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Search Results: 1 - 10 of 4226 matches for " Valérie Briolat "
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Origin and Evolution of TRIM Proteins: New Insights from the Complete TRIM Repertoire of Zebrafish and Pufferfish
Pierre Boudinot, Lieke M. van der Aa, Luc Jouneau, Louis Du Pasquier, Pierre Pontarotti, Valérie Briolat, Abdenour Benmansour, Jean-Pierre Levraud
PLOS ONE , 2011, DOI: 10.1371/journal.pone.0022022
Abstract: Tripartite motif proteins (TRIM) constitute a large family of proteins containing a RING-Bbox-Coiled Coil motif followed by different C-terminal domains. Involved in ubiquitination, TRIM proteins participate in many cellular processes including antiviral immunity. The TRIM family is ancient and has been greatly diversified in vertebrates and especially in fish. We analyzed the complete sets of trim genes of the large zebrafish genome and of the compact pufferfish genome. Both contain three large multigene subsets - adding the hsl5/trim35-like genes (hltr) to the ftr and the btr that we previously described - all containing a B30.2 domain that evolved under positive selection. These subsets are conserved among teleosts. By contrast, most human trim genes of the other classes have only one or two orthologues in fish. Loss or gain of C-terminal exons generated proteins with different domain organizations; either by the deletion of the ancestral domain or, remarkably, by the acquisition of a new C-terminal domain. Our survey of fish trim genes in fish identifies subsets with different evolutionary dynamics. trims encoding RBCC-B30.2 proteins show the same evolutionary trends in fish and tetrapods: they evolve fast, often under positive selection, and they duplicate to create multigenic families. We could identify new combinations of domains, which epitomize how new trim classes appear by domain insertion or exon shuffling. Notably, we found that a cyclophilin-A domain replaces the B30.2 domain of a zebrafish fintrim gene, as reported in the macaque and owl monkey antiretroviral TRIM5α. Finally, trim genes encoding RBCC-B30.2 proteins are preferentially located in the vicinity of MHC or MHC gene paralogues, which suggests that such trim genes may have been part of the ancestral MHC.
Whole-Body Analysis of a Viral Infection: Vascular Endothelium is a Primary Target of Infectious Hematopoietic Necrosis Virus in Zebrafish Larvae
Marion Ludwig equal contributor,Nuno Palha equal contributor,Corinne Torhy,Valérie Briolat,Emma Colucci-Guyon,Michel Brémont,Philippe Herbomel,Pierre Boudinot,Jean-Pierre Levraud
PLOS Pathogens , 2011, DOI: 10.1371/journal.ppat.1001269
Abstract: 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.
A large new subset of TRIM genes highly diversified by duplication and positive selection in teleost fish
Lieke M van der Aa, Jean-Pierre Levraud, Malika Yahmi, Emilie Lauret, Valérie Briolat, Philippe Herbomel, Abdenour Benmansour, Pierre Boudinot
BMC Biology , 2009, DOI: 10.1186/1741-7007-7-7
Abstract: We describe here a large new subfamily of TRIMs in teleosts, called finTRIMs, identified in rainbow trout as virus-induced transcripts. FinTRIMs are formed of nearly identical RING/B-box regions and C-termini of variable length; the long variants include a B30.2 domain. The zebrafish genome harbors a striking diversity of finTRIMs, with 84 genes distributed in clusters on different chromosomes. A phylogenetic analysis revealed different subsets suggesting lineage-specific diversification events. Accordingly, the number of fintrim genes varies greatly among fish species. Conserved syntenies were observed only for the oldest fintrims. The closest mammalian relatives are trim16 and trim25, but they are not true orthologs. The B30.2 domain of zebrafish finTRIMs evolved under strong positive selection. The positions under positive selection are remarkably congruent in finTRIMs and in mammalian antiviral TRIM5α, concentrated within a viral recognition motif in mammals. The B30.2 domains most closely related to finTRIM are found among NOD-like receptors (NLR), indicating that the evolution of TRIMs and NLRs was intertwined by exon shuffling.The diversity, evolution, and features of finTRIMs suggest an important role in fish innate immunity; this would make them the first TRIMs involved in immunity identified outside mammals.Newly discovered players in the antiviral immunity field are the proteins belonging to the tripartite motif (TRIM) family. The TRIM proteins are characterized by a tripartite motif that comprises from the N- to C-terminus, a RING zinc finger domain, one or two B-boxes and a coiled-coil domain. They are therefore also known as RBCC proteins [1]. The RING finger and B-box are cysteine-rich domains and both domains bind zinc atoms, suggesting interaction with other proteins, RNA and DNA [2-5]. They are usually encoded as a single exon, and together form the 'RBB' region. In addition, the RING finger has E3 ubiquitin ligase activity [6]. The coiled-coil reg
