623 research outputs found

    Randomized crossover comparison of proportional assist ventilation and patient-triggered ventilation in extremely low birth weight infants with evolving chronic lung disease

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    Background: Refinement of ventilatory techniques remains a challenge given the persistence of chronic lung disease of preterm infants. Objective: To test the hypothesis that proportional assist ventilation ( PAV) will allow to lower the ventilator pressure at equivalent fractions of inspiratory oxygen (FiO(2)) and arterial hemoglobin oxygen saturation in ventilator-dependent extremely low birth weight infants in comparison with standard patient-triggered ventilation ( PTV). Methods: Design: Randomized crossover design. Setting: Two level-3 university perinatal centers. Patients: 22 infants ( mean (SD): birth weight, 705 g ( 215); gestational age, 25.6 weeks ( 2.0); age at study, 22.9 days ( 15.6)). Interventions: One 4- hour period of PAV was applied on each of 2 consecutive days and compared with epochs of standard PTV. Results: Mean airway pressure was 5.64 ( SD, 0.81) cm H2O during PAV and 6.59 ( SD, 1.26) cm H2O during PTV ( p < 0.0001), the mean peak inspiratory pressure was 10.3 ( SD, 2.48) cm H2O and 15.1 ( SD, 3.64) cm H2O ( p < 0.001), respectively. The FiO(2) ( 0.34 (0.13) vs. 0.34 ( 0.14)) and pulse oximetry readings were not significantly different. The incidence of arterial oxygen desaturations was not different ( 3.48 ( 3.2) vs. 3.34 ( 3.0) episodes/ h) but desaturations lasted longer during PAV ( 2.60 ( 2.8) vs. 1.85 ( 2.2) min of desaturation/ h, p = 0.049). PaCO2 measured transcutaneously in a subgroup of 12 infants was similar. One infant met prespecified PAV failure criteria. No adverse events occurred during the 164 cumulative hours of PAV application. Conclusions: PAV safely maintains gas exchange at lower mean airway pressures compared with PTV without adverse effects in this population. Backup conventional ventilation breaths must be provided to prevent apnea-related desaturations. Copyright (c) 2007 S. Karger AG, Base

    Coronin 7, the mammalian POD-1 homologue, localizes to the Golgi apparatus

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    AbstractCoronins constitute an evolutionary conserved family of WD-repeat actin-binding proteins. Their primary function is thought to be regulating the actin cytoskeleton. Apart from that, several coronins were indirectly shown to participate in vesicular transport, establishment of cell polarity and cytokinesis. Here, we report a novel mammalian protein, coronin 7 (crn7), which is significantly different from other mammalian coronins in its domain architecture. Crn7 possesses two stretches of WD repeats in contrast to the other coronins only having one. The protein is expressed throughout the mouse embryogenesis and is strongly upregulated in brain and developing structures of the immune system in the course of development. In adult animals, both crn7 mRNA and protein are abundantly present in most organs, with significantly higher amounts in brain, kidney, thymus and spleen and lower amounts in muscle. At the subcellular level, the bulk of the protein appears to be present in the cytosol and in large cytosolic complexes. However, a significant portion of the protein is detected on vesicle-like cytoplasmic structures as well as on the cis-Golgi. In the Golgi region, crn7 staining appears broader than that of the cis-Golgi markers Erd2p and β-COP, still, the trans-Golgi network appears predominantly crn7-negative. Importantly, the membrane-associated form of crn7 protein is phosphorylated on tyrosine residues, whereas the cytosolic form is not. Crn7 is the first coronin protein proven to localize to the Golgi membrane. We conclude that it plays a role in the organization of intracellular membrane compartments and vesicular trafficking rather than in remodeling the cytoskeleton

    Do Quiescent and Active Galaxies Have Different M_(BH)-σ* Relations?

