15 research outputs found

    Coordination de la prolifération et de la migration neuronale par p27kip1 au cours de la corticogénÚse

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    Cortical cytoarchitecture relies on the spatiotemporal coordination of neuronal production rate, precursors cell-cycle control and neuronal radial migration towards the cortical plate. In the primate, area 17 supragranular layers are more developed than in area 18, due to higher proliferation and neuronal production rates in area 17 between E77-80. Two-photon videomicroscopy observations on cortical organotypic slices revealed that radial migration is faster in area 17 than 18. This indicates that area-specific variations of proliferation and migration rates are congruent during corticogenesis. The study of molecular mechanisms underlying the coordinated regulation of proliferation and migration focused on the cell-cycle regulator p27kip1, which promotes migration, via inhibition of the Rhoa GTPase by its C-terminal domain. This p27 dual function could play a major role during the Interkinetic Nuclear Migration (INM) performed by cortical precursor cells from the ventricular zone, in synchrony with the cell-cycle phases. Mutant forms of p27 or shRNA were electroporated into neuroblasts of E14-15 mice embryos. Two-photon videomicroscopy observations on organotypic slices revealed that p27 affects INM, promotes differentiative divisions and neuronal radial migration, though its C-terminal domain. P27 is thus part of a molecular network which finely tunes, in an area-specific manner, the successive rounds of divisions of precursor, as well as the migratory behavior of the newborn neuronsLa cytoarchitecture du nĂ©ocortex repose sur la coordination spatiotemporelle des taux de production des neurones ‐via la rĂ©gulation du cycle cellulaire de leurs progĂ©niteurs‐ et de leur migration radiale vers la surface corticale. Chez le primate, les couches supragranulaires de l'aire 17 sont plus dĂ©veloppĂ©es que celles de l'aire 18, consĂ©quence d'une prolifĂ©ration et d'une production neuronale accrues dans l'aire 17 Ă  E77‐80. Des observations en vidĂ©omicroscopie bi‐photonique, sur tranches organotypiques de cortex, rĂ©vĂšlent que la migration radiale est plus rapide dans l'aire 17. Les variations aire‐spĂ©cifiques des taux de prolifĂ©ration et de migration neuronale sont donc congruentes. L'Ă©tude des mĂ©canismes molĂ©culaires qui sous‐tendent la rĂ©gulation coordonnĂ©e de la prolifĂ©ration et de la migration est centrĂ©e sur le rĂ©gulateur du cycle cellulaire p27kip1, qui via son domaine C‐terminal promeut la migration en inhibant la GTPase RhoA. Ce rĂŽle plĂ©iotrope de p27 a Ă©tĂ© explorĂ© dans la migration nuclĂ©aire intercinĂ©tique (INM) qu'effectuent les prĂ©curseurs de la zone ventriculaire corticale, en synchronie avec les phases du cycle cellulaire. Des formes mutantes de p27 ou des shRNA ont Ă©tĂ© Ă©lectroporĂ©s spĂ©cifiquement dans les neuroblastes d'embryons murins Ă  E14‐15. Des observations en vidĂ©omicroscopie bi‐photonique sur tranches organotypiques rĂ©vĂšlent que le domaine C-terminal de p27 affecte l'INM, promeut les dĂ©cisions diffĂ©renciatives et la migration radiale. P27 se place donc au sein d'un rĂ©seau molĂ©culaire contrĂŽlant conjointement, et de façon aire-spĂ©cifique, les divisions successives des prĂ©curseurs corticaux, ainsi que la migration des neurones qui en sont issu

    La visite à domicile en médecine générale (opinions de six médecins généralistes de la région nantaise par la méthode du focus group)

