Using a neural network to derive early childhood neurodevelopmental profiles in the New Hampshire Birth Cohort Study.

Background: Child-centred approaches represent a conceptual framework that emphasises the holistic characterisation of individual developmental patterns across cognitive, behavioural and social domains. As a complementary analytic tool, self-organising maps (SOMs), an artificial neural network, offer flexible, data-driven clustering capabilities that are well-suited to modeling complex, multidimensional and longitudinal developmental data. Despite their potential, few studies have applied such methods to profile early neurodevelopment, especially in rural populations.

Epigenetic dysregulation and the etiology of spina bifida.

Spina bifida is a complex and multifactorial congenital defect driven by both genetic and environmental factors. As such, epigenetic studies of spina bifida present an opportunity to study the joint contribution of both genes and the environment in the development of this disorder. This review focuses specifically on epigenetic research that may help us to understand the ways in which dysregulation of the epigenome and downstream cellular processes can confer increased risk of spina bifida.

Gestational vitamin D concentration and child cognitive development: a longitudinal cohort study in the Environmental influences on Child Health Outcomes Program.

Background: Low vitamin D concentrations are common-especially among those with darker pigmented skin-and are frequently observed during pregnancy. Given its important role in brain development, inadequate gestational vitamin D may impair child cognitive development.

Objectives: We aimed to evaluate associations of gestational vitamin D concentrations with childhood cognitive scores, explore whether this relationship differs by self-reported race, and examine sensitive exposure windows within pregnancy.

Time-varying exposure to element mixtures and children's cognition at 5 years of age: findings from the New Hampshire Birth Cohort Study.

Background: Exposure to metals and metalloids (hereafter referred to as 'metals') during gestation and early childhood may affect children's neurodevelopment. However, few studies have simultaneously evaluated the impact of exposure to both essential and non-essential metals across specific windows of exposure on children's neurodevelopmental outcomes.

Objective: To investigate whether levels of metals during gestation and the early postnatal period, individually and as a mixture, are related to child cognition at 5 years of age among participants in the New Hampshire Birth Cohort Study (NHBCS).

Intraindividual variability of semen quality, proteome, and sncRNA profiles in a healthy cohort of young adults.

Background: Within-subject variability of semen parameters and molecular components of ejaculates in young men remains poorly understood.

Objectives: To investigate intraindividual variability (IIV) of semen parameters and molecular markers in repeated ejaculates from young men.

Materials And Methods: Semen parameters were assessed in samples collected 6-8 days apart from 164 18-19-year old participants of the Russian Children's Study, a prospective cohort.

Hair mercury isotopes, a noninvasive biomarker for dietary methylmercury exposure and biological uptake.

. Fish and rice are the main dietary sources of methylmercury (MeHg); however, rice does not contain the same beneficial nutrients as fish, and these differences can impact the observed health effects of MeHg. Hence, it is important to validate a biomarker, which can distinguish among dietary MeHg sources.

Associations of Perinatal Metal and Metalloid Exposures with Early Child Behavioral Development Over Time in the New Hampshire Birth Cohort Study.

Research on the neurodevelopmental effects of metal(loid)s has focused mainly on outcomes assessed at one time point, even though brain development progresses over time. We investigated biomarkers of perinatal exposure to metals and changes in child behavior over time. We followed 268 participants from the prospective New Hampshire Birth Cohort Study between birth and age 5 years.

Multiple prenatal exposures and acute-care clinical encounters for asthma among children born to mothers living near a Superfund site.

Prenatal exposures are associated with childhood asthma, and risk may increase with simultaneous exposures. Pregnant women living in lower-income communities tend to have elevated exposures to a range of potential asthma risk factors, which may interact in complex ways. We examined the association between prenatal exposures and the risk of childhood acute-care clinical encounters for asthma (hospitalizations, emergency department visits, observational stays) using conditional logistic regression with a multivariable smoothing term to model the interaction between continuous variables, adjusted for maternal characteristics and stratified by sex.

arsenic exposure and early childhood motor development in the New Hampshire Birth Cohort Study.

Introduction: High-level prenatal and childhood arsenic (As) exposure characteristic of several regions in Asia (e.g., Bangladesh), may impact motor function.

Urinary biomarkers of exposure to toxic and essential elements: A comparison of infants fed with human milk or formula.

Background: Early-life exposure to nonessential (toxic) and essential trace elements can influence child development. Although infant formula powders and the water used to reconstitute them can contain higher concentrations of many elements compared with human milk, the influence of feeding mode on reliable biomarkers of infant exposure has rarely been demonstrated.

Methods: We evaluated associations between urinary biomarkers and feeding mode (exclusively human milk, exclusively formula, or combination-fed) for four toxic (arsenic, cadmium, nickel, and uranium) and three essential elements (cobalt, molybdenum, and selenium) using general linear models.

Pubertal progression in relation to peripubertal exposure to organochlorine chemicals in a cohort of Russian boys.

