228 research outputs found
Electronic design for velocity measurement with digital signal processor
This paper deals with the design and realization of signal processing
electronic system used for the measure of velocity without contact .
After mentionning the différent ways of mesuring we briefly discuss the
methods of measurement without contact in order to show the advantages
they present and also to let appear the limits imposed by the processing
units .
We have tested the différent processings which allow the measure of
velocity and came oui with an architecture that uses a digital processor. We propose then an electronic processing system which, is fast, low cost, and
easy ta use .
As an application we use this ystem for the measure of velocity by
crosscorrelation .Cette étude concerne la conception et la réalisation d'un dispositif
électronique de traitement du signal dédié à la vélocimétrie sans contact .
Après avoir énuméré les différentes méthodes de mesure de vitesse on
fait un bref rappel de celles se faisant sans contact pour montrer les
énormes avantages qu'elles présentent mais surtout les limites imposées
par les unités de traitements .
Nous analysons les différents traitements nécessaires à l'obtention de la
mesure pour en déduire une architecture optimisée à base de DSP . Partant de là nous proposons un dispositif électonique de mesure
présentant des performances intéressantes en rapidité en souplesse
d'emploi et de faible coût.
Enfin nous validons les performances de notre dispositif en l'utilisant
comme support dans la mise en rouvre d'une de ces méthodes (Vélocimétrie
par intercorrélation)
Effects of copper fungicide spraying on volatile thiols of the varietal aroma of Sauvignon blanc, Cabernet Sauvignon and Merlot wines
In a three-year experiment, the effect of pre-veraison copper sprayings of vines on must composition and some volatile thiols contributing to the varietal aroma of Sauvignon blanc, Cabernet Sauvignon and Merlot wines was studied in comparison with folpet sprayings in the Bordeaux winegrowing region. The readivity of copper residues with thiols, mainly during the alcoholic fermentation, had a dramatic effect on the concentration of 4-mercapto-4-methylpentan-2-one and 3-mercaptohexanol in wines. However, copper sprayings, preferentially on the foliage, did not significantly increase copper residues in must; thiol concentrations in wines were very close to those found in wines obtained from vines sprayed with folpet. Therefore, this mode of spraying can be used to avoid the effects of copper treatment at veraison on the volatile thiols of the wines varietal aroma.
The Pro-tumorigenic IL-33 Involved in Antitumor Immunity: A Yin and Yang Cytokine
Interleukin-33 (IL-33), considered as an alarmin released upon tissue stress or damage, is a member of the IL-1 family and binds the ST2 receptor. First described as a potent initiator of type 2 immune responses through the activation of T helper 2 (TH2) cells and mast cells, IL-33 is now also known as an effective stimulator of TH1 immune cells, natural killer (NK) cells, iNKT cells, and CD8 T lymphocytes. Moreover, IL-33 was shown to play an important role in several cancers due to its pro and anti-tumorigenic functions. Currently, IL-33 is a possible inducer and prognostic marker of cancer development with a direct effect on tumor cells promoting tumorigenesis, proliferation, survival, and metastasis. IL-33 also promotes tumor growth and metastasis by remodeling the tumor microenvironment (TME) and inducing angiogenesis. IL-33 favors tumor progression through the immune system by inducing M2 macrophage polarization and tumor infiltration, and upon activation of immunosuppressive cells such as myeloid-derived suppressor cells (MDSC) or regulatory T cells. The anti-tumor functions of IL-33 also depend on infiltrated immune cells displaying TH1 responses. This review therefore summarizes the dual role of this cytokine in cancer and suggests that new proposals for IL-33-based cancer immunotherapies should be considered with caution
Modulation of pro-inflammatory activation of monocytes and dendritic cells by aza-bis-phosphonate dendrimer as an experimental therapeutic agent
