MERTK inhibition selectively activates a DC - T-cell axis to provide anti-leukemia immunity.

TAM-family tyrosine kinases (TYRO3, AXL and MERTK) are potential cancer therapeutic targets. In previous studies MERTK inhibition in the immune microenvironment was therapeutically effective in a B-cell acute leukemia (B-ALL) model. Here, we probed anti-leukemia immune mechanisms and evaluated roles for TYRO3 and AXL in the leukemia microenvironment. Host Mertk knock-out or MERTK inhibitor MRX-2843 increased CD8α+ dendritic cells (DCs) with enhanced antigen-presentation capacity in the leukemia microenvironment and inhibited leukemogenesis. High MERTK or low DC gene expression were associated with poor prognosis in pediatric ALL patients, indicating the clinical relevance of these findings. MRX-2843 increased CD8+ T-cell numbers and prevented induction of exhaustion markers, implicating a DC - T-cell axis. Indeed, combined depletion of CD8α+ DCs and CD8+ T-cells was required to abrogate anti-leukemia immunity in Mertk-/- mice. Tyro3-/- mice were also protected against B-ALL, implicating TYRO3 as an immunotherapeutic target. In contrast to Mertk-/- mice, Tyro3-/- did not increase CD8α+ DCs with enhanced antigen-presentation capacity and therapeutic activity was less dependent on DCs, indicating a different immune mechanism. Axl-/- did not impact leukemogenesis. These data demonstrate differential TAM kinase roles in the leukemia microenvironment and provide rationale for development of MERTK and/or TYRO3-targeted immunotherapies.

A required medical student collaborative case presentation with a pathologist in the surgery clerkship.

In medical education, pathology has traditionally been concentrated in only the preclinical years, often without sufficient emphasis on its practical application in clinical practice. Correspondingly, medical students' interest in pathology as a career has been low. To address this issue and foster a deeper understanding of pathology's clinical relevance and encourage appropriate utilization, we introduced a required exposure to pathology in the surgery clerkship featuring clinicopathological case review in a small group setting. Unlike other approaches, we wanted to create a program that concentrates on pathology cases directly linked to patients whom students cared for during their clerkship rotation, emphasizing the relevance of pathology diagnosis. Feedback has been overwhelmingly positive from participating students, who report an increased awareness of pathology's importance in patient management and of the significance of interdisciplinary collaboration between pathologists and clinicians. A notable feature of this program is its relatively low time and personnel requirements, which facilitate inclusion in the busy clerkship and acceptance in the Department of Pathology. Challenges, such as timely case selection and administrative co-ordination, are being addressed to optimize the program's implementation. In the future, we are considering expanding this model to other clerkships. By rekindling interest in pathology through practical engagement and highlighting its real-world relevance, this approach offers a promising strategy to counteract recruitment challenges in this crucial medical field.

When Walter Freeman Came to Town: The Prefrontal Lobotomy at Rochester State Hospital.

In the United States, frontal lobe lesioning procedures have been uniformly linked to the neurologist Walter Freeman, although the prefrontal lobotomy was investigated in other institutions in the United States, the United Kingdom, Europe, Russia, Japan, and China, mostly in patients with psychosis, obsessive-compulsive disorder, and/or intractable pain syndromes. These procedures were based on earlier reports of improvement of psychiatric symptoms after surgical resection of frontal lobe tumors and led many to infer a causal relationship between frontal lobe dysfunction and abnormal behavior. Freeman first visited Rochester, MN, as a medical student in a gastrointestinal laboratory at the Mayo Clinic. Freeman visited Rochester again many years later, a visit that was received with trepidation but ultimately led to the adoption of his lobotomy method. Freeman's grandfather, W.W. Keen, was a highly respected surgeon credited with the first successful surgical resection of a benign brain tumor in the United States, a connection that may have contributed to Freeman's subsequent interest in performing lobotomies. Keen maintained a close relationship with the Mayo brothers and also advocated for Freeman's initial visit to the Mayo Clinic. In this article, we present a brief historical review of Freeman and the early reports of the prefrontal lobotomy procedure performed by consultants affiliated with the Mayo Clinic and Rochester State Hospital.

