Défi MOREST - Mortalités estivales de l'huître creuse Crassostrea gigas - Caractérisation des facteurs de risques associés au mortalites estivales - Synthèse du thème I - Évaluation des risques dans les écosystèmes conchylicoles. (La Rochelle 14- 15 mars 2006)

L'objectif de ce thème est de préciser les relations entre Mortalités et Environnement, en déclinant cette relation à travers les "risques environnementaux" caractérisés depuis le début du programme MOREST. La température, les bassins versant etlou l'eau douce, la ressource trophique, le compartiment sédimentaire, autant de facteurs impliqués directement ou indirectement dans les processus de mortalités de Crassostrea gigas. Ces facteurs d'influence "externe" sont étudiés à différentes échelles d'espace ("nationale", "régionale", "sites") et de temps (annuelle, mensuelle, bimensuelle, journalière, horaire, infra horaire) en s'appuyant sur des données issues de bases institutionnelles (REMORA', REPHY~, METEO-FRANCE) et sur les résultats de terrain obtenus depuis le début du programme MOREST sur les 3 sites ateliers (Marennes Oléron, Rivière d'Auray, Baie des Veys

A compilation of silicon and thirty one trace elements measured in the natural river water reference material SLRS-4 (NRC-CNRC)

Le standard d'eau de rivière SLRS-4 (NRC-CNRC, National Research Council-Conseil National de Recherches Canada) est analysé régulièrement comme contrôle qualité par six laboratoires français étudiant les éléments majeurs et en traces dans les solutions naturelles. La plupart des mesures sont réalisées par ICP-MS (Inductively Coupled Plasma- Mass Spectrometry). Le silicium et 31 éléments en traces (terres rares, Ag, B, Br, Cs, Ga, Ge, Li, P, Pd, Rb, Se, Th, Ti, Tl, W, Y and Zr) ne sont pas certifiés par NRC-CNRC. Nous proposons des valeurs de compilation pour ces éléments ainsi que les incertitudes associées d'après les concentrations moyennes obtenues par chaque laboratoire

Table ronde 6 - Quelles sont les responsabilités de la société vis-à-vis des personnes atteintes de maladies rares ?

International audienc

Monitoring of erectile and urethral sphincter dysfunctions in a rat model mimicking radical prostatectomy damage.

International audienceIntroduction. Animal models of urinary incontinence and erectile dysfunction following radical prostatectomy (RP) are lacking. Aims. To develop an animal model of combined post-RP urethral sphincter and erectile dysfunctions, and noninvasive methods to assess erectile function (EF) and urinary sphincter function (USF) during prolonged follow-up. Methods. In the main experiments, 60 male Sprague Dawley rats were randomized to a sham operation (N = 30) or electrocautery of both sides of the striated urethral sphincter (N = 30). EF and USF were evaluated preoperatively and on postoperative days 7, 15, 30, 60, and 90. Sphincter and penile tissue samples were evaluated histologically on days 7 (N = 10) and 30 (N = 10) to detect apoptosis (TUNEL assays) and fibrosis (Trichrome Masson staining). Main Outcome Measures. To assess EF, we measured systemic and penile blood flow using penile laser Doppler and penile rigidity using a durometer before and after apomorphine injection. USF was assessed based on the retrograde leak point pressure (LPPr). Results. Apomorphine increased baseline Doppler flow by 180% (95% confidence interval, 156-202%) and penile hardness from 3.49 ± 0.5 to 7.16 ± 0.82 Shore A units but did not change systemic arterial flow. Mean LPPr was 76.8 ± 6.18 mm Hg at baseline and decreased by 50% after injury, with no response to apomorphine on day 7. EF and USF impairments persisted up to 90 days post injury. Histology showed penile apoptosis on day 7 and extensive urethral sphincter and penile fibrosis on day 30. Our data did not allow us to determine whether the impairment in erectile response to apomorphine preponderantly reflected arterial penile insufficiency or veno-occlusive dysfunction. Conclusion. Electrocautery of the striated urethral sphincter caused severe and lasting impairment of EF and USF that could be monitored repeatedly using minimally invasive methods. This new animal model may hold potential for developing new treatments designed to correct post-RP impairments. Khodari M, Souktani R, Le Coz O, Bedretdinova D, Figeac F, Acquistapace A, Lesault PF, Cognet J, Rodriguez AM, and Yiou R. Monitoring of erectile and urethral sphincter dysfunctions in a rat model mimicking radical prostatectomy damage. J Sex Med 2012;9:2827-2837

Human mesenchymal stem cells reprogram adult cardiomyocytes toward a progenitor-like state through partial cell fusion and mitochondria transfer: Cell fusion-mediated cardiomyocyte reprogramming.

