RESUMEN
The use of IQOS brand heated tobacco products (HTPs) is increasing worldwide; however, little is known about the long-term effects of HTPs aerosol exposure on the lungs. Herein, we exposed C57BL/6 J mice for 24 weeks to clean air, IQOS aerosol, or cigarette smoke, and determined pulmonary function, lung tissue pathology, inflammation, and oxidative stress. Compared with the control group mice, IQOS group mice showed substantially decreased weight and lung function. Levels of IL-6 and TNF-a, as well as oxidative stress markers, were comparable to those found in the cigarette group. In addition, hematoxylin and eosin staining showed that the alveolar space was enlarged and that emphysema had formed in the IQOS group. Masson staining showed that collagen deposition areas were substantially increased in the airway walls in the IQOS group than in the control group. Immunohistochemical staining showed epithelial-mesenchymal transition in the airways of mice in the IQOS group. In conclusion, chronic exposure to IQOS aerosol results in impaired pulmonary function and lung tissue damage; hence, concern should be raised regarding the long-term safety of this product.
Asunto(s)
Aerosoles y Gotitas Respiratorias , Productos de Tabaco , Animales , Ratones , Pulmón/patología , Ratones Endogámicos C57BL , Aerosoles y Gotitas Respiratorias/química , Nicotiana , Productos de Tabaco/efectos adversos , Contaminación por Humo de Tabaco/efectos adversos , Inflamación/inducido químicamente , Inflamación/metabolismo , Estrés OxidativoRESUMEN
The phase state of respiratory aerosols and droplets has been linked to the humidity-dependent survival of pathogens such as SARS-CoV-2. To inform strategies to mitigate the spread of infectious disease, it is thus necessary to understand the humidity-dependent phase changes associated with the particles in which pathogens are suspended. Here, we study phase changes of levitated aerosols and droplets composed of model respiratory compounds (salt and protein) and growth media (organic-inorganic mixtures commonly used in studies of pathogen survival) with decreasing relative humidity (RH). Efflorescence was suppressed in many particle compositions and thus unlikely to fully account for the humidity-dependent survival of viruses. Rather, we identify organic-based, semisolid phase states that form under equilibrium conditions at intermediate RH (45 to 80%). A higher-protein content causes particles to exist in a semisolid state under a wider range of RH conditions. Diffusion and, thus, disinfection kinetics are expected to be inhibited in these semisolid states. These observations suggest that organic-based, semisolid states are an important consideration to account for the recovery of virus viability at low RH observed in previous studies. We propose a mechanism in which the semisolid phase shields pathogens from inactivation by hindering the diffusion of solutes. This suggests that the exogenous lifetime of pathogens will depend, in part, on the organic composition of the carrier respiratory particle and thus its origin in the respiratory tract. Furthermore, this work highlights the importance of accounting for spatial heterogeneities and time-dependent changes in the properties of aerosols and droplets undergoing evaporation in studies of pathogen viability.
Asunto(s)
Cloruro de Calcio/química , Modelos Químicos , Aerosoles y Gotitas Respiratorias/química , SARS-CoV-2/química , Albúmina Sérica/química , Cloruro de Sodio/química , COVID-19/virología , Difusión , Desinfección/métodos , Humanos , Humedad , Cinética , Viabilidad Microbiana , Transición de Fase , Propiedades de SuperficieRESUMEN
The cross-sectional study assessed knowledge, attitudes, and preventive practices toward COVID-19 disease of incarcerated people. A total of 685 subjects were surveyed. 94% were aware that respiratory droplets are involved in the transmission of COVID-19, and 77.2% that patients with chronic conditions are at risk of a more severe disease. Overall, 92.7% of respondents considered COVID-19 a more severe disease compared to influenza, and 85.4% believed that COVID-19 could cause serious consequences in their institution. Only 22.6% were self-confident about their ability to protect themselves from SARS-CoV-2 infection. This attitude was significantly higher in those who were involved in working activities in the institution, who did not report at least one common symptom compatible with COVID-19 in the previous 3 months, who did not show generalized anxiety symptoms, and did not need additional information. 63.9% of incarcerated people expressed willingness to receive COVID-19 vaccination. Older subjects, who knew that a COVID-19 vaccination is available, believed that COVID-19 is more serious than influenza, and were self-confident about their ability to protect themselves from SARS-CoV-2 infection, were significantly more willing to undergo COVID-19 vaccination. Public health response to COVID-19 in prisons should address vaccine hesitancy to increase vaccine confidence among incarcerated people.
