Complications after surgical treatment of femoral neck fractures in men with alcohol dependence syndrome: retrospective register analysis of 154 cases

PURPOSE

One-third of hip fractures occur in men. The causes underlying hip fractures in men differ from those in women and include alcohol abuse. This retrospective register study evaluated the trends and results associated with different surgical treatment methods for nondisplaced and displaced femoral neck fractures in male patients with alcohol dependence syndrome.

METHODS

Men with hip fractures were identified from a local district hospital database. Alcohol dependence syndrome was identified as a diagnosis in medical records.

RESULTS

For displaced fractures, implant survival after total hip arthroplasty was significantly lower compared to hemiarthroplasty. For nondisplaced fractures, implant survival of cannulated screws was significantly lower compared to sliding hip screws. Overall patient survival for males with alcohol dependence syndrome with hip fracture was 62% at 1 year and 49% at 2 years. Patient survival in this population did not differ between displaced and nondisplaced fractures or among different surgical methods.

CONCLUSION

Patients with alcoholism who had documented evidence of alcohol dependence syndrome represented nearly half of patients <70 years old with low-energy hip fracture. In patients with nondisplaced femoral neck fractures, stability of the internal fixation appeared to play a major role in implant survival; sliding hip screws should be considered over multiple cannulated screws. In patients with displaced fracture, total hip arthroplasty was associated with a significantly higher risk of complications leading to revision compared to hemiarthoplasty.

LEVEL OF EVIDENCE

Prognostic Level III.

Novel Antibacterial Coating on Orthopedic Wires To Eliminate Pin Tract Infections

Novel approaches to the prevention of microbial infections after the insertion of orthopedic external fixators are in great demand because of the extremely high incidence rates of such infections, which can reach up to 100% with longer implant residence times. Monolaurin is an antimicrobial agent with a known safety record that is broadly used in the food and cosmetic industries; however, its use in antimicrobial coatings of medical devices has not been studied in much detail. Here, we report the use of monolaurin as an antibacterial coating on external fixators for the first time. Monolaurin-coated Kirschner wires (K-wires) showed excellent antibacterial properties against three different bacterial strains, i.e., methicillin-sensitive Staphylococcus aureus (MSSA), methicillin-resistant Staphylococcus aureus (MRSA), and Staphylococcus epidermidis Approximately 6.0-log reductions of both planktonic and adherent bacteria were achieved using monolaurin-coated K-wires, but monolaurin-coated K-wires did not show any observable cytotoxicity with mouse osteoblast cell cultures. Overall, monolaurin-coated K-wires could be promising as potent antimicrobial materials for orthopedic surgery.

Glypican-based drug releasing titania implants to regulate BMP2 bioactivity as a potential approach for craniosynostosis therapy

Advances in molecular biology and nanomedicine based therapies hold promise to obviate the need of multiple surgical interventions (associated with current management) in craniosynostosis by preventing bone re-ossification. One such adjunctive therapy involves application of glypicans 1 and 3 (GPC1 and GPC3) that are BMP inhibitors implicated in downregulating the BMP2 activity in prematurely fusing sutures. Electrochemically anodized Titania nanotube (TNT) arrays have been recognized as a promising localized, long-term drug delivery platform for bone-related therapies. This study presents the application of nanoengineered TNT/Ti implants loaded with recombinant glypicans for craniosynostosis therapy. By using Dual luciferase Reporter assay, we tested the biofunctionality of eluted glypicans from the TNT/Ti implants for BMP2 bioactivity regulation in C2C12 murine myoblast cell line. BMP2 activity was inhibited significantly for up to 15days by the glypicans released from polymer-coated TNT/Ti implants, indicating their potential application in adjunctive craniosynostosis treatment.

Relationship between bone density and abdominal visceral fat in premenopausal overweight and obese Iranian women aged 30-50 years

AIM

The presence of a direct relationship between body mass index (BMI) and bone mineral density (BMD) is frequently reported. However, data on the relationship between visceral fat and bone density varies, with positive, negative or no relationship having been reported. This study aims to examine the relationship between abdominal visceral fat and BMD.

METHODS

A cross sectional study was carried out on 95 premenopausal, overweight and obese women aged 30-50 years referred to Sina Hospital, Tehran, Iran in 2011-2012. Anthropometric indices and visceral fat levels were measured.

RESULTS

Multiple linear regression analysis showed that proximal femur BMD (P = 0.856) and lumbar spine BMD (P = 0.558) were not significantly related to visceral fat level. However, BMI had a direct and significant positive relationship with proximal femur BMD (P = 0.001) and lumbar spine BMD (P = 0.031). Menarche age was negatively related to lumbar spine BMD (P = 0.003).

CONCLUSIONS

In this study, after adjusting for fat-free mass, no significant relationship was found between MBD of the proximal femur and lumbar spine, and visceral fat level or visceral fat to total fat percentage ratio. Therefore, abdominal visceral fat may not affect BMD, independent of weight. It seems that the positive relationship between BMI and proximal femur and lumbar spine BMD is due to the mechanical effects of weight on bones.

Burden of hip fracture using disability-adjusted life-years: a pooled analysis of prospective cohorts in the CHANCES consortium

BACKGROUND

No studies have estimated disability-adjusted life-years (DALYs) lost due to hip fractures using real-life follow-up cohort data. We aimed to quantify the burden of disease due to incident hip fracture using DALYs in prospective cohorts in the CHANCES consortium, and to calculate population attributable fractions based on DALYs for specific risk factors.

METHODS

We used data from six cohorts of participants aged 50 years or older at recruitment to calculate DALYs. We applied disability weights proposed by the National Osteoporosis Foundation and did a series of sensitivity analyses to examine the robustness of DALY estimates. We calculated population attributable fractions for smoking, body-mass index (BMI), physical activity, alcohol intake, type 2 diabetes and parity, use of hormone replacement therapy, and oral contraceptives in women. We calculated summary risk estimates across cohorts with pooled analysis and random-effects meta-analysis methods.

FINDINGS

223 880 men and women were followed up for a mean of 13 years (SD 6). 7724 (3·5%) participants developed an incident hip fracture, of whom 413 (5·3%) died as a result. 5964 DALYs (27 per 1000 individuals) were lost due to hip fractures, 1230 (20·6%) of which were in the group aged 75-79 years. 4150 (69·6%) DALYs were attributed to disability. Current smoking was the risk factor responsible for the greatest hip fracture burden (7·5%, 95% CI 5·2-9·7) followed by physical inactivity (5·5%, 2·1-8·5), history of diabetes (2·8%, 2·1-4·0), and low to average BMI (2·0%, 1·4-2·7), whereas low alcohol consumption (0·01-2·5 g per day) and high BMI had a protective effect.

INTERPRETATION

Hip fracture can lead to a substantial loss of healthy life-years in elderly people. National public health policies should be strengthened to reduce hip fracture incidence and mortality. Primary prevention measures should be strengthened to prevent falls, and reduce smoking and a sedentary lifestyle.

FUNDING

European Community's Seventh Framework Programme.

