20 research outputs found

    Requirement of NOX2 and Reactive Oxygen Species for Efficient RIG-I-Mediated Antiviral Response through Regulation of MAVS Expression

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    The innate immune response is essential to the host defense against viruses, through restriction of virus replication and coordination of the adaptive immune response. Induction of antiviral genes is a tightly regulated process initiated mainly through sensing of invading virus nucleic acids in the cytoplasm by RIG-I like helicases, RIG-I or Mda5, which transmit the signal through a common mitochondria-associated adaptor, MAVS. Although major breakthroughs have recently been made, much remains unknown about the mechanisms that translate virus recognition into antiviral genes expression. Beside the reputed detrimental role, reactive oxygen species (ROS) act as modulators of cellular signaling and gene regulation. NADPH oxidase (NOX) enzymes are a main source of deliberate cellular ROS production. Here, we found that NOX2 and ROS are required for the host cell to trigger an efficient RIG-I-mediated IRF-3 activation and downstream antiviral IFNÎČ and IFIT1 gene expression. Additionally, we provide evidence that NOX2 is critical for the expression of the central mitochondria-associated adaptor MAVS. Taken together these data reveal a new facet to the regulation of the innate host defense against viruses through the identification of an unrecognized role of NOX2 and ROS

    Profil de la cardiomyopathie du péripartum au Centre Hospitalier Universitaire de Libreville

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    La cardiomyopathie du pĂ©ripartum (CMP-PP) est une cause rare d’insuffisance cardiaque (IC) de la femme en pĂ©riode d’activitĂ© gĂ©nitale. L’objectif de cette Ă©tude Ă©tait d’en dĂ©terminer les profils cliniques de la maladie chez des parturientes au Gabon. Il s’est agi d’une analyse rĂ©trospective rĂ©alisĂ©e de janvier 2012 Ă  janvier 2016 au Centre Hospitalier Universitaire de Libreville. Une CMP-PP a Ă©tĂ© diagnostiquĂ©e chez 27 patientes avec un Ăąge moyen de 27,1 ± 5,5 ans. L’IC Ă©tait globale dans 59,2 % des cas et survenait chez 92,6 % des patientes dans le post-partum. La dyspnĂ©e Ă©tait le symptĂŽme initial dans 100 % des cas, d’installation progressive chez 9 (33.3 %) patientes, avec un dĂ©lai moyen d’apparition de 29,4 ± 35 jours. La plupart des patientes Ă©taient des multipares (74,1 %), avaient un niveau socio-Ă©conomique faible (48,1 %) et avaient une prĂ©-Ă©clampsie (48,1 %). Un diamĂštre tĂ©lĂ©diastolique moyen du ventricule gauche supĂ©rieur Ă  60 mm Ă©tait retrouvĂ© chez 17 (62,9 %) patientes et une fraction d’éjection ventriculaire gauche infĂ©rieure Ă  30 % chez 14 (51,8 %) d’entre elles. A Libreville, la CMP-PP affecte des patientes jeunes et les lĂ©sions initiales sont sĂ©vĂšres.Mots-clĂ©s: CMP-PP, clinique, risque, pronostic, LibrevilleEnglish Title: Profile of peripartum cardiomyopathy at the University Hospital Center of LibrevilleEnglish AbstractPost-partum cardiomyopathy (PPCMP) is a rare heart failure aetiology in women in genital activity. The aim of this study was to describe the clinical patterns and to determine the associated risk and poor prognostic factors. This was a retrospective analysis performed at the Centre Hospitalier Universitaire de Libreville with patient files hospitalized from January 2012 to December 2016. PPCMP was diagnosed in 27patients.There mean age was 27,1 ± 5,5 years . Global heart failure was the most frequent presentation (59,2%) and appeared during the post-partum period in 92,6% of cases. Dyspnea was always present at the onset of the disease and progressive in 9 (33.3%) patients. The mean duration of symptom apparition was 29,4 ± 34,9 days. Patients had multiple pregnancy (74,1%), pre-eclampsia (48,1%) and low socio-economic level (48,1%). A left ventricular dilatation higher than 60mm (62,9%) and left ventricular ejection fraction lower than 30% (51,8%) were strong prognostic factors. PPCMP affected young people with severe initial lesions.Keywords: PPCMP, clinical presentation, risk, pronostic, Librevill

    Essai de lutte intégrée contre la prolifération de Cissus quadrangularis L. (Vitaceae) dans le Parc National des Iles de la Madeleine (Sénégal)

