摘要:

AbstractTrypan blue and the extra‐toes gene (Xt) in the mouse produce syndromes with many abnormalities in common. Treatment of litters segregating forXtwith trypan blue increases the expressivity of the gene. Gene and teratogen act additively in most cases but interacted in one case. It is suggested that both gene and teratogen act by retardation of developing embryo

ISSN:0040-3709    

DOI:10.1002/tera.1420030202

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

年代:1970

数据来源: WILEY

摘要:

AbstractMale mice heterozygous for the brachy gene (T/+) were mated to Swiss albino females. On day 8 of pregnancy the females were injected with 0.2 ml of 1% trypan blue solution. A control group consisted of Swiss albino females mated to +/+ males and injected with trypan blue on day 8 of gestation. Trypan blue produced taillessness in all heterozygous (T/+) offspring, while +/+ offspring had no major tail abnormalities.

ISSN:0040-3709    

DOI:10.1002/tera.1420030203

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

年代:1970

数据来源: WILEY

摘要:

AbstractThe purpose of this experiment was to examine the influence of methylazoxymethanol acetate (Mam ac) on cell proliferation and regeneration of the external granular layer in the cerebellum of the hamster. Pregnant hamsters were treated with 10 mg/kg/day Mam ac on days 13–15 of gestation and youngsters on the second, third, and fourth or fourth, fifth and sixth postnatal days. In animals treated during intrauterine life and examined on the day of birth a large number of cells in the external granular layer were destroyed, but some seemingly healthy ones always remained. In those permitted to live, surviving cells formed a new external granular layer and by the 20th postnatal day no morphological differences could be detected between the treated and control animals. In animals treated on the second to fourth postnatal days practically all the cells of the external granular layer were destroyed. By the tenth day the Purkinje cells were located throughout the molecular zone. Many of them showed a cytoplasmic cone extending centrally instead of toward the periphery. The internal granular layer contained only a few cells, apparently owing to failure of the normal inflow of neurons from the external granular layer. In animals treated on the fourth to sixth postnatal days most cells in the external granular layer were destroyed. During the following days surviving cells presumably gave rise to a new external granular layer. The cells of this layer failed to migrate centrally. Instead they remained located in the molecular layer where they formed an extra layer of cells, which had the appearance of granule cells. The animals were ataxic, although retinal abnormalities may have been partially responsible for the symptom

ISSN:0040-3709    

DOI:10.1002/tera.1420030204

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

年代:1970

数据来源: WILEY

摘要:

AbstractAnterior and posterior cardia bifida were produced in chick embryos by transplanting tritiated thymidine‐labeled grafts into host embryos, anterior to the anterior end of the streak and medial to the heart‐forming mesoderm, i.e., into areas destined for ventral gut or yolk sac. Anterior cardia bifida resulted when the nonintegrated part of the graft prevented the splanchnic folds from meeting at the midline to form the anterior end of the heart; this anomaly always appeared without corresponding anomalies in the endoderm and ectoderm layers. Posterior cardia bifida resulted when the part of the graft that had not been integrated into the host tissue interfered with the formation of the foregut. The position of the labeled cells in the endocardium, myocardium, mesocardium, endoderm, and yolk sac was determined by radioautography. Although cardia bifida has no known counterparts in the pathological anatomy of human congenital heart disease, study of the condition gives significant insight into the relations of the primary germ lay

ISSN:0040-3709    

DOI:10.1002/tera.1420030205

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

年代:1970

数据来源: WILEY

摘要:

AbstractThe period in which antimouse kidney serum (AKS) was embryolethal in the mouse extended from days 4–15 of pregnancy. The highest sensitivity toward AKS existed at days 10–14.When AKS was localized in the uterus by immunofluorescence the following results were obtained. On day 10 Reichert's membrane, parietal yolk‐sac cells, and endodermal cells of the visceral yolk sac, but not the embryo, showed intense fluorescence. By day 12 Reichert's membrane and the parietal yolk‐sac cells had lost most of their immunofluorescence. The visceral yolk‐sac cells adjacent to the chorioallantoic placenta still stained strongly on day 18 of pregnancy.AKS from which the antiplacental factor(s) were removed retained its embryolethality when injected on day 10. It was localized solely in the visceral yolk sac. Therefore AKS probably caused embryonic death by damaging the yolk‐sac cells.Only during the last days of pregnancy was there any transfer of AKS to

ISSN:0040-3709    

DOI:10.1002/tera.1420030206

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

年代:1970

数据来源: WILEY

摘要:

AbstractRaising the oxygen pressure of the culture chamber to 2 or 3 atmospheres improved the development in static serum of rat embryos explanted at 11.5 days' gestation, but the final stage attained (35–37 somites) was less than that of embryos in circulating serum equilibrated with oxygen at normal pressure (40–45 somites). Hyperbaric oxygen appeared to be of most value for the culture of embryos explanted at 12.5 days' gestation (about 40 somites). These developed well to 50–55 somites in circulating serum in oxygen at two atmospheres pressure, but showed very little development in oxygen at normal pressure. The high oxygen concentrations were harmful to the yolk sac, and it was not possible to extend development in culture beyond 50–55

ISSN:0040-3709    

DOI:10.1002/tera.1420030207

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

年代:1970

数据来源: WILEY

摘要:

AbstractEmbryonic limb cultures from control and riboflavin‐deficient galactoflavin‐treated rats were explanted on gestation day 12.5 and grown in vitro for seven days. The riboflavin‐deficient limb buds failed to grow in riboflavin‐deficient medium but exhibited near‐normal protein synthesis and increase in size in medium supplemented with riboflavin. The growth of control limb buds was not impaired by exposure to deficient medium. The conclusion is that the major mechanism for production of limb defects functions at a local cell level rather than these resulting from physiologic impairment of t

ISSN:0040-3709    

DOI:10.1002/tera.1420030208

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

年代:1970

数据来源: WILEY

摘要:

AbstractThe structures and configurations of three naturally occurring steroidal alkaloid teratogens fromVeratrum californicumthat induce cyclopia in sheep have been elucidated. The probable teratogenic structural requirements were examined in light of known structural and configurational information on active and nonactive compounds. Methods are proposed that will enable elucidation of the precise structural requirements for this teratogenic effect.

ISSN:0040-3709    

DOI:10.1002/tera.1420030209

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

年代:1970

数据来源: WILEY

摘要:

AbstractCyclopamine, the compound responsible for cyclopia in sheep upon maternal ingestion ofVeratrum californicum, produced cyclopia and related cephalic malformations in rabbits when orally administered with CaCO3as a stomach‐acid buffer to prevent acid‐induced conversion to veratramine, a compound devoid of similar teratogenic activity. The insult period was between days 6 and 9 of gestation. Both in vitro and in vivo experiments suggested the conversion of nonbuffered cyclopamine to veratramine under stomach‐acid condi

ISSN:0040-3709    

DOI:10.1002/tera.1420030210

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

年代:1970

数据来源: WILEY

摘要:

AbstractCongenital cerebellar hypoplasia occurred in five calves in two New York State dairy herds in which bovine viral diarrhea‐mucosal disease occurred while the dams were pregnant. Clinical and serological evidence linked the virus infection with the anomalies. The dams of the calves were estimated to have been infected between days 102 and 183 of pregnanc

ISSN:0040-3709    

DOI:10.1002/tera.1420030211

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

年代:1970

数据来源: WILEY