The associations between serum 25-hydroxyvitamin D level and the risk of total fracture and hip fracture

In this meta-analysis, we evaluated the association between serum 25-hydroxyvitamin D (25(OH) vitamin D) level and the risk of total fractures and hip fractures. Low serum 25(OH) vitamin D level is associated with an increased risk of total and hip fractures.

INTRODUCTION

Data on the association between serum 25(OH) vitamin D level and the risk of fractures are conflicting. This study aimed to provide a summary of prospective cohort or nested case-control studies on the association between serum 25(OH) vitamin D level and the risk of total fractures and hip fractures.

METHODS

We identified relevant studies by searching the PubMed, EMBASE, and OVID databases from their inception to June 1, 2016. We included published prospective cohort or nested case-control studies evaluating the associations of serum 25(OH) vitamin D level with the fracture risk. Two reviewers abstracted the data independently. Relative risks (RRs) with 95% confidence intervals (CIs) were derived throughout the whole analysis.

RESULTS

Sixteen prospective cohort studies and three nested case-control studies were included. We found that low serum 25(OH) vitamin D level was significantly associated with the risk of total fractures (RR 1.25, 95% CI 1.06-1.43; I ² = 31.3%, p for heterogeneity = 0.15) and hip fractures (RR 1.48, 95% CI 1.29-1.68; I ² = 0%, p for heterogeneity = 0.51). The hip fracture risk was increased by 40% for each SD decrease in serum 25(OH) vitamin D level (RR 1.40, 95% CI 1.20-1.61; I ² = 0%, p for heterogeneity = 0.51). The per SD decrease in serum 25(OH) vitamin D level was not associated with the increased risk of total fractures (RR 1.14, 95% CI 0.93-1.35; I ² = 63.2%, p for heterogeneity = 0.04).

CONCLUSIONS

Our study suggests that low serum 25(OH) vitamin D level is associated with increased risks of total and hip fractures. In the analyzed studies, the per SD decrease in serum 25(OH) vitamin D level was associated with the hip fracture risk but not with the total fracture risk.

Vitamin K intake and the risk of fractures: A meta-analysis

The association between dietary vitamin K intake and the risk of fractures is controversial. Therefore we perform a meta-analysis of cohort or nested case-control studies to investigate the relationship between dietary vitamin K intake and the risk of fractures. A comprehensive search of PubMed and EMBASE (to July 11, 2016) was performed to identify cohort or nested case-control studies providing quantitative estimates between dietary vitamin K intake and the risk of fractures. Summary relative risk (RRs) with corresponding 95% confidence intervals (CIs) were pooled by using a random-effects model. Four cohort studies and one nested case-control study, with a total of 1114 fractures cases and 80,982 participants, were included in our meta-analysis. Vitamin K intake in all included studies refers exclusively to the intake of phylloquinone (vitamin K1), which is the predominant form of vitamin K in foods. We observed a statistically significant inverse association between dietary vitamin K intake and risk of fractures (highest vs. the lowest intake, RR = 0.78, 95% CI: 0.56-0.99; I = 59.2%, P for heterogeneity = .04). Dose-response analysis indicated that the pooled RR of fracture for an increase of 50 μg dietary vitamin K intake per day was 0.97 (95% CI: 0.95-0.99) without heterogeneity among studies (I = 25.9%, P for heterogeneity = .25). When stratified by follow-up duration, the RR of fracture for dietary vitamin K intake was 0.76 (95% CI: 0.58-0.93) in studies with more than 10 years of follow-up. Our study suggests that higher dietary vitamin K intake may moderately decrease the risk of fractures.

Fast corroding, thin magnesium coating displays antibacterial effects and low cytotoxicity

Bacterial colonisation and biofilm formation are characteristics of implant-associated infections. In search of candidates for improved prosthetic materials, fast corroding Mg-based coatings on titanium surfaces were examined for their cytotoxic and antimicrobial properties. Human osteoblasts and Staphylococcus epidermidis were each cultured on cylindrical Ti samples coated with a thin layer of Mg/Mg₄₅Zn₅Ca, applied via magnetron sputtering. Uncoated titanium samples served as controls. S. epidermidis was quantified by counting colony forming units. The biofilm-bound fraction was isolated via ultrasonic treatment, and the planktonic fraction via centrifugation. Biofilm-bound S. epidermidis was significantly decreased by approximately four to five orders of magnitude in both Mg- and Mg₄₅Zn₅Ca-coated samples after seven days compared to the control. The osteoblast viability was within the tolerance threshold of 70% stated in DIN EN ISO 10993-5:2009-10 for Mg (~80%) but not for Mg₄₅Zn₅Ca (~25%). Accordingly, Mg-coated titanium was identified as a promising candidate for an implant material with antibacterial properties and low cytotoxicity levels. The approach of exploiting fast corrosion contrasts with existing methods, which have generally focused on reducing corrosion.

Staphylococcal protein A promotes osteoclastogenesis through MAPK signaling during bone infection

Bone infection is a common and serious complication in the orthopedics field, which often leads to excessive bone destruction and non‐union. Osteoclast is the only type of cells which have the function of bone resorption. Its over activation is closely related to excessive bone loss. Staphylococcus aureus (S. aureus) is a major pathogen causing bone infection, which can produce a large number of strong pathogenic substances staphylococcal protein A (SPA). However, few studies were reported about the effects of SPA on osteoclastogenesis. In our study, we observed that S. aureus activated osteoclasts and promoted bone loss in bone infection specimens. Then, we investigated the effects of SPA on RANKL‐induced osteoclastogenesis in vitro, the results revealed that SPA promoted osteoclastic differentiation and fusion, and enhanced osteoclastic bone resorption. In addition, we also showed that SPA upregulated the expression of NFATc1 and c‐FOS through the activation of MAPK signaling to promote osteoclastogenesis. Our findings might help us better understand the pathogenic role of S. aureus in bone infection and develop new therapeutic strategies for infectious bone diseases.

Plumbagin sensitizes breast cancer cells to tamoxifen-induced cell death through GRP78 inhibition and Bik upregulation

The glucose regulated protein 78 (GRP78) is a major chaperone of the endoplasmic reticulum, and a prosurvival component of the unfolded protein response. GRP78 is upregulated in many types of cancers, including breast cancer. Research has suggested that GRP78 overexpression confers chemoresistance to anti-estrogen agents through a mechanism involving the inhibition of a pro-apoptotic BH3-only protein, Bik. In the present research the role of plumbagin, a naturally occurring naphthoquinone, in GRP78-associated cell death inhibition was examined. The results demonstrated that plumbagin inhibits GRP78 activity and GRP78 inhibition contributes to plumbagin-mediated cell death induction. Furthermore, Bik upregulation was associated with plumbagin-induced cell death and an increase in plumbagin-mediated Bik induction was observed upon GRP78 downregulation. Plumbagin sensitized estrogen-positive breast cancer cells to tamoxifen and the association of GRP78 inhibition and Bik upregulation in plumbagin-mediated cell sensitization was shown. Collectively, the results of this research suggest that plumbagin inhibits the antiapoptotic activity of GRP78 leading to Bik upregulation and apoptosis induction, which contributes to the sensitization of breast cancer cells to tamoxifen.

