A High-Avidity, Thermostable, and Low-Cost Synthetic Capture for Ultrasensitive Detection and Quantification of Viral Antigens and Aerosols.

Lateral flow assays (LFAs) are currently the most popular point-of-care diagnostics, rapidly transforming disease diagnosis from expensive doctor checkups and laboratory-based tests to potential on-the-shelf commodities. Yet, their sensitive element, a monoclonal antibody, is expensive to formulate, and their long-term storage depends on refrigeration technology that cannot be met in resource-limited areas. In this work, LCB1 affibodies (antibody mimetic miniproteins) were conjugated to bovine serum albumin (BSA) to afford a high-avidity synthetic capture (LCB1-BSA) capable of detecting the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein and virus like particles (VLPs). Substituting the monoclonal antibody 2B04 for LCB1-BSA (stable up to 60 °C) significantly improved the thermal stability, shelf life, and affordability of plasmonic-fluor-based LFAs (p-LFAs). Furthermore, this substitution significantly improved the sensitivity of p-LFAs toward the spike protein and VLPs with precise quantitative ability over 2 and 3 orders of magnitude, respectively. LCB1-BSA sensors could detect VLPs at 100-fold lower concentrations, and this improvement, combined with their robust nature, enabled us to develop an aerosol sampling technology to detect aerosolized viral particles. Synthetic captures like LCB1-BSA can increase the ultrasensitivity, availability, sustainability, and long-term accuracy of LFAs while also decreasing their manufacturing costs.

Macromolecular condensation organizes nucleolar sub-phases to set up a pH gradient.

Nucleoli are multicomponent condensates defined by coexisting sub-phases. We identified distinct intrinsically disordered regions (IDRs), including acidic (D/E) tracts and K-blocks interspersed by E-rich regions, as defining features of nucleolar proteins. We show that the localization preferences of nucleolar proteins are determined by their IDRs and the types of RNA or DNA binding domains they encompass. In vitro reconstitutions and studies in cells showed how condensation, which combines binding and complex coacervation of nucleolar components, contributes to nucleolar organization. D/E tracts of nucleolar proteins contribute to lowering the pH of co-condensates formed with nucleolar RNAs in vitro. In cells, this sets up a pH gradient between nucleoli and the nucleoplasm. By contrast, juxta-nucleolar bodies, which have different macromolecular compositions, featuring protein IDRs with very different charge profiles, have pH values that are equivalent to or higher than the nucleoplasm. Our findings show that distinct compositional specificities generate distinct physicochemical properties for condensates.

Emergent microenvironments of nucleoli.

In higher eukaryotes, the nucleolus harbors at least three sub-phases that facilitate multiple functionalities including ribosome biogenesis. The three prominent coexisting sub-phases are the fibrillar center (FC), the dense fibrillar component (DFC), and the granular component (GC). Here, we review recent efforts in profiling sub-phase compositions that shed light on the types of physicochemical properties that emerge from compositional biases and territorial organization of specific types of macromolecules. We highlight roles played by molecular grammars which refers to protein sequence features including the substrate binding domains, the sequence features of intrinsically disordered regions, and the multivalence of these distinct types of domains / regions. We introduce the concept of a barcode of emergent physicochemical properties of nucleoli. Although our knowledge of the full barcode remains incomplete, we hope that the concept prompts investigations into undiscovered emergent properties and engenders an appreciation for how and why unique microenvironments control biochemical reactions.

Primary Arthrodesis versus Open Reduction and Internal Fixation for Lisfranc Joint Fracture-Dislocations in Adults: A Systematic Review.

BACKGROUND: The Lisfranc joint is an intricate podiatric medical structure that when injured can prove difficult to treat. No consensus has been established on optimal surgical management for this injury. It is widely debated whether open reduction and internal fixation or primary arthrodesis provides better outcomes for patients. Although literature has been published on this subject, no generalized guidelines have been created. The goal of this study was to analyze high-level meta-analyses to draw conclusions about surgical interventions for Lisfranc joint injuries. METHODS: A literature review was conducted to analyze outcomes of meta-analyses from January 1, 2016, to August 31, 2021. Only high-level evidence that reported at least one of the following outcomes was included: American Orthopaedic Foot and Ankle Society scale score, visual analog scale score, total complication rate, hardware removal rate, revision surgery rate, and secondary procedure rate. RESULTS: Six articles met the inclusion and exclusion criteria and were then analyzed. For all of the outcome measures, primary arthrodesis was equal or superior to open reduction and internal fixation. CONCLUSIONS: We recommend primary arthrodesis over open reduction and internal fixation for adult Lisfranc injuries.

