Teratogenic effects of ethanol vapour exposure on chick embryos

OBJECTIVE

To observe the effect of ethanol vapours on chick embryos regarding developmental defects and hatchability characteristics.

METHODS

An experimental study was performed in the Department of Anatomy at the Regional Center of College of Physicians and Surgeons, Islamabad, from February, 2006 to February, 2007. Chicken eggs after having been exposed to ethanol vapours produced in a specially designed glass chamber, were dissected on day 7, day 10 and day 22 or on hatching and compared with age-matched controls. A breathalyzer was used for monitoring level of ethanol vapours inside the incubator.

RESULTS

The results show that experimental group had comparatively more cases of delayed and assisted hatchings as well as growth retardation resulting into failure of retraction of yolk sac, as compared to the controls.

CONCLUSION

Ethanol vapour exposure increases the risks of developmental defects with increasing embryonic age. Increased duration of exposure, causes delayed hatching and more assisted hatchings. Newly hatched alcohol exposed chicks showed diminished locomotor activity and poor balance.

Significance of cannabis use to dental practice

The illicit use of the three main forms of cannabis-marijuana, hash, hash oil-pose certain obstacles and challenges to the dental professional. There are a number of systemic, as well as oral/head and neck manifestations, associated with cannabis use. Dentists need to be aware of these manifestations in order to take whatever precautions and/or modifications to the proposed treatment that might be necessary.

Herbicide exposure and veterans with covered service in Korea. Final rule

This document adopts as a final rule the Department of Veterans Affairs' (VA) proposal to amend VA adjudication, medical, and vocational rehabilitation and employment regulations to incorporate relevant provisions of the Veterans Benefits Act of 2003. Specifically, this document amends VA regulations regarding herbicide exposure of certain veterans who served in or near the Korean demilitarized zone and regulations regarding spina bifida in their children. It also amends VA's medical regulations by correcting the Health Administration Center's hand-delivery address.

Transcriptome analysis provides insights for understanding the adverse effects of endosulfan in Drosophila melanogaster

Indiscriminate use of agrochemicals worldwide, particularly, persistent organic pollutants (POPs), is of concern. Endosulfan, a POP, is used by various developing/developed nations and is known to adversely affect the development and the hormonal profiles of humans and animals. However, little is known about the molecular players/pathways underlying the adverse effects of endosulfan. We therefore analyzed the global gene expression changes and subsequent adverse effects of endosulfan using Drosophila. We used Drosophila melanogaster keeping in view of its well annotated genome and the wealth of genetic/molecular reagents available for this model organism. We exposed third instar larvae of D. melanogaster to endosulfan (2.0 μg mL(-1)) for 24 h and using microarray, we identified differential expression of 256 genes in exposed organisms compared to controls. These genes are associated with cellular processes such as development, stress and immune response and metabolism. Microarray results were validated through quantitative PCR and biochemical assay on a subset of genes/proteins. Taking cues from microarray data, we analyzed the effect of endosulfan on development, emergence and survival of the organism. In exposed organisms, we observed deformities in hind-legs, reminiscent of those observed in higher organisms exposed to endosulfan. In addition, we observed delayed and/or reduced emergence in exposed organisms when compared to their respective controls. Together, our studies not only highlight the adverse effects of endosulfan on the organism but also provide an insight into the possible genetic perturbations underlying these effects, which might have potential implications to higher organisms.

FETAX assay for evaluation of developmental toxicity

The Frog Embryo Teratogenesis Assay Xenopus (FETAX) test is a development toxicity screening test. Due to the small amount of compound needed and the capability to study organogenesis in a short period of time (96 h), FETAX test constitutes an efficient development toxicity alert test when performed early in drug safety development. The test is conducted on fertilized Xenopus laevis mid-blastula stage eggs over the organogenesis period. Compound teratogenic potential is determined after analysis of the mortality and malformation observations on larva. In parallel, FETAX test provides also information concerning embryotoxic effect based on larva length.

Use of Phenytoin in Pregnancy for Epileptic Seizure Prevention: A Case Report

Epilepsy is the most common neurological disorder in women of reproductive age. Phenytoin is one of the most frequently prescribed antiepileptic drugs. Although the vast majority of women with epilepsy have normal pregnancy outcomes, certain fetal anomalies and pregnancy complications are associated with epilepsy and phenytoin use. Appropriate midwifery care of women with epilepsy includes consultation and co-management with an obstetrician and a neurologist. The clinical course of a woman with epilepsy taking phenytoin is presented.

