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Environmental pollutant is considered to be one of the important factors affecting adolescent growth. However, the effects of volatile organic compounds (VOCs) exposure on adolescent growth have not been assessed. Data from the National Health and Nutrition Examination Survey (NHANES) 2011-2018 was used to examine the associations between VOCs exposure and adolescent growth indicators through three statistical models. The mediating effect of bone mineral density (BMD) on these associations was examined. The potential pathways and key targets were identified by the network pharmacology analysis methods. This study included 746 adolescents. Three statistical methods consistently showed a negative correlation between VOCs exposure and adolescent growth indicators. Furthermore, BMD mediated the relationship between VOCs exposure and adolescent growth indicators, with mediated proportion ranging from 4.3 % to 53.4 %. Network pharmacology analysis found a significant enrichment in IL-17 signaling pathway. Moreover, the adverse effects of VOCs exposure on adolescent growth were observed to significantly attenuate in adolescents with high serum vitamin D levels. Our results suggested that VOCs exposure was an adverse factor affecting adolescent growth, with BMD playing a significant regulatory role, and IL-17 signaling pathway was the underlying mechanism. Vitamin D supplementation may be a viable strategy to prevent VOCs exposure from affecting adolescent growth., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Introduction: Prenatal exposure to supraphysiological glucocorticoid (GC) levels may lead to long-lasting developmental changes in numerous biological systems. Our prior study identified an association between prenatal GC prophylaxis and reduced cognitive performance, electrocortical changes, and altered autonomic nervous system (ANS) activity in children aged 8-9 years. This follow-up study aimed to examine whether these findings persisted into adolescence., Material and Methods: Prospective observational follow-up study involving twenty-one 14- to 15-year-old adolescents born to mothers who received betamethasone for induction of fetal lung maturation in threatened preterm birth, but who were born with a normal weight appropriate for their gestational age (median 37 +4 gestational weeks). Thirty-five children not exposed to betamethasone served as the reference group (median 37 +6 gestational weeks). The primary endpoint was cognitive performance, measured by intelligence quotient (IQ). Key secondary endpoints included symptoms of attention-deficit/hyperactivity disorder (ADHD) and metabolic markers. Additionally, we determined electrocortical (electroencephalogram), hypothalamus-pituitary-adrenal axis (HPAA), and ANS activity in response to a standardized stress paradigm., Results: No statistically significant group difference was observed in global IQ (adjusted mean: betamethasone 103.9 vs references 105.9, mean difference -2.0, 95% confidence interval [CI]: -7.12 to 3.12, p = 0.44). Similarly, ADHD symptoms, metabolic markers, the overall and stress-induced activity of the HPAA and the ANS did not differ significantly between groups. However, the betamethasone group exhibited reduced electrocortical activity in the frontal brain region (spectral edge frequency-adjusted means: 16.0 Hz vs 17.8 Hz, mean difference -1.83 Hz, 95% CI: -3.21 to -0.45, p = 0.01)., Conclusions: In 14- to 15-year-old adolescents, prenatal GC exposure was not associated with differences in IQ scores or ANS activity compared to unexposed controls. However, decelerated electrocortical activity in the frontal region potentially reflects disturbances in the maturation of cortical and/or subcortical brain structures. The clinical significance of these changes remains unknown. Given the small sample size, selective participation/loss of follow-up and potential residual confounding, these findings should be interpreted cautiously. Further research is required to replicate these results in larger cohorts before drawing firm clinical conclusions., (© 2024 The Author(s). Acta Obstetricia et Gynecologica Scandinavica published by John Wiley & Sons Ltd on behalf of Nordic Federation of Societies of Obstetrics and Gynecology (NFOG).)

Iron is needed for normal development in adolescence. Exposure to individual environmental metals (e.g., lead) has been associated with altered iron status in adolescence, but little is known about the cumulative associations of multiple metals with Fe status. We used data from the 2017-2018 National Health and Nutrition Examination Survey (NHANES) to examine associations between a metal mixture (lead, manganese, cadmium, selenium) and iron status in 588 U.S. adolescents (12-17 years). We estimated cumulative and interactive associations of the metal mixture with five iron status metrics using Bayesian Kernel Machine Regression (BKMR). Higher concentrations of manganese and cadmium were associated with lower log-transformed ferritin concentrations. Interactions were observed between manganese, cadmium, and lead for ferritin and the transferrin receptor, where iron status tended to be worse at higher concentrations of all metals. These results may reflect competition between environmental metals and iron for cellular uptake. Mixed metal exposures may alter normal iron function, which has implications for adolescent development., (© 2022 Wiley Periodicals LLC.)

Objective: The aim was to evaluate the results of diagnosis, follow-up and treatment of the patients who recieved growth hormone (GH) treatment for the last 10 years and to determine the differences in the process and results over the years., Methods: Anthropometric, clinical, laboratory data, treatment adherence and side effects were evaluated retrospectively in 767 patients who recieved GH treatment between 2009-2018. Patients were grouped as isolated GH deficiency (IGHD), multiple pituitary hormone deficiency (MPHD), small for gestational age (SGA), and Turner syndrome (TS) depending on diagnosis., Results: GH treatment was started in 689 cases (89.8%) with IGHD, 24 (3.1%) with MPHD, 26 (3.4%) with SGA and 28 (3.7%) with TS. Median age of GH treatment onset was the earliest in SGA (8.4 years) and the latest in the IGHD group (12.0 years). At the time of treatment cessation, height standard deviation score (SDS) in IGHD and MPHD was significantly higher than treatment initiation time, whereas there was no significant difference in TS and SGA. One hundred eighty-nine cases reached the final height. Final heights for girls/boys were: IGHD 154/164.9 cm; MPHD 156.2/163.5 cm; TS 146.7 cm; and SGA 145.7/-cm, respectively. Target height SDS-final height SDS median values were IGHD: 0.1, MPHD: 0.6, SGA: 0.5, TS: 2.4 respectively. The patients’ treatment compliance was high (92%) and the incidence of side effects was low (2.7%)., Conclusion: In our cohort, GH treatment start age was late and no difference in this was observed in the last 10 years. The improvement in the height SDS was most marked in the IGHD and MPHD groups, the least in the TS and SGA groups.

Prenatal alcohol exposure (PAE) can have immediate and long-lasting toxic and teratogenic effects on an individual's development and health. As a toxicant, alcohol can lead to a variety of physical and neurological anomalies in the fetus that can lead to behavioral and other impairments which may last a lifetime. Recent studies have focused on identifying mechanisms that mediate the immediate teratogenic effects of alcohol on fetal development and mechanisms that facilitate the persistent toxic effects of alcohol on health and predisposition to disease later in life. This review focuses on the contribution of epigenetic modifications and intercellular transporters like extracellular vesicles to the toxicity of PAE and to immediate and long-term consequences on an individual's health and risk of disease.

