Associations Among Infant Iron Deficiency, Childhood Emotion and Attention Regulation, and Adolescent Problem Behaviors.

This study examined whether iron deficiency (ID) in infancy contributes to problem behaviors in adolescence through its influence on poor regulatory abilities in childhood. Chilean infants (N = 1,116) were studied when there was no national program for iron fortification (1991-1996), resulting in high rates of ID (28%) and iron-deficiency anemia (IDA, 17%). Infants (54% male) were studied at childhood (Mage  = 10 years) and adolescence (Mage  = 14 years). IDA in infancy was related to excessive alcohol use and risky sexual behavior in adolescence through its effect on poor emotion regulation in childhood. Attentional control deficits at age 10 were also related to both infant IDA and heightened risk taking in adolescence. Findings elucidate how poor childhood regulatory abilities associated with infant IDA compromise adjustment in adolescence.

Iron supplementation in infancy contributes to more adaptive behavior at 10 years of age.

Most studies of behavioral/developmental effects of iron deficiency anemia (IDA) or iron supplementation in infancy have found social-emotional differences. Differences could relate to behavioral inhibition or lack of positive affect and altered response to reward. To determine long-term behavioral effects, the study was a follow-up of a randomized controlled trial of behavioral/developmental effects of preventing IDA in infancy. Healthy Chilean infants free of IDA at age 6 mo were randomly assigned to iron supplementation or no added iron (formula with iron/powdered cow milk, vitamins with/without iron) from ages 6 to 12 mo. At age 10 y, 59% (666 of 1123) and 68% (366 of 534) of iron-supplemented and no-added-iron groups were assessed. Social-emotional outcomes included maternal-reported behavior problems, self-reported behavior, examiner ratings, and video coding of a social stress task and gamelike paradigms. Examiners rated the iron-supplemented group as more cooperative, confident, persistent after failure, coordinated, and direct and reality-oriented in speech and working harder after praise compared with the no-added-iron group. In a task designed to elicit positive affect, supplemented children spent more time laughing and smiling together with their mothers and started smiling more quickly. In the social stress task they smiled and laughed more and needed less prompting to complete the task. All P values were <0.05; effect sizes were 0.14-0.36. There were no differences in behaviors related to behavioral inhibition, such as anxiety/depression or social problems. In sum, iron supplementation in infancy was associated with more adaptive behavior at age 10 y, especially in affect and response to reward, which may improve performance at school and work, mental health, and personal relationships.

PM2.5 mass and species trends in Santiago, Chile, 1998 to 2010: the impact of fuel-related interventions and fuel sales.

UNLABELLED: Improving air quality in Santiago has been a high priority for the Chilean government. In this paper we examine trends of fine particulate matter (PM2.5) mass and species concentrations during the period 1998 to 2010 and explore the impact of fuel-related interventions and fuel sales on concentration changes. Smoothing spline functions were utilized to characterize and account for nonlinear relationships between pollutant concentrations and different parameters. Meteorology-adjusted PM2.5 concentrations were lower by 21.8 microg/m3 in 2010 compared to 1998. In this model, wind speed was the most important determinant of PM2.5 levels. A decrease in 24-hr average wind speed below 1.0 m/s was associated with a significant increase in daily PM2.5 levels, indicating a high sensitivity of PM2.5 concentrations to the accumulation of local emissions. The same regression model framework was applied to examine the trends of lead, bromine, and sulfur concentrations. Removal of lead and bromine from gasoline achieved dramatic decreases in their atmospheric concentrations. Nonetheless, both elements continue to persist, likely in the form of PbBrCl. The reduction of diesel sulfur content from 1,500 to 50 ppm corresponded to a 32% decrease in particulate sulfur levels. Lastly, a surge in PM2.5 was observed in 2005-2008. Further regression analyses suggested this was prompted by a rise in monthly petroleum-based fuel sales. IMPLICATIONS: In this paper, we elucidate meteorology-adjusted trends of PM2.5 mass and species concentrations in Santiago and assess the efficacy of fuel-related interventions, such as the removal of lead from gasoline and reduction of sulfur content in diesel. In addition, we explore the impact of fuel sales on PM2.5 trends. Given that fuel consumption is likely to increase further in this rapidly growing city, understanding its impact on PM2.5 trends can inform future air quality control efforts in Santiago.

