152 research outputs found

    Current Status of Extracorporeal Membrane Oxygenation for Severe Respiratory Failure

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    Extracorporeal membrane oxygenation (ECMO) for respiratory failure was reviewed. ECMO progressed from laboratory research to initial clinical trials in 1972. Following a decade of clinical research, ECMO is now standard treatment for neonatal respiratory failure refractory to conventional pulmonary support techniques worldwide. The application of neonatal ECMO has been extended with improved outcome to premature and low birth weight infants as well as older children and adults. As of July 1994, 9,258 neonates, 754 pediatric, and 130 adult patients with respiratory failure treated with ECMO were entered in the registry of the Extracorporeal Life Support Organization (ELSO). Overall survival rates were 81 in neonates, 49 in pediatric, and 38 in adult patients. Recently the adult and pediatric populations treated with ECMO have increased rapidly, and the outcome has improved significantly.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73707/1/j.1525-1594.1996.tb00712.x.pd

    Propagation of chaos for rank-based interacting diffusions and long time behaviour of a scalar quasilinear parabolic equation

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    We study a quasilinear parabolic Cauchy problem with a cumulative distribution function on the real line as an initial condition. We call 'probabilistic solution' a weak solution which remains a cumulative distribution function at all times. We prove the uniqueness of such a solution and we deduce the existence from a propagation of chaos result on a system of scalar diffusion processes, the interactions of which only depend on their ranking. We then investigate the long time behaviour of the solution. Using a probabilistic argument and under weak assumptions, we show that the flow of the Wasserstein distance between two solutions is contractive. Under more stringent conditions ensuring the regularity of the probabilistic solutions, we finally derive an explicit formula for the time derivative of the flow and we deduce the convergence of solutions to equilibrium.Comment: Stochastic partial differential equations: analysis and computations (2013) http://dx.doi.org/10.1007/s40072-013-0014-

    Optimal Protocol for Contrast-enhanced Free-running 5D Whole-heart Coronary MR Angiography at 3T.

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    Free-running 5D whole-heart coronary MR angiography (MRA) is gaining in popularity because it reduces scanning complexity by removing the need for specific slice orientations, respiratory gating, or cardiac triggering. At 3T, a gradient echo (GRE) sequence is preferred in combination with contrast injection. However, neither the injection scheme of the gadolinium (Gd) contrast medium, the choice of the RF excitation angle, nor the dedicated image reconstruction parameters have been established for 3T GRE free-running 5D whole-heart coronary MRA. In this study, a Gd injection scheme, RF excitation angles of lipid-insensitive binominal off-resonance RF excitation (LIBRE) pulse for valid fat suppression and continuous data acquisition, and compressed-sensing reconstruction regularization parameters were optimized for contrast-enhanced free-running 5D whole-heart coronary MRA using a GRE sequence at 3T. Using this optimized protocol, contrast-enhanced free-running 5D whole-heart coronary MRA using a GRE sequence is feasible with good image quality at 3T

    Magnesium induces neuronal apoptosis by suppressing excitability

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    In clinical obstetrics, magnesium sulfate (MgSO4) use is widespread, but effects on brain development are unknown. Many agents that depress neuronal excitability increase developmental neuroapoptosis. In this study, we used dissociated cultures of rodent hippocampus to examine the effects of Mg++ on excitability and survival. Mg++-induced caspase-3-associated cell loss at clinically relevant concentrations. Whole-cell patch-clamp techniques measured Mg++ effects on action potential threshold, action potential peak amplitude, spike number and changes in resting membrane potential. Mg++ depolarized action potential threshold, presumably from surface charge screening effects on voltage-gated sodium channels. Mg++ also decreased the number of action potentials in response to fixed current injection without affecting action potential peak amplitude. Surprisingly, Mg++ also depolarized neuronal resting potential in a concentration-dependent manner with a +5.2 mV shift at 10 mM. Voltage ramps suggested that Mg++ blocked a potassium conductance contributing to the resting potential. In spite of this depolarizing effect of Mg++, the net inhibitory effect of Mg++ nearly completely silenced neuronal network activity measured with multielectrode array recordings. We conclude that although Mg++ has complex effects on cellular excitability, the overall inhibitory influence of Mg++ decreases neuronal survival. Taken together with recent in vivo evidence, our results suggest that caution may be warranted in the use of Mg++ in clinical obstetrics and neonatology

    Crk and CrkL adaptor proteins: networks for physiological and pathological signaling

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    The Crk adaptor proteins (Crk and CrkL) constitute an integral part of a network of essential signal transduction pathways in humans and other organisms that act as major convergence points in tyrosine kinase signaling. Crk proteins integrate signals from a wide variety of sources, including growth factors, extracellular matrix molecules, bacterial pathogens, and apoptotic cells. Mounting evidence indicates that dysregulation of Crk proteins is associated with human diseases, including cancer and susceptibility to pathogen infections. Recent structural work has identified new and unusual insights into the regulation of Crk proteins, providing a rationale for how Crk can sense diverse signals and produce a myriad of biological responses

    Expression Profiling of Major Histocompatibility and Natural Killer Complex Genes Reveals Candidates for Controlling Risk of Graft versus Host Disease