Background: The present study investigated the role of proteins from the bromodomain and extra-terminal (BET) family in schizophrenia-like abnormalities in a neurodevelopmental model of schizophrenia induced by prenatal methylazoxymethanol (MAM) administration (MAM-E17)., Methods: An inhibitor of BET proteins, JQ1, was administered during adolescence on postnatal days (P) 23-P29, and behavioural responses (sensorimotor gating, recognition memory) and prefrontal cortical (mPFC) function (long-term potentiation (LTP), molecular and proteomic analyses) studies were performed in adult males and females., Results: Deficits in sensorimotor gating and recognition memory were observed only in MAM-treated males. However, adolescent JQ1 treatment affected animals of both sexes in the control but not MAM-treated groups and reduced behavioural responses in both sexes. An electrophysiological study showed LTP impairments only in male MAM-treated animals, and JQ1 did not affect LTP in the mPFC. In contrast, MAM did not affect activity-dependent gene expression, but JQ1 altered gene expression in both sexes. A proteomic study revealed alterations in MAM-treated groups mainly in males, while JQ1 affected both sexes., Conclusions: MAM-induced schizophrenia-like abnormalities were observed only in males, while adolescent JQ1 treatment affected memory recognition and altered the molecular and proteomic landscape in the mPFC of both sexes. Thus, transient adolescent inhibition of the BET family might prompt permanent alterations in the mPFC.

Objectives: The current study evaluated the long-term effects of methylphenidate (MPH) discontinuation on growth parameters in Turkish children and adolescents with attention-deficit/hyperactivity disorder (ADHD)., Experimental Design: 432 children and adolescents (aged 6-18 years) with ADHD receiving MPH for at least 1 year between March 2012 and January 2019 were included in a retrospective cohort study. We analyzed weight, height, and body mass index (BMI) standard deviation z scores (SDS) of groups that either did (ADHD-C) or did not (ADHD-DC) discontinue MPH. Growth parameters were converted to z scores as normative values for the Turkish population to compare the measurements at baseline and the last follow-up visit by using the paired sample t-test., Principal Observations: In patients from the ADHD-C group, statistically significant negative correlations were found between age at starting MPH and differences in weight and height SDS between baseline and follow-up. Children had a greater reduction in weight and height compared to adolescents. When we evaluated the differences in pre-and post-treatment growth factors, we found no significant differences between the groups in terms of growth parameters., Conclusions: Our data showed that chronic use of MPH was likely responsible for changes in height and weight parameters., (Copyright © 1964–2019 by MedWorks Media Inc, Los Angeles, CA All rights reserved. Printed in the United States.)

Phthalates, a class of endocrine-disrupting chemicals, are used widely in many consumer products, and exposure can interfere with a range of hormonal functions during early life. These disruptions may alter development during late childhood and adolescence. This article discusses the potential effects of phthalate exposure on adiposity, puberty, and neurodevelopment during late childhood and adolescence. It also highlights studies of behavioral interventions to reduce phthalate exposures and the roles of health care professionals and policy makers in preventing phthalate exposure., Competing Interests: Disclosure Dr J.M. Braun was financially compensated for serving as an expert witness for plaintiffs in litigation related to tobacco smoke exposures and received an honorarium for serving on an advisory board to Quest Diagnostics. Dr J.M. Braun served as an expert witness in litigation related to perfluorooctanoic acid contamination in drinking water in New Hampshire. Funds received from this arrangement are paid to Brown University and are not used for direct personal benefit (e.g., salary/fringe, travel)., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Context: Hormonal interventions in adolescents with gender dysphoria may have adverse effects, such as reduced bone mineral accrual., Objective: To describe bone mass development in adolescents with gender dysphoria treated with gonadotropin-releasing hormone analogues (GnRHa), subsequently combined with gender-affirming hormones., Design: Observational prospective study., Subjects: 51 transgirls and 70 transboys receiving GnRHa and 36 transgirls and 42 transboys receiving GnRHa and gender-affirming hormones, subdivided into early- and late-pubertal groups., Main Outcome Measures: Bone mineral apparent density (BMAD), age- and sex-specific BMAD z-scores, and serum bone markers., Results: At the start of GnRHa treatment, mean areal bone mineral density (aBMD) and BMAD values were within the normal range in all groups. In transgirls, the mean z-scores were well below the population mean. During 2 years of GnRHa treatment, BMAD stabilized or showed a small decrease, whereas z-scores decreased in all groups. During 3 years of combined administration of GnRHa and gender-affirming hormones, a significant increase of BMAD was found. Z-scores normalized in transboys but remained below zero in transgirls. In transgirls and early pubertal transboys, all bone markers decreased during GnRHa treatment., Conclusions: BMAD z-scores decreased during GnRHa treatment and increased during gender-affirming hormone treatment. Transboys had normal z-scores at baseline and at the end of the study. However, transgirls had relatively low z-scores, both at baseline and after 3 years of estrogen treatment. It is currently unclear whether this results in adverse outcomes, such as increased fracture risk, in transgirls as they grow older., (© Endocrine Society 2020.)

Objectives Adequate treatment of congenital hypothyroidism (CH) is required for normal growth and sexual development. To evaluate pubertal development in patients with permanent CH detected by a statewide Neonatal Screening Program of Paraná and, secondly, to evaluate adult height (AH) in a subgroup of patients. Methods Clinical, laboratory, and auxological data obtained from medical records of 174 patients (123 girls). Results Median chronological age (CA) at treatment initiation was 24 days, and mean initial levothyroxine dose was 11.7 ± 1.9 μg/kg/day; mean CA at puberty onset was 11.5 ± 1.3 years (boys) and 9.7 ± 1.2 years (girls); mean CA in girls who underwent menarche (n=81) was 12.1 ± 1.1 years. Thyroid-stimulating hormone (TSH) values above the normal range were observed in 36.4% of the boys and 32.7% of the girls on puberty onset, and in 44.6% around menarche. Among 15 boys and 66 girls who had reached the AH, the median height z-score value was significantly greater than the target height (TH) z-score value in boys (p=0.01) and in girls (p<0.001). Boys with normal TSH values at puberty onset had greater mean AH z-score compared with boys with TSH values above the normal range (p=0.04). Conclusions In this group, pubertal development in girls with CH was not different from that reported in healthy girls in the general Brazilian population. Boys with higher TSH at puberty onset may have an increased risk of not reaching their potential height compared with those with normal TSH during this period. In a subgroup who attained AH, the median AH z-score was greater than the median TH z-score.

Study Registration: PROSPERO registration numbers CRD42018105196 and CRD42018088868., Competing Interests: MF has been a member of the Infant Nutrition Working Group at EFSA (European Food Safety Authority) since 2013. She was involved in data analysis and publication of randomised trials of LCPUFA-supplemented infant formulas funded by grants from Numico Res BV and Heinz UK. The companies also provided the infant formulas for the studies. She was also involved in follow-up studies (including cognitive outcome) of children and adolescents from randomised trials of LCPUFA-supplemented formulas, with funding from the Medical Research Council and European Union (FP6-FOOD-2005-007036). MLV, SD, JJ and REG have no competing interests to declare.

