164 research outputs found

    Soft Institutions and the Diffusion of Management Innovations across Borders

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    This paper proposes an approach to support the understanding of the role of soft institutions (i.e. cultural values and norms) on the introduction and use of management practices when diffused across cultural (national/organisational) borders. This paper builds on empirical data from a case at Ericsson Radio System (Kista, Sweden). This case illustrates the impact of national values on the diffusion on process management practices in three different Ericsson subsidiaries in Sweden, Argentina and New Zealand. The paper concludes with the definition of research issues regarding the role of soft institutions on the diffusion of management innovation across borders

    Parcours des élèves en difficulté scolaire: Influence de l'offre de formation et de l'académie

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    National audienceL'orientation dans la voie générale et technologique après la troisième dépend fortement des politiques académiques d'orientation et de l'offre de formation, en particulier pour les élèves en difficulté scolaire. Seulement 13 % de ces derniers sont orientés en seconde générale et technologique dans les académies de Caen, de Nantes ou de Rennes, contre 38 % en Corse. Cinq groupes d'académies peuvent être définis pour expliquer l'orientation post-troisième. En fin de seconde générale et technologique, le type de lycée à proximité dans l'académie influence de nouveau le choix entre séries générales et technologiques pour les élèves de faible niveau scolaire. Entre les académies d'Orléans-tours ou de Rennes et celle de Corse, la probabilité de passage en première générale varie du simple au double (de 22 % à 44 %) pour le quart des élèves considérés comme les plus en difficulté scolaire

    Stimulatory effect of Echinacea purpurea extract on the trafficking activity of mouse dendritic cells: revealed by genomic and proteomic analyses

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    <p>Abstract</p> <p>Background</p> <p>Several <it>Echinacea </it>species have been used as nutraceuticals or botanical drugs for "immunostimulation", but scientific evidence supporting their therapeutic use is still controversial. In this study, a phytocompound mixture extracted from the butanol fraction (BF) of a stem and leaf (S+L) extract of <it>E. purpurea </it>([BF/S+L/Ep]) containing stringently defined bioactive phytocompounds was obtained using standardized and published procedures. The transcriptomic and proteomic effects of this phytoextract on mouse bone marrow-derived dendritic cells (BMDCs) were analyzed using primary cultures.</p> <p>Results</p> <p>Treatment of BMDCs with [BF/S+L/Ep] did not significantly influence the phenotypic maturation activity of dendritic cells (DCs). Affymetrix DNA microarray and bioinformatics analyses of genes differentially expressed in DCs treated with [BF/S+L/Ep] for 4 or 12 h revealed that the majority of responsive genes were related to cell adhesion or motility (<it>Cdh10</it>, <it>Itga6</it>, <it>Cdh1</it>, <it>Gja1 </it>and <it>Mmp8</it>), or were chemokines (<it>Cxcl2, Cxcl7) </it>or signaling molecules (<it>Nrxn1, Pkce </it>and <it>Acss1</it>). TRANSPATH database analyses of gene expression and related signaling pathways in treated-DCs predicted the JNK, PP2C-α, AKT, ERK1/2 or MAPKAPK pathways as the putative targets of [BF/S+L/Ep]. In parallel, proteomic analysis showed that the expressions of metabolic-, cytoskeleton- or NF-κB signaling-related proteins were regulated by treatment with [BF/S+L/Ep]. <it>In vitro </it>flow cytometry analysis of chemotaxis-related receptors and <it>in vivo </it>cell trafficking assay further showed that DCs treated with [BF/S+L/Ep] were able to migrate more effectively to peripheral lymph node and spleen tissues than DCs treated as control groups.</p> <p>Conclusion</p> <p>Results from this study suggest that [BF/S+L/Ep] modulates DC mobility and related cellular physiology in the mouse immune system. Moreover, the signaling networks and molecules highlighted here are potential targets for nutritional or clinical application of <it>Echinacea </it>or other candidate medicinal plants.</p

    Fucoidan Can Function as an Adjuvant In Vivo to Enhance Dendritic Cell Maturation and Function and Promote Antigen-Specific T Cell Immune Responses

