摘要:

AbstractCleft lip and palate (CLP) and open eyelid (OL) occur spontaneously in rather high frequencies in A/JKt mice, but vary greatly in their degree, laterality, and sex distribution. CLP occurs significantly more often in females, and OL even more often in males, than in the opposite sex. The female preponderance for CLP was largely if not entirely due to the increased rate of occurrence of left and incomplete forms of the defect, and to the excess in females heavier than the female median weight; whereas the male preponderance for OL could not be explained by any clear or major disparities of these sorts. CLP and OL occurred together more often than expected in individuals, but not in litters. There was no relation between the rate of defects in successive litters of the same female; nor was a relation detected between extent and severity of defect.

ISSN:0040-3709    

DOI:10.1002/tera.1420190102

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1979

数据来源: WILEY

摘要:

AbstractTwo infants whose malformations fulfilled the clinical, radiographic and pathologic criteria of campomelic syndrome, were additionally found to have features suggestive of intrauterine viral infection. The presence of hydrocephalus and hydromyelia in both neonates and focal proliferative villitis in the placenta of one suggests that intrauterine viral infection may play a role in the pathogenesis of campomelic syndrome.

ISSN:0040-3709    

DOI:10.1002/tera.1420190103

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1979

数据来源: WILEY

摘要:

AbstractConcanavalin A (con A) is teratogenic to rabbit embryos during gestational days 12–15. Intracoelomic injections of 40 μl con A solution (4 μg/μl) were performed on rabbit embryos during gestational days 10–15. Control embryos received either 40 μl of saline, sham injection or no treatment. Con A caused increased fetal resorptions on days 10 and 11, but malformation levels did not differ from controls. On days 12–15, con A produced craniofacial, trunk and limb anomalies. The highest percentage of malformations occurred on day 14. The defects were classified into four groups: (1) malformations of limbs including paw and digital dysplasias as well as fusions of the limbs to the head or body wall; (2) “closure” defects such as umbilical hernia, encephalocoele, exencephaly or ectopia cordis; (3) “contracture” defects such as club paws, extended knees, or clenched digits, which exhibited normal osseous and cartilaginous skeletons; and (4) miscellaneous, non‐specific anomalies including fused or dysplastic sternebrae or ribs. Histologic analysis of selected 12‐day embryos 4 to 18 hours post‐injection was performed to ascertain potential sites of teratogenic action. At 12 hours ectodermal necrosis was observed in the limb buds adjacent to the apical ectodermal ridge. By 18 hours, the ectoderm had eroded, exposing the basal lamina to the amniotic fluid. Focal areas of mesenchymal necrosis were observed in association with the ectodermal erosion. The potential roles of amniocentesis and limb bud repair in the genesis of the malf

ISSN:0040-3709    

DOI:10.1002/tera.1420190104

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1979

数据来源: WILEY

摘要:

AbstractA new hereditary tail anomaly (gene symbolTal) in rats was found in the course of teratological studies with trypan blue. The characteristic feature of the tail anomaly was a short and kinked tail. The genetic analysis indicated that the tail anomaly was caused by an autosomal dominant gene and the homozygotes were lethal in the prenatal stage. The first sign of degeneration in the homozygous embryo appeared in the late egg cylinder stage. The phenotype of this mutant is similar to that ofT‐locus mutants in mic

ISSN:0040-3709    

DOI:10.1002/tera.1420190105

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1979

数据来源: WILEY

摘要:

AbstractEmbryomortality and teratogenesis provoked by inhibitors of cholesterol synthesis are well demonstrated. Teratogenic action is particularly reflected by holoprosencephalies, but also by uro genital abnormalities. A hypercholesterolemia‐provoking diet has been shown to be completely effective for preventing holoprosencephaly, but only partially so for preventing the urogenital malformations and fetal mortality. It is thus possible that the two types of abnormalities are governed by different mechanisms. In addition, the diet itself, whose hypercholesterolemic effect is considerable, has certain disadvantages. It seems to have a certain effect on fetal mortality and could be responsible for several uro‐genital malformations. This deserves further st

ISSN:0040-3709    

DOI:10.1002/tera.1420190106

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1979

数据来源: WILEY

摘要:

AbstractCholesterol synthesis inhibitors administered to rats caused more or less complete forms of the holoprosencéphalic syndrome, consisting of severe abnormalities of the brain, sense organs and pituitary. The absence of the pituitary was also observed in fetuses without externally visible cephalic abnormalities.These observations suggest that the isolated absence of the pituitary is the lesser form of the holoprosencephalic syndrome.This interpretation is also valid for cases of isolated absence of the pituitary observed in humans

ISSN:0040-3709    

DOI:10.1002/tera.1420190107

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1979

数据来源: WILEY

摘要:

