Optimization of Aspergillus versicolor Culture and Aerosolization in a Murine Model of Inhalational Fungal Exposure.

Aspergillus versicolor is ubiquitous in the environment and is particularly abundant in damp indoor spaces. Exposure to Aspergillus species, as well as other environmental fungi, has been linked to respiratory health outcomes, including asthma, allergy, and even local or disseminated infection. However, the pulmonary immunological mechanisms associated with repeated exposure to A. versicolor have remained relatively uncharacterized. Here, A. versicolor was cultured and desiccated on rice then placed in an acoustical generator system to achieve aerosolization. Mice were challenged with titrated doses of aerosolized conidia to examine deposition, lymphoproliferative properties, and immunotoxicological response to repeated inhalation exposures. The necessary dose to induce lymphoproliferation was identified, but not infection-like pathology. Further, it was determined that the dose was able to initiate localized immune responses. The data presented in this study demonstrate an optimized and reproducible method for delivering A. versicolor conidia to rodents via nose-only inhalation. Additionally, the feasibility of a long-term repeated exposure study was established. This experimental protocol can be used in future studies to investigate the physiological effects of repeated pulmonary exposure to fungal conidia utilizing a practical and relevant mode of delivery. In total, these data constitute an important foundation for subsequent research in the field.

Characterization of an Electronic Nicotine Delivery System (ENDS) Aerosol Generation Platform to Determine Exposure Risks.

Evaluating vaping parameters that influence electronic nicotine delivery system (ENDS) emission profiles and potentially hazardous exposure levels is essential to protecting human health. We developed an automated multi-channel ENDS aerosol generation system (EAGS) for characterizing size-resolved particle emissions across pod- and mod-type devices using real-time monitoring instruments, an exposure chamber, and vaping parameters including different ventilation rates, device type and age, e-liquid formulation, and atomizer setup. Results show the ENDS device type, e-liquid flavoring, and nicotine content can affect particle emissions. In general, pod-type devices have unimodal particle size distributions and higher number emissions, while mod-type devices have bimodal size distributions and higher mass emissions. For pod-type devices, later puff fractions emit lower aerosols, which is potentially associated with the change of coil resistance and power during ageing. For a mod-type device, an atomizer with a lower resistance coil and higher power generates larger particle emissions than an atomizer with a greater resistance coil and lower power. The unventilated scenario produces higher particle emission factors, except for particle mass emission from pod-type devices. The data provided herein indicate the EAGS can produce realistic and reproducible puff profiles of pod- and mod-type ENDS devices and therefore is a suitable platform for characterizing ENDS-associated exposure risks.

Aerosol physicochemical determinants of carbon black and ozone inhalation co-exposure induced pulmonary toxicity.

Air pollution accounts for more than 7 million premature deaths worldwide. Using ultrafine carbon black (CB) and ozone (O3) as a model for an environmental co-exposure scenario, the dose response relationships in acute pulmonary injury and inflammation were determined by generating, characterizing, and comparing stable concentrations of CB aerosols (2.5, 5.0, 10.0 mg/m3), O3 (0.5, 1.0, 2.0 ppm) with mixture CB + O3 (2.5 + 0.5, 5.0 + 1.0, 10.0 + 2.0). C57BL6 male mice were exposed for 3 h by whole body inhalation and acute toxicity determined after 24 h. CB itself did not cause any alteration, however, a dose response in pulmonary injury/inflammation was observed with O3 and CB + O3. This increase in response with mixtures was not dependent on the uptake but was due to enhanced reactivity of the particles. Benchmark dose modeling showed several-fold increase in potency with CB + O3 compared with CB or O3 alone. Principal component analysis provided insight into response relationships between various doses and treatments. There was a significant correlation in lung responses with charge-based size distribution, total/alveolar deposition, oxidant generation, and antioxidant depletion potential. Lung tissue gene/protein response demonstrated distinct patterns that are better predicted by either particle dose/aerosol responses (interleukin-1ß, keratinocyte chemoattractant, transforming growth factor beta) or particle reactivity (thymic stromal lymphopoietin, interleukin-13, interleukin-6). Hierarchical clustering showed a distinct signature with high dose and a similarity in mRNA expression pattern of low and medium doses of CB + O3. In conclusion, we demonstrate that the biological outcomes from CB + O3 co-exposure are significantly greater than individual exposures over a range of aerosol concentrations and aerosol characteristics can predict biological outcome.

