234 research outputs found

    Inflammasome activation in neutrophils of patients with severe COVID-19

    Get PDF
    © The Author(s), 2022. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Aymonnier, K., Ng, J., Fredenburgh, L. E., Zambrano-Vera, K., Muenzer, P., Gutch, S., Fukui, S., Desjardins, M., Subramaniam, M., Baron, R. M., Raby, B. A., Perrella, M. A., Lederer, J. A., & Wagner, D. D. Inflammasome activation in neutrophils of patients with severe COVID-19. Blood Advances, 6(7), (2022): 2001–2013, https://doi.org/10.1182/bloodadvances.2021005949.Infection by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) engages the inflammasome in monocytes and macrophages and leads to the cytokine storm in COVID-19. Neutrophils, the most abundant leukocytes, release neutrophil extracellular traps (NETs), which have been implicated in the pathogenesis of COVID-19. Our recent study shows that activation of the NLRP3 inflammasome is important for NET release in sterile inflammation. However, the role of neutrophil inflammasome formation in human disease is unknown. We hypothesized that SARS-CoV-2 infection may induce inflammasome activation in neutrophils. We also aimed to assess the localization of inflammasome formation (ie, apoptosis-associated speck-like protein containing a CARD [ASC] speck assembly) and timing relative to NETosis in stimulated neutrophils by real-time video microscopy. Neutrophils isolated from severe COVID-19 patients demonstrated that ∼2% of neutrophils in both the peripheral blood and tracheal aspirates presented ASC speck. ASC speck was observed in neutrophils with an intact poly-lobulated nucleus, suggesting early formation during neutrophil activation. Additionally, 40% of nuclei were positive for citrullinated histone H3, and there was a significant correlation between speck formation and nuclear histone citrullination. Time-lapse microscopy in lipopolysaccharide -stimulated neutrophils from fluorescent ASC reporter mice showed that ASC speck formed transiently and at the microtubule organizing center long before NET release. Our study shows that ASC speck is present in neutrophils from COVID-19 patients with respiratory failure and that it forms early in NETosis. Our findings suggest that inhibition of neutrophil inflammasomes may be beneficial in COVID-19.P.M. received an Individual Marie Skłodowska-Curie Actions fellowship by the European Commission (796365 - COAGULANT). This work was supported by the National Institutes of Health (NIH)/Research Program Award grant R35 HL135765 (D.W.), by the NIH/National Heart, Lung, and Blood Institute grant T32 HL007633-35 (J.N.), and by the NIH/National Institute of Allergy and Infectious Diseases grant U01AI138318 (J.L and M.P); by the Massachusetts Consortium on Pathogen Readiness (MassCPR) Evergrande COVID‐19 Response Fund Award to B.R.; and by a generous gift to D.W. from the Steven Berzin family

    High accuracy 234U(n,f) cross section in the resonance energy region

    Get PDF
    New results are presented of the 234U neutron-induced fission cross section, obtained with high accuracy in the resonance region by means of two methods using the 235U(n,f) as reference. The recent evaluation of the 235U(n,f) obtained with SAMMY by L. C. Leal et al. (these Proceedings), based on previous n-TOF data [1], has been used to calculate the 234U(n,f) cross section through the 234U/235U ratio, being here compared with the results obtained by using the n-TOF neutron flux

    Development and Reporting of Prediction Models: Guidance for Authors From Editors of Respiratory, Sleep, and Critical Care Journals

