Longitudinal Structural and Diffusion-Weighted Neuroimaging of Young Children Born Preterm.

BACKGROUND: Children born preterm are at risk for diffuse injury to subcortical gray and white matter. METHODS: We used a longitudinal cohort study to examine the development of subcortical gray matter and white matter volumes, and diffusivity measures of white matter tracts following preterm birth. Our participants were 47 children born preterm (24 to 32 weeks gestational age) and 28 children born at term. None of the children born preterm had significant neonatal brain injury. Children received structural and diffusion weighted magnetic resonance imaging scans at ages five, six, and seven years. We examined volumes of amygdala, hippocampus, caudate nucleus, putamen, thalamus, brainstem, cerebellar white matter, intracranial space, and ventricles, and volumes, fractional anisotropy, and mean diffusivity of anterior thalamic radiation, cingulum, corticospinal tract, corpus callosum, inferior frontal occipital fasciculus, inferior longitudinal fasciculus, temporal and parietal superior longitudinal fasciculus, and uncinate fasciculus. RESULTS: Children born preterm had smaller volumes of thalamus, brainstem, cerebellar white matter, cingulum, corticospinal tract, inferior frontal occipital fasciculus, uncinate fasciculus, and temporal superior longitudinal fasciculus, whereas their ventricles were larger compared with term-born controls. We found no significant effect of preterm birth on diffusivity measures. Despite developmental changes and growth, group differences were present and similarly strong at all three ages. CONCLUSION: Even in the absence of significant neonatal brain injury, preterm birth has a persistent impact on early brain development. The lack of a significant term status by age interaction suggests a delayed developmental trajectory.

Self-regulation task in young school age children born preterm: Correlation with early academic achievement.

BACKGROUND: Children born preterm are at risk for difficulties in executive function (EF), however there are limited tools to assess EF in young children and it is not fully understood how these early deficits are related to emerging academic skills. AIMS: To examine (a) early EF differences in young children born preterm, (b) how a measure of behavioral self-regulation correlates with other measures of EF in children born preterm, and (c) how this measure relates to academic outcomes in children born preterm. STUDY DESIGN: Longitudinal cohort study. SUBJECTS: Thirty-three healthy children born preterm (25-32 weeks gestation) and 14 children born full term were assessed before starting kindergarten at age 5 and again at ages 6 and 7 years. OUTCOME MEASURES: Each assessment included a measure of behavioral self-regulation, the Head Toes Knees Shoulders task (HTKS), performance-based measures of EF, parent rating scales of EF and behavior problems, a measure of motor ability, and academic measures. RESULTS: Children born preterm performed worse on all measures of self-regulation, EF, parent-report, academic outcomes, and motor ability across time. The HTKS had weak to moderate correlations with parent-report and performance-based measures of EF, moderate to strong correlations with academic performance, and was not correlated with motor ability. CONCLUSION: This study shows the predictive value of early EF measures on functional academic outcomes and their potential as targets of effective interventions in this high-risk population.

Cognitive functions mediate the effect of preterm birth on mathematics skills in young children.

Children born preterm are at risk for cognitive deficits and lower academic achievement. Notably, mathematics achievement is generally most affected. Here, we investigated the cognitive functions mediating early mathematics skills and how these are impacted by preterm birth. Healthy children born preterm (gestational age at birth < 33 weeks; n = 51) and children born full term (n = 27) were tested at ages 5, 6, and 7 years with a comprehensive battery of tests. We categorized items of the TEMA-3: Test for Early Mathematics Abilities Third Edition into number skills and arithmetic skills. Using multiple mediation models, we assessed how the effect of preterm birth on mathematics skills is mediated by spatial working memory, inhibitory control, visual-motor integration, and phonological processing. Both number and arithmetic skills showed group differences, but with different developmental trajectories. The initial performance gap observed in the preterm children decreased over time for number skills but increased for arithmetic skills. Phonological processing, visual-motor integration, and inhibitory control were poorer in children born preterm. These cognitive functions, particularly phonological processing, had a mediating effect on both types of mathematics skills. These findings help define and chart the trajectory of the specific cognitive skills directly influencing math deficit phenotypes in children born very preterm. This knowledge provides guidance for targeted evaluation and treatment implementation.

α-Irradiation setup for primary human cell cultures.

Purpose: We present an α-irradiation setup for the irradiation of primary human cell cultures under controlled conditions using 241Am α-particles.Materials and Methods: To irradiate samples with α-particles in a valid manner, a reliable dosimetry is a great challenge because of the short α-range and the complex energy spectrum. Therefore, the distance between α-source and sample must be minimal. In the present setup, this is achieved by cells growing on a 2 µm thick biaxially-oriented polyethylene terephthalate (boPET) foil which is only 2.7 mm apart from the source. A precise and reproducible exposure time is realized through a mechanical shutter. The fluence, energy spectra and the corresponding linear energy transfer are determined by the source geometry and the material traversed. They were measured and calculated, yielding a dose rate of 8.2 ± 2.4 Gy/min. To improve cell growth on boPET foils, they were treated with air plasma. This treatment increased the polarity and thus the ability of cells attaching to the surface of the foil. Several tests including cell growth, staining for a marker of DNA double-strand breaks and a colony-forming assay were performed and confirm our dosimetry.Conclusion: With our setup, it is possible to irradiate cell cultures under defined conditions with α-particles. The plasma-treated foil is suitable for primary human cell cultures as shown in cell experiments, confirming also the expected number of particle traversals.