Asunto(s)
Vacunas contra la COVID-19/administración & dosificación , COVID-19/psicología , Conocimientos, Actitudes y Práctica en Salud , Prisioneros/psicología , SARS-CoV-2/aislamiento & purificación , Vacilación a la Vacunación/psicología , Vacunación/psicología , Adolescente , Adulto , Anciano , COVID-19/epidemiología , COVID-19/prevención & control , COVID-19/virología , Estudios Transversales , Femenino , Humanos , Italia/epidemiología , Masculino , Persona de Mediana Edad , Aerosoles y Gotitas Respiratorias/química , Encuestas y Cuestionarios , Adulto JovenRESUMEN
Manual facemask ventilation, a core component of elective and emergency airway management, is classified as an aerosol-generating procedure. This designation is based on one epidemiological study suggesting an association between facemask ventilation and transmission during the SARS-CoV-1 outbreak in 2003. There is no direct evidence to indicate whether facemask ventilation is a high-risk procedure for aerosol generation. We conducted aerosol monitoring during routine facemask ventilation and facemask ventilation with an intentionally generated leak in anaesthetised patients. Recordings were made in ultraclean operating theatres and compared against the aerosol generated by tidal breathing and cough manoeuvres. Respiratory aerosol from tidal breathing in 11 patients was reliably detected above the very low background particle concentrations with median [IQR (range)] particle counts of 191 (77-486 [4-1313]) and 2 (1-5 [0-13]) particles.l-1 , respectively, p = 0.002. The median (IQR [range]) aerosol concentration detected during facemask ventilation without a leak (3 (0-9 [0-43]) particles.l-1 ) and with an intentional leak (11 (7-26 [1-62]) particles.l-1 ) was 64-fold (p = 0.001) and 17-fold (p = 0.002) lower than that of tidal breathing, respectively. Median (IQR [range]) peak particle concentration during facemask ventilation both without a leak (60 (0-60 [0-120]) particles.l-1 ) and with a leak (120 (60-180 [60-480]) particles.l-1 ) were 20-fold (p = 0.002) and 10-fold (0.001) lower than a cough (1260 (800-3242 [100-3682]) particles.l-1 ), respectively. This study demonstrates that facemask ventilation, even when performed with an intentional leak, does not generate high levels of bioaerosol. On the basis of this evidence, we argue facemask ventilation should not be considered an aerosol-generating procedure.
Asunto(s)
Máscaras , Aerosoles y Gotitas Respiratorias/química , Adulto , Anciano , Tos/etiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Coronavirus Relacionado al Síndrome Respiratorio Agudo Severo/aislamiento & purificación , Síndrome Respiratorio Agudo Grave/patología , Síndrome Respiratorio Agudo Grave/virologíaRESUMEN
The COVID-19 pandemic has reintroduced questions regarding the potential risk of SARS-CoV-2 exposure amongst passengers on an aircraft. Quantifying risk with computational fluid dynamics models or contact tracing methods alone is challenging, as experimental results for inflight biological aerosols is lacking. Using fluorescent aerosol tracers and real time optical sensors, coupled with DNA-tagged tracers for aerosol deposition, we executed ground and inflight testing on Boeing 767 and 777 airframes. Analysis here represents tracer particles released from a simulated infected passenger, in multiple rows and seats, to determine the exposure risk via penetration into breathing zones in that row and numerous rows ahead and behind the index case. We present here conclusions from 118 releases of fluorescent tracer particles, with 40+ Instantaneous Biological Analyzer and Collector sensors placed in passenger breathing zones for real-time measurement of simulated virus particle penetration. Results from both airframes showed a minimum reduction of 99.54% of 1 µm aerosols from the index source to the breathing zone of a typical passenger seated directly next to the source. An average 99.97 to 99.98% reduction was measured for the breathing zones tested in the 767 and 777, respectively. Contamination of surfaces from aerosol sources was minimal, and DNA-tagged 3 µm tracer aerosol collection techniques agreed with fluorescent methodologies.
