genetic differences. Further well-designed studies are needed to fully understand the underlying mechanism and evaluate the effects of SI on osteoporosis in humans. PMID:26670451

  8. Bone transport and compression-distraction in the treatment of bone loss of the lower limbs.

    Science.gov (United States)

    Lavini, Franco; Dall'Oca, Carlo; Bartolozzi, Pietro

    2010-11-01

    A clinical series of 17 adult patients operated due to significant by bone loss of the long bones of the lower extremity (3 femurs and 11 tibias), is presented. Their management consisted of 6 bone transports (6 tibias) and 11 compression distraction procedures (3 femurs and 8 tibiae) using monolateral external fixators. Bone loss ranged from 3.9 cm to 14.7 cm. Mean healing time was 301 days with a mean healing index of 45.6 days for cm of lengthening achieved. The clinical and radiological results were excellent in 9, good in 6 and fair in 2 patients according to the utilised criteria of assessment. Consolidation was achieved in all but one patient who developed an aseptic stiff non-union. Two patients developed residual limb-length discrepancy less than 1.5 cm, three tibias ended up with less than 5° of valgus deviation. In two cases the half-pins were re-inserted due to early loosening. In two cases reoperation was needed for late bending of the callus after fixator removal. Three cases of bone transport and 1 case of compression distraction needed bone grafting at the docking site. Bone transport and compression-distraction are effective methods for treating bone loss in the lower extremity. It is suggested that the compression-distraction technique is preferable, since this is associated with a lower incidence of complications than bone transport procedures. The deciding factor, however, is the actual extent of the bone loss. Copyright © 2010 Elsevier Ltd. All rights reserved.

  9. Glycosylation of immunoglobulin G determines osteoclast differentiation and bone loss.

    Science.gov (United States)

    Harre, Ulrike; Lang, Stefanie C; Pfeifle, René; Rombouts, Yoann; Frühbeißer, Sabine; Amara, Khaled; Bang, Holger; Lux, Anja; Koeleman, Carolien A; Baum, Wolfgang; Dietel, Katharina; Gröhn, Franziska; Malmström, Vivianne; Klareskog, Lars; Krönke, Gerhard; Kocijan, Roland; Nimmerjahn, Falk; Toes, René E M; Herrmann, Martin; Scherer, Hans Ulrich; Schett, Georg

    2015-03-31

    Immunglobulin G (IgG) sialylation represents a key checkpoint that determines the engagement of pro- or anti-inflammatory Fcγ receptors (FcγR) and the direction of the immune response. Whether IgG sialylation influences osteoclast differentiation and subsequently bone architecture has not been determined yet, but may represent an important link between immune activation and bone loss. Here we demonstrate that desialylated, but not sialylated, immune complexes enhance osteoclastogenesis in vitro and in vivo. Furthermore, we find that the Fc sialylation state of random IgG and specific IgG autoantibodies determines bone architecture in patients with rheumatoid arthritis. In accordance with these findings, mice treated with the sialic acid precursor N-acetylmannosamine (ManNAc), which results in increased IgG sialylation, are less susceptible to inflammatory bone loss. Taken together, our findings provide a novel mechanism by which immune responses influence the human skeleton and an innovative treatment approach to inhibit immune-mediated bone loss.

  10. Amlexanox Suppresses Osteoclastogenesis and Prevents Ovariectomy-Induced Bone Loss.

    Science.gov (United States)

    Zhang, Yong; Guan, Hanfeng; Li, Jing; Fang, Zhong; Chen, Wenjian; Li, Feng

    2015-09-04

    The activity of protein kinases IKK-ε and TANK-binding kinase 1 (TBK1) has been shown to be associated with inflammatory diseases. As an inhibitor of IKK-ε and TBK1, amlexanox is an anti-inflammatory, anti-allergic, immunomodulator and used for treatment of ulcer, allergic rhinitis and asthma in clinic. We hypothesized that amlexanox may be used for treatment of osteoclast-related diseases which frequently associated with a low grade of systemic inflammation. In this study, we investigated the effects of amlexanox on RANKL-induced osteoclastogenesis in vitro and ovariectomy-mediated bone loss in vivo. In primary bone marrow derived macrophages (BMMs), amlexanox inhibited osteoclast formation and bone resorption. At the molecular level, amlexanox suppressed RANKL-induced activation of nuclear factor-κB (NF-κB), mitogen-activated protein kinase (MAPKs), c-Fos and NFATc1. Amlexanox decreased the expression of osteoclast-specific genes, including TRAP, MMP9, Cathepsin K and NFATc1. Moreover, amlexanox enhanced osteoblast differentiation of BMSCs. In ovariectomized (OVX) mouse model, amlexanox prevented OVX-induced bone loss by suppressing osteoclast activity. Taken together, our results demonstrate that amlexanox suppresses osteoclastogenesis and prevents OVX-induced bone loss. Therefore, amlexanox may be considered as a new therapeutic candidate for osteoclast-related diseases, such as osteoporosis and rheumatoid arthritis.

  11. Exact and Asymptotic Scaling Solutions for Fragmentation with Mass Loss

    OpenAIRE

    Cai, M.; Edwards, Boyd F.; Han, H.

    1991-01-01

    Exact and asymptotic solutions to a linear rate equation for fragmentation with mass loss are presented. Solutions for spatially discrete random bond annihilation illustrate the mutual exclusiveness of the fragmentation and recession terms in the rate equation. Exact solutions for deterministic equal fragment recession show that continuous mass loss between fragmentation events can be approximated by discrete mass loss during fragmentation events when this mass loss is small. Evidence ...

  12. Correlation of interdental and interradicular bone loss in patients ...

    African Journals Online (AJOL)

    2012-01-19

    Jan 19, 2012 ... Key words: Alveolar bone loss, chronic periodontitis, dental, furcation defect, radiography. Date of Acceptance: 19-Jan- ... cemento-enamel junction (CEJ) and the alveolar crest (AC) or the bottom of the bony ..... prognosis of periodontal healing of infrabony defects: Two different definitions of defect depth.

  13. Mandibular atrophy and metabolic bone loss. Endocrinology, radiology and histomorphometry

    NARCIS (Netherlands)

    Habets, L. L.; Bras, J.; Borgmeyer-Hoelen, A. M.

    1988-01-01

    In 11 edentulous patients with a severe atrophy of the mandible and submitted for ridge augmentation, endocrinological, radiological and histomorphometrical studies were carried out. The results showed that metabolic bone loss, histologically in nearly all patients characterized as a disturbance in

  14. Interleukin-1 is essential for systemic inflammatory bone loss.

    NARCIS (Netherlands)

    Polzer, K.; Joosten, L.A.B.; Gasser, J.; Distler, J.H.; Ruiz, G.; Baum, W.; Redlich, K.; Bobacz, K.; Smolen, J.S.; Berg, W. van den; Schett, G.; Zwerina, J.

    2010-01-01

    OBJECTIVES: Chronic inflammation is a major risk factor for systemic bone loss leading to osteoporotic fracture and substantial morbidity and mortality. Inflammatory cytokines, particularly tumour necrosis factor (TNF) and interleukin-1 (IL1), are thought to play a key role in the pathogenesis of

  15. Patterns of bone loss around teeth restored with endodontic posts

    NARCIS (Netherlands)

    Katsamakis, S.; Timmerman, M.; van der Velden, U.; de Cleen, M.; van der Weijden, F.

    2009-01-01

    Objectives: This retrospective study described the pattern of bone loss around teeth with endodontic posts in periodontitis patients, and compared it with contra-lateral teeth without posts. Material and Methods: From full-mouth radiographic surveys of 146 periodontitis patients (35 years), 194

  16. Correlation of interdental and interradicular bone loss in patients ...

    African Journals Online (AJOL)

    Objective: The aim of this study was to investigate the correlation between interdental and interradicular bone loss and clinical parameters in patients with chronic periodontitis. Materials and Methods: One hundred-twenty intraoral periapical radiographs of first molars were obtained from patients with chronic periodontitis ...

  17. Bone growth stimulators. New tools for treating bone loss and mending fractures.

    Science.gov (United States)

    Whitfield, James F; Morley, Paul; Willick, Gordon E

    2002-01-01

    In the new millennium, humans will be traveling to Mars and eventually beyond with skeletons that respond to microgravity by self-destructing. Meanwhile in Earth's aging populations growing numbers of men and many more women are suffering from crippling bone loss. During the first decade after menopause all women suffer an accelerating loss of bone, which in some of them is severe enough to result in "spontaneous" crushing of vertebrae and fracturing of hips by ordinary body movements. This is osteoporosis, which all too often requires prolonged and expensive care, the physical and mental stress of which may even kill the patient. Osteoporosis in postmenopausal women is caused by the loss of estrogen. The slower development of osteoporosis in aging men is also due at least in part to a loss of the estrogen made in ever smaller amounts in bone cells from the declining level of circulating testosterone and is needed for bone maintenance as it is in women. The loss of estrogen increases the generation, longevity, and activity of bone-resorbing osteoclasts. The destructive osteoclast surge can be blocked by estrogens and selective estrogen receptor modulators (SERMs) as well as antiosteoclast agents such as bisphosphonates and calcitonin. But these agents stimulate only a limited amount of bone growth as the unaffected osteoblasts fill in the holes that were dug by the now suppressed osteoclasts. They do not stimulate osteoblasts to make bone--they are antiresorptives not bone anabolic agents. (However, certain estrogen analogs and bisphosphates may stimulate bone growth to some extent by lengthening osteoblast working lives.) To grow new bone and restore bone strength lost in space and on Earth we must know what controls bone growth and destruction. Here we discuss the newest bone controllers and how they might operate. These include leptin from adipocytes and osteoblasts and the statins that are widely used to reduce blood cholesterol and cardiovascular damage. But

  18. Risk Factors for Osteoporosis and Oral Bone Loss in Postmenopausal Women

    National Research Council Canada - National Science Library

    Wactawski-Wende, Jean

    2000-01-01

    The overall purpose of this study is to determine the relationship between skeletal and oral bone density, identify factors influencing bone loss, and determine the relationship between osteoporosis...

  19. Risk Factors for Osteoporosis and Oral Bone Loss in Postmenopausal Women

    National Research Council Canada - National Science Library

    Wactawski-Wende, Jean

    1999-01-01

    The overall purpose of this study is to determine the relationship between skeletal and oral bone density, identify factors influencing bone loss, and determine the relationship between osteoporosis...

  20. Risk Factors for Osteoporosis and Oral Bone Loss in Postmenopausal Women

    National Research Council Canada - National Science Library

    Wactawski-Wende, Jean

    2001-01-01

    The overall purpose of this study is to determine the relationship between skeletal and oral bone density, identify factors influencing bone loss, and determine the relationship between osteoporosis...

  1. Risk Factors for Osteoporosis and Oral Bone Loss in Postmenopausal Women

    National Research Council Canada - National Science Library

    Wactawski-Wende, Jean

    1998-01-01

    The overall purpose of this study is to determine the relationship between skeletal and oral bone density, identify factors influencing bone loss, and determine the relationship between osteoporosis...

  2. Risk Factors for Osteoporosis and Oral Bone Loss in Postmenopausal Women

    National Research Council Canada - National Science Library

    Wacawski-Wende, Jean

    1997-01-01

    The overall purpose of this study is to determine the relationship between skeletal and oral bone density, identify factors influencing bone loss, and determine the relationship between osteoporosis...

  3. Loss of bone strength in HLA-B27 transgenic rats is characterized by a high bone turnover and is mainly osteoclast-driven.

    Science.gov (United States)

    Rauner, Martina; Thiele, Sylvia; Fert, Ingrid; Araujo, Luiza M; Layh-Schmitt, Gerlinde; Colbert, Robert A; Hofbauer, Christine; Bernhardt, Ricardo; Bürki, Alexander; Schwiedrzik, Jakob; Zysset, Philippe K; Pietschmann, Peter; Taurog, Joel D; Breban, Maxime; Hofbauer, Lorenz C

    2015-06-01

    Although osteopenia is frequent in spondyloarthritis (SpA), the underlying cellular mechanisms and association with other symptoms are poorly understood. This study aimed to characterize bone loss during disease progression, determine cellular alterations, and assess the contribution of inflammatory bowel disease (IBD) to bone loss in HLA-B27 transgenic rats. Bones of 2-, 6-, and 12-month-old non-transgenic, disease-free HLA-B7 and disease-associated HLA-B27 transgenic rats were examined using peripheral quantitative computed tomography, μCT, and nanoindentation. Cellular characteristics were determined by histomorphometry and ex vivo cultures. The impact of IBD was determined using [21-3 x 283-2]F1 rats, which develop arthritis and spondylitis, but not IBD. HLA-B27 transgenic rats continuously lost bone mass with increasing age and had impaired bone material properties, leading to a 3-fold decrease in bone strength at 12 months of age. Bone turnover was increased in HLA-B27 transgenic rats, as evidenced by a 3-fold increase in bone formation and a 6-fold increase in bone resorption parameters. Enhanced osteoclastic markers were associated with a larger number of precursors in the bone marrow and a stronger osteoclastogenic response to RANKL or TNFα. Further, IBD-free [21-3 x 283-2]F1 rats also displayed decreased total and trabecular bone density. HLA-B27 transgenic rats lose an increasing amount of bone density and strength with progressing age, which is primarily mediated via increased bone remodeling in favor of bone resorption. Moreover, IBD and bone loss seem to be independent features of SpA in HLA-B27 transgenic rats. Copyright © 2015 Elsevier Inc. All rights reserved.

  4. Computational Analysis of Artificial Gravity as a Possible Countermeasure to Spaceflight Induced Bone Loss

    Science.gov (United States)

    Mulugeta, L.; Werner, C. R.; Pennline, J. A.

    2015-01-01

    During exploration class missions, such as to asteroids and Mars, astronauts will be exposed to reduced gravity for extended periods. Data has shown that astronauts lose bone mass at a rate of 1% to 2% a month in microgravity, particularly in lower extremities such as the proximal femur. Exercise countermeasures have not completely eliminated bone loss from long duration spaceflight missions, which leaves astronauts susceptible to early onset osteoporosis and greater risk of fracture. Introduction of the Advanced Resistive Exercise Device and other large exercise devices on the International Space Station (ISS), coupled with improved nutrition, has further minimized bone loss. However, unlike the ISS, exploration vehicles will have very limited volume and power available to accommodate such capabilities. Therefore, novel concepts like artificial gravity systems are being explored as a means to provide sufficient load stimulus to the musculoskeletal system to mitigate bone changes that may lead to early onset osteoporosis and increased risk of fracture. Currently, there is minimal data available to drive further research and development efforts to appropriately explore such options. Computational modeling can be leveraged to gain insight on the level of osteoprotection that may be achieved using artificial gravity produced by a spinning spacecraft or centrifuge. With this in mind, NASA's Digital Astronaut Project (DAP) has developed a bone remodeling model that has been validated for predicting volumetric bone mineral density (vBMD) changes of trabecular and cortical bone both for gravitational unloading condition and the equivalent of 1g daily load stimulus. Using this model, it is possible to simulate vBMD changes in trabecular and cortical bone under different gravity conditions. In this presentation, we will discuss our preliminary findings regarding if and how artificial gravity may be used to mitigate spaceflight induced bone loss.

  5. CYP11A1 expression in bone is associated with aromatase inhibitor-related bone loss.

    Science.gov (United States)

    Rodríguez-Sanz, M; García-Giralt, N; Prieto-Alhambra, D; Servitja, S; Balcells, S; Pecorelli, R; Díez-Pérez, A; Grinberg, D; Tusquets, I; Nogués, X

    2015-08-01

    Aromatase inhibitors (AIs) used as adjuvant therapy in postmenopausal women with hormone receptor-positive breast cancer cause diverse musculoskeletal side effects that include bone loss and its associated fracture. About half of the 391 patients treated with AIs in the Barcelona-Aromatase induced bone loss in early breast cancer cohort suffered a significant bone loss at lumbar spine (LS) and/or femoral neck (FN) after 2 years on AI-treatment. In contrast, up to one-third (19.6% LS, 38.6% FN) showed no decline or even increased bone density. The present study aimed to determine the genetic basis for this variability. SNPs in candidate genes involved in vitamin D and estrogen hormone-response pathways (CYP11A1, CYP17A1, HSD3B2, HSD17B3, CYP19A1, CYP2C19, CYP2C9, ESR1, DHCR7, GC, CYP2R1, CYP27B1, VDR and CYP24A1) were genotyped for association analysis with AI-related bone loss (AIBL). After multiple testing correction, 3 tag-SNPs (rs4077581, s11632698 and rs900798) located in the CYP11A1 gene were significantly associated (Pbone tissue and primary osteoblasts was demonstrated by RT-PCR. Both common isoforms of human cholesterol side-chain cleavage enzyme (encoded by CYP11A1 gene) were detected in osteoblasts by western blot. In conclusion, the genetic association of CYP11A1 gene with AIBL and its expression in bone tissue reveals a potential local function of this enzyme in bone metabolism regulation, offering a new vision of the steroidogenic ability of this tissue and new understanding of AI-induced bone loss. © 2015 Society for Endocrinology.

  6. Bisphosphonate as a Countermeasure to Space Flight-Induced Bone Loss

    Science.gov (United States)

    Spector, Elisabeth; LeBlanc, A.; Sibonga, J.; Matsumoto, T.; Jones, J.; Smith, S. M.; Shackelford, L.; Shapiro, J.; Lang, T.; Evans, H.; hide

    2009-01-01

    The purpose of this research is to determine whether anti-resorptive pharmaceuticals such as bisphosphonates, in conjunction with the routine in-flight exercise program, will protect ISS crewmembers from the regional decreases in bone mineral density and bone strength and the increased renal stone risk documented on previous long-duration space flights [1-3]. Losses averaged 1 to 2 percent per month in such regions as the lumbar spine and hip. Although losses showed significant heterogeneity among individuals and between bones within a given subject, space flight-induced bone loss was a consistent finding. More than 90 percent of astronauts and cosmonauts on long-duration flights (average 171 days) aboard Mir and the ISS, had a minimum 5 percent loss in at least one skeletal site, 40 percent of them had a 10 percent or greater loss in at least one skeletal site, and 22 percent of the Mir cosmonauts experienced a 15 to 20 percent loss in at least one site. These losses occurred even though the crewmembers performed time-consuming in-flight exercise regimens. Moreover, a recent study of 16 ISS astronauts using quantitative computed tomography (QCT) demonstrated trabecular bone losses from the hip averaging 2.3 percent per month [4]. These losses were accompanied by significant losses in hip bone strength that may not be recovered quickly [5]. This rapid loss of bone mass results from a combination of increased and uncoupled remodeling, as demonstrated by increased resorption with little or no change in bone formation markers [6-7]. This elevated remodeling rate likely affects the cortical and trabecular architecture and may lead to irreversible changes. In addition to bone loss, the resulting hypercalciuria increases renal stone risk. Therefore, it is logical to attempt to attenuate this increased remodeling with anti-resorption drugs such as bisphosphonates. Success with alendronate was demonstrated in a bed rest study [8]. This work has been extended to space

  7. DXA measurements in rett syndrome reveal small bones with low bone mass

    DEFF Research Database (Denmark)

    Roende, Gitte; Ravn, Kirstine; Fuglsang, Kathrine

    2011-01-01

    Low bone mass is reported in growth-retarded patients harboring mutations in the X-linked methyl-CpG-binding protein 2 (MECP2) gene causing Rett syndrome (RTT). We present the first study addressing both bone mineral density (BMD) and bone size in RTT. Our object was to determine whether patients...

  8. Green tea polyphenols mitigate bone loss of female rats in a chronic inflammation-induced bone loss model

    Science.gov (United States)

    The purpose of this study was to explore bioavailability, efficacy, and molecular mechanisms of green tea polyphenols (GTP) related to preventing bone loss in rats with chronic inflammation. A 2 (placebo vs. lipopolysaccharide, LPS) × 2 (no GTP vs. 0.5% GTP in drinking water) factorial design using ...

  9. Weight-loss-associated changes in bone mineral density and bone turnover after partial weight regain with or without aerobic exercise in obese women.

    Science.gov (United States)

    Hinton, P S; Rector, R S; Linden, M A; Warner, S O; Dellsperger, K C; Chockalingam, A; Whaley-Connell, A T; Liu, Y; Thomas, T R

    2012-05-01

    Moderate, long-term weight loss results in the loss of bone mass in overweight or obese premenopausal women. However, whether these changes persist during weight maintenance or regain remains to be determined. Overweight or obese (body mass index: 25.8-42.5 kg/m(2)) women (n=40) with at least two risk factors for the metabolic syndrome participated in this 12-month study that examined the effects of prescribed weight loss and regain, with or without exercise, on bone turnover and on bone mineral density (BMD) in a subset of participants (n=24). During the first 6 month, participants lost ≈ 10% of their initial body weight via energy restriction and supervised aerobic exercise. Following weight loss, participants were randomly assigned to either an exercise or a no exercise treatment for the regain (+50% of weight lost) phase. A one-way (time) repeated measures one-factor analysis of variance (RMANOVA) tested the effects of weight loss on BMD and bone turnover, and a two-way RMANOVA (time, exercise) was used to examine the effects of exercise during weight regain. Hip (P=0.007) and lumbar spine (P=0.05) BMD decreased with weight loss, and remained reduced after weight regain with or without exercise. Likewise, the weight-loss-associated increases in osteocalcin (Pexercise. The results of the present study, which is the first to examine changes in bone mass and turnover during carefully controlled weight regain, suggest that weight-loss-induced perturbations in bone mass and turnover persist after partial weight regain, regardless of whether regular weight-bearing aerobic exercise was continued.

  10. Structural joint damage and hand bone loss in patients with rheumatoid arthritis.

    Science.gov (United States)

    Lykke, Midtbøll Ørnbjerg

    2018-03-01

    no progression of structural joint damage during two years of TNF-inhibitor treatment, while hand bone loss remained increased compared to reference values from the general population in the majority of patients. Adalimumab had no impact on hand bone loss in the OPERA study.
 Existing structural joint damage, older age, IgM-rheumatoid factor positivity and concomitant treatment with prednisolone were independent predictors of progression in structural joint damage in the DANBIO X-ray cohort, while high hand bone loss in the first 6 months of treatment and placebo treatment were independently associated with increase in structural joint damage scores in the OPERA study. A high hand bone mass and disease activity were independent predictors of increased hand bone loss in the DANBIO X-ray study, while older age and high functional disability predicted hand bone loss in the OPERA study. High disease activity during treatment was associated with structural joint damage progression during TNF-inhibitor treatment in the DANBIO X-ray study and with hand bone loss in the DANBIO X-ray and OPERA studies. Articles published in the Danish Medical Journal are “open access”. This means that the articles are distributed under the terms of the Creative Commons Attribution Non-commercial License, which permits any non-commercial use, distribution, and reproduction in any medium, provided the original author(s) and source are credited.

  11. Proximal alveolar bone loss in a longitudinal radiographic investigation

    International Nuclear Information System (INIS)

    Bolin, A.; Lavstedt, S.; Henrikson, C.O.; Frithiof, L.

    1986-01-01

    The difference in proximal alveolar bone height between 1970 and 1980, the ''ABD index'', has been measured longitudinally in radiographs from an unselected material. The group constitutes 406 individuals born in 1904 - 1952 in the county of Stockholm. 13 of 18 predictors determined in 1970 were significantly related to the ABD index in the simple correlation analyses. The predictor ''the alveolar bone loss 1970'' (ABL index 1970) had the strongest correlation to the ABD index. In the stepwise multiple regression analysis the predictor ABL index 1970 and three other predictors reached significant levels. These were age, number of lost teeth and Russell's Periodontal Index

  12. Modeling the Mechanical Consequences of Age-Related Trabecular Bone Loss by XFEM Simulation.

    Science.gov (United States)

    Fan, Ruoxun; Gong, He; Zhang, Xianbin; Liu, Jun; Jia, Zhengbin; Zhu, Dong

    2016-01-01

    The elderly are more likely to suffer from fracture because of age-related trabecular bone loss. Different bone loss locations and patterns have different effects on bone mechanical properties. Extended finite element method (XFEM) can simulate fracture process and was suited to investigate the effects of bone loss on trabecular bone. Age-related bone loss is indicated by trabecular thinning and loss and may occur at low-strain locations or other random sites. Accordingly, several ideal normal and aged trabecular bone models were created based on different bone loss locations and patterns; then, fracture processes from crack initiation to complete failure of these models were observed by XFEM; finally, the effects of different locations and patterns on trabecular bone were compared. Results indicated that bone loss occurring at low-strain locations was more detrimental to trabecular bone than that occurring at other random sites; meanwhile, the decrease in bone strength caused by trabecular loss was higher than that caused by trabecular thinning, and the effects of vertical trabecular loss on mechanical properties were more severe than horizontal trabecular loss. This study provided a numerical method to simulate trabecular bone fracture and distinguished different effects of the possible occurrence of bone loss locations and patterns on trabecular bone.

  13. Modeling the Mechanical Consequences of Age-Related Trabecular Bone Loss by XFEM Simulation

    Directory of Open Access Journals (Sweden)

    Ruoxun Fan

    2016-01-01

    Full Text Available The elderly are more likely to suffer from fracture because of age-related trabecular bone loss. Different bone loss locations and patterns have different effects on bone mechanical properties. Extended finite element method (XFEM can simulate fracture process and was suited to investigate the effects of bone loss on trabecular bone. Age-related bone loss is indicated by trabecular thinning and loss and may occur at low-strain locations or other random sites. Accordingly, several ideal normal and aged trabecular bone models were created based on different bone loss locations and patterns; then, fracture processes from crack initiation to complete failure of these models were observed by XFEM; finally, the effects of different locations and patterns on trabecular bone were compared. Results indicated that bone loss occurring at low-strain locations was more detrimental to trabecular bone than that occurring at other random sites; meanwhile, the decrease in bone strength caused by trabecular loss was higher than that caused by trabecular thinning, and the effects of vertical trabecular loss on mechanical properties were more severe than horizontal trabecular loss. This study provided a numerical method to simulate trabecular bone fracture and distinguished different effects of the possible occurrence of bone loss locations and patterns on trabecular bone.

  14. Regulation of lean mass, bone mass, and exercise tolerance by the central melanocortin system.

    Directory of Open Access Journals (Sweden)

    Theodore P Braun

    Full Text Available Signaling via the type 4-melanocortin receptor (MC4R is an important determinant of body weight in mice and humans, where loss of function mutations lead to significant obesity. Humans with mutations in the MC4R experience an increase in lean mass. However, the simultaneous accrual of fat mass in such individuals may contribute to this effect via mechanical loading. We therefore examined the relationship of fat mass and lean mass in mice lacking the type-4 melanocortin receptor (MC4RKO. We demonstrate that MC4RKO mice display increased lean body mass. Further, this is not dependent on changes in adipose mass, as MC4RKO mice possess more lean body mass than diet-induced obese (DIO wild type mice with equivalent fat mass. To examine potential sources of the increased lean mass in MC4RKO mice, bone mass and strength were examined in MC4RKO mice. Both parameters increase with age in MC4RKO mice, which likely contributes to increases in lean body mass. We functionally characterized the increased lean mass in MC4RKO mice by examining their capacity for treadmill running. MC4R deficiency results in a decrease in exercise performance. No changes in the ratio of oxidative to glycolytic fibers were seen, however MC4RKO mice demonstrate a significantly reduced heart rate, which may underlie their impaired exercise performance. The reduced exercise capacity we report in the MC4RKO mouse has potential clinical ramifications, as efforts to control body weight in humans with melanocortin deficiency may be ineffective due to poor tolerance for physical activity.

  15. Physical activity influence on woman bone mass

    Directory of Open Access Journals (Sweden)

    Saray Giovana dos Santos

    2004-06-01

    Full Text Available This study aims to analyze the influence of physical activity performed in childhood, in adolescence, and at the time of the study on woman bone density. Two hundred volunteer women participated in the study by filling a standard questionnaire and having a bone densitometry done. The data were analyzed by frequencies, Student t test, and χ2 , at 0,05 level of significance and showed that: a the majority of women (173 practiced some kind of physical activity in the past and 166 have been practicing at the time of the study; b the physical activity characteristics can be consider within the patterns found in the literature; c bone loss among women who practiced physical activities in the childhood and adolescence was smaller than the ones had not practiced (p RESUMO Neste estudo objetivou-se analisar a influência da atividade física praticada na infância, na adolescência e atualmente, sobre a densidade óssea de mulheres. Participaram do estudo 200 mulheres voluntárias que responderam um formulário padronizado e realizaram densitometria óssea. Os dados analisados através de freqüências, teste t de Student e χ2 , evidenciaram que: a a maioria (173 das mulheres praticava algum tipo de atividade física no passado, e da mesma forma (166 atualmente; b as características das referidas práticas, podem ser consideradas dentro dos padrões recomendados pela literatura; c a perda óssea entre as mulheres que praticaram atividade física na infância e na adolescência foi menor (p<0,03 em relação às que não praticaram; entre as praticantes e não praticantes atuais não houve diferença significativa (p<0,73; d houve associação da densidade óssea com as variáveis: consumo diário de café (p<0,05; fases do climatério (p<0,001; uso atual de medicamentos prejudiciais à massa óssea ( p<0,05 e, com a ocorrência de doenças prejudiciais à massa óssea (p<0,01. Conclui-se que poucas variáveis interferiram na perda óssea das mulheres

  16. Feeding blueberry diets in early life prevent senescence of osteoblasts and bone loss in ovariectomized adult female rats.

    Directory of Open Access Journals (Sweden)

    Jian Zhang

    Full Text Available Appropriate nutrition during early development is essential for maximal bone mass accretion; however, linkage between early nutrition, childhood bone mass, peak bone mass in adulthood, and prevention of bone loss later in life has not been studied.In this report, we show that feeding a high quality diet supplemented with blueberries (BB to pre-pubertal rats throughout development or only between postnatal day 20 (PND20 and PND34 prevented ovariectomy (OVX-induced bone loss in adult life. This protective effect of BB is due to suppression of osteoblastic cell senescence associated with acute loss of myosin expression after OVX. Early exposure of pre-osteoblasts to serum from BB-fed rats was found to consistently increase myosin expression. This led to maintenance osteoblastic cell development and differentiation and delay of cellular entrance into senescence through regulation of the Runx2 gene. High bone turnover after OVX results in insufficient collagenous matrix support for new osteoblasts and their precursors to express myosin and other cytoskeletal elements required for osteoblast activity and differentiation.These results indicate: 1 a significant prevention of OVX-induced bone loss from adult rats can occur with only 14 days consumption of a BB-containing diet immediately prior to puberty; and 2 the molecular mechanisms underlying these effects involves increased myosin production which stimulates osteoblast differentiation and reduces mesenchymal stromal cell senescence.

  17. High fat diet attenuates hyperglycemia, body composition changes, and bone loss in male streptozotocin-induced type 1 diabetic mice.

    Science.gov (United States)

    Carvalho, Adriana Lelis; DeMambro, Victoria E; Guntur, Anyonya R; Le, Phuong; Nagano, Kenichi; Baron, Roland; de Paula, Francisco José Albuquerque; Motyl, Katherine J

    2018-02-01

    There is a growing and alarming prevalence of obesity and the metabolic syndrome in type I diabetic patients (T1DM), particularly in adolescence. In general, low bone mass, higher fracture risk, and increased marrow adipose tissue (MAT) are features of diabetic osteopathy in insulin-deficient subjects. On the other hand, type 2 diabetes (T2DM) is associated with normal or high bone mass, a greater risk of peripheral fractures, and no change in MAT. Therefore, we sought to determine the effect of weight gain on bone turnover in insulin-deficient mice. We evaluated the impact of a 6-week high-fat (HFD) rich in medium chain fatty acids or low-fat diet (LFD) on bone mass and MAT in a streptozotocin (STZ)-induced model using male C57BL/6J mice at 8 weeks of age. Dietary intervention was initiated after diabetes confirmation. At the endpoint, lower non-fasting glucose levels were observed in diabetic mice fed with high fat diet compared to diabetic mice fed the low fat diet (STZ-LFD). Compared to euglycemic controls, the STZ-LFD had marked polydipsia and polyphagia, as well as reduced lean mass, fat mass, and bone parameters. Interestingly, STZ-HFD mice had higher bone mass, namely less cortical bone loss and more trabecular bone than STZ-LFD. Thus, we found that a HFD, rich in medium chain fatty acids, protects against bone loss in a T1DM mouse model. Whether this may also translate to T1DM patients who are overweight or obese in respect to maintenance of bone mass remains to be determined through longitudinal studies. © 2017 Wiley Periodicals, Inc.

  18. Alveolar bone loss and mineralization in the pig with experimental periodontal disease

    Directory of Open Access Journals (Sweden)

    Mandee Yang

    2018-03-01

    Full Text Available Objective: To address how experimental periodontal disease affects alveolar bone mass and mineral apposition in a young pig model. Materials and methods: Seven three-month-old pigs were periodically inoculated with 4 types of periodontal bacteria, along with a ligature around the last maxillary deciduous molar for 8 weeks to induce periodontal disease (PG. Eight same-aged pigs served as the control (CG. Segmentations of 3D cone-beam CT images were performed to quantify volumes of the total alveolar bone, alveolar ridge, and all roots of the target molar. Calcein and alizarin were administered for labeling mineral apposition before euthanasia. The harvested molar blocks were sectioned and examined under epifluorescence. The inter-label distance between the two vital markers at regional bone surfaces were measured and mineral apposition rate (MAR was calculated. Results: A significant reduction of total alveolar bone volume was seen in PG with the major loss at the alveolar ridge. MAR was significantly higher at the root furcation region than those at both buccal and palatal ridges in CG. Compared with CG, PG animals showed more interrupted labeled bands with significantly lower MAR at the furcation region. MARs were positively associated with both the volumes of total alveolar bone and ridge in CG, but only with the total alveolar bone in PG. Conclusions: In young growing pigs, mineral apposition is region specific. The experimental periodontal disease not only leads to alveolar bone loss, but also perturbs mineral apposition for new bone formation, thus impairing the homeostasis of alveolar bone remodeling. Keyword: Dentistry

  19. Simulating Bone Loss in Microgravity Using Mathematical Formulations of Bone Remodeling

    Science.gov (United States)

    Pennline, James A.

    2009-01-01

    Most mathematical models of bone remodeling are used to simulate a specific bone disease, by disrupting the steady state or balance in the normal remodeling process, and to simulate a therapeutic strategy. In this work, the ability of a mathematical model of bone remodeling to simulate bone loss as a function of time under the conditions of microgravity is investigated. The model is formed by combining a previously developed set of biochemical, cellular dynamics, and mechanical stimulus equations in the literature with two newly proposed equations; one governing the rate of change of the area of cortical bone tissue in a cross section of a cylindrical section of bone and one governing the rate of change of calcium in the bone fluid. The mechanical stimulus comes from a simple model of stress due to a compressive force on a cylindrical section of bone which can be reduced to zero to mimic the effects of skeletal unloading in microgravity. The complete set of equations formed is a system of first order ordinary differential equations. The results of selected simulations are displayed and discussed. Limitations and deficiencies of the model are also discussed as well as suggestions for further research.

  20. Management of metaphyseal bone loss in revision knee arthroplasty.

    Science.gov (United States)

    Mancuso, Francesco; Beltrame, Arianna; Colombo, Elia; Miani, Enrick; Bassini, Fabrizio

    2017-06-07

    Revision total knee arthroplasty (TKA) is usually made more complex by the presence of bone defects, which may be caused by periprosthethic infection, polyethylene wear, implant loosening or fractures. The main aim of the present work is to review the available literature to understand the current options to manage with the bone loss during knee revisions. Available English literature for bone defects in revision TKAs has been evaluated looking at treatment options and their results in terms of clinical and radiological outcomes and failure rates. Anderson Orthopaedic Research Institute (AORI) classification is the most frequently used because it helps in the choice of the most suitable treatment. Several options are available in the management of metaphyseal bone loss in revision knee arthroplasty. For small and contained defects (AORI type 1) cement with or without screws and auto- or allograft morcellized bone are available. In uncontained but mild defects (AORI type 2A) metal augments should be use while large and uncontained defects (AORI type 2B and 3) are best addressed with structural allograft or metal filling devices (cones and sleeves). Stemmed components, either cemented or cementless, are recommended to reduce the strain at the interface implant-host. The treatment of bone defects in revision TKAs has evolved during the last years providing different options with good results at a short/medium term follow up. With the increasing revision burden, further scientific evidence is requested to identify the best approach for each patient. Long-term clinical outcome as well as implant survival after revision TKA are still sub-optimal and depend upon many factors including cause for revision, surgical approach, type of implants used and various patient factors.

  1. Basis of bone metabolism around dental implants during osseointegration and peri-implant bone loss.

    Science.gov (United States)

    Insua, Angel; Monje, Alberto; Wang, Hom-Lay; Miron, Richard J

    2017-07-01

    Despite the growing number of publications in the field of implant dentistry, there are limited studies to date investigating the biology and metabolism of bone healing around dental implants and their implications in peri-implant marginal bone loss. The aim of this review article is to provide a thorough understanding of the biological events taking place during osseointegration and the subsequent early and late phases of bone remodeling around dental implants. An update on the coupling mechanism occurring during bone resorption-bone remodeling is provided, focused on the relevance of the osteocytes, bone lining cells and immune cells during bone maintenance. An electronic and manual literature search was conducted by three independent reviewers in several databases, including MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, and Cochrane Oral Health Group Trials Register databases for articles up to September 2016 with no language restriction. Local bone metabolism is subject to signals from systemic calcium-phosphate homeostasis and bone remodeling. Three areas of interest were reviewed due to recent reported compromises in bone healing including the putative effects of (1) cholesterol, (2) hyperlipidemia, and (3) low vitamin D intake. Moreover, the prominent influence of osteocytes and immune cells is discussed as being key regulators during dental implant osseointegration and maintenance. These cells are of crucial importance in the presence of biofilm accumulation and their associated byproducts that leads to hard and soft tissue breakdown; the so called peri-implantitis. Factors that could negatively impact osteoclastogenesis or osteal macrophage activation should be monitored in future research including implant placement/torque protocols, bone characteristics, as well as meticulous maintenance programs to favor osseointegration and future long-term stability and success of dental implants. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res

  2. Coincidence of calcified carotid atheromatous plaque, osteoporosis, and periodontal bone loss in dental panoramic radiographs

    Energy Technology Data Exchange (ETDEWEB)

    Ramesh, Aruna; Ganguly, Rumpa [Dept. of Diagnosis and Health Promotion, Division of Oral and Maxillofacial Radiology, Tufts University School of Dental Medicine, Boston (United States); Soroushian, Sheila [Dept. of Orthodontics, Howard University College of Dentistry, Washington, DC(United States)

    2013-12-15

    This study was performed to assess the correlation of calcified carotid atheromatous plaque (CCAP), the mandibular cortical index, and periodontal bone loss in panoramic radiographs. One hundred eighty-five panoramic radiographs with CCAP and 234 without this finding were evaluated by 3 observers for the presence of osseous changes related to osteoporosis and periodontal bone loss. Chi-squared and Mann-Whitney U tests were used to compare the two groups for an association of CCAP with the mandibular cortical index and periodontal bone loss, respectively. There was a statistically significant coincidence of CCAP and osseous changes related to osteopenia/osteoporosis, with a p-value <0.001. There was no statistically significant coincidence of CCAP and periodontal bone loss. When comparing the 2 groups, 'With CCAP' and 'Without CCAP', there was a statistically significant association with the mean body mass index (BMI), number of remaining teeth, positive history of diabetes mellitus, and vascular accidents. There was no statistically significant association with gender or a history of smoking. This study identified a possible concurrence of CCAP and mandibular cortical changes secondary to osteopenia/osteoporosis in panoramic radiographs. This could demonstrate the important role of dental professionals in screening for these systemic conditions, leading to timely and appropriate referrals resulting in early interventions and thus improving overall health.

  3. Coincidence of calcified carotid atheromatous plaque, osteoporosis, and periodontal bone loss in dental panoramic radiographs

    International Nuclear Information System (INIS)

    Ramesh, Aruna; Ganguly, Rumpa; Soroushian, Sheila

    2013-01-01

    This study was performed to assess the correlation of calcified carotid atheromatous plaque (CCAP), the mandibular cortical index, and periodontal bone loss in panoramic radiographs. One hundred eighty-five panoramic radiographs with CCAP and 234 without this finding were evaluated by 3 observers for the presence of osseous changes related to osteoporosis and periodontal bone loss. Chi-squared and Mann-Whitney U tests were used to compare the two groups for an association of CCAP with the mandibular cortical index and periodontal bone loss, respectively. There was a statistically significant coincidence of CCAP and osseous changes related to osteopenia/osteoporosis, with a p-value <0.001. There was no statistically significant coincidence of CCAP and periodontal bone loss. When comparing the 2 groups, 'With CCAP' and 'Without CCAP', there was a statistically significant association with the mean body mass index (BMI), number of remaining teeth, positive history of diabetes mellitus, and vascular accidents. There was no statistically significant association with gender or a history of smoking. This study identified a possible concurrence of CCAP and mandibular cortical changes secondary to osteopenia/osteoporosis in panoramic radiographs. This could demonstrate the important role of dental professionals in screening for these systemic conditions, leading to timely and appropriate referrals resulting in early interventions and thus improving overall health.

  4. Inactivity-induced bone loss is not exacerbated by moderate energy restriction

    Science.gov (United States)

    Heer, M.; Boese, A.; Baecker, N.; Zittermann, A.; Smith, S. M.

    Severe energy restriction leads to decreased bone mineral density (BMD) in postmenopausal women, adolescent females, and in male athletes. Astronauts in space also lose bone mass, and most of them have reduced energy intake (about 25 % below requirements). The aim of our study was to examine if bone loss in space is partly induced by moderate energy restriction. Physiological changes of space flight were simulated by 6 head-down tilt bed rest (HDBR). Nine healthy male subjects (age: 23.6 ± 3.0 years; BMI: 23.0 ± 2.9 kg/m2, mean ± SD) finished four study phases, two of normocaloric nutrition, either ambulatory or HDBR, and two of hypocaloric nutrition, either ambulatory or HDBR. Urine samples (24 h) were analyzed for calcium excretion (UCaV) and bone resorption markers (C-Telopeptide, CTX, and N-Telopeptide, NTX). Serum calcium, parathyroid hormone (PTH) and bone formation markers (Procollagen-I-C-terminal-Peptide, PICP, Procollagen-I-N-terminal-Peptide, PINP, and bone-specific alkaline phosphatase, bAP) were analyzed. No significant changes in serum calcium or PTH were noted either during HDBR or during hypocaloric nutrition. PICP, but not PINP or bAP, decreased significantly during HDBR (normocaloric: pnutrition or both (pnutrition in ambulatory and HDBR phases. In conclusion, moderate energy restriction did not exaggerate bone resorption during HDBR.

  5. High-elevation mass loss of Greenland increasing

    DEFF Research Database (Denmark)

    Andersen, M. L.; Andersen, S. B.; Ahlstrøm, A. P.

    The Greenland Ice Sheet is losing mass at an accelerated pace. Presently, the mass loss is assumed to be distributed approximately equally between loss in the form of surface melt (surface mass balance, SMB) and solid ice discharge (iceberg calving, D) along the margins. As part of the PROMICE...

  6. Vitamin E decreases bone mass by stimulating osteoclast fusion.

    Science.gov (United States)

    Fujita, Koji; Iwasaki, Makiko; Ochi, Hiroki; Fukuda, Toru; Ma, Chengshan; Miyamoto, Takeshi; Takitani, Kimitaka; Negishi-Koga, Takako; Sunamura, Satoko; Kodama, Tatsuhiko; Takayanagi, Hiroshi; Tamai, Hiroshi; Kato, Shigeaki; Arai, Hiroyuki; Shinomiya, Kenichi; Itoh, Hiroshi; Okawa, Atsushi; Takeda, Shu

    2012-03-04

    Bone homeostasis is maintained by the balance between osteoblastic bone formation and osteoclastic bone resorption. Osteoclasts are multinucleated cells that are formed by mononuclear preosteoclast fusion. Fat-soluble vitamins such as vitamin D are pivotal in maintaining skeletal integrity. However, the role of vitamin E in bone remodeling is unknown. Here, we show that mice deficient in α-tocopherol transfer protein (Ttpa(-/-) mice), a mouse model of genetic vitamin E deficiency, have high bone mass as a result of a decrease in bone resorption. Cell-based assays indicated that α-tocopherol stimulated osteoclast fusion, independent of its antioxidant capacity, by inducing the expression of dendritic-cell-specific transmembrane protein, an essential molecule for osteoclast fusion, through activation of mitogen-activated protein kinase 14 (p38) and microphthalmia-associated transcription factor, as well as its direct recruitment to the Tm7sf4 (a gene encoding DC-STAMP) promoter. Indeed, the bone abnormality seen in Ttpa(-/-) mice was rescued by a Tm7sf4 transgene. Moreover, wild-type mice or rats fed an α-tocopherol-supplemented diet, which contains a comparable amount of α-tocopherol to supplements consumed by many people, lost bone mass. These results show that serum vitamin E is a determinant of bone mass through its regulation of osteoclast fusion.

  7. LRP5 mutations in osteoporosis-pseudoglioma syndrome and high-bone-mass disorders.

    Science.gov (United States)

    Levasseur, Régis; Lacombe, Didier; de Vernejoul, Marie Christine

    2005-05-01

    The LDL receptor-related protein 5 (LRP5) is a member of the LDL receptor family, which also includes the VLDL receptor and the apolipoprotein E receptor 2. The LRP5 is a co-receptor of Wnt located on the osteoblast membrane between two other receptors, Frizzled and Kremen. Frizzled and LRP5 bind to Wnt, thereby stabilizing beta-catenin and activating bone formation. When the dickkopf protein (Dkk) binds to Kremen and LRP5, this last undergoes internalization and therefore becomes unable to bind Wnt; this leads to degradation of beta-catenin and to inhibition of bone formation. In humans, loss of LRP5 function causes osteoporosis-pseudoglioma syndrome, which is characterized by congenital blindness and extremely severe childhood-onset osteoporosis (lumbar spine Z-score often LRP5, thereby increasing LRP5 function; the result is high bone mass due to uncoupling of bone formation and resorption. The Z-scores in this condition can exceed +6 at the hip and spine. The LRP5 and Wnt/beta-catenin reflect the level of bone formation and play a central role in bone mass accrual and normal distribution. Furthermore, LRP5 may contribute to mediate mechanical loads within bone tissue. Identification of the Wnt/beta-catenin pathway is a breakthrough in the elucidation of pathophysiological mechanisms affecting bone tissue and suggests new treatment targets for patients with osteoporosis or specific malignant conditions such as myeloma and sclerotic bone metastases.

  8. Corticosteroid therapy and bone mass - comparisOfl of rheumatoid ...

    African Journals Online (AJOL)

    periods, their bone mass was higher than that of the RA ... osteoclasts generated in cat bone marrow cultures, and .... Multiple regression analysis showed that these differences in the RA subgroups did not explain a significant proportion of the ariation in. 6MHS. A correlation matrix (Spearman) showed that in the RA.

  9. The loss of activating transcription factor 4 (ATF4) reduces bone toughness and fracture toughness.

    Science.gov (United States)

    Makowski, Alexander J; Uppuganti, Sasidhar; Wadeer, Sandra A; Whitehead, Jack M; Rowland, Barbara J; Granke, Mathilde; Mahadevan-Jansen, Anita; Yang, Xiangli; Nyman, Jeffry S

    2014-05-01

    Even though age-related changes to bone tissue affecting fracture risk are well characterized, only a few matrix-related factors have been identified as important to maintaining fracture resistance. As a gene critical to osteoblast differentiation, activating transcription factor 4 (ATF4) is possibly one of these important factors. To test the hypothesis that the loss of ATF4 affects the fracture resistance of bone beyond bone mass and structure, we harvested bones from Atf4+/+ and Atf4-/- littermates at 8 and 20 weeks of age (n≥9 per group) for bone assessment across several length scales. From whole bone mechanical tests in bending, femurs from Atf4-/- mice were found to be brittle with reduced toughness and fracture toughness compared to femurs from Atf4+/+ mice. However, there were no differences in material strength and in tissue hardness, as determined by nanoindentation, between the genotypes, irrespective of age. Tissue mineral density of the cortex at the point of loading as determined by micro-computed tomography was also not significantly different. However, by analyzing local composition by Raman Spectroscopy (RS), bone tissue of Atf4-/- mice was found to have higher mineral to collagen ratio compared to wild-type tissue, primarily at 20 weeks of age. From RS analysis of intact femurs at 2 orthogonal orientations relative to the polarization axis of the laser, we also found that the organizational-sensitive peak ratio, ν1Phosphate per Amide I, changed to a greater extent upon bone rotation for Atf4-deficient tissue, implying bone matrix organization may contribute to the brittleness phenotype. Target genes of ATF4 activity are not only important to osteoblast differentiation but also in maintaining bone toughness and fracture toughness. Published by Elsevier Inc.

  10. Increased risk for bone loss in women with systemic sclerosis: a comparative study with rheumatoid arthritis.

    Science.gov (United States)

    Kilic, Gamze; Kilic, Erkan; Akgul, Ozgur; Ozgocmen, Salih

    2016-04-01

    To assess bone mass in women with systemic sclerosis (SSc) in comparison to age and sex-matched patients with rheumatoid arthritis (RA), and to evaluate factors influencing bone mineral density (BMD). Patients were consecutively recruited and assessed for BMD at the lumbar spine and hip by dual-energy X-ray absorptiometry (DEXA) using a densitometer. In SSc, the extent of skin involvement, modified Rodnan skin thickness score (mRSS) and Medsger disease severity index were assessed. Forty-three patients with SSc and 38 age-matched patients with RA were included. There was no difference in BMD measurements between patients with diffuse or limited SSc. Patients with SSc had similar risk factors associated with osteoporosis (OP) or low bone mass except for low body mass index (BMI) and low vitamin D levels compared to patients with RA. Lumbar spinal BMD and T score were similar between groups. Total hip and femoral neck BMD and T score at femoral neck and total hip were significantly lower in patient with SSc versus RA. There was significant association between mRSS, Medsger severity score (peripheral vascular involvement and skin) and femoral BMD. There is an increased risk for bone loss in patients with SSc and the risk of OP is associated with disease severity, prolonged menopause and disease duration. The complex pathophysiology of bone metabolism as well as complex pathogenesis of the SSc pose some difficulty reaching clear-cut conclusions on the causal relationship between SSc and bone loss. © 2013 Asia Pacific League of Associations for Rheumatology and Wiley Publishing Asia Pty Ltd.

  11. Evaluating the risk of osteoporosis through bone mass density

    International Nuclear Information System (INIS)

    Sayed, S.A.; Khaliq, A.

    2017-01-01

    Osteoporosis is a bone disorder, characterized by loss of bone mass density. Osteoporosis affects more than 30 percent of post-menopausal women. Osteoporosis is often associated with restricted body movement, pain and joint deformities. Early identification and early intervention can help in reducing these complications. The primary objective of this study was to estimate the burden of Osteoporosis in Urban setting of Sindh among women of different age groups and to access the effect of different protective measures that can reduce the risk of Osteoporosis. Method: In this study, 500 women's of 3 major cities of Sindh were approached by non-probability convenience sampling technique. Women bearing age 20 years or more were included. Women who fall under inclusion criteria were screened for BMD (Bone mineral density) test and were classified as Healthy, Osteopenic and Osteoporotic based on their T-score. The association of different protective measures and risk of osteoporosis was assessed by prevalence relative risk (PRR). Result: The result of this study indicate that the burden of Osteoporosis is very high among the women of Sindh, only 17.4 percent (84) women were found to have normal BMD score. The life style of majority of women was sedentary. The PRR calculated for Exposure to sunlight, regular exercise, and use of nutritional supplement was 12.5, 5.19 and 2.72 folds respectively. Conclusion: The results of study reveal that exposure to sunlight, regular physical exercise and use of nutritional supplements found to be effective in reducing the risk of osteoporosis among women of all age group. Health education and promotion toward osteoporosis prevention can significantly contribute in reducing the morbidity of osteoporosis. (author)

  12. Preservation of bone mass and structure in hibernating black bears (Ursus americanus) through elevated expression of anabolic genes.

    Science.gov (United States)

    Fedorov, Vadim B; Goropashnaya, Anna V; Tøien, Øivind; Stewart, Nathan C; Chang, Celia; Wang, Haifang; Yan, Jun; Showe, Louise C; Showe, Michael K; Donahue, Seth W; Barnes, Brian M

    2012-06-01

    Physical inactivity reduces mechanical load on the skeleton, which leads to losses of bone mass and strength in non-hibernating mammalian species. Although bears are largely inactive during hibernation, they show no loss in bone mass and strength. To obtain insight into molecular mechanisms preventing disuse bone loss, we conducted a large-scale screen of transcriptional changes in trabecular bone comparing winter hibernating and summer non-hibernating black bears using a custom 12,800 probe cDNA microarray. A total of 241 genes were differentially expressed (P 1.4) in the ilium bone of bears between winter and summer. The Gene Ontology and Gene Set Enrichment Analysis showed an elevated proportion in hibernating bears of overexpressed genes in six functional sets of genes involved in anabolic processes of tissue morphogenesis and development including skeletal development, cartilage development, and bone biosynthesis. Apoptosis genes demonstrated a tendency for downregulation during hibernation. No coordinated directional changes were detected for genes involved in bone resorption, although some genes responsible for osteoclast formation and differentiation (Ostf1, Rab9a, and c-Fos) were significantly underexpressed in bone of hibernating bears. Elevated expression of multiple anabolic genes without induction of bone resorption genes, and the down regulation of apoptosis-related genes, likely contribute to the adaptive mechanism that preserves bone mass and structure through prolonged periods of immobility during hibernation.