The ATR inhibitor ceralasertib potentiates cancer checkpoint immunotherapy by regulating the tumor microenvironment.

The Ataxia telangiectasia and Rad3-related (ATR) inhibitor ceralasertib in combination with the PD-L1 antibody durvalumab demonstrated encouraging clinical benefit in melanoma and lung cancer patients who progressed on immunotherapy. Here we show that modelling of intermittent ceralasertib treatment in mouse tumor models reveals CD8+ T-cell dependent antitumor activity, which is separate from the effects on tumor cells. Ceralasertib suppresses proliferating CD8+ T-cells on treatment which is rapidly reversed off-treatment. Ceralasertib causes up-regulation of type I interferon (IFNI) pathway in cancer patients and in tumor-bearing mice. IFNI is experimentally found to be a major mediator of antitumor activity of ceralasertib in combination with PD-L1 antibody. Improvement of T-cell function after ceralasertib treatment is linked to changes in myeloid cells in the tumor microenvironment. IFNI also promotes anti-proliferative effects of ceralasertib on tumor cells. Here, we report that broad immunomodulatory changes following intermittent ATR inhibition underpins the clinical therapeutic benefit and indicates its wider impact on antitumor immunity.

Comparison of Loss of Bone Height Following Total Ankle Arthroplasty Versus Tibiotalocalcaneal Arthrodesis.

Ankle arthrodesis and total ankle arthroplasty are both well-accepted surgical treatment options for end-stage ankle arthrosis. However, total ankle arthroplasty has gained popularity as the survivability of implants is improving. It is understood that there is loss of bone height following tibiotalocalcaneal arthrodesis, but to our knowledge, this has not been investigated in the setting of total ankle arthroplasty. A retrospective radiographic review was conducted over a 5-year period. We investigated all patients who underwent a tibiotalocalcaneal arthrodesis or total ankle arthroplasty for treatment of ankle arthritis by a single fellowship-trained orthopedic surgeon. The anterior and posterior height measurements were measured on preoperative and postoperative lateral radiographs. Differences between preoperative and postoperative heights were analyzed through a series of analyses of covariance. One hundred and thirty-three patients and 143 operative extremities were included: 71 operative extremities in the tibiotalocalcaneal arthrodesis group (mean age 55.5 ± 13.3 years, BMI 32.2 ± 7.9) and 72 in the total ankle arthroplasty group (mean age 65.4 ± 9.5 years, BMI 30.7 ± 6.4). Statistical analysis demonstrated a loss of height in the tibiotalocalcaneal arthrodesis group, and an increased anterior and posterior height in the total ankle arthroplasty group. However, when comparing the arthroplasty group and arthrodesis group only the anterior height measurement reached statistical significance when stratified by gender (p < .001). The potential change in height is an important factor to consider during surgical planning as a limb length discrepancy may result.

How effective are exercises delivered digitally (requiring internet), amongst patients with hip or knee osteoarthritis? A systematic review and meta-analysis.

OBJECTIVE: The aim of this systematic review and meta-analysis is to describe the effect of digitally delivered exercise on pain, physical function and quality of life (QoL) for people with knee or hip osteoarthritis (OA). METHODS: Articles were eligible for inclusion if they were of a randomized control trial that evaluated the prescription of digitally delivered exercise (requiring the internet) in people with symptomatic primary hip and/or knee OA. Risk of bias was assessed using the Physiotherapy Evidence Database scale, and levels of evidence were assessed according to Grading of Recommendations Assessment, Development and Evaluation. RESULTS: Digitally delivered exercise was delivered via synchronous and asynchronous methods (or a combination of both). Digitally delivered exercise was superior to education only for pain and physical function, with high-quality evidence for quality-of-life outcomes in the long-term (standardized mean difference -0.35, 95% confidence interval -0.59 to -0.12, P = 0.003) in people with knee OA. Furthermore, there was very low to low-quality evidence that digitally delivered exercise was comparable to face-to-face delivery in the short and long-term for people with hip or knee OA and comparable in the medium-term for people with knee OA only. DISCUSSION: The review demonstrated very low to low-quality evidence that digitally delivered exercise was comparable to face-to-face delivery for pain, function and QoL. In the absence of higher-level evidence, we would provisionally recommend that healthcare providers offer the choice of face-to-face or digitally delivered exercise intervention for people with hip or knee OA. Further work is required to understand these programs' reach, access, uptake and implementation across diverse population groups.

