Application of GIS-Based Spatial Filtering Method for Neural Tube Defects Disease Mapping

This study is to assess the prevalence rates spatial pattern of neural tube defects with geographic information system and spatial filtering technique. A total of 80 infants who diagnosed from neural tube defects in the area being studied between 1998 and 2001 were analyzed. Firstly, the geographic information system （GIS） software ArcGIS was used to map the crude prevalence rates. Secondly, the data were smoothed by the method of spatial filtering. We evaluated that the effect of changes in spatial filtering radius size was assessed by creating maps based on various filtering radius sizes. The 3 miles or larger filtering radius gives better section variability than the 2 and 2.5 miles or smaller ones. The maps produced by the spatial filtering technique indicate that prevalence rates in the villages in the southeastern region are to produce higher prevalence than that in the other regions. The smoothed maps based on Heshun County display a more adequate data representation than the raw prevalence rate map.

Effect of Exposure to Trace Elements in the Soil on the Prevalence of Neural Tube Defects in a High-Risk Area of China

Objective Our 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. Methods We 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. Results Tin, 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. Conclusion As 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.

Advanced glycation end products induce neural tube defects through elevating oxidative stress in mice

Our previous study showed an association between advanced glycation end products （AGEs） and neural tube defects （NTDs）. To understand the molecular mechanisms underlying the effect of AGEs on neural tube development, C57BL/6 female mice were fed for 4 weeks with com- mercial food containing 3% advanced glycation end product bovine serum albumin （AGE-BSA） or 3% bovine serum albumin （BSA） as a control. After mating mice, oxidative stress markers including malondialdehyde and H202 were measured at embryonic day 7.5 （E7.5） of ges- tation, and the level of intracellular reactive oxygen species （ROS） in embryonic cells was determined at E8.5. In addition to evaluating NTDs, an enzyme-linked immunosorbent assay was used to determine the effect of embryonic protein administration on the N-（carboxymethyl） lysine reactivity of acid and carboxyethyl lysine antibodies at E10.5. The results showed a remarkable increase in the incidence of NTDs at El0.5 in embryos of mice fed with AGE-BSA （no hyperglycemia） compared with control mice. Moreover, embryonic protein administration resulted in a noticeable increase in the reactivity of N-（carboxymethyl） lysine and N（ε）-（carboxyethyl） lysine antibodies. Malondialdehyde and H2O2 levels in embryonic cells were increased at E7.5, followed by increased intracellular ROS levels at E8.5. Vitamin E supplementation could partially recover these phenomena. Collectively, these results suggest that AGE-BSA could induce NTDs in the absence of hyperglycemia by an underlying mechanism that is at least partially associated with its capacity to increase embryonic oxidative stress levels.

Unusual Patterns of Neural Tube Defects in a High Risk Region of Northern China

Objective To study the prevalence of different types of neural tube defects （NTDs） in Luliang Prefecture, Shanxi province, where the prevalence of NTDs is unusually high and the correlation between NTDs prevalence and patterns. Methods A surveillance population-based birth defects was performed in Luliang Prefecture, Shanxi province. Results The results of our study showed that the prevalence of NTDs was 2-fold higher in Luliang Prefecture than in other areas of Shanxi province. Unusual patterns of NTDs were found, however, multiple NTDs were relatively common in Luliang Prefecture, accounting for over 13% of all NTDs cases in China. Conclusion The prevalence of NTDs is associated with its patterns.

Cell cycle-related genes p57kip2, Cdk5 and Spin in the pathogenesis of neural tube defects

In the field of developmental neurobiology, accurate and ordered regulation of the cell cycle and apoptosis are crucial factors contributing to the normal formation of the neural tube. Preliminary studies identified several genes involved in the development of neural tube defects. In this study, we established a model of developmental neural tube defects by administration of retinoic acid to pregnant rats. Gene chip hybridization analysis showed that genes related to the cell cycle and apoptosis, signal transduction, transcription and translation regulation, energy and metabolism, heat shock, and matrix and cytoskeletal proteins were all involved in the formation of developmental neural tube defects. Among these, cell cycle-related genes were predominant. Retinoic acid treat-ment caused differential expression of three cell cycle-related genes p57kip2, Cdk5 and Spin, the expression levels of which were downregulated by retinoic acid and upregulated during normal neural tube formation. The results of this study indicate that cell cycle-related genes play an im-portant role in the formation of neural tube defects. P57kip2, Cdk5 and Spin may be critical genes in the pathogenesis of neural tube defects.