Gestational and postnatal exposure to wildfire smoke and prolonged use of respiratory medications in early life.

As wildfire frequency and severity increases, smoke exposures will cause increasingly more adverse respiratory effects. While acute respiratory effects of smoke exposure have been documented in children, longer term sequelae are largely unstudied. Our objective here was to examine the association between gestational and postnatal exposure to wildfire smoke and prolonged use of prescription medication for respiratory conditions in early childhood. Using Merative MarketScan claims data, we created cohorts of term children born in western states between 1 January 2010-31 December 2014 followed for at least three years. Using NOAA Hazard Mapping System data, we determined the average number of days a week that >25% of the population in a metropolitan statistical area (MSA) was covered by smoke within each exposure period. The exposure periods were defined by trimester and two 12 week postnatal periods. Medication use was based on respiratory indication (upper respiratory, lower respiratory, or any respiratory condition) and categorized into outcomes of prolonged use (⩾30 d use) (PU) and multiple prolonged uses (at least two prolonged uses) (MPU). We used logistic regression models with random intercepts for MSAs adjusted for child sex, birth season, and birth year. Associations differed by exposure period and respiratory outcome, with elevated risk of MPU of lower respiratory medications following exposure in the third trimester and the first 12 postnatal weeks (RR 1.15, 95% CI 0.98, 1.35; RR 1.21, 95% CI 1.05, 1.40, respectively). Exposure in the third trimester was associated with an increase in MPU of any respiratory among males infants only (male RR 1.22, 95% CI 1.00, 1.50; female RR 0.93, 95% CI 0.66, 1.31). Through novel use of prescription claims data, this work identifies critical developmental windows in the 3rd trimester and first 12 postnatal weeks during which environmental inhalational disaster events may impact longer-term respiratory health.

Unveiling the intricate role of S100A1 in regulating RyR1 activity: A commentary on "Structural insights into the regulation of RyR1 by S100A1".

S100A1, a calcium-binding protein, plays a crucial role in regulating Ca2+ signaling pathways in skeletal and cardiac myocytes via interactions with the ryanodine receptor (RyR) to affect Ca2+ release and contractile performance. Biophysical studies strongly suggest that S100A1 interacts with RyRs but have been inconclusive about both the nature of this interaction and its competition with another important calcium-binding protein, calmodulin (CaM). Thus, high-resolution cryo-EM studies of RyRs in the presence of S100A1, with or without additional CaM, were needed. The elegant work by Weninger et al. demonstrates the interaction between S100A1 and RyR1 through various experiments and confirms that S100A1 activates RyR1 at sub-micromolar Ca2+ concentrations, increasing the open probability of RyR1 channels.

Urinary Response to Consuming Plant-Based Meat Alternatives in Persons with Normal Kidney Function: The SWAP-MEAT Pilot Trial.

BACKGROUND: Consuming excess animal meat may exacerbate kidney disorders such as urinary stone disease and chronic kidney disease. Plant-based meat alternatives imitate animal meat, and replace animal with vegetable protein, but it is unclear whether eating plant-meat confers similar health benefits as eating whole vegetables. We hypothesized that eating plant-meat when compared with animal meat decreases dietary acid load but increases dietary phosphorus and nitrogen. METHODS: SWAP-MEAT was a randomized eight-week, crossover trial (NCT03718988) of participants consuming >2 servings/day of either plant-meat or animal meat for each eight-week phase. We measured urine sulfate, ammonium, pH, phosphorus, urea nitrogen, citrate, and creatinine concentrations, and serum creatinine and bicarbonate concentrations from stored participant samples from each phase. RESULTS: At a single site, we enrolled 36 generally healthy participants (mean±SD age 50.2 ± 13.8 years, 67% women, and 69% White). Eating the plant-meat diet vs. eating the animal meat diet was associated with lower mean concentration of urine sulfate (-6.7 mEq/L; 95% CI -11.0, -2.4), urine ammonium (-4.2 mmol/L; 95% CI -8.2, -0.1), urine phosphorus (-9.0 mg/dL; 95% CI -17.5, -0.5), and urine urea nitrogen (-124.8 mg/dL; 95% CI -226.9, -22.6). Eating plant-meat compared with eating animal meat was associated with higher mean urine pH (+0.3 units; 95% CI 0.2, 0.5) and mean urine citrate/creatinine ratio (+111.65; 95% CI 52.69-170.60). After participants consumed a plant-meat diet compared with when they consumed an animal meat diet, mean serum creatinine concentration was lower (-0.07 mg/dL, 95% CI -0.10, -0.04), whereas mean serum bicarbonate concentration was not different. CONCLUSIONS: Eating plant-based meat products, compared with eating animal meat, was associated with lower urinary excretion of sulfate, ammonium, phosphorus, and urea nitrogen and higher urinary excretion of citrate. Our findings provide rationale for examining whether plant-based meat will benefit patients with kidney disease.

