567 research outputs found

    Hermansky-Pudlak syndrome type 2 manifests with fibrosing lung disease early in childhood

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    Background: Hermansky-Pudlak syndrome (HPS), a hereditary multisystem disorder with oculocutaneous albinism, may be caused by mutations in one of at least 10 separate genes. The HPS-2 subtype is distinguished by the presence of neutropenia and knowledge of its pulmonary phenotype in children is scarce. Methods: Six children with genetically proven HPS-2 presented to the chILD-EU register between 2009 and 2017; the data were collected systematically and imaging studies were scored blinded. Results: Pulmonary symptoms including dyspnea, coughing, need for oxygen, and clubbing started 3.3 years before the diagnosis was made at the mean age of 8.83 years (range 2-15). All children had recurrent pulmonary infections, 3 had a spontaneous pneumothorax, and 4 developed scoliosis. The frequency of pulmonary complaints increased over time. The leading radiographic pattern was ground-glass opacities with a rapid increase in reticular pattern and traction bronchiectasis between initial and follow-up Computer tomography (CT) in all subjects. Honeycombing and cysts were newly detectable in 3 patients. Half of the patients received a lung biopsy for diagnosis; histological patterns were cellular non-specific interstitial pneumonia, usual interstitial pneumonia-like, and desquamative interstitial pneumonia. Conclusions: HPS-2 is characterized by a rapidly fibrosing lung disease during early childhood. Effective treatments are required

    Specialized interfaces of Smc5/6 control hinge stability and DNA association

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    The Structural Maintenance of Chromosomes (SMC) complexes: cohesin, condensin and Smc5/6 are involved in the organization of higher-order chromosome structure—which is essential for accurate chromosome duplication and segregation. Each complex is scaffolded by a specific SMC protein dimer (heterodimer in eukaryotes) held together via their hinge domains. Here we show that the Smc5/6-hinge, like those of cohesin and condensin, also forms a toroidal structure but with distinctive subunit interfaces absent from the other SMC complexes; an unusual ‘molecular latch’ and a functional ‘hub’. Defined mutations in these interfaces cause severe phenotypic effects with sensitivity to DNA-damaging agents in fission yeast and reduced viability in human cells. We show that the Smc5/6-hinge complex binds preferentially to ssDNA and that this interaction is affected by both ‘latch’ and ‘hub’ mutations, suggesting a key role for these unique features in controlling DNA association by the Smc5/6 complex

    Shyness and engagement: Contributions of peer rejection and teacher sensitivity

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    This study tested a longitudinal model of mediated moderation for the role of temperament and shyness in the development of young children’s (n = 960, aged 54 mos. to 1st grade [SD = 1.08 at 54 mos.]) peer relationships at school and linkages to subsequent academic engagement. Teacher sensitivity was examined as a parallel predictor of peer relationship effects and subsequent engagement, and we examined whether or not adverse effects of shyness on peer relationships and adjustment were stronger in classrooms where teachers displayed lower sensitivity. Findings indicated that peer rejection mediated the association between children’s shyness at preschool age and engagement in first grade and that teacher sensitivity, although not directly related to peer rejection, was positively related to engagement. Finally, teacher sensitivity moderated the association between shyness, peer rejection, and classroom engagement. Results suggested that teacher sensitivity plays a role in linkages between shyness and peer rejection. Teacher sensitivity may moderate effects on engagement and function as an important aspect of supportive contexts for shy children

    Shyness and engagement: Contributions of peer rejection and teacher sensitivity

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    This study tested a longitudinal model of mediated moderation for the role of temperament and shyness in the development of young children’s (n = 960, aged 54 mos. to 1st grade [SD = 1.08 at 54 mos.]) peer relationships at school and linkages to subsequent academic engagement. Teacher sensitivity was examined as a parallel predictor of peer relationship effects and subsequent engagement, and we examined whether or not adverse effects of shyness on peer relationships and adjustment were stronger in classrooms where teachers displayed lower sensitivity. Findings indicated that peer rejection mediated the association between children’s shyness at preschool age and engagement in first grade and that teacher sensitivity, although not directly related to peer rejection, was positively related to engagement. Finally, teacher sensitivity moderated the association between shyness, peer rejection, and classroom engagement. Results suggested that teacher sensitivity plays a role in linkages between shyness and peer rejection. Teacher sensitivity may moderate effects on engagement and function as an important aspect of supportive contexts for shy children

    Surfactant proteins SP-B and SP-C and their precursors in bronchoalveolar lavages from children with acute and chronic inflammatory airway disease