Adolescent use of amphetamine and its closely related, methylated version methamphetamine, is alarmingly high in those who use drugs for nonmedical purposes. This raises serious concerns about the potential for this drug use to have a long-lasting, detrimental impact on the normal development of the brain and behavior that is ongoing during adolescence. In this review, we explore recent findings from both human and laboratory animal studies that investigate the consequences of amphetamine and methamphetamine exposure during this stage of life. We highlight studies that assess sex differences in adolescence, as well as those that are designed specifically to address the potential unique effects of adolescent exposure by including groups at other life stages (typically young adulthood). We consider epidemiological studies on age and sex as vulnerability factors for developing problems with the use of amphetamines, as well as human and animal laboratory studies that tap into age differences in use, its short-term effects on behavior, and the long-lasting consequences of this exposure on cognition. We also focus on studies of drug effects in the prefrontal cortex, which is known to be critically important for cognition and is among the later maturing brain regions. Finally, we discuss important issues that should be addressed in future studies so that the field can further our understanding of the mechanisms underlying adolescent use of amphetamines and its outcomes on the developing brain and behavior., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Background: Data on long-term health outcomes of children exposed in utero to thiopurines and anti-TNF medications are lacking., Aims: To examine the association between in utero exposure to thiopurines and anti-TNF medications and child health outcomes of site-specific groups of infections, using a composite endpoint including psychiatric diagnoses/autism spectrum disorder (ASD)/attention deficit hyperactivity disorder (ADHD), and malignancies during childhood/adolescence., Methods: A nationwide cohort study based on Danish health registries included 1 311 009 live born children during 1995 through 2015. Outcomes were based on hospital diagnoses (in-patients/out-patients/emergency department contacts)., Results: In total, 1048 children were exposed in utero to thiopurines and 1 309 961 were unexposed. The adjusted hazard ratios (HRs) for site-specific groups of infections in the first 3 years of life were close to unity. The adjusted HR of psychiatric diagnoses/ASD/ADHD was 1.11 (95% CI 0.81-1.52). The HR of malignancies was not calculated (only two events among the exposed). In total, 493 children were exposed in utero to anti-TNF medications and 728 055 were unexposed. Within the first year of life, the adjusted HR of respiratory, urological/gynaecological infections and other infections were 1.34 (95% CI 1.03-1.74), 2.36 (95% CI 1.15-4.81) and 1.61 (95% CI 1.21-2.13), respectively. We found no increased risk of other adverse outcomes., Conclusions: After in utero exposure to thiopurines, we found no increased risk of infections, psychiatric diagnoses/ASD/ADHD, or malignancies during childhood/adolescence. After in utero exposure to anti-TNF medications, the risk of respiratory, urological/gynaecological infections and other infections was increased during the first year of life., (© 2020 John Wiley & Sons Ltd.)

Background: Studies with children exposed to methylmercury (MeHg) through fish consumption in the Brazilian Amazon region report that the high levels of hair Hg are associated with significant decreases in intelligence, memory, attention, and visuospatial processing., Objective: To investigate the relationship between mercury exposure and neuropsychological functions in riverside communities of the Brazilian Amazon., Method: 263 participants aged 6 to 14 years old were assessed, from resettlement regions, near the Madeira river, Rondônia, Brazil. To assess the neuropsychological functions we used the following instruments: intelligence (WASI), working memory (Corsi Block-Tapping Task and Digit Span), verbal fluency (Word Generation - NEPSY II), inhibitory control (Inhibition Errors - NEPSY II), shifting (Trail Making Test) and manual motor dexterity (Grooved PegBoard Test). Socioeconomic status was obtained through household surveys. Total Hg levels were quantified hair samples (Total HgH) collected from the occipital region of the scalp and analyzed by Cold Vapor Atomic Absorption Spectrometry., Results: The group in the upper quartile of Total HgH levels presented lower scores on the tasks that assessed estimated IQ, visuospatial working memory, semantic knowledge and phonological verbal fluency, when compared to the group in the lower quartile level. A regression analysis controlled for age, sex, and maternal education showed that for each increase of 10 μg/g of Total HgH, there was a decrease around half standard deviation in Verbal IQ, estimated IQ scores, semantic knowledge, phonological verbal fluency and for verbal and visuospatial working memory., Conclusions: High concentrations of Total Hg in hair were associated with a lower performance in neuropsychological functions tests. The results show that environmental exposure to Hg is associated to children and adolescents' lower neuropsychological performance in the riverine and resettled areas of the Brazilian Amazon region., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Recent extensive evidence indicates that air pollution, in addition to causing respiratory and cardiovascular diseases, may also negatively affect the brain and contribute to central nervous system diseases. Air pollution is comprised of ambient particulate matter (PM) of different sizes, gases, organic compounds, and metals. An important contributor to PM is represented by traffic-related air pollution, mostly ascribed to diesel exhaust (DE). Epidemiological and animal studies have shown that exposure to air pollution may be associated with multiple adverse effects on the central nervous system. In addition to a variety of behavioral abnormalities, the most prominent effects caused by air pollution are oxidative stress and neuro-inflammation, which are seen in both humans and animals, and are supported by in vitro studies. Among factors which can affect neurotoxic outcomes, age is considered most relevant. Human and animal studies suggest that air pollution may cause developmental neurotoxicity, and may contribute to the etiology of neurodevelopmental disorders, including autism spectrum disorder. In addition, air pollution exposure has been associated with increased expression of markers of neurodegenerative disease pathologies, such as alpha-synuclein or beta-amyloid, and may thus contribute to the etiopathogenesis of neurodegenerative diseases, particularly Alzheimer's disease and Parkinson's disease., Competing Interests: Declaration of Competing Interest The authors declare that they have no conflicts of interest., (Copyright © 2020. Published by Elsevier Inc.)

Purpose: To assess how adolescent development progresses and psychiatric symptoms develop among transsexual adolescents after starting cross-sex hormone treatment. Materials and methods: Retrospective chart review among 52 adolescents who came into gender identity assessment before age 18, were diagnosed with transsexualism and started hormonal gender reassignment. The subjects were followed over the so-called real-life phase of gender reassignment. Results: Those who did well in terms of psychiatric symptoms and functioning before cross-sex hormones mainly did well during real-life. Those who had psychiatric treatment needs or problems in school, peer relationships and managing everyday matters outside of home continued to have problems during real-life. Conclusion: Medical gender reassignment is not enough to improve functioning and relieve psychiatric comorbidities among adolescents with gender dysphoria. Appropriate interventions are warranted for psychiatric comorbidities and problems in adolescent development.

We used data from the 2016 and 2017 SummerStyles survey (N = 4,186 and 4,066, respectively) to assess US adults' perceptions about the harms of nicotine in electronic vapor products (EVP) to the developing adolescent brain. Of respondents in 2016, 68.5% agreed exposure to nicotine in EVP was harmful, and of respondents in 2017, 62.6% agreed (P < .001). This agreement varied by several covariates. Continued efforts are warranted to educate the public about the risks of EVP use among youth, including the harmful effects of nicotine exposure on the developing adolescent brain.

