Signal peptide exchange alters HIV-1 envelope antigenicity and immunogenicity.

Introduction: HIV-1 envelope (Env) is the key target for antibodies (Abs) against the virus and thus an important HIV-1 vaccine component. Env is synthesized from a gp160 precursor with a signal peptide (SP) at its N-terminus. This study investigated the influence of the SP on Env antigenicity and immunogenicity. Methods: Env proteins from two HIV-1 isolates, AA05 and AC02, were analyzed as gp120 and gp160 in their native wild-type (WT) forms and as chimeras with swapped SPs (AA05-02 and AC02-05). The WT and chimeric Env were assessed for antigenicity and glycosylation using monoclonal antibodies (mAbs) and glycan probes. Immunogenicity was tested in mice using three vaccine types: gp120 protein, gp120 DNA+gp120 protein, and gp120 DNA+gp160 DNA. Results: The recombinant AC02 gp120 protein was antigenically superior to AA05 as indicated by higher reactivity with most mAbs tested. When SPs were swapped, the antigenicity of the chimeric gp120s (AA05-02 and AC02-05) resembled that of the gp120s from which the SPs were derived; AA05-02 was similar to AC02 and vice versa. Glycan probe reactivity followed a similar pattern: AA05-02 and AC02 showed similar affinity to high-mannose specific mAbs and lectins. Interestingly, the antigenicity of gp160s showed an opposite pattern; membrane-bound gp160 expressed with the AA05 SP (AA05 and AC02-05) showed greater mAb binding than gp160 with the AC02 SP (AC02 and AA05-02). Mice immunized with gp120 protein showed that AA05-02 induced stronger cross-reactive binding Ab responses than AA05 WT, and AC02 elicited stronger responses than AC02-05, indicating AC02 SP enhanced gp120 immunogenicity. However, when DNA vaccines were included (gp120 DNA+gp120 protein and gp120 DNA+gp160 DNA), the use of heterologous SPs diminished the immunogenicity of the WT immunogens. Among the three vaccine regimens tested, only gp120 DNA+gp160 DNA immunization elicited low-level Tier 2 neutralizing Abs, with AA05 WT inducing Abs with greater neutralization capabilities than AA05-02. Conclusion: These data demonstrate that the SP can significantly impact the antigenicity and immunogenicity of HIV-1 Env proteins. Hence, while SP swapping is a common practice in constructing Env immunogens, this study highlights the importance of careful consideration of the effects of replacing native SPs on the immunogenicity of Env vaccines.

Biocontrol Potential of Bacillus strains against soybean cyst nematode (Heterodera glycines) and for promotion of soybean growth.

The soybean cyst nematode (SCN, Heterodera glycines) is the most yield-limiting pathogen in soybeans worldwide. Using chemical pesticides to control this disease is harmful to human and environment. It is urgent to develop environment-friendly nematicides. The aim of this study was to discover novel biocontrol agents on H. glycines control and soybean growth under greenhouse and field conditions Eight Bacillus strains were isolated from soil rhizosphere soils and the stability and efficiency of H. glycines was assessed in greenhouse and field experiments in 2021 and 2022. In particular, the Ba2-6 strain had the highest potential, because it was a biocontrol agent against H. glycines shown to cause 93.85% juvenile mortality. Furthermore, strains Ba 1-7, Ba2-4, and Ba2-6 effectively reduced the number of females and improved the soybean seed number per plant. Based on their morphological, physiological, biochemical and molecular (16 S rRNA) characteristics, the three strains were identified as B. aryabhattai (Ba1-7), B. megatherium (Ba2-4), and B. halotolerans (Ba2-6). The ability of Ba2-6 to induce systemic resistance to H. glycines in soybeans was investigated by the split-root system and real-time quantitative PCR experiments. The results indicated that the Ba2-6 strain induced systemic resistance to suppress the penetration of H. glycines, and enhanced gene expression of PR1, PR3a, PR5, and NPR1-2, involved in the salicylic acid and jasmonic acid pathways. The study suggests that the strains of B. aryabhattai Ba1-7, B. megatherium Ba2-4, and B. halotolerans Ba2-6 can be considered as effective biocontrol agents to control H. glycines. Further, B. halotolerans Ba2-6 not only promotes soybean growth but also enhances resistance to H. glycines by regulating defense-related gene expression and inducing systemic resistance in soybean.

