Incidence and prognosis of sustained arrhythmias in critically III patients,”

Rationale: Sustained arrhythmias are common in postoperative and cardiac intensive care units (ICUs), but their incidence and prognosis in general ICUs have never been reported. Objectives: To estimate the incidence and prognosis of sustained arrhythmias in a general ICU population. Methods: Prospective, multicenter, 1-month inception cohort study. Measurements and Main Results: A total of 1,341 patients were included: 12% (163/1,341) had sustained arrhythmias, including 8% (113/1,341) and 2% (30/1,341) with supraventricular and ventricular arrhythmias, respectively, and 2% (30/1,341) with conduction abnormalities. In-hospital death rates were 17% (205/1,178) in patients without arrhythmia and 29% (33/113

Fonctions de la voie de signalisation Nodal au cours du développement embryonnaire de l'oursin Paracentrotus lividus

La genèse d un l organisme passe dans un premier temps par l établissement d un plan corporel organisé selon des axes embryonnaires. La voie de signalisation du TGF-beta Nodal joue un rôle crucial au cours de l établissement des axes de polarité des vertébrés. Les facteurs Nodal sont impliqués dans de nombreux processus de développement, comme lors de la formation du centre organisateur de Spemann, de l induction des feuillets endodermique et mésodermique ainsi que de la régionalisation de l embryon selon les axes antéro-postérieur et gauche-droite. Au cours de ma thèse, j ai analysé la fonction de la voie de signalisation Nodal au cours du développement embryonnaire de l oursin, un organisme Deutérostomien non-chordé. J ai pu montrer que Nodal joue un rôle central au cours de la spécification des axes embryonnaires. Dans un premier temps, Nodal intervient lors de la régionalisation des feuillets embryonnaires : ectoderme, endoderme et mésoderme, le long de l axe oral-aboral (dorso-ventral). Dans un deuxième temps, la cassette de gènes nodal/lefty/pitx2 régule l établissement des asymétries gauche-droite de l embryon d oursin. L ensemble de ces résultats suggère un rôle conservé de la voie de signalisation Nodal au cours de l établissement des axes embryonnaires dorso-ventral et gauche-droite des Deutérostomiens.NICE-BU Sciences (060882101) / SudocSudocFranceF

NiPTUNE: an automated pipeline for noninvasive prenatal testing in an accurate, integrative and flexible framework

International audienceAbstract Noninvasive prenatal testing (NIPT) consists of determining fetal aneuploidies by quantifying copy number alteration from the sequencing of cell-free DNA (cfDNA) from maternal blood. Due to the presence of cfDNA of fetal origin in maternal blood, in silico approaches have been developed to accurately predict fetal aneuploidies. Although NIPT is becoming a new standard in prenatal screening of chromosomal abnormalities, there are no integrated pipelines available to allow rapid, accurate and standardized data analysis in any clinical setting. Several tools have been developed, however often optimized only for research purposes or requiring enormous amount of retrospective data, making hard their implementation in a clinical context. Furthermore, no guidelines have been provided on how to accomplish each step of the data analysis to achieve reliable results. Finally, there is no integrated pipeline to perform all steps of NIPT analysis. To address these needs, we tested several tools for performing NIPT data analysis. We provide extensive benchmark of tools performances but also guidelines for running them. We selected the best performing tools that we benchmarked and gathered them in a computational pipeline. NiPTUNE is an open source python package that includes methods for fetal fraction estimation, a novel method for accurate gender prediction, a principal component analysis based strategy for quality control and fetal aneuploidies prediction. NiPTUNE is constituted by seven modules allowing the user to run the entire pipeline or each module independently. Using two cohorts composed by 1439 samples with 31 confirmed aneuploidies, we demonstrated that NiPTUNE is a valuable resource for NIPT analysis

FGF signals guide migration of mesenchymal cells, control skeletal morphogenesis and regulate gastrulation during sea urchin development