Adolescence is a critical neurodevelopmental period for both excitatory and inhibitory (E/I) neurotransmission and often witnesses the typical onsets of schizophrenia. One possibility is that disruptions in adolescent neurodevelopmental processes may produce schizophrenia-like behavioral and neurobiological abnormalities. We previously reported that subchronic treatment of adolescent animals with the N-methyl-D-aspartate (NMDA) receptor antagonist MK-801 induced cognitive deficits and reduced interneuron densities in rat medial prefrontal cortex, and these changes persisted one week after MK-801 exposure. However, it remains unclear how this treatment may affect E/I balance in hippocampus, which has long been associated with the pathophysiology of schizophrenia. Here, we examined hippocampal E/I biomarkers in adolescent rats treated with MK-801 (0.2 mg/kg, i.p., 14 days) and found increases in the ratio of the expression levels of vesicular glutamate transporter-1 (VGluT1) and vesicular gamma-aminobutyric acid (GABA) transporter (VGAT) 24 h and 7 days after MK-801 exposure. Interestingly, the increased VGluT1/VGAT ratio at the two time points was driven by upregulated VGluT1 expression and downregulated VGAT expression, respectively. The decrease in VGAT expression persisted 14 days after MK-801 exposure and recovered two weeks later. No alterations in hippocampal interneuron densities were observed. Behaviorally, the treatment decreased prepulse inhibition at 24 h but not 14 days, after MK-801 exposure. Taken together, these results demonstrate that subchronic NMDA receptor blockade during adolescence induces long-term, but not permanent, E/I imbalance in the rat hippocampus, which could be attributed to the dysregulation of glutamatergic transmission in the short term and of GABAergic transmission in the long term., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Objective: Amidst the evolving policy surrounding cannabis legalization in the United States, cannabis use is becoming increasingly prevalent as perceptions of harm decrease, particularly among adolescents. Cannabis and alcohol are commonly used by adolescents and are often used together. However, developmental research has historically taken a "single substance" approach to examine the association of substance use and adolescent brain and behavior rather than examining co-(or poly-substance) use of multiple substances, such as cannabis and alcohol. Thus, the acute effects of cannabis and alcohol, and the impact of co-use of cannabis and alcohol on the adolescent brain, cognitive function and subsequent psychosocial outcomes remains understudied. This narrative review aims to examine the effects of cannabis and alcohol on adolescents across a number of behavioral and neurobiological outcomes. Methods: The PubMed and Google Scholar databases were searched for the last 10 years to identify articles reporting on acute effects of cannabis and alcohol administration, and the effects of cannabis and alcohol on neuropsychological, neurodevelopmental, neural (e.g., structural and functional neuroimaging), and psychosocial outcomes in adolescents. When adolescent data were not available, adult studies were included as support for potential areas of future direction in adolescent work. Results: Current studies of the impact of cannabis and alcohol on adolescent brain and behavior have yielded a complicated pattern. Some suggest that the use of cannabis in addition to alcohol during adolescence may have a "protective" effect, yielding neuropsychological and structural brain outcomes that are better than those for adolescents who use only alcohol. However, other adolescent studies suggest that cannabis and alcohol co-use is associated with negative health and social outcomes such as poorer academic performance and impaired driving. Conclusion: Variation in study methodologies, policy-level limitations and our limited understanding of the developmental neurobiological effects of cannabis preclude the straightforward interpretation of the existing data on adolescent cannabis and alcohol use. Further research on this topic is requisite to inform the development of effective intervention and prevention programs for adolescent substance users, which hinge on a more comprehensive understanding of how cannabis-and its intersection with alcohol-impacts the developing brain and behavior.

Background: After the discovery of fluoride as a caries-preventing agent in the mid-twentieth century, fluoridation of community water has become a widespread intervention, sometimes hailed as a mainstay of modern public health. However, this practice results in elevated fluoride intake and has become controversial for two reasons. First, topical fluoride application in the oral cavity appears to be a more direct and appropriate means of preventing caries. Second, systemic fluoride uptake is suspected of causing adverse effects, in particular neurotoxicity during early development. The latter is supported by experimental neurotoxicity findings and toxicokinetic evidence of fluoride passing into the brain., Method: An integrated literature review was conducted on fluoride exposure and intellectual disability, with a main focus on studies on children published subsequent to a meta-analysis from 2012., Results: Fourteen recent cross-sectional studies from endemic areas with naturally high fluoride concentrations in groundwater supported the previous findings of cognitive deficits in children with elevated fluoride exposures. Three recent prospective studies from Mexico and Canada with individual exposure data showed that early-life exposures were negatively associated with children's performance on cognitive tests. Neurotoxicity appeared to be dose-dependent, and tentative benchmark dose calculations suggest that safe exposures are likely to be below currently accepted or recommended fluoride concentrations in drinking water., Conclusion: The recent epidemiological results support the notion that elevated fluoride intake during early development can result in IQ deficits that may be considerable. Recognition of neurotoxic risks is necessary when determining the safety of fluoride-contaminated drinking water and fluoride uses for preventive dentistry purposes.

It is over sixty years since the first administration of human growth hormone (GH) to children with GH deficiency, and over thirty years since recombinant human GH has been available for treatment of GH deficiency and a wider range of non-GH deficiency disorders. From a diagnostic perspective, genetic analysis, using single gene or Sanger sequencing and more recently next generation or whole exome sequencing, has brought advances in the diagnosis of specific causes of short stature, which has enabled therapy to be targeted more accurately. Genetic discoveries have ranged from defects of pituitary development and GH action to abnormalities in intracellular mechanisms, paracrine regulation and cartilage matrix formation. The strategy of GH therapy using standard doses has evolved to individualised GH dosing, depending on diagnosis and predictors of growth response. Evidence of efficacy of GH in GH deficiency, Turner syndrome and short children born small for gestational age is reviewed. The importance of critical assessment of growth response is discussed, together with the recognition and management of a poor or unsatisfactory growth response and the organisational issues related to prevention, detection and intervention regarding suboptimal adherence to GH therapy.

Cannabis use during adolescence has been linked to deleterious effects on brain integrity. This article summarizes findings from two prospective investigations (3 and 6 years, on average) on adolescent cannabis use from our laboratory that utilize structural neuroimaging and neurocognitive assessment approaches. Across most studies, findings suggest recency, frequency, and age of onset of cannabis use are likely key variables in predicting poorer neural health outcomes. There is some evidence that preexisting differences in brain architecture may also contribute to vulnerability and outcome differences. Ongoing large-scale prospective studies of youth will be able to disentangle how both cannabis use as well as pre and postexposure differences play a role in divergent outcomes among youth who use cannabis., (© 2019 Wiley Periodicals, Inc.)

Evidence obtained in recent decades has demonstrated that the brain still matures in adolescence. Changes in neural connectivity occur in different regions, including cortical and subcortical structures, which undergo modifications in white and gray matter densities. These alterations concomitantly occur in some neurotransmitter systems and hormone secretion, which markedly influence the refinement of certain brain areas and neural circuits. The immaturity of the adolescent brain makes it more vulnerable to the effects of alcohol and drug abuse, whose use can trigger long-term behavioral dysfunction. This article reviews the action of alcohol and drug abuse (cannabis, cocaine, opioids, amphetamines, anabolic androgenic steroids) in the adolescent brain, and their impact on both cognition and behavioral dysfunction, including predisposition to drug abuse in later life. It also discusses recent evidence that indicates the role of the neuroimmune system response and neuroinflammation as mechanisms that participate in many actions of ethanol and drug abuse in adolescence, including the neurotoxicity and alterations in neurocircuitry that contribute to the dysfunctional behaviors associated with addiction. The new data suggest the therapeutic potential of anti-inflammatory targets to prevent the long-term consequences of drug abuse in adolescence., (Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.)

The abuse of volatile solvents such as toluene is a significant public health concern, predominantly affecting adolescents. To date, inhalant abuse research has primarily focused on the central nervous system; however, inhalants also exert effects on other organ systems and processes, including metabolic function and energy balance. Adolescent inhalant abuse is characterized by a negative energy balance phenotype, with the peak period of abuse overlapping with the adolescent growth spurt. There are multiple components within the central and peripheral regulation of energy balance that may be affected by adolescent inhalant abuse, such as impaired metabolic signaling, decreased food intake, altered dietary preferences, disrupted glucose tolerance and insulin release, reduced adiposity and skeletal density, and adrenal hypertrophy. These effects may persist into abstinence and adulthood, and the long-term consequences of inhalant-induced metabolic dysfunction are currently unknown. The signs and symptoms resulting from chronic adolescent inhalant abuse may result in a propensity for the development of adult-onset metabolic disorders such as type 2 diabetes, however, further research investigating the long-term effects of inhalant abuse upon energy balance and metabolism are needed. This review addresses several aspects of the short- and long-term effects of inhalant abuse relating to energy and metabolic processes, including energy balance, intake and expenditure; dietary preferences and glycemic control; and the dysfunction of metabolic homeostasis through altered adipose tissue, bone, and hypothalamic-pituitary-adrenal axis function.