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    La visite à domicile est un acte courant et spécifique de l'activité du médecin généraliste. Depuis 20 ans, le nombre de visites n'a cessé de décroßtre, pour des raisons économiques et démographiques. A l'époque actuelle d'hyperspécialisation de la médecine, on s'est interrogé sur la place de la visite. Nous avons demandé à 6 médecins généralistes de la région nantaise leur opinion lors d'un focus group. La qualité technique de la visite à domicile a été jugée mauvaise. Le changement du lieu de consultation entraßnait une perte des repÚres pouvant modifier la décision médicale. Cependant, l'ensemble des médecins interrogés ont rapporté apprécier faire des visites. L'observation du domicile apportait des informations sur l'autonomie réelle du patient. La visite à domicile était un moment de pause dans l'enchaßnement des consultations. La relation médecin-patient était différente de celle au cabinet. Nous avons conclu qu'il existait un paradoxe dans cet acte jugé médiocre techniquement mais indispensable à l'activité de la médecine générale. Les médecins participants ont souvent eu une vision idéaliste de la visite. Elle faisait partie de leur mission. Le praticien était le coordinateur des aides centrées sur le patient et son environnement. Le développement du maintien à domicile a ouvert de nouveaux besoins.Summary: Home visits are common to the activity of General Practitioners, and constitute an important area of their work. However, for the last twenty years, the amount of visits has decreased, for both economical and demographical reasons. Today, with the overspecialization of medicine, our aim was to question the efficiency of home visits. During a focus group, we asked the opinion of six General Practitioners from the Nantes region. The technical quality of home visits was judged inefficient. The fact that the consultations took place at various locations led the Practitioner to loose his medical marks which could affect the quality of a diagnosis. However, all the Doctors who were interviewed admitted that they appreciate the visits. The observation of the home of the patient gave to the Doctors important information about the real autonomy of the patient. Home visits were a welcomed break in their successions of consultations. The relationship between the Doctor and the patient approved different from the one in the medical practice. We concluded that there was a paradox in this medical act, very poorly judged from a technical point of view but nonetheless indispensable. All the Doctors involved in the debate often had an idealistic view of home visits. It was a central part of their mission. The Practitioner was the coordinator of this domestic assistance which focused on the patient and his or her environment. The development of home aid has created new needs.NANTES-BU Médecine pharmacie (441092101) / SudocSudocFranceF

    Salles propres et maßtrise de la contamination (conception et validation, application à un préparatoire pour solutions injectables )

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    Les laboratoires pharmaceutiques doivent faire face à des contraintes réglementaires de plus en plus exigeantes pour diminuer les risques de contamination des médicaments. Ceci s'applique d'autant plus pour les préparations injectables. Ainsi, est apparu le besoin de mettre en place un environnement contrÎlé appelé communément salle propre. Cette maitrise de l'environnement des locaux se déroule en 2 étapes fondamentales : la conception adaptée aux besoins recherchés suivie de la qualification permettant de garantir un procédé constant et reproductible. Ce travail expose, dans une premiÚre partie, des notions théoriques sur le concept de qualification/validation. Dans une deuxiÚme partie, sont décrits les principaux moyens pour lutter contre la contamination. Enfin, la troisiÚme partie est consacrée à une application pratique concernant l'installation d'un préparatoire pour des solutions injectablesTOURS-BU Sciences Pharmacie (372612104) / SudocSudocFranceF

    Infliximab quantitation in human plasma by liquid chromatography-tandem mass spectrometry: towards a standardization of the methods?

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    International audienceInfliximab (IFX) is a chimeric monoclonal antibody targeting tumor necrosis factor-alpha. It is currently approved for the treatment of certain rheumatic diseases or inflammatory bowel diseases. Clinical studies have suggested that monitoring IFX concentrations could improve treatment response. However, in most studies, IFX was quantified using ELISA assays, the resulting discrepancies of which raised concerns about their reliability. Here, we describe the development and validation of a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for IFX quantification in human plasma. Full-length stable-isotope-labeled antibody (SIL-IFX) was added to plasma samples as internal standard. Samples were then prepared using Mass Spectrometry Immuno Assay (MSIAℱ) followed by trypsin digestion and submitted to multiple reaction monitoring (MRM) for quantification of IFX. The chromatographic run lasted 13 min. The range of quantification was 1 to 26 mg/L. For two internal quality controls spiked with 6 and 12 mg/L of IFX, the method was reproducible (coefficients of variation (CV%): 12.7 and 2.1), repeatable (intra-day CV%: 5.5 and 5.0), and accurate (inter-day and intra-day deviations from nominal values: +6.4 to +3.7 % and 5.5 to 9.2 %, respectively). There was no cross - contamination effect. Samples from 45 patients treated with IFX were retrospectively analyzed by LC-MS/MS and results were compared to those obtained with an in-house ELISA assay and the commercial Lisa Tracker¼ method. Good agreement was found between LC-MS/MS and in-house ELISA (mean underestimation of 13 % for in-house ELISA), but a significant bias was found with commercial ELISA (mean underestimation of 136 % for commercial ELISA). This method will make it possible to standardize IFX quantification between laboratories. Graphical Abstract Interassay comparison of the three methods: LC-MS/MS vs inhouse ELISA assay or vs Lisa Tracker¼ ELISA assays, Passing & Bablok (a) and Bland & Altman (b) for the comparison of LC-MS/MS vs in-house ELISA assay; Passing & Bablo

