Skeletal abnormalities

Deformities of the feet were seen by Mier et al. (1960), Schwartz et al. (1963), SoBREViLLA (1964), FoRSYTH et al. (1965), usually as unilateral or bilateral pes cavus. Congenital deformities of the toes (Forsyth et al. 1965) and polydactyly (Friedman et al. 1960) have been described. 

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Monobutyltin Rat MBTC Gestation days 7-17at0, 50, 100, 200, and 400 mg/kg body weight Maternal toxicity thymic atrophy dose-dependent developmental toxicity fetuses with visceral or skeletal abnormalities NOAEL >400 Noda etal. (1992)... 

Pregnant females were sacrificed by carbon dioxide anesthesia on day 21 of gestation the uterine horns were exteriorized through a midline incision in the abdominal wall, and the number and position of live, dead, and resorbed fetuses were noted. After being weighed and sexed, the fetuses were examined for external anomalies the crown-rump length was measured with a vernier caliper. Half of each litter was preserved in Bouin s solution and later examined for soft tissue anomalies (16) the other half was preserved in alcohol, cleared and stained with Alizarin red-S, and examined for skeletal abnormalities (2). 

Histologic and skeletal abnormalities in all BaP-exposed groups depressed mitotic rates in retina and brain in groups exposed to 0.08 pg/L and higher muscle necrosis in all groups exposed to 0.2 pg/L and higher microphthalmia was observed in 17% of BaP-treated trout No DNA adducts detected in liver... 

Hose, J.E., J.B. Hannah, H.W. Puffer, and M.L. Landolt. 1984. Histologic and skeletal abnormalities in bcnzo a]pyrene-treatcd rainbow trout alevins. Arch. Environ. Contam. Toxicol. 13 675-684. 

A minimum of 50% of fetuses are to be examined for visceral alterations and a minimum of 50% for skeletal abnormalities. When a fresh tissue microdissection technique is being used for the visceral examination of rabbit fetuses, all fetuses should be examined for both visceral and skeletal abnormalities. 

Deficiency of vitamin D in childhood produces rickets, a constellation of skeletal abnormalities most strikingly seen as deformities of the legs, but many other developing bones are affected. Muscle weakness is common. 

No developmental effects (soft tissue changes, skeletal abnormalities, inhibition of fetal growth) were noted in the fetuses of female rats exposed to 400 ppm home heating oil no. 2,408.8 ppm fuel oil UNSP, or 401.5 ppm diesel fuel vapor by inhalation during gestation days 6-15 (API 1979c, 1979g Bellies and Mecler 1983). Only one study was located for each fuel oil for these effects. 

Patients with homocystinuria have high levels of homocysteine in blood and urine, and they exhibit skeletal abnormalities such as scoliosis, high arched palate, and generalized osteoporosis in... 

The fetuses are then examined. Full details of fetal examination are provided in other chapters of this book some techniques are performed on fresh fetuses, while other techniques require prior fixation of the fetuses. For rodents, one half of the fetuses in each litter should be examined for soft tissue (visceral) changes the remainder should be examined for skeletal changes. Rabbit fetuses should be examined for both soft tissue and skeletal abnormalities the heads from half of the fetuses should be examined by serial sectioning, with skeletal examination conducted on the remainder of the fetus. 

Table 5 Historical control data for embryo-fetal studies at Ricerca Biosciences with CrI 0F1 mouse incidence of fetal skeletal abnormalities ...

Fetal external, soft tissue, and skeletal abnormalities/alterations should be recorded based on internationally recognized terminology (5). The findings are usually categorized by each testing laboratory based on specified criteria, i.e., malformations, anomalies, and variations. 

Fetal external, soft tissue, and skeletal abnormalities/altera-tions should be noted using internationally recognized terminology (1). Although discussions on classification continue in various working groups, such as the DevTox Project, the findings are... 

It is critical that the examiner is familiar with the normal appearance of skeletal structures including the variants which are typical for the strain or breed of animals that is being used. Therefore, a good historical database of spontaneous abnormalities which occur in the strain of animals used is essential for a proper assessment of skeletal abnormalities observed in a prenatal developmental toxicity study. 

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