摘要:

AbstractA case of a ligamentum teres formed from an obliteratedrightumbilical vein is described. It passed to the right branch of the portal vein. The quadrate and left lobes of the liver were not separated by the usual fissure. Very few cases of anomalous umbilical veins or persistent right umbilical veins have been recorded. Of these, several have been recorded only in the umbilical cord, while in others the persistent right umbilical vein has been found intra‐abdominally, in an extrahepatic position, and passing directly to the right atrium or to the inferior vena cava. Its presence is generally associated with severe congenital abnormalities, in contrast with the present case. In view of the high incidence of congenital defects associated with aberrant or accessory umbilical veins, when these are detected either in the umbilical cord or in the abdomen by umbilical phlebography, it is suggested that the patient should be carefully investigated for other congenital abnormalitie

ISSN:0040-3709    

DOI:10.1002/tera.1420370202

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

年代:1988

数据来源: WILEY

摘要:

AbstractAflatoxin B1(AFB1) is a known carcinogen and developmental toxin in various species of mammals, birds, amphibians, and fish. AFB1requires metabolic activation (biotransformation) to the 2,3‐epoxide metabolite for carcinogenicity; however, it is unknown if biotransformation is a prerequisite for AFB1embryotoxicity. Cultured day 10 rat embryos were exposed to AFB1alone and AFB1in the presence of cofactors and hepatic S9 fractions from adult male rats induced with either phenobarbital or 3‐methylcholanthrene. Under these different culture conditions qualitatively similar patterns of malformation were seen in all embryos exposed to AFB1. At culture concentrations of 15 μM or greater, AFB1produced abnormalities in neural tube development in a concentration‐dependent manner. The presence of hepatic S9 fractions had no effect on the ability of AFB1to produce dysmorphogenesis in vitro or on the spectrum of malformations elicited. However, the addition of hepatic S9 fractions did greatly enhance the embryolethality of AFB1. This enhancement was greater with phenobarbital‐ than 3‐methylcholanthrene‐preinduced hepatic S9 fractions. Our results suggest that separate chemical mediators may be responsible for the embryolethal and dysmorphogenic effects of AFB1observed in day 10 rat embryos in vitro. We found that the embryolethality of AFB1, but not the dysmorphogenicity, could be greatly modulated by exogenous biotr

ISSN:0040-3709    

DOI:10.1002/tera.1420370203

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

年代:1988

数据来源: WILEY

摘要:

AbstractSpina bifida occurred in the offspring of golden Syrian hamsters treated on day 8 of gestation, and CD‐1 mice treated on day 9, with 80 mg/kg of retinoic acid. Light microscopic examination of term fetuses demonstrated that myeloschisis was the characteristic form of the defect in mice, whereas myelocystocele was the predominant type of spina bifida induced in the hamster. To investigate the pathogenesis of these defects, a comparative study was undertaken by light microscopy and scanning electron microscopy of the changes occurring in caudal embryonic tissues during the initial 48 hr following maternal treatment. Within 18 hr of exposure, similar effects were observed in both species. These included distortion of the neural folds at the level of the posterior neuropore, vascular damage and hematoma formation, malformation of the notochord, and abnormalities of secondary neurulation. No differences were observed that we thought could account for the apparent variation in the pattern of malformations seen in the term litters. Rather, the dissimilarity may reflect species differences in the position of the posterior neuropore in the neuraxis and in the extent to which secondary neurulation contributes to the development of the lumbosacral cord segment

ISSN:0040-3709    

DOI:10.1002/tera.1420370204

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

年代:1988

数据来源: WILEY

摘要:

AbstractChick embryos were injected on the fifth day of incubation with 75 ngcis‐diamminedichlorplatinum II (cisplatin) and killed at daily intervals. Bilateral microphthalmia appeared in 88% of the surviving embryos; the decrease in eye size was noticeable 2 or 3 days after injection. Coinciding with this, macroscopic, histological, and ultrastructural changes started to appear in the ciliary body: ciliary processes failed to form and the cells in the inner layer of the ciliary epithelium underwent degenerative changes.Changes in the retina appeared somewhat later. Despite the decreased growth rate of the whole eye the neural layer of the retina continued to grow rapidly; as a result, it formed numerous folds and acquired a glandular appearance. In the most severe cases the rapidly growing retina would invade the ciliary region and replace completely the degenerated inner layer of the ciliary epithelium.It has been shown by previous authors that intraocular pressure is a determinant of eye expansion and also that the secretion of water and ions by the ciliary epithelium is important for the maintenance of that intraocular pressure. On this basis, our results are interpreted as indicating that the primary lesion induced by cisplatin was in the ciliary epithelium and that microphthalmia was the consequence of decreased pressure. It is also concluded that the retinal changes were due to the fact that the retina continued to grow despite the lack of expansion of the eye as a whol

ISSN:0040-3709    

DOI:10.1002/tera.1420370205

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

年代:1988

数据来源: WILEY

摘要:

