Regioselective Brønsted acid catalyzed ring opening of aziridines by phenols and thiophenols; a gateway to access functionalized indolines, indoles, benzothiazines, dihydrobenzo-thiazines, benzo-oxazines and benzochromenes.

Brønsted acid catalyzed regioselective ring opening of aziridines by phenols and thiophenols have been reported. Involvement of a series of aziridines with a range of phenols and thiophenols offer the generality of the reported protocol. Completion of the reaction at room temperature within very short time brings the uniqueness of the developed technique. To emphasis on the application of the developed methodology, the products have been used for the further synthesis of a range of useful and novel heterocyclic molecules such as indolines, indoles, benzothiazines, dihydrobenzothiazines, benzo-oxazines and benzochromenes.

Brønsted acid-catalyzed regioselective ring opening of 2H-azirines by 2-mercaptopyridines and related heterocycles; one pot access to imidazo[1,2-a]pyridines and imidazo[2,1-b]thiazoles.

A catalytic and versatile synthetic method for the synthesis of imidazo[1,2-a]pyridines has been developed. Brønsted acid-catalysis plays a major role in the regioselective ring opening of 2H-azirines. Nucleophilic attack via the N-centre of mercaptopyridines and their analogues, followed by cyclisation by cleaving the C-S bond, allowed a library of imidazo[1,2-a]pyridines and related heterocycles to be built. The reaction protocol has been applied to various 2H-azirines, 2-mercaptopyridines, and thiazole-2-thiols, illustrating the generality of reaction conditions. The practical applications include the synthesis of pharmaceuticals, such as anti-tumor agents. This study introduces a novel approach to the synthesis of functional molecules with extensive potential.

Obesity Differs from Diabetes Mellitus in Antibody and T Cell Responses Post COVID-19 Recovery.

Obesity and type 2 diabetes (DM) are risk factors for severe COVID-19 outcomes, which disproportionately affect South Asian populations. This study aims to investigate the humoral and cellular immune responses to SARS-CoV-2 in adult COVID-19 survivors with obesity and DM in Bangladesh. In this cross-sectional study, SARS-CoV-2-specific antibody and T cell responses were investigated in 63 healthy and 75 PCR-confirmed COVID-19 recovered individuals in Bangladesh, during the pre-vaccination first wave of the COVID-19 pandemic in 2020. In COVID-19 survivors, SARS-CoV-2 infection induced robust antibody and T cell responses, which correlated with disease severity. After adjusting for age, sex, DM status, disease severity, and time since onset of symptoms, obesity was associated with decreased neutralising antibody titers, and increased SARS-CoV-2 spike-specific IFN-γ response along with increased proliferation and IL-2 production by CD8+ T cells. In contrast, DM was not associated with SARS-CoV-2-specific antibody and T cell responses after adjustment for obesity and other confounders. Obesity is associated with lower neutralising antibody levels and higher T cell responses to SARS-CoV-2 post COVID-19 recovery, while antibody or T cell responses remain unaltered in DM.

Pain/Stress, Mitochondrial Dysfunction and Neurodevelopment in Preterm Infants.

