Réactivité en polycondensation. Mesure d’un effet de substitution sur unité multifonctionnelle

La réactivité des sites d’une même classe appartenant à un polyol entrant dans la synthèse d’un polyuréthane a été étudiée par condensation du polyol avec un monoisocyanate. A partir des résultats de la chromatographie par perméation de gel du milieu réactionnel à divers taux de réaction, une méthode originale a été mise au point permettant de tracer les courbes de distribution des différentes espèces moléculaires obtenues, sans exiger un étalonnage préalable à l’aide de ces espèces, parfois difficiles à isoler à l’état pur. L’examen de ces courbes de distribution révèle une non équiréactivité des sites alcool du polyol étudié, attribuable à un effet de substitution négatif non linéaire dont l’intensité varie avec la température et la nature du milieu réactionnel. La comparaison des courbes de distribution expérimentales aux résultats de l'analyse cinétique de la réaction permet de quantifier l’effet de substitution. La méthode proposée est très générale; elle est susceptible de s’appliquer à tout composé multifonctionnel polycondensable quelle que soit la nature des sites réactifs qu’il porte

Multiangle Light Scattering and Viscometric Detector for Size-Exclusion Chromatography

A new miniaturised Light Scattering (LS) apparatus coupled with a capillary viscometer has been developed which analyses sequentially small size fractions of eluent (1 cm$^3$). The apparatus can be used in an autonomous manner in order to obtain the weight-average molar mass ($M_{\rm w}$), the $z$-average radius of gyration ($R_{\rm g}$), the second virial coefficient ($A_2$), the intrinsic viscosity ([ $\eta$] ) and the Huggins constant ($k$) by analysing a given polymer sample at different concentrations. The device can be coupled to a standard Size-Exclusion Chromatography chain in which the detector not only provides mean values, but also the evolution of [ $\eta$] , $M_{\rm w}$ and $R_{\rm g}$. as a function of elution volume ($V_{\rm e}$). Specific calibration curves ($\log(M_{\rm w}) = f (V_{\rm e})$) can be constructed for any sample, and then be used without the combined detector. In this way the molecular weight dependence of [ $\eta$] and $R_{\rm g}$ is readily obtained. Moreover, the special design of the detector allows simple collection of fractions. A number of problems which need to be solved in order to allow an efficient use of the detector are discussed. Results on polystyrene standards illustrate the good performance of the apparatus

Communication between mother and infant (fetus or newborn)

International audienceWe measured changes in Heart Rate Variability (H.R.V.) while mother either talked about her baby to an adult (1) or communicated directly with the baby either vocally (2) or silently (3) (n=180 fetus, n=140 neonates).We previously showed that the % of fetus reacting to silent communication (3) was equal to those reacting to a vocal emission: 38% and 37% respectively while (1) elicited only 29% of responses.Babies reacted globally less than fetuses, but with the same proportion of responses: 27% for (2), 34% for (3) and 21% for (1). Here, to compare the 3 tests, H.R.V. was averaged every 30 sec. for 5 min. before, during and after each stimulus on 100 fetuses and 70 newborns. No significant effects were observed when computing all subjects, for some entered the pre-experimental phase in an agitated state (state 3 or 4) with a high H.R.V., while others were calm with a low H.R.V. (state 1 or 2). The latter increased its variability during stimulation while the high H.R.V. group decreased it.When analyzed separately, both groups became significant in all of the series. Babies, as a group, are less significant than fetuses, but also react to all three experimental conditions, including silent communication. This last unexpected result will be discussed for mothers who stated that they made extensive use of this mode of communication with their baby

Peptidyl arginine deiminase autoimmunity and the development of ACPA in rheumatoid arthritis. The "hapten carrier" model

International audienceOBJECTIVE:Rheumatoid arthritis (RA) is preceded by autoantibodies to citrullinated proteins (ACPA). Citrullins are arginine residues which have been modified by Peptidyl Arginyl Deiminases (PADs). PAD4 is the target of autoantibodies in RA. This suggests that ACPAs could arise because PAD4 is recognized by T cells which help the production of autoantibodies to proteins bound by PAD4. We previously found evidence for this hapten carrier model in mice. Here, we looked for evidence for this model in humans.METHODS:We analyzed antibody and T cell proliferation to PAD4 in 41 RA patients and 36 controls. We tested binding of 65 peptides from PAD4 to 5 HLA-DR alleles (DRB1*04:01, *04:02, *04:04, *01:01, *07:01). We selected 11 peptides from PAD4 for proliferation studies in 22 patients with RA and 27 controls. We performed FACS analysis for CD3, CD4, CD154 and TNF alpha expression after PAD4 stimulation on the PBLs of an extra 10 RA patients and 7 healthy controls RESULTS: Only patients with RA have both antibodies and T cell responses to PAD4. T cell response to peptide 8 (p8), a peptide from PAD4, is associated with RA, ACPAs and the shared epitope.CONCLUSION:ACPA immunity is associated with antibodies and T cell response to PAD4 and T cell response to peptides from PAD4. This is consistent with a hapten carrier model in which PAD4 is the carrier and citrullinated proteins are the hapten

Cell Analysis from Dried Blood Spots: New Opportunities in Immunology, Hematology, and Infectious Diseases

International audienc

SARS-CoV-2 spike protein induces a differential monocyte activation that may contribute to age bias in COVID-19 severity

