Maladie coeliaque, dernières données sur la génétique (avancées, perspectives)

LYON1-BU Santé (693882101) / SudocRENNES1-BU Santé (352382103) / SudocSudocFranceF

Implantation ionique d'azote à basse énergie et flux élevé dans l'acier austénitique 34L

Nous avons réalisé une étude expérimentale des phénomènes d'implantation ionique d'azote dans l'acier inoxydable austénitique 304L à basse énergie (1 KeV), à fort courant ionique (0,5-1 mA/cm2) et fluence élevée (4.10 at./cm2), à des températures modérées (250-550C). L'analyse des profils de concentration d'azote (NRA, SDL) ainsi que celle des transformations microstructurales (DRX, MET, SIMS-XPS) ont été effectuées afin d'établir des corrélations avec les améliorations des propriétés mécaniques de surface. Tout d'abord, un seuil de température, situé vers 270C, a été mis en évidence au dessus duquel les profondeurs de pénétration de l'azote augmentent considérablement avec la température, le courant et la fluence, les concentrations en azote étant de l'ordre de 20 at. % sur plusieurs microns. Jusqu'à 430C, la couche nitrurée est essentiellement constituée d'une solution solide métastable d'insertion d'azote dans l'austénite. Pour des températures plus élevées, on observe la formation d'une matrice cubique centrée contenant des précipités de nitrure de chrome. En surface, l'implantation produit une augmentation très nette de la rugosité et, en volume, introduit une très grande densité de dislocations et provoque une fragmentation très importante de la microstructure. Nous avons pu mettre en évidence au sein de la solution solide, des liaisons chimiques nettement préférentielles entre les atomes d'azote et de chrome, avec une énergie de liaison inférieure à celle du composé défini CrN. Le modèle proposé pour expliquer la formation des couches nitrurées épaisses fait intervenir des mécanismes tels que la relocalisation des atomes déplacés dans la couche de surface par les ions incidents, le piégeage des atomes d'azote par ceux de chrome, la relaxation des défauts de surface qui peut intervenir par recombinaison directe lacune-adatome et par migration en volume des lacunes pour une température suffisante. La couche nitrurée présente une dureté cinq fois supérieure à celle de l'austénite, ce qui entraîne une diminution considérable de la vitesse d'usure et une modification profonde des faciès de dégradation.ORLEANS-BU Sciences (452342104) / SudocSudocFranceF

Childhood Trauma increases suicidal behaviour in a treatment-resistant depression population: a FACE-DR report

Objective: In addition to heredity, exposure to early-life adversity is an important predisposing risk factor of suicidal behaviour. Although the association between Childhood Trauma (CT) and suicide risk is well documented, interactions between CT and suicidal behaviour in Treatment-Resistant Depression (TRD) populations have received little coverage. This study aimed to evaluate i) association between CT and suicidal behaviour in a TRD population, and ii) the role of personality traits and impulsiveness as potential factors of mediation in these associations. Methods: Patients were recruited from a cohort of the French network of TRD expert centers. Depressive symptom severity, CT, suicidal behaviour, personality traits, and impulsiveness were assessed with the Montgomery-Åsberg Depression Rating Scale (MADRS), the Childhood Trauma Questionnaire (CTQ), the Columbia Suicide Severity Rating Scale (CSSRS), the Structured Clinical Interview for DSM-IV, the Big Five Inventory, and the Barratt Impulsivness Scale (BIS) respectively. Results: Among the 256 patients with a baseline CTQ, in relation to suicide risk for the current depressive episode, we found an association with the total CTQ scores mediated by the intensity of the current episode in a model adjusted for age and sex (total effect: β = 0.171 ; p = 0.011, direct effect: β = 0.135 ; p = 0.043 ; indirect effect: β = 0.036 ; p = 0.048). Focusing on CT subtypes, we detected an association between suicide risk and physical neglect in a model adjusted for age and sex (β = 0.301 ; p = 0.002), without any mediation by the intensity of the current episode. There was no mediation effect from personality traits nor impulsiveness. With regards to CSSRS to assess suicidal ideation, we did not find any association with the total CTQ score and CT subtype scores. Conclusion: We report a strong association between suicidal behaviour and CT (in particular childhood physical neglect) in a TRD population.Sorbonne Universités à Paris pour l'Enseignement et la Recherch

Clinical predictors of recurrences in bipolar disorders type 1 and 2: A FACE-BD longitudinal study

