Identification of novel nutrient-sensitive gene regulatory networks in amniocytes from fetuses with spina bifida.

Neural tube defects (NTDs) remain among the most common congenital anomalies. Contributing risk factors include genetics and nutrient deficiencies, however, a comprehensive assessment of nutrient-gene interactions in NTDs is lacking. We applied a nutrient-focused gene expression analysis pipeline to identify nutrient-sensitive gene regulatory networks in amniocyte gene expression data (GSE4182) from fetuses with NTDs (cases; n = 3) and fetuses with no congenital anomalies (controls; n = 5). Differentially expressed genes (DEGs) were screened for having nutrient cofactors. Nutrient-dependent transcriptional regulators (TRs) that regulated DEGs, and nutrient-sensitive miRNAs with a previous link to NTDs, were identified. Of the 880 DEGs in cases, 10% had at least one nutrient cofactor. DEG regulatory network analysis revealed that 39% and 52% of DEGs in cases were regulated by 22 nutrient-sensitive miRNAs and 10 nutrient-dependent TRs, respectively. Zinc- and B vitamin-dependent gene regulatory networks (Zinc: 10 TRs targeting 50.6% of DEGs; B vitamins: 4 TRs targeting 37.7% of DEGs, 9 miRNAs targeting 17.6% of DEGs) were dysregulated in cases. We identified novel, nutrient-sensitive gene regulatory networks not previously linked to NTDs, which may indicate new targets to explore for NTD prevention or to optimise fetal development.

Effects of general anesthesia with and without thoracic epidural block on length of stay after open spine surgery: a single-blinded randomized controlled trial.

BACKGROUND CONTEXT: Length of hospital stay (LOS) is an important concern in all types of surgery, and the enhanced recovery after surgery (ERAS) protocol has been developed to improve perioperative management and outcomes, which require multidisciplinary management. In terms of pain control, intraoperative regional anesthesia and postoperative opioid-sparing analgesia are recommended. For open spine surgery, we aimed to combine thoracic epidural analgesia to reduce pain and opioid-related side effects, thereby hastening recovery. PURPOSE: This study aimed to compare the length of hospital stay after open complete laminectomy with fusion between general anesthesia and combined general anesthesia involving a single thoracic epidural injection. DESIGN: A randomized single-blinded controlled study. PATIENT SAMPLE: Thirty-eight patients scheduled for elective open laminectomy with fusion between I and III levels were selected. OUTCOME MEASURES: LOS, postoperative pain, patient-controlled morphine consumption at 24 hours, patient satisfaction score, and other opioid-related side effects were recorded. METHODS: Patients were randomly selected to receive standard general anesthesia (GA) or GA combined with a single-shot thoracic epidural at T11-T12 or T12-L1, a block with 10 mL of 0.25% bupivacaine, and 4 mg of morphine. RESULTS: There were no significant differences in the demographic variables between groups. LOS was significantly lower in the combined epidural and/or GA than in the control group (3.78±0.81 [mean±standard deviation] and 4.79±1.51 days, respectively; p=.017). Numeric rating score (at rest) at the post-anesthesia care unit, 24 hours postoperative morphine consumption (mg), operating time, and blood loss were significantly lower in the epidural group. Patients who received combined epidural and/or GA were more likely to report higher patient satisfaction (p=.008). However, the incidence of intraoperative hypotension was significantly higher in the epidural group (72.2% vs. 21.1%, p=.003). The incidences of adverse events and surgical field rating scores did not differ between the 2 patient groups. CONCLUSIONS: Combined lower thoracic epidural and/or GA in patients undergoing elective lumbar spine surgery was associated with decreased LOS.

[Research progress on the etiology and pathogenesis of spina bifida].

OBJECTIVE: To review the research progress on etiology and pathogenesis of spina bifida. METHODS: By consulting relevant domestic and foreign research literature on spina bifida, the classification, epidemic trend, pathogenesis, etiology, prevention and treatment of it were analyzed and summarized. RESULTS: Spina bifida, a common phenotype of neural tube defects, is classified based on the degree and pattern of malformation associated with neuroectodermal involvement and is due to the disturbance of neural tube closure 28 days before embryonic development. The prevalence of spina bifida varies greatly among different ethnic groups and regions, and its etiology is complex. Currently, some spina bifida patients can be prevented by folic acid supplements, and with the improvement of treatment technology, the short-term and long-term survival rate of children with spina bifida has improved. CONCLUSION: The research on the pathogenesis of spina bifida will be based on the refined individual information on exposure, genetics, and complex phenotype, and will provide a theoretical basis for improving prevention and treatment strategies through multidisciplinary cooperation.

