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1.  Are preterm newborns who have relative hyperthyrotropinemia at increased risk of brain damage? 
We sought to disentangle the contributions of hyperthyrotropinemia (an indicator of thyroid dysfunction) (HTT) and intermittent or sustained systemic inflammation (ISSI) to structural and functional indicators of brain damage.
We measured the concentrations of TSH on day 14, and of 25 inflammation-related proteins in blood collected during the first 2 postnatal weeks from 786 infants born before the 28th week of gestation who were not considered to have hypothyroidism. We defined hyperthyrotropinemia (HTT) as a TSH concentration in the highest quartile for gestational age on postnatal day 14 and ISSI was defined as a concentration in the top quartile for gestational age of a specific inflammation-related protein on two separate days a week apart during the first two postnatal weeks. We first assessed the risk of brain damage indicators comparing 1) neonates who had HTT to those without (regardless of ISSI), and 2) neonates with HTT only, ISSI only, or HTT+ ISSI, to those who were exposed to neither HTT nor ISSI. HTT was defined as a TSH concentration in the highest quartile for gestational age on postnatal day 14.
In univariable models that compared those with HTT to those without, HTT was not significantly associated with any indicator of brain damage. In models that compared HTT only, ISSI only, and HTT+ISSI, to those with neither, children with ISSI only or with HTT+ISSI were at significantly higher risk of ventriculomegaly [odds ratios (OR) ranged from 2–6], while those with HTT only were at significantly reduced risk of a hypoechoic lesion [ORs ranged from 0.2–0.4]. Children with HTT only had a higher risk of quadriparesis and those with ISSI alone had a higher risk of hemiparesis [ORs ranged from 1.6–2.4]. Elevated risk of a very low mental development score was associated with both ISSI only and with HTT+ISSI while a very low motor development score and microcephaly were associated with HTT+ISSI.
The association of HTT with increased or decreased risk of indicators of brain damage depends upon the presence or absence of ISSI.
PMCID: PMC4317282  PMID: 24897395
thyroid stimulating hormone; inflammation; cerebral palsy; microcephaly
2.  Immunogenicity of Haemophilus influenzae Type b Protein Conjugate Vaccines in Very Low Birth Weight Infants 
PMCID: PMC3960569  PMID: 24569312
Infant; premature; infant; very low birth weight; Haemophilus influenzae vacines; immunization; vaccines
3.  Systemic inflammation, intraventricular hemorrhage, and white matter injury 
Journal of child neurology  2012;28(12):1637-1645.
To see if the systemic inflammation profile of 123 infants born before the 28th week of gestation who had intraventricular hemorrhage (IVH) without white matter injury (WMI) differed from that of 68 peers who had both IVH and WMI, we compared both groups to 677 peers who had neither. Cranial ultrasound scans were read independently by multiple readers until concordance. The concentrations of 25 proteins were measured with multiplex arrays using an electrochemiluminescence system. Infants who had IVH and WMI were more likely than others to have elevated concentrations of CRP and IL-8 on days 1, 7, and 14, and elevated concentrations of SAA and TNF-alpha on 2 of these days. IVH should probably be viewed as two entities, IVH unaccompanied by WMI, and IVH accompanied by WMI. Each entity is associated with inflammation, but IVH accompanied by WMI has a stronger inflammatory signal than IVH unaccompanied by WMI.
PMCID: PMC4166653  PMID: 23112243
Infant; premature; hemorrhage; brain injuries; acute; inflammation
4.  An Empirical Comparison of Tree-Based Methods for Propensity Score Estimation 
Health Services Research  2013;48(5):1798-1817.
To illustrate the use of ensemble tree-based methods (random forest classification [RFC] and bagging) for propensity score estimation and to compare these methods with logistic regression, in the context of evaluating the effect of physical and occupational therapy on preschool motor ability among very low birth weight (VLBW) children.
Data Source
We used secondary data from the Early Childhood Longitudinal Study Birth Cohort (ECLS-B) between 2001 and 2006.
Study Design
We estimated the predicted probability of treatment using tree-based methods and logistic regression (LR). We then modeled the exposure-outcome relation using weighted LR models while considering covariate balance and precision for each propensity score estimation method.