Lead is a neurotoxin that produces long-term, perhaps irreversible, effects on health and well-being. This article summarizes clinical and preclinical studies that have employed a variety of research techniques to examine the neurotoxic effects of low levels of lead exposure. A historical perspective is presented, followed by an overview of studies that examined behavioral and cognitive outcomes. In addition, a short summary of potential mechanisms of action is provided with a focus on calcium-dependent processes. The current level of concern, or reference level, set by the CDC is 5 μg/dL of lead in blood and a revision to 3.5 μg/dL has been suggested. However, levels of lead below 3 μg/dL have been shown to produce diminished cognitive function and maladaptive behavior in humans and animal models. Because much of the research has focused on higher concentrations of lead, work on low concentrations is needed to better understand the neurobehavioral effects and mechanisms of action of this neurotoxic metal., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Alcohol use continues to be problematic for youth and young adults in the United States. Understanding of neurobiology and neuroplasticity continues to highlight the potential adverse impact of underage drinking on the developing brain. This policy statement provides the position of the American Academy of Pediatrics on the issue of alcohol and is supported by an accompanying technical report., Competing Interests: POTENTIAL CONFLICT OF INTEREST: The authors have indicated they have no potential conflicts of interest to disclose., (Copyright © 2019 by the American Academy of Pediatrics.)

The aim of this study was to analyse the published literature on the potential effects of manganese exposure from drinking water on school-age children, with emphasis on cognitive, and neurodevelopment and behavioural effects. A systematic review of up-to-date scientific evidence published from 2006 to 2017 was conducted using Science Direct. A further search was carried out using PubMed and Web of Science. A total of 21 studies were reviewed and categorised into 12 cognitive and 9 neurodevelopment and behavioural effects. The most utilised cognitive test was the Wechsler Intelligence Scale for Children (WISC) or some subtests from it. 10 of the 12 studies on cognitive effects reported an adverse effect of manganese exposure from drinking water on children. 3 out of the 9 studies on neurodevelopment and behavioural effects reported that manganese exposure from drinking water was associated with poorer neurobehavioural performances in school children. 4 others implied the presence of some sex-specific associations with manganese exposure. 1 study suggested that children suffering from attention deficit hyperactivity disorder (ADHD) may be more susceptible to manganese exposure. Another study suggested that manganese was a beneficial nutrient as well as a neurotoxicant. Regardless of the limitations of the studies analysed, the adverse effects of manganese exposure from drinking water on school-aged children is sufficiently demonstrated. Further investigation into the subject to address inconsistencies in existing studies is recommended., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Alcohol use continues to be a major concern from preadolescence through young adulthood in the United States. Results of recent neuroscience research have helped to elucidate neurobiological models of addiction, substantiated the deleterious effects of alcohol on adolescent brain development, and added additional evidence to support the call to prevent and reduce underage drinking. This technical report reviews the relevant literature and supports the accompanying policy statement in this issue of Pediatrics ., Competing Interests: POTENTIAL CONFLICT OF INTEREST: The authors have indicated they have no potential conflicts of interest to disclose., (Copyright © 2019 by the American Academy of Pediatrics.)

Purpose: We investigated whether chronic traffic-generated air pollution containing fine and ultrafine particulate matter is associated with reduced neurobehavioral performance and behavioral dysfunction in urban Ecuadorian schoolchildren. Also, we examined the effect of child hemoglobin and sociodemographic risk factors on these neurocognitive outcomes., Methods: A convenience sample of healthy children aged 8-14 years attending public schools were recruited in Quito, Ecuador. Child residential proximity to the nearest heavily trafficked road was used as a proxy for traffic-related pollutant exposure. These included high exposure (<100 m), medium exposure (100-199 m) and low exposure (≥ 200 m) from the nearest heavily trafficked road. The Behavioral Assessment and Research System (BARS), a computerized test battery assessing attention, memory, learning and motor function was used to evaluate child neurobehavioral performance. The Child Behavior Checklist (CBCL/6-18) was used to assess child behavioral dysfunction as reported by mothers. The data were analyzed using multiple linear regression., Results: Children with the highest residential exposure to traffic pollutants (< 100 m) had significantly longer latencies as measured by match to sample (b = 410.27; p = 0.01) and continuous performance (b = 37.90; p = 0.02) compared to those living ≥ 200 m away. A similar but non-significant association was observed for reaction time latency. Children living within 100 m of heavy traffic also demonstrated higher scores across all CBCL subscales although only the relationship with thought problems (p = 0.05) was statistically significant in the adjusted model., Conclusion: The study findings suggest that children living within 100 m of heavy traffic appear to experience subtle neurobehavioral deficits that may result from fine and ultrafine particulate matter exposure., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Background: Neurotoxic effects of high-level occupational exposure to manganese (Mn) are well established; however, whether lower-level environmental exposure to Mn in early life causes neurodevelopmental toxicity in children is unclear., Methods: A systematic literature review was conducted to identify and evaluate epidemiologic studies of specific Mn biomarkers assessed during gestation, childhood, or adolescence in association with neurodevelopmental outcomes, focusing on quantitative exposure-response estimates with specific endpoints that were assessed in multiple independent study populations. Study quality was evaluated using the revised RTI item bank and the Cochrane Risk of Bias tool, and the overall weight of epidemiologic evidence for causality was evaluated according to the Bradford Hill considerations., Results: Twenty-two epidemiologic studies were identified that estimated associations between early-life Mn biomarkers and neurodevelopmental outcomes. Seven of these studies provided adjusted estimates for the association with child intelligence assessed using versions of the Wechsler Intelligence Scales for Children; no other specific neurodevelopmental endpoints were assessed in more than three independent study populations each. Among the studies of child intelligence, five studies in four independent populations measured blood Mn, three studies measured hair Mn, and one measured dentin Mn. Overall, cross-sectional associations between Mn biomarkers and measures of child intelligence were mostly statistically nonsignificant but in a negative direction; however, the lone prospective cohort study found mostly null results, with some positive (favorable) associations between dentin Mn and child intelligence. Studies were methodologically limited by their cross-sectional design and potential for confounding and selection bias, as well as unaddressed questions on exposure assessment validity and biological plausibility., Conclusions: The statistical associations reported in the few studies of specific Mn biomarkers and specific neurodevelopmental endpoints do not establish causal effects based on the Bradford Hill considerations. Additional prospective cohort studies of Mn biomarkers and validated neurodevelopmental outcomes, and a better understanding of the etiologic relevance of Mn biomarkers, are needed to shed light on whether environmental exposure to Mn causes adverse neurodevelopmental effects in children., (Copyright © 2019 The Authors. Published by Elsevier B.V. All rights reserved.)

