L’expression des cyclo-oxygénases et des oxydes nitriques synthases avec les protéines adaptatrices TRAFs dans les cellules progénitrices endothéliales

L’interaction du CD40L plaquettaire avec le CD40 exprimé par les mono-lymphocytaires, dont les cellules progénitrices endothéliales (EPCs), médie l’hémostase. Deux sous-types d’EPCs induisent la réparation vasculaire : les early outgrowth cells (EOCs) et les endothelial colony forming cells (ECFCs). Les EOCs expriment des protéines adaptatrices s’associant aux récepteurs du facteur de nécrose tumorale (TRAFs) nécessaires à la signalisation du CD40. L’association des TRAFs au CD40 contribuerait à la fonction antiplaquettaire d’EOCs prétraitées au CD40L, via la libération de prostacycline (PGI2) ou d'oxyde nitrique (NO). Toutefois, la contribution des TRAFs des ECFCs dans la libération de PGI2 et de NO via la régulation des cyclo-oxygénases (COX) et des NO synthases (NOS) demeure inexplorée. Cette étude vise à comprendre le rôle des TRAFs, COX et NOS dans les ECFCs. Nous avons différencié des EPCs via la culture de cellules mononucléaires du sang périphérique (PBMCs) dans un milieu à croissance endothéliale (EGM-2) et révélé, par microscopie optique et confocale, le phénotype monocytaire de nos EOCs et de cellules endothéliales (ECs) de nos ECFCs, incluant leurs caractéristiques endothéliales par cytométrie en flux. L’expression constitutive de l’eNOS, l’iNOS, la COX-1 et faiblement la COX-2 dans nos ECFCs et ECs, des enzymes absentes de nos EOCs, a été décelée par Western Blot. Le profil d'expression des TRAFs dans nos EOCs, ECFCs, PBMCs et ECs a démontré la présence variée du CD40 et celle des TRAF1, 2, 3, 5 et 6, selon le type cellulaire. En conclusion, nous avons révélé la présence de TRAFs, COX et NOS, ainsi que leur expression différentielle dans les EOCs et ECFCs. Des études portant sur l’association des TRAFs au CD40 éclaireront sur les mécanismes intracellulaires impliqués dans la régulation de la synthèse de PGI2 et de NO et la fonction antiplaquettaire des EPCs.Platelets secrete CD40L whereas white blood cells such as endothelial progenitor cells (EPCs) express its cognate receptor CD40, the previous dyad allowing hemostasis. Recent evidences revealed the existence of two EPC subtypes implicated in vascular repair: early outgrowth cells (EOCs) and endothelial colony-forming cells (ECFCs). EOCs express adapter proteins, members of the TNF receptor-associated factors (TRAFs), necessary for CD40 signaling, the latter possibly involved in the anti-platelet function of sCD40L-treated EOCs, through prostacyclin (PGI2) and nitric oxide (NO) secretion. However, the TRAFs present in ECFCs which may act upstream of CD40 signaling to regulate the expression of cyclooxygenases (COX) and NO synthases (NOS) are still unexplored. This study aims to investigate the role of TRAFs, COX and NOS in ECFCs. We succeeded in differentiating EPCs by culturing peripheral blood mononuclear cells (PBMCs) in an endothelial growth medium (EGM-2), and showed by optical and confocal microscopy that EOCs display a monocyte-like phenotype whereas ECFCs have an endothelial cell (EC)-like phenotype, both EPC subtypes sharing endothelial features assessed by flow cytometry. Indeed, ECFCs, like ECs, constitutively express eNOS, iNOS, COX-1 and weakly COX-2; whereas EOCs do not constitutively express these NO and PGI2 producing enzymes, as shown by Western Blot. Comparing the expression profile of TRAFs in EOCs, ECFCs, PBMCs and ECs, we found that they all express CD40, TRAF1, 2, 3, 5 and 6. However, their levels of expression vary between the different cell types. Results generated from this project informed on the presence of TRAFs, COX and NOS in EOCs and ECFCs, where further studies on CD40 association with its identified TRAFs in each EPC subtype should shed lights on the downstream intracellular mechanisms involved in the regulation of COX and NOS expression in EOCs and ECFCs, and consequently their anti-platelet function

Ichthyofauna in the biological organization of a paralic system: the Aveiro Lagoon (Portugal) in 1987-1988 and 1999-2000