Parental perceptions of neighborhood effects in Latino Comunas: the script of "the Delinquent" in understanding drug use, violence, and social disorganization.

OBJECTIVES: To obtain rich information about how adult Latinos living in high-poverty/high-drug use neighborhoods perceive and negotiate their environment. METHODS: In 2008, 13 adult caregivers in Santiago, Chile, were interviewed with open-ended questions to ascertain beliefs about neighborhood effects and drug use. ANALYSIS: Inductive analysis was used to develop the codebook/identify trends. DISCUSSION: Residents externalized their understanding of drug use and misuse by invoking the concept of delinquent youth. A typology of their perceptions is offered. Learning more about residents' circumstances may help focus on needs-based interventions. More research with Latino neighborhoods is needed for culturally competent models of interventions.

Relationship between Discordance in Parental Monitoring and Behavioral Problems among Chilean Adolescents.

This study investigated the role of discrepancies between parent and youth reports of perceived parental monitoring in adolescent problem behaviors with a Chilean sample (N= 850). Higher levels of discordance concerning parental monitoring predicted greater levels of maladaptive youth behaviors. A positive association between parent-youth discordance and externalizing problems indicated that large adult-youth disagreement in parental monitoring may impose a great risk, despite protective efforts of parental monitoring. Although the direct relationship between parental monitoring and youth internalizing behaviors was not significant, parent-youth incongruence in monitoring was associated with greater levels of internalizing behaviors. Therefore, differing assessments of parental behaviors, as an indicator of less optimal family functioning, may provide important information about youth maladjustment and may potentially provide a beginning point for family-focused intervention.

Sexual intercourse among adolescents in Santiago, Chile: a study of individual and parenting factors.

OBJECTIVE: to examine a range of individual, parenting, and family factors associated with sexual intercourse among a community sample of youth and their families in Santiago, Chile. METHODS: Data were taken from the Santiago Longitudinal Study conducted in January 2008-November 2009. Participants were 766 youth (mean age = 14.03 years, 51% male) from municipalities of low- to mid-socioeconomic status. Variables included emotional and behavioral subscales from the Child Behavior Checklist's Youth Self Report, parental monitoring, family involvement, parental control and autonomy, relationship with each parent, and sexual activity. Bivariate and multivariate logistic regression models were used to examine the odds of sexual intercourse initiation. RESULTS: seventy (9.14%) youth reported having had sex in their lifetime; the average age of first sexual intercourse among this group was 13.5 years (Standard Deviation [SD] = 1.74) for males and 14.08 (SD = 1.40) for females. Having sex was inversely associated with withdrawn-depressed symptoms (Odds Ratio [OR] = 0.84, Confidence Interval [CI] = 0.72-0.97), but positively associated with somatic complaints (OR = 1.20, CI = 1.04-1.38) and rule breaking behavior (OR = 1.21, CI = 1.08-1.36), after adjusting for demographic and other individual and parenting variables. The majority (80%) of the youth who had had sex reported using protection at the time of last intercourse. CONCLUSIONS: findings highlight the role that mental health problems-some of them not commonly associated with onset of sexual activity-may play in a youth's decision to have sex. The potential protective effects of several parenting and family characteristics disappeared with youth age and youth behavioral problems.

Higher infant blood lead levels with longer duration of breastfeeding.

OBJECTIVE: To determine whether longer breastfeeding is associated with higher infant lead concentrations. STUDY DESIGN: Data were analyzed from 3 studies of developmental effects of iron deficiency in infancy: Costa Rica (1981-1984), Chile (1991-1996), and Detroit (2002-2003). The relation between duration of breastfeeding and lead levels was assessed with Pearson product-moment or partial correlation coefficients. RESULTS: More than 93% of the Costa Rica and Chile samples was breastfed (179 and 323 breastfed infants, respectively; mean weaning age, 8-10 months), as was 35.6% of the Detroit sample (53 breastfed infants; mean weaning age, 4.5 months). Lead concentrations averaged 10.8 microg/dL (Costa Rica, 12-23 months), 7.8 microg/dL (Chile, 12 months), and 2.5 microg/dL (Detroit, 9-10 months). Duration of breastfeeding as sole milk source and total breastfeeding correlated with lead concentration in all samples (r values = 0.14-0.57; P values = .06-<.0001). CONCLUSIONS: Longer breastfeeding was associated with higher infant lead concentration in 3 countries, in 3 different decades, in settings differing in breastfeeding patterns, environmental lead sources, and infant lead levels. The results suggest that monitoring lead concentrations in breastfed infants be considered.

