28 research outputs found

    Redundant Notch1 and Notch2 Signaling Is Necessary for IFNγ Secretion by T Helper 1 Cells During Infection with Leishmania major

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    The protective immune response to intracellular parasites involves in most cases the differentiation of IFNγ-secreting CD4+ T helper (Th) 1 cells. Notch receptors regulate cell differentiation during development but their implication in the polarization of peripheral CD4+ T helper 1 cells is not well understood. Of the four Notch receptors, only Notch1 (N1) and Notch2 (N2) are expressed on activated CD4+ T cells. To investigate the role of Notch in Th1 cell differentiation following parasite infection, mice with T cell-specific gene ablation of N1, N2 or both (N1N2ΔCD4Cre) were infected with the protozoan parasite Leishmania major. N1N2ΔCD4Cre mice, on the C57BL/6 L. major-resistant genetic background, developed unhealing lesions and uncontrolled parasitemia. Susceptibility correlated with impaired secretion of IFNγ by draining lymph node CD4+ T cells and increased secretion of the IL-5 and IL-13 Th2 cytokines. Mice with single inactivation of N1 or N2 in their T cells were resistant to infection and developed a protective Th1 immune response, showing that CD4+ T cell expression of N1 or N2 is redundant in driving Th1 differentiation. Furthermore, we show that Notch signaling is required for the secretion of IFNγ by Th1 cells. This effect is independent of CSL/RBP-Jκ, the major effector of Notch receptors, since L. major-infected mice with a RBP-Jκ deletion in their T cells were able to develop IFNγ-secreting Th1 cells, kill parasites and heal their lesions. Collectively, we demonstrate here a crucial role for RBP-Jκ-independent Notch signaling in the differentiation of a functional Th1 immune response following L. major infection

    Evaluation du livret de conseils "l'allaitement au fil du temps"

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    RENNES1-BU Santé (352382103) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

    VII. 1. Préparation du défunt

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    Pinard Estelle, Guichard Yves, Pommepuy Claudine, Breton Cécile, Desenne Sophie. VII. 1. Préparation du défunt. In: Revue archéologique de Picardie. Numéro spécial 26-2, 2009. Bucy-Le-Long (Aisne). Une nécropole de La Tène ancienne (Ve-IVe siècle avant notre ère). Volume II. Évolution du mobilier et des pratiques funéraires : une approche chrono-culturelle, présentation des fouilles allemandes de 1915. pp. 479-482

    Chambly « La Remise Ronde » (Oise), une nécropole de La Tène ancienne

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    An early La Tene necropolis with fifty-eight burials has been discovered at chambly in the southern part of the Département de l'Oise. A study of artefacts and of funeral practices has evidenced its relevance to the Aisne-Marne group, although well to the west of that cultural area.Une nécropole de La Tène ancienne, composée de cinquante-huit sépultures, a été découverte à Chambly, au sud du département de l'Oise. Les études des mobiliers et des pratiques funéraires montrent son appartenance au groupe Aisne-Marne malgré une localisation très à l'ouest de cette aire culturelle.Pinard Estelle, Delattre Valérie, Friboulet Muriel, Breton Cécile, Krier Vincent. Chambly « La Remise Ronde » (Oise), une nécropole de La Tène ancienne. In: Revue archéologique de Picardie, n°3-4, 2000. La Thiérache archéologique et historique (Aisne) / La nécropole laténienne de Chambly (Oise) / Les sarcophages gallo-romains en plomb du musée d'Amiens (Somme) pp. 3-75

    D'où viens-tu? : Pierre Chaumont, Dayna Danger, Chun Hua Catherine Dong

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    "D’où viens-tu? [Where are you from?]: an exhibition with Pierre Chaumont, Dayna Danger and Chun Hua Catherine Dong at Art Mûr. An exhibition organized by Collectif 13, a group of UQAM art history students, presenting powerful works that address the body as political territory." -- Online press release

    Intérêt de l'élastométrie impulsionnelle dans l'évaluation non invasive du stade de fibrose hépatique chez l'enfant. [Value of transient elastography in noninvasive assessment in children's hepatic fibrosis].

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    International audienceAIM: Transient elastography (FibroScan) is a novel, noninvasive, rapid bedside method to assess liver fibrosis by measuring liver stiffness. This study aimed to determine the feasibility and reliability of liver stiffness measurement in children with liver diseases. PATIENTS AND METHODS: Liver stiffness measurements were carried out on 72 children, from 4 to 18 years of age, with potential hepatic fibrosis disease. The clinical, biological, ultrasonographic, and endoscopic parameters were noted to identify children with portal hypertension syndrome. The APRI (ASAT-to-platelet ratio index) test was calculated according to the standard formula. An APRI test score higher than 1.5 indicates significant hepatic fibrosis. METAVIR scoring from 14 liver biopsies was compared to the liver stiffness using the Kappa statistic. RESULTS: Twenty-eight patients had viral hepatitis, 20 cystic fibrosis, 16 chronic liver cholestasis, 5 autoimmune hepatitis, and 3 patients had liver fibrosis with uncertain etiology. FibroScan measurements were available in all children. There was good agreement between FibroScan and pathological studies (weighted kappa=0.814). Only 9 children had portal hypertension syndrome with an average measurement of liver stiffness significantly higher than children without portal hypertension (26.5kPa vs 6.4kPa; p<0.01). The APRI test for 6 out of 9 patients scored higher than 1.5. CONCLUSION: These results indicate that liver stiffness measurement is feasible in children and seems to be related to liver fibrosis. Larger prospective studies are needed to validate this FibroScan method

    The multifaceted nature of the relationship between performance and brain activity in motor sequence learning.