Sex-related differences in gait characteristics and their associations with symptoms in individuals with patellofemoral osteoarthritis.

BACKGROUND: Patellofemoral osteoarthritis (OA) is an important subgroup of knee OA. However, the influence of sex on gait characteristics in patients with patellofemoral OA is unknown. RESEARCH QUESTION: Compare gait characteristics in females and males with patellofemoral OA and investigate their associations with patellofemoral joint-related symptoms and limitations. METHODS: Mixed effects polynomial regression models compared knee flexion-extension and adduction moments, knee flexion angles, and vertical ground reaction forces over 100% of stance between 26 females and 22 males with patellofemoral OA, with and without adjustment for walking speed and body mass. Multivariable linear regression models were then used to investigate the associations of gait characteristics with symptoms and limitations measured with the Knee injury and Osteoarthritis Outcome Score Patellofemoral Pain and Osteoarthritis (KOOS-PF) Subscale. Models included a sex-by-gait interaction term, and if significant, separate models were built for females and males. RESULTS: While controlling for walking speed and body mass, females had lower knee flexion moment (6-19% and 97-100% of stance), knee extension moment (45-86% of stance), knee adduction moment (3-37% and 69-99% of stance), vertical ground reaction force (1-97% of stance) and knee flexion angle (90-100% of stance) compared with males, when fitted over 100% of stance. Lower cadence, lower knee flexion angular impulse, and higher peak knee flexion angle were associated with worse KOOS-PF scores. Associations were not modified by sex. SIGNIFICANCE: There are distinct sex-based differences in gait characteristics throughout stance with patellofemoral OA when adjusting for body mass and walking speed. Lower cadence and knee flexion angular impulse, and higher peak knee flexion angle were associated with more extreme patellofemoral joint-related symptoms and limitations.

The association between lateral hip muscle size/intramuscular fat infiltration and hip strength in active young adults with long standing hip/groin pain.

OBJECTIVES: To investigate associations between lateral hip muscle size/intramuscular fat infiltration (MFI) and hip strength in active young adults with longstanding hip/groin pain. DESIGN: Cross-sectional study. SETTING: University/Clinical. PARTICIPANTS: Sub-elite soccer and Australian Football players (n = 180; 37 female) with long standing hip/groin pain. MAIN OUTCOME MEASURES: Muscle size (volume) and MFI of gluteus maximus, medius, and minimis, and tensor fascia latae (TFL) were assessed using magnetic resonance imaging. Isometric hip strength was measured with handheld dynamometry. Associations between muscle size/MFI were assessed using linear regression models, adjusted for body mass index and age, with sex-specific interactions. RESULTS: Positive associations were identified between lateral hip muscle volume and hip muscle strength, particularly for gluteus maximus and gluteus minimus volume. For all muscles, hip abduction was associated with an increase in strength by up to 0.69 N (R2 ranging from 0.29 to 0.39). These relationships were consistent across sexes with no sex interactions observed. No associations were found between MFI and strength measures. CONCLUSION: Greater lateral hip muscle volumes are associated with greater hip strength in active young adults with long standing hip/groin pain, irrespective of sex. Gluteus maximus and minimus volume showed the most consistent relationships with hip strength across multiple directions.

Co-development and evaluation of the Musculoskeletal Telehealth Toolkit for physiotherapists.

INTRODUCTION: In-person physiotherapy services are not readily available to all individuals with musculoskeletal conditions, especially those in rural regions or with time-intensive responsibilities. The COVID-19 pandemic highlighted that telehealth may facilitate access to, and continuity of care, yet many physiotherapists lack telehealth confidence and training. This project co-developed and evaluated a web-based professional development toolkit supporting physiotherapists to provide telehealth services for musculoskeletal conditions. METHODS: A mixed-methods exploratory sequential design applied modified experience-based co-design methods (physiotherapists [n = 13], clinic administrators [n = 2], and people with musculoskeletal conditions [n = 7]) to develop an evidence-informed toolkit. Semi-structured workshops were conducted, recorded, transcribed, and thematically analysed, refining the toolkit prototype. Subsequently, the toolkit was promoted via webinars and social media. The usability of the toolkit was examined with pre-post surveys examining changes in confidence, knowledge, and perceived telehealth competence (19 statements modelled from the theoretical domains framework) between toolkit users (>30 min) and non-users (0 min) using chi-squared tests for independence. Website analytics were summarised. RESULTS: Twenty-two participants engaged in co-design workshops. Feedback led to the inclusion of more patient-facing resources, increased assessment-related visual content, streamlined toolkit organisation, and simplified, downloadable infographics. Three hundred and twenty-nine physiotherapists from 21 countries completed the baseline survey, with 172 (52%) completing the 3-month survey. Toolkit users had greater improvement in knowledge, confidence, and competence than non-users in 42% of statements. Seventy-two percentage of toolkit users said it changed their practice, and 95% would recommend the toolkit to colleagues. During the evaluation period, the toolkit received 5486 total views. DISCUSSION: The co-designed web-based Musculoskeletal Telehealth Toolkit is a professional development resource that may increase physiotherapist's confidence, knowledge, and competence in telehealth.

