Child development: risk factors for adverse outcomes in developing countries

Poverty and associated health, nutrition, and social factors prevent at least 200 million children in developing countries from attaining their developmental potential. We review the evidence linking compromised development with modifiable biological and psychosocial risks encountered by children from birth to 5 years of age. We identify four key risk factors where the need for intervention is urgent: stunting, inadequate cognitive stimulation, iodine deficiency, and iron deficiency anaemia. The evidence is also sufficient to warrant interventions for malaria, intrauterine growth restriction, maternal depression, exposure to violence, and exposure to heavy metals. We discuss the research needed to clarify the effect of other potential risk factors on child development. The prevalence of the risk factors and their effect on development and human potential are substantial. Furthermore, risks often occur together or cumulatively, with concomitant increased adverse effects on the development of the world's poorest children.

Inequality in early childhood: risk and protective factors for early child development

Inequality between and within populations has origins in adverse early experiences. Developmental neuroscience shows how early biological and psychosocial experiences affect brain development. We previously identified inadequate cognitive stimulation, stunting, iodine deficiency, and iron-deficiency anaemia as key risks that prevent millions of young children from attaining their developmental potential. Recent research emphasises the importance of these risks, strengthens the evidence for other risk factors including intrauterine growth restriction, malaria, lead exposure, HIV infection, maternal depression, institutionalisation, and exposure to societal violence, and identifies protective factors such as breastfeeding and maternal education. Evidence on risks resulting from prenatal maternal nutrition, maternal stress, and families affected with HIV is emerging. Interventions are urgently needed to reduce children's risk exposure and to promote development in affected children. Our goal is to provide information to help the setting of priorities for early child development programmes and policies to benefit the world's poorest children and reduce persistent inequalities.

Nurturing care: promoting early childhood development

The UN Sustainable Development Goals provide a historic opportunity to implement interventions, at scale, to promote early childhood development. Although the evidence base for the importance of early childhood development has grown, the research is distributed across sectors, populations, and settings, with diversity noted in both scope and focus. We provide a comprehensive updated analysis of early childhood development interventions across the five sectors of health, nutrition, education, child protection, and social protection. Our review concludes that to make interventions successful, smart, and sustainable, they need to be implemented as multi-sectoral intervention packages anchored in nurturing care. The recommendations emphasise that intervention packages should be applied at developmentally appropriate times during the life course, target multiple risks, and build on existing delivery platforms for feasibility of scale-up. While interventions will continue to improve with the growth of developmental science, the evidence now strongly suggests that parents, caregivers, and families need to be supported in providing nurturing care and protection in order for young children to achieve their developmental potential.

Issues in the timing of integrated early interventions: contributions from nutrition, neuroscience, and psychological research

A central issue when designing multidimensional biological and psychosocial interventions for children who are exposed to multiple developmental risks is identification of the age period(s) in which such interventions will have the strongest and longest lasting effects (sensitive periods). In this paper, we review nutritional, neuroscientific, and psychological evidence on this issue. Nutritional evidence is used to identify nutrient-sensitive periods of age-linked dimensions of brain development, with specific reference to iron deficiency. Neuroscience evidence is used to assess the importance of timing of exposures to environmental stressors for maintaining neural, neuroendocrine, and immune systems integrity. Psychological evidence illustrates the sensitivity of cognitive and social-emotional development to contextual risk and protective influences encountered at different ages. Evidence reviewed documents that the early years of life are a sensitive period when biological or psychosocial interventions or exposure to risk or protective contextual influences can produce unique long-term influences upon human brain, neuroendocrine, and cognitive or psychosocial development. However, the evidence does not identify the early years as the sole sensitive time period within which to have a significant influence upon development. Choice of age(s) to initiate interventions should be based on what outcomes are targeted and what interventions are used.

