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Sample records for increased bone strength

  1. Chemotherapy decreases epiphyseal strength and increases bone fracture risk

    NARCIS (Netherlands)

    Van Leeuwen, BL; Verkerke, GJ; Hartel, RM; Sluiter, WJ; Kamps, WA; Jansen, HWB; Hoekstra, HJ

    To establish the effect of three frequently used chemotherapeutic agents in childhood cancer on the skeleton, growing male Wistar rats were studied. Treatment with doxorubicin, methotrexate, and cisplatin reduces the proximal tibial growth plate shear strength because of a decreased surface area and

  2. The effects of honey (Apis dorsata) supplements on increased bone strength in ovariectomized rat as animal model of osteoporosis

    Science.gov (United States)

    Yudaniayanti, Ira Sari; Primarizky, Hardany; Nangoi, Lianny

    2018-04-01

    Osteoporosis is a chronic skeletal disease characterized by low bone mass and microarchitectural deterioration with a consequent increase in bone fragility and fracture risk. The aim of the study was to evaluate the effects of honey (Apis dorsata) supplements on increased bone strength in ovariectomized rat as animal models of osteoporosis. Twenty female rats at 3 months of age, weighing 150-200 g were used in the study. The rats were divided into five groups (n=4) : Sham operation group (SH); ovariectomy group no treatment(OVX); ovariectomy with treatment Apis dorsata 1g/Kg BW (AD-1); ovariectomy with treatment Apis dorsata 2g/Kg BW (AD-2); ovariectomy with treatment Apis dorsata 4g/Kg BW (AD-3). The treatment started to be given the next day after ovariectomy operation for 12 weeks. The Rats were sacrified within 12 weeks, and then the right femur were taken bone strength test. Based on the statistical analysis of the bone strength test, the greatest score belongs to the Sham operation group (SH) that have significant difference (p0,05). In conclusion, honey (Apis dorsata) supplements has the effect of increasing bone strength in ovariectomized rat as animal models of osteoporosis, so that honey (Apis dorsata) supplements has the potential to be used as an alternative treatment for osteoporosis.

  3. Is a school-based physical activity intervention effective for increasing tibial bone strength in boys and girls?

    Science.gov (United States)

    Macdonald, Heather M; Kontulainen, Saija A; Khan, Karim M; McKay, Heather A

    2007-03-01

    This 16-month randomized, controlled school-based study compared change in tibial bone strength between 281 boys and girls participating in a daily program of physical activity (Action Schools! BC) and 129 same-sex controls. The simple, pragmatic intervention increased distal tibia bone strength in prepubertal boys; it had no effect in early pubertal boys or pre or early pubertal girls. Numerous school-based exercise interventions have proven effective for enhancing BMC, but none have used pQCT to evaluate the effects of increased loading on bone strength during growth. Thus, our aim was to determine whether a daily program of physical activity, Action Schools! BC (AS! BC) would improve tibial bone strength in boys and girls who were pre- (Tanner stage 1) or early pubertal (Tanner stage 2 or 3) at baseline. Ten schools were randomized to intervention (INT, 7 schools) or control (CON, 3 schools). The bone-loading component of AS! BC included a daily jumping program (Bounce at the Bell) plus 15 minutes/day of classroom physical activity in addition to regular physical education. We used pQCT to compare 16-month change in bone strength index (BSI, mg2/mm4) at the distal tibia (8% site) and polar strength strain index (SSIp, mm3) at the tibial midshaft (50% site) in 281 boys and girls participating in AS! BC and 129 same-sex controls. We used a linear mixed effects model to analyze our data. Children were 10.2+/-0.6 years at baseline. Intervention boys tended to have a greater increase in BSI (+774.6 mg2/mm4; 95% CI: 672.7, 876.4) than CON boys (+650.9 mg2/mm4; 95% CI: 496.4, 805.4), but the difference was only significant in prepubertal boys (p=0.03 for group x maturity interaction). Intervention boys also tended to have a greater increase in SSIp (+198.6 mm3; 95% CI: 182.9, 214.3) than CON boys (+177.1 mm3; 95% CI: 153.5, 200.7). Change in BSI and SSIp was similar between CON and INT girls. Our findings suggest that a simple, pragmatic program of daily activity

  4. [Calcium and bone metabolism across women's life stages. Exercise and sport to increase bone strength in accordance with female lifecycle.

    Science.gov (United States)

    Iwamoto, Jun

    Among females who require the strategies for preventing osteoporosis, appropriate exercise and sport through all their life are important to increase or maintain bone mass. However, the type of exercise and sport applied to females is different in accordance with the lifecycle. Jumping exercise increases bone mineral content(BMC)in prepubescent children(premenarcheal girls). Bone mineral density(BMD)is higher in adolescent athletes who are engaged in weight-bearing activities. Jumping exercise, muscle strengthening exercise, and weight-bearing plus muscle strengthening exercises increase BMD in young adults and premenopausal women. Walking, aerobic weight-bearing exercise, muscle strengthening exercise, and weight-bearing plus muscle strengthening exercises maintain or increase BMD in postmenopausal women. Thus, appropriate exercise and sport in accordance with the lifecycle are important strategies for preventing osteoporosis in females.

  5. Six months of disuse during hibernation does not increase intracortical porosity or decrease cortical bone geometry, strength, or mineralization in black bear (Ursus americanus) femurs

    OpenAIRE

    McGee-Lawrence, Meghan E.; Wojda, Samantha J.; Barlow, Lindsay N.; Drummer, Thomas D.; Bunnell, Kevin; Auger, Janene; Black, Hal L.; Donahue, Seth W.

    2009-01-01

    Disuse typically uncouples bone formation from resorption, leading to bone loss which compromises bone mechanical properties and increases the risk of bone fracture. Previous studies suggest that bears can prevent bone loss during long periods of disuse (hibernation), but small sample sizes have limited the conclusions that can be drawn regarding the effects of hibernation on bone structure and strength in bears. Here we quantified the effects of hibernation on structural, mineral, and mechan...

  6. Adult Brtl/+ mouse model of osteogenesis imperfecta demonstrates anabolic response to sclerostin antibody treatment with increased bone mass and strength.

    Science.gov (United States)

    Sinder, B P; White, L E; Salemi, J D; Ominsky, M S; Caird, M S; Marini, J C; Kozloff, K M

    2014-08-01

    Treatments to reduce fracture rates in adults with osteogenesis imperfecta are limited. Sclerostin antibody, developed for treating osteoporosis, has not been explored in adults with OI. This study demonstrates that treatment of adult OI mice respond favorably to sclerostin antibody therapy despite retention of the OI-causing defect. Osteogenesis imperfecta (OI) is a heritable collagen-related bone dysplasia, characterized by brittle bones with increased fracture risk. Although OI fracture risk is greatest before puberty, adults with OI remain at risk of fracture. Antiresorptive bisphosphonates are commonly used to treat adult OI, but have shown mixed efficacy. New treatments which consistently improve bone mass throughout the skeleton may improve patient outcomes. Neutralizing antibodies to sclerostin (Scl-Ab) are a novel anabolic therapy that have shown efficacy in preclinical studies by stimulating bone formation via the canonical wnt signaling pathway. The purpose of this study was to evaluate Scl-Ab in an adult 6 month old Brtl/+ model of OI that harbors a typical heterozygous OI-causing Gly > Cys substitution on Col1a1. Six-month-old WT and Brtl/+ mice were treated with Scl-Ab (25 mg/kg, 2×/week) or Veh for 5 weeks. OCN and TRACP5b serum assays, dynamic histomorphometry, microCT and mechanical testing were performed. Adult Brtl/+ mice demonstrated a strong anabolic response to Scl-Ab with increased serum osteocalcin and bone formation rate. This anabolic response led to improved trabecular and cortical bone mass in the femur. Mechanical testing revealed Scl-Ab increased Brtl/+ femoral stiffness and strength. Scl-Ab was successfully anabolic in an adult Brtl/+ model of OI.

  7. Is increase in bone mineral content caused by increase in skeletal muscle mass/strength in adult patients with GH-treated GH deficiency? A systematic literature analysis

    DEFF Research Database (Denmark)

    Klefter, O.; Feldt-Rasmussen, U.

    2009-01-01

    to a muscle modulating effect, and if treatment with GH would primarily increase muscle mass and strength with a secondary increase in BMD/BMC, thus supporting the present physiological concept that mass and strength of bones are mainly determined by dynamic loads from the skeletal muscles. METHOD: We...... performed a systematic literature analysis, including 51 clinical trials published between 1996 and 2008, which had studied the development in muscle mass, muscle strength, BMD, and/or BMC in GH-treated adult GHD patients. RESULTS: GH therapy had an anabolic effect on skeletal muscle. The largest increase...... in muscle mass occurred during the first 12 months of therapy. Most trials measuring BMD/BMC reported significant increases from baseline values. The significant increases in BMD/BMC occurred after 12-18 months of treatment, i.e. usually later than the increases in muscle parameters. Only seven trials...

  8. Is increase in bone mineral content caused by increase in skeletal muscle mass/strength in adult patients with GH-treated GH deficiency?

    DEFF Research Database (Denmark)

    Klefter, Oliver; Feldt-Rasmussen, Ulla

    2009-01-01

    to a muscle modulating effect, and if treatment with GH would primarily increase muscle mass and strength with a secondary increase in BMD/BMC, thus supporting the present physiological concept that mass and strength of bones are mainly determined by dynamic loads from the skeletal muscles. METHOD: We...... performed a systematic literature analysis, including 51 clinical trials published between 1996 and 2008, which had studied the development in muscle mass, muscle strength, BMD, and/or BMC in GH-treated adult GHD patients. RESULTS: GH therapy had an anabolic effect on skeletal muscle. The largest increase...... in muscle mass occurred during the first 12 months of therapy. Most trials measuring BMD/BMC reported significant increases from baseline values. The significant increases in BMD/BMC occurred after 12-18 months of treatment, i.e. usually later than the increases in muscle parameters. Only seven trials...

  9. Calcium- and Phosphorus-Supplemented Diet Increases Bone Mass after Short-Term Exercise and Increases Bone Mass and Structural Strength after Long-Term Exercise in Adult Mice

    Science.gov (United States)

    Friedman, Michael A.; Bailey, Alyssa M.; Rondon, Matthew J.; McNerny, Erin M.; Sahar, Nadder D.; Kohn, David H.

    2016-01-01

    Exercise has long-lasting benefits to bone health that may help prevent fractures by increasing bone mass, bone strength, and tissue quality. Long-term exercise of 6–12 weeks in rodents increases bone mass and bone strength. However, in growing mice, a short-term exercise program of 3 weeks can limit increases in bone mass and structural strength, compared to non-exercised controls. Short-term exercise can, however, increase tissue strength, suggesting that exercise may create competition for minerals that favors initially improving tissue-level properties over structural-level properties. It was therefore hypothesized that adding calcium and phosphorus supplements to the diet may prevent decreases in bone mass and structural strength during a short-term exercise program, while leading to greater bone mass and structural strength than exercise alone after a long-term exercise program. A short-term exercise experiment was done for 3 weeks, and a long-term exercise experiment was done for 8 weeks. For each experiment, male 16-week old C57BL/6 mice were assigned to 4 weight-matched groups–exercise and non-exercise groups fed a control or mineral-supplemented diet. Exercise consisted of treadmill running at 12 m/min, 30 min/day for 7 days/week. After 3 weeks, exercised mice fed the supplemented diet had significantly increased tibial tissue mineral content (TMC) and cross-sectional area over exercised mice fed the control diet. After 8 weeks, tibial TMC, cross-sectional area, yield force, and ultimate force were greater from the combined treatments than from either exercise or supplemented diet alone. Serum markers of bone formation (PINP) and resorption (CTX) were both decreased by exercise on day 2. In exercised mice, day 2 PINP was significantly positively correlated with day 2 serum Ca, a correlation that was weaker and negative in non-exercised mice. Increasing dietary mineral consumption during an exercise program increases bone mass after 3 weeks and

  10. Calcium- and Phosphorus-Supplemented Diet Increases Bone Mass after Short-Term Exercise and Increases Bone Mass and Structural Strength after Long-Term Exercise in Adult Mice.

    Science.gov (United States)

    Friedman, Michael A; Bailey, Alyssa M; Rondon, Matthew J; McNerny, Erin M; Sahar, Nadder D; Kohn, David H

    2016-01-01

    Exercise has long-lasting benefits to bone health that may help prevent fractures by increasing bone mass, bone strength, and tissue quality. Long-term exercise of 6-12 weeks in rodents increases bone mass and bone strength. However, in growing mice, a short-term exercise program of 3 weeks can limit increases in bone mass and structural strength, compared to non-exercised controls. Short-term exercise can, however, increase tissue strength, suggesting that exercise may create competition for minerals that favors initially improving tissue-level properties over structural-level properties. It was therefore hypothesized that adding calcium and phosphorus supplements to the diet may prevent decreases in bone mass and structural strength during a short-term exercise program, while leading to greater bone mass and structural strength than exercise alone after a long-term exercise program. A short-term exercise experiment was done for 3 weeks, and a long-term exercise experiment was done for 8 weeks. For each experiment, male 16-week old C57BL/6 mice were assigned to 4 weight-matched groups-exercise and non-exercise groups fed a control or mineral-supplemented diet. Exercise consisted of treadmill running at 12 m/min, 30 min/day for 7 days/week. After 3 weeks, exercised mice fed the supplemented diet had significantly increased tibial tissue mineral content (TMC) and cross-sectional area over exercised mice fed the control diet. After 8 weeks, tibial TMC, cross-sectional area, yield force, and ultimate force were greater from the combined treatments than from either exercise or supplemented diet alone. Serum markers of bone formation (PINP) and resorption (CTX) were both decreased by exercise on day 2. In exercised mice, day 2 PINP was significantly positively correlated with day 2 serum Ca, a correlation that was weaker and negative in non-exercised mice. Increasing dietary mineral consumption during an exercise program increases bone mass after 3 weeks and increases

  11. Six months of disuse during hibernation does not increase intracortical porosity or decrease cortical bone geometry, strength, or mineralization in black bear (Ursus americanus) femurs.

    Science.gov (United States)

    McGee-Lawrence, Meghan E; Wojda, Samantha J; Barlow, Lindsay N; Drummer, Thomas D; Bunnell, Kevin; Auger, Janene; Black, Hal L; Donahue, Seth W

    2009-07-22

    Disuse typically uncouples bone formation from resorption, leading to bone loss which compromises bone mechanical properties and increases the risk of bone fracture. Previous studies suggest that bears can prevent bone loss during long periods of disuse (hibernation), but small sample sizes have limited the conclusions that can be drawn regarding the effects of hibernation on bone structure and strength in bears. Here we quantified the effects of hibernation on structural, mineral, and mechanical properties of black bear (Ursus americanus) cortical bone by studying femurs from large groups of male and female bears (with wide age ranges) killed during pre-hibernation (fall) and post-hibernation (spring) periods. Bone properties that are affected by body mass (e.g. bone geometrical properties) tended to be larger in male compared to female bears. There were no differences (p>0.226) in bone structure, mineral content, or mechanical properties between fall and spring bears. Bone geometrical properties differed by less than 5% and bone mechanical properties differed by less than 10% between fall and spring bears. Porosity (fall: 5.5+/-2.2%; spring: 4.8+/-1.6%) and ash fraction (fall: 0.694+/-0.011; spring: 0.696+/-0.010) also showed no change (p>0.304) between seasons. Statistical power was high (>72%) for these analyses. Furthermore, bone geometrical properties and ash fraction (a measure of mineral content) increased with age and porosity decreased with age. These results support the idea that bears possess a biological mechanism to prevent disuse and age-related osteoporoses.

  12. Sequential treatment with basic fibroblast growth factor and PTH is more efficacious than treatment with PTH alone for increasing vertebral bone mass and strength in osteopenic ovariectomized rats

    DEFF Research Database (Denmark)

    Iwaniec, U.T.; Mosekilde, Li.; Mitova-Caneva, N.G.

    2002-01-01

    The study was designed 1) to determine whether treatment with basic fibroblast growth factor (bFGF) and PTH is more efficacious than treatment with PTH alone for increasing bone mass and strength and improving trabecular microarchitecture in osteopenic ovariectomized rats, and 2) to assess whethe...

  13. Endochondral fracture healing with external fixation in the Sost knockout mouse results in earlier fibrocartilage callus removal and increased bone volume fraction and strength.

    Science.gov (United States)

    Morse, A; Yu, N Y C; Peacock, L; Mikulec, K; Kramer, I; Kneissel, M; McDonald, M M; Little, D G

    2015-02-01

    Sclerostin deficiency, via genetic knockout or anti-Sclerostin antibody treatment, has been shown to cause increased bone volume, density and strength of calluses following endochondral bone healing. However, there is limited data on the effect of Sclerostin deficiency on the formative early stage of fibrocartilage (non-bony tissue) formation and removal. In this study we extensively investigate the early fibrocartilage callus. Closed tibial fractures were performed on Sost(-/-) mice and age-matched wild type (C57Bl/6J) controls and assessed at multiple early time points (7, 10 and 14days), as well as at 28days post-fracture after bony union. External fixation was utilized, avoiding internal pinning and minimizing differences in stability stiffness, a variable that has confounded previous research in this area. Normal endochondral ossification progressed in wild type and Sost(-/-) mice with equivalent volumes of fibrocartilage formed at early day 7 and day 10 time points, and bony union in both genotypes by day 28. There were no significant differences in rate of bony union; however there were significant increases in fibrocartilage removal from the Sost(-/-) fracture calluses at day 14 suggesting earlier progression of endochondral healing. Earlier bone formation was seen in Sost(-/-) calluses over wild type with greater bone volume at day 10 (221%, p<0.01). The resultant Sost(-/-) united bony calluses at day 28 had increased bone volume fraction compared to wild type calluses (24%, p<0.05), and the strength of the fractured Sost(-/-) tibiae was greater than that that of wild type fractured tibiae. In summary, bony union was not altered by Sclerostin deficiency in externally-fixed closed tibial fractures, but fibrocartilage removal was enhanced and the resultant united bony calluses had increased bone fraction and increased strength. Crown Copyright © 2014. Published by Elsevier Inc. All rights reserved.

  14. Medullary bone and humeral breaking strength in laying hens

    International Nuclear Information System (INIS)

    Fleming, R.H.; McCormack, H.A.; McTeir, L.; Whitehead, C.C.

    1998-01-01

    To test the hypothesis that large amounts of medullary bone in the humeral diaphysis may increase breaking strength, various parameters of bone quality and quantity were examined in two large flocks of hens near end of lay. We conclude that the amount of medullary bone in the humerus of hens during the laying period influences bone strength. This medullary bone may not have any intrinsic strength, but may act by contributing to the fracture resistance of the surrounding cortical bone. Using a quantitative, low dose, radiographic technique, we can predict, from early in the laying period, those birds which will develop large amounts of medullary bone in their humeri by the end of the laying period. The formation of medullary bone in the humeral diaphysis is not at the expense of the surrounding radiographed cortical bone

  15. Analysis of bone mineral density of human bones for strength ...

    Indian Academy of Sciences (India)

    Different types of bone strength are required for various ... To statically analyse various methods to find BMD and related material ... bone study for research purpose. ..... and Dagoberto Vela Arvizo 2007 A qualitative stress analysis of a cross ...

  16. High-frequency, low-intensity vibrations increase bone mass and muscle strength in upper limbs, improving autonomy in disabled children.

    Science.gov (United States)

    Reyes, M Loreto; Hernández, Marta; Holmgren, Luz J; Sanhueza, Enrique; Escobar, Raúl G

    2011-08-01

    Disuse osteoporosis in children is a progressive disease that can affect quality of life. High-frequency, low-magnitude vibration (HFLMV) acts as an anabolic signal for bone and muscle. We undertook a prospective, randomized, double-blind, placebo-controlled clinical trial to assess the efficacy and safety of regional HFLMV in disabled children. Sixty-five children 6 to 9 year of age were randomized into three groups: placebo, 60 Hz, and 90 Hz. In the two active groups, a 0.3-g mechanical vibration was delivered to the radii and femurs for 5 minutes each day. After 6 months, the main endpoint was bone mineral density (BMD) at the ultradistal radius (UDR), 33% radii (33%R), and femoral necks (FN). Secondary endpoints were area and bone mineral content (BMC) at the UDR, 33%R, and FN; grip force of the upper and lower limbs; motor function; and PedsQL evaluation. An intention-to-treat analysis was used. Fifty-seven children (88%) completed the protocol. A significant increase was observed in the 60-Hz group relative to the other groups in BMD at the UDR (p = .011), in grip force of the upper limbs (p = .035), and in the "daily activities item" (p = .035). A mixed model to evaluate the response to intervention showed a stronger effect of 60 Hz on patients with cerebral palsy on the UDR and that between-subject variability significantly affected the response. There were no reported side effects of the intervention. This work provides evidence that regional HFLMV is an effective and safe strategy to improve bone mass, muscle strength, and possibly independence in children with motor disabilities. Copyright © 2011 American Society for Bone and Mineral Research.

  17. High-strength mineralized collagen artificial bone

    Science.gov (United States)

    Qiu, Zhi-Ye; Tao, Chun-Sheng; Cui, Helen; Wang, Chang-Ming; Cui, Fu-Zhai

    2014-03-01

    Mineralized collagen (MC) is a biomimetic material that mimics natural bone matrix in terms of both chemical composition and microstructure. The biomimetic MC possesses good biocompatibility and osteogenic activity, and is capable of guiding bone regeneration as being used for bone defect repair. However, mechanical strength of existing MC artificial bone is too low to provide effective support at human load-bearing sites, so it can only be used for the repair at non-load-bearing sites, such as bone defect filling, bone graft augmentation, and so on. In the present study, a high strength MC artificial bone material was developed by using collagen as the template for the biomimetic mineralization of the calcium phosphate, and then followed by a cold compression molding process with a certain pressure. The appearance and density of the dense MC were similar to those of natural cortical bone, and the phase composition was in conformity with that of animal's cortical bone demonstrated by XRD. Mechanical properties were tested and results showed that the compressive strength was comparable to human cortical bone, while the compressive modulus was as low as human cancellous bone. Such high strength was able to provide effective mechanical support for bone defect repair at human load-bearing sites, and the low compressive modulus can help avoid stress shielding in the application of bone regeneration. Both in vitro cell experiments and in vivo implantation assay demonstrated good biocompatibility of the material, and in vivo stability evaluation indicated that this high-strength MC artificial bone could provide long-term effective mechanical support at human load-bearing sites.

  18. Abnormal bone collagen morphology and decreased bone strength in growth hormone-deficient rats

    DEFF Research Database (Denmark)

    Lange, Martin; Qvortrup, Klaus; Svendsen, Ole Lander

    2004-01-01

    collagen morphology and bone mineralisation in cortical bone as well as bone strength in GHD rats to try to clarify the explanation for the increased fracture rate. The Dw-4 rat was used as a model for GHD. This strain of rats has an autosomal recessive disorder, reducing GH synthesis to approximately 10...

  19. Bone microarchitecture and estimated bone strength in men with active acromegaly.

    Science.gov (United States)

    Silva, Paula P B; Amlashi, Fatemeh G; Yu, Elaine W; Pulaski-Liebert, Karen J; Gerweck, Anu V; Fazeli, Pouneh K; Lawson, Elizabeth; Nachtigall, Lisa B; Biller, Beverly M K; Miller, Karen K; Klibanski, Anne; Bouxsein, Mary; Tritos, Nicholas A

    2017-11-01

    Both acromegaly and adult growth hormone deficiency (GHD) are associated with increased fracture risk. Sufficient data are lacking regarding cortical bone microarchitecture and bone strength, as assessed by microfinite element analysis (µFEA). To elucidate both cortical and trabecular bone microarchitecture and estimated bone strength in men with active acromegaly or GHD compared to healthy controls. Cross-sectional study at a clinical research center, including 48 men (16 with acromegaly, 16 with GHD and 16 healthy controls). Areal bone mineral density (aBMD), cortical and trabecular bone microarchitecture and estimated bone strength (µFEA) at the radius and tibia. aBMD was not different between the 3 groups at any skeletal site. At the radius, patients with acromegaly had greater cortical area ( P  acromegaly had lower trabecular bone density ( P  = 0.0082), but no differences in cortical bone microstructure. Compressive strength and failure load did not significantly differ between groups. These findings persisted after excluding patients with hypogonadism. Bone microarchitecture was not deficient in patients with GHD. Both cortical and trabecular microarchitecture are altered in men with acromegaly. Our data indicate that GH excess is associated with distinct effects in cortical vs trabecular bone compartments. Our observations also affirm the limitations of aBMD testing in the evaluation of patients with acromegaly. © 2017 European Society of Endocrinology.

  20. Bone strength and its determinants in peri- and postmenopausal women

    International Nuclear Information System (INIS)

    Hafeez, F.; Ahmad, M.; Hasan, S.; Khurshid, R.

    2011-01-01

    Diminished bone strength increases the frequency of osteoporosis and fragility fractures. Weight and gonadal status are important determinants of bone mass in women. This study tried to find out the bone strength and its determinants in peri- and postmenopausal age groups of women. Methods: One hundred and twenty females with age range 25 - 66 years were included in the study. According to their age and menstrual status they were divided into premenopausal (30) peri menopausal (50) and postmenopausal (40). Body Mass Index (MBI) and bone related blood parameter, serum calcium, magnesium, inorganic phosphorus, alkaline phosphatase and estradiol were estimated. Bone mineral density was taken by peripheral densitometer. Results: Blood chemical parameters were not significantly different in these groups. The p-value of serum estradiol was highly significant in peri- and postmenopausal groups. BMI was significantly high in postmenopausal as compared to pre and perimenopausal groups. Conclusion: Early menopause, low levels of oestrogen and BMI values can all affect the health of bones in elderly women. (author)

  1. Predicting vertebral bone strength by vertebral static histomorphometry

    DEFF Research Database (Denmark)

    Thomsen, Jesper Skovhus; Ebbesen, Ebbe Nils; Mosekilde, Lis

    2002-01-01

    of the entire vertebral bodies (L-2) were used for histomorphometry. The other iliac crest biopsies and the L-3 were destructively tested by compression. High correlation was found between BV/TV or Tb.Sp and vertebral bone strength (absolute value of r = 0.86 in both cases). Addition of Tb.Th significantly....... No gender-related differences were found in any of the relationships. Neither static histomorphometry nor biomechanical testing of iliac crest bone biopsies is a good predictor of vertebral bone strength.......The study investigates the relationship between static histomorphometry and bone strength of human lumbar vertebral bone. The ability of vertebral histomorphometry to predict vertebral bone strength was compared with that of vertebral densitometry, and also with histomorphometry and bone strength...

  2. Vitamin E improved bone strength and bone minerals in male rats given alcohol

    Directory of Open Access Journals (Sweden)

    Syuhada Zakaria

    2017-12-01

    Full Text Available Objective(s: Alcohol consumption induces oxidative stress on bone, which in turn increases the risk of osteoporosis. This study determined the effects of vitamin E on bone strength and bone mineral content in alcohol-induced osteoporotic rats. Materials and Methods: Three months old Sprague Dawley male rats were randomly divided into 5 groups: (I control group; (II alcohol (3 g/kg + normal saline; (III alcohol (3 g/kg + olive oil; (IV alcohol (3 g/kg + alpha-tocopherol (60 mg/kg and (V alcohol (3 g/kg + palm vitamin E (60 mg/kg. The treatment lasted for three months. Following sacrifice, the right tibia was subjected to bone biomechanical test while the lumbar (fourth and fifth lumbar and left tibia bones were harvested for bone mineral measurement. Results: Alcohol caused reduction in bone biomechanical parameters (maximum force, ultimate stress, yield stress and Young’s modulus and bone minerals (bone calcium and magnesium compared to control group (P

  3. The effect of chronic alcohol administration on bone mineral content and bone strength in male rats.

    Science.gov (United States)

    Broulík, P D; Vondrová, J; Růzicka, P; Sedlácek, R; Zíma, T

    2010-01-01

    Alcohol use has been identified as a risk factor for the development of osteoporosis. Eight male Wistar rats at two months of age were alcoho-fed (7.6 g 95 % ethanol/kg b.w. per day) to evaluate the effects of long-term administration (three months) of alcohol in drinking water. We have used a dose which is considered to be comparable to a dose of 1 liter of wine or 2.5 liters of 12(°) beer used in male adults daily. The bones were tested mechanically by a three-point bending test in a Mini Bionix (MTS) testing system. The bones from alcohol-fed rats were characterized by a reduction in bone density as well as in ash, calcium and phosphate content. In alcohol-fed rats the reduction in bone mineral density (10 %) was reflected by about 12 % reduction of mechanical strength of femur (158+/-5.5 vs. 178+/-3.2 N/mm(2)). Alcohol significantly altered femoral cortical thickness. In our experiment alcohol itself did not exert any antiandrogenic effect and it did not produce changes in the weight of seminal vesicles. Liver function test (GGT, ALP, AST) did not differ between alcohol-fed rats and control rats. Alcohol-induced bone loss is associated with increased bone resorption and decreased bone formation. These results document the efficacy of alcohol at the dose of 7.6 g 95 % ethanol/kg b.w. to cause bone loss and loss of bone mechanical strength in intact rats. The results of the present study may be interpreted as supporting the hypothesis of alcohol as a risk factor for osteoporosis.

  4. Vitamin K2 improves femoral bone strength without altering bone mineral density in gastrectomized rats.

    Science.gov (United States)

    Iwamoto, Jun; Sato, Yoshihiro; Matsumoto, Hideo

    2014-01-01

    Gastrectomy (GX) induces osteopenia in rats. The present study examined the skeletal effects of vitamin K2 in GX rats. Thirty male Sprague-Dawley rats (12 wk old) were randomized by the stratified weight method into the following three groups of 10 animals each: sham operation (control) group; GX group; and GX+oral vitamin K2 (menatetrenone, 30 mg/kg, 5 d/wk) group. Treatment was initiated at 1 wk after surgery. After 6 wk of treatment, the bone mineral content (BMC), bone mineral density (BMD), and mechanical strength of the femoral diaphysis and distal metaphysis were determined by peripheral quantitative computed tomography and mechanical strength tests, respectively. GX induced decreases in the BMC, BMD, and ultimate force of the femoral diaphysis and distal metaphysis. Vitamin K2 did not significantly influence the BMC or BMD of the femoral diaphysis or distal metaphysis in GX rats, but attenuated the decrease in the ultimate force and increased the stiffness of the femoral diaphysis. The present study showed that administration of vitamin K2 to GX rats improved the bone strength of the femoral diaphysis without altering the BMC or BMD, suggesting effects of vitamin K2 on the cortical bone quality.

  5. Mechanical response tissue analyzer for estimating bone strength

    Science.gov (United States)

    Arnaud, Sara B.; Steele, Charles; Mauriello, Anthony

    1991-01-01

    One of the major concerns for extended space flight is weakness of the long bones of the legs, composed primarily of cortical bone, that functions to provide mechanical support. The strength of cortical bone is due to its complex structure, described simplistically as cylinders of parallel osteons composed of layers of mineralized collagen. The reduced mechanical stresses during space flight or immobilization of bone on Earth reduces the mineral content, and changes the components of its matrix and structure so that its strength is reduced. Currently, the established clinical measures of bone strength are indirect. The measures are based on determinations of mineral density by means of radiography, photon absorptiometry, and quantitative computer tomography. While the mineral content of bone is essential to its strength, there is growing awareness of the limitations of the measurement as the sole predictor of fracture risk in metabolic bone diseases, especially limitations of the measurement as the sole predictor of fracture risk in metabolic bone diseases, especially osteoporosis. Other experimental methods in clinical trials that more directly evaluate the physical properties of bone, and do not require exposure to radiation, include ultrasound, acoustic emission, and low-frequency mechanical vibration. The last method can be considered a direct measure of the functional capacity of a long bone since it quantifies the mechanical response to a stimulus delivered directly to the bone. A low frequency vibration induces a response (impedance) curve with a minimum at the resonant frequency, that a few investigators use for the evaluation of the bone. An alternative approach, the method under consideration, is to use the response curve as the basis for determination of the bone bending stiffness EI (E is the intrinsic material property and I is the cross-sectional moment of inertia) and mass, fundamental mechanical properties of bone.

  6. 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......-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. 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...

  7. Increased bone radiotracer uptake in renal osteodystrophy

    Energy Technology Data Exchange (ETDEWEB)

    de Graaf, P.; Schicht, I.M.; de Graeff, J.; te Velde, J.; Kleiverda, K.; Pauwels, E.K.J.

    1982-04-01

    Bone radiotracer uptake in renal osteodystrophy was investigated in 35 dialysis patients by correlating the results of quantitative bone scintigraphy with those of biochemical and bone morphometric studies. There were highly significant correlations (P < 0.001) between the total skeletal activity and the biochemical (iPTH and alkaline phosphatase), and histologic parameters of hyperparathyroidism. These clinical results strongly suggest that increased bone turnover i.e. hyperparathyroidism, rather than osteomalacia is the major cause of increased skeletal uptake in renal osteodystrophy.

  8. Trabecular bone structure and strength - remodelling and repair

    DEFF Research Database (Denmark)

    Mosekilde, Lis; Ebbesen, Ebbe Nils; Erikstrup, Lise Tornvig

    2000-01-01

    The strength of the spinal trabecular bone declines by a factor of 4-5 from the age of 20 to 80 years. At the same time, the volumetric (apparent) density declines by a factor of only 2. This discrepancy can be explained by the known power relationship between density and strength; this power rel......; and the hydraulic effect of the bone marrow. In order to answer these questions, more in vitro and in vivo studies on human bone in relation to aging, to immobilisation, to exercise and in relation to different treatment regimens are needed.......The strength of the spinal trabecular bone declines by a factor of 4-5 from the age of 20 to 80 years. At the same time, the volumetric (apparent) density declines by a factor of only 2. This discrepancy can be explained by the known power relationship between density and strength; this power...

  9. Analysis of bone mineral density of human bones for strength ...

    Indian Academy of Sciences (India)

    The bone density (BMD) is a medical term normally referring to the amount of mineral matter per square centimetre of bones. Twenty-five patients (18 female and 7 male patients with a mean age of 71.3 years) undergoing both lumbar spine DXA scans and computed tomography imaging were evaluated to determine if HU ...

  10. Bone strength and material properties of the glenoid

    DEFF Research Database (Denmark)

    Frich, Lars Henrik; Jensen, N.C.; Odgaard, A.

    1997-01-01

    of bone specimens harvested from the central part of the glenoid subchondral area. The elastic modulus varied from approximately 100 MPa at the glenoid bare area to 400 MPa at the superior part of the glenoid. With the elastic constants used a predictor of the mechanical anisotropy, the average anisotropy...... ratio was 5.2, indicating strong anisotropy. The apparent density was an average 0.35 gr. cm-3, and the Poisson ratio averaged 0.263. According to our findings the anisotropy of the glenoid cancellous bone, details concerning the strength distribution, and the load-bearing function of the cortical shell......The quality of the glenoid bone is important to a successful total shoulder replacement. Finite element models have been used to model the response of the glenoid bone to an implanted prosthesis. Because very little is known about the bone strength and the material properties at the glenoid...

  11. Bone Mechanical Strength Estimation from Micro X-ray CT Image

    National Research Council Canada - National Science Library

    Matani, A

    2001-01-01

    ... (Bone Mineral Density), an index to evaluate the mechanical strength of the bone, does not always reflect the strength, On the other hand, micro X-ray CT has revealed the inner structure of bone, Under such circumstances...

  12. Challenges of Estimating Fracture Risk with DXA: Changing Concepts About Bone Strength and Bone Density.

    Science.gov (United States)

    Licata, Angelo A

    2015-07-01

    Bone loss due to weightlessness is a significant concern for astronauts' mission safety and health upon return to Earth. This problem is monitored with bone densitometry (DXA), the clinical tool used to assess skeletal strength. DXA has served clinicians well in assessing fracture risk and has been particularly useful in diagnosing osteoporosis in the elderly postmenopausal population for which it was originally developed. Over the past 1-2 decades, however, paradoxical and contradictory findings have emerged when this technology was widely employed in caring for diverse populations unlike those for which it was developed. Although DXA was originally considered the surrogate marker for bone strength, it is now considered one part of a constellation of factors-described collectively as bone quality-that makes bone strong and resists fracturing, independent of bone density. These characteristics are beyond the capability of routine DXA to identify, and as a result, DXA can be a poor prognosticator of bone health in many clinical scenarios. New clinical tools are emerging to make measurement of bone strength more accurate. This article reviews the historical timeline of bone density measurement (dual X-ray absorptiometry), expands upon the clinical observations that modified the relationship of DXA and bone strength, discusses some of the new clinical tools to predict fracture risk, and highlights the challenges DXA poses in the assessment of fracture risk in astronauts.

  13. Relationships between bone strength and bone quality. Three-dimensional imaging analysis in ovariectomized mice

    International Nuclear Information System (INIS)

    Wakabayashi, Suguru; Sakurai, Takashi; Kashima, Isamu

    2004-01-01

    Low-energy trauma resulting in fractures of the distal femur is often observed in elderly patients with osteoporosis; such fractures are often associated with treatment difficulties and poor prognosis. The purpose of this study was to clarify the factors that affect the bone strength of the distal femur. We used ovariectomized mice to demonstrate bone quality factors associated with deterioration of the strength of the distal femur. Ten-week old ICR-strain mice were ovariectomized or sham-ovariectomized. Total bone mineral density (BMD), total bone area, cortical BMD, cortical thickness, and trabecular BMD were measured by peripheral quantitative computed tomography in the distal metaphyseal region of the femora. As three-dimensional architectural parameters, the trabecular number, trabecular thickness (Tb.Th), trabecular separation, and connectivity density were measured in the same region by micro-computed tomography. The maximum load measured by compression testing of the distal metaphyseal region was regarded as the bone strength of each sample. No significant differences in total bone area or in cortical BMD were found between the groups. Bone strength showed the closest relationship with total BMD (r=0.834). Multiple regression analysis demonstrated that total BMD greatly depended on cortical thickness. The addition of Tb.Th to trabecular BMD markedly reflected bone strength (R=0.857), suggesting that Tb.Th affected bone strength more significantly than trabecular BMD. These findings suggested that deterioration of bone strength of the distal femur (metaphysis) was not caused by a reduction in cortical BMD, but was related to reduced cortical thickness, which reduced total BMD, and to trabecular BMD and architecture, in particular to reduced Tb.Th. (author)

  14. Glucose-dependent insulinotropic polypeptide (GIP) receptor deletion leads to reduced bone strength and quality.

    Science.gov (United States)

    Mieczkowska, Aleksandra; Irwin, Nigel; Flatt, Peter R; Chappard, Daniel; Mabilleau, Guillaume

    2013-10-01

    Bone is permanently remodeled by a complex network of local, hormonal and neuronal factors that affect osteoclast and osteoblast biology. In this context, a role for gastro-intestinal hormones has been proposed based on evidence that bone resorption dramatically falls after a meal. Glucose-dependent insulinotropic polypeptide (GIP) is one of the candidate hormones as its receptor, glucose-dependent insulinotropic polypeptide receptor (GIPR), is expressed in bone. In the present study we investigated bone strength and quality by three-point bending, quantitative x-ray microradiography, microCT, qBEI and FTIR in a GIPR knockout (GIPR KO) mouse model and compared with control wild-type (WT) animals. Animals with a deletion of the GIPR presented with a significant reduction in ultimate load (--11%), stiffness (-16%), total absorbed (-28%) and post-yield energies (-27%) as compared with WT animals. Furthermore, despite no change in bone outer diameter, the bone marrow diameter was significantly increased and as a result cortical thickness was significantly decreased by 20% in GIPR deficient animals. Bone resorption at the endosteal surface was significantly increased whilst bone formation was unchanged in GIPR deficient animals. Deficient animals also presented with a pronounced reduction in the degree of mineralization of bone matrix. Furthermore, the amount of mature cross-links of collagen matrix was significantly reduced in GIPR deficient animals and was associated with lowered intrinsic material properties. Taken together, these data support a positive effect of the GIPR on bone strength and quality. © 2013.

  15. Sclerostin Blockade and Zoledronic Acid Improve Bone Mass and Strength in Male Mice With Exogenous Hyperthyroidism.

    Science.gov (United States)

    Tsourdi, Elena; Lademann, Franziska; Ominsky, Michael S; Rijntjes, Eddy; Köhrle, Josef; Misof, Barbara M; Roschger, Paul; Klaushofer, Klaus; Hofbauer, Lorenz C; Rauner, Martina

    2017-11-01

    Hyperthyroidism in mice is associated with low bone mass, high bone turnover, and high concentrations of sclerostin, a potent Wnt inhibitor. Here, we explored the effects of either increasing bone formation with sclerostin antibodies (Scl-Ab) or reducing bone turnover with bisphosphonates on bone mass and strength in hyperthyroid mice. Twelve-week-old C57BL/6 male mice were rendered hyperthyroid using l-thyroxine (T4; 1.2 µg/mL added to the drinking water) and treated with 20 mg/kg Scl-Ab twice weekly or 100 µg/kg zoledronic acid (ZOL) once weekly or phosphate-buffered saline for 4 weeks. Hyperthyroid mice displayed a lower trabecular bone volume at the spine (-42%, P hyperthyroid mice increased trabecular bone volume at the spine by threefold and twofold, respectively. Serum bone formation and resorption markers were increased in hyperthyroid mice and suppressed by treatment with ZOL but not Scl-Ab. Trabecular bone stiffness at the lumbar vertebra was 63% lower in hyperthyroid mice (P hyperthyroidism, was increased by Scl-Ab by 71% and ZOL by 22% (both P hyperthyroid mice was restored by treatment with Scl-Ab and ZOL. Thus, bone-forming and antiresorptive drugs prevent bone loss in hyperthyroid mice via different mechanisms. Copyright © 2017 Endocrine Society.

  16. Elevated Levels of Peripheral Kynurenine Decrease Bone Strength in Rats with Chronic Kidney Disease

    Directory of Open Access Journals (Sweden)

    Bartlomiej Kalaska

    2017-10-01

    Full Text Available The diagnosis and treatment of bone disorders in patients with chronic kidney disease (CKD represent a clinical challenge. CKD leads to mineral and bone complications starting early in the course of renal failure. Recently, we have observed the positive relationship between intensified central kynurenine turnover and bone strength in rats with subtotal 5/6 nephrectomy (5/6 Nx-induced CKD. The aim of the present study was to determine the association between peripheral kynurenine pathway metabolites and bone strength in rats with 5/6 Nx-induced CKD. The animals were sacrificed 1 and 3 months after 5/6 Nx or sham operation. Nephrectomized rats presented higher concentrations of serum creatinine, urea nitrogen, and parathyroid hormone both 1 and 3 months after nephrectomy. These animals revealed higher concentrations of kynurenine and 3-hydroxykynurenine in the serum and higher gene expression of aryl hydrocarbon receptor (AhR as a physiological receptor for kynurenine and AhR-dependent cytochrome in the bone tissue. Furthermore, nephrectomy significantly increased the number of osteoclasts in the bone without affecting their resorptive activity measured in serum. These changes were particularly evident in rats 1 month after 5/6 Nx. The main bone biomechanical parameters of the tibia were unchanged between nephrectomized and sham-operated rats but were significantly increased in older compared to younger animals. A similar trend was observed for geometrical parameters measured with calipers, bone mineral density based on Archimedes' method and image of bone microarchitecture obtained from micro-computed tomography analyses of tibial cortical bone. In nephrectomized animals, peripheral kynurenine levels correlated negatively with the main parameters of bone biomechanics, bone geometry, and bone mineral density values. In conclusion, our data suggest that CKD-induced elevated levels of peripheral kynurenine cause pathological changes in bone

  17. Contributions of Severe Burn and Disuse to Bone Structure and Strength in Rats

    Science.gov (United States)

    Baer, L.A.; Wu, X.; Tou, J. C.; Johnson, E.; Wolf, S.E.; Wade, C.E.

    2012-01-01

    Burn and disuse results in metabolic and bone changes associated with substantial and sustained bone loss. Such loss can lead to an increased fracture incidence and osteopenia. We studied the independent effects of burn and disuse on bone morphology, composition and strength, and microstructure of the bone alterations 14 days after injury. Sprague-Dawley rats were randomized into four groups: Sham/Ambulatory (SA), Burn/Ambulatory (BA), Sham/Hindlimb Unloaded (SH) and Burn/Hindlimb Unloaded (BH). Burn groups received a 40% total body surface area full-thickness scald burn. Disuse by hindlimb unloading was initiated immediately following injury. Bone turnover was determined in plasma and urine. Femur biomechanical parameters were measured by three-point bending tests and bone microarchitecture was determined by microcomputed tomography (uCT). On day 14, a significant reduction in body mass was observed as a result of burn, disuse and a combination of both. In terms of bone health, disuse alone and in combination affected femur weight, length and bone mineral content. Bending failure energy, an index of femur strength, was significantly reduced in all groups and maximum bending stress was lower when burn and disuse were combined. Osteocalcin was reduced in BA compared to the other groups, indicating influence of burn. The reductions observed in femur weight, BMC, biomechanical parameters and indices of bone formation are primarily responses to the combination of burn and disuse. These results offer insight into bone degradation following severe injury and disuse. PMID:23142361

  18. Insulin resistance and bone strength: findings from the study of midlife in the United States.

    Science.gov (United States)

    Srikanthan, Preethi; Crandall, Carolyn J; Miller-Martinez, Dana; Seeman, Teresa E; Greendale, Gail A; Binkley, Neil; Karlamangla, Arun S

    2014-04-01

    Although several studies have noted increased fracture risk in individuals with type 2 diabetes mellitus (T2DM), the pathophysiologic mechanisms underlying this association are not known. We hypothesize that insulin resistance (the key pathology in T2DM) negatively influences bone remodeling and leads to reduced bone strength. Data for this study came from 717 participants in the Biomarker Project of the Midlife in the United States Study (MIDUS II). The homeostasis model assessment of insulin resistance (HOMA-IR) was calculated from fasting morning blood glucose and insulin levels. Projected 2D (areal) bone mineral density (BMD) was measured in the lumbar spine and left hip using dual-energy X-ray absorptiometry (DXA). Femoral neck axis length and width were measured from the hip DXA scans, and combined with BMD and body weight and height to create composite indices of femoral neck strength relative to load in three different failure modes: compression, bending, and impact. We used multiple linear regressions to examine the relationship between HOMA-IR and bone strength, adjusted for age, gender, race/ethnicity, menopausal transition stage (in women), and study site. Greater HOMA-IR was associated with lower values of all three composite indices of femoral neck strength relative to load, but was not associated with BMD in the femoral neck. Every doubling of HOMA-IR was associated with a 0.34 to 0.40 SD decrement in the strength indices (p<0.001). On their own, higher levels of fasting insulin (but not of glucose) were independently associated with lower bone strength. Our study confirms that greater insulin resistance is related to lower femoral neck strength relative to load. Further, we note that hyperinsulinemia, rather than hyperglycemia, underlies this relationship. Although cross-sectional associations do not prove causality, our findings do suggest that insulin resistance and in particular, hyperinsulinemia, may negatively affect bone strength relative to

  19. Development of high strength hydroxyapatite for bone tissue regeneration using nanobioactive glass composites

    Science.gov (United States)

    Shrivastava, Pragya; Dalai, Sridhar; Sudera, Prerna; Sivam, Santosh Param; Vijayalakshmi, S.; Sharma, Pratibha

    2013-02-01

    With an increasing demand of biocompatible bone substitutes for the treatment of bone diseases and bone tissue regeneration, bioactive glass composites are being tested to improvise the osteoconductive as well as osteoinductive properties. Nanobioactive glass (nBG) composites, having composition of SiO2 70 mol%, CaO 26 mol % and P2O5 4 mol% were prepared by Freeze drying method using PEG-PPG-PEG co-polymer. Polymer addition improves the mechanical strength and porosity of the scaffold of nBG. Nano Bioactive glass composites upon implantation undergo specific reactions leading to the formation of crystalline hydroxyapatite (HA). This is tested in vitro using Simulated Body Fluid (SBF). This high strength hydroxyapatite (HA) layer acts as osteoconductive in cellular environment, by acting as mineral base of bones, onto which new bone cells proliferate leading to new bone formation. Strength of the nBG composites as well as HA is in the range of cortical and cancellous bone, thus proving significant for bone tissue regeneration substitutes.

  20. Development of high strength hydroxyapatite for bone tissue regeneration using nanobioactive glass composites

    International Nuclear Information System (INIS)

    Shrivastava, Pragya; Dalai, Sridhar; Vijayalakshmi, S.; Sudera, Prerna; Sivam, Santosh Param; Sharma, Pratibha

    2013-01-01

    With an increasing demand of biocompatible bone substitutes for the treatment of bone diseases and bone tissue regeneration, bioactive glass composites are being tested to improvise the osteoconductive as well as osteoinductive properties. Nanobioactive glass (nBG) composites, having composition of SiO 2 70 mol%, CaO 26 mol % and P 2 O 5 4 mol% were prepared by Freeze drying method using PEG-PPG-PEG co-polymer. Polymer addition improves the mechanical strength and porosity of the scaffold of nBG. Nano Bioactive glass composites upon implantation undergo specific reactions leading to the formation of crystalline hydroxyapatite (HA). This is tested in vitro using Simulated Body Fluid (SBF). This high strength hydroxyapatite (HA) layer acts as osteoconductive in cellular environment, by acting as mineral base of bones, onto which new bone cells proliferate leading to new bone formation. Strength of the nBG composites as well as HA is in the range of cortical and cancellous bone, thus proving significant for bone tissue regeneration substitutes.

  1. The Effect of Weight-Bearing Exercise on the Strength of Femur Bone in Ovariectomized Rats

    Directory of Open Access Journals (Sweden)

    GH Sharifi

    2011-08-01

    Full Text Available Introduction & Objective: Fractures due to osteoporosis after menopause in women is widespread. Osteoporosis may occur in case of inadequate lack of physical activity .The aim of this study was to determine the effect of running training on femur bone strength in ovariectomized rats. Materials & Methods Forty matured Sprague Dawley rats were chosen for this study. A group of 10 were killed randomly to measure their initial femur strength. The remaining rats had ovarian surgery. After three months, in order to reach menopause period, they were randomly divided into 3 groups, including pre test, running training and control groups. The running training program was carried out for one hour a day, five days a week, for eight weeks. Femur bone strength was measured by HOUNSFIELD system. Data was analyzed by using one-way analysis of variance and dependent T- tests by the SPSS software. Results: Results of this study showed that ovariectomy leads to significant decrease of femur bone strength. On the other hand the eight weeks running training lead to significant increase of femur bone strength. Conclusion: The results of this study suggest that life style is important factors in preventing of osteoporosis and running training program had an inhibitory or reversal effect on decrease of menopause-induced femur bone strength.

  2. Mechanical strength of ceramic scaffolds reinforced with biopolymers is comparable to that of human bone

    DEFF Research Database (Denmark)

    Henriksen, S S; Ding, M; Vinther Juhl, M

    2011-01-01

    Eight groups of calcium-phosphate scaffolds for bone implantation were prepared of which seven were reinforced with biopolymers, poly lactic acid (PLA) or hyaluronic acid in different concentrations in order to increase the mechanical strength, without significantly impairing the microarchitecture....... Controls were un-reinforced calcium-phosphate scaffolds. Microarchitectural properties were quantified using micro-CT scanning. Mechanical properties were evaluated by destructive compression testing. Results showed that adding 10 or 15% PLA to the scaffold significantly increased the mechanical strength...

  3. Contributions of Raman spectroscopy to the understanding of bone strength.

    Science.gov (United States)

    Mandair, Gurjit S; Morris, Michael D

    2015-01-01

    Raman spectroscopy is increasingly commonly used to understand how changes in bone composition and structure influence tissue-level bone mechanical properties. The spectroscopic technique provides information on bone mineral and matrix collagen components and on the effects of various matrix proteins on bone material properties as well. The Raman spectrum of bone not only contains information on bone mineral crystallinity that is related to bone hardness but also provides information on the orientation of mineral crystallites with respect to the collagen fibril axis. Indirect information on collagen cross-links is also available and will be discussed. After a short introduction to bone Raman spectroscopic parameters and collection methodologies, advances in in vivo Raman spectroscopic measurements for animal and human subject studies will be reviewed. A discussion on the effects of aging, osteogenesis imperfecta, osteoporosis and therapeutic agents on bone composition and mechanical properties will be highlighted, including genetic mouse models in which structure-function and exercise effects are explored. Similarly, extracellular matrix proteins, proteases and transcriptional proteins implicated in the regulation of bone material properties will be reviewed.

  4. A study of trabecular bone strength and morphometric analysis of bone microstructure from digital radiographic image

    International Nuclear Information System (INIS)

    Han, Seung Yun; Lee, Sun Bok; Oh, Sung Ook; Heo, Min Suk; Lee, Sam Sun; Choi, Soon Chul; Park, Tae Won; Kim, Jong Dae

    2003-01-01

    To evaluate the relationship between morphometric analysis of microstructure from digital radiographic image and trabecular bone strength. One hundred eleven bone specimens with 5 mm thickness were obtained from the mandibles of 5 pigs. Digital images of specimens were taken using a direct digital intraoral radiographic system. After selection of ROI(100 x 100 pixel) within the trabecular bone, mean gray level and standard deviation were obtained. Fractal dimension and the variants of morphometric analysis (trabecular area, periphery, length of skeletonized trabeculae, number of terminal point, number of branch point) were obtained from ROI. Punch sheer strength analysis was performed using Instron (model 4465, Instron Corp., USA). The loading force (loading speed 1mm/min) was applied to ROI of bone specimen by a 2 mm diameter punch. Stress-deformation curve was obtained from the punch sheer strength analysis and maximum stress, yield stress, Young's modulus were measured. Maximum stress had a negative linear correlation with mean gray level and fractal dimension significantly (p<0.05). Yield stress had a negative linear correlation with mean gray level, periphery, fractal dimension and the length of skeletonized trabeculae significantly (p<0.05). Young's modulus had a negative linear correlation with mean gray level and fractal dimension significantly (p<0.05). The strength of cancellous bone exhibited a significantly linear relationship between mean gray level, fractal dimension and morphometric analysis. The methods described above can be easily used to evaluate bone quality clinically.

  5. [Electrical acupoint stimulation increases athletes' rapid strength].

    Science.gov (United States)

    Yang, Hua-yuan; Liu, Tang-yi; Kuai, Le; Gao, Ming

    2006-05-01

    To search for a stimulation method for increasing athletes' performance. One hundred and fifty athletes were randomly divided into a trial group and a control group, 75 athletes in each group. Acupoints were stimulated with audio frequency pulse modulated wave and multi-blind method were used to investigate effects of the electric stimulation of acupoints on 30-meter running, standing long jumping and Cybex isokinetic testing index. The acupoint electric stimulation method could significantly increase athlete's performance (P < 0.05), and the biomechanical indexes, maximal peak moment of force (P < 0.05), force moment accelerating energy (P < 0.05) and average power (P < 0.05). Electrical acupoint stimulation can enhance athlete's rapid strength.

  6. Bone mineral density and computer tomographic measurements in correlation with failure strength of equine metacarpal bones

    Directory of Open Access Journals (Sweden)

    Péter Tóth

    2014-01-01

    Full Text Available Information regarding bone mineral density and fracture characteristics of the equine metacarpus are lacking. The aim of this study was to characterize the relationship between mechanical properties of the equine metacarpal bone and its biomechanical and morphometric properties. Third metacarpal bones were extracted from horses euthanized unrelated to musculoskeletal conditions. In total, bone specimens from 26 front limbs of 13 horses (7.8 ± 5.8 years old including Lipizzaner (n = 5, Hungarian Warmblood (n = 2, Holsteiner (n = 2, Thoroughbred (n = 1, Hungarian Sporthorse (n = 1, Friesian (n = 1, and Shagya Arabian (n = 1 were collected. The horses included 7 mares, 4 stallions and 2 geldings. Assessment of the bone mineral density of the whole bone across four specific regions of interest was performed using dual-energy X-ray absorptiometry. The bones were scanned using a computer tomographic scanner to measure cross-sectional morphometric properties such as bone mineral density and cross-sectional dimensions including cortical area and cortical width. Mechanical properties (breaking force, bending strength, elastic modulus were determined by a 3-point bending test. Significant positive linear correlations were found between the breaking force and bone mineral density of the entire third metacarpal bones (P P P in vivo investigations.

  7. Chronic administration of anticonvulsants but not antidepressants impairs bone strength: clinical implications.

    Science.gov (United States)

    Gold, P W; Pavlatou, M G; Michelson, D; Mouro, C M; Kling, M A; Wong, M-L; Licinio, J; Goldstein, S A

    2015-06-02

    Major depression and bipolar disorder are associated with decreased bone mineral density (BMD). Antidepressants such as imipramine (IMIP) and specific serotonin reuptake inhibitors (SSRIs) have been implicated in reduced BMD and/or fracture in older depressed patients. Moreover, anticonvulsants such as valproate (VAL) and carbamazepine (CBZ) are also known to increase fracture rates. Although BMD is a predictor of susceptibility to fracture, bone strength is a more sensitive predictor. We measured mechanical and geometrical properties of bone in 68 male Sprague Dawley rats on IMIP, fluoxetine (FLX), VAL, CBZ, CBZ vehicle and saline (SAL), given intraperitoneally daily for 8 weeks. Distinct regions were tested to failure by four-point bending, whereas load displacement was used to determine stiffness. The left femurs were scanned in a MicroCT system to calculate mid-diaphyseal moments of inertia. None of these parameters were affected by antidepressants. However, VAL resulted in a significant decrease in stiffness and a reduction in yield, and CBZ induced a decrease in stiffness. Only CBZ induced alterations in mechanical properties that were accompanied by significant geometrical changes. These data reveal that chronic antidepressant treatment does not reduce bone strength, in contrast to chronic anticonvulsant treatment. Thus, decreased BMD and increased fracture rates in older patients on antidepressants are more likely to represent factors intrinsic to depression that weaken bone rather than antidepressants per se. Patients with affective illness on anticonvulsants may be at particularly high risk for fracture, especially as they grow older, as bone strength falls progressively with age.

  8. Skeletal Geometry and Indices of Bone Strength in Artistic Gymnasts

    Science.gov (United States)

    Dowthwaite, Jodi N.; Scerpella, Tamara A.

    2010-01-01

    This review addresses bone geometry and indices of skeletal strength associated with exposure to gymnastic loading during growth. A brief background characterizes artistic gymnastics as a mechanical loading model and outlines densitometric techniques, skeletal outcomes and challenges in assessment of skeletal adaptation. The literature on bone geometric adaptation to gymnastic loading is sparse and consists of results for disparate skeletal sites, maturity phases, gender compositions and assessment methods, complicating synthesis of an overriding view. Furthermore, most studies assess only females, with little information on males and adults. Nonetheless, gymnastic loading during growth appears to yield significant enlargement of total and cortical bone geometry (+10 to 30%) and elevation of trabecular density (+20%) in the forearm, yielding elevated indices of skeletal strength (+20 to +50%). Other sites exhibit more moderate geometric and densitometric adaptations (5 to 15%). Mode of adaptation appears to be site-specific; some sites demonstrate marked periosteal and endosteal expansion, whereas other sites exhibit negligible or moderate periosteal expansion coupled with endocortical contraction. Further research is necessary to address sex-, maturity- and bone tissue-specific adaptation, as well as maintenance of benefits beyond loading cessation. PMID:19949278

  9. Excessive growth hormone expression in male GH transgenic mice adversely alters bone architecture and mechanical strength.

    Science.gov (United States)

    Lim, S V; Marenzana, M; Hopkinson, M; List, E O; Kopchick, J J; Pereira, M; Javaheri, B; Roux, J P; Chavassieux, P; Korbonits, M; Chenu, C

    2015-04-01

    Patients with acromegaly have a higher prevalence of vertebral fractures despite normal bone mineral density (BMD), suggesting that GH overexpression has adverse effects on skeletal architecture and strength. We used giant bovine GH (bGH) transgenic mice to analyze the effects of high serum GH levels on BMD, architecture, and mechanical strength. Five-month-old hemizygous male bGH mice were compared with age- and sex-matched nontransgenic littermates controls (NT; n=16/group). Bone architecture and BMD were analyzed in tibia and lumbar vertebrae using microcomputed tomography. Femora were tested to failure using three-point bending and bone cellular activity determined by bone histomorphometry. bGH transgenic mice displayed significant increases in body weight and bone lengths. bGH tibia showed decreases in trabecular bone volume fraction, thickness, and number compared with NT ones, whereas trabecular pattern factor and structure model index were significantly increased, indicating deterioration in bone structure. Although cortical tissue perimeter was increased in transgenic mice, cortical thickness was reduced. bGH mice showed similar trabecular BMD but reduced trabecular thickness in lumbar vertebra relative to controls. Cortical BMD and thickness were significantly reduced in bGH lumbar vertebra. Mechanical testing of femora confirmed that bGH femora have decreased intrinsic mechanical properties compared with NT ones. Bone turnover is increased in favor of bone resorption in bGH tibia and vertebra compared with controls, and serum PTH levels is also enhanced in bGH mice. These data collectively suggest that high serum GH levels negatively affect bone architecture and quality at multiple skeletal sites.

  10. Dynamic locking screw improves fixation strength in osteoporotic bone: an in vitro study on an artificial bone model.

    Science.gov (United States)

    Pohlemann, Tim; Gueorguiev, Boyko; Agarwal, Yash; Wahl, Dieter; Sprecher, Christoph; Schwieger, Karsten; Lenz, Mark

    2015-04-01

    The novel dynamic locking screw (DLS) was developed to improve bone healing with locked-plate osteosynthesis by equalising construct stiffness at both cortices. Due to a theoretical damping effect, this modulated stiffness could be beneficial for fracture fixation in osteoporotic bone. Therefore, the mechanical behaviour of the DLS at the screw-bone interface was investigated in an artificial osteoporotic bone model and compared with conventional locking screws (LHS). Osteoporotic surrogate bones were plated with either a DLS or a LHS construct consisting of two screws and cyclically axially loaded (8,500 cycles, amplitude 420 N, increase 2 mN/cycle). Construct stiffness, relative movement, axial screw migration, proximal (P) and distal (D) screw pullout force and loosening at the bone interface were determined and statistically evaluated. DLS constructs exhibited a higher screw pullout force of P 85 N [standard deviation (SD) 21] and D 93 N (SD 12) compared with LHS (P 62 N, SD 28, p = 0.1; D 57 N, SD 25, p LHS (p = 0.01). DLS constructs showed significantly lower axial construct stiffness (403 N/mm, SD 21, p LHS (529 N/mm, SD 27; 0.8 mm, SD 0.04). Based on the model data, the DLS principle might also improve in vivo plate fixation in osteoporotic bone, providing enhanced residual holding strength and reducing screw cutout. The influence of pin-sleeve abutment still needs to be investigated.

  11. Association of Insulin Resistance with Bone Strength and Bone Turnover in Menopausal Chinese-Singaporean Women without Diabetes

    Science.gov (United States)

    Kalimeri, Maria; Leek, Francesca; Wang, Nan Xin; Koh, Huann Rong; Totman, John J.

    2018-01-01

    Insulin resistance (IR) is accompanied by increased areal or volumetric bone mineral density (aBMD or vBMD), but also higher fracture risk. Meanwhile, imbalances in bone health biomarkers affect insulin production. This study investigates the effect of IR on proximal femur and lumbar spine BMD, femoral neck bending, compressive and impact strength indices (Composite Strength Indices) and circulating levels of parathyroid hormone (PTH), C-telopeptide of Type I collagen (CTx-1) and 25(OH) Vitamin D3, in a cohort of 97 healthy, non-obese, menopausal Chinese-Singaporean women. Lumbar spine aBMD was inversely associated with IR and dependent on lean body mass (LBM) and age. No such associations were found for vBMD of the third lumbar vertebra, aBMD and vBMD of the proximal femur, or circulating levels of PTH, CTx-1 and 25(OH) Vitamin D3. Composite Strength Indices were inversely associated with IR and independent of LBM, but after adjusting for fat mass and age, this association remained valid only for the impact strength index. Composite Strength Indices were significantly lower in participants with a high degree of IR. Our findings on IR and Composite Strength Indices relationships were in agreement with previous studies on different cohorts, but those on IR and BMD associations were not. PMID:29710852

  12. Association of Insulin Resistance with Bone Strength and Bone Turnover in Menopausal Chinese-Singaporean Women without Diabetes

    Directory of Open Access Journals (Sweden)

    Maria Kalimeri

    2018-04-01

    Full Text Available Insulin resistance (IR is accompanied by increased areal or volumetric bone mineral density (aBMD or vBMD, but also higher fracture risk. Meanwhile, imbalances in bone health biomarkers affect insulin production. This study investigates the effect of IR on proximal femur and lumbar spine BMD, femoral neck bending, compressive and impact strength indices (Composite Strength Indices and circulating levels of parathyroid hormone (PTH, C-telopeptide of Type I collagen (CTx-1 and 25(OH Vitamin D3, in a cohort of 97 healthy, non-obese, menopausal Chinese-Singaporean women. Lumbar spine aBMD was inversely associated with IR and dependent on lean body mass (LBM and age. No such associations were found for vBMD of the third lumbar vertebra, aBMD and vBMD of the proximal femur, or circulating levels of PTH, CTx-1 and 25(OH Vitamin D3. Composite Strength Indices were inversely associated with IR and independent of LBM, but after adjusting for fat mass and age, this association remained valid only for the impact strength index. Composite Strength Indices were significantly lower in participants with a high degree of IR. Our findings on IR and Composite Strength Indices relationships were in agreement with previous studies on different cohorts, but those on IR and BMD associations were not.

  13. Vertebral body bone strength: the contribution of individual trabecular element morphology.

    Science.gov (United States)

    Parkinson, I H; Badiei, A; Stauber, M; Codrington, J; Müller, R; Fazzalari, N L

    2012-07-01

    Although the amount of bone explains the largest amount of variability in bone strength, there is still a significant proportion unaccounted for. The morphology of individual bone trabeculae explains a further proportion of the variability in bone strength and bone elements that contribute to bone strength depending on the direction of loading. Micro-CT imaging enables measurement of bone microarchitecture and subsequently mechanical strength of the same sample. It is possible using micro-CT data to perform morphometric analysis on individual rod and plate bone trabeculae using a volumetric spatial decomposition algorithm and hence determine their contribution to bone strength. Twelve pairs of vertebral bodies (T12/L1 or L4/L5) were harvested from human cadavers, and bone cubes (10 × 10 × 10 mm) were obtained. After micro-CT imaging, a volumetric spatial decomposition algorithm was applied, and measures of individual trabecular elements were obtained. Bone strength was measured in compression, where one bone specimen from each vertebral segment was tested supero-inferiorly (SI) and the paired specimen was tested antero-posteriorly (AP). Bone volume fraction was the strongest individual determinant of SI strength (r(2) = 0.77, p body bone architecture into its constituent morphological elements shows that trabecular element morphology has specific functional roles to assist in maintaining skeletal integrity.

  14. Decreasing maternal myostatin programs adult offspring bone strength in a mouse model of osteogenesis imperfecta.

    Science.gov (United States)

    Oestreich, Arin K; Kamp, William M; McCray, Marcus G; Carleton, Stephanie M; Karasseva, Natalia; Lenz, Kristin L; Jeong, Youngjae; Daghlas, Salah A; Yao, Xiaomei; Wang, Yong; Pfeiffer, Ferris M; Ellersieck, Mark R; Schulz, Laura C; Phillips, Charlotte L

    2016-11-22

    During fetal development, the uterine environment can have effects on offspring bone architecture and integrity that persist into adulthood; however, the biochemical and molecular mechanisms remain unknown. Myostatin is a negative regulator of muscle mass. Parental myostatin deficiency (Mstn tm1Sjl/+ ) increases muscle mass in wild-type offspring, suggesting an intrauterine programming effect. Here, we hypothesized that Mstn tm1Sjl/+ dams would also confer increased bone strength. In wild-type offspring, maternal myostatin deficiency altered fetal growth and calvarial collagen content of newborn mice and conferred a lasting impact on bone geometry and biomechanical integrity of offspring at 4 mo of age, the age of peak bone mass. Second, we sought to apply maternal myostatin deficiency to a mouse model with osteogenesis imperfecta (Col1a2 oim ), a heritable connective tissue disorder caused by abnormalities in the structure and/or synthesis of type I collagen. Femora of male Col1a2 oim/+ offspring from natural mating of Mstn tm1Sjl/+ dams to Col1a2 oim/+ sires had a 15% increase in torsional ultimate strength, a 29% increase in tensile strength, and a 24% increase in energy to failure compared with age, sex, and genotype-matched offspring from natural mating of Col1a2 oim/+ dams to Col1a2 oim/+ sires. Finally, increased bone biomechanical strength of Col1a2 oim/+ offspring that had been transferred into Mstn tm1Sjl/+ dams as blastocysts demonstrated that the effects of maternal myostatin deficiency were conferred by the postimplantation environment. Thus, targeting the gestational environment, and specifically prenatal myostatin pathways, provides a potential therapeutic window and an approach for treating osteogenesis imperfecta.

  15. Administration of growth hormone in selectively protein-deprived rats decreases BMD and bone strength.

    Science.gov (United States)

    Ammann, Patrick; Brennan, Tara C; Mekraldi, Samia; Aubert, Michel L; Rizzoli, René

    2010-06-01

    Isocaloric protein undernutrition is associated with decreased bone mass and decreased bone strength, together with lower IGF-I levels. It remains unclear whether administration of growth hormone (GH) corrects these alterations in bone metabolism. Six-month-old female rats were fed isocaloric diets containing either 2.5% or 15% casein for 2 weeks. Bovine growth hormone (bGH, 0.5 or 2.5mg/kg of body weight) or vehicle was then administered as subcutaneous injections, twice daily, to rats on either diet for 4 weeks. At the proximal tibia, analysis of bone mineral density (BMD), maximal load and histomorphometry were performed. In addition, urinary deoxypyridinoline, plasma osteocalcin and IGF-I concentrations were measured. Weight was monitored weekly. bGH caused a dose-dependent increase in plasma IGF-I regardless of the dietary protein content. However, bGH dose-dependently decreased BMD and bone strength in rats fed the low-protein diet. There was no significant effect of bGH on BMD in rats fed the normal protein diet within this short-term treatment period, however bone formation as detected by histomorphometry was improved in this group but not the low-protein group. Osteoclast surface was increased in the low-protein bGH-treated animals only. Changes in bone turnover markers were detectable under both normal and low-protein diets. These results emphasize the major importance of dietary protein intake in the bone response to short-term GH administration, and highlight the need for further investigation into the effects of GH treatment in patients with reduced protein intake. Copyright 2010 Elsevier Inc. All rights reserved.

  16. Nanostructured magnesium increases bone cell density.

    Science.gov (United States)

    Weng, Lucy; Webster, Thomas J

    2012-12-07

    Magnesium has attracted some attention in orthopedics due to its biodegradability and mechanical properties. Since magnesium is an essential natural mineral for bone growth, it can be expected that as a biomaterial, it would support bone formation. However, upon degradation in the body, magnesium releases OH(-) which results in an alkaline pH that can be detrimental to cell density (for example, osteoblasts or bone forming cells). For this reason, modification of magnesium may be necessary to compensate for such detrimental effects to cells. This study created biologically inspired nanoscale surface features on magnesium by soaking magnesium in various concentrations of NaOH (from 1 to 10 N) and for various periods of time (from 10 to 30 min). The results provided the first evidence of increased roughness, surface energy, and consequently greater osteoblast adhesion, after 4 h as well as density up to 7 days on magnesium treated with any concentration of NaOH for any length of time compared to untreated controls. For these reasons, this study suggests that soaking magnesium in NaOH could be an inexpensive, simple and effective manner to promote osteoblast functions for numerous orthopedic applications and, thus, should be further studied.

  17. Nanostructured magnesium increases bone cell density

    International Nuclear Information System (INIS)

    Weng, Lucy; Webster, Thomas J

    2012-01-01

    Magnesium has attracted some attention in orthopedics due to its biodegradability and mechanical properties. Since magnesium is an essential natural mineral for bone growth, it can be expected that as a biomaterial, it would support bone formation. However, upon degradation in the body, magnesium releases OH − which results in an alkaline pH that can be detrimental to cell density (for example, osteoblasts or bone forming cells). For this reason, modification of magnesium may be necessary to compensate for such detrimental effects to cells. This study created biologically inspired nanoscale surface features on magnesium by soaking magnesium in various concentrations of NaOH (from 1 to 10 N) and for various periods of time (from 10 to 30 min). The results provided the first evidence of increased roughness, surface energy, and consequently greater osteoblast adhesion, after 4 h as well as density up to 7 days on magnesium treated with any concentration of NaOH for any length of time compared to untreated controls. For these reasons, this study suggests that soaking magnesium in NaOH could be an inexpensive, simple and effective manner to promote osteoblast functions for numerous orthopedic applications and, thus, should be further studied. (paper)

  18. Effects of anti-sclerostin antibody and running on bone remodeling and strength

    Directory of Open Access Journals (Sweden)

    H. Toumi

    2015-06-01

    Full Text Available Sclerostin antibody (Scl-Ab represents a promising therapeutic approach to treat patients with osteoporosis. Purpose: The aim of this study was to investigate the effects of Scl-Ab, running and a combination of both on bone formation. Methods: Sixty female Wistar rats, aged 8 months were randomly assigned to five groups (subcutaneous injections performed twice a week: (1 (Sham: sedentary rats + saline, (2 (OVX: ovariectomized rats + saline, (3 (OVX + E: OVX rats + saline + treadmill training (5 times/week, 1 h/day, (4 (OVX + E + S: OVX rats + treadmill training + 5 mg/kg Scl-Ab and (5 (OVX + S: OVX rats + 5 mg/kg Scl-Ab. After 14 weeks, body composition, whole body and femoral BMDs were determined by DXA and serum was collected for analysis of osteocalcin and NTX. Bone microarchitecture was analyzed using μCT and bone strength was assessed at the femur mid-shaft in 3-point bending. Results: Running exercise decreased fat mass as well as the bone resorption marker NTX relative to the non-exercised control groups, effects that were associated with a prevention of the deleterious effects of OVX on whole body and femoral BMDs. Scl-Ab increased the bone formation marker osteocalcin, which resulted in robust increases in BMD and femoral metaphyseal bone volume to levels greater than in the Sham group. OVX + S + E group did not further impact on bone mass relative to the OVX + S group. At the cortical femur diaphysis, Scl-Ab prevented the decreases in bone strength after OVX, while exercise did not affect cortical strength. Conclusion: We suggest that while running on a treadmill can prevent some bone loss through a modest antiresorptive effect, it did not contribute to the robust bone-forming effects of Scl-Ab when combined in an estrogen ablation model.

