175 research outputs found

    Prognostic utility of magnetic resonance imaging in neonatal hypoxic-ischemic encephalopathy: substudy of a randomized trial

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    Objective: To investigate the effects of hypothermia treatment on magnetic resonance imaging (MRI) patterns of brain injury in newborns with hypoxic-ischemic encephalopathy compared with normothermia, including the prognostic utility of MRI for death and/or disability at a postnatal age of 2 years

    Desikan-Killiany-Tourville Atlas Compatible Version of M-CRIB Neonatal Parcellated Whole Brain Atlas: The M-CRIB 2.0

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    Our recently published M-CRIB atlas comprises 100 neonatal brain regions including 68 compatible with the widely-used Desikan-Killiany adult cortical atlas. A successor to the Desikan-Killiany atlas is the Desikan-Killiany-Tourville atlas, in which some regions with unclear boundaries were removed, and many existing boundaries were revised to conform to clearer landmarks in sulcal fundi. Our first aim here was to modify cortical M-CRIB regions to comply with the Desikan-Killiany-Tourville protocol, in order to offer: (a) compatibility with this adult cortical atlas, (b) greater labeling accuracy due to clearer landmarks, and (c) optimisation of cortical regions for integration with surface-based infant parcellation pipelines. Secondly, we aimed to update subcortical regions in order to offer greater compatibility with subcortical segmentations produced in FreeSurfer. Data utilized were the T2-weighted MRI scans in our M-CRIB atlas, for 10 healthy neonates (post-menstrual age at MRI 40–43 weeks, four female), and corresponding parcellated images. Edits were performed on the parcellated images in volume space using ITK-SNAP. Cortical updates included deletion of frontal and temporal poles and ‘Banks STS,’ and modification of boundaries of many other regions. Changes to subcortical regions included the addition of ‘ventral diencephalon,’ and deletion of ‘subcortical matter’ labels. A detailed updated parcellation protocol was produced. The resulting whole-brain M-CRIB 2.0 atlas comprises 94 regions altogether. This atlas provides comparability with adult Desikan-Killiany-Tourville-labeled cortical data and FreeSurfer-labeed subcortical data, and is more readily adaptable for incorporation into surface-based neonatal parcellation pipelines. As such, it offers the ability to help facilitate a broad range of investigations into brain structure and function both at the neonatal time point and developmentally across the lifespan

    Comparative evaluation of the health utilities index mark 3 and the short form 6D : evidence from an individual participant data meta-analysis of very preterm and very low birthweight adults

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    Background The most appropriate preference-based health-related quality of life (HRQoL) instruments for trials or research studies that ascertain the consequences of individuals born very preterm and/or low birthweight (VP/VLBW) are not known. Agreement between the HUI3 and SF-6D multi-attribute utility measures have not been previously investigated for VP/VLBW and normal birthweight or term-born controls. This study examined the agreement between the outputs of the HUI3 and SF-6D measures among adults born VP/VLBW and normal birthweight or term born controls. Methods We used two prospective cohorts of individuals born VP/VLBW and controls contributing to the ‘Research on European Children and Adults Born Preterm’ (RECAP) consortium which assessed HRQoL using two preference-based measures. The combined dataset of individual participant data (IPD) included 407 adult VP/VLBW survivors and 367 controls, ranging in age from 18 to 26 years. Bland–Altman plots, intra-class correlation coefficients, and generalized linear mixed models in a one-step approach were used to examine agreement between the measures. Results There was significant discordance between the HUI3 and SF-6D multi-attribute utility measures in the VP/VLBW sample, controls, and in the combined samples. Agreement between the HUI3 and SF-6D multi-attribute utility measures was weaker in controls compared with VP/VLBW individuals. Conclusions and relevance The HUI3 and SF-6D each provide unique information on different aspects of health status across the groups. The HUI3 better captures preterm-related changes to HRQoL in adulthood compared to SF-6D. Studies focused on measuring physical or cognitive aspects of health will likely benefit from using the HUI3 instead of the SF-6D, regardless of gestational age at birth and birthweight status

    Impact of hypercapnia on alveolar Na+-transport : Establishing a system for ENaC-protein detection

