Last data update: May 06, 2024. (Total: 46732 publications since 2009)
Records 1-3 (of 3 Records) |
Query Trace: Di Giuseppe M[original query] |
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Occupational Histoplasmosis: Epidemiology and Prevention Measures
de Perio MA , Benedict K , Williams SL , Niemeier-Walsh C , Green BJ , Coffey C , Di Giuseppe M , Toda M , Park JH , Bailey RL , Nett RJ . J Fungi (Basel) 2021 7 (7) In areas where Histoplasma is endemic in the environment, occupations involving activities exposing workers to soil that contains bird or bat droppings may pose a risk for histoplasmosis. Occupational exposures are frequently implicated in histoplasmosis outbreaks. In this paper, we review the literature on occupationally acquired histoplasmosis. We describe the epidemiology, occupational risk factors, and prevention measures according to the hierarchy of controls. |
Differential activation of RAW 264.7 macrophages by size-segregated crystalline silica
Mischler SE , Cauda EG , Di Giuseppe M , McWilliams LJ , St Croix C , Sun M , Franks J , Ortiz LA . J Occup Med Toxicol 2016 11 57 BACKGROUND: Occupational exposure to crystalline silica is a well-established occupational hazard. Once in the lung, crystalline silica particles can result in the activation of alveolar macrophages (AM), potentially leading to silicosis, a fibrotic lung disease. Because the activation of alveolar macrophages is the beginning step in a complicated inflammatory cascade, it is necessary to define the particle characteristics resulting in this activation. The aim of this research was to determine the effect of the size of crystalline silica particles on the activation of macrophages. METHODS: RAW 264.7 macrophages were exposed to four different sizes of crystalline silica and their activation was measured using electron microscopy, reactive oxygen species (ROS) generation by mitochondria, and cytokine expression. RESULTS: These data identified differences in particle uptake and formation of subcellular organelles based on particle size. In addition, these data show that the smallest particles, with a geometric mean of 0.3 mum, significantly increase the generation of mitochondrial ROS and the expression of cytokines when compared to larger crystalline silica particles, with a geometric mean of 4.1 mum. CONCLUSION: In summary, this study presents novel data showing that crystalline silica particles with a geometric mean of 0.3 mum enhance the activation of AM when compared to larger silica particles usually represented in in vitro and in vivo research. |
A multi-cyclone sampling array for the collection of size-segregated occupational aerosols
Mischler SE , Cauda EG , Di Giuseppe M , Ortiz LA . J Occup Environ Hyg 2013 10 (12) 685-93 In this study a serial multi-cyclone sampling array capable of simultaneously sampling particles of multiple size fractions, from an occupational environment, for use in in vivo and in vitro toxicity studies and physical/chemical characterization, was developed and tested. This method is an improvement over current methods used to size-segregate occupational aerosols for characterization, due to its simplicity and its ability to collect sufficient masses of nano- and ultrafine sized particles for analysis. This method was evaluated in a chamber providing a uniform atmosphere of dust concentrations using crystalline silica particles. The multi-cyclone sampling array was used to segregate crystalline silica particles into four size fractions, from a chamber concentration of 10 mg/m(3). The size distributions of the particles collected at each stage were confirmed, in the air, before and after each cyclone stage. Once collected, the particle size distribution of each size fraction was measured using light scattering techniques to further confirm the size distributions. As a final confirmation, scanning electron microscopy was used to collect images of each size fraction. The results presented here, using multiple measurement techniques, show that this multi-cyclone system was able to successfully collect distinct size-segregated particles at sufficient masses to perform toxicological evaluations and physical/chemical characterization. |
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