Principal Findings
Among approximately 500 VLBW children, therapy receipt was associated with moderately improved preschool motor ability. Overall, ensemble methods produced the best covariate balance (Mean Squared Difference: 0.03–0.07) and the most precise effect estimates compared to LR (Mean Squared Difference: 0.11). The overall magnitude of the effect estimates was similar between RFC and LR estimation methods.
Propensity score estimation using RFC and bagging produced better covariate balance with increased precision compared to LR. Ensemble methods are a useful alterative to logistic regression to control confounding in observational studies.
PMCID: PMC3796115  PMID: 23701015
Propensity scores; tree-based methods; ensemble methods
5.  Interneuronal Mechanism for Tinbergen’s Hierarchical Model of Behavioral Choice 
Current Biology  2014;24(17):2018-2024.
Recent studies of behavioral choice support the notion that the decision to carry out one behavior rather than another depends on the reconfiguration of shared interneuronal networks [1]. We investigated another decision-making strategy, derived from the classical ethological literature [2, 3], which proposes that behavioral choice depends on competition between autonomous networks. According to this model, behavioral choice depends on inhibitory interactions between incompatible hierarchically organized behaviors. We provide evidence for this by investigating the interneuronal mechanisms mediating behavioral choice between two autonomous circuits that underlie whole-body withdrawal [4, 5] and feeding [6] in the pond snail Lymnaea. Whole-body withdrawal is a defensive reflex that is initiated by tactile contact with predators. As predicted by the hierarchical model, tactile stimuli that evoke whole-body withdrawal responses also inhibit ongoing feeding in the presence of feeding stimuli. By recording neurons from the feeding and withdrawal networks, we found no direct synaptic connections between the interneuronal and motoneuronal elements that generate the two behaviors. Instead, we discovered that behavioral choice depends on the interaction between two unique types of interneurons with asymmetrical synaptic connectivity that allows withdrawal to override feeding. One type of interneuron, the Pleuro-Buccal (PlB), is an extrinsic modulatory neuron of the feeding network that completely inhibits feeding when excited by touch-induced monosynaptic input from the second type of interneuron, Pedal-Dorsal12 (PeD12). PeD12 plays a critical role in behavioral choice by providing a synaptic pathway joining the two behavioral networks that underlies the competitive dominance of whole-body withdrawal over feeding.
Graphical Abstract
•Behavioral choice between mutually exclusive behaviors is hierarchically organized•Touch-induced whole-body withdrawal inhibits sucrose-driven feeding rhythms•Two interneurons with asymmetrical connectivity allow withdrawal to override feeding•Suppression of feeding is due to the enhancement of tonic inhibition
A current model of behavioral choice depends on the reconfiguration of shared interneuronal networks. Pirger et al. provide evidence for the alternative Tinbergen model, which depends on a hierarchically based competition between autonomous networks. An asymmetrical inhibitory interneuronal pathway allows one behavior to dominate the other.
PMCID: PMC4159561  PMID: 25155505
6.  Apolipoprotein E (APOE) Genotype and Outcome in Infants with Hypoxic-Ischemic Encephalopathy (HIE) 
Pediatric research  2013;75(3):424-430.
Adults with the apolipoprotein E gene (APOE) alleles e4 and e2 are at high risk of poor neurologic outcome after brain injury. The e4 allele has been associated with cerebral palsy and the e2 allele has been associated with worse neurologic outcome with congenital heart disease. This study was done to test the hypothesis that APOE genotype is associated with outcome among neonates who survive after hypoxic-ischemic encephalopathy (HIE).
We conducted a cohort study of infants who survived HIE and had 18 – 22 month standardized neurodevelopmental evaluations to assess associations between disability and APOE genotypes e3/e3, e4/-, and e2/-
139 survivors were genotyped. 86 (62%) were e3/e3, 41 (29%) were e4/-, and 14 (10%) were e2/-. 129 infants had genotype and follow-up data; 26% had moderate or severe disabilities. Disability prevalence was 30% and 19% among those with and without e3/e3 genotype, 25% and 26% among those with and without the e2 allele, and 18% and 29% among those with and without the e4 allele. None of the differences were statistically significant. Cerebral palsy prevalence was also similar among genotype groups.
Disability was not associated with APOE genotype in this cohort of HIE survivors.