Cytogenetic and developmental toxicity of cerium and lanthanum to sea urchin embryos

The aim of this study was to evaluate the toxicity of two rare earth elements (REE), cerium and lanthanum on sea urchin embryos and sperm. Sea urchin (Paracentrotus lividus) embryos were reared for 72 h in Ce(IV)- or La(III)-contaminated seawater at concentrations ranging from 10(-8) to 10(-5) M. Cleaving embryos (5h post-fertilization) were submitted to cytogenetic analysis, scoring mitotic activity and a set of mitotic aberrations. Embryological analysis was carried out to determine percent developmental anomalies and/or embryonic mortality. P. lividus sperm were suspended in Ce(IV) or La(III) (10(-8)-10(-5)M) for 1h, and percent fertilized eggs were scored in cleaving embryos that were cultured up to pluteus stage to score any developmental defects. Embryos reared in 10(-5)M Ce(IV) resulted in 100% embryonic mortality, whereas 10(-5)M La(III) induced 100% developmental defects, without causing any embryonic mortality. A significant concentration-related mitotoxic effect and induction of mitotic aberrations were observed in Ce(IV)-exposed, but not in La(III)-exposed embryos, at concentrations ranging from 10(-7)M to 3 x 10(-6)M. Following sperm exposure, both Ce(IV) and La(III) induced a decrease in sperm fertilization success at the highest tested concentration (10(-5)M). The offspring of Ce(IV)-exposed, but not of La(III)-exposed sperm displayed a significant concentration-related increase in developmental defects. The results may suggest adverse impacts in REE-exposed biota and warrant further studies of a more extended REE series.

Determination of the di-(2-ethylhexyl) phthalate NOAEL for reproductive development in the rat: importance of the retention of extra animals to adulthood

Deriving No Observed Adverse Effect Level (NOAEL) or benchmark dose is important for risk assessment and can be influenced by study design considerations. In order to define the di-(2-ethylhexyl) phthalate (DEHP) dose-response curve for reproductive malformations, we retained more offspring to adulthood to improve detection of these malformations in the reproductive assessment by continuous breeding study design. Sprague-Dawley rats were given a dietary administration of 1.5 (control), 10, 30, 100, 300, 1000, 7500, and 10,000 ppm DEHP. Male pups were evaluated for gross reproductive tract malformations (RTMs) associated with the "phthalate syndrome." DEHP treatment had minimal effects on P0 males. There was a statistically significant increase in F1 and F2 total RTMs (testis, epididymides, seminal vesicle, and prostate) in the 7500-ppm dose group and F1 10,000-ppm dose group. The 10,000-ppm exposed F1 males did not produce an F2 generation. The NOAEL for F1 and F2 RTM combined data, because in utero exposures were similar, were 100 ppm (4.8 mg/kg/day), which was close to the 5% response benchmark dose lower confidence limit of 142 ppm. The utility of evaluating more pups per litter was examined by generating power curves from a Monte Carlo simulation. These curves indicate a substantial increase in detection rate when three males are evaluated per litter rather than one. A 10% effect across male pups would be detected 5% of the time if one pup per litter was evaluated, but these effects would be detected 66% of the time if three pups per litter were evaluated. Taken together, this study provides a well-defined dose response of DEHP-induced RTMs and demonstrates that retention of more adult F1 and F2 males per litter, animals that were already produced, increases the ability to detect RTMs and presumably other low-incidence phenomena.

Evaluation of Bauhinia monandra aqueous and ethanol extracts in pregnant rats

Bauhinia monandra Kurz. (Fabaceae: Caesalpinioideae) is a plant widely employed in Brazilian folk medicine for hypoglycemia. However, little is known about the effect of maternal exposure to this plant on fetal development. The aqueous and ethanol extracts obtained from B. monandra dried leaves were administered to pregnant Wistar rats throughout gestation (day 1 to day 20) at 1,400 or 7,000 mg/kg/day (n = 6/group). Maternal toxicity was not observed in the dams of both groups, and was evaluated by observing body weight, water and food intake during treatment, by measuring serum biochemical levels of creatinine, urea, AST and ALT, and by studying the histopathology of liver, kidney, pancreas, spleen and uterus at the end of treatment (gestation day 20). Both extracts and doses did not impair reproductive performance or delay fetal development, measured by observing implantations and reabsorptions in the uterus, by counting the number of corpora lutea in ovaries, by recording the litter weight and number of live and dead fetuses and by analyzing possible skeleton and viscera malformations in the fetuses. Also, the aqueous extract promoted decreased post-implantation loss when compared to the control group. The aqueous and ethanol extracts from B. monandra dried leaves (1,400 or 7,000 mg/kg/day) did not cause maternal or fetal toxicities and the aqueous extract promoted increased implantation and decreased post-implantation loss in the pregnant rats.