Imatinib is a preferred drug for pediatric Chronic Myeloid Leukemia (CML). Long-term use has inhibitory effects on other tyrosine kinase pathways causing off-target complications such as growth impairment. Our aim was to evaluate impact of long-term use on longitudinal growth in children with CML in Kerala. We hypothesized that the impact would be lesser compared to Northern India as Kerala has the lowest rates of underweight and stunting, with a high literacy rate and per capita income. Children ≤14 years of age, diagnosed with CML and received imatinib for at least 1 year were included. Girls >9 years of age and boys >11 years were considered pubertal. Height Z scores were derived using WHO AnthroPlus. Paired t test compared difference of Z scores in prepubertal and postpubertal age groups. Height Z scores were compared with mid-parental height and sibling height Z scores. Thirty-six children were included (M = 21; F = 15). Median duration of imatinib exposure was 84 months. Decrease in longitudinal growth affected children in both prepubertal and postpubertal age groups. Decrease in height Z scores was more in prepubertal age group when imatinib therapy was initiated ( p  = .0018). Of 10 patients currently above 19 years (of whom 8 were in pubertal age and 2 in prepubertal age at start of imatinib) none are stunted. Patient's height Z scores was lesser compared to sibling height Z scores ( p  = .027). Children on continuous imatinib showed a significant stunting when treatment was initiated during prepubertal age. There is a catch-up of growth as the final height reached is within normal limits of WHO reference values.

Background/aims: There is little information how rhGH treatment affects height in NS. This study aims to analyze data from the NS patients assembled in KIGS over 25 years., Patients/methods: Of 613 (389 m/224 f) NS patients documented, 476 (302 m/174 f) were treated for 1 year, 237 (160 m/77 f) of which served to develop a 1st year height velocity (HV) prediction algorithm. One-hundred and forty (74 m/66 f) had reached near adult height (NAH). Factors affecting NAH on rhGH were determined., Results: At the start of rhGH, the NAH groups were (median, m, f) 11.0 and 10.3 years, with a height SDS of -3.2 and -3.8 SDS (Prader), respectively. The total gain after 6.3 and 5.6 years on rhGH (0.27 and 0.30 mg/kg/week) was 1.2 and 1.3 SDS. Age at the start of rhGH (negative), height at the start of rhGH, rhGH dose, number of rhGH injections/wk and birth weight (all positive) explained 36% of the variability of 1st year HV. Height at the start of rhGH, 1st year growth on rhGH, birth weight, and gender explained 74% of the variability of NAH. Causes for rhGH treatment discontinuation and adverse events were also analyzed., Conclusion: rhGH treatment increases NAH in NS. Prediction algorithms may optimize treatment in the future., (© 2019 S. Karger AG, Basel.)

Background: Floating-Harbor syndrome (FHS) is a rare condition characterized by dysmorphic facial features, short stature, and expressive language delay., Objective: The aim of this study was to describe a cohort of patients with FHS and review the literature about the response to recombinant human growth hormone (rhGH) therapy., Methods: Anthropometric and laboratory data from 7 patients with FHS were described. The molecular diagnosis was established by multigene analysis. Moreover, we reviewed the literature concerning patients with FHS treated with rhGH., Results: All 7 patients were born small for gestational age. At first evaluation, 6 patients had a height standard deviation score (SDS) ≤-2 and 1 had short stature in relation to their target height. Bone age was usually delayed, which rapidly advanced during puberty. Nonspecific skeletal abnormalities were frequently noticed, and normal to elevated plasma IGF-I levels were observed in all except 1 patient with growth hormone deficiency. Information about 20 patients with FHS treated with rhGH was analyzed (4 from our cohort and 16 from the literature). The median height changes during the treatment period (approx. 2.9 years) were 1.1 SDS (range from -0.4 to 3.1). Nontreated patients had an adult height SDS of -4.1 ± 1.2 (n = 10) versus -2.6 ± 0.8 SDS (n = 7, p 0.012) for treated patients., Conclusion: We observed a laboratory profile compatible with IGF-1 insensitivity in some patients with FHS. Nevertheless, our study suggests that children with FHS may be considered as candidates for rhGH therapy. Further studies are necessary to establish the real benefit and safety of rhGH therapy in these patients., (© 2019 S. Karger AG, Basel.)

Background: Children born small for gestational age (SGA) with a poor adult height (AH) expectation benefit from treatment with GH and additional gonadotropin-releasing hormone analog (GnRHa). Because both SGA birth and GnRHa treatment might negatively influence cognition, health-related quality of life (HRQoL), and psychosocial functioning, we assessed these outcomes at AH., Methods: A randomized, dose-response GH study until AH involving 99 adolescents born SGA, of whom 61 children received 2 additional years of GnRHa treatment. At AH, the Wechsler Adult Intelligence Scale and TNO-AZL Adults Quality of Life questionnaire were administered to the study group. Additionally, the study group and 67 adolescents born SGA (19 GnRHa) from a second study group completed the Self-Perception Profile of Adolescents and Child/Adolescent Behavior Checklist at AH. Scores in GH-treated young adults with GnRHa treatment (GH/GnRHa group) were compared with GH-treated adolescents without GnRHa treatment (GH group) and a reference population., Results: Mean age (SD) at AH was 17.5 (1.2) and 17.4 (1.4) years in the GH/GnRHa and GH group, respectively. Intelligence quotient scores were similar in GH/GnRHa and GH groups (96.33 vs 92.47). HRQoL was similar between both groups and also when compared with the reference population, but the GH/GnRHa group had a significantly lower perception of cognitive functioning. Self-perception and problem behavior were similar in the GH/GnRHa and GH groups. AH did not correlate with HRQoL, self-perception, or problem behavior., Conclusion: Combined GH/GnRHa treatment has no long-term negative effects on cognition, HRQoL, self-perception, and behavior in early adulthood, compared with GH treatment only.

Background: Epiphyseal fusion (EF) marks the completion of longitudinal bone growth, a critical milestone monitored during treatment of skeletal growth and/or developmental disorders. Recently, a trend toward accelerated skeletal maturation in children has been documented. Because current methods for assessing skeletal maturation include children in their reference populations born as early as the 1930s, the timing of EF events in contemporary patients may differ substantially from those standards., Questions/purposes: (1) Do children today initiate the process of EF in the hand and wrist earlier than past generations on which maturity standards are based? (2) Do children today complete EF in the hand and wrist earlier than past generations on which maturity standards are based?, Methods: A total of 1292 children (665 males, 627 females) participating in the Fels Longitudinal Study, born between 1915 and 2006, were included in this retrospective, observational study. Each participant had between one and 39 serial left hand-wrist radiographs during childhood obtained specifically for research purposes. Main outcomes were the chronological age at the first sign of EF initiation (EF-I) and the first chronological age when EF was complete (EF-C) in the radius and ulna, and metacarpals and phalanges of the first, third, and fifth rays according to criteria of the Fels method. EF is a reliable metric with an average κ agreement statistic of 0.91. Penalized B-splines were used to model the changes in EF-I and EF-C ages and to identify changes across continuous birth years with major comparisons between children born in 1935 and 1995., Results: Approximately half of the epiphyses of the hand and wrist examined exhibited earlier EF-I and/or earlier EF-C in children born in 1995 compared with those born in 1935. The age at each milestone (EF-I and EF-C) decreased by as much as 6.7 and 6.8 months in males and 9.8 and 9.7 months in females, respectively. This change occurred gradually over the past century. The more proximal traits (EF of the distal radius, distal ulna, and metacarpals) were more likely to experience a shift in timing, whereas timing of EF in the phalanges remained relatively stable across birth years., Conclusions: A trend has occurred over the past century in the timing of EF, in both initiation and completion of the process, for many of the bones of the hand and wrist. Earlier EF reflects modern population advances in both skeletal and sexual maturation. Shifts in the timing of EF have the potential to influence treatment strategies for skeletal growth and/or developmental disorders such as scoliosis or leg length inequality, moving treatment windows to earlier ages. Earlier EF-I and EF-C identified in this study signals a need to reevaluate the timing of maturational milestones and current standards for skeletal assessment., Level of Evidence: Level II, prognostic study.

