Fused ribs

Fused ribs (two fetuses), 14 ribs (four fetuses), and unfused ossification centers of vertebrae (three... 

Hamster (Golden Syrian) Gd 9 (GO) 5 (increased incidence of cleft palateand fused ribs decreased fetal weight) Ottolenghi et al. 1974 Endrin... 

Developmental Effects. Developmental effects associated with exposure of humans to endrin have not been reported. Prenatal exposure of animals to concentrations of endrin sufficient to cause maternal toxicity has resulted in a statistically significant increase in the incidence of fused ribs, cleft palate, exencephaly, microencephaloceles, and open eyes in hamsters and mice. Effects were not necessarily reproducible between studies. Adverse developmental effects generally have not been observed in rats (Kavlock et al. 1981) except for temporary increase in locomotor activity of pups (Gray et al. 1981) and delayed ossification at doses which resulted in maternal toxicity (Goldenthal 1978a). Developmental effects were found primarily in one species. It is unknown if these effects would occur in humans. 

As mentioned in the introduction, Khera hypothesized that unspeciflc maternal toxicity, per se, was significanfly associated with various fetal adverse effects, including major malformations (5, 6). Based on retrospective analysis of literature data in rodents, hamster, and rabbits he proposed that a number of effects on the offspring occurred merely as a consequence of maternally mediated toxicity. Proposed maternal toxicity-related effects included decreased fetal body weight, external/visceral and skeletal malformations and developmental variations, and resorptions. Examples of the malformations Khera associated with maternal toxicity include exencephaly, open eye, and fused thoracic or lumbar vertebrae in mice, and fused ribs, exencephaly, and eye defects in hamsters, as well as rib, vertebral, and sternebral defects in rats and rabbits. Khera s hypothesis was that such effects were species-specific, and were seldom observed at dosages below those that were maternally toxic. 

Treatment of AB-Jena and DBA mice with 300-400 mg/kg bw 1,1,2,2-tetrachloroethane per day during organogenesis produced embryotoxic effects and a low incidence of malformations (exencephaly, cleft palate, anophthalmia, fused ribs and vertebrae). The effects were related to the dose and period of treatment (lARC, 1979). 

Alteration in offspring weight Cleft palate, fused ribs... 

Mice were administered 1.2-35 mg/kg/day bis(tributyltin)oxide by gavage on days 6-15 of gestation in order to evaluate both prenatal and developmental effects (Davis et al. 1987). Dose- related decreases in fetal weights were observed with a marked effect (i.e., 20% decrease) at the highest dose level. Some skeletal abnormalities, such as fused ribs and ossification centers in the sternebrae and cleft palates, were seen at all dose levels and also in the controls. 

There is apparent potential for extensive remodeling of the skeletal system in the postnatal period extra ribs become vertebral arches and fused ribs and other skeletal malformations disappear prior to... 

The effect of alloxan diabetes on congenital malformations of the foetus has been examined in mice made diabetic prior to conception. Alloxan can induce agnathia, cranioschisis, chaniorrhachischisis, cleft palate, microglossia and fused ribs in a number of animals tested [88]. Development of chick embryos at the early stage is also inhibited by alloxan [89]. Addition of glutathione completely protects the embryos [89]. 

---