Sparse denoising and adaptive estimation enhances the resolution and contrast of fluorescence emission difference microscopy based on array detector

International audienceArray detector allows a resolution gain for confocal microscopy by combining images sensed by a set of photomultipliers tubes (or sub-detectors). Several methods have been proposed to reconstruct a high-resolution image by linearly combining sub-detector images, especially the fluorescence emission difference (FED) technique. To improve the resolution and contrast of FED microscopy based on array detector, we propose to asso-ciate sparse denoising with spatial adaptive estimation. We show on both calibration slides and real data that our approach applied to the full stack of spatially reassigned detector signals, enables to achieve a higher reconstruction performance in terms of resolution, image contrast, and noise reduction

Aurora-A overexpression leads to override of the microtubule-kinetochore attachment checkpoint.

International audienceThe amplification of AURORA-A is frequently observed in specific epithelial cell malignancies. The overexpression of aurora-A, a Ser-Thr kinase known to localize to centrosomes during mitosis, appears to imbue cancerous cells with resistance to spindle-checkpoint-targeting drugs such as paclitaxel (Taxol). Indeed, a recent publication by Anand et al. indicates that overexpression of AURORA-A may interfere with spindle-microtubule attachment and disrupt the regulation of the spindle checkpoint by allowing cells with abnormal chromosomal separation to enter anaphase. Thus, the design of new drugs that specifically target aurora-A rather than other checkpoint proteins might alleviate the resistance to Taxol-like clinical therapeutics observed in some tumors

Analyse Dynamique : apport de la vidéomicroscopie et atouts de la microscopie multiphotonique à l'étude du vivant.

Communication oral

Allergies (l'homéopathie a-t-elle prouvé son efficacité ?)

TOURS-BU Sciences Pharmacie (372612104) / SudocSudocFranceF

Empirical SURE-guided microscopy super-resolution image reconstruction from confocal multi-array detectors

International audienceThe new generation of confocal microscopes are equipped with an array detector that generates an array of images corresponding to a multiview of the same sample. Several computational methods have been proposed to reconstruct a single super-resolution image from a stack of images associated to detectors. Each method has its pros and cons depending on the targeted application. In this paper, we review the most commonly used reconstruction methods and propose a SU RE approach to automatically estimate parameters and improve reconstruction. Methods described in this paper are available in an open source software

Pratiques du corps en médecine de la douleur (la douleur, la femme et le sacré)

La subjectivité, l'imaginaire, le mystère, la féminité, la pensée religieuse, sont autant d'éléments dont la mise à distance-a servi à construire la biomédecine telle qu'on la connaît aujourd'hui, son système de valeur propre, ses rites, ses représentations. De ce point de vue, la médecine de la douleur est originale. Elle impose en théorie au praticien de se remettre en question vis à vis de ces mises à distance. Qu'en est-il en pratique? Quelles sont les conséquences de ce renouveau pour la prise en charge des patientes appelées 'hystériques' ? Matériel et méthode: L'anthropologie de la santé et du corps constitue le principal cadre de référence théorique de ce travail, qui emprunte également certains outils à l'interactionnisme. il débute par une mise en perspective historique : histoire des rapports entre la médecine et la douleur, entre la médecine et les femmes, et histoire du terme 'hystérie'. Les techniques de recueil et d'analyse de données sont ensuite empruntées aux méthodologies qualitatives en sciences sociales: Ce travail est principalement le fruit d'une enquête de terrain de six mois en observation participante au Centre de Traitement de la Douleur de Nantes, et d'entretiens avec divers praticiens engagés dans la lutte contre la douleur . Résultats: La plainte douloureuse est bien envisagée dans ses diverses dimensions : subjective, chargée de croyances, herméneutique, rituelle. Les pratiques sont organisées autour de cette multidimensionnalité du phénomène douleur. Une part de mystère est respectée, grâce en particulier à la double tutelle que la médecine et la psychologie exercent sur cette discipline, à la divergence et à la complémentarité de leurs points de vue. Cet espace de mystère est l'occasion d'un questionnement épistémologique, concernant la légitimité de la psychologie et de la médecine à définir l'humain. Il apparaît que l'interaction médecin-patient autour de la plainte douloureuse est l'occasion d'une initiation rituelle, pour le patient, mais aussi dans une certaine mesure pour le médecin, et plus généralement qu'elle recouvre une dimension religieuse implicite. Les femmes, le maternel et le féminin occupent dans cette médecine une place différente de celle que la médecine leur reconnaît habituellement, ce qui n'est peut-être pas sans rapport avec le respect d'un part de mystère. Conclusion: Au terme de ce travail, qui constitue la première étape d'une thèse de sciences humaines, il apparaît que la pratique de cette médecine en suit bien les orientations théoriques, malgré de fortes résistances collectives et individuelles. Ses praticiens se positionnent en particulier comme les artisans privilégiés d'une réconciliation entre la médecine et le féminin qui est susceptible de bénéficier aux patientes dites hystériques. Il sera nécessaire de poursuivre la conceptualisation de ce travail en lien avec les travaux concernant les imaginaires féminins et masculins.NANTES-BU Médecine pharmacie (441092101) / SudocSudocFranceF