Purpose: Central nervous system (CNS) prophylaxis in the treatment of childhood acute lymphoblastic leukaemia (ALL) is routinely achieved through intrathecal chemotherapy (ITC). The presence of high level language deficits in older children who received CNS-directed ITC for ALL in early childhood is yet to be elucidated, with previous research suggesting that high level language deficits may appear later in ALL survivors' development at an age when these skills typically emerge., Method: A test battery covering foundational language skills and higher-order language skills was administered to five participants (aged 10-15 years) with a history of ITC for ALL. Conversion of each child's language performance scores to z scores allowed for clinical interpretation of data across the language areas tested., Result: Foundational language skills were, in general, of no clinical concern. Three of the five children presented with clinically impaired language skills in areas including resolving ambiguity, making inferences and composing novel sentences. Performance variation between the participants and within the individual participants was noted., Conclusion: Given the importance of early adolescent language abilities to academic and social development in late primary and secondary schooling, these preliminary findings suggest further research into emerging adolescent language abilities following ITC for ALL is warranted.

Attention-deficit hyperactivity disorder (ADHD) medication use has dramatically increased in youth worldwide. Recent prevalence data in some European countries show expanded use with one country now matching US usage. Still, substantial geographic differences by country remain regarding the extent to which children receive ADHD medications. These geographic differences by country raise research questions about which country's prevalence data represents appropriate medication use. We urgently need country level studies to contribute to our understanding of an appropriate prevalence of ADHD medication use., (© 2018 American Society for Clinical Pharmacology and Therapeutics.)

Rare genetically defined neurodevelopmental disorders with increased risk of autism have recently become an entry point for autism-related drug discovery. Through exploration of downstream effects of the pathological mutations, specific mechanistic pathways have been identified as dysregulated. The identification of shared mechanisms across forms of autism opens the door for the development of novel "mechanism-based therapeutics." However, confidence in the therapeutic mechanism does not diminish the need for well-designed clinical trials., (© 2018 American Society for Clinical Pharmacology and Therapeutics.)

Much remains unclear about the benefits and harms of methylphenidate for children and adolescents with attention-deficit/hyperactivity disorder (ADHD). Between 2012 and 2018, we conducted two Cochrane systematic reviews on methylphenidate for ADHD. This article explores the main findings in relation to evidence-based practice and our current understanding of ADHD., (© 2018 American Society for Clinical Pharmacology and Therapeutics.)

Attention-deficit/hyperactivity disorder (ADHD), the most common pediatric neurobehavioral disorder, frequently presents with coexisting reading disorders (RDs). Despite this, it is unclear whether medication improves symptoms and function in children with comorbid ADHD and RD. We present a systematic review of studies investigating the effects of ADHD medications on ADHD symptoms, academic outcomes, and neuropsychological measures in this important group., (© 2018 American Society for Clinical Pharmacology and Therapeutics.)

Drug treatment of attention-deficit hyperactivity disorder (ADHD) with stimulants, such as methylphenidate, has been widespread across the developed countries and is also becoming common in adults. However, this seemingly effective treatment is not without controversy on the evidence that supports their use. In addition, disparities in the frequency of its use across the world are tremendous. Although stimulants are one of the standard therapies for ADHD, autism spectrum disorder (ASD) lacks such a drug treatment. Focusing on neurogenetic conditions with defined genetic abnormalities, which have ASD as a co-existing symptom, a search for a druggable target of ASD continues., (© 2018 American Society for Clinical Pharmacology and Therapeutics.)

Epidemiological studies have demonstrated that air pollution particulate matter (PM) and adsorbed toxicants (organic compounds and trace metals) may affect child development already in utero. Recent studies have also indicated that PM may be a risk factor for neurodevelopmental disorders (NDDs). A pattern of increasing prevalence of attention deficit/hyperactivity disorder (ADHD) has been suggested to partly be linked to environmental pollutants exposure, including PM. Epidemiological studies suggest associations between pre- or postnatal exposure to air pollution components and ADHD symptoms. However, many studies are cross-sectional without possibility to reveal causality. Cohort studies are often small with poor exposure characterization, and confounded by traffic noise and socioeconomic factors, possibly overestimating the study associations. Furthermore, the mechanistic knowledge how exposure to PM during early brain development may contribute to increased risk of ADHD symptoms or cognitive deficits is limited. The closure of this knowledge gap requires the combined use of well-designed longitudinal cohort studies, supported by mechanistic in vitro studies. As ADHD has profound consequences for the children affected and their families, the identification of preventable risk factors such as air pollution exposure should be of high priority., (Copyright © 2018 Elsevier Inc. All rights reserved.)

During adolescence, the brain continues to undergo vital developmental processes. In turn, complex behavioral and cognitive skills emerge. Unfortunately, neurobiological development during adolescence can be influenced by environmental factors such as drug exposure. Engaging in drug use during adolescence has been a long-standing health concern, especially how it predicts or relates to drug using behavior later in life. However, recent findings suggest that other behavioral domains, such as learning and memory, are also vulnerable to adolescent drug use. Moreover, it is becoming increasingly apparent that deficits in learning and memory following adolescent drug use endure into adulthood, well after drug exposure has subsided. Although persistent effects suggest an interaction between drug exposure and ongoing development during adolescence, the exact acute and long-term consequences of adolescent drug exposure on substrates of learning and memory are not fully understood. Thus, this review will summarize human and animal findings on the enduring cognitive deficits due to adolescent drug exposure. Moreover, due to the fact that adolescents are more likely to consume drugs of abuse legally available to adults, this review will focus on alcohol, nicotine, and marijuana. Further, given the critical role of the frontal cortex and hippocampus in various learning and memory domains, the impact adolescent use of the previous listed drugs on the neurobiology within these regions will also be discussed., (© 2018 Mooney-Leber and Gould; Published by Cold Spring Harbor Laboratory Press.)

Purpose of Review: We present an overview of recent research in the inter-related areas of growth and pubertal development among adolescents with HIV. Growth deficits early in childhood can lead to delayed puberty, with subsequent effects on pubertal growth spurts and bone health., Recent Findings: Impaired growth remains a critical concern, particularly in low-resource settings, where stunting, wasting and underweight remain pervasive. Antiretroviral treatment (ART) initiation results in improved growth, with greatest growth recovery in the first years and more improvement in weight than in height. However, even years after ART initiation, growth deficits persist in low-resource settings (LRS), and adolescents appear at particularly increased risk. The high prevalence of stunting translates to delays in pubertal onset and sexual maturity. In contrast, HIV-infected adolescents in developed countries do not demonstrate persistent wasting, yet still have delayed pubertal development. Impaired growth increases the risk for mortality, virologic failure, and abnormal bone health, as well as increased depression and stigma., Summary: Early initiation of ART across all age groups regardless of immunological status is essential for restoring growth. Coordination of ART initiation, nutritional supplementation programs, and concurrent prophylaxis is required to ameliorate growth deficits and pubertal delays, particularly in LRS.