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    <p>Abstract</p> <p>Background</p> <p>The surfactant proteins B (SP-B) and C (SP-C) are important for the stability and function of the alveolar surfactant film. Their involvement and down-regulation in inflammatory processes has recently been proposed, but their level during neutrophilic human airway diseases are not yet known.</p> <p>Methods</p> <p>We used 1D-electrophoresis and Western blotting to determine the concentrations and molecular forms of SP-B and SP-C in bronchoalveolar lavage (BAL) fluid of children with different inflammatory airway diseases. 21 children with cystic fibrosis, 15 with chronic bronchitis and 14 with pneumonia were included and compared to 14 healthy control children.</p> <p>Results</p> <p>SP-B was detected in BAL of all 64 patients, whereas SP-C was found in BAL of all but 3 children; those three BAL fluids had more than 80% neutrophils, and in two patients, who were re-lavaged later, SP-C was then present and the neutrophil count was lower. SP-B was mainly present as a dimer, SP-C as a monomer. For both qualitative and quantitative measures of SP-C and SP-B, no significant differences were observed between the four evaluated patient groups.</p> <p>Conclusion</p> <p>Concentration or molecular form of SP-B and SP-C is not altered in BAL of children with different acute and chronic inflammatory lung diseases. We conclude that there is no down-regulation of SP-B and SP-C at the protein level in inflammatory processes of neutrophilic airway disease.</p

    Surfactant phosphatidylcholine half-life and pool size measurements in premature baboons developing bronchopulmonary dysplasia

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    Because minimal information is available about surfactant metabolism in bronchopulmonary dysplasia, we measured half-lives and pool sizes of surfactant phosphatidylcholine in very preterm baboons recovering from respiratory distress syndrome and developing bronchopulmonary dysplasia, using stable isotopes, radioactive isotopes, and direct pool size measurements. Eight ventilated premature baboons received (2)H-DPPC (dipalmitoyl phosphatidylcholine) on d 5 of life, and radioactive (14)C-DPPC with a treatment dose of surfactant on d 8. After 14 d, lung pool sizes of saturated phosphatidylcholine were measured. Half-life of (2)H-DPPC (d 5) in tracheal aspirates was 28 +/- 4 h (mean +/- SEM). Half-life of radioactive DPPC (d 8) was 35 +/- 4 h. Saturated phosphatidylcholine pool size measured with stable isotopes on d 5 was 129 +/- 14 micro mol/kg, and 123 +/- 11 micro mol/kg on d 14 at autopsy. Half-lives were comparable to those obtained at d 0 and d 6 in our previous baboon studies. We conclude that surfactant metabolism does not change during the early development of bronchopulmonary dysplasia, more specifically, the metabolism of exogenous surfactant on d 8 is similar to that on the day of birth. Surfactant pool size is low at birth, increases after surfactant therapy, and is kept constant during the first 2 wk of life by endogenous surfactant synthesis. Measurements with stable isotopes are comparable to measurements with radioactive tracers and measurements at autopsy

    Determination of nutrient salts by automatic methods both in seawater and brackish water: the phosphate blank

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    9 páginas, 2 tablas, 2 figurasThe main inconvenience in determining nutrients in seawater by automatic methods is simply solved: the preparation of a suitable blank which corrects the effect of the refractive index change on the recorded signal. Two procedures are proposed, one physical (a simple equation to estimate the effect) and the other chemical (removal of the dissolved phosphorus with ferric hydroxide).Support for this work came from CICYT (MAR88-0245 project) and Conselleria de Pesca de la Xunta de GaliciaPeer reviewe

    Radio Galaxy Classification with wGAN-Supported Augmentation

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    Novel techniques are indispensable to process the flood of data from the new generation of radio telescopes. In particular, the classification of astronomical sources in images is challenging. Morphological classification of radio galaxies could be automated with deep learning models that require large sets of labelled training data. Here, we demonstrate the use of generative models, specifically Wasserstein GANs (wGAN), to generate artificial data for different classes of radio galaxies. Subsequently, we augment the training data with images from our wGAN. We find that a simple fully-connected neural network for classification can be improved significantly by including generated images into the training set.Comment: 10 pages, 6 figures; accepted to ml.astro; v2: matches published versio

    Expression profiles of hydrophobic surfactant proteins in children with diffuse chronic lung disease

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    BACKGROUND: Abnormalities of the intracellular metabolism of the hydrophobic surfactant proteins SP-B and SP-C and their precursors may be causally linked to chronic childhood diffuse lung diseases. The profile of these proteins in the alveolar space is unknown in such subjects. METHODS: We analyzed bronchoalveolar lavage fluid by Western blotting for SP-B, SP-C and their proforms in children with pulmonary alveolar proteinosis (PAP, n = 15), children with no SP-B (n = 6), children with chronic respiratory distress of unknown cause (cRD, n = 7), in comparison to children without lung disease (n = 15) or chronic obstructive bronchitis (n = 19). RESULTS: Pro-SP-B of 25–26 kD was commonly abundant in all groups of subjects, suggesting that their presence is not of diagnostic value for processing defects. In contrast, pro-SP-B peptides cleaved off during intracellular processing of SP-B and smaller than 19–21 kD, were exclusively found in PAP and cRD. In 4 of 6 children with no SP-B, mutations of SFTPB or SPTPC genes were found. Pro-SP-C forms were identified at very low frequency. Their presence was clearly, but not exclusively associated with mutations of the SFTPB and SPTPC genes, impeding their usage as candidates for diagnostic screening. CONCLUSION: Immuno-analysis of the hydrophobic surfactant proteins and their precursor forms in bronchoalveolar lavage is minimally invasive and can give valuable clues for the involvement of processing abnormalities in pediatric pulmonary disorders
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