The Bone, Exercise, Alendronate, and Caloric Restriction (BEACON) trial design and methods.

BACKGROUND: Among older adults living with obesity, intentional weight loss (WL) improves prognosis of many comorbidities. However, concomitant decline in bone mineral density (BMD) limits overall benefit of WL by increasing osteoporotic fracture risk. Identification of intervention strategies to maximize body fat loss, while minimizing harm to the musculoskeletal system, is an important area of clinical research. The main objective of the Bone, Exercise, Alendronate, and Caloric Restriction (BEACON) trial (NCT05764733) is to compare the independent and combined effects of a 12-month intervention of resistance training (RT) plus bone-loading exercises and bisphosphonate use on dietary WL-associated bone loss among 308 older (≥60 years) adults living with an indication for WL and bisphosphonate use. METHODS: All participants will receive the same group-mediated dietary intervention targeting 8-10 % WL and be randomized to one of four groups: no RT and placebo capsules (NoRT+PL); progressive RT plus bone-loading exercises and placebo capsules (RT++PL); no RT and oral bisphosphonate (70 mg weekly oral alendronate; NoRT+BIS); or progressive RT plus bone-loading exercises and oral bisphosphonate (RT++BIS). Total hip areal (a)BMD measured via dual-energy x-ray absorptiometry (DXA) is the primary, powered study outcome. Secondary skeletal outcome measures include femoral neck and lumbar spine aBMD, high resolution peripheral quantitative computed tomography (HRpQCT) bone assessments of the radius and tibia, and biomarkers of bone turnover. DISCUSSION: BEACON will address an understudied, yet important, clinical research question by studying the independent and combined effects of two scalable intervention strategies aimed at optimizing skeletal integrity in older adults undergoing WL. CLINICAL TRIALS REGISTRATION: NCT05764733.

Technical considerations for placental tissue processing and the subsequent impact on genome-wide DNA methylation analysis.

To assess the impact of postnatal processing on placental DNA methylation, array data from flash-frozen placental tissue was compared to perfluorocarbon-immersed and formalin-fixed paraffin-embedded placental tissue. We observed that tissue exposed to perfluorocarbon showed no significant DNA methylation differences when compared to unprocessed tissue, while formalin processing altered the quality and reliability of the data produced on the DNA methylation array platform. Placental DNA methylation allows for the study of gene-environment interactions that influence the fetal environment and development. Our study highlights that placental post-processing techniques must be considered in the evaluation and interpretation of epigenetic studies.

Distinct mucosal endotypes as initiators and drivers of rheumatoid arthritis.

