The American Naturalist

Major surface antigens in many pathogens are encoded by rapidly diversifying multigene families, generating fitness variation through antigenic and functional differences. These variations align with the niche and absolute fitness axes of Modern Coexistence Theory (MCT). Yet, how such gene families evolve along these axes under competition for hosts and across transmission gradients remains poorly understood, as prior MCT studies have not explicitly accounted for evolutionary dynamics in high dimensions. We use a stochastic computational model of Plasmodium falciparum transmission to examine how transmission intensity and selection shape var multigene family evolution and composition within parasite genomes. Results show that selection alone cannot maintain the observed stable ratio of two gene groups within parasite genomes, indicating that group-based classifications do not clearly reflect transmission strategy or virulence. When a trade-off exists between diversification rates and absolute fitness, strong immune selection under high transmission favors fast-recombining genes while attenuating functional selection on R0-associated traits. In general, stronger immune selection increases the invasion probability of novel antigens and the niche differentiation among parasite genomes, while reducing the variance in gene-level transmissibility and expression duration, and therefore R0. This outcome, combining enhanced niche differentiation and reduced absolute fitness variation, departs from MCT predictions.

Cell-cell communication (CCC) orchestrates coordinated cellular behaviors underlying development, regeneration, and disease. Recent advances in spatiotemporal transcriptomics enable simultaneous measurement of gene expression across spatial contexts and developmental progression. However, most existing CCC inference methods rely heavily on curated ligand-receptor (LR) databases and implicitly assume steady-state gene expression, limiting applicability to understudied species and hindering robust inference of dynamic signaling cascades. Here, we introduce SpaTRACE, a transformer-based temporal-causal framework for pathway-free CCC inference from developmental spatial transcriptomics data. SpaTRACE trains a temporal causal attention-based transformer along pseudotime-sampled trajectories to model time-lagged dependencies across spatially resolved cell populations. Attention weights enable de novo reconstruction of intercellular signaling interactions (ligand-target gene; LR-TG) and intracellular gene regulatory relationships (transcription factor-target gene; TF-TG), which are integrated to infer dynamic CCC networks without reliance on predefined LR databases. Across synthetic datasets, SpaTRACE accurately recovers LR-TG interactions, TF-TG regulation, and correct LR pairings, outperforming existing CCC methods, particularly under noisy pathway settings. Applied to mouse midbrain development and axolotl brain regeneration, SpaTRACE recovers canonical signaling modules, identifies stage-specific transitions, and uncovers previously under-characterized interactions. Together, SpaTRACE provides a general and statistically powerful framework for dissecting dynamic intercellular communication and regulatory programs from spatiotemporal transcriptomics data. Code is available at https://github.com/VariaanZhou/SpaTRACE.

In humans, germline mutation rates are three- to four-fold higher in males than females, for largely unknown reasons. We investigated whether transcription, a well-documented source of both DNA damage and repair in somatic tissues, is associated with sex differences in germline mutations. To this end, we used expression data from male and female germline cells and phased de novo germline mutations from pedigrees. Focusing on protein-coding genes, we found no relationship between the male mutation rate and gene expression levels in the fetal germline or in adult testis tissue, despite evidence for transcriptional asymmetry. Individual stages of spermatogenesis differ in their contribution to mutation, however: expression levels in spermatogonial stem cells are significantly positively associated with paternal mutation rates, while those in primary spermatocytes are significantly negatively associated. Thus, transcription may have varying effects over male gametogenesis that are not readily detected from its cumulative effect on the total germline mutation rate. In females, by contrast, mutation rates increase significantly with transcription levels in the fetal germline, adult oocytes and adult ovary tissues, consistent with widespread transcription asymmetry. We confirm the difference between the sexes by analyzing phased mutations from three-generation pedigrees and the lack of an association in males by analyzing paternal mutations from seminiferous tubules and sperm. Thus, transcription has distinct effects on the mutation rate in the two sexes, leading to an increase in mutations in females but not males, in contrast to what one might expect from the overall paternal bias in germline mutations.

