Citations

The immunosuppressive tumor microenvironment (TME) remains a major barrier to effective cancer immunotherapy. Among the central regulators of immune suppression, CD38, a multifunctional ectoenzyme and surface glycoprotein, has emerged as a pivotal orchestrator. CD38 is abundantly expressed on regulatory T cells (Tregs), regulatory B cells (Bregs), myeloid-derived suppressor cells (MDSCs), tumor-associated macrophages (TAMs), and tumor-associated neutrophils (TANs), where it enhances survival, metabolic fitness, and suppressive activity. Invariant natural killer T (iNKT) cells, which can either promote or suppress antitumor immunity, also express CD38 upon activation, suggesting a role for CD38 in directing their context-dependent fate within the TME. Mechanistically, CD38 regulates immune suppression through NAD + hydrolysis, calcium signaling, and promotion of fatty acid oxidation (FAO) while impairing effector T-cell glycolysis and mitochondrial fitness under chronic hypoxia—conditions that favor exhaustion rather than enhanced cytotoxicity. By depleting extracellular NAD + , CD38 diminishes glycolysis and mitochondrial oxidative phosphorylation in effector T cells, while sustaining regulatory cell persistence through FAO. Its enzymatic products, cyclic ADP-ribose (cADPR) and NAADP, further mobilize calcium fluxes that reinforce suppressive function. CD38 also integrates with hypoxia-driven pathways; in CD38 + Bregs, stabilization of HIF-1α and induction of FAO-related genes such as CPT1A and PPARα/γ promote angiogenesis, immune-evasion, and therapeutic resistance. Therapeutically, targeting CD38 with monoclonal-antibodies, small-molecule inhibitors, or combinations with checkpoint blockade and macrophage-reprogramming agents has shown promise. Such interventions reverse immune suppression, restore effector T cell activity, and enhance tumor responsiveness to immunotherapy. In summary, CD38 functions as both a metabolic regulator and an immunologic checkpoint, coordinating suppressive networks and shaping iNKT cell fate. These multifaceted roles position CD38 as a transformative target for next-generation immunotherapies.

Context: Testosterone is a steroid hormone produced primarily in the testes in men and ovaries in women, playing crucial roles in androgenic, anabolic, and psychological functions, including muscle growth, bone formation, erythropoiesis, risk-taking, and aggression, making it important for athletes. Sports performance is linked closely to testosterone level, prompting athletes to explore legal and illegal ways to boost testosterone. This review examines testosterone physiology and legal strategies for optimizing testosterone levels in athletes, as well as their practical applications. Evidence Acquisition: Database search. Study Design: Narrative review. Level of Evidence: Level 5. Results: Maintaining healthy testosterone levels requires energy balance and optimal nutrition with adequate macronutrients and micronutrients, especially for athletes prone to dieting and food restriction. Testosterone boosters are marketed widely but lack strong evidence for efficacy and may pose risks. While some substances show promise, further research is needed. Sleep is critical as testosterone secretion is linked to the rapid eye movement phase, highlighting the need for proper sleep hygiene and addressing sleep disorders. Moderate-to-high intensity free-weight resistance exercises are most effective for increasing testosterone, while the effects of sexual activity remain unclear. Endocrine-disrupting chemicals can lower testosterone levels and should be avoided. While cold-water immersion may decrease testosterone, sauna bathing appears to be neutral. Radiofrequency electromagnetic radiation from modern electronic devices may harm the hypothalamic-pituitary-gonadal axis, warranting limited use. Over-the-counter analgesics, such as nonsteroidal anti-inflammatory drugs and acetaminophen, may decrease testosterone levels, suggesting cautious use. Seasonal changes in testosterone levels require further study. Testosterone-optimizing strategies excluding banned substances may aid in treating functional low testosterone or reducing harm in anabolic-androgenic steroid users. Conclusion: Educating athletes on safe and effective strategies to increase testosterone is crucial, with ongoing research needed to explore additional methods. Strength-of-Recommendation Taxonomy: B.

