21 research outputs found
BiomĂ©canique de lâĂ©pithĂ©lium cornĂ©en: rĂ©sistance au stress et implications dans la cicatrisation et le remodelage
International audienceThe corneal epithelium is one of the first tissue barriers of the eye against the environment. In recent years, many studies provided better knowledge of its healing, its behavior and its essential role in the optical system of the eye. At the crossroads of basic science and clinical medicine, the study of the mechanical stresses applied to the cornea makes it possible to learn the behavior of epithelial cells and better understand ocular surface disease. We describe herein the current knowledge about the adhesion systems of the corneal epithelium and their resistance to mechanical stress. We will also describe the involvement of these mechanisms in corneal healing and their role in epithelial dynamics. Adhesion molecules of the epithelial cells, especially hemidesmosomes, allow the tissue cohesion required to maintain the integrity of the corneal epithelium against the shearing forces of the eyelids as well as external forces. Their regeneration after a corneal injury is mandatory for the restoration of a healthy epithelium. Mechanotransduction plays a significant role in regulating epithelial cell behavior, and the study of the epithelium's response to mechanical forces helps to better understand the evolution of epithelial profiles after refractive surgery. A better understanding of corneal epithelial biomechanics could also help improve future therapies, particularly in the field of tissue engineering.LâĂ©pithĂ©lium cornĂ©en constitue une des premiĂšres barriĂšres tissulaires de lâĆil face Ă lâenvironnement. Au cours des derniĂšres annĂ©es, de nombreuses recherches ont pu Ă©tudier sa cicatrisation, son comportement ainsi que son rĂŽle primordial dans le systĂšme optique oculaire. Au croisement de la science fondamentale et de la mĂ©decine clinique, lâĂ©tude des contraintes mĂ©caniques appliquĂ©es Ă la cornĂ©e permet dâapprĂ©hender le comportement des cellules Ă©pithĂ©liales et de mieux comprendre certaines pathologies de la surface oculaire. Nous dĂ©crivons ici lâĂ©tat actuel des connaissances sur les systĂšmes dâadhĂ©sion de lâĂ©pithĂ©lium cornĂ©en ainsi que sur leur rĂ©sistance Ă un stress mĂ©canique. Nous dĂ©crirons aussi lâimplication de ces mĂ©canismes dans de la cicatrisation cornĂ©enne et leur rĂŽle dans la dynamique Ă©pithĂ©liale. Les molĂ©cules dâadhĂ©sion des cellules Ă©pithĂ©liales, en particulier les hĂ©midesmosomes, permettent une cohĂ©sion tissulaire nĂ©cessaire au maintien de lâintĂ©gritĂ© de lâĂ©pithĂ©lium cornĂ©en face aux forces de cisaillement des paupiĂšres et aux agressions extĂ©rieures. Leur rĂ©gĂ©nĂ©ration aprĂšs une lĂ©sion cornĂ©enne est nĂ©cessaire Ă la restauration dâun Ă©pithĂ©lium sain. La mĂ©canotransduction joue un rĂŽle non nĂ©gligeable dans la rĂ©gulation du comportement des cellules Ă©pithĂ©liales, et lâĂ©tude de la rĂ©action de lâĂ©pithĂ©lium aux forces mĂ©caniques aide Ă mieux comprendre lâĂ©volution des profils Ă©pithĂ©liaux Ă distance dâune chirurgie rĂ©fractive. Une meilleure comprĂ©hension de la biomĂ©canique de lâĂ©pithĂ©lium cornĂ©en pourrait aussi permettre dâamĂ©liorer les thĂ©rapeutiques futures en particulier dans le domaine de lâingĂ©nierie tissulaire
Le trabéculum : structure, fonction et implications cliniques. Une revue de la littérature
International audienceLe glaucome est une neuropathie optique cĂ©citante dont le principal facteur de risque est lâaugmentation de la pression intraoculaire (PIO). Le trabĂ©culum, au niveau de lâangle iridocornĂ©en, constitue la principale voie de drainage de lâhumeur aqueuse (HA) hors de lâĆil, et son dysfonctionnement est responsable dâune augmentation de la PIO. Le trabĂ©culum est une structure tridimensionnelle fenĂȘtrĂ©e complexe composĂ©e de cellules trabĂ©culaires intriquĂ©es dans une organisation multicouche de matrice extracellulaire (MEC). Lâobjectif de cette revue de la littĂ©rature est de fournir un Ă©tat des lieux de la connaissance sur le trabĂ©culum et sa physiopathologie dans le glaucome. Ainsi, nous prĂ©senterons les bases anatomiques et cellulaires au centre de la rĂ©gulation de la rĂ©sistance Ă lâĂ©coulement de lâHA, les mĂ©canismes physiopathologiques dâaltĂ©ration trabĂ©culaire impliquĂ©s dans les diffĂ©rents types de glaucomes, ainsi que les stratĂ©gies thĂ©rapeutiques existantes ou en dĂ©veloppement ciblant le trabĂ©culum
On the task of making social inquiry aligned to caregiving: An invitation to debate.
This paper is designed as an invitation to debate the value of research and writing on social suffering in relation to practices of caregiving. It offers a brief account of the origins and development of social suffering as a concern for social inquiry. Henry Mayhew and Jane Addams are profiled in terms of their pioneering roles as social researchers heavily preoccupied with problems of social suffering. The contrast between Henry Mayhew's frustrated attempts at caregiving and Jane Addams success in instituting the pedagogy of caregiving in the work of Hull House is set up for analysis. These examples are used to issue an invitation to readers to question the cultural and institutional circumstances that make possible forms of social inquiry that recognise caregiving both as a means to social understanding and as an aim for social research in practice