Methylmalonic Acid in Amniotic Fluid and Maternal Urine as a Marker for Neural Tube Defects

To evaluate the implication of methymalonic acid (MMA) in the early diagnosis of neural tube defects (NTD), a quantitative assay for MMA was established by using gas chromatography-mass spectrometry with stable isotope of MMA as an internal standard. Amniotic fluid and maternal urine MMA concentration, maternal serum folate, red blood cell folate and vitamin B 12 levels were measured in the middle term of NTD-affected and normal pregnancies. Amniotic fluid and maternal urine MMA concentrations in the middle term of NTD affected pregnancies (1.4±0.9 μmol/L, and 22.1±12.6 nmol/μmol creatinine) were significantly higher than that of normal pregnancies (1.0±0.4μmol/L, and 2.5±1.1 nmol/μmol creatinine). There was no significant difference between normal and NTD pregnancies for serum folate, red blood cell folate and vitamin B 12 levels. The results suggested that MMAs in amniotic fluid and maternal urine are sensitive markers for early diagnosis of NTD. Vitamin B 12 is an active cofactor involved in the remethylation of homocycteine and its deficiency is an independent risk factor for NTD. MMA is a specific and sensitive marker for intracellular vitamin B 12 deficiency. This study suggests that it is necessary to monitor the vitamin B 12 deficiency and advocates vitamin B 12 supplementation with folate prevention program.

Polymorphisms of the maternal Slug gene in fetal neural tube defects in a Chinese population

Several studies have demonstrated that Slug,which encodes a zinc finger of the Snail family of transcription factors,is a potential risk factor for neural tube defects.Neural tube defects tend to occur with a high rate in Shanxi province,China.The present case-control study investigated genotypic distributions and allele frequencies of Slug C1548A polymorphisms in DNA samples from59 women with a history of neural tube defect pregnancies and 73 controls during the same period from Shanxi Province,China.Results demonstrated that women with a history of neural tube defect pregnancies had significantly greater genotypic distributions of Slug AA genotypes and A allele frequencies compared with controls,and A allele Slug C1548A was a risk factor for neural tube defects（odds ratio = 3.444;95% confidence interval;2.021-5.868,P 〈 0.05）.Three-dimensional structure prediction revealed that Slug C1548A resulted in transition of aspartic acid into glutamate at position 119.This indicated that these mutations could lead to damaged protein structure and function.These findings suggest that Slug C1548A gene polymorphism is closely related to neural tube defects in a population of Han Chinese origin from Shanxi Province,China

An epidemiologic study of mitochondrial membrane transporter protein gene polymorphism and risk factors for neural tube defects in Shanxi, China

The present study involved a questionnaire survey of 156 mothers that gave birth to children with neural tube defects or had a history of pregnancy resulting in children with neural tube defects （case group） and 156 control mothers with concurrent healthy children （control group） as well as detection of mitochondrial membrane transporter protein gene [uncoupling protein 2 （UCP2）] polymorphism. The maternal UCP2 3＇ untranslated region （UTR） D/D genotype and D allele frequency were significantly higher in the case group compared with the control group （odds ratio （OR） 3.233; 95% confidence interval （C/） 1.103 9.476; P= 0.040; OR： 3.484; 95% CI： for neural tube defects 2.109 5.753; P 〈 0.001）. Univariate and multivariate logistic regression analysis of risk factors for neural tube defects showed that a matemal UCP2 3＇ UTR D/D genotype was negatively interacted with the mothers＇ consumption of frequent fresh fruit and vegetables （S = 0.007）, positively interacted with the mothers＇ frequency of germinated potato consumption （S = 2.15） and positively interacted with the mothers＇ body mass index （S = 3.50）. These findings suggest that maternal UCP2 3＇ UTR gene polymorphism, pregnancy time, consumption of germinated potatoes and body mass index are associated with an increased risk for neural tube defects in children from mothers living in Shanxi province, China. Moreover, there is an apparent gene-environment interaction involved in the development of neural tube defects in offspring.