International audienceThe sea urchin embryo is emerging as an attractive model to study morphogenetic processes such as directed migration of mesenchyme cells and cell sheet invagination, but surprisingly, few of the genes regulating these processes have yet been characterized. We present evidence that FGFA, the first FGF family member characterized in the sea urchin, regulates directed migration of mesenchyme cells, morphogenesis of the skeleton and gastrulation during early development. We found that at blastula stages, FGFA and a novel putative FGF receptor are expressed in a pattern that prefigures morphogenesis of the skeletogenic mesoderm and that suggests that FGFA is one of the elusive signals that guide migration of primary mesenchyme cells (PMCs). We first show that fgfA expression is correlated with abnormal migration and patterning of the PMCs following treatments that perturb specification of the ectoderm along the oral-aboral and animal-vegetal axes. Specification of the ectoderm initiated by Nodal is required to restrict fgfA to the lateral ectoderm, and in the absence of Nodal, fgfA is expressed ectopically throughout most of the ectoderm. Inhibition of either FGFA, FGFR1 or FGFR2 function severely affects morphogenesis of the skeleton. Furthermore, inhibition of FGFA and FGFR1 signaling dramatically delays invagination of the archenteron, prevents regionalization of the gut and abrogates formation of the stomodeum. We identified several genes acting downstream of fgfA in these processes, including the transcription factors pea3 and pax2/5/8 and the signaling molecule sprouty in the lateral ectoderm and SM30 and SM50 in the primary mesenchyme cells. This study identifies the FGF signaling pathway as an essential regulator of gastrulation and directed cell migration in the sea urchin embryo and as a key player in the gene regulatory network directing morphogenesis of the skeleton

Reciprocal Signaling between the Ectoderm and a Mesendodermal Left-Right Organizer Directs Left-Right Determination in the Sea Urchin Embryo

<div><p>During echinoderm development, expression of <em>nodal</em> on the right side plays a crucial role in positioning of the rudiment on the left side, but the mechanisms that restrict <em>nodal</em> expression to the right side are not known. Here we show that establishment of left-right asymmetry in the sea urchin embryo relies on reciprocal signaling between the ectoderm and a left-right organizer located in the endomesoderm. FGF/ERK and BMP2/4 signaling are required to initiate <em>nodal</em> expression in this organizer, while Delta/Notch signaling is required to suppress formation of this organizer on the left side of the archenteron. Furthermore, we report that the H⁺/K⁺-ATPase is critically required in the Notch signaling pathway upstream of the S3 cleavage of Notch. Our results identify several novel players and key early steps responsible for initiation, restriction, and propagation of left-right asymmetry during embryogenesis of a non-chordate deuterostome and uncover a functional link between the H⁺/K⁺-ATPase and the Notch signaling pathway.</p> </div

Establishment of left-right asymmetry in echinoderms.

<p>Left-right asymmetry in echinoderms is characterized by the asymmetric positioning of the imaginal rudiment on the left side of the bilateral pluteus larva. The adult emerges from this imaginal rudiment through metamorphosis. Formation of the rudiment is intimately linked to development of two mesodermal derivatives, the coelomic pouches, that form from an unpaired coelomic sac that budds off from the tip of the archenteron. The coelomic pouches are bilateral structures, but only the coelomic pouch located on the left side of the larva proliferates and differentiates to form the rudiment. Precursors of the coelomic pouches have a double origin. Part of these precursors derives from the small micromeres that form by asymmetric division of the large micromeres at 5th cleavage. These cells are thought to contribute to the germ line. Another population of coelomic pouch precursors derives from the non-skeletogenic mesoderm that is induced during blastula stages by Delta signals emanating from the skeletogenic mesenchymal cell precursors.</p

Establishment of left-right asymmetry requires reciprocal Nodal signaling between the ectoderm and endomesoderm.

<p>A,B ectodermal Nodal signals are required for <i>nodal</i> expression in the endomesoderm. A, Experimental design. The four animal blastomeres of a 8-cell stage embryo were injected with a <i>nodal</i> morpholino and <i>nodal</i> expression was analyzed at the gastrula stage. B, DIC and Fluorescent images of injected larvae and whole mount in situ hybridization of injected embryos with the <i>nodal</i> probe. Blocking <i>nodal</i> mRNA translation in the ectoderm abolishes <i>nodal</i> expression in the endomesoderm at gastrula stage and radializes the embryos. C,D, <i>nodal</i> signaling in the endomesoderm is required for establishment of left-right asymmetry in the ectoderm. C, Experimental design. The vegetal half (four blastomeres) of embryos at the eight-cell stage were injected with the <i>alk4/5/7</i> morpholino. D, DIC and Fluorescent images of injected larvae and whole mount in situ hybridization of embryos with the <i>nodal</i> probe. <i>nodal</i> is expressed on the right side of the ectoderm in control embryos but in 9 out of 19 injected embryos, <i>nodal</i> expression is detected on the left side. <i>pitx2</i> is expressed on the right side of the endomesoderm in control embryos but in 5 out of 6 <i>alk4/5/7</i> morpholino injected embryos, <i>pitx2</i> expression is lost. E,F, Mosaic analysis using chimeric embryos produced by microsurgery. E, Experimental design. The vegetal half of a <i>nodal</i> morphant (green) was combined with a control animal half (grey). F, Fluorescent and DIC images of a chimeric larvae and whole mount in situ hybridization of chimeric embryos with a <i>nodal</i> probe. <i>nodal</i> is expressed on the right side of the ectoderm in control embryos but in 5 out of 12 chimeric embryos, <i>nodal</i> expression is detected on the left side. V, ventral; D, dorsal; LV, lateral view; AV, animal pole view; L, left; R, right; An, animal pole; Veg, vegetal pole.</p

Expression of <i>nodal</i> in the endomesoderm following inhibition of Nodal signaling in the ectoderm.

