摘要:

AbstractTwo maternal intraperitoneal doses of ethanol (2.9 g/kg) administered on gestational day (GD) 8, 12 hours (8d, 12h) and 8d, 16h result in abnormal heart and great vessel development in C57B1/6J mice. Heparinized hearts from GD 9 to 18 conceptuses were dissected to expose the forming or already completed ventricular septum and great vessels and then routinely processed for scanning electron microscopy. As early as GD 9 (12 hours post‐treatment), size deficiency and abnormal external contour of the cardiac tube were notable. By GD 12, deficiencies in the size of the conal and atrioventricular (A‐V) endocardial cushions, as well as abnormal positioning of the A‐V canal, were demonstrable. On GD 13, when the ventricular septum should be complete, a range of deficiencies in the conal tissue was observed. Deficiencies observed were a lack of closure of the ventricular septum in the region of the membranous septum, and lack of septation of the conal portion of the developing heart. These deficiencies persist and have been documented through GD 18. Other abnormalities noted on GD 18 include double‐outlet right ventricle, as well as distal defects of the great vessels including interrupted aortic arch, right aortic arch, and a vascular ring. While these defects are comparable to those seen in the fetal alcohol syndrome, they also overlap considerably with cardiac defects that are characteristic of those in the DiGeorge Syndrome as well as in the CHARGE Association. Recent work by others as well as the fact that acute ethanol exposure in this animal model corresponds to a time of neural crest cell migration has led to the speculation that this cell population is involved in the cardiovascular pathogenesis de

ISSN:0040-3709    

DOI:10.1002/tera.1420330112

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

年代:1986

数据来源: WILEY

摘要:

AbstractThe antischistosomal drug niridazole (NDZ) was found to be teratogenic in a concentration‐dependent manner from 10 to 50 μg/ml (47–233 μM) in rat embryos cultured from day 10 to day 11. A striking malformation consisting of axial asymmetry in which the right side of the embryo showed severe necrosis was the predominant malformation. The drug showed significantly greater dysmorphogenic activity at low (5%) compared to high (20%) oxygen tensions in cultures. Coincubation of embryos and NDZ with an exogenous source of metabolic enzymes and cofactors (NADPH) failed to modify teratogenicity. Inclusion of CO in the culture atmosphere significantly reduced the malformation incidence as did preincubation of the drug with S‐9 and cofactors in medium with low O2tension. Treatment of gravida with NDZ up to and including the maternal‐lethal dose failed to result in observable malformations despite the use of several routes of exposure. These data lead us to hypothesize that rat embryos are capable of performing the reductive activation of NDZ in a fashion analogous to the schistosome but that reductive extraembryonic metabolism may result in teratogenic bioina

ISSN:0040-3709    

DOI:10.1002/tera.1420330113

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

年代:1986

数据来源: WILEY

摘要:

AbstractUsing day 10 rat embryos cultured in vitro, we have shown that methacrylic acid is teratogenic at concentrations ranging from 1.2 to 2.1 mM. At these concentrations, methacrylic acid produced concentration‐dependent decreases in growth parameters, i.e., crown‐rump length, number of somites, and embryo protein content. In addition, methacrylic acid exposure produced malformed embryos characterized primarily by abnormal neurulation. Less frequent abnormalities included hypoplasia of the prosencephalon, edema, malpositioned heart, abnormal flexion, and dilated otic vesicles. Accompanying these abnormalities was an underlying increase in methacrylic acid‐induced cell

ISSN:0040-3709    

DOI:10.1002/tera.1420330114

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

年代:1986

数据来源: WILEY

摘要:

AbstractEffects of caffeine administration to Hamburger‐Hamilton stage 19 chick embryos (3 days of incubation) were investigated. A morphologic study of the effect of caffeine on cardiogenesis showed that caffeine produced total cardiac malformations in the chick in a dose‐related fashion. A maximum frequency of 70.6% was observed with 4.7 mg caffeine. Major malformations included common aorticopulmonary trunk and dextroposition of the aorta accompanied by ventricular septal defect with/without pulmonary stenosis. Qualitative analysis of cinegraphs following exposure of embryos to a single teratogenic dose of caffeine (3.5 mg/egg) produced marked alterations in cardiac function when compared with chick Ringer's controls. Within 3 minutes after exposure to caffeine, dilation of the common ventricle and weak ventricular contractility were observed and persisted for 1 hour. Dose‐response data and microcinematographic observations suggest that caffeine induced cardiac anomalies by a direct toxic effect on the embryo rather than by altering cardiac cell function. Our data also suggest that pathophysiologic changes in cardiac function may play an important role in the pathogenesis of caffeine‐induced cardiac anomalies in the chick

ISSN:0040-3709    

DOI:10.1002/tera.1420330115

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

年代:1986

数据来源: WILEY

ISSN:0040-3709    

DOI:10.1002/tera.1420330116

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

年代:1986

数据来源: WILEY

ISSN:0040-3709    

DOI:10.1002/tera.1420330117

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

年代:1986

数据来源: WILEY

ISSN:0040-3709    

DOI:10.1002/tera.1420330118

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

年代:1986

数据来源: WILEY

ISSN:0040-3709    

DOI:10.1002/tera.1420330101

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

年代:1986

数据来源: WILEY