Developmental neurotoxicity study of dietary bisphenol A in Sprague-Dawley rats

This study was conducted to determine the potential of bisphenol A (BPA) to induce functional and/or morphological effects to the nervous system of F(1) offspring from dietary exposure during gestation and lactation according to the Organization for Economic Cooperation and Development and U.S. Environmental Protection Agency guidelines for the study of developmental neurotoxicity. BPA was offered to female Sprague-Dawley Crl:CD (SD) rats (24 per dose group) and their litters at dietary concentrations of 0 (control), 0.15, 1.5, 75, 750, and 2250 ppm daily from gestation day 0 through lactation day 21. F(1) offspring were evaluated using the following tests: detailed clinical observations (postnatal days [PNDs] 4, 11, 21, 35, 45, and 60), auditory startle (PNDs 20 and 60), motor activity (PNDs 13, 17, 21, and 61), learning and memory using the Biel water maze (PNDs 22 and 62), and brain and nervous system neuropathology and brain morphometry (PNDs 21 and 72). For F(1) offspring, there were no treatment-related neurobehavioral effects, nor was there evidence of neuropathology or effects on brain morphometry. Based on maternal and offspring body weight reductions, the no-observed-adverse-effect level (NOAEL) for systemic toxicity was 75 ppm (5.85 and 13.1 mg/kg/day during gestation and lactation, respectively), with no treatment-related effects at lower doses or nonmonotonic dose responses observed for any parameter. There was no evidence that BPA is a developmental neurotoxicant in rats, and the NOAEL for developmental neurotoxicity was 2250 ppm, the highest dose tested (164 and 410 mg/kg/day during gestation and lactation, respectively).

Congenital abnormalities in children of 43 pregnant women who attempted suicide with large doses of nitrazepam

OBJECTIVE

To evaluate the teratogenic effect of very large doses of nitrazepam in children born to pregnant women who attempted suicide and to check the feasibility of self-poisoning pregnant women model.

DESIGN AND SETTING

Comparative analysis of exposed children and their unexposed sibs born to the same mothers who attempted suicide during the study pregnancy and admitted to the toxicological inpatients clinic, Budapest, 1960-1993.

STUDY PARTICIPANTS

Of 1044 pregnant women who attempted suicide, 107 (10.3%) used large doses of nitrazepam alone or combination with other drugs, and 43 delivered live-born babies, these exposed children were evaluated.

MAIN OUTCOMES MEASURES

Structural birth defects, i.e., congenital abnormalities (CAs), pregnancy age at delivery, and birth weight.

RESULTS

The mean dose of nitrazepam used for suicide attempt was 204 mg. Of 43 exposed children, 13 (30.2%) were affected with CAs, while of their 29 sib controls, 3 (10.3%) (OR with 95%CI: 3.8, 1.0-14.6). Most CAs in exposed children were mild and belonged to the deformation type. The mean pregnancy age was shorter.

CONCLUSIONS

The very large doses of nitrazepam used for suicide attempt during pregnancy resulted in a high rate of CAs which may be connected with the disruption of protein metabolism in fetal mesenchyma. The self-poisoning pregnant women model is feasible for the evaluation of teratogenic effect of drugs.

Biosynthesis and toxicological effects of patulin

Patulin is a toxic chemical contaminant produced by several species of mold, especially within Aspergillus, Penicillium and Byssochlamys. It is the most common mycotoxin found in apples and apple-derived products such as juice, cider, compotes and other food intended for young children. Exposure to this mycotoxin is associated with immunological, neurological and gastrointestinal outcomes. Assessment of the health risks due to patulin consumption by humans has led many countries to regulate the quantity in food. A full understanding of the molecular genetics of patulin biosynthesis is incomplete, unlike other regulated mycotoxins (aflatoxins, trichothecenes and fumonisins), although the chemical structures of patulin precursors are now known. The biosynthetic pathway consists of approximately 10 steps, as suggested by biochemical studies. Recently, a cluster of 15 genes involved in patulin biosynthesis was reported, containing characterized enzymes, a regulation factor and transporter genes. This review includes information on the current understanding of the mechanisms of patulin toxinogenesis and summarizes its toxicological effects.

Ochratoxin a: general overview and actual molecular status

Ochratoxin A (OTA) is a mycotoxin produced by several species of Aspergillus and Penicillium fungi that structurally consists of a para-chlorophenolic group containing a dihydroisocoumarin moiety that is amide-linked to L-phenylalanine. OTA is detected worldwide in various food and feed sources. Studies show that this molecule can have several toxicological effects such as nephrotoxic, hepatotoxic, neurotoxic, teratogenic and immunotoxic. A role in the etiology of Balkan endemic nephropathy and its association to urinary tract tumors has been also proved. In this review, we will explore the general aspect of OTA: physico-chemical properties, toxicological profile, OTA producing fungi, contaminated food, regulation, legislation and analytical methods. Due to lack of sufficient information related to the molecular background, this paper will discuss in detail the recent advances in molecular biology of OTA biosynthesis, based on information and on new data about identification and characterization of ochratoxin biosynthetic genes in both Penicillium and Aspergillus species. This review will also cover the development of the molecular methods for the detection and quantification of OTA producing fungi in various foodstuffs.