  13. A quantification strategy for missing bone mass in case of osteolytic bone lesions

    International Nuclear Information System (INIS)

    Fränzle, Andrea; Giske, Kristina; Bretschi, Maren; Bäuerle, Tobias; Hillengass, Jens; Bendl, Rolf

    2013-01-01

    Purpose: Most of the patients who died of breast cancer have developed bone metastases. To understand the pathogenesis of bone metastases and to analyze treatment response of different bone remodeling therapies, preclinical animal models are examined. In breast cancer, bone metastases are often bone destructive. To assess treatment response of bone remodeling therapies, the volumes of these lesions have to be determined during the therapy process. The manual delineation of missing structures, especially if large parts are missing, is very time-consuming and not reproducible. Reproducibility is highly important to have comparable results during the therapy process. Therefore, a computerized approach is needed. Also for the preclinical research, a reproducible measurement of the lesions is essential. Here, the authors present an automated segmentation method for the measurement of missing bone mass in a preclinical rat model with bone metastases in the hind leg bones based on 3D CT scans. Methods: The affected bone structure is compared to a healthy model. Since in this preclinical rat trial the metastasis only occurs on the right hind legs, which is assured by using vessel clips, the authors use the left body side as a healthy model. The left femur is segmented with a statistical shape model which is initialised using the automatically segmented medullary cavity. The left tibia and fibula are segmented using volume growing starting at the tibia medullary cavity and stopping at the femur boundary. Masked images of both segmentations are mirrored along the median plane and transferred manually to the position of the affected bone by rigid registration. Affected bone and healthy model are compared based on their gray values. If the gray value of a voxel indicates bone mass in the healthy model and no bone in the affected bone, this voxel is considered to be osteolytic. Results: The lesion segmentations complete the missing bone structures in a reasonable way. The mean

  14. The Effect Of Body Mass Index On Bone Mineral Density In Postmenopausal Women - Original Investigation

    Directory of Open Access Journals (Sweden)

    Burcu Yanık

    2007-09-01

    Full Text Available Aim: We aimed to determine the relationship between bone mineral density and body mass index in postmenopausal women. Material and Methods: 54 postmenopausal women were included in the study. Age and time of menopause were recorded. Smoking, alcohol and exercise status were also recorded. Weight and height were measured and body mass index was calculated. The patients were separated into four groups according to their body mass index, as underweight, ideal weight, over-weight and obese. Bone mineral density in all the patients was assessed via dual energy X-ray absorptiometry from antero-posterior lumbar and right proximal femoral regions. For L2-4 and the femoral neck, bone mineral density and t scores were determined. Results: The study was performed in 54 postmenopausal women, ranging in age from 51 to 79 years. 22 (%40.8 of the patients were obese, 24 (%44.4 were overweight and 8 (%14.8 had ideal weight. There were no patients in underweight group. There were no difference in age, smoking, time of menopause, bone mineral density and t-scores among the groups. There was statistically significant correlation between body mass index and bone mineral density of the femoral neck (r =0.407, p=0.002, and femoral neck t-scores (r =0.297, p=0.029. There was no significant correlation between the body mass index and lumbar bone mineral density and lumbar t-scores (p >0.05. Conclusion: Body mass index was found to be related to bone mineral density of the femoral neck. Our findings suggest that maintenance of adequate body mass is important for the prevention of postmenopausal bone loss. (From the World of Osteoporosis 2007;13:56-9

  15. Specific bone mass acquisition in elite female athletes.

    Science.gov (United States)

    Maïmoun, Laurent; Coste, Olivier; Mura, Thibault; Philibert, Pascal; Galtier, Florence; Mariano-Goulart, Denis; Paris, Françoise; Sultan, Charles

    2013-07-01

    Cross-sectional studies have demonstrated that physical activity can improve bone mass acquisition. However, this design is not adequate to describe the specific kinetics of bone mass gain during pubertal development. To compare the kinetics of bone mass acquisition in female adolescent athletes of sports that impose different mechanical loads and untrained controls throughout puberty. A total of 72 girls with ages ranging from 10.8 to 18.0 years were recruited: 24 rhythmic gymnasts (RG, impact activity group), 24 swimmers (SW, no-impact activity), and 24 age-matched controls (CON). Areal bone mineral density (aBMD) was determined using dual-energy x-ray absorptiometry and bone turnover markers were analyzed. All the investigations were performed at baseline and after 1 year. At baseline and after 1 year of follow-up, RG presented significantly greater aBMD adjusted for age, fat-free soft tissue, and fat mass compared with CON and SW, only at the femoral region. When aBMD variation throughout the pubertal period was modeled for each group from individual values, the aBMD at the femoral region was significantly higher in RG compared with the other 2 groups from 12.5 to 14 years, and this difference lasted up to 18 years. Moreover, the mean annual aBMD gain tended to be higher in RG compared with SW and CON only at the femoral region and this gain lasted longer in RG. Bone remodeling markers decreased similarly with age in the 3 groups. This study, which was based on linear mixed models for longitudinal data, demonstrated that the osteogenic effect of gymnastics is characterized by greater bone mass gain localized at mechanically loaded bone (ie, the proximal femur) principally around the menarcheal period. Moreover, the bone mass gain lasts longer in gymnasts, which may be explained by the delay in sexual maturation.

  16. Exercise and pharmacological countermeasures for bone loss during long-duration space flight

    Science.gov (United States)

    Cavanagh, Peter R.; Licata, Angelo A.; Rice, Andrea J.

    2005-01-01

    Bone loss in the lower extremities and lumbar spine is an established consequence of long-duration human space flight. Astronauts typically lose as much bone mass in the proximal femur in 1 month as postmenopausal women on Earth lose in 1 year. Pharmacological interventions have not been routinely used in space, and countermeasure programs have depended solely upon exercise. However, it is clear that the osteogenic stimulus from exercise has been inadequate to maintain bone mass, due to insufficient load or duration. Attention has therefore been focused on several pharmacological interventions that have been successful in preventing or attenuating osteoporosis on Earth. Anti-resorptives are the class of drugs most commonly used to treat osteoporosis in postmenopausal women, notably alendronate sodium, risedronate sodium, zoledronic acid, and selective estrogen receptor modulators, such as raloxifene. There has also been considerable recent interest in anabolic agents such as parathyroid hormone (PTH) and teriparatide (rhPTH [1-34]). Vitamin D and calcium supplementation have also been used. Recent studies of kindreds with abnormally high bone mineral density have provided insight into the genetic regulation of bone mass. This has led to potential therapeutic interventions based on the LRP5, Wnt and BMP2 pathways. Another target is the RANK-L/osteoprotegerin signaling pathway, which influences bone turnover by regulating osteoclast formation and maturation. Trials using such therapies in space are being planned. Among the factors to be considered are dose-response relationships, bone quality, post-use recovery, and combination therapies--all of which may have unique characteristics when the drugs are used in space.

  17. Marginal bone loss in implants placed in grafted maxillary sinus.

    Science.gov (United States)

    Galindo-Moreno, Pablo; Fernández-Jiménez, Andrés; O'Valle, Francisco; Silvestre, Francisco J; Sánchez-Fernández, Elena; Monje, Alberto; Catena, Andrés

    2015-04-01

    The purpose of this study is to evaluate the vertical and horizontal graft bone resorption (GR) in grafted maxillary sinuses and the marginal bone loss (MBL) around implants placed in the sinuses with different prosthetic connections and to determine the effect of other clinical factors on these tissue responses at 6 and 18 months postloading. A total of 254 implants were placed in 150 grafted maxillary sinuses of 101 patients (51.5% female) with mean age of 52.2 years (range, 32-82 years). GR and MBL measurements were made in implants placed with two different prosthetic connections (internal and external) at 6 and 18 months postloading. The complex samples general linear model was used to analyze the influence of patient age, gender, smoking habit, history of periodontal disease, implantation timing (simultaneous vs deferred), and prosthetic abutment length on radiographic GR and MBL values. At 18 months postloading, the MBL ranged from 0 mm to 5.89 mm; less than 1 mm was lost around 49.0% (mesial) and 44.3% (distal) of the implants, while no bone was lost around 32.9% (mesial) and 26.7% (distal). The GR was significantly affected by smoking, remnant alveolar bone height, graft length, graft height, gender, and age, and it significantly decreased over time. The MBL was influenced by the type of connection, implantation timing, and prosthetic abutment length. The MBL was greater with longer postloading interval and higher patient age and in smokers. Resorption of grafts that combine autogenous cortical bone with anorganic bovine bone is dependent on the anatomic features of the sinus and is not affected by the time elapsed after the first 6 months. The MBL in implants placed in these grafted areas is time dependent and mainly related to potentially modifiable clinical decisions and patient habits. © 2013 Wiley Periodicals, Inc.

  18. Artificial Gravity as a Bone Loss Countermeasure in Simulated Weightlessness

    Science.gov (United States)

    Smith, S. M.; Zwart, S. R.; Crawford, G. E.; Gillman, P. L.; LeBlanc, A.; Shackelford, L. C.; Heer, M. A.

    2007-01-01

    The impact of microgravity on the human body is a significant concern for space travelers. We report here initial results from a pilot study designed to explore the utility of artificial gravity (AG) as a countermeasure to the effects of microgravity, specifically to bone loss. After an initial phase of adaptation and testing, 15 male subjects underwent 21 days of 6 head-down bed rest to simulate the deconditioning associated with space flight. Eight of the subjects underwent 1 h of centrifugation (AG, 1 gz at the heart, 2.5 gz at the feet) each day for 21 days, while 7 of the subjects served as untreated controls (CN). Blood and urine were collected before, during, and after bed rest for bone marker determinations. At this point, preliminary data are available on the first 8 subjects (6 AG, and 2 CN). Comparing the last week of bed rest to before bed rest, urinary excretion of the bone resorption marker n-telopeptide increased 95 plus or minus 59% (mean plus or minus SD) in CN but only 32 plus or minus 26% in the AG group. Similar results were found for another resorption marker, helical peptide (increased 57 plus or minus 0% and 35 plus or minus 13% in CN and AG respectively). Bone-specific alkaline phosphatase, a bone formation marker, did not change during bed rest. At this point, sample analyses are continuing, including calcium tracer kinetic studies. These initial data demonstrate the potential effectiveness of short-radius, intermittent AG as a countermeasure to the bone deconditioning that occurs during bed rest.

  19. Comparison of Bone Loss around Bone Platform Shift and Non-Bone Platform Shift Implants After 12 Months

    Directory of Open Access Journals (Sweden)

    AmirReza Rokn

    2015-10-01

    Full Text Available Objectives: The aim of the present randomized clinical trial was to evaluate marginal bone loss around two types of implants modified at the neck area: Nobel Active and Nobel Replace Groovy, both manufactured by Nobel Biocare.Materials and Methods: A total of 25 Nobel Active and 21 Nobel Replace Groovy implants were included in the present study. The implants were placed based on the relevant protocol and patient inclusion and exclusion criteria. The amount of bone loss around implants was compared at 6 and 12-month intervals using digital periapical radiographs.Results: The mean bone loss values in the Nobel Active and Nobel Replace Groovy groups were 0.682 mm and 0.645 mm, respectively, with no statistically significant difference based on the results of independent t-test (P=0.802.Conclusion: Use of both implant types yielded favorable results, with high durability.The two implant types exhibited no superiority over each other in terms of bone loss.

  20. Aerobic Exercise and Whole-Body Vibration in Offsetting Bone Loss in Older Adults

    Directory of Open Access Journals (Sweden)

    Pei-Yang Liu

    2011-01-01

    Full Text Available Osteoporosis and its associated fractures are common complications of aging and most strategies to prevent and/or treat bone loss focused on antiresorptive medications. However, aerobic exercise (AEX and/or whole-body vibration (WBV might have beneficial effect on bone mass and provide an alternative approach to increase or maintain bone mineral density (BMD and reduce the risk of fractures. The purpose of this paper was to investigate the potential benefits of AEX and WBV on BMD in older population and discuss the possible mechanisms of action. Several online databases were utilized and based on the available literature the consensus is that both AEX and WBV may increase spine and femoral BMD in older adults. Therefore, AEX and WBV could serve as nonpharmacological and complementary approaches to increasing/maintaining BMD. However, it is uncertain if noted effects could be permanent and further studies are needed to investigate sustainability of either type of the exercise.

  1. Severe Bone Loss as Part of the Life History Strategy of Bowhead Whales.

    Directory of Open Access Journals (Sweden)

    John C George

    Full Text Available The evolution of baleen constituted a major evolutionary change that made it possible for baleen whales to reach enormous body sizes while filter feeding on tiny organisms and migrating over tremendous distances. Bowhead whales (Balaena mysticetus live in the Arctic where the annual cycle of increasing and decreasing ice cover affects their habitat, prey, and migration. During the nursing period, bowheads grow rapidly; but between weaning and approximately year 5, bowhead whales display sustained baleen and head growth while limiting growth in the rest of their bodies. During this period, they withdraw resources from the skeleton, in particular the ribs, which may lose 40% of bone mass. Such dramatic changes in bones of immature mammals are rare, although fossil cetaceans between 40 and 50 million years ago show an array of rib specializations that include bone loss and are usually interpreted as related to buoyancy control.

  2. Body composition, bone turnover, and bone mass in trans men during testosterone treatment: 1-year follow-up data from a prospective case-controlled study (ENIGI).

    Science.gov (United States)

    Van Caenegem, E; Wierckx, K; Taes, Y; Schreiner, T; Vandewalle, S; Toye, K; Lapauw, B; Kaufman, J-M; T'Sjoen, G

    2015-02-01

    To assess the evolution of body composition and bone metabolism in trans men during the first year of cross-sex hormonal therapy. In a prospective controlled study, we included 23 trans men (female-to-male trans persons) and 23 age-matched control women. In both groups, we examined grip strength (hand dynamometer), biochemical markers of bone turnover (C-terminal telopeptides of type 1 collagen (CTX) and procollagen 1 aminoterminal propeptide (P1NP)), total body fat and lean mass, and areal bone mineral density (aBMD) by dual-X-ray absorptiometry (DXA) and fat and muscle area at the forearm and calf, bone geometry, and volumetric bone mineral density (vBMD) by peripheral quantitative computed tomography (pQCT), before treatment and after 1 year of treatment with undecanoate (1000 mg i.m./12 weeks). Before hormonal treatment, trans men had similar bone and body composition compared with control women. Testosterone treatment induced in trans men a gain in muscle mass (+10.4%) and strength and loss of fat mass (-9.7%) (all Ptrans men (P=0.036 and P=0.001 respectively). None of these changes were observed in the control group. Short-term testosterone treatment in trans men increased muscle mass and bone turnover. The latter may rather reflect an anabolic effect of testosterone treatment rather than bone loss. © 2015 European Society of Endocrinology.

  3. Zanthoxylum piperitum reversed alveolar bone loss of periodontitis via regulation of bone remodeling-related factors.

    Science.gov (United States)

    Kim, Mi Hye; Lee, Hye Ji; Park, Jung-Chul; Hong, Jongki; Yang, Woong Mo

    2017-01-04

    Zanthoxylum piperitum (ZP) has been used to prevent toothache in East Asia. In this study, we investigated the effects of ZP on periodontitis along with alveolar bone loss. Twenty-eight male Sprague-Dawley rats were assigned into 4 groups; non-ligated (NOR), ligated and treated vehicle (CTR), ligated and treated 1mg/mL ZP (ZP1), and ligated and treated 100mg/mL ZP (ZP100). Sterilized 3-0 nylon ligature was placed into the subgingival sulcus around the both sides of mandibular first molar. After topical application of 1 and 100mg/mL ZP for 2 weeks, mandibles was removed for histology. In addition, SaOS-2 osteoblast cells were treated 1, 10 and 100μg/mL ZP for 24h to analyze the expressions of alveolar bone-related markers. Several alveolar bone resorption pits, which indicate cementum demineralization were decreased by ZP treatment. Topical ZP treatment inhibited periodontitis-induced alveolar bone loss. In addition, there were significant reduction of osteoclastic activities following topical ZP treatment in periodontium. The expression of RANKL was decreased in SaOS-2 osteoblast cells by treating ZP, while that of OPG was increased. ZP treatment increased the expressions of Runx2 and Osterix in SaOS-2 cells. In summary, ZP treatment inhibited alveolar bone loss as well as maintained the integrity of periodontal structures via regulation of bone remodeling. ZP may be a therapeutic target for treating periodontitis. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  4. The effect on bone mass and bone markers of different doses of ibandronate

    DEFF Research Database (Denmark)

    Ravn, Pernille; Clemmesen, B; Riis, B J

    1996-01-01

    The present article describes the results from a phase II dose finding study of the effect of ibandronate, a new, third generation bisphosphonate, in postmenopausal osteoporosis. One hundred and eighty postmenopausal, white women, at least 10 years past a natural menopause, with osteopenia defined...... calcium supplementation of 1000 mg Ca2+. Bone mass and biochemical markers of bone turnover were measured every 3 months throughout the study period. The average changes in bone mass showed positive outcome in all regions in the groups receiving ibandronate 2.5 and 5.0 mg. The responses in the two groups...... femur (p changes in bone mass in the group receiving calcium (placebo) and ibandronate 0.25 mg. Dose-related responses were found in all biochemical markers of bone turnover...

  5. Neuropeptide Y knockout mice reveal a central role of NPY in the coordination of bone mass to body weight.

    Directory of Open Access Journals (Sweden)

    Paul A Baldock

    Full Text Available Changes in whole body energy levels are closely linked to alterations in body weight and bone mass. Here, we show that hypothalamic signals contribute to the regulation of bone mass in a manner consistent with the central perception of energy status. Mice lacking neuropeptide Y (NPY, a well-known orexigenic factor whose hypothalamic expression is increased in fasting, have significantly increased bone mass in association with enhanced osteoblast activity and elevated expression of bone osteogenic transcription factors, Runx2 and Osterix. In contrast, wild type and NPY knockout (NPY (-/- mice in which NPY is specifically over expressed in the hypothalamus (AAV-NPY+ show a significant reduction in bone mass despite developing an obese phenotype. The AAV-NPY+ induced loss of bone mass is consistent with models known to mimic the central effects of fasting, which also show increased hypothalamic NPY levels. Thus these data indicate that, in addition to well characterized responses to body mass, skeletal tissue also responds to the perception of nutritional status by the hypothalamus independently of body weight. In addition, the reduction in bone mass by AAV NPY+ administration does not completely correct the high bone mass phenotype of NPY (-/- mice, indicating the possibility that peripheral NPY may also be an important regulator of bone mass. Indeed, we demonstrate the expression of NPY specifically in osteoblasts. In conclusion, these data identifies NPY as a critical integrator of bone homeostatic signals; increasing bone mass during times of obesity when hypothalamic NPY expression levels are low and reducing bone formation to conserve energy under 'starving' conditions, when hypothalamic NPY expression levels are high.

  6. MicroCT evaluation of bone mineral density loss in human bones

    Energy Technology Data Exchange (ETDEWEB)

    Nogueira, Liebert P.; Braz, Delson; Lopes, Ricardo T. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia (COPPE). Lab. de Instrumentacao Nuclear]. E-mails: lnogueira@con.ufrj.br; Barroso, Regina C.; Oliveira, Luis F. [Universidade do Estado do Rio de Janeiro (UERJ), Rio de Janeiro, RJ (Brazil). Inst. de Fisica]. E-mail: cely@uerj.br

    2007-07-01

    Bone is a connective tissue largely composed of an organic protein, collagen and the inorganic mineral hydroxyapatite [Ca{sub 10}(PO{sub 4}){sub 6}OH{sub 2}], which combine to provide a mechanical and supportive role in the body. Depending on the orientation of collagen fibers, two types of bone can be distinguished: trabecular and cortical bone. Degree of mineralization is considered an important feature of bone quality. Changes in the degree of mineralization is generally due to osteoporosis, but many recent studies have already shown that alterations in degree of mineralization can occur due to a large variety of factors. The transmission X-ray microtomography is one of the most popular methods, which provides the spatial distribution of the total absorption coefficient inside the sample. The aim of this study was to investigate the suitability of using microCT as a supplementary tool for the diagnosis of the health status of human bones. Eleven samples were constructed simulating the physiological range of bone mineral density (BMD) found in cortical human bone. The samples represent healthy mixtures of swine compact bone dried at room temperature, powdered and mixed with fat (0 - 100 % by mass). The samples were imaged by a microfocus tube (Fein-Focus) with focal size of about 60 {mu}m ({+-}5%), and a CCD camera (0.143 mm pixel size) coupled with an intensifier tube with fluoroscope screen at the Nuclear Instrumentation Laboratory (COPPE/UFRJ), Brazil. The images were reconstructed and treated with suitable software developed at the Nuclear Instrumentation Laboratory. The mineral content in cortical bone is defined by the volume of dry, fat-free bone per unit bulk volume of the bone. The volumes were calculated from the bone density using the relationship between volume and density. The densities of fat and bone were taken to be 0.95 g.cm{sup -3} and 1.92 g.cm{sup -3} respectively. The correlation of the measured absorption coefficient with the mineral content

  7. CD38 is associated with premenopausal and postmenopausal bone mineral density and postmenopausal bone loss.

    LENUS (Irish Health Repository)

    Drummond, Frances J

    2012-02-03

    One goal of osteoporosis research is to identify the genes and environmental factors that contribute to low bone mineral density (BMD) and fracture. Linkage analyses have identified quantitative trait loci (QTLs), however, the genes contributing to low BMD are largely unknown. We examined the potential association of an intronic polymorphism in CD38 with BMD and postmenopausal bone loss. CD38 resides in 4p15, where a QTL for BMD has been described. CD38-\\/- mice display an osteoporotic phenotype at 3 months, with normalization of BMD by 5 months. The CD38 polymorphism was identified by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis in 457 postmenopausal and 173 premenopausal Caucasian women whose spine and hip BMD was measured by dual energy X-ray absorptiometry (DXA). Influence of the CD38 polymorphism on bone loss was analyzed in 273 postmenopausal women over a follow-up of 2.94 +\\/- 1.50 years. The CD38-PvuII polymorphism was significantly associated with premenopausal and postmenopausal (P = 0.001) lumbar spine BMD. Women homozygous for the G allele had >14% lower spinal BMD than women with GC\\/CC genotypes. An allele dose effect was observed at the spine in premenopausal (P = 0.002) and postmenopausal (P < 0.001) cohorts. The CD38-PvuII polymorphism was significantly associated with femoral neck BMD in pre- and postmenopausal women (P = 0.002 and P = 0.011, respectively). However, significance was lost following adjustment of hip BMD for covariates in the postmenopausal cohort (P = 0.081). The CD38-PvuII polymorphism was weakly associated with bone loss at the spine (P = 0.024), in postmenopausal women not taking hormone replacement therapy. We suggest that the CD38-PvuII polymorphism may influence the attainment and maintenance of peak BMD and postmenopausal bone loss.

  8. High bone turnover is associated with low bone mass in both pre- and postmenopausal women

    DEFF Research Database (Denmark)

    Ravn, Pernille; Fledelius, C; Rosenquist, C

    1996-01-01

    In 979 healthy women, aged 30-75 years, bone mass was measured by DXA in the lumbar spine and proximal femur, and by SXA in the distal forearm. Bone turnover was assessed by urinary CrossLaps (CrossLaps ELISA), a new assay which measures type I collagen degradation products in urine and by osteoc......In 979 healthy women, aged 30-75 years, bone mass was measured by DXA in the lumbar spine and proximal femur, and by SXA in the distal forearm. Bone turnover was assessed by urinary CrossLaps (CrossLaps ELISA), a new assay which measures type I collagen degradation products in urine...... of CrossLaps and OCN-Mid corrected for height and weight, had 6%-11% lower bone mass in all regions (p mass in the spine and proximal femur, r = -0.13 to r = -0.28, p ....05. In postmenopausal women, the difference in bone mass between the highest and lowest quartiles was 8%-14% (p mass measured in all regions, r = -0.14 to r = -0.32, p mass and AP and Fu Hpr/Cr was lower; r = -0.06 to r = -0...

  9. Bone mineral mass and bone turnover parameters in osteoporosis

    NARCIS (Netherlands)

    R.J. Erdtsieck (Ronald)

    1996-01-01

    textabstractIn the past decades osteoporosis has been recognized as an important public health problem. Several causes for this problem can be pointed out. The most probable cause for the development of osteoporosis is the loss of ovarian function in women and the increasing age of people, thereby

  10. Lack of influence of simple premenopausal hysterectomy on bone mass and bone metabolism

    DEFF Research Database (Denmark)

    Ravn, Pernille; Lind, C; Nilas, L

    1995-01-01

    OBJECTIVE: Our purpose was to investigate the influence of premenopausal hysterectomy on bone mass. STUDY DESIGN: A cross-sectional study was performed on 69 women who had premenopausal hysterectomy and 427 women with natural menopause 50 to 59 years old. Bone mineral density was measured in the ...

  11. DXA measurements in Rett syndrome reveal small bones with low bone mass.

    Science.gov (United States)

    Roende, Gitte; Ravn, Kirstine; Fuglsang, Kathrine; Andersen, Henrik; Nielsen, Jytte Bieber; Brøndum-Nielsen, Karen; Jensen, Jens-Erik Beck

    2011-09-01

    Low bone mass is reported in growth-retarded patients harboring mutations in the X-linked methyl-CpG-binding protein 2 (MECP2) gene causing Rett syndrome (RTT). We present the first study addressing both bone mineral density (BMD) and bone size in RTT. Our object was to determine whether patients with RTT do have low BMD when correcting for smaller bones by examination with dual-energy X-ray absorptiometry (DXA). We compared areal BMD (aBMD(spine) and aBMD(total hip) ) and volumetric bone mineral apparent density (vBMAD(spine) and vBMAD(neck) ) in 61 patients and 122 matched healthy controls. Further, spine and hip aBMD and vBMAD of patients were associated with clinical risk factors of low BMD, low-energy fractures, MECP2 mutation groups, and X chromosome inactivation (XCI). Patients with RTT had reduced bone size on the order of 10% and showed lower values of spine and hip aBMD and vBMAD (p bone mass and small bones are evident in RTT, indicating an apparent low-bone-formation phenotype. Copyright © 2011 American Society for Bone and Mineral Research.

  12. Protective effect of low-dose risedronate against osteocyte apoptosis and bone loss in ovariectomized rats.

    Directory of Open Access Journals (Sweden)

    Tingjun Ye

    Full Text Available Osteocyte apoptosis is the first reaction to estrogen depletion, thereby stimulating osteoclastic bone resorption resulting in bone loss. We investigated the effects of two different risedronate (RIS doses (high and low on osteocyte apoptosis, osteoclast activity and bone loss in ovariectomized rats. Forty rats with ovariectomy (OVX and sham ovariectomy (SHAM were divided into 4 groups: 1 SHAM rats treated with saline (SHAM; 2 OVX rats treated with saline (OVX; 3 OVX rats treated with low-dose RIS (OVX-LR, 0.08 μg/kg/day; 4 OVX rats treated with high-dose RIS (OVX-HR, 0.8 μg/kg/day. All animals were sacrificed 90 days after surgery for the examinations of osteocyte apoptosis by caspase-3 staining, osteoclast activity by TRAP staining and bone volume by micro-CT scanning in lumbar vertebral cancellous bone. Both low and high dose RIS significantly reduced caspase-3 positive osteocytes, empty lacunae and TRAP positive osteoclasts in OVX rats. Although the difference in caspase-3 positive osteocytes was not significant between the OVX-LR and OVX-HR groups, numerically these cells were significantly more prevalent in OVX-HR (not OVX-LR group than in SHAM group. TRAP positive osteoclasts were significantly higher in OVX-LR group than in SHAM or OVX-HR group. There was no significant difference in bone volume among the OVX-LR, OVX-HR and SHAM groups, but lower in OVX group alone. However, significant increase in trabecular thickness only occurred in OVX-LR group. We conclude that both low and high dose RIS significantly inhibit osteocyte apoptosis and osteoclast activity in OVX rats, but the low-dose RIS has weaker effect on osteoclast activity. However, low-dose RIS preserves cancellous bone mass and microarchitecture as well as high-dose RIS after estrogen depletion.

  13. Marginal bone loss around implants placed in maxillary native bone or grafted sinuses: a retrospective cohort study.

    Science.gov (United States)

    Galindo-Moreno, P; Fernández-Jiménez, A; Avila-Ortiz, G; Silvestre, F J; Hernández-Cortés, P; Wang, H L

    2014-03-01

    To assess differences in marginal bone loss around implants placed in maxillary pristine bone and implants placed following maxillary sinus augmentation over a period of 3 years after functional loading. Two cohorts of subjects (Group 1: Subjects who received sinus augmentation with simultaneous implant placement; Group 2: Subjects who underwent conventional implant placement in posterior maxillary pristine bone) were included in this retrospective study. Radiographic marginal bone loss was measured around one implant per patient on digitized panoramic radiographs that were obtained at the time of prosthesis delivery (baseline) and 12, 24, and 36 months later. The influence of age, gender, smoking habits, history of periodontal disease, and type of prosthetic connection (internal or external) on marginal bone loss was analyzed in function of the type of osseous support (previously grafted or pristine). A total of 105 subjects were included in this study. Cumulative radiographic marginal bone loss ranged from 0 mm to 3.9 mm after 36 months of functional loading. There were statistically significant differences in marginal bone loss between implants placed in grafted and pristine bone at the 12-month assessment, but not in the subsequent progression rate. External prosthetic connection, smoking, and history of periodontitis negatively influenced peri-implant bone maintenance, regardless of the type of osseous substrate. Implants placed in sites that received maxillary sinus augmentation exhibited more marginal bone loss than implants placed in pristine bone, although marginal bone loss mainly occurred during the first 12 months after functional loading. Implants with external implant connection were strongly associated with increased marginal bone loss overtime. © 2013 John Wiley & Sons A/S. Published by Blackwell Publishing Ltd.

  14. Bone turnover markers in peripheral blood and marrow plasma reflect trabecular bone loss but not endocortical expansion in aging mice.

    Science.gov (United States)

    Shahnazari, Mohammad; Dwyer, Denise; Chu, Vivian; Asuncion, Frank; Stolina, Marina; Ominsky, Michael; Kostenuik, Paul; Halloran, Bernard

    2012-03-01

    We examined age-related changes in biochemical markers and regulators of osteoblast and osteoclast activity in C57BL/6 mice to assess their utility in explaining age-related changes in bone. Several recently discovered regulators of osteoclasts and osteoblasts were also measured to assess concordance between their systemic levels versus their levels in marrow plasma, to which bone cells are directly exposed. MicroCT of 6-, 12-, and 24-month-old mice indicated an early age-related loss of trabecular bone volume and surface, followed by endocortical bone loss and periosteal expansion. Trabecular bone loss temporally correlated with reductions in biomarkers of bone formation and resorption in both peripheral blood and bone marrow. Endocortical bone loss and periosteal bone gain were not reflected in these protein biomarkers, but were well correlated with increased expression of osteocalcin, rank, tracp5b, and cathepsinK in RNA extracted from cortical bone. While age-related changes in bone turnover markers remained concordant in blood versus marrow, aging led to divergent changes in blood versus marrow for the bone cell regulators RANKL, OPG, sclerostin, DKK1, and serotonin. Bone expression of runx2 and osterix increased progressively with aging and was associated with an increase in the number of osteoprogenitors and osteoclast precursors. In summary, levels of biochemical markers of bone turnover in blood and bone marrow plasma were predictive of an age-related loss of trabecular surfaces in adult C57BL/6 mice, but did not predict gains in cortical surfaces resulting from cortical expansion. Unlike these turnover markers, a panel of bone cell regulatory proteins exhibited divergent age-related changes in marrow versus peripheral blood, suggesting that their circulating levels may not reflect local levels to which osteoclasts and osteoblasts are directly exposed. Published by Elsevier Inc.

  15. LRP5 and bone mass regulation: Where are we now?

    Science.gov (United States)

    Johnson, Mark L

    2012-01-01

    The discovery of causal mutations in the low-density lipoprotein receptor-related protein 5 (LRP5) gene underlying conditions of altered bone mass ushered in a new era in bone research. Since those original publications, the role of Lrp5 and the Wnt/β-catenin signaling pathway controlled by Lrp5 and its homologs, Lrp6 and Lrp4, in bone mass regulation has been an intense area of investigation. Studies to date have implicated this pathway in skeletal development, osteoblast differentiation and proliferation, osteoblast/osteocyte apoptosis, regulation of the balance between osteogenesis-chondrogenesis-adipogenesis, regulation of osteoclastogenesis and the response of bone to mechanical loading. Interestingly, the data from knockout and transgenic mice involving Lrp4/5/6 and/or their regulators, as well as β-catenin signaling pathway components, and in vitro studies have sometimes yielded conflicting results. Adding to the complexity of the system are the studies that suggested Lrp5 regulated bone mass through a gut-bone endocrine signaling system involving Lrp5 mediated control of gut serotonin synthesis. However, recent studies have called this into question and so this provocative concept remains an open question. Clearly, the manipulation of Lrp5/Wnt/β-catenin pathway presents as a major target for drug development to treat diseases of low bone mass such as osteoporosis and these new therapies are in full progress. At present, although it is clear that Lrp5 has a role in bone mass regulation, much of the details remain to be elucidated and this is a major and exciting challenge for future studies.

  16. Rhus javanica Gall Extract Inhibits the Differentiation of Bone Marrow-Derived Osteoclasts and Ovariectomy-Induced Bone Loss

    Directory of Open Access Journals (Sweden)

    Tae-Ho Kim

    2016-01-01

    Full Text Available Inhibition of osteoclast differentiation and bone resorption is a therapeutic strategy for the management of postmenopausal bone loss. This study investigated the effects of Rhus javanica (R. javanica extracts on bone marrow cultures to develop agents from natural sources that may prevent osteoclastogenesis. Extracts of R. javanica (eGr cocoons spun by Rhus javanica (Bell. Baker inhibited the osteoclast differentiation and bone resorption. The effects of aqueous extract (aeGr or 100% ethanolic extract (eeGr on ovariectomy- (OVX- induced bone loss were investigated by various biochemical assays. Furthermore, microcomputed tomography (µCT was performed to study bone remodeling. Oral administration of eGr (30 mg or 100 mg/kg/day for 6 weeks augmented the inhibition of femoral bone mineral density (BMD, bone mineral content (BMC, and other factors involved in bone remodeling when compared to OVX controls. Additionally, eGr slightly decreased bone turnover markers that were increased by OVX. Therefore, it may be suggested that the protective effects of eGr could have originated from the suppression of OVX-induced increase in bone turnover. Collectively, the findings of this study indicate that eGr has potential to activate bone remodeling by inhibiting osteoclast differentiation and bone loss.

  17. Effects of conjugated linoleic acid and exercise on bone mass in young male Balb/C mice

    Directory of Open Access Journals (Sweden)

    O'Shea Marianne

    2006-03-01

    Full Text Available Abstract There is an increase in obesity among the population of industrialized countries, and dietary supplementation with Conjugated Linoleic Acid (CLA has been reported to lower body fat mass. However, weight loss is generally associated with negative effects on bone mass, but CLA is reported to have beneficial effects on bone. Furthermore, another factor that is well established to have a beneficial effect on bone is exercise (EX. However, a combination therapy of CLA and EX on bone health has not been studied. In this paper, we report the beneficial effects of CLA and EX on bone, in four different groups of Balb-C young, male mice. There were 4 groups in our study: 1. Safflower oil (SFO sedentary (SED; 2. SFO EX; 3. CLA SED; 4. CLA EX. Two months old mice, under their respective treatment regimens were followed for 14 weeks. Mice were scanned in vivo using a DEXA scanner before and after treatment. At the end of the treatment period, the animals were sacrificed, the left tibia was removed and scanned using peripheral quantitative computerized tomography (pQCT. The results showed that although CLA decreased gain in body weight by 35%, it however increased bone mass by both reducing bone resorption and increasing bone formation. EX also decreased gain in body weight by 21% and increased bone mass; but a combination of CLA and EX, however, did not show any further increase in bone mass. In conclusion, CLA increases bone mass in both cancellous and cortical bones, and the effects of CLA on bone is not further improved by EX in pure cortical bone of young male mice.

  18. SWIMMING ENHANCES BONE MASS ACQUISITION IN GROWING FEMALE RATS

    Directory of Open Access Journals (Sweden)

    Joanne McVeigh

    2010-12-01

    Full Text Available Growing bones are most responsive to mechanical loading. We investigated bone mass acquisition patterns following a swimming or running exercise intervention of equal duration, in growing rats. We compared changes in bone mineral properties in female Sprague Dawley rats that were divided into three groups: sedentary controls (n = 10, runners (n = 8 and swimmers (n = 11. Runners and swimmers underwent a six week intervention, exercising five days per week, 30min per day. Running rats ran on an inclined treadmill at 0.33 m.s-1, while swimming rats swam in 25oC water. Dual energy X-ray absorptiometry scans measuring bone mineral content (BMC, bone mineral density (BMD and bone area at the femur, lumbar spine and whole body were recorded for all rats before and after the six week intervention. Bone and serum calcium and plasma parathyroid hormone (PTH concentrations were measured at the end of the 6 weeks. Swimming rats had greater BMC and bone area changes at the femur and lumbar spine (p < 0.05 than the running rats and a greater whole body BMC and bone area to that of control rats (p < 0.05. There were no differences in bone gain between running and sedentary control rats. There was no significant difference in serum or bone calcium or PTH concentrations between the groups of rats. A swimming intervention is able to produce greater beneficial effects on the rat skeleton than no exercise at all, suggesting that the strains associated with swimming may engender a unique mechanical load on the bone

  19. Annual bone loss and success rates of dental implants based on radiographic measurements

    NARCIS (Netherlands)

    Geraets, W.; Zhang, L.; Liu, Y.; Wismeijer, D.

    2014-01-01

    Objectives: Bone loss around dental implants is generally measured by monitoring changes in marginal bone level using radiographs. After the first year of implantation, an implant should have <0.2 mm annual loss of marginal bone level to satisfy the criteria of success. However, the process of

  20. Sheep model for osteoporosis: The effects of peripheral hormone therapy on centrally induced systemic bone loss in an osteoporotic sheep model.

    Science.gov (United States)

    Oheim, Ralf; Simon, Maciej J K; Steiner, Malte; Vettorazzi, Eik; Barvencik, Florian; Ignatius, Anita; Amling, Michael; Clarke, Iain J; Pogoda, Pia; Beil, F Timo

    2017-04-01

    Hypothalamic-pituitary disconnection (HPD) leads to low bone turnover followed by bone loss and reduced biomechanical properties in sheep. To investigate the role of peripheral hormones in this centrally induced systemic bone loss model, we planned a hormone replacement experiment. Therefore, estrogen (OHE), thyroxin (OHT) or a combination of both (OHTE) was substituted in ovariectomized HPD sheep, as both hormones are decreased in HPD sheep and are known to have a significant but yet not fully understood impact on bone metabolism. Bone turnover and structural parameters were analyzed in comparison to different control groups - untreated sheep (C), ovariectomized (O) and ovariectomized+HPD sheep (OH). We performed histomorphometric and HR-pQCT analyses nine months after the HPD procedure, as well as biomechanical testing of all ewes studied. In HPD sheep (OH) the low bone turnover led to a significant bone loss. Treatment with thyroxin alone (OHT) mainly increased bone resorption, leading to a further reduction in bone volume. In contrast, the treatment with estrogen alone (OHE) and the combined treatment with estrogen and thyroxin (OHTE) prevented HPD-induced bone loss completely. In conclusion, peripheral hormone substitution was able to prevent HPD-induced low-turnover osteoporosis in sheep. But only the treatment with estrogen alone or in combination with thyroxin was able to completely preserve bone mass and structure. These findings demonstrate the importance of peripheral hormones for a balanced bone remodeling and a physiological bone turnover. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Lack of influence of simple premenopausal hysterectomy on bone mass and bone metabolism

    DEFF Research Database (Denmark)

    Ravn, Pernille; Lind, C; Nilas, L

    1995-01-01

    OBJECTIVE: Our purpose was to investigate the influence of premenopausal hysterectomy on bone mass. STUDY DESIGN: A cross-sectional study was performed on 69 women who had premenopausal hysterectomy and 427 women with natural menopause 50 to 59 years old. Bone mineral density was measured...... in the distal forearm by single-energy x-ray absorptiometry. Body composition and bone mineral density in the anteroposterior spine, proximal femur, and total body was measured by dual-energy x-ray absorptiometry. Bone turnover was determined by plasma osteocalcin, serum alkaline phosphatase, and fasting...... urinary calcium corrected for creatinine excretion. RESULTS: Women who had undergone premenopausal hysterectomy had similar bone mineral densities compared with women with an intact uterus in all compartments, apart from a 6% to 11% higher bone mineral density (p

  2. Thirteen-lined ground squirrels (Ictidomys tridecemlineatus) show microstructural bone loss during hibernation but preserve bone macrostructural geometry and strength.

    Science.gov (United States)

    McGee-Lawrence, Meghan E; Stoll, Danielle M; Mantila, Emily R; Fahrner, Bryna K; Carey, Hannah V; Donahue, Seth W

    2011-04-15

    Lack of activity causes bone loss In most animals. Hibernating bears have physiological processes to prevent cortical and trabecular bone loss associated with reduced physical activity, but different mechanisms of torpor among hibernating species may lead to differences in skeletal responses to hibernation. There are conflicting reports regarding whether small mammals experience bone loss during hibernation. To investigate this phenomenon, we measured cortical and trabecular bone properties in physically active and hibernating juvenile and adult 13-lined ground squirrels (Ictidomys tridecemlineatus, previous genus name Spermophilus). Cortical bone geometry, strength and mineral content were similar in hibernating compared with active squirrels, suggesting that hibernation did not cause macrostructural cortical bone loss. Osteocyte lacunar size increased (linear regression, P=0.001) over the course of hibernation in juvenile squirrels, which may indicate an osteocytic role in mineral homeostasis during hibernation. Osteocyte lacunar density and porosity were greater (+44 and +59%, respectively; Phibernating compared with active squirrels, which may reflect a decrease in osteoblastic activity (per cell) during hibernation. Trabecular bone volume fraction in the proximal tibia was decreased (-20%; P=0.028) in hibernating compared with physically active adult squirrels, but was not different between hibernating and active juvenile squirrels. Taken together, these data suggest that 13-lined ground squirrels may be unable to prevent microstructural losses of cortical and trabecular bone during hibernation, but importantly may possess a biological mechanism to preserve cortical bone macrostructure and strength during hibernation, thus preventing an increased risk of bone fracture during remobilization in the spring.

  3. Increased activity of osteocyte autophagy in ovariectomized rats and its correlation with oxidative stress status and bone loss

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Yuehua, E-mail: yuesjtu@126.com; Zheng, Xinfeng, E-mail: zxf272@126.com; Li, Bo, E-mail: libo@126.com; Jiang, Shengdan, E-mail: jiangsd@126.com; Jiang, Leisheng, E-mail: leisheng_jiang@126.com

    2014-08-15

    Highlights: • Examine autophagy level in the proximal tibia of ovariectomized rats. • Investigate whether autophagy level is associated with bone loss. • Investigate whether autophagy level is associated with oxidative stress status. - Abstract: Objectives: The objectives of the present study were to investigate ovariectomy on autophagy level in the bone and to examine whether autophagy level is associated with bone loss and oxidative stress status. Methods: 36 female Sprague–Dawley rats were randomly divided into sham-operated (Sham), and ovariectomized (OVX) rats treated either with vehicle or 17-β-estradiol. At the end of the six-week treatment, bone mineral density (BMD) and bone micro-architecture in proximal tibias were assessed by micro-CT. Serum 17β-estradiol (E2) level were measured. Total antioxidant capacity (T-AOC), superoxide dismutase (SOD) activity, catalase (CAT) activity in proximal tibia was also determined. The osteocyte autophagy in proximal tibias was detected respectively by Transmission Electron Microscopy (TEM), immunofluorescent histochemistry (IH), realtime-PCR and Western blot. In addition, the spearman correlation between bone mass, oxidative stress status, serum E2 and autophagy were analyzed. Results: Ovariectomy increased Atg5, LC3, and Beclin1 mRNA and proteins expressions while decreased p62 expression. Ovariectomy also declined the activities of T-AOC, CAT, and SOD. Treatment with E2 prevented the reduction in bone mass as well as restored the autophagy level. Furthermore, LC3-II expression was inversely correlated with T-AOC, CAT, and SOD activities. A significant inverse correlation between LC3-II expression and BV/TV, Tb.N, BMD in proximal tibias was found. Conclusions: Ovariectomy induced oxidative stress, autophagy and bone loss. Autophagy of osteocyte was inversely correlated with oxidative stress status and bone loss.

  4. The variable mass loss of the AGB star

    NARCIS (Netherlands)

    Decin, L.K.E.; Hony, S.; de Koter, A.; Molenberghs, G.; Dehaes, S.; Markwick-Kemper, F.

    2007-01-01

    Context: Low and intermediate mass stars lose a significant fraction of their mass through a dust-driven wind during the Asymptotic Giant Branch (AGB) phase. Recent studies show that winds from late-type stars are far from being smooth. Mass-loss variations occur on different time scales, from years

  5. The effects of different intensities of exercise and active vitamin D on mouse bone mass and bone strength.

    Science.gov (United States)

    Zhang, Lingli; Chen, Xi; Wu, Juanni; Yuan, Yu; Guo, Jianmin; Biswas, Soma; Li, Baojie; Zou, Jun

    2017-05-01

    Physical exercise is beneficial to bone health. However, little is known how different intensities of exercise affect bone mass and strength. In the present study, we used young mice to study the effects of different intensities of exercise on bone mass and bone strength in comparison to pharmacological doses of active vitamin D (calcitriol). We found that only the medium level of exercise tested showed a positive effect on bone mineral density, trabecular bone volume, and bone strength, which are attributable to a decrease in bone resorption and an increase in bone formation, with the latter being accompanied by an increase in the number of osteogenic mesenchymal stem cells in the bone marrow. Calcitriol increases bone volume and bone strength, yet the combination of calcitriol and medium-intensity exercise did not further improve bone mass or strength. Moreover, calcitriol also showed some protective effect on the bone in mice with high levels of exercise. These results indicate that exercise at medium intensity increases bone mass and strength via affecting both bone formation and resorption and that its beneficial effects on bone mass cannot be further improved by calcitriol.

  6. Modulation of osteoblast differentiation and bone mass by 5-HT2A receptor signaling in mice.

    Science.gov (United States)

    Tanaka, Kenjiro; Hirai, Takao; Ishibashi, Yukiko; Izumo, Nobuo; Togari, Akifumi

    2015-09-05

    Recent studies reported that serotonin (5-hydroxytryptamine, 5-HT) may be an endogenous paracrine and/or autocrine factor that is used for intercellular communication in bone cells and between multiple organs regulating bone homeostasis. In the present study, we showed that the administration of MDL11939, a selective 5-HT2A receptor antagonist, reduced bone mass in mice. The loss of bone mass in MDL11939-treated mice was associated with impaired bone formation in vivo, as demonstrated by the lower expression of osterix (Osx) and osteocalcin than that in vehicle-treated mice. On the other hand, no significant differences were observed in osteoclast numbers between MDL11939- and vehicle-treated mice. The pharmacological blockade of 5-HT2A receptor signaling significantly decreased alkaline phosphatase activity in osteoblastic cells. In addition, the knockdown of the 5-HT2A receptor by a siRNA treatment decreased Osx, but not Runx2 gene expression in MC3T3-E1 cells. These results suggest that 5-HT2A receptor signaling mediated bone mass by regulating osteoblast differentiation. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Impact of marked weight loss induced by bariatric surgery on bone mineral density and remodeling

    Directory of Open Access Journals (Sweden)

    F.A. Pereira

    2007-04-01

    Full Text Available Data about the impact of bariatric surgery (BS and subsequent weight loss on bone are limited. The objective of the present study was to determine bone mineral density (BMD, bone remodeling metabolites and hormones that influence bone trophism in premenopausal women submitted to BS 9.8 months, on average, before the study (OGg, N = 16. The data were compared to those obtained for women of normal weight (CG, N = 11 and for obese women (OG, N = 12. Eight patients in each group were monitored for one year, with the determination of BMD, of serum calcium, phosphorus, magnesium, parathyroid hormone, 25-hydroxyvitamin D, insulin-like growth factor-I (IGF-I and osteocalcin, and of urinary calcium and deoxypyridinoline. The biochemical determinations were repeated every three months in the longitudinal study and BMD was measured at the end of the study. Parathyroid hormone levels were similar in the three groups. IGF-I levels (CG = 332 ± 62 vs OG = 230 ± 37 vs OGg = 128 ± 19 ng/mL were significantly lower in the operated patients compared to the non-operated obese women. Only OGg patients presented a significant fall in BMD of 6.2% at L1-L4, of 10.2% in the femoral neck, and of 5.1% in the forearm. These results suggest that the weight loss induced by BS is associated with a significant loss of bone mass even at sites that are not influenced by weight overload, with hormonal factors such as IGF-I being associated with this process.

  8. Alpha-1 antitrypsin gene therapy prevented bone loss in ovariectomy induced osteoporosis mouse model

    Science.gov (United States)

    Osteoporosis is a major healthcare burden affecting mostly postmenopausal women characterized by compromised bone strength and increased risk of fragility fracture. Although pathogenesis of this disease is complex, elevated proinflammatory cytokine production is clearly involved in bone loss at meno...

  9. Donepezil prevents RANK-induced bone loss via inhibition of osteoclast differentiation by downregulating acetylcholinesterase

    Directory of Open Access Journals (Sweden)

    Tsuyoshi Sato

    2015-09-01

    Conclusions: AChE promotes osteoclast differentiation in vitro. Donepezil inhibits osteoclast function in vitro and prevents bone loss by suppressing bone resorption in vivo, suggesting the possibility that donepezil reduces fracture risk in patients with Alzheimer's disease.

  10. Bone mass and mineral metabolism alterations in adult celiac disease: pathophysiology and clinical approach.

    Science.gov (United States)

    Di Stefano, Michele; Mengoli, Caterina; Bergonzi, Manuela; Corazza, Gino Roberto

    2013-11-22

    Osteoporosis affects many patients with celiac disease (CD), representing the consequence of calcium malabsorption and persistent activation of mucosal inflammation. A slight increase of fracture risk is evident in this condition, particularly in those with overt malabsorption and in postmenopausal state. The adoption of a correct gluten-free diet (GFD) improves bone derangement, but is not able to normalize bone mass in all the patients. Biomarkers effective in the prediction of bone response to gluten-free diet are not yet available and the indications of guidelines are still imperfect and debated. In this review, the pathophysiology of bone loss is correlated to clinical aspects, defining an alternative proposal of management for this condition.

  11. Bone Mass and Mineral Metabolism Alterations in Adult Celiac Disease: Pathophysiology and Clinical Approach

    Directory of Open Access Journals (Sweden)

    Michele Di Stefano

    2013-11-01

    Full Text Available Osteoporosis affects many patients with celiac disease (CD, representing the consequence of calcium malabsorption and persistent activation of mucosal inflammation. A slight increase of fracture risk is evident in this condition, particularly in those with overt malabsorption and in postmenopausal state. The adoption of a correct gluten-free diet (GFD improves bone derangement, but is not able to normalize bone mass in all the patients. Biomarkers effective in the prediction of bone response to gluten-free diet are not yet available and the indications of guidelines are still imperfect and debated. In this review, the pathophysiology of bone loss is correlated to clinical aspects, defining an alternative proposal of management for this condition.

  12. Candidate salivary biomarkers associated with alveolar bone loss: cross-sectional and in vitro studies

    OpenAIRE

    Ng, Patricia Yen Bee; Donley, Maureen; Hausmann, Ernest; Hutson, Alan D.; Rossomando, Edward F.; Scannapieco, Frank A.

    2007-01-01

    This cross-sectional study evaluated the association between radiographic evidence of alveolar bone loss and the concentration of host-derived bone resorptive factors (interleukin-1 beta, tumor necrosis factor-alpha, interleukin-6, prostaglandin-E2), and markers of bone turnover [pyridinoline cross-linked carboxyterminal telopeptide of type I collagen (ICTP), osteocalcin, osteonectin] in stimulated human whole saliva collected from 110 untreated dental patients. Alveolar bone loss scores for ...

  13. Effect of Probiotics Supplementation on Bone Mineral Content and Bone Mass Density

    Directory of Open Access Journals (Sweden)

    Kolsoom Parvaneh

    2014-01-01

    Full Text Available A few studies in animals and a study in humans showed a positive effect of probiotic on bone metabolism and bone mass density. Most of the investigated bacteria were Lactobacillus and Bifidobacterium . The positive results of the probiotics were supported by the high content of dietary calcium and the high amounts of supplemented probiotics. Some of the principal mechanisms include (1 increasing mineral solubility due to production of short chain fatty acids; (2 producing phytase enzyme by bacteria to overcome the effect of mineral depressed by phytate; (3 reducing intestinal inflammation followed by increasing bone mass density; (4 hydrolysing glycoside bond food in the intestines by Lactobacillus and Bifidobacteria. These mechanisms lead to increase bioavailability of the minerals. In conclusion, probiotics showed potential effects on bone metabolism through different mechanisms with outstanding results in the animal model. The results also showed that postmenopausal women who suffered from low bone mass density are potential targets to consume probiotics for increasing mineral bioavailability including calcium and consequently increasing bone mass density.