Objectives Concerns about COVID-19 were a key driver of infection-prevention behaviour during the pandemic. The aim of this study was to gain an in-depth longitudinal understanding of the type and frequency of concerns experienced throughout the first two years of the COVID-19 pandemic. Design Content analysis of qualitative descriptions provided in a prospective longitudinal online survey as part of the COVID-19 UK Public Experiences (COPE) Study. Method At baseline (March/April 2020), when the UK entered its first national lockdown, 11,113 adults completed the COPE survey. Follow-up surveys were conducted at 3, 12, 18 and 24 months. Participants were recruited via the HealthWise Wales research registry and social media. Baseline surveys collected demographic and health data, and all waves included an open-ended question about COVID-19 concerns. Content analysis was used to identify the type and frequency of concerns at each time point. Results A total of 41,564 open-text responses were coded into six categories: personal harm (n=16,353), harm to others (n=11,464), social/economic impact (n=6,433), preventing transmission (n=4,843), government/media (n=1,048), and general concerns (n=1,423). The proportion of respondents reporting any concern declined from 75.3% at baseline to 65.8% at 24 months. Over time, concerns about personal harm increased (baseline 41.8% vs. 24-months 52.7%) whereas concerns about harm to others decreased (baseline 48.5% vs. 24-months 28.6%). Concerns about harm were also expressed in relation to clinical vulnerability, lack of trust in government/media, and perceived lack of adherence by others. These were balanced against concerns about wider social and economic impacts of restrictions. Conclusions Public concerns about COVID-19 evolved substantially over the first two years of the pandemic, reflecting changing perceptions of risk and responsibility. Monitoring concerns longitudinally is vital to help guide effective communication and behavioural interventions during future pandemics.

Substance use disorders run in families, yet the mechanisms underlying intergenerational transmission remain unclear. We investigated indirect genetic effects, pathways through which parental genotypes influence offspring phenotypes via the family environment, for alcohol use disorder (AUD), nicotine dependence (ND), and related quantitative outcomes, and aimed to identify family environmental factors through which such effects may operate. Using transmitted and non-transmitted polygenic scores (PGS) constructed for problematic alcohol use, tobacco use disorder, and general addiction liability, we analyzed 5972 European-ancestry adult offspring with at least one genotyped parent from the population-based Lifelines cohort (Netherlands). Offspring outcomes included lifetime DSM-5 AUD diagnosis, AUD symptom count, maximum drinks in 24 hours, Fagerstrom Test for Nicotine Dependence score, and cigarettes per day. AUD findings were meta-analyzed with data from the Brisbane Longitudinal Twin Study (N = 1368; Australia). We also examined parent-of-origin effects and mediation by parental substance use and socioeconomic status using structural equation modeling. Transmitted PGS robustly predicted all AUD and ND outcomes ({beta} = 0.07-0.16; OR = 1.20 for AUD diagnosis). Non-transmitted PGS, indexing indirect genetic effects, were negligible for all clinical syndrome outcomes. The only significant indirect genetic effect was on cigarettes per day ({beta} = 0.03, p = 0.01), mediated by parental smoking behavior but not socioeconomic status. These findings indicate that intergenerational transmission of risk for AUD and ND is driven primarily by direct genetic effects, with modest indirect genetic effects on smoking quantity. Larger samples and cross-trait analyses are needed to further elucidate these mechanisms.