Abstract A strong bias related to age is observed in COVID-19 patients with pediatric subjects developing a milder disease than adults. We hypothesized that a specific SARS-CoV-2 effect conjugated with preexisting differences in the immune systems may explain this. Using flow cytometry, we investigated basal immune differences in a cohort consisting of 16 non-infected young and 16 aged individuals and further leveraged an in vitro whole blood model of SARS-CoV-2 infection so that functional differences could be mined as well. In short, blood diluted in culture media was incubated 5 or 24 h with the trimeric spike protein or controls. Following unsupervised analysis, we first confirmed that the immune lymphoid and myeloid systems in adults are less efficient and prone to develop higher inflammation than those in children. We notably identified in adults a higher CD43 lymphocyte expression, known for its potentially inhibitory role. The spike protein induced different responses between adults and children, notably a higher increase of inflammatory markers together with lower monocyte and B cell activation in adults. Interestingly, CD169, a CD43 ligand overexpressed in COVID-19 patients, was confirmed to be strongly modulated by the spike protein. In conclusion, the spike protein exacerbated the preexisting lower immune responsiveness and higher inflammatory potential in adults. Altogether, some of the markers identified may explain the marked age bias and be predictive of severity

A Granulocytic Signature Identifies COVID-19 and Its Severity

International audienceBackground An unbiased approach to SARS-CoV-2–induced immune dysregulation has not been undertaken so far. We aimed to identify previously unreported immune markers able to discriminate COVID-19 patients from healthy controls and to predict mild and severe disease.Methods An observational, prospective, multicentric study was conducted in patients with confirmed mild/moderate (n = 7) and severe (n = 19) COVID-19. Immunophenotyping of whole-blood leukocytes was performed in patients upon hospital ward or intensive care unit admission and in healthy controls (n = 25). Clinically relevant associations were identified through unsupervised analysis.Results Granulocytic (neutrophil, eosinophil, and basophil) markers were enriched during COVID-19 and discriminated between patients with mild and severe disease. Increased counts of CD15+CD16+ neutrophils, decreased granulocytic expression of integrin CD11b, and Th2-related CRTH2 downregulation in eosinophils and basophils established a COVID-19 signature. Severity was associated with emergence of PD-L1 checkpoint expression in basophils and eosinophils. This granulocytic signature was accompanied by monocyte and lymphocyte immunoparalysis. Correlation with validated clinical scores supported pathophysiological relevance.Conclusions Phenotypic markers of circulating granulocytes are strong discriminators between infected and uninfected individuals as well as between severity stages. COVID-19 alters the frequency and functional phenotypes of granulocyte subsets with emergence of CRTH2 as a disease biomarker

Sharing health big data for research - A design by use cases: the INSHARE platform approach

International audienceSharing and exploiting efficiently Health Big Data (HBD) lead to tackle great challenges: data protection and governance taking into account legal, ethical and deontological aspects which enables a trust, transparent and win-to-win relationship between researchers, citizen and data providers. Lack of interoperability: data are compartmentalized and are so syntactically and semantically heterogeneous. Variable data quality with a great impact on data management and statistical analysis. The objective of the INSHARE project is to explore, through an experimental proof of concept, how recent technologies could overcome such issues. It aims at demonstrating the feasibility and the added value of an IT platform based on CDW, dedicated to collaborative HBD sharing for medical research. METHOD: The consortium includes 6 data providers: 2 academic hospitals, the SNIIRAM (the French national reimbursement database) and 3 national or regional registries. The platform is designed following a 3 steps approach: (1) to analyze use cases, needs and requirements (2). To define data sharing governance and secure access to the platform, (3) To define the platform specifications. RESULT: 3 use cases (healthcare trajectory analysis, epidemiologic registry enrichment, signal detection) were analyzed to design the platform. corresponding to 5 studies and using 11 data sources. The governance was derived from the SCANNER model and adapted to data sharing. As a result, the platform architecture integrates the following tools and services: Data repository and hosting, semantic integration services, data processing, aggregate computing, data quality and integrity monitoring, Id linking, Multisource query builder, Visualization and data export services, data governance, study management service and security including data watermarking.

Colloque national Ergonomie et handicaps moteurs

SIGLECNRS AR 12194 (1-4) / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

LE DISQUE DES SPORTS / Interviews et commentaires de Max FAVALELLI avec les voix de ; Aviation : Paul CODOS ; Motocyclisme : Pierre MONNERET ; Automobile : Louis CHIRON ; Equitation : Chevalier d'ORGEIX ; Escrime : Paul Christian d'ORIOLA ; Aviron : Jean SEPHERIADES ; Natation : Alban MINVILLE et Jean BOITEUX ; Tennis : Marcel BERNARD et Pierre DARMON ; Athlétisme : Marcel HANSENNE et Jules LADOUMEGUE ; Boxe : Georges CARPENTIER, Théo MEDINA et Jacques DUMESNIL ; Lutte : Henri DEGLANE ; Football : Raymond KOPA et Roger COURTOIS ; Basket-Ball : Robert BUSNEL ; Rugby : Gérard DUFAU ; Patinage : Jacqueline du BIEF ; Cyclisme : Toto GERARDIN et Louison BOBET. Interview de Marcel CERDAN extraite des archives de la R.T.F. / interviewer inconnu

[Interview]BnF-Partenariats, Collection sonore - BelieveContient une table des matière