74 research outputs found
Whole-Body Analysis of a Viral Infection: Vascular Endothelium is a Primary Target of Infectious Hematopoietic Necrosis Virus in Zebrafish Larvae
The progression of viral infections is notoriously difficult to follow in whole organisms. The small, transparent zebrafish larva constitutes a valuable system to study how pathogens spread. We describe here the course of infection of zebrafish early larvae with a heat-adapted variant of the Infectious Hematopoietic Necrosis Virus (IHNV), a rhabdovirus that represents an important threat to the salmonid culture industry. When incubated at 24°C, a permissive temperature for virus replication, larvae infected by intravenous injection died within three to four days. Macroscopic signs of infection followed a highly predictable course, with a slowdown then arrest of blood flow despite continuing heartbeat, followed by a loss of reactivity to touch and ultimately by death. Using whole-mount in situ hybridization, patterns of infection were imaged in whole larvae. The first infected cells were detectable as early as 6 hours post infection, and a steady increase in infected cell number and staining intensity occurred with time. Venous endothelium appeared as a primary target of infection, as could be confirmed in fli1:GFP transgenic larvae by live imaging and immunohistochemistry. Disruption of the first vessels took place before arrest of blood circulation, and hemorrhages could be observed in various places. Our data suggest that infection spread from the damaged vessels to underlying tissue. By shifting infected fish to a temperature of 28°C that is non-permissive for viral propagation, it was possible to establish when virus-generated damage became irreversible. This stage was reached many hours before any detectable induction of the host response. Zebrafish larvae infected with IHNV constitute a vertebrate model of an hemorrhagic viral disease. This tractable system will allow the in vivo dissection of host-virus interactions at the whole organism scale, a feature unrivalled by other vertebrate models
OVX033, a nucleocapsid-based vaccine candidate, provides broad-spectrum protection against SARS-CoV-2 variants in a hamster challenge model
Spike-based COVID-19 vaccines induce potent neutralizing antibodies but their efficacy against SARS-CoV-2 variants decreases. OVX033 is a recombinant protein composed of the full-length nucleocapsid (N) protein of SARS-CoV-2 genetically fused to oligoDOMÂź, a self-assembling domain which improves antigen immunogenicity. OVX033 including N as an antigenic target is proposed as new vaccine candidate providing broad-spectrum protection against sarbecoviruses. OVX033 demonstrated its ability to trigger cross-reactive T cell responses and cross-protection against three variants of SARS-CoV-2 (B.1 Europe, Delta B.1.617.2, and Omicron B.1.1.529) in a hamster challenge model, as evidenced by lower weight loss, lower lung viral loads, and reduced lung histopathological lesions
Genetic landscape of a large cohort of Primary Ovarian Insufficiency : New genes and pathways and implications for personalized medicine
Background Primary Ovarian Insufficiency (POI), a public health problem, affects 1-3.7% of women under 40 yield-ing infertility and a shorter lifespan. Most causes are unknown. Recently, genetic causes were identified, mostly in single families. We studied an unprecedented large cohort of POI to unravel its molecular pathophysiology.Methods 375 patients with 70 families were studied using targeted (88 genes) or whole exome sequencing with pathogenic/likely-pathogenic variant selection. Mitomycin-induced chromosome breakages were studied in patients' lymphocytes if necessary. Findings A high-yield of 29.3% supports a clinical genetic diagnosis of POI. In addition, we found strong evidence of pathogenicity for nine genes not previously related to a Mendelian phenotype or POI: ELAVL2, NLRP11, CENPE, SPATA33, CCDC150, CCDC185, including DNA repair genes: C17orf53(HROB), HELQ, SWI5 yielding high chromo-somal fragility. We confirmed the causal role of BRCA2, FANCM, BNC1, ERCC6, MSH4, BMPR1A, BMPR1B, BMPR2, ESR2, CAV1, SPIDR, RCBTB1 and ATG7 previously reported in isolated patients/families. In 8.5% of cases, POI is the only symptom of a multi-organ genetic disease. New pathways were identified: NF-kB, post-translational regulation, and mitophagy (mitochondrial autophagy), providing future therapeutic targets. Three new genes have been shown to affect the age of natural menopause supporting a genetic link.Interpretation We have developed high-performance genetic diagnostic of POI, dissecting the molecular pathogene-sis of POI and enabling personalized medicine to i) prevent/cure comorbidities for tumour/cancer susceptibility genes that could affect life-expectancy (37.4% of cases), or for genetically-revealed syndromic POI (8.5% of cases), ii) predict residual ovarian reserve (60.5% of cases). Genetic diagnosis could help to identify patients who may benefit from the promising in vitro activation-IVA technique in the near future, greatly improving its success in treating infertility.Funding Universite? Paris Saclay, Agence Nationale de Biome?decine.Copyright (c) 2022 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)Peer reviewe