Cette étude concerne un écosystème paralique, la lagune d’Aveiro (Portugal). Elle vise à déterminer l’organisation des peuplements de poissons en fonction des caractéristiques et du fonctionnement de cet écosystème. L’ichtyofaune a été échantillonnée mensuellement en 10 stations d’août 1987 à juillet 1988 et de janvier 1999 à décembre 2000, avec une seine de plage traditionnelle. La répartition des peuplements de poissons est étudiée au moyen de descripteurs populationnels (richesses spécifique et familiale, densité, biomasse et indice de diversité) et d’analyses statistiques (groupements et ordination). La lagune d’Aveiro présente de fortes variations, dans l’espace et le temps, de ses paramètres physico- chimiques reflétant ainsi les variations climatiques annuelles. Si l’on considère la mobilité des poissons et la géomorphologie et l’hydrologie du système étudié, nous pouvions nous attendre à une forte homogénéité de la distribution des poissons. À l’inverse, une diminution de l’influence marine a pour conséquence une diminution des richesses spécifiques et familiales, de la densité et de la biomasse. Nous avons également observé une modification de composition de l’assemblage de poissons et la présence d’espèces dominantes caractéristiques des différents niveaux de confinement (taux de renouvellement des eaux marines en un point donné du système). Le peuplement de poissons présente une organisation semblable à la zonation biologique, indépendamment des paramètres physico-chimiques tels que la salinité, décrite par la macrofaune benthique et induite par le confinement. La comparaison des résultats avec des données obtenues douze ans plus tôt, montre que l’organisation générale de la lagune est demeurée inchangée, illustrant ainsi la stabilité des écosystèmes paraliques. De plus, des modifications du niveau de confinement dans les marges nord et sud, induites principalement par des changements locaux de l’hydrodynamisme, ont été constatées. Le déconfinement de la zone nord est la conséquence de l’entretien des canaux de navigation par dragage. À l’inverse, le confinement de la zone sud est l’évolution naturelle des bassins paraliques soumis souvent à une sédimentation élevée et rapide. Cette étude montre que l’organisation du peuplement de poissons valide le concept du confinement pour l’organisation biologique des milieux paraliques, et peut être employé pour expliquer les changements de ces écosystèmes.This study was performed in a paralic ecosystem, the Aveiro lagoon ecosystem (Portugal). It aims to determine the fish assemblage organisation according to its characteristics and functioning. The ichthyofauna was sampled monthly at 10 stations from August 1987 to July 1988 and from January 1999 to December 2000, with a traditional beach seine. The distribution of the fish assemblages was studied with populational descriptors (specific and family richness, density, biomass and diversity and equitability indices) and statistical analyses (clustering and ordination). The Aveiro lagoon presents strong space and time variations of its physicochemical parameters reflecting the annual climatic variations. Given the geomorphology and hydrology of the system studied, and fish mobility, we could expect a great homogeneity of the fish distribution. On the reverse, the decrease in marine influence resulted in the decrease in specific and family richness and density and biomass in most cases. It was also observed a modification of the composition of the fish assemblage, and the presence of dominant species characteristics to confinement levels (renewal rate of marine water in a given point of the system). The fish community presented an organization similar to the biological zonation independently of the physicochemical gradients, such as salinity, described by the benthic macrofauna and induced by the confinement. The comparison with data obtained 12 years earlier, shows that the general organization of the lagoon remained unchanged, which proves the stability of this paralic ecosystem. The main confinement modifications took place along the northern and southern margins. One could noticed one case of deconfinement phenomenon, and one case of confinement phenomenon, induced by local changes of hydrodynamism. The deconfinement of the northern zone was mainly due to the maintenance of navigation channels by dredging. On the contrary, the confinement phenomenon in the southern zone was due to the natural evolution of the paralic basin which suffered from high and fast sedimentation. Thus, this study showed, that the fish assemblage validates the confinement concept in the biological organization of paralic ecosystems in this lagoon and could be used to highlight temporal changes in these ecosystems

Prehrana jegulje Anguilla anguilla u laguni Mauguio (Sredozemno more, Francuska)