Investigating the NH4+ Preintercalation and Surface Coordination Effects on MnO2 for Ammonium-Ion Supercapacitors.

Ion preintercalation is an effective method for fine-tuning the electrochemical characteristics of electrode materials, thereby enhancing the performance of aqueous ammonium-ion hybrid supercapacitors (A-HSCs). However, much of the current research on ion preintercalation lacks controllability, and the underlying mechanisms remain unclear. In this study, we employ a two-step electrochemical activation approach, involving galvanostatic charge-discharge and cyclic voltammetry, to modulate the preintercalation of NH4+ in MnO2. An in-depth analysis of the electrochemical activation mechanism is presented. This two-step electrochemical activation approach endows the final MnO2/AC electrode with a high capacitance of 917.4 F g-1, approximately 2.4 times higher than that of original MnO2. Furthermore, the MnO2/AC electrode retains approximately 93.4% of its capacitance after 10 000 cycles at a current density of 25 mA cm-2. Additionally, aqueous A-HSC, comprising MnO2/AC and P-MoO3, achieves a maximum energy density of 87.6 Wh kg-1. This study offers novel insights into the controllable ion preintercalation approach via electrochemical activation.

Establishing an Evaluation Indicator System for User Satisfaction With Hypertension Management Apps: Combining User-Generated Content and Analytic Hierarchy Process.

BACKGROUND: Hypertension management apps (HMAs) can be effective in controlling blood pressure, but their actual impact is often suboptimal. Establishing a user satisfaction evaluation indicator system for HMAs can assist app developers in enhancing app design and functionality, while also helping users identify apps that best meet their needs. This approach aims to improve the overall effectiveness of app usage. OBJECTIVE: This study aims to systematically collect data on HMAs and their user reviews in the United States and China. It analyzes app usage patterns and functional characteristics, identifies factors influencing user satisfaction from existing research, and develops a satisfaction evaluation indicator system to provide more accurate recommendations for improving user satisfaction. METHODS: We conducted a descriptive statistical analysis to assess the development status of HMAs in both countries and applied the task-technology fit model to evaluate whether the app functionalities align with business needs. We separately summarized the factors influencing user satisfaction in both countries from previous research, utilized the analytic hierarchy process to develop an evaluation indicator system for HMA user satisfaction, and calculated satisfaction levels. Based on these findings, we propose improvements to enhance app functionality and user satisfaction. RESULTS: In terms of current development status, there were fewer HMAs and user reviews in China compared with the United States. Regarding app functional availability, fewer than 5% (4/91) of the apps achieved a demand fulfillment rate exceeding 80% (8/10). Overall, user satisfaction in both countries was low. CONCLUSIONS: In the United States, user satisfaction was lowest for advertising distribution, data synchronization, and reliability. By contrast, Chinese apps need improvements in cost efficiency and compatibility.

Effect of thermal pretreatments on the quality attributes and irradiation markers of sesame oil extracted from sesame seeds without and with gamma irradiation.

This study comparatively studied the effects of three thermal pretreatment methods, i.e., wet-heat (WT), roasting (RT) and microwave (MT), on the quality attributes and irradiation markers of sesame oil obtained from sesame seeds without and with gamma irradiation. Results showed that gamma irradiation had negligible effect on the quality of sesame seeds and their extracted oils. The effects of thermal pretreatments on irradiated and non-irradiated sesame seeds and their oils were similar, little synergistic effects were observed. The RT-treated oils had more carotenoids, chlorophyll, total phenols, tocopherols, and heterocyclic volatiles content, as well as longer oxidation induction time, but darker color compared with their WT- and MT-treated counterparts. All oil samples had identical FTIR spectra. Eight radiolytic hydrocarbons were identified in the irradiated sesame oils. Thermal pretreatments reduced the content of radiolytic hydrocarbons, but did not significantly change their composition. Our study helps to identify products from irradiated sesame seeds.

Rational Design of a Novel 6H-Benzo[c]chromen Series as Selective PI3Kα Inhibitors.

The phosphoinositide 3-kinase (PI3K)/mammalian target of rapamycin (mTOR) signaling pathway is a frequently dysregulated pathway in human cancer, and PI3Kα is one of the most frequently mutated kinases in human cancer. A selective PI3Kα inhibitor may provide the opportunity to spare patients the side effects associated with broader inhibition of the class I PI3K family. Here, we describe our efforts to discover a novel series of selective PI3Kα inhibitors using structure-based drug design and molecular docking to inform the design of 6H-benzo[c]chromen inhibitors. XJTU-L453 (21) was identified with PI3Kα inhibitory potency and unique selectivity over other PI3K isoforms and all other kinases tested. Further evaluation of pharmacokinetic properties and in vivo efficacy led to the identification of the preclinical potential of XJTU-L453 (21).

