212 research outputs found

    A three-year-old boy with X-linked adrenoleukodystrophy and congenital pulmonary adenomatoid malformation: a case report

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    Abstract Introduction X-linked adrenoleukodystrophy leads to demyelination of the nervous system, adrenal insufficiency, and accumulation of long-chain fatty acids. Most young patients with X-linked adrenoleukodystrophy develop seizures and progressive neurologic deficits, and die within the first two decades of life. Congenital or acquired disorders of the respiratory system have not been previously described in patients with X-linked adrenoleukodystrophy. Case presentation A 3-year-old Arabic boy from Yemen presented with discoloration of the mucous membranes and nail beds, which were considered cyanoses due to methemoglobinemia. He also had shortness of breath, fatigue, emesis and dehydration episodes for which he was admitted to our hospital. Chest radiograph and chest computed tomography scans showed congenital pulmonary adenomatoid malformation. A few weeks before the removal of the malformation, he had a significant episode of hypotension and hypoglycemia. This development required further in-hospital evaluation that led to the diagnosis of adrenal insufficiency and the initiation of treatment with corticosteroids. One year later, he developed seizures and loss of consciousness. Magnetic resonance imaging of his head showed diffuse demyelination secondary to X-linked adrenoleukodystrophy. He was treated with anti-seizure and anti-oxidants, and was referred for bone marrow transplant evaluation. Conclusion The presence of adrenal insufficiency, neurologic deficits and seizures are common manifestations of X-linked adrenoleukodystrophy. The association of congenital lung disease with X-linked adrenoleukodystrophy or Addison\u27s disease has not been described previously

    Bronchoalveolar lavage fluid from preterm infants with chorioamnionitis inhibits alveolar epithelial repair

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    <p>Abstract</p> <p>Background</p> <p>Preterm infants are highly susceptible to lung injury. While both chorioamnionitis and antenatal steroids induce lung maturation, chorioamnionitis is also associated with adverse lung development. We investigated the ability of bronchoalveolar lavage fluid (BALF) from ventilated preterm infants to restore alveolar epithelial integrity after injury <it>in vitro</it>, depending on whether or not they were exposed to chorioamnionitis or antenatal steroids. For this purpose, a translational model for alveolar epithelial repair was developed and characterised.</p> <p>Methods</p> <p>BALF was added to mechanically wounded monolayers of A549 cells. Wound closure was quantified over time and compared between preterm infants (gestational age < 32 wks) exposed or not exposed to chorioamnionitis and antenatal steroids (≥ 1 dose). Furthermore, keratinocyte growth factor (KGF) and vascular endothelial growth factor (VEGF) were quantified in BALF, and their ability to induce alveolar epithelial repair was evaluated in the model.</p> <p>Results</p> <p>On day 0/1, BALF from infants exposed to antenatal steroids significantly increased epithelial repair (40.3 ± 35.5 vs. -6.3 ± 75.0% above control/mg protein), while chorioamnionitis decreased wound-healing capacity of BALF (-2.9 ± 87.1 vs. 40.2 ± 36.9% above control/mg protein). BALF from patients with chorioamnionitis contained less KGF (11 (0-27) vs. 0 (0-4) pg/ml) and less detectable VEGF (66 vs. 95%) on day 0. BALF levels of VEGF and KGF correlated with its ability to induce wound repair. Moreover, KGF stimulated epithelial repair dose-dependently, although the low levels in BALF suggest KGF is not a major modulator of BALF-induced wound repair. VEGF also stimulated alveolar epithelial repair, an effect that was blocked by addition of soluble VEGF receptor-1 (sVEGFr1/Flt-1). However, BALF-induced wound repair was not significantly affected by addition of sVEGFr1.</p> <p>Conclusion</p> <p>Antenatal steroids improve the ability of BALF derived from preterm infants to stimulate alveolar epithelial repair <it>in vitro</it>. Conversely, chorioamnionitis is associated with decreased wound-healing capacity of BALF. A definite role for KGF and VEGF in either process could not be established. Decreased ability to induce alveolar epithelial repair after injury may contribute to the association between chorioamnionitis and adverse lung development in mechanically ventilated preterm infants.</p

    Comparison of machine learning and semi-quantification algorithms for (I123)FP-CIT classification: the beginning of the end for semi-quantification?

