Publications by authors named "Christopher W Stewart"
Clark et al. (accepted for publication) reported that a sample of field-matched fume condensate from a Type III built-up roofing asphalt (BURA) resulted in a carcinogenic response in a mouse skin bioassay, with relatively few tumor-bearing animals, long tumor latency and chronic skin irritation. This mouse skin initiation/promotion study was conducted to assess possible mechanisms, i.
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- The study assessed the carcinogenic effects of asphalt fume condensates on male C3H/HeNCrl mice over two years, using samples from both paving and built-up roofing asphalt.
- The paving fume condensate showed no significant carcinogenic effects, with only one benign tumor found among 80 mice, while the lab-generated BURA condensate led to a significant increase in squamous cell carcinomas in 55% of subjects.
- The field-matched BURA condensate also caused tumors but to a lesser extent, along with confirmed skin irritation in both types of BURA condensates.
The incidence of marginal biotin deficiency in normal human gestation is approximately one in three. In ICR mice, maternal biotin deficiency results in cleft palate, micrognathia, microglossia and limb hypoplasia. However, the relationships among the severity of maternal biotin deficiency, fetal biotin status and malformations have not been reported.
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