Stimuli-Responsive Nanomaterials for Tumor Immunotherapy.

Cancer remains a significant challenge in extending human life expectancy in the 21st century, with staggering numbers projected by the International Agency for Research on Cancer for upcoming years. While conventional cancer therapies exist, their limitations, in terms of efficacy and side effects, demand the development of novel treatments that selectively target cancer cells. Tumor immunotherapy has emerged as a promising approach, but low response rates and immune-related side effects present significant clinical challenges. Researchers have begun combining immunotherapy with nanomaterials to optimize tumor-killing effects. Stimuli-responsive nanomaterials have become a focus of cancer immunotherapy research due to their unique properties. These nanomaterials target specific signals in the tumor microenvironment, such as pH or temperature changes, to precisely deliver therapeutic agents and minimize damage to healthy tissue. This article reviews the recent developments and clinical applications of endogenous and exogenous stimuli-responsive nanomaterials for tumor immunotherapy, analyzing the advantages and limitations of these materials and highlighting their potential for enhancing the immune response to cancer and improving patient outcomes.

HIV-1 interaction with an O-glycan-specific bacterial lectin enhances virus infectivity and resistance to neutralizing antibodies.

Bacteria dysbiosis and its accompanying inflammation or compromised mucosal integrity is associated with an increased risk of HIV-1 transmission. However, HIV-1 may also bind bacteria or bacterial products to impact infectivity and transmissibility. This study evaluated HIV-1 interactions with bacteria through glycan-binding lectins. The Streptococcal Siglec-like lectin SLBR-N, a part of the fimbriae shrouding the bacteria surface that recognizes α2,3 sialyated O-linked glycans, was noted for its ability to enhance HIV-1 infectivity in the context of cell-free infection and cell-to-cell transfer. Enhancing effects were recapitulated with O-glycan-binding plant lectins, signifying the importance of O-glycans. N-glycan-binding bacterial lectins FimH and Msl had no effect. SLBR-N was demonstrated to capture and transfer infectious HIV-1 virions, bind to O-glycans on HIV-1 Env, and increase HIV-1 resistance to neutralizing antibodies targeting different regions of Env. This study highlights the potential contribution of O-glycan-binding lectins from commensal bacteria at the mucosa in promoting HIV-1 infection.

Prescribed Fixed-Time Control for Constrained Uncertain Nonlinear Cyber-Physical Systems Against Deception Attacks.

In this note, a novel prescribed fixed-time adaptive tracking control scheme is developed to cope with the fixed-time tracking control issue for a category of constrained MIMO nonlinear cyber-physical systems (CPSs) with exogenous perturbations, which suffer from deception attacks started in controller-actuator (C-A) channel. Distinguished from the conservative dynamic surface control (DSC) schemes with a linear filter, a novel nonlinear filter is designed in our strategy, which can tackle the intrinsic issue of explosion of computational complexity and promote the system performance. Besides, a new barrier Lyapunov function (BLF) is designed to ulteriorly enhance the tracking performance on the basis of the prescribed performance function (PPF) approach. Prominently, the proposed control strategy could accommodate the exogenous interferences and deception attacks simultaneously. Furthermore, we have substantiated that the developed approach can not only make certain that all the tracking errors of the resulting closed-loop system, including output tracking errors and virtual tracking errors, enter a prespecified small region near equilibrium point with fixed-time convergence rate, but also guarantee them obey the corresponding constraints throughout the entire control operation, where the regulation time and the tracking accuracy level keep prior known and could be prespecified arbitrarily. Finally, the validity and effectiveness of the proposed control scheme are illustrated through a representative application instance.

Why robot-assisted total hip arthroplasty aborted: Chinese experience of four hundred and twenty nine consecutive cases.

