Project description:Electronic cigarette use has increased dramatically over the past three years, despite numerous reports of acute lung injury and even death. In this report we provide evidence from a nonhuman primate model for Electronic Vapor-Induced Lung Injury (EVALI), demonstrating significant lung pathology from electronic vaping (EV). Here we characterized the particle size and pathogenic effects induced by EV exposure of nonhuman primates using the commercial nicotine JUUL® pod modular devices. Vaping aerosols appear to preferentially and exclusively target the bronchioles while bypassing larger bronchi. We demonstrate a significantly smaller particle size, generated by the EV device relative to combustion product aerosols produced by conventional cigarettes. Histopathologically, vaping aerosols appear to preferentially and exclusively target the bronchioles while bypassing larger bronchi which is consistent with a significanlty smaller particle size compared to cigarette smoke. Our immunohistochemical and RNAseq studies provide further evidence for severe small airway inflammation and dysregulation of gene expression within immune cells derived from bronchial lavage, respectively. Our findings raise major concerns regarding the safety of e-cigarettes, and provide a mechanism for the preferential induction of lung injury by EV. Our results, in a species whose lung architecture is the closest possible approximation of that of a human adolescent, suggest the danger of the EV device itself and resultant small particulate aerosols produced, preferentially entering and damaging a highly susceptible part of the respiratory system.
2022-07-01 | GSE199072 | GEO
Project description:Bacterial community in soils from residential areas in China
Project description:Smoking cigarettes is harmful to the cardiovascular system. Considerable attention has been paid to the reduced harm potential of alternative nicotine-containing inhalable products such as e-cigarettes. We investigated the effects of E-vapor aerosols or cigarette smoke (CS) on atherosclerosis progression, cardiovascular function, and molecular changes in the heart and aorta of female ApoE−/− mice. The mice were exposed to aerosols from three different E-vapor formulations: (1) carrier (propylene glycol and vegetable glycerol), (2) base (carrier and nicotine) or (3) test (base and flavor) or to CS from 3R4F reference cigarettes for up to 6 months. Concentrations of CS and base or test aerosols were matched at 35 µg nicotine/L. Exposure to CS, compared with sham-exposed fresh air controls, accelerated atherosclerotic plaque formation, while no such effect was seen for any of the three E-vapor aerosols. Molecular changes indicated disease mechanisms related to oxidative stress and inflammation in general, plus changes in calcium regulation, and altered cytoskeletal organization and microtubule dynamics in the left ventricle. While ejection fraction, fractional shortening, cardiac output, and isovolumic contraction time remained unchanged following E-vapor aerosols exposure, the nicotine-containing base and test aerosols caused an increase in isovolumic relaxation time similar to CS. A nicotine-related increase in pulse wave velocity and arterial stiffness was also observed, but it was significantly lower for base and test aerosols than for CS. These results demonstrate that in comparison with CS, E-vapor aerosols induce substantially lower biological responses associated with smoking-related cardiovascular diseases.
Project description:Airborne transmission of SARS-CoV-2 aerosol remains contentious. Importantly, whether cough or breath-generated bioaerosols can harbor viable and replicating virus remains largely unclarified. We perform size-fractionated aerosol sampling (Andersen cascade impactor) and evaluate viral culturability in human cell lines (infectiousness), viral genetics, and host immunity in ambulatory participants with COVID-19. Sixty-one percent (27/44) and 50% (22/44) of participants emitted variant-specific culture-positive aerosols <10μm and <5μm, respectively, for up to 9 days after symptom onset. Aerosol culturability is significantly associated with lower neutralizing antibody titers, and suppression of transcriptomic pathways related to innate immunity and the humoral response. A nasopharyngeal Ct <17 rules-in ~40% of aerosol culture-positives and identifies those who are probably highly infectious. A parsimonious three transcript blood-based biosignature is highly predictive of infectious aerosol generation (PPV> 95%). There is considerable heterogeneity in potential infectiousness i.e., only 29% of participants were probably highly infectious (produced culture-positive aerosols <5μm at ~6 days after symptom onset). These data, which comprehensively confirm variant-specific culturable SARS-CoV-2 in aerosol, inform the targeting of transmission-related interventions and public health containment strategies emphasizing improved ventilation.
2024-03-13 | GSE252508 | GEO
Project description:Microalgal-bacterial granules - effect of size
Project description:Characterization of the zebrafish embryonic host response to systemic bacterial infection with Salmonella typhimurium wild type strain (SL1027) and its isogenic LPS O-antigen mutant Ra (SF1592) by means of a time-resolved global expression analysis.
Project description:Clonal bacterial populations rely on transcriptional variation across individual cells to commit to specialized states that increase the population’s fitness. Such heterogeneous gene expression is implicated in fundamental microbial processes including sporulation, cell communication, detoxification, substrate utilization, competence, biofilm formation, and motility1. To identify specialized cell states and determine the processes by which they develop, isogenic bacterial populations need to be studied at the single cell level2,3. Here, we developed ProBac-seq a method that uses libraries of DNA probes and leverages an existing commercial microfluidic platform to conduct bacterial single cell RNA sequencing. We sequenced the transcriptome of thousands of individual bacterial cells per experiment, detecting several hundred transcripts per cell on average. When applying this method to the model organisms Bacillus subtilis and Escherichia coli, we correctly identify known cell states and uncover previously unreported transcriptional heterogeneity. In the context of bacterial pathogenesis, single cell RNA-seq of the pathogen Clostridium perfringens reveals that toxin is differentially expressed by a subpopulation of cells with a distinct transcriptional profile. We further show that the size of the toxin producing subpopulation and the secreted toxin levels can be downregulated by providing acetate, a short chain fatty acid highly prevalent in the gut. Overall, we demonstrate that our high throughput, highly resolved single cell transcriptomic platform can be broadly used to uncover heterogeneity in isogenic microbial populations and identify perturbations that can impact pathogenicity.