    Get PDF
    Prediction models aim to use available data to predict a health state or outcome that has not yet been observed. Prediction is primarily relevant to clinical practice, but is also used in research, and administration. While prediction modeling involves estimating the relationship between patient factors and outcomes, it is distinct from casual inference. Prediction modeling thus requires unique considerations for development, validation, and updating. This document represents an effort from editors at 31 respiratory, sleep, and critical care medicine journals to consolidate contemporary best practices and recommendations related to prediction study design, conduct, and reporting. Herein, we address issues commonly encountered in submissions to our various journals. Key topics include considerations for selecting predictor variables, operationalizing variables, dealing with missing data, the importance of appropriate validation, model performance measures and their interpretation, and good reporting practices. Supplemental discussion covers emerging topics such as model fairness, competing risks, pitfalls of “modifiable risk factors”, measurement error, and risk for bias. This guidance is not meant to be overly prescriptive; we acknowledge that every study is different, and no set of rules will fit all cases. Additional best practices can be found in the Transparent Reporting of a multivariable prediction model for Individual Prognosis Or Diagnosis (TRIPOD) guidelines, to which we refer readers for further details

    Development of the Critical Thinking Toolkit (CriTT): a measure of student attitudes and beliefs about critical thinking

    Get PDF
    Critical thinking is an important focus in higher education and is essential for good academic achievement. We report the development of a tool to measure critical thinking for three purposes: (i) to evaluate student perceptions and attitudes about critical thinking, (ii) to identify students in need of support to develop their critical thinking, and (iii) to predict academic performance. Seventy-seven items were generated from focus groups, interviews and the critical thinking literature. Data were collected from 133 psychology students. Factor Analysis revealed three latent factors based on a reduced set of 27 items. These factors were characterised as: Confidence in Critical Thinking; Valuing Critical Thinking; and Misconceptions. Reliability analysis demonstrated that the sub-scales were reliable. Convergent validity with measures of grade point average and argumentation skill was shown, with significant correlations between subscales and validation measures. Most notably, in multiple regression analysis, the three sub-scales from the new questionnaire substantially increased the variance in grade point average accounted for by measures of reflective thinking and argumentation. To sum, the resultant scale offers a measure that is simple to administer, can be used as a diagnostic tool to identify students who need support in developing their critical thinking skills, and can also predict academic performance

    A Novel CCR5 Mutation Common in Sooty Mangabeys Reveals SIVsmm Infection of CCR5-Null Natural Hosts and Efficient Alternative Coreceptor Use In Vivo

    Get PDF
    In contrast to HIV infection in humans and SIV in macaques, SIV infection of natural hosts including sooty mangabeys (SM) is non-pathogenic despite robust virus replication. We identified a novel SM CCR5 allele containing a two base pair deletion (Δ2) encoding a truncated molecule that is not expressed on the cell surface and does not support SIV entry in vitro. The allele was present at a 26% frequency in a large SM colony, along with 3% for a CCR5Δ24 deletion allele that also abrogates surface expression. Overall, 8% of animals were homozygous for defective CCR5 alleles and 41% were heterozygous. The mutant allele was also present in wild SM in West Africa. CD8+ and CD4+ T cells displayed a gradient of CCR5 expression across genotype groups, which was highly significant for CD8+ cells. Remarkably, the prevalence of natural SIVsmm infection was not significantly different in animals lacking functional CCR5 compared to heterozygous and homozygous wild-type animals. Furthermore, animals lacking functional CCR5 had robust plasma viral loads, which were only modestly lower than wild-type animals. SIVsmm primary isolates infected both homozygous mutant and wild-type PBMC in a CCR5-independent manner in vitro, and Envs from both CCR5-null and wild-type infected animals used CXCR6, GPR15 and GPR1 in addition to CCR5 in transfected cells. These data clearly indicate that SIVsmm relies on CCR5-independent entry pathways in SM that are homozygous for defective CCR5 alleles and, while the extent of alternative coreceptor use in SM with CCR5 wild type alleles is uncertain, strongly suggest that SIVsmm tropism and host cell targeting in vivo is defined by the distribution and use of alternative entry pathways in addition to CCR5. SIVsmm entry through alternative pathways in vivo raises the possibility of novel CCR5-negative target cells that may be more expendable than CCR5+ cells and enable the virus to replicate efficiently without causing disease in the face of extremely restricted CCR5 expression seen in SM and several other natural host species
    corecore