TL;DR: Zebrafish embryos were utilized to compare the developmental toxicity resulting from either ethanol or acetaldehyde exposure and demonstrate that the zebrafish model will provide an opportunity to further evaluate the mechanism of action of ethanol on vertebrate development.
TL;DR: Investigations of the mechanism of developmental toxicity are ongoing to attempt to determine whether rats and rabbits are more sensitive to artemisinins than humans, and no adverse drug-related developmental effects have been observed in a limited number of pregnant women treated with artesinins, primarily artesunate.
Abstract: The artemisinins are playing an increasingly important role in treating multidrug-resistant malaria. The artemisinin, artesunate, is currently in use in Southeast Asia and is advocated for use in Africa. In these areas, more than one million people die of malaria each year, with the highest mortality occurring in children and pregnant women. To test the developmental toxicity in ICH-compliant animal studies, embryofetal development studies were conducted in rats and rabbits treated with artesunate alone or a three-drug combination (CDA) consisting of chlorproguanil hydrochloride, Dapsone, and artesunate in the ratio 1.00:1.25:2.00. Developmental toxicity seen with CDA could be attributed to the administered dose of artesunate. The hallmark effect of artesunate exposure was a dramatic induction of embryo loss, apparent as abortions in rabbits and resorptions in both rats and rabbits. In addition, low incidences of cardiovascular malformations and a syndrome of skeletal defects were induced at or close to embryolethal doses of artesunate in both rats and rabbits. The cardiovascular malformations consisted of ventricular septal and vessel defects. The skeletal syndrome consisted of shortened and/or bent long bones and scapulae, misshapen ribs, cleft sternebrae, and incompletely ossified pelvic bones. These developmental effects were observed largely in the absence of any apparent maternal toxicity. The no or low adverse effect levels were in the range of 5 to 7 mg/kg/day artesunate. Encouragingly, no adverse drug-related developmental effects have been observed in a limited number of pregnant women (more than 100 first trimester and 600 second and third trimester) treated with artemisinins, primarily artesunate. Investigations of the mechanism of developmental toxicity are ongoing to attempt to determine whether rats and rabbits are more sensitive to artemisinins than humans.
TL;DR: It is concluded that prenatal exposure to a teratogenic Cd dose induced in the survivor animals several deleterious effects in their development as well as in adult behaviors, mainly in the sexual sphere.
TL;DR: Maternal food consumption was significantly decreased in the highest dose group over the dosing period (GD 6-20), and the maternal NOAEL for butylparaben was 100 mg/kg/day.
Abstract: The developmental toxicity potential of butylparaben (CAS No. 94-26-8) was evaluated in rats. Sprague-Dawley rats were administered butylparaben in 0.5% carboxymethylcellulose by oral gavage at dose levels of 0, 10, 100, or 1,000 mg/kg/day on gestation days (GD) 6-19 (sperm positive day = GD 0). Caesarean sections were performed on GD 20 and fetuses were evaluated for viability, growth, and external, visceral, and skeletal abnormalities. Each group consisted of 25 females, with at least 21 per group being pregnant. The highest dose level caused decreases in maternal weight gain during some of the measurement intervals and was statistically significant during the GD 18-20 interval. Maternal food consumption was significantly decreased in the highest dose group over the dosing period (GD 6-20). There were no differences from control in any of the developmental parameters measured, including embryo/fetal viability, fetal weight, malformations, or variations. Based on the results of this study, the maternal NOAEL for butylparaben was 100 mg/kg/day. Butylparaben does not have the potential to cause developmental toxicity in the Sprague-Dawley rat at oral dosages up to 1000 mg/kg/day.
TL;DR: The results from RT-PCR, in situ hybridization, and antioxidant-protection experiments indicate that the mechanism underlying growth retardation by arecoline in embryos is predominantly due to a general cytotoxic effect induced by depletion of intracellular thiols.
TL;DR: Therapeutic doses of chlordiazepoxide during pregnancy are unlikely to pose a substantial teratogenic risk to the human fetus, although a somewhat higher rate of congenital cardiovascular malformations cannot be excluded.
