Association between genetic obesity susceptibility and mother-reported eating behaviour in children up to 5 years.

BACKGROUND: Many genetic polymorphisms identified by genome-wide association studies for adult body mass index (BMI) have been suggested to regulate food intake. OBJECTIVE: The objective was to study the associations between a genetic obesity risk score, appetitive traits, and growth of children up to age 5 years, with a longitudinal design. METHODS: In 1142 children from the Etude des Déterminants pre et post natals de la santé de l'ENfant (EDEN) birth cohort, a combined obesity risk-allele score (BMI genetic risk score [GRS]) was related to appetitive traits (energy intake up to 12 mo, a single item on appetite from 4 mo to 3 y, a validated appetite score at 5 y) using Poisson regressions with robust standard errors. The potential mediation of appetitive traits on the association between BMI-GRS and growth was assessed by the Sobel test. RESULTS: Children with a high BMI-GRS were more likely to have high energy intake at 1 year and high appetite at 2 and 5 years. High energy intake in infancy and high appetite from 1 year were related to higher subsequent BMI. High 2-year appetite seemed to partially mediate the associations between BMI-GRS and BMI from 2 to 5 years (all P ≤ 0.05). CONCLUSIONS: Genetic susceptibility to childhood obesity seems to be partially explained by appetitive traits in infancy, followed by an early childhood rise in BMI.The EDEN study is supported by Fondation pour la Recherche Médicale (FRM), French Ministry of Research: Federative Research Institutes and Cohort Program, INSERM Human Nutrition National Research Program, and Diabetes National Research Program (through a collaboration with the French Association of Diabetic Patients [AFD]), French Ministry of Health, French Agency for Environment Security (AFSSET), French National Institute for Population Health Surveillance (InVS), Paris‐Sud University, French National Institute for Health Education (INPES), Nestlé, Mutuelle Générale de l'Education Nationale (MGEN), French‐speaking Association for the Study of Diabetes and Metabolism (ALFEDIAM), National Agency for Research (ANR non‐thematic programme), and National Institute for Research in Public Health (IRESP: TGIR 2008 cohort in health programme). The genotyping was funded by a Collaborative Research Grant from the European Society for Paediatric Endocrinology. K.K.O. is supported by the Medical Research Council (unit program: MC_UU_12015/2)

Induction de la cardioprotection par le diazoxide (études en temps réel sur un modèle cellulaire)

Une protection contre les lésions dues à une ischmie-reperfusion peut être induite par le diazoxide, un ouvreur de canaux potassiques ATP-dépendants (Katp). Le diazoxide est aussi connu pour inhiber la succinate déshydrogénase (SDH), enzyme de la chaîne respiratoire et du cycle de Krebs. Pour mieux comprendre les mécanismes en jeu, nous avons caractérisé la lignée cellulaire d'origine cardiaque HL-1-NB, adaptée à l'utilisation de techniques optiques, pour suivre en temps réel plusieurs paramètres cellulaires. Sur ce modèle nous avons montré que le diazoxide n'induit pas l'ouverture des canaux KATP, ni sarcolemmaux, ni mitochondriaux, dans des conditions qui induisent pourtant une protection. Nos résultats sont en faveur d'un rôle clé de l'inhibition de la SDH dans l'induction de la protection. Ils suggèrent par ailleurs que le diazoxide pourrait avoir, par une action sur les canaux KATP sarcolemmaux, indépendamment de leur ouverture, un effet métabolique compartimentéLYON1-BU.Sciences (692662101) / SudocSudocFranceF

Iron nanoparticles increase 7-ketocholesterol-induced cell death, inflammation, and oxidation on murine cardiac HL1-NB cells

Edmond Kahn1, Mauhamad Baarine2, Sophie Pelloux3, Jean-Marc Riedinger4, Frédérique Frouin1, Yves Tourneur3, Gérard Lizard21INSE RM U678/UMR – S UPMC, IFR 14, CH U Pitié-Salpêtrière, 75634 Paris Cedex 13, France; 2Centre de Recherche INSE RM U866, Equipe Biochimie Métabolique et Nutritionnelle – Université de Bourgogne, Faculté des Sciences Gabriel, 6 Bd Gabriel, 21000 Dijon, France; 3Centre Commun de Quantimétrie, Université Lyon 1; Université de Lyon, Lyon, France; 4Département de Biologie et de Pathologie des Tumeurs, Centre Georges François-Leclerc, 21000 Dijon, FranceObjective: To evaluate the cytotoxicity of iron nanoparticles on cardiac cells and to determine whether they can modulate the biological activity of 7-ketocholesterol (7KC) involved in the development of cardiovascular diseases. Nanoparticles of iron labeled with Texas Red are introduced in cultures of nonbeating mouse cardiac cells (HL1-NB) with or without 7-ketocholesterol 7KC, and their ability to induce cell death, pro-inflammatory and oxidative effects are analyzed simultaneously.Study design: Flow cytometry (FCM), confocal laser scanning microscopy (CLSM), and subsequent factor analysis image processing (FAMIS) are used to characterize the action of iron nanoparticles and to define their cytotoxicity which is evaluated by enhanced permeability to SYTOX Green, and release of lactate deshydrogenase (LDH). Pro-inflammatory effects are estimated by ELISA in order to quantify IL-8 and MCP-1 secretions. Pro-oxidative effects are measured with hydroethydine (HE).Results: Iron Texas Red nanoparticles accumulate at the cytoplasmic membrane level. They induce a slight LDH release, and have no inflammatory or oxidative effects. However, they enhance the cytotoxic, pro-inflammatory and oxidative effects of 7KC. The accumulation dynamics of SYTOX Green in cells is measured by CLSM to characterize the toxicity of nanoparticles. The emission spectra of SYTOX Green and nanoparticles are differentiated, and corresponding factor images specify the possible capture and cellular localization of nanoparticles in cells.Conclusion: The designed protocol makes it possible to show how Iron Texas Red nanoparticles are captured by cardiomyocytes. Interestingly, whereas these fluorescent iron nanoparticles have no cytotoxic, pro-inflammatory or oxidative activities, they enhance the side effects of 7KC.Keywords: FAMIS, confocal microscopy, iron nanoparticles, 7-ketocholesterol, SYTOX Green, cardiomyocyte

