Biomaterial Database

Reevaluating current models of thymic involution. 2005

Encarnacion Montecino-Rodriquez, and Hyeyoung Min, and Kenneth Dorshkind

Department of Pathology and Laboratory Medicine 173216, David Geffen School of Medicine at UCLA, 10833 Le Conte Avenue, Los Angeles, CA 90095, USA.

It is generally accepted that thymic involution commences, or at least accelerates, at puberty due to increases in sex steroid and declines in growth hormone production. As a result of these hormonal changes, the development of the most immature intrathymic progenitors is blocked. However, aspects of this model are now being questioned. The present chapter re-evaluates a number of findings on which traditional models of thymic involution are based and reviews new data that, taken together, indicate a need to revise current views of thymic involution.

UI	MeSH Term	Description	Entries
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000375	Aging	The gradual irreversible changes in structure and function of an organism that occur as a result of the passage of time.	Senescence,Aging, Biological,Biological Aging
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D013601	T-Lymphocytes	Lymphocytes responsible for cell-mediated immunity. Two types have been identified - cytotoxic (T-LYMPHOCYTES, CYTOTOXIC) and helper T-lymphocytes (T-LYMPHOCYTES, HELPER-INDUCER). They are formed when lymphocytes circulate through the THYMUS GLAND and differentiate to thymocytes. When exposed to an antigen, they divide rapidly and produce large numbers of new T cells sensitized to that antigen.	T Cell,T Lymphocyte,T-Cells,Thymus-Dependent Lymphocytes,Cell, T,Cells, T,Lymphocyte, T,Lymphocyte, Thymus-Dependent,Lymphocytes, T,Lymphocytes, Thymus-Dependent,T Cells,T Lymphocytes,T-Cell,T-Lymphocyte,Thymus Dependent Lymphocytes,Thymus-Dependent Lymphocyte
D013950	Thymus Gland	A single, unpaired primary lymphoid organ situated in the MEDIASTINUM, extending superiorly into the neck to the lower edge of the THYROID GLAND and inferiorly to the fourth costal cartilage. It is necessary for normal development of immunologic function early in life. By puberty, it begins to involute and much of the tissue is replaced by fat.	Thymus,Gland, Thymus,Glands, Thymus,Thymus Glands
D018448	Models, Immunological	Theoretical representations that simulate the behavior or activity of immune system, processes, or phenomena. They include the use of mathematical equations, computers, and other electrical equipment.	Immunological Models,Immunologic Model,Model, Immunologic,Immunologic Models,Immunological Model,Model, Immunological,Models, Immunologic