979 resultados para Biology, Biomechanics, Bone, Fracture repair, Healing


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A robust, electrically conductive, superamphiphobic fabric was prepared by vapour-phase polymerisation of 3,4-ethylenedioxythiophene (EDOT) on fabric in the presence of fluorinated decyl polyhedral oligomeric silsesquioxane (FD-POSS) and a fluorinated alkyl silane (FAS). The coated fabric had contact angles of 169° and 156° respectively to water and hexadecane, and a surface resistance in the range of 0.8–1.2 kΩ o⁻¹ . The incorporation of FD-POSS and FAS into the PEDOT layer showed a very small influence on the conductivity but improved the washing and abrasion stability considerably. The coated fabric can withstand at least 500 cycles of standard laundry and 10000 cycles of abrasion without apparently changing the superamphiphobicity, while the conductivity only had a small reduction after the washing and abrasion. More interestingly, the coating had a self-healing ability to auto-repair from chemical damages to restore the liquid repellency.

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Abstract:
Postmenopausal women on aromatase inhibitors (AI) are at risk of aromatase inhibitor-associated bone loss (AIBL) and fractures.

In 2005 Osteoporosis Australia proposed an algorithm for bisphosphonate intervention. Three hundred and three postmenopausal women with early breast cancer (EBC) were enrolled (osteoporotic, n=25; osteopaenic, n=146; normal bone mineral density (BMD), n=126). Weekly alendronate (70 mg) treatment efficacy as triggered by the algorithm in preventing bone loss was evaluated. All patients received anastrozole (1 mg daily), calcium and vitamin D.

Results:
All osteoporotic patients received alendronate at baseline. Eleven out of the 146 (7.5%) osteopaenic patients commenced alendronate within 18 months of participation and eleven commenced after. One hundred and twenty four out of the 146 (84.9%) osteopaenic patients and all 126 with normal baseline BMD did not trigger the algorithm.

At three years, lumbar spine mean BMD increased (15.6%, p<0.01) in the osteoporotic group. BMD in the osteopaenic group with early intervention significantly increased at three years (6.3%, p=0.02). No significant change was seen in the late intervention group. No change was observed in those with osteopaenia without alendronate.

There was a significant drop in lumbar spine (−5.4%) and hip (−4.5%) mean BMD, in the normal BMD group, none of whom received alendronate.

Fracture data will be presented.

Conclusion:
In postmenopausal women with endocrine-responsive EBC, BMD improved over time when a bisphosphonate is administered with anastrozole in osteoporotic patients using an osteoporosis schedule. Subjects with normal baseline BMD experienced the greatest BMD loss, although none became osteoporotic.

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Runt related transcription factor 2 (RUNX2) is a key regulator of osteoblast differentiation. Several variations within the RUNX2 gene have been found to be associated with significant changes in BMD, which is a major risk factor for fracture. In this study we report that an 18 bp deletion within the polyalanine tract (17A>11A) of RUNX2 is significantly associated with fracture. Carriers of the 11A allele were found to be nearly twice as likely to have sustained fracture. Within the fracture category, there was a significant tendency of 11A carriers to present with fractures of distal radius and bones of intramembranous origin compared to bones of endochondral origin (p = 0.0001). In a population of random subjects, the 11A allele was associated with decreased levels of serum collagen cross links (CTx, p = 0.01), suggesting decreased bone turnover. The transactivation function of the 11A allele showed a minor quantitative decrease. Interestingly, we found no effect of the 11A allele on BMD at multiple skeletal sites. These findings suggest that the 11A allele is a biologically relevant polymorphism that influences serum CTx and confers enhanced fracture risk in a site-selective manner related to intramembranous bone ossification.

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The authors compared the calibration of FRAX tools from Canada, the US (white), UK, Sweden, France, Australia, New Zealand, and China when used to assess fracture risk in 36,730 Canadian women. Their data underscores the importance of applying country-specific FRAX tools that are based upon high-quality national fracture epidemiology.

