摘要:

AbstractAchondroplasia was induced in chicken embryos by in ovo application of 0.6 mg/egg thallium sulfate. The critical (sensitive) period for production of achondroplasia began on day 5 of incubation and ended at the start of HH stage 35 (8.5 days). The end of the critical period was accurately timed and found to be 205–207 hours of incubation and to coincide with a 66% decrease in growth rate of the embryos. Treatment resulted in reduced tibial growth one day later, tibial angulation two clays later, and chondrocytic necrosis four days later. The last was therefore not the cause of the angulation. Tibias were taken from thallium‐treated and control donor embryos of various ages and grafted to the chorioallantoic membranes of treated and control host embryos of various ages during and outside the critical period and achondroplastic changes induced in grafted tibias exposed to thallium while on the chorioallantoic membrane. The critical period was extended into day 10 of incubation in such grafted tibias. Tibias maintained for seven days in organ culture were achondroplastic if pretreated with thallium at seven or eight days of incubation but not at ten days. Exposure of as little as 0.5 hour was sufficient to elicit micromelia when the tibias were grafted or organ cultured. Thallium therefore rapidly binds to skeletal tissues during a critical period of embryonic development but this critical period may be extended when tibias are removed from the emb

ISSN:0040-3709    

DOI:10.1002/tera.1420150102

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

年代:1977

数据来源: WILEY

摘要:

AbstractFemale rhesus monkeys and marmosets were fed a diet containing blighted potatoes (Phytophthora infestans) at a level of 10 g/kg per day for at least two weeks prior to breeding and six weeks following conception in order to gain additional information on the association of blighted potatoes and the development of anencephaly and spina bifida in primate species. There was an absence of either of these neural‐tube defects in 32 rhesus and 14 marmoset infants whose mothers had received a blighted potato diet. In addition there were no cranial osseous defects. There were, however, two rhesus monkey infants with internal hydrocephalus whose mothers had consumed blighted potatoe

ISSN:0040-3709    

DOI:10.1002/tera.1420150103

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

年代:1977

数据来源: WILEY

摘要:

AbstractMedroxyprogesterone acetate (MPA) was given once daily sc at 0.1–3,000 mg/kg/day for 3, 6, or 9 consecutive days during gestation days 7 to 15 to GDI and A/J mice, and New Zealand (NZ) and Dutch Belted (DB) rabbits, and during days 8 to 16 to CD rats. Malformations attributable to MPA did not occur in fetuses of mice or rats exposed to the largest dosage tested. However, 1, 3, or 10 mg/kg on days 13 to 15 to NZ rabbits resulted in 6, 28, and 42% cleft palate, respectively. Comparable cleft palate frequencies were seen in DB offsprin

ISSN:0040-3709    

DOI:10.1002/tera.1420150104

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

年代:1977

数据来源: WILEY

摘要:

AbstractPyridine‐2‐aldoxime methiodide and pyridine‐2‐aldoxime methyl methane sulfonate (P2S), used as supplements to carbachol or neostigmine, greatly lowered the incidence in chicken embryos of vertebral defects and muscular hypoplasia. With 4‐pyridine aldoxime the effect of the teratogens was less reduced. Supplementation of carbachol or neostigmine with either ambenonium or toxogonin lessened the occurrence of muscular hypoplasia, but did little, if anything, to prevent malformation of the neck vertebrae. In tests with physostigmine P2S as supplement reduced or prevented cervical defects, but failed to protect the nicotinamide‐sensitive parts of

ISSN:0040-3709    

DOI:10.1002/tera.1420150105

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

年代:1977

数据来源: WILEY

摘要:

AbstractTwo cases are reported of the association of a group of abnormalities defined as the Vater syndrome, together with a hypothesis, based on the presence of normal cell death during embryogenesis, on how they occur together so frequently. Althouh the medhanism of normal cell death is unknown, adjacent cells are probably affected sublethaly and subsequently recover. A teratogenic situation introduced simultaneously with the occurrence of normal cell death may further diminish the viability of those adjacent cells, causing increase in the necorotic zone and loss of both normal tissue and growth potential.

