184 research outputs found
Neural correlates of executive attention in adults born very preterm
Very preterm birth is associated with an increased prevalence of attention problems and may especially impair executive attention, i.e., top-down control of attentional selection in situations where distracting information interferes with the processing of task-relevant stimuli. While there are initial findings linking structural brain alterations in preterm-born individuals with attention problems, the functional basis of these problems are not well understood. The present study used an fMRI adaptation of the Attentional Network Test to examine the neural correlates of executive attention in a large sample of N = 86 adults born very preterm and/or with very low birth weight (VP/VLBW), and N = 100 term-born controls. Executive attention was measured by comparing task behavior and brain activations associated with the processing of incongruent vs. congruent arrow flanker stimuli. Consistent with subtle impairments of executive attention, the VP/VLBW group showed lower accuracy and a tendency for increased response times during the processing of incongruent stimuli. Both groups showed similar activation patters, especially within expected fronto-cingulo-parietal areas, but no significant between-group differences. Our results argue for a maintained attention-relevant network organization in high-functioning preterm born adults in spite of subtle deficits in executive attention. Gestational age and neonatal treatment variables showed associations with task behavior, and brain activation in the dorsal ACC and lateral occipital areas, suggesting that the degree of prematurity (and related neonatal complications) has subtle modulatory influences on executive attention processing
White matter alterations of the corticospinal tract in adults born very preterm and/or with very low birth weight
White matter (WM) injury, either visible on conventional magnetic resonance images (MRI) or measurable by diffusion tensor imaging (DTI), is frequent in preterm born individuals and often affects the corticospinal tract (CST). The relation between visible and invisible white mater alterations in the reconstructed CST of preterm subjects has so far been studied in infants, children and up to adolescence. Therefore, we probabilistically tracked the CST in 53 term-born and 56 very preterm and/or low birth weight (VP/VLBW, < 32 weeks of gestation and/or birth weight < 1,500 g) adults (mean age 26 years) and compared their DTI parameters (axial, radial, mean diffusivity—AD, RD, MD, fractional anisotropy—FA) in the whole CST and slice-wise along the CST. Additionally, we used the automatic, tract-based-spatial-statistics (TBSS) as an alternative to tractography. We compared control and VP/VLBW and subgroups with and without CST WM lesions visible on conventional MRI. Compared to controls, VP/VLBW subjects had significantly higher diffusivity (AD, RD, MD) in the whole CST, slice-wise along the CST, and in multiple regions along the TBSS skeleton. VP/VLBW subjects also had significantly lower (TBSS) and higher (tractography) FA in regions along the CST, but no different mean FA in the tracked CST as a whole. Diffusion changes were weaker, but remained significant for both, tractography and TBSS, when excluding subjects with visible CST lesions. Chronic CST injury persists in VP/VLBW adults even in the absence of visible WM lesions, indicating long-term structural WM changes induced by premature birth
Automated quantitative evaluation of brain MRI may be more accurate for discriminating preterm born adults
Objective
To investigate the structural brain abnormalities and their diagnostic accuracy through qualitative and quantitative analysis in term born and very preterm birth or with very low birth weight (VP/VLBW) adults.
Methods
We analyzed 3-T MRIs acquired in 2011–2013 from 67 adults (27 term born controls, mean age 26.4 years, 8 females; 40 VP/VLBWs, mean age 26.6 years, 16 females). We compared automatic segmentations of the white matter, deep gray matter and cortical gray matter, manual corpus callosum measurements and visual ratings of the ventricles and white matter with t tests, logistic regression, and receiver operator characteristic (ROC) curves.
Results
Automatic segmentation correctly classified 84% of cases; visual ratings correctly classified 63%. Quantitative volumetry based on automatic segmentation revealed higher ventricular volume, lower posterior corpus callosum, and deep gray matter volumes in VP/VLBW subjects compared to controls (p < 0.01). Visual rating and manual measurement revealed a thinner corpus callosum in VP/VLBW adults (p = 0.04) and deformed lateral ventricles (p = 0.03) and tendency towards more “dirty” white matter (p = 0.06). Automatic/manual measures combined with visual ratings correctly classified 87% of cases. Stepwise logistic regression identified three independent features that correctly classify 81% of cases: ventricular volume, deep gray matter volume, and white matter aspect.
