125 research outputs found

    Estimation de l'échelle des néoplasies en coloscopie par détection de la profondeur de défocalisation

    Get PDF
    National audienceLa coloscopie est l'examen médical privilégié dans le cadre du diagnostic et du traitement des maladies colorectales. Cette technique qualifiée de peu invasive permet aux gastro-entérologues d'explorer la cavité du côlon et d'ôter les néoplasies - proliférations cellulaires - telles que les polypes qui peuvent évoluer en tumeurs malignes. La taille, la texture ainsi que la forme des néoplasies constituent des critères essentiels à leurs diagnostics. L'estimation de la taille est cependant difficile à réaliser de part la perte de l'information de profondeur de la scène imagée par le gastro-entérologue. Nous proposons une amélioration de notre technique de détection de la Profondeur de Défocalisation (PD) permet- tant l'estimation de l'échelle des scènes endoscopiques par extraction de la PD au sein d'une séquence vidéo. L'estimation conjointe du suivi affine de la néoplasie au cours de la séquence vidéo et du flou de mise au point permet d'inférer avec une meilleure précision la taille des néoplasies. Par ailleurs, la méthode proposée est mieux adaptée aux conditions réelles de coloscopie pour lesquelles la manipulation du gastroscope peut être délicate

    Estimation de l'échelle en coloscopie monoculaire par quantification du flou optique : étude de faisabilité

    Get PDF
    Session "Articles"National audienceLa coloscopie est aujourd'hui la procédure médicale privilégiée dans le cadre du diagnostic et du traitement des pathologies en gastroentérologie. Ce mode opératoire qualifié de "mini-invasif" repose sur l'utilisation d'un instrument optique flexible, le flexoscope, qui est introduit par voie basse dans le corps du patient pour permettre l'exploration du côlon. L'intervention est réalisée par un gastroentérologue qui s'appuie sur les images diffusées sur un moniteur afin d'établir un diagnostic et éventuellement procéder à la résection d'excroissances tumorales (néoplasies) si celles ci s'avèrent malignes. La taille de ces excroissances constitue une information essentielle a leurs diagnostics mais elles s'avèrent difficile à estimer pour le praticien qui ne dispose pas de l'information d'échelle de l'organe exploré. Les paramètres du système optique monofocale des flexoscope sont fixes et l'équipement est difficilement modifiable pour envisager l'intégration de méthodes actives de mesures. Cette étude de faisabilité propose une procédure permettant l'estimation de l'échelle des scènes coloscopiques basée sur l'estimation de la fonction de transfert du système optique du flexoscope par quantification du flo

    Pareto-optimalité combinée à des jeux de Nash en optimisation multiobjectif hiérarchisée de performance vol d’un avion

    Get PDF
    This report reflects a cooperation between the Inria Project Team Acumes and the Information Processing and Systems Department (DTIS) of Onera Toulouse. We present a case study of prioritized multi-objective optimization of the flight performance of an Airbus-A320-type aircraft in terms of take-off fuel mass (f1), operational empty weight (f2) and ascent-to-cruise- altitude duration (f3). The optimization is subject to functional constraints: interval bound on static margin and upper bound on wing span. Six design variables are considered defining geometry, mean aerodynamic chord and take-off thrust potential. Designs are evaluated by means of the FAST-OAD open-source software developed by ONERA and ISAE-SUPAERO, and the prioritized optimization is conducted by the Inria Nash-MGDA software. From a point of Pareto-optimality of the sole pair (f1, f2), considered preponderant, the climb duration f3 is reduced drastically by a one-shot procedure establishing a continuum of Nash equilibria. The application of this procedure is far less computationally demanding than is the numerical establishment of the Pareto-front associated with the three cost functions together, while the Pareto-optimality of the preponderant cost functions (f1,f2) is only marginally degraded.Ce rapport est le fruit d’une coopération entre l’équipe-projet Inria Acumes et le Département Traitement et Systèmes de l’Information (DTIS) de l’Onera Toulouse. Nous présentons une étude de cas d’optimisation multi-objectif hiérarchisée de performance vol d’un avion de type Airbus-A320 en termes de masse de carburant au décollage (f1), de masse opérationnelle à vide (f2) et de durée de montée à l’altitude de croisière (f3). L’optimisation est soumise à des contraintes fonctionnelles: borne d’intervalle sur la marge statique et borne supérieure sur l’envergure de l’aile. Six variables de conception sont considérées définissant la géométrie, la corde aérodynamique moyenne et le potentiel de poussée au décollage. Les concepts sont éval- ués au moyen du logiciel open-source FAST-OAD développé par l’ONERA et l’ISAE-SUPAERO, et l’optimisation hiérarchisée est conduite par le logiciel Inria Nash-MGDA. À partir d’un point de Pareto-optimalité du seul couple (f1,f2), considéré comme prépondérant, la durée de montée f3 est réduite drastiquement par une procédure directe de calcul d’un continuum d’équilibres de Nash. L’application de cette procédure prend beaucoup moins de temps calcul que l’établissement numérique du front de Pareto associé aux trois fonctions de coût ensemble, tandis que l’optimalité de Pareto des fonctions de coût prépondérantes (f1,f2) n’est que marginalement dégradée