Introduction Preterm infants experience tremendous early life pain/stress during their neonatal intensive care unit (NICU) hospitalization, which impacts their neurodevelopmental outcomes. Mitochondrial function/dysfunction may interface between perinatal stress events and neurodevelopment. Nevertheless, the specific proteins or pathways linking mitochondrial functions to pain-induced neurodevelopmental outcomes in infants are remain unidentified. Our study aims to investigate the associations among pain/stress, proteins associated with mitochondrial function/dysfunction, and neurobehavioral responses in preterm infants. Methods We conducted a prospective cohort study, enrolling 33 preterm infants between September 2017 and July 2022 at two affiliated NICUs located in Hartford and Farmington, CT. NICU Network Neurobehavioral Scale (NNNS) datasets were evaluated to explore potential association with neurobehavioral outcomes. The daily pain/stress experienced by infant's during their NICU stay was documented. At 36-38 weeks post-menstrual age (PMA), neurobehavioral outcomes were evaluated using the NNNS and buccal swabs were collected for further analysis. Mass spectrometry-based proteomics was conducted on epithelial cells obtained from buccal swabs to evaluate protein expression level. Lasso statistical methods were conducted to study the association between protein abundance and infants' NNNS summary scores. Multiple linear regression and Gene Ontology (GO) enrichment analyses were performed to examine how clinical characteristics and neurodevelopmental outcomes may be associated with protein levels and underlying molecular pathways. Results During NICU hospitalization, preterm premature rupture of membrane (PPROM) were negatively associated with neurobehavioral outcomes. The protein functions including leptin receptor binding activity, glutathione disulfide oxidoreductase activity and response to oxidative stress, lipid metabolism, phosphate and proton transmembrane transporter activity were negatively associated with neurobehavioral outcomes, in the contrast, cytoskeletal regulation, epithelial barrier and protection function were found to be associated with the optimal neurodevelopmental outcomes. In addition, mitochondrial function associated proteins including SPRR2A, PAIP1, S100A3, MT-CO2, PiC, GLRX, PHB2, and BNIPL-2 demonstrated positive association with favorable neurodevelopmental outcomes, while proteins of ABLIM1, UNC45A, Keratins, MUC1, and CYB5B showed positive association with adverse neurodevelopmental outcomes. Conclusion Mitochondrial function-related proteins were observed to be associated with early life pain/stress and neurodevelopmental outcomes in infants. Large-scale studies with longitudinal datasets are warranted. Buccal proteins could be used to predict potential neurobehavioral outcomes.

Methyltrifluoromethanesulfonate Catalyst in Direct Nucleophilic Substitution of Alcohols; One-Pot Synthesis of 4H-Chromene Derivatives.

The catalytic activity of methyltrifluoromethanesulfonate (MeOTf) has been explored toward direct nucleophilic substitution of the hydroxyl group of nonmanipulated alcohols such as benzylic, allylic, propargylic, and tertiary alcohols with a wide range of uncharged nucleophiles such as 1,3-dicarbonyl compounds, amides, alkynes, and indoles to generate functionalized 1,3-dicarbonyl compounds, amides, alkynes, and indoles, respectively. Thus, the present protocol defines an alternate pathway to construct new C-C, C-N, and C-O bonds with the formation of water as the byproduct under mild conditions without any acids or metals. A completely different mechanism was established through several control experiments to explain the reaction methodology. As an application of the reported protocol, 1H-indene derivatives have been synthesized in one pot when benzylic alcohols were subjected to react with internal alkynes. The scope of the reaction has been further extended toward a tandem benzylation-cyclization-dehydration of 1,3-dicarbonyl compounds with 2-hydroxybenzyl alcohols, which furnish biologically important 4H-chromene derivatives.

Regioselective Transition Metal-Free Catalytic Ring Opening of 2H-Azirines by Phenols and Naphthols; One-Pot Access to Benzo- and Naphthofurans.

Benzofuran and naphthofuran derivatives are synthesized from readily available phenols and naphthols. Regioselective ring openings of 2H-azirine followed by in situ aromatization using a catalytic amount of Brønsted acid have established the novelty of the methodology. The involvement of a series of 2H-azirines with a variety of phenols, 1-naphthols, and 2-naphthols showed the generality of the protocol. In-depth density functional theory calculations revealed the reaction mechanism with the energies of the intermediates and transition states of a model reaction. An alternate pathway of the mechanism has also been proposed with computer modeling.

Replica symmetry breaking in a colloidal plasmonic random laser with gold-coated triangular silver nanostructures.

Plasmonic random lasers have drawn significant attention recently due to their versatility, low threshold, and the possibility of achieving tunable and coherent/incoherent outputs. However, in this Letter, the phenomenon of replica symmetry breaking is reported in intensity fluctuations of a rarely used colloidal plasmonic random laser (RL) illumination. Triangular nanosilver scatter particles produced incoherent RL action when used in a dimethylformamide (DMF) environment in a Rhodamine-6G gain medium. The use of gold-coated triangular nanosilver as the scatterer in place of triangular nanosilver offered a dual contribution of scattering and lower photo-reabsorption, which caused a reduction in the lasing threshold energy of 39% compared to that obtained with the latter. Further, due to its long-term photostability and chemical properties, a phase transition from the photonic paramagnetic to the glassy phase is observed experimentally in the RL system used. Interestingly, the transition occurs at approximately the lasing threshold value, which is a consequence of stronger correlation of modal behaviors at high input pump energies.

