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13 recordsLinked to original sources
PubMed2025

Modeling airborne transmission of viral genome using computational fluid dynamics simulation: A case study for SARS-CoV-2 virus.

Predicting indoor air quality during infectious disease conditions relies on models simulating particle materials (PM)/bioaerosols distribution. Understanding the thermo-fluid properties of exhaled air is crucial for comprehending disease transmission dynamics. This study employs a computational fluid dynamics (CFD) model to simulate cough-induced particle dispersion in a closed space. Furthermore, the number of released particles and the presence of SARS-CoV-2 viral genomes by a cough were assessed (in eight COVID-19 patients). According to the CFD model, in the first 30 s of cough, the vertical height and lateral breadth of the particles' dispersion were up to 138cm and 92cm, respectively. As the distance from the patient's respiratory zone increased, the lateral distribution width of particles expanded, reaching 1.3 m at 2.4 m away. Larger droplets (> 62.5µ) were deposited at shorter distances, while smaller particles remained airborne longer. The comparison of experimental and simulated results focused on particle dispersion at specific distances from the patient, particularly in the 2.5µ range. The distribution pattern of PM2.5 and PM10 at a distance of 1 and 2 m for women, not men, is similar to the distribution pattern of PM in CFD modeling. Viral genome detection was more prevalent in particles near the left side of the body, especially within the first 20 min post-cough, exhibiting a correlation with CFD predictions.

Airborne transmission↗
PubMed1978

[A pneumatic generator of aerosols for group vaccination (author's transl)].

It is given the description of a pneumatic generator of Aerosols--with the basical technical data--designed and built by the authors of this paper. The generator is used for producing aerosols for simultaneous vaccination of animals. Electrization of the aerosols contribute to a higher stability of the droplets and also to their longer retainment in the respiratory organs.

Aerosols↗
PubMed1975

Intrapulmonary airway morphology in three species of monkeys: a correlated scanning and transmission electron microscopic study.

Intrapulmonary airways were studied in rhesus (Macaca mulatta), stumptail (Macaca arctoides), and bonnet (Macaca radiata) monkeys by correlated scanning and transmission electron microscopy. Lobar, segmental, and subsegmental bronchi in all three macaques were lined by pseudostratified columnar epithelium composed primarily of ciliated cells, mucous cells, and basal cells. Neuronal processes and cells containing dense-core vesicles were also observed. Terminal bronchioles in bonnet and stumptail monkeys were lined by ciliated pseudostratified columnar epithelium which included nonciliated branchiolar epithelial (Clara) cells. The arrangement of epithelium in terminal bronchioles differed slightly in rhesus monkeys. All three species had long respiratory bronchioles. They were lined by simple, nonciliated cuboidal and squamous epithelium which usually did not contain secretory droplets. Capillaries were often observed immediately below the luminal epithelium. Cuboidal cells containing dense-core vesicles were a rare component of the epithelium of respiratory bronchioles in stumptail monkeys. Alveolar ducts were lined by an epithelium composed of type I and type II cells. The results of this study indicate that there is general similarity in the mucosal structure of bronchi and respiratory bronchioles between macaques and man but that there are differences in the number of generations and epithelial lining of terminal bronchioles.

Animals↗
PubMed1979

[Physical conditions favouring the trapping of submicron particles in the upper airways (author's transl)].

The present communication is based on the hypothesis that temperature gradients can exist in the upper airways, even in the trachea. Membranes lining these passages remaining physiologically humid, a mechanism of formation and growth of micron sized droplets can take place, exactly similar to the basic mechanism of the counting chamber of cloud condensation nuclei. Therefore through the catching of droplets by vibrating cilia, it can contribute to the protection of the deep respiratory system. A careful investigation of the regions where thermal gradients can occur, should enable to confirm the reality of this process, at least for some respiratory modes.

Humans↗
PubMed1977

[Investigations on the stability of droplets from medical jet and ultrasound aerosol atomizers (author's transl)].

The droplet size distribution of aerosols is not only determined by the process of aerosol production. After generation of an aerosol its spectrum undergoes very rapid changes due to vaporization and condensation process, that result in a spectrum depending on type and concentration of the used medicament and the partial pressure of water vapour in the vicinity of the droplets. The resulting spectrum is measured and calculated.

Aerosols↗
PubMed2026

A rapid CRISPR-based nanodroplet assay enables direct clinical identification of mycobacteria species.

The global incidence and mortality of nontuberculous mycobacterial infections have risen sharply with population aging. In some regions, they are now surpassing Mycobacterium tuberculosis complex infections, imposing a substantial clinical and economic burden. Because nontuberous mycobacteria exhibit species-level heterogeneity and require prolonged culture for identification, their diagnosis remains slow and is frequently inaccurate. Here, we describe a multiplexed clustered regularly interspaced short palindromic repeats (CRISPR)-assisted nanodroplet differential identification (CANDI) diagnostic platform that integrates species-agnostic target amplification with species-specific CRISPR-associated protein 12a (Cas12a) detection in fluorescence-barcoded nanodroplets. By spatially compartmentalizing CRISPR reactions into color-encoded nanodroplets, CANDI overcomes the multiplexing limitations of conventional CRISPR diagnostics and enables simultaneous interrogation of multiple mycobacterial targets in a single assay. We designed a 16-plex panel that distinguishes 15 clinically relevant Mycobacterium species and subspecies. CANDI achieved high analytical sensitivity and accurate discrimination in samples containing coinfections with multiple species or subspecies. When applied to 230 clinical specimens, including sputum, tracheal aspirates, and other respiratory fluids, CANDI delivered subspecies-level results within 3.5 hours, achieving 97.08% sensitivity and 99.7% specificity relative to culture-based identification. By combining multiplexed, high-specificity CRISPR detection with scalable droplet-based engineering, CANDI has the potential to overcome the culture dependency of current diagnostics and enable species- and subspecies-level identification across the genetically complex Mycobacterium genus, offering a clinically adaptable framework for rapid, precision diagnosis of mycobacterial infections.