<p>Expression of <i>nodal</i> in the endomesoderm following inhibition of Nodal signaling in the ectoderm.</p

Model for establishment of left-right asymmetry by reciprocal signaling between the ectoderm and the endomesoderm.

<p>A, At midgastrula stage, <i>nodal</i> is expressed asymmetrically in endodermal cells on the right side under the influence of both positive (FGF and BMP signaling) and negative (signal X) inputs. At this stage, <i>nodal</i> is also expressed symmetrically in the ventral ectoderm. In contrast, <i>univin</i> is expressed more laterally in the presumptive ciliary band ectoderm and throughout the endoderm. As a consequence, the<i> nodal</i> and <i>univin</i> territories only partially overlap in the archenteron and in two ectodermal regions flanking the presumptive stomodeum (purple color). At this stage, while expression of <i>nodal</i> in the ventral ectoderm vanishes, asymmetrical Nodal+Univin signaling on the right side of the archenteron induces <i>nodal</i> expression in the lateral right ectoderm that expresses <i>univin</i> creating a novel Nodal+Univin expressing signaling center on the right side. The reaction-diffusion mechanism between Nodal and Lefty stabilizes <i>nodal</i> expression on the right side and prevents its expansion to the rest of the embryo. B, Summary diagrams of the experiments. Both the loss of <i>nodal</i> expression in the endoderm caused by inhibition of the FGF or BMP pathways or the bilateralisation of <i>nodal</i> expression in the endoderm caused by inhibition of Notch signaling, randomize <i>nodal</i> expression in the ectoderm at pluteus stage. In the endoderm, FGF/ERK positively regulates <i>nodal</i> expression on the right side while unidentified signals coming from the mesoderm induced by Delta/Notch signaling negatively regulate nodal expression on the left side of the archenteron. The window during which SU5402 and UO126 are effective at perturbing left-right asymmetry extends from fertilization to mesenchyme blastula/gastrula stage (green shading). H⁺/K⁺-ATPase acts on Delta/Notch signaling to regulate left-right asymmetry. The window during which DAPT (red shading) and omeprazole (blue shading) are effective on left-right asymmetry extends from egg up to the early blastula stage. Inhibition of <i>Nodal</i> or BMP signaling in the endomesoderm randomizes <i>nodal</i> expression in ectoderm. Injection of nodal mRNA alone fails to rescue left-right asymmetry and <i>pitx2</i> expression in embryos previously injected with a <i>nodal</i> morpholino but coinjection of <i>nodal+univin</i> mRNAs efficiently rescues <i>pitx2</i> expression in the coelomic pouch and ciliary band. In most of these embryos, <i>pitx2</i> is expressed more strongly on the right side. An, animal pole; Veg, vegetal pole.</p

Both inhibition of Notch signaling and inhibition of the H^+/K⁺-ATPase cause bilateral expression of <i>nodal</i> in the endomesoderm and randomize <i>nodal</i> expression in the ectoderm.

<p>A, <i>nodal</i> expression in control embryos and in embryos treated with DAPT or omeprazole starting after fertilization or injected with a morpholino oligonucleotide against <i>Delta</i>. Black arrowheads show an ectopic expression of <i>nodal</i> on the left side. The percentages indicate the proportion of embryos showing the same sidedness of <i>nodal</i> expression as that showed in the panel. B, At pluteus stage, <i>nodal</i> and <i>univin</i> expression in DAPT-treated embryos or in Delta-morpholino injected embryos is randomized. C, The expression of <i>pitx2</i>, <i>sox9</i> and <i>foxF</i> in the coelomic pouch precursors as well as the expression of <i>tropomyosin</i> in the muscle cell precursors is strongly reduced or absent in DAPT-treated embryos. D, Time course of DAPT treatments. Embryos were treated with DAPT starting at different stages and <i>nodal</i> expression was scored at pluteus stages. DAPT treatments perturb left-right asymmetry only when performed before hatching. VEB, very early blastula; EB, early blastula; SB, swimming blastula; MB, mesenchyme blastula. E, The window during which DAPT treatments interfere with left-right asymmetry coincides with the period during which non skeletogenic mesoderm precursors are induced by Delta/Notch signaling. AV, Animal views; DV, Dorsal views; L, Left; R, Right.</p