Accumulation of Biological and Behavioral Data of Female Sex Workers Using Respondent-Driven Sampling: Protocol for a Systematic Review.

BACKGROUND: Respondent-driven sampling (RDS) is a nonprobability sampling technique that allows the extrapolation of its outcome to the target population. This approach is typically used to overcome the difficulties in studying hidden or difficult-to-reach groups. OBJECTIVE: The purpose of this protocol is to generate a systematic review on the accumulation of biological and behavioral data of female sex workers (FSWs) through different surveys that use the RDS method from around the world in the near future. The future systematic review will discuss the initiation, actualization, and problems of RDS during the accumulation of biological and behavioral data of FSWs through surveys from around the world. METHODS: The behavior and biological data of FSWs will be extracted from peer-reviewed studies published between 2010 and 2022 and that are acquired through RDS. Using PubMed, Google Scholar, the Cochrane database, Scopus, Science Direct, and the Global Health network, all papers that are available will be obtained using the search phrases "respondent-driven" and "Female Sex Workers" OR "FSW" OR "sex workers" OR "SW." According to STROBE-RDS (Strengthening the Reporting of Observational Studies in Epidemiology for Respondent-Driven Sampling) criteria, the data will be retrieved through a data extraction form and will be organized using World Health Organization classifications of areas. The Newcastle-Ottawa Quality Assessment Scale will be used to measure bias risk and overall study quality. RESULTS: The future systematic review that will be generated from this protocol will offer evidence for or against the claim that using the RDS technique to recruit participants from "hidden" or "hard-to-reach" populations is the best strategy. The results will be disseminated through a peer-reviewed publication. Data collection started on April 1, 2023, and the systematic review is expected to be published by December 15, 2023. CONCLUSIONS: A minimum set of parameters for specific methodological, analytical, and testing procedures, including RDS methods to evaluate the overall quality of any RDS survey, will be provided by the future systematic review, in accordance with this protocol, to assist researchers, policy makers, and service providers in improving RDS methods for the surveillance of any key population. TRIAL REGISTRATION: PROSPERO CRD42022346470; https://tinyurl.com/54xe2s3k. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/43722.

Sexually transmitted infections among key populations in India: A protocol for systematic review.

BACKGROUND: Sexually transmitted infections (STIs) are one of the leading causes of health, and economic burdens in the developing world, leading to considerable morbidity, mortality, and stigma. The incidence and prevalence of the four curable STIs viz. syphilis, gonorrhoea, chlamydia, and trichomoniasis vary remarkably across different geographical locations. In India, the prevalence of four curable STI among general populations is in between 0 to 3.9 percent. However, it is assumed that STI prevalence is much higher among subpopulations practicing high-risk behaviour. Like men who have sex with men (MSM), transgender (TG), injecting drug users (IDU), and female sex workers (FSW). OBJECTIVES: In the present circumstances, a systematic review is necessary to integrate the available data from previously published peer-reviewed articles and published reports from several competent authorities to provide the prevalence and geographical distribution of the four curable STIs among the key population of India. METHODS: All available articles will be retrieved from PubMed, Google Scholar, Cochrane database, Scopus, Science Direct, and the Global Health network using the appropriate search terms. The data will be extracted through data extraction form as per PICOS (population, intervention, comparison, outcome, study design) framework. Risk of bias and quality assessment will be performed according to the situation with the help of available conventional protocol. DISCUSSION: The future systematic review, generated from the present protocol, may provide evidence of the prevalence and geographical distribution of the four curable STIs among the key population of India. We hope that the findings of the future systematic review will strengthen the existing surveillance system in India, to determine the above-mention STIs prevalence among key populations in India. Protocol registration number: International Prospective Register for Systematic Reviews (PROSPERO) number CRD42022346470.

