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The present study provides novel physiological insights into aging by measuring airway compliance and residual volume via forced oscillation perturbations using a programmable mechanical ventilator (flexiVent—currently considered a gold standard for in vivo lung function measurements). In addition, dynamic measurements of lung inflation reported herein may serve as early indicators of altered elastic properties. Taken together, the findings offer a comprehensive assessment of age-related changes in lung structure and function.

Abstract Background Keratoconus (KC) is a multifactorial disorder with unclear etiology, characterized by localized thinning and a cone-like protrusion of the cornea. The complex etiology of KC exacerbates the lack of an animal model. Previous studies by Tachibana et al. (2002) described an inbred mouse strain (SKC) with a spontaneous, androgen-dependent, cone-like corneal morphology. This study aimed to investigate the corneal phenotypes of SKC mice through an in-depth ophthalmic examination. Methods Mice (n=53) were examined via slit lamp biomicroscopy with fluorescein staining. Spectral-domain optical coherence tomography (SD-OCT) enabled central corneal thickness (CCT) measurement in selected mice (n=26 eyes), and OCT-based pachymetry mapping (n=16 eyes). In vivo corneal confocal microscopy was conducted on eyes to assess cellular morphology (n= 9 eyes). Eyes were collected for histology analysis (n=22). Results Lesions and epithelial breaks were present in ∼95% of eyes (n=101). Neovascularization, perforation, scarring, and hydrops were seen primarily in males. An opaque, unilateral cone-like morphology was exclusive to males (n=11). Male and female corneas showed no significant difference in CCT, though pachymetry mapping revealed regional thinning patterns in both sexes. Loosened epithelial tight junctions, stromal fibrosis, vascularization, and inflammation of variable severity were identified in both sexes. Conclusion This study identified previously unreported corneal phenotypes in SKC mice through ophthalmic examination. Unlike previous studies, gross and histological abnormalities were observed in female SKC mice. Our findings suggest a lower penetrance of the cone-like phenotype (∼20%) than previously reported (∼33%) and support that the conical phenotype in male mice may be secondary to keratitis.

Background Strengthening emergency care systems could reduce death and disability in low- and middle-income countries (LMICs), yet many struggle to provide timely, high-quality care. LMICs also face growing risks from climate-related shocks and mass casualty events. This study identifies unmet emergency care needs in Nepal—one of the world’s most climate-vulnerable countries—using high-resolution geospatial data to estimate socioeconomic and climate-related inequalities. Methods We conducted a cross-sectional geospatial analysis using data from the 2022 Nepal Demographic and Health Survey (DHS), the 2021 DHS Service Provision Assessment and publicly available climate vulnerability data. Government hospitals were classified into three emergency care levels using World Health Organzation criteria: A (basic 24-hour services), B (A plus resuscitative capabilities) and C (B plus ≥50 beds and a surgeon). Household location and injury data were obtained from the DHS. Accessibility was defined as the proportion of the population within 1-hour and 2-hour travel times, estimated using AccessMod 5.8, incorporating road networks, rivers, land cover and elevation. Findings Most public hospitals (77.7%) met Level A criteria but only 49.3% met Level B and 10.8% met Level C. Nationally, 78.7% of households had 1-hour access to Level A care, 71.8% to Level B and 44.6% to Level C. Adjusted logistic regression showed rural, poorer and climate-vulnerable households had significantly lower 1-hour access compared with urban households, rural households had lower odds of access: Level A OR: 0.33 (95%CI 0.30 to 0.37), Level B OR: 0.33 (95%CI 0.30 to 0.36), Level C OR: 0.56 (95%CI 0.51 to 0.61). Households in high climate vulnerability areas had reduced access across all levels. Conclusions Substantial gaps and inequities in timely access to high-quality emergency care exist in Nepal. Rural, poorer and climate-vulnerable populations experience markedly lower access. Targeted, decentralised strengthening of emergency care capacity is essential both in Nepal and in other LMICs facing similar constraints.

