Citations

Abstract Rationale Alpha1-antitrypsin (AAT; gene name SERPINA1) is a critical antiprotease that protects the lung from neutrophil elastase-mediated injury. AAT deficiency predisposes to emphysema, which is further exacerbated by cigarette smoke (CS) exposure. We previously reported (PMID: 38325750) that a nebulized human platelet-derived exosome product (PEP) attenuated CS-induced emphysema in C57BL/6 mice. Given the presence of AAT protein in these platelet-derived exosomes (identified by proteomics), we hypothesized that PEP nebulization would significantly attenuate both spontaneous and CS-induced emphysema in SERPINA1 knockout (KO) mice. Methods Transgenic SERPINA1 KO C57BL/6 mice (both sexes) exposed to CS (10 cigarettes/day and 5 days/week) for 2 months were then randomized to receive nebulized PEP or 0.9% saline (placebo) twice weekly for 4 additional weeks, with continued CS exposure. PEP was reconstituted in 0.9% saline (22.7mg/mL; ∼3 × 10¹0 vesicles/mL) and administered via pressure- and humidity-controlled nose-only inhalation tower (2.25 mL of PEP or saline over 35 minutes). Lung static compliance (Cst), cutaneous O2 saturation, mean linear intercepts (Lm), and plethysmographic parameters were measured during and after the study. Results Histological analysis of the lung tissue sections revealed that PEP significantly attenuated the CS-induced increase in alveolar size, as determined by measurement of the mean linear intercepts (Lm, p < 0.001). Lung static compliance (Cst), which was increased in CS-exposed mice, was also significantly decreased in the PEP-treated group (p < 0.001) compared to placebo in the male and female combined group. Functional respiratory parameters further supported the protective effect of PEP in this AAT-deficient model. In female mice, PEP nebulization significantly improved several CS-impaired pulmonary function parameters, including minute volume (MV, p = 0.024), the flow at the point 50% of tidal volume is expired (EF50, p = 0.021), Peak Inspiratory Flow (PIF, p = 0.009), Peak Expiratory Flow (PEF, p = 0.018), and O2 saturation (p = 0.035). However, these improvements were not observed in male mice. Conclusions These findings extend prior observations and underscore the therapeutic potential of nebulized AAT-enriched PEP directly to the alveolar region, effectively attenuating injury and improving pulmonary function in AAT deficiency-related emphysema. This abstract is funded by: Department of Defense, Mayo Clinic Funding, The Young and Middle-aged Medical High-end Talents in Chongqing Program

Abstract Introduction We previously demonstrated that nebulized platelet-derived exosome product (PEP) alleviates cigarette smoke (CS)-induced murine emphysema. To elucidate the underlying molecular mechanisms, we conducted single-nucleus RNA sequencing of lung tissue, which initially revealed a shift in the cell source for TNF signaling (a critical regulator of inflammation in COPD lungs) from innate lymphoid cells (ILC) to alveolar macrophages (aMac) after chronic CS exposure. In this study, we conducted a more in-depth analysis of cellular communication to determine the mechanism by which PEP modulates CS-induced TNF signaling in the lung microenvironment. Methods Single-cell transcriptomics and cell-cell communication analyses were performed between CS-exposed placebo control lungs vs. sham control lungs and CS-exposed PEP-treated vs. placebo control lungs using R packages, including Seurat, CellChat, Patchwork, Future, and NMF. A comparative analysis of ligand-receptor interactions across these datasets was conducted using CellChat to infer intercellular signaling networks. Results Single-nuclear RNA-seq analysis revealed that the Thy1-ITGAX_ITGB2 signaling pathway was significantly upregulated by CS, acting as the adhesive and activating bridge that facilitates the switch in TNF production from ILC to aMac. Thy1 is a GPI-anchored ligand expressed on ILCs, and ITGAX_ITGB2 is its cognate receptor on aMacs. Concurrently, Ptprc-Mrc1 signaling, an inhibitory pathway in ILC-aMac crosstalk, was downregulated, contributing to sustained aMac activation by CS. Furthermore, analysis of aMac-aMac interactions revealed upregulated GRN/Sort1 signaling, which promotes the internalization of progranulin, an anti-inflammatory glycoprotein that competes for TNF/TNFR signaling. Ptprc-Mrc1 signaling was also downregulated within the aMac autocrine/paracrine network, further perpetuating a pro-inflammatory state. In contrast, treatment with PEP downregulated Thy1-ITGAX_ITGB2 signaling and upregulated Lamc1-Cd44 signaling, a hallmark of aMac deactivation, thereby inducing a phenotypic switch in inflammatory macrophages toward a reparative M2 state, promoting the resolution of CS-induced chronic inflammation. Conclusions These data suggest that the transition of TNF production from ILCs to aMacs under chronic CS stress is driven by increased Thy1-ITGAX_ITGB2 interactions and decreased Ptprc-Mrc1 signaling between ILCs and aMacs crosstalk within the local tissue. Enhancing the crosstalk between Lamc1-Cd44 and Ptprc-Mrc1 may suppress TNF production and attenuate CS induced aMac activation. Targeting these pathways, as demonstrated by nebulized PEP treatment, holds therapeutic potential to deactivate inflamed aMacs and promote homeostasis in the inflamed lung. This abstract is funded by: Department of Defense, Mayo Clinic Funding