    High light stress induces H2O2 production and accelerates fruit ripening in tomato

    Get PDF
    Increased synthesis of H2O2 is observed during the initiation of fruit ripening. However, its association with plant cell processes triggering the maturation of fruit has not yet been demonstrated. The aim of this work is to investigate whether H2O2 participates in the tomato ripening process and particularly through its association with the ethylene signaling pathway. The experiments were carried out with two ethyl methanesulfonate mutant lines of Micro-Tom tomato deficient in GDP-L-galactose phosphorylase activity and displaying lower ascorbic acid content than the corresponding parental genotype (i.e. wild type). Plants were subjected to a high irradiance (HI) treatment to stimulate H2O2 synthesis. HI treatment enhanced H2O2 production and reduced the timing of fruit ripening in both mutants and wild-type fruits. These results could be linked to an increase of the expression of H2O2-related genes and changes in the expression of ethylene-related genes. The fruit H2O2 production increased or decreased after applying the treatments that induced ethylene synthesis or blocked its action, respectively. The results presented in this work give an evidence of the association of redox and hormonal components during fruit ripening in which H2O2 participates downstream in the events regulated by ethylene.Fil: Steelheart Molina, Maria Charlotte. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Fisiología Vegetal. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Instituto de Fisiología Vegetal; ArgentinaFil: Alegre, Matias Leonel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Fisiología Vegetal. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Instituto de Fisiología Vegetal; ArgentinaFil: Baldet, Pierre. Universite de Bordeaux; FranciaFil: Rothan, Christophe. Universite de Bordeaux; FranciaFil: Bres, Cecile. Universite de Bordeaux; FranciaFil: Just, Daniel. Universite de Bordeaux; FranciaFil: Okabe, Yoshihiro. Tsukuba University; JapónFil: Ezura, Hiroshi. Tsukuba University; JapónFil: Ganganelli, Inti Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Fisiología Vegetal. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Instituto de Fisiología Vegetal; ArgentinaFil: Gergoff Grozeff, Gustavo Esteban. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Fisiología Vegetal. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Instituto de Fisiología Vegetal; ArgentinaFil: Bartoli, Carlos Guillermo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Fisiología Vegetal. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Instituto de Fisiología Vegetal; Argentin

    IL-9 Integrates the Host-Candida Cross-Talk in Vulvovaginal Candidiasis to Balance Inflammation and Tolerance