Rheumatoid arthritis (RA) is a potentially devastating autoimmune disease. The great majority of patients with RA are seropositive for anti-citrullinated protein antibodies (ACPAs), rheumatoid factors, or other autoantibodies. The onset of clinically apparent inflammatory arthritis meeting classification criteria (clinical RA) is preceded by ACPA seropositivity for an average of 3-5 years, a period that is designated as 'at-risk' of RA for ACPA-positive individuals who do not display signs of arthritis, or 'pre-RA' for individuals who are known to have progressed to developing clinical RA. Prior studies of individuals at-risk of RA have associated pulmonary mucosal inflammation with local production of ACPAs and rheumatoid factors, leading to development of the 'mucosal origins hypothesis'. Recent work now suggests the presence of multiple distinct mucosal site-specific mechanisms that drive RA evolution. Indicatively, subsets of individuals at-risk of RA and patients with RA harbour a faecal bacterial strain that has exhibited arthritogenic activity in animal models and that favours T helper 17 (TH17) cell responses in patients. Periodontal inflammation and oral microbiota have also been suggested to promote the development of arthritis through breaches in the mucosal barrier. Herein, we argue that mucosal sites and their associated microbial strains can contribute to RA evolution via distinct pathogenic mechanisms, which can be considered causal mucosal endotypes. Future therapies instituted for prevention in the at-risk period, or, perhaps, during clinical RA as therapeutics for active arthritis, will possibly have to address these individual mechanisms as part of precision medicine approaches.

Age differences in BOLD modulation to task difficulty as a function of amyloid burden.

Effective cognitive performance often requires the allocation of additional neural resources (i.e. blood-oxygen-level-dependent [BOLD] activation) as task demands increase, and this demand-related modulation is affected by amyloid-beta deposition and normal aging. The present study investigated these complex relationships between amyloid, modulation, and cognitive function (i.e. fluid ability). Participants from the Dallas Lifespan Brain Study (DLBS, n = 252, ages 50-89) completed a semantic judgment task during functional magnetic resonance imaging (fMRI) where the judgments differed in classification difficulty. Amyloid burden was assessed via positron emission tomography (PET) using 18F-florbetapir. A quadratic relationship between amyloid standardized value uptake ratios (SUVRs) and BOLD modulation was observed such that modulation was weaker in those with moderately elevated SUVRs (e.g. just reaching amyloid-positivity), whereas those with very high SUVRs (e.g. SUVR > 1.5) showed strong modulation. Greater modulation was related to better fluid ability, and this relationship was strongest in younger participants and those with lower amyloid burden. These results support the theory that effective demand-related modulation contributes to healthy cognitive aging, especially in the transition from middle age to older adulthood, whereas high modulation may be dysfunctional in those with substantial amyloid deposition.

Closing the Trauma Performance Improvement Loop With In-situ Simulation.

INTRODUCTION: Continuous performance improvement (PI) programs are essential for excellent trauma care. We incorporated PI identified from trauma cases into an in-situ simulation-based medical education curriculum. This is a proof-of-concept study exploring the efficacy of high-fidelity pediatric trauma simulations in improving self-reported provider comfort and knowledge for identified trauma PI issues. METHODS: This study was performed at an American College of Surgeons-verified Level I Pediatric Trauma Center. Several clinical issues were identified during the trauma PI process, including management of elevated intracranial pressure in traumatic brain injury and the use of massive transfusion protocol. These issues were incorporated into a simulation-based medical education curriculum and high-fidelity in-situ trauma mock codes were held. In-depth debriefing sessions were led by a senior faculty member after the simulations. The study participants completed pre- and postsimulation surveys. Univariate statistics are presented. RESULTS: Twenty three providers completed surveys for the pediatric trauma simulations. Self-reported provider confidence Likert scale improved from pre- to postsimulation (P = 0.02) and trauma experience and knowledge scores improved from 82% presimulation to 93% postsimulation (P = 0.02). CONCLUSIONS: High-fidelity pediatric trauma simulations enhance provider comfort, knowledge, and experience in trauma scenarios. By integrating high-fidelity trauma simulations to address clinical issues identified in the trauma PI process, provider education can be reinforced and practiced in a controlled environment to improve trauma care. Future studies evaluating the implementation of clinical pathways and patient outcomes are needed to demonstrate the effectiveness of simulations in PI pathways.

Regulation of Bacteroides acidifaciens by the aryl hydrocarbon receptor in IL-22-producing immune cells has sex-dependent consequential impact on colitis.

