872 research outputs found

    Photochimiothérapie extra-corporelle (analyse descriptive des patients traités entre mars 2010 et décembre 2012 au CHU d'Angers)

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    La photochimiothérapie extra-corporelle (PEC) est une thérapie cellulaire reposant sur l'association d'une chimiothérapie (8-méthoxypsoralène) photoactivée (UV-A) et d une technique de d aphérèse qui induit une immunomodulation plutôt qu une immunosuppression. Ses principales indications sont le traitement de la maladie du greffon contre l hôte (GvHD) et les lymphomes cutanés T (LCT). Nous décrivons rétrospectivement les patients traités par PEC depuis la disponibilité du traitement au CHU d Angers. Vingt-trois patients ont été traités entre mars 2010 et décembre 2012. La première indication était la GvHD (18 patients). Deux patients ont été traités pour LCT, un patient pour un lichen plan érosif et deux patients dans le cadre d une transplantation rénale. La tolérance à la PEC a été très satisfaisante et aucun effet indésirable sévère n a été observé. Chez les patients atteints de GvHD, une amélioration clinique a été observée dans 61,5% des cas chez les patients. La corticothérapie a été réduite de façon significative chez les patients répondeurs. Aucun facteur prédictif de la réponse au traitement n a été mis en évidence. Notre travail nous a permis d analyser nos pratiques depuis l initiation de la PEC. Globalement, nos pratiques et nos résultats semblent conformes aux recommandations et données existantes. Ce travail met en avant la nécessité d entamer une réflexion autour du choix de l abord vasculaire nécessaire à l initiation du traitement. En dehors des situations consensuelles (GvHD et LCT), l indication de PEC devrait d intégrer dans des protocoles d étude ou après élaboration d une stratégie de soins. Ainsi, le développement de la PEC au sein de notre centre nécessite le maintien d'une cohésion pluridisciplinaire.The extracorporeal photopheresis (ECP) is a cell therapy based on a combination of a photoactivated (UV -A) chemotherapy (8-methoxypsoralen) and an apheresis technique that induces immunomodulation rather than immunosuppression . Its main indications are the treatment of chronic graft versus host disease (GvHD) and cutaneous T-cell lymphoma (CTCL). We describe retrospectively patients treated with ECP since the availability of treatment at the University Hospital of Angers. Twenty-three patients were treated between March 2010 and December 2012. The first indication was the GvHD (18 patients). Two patients were treated for CTLC, a patient for erosive lichen planus and two patients in the setting of renal transplantation. Tolerance to ECP was very good and no severe side effects were observed. Among patients with GvHD, clinical improvement was observed in 61.5 % of cases. Corticosteroids were significantly reduced in responders. No predictor of response to treatment was identified. Our work has allowed us to analyze our practices since the initiation of the ECP in our center. Overall, our practices and results are consistent with the existing data and recommendations. This work highlights the vascular access issue, necessary for the initiation of treatment. Outside consensual situations (GvHD and CTCL), an indication of ECP should be integrated into study protocols or after an established strategy of care. Thus, the development ECP in our center requires the maintenance of a multidisciplinary cohesion.ANGERS-BU Médecine-Pharmacie (490072105) / SudocSudocFranceF

    Typologie des formes d’humus forestières (sous climats tempérés)

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    National audienceLe présent chapitre actualise la typologie des formes d'humus forestières dans le cadre du Référentiel Pédologique 2008. Les horizons de référence O et A sont définis sur la base de caractères directement observables sur le terrain, avec une liste de qualificatifs permettant de décrire toutes les variantes possibles des formes d'humus forestières présentes en climat tempéré. Des clés d'identification sont fournies pour les formes d'humus aérées et hydromorphes, ainsi que des tableaux synoptiques

