| AHA | acetohydroxamic acid; acquired hemolytic anemia; acute hemolytic anemia; American Heart Association;... |
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| IA | ibotenic acid; immune adherence; immunoadsorbent; immunobiologic activity; impedance angle; indolami... |
| LA50 | total body surface area of burn that will kill 50% of patients (lethal area) |
| BAIF | bile acid independent flow |
| BIPLED | bilateral, independent, periodic, lateralized epileptiform discharge |
| thymus and parathyroids, hypoplasia of | See third and fourth pharyngeal pouch syndrome. (12 Dec 1998) |
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| thymus-dependent zone | <anatomy> Mid cortical region of lymph node, area that is particularly depleted of T lymphocytes in thymectomised animals and is referred to as the thymus dependent area. (18 Nov 1997) |
| thymus derived lymphocyte | <haematology, immunology> A class of lymphocytes, so called because they are derived from the thymus and have been through thymic processing. Involved primarily in controlling cell-mediated immune reactions and in the control of B-cell development. The T-cells coordinate the immune system by secreting lymphokine hormones. There are 3 fundamentally different types of t cells : helper, killer, and suppressor. Each has many subdivisions. T-cells are also called t lymphocytes. They bear T-cell antigen receptors (CD3) and lack Fc or C3b receptors. Major T-cell subsets are CD4 (mainly helper cells) and CD8 (mostly cytotoxic or suppressor T-cells). Uncontrolled proliferation of this type of cell gives rise to T-cell leukaemia/lymphoma. (21 Jun 1999) |
| thymus extracts | Extracts of the thymus that contain specific, but uncharacterised factors or proteins with specific activities; three distinct substances are already known: thymotoxin, thymin and thymosin. (12 Dec 1998) |
| thymus gland | A bilaterally symmetric lymphoid organ situated in the anterior superior mediastinum. Each of its two lobes consists of an outer zone, the cortex, relatively rich in lymphocytes (thymocytes), and an inner zone, the medulla, relatively rich in epithelial cells. The thymus is the site of the production of T-lymphocytes. The thymus reaches its maximal development at about puberty and then undergoes a gradual process of involution resulting in a slow decline of immune function throughout adulthood. (12 Dec 1998) |
| thymus hormones | Humoral factors secreted by the thymus gland. They participate in the development of the lymphoid system and the maturation of the cellular immune response. (12 Dec 1998) |
| thymus hyperplasia | Enlargement of the thymus. A condition described in the late 1940's and 1950's as pathological thymic hypertrophy was status thymolymphaticus and was treated with radiotherapy. Unnecessary removal of the thymus was also practiced. It later became apparent that the thymus undergoes normal physiological hypertrophy, reaching a maximum at puberty and involuting thereafter. The concept of status thymolymphaticus has been abandoned. Thymus hyperplasia is present in two thirds of all patients with myasthenia gravis. (12 Dec 1998) |
| thymus treatment | Treatment of disease by administration of extracts of thymus gland. (05 Mar 2000) |
| lobules of thymus | Areas of thymic tissue 0.5 to 2 mm in diameter with a cortex and medulla. Synonym: lobuli thymi. (05 Mar 2000) |
| acoustic area | The floor of the lateral recess of the fourth ventricle, extending medially to the limiting sulcus and overlying the cochlear and vestibular nuclei of the rhombencephalon. Synonym: area acustica. (05 Mar 2000) |
| adaptive management area | Landscape units designated for development and testing of technical and social approaches to achieving desired ecological, economic, and other social objectives. (05 Dec 1998) |
| air quality maintenance area | Specific populated area where air quality is a problem for one or more pollutants (Portland-Vancouver, Salem, Eugene-Springfield, Medford-Ashland). (05 Dec 1998) |
| anterior intercondylar area of tibia | The broad depressed area between the tibial condyles anteriorly to which attach the anterior ends of the menisci and the anterior cruciate ligament. Synonym: area intercondylaris anterior tibiae. (05 Mar 2000) |
| aortic area | The region of the chest wall over the second right costal cartilage, where sounds produced at the aortic orifice are often best heard. (05 Mar 2000) |
| apical area | The area about the root end of a tooth. (05 Mar 2000) |