  14. Osteoprotegerin is an effective countermeasure for spaceflight-induced bone loss in mice.

    Science.gov (United States)

    Lloyd, Shane A; Morony, Sean E; Ferguson, Virginia L; Simske, Steven J; Stodieck, Louis S; Warmington, Kelly S; Livingston, Eric W; Lacey, David L; Kostenuik, Paul J; Bateman, Ted A

    2015-12-01

    Bone loss associated with microgravity exposure poses a significant barrier to long-duration spaceflight. Osteoprotegerin-Fc (OPG-Fc) is a receptor activator of nuclear factor kappa-B ligand (RANKL) inhibitor that causes sustained inhibition of bone resorption after a single subcutaneous injection. We tested the ability of OPG-Fc to preserve bone mass during 12 days of spaceflight (SF). 64-day-old female C57BL/6J mice (n=12/group) were injected subcutaneously with OPG-Fc (20mg/kg) or an inert vehicle (VEH), 24h prior to launch. Ground control (GC) mice (VEH or OPG-Fc) were maintained under environmental conditions that mimicked those in the space shuttle middeck. Age-matched baseline (BL) controls were sacrificed at launch. GC/VEH, but not SF/VEH mice, gained tibia BMD and trabecular volume fraction (BV/TV) during the mission (P<0.05 vs. BL). SF/VEH mice had lower BV/TV vs. GC/VEH mice, while SF/OPG-Fc mice had greater BV/TV than SF/VEH or GC/VEH. SF reduced femur elastic and maximum strength in VEH mice, with OPG-Fc increasing elastic strength in SF mice. Serum TRAP5b was elevated in SF/VEH mice vs. GC/VEH mice. Conversely, SF/OPG-Fc mice had lower TRAP5b levels, suggesting that OPG-Fc preserved bone during spaceflight via inhibition of osteoclast-mediated bone resorption. Decreased bone formation also contributed to the observed osteopenia, based on the reduced femur periosteal bone formation rate and serum osteocalcin level. Overall, these observations suggest that the beneficial effects of OPG-Fc during SF are primarily due to dramatic and sustained suppression of bone resorption. In growing mice, this effect appears to compensate for the SF-related inhibition of bone formation, while preventing any SF-related increase in bone resorption. We have demonstrated that the young mouse is an appropriate new model for SF-induced osteopenia, and that a single pre-flight treatment with OPG-Fc can effectively prevent the deleterious effects of SF on mouse bone. Copyright

  15. LRP5 gene polymorphisms predict bone mass and incident fractures in elderly Australian women.

    Science.gov (United States)

    Bollerslev, J; Wilson, S G; Dick, I M; Islam, F M A; Ueland, T; Palmer, L; Devine, A; Prince, R L

    2005-04-01

    Postmenopausal osteoporosis and bone mass are influenced by multiple factors including genetic variation. The importance of LDL receptor-related protein 5 (LRP5) for the regulation of bone mass has recently been established, where loss of function mutations is followed by severe osteoporosis and gain of function is related to increased bone mass. The aim of this study was to evaluate the role of polymorphisms in the LRP5 gene in regulating bone mass and influencing prospective fracture frequency in a well-described, large cohort of normal, ambulatory Australian women. A total of 1301 women were genotyped for seven different single nucleotide polymorphisms (SNPs) within the LRP5 gene of which five were potentially informative. The effects of these gene polymorphisms on calcaneal quantitative ultrasound measurements (QUS), osteodensitometry of the hip and bone-related biochemistry was examined. One SNP located in exon 15 was found to be associated with fracture rate and bone mineral density. Homozygosity for the less frequent allele of c.3357 A > G was associated with significant reduction in bone mass at most femoral sites. The subjects with the GG genotype, compared to the AA/AG genotypes showed a significant reduction in BUA and total hip, femoral neck and trochanter BMD (1.5% P = 0.032; 2.7% P = 0.047; 3.6% P = 0.008; 3.1% P = 0.050, respectively). In the 5-year follow-up period, 227 subjects experienced a total of 290 radiologically confirmed fractures. The incident fracture rate was significantly increased in subjects homozygous for the GG polymorphism (RR of fracture = 1.61, 95% CI [1.06-2.45], P = 0.027). After adjusting for total hip BMD, the fracture rate was still increased (RR = 1.67 [1.02-2.78], P = 0.045), indicating factors other than bone mass are of importance for bone strength. In conclusion, genetic variation in LRP5 seems to be of importance for regulation of bone mass and osteoporotic fractures.

  16. Conductive hearing loss and bone conduction devices: restored binaural hearing?

    Science.gov (United States)

    Agterberg, Martijn J H; Hol, Myrthe K S; Cremers, Cor W R J; Mylanus, Emmanuel A M; van Opstal, John; Snik, Ad F M

    2011-01-01

    An important aspect of binaural hearing is the proper detection of interaural sound level differences and interaural timing differences. Assessments of binaural hearing were made in patients with acquired unilateral conductive hearing loss (UCHL, n = 11) or congenital UCHL (n = 10) after unilateral application of a bone conduction device (BCD), and in patients with bilateral conductive or mixed hearing loss after bilateral BCD application. Benefit (bilateral versus unilateral listening) was assessed by measuring directional hearing, compensation of the acoustic head shadow, binaural summation and binaural squelch. Measurements were performed after an acclimatization time of at least 10 weeks. Unilateral BCD application was beneficial, but there was less benefit in the patients with congenital UCHL as compared to patients with acquired UCHL. In adults with bilateral hearing loss, bilateral BCD application was clearly beneficial as compared to unilateral BCD application. Binaural summation was present, but binaural squelch could not be proven. To explain the poor results in the patients with congenital UCHL, two factors seemed to be important. First, a critical period in the development of binaural hearing might affect the binaural hearing abilities. Second, crossover stimulation, referring to additional stimulation of the cochlea contralateral to the BCD side, might deteriorate binaural hearing in patients with UCHL. Copyright © 2011 S. Karger AG, Basel.

  17. Rate Equation and Scaling for Fragmentation with Mass Loss

    OpenAIRE

    Edwards, Boyd F.; Cai, M.; Han, H.

    1990-01-01

    A linear rate equation describes fragmentation with continuous and discrete mass loss typified by consumption of porous reactive solids and two-phase heterogeneous solids. For a mass-dependent fragmentation rate xα and a continuous-mass-loss rate εxγ,σ=γ-α-1‘‘recession regime’’ where small particles lose mass continuously without breaking, σ>0 yields a ‘‘fragmentation regime’’ where all particles break, and σ=0 yields scaling for α>0. Shattering for ασ≥0 is runaway fragmentation produci...

  18. Vascularized fibular graft in infected tibial bone loss

    Directory of Open Access Journals (Sweden)

    C Cheriyan Kovoor

    2011-01-01

    Full Text Available Background : The treatment options of bone loss with infections include bone transport with external fixators, vascularized bone grafts, non-vascularized autogenous grafts and vascularized allografts. The research hypothesis was that the graft length and intact ipsilateral fibula influenced hypertrophy and stress fracture. We retrospectively studied the graft hypertrophy in 15 patients, in whom vascularized fibular graft was done for post-traumatic tibial defects with infection. Materials and Methods : 15 male patients with mean age 33.7 years (range 18 - 56 years of post traumatic tibial bone loss were analysed. The mean bony defect was 14.5 cm (range 6.5 - 20 cm. The mean length of the graft was 16.7 cm (range 11.5 - 21 cm. The osteoseptocutaneous flap (bone flap with attached overlying skin flap from the contralateral side was used in all patients except one. The graft was fixed to the recipient bone at both ends by one or two AO cortical screws, supplemented by a monolateral external fixator. A standard postoperative protocol was followed in all patients. The hypertrophy percentage of the vascularized fibular graft was calculated by a modification of the formula described by El-Gammal. The followup period averaged 46.5 months (range 24 - 164 months. The Pearson correlation coefficient (r was worked out, to find the relationship between graft length and hypertrophy. The t-test was performed to find out if there was any significant difference in the graft length of those who had a stress fracture and those who did not and to find out whether there was any significant difference in hypertrophy with and without ipsilateral fibula union. The Chi square test was performed to identify whether there was any association between the stress fracture and the fibula union. Given the small sample size we have not used any statistical analysis to determine the relation between the percentage of the graft hypertrophy and stress fracture. Results : Graft

  19. Bioactive silica nanoparticles reverse age-associated bone loss in mice.

    Science.gov (United States)

    Weitzmann, M Neale; Ha, Shin-Woo; Vikulina, Tatyana; Roser-Page, Susanne; Lee, Jin-Kyu; Beck, George R

    2015-05-01

    We recently reported that in vitro, engineered 50nm spherical silica nanoparticles promote the differentiation and activity of bone building osteoblasts but suppress bone-resorbing osteoclasts. Furthermore, these nanoparticles promote bone accretion in young mice in vivo. We have now investigated the capacity of these nanoparticles to reverse bone loss in aged mice, a model of human senile osteoporosis. Aged mice received nanoparticles weekly and bone mineral density (BMD), bone structure, and bone turnover were quantified. Our data revealed a significant increase in BMD, bone volume, and biochemical markers of bone formation. Biochemical and histological examinations failed to identify any abnormalities caused by nanoparticle administration. Our studies demonstrate that silica nanoparticles effectively blunt and reverse age-associated bone loss in mice by a mechanism involving promotion of bone formation. The data suggest that osteogenic silica nanoparticles may be a safe and effective therapeutic for counteracting age-associated bone loss. Osteoporosis poses a significant problem in the society. Based on their previous in-vitro findings, the authors' group investigated the effects of spherical silica nanoparticles in reversing bone loss in a mouse model of osteoporosis. The results showed that intra-peritoneal injections of silica nanoparticles could increase bone mineral density, with little observed toxic side effects. This novel method may prove important in future therapy for combating osteoporosis. Published by Elsevier Inc.

  20. Thin healthy women have a similar low bone mass to women with anorexia nervosa.

    Science.gov (United States)

    Fernández-García, D; Rodríguez, M; García Alemán, J; García-Almeida, J M; Picón, M J; Fernández-Aranda, F; Tinahones, F J

    2009-09-01

    An association between anorexia nerviosa (AN) and low bone mass has been demonstrated. Bone loss associated with AN involves hormonal and nutritional impairments, though their exact contribution is not clearly established. We compared bone mass in AN patients with women of similar weight with no criteria for AN, and a third group of healthy, normal-weight, age-matched women. The study included forty-eight patients with AN, twenty-two healthy eumenorrhoeic women with low weight (LW group; BMI 18.5 kg/m2 (control group), all of similar age. We measured lean body mass, percentage fat mass, total bone mineral content (BMC) and bone mineral density in lumbar spine (BMD LS) and in total (tBMD). We measured anthropometric parameters, leptin and growth hormone. The control group had greater tBMD and BMD LS than the other groups, with no differences between the AN and LW groups. No differences were found in tBMD, BMD LS and total BMC between the restrictive (n 25) and binge-purge type (n 23) in AN patients. In AN, minimum weight (P = 0.002) and percentage fat mass (P = 0.02) explained BMD LS variation (r2 0.48) and minimum weight (r2 0.42; P = 0.002) for tBMD in stepwise regression analyses. In the LW group, BMI explained BMD LS (r2 0.72; P = 0.01) and tBMD (r2 0.57; P = 0.04). We concluded that patients with AN had similar BMD to healthy thin women. Anthropometric parameters could contribute more significantly than oestrogen deficiency in the achievement of peak bone mass in AN patients.

  1. The Optimal Duration of PTH(1-34) Infusion Is One Hour per Day to Increase Bone Mass in Rats.

    Science.gov (United States)

    Shimizu, Masaru; Noda, Hiroshi; Joyashiki, Eri; Nakagawa, Chie; Asanuma, Kentaro; Hayasaka, Akira; Kato, Motohiro; Nanami, Masahiko; Inada, Masaki; Miyaura, Chisato; Tamura, Tatsuya

    2016-01-01

    Parathyroid hormone (PTH) is a potential medicine for osteoporosis, and subcutaneous (s.c.) PTH treatment enhances bone mass; however, continuous infusion of PTH elicits bone resorption and induces bone loss. To clarify this contradictory phenomenon, we examined bone markers and bone mass in rats to assess the optimal duration of PTH(1-34) infusion. Continuous infusion of PTH at 1 µg/kg/h (Css, steady-state concentration ca. 300 pg/mL) for 1-4 h clearly stimulated the expression both of bone formation-related genes (c-fos, Wnt4, EphrinB2) and of bone resorption-related genes (tnfsf11, tnfsf11b, encoding receptor activator of nuclear factor-kappaB ligand (RANKL), osteoprotegerin (OPG)), but s.c. treatment stimulated these genes only 1-h after the injection. Rats were treated with 1-, 2-, or 4-h infusions of PTH daily using a totally implanted catheter system, and the femoral bone mineral density (BMD) was measured at 4 weeks. The 1-h infusion of PTH significantly stimulated serum bone formation markers (procollagen I N-terminal propeptide (PINP) and osteocalcin) on day 14 and femoral BMD at 2 and 4 weeks, but the 4-h infusion of PTH did not enhance BMD. Since the 4-h infusion increased the levels of both the bone formation markers and a bone resorption marker (urinary C-terminal telopeptide of type 1 collagen (CTx)), the increased bone resorption may predominate over bone formation. The intermittent elevation of plasma PTH to 300 pg/mL for 1-h each day is optimal for increasing bone mass in rats. In osteoporosis therapy in human, using the optimal duration for the clinical dose of PTH may selectively stimulate bone formation.

  2. Relationship of bony trabecular characteristics and age to bone mass

    International Nuclear Information System (INIS)

    Choi, Dong Hoon; Song, Young Han; Yoon, Young Nam; Lee, Wan; Lee, Byung Do

    2006-01-01

    Bony strength is dependent on bone mass and bony structure. So this study was designed to investigate the relationship between the bone mass and bony mass and bony trabecular characteristics. Study subjects were 51 females (average age 68.6 years) and 20 males (average age 66.4 years). Bony mineral density (BMD, grams/cm 2 ) of proximal femur was measured by a dual energy X-ray absorptiometry (DEXA). Regions of interest (ROIs) were selected from the digitized radiographs of proximal femur. A customized computer program processed morphologic operations (MO) of ROIs. 44 skeletal variables of MO were calculated from ROIs on the Ward's triangle and greater trochanter of femur. WHO BMD classes were predicted by MO variables of the same ROI. Classification and Regression Tree analysis was used for calculating weighted kappa values, sensitivity and specificity of MO. The discriminating factors of morphologic operation were branch point, branch point [per cm sq]. Age also played important role in distinguishing osteoporotic classes. The sensitivity of MO at Ward's triangle and Greater Trochanter was 91.8%, 65.6%, respectively. The specificity of MO was 100% at Ward's triangle and Greater Trochanter. Bony trabecular characteristics obtained using radiological bone morphometric analysis seem to be related to bone mass

  3. Single-nucleotide polymorphisms in the P2X7 receptor gene are associated with post-menopausal bone loss and vertebral fractures

    DEFF Research Database (Denmark)

    Rye Jørgensen, Niklas; Husted, Lise Bjerre; Skarratt, Kristen K

    2012-01-01

    to bone mass and fracture incidence in post-menopausal women. A total of 1694 women (aged 45-58) participating in the Danish Osteoporosis Prevention Study were genotyped for 12 functional P2X7 receptor variants. Bone mineral density was determined at baseline and after 10 years. In addition, vertebral...... had increased bone loss. In contrast, the Gln460Arg polymorphism was associated with protection against bone loss. The Ala348Thr polymorphism was associated with a lower vertebral fracture incidence 10 years after menopause. Finally, we developed a risk model, which integrated P2RX7 genotypes. Using...

  4. Mineralization defects in cementum and craniofacial bone from loss of bone sialoprotein

    Science.gov (United States)

    Foster, B.L.; Ao, M.; Willoughby, C.; Soenjaya, Y.; Holm, E.; Lukashova, L.; Tran, A. B.; Wimer, H.F.; Zerfas, P.M.; Nociti, F.H.; Kantovitz, K.R.; Quan, B.D.; Sone, E.D.; Goldberg, H.A.; Somerman, M.J.

    2015-01-01

    Bone sialoprotein (BSP) is a multifunctional extracellular matrix protein found in mineralized tissues, including bone, cartilage, tooth root cementum (both acellular and cellular types), and dentin. In order to define the role BSP plays in the process of biomineralization of these tissues, we analyzed cementogenesis, dentinogenesis, and osteogenesis (intramembranous and endochondral) in craniofacial bone in Bsp null mice and wild-type (WT) controls over a developmental period (1-60 days post natal; dpn) by histology, immunohistochemistry, undecalcified histochemistry, microcomputed tomography (microCT), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and quantitative PCR (qPCR). Regions of intramembranous ossification in the alveolus, mandible, and calvaria presented delayed mineralization and osteoid accumulation, assessed by von Kossa and Goldner's trichrome stains at 1 and 14 dpn. Moreover, Bsp−/− mice featured increased cranial suture size at the early time point, 1 dpn. Immunostaining and PCR demonstrated that osteoblast markers, osterix, alkaline phosphatase, and osteopontin were unchanged in Bsp null mandibles compared to WT. Bsp−/− mouse molars featured a lack of functional acellular cementum formation by histology, SEM, and TEM, and subsequent loss of Sharpey's collagen fiber insertion into the tooth root structure. Bsp−/− mouse alveolar and mandibular bone featured equivalent or fewer osteoclasts at early ages (1 and 14 dpn), however, increased RANKL immunostaining and mRNA, and significantly increased number of osteoclast-like cells (2-5 fold) were found at later ages (26 and 60 dpn), corresponding to periodontal breakdown and severe alveolar bone resorption observed following molar teeth entering occlusion. Dentin formation was unperturbed in Bsp−/− mouse molars, with no delay in mineralization, no alteration in dentin dimensions, and no differences in odontoblast markers analyzed. No defects were identified

  5. Marginal bone loss as success criterion in implant dentistry: beyond 2 mm.

    Science.gov (United States)

    Galindo-Moreno, Pablo; León-Cano, Ana; Ortega-Oller, Inmaculada; Monje, Alberto; O'Valle, Francisco; Catena, Andrés

    2015-04-01

    The aim of this study was to analyze marginal bone loss (MBL) rates around implants to establish the difference between physiological bone loss and bone loss due to peri-implantitis. Five hundred and eight implants were placed in the posterior maxilla in 208 patients. Data were gathered on age, gender, bone substratum (grafted or pristine), prosthetic connection, smoking and alcohol habits, and previous periodontitis. MBL was radiographically analyzed in three time frames (5 months post-surgery and at 6 and 18 months post-loading). Nonparametric receiver operating curve (ROC) analysis and mixed linear model analysis were used to determine whether implants could be classified as high or low bone loser type (BLT) and to establish the influence of this factor on MBL rates. Marginal bone loss rates were significantly affected by BLT, connection type, bone substratum, and smoking. Bone loss rates at 18 months were associated with initial bone loss rates: 96% of implants with an MBL of >2 mm at 18 months had lost 0.44 mm or more at 6 months post-loading. Implants with increased MBL rates at early stages (healing and immediate post-loading periods) are likely to reach MBL values that compromise their final outcome. Initial (healing, immediate post-loading) MBL rates around an implant of more than 0.44 mm/year are an indication of peri-implant bone loss progression. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  6. Higher bone mass in prepubertal and peripubertal female footballers.

    Science.gov (United States)

    Plaza-Carmona, M; Vicente-Rodríguez, G; Gómez-Cabello, A; Martín-García, M; Sánchez-Sánchez, J; Gallardo, L; Ara, I

    2016-10-01

    The main aim of this study was to compare the bone mass of female football players with controls of different pubertal stages. Sixty five girls aged 8-14 years (10.14 ± 0.1, Tanner stages I-IV) participated in the study. Twenty participants were prepubertal (10 prepubertal control) and 45 peripubertal (15 peripubertal control). All footballers trained two days per week while the control group did not perform regular physical activity outside of school. Body composition was assessed by Dual-energy X-ray absorptiometry. Analysis of covariance was performed to evaluate differences in lean and bone masses. Significant differences in lower-body extremities lean mass (LLM) between peripubertal groups were found (P pubertal spurt.

  7. Loss of PiT-2 results in abnormal bone development and decreased bone mineral density and length in mice.

    Science.gov (United States)

    Yamada, Shunsuke; Wallingford, Mary C; Borgeia, Suhaib; Cox, Timothy C; Giachelli, Cecilia M

    2018-01-01

    Normal bone mineralization requires phosphate oversaturation in bone matrix vesicles, as well as normal regulation of phosphate metabolism via the interplay among bone, intestine, and kidney. In turn, derangement of phosphate metabolism greatly affects bone function and structure. The type III sodium-dependent phosphate transporters, PiT-1 and PiT-2, are believed to be important in tissue phosphate metabolism and physiological bone formation, but their requirement and molecular roles in bone remain poorly investigated. In order to decipher the role of PiT-2 in bone, we examined normal bone development, growth, and mineralization in global PiT-2 homozygous knockout mice. PiT-2 deficiency resulted in reduced vertebral column, femur, and tibia length as well as mandibular dimensions. Micro-computed tomography analysis revealed that bone mineral density in the mandible, femur, and tibia were decreased, indicating that maintenance of bone function and structure is impaired in both craniofacial and long bones of PiT-2 deficient mice. Both cortical and trabecular thickness and mineral density were reduced in PiT-2 homozygous knockout mice compared with wild-type mice. These results suggest that PiT-2 is involved in normal bone development and growth and plays roles in cortical and trabecular bone metabolism feasibly by regulating local phosphate transport and mineralization processes in the bone. Further studies that evaluate bone cell-specific loss of PiT-2 are now warranted and may yield insight into complex mechanisms of bone development and growth, leading to identification of new therapeutic options for patients with bone diseases. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Peripubertal female athletes in high-impact sports show improved bone mass acquisition and bone geometry.

    Science.gov (United States)

    Maïmoun, Laurent; Coste, Olivier; Philibert, Pascal; Briot, Karine; Mura, Thibault; Galtier, Florence; Mariano-Goulart, Denis; Paris, Françoise; Sultan, Charles

    2013-08-01

    Intensive physical training may have a sport-dependent effect on bone mass acquisition. This cross-sectional study evaluated bone mass acquisition in girls practicing sports that put different mechanical loads on bone. Eighty girls from 10.7 to 18.0 years old (mean 13.83 ± 1.97) were recruited: 20 artistic gymnasts (AG; high-impact activity), 20 rhythmic gymnasts (RG; medium-impact activity), 20 swimmers (SW, no-impact activity), and 20 age-matched controls (CON; leisure physical activity gymnast groups compared with SW and CON. In RG only, endocortical diameter and width were reduced, while Z was only increased in AG compared with SW and CON. Reduced bone remodeling was observed in RG compared with AG only when groups were subdivided according to menarcheal status. All groups showed similar OPG concentrations, while RANKL concentrations increased with age and were decreased in SW. High-impact activity clearly had a favorable effect on aBMD and bone geometry during the growth period, although the bone health benefits seem to be more marked after menarche. Copyright © 2013 Elsevier Inc. All rights reserved.

  9. Grizzly bears (Ursus arctos horribilis) and black bears (Ursus americanus) prevent trabecular bone loss during disuse (hibernation)

    OpenAIRE

    McGee-Lawrence, Meghan E.; Wojda, Samantha J.; Barlow, Lindsay N.; Drummer, Thomas D.; Castillo, Alesha B.; Kennedy, Oran; Condon, Keith W.; Auger, Janene; Black, Hal L.; Nelson, O. Lynne; Robbins, Charles T.; Donahue, Seth W.

    2009-01-01

    Disuse typically causes an imbalance in bone formation and bone resorption, leading to losses of cortical and trabecular bone. In contrast, bears maintain balanced intracortical remodeling and prevent cortical bone loss during disuse (hibernation). Trabecular bone, however, is more detrimentally affected than cortical bone in other animal models of disuse. Here we investigated the effects of hibernation on bone remodeling, architectural properties, and mineral density of grizzly bear (Ursus a...

  10. Impact of annual bone loss and different bone quality on dental implant success - A finite element study.

    Science.gov (United States)

    Linetskiy, Igor; Demenko, Vladyslav; Linetska, Larysa; Yefremov, Oleg

    2017-12-01

    For dental implant success, experimentally established thresholds should limit bone stresses and strains. From these metrics, the ultimate functional load, which determines the implant load-carrying capacity, can be calculated. Obviously, its decrease due to bone loss shortens implant service life. A comparison of how bone loss affects the ultimate functional loads of various implants can provide the clinician with meaningful feedback concerning the suitability and longevity of implants. The aim of this study is to evaluate the lifetime of different dental implants placed in I-IV bone types on the basis of a comparison of their ultimate functional loads with consideration of the bone loss factor. Von Mises stress and first principal strain distributions in bone-implant interface were studied and ultimate functional loads were calculated. Models of I-IV bone types were designed. 3.3 × 8.0 mm (A), 4.1 × 12.0 mm (B) and 4.8 × 14.0 mm (C) implants were analyzed at 10 levels of bone loss. Ultimate functional loads, which generated the ultimate von Mises stress and first principal strain in bone, were computed. For the implants A, B, and C placed in type I bone, ultimate functional load values were above 120.92 N experimental functional load, which corresponded to 10+, 10+, and 10 + years of service with 0.2 mm annual bone loss. For type II bone, the lifetime was 4, 10+, and 10 + years. For type III bone, the lifetime was 4, 5, and 5 years. For type IV bone, first principal strains were initially deleterious for all implants. In oral implantology, bone loss is an essential factor for implant longevity prognosis. While evaluating implant load-carrying capacity, clinicians should take into account the factor of implant longevity decrease. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Preservation and promotion of bone formation in the mandible as a response to a novel calcium-phosphate based biomaterial in mineral deficiency induced low bone mass male versus female rats.

    Science.gov (United States)

    Srinivasan, Kritika; Naula, Diana P; Mijares, Dindo Q; Janal, Malvin N; LeGeros, Racquel Z; Zhang, Yu

    2016-07-01

    Calcium and other trace mineral supplements have previously demonstrated to safely improve bone quality. We hypothesize that our novel calcium-phosphate based biomaterial (SBM) preserves and promotes mandibular bone formation in male and female rats on mineral deficient diet (MD). Sixty Sprague-Dawley rats were randomly assigned to receive one of three diets (n = 10): basic diet (BD), MD or mineral deficient diet with 2% SBM. Rats were sacrificed after 6 months. Micro-computed tomography (µCT) was used to evaluate bone volume and 3D-microarchitecture while microradiography (Faxitron) was used to measure bone mineral density from different sections of the mandible. Results showed that bone quality varied with region, gender and diet. MD reduced bone mineral density (BMD) and volume and increased porosity. SBM preserved BMD and bone mineral content (BMC) in the alveolar bone and condyle in both genders. In the alveolar crest and mandibular body, while preserving more bone in males, SBM also significantly supplemented female bone. Results indicate that mineral deficiency leads to low bone mass in skeletally immature rats, comparatively more in males. Furthermore, SBM administered as a dietary supplement was effective in preventing mandibular bone loss in all subjects. This study suggests that the SBM preparation has potential use in minimizing low peak bone mass induced by mineral deficiency and related bone loss irrespective of gender. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 1622-1632, 2016. © 2016 Wiley Periodicals, Inc.

  12. Major depressive disorder is a risk factor for low bone mass, central obesity, and other medical conditions.

    Science.gov (United States)

    Cizza, Giovanni

    2011-01-01

    Major depressive disorder (MDD) is one of the most common psychiatric illnesses in the adult population. It is often associated with an increased risk of cardiovascular disease. Osteoporosis is also a major public health threat. Multiple studies have reported an association between depression and low bone mineral density, but a causal link between these two conditions is disputed. Here the most important findings of the POWER (Premenopausal, Osteoporosis Women, Alendronate, Depression) Study, a large prospective study of bone turnover in premenopausal women with major depression, are summarized. The endocrine and immune alterations secondary to depression that might affect bone mass, and the possible role of poor lifestyle in the etiology of osteoporosis in subjects with depression, are also reviewed, as is the potential effect of antidepressants on bone loss. It is proposed that depression induces bone loss and osteoporotic fractures, primarily via specific immune and endocrine mechanisms, with poor lifestyle habits as potential contributory factors.

  13. An approach for determining quantitative measures for bone volume and bone mass in the pediatric spina bifida population.

    Science.gov (United States)

    Horenstein, Rachel E; Shefelbine, Sandra J; Mueske, Nicole M; Fisher, Carissa L; Wren, Tishya A L

    2015-08-01

    The pediatric spina bifida population suffers from decreased mobility and recurrent fractures. This study aimed to develop a method for quantifying bone mass along the entire tibia in youth with spina bifida. This will provide information about all potential sites of bone deficiencies. Computed tomography images of the tibia for 257 children (n=80 ambulatory spina bifida, n=10 non-ambulatory spina bifida, n=167 typically developing) were analyzed. Bone area was calculated at regular intervals along the entire tibia length and then weighted by calibrated pixel intensity for density weighted bone area. Integrals of density weighted bone area were used to quantify bone mass in the proximal and distal epiphyses and diaphysis. Group differences were evaluated using analysis of variance. Non-ambulatory children suffer from decreased bone mass in the diaphysis and proximal and distal epiphyses compared to ambulatory and control children (P≤0.001). Ambulatory children with spina bifida showed statistically insignificant differences in bone mass in comparison to typically developing children at these sites (P>0.5). This method provides insight into tibial bone mass distribution in the pediatric spina bifida population by incorporating information along the whole length of the bone, thereby providing more information than dual-energy x-ray absorptiometry and peripheral quantitative computed tomography. This method can be applied to any population to assess bone mass distribution across the length of any long bone. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Greenland Ice Sheet Mass Loss from GRACE Monthly Models

    DEFF Research Database (Denmark)

    Sørensen, Louise Sandberg; Forsberg, René

    2010-01-01

    , as is the case with those estimated from GRACE data. In this chapter we have used a generalized inversion method to estimate the Greenland ice sheet mass change from the monthly global gravity solutions, provided by three different GRACE processing centers; CSR, JPL and GFZ. In order to derive mass change from...... these monthly global gravity models, we first calculate the gravity trend from these. When isolating the gravity trend signal, which is caused by the ice mass change, we first subtract the signal produced by the postglacial rebound (PGR) in Greenland. This is done by a simple method based on the ice history......The Greenland ice sheet is currently experiencing a net mass loss. There are however large discrepancies between the published qualitative mass loss estimates, based on different data sets and methods. There are even large differences between the results based on the same data sources...

  15. Mass loss in M67 giants - Evidence from isochrone fitting

    Science.gov (United States)

    Tripicco, Michael J.; Dorman, Ben; Bell, R. A.

    1993-01-01

    A comparison between the color-magnitude diagram of M67 and a new set of theoretical evolutionary models which include all phases from the unevolved main-sequence through core-helium burning and onto the AGB is presented. The present 5-Gyr solar abundance isochrone is found to yield an excellent fit to the whole of the M67 color-magnitude diagram. A differential technique that compares the gap in color between clump giants and normal red giants, on one hand, with the temperature gap between core He-burning tracks and first-ascent RGB tracks, on the other, strongly indicates that the clump giants in M67 have masses of 0.70 solar mass or less. The extremely large amount of mass loss that is deduced is well in excess of that found for globular cluster stars. Possible resolutions of this problem are that degree of mass loss increases with total stellar mass, or with metallicity.

  16. Loss of bone strength in response to exercise-induced weight loss in obese postmenopausal women: results from a pilot study.

    Science.gov (United States)

    Shea, K L; Gozansky, W S; Sherk, V D; Swibas, T A; Wolfe, P; Scherzinger, A; Stamm, E; Kohrt, W M

    2014-06-01

    Exercise-induced weight loss (WL) can lead to decreased areal bone mineral density (aBMD). It is unknown whether this translates into decreased volumetric BMD (vBMD) or bone strength. The purpose of this pilot study was to determine whether exercise-induced WL results in decreased vBMD and bone strength in postmenopausal women. Fourteen subjects participated in a 4-month endurance exercise WL intervention. A weight stable (WS) control group (n=10) was followed for 4 months. Proximal femur aBMD was measured by DXA. Femoral neck vBMD and estimates of bone strength (cross-sectional moment of inertia (CSMI) and section modulus (SM)) were measured by quantitative CT. Women were 54.6±2.4 years, BMI 32.1±5.9 kg/m(2) and 54.4±2.9 years, BMI 27.9±3.6 kg/m(2) in the WL and WS groups, respectively. The WL group lost 3.0±2.6 kg which was predominately fat mass. There was a significant decrease in SMmax. Changes in CSMImax and total hip aBMD were not significant. Total hip vBMD did not decrease significantly in response to WL. There were no significant changes in the WS group. WL may lead to decreased bone strength before changes in BMD are detected. Further studies are needed to determine whether bone-targeted exercise can preserve bone strength during WL.

  17. Alcohol-induced bone loss is blocked in p47phox -/- mice lacking functional nadph oxidases

    Science.gov (United States)

    Chronic ethanol (EtOH) consumption produces bone loss. Previous data suggest a role for NADPH oxidase enzymes (Nox) since the pan-Nox inhibitor diphenylene iodonium (DPI) blocks EtOH-induced bone loss in rats. The current study utilized mice in which Nox enzymes 1,2,3 and 5 are inactivated as a resu...

  18. Vitamin K supplementation does not prevent bone loss in ovariectomized Norway rats

    Science.gov (United States)

    Despite plausible biological mechanisms, the differential abilities of phylloquinone (PK) and menaquinones (MKn) to prevent bone loss remain controversial. The objective of the current study was to compare the effects of PK, menaquinone-4 (MK-4) and menaquinone-7(MK-7) on the rate of bone loss in o...

  19. Pattern of bone loss in dry Mandibles of individuals who died before ...

    African Journals Online (AJOL)

    Pattern of bone loss in dry Mandibles of individuals who died before 1957. ... The total mean bone loss for all teeth was 2.51 (SD 1.15) with a range of 0.85-5.80. ... Thus susceptibility to periodontal disease is evident in a small proportion of individuals even in populations not exposed to modern diet and formal dental ...

  20. Early Subchondral Bone Loss at Arthritis Onset Predicted Late Arthritis Severity in a Rat Arthritis Model.

    Science.gov (United States)

    Courbon, Guillaume; Cleret, Damien; Linossier, Marie-Thérèse; Vico, Laurence; Marotte, Hubert

    2017-06-01

    Synovitis is usually observed before loss of articular function in rheumatoid arthritis (RA). In addition to the synovium and according to the "Inside-Outside" theory, bone compartment is also involved in RA pathogenesis. Then, we investigated time dependent articular bone loss and prediction of early bone loss to late arthritis severity on the rat adjuvant-induced arthritis (AIA) model. Lewis female rats were longitudinally monitored from arthritis induction (day 0), with early (day 10) and late (day 17) steps. Trabecular and cortical microarchitecture parameters of four ankle bones were assessed by microcomputed tomography. Gene expression was determined at sacrifice. Arthritis occurred at day 10 in AIA rats. At this time, bone erosions were detected on four ankle bones, with cortical porosity increase (+67%) and trabecular alterations including bone volume fraction (BV/TV: -13%), and trabecular thickness decrease. Navicular bone assessment was the most reproducible and sensitive. Furthermore, strong correlations were observed between bone alterations at day 10 and arthritis severity or bone loss at day 17, including predictability of day 10 BV/TV to day 17 articular index (R 2  = 0.76). Finally, gene expression at day 17 confirmed massive osteoclast activation and interestingly provided insights on strong activation of bone formation inhibitor markers at the joint level. In rat AIA, bone loss was already observed at synovitis onset and was predicted late arthritis severity. Our results reinforced the key role of subchondral bone in arthritis pathogenesis, in favour to the "Inside-Outside" theory. Mechanisms of bone loss in rat AIA involved resorption activation and formation inhibition changes. J. Cell. Physiol. 232: 1318-1325, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  1. Final Report: Bone Mass Inheritance: A Project to Identify the Genetic Regulation of Bone Mass; FINAL

    International Nuclear Information System (INIS)

    Recker, Robert R. M.D.

    2002-01-01

    This project was designed to find human chromosomal locations that contain genes regulating peak bone density. It is part of a whole genome search for those loci,each responsible for at least 15% of the variation in the peak adult bone density. We accomplished this with a sib pair design, combined with simultaneous examination of extended kindreds. This project gave partial support of the recruitment which has now been completed. The project will extend into 2003. During the remainder of the project, a whole genome scan will be performed from the entire cohort of 2226 persons who have DNA archived, followed by linkage analysis. This project will meet the scientific objective leading eventually to expanded options for treating the condition that leads to bone thinning osteoporosis, and potential fractures in aging populations

  2. Age- and menopause-related bone loss compromise cortical and trabecular microstructure.

    Science.gov (United States)

    Seeman, Ego

    2013-10-01

    All factors influencing the material composition and structure of bone do so through the final common cellular pathways of modeling and remodeling. During growth, modeling, the formation of new bone in different locations without prior bone resorption, deposits matrix upon the periosteum, enlarging the cross-sectional area of bone. Concurrently, endocortical resorption excavates the medullary canal while remodeling, the resorption and deposition of bone in the same location, assembles cortical osteons, each with their central Haversian canal. The Haversian canals and the connecting Volkmann canals form an intracortical canal network that occupies 30% of the total cortical volume. The remaining 70% is mineralized bone matrix volume. Around midlife, in women, remodeling balance becomes negative; less bone is deposited than it is resorbed by each bone's basic multicellular units (BMUs), and remodeling rate increases; there are more BMUs removing bone upon its intracortical, endocortical, and trabecular surfaces. Canals enlarge and coalesce creating giant pores. Remodeling upon trabeculae removes them, whereas intracortical and endocortical remodeling cavitates and fragments the cortex. Bone loss becomes almost entirely cortical as trabeculae disappear. Remodeling removes more bone from a diminishing total mineralized bone matrix volume so that by old age, total mineralized bone matrix volume is halved; 70% of all bone loss is cortical because 80% of the skeleton is cortical; 30% of the bone loss arises from the 20% of the skeleton that is trabecular. Of all fractures occurring, 80% are nonvertebral and 20% are vertebral. The notion of osteoporosis as a disease of trabecular bone loss and vertebral fractures needs to be revised.

  3. Decreased bone turnover with balanced resorption and formation prevent cortical bone loss during disuse (hibernation) in grizzly bears (Ursus arctos horribilis)

    OpenAIRE

    McGee, Meghan E.; Maki, Aaron J.; Johnson, Steven E.; Lynne Nelson, O.; Robbins, Charles T.; Donahue, Seth W.

    2007-01-01

    Disuse uncouples bone formation from resorption, leading to increased porosity, decreased bone geometrical properties, and decreased bone mineral content which compromises bone mechanical properties and increases fracture risk. However, black bear bone properties are not adversely affected by aging despite annual periods of disuse (i.e., hibernation), which suggests that bears either prevent bone loss during disuse or lose bone and subsequently recover it at a faster rate than other animals. ...

  4. The regulation of iron metabolism by hepcidin contributes to unloading-induced bone loss.

    Science.gov (United States)

    Xu, Zi; Sun, Weijia; Li, Yuheng; Ling, Shukuan; Zhao, Chenyang; Zhong, Guohui; Zhao, Dingsheng; Song, Jinping; Song, Hailin; Li, Jinqiao; You, Linhao; Nie, Guangjun; Chang, Yanzhong; Li, Yingxian

    2017-01-01

    Iron overload inhibits osteoblast function and promotes osteoclastogenesis. Hepcidin plays an important role in this process. The changes in iron content and the regulation of hepcidin under unloading-induced bone loss remain unknown. A hindlimb suspension model was adopted to simulate unloading-induced bone loss in mice. The results showed that iron deposition in both liver and bone was markedly increased in hindlimb unloaded mice, and was accompanied by the upregulation of osteoclast activity and downregulation of osteoblast activity. The iron chelator deferoxamine mesylate (DFO) reduced the iron content in bone and alleviated unloading-induced bone loss. The increased iron content in bone was mainly a result of the upregulation of transferrin receptor 1 (TfR1) and divalent metal transporter 1 with iron response element (DMT1+IRE), rather than changes in the iron transporter ferroportin 1 (FPN1). The hepcidin level in the liver was significantly higher, while the FPN1 level in the duodenum was substantially reduced. However, there were no changes in the FPN1 level in bone tissue. During hindlimb unloading, downregulation of hepcidin by siRNA increased iron uptake in bone and liver, which aggravated unloading-induced bone loss. In summary, these data show that unloading-induced bone loss was orchestrated by iron overload and coupled with the regulation of hepcidin by the liver. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. Probiotic L. reuteri treatment prevents bone loss in a menopausal ovariectomized mouse model.

    Science.gov (United States)

    Britton, Robert A; Irwin, Regina; Quach, Darin; Schaefer, Laura; Zhang, Jing; Lee, Taehyung; Parameswaran, Narayanan; McCabe, Laura R

    2014-11-01

    Estrogen deficiency is a major risk factor for osteoporosis that is associated with bone inflammation and resorption. Half of women over the age of 50 will experience an osteoporosis related fracture in their lifetime, thus novel therapies are needed to combat post-menopausal bone loss. Recent studies suggest an important role for gut-bone signaling pathways and the microbiota in regulating bone health. Given that the bacterium Lactobacillus reuteri ATCC PTA 6475 (L. reuteri) secretes beneficial immunomodulatory factors, we examined if this candidate probiotic could reduce bone loss associated with estrogen deficiency in an ovariectomized (Ovx) mouse menopausal model. Strikingly, L. reuteri treatment significantly protected Ovx mice from bone loss. Osteoclast bone resorption markers and activators (Trap5 and RANKL) as well as osteoclastogenesis are significantly decreased in L. reuteri-treated mice. Consistent with this, L. reuteri suppressed Ovx-induced increases in bone marrow CD4+ T-lymphocytes (which promote osteoclastogenesis) and directly suppressed osteoclastogenesis in vitro. We also identified that L. reuteri treatment modifies microbial communities in the Ovx mouse gut. Together, our studies demonstrate that L. reuteri treatment suppresses bone resorption and loss associated with estrogen deficiency. Thus, L. reuteri treatment may be a straightforward and cost-effective approach to reduce post-menopausal bone loss. © 2014 Wiley Periodicals, Inc.

  6. Oxidized lipids enhance RANKL production by T lymphocytes: implications for lipid-induced bone loss.

    Science.gov (United States)

    Graham, Lucia S; Parhami, Farhad; Tintut, Yin; Kitchen, Christina M R; Demer, Linda L; Effros, Rita B

    2009-11-01

    Osteoporosis is a systemic disease that is associated with increased morbidity, mortality and health care costs. Whereas osteoclasts and osteoblasts are the main regulators of bone homeostasis, recent studies underscore a key role for the immune system, particularly via activation-induced T lymphocyte production of receptor activator of NFkappaB ligand (RANKL). Well-documented as a mediator of T lymphocyte/dendritic cell interactions, RANKL also stimulates the maturation and activation of bone-resorbing osteoclasts. Given that lipid oxidation products mediate inflammatory and metabolic disorders such as osteoporosis and atherosclerosis, and since oxidized lipids affect several T lymphocyte functions, we hypothesized that RANKL production might also be subject to modulation by oxidized lipids. Here, we show that short term exposure of both unstimulated and activated human T lymphocytes to minimally oxidized low density lipoprotein (LDL), but not native LDL, significantly enhances RANKL production and promotes expression of the lectin-like oxidized LDL receptor-1 (LOX-1). The effect, which is also observed with 8-iso-Prostaglandin E2, an inflammatory isoprostane produced by lipid peroxidation, is mediated via the NFkappaB pathway, and involves increased RANKL mRNA expression. The link between oxidized lipids and T lymphocytes is further reinforced by analysis of hyperlipidemic mice, in which bone loss is associated with increased RANKL mRNA in T lymphocytes and elevated RANKL serum levels. Our results suggest a novel pathway by which T lymphocytes contribute to bone changes, namely, via oxidized lipid enhancement of RANKL production. These findings may help elucidate clinical associations between cardiovascular disease and decreased bone mass, and may also lead to new immune-based approaches to osteoporosis.

  7. Greater association of peak neuromuscular performance with cortical bone geometry, bone mass and bone strength than bone density: A study in 417 older women.

    Science.gov (United States)

    Belavý, Daniel L; Armbrecht, Gabriele; Blenk, Tilo; Bock, Oliver; Börst, Hendrikje; Kocakaya, Emine; Luhn, Franziska; Rantalainen, Timo; Rawer, Rainer; Tomasius, Frederike; Willnecker, Johannes; Felsenberg, Dieter

    2016-02-01

    We evaluated which aspects of neuromuscular performance are associated with bone mass, density, strength and geometry. 417 women aged 60-94years were examined. Countermovement jump, sit-to-stand test, grip strength, forearm and calf muscle cross-sectional area, areal bone mineral content and density (aBMC and aBMD) at the hip and lumbar spine via dual X-ray absorptiometry, and measures of volumetric vBMC and vBMD, bone geometry and section modulus at 4% and 66% of radius length and 4%, 38% and 66% of tibia length via peripheral quantitative computed tomography were performed. The first principal component of the neuromuscular variables was calculated to generate a summary neuromuscular variable. Percentage of total variance in bone parameters explained by the neuromuscular parameters was calculated. Step-wise regression was also performed. At all pQCT bone sites (radius, ulna, tibia, fibula), a greater percentage of total variance in measures of bone mass, cortical geometry and/or bone strength was explained by peak neuromuscular performance than for vBMD. Sit-to-stand performance did not relate strongly to bone parameters. No obvious differential in the explanatory power of neuromuscular performance was seen for DXA aBMC versus aBMD. In step-wise regression, bone mass, cortical morphology, and/or strength remained significant in relation to the first principal component of the neuromuscular variables. In no case was vBMD positively related to neuromuscular performance in the final step-wise regression models. Peak neuromuscular performance has a stronger relationship with leg and forearm bone mass and cortical geometry as well as proximal forearm section modulus than with vBMD. Copyright © 2015 Elsevier Inc. All rights reserved.

  8. AICRG, Part II: Crestal bone loss associated with the Ankylos implant: loading to 36 months.

    Science.gov (United States)

    Chou, Cherng-Tzeh; Morris, Harold F; Ochi, Shigeru; Walker, Lori; DesRosiers, Deborah

    2004-01-01

    The Ankylos endosseous dental implant is a new implant design that will be available in the United States in early 2004. It features an internal tapered abutment connection, a smooth polished collar without threads at the coronal part of the implant body, and a roughened surface with variable threads on the body of the implant fixture. A precise, tapered, conical abutment connection eliminates the microgap often found in 2-stage implant systems. This microgap may allow the accumulation of food debris and bacteria, as well as micromovement between the parts during clinical function, both of which can lead to a localized inflammation and crestal bone loss. The purpose of this section of the study was to assess any crestal bone loss associated with this new implant. The clinical performance of this new implant design was studied under well-controlled clinical conditions. Over 1500 implants were placed and restored. The vertical crestal bone loss was measured "directly" between the time of implant placement and uncovering, using a periodontal probe. Serial dental radiographs were taken between loading, and the 12-, 24-, and 36-month follow-up visits to determine "indirect" crestal bone loss within a specific period. Bone loss varied among the participating centers from less than 0.5 mm to 2.0 mm. The largest amount of bone loss occurred between the time of placement and uncovering. Following loading, the mean bone loss for all implants for a period of 3 years was about 0.2 mm/y. The extent of the crestal bone loss after loading was minimal for patients regardless of age, gender, prosthetic applications, bone density, and remote or crestal incisions, as well as for smokers or nonsmokers. Bone loss per year is well within the guidelines of 0.2 mm/y proposed by others.

  9. Pregnancy, Breastfeeding, and Bone Health

    Science.gov (United States)

    ... go on to optimize their bone mass. Teen pregnancy and bone health. Teenage mothers may be at especially high risk for bone loss during pregnancy and for osteoporosis later in life. Unlike older ...

  10. Volleyball and Basketball Enhanced Bone Mass in Prepubescent Boys.

    Science.gov (United States)

    Zouch, Mohamed; Chaari, Hamada; Zribi, Anis; Bouajina, Elyès; Vico, Laurence; Alexandre, Christian; Zaouali, Monia; Ben Nasr, Hela; Masmoudi, Liwa; Tabka, Zouhair

    2016-01-01

    The aim of this study was to examine the effect of volleyball and basketball practice on bone acquisition and to determine which of these 2 high-impact sports is more osteogenic in prepubertal period. We investigated 170 boys (aged 10-12 yr, Tanner stage I): 50 volleyball players (VB), 50 basketball players (BB), and 70 controls. Bone mineral content (BMC, g) and bone area (BA, cm(2)) were measured by dual-energy X-ray absorptiometry at different sites. We found that, both VB and BB have a higher BMC at whole body and most weight-bearing and nonweight-bearing sites than controls, except the BMC in head which was lower in VB and BB than controls. Moreover, only VB exhibited greater BMC in right and left ultra-distal radius than controls. No significant differences were observed between the 3 groups in lumbar spine, femoral neck, and left third D radius BMC. Athletes also exhibited a higher BA in whole body, limbs, lumbar spine, and femoral region than controls. In addition, they have a similar BA in head and left third D radius with controls. The VB exhibited a greater BA in most radius region than controls and a greater femoral neck BA than BB. A significant positive correlation was reported between total lean mass and both BMC and BA in whole body, lumbar spine, total hip, and right whole radius among VB and BB. In summary, we suggest that volleyball and basketball have an osteogenic effect BMC and BA in loaded sites in prepubescent boys. The increased bone mass induced by both volleyball and basketball training in the stressed sites was associated to a decreased skull BMC. Moreover, volleyball practice produces a more sensitive mechanical stress in loaded bones than basketball. This effect seems translated by femoral neck expansion. Copyright © 2016 The International Society for Clinical Densitometry. Published by Elsevier Inc. All rights reserved.

  11. The decline in hip bone density after gastric bypass surgery is associated with extent of weight loss.

    Science.gov (United States)

    Fleischer, J; Stein, E M; Bessler, M; Della Badia, M; Restuccia, N; Olivero-Rivera, L; McMahon, D J; Silverberg, S J

    2008-10-01

    Bariatric surgery is common and may be associated with deleterious effects on the skeleton. Our objective was to assess bone metabolism and bone mineral density (BMD) after Roux-en-Y gastric bypass. We conducted a 1-yr prospective longitudinal study at a university hospital bariatric surgery practice and metabolic bone disease unit. Participants included 23 obese (mean body mass index 47 kg/m(2)) men and women, aged 20-64 yr. Serum PTH, 25-hydroxyvitamin D, osteocalcin, and urinary N-telopeptide, and BMD were assessed. Patients lost 45 +/- 2 kg 1 yr postoperatively (P rose (P hip (8.0%, P hip: r = 0.65, P = 0.02). Lumbar spine and distal radius sites did not change. After Roux-en-Y gastric bypass, there was evidence of calcium and vitamin D malabsorption. Bone turnover increased, and hip bone density rapidly declined. The decline in hip BMD was strongly associated with weight loss itself. Vigilance for nutritional deficiencies and bone loss in patients both before and after bariatric surgery is crucial.

  12. The effect of peri-implant bone exposure on soft tissue healing and bone loss in two adjacent implants

    Science.gov (United States)

    Shin, Seung-Yun; Kye, Seung-Boem; Hong, Jongrak; Paeng, Jun-Young

    2012-01-01

    Purpose The purpose of this study was to evaluate the soft tissue and bone change around two adjacent implants in one-stage implant surgery. Methods Eleven subjects (7 males, 4 females) who were needed placement of 2 adjacent implants in the molar area were included. The two implants were placed with the platform at the level of the alveolar crest. The interproximal bone between the 2 implants was not covered with gingiva. After surgery, an alginate impression was taken to record the gingival shape and radiographs were taken to evaluate implant placement. Using a master cast, the gingival height was measured at baseline, 4 weeks, and 12 weeks. In the radiograph, the alveolar bone level was measured at the mesial and distal side of both implants at baseline and 12 weeks. Results The exposed bone was covered with gingiva at both 4 and 12 weeks. Loss of alveolar bone around implants was found in all areas. The alveolar bone level in the exposed bone area did not differ from that in the non-exposed area. Conclusions This study showed that the alveolar bone level and gingival height around 2 adjacent implants in the exposed bone area did not differ from that in unexposed bone area. PMID:22413070

  13. Effect of hormone replacement therapy on the bone mass and urinary excretion of pyridinium cross-links.

    Science.gov (United States)

    Pardini, D P; Sabino, A T; Meneses, A M; Kasamatsu, T; Vieira, J G

    2000-01-06

    The menopause accelerates bone loss and is associated with an increased bone turnover. Bone formation may be evaluated by several biochemical markers. However, the establishment of an accurate marker for bone resorption has been more difficult to achieve. To study the effect of hormone replacement therapy (HRT) on bone mass and on the markers of bone resorption: urinary excretion of pyridinoline and deoxypyridinoline. Cohort correlational study. Academic referral center. 53 post-menopausal women, aged 48-58 years. Urinary pyr and d-pyr were measured in fasting urine samples by spectrofluorometry after high performance liquid chromatography and corrected for creatinine excretion measured before treatment and after 1, 2, 4 and 12 months. Bone mineral density (BMD) was measured by dual energy X-ray absorptiometry (DEXA) before treatment and after 12 months of HRT. The BMD after HRT was about 4.7% (P < 0.0004); 2% (P < 0.002); and 3% (P < 0. 01) higher than the basal values in lumbar spine, neck and trochanter respectively. There were no significant correlations between pyridinium cross-links and age, weight, menopause duration and BMD. The decrease in pyr and d-pyr was progressive after HRT, reaching 28.9% (P < 0.0002), and 42% (P < 0.0002) respectively after 1 year. Urinary pyridinoline and deoxypyridinoline excretion decreases early in hormone replacement therapy, reflecting a decrease in the bone resorption rate, and no correlation was observed with the bone mass evaluated by densitometry.

  14. The Use of Structural Allograft in Primary and Revision Knee Arthroplasty with Bone Loss

    Directory of Open Access Journals (Sweden)

    Raul A. Kuchinad

    2011-01-01

    Full Text Available Bone loss around the knee in the setting of total knee arthroplasty remains a difficult and challenging problem for orthopaedic surgeons. There are a number of options for dealing with smaller and contained bone loss; however, massive segmental bone loss has fewer options. Small, contained defects can be treated with cement, morselized autograft/allograft or metal augments. Segmental bone loss cannot be dealt with through simple addition of cement, morselized autograft/allograft, or metal augments. For younger or higher demand patients, the use of allograft is a good option as it provides a durable construct with high rates of union while restoring bone stock for future revisions. Older patients, or those who are low demand, may be better candidates for a tumour prosthesis, which provides immediate ability to weight bear and mobilize.