High-throughput bioanalytical LC/MS/MS determination of benzodiazepines in human urine: 1000 samples per 12 hours

The analytical capabilities of liquid chromatography tandem mass spectrometry for sensitive and highly selective determination of target compounds in complex biological samples makes it well suited for high-throughput analysis. We report the fast separation of six benzodiazepines isolated from human urine via selected reaction monitoring liquid chromatography/mass spectrometry using short dwell times to accommodate fast-eluting chromatographic peaks. The analytes were extracted from human urine samples along with their deuterium-labeled internal standards by a simple liquid-liquid extraction in 96-well plates. Using four autosamplers coupled to one chromatographic column and one tandem mass spectrometer operated in the turbo ion spray mode with positive ion detection, 1152 samples (12 96-well plates) were analyzed in less than 12 h. Through an electronic switching box designed and constructed in-house, the autosamplers were synchronized with the mass spectrometer so that injections were made as soon as the mass spectrometer was ready to collect data. Each run required 30 s to complete with another 7-8 s for the data system to load the next data file to be collected. Chromatographic integrity and ion current response remained relatively constant for the duration of the analyses. The results show acceptable precision and accuracy and demonstrate the feasibility of using fast separations with tandem mass spectrometry for high-throughout analysis of biological samples containing multiple analytes.

Electrospray device for coupling microscale separations and other miniaturized devices with electrospray mass spectrometry

A miniaturized ion sprayer device is described which is suitable for coupling with chip-based analytical separation devices, multiwell plates, or surfaces containing residues of prepared samples. Two versions of a similar device are described. A "microsprayer" device suitable for coupling to the terminal edge of a capillary electrophoresis (CE) chip is constructed from modified 1/16-in. HPLC fittings. This microsprayer employs a free-standing liquid junction formed via continuous delivery of a flow (2-6 microL/min) of suitable solvent which carries the CE effluent through a pneumatically assisted electrospray (ion spray) needle positioned in front of an atmospheric pressure ionization (API) mass spectrometer. A related but larger "minisprayer" device is also described which employs the same features as the microsprayer, but with an extended sampling capillary tube which can reach into the depths of 96-, 384-, and 1536-multiwell plates containing either sample solutions or dried sample residues. The minisprayer may be positioned in front of an API ion sampling orifice and the multiwell plate positioned stepwise from sample to sample for analysis of trace samples contained in the wells. The resulting infusion-ion spray mass spectrometric analyses can provide sequential analysis of previously prepared biological samples containing small drug compounds, proteins, and related compounds. This same device is also shown to be useful for sampling from a surface containing trace level compounds of biological interest. Results are shown that demonstrate microscale separations and selected ion monitoring (SIM) capillary electrophoresis/mass spectrometry (CE/MS) detection of berberine and palmatine using the microsprayer. SIM ion spray determination of a 2 ng/microL solution of berberine contained as a dry residue in the bottom of a 384-well plate as well as full-scan electrospray mass spectra for low-picomole levels of cytochrome c contained in a 1536-well microtiter plate are shown. The respective micro- and minisprayer devices provide a simple yet effective means of transferring trace-level samples either from a microscale or chip-based separation device as well as samples contained in multiwell plates which are increasingly employed in high-throughput applications in the pharmaceutical industry.

Temperament, Environment, and Six-Month Cognitive-Intellectual Development: A Test of the Organismic Specificity Hypothesis

The major question asked in the present study was whether temperamental differences mediated the infants' response to the early environment (organismic specificity). A corollary question involved the nature of the relationship between temperament and cognitive-intellectual development. Subjects were 100 six-month-old infants who were observed in their homes three times over a three-week period. Home observations were coded into social and physical environmental parameters. During this time period infant temperament and level of sensorimotor development were independently assessed. Canonical and univariate analyses revealed the following relationships: (1) Infants classified as temperamentally "easy" were more sensitive to environmental parameters than temperamentally "difficult" babies; when environmental influences were relevant for "difficult" infants, they tended to have a negative impact upon development. (2) Temperamental characteristics associated with difficultness were also associated with an inability to coordinate specific sensorimotor schemes. Implications of the above for our understanding of early environmental action were discussed.

Relation of maternal zinc nutriture to pregnancy outcome and infant development in an Egyptian village

Zinc nutriture of women living in a periurban Egyptian village was examined over the last 6 mo of pregnancy and the first 6 mo of lactation as one of several potential determinants of pregnancy outcome and infant development. Estimated bioavailable zinc intake was approximately 2 mg/d from diets high in phytate and fiber. Among numerous variables analyzed by multiple regression, early pregnancy weight (3 mo) and plasma zinc concentrations in the second trimester formed the best predictor model of birth weight, accounting for 39% of the variance. Bioavailable zinc intake during pregnancy was part of a profile of micronutrient intakes related to neonatal habituation behavior, a measure of early information processing. Performance on the Bayley motor test at 6 mo of age was negatively related to maternal intakes of plant zinc, phytate, and fiber, suggesting that zinc bioavailability was involved. Maternal dietary intake explained most of the variance observed in infant motor performance; however, predictive variance was amplified by the psychosocial context.