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    Acute respiratory distress syndrome is a life threatening condition triggered by a variety of pulmonary and extrapulmonary causes, that is characterized by pulmonary edema and subsequently impaired gas exchange. Due to lung protective ventilation strategies, its treatment is often associated with systemic accumulation of CO2, a condition termed permissive hypercapnia. Recent studies report a negative effect of CO2 on alveolar fluid clearance, a process mediated by its two key elements the Na+,K+-ATPase and epithelial Na+-channels (ENaCs). A reduced activity of the Na+,K+-ATPase during hypercapnia has already been demonstrated, but regulation of ENaC has never been directly linked to CO2. Many molecular signaling events that are activated during hypercapnia are known to regulate ENaC function, so the present study aimed to generate and subsequently apply techniques to investigate a possible contribution of ENaC to the reduction of alveolar epithelial fluid transport upon hypercapnia. ENaC function was studied in H441 cells by Ussing chamber experiments which revealed no significant regulation during short term hypercapnia, but a clear reduction of ENaC function during sustained hypercapnia. To identify the signaling mechanism on the molecular level, epitope-tagged human ENaC constructs for the α-, β- and γ-subunit were cloned and initially expressed in A549 cells. Exposition to hypercapnia up to 4 hours did not significantly reduce cell surface expression of the ENaC-subunits, but after 24 hours, a significant decrease of β-ENaC was observed. Since the molecular sizes of α- and γ-ENaC expressed in A549 cells were differing from previously published studies, transfection of ENaC was continued in other cells. H441 cells are commonly used for ENaC studies, so their transfection was established, yielding an efficiency of about 60 %. The molecular sizes of transfected ENaC subunits matched the pattern that was expected, but expression levels were evanescent and too low for further experiments. Since ENaC detection in these two cell lines remained problematic, a novel methodology was applied. Since the primary site of ENaC expression in the lung are epithelial cells, rat primary alveolar epithelial cells type II were used as recipients for ENaC plasmids. Non-viral transfection of ATII cells has been inefficient in the past, but during the present study a protocol was generated to efficiently deliver nucleic acids to exactly this cell type. ENaC expression was largely increased in ATII cells, compared to the cell lines used, indicating that established system might be extremely useful for further studies involving ENaC turnover. Thus, a new and highly relevant, non-viral transfection technique for primary alveolar epithelial type II cells was established, providing ground-breaking opportunities for future pulmonary research.Das Atemnotsyndrom des Erwachsenen ist eine lebensbedrohliche Erkrankung, ausgelöst durch eine Reihe von Faktoren, die direkt oder indirekt auf die Lunge einwirken . Charakteristisch für dieses Syndrom sind pulmonare Ödeme und daraus resultierend ein eingeschränkter Gasaustausch. Die daher benötigte künstliche Beatmung führt im Zuge von protektiven Beatmungsstrategien oft zu einer systemischen Anreicherung von CO2 (Hyperkapnie). Einige Studien zeigen, dass erhöhte CO2-Level den Flüssigkeitstransport der Lunge einschränken. Dieser aktive Prozess wird maßgeblich durch zwei Komponenten, die Na+,K+-ATPase und epitheliale Na+-Kanäle (ENaCs), kontrolliert. Eine Beeinträchtigung der Na+,K+-ATPase durch CO2 gezeigt, für ENaCs ist dies bislang nicht bekannt. Einige bekannte Regulatoren von ENaCs werden jedoch während Hyperkapnie aktiviert. Das Ziel der vorliegenden Arbeit war, Methoden zu etablieren und anzuwenden, die einen möglichen Einfluss von CO2 auf ENaC zeigen. Funktionelle Versuche wurden an H441-Zellen mit Ussing-Kammer-Messungen durchgeführt. Während akuter Hyperkapnie konnte keine signifikante Regulation von ENaC nachgewiesen werden, jedoch war die ENaC-Funktion bei anhaltender Hyperkapnie deutlich verringert. Um die Signalwege auf molekularer Ebene zu untersuchen, wurde die α-, β- und γ- Untereinheit des humanen ENaC kloniert, genetisch modifiziert und in A549 Zellen überexprimiert. Nach bis zu vierstündiger Hyperkapnie erfolgte keine Regulation von ENaC, jedoch wurde nach 24 Stunden eine deutlich verminderte Menge β-ENaC in der Zellmembran nachgewiesen. Da die Größen von α- und γ-ENaC von den bisher publizierten abwichen, wurden weitere Versuche in H441 Zellen durchgeführt. Die Transfektion dieser Zelllinie wurde etabliert und erreichte eine Effizienz von ungefähr 60 %. Die posttranslationale Regulation der α- und γ-Untereinheiten, insbesondere die proteolytische Aktivierung funktionierten wie in der Literatur beschrieben, jedoch waren die Expressionslevel zu gering für weitere Versuche. In der Lunge werden ENaCs überwiegend in epithelialen Zellen exprimiert. Diese Zellen konnten bisher jedoch nicht effizient transfiziert werden, ohne Viren einzusetzen. In der vorliegenden Arbeit wurde jedoch eine effiziente Methode zur Transfektion von primären epithelialen Zellen der Ratte erarbeitet. Die Expression von transfizierten ENaC-Untereinheiten war in diesen Zellen deutlich erhöht, weswegen die Etablierung dieses Systems ausschlaggebend für weitere Versuche ist. Die vorliegende Arbeit beschreibt daher zum ersten Mal die nicht-virale, effiziente Transfektion von primären alveolaren Zellen und liefert damit ein bedeutendes neues Werkzeug für die Lungenforschung