Fetal and Perinatal Expression Profiles of Proinflammatory Cytokines in the Neuroplacodes of Rats with Myelomeningoceles: A Contribution to the Understanding of Secondary Spinal Cord Injury in Open Spinal Dysraphism.

The cellular and molecular mechanisms that presumably underlie the progressive functional decline of the myelomeningocele (MMC) placode are not well understood. We previously identified key players in post-traumatic spinal cord injury cascades in human MMC tissues obtained during postnatal repair. In this study, we conducted experiments to further investigate these mediators in the prenatal time course under standardized conditions in a retinoic acid-induced MMC rat model. A retinoic acid MMC model was established using time-dated Sprague-Dawley rats, which were gavage-fed with all-trans retinoic acid (RA; 60 mg/kg) dissolved in olive oil at E10. Control animals received olive oil only. Fetuses from both groups were obtained at E16, E18, and E22. The spinal cords (SCs) of both groups were formalin-fixed or snap-frozen. Tissues were screened by real-time reverse transcription polymerase chain reaction for the expression of cytokines and chemokines known to play a role in the lesion cascades of the central nervous system after trauma. MMC placodes exhibited inflammatory cells and glial activation in the later gestational stages. At the messenger RNA (mRNA) level, interleukin-1 beta, tumor necrosis factor alpha, and tumor necrosis factor receptor type 1 exhibited significant induction at E22. interleukin-1 beta receptor type 1 mRNA was induced significantly at E16 and E22. Double labeling experiments confirmed the co-staining of these cytokines and their receptors with ionized calcium-binding adapter molecule 1 (i.e., inflammatory cells), vimentin, and nestin in different anatomical SC areas and neuronal nuclear protein in ventral horn neurons. C-X-C motif chemokine 12 mRNA was elevated in control and MMC animals at E16 compared with E18 and E22. C-X3-C motif ligand 1 mRNA was lower in MMC tissues than in control tissues on E16. The presented findings contribute to the concept that pathophysiological mechanisms, such as cytokine induction in the neuroplacode, in addition to the "first hit," promote secondary spinal cord injury with functional loss in the late fetal time course. Further, these mediators should be taken into consideration in the development of new therapeutic approaches for open spinal dysraphism.

Periconceptional nonsteroidal anti-inflammatory drug use, folic acid intake, and the risk of spina bifida.

BACKGROUND: Use of nonsteroidal anti-inflammatory drugs (NSAIDs) during pregnancy may increase risk for neural tube defects (NTDs), including spina bifida. Folic acid intake can prevent NTDs, but it is not known whether it modifies any risks associated with NSAID use. OBJECTIVES: To assess the impact of periconceptional NSAID use on the risk of spina bifida overall and stratified by folic acid intake. STUDY DESIGN: We analyzed 1998-2015 data from the Slone Epidemiology Center Birth Defects Study, a multi-site, case-control study. Mothers were interviewed to identify sociodemographic factors, behaviors, and exposures during pregnancy. Periconceptional NSAID use was defined as use of aspirin, ibuprofen, naproxen, or COX2 inhibitors within the month before or after the last menstrual period. Logistic regression models were used to estimate adjusted odds ratios (aORs) and 95% confidence intervals (CIs) for NSAID use, adjusted for study center and race/ethnicity stratified by average daily folic acid intake above ("high FA") or below ("low FA") 400 mcg/day. RESULTS: We compared mothers of 267 infants with spina bifida to mothers of 6,233 nonmalformed controls. Among control mothers, 20% used NSAIDS periconceptionally (16% ibuprofen, 4% aspirin, 3% naproxen, and <1% COX-2 inhibitors). For any NSAID use, the aORs among low FA and high FA women were 1.70 (95% CI [1.13, 2.57]) and 1.09 (95% CI [0.69, 1.71]), respectively. CONCLUSIONS: We observed a small increase in the risk for spina bifida among infants born to women who used NSAIDs periconceptionally, but this risk was limited to those who had inadequate folic acid intake.