Background: Several special tests for detecting medial ulnar collateral ligament (MUCL) injuries of the elbow have been described, but data on the clinical utility of these tests are limited. Purpose: To determine the clinical utility of selected elbow special tests to detect MUCL injuries in an athletic population. Study Design: Cross-sectional study; Level of evidence, 3. Methods: A total of 84 consecutive patients with sports-related elbow pain underwent a standardized clinical examination. Overall, 6 special tests (moving valgus stress test, static valgus stress test, modified valgus stress test, milking maneuver, pronation flexion resistance test, and temple/cheek press test) were performed. Sensitivity, specificity, accuracy, positive/negative predictive value, and positive/negative likelihood ratio (LR+ and LR–, respectively) were calculated for individual tests and combinations of tests to detect MUCL injuries. Higher values for the LR+ and lower values for the LR– represent stronger clinical utility. Results: For detecting MUCL injuries, the moving valgus stress test resulted in the highest sensitivity (98%) and accuracy (93%) with the lowest LR– (2%). The milking maneuver had the highest LR+ (5.1) with the second highest sensitivity (77%) and accuracy (79%). The pronation flexion resistance test and the temple/cheek press test had the lowest LR+ (1.5 and 1.8, respectively) and highest LR– (94% and 95%, respectively) in addition to the lowest sensitivity (16% and 9%, respectively) and accuracy (33% and 30%, respectively). No combination of tests resulted in increased clinical utility. Conclusion: The moving valgus stress test and milking maneuver demonstrated acceptable clinical utility in which the moving valgus stress test was better for ruling out MUCL injuries and the milking maneuver was better at ruling in MUCL injuries. There was no added value when combining the 2 tests together or with other maneuvers.

Abstract Glioblastoma (GBM), isocitrate dehydrogenase wild-type (IDHwt) and central nervous system diffuse large B-cell lymphoma (CNS-DLBCL) are aggressive brain tumors with overlapping MRI features, yet distinct treatment approaches. Noninvasive tools are needed to aid in differential diagnosis. Deep learning on T1 postcontrast and T2-weighted MRI sequences were used to differentiate GBM and CNS-DLBCL. A three-stage temporal study design was utilized. Model development was performed on 146 patients with CNS-DLBCL and 146 age-matched, sex-matched, and MRI year–matched patients with GBM diagnosed at Mayo Clinic between 1998 and 2019. Models were tested on independent temporal test cohorts. Initial testing included 240 independent GBM diagnosed at Mayo Clinic between 1998 and 2019. The prospective test cohort included 37 patients with CNS-DLBCL and 256 patients with GBM diagnosed at Mayo Clinic after January 1, 2020, and 36 patients with CNS-DLBCL diagnosed at an external institution. Of the patients diagnosed at Mayo Clinic, 47% had MRIs generated from non-Mayo institutions. Two different model approaches were compared: (i) ensemble approach using area under the receiver operating characteristic curve (AUC) and cross-validation for model selection and (ii) loss approach minimizing cross-entropy loss and cross-validation to evaluate prediction performance. The AUCs on the prospective test cohort were 0.84 [95% confidence interval (CI), 0.78–0.90] and 0.83 (95% CI, 0.77–0.88) for the ensemble and loss approaches, respectively. Stability of ensemble prediction improved with the increasing number of models. Stratified AUC analysis demonstrated consistent performance across sex and age. We utilized a robust temporal study design and applied 2 different analytic approaches to develop a classification model. The findings confirm the feasibility of using MRI-based deep learning models to differentiate GBM from CNS-DLBCL. Significance: GBM, IDHwt and CNS-DLBCL are aggressive brain tumors with overlapping MRI features, yet distinct treatment approaches. Noninvasive tools are needed to aid in differential diagnosis. We developed MRI-based deep learning models to differentiate GBM, IDHwt from CNS-DLBCL using a rigorous three-stage temporal design that included prospective validation. The model AUC on a prospective cohort was 0.84.