    Common core assessments in follow-up studies of adults born preterm-Recommendation of the Adults Born Preterm International Collaboration

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    Of all newborns, 1%-2% are born very preterm (VP; <32 weeks) or with very low birthweight (VLBW; ≤1500 g). Advances in prenatal and neonatal care have substantially improved their survival, and the first generations who have benefited from these advances are now entering middle age. While most lead healthy lives, on average these adults are characterised by a number of adversities. These include cardiometabolic risk factors, airway obstruction, less physical activity, poorer visual function, lower cognitive performance, and a behavioural phenotype that includes inattention and internalising and socially withdrawn behaviour that may affect life chances and quality of life. Outcomes in later adulthood are largely unknown, and identifying trajectories of risk or resilience is essential in developing targeted interventions. Joint analyses of data and maintenance of follow-up of cohorts entering adulthood are essential. Such analyses are ongoing within the Adults Born Preterm International Collaboration (APIC; www.apic-preterm.org). Joint analyses require data harmonisation, highlighting the importance of consistent assessment methodologies. To present an expert recommendation on Common Core Assessments to be used in follow-up assessments of adults born preterm. Principles of Common Core Assessments were discussed at APIC meetings. Experts for each specific outcome domain wrote the first draft on assessments pertaining to that outcome. These drafts were combined and reviewed by all authors. Consensus was reached by discussion at APIC meetings. We present a recommendation by APIC experts on consistent measures to be used in adult follow-up assessments. The recommendation encompasses both "core" measures which we recommend to use in all assessments of adults born preterm that include the particular outcome. This will allow comparability between time and location. The recommendation also lists optional measures, focusing on current gaps in knowledge. It includes sections on study design, cardiometabolic and related biomarkers, biological samples, life style, respiratory, ophthalmic, cognitive, mental health, personality, quality of life, sociodemographics, social relationships, and reproduction. [Abstract copyright: © 2020 The Authors. Paediatric and Perinatal Epidemiology published by John Wiley & Sons Ltd.

    Neonatal brain tissue classification with morphological adaptation and unified segmentation

