Oocyte-somatic cells interactions, lessons from evolution

BACKGROUND: Despite the known importance of somatic cells for oocyte developmental competence acquisition, the overall mechanisms underlying the acquisition of full developmental competence are far from being understood, especially in non-mammalian species. The present work aimed at identifying key molecular signals from somatic origin that would be shared by vertebrates. RESULTS: Using a parallel transcriptomic analysis in 4 vertebrate species - a teleost fish, an amphibian, and two mammals - at similar key steps of developmental competence acquisition, we identified a large number of species-specific differentially expressed genes and a surprisingly high number of orthologous genes exhibiting similar expression profiles in the 3 tetrapods and in the 4 vertebrates. Among the evolutionary conserved players participating in developmental competence acquisition are genes involved in key processes such as cellular energy metabolism, cell-to-cell communications, and meiosis control. In addition, we report many novel molecular actors from somatic origin that have never been studied in the vertebrate ovary. Interestingly, a significant number of these new players actively participate in Drosophila oogenesis. CONCLUSIONS: Our study provides a comprehensive overview of evolutionary-conserved mechanisms from somatic origin participating in oocyte developmental competence acquisition in 4 vertebrates. Together our results indicate that despite major differences in ovarian follicular structure, some of the key players from somatic origin involved in oocyte developmental competence acquisition would be shared, not only by vertebrates, but also by metazoans. The conservation of these mechanisms during vertebrate evolution further emphasizes the important contribution of the somatic compartment to oocyte quality and paves the way for future investigations aiming at better understanding what makes a good egg

Impact of early enteral versus parenteral nutrition on mortality in patients requiring mechanical ventilation and catecholamines: study protocol for a randomized controlled trial (NUTRIREA-2)

BACKGROUND: Nutritional support is crucial to the management of patients receiving invasive mechanical ventilation (IMV) and the most commonly prescribed treatment in intensive care units (ICUs). International guidelines consistently indicate that enteral nutrition (EN) should be preferred over parenteral nutrition (PN) whenever possible and started as early as possible. However, no adequately designed study has evaluated whether a specific nutritional modality is associated with decreased mortality. The primary goal of this trial is to assess the hypothesis that early first-line EN, as compared to early first-line PN, decreases day 28 all-cause mortality in patients receiving IMV and vasoactive drugs for shock. METHODS/DESIGN: The NUTRIREA-2 study is a multicenter, open-label, parallel-group, randomized controlled trial comparing early PN versus early EN in critically ill patients requiring IMV for an expected duration of at least 48 hours, combined with vasoactive drugs, for shock. Patients will be allocated at random to first-line PN for at least 72 hours or to first-line EN. In both groups, nutritional support will be started within 24 hours after IMV initiation. Calorie targets will be 20 to 25 kcal/kg/day during the first week, then 25 to 30 kcal/kg/day thereafter. Patients receiving PN may be switched to EN after at least 72 hours in the event of shock resolution (no vasoactive drugs for 24 consecutive hours and arterial lactic acid level below 2 mmol/L). On day 7, all patients receiving PN and having no contraindications to EN will be switched to EN. In both groups, supplemental PN may be added to EN after day 7 in patients with persistent intolerance to EN and inadequate calorie intake. We plan to recruit 2,854 patients at 44 participating ICUs. DISCUSSION: The NUTRIREA-2 study is the first large randomized controlled trial designed to assess the hypothesis that early EN improves survival compared to early PN in ICU patients. Enrollment started on 22 March 2013 and is expected to end in November 2015. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT01802099 (registered 27 February 2013)

Évaluation immédiate et à long terme de la Formation des Référents aux Techniques d'Intubation Difficile (FRTID) (étude prospective de 2008 à 2011)

La formation des référents aux techniques d'intubation difficile (FRTID) est une formation multidisciplinaire biannuelle théorique et pratique sur la prise en charge difficile des voies aériennes supérieures. Elle contribue à la diffusion des recommandations de la conférence d'experts français et crée un véritable statut de référent ID. L'évaluation réalisée à distance de la formation montre des répercussions réelles sur l'organisation des services. L'enseignement dispensé entraine un souhait de modification de pratiques médicales, une amélioration des connaissances théoriques, des compétences techniques et comportementales. Les ateliers pratiques et la simulation médicale possèdent un impact pédagogique significatif et complémentaire. Ce mode d'enseignement pédagogique est plébiscité pour la formation médicale et contribue au développement professionnel continu.NANTES-BU Médecine pharmacie (441092101) / SudocSudocFranceF