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    The 'learning and performance' conundrum has for a long time puzzled the field of cognitive neuroscience. Deciphering the genuine functional neuroanatomy of motor sequence learning, among that of other skills, has thereby been hampered. The main caveat is that changes in neural activity that inherently accompany task practice may not only reflect the learning process per se, but also the basic motor implementation of improved performance. Previous research has attempted to control for a performance confound in brain activity by adopting methodologies that prevent changes in performance. However, blocking the expression of performance is likely to distort the very nature of the motor sequence learning process, and may thus represent a major confound in itself. In the present study, we postulated that both learning-dependent plasticity mechanisms and learning-independent implementation processes are nested within the relationship that exists between performance and brain activity. Functional magnetic resonance imaging (fMRI) was used to map brain responses in healthy volunteers while they either (a) learned a novel sequence, (b) produced a highly automatized sequence or (c) executed non-sequential movements matched for speed frequency. In order to dissociate between qualitatively distinct, but intertwined, relationships between performance and neural activity, our analyses focused on correlations between variations in performance and brain activity, and how this relationship differs or shares commonalities between conditions. Results revealed that activity in the putamen and contralateral lobule VI of the cerebellum most strongly correlated with performance during learning per se, suggesting their key role in this process. By contrast, activity in a parallel cerebellar network, as well as in motor and premotor cortical areas, was modulated by performance during learning and during one or both control condition(s), suggesting the primary contribution of these areas in motor implementation, either as a function or not of the sequential content of movements. Our findings thus highlight the multifaceted nature of the link between performance and brain activity, and suggest that different components of the striato-cortical and cerebello-cortical motor loops play distinct, but complementary, roles during early motor sequence learning.Journal ArticleResearch Support, Non-U.S. Gov'tinfo:eu-repo/semantics/publishe

    Inflammatory Bowel Diseases and School Absenteeism

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    International audienceObjectives - Inflammatory bowel diseases (IBDs) are chronic diseases which negatively affect the schooling of children. The aim is to analyze school absenteeism and its causes in children followed for IBD. Methods - A prospective multicenter study of IBD patients aged from 5 to 18 years old, from September 2016 to June 2017. Data on absenteeism and its causes were collected via a monthly questionnaire completed by patients or their family by mail. The results were compared with existing data supplied by the school authorities (497 students without IBD divided by class). Results - A total of 106 patients (62 boys), median age of 14 (5-18), were included. The global response rate was 83.1%. The patients with IBD were absent an average of 4.8% ± 5.5% of school days during the school year, against 3.2% ± 1.6% for non IBD group (P = 0.034). Digestive disorders accounted for 34% of the causes of absenteeism. Approximately 27% of the absences were due to scheduled events (hospitalizations, endoscopy, or consultations). By excluding the absences for scheduled care, the rate of school absenteeism of patients with IBD is significantly lower than that of non-IBD group. Conclusion - Children with IBD are more frequently absent from school than non-IBD group. The main cause of school absenteeism appears to be associated with the disease itself. The share of scheduled absenteeism is quite large. The organization and scheduling of the patients' care path must be a priority to maximally limit the negative impact of their disease on the patients' schooling

    Geochemical heterogeneities within the Crozet hotspot

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    International audienceThe Crozet Plateau is a 54 Ma-old volcanic plateau that supports five islands characterized by recent volcanic manifestations that are the surface expression of a deep-mantle plume. Due to their remote location and difficult access, the Crozet Islands are poorly sampled. Both the petrological descriptions and geochemical data are scarce. Thus, the sources of the Crozet plume are still under debate. Similarly, the interactions between the Southwest Indian Ridge (SWIR) and the Crozet plume remain questioned. Here, we present a new set of isotopes (Pb, Sr, Nd and He), major and trace elements data on basalts from three islands of the Crozet Archipelago: Penguins, East, and Possession Islands. Our main purpose is to characterize the sources of the Crozet plume and to test its influence at regional scale. Two groups of lavas can be distinguished based on the isotopic data: East and Possession lavas, and Penguins lavas. Principal component analyses on our high-precision Pb isotopes data and literature data show that two mantle sources can explain most of the geochemical variability measured in Crozet lavas. A third minor contribution is however needed to fully explain the data. The entire set of isotopic compositions (Pb, Sr, Nd and He) can be explained by a mixing between three mantle sources: (1) a FOZO (Focus Zone) component, with 206Pb/204Pb higher than 19.5 and high 207Pb/204Pb, 208Pb/204Pb 87Sr/86Sr, 143Nd/144Nd and R/RaR/Ra (R/Ra=(He3/He4)sample/(He3/He4)atmosphere) ratios, that is mainly sampled Penguins lavas, (2) a component called "East-Possession" that is mostly sampled by the East-Possession lava group and which presents Pb, Sr and Nd isotope signatures similar to those of the Reunion-Mauritius Islands, and (3) a third minor contribution of the local Depleted MORB Mantle (DMM). The new He isotopes data on the Crozet plume allow us to propose that Crozet plume material is present in the segment of the Southwest Indian Ridge located between the Indomed (ITF) and Gallieni (GTF) transform faults. This hypothesis is confirmed by a mixing model based on trace-elements and isotopes data from the ITF-GTF segment of the SWIR and Crozet. We propose that the shallow mantle below the ITF-GTF segment of the SWIR is contaminated by deep material from the Crozet plume
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