Long-term effects of bisphosphonate therapy: perforations, microcracks and mechanical properties

Osteoporosis is characterised by trabecular bone loss resulting from increased osteoclast activation and unbalanced coupling between resorption and formation, which induces a thinning of trabeculae and trabecular perforations. Bisphosphonates are the frontline therapy for osteoporosis, which act by reducing bone remodelling, and are thought to prevent perforations and maintain microstructure. However, bisphosphonates may oversuppress remodelling resulting in accumulation of microcracks. This paper aims to investigate the effect of bisphosphonate treatment on microstructure and mechanical strength. Assessment of microdamage within the trabecular bone core was performed using synchrotron X-ray micro-CT linked to image analysis software. Bone from bisphosphonate-treated fracture patients exhibited fewer perforations but more numerous and larger microcracks than both fracture and non-fracture controls. Furthermore, bisphosphonate-treated bone demonstrated reduced tensile strength and Young's Modulus. These findings suggest that bisphosphonate therapy is effective at reducing perforations but may also cause microcrack accumulation, leading to a loss of microstructural integrity and consequently, reduced mechanical strength.

Risk Factors for Osteoporosis in Postmenopausal Women

INTRODUCTION

Scientific studies show that many factors related to lifestyles affect the reduction of bone mineral density and osteoporosis in postmenopausal women.

GOAL

The goal of this study was to determine whether smoking, drinking coffee and alcohol in menopausal women contribute to the reduction of bone mass and osteoporosis, as well as the impact of physical activity on bone mass.

MATERIAL AND METHODS

The study was carried out as case study and matched controls. The group of cases consisted of 100 females in postmenopausal age, in which by the DEXA method was newly diagnosed osteoporosis at the Clinic of Endocrinology, Diabetes and Metabolic Diseases, University Medical Center of RS during 2015-2016, while the control group consisted of 100 females in a postmenopausal age without diagnosed osteoporosis. The groups were matched by age (±2 years). In order to collect demographic data and information on risk factors for osteoporosis and lifestyle of patients was used the questionnaire Bone Mineral Density Questionnaire- Female of the Irish Association for osteoporosis.

RESULTS

Testing the significance of differences in terms of smoking showed that the studied groups are statistically significantly different in terms of smoking (χ2=24.025, p=0.000). In terms of consumption of coffee, a statistically significant difference was found between the group of cases and control group (χ2=0.615, p=0.735). When observing the obtained information about the consumption of alcohol, we find that this preventable risk factor in the present study did not show as significant for osteoporosis in postmenopausal women (χ2=4.35, p=0.114). Statistical analysis shows that there are significant differences between the group of cases and control group in terms of physical activity (χ2=7.30, p=0.026). Analysis of the data of our study by univariate logistic regressions showed that smoking (p=0.000) was statistically significantly associated with osteoporosis, while physical activity is a protective factor for bone mass (p=0.036). Results of multivariate logistic regression showed that the independent risk factors for osteoporosis in postmenopausal women is smoking (OR=1.665; p=0.006).

CONCLUSION

The results of our study show that smoking is an independent risk factor for osteoporosis in postmenopausal women, and physical activity is a protective factor for bone mass retention. Through education and certain preventive measures should be stressed the importance of these factors on bone health from the earliest period.

Magnesium alloy AZ91 exhibits antimicrobial properties in vitro but not in vivo

Magnesium alloys hold great promise for developing orthopedic implants that are biocompatible, biodegradable, and mechanically similar to bone tissue. This study evaluated the in vitro and in vivo antimicrobial properties of magnesium-9%aluminum-1%zinc (AZ91) and commercially pure titanium (cpTi) against Acinetobacter baumannii (Ab307). The in vitro results showed that as compared to cpTi, incubation with AZ91 significantly reduced both the planktonic (cpTi = 3.45e8, AZ91 = 8.97e7, p < 0.001) colony forming units (CFU) and biofilm-associated (cpTi = 3.89e8, AZ91 = 1.78e7, p = 0.01) CFU of Ab307. However, in vivo results showed no significant differences in the CFU enumerated from the cpTi and AZ91 implants following a 1-week implantation in an established rodent model of Ab307 implant associated infection (cpTi = 5.23e3, AZ91 = 2.46e3, p = 0.29). It is proposed that the in vitro results were associated with an increased pH in the bacterial culture as a result of the AZ91 corrosion process. The robust in vivo buffering capacity likely diminished this corrosion associated pH antimicrobial effect. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 221-227, 2018.

Silver-Containing Hydroxyapatite Coating Reduces Biofilm Formation by Methicillin-Resistant Staphylococcus aureus In Vitro and In Vivo

Biofilm-producing bacteria are the principal causes of infections associated with orthopaedic implants. We previously reported that silver-containing hydroxyapatite (Ag-HA) coatings exhibit high antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA). In the present study, we evaluated the effects of Ag-HA coating of implant surfaces on biofilm formation. Titanium disks (14-mm diameter, 1-mm thickness), one surface of which was coated with HA or 0.5%-3.0% Ag-HA with a thermal spraying technique, were used. In vitro, the disks were inoculated with an MRSA suspension containing 4 × 10⁵ CFU and incubated for 1-2 weeks. In vivo, MRSA-inoculated HA and 3% Ag-HA disks (8.8-10.0 × 10⁸ CFU) were implanted subcutaneously on the back of rats for 1-7 days. All disks were subsequently stained with a biofilm dye and observed under a fluorescence microscope, and biofilm coverage rates (BCRs) were calculated. The BCRs on the Ag-HA coating were significantly lower than those on the HA coating at all time points in vitro (p < 0.05). Similar results were observed in vivo (p < 0.001) without argyria. Ag-HA coating reduced biofilm formation by MRSA in vitro and in vivo; therefore, Ag-HA coating might be effective for reducing implant-associated infections.

Effects of bisphosphonates on mandibular condyle of ovariectomized osteoporotic rats using micro-ct and histomorphometric analysis

OBJECTIVE

To evaluate microarchitectural changes in condylar cartilage and associated subchondral bone after bisphosphonates treatment using an ovariectomized (OVX) osteoporosis rat model.

METHODS

Thirty six-month-old female Sprague-Dawley rats were randomly divided into sham, OVX, and risedronate (RIS)-treated groups. Both OVX and RIS groups received bilateral ovariectomy. OVX group was treated subcutaneously with saline, whereas RIS group received risedronate treatment (2.4 μg/kg) subcutaneously for 3 months. At the end of 3 months, animals were sacrificed and the entire condyles were harvested for micro-CT and histological analyses. Immunohistochemistry (IHC) was performed to assess the expression of type I/II collagen protein by semiquantitative imaging analysis.