Conclusion
Enlarged and deformed lateral ventricles, thinner corpus callosum, and “dirty” white matter are prevalent in preterm born adults. Their visual evaluation has low diagnostic accuracy. Automatic volume quantification is more accurate but time consuming. It may be useful to ask for prematurity before initiating further diagnostics in subjects with these alterations
UBTF::ATXN7L3 gene fusion defines novel B cell precursor ALL subtype with CDX2 expression and need for intensified treatment
Genomic aberrations—gene fusions in the majority of cases—and corresponding transcriptional regulations define an increasingly complex landscape of molecular subtypes in B cell precursor acute lymphoblastic leukemia (BCP-ALL) [1]. Up to 15% of patients cannot be allocated to established subtypes, suggesting the presence of unrecognized drivers—especially in adult patients who have been less studied so far
White matter macro- and microstructure alterations in preterm born adults
Introduction: White matter (WM) injury, both macroscopic (visible on conventional MRI) and microscopic (detectable by diffusion tensor imaging, DTI) is frequent among preterm born infants investigated in later life (Volpe, 2009). Degree and localization vary, but the corticospinal tract (CST) is often affected (Eikenes et al., 2011). The relation between the micro- and macroscopic CST alterations has only been studied to our knowledge up to adolescence (Bassi et al., 2011, Estep et al., 2014 and Groeschel et al., 2014) but not in adults. We aimed to assess group differences in micro- and macroscopic WM integrity of the CST between preterm and full-term born adults and to evaluate the impact of macroscopic lesions onto the DTI parameters in and along the CST.
Methods: As part of a prospective study of preterm birth (Bavarian Longitudinal Study), we investigated adults at 26 years of age by means of MRI. Artifact-free DTI data were available from 51 full-term and 55 preterm born subjects (<32 weeks gestation or birth weight < 1500 g). In these subjects we probabilistically reconstructed the CST (Giorgio et al., 2010) and extracted DTI parameters (mean, axial, radial diffusivity - MD, AD, RD, and fractional anisotropy, FA) in the CST and slice-wise along the CST. On FLAIR-MRI images we identified macroscopic WM lesions as hyperintensities, noted their relation to the CST and correlated their presence with the DTI.
Results and discussion: WM hyperintensities, periventricular or in the corona radiata, were present in 9 of 51 (18%) full-term and 26 of 55 (47%) preterm born subjects. In 3 of 51 (6%) full-term and 17 of 55 (30%) preterm born subjects these ”lesions” affected the CST. Compared to full-term individuals, the preterm born subjects had significantly higher diffusivity (MD, AD, RD) in and along the CST but no difference in FA. These changes were weaker, but nevertheless remained significant when excluding subjects with macroscopic lesions. This suggests chronic CST injury with increased tissue water content (Aung et al., 2013) even in the absence of visible WM lesions and points towards a high susceptibility of the CST after preterm birth
Strategisches Management in Kommunen: Entstehung, Inhalte und Wirkungen von Digitalisierungs- und Nachhaltigkeitsstrategien
Der Beitrag untersucht Praxen des strategischen Managements in deutschen Kommunalverwaltungen am Beispiel von Digitalisierungs- und Nachhaltigkeitsstrategien. Es werden drei Forschungsfragen bearbeitet:
1. Was sind typische Inhalte und Strukturen solcher Strategien?
2. Wie und warum entstehen solche Strategien?
3. Welche Erfahrungen machen Kommunen mit diesen Strategien?
Do inattention and hyperactivity symptoms equal scholastic impairment? evidence from three European cohorts
Background
Attention Deficit/Hyperactivity Disorder (ADHD) affects many children, adolescents, and adults and is associated with a number of impairments. Poor academic performance is related to ADHD in clinical samples. However, it is unclear to what extent core ADHD symptoms and scholastic impairment are related in non-referred school-aged children.