Introduction: Colitis is an inflammatory bowel disease (IBD) characterized by immune cell dysregulation and alterations in the gut microbiome. In our previous report, we showed a natural product in cruciferous vegetables and ligand of the aryl hydrocarbon receptor (AhR), indole-3-carbinol (I3C), was able to reduce colitis-induced disease severity and microbial dysbiosis in an interleukin-22 (IL-22) dependent manner. Methods: In the current study, we performed single-cell RNA sequencing (scRNAseq) from colonocytes during colitis induction and supplementation with I3C and show how this treatment alters expression of genes involved in IL-22 signaling. To further define the role of IL-22 signaling in I3C-mediated protection during colitis and disease-associated microbial dysbiosis, we generated mice with AhR deficiency in RAR-related orphan receptor c (Rorc)-expressing cells (AhR ΔRorc ) which depletes this receptor in immune cells involved in production of IL-22. Colitis was induced in wildtype (WT), AhR ΔRorc , and littermate (LM) mice with or without I3C treatment. Results: Results showed AhR ΔRorc mice lost the efficacy effects of I3C treatment which correlated with a loss of ability to increase IL-22 by innate lymphoid type 3 (ILC3s), not T helper 22 (Th22) cells. 16S rRNA microbiome profiling studies showed AhR ΔRorc mice were unable to regulate disease-associated increases in Bacteroides, which differed between males and females. Lastly, inoculation with a specific disease-associated Bacteroides species, Bacteroides acidifaciens (B. acidifaciens), was shown to exacerbate colitis in females, but not males. Discussion: Collectively, this report highlights the cell and sex-specific role of AhR in regulating microbes that can impact colitis disease.

Impact of Spousal Mental Illness on Healthcare Utilization Among Patients With Gastrointestinal Cancer.

BACKGROUND: Informal caregiving involves increased responsibilities, with financial and emotional challenges, thereby affecting the well-being of the caregiver. We aimed to investigate the effect of spousal mental illness on hospital visits and medical spending among patients with gastrointestinal (GI) cancer. METHODS: Patients who underwent GI cancer surgery between 2013 and 2020 were identified from the IBM Marketscan database. Multivariable regression analysis was used to examine the association between spousal mental illness and healthcare utilization. RESULTS: A total of 6,035 patients underwent GI surgery for a malignant indication. Median age was 54 years (IQR: 49-59), most patients were male (n = 3592, 59.5%), and had a CCI score of ≤ 2 (n = 5512, 91.3%). Of note, in the 1 year follow-up period, 19.4% (anxiety: n = 509, 8.4%; depression: n = 301, 5.0%; both anxiety and depression: n = 273, 4.5%; severe mental illness: n = 86, 1.4%) of spouses developed a mental illness. On multivariable analysis, after controlling for competing factors, spousal mental illness remained independently associated with increased odds of emergency department visits (OR 1.20, 95% CI 1.05-1.38) and becoming a super healthcare utilizer (OR 1.37, 95% CI 1.04-1.79), as well as 12.1% (95% CI 10.6-15.3) higher medical spending. CONCLUSION: Among patients with GI cancer spousal mental illness is associated with higher rates of outpatient visits, emergency department visits, and expenditures during the 1-year postoperative period. These findings underscore the importance of caregiving resources and counseling in alleviating caregiver burden, thereby reducing the overall burden on the healthcare system.

GRK2 kinases in the primary cilium initiate SMOOTHENED-PKA signaling in the Hedgehog cascade.

During Hedgehog (Hh) signal transduction in development and disease, the atypical G protein-coupled receptor (GPCR) SMOOTHENED (SMO) communicates with GLI transcription factors by binding the protein kinase A catalytic subunit (PKA-C) and physically blocking its enzymatic activity. Here, we show that GPCR kinase 2 (GRK2) orchestrates this process during endogenous mouse and zebrafish Hh pathway activation in the primary cilium. Upon SMO activation, GRK2 rapidly relocalizes from the ciliary base to the shaft, triggering SMO phosphorylation and PKA-C interaction. Reconstitution studies reveal that GRK2 phosphorylation enables active SMO to bind PKA-C directly. Lastly, the SMO-GRK2-PKA pathway underlies Hh signal transduction in a range of cellular and in vivo models. Thus, GRK2 phosphorylation of ciliary SMO and the ensuing PKA-C binding and inactivation are critical initiating events for the intracellular steps in Hh signaling. More broadly, our study suggests an expanded role for GRKs in enabling direct GPCR interactions with diverse intracellular effectors.

