In vitro modulation of reactive oxygen and nitrogen intermediate (ROI/RNI) production in Crassostrea gigas hemocytes

International audienceBivalve hemocyte competence has been measured by quantifying functional characteristics, including reactive oxygen intermediate (ROI) production after activation with zymosan or phorbol myristate acetate (PMA). However, untreated oyster hemocytes also produce ROI and RNI (reactive nitrogen intermediates) after bleeding even if not stimulated by zymosan or PMA. Extensive investigation of this parameter by flow cytometry showed that, in vitro, ROI/RNI production by untreated hemocytes maintained in seawater appeared to be independent of both bacterial burden in the serum and non-self particle phagocytosis. ROI/ RNI production in granulocytes was higher than in hyalinocytes and could be intensified when activated by zymosan but not by PMA. Both cell types used NADPH-oxidase- and NO-synthase-like pathways to produce these molecules; the NO-synthase pathway seemed relatively more dominant in hyalinocytes and NADPH-oxidase appeared more effective in granulocytes. These results provide new insights for interpreting the modulation of ROI/RNI production by untreated hemocytes shown by other studies, relative to environmental conditions or physiological status of the oysters

Analyse et comparaison des niveaux de contamination en Polychlorobiphényles et pesticides organochlorés dans les foies de juvéniles de soles provenant de nourriceries du Golfe de Gascogne, de la Baie de Seine et de la Somme

Ce rapport de stage (2 mois et demi) traite du dosage de contaminants organiques, les Polychlorobiphényles (PCB) et les pesticides organochlorés chez les juvéniles de soles, dans différentes zones côtières de nourriceries sur le littoral français en Manche Est et dans le Golfe de Gascogne. Ces composés, hydrophobes, persistants et potentiellement bioaccumulables, se trouvent concentrés dans les tissus des poissons et en particulier dans le foie, riche en lipides. Les 16 congénères de PCB et les pesticides organochlorés sont dosés selon un protocole comprenant trois étapes : l'extraction, la purification par chromatographie d'adsorption pour séparer les composés, puis la quantification par chromatographie en phase gazeuse munie d'un détecteur à capture d'électrons (GC-ECD). La comparaison des niveaux de contamination des différentes zones étudiées révèlè la forte contamination de la Baie de Seine par rapport au Golfe de Gascogne. La bioaccumulation des PCB chez les juvéniles de groupe 0, 1 et 2 a été mise en évidence pour les zones Pertuis Breton et Baie de Vilaine, ainsi que la métabolisation du DDT en fonction de l'âge. Les données du Réseau National d'Observation (RNO) sur la contamination organique iles mollusques ont permis de souligner la variabilité inter-espèces des niveaux de contamination et donc la nécessité d'effectuer des dosages de contaminants chez les poissons

Characterisation of physiological and immunological differences between Pacific oysters (Crassostrea gigas) genetically selected for high or low survival to summer mortalities and fed different rations under controlled conditions

International audienceWithin the framework of a national scientific program named "MORtalités ESTivales de l'huître creuse Crassostrea gigas" (MOREST), a family-based experiment was developed to study the genetic basis of resistance to summer mortality in the Pacific oyster, Crassostrea gigas. As part of the MOREST project, the second generation of three resistant families and two susceptible families were chosen and pooled into two respective groups: "R" and "S". These two groups of oysters were conditioned for 6 months on two food levels (4% and 12% of oyster soft-tissue dry weight in algal dry weight per day) with a temperature gradient that mimicked the Marennes-Oléron natural cycle during the oyster reproductive period. Oyster mortality remained low for the first two months, but then rapidly increased in July when seawater temperature reached 19 °C and above. Mortality was higher in "S" oysters than in "R" oysters, and also higher in oysters fed the 12% diet than those fed 4%, resulting in a decreasing, relative order in cumulative mortality as follows; 12% "S" > 12% "R" > 4% "S" > 4% "R". Although the observed mortality rates were lower than those previously observed in the field, the mortality differential between "R" and "S" oysters was similar. Gonadal development, estimated by tissue lipid content, followed a relative order yielding a direct, positive relationship between reproductive effort and mortality as we reported precedently by quantitative histology. Regarding hemocyte parameters, one of the most striking observations was that reactive oxygen species (ROS) production was significantly higher in "S" oysters than in "R" oysters in May and June, regardless of food level. The absence of known environmental stress under these experimental conditions suggests that the ROS increase in "S" oyster could be related to their higher reproductive activity. Finally, a higher increase in hyalinocyte counts was observed for"S" oysters, compared to "R" oysters, in July, just before mortality. Taken together, our results suggest an association of genetically based resistance to summer mortality, reproductive strategy and hemocyte parameters

Prise en charge de première intention du couple infertile : mise à jour des RPC 2010 du CNGOF

Objective: To update the 2010 CNGOF clinical practice guidelines for the first-line management of infertile couples.Materials and methods: Five major themes (first-line assessment of the infertile woman, first-line assessment of the infertile man, prevention of exposure to environmental factors, initial management using ovulation induction regimens, first-line reproductive surgery) were identified, enabling 28 questions to be formulated using the Patients, Intervention, Comparison, Outcome (PICO) format. Each question was addressed by a working group that had carried out a systematic review of the literature since 2010, and followed the Grading of Recommendations Assessment, Development and Evaluation (GRADE®) methodology to assess the quality of the scientific data on which the recommendations were based. These recommendations were then validated during a national review by 40 national experts.Results: The fertility work-up is recommended to be prescribed according to the woman's age: after one year of infertility before the age of 35 and after 6months after the age of 35. A couple's initial infertility work-up includes a single 3D ultrasound scan with antral follicle count, assessment of tubal permeability by hysterography or HyFOSy, anti-Mullerian hormone assay prior to assisted reproduction, and vaginal swabbing for vaginosis. If the 3D ultrasound is normal, hysterosonography and diagnostic hysteroscopy are not recommended as first-line procedures. Chlamydia trachomatis serology does not have the necessary performance to predict tubal patency. Post-coital testing is no longer recommended. In men, spermogram, spermocytogram and spermoculture are recommended as first-line tests. If the spermogram is normal, it is not recommended to check the spermogram. If the spermogram is abnormal, an examination by an andrologist, an ultrasound scan of the testicles and hormonal test are recommended. Based on the data in the literature, we are unable to recommend a BMI threshold for women that would contraindicate medical management of infertility. A well-balanced Mediterranean-style diet, physical activity and the cessation of smoking and cannabis are recommended for infertile couples. For fertility concern, it is recommended to limit alcohol consumption to less than 5 glasses a week. If the infertility work-up reveals no abnormalities, ovulation induction is not recommended for normo-ovulatory women. If intrauterine insemination is indicated based on an abnormal infertility work-up, gonadotropin stimulation and ovulation monitoring are recommended to avoid multiple pregnancies. If the infertility work-up reveals no abnormality, laparoscopy is probably recommended before the age of 30 to increase natural pregnancy rates. In the case of hydrosalpinx, surgical management is recommended prior to ART, with either salpingotomy or salpingectomy depending on the tubal score. It is recommended to operate on polyps>10mm, myomas 0, 1, 2 and synechiae prior to ART. The data in the literature do not allow us to systematically recommend asymptomatic uterine septa and isthmoceles as first-line surgery.Conclusion: Based on strong agreement between experts, we have been able to formulate updated recommendations in 28 areas concerning the initial management of infertile couples