Ăvaluation des Programmes de RĂ©ussite Educative (PRE)
Etude rĂ©alisĂ©e en partenariat avec la DEPP et le CGET â voir la page dĂ©diĂ©e au projetLes Programmes de rĂ©ussite Ă©ducative (PRE), instituĂ©s par la loi de cohĂ©sion sociale de 2005, constituent une politique ambitieuse de lutte contre lâinĂ©galitĂ© des chances Ă destination des enfants et des adolescents les plus en difficultĂ©. Ces programmes ont pour objectif dâapporter aux enfants des quartiers prioritaires de la politique de la ville un parcours individualisĂ© reposant sur une approche globale des difficultĂ©s rencontrĂ©es, en collaboration Ă©troite avec la famille (suivi social, mĂ©dical, activitĂ©s culturelles ou sportives, ateliers dâexpression ou encore diffĂ©rentes formes de soutien scolaire). Ils bĂ©nĂ©ficient Ă plus de 100 000 enfants.Lâanalyse dâimpact prĂ©sentĂ©e dans ce rapport repose sur la mise en place de deux enquĂȘtes dans une centaine dâĂ©coles (la premiĂšre Ă lâautomne 2012, la seconde au printemps 2014) auprĂšs dâenfants de CE1 et CM1, de leurs parents, de leur enseignant et des coordonnateurs PRE. Afin dâĂȘtre en mesure de documenter au mieux lâensemble des difficultĂ©s rencontrĂ©es par les enfants et leur famille, et les effets des PRE sur ces difficultĂ©s, les questionnaires balaient un grand nombre de champs, en multipliant les points de vue. Les enfants ont ainsi chacun rempli plusieurs questionnaires visant Ă mesurer leur qualitĂ© de vie ressentie, leur estime de soi, leur motivation scolaire, qui complĂštent les mesures de compĂ©tences cognitives Ă©valuĂ©es Ă travers des tests de mathĂ©matiques et de français. Les enseignants ont Ă©galement eu Ă Ă©valuer pour chaque enfant diffĂ©rentes compĂ©tences scolaires et attitudes face aux apprentissages, et ont Ă©tĂ© interrogĂ©s sur le contexte familial des enfants. Les parents ont Ă©galement Ă©tĂ© interrogĂ©s sur leurs relations avec lâĂ©cole et la situation de leur enfant.Nous mesurons lâimpact des PRE en comparant lâĂ©volution de 404 enfants bĂ©nĂ©ficiaires dâun parcours entre lâautomne 2012 et le printemps 2014 Ă celle de 290 enfants ayant au dĂ©part des caractĂ©ristiques comparables sur les nombreuses dimensions mesurĂ©es, mais ne bĂ©nĂ©ficiant pas dâun parcours, parce que leur Ă©cole nâest pas en lien avec un PRE.Ainsi, le bien-ĂȘtre psychologique et le comportement des enfants ne semblent pas ĂȘtre amĂ©liorĂ©s par la prise en charge en PRE, et dâautres dimensions capturant les relations aux autres (estime de soi sociale, problĂšmes avec dâautres enfants) se dĂ©gradent mĂȘme lĂ©gĂšrement pour les enfants en parcours relativement aux enfants de caractĂ©ristiques semblables. Sur le plan scolaire, les Ă©lĂšves bĂ©nĂ©ficiaires dâun parcours connaissent Ă©galement une Ă©volution lĂ©gĂšrement moins favorable dans certaines dimensions de la motivation pour lâĂ©cole, mais leurs compĂ©tences objectives en mathĂ©matiques et français Ă©voluent de maniĂšre similaire aux autres enfants que nous avons suivis, et ils sont plus assidus. Les parents dâĂ©lĂšves bĂ©nĂ©ficiaires ne connaissent pas dâĂ©volution spĂ©cifique, tant dans leur relation Ă lâĂ©cole que dans leur perception de lâaccĂšs aux services sanitaires et sociaux. Au final, il nâexiste pas, dans nos donnĂ©es, dâindice permettant de dĂ©montrer que les PRE ont, en moyenne, fait progresser, sur le plan cognitif et non-cognitif, les enfants bĂ©nĂ©ficiaires davantage que des enfants non-bĂ©nĂ©ficiaires aux difficultĂ©s de dĂ©part trĂšs comparables. Cependant, nous ne sommes pas capables statistiquement de distinguer des effets potentiellement diffĂ©rents dans des sous-populations dâenfants.Pour comprendre ce rĂ©sultat, il faut souligner que les PRE offrent un accompagnement aux familles, mais sâappuient largement sur les ressources du droit commun. Or, les effets sur les enfants que nous estimons sont, in fine, les effets de la somme des actions dans lesquelles les enfants ont Ă©tĂ© effectivement engagĂ©s. Ces