Scalable nonparametric clustering with unified marker gene selection for single-cell RNA-seq data.

Clustering is commonly used in single-cell RNA-sequencing (scRNA-seq) pipelines to characterize cellular heterogeneity. However, current methods face two main limitations. First, they require user-specified heuristics which add time and complexity to bioinformatic workflows; second, they rely on post-selective differential expression analyses to identify marker genes driving cluster differences, which has been shown to be subject to inflated false discovery rates.

Operative Versus Nonoperative Management of Displaced Midshaft Clavicle Fractures in Pediatric and Adolescent Patients: A Systematic Review and Meta-Analysis.

Objectives: The purpose of this study was to systematically review and quantitatively analyze outcomes in operative versus nonoperative management of displaced midshaft clavicle fractures in pediatric and adolescent patients.

Data Sources: Using the Preferred Reporting items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, systematic searches of PubMed and EMBASE were conducted to identify English-language studies reporting outcomes in displaced pediatric midshaft clavicle fractures from 1997 to 2018.

Study Selection: Studies that reported on outcomes of operative and/or nonoperative treatment of displaced midshaft clavicle fractures in patients younger than 19 years were included.

Heuristic bias in stem cell biology.

When studying purified hematopoietic stem cells, the urge for mechanisms and reductionist approaches appears to be overwhelming. The prime focus of the field has recently been on the study of highly purified hematopoietic stem cells using various lineage and stem cell-specific markers, all of which adequately and conveniently fit the established hierarchical stem cell model. This methodology is tainted with bias and has led to incomplete conclusions.

Stem cells and extracellular vesicles: biological regulators of physiology and disease.

Many different subpopulations of subcellular extracellular vesicles (EVs) have been described. EVs are released from all cell types and have been shown to regulate normal physiological homeostasis, as well as pathological states by influencing cell proliferation, differentiation, organ homing, injury and recovery, as well as disease progression. In this review, we focus on the bidirectional actions of vesicles from normal and diseased cells on normal or leukemic target cells; and on the leukemic microenvironment as a whole.