摘要:

AbstractThe craniofacial complex of two neonatal, human, cyclopic specimens was studied in detail. Both specimens exhibited a single ocular opening and one had a prominent proboscis positioned in the midline directly superior to the ocular aperture. No external nasal development was noted in the other specimen. The most remarkable finding was the lack of development of all skeletal derivatives of the ethmoidal cartilage (cribriform plate, perpendicular plate, superior and middle nasal conchae, medial orbital walls, and nasal septal cartilage) in both specimens. Since these bones normally form the medial, lateral, and superior walls of the nasal passage, this cavity was also absent. The two posterior halves of the maxillae were directed superiorly, medially, and with the vomer merged in the midline as a thick mass of bone. As a result the right and left alveolar portions of the maxillae were joined superiorly in the midline. With the absence of the nasal cavity, the right and left medial pterygoid plates merged medially with the palatal and pyramidal processes of the palatine bone to obstruct the junction between the oropharynx and nasopharynx (choanal atresia). The role of the skeletal parts of the ethmoid during maxillofacial growth and development is discussed.

ISSN:0040-3709    

DOI:10.1002/tera.1420260202

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

年代:1982

数据来源: WILEY

摘要:

AbstractReports of parasitic conjoined twins have appeared rarely in the scientific literature and only one study has included a detailed description of the parasitic extremities. We report here two specimens consisting for the most part of normal hosts with ectopic legs attached to the thorax (case 1, thoracoparasitus) or the abdomen (case 2, gastroparasitus). These two specimens are in agreement with several others reported in the literature in having no sign of vertebral columns. These specimens also exhibit a marked decrease in innervation (case 1) or complete absence of somatic nerves (case 2). This finding is in complete contradiction with the idea of the dependence of limb skeletal structure upon peripheral nerves. The hypothesis is presented that this type of parasitic twin may result from duplication of the Wolffian ridge.

ISSN:0040-3709    

DOI:10.1002/tera.1420260203

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

年代:1982

数据来源: WILEY

摘要:

AbstractOne case of median cleft lip with hypotelorism and two cases of cyclopia, all with brains exhibiting alobar holoprosencephaly, were examined by detailed anatomical dissection. The results indicate that the variations of the skull and associated soft structures form a continuum, as do the brain, eye, and face, from the mild to severe end of the syndrome. At the mild end, the bony malformations were primarily limited to the structures derived from the frontonasal prominence, within which the ethmoid bone was the focal point. Malformed soft structures included the muscles of the anterior and posterior neck regions. At the severe end of the spectrum, these structures were more severely malformed, and the sphere of malformations widened to include more peripherally located bones and soft structures such as the mandible, ear ossicles, muscles of mastication, and salivary glands. Possible mechanisms for the generation of the malformations are addressed.

ISSN:0040-3709    

DOI:10.1002/tera.1420260204

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

年代:1982

数据来源: WILEY

摘要:

AbstractChlorambucil, a bifunctional alkylating agent and antitumor drug, is a potent teratogen in rodents and possibly teratogenic in humans. Unlike cyclophosphamide, a related bifunctional alkylating agent, chlorambucil is a direct‐acting cytotoxic agent. However, several studies indicate that the cytotoxic potential of chlorambucil is enhanced by metabolism of the parent compound. Using day‐10 rat embryos cultured in vitro, we have demonstrated that chlorambucil is a direct acting teratogen but that its teratogenicity can be enhanced by the addition of rat liver S‐9 preparations to culture medium containing the durg. Our data also suggest that this enhancement is not related to cytochrome P‐450 monooxygenases. This conclusion is based upon three lines of evidence. First, enhancement occurs under culture conditions which lack cofactors necessary for cytochrome P‐450 monooxygenases. Second, metyrapone, a known inhibitor of cytochrome P‐450, did not abolish the enhancement. Third, induction of cytochrome P‐450 by two specific inducers of monoxygenase activity had no effect on the observed enhancement. We postulate that the observed enhancement of chlorambucil teratogenicity is related to the β‐oxidation of the butyric acid side chain of chlorambucil generating the more cytotoxic (teratogenic) metabolite, phenylacetic acid mustard. Finally, our data indicate that the teratogenic effects elicited by chlorambucil are indistinguishable from those elicited by

ISSN:0040-3709    

DOI:10.1002/tera.1420260205

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

年代:1982

数据来源: WILEY

摘要:

AbstractThe effect of prenatal alcohol exposure on nipple attachment behavior was studied at a number of ages in rat pups whose mothers consumed liquid diets containing 35% or 0% ethanol‐derived calories (EDC) or standard lab chow during pregnancy. In the first experiment, nondeprived pups were tested in groups of three (one from each of the prenatal treatment groups) for nipple attachment to an anesthetized lab chow dam. The second experiment examined the influence of the type of test dam (35% EDC, 0%EDC, or lab chow) on nipple attachment behavior. Finally, experiment three evaluated the possibility that the data from the preceeding experiments were the result of either testing the offspring in triads or alcohol‐induced alterations in maternal behavior. Rat pups from all three groups reared by their biological mothers and a group of 35% EDC offspring fosterd at birth to lab chow surrogate mothers were tested alone rather than in triads. The data from all three experiments clearly indicated an age‐related pattern of nipple attachment behavior; the latency to attach was shortest in 6‐ to 12‐day‐old pups and increased rapidly from 13 to 21 days of age. Prenatal exposure to alcohol significantly increased the latency to attach to the nipple and the rank order of attachment at the younger ages (three to nine days of age) but not in the older animals. Also, the prenatal effect of alcohol was independent of the type of dam to which testing was conducted, the social interaction involved in testing triads, or fostering procedures. These results suggest that prenatal alcohol exposure can interfere with the development of normal suckling behavior, which might influence no

