vitamin glossary T

thymus- a glandular structure of largely lymphoid tissue that functions in the development of the body's immune system, located in the upper chest or at the base of the neck.

tissue culture- the growth of cells as tissue in a special medium. While the properties of tissue in culture differs in some ways from tissues in the body, particularly in lacking many of the protective mechanisms of the whole animal, tissue culture research can provide valuable data at relatively low cost.

tonic- often used in traditional Chinese Medicine and Ayurvedic medicine, tonics are often taken as a preventative measure to nurture and enliven.

tonsillitis- an inflammation of the tonsil.

topical- applied externally.

toxic- poisonous. Toxic effects of a substance are dependent on the dose. At sufficiently high doses, air, water, anything, even the inert gas helium, is toxic. (High pressure helium causes lethal convulsions even when adequate oxygen is present.)

transformation- the process whereby a normal cell turns into a cancer cell. This process involves cellular de different action.

Tricarboxylic Acid Cycle- See Citric Acid Cycle.

triglycerides- a combination of glycerol with three to five different fatty acids.

triplet oxygen- oxygen in an excited electronic state in which the oxygen atom has two single electrons in two high energy orbitals with their spins in the same direction. Because of the unpaired electrons, triplet oxygen is even more highly reactive than singlet oxygen, and can cause biological damage. Under physiological conditions, triplet oxygen very rapidly decays to somewhat less energetic singlet oxygen. Beta-carotene and other carotenoids quench both triplet and cited triplet state (it has two unpaired electrons), which is why it is both a good free radical initiator and scavenger.

tumor- an abnormal mass of tissue that is not inflammatory, arises without obvious cause from cells, and possesses no physiological function.

tumorigenesis- the process of initiating a tumor.