Parental metal exposures as potential risk factors for spina bifida in Bangladesh.

BACKGROUND: Neural tube defects are a pressing public health concern despite advances in prevention from folic acid-based strategies. Numerous chemicals, in particular arsenic, have been associated with neural tube defects in animal models and could influence risk in humans. OBJECTIVES: We investigated the relationship between parental exposure to arsenic and 17 metals and risk of neural tube defects (myelomeningocele and meningocele) in a case control study in Bangladesh. METHODS: Exposure assessment included analysis of maternal and paternal toenail samples using inductively coupled plasma mass spectrometry (ICP-MS). A total of 278 participants (155 cases and 123 controls) with data collected from 2016 to 2020 were included in the analysis. RESULTS: In the paternal models, a one-unit increase in the natural logarithm of paternal toenail arsenic was associated with a 74% (odds ratio: 1.74, 95% confidence interval: 1.26-2.42) greater odds of having a child with spina bifida, after adjusting for relevant covariates. Additionally, paternal exposure to aluminum, cobalt, chromium, iron, selenium, and vanadium was associated with increased odds of having a child with spina bifida in the adjusted models. In the maternal models, a one-unit increase in the natural logarithm of maternal toenail selenium and zinc levels was related to a 382% greater (odds ratio: 4.82, 95% confidence interval: 1.32-17.60) and 89% lower (odds ratio: 0.11, 95% confidence interval: 0.03-0.42) odds of having a child with spina bifida in the adjusted models, respectively. Results did not suggest an interaction between parental toenail metals and maternal serum folate. DISCUSSION: Parental toenail levels of numerous metals were associated with increased risk of spina bifida in Bangladeshi infants. Paternal arsenic exposure was positively associated with neural tube defects in children and is of particular concern given the widespread arsenic poisoning of groundwater resources in Bangladesh and the lack of nutritional interventions aimed to mitigate paternal arsenic exposure. The findings add to the growing body of literature of the impact of metals, especially paternal environmental factors, on child health.

Prevalence of open neural tube defects and risk factors related to isolated anencephaly and spina bifida in live births from the "Dr. Juan I. Menchaca" Civil Hospital of Guadalajara (Jalisco, Mexico).

We determine the prevalence and trends of open neural tube defects (ONTDs) during 1991 to 2019 at the "Dr. Juan I. Menchaca" Civil Hospital of Guadalajara (Mexico). Also, details of potential risks were obtained in 662 newborns, including those 143 patients with anencephaly and open spina bifida (OSB) classified as isolated (cases) and 519 controls. Data were analyzed using multivariable logistic regression. Among 267 201 live births during the study period, 336 were born with ONTDs, yielding an overall prevalence of 12.6 per 10 000. After folic acid (FA)-related programs began in Mexico (2003-2019), only OSB showed a decline of 20.6%. For anencephaly, associated risks included relatives with neural tube defects (NTDs) (adjusted odds ratio [aOR]: 67.9, 95% confidence interval [95% CI]: 11.3-409.8), pre-pregnancy body mass index (BMI) ≥25 kg/m2 (aOR: 2.6, 95% CI: 1.1-6.0), insufficient gestational weight gain (aOR: 3.0, 95% CI: 1.3-7.1), parity ≥4 (aOR: 3.2, 95% CI: 1.3-7.7), and exposure to analgesic/antipyretic drugs (aOR: 9.0; 95% CI: 2.5-33.0). For OSB, associated risks included consanguinity (aOR: 14.0, 95% CI: 3.5-55.9), relatives with NTDs (aOR: 22.4, 95% CI: 4.5-112.9), BMI ≥25 kg/m2 (aOR: 2.5, 95% CI: 1.6-4.2), insufficient gestational weight gain (aOR: 1.9, 95% CI: 1.1-3.1), and exposures to hyperthermia (aOR: 2.3, 95% CI: 1.2-4.3), common cold (aOR: 6.8, 95% CI: 3.6-12.7), and analgesic/antipyretic drugs (aOR: 3.6, 95% CI: 1.3-10.0). Our high rate probably results from exposures to preventable risks, most related to FA, indicating a need for strengthening existing FA-related programs in Mexico.