Objective: To examine which characteristics predict the time to a first mood recurrence at three years in Bipolar Disorder type I (BD-I) and type II (BD-II). Methods: Individuals with BD were followed up to 3 years. Turbull's extension of the Kaplan-Meier analysis for interval-censored data was used to estimate the cumulative probability of recurrence over time. Separate models were performed according to BD subtype to determine which baseline factors were predictive of recurrences and were adjusted for age, gender and educational level. Results: We included 630 individuals with BD-I and 505 with BD-II. The first recurrence of any polarity occurred earlier in BD-II (p = 0.03). The first depressive recurrence occurred earlier in BD-II (p < 0.0001), whereas the first (hypo)manic recurrence occurred earlier in BD-I (p = 0.0003). In BD-I, the clinical variables that were associated to the time to a first mood recurrence were depressive symptoms, lifetime rapid cycling, global activation and the number of psychotropic medications at baseline. In BD-II, the time to a first recurrence was associated with a younger age at onset of BD and a higher number of lifetime mood episodes. The Areas Under the Curve for both models were moderate. Conclusion: Predictors of recurrences showed few specificities to BD-I or BD-II. The ability to predict recurrences in BD based on socio-demographic and clinical variables remained too moderate for a transfer in daily practice. This study highlights the need for further studies that would include other types of predictors, such as molecular, cognitive or neuro-imaging ones, to achieve an accurate level of prediction of recurrences in BD.Sorbonne Universités à Paris pour l'Enseignement et la RechercheFondaMental-Cohorte

Mitochondrial Biomarkers and Metabolic Syndrome in Bipolar Disorder

International audienceThe object of this study is test whether mitochondrial blood-based biomarkers are associated with markers of metabolic syndrome in bipolar disorder, hypothesizing higher lactate but unchanged cell-free circulating mitochondrial DNA levels in bipolar disorder patients with metabolic syndrome. In a cohort study, primary testing from the FondaMental Advanced Centers of Expertise for bipolar disorder (FACE-BD) was conducted, including 837 stable bipolar disorder patients. The I-GIVE validation cohort consists of 237 participants: stable and acute bipolar patients, non-psychiatric controls, and acute schizophrenia patients. Multivariable regression analyses show significant lactate association with triglycerides, fasting glucose and systolic and diastolic blood pressure. Significantly higher levels of lactate were associated with presence of metabolic syndrome after adjusting for potential confounding factors. Mitochondrial-targeted metabolomics identified distinct metabolite profiles in patients with lactate presence and metabolic syndrome, differing from those without lactate changes but with metabolic syndrome. Circulating cell-free mitochondrial DNA was not associated with metabolic syndrome. This thorough analysis mitochondrial biomarkers indicate the associations with lactate and metabolic syndrome, while showing the mitochondrial metabolites can further stratify metabolic profiles in patients with BD. This study is relevant to improve the identification and stratification of bipolar patients with metabolic syndrome and provide potential personalized-therapeutic opportunities

Diet quality and associations with lactate and metabolic syndrome in bipolar disorder

International audienceBackground: Nutrition is largely affected in bipolar disorder (BD), however, there is a lack of understanding on the relationship between dietary categories, BD, and the prevalence of metabolic syndrome. The objective of this study is to examine dietary trends in BD and it is hypothesized that diets with increased consumption of seafood and high-fiber carbohydrates will be correlated to improved patient outcomes, and a lower frequency of metabolic syndrome.Methods: This retrospective cohort study includes two French cohorts. The primary cohort, FACE-BD, includes 268 stable BD patients. The second cohort, I-GIVE, includes healthy controls, both stable and acute BD and schizophrenia patients. Four dietary categories were assessed: meat, seafood, low-fiber and high-fiber carbohydrates. Dietary data from two food frequency questionnaires were normalized using min-max scaling and assessed using various statistical analyses.Results: In our primary cohort, the increased high-fiber carbohydrate consumption was correlated to lower prevalence of metabolic syndrome and improved mood. Low-fiber carbohydrate consumption is associated with higher BMI, while higher seafood consumption was correlated to improved mood and delayed age of onset. Results were not replicated in our secondary cohort.Limitations: Our populations were small and two different dietary questionnaires were used; thus, results were used to examine similarities in trends.Conclusions: Overall, various dietary trends were associated with metabolic syndrome, BMI, lactate, mood and age of onset. Improving our understanding of nutrition in BD can provide mechanistic insight, clinically relevant nutritional guidelines for precision medicine and ultimately improve the quality of lives for those with BD