49 research outputs found
Les recherches comparatives internationales en Ă©ducation
Cet article introductif analyse les problématiques méthodologiques de la comparaison internationale en éducation. Les différentes contributions au dossier sont introduites au cours de cette analyse en fonction de leurs positions par rapport à quelques grands clivages qui structurent ce champ de recherche
Les recherches comparatives internationales en Ă©ducation
Cet article introductif analyse les problématiques méthodologiques de la comparaison internationale en éducation. Les différentes contributions au dossier sont introduites au cours de cette analyse en fonction de leurs positions par rapport à quelques grands clivages qui structurent ce champ de recherche
FBXW7/hCDC4 controls glioma cell proliferation in vitro and is a prognostic marker for survival in glioblastoma patients
BACKGROUND: In the quest for novel molecular mediators of glioma progression, we studied the regulation of FBXW7 (hCDC4/hAGO/SEL10), its association with survival of patients with glioblastoma and its potential role as a tumor suppressor gene in glioma cells. The F-box protein Fbxw7 is a component of SCF(Fbxw7), a Skp1-Cul1-F-box E3 ubiquitin ligase complex that tags specific proteins for proteasome degradation. FBXW7 is mutated in several human cancers and functions as a haploinsufficient tumor suppressor in mice. Any of the identified targets, Cyclin E, c-Myc, c-Jun, Notch1/4 and Aurora-A may have oncogenic properties when accumulated in tumors with FBXW7 loss. RESULTS: We tested the expression of FBXW7 in human glioma biopsies by quantitative PCR and compared the transcript levels of grade IV glioma (glioblastoma, G-IV) with those of grade II tumors (G-II). In more than 80% G-IV, expression of FBXW7 was significantly reduced. In addition, levels of FBXW7 were correlated with survival indicating a possible implication in tumor aggressiveness. Locus 4q31.3 which carries FBXW7 was investigated by in situ hybridization on biopsy touchprints. This excluded allelic loss as the principal cause for low expression of FBXW7 in G-IV tumors. Two targets of Fbxw7, Aurora-A and Notch4 were preferentially immunodetected in G-IV biopsies. Next, we investigated the effects of FBXW7 misregulation in glioma cells. U87 cells overexpressing nuclear isoforms of Fbxw7 lose the expression of the proliferation markers PCNA and Ki-67, and get counterselected in vitro. This observation fits well with the hypothesis that Fbxw7 functions as a tumor suppressor in astroglial cells. Finally, FBXW7 knockdown in U87 cells leads to defects in mitosis that may promote aneuploidy in progressing glioma. CONCLUSION: Our results show that FBXW7 expression is a prognostic marker for patients with glioblastoma. We suggest that loss of FBXW7 plays an important role in glioma malignancy by allowing the accumulation of multiple oncoproteins and that interfering with Fbxw7 or its downstream targets would constitute a new therapeutic advance
Protocole Ad hoc Proactif Anonyme Ă Base de Cryptographie Homomorphique
National audienceAvec l'avĂšnement des systĂšmes ubiquitaires, la question du respect de la vie privĂ©e devient primordiale. DĂ» aux spĂ©cificitĂ©s de ces systĂšmes, il est particuliĂšrement difficile d'empĂȘcher la fuite d'informations telles que l'identitĂ© des personnes, leur emplacement gĂ©ographique, leurs relations, etc. Dans le monde des rĂ©seaux ad hoc, il est nĂ©cessaire que les protocoles de routage assurent la protection des identitĂ©s des noeuds ainsi que leur position tant gĂ©ographique que relative. Dans cet article, nous proposons un nouveau protocole de routage ad hoc proactif se basant sur la cryptographie homomorphique complĂšte pour assurer la protection des informations privĂ©es des noeuds. Cette technologie offre de nouvelles possibilitĂ©s : il n'est plus nĂ©cessaire de dĂ©chiffrer une information pour l'utiliser. Avec un minimum d'hypothĂšses, nous montrons qu'un protocole de routage ad hoc proactif garantissant un fort respect de la vie privĂ©e est possible