    Soil, humipedon, forest life and management

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    In recent years, three sections (Humipedon, Copedon and Lithopedon) were recognized in the soil profile. It was then possible to link the first and most biologically active section to the characteristics of the environment and soil genesis. In particular, it is now possible to distinguish organic horizons, mainly produced by arthropods and enchytraeids in cold and acidic or dry and arid environments, from organo-mineral horizons produced by earthworms in more temperate and mesotrophic environments. Each set of horizons can be associated with a humus system or form, with important implications for forestry. Anecic/endogeic earthworms and Mull or Amphi systems are more abundant in the early and late stages of sylvogenesis; by completely recycling litter, earthworms accelerate the availability of organic and inorganic soil nutrients to roots and pedofauna. On the other hand, arthropods and Moder or Tangel systems characterize the intermediate stages of sylvogenesis, where thickening in the organic horizons and the parallel impoverishment/reduction in the underlying organo-mineral horizons are observed. Recognizing the humus system at the right spatial and temporal scale is crucial for the biological management of a forest. This article includes a data review, new data from a doctoral thesis, and recent comparisons of Italian and French investigation

    Bias correction of OMI HCHO columns based on FTIR and aircraft measurements and impact on top-down emission estimates

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    Spaceborne formaldehyde (HCHO) measurements constitute an excellent proxy for the sources of non-methane volatile organic compounds (NMVOCs). Past studies suggested substantial overestimations of NMVOC emissions in state-of-the-art inventories over major source regions. Here, the QA4ECV (Quality Assurance for Essential Climate Variables) retrieval of HCHO columns from OMI (Ozone Monitoring Instrument) is evaluated against (1) FTIR (Fourier-transform infrared) column observations at 26 stations worldwide and (2) aircraft in situ HCHO concentration measurements from campaigns conducted over the USA during 2012–2013. Both validation exercises show that OMI underestimates high columns and overestimates low columns. The linear regression of OMI and aircraft-based columns gives ΩOMI_{OMI}=0,651 Ωairc_{airc}+2,95 x 1015^{15}, molec. cm2^{-2} , with ΩOMI_{OMI} and Ωairc_{airc} the OMI and aircraft-derived vertical columns, whereas the regression of OMI and FTIR data gives ΩOMI_{OMI}= 6,59 ΩFTIR_{FTIR} + 2.02 x 1015^{15}, molec. cm2^{-2} . Inverse modelling of NMVOC emissions with a global model based on OMI columns corrected for biases based on those relationships leads to much-improved agreement against FTIR data and HCHO concentrations from 11 aircraft campaigns. The optimized global isoprene emissions (\sim 445 Tgyr1^{-1}) are 25 % higher than those obtained without bias correction. The optimized isoprene emissions bear both striking similarities and differences with recently published emissions based on spaceborne isoprene columns from the CrIS (Cross-track Infrared Sounder) sensor. Although the interannual variability of OMI HCHO columns is well understood over regions where biogenic emissions are dominant, and the HCHO trends over China and India clearly reflect anthropogenic emission changes, the observed HCHO decline over the southeastern USA remains imperfectly elucidated

    NDACC harmonized formaldehyde time-series from 21 FTIR stations covering a wide range of column abundances

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    Among the more than 20 ground-based FTIR (Fourier transform infrared) stations currently operating around the globe, only a few have provided formaldehyde (HCHO) total column time series until now. Although several independent studies have shown that the FTIR measurements can provide formaldehyde total columns with good precision, the spatial coverage has not been optimal for providing good diagnostics for satellite or model validation. Furthermore, these past studies used different retrieval settings, and biases as large as 50 % can be observed in the HCHO total columns depending on these retrieval choices, which is also a weakness for validation studies combining data from different ground-based stations. For the present work, the HCHO retrieval settings have been optimized based on experience gained from past studies and have been applied consistently at the 21 participating stations. Most of them are either part of the Network for the Detection of Atmospheric Composition Change (NDACC) or under consideration for membership. We provide the harmonized settings and a characterization of the HCHO FTIR products. Depending on the station, the total systematic and random uncertainties of an individual HCHO total column measurement lie between 12 % and 27 % and between 1 and 11×1014 molec cm−2, respectively. The median values among all stations are 13 % and 2.9×1014 molec cm−2 for the total systematic and random uncertainties. This unprecedented harmonized formaldehyde data set from 21 ground-based FTIR stations is presented and its comparison with a global chemistry transport model shows consistency in absolute values as well as in seasonal cycles. The network covers very different concentration levels of formaldehyde, from very clean levels at the limit of detection (few 1013 molec cm−2) to highly polluted levels (7×1016 molec cm−2). Because the measurements can be made at any time during daylight, the diurnal cycle can be observed and is found to be significant at many stations. These HCHO time series, some of them starting in the 1990s, are crucial for past and present satellite validation and will be extended in the coming years for the next generation of satellite missions.This study has been supported by the ESA PRODEX project TROVA (2016–2018) funded by the Belgian Science Policy Office (Belspo)

