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Biomedical subjects

G F Egan

Publications and source records attributed to G F Egan.

26 records · Page 2Linked to original sources
PubMed1984

Effect of C10-C11 isoparaffinic solvent on kidney function in Fischer 344 rats during eight weeks of inhalation.

Two groups of 50 male and 50 female Fischer 344 rats were exposed by inhalation to either 5.48 g/m3 (900 ppm) or 1.83 g/m3 (300 ppm) of C10-C11 isoparaffin (IP) 6 hr/day, 5 days/week for 8 weeks to evaluate renal function and histologic effects. Another group of rats (50/sex) was air exposed and served as controls. Urine and blood were collected from 10 male and 10 female rats of each group after 1, 4, and 8 weeks, and following a 4-week period of recovery. The ability of males to concentrate urine was reduced at 4 and 8 weeks of exposure to either level of IP. Following the 4-week recovery period, the urine concentrating ability of the exposed groups showed evidence of recovery. Following 4 and 8 weeks of exposure, glucose, protein, and epithelial cell excretion in urine of males was higher in the exposed groups than in that of controls. Creatinine clearance decreased after 8 weeks in the male high exposure group. After 4 weeks of recovery, urine glucose, protein, epithelial cell exfoliation, and creatinine clearance returned to control levels in exposed male rats. Overall, the effect on kidney function in male rats was mild, with evidence of near complete recovery. Histologic changes in exposed male rats compared to controls included an increased incidence of regenerative tubular epithelia and tubules dilated at the corticomedullary junction with proteinaceous debris in the tubules. No functional or histologic changes were observed in exposed female rats.

Animals↗
PubMed1984

Subchronic inhalation exposure of dearomatized white spirit and C10-C11 isoparaffinic hydrocarbon in Sprague-Dawley rats.

Groups of 35 male and 35 female Sprague-Dawley rats were exposed to either Dearomatized White Spirit (DAWS) vapor at concentrations of 1.97 and 5.61 g/m3 or C10-C11 Isoparaffinic Hydrocarbon (IPH) vapor at concentrations of 1.91 and 5.62 g/m3. These concentrations were targeted for the recommended occupational exposure limits and three times that value, respectively. Exposures were 6 hr-day, 5 days/week for 12 weeks. Following Weeks 4, 8, and 12 of exposure, a total of 10, 10, and 15 rats, respectively, from each group were sacrificed. Clinical chemistry and hematology parameters were measured in blood samples taken immediately prior to sacrifice, and selected organs were removed and weighted. Twenty-three organs and tissues from each animal were examined microscopically. There were no deaths during the course of this study related to either DAWS or IPH. Mean body weights were significantly lower than controls in male rats following exposure to 5.61 g/m3 DAWS, and 5.62 or 1.91 g/m3 IPH. Body weights were not affected in females. The primary effects from DAWS or IPH exposure were observed in the kidneys of male rats only from both exposure groups beginning at Week 4. Evidence of mild tubular toxicity, such as regenerative tubular epithelia and dilated tubules containing proteinaceous casts, was observed at the corticomedullary junction. The incidence and severity appeared to increase with increasing concentration and exposure duration. There were scattered instances of statistically significant increases in liver and kidney weights in both males and females. With the exception of the mild male rat tubular nephrotoxicity, other significant toxic effects were not observed at levels tested.

Alkanes↗
PubMedDate not supplied

Subchronic toxicity study of dicyclopentadiene vapor in rats.

Fischer 344 rats were exposed by inhalation to 0, 1, 5 or 50 ppm dicyclopentadiene (DCPD) vapor 6 hr/day, 5 days/week for 13 weeks, followed by a 13-week recovery period. Animals were euthanized following completion of exposure at 2, 6, or 13 weeks and at postexposure weeks 4 or 13. No mortality, overt signs, body weight changes, hematologic or clinical chemistry values were related to DCPD exposure. In the high-exposure male rats, relative liver weights were significantly increased but with no accompanying histopathologic changes. Exposure to DCPD produced adverse kidney effects in male, but not female, rats as evidenced by the excretion of epithelial cells in the urine. Histologic changes were localized to the proximal tubules of the kidney and included increased accumulation of protein droplets, regenerative epithelium, and the presence of intraluminal proteinaceous material. In addition, several alterations in renal function were observed. Urinary Na+ excretion rates were decreased and urinary K+ excretion rates were increased throughout the exposure period; however, glucose was not present in the urine, and creatinine clearance was normal. The ability of the kidney to concentrate urine was also impaired. After the recovery period, many of the treatment-related kidney effects were not observed, including the presence of hyaline droplets in the proximal tubules and epithelial cells in the urine. These findings indicate an overall low degree of systemic toxicity following subchronic inhalation exposure of dicyclopentadiene at exposure levels up to 50 ppm. The only effect that was observed was a male rat-specific nephropathy that is characteristic of the hyaline droplet nephropathy produced by a diverse group of compounds.

Administration, Inhalation↗