Pneumopathies communautaires à Staphylococcus aureus secréteur de leucocidine de Panton-Valentine (à propos de 4 cas cliniques)
PARIS6-Bibl.PitiĂ©-SalpĂȘtrie (751132101) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF
Analyse transcriptomique de la maladie de Whipple (nouveaux biomarqueurs et voies de signalisation)
La maladie de Whipple est une infection systĂ©mique, chronique et rare due Ă T. whipplei et provoque des symptĂŽmes intestinaux, endocardiques et neurologiques principalement. IdentifiĂ©e rĂ©cemment, cette bactĂ©rie intracellulaire infecte les monocytes et les macrophages. Le diagnostic de certitude repose encore sur une mĂ©thode invasive, la coloration PAS sur biopsie intestinale, et le pronostic est pĂ©joratif sans traitement antibiotique. L implication de mĂ©canismes immunologiques a Ă©tĂ© suggĂ©rĂ©e par de prĂ©cĂ©dents travaux, avec notamment une polarisation macrophagique M2/alternative inappropriĂ©e, un rĂŽle aggravant de l interleukine 16 et une rĂ©ponse interfĂ©ron insuffisante. Nous avons dĂ©cidĂ© de comparer les profils d expression des gĂšnes entre populations malades, porteuses et tĂ©moin Ă l aide de puces ciblant environ 40.000 sĂ©quences codantes. Nous avons donc extrait les ARNm et les avons contrĂŽlĂ©s et analysĂ©s par puces Ă ARN aprĂšs retrotranscription en cDNA. Les puces ont ensuite Ă©tĂ© scannĂ©es et les donnĂ©es normalisĂ©es, avant d ĂȘtre analysĂ©es par R, un logiciel bioinformatique adaptĂ©. Plus de 700 gĂšnes sont modulĂ©s Ă plus de 50% entre les populations exposĂ©es Ă la bactĂ©rie et la population tĂ©moin. Les analyses statistiques ont montrĂ© des diffĂ©rences d expression des gĂšnes impliquant principalement le systĂšme immunitaire, l apoptose, le mĂ©tabolisme des sucres et des lipides, l endocytose et le cycle cellulaire. Le gĂšne RPL21 codant une protĂ©ine ribosomale semble particuliĂšrement sous-exprimĂ©e chez les malades. Les patients porteurs asymptomatiques ne prĂ©sentent pas de diffĂ©rence significative par rapport aux patients atteints de maladie de Whipple. Au total, cette analyse descriptive du transcriptome de la maladie de Whipple offre de nombreuses donnĂ©es sur la physiopathologie dans des conditions rĂ©alistes, Ă savoir in vivo, chez l homme.Whipple s disease is a rare chronic infection due to Tropheryma whipplei in which alteration of host immune response seems to be critical. We previously described the gene expression of monocytes and macrophages stimulated by T. whipplei but the relationship between clinical expression, prognosis and gene expression in patients is unknown. We performed a gene expression of whole blood samples of 37 individuals ( 7 asymptomatic carriers, 6 patients with active Whipple s disease, 15 treated patients and 5 healthy controls). In patients with active Whipple s disease, the expression of 717 genes was significantly modulated as compared with healthy controls. These genes were classified using GO and KEGG pathways. The GO bioprocesses such as response to virus, carbohydrate metabolism, membrane organisation and biosynthesis were specifically enriched in patients with Whipple s disease. The analysis of KEGG pathways revealed the enrichment for apoptosis, Wnt, Jak/Stat, NK cytotoxicity and MAPK signalling pathways. Within papotosis pathways, BAX was strongly upregulated. It is noteworthy that asymptomatic carriers, treated patients and active patients were not significantly different but they were all significantly different from healthy controls. We purposed finally a candidate for risk factor, RPL21, which was strongly downregulated in exposed populations. This first transcriptome analysis of Whipple s disease patients reveals candidates for biomarkers and highlights Whipple s disease physiopathology.GRENOBLE1-BU MĂ©decine pharm. (385162101) / SudocSudocFranceF
Three Dimensions of Barriers to Dental Care for Psychiatric Inpatients
International audienc
AccĂšs aux soins buccodentaire en institution psychiatrique : Ă©tude des perceptions des chirurgiens-dentistes
International audienc
AccĂšs aux soins buccodentaires en institution psychiatrique : Ă©tude des perceptions des chirurgiens-dentistes
National audienc