TL;DR: Overall, amphibian early life stages appeared more susceptible to the embryotoxicity associated with exposure to naringenin, especially at concentrations greater than 5 mg/l, which may result from the relatively high rates of cellular differentiation and morphogenesis that occur at this early stage of development.
TL;DR: It is suggested that a 14-day subcutaneous dose of 2-BP is embryotoxic and teratogenic at a maternally toxic dose and is minimally embryot toxic at a nonmaternally Toxic dose in Sprague-Dawley rats.
TL;DR: Fetal skeletal abnormalities observed at lovastatin dose levels > or =100 mkd are not due to a direct teratogenic effect, but are the result of excessive maternal toxicity, which most likely involves a nutritional deficiency associated with forestomach lesions and reduced maternal food intake.
TL;DR: Prenatal mortality, live litter size, fetal sex ratio, and morphological development were unaffected in both rats and mice andEmodin, a widely available herbal remedy, was evaluated for potential effects on pregnancy outcome.
TL;DR: The types of craniofacial malformations induced in the C57BL/6J mouse by meethanol indicate that methanol and ethanol have common targets and may have common modes of action.
Abstract: BACKGROUND: Exposure of pregnant outbred CD-1 mice to methanol during the period of gastrulation results in exencephaly, cleft palate, and cervical vertebra malformations [Rogers and Mole, Teratology 55: 364, 1997], while inbred C57BL/6J mice are sensitive to the teratogenicity of ethanol. C57BL/6J fetuses exhibit the holoprosencephaly spectrum of malformations after maternal exposure to ethanol during gastrulation, but the sensitivity of C57BL/6J mice to methanolinduced teratogenesis has not been previously described. METHODS: Pregnant C57BL/6J mice were administered two i.p. injections totaling 3.4 or 4.9 g/kg methanol or distilled water four hrs apart on gestation day (GD) 7. On GD 17, litters were examined for numbers of live, dead and resorbed conceptuses, fetuses were weighed as a litter and examined externally, and all fetuses were double stained for skeletal analysis. RESULTS: No maternal intoxication was apparent, but the high dosage level caused a transient deficit in maternal weight gain. The number of live fetuses per litter was reduced at both dosages of methanol, and fetal weight was lower in the high dosage group. Craniofacial defects were observed in 55.8% of fetuses in the low dosage group and 91.0% of fetuses in the high dosage group, including micro/ anophthalmia, holoprosencephaly, facial clefts and gross facial angenesis. Skeletal malformations, particularly of the cervical vertebrae, were observed at both dosages of methanol, and were similar to those previously reported in the CD-1 mouse following methanol exposure. CONCLUSIONS: The types of craniofacial malformations induced in the C57BL/ 6J mouse by methanol indicate that methanol and ethanol have common targets and may have common modes of action. Birth Defects Res B 71:80–88, 2004. Published 2004 Wiley-Liss, Inc. w
TL;DR: The prevalence of congenital malformations was not increased in offspring of males with laboratory work in general (1970–1989) and paternal work with agents such as carcinogens could, however, be of concern.
Abstract: Animal studies indicate male-mediated teratogenicity for certain carcinogens/mutagens. Nevertheless, paternal occupational determinants of malformations in humans have been sparsely investigated. Data on male employees at Swedish universities from 1970 to 1989 were linked to the Medical Birth Register. The relationship between major malformations and exposure to laboratory work and to specific laboratory agents/techniques before the third trimester were analyzed using logistic regression. For major malformations, "laboratory work in general" (n = 3237) gave an adjusted odds ratio (OR) of 1.3 (95% CI = 0.8-2.1) and carcinogenic solvent use (n = 2489) of 2.0 (95% CI = 0.8-4.9) around the time of conception. For carcinogenic solvents and neural crest malformations, OR was 4.9 (95% CI =1.5-15.8). In conclusion, the prevalence of congenital malformations was not increased in offspring of males with laboratory work in general (1970-1989). Paternal work with agents such as carcinogens could, however, be of concern.
TL;DR: Mechanistic studies of some teratogenic agents provided evidence of interference with regulation of genes controlling the embryonic development, and the new genomic technologies may represent a real improvement in understanding the mechanisms of action of chemical teratogens.