Gene expression in retinoic acid-induced neural tube defects A cDNA microarray analysis

BACKGROUND： Neural tube defects can be induced by abnormal factors in vivo or in vitro during development. However, the molecular mechanisms of neural tube defect induction, and the related gene expression and regulation are still unknown. OBJECTIVE： To compare the differences in gene expression between normal embryos and those with neural tube defects. DESIGN, TIME AND SETTING： A neural development study was performed at the Department of Neurobiology, Third Military Medical University of Chinese PLA between January 2006 and October 2007. MATERIALS： Among 120 adult Kunming mice, 60 pregnant mice were randomly and evenly divided into a retinoic acid group （n = 30） and a normal control group （n =30）. The retinoic acid was produced by Sigma, USA, the gene microarray by the Amersham Pharmacia Company, Hong Kong, and the gene sequence was provided by the Incyte database, USA. METHODS： Retinoic acid was administered to prepare models of neural tube defects, and corn oil was similarly administered to the normal control group. Total RNA was extracted from embryonic tissue of the two groups using a Trizol kit, and a cDNA microarray containing 1 100 known genes was used to compare differences in gene expression between the normal control group and the retinoic acid group on embryonic （E） day 10.5 and 11.5. Several differentially expressed genes were randomly selected from the two groups for Northern blotting, to verify the results of the cDNA microarray. MAIN OUTCOME MEASURES： Morphological changes and differential gene expression between the normal control group and the retinoic acid group. RESULTS： Anatomical microscopy demonstrated that an intact closure of the brain was formed in the normal mouse embryos by days E10.5 and E11.5. The cerebral appearance was full and smooth, and the surface of the spine was intact. However, in the retinoic acid group on days E10.5 and E11.5, there were more dead embryos. Morphological malformations typically included non-closure at the top of the cranium and abnormal changes of the metencephalon and face. cDNA microarray analysis suggested that the changes in expression of seven different genes were similar on both days E10.5 and E11.5. These were downregulation of NekT, Igfbp5, Zw10, Csf3r, Psmc6 and Rb 1, and upregulation of Apoa-4. This study also indicated that Cdk5 expression was downregulated in the retinoic acid group on day E11.5. The results of the cDNA microarray analysis were partly confirmed by Northern blotting. CONCLUSION： Cdk5, Nek7, Igfbp5, Zw10, Csf3r, Psmc6, Rb1 and Apoa-4 may be key factors in retinoic acid-induced neural tube defects.

Study of A1298C MTHFR Gene Polymorphism as a Risk Factor for Neural Tube Defects in the Eastern Algerian Population

Background: As C677T mutation, A1298C mutation in methylene tetrahydrofolate reductase (MTHFR) gene results in a decreased MTHFR activity but to a less extent, it is known as a risk factor of predisposition to human neural tube defects (NTDs), in some populations. Our objective was therefore to study, for the first time in Algerian population, if A1298C polymorphism confers risk for the occurrence of this abnormality. We have examined the distribution of the genotype and the allele frequencies of A1298C mutation, and also their influence on plasma homocysteine (Hcy) concentration. Patients and Methods: We studied this polymorphism in 38 mothers of NTD cases and 67 control individuals of an eastern Algerian population. The mutation was determined by polymerase chain reaction-restriction fragment length polymorphism analysis (PCR/RFLP). Plasma homocysteine concentration was analyzed using an automated chemiluminescence method. Results: No signi?cant association could be observed between allele and genotypes frequencies of A1298C MTHFR gene polymorphism and NTDs risk. However, we could observe that A1298C polymorphism affects homocysteine metabolism in mothers of NTD cases leading to homocysteine concentration values higher in AA genotype and lower in AC/CC genotypes (15.29 ± 11.8 μmol/l vs. 8.63 ± 3.83 μmol/l, p < 0.05). Conclusion: Data indicate that A1298C MTHFR gene polymorphism might be a risk factor by affecting homocysteine metabolism in mothers of Algerian children with NTDs.