    Get PDF
    Vulvovaginal candidiasis (VVC) is a common fungal infection caused by Candida albicans. The antifungal therapy represents the standard of care but due to the high costs of treatment and to the inability to prevent recurrences, the development of alternative therapeutic approaches is much-awaited. Recently, we have shown that the pathogenesis of C. albicans in the gut is modulated by IL-9, a pleiotropic cytokine able to promote both inflammation and tolerance during C. albicans infection. Herein, by using a mouse model of VVC, we similarly demonstrated that IL-9 might exert a dual role in VVC by contributing to inflammation during the initial immune activation and promoting resolution thereafter. Specifically, IL-9 has a pro-inflammatory activity at the onset of VVC by promoting NLRP3 inflammasome activity and mucosal mast cells expansion but a tolerogenic role in the resolution phase by promoting IL-1Ra production and connective tissue mast cells activation. We further show that a timely IL-9 neutralization at the onset of the inflammatory response ameliorated symptoms and vaginal pathology. Given that vaginal fluids from patients with recurrent VVC had higher levels of IL-9, these findings, by providing novel insights into the pathogenesis of VVC, may pave the way for alternative therapeutic strategies based on IL-9 neutralization

    IL-9 and Mast Cells Are Key Players of Candida albicans Commensalism and Pathogenesis in the Gut

    Get PDF
    Summary: Candida albicans is implicated in intestinal diseases. Identifying host signatures that discriminate between the pathogenic versus commensal nature of this human commensal is clinically relevant. In the present study, we identify IL-9 and mast cells (MCs) as key players of Candida commensalism and pathogenicity. By inducing TGF-β in stromal MCs, IL-9 pivotally contributes to mucosal immune tolerance via the indoleamine 2,3-dioxygenase enzyme. However, Candida-driven IL-9 and mucosal MCs also contribute to barrier function loss, dissemination, and inflammation in experimental leaky gut models and are upregulated in patients with celiac disease. Inflammatory dysbiosis occurs with IL-9 and MC deficiency, indicating that the activity of IL-9 and MCs may go beyond host immunity to include regulation of the microbiota. Thus, the output of the IL-9/MC axis is highly contextual during Candida colonization and reveals how host immunity and the microbiota finely tune Candida behavior in the gut. : Deciphering the mechanisms by which Candida albicans promotes either pathology or protective tolerance in the gut could be clinically relevant. Renga et al. show a key role for IL-9 and mast cells in promoting either inflammatory dysbiosis and pathology or tolerance in leaky gut models and human celiac disease. Keywords: IL-9, mast cells, Candida albicans, intestinal inflammation, IDO1, celiac diseas

    Vaccine breakthrough hypoxemic COVID-19 pneumonia in patients with auto-Abs neutralizing type I IFNs

    Full text link
    Life-threatening `breakthrough' cases of critical COVID-19 are attributed to poor or waning antibody response to the SARS- CoV-2 vaccine in individuals already at risk. Pre-existing autoantibodies (auto-Abs) neutralizing type I IFNs underlie at least 15% of critical COVID-19 pneumonia cases in unvaccinated individuals; however, their contribution to hypoxemic breakthrough cases in vaccinated people remains unknown. Here, we studied a cohort of 48 individuals ( age 20-86 years) who received 2 doses of an mRNA vaccine and developed a breakthrough infection with hypoxemic COVID-19 pneumonia 2 weeks to 4 months later. Antibody levels to the vaccine, neutralization of the virus, and auto- Abs to type I IFNs were measured in the plasma. Forty-two individuals had no known deficiency of B cell immunity and a normal antibody response to the vaccine. Among them, ten (24%) had auto-Abs neutralizing type I IFNs (aged 43-86 years). Eight of these ten patients had auto-Abs neutralizing both IFN-a2 and IFN-., while two neutralized IFN-omega only. No patient neutralized IFN-ss. Seven neutralized 10 ng/mL of type I IFNs, and three 100 pg/mL only. Seven patients neutralized SARS-CoV-2 D614G and the Delta variant (B.1.617.2) efficiently, while one patient neutralized Delta slightly less efficiently. Two of the three patients neutralizing only 100 pg/mL of type I IFNs neutralized both D61G and Delta less efficiently. Despite two mRNA vaccine inoculations and the presence of circulating antibodies capable of neutralizing SARS-CoV-2, auto-Abs neutralizing type I IFNs may underlie a significant proportion of hypoxemic COVID-19 pneumonia cases, highlighting the importance of this particularly vulnerable population

    Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

    Get PDF
    Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat
    corecore