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    Background Semi-quantification methods are well established in the clinic for assisted reporting of (I123) Ioflupane images. Arguably, these are limited diagnostic tools. Recent research has demonstrated the potential for improved classification performance offered by machine learning algorithms. A direct comparison between methods is required to establish whether a move towards widespread clinical adoption of machine learning algorithms is justified. This study compared three machine learning algorithms with that of a range of semi-quantification methods, using the Parkinson’s Progression Markers Initiative (PPMI) research database and a locally derived clinical database for validation. Machine learning algorithms were based on support vector machine classifiers with three different sets of features: Voxel intensities Principal components of image voxel intensities Striatal binding radios from the putamen and caudate. Semi-quantification methods were based on striatal binding ratios (SBRs) from both putamina, with and without consideration of the caudates. Normal limits for the SBRs were defined through four different methods: Minimum of age-matched controls Mean minus 1/1.5/2 standard deviations from age-matched controls Linear regression of normal patient data against age (minus 1/1.5/2 standard errors) Selection of the optimum operating point on the receiver operator characteristic curve from normal and abnormal training data Each machine learning and semi-quantification technique was evaluated with stratified, nested 10-fold cross-validation, repeated 10 times. Results The mean accuracy of the semi-quantitative methods for classification of local data into Parkinsonian and non-Parkinsonian groups varied from 0.78 to 0.87, contrasting with 0.89 to 0.95 for classifying PPMI data into healthy controls and Parkinson’s disease groups. The machine learning algorithms gave mean accuracies between 0.88 to 0.92 and 0.95 to 0.97 for local and PPMI data respectively. Conclusions Classification performance was lower for the local database than the research database for both semi-quantitative and machine learning algorithms. However, for both databases, the machine learning methods generated equal or higher mean accuracies (with lower variance) than any of the semi-quantification approaches. The gain in performance from using machine learning algorithms as compared to semi-quantification was relatively small and may be insufficient, when considered in isolation, to offer significant advantages in the clinical context

    Comparative 3D analyses and palaeoecology of giant early amphibians (Temnospondyli: Stereospondyli)

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    Macroevolutionary, palaeoecological and biomechanical analyses in deep time offer the possibility to decipher the structural constraints, ecomorphological patterns and evolutionary history of extinct groups. Here, 3D comparative biomechanical analyses of the extinct giant early amphibian group of stereospondyls together with living lissamphibians and crocodiles, shows that: i) stereospondyls had peculiar palaeoecological niches with proper bites and stress patterns very different than those of giant salamanders and crocodiles; ii) their extinction may be correlated with the appearance of neosuchians, which display morphofunctional innovations. Stereospondyls weathered the end-Permian mass extinction, re-radiated, acquired gigantic sizes and dominated (semi) aquatic ecosystems during the Triassic. Because these ecosystems are today occupied by crocodilians, and stereospondyls are extinct amphibians, their palaeobiology is a matter of an intensive debate: stereospondyls were a priori compared with putative living analogous such as giant salamanders and/or crocodilians and our new results try to close this debate.Peer ReviewedPostprint (published version

    Ethnic Differences in Leaving Home: Timing and Pathways

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    The dynamics of leaving home for youth from migrant families in the Netherlands are examined using individual administrative data on the 1977 and 1983 birth cohorts for the period 1999–2004. A competing-risks approach is applied to distinguish leaving home for union formation, to live independently, and to share with others. Migrant youth, and particularly Turkish and Moroccan youth, leave home at a significantly younger age than Dutch youth, given the relevant background variables. This is remarkable, given the older ages at which young people in the origin countries leave the parental home. The result may be seen as evidence of how the potential effects of cultural norms are counter-affected by other factors, such as the facilities of the welfare state and the awkward position of migrant youth between two cultures. Considering the pathways out of home, the analysis largely confirms the expected pattern: Turkish and Moroccan youth leave home more often for union formation and particularly marriage, while this pathway is of minor importance for Dutch youth at early ages

    Spatial Variation in Foraging Behaviour of a Marine Top Predator (Phoca vitulina) Determined by a Large-Scale Satellite Tagging Program

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    The harbour seal (Phoca vitulina) is a widespread marine predator in Northern Hemisphere waters. British populations have been subject to rapid declines in recent years. Food supply or inter-specific competition may be implicated but basic ecological data are lacking and there are few studies of harbour seal foraging distribution and habits. In this study, satellite tagging conducted at the major seal haul outs around the British Isles showed both that seal movements were highly variable among individuals and that foraging strategy appears to be specialized within particular regions. We investigated whether these apparent differences could be explained by individual level factors: by modelling measures of trip duration and distance travelled as a function of size, sex and body condition. However, these were not found to be good predictors of foraging trip duration or distance, which instead was best predicted by tagging region, time of year and inter-trip duration. Therefore, we propose that local habitat conditions and the constraints they impose are the major determinants of foraging movements. Specifically the distance to profitable feeding grounds from suitable haul-out locations may dictate foraging strategy and behaviour. Accounting for proximity to productive foraging resources is likely to be an important component of understanding population processes. Despite more extensive offshore movements than expected, there was also marked fidelity to the local haul-out region with limited connectivity between study regions. These empirical observations of regional exchange at short time scales demonstrates the value of large scale electronic tagging programs for robust characterization of at-sea foraging behaviour at a wide spatial scale

