| A1 | aortic first sound |
|---|---|
| A2 | aortic second sound |
| A2-OS | aortic second sound, opening snap |
| ACS | acrocallosal syndrome; acrocephalosyndactyly; acute chest syndrome; acute confusional state; Alcon C... |
| AES | acetone-extracted serum; American Electroencephalographic Society; American Encephalographic Society... |
| Jewett sound | A short straight sound for dilating the anterior urethra. (05 Mar 2000) |
|---|---|
| first heart sound | Occurs with ventricular systole and is mainly produced by closure of the atrioventricular valves. (05 Mar 2000) |
| fourth heart sound | The sound produced in late diastole in association with ventricular filling due to atrial systole and related to reduced ventricular compliance. It is a low frequency oscillation that may be normal at older ages owing to a physiologic decline in ventricular compliance but is nearly always abnormal at younger ages if it is of high intensity or palpable. It is common in ventricular hypertrophy, particularly with hypertension, and is almost invariable during acute myocardial infarction. Fourth heart sounds may arise from the right or left ventricle or both. Synonym: atrial sound. (05 Mar 2000) |
| friction sound | The sound, heard on auscultation, made by the rubbing of two opposed serous surfaces roughened by an inflammatory exudate, or, if chronic, by nonadhesive fibrosis. Synonym: friction murmur, friction rub. (05 Mar 2000) |
| Le Fort sound | A curved sound threaded for a filiform bougie, used for dilation of urethral strictures in the male when small caliber or presence of false passages prevents safe passage of a standard sound or catheter. (05 Mar 2000) |
| aberrant complex | An anomalous electrocardiographic complex, more specifically an abnormal ventricular complex caused by abnormal intraventricular conduction of a supraventricular impulse. (05 Mar 2000) |
| activated complex | <chemistry> State of highest energy during a reaction. When reactants form the activated complex, bond breaking and bond formation is occurring. Synonym: transition state. (09 Jan 1998) |
| AIDS dementia complex | <immunology> A frequent cerebral condition in people with AIDS that results in the loss of cognitive capacity, affecting the ability to function in a social or occupational setting. Its cause has not been determined exactly, but may result from HIV infection of cells in the brain or an inflammatory reaction to such infection. (09 Oct 1997) |
| aids-related complex | A prodromal phase of infection with the human immunodeficiency virus (HIV). Laboratory criteria separating aids-related complex (arc) from aids include elevated or hyperactive B-cell humoral immune responses, compared to depressed or normal antibody reactivity in aids; follicular or mixed hyperplasia in arc lymph nodes, leading to lymphocyte degeneration and depletion more typical of aids; evolving succession of histopathological lesions such as localization of kaposi's sarcoma, signaling the transition to the full-blown aids. (12 Dec 1998) |
| alpha-keto acid dehydrogenase complex | See: alpha-keto acid dehydrogenase. Anaerobic dehydrogenase, an enzyme (usually a pyridinoenzyme) catalyzing the transfer of hydrogen from some metabolite to some acceptor molecule (e.g., NAD+, cytochrome) other than oxygen; e.g., lactate dehydrogenase's, isocitrate dehydrogenase's, and others in EC class 1, excluding those listed under aerobic dehydrogenase. (05 Mar 2000) |
| alpha-ketoglutarate dehydrogenase complex | alpha-ketoglutarate dehydrogenase |
| amygdaloid complex | Almond-shaped group of basal nuclei anterior to the inferior horn of the lateral ventricle of the brain, within the temporal lobe. The amygdala is part of the limbic system. (12 Dec 1998) |
| anomalous complex | A complex in the electrocardiogram differing significantly from the physiologic type in the same lead. (05 Mar 2000) |
| antennal complex | <cell biology> Light harvesting complexes (LHC) of protein and pigment in or on photosynthetic membranes of bacteria are organised into arrays, called antennae. They transfer photon energy to reaction centres. (18 Nov 1997) |
| antennapedia complex | A set of mutations that cause developmental defects in the limbs and appendages of the fruit fly Drosophila melanogaster, such as the development of legs (-pedia) in the places where antennae are supposed to be. (09 Oct 1997) |