Background Tuberculosis (TB) remains a critical public health challenge, with two-thirds of the global TB burden in ten Asian countries. Social vulnerabilities, comorbidities, health inequity, multi-dimensional poverty, malnutrition, and barriers to healthcare access continue to fuel TB epidemic. Inability to detect asymptomatic and sub-clinical TB, combined with passive approach in service delivery and overreliance on smear microscopy, leads to delayed diagnosis, a substantial burden of undetected cases, and continuing TB transmission in the communities. In such a context, the introduction and scale-up of active case-finding approaches - including community-based TB screening using highly sensitive screening tools and novel rapid diagnostics - becomes a strategic priority to interrupt transmission. The growing availability of multiple screening and diagnostic options makes evidence-based decision-making increasingly complex. Methods To estimate the potential epidemiological impact and cost implications of scaling up TB diagnostics and community-based screening in ten high-burden Asian countries, we constructed a mathematical model and evaluated multiple intervention scenarios. We then assessed and compared four service delivery models: 1) digital ultraportable chest x-ray (UPCXR) & Xpert/Truenat in community, 2) digital UPCXR in community and Xpert/Truenat at health facilities, 3) digital UPCXR in community and near point of care (nPOC) at health facilities, 4) nPOC in community & Xpert/Truenat at health facilities - for total investment required and projected health benefits for their cost-effectiveness. Results and conclusions The modelling study indicated that strengthening health facility capacity (with enhanced TB screening, expanded molecular diagnostics, reduced loss to follow-up, private sector standard of care, leading to increased treatment coverage & quality of active disease treatment and reduced post-treatment relapse, scale-up of TB preventive treatment (TPT), and provision of nutritional support to 80% of TB patients and their household contacts) can significantly reduce TB incidence and mortality; however, community-wide mass screening remains essential to achieving TB elimination targets . Targeted screening of vulnerable populations demonstrated greater cost-effectiveness than untargeted screening approaches. Achieving the End TB goals will ultimately require an effective TB vaccine with high population-level coverage. AI-enabled digital UPCXR-based screening combined with Xpert/Truenat testing at the community level demonstrated maximum epidemiological impact potential, while the most cost-efficient model is Digital UPCXR in the community combined with nPOC testing at health facilities. An investment of USD 12.7 billion over the next five years in community-level implementation of digital UPCXR and molecular diagnostics could avert an additional 9.8 million TB cases and 1.9 million deaths across ten Asian countries over a ten-year horizon.

The cerebellum rapidly integrates with cerebral networks during infancy and shows consistent structural and functional alterations in Autism Spectrum Disorder (ASD), suggesting that early cerebellar development may be consequential for later behavioral and psychiatric outcomes. Yet, little is known about the effect of ASD genetic liability on cerebello-cerebral functional connectivity in infancy or whether effects may differ by biological sex. Here, we leveraged neonatal functional magnetic resonance imaging, genetic, and behavioral follow-up data from the Developing Human Connectome Project (dHCP) to examine the relationship between ASD polygenic scores (PGS) and functional connectivity of cerebellar regions associated with sensorimotor and social-cognitive functions in 198 term-born neonates (mean age: 9.7 days). We report widespread sex differences in neonatal cerebello-cerebral connectivity that are regionally specific across cerebellar subdivisions. Across the full sample, elevated ASD PGS predicted alterations in cerebello-cerebral connectivity, with hemisphere-dependent differences in sensorimotor cerebellar connectivity with temporal cortex, and hyperconnectivity between the right social-cognitive seed and posterior cingulate. Notably, elevated ASD PGS predicted opposing patterns of cerebello-cerebral connectivity in males and females, including male hyperconnectivity between the right sensorimotor cerebellum and default mode areas, and female hyperconnectivity between the right social-cognitive seed and sensorimotor cortex. Connectivity associated with elevated ASD PGS showed nominal, sex-specific associations with 18-month language ability, attention problems, and emotional reactivity. Our findings show that ASD PGS influences the functional configuration of the cerebellum at birth and suggest that underlying cerebellar connectivity profiles associated with ASD may partially underlie distinct behavioral presentations in males and females.

Background: Type 2 diabetes mellitus (T2DM) has long been considered a risk factor for cerebral small vessel disease (cSVD), yet the exact relationship between glycemic markers and cSVD remains unclear. This study explores the genetic overlap and causal associations between T2DM, glycemic indices, and cSVD phenotypes using genome-wide association studies (GWAS). Methods: Using large consortium-based GWAS data, we examined relationships between T2DM, glycemic indicators (glycated hemoglobin, fasting glucose, 2-hour glucose after oral challenge, and fasting insulin), and cSVD phenotypes (white matter hyperintensity volume, lacunar stroke, cerebral microbleeds, and enlarged perivascular spaces). Our multi-level genomic strategy included: 1) identifying pleiotropic single nucleotide polymorphisms (SNPs) through PLEIO and eQTL analysis, 2) assessing genome-wide genetic correlations using LDSC and GNOVA, and 3) determining causal relationships with two-sample and multivariable Mendelian randomization analyses. Results: We identified 14 pleiotropic SNPs with significant shared associations among T2DM, glycemic indicators, and cSVD phenotypes. Notably, MICB gene expression was elevated in brain, vascular, and pancreatic tissues, while three HLA genes (HLA-DQA1, HLA-DRB1 and HLA-DRB5) showed reduced expression. Genetic correlation analysis revealed positive correlations between T2DM, fasting glucose, and postprandial glucose with multiple cSVD phenotypes including WMH, lacunar stroke, and perivascular spaces. Mendelian randomization demonstrated that T2DM, 2-hour glucose, and HbA1c level causally increased lacunar stroke risk (OR 1.16 [1.09-1.23], OR 1.46 [1.20-1.77], OR 1.52 [1.04-2.23], respectively). Multivariable Mendelian randomization analysis confirmed that T2DM and postprandial glucose maintained a robust direct effect on lacunar stroke independent of other cSVD phenotypes, while HbA1c did not retain significance after conditioning on cSVD imaging markers. Conclusions: Our multi-level genomic analysis reveals links between T2DM, glycemic traits, and cSVD through specific genetic variants, genome-wide correlations, and causal relationships. The involvement of immune-related genes suggests potential biological mechanisms. The causal effect of postprandial glucose on lacunar stroke suggests that impaired glucose tolerance may be a relevant therapeutic target for lacunar stroke prevention.

