Clonal Tracking of Rhesus Macaque Hematopoiesis Highlights a Distinct Lineage Origin for Natural Killer Cells

SummaryAnalysis of hematopoietic stem cell function in nonhuman primates provides insights that are relevant for human biology and therapeutic strategies. In this study, we applied quantitative genetic barcoding to track the clonal output of transplanted autologous rhesus macaque hematopoietic stem and progenitor cells over a time period of up to 9.5 months. We found that unilineage short-term progenitors reconstituted myeloid and lymphoid lineages at 1 month but were supplanted over time by multilineage clones, initially myeloid restricted, then myeloid-B clones, and then stable myeloid-B-T multilineage, long-term repopulating clones. Surprisingly, reconstitution of the natural killer (NK) cell lineage, and particularly the major CD16+/CD56− peripheral blood NK compartment, showed limited clonal overlap with T, B, or myeloid lineages, and therefore appears to be ontologically distinct. Thus, in addition to providing insights into clonal behavior over time, our analysis suggests an unexpected paradigm for the relationship between NK cells and other hematopoietic lineages in primates

The Association of Nutrition Status Expressed as Body Mass Index z Score With Outcomes in Children With Severe Sepsis: A Secondary Analysis From the Sepsis Prevalence, Outcomes, and Therapies (SPROUT) Study

Contains fulltext : 200437.pdf (publisher's version ) (Closed access)OBJECTIVES: The impact of nutrition status on outcomes in pediatric severe sepsis is unclear. We studied the association of nutrition status (expressed as body mass index z score) with outcomes in pediatric severe sepsis. DESIGN: Secondary analysis of the Sepsis Prevalence, Outcomes, and Therapies study. Patient characteristics, ICU interventions, and outcomes were compared across nutrition status categories (expressed as age- and sex-adjusted body mass index z scores using World Health Organization standards). Multivariable regression models were developed to determine adjusted differences in all-cause ICU mortality and ICU length of stay by nutrition status. SETTING: One-hundred twenty-eight PICUs across 26 countries. PATIENTS: Children less than 18 years with severe sepsis enrolled in the Sepsis Prevalence, Outcomes, and Therapies study (n = 567). INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Nutrition status data were available for 417 patients. Severe undernutrition was seen in Europe (25%), Asia (20%), South Africa (17%), and South America (10%), with severe overnutrition seen in Australia/New Zealand (17%) and North America (14%). Severe undernutrition was independently associated with all-cause ICU mortality (adjusted odds ratio, 3.0; 95% CI, 1.2-7.7; p = 0.02), whereas severe overnutrition in survivors was independently associated with longer ICU length of stay (1.6 d; p = 0.01). CONCLUSIONS: There is considerable variation in nutrition status for children with severe sepsis treated across this selected network of PICUs from different geographic regions. Severe undernutrition was independently associated with higher all-cause ICU mortality in children with severe sepsis. Severe overnutrition was independently associated with greater ICU length of stay in childhood survivors of severe sepsis

Phylogenomics and the rise of the angiosperms

Angiosperms are the cornerstone of most terrestrial ecosystems and human livelihoods1,2. A robust understanding of angiosperm evolution is required to explain their rise to ecological dominance. So far, the angiosperm tree of life has been determined primarily by means of analyses of the plastid genome3,4. Many studies have drawn on this foundational work, such as classification and first insights into angiosperm diversification since their Mesozoic origins5,6,7. However, the limited and biased sampling of both taxa and genomes undermines confidence in the tree and its implications. Here, we build the tree of life for almost 8,000 (about 60%) angiosperm genera using a standardized set of 353 nuclear genes8. This 15-fold increase in genus-level sampling relative to comparable nuclear studies9 provides a critical test of earlier results and brings notable change to key groups, especially in rosids, while substantiating many previously predicted relationships. Scaling this tree to time using 200 fossils, we discovered that early angiosperm evolution was characterized by high gene tree conflict and explosive diversification, giving rise to more than 80% of extant angiosperm orders. Steady diversification ensued through the remaining Mesozoic Era until rates resurged in the Cenozoic Era, concurrent with decreasing global temperatures and tightly linked with gene tree conflict. Taken together, our extensive sampling combined with advanced phylogenomic methods shows the deep history and full complexity in the evolution of a megadiverse clade