Linear and ponderal growth trajectories in well-nourished, iron-sufficient infants are unimpaired by iron supplementation.

Iron deficiency remains the most common nutritional deficiency worldwide and supplementation is recommended during periods of high risk, including infancy. However, questions have been raised about possible adverse effects of iron on growth in iron-sufficient (IS) infants and the advisability of across-the-board iron supplementation. This study examined whether short- or long-term growth was impaired in IS infants who received iron supplementation. From a longitudinal study of healthy, breast-fed, low- to middle-income Chilean infants randomly assigned to iron supplementation or usual nutrition at 6 or 12 mo, we retrospectively identified infants meeting criteria for iron sufficiency at the time of random assignment (n = 273). Using multilevel analysis, ponderal and linear growth were modeled before, during, and after iron supplementation up to 10 y in 3 comparisons: 1) iron supplementation compared with usual nutrition from 6 to 12 mo; 2) iron supplementation compared with usual nutrition from 12 to 18 mo; and 3) 15 mg/d of iron as drops compared with iron-fortified formula (12 mg/L). Growth trajectories did not differ during or after supplementation indicating no adverse effect of iron in any comparison. These results suggest that, at least in some environments, iron does not impair growth in IS infants.

A Molecular Imprinted Polymer as a Flow-Through Optical Sensor for Oxazepam.

A flow-through optosensing system for oxazepam recognition with fluorescence detection was performed by means of a molecular imprinted polymer based on its acid hydrolysis product, 2-amino-5-chlorobenzophenone. The synthesis was conducted via a noncovalent imprinting methodology, using methacrylic acid as a functional monomer and ethylene glycol dimethacrylate as a cross-linking agent. Hydrolysis (types and concentration of acids), polymer retention capacity, binding properties, and elution (selectivity and reversibility) conditions were optimized. The selected molecular imprinted polymer had a molar ratio composition of 1 : 6 : 45 (template : functional monomer : cross-linker). The proposed method was applied to the determination of oxazepam in a pharmaceutical formulation. External standard calibration, standard additions calibration, and Youden's calibration were carried out in order to evaluate constant and proportional errors due to the matrix. The developed metabolite-based recognition system for benzodiazepines is an innovative procedure that could be followed in routine and quality control assays.

Risk of stillbirth among Zambian women with a prior cesarean delivery.

OBJECTIVE: Cesarean delivery (CD) may be associated with stillbirth in future pregnancies. We investigated prior CD as a risk factor for stillbirth in Lusaka, Zambia. METHODS: We conducted a retrospective cohort analysis of women with only one prior pregnancy who delivered between February 1, 2006, and May 31, 2013. We analysed data from the Zambia Electronic Perinatal System. Maternal and infant characteristics were analyzed for association with stillbirth using Pearson's χ2 test or the Wilcoxon rank-sum test. We calculated risk ratios for the relationship between stillbirth (antepartum vs intrapartum) and prior CD, with a log Poisson model to adjust for confounding. RESULTS: Of 57 320 women in our cohort, 1933 (3.4%) reported a prior CD. There were 1012 (1.8%) stillbirths in the no prior CD group and 81 (4.2%) in the prior CD group (P<0.001). In multivariate models adjusting for stillbirth risk factors, prior CD was associated with antepartum (adjusted risk ratio 1.56, 95% confidence interval 1.08-2.24) and intrapartum (adjusted risk ratio 3.26, 95% confidence interval 2.40-4.42) stillbirth compared with no prior CD. The difference between groups was most apparent at 36-37 weeks' gestation (log-rank P<0.001). CONCLUSION: Prior CD was associated with increased risk of stillbirth. Improved monitoring during labor and safe methods for induction are urgently needed in low-resource settings.