PMCID: PMC4095992  PMID: 24322171
7.  Neurodevelopmental Outcomes in the Early CPAP and Pulse Oximetry Trial 
The New England journal of medicine  2012;367(26):2495-2504.
Previous results from our trial of early treatment with continuous positive airway pressure (CPAP) versus early surfactant treatment in infants showed no significant difference in the outcome of death or bronchopulmonary dysplasia. A lower (vs. higher) target range of oxygen saturation was associated with a lower rate of severe retinopathy but higher mortality. We now report longer-term results from our prespecified hypotheses.
Using a 2-by-2 factorial design, we randomly assigned infants born between 24 weeks 0 days and 27 weeks 6 days of gestation to early CPAP with a limited ventilation strategy or early surfactant administration and to lower or higher target ranges of oxygen saturation (85 to 89% or 91 to 95%). The primary composite outcome for the longer-term analysis was death before assessment at 18 to 22 months or neurodevelopmental impairment at 18 to 22 months of corrected age.
The primary outcome was determined for 1234 of 1316 enrolled infants (93.8%); 990 of the 1058 surviving infants (93.6%) were evaluated at 18 to 22 months of corrected age. Death or neurodevelopmental impairment occurred in 27.9% of the infants in the CPAP group (173 of 621 infants), versus 29.9% of those in the surfactant group (183 of 613) (relative risk, 0.93; 95% confidence interval [CI], 0.78 to 1.10; P = 0.38), and in 30.2% of the infants in the lower-oxygen-saturation group (185 of 612), versus 27.5% of those in the higher-oxygen-saturation group (171 of 622) (relative risk, 1.12; 95% CI, 0.94 to 1.32; P = 0.21). Mortality was increased with the lower-oxygen-saturation target (22.1%, vs. 18.2% with the higher-oxygen-saturation target; relative risk, 1.25; 95% CI, 1.00 to 1.55; P = 0.046).
We found no significant differences in the composite outcome of death or neurodevelopmental impairment among extremely premature infants randomly assigned to early CPAP or early surfactant administration and to a lower or higher target range of oxygen saturation. (Funded by the Eunice Kennedy Shriver National Institute of Child Health and Human Development and the National Heart, Lung, and Blood Institute; SUPPORT number, NCT00233324.)
PMCID: PMC4140695  PMID: 23268664
8.  Antenatal Steroid Exposure and Pulmonary Outcomes in Adolescents Born With Very Low Birth Weight 
To compare asthma history and pulmonary function in adolescents born prematurely with very low birth weight with and without antenatal steroid exposure.
Study Design
We studied 188 fourteen-year-olds (94 exposed, 84 male). We used parent report to ascertain asthma and asthma-related symptoms and spirometry to assess pulmonary function. Steroid-exposed and unexposed groups were compared using Mann-Whitney U tests (continuous variables), chi-square analysis (categorical variables), and logistic regression (multivariate analyses).
The steroid-exposed group had greater prevalence of larger airway obstruction (35%v. 21%), and steroid-exposed adolescents with birth weights < 1000 grams had 4.5-fold higher odds of larger airway obstruction. Wheezing in the last 12 months was twice as prevalent in steroid-exposed adolescents with birth weights between 1000–1500 g.
Antenatal steroid exposure does not provide long-term benefits for pulmonary outcomes in adolescents born prematurely with very low birth weight in the era of surfactant therapy.
PMCID: PMC4077331  PMID: 23788368
Corticosteroids; Prematurity; Lung Function; Asthma
9.  Pharmacokinetics and Safety of a Single Intravenous Dose of myo-Inositol in Preterm Infants of 23 to 29 weeks 
Pediatric research  2013;74(6):721-729.
Myo-inositol given to preterm infants with respiratory distress has reduced death, increased survival without bronchopulmonary dysplasia (BPD) and reduced severe retinopathy of prematurity (ROP) in 2 randomized trials. Pharmacokinetic (PK) studies in extremely preterm infants are needed prior to efficacy trials.
Infants of 23–29 weeks gestation were randomized to a single intravenous (IV) dose of inositol at 60 or 120 mg/kg or placebo. Over 96 h, serum levels (sparse sampling population PK) and urine inositol excretion were determined. Population PK models were fit using a nonlinear mixed effects approach. Safety outcomes were recorded.