RESULTS

Micro-CT analysis showed OVX group had significant condylar subchondral bone loss compared to sham as shown by significant decrease in bone volume fraction (P = 0.028), trabecular thickness (P = 0.041), and significant increase in trabecular spacing (P = 0.003). In RIS group, partial inhibition of OVX-induced bone loss was detected. HE staining showed proliferative layer of condylar cartilage reduced, while hypertrophic chondrocyte layer increased significantly in RIS group compared to sham and OVX groups. IHC showed reduced expression of Col I in both the OVX and RIS groups, whereas expression of Col II was reduced in the OVX group but increased in the RIS group.

CONCLUSION

Our findings suggest that systemic bisphosphonate treatment influences the structure and ossification of condylar cartilage and it has a dual action on condyle in a postmenopausal osteoporosis rat model which raises the concerns for the potential side effects of BPs on condyle to elder patients.

Alcohol Use and Human Immunodeficiency Virus (HIV) Infection: Current Knowledge, Implications, and Future Directions

Alcohol use is common among people living with human immunodeficiency virus (HIV). In this narrative review, we describe literature regarding alcohol's impact on transmission, care, coinfections, and comorbidities that are common among people living with HIV (PLWH), as well as literature regarding interventions to address alcohol use and its influences among PLWH. This narrative review identifies alcohol use as a risk factor for HIV transmission, as well as a factor impacting the clinical manifestations and management of HIV. Alcohol use appears to have additive and potentially synergistic effects on common HIV-related comorbidities. We find that interventions to modify drinking and improve HIV-related risks and outcomes have had limited success to date, and we recommend research in several areas. Consistent with Office of AIDS Research/National Institutes of Health priorities, we suggest research to better understand how and at what levels alcohol influences comorbid conditions among PLWH, to elucidate the mechanisms by which alcohol use is impacting comorbidities, and to understand whether decreases in alcohol use improve HIV-relevant outcomes. This should include studies regarding whether state-of-the-art medications used to treat common coinfections are safe for PLWH who drink alcohol. We recommend that future research among PLWH include validated self-report measures of alcohol use and/or biological measurements, ideally both. Additionally, subgroup variation in associations should be identified to ensure that the risks of particularly vulnerable populations are understood. This body of research should serve as a foundation for a next generation of intervention studies to address alcohol use from transmission to treatment of HIV. Intervention studies should inform implementation efforts to improve provision of alcohol-related interventions and treatments for PLWH in healthcare settings. By making further progress on understanding how alcohol use affects PLWH in the era of HIV as a chronic condition, this research should inform how we can mitigate transmission, achieve viral suppression, and avoid exacerbating common comorbidities of HIV and alcohol use and make progress toward the 90-90-90 goals for engagement in the HIV treatment cascade.

Cytocompatibility with osteogenic cells and enhanced in vivo anti-infection potential of quaternized chitosan-loaded titania nanotubes

Infection is one of the major causes of failure of orthopedic implants. Our previous study demonstrated that nanotube modification of the implant surface, together with nanotubes loaded with quaternized chitosan (hydroxypropyltrimethyl ammonium chloride chitosan, HACC), could effectively inhibit bacterial adherence and biofilm formation in vitro. Therefore, the aim of this study was to further investigate the in vitro cytocompatibility with osteogenic cells and the in vivo anti-infection activity of titanium implants with HACC-loaded nanotubes (NT-H). The titanium implant (Ti), nanotubes without polymer loading (NT), and nanotubes loaded with chitosan (NT-C) were fabricated and served as controls. Firstly, we evaluated the cytocompatibility of these specimens with human bone marrow-derived mesenchymal stem cells in vitro. The observation of cell attachment, proliferation, spreading, and viability in vitro showed that NT-H has improved osteogenic activity compared with Ti and NT-C. A prophylaxis rat model with implantation in the femoral medullary cavity and inoculation with methicillin-resistant Staphylococcus aureus was established and evaluated by radiographical, microbiological, and histopathological assessments. Our in vivo study demonstrated that NT-H coatings exhibited significant anti-infection capability compared with the Ti and NT-C groups. In conclusion, HACC-loaded nanotubes fabricated on a titanium substrate show good compatibility with osteogenic cells and enhanced anti-infection ability in vivo, providing a good foundation for clinical application to combat orthopedic implant-associated infections.

Complex dynamics in an alcoholism model with the impact of Twitter

A novel alcoholism model which involves impact of Twitter is formulated. It is shown that the model has multiple equilibria. Stability of all the equilibria are obtained in terms of the basic reproductive number R₀. Using the center manifold theory, the occurrence of backward and forward bifurcation for a certain defined range of R₀ are established. Furthermore, the existence of Hopf bifurcation is also established by regarding the transmission coefficient β as the bifurcation parameter. Numerical simulations and sensitivity analysis on a few parameters are also carried out. Our results show that Twitter can serve as a good indicator of alcoholism model and affect the spread of the drinking.

Kinsenoside screening with a microfluidic chip attenuates gouty arthritis through inactivating NF-κB signaling in macrophages and protecting endothelial cells

Gouty arthritis is a rheumatic disease that is characterized by the deposition of monosodium urate (MSU) in synovial joints cause by the increased serum hyperuricemia. This study used a three-dimensional (3D) flowing microfluidic chip to screen the effective candidate against MSU-stimulated human umbilical vein endothelial cell (HUVEC) damage, and found kinsenoside (Kin) to be the leading active component of Anoectochilus roxburghi, one of the Chinese medicinal plant widely used in the treatment of gouty arthritis clinically. Cell viability and apoptosis of HUVECs were evaluated, indicating that direct Kin stimulation and conditioned medium (CM) from Kin-treated macrophages both negatively modulated with MSU crystals. Additionally, Kin was capable of attenuating MSU-induced activation of nuclear factor-κB/mitogen-activated protein kinase (NF-κB/MAPK) signaling, targeting IκB kinase-α (IKKα) and IKKβ kinases of macrophages and influencing the expressions of NF-κB downstream cytokines and subsequent HUVEC bioactivity. Inflammasome NLR pyrin domain-containing 3 (NALP3) and toll-like receptor 2 (TLR2) were also inhibited after Kin treatment. Also, Kin downregulated CD14-mediated MSU crystals uptake in macrophages. In vivo study with MSU-injected ankle joints further revealed the significant suppression of inflammatory infiltration and endothelia impairment coupled with alleviation of ankle swelling and nociceptive response via Kin treatments. Taken together, these data implicated that Kin was the most effective candidate from Anoectochilus roxburghi to treat gouty arthritis clinically.

Biodegradable Magnesium (Mg) Implantation Does Not Impose Related Metabolic Disorders in Rats with Chronic Renal Failure

Mg and its alloys have been considered as one of the most promising biodegradable medical devices, but it was still unclear whether hypermagnesemia involved health risks would occur in persons with kidney disease due to their deteriorated kidney function for Mg ions excretion from their body. In this study, we established a chronic renal failure (CRF) model in rats induced by adenine administration prior to Mg implantation, aiming to predict if CRF patients are suitable for the use of Mg implants. The results showed that Mg levels in serum, urine, feces and internal organs had no significant changes after Mg implantation for both normal and CRF rats. Biochemical indices detection and histopathological analysis in kidney, liver and heart tissue confirmed that Mg implants did not induce any extra damage in animals even with renal failure. Our study indicates that Mg based orthopaedic medical device may be considered for use in CRF patients without biosafety concerns.