Abstract Background Postoperative spinal implant infections (PSIIs) are a serious complication of instrumented spinal fusion. Although debridement with implant retention is standard for early infection, the optimal duration of antimicrobial therapy remains uncertain. Methods We conducted a multicenter retrospective cohort study across 10 US academic centers, including adults with early PSII (≤90 days after fusion surgery) from 2017 to 2021. We excluded patients who experienced treatment failure within 6 weeks of debridement. The primary outcome was treatment failure. Antibiotic therapy effect was analyzed as a time-varying exposure using adjusted Cox proportional hazards models. Secondary analyses included 12-week landmark and clone-censor-weighted models to compare durations ≤ 12 weeks versus >12 weeks. Results A total of 116 patients out of 499 (23.2%) experienced treatment failure during a median follow-up of 3.2 years. Among patients who remain failure-free 6 weeks from debridement, being on antibiotics was not associated with treatment failure (adjusted hazard ratio [aHR] 0.71; 95% CI .48–1.07; P = .10). In a 12-week landmark analysis limited to 359 patients who were not on indefinite suppressive antibiotic therapy, treatment durations > 12 weeks did not significantly reduce the risk of failure (aHR 1.01; 95% CI .62–1.64; P = .99). Results were consistent in the clone-censor-weight sensitivity analysis (aHR 0.85; 95% CI .62–1.16; P = .30). Conclusions Prolonged antibiotic therapy was not associated with improved outcomes in early PSII managed with debridement and implant retention. These results support shorter, individualized antibiotic courses in patients with adequate surgical source control.

Introduction: Heart failure (HF) with preserved ejection fraction (HFpEF) is now the predominant HF subtype, largely driven by the syndemic of physical inactivity and overweight/obesity in an aging population. Deranged skeletal muscle energetics and regional ectopic adipose depots are key cardiometabolic pathways in the pathogenesis of HFpEF, both of which may be favorably modified by 1-2 hours/week of resistance exercise (RE). However, its association with HFpEF risk has not been thoroughly examined. We investigated the association between midlife RE behaviors and incident HFpEF in the Atherosclerosis Risk in Communities (ARIC) study. Hypothesis: Participation in RE at midlife is inversely associated with the risk of incident HFpEF. Methods: Our exposure (RE)—including weightlifting and bodyweight resistance exercises—was assessed using the validated Baecke questionnaire and reported weekly RE duration was averaged across Visits 1 and 3 (1987-1995). We dichotomized averaged RE as 0 hr/wk (‘No RE’, reference) and >0 hr/wk (‘Any RE’). Our outcome (incident HFpEF) was identified through committee-adjudicated HF hospitalizations (January 1, 2005 to December 31, 2023) using medical chart abstraction. Participants with prevalent HF, death, or loss to follow-up before January 1, 2005 were excluded. We constructed Cox regression models to evaluate the association between midlife RE and incident HFpEF. Model 1 adjusted for age, sex, race, field center, education, smoking status, alcohol consumption, and non-RE physical activity. Given that adiposity may lie on the causal pathway, waist-height ratio (WHtR; both measured in cm) was added in Model 2. Results: 10,751 Black and White participants (803 incident HFpEF cases) were analyzed over a median follow-up time of 14.4 years (mean±SD Visit 1 age, 53.3±5.6 years; average Visit 1 and 3 WHtR, 0.58±0.08; 24.7% Black; 57.4% female). 1,217 participants (11.3%) reported engaging in RE at Visits 1 and/or 3, with a median duration of 0.84 hr/wk (IQR, 0.50-1.61). Compared to No RE, the fully adjusted hazard ratio (HR) for Model 1 for Any RE was: 0.78 (95% CI, 0.61-1.00, P = 0.05). The association was attenuated after adjustment for WHtR: HR = 0.84 (0.65-1.07, P = 0.16). Conclusion: Participation in RE at midlife is associated with a 22% lower risk of incident HFpEF. To inform public health and clinical guidelines, further studies are needed to clarify the role of RE in HFpEF prevention.