  15. Bone loss at implants and teeth in the same inter-proximal unit: A radiographic study.

    Science.gov (United States)

    Cecchinato, Denis; Marino, Massimiliano; Toia, Marco; Cecchinato, Francesca; Lindhe, Jan

    2018-02-10

    This study was performed to determine whether the distance between an implant and a tooth present in an inter-proximal unit influenced the amount of marginal bone loss that occurred at the two facing (adjacent) surfaces. One hundred and eighty patients with a total of 278 inter-proximal units were included. Radiographs of implants that also included adjacent (facing) natural tooth/teeth were digitalized, and various linear measurements were performed using a software program. The marginal bone level and the bone level change that had occurred during a mean of 5.8 years were assessed as well as distance between the implant and the adjacent tooth/teeth. The mean amount of additional marginal bone loss that took place during the observation period was about 0.4 mm at both implants and adjacent tooth surfaces. The horizontal distance between an implant and the facing tooth did not influence the amount of marginal bone loss that had occurred. In most inter-proximal units, more advanced bone loss (>1 mm, >2 mm) had ensued either at the implant or at the facing tooth surface. Advanced additional bone loss occurred at both the implant and the tooth in only about 3% of the examined subjects. Bone loss at implants and teeth appears to be a site-specific phenomenon and not dependent on the inter-proximal distance. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  16. Risk factors of low peak bone mass in Indonesian women

    Directory of Open Access Journals (Sweden)

    Ray Sugianto

    2014-10-01

    Full Text Available Background: Osteoporosis occurred in 64% of Indonesian women aged 60-64 years. The risk of osteoporosis can be reduced by achieving optimal peak bone mass in ages 25-32 years. However, 33.4% women had low peak bone mass (LPBM. Objective: We aimed to develop a tool to identify women at risk of developing LPBM in order to ameliorate this situation. Some risk/protective factors were explored in a case-control study. Method: We recruited 25 cases, those with LPBM (T-score <1 according to peripheral bone densitometry and 25 controls from Cengkareng District, West Jakarta. They were assessed using questionnaires to explore their historical intake of calcium, tea/coffee, and weight-bearing activity. We also measured BMI and body composition. Parameters among case and control groups were analyzed using independent T-test or Mann-Whitney, and odds ratio in relation to peak bone mass was also computed. Results: Between cases and controls, there were no differences observed in BMI, body composition, weight-bearing activity, and historical tea/coffee consumption. Calcium intake from sources other than milk and its derivatives were also found not to differ. Historical calcium index (HCI, measuring weekly calcium intake since childhood, was found lower in cases (median=160 vs 965; p=0.001. HCI cut-off analysis found that the values of 300 and 1000 yielded good specificity (80% and sensitivity (92% for LPBM. OR analysis identified those with HCI <1000 (OR=0.61; 95% CI: 2.05−54.95 as at moderate risk of developing LPBM, and HCI ≤ 300 as at higher risk. Conclusion: We concluded that, as low HCI was the risk factor for developing LPBM, calculation of HCI should be done to earlier identify women at risk, thus prompting earlier nutrition and lifestyle intervention to prevent the occurrence of LPBM and future osteoporosis.

  17. Peak bone mass density among residents of Metro Manila

    International Nuclear Information System (INIS)

    Lim-Abrahan, Mary Anne V.; Gacutan-Liwag, Aretha Ann C.; Balderas, Jubilia Araceli J.; Guanzon, Ma. Vicenta Luz; Guzman, Angel de

    2002-01-01

    Study Objectives: To determine the peak bone mass density among residents of Metro Manila using dual energy X-ray absorptiometry and to correlate factors such as age, height, weight, body mass index, total caloric, protein and calcium intake to bone mass density. Design: Cross sectional study Setting: Philippine General Hospital and St Luke's Medical Center, tertiary government and private owned hospitals, respectively. Subjects: Two hundred twenty-eight 228) healthy randomly chosen subjects from amongst hospital companion, aged 15-52 years old, distributed at 25 subjects per group of five per sex. Methods: Bone mass density measurements were done on lumbar spine and femoral neck using dual energy x-ray absorptiometry (Lunar DPXL). Ten (10) cc of blood was extracted on one hundred fourteen (114) patients; 5 cc of which was used for biochemical studies while the rest of the sample was stored for fixture studies. One hundred fourteen (114) patients were then interviewed using the Filipino version of the WHO questionnaire for the Study of Osteoporosis, and their nutritional intake was assessed using a previous day food recall. Results: At present, there are a total of 228 patients recruited. The mean weight and height were 57-43±11.17 kg and 158.16±8.44 cm, respectively, and the mean BMI was 22.99±4.11. The mean daily calcium intake was 501.17±357.79 gms/day (n=64). The mean BMD at the L2-L4 spine for females was 1.14±0.15 gm/cm 2 and 1.12±0.21 gm/cm 2 for the males. The highest BMD was 1.23±0.20 gm/cm 2 in the 35-39 year old age group for the females and 1.26±0.31 gm/cm 2 in the 30-34 age group for the males. The mean femoral neck BMD was 0.91±0.12 gm/cm 2 for the females and 1.00±0.13 gm/cm 2 for the males. The highest femoral neck BMD was 0.931±0.12 gm/cm 2 in the 20-24 females and 1.03±0.18 gm/cm 2 in the 20-24 age group for the males. Calcium intake and weight was significantly correlated in the lumbar spine. Height and sex was correlated with both

  18. Severe Bone Loss induced by Orthodontic Elastic Separator: A Rare Case Report

    Directory of Open Access Journals (Sweden)

    A E Vishwanath

    2013-01-01

    Full Text Available A displaced orthodontic elastic separator was proposed as being the source of a gingival abscess that progressed to severe bone loss and exfoliation in a healthy adolescent patient with sound periodontal status prior to commencement of orthodontic treatment. After 1 year of undergoing orthodontic treatment, the patient presented with dull pain and mobility in the left upper permanent molar for which there was no apparent etiology. On clinical examination, the patient had gingival inflammation, associated with a deep pocket and severe mobility (grade III in relation to the same teeth. Radiographic examination of an orthopantomogram and intraoral periapical radiography (IOPAR revealed a chronic periodontal abscess with severe necrosis of the periodontal ligament and severe alveolar bone loss. A radiopaque mass on the distal surface below the cementoenamel junction (CEJ was also observed. The patient was referred to the department of periodontics for assessment and appropriate treatment. On curettage, it was found that there was orthodontic elastic separator which was displaced subgingivally.

  19. Programmed administration of parathyroid hormone increases bone formation and reduces bone loss in hindlimb-unloaded ovariectomized rats

    Science.gov (United States)

    Turner, R. T.; Evans, G. L.; Cavolina, J. M.; Halloran, B.; Morey-Holton, E.

    1998-01-01

    Gonadal insufficiency and reduced mechanical usage are two important risk factors for osteoporosis. The beneficial effects of PTH therapy to reverse the estrogen deficiency-induced bone loss in the laboratory rat are well known, but the influence of mechanical usage in this response has not been established. In this study, the effects of programed administration of PTH on cancellous bone volume and turnover at the proximal tibial metaphysis were determined in hindlimb-unloaded, ovariectomized (OVX), 3-month-old Sprague-Dawley rats. PTH was administered to weight-bearing and hindlimb-unloaded OVX rats with osmotic pumps programed to deliver 20 microg human PTH (approximately 80 microg/kg x day) during a daily 1-h infusion for 7 days. Compared with sham-operated rats, OVX increased longitudinal and radial bone growth, increased indexes of cancellous bone turnover, and resulted in net resorption of cancellous bone. Hindlimb unloading of OVX rats decreased longitudinal and radial bone growth, decreased osteoblast number, increased osteoclast number, and resulted in a further decrease in cancellous bone volume compared with those in weight-bearing OVX rats. Programed administration of PTH had no effect on either radial or longitudinal bone growth in weight-bearing and hindlimb-unloaded OVX rats. PTH treatment had dramatic effects on selected cancellous bone measurements; PTH maintained cancellous bone volume in OVX weight-bearing rats and greatly reduced cancellous bone loss in OVX hindlimb-unloaded rats. In the latter animals, PTH treatment prevented the hindlimb unloading-induced reduction in trabecular thickness, but the hormone was ineffective in preventing either the increase in osteoclast number or the loss of trabecular plates. Importantly, PTH treatment increased the retention of a baseline flurochrome label, osteoblast number, and bone formation in the proximal tibial metaphysis regardless of the level of mechanical usage. These findings demonstrate that

  20. CHIP regulates bone mass by targeting multiple TRAF family members in bone marrow stromal cells.

    Science.gov (United States)

    Wang, Tingyu; Li, Shan; Yi, Dan; Zhou, Guang-Qian; Chang, Zhijie; Ma, Peter X; Xiao, Guozhi; Chen, Di

    2018-01-01

    Carboxyl terminus of Hsp70-interacting protein (CHIP or STUB1) is an E3 ligase and regulates the stability of several proteins which are involved in different cellular functions. Our previous studies demonstrated that Chip deficient mice display bone loss phenotype due to increased osteoclast formation through enhancing TRAF6 activity in osteoclasts. In this study we provide novel evidence about the function of CHIP. We found that osteoblast differentiation and bone formation were also decreased in Chip KO mice. In bone marrow stromal (BMS) cells derived from Chip -/- mice, expression of a panel of osteoblast marker genes was significantly decreased. ALP activity and mineralized bone matrix formation were also reduced in Chip- deficient BMS cells. We also found that in addition to the regulation of TRAF6, CHIP also inhibits TNFα-induced NF-κB signaling through promoting TRAF2 and TRAF5 degradation. Specific deletion of Chip in BMS cells downregulated expression of osteoblast marker genes which could be reversed by the addition of NF-κB inhibitor. These results demonstrate that the osteopenic phenotype observed in Chip -/- mice was due to the combination of increased osteoclast formation and decreased osteoblast differentiation. Taken together, our findings indicate a significant role of CHIP in bone remodeling.

  1. Overexpression of Dentin matrix protein 1 in Nestin+cells causes bone loss in mouse long bone.

    Science.gov (United States)

    Pan, Min; Weng, Yuteng; Sun, Yao

    2017-08-19

    The well-known matrix protein Dentin matrix protein 1 (DMP1) is expressed by osteoblasts and osteocytes in bone, and it controls bone mineralization. Recently, it has been found that DMP1 is also expressed in other cell types, such as chondrocytes. Nestin + cells are one important type of progenitor cell in bone marrow and are associated with bone remodeling. In our preliminary experiment, DMP1 could also be detected in Nestin + cells in bone marrow. This study was designed to explore the effect on bone of DMP1 in Nestin + cells. A transgenic mouse model with DMP1 expression driven by the Nestin promoter was generated. In vivo and in vitro experiments revealed that overexpression of DMP1 in Nestin + cells could limit the proliferation and osteogenic differentiation of BMMSCs, subsequently leading to decreased bone mass. Lower expression of bone matrix protein and a lower bone deposition rate were also observed. Meanwhile, overexpression of DMP1 in Nestin + cells had no influence on osteoclast activity. These data indicate that DMP1 plays negative roles in differentiation of Nestin + cells and bone formation. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Constraining the Stellar Mass Function in the Galactic Center via Mass Loss from Stellar Collisions

    Directory of Open Access Journals (Sweden)

    Douglas Rubin

    2011-01-01

    Full Text Available The dense concentration of stars and high-velocity dispersions in the Galactic center imply that stellar collisions frequently occur. Stellar collisions could therefore result in significant mass loss rates. We calculate the amount of stellar mass lost due to indirect and direct stellar collisions and find its dependence on the present-day mass function of stars. We find that the total mass loss rate in the Galactic center due to stellar collisions is sensitive to the present-day mass function adopted. We use the observed diffuse X-ray luminosity in the Galactic center to preclude any present-day mass functions that result in mass loss rates >10-5M⨀yr−1 in the vicinity of ~1″. For present-day mass functions of the form, dN/dM∝M-α, we constrain the present-day mass function to have a minimum stellar mass ≲7M⨀ and a power-law slope ≳1.25. We also use this result to constrain the initial mass function in the Galactic center by considering different star formation scenarios.

  3. No important influence of limited steroid exposure on bone mass during the first year after renal transplantation: a prospective, randomized, multicenter study.

    NARCIS (Netherlands)

    Meulen, C.G. ter; Riemsdijk, I.C. van; Hene, R.J.; Christiaans, M.H.; Borm, G.F.; Corstens, F.H.M.; Gelder, T. van; Hilbrands, L.B.; Weimar, W.; Hoitsma, A.J.

    2004-01-01

    BACKGROUND: Steroid-related bone loss is a recognized complication after renal transplantation. In a prospective, randomized, multicenter study we compared the influence of a steroid-free immunosuppressive regimen with a regimen with limited steroid exposure on the changes in bone mass after renal

  4. Impact of obesity on bone mass throughout adult life: Influence of gender and severity of obesity.

    Science.gov (United States)

    Maïmoun, Laurent; Mura, Thibault; Leprieur, Elodie; Avignon, Antoine; Mariano-Goulart, Denis; Sultan, Ariane

    2016-09-01

    Obesity improves areal bone mineral density (aBMD). However, it is unknown whether gender, ageing or the severity of obesity could modulate this effect and whether different bone sites are similarly affected. The aim of this observational study was to model the aBMD variation in obese patients from peak bone period to old age according to gender, bone localisation and severity of obesity. Five hundred and four obese patients (363 women, 72%) with a mean BMI of 38.5 ± 6.0 kg/m2, aged from 18.1 to 81.9 years (mean age 49.6 ± 14.6 years) were recruited. The whole body (WB), hip, lumbar spine (L1–L4) and one-third radius aBMDs were determined using dual-energy x-ray absorptiometry (DXA). Z-scores were significantly increased, above the age- and gender-related mean, both for women and men at WB (respectively 0.79 SD and 0.32 SD), hip (1.09 SD and 1.06 SD), one-third radius (1.70 SD and 0.45 SD) and L1–L4 levels (0.86 SD for women only). The improvement of Z-scores was significantly more marked in women compared to men at all bone sites, hip excepted. Furthermore, differences compared with normal values were significantly accentuated by ageing, without noticeable gender effect. In women, regardless of BMI and bone site, Z-scores were higher than normal values, this difference being most marked at WB, L1–L4 and hip levels for obese patients with a BMI above 40 kg/m2. Lean mass, but not fat mass, was independently associated with aBMD in men and women. This study demonstrated for the first time that obesity induces an improvement of aBMD, which is modulated by bone site location, severity of obesity, age and gender. The accentuation of peak bone mass combined with a reduction of bone loss rate with ageing may explain why obese patients present a lower prevalence of osteoporosis.

  5. Male Astronauts Have Greater Bone Loss and Risk of Hip Fracture Following Long Duration Spaceflights than Females

    Science.gov (United States)

    Ellman, Rachel; Sibonga, Jean; Bouxsein, Mary

    2010-01-01

    This slide presentation reviews bone loss in males and compares it to female bone loss during long duration spaceflight. The study indicates that males suffer greater bone loss than females and have a greater risk of hip fracture. Two possible reason for the greater male bone loss are that the pre-menopausal females have the estrogen protection and the greater strength of men max out the exercise equipment that provide a limited resistance to 135 kg.

  6. Are levels of bone turnover related to lower bone mass of adolescents previously fed a macrobiotic diet?

    NARCIS (Netherlands)

    Parsons, T.J.; Dusseldorp, van M.; Seibel, M.J.; Staveren, van W.A.

    2001-01-01

    Dutch adolescents who consumed a macrobiotic (vegan-type) diet in early life, demonstrate a lower relative bone mass than their omnivorous counterparts. We investigated whether subjects from the macrobiotic group showed signs of catching up with controls in terms of relative bone mass, reflected by

  7. Exercise in youth: High bone mass, large bone size, and low fracture risk in old age.

    Science.gov (United States)

    Tveit, M; Rosengren, B E; Nilsson, J Å; Karlsson, M K

    2015-08-01

    Physical activity is favorable for peak bone mass but if the skeletal benefits remain and influence fracture risk in old age is debated. In a cross-sectional controlled mixed model design, we compared dual X-ray absorptiometry-derived bone mineral density (BMD) and bone size in 193 active and retired male elite soccer players and 280 controls, with duplicate measurements of the same individual done a mean 5 years apart. To evaluate lifetime fractures, we used a retrospective controlled study design in 397 retired male elite soccer players and 1368 controls. Differences in bone traits were evaluated by Student's t-test and fracture risk assessments by Poisson regression and Cox regression. More than 30 years after retirement from sports, the soccer players had a Z-score for total body BMD of 0.4 (0.1 to 0.6), leg BMD of 0.5 (0.2 to 0.8), and femoral neck area of 0.3 (0.0 to 0.5). The rate ratio for fracture after career end was 0.6 (0.4 to 0.9) and for any fragility fracture 0.4 (0.2 to 0.9). Exercise-associated bone trait benefits are found long term after retirement from sports together with a lower fracture risk. This indicates that physical activity in youth could reduce the burden of fragility fractures. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  8. Monoaxial distraction of ulna to second metacarpal followed by single bone forearm in massive post infective radial bone loss

    Directory of Open Access Journals (Sweden)

    Jitendra N Pal

    2012-01-01

    Full Text Available Introduction: Radial bone loss associated with gross manus valgus deformity can be managed by open reduction internal fixation using intervening strut bone graft, callus distraction using ring or monoaxial fixator, and achieving union by distraction histogenesis. These methods are particularly suitable when bone loss is small. Single or staged procedure is described for congenital as well as in acquired extensive bone loss of radius. Distraction through radial proximal to distal segments, to achieve reduction of distal radio-ulnar joint (DRUJ, is also described in acquired cases. In the present series, functional results of distraction through ulna to 2 nd metacarpal is studied alongwith, functional status of hand, stability of wrist, level of patient′s satisfaction are also studied. Materials and Methods: 7 unilateral cases of radial loss (M = 5, F = 2 affecting 4 right hands of mean age 17 years (range 9 to 24 years were included in this study. They were treated by distracting through ulna to 2 nd metacarpal to achieve DRUJ alignment in first stage. Subsequently ulna was osteotomised and translated to distal stump of radius. It was then fixed to the distal radial remnant in 30° pronation in dominant and 30° supination non dominant hands. Results: Union was achieved in all cases associated with beneficial cross union of distal ulna. Hand functions improved near to normal, with fully corrected stable wrist joint, hypertrophied ulna and without recurrence. All of them had practically complete loss of forearm rotations, however patients were fully satisfied. Conclusion: This method is particularly suitable when associated with 6 cm or more radial bone loss. But when loss is small, sacrifice of one bone may not be justifiable.

  9. Abaloparatide, a novel PTH receptor agonist, increased bone mass and strength in ovariectomized cynomolgus monkeys by increasing bone formation without increasing bone resorption.

    Science.gov (United States)

    Doyle, N; Varela, A; Haile, S; Guldberg, R; Kostenuik, P J; Ominsky, M S; Smith, S Y; Hattersley, G

    2018-03-01

    Abaloparatide, a novel PTH1 receptor agonist, increased bone formation in osteopenic ovariectomized cynomolgus monkeys while increasing cortical and trabecular bone mass. Abaloparatide increased bone strength and maintained or enhanced bone mass-strength relationships, indicating preserved or improved bone quality. Abaloparatide is a selective PTH1R activator that is approved for the treatment of postmenopausal osteoporosis. The effects of 16 months of abaloparatide administration on bone formation, resorption, density, and strength were assessed in adult ovariectomized (OVX) cynomolgus monkeys (cynos). Sixty-five 9-18-year-old female cynos underwent OVX surgery, and 15 similar cynos underwent sham surgery. After a 9-month period without treatments, OVX cynos were allocated to four groups that received 16 months of daily s.c. injections with either vehicle (n = 17) or abaloparatide (0.2, 1, or 5 μg/kg/day; n = 16/dose level), while Sham controls received s.c. vehicle (n = 15). Bone densitometry (DXA, pQCT, micro-CT), qualitative bone histology, serum calcium, bone turnover markers, bone histomorphometry, and bone strength were among the key measures assessed. At the end of the 9-month post-surgical bone depletion period, just prior to the treatment phase, the OVX groups exhibited increased bone turnover markers and decreased bone mass compared with sham controls. Abaloparatide administration to OVX cynos led to increased bone formation parameters, including serum P1NP and endocortical bone formation rate. Abaloparatide administration did not influence serum calcium levels, bone resorption markers, cortical porosity, or eroded surfaces. Abaloparatide increased bone mass at the whole body, lumbar spine, tibial diaphysis, femoral neck, and femoral trochanter. Abaloparatide administration was associated with greater lumbar vertebral strength, and had no adverse effects on bone mass-strength relationships for the vertebrae, femoral neck, femoral

  10. The bone mass (BM) and chronic cardiac decompensation (CCD) in an elderly population.

    Science.gov (United States)

    Santangelo, Antonino; Testaì, Manuela; Mamazza, Grazia; Zuccaro, Carmela; Albani, Salvatore; Pavano, Salvatore; Cappello, Antonella; Sambataro, Domenico; Atteritano, Marco; Maugeri, Domenico

    2011-01-01

    This study intended to evaluate the existing correlation between the cardiac compensation and the bone mass, investigating the bone mineral density (BMD) in a population suffering from CCD or chronic heart disease (CHD). We enrolled 171 patients, all over the age of 70, being in the functional N.Y.H.A. Class II (Population A: 85 patients) and in Class III (Population B: 86 patients). All patients underwent an analysis of their cardiac functions using a Doppler echo-cardiographic method measuring the ventricular ejection fraction (VEF), as well as the BMD by means of a computerized bone mineralometric DEXA method, performed in vertebral and femoral measurement sites. Both populations proved to be osteopenic, displaying reduced values of BMD. Higher bone mineral losses were measured in the patients who had more severe cardiac insufficiency. The present data revealed a significant reduction of BMD in the N.Y.H.A. Class III patients, in correlation with the VEF (p<0.001), both in the lumbar vertebral area (p<0.01) and even more in the femoral sites (p<0.001), where a direct correlation exists between BMD and the VEF. On the basis of these findings one can suggest that the actual VEF level has an influence on the bone turnover, reducing the mineral content through various mechanisms of action. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  11. Polymorphisms of muscle genes are associated with bone mass and incident osteoporotic fractures in Caucasians

    DEFF Research Database (Denmark)

    Harsløf, Torben; Nielsen, Morten Frost Munk; Nielsen, T L

    2013-01-01

    .02 (95 % CI 1.20-3.41, p = 0.01). The same allele was associated with increased bone loss (BMC) at the total hip of 4.1 versus 0.5 % in individuals either heterozygous or homozygous for the common allele (p = 0.006), a reduced 10-year growth in bone area at the total hip of 0.4 versus 2.2 and 2......The interaction between muscle and bone is complex. The aim of this study was to investigate if variations in the muscle genes myostatin (MSTN), its receptor (ACVR2B), myogenin (MYOG), and myoD1 (MYOD1) were associated with fracture risk, bone mineral density (BMD), bone mineral content (BMC......), and lean body mass. We analyzed two independent cohorts: the Danish Osteoporosis Prevention Study (DOPS), comprising 2,016 perimenopausal women treated with hormone therapy or not and followed for 10 years, and the Odense Androgen Study (OAS), a cross-sectional, population-based study on 783 men aged 20...

  12. Bone mineral content and bone mineral density in female swimmers during the time of peak bone mass attainment

    Directory of Open Access Journals (Sweden)

    B Długołęcka

    2011-03-01

    Full Text Available The aim of this study was to assess bone mineral content and bone mineral density in girls practising swimming in the period of peak bone mass attainment in comparison to girls at the same age who are not actively involved in sports. This study involved girls from sports school specialising in swimming (n=41 aged 11-15 years, practising swimming (non-weight bearing activities, and girls at the same age not actively involved in sports (n=45. The current condition of bones was assessed based on the method of densitometry DEXA (lumbar spine L2-L4. Data on sports careers, including the length of training and training load, and hormonal status were collected using a diagnostic survey with an especially developed questionnaire. The quantitative composition of diet was determined based on 3 individual interviews on dietary intake in the last 24 hours preceding the test. Analysis of the results showed that the average values of the measured bone parameters were not different between the groups. However, we observed a trend of higher values in the control group. In the assessment of diet, we observed in both groups a deficiency in average calcium intake. Based on the results it can be concluded that the tested female swimmers were not at increased risk of developing osteopenia, when compared to girls not actively involved in sports.

  13. Spontaneous recovery of bone mass after cure of endogenous hypercortisolism.

    Science.gov (United States)

    Randazzo, Maria Elena; Grossrubatscher, Erika; Dalino Ciaramella, Paolo; Vanzulli, Angelo; Loli, Paola

    2012-06-01

    Patients with Cushing's syndrome (CS) develop osteopenia-osteoporosis. The present study evaluates the recovery of bone mass within 2 years after remission of hypercortisolism and in long term follow up, an issue rarely addressed. Twenty patients (6M, 14F, 3 post-menopausal, 15-64 years old), 15 with Cushing's disease, 2 with ectopic ACTH syndrome, 3 with ACTH-independent CS were studied. BMD, T and Z scores at lumbar spine and proximal femur were assessed by dual-energy X-ray absorptiometry before and 7-33 months after treatment of hypercortisolism. Five patients were treated with bisphosphonates. Four patients had hypogonadism and 4 GH-deficiency. At baseline all patients showed osteopenia/osteoporosis and the spine appeared more damaged than the femur; femur BMD was positively related with body mass index (BMI). No correlations were observed between spine and femur bone parameters and duration of disease or severity of hypercortisolism. Bone parameters did not differ in patients with or without GH or other pituitary deficiencies. After cure of hypercortisolism a significant improvement in spine BMD, Z and T scores and in femur Z and T scores was observed with normalization in 3 patients; there was no significant difference in percent improvement between femur and spine. The increase in bone parameters at spine and femur was independent from values at baseline. The percent increase in spine T and Z scores was positively related with time elapsed since cure. Bisphosphonates did not influence the recovery of bone mineralization. In long term follow up, after a median period of 7 years a further improvement in bone density was observed in 100% of patients at spine and in 9/11 at femur, although 8/11 patients still had femoral and/or vertebral T score in the range of osteopenia/osteoporosis. Spontaneous improvement of osteoporosis after cure of hypercortisolism occurs both at spine and femur, is independent from basal conditions and not affected by bisphosphonates

  14. Calcium requirements of growing rats based on bone mass, structure, or biomechanical strength are similar

    Science.gov (United States)

    Although calcium (Ca) supplementation increases bone density, the increase is small and the impact on bone strength and fracture risk is uncertain. To investigate if bone mass, morphology, and biomechanical properties are affected by deficient to copious dietary Ca concentrations, the long bones (ti...

  15. Risk factors for bone loss with prostate cancer in Korean men not receiving androgen deprivation therapy

    Directory of Open Access Journals (Sweden)

    Sun-Ouck Kim

    2009-04-01

    Full Text Available PURPOSE: Preexisting bone loss in men with prostate cancer is an important issue due to the accelerated bone loss during androgen deprivation therapy (ADT. In addition, a high prostate-specific antigen (PSA level has been reported to be related to bone metabolism. This study assessed the factors associated with osteoporosis in Korean men with non-metastatic prostate cancer before undergoing ADT. MATERIAL AND METHODS: The study enrolled patients admitted for a prostate biopsy because of a high PSA or palpable nodule on a digital rectal examination. We divided the patients (n = 172 according to the results of the biopsy: group I, non-metastatic prostate cancer (n = 42 and group II, benign prostatic hypertrophy (BPH; n = 130. The lumbar bone mineral density (BMD was evaluated using quantitative computed tomography. The demographic, health status, lifestyle, body mass index (BMI, serum testosterone concentration, and disease variables in prostate cancer (Gleason score, clinical stage, and PSA were analyzed prospectively to determine their effect on the BMD. RESULTS: The estimated mean T-score was higher in group I than in group II (-1.96 ± 3.35 vs. -2.66 ± 3.20, but without statistic significance (p = 0.235. The significant factors correlated with BMD in group I were a high serum PSA (ß = -0.346, p = 0.010 and low BMI (ß = 0.345, p = 0.014 in the multiple linear regression model. Also old age (r = -0.481, p = 0.001, a high serum PSA (r = -0.571, p < 0.001, low BMI (r = 0.598, p < 0.001, and a high Gleason’s score (r = -0.319, p = 0.040 were the factors related to BMD in the correlation. The significant factors correlated with BMD in group II were old age (ß = -0.324, p = 0.001 and BMI (ß = 0.143, p = 0.014 in the multiple linear regression model. CONCLUSIONS: The risk factors for osteoporosis in men with prostate cancer include a low BMI, and elevated serum PSA. Monitoring BMD from the outset of ADT is a logical first step in the clinical

  16. Mass loss on Himalayan glacier endangers water resources

    Science.gov (United States)

    Kehrwald, Natalie M.; Thompson, Lonnie G.; Tandong, Yao; Mosley-Thompson, Ellen; Schotterer, Ulrich; Alfimov, Vasily; Beer, Jürg; Eikenberg, Jost; Davis, Mary E.

    2008-11-01

    Ice cores drilled from glaciers around the world generally contain horizons with elevated levels of beta radioactivity including 36Cl and 3H associated with atmospheric thermonuclear bomb testing in the 1950s and 1960s. Ice cores collected in 2006 from Naimona'nyi Glacier in the Himalaya (Tibet) lack these distinctive marker horizons suggesting no net accumulation of mass (ice) since at least 1950. Naimona'nyi is the highest glacier (6050 masl) documented to be losing mass annually suggesting the possibility of similar mass loss on other high-elevation glaciers in low and mid-latitudes under a warmer Earth scenario. If climatic conditions dominating the mass balance of Naimona'nyi extend to other glaciers in the region, the implications for water resources could be serious as these glaciers feed the headwaters of the Indus, Ganges, and Brahmaputra Rivers that sustain one of the world's most populous regions.

  17. Kefir improves bone mass and microarchitecture in an ovariectomized rat model of postmenopausal osteoporosis.

    Science.gov (United States)

    Chen, H-L; Tung, Y-T; Chuang, C-H; Tu, M-Y; Tsai, T-C; Chang, S-Y; Chen, C-M

    2015-02-01

    Kefir treatment in ovariectomized (OVX) rats could significantly decrease the levels of bone turnover markers and prevent OVX-induced bone loss, deterioration of trabecular microarchitecture, and biomechanical dysfunction that may be due to increase intracellular calcium uptake through the TRPV6 calcium channel. Osteoporosis is a disease characterized by low bone mass and structural deterioration of bone tissue, leading to an increased fracture risk. The incidence of osteoporosis increases with age and occurs most frequently in postmenopausal women due to estrogen deficiency, as the balance between bone resorption and bone formation shifts towards increased levels of bone resorption. Among various methods of prevention and treatment for osteoporosis, an increase in calcium intake is the most commonly recommended preventive measure. Kefir is a fermented milk product made with kefir grains that degrade milk proteins into various peptides with health-promoting effects, including immunomodulating-, antithrombotic-, antimicrobial-, and calcium-absorption-enhancing bioactivities. The aim of this study is to investigate the effect of kefir on osteoporosis prophylaxis in an ovariectomized rat model. A total of 56 16-week-old female Sprague-Dawley (SD) rats were divided into 7 experimental groups: sham (normal), OVX/Mock, OVX/1X kefir (164 mg/kg BW/day), OVX/2X kefir (328 mg/kg BW/day), OVX/4X kefir (656 mg/kg BW/day), OVX/ALN (2.5 mg/kg BW/day), and OVX/REBONE (800 mg/kg BW/day). After 12-week treatment with kefir, the bone physiology in the OVX rat model was investigated. Accordingly, the aim of this study was to investigate the possible transport mechanism involved in calcium absorption using the Caco-2 human cell line. A 12-week treatment with kefir on the OVX-induced osteoporosis model reduced the levels of C-terminal telopeptides of type I collagen (CTx), bone turnover markers, and trabecular separation (Tb. Sp.). Additionally, treatment with kefir increased

  18. Levels of serotonin, sclerostin, bone turnover markers as well as bone density and microarchitecture in patients with high bone mass phenotype due to a mutation in Lrp5

    DEFF Research Database (Denmark)

    Nielsen, Morten Frost; Andersen, Tom E.; Gossiel, F

    2011-01-01

    CONTEXT: Patients with an activation mutation of the Lrp5 gene exhibit high bone mass (HBM). Limited information is available regarding compartment specific changes in bone. The relationship between the phenotype and serum serotonin is not well documented. Objective: to evaluate bone, serotonin...

  19. Propranolol Attenuates Risperidone-Induced Trabecular Bone Loss in Female Mice.

    Science.gov (United States)

    Motyl, Katherine J; DeMambro, Victoria E; Barlow, Deborah; Olshan, David; Nagano, Kenichi; Baron, Roland; Rosen, Clifford J; Houseknecht, Karen L

    2015-07-01

    Atypical antipsychotic (AA) drugs cause significant metabolic side effects, and clinical data are emerging that demonstrate increased fracture risk and bone loss after treatment with the AA, risperidone (RIS). The pharmacology underlying the adverse effects on bone is unknown. However, RIS action in the central nervous system could be responsible because the sympathetic nervous system (SNS) is known to uncouple bone remodeling. RIS treatment in mice significantly lowered trabecular bone volume fraction (bone volume/total volume), owing to increased osteoclast-mediated erosion and reduced osteoblast-mediated bone formation. Daytime energy expenditure was also increased and was temporally associated with the plasma concentration of RIS. Even a single dose of RIS transiently elevated expression of brown adipose tissue markers of SNS activity and thermogenesis, Pgc1a and Ucp1. Rankl, an osteoclast recruitment factor regulated by the SNS, was also increased 1 hour after a single dose of RIS. Thus, we inferred that bone loss from RIS was regulated, at least in part, by the SNS. To test this, we administered RIS or vehicle to mice that were also receiving the nonselective β-blocker propranolol. Strikingly, RIS did not cause any changes in trabecular bone volume/total volume, erosion, or formation while propranolol was present. Furthermore, β2-adrenergic receptor null (Adrb2(-/-)) mice were also protected from RIS-induced bone loss. This is the first report to demonstrate SNS-mediated bone loss from any AA. Because AA medications are widely prescribed, especially to young adults, clinical studies are needed to assess whether β-blockers will prevent bone loss in this vulnerable population.

  20. The mammalian lectin galectin-8 induces RANKL expression, osteoclastogenesis, and bone mass reduction in mice

    OpenAIRE

    Vinik, Yaron; Shatz-Azoulay, Hadas; Vivanti, Alessia; Hever, Navit; Levy, Yifat; Karmona, Rotem; Brumfeld, Vlad; Baraghithy, Saja; Attar-Lamdar, Malka; Boura-Halfon, Sigalit; Bab, Itai; Zick, Yehiel

    2015-01-01

    eLife digest The forces applied to the body during daily activities cause bones to be constantly remodeled, which is essential for keeping them healthy. In most adult organisms, new bone is created at the same rate at which old bone is destroyed. This means that overall bone mass remains the same. But, in diseases such as osteoporosis or bone cancer, bone is destroyed more rapidly than at which new bone is made. This leads to brittle bones that are more likely to fracture. Understanding how t...

  1. Total glucosides of paeony prevents juxta-articular bone loss in experimental arthritis

    OpenAIRE

    Wei, Chen Chao; You, Fan Tian; Mei, Li Yu; Jian, Sun; Qiang, Chen Yong

    2013-01-01

    Background Total glucosides of paeony (TGP) is a biologically active compound extracted from Paeony root. TGP has been used in rheumatoid arthritis therapy for many years. However, the mechanism by which TGP prevents bone loss has been less explored. Methods TGP was orally administered for 3?months to New Zealand rabbits with antigen-induced arthritis (AIA). Digital x-ray knee images and bone mineral density (BMD) measurements of the subchondral knee bone were performed before sacrifice. Chon...

  2. Buccal bone loss after immediate implantation can be reduced by the flapless approach

    Directory of Open Access Journals (Sweden)

    ARTHUR BELÉM NOVAES JR

    2011-10-01

    Full Text Available Aim: The aim of this study was to evaluate the buccal bone remodeling after immediate implantation with flap or flapless approach. Material and Methods: The mandibular bilateral premolars of 3 dogs were extracted and immediately three implants were placed in both hemi-arches of each dog. Randomly, one hemi-arch was treated with the flapless approach, while in the contra lateral hemi-arch tooth extractions and implant placement were done after mucoperiosteal flap elevation. Non-submerged healing of 12 weeks was provided for both groups. Histomorphometric analysis was done to compare buccal and lingual bone height loss, bone density and bone-to-implant contact in the groups. Fluorescence analysis was performed to investigate the dynamic of bone remodeling in the different groups. Results: There was a significant association between the surgical flap and the extent of bone resorption around immediate implants. The loss of buccal bone height was significantly lower in the flapless group when compared to the flap group (0.98 mm x 2.14 mm, respectively, p<0.05. The coronal and apical buccal bone densities of the flap group were significantly higher when compared to the lingual components, showing anatomical differences between the bone plates. Fluorescence analysis showed no major differences in bone healing between the flap and flapless groups, supporting that the higher loss of buccal bone height is linked to the anatomic characteristics of this plate and to the negative influence of the detachment of the periosteum in immediate implant therapy. Conclusion: The flapless approach for immediate post-extraction implants reduces the buccal bone height loss.

  3. Preventing and Treating Brittle Bones and Osteoporosis | NIH MedlinePlus the Magazine

    Science.gov (United States)

    ... Javascript on. Feature: Osteoporosis Preventing and Treating Brittle Bones and Osteoporosis Past Issues / Winter 2011 Table of ... at high risk due to low bone mass. Bone and Bone Loss Bone is living, growing tissue. ...

  4. Immunization with FSHβ fusion protein antigen prevents bone loss in a rat ovariectomy-induced osteoporosis model.

    Science.gov (United States)

    Geng, Wenxin; Yan, Xingrong; Du, Huicong; Cui, Jihong; Li, Liwen; Chen, Fulin

    2013-05-03

    Osteoporosis, a metabolic bone disease, threatens postmenopausal women globally. Hormone replacement therapy (HTR), especially estrogen replacement therapy (ERT), is used widely in the clinic because it has been generally accepted that postmenopausal osteoporosis is caused by estrogen deficiency. However, hypogonadal α and β estrogen receptor null mice were only mildly osteopenic, and mice with either receptor deleted had normal bone mass, indicating that estrogen may not be the only mediator that induces osteoporosis. Recently, follicle-stimulating hormone (FSH), the serum concentration of which increases from the very beginning of menopause, has been found to play a key role in postmenopausal osteoporosis by promoting osteoclastogenesis. In this article, we confirmed that exogenous FSH can enhance osteoclast differentiation in vitro and that this effect can be neutralized by either an anti-FSH monoclonal antibody or anti-FSH polyclonal sera raised by immunizing animals with a recombinant GST-FSHβ fusion protein antigen. Moreover, immunizing ovariectomized rats with the GST-FSHβ antigen does significantly prevent trabecular bone loss and thereby enhance the bone strength, indicating that a FSH-based vaccine may be a promising therapeutic strategy to slow down bone loss in postmenopausal women. Copyright © 2013 Elsevier Inc. All rights reserved.

  5. The clinical and radiological assessment of periodontal bone loss treatment using Emdogain.

    Science.gov (United States)

    Tokajuk, G; Pawińska, M; Kedra, B A

    2006-01-01

    ADMISSION: Emdogain is the only one biomaterial using biomicra effect which is practiced in periodontal surgery. The purpose of the study was a clinical and radiological assessment of bone loss treatment using Emdogain. There were 19 persons examined (11 women and 8 men) which have bone loss treated. Initial and monitoring examination after 10 months embraced clinical parameters such as PPD, CAL and radiological--based on intraoral x-ray pictures. Emdogain treatment was made according to surgical procedures. The research has shown reduction of the depth of periodontal pockets average about 3.4 mm and attachment connective tissue growth about 2.2 mm. Bone loss filling was on 67.1% level. Bone loss filling and growth of connective tissue attachment are in our research lower than in most of the others publications. Our observation concerned 10 months period so we should expect better effects after longer time. MOTIONS: Emdogain is safe and effective regeneration material.

  6. Effect of dietary soy isoflavones on bone loss in ovariectomized rats ...

    African Journals Online (AJOL)

    Purpose: To determine the effect of dietary soy isoflavone supplementation on bone loss in ovariectomized (OVX) rats. Methods: Forty-eight rats were assigned randomly to groups of OVX rats receiving soy isoflavones (20, 30, or 40 mg/kg of body weight daily), untreated OVX rats, or untreated intact rats. After 8 weeks, bone ...

  7. Vitamin K’s role in age-related bone loss: A critical review

    Science.gov (United States)

    The protective role of vitamin K in age-related bone loss continues to be controversial. The results of observational analyses are inconsistent with respect to associations between vitamin K status and bone, which arguably may be related to the limitations of observational study designs and analyt...

  8. The Ovariectomized Rat as a Model for Studying Alveolar Bone Loss in Postmenopausal Women

    Directory of Open Access Journals (Sweden)

    Bryan D. Johnston

    2015-01-01

    Full Text Available In postmenopausal women, reduced bone mineral density at the hip and spine is associated with an increased risk of tooth loss, possibly due to a loss of alveolar bone. In turn, having fewer natural teeth may lead to compromised food choices resulting in a poor diet that can contribute to chronic disease risk. The tight link between alveolar bone preservation, tooth retention, better nutritional status, and reduced risk of developing a chronic disease begins with the mitigation of postmenopausal bone loss. The ovariectomized rat, a widely used preclinical model for studying postmenopausal bone loss that mimics deterioration of bone tissue in the hip and spine, can also be used to study mineral and structural changes in alveolar bone to develop drug and/or dietary strategies aimed at tooth retention. This review discusses key findings from studies investigating mandible health and alveolar bone in the ovariectomized rat model. Considerations to maximize the benefits of this model are also included. These include the measurement techniques used, the age at ovariectomy, the duration that a rat is studied after ovariectomy and habitual diet consumed.

  9. COMPARSION BETWEEN PANORAMIC PERIAPICAL AND VERTICAL BITEWING RADIOGRAPHY IN DIAGNOSIS OF PERIODONTAL BONE LOSS

    Directory of Open Access Journals (Sweden)

    M SHEIKHI

    2000-09-01

    Full Text Available Introduction. For diagnosis and treatment planing and detection the quality of remaining Alveolar bone the radiography is very useful so the type of radiography is very important. The purpose of this study is the comparison between panoramic, periapical (bisecting technique and vertical bitewing radiographs in diagnosis of periodontitis. Methods. Twelve patients (3 male and 9 female with a mean age of 35, with a moderate to advanced periodontitis were evaluated. At the time of periodontal surgery, in the posterior site of two jaws (in 6 and 7 teeth, the bone loss was measured from CEJ to the base of alveolar bone, and compared with the radiographic findings of proximal bone loss. Results. The average of distance between CEJ and alveolar bone in 48 surfaces were 4.27 in clinic, 4.80 in panoramic, 2.62 in periapical (bisecting technique, 2.98 in vertical bitewing and 4.05 in panoramic without magnification. Discussion. In this research we cancluded that both techniques (periapical and vertical bitewing are not accurate in detection of proximal bone loss and there was significant difference between quantity of proximal bone in clinical measurment than radiographic measurment and this study showed that the panoramic (specially panoramic without magnification is more careful than other radiographic techniques in detection of proximal bone loss.

  10. Immediate Initiation of Antiretroviral Therapy for HIV Infection Accelerates Bone Loss Relative to Deferring Therapy

    DEFF Research Database (Denmark)

    Hoy, Jennifer F; Grund, Birgit; Roediger, Mollie P

    2017-01-01

    Both HIV infection and antiretroviral therapy (ART) are associated with lower bone mineral density (BMD) and increased fracture risk. Because the relative contributions of ART and untreated HIV to BMD loss are unclear, it is important to quantify the effect of ART on bone. We compared the effect ...

  11. Antiepileptic drug-induced bone loss in young male patients who have seizures.

    Science.gov (United States)

    Andress, Dennis L; Ozuna, Judy; Tirschwell, David; Grande, Lucinda; Johnson, Meshell; Jacobson, Arnold F; Spain, William

    2002-05-01

    Long-term antiepileptic drug (AED) therapy is a known risk factor for bone loss and fractures. Vitamin D deficiency is frequently cited as a cause for bone loss in patients who have seizures. To determine whether men who have seizures, but who are otherwise healthy, suffer substantial bone loss in the hip while taking AEDs. We prospectively examined femoral neck bone mineral density (BMD) by dual-energy x-ray absorptiometry in 81 consecutive men, aged between 25 and 54 years old (mean age, 45 years), who were attending an outpatient seizure clinic. Low BMD values were analyzed for known risk factors for bone loss. Dual-energy x-ray absorptiometry scans were repeated in 54 patients, 12 to 29 months later (mean, 19 months), to assess the rate of change in BMD over time. Multivariate linear regression analysis revealed that age (P<.001) and time receiving AEDs (P<.003) were the 2 important risk factors associated with low femoral neck BMD. Neither vitamin D deficiency, hypogonadism, cigarette smoking, nor excess alcohol intake were associated with low BMD after correcting for age and time on AEDs. Longitudinal analysis of femoral neck BMD revealed that only those in the youngest age group (25-44 years) showed significant declines in femoral neck BMD (1.8% annualized loss; 95% confidence interval, -3.1 to -0.9; P<.003) while receiving AED therapy. There was no evidence that a specific type of AED was more causally related to bone loss in this group although most patients were taking phenytoin sodium or carbamazepine during the longitudinal assessment. Long-term AED therapy in young male patients who have seizures causes significant bone loss at the hip in the absence of vitamin D deficiency. Dual-energy x-ray absorptiometry scanning of the hip is useful in identifying patients who are particularly susceptible to rapid bone loss while taking AEDs.

  12. Self-reported tooth loss and bone mineral density in older men and women.

    Science.gov (United States)

    May, H; Reader, R; Murphy, S; Khaw, K T

    1995-05-01

    It has been reported that postmenopausal women with osteoporosis have a higher than expected number of dentures and fewer teeth than women without osteoporosis. The relationship between self-reported tooth loss and bone mineral density (BMD) at the hip and spine in 608 men and 874 women, aged 65-76 years, was examined in a cross-sectional study. BMD was measured using dual X-ray absorptiometry. Twenty-four per cent of men and 27% of women had no natural teeth. There was a consistent decrease in BMD with increasing numbers of teeth lost in men. This relationship was independent of age, body mass index and smoking habit (trochanter r = -0.14, p < 0.0005; Ward's triangle r = -0.1, p < 0.005; and lumbar spine r = -0.07, p < 0.05) with between 5% and 9% difference in mean BMD at various sites between men who had all their teeth and men who had no teeth. There was no significant association between self-reported tooth loss and BMD in women. Tooth loss is associated with lower BMD in men; this relationship is less consistent in women.

  13. High fluoride and low calcium levels in drinking water is associated with low bone mass, reduced bone quality and fragility fractures in sheep.

    Science.gov (United States)

    Simon, M J K; Beil, F T; Rüther, W; Busse, B; Koehne, T; Steiner, M; Pogoda, P; Ignatius, A; Amling, M; Oheim, R

    2014-07-01

    Chronic environmental fluoride exposure under calcium stress causes fragility fractures due to osteoporosis and bone quality deterioration, at least in sheep. Proof of skeletal fluorosis, presenting without increased bone density, calls for a review of fracture incidence in areas with fluoridated groundwater, including an analysis of patients with low bone mass. Understanding the skeletal effects of environmental fluoride exposure especially under calcium stress remains an unmet need of critical importance. Therefore, we studied the skeletal phenotype of sheep chronically exposed to highly fluoridated water in the Kalahari Desert, where livestock is known to present with fragility fractures. Dorper ewes from two flocks in Namibia were studied. Chemical analyses of water, blood and urine were executed for both cohorts. Skeletal phenotyping comprised micro-computer tomography (μCT), histological, histomorphometric, biomechanical, quantitative backscattered electron imaging (qBEI) and energy-dispersive X-ray (EDX) analysis. Analysis was performed in direct comparison with undecalcified human iliac crest bone biopsies of patients with fluoride-induced osteopathy. The fluoride content of water, blood and urine was significantly elevated in the Kalahari group compared to the control. Surprisingly, a significant decrease in both cortical and trabecular bones was found in sheep chronically exposed to fluoride. Furthermore, osteoid parameters and the degree and heterogeneity of mineralization were increased. The latter findings are reminiscent of those found in osteoporotic patients with treatment-induced fluorosis. Mechanical testing revealed a significant decrease in the bending strength, concurrent with the clinical observation of fragility fractures in sheep within an area of environmental fluoride exposure. Our data suggest that fluoride exposure with concomitant calcium deficit (i) may aggravate bone loss via reductions in mineralized trabecular and cortical bone

  14. A clinical study evaluating bone mineral mass in the radius during skeletal growth

    International Nuclear Information System (INIS)

    Hagino, Hiroshi

    1989-01-01

    Using 125-I single photon absorptiometry, bone mineral measurements were performed on 206 healthy Japanese children (2 to 19 years of age). Bone mineral content (BMC), bone width (BW) and BMC/BW values were determined for the radius at distal 1/6 site (metaphysis) and distal 1/3 site (diaphysis). BMC/BW values at both sites correlated well with body height and weight. Bone mass in the diaphysis (distal 1/3 site) increased linearly during the 2-19 years of skeletal growth, but bone mass in the metaphysis (1/6 site) increased steeply during the pubertal period. In children receiving glucocorticoid therapy, bone mass was reduced in proportion to the duration of drug administration. In children under anticonvulsant therapy, the yearly increse in bone mass was significantly low especially in those patients with poor physical activity levels. Bone mineral decrease in the radius occurred in the children with hypopituitalism, hypothyroidism (cretinism), hyperthyroidism and Turner's syndrome. (author)

  15. Pattern of alveolar bone loss and reliability of measurements with the radiographic technique

    Energy Technology Data Exchange (ETDEWEB)

    Rise, J.; Albandar, J.M.

    1988-01-01

    The purposes of this paper were to study the pattern of bone loss among different teeth at the individual level and to study the effect of using different aggregated units of analysis on measurement error. Bone loss was assessed in standardized periapical radiographs from 293 subjects (18-68 years), and the mean bone loss score for each tooth type was calculated. These were then correlated by means of factor analysis to study the bone loss pattern. Reliability (measurement error) was studied by the internal consistency and the test-retest methods. The pattern of bone loss showed a unidimensional pattern, indicating that any tooth will work equally well as a dependent variable for epidemiologic descriptive purposes. However, a more thorough analysis also showed a multidimensional pattern in terms of four dimensions, which correspond to four tooth groups: incisors, upper premolars, lower premolars and molars. The four dimensions accounted for 80% of the toal variance. The multidimensional pattern may be important for the modeling of bone loss; thus different models may explain the four dimension (indices) used as dependent variables. The reliability (internal consistency) of the four indices was satisfactory. By the test-retest method, reliability was higher when the more aggregated unit (the individual) was used.

  16. Pattern of alveolar bone loss and reliability of measurements with the radiographic technique

    International Nuclear Information System (INIS)

    Rise, J.; Albandar, J.M.

    1988-01-01

    The purposes of this paper were to study the pattern of bone loss among different teeth at the individual level and to study the effect of using different aggregated units of analysis on measurement error. Bone loss was assessed in standardized periapical radiographs from 293 subjects (18-68 years), and the mean bone loss score for each tooth type was calculated. These were then correlated by means of factor analysis to study the bone loss pattern. Reliability (measurement error) was studied by the internal consistency and the test-retest methods. The pattern of bone loss showed a unidimensional pattern, indicating that any tooth will work equally well as a dependent variable for epidemiologic descriptive purposes. However, a more thorough analysis also showed a multidimensional pattern in terms of four dimensions, which correspond to four tooth groups: incisors, upper premolars, lower premolars and molars. The four dimensions accounted for 80% of the toal variance. The multidimensional pattern may be important for the modeling of bone loss; thus different models may explain the four dimension (indices) used as dependent variables. The reliability (internal consistency) of the four indices was satisfactory. By the test-retest method, reliability was higher when the more aggregated unit (the individual) was used

  17. Adipose-Derived Mesenchymal Stem Cells Prevent Systemic Bone Loss in Collagen-Induced Arthritis.

    Science.gov (United States)

    Garimella, Manasa G; Kour, Supinder; Piprode, Vikrant; Mittal, Monika; Kumar, Anil; Rani, Lekha; Pote, Satish T; Mishra, Gyan C; Chattopadhyay, Naibedya; Wani, Mohan R

    2015-12-01

    Rheumatoid arthritis (RA) is an autoimmune disease characterized by chronic inflammatory synovitis leading to joint destruction and systemic bone loss. The inflammation-induced bone loss is mediated by increased osteoclast formation and function. Current antirheumatic therapies primarily target suppression of inflammatory cascade with limited or no success in controlling progression of bone destruction. Mesenchymal stem cells (MSCs) by virtue of their tissue repair and immunomodulatory properties have shown promising results in various autoimmune and degenerative diseases. However, the role of MSCs in prevention of bone destruction in RA is not yet understood. In this study, we investigated the effect of adipose-derived MSCs (ASCs) on in vitro formation of bone-resorbing osteoclasts and pathological bone loss in the mouse collagen-induced arthritis (CIA) model of RA. We observed that ASCs significantly inhibited receptor activator of NF-κB ligand (RANKL)-induced osteoclastogenesis in both a contact-dependent and -independent manner. Additionally, ASCs inhibited RANKL-induced osteoclastogenesis in the presence of proinflammatory cytokines such as TNF-α, IL-17, and IL-1β. Furthermore, treatment with ASCs at the onset of CIA significantly reduced clinical symptoms and joint pathology. Interestingly, ASCs protected periarticular and systemic bone loss in CIA mice by maintaining trabecular bone structure. We further observed that treatment with ASCs reduced osteoclast precursors in bone marrow, resulting in decreased osteoclastogenesis. Moreover, ASCs suppressed autoimmune T cell responses and increased the percentages of peripheral regulatory T and B cells. Thus, we provide strong evidence that ASCs ameliorate inflammation-induced systemic bone loss in CIA mice by reducing osteoclast precursors and promoting immune tolerance. Copyright © 2015 by The American Association of Immunologists, Inc.