PURPOSE: Robot-assisted total hip arthroplasty (RA-THA) helps with precise orientation of the prosthesis, but some RA-THA procedures are aborted intraoperatively and are converted to manual total hip arthroplasty (THA). This study aimed to analyse why RA-THA is sometimes aborted intraoperatively and to make recommendations accordingly. METHODS: A total of 429 consecutive Mako THA cases in our prospective database from August 2018 to June 2021 were included in our study. All robotic procedures aborted intraoperatively for any reason were recorded. The patients' demographics, diagnoses, and surgeons' information were included in the statistical analysis to pinpoint the risk factors for intraoperative robot to manual conversion. RESULTS: Intraoperative RA-THA abortions occurred in 17 cases (3.96%) and the patients had to be converted to manual THA. The adverse events leading to intraoperative abortions included pelvic array loosening or malposition (5, 1.17%), inaccurate bone mapping or construction (6, 1.40%), inaccurate initial registration (4, 0.93%), and other reasons (2, 0.47%). CONCLUSION: Robot-related adverse events could be found in all perioperative steps of RA-THA, and some of these events might result in intraoperative abortion. Complex hip disease was a statistically significant factor for an increased risk of intraoperative abortion of RA-THA. Standardized surgical procedures and preoperative assessments can be helpful in reducing the rate of RA-THA abortions.

REDD1 knockdown ameliorates endothelial cell senescence through repressing TXNIP-mediated oxidative stress.

Endothelial cell senescence characterized by reactive oxygen species (ROS) accumulation and chronic inflammation is widely recognized as a key contributor to atherosclerosis (AS). Regulated in development and DNA damage response 1 (REDD1), a conserved stress-response protein that regulates ROS production, is involved in the pathogenesis of various age-related diseases. However, the role of REDD1 in endothelial cell senescence is still unclear. Here, we screened REDD1 as a differentially expressed senescence-related gene in the AS progression using bioinformatics methods, and validated the upregulation of REDD1 expression in AS plaques, senescent endothelial cells, and aging aorta by constructing AS mice, D-galactose (DG)-induced senescent endothelial cells and DG-induced accelerated aging mice, respectively. siRNA against REDD1 could improve DG-induced premature senescence of endothelial cells and inhibit ROS accumulation, similar to antioxidant N-Acetylcysteine (NAC) treatment. Meanwhile, NAC reduced the upregulation of REDD1 induced by DG, supporting the positive feedback loop between REDD1 and ROS contributes to endothelial cell senescence. Mechanistically, the regulatory effect of REDD1 on ROS might be related to the TXNIP-REDD1 interaction in DG-induced endothelial cell senescence. Collectively, experiments above provide evidence that REDD1 participates in endothelial cell senescence through repressing TXNIP-mediated oxidative stress, which may be involved in the progression of atherosclerosis.

Anti-tau single domain antibodies clear pathological tau and attenuate its toxicity and related functional defects.

Tauopathies are a group of neurodegenerative diseases characterized by the presence of tau inclusions. We have developed over fifty anti-tau single-domain antibodies (sdAbs) derived from phage display libraries of a llama immunized with recombinant and pathological tau immunogens. We examined the therapeutic potential of four of these sdAbs in a Drosophila tauopathy model following their transgenic expression either in all neurons or neuronal subtypes. Three of these sdAbs showed therapeutic potential in various assays, effectively clearing pathological tau and attenuating or preventing tau-induced phenotypes that typically manifest as defects in neuronal axonal transport, neurodegeneration, functional impairments, and shortened lifespan. Of these three, one sdAb was superior in every assay, which may at least in part be attributed to its tau-binding epitope. These findings support its development as a gene therapy for tauopathies.

Deterministic processes dominate microbial assembly mechanisms in the gut microbiota of cold-water fish between summer and winter.

Exploring the effects of seasonal variation on the gut microbiota of cold-water fish plays an important role in understanding the relationship between seasonal variation and cold-water fish. Gut samples of cold-water fish and environmental samples were collected during summer and winter from the lower reaches of the Yalong River. The results of the 16S rRNA sequencing showed that significant differences were identified in the composition and diversity of gut bacteria of cold-water fish. Co-occurrence network complexity of the gut bacteria of cold-water fish was higher in summer compared to winter (Sum: nodes: 256; edges: 20,450; Win: nodes: 580; edges: 16,725). Furthermore, from summer to winter, the contribution of sediment bacteria (Sum: 5.3%; Win: 23.7%) decreased in the gut bacteria of cold-water fish, while the contribution of water bacteria (Sum: 0%; Win: 27.7%) increased. The normalized stochastic ratio (NST) and infer community assembly mechanisms by phylogenetic bin-based null model analysis (iCAMP) showed that deterministic processes played a more important role than stochastic processes in the microbial assembly mechanism of gut bacteria of cold-water fish. From summer to winter, the contribution of deterministic processes to gut bacteria community assembly mechanisms decreased, while the contribution of stochastic processes increased. Overall, these results demonstrated that seasonal variation influenced the gut bacteria of cold-water fish and served as a potential reference for future research to understand the adaptation of fish to varying environments.

