Although autoimmune disorders are a significant source of morbidity and mortality in older individuals, the mechanisms governing age-associated increases in susceptibility remain incompletely understood. Central T cell tolerance is mediated through presentation of self-antigens by cells constituting the thymic microenvironment, including epithelial cells, dendritic cells, and B cells. Medullary...

OBJECTIVES Recent studies have shown the usefulness of (18)F-fluorodeoxyglucose positron emission tomography (FDG-PET) in differentiating between World Health Organization (WHO) histological subgroups of thymic epithelial tumours. However, these reports may have included many advanced cases of these lesions (Masaoka stage III or IV) of high-risk subtypes. The objective of our present study was ...

Thymic epithelial tumours represent a wide range of anatomical, clinical, histological and molecular malignant entities that may be aggressive and difficult to treat. The histopathological classification distinguishes thymomas from thymic carcinomas. Thymomas may be associated with autoimmune disorders. The management of thymic epithelial tumours is a paradigm of co-operation between clinicians...

The thymus is a central lymphoid organ that is responsible for T-lymphocyte development and maturation. Through negative and positive selection, lymphoid progenitor cells, which initiate from the bone marrow, develop into mature T cells in the thymus, and are subsequently involved in peripheral cell immunity. It has been reported that the Wnt signaling pathway exists widely in thymic epithelial...

OBJECTIVE Neurotrophins are known to exert a variety of pleiotropic responses in different target tissues, but little is known about their effect on thymic epithelial tumors. Therefore, we analyzed the expression of neurotrophin receptors in surgically resected thymic epithelial tumors and evaluated their clinical relevance. METHODS The expression of neurotrophin receptors (Trk-A, Trk-B, Trk-...

Colonization of the thymic rudiment during development is initiated before vascularization so that hemopoietic precursors must leave the pharyngeal vessels and migrate through the perithymic mesenchyme to reach the thymus, suggesting that they may be responding to a gradient of chemoattractant factors. We report that diffusible chemoattractants are produced by MHC class II+ epithelial cells of ...