Systematic Study of Inherent Antibacterial Properties of Magnesium-based Biomaterials

Magnesium-based materials are preferred in temporary orthopedic implants because of their biodegradability, mechanical properties, and intrinsic antibacterial properties. However, the fundamental mechanism of bacteria killing and roles of various factors are not clearly understood. In this study, we performed a systematic study of the antibacterial properties of two common Mg-based materials using a biofilm forming bacterium. Complete annihilation of the initial 3 × 10(4) bacteria is achieved with both materials in 0.1 mL LB medium in 24 h, whereas in the control, they proliferate to 10(10). The bacteria are killed more effectively in the solution than on the surface, and the bacteria killing efficiency depends more on the concentrations of the magnesium ions and hydroxyl ions than the corrosion rate. The killing process is reproduced using formula solutions, and killing is revealed to stem from the synergetic effects of alkalinity and magnesium ions instead of either one of them or Mg(OH)2 precipitate. Reactive oxygen species (ROS) are detected from the bacteria during the killing process but are not likely produced by the redox reaction directly, because they are detected at least 3 h after the reaction has commenced. The average cell size increases during the killing process, suggesting that the bacteria have difficulty with normal division which also contributes to the reduced bacteria population.

Relationship of sarcopenia and body composition with osteoporosis

The purpose of the study is to investigate the relationship between sarcopenia and body composition and osteoporosis in cohorts of three different races with a total of 17,891 subjects. Lean mass and grip strength were positively associated with bone mineral densities (BMDs). Subjects with sarcopenia were two times more likely to have osteoporosis compared with normal subjects.

INTRODUCTION

The relationship between sarcopenia and osteoporosis is not totally clear. First, the present study assessed this relationship by using two different definitions for sarcopenia. Second, we examined the associations of body composition (including muscle mass as a major and important component) and muscle strength on regional and whole-body BMDs.

METHODS

In total, 17,891 subjects of African American, Caucasian, and Chinese ethnicities were analyzed. Sarcopenia was defined by relative appendicular skeletal muscle mass (RASM) cut points and also by the definition of the European Working Group on Sarcopenia in Older People (low RASM plus low muscle function). Multiple regression analyses were conducted to examine the association of fat mass, lean mass (including muscle mass), and grip strength with regional and whole-body BMDs. Multivariate logistic regression analysis was performed to explore the association between sarcopenia and osteopenia/osteoporosis.

RESULTS

BMDs were positively associated with lean mass and negatively associated with fat mass, after controlling for potential confounders. Grip strength was significantly associated with higher BMDs. Each standard deviation (SD) increase in RASM resulted in a ~37 % reduction in risk of osteopenia/osteoporosis (odds ratio (OR) = 0.63; 95 % confidence interval (CI) = 0.59, 0.66). Subjects with sarcopenia defined by RASM were two times more likely to have osteopenia/osteoporosis compared with the normal subjects (OR = 2.04; 95 % CI = 1.61, 2.60). Similarly, subjects with sarcopenia (low muscle mass and low grip strength) were ~1.8 times more likely to have osteopenia/osteoporosis than normal subjects (OR = 1.87; 95 % CI = 1.09, 3.20).

CONCLUSIONS

High lean mass and muscle strength were positively associated with BMDs. Sarcopenia is associated with low BMD and osteoporosis.

Differences between buccal and lingual bone quality and quantity of peri-implant regions

The objective of the current study was to examine whether peri-implant bone tissue properties are different between the buccal and lingual regions treated by growth factors. Four dental implant groups were used: titanium (Ti) implants, alumina-blasted zirconia implants (ATZ-N), alumina-blasted zirconia implants with demineralized bone matrix (DBM) (ATZ-D), and alumina-blasted zirconia implants with rhBMP-2 (ATZ-B). These implants were placed in mandibles of six male dogs. Nanoindentation elastic modulus (E) and plastic hardness (H) were measured for the buccal and lingual bone tissues adjacent and away from the implants at 3 and 6 weeks post-implantation. A total of 2281 indentations were conducted for 48 placed implants. The peri-implant buccal region had less bone quantity resulting from lower height and narrower width of bone tissue than the lingual region. Buccal bone tissues had significant greater mean values of E and H than lingual bone tissues at each distance and healing period (p<0.007). Nearly all implant treatment groups displayed lower mean values of the E at the lingual bone tissues than at the buccal bone tissues (p<0.046) although the difference was not significant for the Ti implant group (p=0.758). The DBM and rhBMP-2 treatments stimulated more peri-implant bone remodeling at the lingual region, producing more immature new bone tissues with lower E than at the buccal region. This finding suggests that the growth factor treatments to the zirconia implant system may help balance the quantity and quality differences between the peri-implant bone tissues.

The relevance of gender in the care of hip fracture patients

As in many conditions, gender interplays with other social structures of inequality to impact upon women's and men's health and healthcare. This narrative review examines knowledge about sex, gender and hip fracture and suggests ways of highlighting the influence of gender in hip fracture healthcare. These will be considered in relation to two areas. Firstly the multifactorial dimension of hip fractures which identifies ethnicity, marital status, lifestyle, co-morbidities, environment in relation to falls and osteoporosis as important factors influencing the experience of hip fracture. Secondly the importance of acknowledging gender as a key element within research and management of care. Implications for practice are that we need a raised awareness of gender when we assess and care for patients, to ask critical questions about the gender bias in the evidence we use and reflect on how services and care practices may be biased towards gendered assumptions.

Effects of risedronate on the morphology and viability of gingiva-derived mesenchymal stem cells

Risedronate has been used for the prevention and treatment of postmenopausal and corticosteroid-induced osteoporosis. The present study was performed to evaluate the effects of risedronate on the morphology and viability of human stem cells derived from the gingiva. Stem cells derived from the gingiva were grown in the presence of risedronate at concentrations that ranged from 1 to 10 µM. The morphology of the cells was viewed under an inverted microscope, and cell proliferation was analyzed with a cell counting kit-8 (CCK-8) on days 2, 4 and 7. The untreated control group showed a spindle-shaped, fibroblast-like morphology. The shapes of the cells treated with 1 and 5 µM risedronate were similar to that of the control group on day 2. However, morphology of the 10 µM group markedly differed from that of the control group. The shapes of the cells in the 1, 5 and 10 µM groups were rounder, and pronounced alterations when compared with the untreated control group were noted in all groups on day 7. The cultures growing in the presence of risedronate showed decreased CCK-8 values on day 7. In conclusion, risedronate produced notable alterations in the morphology of the cells and reduced the viability of gingival mesenchymal stem cells.

Covalently immobilised type I collagen facilitates osteoconduction and osseointegration of titanium coated implants

Background/Objective

Plasma-sprayed titanium coating (TC) with rough surfaces has been successfully applied in hip or knee prostheses. This study aimed to investigate the osteoconduction and osseointegration of Type I collagen covalently immobilised on TC (TC-AAC) compared with those of TC.

