摘要:

AbstractA detailed anatomopathologic study of the various developmental malformations encountered in a set of female thoracopagus twins is presented. Special emphasis has been devoted to the analysis and description of the complex cardiovascular abnormalities associated with the conjoined heart and liver of this set of twins. The heart was conjoined with two sets of great arteries. The great arteries of one twin were d‐malposed and originated from a single right ventricle; a normally placed aorta originated from a single left ventricle and the hypoplastic pulmonary trunk originated from a rudimentary outlet chamber of the other twin. One twin had two atria with the systemic veins returning to the right one and an anomalous pulmonary venous return terminating in the ductus venous of her liver. The other twin had a single right atrium plus an accessory atrial chamber to which both the pulmonary and the systemic veins returned. There were two umbilical arteries originating from the internal iliac arteries of one twin and two umbilical veins which fused into one as they entered into the ductus venosus of the other twin. The cardiovascular abnormalities of our case have been compared with those encountered in 25 well‐documented cases of thoracopagus twins previously reported in the literature. It was concluded that the majority of thoracopagus twins (approximately 75%) had conjoined heart with associated cardiovascular abnormalities making them unsuitable for surgical separation even at the cost of the life of one of them. In addition, an embryological interpretation concerning the possible origin of the cardiovascular abnormalities of our case is presented and discus

ISSN:0040-3709    

DOI:10.1002/tera.1420230113

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

年代:1981

数据来源: WILEY

摘要:

AbstractC57B1 mice were given orally one, two, or three doses of retinyl palmitate or retinoic acid on day 11, 12, 13, or 14 of pregnancy to determine 1) if it was possible to produce cleft palate at any time during palatal development of the mouse embryo, and 2) the maternal and fetal levels of vitamin A associated with the production of clefts. Whereas a single dose of either substance was sufficient to cause clefts on day 11 or day 12, three doses at 3‐hour intervals were necessary to cause clefts on day 14. Most of these clefts were incomplete. Measurement of vitamin A levels in maternal serum and fetuses of dams after administration of retinyl palmitate or retinoic acid on day 11 and day 14 of pregnancy showed that transplacental passage of retinyl palmitate, retinol, and retinoic acid had taken place. Analysis of fetal serum on day 14 showed increase in levels of retinyl palmitate, retinol, and retinoic acid after dosing with retinyl palmitate, and in retinoic acid alone after dosing with retinoic acid. In both cases peak levels were observed within 3 hours. Our findings suggest that the effect of vitamin A on the developing mouse palate is direct, occuring soon after its administration, and that duration of exposure is as important as its concentration in vivo. The apparent change in sensitivity of mouse palate between day 11 and day 14 of pregnancy is discusse

ISSN:0040-3709    

DOI:10.1002/tera.1420230114

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

年代:1981

数据来源: WILEY

摘要:

AbstractA fixed‐exposure culture technique is described using palatal shelves removed from mouse fetuses on day 14 of pregnancy. In this technique growth is eliminated as a possible variable. The addition of retinyl palmitate, retinol, or retinoic acid to culture medium at concentrations similar to those found associated with cleft palates produced in vivo after dosing dams with vitamin A on day 14 prevented fusion of explanted shelves in vitro after a 24‐hour exposure period. Retinoic acid prevented fusion of explants after as little as 4 hours exposure. Retinoic acid was more active in vitro than retinol, which was itself eight to ten times more active than retinyl palmitate. An explanation of the effect of vitamin A on the fusing mouse palate is given based on altered glycoprotein synthe

ISSN:0040-3709    

DOI:10.1002/tera.1420230115

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

年代:1981

数据来源: WILEY

ISSN:0040-3709    

DOI:10.1002/tera.1420230117

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

年代:1981

数据来源: WILEY

ISSN:0040-3709    

DOI:10.1002/tera.1420230118

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

年代:1981

数据来源: WILEY

ISSN:0040-3709    

DOI:10.1002/tera.1420230119

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

年代:1981

数据来源: WILEY

ISSN:0040-3709    

DOI:10.1002/tera.1420230120

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

年代:1981

数据来源: WILEY

ISSN:0040-3709    

DOI:10.1002/tera.1420230102

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

年代:1981

数据来源: WILEY