Abstract: Exposure of the embryo to environmental chemicals can result in congenital malformations or abortion Although experimental teratology data are considered sufficient for risk assessment, only knowledge of their mechanisms of action permits a justifiable extrapolation of animal data to humans Mechanistic studies of some teratogenic agents such as retinoic acids, valproic acid, diethylstilbestrol, and cyclopamine provided evidence of interference with regulation of genes controlling the embryonic development The new genomic technologies are important tools in this field and may represent a real improvement in understanding the mechanisms of action of chemical teratogens
TL;DR: It is concluded that all-trans retinoic acid leads to severe congenital malformations if administered before neurulation whereas if given after neurulation, it is not so teratogenic.
Abstract: Vitamin A metabolites are potent teratogens in a wide variety of species, including man. Transforming growth factor betas (TGF-βs) are involved in several mammalian prenatal developmental processes. The aim of this study was to determine the effects of exogenous and excessive all-trans retinoic acid on TGFβ2 expression in the developing cerebral cortex of the rat. Many of the malformations including exencephaly, exophtalmus, abdominal wall defects, extremity reduction defects observed in this study were dependent on the time of administration of retinoic acid. TGF-β2 was diversely expressed, as revealed immunohistochemically, in the cerebral cortex and plexus choroideus. The diversity depended on the gestational day and the was affected by the administration of retinoic acid. In the 15-day-old fetus from mothers who had been fed by gavage a single dose of 60 mg/kg body weight of all-trans retinoic acid on the 8th day of gestation, TGF-β2 immunoreactivity in the brain was decreased. However, by the 18th day of gestation, TGF-β2 expression increased. The expression of TGF-β2 in fetuses whose mothers had been given all-trans retinoic acid after the neurulation period (on day 12 of gestation) was generally similar to that in a control group. We conclude that all-trans retinoic acid leads to severe congenital malformations if administered before neurulation whereas if given after neurulation, it is not so teratogenic. Further, retinoic acid has a variable effect on the expression of TGF-β2.
TL;DR: These findings contribute to the characterization of both nitroimidazoles, which are widely used, especially in underdeveloped countries, and this Drosophila bioassay, sensitive enough to detect differential effects of MTZ and ONZ (abnormalities vs. growth effects), showing specificity and selectivity.
TL;DR: No evidence supports the conclusion that D-003 is a reproductive and developmental toxicant/teratogen, and pregnant New Zealand rabbits were given D-03 as oral doses of 500 and 1000 mg/kg/day on days 6 through 18 of gestation without any evidence of embryotoxicity or teratogenicity.
TL;DR: The critical period for IVL984 in the rat, GD 10 to 11, corresponds to the expression of alpha-4 integrin on the chorion and VCAM-1 on the allantois and myocardium as well as chorioallantoic fusion and formation of the spiral septum.
Abstract: BACKGROUND: Integrins such as VLA-4 (Very late antigen 4, integrin α4β1) play key roles in cell–cell interactions that are critical for development. Homozygous null knockouts of the VLA-4 α4-subunit or VCAM-1 (VLA-4 cell surface ligand) in mice result in failure of the allantois and chorion to fuse leading to interrupted placentation and cardiac development and embryo lethality. Embryo-fetal studies of three VLA-4 antagonists, IVL745, IVL984, and HMR1031 [Crofts et al., Birth Defects Res B 71:55–68 (this issue), 2004] with exposure on gestation days (GD) 6–17 (rat), 6–18 (rabbit) or 6–15 (mouse) showed that only IVL984 treatment resulted in embryo lethality and cardiac defects. Objectives of the current study were to determine the critical period for inducing IVL984-related embryo-fetal effects, and to test the hypothesis that these effects were due to higher embryo drug concentrations. METHODS: IVL984 was administered at 40 mg/kg/day to pregnant rats on GD 4 and 5, GD 6 and 7, GD 8 and 9, GD 10 and 11, or GD 12 and 13. Animals were euthanized on GD 21 and uteri and fetuses were examined. A treatment period of GD 10–12 was selected for subsequent toxicokinetic (TK) studies in which IVL984, HMR1031, or IVL745 was administered to pregnant rats and rabbits. On GD 12, maternal plasma, extra-embryonic tissue (placenta and amniotic fluid), and embryonic tissue were collected and analyzed for drug concentrations. RESULTS: In the IVL984 critical period study in pregnant rats, treatment on GD 10 and 11 resulted in increased post-implantation loss, skeletal variations, and spiral septal defects similar to those observed in standard embryo-fetal development studies with treatment throughout organogenesis. There were no embryo-fetal effects after treatment on GD 4 and 5, GD 6 and 7, or GD 8 and 9. There was a single aorta malformation after treatment on GD 12 and 13. In the TK studies, IVL745, HMR1031, and IVL984 were all detectable in embryonic tissue and there was no evidence for accumulation. Rat and rabbit embryo exposures (AUC or dose-adjusted AUC) on GD 12 could not explain the observed teratology (IVL984
TL;DR: There was no dose-dependent exposure and maternal toxicity to ISIS 2302, but no reproductive toxicity in rabbits, and exposure of fetus or pups is negligible.