The Zambian Preterm Birth Prevention Study (ZAPPS): Cohort characteristics at enrollment.

Background:Sub-Saharan Africa bears a disproportionate burden of preterm birth and other adverse outcomes. A better understanding of the demographic, clinical, and biologic underpinnings of these adverse outcomes is urgently needed to plan interventions and inform new discovery.  Methods:The Zambian Preterm Birth Prevention Study (ZAPPS) is a prospective observational cohort established at the Women and Newborn Hospital (WNH) in Lusaka, Zambia. We recruit pregnant women from district health centers and the WNH and offer ultrasound examination to determine eligibility. Participants receive routine obstetrical care, lab testing, midtrimester cervical length measurement, and serial fetal growth monitoring. At delivery, we assess gestational age, birthweight, vital status, and sex and assign a delivery phenotype. We collect blood, urine, and vaginal swab specimens at scheduled visits and store them in an on-site biorepository. In September 2017, enrollment of the ZAPPS Phase 1 - the subject of this report - was completed. Phase 2 - which is limited to HIV-uninfected women - reopened in January 2018.  Results:Between August 2015 and September 2017, we screened 1784 women, of whom 1450 (81.2%) met inclusion criteria and were enrolled. The median age at enrollment was 27 years (IQR 23-32) and thee median gestational age was 16 weeks (IQR 13-18). Among parous women (N=866; 64%), 21% (N=182) reported a prior miscarriage, 49% (N=424) reported a prior preterm birth, and 13% (N=116) reported a prior stillbirth. The HIV seroprevalence was 24%. Discussion:We have established a large cohort of pregnant women and newborns at the WHN to characterize the determinants of adverse birth outcomes in Lusaka, Zambia. Our overarching goal is to elucidate biological mechanisms in an effort to identify new strategies for early detection and prevention of adverse outcomes. We hope that findings from this cohort will help guide future studies, clinical care, and policy.

Breast-feeding and mental and motor development at 51/2 years.

OBJECTIVE: Breast-feeding is associated with better child development outcomes, but uncertainty remains primarily due to the close relationship between breast-feeding and socioeconomic status. This study assesses the issue in a low socioeconomic status sample where breast-feeding was close to universal. METHODS: Seven hundred eighty-four Chilean children were followed longitudinally from infancy. All but four were initially breastfed, 40% nursed beyond 12 months, and infant growth was normal. Child development was assessed at 5(1/2) years by a cognitive, language, and motor test battery. The duration of breast-feeding as the sole milk source was analyzed as a continuous variable, adjusting for a comprehensive set of background factors. RESULTS: The relationship between breast-feeding and most 5(1/2)-year developmental outcomes was nonlinear, with poorer outcome for periods of breast-feeding as the sole milk source for <2 months or >8 months--statistically significant for language, motor, and one comprehensive cognitive test, with a suggestive trend for IQ. CONCLUSIONS: The observed nonlinear relationships showed that breast-feeding as the sole milk source for <2 months or >8 months, compared with 2-8 months, was associated with poorer development in this sample. The latter finding requires replication in other samples where long breast-feeding is common and socioeconomic status is relatively homogeneous.

Indirect fluorometric determination of diclofenac sodium.

A simple and easy method of analysis for diclofenac sodium is reported. A spectrofluorometric method for the microdetermination of diclofenac sodium has been developed through its reaction with cerium(IV) in an acidic solution and measurement of the fluorescence of the Ce(III) ions produced. Under the optimum experimental conditions for the oxidation reaction, 1.0 M H2SO4 with 90 min of heating time (100 degrees C), the range of application is 124.3-600 ng mL(-1) and the limit of detection is 72.7 ng mL(-1). The proposed method was applied to the determination of diclofenac sodium in pharmaceutical tablets. The results of the analysis show a good agreement with those obtained by the official USP 27 HPLC method.

Parenthood linked to new onset overweight or obesity among Chilean adolescents.