Síndrome de médula anclada en el periodo neonatal: comunicación de un caso / Neonatal tethered cord syndrome: a case report

El hallazgo de una alteración cutánea en la región dorsal de los recién nacidos constituye un signo infrecuente aunque de gran importancia clínica debido a su posible asociación con disrafismo espinal. El disrafismo espinal oculto es un defecto en el cierre del tubo neural en el que la lesión no se encuentra expuesta al exterior sino cubierta por piel. Su principal complicación es la asociación con el síndrome de médula anclada, que puede causar un daño neurológico irreversible. De ahí la relevancia de un diagnóstico y tratamiento precoces. Presentamos el caso de un neonato varón con disrafismo espinal oculto asociado a médula anclada en el que se realizó un diagnóstico y tratamiento precoces

The finding of a cutaneous alteration in the dorsal region of a newborn is an uncommon sign. It is an important manifestation due to its possible association with spinal dysraphism. Occult spinal dysraphism is a defect in the closure of the neural tube without exposure of the malformation, which is covered by skin. The main complication of occult spinal dysraphism is the association with the tethered cord syndrome that leads to important neurological manifestations which can be irreversible. Because of that, an early diagnosis and treatment must be a priority for clinicians. We present a case of a male newborn with occult spinal dysraphism associated with tethered cord syndrome. In this case an early diagnosis and treatment was successfull

Association between maternal pregestational diabetes mellitus and spina bifida: A population-based case-control study, Finland, 2000-2014.

BACKGROUND: Maternal pregestational diabetes mellitus (PGDM) is a known risk factor for neural tube defects. We examined the association between maternal PGDM and spina bifida in the offspring using PGDM status from medical records in Finland. METHODS: We conducted a nationally representative, multiregistry, population-based case-control study in Finland. Cases were included if they were live or stillborn infants and diagnosed with spina bifida and delivered between years 2000 and 2014 in Finland. Controls were Finnish infants without spina bifida or other major structural birth defects and delivered during the same time period as cases. Clinical and demographic data were obtained by linking multiple national health registers and census. Crude and adjusted odds ratios (ORs) and 95% confidence intervals (CI) for PGDM were estimated using logistic regression analysis. Interaction by maternal obesity was examined. RESULTS: Our study included 181 spina bifida cases (61% isolated) and 876,672 controls. Overall, 2.2% percent of all case, and 0.5% of control mothers, had PGDM during pregnancy. Maternal PGDM was significantly associated with an increased odds of spina bifida (adjusted OR 4.35; 95% CI 1.37, 13.82). A similar association was found in our subanalysis on isolated spina bifida cases (adjusted OR 4.41; 95% CI 1.07, 18.24). There was no significant interaction by maternal obesity. CONCLUSIONS: Maternal PGDM was positively associated with spina bifida in Finland, and maternal obesity did not modify this effect. We lacked information on maternal PGDM for electively terminated and spontaneously aborted cases; results should be interpreted with caution.

Dynamic acetylation profile during mammalian neurulation.

BACKGROUND: Neural tube defects (NTDs) result from failure of neural tube closure during embryogenesis. These severe birth defects of the central nervous system include anencephaly and spina bifida, and affect 0.5-2 per 1,000 pregnancies worldwide in humans. It has been demonstrated that acetylation plays a pivotal role during neural tube closure, as animal models for defective histone acetyltransferase proteins display NTDs. Acetylation represents an important component of the complex network of posttranslational regulatory interactions, suggesting a possible fundamental role during primary neurulation events. This study aimed to assess protein acetylation contribution to early patterning of the central nervous system both in human and murine specimens. METHODS: We used both human and mouse (Cited2 -/- ) samples to analyze the dynamic acetylation of proteins during embryo development through immunohistochemistry, western blot analysis and quantitative polymerase chain reaction. RESULTS: We report the dynamic profile of histone and protein acetylation status during neural tube closure. We also report a rescue effect in an animal model by chemical p53 inhibition. CONCLUSIONS: Our data suggest that the p53-acetylation equilibrium may play a role in primary neurulation in mammals.