actions sont souvent des activitĂ©s sportives, des sĂ©jours en centres de loisir, du soutien scolaire, bref des actions offertes sur le territoire par diffĂ©rents acteurs, mais qui nâont pas Ă©tĂ© dĂ©veloppĂ©es spĂ©cifiquement en vue de ce public en grande difficultĂ©, et qui ne sont pas nĂ©cessairement trĂšs intensives. La recherche a dĂ©montrĂ© les effets jusquâĂ lâĂąge adulte de programmes Ă©trangers comparables dans leur philosophie, mais plus coĂ»teux, plus prĂ©coces, et qui construisent eux-mĂȘmes les actions concrĂštes dont bĂ©nĂ©ficient les enfants, et les y exposent de façon trĂšs intensive. Pour ĂȘtre plus efficaces face aux dĂ©fis immenses prĂ©sentĂ©s par les enfants dans des situations sociales trĂšs difficiles, les PRE devraient donc peut-ĂȘtre disposer des moyens de dĂ©ployer beaucoup plus souvent leurs propres interventions, et cibler davantage les enfants dâĂąge prĂ©scolaire
Alteration of the Fetal Heart Rate Pattern Induced by the Use Of Clozapine during Pregnancy
Patients treated with clozapine show autonomic dysregulation and cardiac repolarisation
changes. As clozapine crosses the placenta, it could have an impact on the fetus heart
rate. We reported a case of reduction of the fetal heart rate variability in a patient
treated with clozapine during her pregnancy. This anomaly disappeared with fetal
maturation and it did not jeopardize the fetal well-being. This side effect had already
been described and pharmacologists and obstetricians should be aware that clozapine may be
responsible for these fetal heart rate alterations
Lâargan, lâhuile qui cache la forĂȘt domestique: de la valorisation du produit Ă la naturalisation de lâĂ©cosystĂšme
Texte intĂ©gral accessible Ă partir de cairn.infoNational audienceDenrĂ©e prisĂ©e par des grands cuisiniers ou composant de cosmĂ©tiques de luxe, lâhuile dâargan marocaine prĂ©sentĂ©e commercialement comme un produit fabriquĂ© par les femmes, issue dâun arbre forestier et de pratiques purement sylvicoles, suscite depuis quelques annĂ©es un intĂ©rĂȘt soudain de la part de divers marchĂ©s. Cependant, malgrĂ© la cĂ©lĂ©britĂ© de cette huile, vague est la reprĂ©sentation que se font les consommateurs de son origine, hormis lâimage dâĂpinal dâun arbre Ă chĂšvre endĂ©mique au Maroc, lâarganier (argania spinosa), dont les fruits Ă noix donnent une huile aux vertus miraculeuses. Ă lâaube de la crĂ©ation dâune appellation dâorigine sur lâhuile dâargan, une rĂ©flexion scientifique ayant pour objet de cerner lâimpact sur les pratiques et savoirs locaux provoquĂ© par lâexplosion du marchĂ© de lâhuile dâargan et par la multiplication des acteurs de dĂ©veloppement dans la « zone arganeraie » semble sâimposer. Ă partir de lâexemple des politiques de valorisation de la filiĂšre huile dâargan, cette article dĂ©montre lâexistence dâun processus de naturalisation des Ă©cosystĂšmes, dâabord symbolique puis pratique, engendrĂ© par lâaction des dĂ©veloppeu
Assessment of amyloglucosidase activity during production and storage of laminated pie dough. Impact on raw dough properties and sweetness after baking
International audienc
Comparative Analysis of Culture Conditions for the Optimization of Carotenoid Production in Several Strains of the Picoeukaryote Ostreococcus
International audienceMicroalgae are promising sources for the sustainable production of compounds of interest for biotechnologies. Compared to higher plants, microalgae have a faster growth rate and can be grown in industrial photobioreactors. The microalgae biomass contains specific metabolites of high added value for biotechnology such as lipids, polysaccharides or carotenoid pigments. Studying carotenogenesis is important for deciphering the mechanisms of adaptation to stress tolerance as well as for biotechnological production. In recent years, the picoeukaryote Ostreococcus tauri has emerged as a model organism thanks to the development of powerful genetic tools. Several strains of Ostreococcus isolated from different environments have been characterized with respect to light response or iron requirement. We have compared the carotenoid contents and growth rates of strains of Ostreococcus (OTTH595, RCC802 and RCC809) under a wide range of light, salinity and temperature conditions. Carotenoid profiles and productivities varied in a strain-specific and stress-dependent manner. Our results also illustrate that phylogenetically related microalgal strains originating from different ecological niches present specific interests for the production of specific molecules under controlled culture conditions
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