@entity455 in male B6C3F1 XXXX exposed to particulate matter by inhalation: studies conducted by the National Toxicology Program.

@entity1 @entity32 @entity8 @entity455 @entity66 @entity19 @entity18251 @entity3468 @entity7565 @entity43994 @entity70651
Epidemiological studies suggest an association between ambient particulate matter and @entity66 in @entity1 . The mechanisms underlying these health effects are poorly understood. To better understand the potential relationship between particulate-matter-induced @entity32 and @entity455 , a 2-phase retrospective study was conducted. Phase one included the review of heart, lung, and kidney tissues from high-dose and control male B6C3F1 @entity19 exposed by inhalation to 9 particulate compounds for a 2-year period. The results showed that high-dose males developed significantly increased incidences of @entity8 over controls in 2 of the 9 studies ( @entity70651 and @entity43994 ), while marginal increases in @entity3468 incidence was detected in 2 additional studies ( @entity18251 and @entity7565 ). In contrast, @entity3468 of the muscular arteries of the lung was not observed. Morphological features of @entity3468 in these studies included an influx of mixed inflammatory cells including neutrophils, lymphocytes, and macrophages. Partial and complete effacement of the normal vascular wall architecture, often with extension of the inflammatory process into the periarterial connective tissue, was observed. Phase 2 evaluated the heart, lung, kidney, and mesentery of male and female B6C3F1 @entity19 from the 90-day studies of the 4 compounds demonstrating @entity3468 after a 2-year period. The results showed @entity3468 did not develop in the 90-day studies, suggesting that long-term chronic exposure to lower-dose metallic particulate matter may be necessary to induce or exacerbate @entity3468 .