A 1-compartment model that included factors for endogenous inositol production, allometric size based on weight, gestational age (GA) strata and creatinine clearance fit the data best. The central volume of distribution was 0.5115 l/kg, the clearance 0.0679 l/kg/h, endogenous production 2.67 mg/kg/h and the half life 5.22 h when modeled without the covariates. During the first 12 h renal inositol excretion quadrupled in the 120 mg/kg group, returning to near baseline after 48 h. There was no diuretic side-effect. No significant differences in adverse events occurred between the 3 groups (p > 0.05).
A single compartment model accounting for endogenous production satisfactorily described the PK of IV inositol.
PMCID: PMC3962781  PMID: 24067395
10.  Septicemia mortality reduction in neonates in a heart rate characteristics monitoring trial 
Pediatric research  2013;74(5):570-575.
Abnormal heart rate characteristics (HRC) wax and wane in early stages of culture-positive, late-onset septicemia (LOS) in patients in the neonatal intensive care unit (NICU). Continuously monitoring an HRC index leads to a reduction in mortality among very low birth weight (VLBW) infants. We hypothesized that the reduction in mortality was due to a decrease in septicemia-associated mortality.
This is a secondary analysis of clinical and HRC data from 2989 VLBW infants enrolled in a randomized controlled trial of HRC monitoring in 9 NICUs from 2004–2010.
LOS was diagnosed 974 times in 700 patients, and the incidence and distribution of organisms were similar in HRC display and non-display groups. Mortality within 30 days of LOS was lower in the HRC display compared to the non-display group (11.8% vs 19.6%, RR 0.61, 95% CI 0.43, 0.87, p<0.01), but mortality reduction was not statistically significant for patients without LOS. There were fewer large, abrupt increases in the HRC index in the days leading up to LOS diagnosis in infants whose HRC index was displayed.
Continuous HRC monitoring is associated with a lower septicemia-associated mortality in VLBW infants, possibly due to diagnosis earlier in the course of illness.
PMCID: PMC4026205  PMID: 23942558
11.  Adiposity in Adolescent Offspring Born Prematurely to Mothers with Preeclampsia 
The Journal of pediatrics  2012;162(5):912-7.e1.
To evaluate the relationship between maternal preeclampsia resulting in premature delivery and adiposity in the offspring during adolescence.
Study design
The 172 study participants were 14 years old and had very low birth weight. We compared height, weight, body mass index (BMI), percent fat, waist circumference, and triceps and subscapular skin fold thicknesses between those born prematurely secondary to preeclampsia (n = 51; 22 male) and those born prematurely after nor-motensive pregnancies (n = 121; 55 male). Multiple linear regression analysis was used to adjust for potential con-founders (maternal BMI, antenatal steroid exposure, and race) and to evaluate potential explanatory variables (fetal, infancy, and childhood weight gain, and caloric intake, level of fitness, and physical activity at 14 years).
When adjusted for potential prenatal confounders (antenatal steroid exposure and race), adolescent male offspring of preeclamptic pregnancies had higher BMI (4.0 kg/m2 [1.5, 6.6]) (mean difference [95% CI]), waist circumference (11.8 cm [3.8, 19.7]), triceps (4.6 mm [0.6, 8.6]) and subscapular skinfold thicknesses (6.2 mm [1.5, 10.9]), and percent body fat (4.1% [−0.1, 8.3]). Adjusting for infancy and childhood weight gain attenuated these group differences. There were no group differences among females.
Male adolescent offspring born prematurely of women with preeclampsia have higher measures of adiposity than those born prematurely of normotensive pregnancies. (J Pediatr 2012; ■:■-■).
PMCID: PMC3785107  PMID: 23211927
12.  Inflammation-initiating illnesses, inflammation-related proteins, and cognitive impairment in extremely preterm infants 
Brain, behavior, and immunity  2013;29:104-112.
