The number of virus particles on Earth is frequently reported in the scientific literature and in general-interest publications as being on the order of 1031, with some confusion about whether this is a high or low estimate. This number is often given without a source, though it should be attributed a papers by Roger Hendrix published in 1999. As with any oft-repeated statistic, it is informative to know how it has been derived and whether it may have to be revised in the light of new evidence. I review the history of the 1031 estimate and use more recent assessments of the number of bacterial and viral particles in various habitats to conclude that the best estimate of the number of virus particles on Earth ("The Hendrix Product") remains close to 1031, and is unlikely to be either much less, or much more than that. This is a work of the U.S. Government and is not subject to copyright protection in the United States. Foreign copyrights may apply.OBJECTIVE Transcatheter aortic valve implantation (TAVI) is the most common aortic valve replacement in Germany. Since 2015, to ensure high-quality procedures, hospitals in Germany and other countries that meet the minimum requirement of 50 interventions per centre are being certified to perform TAVI. This study analyses the impact of these requirements on case number and in-hospital outcomes. METHODS All isolated TAVI procedures and in-hospital outcomes between 2008 and 2016 were identified by International Classification of Diseases (ICD) and the German Operation and Procedure Classification codes. RESULTS 73 467 isolated transfemoral and transapical TAVI procedures were performed in Germany between 2008 and 2016. During this period, the number of TAVI procedures per year rose steeply, whereas the overall rates of hospital mortality and complications declined. In 2008, the majority of procedures were performed in hospitals with fewer than 50 cases per year (54.63%). Until 2014, the share of patients treated in low-volume centres constantly decreased to 5.35%. After the revision of recommendations, it further declined to 1.99%. In the 2 years after the introduction of the minimum requirements on case numbers, patients were at decreased risk for in-hospital mortality when treated in a high-volume centre (risk-adjusted OR 0.62, p=0.012). The risk for other in-hospital outcomes (stroke, permanent pacemaker implantation and bleeding events) did not differ after risk adjustment (p=0.346, p=0.142 and p=0.633).  https://www.selleckchem.com/products/edralbrutinib.html  CONCLUSION A minimum volume of 50 procedures per centre and year appears suitable to allow for sufficient routine and thus better in-hospital outcomes, while ensuring nationwide coverage of TAVI procedures. © Author(s) (or their employer(s)) 2020. No commercial re-use. See rights and permissions. Published by BMJ.Cardiac neural crest (CNC) cells are pluripotent cells derived from the dorsal neural tube that migrate and contribute to the remodeling of pharyngeal arch arteries and septation of the cardiac outflow tract (OFT). Numerous molecular cascades regulate the induction, specification, delamination, and migration of the CNC. Extensive analyses of the CNC ranging from chick ablation models to molecular biology studies have explored the mechanisms of heart development and disease, particularly involving the OFT and aortic arch (AA) system. Recent studies focus more on reciprocal signaling between the CNC and cells originated from the second heart field (SHF), which are essential for the development of the OFT myocardium, providing new insights into the molecular mechanisms underlying congenital heart diseases (CHDs) and some human syndromes. Copyright © 2020 Cold Spring Harbor Laboratory Press; all rights reserved.The mammalian intestine is a complex environment that is constantly exposed to Ags derived from food, microbiota, and metabolites. Intestinal dendritic cells (DC) have the responsibility of establishing oral tolerance against these Ags while initiating immune responses against mucosal pathogens. We now know that DC are a heterogeneous population of innate immune cells composed of classical and monocyte-derived DC, Langerhans cells, and plasmacytoid DC. In the intestine, DC are found in organized lymphoid tissues, such as the mesenteric lymph nodes and Peyer's patches, as well as in the lamina propria. In this Brief Review, we review recent work that describes a division of labor between and collaboration among gut DC subsets in the context of intestinal homeostasis and inflammation. Understanding relationships between DC subtypes and their biological functions will rationalize oral vaccine design and will provide insights into treatments that quiet pathological intestinal inflammation. Copyright © 2020 by The American Association of Immunologists, Inc.Deubiquitinases deconjugate ubiquitin modifications from target proteins and are involved in many cellular processes in eukaryotes.  The functions of  deubiquitinases are regulated by post-translational modifications (PTMs), mainly phosphorylation and ubiquitination. PTMs can result in subtle changes in structural and dynamic properties, which are difficult to identify but functionally important. In this work, we used NMR spectroscopy to characterize the conformational properties of the human deubiquitinase A (DUBA), a negative regulator of type I interferon. DUBA activity is regulated by phosphorylation at a single serine residue, Ser-177. We found that the catalytic rate constant of DUBA is enhanced by phosphorylation. By comparing NMR and enzyme kinetics data among different forms of DUBA with low and high activities, we concluded that a two-state equilibrium that was present only in phosphorylated DUBA is important for DUBA activity.Our results highlight the importance of defining conformational dynamics in understanding the mechanism of DUBA activation. Published under license by The American Society for Biochemistry and Molecular Biology, Inc.In up to 15% of acute myeloid leukemias (AMLs), a recurring chromosomal translocation, termed t(8;21), generates the AML1-eight-twenty-one (ETO) leukemia fusion protein, which contains the DNA-binding domain of Runt-related transcription factor 1 (RUNX1) and almost all of ETO. RUNX1 and the AML1-ETO fusion protein are co-expressed in t(8;21) AML cells and antagonize each other's gene-regulatory functions. AML1-ETO represses transcription of RUNX1 target genes by competitively displacing RUNX1 and recruiting corepressors such as histone deacetylase 3 (HDAC3). Recent studies have shown that AML1-ETO and RUNX1 co-occupy the binding sites of AML1-ETO-activated genes. How this joined binding allows RUNX1 to antagonize AML1-ETO-mediated transcriptional activation is unclear. Here, we show that RUNX1 functions as a bona fide repressor of transcription activated by AML1-ETO. Mechanistically, we show that RUNX1 is a component of the HDAC3 corepressor complex and that HDAC3 preferentially binds to RUNX1 rather than to AML1-ETO in t(8;21) AML cells.