Prevention of neural tube defects with folic acid: The Chinese experience

Neural tube defects(NTDs) are a group of congenital malformations of the central nervous system that are caused by the closure failure of the embryonic neural tube by the 28 th day of conception. Anencephaly and spina bifida are the two major subtypes. Fetuses with anencephaly are often stillborn or electively aborted due to prenatal diagnosis, or they die shortly after birth. Most infants with spina bifida are live-born and, with proper surgical treatment, can survive into adulthood. However, these children often have life-long physical disabilities. China has one of the highest prevalence of NTDs in the world. Inadequate dietary folate intake is believed to be the main cause of the cluster. Unlike many other countries that use staple fortification with folic acid as the public health strategy to prevent NTDs, the Chinese government provides all women who have a rural household registration and who plan to become pregnant with folic acid supplements, free of charge, through a nation-wide program started in 2009. Two to three years after the initiation of the program, the folic acid supplementation rate increased to 85% in the areas of the highest NTD prevalence. The mean plasma folate level of women during early and mid-pregnancy doubled the level before the program was introduced. However, most women began taking folic acid supplements when they knew that they were pregnant. This is too late for the protection of the embryonic neural tube. In a postprogram survey of the women who reported folic acid supplementation, less than a quarter of the women began taking supplements prior to pregnancy, indicating that the remaining three quarters of the fetuses remained unprotected during the time of neural tube formation. Therefore, staple food fortification with folic acid should be considered as a priority in the prevention of NTDs.

Bayesian mapping of neural tube defects prevalence in Heshun County, Shanxi Province, China during 1998～2001

Objective: To estimate the prevalence rates of neural tube defects (NTDs) in Heshun County, Shanxi Province, China by Bayesian smoothing technique. Methods: A total of 80 infants in the study area who were diagnosed with NTDs were analyzed. Two mapping techniques were then used. Firstly, the GIS software ArcGIS was used to map the crude prevalence rates. Secondly, the data were smoothed by the method of empirical Bayes estimation. Results: The classical statistical approach produced an extremely dishomogeneous map, while the Bayesian map was much smoother and more interpretable. The maps produced by the Bayesian technique indicate the tendency of villages in the southeastern region to produce higher prevalence or risk values. Conclusions: The Bayesian smoothing technique addresses the issue of heterogeneity in the population at risk and it is therefore recommended for use in explorative mapping of birth defects. This approach provides procedures to identify spatial health risk levels and assists in generating hypothesis that will be investigated in further detail.

Association of RFC-1 80A→G and MTHFR 677C→T polymorphisms with neural tube defects in Ukrainian population

【Objective】To evaluate the roles of 80A→G polymorphism of RFC-1 gene encoding the reduced folate carrier protein and 677C→T polymorphism of 5,10-methylenetetrahydrofolate reductase gene(MTHFR)in neural tube defects(NTD)risk in Ukrainian population.【Methods】The folate status,homocysteine levels and genotypes were assessed in 42 mothers of fetuses with spina bifida,anencephaly and encephalocele with the age of 19-40 years.Serum folate and plasma homocysteine levels were estimated using chemiluminescence technology.DNA was isolated from peripheral leukocytes obtained from blood using standard procedures.The presence of the RFC-1 80A→G polymorphism was investigated using polymerase chain reaction(PCR).Real time PCR was used to detect the presence of the 677C→T mutation in the MTHFR gene.【Results】Genotype frequencies for RFC-1 80A→G in NTD group were:homozygous wild type in 9(21.4%),heterozygous type in16(38.1%)women;17(40.5%)women surveyed were found homozygous for the mutant allele genotype of RFC-1(GG).Homozygous for the indicated mutation was found in 57.1%of women with fetal anencephaly in the past history and 29.6%of women with spina bifida fetuses.Allelic frequency in this group of women for allele A was 40.5%(34),for allele G was 59.5%(50).Among women with 80A/A genotype of RFC-1 gene reduced levels of serum folic acid were noticed only in 6(35.5%),but hyperhomocysteinemia was found in 10(58.8%)women.【Conclusion】80G→A polymorphism of RFC-1 gene is a potential genetic factor in the formation of fetus NTD in women of South Ukraine.