Purpose: This study aimed to examine the effects of formative and summative assessments on college students tennis performance and basic psychological needs. Methods: A total of 128 undergraduate students (64 males, 64 females; Mage = 19.22, SD = 0.91) participated in this study. Participants were cluster-randomized to either a formative assessment group (n = 64) or a summative assessment group (n = 64). The formative assessment intervention involved setting personalized learning goals and success criteria, administering periodic tests, and providing process-oriented and individualized feedback. The summative assessment intervention involved setting uniform goals for all students, offering instructor feedback only on common problems, and requiring students to practice independently after class without personalized guidance. Both interventions were implemented over 10 weeks, with one 90-minute session each week. Tennis skills and basic psychological needs (i.e., autonomy, competence, and relatedness) were assessed before and after the intervention. Tennis skills were reassessed 1 week after the intervention. Two-way mixed-effects analysis of variance (ANOVA) was used to examine the impact of group, time, and their interaction on tennis skills and basic psychological needs. Results: The results showed that the interaction between group and time was significant for all of the outcome variables. Simple effects analyses indicated that, at pre-test, the two groups did not differ significantly in tennis performance or in satisfaction of autonomy, competence, and relatedness (p > 0.05). At post-intervention, the formative assessment group demonstrated significantly better performance than the summative assessment group in tennis skills (MD = 3.50, 95% CI = [1.303, 5.697], p = 0.002), autonomy (MD = 2.44, 95% CI = [1.816, 3.059], p < 0.001), relatedness (MD = 1.33, 95% CI = [0.679, 1.977], p < 0.001), and competence (MD = 1.75, 95% CI = [1.046, 2.454], p < 0.001). At the 1-week follow-up session, the formative assessment group also showed significantly better tennis performance than the summative assessment group (MD = 6.81, 95% CI = [4.667, 8.958], p < 0.001). Conclusion: Formative assessment was more effective than summative assessment in improving college students tennis performance and satisfying their basic psychological needs. These findings suggest that incorporating personalized goals, process-oriented evaluation, and individualized feedback into tennis instruction could promote both skill development and psychological outcomes in college physical education.

Introduction: Physical inactivity and sedentary behaviour are significant risk factors for noncommunicable diseases. Engaging in regular physical activity (PA) during childhood is crucial for preventing long-term health burdens. This study examined PA levels and associated factors among upper primary school children in Lusaka, Zambia. Methodology: A cross-sectional survey was conducted from August to October 2022 among 638 children aged 9-18 years from six public and six private schools. Data were collected using the Physical Activity Questionnaire for Children (PAQ-C), Youth Risk Behaviour Survey (YRBS), Model of Youth Physical Activity Questionnaire (MYPA), and 3-Day Physical Activity Recall Questionnaire (3DPAR). Analyses included descriptive statistics, Chi-square, Fishers exact tests and multivariable binary logistic regression at a 0.05 significance level and 95% confidence interval. Results: Most participants (82%) were insufficiently active, with only 18% achieving sufficient PA. Reported barriers included lack of playgrounds or parks near home (p=0.012), neighbourhood safety concerns (p=0.041), and limited parental supervision (p=0.006). Watching television reduced the odds of PA by 69% (aOR=0.31; 95% CI: 0.13-0.75). Conversely, peer support increased activity by 15% (aOR=1.15, 95% CI: 0.67-1.97), while not being concerned about showering or fixing hair after PA increased activity by 94% (aOR=1.94; 95% CI: 1.21-3.11). Conclusion: The majority of school children in this study did not meet recommended PA levels. Barriers to activity included personal, parental, and environmental factors. Interventions should prioritise safe play spaces, increased parental and peer support, and reduced screen time to curb future non-communicable disease risks.