Vertical Transmission Rate of Human Immunodeficiency Virus Exposed Twin Pregnancies and Associated Factors in West Bengal, India: a Retrospective Cohort Study.

Twin pregnancies are often associated with adverse obstetric outcomes. The mother-to-child transmission of the human immunodeficiency virus (HIV) in twin pregnancies has been less explored. Therefore, the present study aimed to determine the risk of vertical transmission of HIV in HIV-exposed twin pregnancies compared with that of singleton pregnancies and to explore the associated factors. We conducted a retrospective cohort study involving 348 HIV-exposed babies (58 twins and 290 singletons) through a systematic sampling from the program database of West Bengal, India, from April 2016 to March 2021. HIV vertical transmission rates were compared between single and twin live births. The effects of factors such as maternal age, timing of maternal HIV diagnosis, duration of antiretroviral treatment, mode of delivery, birth weight, and the sex of the baby were determined. The HIV transmission rate for twin pregnancies (15.5%) was significantly higher than that for single live births (5.5%) (adjusted odds ratio [OR] = 3.38 [1.17-9.69]). Among twin deliveries, maternal HIV diagnosis during the intrapartum and postpartum period was associated with HIV transmission (crude OR = 11.0, [2.2-54.9]). Perinatal HIV transmission is more common in twin pregnancies and is associated with the time of detection of maternal HIV. Therefore, early HIV detection and additional antiretroviral regimens should be considered for twin pregnancies.

Syndemic effect of COVID-19 outbreak on HIV care delivery around the globe: A systematic review using narrative synthesis.

Background: The burden of the COVID-19 pandemic on healthcare systems worldwide has been compromising the progress made in the fight against HIV. This paper aims to determine how the COVID-19 pandemic has impacted HIV comprehensive care service delivery globally as well as to consolidate the evidence and recommendations that may be useful in averting future crisis. Methods: This review adheres to PRISMA guidelines. PubMed, DOAJ, Science Direct and other sources like Google Scholar and citations from included studies were searched methodically to locate studies evaluating the effects of COVID on services for HIV care. The NIH and JBI quality assessment tools were used for the quality assessment of individual studies. Results: In the present review 31 eligible studies were included and the impact on HIV care cascade were summarised under six themes: Lab services, Treatment and allied services, Counselling services, Outreach services, Psycho-social impact and Implementation of sustainable strategies. The studies also presented many innovative alternatives which were lucidly highlighted in the present article. Conclusion: Current evidence depicts multiple factors are responsible for the interruption of HIV care service delivery during the pandemic, especially in low resources settings. The prospective, alternative solutions that have been used to circumvent the threat have also been addressed in this review, in addition to the negative aspects that have been observed. Transition with new innovative, sustainable care paradigms may prove to be the building blocks in removing HIV-AIDS as a public health threat. Registration: Open Science Framework (DOI: 10.17605/OSF.IO/74GHM).

Is Serum Creatine Phosphokinase Level Useful to Predict the Severity of Organophosphate Poisoning?

Background and aim: Organophosphate poisoning is a global health burden due to intentional and occupational exposure, particularly in Asian countries. Patients are usually monitored through serum acetylcholinesterase levels. Still, it is non-specific, does not correlate well with the severity of poisoning, and is not widely available in laboratory settings in developing countries. This study aims to assess serum baseline creatine phosphokinase (CPK) levels as a prognostic biomarker in acute organophosphate poisoning. Materials and methods: We recruited all patients older than 12 years who were admitted to the wards of the Indoor Medicine Ward in Burdwan Medical College and Hospital in West Bengal (India) because of ingestion or inhalation of organophosphorus compounds within the previous 12 hours between May 1, 2019, and November 1, 2020. Clinical severity was categorized according to Peradeniya organophosphorus poisoning (POP) scale. Serum CPK, pseudocholinesterase levels, and pH were measured. Levels were reassessed on days three and seven, and patients were followed-up until death or discharge. Results: 100 patients (68 men and 32 women) were included in the study. Most of them presented with miosis (98%), followed by abdominal pain (96%), diarrhea (78%), and vomiting (52%). In the multivariate analysis, the patients with a higher risk of being intubated were younger. Of the analytical levels, the one that showed a better relationship with the risk of intubation was the pseudocholinesterase level, although without statistical significance. Initial CPK levels, time of admission, or stratification on the POP severity scale, offered poor performance after adjustment. Conclusion: The analytical values of CPK or the POP severity scale at the time the patient presents in the emergency room have limited value to predict the final severity of the picture. The amount of the poison consumed should be collected for future studies to elucidate these differences.