TL;DR: This organ culture system of the fetal palate should be useful for screening the developmental toxicity of drugs and other environmental agents, and its value should increase when it is used in combination with other battery test systems.
Abstract: Using in vitro organ culture of the fetal mouse palate in a chemically defined serumless medium, the toxicity of 24 chemical compounds was investigated. Explanted palates of day-12.5 mouse fetuses were exposed for 72 h in vitro to various concentrations of each chemical, and the fusion rate and growth parameters were compared between the experimental group and respective controls. The average rate of palate fusion was 84% in vehicle controls. For compounds that are teratogenic in experimental animals in vivo, the fusion rates of palatal shelves decreased as the concentration of the test chemicals increased, showing a dose-dependent relationship. Palate fusion was inhibited by 11 of the 15 in vivo teratogens, and the predictability of in vivo developmental toxicity in this culture system was 73%. Cyclophosphamide itself did not inhibit the growth and fusion of explanted palates, but supplementation of hepatic S-9 fraction and cofactors for a monooxygenase system converted it to a toxic substance, as was shown in other in vitro systems. The 50% inhibitory concentration (IC50) value calculated based on the fusion rate was also found to be a useful parameter for evaluating the developmental toxicity of drugs. The teratogenic risk in the human fetus could be assessed by comparing the minimal toxic concentrations of the test compound on cultured palates with the maximal plasma level in pregnant women under therapeutic conditions and with the plasma concentrations when its minimal teratogenic dose is given to pregnant mice. This organ culture system of the fetal palate should be useful for screening the developmental toxicity of drugs and other environmental agents, and its value should increase when it is used in combination with other battery test systems.
TL;DR: Major impetus was grown to teratological research with the discovery of Gregg (1941) that German measles (rubella virus) of pregnant women caused birth defects in the embryo and the contergan disaster (1959--1962).
Abstract: Teratology is the science of congenital malformations. The incidence of birth defects amounts to 2-3%, but it doubles postnatal owing to the fact that many dysfunctions are not discernible at birth. Congenital malformations were already known in ancient cultures, records from Assyrian and Babylonian astrologists as well as from physicians and philosophers of the Hippocratic era are testifying it. In medieval times they were recognized as supernatural phenomenons, terata, from what the term TERATOLOGY derived. In the eyes of the superstitious people affected stillborns were regarded as monster, symbol of devil or miracle. The foundation of anatomy as a science by Vesalius marked the beginning of a reorientation. In the 17th century, when the age of enlightenment began, ideas concerning the origin of birth defects became more objective. Original studies dealing with congenital malformations became common in the 18th century. Fundamental discoveries made by microscopy placed Teratology on a truly scientific basis. Significant impetus was grown to teratological research with the discovery of Gregg (1941) that German measles (rubella virus) of pregnant women caused birth defects in the embryo and the contergan disaster (1959--1962). Congenital malformations originate from genetic factors (single gene defects and chromosomal aberrations) and environmental factors, such as radiation, drugs, chemicals, and infectious agents. The susceptibility of teratogen depends on the period of embryonal development, which is classified into gametogenesis, blastogenesis, embryogenesis and fetogenesis. The Food and Drug Administration of the USA published guidelines for teratogenetic testing (1966). There are in-vivo and in-vitro-test programmes, the latter became of increasing importance owing to the large number of chemicals to be tested and the activities of opponents against animal experiments. Although great advances were made, the problem remained to transfer results from in-vivo and in-vitro tests to the constitution of man without risk.