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    To investigate the validity of the assumption that quiescent galaxies and active galaxies follow the same black hole mass (M_BH)-stellar velocity dispersion (σ*) relation, as required for the calibration of M_BH estimators for broad line active galactic nuclei (AGNs), we determine and compare the M_BH-σ* relations, respectively, for quiescent and active galaxies. For the quiescent galaxy sample, composed of 72 dynamical M_BH measurements, we update σ* for 28 galaxies using homogeneous H-band measurements that are corrected for galaxy rotation. For active galaxies, we collect 25 reverberation-mapped AGNs and improve σ* measurement for two objects. Combining the two samples, we determine the virial factor f, first by scaling the active galaxy sample to the M_BH-σ* relation of quiescent galaxies, and second by simultaneously fitting the quiescent and active galaxy samples, as f=5.1^(+1.5)_(-1.1) and f=5.9^(+2.1)_(-1.5), respectively. The M_BH-σ* relation of active galaxies appears to be shallower than that of quiescent galaxies. However, the discrepancy is caused by a difference in the accessible M_BH distribution at given σ*, primarily due to the difficulty of measuring reliable stellar velocity dispersion for the host galaxies of luminous AGNs. Accounting for the selection effects, we find that active and quiescent galaxies are consistent with following intrinsically the same M_BH-σ* relation

    Calibrating Stellar Velocity Dispersions Based on Spatially Resolved H-band Spectra for Improving the M_(BH)-σ_* Relation

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    To calibrate stellar velocity dispersion measurements from optical and near-IR stellar lines, and to improve the black hole mass (M_(BH))-stellar velocity dispersion (σ_*) relation, we measure σ_* based on high-quality H-band spectra for a sample of 31 nearby galaxies, for which dynamical M_(BH) is available in the literature. By comparing velocity dispersions measured from stellar lines in the H-band with those measured from optical stellar lines, we find no significant difference, suggesting that optical and near-IR stellar lines represent the same kinematics and that dust effect is negligible for early-type galaxies. Based on the spatially resolved rotation and velocity dispersion measurements along the major axis of each galaxy, we find that a rotating stellar disk is present for 80% of galaxies in the sample. For galaxies with a rotation component, σ_* measured from a single aperture spectrum can vary by up to ~20%, depending on the size of the adopted extraction aperture. To correct for the rotational broadening, we derive luminosity-weighted σ_* within the effective radius of each galaxy, providing uniformly measured velocity dispersions to improve the M_(BH)-σ_* relation

    Clinically stable very low birthweight infants are at risk for recurrent tissue glucose fluctuations even after fully established enteral nutrition

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    Objective: In previous cases, we have observed occasional hypoglycaemic episodes in preterm infants after initial intensive care. In this prospective study, we determined the frequency and severity of abnormal tissue glucose (TG) in clinically stable preterm infants on full enteral nutrition. Methods: Preterm infants born at <1000 g (n=23; G1) and birth weight 1000–1500 g (n=18; G2) were studied at a postmenstrual age of 32±2 weeks (G1) and 33±2 weeks (G2). Infants were fed two or three hourly, according to a standard bolus-nutrition protocol, and continuous subcutaneous glucose measurements were performed for 72 h. Normal glucose values were assumed at ≥2.5 mmol/L (45 mg/dL) and ≤8.3 mmol/L (150 mg/dL). Frequency, severity and duration of glucose values beyond normal values were determined. Results: We observed asymptomatic low TG values in 39% of infants in G1 and in 44% in G2. High TG values were detected in 83% in G1 and 61% in G2. Infants in G1 experienced prolonged and more severe low TG episodes, and also more frequent and severe high TG episodes. In G1 and G2, 87% and 67% of the infants, respectively, showed glucose fluctuations characterised by rapid glucose increase followed by a rapid glucose drop after feeds. In more mature infants, glucose fluctuations were less pronounced and less dependent on enteral feeds. Conclusions: Clinically stable well-developing preterm infants beyond their initial period of intensive care show interstitial glucose instabilities exceeding values as low as 2.5 mmol/L and as high as 8.3 mmol/L. This novel observation may play an important role for the susceptibility of these high-risk infants for the development of the metabolic syndrome

