80 research outputs found

    lpxC and yafS are the Most Suitable Internal Controls to Normalize Real Time RT-qPCR Expression in the Phytopathogenic Bacteria Dickeya dadantii

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    Background: Quantitative RT-PCR is the method of choice for studying, with both sensitivity and accuracy, the expression of genes. A reliable normalization of the data, using several reference genes, is critical for an accurate quantification of gene expression. Here, we propose a set of reference genes, of the phytopathogenic bacteria Dickeya dadantii and Pectobacterium atrosepticum, which are stable in a wide range of growth conditions. [br/] Results: We extracted, from a D. dadantii micro-array transcript profile dataset comprising thirty-two different growth conditions, an initial set of 49 expressed genes with very low variation in gene expression. Out of these, we retained 10 genes representing different functional categories, different levels of expression (low, medium, and high) and with no systematic variation in expression correlating with growth conditions. We measured the expression of these reference gene candidates using quantitative RT-PCR in 50 different experimental conditions, mimicking the environment encountered by the bacteria in their host and directly during the infection process in planta. The two most stable genes (ABF-0017965 (lpxC) and ABF-0020529 (yafS) were successfully used for normalization of RT-qPCR data. Finally, we demonstrated that the ortholog of lpxC and yafS in Pectobacterium atrosepticum also showed stable expression in diverse growth conditions. [br/] Conclusions: We have identified at least two genes, lpxC (ABF-0017965) and yafS (ABF-0020509), whose expressions are stable in a wide range of growth conditions and during infection. Thus, these genes are considered suitable for use as reference genes for the normalization of real-time RT-qPCR data of the two main pectinolytic phytopathogenic bacteria D. dadantii and P. atrosepticum and, probably, of other Enterobacteriaceae. Moreover, we defined general criteria to select good reference genes in bacteria

    N-Acyl Homoserine Lactones in Diverse Pectobacterium and Dickeya Plant Pathogens: Diversity, Abundance, and Involvement in Virulence

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    Soft-rot bacteria Pectobacterium and Dickeya use N-acyl homoserine lactones (NAHSLs) as diffusible signals for coordinating quorum sensing communication. The production of NAHSLs was investigated in a set of reference strains and recently-collected isolates, which belong to six species and share the ability to infect the potato host plant. All the pathogens produced different NAHSLs, among which the 3-oxo-hexanoyl- and the 3-oxo-octanoyl-l-homoserine lactones represent at least 90% of total produced NAHSL-amounts. The level of NAHSLs varied from 0.6 to 2 pg/cfu. The involvement of NAHSLs in tuber maceration was investigated by electroporating a quorum quenching vector in each of the bacterial pathogen strains. All the NAHSL-lactonase expressing strains produced a lower amount of NAHSLs as compared to those harboring the empty vector. Moreover, all except Dickeya dadantii 3937 induced a lower level of symptoms in potato tuber assay. Noticeably, aggressiveness appeared to be independent of both nature and amount of produced signals. This work highlights that quorum sensing similarly contributed to virulence in most of the tested Pectobacterium and Dickeya, even the strains had been isolated recently or during the past decades. Thus, these key regulatory-molecules appear as credible targets for developing anti-virulence strategies against these plant pathogens

    Gaining Greater Insight into HCV Emergence in HIV-Infected Men Who Have Sex with Men: The HEPAIG Study

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    OBJECTIVES: The HEPAIG study was conducted to better understand Hepatitis C virus (HCV) transmission among human immuno-deficiency (HIV)-infected men who have sex with men (MSM) and assess incidence of HCV infection among this population in France. METHODS AND RESULTS: Acute HCV infection defined by anti-HCV or HCV ribonucleic acid (RNA) positivity within one year of documented anti-HCV negativity was notified among HIV-infected MSM followed up in HIV/AIDS clinics from a nationwide sampling frame. HIV and HCV infection characteristics, HCV potential exposures and sexual behaviour were collected by the physicians and via self-administered questionnaires. Phylogenetic analysis of the HCV-NS5B region was conducted. HCV incidence was 48/10 000 [95% Confidence Interval (CI):43-54] and 36/10 000 [95% CI: 30-42] in 2006 and 2007, respectively. Among the 80 men enrolled (median age: 40 years), 55% were HIV-diagnosed before 2000, 56% had at least one sexually transmitted infection in the year before HCV diagnosis; 55% were HCV-infected with genotype 4 (15 men in one 4d-cluster), 32.5% with genotype 1 (three 1a-clusters); five men were HCV re-infected; in the six-month preceding HCV diagnosis, 92% reported having casual sexual partners sought online (75.5%) and at sex venues (79%), unprotected anal sex (90%) and fisting (65%); using recreational drugs (62%) and bleeding during sex (55%). CONCLUSIONS: This study emphasizes the role of multiple unprotected sexual practices and recreational drugs use during sex in the HCV emergence in HIV-infected MSM. It becomes essential to adapt prevention strategies and inform HIV-infected MSM with recent acute HCV infection on risk of re-infection and on risk-reduction strategies