Increased Netrin downstream of overactive Hedgehog signaling disrupts optic fissure formation.

BACKGROUND: Uveal coloboma, a developmental eye defect, is caused by failed development of the optic fissure, a ventral structure in the optic stalk and cup where axons exit the eye and vasculature enters. The Hedgehog (Hh) signaling pathway regulates optic fissure development: loss-of-function mutations in the Hh receptor ptch2 produce overactive Hh signaling and can result in coloboma. We previously proposed a model where overactive Hh signaling disrupts optic fissure formation by upregulating transcriptional targets acting both cell- and non-cell-autonomously. Here, we examine the Netrin family of secreted ligands as candidate Hh target genes. RESULTS: We find multiple Netrin ligands upregulated in the zebrafish ptch2 mutant during optic fissure development. Using a gain-of-function approach to overexpress Netrin in a spatiotemporally specific manner, we find that netrin1a or netrin1b overexpression is sufficient to cause coloboma and disrupt wild-type optic fissure formation. We used loss-of-function alleles, CRISPR/Cas9 mutagenesis, and morpholino knockdown to test if loss of Netrin can rescue coloboma in the ptch2 mutant: loss of netrin genes does not rescue the ptch2 mutant phenotype. CONCLUSION: These results suggest that Netrin is sufficient but not required to disrupt optic fissure formation downstream of overactive Hh signaling in the ptch2 mutant.

The Importance of Racially and Ethnically Inclusive Gait Speed Reference Values in Individuals 90 Years and Older: LifeAfter90.

BACKGROUND AND PURPOSE: Clinicians use reference values to contextualize physical performance scores, but data are sparse in individuals 90 years and older and racial/ethnic diversity is limited in existing studies. Gait speed provides valuable information about an individual's health status. Slow gait speed is associated with falls, cognitive decline, and mortality. Here, we report gait speed reference values in a racially/ethnically diverse oldest-old cohort. METHODS: LifeAfter90 is a multiethnic cohort study of individuals 90 years and older. Participants are long-term members of an integrated healthcare delivery system without a dementia diagnosis at enrollment. We assessed gait speed using the 4-m walk test and calculated means, standard deviations, and percentiles by age, sex, assistive device use, and device type. We used linear regression to compare means by sex, age, device use and type, living situation and arrangement, and race/ethnicity. RESULTS AND DISCUSSION: The mean age of the 502 participants was 92.9 (range 90.1-102.8) years. Of these, 62.6% were women, 34.7% were college educated, 90.8% lived in a private residence, 20.9% self-reported as Asian, 22.5% as Black, 11.8% as Hispanic, 35.7% as White, and 9.2% as multiple, "other," or declined to state. The overall mean gait speed was 0.54 m/s (women = 0.51 m/s, men = 0.58 m/s). Mean gait speeds were 0.58 m/s, 0.53 m/s, and 0.48 m/s in the 90 to 91, 92 to 93, and 94+ age categories, respectively. In those without a device, mean gait speed was 0.63 m/s compared to 0.40 m/s in those with a device (cane = 0.44 m/s, walker = 0.37 m/s). Mean gait speed was significantly slower in women compared to men, age category 94+ compared to 90 to 91, participants with a device compared to those without, participants with a walker compared to a cane, and Black participants compared to Asian and White participants. However, differences by race/ethnicity were attenuated when chronic health conditions were considered. CONCLUSIONS: Reference values developed from this multiethnic 90+ cohort will help clinicians interpret gait speed measures and tailor recommendations toward a 90+ population that is growing in number and in racial/ethnic diversity.