    Epigenetic Effects of Prenatal Stress on 11β-Hydroxysteroid Dehydrogenase-2 in the Placenta and Fetal Brain

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    Maternal exposure to stress during pregnancy is associated with significant alterations in offspring neurodevelopment and elevated maternal glucocorticoids likely play a central role in mediating these effects. Placental 11β-hydroxysteroid dehydrogenase type 2 (HSD11B2) buffers the impact of maternal glucocorticoid exposure by converting cortisol/corticosterone into inactive metabolites. However, previous studies indicate that maternal adversity during the prenatal period can lead to a down-regulation of this enzyme. In the current study, we examined the impact of prenatal stress (chronic restraint stress during gestational days 14–20) in Long Evans rats on HSD11B2 mRNA in the placenta and fetal brain (E20) and assessed the role of epigenetic mechanisms in these stress-induced effects. In the placenta, prenatal stress was associated with a significant decrease in HSD11B2 mRNA, increased mRNA levels of the DNA methyltransferase DNMT3a, and increased DNA methylation at specific CpG sites within the HSD11B2 gene promoter. Within the fetal hypothalamus, though we find no stress-induced effects on HSD11B2 mRNA levels, prenatal stress induced decreased CpG methylation within the HSD11B2 promoter and increased methylation at sites within exon 1. Within the fetal cortex, HSD11B2 mRNA and DNA methylation levels were not altered by prenatal stress, though we did find stress-induced elevations in DNMT1 mRNA in this brain region. Within individuals, we identified CpG sites within the HSD11B2 gene promoter and exon 1 at which DNA methylation levels were highly correlated between the placenta and fetal cortex. Overall, our findings implicate DNA methylation as a mechanism by which prenatal stress alters HSD11B2 gene expression. These findings highlight the tissue specificity of epigenetic effects, but also raise the intriguing possibility of using the epigenetic status of placenta to predict corresponding changes in the brain

    How does fiction reading influence empathy? An experimental investigation on the role of emotional transportation

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    The current study investigated whether fiction experiences change empathy of the reader. Based on transportation theory, it was predicted that when people read fiction, and they are emotionally transported into the story, they become more empathic. Two experiments showed that empathy was influenced over a period of one week for people who read a fictional story, but only when they were emotionally transported into the story. No transportation led to lower empathy in both studies, while study 1 showed that high transportation led to higher empathy among fiction readers. These effects were not found for people in the control condition where people read non-fiction. The study showed that fiction influences empathy of the reader, but only under the condition of low or high emotional transportation into the story

    The human capital transition and the role of policy

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    Along with information and communication technology, infrastructure, and the innovation system, human capital is a key pillar of the knowledge economy with its scope for increasing returns. With this in mind, the purpose of this chapter is to investigate how industrialized economies managed to achieve the transition from low to high levels of human capital. The first phase of the human capital transition was the result of the interaction of supply and demand, triggered by technological change and boosted by the demands for (immaterial) services. The second phase of the human capital transition (i.e., mass education) resulted from enforced legislation and major public investment. The state’s aim to influence children’s beliefs appears to have been a key driver in public investment. Nevertheless, the roles governments played differed according to the developmental status and inherent socioeconomic and political characteristics of their countries. These features of the human capital transition highlight the importance of understanding governments’ incentives and roles in transitions

    Man and the Last Great Wilderness: Human Impact on the Deep Sea

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    The deep sea, the largest ecosystem on Earth and one of the least studied, harbours high biodiversity and provides a wealth of resources. Although humans have used the oceans for millennia, technological developments now allow exploitation of fisheries resources, hydrocarbons and minerals below 2000 m depth. The remoteness of the deep seafloor has promoted the disposal of residues and litter. Ocean acidification and climate change now bring a new dimension of global effects. Thus the challenges facing the deep sea are large and accelerating, providing a new imperative for the science community, industry and national and international organizations to work together to develop successful exploitation management and conservation of the deep-sea ecosystem. This paper provides scientific expert judgement and a semi-quantitative analysis of past, present and future impacts of human-related activities on global deep-sea habitats within three categories: disposal, exploitation and climate change. The analysis is the result of a Census of Marine Life – SYNDEEP workshop (September 2008). A detailed review of known impacts and their effects is provided. The analysis shows how, in recent decades, the most significant anthropogenic activities that affect the deep sea have evolved from mainly disposal (past) to exploitation (present). We predict that from now and into the future, increases in atmospheric CO2 and facets and consequences of climate change will have the most impact on deep-sea habitats and their fauna. Synergies between different anthropogenic pressures and associated effects are discussed, indicating that most synergies are related to increased atmospheric CO2 and climate change effects. We identify deep-sea ecosystems we believe are at higher risk from human impacts in the near future: benthic communities on sedimentary upper slopes, cold-water corals, canyon benthic communities and seamount pelagic and benthic communities. We finalise this review with a short discussion on protection and management methods
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