Association of interpregnancy change in body mass index and spina bifida.

BACKGROUND: Epidemiologic studies have consistently identified an association between spina bifida and maternal body mass index (BMI). Whether this reflects a causal relationship is unknown. If this association does reflect a causal relationship, the risk of spina bifida should change with changes in maternal BMI. We evaluated the association between spina bifida and maternal change in BMI, assessed using interpregnancy change in BMI (IPC-BMI). METHODS: We used data from the Texas Birth Defects Registry and statewide vital records for 248 spina bifida cases and 2,562 controls (2006-2012) to conduct a case-control study. We used logistic regression to estimate the association between IPC-BMI and spina bifida, with adjustment for potential confounders. RESULTS: When assessed as a continuous variable, IPC-BMI was associated with spina bifida, with a 5% increase in the odds of spina bifida per unit (approximately 6 pounds) increase in BMI (adjusted odds ratios [aOR] = 1.05, 95% CI: 1.02, 1.09). When assessed as a categorical variable, with weight stable women as the referent, the odds of spina bifida were lower in women with any BMI decrease (aOR = 0.73, 95% CI: 0.50, 1.08) and higher in women with an increase of ≥1 BMI units (aOR = 1.17, 95% CI: 0.85, 1.62). CONCLUSIONS: Our findings provide suggestive, although not conclusive, evidence that maternal prepregnancy change in BMI, assessed using IPC-BMI, is associated with spina bifida in the later pregnancy. Additional studies aimed at confirming this association and further strengthening the evidence for a causal relationship between spina bifida and maternal BMI are needed.

Pregnancy outcome following opioid exposure: A cohort study.

INTRODUCTION: Opioids constitute a cornerstone of pain relief treatment. However, opioid safety during pregnancy has not been well established. Recent studies reported an association between in utero opioid exposure and spina bifida. METHODS: In order to further evaluate the association of opioids exposure during pregnancy with adverse pregnancy outcomes, we conducted a large historical cohort by linking four databases: medications dispensations, births, pregnancy terminations for medical reasons and infant hospitalizations during the years of 1999-2009. Confounders that were controlled for included maternal age, ethnicity, maternal diabetes, smoking status, parity, obesity, year and folic acid intake. A secondary analysis for total major malformations and for spina bifida was performed using propensity score matching for first trimester exposure. RESULTS: Of the 101,586 women included in the study, 3003 were dispensed opioids during the first trimester. Intrauterine exposure to opioids was not associated with overall major malformations (adjusted odds ratio (aOR) 0.97, 95% CI 0.83-1.13), cardiovascular malformations (aOR = 0.89, 95% CI 0.70-1.13) other malformations by systems or spina bifida in particular. However, the risk for spina bifida among newborns and abortuses who were exposed to codeine was four times higher than that of the unexposed (aOR = 4.42, 95% CI 1.60-12.23). This association remained significant in a secondary analysis using propensity score matching. Third trimester exposure to opioids was not associated with low birth weight (aOR = 1.08, 95% CI 0.77-1.52), perinatal death (aOR = 1.38, 95% CI 0.64-2.99) and other adverse pregnancy outcomes. CONCLUSIONS: These findings suggest that opioids exposure (as a homogenous group) is not a significant risk factor for overall major malformations. Exposure to codeine during the first trimester was found to be associated with increased risk of spina bifida. However, this finding was based on a small number of cases and need to be verified in future work.

Cirugía prenatal de la espina bífida / Prenatal surgery for spina bifida

No disponible

Melatonin protected against the detrimental effects of microRNA-363 in a rat model of vitamin A-associated congenital spinal deformities: Involvement of Notch signaling.

Congenital spinal deformities are a result of defective somitogenesis and are associated with vitamin A deficiency (VAD). However, the molecular mechanisms of VAD-associated congenital spinal deformities remain largely unknown. Increasing number of studies suggested that microRNAs and melatonin played important roles in the development of congenital spinal deformities. In this study, we showed that the whole-embryo expression of miR-363 was upregulated in VAD rats. Furthermore, we demonstrated that miR-363 inhibited the proliferation and neuronal differentiation of primary cultured NSCs, accompanied by downregulation of Notch1. To this end, melatonin suppressed miR-363 expression and rescued the effects of miR-363 on NSC proliferation and neuronal differentiation together with restoration of Notch signaling. The present study provided new insights into the mechanism of VAD-associated spinal deformities and the therapeutic effect of melatonin that may lead to novel understanding of the molecular mechanisms of congenital spinal deformities.