SmartTots (http://smarttots.org/) represents a public-private partnership between the International Anesthesia Research Society and the US Food and Drug Administration. Over the past 7 years, SmartTots has worked in collaboration with various stakeholders to determine whether anesthetic drugs have detrimental effects on the developing brain. SmartTots has funded clinical and preclinical studies, organized meetings, served as a repository of peer-reviewed information, and facilitated the development of consensus-based statements. Here, we report advances in the field of anesthetic neurotoxicity and provide an update on SmartTots' activities. Clinical studies have provided some reassurance that a brief exposure to anesthetic drugs does not cause overt, persistent cognitive deficits. New recommendations aim to increase the reproducibility and "clinical relevance" of data from studies of laboratory animals. Overall, the field has advanced substantially; however, it remains paramount to definitively resolve whether anesthetic drugs are neurotoxic to the immature brain. The results of SmartTots efforts will either ally unwarranted fears or substantially change pediatric anesthetic practice and prompt studies to identify neuroprotective strategies.

Objectives: Within populations, height is positively associated with economic success and in economically developed populations inversely associated with health. Recent studies also suggest air pollution may result in higher bone turnover markers among children, which may affect growth. However, few studies have investigated the effect of air pollution on height or growth rate. We therefore assessed the associations of several air pollutants with height at different ages., Methods: We simultaneously assessed associations of particulate matter with a diameter of 10 micrometers or less (PM 10 ), sulfur dioxide (SO 2 ), nitric oxide (NO), and nitrogen dioxide (NO 2 ) in utero, in infancy, and in childhood with height at different ages (∼9, ∼11, ∼13, and ∼15 years), in a population-representative birth cohort "Children of 1997" (n = 8327) from the developed non-Western setting of Hong Kong with relatively high air pollution and short children, using partial least square regression., Results: After considering multiple comparison, higher SO 2 in childhood was associated with shorter height at ∼13 years (-0.20 cm, 99% CI -0.32 to -0.06). This difference was not evident at ∼15 years., Conclusions: These observations suggest that air pollution may affect the trajectory of growth and development rather than final height, with corresponding implications for health in later life., (© 2017 Wiley Periodicals, Inc.)

Background/aims: Abuse of toluene products (e.g., glue-sniffing) primarily occurs during adolescence and has been associated with appetite suppression and weight impairments. However, the metabolic phenotype arising from adolescent inhalant abuse has never been fully characterised, and its persistence during abstinence and underlying mechanisms remain unknown., Methods: Adolescent male Wistar rats (post-natal day 27) were exposed to inhaled toluene (10,000 ppm) (n = 32) or air (n = 48) for 1 h/day, 3 days/week for 4 weeks, followed by 4 weeks of abstinence. Twenty air rats were pair-fed to the toluene group, to differentiate the direct effects of toluene from under-nutrition. Food intake, weight, and growth were monitored. Metabolic hormones were measured after exposure and abstinence periods. Energy expenditure was measured using indirect calorimetry. Adrenal function was assessed using adrenal histology and hormone testing., Results: Inhalant abuse suppressed appetite and increased energy expenditure. Reduced weight gain and growth were observed in both the toluene and pair-fed groups. Compared to the pair-fed group, and despite normalisation of food intake, the suppression of weight and growth for toluene-exposed rats persisted during abstinence. After exposure, toluene-exposed rats had low fasting blood glucose and insulin compared to the air and pair-fed groups. Consistent with adrenal insufficiency, adrenal hypertrophy and increased basal adrenocorticotropic hormone were observed in the toluene-exposed rats, despite normal basal corticosterone levels., Conclusions: Inhalant abuse results in negative energy balance, persistent growth impairment, and endocrine changes suggestive of adrenal insufficiency. We conclude that adrenal insufficiency contributes to the negative energy balance phenotype, potentially presenting a significant additional health risk for inhalant users., (© 2018 S. Karger AG, Basel.)

Adolescence is a significant period of physical, social, and emotional development, and is characterized by prominent neurobiological changes in the brain. The maturational processes that occur in brain regions responsible for cognitive control and reward seeking may underpin excessive consumption of palatable high fat and high sugar "junk" foods during adolescence. Recent studies have highlighted the negative impact of these foods on brain function, resulting in cognitive impairments and altered reward processing. The increased neuroplasticity during adolescence may render the brain vulnerable to the negative effects of these foods on cognition and behavior. In this review, we describe the mechanisms by which junk food diets influence neurodevelopment during adolescence. Diet can lead to alterations in dopamine-mediated reward signaling, and inhibitory neurotransmission controlled by γ-aminobutyric acid (GABA), two major neurotransmitter systems that are under construction across adolescence. We propose that poor dietary choices may derail the normal adolescent maturation process and influence neurodevelopmental trajectories, which can predispose individuals to dysregulated eating and impulsive behaviors., (© 2017 Wiley Periodicals, Inc.)

Carbohydrate-restricted diets are known for their impact on weight loss; however, research is still required to determine if low-carbohydrate diets are safe for adolescents. Carbohydrates directly stimulate an insulin response, and studies have recently shown that insulin and binding to respective insulin receptors (IRs) are critical in Kisspeptin (Kiss1) neuronal development. These neurons directly stimulate gonadotropin-releasing hormone, which activates the pituitary-gonadal axis during puberty. This information suggests that carbohydrate restriction may delay pubertal development in adolescents due to the impact on insulin and Kiss1 transcription. Studies have observed disturbed insulin metabolism in Type I Diabetics leading to delayed puberty, along with overfeeding stimulating early pubertal onset. Additionally, recent clinical trials bred female mice with IR deletions on Kiss1 neurons and observed delayed vaginal opening and estrus. Current animal research suggests low carbohydrate intake may delay pubertal onset, however additional research is required to determine outcome in human subjects., (Copyright© of YS Medical Media ltd.)

Background: There is marked variation in diabetes outcomes for children and adolescents across the UK. We used modelling techniques to examine the independent contributions of deprivation, ethnicity, insulin pump use, and health service use on HbA 1c trajectories across adolescence., Methods: Prospective data from a large UK Paediatric & Adolescent Diabetes Service on subjects with type 1 diabetes (T1D) aged 9-17 years from January 2008 to December 2013: 2560 HbA 1c datapoints were available on 384 patients [193 (50.4%) female]. Sequential multilevel growth models assessed the effects of sex, duration of diabetes, deprivation, ethnicity, insulin pump use, and health service use on HbA 1c . Growth mixture models were used to identify discrete HbA 1c trajectories across adolescence., Results: Mean clinic HbA 1c decreased from 2008 to 2013 by 0.122% (95% confidence interval: 0.034, 0.210; P = .007) per year. The optimal multilevel growth model showed mean HbA 1c increased with age (B = 0.414, P < .0001), and that mean HbA 1c was predicted by white/British ethnicity (B = -0.748, P = .004), clinic visits (B = 0.041, P = .04), and pump use (B = -0.568, P < .0001) but not deprivation. The optimal mixture model was a four trajectory group solution, with 45.1% in Good Control, 39.6% with Deteriorating Control, 6.5% with Rapidly Deteriorating Control, and 8.8% in Poor Control across adolescence. Only pump use predicted trajectory group membership, being protective against membership of all other trajectories compared with Good Control., Conclusions: Increasing uptake of insulin pumps and ensuring access to health services are likely to be the most effective means of reducing inequalities in outcomes of T1D in children and young people., (© 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)