    Femmes en guerre

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    Si la guerre est pensĂ©e comme un monde d’hommes, les femmes y ont aussi toute leur place et y jouent un rĂŽle actif. À la croisĂ©e de l’histoire du fait guerrier et de l’histoire du genre, Femmes en guerre explore ainsi les multiples facettes de la prĂ©sence des femmes au sein des armĂ©es, de l’époque mĂ©diĂ©vale Ă  nos jours. Il souligne tout d’abord la variĂ©tĂ© de leurs expĂ©riences, comme combattantes, cheffes de guerre ou dans des rĂŽles de soin plus traditionnellement associĂ©s Ă  la fĂ©minitĂ©. C’est Ă©galement une rĂ©flexion sur le genre que propose cet ouvrage, tant sur la construction des fĂ©minitĂ©s en milieu guerrier que sur ce que la prĂ©sence des femmes en milieu militaire dit de la virilitĂ© guerriĂšre. Enfin, alors que les rĂ©cits de guerre sont souvent accaparĂ©s par les hommes et que les femmes sont parfois invisibilisĂ©es par les sources, ce livre s’attache Ă  redonner toute leur place Ă  ces voix de femmes en guerre.Combining War history and gender studies, Femmes en Guerre explores the multiple forms of the presence of women within armies, their experiences of war and the construction of “femininities” in war contexts

    Cardiovascular manifestations in men and women carrying a FBN1 mutation

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    International audienceAims In patients with Marfan syndrome and other type-1 fibrillinopathies, genetic testing is becoming more easily available, leading to the identification of mutations early in the course of the disease. This study evaluates the cardiovascular (CV) risk associated with the discovery of a fibrillin-1 (FBN1) mutation. Methods and results A total of 1013 probands with pathogenic FBN1 mutations were included, among whom 965 patients [median age: 22 years (11– 34), male gender 53%] had data suitable for analysis. The percentage of patients with an ascending aortic (AA) dilatation increased steadily with increasing age and reached 96% (95% CI: 94 –97%) by 60 years. The presence of aortic events (dissection or prophylactic surgery) was rare before 20 years and then increased progressively, reaching 74% (95% CI: 67–81%) by 60 years. Compared with women, men were at higher risk for AA dilatation [≀30 years: 57% (95% CI: 52– 63) vs. 50% (95% CI: 45– 55), P ÂŒ 0.0076] and aortic events [≀30 years: 21% (95% CI: 17–26) vs. 11% (95% CI: 8–16), P , 0.0001; adjusted HR: 1.4 (1.1 –1.8), P ÂŒ 0.005]. The prevalence of mitral valve (MV) prolapse [≀60 years: 77% (95% CI: 72– 82)] and MV regurgitation [≀60 years: 61% (95% CI: 53–69)] also increased steadily with age, but surgery limited to the MV remained rare [≀60 years: 13% (95% CI: 8– 21)]. No difference between genders was observed (for all P. 0.20). From 1985 to 2005 the prevalence of AA dilatation remained stable (P for trend ÂŒ 0.88), whereas the percentage of patients with AA dissection significantly decreased (P for trend ÂŒ 0.01). Conclusion The CV risk remains important in patients with an FBN1 gene mutation and is present throughout life, justifying regular aortic monitoring. Aortic dilatation or dissection should always trigger suspicion of a genetic background leading to thorough examination for extra-aortic features and comprehensive pedigree investigation
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