International audienceBecause stem cells are often found to improve repair tissue including heart without evidence of engraftment or differentiation, mechanisms underlying wound healing are still elusive. Several studies have reported that stem cells can fuse with cardiomyocytes either by permanent or partial cell fusion processes. However, the respective physiological impact of these two processes remains unknown in part because of the lack of knowledge of the resulting hybrid cells. To further characterize cell fusion, we cocultured mouse fully differentiated cardiomyocytes with human multipotent adipose-derived stem (hMADS) cells as a model of adult stem cells. We found that heterologous cell fusion promoted cardiomyocyte reprogramming back to a progenitor-like state. The resulting hybrid cells expressed early cardiac commitment and proliferation markers such as GATA-4, myocyte enhancer factor 2C, Nkx2.5, and Ki67 and exhibited a mouse genotype. Interestingly, human bone marrow-derived stem cells shared similar reprogramming properties than hMADS cells but not human fibroblasts, which suggests that these features might be common to multipotent cells. Furthermore, cardiac hybrid cells were preferentially generated by partial rather than permanent cell fusion and that intercellular structures composed of f-actin and microtubule filaments were involved in the process. Finally, we showed that stem cell mitochondria were transferred into cardiomyocytes, persisted in hybrids and were required for somatic cell reprogramming. In conclusion, by providing new insights into previously reported cell fusion processes, our data might contribute to a better understanding of stem cell-mediated regenerative mechanisms and thus, the development of more efficient stem cell-based heart therapies. STEM CELLS 2011;29:812-824

A Compilation of Silicon and Thirty One Trace Elements Measured in the Natural River Water Reference Material SLRS-4 (NRC-CNRC)

International audienceThe natural river water certified reference material SLRS-4 (NRC-CNRC, National Research Council-Conseil National de Recherches Canada) has been routinely analysed for major and trace elements by six French laboratories. Most measurements were made using inductively coupled plasma-mass spectrometry. For silicon and thirty one trace elements (rare earth elements, Ag, B, Br, Cs, Ga, Ge, Li, P, Pd, Rb, Se, Th, Ti, Tl, W, Y and Zr), no certified values are assigned by NRC-CNRC. We propose some compilation values and related uncertainties according to the results obtained by the different laboratories.Le standard d’eau de rivière SLRS-4 (NRC-CNRC, National Research Council-Conseil National de Recherches Canada) est analysé régulièrementcomme contrôle qualité par six laboratoires français étudiant les éléments majeurs et en traces dans les solutions naturelles. La plupart des mesures sont réalisées par ICP-MS (Inductively Coupled Plasma- Mass Spectrometry). Le silicium et 31 éléments en traces (terres rares, Ag, B, Br, Cs, Ga, Ge, Li, P, Pd, Rb, Se, Th, Ti, Tl, W, Y and Zr) ne sont pas certifiés par NRC-CNRC. Nous proposons des valeurs de compilation pour ces éléments ainsi que les incertitudes associées d’après les concentrations moyennes obtenues par chaque laboratoire

Rilpivirine in HIV-1-positive women initiating pregnancy: to switch or not to switch?

International audienceBackgroundSafety data about rilpivirine use during pregnancy remain scarce, and rilpivirine plasma concentrations are reduced during second/third trimesters, with a potential risk of viral breakthroughs. Thus, French guidelines recommend switching to rilpivirine-free combinations (RFCs) during pregnancy.ObjectivesTo describe the characteristics of women initiating pregnancy while on rilpivirine and to compare the outcomes for virologically suppressed subjects continuing rilpivirine until delivery versus switching to an RFC.MethodsIn the ANRS-EPF French Perinatal cohort, we included women on rilpivirine at conception in 2010–18. Pregnancy outcomes were compared between patients continuing versus interrupting rilpivirine. In women with documented viral suppression (<50 copies/mL) before 14 weeks of gestation (WG) while on rilpivirine, we compared the probability of viral rebound (≥50 copies/mL) during pregnancy between subjects continuing rilpivirine versus those switching to RFC.ResultsAmong 247 women included, 88.7% had viral suppression at the beginning of pregnancy. Overall, 184 women (74.5%) switched to an RFC (mostly PI/ritonavir-based regimens) at a median gestational age of 8.0 WG. Plasma HIV-1 RNA nearest delivery was <50 copies/mL in 95.6% of women. Among 69 women with documented viral suppression before 14 WG, the risk of viral rebound was higher when switching to RFCs than when continuing rilpivirine (20.0% versus 0.0%, P = 0.046). Delivery outcomes were similar between groups (overall birth defects, 3.8/100 live births; pregnancy losses, 2.0%; preterm deliveries, 10.6%). No HIV transmission occurred.ConclusionsIn virologically suppressed women initiating pregnancy, continuing rilpivirine was associated with better virological outcome than changing regimen. We did not observe a higher risk of adverse pregnancy outcomes