On the role of aurora-A in centrosome function.

International audienceMammalian aurora-A belongs to a multigenic family of mitotic serine/threonine kinases comprising two other members: aurora-B and aurora-C. In this review we will focus on aurora-A that starts to localize to centrosomes only in S phase as soon as centrioles have been duplicated, the protein is then degraded in early G1. Works in various organisms have revealed that the kinase is involved in centrosome separation, duplication and maturation as well as in bipolar spindle assembly and stability. Aurora kinases are found in all organisms in which their function has been conserved throughout evolution, namely the control of chromosome segregation. In human, aurora-A has focused a lot of attention, since its overexpression has been found to be correlated with the grade of various solid tumours. Ectopic kinase overexpression in any culture cell line leads to polyploidy and centrosome amplification. However, overexpression of aurora-A in particular cell lines such as NIH3T3 is sufficient to induce growth on soft agar. Those transformed cells form tumours when implanted in immunodeficient mice, indicating that the kinase is an oncogene

Targeted Laser Ablation in the Embryo of Saccharina latissima

International audienceIn Saccharina latissima, the embryo develops as a monolayered cell sheet called the lamina or the blade. Each embryo cell is easy to observe, readily distinguishable from its neighbors, and can be individually targeted. For decades, laser ablation has been used to study embryo development. Here, a protocol for cell-specific laser ablation was developed for early embryos of the brown alga S. latissima. The presented work includes: (1) the preparation of Saccharina embryos, with a description of the critical parameters, including culture conditions, (2) the laser ablation settings, and (3) the monitoring of the subsequent growth of the irradiated embryo using time-lapse microscopy. In addition, details are provided on the optimal conditions for transporting the embryos from the imaging platform back to the lab, which can profoundly affect subsequent embryo development. Algae belonging to the order Laminariales display embryogenesis patterns similar to Saccharina; this protocol can thus be easily transferred to other species in this taxon

A picture on the IFR140 microscopy facility

PosterThe ever growing needs to visualize and characterize biological systems leads to a constant increasing demand in imaging techniques. In order to offer to the scientific community an up to date technology and keeping in mind the high cost levels of those equipments, a common microscopy facility has been set up in Rennes, within a federative structure called IFR 140. The facility offers a large panel of widefield fluorescence as well as confocal imaging systems and a micro-injection system. (http://microscopie.univ-rennes1.fr/) Two engineers are in charge of the equipment, technological developments and survey; moreover they organize training sessions towards demanding scientists and finally offer advice for experimental design and result analysis. Two scientists assume the interaction with the scientific community and propose strategic developments so as to constantly improve the facility's performance. In the context of the 11th scientific meeting of “Réseau LARC-Neurosciences” we take the opportunity to present you our facility and to favour interplay with scientists for whom microscopy is an invaluable tool