Anything that causes seizures to occur. Triggers include consumption of alcohol, withdrawal after heavy alcohol use, fever, lack of sleep, or other physiological or psychological stressors.
surface-enhanced laser desorption-ionization.
(sel′ding-ĕr) [Sven Ivar Seldinger, Swedish physician, 1921–1998] A method of percutaneous introduction of a catheter into a vessel. The vessel is located and a needle inserted. Once a good blood flow is obtained, a wire is threaded through the needle well into the vessel. The needle is then removed, and the catheter is threaded over the wire into the vessel. The wire helps the insertion of the catheter and guides it into the appropriate vessel. Once the catheter is positioned in the desired intravascular area, the wire is removed. Sterile technique is imperative.
Any of a group of cell surface molecules that influence the attachment and movement of white blood cells to other cells and to the lining of blood vessels, e.g., in inflammatory diseases and conditions.
P-s. An adhesion receptor molecule for white blood cells that functions during inflammation and tissue repair. Binding with P-selectin glycoprotein ligand 1, it controls the flow of white blood cells and their adhesion to blood vessel walls. It is viewed as a key factor in thrombosis.
(sĕ-lek′shŏn) [L. selectio, choice] 1. A choosing or selecting; choice. 2. In biology, the factors that determine the reproductive ability of a certain genotype.
adverse s. The enrollment in a health plan of those who are sicker or use more health care services than the general population.
artificial s. The breeding of plants or animals to enhance desired characteristics.
clonal s. 1. The process by which T lymphocytes with receptors that react to autoantigens are destroyed in the thymus. 2. The increase of particular B or T lymphocyte clones after recognition of a specific antigen to which the body has been exposed. SEE: negative s.; clone.
natural s. A theory of evolution proposed by Charles Darwin stating that the genotypes best adapted to their environment have a tendency to survive and reproduce.
negative s. The process by which immature T lymphocytes (thymocytes) with receptors for autoantigens are destroyed in the thymus. It is part of the mechanism that prevents autoimmune diseases. SEE: autoimmunity.
sexual s. 1. The choice of the gender of an offspring through methods that increase the likelihood of conceiving either a girl or a boy. 2. A theory originated to account for differences in secondary sex characteristics between male and female animals (including humans). It assumes that individuals preferentially mate with individuals ...