Humans↗
PubMed1978

Acute experimental autologous fat embolism in dogs.

An experimental technique has been devised to study the acute respiratory and hemodynamic results of autologous fat embolism in dogs. By using a commercially available autotransfusion device, fat can be aspirated and reinfused into the venous circulation. Acute rises in pulmonary artery pressure and calculated pulmonary dead space can be produced, and arterial oxygen saturation is impaired. These changes correlate well with the appearance of intravascular embolized fat. Apparent intravascular clot formation is demonstrated, the fat droplet acting as a stimulus or nidus for clot formation. These changes were avoided when the infusate was first passed through a micropore filter.

Animals↗
PubMed1978

Control of nosocomial respiratory syncytial viral infections.

We evaluated methods to control the spread of respiratory syncytial virus (RSV) on our infants' ward during a community outbreak of RSV infection. Methods included isolation and cohorting of infected infants, strict handwashing, use of gowns, and the cohorting of staff to the ill infants. Of 123 infants studied, 36 were admitted with RSV infections. Of the remaining 87 contact infants, eight (19%) acquired nosocomial RSV disease. Three of the eight developed pneumonia and one died. Of the 43 staff members, 24 (56%) became infected and 82% were symptomatic. Four acquired repeated infections within weeks of the initial infection. Studies a year previously had revealed that 45% of contact infants and 42% of the staff had acquired nosocomial RSV infections. Thus, the employed procedures appeared to have decreased the transmission of RSV to infants but not to the staff. Staff may continue to be infected by large droplets from close contact with ill infants or by self-inoculation of contaminated secretions.

Antisepsis↗
PubMed1978

Bronchial mucus hypersecretion induced by elastase in hamsters: ultrastructural appearances.

Male golden hamsters were exposed to a solution of purified pancreatic elastase by intratracheal injection. They developed panlobular (panacinar) emphysema and, in addition, were found to show severe goblet cell metaplasia in the major bronchi. The metaplastic change in the respiratory epithelium was associated with persistence of a fenestrated sheet of mucus, widely present throughout the bronchial tree, which was greater in amount than that in either unexposed or saline exposed controls. Transmission electron micrography showed a striking increase in size of individual goblet cells, due to increased numbers of secretory droplets which were also much larger and paler than in control bronchi. Ciliated cells appeared smaller than normal due to compression by the swollen goblet cells. The presence of prominent dilatation of the endoplasmic reticulum and the increased frequency of secretory droplet release from the luminal surface stronly suggest that the goblet cell changes were due to increased formation and secretion of mucus into the damaged bronchi. These experiments show that a single exposure to elastase produces both severe panlobular emphysema and goblet cell metaplasia. The changes resemble several of the anatomic features of chronic obstructive lung disease in man for which this injury may be a suitable model.

Animals↗
PubMed2024

Dysregulated cytokine and oxidative response in hyper-glycolytic monocytes in obesity.

INTRODUCTION: Obesity is associated with a plethora of health complications, including increased susceptibility to infections or decreased vaccine efficacy, partly due to dysregulated immune responses. Monocytes play a crucial role in innate immunity, yet their functional alterations in obesity remain poorly understood. METHODS: Here, we employed proteomic and metabolomic analyses to investigate monocyte characteristics in individuals with overweight, obesity, impaired glucose tolerance (IGT), and type 2 diabetes (T2D), compared to lean donors. RESULTS AND DISCUSSION: Our results revealed distinct molecular signatures in monocytes from individuals with obesity, with significant alterations in pathways related to metabolism, cellular migration, and phagocytosis. Moreover, LPS-induced activation of monocytes unveiled heightened metabolic reprogramming towards glycolysis in subjects with obesity accompanied by dysregulated cytokine responses and elevated oxidative stress. Additionally, monocytes from donors with obesity exhibited increased lipid droplet accumulation. These findings shed light on the immunometabolic dysregulation underlying obesity-associated immune dysfunction, highlighting potential targets for therapeutic intervention.

Humans↗
PubMed1978

Aerodynamic size distribution of metered-dose bronchodilator aerosols.

The aerodynamic size distributions of 9 commonly used bronchodilator aerosols were determined by using a new instrument, the single-particle, aerodynamic relaxation time analyzer, which can measure the aerodynamic size of single particles and droplets in real time independent of density, shape, and other physical characteristics. The following commercial preparations were studied: Duo-Medihaler, Medihaler-Epi, Medihaler-Epi Medihaler-Iso, Norisodrine Aerotrol, Alupent, Metaprel, Isuprel Mistometer, Bronkometer, and Asthma-Meter. Count median diameters ranged from 0.62 to 0.82 micrometer, and mass median aerodynamic diameters ranged from 2.8 to 4.3 micrometer. The heterodisperse nature of the aerosols was demonstrated by the relatively large geometric standard deviations, which ranged from 1.5 to 2.1. None of these aerosols had a log-normal distribution; rather, the distribution curves were multimodal.

Aerosols↗