Real-Time Whole-Body Visualization of Chikungunya Virus Infection and Host Interferon Response in Zebrafish
Nuno Palha,Florence Guivel-Benhassine,Valérie Briolat,Georges Lutfalla,Marion Sourisseau,Felix Ellett,Chieh-Huei Wang,Graham J. Lieschke,Philippe Herbomel,Olivier Schwartz,Jean-Pierre Levraud
PLOS Pathogens , 2013, DOI: 10.1371/journal.ppat.1003619
Abstract: Chikungunya Virus (CHIKV), a re-emerging arbovirus that may cause severe disease, constitutes an important public health problem. Herein we describe a novel CHIKV infection model in zebrafish, where viral spread was live-imaged in the whole body up to cellular resolution. Infected cells emerged in various organs in one principal wave with a median appearance time of ~14 hours post infection. Timing of infected cell death was organ dependent, leading to a shift of CHIKV localization towards the brain. As in mammals, CHIKV infection triggered a strong type-I interferon (IFN) response, critical for survival. IFN was mainly expressed by neutrophils and hepatocytes. Cell type specific ablation experiments further demonstrated that neutrophils play a crucial, unexpected role in CHIKV containment. Altogether, our results show that the zebrafish represents a novel valuable model to dynamically visualize replication, pathogenesis and host responses to a human virus.
Neuroendocrine Differentiation in the Progression of Prostate Cancer: An Update on Recent Developments  [PDF]
Valérie Perrot
Open Journal of Urology (OJU) , 2012, DOI: 10.4236/oju.2012.223032
Abstract: Neuroendocrine (NE) differentiation, either benign or malignant, is the hallmark of prostate cancer (PCa). Clusters of malignant NE cells are found in most prostate cancer cases. NE differentiation is among the non-mutually exclusive theories proposed to explain the progression to androgen independence of PCa. NE differentiation is usually associated with an increased aggressivity and invasiveness of prostate tumors and a poor prognosis. This review aims to present an overview of current knowledge on neuroendocrine differentiation in PCa to improve our understanding of tumour progression and androgen independence. The NE component represents an important therapeutic axis. Development of new generation of drugs that selectively target NE-like cells may lead to the development of new therapeutic modalities for advanced and hormone-refractory PCa.
Bordetella holmesii: Comparison of Two Isolates from Blood and a Respiratory Sample  [PDF]
Valérie Bouchez, Nicole Guiso
Advances in Infectious Diseases (AID) , 2013, DOI: 10.4236/aid.2013.32020
Abstract:

Interest in Bordetella holmesii is increasing, but very little is known about this bacterium, which can be isolated from both blood and respiratory samples. In this study, we compared a B. holmesii isolate from the blood sample of an adult with bacteremia with another isolate from a nasopharyngeal swab from an adult with whooping cough syndrome. Genetic analysis was carried out, targeting relevant genes, and virulence properties were studied in cellular and animal models. Our genomic analysis provided no evidence of traits specific to either blood or respiratory isolates of B. holmesii. Neither isolate was cytotoxic to human tracheal epithelial cells. Both isolates were only weakly invasive and they did not persist within epithelial cells for less than 48 h.

Effect of Pulsed Ultraviolet Light on the Total Phenol Content of Elderberry (Sambucus nigra) Fruit  [PDF]
Ramesh Murugesan, Valérie Orsat, Mark Lefsrud
Food and Nutrition Sciences (FNS) , 2012, DOI: 10.4236/fns.2012.36104
Abstract: The changes in total polyphenolics in elderberry (Sambucus nigra) following treatment with various doses of pulsed ultraviolet rays (UV) were investigated. Four pulsed UV durations (5, 10, 20, 30 seconds) at three energy dosages (4500, 6000, 11,000 J/m2/pulse) were considered for the research. All treated elderberry fruits were incubated for 24 h at room temperature (25℃) following treatment to ensure enough response duration for enhanced development of polyphenols by the berries. The highest increase in total phenolics around 50% was found with 11,000 J/m2/pulse for a 10 seconds treatment while nearly 40% increase in total phenolics was found at an energy dosage of 11,000 J/m2/pulse after 5 seconds exposure. Even though most of the treatments indicated an increase in total polyphenols, some treatment expressed a decrease in phenolics content when compared to untreated fruits.