ABSTRACT Background Several colorectal cancer (CRC) screening modalities are guideline-recommended in the United States, yet they vary considerably in screening interval and real-world adherence. As a result, single-round test performance may not reflect cumulative effectiveness over time. This study compared the 10-year longitudinal outcomes of two CRC screening strategies— triennial next-generation multitarget stool DNA testing (ng mt-sDNA) and decennial screening colonoscopy. Methods This study used the validated, microsimulation-based Colorectal Cancer and Adenoma Incidence and Mortality (CRC-AIM) model to estimate 10-year cumulative outcomes for two guideline-recommended screening strategies: triennial ng mt-sDNA and decennial colonoscopy. Model inputs included test-specific performance and real-world adherence. Outcomes included CRC and precancerous lesions detected, CRC mortality reductions, and life-years gained (LYG). Sensitivity analyses examined the effects of varying both screening adherence and follow-up colonoscopy adherence. Results Over 10 years per 1,000 individuals offered screening, the ng mt-sDNA screening test detected 13% more precancerous lesions and 11% more CRC cases than colonoscopy, with a greater proportion of CRCs identified through screening rather than symptomatic detection. ng mt-sDNA resulted in greater CRC mortality reduction (33% vs 20%) and 62% more life-years gained, with consistent findings across sensitivity analyses. Conclusions With real-world adherence, screening with triennial ng mt-sDNA demonstrates superior cumulative effectiveness compared with decennial colonoscopy, driven by higher adherence and favorable longitudinal performance. These findings support the expanded use of noninvasive stool-based screening to reduce CRC mortality and alleviate capacity constraints associated with colonoscopy-based screening. Broader adoption of ng mt-sDNA may enhance population-level CRC prevention by increasing participation and improving early detection across the screening eligible population. Plain language summary Colorectal cancer screening tests are recommended at different time intervals and completed at different adherence rates in clinical practice. The analysis used a validated simulation model to compare 10-year outcomes of triennial next-generation multi-target stool DNA test (ng mt-sDNA) with a single colonoscopy, accounting for real-world screening and follow-up colonoscopy adherence. Our findings indicate that repeated ng mt-sDNA provides greater cumulative screening effectiveness than colonoscopy over a 10-year period.

BACKGROUND: Recent randomized trials have demonstrated that for patients with severe tricuspid regurgitation (TR), transcatheter tricuspid valve interventions (TTVI) improve patients’ symptoms, function, and quality of life and that the amount of health status improvement correlates with the extent of TR reduction. Defining this relationship in greater detail can potentially provide insight into device selection and patient-specific treatment goals. We therefore sought to better understand the relationship between both baseline TR severity and change in TR after TTVI and the extent of improvement in health status after TTVI. METHODS: As part of the Tri-QOL (Kansas City Cardiomyopathy Questionnaire Validation in Tricuspid Valve Disease) study, data from 11 studies of TTVI devices were transferred to the US Food and Drug Administration to harmonize and anonymize before analysis by an independent center. This secondary, observational analysis used patient-level data from the 6 single-arm studies of patients who underwent TTVI to explore the association of change in KCCQ-OS with TR grade using multivariable models, adjusted for age, sex, chronic lung disease, and baseline KCCQ-OS. The primary model included TR grade at baseline, TR grade at 1 month, and the interaction between the two. RESULTS: Among 1056 patients with ≥severe TR who underwent TTVI, mean age was 79.1±7.1 years, 60.3% were female, and mean baseline Kansas City Cardiomyopathy Questionnaire-overall summary score [KCCQ-OS] was 49.5±22.3. Baseline TR grade was severe in 33.5%, massive in 35.9%, and torrential in 30.6%. One-month after TTVI, TR was none/trace in 21.7%, mild in 27.2%, moderate in 28.1%, and ≥evere in 23.1%, while the mean change in KCCQ-OS was 17.0±21.3 points. In a multivariable model that included TR grade at baseline, TR grade at 1 month, and their interaction, there was a strong association between reduction in TR and improvement in KCCQ-OS, with no consistent evidence of a threshold of TR grade below which there was no further improvement in KCCQ-OS. However, among patients with baseline torrential TR, the extent of health status improvement plateaued for patients achieving moderate or less TR at 1 month (ie, a 3-grade improvement from baseline). CONCLUSIONS: Health status improvement after TTVI was most strongly associated with the degree of TR reduction, although there was minimal additional improvement for most patients beyond a 3-grade reduction in TR. These findings support the goal of achieving mild or less TR with TTVI, although patients with torrential TR at baseline may be well served if moderate TR can be achieved.