Background: Kidney transplantation is the preferred treatment strategy for end-stage kidney disease. Deceased donor kidneys usually undergo cold storage until kidney transplantation, leading to cold ischemia injury that may contribute to poor graft outcomes. However, the molecular characterization of potential mechanisms of cold ischemia injury remains incomplete. Results: To bridge this knowledge gap, we leveraged the 10x Visium spatial transcriptomic technology to perform full transcriptome profiling of murine kidneys subject to varying durations of cold ischemia typical in a deceased donor kidney transplant setting. We developed a computational workflow to identify and compare spatiotemporal transcriptomic changes that accompany the injury pathophysiology in a tissue compartment-specific manner. We identified proportional enrichment of oxidative phosphorylation (OXPHOS) genes with increasing duration of cold ischemia injury within the oxygen-lean inner medulla region, suggestive of atypical metabolic presentation. This was distinct in cold ischemia injury tissue compared to warm ischemia-reperfusion kidney injury tissue. Spatiotemporal trends were validated by qPCR and immunofluorescence in a larger cohort of mice. We provide an interactive online browser at https://jef.works/CellCarto-ColdIschemia/ to facilitate exploration of our results by the broader scientific and clinical community. Conclusions: Altogether, our spatiotemporal transcriptomic analysis identified coordinated molecular changes within metabolic pathways such as OXPHOS deep within the cold ischemic kidney, highlighting the need for increased attention to the inner medulla and potential opportunities for new insights beyond those available from superficial biopsy-focused tissue examinations.

Background: The COVID-19 pandemic disrupted childhood immunization programmes in many countries worldwide. However, evidence on its impact in low and middle-income countries remains limited. This study examined the impact of the COVID-19 pandemic on childhood immunization coverage across 514 districts in Indonesia and identified district-level associated factors. Methods: We conducted a nationwide longitudinal analysis of the Expanded Programme on Immunization to compare immunization coverage before and after the pandemic. The outcome variable was the annual childhood immunization coverage (proportion of children aged 0-12 months who have received all recommended doses of childhood immunization as per the national immunization schedule). The explanatory variables include COVID-19 burden and vaccination rates, health system and human development indicators. Mixed-effect logistic regression was done to assess association between the explanatory and outcome variables. Results: At the national level, the coverage was 83.2% in pre-pandemic, 75.0% in the first year of pandemic, and 88.6%, in the second. In the first year, 69.3% of districts experienced significant decline, with a lower national coverage ratio of 0.92 (95% confidence interval 0.89-0.94). In the second year, 36.2% districts were still affected. The multivariable analysis showed that a significant decline in coverage during the first pandemic year was associated with high COVID-19 incidence (adjusted odds ratio 2.19, 95%CI 1.01-4.73 for the highest vs. lowest group), low midwife adequacy (5.84, 2.40-14.16 for the lowest vs. the highest group, 2.61, 1.26-5.40 for low-middle vs. the highest group), and a high proportion of health facility-based births (2.98, 1.49-5.98 for middle-high vs. the lowest group). Conclusions: The COVID-19 pandemic negatively and unevenly impacted childhood immunization in Indonesia, with greatest impacts in districts facing a higher COVID-19 burden and weaker health system capacity. These findings underscore the need for targeted efforts to strengthen the local health system for future health crises. Keywords: COVID-19, pandemic, immunization, vaccine preventable diseases