  18. Mammary tumorigenesis causes bone loss and dietary selenium supplementation does not affect such bone loss in male MMTV-PyMT mice

    Science.gov (United States)

    Cancer progression is accompanied by wasting that eventually results in cachexia characterized by significant weight loss and multi-organ functional failures. Limited clinical trials indicate that bone is adversely affected by cancer-associated wasting. To determine the effects of breast cancer on...

  19. Peak bone mass density among residents of metro Manila: A preliminary report

    International Nuclear Information System (INIS)

    Lim-Abrahan, M.A.; Guanzon, L.V.; Guzman, A.M. de; Villaruel, C.M.; Santos, F.

    1998-01-01

    occurring between the ages 15-20 years old and incidentally in 2 subjects with ages between 40-44. There seems to be little bone loss among males beyond the age 35, unlike in the females. Conclusions: Bone mass density among a sample of Metro Manila residents was determined using DEXA and the measurements on the lumbar spine and femoral neck. These were age-matched and matched with that of young adult based on Caucasian norm provided by the Lunar Co. Peak bone mass density in the L 2 L 4 level among the females is reached between the ages 30-35 years old, after which there is progressive bone loss with values in the 45-50 years old approximating the values in the 15-19 years old age range. A similar pattern is seen in the measurements taken at the femoral neck. Among males, the peak BMD is reached during the 30-35 years old, but there seems to be no rapid decline or rapid bone loss occurring thereafter, unlike in the female subjects. (author)

  20. Bone loss in women with type 1 diabetes

    DEFF Research Database (Denmark)

    tanderup joergensen, maj-britt; christensen, jesper olund; Svendsen, Ole Lander

    2015-01-01

    Background: Although osteoporosis has been investigated and debated in the diabetic population over the past decades, very little is known about the spontaneous changes in bone mineral density (BMD) and biochemical markers of bone turnover in pre- and postmenopausal type 1 diabetic (T1DM) women...... postmenopausal) were reexamined in 1997. Method: BMD was measured at femoral neck (f.n.), spine (L2 - L4), total body and forearm with DXA or SXA in 53 T1DM women. 4 years later a re-scan was carried out on 35 T1DM. Results: In premenopausal subjects a yearly decrease less than 1% at f.n., spine, forearm...... over time. Aim: To measure spontaneous changes in BMD and biochemical markers of bone turnover in pre- and postmenopausal T1DM women. Subjects: 53 T1DM women (31 premenopausal and 22 postmenopausal) from the outpatient clinic were enrolled in the study in 1993 and 35 (22 premenopausal, 13...

  1. Bone loss in the lower leg during 35 days of bed rest is predominantly from the cortical compartment

    OpenAIRE

    Rittweger, Joern; Mekjavić, Igor B.; Eiken, Ola; Pišot, Rado; Biolo, Gianni; Cirillo, Massimo; De Santo, Natale Gaspare; Bilancio, Giancarlo; Šimunič, Boštjan; Narici, Marco

    2013-01-01

    Immobilization-induced bone loss is usually greater in the epiphyses than in the diaphyses. The larger fraction of trabecular bone in the epiphyses than in the diaphyses offers an intuitive explanation to account for this phenomenon. However, recent evidence contradicts this notion and suggests that immobilization-induced bone loss from the distal tibia epiphysis is mainly from the cortical compartment. The aim of this study was to establish whether this pattern of bone loss was a general rul...

  2. Low vitamin D status has an adverse influence on bone mass, bone turnover, and muscle strength in Chinese adolescent girls.

    Science.gov (United States)

    Foo, Leng Huat; Zhang, Qian; Zhu, Kun; Ma, Guansheng; Hu, Xiaoqi; Greenfield, Heather; Fraser, David R

    2009-05-01

    Our goal in this cross-sectional study was to investigate the influence of low-vitamin D status on bone mass, bone turnover, and muscle strength in 301 healthy Chinese adolescent girls. Blood plasma 25-hydroxyvitamin D [25(OH)D] was measured by RIA and plasma and urine biomarkers of bone turnover were measured. Bone mineral content (BMC) and density and bone area for the whole body and the distal and proximal forearm were measured by dual energy X-ray absorptiometry. When vitamin D deficiency was defined as a serum 25(OH)D concentration of alkaline phosphatase in plasma and deoxypyridinoline:creatinine ratio in urine compared with those of the vitamin D-deficient girls. Adolescent girls with adequate vitamin D status had significantly higher bone mass and muscle strength compared with those with poor vitamin D status. This may be attributed in part to a lower rate of bone remodeling with adequate vitamin D status. These findings suggest that adequate vitamin D status during adolescence is important for optimizing bone mass, which may lead to higher peak bone mass at maturity. Poor vitamin D status also compromises forearm muscle strength.

  3. Immunization with FSHβ fusion protein antigen prevents bone loss in a rat ovariectomy-induced osteoporosis model

    Energy Technology Data Exchange (ETDEWEB)

    Geng, Wenxin; Yan, Xingrong; Du, Huicong; Cui, Jihong; Li, Liwen, E-mail: liven@nwu.edu.cn; Chen, Fulin, E-mail: chenfl@nwu.edu.cn

    2013-05-03

    Highlights: •A GST-FSH fusion protein was successfully expressed in E. coli. •Immunization with GST-FSH antigen can raise high-titer anti-FSH polyclonal sera. •Anti-FSH polyclonal sera can neutralize osteoclastogenic effect of FSH in vitro. •FSH immunization can prevent bone loss in a rat osteoporosis model. -- Abstract: Osteoporosis, a metabolic bone disease, threatens postmenopausal women globally. Hormone replacement therapy (HTR), especially estrogen replacement therapy (ERT), is used widely in the clinic because it has been generally accepted that postmenopausal osteoporosis is caused by estrogen deficiency. However, hypogonadal α and β estrogen receptor null mice were only mildly osteopenic, and mice with either receptor deleted had normal bone mass, indicating that estrogen may not be the only mediator that induces osteoporosis. Recently, follicle-stimulating hormone (FSH), the serum concentration of which increases from the very beginning of menopause, has been found to play a key role in postmenopausal osteoporosis by promoting osteoclastogenesis. In this article, we confirmed that exogenous FSH can enhance osteoclast differentiation in vitro and that this effect can be neutralized by either an anti-FSH monoclonal antibody or anti-FSH polyclonal sera raised by immunizing animals with a recombinant GST-FSHβ fusion protein antigen. Moreover, immunizing ovariectomized rats with the GST-FSHβ antigen does significantly prevent trabecular bone loss and thereby enhance the bone strength, indicating that a FSH-based vaccine may be a promising therapeutic strategy to slow down bone loss in postmenopausal women.

  4. Aging of marrow stromal (skeletal) stem cells and their contribution to age-related bone loss

    DEFF Research Database (Denmark)

    Bellantuono, Ilaria; Aldahmash, Abdullah; Kassem, Moustapha

    2009-01-01

    Marrow stromal cells (MSC) are thought to be stem cells with osteogenic potential and therefore responsible for the repair and maintenance of the skeleton. Age related bone loss is one of the most prevalent diseases in the elder population. It is controversial whether MSC undergo a process of aging...... in vivo, leading to decreased ability to form and maintain bone homeostasis with age. In this review we summarize evidence of MSC involvement in age related bone loss and suggest new emerging targets for intervention....

  5. Deriving the probabilities of water loss and ammonia loss for amino acids from tandem mass spectra.

    Science.gov (United States)

    Sun, Shiwei; Yu, Chungong; Qiao, Yantao; Lin, Yu; Dong, Gongjin; Liu, Changning; Zhang, Jingfen; Zhang, Zhuo; Cai, Jinjin; Zhang, Hong; Bu, Dongbo

    2008-01-01

    In protein identification through tandem mass spectrometry, it is critical to accurately predict the theoretical spectrum for a peptide sequence. The widely used prediction models, such as SEQUEST and MASCOT, ignore the intensity of the ions with important neutral losses, including water loss and ammonia loss. However, ignoring these neutral losses results in a significant deviation between the predicted theoretical spectrum and its experimental counterpart. Here, based on the "one peak, multiple explanations" observation, we proposed an expectation-maximization (EM) method to automatically learn the probabilities of water loss and ammonia loss for each amino acid. Then we employed these probabilities to design an improved statistical model for theoretical spectrum prediction. We implemented these methods and tested them on practical data. On a training set containing 1803 spectra, the experimental results show a good agreement with some known knowledge about neutral losses, such as the tendency of water loss from Asp, Glu, Ser, and Thr. Furthermore, on a testing set containing 941 spectra, the improved similarity between the experimental and predicted spectra demonstrates that this method can generate more reasonable predictions relative to the model that ignores neutral losses. As an application of the derived probabilities, we implemented a database searching method adopting the improved theoretical spectrum model with neutral loss ions estimated. Experimental results on Keller's data set demonstrate that this method can identify peptides more accurately than SEQUEST. In another application to validate SEQUEST's results, the reported peptide-spectrum pairs are reranked with respect to the similarity between experimental and predicted spectra. Experimental results on both LTQ and QSTAR data sets suggest that this reranking strategy can effectively distinguish the false negative predictions reported by SEQUEST.

  6. Automatic methods for alveolar bone loss degree measurement in periodontitis periapical radiographs.

    Science.gov (United States)

    Lin, P L; Huang, P Y; Huang, P W

    2017-09-01

    Periodontitis involves progressive loss of alveolar bone around the teeth. Hence, automatic alveolar bone loss measurement in periapical radiographs can assist dentists in diagnosing such disease. In this paper, we propose an automatic length-based alveolar bone loss measurement system with emphasis on a cementoenamel junction (CEJ) localization method: CEJ_LG. The bone loss measurement system first adopts the methods TSLS and ABLifBm, which we presented previously, to extract teeth contours and bone loss areas from periodontitis radiograph images. It then applies the proposed methods to locate the positions of CEJ, alveolar crest (ALC), and apex of tooth root (APEX), respectively. Finally the system computes the ratio of the distance between the positions of CEJ and ALC to the distance between the positions of CEJ and APEX as the degree of bone loss for that tooth. The method CEJ_LG first obtains the gradient of the tooth image then detects the border between the lower enamel and dentin (EDB) from the gradient image. Finally, the method identifies a point on the tooth contour that is horizontally closest to the EDB. Experimental results on 18 tooth images segmented from 12 periodontitis periapical radiographs, including 8 views of upper-jaw teeth and 10 views of lower-jaw teeth, show that 53% of the localized CEJs are within 3 pixels deviation (∼ 0.15 mm) from the positions marked by dentists and 90% have deviation less than 9 pixels (∼ 0.44 mm). For degree of alveolar bone loss, more than half of the measurements using our system have deviation less than 10% from the ground truth, and all measurements using our system are within 25% deviation from the ground truth. Our results suggest that the proposed automatic system can effectively estimate degree of horizontal alveolar bone loss in periodontitis radiograph images. We believe that our proposed system, if implemented in routine clinical practice, can serve as a valuable tool for early and accurate

  7. Evidence that increased calcium intake does not prevent early postmenopausal bone loss

    DEFF Research Database (Denmark)

    Hosking, D J; Ross, P D; Thompson, D E

    1998-01-01

    Calcium's ability to prevent bone loss in early postmenopausal women is controversial. We used data on 394 women from the placebo group of the Early Postmenopausal Interventional Cohort study, a clinical trial of alendronate, to investigate the relation of calcium intake to bone loss. Calcium...... intake was recorded, and bone mineral density (BMD) (in the lumbar spine, total body, forearm, and hip) and biochemical markers of bone turnover (serum total alkaline phosphatase, serum osteocalcin, and urinary N-telopeptide crosslink levels) were measured at baseline and annually thereafter. Women whose...... were not significantly associated with changes in BMD or bone turnover. Even women whose total calcium intake was >1333 mg/d (the highest tertile of total calcium intake) showed a decline in BMD of almost 2%, similar to declines in the lower two tertiles of total calcium intake (

  8. Spaceflight-induced Bone Loss: Is there a Risk for Accelerated Osteoporosis after Return?

    Science.gov (United States)

    Sibonga, Jean

    2008-01-01

    The evidence-to to-date suggests that the rapid rate of site-specific bone loss in space, due to the unbalanced stimulation of bone resorption, may predispose crew members to irreversible changes in bone structure and microarchitecture. No analyses conducted in the postflight period to assess microarchitectural changes. There is no complete analysis of skeletal recovery in the postflight period to evaluate the structural changes that accompany increases in DXA aBMD. Postflight analyses based upon QCT scans performed on limited crew members indicate reductions in hip bone strength and incomplete recovery at 1 year. No recovery of trabecular vBMD after 1 year return (HRP IWG). Time course of bone loss in space unknown.

  9. Trabecular bone loss after administration of the second-generation antipsychotic risperidone is independent of weight gain

    Science.gov (United States)

    Motyl, Katherine J.; Dick-de-Paula, Ingrid; Maloney, Ann E.; Lotinun, Sutada; Bornstein, Sheila; de Paula, Francisco J. A.; Baron, Roland; Houseknecht, Karen L.; Rosen, Clifford J.

    2011-01-01

    Second generation antipsychotics (SGAs) have been linked to metabolic and bone disorders in clinical studies, but the mechanisms of these side effects remain unclear. Additionally, no studies have examined whether SGAs cause bone loss in mice. Using in vivo and in vitro modeling we examined the effects of risperidone, the most commonly prescribed SGA, on bone in C57BL6/J (B6) mice. Mice were treated with risperidone orally by food supplementation at a dose of 1.25 mg/kg daily for 5 and 8 weeks, starting at 3.5 weeks of age. Risperidone reduced trabecular BV/TV, trabecular number and percent cortical area. Trabecular histomorphometry demonstrated increased resorption parameters, with no change in osteoblast number or function. Risperidone also altered adipose tissue distribution such that white adipose tissue mass was reduced and liver had significantly higher lipid infiltration. Next, in order to tightly control risperidone exposure, we administered risperidone by chronic subcutaneous infusion with osmotic minipumps (0.5 mg/kg daily for 4 weeks) in 7 week old female B6 mice. Similar trabecular and cortical bone differences were observed compared to the orally treated groups (reduced trabecular BV/TV, and connectivity density, and reduced percent cortical area) with no change in body mass, percent body fat, glucose tolerance or insulin sensitivity. Unlike in orally treated mice, risperidone infusion reduced bone formation parameters (serum P1NP, MAR and BFR/BV). Resorption parameters were elevated, but this increase did not reach statistical significance. To determine if risperidone could directly affect bone cells, primary bone marrow cells were cultured with osteoclast or osteoblast differentiation media. Risperidone was added to culture medium in clinically relevant doses of 0, 2.5 or 25 ng/ml. The number of osteoclasts was significantly increased by addition in vitro of risperidone while osteoblast differentiation was not altered. These studies indicate that

  10. Premature loss of bone remodeling compartment canopies is associated with deficient bone formation

    DEFF Research Database (Denmark)

    Jensen, Pia Rosgaard; Andersen, Thomas Levin; Søe, Kent

    2011-01-01

    A remarkable property of bone remodeling is that osteoblasts form bone matrix exactly where and when osteoclasts have removed it. The bone remodeling compartment (BRC) canopies that cover bone surfaces undergoing remodeling, were proposed to be critical players in this mechanism. Here, we provide...... support to this hypothesis by analyzing the changes in prevalence of BRC canopies during the progress of the remodeling cycle in a cohort of healthy individuals and in patients with endogenous Cushing's syndrome (CS), and by relating these changes in prevalence with the extent of bone forming surfaces....... Both cohorts showed almost 100% canopy coverage above resorbing osteoclasts, and only about 76% above bone forming surfaces. This indicates that BRC canopies are invariably associated with the early stage of the remodeling cycle, but may disappear later. Interestingly, in control and two thirds...

  11. Probiotic Lactobacillus rhamnosus GG prevents alveolar bone loss in a mouse model of experimental periodontitis.

    Science.gov (United States)

    Gatej, Simona M; Marino, Victor; Bright, Richard; Fitzsimmons, Tracy R; Gully, Neville; Zilm, Peter; Gibson, Rachel J; Edwards, Suzanne; Bartold, Peter M

    2018-02-01

    This study investigated the role of Lactobacillus rhamnosus GG (LGG) on bone loss and local and systemic inflammation in an in vivo mouse model of experimental periodontitis (PD). Experimental PD was induced in mice by oral inoculation with Porphyromonas gingivalis and Fusobacterium nucleatum over a period of 44 days. The probiotic LGG was administered via oral inoculation or oral gavage prior to, and during disease induction. The antimicrobial activity of LGG on the inoculum was also tested. Alveolar bone levels and gingival tissue changes were assessed using in vivo microcomputed tomography and histological analysis. Serum levels of mouse homologues for IL-8 were measured using multiplex assays. Pre-treatment with probiotics either via oral gavage or via oral inoculation significantly reduced bone loss (p Lactobacillus rhamnosus GG effectively suppresses bone loss in a mouse model of induced PD irrespective of the mode of administration. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  12. The effects of IL-6 and its receptors on bone loss in postmenopausal women

    International Nuclear Information System (INIS)

    Huang Xin; Yang Weiwen; Zhang Xueguang

    2001-01-01

    Objective: To investigate the effects of IL-6 and its receptors on bone loss in healthy women, and to assess the pathogenesis of the postmenopausal osteoporosis in women. Methods: One hundred and thirty one healthy women aged 31-72 including 64 sexual maturity women aged 31-52 were enrolled in four groups and 67 postmenopausal women, the years of menopause from 1 month to 23 years, were also enrolled in four groups. The bone mass of the lumbar-spine and femur were measured using dual-energy X-rays absorptiometry; the serum E 2 , FSH, BGP by radioimmunoassay (RIA); the serum IL-6, sIL-6R, sgp 130 by ELISA; the serum AKP, calcium, phosphate by auto-biochemistry instrument. Results: The BMD of lumbar-spine and right femur decreased following increase of age and the duration of menopause. Significant positive correlation was observed between BMD and E 2 . The serum IL-6, sIL-6R, sgp 130 level was low, and stable before menopause. The level of IL-6, sIL-6R, sgp 130 increased with variation of age and the duration of menopause. Significant negative correlation was observed between IL-6, sIL-6R, sgp 130 and E 2 , BMD. Serum AKP and BGP level was higher in postmenopausal women than that in sexual maturity women. The serum calcium level increased significantly soon after menopausal, then decreased to the normal level. The serum phosphate level had no difference in these groups. Conclusion: The main cause of postmenopausal osteoporosis is the unbalance of the bone formation and resorption

  13. Oral administration of 5-hydroxytryptophan aggravated periodontitis-induced alveolar bone loss in rats.

    Science.gov (United States)

    Li, Xianxian; Wu, Xiangnan; Ma, Yuanyuan; Hao, Zhichao; Chen, Shenyuan; Fu, Taozi; Chen, Helin; Wang, Hang

    2015-05-01

    5-Hydroxytryptophan (5-HTP) is the precursor of serotonin and 5-HTP has been widely used as a dietary supplement to raise serotonin level. Serotonin has recently been discovered to be a novel and important player in bone metabolism. As peripheral serotonin negatively regulates bone, the regular take of 5-HTP may affect the alveolar bone metabolism and therefore influence the alveolar bone loss induced by periodontitis. The aim of this study was to investigate the effect of 5-HTP on alveolar bone destruction in periodontitis. Male Sprague-Dawley rats were randomly divided into the following four groups: (1) the control group (without ligature); (2) the 5-HTP group (5-HTP at 25 mg/kg/day without ligature); (3) the L group (ligature+saline placebo); and (4) the L+5-HTP group (ligature+5-HTP at 25 mg/kg/day). Serum serotonin levels were determined by ELISA. The alveolar bones were evaluated with micro-computed tomography and histology. Tartrate-resistant acid phosphatase staining was used to assess osteoclastogenesis. The receptor activator of NF-kB ligand (RANKL) and osteoprotegerin (OPG) expression in the periodontium as well as the interleukin-6 positive osteocytes were analysed immunohistochemically. 5-HTP significantly increased serum serotonin levels. In rats with experimental periodontitis, 5-HTP increased alveolar bone resorption and worsened the micro-structural destruction of the alveolar bone. 5-HTP also stimulated osteoclastogenesis and increased RANKL/OPG ratio and the number of IL-6 positive osteocytes. However, 5-HTP treatment alone did not cause alveolar bone loss in healthy rats. The present study showed that 5-HTP aggravated alveolar bone loss, deteriorated alveolar bone micro-structure in the presence of periodontitis, which suggests 5-HTP administration may increase the severity of periodontitis. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Polar bears (Ursus maritimus), the most evolutionary advanced hibernators, avoid significant bone loss during hibernation.

    Science.gov (United States)

    Lennox, Alanda R; Goodship, Allen E

    2008-02-01

    Some hibernating animals are known to reduce muscle and bone loss associated with mechanical unloading during prolonged immobilisation,compared to humans. However, here we show that wild pregnant polar bears (Ursus maritimus) are the first known animals to avoid significant bone loss altogether, despite six months of continuous hibernation. Using serum biochemical markers of bone turnover, we showed that concentrations for bone resorption are not significantly increased as a consequence of hibernation in wild polar bears. This is in sharp contrast to previous studies on other hibernating species, where for example, black bears (Ursus americanus), show a 3-4 fold increase in serum bone resorption concentrations posthibernation,and must compensate for this loss through rapid bone recovery on remobilisation, to avoid the risk of fracture. In further contrast to black bears, serum concentrations of bone formation markers were highly significantly increased in pregnant female polar bears compared to non-pregnant,thus non-hibernating females both prior to and after hibernation. However, bone formation concentrations in new mothers were significantly reduced compared to pre-hibernation concentrations. The de-coupling of bone turnover in favour of bone formation prior to hibernation, suggests that wild polar bears may posses a unique physiological mechanism for building bone in protective preparation against expected osteopenia associated with disuse,starvation, and hormonal drives to mobilise calcium for reproduction, during hibernation. Understanding this physiological mechanism could have profound implications for a natural solution for the prevention of osteoporosis in animals subjected to captivity with inadequate space for exercise,humans subjected to prolonged bed rest while recovering from illness, or astronauts exposed to antigravity during spaceflight.© 2008 Elsevier Inc. All rights reserved.

  15. Contributions of lean mass and fat mass to bone mineral density: a study in postmenopausal women

    Directory of Open Access Journals (Sweden)

    Lai Thai Q

    2010-03-01

    Full Text Available Abstract Background The relative contribution of lean and fat to the determination of bone mineral density (BMD in postmenopausal women is a contentious issue. The present study was undertaken to test the hypothesis that lean mass is a better determinant of BMD than fat mass. Methods This cross-sectional study involved 210 postmenopausal women of Vietnamese background, aged between 50 and 85 years, who were randomly sampled from various districts in Ho Chi Minh City (Vietnam. Whole body scans, femoral neck, and lumbar spine BMD were measured by DXA (QDR 4500, Hologic Inc., Waltham, MA. Lean mass (LM and fat mass (FM were derived from the whole body scan. Furthermore, lean mass index (LMi and fat mass index (FMi were calculated as ratio of LM or FM to body height in metre squared (m2. Results In multiple linear regression analysis, both LM and FM were independent and significant predictors of BMD at the spine and femoral neck. Age, lean mass and fat mass collectively explained 33% variance of lumbar spine and 38% variance of femoral neck BMD. Replacing LM and FM by LMi and LMi did not alter the result. In both analyses, the influence of LM or LMi was greater than FM and FMi. Simulation analysis suggested that a study with 1000 individuals has a 78% chance of finding the significant effects of both LM and FM, and a 22% chance of finding LM alone significant, and zero chance of finding the effect of fat mass alone. Conclusions These data suggest that both lean mass and fat mass are important determinants of BMD. For a given body size -- measured either by lean mass or height --women with greater fat mass have greater BMD.

  16. Diabetes mellitus may increase bone loss after occlusal trauma and experimental periodontitis.

    Science.gov (United States)

    de Oliveira Diniz, Claudia K; Corrêa, Mônica G; Casati, Marcio Z; Nociti, Francisco H; Ruiz, Karina G; Bovi Ambrosano, Gláucia Maria; Sallum, Enilson A

    2012-10-01

    Diabetes mellitus (DM) involves metabolic changes that can negatively influence periodontal tissues, resulting in more prevalent and severe periodontitis and impaired bone formation. Occlusal trauma (OT) is an injury of the supportive periodontium that results in bone loss. It can be hypothesized that DM would increase bone loss after OT, mainly when associated with periodontitis. Thus, the aim of the present study is to evaluate the influence of DM on bone response in the furcation area of teeth subjected to OT in the presence, or absence, of experimental periodontitis (EP) in the rat model. Thirty-two male Wistar rats were assigned to four groups: 1) group 1 (G1): DM+OT+EP (n = 8); 2) group 2 (G2): DM+OT (n = 8); 3) group 3 (G3): OT+EP (n = 8); and 4) group 4 (G4): OT (n = 8). G1 and G2 received a single intraperitoneal injection of streptozotocin (STZ). After 10 days, G1 and G3 were subjected to EP by ligature placement. Fifteen days after the start of EP, OT was induced by the creation of a premature contact. The animals were euthanized 35 days after DM induction. DM enhanced bone loss in the presence of OT combined with EP, but did not increase bone loss in teeth subjected to OT alone. EP caused greater bone loss when associated with OT. Within the limits of this animal study, it can be concluded that DM enhances bone loss in the presence of occlusal trauma associated with EP.

  17. Bone Mass Density in Normal Iranian Population - Shariati Hospital (1996

    Directory of Open Access Journals (Sweden)

    M Pajoohi

    2002-09-01

    Full Text Available Introduction: The bone mass density (BMD may vary in different countries due to different genetic and environmental factors. This study was performed to determine the BMD of the normal population in Iran. Methods and Materials: Subjects were selected randomly from different works and social classes in Tehran (from the lowest to the highest. For each decade and sexes, 20 normal subjects were selected (140 men and 140 women. BMD was measured with a Hologic 1000 plus machine by dual energy x-ray absorptiometry (DEXA method for the lumber spine (L1, L2, L3, L4, L1-L4 and the femoral neck (neck, trochanter, intertrochanter, ward, total. Data were treated by polynomial approximation (3 rd degree. The obtained curves were compared with the standard Hologic curves for Caucasians. Results: In female the peak bone mass (PBM was 1.019 g/cm² for the lumbar spine and 0.832 for the femoral neck. In male the peak bone mass (PBM was 0.987 g/cm² for the lumbar spine and 0.907 for the femoral neck. The BMD of both lumbar spine and femoral neck were lower than the Hologic standards. For the lumbar spine the mean difference was 6.5 percent (2 to 21 percent, CI=1 for women and 13.8 percent (2 to 36 percent, CI=1.45 for men. In femoral neck the mean difference was 5.4 percent (2 to 16 percent, CI=0.96 for women and 4.6 percent (1 to 14 percent, CI=0.96 for men. Conclusion: The BMD of the lumbar spine and the femoral neck was lower in Iranian compared to the Hologic standards for Caucasians. This was seen in all age groups and in both sexes. It was less pronounced for the PBM in spine was lower in men than woman. The lower BMD of the spine in men was also seen in a cohort of patients with different diseases (inflammatory and non-inflammatory.

  18. Relationship between body mass, lean mass, fat mass, and limb bone cross-sectional geometry: Implications for estimating body mass and physique from the skeleton.

    Science.gov (United States)

    Pomeroy, Emma; Macintosh, Alison; Wells, Jonathan C K; Cole, Tim J; Stock, Jay T

    2018-01-18

    Estimating body mass from skeletal dimensions is widely practiced, but methods for estimating its components (lean and fat mass) are poorly developed. The ability to estimate these characteristics would offer new insights into the evolution of body composition and its variation relative to past and present health. This study investigates the potential of long bone cross-sectional properties as predictors of body, lean, and fat mass. Humerus, femur and tibia midshaft cross-sectional properties were measured by peripheral quantitative computed tomography in sample of young adult women (n = 105) characterized by a range of activity levels. Body composition was estimated from bioimpedance analysis. Lean mass correlated most strongly with both upper and lower limb bone properties (r values up to 0.74), while fat mass showed weak correlations (r ≤ 0.29). Estimation equations generated from tibial midshaft properties indicated that lean mass could be estimated relatively reliably, with some improvement using logged data and including bone length in the models (minimum standard error of estimate = 8.9%). Body mass prediction was less reliable and fat mass only poorly predicted (standard errors of estimate ≥11.9% and >33%, respectively). Lean mass can be predicted more reliably than body mass from limb bone cross-sectional properties. The results highlight the potential for studying evolutionary trends in lean mass from skeletal remains, and have implications for understanding the relationship between bone morphology and body mass or composition. © 2018 The Authors. American Journal of Physical Anthropology Published by Wiley Periodicals, Inc.

  19. Grizzly bears (Ursus arctos horribilis) and black bears (Ursus americanus) prevent trabecular bone loss during disuse (hibernation).

    Science.gov (United States)

    McGee-Lawrence, Meghan E; Wojda, Samantha J; Barlow, Lindsay N; Drummer, Thomas D; Castillo, Alesha B; Kennedy, Oran; Condon, Keith W; Auger, Janene; Black, Hal L; Nelson, O Lynne; Robbins, Charles T; Donahue, Seth W

    2009-12-01

    Disuse typically causes an imbalance in bone formation and bone resorption, leading to losses of cortical and trabecular bone. In contrast, bears maintain balanced intracortical remodeling and prevent cortical bone loss during disuse (hibernation). Trabecular bone, however, is more detrimentally affected than cortical bone in other animal models of disuse. Here we investigated the effects of hibernation on bone remodeling, architectural properties, and mineral density of grizzly bear (Ursus arctos horribilis) and black bear (Ursus americanus) trabecular bone in several skeletal locations. There were no differences in bone volume fraction or tissue mineral density between hibernating and active bears or between pre- and post-hibernation bears in the ilium, distal femur, or calcaneus. Though indices of cellular activity level (mineral apposition rate, osteoid thickness) decreased, trabecular bone resorption and formation indices remained balanced in hibernating grizzly bears. These data suggest that bears prevent bone loss during disuse by maintaining a balance between bone formation and bone resorption, which consequently preserves bone structure and strength. Further investigation of bone metabolism in hibernating bears may lead to the translation of mechanisms preventing disuse-induced bone loss in bears into novel treatments for osteoporosis.

  20. The Relation between Visceral and Subcutaneous Fat to Bone Mass among Egyptian Children and Adolescents

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    Sahar A. El-Masry

    2014-12-01

    CONCLUSIONS: Visceral and subcutaneous fat had significant positive association with bone mass in children; males and females respectively. On the contrary such association disappeared during adolescence.

  1. Germline deletion of AMP-activated protein kinase β subunits reduces bone mass without altering osteoclast differentiation or function

    Science.gov (United States)

    Quinn, Julian M. W.; Tam, Shanna; Sims, Natalie A.; Saleh, Hasnawati; McGregor, Narelle E.; Poulton, Ingrid J.; Scott, John W.; Gillespie, Matthew T.; Kemp, Bruce E.; van Denderen, B. J. W.

    2010-01-01

    Since AMP-activated protein kinase (AMPK) plays important roles in modulating metabolism in response to diet and exercise, both of which influence bone mass, we examined the influence of AMPK on bone mass in mice. AMPK is an αβγ heterotrimer where the β subunit anchors the α catalytic and γ regulatory subunits. Germline deletion of either AMPK β1 or β2 subunit isoforms resulted in reduced trabecular bone density and mass, but without effects on osteoclast (OC) or osteoblast (OB) numbers, as compared to wild-type littermate controls. We tested whether activating AMPK in vivo would enhance bone density but found AICA-riboside treatment caused a profound loss of trabecular bone volume (49.5%) and density and associated increased OC numbers. Consistent with this, AICA-riboside strongly stimulated OC differentiation in vitro, in an adenosine kinase-dependent manner. OCs and macrophages (unlike OBs) lacked AMPK β2 subunit expression, and when generated from AMPK β1−/− mice displayed no detectable AMPK activity. Nevertheless, AICA-riboside was equally effective at stimulating OC differentiation from wild-type or β1−/− progenitors, indicating that AMPK is not essential for OC differentiation or the stimulatory action of AICA-riboside. These results show that AMPK is required to maintain normal bone density, but not through bone cell differentiation, and does not mediate powerful osteolytic effects of AICA-riboside.—Quinn, J. M. W., Tam, S., Sims, N. A., Saleh, H., McGregor, N. E., Poulton, I. J., Scott, J. W., Gillespie, M. T., Kemp, B. E., van Denderen, B. J. W. Germline deletion of AMP-activated protein kinase β subunits reduces bone mass without altering osteoclast differentiation or function. PMID:19723702

  2. Hepatic Osteodystrophy: The Mechanism of Bone Loss in Hepatocellular Disease and the Effects of Pamidronate Treatment.

    Science.gov (United States)

    Spirlandeli, Adriano L; Dick-de-Paula, Ingrid; Zamarioli, Ariane; Jorgetti, Vanda; Ramalho, Leandra N Z; Nogueira-Barbosa, Marcello H; Volpon, Jose B; Jordão, Alceu A; Cunha, Fernando Q; Fukada, Sandra Y; de Paula, Francisco J A

    2017-04-01

    The present study was designed to evaluate the bone phenotypes and mechanisms involved in bone disorders associated with hepatic osteodystrophy. Hepatocellular disease was induced by carbon tetrachloride (CCl4). In addition, the effects of disodium pamidronate on bone tissue were evaluated. The study included 4 groups of 15 mice: a) C = mice subjected to vehicle injections; b) C+P = mice subjected to vehicle and pamidronate injections; c) CCl4+V = mice subjected to CCl4 and vehicle injections; and d) CCl4+P = mice subjected to CCl4 and pamidronate injections. CCl4 or vehicle was administered for 8 weeks, while pamidronate or vehicle was injected at the end of the fourth week. Bone histomorphometry and biomechanical analysis were performed in tibiae, while femora were used for micro-computed tomography and gene expression. CCl4 mice exhibited decreased bone volume/trabecular volume and trabecular numbers, as well as increased trabecular separation, as determined by bone histomorphometry and micro-computed tomography, but these changes were not detected in the group treated with pamidronate. CCl4 mice showed increased numbers of osteoclasts and resorption surface. High serum levels of receptor activator of nuclear factor-κB ligand and the increased expression of tartrate-resistant acid phosphatase in the bones of CCl4 mice supported the enhancement of bone resorption in these mice. Taken together, these results suggest that bone resorption is the main mechanism of bone loss in chronic hepatocellular disease in mice.

  3. Association Between Dietary Fiber Intake and Bone Loss in the Framingham Offspring Study.

    Science.gov (United States)

    Dai, Zhaoli; Zhang, Yuqing; Lu, Na; Felson, David T; Kiel, Douglas P; Sahni, Shivani

    2018-02-01

    Dietary fiber may increase calcium absorption, but its role in bone mineralization is unclear. Furthermore, the health effect of dietary fiber may be different between sexes. We examined the association between dietary fiber (total fiber and fiber from cereal, fruits, vegetables, nuts, and legumes) and bone loss at the femoral neck, trochanter, and lumbar spine (L 2 to L 4 ) in older men and women. In the Framingham Offspring Study, at baseline (1996-2001), diet was assessed using the Willett food-frequency questionnaire, and bone mineral density (BMD) was measured using dual-energy X-ray absorptiometry. Follow-up BMD was measured in 2001-2005 and 2005-2008 among 792 men (mean age 58.1 years; BMI 28.6 kg/m 2 ) and 1065 women (mean age 57.3 years; BMI 27.2 kg/m 2 ). We used sex-specific generalized estimating equations in multivariable regressions to estimate the difference (β) of annualized BMD change in percent (%ΔBMD) at each skeletal site per 5 g/d increase in dietary fiber. We further estimated the adjusted mean for bone loss (annualized %ΔBMD) among participants in each higher quartile (Q2, Q3, or Q4) compared with those in the lowest quartile (Q1) of fiber intake. Higher dietary total fiber (β = 0.06, p = 0.003) and fruit fiber (β = 0.10, p = 0.008) was protective against bone loss at the femoral neck in men but not in women. When examined in quartiles, men in Q2-Q4 of total fiber had significantly less bone loss at the femoral neck versus those in Q1 (all p fiber from vegetables appeared to be protective against spine bone loss in women but not men. There were no associations with cereal fiber or nut and legume fiber and bone loss in men or women. Our findings suggest that higher dietary fiber may modestly reduce bone loss in men at the hip. © 2017 American Society for Bone and Mineral Research. © 2017 American Society for Bone and Mineral Research.

  4. Systemic Administration of Allogeneic Mesenchymal Stem Cells Does Not Halt Osteoporotic Bone Loss in Ovariectomized Rats.

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    Shuo Huang

    Full Text Available Mesenchymal stem cells (MSCs have innate ability to self-renew and immunosuppressive functions, and differentiate into various cell types. They have become a promising cell source for treating many diseases, particular for bone regeneration. Osteoporosis is a common metabolic bone disorder with elevated systemic inflammation which in turn triggers enhanced bone loss. We hypothesize that systemic infusion of MSCs may suppress the elevated inflammation in the osteoporotic subjects and slow down bone loss. The current project was to address the following two questions: (1 Will a single dose systemic administration of allogenic MSCs have any effect on osteoporotic bone loss? (2 Will multiple administration of allogenic MSCs from single or multiple donors have similar effect on osteoporotic bone loss? 18 ovariectomized (OVX rats were assigned into 3 groups: the PBS control group, MSCs group 1 (receiving 2x106 GFP-MSCs at Day 10, 46, 91 from the same donor following OVX and MSCs group 2 (receiving 2x106 GFP-MSCs from three different donors at Day 10, 46, 91. Examinations included Micro-CT, serum analysis, mechanical testing, immunofluorescence staining and bone histomorphometry analysis. Results showed that BV/TV at Day 90, 135, BMD of TV and trabecular number at Day 135 in the PBS group were significantly higher than those in the MSCs group 2, whereas trabecular spacing at Day 90, 135 was significantly smaller than that in MSCs group 2. Mechanical testing data didn't show significant difference among the three groups. In addition, the ELISA assay showed that level of Rantes in serum in MSCs group 2 was significantly higher than that of the PBS group, whereas IL-6 and IL-10 were significantly lower than those of the PBS group. Bone histomorphometry analysis showed that Oc.S/BS and Oc.N/BS in the PBS group were significant lower than those in MSCs group 2; Ob.S/BS and Ob.N/BS did not show significant difference among the three groups. The current study

  5. Two Different Isomers of Vitamin E Prevent Bone Loss in Postmenopausal Osteoporosis Rat Model

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    Norliza Muhammad

    2012-01-01

    Full Text Available Postmenopausal osteoporotic bone loss occurs mainly due to cessation of ovarian function, a condition associated with increased free radicals. Vitamin E, a lipid-soluble vitamin, is a potent antioxidant which can scavenge free radicals in the body. In this study, we investigated the effects of alpha-tocopherol and pure tocotrienol on bone microarchitecture and cellular parameters in ovariectomized rats. Three-month-old female Wistar rats were randomly divided into ovariectomized control, sham-operated, and ovariectomized rats treated with either alpha-tocopherol or tocotrienol. Their femurs were taken at the end of the four-week study period for bone histomorphometric analysis. Ovariectomy causes bone loss in the control group as shown by reduction in both trabecular volume (BV/TV and trabecular number (Tb.N and an increase in trabecular separation (Tb.S. The increase in osteoclast surface (Oc.S and osteoblast surface (Ob.S in ovariectomy indicates an increase in bone turnover rate. Treatment with either alpha-tocopherol or tocotrienol prevents the reduction in BV/TV and Tb.N as well as the increase in Tb.S, while reducing the Oc.S and increasing the Ob.S. In conclusion, the two forms of vitamin E were able to prevent bone loss due to ovariectomy. Both tocotrienol and alpha-tocopherol exert similar effects in preserving bone microarchitecture in estrogen-deficient rat model.

  6. Role of glucocorticoid-induced leucine zipper (GILZ in inflammatory bone loss.

    Directory of Open Access Journals (Sweden)

    Nianlan Yang

    Full Text Available TNF-α plays a key role in the development of rheumatoid arthritis (RA and inflammatory bone loss. Unfortunately, treatment of RA with anti-inflammatory glucocorticoids (GCs also causes bone loss resulting in osteoporosis. Our previous studies showed that overexpression of glucocorticoid-induced leucine zipper (GILZ, a mediator of GC's anti-inflammatory effect, can enhance osteogenic differentiation in vitro and bone acquisition in vivo. To investigate whether GILZ could antagonize TNF-α-induced arthritic inflammation and protect bone in mice, we generated a TNF-α-GILZ double transgenic mouse line (TNF-GILZ Tg by crossbreeding a TNF-α Tg mouse, which ubiquitously expresses human TNF-α, with a GILZ Tg mouse, which expresses mouse GILZ under the control of a 3.6kb rat type I collagen promoter fragment. Results showed that overexpression of GILZ in bone marrow mesenchymal stem/progenitor cells protected mice from TNF-α-induced inflammatory bone loss and improved bone integrity (TNF-GILZ double Tg vs. TNF-αTg, n = 12-15. However, mesenchymal cell lineage restricted GILZ expression had limited effects on TNF-α-induced arthritic inflammation as indicated by clinical scores and serum levels of inflammatory cytokines and chemokines.

  7. Bone metabolism in patients with rheumatoid arthritis

    NARCIS (Netherlands)

    Bijlsma, J. W.

    1988-01-01

    Bone metabolism in patients with rheumatoid arthritis is reviewed. Two different entities are recognised: 1) a localised periarticular bone loss, due to inflammatory processes and 2) a generalised increased bone turnover, ultimately leading to a loss of axial bone mass. The mechanism of this loss of

  8. Local vibration enhanced the efficacy of passive exercise on mitigating bone loss in hindlimb unloading rats

    Science.gov (United States)

    Huang, Yunfei; Luan, Huiqin; Sun, Lianwen; Bi, Jingfang; Wang, Ying; Fan, Yubo

    2017-08-01

    Spaceflight induced bone loss is seriously affecting astronauts. Mechanical stimulation from exercise has been shown to restrain bone resorption as well as improve bone formation. Current exercise countermeasures in space cannot prevent it completely. Active exercise may convert to passive exercise in some ways because of the loss of gravity stimulus and inertia of exercise equipment. The aim of this study was to compare the efficacy of passive exercise or/and local vibration on counteracting the deterioration of the musculoskeletal system, including bone, muscle and tendons in tail-suspended rats. We hypothesized that local vibration could enhance the efficacy of passive exercise on countering bone loss. 40 Sprague Dawley rats were randomly distributed into five groups (n = 8, each): tail-suspension (TS), TS+35 Hz vibration (TSV), TS + passive exercise (TSP), TS + passive exercise coupled with 35 Hz vibration (TSPV) and control (CON). Passive exercise or/and local vibration was performed for 21 days. On day 0 and 21, bone mineral density (BMD) was observed by dual energy X-ray absorptiometry (DXA), and trabecular microstructure was evaluated by microcomputer tomography (μCT) analysis in vivo. Mechanical properties of tibia and tendon were determined by a mechanical testing system. Soleus and bone ash weight was tested by an electronic balance. Results showed that the passive exercise could not prevent the decrease of trabecular BMD, microstructure and bone ash weight induced by TS, whereas vibration and passive exercise coupled with local vibration (PV) could. Biomechanical properties of the tibia and tendon in TSPV group significantly increased compared with TS group. In summary, PV in this study was the best method in preventing weightlessness-induced bone loss. Consistent with our hypothesis, local vibration partly enhanced the effect of passive exercise. Furthermore, this study will be useful in improving countermeasure for astronauts, but also for the

  9. Androgen receptors and experimental bone loss - an in vivo and in vitro study.

    Science.gov (United States)

    Steffens, Joao Paulo; Coimbra, Leila Santana; Rossa, Carlos; Kantarci, Alpdogan; Van Dyke, Thomas E; Spolidorio, Luis Carlos

    2015-12-01

    Testosterone is a sex hormone that exhibits many functions beyond reproduction; one such function is the regulation of bone metabolism. The role played by androgen receptors during testosterone-mediated biological processes associated with bone metabolism is largely unknown. This study aims to use a periodontal disease model in vivo in order to assess the involvement of androgen receptors on microbial-induced inflammation and alveolar bone resorption in experimental bone loss. The impact of hormone deprivation was tested through both orchiectomy and chemical blockage of androgen receptor using flutamide (FLU). Additionally, the direct effect of exogenous testosterone, and the role of the androgen receptor, on osteoclastogenesis were investigated. Thirty male adult rats (n=10/group) were subjected to: 1-orchiectomy (OCX); 2-OCX sham surgery; or 3-OCX sham surgery plus FLU, four weeks before the induction of experimental bone loss. Ten OCX sham-operated rats were not subjected to experimental bone loss and served as healthy controls. The rats were euthanized two weeks later, so as to assess bone resorption and the production of inflammatory cytokines in the gingival tissue and serum. In order to study the in vitro impact of testosterone, osteoclasts were differentiated from RAW264.7 cells and testosterone was added at increasing concentrations. Both OCX and FLU increased bone resorption, but OCX alone was observed to increase osteoclast count. IL-1β production was increased only in the gingival tissue of OCX animals, whereas FLU-treated animals presented a decreased expression of IL-6. Testosterone reduced the osteoclast formation in a dose-dependent manner, and significantly impacted the production of TNF-α; FLU partially reversed these actions. When taken together, our results indicate that testosterone modulates experimental bone loss, and that this action is mediated, at least in part, via the androgen receptor. Copyright © 2015 Elsevier Inc. All rights

  10. Use of non-vascularized autologous fibula strut graft in the treatment of segmental bone loss.

    Science.gov (United States)

    Lawal, Y Z; Garba, E S; Ogirima, M O; Dahiru, I L; Maitama, M I; Abubakar, K; Ejagwulu, F S

    2011-01-01

    Fractures resulting in segmental bone loss challenge the orthopedic surgeon. Orthopedic surgeons in developed countries have the option of choosing vascularized bone transfers, bone transport, allogenic bone grafts, bone graft substitutes and several other means to treat such conditions. In developing countries where such facilities or expertise may not be readily available, the surgeon has to rely on other techniques of treatment. Non-vascularized fibula strut graft and cancellous bone grafting provides a reliable means of treating such conditions in developing countries. Over a period of six years all patients with segmental bone loss either from trauma or oncologic resection were included in the study. Data concerning the type of wound, size of gap and skin loss at tumor or fracture were obtained from clinical examination and radiographs. Ten patients satisfied the inclusion criteria for the study. The average length of the fibula strut is 7 cm, the longest being 15 cm and the shortest 3 cm long. The average defect length was 6.5 cm. Five patients had Gustillo III B open tibial fractures. One patient had recurrent giant cell tumor of the distal radius and another had a polyostotic bone cyst of the femur, which was later confirmed to be osteosarcoma. Another had non-union of distal tibial fracture with shortening. One other patient had gunshot injury to the femur and was initially managed by skeletal traction. The tenth patient had a comminuted femoral fracture. All trauma patients had measurement of missing segment, tissue envelope assessment, neurological examination, and debridement under general anesthesia with fracture stabilization with external fixators or casts. Graft incorporation was 80% in all treated patients. Autologous free, non-vascularized fibula and cancellous graft is a useful addition to the armamentarium of orthopedic surgeon in developing countries attempting to manage segmental bone loss, whether created by trauma or excision of tumors.

  11. Periprosthetic bone loss: diagnostic and therapeutic approaches [v2; ref status: indexed, http://f1000r.es/3pz

    Directory of Open Access Journals (Sweden)

    Loredana Cavalli

    2014-06-01

    Full Text Available Total joint replacement surgery is being performed on an increasingly large part of the population. Clinical longevity of implants depends on their osseointegration, which is influenced by the load, the characteristics of the implant and the bone-implant interface, as well as by the quality and quantity of the surrounding bone. Aseptic loosening due to periprosthetic osteolysis is the most frequent known cause of implant failure. Wear of prosthetic materials results in the formation of numerous particles of debris that cause a complex biological response. Dual-energy X-ray Absorptiometry (DXA is regarded as an accurate method to evaluate Bone Mineral Density (BMD around hip or knee prostheses. Further data may be provided by a new device, the Bone Microarchitecture Analysis (BMA, which combines bone microarchitecture quantification and ultra high resolution osteo-articular imaging. Pharmacological strategies have been developed to prevent bone mass loss and to extend implant survival. Numerous trials with bisphosphonates show a protective effect on periprosthetic bone mass, up to 72 months after arthroplasty. Strontium ranelate has been demonstrated to increase the osseointegration of titanium implants in treated animals with improvement of bone microarchitecture and bone biomaterial properties.

  12. Reverse total shoulder glenoid baseplate stability with superior glenoid bone loss.

    Science.gov (United States)

    Martin, Elise J; Duquin, Thomas R; Ehrensberger, Mark T

    2017-10-01

    Superior wear of the glenoid bone is common in patients with rotator cuff arthropathy. This can become a treatment challenge for patients who require shoulder arthroplasty. In reverse shoulder arthroplasty (RSA), glenoid bone loss may affect the stability of baseplate fixation. The primary purpose of this biomechanical laboratory study was to assess the initial fixation stability of RSA glenosphere baseplates in the presence of variable amounts of superior glenoid bone loss. High-density solid rigid polyurethane foam (30 pounds/cubic foot) was machined to model the glenoid with variable superior defects that provided different levels of support (100%, 90%, 75%, and 50%) for the glenosphere baseplate. The samples were cyclically loaded (0-750 N at 1 Hz for 5000 cycles) at a 60° glenohumeral angle. The micromotion and migration of the baseplate were calculated from displacement data captured during the loading tests with an array of 3 linear variable differential transformers mounted around the baseplate. Micromotion was significantly greater in samples with 50% defects compared with those with smaller defects. Migration was significantly greater after testing for all defect sizes. Initial fixation of RSA glenosphere baseplates was significantly reduced in models with 50% bone loss on the superior edge compared with models with less bone loss in this high-density bone foam model. Copyright © 2017 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

  13. Average annual crestal bone loss of ITI implants following the first year of loading

    Directory of Open Access Journals (Sweden)

    A Hosseinzadeh

    2006-07-01

    Full Text Available BACKGROUND: Long term success of dental implants directly depends on marginal bone resorption. The aim of this study was to determine the annual average bone loss on the mesial and distal aspects of implants following the first year of implantation. METHODS: This was a descriptive analytical study of patients treated with ITI (International Team of Implantology implants at the Dental School of Isfahan University of Medical Sciences from 1998-2002 (1377-81. A total of 15 patients with 41 implants were selected by convenience sampling method. The height of the alveolar bone was measured using panoramic radiography before and after loading with calipers to determine the average bone loss. Other information such as pocket depth, bleeding index, plaque index, gingival recession, was obtained by clinical examinations. The mean bone loss on the mesial & distal sides was analyzed by ANOVA at 0.05 level of significance. RESULTS: The average bone loss on the proximal sides of ITI implants obtained annually after the first year of loading was 0.084 ± 0.035 mm with slight difference on the mesial (0.092 ± 0.035 and distal (0.072 ± 0.033 sides. There was negligible difference between male and female patients. The average survival rate for thirty three months was 95.1%. CONCLUSION: The average bone loss on the mesial and distal sides of ITI implants compared with other studies was satisfactory. Survival and success rates were acceptable. KEYWORDS: Dental implants, bone resorption, survival rate, dental plaque index.

  14. Cognitive function in relation with bone mass and nutrition: cross-sectional association in postmenopausal women

    Directory of Open Access Journals (Sweden)

    Brownbill Rhonda A

    2004-05-01

    Full Text Available Abstract Background It has been suggested that bone loss and cognitive decline are co-occurring conditions, possibly due to their relationship with estrogen. Cognitive decline has been associated with various nutritional deficiencies as well. The purpose of this study was to determine if cognitive function is related to bone mineral density of various skeletal sites as well as to various dietary components. Methods Cross-sectional study with 97 healthy, Caucasian, postmenopausal women (59.4–85.0 years enrolled in a larger longitudinal study, investigating the effects of sodium on bone mass. The subjects were divided into two groups based on cognition scores. Group 1 represented lower and Group 2 higher scores on cognitive function. Bone mineral density from the whole body, lumbar spine, femur and forearm were measured with the Lunar DPX-MD instrument. Anthropometry was measured by standard methods. Cognition was assessed using the Mini Mental State Examination. Cumulative (over 2 years dietary intake from 3-day records was analyzed by Food Processor® (ESHA Research, Salem, OR and cumulative physical activity was assessed using Allied Dunbar National Fitness Survey for older adults. Results Subjects' cognition scores ranged from 22–30 (normal, 27–30, indicating all subjects had either mild or no cognitive impairment. Multiple Analysis of Covariance adjusted for age, height, weight, physical activity, alcohol, calcium, sodium and energy intake, showed a statistically significant association between cognition and bone mineral density of all measurable sites (η2 = 0.21, P 2 = 0.07, P = 0.050. Group 2 did have a significantly higher potassium intake (P = 0.023. In multiple regression, saturated fat had a significant negative relationship with cognitive function. Conclusions It appears mild degree of cognitive impairment may be a marker for lower bone mineral density as well as for a diet lower in carbohydrate and potassium intake, and higher

  15. Modeling of Blood Lead Levels in Astronauts Exposed to Lead from Microgravity-Accelerated Bone Loss

    Science.gov (United States)

    Garcia, H.; James, J.; Tsuji, J.