Methods
Data come from three population-based cohorts from Sweden, Denmark, and Finland, which are part of the Nordic Network on ADHD. The combined sample size was 13,087 children who were studied at ages 7–8 or 10–12 years. Teachers rated children on inattention and hyperactivity symptoms and reported children's scholastic performance on basic skills.
Results
There was a significant association in all cohorts between core ADHD symptoms and scholastic impairment in reading, writing, and mathematics. Particularly, inattention was related to a two to tenfold increase in scholastic impairment. Prevalence of hyperactivity symptoms was similar across the three cohorts, but inattention was lowest among children from the Finnish cohort, after stratification on living conditions.
Conclusion
These results extend previous reports of scholastic impairment among children with clinically diagnosed ADHD to non-referred population samples from three European countries. Surveillance policies should be implemented in school systems to catch children in need of behavioral or scholastic support early
Azimuthal anisotropy of charged jet production in root s(NN)=2.76 TeV Pb-Pb collisions
We present measurements of the azimuthal dependence of charged jet production in central and semi-central root s(NN) = 2.76 TeV Pb-Pb collisions with respect to the second harmonic event plane, quantified as nu(ch)(2) (jet). Jet finding is performed employing the anti-k(T) algorithm with a resolution parameter R = 0.2 using charged tracks from the ALICE tracking system. The contribution of the azimuthal anisotropy of the underlying event is taken into account event-by-event. The remaining (statistical) region-to-region fluctuations are removed on an ensemble basis by unfolding the jet spectra for different event plane orientations independently. Significant non-zero nu(ch)(2) (jet) is observed in semi-central collisions (30-50% centrality) for 20 <p(T)(ch) (jet) <90 GeV/c. The azimuthal dependence of the charged jet production is similar to the dependence observed for jets comprising both charged and neutral fragments, and compatible with measurements of the nu(2) of single charged particles at high p(T). Good agreement between the data and predictions from JEWEL, an event generator simulating parton shower evolution in the presence of a dense QCD medium, is found in semi-central collisions. (C) 2015 CERN for the benefit of the ALICE Collaboration. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).Peer reviewe
Repositioning of the global epicentre of non-optimal cholesterol
High blood cholesterol is typically considered a feature of wealthy western countries(1,2). However, dietary and behavioural determinants of blood cholesterol are changing rapidly throughout the world(3) and countries are using lipid-lowering medications at varying rates. These changes can have distinct effects on the levels of high-density lipoprotein (HDL) cholesterol and non-HDL cholesterol, which have different effects on human health(4,5). However, the trends of HDL and non-HDL cholesterol levels over time have not been previously reported in a global analysis. Here we pooled 1,127 population-based studies that measured blood lipids in 102.6 million individuals aged 18 years and older to estimate trends from 1980 to 2018 in mean total, non-HDL and HDL cholesterol levels for 200 countries. Globally, there was little change in total or non-HDL cholesterol from 1980 to 2018. This was a net effect of increases in low- and middle-income countries, especially in east and southeast Asia, and decreases in high-income western countries, especially those in northwestern Europe, and in central and eastern Europe. As a result, countries with the highest level of non-HDL cholesterol-which is a marker of cardiovascular riskchanged from those in western Europe such as Belgium, Finland, Greenland, Iceland, Norway, Sweden, Switzerland and Malta in 1980 to those in Asia and the Pacific, such as Tokelau, Malaysia, The Philippines and Thailand. In 2017, high non-HDL cholesterol was responsible for an estimated 3.9 million (95% credible interval 3.7 million-4.2 million) worldwide deaths, half of which occurred in east, southeast and south Asia. The global repositioning of lipid-related risk, with non-optimal cholesterol shifting from a distinct feature of high-income countries in northwestern Europe, north America and Australasia to one that affects countries in east and southeast Asia and Oceania should motivate the use of population-based policies and personal interventions to improve nutrition and enhance access to treatment throughout the world.Peer reviewe
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