Relation of neonatal iron status to individual variability in neonatal temperament

The relation between indices of neonatal iron status and individual differences in neonatal temperament were investigated in a sample of 148 low-income Peruvian women and their newborn infants. Using cord blood, at birth we obtained measures of neonatal ferritin, serum iron, and hemoglobin. While neonates were still in the hospital, their behavior during a structured anthropometry examination was videotaped and subsequently coded on four temperament dimensions: activity level, negative emotionality, alertness, and soothability. The same dimensions were coded using a videotape obtained during a subsequent visit to the neonates' homes. Results indicated that lower levels of neonatal hemoglobin and serum iron were related to higher levels of negative emotionality and to lower levels of alertness and soothability. A similar pattern was found for ferritin, but only for females. For the most part, relations between neonatal iron measures and neonatal temperament were linear, operating across the full range of iron values. Our pattern of iron-temperament results could not be attributed to variation in family demographics, low birth weight, gestational age, maternal dietary intake, or markers of neonatal illness and maternal diabetes. Our findings are consistent with prior research with older infants relating iron deficiency to temperament. These results support the importance of increased research on the early functional-behavioral consequences of individual differences in iron status as well as on the mechanisms that underlie such consequences.

Design and applications of a self-aligning liquid junction-electrospray interface for capillary electrophoresis-mass spectrometry

A simple self-aligning liquid junction-electrospray interface for coupling a capillary electrophoresis (CE) system to an atmospheric pressure ionization (API) mass spectrometer (CE-MS) was developed. In contrast to previous liquid junction interfaces, the self-aligning liquid junction interface simplifies the precise alignment of the CE capillary and the sprayer needle and uses a positive make-up flow. Several capillary CE-MS applications were run using both the self-aligning liquid junction interface and the widely used sheath flow interface for comparison purposes. The electrospray stability of the self-aligning liquid junction interface is consistently better even when non-volatile electrolyte solutions are used. At first, some band broadening was obtained with the self-aligning liquid junction interface. Experiments with different CE buffer systems suggested that this band broadening was caused by the materials used in constructing the interface. By using a more inert material for the sprayer needle, the self-aligning liquid junction exhibits excellent electrophoretic resolution, comparable sensitivity, and higher signal-to-noise ratios when run under the same conditions as the sheath flow interface.

Kinetic monitoring of enzymatic reactions in real time by quantitative high-performance liquid chromatography-mass spectrometry

The study of enzyme kinetics under steady-state conditions represents a common and very useful method for investigating the mechanisms of enzymatic reactions. We report the use of mass spectrometry (MS) coupled with HPLC for the kinetic analysis of enzymatic reactions in real time. The hydrolysis of dinucleotides with bovine pancreatic ribonuclease A (RNase A) and the substrate-specific hydrolysis of lactose with beta-galactosidase can be monitored using ion-spray (pneumatically assisted electrospray) mass spectrometry as a sensitive and specific detector for the native substrates. The resulting data can be used to calculate both KM and Vmax for each system. Kinetic parameters obtained for RNase A and beta-galactosidase paralleled those obtained by conventional techniques. These findings suggest the possibility of developing alternative techniques, based on mass spectrometric detection, for performing kinetic analyses of enzymatic processes where no simple spectrophotometric assay is feasible. In addition to enabling the determination of kinetic parameters for authentic substrates, and not chromogenic analogs, such assays would also be useful in situations where very high sensitivity and specificity are desired.