Methods

In vitro, the migration of human mesenchymal stem cells (hMSCs) on TC and TC-AAC was observed by scanning electron microscopy and visualised fluorescent live/dead assay. In vivo, a rabbit model with femur condyle defect was employed, and implants of TC and TC-AAC were embedded into the femur condyles.

Results

Collagen immobilised on TC could promote hMSCs' migration into the porous structure of the TC. Micro computed tomography images showed that bone trabeculae were significantly more abundant around TC-AAC implants than around TC implants. Fluorescence micrographs indicated more active new-bone formation around implants in the TC-AAC group than in the TC group. The measurement of bone–implant contact on histological sections indicated significantly greater osteointegration around TC-AAC implants than around TC ones.

Conclusion

Immobilised Type I collagen could improve the osteoconduction and osseointegration of TC implants.

Bacterial inhibition potential of 3D rapid-prototyped magnesium-based porous composite scaffolds--an in vitro efficacy study

Bone infections are common in trauma-induced open fractures with bone defects. Therefore, developing anti-infection scaffolds for repairing bone defects is desirable. This study develoepd novel Mg-based porous composite scaffolds with a basal matrix composed of poly(lactic-co-glycolicacid) (PLGA) and tricalcium phosphate (TCP). A unique low-temperature rapid prototyping technology was used to fabricate the scaffolds, including PLGA/TCP (PT), PLGA/TCP/5%Mg (PT5M), PLGA/TCP/10%Mg (PT10M), and PLGA/TCP/15%Mg (PT15M). The bacterial adhesion and biofilm formation of Staphylococcus aureus were evaluated. The results indicated that the Mg-based scaffolds significantly inhibited bacterial adhesion and biofilm formation compared to PT, and the PT10M and PT15M exhibited significantly stronger anti-biofilm ability than PT5M. In vitro degratation tests revealed that the degradation of the Mg-based scaffolds caused an increase of pH, Mg(2+) concentration and osmolality, and the increased pH may be one of the major contributing factors to the antibacterial function of the Mg-based scaffolds. Additionally, the PT15M exhibited an inhibitory effect on cell adhesion and proliferation of MC3T3-E1 cells. In conclusion, the PLGA/TCP/Mg scaffolds could inhibit bacterial adhesion and biofilm formation, and the PT10M scaffold was considered to be an effective composition with considerable antibacterial ability and good cytocompatibility.

Bone density, microstructure and strength in obese and normal weight men and women in younger and older adulthood

Obesity is associated with greater areal BMD (aBMD) and is considered protective against hip and vertebral fracture. Despite this, there is a higher prevalence of lower leg and proximal humerus fracture in obesity. We aimed to determine if there are site-specific differences in BMD, bone structure, or bone strength between obese and normal-weight adults. We studied 100 individually-matched pairs of normal (body mass index [BMI] 18.5 to 24.9 kg/m2) and obese (BMI >30 kg/m2) men and women, aged 25 to 40 years or 55 to 75 years. We assessed aBMD at the whole body (WB), hip (TH), and lumbar spine (LS) with dual-energy X-ray absorptiometry (DXA), LS trabecular volumetric BMD (Tb.vBMD) by quantitative computed tomography (QCT), and vBMD and microarchitecture and strength at the distal radius and tibia with high-resolution peripheral QCT (HR-pQCT) and micro-finite element analysis. Serum type 1 procollagen N-terminal peptide (P1NP) and collagen type 1 C-telopeptide (CTX) were measured by automated electrochemiluminescent immunoassay (ECLIA). Obese adults had greater WB, LS, and TH aBMD than normal adults. The effect of obesity on LS and WB aBMD was greater in older than younger adults (p < 0.01). Obese adults had greater vBMD than normal adults at the tibia (p < 0.001 both ages) and radius (p < 0.001 older group), thicker cortices, higher cortical BMD and tissue mineral density, lower cortical porosity, higher trabecular BMD, and higher trabecular number than normal adults. There was no difference in bone size between obese and normal adults. Obese adults had greater estimated failure load at the radius (p < 0.05) and tibia (p < 0.01). Differences in HR-pQCT measurements between obese and normal adults were seen more consistently in the older than the younger group. Bone turnover markers were lower in obese than in normal adults. Greater BMD in obesity is not an artifact of DXA measurement. Obese adults have higher BMD, thicker and denser cortices, and higher trabecular number than normal adults. Greater differences between obese and normal adults in the older group suggest that obesity may protect against age-related bone loss and may increase peak bone mass.

Enhanced antibacterial properties, biocompatibility, and corrosion resistance of degradable Mg-Nd-Zn-Zr alloy

Magnesium (Mg), a potential biodegradable material, has recently received increasing attention due to its unique antibacterial property. However, rapid corrosion in the physiological environment and potential toxicity limit clinical applications. In order to improve the corrosion resistance meanwhile not compromise the antibacterial activity, a novel Mg alloy, Mg-Nd-Zn-Zr (Hereafter, denoted as JDBM), is fabricated by alloying with neodymium (Nd), zinc (Zn), zirconium (Zr). pH value, Mg ion concentration, corrosion rate and electrochemical test show that the corrosion resistance of JDBM is enhanced. A systematic investigation of the in vitro and in vivo antibacterial capability of JDBM is performed. The results of microbiological counting, CLSM, SEM in vitro, and microbiological cultures, histopathology in vivo consistently show JDBM enhanced the antibacterial activity. In addition, the significantly improved cytocompatibility is observed from JDBM. The results suggest that JDBM effectively enhances the corrosion resistance, biocompatibility and antimicrobial properties of Mg by alloying with the proper amount of Zn, Zr and Nd.

Changes in the mechanical properties and composition of bone during microdamage repair

Under normal conditions, loading activities result in microdamage in the living skeleton, which is repaired by bone remodeling. However, microdamage accumulation can affect the mechanical properties of bone and increase the risk of fracture. This study aimed to determine the effect of microdamage on the mechanical properties and composition of bone. Fourteen male goats aged 28 months were used in the present study. Cortical bone screws were placed in the tibiae to induce microdamage around the implant. The goats were euthanized, and 3 bone segments with the screws in each goat were removed at 0 days, 21 days, 4 months, and 8 months after implantation. The bone segments were used for observing microdamage and bone remodeling, as well as nanoindentation and bone composition, separately. Two regions were measured: the first region (R1), located 1.5 mm from the interface between the screw hole and bone; and the second region (R2), located>1.5 mm from the bone-screw interface. Both diffuse and linear microdamage decreased significantly with increasing time after surgery, with the diffuse microdamage disappearing after 8 months. Thus, screw implantation results in increased bone remodeling either in the proximal or distal cortical bone, which repairs the microdamage. Moreover, bone hardness and elastic modulus decreased with microdamage repair, especially in the proximal bone tissue. Bone composition changed greatly during the production and repair of microdamage, especially for the C (Carbon) and Ca (Calcium) in the R1 region. In conclusion, the presence of mechanical microdamage accelerates bone remodeling either in the proximal or distal cortical bone. The bone hardness and elastic modulus decreased with microdamage repair, with the micromechanical properties being restored on complete repair of the microdamage. Changes in bone composition may contribute to changes in bone mechanical properties.

