Skeletal variations

Increased abortion rate no death of does. Weight loss, reductions in feed consumption and fetal and embryotoxic effects, including reduced fetal weight and increased incidence in skeletal variations (Infurna etal. 1988)... 

After 181 days, reduction in crown-rump length and increase in fetal skeletal variations (Welsh etal. 1987)... 

Minimal fetoxicity (skeletal variations) was observed in the offspring of rats treated at 100 and 3 54ppm for 6 hours/day on gestation days 6-15 maternal toxicity was also evident at these doses." ... 

Daily oral doses of 4.3, 43, or 432mg/kg to rats on days 6-15 of gestation caused abnormalities in 50%, 93%, and 100% of the animals. Major malformations, including micromelia, vertebral opening, and skull defects, were observed at the highest dose, whereas only skeletal variations occurred at 4.3 mg/kg. Applied to the skin of pregnant rats 1.4ml/kg caused marked maternal toxicity and morphologic abnormalities in the fetuses at... 

Factors that Could Influence the Incidence of Skeletal Variations... 

Interpretation Using Historical Control Data to Understand Supernumerary Ribs, a Common Skeletal Variation... 

Green EL (1962) Quantitative genetics of skeletal variations in the mouse. II. Crosses... 

Developmental Effects. Oral developmental toxicity studies of deca-, octa-, and pentaBDE have shown no evidence of teratogenicity in animals. Gestational exposure to a high (1,000 mg/kg/day) but maternally nontoxic dose of decaBDE was fetotoxic in rats as shown by subcutaneous edema and delayed skull bone ossification. Commercial mixtures of octaBDE caused skeletal ossification variations in rats and rabbits at maternally toxic levels and other indications of fetotoxicity at lower doses. Effects of gestational exposure to octaBDE included minimally increased postimplantation loss in rats at >10 mg/kg/day, increased resorptions in rats at 25 mg/kg/day, and increased skeletal variations in rabbits at 15 mg/kg/day and rats at 50 mg/kg/day. No evidence of fetotoxicity was found in the only available study of pentaBDE in rats at maternally toxic doses < 200 mg/kg/day. No studies are available on developmental effects of PBDEs in humans. Based on the evidence in animals, PBDEs are unlikely to cause developmental toxicity at expected levels of exposure. 

Sprague-Dawley rats were exposed by inhalation to 80,316 or 630 mg/m vinylidene for 7 h per day on days 6-15 of pregnancy. New Zealand rabbits were exposed to 316 or 630 ing/m on days 6-18 of pregnancy (Murray et al., 1979). Toxicity was noted in the dams at 316 mg/m in rats and 630 mg/m in rabbits. Resorptions in dams and skeletal variations in pups were increased in rabbits at 630 mg/m . Skeletal variations were also noted in rats exposed to 316 mg/m and 630 mg/m. ... 

In rats given bromodichloromethane throughout the period of major organogenesis, skeletal variations were observed in the presence of maternal toxicity, but no teratogenic effect was seen (lARC, 1991). 

The triazine herbicides, with the exception of cyanazine, did not produce developmental or reproductive effects at maximally tolerated doses. Cyanazine produced developmental effects in rats and rabbits at the highest doses tested. Effects noted at doses that were toxic to the mothers were cyclopia and diaphragmatic hernia in rabbits and an apparent increase in the incidence of skeletal variations (i.e., anomalies) in rats (USEPA, 1994). 

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