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We have investigated the role of bone sialoprotein (BSP), a secreted glycoprotein normally found in bone, in breast cancer progression. To explore functions for BSP in human breast cancer invasion and metastasis, the full-length BSP cDNA was transfected into the MDA-MB-231-BAG human breast cancer cell line under the control of the CMV promoter. Clones expressing BSP and vector control clones were isolated. BSP producing clones showed increased monolayer wound healing, a faster rate of stellate outgrowth in Matrigel and increased rate of invasion into a collagen matrix when compared to control clones. Clones were also examined in models of breast cancer growth and metastasis in vivo. BSP transfected clones showed an increased rate of primary tumor growth following mammary fat pad injection of nude mice. BSP transfected clones and vector control clones metastasized to soft organs and bone at a similar rate after intra-cardiac injection as determined by real-time PCR and X-ray analysis. Although these organs were targets for both BSP transfected and non-transfected cells, the size of the metastatic lesion was shown to be significantly larger for BSP expressing clones. This was determined by real-time PCR analysis for soft organs and by X-ray analysis of bone lesions. For bone this was confirmed by intra-tibial injections of cells in nude mice. We conclude that BSP acts to drive primary and secondary tumor growth of breast cancers in vivo.

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We investigated the reasons for referral of older Australians aged 70 years and older to dual energy X-ray absorptiometry (DXA). The most common clinical indication was being aged 70 years and older, followed by monitoring for fracture or low bone mineral density (BMD). Compared to males, females were twice as likely to have osteoporotic BMD.

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We investigated the association between undercarboxylated osteocalcin (ucOC) and lower-limb muscle strength in women over the age of 70years. The study also aims to confirm the association between bone turnover markers and heel ultrasound measures. A post-hoc analysis using data collected as part of a randomized placebo-controlled trial of vitamin D supplementation. An immunoassay was used to quantify total OC (tOC), with hydroxyapatite pre-treatment for ucOC. We determined associations of absolute and relative (ucOC/tOC; ucOC%) measures of ucOC with lower-limb muscle strength, heel ultrasound measures of speed of sound (SOS) and broadband ultrasound attenuation (BUA), bone turnover markers (BTMs; P1NP and CTx) and the acute phase protein alpha-1-antichymotrypsin (α-ACT). ucOC%, but not absolute ucOC concentration, was positively associated with hip flexor, hip abductor and quadriceps muscle strength (all p<0.05). ucOC% was negatively associated with α-ACT (β-coefficient=-0.24, p=0.02). tOC was positively associated with both P1NP and CTx (p<0.001). For each per unit increase in tOC (μg/L) there was a corresponding lower BUA, SOS and SI (β-coefficient = -0.28; -0.23 and -0.23, respectively; all p<0.04). In conclusion, ucOC% is positively associated with muscle strength and negatively associated with α-ACT. These data support a role for ucOC in musculoskeletal interactions in humans. Whilst tOC is associated with bone health, ucOC% and ucOC may also be linked to falls and fracture risk by influencing muscle function.

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Osteoporosis is a major health concern, estimated to affect millions worldwide. Bone mineral density (BMD) assessment is not practical for many large-scale epidemiological studies resulting in the reliance of self-report methods to ascertain diagnostic information. The aim of the study was to assess the validity of self-reported diagnosis of osteoporosis in a population-based study. This study examined data collected from 906 men and 843 women participating in the Geelong Osteoporosis Study. Osteoporosis was self-reported and compared against results of BMD scans of the hip and spine. Validity was examined by calculating sensitivity, specificity, positive predictive value, negative predictive value, and kappa statistic. Osteoporosis was self-reported by 118 (6.7%) participants and identified using BMD results for 64 (3.7%) participants. Specificity and negative predictive value were good (95.1% and 96.0%, respectively), whereas sensitivity and positive predictive value were poor (35.9% and 31.4%, respectively). The overall level of agreement (kappa) was 0.29. The results changed only slightly when we included participants with osteopenia and adult fracture as osteoporotic. Reliance on self-report methods to ascertain osteoporosis status is not recommended.

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There are few data documenting the pattern of prevalent fracture across the entire adult age range, so we aimed to address this gap by investigating the prevalence of fractures in an Australian cohort. All-cause (ever) fractures were identified for males and females enrolled in the Geelong Osteoporosis Study (Australia) using a combination of radiology-confirmed and self-reported data. First fractures were used to generate age-related frequencies of individuals who had ever sustained a fracture. Of 1,538 males and 1,731 females, 927 males and 856 females had sustained at least one fracture since birth. The proportion of all prevalent fractures in the 0-10 year age group was similar for both sexes (~10 %). In males, the proportion with prevalent fracture increased to 34.1 % for age 11-20 year. Smaller increases were observed into mid-life, reaching a plateau at ~50 % from mid to late life. The age-related prevalence of fracture for females showed a more gradual increase until mid-life. For adulthood prevalent fractures, approximately 20 % of males had sustained a first adulthood fracture in the 20-30 year age group, with a gradual increase up to the oldest age group (49.1 %), while females showed an exponential pattern of increase from the 20-30 year age group (6.8 %) to the oldest age group (60.4 %). In both sexes, those who had not sustained a fracture in childhood or early adulthood generally appeared to remain fracture-free until at least the sixth decade. When considering the prevalence of adulthood fractures across the age groups, males showed a gradual increase while females showed an exponential increase.

