Teratology

No abstract text is available yet for this article.

No abstract text is available yet for this article.

BACKGROUND: Many teratogens induce oxidative stress, altering redox status and redox signaling; this has led to the suggestion that developmental toxicants act by disturbing redox status. The goal of these studies was to determine the consequences of altering glutathione homeostasis during organogenesis on embryo development, total DNA methylation, and activator protein-1 (AP-1) DNA binding activity and gene expression. METHODS: Gestational day 10.5 rat embryos were cultured in vitro for up to 44 hour in the presence of L-buthionine-S,R-sulfoximine (BSO), an irreversible inhibitor of gamma-glutamyl-cysteine synthetase, the rate limiting step in glutathione biosynthesis...

BACKGROUND: This study was undertaken to evaluate some possible risk factors for hypospadias with special regard to parity, subfertility and maternal smoking. METHODS: With the use of the Swedish health registries, 3,262 infants with a diagnosis of hypospadias were identified among 1,413,811 infants born in 1983-96 with prospectively collected smoking exposure during pregnancy. Odds ratios (OR) and 95% confidence intervals (CI) were calculated after adjustment for various possible confounders...

BACKGROUND: Advances in quantitative analysis and molecular genotyping have provided unprecedented opportunities to add biological sampling and genetic information to epidemiologic studies. The purpose of this article is to describe the incorporation of DNA sample collection into the National Birth Defects Prevention Study (NBDPS), an ongoing case-control study in an eight-state consortium with a primary goal to identify risk factors for birth defects. METHODS: Babies with birth defects are identified through birth defects surveillance systems in the eight participating centers...

BACKGROUND: The mycotoxin fumonisin B1 (FB1) inhibits sphingolipid synthesis, blocks folate transport, and has been associated with increased incidences of cancer and neural tube defects. Results from reproductive studies in animal models in vivo and in vitro have demonstrated toxicity in some cases, but no specific terata after fumonisin exposure. No information is available about folic acid's potential to protect against this toxicity. METHODS: Neurulating mouse embryos were exposed to fumonisin or folinic acid in whole embryo culture and assessed for effects on growth and development...

BACKGROUND: Diabetic pregnancy displays increased incidence of congenital malformations and elevated levels of lipid peroxides in the offspring. The aim of the present work was to study if exogenous administration of one lipid peroxide, the isoprostane 8-iso-PGF(2alpha), is teratogenic per se in rat embryos in vitro, and if such teratological effects may be diminished by supplementation of an antioxidative agent, i.e., N-acetylcysteine or superoxide dismutase, to the culture medium. METHODS: Day-9 embryos were cultured in vitro for 48 hr and subjected to 8-iso-PGF(2alpha) with and without N-acetylcysteine or superoxide dismutase...

BACKGROUND: The antiepileptic valproic acid (VPA) is a teratogen whose embryopathic mechanism(s) remain uncertain. Elucidating potential cellular and molecular effects of VPA is complicated by systemic application paradigms. We developed an in ovo model to reproduce the teratogenic effects of VPA and a localized VPA application procedure to determine whether VPA can selectively effect abnormal development in one region of the embryo. METHODS: VPA was applied topically to chicken embryos in ovo at different embryonic stages...

BACKGROUND: Previous studies of the tracheoesophageal sulcus and the sulci of the developing heart have suggested that the catenoidal or saddle-shaped configuration of the sulcus had mechanical properties that were important to developmental processes by causing regional growth limitation. We examined the development of the human perineal region to determine if a similar configuration exists in relation to the urorectal septum. We wished to re-examine the controversial issue of the role of the urorectal sulcus in the partitioning of the cloaca...

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No abstract text is available yet for this article.

BACKGROUND: Changes in the distal phalanges of the fingers, including coned epiphyses and hypoplasia of the phalanges, are recognized teratogenic effects of the anticonvulsant drugs phenytoin and phenobarbital. We hypothesized that the frequency of these changes would also be increased in the toes of children exposed to these drugs in comparison to unexposed children. METHODS: We report on the findings in an analysis of radiographs of the feet of 63 children exposed in utero to either phenytoin alone, phenobarbital alone or both drugs and 56 unexposed comparison children...

BACKGROUND: The aim of the study was to evaluate congenital malformations and functional anomalies in the offspring of Swedish parents with thalidomide embryopathy (TE). METHODS: Sixty-four children (29 girls, 35 boys) with ages ranging from 0-18 years, born to 34 Swedish parents (14 women, 20 men) with TE, were studied. Data on malformations and dysfunction were collected from medical records at maternity and child healthcare units, delivery units, hospitals, outpatient clinics and schools...

BACKGROUND: Anencephaly has been associated frequently with intrauterine growth retardation (IUGR), consistently with adrenal hypoplasia, and occasionally with an enlarged thymus. Few studies have analyzed the relationship between gestational age (GA), IUGR, associated anomalies and thymomegaly in anencephaly. The aims of our study were to evaluate this relationship and to highlight the usefulness of anencephaly as a model when investigating immune-endocrine interactions. METHODS: Fifty-two anencephalics' autopsies were reviewed retrospectively...

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BACKGROUND: Talipes equinovarus (TEV), also called congenital idiopathic clubfoot, true clubfoot and common clubfoot, is one of the most common major birth defects. Its correction is often difficult and expensive. Its etiology is poorly understood and few analytic epidemiological studies have been devoted to exploring specific risk factors for TEV. METHODS: Our population-based study consists of 239 documented cases of idiopathic TEV obtained from hospital and outpatient sources and 365 controls identified via random digit dialing from five Western Washington counties...

BACKGROUND: Nonsyndromic orofacial clefts have an estimated incidence of 1/1000 live births. Population genetic and embryologic studies suggest that cleft palate only (CPO) may be a distinct clinical entity from cleft lip with or without cleft palate (CL/P). Both CPO and CL/P are thought to be multifactorial in etiology, with evidence indicating that genetic, environmental, and developmental determinants may all play a role. The ARNT2 gene localizes to a conserved linkage group on mouse chromosome 7 that is syntenic with human chromosome 15q23-25...

BACKGROUND: An integral component of developmental toxicity studies is the evaluation of fetal anatomy, which consists of external, visceral, and skeletal examinations. The visceral examination includes an assessment of the fetal head which, in the rat, is typically completed after chemical fixation. Because chemical fixation requires approximately 7 days, a comprehensive visceral examination, including the head, of the fetal rodent cannot be completed at the time of cesarean section...

BACKGROUND: Fetal aminopterin/methotrexate syndrome was described nearly 50 years ago when these agents were first used as abortifacients. Physicians essentially stopped using these agents when the associated anomalies were recognized. Over the last several years the use of methotrexate with or without misoprostol for management of ectopic pregnancy and medical terminations of pregnancy has increased. METHODS: A 23-year-old female sought a termination at eight weeks gestation...

BACKGROUND: A female fetus with massive truncal-limb hydrops and large, loculated, nuchal hygromas in midgestation is highly likely to have Turner syndrome. This phenotype is recognized to be usually lethal, with only more mildly affected fetuses surviving to term birth. METHODS: The morphology and morphometrics of 117 midgestation fetuses with phenotypic Turner syndrome were analyzed. RESULTS: More than 90% of fetuses with phenotypic Turner syndrome were found to have heart weights below the 2...