  19. Reduced bone mass and muscle strength in male 5α-reductase type 1 inactivated mice.

    Directory of Open Access Journals (Sweden)

    Sara H Windahl

    Full Text Available Androgens are important regulators of bone mass but the relative importance of testosterone (T versus dihydrotestosterone (DHT for the activation of the androgen receptor (AR in bone is unknown. 5α-reductase is responsible for the irreversible conversion of T to the more potent AR activator DHT. There are two well established isoenzymes of 5α-reductase (type 1 and type 2, encoded by separate genes (Srd5a1 and Srd5a2. 5α-reductase type 2 is predominantly expressed in male reproductive tissues whereas 5α-reductase type 1 is highly expressed in liver and moderately expressed in several other tissues including bone. The aim of the present study was to investigate the role of 5α-reductase type 1 for bone mass using Srd5a1⁻/⁻ mice. Four-month-old male Srd5a1⁻/⁻ mice had reduced trabecular bone mineral density (-36%, p<0.05 and cortical bone mineral content (-15%, p<0.05 but unchanged serum androgen levels compared with wild type (WT mice. The cortical bone dimensions were reduced in the male Srd5a1⁻/⁻ mice as a result of a reduced cortical periosteal circumference compared with WT mice. T treatment increased the cortical periosteal circumference (p<0.05 in orchidectomized WT mice but not in orchidectomized Srd5a1⁻/⁻ mice. Male Srd5a1⁻/⁻ mice demonstrated a reduced forelimb muscle grip strength compared with WT mice (p<0.05. Female Srd5a1⁻/⁻ mice had slightly increased cortical bone mass associated with elevated circulating levels of androgens. In conclusion, 5α-reductase type 1 inactivated male mice have reduced bone mass and forelimb muscle grip strength and we propose that these effects are due to lack of 5α-reductase type 1 expression in bone and muscle. In contrast, the increased cortical bone mass in female Srd5a1⁻/⁻ mice, is an indirect effect mediated by elevated circulating androgen levels.

  20. A soluble activin type IIA receptor mitigates the loss of femoral neck bone strength and cancellous bone mass in a mouse model of disuse osteopenia.

    Science.gov (United States)

    Lodberg, Andreas; Eijken, Marco; van der Eerden, Bram C J; Okkels, Mette Wendelboe; Thomsen, Jesper Skovhus; Brüel, Annemarie

    2018-05-01

    Disuse causes a rapid and substantial bone loss distinct in its pathophysiology from the bone loss associated with cancers, age, and menopause. While inhibitors of the activin-receptor signaling pathway (IASPs) have been shown to prevent ovariectomy- and cancer-induced bone loss, their application in a model of disuse osteopenia remains to be tested. Here, we show that a soluble activin type IIA receptor (ActRIIA-mFc) increases diaphyseal bone strength and cancellous bone mass, and mitigates the loss of femoral neck bone strength in the Botulinum Toxin A (BTX)-model of disuse osteopenia in female C57BL/6J mice. We show that ActRIIA-mFc treatment preferentially stimulates a dual-effect (anabolic-antiresorptive) on the periosteal envelope of diaphyseal bone, demonstrating in detail the effects of ActRIIA-mFc on cortical bone. These observations constitute a previously undescribed feature of IASPs that mediates at least part of their ability to mitigate detrimental effects of unloading on bone tissue. The study findings support the application of IASPs as a strategy to combat bone loss during disuse. Copyright © 2018 Elsevier Inc. All rights reserved.

  1. Effect of Denosumab on Peripheral Compartmental Bone Density, Microarchitecture and Estimated Bone Strength in De Novo Kidney Transplant Recipients.

    Science.gov (United States)

    Bonani, Marco; Meyer, Ursina; Frey, Diana; Graf, Nicole; Bischoff-Ferrari, Heike A; Wüthrich, Rudolf P

    2016-01-01

    In a randomized controlled clinical trial in kidney transplant recipients (NCT01377467) we have recently shown that RANKL inhibition with denosumab significantly improved areal bone mineral density (aBMD) when given during the first year after transplantation. The effect of denosumab on skeletal microstructure and bone strength in kidney transplant recipients is not known. The purpose of the present bone microarchitecture ancillary study was to investigate high-resolution peripheral quantitative computed tomography (HRpQCT) data from the distal tibia and distal radius in 24 study patients that had been randomized to receive either two injections of denosumab 60 mg at baseline and after 6 months (n=10) or no treatment (n=14). Consistent with the full trial findings, denosumab reduced biomarkers of bone turnover, and significantly increased aBMD at the lumbar spine (median difference of 4.7%; 95% confidence interval [CI] 2.6 - 7.8; pBone quality as assessed by total and cortical volumetric bone mineral density (Tot. vBMD, Ct.vBMD) and cortical thickness (Ct.Th) increased significantly at the tibia, while changes at the radius were less pronounced. The trabecular volumetric BMD (Tb.vBMD), thickness (Tb. Th), separation (Tb.Sp) and number (Tb.N) and the cortical porosity (Ct.Po) at the tibia and the radius did not significantly change in both treatment groups. Micro-finite element analysis (µFEA) showed that bone stiffness increased significantly at the tibia (median difference 5.6%; 95% CI 1.8% - 9.2%; p=0.002) but not at the radius (median difference 2.9%, 95% CI -3.7% - 9.1%; p=0.369). Likewise, failure load increased significantly at the tibia (median difference 5.1%; 95% CI 2.1% - 8.1%; p=0.002) but not at the radius (median difference 2.4%, 95% CI -3.2% - 8.5%; p=0.336). These findings demonstrate that denosumab improves bone density and bone quality in first-year kidney transplant recipients at risk to develop osteoporosis. © 2016 The Author(s) Published by S

  2. Bone Mass and Strength are Significantly Improved in Mice Overexpressing Human WNT16 in Osteocytes.

    Science.gov (United States)

    Alam, Imranul; Reilly, Austin M; Alkhouli, Mohammed; Gerard-O'Riley, Rita L; Kasipathi, Charishma; Oakes, Dana K; Wright, Weston B; Acton, Dena; McQueen, Amie K; Patel, Bhavmik; Lim, Kyung-Eun; Robling, Alexander G; Econs, Michael J

    2017-04-01

    Recently, we demonstrated that osteoblast-specific overexpression of human WNT16 increased both cortical and trabecular bone mass and structure in mice. To further identify the cell-specific role of Wnt16 in bone homeostasis, we created transgenic (TG) mice overexpressing human WNT16 in osteocytes using Dmp1 promoter (Dmp1-hWNT16 TG) on C57BL/6 (B6) background. We analyzed bone phenotypes and serum bone biomarkers, performed gene expression analysis and measured dynamic bone histomorphometry in Dmp1-hWNT16 TG and wild-type (WT) mice. Compared to WT mice, Dmp1-hWNT16 TG mice exhibited significantly higher whole-body, spine and femoral aBMD, BMC and trabecular (BV/TV, Tb.N, and Tb.Th) and cortical (bone area and thickness) parameters in both male and female at 12 weeks of age. Femur stiffness and ultimate force were also significantly improved in the Dmp1-hWNT16 TG female mice, compared to sex-matched WT littermates. In addition, female Dmp1-hWNT16 TG mice displayed significantly higher MS/BS, MAR and BFR/BS compared to the WT mice. Gene expression analysis demonstrated significantly higher mRNA level of Alp in both male and female Dmp1-hWNT16 TG mice and significantly higher levels of Osteocalcin, Opg and Rankl in the male Dmp1-hWNT16 TG mice in bone tissue compared to sex-matched WT mice. These results indicate that WNT16 plays a critical role for acquisition of both cortical and trabecular bone mass and strength. Strategies designed to use WNT16 as a target for therapeutic interventions will be valuable to treat osteoporosis and other low bone mass conditions.

  3. Protein-containing nutrient supplementation following strength training enhances the effect on muscle mass, strength, and bone formation in postmenopausal women

    DEFF Research Database (Denmark)

    Holm, Lars; Olesen, Jens L; Matsumoto, Keitaro

    2008-01-01

    .0 +/- 1.4%); nutrient group: 0.953 +/- 0.051 to 0.978 +/- 0.043 g/mm(3) (3.8 +/- 3.4%)] when adjusted for age, body mass index, and BMD at inclusion. Bone formation displayed an interaction (P increased osteocalcin at 24 wk in the nutrient group. In conclusion, we report...... that nutrient supplementation results in superior improvements in muscle mass, muscle strength, femoral neck BMD, and bone formation during 24 wk of strength training. The observed differences following such a short intervention emphasize the significance of postexercise nutrient supply on musculoskeletal......We evaluated the response of various muscle and bone adaptation parameters with 24 wk of strength training in healthy, early postmenopausal women when a nutrient supplement (protein, carbohydrate, calcium, and vitamin D) or a placebo supplement (a minimum of energy) was ingested immediately...

  4. Protein-containing nutrient supplementation following strength training enhances the effect on muscle mass, strength, and bone formation in postmenopausal women

    DEFF Research Database (Denmark)

    Holm, Lars; Olesen, J.L.; Matsumoto, K.

    2008-01-01

    .4%); nutrient group: 0.953 ± 0.051 to 0.978 ± 0.043 g/mm3 (3.8 ± 3.4%)] when adjusted for age, body mass index, and BMD at inclusion. Bone formation displayed an interaction (P increased osteocalcin at 24 wk in the nutrient group. In conclusion, we report that nutrient supplementation...... results in superior improvements in muscle mass, muscle strength, femoral neck BMD, and bone formation during 24 wk of strength training. The observed differences following such a short intervention emphasize the significance of postexercise nutrient supply on musculoskeletal maintenance.......We evaluated the response of various muscle and bone adaptation parameters with 24 wk of strength training in healthy, early postmenopausal women when a nutrient supplement (protein, carbohydrate, calcium, and vitamin D) or a placebo supplement (a minimum of energy) was ingested immediately...

  5. A novel use of 3D printing model demonstrates the effects of deteriorated trabecular bone structure on bone stiffness and strength.

    Science.gov (United States)

    Barak, Meir Max; Black, Margaret Arielle

    2018-02-01

    Trabecular bone structure is crucial to normal mechanical behavior of bones. Studies have shown that osteoporosis negatively affects trabecular bone structure, mainly by reducing bone volume fraction (BV/TV) and thus increasing fracture risk. One major limitation in assessing and quantifying the effect of this structural deterioration is that no two trabecular structures are identical. Thus, when we compare a group of healthy bones against a different group of bones that experienced resorption (i.e. decreased BV/TV) we only discover an "average" mechanical effect. It is impossible to quantify the mechanical effect of individual structural deterioration for each sample, simply because we never have the same sample in both states (intact and deteriorated structure). 3D printing is a new technology that can assist in overcoming this issue. Here we report a preliminary study that compares a healthy 3D printed trabecular bone model with the same model after bone resorption was simulated. Since the deteriorated structural bone model is derived from the healthy one, it is possible to directly estimate (percentage wise) the decrease of tissue stiffness and strength as a result of bone resorption for this specific structure. Our results demonstrate that a relatively small decrease in BV/TV (about 8%) leads to a dramatic decrease in structural strength (24%) and structural stiffness (17%), (P printing is a novel and valuable tool for quantifying the effect of structural deterioration on the mechanical properties of trabecular bone. In the future, this approach may help us attain better personal fracture risk assessments by CT scanning, 3D printing and mechanically testing individual bone replicas from patients suffering excessive bone resorption. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. A grape-enriched diet increases bone calcium retention and cortical bone properties in ovariectomized rats.

    Science.gov (United States)

    Hohman, Emily E; Weaver, Connie M

    2015-02-01

    Grapes and their associated phytochemicals have been investigated for beneficial effects on cardiovascular health, cancer prevention, and other chronic diseases, but the effect of grape consumption on bone health has not been fully determined. We previously found short-term benefits of grape products on reducing bone turnover in ovariectomized rats. The objective of this study was to determine the long-term benefits of a grape-enriched diet on bone in ovariectomized rats. Rats were ovariectomized at 3 mo of age and were administered a single dose of (45)Ca to prelabel bones at 4 mo of age. After a 1-mo equilibration period, baseline urinary (45)Ca excretion was determined. Rats (n = 22/group) were then randomly assigned to a modified AIN93M diet containing 25% freeze-dried grape powder or to a control diet for 8 wk. Urinary (45)Ca excretion was monitored throughout the study to determine changes in bone (45)Ca retention. Calcium balance was assessed after 1 and 8 wk of consuming the experimental diets, and a calcium kinetic study was performed at 8 wk. After 8 wk, femurs were collected for micro-computed tomographic imaging, 3-point bending, and reference point indentation. Rats fed the grape-enriched diet had 44% greater net bone calcium retention than did rats fed the control diet. There were no differences in calcium balance due to diet at either week 1 or week 8, but there was a significant increase in net calcium absorption (10.6%) and retention (5.7%) from week 1 to week 8 in the grape-enriched diet group only. Grape-enriched diet-fed rats had 3% greater cortical thickness and 11% greater breaking strength. There were no differences in femur bone mineral density, trabecular microarchitecture, or reference point indentation variables due to diet. This study of ovariectomized rats indicates that the consumption of grape products may improve calcium utilization and suppress bone turnover, resulting in improvements in bone quality. © 2015 American Society for

  7. Physical activity, but not sedentary time, influences bone strength in late adolescence.

    Science.gov (United States)

    Tan, Vina Ps; Macdonald, Heather M; Gabel, Leigh; McKay, Heather A

    2018-03-20

    Physical activity is essential for optimal bone strength accrual, but we know little about interactions between physical activity, sedentary time, and bone outcomes in older adolescents. Physical activity (by accelerometer and self-report) positively predicted bone strength and the distal and midshaft tibia in 15-year-old boys and girls. Lean body mass mediated the relationship between physical activity and bone strength in adolescents. To examine the influence of physical activity (PA) and sedentary time on bone strength, structure, and density in older adolescents. We used peripheral quantitative computed tomography to estimate bone strength at the distal tibia (8% site; bone strength index, BSI) and tibial midshaft (50% site; polar strength strain index, SSI p ) in adolescent boys (n = 86; 15.3 ± 0.4 years) and girls (n = 106; 15.3 ± 0.4 years). Using accelerometers (GT1M, Actigraph), we measured moderate-to-vigorous PA (MVPA Accel ), vigorous PA (VPA Accel ), and sedentary time in addition to self-reported MVPA (MVPA PAQ-A ) and impact PA (ImpactPA PAQ-A ). We examined relations between PA and sedentary time and bone outcomes, adjusting for ethnicity, maturity, tibial length, and total body lean mass. At the distal tibia, MVPA Accel and VPA Accel positively predicted BSI (explained 6-7% of the variance, p accounting for lean mass. Sedentary time did not independently predict bone strength at either site. Greater tibial bone strength in active adolescents is mediated, in part, by lean mass. Despite spending most of their day in sedentary pursuits, adolescents' bone strength was not negatively influenced by sedentary time.

  8. Bone geometry, strength, and muscle size in runners with a history of stress fracture.

    Science.gov (United States)

    Popp, Kristin L; Hughes, Julie M; Smock, Amanda J; Novotny, Susan A; Stovitz, Steven D; Koehler, Scott M; Petit, Moira A

    2009-12-01

    Our primary aim was to explore differences in estimates of tibial bone strength, in female runners with and without a history of stress fractures. Our secondary aim was to explore differences in bone geometry, volumetric density, and muscle size that may explain bone strength outcomes. A total of 39 competitive distance runners aged 18-35 yr, with (SFX, n = 19) or without (NSFX, n = 20) a history of stress fracture were recruited for this cross-sectional study. Peripheral quantitative computed tomography (XCT 3000; Orthometrix, White Plains, NY) was used to assess volumetric bone mineral density (vBMD, mg x mm(-3)), bone area (ToA, mm(2)), and estimated compressive bone strength (bone strength index (BSI) = ToA x total volumetric density (ToD(2))) at the distal tibia (4%). Total (ToA, mm(2)) and cortical (CoA, mm(2)) bone area, cortical vBMD, and estimated bending strength (strength-strain index (SSIp), mm(3)) were measured at the 15%, 25%, 33%, 45%, 50%, and 66% sites. Muscle cross-sectional area (MCSA) was measured at the 50% and 66% sites. Participants in the SFX group had significantly smaller (7%-8%) CoA at the 45%, 50%, and 66% sites (P stress fracture. However, the lower strength was appropriate for the smaller muscle size, suggesting that interventions to reduce stress fracture risk might be aimed at improving muscle size and strength.

  9. A synchronous surround increases the motion strength gain of motion.

    Science.gov (United States)

    Linares, Daniel; Nishida, Shin'ya

    2013-11-12

    Coherent motion detection is greatly enhanced by the synchronous presentation of a static surround (Linares, Motoyoshi, & Nishida, 2012). To further understand this contextual enhancement, here we measured the sensitivity to discriminate motion strength for several pedestal strengths with and without a surround. We found that the surround improved discrimination of low and medium motion strengths, but did not improve or even impaired discrimination of high motion strengths. We used motion strength discriminability to estimate the perceptual response function assuming additive noise and found that the surround increased the motion strength gain, rather than the response gain. Given that eye and body movements continuously introduce transients in the retinal image, it is possible that this strength gain occurs in natural vision.

  10. Bone strength estimates relative to vertical ground reaction force discriminates women runners with stress fracture history.

    Science.gov (United States)

    Popp, Kristin L; McDermott, William; Hughes, Julie M; Baxter, Stephanie A; Stovitz, Steven D; Petit, Moira A

    2017-01-01

    To determine differences in bone geometry, estimates of bone strength, muscle size and bone strength relative to load, in women runners with and without a history of stress fracture. We recruited 32 competitive distance runners aged 18-35, with (SFX, n=16) or without (NSFX, n=16) a history of stress fracture for this case-control study. Peripheral quantitative computed tomography (pQCT) was used to assess volumetric bone mineral density (vBMD, mg/mm 3 ), total (ToA) and cortical (CtA) bone areas (mm 2 ), and estimated compressive bone strength (bone strength index; BSI, mg/mm 4 ) at the distal tibia. ToA, CtA, cortical vBMD, and estimated strength (section modulus; Zp, mm 3 and strength strain index; SSIp, mm 3 ) were measured at six cortical sites along the tibia. Mean active peak vertical (pkZ) ground reaction forces (GRFs), assessed from a fatigue run on an instrumented treadmill, were used in conjunction with pQCT measurements to estimate bone strength relative to load (mm 2 /N∗kg -1 ) at all cortical sites. SSIp and Zp were 9-11% lower in the SFX group at mid-shaft of the tibia, while ToA and vBMD did not differ between groups at any measurement site. The SFX group had 11-17% lower bone strength relative to mean pkZ GRFs (phistory of stress fracture. Bone strength relative to load is also lower in this same region suggesting that strength deficits in the middle 1/3 of the tibia and altered gait biomechanics may predispose an individual to stress fracture. Copyright © 2016. Published by Elsevier Inc.

  11. Nanoparticulate fillers improve the mechanical strength of bone cement.

    Science.gov (United States)

    Gomoll, Andreas H; Fitz, Wolfgang; Scott, Richard D; Thornhill, Thomas S; Bellare, Anuj

    2008-06-01

    Polymethylmethacrylate (PMMA-) based bone cement contains micrometer-size barium sulfate or zirconium oxide particles to radiopacify the cement for radiographic monitoring during follow-up. Considerable effort has been expended to improve the mechanical qualities of cements, largely through substitution of PMMA with new chemical structures. The introduction of these materials into clinical practice has been complicated by concerns over the unknown long-term risk profile of these new structures in vivo. We investigated a new composite with the well characterized chemical composition of current cements, but with nanoparticles instead of the conventional, micrometer-size barium sulfate radiopacifier. In this study, we replaced the barium sulfate microparticles that are usually present in commercial PMMA cements with barium sulfate nanoparticles. The resultant "microcomposite" and "nanocomposite" cements were then characterized through morphological investigations such as ultra-small angle X-ray scattering (USAXS) and scanning electron microscopy (SEM). Mechanical characterization included compression, tensile, compact tension, and fatigue testing. SEM and USAXS showed excellent dispersion of nanoparticles. Substitution of nanoparticles for microparticles resulted in a 41% increase in tensile strain-to-failure (p = 0.002) and a 70% increase in tensile work-of-fracture (p = 0.005). The nanocomposite cement also showed a two-fold increase in fatigue life compared to the conventional, microcomposite cement. In summary, nanoparticulate substitution of radiopacifiers substantially improved the in vitro mechanical properties of PMMA bone cement without changing the known chemical composition.

  12. The Effects of Annatto Tocotrienol on Bone Biomechanical Strength and Bone Calcium Content in an Animal Model of Osteoporosis Due to Testosterone Deficiency

    Directory of Open Access Journals (Sweden)

    Kok-Yong Chin

    2016-12-01

    Full Text Available Osteoporosis reduces the skeletal strength and increases the risk for fracture. It is an underdiagnosed disease in men. Annatto tocotrienol has been shown to improve bone structural indices and increase expression of bone formation genes in orchidectomized rats. This study aimed to evaluate the effects of annatto tocotrienol on biomechanical strength and calcium content of the bone in orchidectomized rats. Thirty three-month-old male Sprague-Dawley rats were randomly assigned to five groups. The baseline control (BC group was sacrificed at the onset of the study. The sham-operated group (SHAM received olive oil (the vehicle of tocotrienol orally daily and peanut oil (the vehicle of testosterone intramuscularly weekly. The remaining rats were orchidectomized and treated with three different regimens, i.e., (1 daily oral olive oil plus weekly intramuscular peanut oil injection; (2 daily oral annatto tocotrienol at 60 mg/kg plus weekly intramuscular peanut oil injection; (3 daily oral olive oil plus weekly intramuscular testosterone enanthate injection at 7 mg/kg. Blood, femur and tibia of the rats were harvested at the end of the two-month treatment period for the evaluation of serum total calcium and inorganic phosphate levels, bone biomechanical strength test and bone calcium content. Annatto-tocotrienol treatment improved serum calcium level and tibial calcium content (p < 0.05 but it did not affect femoral biomechanical strength (p > 0.05. In conclusion, annatto-tocotrienol at 60 mg/kg augments bone calcium level by preventing calcium mobilization into the circulation. A longer treatment period is needed for annatto tocotrienol to exert its effects on bone strength.

  13. Increased strength of concrete subject to high loading rates

    International Nuclear Information System (INIS)

    Curbach, M.

    1987-01-01

    Within the scope of this work various problems are discussed which occur in connection with concrete under high tensile loading rates (e.g. when a plane crashes on a nuclear power plant very high loads occur which act only for a very short time). Particularly the causes for the already frequently noticed increases in strength with increasing loading rates are investigated and also the question whether this increased strength can be taken into account when dimensioning a construction. (MM) [de

  14. 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.

  15. Elastic Resistance Effectiveness on Increasing Strength of Shoulders and Hips.

    Science.gov (United States)

    Picha, Kelsey J; Almaddah, Muataz R; Barker, Jordan; Ciochetty, Tavis; Black, W Scott; Uhl, Tim L

    2017-09-12

    Elastic resistance is a common training method used to gain strength. Currently, progression with elastic resistance is based on the perceived exertion of the exercise or completion of targeted repetitions; exact resistance is typically unknown. This study's objective is to determine if knowledge of load during elastic resistance exercise will increase strength gains during exercises. Participants were randomized into two strength training groups, elastic resistance only and elastic resistance using a load cell (LC) that displays force during exercise. The LC group used a Smart Handle (Patterson Medical Supply, Chicago, IL) to complete all exercises. Each participant completed the same exercises three times weekly for 8 weeks. The LC group was provided with a set load for exercises whereas the elastic resistance only group was not. Participant's strength was tested at baseline and program completion, measuring isometric strength for shoulder abduction (SAb), shoulder external rotation (SER), hip abduction (HAb), and hip extension (HEx). Independent t-tests were used to compare the normalized torques between groups. No significant differences were found between groups. Shoulder strength gains did not differ between groups (SAb p>0.05; SER p>0.05). Hip strength gains did not differ between groups (HAb p>0.05; HEx p>0.05). Both groups increased strength due to individual supervision, constantly evaluating degree of difficulty associated with exercise and providing feedback while using elastic resistance. Using a LC is as effective as supervised training and could provide value in a clinic setting when patients are working unsupervised.

  16. [Effect of high impact movements on body composition, strength and bone mineral density on women over 60 years].

    Science.gov (United States)

    Ramírez-Villada, Jhon F; León-Ariza, Henry H; Argüello-Gutiérrez, Yenny P; Porras-Ramírez, Keyla A

    2016-01-01

    Osteoporosis is characterised by loss of bone mass and deterioration of bone tissue microarchitecture that leads to fragility related to the risk of fractures. The aim of the study is to analyse the effects of a training program based on explosive movements and impact, assessed in a swimming pool, on body composition, explosive strength and bone mineral density in women over 60 years old. A total of 35 healthy physically active women (60±4.19 years) were divided into a training pool group using multi jumps (JG) and a control group (CG). JG trained for 24 weeks, 3 times a week, an hour and a half per session. Body composition testing, explosive strength, and bone mineral density were assessed before and after the program. There were differences in the explosive force (JG vs CG=P<.05 to .001) and the estimated power (JG vs CG=P<.05 to .002) between JG vs CG, with significant increases in JG. There were no significant differences in the percentage of fat and lean mass, bone mineral density lumbar and femoral between groups, although slightly significant increases in bone mineral density lumbar and femoral could be seen in JG after program implementation (JG pre-test vs JG post- test=P<.05). The training program with impact and explosive movements assessed in a pool induces gains in muscle strength and power with slight adaptations in body mass index in women over 60 years. Copyright © 2015 SEGG. Published by Elsevier Espana. All rights reserved.

  17. Method of making dielectric capacitors with increased dielectric breakdown strength

    Science.gov (United States)

    Ma, Beihai; Balachandran, Uthamalingam; Liu, Shanshan

    2017-05-09

    The invention is directed to a process for making a dielectric ceramic film capacitor and the ceramic dielectric laminated capacitor formed therefrom, the dielectric ceramic film capacitors having increased dielectric breakdown strength. The invention increases breakdown strength by embedding a conductive oxide layer between electrode layers within the dielectric layer of the capacitors. The conductive oxide layer redistributes and dissipates charge, thus mitigating charge concentration and micro fractures formed within the dielectric by electric fields.

  18. Bone strength and athletic ability in hominids: Ardipithecus ramidus to Homo sapiens

    Science.gov (United States)

    Lee, S. A.

    2013-03-01

    The ability of the femur to resist bending stresses is determined by its midlength cross-sectional geometry, its length and the elastic properties of the mineral part of the bone. The animal's athletic ability, determined by a ``bone strength index,'' is limited by this femoral bending strength in relation to the loads on the femur. This analysis is applied to the fossil record for Homo sapiens, Homo neanderthalensis, Homo erectus, Homo habilis, Australopithecus afarensis and Ardipithecus ramidus. Evidence that the femoral bone strength index of modern Homo sapiens has weakened over the last 50,000 years is found.

  19. Boron enhances strength and alters mineral composition of bone in rabbits fed a high energy diet.

    Science.gov (United States)

    Hakki, Sema S; Dundar, Niyazi; Kayis, Seyit Ali; Hakki, Erdogan E; Hamurcu, Mehmet; Kerimoglu, Ulku; Baspinar, Nuri; Basoglu, Abdullah; Nielsen, Forrest H

    2013-04-01

    An experiment was performed to determine whether boron had a beneficial effect on bone strength and composition in rabbits with apparent adiposity induced by a high energy diet. Sixty female New Zealand rabbits, aged 8 months, were randomly divided into five groups with the following treatments for seven months: control 1, fed alfalfa hay only (5.91 MJ/kg); control 2, high energy diet (11.76 MJ and 3.88 mg boron/kg); B10, high energy diet+10 mg/kg body weight boron gavage/96 h; B30, high energy diet+30 mg/kg body weight boron gavage/96 h; B50, high energy diet+50mg/kg body weight boron gavage/96 h. Bone boron concentrations were lowest in rabbits fed the high energy diet without boron supplementation, which suggested an inferior boron status. Femur maximum breaking force was highest in the B50 rabbits. Tibia compression strength was highest in B30 and B50 rabbits. All boron treatments significantly increased calcium and magnesium concentrations, and the B30 and B50 treatments increased the phosphorus concentration in tibia of rabbits fed the high energy diet. The B30 treatment significantly increased calcium, phosphorus and magnesium concentrations in femur of rabbits fed the high energy diet. Principal component analysis of the tibia minerals showed that the three boron treatments formed a separate cluster from controls. Discriminant analysis suggested that the concentrations of the minerals in femur could predict boron treatment. The findings indicate boron has beneficial effects on bone strength and mineral composition in rabbits fed a high energy diet. Copyright © 2012 Elsevier GmbH. All rights reserved.

  20. Microarchitecture Parameters Describe Bone Structure and Its Strength Better Than BMD

    Directory of Open Access Journals (Sweden)

    Tomasz Topoliński

    2012-01-01

    Full Text Available Introduction and Hypothesis. Some papers have shown that bone mineral density (BMD may not be accurate in predicting fracture risk. Recently microarchitecture parameters have been reported to give information on bone characteristics. The aim of this study was to find out if the values of volume, fractal dimension, and bone mineral density are correlated with bone strength. Methods. Forty-two human bone samples harvested during total hip replacement surgery were cut to cylindrical samples. The geometrical mesh of layers of bone mass obtained from microCT investigation and the volumes of each layer and fractal dimension were calculated. The finite element method was applied to calculate the compression force F causing ε=0.8% strain. Results. There were stronger correlations for microarchitecture parameters with strength than those for bone mineral density. The values of determination coefficient R2 for mean volume and force were 0.88 and 0.90 for mean fractal dimension and force, while for BMD and force the value was 0.53. The samples with bigger mean bone volume of layers and bigger mean fractal dimension of layers (more complex structure presented higher strength. Conclusion. The volumetric and fractal dimension parameters better describe bone structure and strength than BMD.

  1. 3D printing of high-strength bioscaffolds for the synergistic treatment of bone cancer

    Science.gov (United States)

    Ma, Hongshi; Li, Tao; Huan, Zhiguang; Zhang, Meng; Yang, Zezheng; Wang, Jinwu; Chang, Jiang; Wu, Chengtie

    2018-04-01

    The challenges in bone tumor therapy are how to repair the large bone defects induced by surgery and kill all possible residual tumor cells. Compared to cancellous bone defect regeneration, cortical bone defect regeneration has a higher demand for bone substitute materials. To the best of our knowledge, there are currently few bifunctional biomaterials with an ultra-high strength for both tumor therapy and cortical bone regeneration. Here, we designed Fe-CaSiO3 composite scaffolds (30CS) via 3D printing technique. First, the 30CS composite scaffolds possessed a high compressive strength that provided sufficient mechanical support in bone cortical defects; second, synergistic photothermal and ROS therapies achieved an enhanced tumor therapeutic effect in vitro and in vivo. Finally, the presence of CaSiO3 in the composite scaffolds improved the degradation performance, stimulated the proliferation and differentiation of rBMSCs, and further promoted bone formation in vivo. Such 30CS scaffolds with a high compressive strength can function as versatile and efficient biomaterials for the future regeneration of cortical bone defects and the treatment of bone cancer.

  2. Scaling in Theropod Dinosaurs: Femoral Bone Strength and Locomotion

    Science.gov (United States)

    Lee, Scott

    2015-01-01

    In our first article on scaling in theropod dinosaurs, the longitudinal stress in the leg bones due to supporting the weight of the animal was studied and found not to control the dimensions of the femur. As a continuation of our study of elasticity in dinosaur bones, we now examine the transverse stress in the femur due to locomotion and find…

  3. Simulated weightlessness and synbiotic diet effects on rat bone mechanical strength

    Science.gov (United States)

    Sarper, Hüseyin; Blanton, Cynthia; DePalma, Jude; Melnykov, Igor V.; Gabaldón, Annette M.

    2014-10-01

    This paper reports results on exposure to simulated weightlessness that leads to a rapid decrease in bone mineral density known as spaceflight osteopenia by evaluating the effectiveness of dietary supplementation with synbiotics to counteract the effects of skeletal unloading. Forty adult male rats were studied under four different conditions in a 2 × 2 factorial design with main effects of diet (synbiotic and control) and weight condition (unloaded and control). Hindlimb unloading was performed at all times for 14 days followed by 14 days of recovery (reambulation). The synbiotic diet contained probiotic strains Lactobacillus acidophilus and Lactococcus lactis lactis and prebiotic fructooligosaccharide. This paper also reports on the development of a desktop three-point bending device to measure the mechanical strength of bones from rats subjected to simulated weightlessness. The importance of quantifying bone resistance to breakage is critical when examining the effectiveness of interventions against osteopenia resulting from skeletal unloading, such as astronauts experience, disuse or disease. Mechanical strength indices provide information beyond measures of bone density and microarchitecture that enhance the overall assessment of a treatment's potency. In this study we used a newly constructed three-point bending device to measure the mechanical strength of femur and tibia bones from hindlimb-unloaded rats fed an experimental synbiotic diet enriched with probiotics and fermentable fiber. Two calculated outputs for each sample were Young's modulus of elasticity and fracture stress. Bone major elements (calcium, magnesium, and phosphorous) were quantified using ICP-MS analysis. Hindlimb unloading was associated with a significant loss of strength in the femur, and with significant reductions in major bone elements. The synbiotic diet did not protect against these unloading effects. Tibia strength and major elements were not reduced by hindlimb unloading, as was

  4. Bone material strength index as measured by impact microindentation is altered in patients with acromegaly.

    Science.gov (United States)

    Malgo, F; Hamdy, N A T; Rabelink, T J; Kroon, H M; Claessen, K M J A; Pereira, A M; Biermasz, N R; Appelman-Dijkstra, N M

    2017-03-01

    Acromegaly is a rare disease caused by excess growth hormone (GH) production by the pituitary adenoma. The skeletal complications of GH and IGF-1 excess include increased bone turnover, increased cortical bone mass and deteriorated microarchitecture of trabecular bone, associated with a high risk of vertebral fractures in the presence of relatively normal bone mineral density (BMD). We aimed to evaluate tissue-level properties of bone using impact microindentation (IMI) in well-controlled patients with acromegaly aged ≥18 years compared to 44 controls from the outpatient clinic of the Centre for Bone Quality. In this cross-sectional study, bone material strength index (BMSi) was measured in 48 acromegaly patients and 44 controls with impact microindentation using the osteoprobe. Mean age of acromegaly patients (54% male) was 60.2 years (range 37.9-76.5), and 60.5 years (range 39.8-78.6) in controls (50% male). Patients with acromegaly and control patients had comparable BMI (28.2 kg/m 2  ± 4.7 vs 26.6 kg/m 2  ± 4.3, P = 0.087) and comparable BMD at the lumbar spine (1.04 g/cm 2  ± 0.21 vs 1.03 g/cm 2  ± 0.13, P = 0.850) and at the femoral neck (0.84 g/cm 2  ± 0.16 vs 0.80 g/cm 2  ± 0.09, P = 0.246). BMSi was significantly lower in acromegaly patients than that in controls (79.4 ± 0.7 vs 83.2 ± 0.7; P acromegaly after reversal of long-term exposure to pathologically high GH and IGF-1 levels. Our findings also suggest that methods other than DXA should be considered to evaluate bone fragility in patients with acromegaly. © 2017 European Society of Endocrinology.

  5. At-home resistance tubing strength training increases shoulder strength in the trained and untrained limb.

    Science.gov (United States)

    Magnus, C R A; Boychuk, K; Kim, S Y; Farthing, J P

    2014-06-01

    The purpose was to determine if an at-home resistance tubing strength training program on one shoulder (that is commonly used in rehabilitation settings) would produce increases in strength in the trained and untrained shoulders via cross-education. Twenty-three participants were randomized to TRAIN (strength-trained one shoulder; n = 13) or CONTROL (no intervention; n = 10). Strength training was completed at home using resistance tubing and consisted of maximal shoulder external rotation, internal rotation, scaption, retraction, and flexion 3 days/week for 4 weeks. Strength was measured via handheld dynamometry and muscle size measured via ultrasound. For external rotation strength, the trained (10.9 ± 10.9%) and untrained (12.7 ± 9.6%) arm of TRAIN was significantly different than CONTROL (1.6 ± 13.2%; -2.7 ± 12.3%; pooled across arm; P tubing training program on one limb can produce increases in strength in both limbs, and has implications for rehabilitation after unilateral shoulder injuries. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  6. Strength through structure: visualization and local assessment of the trabecular bone structure

    International Nuclear Information System (INIS)

    Raeth, C; Monetti, R; Bauer, J; Sidorenko, I; Mueller, D; Matsuura, M; Lochmueller, E-M; Zysset, P; Eckstein, F

    2008-01-01

    The visualization and subsequent assessment of the inner human bone structures play an important role for better understanding the disease- or drug-induced changes of bone in the context of osteoporosis giving prospect for better predictions of bone strength and thus of the fracture risk of osteoporotic patients. In this work, we show how the complex trabecular bone structure can be visualized using μCT imaging techniques at an isotropic resolution of 26 μm. We quantify these structures by calculating global and local topological and morphological measures, namely Minkowski functionals (MFs) and utilizing the (an-)isotropic scaling index method (SIM) and by deriving suitable texture measures based on MF and SIM. Using a sample of 151 specimens taken from human vertebrae in vitro, we correlate the texture measures with the mechanically measured maximum compressive strength (MCS), which quantifies the strength of the bone probe, by using Pearson's correlation coefficient. The structure parameters derived from the local measures yield good correlations with the bone strength as measured in mechanical tests. We investigate whether the performance of the texture measures depends on the MCS value by selecting different subsamples according to MCS. Considering the whole sample the results for the newly defined parameters are better than those obtained for the standard global histomorphometric parameters except for bone volume/total volume (BV/TV). If a subsample consisting only of weak bones is analysed, the local structural analysis leads to similar and even better correlations with MCS as compared to BV/TV. Thus, the MF and SIM yield additional information about the stability of the bone especially in the case of weak bones, which corroborates the hypothesis that the bone structure (and not only its mineral mass) constitutes an important component of bone stability.

  7. Bone metabolism and hand grip strength response to aerobic versus ...

    African Journals Online (AJOL)

    porosis is incomplete and has prompted our interest to identify the type of effective osteogenic exercise. ... between aerobic and resistance exercise training in non-insulin dependent ... paired glucose metabolism on bone health as well as to.

  8. Relationships of muscle strength and bone mineral density in ambulatory children with cerebral palsy.

    Science.gov (United States)

    Chen, C-L; Lin, K-C; Wu, C-Y; Ke, J-Y; Wang, C-J; Chen, C-Y

    2012-02-01

    This work explores the relationships of muscle strength and areal bone mineral density (aBMD) in ambulatory children with cerebral palsy (CP). The knee extensor strength, but not motor function, was related to aBMD. Thus, muscle strength, especially antigravity muscle strength, was more associated with aBMD in these children than motor function. Muscle strength is related to bone density in normal children. However, no studies have examined these relationships in ambulatory children with CP. This work explores the relationships of muscle strength and aBMD in ambulatory children with CP. Forty-eight ambulatory children with spastic CP, aged 5-15 years, were classified into two groups based on Gross Motor Function Classification System levels: I (n = 28) and II (n = 20). Another 31 normal development (ND) children were recruited as the comparison group for the aBMD. Children with CP underwent assessments of growth, lumbar and distal femur aBMD, Gross Motor Function Measure-66 (GMFM-66), and muscle strength of knee extensor and flexor by isokinetic dynamometer. The distal femur aBMD, but not lumbar aBMD, was lower in children with CP than in ND children (p antigravity muscle strength, were more associated with the bone density of ambulatory children with CP than motor function. The data may allow clinicians for early identifying the ambulatory CP children of potential low bone density.

  9. Does increased local bone resorption secondary to breast and prostate cancer result in increased cartilage degradation?

    DEFF Research Database (Denmark)

    Leeming, Diana J; Byrjalsen, Inger; Qvist, Per

    2008-01-01

    BACKGROUND: Breast and prostate cancer patients often develop lesions of locally high bone turnover, when the primary tumor metastasizes to the bone causing an abnormal high bone resorption at this site. The objective of the present study was to determine whether local increased bone turnover in ...... experiments revealed that osteoclasts released CTXI fragments but not CTXII from bone specimens. The same was observed for cathepsin K. CONCLUSION: Data suggest that an uncoupling between bone resorption and cartilage degradation occurs in breast and lung cancer patient....

  10. Food restriction causes low bone strength and microarchitectural deterioration in exercised growing male rats.

    Science.gov (United States)

    Hattori, Satoshi; Park, Jong-Hoon; Agata, Umon; Oda, Masaya; Higano, Michito; Aikawa, Yuki; Akimoto, Takayuki; Nabekura, Yoshiharu; Yamato, Hideyuki; Ezawa, Ikuko; Omi, Naomi

    2014-01-01

    The pathogenesis of bone disorders in young male athletes has not been well understood. We hypothesized that bone fragility is caused by low energy availability, due to insufficient food intake and excessive exercise energy expenditure in young male athletes. To examine this hypothesis, we investigated the influence of food restriction on bone strength and bone morphology in exercised growing male rats, using three-point bending test, dual-energy X-ray absormetry, and micro-computed tomography. Four-week-old male Sprague-Dawley rats were divided randomly into the following groups: the control (Con) group, exercise (Ex) group, food restriction (R) group, and food restriction plus exercise (REx) group after a 1-wk acclimatization period. Thirty-percent food restriction in the R and REx groups was carried out in comparison with that in the Con group. Voluntary running exercise was performed in the Ex and REx groups. The experimental period lasted 13 wk. At the endpoint of this experiment, the bone strength of the femurs and tibial BMD in the REx group were significantly lower than those in the Con group. Moreover, trabecular bone volume and cortical bone volume in the REx group were also significantly lower than those in the Con group. These findings indicate that food restriction causes low bone strength and microarchitectural deterioration in exercised growing male rats.

  11. Increasing Lean Mass and Strength: A Comparison of High Frequency Strength Training to Lower Frequency Strength Training.

    Science.gov (United States)

    Thomas, Michael H; Burns, Steve P

    The purpose of this study was to determine the effect strength training frequency has on improvements in lean mass and strength. Participants were 7 women and 12 men, age ( χ̄ = 34.64 years ± 6.91 years), with strength training experience, training age ( χ̄ = 51.16 months ± 39.02 months). Participants were assigned to one of two groups to equal baseline group demographics. High frequency training group (HFT) trained each muscle group as the agonist, 3 times per week, exercising with 3 sets per muscle group per session (3 total body workouts). Low frequency training group (LFT) trained each muscle group as the agonist one time per week, completing all 9 sets during that one workout. LFT consisted of a routine split over three days: 1) pectoralis, deltoids, and triceps; 2) upper back and biceps; 3) quadriceps, hamstrings, calves, and abdominals. Following eight weeks of training, HFT increased lean mass by 1.06 kg ± 1.78 kg, (1.9%), and LFT increased lean mass by .99 kg ± 1.31 kg, (2.0%). HFT strength improvements on the chest press was 9.07 kg ± 6.33 kg, (11%), and hack squat 20.16 kg ± 11.59 kg, (21%). LFT strength improvements on chest press was 5.80kg ± 4.26 kg, (7.0%), and hack squat 21.83 kg ± 11.17 kg, (24 %). No mean differences between groups were significant. These results suggest that HFT and LFT of equal set totals result in similar improvements in lean mass and strength, following 8 weeks of strength training.

  12. Sterilisation of allograft cortical bone using gamma irradiation: effect on strength and material ultrastructure

    International Nuclear Information System (INIS)

    Price, R.; Walters, M.

    1996-01-01

    Full text: The use of allograft bone in revision joint and limb salvage surgery is widespread and increasing (Buck B.E. et al, Clin Orthop 303: 8-17, 1994). To reduce the risk of disease transmission from donor graft contamination (particularly HIV and hepatitis) sterilisation is practiced worldwide. Gamma (γ)-irradiation using a dose of 1.5 - 2.5 Mrads is common. However, γ-irradiation is known to reduce bone strength, though the extent and mechanisms are controversial (eg Bright RW et al, Trans Orthop Res Soc 3: 210, 1978). We measured the effect of γ-irradiation on bone strength and properties reflecting bone material ultrastructure. Diaphyseal bone was obtained from the femur of a 47 year-old male would-be donor with suspicious hepatitis serology. Beams of cortical bone (long axes parallel to the femur) were cut using a low speed diamond saw bathed in Ringer's solution. Four groups were irradiated with γ-rays (0, 1.5, 2.5 and 5.0±0.5[SD] Mrads). Blinded investigations were performed: Ultimate stress (Ult Stress, N= 16 replicates in each dose group). Each beam was loaded at its midpoint at a rate of 25 mm/min until failure, while its ends were supported 40 mms apart. Ult stress was calculated from 3-point bending theory using the load vs displacement curve and the cross-sectional area of the break (Power RA et al, submitted to J Bone and Joint Surg). Differential scanning calorimetry (DSC) was performed over the range -15 to +5 deg C. Samples were demineralized and small (7-10 mg) blocks were cut and sealed in stainless steel calorimetry capsules. The enthalpy (reflecting the normalised free water content) was calculated from the sample mass plus area under the heat capacity curve. Pyridinoline collagen (acid-insoluble) crosslinks (Pyrid, N=10) (Randall D et al, JBone and Min Res, 1996, in press) were determined from 5-mm 3 demineralised, freeze dried samples. Small and medium angle X-ray diffraction (XRD, N=5). Demineralised bone was sliced into thin

  13. Association of neck strength with upper femoral geometry and bone mineral density in postmenopausal women

    Directory of Open Access Journals (Sweden)

    Monika Gupta

    2016-01-01

    Full Text Available Background: Hip fracture is a severe health burden in the elderly population. In order to prevent, it is to evaluate the bone strength by establishing the relation between bone mineral density (BMD, neck strength, and geometry. Materials and Methods: The subjects under study were 100 postmenopausal women who visited bone clinic of Bharat Scan Centre. After recording general profile such as age, body mass index (BMI, geometric measures such as hip axis length (HAL, neck shaft angle (NSA, and neck width (NW were measured from digital X-ray. For the same individuals, BMD was measured using dual energy X-ray absorptiometry (DXA scan. From the DXA print out neck strength was calculated using the formula = sectional modulus/HAL. Results: The correlation test was analyzed among BMD, neck strength, anthropometric, and geometric factors using Statistical packages for social services (SPSS software. BMD is inversely related with age and positively correlated with height, weight, and BMI. HAL, NSA, and NW had a weaker association with BMD. Age, BMD, and NSA had a negative relation with neck strength. HAL and NW had a positive relation with neck strength. Conclusion: Noninvasive means of associating neck strength with BMD and geometry will provide improved estimates for fracture risk beyond any other invasive method of assessing bone mineral properties.

  14. Objectively measured physical activity and bone strength in 9-year-old boys and girls.

    Science.gov (United States)

    Sardinha, Luís B; Baptista, Fátima; Ekelund, Ulf

    2008-09-01

    The purpose of this work was to analyze the relationship between intensity and duration of physical activity and composite indices of femoral neck strength and bone-mineral content of the femoral neck, lumbar spine, and total body. Physical activity was assessed by accelerometry in 143 girls and 150 boys (mean age: 9.7 years). Measurement of bone-mineral content, femoral neck bone-mineral density, femoral neck width, hip axis length, and total body fat-free mass was performed with dual-energy radiograph absorptiometry. Compressive [(bone-mineral density x femoral neck width/weight)] and bending strength [(bone-mineral density x femoral neck width(2))/(hip axis length x weight)] express the forces that the femoral neck has to withstand in weight bearing, whereas impact strength [(bone-mineral density x femoral neck width x hip axis length)/(height x weight)] expresses the energy that the femoral neck has to absorb in an impact from standing height. Analysis of covariance (fat-free mass and age adjusted) showed differences between boys and girls of approximately 9% for compressive, 10% for bending, and 9% for impact strength. Stepwise regression analysis using time spent at sedentary, light, moderate, and vigorous physical activity as predictors revealed that vigorous physical activity explained 5% to 9% of femoral neck strength variable variance in both genders, except for bending strength in boys, and approximately 1% to 3% of total body and femoral neck bone-mineral content variance. Vigorous physical activity was then used to categorize boys and girls into quartiles. Pairwise comparison indicated that boys in the third and fourth quartiles (accumulation of >26 minutes/day) demonstrated higher compressive (11%-12%), bending (10%), and impact (14%) strength than boys in the first quartile. In girls, comparison revealed a difference between the fourth (accumulation of >25 minutes/day) and first quartiles for bending strength (11%). We did not observe any

  15. Articular Cartilage Increases Transition Zone Regeneration in Bone-tendon Junction Healing

    Science.gov (United States)

    Qin, Ling; Lee, Kwong Man; Leung, Kwok Sui

    2008-01-01

    The fibrocartilage transition zone in the direct bone-tendon junction reduces stress concentration and protects the junction from failure. Unfortunately, bone-tendon junctions often heal without fibrocartilage transition zone regeneration. We hypothesized articular cartilage grafts could increase fibrocartilage transition zone regeneration. Using a goat partial patellectomy repair model, autologous articular cartilage was harvested from the excised distal third patella and interposed between the residual proximal two-thirds bone fragment and tendon during repair in 36 knees. We evaluated fibrocartilage transition zone regeneration, bone formation, and mechanical strength after repair at 6, 12, and 24 weeks and compared them with direct repair. Autologous articular cartilage interposition resulted in more fibrocartilage transition zone regeneration (69.10% ± 14.11% [mean ± standard deviation] versus 8.67% ± 7.01% at 24 weeks) than direct repair at all times. There was no difference in the amount of bone formation and mechanical strength achieved. Autologous articular cartilage interposition increases fibrocartilage transition zone regeneration in bone-tendon junction healing, but additional research is required to ascertain the mechanism of stimulation and to establish the clinical applicability. PMID:18987921

  16. Bone strength and muscle properties in postmenopausal women with and without a recent distal radius fracture.

    Science.gov (United States)

    Crockett, K; Arnold, C M; Farthing, J P; Chilibeck, P D; Johnston, J D; Bath, B; Baxter-Jones, A D G; Kontulainen, S A

    2015-10-01

    Distal radius (wrist) fracture (DRF) in women over age 50 years is an early sign of bone fragility. Women with a recent DRF compared to women without DRF demonstrated lower bone strength, muscle density, and strength, but no difference in dual-energy x-ray absorptiometry (DXA) measures, suggesting DXA alone may not be a sufficient predictor for DRF risk. The objective of this study was to investigate differences in bone and muscle properties between women with and without a recent DRF. One hundred sixty-six postmenopausal women (50-78 years) were recruited. Participants were excluded if they had taken bone-altering medications in the past 6 months or had medical conditions that severely affected daily living or the upper extremity. Seventy-seven age-matched women with a fracture in the past 6-24 months (Fx, n = 32) and without fracture (NFx, n = 45) were measured for bone and muscle properties using the nondominant (NFx) or non-fractured limb (Fx). Peripheral quantitative computed tomography (pQCT) was used to estimate bone strength in compression (BSIc) at the distal radius and tibia, bone strength in torsion (SSIp) at the shaft sites, muscle density, and area at the forearm and lower leg. Areal bone mineral density at the ultradistal forearm, spine, and femoral neck was measured by DXA. Grip strength and the 30-s chair stand test were used as estimates of upper and lower extremity muscle strength. Limb-specific between-group differences were compared using multivariate analysis of variance (MANOVA). There was a significant group difference (p lower leg, with the Fx group demonstrating 16 and 19% lower BSIc, 3 and 6% lower muscle density, and 20 and 21% lower muscle strength at the upper and lower extremities, respectively. There were no differences between groups for DXA measures. Women with recent DRF had lower pQCT-derived estimated bone strength at the distal radius and tibia and lower muscle density and strength at both extremities.

  17. Effects of casein, whey and soy proteins on volumetric bone density and bone strength in immunocompromised piglets

    DEFF Research Database (Denmark)

    Budek, Alicja Zofia; Bjørnvad, Charlotte; Mølgaard, Christian

    2007-01-01

    Summary:Background and aims: Bone-promoting effect of different proteins in early life, under immunocompromised conditions, is unknown. We investigated effects of milk- and plantderived proteins on bone development in immunocompromised piglets. Methods: Newborn, colostrum-deprived piglets were...... assigned to a formula based on either casein (n=11), whey (n=11) or soy (n=10) as the protein source (each 55 g/L), and equal amounts of fat, carbohydrates, calcium and phosphorus. Results & Conclusion: Despite efforts to sustain immuno-protection (sow serum and antibiotic injections), some piglets became...... sick and were early euthanised. After 6 days, bone density (peripheral quantitative computed tomography), bone mechanical strength (three-point bending test) and serum insulin-like growth factor-I (sIGF-I) (immunoassay) were measured in the surviving piglets (casein n=5, whey n=9, soy n=5)....

  18. Alterations of bone microstructure and strength in end-stage renal failure.

    Science.gov (United States)

    Trombetti, A; Stoermann, C; Chevalley, T; Van Rietbergen, B; Herrmann, F R; Martin, P-Y; Rizzoli, R

    2013-05-01

    End-stage renal disease (ESRD) patients have a high risk of fractures. We evaluated bone microstructure and finite-element analysis-estimated strength and stiffness in patients with ESRD by high-resolution peripheral computed tomography. We observed an alteration of cortical and trabecular bone microstructure and of bone strength and stiffness in ESRD patients. Fragility fractures are common in ESRD patients on dialysis. Alterations of bone microstructure contribute to skeletal fragility, independently of areal bone mineral density. We compared microstructure and finite-element analysis estimates of strength and stiffness by high-resolution peripheral quantitative computed tomography (HR-pQCT) in 33 ESRD patients on dialysis (17 females and 16 males; mean age, 47.0 ± 12.6 years) and 33 age-matched healthy controls. Dialyzed women had lower radius and tibia cortical density with higher radius cortical porosity and lower tibia cortical thickness, compared to controls. Radius trabecular number was lower with higher heterogeneity of the trabecular network. Male patients displayed only a lower radius cortical density. Radius and tibia cortical thickness correlated negatively with bone-specific alkaline phosphatase (BALP). Microstructure did not correlate with parathyroid hormone (PTH) levels. Cortical porosity correlated positively with "Kidney Disease: Improving Global Outcomes" working group PTH level categories (r = 0.36, p microstructure and calculated bone strength are altered in ESRD patients, predominantly in women. Bone microstructure and biomechanical assessment by HR-pQCT may be of major clinical relevance in the evaluation of bone fragility in ESRD patients.

  19. Microscopic analysis of bone microstructures with increasing age in ...

    African Journals Online (AJOL)

    Microscopic analysis of bone microstructures with increasing age in Malaysian females. ... Journal of Fundamental and Applied Sciences ... death from skeletal remains is one of the main physical aspect in reconstruction demographic profiles.

  20. Foam concrete of increased strength with the thermomodified peat additives

    Science.gov (United States)

    Kudyakov, A. I.; Kopanitsa, N. O.; Sarkisov, Ju S.; Kasatkina, A. V.; Prischepa, I. A.

    2015-01-01

    The paper presents the results of research of foam concrete with thermomodified peat additives. The aim of the research was to study the effect of modifying additives on cement stone and foam concrete properties. Peat additives are prepared by heat treatment of peat at 600 °C. Two approaches of obtaining additives are examined: in condition of open air access (TMT-600) and in condition of limited air access (TMT-600-k). Compressive strength of a cement stone with modifiers found to be increased by 28.9 - 65.2%. Introducing peat modifiers into foam concrete mix leads to increase of compressive strength by 44-57% at 28- day age and heat conductivity of foam concrete decreases by 0.089 W/(m·°C).

  1. Increased bone marrow blood flow in polycythemia vera

    International Nuclear Information System (INIS)

    Lathinen, R.; Lathinen, T.; Hyoedynmaa, S.

    1983-01-01

    Bone marrow blood flow was measured in polycythemia vera, in compensatory and in relative polycythemia with a 133 Xe washout method. In the treated polycythemia vera bone marrow blood flow was significantly increased compared with the age-matched controls. The fraction of blood flow entering the bone and flowing through the hematopoietic marrow was markedly increased in both the untreated and the treated polycythemia vera. Although the number of observations in compensatory and relative polycythemia was small, the results suggest that bone marrow blood flow is not markedly increased in these diseases. The results also suggest that in older patients the simple 133 Xe method may support the diagnosis of polycythemia vera. (orig.)

  2. Increased bone marrow blood flow in polycythemia vera

    Energy Technology Data Exchange (ETDEWEB)

    Lathinen, R.; Lathinen, T.; Hyoedynmaa, S.

    1983-01-01

    Bone marrow blood flow was measured in polycythemia vera, in compensatory and in relative polycythemia with a /sup 133/Xe washout method. In the treated polycythemia vera bone marrow blood flow was significantly increased compared with the age-matched controls. The fraction of blood flow entering the bone and flowing through the hematopoietic marrow was markedly increased in both the untreated and the treated polycythemia vera. Although the number of observations in compensatory and relative polycythemia was small, the results suggest that bone marrow blood flow is not markedly increased in these diseases. The results also suggest that in older patients the simple /sup 133/Xe method may support the diagnosis of polycythemia vera.

  3. Hand grip strength and maximum peak expiratory flow: determinants of bone mineral density of adolescent students.

    Science.gov (United States)

    Cossio-Bolaños, Marco; Lee-Andruske, Cynthia; de Arruda, Miguel; Luarte-Rocha, Cristian; Almonacid-Fierro, Alejandro; Gómez-Campos, Rossana

    2018-03-02

    Maintaining and building healthy bones during the lifetime requires a complicated interaction between a number of physiological and lifestyle factors. Our goal of this study was to analyze the association between hand grip strength and the maximum peak expiratory flow with bone mineral density and content in adolescent students. The research team studied 1427 adolescent students of both sexes (750 males and 677 females) between the ages of 11.0 and 18.9 years in the Maule Region of Talca (Chile). Weight, standing height, sitting height, hand grip strength (HGS), and maximum peak expiratory flow (PEF) were measured. Furthermore, bone mineral density (BMD) and total body bone mineral content (BMC) were determined by using the Dual-Energy X-Ray Absorptiometry (DXA). Hand grip strength and PEF were categorized in tertiles (lowest, middle, and highest). Linear regression was performed in steps to analyze the relationship between the variables. Differences between categories were determined through ANOVA. In males, the hand grip strength explained 18-19% of the BMD and 20-23% of the BMC. For the females, the percentage of variation occurred between 12 and 13% of the BMD and 17-18% of the BMC. The variation of PEF for the males was observed as 33% of the BMD and 36% of the BMC. For the females, both the BMD and BMC showed a variation of 19%. The HGS and PEF were divided into three categories (lowest, middle, and highest). In both cases, significant differences occurred in bone density health between the three categories. In conclusion, the HGS and the PEF related positively to the bone density health of both sexes of adolescent students. The adolescents with poor values for hand grip strength and expiratory flow showed reduced values of BMD and BMC for the total body. Furthermore, the PEF had a greater influence on bone density health with respect to the HGS of the adolescents of both sexes.

  4. Trabecular bone structure and strength - remodelling and repair

    DEFF Research Database (Denmark)

    Mosekilde, Lis; Ebbesen, Ebbe Nils; Erikstrup, Lise Tornvig

    2000-01-01

    vertical and horizontal struts reaching a certain magnitude and thereby inducing buckling under compression. 4) Microdamage and microfractures will occur - mainly in these very loaded vertical struts. The microfractures will be repaired by microcallus formation, and these calluses will later be removed...... can never be isolated in vivo, other factors need to be investigated: The interplay between the cortical shell and the trabecular network; transmission of load; the interplay between soft tissues (cartilage, connective tissue, muscle) and bone; the shock absorbing capacity of the discs...

  5. Myostatin (GDF-8) Deficiency Increases Fracture Callus Size, Sox-5 Expression, and Callus Bone Volume

    OpenAIRE

    Kellum, Ethan; Starr, Harlan; Arounleut, Phonepasong; Immel, David; Fulzele, Sadanand; Wenger, Karl; Hamrick, Mark W.

    2008-01-01

    Myostatin (GDF-8) is a negative regulator of skeletal muscle growth and mice lacking myostatin show increased muscle mass. We have previously shown that myostatin deficiency increases bone strength and biomineralization throughout the skeleton, and others have demonstrated that myostatin is expressed during the earliest phase of fracture repair. In order to determine the role of myostatin in fracture callus morphogenesis, we studied fracture healing in mice lacking myostatin. Adult wild-type ...

  6. Improvement of the compressive strength of a cuttlefish bone-derived porous hydroxyapatite scaffold via polycaprolactone coating.

    Science.gov (United States)

    Kim, Beom-Su; Kang, Hyo Jin; Lee, Jun

    2013-10-01

    Cuttlefish bones (CBs) have emerged as attractive biomaterials because of their porous structure and components that can be converted into hydroxyapatite (HAp) via a hydrothermal reaction. However, their brittleness and low strength restrict their application in bone tissue engineering. Therefore, to improve the compressive strength of the scaffold following hydrothermal conversion to a HAp form of CB (CB-HAp), the scaffold was coated using a polycaprolactone (PCL) polymer at various concentrations. In this study, raw CB was successfully converted into HAp via a hydrothermal reaction. We then evaluated their surface properties and composition by scanning electron microscopy and X-ray diffraction analysis. The CB-HAp coated with PCL showed improved compressive performance and retained a microporous structure. The compressive strength was significantly increased upon coating with 5 and 10% PCL, by 2.09- and 3.30-fold, respectively, as compared with uncoated CB-HAp. However, coating with 10% PCL resulted in a reduction in porosity. Furthermore, an in vitro biological evaluation demonstrated that MG-63 cells adhered well, proliferated and were able to be differentiated on the PCL-coated CB-HAp scaffold, which was noncytotoxic. These results suggest that a simple coating method is useful to improve the compressive strength of CB-HAp for bone tissue engineering applications. Copyright © 2013 Wiley Periodicals, Inc.

  7. Nanostructural hierarchy increases the strength of aluminium alloys.

    Science.gov (United States)

    Liddicoat, Peter V; Liao, Xiao-Zhou; Zhao, Yonghao; Zhu, Yuntian; Murashkin, Maxim Y; Lavernia, Enrique J; Valiev, Ruslan Z; Ringer, Simon P

    2010-09-07

    Increasing the strength of metallic alloys while maintaining formability is an interesting challenge for enabling new generations of lightweight structures and technologies. In this paper, we engineer aluminium alloys to contain a hierarchy of nanostructures and possess mechanical properties that expand known performance boundaries-an aerospace-grade 7075 alloy exhibits a yield strength and uniform elongation approaching 1 GPa and 5%, respectively. The nanostructural architecture was observed using novel high-resolution microscopy techniques and comprises a solid solution, free of precipitation, featuring (i) a high density of dislocations, (ii) subnanometre intragranular solute clusters, (iii) two geometries of nanometre-scale intergranular solute structures and (iv) grain sizes tens of nanometres in diameter. Our results demonstrate that this novel architecture offers a design pathway towards a new generation of super-strong materials with new regimes of property-performance space.

  8. Osteoinductive potential of demineralized rat bone increases with increasing donor age from birth to adulthood

    DEFF Research Database (Denmark)

    Pinholt, E M; Solheim, E

    1998-01-01

    Demineralized allogenic bone implanted in the subcutis or muscle of rodents causes formation of heterotopic bone by osteoinduction. The osteoinductive response may be weaker in primates than in rodents. It was suggested that the osteoinductive response of demineralized bone for clinical use could...... be enhanced by using young donors, because studies have indicated that the osteoinductive response is reduced in demineralized bone of old versus young donors. However, these findings may not represent a gradual decline in the osteoinductive property of bone matrix throughout the life span. We evaluated...... quantitatively, by uptake of strontium 85, the osteoinductive effect of demineralized bone matrix from newborn, 8-week-old (adolescent), and 8-month-old (adult) male Wistar rats implanted in the abdominal muscles of 8-week-old male Wistar rats. The osteoinductive response increased significantly with increasing...

  9. Influence of fall related factors and bone strength on fracture risk in the frail elderly.

    Science.gov (United States)

    Sambrook, P N; Cameron, I D; Chen, J S; Cumming, R G; Lord, S R; March, L M; Schwarz, J; Seibel, M J; Simpson, J M

    2007-05-01

    When subjects are selected on the basis of fall risk alone, therapies for osteoporosis have not been effective. In a prospective study of elderly subjects at high risk of falls, we investigated the influence of bone strength and fall risk on fracture. At baseline we assessed calcaneal bone ultrasound attenuation (BUA) as well as quantitative measures of fall risk in 2005 subjects in residential care. Incident falls and fractures were recorded (median follow-up 705 days). A total of 6646 fall events and 375 low trauma fracture events occurred. The fall rate was 214 per 100 person years and the fracture rate 12.1 per 100 person years. 82% of the fractures could be attributed to falls. Although fracture rates increased with decreasing BUA (incidence rate ratio 1.94 for lowest vs. highest BUA tertile, pfalls also affected fracture incidence. Subjects who fell frequently (>3.15 falls/per person year) were 3.35 times more likely to suffer a fracture than those who did not fall. Some fall risk factors such as balance were associated with the lowest fracture risk lowest in the worst performing group. Multivariate analysis revealed higher fall rate, history of previous fracture, lower BUA, lower body weight, cognitive impairment and better balance as significant independent risk factors for fracture. In the frail elderly, both skeletal fragility and fall risk including the frequency of exposure to falls are important determinants of fracture risk.

  10. Alterations of bone microstructure and strength in end-stage renal failure

    NARCIS (Netherlands)

    Trombetti, A.; Stoermann, C.; Chevalley, T.; Rietbergen, van B.; Hermann, F.R.; Martin, P.Y.; Rizzoli, R.

    2013-01-01

    Summary End-stage renal disease (ESRD) patients have a high risk of fractures. We evaluated bone microstructure and finite-element analysis-estimated strength and stiffness in patients with ESRD by high-resolution peripheral computed tomography. We observed an alteration of cortical and trabecular

  11. In vitro comparison of DE-QCT parameters with the compressive strength of cancellous bone

    International Nuclear Information System (INIS)

    Oravez, W.T.; Robertson, D.D.

    1986-01-01

    Quantitative computed tomography (QCT) is used as a method for assessing bone mineral in patients with osteoporosis. The implication being that if the mass of bone mineral is low enough then the patient is at risk for developing symptoms, i.e., fracture. The authors performed an in vitro test which compared dual-energy-QCT (DE-QCT) parameters with compressive strength. The bone samples were placed in a water bath and CT scanned using a Siemens DR-3. Alternating x-ray pulses of 125 and 85 kVp were used to generate the dual energy images. Four images, high kVp, low kVp, monoenergenic, and calcium equivalent, were reconstructed from each scan. A specially constructed bone mineral calibration phantom, consisting of a polyethylene rod and varying tubes of K2HP04, was placed within the water bath along with the specimens. Comparisons will be made between the various DE parameters and their relationship to the compressive strength of cancellous bone. The critical effect of trabecular bone orientation will also be discussed

  12. Muscle strength and areal bone mineral density at the hip in women: a cross-sectional study.

    Science.gov (United States)

    Pasco, Julie A; Holloway, Kara L; Brennan-Olsen, Sharon L; Moloney, David J; Kotowicz, Mark A

    2015-05-24

    Muscle strengthening exercises are promoted for building and maintaining a healthy skeleton. We aimed to investigate the relationship between muscle strength and areal bone mineral density (BMD) at the hip in women aged 26-97 years. This cross-sectional study utilises data from 863 women assessed for the Geelong Osteoporosis Study. Measures of hip flexor and abductor strength were made using a hand-held dynamometer (Nicholas Manual Muscle Tester). The maximal measure from three trials on each leg was used for analyses. BMD was measured at the hip using dual energy x-ray absorptiometry (DXA; Lunar DPX-L). Total lean mass, body fat mass and appendicular lean mass were determined from whole body DXA scans. Linear regression techniques were used with muscle strength as the independent variable and BMD as the dependent variable. Models were adjusted for age and indices of body composition. Measures of age-adjusted hip flexor strength and hip abductor strength were positively associated with total hip BMD. For each standard deviation (SD) increase in hip flexor strength, the increase in mean total hip BMD (SD) was 10.4 % (p = 0.009). A similar pattern was observed for hip abductor strength, with an increase in mean total hip BMD of 22.8 % (p = 0.025). All associations between hip muscle strength and total hip BMD were independent of height, but were nullified after adjusting for appendicular lean mass or total lean mass. There was a positive association observed between muscle strength and BMD at the hip. However, this association was explained by measures of lean mass.

  13. Are bone turnover markers associated with volumetric bone density, size, and strength in older men and women? The AGES-Reykjavik study.

    Science.gov (United States)

    Marques, E A; Gudnason, V; Sigurdsson, G; Lang, T; Johannesdottir, F; Siggeirsdottir, K; Launer, L; Eiriksdottir, G; Harris, T B

    2016-05-01

    Association between serum bone formation and resorption markers and bone mineral, structural, and strength variables derived from quantitative computed tomography (QCT) in a population-based cohort of 1745 older adults was assessed. The association was weak for lumbar spine and femoral neck areal and volumetric bone mineral density. The aim of this study was to examine the relationship between levels of bone turnover markers (BTMs; osteocalcin (OC), C-terminal cross-linking telopeptide of type I collagen (CTX), and procollagen type 1N propeptide (P1NP)) and quantitative computed tomography (QCT)-derived bone density, geometry, and strength indices in the lumbar spine and femoral neck (FN). A total of 1745 older individuals (773 men and 972 women, aged 66-92 years) from the Age, Gene/Environment Susceptibility (AGES)-Reykjavik cohort were studied. QCT was performed in the lumbar spine and hip to estimate volumetric trabecular, cortical, and integral bone mineral density (BMD), areal BMD, bone geometry, and bone strength indices. Association between BTMs and QCT variables were explored using multivariable linear regression. Major findings showed that all BMD measures, FN cortical index, and compressive strength had a low negative correlation with the BTM levels in both men and women. Correlations between BTMs and bone size parameters were minimal or not significant. No associations were found between BTMs and vertebral cross-sectional area in women. BTMs alone accounted for only a relatively small percentage of the bone parameter variance (1-10 %). Serum CTX, OC, and P1NP were weakly correlated with lumbar spine and FN areal and volumetric BMD and strength measures. Most of the bone size indices were not associated with BTMs; thus, the selected bone remodeling markers do not reflect periosteal bone formation. These results confirmed the limited ability of the most sensitive established BTMs to predict bone structural integrity in older adults.

  14. NGF blockade at early times during bone cancer development attenuates bone destruction and increases limb use.

    Science.gov (United States)

    McCaffrey, Gwen; Thompson, Michelle L; Majuta, Lisa; Fealk, Michelle N; Chartier, Stephane; Longo, Geraldine; Mantyh, Patrick W

    2014-12-01

    Studies in animals and humans show that blockade of nerve growth factor (NGF) attenuates both malignant and nonmalignant skeletal pain. While reduction of pain is important, a largely unanswered question is what other benefits NGF blockade might confer in patients with bone cancer. Using a mouse graft model of bone sarcoma, we demonstrate that early treatment with an NGF antibody reduced tumor-induced bone destruction, delayed time to bone fracture, and increased the use of the tumor-bearing limb. Consistent with animal studies in osteoarthritis and head and neck cancer, early blockade of NGF reduced weight loss in mice with bone sarcoma. In terms of the extent and time course of pain relief, NGF blockade also reduced pain 40% to 70%, depending on the metric assessed. Importantly, this analgesic effect was maintained even in animals with late-stage disease. Our results suggest that NGF blockade immediately upon detection of tumor metastasis to bone may help preserve the integrity and use, delay the time to tumor-induced bone fracture, and maintain body weight. ©2014 American Association for Cancer Research.

  15. Evaluation of methods for increasing vacuum breakdown strength

    International Nuclear Information System (INIS)

    Evans, R.D.; Cooke, C.M.; Berman, E.R.

    1977-01-01

    Research to determine the effectiveness of coated and gas shielded cathodes as a means of increasing vacuum breakdown strength under short pulse conditions is reported. A technique for rapidly evaluating large numbers of coatings on small electrodes at relatively low pulse voltage (120 kV or less) and methods for testing larger electrodes and fewer coatings at higher total voltage were developed. Experiments with gas shielded cathodes were also conducted. Results suggest that it may be possible to eliminate prebreakdown current and to double breakdown strength by applying a suitable coating to the cathode. Breakdown stresses in excess of 2 MV/cm were obtained in a 0.5 mm gap with sputtered coatings of alumina, Cr 2 O 3 , and several readily available epoxies. Electrodes two orders of magnitude greater in area were tested, and stresses approaching 1 MV/cm were measured in 5 mm gaps for several epoxies and for alumina. It has further been shown that, because similar trends occurred in the data from large and small experiments, it should be possible to screen potential coatings rapidly and effectively with minimum expenditure using a method similar to that employed for small electrodes at low pulse voltage

  16. Concentric resistance training increases muscle strength without affecting microcirculation

    Energy Technology Data Exchange (ETDEWEB)

    Weber, Marc-Andre [Department of Diagnostic and Interventional Radiology, University of Heidelberg, Heidelberg (Germany)], E-mail: MarcAndre.Weber@med.uni-heidelberg.de; Hildebrandt, Wulf [Immunochemistry, German Cancer Research Center (dkfz), Heidelberg (Germany); Schroeder, Leif [Medical Physics in Radiology, German Cancer Research Center (dkfz), Heidelberg (Germany); Kinscherf, Ralf [Department of Anatomy and Developmental Biology, University of Heidelberg, Heidelberg (Germany); Krix, Martin [Radiology, German Cancer Research Center (dkfz), Heidelberg (Germany); Bachert, Peter [Medical Physics in Radiology, German Cancer Research Center (dkfz), Heidelberg (Germany); Delorme, Stefan; Essig, Marco [Radiology, German Cancer Research Center (dkfz), Heidelberg (Germany); Kauczor, Hans-Ulrich [Department of Diagnostic and Interventional Radiology, University of Heidelberg, Heidelberg (Germany); Krakowski-Roosen, Holger [National Center for Tumor Diseases (NCT), Heidelberg (Germany)

    2010-03-15

    Purpose: While the evidence is conclusive regarding the positive effects of endurance training, there is still some controversy regarding the effects of resistance training on muscular capillarity. Thus, the purpose was to assess whether resistance strength training influences resting skeletal muscle microcirculation in vivo. Materials and methods: Thirty-nine middle-aged subjects (15 female, 24 male; mean age, 54 {+-} 9 years) were trained twice a week on an isokinetic system (altogether 16 sessions lasting 50 min, intensity 75% of maximum isokinetic and isometric force of knee flexors and extensors). To evaluate success of training, cross-sectional area (CSA) of the quadriceps femoris muscle and its isokinetic and isometric force were quantified. Muscular capillarization was measured in biopsies of the vastus lateralis muscle. In vivo, muscular energy and lipid metabolites were quantified by magnetic resonance spectroscopy and parameters of muscular microcirculation, such as local blood volume, blood flow and velocity, by contrast-enhanced ultrasound analyzing replenishment kinetics. Results: The significant (P < 0.001) increase in CSA (60 {+-} 16 before vs. 64 {+-} 15 cm{sup 2} after training) and in absolute muscle strength (isometric, 146 {+-} 44 vs. 174 {+-} 50 Nm; isokinetic, 151 {+-} 53 vs. 174 {+-} 62 Nm) demonstrated successful training. Neither capillary density ex vivo (351 {+-} 75 vs. 326 {+-} 62) nor ultrasonographic parameters of resting muscle perfusion were significantly different (blood flow, 1.2 {+-} 1.2 vs. 1.1 {+-} 1.1 ml/min/100 g; blood flow velocity, 0.49 {+-} 0.44 vs. 0.52 {+-} 0.74 mm s{sup -1}). Also, the intensities of high-energy phosphates phosphocreatine and {beta}-adenosintriphosphate were not different after training within the skeletal muscle at rest ({beta}-ATP/phosphocreatine, 0.29 {+-} 0.06 vs. 0.28 {+-} 0.04). Conclusion: The significant increase in muscle size and strength in response to concentric isokinetic and isometric

  17. Relative contributions of lean and fat mass to bone strength in young Hispanic and non-Hispanic girls.

    Science.gov (United States)

    Hetherington-Rauth, Megan; Bea, Jennifer W; Blew, Robert M; Funk, Janet L; Hingle, Melanie D; Lee, Vinson R; Roe, Denise J; Wheeler, Mark D; Lohman, Timothy G; Going, Scott B

    2018-05-22

    With the high prevalence of childhood obesity, especially among Hispanic children, understanding how body weight and its components of lean and fat mass affect bone development is important, given that the amount of bone mineral accrued during childhood can determine osteoporosis risk later in life. The aim of this study was to assess the independent contributions of lean and fat mass on volumetric bone mineral density (vBMD), geometry, and strength in both weight-bearing and non-weight-bearing bones of Hispanic and non-Hispanic girls. Bone vBMD, geometry, and strength were assessed at the 20% distal femur, the 4% and 66% distal tibia, and the 66% distal radius of the non-dominant limb of 326, 9- to 12-year-old girls using peripheral quantitative computed tomography (pQCT). Total body lean and fat mass were measured by dual-energy x-ray absorptiometry (DXA). Multiple linear regression was used to assess the independent relationships of fat and lean mass with pQCT bone measures while adjusting for relevant confounders. Potential interactions between ethnicity and both fat and lean mass were also tested. Lean mass was a significant positive contributor to all bone outcomes (p Lean mass is the main determinant of bone strength for appendicular skeletal sites. Fat mass contributes to bone strength in the weight-bearing skeleton but does not add to bone strength in non-weight-bearing locations and may potentially be detrimental. Bone vBMD, geometry, and strength did not differ between Hispanic and non-Hispanic girls; fat mass may be a stronger contributor to bone strength in weight-bearing bones of Hispanic girls compared to non-Hispanic. Copyright © 2018. Published by Elsevier Inc.