This study deals with temporal variations in eel Anguilla anguilla diet, sampled seasonally inthe Languedocian Mauguio lagoon (Gulf of Lion), from Autumn 1998 to Summer 1999. Eel mainlyfeeds on benthic organisms, primarily small Amphipoda, Crustacea (mainly Gammarus gr. locusta),Polychaeta, insect larvae (Chironomidae) and small fish. Based on variations in the eels feedingregime, seasonal influence is illustrated by decreased feeding activity in summer, which progressivelyincreases during the following seasons. The trophic quality available to eels in the Mauguiolagoon depends more on allochtonous inputs from the catchment area than on its own hydrodynamicson which water of marine origin has little influence due to its long distance from the sea.Variations observed during the four seasons illustrate the opportunist type feeding behaviour ofeels. They consume the most available benthic preys at a given moment without using a particularfeeding strategy like specialisation or generalisation. Eel adapts its diet according to the availableresources offered by the ecosystem. Because of this eel, as an amphihaline migrant species, can becharacterised as an obvious indirect bioindicator of the trophic capacity and very marked level ofconfinement in the brackish lagoon ecosystem of Mauguio.U ovom radu se raspravlja o vremenskim kolebanjima u prehrani jegulje Anguilla anguilla, koja je uzorkovana sezonski u laguni Mauguio pokrajine Languedoc u Lionskom zaljevu, od jeseni 1998. do ljeta 1999. Jegulja se hrani bentoskim pridnenim organizmima, i to pretežito manjim rakušcima (poglavito Gammarus gr. locusta), mnogočetinašima, larvama insekata (Chironomidae) i manjim ribama. Temeljem varijacija u prehrambenom režimu jegulje sezonski utjecaj pokazuje da hranidbena aktivnost opada u ljeto, dok progresivno raste u ostalim godišnjim dobima. Trofička kvaliteta dostupna jeguljama u laguni Mauguio ovisi više o alohtonom unosu iz slivnog područja nego o vlastitoj hidrodinamici na koju morska voda ima malo utjecaja zbog njenog dugog miješanja s morem. Zapažena kolebanja tijekom četiri godišnja doba ukazuju na oportunistički tip prehrambenog ponašanja jegulje. Ona se hrani najdostupnijim bentoskim organizmima u datom trenutku bez ikakve prehrambene strategije kao što je su to specijalizirana ili generalizirana prehrambena strategija. Jegulje prilagođavaju svoju prehranu prema dostupnoj hrani unutar ekosustava. Stoga se jegulja kao migracijska vrsta može biti okarakterizirana kao očiti indirektni bioindikator trofičkog kapaciteta i vrlo značajnog nivoa ograničenja u ekosustavu bočate lagune Mauguio

Relationship between ventilator-associated pneumonia and mortality in COVID-19 patients: a planned ancillary analysis of the coVAPid cohort

Background Patients with SARS-CoV-2 infection are at higher risk for ventilator-associated pneumonia (VAP). No study has evaluated the relationship between VAP and mortality in this population, or compared this relationship between SARS-CoV-2 patients and other populations. The main objective of our study was to determine the relationship between VAP and mortality in SARS-CoV-2 patients. Methods Planned ancillary analysis of a multicenter retrospective European cohort. VAP was diagnosed using clinical, radiological and quantitative microbiological criteria. Univariable and multivariable marginal Cox's regression models, with cause-specific hazard for duration of mechanical ventilation and ICU stay, were used to compare outcomes between study groups. Extubation, and ICU discharge alive were considered as events of interest, and mortality as competing event. Findings Of 1576 included patients, 568 were SARS-CoV-2 pneumonia, 482 influenza pneumonia, and 526 no evidence of viral infection at ICU admission. VAP was associated with significantly higher risk for 28-day mortality in SARS-CoV-2 group (adjusted HR 1.65 (95% CI 1.11-2.46), p = 0.013), but not in influenza (1.74 (0.99-3.06), p = 0.052), or no viral infection groups (1.13 (0.68-1.86), p = 0.63). VAP was associated with significantly longer duration of mechanical ventilation in the SARS-CoV-2 group, but not in the influenza or no viral infection groups. VAP was associated with significantly longer duration of ICU stay in the 3 study groups. No significant difference was found in heterogeneity of outcomes related to VAP between the 3 groups, suggesting that the impact of VAP on mortality was not different between study groups. Interpretation VAP was associated with significantly increased 28-day mortality rate in SARS-CoV-2 patients. However, SARS-CoV-2 pneumonia, as compared to influenza pneumonia or no viral infection, did not significantly modify the relationship between VAP and 28-day mortality

a planned ancillary analysis of the coVAPid cohort

Funding: This study was supported in part by a grant from the French government through the «Programme Investissement d’Avenir» (I-SITE ULNE) managed by the Agence Nationale de la Recherche (coVAPid project). The funders of the study had no role in the study design, data collection, analysis, or interpreta tion, writing of the report, or decision to submit for publication.BACKGROUND: Patients with SARS-CoV-2 infection are at higher risk for ventilator-associated pneumonia (VAP). No study has evaluated the relationship between VAP and mortality in this population, or compared this relationship between SARS-CoV-2 patients and other populations. The main objective of our study was to determine the relationship between VAP and mortality in SARS-CoV-2 patients. METHODS: Planned ancillary analysis of a multicenter retrospective European cohort. VAP was diagnosed using clinical, radiological and quantitative microbiological criteria. Univariable and multivariable marginal Cox's regression models, with cause-specific hazard for duration of mechanical ventilation and ICU stay, were used to compare outcomes between study groups. Extubation, and ICU discharge alive were considered as events of interest, and mortality as competing event. FINDINGS: Of 1576 included patients, 568 were SARS-CoV-2 pneumonia, 482 influenza pneumonia, and 526 no evidence of viral infection at ICU admission. VAP was associated with significantly higher risk for 28-day mortality in SARS-CoV-2 (adjusted HR 1.70 (95% CI 1.16-2.47), p = 0.006), and influenza groups (1.75 (1.03-3.02), p = 0.045), but not in the no viral infection group (1.07 (0.64-1.78), p = 0.79). VAP was associated with significantly longer duration of mechanical ventilation in the SARS-CoV-2 group, but not in the influenza or no viral infection groups. VAP was associated with significantly longer duration of ICU stay in the 3 study groups. No significant difference was found in heterogeneity of outcomes related to VAP between the 3 groups, suggesting that the impact of VAP on mortality was not different between study groups. INTERPRETATION: VAP was associated with significantly increased 28-day mortality rate in SARS-CoV-2 patients. However, SARS-CoV-2 pneumonia, as compared to influenza pneumonia or no viral infection, did not significantly modify the relationship between VAP and 28-day mortality. CLINICAL TRIAL REGISTRATION: The study was registered at ClinicalTrials.gov, number NCT04359693.publishersversionpublishe