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Aeronaves , Simulación por Computador , Colorantes Fluorescentes/química , Aerosoles y Gotitas Respiratorias/química , COVID-19/patología , COVID-19/prevención & control , COVID-19/virología , ADN/química , ADN/metabolismo , Humanos , Máscaras , Microesferas , Aerosoles y Gotitas Respiratorias/virología , SARS-CoV-2/genética , SARS-CoV-2/aislamiento & purificaciónRESUMEN
Flexible actuation of droplets is crucial for biomedical and industrial applications. Hence, various approaches using optical, electrical, and magnetic forces have been exploited to actuate droplets. For broad applicability, an ideal approach should be programmable and be able to actuate droplets of arbitrary size and composition. Here we present an "additive-free" magnetic actuation method to programmably manipulate droplets of water, organic, and biological fluids of arbitrary composition, as well as solid samples, on a ferrofluid-infused porous surface. We specifically exploit the spontaneously formed ferrofluid wetting ridges to actuate droplets using spatially varying magnetic fields. We demonstrate programmed processing and analysis of biological samples in individual drops as well as the collective actuation of large ensembles of micrometer-sized droplets. Such model respiratory droplets can be accumulated for improved quantitative and sensitive bioanalysis - an otherwise prohibitively difficult task that may be useful in tracking coronavirus.
Asunto(s)
Nanopartículas Magnéticas de Óxido de Hierro/química , Técnicas Analíticas Microfluídicas/métodos , Coloides/química , Humanos , Campos Magnéticos , Técnicas Analíticas Microfluídicas/instrumentación , Porosidad , Aerosoles y Gotitas Respiratorias/química , Aerosoles y Gotitas Respiratorias/microbiología , Propiedades de Superficie , HumectabilidadRESUMEN
Understanding the interactions between viruses and surfaces or interfaces is important, as they provide the principles underpinning the cleaning and disinfection of contaminated surfaces. Yet, the physics of such interactions is currently poorly understood. For instance, there are longstanding experimental observations suggesting that the presence of air-water interfaces can generically inactivate and kill viruses, yet the mechanism underlying this phenomenon remains unknown. Here we use theory and simulations to show that electrostatics may provide one such mechanism, and that this is very general. Thus, we predict that the electrostatic free energy of an RNA virus should increase by several thousands of kBT as the virion breaches an air-water interface. We also show that the fate of a virus approaching a generic liquid-liquid interface depends strongly on the detailed balance between interfacial and electrostatic forces, which can be tuned, for instance, by choosing different media to contact a virus-laden respiratory droplet. Tunability arises because both the electrostatic and interfacial forces scale similarly with viral size. We propose that these results can be used to design effective strategies for surface disinfection.
Asunto(s)
Aire , Desinfección , Virus ARN/química , Aerosoles y Gotitas Respiratorias/química , Agua , Interacciones Hidrofóbicas e Hidrofílicas , Aerosoles y Gotitas Respiratorias/virología , Electricidad Estática , Propiedades de SuperficieRESUMEN
The fermentation of dietary fibre (DF) leads to the production of bioactive metabolites, the most volatile ones being excreted in the breath. The aim of this study was to analyze the profile of exhaled breath volatile metabolites (BVM) and gastrointestinal symptoms in healthy volunteers after a single ingestion of maltodextrin (placebo) versus chitin-glucan (CG), an insoluble DF previously shown to be fermented into short-chain fatty acids (SCFA) by the human microbiota in vitro. Maltodextrin (4.5 g at day 0) or CG (4.5 g at day 2) were added to a standardized breakfast in fasting healthy volunteers (n = 15). BVM were measured using selected ion flow tube mass spectrometry (SIFT-MS) throughout the day. A single ingestion of 4.5 g CG did not induce significant gastrointestinal discomfort. Untargeted metabolomics analysis of breath highlighted that 13 MS-fragments (among 408 obtained from ionizations of breath) discriminated CG versus maltodextrin acute intake in the posprandial state. The targeted analysis revealed that CG increased exhaled butyrate and 5 other BVM - including the microbial metabolites 2,3-butanedione and 3-hydroxybutanone - with a peak observed 6 h after CG intake. Correlation analyses with fecal microbiota (Illumina 16S rRNA sequencing) spotlighted Mitsuokella as a potential genus responsible for the presence of butyric acid, triethylamine and 3-hydroxybutanone in the breath. In conclusion, measuring BMV in the breath reveals the microbial signature of the fermentation of DF after a single ingestion. This protocol allows to analyze the time-course of released bioactive metabolites that could be proposed as new biomarkers of DF fermentation, potentially linked to their biological properties. Trial registration: Clinical Trials NCT03494491. Registered 11 April 2018 - Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT03494491.