(3 + 2) cycloaddition of 2-alkoxynaphthalenes with azaoxyallyl cations: access to benzo[e]indolones.

A reaction between 2-alkoxynaphthalene and an in situ formed azaoxyallyl cation has been reported under ambient reaction conditions. The (3 + 2) cycloaddition reaction followed by aryl C-OMe/C-OEt bond cleavage produces a variety of benzo[e]indolone derivatives. Based on the isolated intermediate from the control experiment and previous results, a possible mechanism has been drawn. Reduction of the N-O bond of the benzo[e]indolone derivative manifests the possibility of further functionalization of the products towards biologically important heterocyclic molecules.

Epidemiological drivers of mother to child HIV transmission in West Bengal, India: A retrospective cohort study.

BACKGROUND: HIV transmission through vertical route can be reduced to a large extent with combination of medical interventions. Apart from maternal HIV status several other epidemiological attributes determine this transmission dynamics.Objective: The objective of this study was to identify various associated factors that determine and modify the risk of HIV transmission from a mother living with HIV to her child.Materials and method: A retrospective cohort-study was conducted with 518 HIV-positive pregnant women with delivering live babies between April 2016 - September 2018. The HIV status of the children was ascertained with polymerase chain reaction. A number of socio-demographic and medical attributes were compared between HIV-positive (41) and HIV-negative babies (477) using bivariate and multivariate methods to identify disease modifying factors. RESULTS: Maternal HIV detection during the postnatal period (AOR = 11.2; 5.2 - 23.8), low birth weight (AOR = 2.7; 1.2 - 5.9), and vaginal delivery (AOR = 2.8; 1.01 - 7.7) were significantly associated with vertical transmission of HIV. Lower duration of maternal antiretroviral treatment and higher maternal age (>25 years) were also associated in bivariate analysis. CONCLUSION: The battery of PPTCT (Prevention of Parent to Child Transmission) interventions should be tailored in such a way to address all the epidemiological attributes influencing vertical transmission.

Arsenic exposure during pregnancy and postpartum maternal glucose tolerance: evidence from Bangladesh.

BACKGROUND: Arsenic exposure has been associated with gestational diabetes mellitus. However, the extent to which arsenic exposure during pregnancy is associated with postpartum glucose intolerance is unknown. METHODS: We studied 323 women in Bangladesh. We assessed arsenic exposure in early pregnancy via toenail and water samples. We measured fasting glucose and insulin in serum at a mean (SD) of 4.0 (3.5) weeks post-delivery. We ran covariate-adjusted, linear regression models to examine associations of arsenic concentrations with HOMA-IR, a marker of insulin resistance, and HOMA-ß, a marker of beta cell function. RESULTS: Median (IQR) arsenic concentration was 0.45 (0.67) µg/g in toenails and 2.0 (6.5) µg/L in drinking water. Arsenic concentrations during pregnancy were not associated with insulin resistance or beta cell function postpartum. HOMA-IR was 0.07% (- 3.13, 3.37) higher and HOMA-ß was 0.96% (- 3.83, 1.99) lower per IQR increment in toenail arsenic, but effect estimates were small and confidence intervals crossed the null. CONCLUSIONS: Although arsenic exposure during pregnancy has been consistently associated with gestational diabetes mellitus, we found no clear evidence for an adverse effect on postpartum insulin resistance or beta cell function.

Prevalence of syphilis infection and associated sociodemographic factors among antenatal-care attendees in Meghalaya, India: Revisiting HIV Sentinel Surveillance data.