    Long-term effects of evolocumab in participants with HIV and dyslipidemia: results from the open-label extension period

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    Objectives: People with HIV (PWH) are at an increased risk of atherosclerotic cardiovascular disease. Suboptimal responses to statin therapy in PWH may result from antiretroviral therapies (ARTs). This open-label extension study aimed to evaluate the long-term safety and efficacy of evolocumab up to 52\u200aweeks in PWH. Design: This final analysis of a multinational, placebo-controlled, double-blind, randomized phase 3 trial evaluated the effect of monthly subcutaneous evolocumab 420\u200amg on low-density lipoprotein cholesterol (LDL-C) during the open-label period (OLP) following 24\u200aweeks of double-blind period in PWH with hypercholesterolemia/mixed dyslipidemia. All participants enrolled had elevated LDL-C or nonhigh-density lipoprotein cholesterol (non-HDL-C) and were on stable maximally tolerated statin and stable ART. Methods: Efficacy was assessed by percentage change from baseline in LDL-C, triglycerides, and atherogenic lipoproteins. Treatment-emergent adverse events (TEAEs) were examined. Results: Of the 467 participants randomized in the double-blind period, 451 (96.6%) received at least one dose of evolocumab during the OLP (mean age of 56.4\u200ayears, 82.5% male, mean duration with HIV of 17.4\u200ayears). By the end of the 52-week OLP, the overall mean (SD) percentage change in LDL-C from baseline was -57.8% (22.8%). Evolocumab also reduced triglycerides, atherogenic lipid parameters (non-HDL-C, apolipoprotein B, total cholesterol, very-low-density lipoprotein cholesterol, and lipoprotein[a]), and increased HDL-C. TEAEs were similar between placebo and evolocumab during the OLP. Conclusion: Long-term administration of evolocumab lowered LDL-C and non-HDL-C, allowing more PWH to achieve recommended lipid goals with no serious adverse events. Trail registration: NCT02833844. Video abstract: http://links.lww.com/QAD/C441

    Atomic spectrometry update – a review of advances in environmental analysis

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    La substantivation des adjectifs en anglais contemporain

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    NOTRE PROJET EST DE PROPOSER UNE TYPOLOGIE SEMANTICO-REFERENTIELLE DES ADJECTIFS SUBSTANTIVES (AS) EN ANGLAIS CONTEMPORAIN. NOTRE POINT DE DEPART EST LA CONSCIENCE QUE LA SUBSTANTIVATION EST UN PHENOMENE DE RESTRUCTURATION ET DE CONDENSATION SYNTAXIQUE, ABOUTISSANT PARFOIS A UNE LEXICALISATION. NOTRE DEMARCHE A ETE DE MENER UNE ETUDE DE CORPUS EN CONTEXTE: UNE ANALYSE MORPHOSYNTAXIQUE DES PHENOMENES DE SURFACE DE L'ENONCE, C'EST-A-DIRE LA COMPOSITION DU SYNTAGME CONTENANT L'AS (DETERMINANTS, MODIFIEURS, COMPLEMENTS, ETC.) A LAQUELLE S'EST AJOUTEE UNE ANALYSE SEMANTIQUE S'INTERESSANT AU MODE DE RESTITUTION DE LA REFERENCE DES AS. NOUS AVONS MIS EN EVIDENCE LE PARCOURS INTERPRETATIF DECLENCHE PAR L'EMPLOI DES AS, ET OBSERVE LE ROLE DE LA FLEXION DU PLURIEL DANS LA DENSIFICATION DU SENS. L'ASSOCIATION DES DEUX NIVEAUX D'ANALYSE NOUS PERMET DE PROPOSER UN MODELE GLOBAL DES ADJECTIFS SUBSTANTIVES EN TERMES DE MODES DE CATEGORISATION DU REEL. LA RICHESSE SEMANTIQUE DES AS, L'EXPRESSIVITE ET LA CREATIITE QUI S'EN DEGAGENT EN FONT UN OBJET D'ETUDE MULTIDISCIPLINAIRE.THE PURPOSE OF OUR STUDY IS TO OFFER A TYPOLOGY OF SUBSTANTIVIZED ADJECTIVES IN CONTEMPORARY ENGLISH. OUR APPROACH IS BOTH A MORPHOSYNTACTIC AND A SEMANTIC ONE. IN THE ABSENCE OF ANY COMPREHENSIVE RESEARCH IN THIS FIELD, WE HAVE COMPILED THE VARIOUS APPROACHES TO THE ABSENCE OF A HEAD-NOUN IN A NOUN PHRASE, INCLUDING FUSION, ELLIPSIS AND SUBSTANTIVIZATION AND HAVE CONCLUDED THAT SUBSTANTIVIZATION IS ABOVE ALL A SYNTACTIC PHENOMENON WITH SEMANTIC REPERCUSSIONS IN TERMS OF CATEGORIZATION AND THE REPRSENTATION OF EXPERIENCES. THE LEXICAL APPROACH OF SUBSTANTIVIZED ADJECTIVES IS MERELY THE TIP OF THE ICEBERG. OUR IN-DEPTH ANALYSIS HAS ENABLED US TO DETAIL THEIR MULTIPLE MEANING, THEIR EXPRESSIVE AND CREATIVE COMPONENTS, GIVING US A BASIS FOR A PROGRESSIVE TYPOLOGY OF SUBSTANTIVIZED ADJECTIVES IN TERMS OF THE AUTONOMY OF THE CATEGORIZATION.PARIS4-BU Serpente (751052129) / SudocSudocFranceF

