OBJECTIVE: Exposure to polycyclic aromatic hydrocarbons (PAHs) or metal(loid)s individually has been associated with neural tube defects (NTDs). However, the impacts of PAH and metal(loid) co-exposure and potential interaction effects on NTD risk remain unclear. We conducted a case-control study in China among population with a high prevalence of NTDs to investigate the combined effects of PAH and metal(loid) exposures on the risk of NTD. METHODS: Cases included 80 women who gave birth to offspring with NTDs, whereas controls were 50 women who delivered infants with no congenital malformations. We analyzed the levels of placental PAHs using gas chromatography and mass spectrometry, PAH-DNA adducts with ³²P-post-labeling method, and metal(loid)s with an inductively coupled plasma mass spectrometer. Unconditional logistic regression was employed to estimate the associations between individual exposures and NTDs. Least absolute shrinkage and selection operator (LASSO) penalized regression models were used to select a subset of exposures, while additive interaction models were used to identify interaction effects. RESULTS: In the single-exposure models, we found that eight PAHs, PAH-DNA adducts, and 28 metal(loid)s were associated with NTDs. Pyrene, selenium, molybdenum, cadmium, uranium, and rubidium were selected through LASSO regression and were statistically associated with NTDs in the multiple-exposure models. Women with high levels of pyrene and molybdenum or pyrene and selenium exhibited significantly increased risk of having offspring with NTDs, indicating that these combinations may have synergistic effects on the risk of NTDs. CONCLUSION Our findings suggest that individual PAHs and metal(loid)s, as well as their interactions, may be associated with the risk of NTDs, which warrants further investigation.
Humans ; Neural Tube Defects/chemically induced* ; Polycyclic Aromatic Hydrocarbons/adverse effects* ; Female ; Case-Control Studies ; China/epidemiology* ; Adult ; Pregnancy ; Environmental Pollutants ; Maternal Exposure/adverse effects* ; Metals/toxicity* ; Young Adult ; Risk Factors

Adult ; Anesthesia, Epidural ; adverse effects ; Anesthesia, Spinal ; adverse effects ; Female ; Humans ; Neural Tube Defects ; complications ; Pregnancy ; Spinal Cord Compression ; chemically induced

OBJECTIVEOur objective is to build a model that explains the association between the exposure to trace elements in the soil and the risk of neural tube defects.

METHODSWe built a function with different parameters to describe the effects of trace elements on neural tube defects. The association between neural tube defects and trace element levels was transformed into an optimization problem using the maximum likelihood method.

RESULTSTin, lead, nickel, iron, copper, and aluminum had typical layered effects (dosage effects) on the prevalence of neural tube defects. Arsenic, selenium, zinc, strontium, and vanadium had no effect, and molybdenum had one threshold value that affected the prevalence of birth defects.

CONCLUSIONAs an exploratory research work, our model can be used to determine the direction of the effect of the trace element content of cultivated soil on the risk of neural tube defects, which shows the clues by the dosage effect of their toxicological characteristics. Based on our findings, future biogeochemical research should focus on the direct effects of trace elements on human health.

China ; epidemiology ; Dose-Response Relationship, Drug ; Environmental Exposure ; Female ; Humans ; Metals ; chemistry ; toxicity ; Models, Biological ; Neural Tube Defects ; chemically induced ; epidemiology ; Pregnancy ; Prevalence ; Soil Pollutants ; chemistry ; toxicity ; Trace Elements ; chemistry ; toxicity

OBJECTIVETo study the effect of folic acid cooperating with soybean isoflavone on the oxidative status of neural tube defects (NTDs) pregnant rats induced by cyclophosphamide, to observe the relationship of the two factors, folic acid and the isoflavone and to look for the best co-intervention group.

METHODSThe 100 pregnant rats of 2.5-3 months old were randomly divided into the control group, model group, co-intervention groups and solo-intervention groups. The animals were executed on the 20th day of gestation as to examining the levels of antioxidative indices (GSH, GSH-Px, Se, Mn, Fe) in blood. The incidence rates of NTDs were calculated.

RESULTSThe interaction of folic acid and isoflavone had significant effect on the indices related with antioxidation (P < 0.05). Folic acid 0.7 mg/kg cooperated with isoflavone 160 mg/kg had the best intervention effects in our study. Compared with the solo-intervention by folic acid 1.4 mg/kg and isoflavone 320 mg/kg, the effect of co-intervention (folic acid 0.7 mg/kg cooperated with isoflavone 160 mg/kg) was significantly better (P < 0.05).

CONCLUSIONFolic acid should be the main protective factor of NTDs, and isoflavone might reinforce the protective effects of folic the acid on NTDs by increasing the antioxidative ability, however, the effect is related with the ratio of the two factors.

Animals ; Cyclophosphamide ; Drug Interactions ; Female ; Folic Acid ; pharmacology ; Isoflavones ; pharmacology ; Male ; Neural Tube Defects ; chemically induced ; prevention & control ; Pregnancy ; Rats ; Rats, Wistar ; Soybeans ; chemistry

To elucidate the early sequential morphogenetic progress of exencephaly and myeloschisis, rat embryos whose mothers had been treated with hypervitaminosis A were studied at 1-day interval from gestation day 10.5 to 15.5. In exposed animals sequential change was found in both exencephaly and myeloschisis as the embryos grew up. The 10.5-day old exencephalic embryos had still widely open cephalic neural tubes. Exencephalic embryos older than 13.5 days of gestation showed strikingly severe eversion and overgrowth of the cephalic neuroepithelium, thus failed in forming normal primitive brain. The convex dorsal surface of the exencephaly was covered with ependyma, which was connected directly with surrounding surface eqithelium at the periphery. The earliest morphologically recognized myeloschisis was in the 13.5-day old embryos. In myeloschisis, divergence at the roof plate and eversion of the spinal neural tube, disorganized overgrowth of the neuroepithelium, malformed and misplaced spinal ganglia and nerve roots, and absence of the neural arch and dermal covering were characteristic. It is suggested that exencephaly results from failure of the cephalic neural tube closure which is followed by eversion and overgrowth of the neuroepithelium. And failure in closure of the posterior neuropore and disturbance in the development of the tail bud probably play major role in the morphogenesis of myeloschisis.
Animals ; *Embryonic and Fetal Development ; Female ; Hypervitaminosis A ; Neural Tube Defects/chemically induced/*pathology ; Pregnancy ; Rats ; Rats, Inbred Strains ; Spinal Cord/*abnormalities/embryology