Dynamical control enables the formation of demixed biomolecular condensates.

Cellular matter can be organized into compositionally distinct biomolecular condensates. For example, in Ashbya gossypii, the RNA-binding protein Whi3 forms distinct condensates with different RNA molecules. Using criteria derived from a physical framework for explaining how compositionally distinct condensates can form spontaneously via thermodynamic considerations, we find that condensates in vitro form mainly via heterotypic interactions in binary mixtures of Whi3 and RNA. However, within these condensates, RNA molecules become dynamically arrested. As a result, in ternary systems, simultaneous additions of Whi3 and pairs of distinct RNA molecules lead to well-mixed condensates, whereas delayed addition of an RNA component results in compositional distinctness. Therefore, compositional identities of condensates can be achieved via dynamical control, being driven, at least partially, by the dynamical arrest of RNA molecules. Finally, we show that synchronizing the production of different RNAs leads to more well-mixed, as opposed to compositionally distinct condensates in vivo.

Football Players With Hip Dysplasia: The Relationship Between Muscle Strength, Functional Performance, Self-reported Sport and Recreation, Cartilage Defects, and Sex. A Cross-sectional Study.

OBJECTIVE: In symptomatic football players with hip dysplasia, we aimed to explore the relationships between self-reported sport and recreation ability and (1) hip muscle strength, (2) functional performance, and investigate if these relationships were modified by sex or cartilage defects. METHODS: In this cross-sectional study, football players (n = 50) with longstanding (>6 months) hip and/or groin pain, a positive flexion/adduction/internal rotation test, and a lateral-center-edge angle <25° were included. Hip muscle strength and functional performance were assessed. Self-reported sport and recreation ability was quantified using the sports and recreational subscales from the International Hip Outcome Tool-33 (iHOT-Sport) and the Copenhagen Hip and Groin Outcome Score (HAGOS-Sport). Relationships were evaluated using regression models with sex and cartilage defects as potential effect modifiers. RESULTS: There was a positive linear relationship between the one-leg-rise test and the iHOT-Sport subscale (ß = 0.61; 95% CI: 0.09, 1.14). A polynomial (concave) relationship was found between peak eccentric adduction strength and the HAGOS-Sport subscale (ß = -30.88; 95% CI: -57.78, -3.99). Cartilage defects modified the relationship between peak isometric adduction strength and HAGOS-Sport, with those with cartilage defects having a polynomial (convex) relationship (ß = 36.59; 95% CI: 12.74, 60.45), and those without cartilage defects having no relationship. CONCLUSION: One-leg-rise performance and adduction strength were associated with self-reported sport and recreation ability, indicating a possible relationship between physical function, hip joint structure, and sport and recreation ability in football players with hip dysplasia. J Orthop Sports Phys Ther 2023;53(10):1-8. Epub: 8 September 2023. doi:10.2519/jospt.2023.12026.

Improved pearl millet genomes representing the global heterotic pool offer a framework for molecular breeding applications.

High-quality reference genome assemblies, representative of global heterotic patterns, offer an ideal platform to accurately characterize and utilize genetic variation in the primary gene pool of hybrid crops. Here we report three platinum grade de-novo, near gap-free, chromosome-level reference genome assemblies from the active breeding germplasm in pearl millet with a high degree of contiguity, completeness, and accuracy. An improved Tift genome (Tift23D2B1-P1-P5) assembly has a contig N50 ~ 7,000-fold (126 Mb) compared to the previous version and better alignment in centromeric regions. Comparative genome analyses of these three lines clearly demonstrate a high level of collinearity and multiple structural variations, including inversions greater than 1 Mb. Differential genes in improved Tift genome are enriched for serine O-acetyltransferase and glycerol-3-phosphate metabolic process which play an important role in improving the nutritional quality of seed protein and disease resistance in plants, respectively. Multiple marker-trait associations are identified for a range of agronomic traits, including grain yield through genome-wide association study. Improved genome assemblies and marker resources developed in this study provide a comprehensive framework/platform for future applications such as marker-assisted selection of mono/oligogenic traits as well as whole-genome prediction and haplotype-based breeding of complex traits.