Understanding how the concentration of neighborhood advantage and disadvantage affects spina bifida risk among births to non-Hispanic white and Hispanic women, Texas, 1999-2014.

BACKGROUND: This is the first study to utilize the index of concentration at the extremes (ICE) to examine risk factors for spina bifida in Texas. The ICE is a useful measure for providing the degree to which residents in a certain area are concentrated into groups at the extremes of disadvantage and privilege. We introduce two novel ICE measures (language and nativity), and three existing ICE measures (race/ethnicity, income, and education), which we applied specifically to Texas residents. METHODS: We used multivariable mixed-model Poisson regression analyses to estimate spina bifida birth prevalence and prevalence ratios among singleton live births in Texas, 1999-2014, for each of our ICE measures. Maternal census tract at delivery was included in the models as a random effect. Analyses were stratified by maternal race/ethnicity (Hispanics and non-Hispanic whites). Live births served as denominators for each category. RESULTS: Among non-Hispanic white women, those in the most disadvantaged versus the advantaged census tract quintile had adjusted relative risk between 1.6 and 8.5 for having a baby affected by spina bifida. However, Hispanic women in the most disadvantaged versus advantaged census tract quintile for four ICE measures had a 33% to 87% lower risk of having an affected pregnancy. CONCLUSIONS: Findings suggest spina bifida risk is associated with neighborhood disadvantage or advantage, and that relationship seems to vary by race-ethnicity. The varied associations between ICE measures and spina bifida by race/ethnicity highlights the importance of using targeted interventions in the prevention of spina bifida.

Genetic variation in biotransformation enzymes, air pollution exposures, and risk of spina bifida.

Spina bifida is a birth defect characterized by incomplete closure of the embryonic neural tube. Genetic factors as well as environmental factors have been observed to influence risks for spina bifida. Few studies have investigated possible gene-environment interactions that could contribute to spina bifida risk. The aim of this study is to examine the interaction between gene variants in biotransformation enzyme pathways and ambient air pollution exposures and risk of spina bifida. We evaluated the role of air pollution exposure during pregnancy and gene variants of biotransformation enzymes from bloodspots and buccal cells in a California population-based case-control (86 cases of spina bifida and 208 non-malformed controls) study. We considered race/ethnicity and folic acid vitamin use as potential effect modifiers and adjusted for those factors and smoking. We observed gene-environment interactions between each of the five pollutants and several gene variants: NO (ABCC2), NO2 (ABCC2, SLC01B1), PM10 (ABCC2, CYP1A1, CYP2B6, CYP2C19, CYP2D6, NAT2, SLC01B1, SLC01B3), PM2.5 (CYP1A1 and CYP1A2). These analyses show positive interactions between air pollution exposure during early pregnancy and gene variants associated with metabolizing enzymes. These exploratory results suggest that some individuals based on their genetic background may be more susceptible to the adverse effects of pollution.

Periconceptional maternal fever, folic acid intake, and the risk for neural tube defects.

PURPOSE: Previous studies have shown an association between maternal fever in early pregnancy and neural tube defects (NTDs) such as spina bifida. Periconceptional folic acid intake has been shown to reduce the risk of these outcomes. METHODS: Using data from the Slone Epidemiology Center Birth Defects Study (1998-2015), we examined the impact of folic acid on the relationship between maternal fever in the periconceptional period (28 days before and after the last menstrual period) and NTDs. Logistic regression models were used to calculate adjusted odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: Mothers of 375 cases and 8247 nonmalformed controls were included. We observed an elevated risk for NTDs for fever in the periconceptional period (OR: 2.4; 95% CI: 1.5-4.0). This association was weaker for mothers who reported consuming the recommended amount of folic acid (≥400 µg per day; OR: 1.8; 95% CI: 0.8-4.0) than mothers with low folic acid intake (<400 µg per day; OR: 4.2; 95% CI: 2.2-8.2). CONCLUSIONS: Our data support an association between maternal periconceptional fever and an increased risk for NTDs and also provide evidence that this association was attenuated for mothers who reported consuming folic acid at recommended levels in the periconceptional period.