Background: Stable osteochondritis dissecans (OCD) lesions are primarily treated nonoperatively. Nonoperative treatment includes several recommendations, including the use of an unloader brace. However, little is known about the clinical effectiveness of unloader bracing and its influence on OCD healing, return to sports, and patient-reported outcomes (PROs). The purpose of this investigation was to evaluate the impact of unloader bracing on patients with stable medial femoral condyle (MFC) OCD lesions treated nonoperatively. Purpose: To investigate the influence of valgus unloader bracing on the success of treating stable MFC OCD with nonoperative treatment strategies. Study Design: Cohort study; Level of evidence, 2. Methods: The authors used a prospective cohort of patients receiving nonoperative care for stable MFC knee OCD lesions. The primary variable of interest was the efficacy of bracing. The primary outcomes were transition from nonoperative care to surgical intervention, return-to-play (RTP) clearance, and PROs. Bivariate testing was used to determine if there were differences between groups. Chi-square testing was used to determine if there were differences in rates of transition to surgery by group. The timing of the transition by each group was assessed using a Wilcoxon rank-sum test, given the nonparametric nature of the data. Kaplan-Meier survival analysis was used to calculate time at risk, incidence rate, and survival times for each group. Results: A total of 185 knees (bracing group: 123 [66.5%] knees; no-bracing group: 62 [33.5%] knees) were analyzed. Overall, 142 (76.8%) knees were successfully treated nonoperatively. Transition to surgery occurred in 43 (23.2%) knees. There were no differences in transition to surgery by groups, with no differences seen by group. Of the knees that did not transition to surgical care, 65 (71.4%) in the bracing group and 38 (74.5%) in the no-bracing group received RTP clearance ( P = .693). PRO scores were similar between the 2 groups at the time of RTP clearance. Conclusion: The inclusion of an unloader brace in the nonoperative treatment for stable MFC OCD lesions did not decrease the likelihood of patients undergoing surgical intervention or improve their PRO scores at the time of RTP clearance. Registration: NCT02771496 (ClinicalTrials.gov identifier).

The focus of this review is the clinical and pathologic presentations of hereditary cancer syndromes with cutaneous manifestations, with the goal of providing a reference for the multidisciplinary care teams involved in the diagnosis and management of these conditions. Advancements in genomics have led to newly recognized syndromes and a deeper understanding of established syndromes. We focus on those with the most relevant cutaneous manifestations. Clinical and histopathologic images provide visual context for these findings, many of which are rare. We summarize the established literature and incorporate new research and noteworthy case reports.

Abstract Echocardiography is the most widely used cardiac imaging modality, yet artificial intelligence-enabled interpretation remains limited by the inability of existing models to integrate visual assessment, quantitative measurement, and clinical reasoning within a unified framework. Here we present EchoAtlas, the first autoregressive vision-language model developed for echocardiographic interpretation. Trained on over 12.9 million question-answer pairs derived from approximately 2 million echocardiogram videos, EchoAtlas achieves 0.966 accuracy on multiple-choice questions in our internal test set and establishes a new state-of-the-art on the public MIMIC-EchoQA benchmark (0.699 vs. 0.508 previously). EchoAtlas also provides accurate quantitative measurements, segment-level regional wall motion assessment, longitudinal comparison, and diagnostic reasoning across diverse question formats — capabilities not previously demonstrated in this domain. These results highlight the potential of autoregressive vision-language models as a foundation for interactive echocardiographic interpretation, representing an early step toward scalable, auditable artificial intelligence systems in cardiology practice.