Sorption characteristics of phosphorus on marine sediments in the presence of black carbon derived from fly ash.

The sorption behavior of phosphorus on marine sediments in the presence of black carbon derived from fly ash (FC) was studied. For both the FC and sediment samples, the kinetic curves could be described by a two-compartment first order equation, and the isotherms fit the Freundlich and Langmuir models well. The high specific surface area with abundant acidic functional groups of FC promoted the sorption and make this process more irreversible. The effects were more significant with higher amount of FC added. After sorption, more significant increase in Ex-P, Fe/Al-P and CaP was found in the sediment with FC added, while the organic groups in FC rarely react with phosphorus to form OP. The pH of medium influenced the sorption character, and FC promoted the process significantly at pH < pHPZNPC. The sorption was endothermic with an increase in randomness. The presence of FC had little effects on the thermodynamic parameters.

Association between the serum uric acid levels and prostate cancer: evidence from National Health and Nutrition Examination Survey (NHANES) 1999-2010.

Background: Uric acid may play a critical role in protection against cancer by the suppression of inflammation. The association between serum uric acid (SUA) levels and prostate cancer risk is debatable yet has received little attention in the American population. Therefore, we used data from the National Health and Nutrition Examination Survey (NHANES) to determine their correlation. Methods: Using information from NHANES 1999-2010, a total of 62,160 individuals from the general population were included in this cross-sectional study. Additionally, a number of covariates were acquired. Prostate cancer was used to divide the participants into two groups: prostate cancer group (n=315) and non-prostate cancer group (n=7,545). A weighted adjusted logistic regression analysis was conducted to examine the potential correlation between SUA and prostate cancer. Results: Our study comprised a total of 7,860 participants. After full adjustment for confounders, SUA was not significantly associated with prostate cancer [odds ratio (OR) 0.91, 95% confidence interval (CI): 0.82-1.00, P=0.058]. In participants aged 60 years and above (≥60 years), a higher SUA was significantly associated with a lower risk of prostate cancer (OR 0.88, 95% CI: 0.80-0.96, P=0.003). However, among those younger than 60 years (<60 years), there was no association between SUA and prostate cancer risk (OR 1.29, 95% CI: 0.69-2.42, P=0.42). In addition, in the subgroup analysis stratified by body mass index, hypertension and diabetes, there was no significant correlation between SUA and prostate cancer. Conclusions: SUA is negatively associated with the risk of prostate cancer in older men, especially for those 60 years of age and beyond.

DANCR maintained colon epithelial homeostasis by regulating the TNFα/NF-κB pathway.

Epithelial homeostasis is fundamental for the physiological functions of colon tissue. Dysregulation of colon epithelial structure leads to abnormal immune responses and diseases such as inflammatory bowel disease. In this work we found long non-coding RNA DANCR was a novel regulator to colon epithelial homeostasis. Silencing DANCR resulted in decreased expression of epithelial barrier proteins and enhanced susceptibility to TNFα stimulation, which was accompanied by hyperactivation of the NF-κB pathway. Mechanistical studies revealed DANCR modulated the expression of a protein methyltransferase SET7 to suppress responses to TNFα, as well as the activity of NF-κB pathway. In summary, DANCR regulated colon epithelial homeostasis through modulating the TNFα/NF-κB axis. These findings cast light on the discovery of novel regulators to colon epithelial homeostasis and added new evidence to the physiological functions of DANCR.

Single-domain antibody-based protein degrader for synucleinopathies.

