5 research outputs found

    Étude des complĂ©mentaritĂ©s entre gestion dynamique Ă  la ferme et gestion statique en collection: Cas de la variĂ©tĂ© de blĂ© Rouge de Bordeaux

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    National audienceWhile on-farm conservation was considered minor in the development of the National Charter on Genetic Resources in 1998, there is increasing recognition of its important role in the conservation of genetic diversity. In addition to amateur gardening associations that save and exchange seeds, farmers in France have formed networks around systems of shared seed conservation and exchanges, with the goal of protecting the diversity of cultivated species. Parallel to this, the contribution of farmers to the dynamic management of agricultural biodiversity has been recognized by many scientific studies and in international treaties. These developments led us to examine the complementary nature of on-farm and gene-bank conservation efforts in terms of the management of genetic resources. This study, which combines ethnobotanical and genetic approaches, was conducted on bread wheat, for which France has a national collection of 10 000 accessions. There is also an active network of farmers who cultivate historic varieties and landraces, including the Rouge de Bordeaux, which was chosen for a detailed study. By conducting individual interviews with farmers, we were able to understand better their management practices, seed exchanges with other farmers and with the national collection, and strategies for maintaining and selecting this variety on their own farms. We characterized the genetic diversity conserved by several farmers and in the samples preserved in the national collection for Rouge de Bordeaux by using a comparative genetic analysis of samples obtained from farmers and from the collection, in light of the management practices and exchange networks that exist among farmers and between farmers and the national collection. Our results demonstrate that the diversity of these populations is far from being redundant. While certain samples are quite homogeneous and similar to samples from the national collection, others are highly heterogeneous. There is also a high degree of genetic differentiation among populations, with clear groupings of populations identified. The structure of the diversity may be explained by the structure of exchanges and the development of local adaptation within the populations to environmental conditions and management practices, and by differing strategies of selection and conservation. Further analysis will help us understand more precisely what defines a variety and what type of genetic diversity or phenotypic traits are conserved with different management strategies. Our results also support a greater degree of seed circulation between farmers' fields and the national collection, to conserve the adaptive potential and a broader range of genetic diversity for each variety.ConsidĂ©rĂ©e comme mineure lors de la rĂ©daction de la Charte nationale des ressources gĂ©nĂ©tiques en 1998, la gestion Ă  la ferme a depuis gagnĂ© en importance et en reconnaissance. En effet, aprĂšs les associations de jardiniers amateurs, des rĂ©seaux d'agriculteurs se sont fĂ©dĂ©rĂ©s en France autour de systĂšmes mutualistes de sĂ©lection/conservation de la diversitĂ© cultivĂ©e. ParallĂšlement, la contribution des paysans Ă  la gestion dynamique de l'agrobiodiversitĂ© a Ă©tĂ© scientifiquement et institutionnellement reconnue. Ces Ă©lĂ©ments nous ont conduit Ă  examiner les complĂ©mentaritĂ©s dans la gestion des ressources gĂ©nĂ©tiques Ă  la ferme et en collection. Cette Ă©tude, qui croise des approches ethnobotanique et gĂ©nĂ©tique, a Ă©tĂ© menĂ©e sur le blĂ© tendre pour lequel il existe en France une collection nationale de 10 000 accessions et un rĂ©seau actif d'agriculteurs-collectionneurs de variĂ©tĂ©s. Pour la variĂ©tĂ© Rouge de Bordeaux, nous avons tentĂ© de caractĂ©riser la diversitĂ© dans les champs et en collection, en procĂ©dant Ă  une analyse gĂ©nĂ©tique d'Ă©chantillons obtenus auprĂšs d'agriculteurs et auprĂšs de la collection. Nos rĂ©sultats montrent que les ressources gĂ©nĂ©tiques conservĂ©es dans les deux compartiments sont loin d'ĂȘtre redondantes. La structuration de la diversitĂ© s'explique par les rĂ©seaux d'Ă©changes de semences (entre paysans, et entre les paysans et la collection), par l'adaptation locale des populations aux conditions du milieu et aux pratiques de culture, et par les pratiques de sĂ©lection/conservation. Ces rĂ©sultats appellent des analyses complĂ©mentaires pour comprendre prĂ©cisĂ©ment ce qui est conservĂ©/cultivĂ© sous un nom variĂ©tal donnĂ©, et plaident en faveur d'une circulation accrue des semences entre champs et collection

    Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19

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    IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19. Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19. DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non–critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022). INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days. MAIN OUTCOMES AND MEASURES The primary outcome was organ support–free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes. RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support–free days among critically ill patients was 10 (–1 to 16) in the ACE inhibitor group (n = 231), 8 (–1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support–free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively). CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570

    A Novel 8-Predictors Signature to Predict Complicated Disease Course in Pediatric-onset Crohn’s Disease: A Population-based Study

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    International audienceBackground The identification of patients at high risk of a disabling disease course would be invaluable in guiding initial therapy in Crohn’s disease (CD). Our objective was to evaluate a combination of clinical, serological, and genetic factors to predict complicated disease course in pediatric-onset CD. Methods Data for pediatric-onset CD patients, diagnosed before 17 years of age between 1988 and 2004 and followed more than 5 years, were extracted from the population-based EPIMAD registry. The main outcome was defined by the occurrence of complicated behavior (stricturing or penetrating) and/or intestinal resection within the 5 years following diagnosis. Lasso logistic regression models were used to build a predictive model based on clinical data at diagnosis, serological data (ASCA, pANCA, anti-OmpC, anti-Cbir1, anti-Fla2, anti-Flax), and 369 candidate single nucleotide polymorphisms. Results In total, 156 children with an inflammatory (B1) disease at diagnosis were included. Among them, 35% (n = 54) progressed to a complicated behavior or an intestinal resection within the 5 years following diagnosis. The best predictive model (PREDICT-EPIMAD) included the location at diagnosis, pANCA, and 6 single nucleotide polymorphisms. This model showed good discrimination and good calibration, with an area under the curve of 0.80 after correction for optimism bias (sensitivity, 79%, specificity, 74%, positive predictive value, 61%, negative predictive value, 87%). Decision curve analysis confirmed the clinical utility of the model. Conclusions A combination of clinical, serotypic, and genotypic variables can predict disease progression in this population-based pediatric-onset CD cohort. Independent validation is needed before it can be used in clinical practice

    Effect of Antiplatelet Therapy on Survival and Organ Support–Free Days in Critically Ill Patients With COVID-19

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