OBJECTIVE: To determine whether early parenthood is associated with the onset of overweight/obesity during adolescence. METHODS: Weight status changes between ages 16 and 21 years were measured in 270 Chilean youths. Parenthood by age 21 was assessed by interview. RESULTS: Sixty-three youths became overweight/obese between ages 16 and 21 years (23%), and 24% (n=65) of the total sample were parents by age 21. Bearing a child by age 21 was associated with a two-fold risk of becoming newly overweight or obese (OR=2.6, CI: 1.1, 5.9, p<0.05). Earlier internalizing problems were also associated with the development of overweight/obesity in young mothers. CONCLUSION: Weight status changes from normal to overweight or obese were more likely to occur among young parents than non-parents. This has implications for adolescents' future health given their likelihood of having subsequent pregnancies and the known risks of increased weight at each pregnancy.

Leptin status in adolescence is associated with academic performance in high school: a cross-sectional study in a Chilean birth cohort.

OBJECTIVE: Leptin is a pleiotropic hormone associated with learning and memory via brain receptors. However, elevated plasma leptin levels may impair cognitive and memory functions. Since individual differences in memory performance affect students' ability to learn, we aimed to study the relation between leptin status in adolescence and school performance. DESIGN AND SETTING: We studied 568 adolescents aged 16-17 years from Santiago. A cross-sectional analysis was carried out on a birth cohort conducted in Santiago (Chile). PRIMARY AND SECONDARY OUTCOME MEASURES: We measured serum leptin concentration using an enzyme-linked immunosorbent assay. Cut-offs from the Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) Study for 16-year-olds were used to define abnormally high leptin levels (hyperleptinaemia). Academic performance was measured using high-school grades and grade point average (GPA). Data were collected in 2009-2012; data analysis was performed in 2014. RESULTS: 15% of participants had hyperleptinaemia. They had significantly lower school grades and GPA compared with participants with normal leptin levels (eg, GPA mean difference=33.8 points). Leptin levels were negative and significantly correlated with school grades in 9th, 10th and 12th. Similarly, it was negatively correlated with high-school GPA. After controlling for health, sociodemographic and education confounders, the chances of having a performance ≥75th centile in students having hyperleptinaemia were 32% (95% CI 0.19% to 0.89%) that of students having normal serum leptin concentration. CONCLUSIONS: In high school students, abnormally high levels of leptin were associated with poorer academic performance. These findings support the idea of a relationship between leptin and cognition. Further research is needed on the cognitive effects of leptin in younger populations.

Socioeconomic Status and Internalizing Symptoms in Chilean Children: Does Reserve Capacity Matter?

Informed by the reserve capacity model, we examined pathways between socioeconomic status (SES) and internalizing symptoms (IS) in 1119 Chilean 10-year-olds. Mediators included parental disciplinary style and reserve capacity resources (RCR), namely home environment, parent-child engagement, and self-esteem, and conduct problems. Using structural equation modeling, the model was stratified by gender. For boys, the SES-IS relationship was mediated by the home environment and parental disciplinary style. For girls, the SES-IS relationship was mediated by the home environment, parent-child engagement, self-esteem, and conduct problems. Findings suggest different RCR may protect against IS in a sample of Chilean children.

Developmental scores at 1 year with increasing gestational age, 37-41 weeks.

OBJECTIVE: To examine the relationship between gestational age and mental and psychomotor development scores in healthy infants born between 37 and 41 weeks. METHODS: The cohort included 1562 participants enrolled during infancy in an iron deficiency anemia preventive trial in Santiago, Chile. All participants were healthy, full-term (37-41 weeks) infants who weighed 3 kg or more at birth. Development at 12 months was assessed using the Bayley Scales of Infant Development. Using generalized linear modeling, we analyzed the association between gestational age and 1-year-old developmental status, taking into account potential confounders including birth weight percentile, gender, socioeconomic status, the home environment, iron status, and iron supplementation. RESULTS: For each additional week of gestation, the Mental Development Index increased by 0.8 points (95% confidence interval = 0.2-1.4), and the Psychomotor Development Index increased by 1.4 points (95% confidence interval = 0.6-2.1) controlling for birth weight percentile, gender, socioeconomic status, and home environment. CONCLUSIONS: In a large sample of healthy full-term infants, developmental scores obtained using the Bayley Scales of Infant Development at 12 months increased with gestational age (37-41 weeks). There is increasing evidence that birth at 39 to 41 weeks provides developmental advantages compared with birth at 37 to 38 weeks. Because cesarean deliveries and early-term inductions have increased to 40% of all births, consideration of ongoing brain development during the full-term period is an important medical and policy issue.