Synucleinopathies are a group of neurodegenerative diseases characterized by the accumulation of α-synuclein (α-syn) in the brain, leading to motor and neuropsychiatric symptoms. Currently, there are no known cures for synucleinopathies, and treatments mainly focus on symptom management. In this study, we developed a single-domain antibody (sdAb)-based protein degrader with features designed to enhance proteasomal degradation of α-syn. This sdAb derivative targets both α-syn and Cereblon (CRBN), a substrate-receptor for the E3-ubiquitin ligase CRL4CRBN, and thereby induces α-syn ubiquitination and proteasomal degradation. Our results indicate that this therapeutic candidate enhances proteasomal degradation of α-syn, in addition to the endogenous lysosomal degradation machinery. By promoting proteasomal degradation of α-syn, we improved clearance of α-syn in primary culture and mouse models of synucleinopathy. These findings indicate that our sdAb-based protein degrader is a promising therapeutic candidate for synucleinopathies. Considering that only a small percentage of antibodies enter the brain, more potent sdAbs with greater brain entry than whole antibodies could enhance clinical benefits of antibody-based therapies.

Human CD4-binding site antibody elicited by polyvalent DNA prime-protein boost vaccine neutralizes cross-clade tier-2-HIV strains.

The vaccine elicitation of HIV tier-2-neutralization antibodies has been a challenge. Here, we report the isolation and characterization of a CD4-binding site (CD4bs) specific monoclonal antibody, HmAb64, from a human volunteer immunized with a polyvalent DNA prime-protein boost HIV vaccine. HmAb64 is derived from heavy chain variable germline gene IGHV1-18 and light chain germline gene IGKV1-39. It has a third heavy chain complementarity-determining region (CDR H3) of 15 amino acids. On a cross-clade panel of 208 HIV-1 pseudo-virus strains, HmAb64 neutralized 20 (10%), including tier-2 strains from clades B, BC, C, and G. The cryo-EM structure of the antigen-binding fragment of HmAb64 in complex with a CNE40 SOSIP trimer revealed details of its recognition; HmAb64 uses both heavy and light CDR3s to recognize the CD4-binding loop, a critical component of the CD4bs. This study demonstrates that a gp120-based vaccine can elicit antibodies capable of tier 2-HIV neutralization.

Surface-Initiated Polymerization with an Initiator Gradient: A Monte Carlo Simulation.

Due to the difficulty of accurately characterizing properties such as the molecular weight (Mn) and grafting density (σ) of gradient brushes (GBs), these properties are traditionally assumed to be uniform in space to simplify analysis. Applying a stochastic reaction model (SRM) developed for heterogeneous polymerizations, we explored surface-initiated polymerizations (SIPs) with initiator gradients in lattice Monte Carlo simulations to examine this assumption. An initial exploration of SIPs with 'homogeneously' distributed initiators revealed that increasing σ slows down the polymerization process, resulting in polymers with lower molecular weight and larger dispersity (D) for a given reaction time. In SIPs with an initiator gradient, we observed that the properties of the polymers are position-dependent, with lower Mn and larger D in regions of higher σ, indicating the non-uniform properties of polymers in GBs. The results reveal a significant deviation in the scaling behavior of brush height with σ compared to experimental data and theoretical predictions, and this deviation is attributed to the non-uniform Mn and D.

Bone fracture is associated with incident myocardial infarction in long-term follow-up.

BACKGROUND: The association between bone fracture and cardiovascular diseases is examined in this study. While basic research has established a connection between fractures and heart attacks through the linkage between bones and arteries, population studies have not provided clear evidence. The aim of the present study is to investigate the association between bone fracture and the occurrence of myocardial infarction in a natural population during long-term follow-up. METHODS: A total of 13,196 adult participants with bone fracture history at baseline from the China Health and Nutrition Survey (CHNS) prospective cohort were included in this study. Baseline investigation was performed in 1997-2009 and the outcome was followed up till 2015. Hazard ratios (HRs) and their corresponding 95% confidence intervals (CIs) were calculated using Cox proportional hazards models. RESULTS: From 1997 to 2015, a total of 329 incident myocardial infarction cases were identified. In univariate and multivariate Cox regression analysis, a history of bone fracture was associated with an increased risk of myocardial infarction incidence in the total population (for the crude model: HR = 2.56, 95% CI 1.83-3.53, P < 0.001; for the multivariate model: HR = 1.43, 95% CI 1.02-1.99, P = 0.036). In the stratified analysis, bone fracture was not associated with an increased risk of incident myocardial infarction in subjects with age < 50 years (HR = 0.71, 95% CI 0.34-1.47, P = 0.356), but significantly associated with an increased risk of incident myocardial infarction in subjects with age ≥ 50 years (HR = 1.80, 95% CI 1.23-2.63, P = 0.003). CONCLUSIONS: It is suggested by the present study that bone fracture may be associated with an increased risk of incident myocardial infarction in the elderly population during long-term follow-up.