Increased bone remodelling around titanium implants coated with chondroitin sulfate in ovariectomized rats

Coating titanium implants with artificial extracellular matrices based on collagen and chondroitin sulfate (CS) has been shown to enhance bone remodelling and de novo bone formation in vivo. The aim of this study was to evaluate the effect of estrogen deficiency and hormone replacement therapy (HRT) on the osseointegration of CS-modified Ti implants. 30 adult female, ovariectomized Wistar rats were fed either with an ethinyl-estradiol-rich diet (E) to simulate a clinical relevant HRT or with a genistein-rich diet (G) to test an alternative therapy based on nutritionally relevant phytoestrogens. Controls (C) received an estrogen-free diet. Uncoated titanium pins (Ti) or pins coated with type-I collagen and CS (Ti/CS) were inserted 8weeks after ovarectomy into the tibia. Specimens were retrieved 28days after implantation. Both the amount of newly formed bone and the affinity index (P<0.05) were moderately higher around Ti/CS implants as compared to uncoated Ti. The highest values were measured in the G-Ti/CS and E-Ti/CS groups, the lowest values for the E-Ti and G-Ti controls. Quantitative synchrotron radiation micro-computed tomography (SRμCT) revealed the highest increase in total bone formation around G-Ti/CS as compared to C-Ti (P<0.01). The effects with respect to direct bone apposition were less pronounced with SRμCT. Using scanning nanoindentation, both the indentation modulus and the hardness of the newly formed bone were highest in the E-Ti/CS, G-Ti/CS and G-Ti groups as compared to C-Ti (P<0.05). Coatings with collagen and CS appear to improve both the quantity and quality of bone formed around Ti implants in ovarectomized rats. A simultaneous ethinyl estradiol- and genistein-rich diet seems to enhance these effects.

Entangled titanium fibre balls combined with nano strontium hydroxyapatite in repairing bone defects

OBJECTIVE

To investigate the effect of entangled titanium fibre balls (ETFBs) combined with nano strontium hydroxyapatite (nano-Sr-HAP) on the repair of bone defects in vivo.

MATERIALS AND METHODS

Twenty-four 6-month-old, specific pathogen-free, male Sprague-Dawley rats were used. Drill defects were created in bilateral femoral condyles. ETFBs combined with nano-Sr-HAP were selected randomly from 72 samples and implanted into the femoral bone defects of left legs, which served as the experimental group, while ETFBs without nano-Sr-HAP were implanted into right legs for comparison. The bone defects on both sides were X-rayed. The anteroposterior positions and histological procedures and evaluations of each sample were performed at 1, 2, 4 and 8 weeks post-surgery.

RESULTS

Histological results showed that the ETBs allowed new bone to grow within their structure. Additionally, an increase in new bone was seen on the nano-Sr-HAP side compared to the control side. The results of histomorphometric analysis confirmed that the new bone formation on the left side gradually increased with time. There was a statistical increase in new bone at 2, 4 and 8 weeks, and the differences between the two sides were statistically significant at weeks 4 and 8 (p < 0.05 for all comparisons).

CONCLUSION

The results showed that ETFBs possess a unique 3-dimensional interconnective porous structure and have excellent biocompatibility, cell affinity and osteoconductivity, which makes them useful as scaffold materials for repairing bone defects. On the other hand, nano-Sr-HAP improved the bone defect-repairing capacity of the ETFBs, which showed osteoinductive properties.

Repair of microdamage in osteonal cortical bone adjacent to bone screw

Up to date, little is known about the repair mode of microdamage in osteonal cortical bone resulting from bone screw implantation. In this study, self-tapping titanium cortical bone screws were inserted into the tibial diaphyses of 24 adult male rabbits. The animals were sacrificed at 1 day, 2 weeks, 1 month and 2 months after surgery. Histomorphometric measurement and confocal microscopy were performed on basic fuchsin stained bone sections to examine the morphological characteristics of microdamage, bone resorption activity and spatial relationship between microdamage and bone resorption. Diffuse and linear cracks were coexisted in peri-screw bone. Intracortical bone resorption was significantly increased 2 weeks after screw installation and reach to the maximum at 1 month. There was no significant difference in bone resorption between 1-month and 2-months groups. Microdamage was significantly decreased within 1 month after surgery. Bone resorption was predisposed to occur in the region of <100 µm from the bone-screw interface, where had extensive diffuse damage mixed with linear cracks. Different patterns of resorption cavities appeared in peri-screw bone. These data suggest that 1) the complex microdamage composed of diffuse damage and linear cracks is a strong stimulator for initiating targeted bone remodeling; 2) bone resorption activities taking place on the surfaces of differently oriented Haversian and Volkmann canals work in a team for the repair of extensive microdamage; 3) targeted bone remodeling is a short-term reaction to microdamage and thereby it may not be able to remove all microdamage resulting from bone screw insertion.

Lean mass as a predictor of bone density and microarchitecture in adult obese individuals with metabolic syndrome

The effects of obesity and metabolic syndrome (MS) on bone health are controversial. Furthermore, the relationship between body composition and bone quality has not yet been determined in this context. The aim of this study was to investigate the correlations between body composition and bone mineral density (BMD) and bone microstructure in obese individuals with MS. This cross-sectional study assessed 50 obese individuals with MS with respect to their body composition and BMD, both assessed using dual X-ray absorptiometry, and bone microarchitecture, assessed by high-resolution peripheral quantitative computed tomography (HR-pQCT) of the distal tibia and radius. Several HR-pQCT measurements exhibited statistically significant correlations with lean mass. Lean mass was positively correlated with parameters of better bone quality (r: 0.316-0.470) and negatively correlated with parameters of greater bone fragility (r: -0.460 to -0.310). Positive correlations were also observed between lean mass and BMD of the total femur and radius 33%. Fat mass was not significantly correlated with BMD or any HR-pQCT measurements. Our data suggest that lean mass might be a predictor of bone health in obese individuals with MS.

Importance of fat mass and lean mass on bone health in men: the Fourth Korean National Health and Nutrition Examination Survey (KNHANES IV)

This study was aimed to evaluate the association between body composition and bone health. High lean mass and low fat mass have protective effects on bone health in men representative of the national population.

INTRODUCTION

The aim of this study was to evaluate the association between body composition (fat mass and lean mass) and bone health in men.

METHODS

Totally, 3,945 men (age ≥ 20 years) from the fourth Korean National Health and Nutrition Examination Survey of 2008-2009 (KNHANES IV) were included in this study. Body composition and bone mineral densities (BMDs) were measured using dual energy X-ray absorptiometry. Osteopenia or osteoporosis was identified on the basis of the World Health Organization T-score criteria.

RESULTS

Multiple linear regression analyses showed that BMDs of the whole body, femoral neck, and lumbar spine were positively associated with lean mass and negatively associated with fat mass, after controlling for body weight and other potential confounders. Subjects with more fat mass or less lean mass, categorized according to quartiles of fat mass and lean mass, had higher odds of having osteopenia or osteoporosis, as shown by multivariable logistic regression (P for trend <0.001).