  18. Enhanced Wnt signaling improves bone mass and strength, but not brittleness, in the Col1a1(+/mov13) mouse model of type I Osteogenesis Imperfecta.

    Science.gov (United States)

    Jacobsen, Christina M; Schwartz, Marissa A; Roberts, Heather J; Lim, Kyung-Eun; Spevak, Lyudmila; Boskey, Adele L; Zurakowski, David; Robling, Alexander G; Warman, Matthew L

    2016-09-01

    Osteogenesis Imperfecta (OI) comprises a group of genetic skeletal fragility disorders. The mildest form of OI, Osteogenesis Imperfecta type I, is frequently caused by haploinsufficiency mutations in COL1A1, the gene encoding the α1(I) chain of type 1 collagen. Children with OI type I have a 95-fold higher fracture rate compared to unaffected children. Therapies for OI type I in the pediatric population are limited to anti-catabolic agents. In adults with osteoporosis, anabolic therapies that enhance Wnt signaling in bone improve bone mass, and ongoing clinical trials are determining if these therapies also reduce fracture risk. We performed a proof-of-principle experiment in mice to determine whether enhancing Wnt signaling in bone could benefit children with OI type I. We crossed a mouse model of OI type I (Col1a1(+/Mov13)) with a high bone mass (HBM) mouse (Lrp5(+/p.A214V)) that has increased bone strength from enhanced Wnt signaling. Offspring that inherited the OI and HBM alleles had higher bone mass and strength than mice that inherited the OI allele alone. However, OI+HBM and OI mice still had bones with lower ductility compared to wild-type mice. We conclude that enhancing Wnt signaling does not make OI bone normal, but does improve bone properties that could reduce fracture risk. Therefore, agents that enhance Wnt signaling are likely to benefit children and adults with OI type 1. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. Concentric resistance training increases muscle strength without affecting microcirculation

    International Nuclear Information System (INIS)

    Weber, Marc-Andre; Hildebrandt, Wulf; Schroeder, Leif; Kinscherf, Ralf; Krix, Martin; Bachert, Peter; Delorme, Stefan; Essig, Marco; Kauczor, Hans-Ulrich; Krakowski-Roosen, Holger

    2010-01-01

    Purpose: While the evidence is conclusive regarding the positive effects of endurance training, there is still some controversy regarding the effects of resistance training on muscular capillarity. Thus, the purpose was to assess whether resistance strength training influences resting skeletal muscle microcirculation in vivo. Materials and methods: Thirty-nine middle-aged subjects (15 female, 24 male; mean age, 54 ± 9 years) were trained twice a week on an isokinetic system (altogether 16 sessions lasting 50 min, intensity 75% of maximum isokinetic and isometric force of knee flexors and extensors). To evaluate success of training, cross-sectional area (CSA) of the quadriceps femoris muscle and its isokinetic and isometric force were quantified. Muscular capillarization was measured in biopsies of the vastus lateralis muscle. In vivo, muscular energy and lipid metabolites were quantified by magnetic resonance spectroscopy and parameters of muscular microcirculation, such as local blood volume, blood flow and velocity, by contrast-enhanced ultrasound analyzing replenishment kinetics. Results: The significant (P 2 after training) and in absolute muscle strength (isometric, 146 ± 44 vs. 174 ± 50 Nm; isokinetic, 151 ± 53 vs. 174 ± 62 Nm) demonstrated successful training. Neither capillary density ex vivo (351 ± 75 vs. 326 ± 62) nor ultrasonographic parameters of resting muscle perfusion were significantly different (blood flow, 1.2 ± 1.2 vs. 1.1 ± 1.1 ml/min/100 g; blood flow velocity, 0.49 ± 0.44 vs. 0.52 ± 0.74 mm s -1 ). Also, the intensities of high-energy phosphates phosphocreatine and β-adenosintriphosphate were not different after training within the skeletal muscle at rest (β-ATP/phosphocreatine, 0.29 ± 0.06 vs. 0.28 ± 0.04). Conclusion: The significant increase in muscle size and strength in response to concentric isokinetic and isometric resistance training occurs without an increase in the in vivo microcirculation of the skeletal muscles at

  20. Muscular strength measurements indicate bone mineral density loss in postmenopausal women

    Directory of Open Access Journals (Sweden)

    Zhou Z

    2013-10-01

    Full Text Available Zhixiong Zhou,1,2 Lu Zheng,3 Dengyun Wei,4 Ming Ye,3 Xun Li2 1School of Physical Education and Coaching Science, Capital University of Physical Education and Sports, Beijing, People’s Republic of China; 2Graduate School, Beijing Sport University, Beijing, People’s Republic of China; 3School of Kinesiology and Health Education, Capital University of Physical Education and Sports, Beijing, People’s Republic of China; 4Department of Physical Education, Anhui Normal University, Anhui, People’s Republic of China Background: The literature is inconsistent and inconclusive on the relationship between bone mineral density (BMD and muscular strength in postmenopausal women. Objective: To evaluate the relationship between isokinetically and isometrically determined muscle strength and BMD in postmenopausal women of different age groups. Methods: Healthy postmenopausal women (n = 293; mean age, 54.22 ± 3.85 years were enrolled in this study. They were grouped by age according to World Health Organization life expectancy: 45–50 years, 51–53 years, 54–56 years, 57–59 years, and 60–64 years. Total BMD, L2–4 BMD, and femoral neck BMD were measured by dual-energy X-ray bone densitometry; isokinetic and isometric muscle strength of the right hip and trunk muscles were measured during contractile exercise. Stepwise regression analysis was used to examine the relationships between BMD and strength measures, controlling for subject age and years since menopause. Results: Results of stepwise regression showed that hip extensor and flexor strength at 120°/second and back extend strength at 30°/second accounted for 26% total BMD variance among menopausal subjects, 19% L2–4 BMD variance, and 15% femoral neck BMD variance; in postmenopausal women of different age groups, hip extensor and flexor strength at 120°/second and back extend strength at 30°/second accounted for 25%–35% total BMD variance. Conclusion: Different optimal strength

  1. Adult bone strength of children from single-parent families: the Midlife in the United States Study.

    Science.gov (United States)

    Crandall, C J; Karlamangla, A S; Merkin, S S; Binkley, N; Carr, D; Greendale, G A; Seeman, T E

    2015-03-01

    Bone health may be negatively impacted by childhood socio-environmental circumstances. We examined the independent associations of single-parent childhood and parental death or divorce in childhood with adult bone strength indices. Longer exposure to a single-parent household in childhood was associated with lower bone strength in adulthood. Because peak bone mass is acquired during childhood, bone health may be negatively impacted by childhood socio-environmental disadvantage. The goal of this study was to determine whether being raised in a single-parent household is associated with lower bone strength in adulthood. Using dual-energy X-ray absorptiometry data from 708 participants (mean age 57 years) in the Midlife in the United States Biomarker Project, we examined the independent associations of composite indices of femoral neck bone strength relative to load (in three failure modes: compression, bending, and impact) in adulthood with the experience of single-parent childhood and parental death or divorce in childhood. After adjustment for gender, race, menopause transition stage, age, and body mass index, each additional year of single-parent childhood was associated with 0.02 to 0.03 SD lower indices of adult femoral neck strength. In those with 9-16 years of single-parent childhood, the compression strength index was 0.41 SD lower, bending strength index was 0.31 SD lower, and impact strength index was 0.25 SD lower (all p values divorce during childhood was not by itself independently associated with adult bone strength indices. The magnitudes of these associations were unaltered by additional adjustment for lifestyle factors and socioeconomic status in childhood and adulthood. Independent of parental death or divorce, growing up in a single-parent household is associated with lower femoral neck bone strength in adulthood, and this association is not entirely explained by childhood or adult socioeconomic conditions or lifestyle choices.

  2. The effect of feeding different sugar-sweetened beverages to growing female Sprague-Dawley rats on bone mass and strength.

    Science.gov (United States)

    Tsanzi, Embedzayi; Light, Heather R; Tou, Janet C

    2008-05-01

    Consumption of sugar beverages has increased among adolescents. Additionally, the replacement of sucrose with high fructose corn syrup (HFCS) as the predominant sweetener has resulted in higher fructose intake. Few studies have investigated the effect of drinking different sugar-sweetened beverages on bone, despite suggestions that sugar consumption negatively impacts mineral balance. The objective of this study was to determine the effect of drinking different sugar-sweetened beverages on bone mass and strength. Adolescent (age 35d) female Sprague-Dawley rats were randomly assigned (n=8-9/group) to consume deionized distilled water (ddH2O, control) or ddH2O containing 13% w/v glucose, sucrose, fructose or high fructose corn syrup (HFCS-55) for 8weeks. Tibia and femur measurements included bone morphometry, bone turnover markers, determination of bone mineral density (BMD) and bone mineral content (BMC) by dual energy X-ray absorptiometry (DXA) and bone strength by three-point bending test. The effect of sugar-sweetened beverage consumption on mineral balance, urinary and fecal calcium (Ca) and phosphorus (P) was measured by inductively coupled plasma optical emission spectrometry. The results showed no difference in the bone mass or strength of rats drinking the glucose-sweetened beverage despite their having the lowest food intake, but the highest beverage and caloric consumption. Only in comparisons among the rats provided sugar-sweetened beverage were femur and tibia BMD lower in rats drinking the glucose-sweetened beverage. Differences in bone and mineral measurements appeared most pronounced between rats drinking glucose versus fructose-sweetened beverages. Rats provided the glucose-sweetened beverage had reduced femur and tibia total P, reduced P and Ca intake and increased urinary Ca excretion compared to the rats provided the fructose-sweetened beverage. The results suggested that glucose rather than fructose exerted more deleterious effects on mineral

  3. High strength, biodegradable and cytocompatible alpha tricalcium phosphate-iron composites for temporal reduction of bone fractures.

    Science.gov (United States)

    Montufar, E B; Casas-Luna, M; Horynová, M; Tkachenko, S; Fohlerová, Z; Diaz-de-la-Torre, S; Dvořák, K; Čelko, L; Kaiser, J

    2018-04-01

    In this work alpha tricalcium phosphate (α-TCP)/iron (Fe) composites were developed as a new family of biodegradable, load-bearing and cytocompatible materials. The composites with composition from pure ceramic to pure metallic samples were consolidated by pulsed electric current assisted sintering to minimise processing time and temperature while improving their mechanical performance. The mechanical strength of the composites was increased and controlled with the Fe content, passing from brittle to ductile failure. In particular, the addition of 25 vol% of Fe produced a ceramic matrix composite with elastic modulus much closer to cortical bone than that of titanium or biodegradable magnesium alloys and specific compressive strength above that of stainless steel, chromium-cobalt alloys and pure titanium, currently used in clinic for internal fracture fixation. All the composites studied exhibited higher degradation rate than their individual components, presenting values around 200 μm/year, but also their compressive strength did not show a significant reduction in the period required for bone fracture consolidation. Composites showed preferential degradation of α-TCP areas rather than β-TCP areas, suggesting that α-TCP can produce composites with higher degradation rate. The composites were cytocompatible both in indirect and direct contact with bone cells. Osteoblast-like cells attached and spread on the surface of the composites, presenting proliferation rate similar to cells on tissue culture-grade polystyrene and they showed alkaline phosphatase activity. Therefore, this new family of composites is a potential alternative to produce implants for temporal reduction of bone fractures. Biodegradable alpha-tricalcium phosphate/iron (α-TCP/Fe) composites are promising candidates for the fabrication of temporal osteosynthesis devices. Similar to biodegradable metals, these composites can avoid implant removal after bone fracture healing, particularly in

  4. Adhesive strength of bone-implant interfaces and in-vivo degradation of PHB composites for load-bearing applications.

    Science.gov (United States)

    Meischel, M; Eichler, J; Martinelli, E; Karr, U; Weigel, J; Schmöller, G; Tschegg, E K; Fischerauer, S; Weinberg, A M; Stanzl-Tschegg, S E

    2016-01-01

    Aim of this study was to evaluate the response of bone to novel biodegradable polymeric composite implants in the femora of growing rats. Longitudinal observation of bone reaction at the implant site (BV/TV) as well as resorption of the implanted pins were monitored using in vivo micro-focus computed tomography (µCT). After 12, 24 and 36 weeks femora containing the implants were explanted, scanned with high resolution ex vivo µCT, and the surface roughness of the implants was measured to conclude on the ingrowth capability for bone tissue. Scanning electron microscope (SEM) and energy dispersive X-ray spectroscopy (EDX) were used to observe changes on the surface of Polyhydroxybutyrate (PHB) during degradation and cell ingrowth. Four different composites with zirconium dioxide (ZrO2) and Herafill(®) were compared. After 36 weeks in vivo, none of the implants did show significant degradation. The PHB composite with ZrO2 and a high percentage (30%) of Herafill® as well as the Mg-alloy WZ21 showed the highest values of bone accumulation (increased BV/TV) around the implant. The lowest value was measured in PHB with 3% ZrO2 containing no Herafill®. Roughness measurements as well as EDX and SEM imaging could not reveal any changes on the PHB composites׳ surfaces. Biomechanical parameters, such as the adhesion strength between bone and implant were determined by measuring the shear strength as well as push-out energy of the bone-implant interface. The results showed that improvement of these mechanical properties of the studied PHBs P3Z, P3Z10H and P3Z30H is necessary in order to obtain appropriate load-bearing material. The moduli of elasticity, tensile strength and strain properties of the PHB composites are close to that of bone and thus promising. Compared to clinically used PLGA, PGA and PLA materials, their additional benefit is an unchanged local pH value during degradation, which makes them well tolerated by cells and immune system. They might be used

  5. Skeletal muscle fat content is inversely associated with bone strength in young girls.

    Science.gov (United States)

    Farr, Joshua N; Funk, Janet L; Chen, Zhao; Lisse, Jeffrey R; Blew, Robert M; Lee, Vinson R; Laudermilk, Monica; Lohman, Timothy G; Going, Scott B

    2011-09-01

    Childhood obesity is an established risk factor for metabolic disease. The influence of obesity on bone development, however, remains controversial and may depend on the pattern of regional fat deposition. Therefore, we examined the associations of regional fat compartments of the calf and thigh with weight-bearing bone parameters in girls. Data from 444 girls aged 9 to 12 years from the Jump-In: Building Better Bones study were analyzed. Peripheral quantitative computed tomography (pQCT) was used to assess bone parameters at metaphyseal and diaphyseal sites of the femur and tibia along with subcutaneous adipose tissue (SAT, mm(2) ) and muscle density (mg/cm(3) ), an index of skeletal muscle fat content. As expected, SAT was positively correlated with total-body fat mass (r = 0.87-0.89, p  .05), except the distal tibia (β = 0.09, p = .03). In conclusion, skeletal muscle fat content of the calf and thigh is inversely associated with weight-bearing bone strength in young girls. Copyright © 2011 American Society for Bone and Mineral Research.

  6. BONE STRENGTH (ossis tibiae OF NATIVE PIGS ZŁOTNICKA SPOTTED BREED AND CROSSBREDS OF POLISH LARGE WHITE AND PoLISH LANDRACE PIGS

    Directory of Open Access Journals (Sweden)

    Wojciech KAPELAŃSKI

    2012-01-01

    Full Text Available The purpose of this study was to compare the bone strength traits in two groups of pigs different in terms of genetic value, fast growth capability and meat deposition in the body. The study covered 33 fatteners of the Złotnicka Spotted breed (ZŁP and 20 crossbreds F1 (Polish Large White x Polish Landrace. Tibial bones were obtained following slaughter and evaluated in terms of properties and geometry, as well as bending and compressive strength. Mineral composition of the bone tissue was also established, i.e.: ash, Ca, P, Na, K, Zn and Mg. The significance of differences between the traits demonstrated by pigs in both groups subject to the study was estimated, with calculated overall correlations between the primary bone properties. The results confirmed significant differences in terms of geometry of the bones in both animal groups. In the ZŁP breed pigs, compared to the F1 crossbred group (PLW x PL, the outside and inside diameters of the tibial shaft were smaller (P ≤ 0.01, yet the average thickness of the wall of the bone was slightly larger. The bending force required to fracture the bone turned out to be lower in Złotnicka Spotted pigs, the opposite of the results obtained with regard to the compressive strength. Furthermore, calcium content, calcium-phosphorus ratio (Ca : P and sodium content were highly statistically or significantly larger in the bone tissue of the Złotnicka Spotted pigs. Consequently, the final results show that the bone strength demonstrated by modern pig breeds subject to intensive selection focused on high growth rate and increased meat deposition is in no way lower than the same trait recognized in the Złotnicka Spotted breed kept in preservative breeding conditions.

  7. Reduced diaphyseal strength associated with high intracortical vascular porosity within long bones of children with osteogenesis imperfecta.

    Science.gov (United States)

    Albert, Carolyne; Jameson, John; Smith, Peter; Harris, Gerald

    2014-09-01

    Osteogenesis imperfecta is a genetic disorder resulting in bone fragility. The mechanisms behind this fragility are not well understood. In addition to characteristic bone mass deficiencies, research suggests that bone material properties are compromised in individuals with this disorder. However, little data exists regarding bone properties beyond the microstructural scale in individuals with this disorder. Specimens were obtained from long bone diaphyses of nine children with osteogenesis imperfecta during routine osteotomy procedures. Small rectangular beams, oriented longitudinally and transversely to the diaphyseal axis, were machined from these specimens and elastic modulus, yield strength, and maximum strength were measured in three-point bending. Intracortical vascular porosity, bone volume fraction, osteocyte lacuna density, and volumetric tissue mineral density were determined by synchrotron micro-computed tomography, and relationships among these mechanical properties and structural parameters were explored. Modulus and strength were on average 64-68% lower in the transverse vs. longitudinal beams (Posteogenesis imperfecta. Results confirm that these properties are anisotropic. Elevated vascular porosity was observed in most specimens, and this parameter was associated with reduced bone material strength. These results offer insight toward understanding bone fragility and the role of intracortical porosity on the strength of bone tissue in children with osteogenesis imperfecta. Copyright © 2014 Elsevier Inc. All rights reserved.

  8. Relationship between bone strength and dual-energy X-ray absorptiometry measurements in pigs

    DEFF Research Database (Denmark)

    Nielsen, Dorte Hald; McEvoy, Fintan; Madsen, M.T.

    2007-01-01

    BMD (1.4 g/cm2, respectively). The results showed a difference in the maximum load, in the stress at maximum load, and stiffness among each BMD group (P ... and extrinsic measures of bone strength and BMD was thus demonstrated. The projected change in each of the variables reported, for a 0.1 /cm2 alteration in BMD (within the BMD range evaluated in this study), is as follows: maximum load, 708 N; stress at maximum load, 50 N/mm2; stiffness, 391.6 N/mm; and elastic...... modulus, 108 N/mm2 (P relationship between BMD and bone strength and indicate that BMD screening can be used in fracture risk assessments in production pigs....

  9. Injectable porous nano-hydroxyapatite/chitosan/tripolyphosphate scaffolds with improved compressive strength for bone regeneration

    Energy Technology Data Exchange (ETDEWEB)

    Uswatta, Suren P.; Okeke, Israel U. [Department of Bioengineering, The University of Toledo, Toledo, OH 43614 (United States); Jayasuriya, Ambalangodage C., E-mail: a.jayasuriya@utoledo.edu [Department of Bioengineering, The University of Toledo, Toledo, OH 43614 (United States); Department of Orthopaedic Surgery, The University of Toledo, Toledo, OH 43614 (United States)

    2016-12-01

    In this study we have fabricated porous injectable spherical scaffolds using chitosan biopolymer, sodium tripolyphosphate (TPP) and nano-hydroxyapatite (nHA). TPP was primarily used as an ionic crosslinker to crosslink nHA/chitosan droplets. We hypothesized that incorporating nHA into chitosan could support osteoconduction by emulating the mineralized cortical bone structure, and improve the Ultimate Compressive Strength (UCS) of the scaffolds. We prepared chitosan solutions with 0.5%, 1% and 2% (w/v) nHA concentration and used simple coacervation and lyophilization techniques to obtain spherical scaffolds. Lyophilized spherical scaffolds had a mean diameter of 1.33 mm (n = 25). Further, portion from each group lyophilized scaffolds were soaked and dried to obtain Lyophilized Soaked and Dried (LSD) scaffolds. LSD scaffolds had a mean diameter of 0.93 mm (n = 25) which is promising property for the injectability. Scanning Electron Microscopy images showed porous surface morphology and interconnected pore structures inside the scaffolds. Lyophilized and LSD scaffolds had surface pores < 10 and 2 μm, respectively. 2% nHA/chitosan LSD scaffolds exhibited UCS of 8.59 MPa compared to UCS of 2% nHA/chitosan lyophilized scaffolds at 3.93 MPa. Standardize UCS values were 79.98 MPa and 357 MPa for 2% nHA/chitosan lyophilized and LSD particles respectively. One-way ANOVA results showed a significant increase (p < 0.001) in UCS of 1% and 2% nHA/chitosan lyophilized scaffolds compared to 0% and 0.5% nHA/chitosan lyophilized scaffolds. Moreover, 2% nHA LSD scaffolds had significantly increased (p < 0.005) their mean UCS by 120% compared to 2% nHA lyophilized scaffolds. In a drawback, all scaffolds have lost their mechanical properties by 95% on the 2nd day when fully immersed in phosphate buffered saline. Additionally live and dead cell assay showed no cytotoxicity and excellent osteoblast attachment to both lyophilized and LSD scaffolds at the end of 14th day of in vitro

  10. Injectable porous nano-hydroxyapatite/chitosan/tripolyphosphate scaffolds with improved compressive strength for bone regeneration

    International Nuclear Information System (INIS)

    Uswatta, Suren P.; Okeke, Israel U.; Jayasuriya, Ambalangodage C.

    2016-01-01

    In this study we have fabricated porous injectable spherical scaffolds using chitosan biopolymer, sodium tripolyphosphate (TPP) and nano-hydroxyapatite (nHA). TPP was primarily used as an ionic crosslinker to crosslink nHA/chitosan droplets. We hypothesized that incorporating nHA into chitosan could support osteoconduction by emulating the mineralized cortical bone structure, and improve the Ultimate Compressive Strength (UCS) of the scaffolds. We prepared chitosan solutions with 0.5%, 1% and 2% (w/v) nHA concentration and used simple coacervation and lyophilization techniques to obtain spherical scaffolds. Lyophilized spherical scaffolds had a mean diameter of 1.33 mm (n = 25). Further, portion from each group lyophilized scaffolds were soaked and dried to obtain Lyophilized Soaked and Dried (LSD) scaffolds. LSD scaffolds had a mean diameter of 0.93 mm (n = 25) which is promising property for the injectability. Scanning Electron Microscopy images showed porous surface morphology and interconnected pore structures inside the scaffolds. Lyophilized and LSD scaffolds had surface pores < 10 and 2 μm, respectively. 2% nHA/chitosan LSD scaffolds exhibited UCS of 8.59 MPa compared to UCS of 2% nHA/chitosan lyophilized scaffolds at 3.93 MPa. Standardize UCS values were 79.98 MPa and 357 MPa for 2% nHA/chitosan lyophilized and LSD particles respectively. One-way ANOVA results showed a significant increase (p < 0.001) in UCS of 1% and 2% nHA/chitosan lyophilized scaffolds compared to 0% and 0.5% nHA/chitosan lyophilized scaffolds. Moreover, 2% nHA LSD scaffolds had significantly increased (p < 0.005) their mean UCS by 120% compared to 2% nHA lyophilized scaffolds. In a drawback, all scaffolds have lost their mechanical properties by 95% on the 2nd day when fully immersed in phosphate buffered saline. Additionally live and dead cell assay showed no cytotoxicity and excellent osteoblast attachment to both lyophilized and LSD scaffolds at the end of 14th day of in vitro

  11. Increased Leg Bone Mineral Density and Content During the Initial Years of College Sport.

    Science.gov (United States)

    Scerpella, John J; Buehring, Bjoern; Hetzel, Scott J; Heiderscheit, Bryan C

    2018-04-01

    Scerpella, JJ, Buehring, B, Hetzel, SJ, and Heiderscheit, BC. Increased leg bone mineral density and content during the initial years of college sport. J Strength Cond Res 32(4): 1123-1130, 2018-Bone mineral density (BMD) and bone mineral content (BMC) data are useful parameters for evaluating how training practices promote bone health. We used dual-energy X-ray absorptiometry (DXA) to longitudinally assess sport-specific growth in leg and total body BMD/BMC over the initial 2 years of collegiate training. Eighty-five Division 1 collegiate basketball, hockey, and soccer athletes (50 males and 35 females; age 19.0 [0.8] years) underwent annual DXA scans. Leg and total body BMD/BMC were compared within and across two 1-year intervals (periods 1 and 2) using repeated-measures analysis of variance, adjusting for age, sex, race, and sport. Leg BMD, leg BMC, and total body BMC all increased over period 1 (0.05 g·cm [p = 0.001], 0.07 kg [p = 0.002], and 0.19 kg [p BMC (p BMC (p = 0.005). Leg lean mass increased more during period 2 than period 1 (p = 0.018). Sports participation was the only significant predictor of change in leg BMD. Significant increases in both leg BMD and BMC were demonstrated over both 2-year periods, with greater gains during period 1. These gains highlight the importance of attentive training procedures, capitalizing on attendant physical benefits of increased BMD/BMC. Additional research in young adults, evaluating bone mass acquisition, will optimize performance and decrease risk of bone stress injury among collegiate athletes.

  12. Increased FDG bone marrow uptake after intracoronary progenitor cell therapy

    Energy Technology Data Exchange (ETDEWEB)

    Doebert, N.; Menzel, C.; Diehl, M.; Hamscho, N.; Zaplatnikov, K.; Gruenwald, F. [Dept. of Nuclear Medicine, Univ. of Frankfurt (Germany)

    2005-02-01

    Patients with coronary artery disease who undergo FDG PET for therapy monitoring after intracoronary progenitor cell infusion (PCT) show an increased bone marrow uptake in some cases. Aim of the study was to evaluate the systemic bone marrow glucose metabolism in this patient group after PCT. Patients, methods: FDG bone marrow uptake (BMU), measured as standardized uptake value (SUVmax) in the thoracic spine, was retrospectively evaluated in 23 control patients who did not receive PCT and in 75 patients who received PCT 3{+-}2.2 days before PET scanning. Five out of them were pretreated with granulocyte colony-stimulating factor (G-CSF) 5 days prior to PCT and 10{+-}1.2 days before PET scanning. In 39 patients who received only PCT without G-CSF and underwent PET therapy monitoring 4 months later, baseline and follow up bone marrow uptake were measured. Leucocytes, C-reactive protein (CRP) levels and the influence of nicotine consumption were compared with the BMU. Results: In patients (n=70) who received PCT without G-CSF, BMU media (1.3) was slightly, but significantly higher than in the controls (1.0) (p=0.02) regardless nicotine consumption. BMU did not change significantly 4 months later (1.2) (p=0.41, n.s.). After G-CSF pretreatment, patients showed a significantly higher bone marrow uptake (3.7) compared to patients only treated with PCT (1.3) (p=0.023). Leucocyte blood levels were significantly higher in patients with a BMU {>=}2.5 compared to patients with a bone marrow SUVmax<2.5 (p<0.001). CRP values did not correlate with the BMU (rho -0.02, p=0.38). Conclusion: Monitoring PCT patients, a slightly increased FDG BMU may be observed which remains unchanged for several months. Unspecific bone marrow reactions after PCT may be associated with increased leucocyte blood levels and play a role in the changed systemic glucose BMU. In addition, pretreatment with G-CSF shows an intense amplitifcation of BMU. (orig.)

  13. Massage therapy during early postnatal life promotes greater lean mass and bone growth, mineralization, and strength in juvenile and young adult rats.

    Science.gov (United States)

    Chen, H; Miller, S; Shaw, J; Moyer-Mileur, L

    2009-01-01

    The objects of this study were to investigate the effects of massage therapy during early life on postnatal growth, body composition, and skeletal development in juvenile and young adult rats. Massage therapy was performed for 10 minutes daily from D6 to D10 of postnatal life in rat pups (MT, n=24). Body composition, bone area, mineral content, and bone mineral density were measured by dual energy X-ray absorptiometry (DXA); bone strength and intrinsic stiffness on femur shaft were tested by three-point bending; cortical and cancellous bone histomorphometric measurements were performed at D21 and D60. Results were compared to age- and gender-matched controls (C, n=24). D21 body weight, body length, lean mass, and bone area were significantly greater in the MT cohort. Greater bone mineral content was found in male MT rats; bone strength and intrinsic stiffness were greater in D60 MT groups. At D60 MT treatment promoted bone mineralization by increasing trabecular mineral apposition rate in male and endosteal mineral surface in females, and also improved micro-architecture by greater trabeculae width in males and decreasing trabecular separation in females. In summary, massage therapy during early life elicited immediate and prolonged anabolic effects on postnatal growth, lean mass and skeletal developmental in a gender-specific manner in juvenile and young adult rats.

  14. The influence of water removal on the strength and toughness of cortical bone

    OpenAIRE

    Nyman, Jeffry S.; Roy, Anuradha; Shen, Xinmei; Acuna, Rae L.; Tyler, Jerrod H.; Wang, Xiaodu

    2006-01-01

    Although the effects of dehydration on the mechanical behavior of cortical bone are known, the underlying mechanisms for such effects are not clear. We hypothesize that the interactions of water with the collagen and mineral phases each have a unique influence on mechanical behavior. To study this, strength, toughness, and stiffness were measured with three-point bend specimens made from the mid-diaphysis of human cadaveric femurs and divided into six test groups: control (hydrated), drying i...

  15. Design and Fabrication of 3D printed Scaffolds with a Mechanical Strength Comparable to Cortical Bone to Repair Large Bone Defects

    OpenAIRE

    Roohani-Esfahani, Seyed-Iman; Newman, Peter; Zreiqat, Hala

    2016-01-01

    A challenge in regenerating large bone defects under load is to create scaffolds with large and interconnected pores while providing a compressive strength comparable to cortical bone (100?150?MPa). Here we design a novel hexagonal architecture for a glass-ceramic scaffold to fabricate an anisotropic, highly porous three dimensional scaffolds with a compressive strength of 110?MPa. Scaffolds with hexagonal design demonstrated a high fatigue resistance (1,000,000 cycles at 1?10?MPa compressive...

  16. Body Composition, Muscular Strength and Bone Status among Undernourished Children in Malaysia

    International Nuclear Information System (INIS)

    Chong, Kar Hau; Poh, Bee Koon

    2014-01-01

    Full text: Despite significant advances in social and economic development, undernutrition remains a devastating public health problem that affects millions of children across the globe, particularly in developing nations. It is important to understand how changes in nutritional status affect physical health and function, so that undernutrition-related alterations can be identified and interpreted correctly. This paper aimed to determine the impact of undernutrition in children through the assessment of three nutrition-related indicators: body composition, muscular strength and bone status. This study is part of the Nutrition Survey of Malaysian Children, which is part of the four-country South East Asian Nutrition Surveys (SEANUTS). A total of 208 school children (102 boys, 106 girls) in the age range of 7 to 10 years were included in this analysis, of which 104 were underweight (WAZ<-2SD) and 104 were normal-weight group (-2SD≤WAZ≤+2SD), individually-matched for sex, age, and ethnicity. Anthropometric measurements included weight and height; and body composition was measured by bioelectrical impedance analysis. Muscular strength of both hands was assessed independently by hand-held dynamometer. Bone status was evaluated using a radial quantitative ultrasound system at one-third distal radius of the non-dominant hand. Anthropometric measurements and bone status were not significantly different between the sexes. Boys had significantly higher muscular strength and lean mass (p<0.05), but lower fat mass when compared to the girls (p<0.01). In both sexes, the undernourished group presented significantly lower anthropometric and body composition measurements and muscular strength than their normal-weight counterparts (p<0.001). However, no significant differences were observed for bone status between the two weight groups in boys (p = 0.09) and girls (p = 0.98). These findings imply that undernutrition can have profound negative impact on body composition as well

  17. Mitochondrial Point Mutation m.3243A>G Associates With Lower Bone Mineral Density, Thinner Cortices, and Reduced Bone Strength

    DEFF Research Database (Denmark)

    Langdahl, Jakob Høgild; Frederiksen, Anja Lisbeth; Hansen, Stinus Jørn

    2017-01-01

    Mitochondrial dysfunction is associated with several clinical manifestations including diabetes mellitus (DM), neurological disorders, renal and hepatic diseases, and myopathy. Although mitochondrial dysfunction is associated with increased bone resorption and decreased bone formation in mouse...... at the lumbar spine, total hip, and femoral neck in cases. Mean lumbar spine, total hip, and femoral neck T-scores were -1.5, -1.3, and -1.6 in cases, respectively, and -0.8, -0.3, and -0.7 in controls (all p G mutation was associated with lower BMD, cortical but not trabecular density...

  18. The impact of peripheral serotonin on leptin-brain serotonin axis, bone metabolism and strength in growing rats with experimental chronic kidney disease.

    Science.gov (United States)

    Pawlak, Dariusz; Domaniewski, Tomasz; Znorko, Beata; Oksztulska-Kolanek, Ewa; Lipowicz, Paweł; Doroszko, Michał; Karbowska, Malgorzata; Pawlak, Krystyna

    2017-12-01

    Chronic kidney disease (CKD) results in decreased bone strength. Serotonin (5-HT) is one of the critical regulators of bone health, fulfilling distinct functions depending on its synthesis site: brain-derived serotonin (BDS) favors osteoblast proliferation, whereas gut-derived serotonin (GDS) inhibits it. We assessed the role of BDS and peripheral leptin in the regulation of bone metabolism and strength in young rats with 5/6 nephrectomy. BDS synthesis was accelerated during CKD progression. Decreased peripheral leptin in CKD rats was inversely related to BDS content in the hypothalamus, brainstem and frontal cortex. Serotonin in these brain regions affected bone strength and metabolism in the studied animals. The direct effect of circulating leptin on bone was not shown in uremia. At the molecular level, there was an inverse association between elevated GDS and the expression of cAMP responsive element-binding protein (Creb) gene in bone of CKD animals. In contrast, increased expression of activating transcription factor 4 (Atf4) was shown, which was associated with GDS-dependent transcription factor 1 (Foxo1), clock gene - Cry-1, cell cycle genes: c-Myc, cyclins, and osteoblast differentiation genes. These results identified a previously unknown molecular pathway, by which elevated GDS can shift in Foxo1 target genes from Creb to Atf4-dependent response, disrupting the leptin-BDS - dependent gene pathway in the bone of uremic rats. Thus, in the condition of CKD the effect of BDS and GDS on bone metabolism and strength can't be distinguished. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Relationship of total body fat mass to weight-bearing bone volumetric density, geometry, and strength in young girls.

    Science.gov (United States)

    Farr, Joshua N; Chen, Zhao; Lisse, Jeffrey R; Lohman, Timothy G; Going, Scott B

    2010-04-01

    Understanding the influence of total body fat mass (TBFM) on bone during the peri-pubertal years is critical for the development of future interventions aimed at improving bone strength and reducing fracture risk. Thus, we evaluated the relationship of TBFM to volumetric bone mineral density (vBMD), geometry, and strength at metaphyseal and diaphyseal sites of the femur and tibia of young girls. Data from 396 girls aged 8-13 years from the "Jump-In: Building Better Bones" study were analyzed. Bone parameters were assessed using peripheral quantitative computed tomography (pQCT) at the 4% and 20% distal femur and 4% and 66% distal tibia of the non-dominant leg. Bone parameters at the 4% sites included trabecular vBMD, periosteal circumference, and bone strength index (BSI), while at the 20% femur and 66% tibia, parameters included cortical vBMD, periosteal circumference, and strength-strain index (SSI). Multiple linear regression analyses were used to assess associations between bone parameters and TBFM, controlling for muscle cross-sectional area (MCSA). Regression analyses were then repeated with maturity, bone length, physical activity, and ethnicity as additional covariates. Analysis of covariance (ANCOVA) was used to compare bone parameters among tertiles of TBFM. In regression models with TBFM and MCSA, associations between TBFM and bone parameters at all sites were not significant. TBFM explained very little variance in all bone parameters (0.2-2.3%). In contrast, MCSA was strongly related (p<0.001) to all bone parameters, except cortical vBMD. The addition of maturity, bone length, physical activity, and ethnicity did not alter the relationship between TBFM and bone parameters. With bone parameters expressed relative to total body mass, ANCOVA showed that all outcomes were significantly (p<0.001) greater in the lowest compared to the middle and highest tertiles of TBFM. Although TBFM is correlated with femur and tibia vBMD, periosteal circumference, and

  20. The effects of boron supplementation of layer diets varying in calcium and phosphorus concentrations on performance, egg quality, bone strength and mineral constituents of serum, bone and faeces.

    Science.gov (United States)

    Küçükyilmaz, K; Erkek, R; Bozkurt, M

    2014-01-01

    1. A 2 × 3 factorial arrangement of treatments was used to investigate the effects of dietary calcium (Ca), phosphorus (P), and supplemental boron (B) (0, 75, and 150 mg/kg) on the performance, egg quality, bone strength, and mineral constituents in bone, serum and faeces. 2. A reduction by 18% in the dietary Ca-P concentration from the recommended levels for the hen strain reduced (P properties did not corroborate the hypothesis that B is a trace element playing an important role in mineral metabolism and bone strength through an interaction with Ca, P and Mg.

  1. Muscle strength and regional lean body mass influence on mineral bone health in young male adults.

    Science.gov (United States)

    Guimarães, Bianca Rosa; Pimenta, Luciana Duarte; Massini, Danilo Alexandre; Dos Santos, Daniel; Siqueira, Leandro Oliveira da Cruz; Simionato, Astor Reis; Dos Santos, Luiz Gustavo Almeida; Neiva, Cassiano Merussi; Pessôa Filho, Dalton Muller

    2018-01-01

    The relationship between muscle strength and bone mineral content (BMC) and bone mineral density (BMD) is supposed from the assumption of the mechanical stress influence on bone tissue metabolism. However, the direct relationship is not well established in younger men, since the enhancement of force able to produce effective changes in bone health, still needs to be further studied. This study aimed to analyze the influence of muscle strength on BMC and BMD in undergraduate students. Thirty six men (24.9 ± 8.6 y/o) were evaluated for regional and whole-body composition by dual energy X-ray absorptiometry (DXA). One repetition maximum tests (1RM) were assessed on flat bench-press (BP), lat-pull down (LPD), leg-curl (LC), knee extension (KE), and leg-press 45° (LP45) exercises. Linear regression modelled the relationships of BMD and BMC to the regional body composition and 1RM values. Measurements of dispersion and error (R2adj and standard error of estimate (SEE)) were tested, setting ρ at ≤0.05. The BMD mean value for whole-body was 1.12±0.09 g/cm2 and BMC attained 2477.9 ± 379.2 g. The regional lean mass (LM) in upper-limbs (UL) (= 6.80±1.21 kg) was related to BMC and BMD for UL (R2adj = 0.74, pBMC and BMD for LL (R2adj = 0.68, pBMC (R2adj = 0.47, pBMC (R2adj = 0.36, pBMC and BMD in young men, strengthening the relationship between force and LM, and suggesting both to parametrizes bone mineral health.

  2. Bone Structural Changes and Estimated Strength After Gastric Bypass Surgery Evaluated by HR-pQCT

    DEFF Research Database (Denmark)

    Frederiksen, Katrine Diemer; Hanson, Stine; Hansen, Stinus

    2016-01-01

    Roux-en-Y gastric bypass surgery (RYGB) is an effective treatment of morbid obesity, with positive effects on obesity-related complications. The treatment is associated with bone loss, which in turn might increase fracture risk. The aim of this study was to evaluate changes in bone mineral density...... (BMD) and bone architecture assessed using dual-energy X-ray absorptiometry (DXA) and high-resolution peripheral quantitative computed tomography (HR-pQCT), 6 and 12 months after RYGB, and correlate them to changes in selected biochemical markers. A prospective cohort study included 25 morbidly obese...

  3. The effect of calcium and magnesium supplementation on performance and bone strength of broiler chickens

    Directory of Open Access Journals (Sweden)

    Filip Karásek

    2017-01-01

    Full Text Available Aim of the experiment was evaluation of the effect of reduced calcium and magnesium content in the broiler chickens diet on its parameters of fattening, bone strength and calcium and magnesium content in liver. The trial was performed with cockerels of Ross 308 hybrid (n = 160 which were fattened in cage batteries from day 11th to 36th day of age. Cockerels were divided into 4 groups (differ in various intake levels of calcium and magnesium in four replications. The maize-wheat-soybean basal diet contained 2.33 g Ca and 1.58 g Mg per kilogram. Calcium was added by CaCO3 and magnesium by MgSO4. Control group (C received feed mixture with added CaCO3 in dose of 19.49 g.kg-1 and 0.41 g.kg-1 of MgSO4. Three experimental groups contain added CaCO3 in dose of 11.83 g.kg-1 and 0 g.kg-1 MgSO4 (group Exp1; CaCO3 11.83 g.kg-1 and 0.41 g.kg-1 MgSO4 (group Exp2; CaCO3 19.49 g.kg-1 and 0 g.kg-1 MgSO4 (group Exp3, respectively. The feed consumption was daily monitored and the cockerels were weighed twice a week. At the end of the study the experimental animals were weighted and slaughtered by decapitation. The weight of carcasses, liver and proportion of breast and thigh muscle was determined in the selected chickens (n = 24. The atomic absorption spectrometry was used for Ca and Mg evaluation in liver tissues. Bone strength parameter was measured at the femur bone. The statistically significant differences (p >0.05 were not detected between control and experimental groups in the case of studied parameters of fattening, bone strength and calcium and magnesium content in the chicken´s liver. Based on the obtained results it could be concluded the reduction of determined elements in the chicken diet did not deteriorate parameters of yield, elements content in liver tissue as well as the bone strength of broiler chickens. Normal 0 21 false false false CS X-NONE X-NONE

  4. Design and Fabrication of 3D printed Scaffolds with a Mechanical Strength Comparable to Cortical Bone to Repair Large Bone Defects

    Science.gov (United States)

    Roohani-Esfahani, Seyed-Iman; Newman, Peter; Zreiqat, Hala

    2016-01-01

    A challenge in regenerating large bone defects under load is to create scaffolds with large and interconnected pores while providing a compressive strength comparable to cortical bone (100-150 MPa). Here we design a novel hexagonal architecture for a glass-ceramic scaffold to fabricate an anisotropic, highly porous three dimensional scaffolds with a compressive strength of 110 MPa. Scaffolds with hexagonal design demonstrated a high fatigue resistance (1,000,000 cycles at 1-10 MPa compressive cyclic load), failure reliability and flexural strength (30 MPa) compared with those for conventional architecture. The obtained strength is 150 times greater than values reported for polymeric and composite scaffolds and 5 times greater than reported values for ceramic and glass scaffolds at similar porosity. These scaffolds open avenues for treatment of load bearing bone defects in orthopaedic, dental and maxillofacial applications.

  5. Increased bone calcium dissociation in lead-exposed rats

    Directory of Open Access Journals (Sweden)

    Eko Suhartono

    2012-12-01

    Full Text Available Background Lead is still a major environmental and occupational health hazard, since it is extensively used in the production of paints, gasoline and cosmetics. This causes the metal to be ubiquitous in the environment, being found in the air, soil, and water, from which it can enter the human body by inhalation or ingestion. Absorbed lead is capable of altering the calcium levels in bone. The aim of this study was to demonstrate the effect of lead on bone calcium levels by measuring the reaction constant, Gibbs free energy, and enthalpy. Methods This study was of pure experimental design using 100 male albino rats (Rattus norvegicus. The experimental animals were assigned by simple randomization to two groups, one group receiving lead acetate orally at a dosage of 100 mg/kgBW, while the other group did not receive lead acetate. The intervention was given for 4 weeks and the rats were observed weekly for measurement of bone calcium levels by the permanganometric method. Results This study found that k1 (hydroxyapatite dissociation rate constant was 0.90 x 10-3 dt-1, and that k2 (hydroxyapatite association rate constant was 6.16 x 10-3 dt-1 for the control group, whereas for the intervention group k1 = 26.20 x 10-3 dt-1 and k2 = 16.75 x 10-3 dt-1. Thermodynamically, the overall reaction was endergonic and endothermic (DG > 0 and DH > 0. ConclusionS Lead exposure results in increased dissociation rate of bone in comparison with its association rate. Overall, the reaction was endergonic and endothermic (DG > 0 and DH > 0.

  6. Increased bone calcium dissociation in lead-exposed rats

    Directory of Open Access Journals (Sweden)

    Eko Suhartono

    2015-12-01

    Full Text Available BACKGROUND Lead is still a major environmental and occupational health hazard, since it is extensively used in the production of paints, gasoline and cosmetics. This causes the metal to be ubiquitous in the environment, being found in the air, soil, and water, from which it can enter the human body by inhalation or ingestion. Absorbed lead is capable of altering the calcium levels in bone. The aim of this study was to demonstrate the effect of lead on bone calcium levels by measuring the reaction constant, Gibbs free energy, and enthalpy. METHODS This study was of pure experimental design using 100 male albino rats (Rattus norvegicus. The experimental animals were assigned by simple randomization to two groups, one group receiving lead acetate orally at a dosage of 100 mg/ kgBW, while the other group did not receive lead acetate. The intervention was given for 4 weeks and the rats were observed weekly for measurement of bone calcium levels by the permanganometric method. RESULTS This study found that k1 (hydroxyapatite dissociation rate constant was 0.90 x 10-3 dt-1, and that k2 (hydroxyapatite association rate constant was 6.16 x 10-3 dt-1 for the control group, whereas for the intervention group k1 = 26.20 x 10-3 dt-1 and k2 = 16.75 x 10-3 dt-1. Thermodynamically, the overall reaction was endergonic and endothermic (ΔG > 0 and ΔH > 0. CONCLUSIONS Lead exposure results in increased dissociation rate of bone in comparison with its association rate. Overall, the reaction was endergonic and endothermic (ΔG > 0 and ΔH > 0.

  7. Diffusely increased uptake in the skull in normal bone scans

    International Nuclear Information System (INIS)

    Suematsu, Toru; Yoshida, Shoji; Motohara, Tomofumi; Fujiwara, Hirofumi; Nishii, Hironori; Komiyama, Toyozo; Yanase, Masakazu; Mizutani, Masahiro

    1992-01-01

    Diffusely increased skull uptake (a hot skull) is often seen in patients with bone metastases and metabolic disease. This finding is also, however, noticed in normal bone scans of aged women. To determine whether the hot skull could be considered a normal variant in elderly women and is associated to menopause, we studied 282 normal bone scans (166 women and 116 men without metabolic and hormonal disease; age range 11 to 84 yr). We divided the patients into eight age groups--ages 10-19, 20-29, 30-39, 40-49, 50-59, 60-69, 70-79, and 80-89 yrs. Measurements of skull uptake were obtained from anterior total body views using contrast-to-noise ratio (CNR). CNR for the skull was calculated using an equation. The sex dependent difference in skull uptake began to develop in the age group 30-39 yrs (p<0.05). The skull showed greater activity in women than in men for age groups from 30-39 to 80-89 yrs. In the age groups 50-59 and 60-69, the difference was particularly large (p<0.001). For women, the 50-59 yr age group had a significantly higher CNR than the 40-49 yr (p<0.01), 30-39 yr (p<0.05), and 20-29 yr age group (p<0.05). On the other hand, there was no significant difference between the 20-29 yr, 30-39 yr and 40-49 yr age groups. For men, the skull uptake was virtually unchanged with age. Our data strongly suggested that the hot skull in normal bone scan is related to menopausal estrogen deficiency. One should not necessarily regard it abnormal that elderly women suffer hot skull. (J.P.N.)

  8. [Different strength intermittent treadmill training of growth period rats and related bone metabolism of the hormone influence].

    Science.gov (United States)

    Xie, Shun-cheng; Ma, Xue-jun; Guo, Cheng-ji; Liu, Hong-zhen

    2012-05-01

    To explore the influence of different strength intermittent treadmill training of growth period rats on the bone metabolism, so as to provide the training intensity of teenagers to set theory support. Select 70 male four weeks Wistar rats according to body weight randomly divided into seven groups (n = 10): the control group and the exercise group. According to the VO2max the exercise group was divided into 6 groups: 65%, 70%, 75%, 80%, 85% and 90% group. Nine weeks treadmill training, training six days a week, each group of training three times, each time not less than 10min, the interval was 30 min. The last movement after 24 h, took the femur and blood to measured the bone mineral density (BMD), bone mass (BMC) and alkaline phosphatase (AKP), resist tartaric acid acidic phosphatase (Str-ACP). 1. The femoral BMD (0.1393 +/- 0.0031), BMC (0.4525 +/- 0.0335) of 70% group were significantly higher than those in the control group (BMD: 0.1200 +/- 0.0095, BMC: 0.3238 +/- 0.0485) and the other sports group (65% BMD:0.1339 +/- 0.0062, BMC: 0.4058 +/- 0.0492, 75% BMD: 0.1296 +/- 0.0015, BMC: 0.3869 +/- 0.0254, 80% BMD: 0.1223 +/- 0.0082, BMC: 0.3454 +/- 0.0483, 85% BMD: 0.1250 +/- 0.0044, BMC: 0.3731 +/- 0.0381, 90% BMD: 0.1171 +/- 0.0047, BMC: 0.3051 +/- 0.0286) (P growth period rat bone mass and bone mineral density to increase obviously.

  9. Influence of muscle strength, physical activity and weight on bone mass in a population-based sample of 1004 elderly women.

    Science.gov (United States)

    Gerdhem, P; Ringsberg, K A M; Akesson, K; Obrant, K J

    2003-09-01

    High physical activity level has been associated with high bone mass and low fracture risk and is therefore recommended to reduce fractures in old age. The aim of this study was to estimate the effect of potentially modifiable variables, such as physical activity, muscle strength, muscle mass and weight, on bone mass in elderly women. The influence of isometric thigh muscle strength, self-estimated activity level, body composition and weight on bone mineral density (dual energy X-ray absorptiometry; DXA) in total body, hip and spine was investigated. Subjects were 1004 women, all 75 years old, taking part in the Malmö Osteoporosis Prospective Risk Assessment (OPRA) study. Physical activity and muscle strength accounted for 1-6% of the variability in bone mass, whereas weight, and its closely associated variables lean mass and fat mass, to a much greater extent explained the bone mass variability. We found current body weight to be the variable with the most substantial influence on the total variability in bone mass (15-32% depending on skeletal site) in a forward stepwise regression model. Our findings suggest that in elderly women, the major fracture-preventive effect of physical activity is unlikely to be mediated through increased bone mass. Retaining or even increasing body weight is likely to be beneficial to the skeleton, but an excess body weight increase may have negative effects on health. Nevertheless, training in elderly women may have advantages by improving balance, co-ordination and mobility and therefore decreasing the risk of fractures.

  10. The antiarrhythmic peptide analog rotigaptide (ZP123) stimulates gap junction intercellular communication in human osteoblasts and prevents decrease in femoral trabecular bone strength in ovariectomized rats

    DEFF Research Database (Denmark)

    Jørgensen, Niklas Rye; Teilmann, Stefan Cuoni; Henriksen, Zanne

    2005-01-01

    Gap junctions play an important role in bone development and function, but the lack of pharmacological tools has hampered the gap junction research. The antiarrhythmic peptides stimulate gap junction communication between cardiomyocytes, but effects in noncardiac tissue are unknown. The purpose...... of this study was to examine whether antiarrhythmic peptides, which are small peptides increasing gap junctional conductivity, show specific binding to osteoblasts and investigate the effect of the stable analog rotigaptide (ZP123) on gap junctional intercellular communication in vitro and on bone mass...... and strength in vivo. Cell coupling and calcium signaling were assessed in vitro on human, primary, osteoblastic cells. In vivo effects of rotigaptide on bone strength and density were determined 4 wk after ovariectomy in rats treated with either vehicle, sc injection twice daily (300 nmol per kilogram body...

  11. Pullout strength of bone-patellar tendon-bone allograft bone plugs: a comparison of cadaver tibia and rigid polyurethane foam.

    Science.gov (United States)

    Barber, F Alan

    2013-09-01

    To compare the load-to-failure pullout strength of bone-patellar tendon-bone (BPTB) allografts in human cadaver tibias and rigid polyurethane foam blocks. Twenty BPTB allografts were trimmed creating 25 mm × 10 mm × 10 mm tibial plugs. Ten-millimeter tunnels were drilled in 10 human cadaver tibias and 10 rigid polyurethane foam blocks. The BPTB anterior cruciate ligament allografts were inserted into these tunnels and secured with metal interference screws, with placement of 10 of each type in each material. After preloading (10 N), cyclic loading (500 cycles, 10 to 150 N at 200 mm/min) and load-to-failure testing (200 mm/min) were performed. The endpoints were ultimate failure load, cyclic loading elongation, and failure mode. No difference in ultimate failure load existed between grafts inserted into rigid polyurethane foam blocks (705 N) and those in cadaver tibias (669 N) (P = .69). The mean rigid polyurethane foam block elongation (0.211 mm) was less than that in tibial bone (0.470 mm) (P = .038), with a smaller standard deviation (0.07 mm for foam) than tibial bone (0.34 mm). All BPTB grafts successfully completed 500 cycles. The rigid polyurethane foam block showed less variation in test results than human cadaver tibias. Rigid polyurethane foam blocks provide an acceptable substitute for human cadaver bone tibia for biomechanical testing of BPTB allografts and offer near-equivalent results. Copyright © 2013 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

  12. Bisphosphonate-adsorbed ceramic nanoparticles increase bone formation in an injectable carrier for bone tissue engineering

    Directory of Open Access Journals (Sweden)

    Tegan L Cheng

    2015-10-01

    Full Text Available Sucrose acetate isobutyrate (SAIB is a sugar-based carrier. We have previously applied SAIB as a minimally invasive system for the co-delivery of recombinant human bone morphogenetic protein-2 (rhBMP-2 and found synergy when co-delivering zoledronic acid (ZA and hydroxyapatite (HA nanoparticles. Alternative bioceramics were investigated in a murine SAIB/rhBMP-2 injection model. Neither beta-tricalcium phosphate (TCP nor Bioglass (BG 45S5 had a significant effect on bone volume (BV alone or in combination with the ZA. 14C-labelled ZA binding assays showed particle size and ceramic composition affected binding with nano-HA > micro-HA > TCP > BG. Micro-HA and nano-HA increased BV in a rat model of rhBMP-2/SAIB injection (+278% and +337%, and BV was further increased with ZA–adsorbed micro-HA and nano-HA (+530% and +889%. These data support the use of ZA–adsorbed nanoparticle-sized HA as an optimal additive for the SAIB/rhBMP-2 injectable system for bone tissue engineering.

  13. Repeated oral administration of a cathepsin K inhibitor significantly suppresses bone resorption in exercising horses with evidence of increased bone formation and maintained bone turnover.

    Science.gov (United States)

    Hussein, H; Dulin, J; Smanik, L; Drost, W T; Russell, D; Wellman, M; Bertone, A

    2017-08-01

    Our investigations evaluated the effect of VEL-0230, a highly specific irreversible inhibitor of cathepsin K (CatK). The objectives of our study were to determine whether repeated dosing of a CatK inhibitor (CatKI) produced a desired inhibition of the bone resorption biomarker (CTX-1), and document the effect of repeated dosing on bone homeostasis, structure, and dynamics of bone resorption and formation in horses. Twelve young exercising horses were randomized in a prospective, controlled clinical trial and received 4 weekly doses of a CatKI or vehicle. Baseline and poststudy nuclear scintigraphy, blood sampling and analysis of plasma bone biomarkers (CTX-1 and osteocalcin), poststudy bone fluorescent labeling, and bone biopsy were performed. Bone specimens were further processed for microcomputed tomography and bone histomorphometry. Each dose of this CatKI transiently inhibited plasma CTX-1 (reflecting inhibition of bone collagen resorption) and increased bone plasma osteocalcin concentrations, with no detectable adverse effect on normal bone turnover in the face of exercise. Bone morphology, density, and formation rate were not different between control and treated group. Further investigation of CatK inhibition in abnormal bone turnover is required in animals with bone diseases. © 2016 John Wiley & Sons Ltd.

  14. Unique effects of energy versus estrogen deficiency on multiple components of bone strength in exercising women.

    Science.gov (United States)

    Southmayd, E A; Mallinson, R J; Williams, N I; Mallinson, D J; De Souza, M J

    2017-04-01

    Many female athletes are energy and/or estrogen deficient, but the independent effects on bone health have not been isolated. Energy deficiency was detrimental at the tibia while estrogen deficiency was detrimental at the radius. Nutrition must be considered alongside menstrual recovery when addressing compromised bone health in female athletes. The purpose of this study was to describe volumetric bone mineral density (vBMD), bone geometry, and estimated bone strength in exercising women (n = 60) grouped according to energy status (energy replete (EnR: n = 30) vs. energy deficient (EnD: n = 30)) and estrogen status (estrogen replete (E 2 R: n = 33) vs. estrogen deficient (E 2 D: n = 27)), resulting in four distinct groups: EnR + E 2 R (n = 17), EnR + E 2 D (n = 13), EnD + E 2 R (n = 16), EnD + E 2 D (n = 14). Energy status was determined using the ratio of measured to predicted resting energy expenditure (mREE/pREE). Estrogen status was based on self-reported menstrual status confirmed by daily evaluation of urinary estrone-1-glucoronide (E1G), pregnanediol glucuronide (PdG), and luteinizing hormone (LH). Eumenorrheic women were considered E 2 R, amenorrheic women were E 2 D, and oligomenorrheic women were categorized based on history of menses in the past year. Bone was assessed using peripheral quantitative computed tomography (pQCT). EnD women exhibited lower total vBMD, trabecular vBMD, cortical area, and BSI at the distal tibia and lower total vBMD, smaller cortical area and cortical thickness, and larger endosteal circumference at the proximal tibia compared to EnR women (p < 0.042). E 2 D women had lower total and cortical vBMD, larger total and trabecular area, and lower BSI at the distal radius and lower cortical vBMD at the proximal radius compared to E 2 R women (p < 0.023). Energy and estrogen interacted to affect total and trabecular area at the distal tibia (p < 0.021). Efforts to correct energy deficiency, which in turn may

  15. Influence of Nordic Walking Training on Muscle Strength and the Electromyographic Activity of the Lower Body in Women With Low Bone Mass

    Directory of Open Access Journals (Sweden)

    Ossowski Zbigniew

    2016-06-01

    Full Text Available Introduction. Osteoporosis and osteopenia are related to changes in the quantity and quality of skeletal muscle and contribute to a decreased level of muscle strength. The purpose of this study was to evaluate the impact of Nordic walking training on muscle strength and the electromyographic (EMG activity of the lower body in women with low bone mass. Material and methods. The participants of the study were 27 women with low bone mass. The sample was randomly divided into two groups: a control group and an experimental group. Women from the experimental group participated in 12 weeks of regular Nordic walking training. Functional strength was assessed with a 30-second chair stand test. The EMG activities of the gluteus maximus (GMax, rectus femoris (RF, biceps femoris (BF, soleus (SOL, and lumbar (LB muscles were measured using a surface electromyogram. Results. Nordic walking training induced a significant increase in the functional strength (p = 0.006 of the lower body and activity of GMax (p = 0.013 and a decrease in body mass (p = 0.006 in women with reduced bone mass. There was no statistically significant increase in the EMG activities of the RF, BF, SOL, or LB muscles. The study did not indicate any significant changes in functional muscle strength, the EMG activity of the lower body, or anthropometry in women from the control group. Conclusions. Nordic walking training induces positive changes in lower body strength and the electromyographic activity of the gluteus maximus as well as a decrease in body mass in women with low bone mass.

  16. The role of fat in the prediction of bone strength of porcine lumbar vertebrae by quanititative computed tomography

    International Nuclear Information System (INIS)

    Chang, G.L.; Tsai, K.H.; Yu, C.Y.; Lin, R.M.

    1996-01-01

    In order to prevent cancellous bone fractures, and understanding of the strength characteristics of cancellous bone must be achieved. Although there is a definite relationship between the strengt and relative ash content of the vertebrae, the well-known relationship is not practical in clinical use. As we know, QCT was regarded as an ideal method because it is a cross-sectional tecnique. However, no matter what kind of CT machine was used, the physiological factor must be influencing the accuracy in QCT measurement. Because a given region of the vertebrae contains bone mineral, bone matrix, fatty marrow and red marrow. In words, the role of fat content in bony strength and QCT measurement remained obscure. If QCT can reflect the bone strength to a reliable level and the influence of fat on QCT can be clarified, then QCT may become more useful. Therefore, the purpose of this study was to investigate the relationships among fat content, bone strength and QCT. Six freshly female porcine lumbar spinal semgemts were used in this study. Poster 182. (author)

  17. Increased physical activity ameliorates high fat diet-induced bone resorption in mice

    Science.gov (United States)

    It has been recognized that mechanical stresses associated with physical activity (PA) have beneficial effects on increasing bone mineral density (BMD) and improving bone quality. On the other hand, high fat diet (HFD) and obesity increase bone marrow adiposity leading to increased excretion of pro-...

  18. Targeted exercise against osteoporosis: A systematic review and meta-analysis for optimising bone strength throughout life

    Directory of Open Access Journals (Sweden)

    Heinonen Ari

    2010-07-01

    Full Text Available Abstract Background Exercise is widely recommended to reduce osteoporosis, falls and related fragility fractures, but its effect on whole bone strength has remained inconclusive. The primary purpose of this systematic review and meta-analysis was to evaluate the effects of long-term supervised exercise (≥6 months on estimates of lower-extremity bone strength from childhood to older age. Methods We searched four databases (PubMed, Sport Discus, Physical Education Index, and Embase up to October 2009 and included 10 randomised controlled trials (RCTs that assessed the effects of exercise training on whole bone strength. We analysed the results by age groups (childhood, adolescence, and young and older adulthood and compared the changes to habitually active or sedentary controls. To calculate standardized mean differences (SMD; effect size, we used the follow-up values of bone strength measures adjusted for baseline bone values. An inverse variance-weighted random-effects model was used to pool the results across studies. Results Our quality analysis revealed that exercise regimens were heterogeneous; some trials were short in duration and small in sample size, and the weekly training doses varied considerably between trials. We found a small and significant exercise effect among pre- and early pubertal boys [SMD, effect size, 0.17 (95% CI, 0.02-0.32], but not among pubertal girls [-0.01 (-0.18 to 0.17], adolescent boys [0.10 (-0.75 to 0.95], adolescent girls [0.21 (-0.53 to 0.97], premenopausal women [0.00 (-0.43 to 0.44] or postmenopausal women [0.00 (-0.15 to 0.15]. Evidence based on per-protocol analyses of individual trials in children and adolescents indicated that programmes incorporating regular weight-bearing exercise can result in 1% to8% improvements in bone strength at the loaded skeletal sites. In premenopausal women with high exercise compliance, improvements ranging from 0.5% to 2.5% have been reported. Conclusions The findings

  19. Low calcium-phosphate intakes modulate the low-protein diet-related effect on peak bone mass acquisition: a hormonal and bone strength determinants study in female growing rats.

    Science.gov (United States)

    Fournier, C; Rizzoli, R; Ammann, P

    2014-11-01

    Peak bone mass acquisition is influenced by environmental factors including dietary intake. A low-protein diet delays body and skeletal growth in association with a reduction in serum IGF-1 whereas serum FGF21 is increased by selective amino acid deprivation. Calcium (Ca) and phosphorous (P) are also key nutrients for skeletal health, and inadequate intakes reduce bone mass accrual in association with calciotropic hormone modulation. Besides, the effect of calcium supplementation on bone mass in prepubertal children appears to be influenced by protein intake. To further explore the interaction of dietary protein and Ca-P intake on bone growth, 1-month-old female rats were fed with an isocaloric 10%, 7.5%, or 5% casein diet containing normal or low Ca-P for an 8-week period (6 groups). Changes in tibia geometry, mineral content, microarchitecture, strength, and intrinsic bone quality were analyzed. At the hormonal level, serum IGF-1, fibroblast growth factor 21 (FGF21), PTH, 1,25-dihydroxyvitamin D3 (calcitriol), and FGF23 were investigated as well as the Ghr hepatic gene expression. In normal dietary Ca-P conditions, bone mineral content, trabecular and cortical bone volume, and bone strength were lower in the 5% casein group in association with a decrease in serum IGF-1 and an increase in FGF21 levels. Unexpectedly, the low-Ca-P diet attenuated the 5% casein diet-related reduction of serum IGF-1 and Ghr hepatic gene expression, as well as the low-protein diet-induced decrease in bone mass and strength. However, this was associated with lower cortical bone material level properties. The low-Ca-P diet increased serum calcitriol but decreased FGF23 levels. Calcitriol levels positively correlated with Ghr hepatic mRNA levels. These results suggest that hormonal modulation in response to a low-Ca-P diet may modify the low-protein diet-induced effect on Ghr hepatic mRNA levels and consequently the impact of low protein intakes on IGF-1 circulating levels and skeletal

  20. Compromised trabecular microarchitecture and lower finite element estimates of radius and tibia bone strength in adults with turner syndrome

    DEFF Research Database (Denmark)

    Hansen, Stinus; Brixen, Kim; Gravholt, Claus H

    2012-01-01

    Although bone mass appear ample for bone size in Turner syndrome (TS), epidemiological studies have reported an increased risk of fracture in TS. We used high-resolution peripheral quantitative computed tomography (HR-pQCT) to measure standard morphological parameters of bone geometry...

  1. The effects of a 6-month resistance training and dried plum consumption intervention on strength, body composition, blood markers of bone turnover, and inflammation in breast cancer survivors.

    Science.gov (United States)

    Simonavice, Emily; Liu, Pei-Yang; Ilich, Jasminka Z; Kim, Jeong-Su; Arjmandi, Bahram; Panton, Lynn B

    2014-06-01

    The purpose of this study was to examine the effects of resistance training (RT) and dried plum (DP) consumption on strength, body composition, blood markers of bone, and inflammation in breast cancer survivors (BCS). Twenty-three BCS (RT, n = 12; RT+DP, n = 11), aged 64 ± 7 years, were evaluated at baseline and after 6 months of intervention on the following: muscular strength (chest press and leg extension) via 1-repetition maximums (1RMs); body composition, specifically bone mineral density (BMD) by dual energy X-ray absorptiometry; biochemical markers of bone turnover (bone-specific alkaline phosphatase (BAP), tartrate resistant acid phosphatase (TRAP-5b)); and inflammation (C-reactive protein (CRP)). Target RT prescription was 2 days/week of 10 exercises, including 2 sets of 8-12 repetitions at ∼60%-80% of 1RM. RT+DP also consumed 90 g of DP daily. There were no baseline differences between groups or any group-by-time interactions for any of the variables. BCS increased upper (p body strength. Body composition and BMD improvements were not observed. TRAP-5b decreased in the RT group (p body composition and biochemical markers of inflammation.

  2. The effect of increasing strength and approach velocity on triple jump performance.

    Science.gov (United States)

    Allen, Sam J; Yeadon, M R Fred; King, Mark A

    2016-12-08

    The triple jump is an athletic event comprising three phases in which the optimal phase ratio (the proportion of each phase to the total distance jumped) is unknown. This study used a planar whole body torque-driven computer simulation model of the ground contact parts of all three phases of the triple jump to investigate the effect of strength and approach velocity on optimal performance. The strength and approach velocity of the simulation model were each increased by up to 30% in 10% increments from baseline data collected from a national standard triple jumper. Increasing strength always resulted in an increased overall jump distance. Increasing approach velocity also typically resulted in an increased overall jump distance but there was a point past which increasing approach velocity without increasing strength did not lead to an increase in overall jump distance. Increasing both strength and approach velocity by 10%, 20%, and 30% led to roughly equivalent increases in overall jump distances. Distances ranged from 14.05m with baseline strength and approach velocity, up to 18.49m with 30% increases in both. Optimal phase ratios were either hop-dominated or balanced, and typically became more balanced when the strength of the model was increased by a greater percentage than its approach velocity. The range of triple jump distances that resulted from the optimisation process suggests that strength and approach velocity are of great importance for triple jump performance. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Treatment with soluble activin type IIB-receptor improves bone mass and strength in a mouse model of Duchenne muscular dystrophy.

    Science.gov (United States)

    Puolakkainen, Tero; Ma, Hongqian; Kainulainen, Heikki; Pasternack, Arja; Rantalainen, Timo; Ritvos, Olli; Heikinheimo, Kristiina; Hulmi, Juha J; Kiviranta, Riku

    2017-01-19

    Inhibition of activin/myostatin pathway has emerged as a novel approach to increase muscle mass and bone strength. Duchenne muscular dystrophy (DMD) is a neuromuscular disorder that leads to progressive muscle degeneration and also high incidence of fractures. The aim of our study was to test whether inhibition of activin receptor IIB ligands with or without exercise could improve bone strength in the mdx mouse model for DMD. Thirty-two mdx mice were divided to running and non-running groups and to receive either PBS control or soluble activin type IIB-receptor (ActRIIB-Fc) once weekly for 7 weeks. Treatment of mdx mice with ActRIIB-Fc resulted in significantly increased body and muscle weights in both sedentary and exercising mice. Femoral μCT analysis showed increased bone volume and trabecular number (BV/TV +80%, Tb.N +70%, P treatment of mdx mice with the soluble ActRIIB-Fc results in a robust increase in bone mass, without any additive effect by voluntary running. Thus ActRIIB-Fc could be an attractive option in the treatment of musculoskeletal disorders.

  4. Evaluation of mechanical strengths of three types of mini-implants in artificial bones

    Directory of Open Access Journals (Sweden)

    Yu-Chuan Tseng

    2017-02-01

    Full Text Available We investigates the effect of the anchor area on the mechanical strengths of infrazygomatic mini-implants. Thirty mini-implants were divided into three types based on the material and shape: Type A (titanium alloy, 2.0×12 mm, Type B (stainless steel, 2.0×12 mm, and Type C (titanium alloy, 2.0×11 mm.The mini-implants were inserted at 90° and 45° into the artificial bone to a depth of 7 mm, without predrilling. The mechanical strengths [insertion torque (IT, resonance frequency (RF, and removal torque (RT] and the anchor area were measured. We hypothesized that no correlation exists among the mechanical forces of each brand. In the 90° tests, the IT, RF, and RT of Type C (8.5 N cm, 10.2 kHz, and 6.1 N cm, respectively were significantly higher than those of Type A (5.0 N cm, 7.7 kHz, and 4.7 N cm, respectively. In the 45° test, the RFs of Type C (9.2 kHz was significantly higher than those of Type A (7.0 kHz and Type B (6.7 kHz. The anchor area of the mini-implants was in the order of Type C (706 mm2>Type B (648 mm2>Type A (621 mm2. Type C exhibited no significant correlation in intragroup comparisons, and the hypothesis was accepted. In the 90° and 45° tests, Type C exhibited the largest anchor area and the highest mechanical strengths (IT, RF, and RT among the three types of mini-implants. The anchor area plays a crucial role in the mechanical strength of mini-implants.

  5. The usefulness of measurement of whole body count in assessing bone marrow metastasis in cancer patients with increased periarticular bone uptake on follow-up bone scan: a comparison with bone marrow scan

    International Nuclear Information System (INIS)

    Jin, Seong Chan; Choi, Yun Young; Cho, Suk Shin

    2003-01-01

    Increased periarticular uptake could be associated with peripheral bone marrow expansion in cancer patients with axial bone marrow metastasis. We compared bone scan and bone marrow scan to investigate whether the increased whole body count in patients with increased periarticular uptake on bone scan is useful in the diagnosis of axial marrow metastasis, and evaluate the role of additional bone marrow scan in these cases. Twelve patients with malignant diseases who showed increased periarticular uptake on bone scan were included. Whole body count was measured on bone scan and it is considered to be increased when the count is more than twice of other patients. Bone marrow scan was taken within 3-7 days. Five hematologic malignancy, 3 stomach cancer, 2 breast cancer, 1 prostate cancer and 1 lung canner were included. All three patients with increased whole body count on bone scan showed axial marrow suppression and peripheral marrow expansion. Eight of 9 patients without increased whole body count showed axial marrow suppression and peripheral marrow expansion. One turned out to be blastic crisis of chronic myelogeneous leukemia, and seven showed normal axial marrow with peripheral marrow expansion in chronic anemia of malignancy. The last one without increased whole body count showed normal bone marrow scan finding. Increased whole body count on bone scan could be a clue to axial bone marrow metastasis in cancer patients with increased periarticular uptake, and bone marrow scan is a valuable method for differential diagnosis in these cases

  6. Ductile sliding between mineral crystals followed by rupture of collagen crosslinks: experimentally supported micromechanical explanation of bone strength.

    Science.gov (United States)

    Fritsch, Andreas; Hellmich, Christian; Dormieux, Luc

    2009-09-21

    There is an ongoing discussion on how bone strength could be explained from its internal structure and composition. Reviewing recent experimental and molecular dynamics studies, we here propose a new vision on bone material failure: mutual ductile sliding of hydroxyapatite mineral crystals along layered water films is followed by rupture of collagen crosslinks. In order to cast this vision into a mathematical form, a multiscale continuum micromechanics theory for upscaling of elastoplastic properties is developed, based on the concept of concentration and influence tensors for eigenstressed microheterogeneous materials. The model reflects bone's hierarchical organization, in terms of representative volume elements for cortical bone, for extravascular and extracellular bone material, for mineralized fibrils and the extrafibrillar space, and for wet collagen. In order to get access to the stress states at the interfaces between crystals, the extrafibrillar mineral is resolved into an infinite amount of cylindrical material phases oriented in all directions in space. The multiscale micromechanics model is shown to be able to satisfactorily predict the strength characteristics of different bones from different species, on the basis of their mineral/collagen content, their intercrystalline, intermolecular, lacunar, and vascular porosities, and the elastic and strength properties of hydroxyapatite and (molecular) collagen.