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    Measuring the distribution of brain tissue types (tissue classification) in neonates is necessary for studying typical and atypical brain development, such as that associated with preterm birth, and may provide biomarkers for neurodevelopmental outcomes. Compared with magnetic resonance images of adults, neonatal images present specific challenges that require the development of specialized, population-specific methods. This paper introduces MANTiS (Morphologically Adaptive Neonatal Tissue Segmentation), which extends the unified segmentation approach to tissue classification implemented in Statistical Parametric Mapping (SPM) software to neonates. MANTiS utilizes a combination of unified segmentation, template adaptation via morphological segmentation tools and topological filtering, to segment the neonatal brain into eight tissue classes: cortical gray matter, white matter, deep nuclear gray matter, cerebellum, brainstem, cerebrospinal fluid (CSF), hippocampus and amygdala. We evaluated the performance of MANTiS using two independent datasets. The first dataset, provided by the NeoBrainS12 challenge, consisted of coronal T2-weighted images of preterm infants (born ≤30 weeks’ gestation) acquired at 30 weeks’ corrected gestational age (n= 5), coronal T2-weighted images of preterm infants acquired at 40 weeks’ corrected gestational age (n= 5) and axial T2-weighted images of preterm infants acquired at 40 weeks’ corrected gestational age (n= 5). The second dataset, provided by the Washington University NeuroDevelopmental Research (WUNDeR) group, consisted of T2-weighted images of preterm infants (born <30 weeks’ gestation) acquired shortly after birth (n= 12), preterm infants acquired at term-equivalent age (n= 12), and healthy term-born infants (born ≥38 weeks’ gestation) acquired within the first nine days of life (n= 12). For the NeoBrainS12 dataset, mean Dice scores comparing MANTiS with manual segmentations were all above 0.7, except for the cortical gray matter for coronal images acquired at 30 weeks. This demonstrates that MANTiS’ performance is competitive with existing techniques. For the WUNDeR dataset, mean Dice scores comparing MANTiS with manually edited segmentations demonstrated good agreement, where all scores were above 0.75, except for the hippocampus and amygdala. The results show that MANTiS is able to segment neonatal brain tissues well, even in images that have brain abnormalities common in preterm infants. MANTiS is available for download as an SPM toolbox from http://developmentalimagingmcri.github.io/mantis

    Association between postnatal dexamethasone for treatment of bronchopulmonary dysplasia and brain volumes at adolescence in infants born very preterm

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    OBJECTIVES: To compare brain volumes in adolescents who were born extremely preterm (<28 weeks gestation) who had received postnatal dexamethasone, and to determine if there was a postnatal dexamethasone dose–response effect on brain volumes. STUDY DESIGN: Geographical cohort study of extremely preterm adolescents born in 1991-1992 in Victoria, Australia. T1-weighted magnetic resonance imaging was performed at 18 years of age. Segmented and parcellated brain volumes were calculated using an automated segmentation method (FreeSurfer) and compared between groups, with and without adjustment for potential confounders. The relationships between total postnatal dexamethasone dose and brain volumes were explored using linear regression. RESULTS: Of the 148 extremely preterm participants, 55 (37%) had received postnatal dexamethasone, with a cumulative mean dose of 7.7 mg/kg. Compared with participants who did not receive postnatal dexamethasone, those who did had smaller total brain tissue volumes (mean difference −3.6%, 95% CI [−7.0%, −0.3%], P value = .04) and smaller white matter, thalami, and basal ganglia volumes (all P < .05). There was a trend of smaller total brain and white matter volumes with increasing dose of postnatal dexamethasone (regression coefficient −7.7 [95% CI −16.2, 0.8] and −3.2 [−6.6, 0.2], respectively). CONCLUSIONS: Extremely preterm adolescents who received postnatal dexamethasone in the newborn period had smaller total brain tissue volumes than those who did not receive postnatal dexamethasone, particularly white matter, thalami, and basal ganglia. Vulnerability of brain tissues or structures associated with postnatal dexamethasone varies by structure and persists into adolescence

    Long term follow up of high risk children: who, why and how?

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    Background: Most babies are born healthy and grow and develop normally through childhood. There are, however, clearly identifiable high-risk groups of survivors, such as those born preterm or with ill-health, who are destined to have higher than expected rates of health or developmental problems, and for whom more structured and specialised follow-up programs are warranted. Discussion This paper presents the results of a two-day workshop held in Melbourne, Australia, to discuss neonatal populations in need of more structured follow-up and why, in addition to how, such a follow-up programme might be structured. Issues discussed included the ages of follow-up, and the personnel and assessment tools that might be required. Challenges for translating results into both clinical practice and research were identified. Further issues covered included information sharing, best practice for families and research gaps. Summary A substantial minority of high-risk children has long-term medical, developmental and psychological adverse outcomes and will consume extensive health and education services as they grow older. Early intervention to prevent adverse outcomes and the effective integration of services once problems are identified may reduce the prevalence and severity of certain outcomes, and will contribute to an efficient and effective use of health resources. The shared long-term goal for families and professionals is to work toward ensuring that high risk children maximise their potential and become productive and valued members of society. Electronic supplementary material The online version of this article (doi:10.1186/1471-2431-14-279) contains supplementary material, which is available to authorized users
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