Longitudinal Intravascular Antibody Labeling Identified Regulatory T Cell Recruitment as a Therapeutic Target in a Mouse Model of Lung Cancer.

Anticancer immunity is predicated on leukocyte migration into tumors. Once recruited, leukocytes undergo substantial reprogramming to adapt to the tumor microenvironment. A major challenge in the field is distinguishing recently recruited from resident leukocytes in tumors. In this study, we developed an intravascular Ab technique to label circulating mouse leukocytes before they migrate to tissues, providing unprecedented insight into the kinetics of recruitment. This approach unveiled the substantial role of leukocyte migration in tumor progression using a preclinical mouse model of lung adenocarcinoma. Regulatory T cells (Tregs), critical mediators of immunosuppression, were continuously and rapidly recruited into tumors throughout cancer progression. Moreover, leukocyte trafficking depended on the integrins CD11a/CD49d, and CD11a/CD49d blockade led to significant tumor burden reduction in mice. Importantly, preventing circulating Treg recruitment through depletion or sequestration in lymph nodes was sufficient to decrease tumor burden, indicating that Treg migration was crucial for suppressing antitumor immunity. These findings underscore the dynamic nature of the immune compartment within mouse lung tumors and demonstrate the relevance of a temporal map of leukocyte recruitment into tumors, thereby advancing our understanding of leukocyte migration in the context of tumor development.

Early-life caffeine exposure induces morphological changes and altered physiology in Caenorhabditiselegans.

Caffeine, a widely consumed stimulant, is known for its effects on alertness and fatigue reduction by blockade of adenosine receptors. While it holds therapeutic potential, its diverse impacts pose risks, particularly in early development. This study explores the developmental effects of caffeine exposure using Caenorhabditis elegans (C. elegans) as a model organism. We investigated morphological and behavioral changes induced by caffeine exposure at the L1 stage and assessed their impact at the L4 stage, which roughly corresponds to human infancy and adolescence, respectively. Caffeine-exposed worms displayed increased body length, body bends, and pharyngeal pumping rates compared to control worms. These findings indicate heightened food-seeking behavior and greater food intake, leading to the observed morphological changes. While caffeine did not affect other locomotor behaviors, its stimulatory effect on growth and development highlights its significance. This study provides insights into the potential impact of early-life caffeine exposure on long-term health and development, offering a foundation for future research in vertebrates to uncover its implications on metabolism and other metrics of health.

In vivo antibody labeling route and fluorophore dictate labeling efficiency, sensitivity, and longevity.

Leukocytes migrate through the blood and extravasate into organs to surveil the host for infection or cancer. Recently, we demonstrated that intravenous (IV) anti-CD45.2 antibody labeling allowed for precise tracking of leukocyte migration. However, the narrow labeling window can make this approach challenging for tracking rare migration events. Here, we show that altering antibody administration route and fluorophore can significantly extend the antibody active labeling time. We found that while both IV and intraperitoneal (IP) anti-CD45.2 antibody labeled circulating leukocytes after injection, they had different kinetic properties that impacted labeling time and intensity. Quantification of circulating antibody revealed that while unbound IV anti-CD45.2 antibody rapidly decreased, unbound IP anti-CD45.2 antibody increased over one hour. Using in vitro and in vivo serial dilution assays, we found that Alexa Fluor 647 (AF647) and Brilliant Blue 700 (BB700) dyes had the greatest labeling sensitivity compared to other fluorophores. However, IP antibody injection with anti-CD45.2 BB700, but not AF647, resulted in continuous blood leukocyte labeling for over 6 hours. Finally, we leveraged IP anti-CD45.2 BB700 antibody to track slower migrating leukocytes into tumors. We found that IP anti-CD45.2 antibody injection allowed for the identification of ~seven times as many tumor-specific CD8+ T cells that had recently migrated from blood into tumors. Our results demonstrate how different injection routes and fluorophores affect anti-CD45.2 antibody leukocyte labeling and highlight the utility of this approach for defining leukocyte migration in the context of homeostasis and cancer.

Torso injuries after fall from standing-empiric abdominal or thoracic CT imaging is not indicated.

PURPOSE: Falls from standing (FFS) have become the most common mechanism of injury at many trauma centers. Liberal imaging of low energy trauma has questionable value. We hypothesize that torso trauma intervention is rare in the FFS population, and physical examination sufficiently screens for torso injuries needing intervention. METHODS: We queried our ACS-verified Level 1 trauma center registry for falls from standing from 1/1/14 to 12/31/16. Exclusion criteria were: falls from height, falls associated with penetrating trauma, lack of an abdominal or chest CT, a Glasgow Coma Scale Score (GCS) less than 15, and surgical intervention at another facility prior to arrival at our center. Demographics, historical details, hemodynamics, injuries, injury severity, procedures, initial vital signs, and outcome were recorded. RESULTS: 1,654 patients had a FFS during our study period. 728 had an abdominal or chest CT and a GCS of 15 and comprised the evaluable population. Mean age was 56.5 years. 55.8% were female. The mortality rate was 8%. There were 179 chest injuries in 121 patients, and 54 abdominal injuries in 43 patients. 379 patients had a GCS of 15 and underwent thoracic CT, yet only 11 (3%) underwent intervention. The negative predictive value for physical exam was 100% for chest intervention. 349 patients had a GCS of 15 and abdominal CT, yet only 13 (3.7%) underwent procedural intervention. Abdominal physical exam had a negative predictive value of 99.7% for intervention, but when combined with vital signs, the value was 100%. CONCLUSION: Torso injuries in FFS are rare. Of our study population, 13 abdominal injuries underwent intervention, and 11 chest injuries underwent intervention. Screening patients by physical examination and vital signs is sufficient and safely allows for the use of selective abdominal and chest CT.

Financial, family, and social factors impacting on cardiac rehabilitation attendance.

BACKGROUND: Attendance in phase 2 cardiac rehabilitation program after acute myocardial infarction is poor. OBJECTIVE: To identify and explore the demographic factors that influence peoples' decisions to attend cardiac rehabilitation programs. METHODS: A descriptive-interpretive design was used. Semi-structured interviews were conducted with 10 people post infarction in Victoria, Australia after their first scheduled appointment to attend outpatient cardiac rehabilitation. The interview transcripts were thematically analysed. RESULTS: The perceived relevance of cardiac rehabilitation related to the context of people's lives, namely their financial, family and social situation, and how important program outcomes were seen to be relevant to this context. CONCLUSION: The findings of this study suggest that there are a proportion of people unlikely to attend outpatient cardiac rehabilitation programs following an AMI despite encouragement to attend. It may be unrealistic to aim for 100% referral and uptake into cardiac rehabilitation programs and therefore an inappropriate endpoint by which to evaluate such programs.