    2014-01-01

    Human exposure to lead has been associated with toxicity to multiple organ systems. Studies of various population groups with relatively low blood lead concentrations (bones, the adverse effects of lead correlate with the concentration of lead in the blood better than with that in the bones. NASA has found that prolonged exposure to microgravity during spaceflight results in a significant loss of bone minerals, the extent of which varies from individual to individual and from bone to bone, but generally averages about 0.5% per month. During such bone loss, lead that had been stored in bones would be released along with calcium. The effects on the concentration of lead in the blood (PbB) of various concentrations of lead in drinking water (PbW) and of lead released from bones due to accelerated osteoporosis in microgravity, as well as changes in exposure to environmental lead before, during, and after spaceflight were evaluated using a physiologically based pharmacokinetic (PBPK) model that incorporated exposure to environmental lead both on earth and in flight and included temporarily increased rates of osteoporosis during spaceflight.

  16. MicroRNA-29a mitigates glucocorticoid induction of bone loss and fatty marrow by rescuing Runx2 acetylation.

    Science.gov (United States)

    Ko, Jih-Yang; Chuang, Pei-Chin; Ke, Huei-Jin; Chen, Yu-Shan; Sun, Yi-Chih; Wang, Feng-Sheng

    2015-12-01

    Glucocorticoid treatment reportedly increases the morbidity of osteoporotic or osteonecrotic disorders. Exacerbated bone acquisition and escalated marrow adipogenesis are prominent pathological features of glucocorticoid-mediated skeletal disorders. MicroRNAs reportedly modulate tissue metabolism and remodeling. This study was undertaken to investigate the biological roles of microRNA-29a (miR-29a) in skeletal and fat metabolism in the pathogenesis of glucocorticoid-induced osteoporosis. Transgenic mice overexpressing miR-29a precursor or wild-type mice were given methylprednisolone. Bone mass, microarchitecture and histology were assessed by dual energy X-ray absorptiometry, μCT and histomorphometry. Differential gene expression and signaling components were delineated by quantitative RT-PCR and immunoblotting. Glucocorticoid treatment accelerated bone loss and marrow fat accumulation in association with decreased miR-29a expression. The miR-29a transgenic mice had high bone mineral density, trabecular microarchitecture and cortical thickness. miR-29a overexpression mitigated the glucocorticoid-induced impediment of bone mass, skeletal microstructure integrity and mineralization reaction and attenuated fatty marrow histopathology. Ex vivo, miR-29a increased osteogenic differentiation capacity and alleviated the glucocorticoid-induced promotion of adipocyte formation in primary bone-marrow mesenchymal progenitor cell cultures. Through inhibition of histone deacetylase 4 (HDAC4) expression, miR-29a restored acetylated Runx2 and β-catenin abundances and reduced RANKL, leptin and glucocorticoid receptor expression in glucocorticoid-mediated osteoporosis bone tissues. Taken together, glucocorticoid suppression of miR-29a signaling disturbed the balances between osteogenic and adipogenic activities, and thereby interrupted bone formation and skeletal homeostasis. miR-29a inhibition of HDAC4 stabilized the acetylation state of Runx2 and β-catenin that ameliorated the

  17. A Matrine Derivative M54 Suppresses Osteoclastogenesis and Prevents Ovariectomy-Induced Bone Loss by Targeting Ribosomal Protein S5.

    Science.gov (United States)

    Xin, Zhi; Jin, Cui; Chao, Liu; Zheng, Zhang; Liehu, Cao; Panpan, Pan; Weizong, Weng; Xiao, Zhai; Qingjie, Zhao; Honggang, Hu; Longjuan, Qin; Xiao, Chen; Jiacan, Su

    2018-01-01

    Post-menopausal osteoporosis (PMOP) is a metabolic bone disorder characterized by low bone mass and micro-architectural deterioration of bone tissue. The over-activated osteoclastogenesis, which plays an important role in osteoporosis, has become an important therapeutic target. M54 was a bioactive derivative of the Chinese traditional herb matrine. We found that M54 could suppress RANKL-induced osteoclastogenesis in bone marrow mononuclear cells and RAW264.7 cells through suppressing NF-κB, PI3K/AKT, and MAPKs pathways activity in vitro , and prevent ovariectomy-induced bone loss in vivo . Our previous study has proved that ribosomal protein S5 (RPS5) was a direct target of M19, based on which M54 was synthesized. Thus we deduced that M54 also targeted RPS5. During osteoclastogenesis, the RPS5 level in RAW264.7 cells was significantly down-regulated while M54 could maintain its level. After RPS5 was silenced, the inhibitory effects of M54 on osteoclastogenesis were partially compromised, indicating that M54 took effects through targeting RPS5. In summary, M54 was a potential clinical medicine for post-menopause osteoporosis treatment, and RPS5 is a possible key protein in PMOP.

  18. A Matrine Derivative M54 Suppresses Osteoclastogenesis and Prevents Ovariectomy-Induced Bone Loss by Targeting Ribosomal Protein S5

    Directory of Open Access Journals (Sweden)

    Zhi Xin

    2018-01-01

    Full Text Available Post-menopausal osteoporosis (PMOP is a metabolic bone disorder characterized by low bone mass and micro-architectural deterioration of bone tissue. The over-activated osteoclastogenesis, which plays an important role in osteoporosis, has become an important therapeutic target. M54 was a bioactive derivative of the Chinese traditional herb matrine. We found that M54 could suppress RANKL-induced osteoclastogenesis in bone marrow mononuclear cells and RAW264.7 cells through suppressing NF-κB, PI3K/AKT, and MAPKs pathways activity in vitro, and prevent ovariectomy-induced bone loss in vivo. Our previous study has proved that ribosomal protein S5 (RPS5 was a direct target of M19, based on which M54 was synthesized. Thus we deduced that M54 also targeted RPS5. During osteoclastogenesis, the RPS5 level in RAW264.7 cells was significantly down-regulated while M54 could maintain its level. After RPS5 was silenced, the inhibitory effects of M54 on osteoclastogenesis were partially compromised, indicating that M54 took effects through targeting RPS5. In summary, M54 was a potential clinical medicine for post-menopause osteoporosis treatment, and RPS5 is a possible key protein in PMOP.

  19. Running exercise alleviates trabecular bone loss and osteopenia in hemizygous β-globin knockout thalassemic mice.

    Science.gov (United States)

    Thongchote, Kanogwun; Svasti, Saovaros; Teerapornpuntakit, Jarinthorn; Krishnamra, Nateetip; Charoenphandhu, Narattaphol

    2014-06-15

    A marked decrease in β-globin production led to β-thalassemia, a hereditary anemic disease associated with bone marrow expansion, bone erosion, and osteoporosis. Herein, we aimed to investigate changes in bone mineral density (BMD) and trabecular microstructure in hemizygous β-globin knockout thalassemic (BKO) mice and to determine whether endurance running (60 min/day, 5 days/wk for 12 wk in running wheels) could effectively alleviate bone loss in BKO mice. Both male and female BKO mice (1-2 mo old) showed growth retardation as indicated by smaller body weight and femoral length than their wild-type littermates. A decrease in BMD was more severe in female than in male BKO mice. Bone histomorphometry revealed that BKO mice had decreases in trabecular bone volume, trabecular number, and trabecular thickness, presumably due to suppression of osteoblast-mediated bone formation and activation of osteoclast-mediated bone resorption, the latter of which was consistent with elevated serum levels of osteoclastogenic cytokines IL-1α and -1β. As determined by peripheral quantitative computed tomography, running increased cortical density and thickness in the femoral and tibial diaphyses of BKO mice compared with those of sedentary BKO mice. Several histomorphometric parameters suggested an enhancement of bone formation (e.g., increased mineral apposition rate) and suppression of bone resorption (e.g., decreased osteoclast surface), which led to increases in trabecular bone volume and trabecular thickness in running BKO mice. In conclusion, BKO mice exhibited pervasive osteopenia and impaired bone microstructure, whereas running exercise appeared to be an effective intervention in alleviating bone microstructural defect in β-thalassemia. Copyright © 2014 the American Physiological Society.

  20. Characterization of the bone matrix and its contribution to tooth loss in human cadaveric mandibles.

    Science.gov (United States)

    Matsuura, Takashi; Sasaki, Michiko; Katafuchi, Michitsuna; Tokutomi, Kentaro; Mizumachi, Emiri; Makino, Michiko; Naito, Toru; Sato, Hironobu

    2014-11-01

    It is uncertain as to what extent the major bone matrix constituents, mineral and collagen, show inter-individual variation and dependence on age and sex in jawbones. The purpose of this study was to clarify this uncertainty using cadaveric mandibles and investigate the association of bone matrix with the number of existing teeth. Cortical bone samples (1 × 1 cm) collected from the mental of 48 cadaveric mandibles (27 men and 21 women; age range = 56-93 years and 63-103 years, respectively) were used to quantify three bone matrix indices: mineral content, collagen content and extent of lysine hydroxylation of collagen. Associations with age and comparisons by sex were evaluated based on bone matrix indices and the numbers of existing teeth. The numbers of existing teeth were compared between the groups showing low and high bone matrix index values. A great amount of inter-individual variation was seen in all bone matrix indices. No bone matrix indices were associated with age, while the number of existing teeth was negatively associated with age. The bone matrix indices and number of existing teeth did not differ by sex. The number of existing teeth was nearly twice as high in the group showing high collagen content as in the low collagen group; however, an analysis of covariance showed a significant inter-group difference not from bone matrix indices, but rather from age. Interestingly, in comparison to femoral collagen, mandibular collagen showed lower lysine hydroxylation, which can represent an aspect of bone quality. Mandibular bone matrix shows great inter-individual variation and is independent of age and sex, but did not show as strong a relationship with tooth loss as age. Even so, mandibular collagen may represent a unique characteristic of bone matrix and deserves to be further investigated.

  1. Short-Term Hypoxia Accelerates Bone Loss in Ovariectomized Rats by Suppressing Osteoblastogenesis but Enhancing Osteoclastogenesis.

    Science.gov (United States)

    Wang, Guixin; Wang, Jia; Sun, Dawei; Xin, Jingyi; Wang, Liping; Huang, Dong; Wu, Weichi; Xian, Cory J

    2016-08-23

    BACKGROUND Although it has been reported that hypoxic exposure can attenuate hypertension, heart disease, diabetes, and some other diseases, effects of hypoxia on osteoporosis are still unknown. MATERIAL AND METHODS The current study investigated whether short-term hypoxic exposure (in comparison with normoxic conditions) affects bone metabolism in normal or ovariectomized (OVX) adult female rats in an vivo study. Micro-computed tomography bone volume/structural analyses, histological examination, and serum bone turnover biochemical assays were used. In addition, the expressions of some associated major regulatory molecules were measured in osteoblastic cultures. RESULTS While the 14-day hypoxic exposure did not change the bone-remodeling process in normal adult female rats, it decreased bone volume, osteoclast density, and serum bone formation marker (alkaline phosphatase) level, but increased osteoclast density and serum bone resorption marker (C-telopeptide of collagen) level in OVX rats. The bone marrow adipocyte number and serum fatty acid binding protein-4 level were increased in OVX-hypoxic rats compared with OVX-normoxic rats. Consistently, in human MG-63 osteoblastic cultures, the hypoxic condition suppressed protein expression of osteogenic transcriptional factors Runx2 and osterix, elevated protein expression of osteoclastogenic cytokine receptor activator of nuclear factor kappa-B ligand, but reduced that of osteoclastogenic inhibitor osteoprotegerin. CONCLUSIONS Our results suggest that, although no change occurred in the bone-remodeling process in normal adult female rats after hypoxic exposure, under the estrogen-deficient osteoporotic condition, the hypoxic condition can alter the bone microenvironment so that it may further impair osteoblastic differentiation and enhance osteoclastic formation, and thus reduce bone formation, enhance bone resorption, and accelerate bone loss.

  2. Effects of Gastric Bypass Surgery on Bone Mass and Microarchitecture Occur Early and Particularly Impact Postmenopausal Women.

    Science.gov (United States)

    Schafer, Anne L; Kazakia, Galateia J; Vittinghoff, Eric; Stewart, Lygia; Rogers, Stanley J; Kim, Tiffany Y; Carter, Jonathan T; Posselt, Andrew M; Pasco, Courtney; Shoback, Dolores M; Black, Dennis M

    2017-12-27

    Roux-en-Y gastric bypass (RYGB) surgery is a highly effective treatment for obesity but negatively affects the skeleton. Studies of skeletal effects have generally examined areal bone mineral density (BMD) by dual-energy X-ray absorptiometry (DXA), but DXA may be inaccurate in the setting of marked weight loss. Further, as a result of modestly sized samples of mostly premenopausal women and very few men, effects of RYGB by sex and menopausal status are unknown. We prospectively studied the effects of RYGB on skeletal health, including axial and appendicular volumetric BMD and appendicular bone microarchitecture and estimated strength. Obese adults (N = 48; 27 premenopausal and 11 postmenopausal women, 10 men) with mean ± SD body mass index (BMI) 44 ± 7 kg/m 2 were assessed before and 6 and 12 months after RYGB. Participants underwent spine and hip DXA, spine QCT, radius and tibia HR-pQCT, and laboratory evaluation. Mean 12-month weight loss was 37 kg (30% of preoperative weight). Overall median 12-month increase in serum collagen type I C-telopeptide (CTx) was 278% (p effects of RYGB on axial and appendicular bone mass and microarchitecture are detectable as early as 6 months postoperatively. Postmenopausal women are at highest risk for skeletal consequences and may warrant targeted screening or interventions. © 2017 American Society for Bone and Mineral Research. © 2017 American Society for Bone and Mineral Research.

  3. Pulsed electromagnetic fields (PEMF) attenuate changes in vertebral bone mass, architecture and strength in ovariectomized mice.

    Science.gov (United States)

    Lei, Tao; Liang, Zhuowen; Li, Feijiang; Tang, Chi; Xie, Kangning; Wang, Pan; Dong, Xu; Shan, Shuai; Jiang, Maogang; Xu, Qiaoling; Luo, Erping; Shen, Guanghao

    2018-03-01

    Pulsed electromagnetic fields (PEMF) has been investigated as a noninvasive alternative method to prevent bone loss for postmenopausal osteoporosis (OP), and the bone tissue involved in these studies are usually long bones such as femur and tibia in OP patients or rat models. However, few studies have investigated the effects of PEMF on the vertebral bone in mice with OP. This study aimed to investigate whether PEMF preserve lumbar vertebral bone mass, microarchitecture and strength in ovariectomized (OVX) mouse model of OP and its associated mechanisms. Thirty 3-month-old female BALB/c mice were randomly divided into three groups (n=10): sham-operated control (Sham), ovariectomy (OVX), and ovariectomy with PEMF treatment (OVX+PEMF). The OVX+PEMF group was exposed to 15Hz, 1.6 mT PEMF for 8h/day, 7days/week. After 8weeks, the mice were sacrificed. The OVX+PEMF group showed lower body weight gain of mice induced by estrogen deficiency compared with OVX group. Biochemical analysis of serum demonstrated that serum bone formation markers including bone specific alkaline phosphatase (BALP), serum osteocalcin (OCN), osteoprotegerin (OPG) and N-terminal propeptide of type I procollagen (P1NP) were markedly higher in OVX+PEMF group compared with OVX group. Besides, serum bone resorption markers including tartrate-resistant acid phosphatase 5b (TRAP-5b) and C-terminal crosslinked telopeptides of type I collagen (CTX-I) were markedly lower in OVX+PEMF group compared with OVX group. Biomechanical test observed that OVX+PEMF group showed higher compressive maximum load and stiffness of the lumbar vertebrae compared with OVX group. Micro-computed tomography (μCT) and histological analysis of lumbar vertebrae revealed that PEMF partially prevented OVX-induced decrease of trabecular bone mass and deterioration of trabecular bone microarchitecture in lumbar vertebrae. Real-time PCR showed that the canonical Wnt signaling pathway of the lumbar vertebrae, including Wnt3a, LRP5 and

  4. Marginal bone loss around tilted implants in comparison to straight implants: a meta-analysis.

    Science.gov (United States)

    Monje, Alberto; Chan, Hsun-Liang; Suarez, Fernando; Galindo-Moreno, Pablo; Wang, Hom-Lay

    2012-01-01

    The primary aim of this systematic review was to compare the amount of marginal bone loss around tilted and straight implants. As the secondary aim, the incidence of biomechanic complications was compared. An electronic literature search from five databases, for the years 2000 to 2011, and a hand search in implant-related journals were conducted. Clinical human studies in the English language that had reported marginal bone loss in tilted and straight implants at 12-months follow-up or longer were included. Mean marginal bone loss and the number of implants that were available for analysis were extracted from original articles for meta-analyses. Eight (six prospective and two retrospective) studies were included. One-year data were available in seven articles, which included 1,015 (451 tilted) implants. Three articles provided 3- to 5-year data from 302 (164 tilted) implants. No significant difference in weighted mean marginal bone loss was found between the tilted and straight implants in the short and medium terms. Three articles reported the incidence of biomechanic complications. There was not enough information to make a comparison. This meta-analysis failed to support the hypothesis that tilted implants that were splinted for the support of fixed prostheses had more marginal bone loss. Additionally, there was not enough evidence to claim a higher incidence of biomechanic complications in tilted implants. However, due to the nature of the study design of the included articles, caution should be exercised when interpreting the results of this review.

  5. The current state of bone loss research: data from spaceflight and microgravity simulators.

    Science.gov (United States)

    Nagaraja, Mamta Patel; Risin, Diana

    2013-05-01

    Bone loss is a well documented phenomenon occurring in humans both in short- and in long-term spaceflights. This phenomenon can be also reproduced on the ground in human and animals and also modeled in cell-based analogs. Since space flights are infrequent and expensive to study the biomedical effects of microgravity on the human body, much of the known pathology of bone loss comes from experimental studies. The most commonly used in vitro simulators of microgravity are clinostats while in vivo simulators include the bed rest studies in humans and hindlimb unloading experiments in animals. Despite the numerous reports that have documented bone loss in wide ranges in multiple crew members, the pathology remains a key concern and development of effective countermeasures is still a major task. Thus far, the offered modalities have not shown much success in preventing or alleviating bone loss in astronauts and cosmonauts. The objective of this review is to capture the most recent research on bone loss from spaceflights, bed rest and hindlimb unloading, and in vitro studies utilizing cellular models in clinostats. Additionally, this review offers projections on where the research has to focus to ensure the most rapid development of effective countermeasures. Copyright © 2012 Wiley Periodicals, Inc.

  6. Arthritis-induced alveolar bone loss is associated with changes in the composition of oral microbiota.

    Science.gov (United States)

    Corrêa, Jôice Dias; Saraiva, Adriana Machado; Queiroz-Junior, Celso Martins; Madeira, Mila Fernandes Moreira; Duarte, Poliana Mendes; Teixeira, Mauro Martins; Souza, Danielle Glória; da Silva, Tarcília Aparecida

    2016-06-01

    Rheumatoid arthritis (RA) and periodontitis (PD) are chronic inflammatory disorders that cause bone loss. PD tends to be more prevalent and severe in RA patients. Previous experimental studies demonstrated that RA triggers alveolar bone loss similarly to PD. The aim of this study was to investigate if arthritis-induced alveolar bone loss is associated with modification in the oral microbiota. Checkerboard DNA-DNA hybridization was employed to analyze forty oral bacterial species in 3 groups of C57BL/6 mice: control (n = 12; without any challenge); Y4 (n = 8; received oral inoculation of Aggregatibacter Actinomycetemcomitans strain FDC Y4) and AIA group (n = 12; chronic antigen-induced arthritis). The results showed that AIA and Y4 group exhibited similar patterns of bone loss. The AIA group exhibited higher counts of most bacterial species analyzed with predominance of Gram-negative species similarly to infection-induced PD. Prevotella nigrescens and Treponema denticola were detected only in the Y4 group whereas Campylobacter showae, Streptococcus mitis and Streptococcus oralis were only found in the AIA group. Counts of Parvimonas micra, Selenomonas Noxia and Veillonella parvula were greater in the AIA group whereas Actinomyces viscosus and Neisseira mucosa were in large proportion in Y4 group. In conclusion, AIA is associated with changes in the composition of the oral microbiota, which might account for the alveolar bone loss observed in AIA mice. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Radiation activated CHK1/MEPE pathway may contribute to microgravity-induced bone density loss

    Science.gov (United States)

    Zhang, Xiangming; Wang, Ping; Wang, Ya

    2015-11-01

    Bone density loss in astronauts on long-term space missions is a chief medical concern. Microgravity in space is the major cause of bone density loss (osteopenia), and it is believed that high linear energy transfer (LET) radiation in space exacerbates microgravity-induced bone density loss; however, the mechanism remains unclear. It is known that acidic serine- and aspartate-rich motif (ASARM) as a small peptide released by matrix extracellular phosphoglycoprotein (MEPE) promotes osteopenia. We previously discovered that MEPE interacted with checkpoint kinase 1 (CHK1) to protect CHK1 from ionizing radiation promoted degradation. In this study, we addressed whether the CHK1-MEPE pathway activated by radiation contributes to the effects of microgravity on bone density loss. We examined the CHK1, MEPE and secreted MEPE/ASARM levels in irradiated (1 Gy of X-ray) and rotated cultured human osteoblast cells. The results showed that radiation activated CHK1, decreased the levels of CHK1 and MEPE in human osteoblast cells and increased the release of MEPE/ASARM. These results suggest that the radiation-activated CHK1/MEPE pathway exacerbates the effects of microgravity on bone density loss, which may provide a novel targeting factor/pathway for a future countermeasure design that could contribute to reducing osteopenia in astronauts.

  8. The Effect of Calendula officinalis on Oxidative Stress and Bone Loss in Experimental Periodontitis

    Directory of Open Access Journals (Sweden)

    Mariana dos Reis Lima

    2017-06-01

    Full Text Available Periodontitis is associated with reduced antioxidant capacity and increased oxidative damage. Oxidative stress induces inflammation and bone loss contributing to the pathological progression of periodontal disease. Calendula officinalis (CLO has demonstrated anti-inflammatory and anti-oxidant activities. Therefore, the aim of this study was to evaluate the effect of CLO on oxidative stress and bone loss in rats subjected to experimental periodontitis (EP. For this, 72 male Wistar rats were divided into groups: Naïve, Saline (SAL and CLO. Rats received SAL or CLO (90 mg/kg 30 min before ligature and daily until the 11th day. Naïve group experienced no manipulation. After 11 days, the animals were euthanized and left maxillae collected for macroscopic analysis of alveolar bone loss (ABL. Periodontium was analyzed by macroscopy, scanning electron microscopy; confocal and light polarized microscopy. Immunohistochemical examination of DKK1, WNT 10b and β-catenin was performed. The gingival tissue was collected to reduced glutathione (GSH, superoxide dismutase (SOD, catalase (CAT and malondialdehyde (MDA analyses. The 11 days of ligature induced bone loss, breakdown of collagen fibers, increased the immunostaining DKK-1 while reduced WNT 10b and β-catenin expressions. Periodontitis reduced GSH, SOD, CAT and increase MDA. All findings were reversed by 90 mg/kg of CLO. In summary our findings demonstrated that CLO reduced oxidative stress and bone loss and preserved collagen fibers in rats with EP, with participation of WNT signaling pathway.

  9. The Effect of Calendula officinalis on Oxidative Stress and Bone Loss in Experimental Periodontitis

    Science.gov (United States)

    Lima, Mariana dos Reis; Lopes, Amanda P.; Martins, Conceição; Brito, Gerly A. C.; Carneiro, Virgínia C.; Goes, Paula

    2017-01-01

    Periodontitis is associated with reduced antioxidant capacity and increased oxidative damage. Oxidative stress induces inflammation and bone loss contributing to the pathological progression of periodontal disease. Calendula officinalis (CLO) has demonstrated anti-inflammatory and anti-oxidant activities. Therefore, the aim of this study was to evaluate the effect of CLO on oxidative stress and bone loss in rats subjected to experimental periodontitis (EP). For this, 72 male Wistar rats were divided into groups: Naïve, Saline (SAL) and CLO. Rats received SAL or CLO (90 mg/kg) 30 min before ligature and daily until the 11th day. Naïve group experienced no manipulation. After 11 days, the animals were euthanized and left maxillae collected for macroscopic analysis of alveolar bone loss (ABL). Periodontium was analyzed by macroscopy, scanning electron microscopy; confocal and light polarized microscopy. Immunohistochemical examination of DKK1, WNT 10b and β-catenin was performed. The gingival tissue was collected to reduced glutathione (GSH), superoxide dismutase (SOD), catalase (CAT) and malondialdehyde (MDA) analyses. The 11 days of ligature induced bone loss, breakdown of collagen fibers, increased the immunostaining DKK-1 while reduced WNT 10b and β-catenin expressions. Periodontitis reduced GSH, SOD, CAT and increase MDA. All findings were reversed by 90 mg/kg of CLO. In summary our findings demonstrated that CLO reduced oxidative stress and bone loss and preserved collagen fibers in rats with EP, with participation of WNT signaling pathway. PMID:28701962

  10. The Effect ofCalendula officinalison Oxidative Stress and Bone Loss in Experimental Periodontitis.

    Science.gov (United States)

    Lima, Mariana Dos Reis; Lopes, Amanda P; Martins, Conceição; Brito, Gerly A C; Carneiro, Virgínia C; Goes, Paula

    2017-01-01

    Periodontitis is associated with reduced antioxidant capacity and increased oxidative damage. Oxidative stress induces inflammation and bone loss contributing to the pathological progression of periodontal disease. Calendula officinalis (CLO) has demonstrated anti-inflammatory and anti-oxidant activities. Therefore, the aim of this study was to evaluate the effect of CLO on oxidative stress and bone loss in rats subjected to experimental periodontitis (EP). For this, 72 male Wistar rats were divided into groups: Naïve, Saline (SAL) and CLO. Rats received SAL or CLO (90 mg/kg) 30 min before ligature and daily until the 11th day. Naïve group experienced no manipulation. After 11 days, the animals were euthanized and left maxillae collected for macroscopic analysis of alveolar bone loss (ABL). Periodontium was analyzed by macroscopy, scanning electron microscopy; confocal and light polarized microscopy. Immunohistochemical examination of DKK1, WNT 10b and β-catenin was performed. The gingival tissue was collected to reduced glutathione (GSH), superoxide dismutase (SOD), catalase (CAT) and malondialdehyde (MDA) analyses. The 11 days of ligature induced bone loss, breakdown of collagen fibers, increased the immunostaining DKK-1 while reduced WNT 10b and β-catenin expressions. Periodontitis reduced GSH, SOD, CAT and increase MDA. All findings were reversed by 90 mg/kg of CLO. In summary our findings demonstrated that CLO reduced oxidative stress and bone loss and preserved collagen fibers in rats with EP, with participation of WNT signaling pathway.

  11. Recurrent anterior glenohumeral instability: the quantification of glenoid bone loss using magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Martins e Souza, Patricia [Fleury Medicina e Saude and Instituto Nacional de Traumatologia e Ortopedia, Rio de Janeiro, RJ (Brazil); Brandao, Bruno Lobo; Motta, Geraldo; Monteiro, Martim [Instituto Nacional de Traumatologia e Ortopedia, Rio de Janeiro, RJ (Brazil); Brown, Eduardo [Grupo Fleury Medicina Diagnostica, Rio de Janeiro, RJ (Brazil); Marchiori, Edson [Universidade Federal do Rio de Janeiro, Petropolis, RJ (Brazil)

    2014-08-15

    To investigate the accuracy of conventional magnetic resonance imaging (MRI) in determining the severity of glenoid bone loss in patients with anterior shoulder dislocation by comparing the results with arthroscopic measurements. Institutional review board approval and written consent from all patients were obtained. Thirty-six consecutive patients (29 men, seven women; mean age, 34.5 [range, 18-55] years) with recurrent anterior shoulder dislocation (≥3 dislocations; mean, 37.9; range, 3-200) and suspected glenoid bone loss underwent shoulder MRI before arthroscopy (mean interval, 28.5 [range, 9-73] days). Assessments of glenoid bone loss by MRI (using the best-fit circle area method) and arthroscopy were compared. Inter- and intrareader reproducibility of MRI-derived measurements was evaluated using arthroscopy as a comparative standard. Glenoid bone loss was evident on MRI and during arthroscopy in all patients. Inter- and intrareader correlations of MRI-derived measurements were excellent (intraclass correlation coefficient = 0.80-0.82; r = 0.81-0.86). The first and second observers' measurements showed strong (r = 0.76) and moderate (r = 0.69) interreader correlation, respectively, with arthroscopic measurements. Conventional MRI can be used to measure glenoid bone loss, particularly when employed by an experienced musculoskeletal radiologist. (orig.)

  12. Fusobacterium nucleatum and Tannerella forsythia Induce Synergistic Alveolar Bone Loss in a Mouse Periodontitis Model

    Science.gov (United States)

    Settem, Rajendra P.; El-Hassan, Ahmed Taher; Honma, Kiyonobu; Stafford, Graham P.

    2012-01-01

    Tannerella forsythia is strongly associated with chronic periodontitis, an inflammatory disease of the tooth-supporting tissues, leading to tooth loss. Fusobacterium nucleatum, an opportunistic pathogen, is thought to promote dental plaque formation by serving as a bridge bacterium between early- and late-colonizing species of the oral cavity. Previous studies have shown that F. nucleatum species synergize with T. forsythia during biofilm formation and pathogenesis. In the present study, we showed that coinfection of F. nucleatum and T. forsythia is more potent than infection with either species alone in inducing NF-κB activity and proinflammatory cytokine secretion in monocytic cells and primary murine macrophages. Moreover, in a murine model of periodontitis, mixed infection with the two species induces synergistic alveolar bone loss, characterized by bone loss which is greater than the additive alveolar bone losses induced by each species alone. Further, in comparison to the single-species infection, mixed infection caused significantly increased inflammatory cell infiltration in the gingivae and osteoclastic activity in the jaw bones. These data show that F. nucleatum subspecies and T. forsythia synergistically stimulate the host immune response and induce alveolar bone loss in a murine experimental periodontitis model. PMID:22547549

  13. Digital radiographic evaluation of alveolar bone loss, density and lamina dura integrity on post splinting mandibular anterior with chronic periodontitis

    Science.gov (United States)

    Rafini, F.; Priaminiarti, M.; Sukardi, I.; Lessang, R.

    2017-08-01

    The healing of periodontal splinting can be detected both with clinical and radiographic examination. In this study, the alveolar bone was evaluated by radiographic digital periapical analysis. Periodontal tooth splinting is periodontal support therapy used to prevent periodontal injury during repair and regeneration of periodontal therapy. Radiographic digital periapical analysis of alveolar bone in the mandibular anterior region with chronic periodontitis and 2/3 cervical bone loss after three months of periodontal splinting. Eighty four proximal site (43 mesial and 41 distal) from 16 patients with chronic periodontitis and treated with spinting were examined by taking periapical digital radiographic at day 1 and 91. The bone loss, bone density and utility of lamina dura were evaluated. The statistical analysis after three months evaluation using T-test for bone loss, Wilcoxon sign rank test for bone density and utility lamina dura showed no significantly differences (palveolar bone loss after three months splinting.

  14. Changes in Bone Turnover Markers and Bone Mass with Reducing Levels of Jumping Exercise Regimens in Female Rats

    OpenAIRE

    Ooi, Foong Kiew; Singh, Rabindarjeet; Singh, Harbindar Jeet

    2012-01-01

    Purpose To date, little is known about the effects of a reduced level of jumping exercise regimens on bone turnover markers and mass. This study investigates the effects of different jumping exercise regimens with varying exercise loads on serum bone turnover markers and bone mass in female rats. Methods A total of 144 female rats aged 12 weeks, were divided into 12 groups as follows: no exercise for 8 (8S) or 32 weeks (32S), or 8 weeks of standard training program (8STP) consisting of 200 ju...

  15. Propranolol, a β-adrenergic antagonist, attenuates the decrease in trabecular bone mass in high calorie diet fed growing mice.

    Science.gov (United States)

    Baek, Kyunghwa; Hwang, Hyo Rin; Park, Hyun-Jung; Kwon, Arang; Qadir, Abdul S; Baek, Jeong-Hwa

    2014-09-01

    We investigated the effects of high calorie and low calorie diets on skeletal integrity, and whether β-adrenergic blockade (BB) attenuates bone loss induced by dietary calorie alteration. Male 6-week-old C57BL/6 mice were assigned to either an ad-lib fed control diet (CON), a high calorie diet (HIGH), or a low calorie diet (LOW) group. In each diet group, mice were treated with either vehicle (VEH) or propranolol, a β-adrenergic antagonist. Over 12-weeks, β-blockade mitigated body weight and fat mass increases induced by the high calorie diet. Femoral trabecular bone mineral density and the expression levels of osteogenic marker genes in bone marrow cells were reduced in HIGHVEH and LOWVEH mice, and BB significantly attenuated this decline only in HIGH mice. In summary, the magnitude of bone loss induced by low calorie diet was greater than that caused by high calorie diet in growing mice, and β-blockade mitigated high calorie diet-induced bone loss.

  16. CD44 deficiency inhibits unloading-induced cortical bone loss through downregulation of osteoclast activity.

    Science.gov (United States)

    Li, Yuheng; Zhong, Guohui; Sun, Weijia; Zhao, Chengyang; Zhang, Pengfei; Song, Jinping; Zhao, Dingsheng; Jin, Xiaoyan; Li, Qi; Ling, Shukuan; Li, Yingxian

    2015-11-04

    The CD44 is cellular surface adhesion molecule that is involved in physiological processes such as hematopoiesis, lymphocyte homing and limb development. It plays an important role in a variety of cellular functions including adhesion, migration, invasion and survival. In bone tissue, CD44 is widely expressed in osteoblasts, osteoclasts and osteocytes. However, the mechanisms underlying its role in bone metabolism remain unclear. We found that CD44 expression was upregulated during osteoclastogenesis. CD44 deficiency in vitro significantly inhibited osteoclast activity and function by regulating the NF-κB/NFATc1-mediated pathway. In vivo, CD44 mRNA levels were significantly upregulated in osteoclasts isolated from the hindlimb of tail-suspended mice. CD44 deficiency can reduce osteoclast activity and counteract cortical bone loss in the hindlimb of unloaded mice. These results suggest that therapeutic inhibition of CD44 may protect from unloading induced bone loss by inhibiting osteoclast activity.

  17. Simulation analysis for effects of bone loss on acceleration tolerance of human lumbar vertebra

    Science.gov (United States)

    Ma, Honglei; Zhang, Feng; Zhu, Yu; Xiao, Yanhua; Wazir, Abrar

    2014-02-01

    The purpose of the present study was to analyze and predict the changes in acceleration tolerance of human vertebra as a result of bone loss caused by long-term space flight. A human L3-L4 vertebra FEM model was constructed, in which the cancellous bone was separated, and surrounding ligaments were also taken into account. The simulation results demonstrated that bone loss has more of an effect on the acceleration tolerance in x-direction. The results serve to aid in the creation of new acceleration tolerance standards, ensuring astronauts return home safely after long-term space flight. This study shows that more attention should be focused on the bone degradation of crew members and to create new protective designs for space capsules in the future.

  18. Sappanone A inhibits RANKL-induced osteoclastogenesis in BMMs and prevents inflammation-mediated bone loss.

    Science.gov (United States)

    Choo, Young-Yeon; Tran, Phuong Thao; Min, Byung-Sun; Kim, Okwha; Nguyen, Hai Dang; Kwon, Seung-Hae; Lee, Jeong-Hyung

    2017-11-01

    Receptor activator of nuclear factor-kB ligand (RANKL) is a key factor in the differentiation and activation of osteoclasts. Suppressing osteoclastogenesis is considered an effective therapeutic approach for bone-destructive diseases, such as osteoporosis and rheumatoid arthritis. Sappanone A (SPNA), a homoisoflavanone compound isolated from the heartwood of Caesalpinia sappan, has been reported to exert anti-inflammatory effects; however, the effects of SPNA on osteoclastogenesis have not been investigated. In the present study, we describe for the first time that SPNA inhibits RANKL-induced osteoclastogenesis in mouse bone marrow macrophages (BMMs) and suppresses inflammation-induced bone loss in a mouse model. SPNA inhibited the formation of osteoclasts from BMMs, osteoclast actin-ring formation, and bone resorption in a concentration-dependent manner. At the molecular level, SPNA significantly inhibited RANKL-induced activation of the AKT/glycogen synthase kinase-3β (GSK-3β) signaling pathway without affecting its activation of the mitogen-activated protein kinases (MAPKs) JNK, p38, and ERK. In addition, SPNA suppressed the induction of nuclear factor of activated T cells cytoplasmic 1 (NFATc1), which is a crucial transcription factor in osteoclast differentiation. As a result, SPNA decreased osteoclastogenesis-related marker gene expression, including CtsK, TRAP, dendritic cell-specific transmembrane protein (DC-STAMP), MMP-9 and osteoclast-associated receptor (OSCAR). In a mouse inflammatory bone loss model, SPNA significantly inhibited lipopolysaccharide (LPS)-induced bone loss by suppressing the number of osteoclasts. Taken together, these findings suggest that SPNA inhibits osteoclastogenesis and bone resorption by inhibiting the AKT/GSK-3β signaling pathway and may be a potential candidate compound for the prevention and/or treatment of inflammatory bone loss. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. ZP2307, a novel, cyclic PTH(1-17) analog that augments bone mass in ovariectomized rats

    DEFF Research Database (Denmark)

    Neerup, Trine Skovlund Ryge; Stahlhut, Martin; Petersen, Jørgen S

    2011-01-01

    Daily injections of human parathyroid hormone (1-34), hPTH(1-34), provide a highly effective treatment option for severe osteoporosis. However, PTH analogs shorter than 28 amino acids do not retain any bone augmenting potential. Here, we present ZP2307 ([Ac₅c¹, Aib³, Leu⁸, Gln¹⁰, Har¹¹, Ala¹², Trp......¹⁴, Asp¹⁷]PTH(1-17)-NH₂), a novel, chemically modified and cyclized hPTH(1-17) analog, that augments bone mass in ovariectomized, osteopenic rats. Subcutaneous administration of this structurally constrained, K¹³-D¹⁷ side-chain-to-side-chain cyclized peptide reversed bone loss and increased bone...... calcium levels in the ovariectomized rats. To our knowledge ZP2307 is the smallest PTH peptide analog known to exert augmentation of bone. Our findings suggest that ZP2307 has the potential to effectively augment bone mass over a broad dose range without a concomitant increase in the serum concentration...

  20. Recurrent Anterior Shoulder Instability With Combined Bone Loss: Treatment and Results With the Modified Latarjet Procedure.

    Science.gov (United States)

    Yang, Justin S; Mazzocca, Augustus D; Cote, Mark P; Edgar, Cory M; Arciero, Robert A

    2016-04-01

    Recurrent anterior glenohumeral dislocation in the setting of an engaging Hill-Sachs lesion is high. The Latarjet procedure has been well described for restoring glenohumeral stability in patients with >25% glenoid bone loss. However, the treatment for patients with combined humeral head and mild (Latarjet for patients with combined humeral and glenoid defects and compares the results for patients with ≤25% glenoid bone loss versus patients with >25% glenoid bone loss. The hypothesis was that the 2 groups would have equivalent subjective outcomes and recurrence rates. Cohort Study; Level of evidence, 3. Modified Latarjet was performed in 40 patients with recurrent anterior shoulder instability, engaging Hill-Sachs by examination confirmed with arthroscopy, and ≤25% anterior glenoid bone loss (group A). A second group of 12 patients were identified to have >25% glenoid bone loss with an engaging Hill-Sachs lesion (group B). The mean follow-up time was 3.5 years. All patients were assessed for their risk of recurrence using the Instability Severity Index score and Beighton score and had preoperative 3-dimensional imaging to assess humeral and glenoid bone loss. Single Assessment Numeric Evaluation (SANE), Western Ontario Shoulder Instability Index (WOSI), recurrence rate, radiographs, range of motion, and dynamometer strength were used to assess outcomes. A multivariate analysis was performed. Glenoid bone loss averaged 15% in group A compared with 34% in group B. Both groups had comparable WOSI scores (356 vs 475; P = .311). In multivariate analysis, the number of previous surgeries and Beighton score were directly correlated with WOSI score in Latarjet patients. The SANE score was better in group A (86 vs 77; P = .02). Group B experienced more loss of external rotation (9.2° vs 15.8°; P = .0001) and weaker thumbs-down abduction and external rotation strength (P .999) were similar for both groups. The complication rate was 25% for both groups. The modified

  1. Effect of hormone replacement therapy on the bone mass and urinary excretion of pyridinium cross-links

    Directory of Open Access Journals (Sweden)

    Dolores Perovano Pardini

    2000-01-01

    Full Text Available CONTEXT: The menopause accelerates bone loss and is associated with an increased bone turnover. Bone formation may be evaluated by several biochemical markers. However, the establishment of an accurate marker for bone resorption has been more difficult to achieve. OBJECTIVE: To study the effect of hormone replacement therapy (HRT on bone mass and on the markers of bone resorption: urinary excretion of pyridinoline and deoxypyridinoline. DESIGN: Cohort correlational study. SETTING: Academic referral center. SAMPLE: 53 post-menopausal women, aged 48-58 years. MAIN MEASUREMENTS: Urinary pyr and d-pyr were measured in fasting urine samples by spectrofluorometry after high performance liquid chromatography and corrected for creatinine excretion measured before treatment and after 1, 2, 4 and 12 months. Bone mineral density (BMD was measured by dual energy X-ray absorptiometry (DEXA before treatment and after 12 months of HRT. RESULTS: The BMD after HRT was about 4.7% (P < 0.0004; 2% (P < 0.002; and 3% (P < 0.01 higher than the basal values in lumbar spine, neck and trochanter respectively. There were no significant correlations between pyridinium cross-links and age, weight, menopause duration and BMD. The decrease in pyr and d-pyr was progressive after HRT, reaching 28.9% (P < 0.0002, and 42% (P < 0.0002 respectively after 1 year. CONCLUSIONS: Urinary pyridinoline and deoxypyridinoline excretion decreases early in hormone replacement therapy, reflecting a decrease in the bone resorption rate, and no correlation was observed with the bone mass evaluated by densitometry.

  2. Bone mineral content and bone metabolism in young adults with severe periodontitis

    DEFF Research Database (Denmark)

    Wowern von, N.; Westergaard, J.; Kollerup, G.

    2001-01-01

    Bone loss, bone markers, bone metabolism, bone mineral content, osteoporosis, severe periodontitis......Bone loss, bone markers, bone metabolism, bone mineral content, osteoporosis, severe periodontitis...

  3. High fat diet promotes achievement of peak bone mass in young rats

    International Nuclear Information System (INIS)

    Malvi, Parmanand; Piprode, Vikrant; Chaube, Balkrishna; Pote, Satish T.; Mittal, Monika; Chattopadhyay, Naibedya; Wani, Mohan R.; Bhat, Manoj Kumar

    2014-01-01

    Highlights: • High fat diet helps in achieving peak bone mass at younger age. • Shifting from high fat to normal diet normalizes obese parameters. • Bone parameters are sustained even after withdrawal of high fat diet. - Abstract: The relationship between obesity and bone is complex. Epidemiological studies demonstrate positive as well as negative correlation between obesity and bone health. In the present study, we investigated the impact of high fat diet-induced obesity on peak bone mass. After 9 months of feeding young rats with high fat diet, we observed obesity phenotype in rats with increased body weight, fat mass, serum triglycerides and cholesterol. There were significant increases in serum total alkaline phosphatase, bone mineral density and bone mineral content. By micro-computed tomography (μ-CT), we observed a trend of better trabecular bones with respect to their microarchitecture and geometry. This indicated that high fat diet helps in achieving peak bone mass and microstructure at younger age. We subsequently shifted rats from high fat diet to normal diet for 6 months and evaluated bone/obesity parameters. It was observed that after shifting rats from high fat diet to normal diet, fat mass, serum triglycerides and cholesterol were significantly decreased. Interestingly, the gain in bone mineral density, bone mineral content and trabecular bone parameters by HFD was retained even after body weight and obesity were normalized. These results suggest that fat rich diet during growth could accelerate achievement of peak bone mass that is sustainable even after withdrawal of high fat diet

  4. High fat diet promotes achievement of peak bone mass in young rats

    Energy Technology Data Exchange (ETDEWEB)

    Malvi, Parmanand; Piprode, Vikrant; Chaube, Balkrishna; Pote, Satish T. [National Centre for Cell Science, Savitribai Phule Pune University Campus, Ganeshkhind, Pune 411 007 (India); Mittal, Monika; Chattopadhyay, Naibedya [Division of Endocrinology and Center for Research in Anabolic Skeletal Targets in Health and Illness (ASTHI), CSIR-Central Drug Research Institute, Jankipuram Extension, Sitapur Road, Lucknow 226 031 (India); Wani, Mohan R. [National Centre for Cell Science, Savitribai Phule Pune University Campus, Ganeshkhind, Pune 411 007 (India); Bhat, Manoj Kumar, E-mail: manojkbhat@nccs.res.in [National Centre for Cell Science, Savitribai Phule Pune University Campus, Ganeshkhind, Pune 411 007 (India)

    2014-12-05

    Highlights: • High fat diet helps in achieving peak bone mass at younger age. • Shifting from high fat to normal diet normalizes obese parameters. • Bone parameters are sustained even after withdrawal of high fat diet. - Abstract: The relationship between obesity and bone is complex. Epidemiological studies demonstrate positive as well as negative correlation between obesity and bone health. In the present study, we investigated the impact of high fat diet-induced obesity on peak bone mass. After 9 months of feeding young rats with high fat diet, we observed obesity phenotype in rats with increased body weight, fat mass, serum triglycerides and cholesterol. There were significant increases in serum total alkaline phosphatase, bone mineral density and bone mineral content. By micro-computed tomography (μ-CT), we observed a trend of better trabecular bones with respect to their microarchitecture and geometry. This indicated that high fat diet helps in achieving peak bone mass and microstructure at younger age. We subsequently shifted rats from high fat diet to normal diet for 6 months and evaluated bone/obesity parameters. It was observed that after shifting rats from high fat diet to normal diet, fat mass, serum triglycerides and cholesterol were significantly decreased. Interestingly, the gain in bone mineral density, bone mineral content and trabecular bone parameters by HFD was retained even after body weight and obesity were normalized. These results suggest that fat rich diet during growth could accelerate achievement of peak bone mass that is sustainable even after withdrawal of high fat diet.

  5. Novel familial mutation of LRP5 causing high bone mass: Genetic analysis, clinical presentation, and characterization of bone matrix mineralization.

    Science.gov (United States)

    Roetzer, K M; Uyanik, G; Brehm, A; Zwerina, J; Zandieh, S; Czech, T; Roschger, P; Misof, B M; Klaushofer, K

    2018-02-01

    The Wnt signalling pathway is a critical regulator of bone mass and quality. Several heterozygous mutations in the LRP5 gene, a Wnt co-receptor, causing high bone mass (LRP5-HBM) have been described to date. The pathogenic mechanism is thought to be a gain-of-function caused by impaired inhibition of the canonical Wnt signalling pathway, thereby leading to increased bone formation. We report the cases of two affected family members, a 53-year-old mother and her 23-year-old daughter, with high bone mass (T-scores mother: lumbar spine 11.4, femoral neck 10.5; T-scores daughter: lumbar spine 5.4, femoral neck 8.7), increased calvarial thickness, and thickened cortices of the long bones but no history of fractures. Whereas the mother did not show any indications of the mutation, the daughter suffered from congenital hearing impairment resulting in cochlear implantation, recurrent facial palsy, and migraine. In addition, she had stenosis of the foramen magnum. In both individuals, we detected a novel heterozygous duplication of six basepairs in the LRP5 gene, resulting in an insertion of two amino acids, very likely associated with a gain-of-function. When the daughter had part of the occipital bone surgically removed, the bone sample was used for the visualization of bone lamellar structure and bone cells as well as the measurement of bone mineralization density distribution (BMDD). The bone sample revealed two distinctly different regions: an intra-cortical region with osteonal remodeling, typical osteonal lamellar orientation, associated with relatively higher heterogeneity of bone matrix mineralization, and another periosteal region devoid of bone remodeling, with parallel bone lamellae and lower heterogeneity of mineralization. In conclusion, we present data on bone tissue and material level from an LRP5-HBM patient with a novel mutation in the LRP5 gene. Our findings indicate normal morphology of osteoclasts and osteoblasts as well as normal mineralization in

  6. Andrographolide prevents human breast cancer-induced osteoclastic bone loss via attenuated RANKL signaling.

    Science.gov (United States)

    Zhai, Zanjing; Qu, Xinhua; Yan, Wei; Li, Haowei; Liu, Guangwang; Liu, Xuqiang; Tang, Tingting; Qin, An; Dai, Kerong

    2014-02-01

    Bone metastasis is a common and serious complication in advanced cancers such as breast cancer, prostate cancer, and multiple myeloma. Agents that prevent bone loss could be used to develop an alternative therapy for bone metastasis. RANKL, a member of the tumor necrosis factor superfamily, has been shown to play a significant role in cancer-associated bone loss. In this study, we examined the efficacy of the natural compound andrographolide (AP), a diterpenoid lactone isolated from the traditional Chinese and Indian medicinal plant Andrographis paniculata, in reducing breast cancer-induced osteolysis. AP prevented human breast cancer-induced bone loss by suppressing RANKL-mediated and human breast cancer cell-induced osteoclast differentiation. Molecular analysis revealed that AP prevented osteoclast function by inhibiting RANKL-induced NF-κB and ERK signaling pathway in lower dose (20 μM), as well as inducing apoptosis at higher dose (40 μM). Thus, AP is a potent inhibitor of breast cancer-induced bone metastasis.

  7. Asymptotically simple spacetimes and mass loss due to gravitational waves

    Science.gov (United States)

    Saw, Vee-Liem

    The cosmological constant Λ used to be a freedom in Einstein’s theory of general relativity (GR), where one had a proclivity to set it to zero purely for convenience. The signs of Λ or Λ being zero would describe universes with different properties. For instance, the conformal structure of spacetime directly depends on Λ: null infinity ℐ is a spacelike, null, or timelike hypersurface, if Λ > 0, Λ = 0, or Λ 0 in Einstein’s theory of GR. A quantity that depends on the conformal structure of spacetime, especially on the nature of ℐ, is the Bondi mass which in turn dictates the mass loss of an isolated gravitating system due to energy carried away by gravitational waves. This problem of extending the Bondi mass to a universe with Λ > 0 has spawned intense research activity over the past several years. Some aspects include a closer inspection on the conformal properties, working with linearization, attempts using a Hamiltonian formulation based on “linearized” asymptotic symmetries, as well as obtaining the general asymptotic solutions of de Sitter-like spacetimes. We consolidate on the progress thus far from the various approaches that have been undertaken, as well as discuss the current open problems and possible directions in this area.

  8. Determination of peak bone mass density and composition in low-income urban residents of metro Manila using isotope techniques

    International Nuclear Information System (INIS)

    Lim-Abrahan, M.A.V.; Guanzon, L.V.V.; De Guzman, A.M.; Villaruel, C.M.; Santos, F.

    1996-01-01

    Filipinos are predisposed to osteoporosis because of inadequate calcium in their diet early on in life, confounded by malnutrition, susceptibility to infectious diseases and their generally small body frame. And yet the problem of osteoporosis has not been properly addressed. The incidence of osteoporosis is not known since oftentimes it is established only once complications have set in. It is believed that osteoporosis poses a public health concern but its extent is not realized at present because of lack of local epidemiological data. This study aims to determine the bone mass density as a function of age among 210 screened and healthy volunteers coming from urban poor communities of Metro Manila over a 3-year period. A LUNAR DPX-L bone densitometry for dual X-ray photon absorptiometry will be used, with measurements taken on the spine and femur. It also aims to correlate factors such as nutritional intake, physical activity, lifestyle, sex and body mass index with that of bone mass density. Blood and urine samples will be obtained for biochemistry and hormonal radioimmunoassay examination. Statistical analysis will be done to com are differences within the group and to determine rate of bone loss as a function of age and sex. Plans for future research include the determination of trace element content in cortical bone and tooth samples from healthy living subjects. (author)

  9. Regulation of bone mass through pineal-derived melatonin-MT2 receptor pathway.

    Science.gov (United States)

    Sharan, Kunal; Lewis, Kirsty; Furukawa, Takahisa; Yadav, Vijay K

    2017-09-01

    Tryptophan, an essential amino acid through a series of enzymatic reactions gives rise to various metabolites, viz. serotonin and melatonin, that regulate distinct biological functions. We show here that tryptophan metabolism in the pineal gland favors bone mass accrual through production of melatonin, a pineal-derived neurohormone. Pineal gland-specific deletion of Tph1, the enzyme that catalyzes the first step in the melatonin biosynthesis lead to a decrease in melatonin levels and a low bone mass due to an isolated decrease in bone formation while bone resorption parameters remained unaffected. Skeletal analysis of the mice deficient in MT1 or MT2 melatonin receptors showed a low bone mass in MT2-/- mice while MT1-/- mice had a normal bone mass compared to the WT mice. This low bone mass in the MT2-/- mice was due to an isolated decrease in osteoblast numbers and bone formation. In vitro assays of the osteoblast cultures derived from the MT1-/- and MT2-/- mice showed a cell intrinsic defect in the proliferation, differentiation and mineralization abilities of MT2-/- osteoblasts compared to WT counterparts, and the mutant cells did not respond to melatonin addition. Finally, we demonstrate that daily oral administration of melatonin can increase bone accrual during growth and can cure ovariectomy-induced structural and functional degeneration of bone by specifically increasing bone formation. By identifying pineal-derived melatonin as a regulator of bone mass through MT2 receptors, this study expands the role played by tryptophan derivatives in the regulation of bone mass and underscores its therapeutic relevance in postmenopausal osteoporosis. © 2017 The Authors. Journal of Pineal Research Published by John Wiley & Sons Ltd.