    NDACC harmonized formaldehyde time series from 21 FTIR stations covering a wide range of column abundances

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    Among the more than 20 ground-based FTIR (Fourier transform infrared) stations currently operating around the globe, only a few have provided formaldehyde (HCHO) total column time series until now. Although several independent studies have shown that the FTIR measurements can provide formaldehyde total columns with good precision, the spatial coverage has not been optimal for providing good diagnostics for satellite or model validation. Furthermore, these past studies used different retrieval settings, and biases as large as 50% can be observed in the HCHO total columns depending on these retrieval choices, which is also a weakness for validation studies combining data from different ground-based stations. For the present work, the HCHO retrieval settings have been optimized based on experience gained from past studies and have been applied consistently at the 21 participating stations. Most of them are either part of the Network for the Detection of Atmospheric Composition Change (NDACC) or under consideration for membership. We provide the harmonized settings and a characterization of the HCHO FTIR products. Depending on the station, the total systematic and random uncertainties of an individual HCHO total column measurement lie between 12% and 27% and between 1 and 11x1014 moleccm-2, respectively. The median values among all stations are 13% and 2.9x1014 moleccm-2 for the total systematic and random uncertainties. This unprecedented harmonized formaldehyde data set from 21 ground-based FTIR stations is presented and its comparison with a global chemistry transport model shows consistency in absolute values as well as in seasonal cycles. The network covers very different concentration levels of formaldehyde, from very clean levels at the limit of detection (few 1013moleccm-2) to highly polluted levels (7x1016moleccm-2). Because the measurements can be made at any time during daylight, the diurnal cycle can be observed and is found to be significant at many stations. These HCHO time series, some of them starting in the 1990s, are crucial for past and present satellite validation and will be extended in the coming years for the next generation of satellite missions

    Effect of natalizumab on disease progression in secondary progressive multiple sclerosis (ASCEND). a phase 3, randomised, double-blind, placebo-controlled trial with an open-label extension

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    Background: Although several disease-modifying treatments are available for relapsing multiple sclerosis, treatment effects have been more modest in progressive multiple sclerosis and have been observed particularly in actively relapsing subgroups or those with lesion activity on imaging. We sought to assess whether natalizumab slows disease progression in secondary progressive multiple sclerosis, independent of relapses. Methods: ASCEND was a phase 3, randomised, double-blind, placebo-controlled trial (part 1) with an optional 2 year open-label extension (part 2). Enrolled patients aged 18–58 years were natalizumab-naive and had secondary progressive multiple sclerosis for 2 years or more, disability progression unrelated to relapses in the previous year, and Expanded Disability Status Scale (EDSS) scores of 3·0–6·5. In part 1, patients from 163 sites in 17 countries were randomly assigned (1:1) to receive 300 mg intravenous natalizumab or placebo every 4 weeks for 2 years. Patients were stratified by site and by EDSS score (3·0–5·5 vs 6·0–6·5). Patients completing part 1 could enrol in part 2, in which all patients received natalizumab every 4 weeks until the end of the study. Throughout both parts, patients and staff were masked to the treatment received in part 1. The primary outcome in part 1 was the proportion of patients with sustained disability progression, assessed by one or more of three measures: the EDSS, Timed 25-Foot Walk (T25FW), and 9-Hole Peg Test (9HPT). The primary outcome in part 2 was the incidence of adverse events and serious adverse events. Efficacy and safety analyses were done in the intention-to-treat population. This trial is registered with ClinicalTrials.gov, number NCT01416181. Findings: Between Sept 13, 2011, and July 16, 2015, 889 patients were randomly assigned (n=440 to the natalizumab group, n=449 to the placebo group). In part 1, 195 (44%) of 439 natalizumab-treated patients and 214 (48%) of 448 placebo-treated patients had confirmed disability progression (odds ratio [OR] 0·86; 95% CI 0·66–1·13; p=0·287). No treatment effect was observed on the EDSS (OR 1·06, 95% CI 0·74–1·53; nominal p=0·753) or the T25FW (0·98, 0·74–1·30; nominal p=0·914) components of the primary outcome. However, natalizumab treatment reduced 9HPT progression (OR 0·56, 95% CI 0·40–0·80; nominal p=0·001). In part 1, 100 (22%) placebo-treated and 90 (20%) natalizumab-treated patients had serious adverse events. In part 2, 291 natalizumab-continuing patients and 274 natalizumab-naive patients received natalizumab (median follow-up 160 weeks [range 108–221]). Serious adverse events occurred in 39 (13%) patients continuing natalizumab and in 24 (9%) patients initiating natalizumab. Two deaths occurred in part 1, neither of which was considered related to study treatment. No progressive multifocal leukoencephalopathy occurred. Interpretation: Natalizumab treatment for secondary progressive multiple sclerosis did not reduce progression on the primary multicomponent disability endpoint in part 1, but it did reduce progression on its upper-limb component. Longer-term trials are needed to assess whether treatment of secondary progressive multiple sclerosis might produce benefits on additional disability components. Funding: Biogen