    Fatty Acid Hydroperoxides and H(2)O(2) in the Execution of Hypersensitive Cell Death in Tobacco Leaves

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    We initially compared lipid peroxidation profiles in tobacco (Nicotiana tabacum) leaves during different cell death events. An upstream oxylipin assay was used to discriminate reactive oxygen species (ROS)-mediated lipid peroxidation from 9- and 13-lipoxygenase (LOX)-dependent lipid peroxidation. Free radical-mediated membrane peroxidation was measured during H(2)O(2)-dependent cell death in leaves of catalase-deficient plants. Taking advantage of these transgenic plants, we demonstrate that, under light conditions, H(2)O(2) plays an essential role in the execution of cell death triggered by an elicitor, cryptogein, which provokes a similar ROS-mediated lipid peroxidation. Under dark conditions, however, cell death induction by cryptogein was independent of H(2)O(2) and accompanied by products of the 9-LOX pathway. In the hypersensitive response induced by the avirulent pathogen Pseudomonas syringae pv syringae, both 9-LOX and oxidative processes operated concurrently, with ROS-mediated lipid peroxidation prevailing in the light. Our results demonstrate, therefore, the tight interplay between H(2)O(2) and lipid hydroperoxides and underscore the importance of light during the hypersensitive response

    Distribution of the right-lateral strike-slip motion from the Main Recent Fault to the Kazerun Fault System (Zagros, Iran): Evidence from present-day GPS velocities

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    International audienceGPS measurements across the Kazerun Fault System in the Zagros mountain belt provide first instantaneous velocities on the different segments. These results are closely consistent with the geological fault slip rates (over 150 ka), implying stable velocities over a longer period. The present-day strike-slip motion is distributed from the Main Recent Fault to the N-trending Kazerun Fault System along a preferential en-echelon fault zone included in a more distributed fan-shape fault pattern. The Hormuz salt decoupling layer cannot be the only cause of a sedimentary spreading because seismicity attests these faults are rooted in the basement. The Dena fault (3.7 mm/yr) transfers the MRF fault slip mainly to the Kazerun (3.6 mm/yr) and slightly to the High Zagros and Sabz Pushan faults (1.5 mm/yr), and the Kazerun fault further to the Kareh Bas fault (3.4 mm/yr). Total geological horizontal offsets associated with GPS slip rates help inferring precise fault slip onset ages. The successive onsets deduced by this approach imply that the right-lateral strike-slip activity of the MRF has propagated in time southeastward to the Dena segment, and then to the Kazerun segment and to the Kareh Bas fault

    Perception of antiretroviral generic medicines: one-day survey of HIV-infected patients and their physicians in France.

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    BACKGROUND:In the interest of cost effectiveness, switching antiretroviral brand name medications to generics is recommended in France since 2013. The study objective was to evaluate the perception of generics per se and antiretroviral generics in HIV-infected patients and their hospital physicians. METHODS AND FINDINGS:556 out of 703 (79%) adult HIV+ outpatients and 116 physicians in 33 clinics were included in a multicentric cross-sectional survey performed in September 2013. Patients completed a self-questionnaire on their perception and acceptability of generics. Physicians completed a questionnaire on their acceptability of switching antiretroviral to generic. Socio-demographic data, medical history and HIV history were collected. Among the 556 patients with a median HIV duration of 13 years, 77% were France native, 59% in active employment, 100% covered by social insurance, 95% on antiretroviral therapy. Seventy-six percent of the patients accepted generics and 55% trusted them overall. Antiretroviral generics were accepted by 44% of them but only by 17% if the pill burden was going to increase. The factor significantly associated with acceptability of antiretroviral generics was acceptance of generics per se (p<0.001). Among the 116 physicians following a median of 100 HIV-patients/year, 75% would prescribe generics, dropping to 26% if the combo had to be broken. Factors significantly associated with willingness to prescribe antiretroviral generics were the absence of concern regarding the chemical entity (OR = 0.33), being aware that the patient would accept generics for other pathologies (OR = 2.04) and would accept antiretroviral generics (OR = 1.94). No factor related to sociodemographic conditions, HIV status or comorbidities was associated with the acceptability of antiretroviral generics. CONCLUSIONS:Acceptability of antiretroviral generics in this French population was mostly dictated by the patient's and physician's knowledge and use of generics overall. It should be improved with an efficient information of both patients and physicians
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