AbstractPrevious studies have reported indirect evidence for the mediation of folate antagonism in the induction of malformations by diphenylhydantoin. We have demonstrated that a teratogenic regimen of folate‐deficiency and antagonism using 9‐methyl PGA in the rat produces significantly decreased rates of oxygen consumption in the maldeveloping embryos. The present study reports similar reductions in oxygen uptake by mouse embryos from mothers treated with teratogenic doses of diphenylhydantoin, and documents a significant depression of the actual folate levels in such embryos. The differences are less significant with lower doses of diphenylhydantoin, and do not occur with a nonteratogenic d

ISSN:0040-3709    

DOI:10.1002/tera.1420190108

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1979

数据来源: WILEY

摘要:

AbstractThree insecticides, carbaryl, malathion and parathion were tested for teratogenic effects in developing medaka eggs. The concentrations of insecticides ranged from 0.5 to 40.0 parts per million (ppm). The insecticides, dissolved in acetone, were added to dishes containing 10 newly fertilized eggs and 10 ml of embryo rearing solution. Circulatory anomalies which resulted in‐cluded defects in heart morphology, pericardial edema, irregular heart beat, blood clots and oscillating blood in the heart. The ED50(effective dose) for cabaryl was 2.5 ppm; malathion, 10.0 ppm and parathion, 2.0 ppm.Limited exposure experiments were undertaken to determine possible sensitivity periods during development. These experiments, using 10 ppm carbaryl were initiated on days 0–7. Exposure lasted 24 to 96 hours. No periods of sensitivity were observed in these experiments. In a slightly varied experiment, eggs developed normally for 0–5 days, but were not removed from the insecticide once exposed. These results showed that carbaryl could cause circulatory abnormalities in 92% of the embryos which had completed cardiac morphogenesis before exposure.Combinations of malathion and carbaryl were administered to determine possible interactions. Twenty‐five different combinations ranging from 0.0 to 25.0 ppm were employed. At low concentrations, combinations had slightly greater than additive effects. At higher concentrations additive and antagonistic effects were observed.The above experiments show that (a) these insecticides are teratogenic, (b) carbaryl at 10 ppm does not disrupt developmental events but rather affects‐cell physiology and (c) combinations of some insecticides have an additi

ISSN:0040-3709    

DOI:10.1002/tera.1420190109

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1979

数据来源: WILEY

摘要:

AbstractThe single treatment of pregnant mice on day 12 post conception with 5‐azacytidine (AzaCr), followed by a single irradiation dose of 200 rad two hours later, is exclusively neurotoxic to the fetus, as shown by a severe hyoplasia of the parieto‐occipital regions of the telencephalon. This effect is explicable by the specific function of the mitotic cell population for the integrity of the cortex wall. Combining these two hazards in the reverse manner, i.e., irradiation followed by AzaCr, resulted in no general hypoplastic effect in the forebrain and only caused a depletion of cells in the marginal cortex. This indicates a significantly diminished AzaCr sensitivity of fetal cortical cells subsequent to X‐irradiation. In addition, rosette‐like cell clustering in the cortex of all X‐irradiated animals occurs to a similar degree, irrespective of any additional AzaCr‐treatment. The only conformity between these different schedules is that a great portion of the surviving cells is most likely in the DNA synthesizing phase at the time of irradiation. It is therefore concluded that rosette formation starts perferentially from cells injured during

ISSN:0040-3709    

DOI:10.1002/tera.1420190110

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1979

数据来源: WILEY

摘要:

AbstractDosages of methotrexate of roughly comparable embryotoxicity were determined to be 0.3 mg/kg on gestation day 10 in rats and 3.0 mg/kg/d on days 29 through 32 of gestation in rhesus monkeys. These times represented similar periods in development. This regimen in rats was moderately embryolethal, slightly teratogenic, and caused some intrauterine growth retardation; in monkeys it was mildly embryolethal, not teratogenic, and caused only transitory growth retardation.Methotrexate was largely cleared from maternal plasma of both species within 8 hours, and in spite of a higher administered dose and initial concentration in monkey, the rate of fall was faster than in rat. The fraction of total drug concentration remaining unbound in plasma was approximately 30‐40% during the first 4 hours after treatment in both species. Embryo concentrations, however, were strikingly different during the first 8 hours, ranging between 108 and 209 ng/g in monkey but between 3.4 and 7.7 ng/g in rat. A slow rate of fall in embryo concentrations in both species was estimated to be inversely proportioned to the rate of growth of embryos, which was in accord with the fact that the absolute amount per embryo was little changed in 24 hours.Thus, the degree and type of embryotoxicity was not closely correlated with the level or duration of concentration in the embryos: a small maternal dosage in rat produced moderate embryotoxicity and very low embryo concentrations; a large maternal dosage in monkey produced slight embryotoxicity despite high embryo concentration

ISSN:0040-3709    

DOI:10.1002/tera.1420190111

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1979

数据来源: WILEY