Neonatal inflammation is associated with perinatal brain damage. We evaluated to what extent elevated blood levels of inflammation-related proteins supplement information about the risk of impaired early cognitive function provided by inflammation-related illnesses. From 800 infants born before the 28th week of gestation, we collected blood spots on days 1, 7 and 14, for analysis of 25 inflammation-related proteins, and data about culture-positive bacteremia, necrotizing enterocolitis (Bell stage IIIb), and isolated perforation of the intestine, during the first two weeks, and whether they were ventilated on postnatal day 14. We considered a protein to be persistently or recurrently elevated if its concentration was in the top quartile (for gestational age and day blood was collected) on two separate days one week apart. We assessed the children at 2 years of age with the Bayley Mental Development Index (MDI). The combinations of NEC and ventilation on day 14, and of bacteremia and ventilation on day 14 consistently provided information about elevated risk of MDI <55, regardless of whether or not a variable for an elevated protein concentration was included in the model. A variable for a persistently or recurrently elevated concentration of each of the following proteins provided additional information about an increased risk of MDI <55: CRP, SAA, IL-6, TNF-alpha, IL-8, MIP-1beta, ICAM-1, E-SEL, and IGFBP-1. We conclude that elevated blood concentrations of inflammation-related proteins provide information about the risk of impaired cognitive function at age 2 years that supplements information provided by inflammation-associated illnesses.
PMCID: PMC3582030  PMID: 23295265
cognitive impairment; necrotizing enterocolitis; extreme prematurity; systemic inflammatory response; neonatal chronic lung disease; neonatal sepsis
13.  Systemic inflammation associated with mechanical ventilation among extremely preterm infants 
Cytokine  2012;61(1):315-322.
Little evidence is available to document that mechanical ventilation is an antecedent of systemic inflammation in preterm humans. We obtained blood on postnatal day 14 from 726 infants born before the 28th week of gestation and measured the concentrations of 25 inflammation-related proteins. We created multivariable models to assess the relationship between duration of ventilation and protein concentrations in the top quartile. Compared to newborns ventilated for fewer than 7 days (N=247), those ventilated for 14 days (N=330) were more likely to have elevated blood concentrations of pro-inflammatory cytokines (IL-1β, TNF-α), chemokines (IL-8, MCP-1), an adhesion molecule (ICAM-1), and a matrix metalloprotease (MMP-9), and less likely to have elevated blood concentrations of two chemokines (RANTES, MIP-1β), a matrix metalloproteinase (MMP-1), and a growth factor (VEGF). Newborns ventilated for 7-13 days (N=149) had systemic inflammation that approximated the pattern of newborns ventilated for 14 days. These relationships were not confounded by chorioamnionitis or antenatal corticosteroid exposure, and were not altered appreciably among infants with and without bacteremia. These findings suggest that two weeks of ventilation are more likely than shorter durations of ventilation to be accompanied by high blood concentrations of pro-inflammatory proteins indicative of systemic inflammation, and by low concentrations of proteins that might protect from inflammation-mediated organ injury.
PMCID: PMC3518391  PMID: 23148992
inflammation; ventilation; preterm infant; cytokine; chemokine
14.  Brain damage in preterm newborns and maternal medication: The ELGAN Study 
To evaluate the association between maternal medication use during pregnancy and cerebral white matter damage and cerebral palsy (CP) among very preterm infants.
Study Design
This analysis of data from the ELGAN Study included 877 infants born <28 weeks gestation. Mothers were interviewed, charts reviewed, placentas were cultured and assessed histologically, and children evaluated at 24 months corrected age. A diagnostic algorithm classified neurologic findings as quadriparetic CP, diparetic CP, hemiparetic CP, or no CP.
After adjustment for the potential confounding of disorders for which medications might have been indicated, the risk of quadraparetic CP remained elevated among the infants of mothers who consumed aspirin (OR=3.0, 95% CI 1.3,6.9) and non-steroidal anti-inflammatory medications (NSAIDs) (OR=2.4, 95% CI 1.04,5.8). The risk of diparetic CP was also associated with maternal consumption of an NSAID, but only if the consumption was not approved by a physician (OR=3.5, 95% CI 1.1,11.0)
The possibility that aspirin and NSAID use in pregnancy could lead to perinatal brain damage cannot be excluded.
PMCID: PMC3432943  PMID: 22939723
Cerebral palsy; cerebral white matter damage; preterm
15.  Two-hit model of brain damage in the very preterm newborn: small for gestational age and postnatal systemic inflammation 
Pediatric research  2012;73(3):362-370.