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    Objectif : contribuer Ă  mettre en place une lutte intĂ©grĂ©e contre la prolifĂ©ration de Cissus quadrangularis L. dans le Parc National des Iles de la Madeleine (PNIM) au SĂ©nĂ©gal.MĂ©thodologie et rĂ©sultats : Des essais de contrĂŽle biologique et physique ont Ă©tĂ© testĂ©s. La lutte biologique a Ă©tĂ© basĂ©e sur la collecte et l’élevage en laboratoire de chenilles capables de dĂ©grader les tiges et les feuilles de C. quadrangularis. Quant Ă  la lutte physique, elle a consistĂ© Ă  arracher les individus de l’espĂšce et Ă  suivre la capacitĂ© de rĂ©gĂ©nĂ©ration des rĂ©sidus de la plante aprĂšs diffĂ©rents traitements. Les rĂ©sultats obtenus ont montrĂ© qu’une lutte biologique est envisageable Ă  travers la chenille de   Hippotion celerio, phytophage de C. quadrangularis. Aussi, les tests de contrĂŽle physique ont montrĂ© que l’arrachage manue  semblerait ĂȘtre efficace quand les fragments de la plante sont Ă©liminĂ©s par  incinĂ©ration hors du parc.Conclusion et application: La combinaison de ces deux mĂ©thodes pourrait permettre de rĂ©duire et de limiter la superficie d’occupation de C. quadrangularis dans le PNIM.Mots clĂ©s: Cissus quadrangularis, plante prolifĂ©rante, Parc National des Iles de la Madeleine, lutte physique, lutte biologique, Hippotion celerio.Introduction: Help put up a integrated fight against the proliferation of Cissus quadrangularis L. in the National Park des Iles de la Madeleine (NPIM) in Senegal.Methodology and results: of trying to biological and physical control. Biological control has been based on collecting and raising caterpillars capable of degrading the stems and leaves of the concern species. As for the physical struggle, it was to snatch individuals of C. quadrangularis and follow the regenerative capacity of the plant residues after different treatments. The results have shown that biological control is possible through the caterpillar of Hippotion celerio, phytophage of C. quadrangularis. Also, physical control tests have shown that manual eradication would seem to be effective when the fragments of the plant are disposed of by incineration out of the park.Conclusion and application: The combination of these two methods could reduce and limit the occupancy area and possible spread of C. quadrangularis in NPIM.Keywords: Cissus quadrangularis, Alien plants, National Park des Iles de la Madeleine, physical control, biological control, Hippotion celerio

    Lutte contre la rage en Afrique: du constat à l’action

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    International audienceAs a follow-up to the first AfroREB (Africa Rabies Expert Bureau) meeting, held in Grand-Bassam (CĂŽte-d'Ivoire) in March 2008, African rabies experts of the Afro-REB network met a second time to complete the evaluation of the rabies situation in Africa and define specific action plans. About forty French speaking rabies specialists from Northern, Western and Central Africa and Madagascar met in Dakar (Senegal), from March 16th to 19th, 2009. With the participation of delegates from Tunisia, who joined the AfroREB network this year, 15 French speaking African countries were represented. Experts from the Institut Pasteur in Paris, the Alliance for Rabies Control, and the Southern and Eastern African Rabies Group (SEARG, a network of rabies experts from 19 English speaking Southern and Eastern African countries) were in attendance, to participate in the discussion and share their experiences. AfroREB members documented 146 known human rabies cases in all represented countries combined for 2008, for a total population of 209.3 million, or an incidence of 0.07 cases per 100,000 people. Even admitting that the experts do not have access to all reported cases, this is far from the WHO estimation of 2 rabies deaths per 100,000 people in urban areas and 3.6 per 100,000 in rural Africa. It was unanimously agreed that the priority is to break the vicious cycle of indifference and lack of information which is the main barrier to human rabies prevention.Le Bureau des experts de la rage du continent africain (AfroREB) s’est rĂ©uni pour la seconde fois, en mars 2009, pour poursuivre leur Ă©valuation de la situation de la rage en Afrique et dĂ©finir des plans d’action. Une quarantaine d’éminents spĂ©cialistes de la rage venant de 15 pays d’Afrique francophone se sont retrouvĂ©s Ă  Dakar avec des reprĂ©sentants de l’Institut Pasteur de Paris, du rĂ©seau anglophone SEARG (groupe de spĂ©cialistes de la rage d’Afrique australe et orientale) et de l’Alliance mondiale contre la rage. En Afrique, de nombreux cas de rage ne sont ni identifiĂ©s ni rapportĂ©s. Alors que l’OMS estime Ă  25 000 le nombre de dĂ©cĂšs annuels dus Ă  la rage sur ce continent (2 Ă  3,6 dĂ©cĂšs pour 100 000 habitants), les membres d’AfroREB ont comptabilisĂ©, en tout et pour tout, en 2008, 146 cas pour leurs 15 pays, soit 0,07 cas pour 100 000 habitants. La prioritĂ© est de briser le cercle vicieux de l’indiffĂ©rence et du manque d’information, afin de pouvoir lutter contre la rage humaine
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