Histological damage

Allopurinol has been shown to attenuate lipid peroxidation in ethanol-fed rats (Kato etal., 1990). However, this was not correlated with any possible effect on histological damage and, as discussed previously, the significance of lipid peroxidation is unclear. Despite the evidence suggesting that oxidative stress and increased oxidative metabolism may play a role in the pathogenesis of human alcoholic liver disease, it remains to be shown that treatment with specific antioxidants will modify this process. 

LABORATORY WHITE RAT Diet No adverse effect level Lowest adverse effect level (histological damage) 4.0 mg/kg ration, equivalent to 0.29-0.38 mg toxaphene/kg body weight daily (Chu etal. 1988) 20.0 mg/kg ration (Chu etal. 1988)... 

All compounds used had equivalent purity (see Table 11). The test design was focused on the evaluation of histological differences after a tamponade time of 6 weeks. The density of the PFCLs used was 1.32 g/ml (perfluorobutylbutane), 1.62 g/ml (perfluorohexyl-ethane) and 1.78 g/ml (PFO). There was no dose-response relationship that means there is no evidence that a higher density creates more severe histological damage. Therefore, the simple explanation of the insufficient long-term tolerance for PFCLs could not be verified. 

Lowest adverse effect level (histological damage)... 

Sprague-Dawley rats exposed to toluene (982 52 ppm [3700 196 mg/m ], 18 h per day, on seven days per week for 61 days) showed no evidence of histological damage to the testes two weeks or 10 months after cessation of the exposure (Nylen et al., 1989). Toluene (the concentration of which decreased during the incubations) did not induce malformations in explanted rat embryos at the highest concentrations tested (0.23-0.09 mg/L), but retarded the growth of the embryos at the lowest concentration tested (0.05-0.02 mg/L) (Brown-Woodman et al., 1991). 

White Phosphorus Smoke. There is limited information on the potential of white phosphoms smoke to induce dermal effects. No human exposure studies examining dermal end points were located. In rats, no histological damage in the skin was observed following inhalation exposure to 1,742 mg orthophosphoric acid equivalents/m315 minutes/day, 5 days/week, for 13 weeks (Brown et al. 1981). 

Frye and Cucuel 1969). Histological damage in the brain has also been observed in humans acutely ingesting white phosphorus (Humphreys and Halpert 1931 Rao and Brown 1974 Wertham 1932) and in rabbits receiving intravenous injections of phosphorus for an intermediate duration (Ferraro et al. 1938). 

The potential for tissue damage is based on the likely incidence of it occurring and the severity of any sequelae, (e.g., inflammatory reaction or histological damage). 

If heavy metal poisoning is suspected, the kidneys often show histological damage due to the metal, and also the metals causing the damage tend to concentrate in the kidneys. If the metal poisoning is suspected of being a chronic condition, then s[Pg.113]

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