Tini, Jos??, Shabbir : trabajadores de diez a??os

Resumen del documento

Ad??u a les armes : campanya per al control de les armes lleugeres. 'Adi??s a las armas : campa??a para el control de las armas ligeras'

Resumen del documento en catal??n

Semana de la solidaridad con la poblaci??n refugiada del mundo : Alejandro, Mar??a Luisa

Algunos documentos no tienen ISBN. Hay ejemplares duplicados de parte del material que contiene la caja. T??tulo tomado de la caja. Premios Nacionles a la Educaci??n y sociedad 1995

Recetas para un mundo m??s justo

Se describe una experiencia desarrollada con alumnos de Primaria en el marco del proyecto Conectando Mundos, organizado por Oxfam Interm??n y la Red de Educadores y Educadoras para una Ciudadan??a Global. En el art??culo se explican los objetivos del proyecto, c??mo las TIC ayudan a conseguirlos y la participaci??n del colegio p??blico ??ngel Campano, de Gines (Sevilla). Se exponen las fases del trabajo en este curso dedicado al problema del hambre y las actividades que realizan los alumnos.

T-cell reprogramming through targeted CD4-coreceptor and T-cell receptor expression on maturing thymocytes by latent Circoviridae family member porcine circovirus type 2 cell infections in the thymus

Although porcine circovirus type 2 (PCV2)-associated diseases have been evaluated for known immune evasion strategies, the pathogenicity of these viruses remained concealed for decades. Surprisingly, the same viruses that cause panzootics in livestock are widespread in young, unaffected animals. Recently, evidence has emerged that circovirus-like viruses are also linked to complex diseases in humans, including children. We detected PCV2 genome-carrying cells in fetal pig thymi. To elucidate virus pathogenicity, we developed a new pig infection model by in vivo transfection of recombinant PCV2 and the immunosuppressant cofactor cyclosporine A. Using flow cytometry, immunofluorescence and fluorescence in situ hybridization, we found evidence that PCV2 dictates positive and negative selection of maturing T cells in the thymus. We show for the first time that PCV2-infected cells reside at the corticomedullary junction of the thymus. In diseased animals, we found polyclonal deletion of single positive cells (SPs) that may result from a loss of major histocompatibility complex class-II expression at the corticomedullary junction. The percentage of PCV2 antigen-presenting cells correlated with the degree of viremia and, in turn, the severity of the defect in thymocyte maturation. Moreover, the reversed T-cell receptor/CD4-coreceptor expression dichotomy on thymocytes at the CD4(+)CD8(interm) and CD4SP cell stage is viremia-dependent, resulting in a specific hypo-responsiveness of T-helper cells. We compare our results with the only other better-studied member of Circoviridae, chicken anemia virus. Our data show that PCV2 infection leads to thymocyte selection dysregulation, adding a valuable dimension to our understanding of virus pathogenicity.