Effects of tributyltin (TBT) on Xenopus tropicalis embryos at environmentally relevant concentrations

Tributyltin (TBT) has been widely used as a biocide in antifouling paints and is a known endocrine disrupting chemical. In this paper, we exposed embryos of Xenopus tropicalis to 50-400ngL(-1) tributyltin chloride. TBT significantly decreased the survival rate, reduced the body length and retarded the development of embryos after 24, 36 and 48h of exposure. These effects of TBT were concentration- and time-dependent. Embryos treated with TBT showed multiple malformations. The most obvious alterations were abnormal eyes, enlarged proctodaeum, narrow fins, and skin hypopigmentation. Enlarged proctodaeum and narrow fins were mainly observed after 36 and 48h of exposure. The loss of eye pigmentation or the absence of external eyes occurred after 24 and 36h of exposure, while extended lenses or edemas of eyes were more commonly observed after 48h of exposure. Additional malformations included: small anterior region of heads, pericardial edemas, enlarged trunks, and bent tails. These results suggested that TBT is very toxic to X. tropicalis embryos at environmentally relevant concentrations.

Polluted-site killifish (Fundulus heteroclitus) embryos are resistant to organic pollutant-mediated induction of CYP1A activity, reactive oxygen species, and heart deformities

Exposure to coplanar polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs) can adversely affect fish embryonic development, induce expression of cytochrome P4501A (CYP1A), and increase reactive oxygen species (ROS) production, effects believed to be mediated by the aryl hydrocarbon receptor (AHR). Killifish (Fundulus heteroclitus) populations in New Bedford Harbor, Massachusetts, USA (NBH) and Newark Bay, New Jersey, USA (NB) are generationally exposed to coplanar PCBs and PAHs and have developed resistance to PCB mediated induction of CYP1A. We hypothesized that fish resistant to CYP1A induction would also exhibit resistance to PCB and PAH induced ROS production and teratogenesis. Killifish embryos from two contaminated (NB, NBH) and two reference-site populations were exposed to vehicle or 3,3'4,4'5-pentachlorobiphenyl (PCB126) or 3-methylcholanthrene (3-MC) and evaluated for in ovo CYP1A activity, heart deformities, and ROS production. Both chemicals significantly increased in ovo ethoxyresorufin-O-deethylase (EROD) and ROS production in reference-site embryos. These chemicals provoked only moderate induction of in ovo EROD in NBH and NB embryos, and neither PCB126 nor 3-MC induced ROS production in these populations. Similarly, heart deformities were significantly induced by PCB126 in reference-site embryos, but had no significant effects on NB and NBH animals. These results indicate that fish resistant to CYP1A induction also exhibit decreased sensitivity to PCB126 and 3-MC-induced ROS production and teratogenesis. These findings further our understanding of toxicant resistance by demonstrating that reduced response to coplanar PCBs and PAHs extends beyond resistance to CYP1A induction to resistance to the physiological and teratogenic effects of these toxicants, responses that undoubtedly contribute to the increased survival of killifish inhabiting contaminated sites.

Effect of nitrite on early-life stages of common carp (Cyprinus carpio L.)

A one-month chronic exposure of common carp larvae and embryos to nitrite revealed significant (p < 0.01) differences in total accumulated mortality in fish exposed to 33, 67, and 330 mg/L NO(2)(-) compared with controls. At the highest concentration, all fish died within 8 d of exposure. On the basis of accumulated mortality in the experimental groups, lethal concentrations of nitrite were estimated at 29 d LC50 = 88 mg/L NO(2)(-); lowest-observed-effect concentration (LOEC) = 28 mg/L NO(2)(-); and no-observed-effect concentration (NOEC) = 7 mg/L NO(2)(-). Fulton's condition factor values were significantly lower in fish from all experimental groups compared with controls. By day 12, fish exposed to 33 and 67 mg/L NO(2)(-) had significantly lower mass and total length compared with controls. No significant negative effects of nitrite at the concentrations tested (0.7-330 mg/L NO(2)(-), at 10 mg/L Cl(-)) on hatching or embryo viability were demonstrated, but significant differences in early ontogeny among groups were noted. Fish from all the concentrations showed a dose-related delay in development compared with the controls. Lordosis, kyphosis, scoliosis, and body shortening were observed at all concentrations and in controls, as was yolk sac deformation and edema, eye deformation, and cardiac edema. The incidence of these malformations was positively correlated with nitrite concentration. Histopathology revealed epidermal spongiosis; edema and hyperplasia of the gill epithelium, including hypertrophy and hyperplasia of eosinophilic granular cells (chloride cells); and interstitial edema of skeletal muscle in fish exposed to 67 mg/L NO(2)(-). Similar, but milder, changes were observed at lower nitrite concentrations.