ISSN:0040-3709    

DOI:10.1002/tera.1420330322

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

年代:1986

数据来源: WILEY

摘要:

AbstractAlthough methanol (MEOH) may assume a significant role as a fuel, which implies wide availability, little is known of its toxicity apart from acute poisoning episodes in human adults. Even less is known about its toxicity in developing organisms. This experiment studied the early behavioral development of rats whose mothers had consumed MEOH during gestation by measuring the responses of suckling (postnatal day 1) and nest‐seeking (postnatal day 10). Primigravida Long‐Evans rats were divided into three groups (N = 10). Two of the groups consumed drinking solutions of 2% MEOH instead of distilled water either on gestational days 15–17 (MEOH 1) or 17–19 (MEOH 2). No maternal toxicity was apparent as measured by weight gain, gestational duration, and daily fluid intake. Daily MEOH consumption averaged 2.5 gm/kg over the 3‐day period in both MEOH groups. Litter size, birth weight, and infant mortality did not differ among the three groups. Postnatal growth and date of eye opening were unaffected. MEOH pups required longer than controls to begin suckling on postnatal day 1. On postnatal day 10, they required more time to locate nesting material from their home cages. These data suggest that prenatal MEOH exposure induces behavioral abnormalities early in life that are unaccompanied by overt

ISSN:0040-3709    

DOI:10.1002/tera.1420330302

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

年代:1986

数据来源: WILEY

摘要:

AbstractPatients with gastroschisis have a paraumbilical defect of the anterior abdominal wall through which bowel loops protrude. These bowel loops are edematous and covered by a fibrous coating. The moment of occurrence of gastroschisis as well as the development of the fibrous coating are unknown. This prompted an investigation of 26 human embryos and fetuses with gastroschisis at various developmental stages (crown‐rump length 25–240 mm) and two stillborn fetuses (gestational age 30 weeks) with gastroschisis, as well as resected material from ten newborns (gestational age 33–40 weeks) operated for gastroschisis. Progressive changes of the serosa were only noted after the 30th week of gestation and consisted of an amniotic fluid peritonitis and progressive fibrosis. The changes are in agreement with experimental data and correlate with changes in the composition of amniotic fluid. The findings prove that gastroschisis is a very early occurrence, while the fibrous coating is a late develo

ISSN:0040-3709    

DOI:10.1002/tera.1420330303

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

年代:1986

数据来源: WILEY

摘要:

AbstractTwo children are reported in whom major limb malformations were identified and whose mothers had consumed large quantities of alcohol in the first trimester of pregnancy. In one there was complete amelia of the upper limbs, while the other had preaxial polydactyly of both hands. These cases, taken together with previously reported instances of major limb anomalies following intrauterine ethanol exposure, as well as animal investigations that have demonstrated virtually identical limb malformations following ethanol administration, suggest that maternal ethanol abuse may be causally related to these limb malformations. We suggest that interruption of blood supply to the developing limb may be caused by ethanol exposure and may result in all of the various limb malformations described.

ISSN:0040-3709    

DOI:10.1002/tera.1420330304

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

年代:1986

数据来源: WILEY

摘要:

AbstractPregant female mice were given ethinyl estradiol on days 11 through 17 of gestation. On day 18 the dams were killed and the male fetuses were examined for testicular differentiation. Three of 12 males from dams treated with the highest dose of ethinyl estradiol showed cryptorchild testes with uterine tubes. Light and electron microscopic evaluation of the testes, both cryptorchid and normal, demonstrated foci of hyperplasia of Leydig cells showing cytoplasmic and nuclear pleomorphism, increase in lipid droplets, and decrease in smooth endoplasmic reticulum and ribosomes when compared to testes from control fetal mice. Morphometric determinations of the testes indicated that the number of Leydig cells in a unit area (mm2) in the interstitial tissue showed a dose‐response relationship to ethinyl estradiol in the normal testes. The number of Leydig cells in the testes exposed to the highest dose of estrogen showed a significant difference between cryptorchid and normal testes: the former had fewer Leydig cells than the latter. These morphological observations indicate that hyperplasia of Leydig cells of fetal mouse testis at term can be induced by transplacental treatment with ethinyl estradiol and suggest that a malignant transformation into a Leydig cell tumor is possibl

ISSN:0040-3709    

DOI:10.1002/tera.1420330305

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

年代:1986

数据来源: WILEY

摘要:

AbstractA retrospective cohort study on the effect of the suspected teratogenic pesticide N, N′ ‐methylene‐bis‐(2‐amino‐1,3,4‐thiadiazole) (MATDA) on outcomes of pregnancy was conducted. The exposed group (6,173 pregnancies) was composed of childbearing women who, during their gestation, consumed rice harvested from a field where MATDA had been applied. The control I group (10,145) came from an adjacent county where MATDA had never been used; the control II group (3,326) consisted of women who had been pregnant previous to the introduction of this pesticide in the same region as the exposed group. The validity of the survey was verified by comparability and data checking studies. After adjustment for the calendar year, maternal age, and pregnancy order, no significant differences were found in rates of spontaneous abortion, fetal death and stillbirth, birth defects, as well as in sex ratio and birth weight between the study groups. The same result was found in the comparison of individual categories of malformation. The rates of the birth defects were 23.84, 21.49, and 22.78 per 1,000 live births for the exposed, internal, and external control groups, respectively. No dose‐response relationship was revealed. The results were consistent with previous reports and indicated the difference between animal experiments and human exposures. Although MATDA is teratogenic in animals, it is clear that the pesticide does not adversely effect outcomes of pregnancy in humans as cu

ISSN:0040-3709    

DOI:10.1002/tera.1420330306

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

年代:1986

数据来源: WILEY

摘要:

AbstractIn Newfoundland, babies with anencephaly are conceived most often in January, and those with spina bifida in August. These and previous observations suggest that (1) seasonal fluctuations are greatest when the population frequency is neither very high nor very low, and that (2) the peak season for conception of anencephalic babies may occur in any season except August‐November in various populations, whereas for spina bifida seasonal peaks are confined almost exclusively to May–Aug

ISSN:0040-3709    

DOI:10.1002/tera.1420330307

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

年代:1986

数据来源: WILEY

摘要:

AbstractAround 60% of the mouse mutants called curly‐tail, have tail aberrations in the form of a coil or a kink, with or without lumbosacral spina bifida, and rarely, exencephaly. These neural tube defects (NTD) are the result of an incompletely penetrant recessive gene. A single injection of various doses (1–6 mg/kg) of the DNA inhibitor mitomycin C was given to pregnant curlytail mice on day 7, 8, or 9 of gestation, and its effect on the NTD of the embryos was noted. No dose used was lethal to the embryo. When given on day 7 or day 8, mitomycin C markedly increased the number of exencephalics, and additionally, on day 8, it reduced the number of posterior abnormalities. However, on day 9, no exencephaly was produced, and there was a drastic reduction in the number of tail and spinal defects, the overall incidence of NTD being as low as 15% with 2 mg/kg. A twofold effect of mitomycin C on the curly‐tail embryos was thus observed–according to the time in development it was administered, firstly, a teratogenic effect, and later, a “remedial” or preven

ISSN:0040-3709    

DOI:10.1002/tera.1420330308

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

年代:1986

数据来源: WILEY

摘要:

AbstractEmbyos removed at 11.5 days gestation from pregnant rats allowed a zinc‐deficient diet from the time of mating showed a high frequency of malformations of all organ systems. There were, however, large differences between litters of individual dams. Comparison of the daily food intake of zinc‐deficient dams with the appearance of the embryos suggested that fluctuations in the maternal serum zinc levels induced by feeding or fasting influenced the availability of zinc to the embryos. By cyclically feeding zinc‐deficient dams to a predetermined schedule, low maternal serum zinc levels were induced at selected stages of development. This was accompanied by specific malformations of the organs developing at that

ISSN:0040-3709    

DOI:10.1002/tera.1420330309

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

年代:1986

数据来源: WILEY

摘要:

AbstractCaffeine at high doses is a known rodent teratogen and induces limb malformations along with cleft palate in various strains of rats and mice. Fujii and Nishimura ('74) postulated that caffeine was teratogenic by virtue of catecholamine release from maternal or embryonic tissue. We tested this hypothesis by surgically removing the maternal adrenal gland on day 6 of pregnancy and then administering 175 mg/kg of caffeine intraperitoneally at 1600 h day 11 and 900 h day 12. The teratogenic effects of caffeine in adrenal‐ectomized versus nonadrenalectomized AKR mice were assessed in day 18 fetuses. Thirty percent of the surviving offspring were malformed in caffeinetreated, nonadrenalectomized dams compared to 7% of the offspring from adrenalectomized dams. Therefore we believe caffeine teratogenesis is initiated by release of catecholamines from the maternal adrenal glan

ISSN:0040-3709    

DOI:10.1002/tera.1420330310

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

年代:1986

数据来源: WILEY