ISSN:0040-3709    

DOI:10.1002/tera.1420150106

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

年代:1977

数据来源: WILEY

摘要:

AbstractPaired organ cultures of metacarpal, metatarsal, and long bones of previable human embryos, of 7 to 12 weeks' gestation, and tibias of 17‐day rat fetuses were inoculated with live or ultraviolet‐inactivated rubella virus or control fluids and the growth of the bones was measured by increase in wet weight. In several cultures the ability of the human bones to incorporate35S, a measure of rate of mucopolysaccharide synthesis, was tested. Growth of human and rat bones was retarded in cultures inoculated with live virus but not in cultures inoculated with inactivated virus or control fluids. Mean35S uptake was increased by approximately 25% in virus‐inoculated cultures of bones of 9‐ to 12‐week human embryos. No histological abnormalities were seen. These findings suggest that (1) defective bone growth in congenital rubella is a direct effect of viral infection of bone, (2) a disorder of mucopolysaccharide syntheses may contribute to the osseous lesions that occur in this disease, and (3) organ cultures of human embryonic and fetal rat bones may serve as convenient models for studying the pathogenesis of this virus‐induced congenital

ISSN:0040-3709    

DOI:10.1002/tera.1420150107

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

年代:1977

数据来源: WILEY

摘要:

AbstractA prospective survey was carried out by the French National Institute of Health and Medical Research (INSERM) in 12 University hospitals in Paris and included 12,764 women; 189 gave birth to babies with unequivocal, nonchromosomally based, malformations. There was a significant excess of malformed infants when women had taken phenothiazines during the first three months after the last menstrual period. This association did not seem due to chance or to bias and coud not be explained by the influence of the outcome of previous pregnancies. These data are to be added to results of recent surveys showing a significant increase of malformations in children exposed in utero to anticonvulsants, carbamates, benzodiazepines, tricyclic antidepressants, and amphetamines.

ISSN:0040-3709    

DOI:10.1002/tera.1420150108

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

年代:1977

数据来源: WILEY

摘要:

AbstractDaily oral administration of 10 mg/kg retinoic acid to pregnant Macaca nemestrina monkeys on days 20 to 44 resulted in a high frequency of craniofacial and musculoskeletal malformations. Craniofacial defects including cleft palate and anomalies of the pinna were common as were ectrodactyly, kyphosis, and muscular‐joint contractures. Transposition of the great vessels of the heart occurred in one animal and polycystic kidney and associated urogenital anomalies in another. Shorter treatment periods with similar or higher dosages were not teratogenic and were less fetocidal. Although only relatively long treatment courses were teratogenic, the defects that resulted were morphologically similar to those induced with retinoic acid or other vitamin A compounds in other animal order

ISSN:0040-3709    

DOI:10.1002/tera.1420150109

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

年代:1977

数据来源: WILEY

摘要:

AbstractThe prenatal effects of methotrexate (MTX) in rats and rabbits were assessed. It was found highly embryotoxic in postimplantation rat embryos; 0.3 mg/kg ip or less caused nearly total embryolethality with slight teratogenicity. Rabbit embryos were far more resistant to small doses of MTX than rats, but 19.2 mg/kg iv, when given during days 10 to 15 of gestation, produced little death and a constant spectrum of malformation in a high percentage of offspring. Cleft palate, skull defects, and severe fore‐and hindlimb dysplasias, occurred with a high degree of regularity and were strongly dose and developmental‐stage speci

ISSN:0040-3709    

DOI:10.1002/tera.1420150110

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

年代:1977

数据来源: WILEY

摘要:

AbstractThe effect of Azodrin on avian development was studied using a bobwhite quail line and two chicken lines—a single comb White Leghorn (SCWL) and an Australorp line. The bobwhite quail embryos did not respond to injections of Azodrin until stages 22 to 23 (6 days of incubation); the SCWL embryos, not until stage 18 (3 days of incubation) with increasing susceptibility through stage 20. The threshold concentration, at stage 19, for the SCWL was 0.4 mg/kg, for the Australorp, less. Within one hour of treatment stage‐20 embryo shape was altered. There was, however, no immediate response from embryos treated earlier. The effect appeared as a reduced growth rate in the cervical flexure, and may be mediated by interference with the normal energy balance. The response, once initiated, was continuous through 10 days of incubat

ISSN:0040-3709    

DOI:10.1002/tera.1420150111

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

年代:1977

数据来源: WILEY