Pattern and Management of Neural Tube Defect in Cameroon

Objectives: The aim of study was to determine the pattern and management of neural tube defects (NTD). Methodology: It was a hospital based descriptive cross-sectional retrospective study on patients who consulted and/or were admitted at the Douala General hospital for neural tube defects from January 2005 to April 2015. Results: A total of forty-nine (49) patients were enrolled. Males constituted 59.8% and females 40.2% giving a sex ratio of 1.5 in favour of males. Most of the parents of the patients (71.5%) had a low socio-economic status. Myelomeningocele was the most common type (80.4%) followed by 17.4% cases of meningocele and 2.2% cases of lipomeningocele. Three cases (3) of encephaloceles were seen during this period. The commonest site of these defects was the lumbosacral region (47.8%). Other sites included lumbar (19;41.3%), sacral (3;6.5%) and thoracolumbar (2;4.3%) ones. About half of the patients (24;48.9%) presented with ruptured lesions. Hydrocephalus was also recorded in 65.3% of patients. Talipes equinovarus and talipes calcaneovalgus were the most common associated orthopedic birth defects found. Surgical closure was done for 44 (89.9%) patients. Ventriculoperitoneal shunting was done in 78.1% of those who presented with hydrocephalus. Post-operative complications were more frequent in patients with ruptured lesions (P = 0.001). The most common post-operative complications were wound infections (22;44.9%) and wound dehiscence (20;40.8%). Conclusion: Lumbosacral Myelomeningocele was the most common type of NTD in our region. Low socio-economic status was a common risk factor.

PSO/ACO Algorithm-based Risk Assessment of Human Neural Tube Defects in Heshun County,China

Abstract Objective To develop a new technique for assessing the risk of birth defects, which are a major cause of infant mortality and disability in many parts of the world. Methods The region of interest in this study was Heshun County, the county in China with the highest rate of neural tube defects （NTDs）. A hybrid particle swarm optimization/ant colony optimization （PSO/ACO） algorithm was used to quantify the probability of NTDs occurring at villages with no births. The hybrid PSO/ACO algorithm is a form of artificial intelligence adapted for hierarchical classification. It is a powerful technique for modeling complex problems involving impacts of causes. Results The algorithm was easy to apply, with the accuracy of the results being 69.5%＋7.02% at the 95% confidence level. Conclusion The proposed method is simple to apply, has acceptable fault tolerance, and greatly enhances the accuracy of calculations.

Spatiotemporal expression of leukemia inhibitory factor receptor protein during neural tube development in embryos with neural tube defects

Leukemia inhibitory factor receptor(LIFR),as a neuroregulatory cytokine receptor,generally shows a neuroprotective effect in central nervous system injuries.In this study,to understand the effect of LIFR on pathogenesis of neural tube defects,we explored spatiotemporal expression of LIFR at different stages of fetal development in normal and neural tube defect embryos.Spina bifida aperta was induced with all-trans retinoic acid on embryonic day 10 in rats,and the spatiotemporal expression of LIFR was investigated in spina bifida aperta rats and healthy rats from embryonic day 11 to 17.Real time-polymerase chain reaction and western blot assay were used to examine mRNA and protein expression of LIFR in healthy control and neural tube defect embryos.Results of the animal experiment demonstrated that expression of LIFR protein and mRNA in the spinal cords of normal rat embryos increased with embryonic development.LIFR was significantly downregulated in the spinal cords of spina bifida aperta rats compared with healthy rats from embryonic days 11 to 17.Immunohistochemical staining showed that the expression of LIFR in placenta and spinal cord in spina bifida aperta rat embryos was decreased compared with that in control embryos at embryonic day 15.Results from human embryo specimens showed that LIFR mRNA expression was significantly down-regulated in spinal cords of human fetuses with neural tube defects compared with normal controls at a gestational age of 24 to 33 weeks.The results were consistent with the down-regulation of LIFR in the animal experiments.Our study revealed spatiotemporal changes in expression of LIFR during embryonic neurulation.Thus,LIFR might play a specific role in neural tube development.All animal and human experimental procedures were approved by the Medical Ethics Committee of Shengjing Hospital of China Medical University,China(approval No.2016PS106K)on February 25,2016.