Background and Aims: Unresolved inflammation and fibrosis are defining features of metabolic dysfunction–associated steatohepatitis (MASH), a progressive form of steatotic liver disease that can advance to cirrhosis and hepatocellular carcinoma. While innate immune mechanisms in MASH have been extensively characterized, the role of CD4 + T cells remains poorly understood despite their central function in orchestrating immune responses through effector and regulatory mechanisms. Approach and Results: Integrated single-cell proteomic, transcriptomic, and functional analyses were used to investigate the CD4 + T-cell landscape in murine and human MASH. We delineated a profound shift in the differentiation of intrahepatic and peripheral CD4 + T cells toward Th1, regulatory, and cytotoxic phenotypes in murine and human MASH. Notably, hepatic CD4 + T cells exhibited heightened effector activity and elevated secretion of proinflammatory cytokines, thus amplifying inflammatory signaling cascades. The CD4 + T-cell reprogramming in MASH also included the induction of the co-stimulatory receptor OX40. In parallel, OX40 ligand (OX40L)-expressing monocyte-derived macrophages and dendritic cells accumulated in MASH livers, establishing a feed-forward CD4 + T cell-myeloid activation loop. Therapeutic blockade of the OX40–OX40L axis, in turn, reversed liver pathology in mice with established MASH and reduced disease markers in an ex vivo human liver model. Furthermore, genetic depletion or functional inhibition of CD4 + T cells attenuated fibrosis, accompanied by decreased infiltration of monocyte-derived macrophages. Conclusions: These studies provide a comprehensive single-cell proteogenomic atlas of CD4 + T cells in MASH and identify an OX40-dependent CD4 + T cell-macrophage axis as a promising therapeutic target for the treatment of MASH and liver fibrosis.

Abstract Purpose: Circulating tumor fraction estimate (ctFE) is a machine learning–derived composite metric of circulating tumor DNA (ctDNA) burden. We hypothesized that pre-treatment and early on-treatment ctFE could robustly risk-stratify patients with locally advanced (LA) and oligometastatic non–small cell lung cancer (NSCLC) treated with radiotherapy (RT). Experimental Design: In a prospective phase II clinical trial (NCT03916419), 26 patients with unresectable stage IIB to IIIC NSCLC received magnetic resonance (MR)-guided hypofractionated chemoradiotherapy (chemoRT) followed by immunotherapy. Plasma ctDNA was profiled at baseline and mid-treatment (days 10–14) to derive ctFE and maximum variant allele frequency (Max VAF). A burden-based ctFE threshold derived from baseline samples was applied unchanged to mid-treatment samples and validated in two external cohorts: LA NSCLC treated with chemoRT (LA-RW; n = 94) and oligometastatic NSCLC treated with RT (OM-RW; n = 309). Results: Pre- and mid-treatment ctFE burden strongly stratified overall survival (OS) and progression-free survival (PFS), outperforming Max VAF and ctFE detectability. The baseline ctFE was prognostic for OS (HR 5.93, P = 0.005) and PFS (HR 11.08, P < 0.001) and remained significant at mid-treatment (OS: HR 7.08; PFS: HR 12.06; both P < 0.001). Early ctFE dynamics defined three molecular response groups with OS separation (median OS 60.8 vs. 13.0 vs. 2.9 months; P < 0.001). ctFE remained associated with survival in both validation cohorts. Conclusions: Early ctFE derived from a clinically available, tumor-naïve ctDNA assay enables noninvasive risk stratification in LA and oligometastatic NSCLC treated with RT, supporting its use as a practical biomarker for precision treatment adaptation.

Background: Mindfulness-based interventions may improve cardiovascular health (CVH) by supporting behavioral change across multiple risk factors. This study evaluated the impact of Mindfulness-Based Blood Pressure Reduction (MB-BP), a mindfulness program targeting hypertension-related behaviors ( Image 1 ), on CVH using the American Heart Association’s Life’s Essential 8 framework. Methods: This secondary analysis of parallel-group, phase 2 randomized clinical trial evaluated the effects of MB-BP on CVH in 201 participants with elevated office BP (≥120/80 mmHg). The MB-BP group (n=101) received an 8-week program focused on mindfulness training and education targeting diet, physical activity, medication adherence, alcohol use, and stress, whereas the control group (n=100) received enhanced usual care ( Image 2 ). CVH was assessed using available Life’s Essential 8 components: systolic blood pressure, body mass index (BMI), diet (DASH adherence), physical activity, smoking, and sleep duration. Generalized estimating equations evaluated intervention effects through six months. Results: At six months follow-up, MB-BP participants significantly improved composite CVH scores compared to controls (standardized mean difference: 0.144; 95% CI: 0.023, 0.266) ( Image 3 ). MB-BP influenced most CVH components in healthier directions at trend levels, with the strongest responses for physical activity (47.9 MET min/week; 95% CI: -16.5, 112.3), sleep (0.34 hours/night; 95% CI: -0.10, 0.78), systolic blood pressure (-4.95 mmHg; 95% CI: -10.34, 0.44) and DASH diet score (0.27, 95% CI: -0.15, 0.69). Conclusions: MB-BP led to modest but clinically significant improvements in CVH, driven by multiple Life’s Essential 8 components. These findings suggest that MB-BP may be an effective behavioral intervention to support CVH and reduce risk for cardiovascular disease. ClinicalTrials.gov Preregistration Identifiers: NCT03256890, NCT03859076