  10. Effect of Cistanches Herba Aqueous Extract on Bone Loss in Ovariectomized Rat

    Directory of Open Access Journals (Sweden)

    Zaiguo Huang

    2011-08-01

    Full Text Available To assess the ability of traditional Chinese medicine Cistanches Herba extract (CHE to prevent bone loss in the ovariectomized (OVX rat, Cistanches Herba extract (CHE was administered intragastrically to the rats. Female rats were anesthetized with pentobarbital sodium (40 mg kg−1, i.p., and their ovaries were removed bilaterally. The rats in the sham-operated group were anesthetized, laparotomized, and sutured without removing their ovaries. After 1 week of recovery from surgery, the OVX rats were randomly divided into three groups and orally treated with H2O (OVX group or CHE (100 or 200 mg kg−1 daily for 3 months. The sham-operated group (n = 8 was orally treated with H2O. After 3 months, the total body bone mineral density (BMD, bone mineral content (BMC, Bone biomechanical index, blood mineral levels and blood antioxidant enzymes activities were examined in sham-operated, ovariectomized and Cistanches Herba extract treated rats. Results showed that Cistanches Herba extract treatment significantly dose-dependently enhanced bone mineral density (BMD, bone mineral content (BMC, maximum load, displacement at maximum load, stress at maximum load, load at auto break, displacement at auto break, and stress at auto break, and blood antioxidant enzymes activities, decreased blood Ca, Zn and Cu levels compared to the OVX group. This experiment demonstrates that the administration of Cistanches Herba extract to ovariectomized rats reverses bone loss and prevents osteoporosis.

  11. Mandibular atrophy and metabolic bone loss. Mandibular ridge augmentation by combined sandwich-visor osteotomy and resorption related to metabolic bone state

    NARCIS (Netherlands)

    Bras, J.; van Ooij, C. P.; van den Akker, H. P.

    1985-01-01

    22 edentulous women, 11 with and 11 without signs of metabolic bone loss were treated by a combined sandwich-visor osteotomy. Longitudinal studies showed a higher rate of resorption in women with radiographic signs of metabolic bone loss. The analysis was based upon lateral cephalometry

  12. Mandibular atrophy and metabolic bone loss. Mandibular ridge augmentation by combined sandwich-visor osteotomy and resorption related to metabolic bone state. A 5-year follow-up

    NARCIS (Netherlands)

    Habets, L. L.; Bras, J.; van den Akker, H. P.; Borgmeyer-Hoelen, A. M.; van Ooij, C. P.

    1987-01-01

    92 patients, 31 with and 61 without signs of metabolic bone loss, were treated with a combined sandwich-visor osteotomy. A 5-year follow-up showed a significantly higher rate of resorption in patients with radiographic signs of metabolic bone loss. The analysis was based upon lateral cephalometry

  13. Stage I Breast Cancer and Bone Mass in Older Women

    National Research Council Canada - National Science Library

    Schneider, Diane

    2001-01-01

    The specific aims of the study are I) to assess the bone mineral density of women 65 years of age and older with breast cancer in comparison with the bone mineral density of same aged women with normal mammograms; 2...

  14. Stage 1 Breast Cancer and Bone Mass in Older Women

    National Research Council Canada - National Science Library

    Schneider, Diane

    2002-01-01

    The specific aims of the study are 1) to assess the bone mineral density of women 65 years of age and older with breast cancer in comparison with the bone mineral density of same aged women with normal mammograms; 2...

  15. Parallels between Nutrition and Physical Activity: Research Questions in Development of Peak Bone Mass

    Science.gov (United States)

    Weaver, Connie M.

    2015-01-01

    Lifestyle choices are attributed to 40% to 60% of adult peak bone mass. The National Osteoporosis Foundation (NOF) sought to update its 2000 consensus statement on peak bone mass and partnered with the American Society for Nutrition, which, in turn, charged a 9-member writing committee with using a systematic review approach to update the previous…

  16. Mucosal inflammation and incidence of crestal bone loss among implant patients: a 10-year study.

    Science.gov (United States)

    Cecchinato, Denis; Parpaiola, Andrea; Lindhe, Jan

    2014-07-01

    The objective of this prospective study was to determine the prevalence and incidence of marginal bone loss and, in addition, peri-implantitis in subjects and implant sites after 10 years in function. One hundred and thirty-three subjects with a total of 407 implants that had been in function for about 5 years attended a follow-up visit in 2007 (visit 2; V2). 100 of the 133 subjects returned for a new clinical and radiographic examination in 2012 (visit 3; V3). The clinical examination included assessment of "bleeding on probing" (BoP+) and "probing pocket depth." Subjects with implant sites that in the radiograph exhibited crater-shaped marginal bone loss of >0.5 mm were identified as losers. During the interval between V2 and V3 (about 5 years), 13 implants in 7 subjects exhibited progressive bone loss and were removed. The overall amount of crestal bone loss that had occurred at the remaining implants between visit 1 (V1; ≥1 year of loading) and V3 (10 years) was small (0.36 ± 1.4 mm). The bone-level reduction was twice as great between V2 and V3 as between V1 and V2. Forty subjects and 75 (26%) implant sites exhibited marginal bone loss of >0.5 mm between V1 and V3. In the interval between V2 and V3, 37 new implant sites lost significant amounts of bone. During the entire 10-year period (V1-V3), 12% of patients and 5% of implants displayed signs of peri-implantitis (bone loss >0.5 mm, BoP+, PPD ≥6 mm), while in the V2-V3 interval, the corresponding numbers were 10% (patients) and 4% (implant sites). Sites with marginal bone loss of ≥1 mm were not common among implant patients. Peri-implantitis occurred in about 10% of patients and 4% of implant sites. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  17. Use of 3D MR reconstructions in the evaluation of glenoid bone loss: a clinical study

    International Nuclear Information System (INIS)

    Gyftopoulos, Soterios; Beltran, Luis S.; Yemin, Avner; Recht, Michael P.; Strauss, Eric; Meislin, Robert; Jazrawi, Laith

    2014-01-01

    To assess the ability of 3D MR shoulder reconstructions to accurately quantify glenoid bone loss in the clinical setting using findings at the time of arthroscopy as the gold standard. Retrospective review of patients with MR shoulder studies that included 3D MR reconstructions (3D MR) produced using an axial Dixon 3D-T1W-FLASH sequence at our institution was conducted with the following inclusion criteria: history of anterior shoulder dislocation, arthroscopy (OR) performed within 6 months of the MRI, and an estimate of glenoid bone loss made in the OR using the bare-spot method. Two musculoskeletal radiologists produced estimates of bone loss along the glenoid width, measured in mm and %, on 3D MR using the best-fit circle method, which were then compared to the OR measurements. There were a total of 15 patients (13 men, two women; mean age, 28, range, 19-51 years). There was no significant difference, on average, between the MRI (mean 3.4 mm/12.6 %; range, 0-30 %) and OR (mean, 12.7 %; range, 0-30 %) measurements of glenoid bone loss (p = 0.767). A 95 % confidence interval for the mean absolute error extended from 0.45-2.21 %, implying that, when averaged over all patients, the true mean absolute error of the MRI measurements relative to the OR measurements is expected to be less than 2.21 %. Inter-reader agreement between the two readers had an IC of 0.92 and CC of 0.90 in terms of percentage of bone loss. 3D MR reconstructions of the shoulder can be used to accurately measure glenoid bone loss. (orig.)

  18. Comparison between inverted and unprocessed digitized radiographic imaging in periodontal bone loss measurements

    Directory of Open Access Journals (Sweden)

    Gulnara Scaf

    2007-12-01

    Full Text Available The advances in digital imaging technology in dentistry have provided an alternative to film-based radiography and have given new options to detect periodontal bone loss. The purpose of this study was to compare inverted and unprocessed digitized radiographic imaging in periodontal bone loss measurements. Thirty-five film-based periapical radiographs of patients suffering from moderate to advanced untreated periodontal bone loss associated to lower premolar and molars was selected from the department files, with 40 bone loss areas. The film-based radiographs were digitized with a flatbed scanner with a transparency and radiograph adapter used for transilluminating the radiograph imaging. Digitization was performed at 600 dpi and in gray scale. The images were digitized using Image Tool software by applying image inversion, that is, transformation of radiopaque structures into radiolucent structures and vice-versa. The digital data were saved as JPEG files. The images were displayed on a 15-inch and 24-bit video monitor under reduced room lighting. One calibrated examiner performed all radiographic measurements, three times, from the cementoenamel junction to the most apical extension of the bone loss, in both types of image (inverted and unprocessed. Brightness and contrast were adjusted according to the examiner's individual demand. Intraclass correlation coefficient was used to compare the measurements from both types of images. The means of radiographic measurements, in mm, for inverted and unprocessed digitized imaging were 6.4485 and 6.3790, respectively. The intraclass correlation coefficient was significant (0.99 The inverted and unprocessed digitized radiographic images were reliable and there was no difference in the diagnostic accuracy between these images regarding periodontal bone loss measurements.

  19. A cross-sectional study on the prevalence of marginal bone loss among implant patients.

    Science.gov (United States)

    Cecchinato, Denis; Parpaiola, Andrea; Lindhe, Jan

    2013-01-01

    The aim of the present cross-sectional retrospective study was to determine bone loss in a sample of subjects restored with implant-supported prostheses and the prevalence and severity of peri-implantitis in a sub-sample. A total of 139 patients who had attended a follow-up visit in 2007 were considered for inclusion. Subjects with implants that had been in function for less than 3 years or had poor quality radiographs were excluded. The final study population comprised 133 subjects with a total of 407 implants. Radiographic measurements identified subjects who had ≥1 implant site exhibiting marginal bone loss of >0.5 mm; 40 subjects met this criterion and were recalled for a clinical examination. Of the 40 subjects that were recalled for the clinical examination, 30 attended. The following parameters were recorded at mesial, distal, buccal, and lingual/palatal aspects of all implants: oral hygiene standard (plaque), bleeding on probing, probing pocket depth (PPD). The mean interval between the baseline (1-year post-loading) and the follow-up radiographs was 4.8 ± 2.3 years. In the total subject sample (133 subjects and 407 implants), the mean amount of marginal bone loss that had occurred was 0.2 ± 1.2 mm. Ninety-three subjects with 246 implant sites exhibited no bone level alteration (group A), whereas 40 subjects with 161 implant sites (group B) displayed marginal bone loss of >0.5 mm at ≥1 implant (loser site). Sixty-eight implant sites in group B exhibited bone loss of >0.5 mm. However, only 20% of subjects and 11% of sites had lost >1 mm marginal bone, and 8% of subjects and 4% of sites had lost >2 mm bone. The total amount of bone loss that had occurred in group B was (i) 0.88 ± 1.5 mm and (ii) among the loser sites 2.1 ± 1.4 mm. Thirty subjects from group B were exposed to a clinical examination; out of 37 sites with bone loss >0.5 mm in this subgroup, 29 sites had a PPD value of ≥4 mm. Marginal bone loss (>0.5 mm) at implants

  20. Bone degradation machinery of osteoclasts: An HIV-1 target that contributes to bone loss.

    Science.gov (United States)

    Raynaud-Messina, Brigitte; Bracq, Lucie; Dupont, Maeva; Souriant, Shanti; Usmani, Shariq M; Proag, Amsha; Pingris, Karine; Soldan, Vanessa; Thibault, Christophe; Capilla, Florence; Al Saati, Talal; Gennero, Isabelle; Jurdic, Pierre; Jolicoeur, Paul; Davignon, Jean-Luc; Mempel, Thorsten R; Benichou, Serge; Maridonneau-Parini, Isabelle; Vérollet, Christel

    2018-03-13

    Bone deficits are frequent in HIV-1-infected patients. We report here that osteoclasts, the cells specialized in bone resorption, are infected by HIV-1 in vivo in humanized mice and ex vivo in human joint biopsies. In vitro, infection of human osteoclasts occurs at different stages of osteoclastogenesis via cell-free viruses and, more efficiently, by transfer from infected T cells. HIV-1 infection markedly enhances adhesion and osteolytic activity of human osteoclasts by modifying the structure and function of the sealing zone, the osteoclast-specific bone degradation machinery. Indeed, the sealing zone is broader due to F-actin enrichment of its basal units (i.e., the podosomes). The viral protein Nef is involved in all HIV-1-induced effects partly through the activation of Src, a regulator of podosomes and of their assembly as a sealing zone. Supporting these results, Nef-transgenic mice exhibit an increased osteoclast density and bone defects, and osteoclasts derived from these animals display high osteolytic activity. Altogether, our study evidences osteoclasts as host cells for HIV-1 and their pathological contribution to bone disorders induced by this virus, in part via Nef.

  1. Lean Mass Appears to Be More Strongly Associated with Bone Health than Fat Mass in Urban Black South African Women.

    Science.gov (United States)

    Sotunde, O F; Kruger, H S; Wright, H H; Havemann-Nel, L; Kruger, I M; Wentzel-Viljoen, E; Kruger, A; Tieland, M

    2015-06-01

    To examine the association between body composition (fat mass, lean mass and body mass index, BMI) and bone health (bone mineral density, BMD and fracture risk) in urban black South African women. A cross sectional study examining associations between body composition, dietary intake (food frequency questionnaire), habitual physical activity (Activity energy expenditure (AEE) measured using an accelerometer with combined heart rate monitor and physical activity questionnaire) and bone health (BMD using dual-energy X ray absorptiometry, DXA and fracture risk). Urban community dwellers from Ikageng in the North-West Province of South Africa. One hundred and eighty nine (189) healthy postmenopausal women aged ≥43 years. Fat mass and lean mass were significantly associated with BMD and fracture risk when adjusted for potential confounders. However, lean mass and not fat mass remained significantly associated with femoral neck BMD (β = 0.49, p South African women. Our finding suggests that increasing lean mass rather than fat mass is beneficial to bone health. Our study emphasises the importance of positive lifestyle changes, intake of calcium from dairy and adequate weight to maintain and improve bone health of postmenopausal women.

  2. Decreased bone turnover with balanced resorption and formation prevent cortical bone loss during disuse (hibernation) in grizzly bears (Ursus arctos horribilis).

    Science.gov (United States)

    McGee, Meghan E; Maki, Aaron J; Johnson, Steven E; Nelson, O Lynne; Robbins, Charles T; Donahue, Seth W

    2008-02-01

    Disuse uncouples bone formation from resorption, leading to increased porosity, decreased bone geometrical properties, and decreased bone mineral content which compromises bone mechanical properties and increases fracture risk. However, black bear bone properties are not adversely affected by aging despite annual periods of disuse (i.e., hibernation), which suggests that bears either prevent bone loss during disuse or lose bone and subsequently recover it at a faster rate than other animals. Here we show decreased cortical bone turnover during hibernation with balanced formation and resorption in grizzly bear femurs. Hibernating grizzly bear femurs were less porous and more mineralized, and did not demonstrate any changes in cortical bone geometry or whole bone mechanical properties compared to active grizzly bear femurs. The activation frequency of intracortical remodeling was 75% lower during hibernation than during periods of physical activity, but the normalized mineral apposition rate was unchanged. These data indicate that bone turnover decreases during hibernation, but osteons continue to refill at normal rates. There were no changes in regional variation of porosity, geometry, or remodeling indices in femurs from hibernating bears, indicating that hibernation did not preferentially affect one region of the cortex. Thus, grizzly bears prevent bone loss during disuse by decreasing bone turnover and maintaining balanced formation and resorption, which preserves bone structure and strength. These results support the idea that bears possess a biological mechanism to prevent disuse osteoporosis.

  3. Changes in bone marrow lesions in response to weight-loss in obese knee osteoarthritis patients

    DEFF Research Database (Denmark)

    Gudbergsen, Henrik; Boesen, Mikael; Christensen, Robin

    2013-01-01

    are related to the future degeneration of the knee joint as well as prevalent clinical symptoms. The aim of this study was to investigate the changes in BMLs after a 16-week weight-loss period in obese subjects with KOA and relate changes in BMLs to the effects of weight-loss on clinical symptoms.......Patients are susceptible for knee osteoarthritis (KOA) with increasing age and obesity and KOA is expected to become a major disabling disease in the future. An important feature of KOA on magnetic resonance imaging (MRI) is changes in the subchondral bone, bone marrow lesions (BMLs), which...

  4. Prevention of Bone Loss after Acute SCI by Zoledronic Acid: Durability, Effect on Bone Strength, and Use of Biomarkers to Guide Therapy

    Science.gov (United States)

    2016-10-01

    Bone Loss after Acute SCI by Zoledronic Acid: Durability, Effect on Bone Strength, and Use of Biomarkers to Guide Therapy 5b. GRANT NUMBER W81XWH-14...duration of its effects and the value of using biomarkers to guide therapy. Data collection ( bone imaging and biomarkers) occurs at baseline and after 3...the durability of response to zoledronic acid and the utility of serum bone markers to guide therapeutic decision making. DXA imaging, CT imaging

  5. Insulin Resistance Is Associated With Smaller Cortical Bone Size in Nondiabetic Men at the Age of Peak Bone Mass.

    Science.gov (United States)

    Verroken, Charlotte; Zmierczak, Hans-Georg; Goemaere, Stefan; Kaufman, Jean-Marc; Lapauw, Bruno

    2017-06-01

    In type 2 diabetes mellitus, fracture risk is increased despite preserved areal bone mineral density. Although this apparent paradox may in part be explained by insulin resistance affecting bone structure and/or material properties, few studies have investigated the association between insulin resistance and bone geometry. We aimed to explore this association in a cohort of nondiabetic men at the age of peak bone mass. Nine hundred ninety-six nondiabetic men aged 25 to 45 years were recruited in a cross-sectional, population-based sibling pair study at a university research center. Insulin resistance was evaluated using the homeostasis model assessment of insulin resistance (HOMA-IR), with insulin and glucose measured from fasting serum samples. Bone geometry was assessed using peripheral quantitative computed tomography at the distal radius and the radial and tibial shafts. In age-, height-, and weight-adjusted analyses, HOMA-IR was inversely associated with trabecular area at the distal radius and with cortical area, periosteal and endosteal circumference, and polar strength strain index at the radial and tibial shafts (β ≤ -0.13, P insulin-like growth factor 1, or sex steroid levels. In this cohort of nondiabetic men at the age of peak bone mass, insulin resistance is inversely associated with trabecular and cortical bone size. These associations persist after adjustment for body composition, muscle size or function, or sex steroid levels, suggesting an independent effect of insulin resistance on bone geometry. Copyright © 2017 Endocrine Society

  6. High-impact exercise in rats prior to and during suspension can prevent bone loss

    International Nuclear Information System (INIS)

    Yanagihara, G.R.; Paiva, A.G.; Gasparini, G.A.; Macedo, A.P.; Frighetto, P.D.; Volpon, J.B.; Shimano, A.C.

    2016-01-01

    High-impact exercise has been considered an important method for treating bone loss in osteopenic experimental models. In this study, we investigated the effects of osteopenia caused by inactivity in femora and tibiae of rats subjected to jump training using the rat tail suspension model. Eight-week-old female Wistar rats were divided into five groups (n=10 each group): jump training for 2 weeks before suspension and training during 3 weeks of suspension; jump training for 2 weeks before suspension; jump training only during suspension; suspension without any training; and a control group. The exercise protocol consisted of 20 jumps/day, 5 days/week, with a jump height of 40 cm. The bone mineral density of the femora and tibiae was measured by double energy X-ray absorptiometry and the same bones were evaluated by mechanical tests. Bone microarchitecture was evaluated by scanning electron microscopy. One-way ANOVA was used to compare groups. Significance was determined as P<0.05. Regarding bone mineral density, mechanical properties and bone microarchitecture, the beneficial effects were greater in the bones of animals subjected to pre-suspension training and subsequently to training during suspension, compared with the bones of animals subjected to pre-suspension training or to training during suspension. Our results indicate that a period of high impact exercise prior to tail suspension in rats can prevent the installation of osteopenia if there is also training during the tail suspension

  7. High-impact exercise in rats prior to and during suspension can prevent bone loss

    Energy Technology Data Exchange (ETDEWEB)

    Yanagihara, G.R.; Paiva, A.G.; Gasparini, G.A.; Macedo, A.P. [Laboratório de Bioengenharia, Departamento de Biomecânica, Medicina e Reabilitação do Aparelho Locomotor, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP (Brazil); Frighetto, P.D. [Instituto Federal de Educação, Ciência e Tecnologia de São Paulo, São Paulo, SP (Brazil); Volpon, J.B.; Shimano, A.C. [Laboratório de Bioengenharia, Departamento de Biomecânica, Medicina e Reabilitação do Aparelho Locomotor, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP (Brazil)

    2016-02-02

    High-impact exercise has been considered an important method for treating bone loss in osteopenic experimental models. In this study, we investigated the effects of osteopenia caused by inactivity in femora and tibiae of rats subjected to jump training using the rat tail suspension model. Eight-week-old female Wistar rats were divided into five groups (n=10 each group): jump training for 2 weeks before suspension and training during 3 weeks of suspension; jump training for 2 weeks before suspension; jump training only during suspension; suspension without any training; and a control group. The exercise protocol consisted of 20 jumps/day, 5 days/week, with a jump height of 40 cm. The bone mineral density of the femora and tibiae was measured by double energy X-ray absorptiometry and the same bones were evaluated by mechanical tests. Bone microarchitecture was evaluated by scanning electron microscopy. One-way ANOVA was used to compare groups. Significance was determined as P<0.05. Regarding bone mineral density, mechanical properties and bone microarchitecture, the beneficial effects were greater in the bones of animals subjected to pre-suspension training and subsequently to training during suspension, compared with the bones of animals subjected to pre-suspension training or to training during suspension. Our results indicate that a period of high impact exercise prior to tail suspension in rats can prevent the installation of osteopenia if there is also training during the tail suspension.

  8. Endogenous opioids regulate alveolar bone loss in a periodontal disease model.

    Science.gov (United States)

    Queiroz-Junior, Celso M; Maltos, Kátia L M; Pacheco, Daniela F; Silva, Tarcília Aparecida; Albergaria, Juliano D S; Pacheco, Cinthia M F

    2013-10-06

    The anti-inflammatory effects of exogenous opioid compounds have been demonstrated in several conditions. Nevertheless, the function of endogenous opioid peptides released by the host during inflammatory processes deserves further characterization. The aim of this study was to verify whether endogenous opioids are involved in the progression of the inflammatory alveolar bone loss induced by ligature in rats. The experimental model of periodontal disease (PD) induced by ligature in rats was used throughout the study. A silk ligature was placed around the 2nd upper molar of male Holtzman rats, for 7 days. Rats received different doses of either the non-selective opioid antagonist naloxone or vehicle, locally into the afflicted gingival tissue, from the 3rd to the 5th day after ligature placement. In the 7th experimental day, rats were euthanized and their maxillae were collected for evaluation of alveolar bone and fiber attachment loss, presence of neutrophils (myeloperoxidase assay), osteoclast amount, and levels of cytokines IL-6, TNF-α, IL-8 and IL-10 in periodontal tissues. Naloxone increased alveolar bone loss significantly, in a dose-dependent manner, in relation to vehicle-treated rats. In contrast, the opioid antagonist did not affect the loss of fiber attachment. The treatment with naloxone also induced a significant increase in myeloperoxidase levels, osteoclast number and cytokines in periodontal tissues of rats with ligature-induced PD. Endogenous opioids protect the host from the progression of inflammatory alveolar bone loss that occurs in chronic periodontitis. © 2013.

  9. Bone loss during long term space flight is prevented by the application of a short term impulsive mechanical stimulus

    Science.gov (United States)

    Goodship, A. E.; Cunningham, J. L.; Oganov, V.; Darling, J.; Miles, A. W.; Owen, G. W.

    In long term space flight, the mechanical forces applied to the skeleton are substantially reduced and are altered in character. This reduced skeletal loading results in a reduction in bone mass. Exercise techmques currently used in space can maintain muscle mass but the mechanical stimulus provided by this exercise does not prevent bone loss. By applying an external impulsive load for a short period each day, which is intended to mimic the heel strike transient, to the lower limb of an astronaut during a long term space flight (5 months), this study tests the hypothesis that the bone cells can be activated by an appropriate external mechanical stimulus to maintain bone mass throughout prolonged periods of weightlessness. A mechanical loading device was developed to produce a loading of the os-calcis similar to that observed during the heel strike transient. The device is activated by the astronaut to provide a transient load to the heel of one leg whilst providing an equivalent exercising load to the other leg. During the EUROMIR95 mission on the MIR space station, an astronaut used this device for a short period daily throughout the duration of the mission. Pre- and post-flight measurements of bone mineral density (BMD) of the os-calcis and femoral neck of the astronaut were made to determine the efficacy of the device in preventing loss of bone mineral during the mission. On the os-calcis which received the mechanical stimulus, BMD was maintained throughout the period of the flight, while it was reduced by up to 7% on the os-calcis which received no stimulus. Post-flight, BMD in both the stimulated and non-stimulated os-calcis reduces, the extent of this reduction however is less in the stimulated os-calcis. For the femoral neck, the mechanical Stimulation does not produce a positive effect. On the os-calcis which received the mechanical stimulus, BMD was maintained throughout the period of the flight, while it was reduced by up to 7% on the os-calcis which

  10. Delta progradation in Greenland driven by increasing glacial mass loss

    DEFF Research Database (Denmark)

    Bendixen, Mette; Iversen, Lars Lonsmann; Bjork, Anders Anker

    2017-01-01

    Climate changes are pronounced in Arctic regions and increase the vulnerability of the Arctic coastal zone(1). For example, increases in melting of the Greenland Ice Sheet and reductions in sea ice and permafrost distribution are likely to alter coastal morphodynamics. The deltas of Greenland...... of erosion and accretion along the large deltas of the main rivers in the Arctic5-7. Our results improve the understanding of Arctic coastal evolution in a changing climate, and reveal the impacts on coastal areas of increasing ice mass loss and the associated freshwater runoff and lengthening of open...... are largely unaffected by human activity, but increased freshwater runoff and sediment fluxes may increase the size of the deltas, whereas increased wave activity in ice-free periods could reduce their size, with the net impact being unclear until now. Here we show that southwestern Greenland deltas were...

  11. Alpha-1 Antitrypsin Gene Therapy Ameliorates Bone Loss in Ovariectomy-Induced Osteoporosis Mouse Model.

    Science.gov (United States)

    Akbar, Mohammad Ahsanul; Cao, Jay J; Lu, Yuanqing; Nardo, David; Chen, Mong-Jen; Elshikha, Ahmed S; Ahamed, Rubina; Brantly, Mark; Holliday, L Shannon; Song, Sihong

    2016-09-01

    Osteoporosis is a major healthcare burden affecting mostly postmenopausal women characterized by compromised bone strength and increased risk of fragility fracture. Although pathogenesis of this disease is complex, elevated proinflammatory cytokine production is clearly involved in bone loss at menopause. Therefore, anti-inflammatory strategies hold a great potential for the prevention of postmenopausal osteoporosis. In this study, we investigated the effect of gene therapy of recombinant adeno-associated virus (rAAV)-mediated human alpha-1 antitrypsin (hAAT), a multifunctional protein that has anti-inflammatory property, on bone loss in an ovariectomy-induced osteoporosis mouse model. Adult ovariectomized (OVX) mice were intraperitoneally (i.p.) injected with hAAT (protein therapy), rAAV8-CB-hAAT (gene therapy), or phosphate buffer saline (PBS). Age-matched and sham-operated animals were used as controls. Eight weeks after the treatment, animals were sacrificed and bone-related biomarkers and vertebral bone structure were evaluated. Results showed that hAAT gene therapy significantly decreased serum IL-6 level and receptor activator of NF-κB (RANK) gene expression in bone. Importantly, hAAT gene therapy increased bone volume/total volume and decreased structure model index (SMI) compared to PBS injection in OVX mice. These results demonstrate that hAAT gene therapy by rAAV vector efficiently mitigates bone loss possibly through inhibition of proinflammatory cytokine IL-6 and RANK gene expression. Considering the safety profile of hAAT and rAAV vector in humans, our results provide a new alternative for the treatment of osteoporosis.

  12. Anti-inflammatory and antiresorptive effects of Calendula officinalis on inflammatory bone loss in rats.

    Science.gov (United States)

    Alexandre, Joanna Trycia M; Sousa, Luzia Hermínia Teixeira; Lisboa, Mario Roberto Pontes; Furlaneto, Flávia A C; do Val, Danielle Rocha; Marques, Mirna; Vasconcelos, Hellíada C; de Melo, Iracema Matos; Leitão, Renata; Castro Brito, Gerly Anne; Goes, Paula

    2017-12-29

    The aim of this work was to evaluate the anti-inflammatory and antiresorptive effects of Calendula officinalis (CLO) on alveolar bone loss (ABL) in rats. Male Wistar rats were subjected to ABL by ligature with nylon thread around the second upper left molar. The contralateral hemimaxillae were used as control. Rats received saline solution (SAL) or CLO (10, 30, or 90 mg/kg) 30 min before ligature and daily until the 11th day. The maxillae were removed and prepared for macroscopic, radiographic, micro-tomographic, histopathologic, histometric analysis, and immunohistochemical localization of receptor activator of nuclear factor kappa-B ligand (RANKL) and osteoprotegerin (OPG). The gingival tissues were used to quantify the myeloperoxidase (MPO) activity, tumor necrosis factor-alpha (TNF-α), and interleukin-1β (IL-1β) concentrations by ELISA. Blood samples were collected for leukogram and to evaluate the bone-specific alkaline phosphatase (BALP) activity and serum levels of aspartate and alanine transaminases (AST/ALT). The bone loss induced by 11 days of ligature induced bone loss, reduced levels of BALP, leukocyte infiltration, increased MPO activity, gingival concentrations of TNF-α and IL-1β, and RANKL while reduced OPG immunoexpressions in the periodontal tissue and leukocytosis. Of the CLO, 90 mg/kg reduced bone loss, neutrophilia, the levels of pro-inflammatory mediators, and RANKL expression, while it increased OPG immunopositive cells and BALP serum levels, when compared to SAL. CLO did not affect either kidney or liver function, indicated by serum AST/ALT levels. The present data suggests that CLO reduced inflammatory bone resorption in experimental periodontitis, which may be mediated by its anti-inflammatory properties and its effects on bone metabolism. CLO can be a potential therapeutical adjuvant in the treatment of periodontitis.

  13. Women Build Long Bones With Less Cortical Mass Relative to Body Size and Bone Size Compared With Men.

    Science.gov (United States)

    Jepsen, Karl J; Bigelow, Erin M R; Schlecht, Stephen H

    2015-08-01

    The twofold greater lifetime risk of fracturing a bone for white women compared with white men and black women has been attributed in part to differences in how the skeletal system accumulates bone mass during growth. On average, women build more slender long bones with less cortical area compared with men. Although slender bones are known to have a naturally lower cortical area compared with wider bones, it remains unclear whether the relatively lower cortical area of women is consistent with their increased slenderness or is reduced beyond that expected for the sex-specific differences in bone size and body size. Whether this sexual dimorphism is consistent with ethnic background and is recapitulated in the widely used mouse model also remains unclear. We asked (1) do black women build bones with reduced cortical area compared with black men; (2) do white women build bones with reduced cortical area compared with white men; and (3) do female mice build bones with reduced cortical area compared with male mice? Bone strength and cross-sectional morphology of adult human and mouse bone were calculated from quantitative CT images of the femoral midshaft. The data were tested for normality and regression analyses were used to test for differences in cortical area between men and women after adjusting for body size and bone size by general linear model (GLM). Linear regression analysis showed that the femurs of black women had 11% lower cortical area compared with those of black men after adjusting for body size and bone size (women: mean=357.7 mm2; 95% confidence interval [CI], 347.9-367.5 mm2; men: mean=400.1 mm2; 95% CI, 391.5-408.7 mm2; effect size=1.2; pbone size (women: mean=350.1 mm2; 95% CI, 340.4-359.8 mm2; men: mean=394.3 mm2; 95% CI, 386.5-402.1 mm2; effect size=1.3; pbone size (female: mean=0.73 mm2; 95% CI, 0.71-0.74 mm2; male: mean=0.70 mm2; 95% CI, 0.68-0.71 mm2; effect size=0.74; p=0.04, GLM). Female femurs are not simply a more slender version of male

  14. Exercise Countermeasures for Bone Loss During Space Flight: A Method for the Study of Ground Reaction Forces and their Implications for Bone Strain

    Science.gov (United States)

    Peterman, M.; McCrory, J. L.; Sharkey, N. A.; Piazza, S.; Cavanagh, P. R.

    1999-01-01

    Effective countermeasures to prevent loss of bone mineral during long duration space flight remain elusive. Despite an exercise program on MIR flights, the data from LeBlanc et al. (1996) indicated that there was still a mean rate of loss of bone mineral density in the proximal femur of 1.58% per month (n=18, flight duration 4 - 14.4 months). The specific mechanisms regulating bone mass are not known, but most investigators agree that bone maintenance is largely dependent upon mechanical demand and the resultant local bone strains. A plausible hypothesis is that bone loss during space flight, such as that reported by LeBlanc et al. (1996), may result from failure to effectively load the skeleton in order to generate localized bone strains of sufficient magnitude to prevent disuse osteoporosis. A variety of methods have been proposed to simulate locomotor exercise in reduced gravity. In such simulations, and in an actual microgravity environment, a gravity replacement load (GRL) must always be added to return the exercising subject to the support surface and the resulting skeletal load is critically dependent upon the magnitude of the GRL. To our knowledge, GRLs during orbital flight have only been measured once (on STS 81) and it is likely that most or all prior treadmill exercise in space has used GRLs that were less than one body weight. McCrory (1997) has shown that subjects walking and running in simulated zero-G can tolerate GRLs of 1 if an appropriate harness is used. Several investigators have attempted to measure in vivo strains and forces in the bones of humans, but have faced ethical and technical limitations. The anteromedial aspect of the tibial midshaft has been a common site for the placement of strain gauges; one reason to measure strains in the anterior tibia is that this region is surgically accessible. Aamodt et al. (1997) were able to measure strains on the lateral surface of the proximal femur only because their experimental subjects were

  15. Olive oil and vitamin D synergistically prevent bone loss in mice.

    Directory of Open Access Journals (Sweden)

    Camille Tagliaferri

    Full Text Available As the Mediterranean diet (and particularly olive oil has been associated with bone health, we investigated the impact of extra virgin oil as a source of polyphenols on bone metabolism. In that purpose sham-operated (SH or ovariectomized (OVX mice were subjected to refined or virgin olive oil. Two supplementary OVX groups were given either refined or virgin olive oil fortified with vitamin D3, to assess the possible synergistic effects with another liposoluble nutrient. After 30 days of exposure, bone mineral density and gene expression were evaluated. Consistent with previous data, ovariectomy was associated with increased bone turnover and led to impaired bone mass and micro-architecture. The expression of oxidative stress markers were enhanced as well. Virgin olive oil fortified with vitamin D3 prevented such changes in terms of both bone remodeling and bone mineral density. The expression of inflammation and oxidative stress mRNA was also lower in this group. Overall, our data suggest a protective impact of virgin olive oil as a source of polyphenols in addition to vitamin D3 on bone metabolism through improvement of oxidative stress and inflammation.

  16. Facial nerve paralysis associated with temporal bone masses.

    Science.gov (United States)

    Nishijima, Hironobu; Kondo, Kenji; Kagoya, Ryoji; Iwamura, Hitoshi; Yasuhara, Kazuo; Yamasoba, Tatsuya

    2017-10-01

    To investigate the clinical and electrophysiological features of facial nerve paralysis (FNP) due to benign temporal bone masses (TBMs) and elucidate its differences as compared with Bell's palsy. FNP assessed by the House-Brackmann (HB) grading system and by electroneurography (ENoG) were compared retrospectively. We reviewed 914 patient records and identified 31 patients with FNP due to benign TBMs. Moderate FNP (HB Grades II-IV) was dominant for facial nerve schwannoma (FNS) (n=15), whereas severe FNP (Grades V and VI) was dominant for cholesteatomas (n=8) and hemangiomas (n=3). The average ENoG value was 19.8% for FNS, 15.6% for cholesteatoma, and 0% for hemangioma. Analysis of the correlation between HB grade and ENoG value for FNP due to TBMs and Bell's palsy revealed that given the same ENoG value, the corresponding HB grade was better for FNS, followed by cholesteatoma, and worst in Bell's palsy. Facial nerve damage caused by benign TBMs could depend on the underlying pathology. Facial movement and ENoG values did not correlate when comparing TBMs and Bell's palsy. When the HB grade is found to be unexpectedly better than the ENoG value, TBMs should be included in the differential diagnosis. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. [Effects of Chinese Bushen Zhuanggu medicine on bone loss in female rats after simulated weightlessness].

    Science.gov (United States)

    Sun, Ping; Huang, Zhen; Cai, De-Hong; He, Lei

    2007-02-01

    To study the effect of Bushen Zhuanggu, the traditional Chinese medicine for reinforcing kidney and strengthening bone, on bone loss in female rats after simulated weightlessness. Thirty-six female SD rats were randomly divided into 3 groups, namely normal control group (group A) and two groups of weightlessness simulated by tail suspension (groups B and C). Group C were treated with the Chinese medicine, while groups A and B were given the same dose of normal saline. The experiment lasted 28 days, and all rats were allowed to drink water freely. In the rats of group B, serum bone Gla protein (BGP), alkaline phosphatase (ALP), estradiol (E(2)) and P content and femur bone mineral content (BMD) were significantly lower than those in group A (P<0.01, P<0.05), whereas serum calcium concentration was markedly higher than that in group A (P<0.01). In rats of group C, serum BGP, ALP, E2 and P content and femur BMD were significantly higher than those in group B (P<0.01, P<0.05), but serum calcium concentration was markedly lower (P<0.01). This Chinese prescription can stimulate bone formation and reduce bone loss in female rats subjected to simulated weightlessness.

  18. Evaluation of the efficacy of zoledronic acid and amifostine on radiation induced bone loss in mice

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jin Wook; Lee, Sueum; Kang, Sohi; Moon, Cahng Jong; Kim, Jong Choon; Kim, Sung Ho [College of Veterinary Medicine, Chonnam National University, Gwangju (Korea, Republic of); Jung, Uhee; Jo, Sung Kee [Advanced Radiation Technology Institute, Jeungeup (Korea, Republic of); Jang, Jong Sik [College of Ecology and Environmental Science, Kyungpook National University, Sangju (Korea, Republic of)

    2016-09-15

    This study investigated the effects of zoledronic acid (ZA) on radiation-induced bone loss in C3H/HeN mice. C3H/HeN mice were divided into sham control and three irradiated groups (3 Gy, gamma ray). The irradiated mice were treated for 12 weeks with vehicle, amifostine (intraperitoneal injection), or ZA (subcutaneous injection). Grip strength, uterus weight, and serum alkaline phosphatase (ALP), and tartrate-resistant acid phosphatase (TRAP) levels were measured. Tibiae were analyzed using micro-computed tomography. Treatment of ZA (100 μg·kg{sup -1}·week{sup -1}) significantly preserved trabecular bone volume, trabecular thickness, trabecular number, trabecular separation, bone mineral density of proximal tibia metaphysic, and cortical bone volume, but did not alter the uterus weight of the mice. The administration of ZA for 12 weeks lowered serum ALP and TRAP levels in irradiated mice, suggesting that ZA can reduce the bone turnover rate in mice. No differences were apparent between the amifostine-treated group and the irradiation control group. The results indicate that ZA can prevent radiation-induced bone loss in mice.

  19. Dietary phosphorus exacerbates bone loss induced by cadmium in ovariectomized rats.

    Science.gov (United States)

    Bakhshalian, Neema; Johnson, Sarah A; Hooshmand, Shirin; Feresin, Rafaela G; Elam, Marcus L; Soung, Do Y; Payton, Mark E; Arjmandi, Bahram H

    2014-12-01

    Postmenopausal bone loss can be exacerbated by environmental contaminants, including the heavy metal cadmium (Cd). We hypothesized that incorporating phosphorus (P) into the diet would lead to the chelation of Cd into P, preventing its absorption and subsequent bone loss. To test this hypothesis, we used ovariectomized rats as a model of postmenopausal osteoporosis to examine the deleterious effects of Cd on bone with and without added P. Fifty 3-month-old ovariectomized Sprague-Dawley rats were assigned to five treatment groups (n = 10 per group) for 3 months as follows: (1) control; (2) 50 ppm Cd; (3) 50 ppm Cd plus 1.2% P; (4) 200 ppm Cd; and (5) 200 ppm Cd plus 1.2% P. Cd plus P caused a significant loss of whole body (P = 0.0001 and P properties, 50 ppm Cd plus 1.2% P caused an increase in trabecular separation, whereas 200 ppm Cd plus 1.2% P caused a decrease in bone volume-to-total volume ratio, a decrease in trabecular number, and an increase in trabecular separation and structural model index. Our findings indicate that Cd exposure, along with high intake of P, may be a public health hazard with respect to bone health.

  20. Cannabidiol administration reduces sublesional cancellous bone loss in rats with severe spinal cord injury.

    Science.gov (United States)

    Li, Dehao; Lin, Zilin; Meng, Qingyi; Wang, Kun; Wu, Jiajia; Yan, Hongda

    2017-08-15

    Patients with spinal cord injury (SCI) undergo severe loss of bone mineral below the level of lesion, and data on available treatment options after SCI is scarce. The aim of this work was to investigate the therapeutic effect of cannabidiol (CBD), a non-psychoactive cannabis, on sublesional bone loss in a rat model of SCI. The adult male rats were exposed to surgical transection of the cord and treated with CBD for consecutive 14 days. It was found that CBD treatment elevated the serum levels of osteocalcin, reduced the serum levels of collagen type I cross-linked C-telopeptide, and enhanced bone mineral density of tibiae and femurs. Treatment of SCI rats with CBD enhanced bone volume, trabecular thickness, and trabecular number, and reduced trabecular separation in proximal tibiae, and increased ultimate compressive load, stiffness, and energy to max force of femoral diaphysis. Treatment of SCI rats with CBD upregulated mRNA expression of alkaline phosphatase and osteoprotegerin and downregulated mRNA expression of receptor activator of NF-κB ligand and tartrate-resistant acid phosphatase in femurs. Furthermore, treatment of SCI rats with CBD enhanced mRNA expression of wnt3a, Lrp5 and ctnnb1 in femurs. In conclusion, CBD administration attenuated SCI-induced sublesional cancellous bone loss. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Climbing exercise increases bone mass and trabecular bone turnover through transient regulation of marrow osteogenic and osteoclastogenic potentials in mice.

    Science.gov (United States)

    Mori, Toshiharu; Okimoto, Nobukazu; Sakai, Akinori; Okazaki, Yuichi; Nakura, Nariaki; Notomi, Takuya; Nakamura, Toshitaka

    2003-11-01

    To investigate the relationship between the effects of bone turnover and bone marrow cell development in bone cells, we developed a mouse voluntary climbing exercise model. Climbing exercise increased bone volume and transient osteogenic potential of bone marrow. This model would be suitable for investigating the mechanistic roles of mechanical loading. The relationship between bone mass gain and local bone formation and resorption in mechanically loaded bone is not well understood. Sixty-five C57BL/6J mice, 8 weeks of age, were assigned to five groups: a baseline control and two groups each of ground control and climbing exercise mice for 2 and 4 weeks. Mice were housed in a 100-cm tower and had to climb toward a bottle placed at the top to drink water. Compared with the ground control, bone mineral density of the left femur increased in the climbing mice at 4 weeks. At 2 and 4 weeks, bone formation rate (BFR/BS) of periosteal surface, the cross-sectional area, and moment of inertia were increased in the climbing mice, whereas BFR/BS and eroded surface (ES/BS) of endosteal surface did not differ. The trabecular bone volume (BV/TV) of the proximal tibia increased in climbing mice, and osteoclast surface (Oc.S/BS) and osteoclast number decreased at 2 weeks. At 4 weeks, there were increases in BV/TV and parameters of bone formation, including mineralized surface, mineral apposition rate, and bone formation rate. In marrow cell cultures from the tibia, the number of alkaline phosphatase+ colony forming units-fibroblastic and the area of mineralized nodule formation in climbing mice were increased, and the number of osteoclast-like TRACP+ multinucleated cells was lower at 2 weeks. At 4 weeks, these parameters recovered to the levels of the ground controls. Our results indicate that climbing increased trabecular bone volume and reduced bone resorption, with a subsequent increase in bone formation. Intermittent climbing downregulates marrow osteoclastogenic cells and

  2. Epiphyseal abnormalities, trabecular bone loss and articular chondrocyte hypertrophy develop in the long bones of postnatal Ext1-deficient mice.

    Science.gov (United States)

    Sgariglia, Federica; Candela, Maria Elena; Huegel, Julianne; Jacenko, Olena; Koyama, Eiki; Yamaguchi, Yu; Pacifici, Maurizio; Enomoto-Iwamoto, Motomi

    2013-11-01

    Long bones are integral components of the limb skeleton. Recent studies have indicated that embryonic long bone development is altered by mutations in Ext genes and consequent heparan sulfate (HS) deficiency, possibly due to changes in activity and distribution of HS-binding/growth plate-associated signaling proteins. Here we asked whether Ext function is continuously required after birth to sustain growth plate function and long bone growth and organization. Compound transgenic Ext1(f/f);Col2CreERT mice were injected with tamoxifen at postnatal day 5 (P5) to ablate Ext1 in cartilage and monitored over time. The Ext1-deficient mice exhibited growth retardation already by 2weeks post-injection, as did their long bones. Mutant growth plates displayed a severe disorganization of chondrocyte columnar organization, a shortened hypertrophic zone with low expression of collagen X and MMP-13, and reduced primary spongiosa accompanied, however, by increased numbers of TRAP-positive osteoclasts at the chondro-osseous border. The mutant epiphyses were abnormal as well. Formation of a secondary ossification center was significantly delayed but interestingly, hypertrophic-like chondrocytes emerged within articular cartilage, similar to those often seen in osteoarthritic joints. Indeed, the cells displayed a large size and round shape, expressed collagen X and MMP-13 and were surrounded by an abundant Perlecan-rich pericellular matrix not seen in control articular chondrocytes. In addition, ectopic cartilaginous outgrowths developed on the lateral side of mutant growth plates over time that resembled exostotic characteristic of children with Hereditary Multiple Exostoses, a syndrome caused by Ext mutations and HS deficiency. In sum, the data do show that Ext1 is continuously required for postnatal growth and organization of long bones as well as their adjacent joints. Ext1 deficiency elicits defects that can occur in human skeletal conditions including trabecular bone loss

  3. Combined aerobic and resistance exercise is effective for achieving weight loss and reducing cardiovascular risk factors without deteriorating bone health in obese young adults

    Directory of Open Access Journals (Sweden)

    Jung Sub Lim

    2013-03-01

    Full Text Available PurposeWeight loss reduces cardiovascular risk factors in the obese. However, weight reduction through diet negatively affects long-term bone health. The aim of study was to determine the ability of combined aerobic and resistance exercise (CE to reduce weight and cardiovascular risk without diminishing bone health.MethodsTwenty-five young adults participated in an 8-week weight loss CE program. Subjects were allocated to an obese group or a control group by body mass index (BMI. Body weight, BMI, body composition, and bone mineral density (BMD of the lumbar spine and total hip were measured before and after the CE trial. Serum levels of metabolic markers, including adipokines and bone markers, were also evaluated.ResultsWeight loss was evident in the obese group after the 8 weeks CE trial. Fat mass was significantly reduced in both groups. Fasting insulin, homeostatic model assessment-insulin resistance (HOMA-IR, leptin and aminotransferases level were significantly reduced from baseline only in the obese group. High density lipoprotein cholesterol increased in both groups. Hip BMD increased in the obese group. In all study subjects, BMI changes were correlated with HOMA-IR, leptin, and HDL changes. BMI decreases were correlated with lumbar spine BMD increases, lumbar spine BMD increases were positively correlated with osteocalcin changes, and lumbar spine bone mineral content increases were correlated negatively with C-terminal telopeptide of type 1 collagen changes.ConclusionThese findings suggest that CE provides effective weight loss and improves cardiovascular risk factors without diminishing BMD. Furthermore, they indicate that lumbar spine BMD might be maintained by increasing bone formation and decreasing bone resorption.

  4. Maternal first-trimester diet and childhood bone mass: the Generation R Study.

    Science.gov (United States)

    Heppe, Denise H M; Medina-Gomez, Carolina; Hofman, Albert; Franco, Oscar H; Rivadeneira, Fernando; Jaddoe, Vincent W V

    2013-07-01

    Maternal diet during pregnancy has been suggested to influence bone health in later life. We assessed the association of maternal first-trimester dietary intake during pregnancy with childhood bone mass. In a prospective cohort study in 2819 mothers and their children, we measured first-trimester daily energy, protein, fat, carbohydrate, calcium, phosphorus, and magnesium intakes by using a food-frequency questionnaire and homocysteine, folate, and vitamin B-12 concentrations in venous blood. We measured childhood total body bone mass by using dual-energy X-ray absorptiometry at the median age of 6.0 y. Higher first-trimester maternal protein, calcium, and phosphorus intakes and vitamin B-12 concentrations were associated with higher childhood bone mass, whereas carbohydrate intake and homocysteine concentrations were associated with lower childhood bone mass (all P-trend childhood bone mass. In the fully adjusted regression model that included all dietary factors significantly associated with childhood bone mass, maternal phosphorus intake and homocysteine concentrations most-strongly predicted childhood bone mineral content (BMC) [β = 2.8 (95% CI: 1.1, 4.5) and β = -1.8 (95% CI: -3.6, 0.1) g per SD increase, respectively], whereas maternal protein intake and vitamin B-12 concentrations most strongly predicted BMC adjusted for bone area [β = 2.1 (95% CI: 0.7, 3.5) and β = 1.8 (95% CI: 0.4, 3.2) g per SD increase, respectively]. Maternal first-trimester dietary factors are associated with childhood bone mass, suggesting that fetal nutritional exposures may permanently influence bone development.

  5. Missense Mutations in LRP5 Associated with High Bone Mass Protect the Mouse Skeleton from Disuse- and Ovariectomy-Induced Osteopenia.

    Directory of Open Access Journals (Sweden)

    Paul J Niziolek

    Full Text Available The low density lipoprotein receptor-related protein-5 (LRP5, a co-receptor in the Wnt signaling pathway, modulates bone mass in humans and in mice. Lrp5 knock-out mice have severely impaired responsiveness to mechanical stimulation whereas Lrp5 gain-of-function knock-in and transgenic mice have enhanced responsiveness to mechanical stimulation. Those observations highlight the importance of Lrp5 protein in bone cell mechanotransduction. It is unclear if and how high bone mass-causing (HBM point mutations in Lrp5 alter the bone-wasting effects of mechanical disuse. To address this issue we explored the skeletal effects of mechanical disuse using two models, tail suspension and Botulinum toxin-induced muscle paralysis, in two different Lrp5 HBM knock-in mouse models. A separate experiment employing estrogen withdrawal-induced bone loss by ovariectomy was also conducted as a control. Both disuse stimuli induced significant bone loss in WT mice, but Lrp5 A214V and G171V were partially or fully protected from the bone loss that normally results from disuse. Trabecular bone parameters among HBM mice were significantly affected by disuse in both models, but these data are consistent with DEXA data showing a failure to continue growing in HBM mice, rather than a loss of pre-existing bone. Ovariectomy in Lrp5 HBM mice resulted in similar protection from catabolism as was observed for the disuse experiments. In conclusion, the Lrp5 HBM alleles offer significant protection from the resorptive effects of disuse and from estrogen withdrawal, and consequently, present a potential mechanism to mimic with pharmaceutical intervention to protect against various bone-wasting stimuli.

  6. Phyto-oestrogen excretion and rate of bone loss in postmenopausal women

    NARCIS (Netherlands)

    Kardinaal, A.F.M.; Morton, M.S.; Brüggemann-Rotgans, I.E.M.; Beresteijn, E.C.H. van

    1998-01-01

    Objective: The hypothesis was tested that the rate of postmenopausal bone loss is inversely associated with long-term urinary excretion of phyto-oestrogens, as a marker of habitual dietary intake. Design: Secondary analysis of a 10-year follow-up study (1979-1989) among postmenopausal women in the

  7. Stemmed femoral knee prostheses: effects of prosthetic design and fixation on bone loss.

    NARCIS (Netherlands)

    Lenthe, G.H. van; Willems, P.C.P.H.; Verdonschot, N.J.J.; Waal Malefijt, M.C. de; Huiskes, R.

    2002-01-01

    Although the revision rates for modern knee prostheses have decreased drastically, the total number of revisions a year is increasing because many more primary knee replacements are being done. At the time of revision, bone loss is common, which compromises prosthetic stability. To improve

  8. Suppression of NADPH oxidases prevents chronic ethanol-induced bone loss

    Science.gov (United States)

    Since the molecular mechanisms through which chronic excessive alcohol consumption induces osteopenia and osteoporosis are largely unknown, potential treatments for prevention of alcohol-induced bone loss remain unclear. We have previously demonstrated that, chronic ethanol (EtOH) treatment leads to...

  9. Java project on periodontal diseases: periodontal bone loss in relation to environmental and systemic conditions

    NARCIS (Netherlands)

    Amaliya, A.; Laine, M.L.; Delanghe, J.R.; Loos, B.G.; van Wijk, A.J.; van der Velden, U.

    2015-01-01

    Objective To assess in a population deprived from regular dental care the relationship between alveolar bone loss (ABL) and environmental/systemic conditions. Material & Methods The study population consisted of subjects from the Purbasari tea estate on West Java, Indonesia. A full set of dental

  10. Validation of a dental image analyzer tool to measure alveolar bone loss in periodontitis patients

    NARCIS (Netherlands)

    Teeuw, W.J.; Coelho, L.; de Silva, A.; van der Palen, C.J.N.M.; Lessmann, F.G.J.M.; van der Velden, U.; Loos, B.G.