Background Poor physical function has been associated with higher cardiovascular disease (CVD) risk. However, the association between physical function and atrial fibrillation (AF) remains understudied. The comprehensive investigation of the association between physical function and incident AF risk could highlight a novel target for AF prevention. Methods A total of 4,803 participants without diagnosed AF from the Atherosclerosis Risk in Communities (ARIC) Study cohort with physical function assessed in 2011-2013 were studied. Physical function was measured using Short Physical Performance Battery (SPPB), 4-meter walk time, and grip strength. Hospital discharge codes and death certificates were used to ascertain incident AF through 2022, and through 2020 for participants from Jackson. Cox regression was used to assess the association between physical function and incident AF risk, adjusting for multiple covariates. Z-score transformations were performed to identify the physical function measure most strongly associated with incident AF risk, and SPPB component analysis was performed to identify the most influential SPPB component. Results Mean age of the study participants was 75.1 {+/-} 5.0 years, with 41.2% being male participants and 22.2% being black participants. During a median follow-up of 9.2 years, there were 809 incident AF events. SPPB (HR: 0.93, 95% CI: 0.90-0.96, per 1-point increase) and grip strength (HR: 0.87, 95% CI: 0.78-0.96, per 10kg increase) were inversely associated with incident AF risk, while 4-meter walk time (HR: 1.08, 95% CI: 1.03-1.13, per 1-second increase) was positively associated with incident AF risk. SPPB had the strongest association with incident AF risk. Within SPPB, only the chair stand component was significantly associated with incident AF risk. Conclusions The findings suggest that better physical function is associated with reduced incident AF risk, with higher SPPB having the strongest association. Given the modifiable nature of physical function, these findings highlight a potential novel target for AF prevention in aging populations.

Previous studies have linked opioid use to altered metabolic profiles, but findings have been inconsistent and mechanisms remain unclear. One potential mechanism involves increased adiposity, leading to chronic low-grade inflammation that elevates metabolic risk. Here, we examined metabolic profiles in individuals with opioid use disorder (OUD) and matched non-OUD controls, focusing on the sequential mediating roles of BMI and inflammation. Data from individuals with OUD (n=281) and non-OUD (n=246) were drawn from a natural history screening protocol from the National Institute on Alcohol Abuse and Alcoholism intramural program. Groups were matched on age, sex, race, ethnicity, socioeconomic status, and education via propensity score matching. Metabolic measures included BMI, blood glucose, hemoglobin A1c (HbA1c), and lipid profiles, with lipid imbalance indexed by the atherogenic index of plasma (AIP). Inflammatory markers included C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR). Individuals with OUD had significantly higher BMI (F1,481=12.9, p<0.001), HbA1c (F1,481=10.5, p=0.001), lower high-density lipoprotein cholesterol (HDL-C; F1,481= 46.2, p< 0.001), higher low-density lipoprotein cholesterol (LDL-C; F1, 481=11.9, p< 0.001), and higher AIP (F1,481=20.7, p< 0.001) compared to non-OUD. Inflammatory markers were also elevated in individuals with OUD, including CRP (F1,481=9.4, p=0.002) and ESR (F1,481=7.4, p= 0.007), and statistically mediated group differences in AIP and HbA1c, respectively. Our results are consistent with prior evidence of metabolic dysfunctions in individuals with OUD and suggest inflammation as a contributing mechanism. Targeting metabolic health and inflammation may offer new avenues for improving long-term health outcomes in OUD.

Objective: Improved diet quality is increasingly important for comorbidities management and healthy aging in people with HIV (PWH). Yet, limited data exist on dietary patterns and their correlates in this population. This study aimed to (1) characterize dietary patterns among adult PWH and (2) identify demographic, clinical, and HIV related factors associated with diet quality. Methods: We conducted a cross sectional analysis of PWH enrolled in the PROSPER HIV study across four U.S. academic medical centers. Dietary intake was assessed using three 24 hour dietary recalls and scored using the Healthy Eating Index 2015 (HEI2015). Participants were categorized into tertiles based on total HEI2015 scores. Between group comparisons were performed using Kruskal Wallis and chi square tests. Factors independently associated with HEI2015 scores were identified using multivariable linear regression. Results: A total of 491 PWH were included with a median age of 54 years; 76.4% were male. Overall diet quality was low with inadequate intake of dietary protein, fiber, and micronutrients. When classified by tertiles of HEI 2015 score, higher diet quality was characterized by greater intake of fiber, protein, and key micronutrients. Older age was independently associated with higher HEI 2015 scores, while Black race was associated with lower scores. Full time employment and absence of current pain were marginally associated with better diet quality. Conclusions: Diet quality among PWH varies substantially and is influenced by age, race, and social determinants. Tailored nutritional strategies are needed to support healthy aging and reduce disparities in this population.