CONCLUSIONS

High lean mass and low fat mass have protective effects on bone health in a population of Korean adult men. Fat mass appears to exert a detrimental effect on BMD, in contrast with the positive weight-bearing effect. Body composition seems to be a more important determinant for bone health than simple body weight.

Diagnostic measures for sarcopenia and bone mineral density

SUMMARY

Currently used diagnostic measures for sarcopenia utilize different measures of muscle mass, muscle strength, and physical performance. These diagnostic measures associate differently to bone mineral density (BMD), as an example of muscle-related clinical outcome. These differences should be taken into account when studying sarcopenia.

INTRODUCTION

Diagnostic measures for sarcopenia utilize different measures of muscle mass, muscle strength, and physical performance. To understand differences between these measures, we determined the association with respect to whole body BMD, as an example of muscle-related clinical outcome.

METHODS

In the European cross-sectional study MYOAGE, 178 young (18-30 years) and 274 healthy old participants (69-81 years) were recruited. Body composition and BMD were evaluated using dual-energy X-ray densitometry. Diagnostic measures for sarcopenia were composed of lean mass as percentage of body mass, appendicular lean mass (ALM) as percentage of body mass, ALM divided by height squared (ALM/height(2)), knee extension torque, grip strength, walking speed, and Timed Up and Go test (TUG). Linear regression models were stratified for sex and age and adjusted for age and country, and body composition in separate models.

RESULTS

Lean mass and ALM/height(2) were positively associated with BMD (P < 0.001). Significance remained in all sex and age subgroups after further adjustment for fat mass, except in old women. Lean mass percentage and ALM percentage were inversely associated with BMD in old women (P < 0.001). These inverse associations disappeared after adjustment for body mass. Knee extension torque and handgrip strength were positively associated with BMD in all subgroups (P < 0.01), except in old women. Walking speed and TUG were not related to BMD.

CONCLUSIONS

The associations between diagnostic measures of sarcopenia and BMD as an example of muscle-related outcome vary widely. Differences between diagnostic measures should be taken into account when studying sarcopenia.

A lower value for quantitative ultrasound at radius is an additional indicator of metabolic syndrome and cardiovascular disease risk

BACKGROUND

The relationships between quantitative ultrasound (QUS) values, metabolic syndrome (MetS) and cardiovascular disease (CVD) risk are unclear. Objective The objective was to determine the relationships between QUS and MetS as well as CVD risk.

DESIGN

This was a cross-sectional study conducted in Shanghai, China.

PATIENTS

One-thousand four hundred and thirty-nine Chinese women and men with or without MetS were studied.

MEASUREMENTS

Speed of sound (SOS) at radius, phalanx and tibia and their relationships with MetS and Framingham's 10-year cardiovascular disease risk scores were investigated.

RESULTS

Premenopausal women with MetS had significant lower SOS at radius than those without MetS after adjusting for age, BMI and fat mass percentage (P = 0·02). The radius SOS was negatively associated with waist circumference (r = -0·109, P = 0·025), waist-to-hip ratio (r = -0·124, P = 0·01) and 2 h postprandial glucose level (r = -0·125, P = 0·012) in premenopausal women. Waist circumference, waist-to-hip ratio and 2 h postprandial glucose level increased with the decreasing tertiles of radius SOS after adjustment of age (P = 0·003, 0·002 and 0·008, respectively). The CVD risk increased with decreasing tertiles of radius SOS in postmenopausal women even after the adjustment of age, years since menopause, MetS components, smoking and alcohol habits (P < 0·001), but not in premenopausal women and men.

CONCLUSIONS

Lower radius SOS is associated with greater risks of MetS and CVD in premenopausal and postmenopausal women, respectively. The QUS value derived from non-weight-bearing site, such as radius, may represent an additional indicator of MetS and CVD risk in women.

Effect of fat mass and lean mass on bone mineral density in postmenopausal and perimenopausal Thai women

BACKGROUND

The purpose of this study was to investigate the association between fat mass, lean mass, and bone mineral density (BMD) in postmenopausal and perimenopausal Thai women.

METHODS

A cross-sectional study was conducted in 1579 healthy Thai women aged 40-90 years. Total body, lumbar spine, total femur, and femoral neck BMD and body composition were measured by dual x-ray absorptiometry. To evaluate the associations between fat mass and lean mass and various measures of BMD, multivariable linear regression models were used to estimate the regression coefficients for fat mass and lean mass, first in separate equations and then with both fat mass and lean mass in the same equation.

RESULTS

Among the study population, 1448 subjects (91.7%) were postmenopausal and 131 (8.3%) were perimenopausal. In postmenopausal women, after controlling for age, height, and duration of menopause, both fat mass and lean mass were positively correlated with BMD when they were analyzed independently of each other. When included in the same equation, both fat mass and lean mass continued to show a positive effect, but lean mass had a significantly greater impact on BMD than fat mass at all regions except for total body. Lean mass but not fat mass had a positive effect on BMD at all skeletal sites except the lumbar spine, after controlling for age and height in perimenopausal women.

CONCLUSION

Lean mass had a significant beneficial effect on BMD in both postmenopausal and perimenopausal women and can be considered as one of the determinants of bone mass. The effect of the fat mass was related to menopausal status, but only demonstrated a positive impact in perimenopausal women.

In vitro and in vivo studies on nanocrystalline Ti fabricated by equal channel angular pressing with microcrystalline CP Ti as control

Bulk nanocrystalline Ti bars (Grade 4, Φ4 × 3000 mm(3)) were massively fabricated by equal channel angular pressing (ECAP) via follow-up conform scheme with the microcrystalline CP Ti as raw material. Homogeneous nanostructured crystals with the average grain size of 250 nm were identified for the ECAPed Ti, with extremely high tensile/fatigue strength (around 1240/620 MPa) and adorable elongation (more than 5%). Pronounced formation of bonelike apatite for the nanocrystalline Ti group after 14 days static immersion in simulated body fluids (SBF) reveals the prospective in vitro bioactive capability of fast calcification, whereas an estimated 17% increment in protein adsorption represents good bioaffinity of nanocrystalline Ti. The documentation onto the whole life circle of osteoblast cell lines (MG63) revealed the strong interactions and superior cellular functionalization when they are co-incubated with bulk nanocrystalline Ti sample. Moreover, thread-structured specimens were designed and implanted into the tibia of Beagles dogs till 12 weeks to study the in vivo responses between bone and metallic implant made of bulk nanocrystalline Ti, with the microcrystalline Ti as control. For the implanted nanostructured Ti group, neoformed bone around the implants underwent the whole-stage transformation proceeding from originally osteons or immature woven bone to mature lamellar bone (skeletonic trabecular), even with the remodeling being finished till 12 weeks. The phenomenal osseointegration of direct implant-bone contact can be revealed from the group of the ECAPed Ti without fibrous tissue encapsulation in the gap between the implant and autogenous bone.