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    Background: The major histocompatibility complex (MHC) is the most important genomic region that contributes to the risk of graft versus host disease (GVHD) after haematopoietic stem cell transplantation. Matching of MHC class I and II genes is essential for the success of transplantation. However, the MHC contains additional genes that also contribute to the risk of developing acute GVHD. It is difficult to identify these genes by genetic association studies alone due to linkage disequilibrium in this region. Therefore, we aimed to identify MHC genes and other genes involved in the pathophysiology of GVHD by mRNA expression profiling. Methodology/Principal Findings: To reduce the complexity of the task, we used genetically well-defined rat inbred strains and a rat skin explant assay, an in-vitro-model of the graft versus host reaction (GVHR), to analyze the expression of MHC, natural killer complex (NKC), and other genes in cutaneous GVHR. We observed a statistically significant and strong up or down regulation of 11 MHC, 6 NKC, and 168 genes encoded in other genomic regions, i.e. 4.9%, 14.0%, and 2.6% of the tested genes respectively. The regulation of 7 selected MHC and 3 NKC genes was confirmed by quantitative real-time PCR and in independent skin explant assays. In addition, similar regulations of most of the selected genes were observed in GVHD-affected skin lesions of transplanted rats and in human skin explant assays. Conclusions/Significance: We identified rat and human MHC and NKC genes that are regulated during GVHR in skin explant assays and could therefore serve as biomarkers for GVHD. Several of the respective human genes, including HLA-DMB, C2, AIF1, SPR1, UBD, and OLR1, are polymorphic. These candidates may therefore contribute to the genetic risk of GVHD in patients

    Human cytomegalovirus immediate-early 1 protein rewires upstream STAT3 to downstream STAT1 signaling switching an IL6-type to an IFNγ-like response

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    MN and CP were supported by the Wellcome Trust (www.wellcome.ac.uk) Institutional Strategic Support Fund and CP was supported by the Deutsche Forschungsgemeinschaft (PA 815/2-1; www.dfg.de).The human cytomegalovirus (hCMV) major immediate-early 1 protein (IE1) is best known for activating transcription to facilitate viral replication. Here we present transcriptome data indicating that IE1 is as significant a repressor as it is an activator of host gene expression. Human cells induced to express IE1 exhibit global repression of IL6- and oncostatin M-responsive STAT3 target genes. This repression is followed by STAT1 phosphorylation and activation of STAT1 target genes normally induced by IFNγ. The observed repression and subsequent activation are both mediated through the same region (amino acids 410 to 445) in the C-terminal domain of IE1, and this region serves as a binding site for STAT3. Depletion of STAT3 phenocopies the STAT1-dependent IFNγ-like response to IE1. In contrast, depletion of the IL6 receptor (IL6ST) or the STAT kinase JAK1 prevents this response. Accordingly, treatment with IL6 leads to prolonged STAT1 instead of STAT3 activation in wild-type IE1 expressing cells, but not in cells expressing a mutant protein (IE1dl410-420) deficient for STAT3 binding. A very similar STAT1-directed response to IL6 is also present in cells infected with a wild-type or revertant hCMV, but not an IE1dl410-420 mutant virus, and this response results in restricted viral replication. We conclude that IE1 is sufficient and necessary to rewire upstream IL6-type to downstream IFNγ-like signaling, two pathways linked to opposing actions, resulting in repressed STAT3- and activated STAT1-responsive genes. These findings relate transcriptional repressor and activator functions of IE1 and suggest unexpected outcomes relevant to viral pathogenesis in response to cytokines or growth factors that signal through the IL6ST-JAK1-STAT3 axis in hCMV-infected cells. Our results also reveal that IE1, a protein considered to be a key activator of the hCMV productive cycle, has an unanticipated role in tempering viral replication.Publisher PDFPeer reviewe

    MÖSSBAUER ABSORPTION SPECTRA OF 119Sn IN THE SINGLE CRYSTALS OF (CH3)2Sn(NCS)2, (CH3)2SnCl2(C5H5NO)2, AND (CH3)3SnCn

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    Les spectres d'absorption Mössbauer de 119Sn dans des monocristaux de (CH3)2Sn(NCS)2, (CH3)2SnCl2(C5H5NO)2, et (CH3)3SnCn ont été mesurés à 110 K. Les analyses du rapport d'intensité du doublet quadrupolaire donnent les composants du tenseur de gradient de champ électrique (GCE).The Mössbauer absorption spectra of 119Sn in the single crystals of (CH3)2Sn(NCS)2, (CH3)2SnCl2(C5H5NO)2, and (CH3)3SnCN were measured at 110 K. The analysis of the intensity ratio of the quadrupole splitting doublet yields the parameters of the electric field gradient (EFG) tensor

    129I MÖSSBAUER STUDY OF CHARGE TRANSFER COMPLEXES OF IODINE IN THE FROZEN SOLUTION

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    On a étudié par effet Mössbauer de 129I les effets de transfert de charge de la triethylamine et de la pyridine dans la station gelée à 16° K de disulfure de carbone. Les spectres Mössbauer mettent en évidence les deux espèces chimiques de l'iode, correspondant au pontage et aux atomes des extrémités de chaîne. Le taux de transfert de charge a été trouvé égal à 0,14e- pour la triethylamine et à 0,12e- pour la pyridine.The Mössbauer effect of 129I was used to investigate the charge transfer complexes of triethylamine-iodine and pyridine-iodine in the carbon disulfide frozen solution at 16 K. The Mössbauer spectra of these complexes show the two chemical species of iodine, which correspond to the bridging and terminal iodines. From the Mössbauer parameters the degrees of the charge transfer were found to be 0.15e- for the triethylamine-iodine complex and 0.06e- for pyridine-iodine
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