Electronic Cigarettes and Vaping-Associated Lung Injury (EVALI): A Rural Appalachian Experience.

Background: Electronic cigarette use has increased dramatically since their introduction in 2007. Respiratory complications, particularly lipoid pneumonia, have been reported as early as 2012. An outbreak of pulmonary injury in 2019 has been reported in patients using vaping products.Research Question: To describe a rural Appalachian tertiary center's experience of EVALI and to identify novel mechanisms of pulmonary injury patterns.Study Design and Methods: We present a consecutive case series of 17 patients admitted to our rural, academic, tertiary care institution with EVALI from August 2019 to March 2020. Demographics, baseline characteristics, co-morbidities, vaping behavior, and hospital course were recorded. Broncho-alveolar lavage specimens were assessed for lipid-laden macrophages and hemosiderin-laden macrophages with stains for Oil-Red-O (n = 15) and Prussian Blue (n = 14) respectively.The patient volunteered e-liquid materials (n = 6), and vapors were analyzed using a proton transfer reaction time-of-flight mass spectrometer (PTR-TOF-MS) to describe the chemical profile. Post-discharge interviews were conducted.Results: The most common CT finding was bilateral ground-glass opacities with a predilection for lower lung zones. The most frequent pulmonary injury pattern was lipoid pneumonia. The majority of EVALI patients were critically ill requiring ventilation or ECMO. The most severely ill patients were noted to be positive for iron stains in macrophages and showed higher volatile organic compound (VOC) levels in chemical analysis.Interpretation: Based on our experience, EVALI in rural Appalachia presented with relatively severe respiratory failure. Worse outcomes appear to be correlated to high levels of VOCs, iron deposition in lungs, and concomitant infection.

Metal working fluids: sub-chronic effects on pulmonary functions in B6C3F1 mice given vitamin E deficient and sufficient diets.

Metal working fluids (MWFs) have been widely known to cause asthma and neoplasia of the larynx, pancreas, rectum, skin and urinary bladder (Textbook of Clinical Occupational and Environmental Medicine (1994) 814; Am. J. Ind. Med. 32 (1997) 240; Am. J. Ind. Med. 33 (1997) 282; Am. J. Ind. Med. 22 (1994) 185). Other non-neoplastic respiratory effects in industrial workers attributed to MWFs include increased rates of cough, phlegm production, wheeze, chronic bronchitis and chest tightness (Eur. J. Resir. Dis. 63(118) (1982), 79; J. Occup. Med. 24 (1982) 473; Am. J. Ind. Med. 32 (1997) 450). The epidemic and endemic nature of immune mediated lung morbidity commonly known as hypersensitivity pneumonitis in workers from several different industries using MWFs has been well documented (J. Allergy clin. Immunol. 91 (1993) 311; Chest 108 (1995) 636; MMWR45 (1996) 606; Am. J. Ind. Med. 32 (1997) 423). We studied morphological/functional and antioxidant outcomes in lungs after inhalation exposure of vitamin E deficient mice to MWF (27 mg m(-3) 17 weeks, 5 days a week, 6 h a day). Mice were given vitamin E deficient (<10 IU kg(-1) vitamin E) or basal diets (50 IU kg(-1) vitamin E) for 35 weeks. Inhalation exposure to MWF started after 18 weeks on diet. Microscopic observation of lungs from mice given vitamin E deficient or sufficient diets revealed no inflammation or morphological alteration after exposure to MWF. Mice given vitamin E deficient diet exhibited a significant decrease (P<0.05) in breathing rate, peak inspiratory/expiratory flow, minute ventilation, and tidal volume compared with sufficient controls. However, no differences were found after exposure to MWF in pulmonary function, with the exception of tidal volume which also significantly decreased (P<0.05). Exposure to MWF reduced vitamin E, protein thiol and ascorbate level in lungs. Exposure to MWF in combination with a vitamin E deficient diet resulted in significantly enhanced accumulation of peroxidative products compared with vitamin E deficient controls. This is the first report that describes the increase of oxidative stress in the lungs after MWF exposure.