    2009-01-01

    Background and Objective:  Radiographs are an essential adjunct to the clinical examination for periodontal diagnoses. Over the past few years, digital radiographs have become available for use in clinical practice. Therefore, the present study investigated whether measuring alveolar bone loss,

  11. Mandibular fracture caused by peri-implant bone loss : Report of a case

    NARCIS (Netherlands)

    Meijer, Henny J. A.; Raghoebar, Gerry M.; Visser, Anita

    Background: A major complication related to excessive bone loss around implants is fracture of the mandible. This complication is most likely to occur in a very atrophic mandible. A 57-year-old woman presented with progressive pain and swelling that had been present for 5 days in the right frontal

  12. Hindfoot arthrodesis for management of bone loss following calcaneus fractures and nonunions.

    Science.gov (United States)

    Molloy, Andy P; Lipscombe, Stephen J

    2011-03-01

    Massive bone loss following calcaneal fractures is a challenging condition to treat, especially if nonunion is present. Meticulous preoperative examination and imaging are crucial for accurate preoperative planning. If performed, successful outcomes can be achieved with the strategies outlined in this article. Copyright © 2011 Elsevier Inc. All rights reserved.

  13. Dental Implant Thread Design and the Consequences on Long-Term Marginal Bone Loss.

    Science.gov (United States)

    Ormianer, Zeev; Matalon, Shlomo; Block, Jonathan; Kohen, Jerry

    2016-08-01

    The aim of this study was to present the implant macrostructure effect on marginal bone loss using 3 dental implant thread designs with differences in thread pitch, lead, and helix angle. All implants used were sourced from the same company and had the same microstructured surface. This is a nonrandomized, retrospective, double-blind study. Data were collected by an independent Tel Aviv University group from a general practitioner's private practice patient records. In total, 1361 implants met the inclusion criteria representing the 3 types of implants macrostructure. Overall survival rate was 96.3% with 50 implants failing (3.7%) out of a total of 1361 implants. Survival rates for the 3 groups were: group A 96.6%, group B 95.9%, and in group C 100%. Average bone loss for groups A, B, and C were 2.02 (±1.70) mm, 2.10 (±1.73) mm, and 1.90 (±1.40) mm, respectively. Pairwise comparisons revealed that less bone loss occurred in group A compared with group B (P = 0.036). Favorable long-term bone loss results were found in implants with a larger pitch, deeper apical threads, and a narrower implant core. One-piece V-thread design implants demonstrated 100% survival rate.

  14. Alendronate and estrogen-progestin in the long-term prevention of bone loss

    DEFF Research Database (Denmark)

    Ravn, Pernille; Bidstrup, M; Wasnich, R D

    1999-01-01

    BACKGROUND: Up to 3 years of treatment with alendronate, 5 mg/d, prevents postmenopausal bone loss. OBJECTIVE: To determine whether the effect of alendronate is sustained at 4 years of treatment and persists after treatment is discontinued. DESIGN: Randomized, controlled trial. SETTING: United St...

  15. Effect of dietary soy isoflavones on bone loss in ovariectomized rats

    African Journals Online (AJOL)

    Tropical Journal of Pharmaceutical Research January 2018; 17 (1): 91-96 .... B. M. D. (g/cm. 2. ) group. **. *. Figure 3: Soy isoflavone supplementation suppresses the reduction of BMD (g/cm2) in OVX rats. 1, intact rats; 2, untreated OVX rats; 3–5, OVX rats treated .... Estrogen deficiency associated bone loss in the maxilla: ...

  16. No major effect of estrogen receptor gene polymorphisms on bone mineral density or bone loss in postmenopausal Danish women

    DEFF Research Database (Denmark)

    Bagger, Y Z; Jørgensen, H L; Heegaard, Anne-Marie

    2000-01-01

    The polymorphisms of the estrogen receptor (ER) gene defined by the restriction enodonucleases PvuII and XbaI have recently been reported to be associated with bone mineral density (BMD) in postmenopausal women. To investigate the possible relation of the PvuII and XbaI restriction fragment......-length polymorphisms of the ER gene with BMD in Danish postmenopausal women, two studies were undertaken: 1) a cross-sectional study of 499 postmenopausal women, where the ER genotypes and alleles were related to BMD of the hip, spine, and lower forearm; and 2) a longitudinal study of 101 postmenopausal women followed...... up for 18 years. In the latter study, late postmenopausal bone loss in the hip and spine was determined over a period of 6 years in women (mean age of 63 to 69 years), and long-term postmenopausal bone loss in the lower forearm was determined over a period of 18 years in women (mean age of 51 to 69...

  17. Donepezil prevents RANK-induced bone loss via inhibition of osteoclast differentiation by downregulating acetylcholinesterase.

    Science.gov (United States)

    Sato, Tsuyoshi; Enoki, Yuichiro; Sakamoto, Yasushi; Yokota, Kazuhiro; Okubo, Masahiko; Matsumoto, Masahito; Hayashi, Naoki; Usui, Michihiko; Kokabu, Shoichiro; Mimura, Toshihide; Nakazato, Yoshihiko; Araki, Nobuo; Fukuda, Toru; Okazaki, Yasushi; Suda, Tatsuo; Takeda, Shu; Yoda, Tetsuya

    2015-09-01

    Donepezil, an inhibitor of acetylcholinesterase (AChE) targeting the brain, is a common medication for Alzheimer's disease. Interestingly, a recent clinical study found that administration of this agent is associated with lower risk of hip fracture independently of falling, suggesting its direct effect on bone tissues as well. AChE has been reported to be involved in osteoblast function, but the role of AChE on osteoclastogenesis still remains unclear. We analyzed the effect of AChE and donepezil on osteoclastogenesis in vivo and in vitro. Cell-based assays were conducted using osteoclasts generated in cultures of murine bone marrow macrophages (BMMs) with receptor activator of nuclear factor-kappa B ligand (RANKL). The effect of donepezil was also determined in vivo using a mouse model of RANKL-induced bone loss. Recombinant AChE in BMMs cultured with RANKL further promoted RANKL-induced tartrate-resistant acid phosphatase (TRAP)-positive osteoclast differentiation. RANKL also upregulated AChE expression in BMMs. RNA interference-mediated knockdown of AChE significantly inhibited RANKL-induced osteoclast differentiation and suppressed gene expression specific for osteoclasts. AChE upregulated expression of RANK, the receptor of RANKL, in BMMs. Donepezil decreased cathepsin K expression in BMMs and the resorptive function of osteoclasts on dentine slices. Donepezil decreased RANK expression in BMMs, resulting in the inhibition of osteoclast differentiation with downregulation of c-Fos and upregulation of Id2. Moreover, administration of donepezil prevented RANKL-induced bone loss in vivo, which was associated with the inhibition of bone resorption by osteoclasts. AChE promotes osteoclast differentiation in vitro. Donepezil inhibits osteoclast function in vitro and prevents bone loss by suppressing bone resorption in vivo, suggesting the possibility that donepezil reduces fracture risk in patients with Alzheimer's disease.

  18. Matrine prevents bone loss in ovariectomized mice by inhibiting RANKL-induced osteoclastogenesis

    Science.gov (United States)

    Chen, Xiao; Zhi, Xin; Pan, Panpan; Cui, Jin; Cao, Liehu; Weng, Weizong; Zhou, Qirong; Wang, Lin; Zhai, Xiao; Zhao, Qingiie; Hu, Honggang; Huang, Biaotong; Su, Jiacan

    2017-01-01

    Osteoporosis is a metabolic bone disease characterized by decreased bone density and strength due to excessive loss of bone protein and mineral content. The imbalance between osteogenesis by osteoblasts and osteoclastogenesis by osteoclasts contributes to the pathogenesis of postmenopausal osteoporosis. Estrogen withdrawal leads to increased levels of proinflammatory cytokines. Overactivated osteoclasts by inflammation play a vital role in the imbalance. Matrine is an alkaloid found in plants from the Sophora genus with various pharmacological effects, including anti-inflammatory activity. Here we demonstrate that matrine significantly prevented ovariectomy-induced bone loss and inhibited osteoclastogenesis in vivo with decreased serum levels of TRAcp5b, TNF-α, and IL-6. In vitro matrine significantly inhibited osteoclast differentiation induced by receptor activator for NF-κB ligand (RANKL) and M-CSF in bone marrow monocytes and RAW264.7 cells as demonstrated by tartrate-resistant acid phosphatase (TRAP) staining and actin-ring formation as well as bone resorption through pit formation assays. For molecular mechanisms, matrine abrogated RANKL-induced activation of NF-κB, AKT, and MAPK pathways and suppressed osteoclastogenesis-related marker expression, including matrix metalloproteinase 9, NFATc1, TRAP, C-Src, and cathepsin K. Our study demonstrates that matrine inhibits osteoclastogenesis through modulation of multiple pathways and that matrine is a promising agent in the treatment of osteoclast-related diseases such as osteoporosis.—Chen, X., Zhi, X., Pan, P., Cui, J., Cao, L., Weng, W., Zhou, Q., Wang, L., Zhai, X. Zhao, Q., Hu, H., Huang, B., Su, J. Matrine prevents bone loss in ovariectomized mice by inhibiting RANKL-induced osteoclastogenesis. PMID:28739641

  19. Peak bone mass from longitudinal data: implications for the prevalence, pathophysiology, and diagnosis of osteoporosis.

    Science.gov (United States)

    Berger, Claudie; Goltzman, David; Langsetmo, Lisa; Joseph, Lawrence; Jackson, Stuart; Kreiger, Nancy; Tenenhouse, Alan; Davison, K Shawn; Josse, Robert G; Prior, Jerilynn C; Hanley, David A

    2010-09-01

    We estimated peak bone mass (PBM) in 615 women and 527 men aged 16 to 40 years using longitudinal data from the Canadian Multicentre Osteoporosis Study (CaMos). Individual rates of change were averaged to find the mean rate of change for each baseline age. The age range for PBM was defined as the period during which bone mineral density (BMD) was stable. PBM was estimated via hierarchical models, weighted according to 2006 Canadian Census data. Lumbar spine PBM (1.046 ± 0.123 g/cm(2)) occurred at ages 33 to 40 years in women and at 19 to 33 years in men (1.066 ± 0.129 g/cm(2)). Total hip PBM (0.981 ± 0.122 g/cm(2)) occurred at ages 16 to 19 years in women and 19 to 21 years in men (1.093 ± 0.169 g/cm(2)). Analysis of Canadian geographic variation revealed that the levels of PBM and of mean BMD in those over age 65 sometimes were discordant, suggesting that PBM and subsequent rates of bone loss may be subject to different genetic and/or environmental influences. Based on our longitudinally estimated PBM values, the estimated Canadian prevalences of osteoporosis (T-score < -2.5) were 12.0% (L(1)-L(4)) and 9.1% (total hip) in women aged 50 years and older and 2.9% (L(1)-L(4)) and 0.9% (total hip) in men aged 50 years and older. These were higher than prevalences using cross-sectional PBM data. In summary, we found that the age at which PBM is achieved varies by sex and skeletal site, and different reference values for PBM lead to different estimates of the prevalence of osteoporosis. Furthermore, lack of concordance of PBM and BMD over age 65 suggests different determinants of PBM and subsequent bone loss. © 2010 American Society for Bone and Mineral Research.

  20. Smoking is associated with impaired bone mass development in young adult men: a 5-year longitudinal study.

    Science.gov (United States)

    Rudäng, Robert; Darelid, Anna; Nilsson, Martin; Nilsson, Staffan; Mellström, Dan; Ohlsson, Claes; Lorentzon, Mattias

    2012-10-01

    It has previously been shown that smoking is associated with reduced bone mass and increased fracture risk, but no longitudinal studies have been published investigating altered smoking behavior at the time of bone mass acquisition. The aim of this study was to investigate the development of bone density and geometry according to alterations in smoking behavior in a 5-year, longitudinal, population-based study of 833 young men, age 18 to 20 years (baseline). Furthermore, we aimed to examine the cross-sectional, associations between current smoking and parameters of trabecular microarchitecture of the radius and tibia, using high-resolution peripheral quantitative computed tomography (HR-pQCT), in young men aged 23 to 25 years (5-year follow-up). Men who had started to smoke since baseline had considerably smaller increases in areal bone mineral density (aBMD) at the total body (mean ± SD, 0.020 ± 0.047 mg/cm(2) versus 0.043 ± 0.040 mg/cm(2) , p young adulthood have poorer development of their aBMD at clinically important sites such as the spine and hip than nonsmokers, possibly due to augmented loss of trabecular density and impaired growth of cortical cross-sectional area. Copyright © 2012 American Society for Bone and Mineral Research.

  1. Site-specific variability in trabecular bone dosimetry: Considerations of energy loss to cortical bone

    International Nuclear Information System (INIS)

    Patton, P.W.; Rajon, D.A.; Shah, A.P.; Jokisch, D.W.; Inglis, B.A.; Bolch, W.E.

    2002-01-01

    With continual advances in radionuclide therapies, increasing emphasis is being placed on improving the patient specificity of dose estimates to marrow tissues. While much work has been focused on determining patient-specific assessments of radionuclide uptake in the skeleton, few studies have been initiated to explore the individual variability of absorbed fraction data for electron and beta-particle sources in various skeletal sites. The most recent values of radionuclide S values used in clinical medicine continue to utilize a formalism in which electrons are transported under a trabecular bone geometry of infinite extent. No provisions are thus made for the fraction of energy lost to the cortical bone cortex of the skeletal site and its surrounding tissues. In the present study, NMR microscopy was performed on trabecular bone samples taken from the femoral head and humeral proximal epiphysis of three subjects: a 51-year male, an 82-year female, and an 86-year female. Following image segmentation and coupling to EGS4, electrons were transported within macrostructural models of the various skeletal sites that explicitly include the spatial extent of the spongiosa, as well as the thickness of the surrounding cortical bone. These energy-dependent profiles of absorbed fractions to marrow tissues were then compared to transport simulations made within an infinite region of spongiosa. Ratios of mean absorbed fraction, as weighted by the beta energy spectra, under both transport methodologies were then assembled for the radionuclides 32 P and 90 Y. These ratios indicate that corrections to existing radionuclide S values for 32 P can vary by as much as 5% for the male, 6% for the 82-year female, and 8% for the 86-year female. For the higher-energy beta spectrum of 90 Y, these same corrections can reach 8%, 10%, and 11%, respectively

  2. High-impact exercise in rats prior to and during suspension can prevent bone loss.

    Science.gov (United States)

    Yanagihara, G R; Paiva, A G; Gasparini, G A; Macedo, A P; Frighetto, P D; Volpon, J B; Shimano, A C

    2016-03-01

    High-impact exercise has been considered an important method for treating bone loss in osteopenic experimental models. In this study, we investigated the effects of osteopenia caused by inactivity in femora and tibiae of rats subjected to jump training using the rat tail suspension model. Eight-week-old female Wistar rats were divided into five groups (n=10 each group): jump training for 2 weeks before suspension and training during 3 weeks of suspension; jump training for 2 weeks before suspension; jump training only during suspension; suspension without any training; and a control group. The exercise protocol consisted of 20 jumps/day, 5 days/week, with a jump height of 40 cm. The bone mineral density of the femora and tibiae was measured by double energy X-ray absorptiometry and the same bones were evaluated by mechanical tests. Bone microarchitecture was evaluated by scanning electron microscopy. One-way ANOVA was used to compare groups. Significance was determined as Pbone mineral density, mechanical properties and bone microarchitecture, the beneficial effects were greater in the bones of animals subjected to pre-suspension training and subsequently to training during suspension, compared with the bones of animals subjected to pre-suspension training or to training during suspension. Our results indicate that a period of high impact exercise prior to tail suspension in rats can prevent the installation of osteopenia if there is also training during the tail suspension.

  3. Three-dimensional measurement of bone loss at implants in patients with periodontal disease.

    Science.gov (United States)

    Kehl, Marcus; Swierkot, Katrin; Mengel, Reiner

    2011-05-01

    The aim of this prospective study is to evaluate the three-dimensional marginal bone level around implants 5 to 15 years after loading in partially edentulous patients treated for generalized chronic periodontitis (GCP) and generalized aggressive periodontitis (GAgP). Seventeen patients with GCP and 17 patients with GAgP were treated with a total of 119 implants. Patients were examined clinically on a 3-month recall schedule after insertion of the superstructure, and radiographs were taken at fixed intervals. At the end of the observation period, cone-beam computed tomography was used for the analysis of the circumferential three-dimensional bone level (mesial, distal, buccal, and lingual/palatal) and determination of keratinized mucosa thickness (KMT). In both groups, a significant bone loss at implants was observed buccally (GAgP group: 4.49 ± 2.93 mm; GCP group: 3.57 ± 2.94 mm) with significantly more average bone loss in patients with GAgP (3.00 ± 1.67 mm) compared to in patients with GCP (2.45 ± 1.08 mm). The lowest values for KMT in both groups were found in the anterior mandible (GAgP group: 0.99 ± 1.13 mm; GCP group: 0.82 ± 0.91 mm). There were significant correlations between clinical parameters and bone loss in mandibles of patients with GAgP. The lowest value for KMT in both groups was found in the mandible. Bone loss was observed buccally and was more pronounced in patients with GAgP, with a significant correlation with keratinized mucosa and increased inflammation.

  4. The recent prevalence of Osteoporosis and low bone mass in the United States based on bone mineral density at the Femoral Neck or Lumbar Spine

    Science.gov (United States)

    The goal of our study was to estimate the prevalence of osteoporosis and low bone mass based on bone mineral density (BMD) at the femoral neck and the lumbar spine in adults 50 years and older in the United States (US). We applied prevalence estimates of osteoporosis or low bone mass at the femoral ...

  5. Dietary flavonoid kaempferol inhibits glucocorticoid-induced bone loss by promoting osteoblast survival.

    Science.gov (United States)

    Adhikary, Sulekha; Choudhary, Dharmendra; Ahmad, Naseer; Karvande, Anirudha; Kumar, Avinash; Banala, Venkatesh Teja; Mishra, Prabhat Ranjan; Trivedi, Ritu

    2018-02-13

    Kaempferol, a dietary flavonoid found in fruits and vegetables, has been reported to reverse osteopenic condition in ovariectomized rats. Because kaempferol is endowed with osteogenic activity, the aim of this study was to determine whether it has a beneficial effect on glucocorticoid (GC)-induced bone loss. Adult female rats were divided into four groups as control (vehicle; distilled water), methylprednisolone (MP; 5 mg•kg•d, subcutaneously), MP + kaempferol (5 mg•kg•d, oral), and MP + human parathyroid 1-34 (30 µg/kg, 5 times/wk, subcutaneously) and treated for 4 wk. To study the antagonizing effect of kaempferol on GC-induced inhibition of fracture healing, drill-hole injury was performed on control and GC-treated rats. An oral dose of kaempferol was given for 14 d to observe the effect on callus formation at the site of injury. After treatment, bones were collected for further analysis. GC was associated with a decreased bone mineral density and impaired bone microarchitecture parameters. Consumption of kaempferol induced bone-sparing effects in GC-induced osteopenic condition. Additionally, improved callus formation at site of drill injury in femur diaphysis was observed with kaempferol consumption in animals on GC. Consistent with the in vivo data, kaempferol elicited a higher expression of osteogenic markers in vitro and antagonized the apoptotic effect of dexamethasone on calvarial osteoblasts. These results suggested that kaempferol reduced GC-induced bone loss and enhanced bone regeneration at fractured site, thus emphasizing the positive role of flavonoids on bone health. Copyright © 2018 Elsevier Inc. All rights reserved.

  6. Transient Mass Loss in Active Stars and Observation Methods

    Science.gov (United States)

    Crosley, Michael; Osten, Rachel A.

    2017-05-01

    One factor important to habitability is the impact of stellar eruptive events on nearby exoplanets.This is currently poorly constrained due to heavy reliance on solar scaling relationships and a lack of experimental evidence. The potential impact of space weather and atmospheric stripping due to the impacts of coronal mass ejections, a large eruption of magnetic field and plasma, are not yet understood. Low frequency dynamic spectra of radio bursts from nearby stars offer the best chance to directly detect and characterize the stellar signature of transient mass loss on low mass stars. By using solar solar observations, analogous to those found in stellar studies, we test the validity and accuracy of the results obtained by the multi-wavelength methodology proposed in Crosley et. al 2016. We find that, when a pre-event temperature can be determined, that the accuracy of CME speeds are within a few hundred km/s, and are reliable when specific criteria has been met while CME mass and kinetic energies are only useful in determining approximate order of magnitude. We take these results and apply them to 15 hr of observation of YZ Canis Minoris (YZ CMi), a nearby M dwarf flare star, taken in LOFAR's beam-formed observation mode. The observations utilized the Low Band Antenna (10-90 MHz) or High Band Antenna (110-190 MHz) for five three-hour observation periods. There were no confirmed type II events in this frequency range. We explore the range of parameter space for type II bursts constrained by our observations. Assuming the rate of shocks is a lower limit to the rate at which CMEs occur, no detections in a total of 15 hr of observation places a limit of ν_type II < 0.0667 type II shocks / hr < ν_CME for YZ CMi due to the stochastic nature of the events and the limits of observational sensitivity. Preliminary results on 60 hours of JVLA observations on EQ Peg are also reported on.

  7. Comparative Evaluation of the Prevalence of Maxillary Sinus Mucosal Thickening in the Patients with Periodontal Bone Loss: A Digital Panoramic Study

    Directory of Open Access Journals (Sweden)

    S Mirbeigi

    2015-07-01

    Results: Mucosal thickening was significantly correlated with the bone loss and pattern type of the bone loss. Moreover, the prevalence of sinus mucosal thickening was 12.10% in patients with mild bone loss, 27.45% in patients with moderate bone loss, 63.15% in patients with severe bone loss. No statistically significant relationship was detected between Maxillary sinus mucositis with patients’ age and sex (p =0.05. Conclusion: In patients suffering from the bone loss, increased severity of the bone loss can lead to an increase in the prevalence of sinus mucosal thickening. The maxillary sinus mucositis was reported to be more prevalent in the bone loss with a vertical pattern rather than the bone loss with a horizontal pattern. Moreover, based on the results of the present study, the periodontal disease may increase the risk of sinus mucosal thickening.

  8. Genetic predisposition to low bone mass is paralleled by an enhanced sensitivity to signals anabolic to the skeleton

    Science.gov (United States)

    Judex, Stefan; Donahue, Leah-Rae; Rubin, Clinton

    2002-01-01

    The structure of the adult skeleton is determined, in large part, by its genome. Whether genetic variations may influence the effectiveness of interventions to combat skeletal diseases remains unknown. The differential response of trabecular bone to an anabolic (low-level mechanical vibration) and a catabolic (disuse) mechanical stimulus were evaluated in three strains of adult mice. In low bone-mineral-density C57BL/6J mice, the low-level mechanical signal caused significantly larger bone formation rates (BFR) in the proximal tibia, but the removal of functional weight bearing did not significantly alter BFR. In mid-density BALB/cByJ mice, mechanical stimulation also increased BFR, whereas disuse significantly decreased BFR. In contrast, neither anabolic nor catabolic mechanical signals influenced any index of bone formation in high-density C3H/HeJ mice. Together, data from this study indicate that the sensitivity of trabecular tissue to both anabolic and catabolic stimuli is influenced by the genome. Extrapolated to humans, these results may explain in part why prophylaxes for low bone mass are not universally effective, yet also indicate that there may be a genotypic indication of people who are at reduced risk of suffering from bone loss.

  9. Children with chronic kidney disease: a 3-year prospective study of growth, bone mass and bone turnover.

    Science.gov (United States)

    Swolin-Eide, Diana; Hansson, Sverker; Magnusson, Per

    2009-02-01

    Children with chronic kidney disease (CKD) are at risk of developing skeletal problems. This 3-year prospective study investigated the development of bone mass and bone turnover in children with CKD. Fifteen patients, 4-15 years, were included with a median glomerular filtration rate of 48 (range 8-94) mL/min/1.73 m(2). Bone mineral density (BMD) and markers of bone and mineral metabolism were investigated over a 3-year period. Growth was satisfactory but a delayed bone age was observed. Total body bone mineral density (TBBMD) Z-scores were below zero in five patients at start and after 3 years, but none had a Z-score below -2.5. Lumbar spine BMD Z-scores were below zero in three patients at start and in five patients after 3 years. The median TBBMD and lumbar spine Z-scores did not change during the study period. Eleven CKD patients had increased PTH levels at baseline and 13 patients after 3 years. Most children had normal levels of leptin and vitamin D. Almost 50% of the patients had increased osteoprotegerin levels after 3 years. A normal BMD does not exclude mineral bone disorder in patients with CKD, yet the BMD Z-scores were well preserved and most markers of bone turnover were within the reference intervals.

  10. Cell fusion in osteoclasts plays a critical role in controlling bone mass and osteoblastic activity

    International Nuclear Information System (INIS)

    Iwasaki, Ryotaro; Ninomiya, Ken; Miyamoto, Kana; Suzuki, Toru; Sato, Yuiko

    2008-01-01

    The balance between osteoclast and osteoblast activity is central for maintaining the integrity of bone homeostasis. Here we show that mice lacking dendritic cell specific transmembrane protein (DC-STAMP), an essential molecule for osteoclast cell-cell fusion, exhibited impaired bone resorption and upregulation of bone formation by osteoblasts, which do not express DC-STAMP, which led to increased bone mass. On the contrary, DC-STAMP over-expressing transgenic (DC-STAMP-Tg) mice under the control of an actin promoter showed significantly accelerated cell-cell fusion of osteoclasts and bone resorption, with decreased osteoblastic activity and bone mass. Bone resorption and formation are known to be regulated in a coupled manner, whereas DC-STAMP regulates bone homeostasis in an un-coupled manner. Thus our results indicate that inhibition of a single molecule provides both decreased osteoclast activity and increased bone formation by osteoblasts, thereby increasing bone mass in an un-coupled and a tissue specific manner.

  11. Correlation analysis of alveolar bone loss in buccal/palatal and proximal surfaces in rats

    Directory of Open Access Journals (Sweden)

    Carolina Barrera de Azambuja

    2012-12-01

    Full Text Available The aim was to correlate alveolar bone loss in the buccal/palatal and the mesial/distal surfaces of upper molars in rats. Thirty-three, 60-day-old, male Wistar rats were divided in two groups, one treated with alcohol and the other not treated with alcohol. All rats received silk ligatures on the right upper second molars for 4 weeks. The rats were then euthanized and their maxillae were split and defleshed with sodium hypochlorite (9%. The cemento-enamel junction (CEJ was stained with 1% methylene blue and the alveolar bone loss in the buccal/palatal surfaces was measured linearly in 5 points on standardized digital photographs. Measurement of the proximal sites was performed by sectioning the hemimaxillae, restaining the CEJ and measuring the alveolar bone loss linearly in 3 points. A calibrated and blinded examiner performed all the measurements. Intraclass Correlation Coefficient revealed values of 0.96 and 0.89 for buccal/lingual and proximal surfaces, respectively. The Pearson Correlation Coefficient (r between measurements in buccal/palatal and proximal surfaces was 0.35 and 0.05 for the group treated with alcohol, with and without ligatures, respectively. The best correlations between buccal/palatal and proximal surfaces were observed in animals not treated with alcohol, in sites both with and without ligatures (r = 0.59 and 0.65, respectively. A positive correlation was found between alveolar bone loss in buccal/palatal and proximal surfaces. The correlation is stronger in animals that were not treated with alcohol, in sites without ligatures. Areas with and without ligature-induced periodontal destruction allow detection of alveolar bone loss in buccal/palatal and proximal surfaces.

  12. Forearm bone mineral density changes during postpartum and the effects of breastfeeding, amenorrhea, body mass index and contraceptive use.

    Science.gov (United States)

    Costa, M L; Krupa, F G; Rehder, P M; Sousa, M H; Costa-Paiva, L; Cecatti, J G

    2012-06-01

    Prospective cohort study performed to evaluate bone mineral density (BMD) changes up to 12 months postpartum of healthy women and its association with breastfeeding, contraceptive methods, amenorrhea, and body mass index (BMI). There is a trend in bone loss during the first 6 months with posterior recovery, with evidence of a protective effect of hormonal contraception. This study was conducted to evaluate bone mineral density (BMD) changes during postpartum period among healthy women and its association with breastfeeding, use of contraceptive methods, amenorrhea and body mass index (BMI). A prospective cohort study including 100 healthy women. Distal BMD was measured 7-10 days, 3, 6, and 12 months postpartum at the nondominant forearm using dual-energy X-ray absorptiometry. Data about breastfeeding duration, amenorrhea, contraceptive use and BMI were collected. Seventy-eight women had a complete set of BMD measurements. The mean duration of exclusive breastfeeding was 125.9 (±66.6) days, with a median total lactation period of 263.5 days. The mean duration of amenorrhea was 164.2 (±119.2) days. BMD measurements showed a significant decrease in the distal radius, however with no significance in the ultradistal radius. When considering only the nonhormonal contraceptive users, the difference at 12 months was significant. Multivariate analysis of variance showed that both BMI and contraceptive use were significantly correlated with BMD. Multiple linear regression analysis showed significant correlation of distal radius with baseline BMD at the same site, pregestational BMI, age, years of schooling and difference in BMI. For ultradistal radius, there was a significant direct correlation with its baseline BMD and pregestational BMI. There was a trend in bone loss during the first 6 months postpartum with posterior recovery. Also, hormonal contraceptive methods provided protection of bone loss. However, the long duration of breastfeeding and the follow-up were not

  13. Mass loss as a driving mechanism of tectonics of Enceladus

    Science.gov (United States)

    Czechowski, Leszek

    2015-04-01

    Summary We suggest that the mass loss from South Polar Terrain (SPT) is the main driving force of the following tectonic processes on Enceladus: subsidence of SPT, flow in the mantle and motion of plates. 1. Introduction Enceladus, a satellite of Saturn, is the smallest celestial body in the Solar System where volcanic activity is observed. Every second, the mass of ~200 kg is ejected into space from the South Polar Terrain (SPT) - [1, 2, 3]. The loss of matter from the body's interior should lead to global compression of the crust. Typical effects of compression are: thrust faults, folding and subduction. However, such forms are not dominant on Enceladus. We propose here special tectonic model that could explain this paradox. 2. Subsidence of SPT and tectonics The volatiles escape from the hot region through the fractures forming plumes in the space. The loss of the volatiles results in a void, an instability, and motion of solid matter into the hot region to fill the void. The motion includes : Subsidence of the 'lithosphere' of SPT. Flow of the matter in the mantle. Motion of plates adjacent to SPT towards the active region. If emerging void is being filled by the subsidence of SPT only, then the velocity of subsidence is ~0.05 mm-yr-1. However, all three types of motion are probably important, so the subsidence is slower but mantle flow and plates' motion also play a role in filling the void. Note that in our model the reduction of the crust area is not a result of compression but it is a result of the plate sinking. Therefore the compressional surface features do not have to be dominant. 3. Models of subsidence The numerical model of suggested process of subsidence is developed. It is based on the typical set of equation: Navier-Stokes equation for incompressible viscous liquid, equation of continuity and equation of heat conduction. The Newtonian and non-Newtonian rheologies are used. The preliminary results of the model indicate that the subsidence rate of

  14. Uncoupling protein-1 is protective of bone mass under mild cold stress conditions.

    Science.gov (United States)

    Nguyen, Amy D; Lee, Nicola J; Wee, Natalie K Y; Zhang, Lei; Enriquez, Ronaldo F; Khor, Ee Cheng; Nie, Tao; Wu, Donghai; Sainsbury, Amanda; Baldock, Paul A; Herzog, Herbert

    2018-01-01

    Brown adipose tissue (BAT), largely controlled by the sympathetic nervous system (SNS), has the ability to dissipate energy in the form of heat through the actions of uncoupling protein-1 (UCP-1), thereby critically influencing energy expenditure. Besides BAT, the SNS also strongly influences bone, and recent studies have demonstrated a positive correlation between BAT activity and bone mass, albeit the interactions between BAT and bone remain unclear. Here we show that UCP-1 is critical for protecting bone mass in mice under conditions of permanent mild cold stress for this species (22°C). UCP-1 -/- mice housed at 22°C showed significantly lower cancellous bone mass, with lower trabecular number and thickness, a lower bone formation rate and mineralising surface, but unaltered osteoclast number, compared to wild type mice housed at the same temperature. UCP-1 -/- mice also displayed shorter femurs than wild types, with smaller cortical periosteal and endocortical perimeters. Importantly, these altered bone phenotypes were not observed when UCP-1 -/- and wild type mice were housed in thermo-neutral conditions (29°C), indicating a UCP-1 dependent support of bone mass and bone formation at the lower temperature. Furthermore, at 22°C UCP-1 -/- mice showed elevated hypothalamic expression of neuropeptide Y (NPY) relative to wild type, which is consistent with the lower bone formation and mass of UCP-1 -/- mice at 22°C caused by the catabolic effects of hypothalamic NPY-induced SNS modulation. The results from this study suggest that during mild cold stress, when BAT-dependent thermogenesis is required, UCP-1 activity exerts a protective effect on bone mass possibly through alterations in central NPY pathways known to regulate SNS activity. Copyright © 2016. Published by Elsevier Inc.

  15. Measurement of bone mineral mass in clinical perspective

    NARCIS (Netherlands)

    F.N.R. van Berkum (Frank)

    1991-01-01

    textabstractIt has now became possible to measure the bone mineral content in the axial as well as the peripheral skeleton. Moreover, with the use of computed tomography a selective assessment can be made of cancellous (trabecular) versus cortical bone mineral density. These technical

  16. Low bone mass in behaviorally HIV-infected young men on antiretroviral therapy: adolescent trials network (ATN) study 021B

    Science.gov (United States)

    Peak bone mass is achieved in adolescence/early adulthood and is the key determinant of bone mass in adulthood. We evaluated the association of bone mass with HIV infection and antiretroviral therapy (ART) during this critical period among behaviorally HIV infected young men and seronegative control...

  17. Toll-Like Receptor 4 Signaling Pathway Mediates Inhalant Organic Dust-Induced Bone Loss.

    Directory of Open Access Journals (Sweden)

    Elizabeth Staab

    Full Text Available Agriculture workers have increased rates of airway and skeletal disease. Inhalant exposure to agricultural organic dust extract (ODE induces bone deterioration in mice; yet, mechanisms underlying lung-bone crosstalk remain unclear. Because Toll-like receptor 2 (TLR2 and TLR4 are important in mediating the airway consequences of ODE, this study investigated their role in regulating bone responses. First, swine facility ODE stimulated wild-type (WT bone marrow macrophages to form osteoclasts, and this finding was inhibited in TLR4 knock-out (KO, but not TLR2 KO cells. Next, using an established intranasal inhalation exposure model, WT, TLR2 KO and TLR4 KO mice were treated daily with ODE or saline for 3 weeks. ODE-induced airway neutrophil influx and cytokine/chemokine release were similarly reduced in TLR2 and TLR4 KO animals as compared to WT mice. Utilizing micro-computed tomography (CT, analysis of tibia showed loss of bone mineral density, volume and deterioration of bone micro-architecture and mechanical strength induced by ODE in WT mice were significantly reduced in TLR4 but not TLR2 KO animals. Bone marrow osteoclast precursor cell populations were analyzed by flow cytometry from exposed animals. In WT animals, exposure to inhalant ODE increased osteoclast precursor cell populations as compared to saline, an effect that was reduced in TLR4 but not TLR2 KO mice. These results show that TLR2 and TLR4 pathways mediate ODE-induced airway inflammation, but bone deterioration consequences following inhalant ODE treatment is strongly dependent upon TLR4. Thus, the TLR4 signaling pathway appears critical in regulating the lung-bone inflammatory axis to microbial component-enriched organic dust exposures.

  18. Arctic Ground Squirrels Limit Bone Loss during the Prolonged Physical Inactivity Associated with Hibernation.

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    Wojda, Samantha J; Gridley, Richard A; McGee-Lawrence, Meghan E; Drummer, Thomas D; Hess, Ann; Kohl, Franziska; Barnes, Brian M; Donahue, Seth W

    2016-01-01

    Prolonged disuse (e.g., physical inactivity) typically results in increased bone porosity, decreased mineral density, and decreased bone strength, leading to increased fracture risk in many mammals. However, bears, marmots, and two species of ground squirrels have been shown to preserve macrostructural bone properties and bone strength during long seasons of hibernation while they remain mostly inactive. Some small hibernators (e.g., 13-lined ground squirrels) show microstructural bone loss (i.e., osteocytic osteolysis) during hibernation, which is not seen in larger hibernators (e.g., bears and marmots). Arctic ground squirrels (Urocitellus parryii) are intermediate in size between 13-lined ground squirrels and marmots and are perhaps the most extreme rodent hibernator, hibernating for up to 8 mo annually with body temperatures below freezing. The goal of this study was to quantify the effects of hibernation and inactivity on cortical and trabecular bone properties in arctic ground squirrels. Cortical bone geometrical properties (i.e., thickness, cross-sectional area, and moment of inertia) at the midshaft of the femur were not different in animals sampled over the hibernation and active seasons. Femoral ultimate stress tended to be lower in hibernators than in summer animals, but toughness was not affected by hibernation. The area of osteocyte lacunae was not different between active and hibernating animals. There was an increase in osteocytic lacunar porosity in the hibernation group due to increased lacunar density. Trabecular bone volume fraction in the proximal tibia was unexpectedly greater in the hibernation group than in the active group. This study shows that, similar to other hibernators, arctic ground squirrels are able to preserve many bone properties during hibernation despite being physically inactive for up to 8 mo.

  19. Loss of the PGE2 receptor EP1 enhances bone acquisition, which protects against age and ovariectomy-induced impairments in bone strength.

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    Zhang, Minjie; Feigenson, Marina; Sheu, Tzong-jen; Awad, Hani A; Schwarz, Edward M; Jonason, Jennifer H; Loiselle, Alayna E; O'Keefe, Regis J

    2015-03-01

    PGE2 exerts anabolic and catabolic effects on bone through the discrete actions of four prostanoid receptors (EP1-4). We have previously demonstrated that loss EP1 accelerates fracture repair by enhancing bone formation. In the present study we defined the role of EP1 in bone maintenance and homeostasis during aging and in response to ovariectomy. The femur and L4 vertebrae of wild type (WT) and EP1(-/-) mice were examined at 2-months, 6-months, and 1-year of age, and in WT and EP1(-/-) mice following ovariectomy (OVX) or sham surgery. Bone volume fraction, trabecular architecture and mechanical properties were maintained during aging in EP1(-/-) mice to a greater degree than age-matched WT mice. Moreover, significant increases in bone formation rate (BFR) (+60%) and mineral apposition rate (MAR) (+50%) were observed in EP1(-/-), relative to WT, while no change in osteoclast number and osteoclast surface were observed. Following OVX, loss of EP1 was protective against bone loss in both femur and L4 vertebrae, with increased bone volume/total volume (BV/TV) (+32% in femur) and max load at failure (+10% in femur) relative to WT OVX, likely resulting from the increased bone formation rate that was observed in these mice. Taken together these studies identify inhibition of EP1 as a potential therapeutic approach to suppress bone loss in aged or post-menopausal patients. Copyright © 2014 Elsevier Inc. All rights reserved.

  20. Evaluation of the Stress Induced in Tooth, Periodontal Ligament & Alveolar Bone with Varying Degrees of Bone Loss During Various Types of Orthodontic Tooth Movements.

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    Agarwal, Anupam; Mahajan, Shalu; Verma, Santosh; Bhardwaj, Preeti; Sharma, Geeta

    2016-02-01

    The force applied on to a tooth with periodontal bone loss may generate different magnitude and pattern of stresses in the periodontium when compared to a tooth with no bone loss & under the same force system. The intensity of the forces and moment to force ratios needed to be applied during an Orthodontic treatment must be adapted to obtain the same movement as in a tooth with a healthy periodontal support. Evaluation and assessment of the stress distribution during various types of Orthodontic tooth movement on application of Orthodontic force, at various levels of alveolar bone loss; & determination of the most ideal force system producing the Optimum Stress (i.e., stress within optimum range), uniformly (conducive to bodily movement of maxillary canine with varying degrees of bone loss). A human maxillary canine tooth of right side was simulated by means of Finite Element Method (FEM). Five different models were constructed with bone loss ranging from 0mm in model 1, to 8mm in model 5 (progressing at 2mm per model). Ten different loading conditions were applied on these models and the stress generated was charted at various occluso-gingival levels and surfaces around the tooth. The evaluation and assessment of the stress distribution during various types of Orthodontic tooth movement on application of Orthodontic force, at various levels of alveolar bone loss was done. The results showed that there was a high positive correlation between the increase in bone loss & the stress generated, suggesting an elevation in the stress with advancing bone loss. Additionally, the type of tooth movement was found to be changed with bone loss. During the determination of ideal force system it was found that the centre of resistance of the canine migrated apically with bone loss and an increase in the moment to force ratio (Mc:F) was required to control the root position in these cases. A high positive correlation exists between the increase in bone loss and the stress

  1. High dietary calcium intake does not counteract disuse-induced bone loss

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    Baecker, N.; Boese, A.; Smith, S. M.; Heer, M.

    Reduction of mechanical stress on bone inhibits osteoblast-mediated bone formation, increases osteoclast-mediated bone resorption, and leads to what has been called disuse osteoporosis. Prolonged therapeutic bed rest, immobilization and space flight are common causes of disuse osteoporosis. There are sufficient data supporting the use of calcium in combination with vitamin D in the prevention and treatment of postmenopausal osteoporosis. In our study we examined the potential of high dietary calcium intake as a nutrition therapy for disuse-induced bone loss during head-down bed rest in healthy young men. In 2 identical metabolic ward, head-down bed rest (HDBR) experiments (crossover design), we studied the effect of high dietary calcium intake (2000 mg/d) in comparison to the recommended calcium intake of 1000 mg/d on markers of bone turnover. Experiment A (EA) was a 6-day randomized, controlled HDBR study. Experiment B (EB) was a 14-day randomized, controlled HDBR study. In both experiments, the test subjects stayed under well-controlled environmental conditions in our metabolic ward. Subjects' diets in the relevant study phases (HDBR versus Ambulatory Control) of EA and EB were identical except for the calcium intake. The subjects obtained 2000 mg/d Calcium in EA and 2000 mg/d in EB. Blood was drawn at baseline, before entering the relevant intervention period, on day 5 in study EA, and on days 6, 11 and 14 in study EB. Serum calcium, bone formation markers - Procollagen-I-C-Propeptide (PICP) and bone alkaline phosphatase (bAP) were analyzed in serum. 24h-urine was collected throughout the studies for determination of the excretion of calcium (UCaV) and a bone resorption marker, C-terminal telopeptide of collagen type I (UCTX). In both studies, serum calcium levels were unchanged. PICP tended to decrease in EA (p=0.08). In EB PICP decreased significantly over time (p=0.003) in both the control and HDBR periods, and tended to further decrease in the HDBR period (p

  2. Swimming and bone: Is low bone mass due to hypogravity alone or does other physical activity influence it?

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    Gómez-Bruton, A; González-Agüero, A; Gómez-Cabello, A; Matute-Llorente, A; Casajús, J A; Vicente-Rodríguez, G

    2016-05-01

    Swimming during adolescence has shown neutral or even negative effects on bone mass. Nevertheless, it is still unknown if these effects are due to swimming or to other factors, such as sedentary behaviors. Three objectives were described (1) to measure objective physical activity (PA) additional to swimming performed by adolescent swimmers (SWI) and compare it to that performed by normo-active controls (CG), (2) to describe the relationship between objectively measured PA and bone mass, and (3) to compare bone mass of swimmers that meet the World Health Organization PA guidelines (active) WHO and those that do not (inactive). A total of 71 SWI (33 females) and 41 CG (17 females) wore an accelerometer for at least 4 days. PA was expressed as the amount of time (minutes/day) in each intensity [sedentary/light/moderate or vigorous (VPA), and the sum of moderate and vigorous (MVPA)]. Using the cutoff points proposed by Vanhelst et al. SWI were classified as active or inactive according to whether they reached 60 min of weight-bearing MVPA per day or not. Bone mineral density (BMD) was measured by dual energy X-ray absorptiometry, and bone strength values were calculated with peripheral quantitative computed tomography. Differences in PA intensities were calculated between SWI and CG. The relation of VPA to bone mass was studied in the SWI. Male-SWI spend less time in VPA and MVPA than male-GC, which partly explains the lower BMD values in SWI than CG. Swimming may displace weight-bearing VPA with serious implications on bone health.

  3. Global-scale hydrological response to future glacier mass loss

    Science.gov (United States)

    Huss, Matthias; Hock, Regine

    2018-02-01

    Worldwide glacier retreat and associated future runoff changes raise major concerns over the sustainability of global water resources1-4, but global-scale assessments of glacier decline and the resulting hydrological consequences are scarce5,6. Here we compute global glacier runoff changes for 56 large-scale glacierized drainage basins to 2100 and analyse the glacial impact on streamflow. In roughly half of the investigated basins, the modelled annual glacier runoff continues to rise until a maximum (`peak water') is reached, beyond which runoff steadily declines. In the remaining basins, this tipping point has already been passed. Peak water occurs later in basins with larger glaciers and higher ice-cover fractions. Typically, future glacier runoff increases in early summer but decreases in late summer. Although most of the 56 basins have less than 2% ice coverage, by 2100 one-third of them might experience runoff decreases greater than 10% due to glacier mass loss in at least one month of the melt season, with the largest reductions in central Asia and the Andes. We conclude that, even in large-scale basins with minimal ice-cover fraction, the downstream hydrological effects of continued glacier wastage can be substantial, but the magnitudes vary greatly among basins and throughout the melt season.

  4. Marginal bone loss and dental implant failure may be increased in smokers.

    Science.gov (United States)

    Veitz-Keenan, Analia

    2016-03-01

    An electronic search was performed in PubMed, Web of Science and the Cochrane Central Register of Controlled Trials up to February 2015. References of included studies were also searched. No language restrictions were applied. Study selection: Prospective, retrospective and randomised clinical trials that compared marginal bone loss and failure rates between smokers and non-smokers. Implant failure was considered as total loss of the implant. Studies with patients who had periodontal disease prior to treatment or who had metabolic diseases were excluded. Two reviewers were involved in the research and screening process and disagreements were resolved by discussion. The quality of the studies was analysed using the Newcastle-Ottawa scale for non-randomised clinical trials. Data extracted from the studies included, when available: follow up period, number of subjects, smoking status, number of implants placed, implant system, implant length and diameter, healing period, antibiotics and mouth-rinse use, marginal bone loss, failure rate and drop-outs. For binary outcomes (implant failure) the estimate of the intervention effect was expressed in the form of an odds ratio (OR) with the confidence interval (CI) of 95%. For continuous outcomes (marginal bone loss) the average and standard deviation (SD) were used to calculate the standardised mean difference with a 95% CI. Meta-analysis was performed for studies with similar outcomes, I(2) a statistical test was used to express the heterogeneity among the studies. Publication bias was explored as well. A total of 15 observational studies were included in the review. The number of participants ranged from 60 to 1727 and the average age was 52.5 years. The follow-up period ranged from eight to 240 months. The total number of implants placed was 5840 in smokers and 14,683 in non-smokers. The Branemak system, (Noble Biocare AB, Goteborg, Sweden), was the most commonly used implant system. There was a statistically significant

  5. Dihydromyricetin Protects against Bone Loss in Ovariectomized Mice by Suppressing Osteoclast Activity

    Directory of Open Access Journals (Sweden)

    Libo Zhao

    2017-12-01

    Full Text Available Dihydromyricetin (DMY, the main flavonoid component of Ampelopsis grossedentata, possesses pharmacological activities useful for treatment of diseases associated with inflammation and oxidative damage. Because osteoclasts are often involved in chronic low-grade systemic inflammation and oxidative damage, we hypothesized that DMY may be an effective treatment for osteoclast-related diseases. The effects of DMY on osteoclast formation and activity were examined in vitro. Female C57BL/6 mice were ovariectomized to mimic menopause-induced bone loss and treated with DMY, and femur samples were subjected to bone structure and histological analysis, serum biochemical indicators were also measured. DMY suppressed the activation of nuclear factor-κB, c-Fos and mitogen-activated protein kinase, and prevented production of reactive oxygen species. DMY decreased expression of osteoclast-specific genes, including Trap, Mmp-9, Cathepsin K, C-Fos, Nfatc1, and Rank. In addition, DMY prevented bone loss and decreased serum levels of tumor necrosis factor-α, interleukin-1β, and interleukin-6, and with a decrease in the ratio between receptor activator of nuclear factor-κB (RANK ligand (RANKL and osteoprotegerin (OPG in vivo. These findings demonstrate that DMY attenuates bone loss and inhibits osteoclast formation and activity through modulation of multiple pathways both upstream and downstream of RANKL signaling. DMY may thus be a useful option for treatment of osteoclast-related diseases such as rheumatoid arthritis and osteoporosis.

  6. Spinal bone loss in postmenopausal women supplemented with calcium and trace minerals.

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    Strause, L; Saltman, P; Smith, K T; Bracker, M; Andon, M B

    1994-07-01

    The effects of calcium supplementation (as calcium citrate malate, 1000 mg elemental Ca/d) with and without the addition of zinc (15.0 mg/d), manganese (5.0 mg/d) and copper (2.5 mg/d) on spinal bone loss (L2-L4 vertebrae) was evaluated in healthy older postmenopausal women (n = 59, mean age 66 y) in a 2-y, double-blind, placebo-controlled trial. Changes (mean +/- SEM) in bone density were -3.53 +/- 1.24% (placebo), -1.89 +/- 1.40% (trace minerals only), -1.25 +/- 1.46% (calcium only) and 1.48 +/- 1.40% (calcium plus trace minerals). Bone loss relative to base-line value was significant (P = 0.0061) in the placebo group but not in the groups receiving trace minerals alone, calcium alone, or calcium plus trace minerals. The only significant group difference occurred between the placebo group and the group receiving calcium plus trace minerals (P = 0.0099). These data suggest that bone loss in calcium-supplemented, older postmenopausal women can be further arrested by concomitant increases in trace mineral intake.

  7. Alveolar bone loss associated to periodontal disease in lead intoxicated rats under environmental hypoxia.

    Science.gov (United States)

    Terrizzi, Antonela R; Fernandez-Solari, Javier; Lee, Ching M; Bozzini, Clarisa; Mandalunis, Patricia M; Elverdin, Juan C; Conti, María Ines; Martínez, María Pilar

    2013-10-01

    Previously reported studies from this laboratory revealed that rats chronically intoxicated with lead (Pb) under hypoxic conditions (HX) impaired growth parameters and induced damages on femoral and mandibular bones predisposing to fractures. We also described periodontal inflammatory processes under such experimental conditions. Periodontitis is characterised by inflammation of supporting tissues of the teeth that result in alveolar bone loss. The existence of populations living at high altitudes and exposed to lead contamination aimed us to establish the macroscopic, biochemical and histological parameters consistent with a periodontal disease in the same rat model with or without experimental periodontitis (EP). Sixty female rats were divided into: Control; Pb (1000ppm of lead acetate in drinking water); HX (506mbar) and PbHX (both treatments simultaneously). EP was induced by placing ligatures around the molars of half of the rats during the 14 days previous to the autopsy. Hemi-mandibles were extracted to evaluate bone loss by histomorphometrical techniques. TNFα plasmatic concentration was greater (plead intoxication under hypoxic environment enhanced not only alveolar bone loss but also systemic and oral tissues inflammatory parameters, which could aggravate the physiopathological alterations produced by periodontal disease. Copyright © 2013 Elsevier Ltd. All rights reserved.

  8. Nrf2 regulates mass accrual and the antioxidant endogenous response in bone differently depending on the sex and age.

    Directory of Open Access Journals (Sweden)

    Gretel Gisela Pellegrini

    Full Text Available Accumulation of reactive oxygen species (ROS is an important pathogenic mechanism underling the loss of bone mass and strength with aging and other conditions leading to osteoporosis. The transcription factor erythroid 2-related factor2 (Nrf2 plays a central role in activating the cellular response to ROS. Here, we examined the endogenous response of bone regulated by Nrf2, and its relationship with bone mass and architecture in the male and female murine skeleton. Young (3 month-old and old (15 month-old Nrf2 knockout (KO mice of either sex exhibited the expected reduction in Nrf2 mRNA expression compared to wild type (WT littermates. Nrf2 deletion did not lead to compensatory increase in Nrf1 or Nrf3, other members of this transcription factor family; and instead, Nrf1 expression was lower in KO mice. Compared to the respective WT littermate controls, female KO mice, young and old, exhibited lower expression of both detoxifying and antioxidant enzymes; young male KO mice, displayed lower expression of detoxifying enzymes but not antioxidant enzymes; and old male KO mice showed no differences in either detoxifying or antioxidant enzymes. Moreover, old male WT mice exhibited lower Nrf2 levels, and consequently lower expression of both detoxifying and antioxidant enzymes, compared to old female WT mice. These endogenous antioxidant responses lead to delayed rate of bone acquisition in female KO mice and higher bone acquisition in male KO mice as quantified by DXA and μCT, demonstrating that Nrf2 is required for full bone accrual in the female skeleton but unnecessary and even detrimental in the male skeleton. Therefore, Nrf2 regulates the antioxidant endogenous response and bone accrual differently depending on sex and age. These findings suggest that therapeutic interventions that target Nrf2 could be developed to enhance the endogenous antioxidant response in a sex- and age-selective manner.

  9. Nrf2 regulates mass accrual and the antioxidant endogenous response in bone differently depending on the sex and age

    Science.gov (United States)

    Pellegrini, Gretel Gisela; Cregor, Meloney; McAndrews, Kevin; Morales, Cynthya Carolina; McCabe, Linda Doyle; McCabe, George P.; Peacock, Munro; Burr, David; Weaver, Connie; Bellido, Teresita

    2017-01-01

    Accumulation of reactive oxygen species (ROS) is an important pathogenic mechanism underling the loss of bone mass and strength with aging and other conditions leading to osteoporosis. The transcription factor erythroid 2-related factor2 (Nrf2) plays a central role in activating the cellular response to ROS. Here, we examined the endogenous response of bone regulated by Nrf2, and its relationship with bone mass and architecture in the male and female murine skeleton. Young (3 month-old) and old (15 month-old) Nrf2 knockout (KO) mice of either sex exhibited