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Background: Our objective was to investigate associations between adulthood fracture and quality of life (QOL) in men. Methods: For 448 men aged 50-85 years and enrolled in the Geelong Osteoporosis Study, we measured QOL using the validated (Australian) World Health Organization Quality of Life-Brief Version (WHOQOL-Bref) in the domains of physical health, psychological health, social relationships, and the environment. Self-reported adulthood fractures were categorized as recent or non-recent ( ≤ 10 years or > 10 years pre-QOL assessment, respectively). Lifestyle and health information were self-reported. Results: One hundred seventy four men (38.8%) sustained at least one fracture, 26% of which had occurred within the last 10 years. Compared with men who had never had an adulthood fracture, a non-recent fracture was more likely associated with poorer QOL in the physical health domain (age-adjusted odds ratio [OR] 0.47, 95% confidence interval [95%CI] 0.27-0.83), but not in any other domain. Men who had sustained a recent fracture reported a lower QOL in the domain of psychological health (age-adjusted OR 0.48, 95%CI 0.24-0.97), with a trend observed for lower QOL in the domains of physical health and environment. No further associations were observed. All results were sustained in further models that were adjusted for smoking, alcohol, physical inactivity, and body mass index. Conclusions: We present novel data examining associations between fracture status and QOL in a populationbased sample of Australian men using the WHOQOL-Bref. Recent fractures were associated with poorer QOL in the domain of psychological health while non-recent fractures were more likely associated poorer QOL for physical health. These findings have important implications for healthcare post-fracture.

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Critical illness may lead to altered bone turnover and associated adverse health outcomes. This systematic review found moderate evidence for a positive association between critical illness and increased bone turnover. Prospective cohort studies that identify the extent and risk factors for critical illness related bone loss are required.

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UNLABELLED: Carpal fractures were identified by the Geelong Osteoporosis Study Fracture Grid for 2006-2007. Incidence rates were higher in males than females. Males had a lower median age of fracture than females. Females had more fractures on the left side than males. Most fractures were the result of a fall. PURPOSE: In this study, we report the incidence of carpal bone fractures (scaphoid and non-scaphoid) amongst residents from the Barwon Statistical Division over 2 years. METHODS: X-ray reports from imaging centres in the region were used to identify incident fractures during 2006 and 2007. Data were collected as part of the Geelong Osteoporosis Study Fracture Grid. RESULTS: During 2006 and 2007, there were 171 and 41 carpal fractures in males and females, respectively. Of these, 131 males and 29 females had fractured the scaphoid bone. Females had a higher proportion of left-sided fractures (>70 %) than males (∼40 %). Most fractures were the result of an accidental fall (>87 %). Patterns of incidence for males showed one major peak around 20-29 years. For females, peaks occurred around age 10-19 years and 70-79 years. Incidence rates for males (per 100,000 persons per year) were 54.6 (95 % confidence interval (CI) 53.6, 55.7) and 15.9 (95 % CI 15.4, 16.5) for scaphoid and non-scaphoid fractures, respectively. In females, the corresponding rates were 10.6 (95 % CI 10.2, 11.1) and 4.5 (95 % CI 4.2, 4.8). CONCLUSION: Almost all fractures were the result of a fall. In males, carpal fractures were sustained mainly during early adulthood and in females during adolescence and after menopause. Incidence rates for males were higher than those in females for both scaphoid and non-scaphoid fractures.

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Due to their differing etiologies and consequences, it has been proposed that the term "sarcopenia" should revert to its original definition of age-related muscle mass declines, with a separate term, "dynapenia", describing muscle strength and function declines. There is increasing interest in the interactions of sarcopenia and dynapenia with obesity. Despite an apparent protective effect of obesity on fracture, increased adiposity may compromise bone health, and the presence of sarcopenia and/or dynapenia ("sarcopenic obesity" and "dynapenic obesity") may exacerbate the risk of falls and fracture in obese older adults. Weight loss interventions are likely to be beneficial for older adults with sarcopenic and dynapenic obesity but may result in further reductions in muscle and bone health. The addition of exercise including progressive resistance training and nutritional strategies, including protein and vitamin D supplementation, may optimise body composition and muscle function outcomes thereby reducing falls and fracture risk in this population.