Determinants of pregnancy outcome and newborn behavior of a semirural Egyptian population

Several potential determinants of birth weight and neonatal behavioral organization, ie, maternal anthropometry, food intake (energy, protein, and plant- and animal-source foods), morbidity, and household socioeconomic status, were followed systematically in a semirural Egyptian population during greater than or equal to 6 mo of pregnancy. In early pregnancy mothers were generally normal weight to moderately overweight. Their mean energy intake, largely from plant sources, was approximately 8.37 MJ/d (2000 kcal/d) during trimesters 2 and 3. Early (3 mo) pregnancy weight and weight gain during trimesters 2 and 3 were significantly positively related to birth weight Z scores. The best predictor model examined for birth weight included early pregnancy weight, weight gain, and length of gestation (R2 = 0.45). Early pregnancy weight and maternal intake of animal-source foods were significant positive predictors of the newborn's orientation and habituation behavior, respectively. Habituation and orientation measures assess the infant's early ability to process information.

Vitamin B-6 status of Egyptian mothers: relation to infant behavior and maternal-infant interactions

Functional consequences of marginal maternal vitamin B-6 status for behavior of the neonate and for mother-infant interactions at age 3-6 mo were assessed by a double-blind procedure. In 27 of 70 Egyptian village women studied, vitamin B-6 concentration of their milk was considered indicative of poor maternal vitamin B-6 nutriture. Neonatal behavior, quantified by the Brazelton Neonatal Behavioral Assessment Scale, showed that consolability, appropriate build-up to a crying state, and response to aversive stimuli were significantly correlated with maternal vitamin B-6 nutriture. Naturalistic observational procedures, used twice monthly with infants aged 3-6 mo, indicated that mothers assessed as having marginal vitamin B-6 status were less responsive to their infants' vocalizations, showed less effective intervention to infant distress, and were more likely to use older siblings as care-givers than were mothers of better vitamin status. We conclude that vitamin B-6 was a factor influencing both the behavior of the mother and her infant.

Maternal education and intelligence predict offspring diet and nutritional status

The traditional assumption that children's nutritional deficiencies are essentially due either to overall food scarcity or to a lack of family resources to purchase available food has been increasingly questioned. Parental characteristics represent 1 type of noneconomic factor that may be related to variability in children's diets and nutritional status. We report evidence on the relation of 2 parental characteristics, maternal education level and maternal intelligence, to infant and toddler diet and nutritional status. Our sample consisted of 241 low-income Peruvian mothers and their infants assessed from 3 to 12 mo, with a further follow-up of 104 of these infants at 18 mo of age. Using a nonexperimental design, we related measures of level of maternal education, maternal intelligence, and family socioeconomic status to infant anthropometry, duration of exclusive breast-feeding, adequacy of dietary intake, and iron status. Results indicated unique positive relations between maternal education level and the extent of exclusive breast-feeding. Significant relations between maternal education and offspring length were partially mediated by maternal height. There also were unique positive relations between maternal intelligence and quality of offspring diet and hemoglobin level. All findings remained significant even after controlling for family socioeconomic characteristics. This pattern of results illustrates the importance of parental characteristics in structuring the adequacy of offspring diet. Maternal education and intelligence appear to have unique influences upon different aspects of the diet and nutritional status of offspring.

Relation of mild-to-moderate malnutrition to human development: correlational studies

The present review focuses on the relation to human behavior and development of anthropometric or dietary indexes of mild-to-moderate malnutrition. The primary goal of the review is to integrate previous research findings with current findings from correlational studies conducted over the past decade. From this integration, the following conclusions may be drawn: 1) Chronic, mild postnatal malnutrition is associated with a variety of cognitive and behavioral deficits across the life span. The role of prenatal malnutrition in this process is less clear. 2) To understand the role chronic mild malnutrition plays in behavior and development, it is necessary to move beyond protein-calorie deficits to consider the role of intake of animal source foods and specific micronutrients such as iron, zinc and B vitamins. 3) Chronic mild malnutrition is embedded in a host of other biological and psychosocial risk factors. As a result, chronic mild malnutrition appears to be a necessary but insufficient condition for producing behavioral deficits. 4) The salience of chronic mild malnutrition as a risk factor is accentuated when other psychosocial-contextual risk factors are also present or when multiple low-level nutrient deficits are interacting. Suggestions for future research directions include an emphasis on interactions between nutrients and between specific psychosocial and nutritional risk factors; the ways in which individual (e.g., gender) or cultural characteristics can moderate nutrition development relations; and a broader range of populations, such as sibling or elderly caregivers, and outcome variables, such as social-emotional development, temperament and mental health.