Donald H. Beezhold

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Influenza is thought to be communicated from person to person by multiple pathways. However, the relative importance of different routes of influenza transmission is unclear. To better understand the potential for the airborne spread of influenza, we measured the amount and size of aerosol particles containing influenza virus that were produced by coughing.(More)
BACKGROUND The role of relative humidity in the aerosol transmission of influenza was examined in a simulated examination room containing coughing and breathing manikins. METHODS Nebulized influenza was coughed into the examination room and Bioaerosol samplers collected size-fractionated aerosols (<1 µM, 1-4 µM, and >4 µM aerodynamic diameters) adjacent(More)
Occupational exposure to high-molecular-weight allergens is a risk factor for the development and pathogenesis of IgE-mediated respiratory disease. In some occupational environments, workers are at an increased risk of exposure to fungal enzymes used in industrial production. Fungal enzymes have been associated with adverse health effects in the work place,(More)
Pulmonary exposure to Aspergillus fumigatus has been associated with morbidity and mortality, particularly in immunocompromised individuals. A. fumigatus conidia produce β-glucan, proteases, and other immunostimulatory factors upon germination. Murine models have shown that the ability of A. fumigatus to germinate at physiological temperature may be an(More)
Fibronectin (Fn) fragments have recently been shown to stimulate tumor necrosis factor (TNF) secretion by human monocytes. In this study, we investigated the signal transduction mechanisms involved in Fn-induced TNF secretion. Treatment of human monocytes with Fn120, a chymotryptic cell-binding fragment of plasma Fn, failed to cause a detectable rise in(More)
BACKGROUND The potential for human influenza viruses to spread through fine particle aerosols remains controversial. The objective of our study was to determine whether influenza viruses could be detected in fine particles in hospital rooms. METHODS AND FINDINGS We sampled the air in 2-bed patient isolation rooms for four hours, placing cyclone samplers(More)
BACKGROUND Chronic rhinosinusitis (CRS) is a societal burden and cause of morbidity in Canada; however, the prevalence of allergic sensitization in Canadian CRS patients has remained poorly characterized. OBJECTIVE In this study, we used skin prick test (SPT) and specific immunoglobulin E (sIgE) and G (sIgG) titers to regionally relevant allergen sources(More)
BACKGROUND To prepare for a possible influenza pandemic, a better understanding of the potential for the airborne transmission of influenza from person to person is needed. OBJECTIVES The objective of this study was to directly compare the generation of aerosol particles containing viable influenza virus during coughs and exhalations. METHODS Sixty-one(More)
Most murine models of fungal exposure are based on the delivery of uncharacterized extracts or liquid conidia suspensions using aspiration or intranasal approaches. Studies that model exposure to dry fungal aerosols using whole body inhalation have only recently been described. In this study, we aimed to characterize pulmonary immune responses following(More)