  7. Bone Geometry, Volumetric Bone Mineral Density, Microarchitecture and Estimated Bone Strength in Caucasian Females with Systemic Lupus Erythematosus. A Cross-Sectional Study Using HR-pQCT

    DEFF Research Database (Denmark)

    Hansen, Stinus; Gudex, Claire; Ahrberg, Fabian

    2014-01-01

    by finite element analysis (FEA) at the distal radius and tibia to assess bone characteristics beyond BMD that may contribute to the increased risk of fracture. Thirty-three Caucasian women with SLE (median age 48, range 21-64 years) and 99 controls (median age 45, range 21-64 years) were studied. Groups.......01), cortical area (-14 %, p TV); -17 %, p ....01], trabecular number (-9 %, p TV (-15 %, p

  8. Bone mineral density (BMD) and computer tomographic measurements of the equine proximal phalanx in correlation with breaking strength.

    Science.gov (United States)

    Tóth, P; Horváth, C; Ferencz, V; Tóth, B; Váradi, A; Szenci, O; Bodó, G

    2013-01-01

    Despite the fact that bone mineral density (BMD) is an important fracture risk predictor in human medicine, studies in equine orthopedic research are still lacking. We hypothesized that BMD correlates with bone failure and fatigue fractures of this bone. Thus, the objectives of this study were to measure the structural and mechanical properties of the proximal phalanx with dual energy X-ray absorptiometry (DXA), to correlate the data obtained from DXA and computer tomography (CT) measurements to those obtained by loading pressure examination and to establish representative region of interest (ROI) for in vitro BMD measurements of the equine proximal phalanx for predicting bone failure force. DXA was used to measure the whole bone BMD and additional three ROI sites in 14 equine proximal phalanges. Following evaluation of the bone density, whole bone, cortical width and area in the mid-diaphyseal plane were measured on CT images. Bones were broken using a manually controlled universal bone crusher to measure bone failure force and reevaluated for the site of fractures on follow-up CT images. Compressive load was applied at a constant displacement rate of 2 mm/min until failure, defined as the first clear drop in the load measurement. The lowest BMD was measured at the trabecular region (mean +/- SD: 1.52 +/- 0.12 g/cm2; median: 1.48 g/cm2; range: 1.38-1.83 g/cm2). There was a significant positive linear correlation between trabelcular BMD and the breaking strength (P = 0.023, r = 0.62). The trabecular region of the proximal phalanx appears to be the only significant indicator of failure of strength in vitro. This finding should be reassessed to further reveal the prognostic value of trabecular BMD in an in vivo fracture risk model.

  9. Bone Geometry, Volumetric Density, Microarchitecture, and Estimated Bone Strength Assessed by HR-pQCT in Adult Patients With Type 1 Diabetes Mellitus

    DEFF Research Database (Denmark)

    Shanbhogue, Vikram V; Hansen, Stinus; Frost, Morten

    2015-01-01

    The primary goal of this cross-sectional in vivo study was to assess peripheral bone microarchitecture, bone strength, and bone remodeling in adult type 1 diabetes (T1D) patients with and without diabetic microvascular disease (MVD+ and MVD-, respectively) and to compare them with age-, gender......-, and height-matched healthy control subjects (CoMVD+ and CoMVD-, respectively). The secondary goal was to assess differences in MVD- and MVD+ patients. Fifty-five patients with T1DM (MVD+ group: n = 29) were recruited from the Funen Diabetes Database. Dual-energy X-ray absorptiometry (DXA), high...... in MVD+ and MVD- groups in comparison to controls, they were similar between the MVD+ and MVD- groups. The results of our study suggest that the presence of MVD was associated with deficits in cortical and trabecular bone vBMD and microarchitecture that could partly explain the excess skeletal fragility...

  10. A study on the compressive and tensile strength of foamed concrete containing pulverized bone as a partial replacement of cement

    International Nuclear Information System (INIS)

    Falade, F.

    2013-01-01

    In this study, structural properties of foamed aerated concrete with and without pulverized bone were investigated. These properties are workability, plastic and testing densities, compressive strength, and tensile strength at the design density of 1600kg/m/sub 3/. The tensile strength was evaluated by subjecting 150 x 150 x750mm unreinforced foamed concrete beams to flexural test and 150x300mm cylinder specimens were subjected to splitting test. 150mm cube specimens were used for the determination of both the compressive strength and the testing density of the foamed aerated concrete. The plastic density was investigated using a container of known volume, and its workability determined using the slump test. The pulverized bone content was varied from 0 to 20% at interval of 5%. The specimens without the pulverized bone served as the control. At the designed density of 1600 kg/m/sub 3/, the results for the control specimens at 28-day curing age are 15.43 and 13.89N/mm/sub 2/ for air-and water-cured specimens respectively. The modulus of rupture and splitting tensile strength are 2.53 and 1.63N/mm/sub 2/ respectively. The results for specimens with pulverized bone did not differ significantly from the specimens without pulverized bone. From the results of this investigation, it can be concluded that foamed aerated concrete used for this study has potential for structural applications. Also pulverized bone can be used to reduce (partially replace) the quantity of cement used in aerated concrete production; thus ridding our environment of potentially harmful wastes, as well as reduce the consumption of non-renewable resources. (author)

  11. Spaceflight-induced vertebral bone loss in ovariectomized rats is associated with increased bone marrow adiposity and no change in bone formation

    Science.gov (United States)

    Keune, Jessica A; Philbrick, Kenneth A; Branscum, Adam J; Iwaniec, Urszula T; Turner, Russell T

    2016-01-01

    There is often a reciprocal relationship between bone marrow adipocytes and osteoblasts, suggesting that marrow adipose tissue (MAT) antagonizes osteoblast differentiation. MAT is increased in rodents during spaceflight but a causal relationship between MAT and bone loss remains unclear. In the present study, we evaluated the effects of a 14-day spaceflight on bone mass, bone resorption, bone formation, and MAT in lumbar vertebrae of ovariectomized (OVX) rats. Twelve-week-old OVX Fischer 344 rats were randomly assigned to a ground control or flight group. Following flight, histological sections of the second lumbar vertebrae (n=11/group) were stained using a technique that allowed simultaneous quantification of cells and preflight fluorochrome label. Compared with ground controls, rats flown in space had 32% lower cancellous bone area and 306% higher MAT. The increased adiposity was due to an increase in adipocyte number (224%) and size (26%). Mineral apposition rate and osteoblast turnover were unchanged during spaceflight. In contrast, resorption of a preflight fluorochrome and osteoclast-lined bone perimeter were increased (16% and 229%, respectively). The present findings indicate that cancellous bone loss in rat lumbar vertebrae during spaceflight is accompanied by increased bone resorption and MAT but no change in bone formation. These findings do not support the hypothesis that increased MAT during spaceflight reduces osteoblast activity or lifespan. However, in the context of ovarian hormone deficiency, bone formation during spaceflight was insufficient to balance increased resorption, indicating defective coupling. The results are therefore consistent with the hypothesis that during spaceflight mesenchymal stem cells are diverted to adipocytes at the expense of forming osteoblasts. PMID:28725730

  12. Bone strength and management of postmenopausal fracture risk with antiresorptive therapies: considerations for women’s health practice

    Directory of Open Access Journals (Sweden)

    Cheung AM

    2016-09-01

    Full Text Available Angela M Cheung,1–3 Heather Frame,4 Michael Ho,5 Erin S Mackinnon,6 Jacques P Brown7 1Department of Medicine, University of Toronto, 2Centre of Excellence in Skeletal Health Assessment, Joint Department of Medical Imaging, University Health Network (UHN, 3Mount Sinai Hospital, University of Toronto, Toronto, ON, 4Assiniboine Clinic, Winnipeg, MB, 5University Health Network, Toronto, 6Amgen Canada, Inc, Mississauga, ON, 7Rheumatology Division, CHU de Québec Research Centre, Laval University, Quebec City, QC, Canada Abstract: Bone strength – and, hence, fracture risk – reflects the structural and material properties of the skeleton, which changes with bone turnover during aging and following effective pharmacotherapy. A variety of powerful new techniques (quantitative computed tomography, as well as peripheral quantitative computed tomography and high-resolution peripheral quantitative computed tomography provide precise images of bone structure and can be used to model the response of specific bones to different types of mechanical load. This review explores the various components of bone strength and the clinical significance of measures, such as bone mineral density, bone turnover markers, and modern imaging data, with regard to fracture risk in women with postmenopausal osteoporosis, before and after initiating antiresorptive therapy. These imaging and related techniques offer an ever-clearer picture of the changes in bone structure and bone mineral metabolism during normal aging and in osteoporosis, as well as in response to treatment. However, because the newer techniques are not yet available in routine practice, validated tools for absolute fracture risk assessment remain essential for clinical decision making. These tools, which are tailored to patient risk data in individual countries, are based on bone mineral density and other readily available clinical data. In addition, bone turnover marker measurements can be useful in

  13. Troglitazone treatment increases bone marrow adipose tissue volume but does not affect trabecular bone volume in mice

    DEFF Research Database (Denmark)

    Erikstrup, Lise Tornvig; Mosekilde, Leif; Justesen, J

    2001-01-01

    proliferator activated receptor-gamma (PPARgamma). Histomorphometric analysis of proximal tibia was performed in order to quantitate the amount of trabecular bone volume per total volume (BV/TV %), adipose tissue volume per total volume (AV/TV %), and hematopoietic marrow volume per total volume (HV......Aging is associated with decreased trabecular bone mass and increased adipocyte formation in bone marrow. As osteoblasts and adipocytes share common precursor cells present in the bone marrow stroma, it has been proposed that an inverse relationship exists between adipocyte and osteoblast....../TV %) using the point-counting technique. Bone size did not differ between the two groups. In troglitazone-treated mice, AV/TV was significantly higher than in control mice (4.7+/-2.1% vs. 0.2+/-0.3%, respectively, mean +/- SD, P

  14. Increased Tensile Strength of Carbon Nanotube Yarns and Sheets through Chemical Modification and Electron Beam Irradiation

    Science.gov (United States)

    Miller, Sandi G.; Williams, Tiffany S.; Baker, James S.; Sola, Francisco; Lebron-Colon, Marisabel; McCorkle, Linda S.; Wilmoth, Nathan G.; Gaier, James; Chen, Michelle; Meador, Michael A.

    2014-01-01

    The inherent strength of individual carbon nanotubes offers considerable opportunity for the development of advanced, lightweight composite structures. Recent work in the fabrication and application of carbon nanotube (CNT) forms such as yarns and sheets has addressed early nanocomposite limitations with respect to nanotube dispersion and loading; and has pushed the technology toward structural composite applications. However, the high tensile strength of an individual CNT has not directly translated to macro-scale CNT forms where bulk material strength is limited by inter-tube electrostatic attraction and slippage. The focus of this work was to assess post processing of CNT sheet and yarn to improve the macro-scale strength of these material forms. Both small molecule functionalization and e-beam irradiation was evaluated as a means to enhance tensile strength and Youngs modulus of the bulk CNT material. Mechanical testing results revealed a tensile strength increase in CNT sheets by 57 when functionalized, while an additional 48 increase in tensile strength was observed when functionalized sheets were irradiated; compared to unfunctionalized sheets. Similarly, small molecule functionalization increased yarn tensile strength up to 25, whereas irradiation of the functionalized yarns pushed the tensile strength to 88 beyond that of the baseline yarn.

  15. Thermomechanical processing of 5083 aluminum to increase strength without increasing susceptibility to stress corrosion cracking

    International Nuclear Information System (INIS)

    Edstrom, C.M.; Blakeslee, J.J.

    1980-01-01

    5083 aluminium with 25% cold work must be processed above 215 0 C or below 70 0 C to avoid forming continuous precipitate in the grain boundaries which makes the material susceptible to stress corrosion cracking. Time at temperature above 215 0 C should be held to minimum (less than 30 min) to retain some strength from the 25% cold work

  16. Evaluation of mechanical strengths of three types of mini-implants in artificial bones.

    Science.gov (United States)

    Tseng, Yu-Chuan; Wu, Ju-Hui; Ting, Chun-Chan; Chen, Hong-Sen; Chen, Chun-Ming

    2017-02-01

    We investigates the effect of the anchor area on the mechanical strengths of infrazygomatic mini-implants. Thirty mini-implants were divided into three types based on the material and shape: Type A (titanium alloy, 2.0×12 mm), Type B (stainless steel, 2.0×12 mm), and Type C (titanium alloy, 2.0×11 mm).The mini-implants were inserted at 90° and 45° into the artificial bone to a depth of 7 mm, without predrilling. The mechanical strengths [insertion torque (IT), resonance frequency (RF), and removal torque (RT)] and the anchor area were measured. We hypothesized that no correlation exists among the mechanical forces of each brand. In the 90° tests, the IT, RF, and RT of Type C (8.5 N cm, 10.2 kHz, and 6.1 N cm, respectively) were significantly higher than those of Type A (5.0 N cm, 7.7 kHz, and 4.7 N cm, respectively). In the 45° test, the RFs of Type C (9.2 kHz) was significantly higher than those of Type A (7.0 kHz) and Type B (6.7 kHz). The anchor area of the mini-implants was in the order of Type C (706 mm 2 )>Type B (648 mm 2 )>Type A (621 mm 2 ). Type C exhibited no significant correlation in intragroup comparisons, and the hypothesis was accepted. In the 90° and 45° tests, Type C exhibited the largest anchor area and the highest mechanical strengths (IT, RF, and RT) among the three types of mini-implants. The anchor area plays a crucial role in the mechanical strength of mini-implants. Copyright © 2016. Published by Elsevier Taiwan.

  17. Mixed-Methods Resistance Training Increases Power and Strength of Young and Older Men.

    Science.gov (United States)

    Newton, Robert U.; Hakkinen, Keijo; Hakkinen, Arja; McCormick, Matt; Volek, Jeff; Kraemer, William J.

    2002-01-01

    Examined the effects of a 10-week, mixed-methods resistance training program on young and older men. Although results confirmed some age-related reductions in muscle strength and power, the older men demonstrated similar capacity to the younger men for increases in muscle strength and power via an appropriate, periodized resistance training…

  18. Bone geometry, volumetric density, microarchitecture, and estimated bone strength assessed by HR-pQCT in Klinefelter syndrome

    DEFF Research Database (Denmark)

    Shanbhogue, Vikram V; Hansen, Stinus; Jørgensen, Niklas Rye

    2014-01-01

    Although the expected skeletal manifestations of testosterone deficiency in Klinefelter's syndrome (KS) are osteopenia and osteoporosis, the structural basis for this is unclear. The aim of this study was to assess bone geometry, volumetric bone mineral density (vBMD), microarchitecture...

  19. Dioxin-like compounds are not associated with bone strength measured by ultrasonography in Inuit women from Nunavik (Canada: results of a cross-sectional study

    Directory of Open Access Journals (Sweden)

    Alexandra-Cristina Paunescu

    2013-05-01

    Full Text Available Background. Bone strength in Inuit people appears lower than that of non-Aboriginals. Inuit are exposed to persistent organic pollutants including dioxin-like compounds (DLCs through their traditional diet that comprises predatory fish and marine mammal fat. Results from experimental and population studies suggest that some DLCs can alter bone metabolism and increase bone fragility. Objective. This cross-sectional descriptive study was conducted to examine the relationship between the stiffness index (SI and plasma concentrations of total DLCs or specific dioxin-like polychlorinated biphenyls (DL-PCBs in Inuit women of Nunavik (Northern Quebec, Canada. Methods. SI was determined by ultrasonography at the right calcaneus of 194 Inuit women aged 35–72 years who participated to Qanuippitaa? How Are We? Nunavik Inuit Health Survey in 2004. Plasma total DLC levels were quantified by measuring the aryl hydrocarbon receptor–mediated transcriptional activity elicited by plasma sample extracts in a cell-based reporter gene assay. Plasma concentrations of DL-PCBs nos. 105, 118, 156, 157, 167 and 189 were measured by gas chromatography–mass spectrometry. We used multiple linear regression analyses to investigate relations between total DLCs or specific DL-PCBs and SI, taking into consideration several potential confounders. Results. Neither total plasma DLCs nor specific DL-PCBs were associated with SI after adjustment for several confounders and covariates. Conclusion. Our results do not support a relation between exposure to DLCs and bone strength measured by ultrasonography in Inuit women of Nunavik.

  20. Dioxin-like compounds are not associated with bone strength measured by ultrasonography in Inuit women from Nunavik (Canada): results of a cross-sectional study.

    Science.gov (United States)

    Paunescu, Alexandra-Cristina; Ayotte, Pierre; Dewailly, Eric; Dodin, Sylvie

    2013-01-01

    Bone strength in Inuit people appears lower than that of non-Aboriginals. Inuit are exposed to persistent organic pollutants including dioxin-like compounds (DLCs) through their traditional diet that comprises predatory fish and marine mammal fat. Results from experimental and population studies suggest that some DLCs can alter bone metabolism and increase bone fragility. This cross-sectional descriptive study was conducted to examine the relationship between the stiffness index (SI) and plasma concentrations of total DLCs or specific dioxin-like polychlorinated biphenyls (DL-PCBs) in Inuit women of Nunavik (Northern Quebec, Canada). SI was determined by ultrasonography at the right calcaneus of 194 Inuit women aged 35-72 years who participated to Qanuippitaa? How Are We? Nunavik Inuit Health Survey in 2004. Plasma total DLC levels were quantified by measuring the aryl hydrocarbon receptor-mediated transcriptional activity elicited by plasma sample extracts in a cell-based reporter gene assay. Plasma concentrations of DL-PCBs nos. 105, 118, 156, 157, 167 and 189 were measured by gas chromatography-mass spectrometry. We used multiple linear regression analyses to investigate relations between total DLCs or specific DL-PCBs and SI, taking into consideration several potential confounders. Neither total plasma DLCs nor specific DL-PCBs were associated with SI after adjustment for several confounders and covariates. Our results do not support a relation between exposure to DLCs and bone strength measured by ultrasonography in Inuit women of Nunavik.

  1. High doses of vitamin C plus E reduce strength training-induced improvements in areal bone mineral density in elderly men.

    Science.gov (United States)

    Stunes, Astrid Kamilla; Syversen, Unni; Berntsen, Sveinung; Paulsen, Gøran; Stea, Tonje H; Hetlelid, Ken J; Lohne-Seiler, Hilde; Mosti, Mats Peder; Bjørnsen, Thomas; Raastad, Truls; Haugeberg, Glenn

    2017-06-01

    Resistance training is beneficial for maintaining bone mass. We aimed to investigate the skeletal effects of high doses of antioxidants [vitamin C + E (α-tocopherol)] supplementation during 12-week supervised strength training in healthy, elderly men METHODS: Design: double-blinded randomized placebo-controlled study. Participants followed a supervised, undulating periodic exercise program with weekly adjusted load: 3 sessions/week and 3-15 repetitions maximum (RM) sets/exercise. The control group (CG, n = 17, 67 ± 5 years) received placebo and the antioxidant group (AO, n = 16, 70 ± 7 years) 1000 mg vitamin C + 235 mg vitamin E, daily. Areal bone mineral density (aBMD) at whole body, lumbar spine (L1-L4), total hip, and femoral neck were measured by dual energy X-ray absorptiometry and muscle strength by 1RM. Serum analyses of bone-related factors and adipokines were performed. In the CG, total hip aBMD increased by 1.0% (CI: 0.3-1.7) versus pretest and lumbar spine aBMD increased by 0.9% (CI: -0.2 to 2.0) compared to the AO. In the CG, there was an increase in serum concentrations of insulin-like growth factor 1 [+27.3% (CI: -0.3 to 54.9)] and leptin [+31.2% (CI: 9.8-52.6)) versus pretest, and a decrease in sclerostin [-9.9% (CI: 4.4-15.3)] versus pretest and versus AO. Serum bone formation markers P1NP and osteocalcin increased in both groups, while the bone resorption marker CTX-1 remained unchanged. High doses of antioxidant supplementations may constrain the favorable skeletal benefits of 12 weeks of resistance exercise in healthy elderly men.

  2. Concepts for increasing gentamicin release from handmade bone cement beads

    NARCIS (Netherlands)

    Rasyid, Hermawan N; van der Mei, Henny C; Frijlink, Henderik W; Soegijoko, Soegijardjo; Van Horn, Jim R; Busscher, Hendrik; Neut, Daniëlle

    2009-01-01

    BACKGROUND AND PURPOSE: Commercial gentamicin-loaded bone cement beads (Septopal) constitute an effective delivery system for local antibiotic therapy. These beads are not available in all parts of the world, and are too expensive for frequent use in others. Thus, orthopedic surgeons worldwide make

  3. Age-related mechanical strength evolution of trabecular bone under fatigue damage for both genders: Fracture risk evaluation.

    Science.gov (United States)

    Ben Kahla, Rabeb; Barkaoui, Abdelwahed; Merzouki, Tarek

    2018-05-04

    Bone tissue is a living composite material, providing mechanical and homeostatic functions, and able to constantly adapt its microstructure to changes in long term loading. This adaptation is conducted by a physiological process, known as "bone remodeling". This latter is manifested by interactions between osteoclasts and osteoblasts, and can be influenced by many local factors, via effects on bone cell differentiation and proliferation. In the current work, age and gender effects on damage rate evolution, throughout life, have been investigated using a mechanobiological finite element modeling. To achieve the aim, a mathematical model has been developed, coupling both cell activities and mechanical behavior of trabecular bone, under cyclic loadings. A series of computational simulations (ABAQUS/UMAT) has been performed on a 3D human proximal femur, allowing to investigate the effects of mechanical and biological parameters on mechanical strength of trabecular bone, in order to evaluate the fracture risk resulting from fatigue damage. The obtained results revealed that mechanical stimulus amplitude affects bone resorption and formation rates, and indicated that age and gender are major factors in bone response to the applied loadings. Copyright © 2018 Elsevier Ltd. All rights reserved.

  4. Axial compressive strength of human vertebrae trabecular bones classified as normal, osteopenic and osteoporotic by quantitative ultrasonometry of calcaneus

    Directory of Open Access Journals (Sweden)

    Reinaldo Cesar

    2017-06-01

    Full Text Available Abstract Introduction Biomechanical assessment of trabecular bone microarchitecture contributes to the evaluation of fractures risk associated with osteoporosis and plays a crucial role in planning preventive strategies. One of the most widely clinical technics used for osteoporosis diagnosis by health professionals is bone dual-energy X-ray absorptiometry (DEXA. However, doubts about its accuracy motivate the introduction of congruent technical analysis such as calcaneal ultrasonometry (Quantitative Ultrasonometry - QUS. Methods Correlations between Bone Quality Index (BQI, determined by calcaneal ultrasonometry of thirty (30 individuals classified as normal, osteopenic and osteoporotic, and elastic modulus (E and ultimate compressive strength (UCS from axial compression tests of ninety (90 proof bodies from human vertebrae trabecular bone, which were extracted from cadavers in the twelfth thoracic region (T12, first and fourth lumbar (L1 and L4. Results Analysis of variance (ANOVA showed significant differences for E (p = 0.001, for UCS (p = 0.0001 and BQI. Spearman’s rank correlation coefficient (rho between BQI and E (r = 0.499 and BQI and UCS (r = 0.508 were moderate. Discussion Calcaneal ultrasonometry technique allowed a moderate estimate of bone mechanical strength and fracture risk associated with osteoporosis in human vertebrae.

  5. Anisotropic Failure Strength of Shale with Increasing Confinement: Behaviors, Factors and Mechanism.

    Science.gov (United States)

    Cheng, Cheng; Li, Xiao; Qian, Haitao

    2017-11-15

    Some studies reported that the anisotropic failure strength of shale will be weakened by increasing confinement. In this paper, it is found that there are various types of anisotropic strength behaviors. Four types of anisotropic strength ratio ( S A 1 ) behaviors and three types of anisotropic strength difference ( S A 2 ) behaviors have been classified based on laboratory experiments on nine groups of different shale samples. The cohesion c w and friction angle ϕ w of the weak planes are proven to be two dominant factors according to a series of bonded-particle discrete element modelling analyses. It is observed that shale is more prone to a slight increase of S A 1 and significant increase of S A 2 with increasing confinement for higher cohesion c w and lower to medium friction angle ϕ w . This study also investigated the mechanism of the anisotropic strength behaviors with increasing confinement. Owing to different contributions of c w and ϕ w under different confinements, different combinations of c w and ϕ w may have various types of influences on the minimum failure strength with the increasing confinement; therefore, different types of anisotropic behaviors occur for different shale specimens as the confinement increases. These findings are very important to understand the stability of wellbore and underground tunneling in the shale rock mass, and should be helpful for further studies on hydraulic fracture propagations in the shale reservoir.

  6. Chronic central administration of Ghrelin increases bone mass through a mechanism independent of appetite regulation.

    Directory of Open Access Journals (Sweden)

    Hyung Jin Choi

    Full Text Available Leptin plays a critical role in the central regulation of bone mass. Ghrelin counteracts leptin. In this study, we investigated the effect of chronic intracerebroventricular administration of ghrelin on bone mass in Sprague-Dawley rats (1.5 μg/day for 21 days. Rats were divided into control, ghrelin ad libitum-fed (ghrelin ad lib-fed, and ghrelin pair-fed groups. Ghrelin intracerebroventricular infusion significantly increased body weight in ghrelin ad lib-fed rats but not in ghrelin pair-fed rats, as compared with control rats. Chronic intracerebroventricular ghrelin infusion significantly increased bone mass in the ghrelin pair-fed group compared with control as indicated by increased bone volume percentage, trabecular thickness, trabecular number and volumetric bone mineral density in tibia trabecular bone. There was no significant difference in trabecular bone mass between the control group and the ghrelin ad-lib fed group. Chronic intracerebroventricular ghrelin infusion significantly increased the mineral apposition rate in the ghrelin pair-fed group as compared with control. In conclusion, chronic central administration of ghrelin increases bone mass through a mechanism that is independent of body weight, suggesting that ghrelin may have a bone anabolic effect through the central nervous system.

  7. Eldecalcitol improves mechanical strength of cortical bones by stimulating the periosteal bone formation in the senescence-accelerated SAM/P6 mice - a comparison with alfacalcidol.

    Science.gov (United States)

    Shiraishi, Ayako; Sakai, Sadaoki; Saito, Hitoshi; Takahashi, Fumiaki

    2014-10-01

    Eldecalcitol (ELD), a 2β-hydroxypropyloxy derivative of 1α,25(OH)2D3, is a potent inhibitor of bone resorption that has demonstrated a greater effect at reducing the risk of fracture in osteoporotic patients than alfacalcidol (ALF). In the present study, we used the senescence-accelerated mouse strain P6 (SAM/P6), which has low bone mass caused by osteoblast dysfunction, to evaluate the effect of ELD on cortical bone in comparison with ALF. Four-month-old SAM/P6 mice were given either ELD (0.025 or 0.05μg/kg) or ALF (0.2 or 0.4μg/kg) by oral gavage 5 times/week for 6 weeks. Both ELD and ALF increased serum calcium (Ca) in a dose-dependent manner. Serum Ca levels in the ELD 0.05μg/kg group were comparable to those of the ALF 0.2μg/kg group. ELD 0.05μg/kg significantly improved the bone biomechanical properties of the femur compared with the vehicle control group (pBone histomorphometry revealed that in the femoral endocortical surface, the suppression of bone resorption parameters (N.Oc/BS) and bone formation parameters (MS/BS) by ELD (0.05μg/kg) was greater than that by ALF (0.2μg/kg). In contrast, in the femoral periosteal surface, ELD 0.05μg/kg significantly increased bone formation parameters (BFR/BS, MS/BS) compared with the vehicle control group (pbone not only by inhibiting endocortical bone resorption but also by stimulating the periosteal bone formation in SAM/P6 mice. This article is part of a Special Issue entitled '16th Vitamin D Workshop'. Copyright © 2013 Elsevier Ltd. All rights reserved.

  8. Laterality and grip strength influence hand bone micro-architecture in modern humans, an HRpQCT study.

    Science.gov (United States)

    Reina, Nicolas; Cavaignac, Etienne; Trousdale, William H; Laffosse, Jean-Michel; Braga, José

    2017-06-01

    It is widely hypothesized that mechanical loading, specifically repetitive low-intensity tasks, influences the inner structure of cancellous bone. As such, there is likely a relationship between handedness and bone morphology. The aim of this study is to determine patterns in trabecular bone between dominant and non-dominant hands in modern humans. Seventeen healthy patients between 22 and 32 years old were included in the study. Radial carpal bones (lunate, capitate, scaphoid, trapezium, trapezoid, 1st, 2nd and 3rd metacarpals) were analyzed with high-resolution micro-computed tomography. Additionally, crush and pinch grip were recorded. Factorial analysis indicated that bone volume ratio, trabeculae number (Tb.N), bone surface to volume ratio (BS.BV), body weight, stature and crush grip were all positively correlated with principal components 1 and 2 explaining 78.7% of the variance. Volumetric and trabecular endostructural parameters (BV/TV, BS/BV or Tb.Th, Tb.N) explain the observed inter-individual variability better than anthropometric or clinical parameters. Factors analysis regressions showed correlations between these parameters and the dominant side for crush strength for the lunate (r 2 = 0.640, P modern human wrist. © 2017 Anatomical Society.

  9. The Impact of Fat and Obesity on Bone Microarchitecture and Strength in Children.

    Science.gov (United States)

    Farr, Joshua N; Dimitri, Paul

    2017-05-01

    A complex interplay of genetic, environmental, hormonal, and behavioral factors affect skeletal development, several of which are associated with childhood fractures. Given the rise in obesity worldwide, it is of particular concern that excess fat accumulation during childhood appears to be a risk factor for fractures. Plausible explanations for this higher fracture risk include a greater propensity for falls, greater force generation upon fall impact, unhealthy lifestyle habits, and excessive adipose tissue that may have direct or indirect detrimental effects on skeletal development. To date, there remains little resolution or agreement about the impact of obesity and adiposity on skeletal development as well as the mechanisms underpinning these changes. Limitations of imaging modalities, short duration of follow-up in longitudinal studies, and differences among cohorts examined may all contribute to conflicting results. Nonetheless, a linear relationship between increasing adiposity and skeletal development seems unlikely. Fat mass may confer advantages to the developing cortical and trabecular bone compartments, provided that gains in fat mass are not excessive. However, when fat mass accumulation reaches excessive levels, unfavorable metabolic changes may impede skeletal development. Mechanisms underpinning these changes may relate to changes in the hormonal milieu, with adipokines potentially playing a central role, but again findings have been confounding. Changes in the relationship between fat and bone also appear to be age and sex dependent. Clearly, more work is needed to better understand the controversial impact of fat and obesity on skeletal development and fracture risk during childhood.

  10. A new stable GIP-Oxyntomodulin hybrid peptide improved bone strength both at the organ and tissue levels in genetically-inherited type 2 diabetes mellitus.

    Science.gov (United States)

    Mansur, Sity Aishah; Mieczkowska, Aleksandra; Flatt, Peter R; Bouvard, Beatrice; Chappard, Daniel; Irwin, Nigel; Mabilleau, Guillaume

    2016-06-01

    Obesity and type 2 diabetes mellitus (T2DM) progress worldwide with detrimental effects on several physiological systems including bone tissue mainly by affecting bone quality. Several gut hormones analogues have been proven potent in ameliorating bone quality. In the present study, we used the leptin receptor-deficient db/db mice as a model of obesity and severe T2DM to assess the extent of bone quality alterations at the organ and tissue levels. We also examined the beneficial effects of gut hormone therapy in this model by using a new triple agonist ([d-Ala(2)]GIP-Oxm) active at the GIP, GLP-1 and glucagon receptors. As expected, db/db mice presented with dramatic alterations of bone strength at the organ level associated with deterioration of trabecular and cortical microarchitectures and an augmentation in osteoclast numbers. At the tissue level, these animals presented also with alterations of bone strength (reduced hardness, indentation modulus and dissipated energy) with modifications of tissue mineral distribution, collagen glycation and collagen maturity. The use of [d-Ala(2)]GIP-Oxm considerably improved bone strength at the organ level with modest effects on trabecular microarchitecture. At the tissue level, [d-Ala(2)]GIP-Oxm ameliorated bone strength reductions with positive effects on collagen glycation and collagen maturity. This study provides support for including gut hormone analogues as possible new therapeutic strategies for improving bone quality in bone complications associated to T2DM. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. Self-assembled high-strength hydroxyapatite/graphene oxide/chitosan composite hydrogel for bone tissue engineering.

    Science.gov (United States)

    Yu, Peng; Bao, Rui-Ying; Shi, Xiao-Jun; Yang, Wei; Yang, Ming-Bo

    2017-01-02

    Graphene hydrogel has shown greatly potentials in bone tissue engineering recently, but it is relatively weak in the practical use. Here we report a facile method to synthesize high strength composite graphene hydrogel. Graphene oxide (GO), hydroxyapatite (HA) nanoparticles (NPs) and chitosan (CS) self-assemble into a 3-dimensional hydrogel with the assistance of crosslinking agent genipin (GNP) for CS and reducing agent sodium ascorbate (NaVC) for GO simultaneously. The dense and oriented microstructure of the resulted composite gel endows it with high mechanical strength, high fixing capacity of HA and high porosity. These properties together with the good biocompatibility make the ternary composite gel a promising material for bone tissue engineering. Such a simultaneous crosslinking and reduction strategy can also be applied to produce a variety of 3D graphene-polymer based nanocomposites for biomaterials, energy storage materials and adsorbent materials. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Increases in bone density during treatment of men with idiopathic hypogonadotropic hypogonadism

    Energy Technology Data Exchange (ETDEWEB)

    Finkelstein, J.S.; Klibanski, A.; Neer, R.M.; Doppelt, S.H.; Rosenthal, D.I.; Segre, G.V.; Crowley, W.F. Jr. (Massachusetts General Hospital, Boston (USA))

    1989-10-01

    To assess the effects of gonadal steroid replacement on bone density in men with osteoporosis due to severe hypogonadism, we measured cortical bone density in the distal radius by 125I photon absorptiometry and trabecular bone density in the lumbar spine by quantitative computed tomography in 21 men with isolated GnRH deficiency while serum testosterone levels were maintained in the normal adult male range for 12-31 months (mean +/- SE, 23.7 +/- 1.1). In men who initially had fused epiphyses (n = 15), cortical bone density increased from 0.71 +/- 0.02 to 0.74 +/- 0.01 g/cm2 (P less than 0.01), while trabecular bone density did not change (116 +/- 9 compared with 119 +/- 7 mg/cm3). In men who initially had open epiphyses (n = 6), cortical bone density increased from 0.62 +/- 0.01 to 0.70 +/- 0.03 g/cm2 (P less than 0.01), while trabecular bone density increased from 96 +/- 13 to 109 +/- 12 mg/cm3 (P less than 0.01). Cortical bone density increased 0.03 +/- 0.01 g/cm2 in men with fused epiphyses and 0.08 +/- 0.02 g/cm2 in men with open epiphyses (P less than 0.05). Despite these increases, neither cortical nor trabecular bone density returned to normal levels. Histomorphometric analyses of iliac crest bone biopsies demonstrated that most of the men had low turnover osteoporosis, although some men had normal to high turnover osteoporosis. We conclude that bone density increases during gonadal steroid replacement of GnRH-deficient men, particularly in men who are skeletally immature.

  13. Increases in bone density during treatment of men with idiopathic hypogonadotropic hypogonadism

    International Nuclear Information System (INIS)

    Finkelstein, J.S.; Klibanski, A.; Neer, R.M.; Doppelt, S.H.; Rosenthal, D.I.; Segre, G.V.; Crowley, W.F. Jr.

    1989-01-01

    To assess the effects of gonadal steroid replacement on bone density in men with osteoporosis due to severe hypogonadism, we measured cortical bone density in the distal radius by 125I photon absorptiometry and trabecular bone density in the lumbar spine by quantitative computed tomography in 21 men with isolated GnRH deficiency while serum testosterone levels were maintained in the normal adult male range for 12-31 months (mean +/- SE, 23.7 +/- 1.1). In men who initially had fused epiphyses (n = 15), cortical bone density increased from 0.71 +/- 0.02 to 0.74 +/- 0.01 g/cm2 (P less than 0.01), while trabecular bone density did not change (116 +/- 9 compared with 119 +/- 7 mg/cm3). In men who initially had open epiphyses (n = 6), cortical bone density increased from 0.62 +/- 0.01 to 0.70 +/- 0.03 g/cm2 (P less than 0.01), while trabecular bone density increased from 96 +/- 13 to 109 +/- 12 mg/cm3 (P less than 0.01). Cortical bone density increased 0.03 +/- 0.01 g/cm2 in men with fused epiphyses and 0.08 +/- 0.02 g/cm2 in men with open epiphyses (P less than 0.05). Despite these increases, neither cortical nor trabecular bone density returned to normal levels. Histomorphometric analyses of iliac crest bone biopsies demonstrated that most of the men had low turnover osteoporosis, although some men had normal to high turnover osteoporosis. We conclude that bone density increases during gonadal steroid replacement of GnRH-deficient men, particularly in men who are skeletally immature

  14. Osteogenic protein 1 device increases bone formation and bone graft resorption around cementless implants

    DEFF Research Database (Denmark)

    Jensen, Thomas B; Overgaard, Søren; Lind, Martin

    2002-01-01

    In each femoral condyle of 8 Labrador dogs, a non weight-bearing hydroxyapatite-coated implant was inserted surrounded by a 3 mm gap. Each gap was filled with bone allograft or ProOsteon with or without OP-1 delivered in a bovine collagen type I carrier (OP-1 device). 300 microg OP-1 was used...

  15. Masculinity in the Making: Men’s Increased Consumption of Strength Training

    OpenAIRE

    Sherlock, Roger; Freeman, Olivia; Dunne, Andrew

    2005-01-01

    This paper explores the relationship between the body, masculinity and the consumption of body-focussed activities. It examines the meaning and importance of strength training for men. Strength training is of interest because its increase in popularity is occurring at a particular point in time when a growing number of men are experiencing insecurities over their masculine identities as a result of recent socioeconomic changes. This paper proposes that men today are facing a dilemma in terms ...

  16. Using Anisotropic 3D Minkowski Functionals for Trabecular Bone Characterization and Biomechanical Strength Prediction in Proximal Femur Specimens

    Science.gov (United States)

    Nagarajan, Mahesh B.; De, Titas; Lochmüller, Eva-Maria; Eckstein, Felix; Wismüller, Axel

    2017-01-01

    The ability of Anisotropic Minkowski Functionals (AMFs) to capture local anisotropy while evaluating topological properties of the underlying gray-level structures has been previously demonstrated. We evaluate the ability of this approach to characterize local structure properties of trabecular bone micro-architecture in ex vivo proximal femur specimens, as visualized on multi-detector CT, for purposes of biomechanical bone strength prediction. To this end, volumetric AMFs were computed locally for each voxel of volumes of interest (VOI) extracted from the femoral head of 146 specimens. The local anisotropy captured by such AMFs was quantified using a fractional anisotropy measure; the magnitude and direction of anisotropy at every pixel was stored in histograms that served as a feature vectors that characterized the VOIs. A linear multi-regression analysis algorithm was used to predict the failure load (FL) from the feature sets; the predicted FL was compared to the true FL determined through biomechanical testing. The prediction performance was measured by the root mean square error (RMSE) for each feature set. The best prediction performance was obtained from the fractional anisotropy histogram of AMF Euler Characteristic (RMSE = 1.01 ± 0.13), which was significantly better than MDCT-derived mean BMD (RMSE = 1.12 ± 0.16, p<0.05). We conclude that such anisotropic Minkowski Functionals can capture valuable information regarding regional trabecular bone quality and contribute to improved bone strength prediction, which is important for improving the clinical assessment of osteoporotic fracture risk. PMID:29170581

  17. Rapid-throughput skeletal phenotyping of 100 knockout mice identifies 9 new genes that determine bone strength.

    Directory of Open Access Journals (Sweden)

    J H Duncan Bassett

    Full Text Available Osteoporosis is a common polygenic disease and global healthcare priority but its genetic basis remains largely unknown. We report a high-throughput multi-parameter phenotype screen to identify functionally significant skeletal phenotypes in mice generated by the Wellcome Trust Sanger Institute Mouse Genetics Project and discover novel genes that may be involved in the pathogenesis of osteoporosis. The integrated use of primary phenotype data with quantitative x-ray microradiography, micro-computed tomography, statistical approaches and biomechanical testing in 100 unselected knockout mouse strains identified nine new genetic determinants of bone mass and strength. These nine new genes include five whose deletion results in low bone mass and four whose deletion results in high bone mass. None of the nine genes have been implicated previously in skeletal disorders and detailed analysis of the biomechanical consequences of their deletion revealed a novel functional classification of bone structure and strength. The organ-specific and disease-focused strategy described in this study can be applied to any biological system or tractable polygenic disease, thus providing a general basis to define gene function in a system-specific manner. Application of the approach to diseases affecting other physiological systems will help to realize the full potential of the International Mouse Phenotyping Consortium.

  18. Cases of diffusely increased 18F FDG uptake in bone marrow

    International Nuclear Information System (INIS)

    Suga, Kazuyoshi; Kawakami, Yasuhiko; Matsunaga, Naofumi

    2009-01-01

    A whole body imaging of 18 F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/CT provides assessment of FDG uptake in bone marrow and other systemic organs. Diffuse increase of FDG uptake in bone marrow can be associated with leukocytosis, infection, anemia, administration of granulocyte-colony stimulating factor or erythropoietin. and cytokine-producing neoplasms and myeloproliferative syndromes, and etc, and this finding can be an important sign indicative of hyper-metabolism in hemopoietic tissue associated by various etiology. Diffuse increase of FDG uptake in bone marrow affect on FDG uptake in other organs or primary lesions, and must be differentiated from diffuse bone marrow involvement of malignant tumors. In this paper, we report cases of diffuse increase of FDG uptake in bone marrow experienced in our hospital, and discuss the mechanisms and diagnostic importance of this finding, by referring to the published literatures. (author)

  19. The influence of chromosome density variations on the increase in nuclear disorder strength in carcinogenesis

    International Nuclear Information System (INIS)

    Kim, Jun Soo; Pradhan, Prabhakar; Backman, Vadim; Szleifer, Igal

    2011-01-01

    Microscopic structural changes have long been observed in cancer cells and used as a marker in cancer diagnosis. Recent development of an optical technique, partial-wave spectroscopy (PWS), enabled more sensitive detection of nanoscale structural changes in early carcinogenesis in terms of the disorder strength related to density variations. These nanoscale alterations precede the well-known microscopic morphological changes. We investigate the influence of nuclear density variations due to chromosome condensation on changes of disorder strength by computer simulations of model chromosomes. Nuclear configurations with different degrees of chromosome condensation are realized from simulations of decondensing chromosomes and the disorder strength is calculated for these nuclear configurations. We found that the disorder strength increases significantly for configurations with slightly more condensed chromosomes. Coupled with PWS measurements, the simulation results suggest that the chromosome condensation and the resulting spatial density inhomogeneity may represent one of the earliest events in carcinogenesis

  20. Prediction of femoral neck and spine bone mineral content from the BMC of the radius or ulna and the relationship between bone strength and BMC

    Science.gov (United States)

    Wilson, C. R.

    1974-01-01

    The bone mineral content (BMC) is extensively used to provide information about the status of an entire skeleton. Changes in BMC are employed to evaluate the effect of various drugs, disease states, weightlessness, exercise, renal dialysis and others on the skeleton. Clinical and functional information is discussed that may be derived from the BMC of a limited region of the skeleton. In particular there is a fairly high degree of correlation between the BMC of the radius or ulna and that of the femoral neck, r about 0.85 and a somewhat lower relationship between the BMC of the radius or ulna and the thoracic vertebrae, r about 0.65. Also the BMC is highly related to the strength of bone at that scan site.

  1. A 21-Week Bone Deposition Promoting Exercise Programme Increases Bone Mass in Young People with Down Syndrome

    Science.gov (United States)

    Gonzalez-Aguero, Alejandro; Vicente-Rodriguez, German; Gomez-Cabello, Alba; Ara, Ignacio; Moreno, Luis A.; Casajus, Jose A.

    2012-01-01

    Aim: To determine whether the bone mass of young people with Down syndrome may increase, following a 21-week conditioning training programme including plyometric jumps. Method: Twenty-eight participants with Down syndrome (13 females, 15 males) aged 10 to 19 years were divided into exercise (DS-E; n = 14; eight females, six males mean age 13y 8mo,…

  2. Strength Training Decreases Inflammation and Increases Cognition and Physical Fitness in Older Women with Cognitive Impairment.

    Science.gov (United States)

    Chupel, Matheus U; Direito, Fábio; Furtado, Guilherme E; Minuzzi, Luciéle G; Pedrosa, Filipa M; Colado, Juan C; Ferreira, José P; Filaire, Edith; Teixeira, Ana M

    2017-01-01

    Introduction: Cognitive impairment that affects older adults is commonly associated with an inflammatory imbalance, resulting in decreased physical fitness. Exercise has been pointed to mitigate immunosenescence and cognitive impairment associated with aging, while increase in physical fitness. However, few studies explored the relationship between changes in cytokine concentration and improvement on cognition due to elastic band strength training. The aim of this study was to investigate the effects of strength training on pro-and anti-inflammatory cytokines, hematological markers and physical fitness of older women with cognitive impairment. Methods: Thirty-three women (82.7 ± 5.7 years old) participated in the study and were divided in two groups: strength exercise training group (ST; n = 16) and Control Group (CG; n = 17) and were evaluated before and after 28 weeks of the exercise program. The CG did not undergo any type of exercise programs. Data for IL-10, TNF-α, IFN-γ, C-Reactive Protein (CRP), white blood counts (WBC), red blood counts (RBC), Mini Mental State Examination (MMSE) and physical fitness tests were analyzed in both moments. Results: IL-10 increased in the ST group without changes in CG. TNF-α and CRP increased in the control group while no changes were observed for IFN-γ in both groups. Strength training decreased leukocyte and lymphocyte counts and increase hemoglobin, mean cell volume and mean cell hemoglobin concentration. The MMSE score increased in strength training group but remained unchanged in the control group. A correlation between the variation of granulocyte counts and the MMSE scores was also observed within the total sample. An improvement in physical fitness was observed with strength training. Conclusion: Resistance exercise promoted better anti-inflammatory balance and physical performance simultaneously with an increase in cognitive profile in older women with cognitive impairment.

  3. Fat Mass Is Positively Associated with Estimated Hip Bone Strength among Chinese Men Aged 50 Years and above with Low Levels of Lean Mass

    Directory of Open Access Journals (Sweden)

    Guiyuan Han

    2017-04-01

    Full Text Available This study investigated the relationships of fat mass (FM and lean mass (LM with estimated hip bone strength in Chinese men aged 50–80 years (median value: 62.0 years. A cross-sectional study including 889 men was conducted in Guangzhou, China. Body composition and hip bone parameters were generated by dual-energy X-ray absorptiometry (DXA. The relationships of the LM index (LMI and the FM index (FMI with bone phenotypes were detected by generalised additive models and multiple linear regression. The associations between the FMI and the bone variables in LMI tertiles were further analysed. The FMI possessed a linear relationship with greater estimated hip bone strength after adjustment for the potential confounders (p < 0.05. Linear relationships were also observed for the LMI with most bone phenotypes, except for the cross-sectional area (p < 0.05. The contribution of the LMI (4.0%–12.8% was greater than that of the FMI (2.0%–5.7%. The associations between the FMI and bone phenotypes became weaker after controlling for LMI. Further analyses showed that estimated bone strength ascended with FMI in the lowest LMI tertile (p < 0.05, but not in the subgroups with a higher LMI. This study suggested that LM played a critical role in bone health in middle-aged and elderly Chinese men, and that the maintenance of adequate FM could help to promote bone acquisition in relatively thin men.

  4. The increase of compressive strength of natural polymer modified concrete with Moringa oleifera

    Science.gov (United States)

    Susilorini, Rr. M. I. Retno; Santosa, Budi; Rejeki, V. G. Sri; Riangsari, M. F. Devita; Hananta, Yan's. Dianaga

    2017-03-01

    Polymer modified concrete is one of some concrete technology innovations to meet the need of strong and durable concrete. Previous research found that Moringa oleifera can be applied as natural polymer modifiers into mortars. Natural polymer modified mortar using Moringa oleifera is proven to increase their compressive strength significantly. In this resesearch, Moringa oleifera seeds have been grinded and added into concrete mix for natural polymer modified concrete, based on the optimum composition of previous research. The research investigated the increase of compressive strength of polymer modified concrete with Moringa oleifera as natural polymer modifiers. There were 3 compositions of natural polymer modified concrete with Moringa oleifera referred to previous research optimum compositions. Several cylinder of 10 cm x 20 cm specimens were produced and tested for compressive strength at age 7, 14, and, 28 days. The research meets conclusions: (1) Natural polymer modified concrete with Moringa oleifera, with and without skin, has higher compressive strength compared to natural polymer modified mortar with Moringa oleifera and also control specimens; (2) Natural polymer modified concrete with Moringa oleifera without skin is achieved by specimens contains Moringa oleifera that is 0.2% of cement weight; and (3) The compressive strength increase of natural polymer modified concrete with Moringa oleifera without skin is about 168.11-221.29% compared to control specimens

  5. Effect of tocotrienol from Bixa orellana (annatto on bone microstructure, calcium content, and biomechanical strength in a model of male osteoporosis induced by buserelin

    Directory of Open Access Journals (Sweden)

    Mohamad NV

    2018-03-01

    Full Text Available Nur-Vaizura Mohamad, Soelaiman Ima-Nirwana, Kok-Yong Chin Department of Pharmacology, Faculty of Medicine, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia Background: Patients receiving androgen deprivation therapy experience secondary hypogonadism, associated bone loss, and increased fracture risk. It has been shown that tocotrienol from Bixa orellana (annatto prevents skeletal microstructural changes in rats experiencing primary hypogonadism. However, its potential in preventing bone loss due to androgen deprivation therapy has not been tested. This study aimed to evaluate the skeletal protective effects of annatto tocotrienol using a buserelin-induced osteoporotic rat model. Methods: Forty-six male Sprague Dawley rats aged 3 months were randomized into six groups. The baseline control (n=6 was sacrificed at the onset of the study. The normal control (n=8 received corn oil (the vehicle of tocotrienol orally daily and normal saline (the vehicle of buserelin subcutaneously daily. The buserelin control (n=8 received corn oil orally daily and subcutaneous buserelin injection (75 µg/kg daily. The calcium control (n=8 was supplemented with 1% calcium in drinking water and daily subcutaneous buserelin injection (75 µg/kg. The remaining rats were given daily oral annatto tocotrienol at 60 mg/kg (n=8 or 100 mg/kg (n=8 plus daily subcutaneous buserelin injection (75 µg/kg (n=8. At the end of the experiment, the rats were euthanized and their blood, tibia, and femur were harvested. Structural changes of the tibial trabecular and cortical bone were examined using X-ray micro-computed tomography. Femoral bone calcium content and biomechanical strength were also evaluated. Results: Annatto tocotrienol at 60 and 100 mg/kg significantly prevented the deterioration of trabecular bone and cortical thickness in buserelin-treated rats (P<0.05. Both doses of annatto tocotrienol also improved femoral biomechanical strength and bone calcium content

  6. Fat Mass Is Positively Associated with Estimated Hip Bone Strength among Chinese Men Aged 50 Years and above with Low Levels of Lean Mass.

    Science.gov (United States)

    Han, Guiyuan; Chen, Yu-Ming; Huang, Hua; Chen, Zhanyong; Jing, Lipeng; Xiao, Su-Mei

    2017-04-24

    This study investigated the relationships of fat mass (FM) and lean mass (LM) with estimated hip bone strength in Chinese men aged 50-80 years (median value: 62.0 years). A cross-sectional study including 889 men was conducted in Guangzhou, China. Body composition and hip bone parameters were generated by dual-energy X-ray absorptiometry (DXA). The relationships of the LM index (LMI) and the FM index (FMI) with bone phenotypes were detected by generalised additive models and multiple linear regression. The associations between the FMI and the bone variables in LMI tertiles were further analysed. The FMI possessed a linear relationship with greater estimated hip bone strength after adjustment for the potential confounders ( p maintenance of adequate FM could help to promote bone acquisition in relatively thin men.

  7. RANGE OF MOTION EXERCISE OF ARMS INCREASES THE MUCLE STRENGTH FOR POST STROKE PATIENTS

    Directory of Open Access Journals (Sweden)

    Judi Nurbaeni

    2017-04-01

    Full Text Available Introduction: Someone attached by stroke can’t do their activity fluently because stroke can cause the weakness of motor and sensor function. This condition cause physical defect and give effect in social and economic too, because someone who suffered stroke usually still in productive age. The objective of this study was to examine the effect of arm range of motion in the muscle strength of post stroke patient. Method: Pre experimental pre–post test design was used in this study. Population of this study was post stroke patient in Wijayakusuma ward dr. Soedono Hospital and total samples were 11 respondents. Independent variable was arm range of motion exercise, dependent variable was strength of arm muscle. Data were collected by observation with manual muscle testing of Lovelt, Naniel and Worthinghom and then analyzed using wilcoxon signed rank test with signi fi cant level of α ≤ 0.05. Result: The result showed that 11 respondents had increased their strength of muscle (p = 0.04. Discussion: It can be concluded that the strength of muscle increased after get arm range of motion exercise. When range of motion had been done Ca+ will be activated by cell so that happen integrity of muscle protein. If Ca+ and troponin had been activated, actin and myosin would have been defensed, so that can moved the skeletal and followed by muscle contraction, expand, outgrow and had a tonus. This condition can showed the strength of muscle.

  8. Increasing FSW join strength by optimizing feed rate, rotating speed and pin angle

    Science.gov (United States)

    Darmadi, Djarot B.; Purnowidodo, Anindito; Siswanto, Eko

    2017-10-01

    Principally the join in Friction Stir Welding (FSW) is formed due to mechanical bonding. At least there are two factors determines the quality of this join, first is the temperature in the area around the interface and secondly the intense of mixing forces in nugget zone to create the mechanical bonding. The adequate temperature creates good flowability of the nugget zone and an intensive mixing force produces homogeneous strong bonding. Based on those two factors in this research the effects of feed rate, rotating speed and pin angle of the FSW process to the tensile strength of resulted join are studied. The true experimental method was used. Feed rate was varied at 24, 42, 55 and 74 mm/minutes and from the experimental results, it can be concluded that the higher feed rate decreases the tensile strength of weld join and it is believed due to the lower heat embedded in the material. Inversely, the higher rotating speed increases the join’s tensile strength as a result of higher heat embedded in base metal and higher mixing force in the nugget zone. The rotating speed were 1842, 2257 and 2904 RPMs. The pin angle determines the direction of mixing force. With variation of pin angle: 0°, 4°, 8° and 12° the higher pin angle generally increases the tensile strength because of more intensive mixing force. For 12° pin angle the lower tensile strength is found since the force tends to push out the nugget area from the joint gap.

  9. Implants delivering bisphosphonate locally increase periprosthetic bone density in an osteoporotic sheep model. A pilot study

    Directory of Open Access Journals (Sweden)

    GVA Stadelmann

    2008-07-01

    Full Text Available It is a clinical challenge to obtain a sufficient orthopaedic implant fixation in weak osteoporotic bone. When the primary implant fixation is poor, micromotions occur at the bone-implant interface, activating osteoclasts, which leads to implant loosening. Bisphosphonate can be used to prevent the osteoclastic response, but when administered systemically its bioavailability is low and the time it takes for the drug to reach the periprosthetic bone may be a limiting factor. Recent data has shown that delivering bisphosphonate locally from the implant surface could be an interesting solution. Local bisphosphonate delivery increased periprosthetic bone density, which leads to a stronger implant fixation, as demonstrated in rats by the increased implant pullout force. The aim of the present study was to verify the positive effect on periprosthetic bone remodelling of local bisphosphonate delivery in an osteoporotic sheep model. Four implants coated with zoledronate and two control implants were inserted in the femoral condyle of ovariectomized sheep for 4 weeks. The bone at the implant surface was 50% higher in the zoledronate-group compared to control group. This effect was significant up to a distance of 400µm from the implant surface. The presented results are similar to what was observed in the osteoporotic rat model, which suggest that the concept of releasing zoledronate locally from the implant to increase the implant fixation is not species specific. The results of this trial study support the claim that local zoledronate could increase the fixation of an implant in weak bone.

  10. Bone inner structure suggests increasing aquatic adaptations in Desmostylia (Mammalia, Afrotheria.

    Directory of Open Access Journals (Sweden)

    Shoji Hayashi

    Full Text Available The paleoecology of desmostylians has been discussed controversially with a general consensus that desmostylians were aquatic or semi-aquatic to some extent. Bone microanatomy can be used as a powerful tool to infer habitat preference of extinct animals. However, bone microanatomical studies of desmostylians are extremely scarce.We analyzed the histology and microanatomy of several desmostylians using thin-sections and CT scans of ribs, humeri, femora and vertebrae. Comparisons with extant mammals allowed us to better understand the mode of life and evolutionary history of these taxa. Desmostylian ribs and long bones generally lack a medullary cavity. This trait has been interpreted as an aquatic adaptation among amniotes. Behemotops and Paleoparadoxia show osteosclerosis (i.e. increase in bone compactness, and Ashoroa pachyosteosclerosis (i.e. combined increase in bone volume and compactness. Conversely, Desmostylus differs from these desmostylians in displaying an osteoporotic-like pattern.In living taxa, bone mass increase provides hydrostatic buoyancy and body trim control suitable for poorly efficient swimmers, while wholly spongy bones are associated with hydrodynamic buoyancy control in active swimmers. Our study suggests that all desmostylians had achieved an essentially, if not exclusively, aquatic lifestyle. Behemotops, Paleoparadoxia and Ashoroa are interpreted as shallow water swimmers, either hovering slowly at a preferred depth, or walking on the bottom, and Desmostylus as a more active swimmer with a peculiar habitat and feeding strategy within Desmostylia. Therefore, desmostylians are, with cetaceans, the second mammal group showing a shift from bone mass increase to a spongy inner organization of bones in their evolutionary history.

  11. Semantic priming increases word frequency judgments: Evidence for the role of memory strength in frequency estimation.

    Science.gov (United States)

    Woltz, Dan J; Gardner, Michael K

    2015-09-01

    Previous research has demonstrated a systematic, nonlinear relationship between word frequency judgments and values from word frequency norms. This relationship could reflect a perceptual process similar to that found in the psychophysics literature for a variety of sensory phenomena. Alternatively, it could reflect memory strength differences that are expected for words of varying levels of prior exposure. Two experiments tested the memory strength explanation by semantically priming words prior to frequency judgments. Exposure to related word meanings produced a small but measurable increase in target word frequency ratings. Repetition but not semantic priming had a greater impact on low compared to high frequency words. These findings are consistent with a memory strength view of frequency judgments that assumes a distributed network with lexical and semantic levels of representation. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Comparison of the Pullout Strength of Different Pedicle Screw Designs and Augmentation Techniques in an Osteoporotic Bone Model.

    Science.gov (United States)

    Kiyak, Gorkem; Balikci, Tevfik; Heydar, Ahmed Majid; Bezer, Murat

    2018-02-01

    Mechanical study. To compare the pullout strength of different screw designs and augmentation techniques in an osteoporotic bone model. Adequate bone screw pullout strength is a common problem among osteoporotic patients. Various screw designs and augmentation techniques have been developed to improve the biomechanical characteristics of the bone-screw interface. Polyurethane blocks were used to mimic human osteoporotic cancellous bone, and six different screw designs were tested. Five standard and expandable screws without augmentation, eight expandable screws with polymethylmethacrylate (PMMA) or calcium phosphate augmentation, and distal cannulated screws with PMMA and calcium phosphate augmentation were tested. Mechanical tests were performed on 10 unused new screws of each group. Screws with or without augmentation were inserted in a block that was held in a fixture frame, and a longitudinal extraction force was applied to the screw head at a loading rate of 5 mm/min. Maximum load was recorded in a load displacement curve. The peak pullout force of all tested screws with or without augmentation was significantly greater than that of the standard pedicle screw. The greatest pullout force was observed with 40-mm expandable pedicle screws with four fins and PMMA augmentation. Augmented distal cannulated screws did not have a greater peak pullout force than nonaugmented expandable screws. PMMA augmentation provided a greater peak pullout force than calcium phosphate augmentation. Expandable pedicle screws had greater peak pullout forces than standard pedicle screws and had the advantage of augmentation with either PMMA or calcium phosphate cement. Although calcium phosphate cement is biodegradable, osteoconductive, and nonexothermic, PMMA provided a significantly greater peak pullout force. PMMA-augmented expandable 40-mm four-fin pedicle screws had the greatest peak pullout force.

  13. Development of import subtituting technologies for increasing productivity of sintering machines and strength of agglomerates

    Directory of Open Access Journals (Sweden)

    В. Л. Трушко

    2016-11-01

    Full Text Available A problem of industrial fluxed agglomerates self-destruction in the process of cooling after sintering has been examined. It has been revealed that the main reason of strength degradation is polymorphism of dicalcium silicate Ca2SiO4 (or short designation С2S: β-Ca2SiO4 ® γ-Ca2SiO4. Ways for increasing the  agglomerate  strength by physical and crystal-chemical stabilization of the high temperature modification of C2S have been proposed and tested. Physical stabilization of C2S agglomerate is increased with its structure reinforcement due to thickening of walls between large pores that is achieved by increasing height of the sintered layer through improvement of its gas permeability. The task is addressed by substituting the previously used import sintering ore with the  polydisperse ore from the Yakovlevo field, which improves the charge  pelletizing by 3-4 times and helps to bring the  height of the sintered layer and the strength of the domestic agglomerate up to the international best practice standards, while eliminating a need to purchase import high-vacuum   exhausters. In practice crystal-chemical stabilization of C2S within iron-ore  agglomerate is ensured by adding an  opti- mal multicomponent additive in the form of the    waste product  generated in production  of alumina  from bauxites, i.e. the red mud, to the initial sinter charge. Thus mechanical strength of agglomerates and pellets is increased by 5-10 % and their hot strength improves by 20-40 %. The productivity of sintering machines and blast furnaces improves by 5-10 %. Specific coke consumption reduces by 2-2.5 %. In production of iron-ore pellets red mud is substituting the import  bentonite.

  14. Increased residual force enhancement in older adults is associated with a maintenance of eccentric strength.

    Directory of Open Access Journals (Sweden)

    Geoffrey A Power

    Full Text Available Despite an age-related loss of voluntary isometric and concentric strength, muscle strength is well maintained during lengthening muscle actions (i.e., eccentric strength in old age. Additionally, in younger adults during lengthening of an activated skeletal muscle, the force level observed following the stretch is greater than the isometric force at the same muscle length. This feature is termed residual force enhancement (RFE and is believed to be a combination of active and passive components of the contractile apparatus. The purpose of this study was to provide an initial assessment of RFE in older adults and utilize aging as a muscle model to explore RFE in a system in which isometric force production is compromised, but structural mechanisms of eccentric strength are well-maintained. Therefore, we hypothesised that older adults will experience greater RFE compared with young adults. Following a reference maximal voluntary isometric contraction (MVC of the dorsiflexors in 10 young (26.1 ± 2.7 y and 10 old (76.0 ± 6.5 y men, an active stretch was performed at 15°/s over a 30° ankle joint excursion ending at the same muscle length as the reference MVCs (40° of plantar flexion. Any additional torque compared with the reference MVC therefore represented RFE. In older men RFE was ~2.5 times greater compared to young. The passive component of force enhancement contributed ~37% and ~20% to total force enhancement, in old and young respectively. The positive association (R(2 = 0.57 between maintained eccentric strength in old age and RFE indicates age-related mechanisms responsible for the maintenance of eccentric strength likely contributed to the observed elevated RFE. Additionally, as indicated by the greater passive force enhancement, these mechanisms may be related to increased muscle series elastic stiffness in old age.

  15. Increased sclerostin associated with stress fracture of the third metacarpal bone in the Thoroughbred racehorse

    Science.gov (United States)

    Singer, E.; Henson, F.

    2018-01-01

    Objectives The exact aetiology and pathogenesis of microdamage-induced long bone fractures remain unknown. These fractures are likely to be the result of inadequate bone remodelling in response to damage. This study aims to identify an association of osteocyte apoptosis, the presence of osteocytic osteolysis, and any alterations in sclerostin expression with a fracture of the third metacarpal (Mc-III) bone of Thoroughbred racehorses. Methods A total of 30 Mc-III bones were obtained; ten bones were fractured during racing, ten were from the contralateral limb, and ten were from control horses. Each Mc-III bone was divided into a fracture site, condyle, condylar groove, and sagittal ridge. Microcracks and diffuse microdamage were quantified. Apoptotic osteocytes were measured using TUNEL staining. Cathepsin K, matrix metalloproteinase-13 (MMP-13), HtrA1, and sclerostin expression were analyzed. Results In the fracture group, microdamage was elevated 38.9% (sd 2.6) compared with controls. There was no difference in the osteocyte number and the percentage of apoptotic cells between contralateral limb and unraced control; however, there were significantly fewer apoptotic cells in fractured samples (p fractured samples, sclerostin expression was significantly higher (p fractured during racing. In this study, this is not associated with osteocyte apoptosis or osteocytic osteolysis. The finding of increased sclerostin in the region of the fracture suggests that this protein may be playing a key role in the regulation of bone microdamage during stress adaptation. Cite this article: N. Hopper, E. Singer, F. Henson. Increased sclerostin associated with stress fracture of the third metacarpal bone in the Thoroughbred racehorse. Bone Joint Res 2018;7:94–102. DOI: 10.1302/2046-3758.71.BJR-2016-0202.R4. PMID:29363519

  16. Anorexia Nervosa and Bone

    Science.gov (United States)

    Misra, Madhusmita; Klibanski, Anne

    2014-01-01

    Anorexia nervosa (AN) is a condition of severe low weight that is associated with low bone mass, impaired bone structure and reduced bone strength, all of which contribute to increased fracture risk., Adolescents with AN have decreased rates of bone accrual compared with normal-weight controls, raising addition concerns of suboptimal peak bone mass and future bone health in this age group. Changes in lean mass and compartmental fat depots, hormonal alterations secondary to nutritional factors contribute to impaired bone metabolism in AN. The best strategy to improve bone density is to regain weight and menstrual function. Oral estrogen-progesterone combinations are not effective in increasing bone density in adults or adolescents with AN, and transdermal testosterone replacement is not effective in increasing bone density in adult women with AN. However, physiologic estrogen replacement as transdermal estradiol with cyclic progesterone does increase bone accrual rates in adolescents with AN to approximate that in normal-weight controls, leading to a maintenance of bone density Z-scores. A recent study has shown that risedronate increases bone density at the spine and hip in adult women with AN. However, bisphosphonates should be used with great caution in women of reproductive age given their long half-life and potential for teratogenicity, and should be considered only in patients with low bone density and clinically significant fractures when non-pharmacological therapies for weight gain are ineffective. Further studies are necessary to determine the best therapeutic strategies for low bone density in AN. PMID:24898127

  17. Increased circulating rather than spinal cytokines accompany chronic pain behaviors in experimental bone cancer and arthritis

    Directory of Open Access Journals (Sweden)

    Line Pourtau

    2014-12-01

    Full Text Available Aim: Peripheral cytokines contribute to arthritis and bone cancer pain through sensory nerve actions. However, increased spinal cytokine and glial filament expression, coined neuroinflammation, has also been proposed to play a part in chronic pain. Therefore, spinal cord, dorsal root ganglia and circulating cytokines were compared in murine arthritis and bone cancer models in relationship to behavioral signs of pain. Methods: Exploratory behaviors were studied after intra-articular complete Freund's adjuvant or bone intramedullary sarcoma cell injection. Nervous tissue and blood cytokine expression were determined by real-time polymerase chain reaction (PCR and multiplex immunoassays, respectively. Results: PCR analysis did not reveal any hallmark of spinal neuroinflammation in spontaneously-behaving mice with cartilage or bone lesions. However, imposed paw stimulation during joint inflammation increased spinal interleukin-1β (IL-1β expression. Spontaneous paw guarding during rearing was displayed by animals with joint inflammation and bone destruction and was accompanied by increased circulating IL-6 and monocyte chemoattractant protein-1, respectively. In addition, dorsal root ganglia were found to constitutively express receptors for this chemotactic cytokine. Conclusion: Our findings indicate that spinal neuroinflammation is not a necessary condition for chronic pain and suggest that circulating cytokine action in dorsal root ganglia may contribute to experimental joint inflammation and bone cancer pain.

  18. Later Age at Onset of Independent Walking Is Associated With Lower Bone Strength at Fracture-Prone Sites in Older Men.

    Science.gov (United States)

    Ireland, Alex; Muthuri, Stella; Rittweger, Joern; Adams, Judith E; Ward, Kate A; Kuh, Diana; Cooper, Rachel

    2017-06-01

    Later age at onset of independent walking is associated with lower leg bone strength in childhood and adolescence. However, it is unknown whether these associations persist into older age or whether they are evident at axial (central) or upper limb sites. Therefore, we examined walking age obtained at age 2 years and bone outcomes obtained by dual-energy X-ray absorptiometry (DXA) and peripheral quantitative computed tomography (pQCT) scans at ages 60 to 64 years in a nationally representative cohort study of British people, the MRC National Survey of Health and Development. It was hypothesized that later walking age would be associated with lower bone strength at all sites. Later independent walking age was associated with lower height-adjusted hip (standardized regression coefficients with 95% confidence interval [CI] -0.179 [-0.251 to -0.107]), spine (-0.157 [-0.232 to -0.082]), and distal radius (-0.159 [-0.245 to -0.073]) bone mineral content (BMC, indicating bone compressive strength) in men (all p lower lean mass and adolescent sporting ability in later walkers. These associations were also evident for a number of hip geometric parameters (including cross-sectional moment of inertia [CSMI], indicating bone bending/torsional strength) assessed by hip structural analysis (HSA) from DXA scans. Similar height-adjusted associations were also observed in women for several hip, spine, and upper limb outcomes, although adjustment for fat or lean mass led to complete attenuation for most outcomes, with the exception of femoral shaft CSMI and spine bone area (BA). In conclusion, later independent walking age appears to have a lifelong association with bone strength across multiple skeletal sites in men. These effects may result from direct effects of early life loading on bone growth and mediation by adult body composition. Results suggest that late walking age may represent a novel risk factor for subsequent low bone strength. Existing interventions effective in

  19. A combination of resistance and endurance training increases leg muscle strength in COPD

    DEFF Research Database (Denmark)

    Iepsen, Ulrik Winning; Jørgensen, Karsten Juhl; Ringbæk, Thomas

    2015-01-01

    Resistance training (RT) is thought to be effective in preventing muscle depletion, whereas endurance training (ET) is known to improve exercise capacity and health-related quality of life (HRQoL) in chronic obstructive pulmonary disease (COPD). Our objectives were to assess the efficiency...... improvements in HRQoL, walking distance and exercise capacity. However, we found moderate quality evidence of a significant increase in leg muscle strength favouring a combination of RT and ET (standardized mean difference of 0.69 (95% confidence interval: 0.39-0.98). In conclusion, we found significantly...... increased leg muscle strength favouring a combination of RT with ET compared with ET alone. Therefore, we recommend that RT should be incorporated in rehabilitation of COPD together with ET....

  20. Increased Dickkopf-1 expression accelerates bone cell apoptosis in femoral head osteonecrosis.

    Science.gov (United States)

    Ko, Jih-Yang; Wang, Feng-Sheng; Wang, Ching-Jen; Wong, To; Chou, Wen-Yi; Tseng, Shin-Ling

    2010-03-01

    Intensive bone cell apoptosis contributes to osteonecrosis of femoral head (ONFH). Dickkopf-1 (DKK1) reportedly mediates various types of skeletal disorders. This study investigated whether DKK1 was linked to the occurrence of ONFH. Thirty-nine patients with various stages of ONFH were recruited. Bone specimens were harvested from 34 ONFH patients underwent hip arthroplasty, and from 10 femoral neck fracture patients. Bad, Bcl2 TNFalpha, DKK1, Wnt3a, LRP5, and Axin1 expressions were analyzed by quantitative RT-PCR and ELISA. Apoptotic cells were assayed using terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end-labelling (TUNEL). Primary bone-marrow mesenchymal cells were treated with DKK1 RNA interference and recombinant DKK1 protein. ONFH patients with the histories of being administrated corticosteroids and excessive alcohol consumption had significantly higher Bad and DKK1 mRNA expressions in bone tissue and DKK1 abundances in serum than femoral neck fracture patients. Bone cells adjacent to osteonecrotic bone displayed strong DKK1 immunoreactivity and TUNEL staining. Increased DKK1 expression in bone tissue and serum correlated with Bad expression and TUNEL staining. Serum DKK1 abundance correlated with the severity of ONFH. The DKK1 RNA interference and recombinant DKK1 protein regulated Bad expression and apoptosis of primary bone-marrow mesenchymal cells. Knock down of DKK1 reduced dexamethasone-induced apoptosis of mesenchymal cells. Taken together, promoted DKK1 expression was associated with bone cell apoptosis in the occurrence of ONFH patients with the histories of corticosteroid and alcohol intake and progression of ONFH. DKK1 expression in injured tissue provides new insight into ONFH pathogenesis.

  1. Increased sclerostin associated with stress fracture of the third metacarpal bone in the Thoroughbred racehorse.

    Science.gov (United States)

    Hopper, N; Singer, E; Henson, F

    2018-01-01

    The exact aetiology and pathogenesis of microdamage-induced long bone fractures remain unknown. These fractures are likely to be the result of inadequate bone remodelling in response to damage. This study aims to identify an association of osteocyte apoptosis, the presence of osteocytic osteolysis, and any alterations in sclerostin expression with a fracture of the third metacarpal (Mc-III) bone of Thoroughbred racehorses. A total of 30 Mc-III bones were obtained; ten bones were fractured during racing, ten were from the contralateral limb, and ten were from control horses. Each Mc-III bone was divided into a fracture site, condyle, condylar groove, and sagittal ridge. Microcracks and diffuse microdamage were quantified. Apoptotic osteocytes were measured using TUNEL staining. Cathepsin K, matrix metalloproteinase-13 (MMP-13), HtrA1, and sclerostin expression were analyzed. In the fracture group, microdamage was elevated 38.9% (sd 2.6) compared with controls. There was no difference in the osteocyte number and the percentage of apoptotic cells between contralateral limb and unraced control; however, there were significantly fewer apoptotic cells in fractured samples (p fractured samples, sclerostin expression was significantly higher (p bones that have fractured during racing. In this study, this is not associated with osteocyte apoptosis or osteocytic osteolysis. The finding of increased sclerostin in the region of the fracture suggests that this protein may be playing a key role in the regulation of bone microdamage during stress adaptation. Cite this article: Bone Joint Res 2018;7:94-102. © 2018 Hopper et al.