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    Fucoidan, a sulfated polysaccharide purified from brown algae, has a variety of immune-modulation effects, including promoting antigen uptake and enhancing anti-viral and anti-tumor effects. However, the effect of fucoidan in vivo, especially its adjuvant effect on in vivo anti-tumor immune responses, was not fully investigated. In this study, we investigated the effect of fucoidan on the function of spleen dendritic cells (DCs) and its adjuvant effect in vivo. Systemic administration of fucoidan induced up-regulation of CD40, CD80 and CD86 expression and production of IL-6, IL-12 and TNF-α in spleen cDCs. Fucoidan also promoted the generation of IFN-γ-producing Th1 and Tc1 cells in an IL-12-dependent manner. When used as an adjuvant in vivo with ovalbumin (OVA) antigen, fucoidan promoted OVA-specific antibody production and primed IFN-γ production in OVA-specific T cells. Moreover, fucoidan enhanced OVA-induced up-regulation of MHC class I and II on spleen cDCs and strongly prompted the proliferation of OVA-specific CD4 and CD8 T cells. Finally, OVA immunization with fucoidan as adjuvant protected mice from the challenge with B16-OVA tumor cells. Taken together, these results suggest that fucoidan can function as an adjuvant to induce Th1 immune response and CTL activation, which may be useful in tumor vaccine development

    Les clones T, moyen d'exploration des antigenes mineurs impliques dans la reaction du greffon contre l'hote. [T clones, a means of exploring minor antigens involved in graft versus host reaction]

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    During MHC-matched bone marrow transplantation, a graft-versus-host reaction (GVH) mediated by donor T lymphocytes and directed against host minor histocompatibility antigens may be observed. The establishment of T cell clones from GVH mice has enabled us to study minor antigens recognized during the reaction. Most of the T cell clones were Thyl+CD4+CD8-alpha beta+. Four minor, weakly polymorphic antigens, were evidenced; two of those antigens, recognized by CD4+ T cell clones, were implicated in GVH. One CD8+ T cell clone cannot provoke GVH mortality. The two "killer" clones express V beta 18 and V beta 2 TCR gene segments, respectively

    A soluble hexameric form of CD40 ligand activates human dendritic cells and augments memory T cell response.

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    A strategy to improve the immunogenicity of candidate vaccines is to trigger the innate immune system. Triggering of CD40 at the surface of dendritic cells (DC) is essential in the induction of an efficient immune response. Although CD40 agonist antibodies have been shown to be potent inducers of immune responses in experimental models, serious safety concerns have been raised for their use in humans. In addition, the production of soluble functional CD40 ligand has been challenging and the soluble form existing so far is not developed anymore. Here, we have evaluated the potency of a new soluble form of hexameric CD40 ligand (sCD40L) to serve as an adjuvant for anti-viral T cell responses. sCD40L was able to activate human DC and to enhance virus-specific memory T cell responses. These results demonstrate that this soluble form of CD40 ligand may serve as an adjuvant for T cell response and thus provide the rationale for its potential use in T cell based vaccine strategies

    Probing the T-cell receptor repertoire with deep sequencing.

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    PURPOSE OF REVIEW: To review major findings on the T-cell receptor (TCR) repertoire diversity in response to several viral infections based on conventional methods of PCR, cloning and sequencing and to discuss their limitations in light of the recent methodological advances in deep sequencing.¦RECENT FINDINGS: Direct sequencing of TCR expressed by Ag-specific T cells isolated ex vivo has revealed that the TCR repertoire is not as restricted as previously estimated. Furthermore, analyses performed independently of the T-cell clonal hierarchy have brought to light an unexpected diversity. The choice of methods is critical to characterize the complexity of the repertoire. Recent advances in deep sequencing have uncovered the diversity of the TCR repertoire and shown that the size of the repertoire in naive and Ag-experienced memory T cells is three-fold to 15-fold larger than formerly estimated. Interestingly, the TCR complementary determining region 3 sequences are not randomly selected and a certain degree of shared TCR repertoire has been observed between different individuals.¦SUMMARY: Deep sequencing is a major methodological advance allowing more accurate molecular characterization of the TCR repertoire. In the near future, such technologies will further contribute to delineate the complexity of pathogen-specific T-cell response and help defining correlates of a protective immunity
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