The Unconscious Experimentally Demonstrated by Means of Hypnosis  [PDF]
Edoardo Casiglia, Valérie Tikhonoff, Enrico Facco
Psychology (PSYCH) , 2016, DOI: 10.4236/psych.2016.74048
Abstract:

Although taken for granted today by people and by some experts, the unconscious has never been experimentally demonstrated. Even for the psychoanalysts, the unconscious is nothing more than a model. The unconscious, if anything, is normally obscured by conscious activities and can only express itself in response to conditions leading to non-ordinary mental expressions, for instance during hypnosis. For many years, we have been using hypnosis in variegating experimental setting, and we think one of the evidences coming from our tests is the experimental demonstration that the unconscious exists and can be forced to respond to solicitations the participant is not aware of. We administered hypnotic suggestions to highly-hypnotizable normal participants with the aim of inducing hallucination of body heating, alexia, amusia, spatial neglect, focused analgesia, general anaesthesia, and age regression. Following such suggestions, participants actually experienced a sensation of heat, incapability to read, lack of interest in a side of the world, indifference to painful stimuli, and revivification of infantile age, respectively. But this is not all. Through the above-mentioned suggestions we also obtained some physical reactions that could only be defined as unconscious, i.e. increase of the stroke volume and of the mesenteric artery flow following hallucinated body heating, reduction of reaction times to incongruent color words in a Stroop task following alexia, prolongation of ipsilateral reaction times following spatial neglect, reduction of mismatch negativity to deviant stimuli following hypnotic amusia, coherent modifications of the sympathetic/parasympathetic balance to trigeminal and non-trigeminal pain during analgesia and anaesthesia, reduction of Raven score and Raven-induced stress during age regression. These responses evoked during hypnosis in response to mental images are clearly non-voluntary and non-conscious, and demonstrate in experimental setting with the tools that are typical of human physiology—the existence of unconscious to perceive and react.

A Critical Evaluation of Single Extractions from the SMT Program to Determine Trace Element Mobility in Sediments
Valérie Cappuyns
Applied and Environmental Soil Science , 2012, DOI: 10.1155/2012/672914
Abstract: Two commonly applied single extractions procedures, namely extractions with ammonium-EDTA and acetic acid, were evaluated based on the analysis of 72 samples from alluvial sediments. For most trace elements (Cu, Zn, Cd, Ni, As, and Pb), a significant linear relationship could be established between their ammonium-EDTA or acetic acid extractable concentrations and their total concentrations, the organic carbon content, pH, and Fe , Al, and/or Ca content in the sediments. The scientific understanding of trace element partitioning in the complex soil-water system with these simple models is rather limited, but they offer the opportunity to use data from single extractions in a more comprehensive way. Despite the fact that these extractions cannot directly be related to the bioavailability of elements, they can provide input data for use in risk assessment models. Additionally, they also offer possibilities to perform a fast screening of the mobilizable pool of elements in soils and/or sediments. 1. Introduction The contamination of soils and sediments is widespread and is a potential threat for the environment in the short and long term. The impact of trace elements in soils and sediments on the environment depends on their speciation, mobility, and bioavailability. Over the past decades, the term “heavy metals” has increasingly been used, without any consistency to denote trace element contamination of environmental media. An overview of the use of the term “heavy metals” in scientific dictionaries and relevant literature can be found in Duffus [1]. Since “heavy metals” is a poor scientific term and many alternatives exit [2], we will use the term “trace elements” in the present study to refer to As, Cd, Cu, Cr, Ni, Pb, and Zn. Talking about trace metals would be incorrect because arsenic is actually a metalloid. Before discussing the different methods for determination of “trace element” availability in soils and/or sediments and before addressing the pros and cons of single and sequential extraction procedures, the difference between soils and sediments will be clarified, as well as the terminology used throughout this paper. 1.1. Soils versus Sediments Soils and sediments are different matrixes from many viewpoints, especially under the environmental context. “Soil” can be defined as a “three-dimensional body with properties that reflect the impact of climate, vegetation, fauna, and topography on soils parent material over a variable time span. Soils are still in a process of change. As a result of “soil formation” or “pedogenesis,” soil profiles show
The chicken as a model to study microchromosomes in birds: a review
Valérie Fillon
Genetics Selection Evolution , 1998, DOI: 10.1186/1297-9686-30-3-209
Abstract:
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