Background: Peripubertal concentrations of serum dioxins and polychlorinated biphenyls (PCBs) have demonstrated associations with altered age of pubertal onset and sexual maturity in boys, but associations with pubertal progression have received less attention.

Methods: The Russian Children's Study is a prospective cohort of 516 boys enrolled in 2003-2005 at age 8 or 9 and followed annually up to 19 years of age. Serum concentrations of dioxin-like toxic equivalents (TEQs), polychlorinated dibenzodioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and non-dioxin-like PCBs (NDL-PCBs) and whole blood lead levels (BLLs) were quantified from blood samples collected at study entry (age 8-9).

Bacterial Modification of the Association Between Arsenic and Autism-Related Social Behavior Scores.

Arsenic is related to neurodevelopmental outcomes and is associated with the composition of the gut microbiome. Data on the modifying role of the microbiome are limited. We probed suggestive relationships between arsenic and social behaviors to quantify the modifying role of the infant gut microbiome.

Adolescent endocrine disrupting chemical exposure and academic achievement.

Background: Epidemiologic studies support associations of exposure to endocrine disrupting chemicals (EDCs), such as some phthalates, phenols, and parabens with a wide range of cognitive and behavioral traits. While many of these traits are associated with academic achievement, the relationship of EDC exposure specifically with academic achievement in adolescence has not yet been studied.

Objective: We assessed the association of urinary biomarker concentrations of EDCs with academic achievement in adolescents as well as the potential for psychosocial factors to modify associations.

Greater Gestational Vitamin D Status is Associated with Reduced Childhood Behavioral Problems in the Environmental Influences on Child Health Outcomes Program.

Background: Vitamin D deficiency is common in pregnancy. Vitamin D plays an important role in the developing brain, and deficiency may impair childhood behavioral development.

Objectives: This study examined the relationship between gestational 25(OH)D concentrations and childhood behavior in the Environmental influences on Child Health Outcomes (ECHO) Program.

Phenotypically driven subgroups of ASD display distinct metabolomic profiles.

Autism Spectrum Disorder (ASD) is a heterogeneous condition that includes a broad range of characteristics and associated comorbidities; however, the biology underlying the variability in phenotypes is not well understood. As ASD impacts approximately 1 in 100 children globally, there is an urgent need to better understand the biological mechanisms that contribute to features of ASD. In this study, we leveraged rich phenotypic and diagnostic information related to ASD in 2001 individuals aged 4 to 17 years from the Simons Simplex Collection to derive phenotypically driven subgroups and investigate their respective metabolomes.

Birth Outcomes in Relation to Prenatal Exposure to Per- and Polyfluoroalkyl Substances and Stress in the Environmental Influences on Child Health Outcomes (ECHO) Program.

Background: Per- and polyfluoroalkyl substances (PFAS) are persistent and ubiquitous chemicals associated with risk of adverse birth outcomes. Results of previous studies have been inconsistent. Associations between PFAS and birth outcomes may be affected by psychosocial stress.

Early pregnancy essential and non-essential metal mixtures and maternal antepartum and postpartum depressive symptoms.

Background: Mood disorders are common during and after pregnancy, and environmental metals may contribute to increased risk. Antepartum metal exposures have not been well characterized in relation to maternal depression. We evaluated the extent to which early pregnancy erythrocyte concentrations of essential and non-essential metals were prospectively associated with antepartum and postpartum depressive symptoms.

The association of prenatal manganese exposure with problem-solving skills and its mediation by the building blocks of executive function.

Background: Problem-solving skills build upon three core executive functions: inhibition, working memory, and cognitive flexibility. There is evidence of adverse associations of prenatal exposure to manganese (Mn) with core executive functions, but less is known about Mn associations with problem-solving or potential mediators of this association.

Objectives: This study aimed to investigate the association of prenatal Mn exposure with problem-solving and to identify potential neuropsychological mechanisms through which this association may be mediated.

Urinary phthalate metabolite concentrations during four windows spanning puberty (prepuberty through sexual maturity) and association with semen quality among young Russian men.

Aim: To prospectively investigate the associations of urinary phthalate metabolite concentrations measured at four time points spanning pubertal development with semen parameters in Russian men.

Design: 516 boys were enrolled at ages 8-9 years (2003-2005) and followed annually.

Methods: Urine samples were collected annually and pooled into four exposure windows [prepuberty, early puberty, late puberty and sexual maturity] based on physician assessed Tanner genitalia stages and testicular volume.

Associations of prepubertal urinary phthalate metabolite concentrations with pubertal onset among a longitudinal cohort of boys.

Background: Although phthalate exposures have been associated with adverse effects on male reproductive health, few studies have explored longitudinal associations with male pubertal development.

Objectives: We examined the association of prepubertal urinary concentrations of phthalate metabolites with age at pubertal onset in a prospective cohort of Russian boys.

Methods: At enrollment at ages 8-9 years, medical history, dietary, and demographic information was collected.