We sought to disentangle the contributions of perinatal systemic inflammation and small for gestational age (SGA) to the occurrence of low Bayley Mental Development Indices (MDIs) at age 2 years.
We measured the concentration of 25 inflammation-related proteins in blood obtained during the first 2 postnatal weeks from 805 infants who were born before the 28th week of gestation and who had MDI measurements at age 2 years and were able to walk independently.
SGA newborns who did not have systemic inflammation (a concentration of an inflammation-related protein in the top quartile for gestational age on 2 days a week apart) were at greater risk of an MDI < 55, but not 55–69, than their peers who had neither SGA nor systemic inflammation. SGA infants who had elevated blood concentrations of IL-1beta, TNF-alpha, or IL-8 during the first two postnatal weeks were at even higher risk of an MDI < 55 than their SGA peers without systemic inflammation and of their non-SGA peers with systemic inflammation.
SGA appears to place very preterm newborns at increased risk of a very low MDI. Systemic inflammation adds considerably to the increased risk.
PMCID: PMC3642985  PMID: 23364171
16.  Birth weight- and fetal weight-growth restriction: impact on neurodevelopment 
Early human development  2012;88(9):765-771.
The newborn classified as growth-restricted on birth weight curves, but not on fetal weight curves, is classified prenatally as small for gestational age (SGA), but postnatally as appropriate for gestational age (AGA).
To see (1) to what extent the neurodevelopmental outcomes at 24 months corrected age differed among three groups of infants (those identified as SGA based on birth weight curves (B-SGA), those identified as SGA based on fetal weight curves only (F-SGA), and the referent group of infants considered AGA, (2) if girls and boys were equally affected by growth restriction, and (3) to what extent neurosensory limitations influenced what we found.
Study design
Observational cohort of births before the 28 week of gestation. Outcome measures: Mental Development Index (MDI) and Psychomotor Development Index (PDI) of the Bayley Scales of Infant Development II.
B-SGA, but not F-SGA girls were at an increased risk of a PDI < 70 (OR=2.8; 95% CI: 1.5, 5.3) compared to AGA girls. B-SGA and F-SGA boys were not at greater risk of low developmental indices than AGA boys. Neurosensory limitations diminished associations among girls of B-SGA with low MDI, and among boys B-SGA and F-SGA with PDI < 70.
Only girls with the most severe growth restriction were at increased risk of neurodevelopmental impairment at 24 months corrected age in the total sample. Neurosensory limitations appear to interfere with assessing growth restriction effects in both girls and boys born preterm.
PMCID: PMC3694609  PMID: 22732241
17.  Emperic Antifungal Therapy and Outcomes in Extremely-Low-Birth-Weight Infants with Invasive Candidiasis 
The Journal of Pediatrics  2012;161(2):264-269.e2.
To assess the impact of emperic antifungal therapy of invasive candidiasis on subsequent outcomes in premature infants.
Study design
This was a cohort study of infants ≤1000 g birth weight cared for at Neonatal Research Network sites. All infants had at least 1 positive culture for Candida. Emperic antifungal therapy was defined as receipt of a systemic antifungal on the day of or the day before the first positive culture for Candida was drawn. We created Cox proportional hazards and logistic regression models stratified on propensity score quartiles to determine the effect of emperic antifungal therapy on survival, time to clearance of infection, retinopathy of prematurity, bronchopulmonary dysplasia, end-organ damage, and neurodevelopmental impairment (NDI).
136 infants developed invasive candidiasis. The incidence of death or NDI was lower for infants who received emperic antifungal therapy (19/38, 50%) compared with those who had not (55/86, 64%; odds ratio=0.27 [95% confidence interval 0.08–0.86]). There was no significant difference between the groups for any single outcome or other combined outcomes.
Emperic antifungal therapy was associated with increased survival without NDI. A prospective randomized trial of this strategy is warranted.
PMCID: PMC3380169  PMID: 22424952
Candida; neonate; mortality; neurodevelopmental impairment
18.  Intraventricular Hemorrhage and Developmental Outcomes at 24 months of age in Extremely Preterm Infants 
Journal of child neurology  2012;27(1):22-29.