BACKGROUND: Despite relatively simple prevention and treatment, syphilis remains a major social and public health concern worldwide, particularly in developing nations. OBJECTIVE: To estimate the prevalence and to determine the sociodemographic factors associated with syphilis infection among antenatal-care (ANC) attendees in Meghalaya, India. MATERIALS AND METHOD: A facility-based cross-sectional study was conducted utilizing National HIV Sentinel Surveillance of Meghalaya, January-March 2017. Pregnant women aged 15-49 years (n = 3015) were recruited consecutively, interviewed, and tested for syphilis by Venereal Disease Research Laboratory test in eight selected ANC sites representing all districts of Meghalaya. RESULTS: Prevalence of syphilis was found to be 1.03 % (95% CI = 0.67-1.39) (31/3015). Prevalence was maximum among illiterates with gradual lowering of adjusted odds ratio (AOR) with improvement of education. Women whose husbands had no income were associated with higher risk (AOR = 4.97, 95% CI = 1.11-22.20) of syphilis. Significant risk (OR = 2.42, 95% CI = 1.02-5.74) was also observed with Jaintia Hills residents as compared to Garo Hills. CONCLUSIONS: As high prevalence of gestational syphilis was identified in Meghalaya along with important sociodemographic predictors, evidence to policy translation is required at state and national level to scale up prevention, screening, and management of syphilis.

Socio-Demographic Correlates of HIV Sero-Discordance among Couples in West Bengal, India: a Cross Sectional Analysis.

Serodiscordant couples serve as potential sources of human immunodeficiency virus (HIV) transmission. Understanding the demographic dynamics of serodiscordant couples plays an important role in tailoring interventions to eliminate HIV infection. We conducted this cross-sectional analysis among 314 integrated counseling and testing centers in West Bengal, India, from April 2016 to March 2020. General individuals who were detected as HIV-reactive and whose spouses were also tested for HIV comprised the study population, in which a total of 8,740 couples were included. Sociodemographic variables were compared across concordant and discordant arms, as well as between male positive (M+ F-) and female positive (F+ M-) subgroups of serodiscordant couples. Among the couples studied, 35.2% (95% CI: 34.2-36.2%) were serodiscordant. Among serodiscordant couples, the proportion of M+ F- (86.1%) was significantly higher than that of F+ M- (13.9%). We observed that higher mean ages of couples, higher education, business and service occupations, and urban residence were significantly associated with the serodiscordance relationship (P < 0.05). A high mean age of couples and a low proportion of housewives were associated with the F+ M- subgroup. As approximately 35% of serodiscordant couples carry the risk of transmission to negative spouses, particularly in older age and urban residence, reorientation of HIV programs may be required to avert transmission in the future.

Scrub Typhus Masquerading as Limbic Encephalitis.

Scrub typhus, an acute febrile infectious disease prevalent in the 'tsutsugamushi triangle', is a mite-born rickettsial zoonosis, caused by Orientia tsutsugamushi. The clinical presentation is protean and involves multiple organ systems of the body, including central and peripheral nervous systems. We report a 22-year-old previously healthy Indian woman who presented with clinical (confusion, excessive sleepiness, cognitive dysfunction and focal seizures) and neuroimaging features of limbic encephalitis. After exclusion of common infectious, autoimmune and paraneoplastic causes, she was diagnosed with scrub typhus associated encephalitis, which responded to doxycycline and azithromycin therapy.

Unusual higher-order nonlinear optical properties in Au-coated triangular Ag-Au nanostructures.

Here, we report hitherto unobserved local field (LF)-assisted pump wavelength-dependent nonlinear optical (NLO) effects of three-photon (3PA)-induced four-photon absorption (4PA) at 532 nm and two-photon-induced 3PA at 730 nm in triangular-shaped core-shell Ag-Au nanoparticles (TrAg@Au) by femtosecond Z-scan. The shell thickness-dependent enhancement in the LF is observed by a COMSOL simulation. The intensity-dependent interplay between saturable and reverse-saturable absorptions along with switching of nonlinear (NL) phase is reported at 730 nm, showing the superiority of TrAg@Au in optical switching (OS). The optical limiting (OL) threshold (Fth) of 5.9(6.5)mJ/cm2 at 730 (532) nm boost their potential over benchmarked materials.

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.