Développement des compétences relationnelles des étudiants en médecine par les jeux de rôle : s’affranchir des savoirs et savoir-faire pour travailler le savoir-être

International audienceLe développement de capacités de communication et de réflexivité dans le cadre de la relation médecin-patient fait partie des objectifs pédagogiques du deuxième cycle des études médicales en France. La réforme du Certificat de Compétence Clinique (arrêté du 8 avril 2013) en demande l’évaluation sous la forme d’une mise en situation clinique auprès d’un patient ou d’une épreuve de simulation. Dans ce contexte nous avons mis en place des jeux de rôle de simulation relationnelle et nous sommes intéressés aux conditions dans lesquelles ils permettent de développer les compétences relationnelles.Une étude observationnelle a été menée dans le cadre de l’enseignement de Sciences Humaines et Sociales auprès des 360 étudiants en troisième année de médecine de la Faculté Lyon Est en septembre 2015. Deux séances de jeux de rôle de 2h avec 4 synopsis de consultations de médecine générale chacune ont été conçues en tenant compte des recommandations de la Haute Autorité de Santé (HAS, 2012). Un questionnaire d’évaluation quantitatif et qualitatif a été utilisé pour recueillir la satisfaction et le ressenti des étudiants concernant ces séances et identifier les conditions qui ont pu favoriser le développement de compétences relationnelles.Parmi les 268 étudiants ayant répondu, 86% ont trouvé les jeux de rôle formateurs, mais 35% des étudiants ne les ont pas trouvé utiles pour se préparer aux stages hospitaliers et 16% ne se sont pas sentis à l’aise pour participer. Les commentaires mentionnaient des difficultés à rendre les jeux de rôle crédibles, ainsi qu’un manque de savoirs et de savoir-faire (conduites à tenir médicales, conduite d’un entretien). Le décalage entre le vécu des étudiants et les situations à simuler suggère qu’à ce stade de leur formation, il pourrait être intéressant de faire jouer le rôle d’étudiant hospitalier plutôt que celui de médecin, pour optimiser le travail du savoir-être relationnel

Mitochondrial dynamics in heart cells: very low amplitude high frequency fluctuations in adult cardiomyocytes and flow motion in non beating Hl-1 cells.

International audienceThe arrangement and movement of mitochondria were quantitatively studied in adult rat cardiomyocytes and in cultured continuously dividing non beating (NB) HL-1 cells with differentiated cardiac phenotype. Mitochondria were stained with MitoTracker Green and studied by fluorescent confocal microscopy. High speed scanning (one image every 400 ms) revealed very rapid fluctuation of positions of fluorescence centers of mitochondria in adult cardiomyocytes. These fluctuations followed the pattern of random walk movement within the limits of the internal space of mitochondria, probably due to transitions between condensed and orthodox configurational states of matrix and inner membrane. Mitochondrial fusion or fission was seen only in NB HL-1 cells but not in adult cardiomyocytes. In NB HL-1 cells, mitochondria were arranged as a dense tubular network, in permanent fusion, fission and high velocity displacements of approximately 90 nm/s. The differences observed in mitochondrial dynamics are related to specific structural organization and mitochondria-cytoskeleton interactions in these cells

Non-beating HL-1 cells for confocal microscopy: application to mitochondrial functions during cardiac preconditioning.

International audienceHL-1, the first cell line with a cardiac phenotype for biological experiments, displays spontaneous electrophysiological and mechanical regular activity, and cyclic calcium movements. We isolated a derived line, devoid of transient movements, for confocal microscopy experiments. These cells do express cardiac proteins: connexin 43, the cardiac isoform of dihydropyridine receptors, desmin, and developmental myosin but have no sarcomeric arrangement. They still possess the electrophysiological characteristics and ionic currents of cardiac cells, among them the cardiac potassium current IKr. We also found diazoxide and glibenclamide sensitive potassium channels with properties similar to IK(ATP) in adult cardiac myocytes. The pacemaker current I(f) was not observed, in agreement with the cells showing excitability but lacking in pacemaker activity. The absence of movement is an advantage for studies which include changes of media in order to follow morphological changes under continuous perfusion. We observed however a basal spontaneous movement of mitochondria and we developed a method to quantify its amplitude using confocal microscopy. No mitochondrial depolarization could be detected when the membrane potential was measured by using very low light photomultiplier and confocal fluorescence imaging under the K(ATP) channel opener diazoxide. Thus cardiac pharmacological preconditioning by K(ATP) channel openers might involve other routes than mitochondrial K channels targeting

New Vidas assay for Toxoplasma-specific IgG avidity: evaluation on 603 sera.

After the development of the new version of the test Vidas Toxo IgG with antigens obtained from tachyzoites cultured on cells, a Vidas avidity test has been recently developed. The aim of this study was to assess the value of the determination of avidity on the new Vidas test. This avidity test was performed on 553 sera obtained from pregnant women whose dates of infection had been determined and on 50 sera obtained from immunosuppressed patients. In the group of infection occurring less than 4 months before sampling, the avidity index was 0.3 for 44/46 sera of pregnant women and for 47/47 sera of immunosuppressed patients. Thus, the new version of avidity test was helpful primarily to rule out that an infection had occurred within the prior 4 months