Whether intraventricular hemorrhage increases the risk of adverse developmental outcome among premature infants is controversial. Using brain ultrasound, we identified IVH and white matter abnormalities among 1064 infants born before 28 weeks gestation. We identified adverse developmental outcomes at 24 months of age using a standardized neurological examination and the Bayley Scales of Infant Development Mental and Motor Scales. In logistic regression models that adjusted for gestational age, sex, and public insurance, isolated intraventricular hemorrhage was associated with visual fixation difficulty (odds ratio: 2.5 (95% confidence limits: 1.2, 5.1)) but no other adverse outcome. Infants who had a white matter lesion unaccompanied by intraventricular hemorrhage were at increased risk of cerebral palsy, low Mental and Motor Scores, and visual and hearing impairments. Except when accompanied or followed by a white matter lesion, intraventricular hemorrhage is associated with no more than a mild increase (and possibly no increase) in the risk of adverse developmental outcome during infancy.
PMCID: PMC3724508  PMID: 22232137
cerebral palsy; vision impairment; developmental delay; developmental disability; prematurity; Bayley Scales of Infant Development; neurodevelopmental outcome
19.  Cytokines and Perinatal Brain Damage 
Clinics in perinatology  2008;35(4):643-v.
PMCID: PMC3657129  PMID: 19026332
cyokines; developmental disability; cerebral palsy; mental retardation; periventricular leukomalacia; chorioamnionitis
20.  Agency Collaboration in the Care of Children with Complex Chronic Conditions 
Academic Pediatrics  2012;12(3):189-197.
To describe the network of collaboration among agencies that serve children with complex chronic conditions (CCC) and identify gaps in the network.
We surveyed representatives from agencies that serve children with CCC in Forsyth County, North Carolina about their agencies’ existing and desired collaborations with other agencies in the network. We used Social Network Analytical methods to describe gaps in the network. Mean out- and in-degree centrality (number of collaborative ties extending from or directed towards an agency) and density (ratio of extant ties to all possible ties) were measured.
In this network with 3,658 possible collaborative ties, care-coordination agencies and pediatric practices reported the highest existing collaborations with other agencies (out-degree centrality: 32 and 30 respectively). Pediatric practices reported strong ties with subspecialty clinics (density: 73%), but weak ties with family support services (density: 3%). Pediatric practices and subspecialty clinics (in-degree: 26) received the highest collaborative ties from other agencies. Support services and durable medical equipment companies reported low ties with other agencies (out-degree: 7 and 10 respectively). Nursing agencies reported the highest desired collaborations (out-degree: 18). Support services, pediatric practices and care-coordination programs had the highest in-degree centrality (7, 6 and 6 respectively) for desired collaborations. Nursing agencies and support services had the greatest gaps in collaboration.
Although collaboration exists among agencies serving children with CCC, there are many gaps in the network. Future studies should explore barriers and facilitators to inter-agency collaborations and whether increased collaboration in the network improves patient-level outcomes.
PMCID: PMC3354334  PMID: 22583632
children; special needs; collaboration; health services research
21.  Systemic responses of preterm newborns with presumed or documented bacteremia 
To compare the frequency of elevated concentrations of inflammation-related proteins in the blood of infants born before the 28th week of gestation who had documented bacteremia to those who had presumed (antibiotic-treated but culture-negative) bacteremia to those who neither.
The subjects of this study are the 868 infants born at 14 institutions for whom information about protein measurements on at least two of the three protocol days (days 1, 7, and 14) was available and who did not have Bell stage 3 necrotizing enterocolitis or isolated bowel perforation, which were strongly associated with bacteremia in this sample.
Newborns with presumed early (week 1) bacteremia had elevated concentrations of only a few inflammation-related proteins, while those who had presumed late (weeks 2–4) bacteremia did not have any elevations. In contrast, newborns who had documented early bacteremia had a moderately strong signal, while those who had documented late bacteremia had a stronger signal with more protein concentrations elevated on two separate occasions a week apart.
Culture-confirmed early and late bacteremia are accompanied/followed by systemic inflammatory responses not seen with presumed early and late bacteremia.
PMCID: PMC3294175  PMID: 22085230
bacteremia; infant; premature; blood proteins
22.  Elevated concentrations of inflammation-related proteins in postnatal blood predict severe developmental delay at two years in extremely premature infants 
The Journal of Pediatrics  2011;160(3):395-401.e4.