TL;DR: An experimental approach to counteract a circling performance deficit that appears in Sprague-Dawley rats at puberty on exposure to the dopaminergic blocker haloperidol (HAL) during gestation is tested and the role of critical periods of sensitivity as transient windows for opportunistic therapies for behavioral teratology is discussed.
TL;DR: The population-based data set of the Hungarian Case-Control Surveillance of Congenital Abnormalities, 1980-1996 contained 22843 fetuses or newborns with congenital abnormalities and 38151 matched controls without congenitals abnormalities, a signal for the potential teratogenic risk of tolnaftate in a case-control study, though the number of cases and controls were limited.
TL;DR: Polnoks R and its monomer 2,2,4-trimethyl-1,2-dihydroquinoline are teratogenic to rats and induces CNS, kidneys and skeletal defects.
Abstract: This study was performed to evaluate the effects of prenatal development of rats were exposed to Polnoks R and its monomer 2,2,4-trimethyl-1,2-dihydroquinoline (TMDHQ) by gavage every day on days 6-15 of gestation at doses equivalent 6%, 13% and 25% of LD50. Polnoks R and TMDHQ administered per os associated with significant maternal toxicity, embryonal lethality, retarded fetal development and congenital defects. Polnoks R induced skeletal malformations, internal hydrocephalus, and hydronephrosis. 2,2,4-trimethyl-1,2-dihydroquinoline produced internal malformations (exencephale, hydrocephalus, anophthalmia, hydronephrosis and renal hypoplasia) and skeletal malformations of ribs and vertebrae. Polnoks R monomer--2,2,4-trimethyl-1,2-dihydroquinoline is used as an antioxidant in elastomer and rubber productions. Polnoks R and its monomer 2,2,4-trimethyl-1,2-dihydroquinoline are teratogenic to rats and induces CNS, kidneys and skeletal defects.
TL;DR: It could be concluded that both garlic and cabbage seed extracts have protective effects in pregnant rats and garlic extract was found to have a greater protective effect than cabbage seed extract.
TL;DR: Dramatic differences in teratogenic potential were observed: IVL745 was not ter atogenic, HMR1031 caused slight embryo-fetal effects at maternally-toxic doses, and IVL984 was a potent teratogen at doses where direct maternal toxicity was limited to abortions in rabbits.
TL;DR: The study showed that even low sporadic doses of alcohol consumption during pregnancy may increase the risk of congenital anomalies in the offspring and that this risk increases with increasing levels of alcohol exposure.
TL;DR: The purpose of this article is to inform pediatricians about environmental drugs, chemicals, and physical agents that have been documented to produce congenital malformations and reproductive effects and to indicate that the multitude of teratogenic agents account for only a small proportion of mal Formations.