  2. Contributions of Severe Burn and Disuse to Bone Structure and Strength in Rats

    Science.gov (United States)

    2013-01-01

    hydroxyapatite phantom to ensure CT value Hounsfeld Units consistency. Each bone was imaged at 80 kVp, 80 μA, and at a resolution level producing isotropic 25 μm...Surg Res 2003;114:172-8. [16] Klein GL, Herndon DN, Goodman WG, Langman CB, Phillips WA, Dickson IR , et al. Histomorphometric and biochemical

  3. Fixation strength analysis of cup to bone material using finite element simulation

    NARCIS (Netherlands)

    Anwar, Iwan Budiwan; Saputra, Eko; Ismail, Rifky; Jamari, J.; Van Der Heide, Emile

    2016-01-01

    Fixation of acetabular cup to bone material is an important initial stability for artificial hip joint. In general, the fixation in cement less-type acetabular cup uses press-fit and screw methods. These methods can be applied alone or together. Based on literature survey, the additional screw

  4. Resolution Improvements in in Vivo1H NMR Spectra with Increased Magnetic Field Strength

    Science.gov (United States)

    Gruetter, Rolf; Weisdorf, Sally A.; Rajanayagan, Vasantham; Terpstra, Melissa; Merkle, Hellmut; Truwit, Charles L.; Garwood, Michael; Nyberg, Scott L.; Ugurbil, Kâmil

    1998-11-01

    The measurement of cerebral metabolites using highly homologous localization techniques and similar shimming methods was performed in the human brain at 1.5 and 4 T as well as in the dog and rat brain at 9.4 T. In rat brain, improved resolution was achieved by shimming all first- and second-order shim coils using a fully adiabatic FASTMAP sequence. The spectra showed a clear improvement in spectral resolution for all metabolite resonances with increased field strength. Changes in cerebral glutamine content were clearly observed at 4 T compared to 1.5 T in patients with hepatic encephalopathy. At 9.4 T, glutamine H4 at 2.46 ppm was fully resolved from glutamate H4 at 2.37 ppm, as was the potential resonance from γ-amino-butyric acid at 2.30 ppm and N-acetyl-aspartyl-glutamate at 2.05 ppm. Singlet linewidths were found to be as low as 6 Hz (0.015 ppm) at 9.4 T, indicating a substantial decrease in ppm linewidth with field strength. Furthermore, the methylene peak of creatine was partially resolved from phosphocreatine, indicating a close to 1:1 relationship in gray matter. We conclude that increasing the magnetic field strength increases spectral resolution also for1H NMR, which can lead to more than linear sensitivity gains.

  5. Two developmentally temporal quantitative trait loci underlie convergent evolution of increased branchial bone length in sticklebacks

    Science.gov (United States)

    Erickson, Priscilla A.; Glazer, Andrew M.; Cleves, Phillip A.; Smith, Alyson S.; Miller, Craig T.

    2014-01-01

    In convergent evolution, similar phenotypes evolve repeatedly in independent populations, often reflecting adaptation to similar environments. Understanding whether convergent evolution proceeds via similar or different genetic and developmental mechanisms offers insight towards the repeatability and predictability of evolution. Oceanic populations of threespine stickleback fish, Gasterosteus aculeatus, have repeatedly colonized countless freshwater lakes and streams, where new diets lead to morphological adaptations related to feeding. Here, we show that heritable increases in branchial bone length have convergently evolved in two independently derived freshwater stickleback populations. In both populations, an increased bone growth rate in juveniles underlies the convergent adult phenotype, and one population also has a longer cartilage template. Using F2 crosses from these two freshwater populations, we show that two quantitative trait loci (QTL) control branchial bone length at distinct points in development. In both populations, a QTL on chromosome 21 controls bone length throughout juvenile development, and a QTL on chromosome 4 controls bone length only in adults. In addition to these similar developmental profiles, these QTL show similar chromosomal locations in both populations. Our results suggest that sticklebacks have convergently evolved longer branchial bones using similar genetic and developmental programmes in two independently derived populations. PMID:24966315

  6. Evaluation of Significance of Diffusely Increased Bilateral Renal Uptake on Bone Scan

    Energy Technology Data Exchange (ETDEWEB)

    Sung, Mi Sook; Yang, Woo Jin; Byun, Jae Young; Park, Jung Mi; Shinn, Kyung Sub; Bahk, Yong Whee [Catholic University College of Medicine, Seoul (Korea, Republic of)

    1990-03-15

    Unexpected renal abnormality can be detected on bone scan using {sup 99m}Tc-MDP. The purpose of the study is to evaluate the diagnostic significance of diffusely increased bilateral renal uptake on bone scan. 1,500 bone scan were reviewed and 43 scans which showed diffusely increased bilateral renal uptake were selected for analysis. Laboratory findings for renal and liver function tests including routine urinalysis were reviewed in 43 patients. 26 of 43 case showed abnormality in urinalysis and renal function study. 20 of 43 cases showed abnormal liver function study and 3 of these cases were diagnosed as hepatorenal syndrome later. 13 of those 20 cases had liver cirrhosis with or without hepatoma. 12 of 43 cases showed abnormality both in renal and liver function studies. 2 of 43 cases showed diffusely increased bilateral renal uptake after chemotherapy for cancer but not on previous scans before chemotherapy. 2 of 43 cases showed hypercalcaemia and 8 of 43 cases had multifocal bone uptake due to metastasis or benign bone lesion. But the latter showed no hypercalcaemia at all. There was no significant correlation between increased renal uptake and MDP uptake in soft tissue other than kidneys. This study raised the possibility that the impaired liver and/or renal function may result in diffuse increase of bilateral renal uptake of MDP of unknown mechanism. It seems to need further study on this correlation.

  7. Evaluation of Significance of Diffusely Increased Bilateral Renal Uptake on Bone Scan

    International Nuclear Information System (INIS)

    Sung, Mi Sook; Yang, Woo Jin; Byun, Jae Young; Park, Jung Mi; Shinn, Kyung Sub; Bahk, Yong Whee

    1990-01-01

    Unexpected renal abnormality can be detected on bone scan using 99m Tc-MDP. The purpose of the study is to evaluate the diagnostic significance of diffusely increased bilateral renal uptake on bone scan. 1,500 bone scan were reviewed and 43 scans which showed diffusely increased bilateral renal uptake were selected for analysis. Laboratory findings for renal and liver function tests including routine urinalysis were reviewed in 43 patients. 26 of 43 case showed abnormality in urinalysis and renal function study. 20 of 43 cases showed abnormal liver function study and 3 of these cases were diagnosed as hepatorenal syndrome later. 13 of those 20 cases had liver cirrhosis with or without hepatoma. 12 of 43 cases showed abnormality both in renal and liver function studies. 2 of 43 cases showed diffusely increased bilateral renal uptake after chemotherapy for cancer but not on previous scans before chemotherapy. 2 of 43 cases showed hypercalcaemia and 8 of 43 cases had multifocal bone uptake due to metastasis or benign bone lesion. But the latter showed no hypercalcaemia at all. There was no significant correlation between increased renal uptake and MDP uptake in soft tissue other than kidneys. This study raised the possibility that the impaired liver and/or renal function may result in diffuse increase of bilateral renal uptake of MDP of unknown mechanism. It seems to need further study on this correlation.

  8. Deficiency of retinaldehyde dehydrogenase 1 induces BMP2 and increases bone mass in vivo.

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    Shriram Nallamshetty

    Full Text Available The effects of retinoids, the structural derivatives of vitamin A (retinol, on post-natal peak bone density acquisition and skeletal remodeling are complex and compartment specific. Emerging data indicates that retinoids, such as all trans retinoic acid (ATRA and its precursor all trans retinaldehyde (Rald, exhibit distinct and divergent transcriptional effects in metabolism. Despite these observations, the role of enzymes that control retinoid metabolism in bone remains undefined. In this study, we examined the skeletal phenotype of mice deficient in retinaldehyde dehydrogenase 1 (Aldh1a1, the enzyme responsible for converting Rald to ATRA in adult animals. Bone densitometry and micro-computed tomography (µCT demonstrated that Aldh1a1-deficient (Aldh1a1(-/- female mice had higher trabecular and cortical bone mass compared to age and sex-matched control C57Bl/6 wild type (WT mice at multiple time points. Histomorphometry confirmed increased cortical bone thickness and demonstrated significantly higher bone marrow adiposity in Aldh1a1(-/- mice. In serum assays, Aldh1a1(-/- mice also had higher serum IGF-1 levels. In vitro, primary Aldh1a1(-/- mesenchymal stem cells (MSCs expressed significantly higher levels of bone morphogenetic protein 2 (BMP2 and demonstrated enhanced osteoblastogenesis and adipogenesis versus WT MSCs. BMP2 was also expressed at higher levels in the femurs and tibias of Aldh1a1(-/- mice with accompanying induction of BMP2-regulated responses, including expression of Runx2 and alkaline phosphatase, and Smad phosphorylation. In vitro, Rald, which accumulates in Aldh1a1(-/- mice, potently induced BMP2 in WT MSCs in a retinoic acid receptor (RAR-dependent manner, suggesting that Rald is involved in the BMP2 increases seen in Aldh1a1 deficiency in vivo. Collectively, these data implicate Aldh1a1 as a novel determinant of cortical bone density and marrow adiposity in the skeleton in vivo through modulation of BMP signaling.

  9. Deficiency of retinaldehyde dehydrogenase 1 induces BMP2 and increases bone mass in vivo.

    Science.gov (United States)

    Nallamshetty, Shriram; Wang, Hong; Rhee, Eun-Jung; Kiefer, Florian W; Brown, Jonathan D; Lotinun, Sutada; Le, Phuong; Baron, Roland; Rosen, Clifford J; Plutzky, Jorge

    2013-01-01

    The effects of retinoids, the structural derivatives of vitamin A (retinol), on post-natal peak bone density acquisition and skeletal remodeling are complex and compartment specific. Emerging data indicates that retinoids, such as all trans retinoic acid (ATRA) and its precursor all trans retinaldehyde (Rald), exhibit distinct and divergent transcriptional effects in metabolism. Despite these observations, the role of enzymes that control retinoid metabolism in bone remains undefined. In this study, we examined the skeletal phenotype of mice deficient in retinaldehyde dehydrogenase 1 (Aldh1a1), the enzyme responsible for converting Rald to ATRA in adult animals. Bone densitometry and micro-computed tomography (µCT) demonstrated that Aldh1a1-deficient (Aldh1a1(-/-) ) female mice had higher trabecular and cortical bone mass compared to age and sex-matched control C57Bl/6 wild type (WT) mice at multiple time points. Histomorphometry confirmed increased cortical bone thickness and demonstrated significantly higher bone marrow adiposity in Aldh1a1(-/-) mice. In serum assays, Aldh1a1(-/-) mice also had higher serum IGF-1 levels. In vitro, primary Aldh1a1(-/-) mesenchymal stem cells (MSCs) expressed significantly higher levels of bone morphogenetic protein 2 (BMP2) and demonstrated enhanced osteoblastogenesis and adipogenesis versus WT MSCs. BMP2 was also expressed at higher levels in the femurs and tibias of Aldh1a1(-/-) mice with accompanying induction of BMP2-regulated responses, including expression of Runx2 and alkaline phosphatase, and Smad phosphorylation. In vitro, Rald, which accumulates in Aldh1a1(-/-) mice, potently induced BMP2 in WT MSCs in a retinoic acid receptor (RAR)-dependent manner, suggesting that Rald is involved in the BMP2 increases seen in Aldh1a1 deficiency in vivo. Collectively, these data implicate Aldh1a1 as a novel determinant of cortical bone density and marrow adiposity in the skeleton in vivo through modulation of BMP signaling.

  10. Strength of bone tunnel versus suture anchor and push-lock construct in Broström repair.

    Science.gov (United States)

    Giza, Eric; Nathe, Ryan; Nathe, Tyler; Anderson, Matthew; Campanelli, Valentina

    2012-06-01

    Operative treatment of mechanical ankle instability is indicated for patients who have had multiple sprains and have continued episodes of instability despite bracing and rehabilitation. Anatomic reconstruction has been shown to have improved outcomes and return to sport as compared with nonanatomic reconstruction. The use of 2 suture anchors and a push-lock anchor is equal to 2 bone tunnels in strength to failure for anatomic Broström repair. Controlled laboratory study. In 7 matched pairs of human cadaver ankles, the calcaneofibular ligament (CFL) and anterior talofibular ligament (ATFL) were incised from their origin on the fibula. A No. 2 Fiberwire suture was placed into the CFL and a separate suture into the ATFL in a running Krackow fashion with a total of 4 locking loops. In 1 ankle of the matched pair, the ligaments were repaired to their anatomic insertion with bone tunnels. In the other, 2 suture anchors were used to reattach the ligaments to their anatomic origins, and a push-lock was used proximally to reinforce these suture anchors. The ligaments were cyclically loaded 20 times and then tested to failure. Torque to failure, degrees to failure, and stiffness were measured. The authors performed a matched pair analysis. An a priori power analysis of 0.8 demonstrated 6 pairs were needed to show a difference of 30% with a 15% standard error at a significance level of .05. There was no difference in the degrees to failure, torque to failure, and stiffness. A post hoc power analysis of torque to failure showed a power of .89 with 7 samples. Power for initial stiffness was .97 with 7 samples. Eleven of 14 specimens failed at either the suture anchor or the bone tunnel. There is no statistical difference in strength or stiffness for a suture anchor and push-lock construct as compared with a bone tunnel construct for an anatomic repair of the lateral ligaments of the ankle. The use of suture anchors in lateral ligament stabilization allows for a smaller

  11. Increased Vertebral Bone Mineral in Response to Reduced Exercise in Amenorrheic Runners

    OpenAIRE

    Lindberg, Jill S.; Hunt, Marjorie M.; Wade, Charles E.; Powell, Malcolm R.; Ducey, Diane E.

    1987-01-01

    Seven female runners found to have exercise-induced amenorrhea and decreased bone mineral were reevaluated after 15 months. During the 15-month period, four runners took supplemental calcium and reduced their weekly running distance by 43%, resulting in an average 5% increase in body weight, increased estradiol levels and eumenorrhea. Bone mineral content increased from 1.003±0.097 to 1.070±0.089 grams per cm.2 Three runners continued to have amenorrhea, with no change in running distance or ...

  12. Peak lean tissue mass accrual precedes changes in bone strength indices at the proximal femur during the pubertal growth spurt.

    Science.gov (United States)

    Jackowski, Stefan A; Faulkner, Robert A; Farthing, Jonathan P; Kontulainen, Saija A; Beck, Thomas J; Baxter-Jones, Adam D G

    2009-06-01

    We examined the timing of the age and the magnitude of peak lean tissue mass accrual (PLTV) relative to the age and magnitude of two variables of bone strength [peak cross sectional area velocity (PCSAV), and peak section modulus velocity, (PZV)] at the proximal femur in males and females during the adolescent growth spurt. We hypothesized that the age of PLTV would precede the ages of PCSAV and PZV and that there is a positive relationship between the magnitude of PLTV and both PCSAV and PZV in both genders. 41 males and 42 females aged 8-18 years were selected from the Saskatchewan Pediatric Bone Mineral Accrual Study (1991-2005). Participants' total body lean tissue mass was assessed annually for 6 consecutive years using DXA. Narrow neck and femoral shaft cross sectional areas (CSA) and section modulus (Z) were determined using the hip structural analysis (HSA) program. Participants were aligned by maturational age (years from peak height velocity). Lean tissue mass, CSA, and Z were converted into whole year velocities and the maturational age of peak tissue velocities was determined using a cubic spline curve fitting procedure. A 2 x 3 (gender x tissue) factorial MANOVA with repeated measures was used to test for differences between age of PLTV and the ages of PCSAV and PZV between genders. Multiple regression analyses were used to examine the relationship between PLTV and both PCSAV and PZV. There were no sex differences in the ages at which tissue peaks occurred when aligned by maturational age. There were significant differences between the age of PLTV and both PCSAV and PZV at the narrow neck (p=0.001) and femoral shaft (p=0.03), where the age of PLTV preceded both PCSAV and PZV when pooled by gender. PLTV was a significant predictor of the magnitude of both PCSAV and PZV at all sites (ptheory that muscle development is an important factor in affecting bone strength.

  13. Associations of dietary patterns with bone mass, muscle strength and balance in a cohort of Australian middle-aged women.

    Science.gov (United States)

    Wu, Feitong; Wills, Karen; Laslett, Laura L; Oldenburg, Brian; Jones, Graeme; Winzenberg, Tania

    2017-10-01

    Influences of dietary patterns on musculoskeletal health are poorly understood in middle-aged women. This cross-sectional analysis from a cohort of 347 women (aged 36-57 years) aimed to examine associations between dietary patterns and musculoskeletal health outcomes in middle-aged women. Diet was measured by the Cancer Council of Victoria FFQ. Total body bone mineral content (TB BMC), femoral neck and lumbar spine bone density (dual-energy X-ray absorptiometry), lower limbs muscle strength (LMS) and balance tests (timed up and go test, step test, functional reach test (FRT) and lateral reach test) were also measured. Exploratory factor analysis was used to identify dietary patterns and scores for each pattern generated using factor loadings with absolute values ≥0·20. Associations between food pattern scores and musculoskeletal outcomes were assessed using multivariable linear regression. Three dietary patterns were identified: 'Healthy' (high consumption of a plant-based diet - vegetables, legumes, fruit, tomatoes, nuts, snacks, garlic, whole grains and low intake of high-fat dairy products), 'high protein, high fat' (red meats, poultry, processed meats, potatoes, cruciferous and dark-yellow vegetables, fish, chips, spirits and high-fat dairy products) and 'Processed foods' (high intakes of meat pies, hamburgers, beer, sweets, fruit juice, processed meats, snacks, spirits, pizza and low intake of cruciferous vegetables). After adjustment for confounders, Healthy pattern was positively associated with LMS, whereas Processed foods pattern was inversely associated with TB BMC and FRT. The associations were not significant after accounting for multiple comparisons. There were no associations with any other outcomes. These results suggest that maintaining a healthy diet could contribute to bone acquisition, muscle strength and balance in adult life. However, while they provide some support for further investigating dietary strategies for prevention of age

  14. Direct lentiviral-cyclooxygenase 2 application to the tendon-bone interface promotes osteointegration and enhances return of the pull-out tensile strength of the tendon graft in a rat model of biceps tenodesis.

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    Charles H Rundle

    Full Text Available This study sought to determine if direct application of the lentiviral (LV-cyclooxygenase 2 (COX2 vector to the tendon-bone interface would promote osteointegration of the tendon graft in a rat model of biceps tenodesis. The LV-COX2 gene transfer strategy was chosen for investigation because a similar COX2 gene transfer strategy promoted bony bridging of the fracture gap during bone repair, which involves similar histologic transitions that occur in osteointegration. Briefly, a 1.14-mm diameter tunnel was drilled in the mid-groove of the humerus of adult Fischer 344 rats. The LV-COX2 or βgal control vector was applied directly into the bone tunnel and onto the end of the tendon graft, which was then pulled into the bone tunnel. A poly-L-lactide pin was press-fitted into the tunnel as interference fixation. Animals were sacrificed at 3, 5, or 8 weeks for histology analysis of osteointegration. The LV-COX2 gene transfer strategy enhanced neo-chondrogenesis at the tendon-bone interface but with only marginal effect on de novo bone formation. The tendon-bone interface of the LV-COX2-treated tenodesis showed the well-defined tendon-to-fibrocartilage-to-bone histologic transitions that are indicative of osteointegration of the tendon graft. The LV-COX2 in vivo gene transfer strategy also significantly enhanced angiogenesis at the tendon-bone interface. To determine if the increased osteointegration was translated into an improved pull-out mechanical strength property, the pull-out tensile strength of the LV-COX2-treated tendon grafts was determined with a pull-out mechanical testing assay. The LV-COX2 strategy yielded a significant improvement in the return of the pull-out strength of the tendon graft after 8 weeks. In conclusion, the COX2-based in vivo gene transfer strategy enhanced angiogenesis, osteointegration and improved return of the pull-out strength of the tendon graft. Thus, this strategy has great potential to be developed into an

  15. IS ENHANCED-ECCENTRIC RESISTANCE TRAINING SUPERIOR TO TRADITIONAL TRAINING FOR INCREASING ELBOW FLEXOR STRENGTH?

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    Thomas W. Kaminski

    2003-06-01

    Full Text Available Protocols for strengthening muscle are important for fitness, rehabilitation, and the prevention of myotendinous injuries. In trained individuals, the optimal method of increasing strength remains unclear. The purpose of this study was to compare the effects of a traditional method of strengthening with a method that allowed for enhanced-eccentric training, on changes in elbow flexor strength in trained subjects. Thirty-nine (8 male, 31 female trained subjects with normal elbow function participated in this study. Subjects were rank-ordered according to isometric force production and randomly assigned to one of three training groups: control (CONT, traditional concentric/eccentric (TRAD, and concentric/enhanced-eccentric (NEG. The training groups completed 24 training sessions. An evaluator blinded to training group performed all testing. Mixed model ANOVA techniques were used to determine if differences existed in concentric one repetition maximum strength, and isometric force production among groups. Changes in peak and average isokinetic force production were also compared. Type 1 error was maintained at 5%. While both groups improved concentric one repetition maximum (NEG = 15.5%, TRAD = 13.8% neither training group statistically differed from changes demonstrated by the CONT group. Nor did either training group show significant improvements in isometric or isokinetic force production over the CONT group. These results do not support the superiority of enhanced-eccentric training for increasing force production in trained subjects.

  16. Impact of Crack on Stability of Slope with Linearly Increasing Undrained Strength

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    Bing Li

    2018-01-01

    Full Text Available This paper presents a procedure for assessment of the impact of tension crack on stability of slope in clays with linearly increasing undrained strength. The procedure is based on the limit equilibrium method with variational extremization. The distribution of the normal stress over slip surface is mathematically obtained for slopes in clays with the linearly increasing undrained strength and then used to determine the tension crack for clays with zero tensile strength. The seismic effect is also included using the pseudostatic approach. Closed-form solutions to the minimum safety factor and the maximum crack depth can be derived and given in the form of chart for convenient use. The results demonstrate a significant effect of the tension crack on the stability of steep slopes, especially for strong seismic conditions. In this situation, neglecting the impact of tension crack in traditional ϕ=0 analyses may overestimate the slope safety. The most adverse location of the tension crack can be also determined and presented in the charts, which may be useful in designing reinforcements and remedial measures for slope stabilization.

  17. Increased vertebral bone mineral in response to reduced exercise in amenorrheic runners.

    Science.gov (United States)

    Lindberg, J S; Powell, M R; Hunt, M M; Ducey, D E; Wade, C E

    1987-01-01

    Seven female runners found to have exercise-induced amenorrhea and decreased bone mineral were reevaluated after 15 months. During the 15-month period, four runners took supplemental calcium and reduced their weekly running distance by 43%, resulting in an average 5% increase in body weight, increased estradiol levels and eumenorrhea. Bone mineral content increased from 1.003+/-0.097 to 1.070+/-0.089 grams per cm.(2) Three runners continued to have amenorrhea, with no change in running distance or body weight. Estradiol levels remained abnormally low and there was no significant change in the bone mineral content, although all three took supplemental calcium. We found that early osteopenia associated with exercise-induced menstrual dysfunction improved when runners reduced their running distance, gained weight and became eumenorrheic.

  18. Irisin levels are lower in young amenorrheic athletes compared with eumenorrheic athletes and non-athletes and are associated with bone density and strength estimates.

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    Vibha Singhal

    Full Text Available Irisin and FGF21 are novel hormones implicated in the "browning" of white fat, thermogenesis, and energy homeostasis. However, there are no data regarding these hormones in amenorrheic athletes (AA (a chronic energy deficit state compared with eumenorrheic athletes (EA and non-athletes. We hypothesized that irisin and FGF21 would be low in AA, an adaptive response to low energy stores. Furthermore, because (i brown fat has positive effects on bone, and (ii irisin and FGF21 may directly impact bone, we hypothesized that bone density, structure and strength would be positively associated with these hormones in athletes and non-athletes. To test our hypotheses, we studied 85 females, 14-21 years [38 AA, 24 EA and 23 non-athletes (NA]. Fasting serum irisin and FGF21 were measured. Body composition and bone density were assessed using dual energy X-ray absorptiometry, bone microarchitecture using high resolution peripheral quantitative CT, strength estimates using finite element analysis, resting energy expenditure (REE using indirect calorimetry and time spent exercising/week by history. Subjects did not differ for pubertal stage. Fat mass was lowest in AA. AA had lower irisin and FGF21 than EA and NA, even after controlling for fat and lean mass. Across subjects, irisin was positively associated with REE and bone density Z-scores, volumetric bone mineral density (total and trabecular, stiffness and failure load. FGF21 was negatively associated with hours/week of exercise and cortical porosity, and positively with fat mass and cortical volumetric bone density. Associations of irisin (but not FGF21 with bone parameters persisted after controlling for potential confounders. In conclusion, irisin and FGF21 are low in AA, and irisin (but not FGF21 is independently associated with bone density and strength in athletes.

  19. Lifelong physical activity in maintaining bone strength in older men and women of the Age, Gene/Environment Susceptibility-Reykjavik Study.

    Science.gov (United States)

    Rianon, N J; Lang, T F; Sigurdsson, G; Eiriksdottir, G; Sigurdsson, S; Garcia, M; Pajala, S; Koster, A; Yu, B; Selwyn, B J; Taylor, W C; Kapadia, A S; Gudnason, V; Launer, L J; Harris, T B

    2012-09-01

    We examined if lifelong physical activity is important for maintaining bone strength in the elderly. Associations of quantitative computerized tomography-acquired bone measures (vertebral and femoral) and self-reported physical activity in mid-life (mean age, 50 years), in old age (≥65 years), and throughout life (recalled during old age) were investigated in 2,110 men and 2,682 women in the AGES-Reykjavik Study. Results conclude lifelong physical activity with continuation into old age (≥65 years) best maintains better bone health later in life. Skeletal loading is thought to modulate the loss of bone in later life, and physical activity is a chief means of affecting bone strength by skeletal loading. Despite much discussion regarding lifelong versus early adulthood physical activity for preventing bone loss later in life, inconsistency still exists regarding how to maintain bone mass later in life (≥65 years). We examined if lifelong physical activity is important for maintaining bone strength in the elderly. The associations of quantitative computerized tomography-acquired vertebral and femoral bone measures and self-reported physical activity in mid-life (mean age, 50 years), in old age (≥65 years), and throughout life (recalled during old age) were investigated in 2,110 men and 2,682 women in the AGES-Reykjavik Study. Our findings conclude that lifelong physical activity with continuation into old age (≥65 years) best maintains better bone health in the elderly.

  20. Bone Resorption Increases as Early as the Second Day in Head- Down Bed Rest

    Science.gov (United States)

    Heer, M.; Kamps, N.; Mika, C.; Boese, A.; Gerzer, R.

    Long-term bed rest and space mission studies have shown that immobilization as well as microgravity induce increased bone resorption while bone formation tends to decrease. In order to analyze the kinetics of short-term changes in bone turnover we studied in a randomized, strictly controlled crossover design the effects of 6 days 6° head-down tilt bed rest (HDT) in 8 male healthy subjects (mean body weight (BW): 70.1 +/- 1.88 kg; mean age: 25.5 +/- 1.04 years) in our metabolic ward. Two days before arriving in the metabolic ward the subjects started with a diet consisting of an energy content of 10 MJ/d, 2000 mg Calcium/d, 400 i.U. Vitamin D, 200 mEq Na+ and 50 ml water/kg BW/d. The diet was continued in the metabolic ward. The metabolic ward period (11days) was divided into 3 parts: 4 ambulatory days, 6 days either HDT or control and 1 recovery day. Continuous urine collection started on the first day in the metabolic ward to analyze calcium excretion and bone resorption markers, namely C-telopeptide (CTX) and N-telopeptide (NTX). On the 2nd ambulatory day in the metabolic ward and on the 5th day in HDT or control blood was drawn to analyze serum calcium, parathyroid hormone, and bone formation markers (bone Alkaline Phosphatase (bAP), Procollagen-I-Propeptide (P-I-CP). Both study phases were identical with respect to environmental conditions, study protocol and diet. Urinary calcium excretion was as early as the first day in immobilization increased (pcontrol. But, already on the 2nd day of immobilization both bone resorption markers significantly increased. NTX-excretion was increased by 28.7 +/- 14.0% (pcontrol. In contrast to the bone resorption markers, the formation marker P-I-CP tended to decrease as early as the fifth day of immobilization (phormone-, as well as bAP concentrations were unchanged. We conclude from these results of a pronounced rise of bone resorption markers that already 24 hours of immobilization induce a significant rise in osteoclast

  1. Dietary boron does not affect tooth strength, micro-hardness, and density, but affects tooth mineral composition and alveolar bone mineral density in rabbits fed a high-energy diet.

    Science.gov (United States)

    Hakki, Sema S; SiddikMalkoc; Dundar, Niyazi; Kayis, Seyit Ali; Hakki, Erdogan E; Hamurcu, Mehmet; Baspinar, Nuri; Basoglu, Abdullah; Nielsen, Forrest H; Götz, Werner

    2015-01-01

    The objective of this study was to determine whether dietary boron (B) affects the strength, density and mineral composition of teeth and mineral density of alveolar bone in rabbits with apparent obesity induced by a high-energy diet. Sixty female, 8-month-old, New Zealand rabbits were randomly assigned for 7 months into five groups as follows: (1) control 1, fed alfalfa hay only (5.91 MJ/kg and 57.5 mg B/kg); (2) control 2, high energy diet (11.76 MJ and 3.88 mg B/kg); (3) B10, high energy diet + 10 mg B gavage/kg body weight/96 h; (4) B30, high energy diet + 30 mg B gavage/kg body weight/96 h; (5) B50, high energy diet + 50 mg B gavage/kg body weight/96 h. Maxillary incisor teeth of the rabbits were evaluated for compression strength, mineral composition, and micro-hardness. Enamel, dentin, cementum and pulp tissue were examined histologically. Mineral densities of the incisor teeth and surrounding alveolar bone were determined by using micro-CT. When compared to controls, the different boron treatments did not significantly affect compression strength, and micro-hardness of the teeth, although the B content of teeth increased in a dose-dependent manner. Compared to control 1, B50 teeth had decreased phosphorus (P) concentrations. Histological examination revealed that teeth structure (shape and thickness of the enamel, dentin, cementum and pulp) was similar in the B-treated and control rabbits. Micro CT evaluation revealed greater alveolar bone mineral density in B10 and B30 groups than in controls. Alveolar bone density of the B50 group was not different than the controls. Although the B treatments did not affect teeth structure, strength, mineral density and micro-hardness, increasing B intake altered the mineral composition of teeth, and, in moderate amounts, had beneficial effects on surrounding alveolar bone.

  2. Resin cements formulated with thio-urethanes can strengthen porcelain and increase bond strength to ceramics.

    Science.gov (United States)

    Bacchi, Atais; Spazzin, Aloisio Oro; de Oliveira, Gabriel Rodrigues; Pfeifer, Carmem; Cesar, Paulo Francisco

    2018-06-01

    The use of thio-urethane oligomers has been shown to significantly improve the mechanical properties of resin cements (RCs). The aim of this study was to use thio-urethane-modified RC to potentially reinforce the porcelain-RC structure and to improve the bond strength to zirconia and lithium disilicate. Six oligomers were synthesized by combining thiols - pentaerythritol tetra-3-mercaptopropionate (PETMP, P) or trimethylol-tris-3-mercaptopropionate (TMP, T) - with di-functional isocyanates - 1,6-Hexanediol-diissocyante (HDDI) (aliphatic, AL) or 1,3-bis(1-isocyanato-1-methylethyl)benzene (BDI) (aromatic, AR) or Dicyclohexylmethane 4,4'-Diisocyanate (HMDI) (cyclic, CC). Thio-urethanes (20 wt%) were added to a BisGMA/UDMA/TEGDMA organic matrix. Filler was introduced at 60 wt%. The microshear bond strength (μSBS), Weibull modulus (m), and failure pattern of RCs bonded to zirconia (ZR) and lithium disilicate (LD) ceramics was evaluated. Biaxial flexural test and fractographic analysis of porcelain discs bonded to RCs were also performed. The biaxial flexural strength (σ bf ) and m were calculated in the tensile surfaces of porcelain and RC structures (Z = 0 and Z = -t 2 , respectively). The μSBS was improved with RCs formulated with oligomers P_AL or T_AL bonded to LD and P_AL, P_AR or T_CC bonded to zirconia in comparison to controls. Mixed failures predominated in all groups. σ bf had superior values at Z = 0 with RCs formulated with oligomers P_AL, P_AR, T_AL, or T_CC in comparison to control; σ bf increased with all RCs composed by thio-urethanes at Z = -t 2 . Fractographic analysis revealed all fracture origins at Z = 0. The use of specific thio-urethane oligomers as components of RCs increased both the biaxial flexural strength of the porcelain-RC structure and the μSBS to LD and ZR. The current investigation suggests that it is possible to reinforce the porcelain-RC pair and obtain higher bond strength to LD and ZR with RCs

  3. High Birth Weight Increases the Risk for Bone Tumor: A Systematic Review and Meta-Analysis

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    Songfeng Chen

    2015-09-01

    Full Text Available There have been several epidemiologic studies on the relationship between high birth weight and the risk for bone tumor in the past decades. However, due to the rarity of bone tumors, the sample size of individual studies was generally too small for reliable conclusions. Therefore, we have performed a meta-analysis to pool all published data on electronic databases with the purpose to clarify the potential relationship. According to the inclusion and exclusion criteria, 18 independent studies with more than 2796 cases were included. As a result, high birth weight was found to increase the risk for bone tumor with an Odds Ratio (OR of 1.13, with the 95% confidence interval (95% CI ranging from 1.01 to 1.27. The OR of bone tumor for an increase of 500 gram of birth weight was 1.01 (95% CI 1.00–1.02; p = 0.048 for linear trend. Interestingly, individuals with high birth weight had a greater risk for osteosarcoma (OR = 1.22, 95% CI 1.06–1.40, p = 0.006 than those with normal birth weight. In addition, in the subgroup analysis by geographical region, elevated risk was detected among Europeans (OR = 1.14, 95% CI 1.00–1.29, p = 0.049. The present meta-analysis supported a positive association between high birth weight and bone tumor risk.

  4. Increased bone marrow uptake of gallium-67 in patients with fever of unknown origin

    International Nuclear Information System (INIS)

    Flores, L.G.; Jinnouchi, S.; Nagamachi, S.; Ohnishi, T.; Futami, S.; Watanabe, K.

    1996-01-01

    Purpose of the study: we studied the relationships of clinical diagnosis, the effect of blood chemistry and the clinical implication of increased gallium-67 in the bone marrow of patients presenting signs and symptoms of FUO. Materials and Methods: Based on intensity of gallium-67 uptake in bone marrow, patients were classified as follows: Type 1 when there is no evidence or very faint bone marrow uptake in vertebrae, Type 2 when mild to moderate, Type 3 when uptake is severe. The relationships of white blood cell count (WBC), hemoglobin concentration, hematocrit count, serum iron and unsaturated iron biding capacity (UIBC) with the occurrence of increased bone marrow uptake in the different groups were noted. Analysis of variance with Fishers Protected Least Significant Difference was used. A.p. value less than 0.05 was considered significant. Results: The results showed significant differences between Types 1 and 2 and between Type 1 and 3 for WBC counts, serum hemoglobin and serum hematocrit level. Serum iron concentration and UIBC however, did not show any significant differences. Conclusion: Significant changes in WBC count, Hb concentration and Hct count in FUO patients were accompanied by varying intensity of gallium-67 uptake in the bone marrow. (author)

  5. Zoledronic acid preserves bone structure and increases survival but does not limit tumour incidence in a prostate cancer bone metastasis model.

    Directory of Open Access Journals (Sweden)

    Tzong-Tyng Hung

    Full Text Available BACKGROUND: The bisphosphonate, zoledronic acid (ZOL, can inhibit osteoclasts leading to decreased osteoclastogenesis and osteoclast activity in bone. Here, we used a mixed osteolytic/osteoblastic murine model of bone-metastatic prostate cancer, RM1(BM, to determine how inhibiting osteolysis with ZOL affects the ability of these cells to establish metastases in bone, the integrity of the tumour-bearing bones and the survival of the tumour-bearing mice. METHODS: The model involves intracardiac injection for arterial dissemination of the RM1(BM cells in C57BL/6 mice. ZOL treatment was given via subcutaneous injections on days 0, 4, 8 and 12, at 20 and 100 µg/kg doses. Bone integrity was assessed by micro-computed tomography and histology with comparison to untreated mice. The osteoclast and osteoblast activity was determined by measuring serum tartrate-resistant acid phosphatase 5b (TRAP 5b and osteocalcin, respectively. Mice were euthanased according to predetermined criteria and survival was assessed using Kaplan Meier plots. FINDINGS: Micro-CT and histological analysis showed that treatment of mice with ZOL from the day of intracardiac injection of RM1(BM cells inhibited tumour-induced bone lysis, maintained bone volume and reduced the calcification of tumour-induced endochondral osteoid material. ZOL treatment also led to a decreased serum osteocalcin and TRAP 5b levels. Additionally, treated mice showed increased survival compared to vehicle treated controls. However, ZOL treatment did not inhibit the cells ability to metastasise to bone as the number of bone-metastases was similar in both treated and untreated mice. CONCLUSIONS: ZOL treatment provided significant benefits for maintaining the integrity of tumour-bearing bones and increased the survival of tumour bearing mice, though it did not prevent establishment of bone-metastases in this model. From the mechanistic view, these observations confirm that tumour-induced bone lysis is not a

  6. Theoretical effects of fully ductile versus fully brittle behaviors of bone tissue on the strength of the human proximal femur and vertebral body.

    Science.gov (United States)

    Nawathe, Shashank; Yang, Haisheng; Fields, Aaron J; Bouxsein, Mary L; Keaveny, Tony M

    2015-05-01

    The influence of the ductility of bone tissue on whole-bone strength represents a fundamental issue of multi-scale biomechanics. To gain insight, we performed a computational study of 16 human proximal femurs and 12 T9 vertebral bodies, comparing the whole-bone strength for the two hypothetical bounding cases of fully brittle versus fully ductile tissue-level failure behaviors, all other factors, including tissue-level elastic modulus and yield stress, held fixed. For each bone, a finite element model was generated (60-82 μm element size; up to 120 million elements) and was virtually loaded in habitual (stance for femur, compression for vertebra) and non-habitual (sideways fall, only for femur) loading modes. Using a geometrically and materially non-linear model, the tissue was assumed to be either fully brittle or fully ductile. We found that, under habitual loading, changing the tissue behavior from fully ductile to fully brittle reduced whole-bone strength by 38.3±2.4% (mean±SD) and 39.4±1.9% for the femur and vertebra, respectively (p=0.39 for site difference). These reductions were remarkably uniform across bones, but (for the femur) were greater for non-habitual (57.1±4.7%) than habitual loading (pductile cases. These theoretical results suggest that the whole-bone strength of the proximal femur and vertebra can vary substantially between fully brittle and fully ductile tissue-level behaviors, an effect that is relatively insensitive to bone morphology but greater for non-habitual loading. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Manganese Supplementation in Deer under Balanced Diet Increases Impact Energy and Contents in Minerals of Antler Bone Tissue.

    Directory of Open Access Journals (Sweden)

    Jamil Cappelli

    Full Text Available Bone ash, collagen, Ca and P composition, are considered the main factors affecting mechanical properties in bones. However, a series of studies in bone and antler have shown that some trace minerals, such as manganese, may play a role whose importance exceeds what may be expected considering their low content. A previous study showed that a reduction in manganese in antlers during a year of late winter frosts led to generalized antler breakage in Spain, which included a reduction of 30% of cortical thickness, 27% reduction in impact energy, and 10% reduction in work to peak force. Starting for this observation, we experimentally studied the effects of manganese supplementation in adults and yearling (yearlings red deer under a balanced diet. Subjects were 29 deer of different age classes (adult n = 19, yearlings n = 10 that were divided in a manganese injected group (n = 14 and a control group (n = 15. Antler content in ashes and minerals, intrinsic mechanical properties and cross section structure were examined at 4 points along the antler beam. A one way ANOVA (mean per antler showed that in yearlings, manganese supplementation only increased its content and that of Fe. However, in adults, Mn supplementation increased the mean content per antler of Ca, Na, P, B, Co, Cu, K, Mn, Ni, Se (while Si content was reduced, and impact work but not Young's modulus of elasticity, bending strength or work to peak force. A GLM series on characteristics in the uppermost part examined in the antler, often showing physiological exhaustion and depletion of body stores, showed also a 16% increase in work to peak force in the antlers of the treated group. Thus, manganese supplementation altered mineral composition of antler and improved structure and some mechanical properties despite animals having a balanced diet.

  8. Manganese Supplementation in Deer under Balanced Diet Increases Impact Energy and Contents in Minerals of Antler Bone Tissue.

    Science.gov (United States)

    Cappelli, Jamil; Garcia, Andrés; Ceacero, Francisco; Gomez, Santiago; Luna, Salvador; Gallego, Laureano; Gambin, Pablo; Landete-Castillejos, Tomás

    2015-01-01

    Bone ash, collagen, Ca and P composition, are considered the main factors affecting mechanical properties in bones. However, a series of studies in bone and antler have shown that some trace minerals, such as manganese, may play a role whose importance exceeds what may be expected considering their low content. A previous study showed that a reduction in manganese in antlers during a year of late winter frosts led to generalized antler breakage in Spain, which included a reduction of 30% of cortical thickness, 27% reduction in impact energy, and 10% reduction in work to peak force. Starting for this observation, we experimentally studied the effects of manganese supplementation in adults and yearling (yearlings) red deer under a balanced diet. Subjects were 29 deer of different age classes (adult n = 19, yearlings n = 10) that were divided in a manganese injected group (n = 14) and a control group (n = 15). Antler content in ashes and minerals, intrinsic mechanical properties and cross section structure were examined at 4 points along the antler beam. A one way ANOVA (mean per antler) showed that in yearlings, manganese supplementation only increased its content and that of Fe. However, in adults, Mn supplementation increased the mean content per antler of Ca, Na, P, B, Co, Cu, K, Mn, Ni, Se (while Si content was reduced), and impact work but not Young's modulus of elasticity, bending strength or work to peak force. A GLM series on characteristics in the uppermost part examined in the antler, often showing physiological exhaustion and depletion of body stores, showed also a 16% increase in work to peak force in the antlers of the treated group. Thus, manganese supplementation altered mineral composition of antler and improved structure and some mechanical properties despite animals having a balanced diet.

  9. An attempt to explain strength increase due to high loading rates

    International Nuclear Information System (INIS)

    Eibl, J.; Curbach, M.

    1989-01-01

    Most materials such as steel, concrete, ceramics, polymers, etc. show an increase of strength due to high loading rates. A number of mathematical equations are available to describe this behaviour. Nevertheless the physical reasons for these observations are still unknown. The common behaviour of a number of materials leads to the assumption that at least some explanations are material independent. Due to this reason the results of the research done at the Institute for Concrete Structures in Karlsruhe are presented in this paper to furnish new ideas for the material research due to dynamic loading. (orig.)

  10. Anti-myostatin antibody increases muscle mass and strength and improves insulin sensitivity in old mice.

    Science.gov (United States)

    Camporez, João-Paulo G; Petersen, Max C; Abudukadier, Abulizi; Moreira, Gabriela V; Jurczak, Michael J; Friedman, Glenn; Haqq, Christopher M; Petersen, Kitt Falk; Shulman, Gerald I

    2016-02-23

    Sarcopenia, or skeletal muscle atrophy, is a debilitating comorbidity of many physiological and pathophysiological processes, including normal aging. There are no approved therapies for sarcopenia, but the antihypertrophic myokine myostatin is a potential therapeutic target. Here, we show that treatment of young and old mice with an anti-myostatin antibody (ATA 842) for 4 wk increased muscle mass and muscle strength in both groups. Furthermore, ATA 842 treatment also increased insulin-stimulated whole body glucose metabolism in old mice, which could be attributed to increased insulin-stimulated skeletal muscle glucose uptake as measured by a hyperinsulinemic-euglycemic clamp. Taken together, these studies provide support for pharmacological inhibition of myostatin as a potential therapeutic approach for age-related sarcopenia and metabolic disease.

  11. Mesenchymal stem cells from cortical bone demonstrate increased clonal incidence, potency, and developmental capacity compared to their bone marrow–derived counterparts

    Directory of Open Access Journals (Sweden)

    Daniel Blashki

    2016-08-01

    Full Text Available In this study, we show that matrix dense cortical bone is the more potent compartment of bone than bone marrow as a stromal source for mesenchymal stem cells as isolated from adult rats. Lineage-depleted cortical bone-mesenchymal stem cells demonstrated >150-fold enrichment of colony forming unit–fibroblasts per cell incidence. compared to lineage-depleted bone marrow-mesenchymal stem cells, corresponding to a 70-fold increase in absolute recovered colony forming unit–fibroblasts. The composite phenotype Lin−/CD45−/CD31−/VLA-1+/Thy-1+ enriched for clonogenic mesenchymal stem cells solely from cortical bone–derived cells from which 70% of clones spontaneously differentiated into all lineages of bone, cartilage, and adipose. Both populations generated vascularized bone tissue within subcutaneous implanted collagen scaffolds; however, cortical bone–derived cells formed significantly more osteoid than bone marrow counterparts, quantified by histology. The data demonstrate that our isolation protocol identifies and validates mesenchymal stem cells with superior clonal, proliferative, and developmental potential from cortical bone compared to the bone marrow niche although marrow persists as the typical source for mesenchymal stem cells both in the literature and current pre-clinical therapies.

  12. Urbanization of black South African women may increase risk of low bone mass due to low vitamin D status, low calcium intake and high bone turnover

    OpenAIRE

    Kruger, Annamarie; Kruger, Marlena C.; Kruger, Iolanthé Marike; Wentzel-Viljoen, Edelweiss

    2011-01-01

    Globally, rural to urban migration is accompanied by changes in dietary patterns and lifestyle that have serious health implications, including development of low bone mass. We hypothesized that serum 25 (OH) vitamin D3 (25[OH]D3) levels will be lower, bone turnover higher, and nutrition inadequate in urban postmenopausal black women, increasing risk for low bone mass. We aimed to assess the prevalence of risk factors for low bone mass in 1261 black women from rural and urban areas in the Nor...

  13. ANODAL TRANSCRANIAL DIRECT CURRENT STIMULATION (TDCS) INCREASES ISOMETRIC STRENGTH OF SHOULDER ROTATORS MUSCLES IN HANDBALL PLAYERS.

    Science.gov (United States)

    Hazime, Fuad Ahmad; da Cunha, Ronaldo Alves; Soliaman, Renato Rozenblit; Romancini, Ana Clara Bezerra; Pochini, Alberto de Castro; Ejnisman, Benno; Baptista, Abrahão Fontes

    2017-06-01

    Weakness of the rotator cuff muscles can lead to imbalances in the strength of shoulder external and internal rotators, change the biomechanics of the glenohumeral joint and predispose an athlete to injury. Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation technique that has demonstrated promising results in a variety of health conditions. However few studies addressed its potential approach in the realm of athletics. The purpose of this study was to investigate if transcranial direct current stimulation (tDCS) technique increases the isometric muscle strength of shoulder external and internal rotators in handball athletes. Randomized, double-blind, placebo-controlled, crossover study. Eight female handball players aged between 17 and 21 years (Mean=19.65; SD=2.55) with 7.1 ± 4.8 years of experience in training, participating in regional and national competitions were recruited. Maximal voluntary isometric contraction (MVIC) of shoulder external and internal rotator muscles was evaluated during and after 30 and 60 minutes post one session of anodal and sham current (2mA; 0.057mA/cm 2 ) with a one-week interval between stimulations. Compared to baseline, MVIC of shoulder external and internal rotators significantly increased after real but not sham tDCS. Between-group differences were observed for external and internal rotator muscles. Maximal voluntary isometric contraction of external rotation increased significantly during tDCS, and 30 and 60 minutes post-tDCS for real tDCS compared to that for sham tDCS. For internal rotation MVIC increased significantly during and 60 minutes post-tDCS. The results indicate that transcranial direct current stimulation temporarily increases maximal isometric contractions of the internal and external rotators of the shoulder in handball players. 2.

  14. Increased resistance during jump exercise does not enhance cortical bone formation.

    Science.gov (United States)

    Boudreaux, Ramon D; Swift, Joshua M; Gasier, Heath G; Wiggs, Michael P; Hogan, Harry A; Fluckey, James D; Bloomfield, Susan A

    2014-01-01

    This study sought to elucidate the effects of a low- and high-load jump resistance exercise (RE) training protocol on cortical bone of the tibia and femur mid-diaphyses. Sprague-Dawley rats (male, 6 months old) were randomly assigned to high-load RE (HRE; n = 16), low-load RE (LRE; n = 15), or cage control (CC; n = 11) groups. Animals in the HRE and LRE groups performed 15 sessions of jump RE for 5 wk. Load in the HRE group was progressively increased from 80 g added to a weighted vest (50 repetitions) to 410 g (16 repetitions). The LRE rats completed the same protocol as the HRE group (same number of repetitions), with only a 30-g vest applied. Low- and high-load jump RE resulted in 6%-11% higher cortical bone mineral content and cortical bone area compared with controls, as determined by in vivo peripheral quantitative computed tomography measurements. In the femur, however, only LRE demonstrated improvements in cortical volumetric bone mineral density (+11%) and cross-sectional moment of inertia (+20%) versus the CC group. The three-point bending to failure revealed a marked increase in tibial maximum force (25%-29%), stiffness (19%-22%), and energy to maximum force (35%-55%) and a reduction in elastic modulus (-11% to 14%) in both LRE and HRE compared with controls. Dynamic histomorphometry assessed at the tibia mid-diaphysis determined that both LRE and HRE resulted in 20%-30% higher periosteal mineralizing surface versus the CC group. Mineral apposition rate and bone formation rate were significantly greater in animals in the LRE group (27%, 39%) than those in the HRE group. These data demonstrate that jump training with minimal loading is equally, and sometimes more, effective at augmenting cortical bone integrity compared with overload training in skeletally mature rats.

  15. Effects of increased collagen-matrix density on the mechanical properties and in vivo absorbability of hydroxyapatite-collagen composites as artificial bone materials

    Energy Technology Data Exchange (ETDEWEB)

    Yunoki, Shunji [Life Science Group, Tokyo Metropolitan Industrial Technology Research Institute, 2-11-1 Fukasawa, Setagaya-ku, Tokyo 158-0081 (Japan); Sugiura, Hiroaki; Kondo, Eiji; Yasuda, Kazunori [Department of Sports Medicine and Joint Surgery, Graduate School of Medicine, Hokkaido University, Kita-15 Nishi-7, Sapporo, Hokkaido 060-8638 Japan (Japan); Ikoma, Toshiyuki; Tanaka, Junzo, E-mail: yunoki.shunji@iri-tokyo.jp [Department of Metallurgy and Ceramics Science, 2-12-1-S7-1, Ookayama, Meguro-ku, Tokyo 152-8550 (Japan)

    2011-02-15

    The aim of this study was to evaluate the effects of increased collagen-matrix density on the mechanical properties and in vivo absorbability of porous hydroxyapatite (HAp)-collagen composites as artificial bone materials. Seven types of porous HAp-collagen composites were prepared from HAp nanocrystals and dense collagen fibrils. Their densities and HAp/collagen weight ratios ranged from 122 to 331 mg cm{sup -3} and from 20/80 to 80/20, respectively. The flexural modulus and strength increased with an increase in density, reaching 2.46 {+-} 0.48 and 0.651 {+-} 0.103 MPa, respectively. The porous composites with a higher collagen-matrix density exhibited much higher mechanical properties at the same densities, suggesting that increasing the collagen-matrix density is an effective way of improving the mechanical properties. It was also suggested that other structural factors in addition to collagen-matrix density are required to achieve bone-like mechanical properties. The in vivo absorbability of the composites was investigated in bone defects of rabbit femurs, demonstrating that the absorption rate decreased with increases in the composite density. An exhaustive increase in density is probably limited by decreases in absorbability as artificial bones.

  16. Effects of increased collagen-matrix density on the mechanical properties and in vivo absorbability of hydroxyapatite-collagen composites as artificial bone materials

    International Nuclear Information System (INIS)

    Yunoki, Shunji; Sugiura, Hiroaki; Kondo, Eiji; Yasuda, Kazunori; Ikoma, Toshiyuki; Tanaka, Junzo

    2011-01-01

    The aim of this study was to evaluate the effects of increased collagen-matrix density on the mechanical properties and in vivo absorbability of porous hydroxyapatite (HAp)-collagen composites as artificial bone materials. Seven types of porous HAp-collagen composites were prepared from HAp nanocrystals and dense collagen fibrils. Their densities and HAp/collagen weight ratios ranged from 122 to 331 mg cm -3 and from 20/80 to 80/20, respectively. The flexural modulus and strength increased with an increase in density, reaching 2.46 ± 0.48 and 0.651 ± 0.103 MPa, respectively. The porous composites with a higher collagen-matrix density exhibited much higher mechanical properties at the same densities, suggesting that increasing the collagen-matrix density is an effective way of improving the mechanical properties. It was also suggested that other structural factors in addition to collagen-matrix density are required to achieve bone-like mechanical properties. The in vivo absorbability of the composites was investigated in bone defects of rabbit femurs, demonstrating that the absorption rate decreased with increases in the composite density. An exhaustive increase in density is probably limited by decreases in absorbability as artificial bones.

  17. Balancing mechanical strength with bioactivity in chitosan-calcium phosphate 3D microsphere scaffolds for bone tissue engineering: air- vs. freeze-drying processes.

    Science.gov (United States)

    Nguyen, D T; McCanless, J D; Mecwan, M M; Noblett, A P; Haggard, W O; Smith, R A; Bumgardner, J D

    2013-01-01

    The objective of this study was to evaluate the potential benefit of 3D composite scaffolds composed of chitosan and calcium phosphate for bone tissue engineering. Additionally, incorporation of mechanically weak lyophilized microspheres within those air-dried (AD) was considered for enhanced bioactivity. AD microsphere, alone, and air- and freeze-dried microsphere (FDAD) 3D scaffolds were evaluated in vitro using a 28-day osteogenic culture model with the Saos-2 cell line. Mechanical testing, quantitative microscopy, and lysozyme-driven enzymatic degradation of the scaffolds were also studied. FDAD scaffold showed a higher concentration (p < 0.01) in cells per scaffold mass vs. AD constructs. Collagen was ∼31% greater (p < 0.01) on FDAD compared to AD scaffolds not evident in microscopy of microsphere surfaces. Alternatively, AD scaffolds demonstrated a superior threefold increase in compressive strength over FDAD (12 vs. 4 MPa) with minimal degradation. Inclusion of FD spheres within the FDAD scaffolds allowed increased cellular activity through improved seeding, proliferation, and extracellular matrix production (as collagen), although mechanical strength was sacrificed through introduction of the less stiff, porous FD spheres.

  18. Combining areal DXA bone mineral density and vertebrae postero-anterior width improves the prediction of vertebral strength

    Energy Technology Data Exchange (ETDEWEB)

    Taton, Grzegorz; Rokita, Eugeniusz [Jagiellonian University Medical College, Department of Biophysics, Krakow (Poland); Wrobel, Andrzej [Jagiellonian University, Institute of Physics, Krakow (Poland); Korkosz, Mariusz [Jagiellonian University Medical College, Department of Internal Medicine and Gerontology, Division of Rheumatology, Krakow (Poland)

    2013-12-15

    Areal bone mineral density (aBMD) measured by dual-energy X-ray absorptiometry (DXA) is an important determinant of bone strength (BS), despite the fact that the correlation between aBMD and BS is relatively weak. Parameters that describe BS more accurately are desired. The aim of this study was to determine whether the geometrical corrections applied to aBMD would improve its ability for BS prediction. We considered new parameters, estimated from a single DXA measurement, as well as BMAD (bone mineral apparent density) reported in the literature. In vitro studies were performed with the L3 vertebrae from 20 cadavers, which were studied with DXA and quantitative computed tomography (QCT). A mechanical strength assessment was carried out. Two new parameters were introduced: vBMD{sub min} = (aBMD)/(W{sub PA}{sup min}) and vBMD{sub av} = (aBMD)/(W{sub PA}{sup av}) (W{sub PA}{sup min} - minimal vertebral body width in postero-anterior (PA) view, W{sub PA}{sup av} - average PA vertebral body width). Volumetric BMD measured by QCT (vBMD), aBMD, BMAD, vBMD{sub min}, and vBMD{sub av} were correlated to ultimate load and ultimate stress (P{sub max}) to find the best predictor of vertebrae BS. The coefficients of correlation between P{sub max} and vBMD{sub min}, vBMD{sub av}, as well as BMAD, were r = 0.626 (p = 0.005), r = 0.610 (p = 0.006) and r = 0.567 (p = 0.012), respectively. Coefficients for vBMD and aBMD are r = 0.648 (p = 0.003) and r = 0.511 (p = 0.03), respectively. Our results showed that aBMD normalized by vertebrae dimensions describes vertebrae BS better than aBMD alone. The considered indices vBMD{sub av}, vBMD{sub min}, and BMAD can be measured in routine PA DXA and considerably improve BS variability prediction. vBMD{sub min} is superior compared to vBMD{sub av} and BMAD. (orig.)

  19. Bone and fat connection in aging bone.

    Science.gov (United States)

    Duque, Gustavo

    2008-07-01

    The fat and bone connection plays an important role in the pathophysiology of age-related bone loss. This review will focus on the age-induced mechanisms regulating the predominant differentiation of mesenchymal stem cells into adipocytes. Additionally, bone marrow fat will be considered as a diagnostic and therapeutic approach to osteoporosis. There are two types of bone and fat connection. The 'systemic connection', usually seen in obese patients, is hormonally regulated and associated with high bone mass and strength. The 'local connection' happens inside the bone marrow. Increasing amounts of bone marrow fat affect bone turnover through the inhibition of osteoblast function and survival and the promotion of osteoclast differentiation and activation. This interaction is regulated by paracrine secretion of fatty acids and adipokines. Additionally, bone marrow fat could be quantified using noninvasive methods and could be used as a therapeutic approach due to its capacity to transdifferentiate into bone without affecting other types of fat in the body. The bone and fat connection within the bone marrow constitutes a typical example of lipotoxicity. Additionally, bone marrow fat could be used as a new diagnostic and therapeutic approach for osteoporosis in older persons.

  20. Bone impairment in phenylketonuria is characterized by circulating osteoclast precursors and activated T cell increase.

    Directory of Open Access Journals (Sweden)

    Ilaria Roato

    Full Text Available BACKGROUND: Phenylketonuria (PKU is a rare inborn error of metabolism often complicated by a progressive bone impairment of uncertain etiology, as documented by both ionizing and non- ionizing techniques. METHODOLOGY: Peripheral blood mononuclear cell (PBMC cultures were performed to study osteoclastogenesis, in the presence or absence of recombinant human monocyte-colony stimulating factor (M-CSF and receptor activator of NFκB ligand (RANKL. Flow cytometry was utilized to analyze osteoclast precursors (OCPs and T cell phenotype. Tumour necrosis factor α (TNF-α, RANKL and osteoprotegerin (OPG were quantified in cell culture supernatants by ELISA. The effects of RANKFc and anti-TNF-α antibodies were also investigated to determine their ability to inhibit osteoclastogenesis. In addition, bone conditions and phenylalanine levels in PKU patients were clinically evaluated. PRINCIPAL FINDINGS: Several in vitro studies in PKU patients' cells identified a potential mechanism of bone formation inhibition commonly associated with this disorder. First, PKU patients disclosed an increased osteoclastogenesis compared to healthy controls, both in unstimulated and M-CSF/RANKL stimulated PBMC cultures. OCPs and the measured RANKL/OPG ratio were higher in PKU patients compared to healthy controls. The addition of specific antagonist RANKFc caused osteoclastogenesis inhibition, whereas anti-TNF-α failed to have this effect. Among PBMCs isolated from PKU patients, activated T cells, expressing CD69, CD25 and RANKL were identified. Confirmatory in vivo studies support this proposed model. These in vivo studies included the analysis of osteoclastogenesis in PKU patients, which demonstrated an inverse relation to bone condition assessed by phalangeal Quantitative Ultrasound (QUS. This was also directly related to non-compliance to therapeutic diet reflected by hyperphenylalaninemia. CONCLUSIONS: Our results indicate that PKU spontaneous osteoclastogenesis

  1. Anodizing color coded anodized Ti6Al4V medical devices for increasing bone cell functions.

    Science.gov (United States)

    Ross, Alexandra P; Webster, Thomas J

    2013-01-01

    Current titanium-based implants are often anodized in sulfuric acid (H(2)SO(4)) for color coding purposes. However, a crucial parameter in selecting the material for an orthopedic implant is the degree to which it will integrate into the surrounding bone. Loosening at the bone-implant interface can cause catastrophic failure when motion occurs between the implant and the surrounding bone. Recently, a different anodization process using hydrofluoric acid has been shown to increase bone growth on commercially pure titanium and titanium alloys through the creation of nanotubes. The objective of this study was to compare, for the first time, the influence of anodizing a titanium alloy medical device in sulfuric acid for color coding purposes, as is done in the orthopedic implant industry, followed by anodizing the device in hydrofluoric acid to implement nanotubes. Specifically, Ti6Al4V model implant samples were anodized first with sulfuric acid to create color-coding features, and then with hydrofluoric acid to implement surface features to enhance osteoblast functions. The material surfaces were characterized by visual inspection, scanning electron microscopy, contact angle measurements, and energy dispersive spectroscopy. Human osteoblasts were seeded onto the samples for a series of time points and were measured for adhesion and proliferation. After 1 and 2 weeks, the levels of alkaline phosphatase activity and calcium deposition were measured to assess the long-term differentiation of osteoblasts into the calcium depositing cells. The results showed that anodizing in hydrofluoric acid after anodizing in sulfuric acid partially retains color coding and creates unique surface features to increase osteoblast adhesion, proliferation, alkaline phosphatase activity, and calcium deposition. In this manner, this study provides a viable method to anodize an already color coded, anodized titanium alloy to potentially increase bone growth for numerous implant applications.

  2. Increasing Bone Mass and Bone Strength in Individuals with Chronic Spinal Cord Injury: Maximizing Response to Therapy

    Science.gov (United States)

    2017-10-01

    5 7. Inventions, Patents and Licenses…………………………………… 5 8. Reportable Outcomes..……………………………………………… 5 9. Other Achievements………………………………………………… 5...ABSTRACTS AND PRESENTATIONS: None. INVENTIONS, PATENTS AND LICENSES: None. REPORTABLE OUTCOMES: None. OTHER ACHIEVEMENTS: None

  3. Loss of mechanical properties in vivo and bone-implant interface strength of AZ31B magnesium alloy screws with Si-containing coating.

    Science.gov (United States)

    Tan, Lili; Wang, Qiang; Lin, Xiao; Wan, Peng; Zhang, Guangdao; Zhang, Qiang; Yang, Ke

    2014-05-01

    In this study the loss of mechanical properties and the interface strength of coated AZ31B magnesium alloy (a magnesium-aluminum alloy) screws with surrounding host tissues were investigated and compared with non-coated AZ31B, degradable polymer and biostable titanium alloy screws in a rabbit animal model after 1, 4, 12 and 21weeks of implantation. The interface strength was evaluated in terms of the extraction torque required to back out the screws. The loss of mechanical properties over time was indicated by one-point bending load loss of the screws after these were extracted at different times. AZ31B samples with a silicon-containing coating had a decreased degradation rate and improved biological properties. The extraction torque of Ti6Al4V, poly-l-lactide (PLLA) and coated AZ31B increased significantly from 1week to 4weeks post-implantation, indicating a rapid osteosynthesis process over 3weeks. The extraction torque of coated AZ31B increased with implantation time, and was higher than that of PLLA after 4weeks of implantation, equalling that of Ti6Al4V at 12weeks and was higher at 21weeks. The bending loads of non-coated AZ31B and PLLA screws degraded sharply after implantation, and that of coated AZ31B degraded more slowly. The biodegradation mechanism, the coating to control the degradation rate and the bioactivity of magnesium alloys influencing the mechanical properties loss over time and bone-implant interface strength are discussed in this study and it is concluded that a suitable degradation rate will result in an improvement in the mechanical performance of magnesium alloys, making them more suitable for clinical application. Copyright © 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  4. Is the relationship between increased knee muscle strength and improved physical function following exercise dependent on baseline physical function status?

    Science.gov (United States)

    Hall, Michelle; Hinman, Rana S; van der Esch, Martin; van der Leeden, Marike; Kasza, Jessica; Wrigley, Tim V; Metcalf, Ben R; Dobson, Fiona; Bennell, Kim L

    2017-12-08

    Clinical guidelines recommend knee muscle strengthening exercises to improve physical function. However, the amount of knee muscle strength increase needed for clinically relevant improvements in physical function is unclear. Understanding how much increase in knee muscle strength is associated with improved physical function could assist clinicians in providing appropriate strength gain targets for their patients in order to optimise outcomes from exercise. The aim of this study was to investigate whether an increase in knee muscle strength is associated with improved self-reported physical function following exercise; and whether the relationship differs according to physical function status at baseline. Data from 100 participants with medial knee osteoarthritis enrolled in a 12-week randomised controlled trial comparing neuromuscular exercise to quadriceps strengthening exercise were pooled. Participants were categorised as having mild, moderate or severe physical dysfunction at baseline using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Associations between 12-week changes in physical function (dependent variable) and peak isometric knee extensor and flexor strength (independent variables) were evaluated with and without accounting for baseline physical function status and covariates using linear regression models. In covariate-adjusted models without accounting for baseline physical function, every 1-unit (Nm/kg) increase in knee extensor strength was associated with physical function improvement of 17 WOMAC units (95% confidence interval (CI) -29 to -5). When accounting for baseline severity of physical function, every 1-unit increase in knee extensor strength was associated with physical function improvement of 24 WOMAC units (95% CI -42 to -7) in participants with severe physical dysfunction. There were no associations between change in strength and change in physical function in participants with mild or moderate physical

  5. Creatine monohydrate supplementation does not increase muscle strength, lean body mass, or muscle phosphocreatine in patients with myotonic dystrophy type 1.

    Science.gov (United States)

    Tarnopolsky, Mark; Mahoney, Douglas; Thompson, Terry; Naylor, Heather; Doherty, Timothy J

    2004-01-01

    Creatine monohydrate (CrM) supplementation may increase strength in some types of muscular dystrophy. A recent study in myotonic muscular dystrophy type 1 (DM1) did not find a significant treatment effect, but measurements of muscle phosphocreatine (PCr) were not performed. We completed a randomized, double-blind, cross-over trial using 34 genetically confirmed adult DM1 patients without significant cognitive impairment. Participants received CrM (5 g, approximately 0.074 g/kg daily) and a placebo for each 4-month phase with a 6-week wash-out. Spirometry, manual muscle testing, quantitative isometric strength testing of handgrip, foot dorsiflexion, and knee extension, handgrip and foot dorsiflexion endurance, functional tasks, activity of daily living scales, body composition (total, bone, and fat-free mass), serum creatine kinase activity, serum creatinine concentration and clearance, and liver function tests were completed before and after each intervention, and muscle PCr/beta-adenosine triphosphate (ATP) ratios of the forearm flexor muscles were completed at the end of each phase. CrM supplementation did not increase any of the outcome measurements except for plasma creatinine concentration (but not creatinine clearance). Thus, CrM supplementation at 5 g daily does not have any effects on muscle strength, body composition, or activities of daily living in patients with DM1, perhaps because of a failure of the supplementation to increase muscle PCr/beta-ATP content.

  6. Increased sink strength offsets the inhibitory effect of sucrose on sugarcane photosynthesis.

    Science.gov (United States)

    Ribeiro, Rafael V; Machado, Eduardo C; Magalhães Filho, José R; Lobo, Ana Karla M; Martins, Márcio O; Silveira, Joaquim A G; Yin, Xinyou; Struik, Paul C

    2017-01-01

    Spraying sucrose inhibits photosynthesis by impairing Rubisco activity and stomatal conductance (g s ), whereas increasing sink demand by partially darkening the plant stimulates sugarcane photosynthesis. We hypothesized that the stimulatory effect of darkness can offset the inhibitory effect of exogenous sucrose on photosynthesis. Source-sink relationship was perturbed in two sugarcane cultivars by imposing partial darkness, spraying a sucrose solution (50mM) and their combination. Five days after the onset of the treatments, the maximum Rubisco carboxylation rate (V cmax ) and the initial slope of A-C i curve (k) were estimated by measuring leaf gas exchange and chlorophyll fluorescence. Photosynthesis was inhibited by sucrose spraying in both genotypes, through decreases in V cmax , k, g s and ATP production driven by electron transport (J atp ). Photosynthesis of plants subjected to the combination of partial darkness and sucrose spraying was similar to photosynthesis of reference plants for both genotypes. Significant increases in V cmax , g s and J atp and marginal increases in k were noticed when combining partial darkness and sucrose spraying compared with sucrose spraying alone. Our data also revealed that increases in sink strength due to partial darkness offset the inhibition of sugarcane photosynthesis caused by sucrose spraying, enhancing the knowledge on endogenous regulation of sugarcane photosynthesis through the source-sink relationship. Copyright © 2016 Elsevier GmbH. All rights reserved.

  7. Increase in the strength characteristics of Portland cement due to introduction of the compound mineral supplements

    Science.gov (United States)

    Il'ina, Liliia; Gichko, Nikolai; Mukhina, Irina

    2016-01-01

    At the initial phase of hardening it is the limestone component that plays a major role in the hardening process, which acts as the substrate for the crystallization of hydrate tumors due to its chemical affinity with the products of Portland cement hydration. After 7 days, the diopside supplement influences the processes more significantly. Diopside has a high modulus of elasticity compared to the cement paste. As a result, stresses are redistributed within the cement paste and the whole composition is hardened. An increase in the quantity of diopside in the compound supplement to more than 66.7% does not provide a substantial increase in the strength of the cement paste. As the hardness of diopside is higher than the hardness of limestone, much more energy is required to grind it down to a usable component. Therefore, a further increase in the quantity of diopside in the compound supplement is not economically feasible. An evaluation of the optimum quantity of input compound mineral supplements can be made based on the ideas of close packing of spherical particles and the Pauling rules. The optimum content of the supplement is 8-8.5% provided that its dispersion and density are close to the dispersion and density of the binder. An increase in the dispersion of the supplement reduces its optimal quantity.

  8. Femoral bone strength in large theropod dinosaurs: A study by genus

    Science.gov (United States)

    Lee, Scott

    2015-03-01

    The locomotion of bipedal theropod dinosaurs is controlled by the strength of the femur to resist bending torques (caused by the foot striking the ground and the action of muscles on the femur). The section modulus at the narrowest part measures the ability of the femur to resist such torques. We present the results of our study of the femoral section moduli for six genus of large theropods: Tyrannosaurus, Nanotyrannus, Gorgosaurus, and Albertosaurus of the Late Cretaceous, Acrocanthosaurus of the Early Cretaceous, and Allosaurus of the Late Jurassic. These animals had femora of lengths between 65 and 134 cm. The corresponding section moduli varied between 23 and 570 cm3. Some species of Tyrannosaurus, Gorgosaurus, Allosaurus, and Albertosaurus had femora with lengths in the same 75 to 90 cm range. The section moduli of these animals are all in the same range, showing that the animals had the same abilities of locomotion. That is, Allosaurus of the Late Jurassic could locomote just as well as the Late Cretaceous Tyrannosaurus, Gorgosaurus, and Albertosaurus. There is no evidence that these later theropods had evolved to be any faster than similarly-sized theropods living about 80 million years earlier.

  9. Increased consumer density reduces the strength of neighborhood effects in a model system.

    Science.gov (United States)

    Merwin, Andrew C; Underwood, Nora; Inouye, Brian D

    2017-11-01

    An individual's susceptibility to attack can be influenced by conspecific and heterospecifics neighbors. Predicting how these neighborhood effects contribute to population-level processes such as competition and evolution requires an understanding of how the strength of neighborhood effects is modified by changes in the abundances of both consumers and neighboring resource species. We show for the first time that consumer density can interact with the density and frequency of neighboring organisms to determine the magnitude of neighborhood effects. We used the bean beetle, Callosobruchus maculatus, and two of its host beans, Vigna unguiculata and V. radiata, to perform a response-surface experiment with a range of resource densities and three consumer densities. At low beetle density, damage to beans was reduced with increasing conspecific density (i.e., resource dilution) and damage to the less preferred host, V. unguiculata, was reduced with increasing V. radiata frequency (i.e., frequency-dependent associational resistance). As beetle density increased, however, neighborhood effects were reduced; at the highest beetle densities neither focal nor neighboring resource density nor frequency influenced damage. These findings illustrate the importance of consumer density in mediating indirect effects among resources, and suggest that accounting for consumer density may improve our ability to predict population-level outcomes of neighborhood effects and our use of them in applications such as mixed-crop pest management. © 2017 by the Ecological Society of America.

  10. Increasing Dietary Phosphorus Intake from Food Additives: Potential for Negative Impact on Bone Health123

    OpenAIRE

    Takeda, Eiji; Yamamoto, Hironori; Yamanaka-Okumura, Hisami; Taketani, Yutaka

    2014-01-01

    It is important to consider whether habitual high phosphorus intake adversely affects bone health, because phosphorus intake has been increasing, whereas calcium intake has been decreasing in dietary patterns. A higher total habitual dietary phosphorus intake has been associated with higher serum parathyroid hormone (PTH) and lower serum calcium concentrations in healthy individuals. Higher serum PTH concentrations have been shown in those who consume foods with phosphorus additives. These fi...

  11. Soccer increases bone mass in prepubescent boys during growth: a 3-yr longitudinal study.

    Science.gov (United States)

    Zouch, Mohamed; Zribi, Anis; Alexandre, Christian; Chaari, Hamada; Frere, Delphine; Tabka, Zouhair; Vico, Laurence

    2015-01-01

    The aim of this study was to examine the effect of 3-yr soccer practice on bone acquisition in prepubescent boys. We investigated 65 boys (aged 10-13 yr, Tanner stage I) at baseline, among which only 40 boys (Tanner stages II and III) have continued the 3-yr follow-up: 23 soccer players (F) completed 2-5 h of training plus 1 competition game per week and 17 controls (C). Bone mineral density (BMD, g/cm(2)) and bone mineral content (BMC, g) were measured by dual-energy X-ray absorptiometry at different sites. At baseline, BMD was higher in soccer players than in controls in the whole body and legs. In contrast, there was nonsignificant difference BMD in head, femoral neck, arms, and BMC in all measured sites between groups. At 3-yr follow-up, soccer players were found to have higher BMD and BMC at all sites than controls, except for head BMD and BMC and arms BMC in which the difference was nonsignificant between groups. During the 3-yr follow-up, the soccer players were found to gain significantly more in lumbar spine (31.2% ± 2.9% vs 23.9% ± 2.1%; p soccer players have less %BMD and %BMC changes in the head than controls. A nonsignificant difference was found in legs, dominant arm, head %BMD and %BMC changes, and whole-body %BMC changes between groups. In summary, we suggest that soccer has an osteogenic effect BMD and BMC in loaded sites in pubertal soccer players. The increased bone mass induced by soccer training in the stressed sites was associated to a decreased skull bone mass after 3 yr of follow-up. Copyright © 2015 The International Society for Clinical Densitometry. Published by Elsevier Inc. All rights reserved.