Etude du système latéral des Gobiidae : comparaison de méthodes d'observation

International audienceEn prenant comme exemple le gobie à crête Lophogobius cyprinoides (Pallas, 1770), les éléments (canaux et pores et canaux sensoriels muqueux, et papilles sensorielles) composant le système latéral (SL) ont été observés selon plusieurs méthodes de préparation. Des échantillons ont été préparés soit pour observation en microscopie électronique à balayage (MEB), soit pour observation en microscopie photonique après immersion dans du liquide de fixation "Bouin Hollande" ou dans du formol à 4% en eau de mer avant coloration au KMnO4 (technique traditionnelle). Les résultats obtenus avec le MEB et le Bouin Hollande sont meilleurs qu'avec la méthode traditionnelle et présentent une plus grande reproductibilité. Bien que moins rapide et plus onéreuse, la méthode d'évaluation au MEB offre une finesse d'observation qui n'est pas obtenue au Bouin Hollande en raison de la limite du grandissement en microscopie optique. Si l'ultrastructure des papilles sensorielles ne peut être observable qu'au MEB, le SL des poissons Gobiidae peut être facilement étudié de manière approfondie avec les deux méthodologies proposées dans ce travail. Elles sont à préconiser car plus fiables que la technique traditionnelle consistant en une immersion dans une solution de permanganate de potassium et d'acide sulfurique. Celle-ci détériore partiellement les papilles sensorielles du SL rendant son analyse plus délicate

Evaluation of GC/MS-Based 13C-Positional Approaches for TMS Derivatives of Organic and Amino Acids and Application to Plant 13C-Labeled Experiments

International audienceAnalysis of plant metabolite 13C-enrichments with gas-chromatography mass spectrometry (GC/MS) has gained interest recently. By combining multiple fragments of a trimethylsilyl (TMS) derivative, 13C-positional enrichments can be calculated. However, this new approach may suffer from analytical biases depending on the fragments selected for calculation leading to significant errors in the final results. The goal of this study was to provide a framework for the validation of 13C-positional approaches and their application to plants based on some key metabolites (glycine, serine, glutamate, proline, α-alanine and malate). For this purpose, we used tailor-made 13C-PT standards, harboring known carbon isotopologue distributions and 13C-positional enrichments, to evaluate the reliability of GC-MS measurements and positional calculations. Overall, we showed that some mass fragments of proline_2TMS, glutamate_3TMS, malate_3TMS and α-alanine_2TMS had important biases for 13C measurements resulting in significant errors in the computational estimation of 13C-positional enrichments. Nevertheless, we validated a GC/MS-based 13C-positional approach for the following atomic positions: (i) C1 and C2 of glycine_3TMS, (ii) C1, C2 and C3 of serine_3TMS, and (iii) C1 of malate_3TMS and glutamate_3TMS. We successfully applied this approach to plant 13C-labeled experiments for investigating key metabolic fluxes of plant primary metabolism (photorespiration, tricarboxylic acid cycle and phosphoenolpyruvate carboxylase activity)

Systématique du Gobiidae Lophogobius cyprinoides (Pallas, 1770)

International audienceDiagnose : nombre de rayons des nageoires D1 : VI ; D2 : I+ 9 ; C : 21-22 ; A : I+ 8 ; P : 17-18 ; Pv : 10 ; nombres d'écailles sur la ligne latérale Éc : 27-28, de vertèbres V : 26. Il existe un dimorphisme sexuel des papilles urogénitales. Le système latéral a été observé en utilisant la microscopie électronique à balayage après fixation dans une solution de glutaraldéhyde à 2 % en eau de mer. Les canaux oculoscapulaires, préoperculaires, les pores muqueux, ainsi que les séries de neuromastes superficiels sont répertoriés et le nombre de neuromastes compté dans chacune. Les séquences codantes pour l'ARN ribosomique 18S sont identifiées