Background: Stroke is a major health burden and the second leading cause of death globally, only after ischemic heart disease. While observational studies have elaborated on the effect of physical activity (PA) and sedentary behavior (SB) on stroke risk, their findings remain inconsistent and are often influenced by confounding factors and reverse causation. Mendelian randomization (MR) can help overcome these shortcomings and assess potential causal relationships using genetic variants as proxies for exposures. Methods: We conducted a systematic review and meta-analysis of MR studies investigating the effects of PA and SB on stroke risk. Following PRISMA guidelines, we searched PubMed and Google Scholar through May 2025. Eligible studies used two-sample MR designs to estimate the impact of moderate-to-vigorous physical activity (MVPA) and sedentary leisure behavior (SLB) on stroke outcomes. MVPA exposures included self-reported activity and accelerometer-derived measures (e.g., leisure time MVPA ≥425 mg), while SLB included television, screen time, sitting, etc. Key outcomes of interest were any stroke and ischemic stroke events. Random-effects models were used for meta-analysis and heterogeneity was assessed with the I2 statistic. Leave-one-out sensitivity analyses were performed to ensure robustness of the results. Results: Six studies met inclusion criteria. Genetically predicted MVPA was associated with a lower risk of stroke (pooled OR = 0.73; 95% CI: 0.53–1.01; p = 0.06), though the result was not statistically significant (I2= 79.5%). In contrast, SLB showed a significant association with increased stroke risk (pooled OR = 1.15; 95% CI: 1.01–1.31; p = 0.03; I2 = 89.9%). Sensitivity analyses confirmed that findings were not influenced by any single study. Conclusion: These findings support a causal association between SLB and increased stroke risk, with suggestive but non-significant evidence for MVPA’s protective role. Despite significant association, high heterogeneity warrants conscious interpretation of findings. Further MR studies using standardized exposure definitions and updated genetic data are needed to strengthen the results.

Background: Contemporary data on trends in survival after incident atrial fibrillation (AF) are limited. Methods: Residents of a 27-county area in southern Minnesota and western Wisconsin with new-onset atrial fibrillation or atrial flutter between 2013 and 2023 were identified. An electronic algorithm requiring 1 inpatient code or 2 outpatient codes separated by >7 days but within 1 year was used to define AF. Patients were followed for all-cause mortality through March 31, 2025. Standardized mortality ratios of observed versus expected survival were calculated, and time trends in survival were examined using Cox regression adjusting for demographics, cardiovascular risk factors, comorbid conditions, and area-level measures of socioeconomic status and rurality. Results: There were 44,930 individuals identified with incident AF from 2013-2023 (56.4% male; mean (SD) age 72.8 (13.5) years; 95.8% were non-Hispanic white). Within the first 90 days, the risk of all-cause mortality was greatly elevated compared with individuals of a similar age and sex distribution in the general population (standardized mortality ratios 12.6, 95% CI, 12.1-13.0 and 3.8, 95% CI, 3.6-4.0 for the first 30 days and 31 to 90 days after diagnosis, respectively). This excess risk was observed for all age groups but was greatest in the youngest age group (standardized mortality ratios among 18-64 year olds for the first 30 days: 49.9, 95% CI, 44.6-55.7 and 31 to 90 days: 11.1, 95% CI: 9.4-13.1; Figure ). In the youngest age group, the excess risk persists through 5 years post AF, however, in the oldest age group the excess risk only persisted through 1 year. Survival within the first 90 days improved over the study period (adjusted hazard ratio [aHR], 0.88; 95% CI, 0.79-0.99 for 2023 vs 2013); likewise, among 90-day survivors, survival improved between 2013 and 2023 (aHR,0.82; 95% CI, 0.76-0.88). These trends were driven by improvements in the younger age groups, particularly for death among 90-day survivors (aHR for 18-64 years, 0.66, 95% CI, 0.52-0.83; 65-74 years: 0.77, 95% CI: 0.65-0.90; 75-84 years, 0.84, 95% CI: 0.75-0.95; 85+ years, 0.99, 95% CI: 0.98-1.01). Conclusion: In a Midwestern community, the excess risk of death is high within the first 90 days after incident AF. Furthermore, survival after AF has improved between 2013 and 2023, with the improvement greatest in younger age groups.