Mechanosensitive ion channels MSL8, MSL9, and MSL10 have environmentally sensitive intrinsically disordered regions with distinct biophysical characteristics in vitro.

Intrinsically disordered protein regions (IDRs) are highly dynamic sequences that rapidly sample a collection of conformations over time. In the past several decades, IDRs have emerged as a major component of many proteomes, comprising ~30% of all eukaryotic protein sequences. Proteins with IDRs function in a wide range of biological pathways and are notably enriched in signaling cascades that respond to environmental stresses. Here, we identify and characterize intrinsic disorder in the soluble cytoplasmic N-terminal domains of MSL8, MSL9, and MSL10, three members of the MscS-like (MSL) family of mechanosensitive ion channels. In plants, MSL channels are proposed to mediate cell and organelle osmotic homeostasis. Bioinformatic tools unanimously predicted that the cytosolic N-termini of MSL channels are intrinsically disordered. We examined the N-terminus of MSL10 (MSL10N) as an exemplar of these IDRs and circular dichroism spectroscopy confirms its disorder. MSL10N adopted a predominately helical structure when exposed to the helix-inducing compound trifluoroethanol (TFE). Furthermore, in the presence of molecular crowding agents, MSL10N underwent structural changes and exhibited alterations to its homotypic interaction favorability. Lastly, interrogations of collective behavior via in vitro imaging of condensates indicated that MSL8N, MSL9N, and MSL10N have sharply differing propensities for self-assembly into condensates, both inherently and in response to salt, temperature, and molecular crowding. Taken together, these data establish the N-termini of MSL channels as intrinsically disordered regions with distinct biophysical properties and the potential to respond uniquely to changes in their physiochemical environment.

Does hip muscle strength and functional performance differ between football players with and without hip dysplasia?

OBJECTIVE: To compare hip muscle strength and functional performance in football players with and without hip dysplasia and investigate if the relationships were modified by sex. DESIGN: Cross-sectional study. METHODS: This study compared football players with hip dysplasia (HD group) and without hip dysplasia (control group). Hip muscle strength (Nm/kg) and functional task performance were assessed in both groups. Linear regression with generalized estimating equations were used to assess differences between groups. Sex was assessed as a potential effect modifier. RESULTS: 101 football players were included (HD group, n = 50, control group, n = 51). There was no difference in hip muscle strength or functional performance between the HD group and the control group. Results ranged from hip extension strength (Estimate -0.13.95%CI: 0.29 to 0.02, P = 0.087) to hip external rotation strength (Estimate 0.00.95%CI: 0.05 to 0.05, P = 0.918). No relationships were modified by sex or age. CONCLUSIONS: Similar levels of hip muscle strength and functional performance were found in active football players with and without hip dysplasia. These findings differ from other studies. This may be due to our cohort having less advanced hip dysplasia than the surgical populations that have been previously investigated, or due to a beneficial effect of football participation on muscle strength and functional performance in people with hip dysplasia.

Are hip biomechanics during running associated with symptom severity or cam morphology size in male football players with FAI syndrome?

BACKGROUND: Femoroacetabular impingement (FAI) syndrome is considered a motion-related condition. Little is known about the influence of symptom severity and cam morphology on hip biomechanics for individuals with FAI syndrome. RESEARCH QUESTION: Are hip biomechanics during running associated with symptom severity or cam morphology size in male football players with FAI syndrome? METHODS: Forty-nine male, sub-elite football (soccer or Australian football) players (mean age= 26 years) with FAI syndrome completed the International Hip Outcome Tool-33 (iHOT-33) and Copenhagen Hip and Groin Outcome Score (HAGOS) and underwent radiographic evaluation. Biomechanical data were collected during overground running (3-3.5 m∙s-1) using three-dimensional motion capture technology and an embedded force plate. Various discrete hip angles and impulses of joint moments were analysed during the stance phase. Linear regression models investigated associations between running biomechanics data (dependent variables) and iHOT-33 and HAGOS scores and cam morphology size (independent variables). RESULTS: Hip joint angles during running were not associated with symptom severity in football players with FAI syndrome. A positive association was found between the impulse of the hip external rotation moment and HAGOS-Sport scores, such that a smaller impulse magnitude occurred with a lower HAGOS-Sport score (0.026 *10-2 [95%CI <0.001 *10-2 to 0.051 *10-2], P = 0.048). Larger cam morphology was associated with a greater peak hip adduction angle at midstance (0.073 [95%CI 0.002-0.145], P = 0.045). SIGNIFICANCE: Hip biomechanics during running did not display strong associations with symptom severity or cam morphology size in male football players with FAI syndrome who were still participating in training and match play. Future studies might consider investigating associations during tasks that utilise end range hip joint motion or require greater muscle forces.