Background: Moderate- to high-intensity walking training (M-HIT) is an established intervention for improving walking capacity in chronic stroke. Musculoskeletal (MSK) adverse events commonly occur during M-HIT, yet tools to identify individuals at higher risk are limited. Baseline clinical characteristics may provide insight into susceptibility to training-related MSK adverse events during M-HIT. Thus, this study aimed to develop and internally validate a model for predicting MSK adverse events during a 12-week M-HIT program in chronic stroke using baseline clinical characteristics. Methods: Participants (n=100) from HIT-Stroke Trials 1 and 2 were included. Baseline clinical characteristics included measures of orthopedic history, pre-existing pain, motor function, recent exercise history, demographics and health characteristics, stroke chronicity, and psychological health. Logistic regression models evaluated all possible combinations of baseline characteristics with up to three predictors. Leave-one-out cross-validation was used for internal validation to mitigate overfitting. Predictive performance was quantified using the C-statistic, and the candidate model with the highest cross-validated C-statistic was selected as the final model. Results: MSK adverse events occurred in 32.0% of participants. The optimal three-variable model included prior orthopedic condition (Odds ratio [OR] 3.02 [95% CI 1.14-8.64]), Fugl-Meyer lower extremity motor score (OR 1.14 [95% CI 1.02-1.28]), and self-reported participation in regular walking exercise (OR 0.17 [95% CI 0.05-0.49]) at baseline. This model demonstrated moderate discrimination (cross-validated C-statistic = 0.74; apparent C-statistic = 0.78). Conclusions: Participants reporting at least one pre-existing lower extremity or lumbar spine orthopedic condition and those with better lower-extremity motor function exhibited greater odds of experiencing MSK adverse events during M-HIT, while participants reporting participation in regular walking exercise had lower odds. These findings suggest that baseline clinical characteristics may help identify individuals at elevated risk for MSK adverse events during M-HIT who may warrant closer monitoring or risk-reduction strategies. Future studies are needed for external validation. Clinical Trial Registration: https://ClinicalTrials.gov; Unique identifiers: NCT03760016, NCT06268041

Background: Brain magnetic resonance elastography (MRE) is an emerging quantitative neuroimaging technique that provides noninvasive maps of brain tissue viscoelasticity. For multi-center applications, robust cross-site reproducibility across scanner platforms is essential but remains insufficiently characterized. Purpose: To evaluate cross-site reproducibility of brain multifrequency MRE measurements between two MRI scanner platforms using harmonized protocols. Study Type: Prospective cross-site test-retest reproducibility study. Study Population: Sixteen healthy adult volunteers (7 men, 9 women; mean age 32.2 +/- 8.0 years). Field Strength/Sequence: 3 T systems (Siemens MAGNETOM Cima.X and MAGNETOM Vida at two sites) with identical brain multifrequency MRE sequences, echo-planar imaging (EPI) readout, and standardized driver configuration. Assessment: Each participant underwent one MRE acquisition at each site. Shear wave speed (SWS) and penetration rate (PR) were quantified in whole brain, white matter, subcortical gray matter, and cortical gray matter regions using atlas-based region-of-interest (ROI) analysis in MNI152 space. Statistical Tests: Absolute relative difference (ARD), reproducibility coefficient (RDC), coefficient of variation (CV), intraclass correlation coefficient (ICC), and Bland-Altman plots were calculated to determine cross-site reproducibility. Results: Cross-site reproducibility was robust for major brain regions, with region-averaged ARD values for SWS ranging from 1.38 % to 3.43 % and for PR from 3.20 % to 7.25 % across tissues. RDCs for SWS ranged from 0.02 m.s^-1 to 0.07 m.s^-1 , and for PR from 0.03 m.s^-1 to 0.08 m.s^-1. Coefficients of variation for SWS ranged from 0.82 % to 1.93 %, and for PR from 2.21 % to 4.09 %. ICC values for SWS ranged from 0.66 to 0.84 and for PR from 0.67 to 0.88. Bland-Altman analysis showed minimal systematic bias and tight limits of agreement. Conclusion: Brain multifrequency MRE demonstrates robust reproducibility across distinct 3 T platforms when using harmonized acquisition and reconstruction. These results support the use of brain MRE as a quantitative biomarker and provide benchmark reproducibility metrics for future research.