    Cannabidiol for Treatment of Childhood Epilepsy–A Cross-Sectional Survey

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    Background: The interest in cannabidiol (CBD) for treatment of epilepsy has been increasing over the last years. However, practitioner's attitudes concerning the use of CBD for epilepsy treatment appears to be divided and data about its clinical use in daily practice are not available.Objective: To improve the knowledge about the current use of CBD amongst European practitioners treating children and adolescents for epilepsy.Methods: Cross-sectional survey using an open-access online questionnaire for physicians treating children or adolescents for epilepsy within eight European countries from December 2017 to March 2018.Results: One-hundred fifty-five physicians participated in the survey. CBD is increasingly used by 45% (69/155) of participants, treating a mean (range) number of 3 (1–35) with CBD. Only 48% of the participants prescribing CBD are exclusively using purified CBD to treat children and adolescents with epilepsy, the remainder also applies preparations containing delta9-tetrahydrocannabinol (THC). Reported daily CBD doses range from &lt; 10 to 50 mg/kg body weight. Management of CBD therapy in regard of monitoring side effects and adjusting concomitant therapy differs widely amongst participants. Their primary objective for commencing CBD is improving patient's quality of life. Participants frequently receive inquiries about CBD treatment but only 40% may actively suggest CBD as a treatment option. Of the 85 participants currently not using CBD for epilepsy treatment, 70% would consider using CBD if available in their country of practice or given the opportunity to become familiar with this treatment option.Conclusions: CBD is increasingly used by participating physicians but individual experience remains limited. There are very diverse opinions about the use of CBD to treat epilepsy in children and adolescents and widely differing views on how to manage the CBD treatment

    The Sloan Digital Sky Survey Reverberation Mapping Project: No Evidence for Evolution in the M-sigma Relation to z~1

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    We present host stellar velocity dispersion measurements for a sample of 88 broad-line quasars at 0.10.6) from the Sloan Digital Sky Survey Reverberation Mapping (SDSS-RM) project. High signal-to-noise ratio coadded spectra (average S/N~30 per 69 km/s pixel) from SDSS-RM allowed decomposition of the host and quasar spectra, and measurement of the host stellar velocity dispersions and black hole (BH) masses using the single-epoch (SE) virial method. The large sample size and dynamic range in luminosity (L5100=10^(43.2-44.7) erg/s) lead to the first clear detection of a correlation between SE virial BH mass and host stellar velocity dispersion far beyond the local universe. However, the observed correlation is significantly flatter than the local relation, suggesting that there are selection biases in high-z luminosity-threshold quasar samples for such studies. Our uniform sample and analysis enable an investigation of the redshift evolution of the M-sigma relation free of caveats by comparing different samples/analyses at disjoint redshifts. We do not observe evolution of the M-sigma relation in our sample, up to z~1, but there is an indication that the relation flattens towards higher redshifts. Coupled with the increasing threshold luminosity with redshift in our sample, this again suggests certain selection biases are at work, and simple simulations demonstrate that a constant M-sigma relation is favored to z~1. Our results highlight the scientific potential of deep coadded spectroscopy from quasar monitoring programs, and offer a new path to probe the co-evolution of BHs and galaxies at earlier times.Comment: replaced with the accepted version (minor changes and updated references); ApJ in press; changed title to highlight the main resul

    Controversies on the network theory of epilepsy : Debates held during the ICTALS 2019 conference

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    Acknowledgements We would like to acknowledge the contributions of the discussants to the exposition and discussion of the six debate topics. The discussants for debates 1-6 were Fabrice Wendling, Mark Cook, Mark Richardson, Thorsten Rings, Klaus Lehnertz and Piotr Suffczynski, respectively. Funding for ICTALS 2019 was received from the following foundations and industry partners: UCB S.A. (Belgium), American Epilepsy Society (AES), Epilepsy Innovation Institute (Ei2) and Epilepsy Foundation of America (EFA), NeuraLynx (Bozeman, MT, USA) and LivaNova (London, UK). The contribution of HZ was supported by award R01NS109062 from the National Institutes of Health, MG by the EPSRC via grants EP/P021417/1 and EP/N014391/1 and a Wellcome Trust Institutional Strategic Support Award (WT105618MA), and PJ by awards from the Ministry of Health of the Czech Republic AZV 17-28427A and the Czech Science Foundation 20-25298S. The opinions expressed in this article do not necessarily reflect the view of the National Institutes of Health, the Department of Health and Human Services, or the United States government.Peer reviewedPostprin
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