Air pollution, neighborhood acculturation factors, and neural tube defects among Hispanic women in California.

BACKGROUND: Neural tube defects (NTDs) are one of the most common types of birth defects. Environmental pollutants and acculturation have been associated with NTDs independently. The potential effect modification of acculturation in the relationship between ambient air pollution and risks of NTDs is not well understood. METHODS: We investigated whether associations between traffic-related air pollutant exposure in early gestation and NTDs, and more specifically spina bifida, were modified by individual and neighborhood acculturation factors among 139 cases and 466 controls born in the San Joaquin Valley of California, 1997 to 2006. Five criteria pollutant exposures in tertiles, two outcomes, and seven neighborhood acculturation factors from the U.S. Census at the block group level were included for a total of 280 investigated associations. Estimates were adjusted for maternal education and multivitamin use in the first 2 months of pregnancy. Additional analyses were stratified by nativity. RESULTS: Increased odds of NTDs were observed for individuals who had high exposures to carbon monoxide, nitrogen oxide, or nitrogen dioxide and lived in neighborhoods that were more acculturated. Conversely, there were increased odds of NTDs for those who had high prenatal exposure to PM10 and lived in neighborhoods that were less acculturated. The results of spina bifida alone were generally stronger in magnitude. When stratified by individual nativity (U.S.- vs. foreign-born), carbon monoxide, nitrogen oxide, and nitrogen dioxide were more strongly associated with NTDs among U.S.-born Hispanic mothers. CONCLUSION: Neighborhood acculturation factors were modifiers of the relationship between air pollution and NTDs in California, though not in a consistent direction for all pollutants. Birth Defects Research 109:403-422, 2017. © 2017 Wiley Periodicals, Inc.

Neural tube closure and embryonic metabolism.

Neural tube closure (NTC) is an embryonic process during formation of the mammalian central nervous system. Disruption of the dynamic, sequential events of NTC can cause neural tube defects (NTD) leading to spina bifida and anencephaly in the newborn. NTC is affected by inherent factors such as genetic mutation or if the mother is exposed to certain environmental factors such as intake of harmful chemicals, maternal infection, irradiation, malnutrition, and inadequate or excessive intake of specific nutrients. Although effects of these stress factors on NTC have been intensively studied, the metabolic state of a normally developing embryo remains unclear. State-of-the art mass spectrometry techniques have enabled detailed study of embryonic metabolite profiles and their distribution within tissues. This approach has demonstrated that glucose metabolism is altered during NTC stages involving chorioallantoic branching. An understanding of embryonic metabolic rewiring would help reveal the etiology of NTD caused by environmental factors.

A systematic review of the risks factors associated with the onset and natural progression of spina bifida.

The purpose of this study was to systematically assess and synthesize the world literature on risk factors for the onset and natural progression of spina bifida, thereby providing a basis for policy makers to identify appropriate risk management measures to mitigate the burden of disease in Canada. Searches of several health literature databases from inception to February 2013 were conducted by a health sciences librarian. A total of three meta-analyses that studied a risk factor for the onset of spina bifida were included. Pooled results showed that paternal exposure to Agent Orange (RR=2.02; 95% CI 1.48-2.74) and maternal obesity prior to pregnancy (OR=2.24; 95% CI 1.86-2.74) each increased the risk of having a child with spina bifida. Paternal exposure to organic solvents was also close to the limit of significance (OR=1.59; 95% CI 0.99-2.56). A total of 63 observational studies, encompassing hundreds of potential risk factors, were included for risk factors for the onset of disease. One meta-analysis and four observational studies examined the impact of genetic risk factors. Only specified mutations in the 5,10-methylenetetrahydrofolate reductase (MTHFR) and dihydrofolate reductase (DHFR) genes were found to be linked to disease onset. One observational study evaluated a risk factor for the natural progression of disease. An extensive number of potential risk factors for the onset of spina bifida have been studied, though most lack sufficient evidence to confirm an association. Currently, strong evidence exists to suggest a causal association for maternal obesity prior to pregnancy, and paternal exposure to Agent Orange.