T-cell activation may be contributing to severe psychiatric disorders. Soluble CD27 (sCD27) - a marker for T-cell activation and disease activity in several autoimmune diseases - was evaluated as a tool for distinguishing T-cell activity in selected patients with severe psychiatric disorders, multiple sclerosis (MS), and controls. We hypothesise that elevated sCD27 levels will be associated with comorbid autoimmune disease (AID). sCD27 was measured in cerebrospinal fluid (CSF) and blood from a population enriched for suspected immunological comorbidity: the Immunopsychiatry Cohort (IP; n=115) and patients with MS (n=37), where levels in both groups were higher when compared with age matched controls undergoing surgery (n=154). Positive sCD27 (sCD27+), was defined as values >97.5% of controls. In IP, 23% were CSF sCD27+ and 15% blood sCD27+, compared to patients with MS where 88% were CSF sCD27+ and 22% were blood sCD27+. CSF-sCD27+ was confirmed as a sensitive marker for MS. In IP, CSF-sCD27+ was associated with comorbid AID (X2=4.847, p =0.028;) and AID disease activity (OR=5.14, p=0.029). Associations with AID were stronger when CSF and/or blood sCD27+ were combined (X2=8.559, p=0.003). CSF-sCD27+ in IP was also associated with pleocytosis, CSF-Total-tau, and CSF-NfL. In patients with severe psychiatric disorders, the sCD27+ cases were more likely to have comorbid AID and established markers for neuroinflammation in CSF. Combining analyses of CSF and blood improved sensitivity and specificity for AID suggesting compartmentalized T-cell activation. Psychiatric symptoms may precede somatic symptoms - or be the prominent symptom - of AID and sCD27 is a candidate marker for identification of this subgroup.

Introduction: Sleep-dependent memory consolidation differs by sex and maybe disrupted by Alzheimer disease (AD) risk. Whether sex moderates associations between apolipoprotein E {varepsilon}4(APOE {varepsilon}4) status, non-rapid eye movement (NREM) sleep, and memory remains unclear. Methods: Eighty cognitively unimpaired older adults completed a word-pair memory task with encoding and immediate testing occurring prior to overnight polysomnography with high-density electroencephalography (hdEEG) and delayed recall occurring after sleep. Sleep-memory associations were examined as a function of sex and APOE {varepsilon}4 status. Results: In this sample, a sex by APOE {varepsilon}4 interaction was associated with overnight memory retention, with female carriers exhibiting less overnight forgetting than female non-carriers and male {varepsilon}4 carriers. NREM sleep differed by sex and APOE {varepsilon}4 status and was associated with memory retention in {varepsilon}4 carriers. Discussion: These findings indicate sex-specific, sleep-dependent memory mechanisms associated with genetic AD risk, highlighting sleep as a potential early target for intervention, pending replication in larger samples. This study was not a clinical trial.

Metabolic dysfunction-associated steatotic liver disease (MASLD) exhibits marked heterogeneity and sex differences, yet the molecular mechanisms underlying disease progression remain incompletely understood. Here, we present the largest integrative multi-omics study to date combining matched liver tissue and blood profiling in 211 biopsy-confirmed, morbidly obese individuals with MASLD undergoing bariatric surgery. We integrate hepatic transcriptomics, metabolomics, and lipidomics with serum metabolomics to resolve compartment-specific and sex-dependent molecular networks. Across sexes, MASLD is characterized by suppressed hepatic amino acid metabolism and extensive lipid remodeling, accompanied by inverse metabolic signatures in circulation, consistent with systemic spillover. Strikingly, disease progression in men is driven by a streamlined triacylglycerol-centric pathway that mediates transcriptional effects on steatosis and inflammation, whereas women exhibit distributed, multi-layered networks linking lipid, amino acid, and immune pathways. Mediation analyses identify hepatic lipid modules as key intermediates connecting gene expression to histopathology. These findings reveal sex-specific molecular architectures of MASLD, demonstrate that circulating biomarkers do not reflect hepatic metabolism, and provide a framework for sex-specific precision medicine.