Last data update: Jan 27, 2025. (Total: 48650 publications since 2009)
Records 1-2 (of 2 Records) |
Query Trace: Barger MW[original query] |
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Pulmonary toxicity following acute coexposures to diesel particulate matter and alpha-quartz crystalline silica in the Sprague-Dawley rat
Farris BY , Antonini JM , Fedan JS , Mercer RR , Roach KA , Chen BT , Schwegler-Berry D , Kashon ML , Barger MW , Roberts JR . Inhal Toxicol 2017 29 (7) 1-18 The effects of acute pulmonary coexposures to silica and diesel particulate matter (DPM), which may occur in various mining operations, were investigated in vivo. Rats were exposed by intratracheal instillation (IT) to silica (50 or 233 microg), DPM (7.89 or 50 microg) or silica and DPM combined in phosphate-buffered saline (PBS) or to PBS alone (control). At one day, one week, one month, two months and three months postexposure bronchoalveolar lavage and histopathology were performed to assess lung injury, inflammation and immune response. While higher doses of silica caused inflammation and injury at all time points, DPM exposure alone did not. DPM (50 microg) combined with silica (233 microg) increased inflammation at one week and one-month postexposure and caused an increase in the incidence of fibrosis at one month compared with exposure to silica alone. To assess susceptibility to lung infection following coexposure, rats were exposed by IT to 233 microg silica, 50 microg DPM, a combination of the two or PBS control one week before intratracheal inoculation with 5 x 105 Listeria monocytogenes. At 1, 3, 5, 7 and 14 days following infection, pulmonary immune response and bacterial clearance from the lung were evaluated. Coexposure to DPM and silica did not alter bacterial clearance from the lung compared to control. Although DPM and silica coexposure did not alter pulmonary susceptibility to infection in this model, the study showed that noninflammatory doses of DPM had the capacity to increase silica-induced lung injury, inflammation and onset/incidence of fibrosis. |
Pulmonary toxicity of indium-tin oxide production facility particles in rats
Badding MA , Fix NR , Orandle MS , Barger MW , Dunnick KM , Cummings KJ , Leonard SS . J Appl Toxicol 2015 36 (4) 618-26 Indium-tin oxide (ITO) is used to make transparent conductive coatings for touch-screen and liquid crystal display electronics. Occupational exposures to potentially toxic particles generated during ITO production have increased in recent years as the demand for consumer electronics continues to rise. Previous studies have demonstrated cytotoxicity in vitro and animal models have shown pulmonary inflammation and injury in response to various indium-containing particles. In humans, pulmonary alveolar proteinosis (PAP) and fibrotic interstitial lung disease have been observed in ITO facility workers. However, which indium materials or specific processes in the workplace may be the most toxic to workers is unknown. Here we examined the pulmonary toxicity of three different particle samples that represent real-life worker exposures, as they were collected at various production stages throughout an ITO facility. Indium oxide (In2 O3 ), sintered ITO (SITO) and ventilation dust (VD) particles each caused pulmonary inflammation and damage in rats over a time course (1, 7 and 90 days post-intratracheal instillation), but SITO and VD appeared to induce greater toxicity in rat lungs than In2 O3 at a dose of 1 mg per rat. Downstream pathological changes such as PAP and fibrosis were observed in response to all three particles 90 days after treatment, with a trend towards greatest severity in animals exposed to VD when comparing animals that received the same dose. These findings may inform workplace exposure reduction efforts and provide a better understanding of the pathogenesis of an emerging occupational health issue. |
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