Hip muscle activity in people with hip-related pain compared to asymptomatic controls: A systematic review.

BACKGROUND: Altered hip and thigh muscle activity have been observed across a spectrum of articular hip pathologies, including hip osteoarthritis, femoroacetabular impingement syndrome, and labral pathology. No systematic reviews have examined muscle activity associated with hip pathology and hip-related pain across the life span. A greater understanding of impairments in hip and thigh muscle activity during functional tasks may assist in the development of targeted treatment strategies. METHODS: We conducted a systematic review using the PRISMA guidelines. A literature search was performed in five databases (MEDLINE, CINAHL, EMBASE, Sports Discuss, and PsychINFO). Studies were included that (i) investigated people with hip-related pain (femoroacetabular impingement syndrome, labral tears) or hip osteoarthritis; and (ii) reported on muscle activity using electromyography of hip and thigh muscles during functional tasks such as walking, stepping, squatting, or lunging. Two independent reviewers performed data extraction and assessed risk of bias using a modified version of the Downs and Black checklist. RESULTS: Non-pooled data demonstrated a limited level of evidence. Overall, differences in muscle activity appeared to be more prevalent in people with more advanced hip pathology. CONCLUSIONS: We found that impairments in muscle activity in those with intra-articular hip pathology measured using electromyography were variable but appeared to be greater in severe hip pathology (e.g., hip OA).

Preventing unrecognized deterioration & improving outcomes of critically ill patients using the National Early Warning Score 2 in a high dependency unit in Bangladesh: A quality improvement project.

This Quality Improvement Project (QIP) aimed to assess the acceptability and utility of the National Early Warning Score 2 (NEWS2) in a Bangladeshi level-2 care setting. All nurses and physicians were trained on NEWS2 scores and a proper response before starting the QIP. Utilization of NEWS2 and patient outcome were documented and analyzed. Acceptability was acknowledged by increase in utilization, and utility by reduction in unrecognized deterioration of patients. The modified NEWS2 was well adopted and utilized by the nursing staff. There was a statistically significant reduction in unrecognized deterioration leading to cardiac arrest and the need for transfer to the Intensive Care Unit after implementation of NEWS2. With adequate training, motivation and appropriate modification, NEWS2 can become a well-accepted, widely adopted and realistic bedside monitoring tool in resource-limited settings like Bangladesh.

A cross-sectional study of mental health and well-being among youth in military-connected families. / Étude transversale sur la santé mentale et le bien-être de jeunes de familles liées au milieu militaire.

INTRODUCTION: The study objective was to compare the mental health and risk-taking behaviour of Canadian youth in military-connected families to those not in military-connected families in a contemporary sample. We hypothesized that youth in military-connected families have worse mental health, lower life satisfaction and greater engagement in risk-taking behaviours than those not in military-connected families. METHODS: This cross-sectional study used 2017/18 Health Behaviour in School-aged Children in Canada survey data, a representative sample of youth attending Grades 6 to 10. Questionnaires collected information on parental service and six indicators of mental health, life satisfaction and risk-taking behaviour. Multivariable Poisson regression models with robust error variance were implemented, applying survey weights and accounting for clustering by school. RESULTS: This sample included 16 737 students; 9.5% reported that a parent and/or guardian served in the Canadian military. After adjusting for grade, sex and family affluence, youth with a family connection to the military were 28% more likely to report low well-being (95% CI: 1.17-1.40), 32% more likely to report persistent feelings of hopelessness (1.22-1.43), 22% more likely to report emotional problems (1.13-1.32), 42% more likely to report low life satisfaction (1.27-1.59) and 37% more likely to report frequent engagement in overt risk-taking (1.21-1.55). CONCLUSION: Youth in military-connected families reported worse mental health and more risk-taking behaviours than youth not in military-connected families. The results suggest a need for additional mental health and well-being supports for youth in Canadian military-connected families and longitudinal research to understand underlying determinants that contribute to these differences.