To evaluate the hypothesis that elevated levels of inflammation-related proteins in early postnatal blood predict impaired mental and motor development among extremely preterm infants.
Study design
We measured concentrations of 25 inflammation-related proteins in blood collected on postnatal days 1, 7, and 14 from 939 infants born before 28 weeks gestation. An elevated level was defined as a concentration in the highest quartile for gestational age and day of blood collection. We identified impaired development at 24 months of age using the Bayley Scales of Infant Development. The primary outcomes were scores on the Mental or Motor Scale below 55 (more than 3 standard deviations below the mean).
For 17 of the 25 inflammation-related proteins, one or more statistically significant association (p < 0.01) was found between an elevated blood level of the protein and a developmental impairment. Elevations on multiple days were more often associated with developmental impairment than elevations present for only one day. The highest number of elevations was found in day-14 blood.
In extremely preterm infants, elevated levels of inflammation-related proteins in blood collected on postnatal days 7 and 14, especially when sustained, are associated with impaired mental and motor development at age two years.
PMCID: PMC3279610  PMID: 22000304
cytokines; developmental disability; prematurity; Bayley Scales of Infant Development; neurodevelopmental outcome
23.  Does Aggressive Phototherapy Increase Mortality while Decreasing Profound Impairment among the Smallest and Sickest Newborns? 
Aggressive phototherapy (AgPT) is widely used and assumed to be safe and effective for even the most immature infants. We assessed whether the benefits and hazards for the smallest and sickest infants differed from those for other extremely low birth weight (ELBW; (≤1000 g) infants in our Neonatal Research Network trial, the only large trial of AgPT.
Study Design
ELBW infants (n=1974) were randomized to AgPT or conservative phototherapy at age 12–36 hours. The effect of AgPT on outcomes (death; impairment; profound impairment; death or impairment [primary outcome], and death or profound impairment) at 18–22 months corrected age was related to BW stratum (501–750 g; 751–1000 g) and baseline severity of illness using multilevel regression equations. The probability of benefit and of harm was directly assessed with Bayesian analyses.
Baseline illness severity was well characterized using mechanical ventilation and FiO2 at 24 hours age. Among mechanically ventilated infants ≤750 g BW (n =684), a reduction in impairment and in profound impairment was offset by higher mortality (p for interaction <0.05) with no significant effect on composite outcomes. Conservative Bayesian analyses of this subgroup identified a 99% (posterior) probability that AgPT increased mortality, a 97% probability that AgPT reduced impairment, and a 99% probability that AgPT reduced profound impairment.
Findings from the only large trial of AgPT suggest that AgPT may increase mortality while reducing impairment and profound impairment among the smallest and sickest infants. New approaches to reduce their serum bilirubin need development and rigorous testing.
PMCID: PMC3558278  PMID: 22652561
Phototherapy; bilirubin; severity of illness; ELBW infant; impairment; randomized clinical trial; statistical interaction; Bayesian analysis
24.  Axonal trafficking of an antisense RNA transcribed from a pseudogene is regulated by classical conditioning 
Scientific Reports  2013;3:1027.
Natural antisense transcripts (NATs) are endogenous RNA molecules that are complementary to known RNA transcripts. The functional significance of NATs is poorly understood, but their prevalence in the CNS suggests a role in brain function. Here we investigated a long NAT (antiNOS-2 RNA) associated with the regulation of nitric oxide (NO) production in the CNS of Lymnaea, an established model for molecular analysis of learning and memory. We show the antiNOS-2 RNA is axonally trafficked and demonstrate that this is regulated by classical conditioning. Critically, a single conditioning trial changes the amount of antiNOS-2 RNA transported along the axon. This occurs within the critical time window when neurotransmitter NO is required for memory formation. Our data suggest a role for the antiNOS-2 RNA in establishing memories through the regulation of NO signaling at the synapse.
PMCID: PMC3537157  PMID: 23293742
25.  Extreme prematurity and attention deficit: epidemiology and prevention 
PMCID: PMC3776954  PMID: 24065904
extreme prematurity; neurodevelopmental impairment; attention; attention deficit hyperactivity disorder; neuroprotection

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