    Eosinophilic granulomatosis with polyangiitis (Churg–Strauss) (EGPA) Consensus Task Force recommendations for evaluation and management

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    AbstractObjectiveTo develop disease-specific recommendations for the diagnosis and management of eosinophilic granulomatosis with polyangiitis (Churg–Strauss syndrome) (EGPA).MethodsThe EGPA Consensus Task Force experts comprised 8 pulmonologists, 6 internists, 4 rheumatologists, 3 nephrologists, 1 pathologist and 1 allergist from 5 European countries and the USA. Using a modified Delphi process, a list of 40 questions was elaborated by 2 members and sent to all participants prior to the meeting. Concurrently, an extensive literature search was undertaken with publications assigned with a level of evidence according to accepted criteria. Drafts of the recommendations were circulated for review to all members until final consensus was reached.ResultsTwenty-two recommendations concerning the diagnosis, initial evaluation, treatment and monitoring of EGPA patients were established. The relevant published information on EGPA, antineutrophil-cytoplasm antibody-associated vasculitides, hypereosinophilic syndromes and eosinophilic asthma supporting these recommendations was also reviewed.DiscussionThese recommendations aim to give physicians tools for effective and individual management of EGPA patients, and to provide guidance for further targeted research

    The Relationship between Population Structure and Aluminum Tolerance in Cultivated Sorghum

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    Background: Acid soils comprise up to 50% of the world's arable lands and in these areas aluminum (Al) toxicity impairs root growth, strongly limiting crop yield. Food security is thereby compromised in many developing countries located in tropical and subtropical regions worldwide. In sorghum, SbMATE, an Al-activated citrate transporter, underlies the Alt(SB) locus on chromosome 3 and confers Al tolerance via Al-activated root citrate release. Methodology: Population structure was studied in 254 sorghum accessions representative of the diversity present in cultivated sorghums. Al tolerance was assessed as the degree of root growth inhibition in nutrient solution containing Al. A genetic analysis based on markers flanking Alt(SB) and SbMATE expression was undertaken to assess a possible role for Alt(SB) in Al tolerant accessions. In addition, the mode of gene action was estimated concerning the Al tolerance trait. Comparisons between models that include population structure were applied to assess the importance of each subpopulation to Al tolerance. Conclusion/Significance: Six subpopulations were revealed featuring specific racial and geographic origins. Al tolerance was found to be rather rare and present primarily in guinea and to lesser extent in caudatum subpopulations. Alt(SB) was found to play a role in Al tolerance in most of the Al tolerant accessions. A striking variation was observed in the mode of gene action for the Al tolerance trait, which ranged from almost complete recessivity to near complete dominance, with a higher frequency of partially recessive sources of Al tolerance. A possible interpretation of our results concerning the origin and evolution of Al tolerance in cultivated sorghum is discussed. This study demonstrates the importance of deeply exploring the crop diversity reservoir both for a comprehensive view of the dynamics underlying the distribution and function of Al tolerance genes and to design efficient molecular breeding strategies aimed at enhancing Al tolerance.CGIAR[G3007.04]McKnight FoundationFundacao de Amparo a Pesquisa do Estado de Minas Gerais (FAPEMIG)National Council for Scientific and Technological Development (CNPq
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