Mesoscale pore structure of a high‐performance concrete by coupling focused ion beam/scanning electron microscopy and small angle X‐ray scattering

International audienceThis contribution couples (a) Small angle X‐ray scattering (SAXS) experiments of a high‐performance concrete (HPC) at the millimetric scale, and (b) Focused ion beam/scanning electron microscopy (FIB/SEM) of the cement paste of the HPC, with 10‐20 nm voxel size. The aim is to improve the understanding of the 3D pore network of the HPC at the mesoscale (tens of nm), which is relevant for fluid transport. The mature HPC is an industrial concrete, based on pure Portland CEMI cement, and planned for use as structural elements for deep underground nuclear waste storage. Small angle X‐ray scattering patterns are computed from the 3D pore images given by FIB/SEM (volumes of 61‐118 μm3). They are positively correlated with SAXS measurements (volumes of 5 mm3). Aside from correlations with FIB/SEM data, experimental SAXS allows to investigate a wider range of effects on the pore structure. These are mainly the HPC drying state, the presence of aggregates (by analyzing data on cement paste alone), and the use of Poly Methyl MethAcrylate resin impregnation

Oocyte-somatic cells interactions, lessons from evolution

Abstract Background Despite the known importance of somatic cells for oocyte developmental competence acquisition, the overall mechanisms underlying the acquisition of full developmental competence are far from being understood, especially in non-mammalian species. The present work aimed at identifying key molecular signals from somatic origin that would be shared by vertebrates. Results Using a parallel transcriptomic analysis in 4 vertebrate species - a teleost fish, an amphibian, and two mammals - at similar key steps of developmental competence acquisition, we identified a large number of species-specific differentially expressed genes and a surprisingly high number of orthologous genes exhibiting similar expression profiles in the 3 tetrapods and in the 4 vertebrates. Among the evolutionary conserved players participating in developmental competence acquisition are genes involved in key processes such as cellular energy metabolism, cell-to-cell communications, and meiosis control. In addition, we report many novel molecular actors from somatic origin that have never been studied in the vertebrate ovary. Interestingly, a significant number of these new players actively participate in Drosophila oogenesis. Conclusions Our study provides a comprehensive overview of evolutionary-conserved mechanisms from somatic origin participating in oocyte developmental competence acquisition in 4 vertebrates. Together our results indicate that despite major differences in ovarian follicular structure, some of the key players from somatic origin involved in oocyte developmental competence acquisition would be shared, not only by vertebrates, but also by metazoans. The conservation of these mechanisms during vertebrate evolution further emphasizes the important contribution of the somatic compartment to oocyte quality and paves the way for future investigations aiming at better understanding what makes a good egg.</p

Speckle tracking analysis allows sensitive detection of stress cardiomyopathy in severe aneurysmal subarachnoid hemorrhage patients

International audiencePURPOSE: Stress cardiomyopathy is a common life-threatening complication after aneurysmal subarachnoid hemorrhage (SAH). We hypothesized that left ventricular (LV) longitudinal strain alterations assessed with speckle tracking could identify early systolic function impairment. METHODS: This was an observational single-center prospective pilot controlled study conducted in a neuro-intensive care unit. Forty-six patients with severe SAH with a World Federation of Neurological Surgeons grade (WFNS) ≥III were included. Transthoracic echocardiography (TTE) was performed on day 1, day 3, and day 7 after the patient's admission. A cardiologist blinded to the patient's management analyzed the LV global longitudinal strain (GLS). The control group comprised normal subjects matched according to gender and age. RESULTS: On day 1 median (25th-75th percentile) GLS was clearly impaired in SAH patients compared to controls [-16.7 (-18.7/-13.7) % versus -20 (-22/-19) %, p \textless 0.0001], whereas LVEF was preserved [65 (59-70) %]. GLS was severely impaired in patients with a WFNS score of V versus III-IV [-15.6 (-16.9/-12.3) % versus -17.8 (-20.6/-15.8) %, p = 0.008]. Seventeen (37 %) patients had a severe GLS alteration (\textgreater-16 %). In these patients, GLS improved from day 1 [-12.4 (-14.8/-10.9) %] to last evaluation [-16.2 (-19/-14.6) %, p = 0.0007] in agreement with the natural evolution of stress cardiomyopathy. CONCLUSIONS: On the basis of LV GLS assessment, we demonstrated for the first time that myocardial alteration compatible with a stress cardiomyopathy is detectable in up to 37 % of patients with severe SAH while LVEF is preserved. GLS could be used for sensitive detection of stress cardiomyopathy. This is critical because cardiac impairment remains a major cause of morbidity and mortality after SA