INTRODUCTION: Our objective was to assess the capacity of dendrimer aza-bis-phosphonate (ABP) to modulate phenotype of monocytes (Mo) and monocytes derived dendritic cells (MoDC) activated in response to toll-like receptor 4 (TLR4) and interferon γ (IFN- γ) stimulation. METHODS: Mo (n = 12) and MoDC (n = 11) from peripheral blood of healthy donors were prepared. Cells were preincubated or not for 1 hour with dendrimer ABP, then incubated with lipopolysaccharide (LPS; as a TLR4 ligand) and (IFN-γ) for 38 hours. Secretion of tumor necrosis factor α (TNFα), interleukin (IL) -1, IL-6, IL-12, IL-10 and IL-23 in the culture medium was measured by enzyme-linked immunosorbent assay (ELISA) and Cytokine Bead Array. Differentiation and subsequent maturation of MoDC from nine donors in the presence of LPS were analyzed by flow cytometry using CD80, CD86, CD83 and CD1a surface expression as markers. RESULTS: Mo and MoDC were orientated to a pro-inflammatory state. In activated Mo, TNFα, IL-1β and IL-23 levels were significantly lower after prior incubation with dendrimer ABP. In activated MoDC, dendrimer ABP promoted IL-10 secretion while decreasing dramatically the level of IL-12. TNFα and IL-6 secretion were significantly lower in the presence of dendrimer ABP. LPS driven maturation of MoDC was impaired by dendrimer ABP treatment, as attested by the significantly lower expression of CD80 and CD86. CONCLUSION: Our data indicate that dendrimer ABP possesses immunomodulatory properties on human Mo and MoDC, in TLR4 + IFN-γ stimulation model, by inducing M2 alternative activation of Mo and promoting tolerogenic MoDC
Diagnostic imaging of equine thoracolumbar disorders
Equine thoracolumbar conditions represent a major cause of poor performance and locomotor disorders
in sports and race horses. Advances in diagnostic imaging during the last 15 years allow today to
diagnose most equine back lesions in the standing sedated horse. Radiography is the first choice imaging
modality due to its high diagnostic performance. Ultrasonography is a complementary modality to
further investigate back soft tissues and the caudal lumbar area not evaluable radiographically in the
standing horse. Bone scintigraphy is a more complex and expensive technique and is usually
dedicated to complicated clinical cases. The most frequent injuries diagnosed using these 3 modalities
are kissing spines, osteo-arthrosis of the synovial intervetebral joints, vertebral spondylosis and muscle
injuries. Clinical significance of these lesions should be interpreted with care considering the clinical
signs exhibited by the horse but also its sports or racing useLes affections vertébrales thoracolombaires représentent une cause fréquente de baisse de performances
et/ou de troubles locomoteurs chez les chevaux de sport et de courses. Le développement des
techniques d’imagerie ces 15 dernières années permet aujourd’hui au vétérinaire équin de diagnostiquer
un grand nombre de lésions affectant la colonne thoracolombaire sur le cheval debout tranquillisé.
La radiographie du dos du cheval constitue la modalité d’imagerie de premier choix par sa capacité
diagnostique élevée. L’échographie complète la radiographie dans l’exploration des tissus mous et
de la région lombaire caudale, cette dernière n’étant pas accessible par radiographie sur le cheval
debout. La scintigraphie, technique plus onéreuse et plus contraignante, est envisagée pour des cas
cliniques complexes. Les lésions les plus fréquemment diagnostiquées avec ces techniques d’imagerie
sont représentées par les conflits et fractures des processus épineux, les arthroses synoviales intervertébrales,
les spondyloses vertébrales et les lésions musculaires. La signification clinique de ces lésions
doit être évaluée en considérant les signes cliniques du patient mais également sa discipline sportiv
Modulation of γδ T-cell activation by neutrophil elastase
γδ T cells are non-conventional, innate-like T cells, characterized by a restricted T-cell receptor repertoire. They participate in protective immunity responses against extracellular and intracellular pathogens, tumour surveillance, modulation of innate and adaptive immune responses, tissue healing, epithelial cell maintenance and regulation of physiological organ function. In this study, we investigated the role of neutrophils during the activation of human blood γδ T cells through CD3 molecules. We found that the up-regulation of CD69 expression, and the production of interferon-Îł and tumour necrosis factor-α induced by anti-CD3 antibodies was potentiated by neutrophils. We found that inhibition of caspase-1 and neutralization of interleukin-18 did not affect neutrophil-mediated modulation. By contrast, the treatment with serine protease inhibitors prevented the potentiation of γδ T-cell activation induced by neutrophils. Moreover, the addition of elastase to γδ T-cell culture increased their stimulation, and the treatment of neutrophils with elastase inhibitor prevented the effect of neutrophils on γδ T-cell activation. Furthermore, we demonstrated that the effect of elastase on γδ T cells was mediated through the protease-activated receptor, PAR1, because the inhibition of this receptor with a specific antagonist, RWJ56110, abrogated the effect of neutrophils on γδ T-cell activation.Fil: Towstyka, Nadia YasmĂn. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Shiromizu, Carolina Maiumi. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Keitelman, Irene AngĂ©lica. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Sabbione, Florencia. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Salamone, Gabriela Veronica. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Departamento de MicrobiologĂa. Cátedra de MicrobiologĂa, ParasitologĂa e InmunologĂa; ArgentinaFil: Geffner, Jorge RaĂşl. Universidad de Buenos Aires. Facultad de Medicina. Departamento de MicrobiologĂa. Cátedra de MicrobiologĂa, ParasitologĂa e InmunologĂa; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Houssay. Instituto de Investigaciones BiomĂ©dicas en Retrovirus y Sida. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones BiomĂ©dicas en Retrovirus y Sida; ArgentinaFil: Trevani, AnalĂa Silvina. Universidad de Buenos Aires. Facultad de Medicina. Departamento de MicrobiologĂa. Cátedra de MicrobiologĂa, ParasitologĂa e InmunologĂa; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Jancic, Carolina Cristina. Universidad de Buenos Aires. Facultad de Medicina. Departamento de MicrobiologĂa. Cátedra de MicrobiologĂa, ParasitologĂa e InmunologĂa; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; Argentin
Plasmodium falciparum Adhesion on Human Brain Microvascular Endothelial Cells Involves Transmigration-Like Cup Formation and Induces Opening of Intercellular Junctions
Cerebral malaria, a major cause of death during malaria infection, is characterised by the sequestration of infected red blood cells (IRBC) in brain microvessels. Most of the molecules implicated in the adhesion of IRBC on endothelial cells (EC) are already described; however, the structure of the IRBC/EC junction and the impact of this adhesion on the EC are poorly understood. We analysed this interaction using human brain microvascular EC monolayers co-cultured with IRBC. Our study demonstrates the transfer of material from the IRBC to the brain EC plasma membrane in a trogocytosis-like process, followed by a TNF-enhanced IRBC engulfing process. Upon IRBC/EC binding, parasite antigens are transferred to early endosomes in the EC, in a cytoskeleton-dependent process. This is associated with the opening of the intercellular junctions. The transfer of IRBC antigens can thus transform EC into a target for the immune response and contribute to the profound EC alterations, including peri-vascular oedema, associated with cerebral malaria
Intercellular Transfer of Oncogenic H-Ras at the Immunological Synapse
Immune cells establish dynamic adhesive cell–cell interactions at a specific contact region, termed the immunological synapse (IS). Intriguing features of the IS are the formation of regions of plasma membrane fusion and the intercellular exchange of membrane fragments between the conjugated cells. It is not known whether upon IS formation, intact intracellular proteins can transfer from target cells to lymphocytes to allow the transmission of signals across cell boundaries. Here we show by both FACS and confocal microscopy that human lymphocytes acquire from the cells they scan the inner-membrane protein H-Ras, a G-protein vital for common lymphocyte functions and a prominent participant in human cancer. The transfer was cell contact-dependent and occurred in the context of cell-conjugate formation. Moreover, the acquisition of oncogenic H-RasG12V by natural killer (NK) and T lymphocytes had important biological functions in the adopting lymphocytes: the transferred H-RasG12V induced ERK phosphorylation, increased interferon-γ and tumor necrosis factor-α secretion, enhanced lymphocyte proliferation, and augmented NK-mediated target cell killing. Our findings reveal a novel mode of cell-to-cell communication—allowing lymphocytes to extend the confines of their own proteome—which may moreover play an important role in natural tumor immunity
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