AbstractPregnant C57BL/6cr mice were fed a liquid diet containing 20% of the total calories from either ethanol (E) or sucrose (S) for gestation days 5–17. Adult male and female (six of each from both prenatal‐treatment groups) offspring were tested under various schedules of food reinforcement. The first phase was a test of fixed‐ratio (FR) acquisition in which the required number of responses per unit of reinforcement was increased from 1 to 20 to 100. Prenatal ethanol exposure interacted with other factors to produce an acquisition deficit. The second phase involved responding under extinction (Ext). Under standard Ext procedures there were no prenatal‐ethanol effects; however, when a conditioned reinforcer was superimposed on an FR 5, the E males did not increase their rates as much as the S males. Finally, under a multiple FR 5 DRO 15‐sec (differential‐reinforcement‐of‐other‐behavior) arrangement, prenatal‐ethanol effects were found in each component. For the FR 5 component, prenatal ethanol eliminated the sex differences found in the S subjects. For the DRO 15‐sec component, prenatal ethanol elevated response rates. The results indicate a general decreased efficacy of positive reinforcement in adult mice following pren

ISSN:0040-3709    

DOI:10.1002/tera.1420370206

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

年代:1988

数据来源: WILEY

摘要:

AbstractThe Finnish Register of Congenital Malformations, established in 1963, rendered possible the study of changes in medication during pregnancy. The study consisted of 659 control mothers who had delivered a healthy child during the years 1964–1984. The data of this long‐term follow‐up study were collected by interviews at Maternal Health Care Centers after delivery and were completed by filed antenatal data. The results show a continuous decreasing trend in the usage of analgesics and tranquilizers but not in the usage of antiemetics, antibiotics, and vitamins. We believe that in Finland the publicity aimed at unnecessary medication during pregnancy has affected both the mothers and the health pers

ISSN:0040-3709    

DOI:10.1002/tera.1420370207

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

年代:1988

数据来源: WILEY

摘要:

AbstractVarious doses (0, 1, 5, 10, 15, 20, or 25 mg/kg) of methylazoxymethanol acetate (MAM), a potent alkylating agent, were injected singly into pregnant rats intraperitoneally on day 15 of gestation. Relationships between brain weights and neurochemical changes in the cerebral hemispheres (CHs; cerebral cortex and subjacent white matter, hippocampus, amygdala) and remainder of the brain (BGDM; basal ganglia, diencephalon, and mesencephalon) were examined at 60 days of age in offspring; varying degrees of microencephaly were observed. Dose‐dependent reductions in the weights of CH and BGDM were observed. Reductions in total DNA content positively correlated with decreases in brain weights also observed. Dose‐dependent elevations of noradrenaline (NA) and dopamine (DA) were observed in CH at MAM levels 10 mg/kg and above; dose‐dependent elevations of 5‐hydroxytryptamine (5‐HT) were observed at 15 mg/kg and above; and in BGDM at 20 mg/kg and above dose‐dependent elevations for NA and 5‐HT were observed; dose‐dependent elevations at 15 mg/kg and above were observed for DA. Monoamine concentrations were negatively correlated with brain weights or total DNA contents. NA and DA concentrations increased to the extent of approximately 1.3 times of control at a time when an 18% loss of CH weight was noted in animals treated with 10 mg/kg MAM. It is suggested that the above variables might be appropriately sensitive neurochemical markers for detecting minor developmental anomali

ISSN:0040-3709    

DOI:10.1002/tera.1420370208

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

年代:1988

数据来源: WILEY

摘要:

AbstractA new mutant gene which caused fusion of lung lobes was found in the Wistar rat. The genetic analysis revealed an autosomal recessive inheritance and the mutant gene was namedfused pulmonary lobes(gene symbol: fpl). The right lung of the fpl/fpl homozygotes had fused lobes of varying degrees. The fpl/fpl homozygotes were semilethal at the neonatal stage and had externally visible associated malformations such as malocclusion of incisors, eyelid anomalies, and digit abnormalities in the fore‐ and hindlimbs with different incidences. These traits were considered to be caused by the pleiotropic effects of the fpl gen

ISSN:0040-3709    

DOI:10.1002/tera.1420370209

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

年代:1988

数据来源: WILEY

摘要:

AbstractMurine trisomy 19 (Ts19) can be regarded as a general model of human trisomies. It is the only autosomal trisomy in the mouse that survives the perinatal period. Therefore, it is the only animal model available for postnatal investigations of trisomy‐specific mental retardation. To evaluate the extent of developmental retardation during the late‐embryonic and fetal period of gestation, total body weight development was documented for 60 Ts19‐fetuses and compared with that of 219 euploid in utero‐mates. In addition, a postnatal study on body‐weight development of 77 Ts19‐neonates and 74 euploid littermates was performed starting on day 1 postpartum and continuing until spontaneous death or until day 22. Forty‐seven Ts19‐individuals were further tested in nine behavioural test systems in order to determine their neurophysiological developmental profile. Findings were compared with agedependent morphologic and physiologic parameters. The data obtained in the present study show a significant retardation of organ‐ and body‐weight development in Ts19‐mice starting on day 14 of gestation. Retardation of physiological parameters is progressive and persists throughout the perinatal and postnatal periods. Furthermore, the trisomic individuals showed specific beha

ISSN:0040-3709    

DOI:10.1002/tera.1420370210

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

年代:1988

数据来源: WILEY

ISSN:0040-3709    

DOI:10.1002/tera.1420370211

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

年代:1988

数据来源: WILEY