Prevalence of Neural Tube Defects: Moroccan Study 2008-2011

Background: Neural tube defects have a considerable importance because they can be prevented by supplementing Folic acid & Vitamin B12 during periconceptional period and fortification of staple foods. In Morocco, the Ministry of Health launched a national program for fortification of flour with folic acid. Our goal should be to evaluate the prevalence of neural tube defects after fortification. Description: This is a retrospective descriptive at the National Reference Centre for Nutrition and Neonatology of the Children’s Hospital of Rabat over 4 years. Data were identified from the registry of congenital malformations held at the perinatology unit. Results: During the 4 years, 674 congenital malformations were identified. The neural tube defects NTDs account for 11.9%. Their annual prevalence decreased significantly from 21.78 in 2008 to 12.1 per 10,000 total births in 2011. The most common form was anencephaly (60%). Neural tube defects were isolated in 85% of cases and associated with other malformations in 15% of cases. 49.4% of infants with neural tube defects were female and 50.6% were male. Perinatal mortality in newborns with neural tube defects was 63.8% versus 25.2% in malformed newborns without neural tube defects. Conclusions: The neural tube defects seem to be common in our context. Permanent epidemiological surveillance is needed to determine the true prevalence at the national as well as its temporal trends level.

Interaction between maternal 5,10-methylenetetrahydrofolate reductase C677T and methionine synthase A2756G gene variants to increase the risk of fetal neural tube defects in a Shanxi Han population

Background The 5,10-methylenetetrahydrofolate reductase （MTHFR） and methionine synthase （MS） are attractive candidates for screening for risk of neural tube defects （NTDs）. The aim of the current study was to investigate maternal MTHFR and MS polymorphisms and the interaction between them and their influence on children with NTDs in the Shanxi Province of northern China. Methods Fifty-one mothers who previously had children with NTDs constituted the case group and 51 age-matched mothers with children that were unaffected by any birth defects constituted the control group. All subjects were genotyped for MTHFR C677T and MS A2756G polymorphisms. SPSS 11.5 software package was used for all analyses. Results There was a significant difference for MTHFR genotype distribution for one site （C677T） between the case and control groups. The T allele frequencies were significantly higher in the case group than in the control group （55.9% vs. 35.3%, P 〈0.05）. A lack of association was observed for the MS A2756G polymorphism. There was an interaction between the maternal MTHFR C677T genotype and MS A2756G genotype. Conclusion Genetic interaction between MTHFR and MS genes raises the probability of neural tube defects.

Maternal periconceptional consumption of pickled vegetables and risk of neural tube defects in offspring

Background Maternal exposure to nitrate, nitrite, and N-nitroso compounds from drinking water or diet has been associated with an increased risk of neural tube defects （NTDs） in some studies. Pickled vegetables contain relatively large amounts of nitrite and N-nitroso compounds. We examined the association between maternal periconceptional consumption of pickled vegetables and NTDs in Shanxi Province of northern China. Methods Data were derived from a population based case-control study of major external birth defects in four counties of $hanxi Province. Participants included 519 NTDs cases identified between 2003 and 2007 and 694 healthy controls. Exposure information was collected within 1 week after delivery. Multivariable non-conditioanal Logistic regression model was used to estimate the adjusted odds ratio （OR） controlling for potential confounding variables.

CSF-Based Analysis for Identification of Potential Serum Biomarkers of Neural Tube Defects

The protein composition of cerebrospinal fluid（CSF） in neural tube defects（NTDs） remains unknown. We investigated the protein composition of CSF from 9 infants with NTDs using isobaric tags for relative and absolute quantitation（iTRAQ）. We identified 568 proteins in the CSF of infants with spina bifida, which is the most common type of NTD. Among these, 18 proteins were associated with neural tube closure in the CSF during human embryonic neurulation and 5 were involved in NTDs. Based on these results, an animal model was further utilized to investigate early serum biomarkers for NTDs.We found that the myristoylated alanine-rich C-kinase substrate, Kunitz-type protease inhibitor 2, andapolipoprotein B-100 protein levels were decreased in both embryos and the sera of pregnant Sprague-Dawley rats carrying embryos with NTDs. CSF proteins may be useful in the discovery of potential serum biomarkers for NTDs.