Niche-derived Semaphorin 4A safeguards functional identity of myeloid-biased hematopoietic stem cells.

Somatic stem cell pools comprise diverse, highly specialized subsets whose individual contribution is critical for the overall regenerative function. In the bone marrow, myeloid-biased hematopoietic stem cells (myHSCs) are indispensable for replenishment of myeloid cells and platelets during inflammatory response but, at the same time, become irreversibly damaged during inflammation and aging. Here we identify an extrinsic factor, semaphorin 4A (Sema4A), which non-cell-autonomously confers myHSC resilience to inflammatory stress.

Diagnostic Decision-Making Variability Between Novice and Expert Optometrists for Glaucoma: Comparative Analysis to Inform AI System Design.

Background: While expert optometrists tend to rely on a deep understanding of the disease and intuitive pattern recognition, those with less experience may depend more on extensive data, comparisons, and external guidance. Understanding these variations is important for developing artificial intelligence (AI) systems that can effectively support optometrists with varying degrees of experience and minimize decision inconsistencies.

Objective: The main objective of this study is to identify and analyze the variations in diagnostic decision-making approaches between novice and expert optometrists.

Heterogeneity and plasticity of the naïve CD4+ T cell compartment.

While naïve CD4+ T cells have historically been considered a homogenous population, recent studies have provided evidence that functional heterogeneity exists within this population. Using single cell RNA sequencing (scRNAseq), we identify five transcriptionally distinct naïve CD4+ T cell subsets that emerge within the single positive stage in the thymus: a quiescence cluster (TQ), a memory-like cluster (TMEM), a TCR reactive cluster (TTCR), an IFN responsive cluster (TIFN), and an undifferentiated cluster (TUND). Elevated expression of transcription factors KLF2, Mx1, and Nur77 within the TQ, TIFN, and TMEM clusters, respectively, allowed enrichment of these subsets for further analyses.

Practice patterns for acquiring neuroimaging after pediatric in-hospital cardiac arrest.

Aims: To determine which patient and cardiac arrest factors were associated with obtaining neuroimaging after in-hospital cardiac arrest, and among those patients who had neuroimaging, factors associated with which neuroimaging modality was obtained.

Methods: Retrospective cohort study of patients who survived in-hospital cardiac arrest (IHCA) and were enrolled in the ICU-RESUS trial (NCT02837497).

Results: We tabulated ultrasound (US), CT, and MRI frequency within 7 days following IHCA and identified patient and cardiac arrest factors associated with neuroimaging modalities utilized.