ISSN:0040-3709    

DOI:10.1002/tera.1420260206

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

年代:1982

数据来源: WILEY

摘要:

AbstractN, N1‐bis (dichloracetyl) diamine 1, 8‐octomethylenediamine (WIN 18,446) is an experimental drug which was first investigated as a male contraceptive. It is soluble in lipid solvents but not in water. The administration of 1,200 to 1,600 mg/kg to pregnant rats on the tenth day of gestation produced multiorgan fetal malformations. Smaller doses, 400 to 800 mg/kg, especially if divided over 2 or 3 days, caused perinatal death. Thus, 60 to 100% of offspring of rats given WIN 18,446 on the tenth and 11th days of gestation died at birth or within 4 days (Taleporos et al., 78). The present study investigated such deaths. At doses of 200 mg/kg on day 10 or 50 mg/kg on days 10 and 11,67% of offspring had defective or absent diaphragms, 48% had tracheobronchiomegaly with cystic lungs, and 67% had pleural hemorrhage. At doses of 100 mg/kg given on 1 day or 25 mg/kg each day for 2 days, 50% had tracheobronchiomegaly with cystic lungs and rudimentary acini. At lower doses (18.8 mg/kg × 2 or 12.4 mg/kg × 3), a majority of fetal lungs had rudimentary acini, thick septa, few capillaries, and wide cuffs of perivascular connective tissue. Thus, a chemical given during organogenesis produced dysgenesis of the respiratory apparatus. Varying the dose produced malformed lungs with persistently deficient acini which model such human lung faults as tracheobronchiomegaly (Mournier‐Kuhn Syndrome; Mounier‐Kuhn, '32), bronchiolar dysplasia (Wilson‐Mikity Syndrome), and perinatal death with acinar failure resembling neonatal hyaline membr

ISSN:0040-3709    

DOI:10.1002/tera.1420260207

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

年代:1982

数据来源: WILEY

摘要:

AbstractThe teratogenicity of D‐penicillamine was studied using the Sprague‐Dawley rat. Fetuses from rats fed diets containing 0.83% D‐penicillamine during pregnancy had a high incidence of malformations. Maternal and fetal tissue copper levels were significantly lower in the D‐penicillamine group than in controls, suggesting that the teratogenicity of the drug may be due in part to the induction of copper deficiency by its chelating pro

ISSN:0040-3709    

DOI:10.1002/tera.1420260208

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

年代:1982

数据来源: WILEY

摘要:

AbstractRat embryos were exposed to sodium salicylate in vitro at concentrations comparable to those used to produce terata in vivo. Embryos treated with 400, 600, or 800 μg Na salicylate/ml were compared with embryos treated with an equimolar concentration of NaCl. When compared to growth of the controls, a significant dose‐dependent decrease in growth parameters was observed. The incidence of abnormal embryos characterized by generalized swelling (particularly in the area of the rhombencephalon) was also dose dependent. This study demonstrates the teratogenicity of salicylate in the rat independent of maternal facto

ISSN:0040-3709    

DOI:10.1002/tera.1420260209

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

年代:1982

数据来源: WILEY

摘要:

AbstractThe hypothesis that organophosphate (OP) insecticides reduce the NAD+levels of chick embryos by inhibiting kynurenine formamidase was tested. Fertile chicken eggs at 3 days of incubation were treated with a teratogenic dose of the organophosphate insecticide diazinon (DZN) in the presence or absence of exogenous L‐tryptophan or nicotinamide, or one of the metabolic intermediates (L‐kynurenine, 3‐hydroxyanthranilic acid, quinolinic acid) between tryptophan and NAD+. By day 10 of development, DZN reduced the NAD+content of the hind limbs of the embryos to less than 20% of normal and by day 15 it caused severe type I and type II teratogenic responses. The co‐presence of tryptophan or one of its metabolites served to maintain the NAD+levels of DZN‐treated embryos close to or above normal and significantly alleviated the symptoms of type I teratisms. Tryptophan is virtually as effective as most of its metabolites in suppressing the effects of DZN on the NAD+content and physical development of the embryos. This equivalence does not support the proposition that the inhibition of kynurenine formamidase causes the lowered NAD+levels involved in OP‐induced type I teratogenesis. It is consistent with the concept that the insecticide acts to decrease the availability of tryptophan to

ISSN:0040-3709    

DOI:10.1002/tera.1420260210

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

年代:1982

数据来源: WILEY

摘要:

AbstractThe biochemical differentiation of the brain, lungs, liver, and kidneys of the late gestation rat fetus was examined to characterize the immediate implications of retarded growth on fetal development. Initially, the normative profile of development of the brain (weight, DNA content, and protein content), lungs (weight and surfactant accumulation), liver (weight and glycogen deposition), and kidneys (weight, alkaline phosphatase activity, and protein content) was determined on gestation days 19, 20, 21, and 22 (day 1 = finding of sperm in the vaginal smear). Subsequently, five compounds known to induce fetotoxicity (chlorambucil, methyl salicylate, mirex, nitrofen, and toxaphene) were administered during organogenesis, and the effects on organ differentiation were determined in day 21 fetuses. The effects of fetal growth retardation resulting from exposure to exogenous agents were not equally distributed among the organs studied. The liver and kidney appeared more sensitive to insult by these agents than did the brain and lungs.

ISSN:0040-3709    

DOI:10.1002/tera.1420260211

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

年代:1982

数据来源: WILEY