The Role of Peers and Parents in Predicting Alcohol Consumption among Chilean Youth.

This study estimated marginal associations of parent- and peer-related measures to examine the different patterns of lifetime ever-use and frequency of alcohol consumption among adolescents in Santiago, Chile (N=918). Probit and negative binomial models were applied to predict the probability of ever-use and the average number of drinks consumed in the past 30 days. Results supported the profound role of peer-relationships in the development of youth drinking behavior. Particularly, peer pressure seemed more important in predicting alcohol ever-use than the frequency of drinking. Simultaneously, parents, especially fathers, played a crucial protective role. Policies aimed at preventing various drinking patterns may be more effective if they not only focus on the targeted adolescents, but also reach out to peers and parents.

Iron-fortified vs low-iron infant formula: developmental outcome at 10 years.

OBJECTIVE: To assess long-term developmental outcome in children who received iron-fortified or low-iron formula. DESIGN: Follow-up at 10 years of a randomized controlled trial (1991-1994) of 2 levels of formula iron. Examiners were masked to group assignment. SETTING: Urban areas around Santiago, Chile. PARTICIPANTS: The original study enrolled healthy, full-term infants in community clinics; 835 completed the trial. At 10 years, 473 were assessed (56.6%). INTERVENTION: Iron-fortified (mean, 12.7 mg/L) or low-iron (mean, 2.3 mg/L) formula from 6 to 12 months. MAIN OUTCOME MEASURES: We measured IQ, spatial memory, arithmetic achievement, visual-motor integration, visual perception, and motor functioning. We used covaried regression to compare iron-fortified and low-iron groups and considered hemoglobin level before randomization and sensitivity analyses to identify 6-month hemoglobin levels at which groups diverged in outcome. RESULTS: Compared with the low-iron group, the iron-fortified group scored lower on every 10-year outcome (significant for spatial memory and visual-motor integration; suggestive for IQ, arithmetic achievement, visual perception, and motor coordination; 1.4-4.6 points lower; effect sizes, 0.13-0.21). Children with high 6-month hemoglobin levels (> 12.8 g/dL [to convert to grams per liter, multiply by 10]) showed poorer outcome on these measures if they received iron-fortified formula (10.7-19.3 points lower; large effect sizes, 0.85-1.36); those with low hemoglobin levels (< 10.5 g/dL) showed better outcome (2.6-4.5 points higher; small but significant effects, 0.22-0.36). High hemoglobin levels represented 5.5% of the sample (n = 26) and low hemoglobin levels represented 18.4% (n = 87). CONCLUSION: Long-term development may be adversely affected in infants with high hemoglobin levels who receive 12.7 mg/L of iron-fortified formula. Optimal amounts of iron in infant formula warrant further study.

Predictors of discordance among Chilean families.

Parent-youth agreement on parental behaviors can characterize effective parenting. Although discordance in families may be developmentally salient and harmful to youth outcomes, predictors of discordance have been understudied, and existing research in this field has been mostly limited to North American samples. This paper addressed this literature gap by using data from a community-based study of Chilean adolescents. Analysis was based on 1,068 adolescents in Santiago, Chile. The dependent variable was discordance which was measured by the difference between parent and youth's assessment of parental monitoring. Major independent variables for this study were selected based on previous research findings that underscore youth's developmental factors, positive parental and familial factors and demographic factors. Descriptive and multivariate analyses were conducted to examine the prevalence and associations between youth, parental and familial measures with parent-youth discordance. There was a sizable level of discordance between parent and youth's report of parental monitoring. Youth's gender and externalizing behavior were significant predictors of discordance. Warm parenting and family involvement were met with decreases in discordance. The negative interaction coefficients between parental warmth and youth's gender indicated that positive parental and familial measures have a greater effect on reducing parent-youth discordance among male youths. Results support the significance of positive family interactions in healthy family dynamics. Findings from this study inform the importance of services and interventions for families that aim to reduce youth's problem behavior and to create a warm and interactive family environment.