Abstract: There have been amazing advances in embryology, teratology, reproductive biology, genetics, and epidemiology in the past 50 years that have provided scientists and clinicians with a better perspective on the causes of congenital malformations. We still cannot provide the families of children with malformations a definitive diagnosis and cause in every instance. The purpose of this article is to inform pediatricians about environmental drugs, chemicals, and physical agents that have been documented to produce congenital malformations and reproductive effects and to indicate that the multitude of teratogenic agents account for only a small proportion of malformations. The most common known cause is genetic, but the largest group, unfortunately, There have been amazing advances in embryology, teratology, reproductive biology, genetics, and epidemiology in the past 50 years that have provided scientists and clinicians with a better perspective on the causes of congenital malformations. We still cannot provide the families of children with malformations a definitive diagnosis and cause in every instance. The purpose of this article is to inform pediatricians about environmental drugs, chemicals, and physical agents that have been documented to produce congenital malformations and reproductive effects and to indicate that the multitude of teratogenic agents account for only a small proportion of malformations. The most common known cause is genetic, but the largest group, unfortunately, is unknown. There are a number of important clinical rules that are important for clinicians to use when determining the cause of their patient's congenital malformations: 1. No teratogenic agent should be described qualitatively as a teratogen, because a teratogenic exposure includes not only the agent but also the dose and the time in pregnancy when the exposure has to occur. 2. Even agents that have been demonstrated to result in malformations cannot produce every type of malformation. Known teratogens may be presumptively implicated by the spectrum of malformations that they produce. It is easier to exclude an agent as a cause of birth defects than to conclude definitively that it was responsible for birth defects, because of the existence of genocopies of some teratogenic syndromes. 3. When evaluating the risk of exposures, the dose is a crucial component in determining the risk. Teratogenic agents follow a toxicologic dose-response curve. This means that each teratogen has a threshold dose below which there is no risk of teratogenesis, no matter when in pregnancy the exposure occurred. 4. The evaluation of a child with congenital malformations cannot be performed adequately unless it is approached with the same scholarship and intensity as the evaluation of any other complicated medical problem. 5. Each physician must recognize the consequences of providing erroneous reproductive risks to pregnant women who are exposed to drugs and chemicals during pregnancy or alleging that a child's malformations are attributable to an environmental agent without performing a complete and scholarly evaluation. 6. Unfortunately, clinical teratology and clinical genetics is not emphasized in medical school and residency education programs, but pediatricians have a multitude of educational aids to assist them in their evaluations, which includes consultations with clinical teratologists and geneticists, the medical literature, and the OMIM web site.
TL;DR: The present study indicates that the occurrence of brain, kidney, and liver lesions in combination treatment was less than in either individual treatment suggesting antagonism of OA-induced teratogenic effects by AFB1.
TL;DR: Genetic variability of multi-drug resistance protein 3 (MRP3) and its potential impact on function.
Abstract: Journal of Pediatric Gastroenterology and NutritionVolume 39, Issue S1 p. S34-S35 ABSTRACTS: Oral Presentation Abstracts O0071 GENETIC VARIABILITY OF MULTI-DRUG RESISTANCE PROTEIN 3: POSSIBLE IMPACT ON FUNCTION M. C. Stephens, M. C. Stephens Pediatric Gastroenterology and Nutrition, Clinical Pharmacology, Pharmacogenetics, and Teratology, Medical College of Wisconsin, Milwaukee, United StatesSearch for more papers by this authorA. Sommers, A. Sommers Pediatric Gastroenterology and Nutrition, Clinical Pharmacology, Pharmacogenetics, and Teratology, Medical College of Wisconsin, Milwaukee, United StatesSearch for more papers by this authorR. N. Hines, R. N. Hines Clinical Pharmacology, Pharmacogenetics, and Teratology, Medical College of Wisconsin, Milwaukee, United StatesSearch for more papers by this author M. C. Stephens, M. C. Stephens Pediatric Gastroenterology and Nutrition, Clinical Pharmacology, Pharmacogenetics, and Teratology, Medical College of Wisconsin, Milwaukee, United StatesSearch for more papers by this authorA. Sommers, A. Sommers Pediatric Gastroenterology and Nutrition, Clinical Pharmacology, Pharmacogenetics, and Teratology, Medical College of Wisconsin, Milwaukee, United StatesSearch for more papers by this authorR. N. Hines, R. N. Hines Clinical Pharmacology, Pharmacogenetics, and Teratology, Medical College of Wisconsin, Milwaukee, United StatesSearch for more papers by this author First published: 01 June 2004 https://doi.org/10.1002/j.1536-4801.2004.tb12379.x Submitted by: [email protected] Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onEmailFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Reference(S): 1.Collins, F. S., L. D. Brooks, et al. (1998). “A DNA polymorphism discovery resource for research on human genetic variation.” Genome Res 8 (12): 1229–31. 10.1101/gr.8.12.1229 CASPubMedWeb of Science®Google Scholar Volume39, IssueS1June 2004Pages S34-S35 ReferencesRelatedInformation