  12. Is cortical bone hip? What determines cortical bone properties?

    Science.gov (United States)

    Epstein, Sol

    2007-07-01

    Increased bone turnover may produce a disturbance in bone structure which may result in fracture. In cortical bone, both reduction in turnover and increase in hip bone mineral density (BMD) may be necessary to decrease hip fracture risk and may require relatively greater proportionate changes than for trabecular bone. It should also be noted that increased porosity produces disproportionate reduction in bone strength, and studies have shown that increased cortical porosity and decreased cortical thickness are associated with hip fracture. Continued studies for determining the causes of bone strength and deterioration show distinct promise. Osteocyte viability has been observed to be an indicator of bone strength, with viability as the result of maintaining physiological levels of loading and osteocyte apoptosis as the result of a decrease in loading. Osteocyte apoptosis and decrease are major factors in the bone loss and fracture associated with aging. Both the osteocyte and periosteal cell layer are assuming greater importance in the process of maintaining skeletal integrity as our knowledge of these cells expand, as well being a target for pharmacological agents to reduce fracture especially in cortical bone. The bisphosphonate alendronate has been seen to have a positive effect on cortical bone by allowing customary periosteal growth, while reducing the rate of endocortical bone remodeling and slowing bone loss from the endocortical surface. Risedronate treatment effects were attributed to decrease in bone resorption and thus a decrease in fracture risk. Ibandronate has been seen to increase BMD as the spine and femur as well as a reduced incidence of new vertebral fractures and non vertebral on subset post hoc analysis. And treatment with the anabolic agent PTH(1-34) documented modeling and remodelling of quiescent and active bone surfaces. Receptor activator of nuclear factor kappa B ligand (RANKL) plays a key role in bone destruction, and the human monoclonal

  13. Enhancement of mechanical strength of TiO2/high-density polyethylene composites for bone repair with silane-coupling treatment

    International Nuclear Information System (INIS)

    Hashimoto, Masami; Takadama, Hiroaki; Mizuno, Mineo; Kokubo, Tadashi

    2006-01-01

    Mechanical properties of composites made up of high-density polyethylene (HDPE) and silanated TiO 2 particles for use as a bone-repairing material were investigated in comparison with those of the composites of HDPE with unsilanized TiO 2 particles. The interfacial morphology and interaction between silanated TiO 2 and HDPE were analyzed by means of Fourier transform infrared (FT-IR) spectroscopy and scanning electron microscopy (SEM). The absorption in spectral bands related to the carboxyl bond in the silane-coupling agent, the vinyl group in the HDPE, and the formation of the ether bond was studied in order to assess the influence of the silane-coupling agent. The SEM micrograph showed that the 'bridging effect' between HDPE and TiO 2 was brought about by the silane-coupling agent. The use of the silane-coupling agent and the increase of the hot-pressing pressure for shaping the composites facilitated the penetration of polymer into cavities between individual TiO 2 particles, which increased the density of the composite. Therefore, mechanical properties such as bending yield strength and Young's modulus increased from 49 MPa and 7.5 GPa to 65 MPa and 10 GPa, respectively, after the silane-coupling treatment and increase in the hot-pressing pressure

  14. Anodizing color coded anodized Ti6Al4V medical devices for increasing bone cell functions

    Directory of Open Access Journals (Sweden)

    Webster TJ

    2013-01-01

    Full Text Available Alexandra P Ross, Thomas J WebsterSchool of Engineering and Department of Orthopedics, Brown University, Providence, RI, USAAbstract: Current titanium-based implants are often anodized in sulfuric acid (H2SO4 for color coding purposes. However, a crucial parameter in selecting the material for an orthopedic implant is the degree to which it will integrate into the surrounding bone. Loosening at the bone–implant interface can cause catastrophic failure when motion occurs between the implant and the surrounding bone. Recently, a different anodization process using hydrofluoric acid has been shown to increase bone growth on commercially pure titanium and titanium alloys through the creation of nanotubes. The objective of this study was to compare, for the first time, the influence of anodizing a titanium alloy medical device in sulfuric acid for color coding purposes, as is done in the orthopedic implant industry, followed by anodizing the device in hydrofluoric acid to implement nanotubes. Specifically, Ti6Al4V model implant samples were anodized first with sulfuric acid to create color-coding features, and then with hydrofluoric acid to implement surface features to enhance osteoblast functions. The material surfaces were characterized by visual inspection, scanning electron microscopy, contact angle measurements, and energy dispersive spectroscopy. Human osteoblasts were seeded onto the samples for a series of time points and were measured for adhesion and proliferation. After 1 and 2 weeks, the levels of alkaline phosphatase activity and calcium deposition were measured to assess the long-term differentiation of osteoblasts into the calcium depositing cells. The results showed that anodizing in hydrofluoric acid after anodizing in sulfuric acid partially retains color coding and creates unique surface features to increase osteoblast adhesion, proliferation, alkaline phosphatase activity, and calcium deposition. In this manner, this study

  15. Marginal bone loss and dental implant failure may be increased in smokers.

    Science.gov (United States)

    Veitz-Keenan, Analia

    2016-03-01

    difference in marginal bone loss favouring the non-smoking group (SMD 0.49, 95% CI 0.07-0.90). There was an increase in marginal bone loss in the maxillae of smokers compared to the mandible (SMD 0.40, 95% CI 0.24-0.55) and a statically significant difference in implant failure in favour of the non-smoking group OR 1.96, 95% CI 1.68-2.30. The risk of marginal bone loss and implant failure is increased in smokers compared to non-smokers, however, the results should be interpreted with caution since the data from the review are provided by retrospective and cohort studies.

  16. Osteoblast-targeted overexpression of TAZ increases bone mass in vivo.

    Directory of Open Access Journals (Sweden)

    Jae-Yeon Yang

    Full Text Available Osteoblasts are derived from mesenchymal progenitors. Differentiation to osteoblasts and adipocytes is reciprocally regulated. Transcriptional coactivator with a PDZ-binding motif (TAZ is a transcriptional coactivator that induces differentiation of mesenchymal cells into osteoblasts while blocking differentiation into adipocytes. To investigate the role of TAZ on bone metabolism in vivo, we generated transgenic mice that overexpress TAZ under the control of the procollagen type 1 promoter (Col1-TAZ. Whole body bone mineral density (BMD of 6- to 19-week-old Col-TAZ mice was 4% to 7% higher than that of their wild-type (WT littermates, whereas no difference was noticed in Col.1-TAZ female mice. Microcomputed tomography analyses of proximal tibiae at 16 weeks of age demonstrated a significant increase in trabecular bone volume (26.7% and trabecular number (26.6% with a reciprocal decrease in trabecular spacing (14.2% in Col1-TAZ mice compared with their WT littermates. In addition, dynamic histomorphometric analysis of the lumbar spine revealed increased mineral apposition rate (42.8% and the serum P1NP level was also significantly increased (53% in Col.1-TAZ mice. When primary calvaria cells were cultured in osteogenic medium, alkaline phosphatase (ALP activity was significantly increased and adipogenesis was significantly suppressed in Col1-TAZ mice compared with their WT littermates. Quantitative real-time polymerase chain reaction analyses showed that expression of collagen type 1, bone sialoprotein, osteocalcin, ALP, osterix, and Runx2 was significantly increased in calvaria cells from Col1-TAZ mice compared to their WT littermates. In vitro, TAZ enhanced Runx2-mediated transcriptional activity while suppressing the peroxisome proliferator-activated receptor gamma signaling pathway. TAZ also enhanced transcriptional activity from 3TP-Lux, which reflects transforming growth factor-beta (TGF-β-mediated signaling. In addition, TAZ enhanced TGF

  17. The effects of prostaglandin E2 in growing rats - Increased metaphyseal hard tissue and cortico-endosteal bone formation

    Science.gov (United States)

    Jee, W. S. S.; Ueno, K.; Deng, Y. P.; Woodbury, D. M.

    1985-01-01

    The role of in vivo prostaglandin E2 (PGE2) in bone formation is investigated. Twenty-five male Sprague-Dawley rats weighing between 223-267 g were injected subcutaneously with 0.3, 1.0, 3.0, and 6.0 mg of PGE2-kg daily for 21 days. The processing of the tibiae for observation is described. Radiographs and histomorphometric analyses are also utilized to study bone formation. Body weight, weights of soft tissues and bones morphometry are evaluated. It is observed that PGE2 depressed longitudinal bone growth, increased growth cartilage thickness, decreased degenerative cartilage cell size and cartilage cell production, and significantly increased proximal tibial metaphyseal hard tissue mass. The data reveal that periosteal bone formation is slowed down at higher doses of PGE2 and endosteal bone formation is slightly depressed less than 10 days post injection; however, here is a late increase (10 days after post injection) in endosteal bone formation and in the formation of trabecular bone in the marrow cavity of the tibial shaft. It is noted that the effects of PGE2 on bone formation are similar to the responses of weaning rats to PGE2.

  18. Increasing dietary phosphorus intake from food additives: potential for negative impact on bone health.

    Science.gov (United States)

    Takeda, Eiji; Yamamoto, Hironori; Yamanaka-Okumura, Hisami; Taketani, Yutaka

    2014-01-01

    It is important to consider whether habitual high phosphorus intake adversely affects bone health, because phosphorus intake has been increasing, whereas calcium intake has been decreasing in dietary patterns. A higher total habitual dietary phosphorus intake has been associated with higher serum parathyroid hormone (PTH) and lower serum calcium concentrations in healthy individuals. Higher serum PTH concentrations have been shown in those who consume foods with phosphorus additives. These findings suggest that long-term dietary phosphorus loads and long-term hyperphosphatemia may have important negative effects on bone health. In contrast, PTH concentrations did not increase as a result of high dietary phosphorus intake when phosphorus was provided with adequate amounts of calcium. Intake of foods with a ratio of calcium to phosphorus close to that found in dairy products led to positive effects on bone health. Several randomized controlled trials have shown positive relations between dairy intake and bone mineral density. In our loading test with a low-calcium, high-phosphorus lunch provided to healthy young men, serum PTH concentrations showed peaks at 1 and 6 h, and serum fibroblast growth factor 23 (FGF23) concentrations increased significantly at 8 h after the meal. In contrast, the high-calcium, high-phosphorus meal suppressed the second PTH and FGF23 elevations until 8 h after the meal. This implies that adequate dietary calcium intake is needed to overcome the interfering effects of high phosphorus intake on PTH and FGF23 secretion. FGF23 acts on the parathyroid gland to decrease PTH mRNA and PTH secretion in rats with normal kidney function. However, increased serum FGF23 is an early alteration of mineral metabolism in chronic kidney disease, causing secondary hyperthyroidism, and implying resistance of the parathyroid gland to the action of FGF23 in chronic kidney disease. These findings suggest that long-term high-phosphorus diets may impair bone health

  19. Increasing Dietary Phosphorus Intake from Food Additives: Potential for Negative Impact on Bone Health123

    Science.gov (United States)

    Takeda, Eiji; Yamamoto, Hironori; Yamanaka-Okumura, Hisami; Taketani, Yutaka

    2014-01-01

    It is important to consider whether habitual high phosphorus intake adversely affects bone health, because phosphorus intake has been increasing, whereas calcium intake has been decreasing in dietary patterns. A higher total habitual dietary phosphorus intake has been associated with higher serum parathyroid hormone (PTH) and lower serum calcium concentrations in healthy individuals. Higher serum PTH concentrations have been shown in those who consume foods with phosphorus additives. These findings suggest that long-term dietary phosphorus loads and long-term hyperphosphatemia may have important negative effects on bone health. In contrast, PTH concentrations did not increase as a result of high dietary phosphorus intake when phosphorus was provided with adequate amounts of calcium. Intake of foods with a ratio of calcium to phosphorus close to that found in dairy products led to positive effects on bone health. Several randomized controlled trials have shown positive relations between dairy intake and bone mineral density. In our loading test with a low-calcium, high-phosphorus lunch provided to healthy young men, serum PTH concentrations showed peaks at 1 and 6 h, and serum fibroblast growth factor 23 (FGF23) concentrations increased significantly at 8 h after the meal. In contrast, the high-calcium, high-phosphorus meal suppressed the second PTH and FGF23 elevations until 8 h after the meal. This implies that adequate dietary calcium intake is needed to overcome the interfering effects of high phosphorus intake on PTH and FGF23 secretion. FGF23 acts on the parathyroid gland to decrease PTH mRNA and PTH secretion in rats with normal kidney function. However, increased serum FGF23 is an early alteration of mineral metabolism in chronic kidney disease, causing secondary hyperthyroidism, and implying resistance of the parathyroid gland to the action of FGF23 in chronic kidney disease. These findings suggest that long-term high-phosphorus diets may impair bone health

  20. Development and evaluation of a HEPA filter for increased strength and resistance to elevated temperature

    International Nuclear Information System (INIS)

    Gilbert, H.; Bergman, W.; Fretthold, J.K.

    1992-01-01

    We have developed an improved HEPA filter for increased strength and resistance to elevated temperature to improve the reliability of HEPA filters under accident conditions. The improvements to the HEPA filter consist of a silicone rubber sealant and a new HEPA medium reinforced with a glass cloth. Several prototype filters were built and evaluated for temperature and pressure resistance and resistance to rough handling. The temperature resistance test consisted of exposing the HEPA filter to 1,000 scan at 700 degrees F for five minutes. The pressure resistance test consisted of exposing the HEPA filter to a differential pressure of 10 in. w.g. using a water saturated air flow at 95 degrees F. For the rough handling test, we used a vibrating machine designated the Q110. DOP filter efficiency tests were performed before and after each of the environmental tests. In addition to following the standard practice of using a separate new filter for each environmental test, we also subjected the same filter to the elevated temperature test followed by the pressure resistance test. The efficiency test results show that the improved HEPA filter is significantly better than the standard HEPA filter

  1. Development and evaluation of a HEPA filter for increased strength and resistance to elevated temperature

    International Nuclear Information System (INIS)

    Gilbert, H.; Bergman, W.; Fretthold, J.K.

    1993-01-01

    We have completed a preliminary study of an improved HEPA filter for increased strength and resistance to elevated temperature to improve the reliability of the standard deep pleated HEPA filter under accident conditions. The improvements to the HEPA filter consist of a silicone rubber sealant and a new HEPA medium reinforced with a glass cloth. Three prototype filters were built and evaluated for temperature and pressure resistance and resistance to rough handling. The temperature resistance test consisted of exposing the HEPA filter to 1,000 scan (1,700 m 3 /hr) at 700 degrees F (371 degrees C) for five minutes.The pressure resistance test consisted of exposing the HEPA filter to a differential pressure of 10 in. w.g. (2.5 kPa) using a water saturated air flow at 95 degrees F (35 degrees C). For the rough handling test, we used a vibrating machine designated the Q110. DOP filter efficiency tests were performed before and after each of the environmental tests. In addition to following the standard practice of using a separate new filter for each environmental test, we also subjected the same filter to the elevated temperature test followed by the pressure resistance test. The efficiency test results show that the improved HEPA filter is significantly better than the standard HEPA filter. Further studies are recommended to evaluate the improved HEPA filter and to assess its performance under more severe accident conditions

  2. CL316,243, a β3-adrenergic receptor agonist, induces muscle hypertrophy and increased strength.

    Science.gov (United States)

    Puzzo, Daniela; Raiteri, Roberto; Castaldo, Clotilde; Capasso, Raffaele; Pagano, Ester; Tedesco, Mariateresa; Gulisano, Walter; Drozd, Lisaveta; Lippiello, Pellegrino; Palmeri, Agostino; Scotto, Pietro; Miniaci, Maria Concetta

    2016-11-22

    Studies in vitro have demonstrated that β3-adrenergic receptors (β3-ARs) regulate protein metabolism in skeletal muscle by promoting protein synthesis and inhibiting protein degradation. In this study, we evaluated whether activation of β3-ARs by the selective agonist CL316,243 modifies the functional and structural properties of skeletal muscles of healthy mice. Daily injections of CL316,243 for 15 days resulted in a significant improvement in muscle force production, assessed by grip strength and weight tests, and an increased myofiber cross-sectional area, indicative of muscle hypertrophy. In addition, atomic force microscopy revealed a significant effect of CL316,243 on the transversal stiffness of isolated muscle fibers. Interestingly, the expression level of mammalian target of rapamycin (mTOR) downstream targets and neuronal nitric oxide synthase (NOS) was also found to be enhanced in tibialis anterior and soleus muscles of CL316,243 treated mice, in accordance with previous data linking β3-ARs to mTOR and NOS signaling pathways. In conclusion, our data suggest that CL316,243 systemic administration might be a novel therapeutic strategy worthy of further investigations in conditions of muscle wasting and weakness associated with aging and muscular diseases.

  3. On the increasing of adhesive strength of nanotube layers on beta titanium alloys for medical applications

    Energy Technology Data Exchange (ETDEWEB)

    Fojt, Jaroslav, E-mail: fojtj@vscht.cz; Filip, Vladimir; Joska, Ludek

    2015-11-15

    Graphical abstract: - Highlights: • The nanostructured surface on Ti–36Nb–6Ta alloy was prepared by anodic oxidation. • The nanotubes properties were modified by electrochemical process parameters. • The composition and mechanical properties of the anodized surface were investigated. • The adhesive strength of the nanostructures was over 30 MPa. - Abstract: The nanostructuring of titanium and its alloys surfaces is used inter alia for increasing the medical implants osseointegration. Many papers about this topic were published. However, in most cases there were no informations about nanostructures adhesion to the surface, which is crucial from the application point of view. The aim of this study was to prepare nanostructures on titanium beta alloy and optimized its adhesion to the alloy surface. Nanotubes were formed by anodic polarization in electrolyte containing fluoride ions. The composition of the nanotubes was described by X-ray photoelectron spectroscopy. Nanostructures adhesion was tested by pull-of method. The nanotubes on the Ti–36Nb–6Ta beta alloy surface were prepared by anodization. The nanostructures properties were modified by electrochemical process parameters. The adhesion of the nanotubes prepared in this work was satisfactory for implantological applications.

  4. Increasing break-down strength of the support colomn of high-voltage accelerators

    International Nuclear Information System (INIS)

    Rezvykh, K.A.; Romanov, V.A.

    1981-01-01

    Calculation results of strength of electric field of the EG-2.5 electrostatic accelerator for the support colomn with electrodes of circular and elliptical transverse cross sections are presented. Conducted is the choice of constructing the column under the condition that the dimensions of the tank, high-voltage electrode, step between the sections and internal diameter of the colomn electrodes are not changed. The potential at the high-voltage electrode equals 2.5 MV while the average longitudinal gradient of the colomn field equals 1.25 MV/m. The support insulation colomn of the high-voltage accelerator screened by rings with transverse cross section in the form of orientation oval in some accelerators promotes obtaining higher operating voltage and at the same time increase of operation reliability at the rest unchanged dimensions of the plant because the probability of break-down between the support colomn and the tank wall decreases. The latter is especially significant for most high-energy accelerators as well as for accelerators used in national economy [ru

  5. Osteoporosis in clinical practice – bone densitometry and fracture risk

    African Journals Online (AJOL)

    Osteoporosis is a condition of decreased bone mass and bone density associated with an increase in fracture risk. Bone mineral density (BMD) of the lumbar spine and femur can be reliably measured by double-beam X-ray absorptiometry (DEXA), which provides a measure of bone strength. Reduction in BMD is a ...

  6. Association study of common variants in the sFRP1 gene region and parameters of bone strength and body composition in two independent healthy Caucasian male cohorts

    DEFF Research Database (Denmark)

    Boudin, Eveline; Piters, Elke; Fransen, Erik

    2012-01-01

    has an influence on bone formation. Therefore this study aimed to investigate the effect of common genetic variation on BMD and bone strength in Caucasian men of different ages. Using HapMap we selected 13 tagSNPs which tag most common genetic variation in and around sFRP1 and we genotyped these SNPs...... parameters. Based on the results of the young cohort we selected three SNPs for further analysis in the complete OAS population. To conclude we tried to replicate the results of two SNPs in an independent population of 994 Belgian men. We found a strong association for rs9694405 with BMI as well in both...

  7. Adipocyte tissue volume in bone marrow is increased with aging and in patients with osteoporosis

    DEFF Research Database (Denmark)

    Justesen, J; Dokkedahl, Karin Stenderup; Ebbesen, E N

    2001-01-01

    Aging of the human skeleton is characterized by decreased bone formation and bone mass and these changes are more pronounced in patients with osteoporosis. As osteoblasts and adipocytes share a common precursor cell in the bone marrow, we hypothesized that decreased bone formation observed during...

  8. Towards Rocket Engine Components with Increased Strength and Robust Operating Characteristics

    Science.gov (United States)

    Marcu, Bogdan; Hadid, Ali; Lin, Pei; Balcazar, Daniel; Rai, Man Mohan; Dorney, Daniel J.

    2005-01-01

    High-energy rotating machines, powering liquid propellant rocket engines, are subject to various sources of high and low cycle fatigue generated by unsteady flow phenomena. Given the tremendous need for reliability in a sustainable space exploration program, a fundamental change in the design methodology for engine components is required for both launch and space based systems. A design optimization system based on neural-networks has been applied and demonstrated in the redesign of the Space Shuttle Main Engine (SSME) Low Pressure Oxidizer Turbo Pump (LPOTP) turbine nozzle. One objective of the redesign effort was to increase airfoil thickness and thus increase its strength while at the same time detuning the vane natural frequency modes from the vortex shedding frequency. The second objective was to reduce the vortex shedding amplitude. The third objective was to maintain this low shedding amplitude even in the presence of large manufacturing tolerances. All of these objectives were achieved without generating any detrimental effects on the downstream flow through the turbine, and without introducing any penalty in performance. The airfoil redesign and preliminary assessment was performed in the Exploration Technology Directorate at NASA ARC. Boeing/Rocketdyne and NASA MSFC independently performed final CFD assessments of the design. Four different CFD codes were used in this process. They include WIL DCA T/CORSAIR (NASA), FLUENT (commercial), TIDAL (Boeing Rocketdyne) and, a new family (AardvarWPhantom) of CFD analysis codes developed at NASA MSFC employing LOX fluid properties and a Generalized Equation Set formulation. Extensive aerodynamic performance analysis and stress analysis carried out at Boeing Rocketdyne and NASA MSFC indicate that the redesign objectives have been fully met. The paper presents the results of the assessment analysis and discusses the future potential of robust optimal design for rocket engine components.

  9. Bone Geometry, Volumetric Density, Microarchitecture and Estimated Bone Strength Assessed by HR-pQCT in Adult Patients with Hypophosphatemic Rickets

    DEFF Research Database (Denmark)

    Shanbhogue, Vikram Vinod; Hansen, Stinus; Folkestad, Lars

    2015-01-01

    Hypophosphatemic rickets (HR) is characterized by a generalized mineralization defect. Although densitometric studies have found the patients to have an elevated bone mineral density (BMD), data on bone geometry and microstructure are scarce. The aim of this cross-sectional in vivo study was to a......Hypophosphatemic rickets (HR) is characterized by a generalized mineralization defect. Although densitometric studies have found the patients to have an elevated bone mineral density (BMD), data on bone geometry and microstructure are scarce. The aim of this cross-sectional in vivo study...

  10. Effect of short-term upper-body resistance training on muscular strength, bone metabolic markers, and BMD in premenopausal women

    Directory of Open Access Journals (Sweden)

    Liang MT

    2012-11-01

    Full Text Available Michael TC Liang,1 Lorena Quezada,1 WY Jamie Lau,1 Bulent Sokmen,2 Thomas W Spalding11Department of Kinesiology and Health Promotion, California State Polytechnic University, Pomona, CA, USA; 2Department of Kinesiology, Sonoma State University, Rohnert Park, CA, USAAbstract: To examine the effect of a 10-week upper-body resistance training program on bone turnover markers and site-specific bone mineral density (BMD in the wrist and distal half of the ulna and radius in untrained and healthy young premenopausal women.Methods: Twenty-two subjects (aged 22.1 ± 1.8 years were randomly assigned to a resistance training (n = 12 or no training control (n = 10 group. The following outcome variables were measured before and after 10 weeks of resistance training: (1 bone formation biomarker osteocalcin, and bone resorption biomarker tartrate-resistant acid phosphatase isoform 5b; (2 BMD in the wrist and distal half of the ulna and radius; (3 isokinetic strength of the elbow and knee extensors and flexors; (4 dynamic strength of the arm extensors and flexors; and (5 maximum number of push-ups.Results: The 10-week upper body resistance training intervention resulted in improved strength performance in push-ups (resistance training versus control: P < 0.05, chest presses (P < 0.05, and pulldowns (P < 0.05. However, there was no improvement in the BMD of the wrist (P > 0.05, BMD of the distal half of the ulna and radius (P > 0.05, and metabolic biomarkers osteocalcin (P > 0.05 and tartrate-resistant acid phosphatase isoform 5b (P > 0.05, except for the osteocalcin/tartrate-resistant acid phosphatase isoform 5b ratio. Also, no improvement in the resistance training group was observed for isokinetic strength of the knee and elbow flexion/extension.Conclusion: Upper-body muscular strength performance, but not bone metabolic markers and BMD of the wrist, can be improved with a 10-week upper body resistance training program of the nonweight-bearing limbs in

  11. Rope skipping increases bone mineral density at calcanei of pubertal girls in Hong Kong: A quasi-experimental investigation.

    Directory of Open Access Journals (Sweden)

    Amy S Ha

    Full Text Available Bone mineral accrual during puberty is important, especially in girls, because it is related to reduced risks of osteoporosis in adulthood. Previous research has shown that jumping or plyometric exercises may be effective in increasing bone mineral density in adolescents. Rope skipping is a form of activity that involves jumping, thus regular skipping may also increase bone mineral density in pubertal girls. To this end, we conducted a quasi-experimental to examine the effects of rope skipping on girls' bone mineral density and cardiovascular fitness. 176 Hong Kong girls (age = 12.23 ± 1.80 years at baseline were recruited to take part in the study. Bone density at their forearms and calcanei were measured twice over two academic years (mean time between visits was 10.3 months. Using multilevel modeling analyses and adjusting for participants' height and physical activity, we found that girls who participated in weekly rope skipping activities, compared to those who did not, had higher levels of bone density at the calcanei (B = 0.023, p < .01. However, no differences were found for bone density at forearms or participants' cardiovascular fitness. The rates of change of these variables across time were also not significantly different. Results suggest that regular rope skipping may increase girls' bone density at the lower extremities, irrespective of the amount of self-report physical activity. However, further research is required to examine the potential dose-response relation between skipping behaviors and the measured outcomes.

  12. Assessment of the increased calcification of the jaw bone with CT-Scan after dental implant placement

    International Nuclear Information System (INIS)

    Yunus, Barunawaty

    2011-01-01

    This study was performed to evaluate the changes of jaw bone density around the dental implant after placement using computed tomography scan (CT-Scan). This retrospective study consisted of 30 patients who had lost 1 posterior tooth in maxilla or mandible and installed dental implant. The patients took CT-Scan before and after implant placement. Hounsfield Unit (HU) was measured around the implants and evaluated the difference of HU before and after implant installation. The mean HU of jaw bone was 542.436 HU and 764.9 HU before and after implant placement, respectively (p<0.05). The means HUs for male were 632.3 HU and 932.2 HU and those for female 478.2 HU and 645.5 HU before and after implant placement, respectively (p<0.05). Also, the jaw bone with lower density needed longer period for implant procedure and the increased change of HU of jaw bone was less in the cases which needed longer period for osseointegration. CT-Scan could be used to assess the change of bone density around dental implants. Bone density around dental implant was increased after placement. The increased rate of bone density could be determined by the quality of jaw bone before implant placement.

  13. Assessment of the increased calcification of the jaw bone with CT-Scan after dental implant placement.

    Science.gov (United States)

    Yunus, Barunawaty

    2011-06-01

    This study was performed to evaluate the changes of jaw bone density around the dental implant after placement using computed tomography scan (CT-Scan). This retrospective study consisted of 30 patients who had lost 1 posterior tooth in maxilla or mandible and installed dental implant. The patients took CT-Scan before and after implant placement. Hounsfield Unit (HU) was measured around the implants and evaluated the difference of HU before and after implant installation. The mean HU of jaw bone was 542.436 HU and 764.9 HU before and after implant placement, respectively (p<0.05). The means HUs for male were 632.3 HU and 932.2 HU and those for female 478.2 HU and 645.5 HU before and after implant placement, respectively (p<0.05). Also, the jaw bone with lower density needed longer period for implant procedure and the increased change of HU of jaw bone was less in the cases which needed longer period for osseointegration. CT-Scan could be used to assess the change of bone density around dental implants. Bone density around dental implant was increased after placement. The increased rate of bone density could be determined by the quality of jaw bone before implant placement.

  14. Assessment of the increased calcification of the jaw bone with CT-Scan after dental implant placement

    Energy Technology Data Exchange (ETDEWEB)

    Yunus, Barunawaty [Faculty of Dentistry, Hasanuddin University, Makassar (Malaysia)

    2011-06-15

    This study was performed to evaluate the changes of jaw bone density around the dental implant after placement using computed tomography scan (CT-Scan). This retrospective study consisted of 30 patients who had lost 1 posterior tooth in maxilla or mandible and installed dental implant. The patients took CT-Scan before and after implant placement. Hounsfield Unit (HU) was measured around the implants and evaluated the difference of HU before and after implant installation. The mean HU of jaw bone was 542.436 HU and 764.9 HU before and after implant placement, respectively (p<0.05). The means HUs for male were 632.3 HU and 932.2 HU and those for female 478.2 HU and 645.5 HU before and after implant placement, respectively (p<0.05). Also, the jaw bone with lower density needed longer period for implant procedure and the increased change of HU of jaw bone was less in the cases which needed longer period for osseointegration. CT-Scan could be used to assess the change of bone density around dental implants. Bone density around dental implant was increased after placement. The increased rate of bone density could be determined by the quality of jaw bone before implant placement.

  15. Progressive resistance training increases strength after stroke but this may not carry over to activity: a systematic review.

    Science.gov (United States)

    Dorsch, Simone; Ada, Louise; Alloggia, Daniella

    2018-04-01

    Does progressive resistance training improve strength and activity after stroke? Does any increase in strength carry over to activity? Systematic review of randomised trials with meta-analysis. Adults who have had a stroke. Progressive resistance training compared with no intervention or placebo. The primary outcome was change in strength. This measurement had to be of maximum voluntary force production and performed in muscles congruent with the muscles trained in the intervention. The secondary outcome was change in activity. This measurement had to be a direct measure of performance that produced continuous or ordinal data, or with scales that produced ordinal data. Eleven studies involving 370 participants were included in this systematic review. The overall effect of progressive resistance training on strength was examined by pooling change scores from six studies with a mean PEDro score of 5.8, representing medium quality. The effect size of progressive resistance training on strength was 0.98 (95% CI 0.67 to 1.29, I 2 =0%). The overall effect of progressive resistance training on activity was examined by pooling change scores from the same six studies. The effect size of progressive resistance training on activity was 0.42 (95% CI -0.08 to 0.91, I 2 =54%). After stroke, progressive resistance training has a large effect on strength compared with no intervention or placebo. There is uncertainty about whether these large increases in strength carry over to improvements in activity. PROSPERO CRD42015025401. [Dorsch S, Ada L, Alloggia D (2018) Progressive resistance training increases strength after stroke but this may not carry over to activity: a systematic review. Journal of Physiotherapy 64: 84-90]. Copyright © 2018 Australian Physiotherapy Association. Published by Elsevier B.V. All rights reserved.

  16. 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

    with or without administration of the GLP-1 RA liraglutide (1.2mg/day) for 52 weeks. In case of weight gain, up to two meals per day could be substituted with a low-calorie diet product in order to maintain the weight loss. MAIN OUTCOME MEASURES: Total, pelvic and arm-leg bone mineral content (BMC) and bone...... 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...... in the control group (ptotal and arm-leg BMC loss was 4 times greater in the control group compared to the liraglutide group (estimated difference 27g (95% CI 5-48), p=0.01), although the 12% weight loss was maintained in both groups...

  17. Muscle strength, power and cardiorespiratory fitness are associated with bone mineral density in men aged 31-60 years

    DEFF Research Database (Denmark)

    Schwarz, Peter; Jørgensen, Niklas; Nielsen, Barbara

    2014-01-01

    BACKGROUND: Osteoporotic fractures represent a growing economical burden to society, not only because of fractures in women, but also because of an increasing number of fractures in men. AIMS: In this cross-sectional study we aimed to investigate the association of muscular and cardio-respiratory......BACKGROUND: Osteoporotic fractures represent a growing economical burden to society, not only because of fractures in women, but also because of an increasing number of fractures in men. AIMS: In this cross-sectional study we aimed to investigate the association of muscular and cardio......-respiratory fitness with BMD at the spine and hip in men. RESULTS: The association between independent variables maximal aerobic capacity (VO(2max)), leg power and hand grip strength, and dependent variables BMD at the spine and total hip was explored in a series of linear regression models successively adjusted.......011) with BMD at total hip. CONCLUSIONS: We found that cardiorespiratory fitness was associated with BMD in men. Furthermore, hand grip strength and leg power were associated with increasing BMD at the lumbar spine and total hip in men, respectively. Further prospective studies are needed to further investigate...

  18. Interleukin-17A increases leptin production in human bone marrow mesenchymal stem cells.

    Science.gov (United States)

    Noh, Minsoo

    2012-03-01

    Lineage commitment of human bone marrow mesenchymal stem cells (hBM-MSCs) to adipocytes or osteoblasts has been suggested as a model system to study the relationship between type II diabetes and abnormal bone metabolism. Leptin and IL-17A inhibit adipogenesis whereas they promote osteogenesis in MSCs. Due to pathophysiologic roles of IL-17A in human metabolic diseases and bone metabolism, it was evaluated whether IL-17A-dependent inverse regulation on adipogenesis and osteogenesis was related to endogenous leptin production in hBM-MSCs. In the analysis of adiponectin and leptin secretion profiles of hBM-MSCs in response to various combinations of differentiation inducing factors, it was found that dexamethasone, a common molecule used for both adipogenesis and osteogenesis, increased leptin production in hBM-MSCs. Importantly, the level of leptin production during osteogenesis in hBM-MSCs was higher than that during adipogenesis, implicating a significant leptin production in extra-adipose tissues. IL-17A increased leptin production in hBM-MSCs and also under the condition of osteogenesis. In spite of direct inhibition on adipogenesis, IL-17A up-regulated leptin production in hBM-MSC-derived adipocytes. Anti-leptin antibody treatment partially antagonized the IL-17A dependent inhibition of adipogenesis in hBM-MSCs, suggesting a role of leptin in mediating the inverse regulation of IL-17A on osteogenesis and adipogenesis in hBM-MSCs. Therefore, the IL-17A-induced leptin production may provide a key clue to understand a molecular mechanism on the lineage commitment of hBM-MSCs into adipocytes or osteoblasts. In addition, leptin production in extra-adipose tissues like MSCs and osteoblasts should be considered in future studies on leptin-associated human diseases. Copyright © 2011 Elsevier Inc. All rights reserved.

  19. Combined Treatment of Alendronate and Low-Intensity Pulsed Ultrasound (LIPUS Increases Bone Mineral Density at the Cancellous Bone Osteotomy Site in Aged Rats: A Preliminary Study.

    Directory of Open Access Journals (Sweden)

    H Aonuma

    2011-12-01

    Full Text Available Introduction: During fracture healing, alendronate encourages callus volume by inhibiting bone resorption, whereas low-intensity pulsed ultrasound (LIPUS enhances bone regeneration by promoting an anabolic response. Methods: In the present study, 9-month-old Sprague-Dawley rats, with a unilateral proximal tibial osteotomy, were treated with alendronate (daily, 1 g/kg plus sham-LIPUS (n = 14, saline plus LIPUS (20 min/day (n = 18, alendronate plus LIPUS (n = 16, or saline plus sham- LIPUS as a control (n = 13 for 4 weeks. The rats were then examined for changes in bone mineral density (BMD during metaphyseal bone repair. Results: The combined therapy signi cantly increased BMD at the osteotomy site at 4 weeks (p < 0.001 compared with the control, without affecting the contralateral, non-osteotomized tibia. Both alendronate and LIPUS alone also exerted a positive, albeit less, effect on BMD in the affected limb (p < 0.001 and p = 0.006, respectively. Conclusions: Alendronate and LIPUS cooperate to enhance BMD during metaphyseal bone healing. Keywords: LIPUS, bisphosphonate, bone mineral density.

  20. Urbanization of black South African women may increase risk of low bone mass due to low vitamin D status, low calcium intake, and high bone turnover.

    Science.gov (United States)

    Kruger, Marlena C; Kruger, Iolanthé M; Wentzel-Viljoen, Edelweiss; Kruger, Annamarie

    2011-10-01

    Globally, rural to urban migration is accompanied by changes in dietary patterns and lifestyle that have serious health implications, including development of low bone mass. We hypothesized that serum 25 (OH) vitamin D3 (25[OH]D3) levels will be lower, bone turnover higher, and nutrition inadequate in urban postmenopausal black women, increasing risk for low bone mass. We aimed to assess the prevalence of risk factors for low bone mass in 1261 black women from rural and urban areas in the North West Province of South Africa (Prospective Urban and Rural Epidemiology-South Africa project). Fasting blood samples were taken; and participants were interviewed to complete questionnaires on self-reported diseases, fractures, and dietary intakes. Bone health markers were assessed in a subgroup of 658 women older than 45 years. Specific lifestyle risk factors identified were inactivity, smoking, injectable progestin contraception use, and high alcohol consumption. Dietary risk factors identified were low calcium and high animal protein, phosphorous, and sodium intakes. The 25(OH)D3 and C-terminal telopeptide (CTX) levels were significantly higher in the rural vs the urban women older than 50 years. Parathyroid hormone (PTH) levels increased with age in both groups. The 25(OH)D levels were inversely correlated with CTX and PTH in rural women. In urban women, PTH and CTX were correlated while dietary calcium was inversely correlated with CTX and PTH with 25(OH)D3. The combination of low dietary calcium (<230 mg/d), marginally insufficient 25(OH)D3 status, and raised PTH may result in increased bone resorption. Further research is required to assess bone health and fracture risk in black African women. Copyright © 2011 Elsevier Inc. All rights reserved.

  1. Large eccentric strength increase using the Copenhagen Adduction exercise in football

    DEFF Research Database (Denmark)

    Ishøi, L; Sørensen, C N; Kaae, N M

    2016-01-01

    (control). EHAD, eccentric hip abduction strength (EHAB), and side-bridge endurance were measured using reliable test procedures at baseline and follow-up by a blinded tester. There was a significant interaction between group and time on EHAD, EHAB, and EHAD/EHAB ratio (P 

  2. Bone marrow mesenchymal stem cells overexpressing human basic fibroblast growth factor increase vasculogenesis in ischemic rats

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, J.C. [Department of Vascular Surgery, The First Affiliated Hospital of Fujian Medical University, Fuzhou (China); Zheng, G.F. [Department of Vascular Surgery, The People' s Hospital of Ganzhou, Ganzhou (China); Wu, L.; Ou Yang, L.Y.; Li, W.X. [Department of Vascular Surgery, The First Affiliated Hospital of Fujian Medical University, Fuzhou (China)

    2014-08-08

    Administration or expression of growth factors, as well as implantation of autologous bone marrow cells, promote in vivo angiogenesis. This study investigated the angiogenic potential of combining both approaches through the allogenic transplantation of bone marrow-derived mesenchymal stem cells (MSCs) expressing human basic fibroblast growth factor (hbFGF). After establishing a hind limb ischemia model in Sprague Dawley rats, the animals were randomly divided into four treatment groups: MSCs expressing green fluorescent protein (GFP-MSC), MSCs expressing hbFGF (hbFGF-MSC), MSC controls, and phosphate-buffered saline (PBS) controls. After 2 weeks, MSC survival and differentiation, hbFGF and vascular endothelial growth factor (VEGF) expression, and microvessel density of ischemic muscles were determined. Stable hbFGF expression was observed in the hbFGF-MSC group after 2 weeks. More hbFGF-MSCs than GFP-MSCs survived and differentiated into vascular endothelial cells (P<0.001); however, their differentiation rates were similar. Moreover, allogenic transplantation of hbFGF-MSCs increased VEGF expression (P=0.008) and microvessel density (P<0.001). Transplantation of hbFGF-expressing MSCs promoted angiogenesis in an in vivo hind limb ischemia model by increasing the survival of transplanted cells that subsequently differentiated into vascular endothelial cells. This study showed the therapeutic potential of combining cell-based therapy with gene therapy to treat ischemic disease.

  3. Bone marrow mesenchymal stem cells overexpressing human basic fibroblast growth factor increase vasculogenesis in ischemic rats

    Directory of Open Access Journals (Sweden)

    J.C. Zhang

    2014-10-01

    Full Text Available Administration or expression of growth factors, as well as implantation of autologous bone marrow cells, promote in vivo angiogenesis. This study investigated the angiogenic potential of combining both approaches through the allogenic transplantation of bone marrow-derived mesenchymal stem cells (MSCs expressing human basic fibroblast growth factor (hbFGF. After establishing a hind limb ischemia model in Sprague Dawley rats, the animals were randomly divided into four treatment groups: MSCs expressing green fluorescent protein (GFP-MSC, MSCs expressing hbFGF (hbFGF-MSC, MSC controls, and phosphate-buffered saline (PBS controls. After 2 weeks, MSC survival and differentiation, hbFGF and vascular endothelial growth factor (VEGF expression, and microvessel density of ischemic muscles were determined. Stable hbFGF expression was observed in the hbFGF-MSC group after 2 weeks. More hbFGF-MSCs than GFP-MSCs survived and differentiated into vascular endothelial cells (P<0.001; however, their differentiation rates were similar. Moreover, allogenic transplantation of hbFGF-MSCs increased VEGF expression (P=0.008 and microvessel density (P<0.001. Transplantation of hbFGF-expressing MSCs promoted angiogenesis in an in vivo hind limb ischemia model by increasing the survival of transplanted cells that subsequently differentiated into vascular endothelial cells. This study showed the therapeutic potential of combining cell-based therapy with gene therapy to treat ischemic disease.

  4. Increased autophagy in ephrinB2 deficient osteocytes is associated with hypermineralized, brittle bones

    OpenAIRE

    Crimeen-Irwin, Blessing; Sims, Natalie; Martin, T; Oakhill, Jonathan; Smyth, Gordon; Tobin, Mark; Petibois, Cyril; Bambery, Keith; Ikegame, Mika; Hu, Yifang; Forwood, Mark; Nguyen, Huynh; Ansari, Niloufar; Dite, Toby; Vrahnas, Christina

    2018-01-01

    Mineralized bone forms when collagen-containing osteoid accrues hydroxyapatite crystals. This process has two phases: a rapid initiation (primary mineralization), followed by slower accrual of mineral (secondary mineralization) that continues until that portion of bone is renewed by remodelling. Within the bone matrix is an interconnected network of cells termed osteocytes. These cells are derived from bone-forming osteoblasts. Osteoblast differentiation requires expression of ephrinB2, and w...

  5. Porous surface modified bioactive bone cement for enhanced bone bonding.

    Directory of Open Access Journals (Sweden)

    Qiang He

    Full Text Available Polymethylmethacrylate bone cement cannot provide an adhesive chemical bonding to form a stable cement-bone interface. Bioactive bone cements show bone bonding ability, but their clinical application is limited because bone resorption is observed after implantation. Porous polymethylmethacrylate can be achieved with the addition of carboxymethylcellulose, alginate and gelatin microparticles to promote bone ingrowth, but the mechanical properties are too low to be used in orthopedic applications. Bone ingrowth into cement could decrease the possibility of bone resorption and promote the formation of a stable interface. However, scarce literature is reported on bioactive bone cements that allow bone ingrowth. In this paper, we reported a porous surface modified bioactive bone cement with desired mechanical properties, which could allow for bone ingrowth.The porous surface modified bioactive bone cement was evaluated to determine its handling characteristics, mechanical properties and behavior in a simulated body fluid. The in vitro cellular responses of the samples were also investigated in terms of cell attachment, proliferation, and osteoblastic differentiation. Furthermore, bone ingrowth was examined in a rabbit femoral condyle defect model by using micro-CT imaging and histological analysis. The strength of the implant-bone interface was also investigated by push-out tests.The modified bone cement with a low content of bioactive fillers resulted in proper handling characteristics and adequate mechanical properties, but slightly affected its bioactivity. Moreover, the degree of attachment, proliferation and osteogenic differentiation of preosteoblast cells was also increased. The results of the push-out test revealed that higher interfacial bonding strength was achieved with the modified bone cement because of the formation of the apatite layer and the osseointegration after implantation in the bony defect.Our findings suggested a new bioactive

  6. The Influence of Reconstruction Kernel on Bone Mineral and Strength Estimates Using Quantitative Computed Tomography and Finite Element Analysis.

    Science.gov (United States)

    Michalski, Andrew S; Edwards, W Brent; Boyd, Steven K

    2017-10-17

    Quantitative computed tomography has been posed as an alternative imaging modality to investigate osteoporosis. We examined the influence of computed tomography convolution back-projection reconstruction kernels on the analysis of bone quantity and estimated mechanical properties in the proximal femur. Eighteen computed tomography scans of the proximal femur were reconstructed using both a standard smoothing reconstruction kernel and a bone-sharpening reconstruction kernel. Following phantom-based density calibration, we calculated typical bone quantity outcomes of integral volumetric bone mineral density, bone volume, and bone mineral content. Additionally, we performed finite element analysis in a standard sideways fall on the hip loading configuration. Significant differences for all outcome measures, except integral bone volume, were observed between the 2 reconstruction kernels. Volumetric bone mineral density measured using images reconstructed by the standard kernel was significantly lower (6.7%, p kernel. Furthermore, the whole-bone stiffness and the failure load measured in images reconstructed by the standard kernel were significantly lower (16.5%, p kernel. These data suggest that for future quantitative computed tomography studies, a standardized reconstruction kernel will maximize reproducibility, independent of the use of a quantitative calibration phantom. Copyright © 2017 The International Society for Clinical Densitometry. Published by Elsevier Inc. All rights reserved.

  7. Immobilization and long-term recovery results in large changes in bone structure and strength but no corresponding alterations of osteocyte lacunar properties.

    Science.gov (United States)

    Bach-Gansmo, Fiona Linnea; Wittig, Nina Kølln; Brüel, Annemarie; Thomsen, Jesper Skovhus; Birkedal, Henrik

    2016-10-01

    The ability of osteocytes to demineralize the perilacunar matrix, osteocytic osteolysis, and thereby participate directly in bone metabolism, is an aspect of osteocyte biology that has received increasing attention during the last couple of years. The aim of the present work was to investigate whether osteocyte lacunar properties change during immobilization and subsequent recovery. A rat cortical bone model with negligible Haversian remodeling effects was used, with temporary immobilization of one hindlimb induced by botulinum toxin. Several complementary techniques covering multiple length scales enabled correlation of osteocyte lacunar properties to changes observed on the organ and tissue level of femoral bone. Bone structural parameters measured by μCT and mechanical properties were compared to sub-micrometer resolution SR μCT data mapping an unprecedented number (1.85 million) of osteocyte lacunae. Immobilization induced a significant reduction in aBMD, bone volume, tissue volume, and load to fracture, as well as the muscle mass of rectus femoris. During the subsequent recovery period, the bone structural and mechanical properties were only partly regained in spite of a long-term (28weeks) study period. No significant changes in osteocyte lacunar volume, density, oblateness, stretch, or orientation were detected upon immobilization or subsequent recovery. In conclusion, the bone architecture and not osteocyte lacunar properties or bone material characteristics dominate the immobilization response as well as the subsequent recovery. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. A novel chitosan-tussah silk fibroin/nano-hydroxyapatite composite bone scaffold platform with tunable mechanical strength in a wide range.

    Science.gov (United States)

    Ran, Jiabing; Hu, Jingxiao; Sun, Guanglin; Chen, Si; Jiang, Pei; Shen, Xinyu; Tong, Hua

    2016-12-01

    Currently, great efforts have been made to enhance the mechanical strength of bone tissue engineering (BTE) scaffolds, which are composed of biopolymeric matrices and inorganic nano-fillers. But the tunability of mechanical strength in a wide range for BTE scaffolds has seldom been investigated in spite of the great importance of this performance. In this work, a chitosan-tussah silk fibroin/hydroxyapatite (CS-TSF/HAp) hydrogel was synthesized by using a novel in situ precipitation method. Through in situ inducing the conformation transition of TSF in the CS-TSF/HAp hydrogel, which could be monitored by XRD, FT-IR, TGA, and DTA, the elastic modulus and fracture strength of the final CS-TSF/HAp composite could be tailored in a wide range without changing its composition, morphology, roughness, and crystal structures. The elastic modulus of the CS-TSF/HAp composite ranged from ∼250 to ∼400MPa while its fracture strength ranged from ∼45 to ∼100MPa. In order to clarify the rationale behind this process, a speculative explanation was provided. In vitro cell culture indicated that MC3T3-E1 cells cultured on the CS-TSF/HAp composite had positive adhesion, proliferation, and differentiation potential. We believed that the CS-TSF/HAp composite could be used as an ideal scaffold platform for cell culture and implantation of bone reconstruction. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. The bioimpedance phase angle predicts low muscle strength, impaired quality of life, and increased mortality in old patients with cancer.

    Science.gov (United States)

    Norman, Kristina; Wirth, Rainer; Neubauer, Maxi; Eckardt, Rahel; Stobäus, Nicole

    2015-02-01

    We investigated the impact of low phase angle (PhA) values on muscle strength, quality of life, symptom severity, and 1-year mortality in older cancer patients. Prospective study with 1-year follow-up. Cancer patients aged >60 years. PhA was derived from whole body impedance analysis. The fifth percentile of age-, sex-, and body mass index-stratified reference values were used as cut-off. Quality of life was determined with the European Organization of Research and Treatment in Cancer questionnaire, reflecting both several function scales and symptom severity. Muscle strength was assessed by hand grip strength, knee extension strength, and peak expiratory flow. 433 cancer patients, aged 60-95 years, were recruited. Patients with low PhA (n = 197) exhibited decreased muscle strength compared with patients with normal PhA (hand grip strength: 22 ± 8.6 vs 28.9 ± 8.9 kg, knee extension strength: 20.8 ± 11.8 vs 28.1 ± 14.9 kg, and peak expiratory flow: 301.1 ± 118 vs 401.7 ± 142.6 L/min, P Cancer questionnaire were reduced, and most symptoms (fatigue, anorexia, pain, and dyspnea) increased in patients with low PhA (P quality of life, and increased mortality in old patients with cancer and should be evaluated in routine assessment. Copyright © 2015 AMDA – The Society for Post-Acute and Long-Term Care Medicine. Published by Elsevier Inc. All rights reserved.

  10. Effectiveness of various isometric exercises at improving bone strength in cortical regions prone to distal tibial stress fractures.

    Science.gov (United States)

    Florio, C S

    2018-06-01

    A computational model was used to compare the local bone strengthening effectiveness of various isometric exercises that may reduce the likelihood of distal tibial stress fractures. The developed model predicts local endosteal and periosteal cortical accretion and resorption based on relative local and global measures of the tibial stress state and its surface variation. Using a multisegment 3-dimensional leg model, tibia shape adaptations due to 33 combinations of hip, knee, and ankle joint angles and the direction of a single or sequential series of generated isometric resultant forces were predicted. The maximum stress at a common fracture-prone region in each optimized geometry was compared under likely stress fracture-inducing midstance jogging conditions. No direct correlations were found between stress reductions over an initially uniform circular hollow cylindrical geometry under these critical design conditions and the exercise-based sets of active muscles, joint angles, or individual muscle force and local stress magnitudes. Additionally, typically favorable increases in cross-sectional geometric measures did not guarantee stress decreases at these locations. Instead, tibial stress distributions under the exercise conditions best predicted strengthening ability. Exercises producing larger anterior distal stresses created optimized tibia shapes that better resisted the high midstance jogging bending stresses. Bent leg configurations generating anteriorly directed or inferiorly directed resultant forces created favorable adaptations. None of the studied loads produced by a straight leg was significantly advantageous. These predictions and the insight gained can provide preliminary guidance in the screening and development of targeted bone strengthening techniques for those susceptible to distal tibial stress fractures. Copyright © 2018 John Wiley & Sons, Ltd.

  11. Increasing the compressive strength of portland cement concrete using flat glass powder

    Energy Technology Data Exchange (ETDEWEB)

    Miranda Junior, Edson Jansen Pedrosa de; Bezerra, Helton de Jesus Costa Leite; Politi, Flavio Salgado; Paiva, Antonio Ernandes Macedo, E-mail: edson.jansen@ifma.edu.br [Instituto Federal de Educacao, Ciencia e Tecnologia do Maranha (IFMA), Sao Luis, MA (Brazil). Dept. de Mecanica e Materiais

    2014-08-15

    This paper analyzes the compressive strength of Portland cement concrete in response to the incorporation of 5%, 10% and 20% of flat glass powder in place of sand, at w/c (water/cement) ratios of 0.50, 0.55 and 0.58. A statistical analysis of variance (ANOVA) was performed after 7, 14 and 28 days of curing. The compressive strength test results indicate that the concrete containing a w/c ratio of 0.50 can be used for structural applications, regardless of the waste glass content, as can that with a w/c ratio of 0.55 containing 20% of waste glass. We suggest that the use of flat glass powder in place of sand in the above mentioned percentages is feasible for the production of an environmentally appropriate and structurally applicable concrete. However, the concrete's fluidity and void content must be taken into account. (author)

  12. Increased skeletal muscle 11βHSD1 mRNA is associated with lower muscle strength in ageing.

    Directory of Open Access Journals (Sweden)

    Alixe H M Kilgour

    Full Text Available Sarcopenia, the loss of muscle mass and function with age, is associated with increased morbidity and mortality. Current understanding of the underlying mechanisms is limited. Glucocorticoids (GC in excess cause muscle weakness and atrophy. We hypothesized that GC may contribute to sarcopenia through elevated circulating levels or increased glucocorticoid receptor (GR signaling by increased expression of either GR or the GC-amplifying enzyme 11 beta-hydroxysteroid dehydrogenase type 1 (11βHSD1 in muscle.There were 82 participants; group 1 comprised 33 older men (mean age 70.2 years, SD 4.4 and 19 younger men (22.2 years, 1.7 and group 2 comprised 16 older men (79.1 years, 3.4 and 14 older women (80.1 years, 3.7. We measured muscle strength, mid-thigh cross-sectional area, fasting morning plasma cortisol, quadriceps muscle GR and 11βHSD1 mRNA, and urinary glucocorticoid metabolites. Data were analysed using multiple linear regression adjusting for age, gender and body size.Muscle strength and size were not associated with plasma cortisol, total urinary glucocorticoids or the ratio of urinary 5β-tetrahydrocortisol +5α-tetrahydrocortisol to tetrahydrocortisone (an index of systemic 11βHSD activity. Muscle strength was associated with 11βHSD1 mRNA levels (β -0.35, p = 0.04, but GR mRNA levels were not significantly associated with muscle strength or size.Although circulating levels of GC are not associated with muscle strength or size in either gender, increased cortisol generation within muscle by 11βHSD1 may contribute to loss of muscle strength with age, a key component of sarcopenia. Inhibition of 11βHSD1 may have therapeutic potential in sarcopenia.

  13. Investigating strengths and deficits to increase work engagement: A longitudinal study in the mining industry

    Directory of Open Access Journals (Sweden)

    Pule Mphahlele

    2018-02-01

    Full Text Available Orientation: The motivational process of the Job Demands-Resources (JD-R model indicates that job resources are the main predictors of work engagement. Previous research has found that the two job resources perceived organisational support (POS for strengths use and POS for deficit correction are also positively related to work engagement. However, the causal relationships between these variables have not been investigated longitudinally. Research purpose: To determine if POS for strengths use and POS for deficit correction are significant predictors of work engagement over time. Motivation for the study: In the literature, empirical evidence on the longitudinal relationships between work engagement and specific job resources, namely POS for strengths use and POS for deficit correction, is limited. Research design, approach and method: A longitudinal design was employed in this study. The first wave elicited a total of 376 responses, while the second wave had a total sample size of 79. A web-based survey was used to measure the constructs and to gather data at both points in time. Structural equation modelling was used to investigate the hypotheses. Main findings: The results indicated that both POS for strengths use and POS for deficit correction are positively related to work engagement in the short term. However, only POS for deficit correction significantly predicted work engagement over time. Practical and managerial implications: The results provide valuable insights to organisations by providing knowledge regarding which approach influences work engagement levels of their employees in the short and long term. Contribution or value-add: The study contributes to the limited research on what job resources predict work engagement over time.

  14. Increase of reliability of contact networks of electric transport, due to increase of strength of the joint unit of pipes of different diameters

    Science.gov (United States)

    Sabitov, L. S.; Kashapov, N. F.; Gilmanshin, I. R.; Gatiyatov, I. Z.; Kuznetsov, I. L.

    2017-09-01

    The feature of the stress state of the supports of the contact networks is the presence of a joint of pipes of different diameters, the ultimate state of which is determined, as a rule, the strength of the weld. The proposed unit allows to increase the reliability and strength of the connection and also exclude the presence of a weld bead on the outer surface of the pipe of smaller diameter in the place of its attachment to the upper end of the support ring.

  15. Increasing the Strength of Adhesively Bonded Joints by Tapering the Adherends

    International Nuclear Information System (INIS)

    GUESS, TOMMY R.; METZINGER, KURT E.

    1999-01-01

    Wind turbine blades are often fabricated with composite materials. These composite blades are frequently attached to a metallic structure with an adhesive bond. For the baseline composite-to-steel joint considered in this study, failure typically occurs when the adhesive debonds from the steel adherend. Previous efforts established that the adhesive peel stresses strongly influence the strength of these joints for both single-cycle and fatigue loading. This study focused on reducing the adhesive peel stresses present in these joints by tapering the steel adherends. Several different tapers were evaluated using finite element analysis before arriving at a final design. To confirm that the selected taper was an improvement to the existing design, the baseline joint and the modified joint were tested in both compression and tension. In these axial tests, the compressive strengths of the joints with tapered adherends were greater than those of the baseline joints for both single-cycle and low-cycle fatigue. In addition, only a minor reduction in tensile strength was observed for the joints with tapered adherends when compared to the baseline joints. Thus, the modification would be expected to enhance the overall performance of this joint

  16. Genetic ablation of CD68 results in mice with increased bone and dysfunctional osteoclasts.

    Directory of Open Access Journals (Sweden)

    Jason W Ashley

    Full Text Available CD68 is a member of the lysosome associated membrane protein (LAMP family that is restricted in its expression to cells of the monocyte/macrophage lineage. This lineage restriction includes osteoclasts, and, while previous studies of CD68 in macrophages and dendritic cells have proposed roles in lipid metabolism, phagocytosis, and antigen presentation, the expression and function of CD68 in osteoclasts have not been explored. In this study, we investigated the expression and localization of CD68 in macrophages and osteoclasts in response to the monocyte/macrophage-colony stimulating factor (M-CSF and the receptor activator of NF-κB ligand (RANKL. We found that M-CSF stimulates CD68 expression and RANKL alters the apparent molecular weight of CD68 as measured by Western immunoblotting. In addition, we explored the significance of CD68 expression in osteoclasts by generating mice that lack expression of CD68. These mice have increased trabecular bone, and in vitro assessment of CD68(-/- osteoclasts revealed that, in the absence of CD68, osteoclasts demonstrate an accumulation of intracellular vesicle-like structures, and do not efficiently resorb bone. These findings demonstrate a role for CD68 in the function of osteoclasts, and future studies will determine the mechanistic nature of the defects seen in CD68(-/- osteoclasts.

  17. Increased variability of bone tissue mineral density resulting from estrogen deficiency influences creep behavior in a rat vertebral body.

    Science.gov (United States)

    Kim, Do-Gyoon; Navalgund, Anand R; Tee, Boon Ching; Noble, Garrett J; Hart, Richard T; Lee, Hye Ri

    2012-11-01

    Progressive vertebral deformation increases the fracture risk of a vertebral body in the postmenopausal patient. Many studies have observed that bone can demonstrate creep behavior, defined as continued time-dependent deformation even when mechanical loading is held constant. Creep is a characteristic of viscoelastic behavior, which is common in biological materials. We hypothesized that estrogen deficiency-dependent alteration of the mineral distribution of bone at the tissue level could influence the progressive postmenopausal vertebral deformity that is observed as the creep response at the organ level. The objective of this study was thus to examine whether the creep behavior of vertebral bone is changed by estrogen deficiency, and to determine which bone property parameters are responsible for the creep response of vertebral bone at physiological loading levels using an ovariectomized (OVX) rat model. Correlations of creep parameters with bone mineral density (BMD), tissue mineral density (TMD) and architectural parameters of both OVX and sham surgery vertebral bone were tested. As the vertebral creep was not fully recovered during the post-creep unloading period, there was substantial residual displacement for both the sham and OVX groups. A strong positive correlation between loading creep and residual displacement was found (r=0.868, pcreep behavior of the OVX group (pcreep caused progressive, permanent reduction in vertebral height for both the sham and OVX groups. In addition, estrogen deficiency-induced active bone remodeling increased variability of trabecular TMD in the OVX group. Taken together, these results suggest that increased variability of trabecular TMD resulting from high bone turnover influences creep behavior of the OVX vertebrae. Copyright © 2012 Elsevier Inc. All rights reserved.

  18. Bone suppression increases the visibility of invasive pulmonary aspergillosis in chest radiographs.

    Directory of Open Access Journals (Sweden)

    Steven Schalekamp

    Full Text Available Chest radiographs (CXR are an important diagnostic tool for the detection of invasive pulmonary aspergillosis (IPA in critically ill patients, but their diagnostic value is limited by a poor sensitivity. By using advanced image processing, the aim of this study was to increase the value of chest radiographs in the diagnostic work up of neutropenic patients who are suspected of IPA.The frontal CXRs of 105 suspected cases of IPA were collected from four institutions. Radiographs could contain single or multiple sites of infection. CT was used as reference standard. Five radiologists and two residents participated in an observer study for the detection of IPA on CXRs with and without bone suppressed images (ClearRead BSI 3.2; Riverain Technologies. The evaluation was performed separately for the right and left lung, resulting in 78 diseased cases (or lungs and 132 normal cases (or lungs. For each image, observers scored the likelihood of focal infectious lesions being present on a continuous scale (0-100. The area under the receiver operating characteristics curve (AUC served as the performance measure. Sensitivity and specificity were calculated by considering only the lungs with a suspiciousness score of greater than 50 to be positive.The average AUC for only CXRs was 0.815. Performance significantly increased, to 0.853, when evaluation was aided with BSI (p = 0.01. Sensitivity increased from 49% to 66% with BSI, while specificity decreased from 95% to 90%.The detection of IPA in CXRs can be improved when their evaluation is aided by bone suppressed images. BSI improved the sensitivity of the CXR examination, outweighing a small loss in specificity.

  19. Increased bone marrow blood flow in sickle cell anemia demonstrated by thallium-201 and Tc-99m human albumin microspheres

    International Nuclear Information System (INIS)

    Thrall, J.H.; Rucknagel, D.L.

    1978-01-01

    Lower extremity vascularity in nine patients with sickle cell anemia was studied by intra-arterial /sup 99m/Tc human albumin microspheres or intravenous thallium-201. In eight patients, the normal pattern of greater muscle than bone activity was reversed with marked tracer localization in skeletal parts usually not visualized. In four cases, there were distinct focal abnormalities in the femurs and tibias which correlated with defects on /sup 99m/Tc sulfur colloid marrow scans. TC-99m pyrophosphate bone scans demonstrated normal uptake in the same areas. The scintigraphic findings indicate a markedly increased relative bone marrow blood flow

  20. Targeted Disruption of NF1 in Osteocytes Increases FGF23 and Osteoid With Osteomalacia-like Bone Phenotype.

    Science.gov (United States)

    Kamiya, Nobuhiro; Yamaguchi, Ryosuke; Aruwajoye, Olumide; Kim, Audrey J; Kuroyanagi, Gen; Phipps, Matthew; Adapala, Naga Suresh; Feng, Jian Q; Kim, Harry Kw

    2017-08-01

    Neurofibromatosis type 1 (NF1, OMIM 162200), caused by NF1 gene mutations, exhibits multi-system abnormalities, including skeletal deformities in humans. Osteocytes play critical roles in controlling bone modeling and remodeling. However, the role of neurofibromin, the protein product of the NF1 gene, in osteocytes is largely unknown. This study investigated the role of neurofibromin in osteocytes by disrupting Nf1 under the Dmp1-promoter. The conditional knockout (Nf1 cKO) mice displayed serum profile of a metabolic bone disorder with an osteomalacia-like bone phenotype. Serum FGF23 levels were 4 times increased in cKO mice compared with age-matched controls. In addition, calcium-phosphorus metabolism was significantly altered (calcium reduced; phosphorus reduced; parathyroid hormone [PTH] increased; 1,25(OH) 2 D decreased). Bone histomorphometry showed dramatically increased osteoid parameters, including osteoid volume, surface, and thickness. Dynamic bone histomorphometry revealed reduced bone formation rate and mineral apposition rate in the cKO mice. TRAP staining showed a reduced osteoclast number. Micro-CT demonstrated thinner and porous cortical bones in the cKO mice, in which osteocyte dendrites were disorganized as assessed by electron microscopy. Interestingly, the cKO mice exhibited spontaneous fractures in long bones, as found in NF1 patients. Mechanical testing of femora revealed significantly reduced maximum force and stiffness. Immunohistochemistry showed significantly increased FGF23 protein in the cKO bones. Moreover, primary osteocytes from cKO femora showed about eightfold increase in FGF23 mRNA levels compared with control cells. The upregulation of FGF23 was specifically and significantly inhibited by PI3K inhibitor Ly294002, indicating upregulation of FGF23 through PI3K in Nf1-deficient osteocytes. Taken together, these results indicate that Nf1 deficiency in osteocytes dramatically increases FGF23 production and causes a mineralization

  1. Telomerase-Deficient Mice Exhibit Bone Loss Owing to Defects in Osteoblasts and Increased Osteoclastogenesis by Inflammatory Microenvironment

    DEFF Research Database (Denmark)

    Saeed, H.; Abdallah, B. M.; Ditzel, N.

    2011-01-01

    Telomere shortening owing to telomerase deficiency leads to accelerated senescence of human skeletal (mesenchymal) stem cells (MSCs) in vitro, whereas overexpression leads to telomere elongation, extended life span, and enhanced bone formation. To study the role of telomere shortening in vivo, we...... studied the phenotype of telomerase-deficient mice (Terc(-/-)).Terc(-/-) mice exhibited accelerated age-related bone loss starting at 3 months of age and during 12 months of follow-up revealed by dual-energy X-ray absorptiometric (DXA) scanning and by micro-computed tomography (mu CT). Bone...... histomorphometry revealed decreased mineralized surface and bone-formation rate as well as increased osteoclast number and size in Terc(-/-) mice. Also, serum total deoxypyridinoline (tDPD) was increased in Terc(-/-) mice. MSCs and osteoprogenitors isolated from Terc(-l-) mice exhibited intrinsic defects...

  2. Differential response of risedronate on tibial and mandibular bone quality in glucocorticoid-treated growing rats

    International Nuclear Information System (INIS)

    Fujita, Yuko

    2008-01-01

    Glucocorticoids induce bone loss and retard bone growth in children. In this study we investigated the effect of treatment with risedronate on glucocorticoid -prednisolone-induced decreases in bone density, quality, strength and growth of the tibia and mandible in growing rats. Trabecular and cortical bone structure was measured by peripheral quantitative computed tomography (pQCT) and three-dimensional (3D) micro-computed tomography (micro-CT). Indicators of bone strength were calculated from cortical bone density and the modulus of sections obtained from pQCT analysis. Tibial and mandibular bone sizes were also measured. Prednisolone decreased the bone growth of both tibia and mandible. It also caused deterioration of trabecular and cortical bone structure and strength in the mandible, and in cortical bone in the tibia, but had no effect on trabecular bone in the tibia. Risedronate inhibited the prednisolone-induced decreases in tibial width and mandibular length and height but did not improve the retardation of longitudinal bone growth. Risedronate prevented prednisolone-induced deterioration of trabecular and cortical bone architecture. In the mandible, this protective effect of risedronate was accompanied by an increase in cortical bone density and in bone strength. These findings show that risedronate inhibits prednisolone-induced loss of bone density, structure, decrease in bone strength, and retardation of bone growth in the mandible in young growing rats. (author)

  3. Increases in muscle strength and balance using a resistance training program administered via a telecommunications system in older adults.

    Science.gov (United States)

    Sparrow, David; Gottlieb, Daniel J; Demolles, Deborah; Fielding, Roger A

    2011-11-01

    Resistance training programs have been found to improve muscle strength, physical function, and depressive symptoms in middle-aged and older adults. These programs have typically been provided in clinical facilities, health clubs, and senior centers, which may be inconvenient and/or cost prohibitive for some older adults. The purpose of this study was to investigate the effectiveness of an automated telemedicine intervention that provides real-time guidance and monitoring of resistance training in the home. A randomized clinical trial in 103 middle-aged or older participants. Participants were assigned to use of a theory-driven interactive voice response system designed to promote resistance training (Telephone-Linked Computer-based Long-term Interactive Fitness Trainer; n = 52) or to an attention control (n = 51) for a period of 12 months. Measurements of muscle strength, balance, walk distance, and mood were obtained at baseline, 3, 6, and 12 months. We observed increased strength, improved balance, and fewer depressive symptoms in the intervention group than in the control group. Using generalized estimating equations modeling, group differences were statistically significant for knee flexion strength (p = .035), single-leg stance time (p = .029), and Beck Depression Inventory (p = .030). This computer-based telecommunications exercise intervention led to improvements in participants' strength, balance, and depressive symptoms. Because of their low cost and easy accessibility, computer-based interventions may be a cost-effective way of promoting exercise in the home.

  4. Increased bone morphogenetic protein signaling contributes to age-related declines in neurogenesis and cognition.

    Science.gov (United States)

    Meyers, Emily A; Gobeske, Kevin T; Bond, Allison M; Jarrett, Jennifer C; Peng, Chian-Yu; Kessler, John A

    2016-02-01

    Aging is associated with decreased neurogenesis in the hippocampus and diminished hippocampus-dependent cognitive functions. Expression of bone morphogenetic protein 4 (BMP4) increases with age by more than 10-fold in the mouse dentate gyrus while levels of the BMP inhibitor, noggin, decrease. This results in a profound 30-fold increase in phosphorylated-SMAD1/5/8, the effector of canonical BMP signaling. Just as observed in mice, a profound increase in expression of BMP4 is observed in the dentate gyrus of humans with no known cognitive abnormalities. Inhibition of BMP signaling either by overexpression of noggin or transgenic manipulation not only increases neurogenesis in aging mice, but remarkably, is associated with a rescue of cognitive deficits to levels comparable to young mice. Additive benefits are observed when combining inhibition of BMP signaling and environmental enrichment. These findings indicate that increased BMP signaling contributes significantly to impairments in neurogenesis and to cognitive decline associated with aging, and identify this pathway as a potential druggable target for reversing age-related changes in cognition. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. Alzheimer's Disease Increases the Incidence of Hospitalization Due to Fall-related Bone Fracture in Elderly Chinese

    Directory of Open Access Journals (Sweden)

    Fang Li

    2016-12-01

    Conclusion: On the basis of our findings, we conclude that AD may increase the incidence of hospitalization due to falls and bone fracture. We also found that AD has no effect on fracture location, but larger studies are needed to confirm this finding. Physicians and family members should emphasize the possibility of falls and bone fracture in patients with AD. Our findings suggest that preventing falls in AD patients may reduce the number of hospitalized AD patients.

  6. Prevalence of radiographic hip osteoarthritis is increased in high bone mass.

    Science.gov (United States)

    Hardcastle, S A; Dieppe, P; Gregson, C L; Hunter, D; Thomas, G E R; Arden, N K; Spector, T D; Hart, D J; Laugharne, M J; Clague, G A; Edwards, M H; Dennison, E M; Cooper, C; Williams, M; Davey Smith, G; Tobias, J H

    2014-08-01

    Epidemiological studies have shown an association between increased bone mineral density (BMD) and osteoarthritis (OA), but whether this represents cause or effect remains unclear. In this study, we used a novel approach to investigate this question, determining whether individuals with High Bone Mass (HBM) have a higher prevalence of radiographic hip OA compared with controls. HBM cases came from the UK-based HBM study: HBM was defined by BMD Z-score. Unaffected relatives of index cases were recruited as family controls. Age-stratified random sampling was used to select further population controls from the Chingford and Hertfordshire cohort studies. Pelvic radiographs were pooled and assessed by a single observer blinded to case-control status. Analyses used logistic regression, adjusted for age, gender and body mass index (BMI). 530 HBM hips in 272 cases (mean age 62.9 years, 74% female) and 1702 control hips in 863 controls (mean age 64.8 years, 84% female) were analysed. The prevalence of radiographic OA, defined as Croft score ≥3, was higher in cases compared with controls (20.0% vs 13.6%), with adjusted odds ratio (OR) [95% CI] 1.52 [1.09, 2.11], P = 0.013. Osteophytes (OR 2.12 [1.61, 2.79], P subchondral sclerosis (OR 2.78 [1.49, 5.18], P = 0.001) were more prevalent in cases. However, no difference in the prevalence of joint space narrowing (JSN) was seen (OR 0.97 [0.72, 1.33], P = 0.869). An increased prevalence of radiographic hip OA and osteophytosis was observed in HBM cases compared with controls, in keeping with a positive association between HBM and OA and suggesting that OA in HBM has a hypertrophic phenotype. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  7. Bone mineral density, muscle strength and physical activity. A population-based study of 332 subjects aged 15-42 years.

    Science.gov (United States)

    Düppe, H; Gärdsell, P; Johnell, O; Nilsson, B E; Ringsberg, K

    1997-04-01

    The aim of this population-based study was to find out whether differences in levels of physical activity have an influence on bone mass quantity and whether quadriceps muscle strength is a reliable determinant of bone mass. Included were 175 men and 157 women, aged 15-42 years. Bone mineral density (BMD) was measured at various sites by dual X-ray absorptiometry (DXA) and single photon absorptiometry (SPA). Muscle strength was assessed using an isokinetic muscle force meter. A questionnaire was used to estimate the level of physical activity. We found a positive correlation between physical activity and BMD for boys at the distal forearm and for girls at the trochanter (age group 15-16 years). Active men (age group 21-42 years) had up to 9% higher BMD levels at the hip than those who were less active. Quadriceps muscle torque was not an independent predictor of BMD. Our data suggest that a higher level of physical activity-within the limits of a "normal life style"-may have a positive effect on BMD in the proximal femur of young adults, which in turn may lessen the subsequent risk of fracture.

  8. Transforming growth factor-beta1 adsorbed to tricalciumphosphate coated implants increases peri-implant bone remodeling

    DEFF Research Database (Denmark)

    Lin, M.; Overgaard, S; Glerup, H

    2001-01-01

    inserted bilaterally into the femoral condyles of 10 skeletally mature mongrel dogs. The implants were initially surrounded by a 2 mm gap. Implants with 0.3 microg rhTGF-beta1 were compared with implants without growth factor. The dogs were sacrificed after six weeks. Bone remodeling was evaluated...... by histomorphometry on Goldner-stained undecalcified sections. The bone volume in the gap was increased significantly from 17.6% in the control group to 25.6% in the rhTGF-beta1 group (p = 0.03). Also bone surface was increased in the rhTGF-beta1 group. The osteoclast covered surfaces were increased from 3.......6% in the control group to 5.9% in the rhTGF-beta1 group (p = 0.02). In the surrounding trabecular bone no significant changes in bone remodeling parameters was demonstrated. This study suggests that rhTGF-beta1 adsorbed onto TCP-ceramic coated implants accelerates repair activity in the newly formed bone close...

