19 research outputs found

    Expression and function of CD40 on Hodgkin and Reed-Sternberg cells and the possible relevance for hodgkin's disease

    No full text
    CD40 was originally described as a B-cell-restricted antigen and was subsequently found to be a member of the tumor necrosis factor (TNF) receptor superfamily. CD40 is also expressed on dendritic cells, thymic epithelium, monocytes, and some carcinoma cell lines, and plays a critical role in cell contact-dependent activation. Primary and cultured Hodgkin and Reed-Sternberg (H-RS) cells, the presumed malignant cells of Hodgkin's disease (HD); were found to express high levels of cell surface CD40. We found that recombinant CD40 ligand (CD40L) induced interleukin-8 (IL-8) secretion and enhanced IL-6, TNF, and lymphotoxin-alpha (LT-alpha/TNF-beta) release from cultured H-RS cells. These cytokines play a significant role in the clinical presentation and pathology of HD, a tumor of cytokine-producing cells. CD40L had no mitogenic activity for HD-derived cell lines. In contrast, CD40L enhanced expression of costimulatory molecules intracellular adhesion molecule-T and B7-1 on cultured H-RS cells, both of which are overexpressed on primary H-RS cells. In addition, CD40L induced a 40% to 60% reduction of the expression of the HD-associated CD30 antigen, another member of the TNF receptor superfamily. Primary and cultured H-RS cells express not only CD30, but also CD40. CD40L has pleiotropic biologic activities on H-RS cells, and the CD40-CD40L interaction might be a critical element in the deregulated cytokine network and cell contact-dependent activation cascade typical for HD

    Using the dynamic model of educational effectiveness to design strategies and actions to face bullying

    No full text
    This project investigates the impact of the dynamic approach to school improvement (DASI) aiming to help schools face and reduce bullying through integrating research on bullying with educational effectiveness research (EER). A network of approximately 15 schools in each participating country (i.e., Belgium, Cyprus, England, Greece, and The Netherlands) received support to use DASI in order to improve the functioning of school factors included in the dynamic model of educational effectiveness which are associated with reduction of bullying. The Revised Olweus Bully/Victim Questionnaire was administered to students of the experimental (n = 1461) and control (n = 1535) group at the beginning and at the end of the intervention. With the use of multilevel modelling techniques, it was found that schools which made use of DASI were able to reduce bullying at a significantly higher level than the schools of the control group. Implications for the development of effective policies and practices in reducing bullying are draw
    corecore