Objective: To test the effect of physical activity on the gut microbiome and circulating short chain fatty acids among sedentary overweight/obese adults with prediabetes. We hypothesized that randomization to increased physical activity would result in gut microbiome changes. Methods: \We randomized 77 adults with prediabetes and a sedentary lifestyle into one of two groups: 1) Intervention Group: Invited to engage in home-based moderate intensity walking 3x/week for 30 minutes/session in weeks 1-4 and for 45 minutes/session during weeks 5-8 of the 8-week intervention; or 2) Control Group: Maintained habitual physical activity levels. We performed metagenomic sequencing from stool collected at baseline, week 4, and week 8, with short-chain fatty acids (SCFA) measured from serum collected at baseline and week 8. Taxonomic and functional profiling were performed on the metagenomic reads; alpha diversity metrics were subsequently derived. Linear regression assessed the difference in change between the intervention and control groups for alpha-diversity and SCFA levels. Results: We screened 1,533 participants for eligibility and consented 132. Of these, 87 entered the run-in phase and 77 were randomized. Participants were 51.4±8.9 years old, 87.7% female, and 74% non-Hispanic White. Mean fasting glucose was 103.3±13.2 while mean BMI was 34.4±5.7. In comparison to the control group, the intervention group experienced decreased alpha diversity as characterized by Shannon, Richness, and Faith’s diversity indices by week 8 of the intervention (P<0.05). SCFA levels trended towards improvement in the intervention group, but the results were not statistically significant. Functional analysis of KEGG ontologies revealed themes consistent with a microbiome with enhanced metabolic activity and host-relevant metabolic signaling (Figure). Conclusions: Randomization to a walking intervention resulted in modest gut microbiome changes among adults with overweight/obesity and prediabetes.

Introduction: Adolescent obesity is linked to significantly increased risk of cardiovascular and metabolic comorbidities. Exercise outcomes are often impaired in adolescents with obesity (AO), but it remains unclear whether this reflects compromised cardiovascular reserve or non-cardiovascular factors. This study aimed to characterize mechanisms of reduced exercise performance in AO using cardiopulmonary exercise testing (CPET). The secondary aim was to assess the contribution of excess weight burden by correcting for extra fat mass in AO through estimated standard body mass (eSBM). Methods: We retrospectively analyzed CPET data from asymptomatic AO, defined as BMI ≥ 30 (n = 94), and age-matched, normal-weight controls without obesity (n = 139). In a subset of AO (n = 47), % body fat was measured by bioelectric impedance analysis, and eSBM was calculated as if they have comparable % body fat to controls using median values by sex and age in US adolescents. CPET was performed with a cycle ergometer following a ramp protocol. Results: Both male and female AO exhibited higher resting HR (p < 0.001) while peak HR remained comparable to controls. Absolute peak oxygen consumption (VO2) was higher in female AO (p < 0.001), while males showed no difference. Absolute ventilatory anaerobic threshold (VAT) was elevated in AO in both sexes (p < 0.001). When indexed by total body weight, peak VO2, peak work rate (WR), and VAT were lower in both male and female AO (p < 0.001). Peak respiratory exchange ratio (RER), peak VO2/VAT, and peak WR/peak VO2 were also significantly reduced in AO (p < 0.001). When indexed by eSBM, peak VO2 normalized only in female AO; peak WR remained lower, but VAT normalized in AO of both sexes with overcorrection in females, suggesting comparable submaximal exercise performance to controls. Conclusion: Reduced exercise performance in AO appears characterized by elevated resting HR, early exhaustion near peak exercise (lower peak RER and peak VO2/VAT), and decreased work efficiency (lower peak WR/peak VO2). Indexing CPET parameters by eSBM revealed relatively normal cardiopulmonary performance in AO during submaximal exercise, suggesting that reduced performance primarily reflects premature, fatigue-driven termination of exercise due to excess weight burden rather than true cardiopulmonary compromise. Further study is needed to clarify factors contributing to the observed sex-specific differences in AO exercise performance.