  9. 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.

  10. Can repetitive transcranial magnetic stimulation increase muscle strength in functional neurological paresis? A proof-of-principle study.

    Science.gov (United States)

    Broersma, M; Koops, E A; Vroomen, P C; Van der Hoeven, J H; Aleman, A; Leenders, K L; Maurits, N M; van Beilen, M

    2015-05-01

    Therapeutic options are limited in functional neurological paresis disorder. Earlier intervention studies did not control for a placebo effect, hampering assessment of effectivity. A proof-of-principle investigation was conducted into the therapeutic potential of repetitive transcranial magnetic stimulation (rTMS), using a single-blind two-period placebo-controlled cross-over design. Eleven patients received active 15 Hz rTMS over the contralateral motor cortex (hand area), in two periods of 5 days, for 30 min once a day at 80% of resting motor threshold, with a train length of 2 s and an intertrain interval of 4 s. Eight of these eleven patients were also included in the placebo treatment condition. Primary outcome measure was change in muscle strength as measured by dynamometry after treatment. Secondary outcome measure was the subjective change in muscle strength after treatment. In patients who received both treatments, active rTMS induced a significantly larger median increase in objectively measured muscle strength (24%) compared to placebo rTMS (6%; P difference due to treatment, i.e. patients did not perceive these objectively measured motor improvements (P = 0.40). Our findings suggest that rTMS by itself can potentially improve muscle weakness in functional neurological paresis disorder. Whereas patients' muscle strength increased as measured with dynamometry, patients did not report increased functioning of the affected hand, subjectively. The results may indicate that decreased muscle strength is not the core symptom and that rTMS should be added to behavioral approaches in functional neurological paresis. © 2015 EAN.

  11. Tensile strength decreases and perfusion pressure of 3-holed polyamide epidural catheters increases in long-term epidural infusion.

    Science.gov (United States)

    Kim, Pascal; Meyer, Urs; Schüpfer, Guido; Rukwied, Roman; Konrad, Christoph; Gerber, Helmut

    2011-01-01

    Epidural analgesia is an established method for pain management. The failure rate is 8% to 12% due to technical difficulties (catheter dislocation and/or disconnection; partial or total catheter occlusion) and management. The mechanical properties of the catheters, like tensile strength and flow rate, may also be affected by the analgesic solution and/or the tissue environment. We investigated the tensile strength and perfusion pressure of new (n=20), perioperatively (n=30), and postoperatively (n=73) used epidural catheters (20-gauge, polyamide, closed tip, 3 side holes; Perifix [B. Braun]). To prevent dislocation, epidural catheters were taped (n=5) or fixed by suture (n=68) to the skin. After removal, mechanical properties were assessed by a tensile-testing machine (INSTRON 4500), and perfusion pressure was measured at flow rates of 10, 20, and 40 mL/h. All catheters demonstrated a 2-step force transmission. Initially, a minimal increase of length could be observed at 15 N followed by an elongation of several cm at additional forces (7 N). Breakage occurred in the control group at 23.5±1.5 N compared with 22.4±1.6 N in perioperative and 22.4±1.7 N in postoperative catheters (Ptensile strength, whereas perfusion pressure at clinically used flow rates (10 mL/h) increased significantly from 19±1.3 to 44±72 mm Hg during long-term (≥7 days) epidural analgesia (Ptensile strength or perfusion pressure. Epidural catheter use significantly increases the perfusion pressure and decreases the tensile strength. Copyright © 2011 by American Society of Regional Anesthesia and Pain Medicine

  12. Increasing the strength and bioactivity of collagen scaffolds using customizable arrays of 3D-printed polymer fibers.

    Science.gov (United States)

    Mozdzen, Laura C; Rodgers, Ryan; Banks, Jessica M; Bailey, Ryan C; Harley, Brendan A C

    2016-03-01

    Tendon is a highly aligned connective tissue which transmits force from muscle to bone. Each year, people in the US sustain more than 32 million tendon injuries. To mitigate poor functional outcomes due to scar formation, current surgical techniques rely heavily on autografts. Biomaterial platforms and tissue engineering methods offer an alternative approach to address these injuries. Scaffolds incorporating aligned structural features can promote expansion of adult tenocytes and mesenchymal stem cells capable of tenogenic differentiation. However, appropriate balance between scaffold bioactivity and mechanical strength of these constructs remains challenging. The high porosity required to facilitate cell infiltration, nutrient and oxygen biotransport within three-dimensional constructs typically results in insufficient biomechanical strength. Here we describe the use of three-dimensional printing techniques to create customizable arrays of acrylonitrile butadiene styrene (ABS) fibers that can be incorporated into a collagen scaffold under development for tendon repair. Notably, mechanical performance of scaffold-fiber composites (elastic modulus, peak stress, strain at peak stress, and toughness) can be selectively manipulated by varying fiber-reinforcement geometry without affecting the native bioactivity of the collagen scaffold. Further, we report an approach to functionalize ABS fibers with activity-inducing growth factors via sequential oxygen plasma and carbodiimide crosslinking treatments. Together, we report an adaptable approach to control both mechanical strength and presence of biomolecular cues in a manner orthogonal to the architecture of the collagen scaffold itself. Tendon injuries account for more than 32 million injuries each year in the US alone. Current techniques use allografts to mitigate poor functional outcomes, but are not ideal platforms to induce functional regeneration following injury. Tissue engineering approaches using biomaterial

  13. Caffeine-induced increase in voluntary activation and strength of the quadriceps muscle during isometric, concentric and eccentric contractions.

    Science.gov (United States)

    Behrens, Martin; Mau-Moeller, Anett; Weippert, Matthias; Fuhrmann, Josefin; Wegner, Katharina; Skripitz, Ralf; Bader, Rainer; Bruhn, Sven

    2015-05-13

    This study investigated effects of caffeine ingestion (8 mg/kg) on maximum voluntary torque (MVT) and voluntary activation of the quadriceps during isometric, concentric and eccentric contractions. Fourteen subjects ingested caffeine and placebo in a randomized, controlled, counterbalanced, double-blind crossover design. Neuromuscular tests were performed before and 1 h after oral caffeine and placebo intake. MVTs were measured and the interpolated twitch technique was applied during isometric, concentric and eccentric contractions to assess voluntary activation. Furthermore, normalized root mean square of the EMG signal was calculated and evoked spinal reflex responses (H-reflex evoked at rest and during weak isometric voluntary contraction) as well as twitch torques were analyzed. Caffeine increased MVT by 26.4 N m (95%CI: 9.3-43.5 N m, P = 0.004), 22.5 N m (95%CI: 3.1-42.0 N m, P = 0.025) and 22.5 N m (95%CI: 2.2-42.7 N m, P = 0.032) for isometric, concentric and eccentric contractions. Strength enhancements were associated with increases in voluntary activation. Explosive voluntary strength and voluntary activation at the onset of contraction were significantly increased following caffeine ingestion. Changes in spinal reflex responses and at the muscle level were not observed. Data suggest that caffeine ingestion induced an acute increase in voluntary activation that was responsible for the increased strength regardless of the contraction mode.

  14. Comparative Analysis of Bone Structural Parameters Reveals Subchondral Cortical Plate Resorption and Increased Trabecular Bone Remodeling in Human Facet Joint Osteoarthritis

    Directory of Open Access Journals (Sweden)

    Cordula Netzer

    2018-03-01

    Full Text Available Facet joint osteoarthritis is a prominent feature of degenerative spine disorders, highly prevalent in ageing populations, and considered a major cause for chronic lower back pain. Since there is no targeted pharmacological therapy, clinical management of disease includes analgesic or surgical treatment. The specific cellular, molecular, and structural changes underpinning facet joint osteoarthritis remain largely elusive. The aim of this study was to determine osteoarthritis-related structural alterations in cortical and trabecular subchondral bone compartments. To this end, we conducted comparative micro computed tomography analysis in healthy (n = 15 and osteoarthritic (n = 22 lumbar facet joints. In osteoarthritic joints, subchondral cortical plate thickness and porosity were significantly reduced. The trabecular compartment displayed a 42 percent increase in bone volume fraction due to an increase in trabecular number, but not trabecular thickness. Bone structural alterations were associated with radiological osteoarthritis severity, mildly age-dependent but not gender-dependent. There was a lack of association between structural parameters of cortical and trabecular compartments in healthy and osteoarthritic specimens. The specific structural alterations suggest elevated subchondral bone resorption and turnover as a potential treatment target in facet joint osteoarthritis.

  15. Prediction of bone strength by μCT and MDCT-based finite-element-models: How much spatial resolution is needed?

    Energy Technology Data Exchange (ETDEWEB)

    Bauer, Jan S., E-mail: jsb@tum.de [Department of Radiology, Technische Universität München, Munich (Germany); Department of Radiology, University of California, San Francisco, CA (United States); Max Planck Institute for Extraterrestrial Physics, Garching (Germany); Sidorenko, Irina [Max Planck Institute for Extraterrestrial Physics, Garching (Germany); Mueller, Dirk [Department of Radiology, Universität Köln (Germany); Baum, Thomas [Department of Radiology, Technische Universität München, Munich (Germany); Department of Radiology, University of California, San Francisco, CA (United States); Max Planck Institute for Extraterrestrial Physics, Garching (Germany); Issever, Ahi Sema [Department of Radiology, University of California, San Francisco, CA (United States); Department of Radiology, Charite, Berlin (Germany); Eckstein, Felix [Institute of Anatomy and Musculoskeletal Research, Paracelsus Medical University, Salzburg (Austria); Rummeny, Ernst J. [Department of Radiology, Technische Universität München, Munich (Germany); Link, Thomas M. [Department of Radiology, University of California, San Francisco, CA (United States); Raeth, Christoph W. [Max Planck Institute for Extraterrestrial Physics, Garching (Germany)

    2014-01-15

    Objectives: Finite-element-models (FEM) are a promising technology to predict bone strength and fracture risk. Usually, the highest spatial resolution technically available is used, but this requires excessive computation time and memory in numerical simulations of large volumes. Thus, FEM were compared at decreasing resolutions with respect to local strain distribution and prediction of failure load to (1) validate MDCT-based FEM and to (2) optimize spatial resolution to save computation time. Materials and methods: 20 cylindrical trabecular bone specimens (diameter 12 mm, length 15–20 mm) were harvested from elderly formalin-fixed human thoracic spines. All specimens were examined by micro-CT (isotropic resolution 30 μm) and whole-body multi-row-detector computed tomography (MDCT, 250 μm × 250 μm × 500 μm). The resolution of all datasets was lowered in eight steps to ∼2000 μm × 2000 μm × 500 μm and FEM were calculated at all resolutions. Failure load was determined by biomechanical testing. Probability density functions of local micro-strains were compared in all datasets and correlations between FEM-based and biomechanically measured failure loads were determined. Results: The distribution of local micro-strains was similar for micro-CT and MDCT at comparable resolutions and showed a shift toward higher average values with decreasing resolution, corresponding to the increasing apparent trabecular thickness. Small micro-strains (ε{sub eff} < 0.005) could be calculated down to 250 μm × 250 μm × 500 μm. Biomechanically determined failure load showed significant correlations with all FEM, up to r = 0.85 and did not significantly change with lower resolution but decreased with high thresholds, due to loss of trabecular connectivity. Conclusion: When choosing connectivity-preserving thresholds, both micro-CT- and MDCT-based finite-element-models well predicted failure load and still accurately revealed the distribution of local micro-strains in

  16. Prediction of bone strength by μCT and MDCT-based finite-element-models: How much spatial resolution is needed?

    International Nuclear Information System (INIS)

    Bauer, Jan S.; Sidorenko, Irina; Mueller, Dirk; Baum, Thomas; Issever, Ahi Sema; Eckstein, Felix; Rummeny, Ernst J.; Link, Thomas M.; Raeth, Christoph W.

    2014-01-01

    Objectives: Finite-element-models (FEM) are a promising technology to predict bone strength and fracture risk. Usually, the highest spatial resolution technically available is used, but this requires excessive computation time and memory in numerical simulations of large volumes. Thus, FEM were compared at decreasing resolutions with respect to local strain distribution and prediction of failure load to (1) validate MDCT-based FEM and to (2) optimize spatial resolution to save computation time. Materials and methods: 20 cylindrical trabecular bone specimens (diameter 12 mm, length 15–20 mm) were harvested from elderly formalin-fixed human thoracic spines. All specimens were examined by micro-CT (isotropic resolution 30 μm) and whole-body multi-row-detector computed tomography (MDCT, 250 μm × 250 μm × 500 μm). The resolution of all datasets was lowered in eight steps to ∼2000 μm × 2000 μm × 500 μm and FEM were calculated at all resolutions. Failure load was determined by biomechanical testing. Probability density functions of local micro-strains were compared in all datasets and correlations between FEM-based and biomechanically measured failure loads were determined. Results: The distribution of local micro-strains was similar for micro-CT and MDCT at comparable resolutions and showed a shift toward higher average values with decreasing resolution, corresponding to the increasing apparent trabecular thickness. Small micro-strains (ε eff < 0.005) could be calculated down to 250 μm × 250 μm × 500 μm. Biomechanically determined failure load showed significant correlations with all FEM, up to r = 0.85 and did not significantly change with lower resolution but decreased with high thresholds, due to loss of trabecular connectivity. Conclusion: When choosing connectivity-preserving thresholds, both micro-CT- and MDCT-based finite-element-models well predicted failure load and still accurately revealed the distribution of local micro-strains in spatial

  17. Histone deacetylase 3 depletion in osteo/chondroprogenitor cells decreases bone density and increases marrow fat.

    Directory of Open Access Journals (Sweden)

    David F Razidlo

    2010-07-01

    Full Text Available Histone deacetylase (Hdac3 is a nuclear enzyme that contributes to epigenetic programming and is required for embryonic development. To determine the role of Hdac3 in bone formation, we crossed mice harboring loxP sites around exon 7 of Hdac3 with mice expressing Cre recombinase under the control of the osterix promoter. The resulting Hdac3 conditional knockout (CKO mice were runted and had severe deficits in intramembranous and endochondral bone formation. Calvarial bones were significantly thinner and trabecular bone volume in the distal femur was decreased 75% in the Hdac3 CKO mice due to a substantial reduction in trabecular number. Hdac3-CKO mice had fewer osteoblasts and more bone marrow adipocytes as a proportion of tissue area than their wildtype or heterozygous littermates. Bone formation rates were depressed in both the cortical and trabecular regions of Hdac3 CKO femurs. Microarray analyses revealed that numerous developmental signaling pathways were affected by Hdac3-deficiency. Thus, Hdac3 depletion in osterix-expressing progenitor cells interferes with bone formation and promotes bone marrow adipocyte differentiation. These results demonstrate that Hdac3 inhibition is detrimental to skeletal health.

  18. Effects of drop sets with resistance training on increases in muscle CSA, strength, and endurance: a pilot study.

    Science.gov (United States)

    Ozaki, Hayao; Kubota, Atsushi; Natsume, Toshiharu; Loenneke, Jeremy P; Abe, Takashi; Machida, Shuichi; Naito, Hisashi

    2018-03-01

    To investigate the effects of a single high-load (80% of one repetition maximum [1RM]) set with additional drop sets descending to a low-load (30% 1RM) without recovery intervals on muscle strength, endurance, and size in untrained young men. Nine untrained young men performed dumbbell curls to concentric failure 2-3 days per week for 8 weeks. Each arm was randomly assigned to one of the following three conditions: 3 sets of high-load (HL, 80% 1RM) resistance exercise, 3 sets of low-load [LL, 30% 1RM] resistance exercise, and a single high-load (SDS) set with additional drop sets descending to a low-load. The mean training time per session, including recovery intervals, was lowest in the SDS condition. Elbow flexor muscle cross-sectional area (CSA) increased similarly in all three conditions. Maximum isometric and 1RM strength of the elbow flexors increased from pre to post only in the HL and SDS conditions. Muscular endurance measured by maximum repetitions at 30% 1RM increased only in the LL and SDS conditions. A SDS resistance training program can simultaneously increase muscle CSA, strength, and endurance in untrained young men, even with lower training time compared to typical resistance exercise protocols using only high- or low-loads.

  19. 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...

  20. Association of Increased Serum Ferritin With Impaired Muscle Strength/Quality in Hemodialysis Patients.

    Science.gov (United States)

    Nakagawa, Chie; Inaba, Masaaki; Ishimura, Eiji; Yamakawa, Tomoyuki; Shoji, Shigeichi; Okuno, Senji

    2016-07-01

    We reported previously that muscle quality and muscle strength provide clinically relevant predictors for better survival in hemodialysis patients. Iron overload might impair muscle function by its accumulation in muscle in such patients. Serum ferritin, a marker for body iron store, was examined for its association with handgrip strength (HGS) and muscle quality which was defined as the ratio of HGS to arm lean mass measured with dual-energy X-ray absorptiometry. In 300 Japanese hemodialysis patients, age, hemodialysis duration, body mass index, and serum albumin were 58.0 ±12.0 (mean ± standard deviation) years, 4.2 (1.8-10.4) (median [25th-75th percentile]) years, 20.4 ± 2.8 kg/m(2), 4.0 ± 0.3 g/dL, respectively. Hemoglobin and hematocrit were 8.9 ± 1.2 g/dL, and 28.8 ± 3.9%, respectively, whereas transferrin saturation and serum ferritin were 29.8 ± 11.0% and 100 (54-172) ng/mL, respectively. Serum ferritin significantly correlated in a positive manner with the total dose of iron orally administered during the previous 6 months (r = 0.185, P = .0013). HGS and muscle quality were 23.1 ± 10.4 kg and 11.6 ± 3.8 kg/kg, respectively. In multivariate analysis to elucidate the factors associated with HGS and muscle quality in 300 hemodialysis patients, which included transferrin saturation and log serum ferritin, in addition to age, gender, hemodialysis duration, the presence/absence of diabetes, body mass index as independent variables, log serum ferritin emerged as a significant and independent factor which associated in a negative fashion with HGS (β = -0.091, P = .0395) and tendency toward negative association with muscle quality (β = -0.100, P = .0754). In summary, the present study demonstrated the significant association of serum ferritin with HGS and muscle quality in hemodialysis patients and thus suggested that we should be careful of iron overload to avoid its possible harmful effect on muscle in such patients. Copyright © 2016 National Kidney

  1. Increased Intake of Selected Vegetables, Herbs and Fruit may Reduce Bone Turnover in Post-Menopausal Women

    Directory of Open Access Journals (Sweden)

    Caroline Ann Gunn

    2015-04-01

    Full Text Available Increased consumption of vegetables/herbs/fruit may reduce bone turnover and urinary calcium loss in post-menopausal women because of increased intake of polyphenols and potassium, but comparative human studies are lacking. The main aim was to compare bone turnover markers and urinary calcium excretion in two randomised groups (n = 50 of healthy post-menopausal women consuming ≥9 servings of different vegetables/herbs/fruit combinations (three months. Group A emphasised a generic range of vegetables/herbs/fruit, whereas Group B emphasised specific vegetables/herbs/fruit with bone resorption-inhibiting properties (Scarborough Fair Diet, with both diets controlled for potential renal acid load (PRAL. Group C consumed their usual diet. Plasma bone markers, urinary electrolytes (24 h and estimated dietary PRAL were assessed at baseline and 12 weeks. Procollagen type I N propeptide (PINP decreased (−3.2 μg/L, p < 0.01 in the B group only, as did C-terminal telopeptide of type I collagen (CTX (−0.065 μg/L, p < 0.01 in women with osteopenia compared to those with normal bone mineral density (BMD within this group. Intervention Groups A and B had decreased PRAL, increased urine pH and significantly decreased urinary calcium loss. Urinary potassium increased in all groups, reflecting a dietary change. In conclusion, Group B demonstrated positive changes in both turnover markers and calcium conservation.

  2. Balance disorder and increased risk of falls in osteoporosis and kyphosis: significance of kyphotic posture and muscle strength.

    Science.gov (United States)

    Sinaki, Mehrsheed; Brey, Robert H; Hughes, Christine A; Larson, Dirk R; Kaufman, Kenton R

    2005-08-01

    This controlled trial was designed to investigate the influence of osteoporosis-related kyphosis (O-K) on falls. Twelve community-dwelling women with O-K (Cobb angle, 50-65 degrees measured from spine radiographs) and 13 healthy women serving as controls were enrolled. Mean age of the O-K group was 76 years (+/-5.1), height 158 cm (+/-5), and weight 61 kg (+/-7.9), and mean age of the control group was 71 years (+/-4.6), height 161 cm (+/-3.8), and weight 66 kg (+/-11.7). Quantitative isometric strength data were collected. Gait was monitored during unobstructed level walking and during stepping over an obstacle of four different heights randomly assigned (2.5%, 5%, 10%, and 15% of the subject's height). Balance was objectively assessed with computerized dynamic posturography consisting of the sensory organization test. Back extensor strength, grip strength, and all lower extremity muscle groups were significantly weaker in the O-K group than the control group (P controls for all conditions of unobstructed and obstructed level walking. Obstacle height had a significant effect on all center-of-mass variables. The O-K subjects had significantly greater balance abnormalities on computerized dynamic posturography than the control group (P =0.002). Data show that thoracic hyperkyphosis on a background of reduced muscle strength plays an important role in increasing body sway, gait unsteadiness, and risk of falls in osteoporosis.

  3. Increases in lower-body strength transfer positively to sprint performance: a systematic review with meta-analysis.

    Science.gov (United States)

    Seitz, Laurent B; Reyes, Alvaro; Tran, Tai T; Saez de Villarreal, Eduardo; Haff, G Gregory

    2014-12-01

    Although lower-body strength is correlated with sprint performance, whether increases in lower-body strength transfer positively to sprint performance remain unclear. This meta-analysis determined whether increases in lower-body strength (measured with the free-weight back squat exercise) transfer positively to sprint performance, and identified the effects of various subject characteristics and resistance-training variables on the magnitude of sprint improvement. A computerized search was conducted in ADONIS, ERIC, SPORTDiscus, EBSCOhost, Google Scholar, MEDLINE and PubMed databases, and references of original studies and reviews were searched for further relevant studies. The analysis comprised 510 subjects and 85 effect sizes (ESs), nested with 26 experimental and 11 control groups and 15 studies. There is a transfer between increases in lower-body strength and sprint performance as indicated by a very large significant correlation (r = -0.77; p = 0.0001) between squat strength ES and sprint ES. Additionally, the magnitude of sprint improvement is affected by the level of practice (p = 0.03) and body mass (r = 0.35; p = 0.011) of the subject, the frequency of resistance-training sessions per week (r = 0.50; p = 0.001) and the rest interval between sets of resistance-training exercises (r = -0.47; p ≤ 0.001). Conversely, the magnitude of sprint improvement is not affected by the athlete's age (p = 0.86) and height (p = 0.08), the resistance-training methods used through the training intervention, (p = 0.06), average load intensity [% of 1 repetition maximum (RM)] used during the resistance-training sessions (p = 0.34), training program duration (p = 0.16), number of exercises per session (p = 0.16), number of sets per exercise (p = 0.06) and number of repetitions per set (p = 0.48). Increases in lower-body strength transfer positively to sprint performance. The magnitude of sprint improvement is affected by numerous subject characteristics and resistance

  4. Resistance training and hormone replacement increase MMP-2 activity, quality and quantity of bone in ovariectomized rats

    Directory of Open Access Journals (Sweden)

    Markus V.C Souza

    2017-12-01

    Full Text Available Abstract AIMS The aim of the present study was to investigate the influence of resistance training (RT and hormone replacement (HR on MMP-2 activity, biomechanical and physical properties bone of ovariectomized (OVX rats. METHODS Sprague-Dawley female rats were grouped into six experimental groups (n = 11 per group: sham-operated sedentary (SHAM Sed, ovariectomized sedentary (OVX Sed, sham-operated resistance training (SHAM RT, ovariectomized resistance training (OVX RT, ovariectomized sedentary hormone replacement (OVX Sed-HR, and ovariectomized resistance training hormone replacement (OVX RT-HR. HR groups received implanted silastic capsules with a 5% solution of 17β-estradiol (50 mg 17β-estradiol/ml of sunflower oil. In a 12-week RT period (27 sessions; 4-9 climbs the animals climbed a 1.1 m vertical ladder with weights attached to their tails. Biomechanical and physical bone analyses were performed using a universal testing machine, and MMP-2 activity analysis was done by zymography. RESULTS Bone density and bone mineral content was higher in the RT and HR groups. The MMP-2 activity was higher in the RT and HR groups. The biomechanical analysis (stiffness, fracture load and maximum load demonstrated better bone tissue quality in the RT associated with HR. CONCLUSION The RT alone as well as when it is associated with HR was efficient in increasing MMP-2 activity, biomechanical and biophysical properties bone of ovariectomized rats.

  5. Cigarette smoke inhalation increases the alveolar bone loss caused by primary occlusal trauma in a rat model.

    Science.gov (United States)

    Campos, M L G; Corrêa, M G; Júnior, F H N; Casati, M Z; Sallum, E A; Sallum, A W

    2014-04-01

    Occlusal trauma (OT) and smoking are both factors that alter alveolar bone metabolism and therefore could synergistically act on alveolar bone loss. The aim of this experimental study was to evaluate the influence of short-term cigarette smoke inhalation (CSI) on inter-radicular alveolar bone loss promoted by primary OT in a rat model. Forty-eight animals were randomly assigned to one of three groups based on treatment type: OT + CSI (n = 16), animals were exposed to CSI three times per day, for 8 min per exposure, and they concomitantly received unilateral vertical augmentation creating an occlusal interference inducing experimental OT; OT (n = 16), animals received only unilateral vertical augmentation; negative control (NC; n = 16), animals maintained for equal periods to achieve periodontal baseline values of periodontal ligament dimension. Each group was divided into two subgroups (n = 8) based on treatment length: 7 or 14 d. After 7 d, the OT + CSI group exhibited significantly higher bone loss compared to the NC group (p = 0.0022). After 14 d, the OT (p < 0.0001) and OT + CSI (p < 0.0001) groups presented significantly higher bone loss compared to the NC group, and OT + CSI resulted in significantly higher bone loss than OT alone (p = 0.0241). The number of tartrate-resistant acid phosphatase-positive cells on the linear surface of the bone crest after 7 d was significantly higher in the OT + CSI group as compared to the NC and OT groups (p < 0.0001 and p = 0.0045, respectively) and remained significantly higher in the OT + CSI group after 14 d, compared to the OT group (p < 0.0001). Short-term CSI increases early bone loss in association with OT after 7 d, and this worsens in severity after 14 d of exposure. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  6. Phytase supplementation increases bone mineral density, lean body mass and voluntary physical activity in rats fed a low-zinc diet.

    Science.gov (United States)

    Scrimgeour, Angus G; Marchitelli, Louis J; Whicker, Jered S; Song, Yang; Ho, Emily; Young, Andrew J

    2010-07-01

    Phytic acid forms insoluble complexes with nutritionally essential minerals, including zinc (Zn). Animal studies show that addition of microbial phytase (P) to low-Zn diets improves Zn status and bone strength. The present study determined the effects of phytase supplementation on bone mineral density (BMD), body composition and voluntary running activity of male rats fed a high phytic acid, low-Zn diet. In a factorial design, rats were assigned to ZnLO (5 mg/kg diet), ZnLO+P (ZnLO diet with 1500 U phytase/kg) or ZnAD (30 mg/kg diet) groups and were divided into voluntary exercise (EX) or sedentary (SED) groups, for 9 weeks. SED rats were significantly heavier from the second week, and no catch-up growth occurred in EX rats. Feed intakes were not different between groups throughout the study. ZnLO animals had decreased food efficiency ratios compared to both phytase-supplemented (ZnLO+P) and Zn-adequate (ZnAD) animals (Pbone mineral content (BMC), bone area (BA) and BMD than rats fed ZnLO diets; and in rats fed ZnAD diets these indices were the highest. The dietary effects on BMC, BA and BMD were independent of activity level. We conclude that consuming supplemental dietary phytase or dietary Zn additively enhances Zn status to increase BMD, LBM and voluntary physical activity in rats fed a low-Zn diet. While the findings confirm that bone health is vulnerable to disruption by moderate Zn deficiency in rats, this new data suggests that if dietary Zn is limiting, supplemental phytase may have beneficial effects on LBM and performance activity. (c) 2010 Elsevier Inc. All rights reserved.

  7. Quantitative trait loci for tibial bone strength in C57BL/6J and C3H ...

    Indian Academy of Sciences (India)

    11 QTLs, accounting for 90% of variation for strength, have been detected. More than half QTLs ..... chromosome, major contributions seem to be in the region between marker .... ratory). The authors thank Dr Kenneth F. Manly for kindly review-.

  8. Growth hormone and bone health.

    Science.gov (United States)

    Bex, Marie; Bouillon, Roger

    2003-01-01

    Growth hormone (GH) and insulin-like growth factor-I have major effects on growth plate chondrocytes and all bone cells. Untreated childhood-onset GH deficiency (GHD) markedly impairs linear growth as well as three-dimensional bone size. Adult peak bone mass is therefore about 50% that of adults with normal height. This is mainly an effect on bone volume, whereas true bone mineral density (BMD; g/cm(3)) is virtually normal, as demonstrated in a large cohort of untreated Russian adults with childhood-onset GHD. The prevalence of fractures in these untreated childhood-onset GHD adults was, however, markedly and significantly increased in comparison with normal Russian adults. This clearly indicates that bone mass and bone size matter more than true bone density. Adequate treatment with GH can largely correct bone size and in several studies also bone mass, but it usually requires more than 5 years of continuous treatment. Adult-onset GHD decreases bone turnover and results in a mild deficit, generally between -0.5 and -1.0 z-score, in bone mineral content and BMD of the lumbar spine, radius and femoral neck. Cross-sectional surveys and the KIMS data suggest an increased incidence of fractures. GH replacement therapy increases bone turnover. The three controlled studies with follow-up periods of 18 and 24 months demonstrated a modest increase in BMD of the lumbar spine and femoral neck in male adults with adult-onset GHD, whereas no significant changes in BMD were observed in women. GHD, whether childhood- or adult-onset, impairs bone mass and strength. Appropriate substitution therapy can largely correct these deficiencies if given over a prolonged period. GH therapy for other bone disorders not associated with primary GHD needs further study but may well be beneficial because of its positive effects on the bone remodelling cycle. Copyright 2003 S. Karger AG, Basel

  9. Alterations of bone density, microstructure, and strength of the distal radius in male patients with rheumatoid arthritis: a case-control study with HR-pQCT.

    Science.gov (United States)

    Zhu, Tracy Y; Griffith, James F; Qin, Ling; Hung, Vivian W; Fong, Tsz-Ning; Au, Sze-Ki; Li, Martin; Lam, Yvonne Yi-On; Wong, Chun-Kwok; Kwok, Anthony W; Leung, Ping-Chung; Li, Edmund K; Tam, Lai-Shan

    2014-09-01

    In this cross-sectional study, we investigated volumetric bone mineral density (vBMD), bone microstructure, and biomechanical competence of the distal radius in male patients with rheumatoid arthritis (RA). The study cohort comprised 50 male RA patients of average age of 61.1 years and 50 age-matched healthy males. Areal BMD (aBMD) of the hip, lumbar spine, and distal radius was measured by dual-energy X-ray absorptiometry. High-resolution peripheral quantitative computed tomography (HR-pQCT) of the distal radius provided measures of cortical and trabecular vBMD, microstructure, and biomechanical indices. aBMD of the hip but not the lumbar spine or ultradistal radius was significantly lower in RA patients than controls after adjustment for body weight. Total, cortical, and trabecular vBMD at the distal radius were, on average, -3.9% to -23.2% significantly lower in RA patients, and these differences were not affected by adjustment for body weight, testosterone level, or aBMD at the ultradistal radius. Trabecular microstructure indices were, on average, -8.1% (trabecular number) to 28.7% (trabecular network inhomogeneity) significantly inferior, whereas cortical pore volume and cortical porosity index were, on average, 80.3% and 63.9%, respectively, significantly higher in RA patients. RA patients also had significantly lower whole-bone stiffness, modulus, and failure load, with lower and more unevenly distributed cortical and trabecular stress. Density and microstructure indices significantly correlated with disease activity, severity, and levels of pro-inflammatory cytokines (interleukin [IL] 12p70, tumor necrosis factor, IL-6 and IL-1β). Ten RA patients had focal periosteal bone apposition most prominent at the ulnovolar aspect of the distal radius. These patients had shorter disease duration and significantly higher cortical porosity. In conclusion, HR-pQCT reveals significant alterations of bone density, microstructure, and strength of the distal radius in

  10. BACK MUSCLES STRENGTH DEVELOPMENT BY MEANS OF INCREASE AND DECREASE OF EFFORT LOAD DURING GIANT SETS IN BODYBUILDING FOR MASSES

    Directory of Open Access Journals (Sweden)

    TIMNEA OLIVIA

    2013-01-01

    Full Text Available Abstract The aim of the study is to highlight methodological issues on the back muscle strength development by combining methodological procedures in masses bodybuilding.Methods. The study was conducted in three stages over a period of two months (March-April 2011, performing three workouts per week, monitoring the effective use of strength exercises to develop back muscles in the same muscle area by means of giant sets during workouts. In this context, we conducted a case study in "Tonik Fitness Club" in Bucharest, applied to two athletes of 28 and 34 years old. We recorded subjects’ evolutions during the training session, using statistical and mathematical method and graphical representation method.Results. The study content highlights the training programs depending on muscle zone and the specific methodological aspects, the weekly training program per muscle groups, the stages of study carrying out, the test and control trials applied in terms of anthropometric measurements and of back muscle strength development, and the application of the methodical procedure of effort load increase and decrease within the giant sets in a training micro-cycle.Discussion. The study focused on the training programs over two months, monitoring statistically the development of back muscle strength through the application of the procedure of effort load increase and decrease during giant sets in bodybuilding for masses. From the analysis of training programs content we noticed that three giant sets of exercises were used, performed in four series; each exercise within the giant sets was applied by means of the procedure of increasing and decreasing effort load. Study results emphasize the anthropometric measurement results: the study subjects have the age mean of 24.75, with a size of 175.2 cm and a weight of 83.75 kg at initial testing and a decrease by 2.12 kg in final testing. Regarding the chest perimeter, the inspiration is averaging 89.5 in initial

  11. Activated protein C (APC) can increase bone anabolism via a protease-activated receptor (PAR)1/2 dependent mechanism.

    Science.gov (United States)

    Shen, Kaitlin; Murphy, Ciara M; Chan, Ben; Kolind, Mille; Cheng, Tegan L; Mikulec, Kathy; Peacock, Lauren; Xue, Meilang; Park, Sang-Youel; Little, David G; Jackson, Chris J; Schindeler, Aaron

    2014-12-01

    Activated Protein C (APC) is an anticoagulant with strong cytoprotective properties that has been shown to promote wound healing. In this study APC was investigated for its potential orthopedic application using a Bone Morphogenetic Protein 2 (rhBMP-2) induced ectopic bone formation model. Local co-administration of 10 µg rhBMP-2 with 10 µg or 25 µg APC increased bone volume at 3 weeks by 32% (N.S.) and 74% (pAPC are largely mediated by its receptors endothelial protein C receptor (EPCR) and protease-activated receptors (PARs). Cultured pre-osteoblasts and bone nodule tissue sections were shown to express PAR1/2 and EPCR. When pre-osteoblasts were treated with APC, cell viability and phosphorylation of ERK1/2, Akt, and p38 were increased. Inhibition with PAR1 and sometimes PAR2 antagonists, but not with EPCR blocking antibodies, ameliorated the effects of APC on cell viability and kinase phosphorylation. These data indicate that APC can affect osteoblast viability and signaling, and may have in vivo applications with rhBMP-2 for bone repair. © 2014 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  12. SIDE TO SIDE DIFFERENCES BETWEEN DOMINANT AND NON-DOMINANT ARM'S BONE DENSITY AND ISOMETRIC HANDGRIP STRENGTH IN MALES AND FEMALES AGED 40-65 YEARS OLD.

    Science.gov (United States)

    Krasniqi, Ermira; Koni, Mynyr; Kabashi, Antigona; Bahtiri, Abedin; Gjeli, Selda; Boshnjaku, Arben

    2016-10-01

    This observational, cross-sectional study, investigates and compares the differences of BMD, T-score, Z-score and isometric strength between dominant (D) versus non-dominant (ND) arms of 162 subjects aged 40-65 in a developing, low income country (Kosova). Bone Mineral Density (BMD), T-score and Z-score at distal forearm regions of both arms (measured by DXA scan), together with the Handgrip Isometric Strength (HIS) (by handgrip) were evaluated in a total subjects (53 Males and 109 Females). Additionally, General Healthcare Status Questionnaire together with self-administrated International Physical Activity Questionnaire (IPAQ) were filled. Significant differences (p0.05) were observed in Males BMD comparing to significantly higher results (p0.05) in males. When comparing the total subject's BMD, T-score, Z-score and Handgrip based on the PA levels (1 to 3 according to IPAQ scoring) no significant differences (p>0.05) were found between PA1, as well as PA3 whereas significantly differences (p<0.05) were found in D arms of PA2 level. The study analyses side-to-side differences in bone density and muscular force between D and ND arms amongst a population which is frequently exposed to diagnostic screenings for age related osteomuscular conditions (aged 40-60), and demonstrates that these differences should be in consideration amongst clinicians, but not in the way it is done right now.

  13. Mid-thigh cortical bone structural parameters, muscle mass and strength, and association with lower limb fractures in older men and women (AGES-Reykjavik Study).

    Science.gov (United States)

    Johannesdottir, Fjola; Aspelund, Thor; Siggeirsdottir, Kristin; Jonsson, Brynjolfur Y; Mogensen, Brynjolfur; Sigurdsson, Sigurdur; Harris, Tamara B; Gudnason, Vilmundur G; Lang, Thomas F; Sigurdsson, Gunnar

    2012-05-01

    In a cross-sectional study we investigated the relationship between muscle and bone parameters in the mid-thigh in older people using data from a single axial computed tomographic section through the mid-thigh. Additionally, we studied the association of these variables with incident low-trauma lower limb fractures. A total of 3,762 older individuals (1,838 men and 1,924 women), aged 66-96 years, participants in the AGES-Reykjavik study, were studied. The total cross-sectional muscular area and knee extensor strength declined with age similarly in both sexes. Muscle parameters correlated most strongly with cortical area and total shaft area (adjusted for age, height, and weight) but explained lower limb fractures. Small muscular area, low knee extensor strength, large MA, low cortical thickness, and high BR were significantly associated with fractures in both sexes. Our results show that bone and muscle loss proceed at different rates and with different gender patterns.

  14. Increased trabecular bone and improved biomechanics in an osteocalcin-null rat model created by CRISPR/Cas9 technology

    Directory of Open Access Journals (Sweden)

    Laura J. Lambert

    2016-10-01

    Full Text Available Osteocalcin, also known as bone γ-carboxyglutamate protein (Bglap, is expressed by osteoblasts and is commonly used as a clinical marker of bone turnover. A mouse model of osteocalcin deficiency has implicated osteocalcin as a mediator of changes to the skeleton, endocrine system, reproductive organs and central nervous system. However, differences between mouse and human osteocalcin at both the genome and protein levels have challenged the validity of extrapolating findings from the osteocalcin-deficient mouse model to human disease. The rat osteocalcin (Bglap gene locus shares greater synteny with that of humans. To further examine the role of osteocalcin in disease, we created a rat model with complete loss of osteocalcin using the CRISPR/Cas9 system. Rat osteocalcin was modified by injection of CRISPR/Cas9 mRNA into the pronuclei of fertilized single cell Sprague-Dawley embryos, and animals were bred to homozygosity and compound heterozygosity for the mutant alleles. Dual-energy X-ray absorptiometry (DXA, glucose tolerance testing (GTT, insulin tolerance testing (ITT, microcomputed tomography (µCT, and a three-point break biomechanical assay were performed on the excised femurs at 5 months of age. Complete loss of osteocalcin resulted in bones with significantly increased trabecular thickness, density and volume. Cortical bone volume and density were not increased in null animals. The bones had improved functional quality as evidenced by an increase in failure load during the biomechanical stress assay. Differences in glucose homeostasis were observed between groups, but there were no differences in body weight or composition. This rat model of complete loss of osteocalcin provides a platform for further understanding the role of osteocalcin in disease, and it is a novel model of increased bone formation with potential utility in osteoporosis and osteoarthritis research.

  15. Photoperiod-Induced Increases in Bone Mineral Apposition Rate in Siberian Hamsters and the Involvement of Seasonal Leptin Changes.

    Science.gov (United States)

    Kokolski, Marie; Ebling, Francis J; Henstock, James R; Anderson, Susan I

    2017-01-01

    The adipokine leptin regulates energy balance, appetite, and reproductive maturation. Leptin also acts on bone growth and remodeling, but both osteogenic and anti-osteogenic effects have been reported depending on experimental conditions. Siberian hamsters ( Phodopus sungorus ) have natural variation in circulating leptin concentrations, where serum leptin is significantly decreased during the short day (SD)-induced winter state. In summer long day (LD) photoperiods, appetite and body adiposity increase with associated central leptin insensitivity. This natural change in leptin secretion was exploited to investigate leptin's effect on bone growth. Hamsters were injected with calcium-chelating fluorescent dyes to measure bone mineral apposition rate (MAR). Measurements were initially obtained from 5-week and 6-month-old animals maintained in low leptin (SD) or high leptin (LD) states. A further study investigated effects of chronic administration of recombinant mouse leptin to hamsters housed in SD and LD conditions; growth plate thickness and bone density were also assessed. As expected, a reduction in body mass was seen in hamsters exposed to SD, confirming the phenotype change in all studies. Serum leptin concentrations were significantly reduced in SD animals in all studies. MAR was reproducibly and significantly increased in the femurs of SD animals in all studies. Vitamin D and growth plate thickness were significantly increased in SD animals at 6 months. No effect on bone density was observed in any study. Taken together these data suggest that bone growth is associated with the low leptin, winter, lean state. In leptin-treated animals, there was a significant interaction effect of leptin and photoperiod. In comparison to their vehicle counterparts, SD animals had decreased and LD animals had increased MAR, which was not apparent prior to leptin administration. In conclusion, increased MAR was associated with low serum leptin levels in early life and

  16. Photoperiod-Induced Increases in Bone Mineral Apposition Rate in Siberian Hamsters and the Involvement of Seasonal Leptin Changes

    Directory of Open Access Journals (Sweden)

    Marie Kokolski

    2017-12-01

    Full Text Available The adipokine leptin regulates energy balance, appetite, and reproductive maturation. Leptin also acts on bone growth and remodeling, but both osteogenic and anti-osteogenic effects have been reported depending on experimental conditions. Siberian hamsters (Phodopus sungorus have natural variation in circulating leptin concentrations, where serum leptin is significantly decreased during the short day (SD-induced winter state. In summer long day (LD photoperiods, appetite and body adiposity increase with associated central leptin insensitivity. This natural change in leptin secretion was exploited to investigate leptin’s effect on bone growth. Hamsters were injected with calcium-chelating fluorescent dyes to measure bone mineral apposition rate (MAR. Measurements were initially obtained from 5-week and 6-month-old animals maintained in low leptin (SD or high leptin (LD states. A further study investigated effects of chronic administration of recombinant mouse leptin to hamsters housed in SD and LD conditions; growth plate thickness and bone density were also assessed. As expected, a reduction in body mass was seen in hamsters exposed to SD, confirming the phenotype change in all studies. Serum leptin concentrations were significantly reduced in SD animals in all studies. MAR was reproducibly and significantly increased in the femurs of SD animals in all studies. Vitamin D and growth plate thickness were significantly increased in SD animals at 6 months. No effect on bone density was observed in any study. Taken together these data suggest that bone growth is associated with the low leptin, winter, lean state. In leptin-treated animals, there was a significant interaction effect of leptin and photoperiod. In comparison to their vehicle counterparts, SD animals had decreased and LD animals had increased MAR, which was not apparent prior to leptin administration. In conclusion, increased MAR was associated with low serum leptin levels in early

  17. Increased central facilitation of antagonist reciprocal inhibition at the onset of dorsiflexion following explosive strength training

    DEFF Research Database (Denmark)

    Geertsen, Svend Sparre; Jensen, Jesper Lundbye; Nielsen, Jens Bo

    2008-01-01

    At the onset of dorsiflexion disynaptic reciprocal inhibition (DRI) of soleus motoneurons is increased to prevent activation of the antagonistic plantar flexors. This is caused by descending facilitation of transmission in the DRI pathway. Because the risk of eliciting stretch reflexes in the ankle...... of the ankle dorsiflexor muscles 3 times a week for 4 wk. Test sessions were conducted before, shortly after, and 2 wk after the training period. The rate of torque development measured at 30, 50, 100, and 200 ms after onset of voluntary explosive isometric dorsiflexion increased by 24-33% (P

  18. Performance of repetitive tasks induces decreased grip strength and increased fibrogenic proteins in skeletal muscle: role of force and inflammation.

    Directory of Open Access Journals (Sweden)

    Samir M Abdelmagid

    Full Text Available This study elucidates exposure-response relationships between performance of repetitive tasks, grip strength declines, and fibrogenic-related protein changes in muscles, and their link to inflammation. Specifically, we examined forearm flexor digitorum muscles for changes in connective tissue growth factor (CTGF; a matrix protein associated with fibrosis, collagen type I (Col1; a matrix component, and transforming growth factor beta 1 (TGFB1; an upstream modulator of CTGF and collagen, in rats performing one of two repetitive tasks, with or without anti-inflammatory drugs.To examine the roles of force versus repetition, rats performed either a high repetition negligible force food retrieval task (HRNF, or a high repetition high force handle-pulling task (HRHF, for up to 9 weeks, with results compared to trained only (TR-NF or TR-HF and normal control rats. Grip strength declined with both tasks, with the greatest declines in 9-week HRHF rats. Quantitative PCR (qPCR analyses of HRNF muscles showed increased expression of Col1 in weeks 3-9, and CTGF in weeks 6 and 9. Immunohistochemistry confirmed PCR results, and also showed greater increases of CTGF and collagen matrix in 9-week HRHF rats than 9-week HRNF rats. ELISA, and immunohistochemistry revealed greater increases of TGFB1 in TR-HF and 6-week HRHF, compared to 6-week HRNF rats. To examine the role of inflammation, results from 6-week HRHF rats were compared to rats receiving ibuprofen or anti-TNF-α treatment in HRHF weeks 4-6. Both treatments attenuated HRHF-induced increases in CTGF and fibrosis by 6 weeks of task performance. Ibuprofen attenuated TGFB1 increases and grip strength declines, matching our prior results with anti-TNFα.Performance of highly repetitive tasks was associated with force-dependent declines in grip strength and increased fibrogenic-related proteins in flexor digitorum muscles. These changes were attenuated, at least short-term, by anti-inflammatory treatments.

  19. Acute Responses of Strength and Running Mechanics to Increasing and Decreasing Pain in Patients With Patellofemoral Pain

    Science.gov (United States)

    Bazett-Jones, David M.; Huddleston, Wendy; Cobb, Stephen; O'Connor, Kristian; Earl-Boehm, Jennifer E.

    2017-01-01

    Context:  Patellofemoral pain (PFP) is typically exacerbated by repetitive activities that load the patellofemoral joint, such as running. Understanding the mediating effects of changes in pain in individuals with PFP might inform injury progression, rehabilitation, or both. Objective:  To investigate the effects of changing pain on muscular strength and running biomechanics in those with PFP. Design:  Crossover study. Setting:  University research laboratory. Patients or Other Participants:  Seventeen participants (10 men, 7 women) with PFP. Intervention(s):  Each participant completed knee pain-reducing and pain-inducing protocols in random order. The pain-reducing protocol consisted of 15 minutes of transcutaneous electric nerve stimulation (TENS) around the patella. The pain-inducing protocol was sets of 20 repeated single-legged squats (RSLS). Participants completed RSLS sets until either their pain was within at least 1 cm of their pain during an exhaustive run or they reached 10 sets. Main Outcome Measure(s):  Pain, isometric hip and trunk strength, and running mechanics were assessed before and after the protocols. Dependent variables were pain, normalized strength (abduction, extension, external rotation, lateral trunk flexion), and peak lower extremity kinematics and kinetics in all planes. Pain scores were analyzed using a Friedman test. Strength and mechanical variables were analyzed using repeated-measures analyses of variance. The α level was set at P < .05. Results:  Pain was decreased after the TENS (pretest: 3.10 ± 1.95, posttest: 1.89 ± 2.33) and increased after the RSLS (baseline: 3.10 ± 1.95, posttest: 4.38 ± 2.40) protocols (each P < .05). The RSLS protocol resulted in a decrease in hip-extension strength (baseline: 0.355 ± 0.08 kg/kg, posttest: 0.309 ± 0.09 kg/kg; P < .001). Peak plantar-flexion angle was decreased after RSLS (baseline: −13.97° ± 6.41°, posttest: −12.84° ± 6.45°; P = .003). Peak hip

  20. Rational design of a high-strength bone scaffold platform based on in situ hybridization of bacterial cellulose/nano-hydroxyapatite framework and silk fibroin reinforcing phase.

    Science.gov (United States)

    Jiang, Pei; Ran, Jiabing; Yan, Pan; Zheng, Lingyue; Shen, Xinyu; Tong, Hua

    2018-02-01

    Bacterial cellulose/hydroxyapatite (BC/HAp) composite had favourable bioaffinity but its poor mechanical strength limited its widespread applications in bone tissue engineering (BTE). Silk fibroin, which possesses special crystalline structure, has been widely used as organic reinforcing material, and different SFs have different amino acid sequences, which exhibit different bioaffinity and mechanical properties. In this regard, bacterial cellulose-Antheraea yamamai silk fibroin/hydroxyapatite (BC-AYSF/HAp), bacterial cellulose-Bombyx mori silk fibroin/hydroxyapatite (BC-BMSF/HAp), and BC/HAp nano-composites were synthesized via a novel in situ hybridization method. Compared with BC/HAp and BC-BMSF/HAp, the BC-AYSF/HAp exhibited better interpenetration, which may benefit for the transportation of nutrients and wastes, the adhesion of cells as well. Additionally, the BC-AYSF/HAp also presented superior thermal stability than the other two composites revealed by differential thermal analysis (DTA) and thermogravimetric analysis (TGA). Compression testing indicated that the mechanical strength of BC-BMSF/HAp was greatly reinforced compared with BC/HAp and was even a little higher than that of BC-AYSF/HAp. Tensile testing showed that BC-AYSF/HAp possesses extraordinary mechanical properties with a higher elastic modulus at low strain and higher fracture strength simultaneously than the other two composites. In vitro cell culture exhibited that MC3T3-E1 cells on the BC-AYSF/HAp membrane took on higher proliferative potential than those on the BC-BMSF/HAp membrane. These results suggested that compared with BC-BMSF/HAp, the BC-AYSF/HAp composite was more appropriate as an ideal bone scaffold platform or biomedical membrane to be used in BTE.

  1. Nanogel-crosslinked nanoparticles increase the inhibitory effects of W9 synthetic peptide on bone loss in a murine bone resorption model

    Directory of Open Access Journals (Sweden)

    Sato T

    2015-05-01

    Full Text Available Toshimi Sato,1 Neil Alles,1,2 Masud Khan,1,3 Kenichi Nagano,1,4 Mariko Takahashi,1 Yukihiko Tamura,1 Asako Shimoda,5,6 Keiichi Ohya,1 Kazunari Akiyoshi,5,6 Kazuhiro Aoki1 1Department of Bio-Matrix (Pharmacology, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan; 2Department of Biochemistry, Faculty of Medicine, University of Peradeniya, Peradeniya, Sri Lanka; 3Department of Dental Pharmacology, City Dental College and Hospital, Dhaka, Bangladesh; 4Department of Oral Medicine, Infection and Immunity, Harvard School of Dental Medicine, Boston, MA, USA; 5Department of Polymer Chemistry, Graduate School of Engineering, Kyoto University, Katsura, 6ERATO Akiyoshi Bio-Nanotransporter Project, Japan Science and Technology Agency, Katsura Int’tech Center Kyotodaigaku-Katsura, Nishikyo-ku, Kyoto, Japan Abstract: We investigated the biological activity of W9, a bone resorption inhibitor peptide, using NanoClik nanoparticles as an injectable carrier, where acryloyl group-modified cholesterol-bearing pullulan (CHPOA nanogels were crosslinked by pentaerythritol tetra (mercaptoethyl polyoxyethylene. Thirty 5-week-old male C57BL/6J mice were fed a low calcium diet and received once-daily subcutaneous injections of the carrier alone, W9 24 mg/kg/day alone, W9 24 mg/kg/day incorporated in cholesterol bearing pullulan (CHP nanogels, or W9 (8 and 24 mg/kg/day incorporated in NanoClik nanoparticles for 4 days (n=5. Mice that received a normal calcium diet with NanoClik nanoparticle injections without W9 were used as a control group. Radiological analyses showed that administration of W9 24 mg/kg/day significantly prevented low calcium-induced reduction of bone mineral density in the long bones and lumbar vertebrae, but only when the NanoClik nanoparticles were used as a carrier. Histomorphometric analyses of the proximal tibiae revealed that W9 24 mg/kg/day incorporated in NanoClik nanoparticles prevented the increase in bone resorption indices

  2. Perceptual learning increases the strength of the earliest signals in visual cortex.

    Science.gov (United States)

    Bao, Min; Yang, Lin; Rios, Cristina; He, Bin; Engel, Stephen A

    2010-11-10

    Training improves performance on most visual tasks. Such perceptual learning can modify how information is read out from, and represented in, later visual areas, but effects on early visual cortex are controversial. In particular, it remains unknown whether learning can reshape neural response properties in early visual areas independent from feedback arising in later cortical areas. Here, we tested whether learning can modify feedforward signals in early visual cortex as measured by the human electroencephalogram. Fourteen subjects were trained for >24 d to detect a diagonal grating pattern in one quadrant of the visual field. Training improved performance, reducing the contrast needed for reliable detection, and also reliably increased the amplitude of the earliest component of the visual evoked potential, the C1. Control orientations and locations showed smaller effects of training. Because the C1 arises rapidly and has a source in early visual cortex, our results suggest that learning can increase early visual area response through local receptive field changes without feedback from later areas.

  3. THE TECHNOLOGICAL AND EXPLOITATIVE FACTORS OF LOCAL INCREASE OF ELECTRIC FIELD STRENGTH IN THE POWER CABLE OF COAXIAL DESIGN

    Directory of Open Access Journals (Sweden)

    G. V. Bezprozvannych

    2016-12-01

    different effects on the distribution of the electrical field strength at the conductor and the insulation. The electrical field strength is increased by 50 % in the core and 17 % - on the surface of the insulation at 10 % eccentricity between conductor and insulation. Availability elliptic insulation leads to a redistribution of the electric field: field strength at the surface of the insulation is 2 times higher electric field strength on the surface of the conductor. Water treeing spherical shape filled with water with a dielectric constant of 6.9, lead to a local increase of electric field intensity is 5 - 10 times. Originality. Simulation results show that the presence of water treeing concentrated with individual heterogeneity characteristic impedance causes a change in shape and duration of the probe signal rectangular. Practical value. Time domain reflectometer can be considered as one of the promising methods for diagnosing operational irregularities (ellipticity, eccentricity, water treeing in power cables.

  4. Addition of blood to a phycogenic bone substitute leads to increased in vivo vascularization

    International Nuclear Information System (INIS)

    Barbeck, Mike; Sader, Robert; Ghanaati, Shahram; Najman, Stevo; Stojanović, Sanja; Živković, Jelena M; Mitić, Žarko; Choukroun, Joseph; Kovačević, Predrag; James Kirkpatrick, C

    2015-01-01

    The present study aimed to analyze the effects of the addition of blood to the phycogenic bone substitute Algipore ® on the severity of in vivo tissue reaction. Initially, Fourier-transform infrared spectroscopy (FTIR) of the bone substitute was conducted to analyze its chemical composition. The subcutaneous implantation model in Balb/c mice was then applied for up to 30 d to analyze the tissue reactions on the basis of specialized histochemical, immunohistochemical, and histomorphometrical methods. The data of the FTIR analysis showed that the phycogenic bone substitute material is mainly composed of hydroxyapatite with some carbonate content. The in vivo analyses revealed that the addition of blood to Algipore ® had a major impact on both angiogenesis and vessel maturation. The higher vascularization seemed to be based on significantly higher numbers of multinucleated TRAP-positive cells. However, mostly macrophages and a relatively low number of multinucleated giant cells were involved in the tissue reaction to Algipore ® . The presented data show that the addition of blood to a bone substitute impacts the tissue reaction to it. In particular, the immune response and the vascularization were influenced, and these are believed to have a major impact on the regenerative potential of the process of bone tissue regeneration. (paper)

  5. Loss of TGF-β signaling in osteoblasts increases basic-FGF and promotes prostate cancer bone metastasis.

    Science.gov (United States)

    Meng, Xiangqi; Vander Ark, Alexandra; Daft, Paul; Woodford, Erica; Wang, Jie; Madaj, Zachary; Li, Xiaohong

    2018-04-01

    TGF-β plays a central role in prostate cancer (PCa) bone metastasis, and it is crucial to understand the bone cell-specific role of TGF-β signaling in this process. Thus, we used knockout (KO) mouse models having deletion of the Tgfbr2 gene specifically in osteoblasts (Tgfbr2 Col1CreERT KO) or in osteoclasts (Tgfbr2 LysMCre KO). We found that PCa-induced bone lesion development was promoted in the Tgfbr2 Col1CreERT KO mice, but was inhibited in the Tgfbr2 LysMCre KO mice, relative to their respective control Tgfbr2 FloxE2 littermates. Since metastatic PCa cells attach to osteoblasts when colonized in the bone microenvironment, we focused on the mechanistic studies using the Tgfbr2 Col1CreERT KO mouse model. We found that bFGF was upregulated in osteoblasts from PC3-injected tibiae of Tgfbr2 Col1CreERT KO mice and correlated with increased tumor cell proliferation, angiogenesis, amounts of cancer-associated fibroblasts and osteoclasts. In vitro studies showed that osteoblastogenesis was inhibited, osteoclastogenesis was stimulated, but PC3 viability was not affected, by bFGF treatments. Lastly, the increased PC3-induced bone lesions in Tgfbr2 Col1CreERT KO mice were significantly attenuated by blocking bFGF using neutralizing antibody, suggesting bFGF is a promising target inhibiting bone metastasis. Copyright © 2018 Elsevier B.V. All rights reserved.

  6. Physical activity effects on bone metabolism.

    Science.gov (United States)

    Smith, E L; Gilligan, C

    1991-01-01

    The incidence of osteoporotic fractures rises exponentially with age and is increasing faster than the demographic increase in the aging population. Physical activity has great potential to reduce the risk for osteoporotic fractures. Three independent but interactive factors contribute to the risk of fractures: bone strength, the risk of falling, and the effectiveness of neuromuscular response that protects the skeleton from injury. Exercise can reduce fracture risk not only by preventing bone loss, but by decreasing the risk of falling and the force of impact by improving strength, flexibility, balance, and reaction time. Extreme inactivity causes rapid bone loss of up to 40%, while athletic activity results in bone hypertrophy of up to 40%. Exercise intervention programs have reduced bone loss or increased bone mass in both men and women of various ages and initial bone status. These benefits have been shown for arm bone mineral content, total body calcium, spine, calcium bone index, tibia, and calcaneus. In both middle-aged and elderly women, physical activity intervention reduced bone loss or increased bone mass. The mechanisms for maintenance of skeletal integrity rely on a cellular response to hormonal and mechanical load stimuli. Studies in animal models show that training affects cellular activity. In osteoporotics, cellular erosion is increased and mineral apposition rate (MAR) decreased compared with normal age-matched controls. In contrast to this, sows trained on a treadmill 20 min per day for 20 weeks had greater active periosteal surface, periosteal MAR, and osteonal MAR than untrained sows.

  7. SPECT/spiral-CT hybrid imaging in unclear foci of increased bone metabolism: a case report

    Energy Technology Data Exchange (ETDEWEB)

    Roemer, W.; Kuwert, T. [Nuklearmedizinische Klinik, Friedrich-Alexander-Univ. Erlangen/Nuernberg (Germany); Beckmann, M.W. [Frauenklinik, Friedrich-Alexander-Univ. Erlangen/Nuernberg (Germany); Forst, R. [Lehrstuhl fuer Orthopaedie mit Orthopaedischer Chirurgie, Friedrich-Alexander Univ. Erlangen/Nuernberg (Germany); Bautz, W. [Radiologisches Inst., Friedrich-Alexander-Univ. Erlangen/Nuernberg (Germany)

    2005-07-01

    In bone scintigraphy, the differentiation between degenerative processes and bone metastases is still difficult. Therefore, additional radiological studies are regularly needed after bone scintigraphy. The now introduced hybrid-cameras combining single-photon emission computed tomography (SPECT) and spiral-CT are unique in the sense that they offer the opportunity to correlate the functional information with morphology in one session. We herein present two patients in whom this technological setup allowed a definite diagnosis in scintigraphically unclear vertebral lesions. In a patient with breast cancer, hypermetabolic lesions were clearly correlated with osteolyses. In another patient with synovial carcinoma, spondylosis and spondylarthrosis caused focal tracer uptake in the lumbar spine. In addition to an improved diagnostic accuracy, SPECT/Spiral-CT will considerably abbreviate the diagnostic process. (orig.)

  8. SPECT/spiral-CT hybrid imaging in unclear foci of increased bone metabolism: a case report

    International Nuclear Information System (INIS)

    Roemer, W.; Kuwert, T.; Beckmann, M.W.; Forst, R.; Bautz, W.

    2005-01-01

    In bone scintigraphy, the differentiation between degenerative processes and bone metastases is still difficult. Therefore, additional radiological studies are regularly needed after bone scintigraphy. The now introduced hybrid-cameras combining single-photon emission computed tomography (SPECT) and spiral-CT are unique in the sense that they offer the opportunity to correlate the functional information with morphology in one session. We herein present two patients in whom this technological setup allowed a definite diagnosis in scintigraphically unclear vertebral lesions. In a patient with breast cancer, hypermetabolic lesions were clearly correlated with osteolyses. In another patient with synovial carcinoma, spondylosis and spondylarthrosis caused focal tracer uptake in the lumbar spine. In addition to an improved diagnostic accuracy, SPECT/Spiral-CT will considerably abbreviate the diagnostic process. (orig.)

  9. Dietary arginine silicate inositol complex increased bone healing: histologic and histomorphometric study

    Directory of Open Access Journals (Sweden)

    Yaman F

    2016-06-01

    Full Text Available Ferhan Yaman,1 Izzet Acikan,1 Serkan Dundar,2 Sercan Simsek,3 Mehmet Gul,4 İbrahim Hanifi Ozercan,3 James Komorowski,5 Kazim Sahin6 1Department of Oral-Maxillofacial Surgery, Faculty of Dentistry, Dicle University, Diyarbakir, Turkey; 2Department of Periodontology, Faculty of Dentistry, Firat University, Elazig, Turkey; 3Department of Pathology, Faculty of Medicine, Firat University, Elazig, Turkey; 4Department of Periodontology, Faculty of Dentistry, Dicle University, Diyarbakir, Turkey; 5Nutrition 21, LLC, Purchase, NY, USA; 6Department of Animal Nutrition, Faculty of Veterinary Medicine, Firat University, Elazig, Turkey Background: Arginine silicate inositol complex (ASI; arginine 49.5%, silicon 8.2%, and inositol 25% is a novel material that is a bioavailable source of silicon and arginine. ASI offers potential benefits for vascular and bone health. Objective: The aim of this study was to evaluate the potential effects of ASI complex on bone healing of critical-sized defects in rats. Methods: The rats were randomly assigned to two groups of 21 rats each. The control group was fed a standard diet for 12 weeks; after the first 8 weeks, a calvarial critical-sized defect was created, and the rats were sacrificed 7, 14, and 28 days later. The ASI group was fed a diet containing 1.81 g/kg of ASI for 12 weeks; after the first 8 weeks, a calvarial critical-sized defect was created, and the rats were sacrificed 7, 14, and 28 days later. The calvarial bones of all the rats were then harvested for evaluation. Results: Osteoblasts and osteoclasts were detected at higher levels in the ASI group compared with the control group at days 7, 14, and 28 of the calvarial defect (P<0.05. New bone formation was detected at higher levels in the ASI group compared with the controls at day 28 (P<0.05. However, new bone formation was not detected at days 7 and 14 in both the groups (P>0.05. Conclusion: ASI supplementation significantly improved bone tissue

  10. Serotonin and Histamine Therapy Increases Tetanic Forces of Myoblasts, Reduces Muscle Injury, and Improves Grip Strength Performance of Dmdmdx Mice

    Directory of Open Access Journals (Sweden)

    Volkan Gurel

    2015-11-01

    Full Text Available Duchenne muscular dystrophy (DMD is a recessive X-linked fatal disorder caused by a mutation in the dystrophin gene. Although several therapeutic approaches have been studied, none has led to substantial long-term effects in patients. The aim of this study was to test a serotonin and histamine (S&H combination on human skeletal myoblasts and Dmdmdx mice for its effects on muscle strength and injury. Normal human bioartificial muscles (BAMs were treated, and muscle tetanic forces and muscle injury tests were performed using the MyoForce Analysis System. Dmdmdx mice, the murine model of DMD, were administered serotonin, histamine, or S&H combination twice daily for 6 weeks, and functional performance tests were conducted once a week. The S&H combination treatment caused significant increases in tetanic forces at all time points and concentrations tested as compared to the saline controls. Dose response of the BAMs to the treatment demonstrated a significant increase in force generation at all concentrations compared to the controls after 3 to 4 days of drug treatment. The highest 3 concentrations had a significant effect on lowering contractile-induced injury as measured by a reduction in the release of adenylate kinase. Histamine-only and S&H treatments improved grip strength of Dmdmdx mice, whereas serotonin-only treatment resulted in no significant improvement in muscle strength. The results of this study indicate that S&H therapy might be a promising new strategy for muscular dystrophies and that the mechanism should be further investigated.

  11. Increased presence of capillaries next to remodeling sites in adult human cancellous bone

    DEFF Research Database (Denmark)

    Kristensen, Helene Bjoerg; Andersen, Thomas Levin; Marcussen, Niels

    2013-01-01

    and at the level of the light-microscopically assessed contact of these three entities with the bone or canopy surfaces. Between 51 and 100 microm, their densities leveled to that found above quiescent surfaces. Electron microscopy asserted the close proximity between BRC canopies and capillaries lined...

  12. Estrogens increase expression of bone morphogenetic protein 8b in brown adipose tissue of mice

    NARCIS (Netherlands)

    A. Grefhorst (Aldo); J.C. van den Beukel (Anneke); A.F. van Houten (A.); J. Steenbergen (Jacobie); J.A. Visser (Jenny); A.P.N. Themmen (Axel)

    2015-01-01

    textabstractBackground: In mammals, white adipose tissue (WAT) stores fat and brown adipose tissue (BAT) dissipates fat to produce heat. Several studies showed that females have more active BAT. Members of the bone morphogenetic protein (BMP) and fibroblast growth factor (FGF) families are expressed

  13. Bone Resorption Is Increased in Pheochromocytoma Patients and Normalizes following Adrenalectomy

    NARCIS (Netherlands)

    Veldhuis-Vlug, A.G.; El Mahdiui, M.; Endert, E.; Heijboer, A.C.; Fliers, E.; Bisschop, P.H.

    2012-01-01

    Context: The sympathetic nervous system (SNS) controls bone turnover in rodents, but it is uncertain whether a similar role for the SNS exists in humans. Pheochromocytomas are catecholamine-producing neuroendocrine tumors. Because catecholamines are the neurotransmitters of the SNS, we hypothesized

  14. Astragalus Extract Mixture HT042 Increases Longitudinal Bone Growth Rate by Upregulating Circulatory IGF-1 in Rats

    Directory of Open Access Journals (Sweden)

    Donghun Lee

    2017-01-01

    Full Text Available Astragalus extract mixture HT042 is a standardized ingredient of health functional food approved by Korean FDA with a claim of “height growth of children.” HT042 stimulates bone growth rate and increases local IGF-1 expression in growth plate of rats which can be considered as direct stimulation of GH and its paracrine/autocrine actions. However, it remains unclear whether HT042 stimulates circulatory IGF-1 which also plays a major role to stimulate bone growth. To determine the effects on circulatory IGF-1, IGF-1 and IGFBP-3 expressions and phosphorylation of JAK2/STAT5 were evaluated in the liver after 10 days of HT042 administration. HT042 upregulated liver IGF-1 and IGFBP-3 mRNA expression, IGF-1 protein expression, and phosphorylation of JAK2/STAT5. HT042 also increased bone growth rate and proliferative zonal height in growth plate. In conclusion, HT042 stimulates bone growth rate via increment of proliferative rate by upregulation of liver IGF-1 and IGFBP-3 mRNA followed by IGF-1 protein expression through phosphorylation of JAK2/STAT5, which can be regarded as normal functioning of GH-dependent endocrine pathway.

  15. Dramatic Enhancement of Graphene Oxide/Silk Nanocomposite Membranes: Increasing Toughness, Strength, and Young's modulus via Annealing of Interfacial Structures.

    Science.gov (United States)

    Wang, Yaxian; Ma, Ruilong; Hu, Kesong; Kim, Sunghan; Fang, Guangqiang; Shao, Zhengzhong; Tsukruk, Vladimir V

    2016-09-21

    We demonstrate that stronger and more robust nacre-like laminated GO (graphene oxide)/SF (silk fibroin) nanocomposite membranes can be obtained by selectively tailoring the interfacial interactions between "bricks"-GO sheets and "mortar"-silk interlayers via controlled water vapor annealing. This facial annealing process relaxes the secondary structure of silk backbones confined between flexible GO sheets. The increased mobility leads to a significant increase in ultimate strength (by up to 41%), Young's modulus (up to 75%) and toughness (up to 45%). We suggest that local silk recrystallization is initiated in the proximity to GO surface by the hydrophobic surface regions serving as nucleation sites for β-sheet domains formation and followed by SF assembly into nanofibrils. Strong hydrophobic-hydrophobic interactions between GO layers with SF nanofibrils result in enhanced shear strength of layered packing. This work presented here not only gives a better understanding of SF and GO interfacial interactions, but also provides insight on how to enhance the mechanical properties for the nacre-mimic nanocomposites by focusing on adjusting the delicate interactions between heterogeneous "brick" and adaptive "mortar" components with water/temperature annealing routines.

  16. Quantitative dual-energy CT for phantomless evaluation of cancellous bone mineral density of the vertebral pedicle: correlation with pedicle screw pull-out strength

    Energy Technology Data Exchange (ETDEWEB)

    Wichmann, Julian L.; Booz, Christian; Bauer, Ralf W.; Kerl, J.M.; Fischer, Sebastian; Lehnert, Thomas; Vogl, Thomas J.; Khan, M.F. [University Hospital Frankfurt, Department of Diagnostic and Interventional Radiology, Frankfurt am Main (Germany); Wesarg, Stefan [Fraunhofer IGD, Cognitive Computing and Medical Imaging, Darmstadt (Germany); Kafchitsas, Konstantinos [Spine Center, Asklepios Klinik Lindenlohe, Schwandorf (Germany)

    2015-06-01

    To evaluate quantitative dual-energy computed tomography (DECT) for phantomless analysis of cancellous bone mineral density (BMD) of vertebral pedicles and to assess the correlation with pedicle screw pull-out strength. Twenty-nine thoracic and lumbar vertebrae from cadaver specimens were examined with DECT. Using dedicated post-processing software, a pedicle screw vector was mapped (R1, intrapedicular segment of the pedicle vector; R2, intermediate segment; R3, intracorporal segment; global, all segments) and BMD was calculated. To invasively evaluate pedicle stability, pedicle screws were drilled through both pedicles and left pedicle screw pull-out strength was measured. Resulting values were correlated using the paired t test and Pearson's linear correlation. Average pedicle screw vector BMD (R1, 0.232 g/cm{sup 3}; R2, 0.166 g/cm{sup 3}; R3, 0.173 g/cm{sup 3}; global, 0.236 g/cm{sup 3}) showed significant differences between R1-R2 (P < 0.002) and R1-R3 (P < 0.034) segments while comparison of R2-R3 did not reach significance (P > 0.668). Average screw pull-out strength (639.2 N) showed a far stronger correlation with R1 (r = 0.80; P < 0.0001) than global BMD (r = 0.42; P = 0.025), R2 (r = 0.37; P = 0.048) and R3 (r = -0.33; P = 0.078) segments. Quantitative DECT allows for phantomless BMD assessment of the vertebral pedicle. BMD of the intrapedicular segment shows a significantly stronger correlation with pedicle screw pull-out strength than other segments. (orig.)

  17. Assessment of the possibility of increasing a load - carrying strength of truss bridges of overhead travelling cranes

    Directory of Open Access Journals (Sweden)

    Michał MUSIOŁ

    2012-01-01

    Full Text Available A possibility of increasing the load-carrying strength of truss bridges of overhead travelling cranes by transferring a part of a useful load from the main truss (which transfers directly the load originated from road wheels of the crane carriage on the parallel auxiliary truss by means of increasing rigidity of truss members joining both trusses - was presented in the paper. The verification of a static relief of the main truss by the auxiliary one as a function of rigidity of transverse and skew space trusses was performed. The A. Blum method was used in analytical calculations. The obtained results were verified by means of the ANSYS 12.1 program utilising the finite element method (FEM.

  18. Three-fold increase of M1 strength in 40Ar at 10 MeV excitation energy

    Science.gov (United States)

    Tornow, Werner; Finch, Sean; Krishichayan, Fnu; Tonchev, Anton

    2017-09-01

    We reexamined the excitation energy region of 40Ar around 9.8 MeV with the goal of determining the known M1 strength located at 9.76 MeV more accurately. The physics motivation was based on the fact that i) the neutrino-nucleus interaction cross section is proportional to the M1 strength of a nucleus, ii) DUNE, the Deep Underground Neutrino Experiment at SURF will be using liquid argon as detector medium, iii) the energy spectrum of supernova neutrinos is peaked at approximately 10 MeV. Mono-energetic and linearly polarized photons of 9.88 MeV were produced via Compton backscattering of 548 nm FEL photons from 543 MeV electrons at the High-Intensity γ-ray Source (HI γS) facility at TUNL. The 1.25 cm diameter photon beam with energy spread of 300 keV (FWHM) interacted with argon gas contained in a high-pressure cell. The cell was viewed with HPGe detectors placed at 90o relative to the incident photon beam in the horizontal and vertical planes to distinguish between E1 and M1 de-excitation γ-rays. Our re-measurement provided an increase in M1 strength by a factor of approximately 3, mostly due to the discovery that the known level in 40Ar at 9.84 MeV is of M1 character and not of E1 character, as previously thought. In addition to the already known M1 state at 9.76 MeV, we observed weaker M1 states at 9.70, 9.81, 9.87, and 9.89 MeV.

  19. An insight in to Paget′s disease of bone

    Directory of Open Access Journals (Sweden)

    Robin Sabharwal

    2014-01-01

    Full Text Available Paget′s disease of bone (PDB is a common disorder which may affect one or many bones. Although many patients are asymptomatic, a variety of symptoms and complications may occur. PDB is a focal disorder of bone turnover characterized by excessive bone resorption coupled with bone formation. PDB begins with a period of increased osteoclastic activity and bone resorption, followed by increased osteoblast production of woven bone that is poorly mineralized. In the final phase of the disease process, dense cortical and trabecular bone deposition predominates, but the bone is sclerotic and poorly organized and lacks the structural integrity and strength of normal bone. This article briefly reviews the etiopathogenesis, clinical radiographic and histological features of Paget′s disease.

  20. Potassium citrate prevents increased osteoclastogenesis resulting from acidic conditions: Implication for the treatment of postmenopausal bone loss.

    Directory of Open Access Journals (Sweden)

    Donatella Granchi

    Full Text Available The extracellular acidic milieu in bones results in activation of osteoclasts (OC and inhibition of osteoblasts (OB causing a net loss of calcium from the skeleton and the deterioration of bone microarchitecture. Alkalinization through supplementation with potassium citrate (K citrate has been proposed to limit the osteopenia progression, even though its pharmacological activity in bone microenvironment is not well defined. We evaluated if K citrate was able to prevent the adverse effects that acidic milieu induces on bone cells. OC and OB were maintained in neutral (pH 7.4 versus acidic (pH 6.9 culture medium, and treated with different K citrate concentrations. We evaluated the OC differentiation at seven days, by counting of multinucleated cells expressing tartrate-resistant acid phosphatase, and the activity of mature OC at 14 days, by quantifying of collagen degradation. To evaluate the effects on OB, we analyzed proliferation, mineralization, and expression of bone-related genes. We found that the low pH increased OC differentiation and activity and decreased OB function. The osteoclastogenesis was also promoted by RANKL concentrations ineffective at pH 7.4. Non-cytotoxic K citrate concentrations were not sufficient to steadily neutralize the acidic medium, but a inhibited the osteoclastogenesis, the collagen degradation, and the expression of genes involved in RANKL-mediated OC differentiation, b enhanced OB proliferation and alkaline phosphatase expression, whereas it did not affect the in vitro mineralization, and c were effective also in OC cultures resistant to alendronate, i.e. the positive control of osteoclastogenesis inhibition. In conclusion, K citrate prevents the increase in OC activity induced by the acidic microenvironment, and the effect does not depend exclusively on its alkalizing capacity. These data provide the biological basis for the use of K citrate in preventing the osteopenia progression resulting from low

  1. High Insulin Levels in KK-Ay Diabetic Mice Cause Increased Cortical Bone Mass and Impaired Trabecular Micro-Structure

    Directory of Open Access Journals (Sweden)

    Cen Fu

    2015-04-01

    Full Text Available Type 2 diabetes mellitus (T2DM is a chronic disease characterized by hyperglycemia, hyperinsulinemia and complications, including obesity and osteoporosis. Rodents have been widely used to model human T2DM and investigate its effect on the skeleton. We aimed to investigate skeletal alterations in Yellow Kuo Kondo (KK-Ay diabetic mice displaying high insulin and glucose levels. Bone mineral density (BMD, micro-architecture and bone metabolism-related genes were analyzed. The total femoral areal BMD (aBMD, cortical volumetric BMD (vBMD and thickness were significantly increased in KK-Ay mice, while the trabecular vBMD and mineralized bone volume/tissue volume (BV/TV, trabecular thickness and number were decreased compared to C57BL mice. The expression of both osteoblast-related genes, such as osteocalcin (OC, bone sialoprotein, Type I Collagen, osteonectin, RUNX2 and OSX, and osteoclast-related genes, such as TRAP and TCIRG, were up-regulated in KK-Ay mice. Correlation analyses showed that serum insulin levels were positively associated with aBMD, cortical vBMD and thickness and negatively associated with trabecular vBMD and micro-architecture. In addition, serum insulin levels were positively related to osteoblast-related and osteoclast-related gene expression. Our data suggest that high insulin levels in KK-Ay diabetic mice may increase cortical bone mass and impair trabecular micro-structure by up-regulating osteoblast-and osteoclast-related gene expression.

  2. A poly(glycerol sebacate)-coated mesoporous bioactive glass scaffold with adjustable mechanical strength, degradation rate, controlled-release and cell behavior for bone tissue engineering.

    Science.gov (United States)

    Lin, Dan; Yang, Kai; Tang, Wei; Liu, Yutong; Yuan, Yuan; Liu, Changsheng

    2015-07-01

    Various requirements in the field of tissue engineering have motivated the development of three-dimensional scaffold with adjustable physicochemical properties and biological functions. A series of multiparameter-adjustable mesoporous bioactive glass (MBG) scaffolds with uncrosslinked poly(glycerol sebacate) (PGS) coating was prepared in this article. MBG scaffold was prepared by a modified F127/PU co-templating process and then PGS was coated by a simple adsorption and lyophilization process. Through controlling macropore parameters and PGS coating amount, the mechanical strength, degradation rate, controlled-release and cell behavior of the composite scaffold could be modulated in a wide range. PGS coating successfully endowed MBG scaffold with improved toughness and adjustable mechanical strength covering the bearing range of trabecular bone (2-12MPa). Multilevel degradation rate of the scaffold and controlled-release rate of protein from mesopore could be achieved, with little impact on the protein activity owing to an "ultralow-solvent" coating and "nano-cavity entrapment" immobilization method. In vitro studies indicated that PGS coating promoted cell attachment and proliferation in a dose-dependent manner, without affecting the osteogenic induction capacity of MBG substrate. These results first provide strong evidence that uncrosslinked PGS might also yield extraordinary achievements in traditional MBG scaffold. With the multiparameter adjustability, the composite MBG/PGS scaffolds would have a hopeful prospect in bone tissue engineering. The design considerations and coating method of this study can also be extended to other ceramic-based artificial scaffolds and are expected to provide new thoughts on development of future tissue engineering materials. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Effects of Spaceflight on Bone: The Rat as an Animal Model for Human Bone Loss

    Science.gov (United States)

    Halloran, B.; Weider, T.; Morey-Holton, E.

    1999-01-01

    The loss of weight bearing during spaceflight results in osteopenia in humans. Decrements in bone mineral reach 3-10% after as little as 75-184 days in space. Loss of bone mineral during flight decreases bone strength and increases fracture risk. The mechanisms responsible for, and the factors contributing to, the changes in bone induced by spaceflight are poorly understood. The rat has been widely used as an animal model for human bone loss during spaceflight. Despite its potential usefulness, the results of bone studies performed in the rat in space have been inconsistent. In some flights bone formation is decreased and cancellous bone volume reduced, while in others no significant changes in bone occur. In June of 1996 Drs. T. Wronski, S. Miller and myself participated in a flight experiment (STS 78) to examine the effects of glucocorticoids on bone during weightlessness. Technically the 17 day flight experiment was flawless. The results, however, were surprising. Cancellous bone volume and osteoblast surface in the proximal tibial metaphysis were the same in flight and ground-based control rats. Normal levels of cancellous bone mass and bone formation were also detected in the lumbar vertebrae and femoral neck of flight rats. Furthermore, periosteal bone formation rate was found to be identical in flight and ground-based control rats. Spaceflight had little or no effect on bone metabolism! These results prompted us to carefully review the changes in bone observed in, and the flight conditions of previous spaceflight missions.

  4. Increased serum cartilage oligomeric matrix protein levels and decreased patellar bone mineral density in patients with chondromalacia patellae.

    Science.gov (United States)

    Murphy, E; FitzGerald, O; Saxne, T; Bresnihan, B

    2002-11-01

    Chondromalacia patellae is a potentially disabling disorder characterised by features of patellar cartilage degradation. To evaluate markers of cartilage and bone turnover in patients with chondromalacia patellae. 18 patients with chondromalacia patellae were studied. Serum cartilage oligomeric matrix protein (s-COMP) and bone sialoprotein (s-BSP) levels were measured by enzyme linked immunosorbent assay (ELISA) and compared with those of age and sex matched healthy control subjects. Periarticular bone mineral density (BMD) of both knee joints was assessed by dual energy x ray absorptiometry (DXA). s-COMP levels were significantly raised in all patients with chondromalacia patellae compared with healthy control subjects (p=0.0001). s-BSP levels did not differ significantly between the groups (p=0.41). BMD of the patella was significantly reduced in patients with chondromalacia patellae compared with the control subjects (p=0.016). In patients with bilateral chondromalacia patellae, BMD of the patella was lower in the more symptomatic knee joint (p=0.005). Changes in periarticular BMD were localised to the patella and were not present in femoral regions. Neither s-COMP (p=0.18) nor s-BSP (p=0.40) levels correlated with patellar BMD. Increased s-COMP levels, reflecting cartilage degradation, and reduced BMD localised to the patella may represent clinically useful markers in the diagnosis and monitoring of patients with chondromalacia patellae. Measures of cartilage degradation did not correlate with loss of patellar bone density, suggesting dissociated pathophysiological mechanisms.

  5. Administration of soluble activin receptor 2B increases bone and muscle mass in a mouse model of osteogenesis imperfecta

    Science.gov (United States)

    DiGirolamo, Douglas J.; Singhal, Vandana; Chang, Xiaoli; Lee, Se-Jin; Germain-Lee, Emily L.

    2015-01-01

    Osteogenesis imperfecta (OI) comprises a group of heritable connective tissue disorders generally defined by recurrent fractures, low bone mass, short stature and skeletal fragility. Beyond the skeletal complications of OI, many patients also report intolerance to physical activity, fatigue and muscle weakness. Indeed, recent studies have demonstrated that skeletal muscle is also negatively affected by OI, both directly and indirectly. Given the well-established interdependence of bone and skeletal muscle in both physiology and pathophysiology and the observations of skeletal muscle pathology in patients with OI, we investigated the therapeutic potential of simultaneous anabolic targeting of both bone and skeletal muscle using a soluble activin receptor 2B (ACVR2B) in a mouse model of type III OI (oim). Treatment of 12-week-old oim mice with ACVR2B for 4 weeks resulted in significant increases in both bone and muscle that were similar to those observed in healthy, wild-type littermates. This proof of concept study provides encouraging evidence for a holistic approach to treating the deleterious consequences of OI in the musculoskeletal system. PMID:26161291

  6. A new strategy to simultaneous increase in the strength and ductility of AA2024 alloy via accumulative roll bonding (ARB)

    Energy Technology Data Exchange (ETDEWEB)

    Naseri, M.; Reihanian, M. [Department of Materials Science and Engineering, Faculty of Engineering, Shahid Chamran University of Ahvaz, Ahvaz (Iran, Islamic Republic of); Borhani, E., E-mail: e.borhani@semnan.ac.ir [Department of Nano Technology, Nano Materials Group, Semnan University, Semnan (Iran, Islamic Republic of)

    2016-02-22

    Nano/ultrafine grained (NG/UFG) AA2024 alloy produced by accumulative roll bonding (ARB) showed high strength (420 MPa) and very limited elongation (about 1.3%). A new strategy via ARB was developed to improve elongation (about 10%) of AA2024 alloy with a relatively high strength (365 MPa). The present strategy produced a bimodal structure consisting of coarse and ultrafine elongated grains in comparison to the UFG alloy. Electron backscattered diffraction (EBSD) revealed that after 4 ARB cycles, the fraction of high angle grain boundaries and mean misorientation angle of the boundaries in the bimodal grain structure were 61% and 27.34°, respectively, in comparison to that of annealed (54% and 24.96°) and UFG (79% and 34.27°) alloy. The crystallographic texture results indicated that, unlike the annealed AA2024 alloy, the intensity of Brass {011}<211> and S {123}<634> components remarkably increased in the UFG and bimodal alloy. Scanning electron microscopy (SEM) observations demonstrated that failure mode in bimodal alloy was ductile fracture with a combination of deep and shallow dimples.

  7. Resistance training is accompanied by increases in hip strength and changes in lower extremity biomechanics during running.

    Science.gov (United States)

    Snyder, Kelli R; Earl, Jennifer E; O'Connor, Kristian M; Ebersole, Kyle T

    2009-01-01

    Movement and muscle activity of the hip have been shown to affect movement of the lower extremity, and been related to injury. The purpose of this study was to determine if increased hip strength affects lower extremity mechanics during running. Within subject, repeated measures design. Fifteen healthy women volunteered. Hip abduction and external rotation strength were measured using a hand-held dynamometer. Three-dimensional biomechanical data of the lower extremity were collected during running using a high-speed motion capture system. Measurements were made before, at the mid-point, and after a 6-week strengthening program using closed-chain hip rotation exercises. Joint range of motion (rearfoot eversion, knee abduction, hip adduction, and internal rotation), eversion velocity, eversion angle at heel strike, and peak joint moments (rearfoot inversion, knee abduction, hip abduction, and external rotation) were analyzed using repeated measures analysis of variance (P knee abduction moment (P=0.05) decreased by 57% and 10%, respectively. The hip abductors and external rotators were strengthened, leading to an alteration of lower extremity joint loading which may reduce injury risk. These exercises could be used in the rehabilitation, or prevention, of lower extremity injuries.

  8. Increased periodontal bone loss in temporarily B lymphocyte-deficient rats

    DEFF Research Database (Denmark)

    Klausen, B; Hougen, H P; Fiehn, N E

    1989-01-01

    In order to study the role of T lymphocytes and B lymphocytes in the development of marginal periodontitis, experiments were performed on specific-pathogen-free (SPF) rats with various immunologic profiles. The study comprised nude (congenitally T lymphocyte-deficient), thymus-grafted nude (T-lym......-lymphocyte deficiency did not interfere with the development of periodontal disease in this model, whereas a temporary and moderate reduction in B-lymphocyte numbers seemed to predispose for aggravation of periodontal bone loss.......In order to study the role of T lymphocytes and B lymphocytes in the development of marginal periodontitis, experiments were performed on specific-pathogen-free (SPF) rats with various immunologic profiles. The study comprised nude (congenitally T lymphocyte-deficient), thymus-grafted nude (T...... had significantly less periodontal bone support than controls. Anti-mu treated inoculated rats had significantly less periodontal bone support than nude and normal rats, whereas no difference was found between normal, nude, and thymus-grafted rats. It is concluded that permanent T...

  9. Increased bone mineral density in postmenopausal women with type 2 diabetes mellitus

    International Nuclear Information System (INIS)

    Hadzibegovic, I.; Miskic, B.; Prvulovic, D.; Bistrovic, D.; Cosic, V.

    2008-01-01

    Studies of bone mineral density (BMD) in women with type 2 diabetes mellitus have shown conflicting results. We conducted this study to determine whether postmenopausal women with diabetes have higher BMD than non-diabetic women of similar age and to investigate the relationship between BMD and relevant clinical characteristics in these groups of women. We retrospectively analyzed lumbar spine, femoral neck and radius BMD data and other relevant clinical data for 130 postmenopausal women with type 2 diabetes mellitus and 166 non-diabetic women collected during a voluntary screening for osteoporosis in postmenopausal women without a history of low bone mass or osteoporotic fractures. Women with type 2 diabetes mellitus had significantly higher mean lumbar spine BMD (0.903 +-0.165 vs. 0.824+-0.199, respectively, P<0.001) and mean femoral neck BMD (0.870+-0.132 vs. 0.832+-0.134, respectively, P<0.05) than non-diabetic women. In both groups of women, age correlated negatively with BMD levels at all three anatomical sites. Higher body mass index was associated only with higher lumber spine BMD in both groups. Alkaline phosphatase levels showed a negative correlation with BMD at all sites in women with type 2 diabetes mellitus. Postmenopausal women with type 2 diabetes mellitus have higher BMD levels than non-diabetic women with similar clinical characteristics and require a more scrutinized approach in managing low bone mass. (author)

  10. Anorexia Nervosa, Obesity and Bone Metabolism

    Science.gov (United States)

    Misra, Madhusmita; Klibanski, Anne

    2014-01-01

    Anorexia nervosa and obesity are conditions at the extreme ends of the nutritional spectrum, associated with marked reductions versus increases respectively in body fat content. Both conditions are also associated with an increased risk for fractures. In anorexia nervosa, body composition and hormones secreted or regulated by body fat content are important determinants of low bone density, impaired bone structure and reduced bone strength. In addition, anorexia nervosa is characterized by increases in marrow adiposity and decreases in cold activated brown adipose tissue, both of which are related to low bone density. In obese individuals, greater visceral adiposity is associated with greater marrow fat, lower bone density and impaired bone structure. In this review, we discuss bone metabolism in anorexia nervosa and obesity in relation to adipose tissue distribution and hormones secreted or regulated by body fat content. PMID:24079076

  11. The effect of supplementation of calcium, vitamin D, boron, and increased fluoride intake on bone mechanical properties and metabolic hormones in rat.

    Science.gov (United States)

    Ghanizadeh, G; Babaei, M; Naghii, Mohammad Reza; Mofid, M; Torkaman, G; Hedayati, M

    2014-04-01

    Evidence indicates that optimal nutrition plays a role in bone formation and maintenance. Besides major components of mineralization such as calcium, phosphorus, and vitamin D, other nutrients like boron and fluoride have beneficial role, too. In this study, 34 male Wistar rats were divided into five groups: control diet, fluoride, fluoride + boron, fluoride + calcium + vitamin D, and fluoride + boron + calcium + vitamin D. Boron equal to 1.23 mg, calcium and vitamin D equal to 210 mg + 55 IU and fluoride equal to 0.7 mg/rat/day was added to their drinking water for 8 weeks. Plasma blood samples and bones were collected. Findings are evidence that fluoride + boron intake revealed significant positive effects on bone mechanical properties and bone metabolic hormones. These findings suggest that combined intake of these two elements has beneficial effects on bone stiffness and breaking strength comparing to even calcium + vitamin D supplementation. This evidence dealing with health problems related to bone and skeletal system in humans should justify further investigation of the role of boron and fluoride with other elements in relation to bone.

  12. Polyether ether ketone implants achieve increased bone fusion when coated with nano-sized hydroxyapatite

    DEFF Research Database (Denmark)

    Johansson, Pär; Jimbo, Ryo; Naito, Yoshihito

    2016-01-01

    Polyether ether ketone (PEEK) possesses excellent mechanical properties similar to those of human bone and is considered the best alternative material other than titanium for orthopedic spine and trauma implants. However, the deficient osteogenic properties and the bioinertness of PEEK limit its...... fields of application. The aim of this study was to limit these drawbacks by coating the surface of PEEK with nano-scaled hydroxyapatite (HA) minerals. In the study, the biological response to PEEK, with and without HA coating, was investigated. Twenty-four screw-like and apically perforated implants...

  13. Role of TAF12 in the Increased VDR Activity in Paget’s Disease of Bone

    Science.gov (United States)

    2014-10-01

    Oncology, School of Medicine, Indiana University, 980 West Walnut Street, R3, Indianapolis, IN 46202, USA. E ‐mail: groodman@iu.edu ORIGINAL ARTICLE JBMR...and B. Data are expressed as the mean SD (n¼ 25); p< 0.01, significantly different from OCLs formedwith the same treatment inWTmouse cultures. ( E ...Interleukin 6. A potential autocrine/paracrine factor in Paget’s disease of bone. J Clin Invest. 1992;89:46–52. 5. Hoyland JA, Freemont AJ, Sharpe PT

  14. Tibial loading increases osteogenic gene expression and cortical bone volume in mature and middle-aged mice.

    Directory of Open Access Journals (Sweden)

    Matthew J Silva

    Full Text Available There are conflicting data on whether age reduces the response of the skeleton to mechanical stimuli. We examined this question in female BALB/c mice of different ages, ranging from young to middle-aged (2, 4, 7, 12 months. We first assessed markers of bone turnover in control (non-loaded mice. Serum osteocalcin and CTX declined significantly from 2 to 4 months (p<0.001. There were similar age-related declines in tibial mRNA expression of osteoblast- and osteoclast-related genes, most notably in late osteoblast/matrix genes. For example, Col1a1 expression declined 90% from 2 to 7 months (p<0.001. We then assessed tibial responses to mechanical loading using age-specific forces to produce similar peak strains (-1300 µε endocortical; -2350 µε periosteal. Axial tibial compression was applied to the right leg for 60 cycles/day on alternate days for 1 or 6 weeks. qPCR after 1 week revealed no effect of loading in young (2-month mice, but significant increases in osteoblast/matrix genes in older mice. For example, in 12-month old mice Col1a1 was increased 6-fold in loaded tibias vs. controls (p = 0.001. In vivo microCT after 6 weeks revealed that loaded tibias in each age group had greater cortical bone volume (BV than contralateral control tibias (p<0.05, due to relative periosteal expansion. The loading-induced increase in cortical BV was greatest in 4-month old mice (+13%; p<0.05 vs. other ages. In summary, non-loaded female BALB/c mice exhibit an age-related decline in measures related to bone formation. Yet when subjected to tibial compression, mice from 2-12 months have an increase in cortical bone volume. Older mice respond with an upregulation of osteoblast/matrix genes, which increase to levels comparable to young mice. We conclude that mechanical loading of the tibia is anabolic for cortical bone in young and middle-aged female BALB/c mice.

  15. Microfluidic enhancement of intramedullary pressure increases interstitial fluid flow and inhibits bone loss in hindlimb suspended mice.

    Science.gov (United States)

    Kwon, Ronald Y; Meays, Diana R; Tang, W Joyce; Frangos, John A

    2010-08-01

    Interstitial fluid flow (IFF) has been widely hypothesized to mediate skeletal adaptation to mechanical loading. Although a large body of in vitro evidence has demonstrated that fluid flow stimulates osteogenic and antiresorptive responses in bone cells, there is much less in vivo evidence that IFF mediates loading-induced skeletal adaptation. This is due in large part to the challenges associated with decoupling IFF from matrix strain. In this study we describe a novel microfluidic system for generating dynamic intramedullary pressure (ImP) and IFF within the femurs of alert mice. By quantifying fluorescence recovery after photobleaching (FRAP) within individual lacunae, we show that microfluidic generation of dynamic ImP significantly increases IFF within the lacunocanalicular system. In addition, we demonstrate that dynamic pressure loading of the intramedullary compartment for 3 minutes per day significantly eliminates losses in trabecular and cortical bone mineral density in hindlimb suspended mice, enhances trabecular and cortical structural integrity, and increases endosteal bone formation rate. Unlike previously developed modalities for enhancing IFF in vivo, this is the first model that allows direct and dynamic modulation of ImP and skeletal IFF within mice. Given the large number of genetic tools for manipulating the mouse genome, this model is expected to serve as a powerful investigative tool in elucidating the role of IFF in skeletal adaptation to mechanical loading and molecular mechanisms mediating this process.

  16. [Bone Cell Biology Assessed by Microscopic Approach. The effects of active vitamin D3 such as alfacalcidol and eldecalcitol on bone quality].

    Science.gov (United States)

    Saito, Mitsuru; Marumo, Keishi

    2015-10-01

    Active vitamin D3 is used for the treatment for osteoporosis in Japan. Recently, data have accumulated that collagen cross-link formation in bone affect bone strength. In fact, impaired enzymatic cross-linking, over-hydroxylation of crosslinks, and an increase in non-enzymatic crosslinking advanced glycation end products (AGEs) such as pentosidine, in bone collagen have been proposed as a major cause of bone fragility in osteoporosis. We reported that alfacalcidol and eldecalcitol improves bone material properties such as collagen cross-link formation, microarchitecture, and microcrack resulting in the increase of bone strength (Saito M, Bone 2010;46:1170-1179, Calcif Tissue Int 2011;88:314-324, Bone, 2015;73:8-15). In this review, we described how active vitamin D3 improve bone collagen cross-link formation and mineral qualities.

  17. Niacin deficiency delays DNA excision repair and increases spontaneous and nitrosourea-induced chromosomal instability in rat bone marrow.

    Science.gov (United States)

    Kostecki, Lisa M; Thomas, Megan; Linford, Geordie; Lizotte, Matthew; Toxopeus, Lori; Bartleman, Anne-Pascale; Kirkland, James B

    2007-12-01

    We have shown that niacin deficiency impairs poly(ADP-ribose) formation and enhances sister chromatid exchanges and micronuclei formation in rat bone marrow. We designed the current study to investigate the effects of niacin deficiency on the kinetics of DNA repair following ethylation, and the accumulation of double strand breaks, micronuclei (MN) and chromosomal aberrations (CA). Weanling male Long-Evans rats were fed niacin deficient (ND), or pair fed (PF) control diets for 3 weeks. We examined repair kinetics by comet assay in the 36h following a single dose of ethylnitrosourea (ENU) (30mg/kg bw). There was no effect of ND on mean tail moment (MTM) before ENU treatment, or on the development of strand breaks between 0 and 8h after ENU. Repair kinetics between 12 and 30h were significantly delayed by ND, with a doubling of area under the MTM curve during this period. O(6)-ethylation of guanine peaked by 1.5h, was largely repaired by 15h, and was also delayed in bone marrow cells from ND rats. ND significantly enhanced double strand break accumulation at 24h after ENU. ND alone increased chromosome and chromatid breaks (four- and two-fold). ND alone caused a large increase in MN, and this was amplified by ENU treatment. While repair kinetics suggest that ND may be acting by creating catalytically inactive PARP molecules with a dominant-negative effect on repair processes, the effect of ND alone on O(6)-ethylation, MN and CA, in the absence of altered comet results, suggests additional mechanisms are also leading to chromosomal instability. These data support the idea that the bone marrow cells of niacin deficient cancer patients may be more sensitive to the side effects of genotoxic chemotherapy, resulting in acute bone marrow suppression and chronic development of secondary leukemias.

  18. Inter-rater reliability of assessment of levator ani muscle strength and attachment to the pubic bone in nulliparous women.

    Science.gov (United States)

    van Delft, K; Schwertner-Tiepelmann, N; Thakar, R; Sultan, A H

    2013-09-01

    The modified Oxford scale (MOS) has been found previously to have poor inter-rater reliability, whereas digital assessment of levator ani muscle (LAM) attachment to the pubic bone has been shown to have acceptable reliability. Our aim was to evaluate inter-rater reliability of the validated MOS and to develop a reliable classification system for digital assessment of LAM attachment, correlating this to findings on transperineal ultrasound (TPUS) examination. Evaluation of the MOS by palpation was performed in nulliparous women by two investigators. LAM attachment was evaluated using digital palpation, for which a novel classification system was developed with four grades based on the position of the attachment and presence of discernible muscle. Findings were compared with those on TPUS examination. Inter-rater reliability was assessed using Cohen's kappa statistic. Twenty-five nulliparous women were examined. There was agreement in MOS scores between the investigators in 64% of women (n = 16), with a kappa of 0.66 (indicating substantial agreement). There was agreement in palpation of LAM attachment using the new grading system in 96% of women (n = 24), with a kappa of 0.90 (indicating almost perfect agreement). TPUS examination did not show LAM avulsion in any woman, with the exception of one with a partial avulsion. In this group of nulliparous patients, there was substantial agreement between the two investigators in evaluation of the MOS and there was good agreement between grades of LAM attachment using the new classification system, which correlated with findings on TPUS examination. It therefore appears that these results are reproducible in nulliparous women and the techniques can be readily learned and reliably incorporated into clinical practice and research after appropriate training. Further research is required to establish clinical utility of the grading system for LAM attachment in postpartum women and in women with symptomatic pelvic organ

  19. Osteogenic protein-1 increases the fixation of implants grafted with morcellised bone allograft and ProOsteon bone substitute: an experimental study in dogs

    DEFF Research Database (Denmark)

    Jensen, T B; Overgaard, S; Lind, M

    2007-01-01

    Impacted bone allograft is often used in revision joint replacement. Hydroxyapatite granules have been suggested as a substitute or to enhance morcellised bone allograft. We hypothesised that adding osteogenic protein-1 to a composite of bone allograft and non-resorbable hydroxyapatite granules...... (ProOsteon) would improve the incorporation of bone and implant fixation. We also compared the response to using ProOsteon alone against bone allograft used in isolation. We implanted two non-weight-bearing hydroxyapatite-coated implants into each proximal humerus of six dogs, with each implant...... surrounded by a concentric 3 mm gap. These gaps were randomly allocated to four different procedures in each dog: 1) bone allograft used on its own; 2) ProOsteon used on its own; 3) allograft and ProOsteon used together; or 4) allograft and ProOsteon with the addition of osteogenic protein-1. After three...

  20. In long-term bedridden elderly patients with dietary copper deficiency, biochemical markers of bone resorption are increased with copper supplementation during 12 weeks.

    Science.gov (United States)

    Kawada, Etsuo; Moridaira, Kazuaki; Itoh, Katsuhiko; Hoshino, Ayami; Tamura, Jun'ichi; Morita, Toyoho

    2006-01-01

    Although the effect of copper on bone has been tested in animals and healthy subjects, no studies concerning the effect of copper supplementation on bone metabolism in patients with copper deficiency have been reported because of the rarity of these patients. This study was conducted to investigate the effect of copper supplementation on bone metabolism in copper-deficient patients. This study included 10 patients (83.7 +/- 8.3 years) with dietary copper deficiency under long-term bed rest for more than 12 months. They had their diets supplemented with copper sulfate (3 mg/day) over 12 weeks in addition to their diet of only one kind of enteral food with a low concentration of copper. Serum copper and ceruloplasmin, urinary deoxypyridinoline (DPD) and collagen-type 1 N-telopeptide (NTX) (biomarkers of bone resorption), serum osteocalcin (OC) and bone-specific alkaline phosphatase (Bone ALP) (biomarkers of bone formation) were analyzed at baseline, 4 and 12 weeks after copper supplementation. DPD and NTX excretion were significantly increased 4 weeks after copper supplementation (p = 0.009 and p = 0.013, respectively). Serum bone ALP and OC were not significantly changed 12 weeks after copper supplementation (p = 0.051 and p = 0.594). In patients with nutritional copper deficiency, bone resorption markers are increased with copper supplementation. Copyright (c) 2006 S. Karger AG, Basel.

  1. A 3-year physical activity intervention program increases the gain in bone mineral and bone width in prepubertal girls but not boys: the prospective copenhagen school child interventions study (CoSCIS).

    Science.gov (United States)

    Hasselstrøm, H A; Karlsson, M K; Hansen, S E; Grønfeldt, V; Froberg, K; Andersen, L B

    2008-10-01

    The aim of this study was to evaluate the effect of increasing the amount of time spent in physical education classes on bone mineral accrual and gain in bone size in prepubertal Danish children. A total of 135 boys and 108 girls, aged 6-8 years, were included in a school-based curriculum intervention program where the usual time spent in physical education classes was doubled to four classes (180 min) per week. The control group comprised age-matched children (62 boys and 76 girls) recruited from a separate community who completed the usual Danish school curriculum of physical activity (90 min/week). Dual-energy X-ray absorptiometry was used to evaluate bone mineral content (BMC; g), bone mineral density (g/cm(2)), and bone width at the calcaneus and distal forearm before and after 3 years of intervention. Anthropometrics and Tanner stages were evaluated on the same occasions. General physical activity was measured with an accelerometer worn for 4 days. In girls, the intervention group had a 12.5% increase (P = 0.04) in distal forearm BMC and a 13.2% increase (P = 0.005) in distal forearm scanned area compared with girls in the control group. No differences were found between the intervention and control groups in boys. Increasing the frequency of physical education classes for prepubertal children is associated with a higher accrual of bone mineral and higher gain in bone size after 3 years in girls but not in boys.

  2. Texture analysis of trabecular bone using conventional radiographs: medical imaging and osteoporosis

    International Nuclear Information System (INIS)

    Karunanithi, R.; Panicker, T.M.R.; Paul Korath, M.; Jagadeesan, K.; Ganesan, S.

    2008-01-01

    Osteoporosis is characterized by reduced bone mass, microstructural deterioration with advancing age, and an increase in fracture risk. The accurate clinical assessment of bone strength and fracture risk is important for management of bone loss diseases such as osteoporosis risk. From a clinical point of view, microarchitecture is an interesting aspect to study and define patterns of bone alterations with aging and pathology. Microarchitecture seems to be a determinant of bone fragility independent of bone density. Moreover, bone microarchitecture seems to be important to understand the mechanisms of bone fragility independent of bone density. Moreover bone microarchitecture seems to be important to understand the mechanisms of bone fragility as well as the action of the drugs used to prevent osteoporotic fractures. In the case of osteoporosis the bone texture of the trabecular network as it appears on the plain radiographs can be quantified by applying image processing tools. Among the factors conditioning bone strength and osteoporotic fractures, bone mineral density is the most important and the best studied. Though, other factors also play a role: macroarchitecture of bones, cortical thickness, quality of bone crystal and of collagen network and trabecular microarchitecture. The microarchitecture plays a major role, and is an aspect of the definition of osteoporosis. Therefore, it would be very helpful if these alterations could be measured in addition to bone mineral density with noninvasive techniques, such as radiographs, and to assess the status of the bone by texture analysis

  3. Growth hormone (GH) treatment increases serum insulin-like growth factor binding protein-3, bone isoenzyme alkaline phosphatase and forearm bone mineral content in young adults with GH deficiency of childhood onset

    DEFF Research Database (Denmark)

    Juul, A; Pedersen, S A; Sørensen, S

    1994-01-01

    Recent studies have demonstrated that growth hormone (GH)-deficient adults have a markedly decreased bone mineral content compared to healthy adults. However, there are conflicting results regarding the effects of GH treatment on bone mineral content in GH-deficient adults. Therefore, we evaluated...... the effect of GH treatment on a marker of bone formation (bone alkaline phosphatase), hepatic excretory function and distal forearm bone mineral content in GH-deficient adults. Growth hormone was administered subcutaneously in 21 adults (13 males and 8 females) with GH deficiency of childhood onset for 4...... months in a double-blind, placebo-controlled GH trial, while 13 of the patients then received further GH for an additional 14 months. Serum insulin-like growth factor I (IGF-I) increased significantly from 100 to 279 micrograms/l and IGF binding protein-3 (IGFBP-3) from 1930 to 3355 micrograms/l after 4...

  4. Fibromodulin reduces scar size and increases scar tensile strength in normal and excessive-mechanical-loading porcine cutaneous wounds.

    Science.gov (United States)

    Jiang, Wenlu; Ting, Kang; Lee, Soonchul; Zara, Janette N; Song, Richard; Li, Chenshuang; Chen, Eric; Zhang, Xinli; Zhao, Zhihe; Soo, Chia; Zheng, Zhong

    2018-04-01

    Hypertrophic scarring is a major postoperative complication which leads to severe disfigurement and dysfunction in patients and usually requires multiple surgical revisions due to its high recurrence rates. Excessive-mechanical-loading across wounds is an important initiator of hypertrophic scarring formation. In this study, we demonstrate that intradermal administration of a single extracellular matrix (ECM) molecule-fibromodulin (FMOD) protein-can significantly reduce scar size, increase tensile strength, and improve dermal collagen architecture organization in the normal and even excessive-mechanical-loading red Duroc pig wound models. Since pig skin is recognized by the Food and Drug Administration as the closest animal equivalent to human skin, and because red Duroc pigs show scarring that closely resembles human proliferative scarring and hypertrophic scarring, FMOD-based technologies hold high translational potential and applicability to human patients suffering from scarring-especially hypertrophic scarring. © 2018 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

  5. New And Existing Bridge Constructions - Increase of Fatigue Strength of Welded Joints by High Frequency Mechanical Impact Treatment

    Directory of Open Access Journals (Sweden)

    Ummenhofer Thomas

    2013-07-01

    Full Text Available Numerous studies at KIT prove that high frequency mechanical impact (HFMI treatment is an efficient method for increasing the fatigue strength of welded steel structures. Within different research projects it was found that HFMI-methods can be used successfully for new and existing structures in order to extend the fatigue life. This paper gives an overview of the current status of existing steel bridges in Germany regarding aspects like bridge age distributions and traffic loads. Based on that overview welded joints susceptible to fatigue failure are identified. Using component-like small scale specimens, HFMI-methods were investigated within the objective of implementing an effective application for new and existing structures. Applying the fatigue test data observed, existing design proposals are evaluated and design recommendations for HFMI-treated joints are given. As a result of the research work, a transfer into practice has been realized and different applications are illustrated using the example of bridge constructions made of steel.

  6. Increased functional connectivity strength of right inferior temporal gyrus in first-episode, drug-naive somatization disorder.

    Science.gov (United States)

    Su, Qinji; Yao, Dapeng; Jiang, Muliang; Liu, Feng; Jiang, Jiajing; Xu, Chunxing; Dai, Yi; Yu, Miaoyu; Long, Liling; Li, Hongzheng; Liu, Jianrong; Zhang, Zhikun; Zhang, Jian; Xiao, Changqing; Guo, Wenbin

    2015-01-01

    Evidence of brain structural and functional alterations have been implicated in patients with somatization disorder (SD). However, little is known about brain functional connectivity in SD. In the present study, resting-state functional magnetic resonance imaging (fMRI) and graph theory were used to obtain a comprehensive view of whole-brain functional connectivity and to investigate the changes of voxel-wise functional networks in patients with SD. Twenty-five first-episode, medication-naive patients with SD and 28 age-, sex- and education-matched healthy controls (HCs) underwent resting-state fMRI. The graph theory approach was employed to analyze the data. Compared to the HCs, patients with SD showed significantly increased functional connectivity strength in the right inferior temporal gyrus (ITG). There is a significant positive correlation between the z-values of the cluster in the right ITG and Hamilton Anxiety Scale scores. Our findings indicate that there is a disruption of the functional connectivity pattern in the right ITG in first-episode, treatment-naive patients with SD, which bears clinical significance. © The Royal Australian and New Zealand College of Psychiatrists 2014.

  7. Bone Tissue Collagen Maturity and Mineral Content Increase With Sustained Hyperglycemia in the KK-Ay Murine Model of Type 2 Diabetes.

    Science.gov (United States)

    Hunt, Heather B; Pearl, Jared C; Diaz, David R; King, Karen B; Donnelly, Eve

    2018-05-01

    Type 2 diabetes mellitus (T2DM) increases fracture risk for a given bone mineral density (BMD), which suggests that T2DM changes bone tissue properties independently of bone mass. In this study, we assessed the effects of hyperglycemia on bone tissue compositional properties, enzymatic collagen crosslinks, and advanced glycation end-products (AGEs) in the KK-Ay murine model of T2DM using Fourier transform infrared (FTIR) imaging and high-performance liquid chromatography (HPLC). Compared to KK-aa littermate controls (n = 8), proximal femoral bone tissue of KK-Ay mice (n = 14) exhibited increased collagen maturity, increased mineral content, and less heterogeneous mineral properties. AGE accumulation assessed by the concentration of pentosidine, as well as the concentrations of the nonenzymatic crosslinks hydroxylysylpyridinoline (HP) and lysyl pyridinoline (LP), did not differ in the proximal femurs of KK-Ay mice compared to controls. The observed differences in tissue-level compositional properties in the KK-Ay mice are consistent with bone that is older and echo observations of reduced remodeling in T2DM. © 2017 American Society for Bone and Mineral Research. © 2017 American Society for Bone and Mineral Research.

  8. Increased mortality by septicemia, interstitial pneumonitis and pulmonary fibrosis among bone marrow transplant recipients receiving an increased mean dose rate of total irradiation

    International Nuclear Information System (INIS)

    Ringden, O.; Baaryd, I.; Johansson, B.

    1983-01-01

    Seven bone marrow transplant recipients with acute lymphoblastic leukemia receiving a mean dose rate of 0.07 Gy/min of total body irradiation towards the pelvic midpoint and the lungs had an increased (p<0.01) overall death rate of 86 per cent compared with 33 per cent among 27 patients with acute non-lymphoblastic leukemia or acute lymphoblastic leukemia treated with a mean dose rate of 0.04 Gy/min. Among the patients receiving the higher dose rate there was an increased mortality in causes related to radiation toxicity like early septicemia, interstitial pneumonitis and pulmonary fibrosis, compared with all patients receiving the lower dose rate (p<0.01) and also with 10 patients from this group with acute lymphoblastic leukemia (p<0.02). (Auth.)

  9. Comparative Analysis of Effect of Density, Insertion Angle and Reinsertion on Pull-Out Strength of Single and Two Pedicle Screw Constructs Using Synthetic Bone Model

    OpenAIRE

    Krishnan, Venkatesh; Varghese, Vicky; Kumar, Gurunathan Saravana

    2016-01-01

    Study Design Biomechanical study. Purpose To determine the effect of density, insertion angle and reinsertion on pull-out strength of pedicle screw in single and two screw-rod configurations. Overview of Literature Pedicle screw pull-out studies have involved single screw construct, whereas two screws and rod constructs are always used in spine fusions. Extrapolation of results using the single screw construct may lead to using expensive implants or increasing the fusion levels specifically i...

  10. 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.

  11. Increased bone mineral density in Aboriginal and Torres Strait Islander Australians: impact of body composition differences.

    Science.gov (United States)

    Maple-Brown, L J; Hughes, J; Piers, L S; Ward, L C; Meerkin, J; Eisman, J A; Center, J R; Pocock, N A; Jerums, G; O'Dea, K

    2012-07-01

    Bone mineral density (BMD) has been reported to be both higher and lower in Indigenous women from different populations. Body composition data have been reported for Indigenous Australians, but there are few published BMD data in this population. We assessed BMD in 161 Indigenous Australians, identified as Aboriginal (n=70), Torres Strait Islander (n=68) or both (n=23). BMD measurements were made on Norland-XR46 (n=107) and Hologic (n=90) dual-energy X-ray absorptiometry (DXA) machines. Norland BMD and body composition measurements in these individuals, and also in 36 Caucasian Australians, were converted to equivalent Hologic BMD (BMD(H)) and body composition measurements for comparison. Femoral neck (FN) and lumbar spine Z-scores were high in Indigenous participants (mean FN Z-score: Indigenous men +0.98, pAboriginal and/or Torres Strait Islander than Caucasian participants, after adjusting for age, gender, diabetes and height and remained higher in men after addition of lean mass to the model. We conclude that FN BMD is higher in Aboriginal and/or Torres Strait Islander Australians than Caucasian Australian reference ranges and these differences still remained significant in men after adjustment for lean mass. It remains to be seen whether these BMD differences translate to differences in fracture rates. Copyright © 2012 Elsevier Inc. All rights reserved.

  12. Short Anabolic Peptides for Bone Growth.

    Science.gov (United States)

    Amso, Zaid; Cornish, Jillian; Brimble, Margaret A

    2016-07-01

    Loss of bone occurs in the age-related skeletal disorder, osteoporosis, leading to bone fragility and increased incidence of fractures, which are associated with enormous costs and substantial morbidity and mortality. Recent data indicate that osteoporotic fractures are more common than other diseases, which usually attract public attention (e.g., heart attack and breast cancer). The prevention and treatment of this skeletal disorder are therefore of paramount importance. Majority of osteoporosis medications restore skeletal balance by reducing osteoclastic activity, thereby reducing bone resorption. These agents, however, do not regenerate damaged bone tissue, leaving limited options for patients once bone loss has occurred. Recently, attention has turned to bone-anabolic agents. Such agents have the ability to increase bone mass and strength, potentially reversing structural damage. To date, only one bone-anabolic drug is available in the market. The discovery of more novel, cost-effective bone anabolic agents is therefore a priority to treat those suffering from this disabling condition. Short peptides offer an important alternative for the development of novel bone-anabolic agents given their high target binding specificity, which translates into potent activity with limited side effects. This review summarizes attempts in the identification of bone-anabolic peptides, and their development for promoting bone growth. © 2016 Wiley Periodicals, Inc.

  13. The effect of Platelet Lysate on osteoblast proliferation associated with a transient increase of the inflammatory response in bone regeneration.

    Science.gov (United States)

    Ruggiu, Alessandra; Ulivi, Valentina; Sanguineti, Francesca; Cancedda, Ranieri; Descalzi, Fiorella

    2013-12-01

    Platelet Lysate (PL) contains a cocktail of growth factors and cytokines, which actively participates in tissue repair and its clinical application has been broadly described. The aim of this study was to assess the regenerative potential of PL for bone repair. We demonstrated that PL stimulation induces a transient increase of the inflammatory response in quiescent human osteoblasts, via NF-kB activation, COX-2 induction, PGE2 production and secretion of pro-inflammatory cytokines. Furthermore, we showed that long-term PL stimulation enhances proliferation of actively replicating osteoblasts, without affecting their differentiation potential, along with changes of cell morphology, resulting in increased cell density at confluence. In confluent resting osteoblasts, PL treatment induced resumption of proliferation, change in cell morphology and increase of cell density at confluence. A burst of PL treatment (24-h) was sufficient to trigger such processes in both conditions. These results correlated with up-regulation of the proliferative and survival pathways ERKs and Akt and with cell cycle re-activation via induction of CyclinD1 and phosphorylation of Rb, following PL stimulation. Our findings demonstrate that PL treatment results in activation and expansion of resting osteoblasts, without affecting their differentiation potential. Therefore PL represents a good therapeutic candidate in regenerative medicine for bone repair. Copyright © 2013 Elsevier Ltd. All rights reserved.

  14. [Clinical usefulness of bone turnover markers in the management of osteoporosis].

    Science.gov (United States)

    Yano, Shozo

    2013-09-01

    Osteoporosis is a state of elevated risk for bone fracture due to depressed bone strength, which is considered to be the sum of bone mineral density and bone quality. Since a measure of bone quality has not been established, bone mineral density and bone turnover markers are the only way to evaluate bone strength. Bone turnover markers are classified into bone formation marker and resorption marker, which are correlated with the bone formation rate and resorption rate, respectively, and bone matrix-related marker. Bone is always metabolized; old tissue is resorbed by acids and proteases derived from osteoclasts, whereas new bone is produced by osteoblasts. Bone formation and resorption rates should be balanced (also called coupled). When the bone resorption rate exceeds the formation rate(uncoupled state), bone volume will be reduced. Thus, we can comprehend bone metabolism by measuring both formation and resorption markers at the same time. Increased fracture risk is recognized by elevated bone resorption markers and undercarboxylated osteocalcin, which reflects vitamin K insufficiency and bone turnover. These values and the time course give us helpful information to choose medicine suitable for the patients and to judge the responsiveness. If the value is extraordinarily high without renal failure, metabolic bone disorder or bone metastatic tumor should be considered. Bone quality may be assessed by measuring bone matrix-related markers such as homocystein and pentosidine. Since recent studies indicate that the bone is a hormone-producing organ, it is possible that glucose metabolism or an unknown mechanism could be assessed in the future.

  15. Bone turnover is altered in transgenic rats overexpressing the P2Y2 purinergic receptor

    DEFF Research Database (Denmark)

    Ellegaard, Maria; Agca, Cansu; Petersen, Solveig

    2017-01-01

    overexpression on bone status and bone cell function using a transgenic rat. Three-month-old female transgenic Sprague Dawley rats overexpressing P2Y2R (P2Y2R-Tg) showed higher bone strength of the femoral neck. Histomorphometry showed increase in resorptive surfaces and reduction in mineralizing surfaces. Both...

  16. Newly developed Ti-Nb-Zr-Ta-Si-Fe biomedical beta titanium alloys with increased strength and enhanced biocompatibility\

    Czech Academy of Sciences Publication Activity Database

    Kopová, Ivana; Stráský, J.; Harcuba, P.; Landa, Michal; Janeček, M.; Bačáková, Lucie

    2016-01-01

    Roč. 60, Mar 1 (2016), s. 230-238 ISSN 0928-4931 R&D Projects: GA ČR(CZ) GAP107/12/1025 Institutional support: RVO:67985823 ; RVO:61388998 Keywords : elastic modulus * alloy hardening * cell growth * osteogenic cell differentiation * bone implants Subject RIV: EI - Biotechnology ; Bionics; BI - Acoustics (UT-L) Impact factor: 4.164, year: 2016

  17. The healing of fractured bones

    Energy Technology Data Exchange (ETDEWEB)

    Bacon, G E [Central Electricity Generating Board, Cheltenham (United Kingdom)

    1997-04-01

    A method utilising neutron beams of width 1 mm, used on D1B (2.4 A) and D20 (1.3 A) to study the healing of fractured bones is presented. It is found that the callus bone uniting the fractured tibia of a sheep, whose healing had been encouraged by daily mechanical vibration over a period of three months, showed no trace of the large preferential vertical orientation of the apatite crystals which is characteristic of the normal bone. Nevertheless the bone had regained about 60% of its mechanical strength and the callus bone, although not oriented, was well crystallized. It is considered that the new monochromator for D20, expected to give increased intensity at 2.5 A, will be of considerable advantage. (author). 2 refs.

  18. Sequential treatment with basic fibroblast growth factor and parathyroid hormone restores lost cancellous bone mass and strength in the proximal tibia of aged ovariectomized rats

    DEFF Research Database (Denmark)

    Wronski, T.J.; Ratkus, A.M.; Thomsen, Jesper Skovhus

    2001-01-01

    This study was designed to determine whether sequential treatment with basic fibroblast growth factor (bFGF) and parathyroid hormone (PTH) can restore lost cancellous bone mass and strength at a severely osteopenic skeletal site in aged ovariectomized (OVX) rats. Female Sprague-Dawley rats were...... intravenously (iv) daily with bFGF for 14 days at a dose of 200 microg/kg body weight. At the end of bFGF treatment, one group was killed whereas the other group was subjected to 8 weeks of treatment with synthetic human PTH 1-34 [hPTH(1-34)] consisting of subcutaneous (sc) injections 5 days/week at a dose...... of 80 microg/kg. Another group of OVX rats was treated iv with vehicle for 2 weeks followed by treatment with PTH alone for 8 weeks. Other groups of sham-operated control rats and OVX rats were treated iv and sc with vehicle alone. The right proximal tibia from each rat was processed undecalcified...

  19. Bariatric Roux-En-Y Gastric Bypass Surgery: Adipocyte Proteins Involved in Increased Bone Remodeling in Humans.

    Science.gov (United States)

    Biagioni, Maria Fernanda G; Mendes, Adriana L; Nogueira, Célia Regina; Leite, Celso V; Gollino, Loraine; Mazeto, Gláucia Mfs

    2017-07-01

    Bariatric surgery has been associated with bone remodeling changes. The action of adipokines on the expression of receptor activator of nuclear factor kappa β ligand (RANKL) and osteoprotegerin (OPG) and on an increase in sclerostin could be related to these changes. This study aimed to assess the repercussions of weight loss, fat mass (FM), and fat-free mass (FFM) loss and biochemical and hormonal changes on bone remodeling markers after Roux-en-Y gastric bypass (RYGB). Anthropometric data, parathyroid hormone (PTH), bone-specific alkaline phosphatase (BSAP), collagen type 1 C-telopeptide (CTX), 25-hydroxy vitamin D (25-OH-VitD), leptin, adiponectin, RANKL, OPG, and sclerostin of 30 menstruating women were measured preoperatively (Pre), and 3, 12, and 24 months (m) after RYGB. Leptin (34.4 (14.7; 51.9) vs. 22.5 (1.9; 52.7) ng/mL) and OPG (3.6 (1.1; 11.5) vs. 3.4 (1.5; 6) pmol/L) decreased, and adiponectin (7.4 (1.7; 18.4) vs. 13.8 (3.0; 34.6) μg/mL), CTX (0.2 (0.1; 2.2) vs. 0.6 (0.4; 6.0) ng/mL), RANKL (0.1 (0.0; 0.5) vs. 0.3 (0.0; 2.0) pmol/L), and sclerostin (21.7 (3.2; 75.1) vs. 34.8 (6.4; 80.5) pmol/L) increased after 3 m. BSAP increased after 12 m (10.1 (5.4; 18.9) vs. 13.9 (6.9; 30.2) μg/mL) (p < 0.005). CTX correlated positively with adiponectin at 24 m and inversely with leptin Pre; OPG at 3 m; weight, FM, FFM, and leptin at 24 m. RANKL correlated directly with weight at 3 m. Sclerostin correlated inversely with weight Pre and FM at 3 m. BSAP correlated negatively with 25-OH-VitD at 12 m, and positively with PTH at 24 m. RYGB induced weight loss, and biochemical, hormonal, and body composition changes are associated with higher bone remodeling.

  20. Key role of the expression of bone morphogenetic proteins in increasing the osteogenic activity of osteoblast-like cells exposed to shock waves and seeded on bioactive glass-ceramic scaffolds for bone tissue engineering.

    Science.gov (United States)

    Muzio, Giuliana; Martinasso, Germana; Baino, Francesco; Frairia, Roberto; Vitale-Brovarone, Chiara; Canuto, Rosa A

    2014-11-01

    In this work, the role of shock wave-induced increase of bone morphogenetic proteins in modulating the osteogenic properties of osteoblast-like cells seeded on a bioactive scaffold was investigated using gremlin as a bone morphogenetic protein antagonist. Bone-like glass-ceramic scaffolds, based on a silicate experimental bioactive glass developed at the Politecnico di Torino, were produced by the sponge replication method and used as porous substrates for cell culture. Human MG-63 cells, exposed to shock waves and seeded on the scaffolds, were treated with gremlin every two days and analysed after 20 days for the expression of osteoblast differentiation markers. Shock waves have been shown to induce osteogenic activity mediated by increased expression of alkaline phosphatase, osteocalcin, type I collagen, BMP-4 and BMP-7. Cells exposed to shock waves plus gremlin showed increased growth in comparison with cells treated with shock waves alone and, conversely, mRNA contents of alkaline phosphatase and osteocalcin were significantly lower. Therefore, the shock wave-mediated increased expression of bone morphogenetic protein in MG-63 cells seeded on the scaffolds is essential in improving osteogenic activity; blocking bone morphogenetic protein via gremlin completely prevents the increase of alkaline phosphatase and osteocalcin. The results confirmed that the combination of glass-ceramic scaffolds and shock waves exposure could be used to significantly improve osteogenesis opening new perspectives for bone regenerative medicine. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

  1. TGF-β1 Improves Biomechanical Strength by Extracellular Matrix Accumulation Without Increasing the Number of Tenogenic Lineage Cells in a Rat Rotator Cuff Repair Model.

    Science.gov (United States)

    Arimura, Hitoshi; Shukunami, Chisa; Tokunaga, Takuya; Karasugi, Tatsuki; Okamoto, Nobukazu; Taniwaki, Takuya; Sakamoto, Hidetoshi; Mizuta, Hiroshi; Hiraki, Yuji

    2017-08-01

    Transforming growth factor β1 (TGF-β1) positively regulates the tenogenic marker genes scleraxis ( Scx) and tenomodulin ( Tnmd) in mesenchymal progenitors in vitro. However, little is known about the effect of TGF-β1 on the expression of tenogenic markers during rotator cuff (RC) healing in rats. TGF-β1 improves the biomechanical properties and histological maturity of reparative tissue in a rat RC repair model by stimulating the growth of tenogenic cells. Controlled laboratory study. Adult male Sprague-Dawley rats (N = 180) underwent unilateral supraspinatus tendon-to-bone surgical repair and were randomly treated with a gelatin hydrogel presoaked in TGF-β1 (100 ng) or phosphate-buffered saline. The effects of TGF-β1 on RC healing were investigated at 2, 4, 6, 8, and 12 weeks postoperatively by immunostaining for proliferating cell nuclear antigen, by real-time reverse transcription polymerase chain reaction and in situ hybridization or immunostaining for enthesis-related markers (SRY-box containing gene 9 [ Sox9], Scx, and Tnmd), and by real-time reverse transcription polymerase chain reaction and immunostaining for type I and III collagen. At 6 and 12 weeks postoperatively, biomechanical testing, micro-computed tomography, and biochemical analysis were also performed. At 2 and 4 weeks postoperatively, mesenchymal stem cell-related markers, phospho-Smad2, and matrix metalloproteinase 9 (MMP-9) and MMP-13 were assessed by immunostaining. The TGF-β1-treated group had significantly higher ultimate load to failure and tissue volume at 6 and 12 weeks postoperatively and a higher collagen content at 12 weeks compared with the saline group. Tendon-related gene expression, histological maturity, cell proliferation, and mesenchymal stem cell-related marker immunoreactivity were not affected by exogenously administrated TGF-β1 at all time points. In the TGF-β1-treated group, the percentage of phospho-Smad2-positive cells within the healing tissue increased

  2. Reconstruction of metabolic module with improved promoter strength increases the productivity of 2-phenylethanol in Saccharomyces cerevisiae.

    Science.gov (United States)

    Wang, Zhaoyue; Jiang, Mingyue; Guo, Xuena; Liu, Zhaozheng; He, Xiuping

    2018-04-11

    2-phenylethanol (2-PE) is an important aromatic compound with a lovely rose-like scent. Saccharomyces cerevisiae is a desirable microbe for 2-PE production but its natural yield is not high, and one or two crucial genes' over-expression in S. cerevisiae did not improve 2-PE greatly. A new metabolic module was established here, in which, permease Gap1p for L-phenylalanine transportation, catalytic enzymes Aro8p, Aro10p and Adh2p in Ehrlich pathway respectively responsible for transamination, decarboxylation and reduction were assembled, besides, glutamate dehydrogenase Gdh2p was harbored for re-supplying another substrate 2-oxoglutarate, relieving product glutamate repression and regenerating cofactor NADH. Due to different promoter strengths, GAP1, ARO8, ARO9, ARO10, ADH2 and GDH2 in the new modularized YS58(G1-A8-A10-A2)-GDH strain enhanced 11.6-, 15.4-, 3.6-, 17.7-, 12.4- and 7.5-folds respectively, and crucial enzyme activities of aromatic aminotransferases and phenylpyruvate decarboxylase were 4.8- and 7-folds respectively higher than that of the control. Under the optimum medium and cell density, YS58(G1-A8-A10-A2)-GDH presented efficient 2-PE synthesis ability with ~ 6.3 g L -1 of 2-PE titer in 5-L fermenter reaching 95% of conversation ratio. Under fed-batch fermentation, 2-PE productivity at 24 h increased 29% than that of single-batch fermentation. Metabolic modularization with promoter strategy provides a new prospective for efficient 2-PE production.

  3. Increasing the calcium content of mealworms (Tenebrio molitor) to improve their nutritional value for bone mineralization of growing chicks.

    Science.gov (United States)

    Klasing, K C; Thacker, P; Lopez, M A; Calvert, C C

    2000-12-01

    The purpose of these studies was to determine the husbandry variables that optimize the Ca content of mealworms (Tenebrio molitor) and to determine the bioavailability of this Ca for bone mineralization in chicks that consume the mealworms. To determine the optimal level of Ca in the substrates used in short-term (mealworms and to determine the length of time that mealworms should be exposed to high-Ca substrates, mealworms were placed in either a wheat bran or a chicken starter substrate supplemented with 0, 4, 8, or 12% Ca from CaCO3. The mealworms were harvested after 0.5, 1, 2, 3, 4, 7, or 14 days. The Ca content of the mealworms was greatest with the use of chicken starter and increased linearly with the Ca content of the substrate. In general, the Ca content of the mealworms increased during the first 24 hr and decreased after > or = 1 wk, especially at the higher levels of Ca supplementation. The chicken starter also resulted in higher levels of vitamin D in mealworms. Mealworms held in wheat bran with 8% Ca were fed to growing chicks. Ca bioavailability was calculated from the chicks' bone ash. The Ca in these mealworms was 76% as bioavailable as the Ca in oyster shell.

  4. [Bone homeostasis and Mechano biology.

    Science.gov (United States)

    Nakashima, Tomoki

    The weight-bearing exercises help to build bones and to maintain them strength. Bone is constantly renewed by the balanced action of osteoblastic bone formation and osteoclastic bone resorption both of which mainly occur at the bone surface. This restructuring process called "bone remodeling" is important not only for normal bone mass and strength, but also for mineral homeostasis. Bone remodeling is stringently regulated by communication between bone component cells such as osteoclasts, osteoblasts and osteocytes. An imbalance of this process is often linked to various bone diseases. During bone remodeling, resorption by osteoclasts precedes bone formation by osteoblasts. Based on the osteocyte location within the bone matrix and the cellular morphology, it is proposed that osteocytes potentially contribute to the regulation of bone remodeling in response to mechanical and endocrine stimuli.

  5. Bone graft revascularization strategies

    NARCIS (Netherlands)

    Willems, W.F.

    2014-01-01

    Reconstruction of avascular necrotic bone by pedicled bone grafting is a well-known treatment with little basic research supporting its application. A new canine model was used to simulate carpal bone avascular necrosis. Pedicled bone grafting proved to increase bone remodeling and bone blood flow,

  6. Voltage-stabilised elastomers with increased relative permittivity and high electrical breakdown strength by means of phase separating binary copolymer blends of silicone elastomers

    DEFF Research Database (Denmark)

    A Razak, Aliff Hisyam; Yu, Liyun; Skov, Anne Ladegaard

    2017-01-01

    Increased electrical breakdown strength and increased dielectric permittivity of silicone-based dielectric elastomers are achieved by means of the addition of so-called voltage-stabilisers prepared from PDMS–PPMS copolymers as well as PDMS–PEG copolymers in order to compensate for the negative...... effect of softness on electrical stability of silicone elastomers. The voltage-stabilised elastomer, incorporating a high-permittivity PDMS–PEG copolymer, possesses increased relative permittivity, high electrical breakdown strength, excellent network integrity and low dielectric loss and paves the way...

  7. Sacrococcygeal chordoma: increased 99mTc methylene diphosphonate uptake on single photon emission computed tomography/computed tomography bone scintigraphy

    International Nuclear Information System (INIS)

    Kamaleshwaran, Koramadai Karuppuswamy; Bhattacharya, Anish; Harisankar, Chidambaram Natarajan Balasubramaniam; Mittal, Bhagwant Rai; Goni, Vijay

    2012-01-01

    Chordoma is a malignant tumor arising from the remnants of the notochord, and is the most frequent primitive tumor of the sacrum. While most sacral tumors show increased concentration of bone-seeking radiopharmaceuticals, chordomas usually exhibit decreased uptake. The authors present an image of a sacrococcygeal chordoma with osteolysis and increased uptake of 99m Tc methylene diphosphonate on planar and single photon emission computed tomography/computed tomography bone scintigraphy. (author)

  8. The risk of renal disease is increased in lambda myeloma with bone marrow amyloid deposits

    Directory of Open Access Journals (Sweden)

    Kozlowski P

    2017-03-01

    Full Text Available Piotr Kozlowski,1 Scott Montgomery,2–4 Rahel Befekadu,5 Victoria Hahn-Strömberg6 1Department of Medicine, School of Medical Sciences, Örebro University, Örebro, Sweden; 2Clinical Epidemiology and Biostatistics, School of Medical Sciences, Örebro University, Örebro, Sweden; 3Clinical Epidemiology Unit, Karolinska University Hospital, Karolinska Institutet, Stockholm, Sweden; 4Department of Epidemiology and Public Health, University College London, London, UK; 5Department of Transfusion Medicine, School of Medical Sciences, Örebro University, Örebro, Sweden; 6Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden Background: Light chain amyloidosis (AL is a rare deposition disease and is present in 10–15% of patients with myeloma (MM. In contrast to symptomatic AL in MM, presence of bone marrow (BM amyloid deposits (AD in MM is not connected to kidney damage. Renal AD but not BM-AD occur mostly in MM with lambda paraprotein (lambda MM. Methods: We investigated amyloid presence in BM clots taken at diagnosis in 84 patients with symptomatic MM and compared disease characteristics in MM with kappa paraprotein (kappa MM/lambda MM with and without BM-AD. Results: Lambda MM with BM-AD was compared with kappa MM without BM-AD, kappa MM with BM-AD, and lambda MM without BM-AD: lambda MM with BM-AD patients had a significantly higher mean creatinine level (4.23 mg/dL vs 1.69, 1.14, and 1.28 mg/dL, respectively and a higher proportion presented with severe kidney failure (6/11 [55%] vs 6/32 [19%], 1/22 [5%], and 3/19 [16%], respectively. Proteinuria was more common in lambda MM with BM-AD patients compared with kappa MM without BM-AD patients (8/11 [73%] vs 5/32 [16%], respectively. Conclusion: Kidney damage was more common in lambda MM with BM-AD indicating presence of renal AD. Keywords: plasma cells, neoplasms, amyloidosis, renal insufficiency, proteinuria

  9. Using Micro-CT Derived Bone Microarchitecture to Analyze Bone Stiffness - A Case Study on Osteoporosis Rat Bone

    Directory of Open Access Journals (Sweden)

    Yuchin eWu

    2015-05-01

    Full Text Available Micro-computed tomography images can be used to quantitatively represent bone geometry through a range of computed attenuation-based parameters. Nonetheless, those parameters remain indirect indices of bone micro-architectural strength and require further computational tools to interpret bone structural stiffness and potential for mechanical failure. Finite element analysis (FEA can be applied to measure trabecular bone stiffness and potentially predict the location of structural failure in preclinical animal models of osteoporosis, although that procedure from image segmentation of micro-CT derived bone geometry to FEA is often challenging and computationally expensive, resulting in failure of the model to build. Notably, the selection of resolution and threshold for bone segmentation are key steps that greatly affect computational complexity and validity. In the following study, we evaluated an approach whereby Micro-CT derived greyscale attenuation and segmentation data guided the selection of trabecular bone for analysis by FEA. We further correlated those FEA results to both two and three dimensional bone microarchitecture from sham and ovariectomized (OVX rats (n=10/group. A virtual cylinder of vertebral trabecular bone 40% in length from the caudal side was selected for FEA because micro-CT based image analysis indicated the largest differences in microarchitecture between the two groups resided there. Bone stiffness was calculated using FEA and statistically correlated with the three dimensional values of bone volume/tissue volume, bone mineral density, fractal dimension, trabecular separation and trabecular bone pattern factor. Our method simplified the process for the assessment of trabecular bone stiffness by FEA from Micro-CT images and highlighted the importance of bone microarchitecture in conferring significantly increased bone quality capable of resisting failure due to increased mechanical loading.

  10. Winter vitamin D3 supplementation does not increase muscle strength, but modulates the IGF-axis in young children

    DEFF Research Database (Denmark)

    Mortensen, Charlotte; Mølgaard, Christian; Hauger, Hanne

    2018-01-01

    dynamometer, fat mass index (FMI), fat free mass index (FFMI), height, plasma IGF-1, IGF-binding protein 3 (IGFBP-3), and serum 25(OH)D. RESULTS: At baseline, serum 25(OH)D was positively associated with muscle strength, FFMI, and IGFBP-3 in girls only (all p muscle......PURPOSE: To explore whether muscle strength, the insulin-like growth factor axis (IGF-axis), height, and body composition were associated with serum 25-hydroxyvitamin D [25(OH)D] and affected by winter vitamin D supplementation in healthy children, and furthermore to explore potential sex...... differences. METHODS: We performed a double-blind, placebo-controlled, dose-response winter trial at 55ºN. A total of 117 children aged 4-8 years were randomly assigned to either placebo, 10, or 20 µg/day of vitamin D3 for 20 weeks. At baseline and endpoint, we measured muscle strength with handgrip...

  11. Pedicle distraction increases intervertebral and spinal canal area in a cadaver and bone model

    Directory of Open Access Journals (Sweden)

    Hughes Matthew

    2018-01-01

    Discussion: For each increase in pedicle distraction the area of the spinal and vertebral foramen increases. Pedicle distraction could potentially be used to alleviate spinal stenosis and root impingement. A potential osteotomy plane could be at the midpoint of the pedicle with minimal risk to nerve roots and soft tissue restrictions to prevent distraction.

  12. Promotion of osteogenic differentiation of stem cells and increase of bone-bonding ability in vivo using urease-treated titanium coated with calcium phosphate and gelatin

    Science.gov (United States)

    Huang, Zhong-Ming; Qi, Yi-Ying; Du, Shao-Hua; Feng, Gang; Unuma, Hidero; Yan, Wei-Qi

    2013-10-01

    Because of its excellent biocompatibility and low allergenicity, titanium has been widely used for bone replacement and tissue engineering. To produce a desirable composite with enhanced bone response and mechanical strength, in this study bioactive calcium phosphate (CaP) and gelatin composites were coated onto titanium (Ti) via a novel urease technique. The cellular responses to the CaP/gelatin/Ti (CaP/gel/Ti) and bone bonding ability were evaluated with proliferation and osteogenic differentiation of mesenchymal stem cells (MSCs) on CaP/gel/Ti and CaP/Ti in vitro. The results showed that the optical density values, alkaline phosphatase expression and genes expression of MSCs on CaP/gel/Ti were similar to those on CaP/Ti, yet significantly higher than those on pure Ti (p layer. An interfacial layer, containing Ti, Ca and P, was found to form at the interface between bone and the implant on all three groups by EDS analysis. However, the content of Ca, P in the surface of CaP/gel/Ti implants was more than in the other two groups at each time point. The CaP/gel/Ti modified by the urease method was not only beneficial for MSCs proliferation and osteogenic differentiation, but also favorable for bone bonding ability on Ti implants in vivo, suggesting that Ti functionalized with CaP and gelatin might have a great potential in clinical joint replacement or dental implants.

  13. In-vivo assessment of femoral bone strength using Finite Element Analysis (FEA based on routine MDCT imaging: a preliminary study on patients with vertebral fractures.

    Directory of Open Access Journals (Sweden)

    Hans Liebl

    derived FEA models may assess bone strength more accurately than BMD measurements alone, providing a valuable in-vivo fracture risk assessment tool.

  14. Increased linear bone growth by GH in the absence of SOCS2 is independent of IGF-1.

    Science.gov (United States)

    Dobie, Ross; Ahmed, Syed F; Staines, Katherine A; Pass, Chloe; Jasim, Seema; MacRae, Vicky E; Farquharson, Colin

    2015-11-01

    Growth hormone (GH) signaling is essential for postnatal linear bone growth, but the relative importance of GHs actions on the liver and/or growth plate cartilage remains unclear. The importance of liver derived insulin like-growth factor-1 (IGF-1) for endochondral growth has recently been challenged. Here, we investigate linear growth in Suppressor of Cytokine Signaling-2 (SOCS2) knockout mice, which have enhanced growth despite normal systemic GH/IGF-1 levels. Wild-type embryonic ex vivo metatarsals failed to exhibit increased linear growth in response to GH, but displayed increased Socs2 transcript levels (P growth over a 12 day period. Despite this increase, IGF-1 transcript and protein levels were not increased in response to GH. In accordance with these data, IGF-1 levels were unchanged in GH-challenged postnatal Socs2(-/-) conditioned medium despite metatarsals showing enhanced linear growth. Growth-plate Igf1 mRNA levels were not elevated in juvenile Socs2(-/-) mice. GH did however elevate IGF-binding protein 3 levels in conditioned medium from GH challenged metatarsals and this was more apparent in Socs2(-/-) metatarsals. GH did not enhance the growth of Socs2(-/-) metatarsals when the IGF receptor was inhibited, suggesting that IGF receptor mediated mechanisms are required. IGF-2 may be responsible as IGF-2 promoted metatarsal growth and Igf2 expression was elevated in Socs2(-/-) (but not WT) metatarsals in response to GH. These studies emphasise the critical importance of SOCS2 in regulating GHs ability to promote bone growth. Also, GH appears to act directly on the metatarsals of Socs2(-/-) mice, promoting growth via a mechanism that is independent of IGF-1. © 2014 The Authors. Journal of Cellular Physiology Published by Wiley Periodicals, Inc.

  15. Prognostic significance of increased bone marrow microcirculation in newly diagnosed multiple myeloma: results of a prospective DCE-MRI study

    Energy Technology Data Exchange (ETDEWEB)

    Merz, Maximilian; Hillengass, Jens [Department of Radiology, German Cancer Research Center, Heidelberg (Germany); University of Heidelberg, Department of Hematology, Oncology and Rheumatology, Heidelberg (Germany); Moehler, Thomas M.; Ritsch, Judith; Delorme, Stefan [Department of Radiology, German Cancer Research Center, Heidelberg (Germany); Baeuerle, Tobias [University of Erlangen-Nuremberg, Department of Radiology, Erlangen (Germany); Zechmann, Christian M. [Rinecker Proton Therapy, Muenchen (Germany); Wagner, Barbara; Hose, Dirk [University of Heidelberg, Department of Hematology, Oncology and Rheumatology, Heidelberg (Germany); Jauch, Anna [University of Heidelberg, Institute of Human Genetics, Heidelberg (Germany); Kunz, Christina; Hielscher, Thomas [German Cancer Research Center, Department of Biostatistics, Heidelberg (Germany); Laue, Hendrik [Fraunhofer MEVIS, Bremen (Germany); Goldschmidt, Hartmut [University of Heidelberg, Department of Hematology, Oncology and Rheumatology, Heidelberg (Germany); National Center for Tumor Diseases, Heidelberg (Germany)

    2016-05-15

    Aim of this prospective study was to investigate prognostic significance of increased bone marrow microcirculation as detected by dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) for survival and local complications in patients with multiple myeloma (MM). We performed DCE-MRI of the lumbar spine in 131 patients with newly diagnosed MM and analysed data according to the Brix model to acquire amplitude A and exchange rate constant k{sub ep}. In 61 patients a second MRI performed after therapy was evaluated to assess changes in vertebral height and identify vertebral fractures. Correlation analysis revealed significant positive association between beta2-microglobulin as well as immunoparesis with DCE-MRI parameters A and k{sub ep}. Additionally, A was negatively correlated with haemoglobin levels and k{sub ep} was positively correlated with LDH levels. Higher baseline k{sub ep} values were associated with decreased vertebral height in a second MRI (P = 0.007) and A values were associated with new vertebral fractures in the lower lumbar spine (P = 0.03 for L4). Pre-existing lytic bone lesions or remission after therapy had no impact on the occurrence of vertebral fractures. Multivariate analysis revealed that amplitude A is an independent adverse risk factor for overall survival. DCE-MRI is a non-invasive tool with significance for systemic prognosis and vertebral complications. (orig.)

  16. Pedicle distraction increases intervertebral and spinal canal area in a cadaver and bone model.

    Science.gov (United States)

    Hughes, Matthew; Papadakos, Nikolaos; Bishop, Tim; Bernard, Jason

    2018-01-01

    Lumbar spinal stenosis is degenerative narrowing of the spinal canal and/or intervertebral foramen causing compression of the spinal cord and nerve roots. Traditional decompression techniques can often cause significant trauma and vertebral instability. This paper evaluates a method of increasing pedicle length to decompress the spinal and intervertebral foramen, which could be done minimally invasive. Three Sawbone (Sawbones Europe, Sweden) and 1 cadaveric lumbar spine underwent bilateral pedicle distraction at L4. A pedicle channel was drilled between the superior articular process and transverse process into the vertebral body. The pedicles underwent osteotomy at the midpoint. Screws were inserted bilaterally and fixated distraction of 0 mm, 2 mm, 4 mm and 6 mm. CT images were taken at each level of distraction. Foramen area was measured in the sagittal plane at L3/4. Spinal canal area was measured at L4 in the axial images. The cadaver was used to evaluate safety of osteotomy and soft tissue interactions preventing distraction. Statistical analysis was by student paired t-test and Pearson rank test. Increasing distraction led to greater Spinal canal area. From 4.27 cm 2 to 5.72 cm 2 (p = 0.002) with 6 mm distraction. A Maximal increase of 34.1%. Vertebral foramen area also increased with increasing pedicle distraction. From 2.43 cm 2 to 3.22 cm 2 (p = 0.022) with 6 mm distraction. A maximal increase of 32.3%. The cadaver spinal canal increase