| OA | obstructive apnea; occipital artery; occipito-anterior; occiput anterior; octanoic acid; ocular albi... |
|---|---|
| OA/BVM | oral airway/bag-valve-mask |
| OAS | old age security; oral allergy syndrome; osmotically active substance |
| OAW | oral airways |
| OC | obstetrical conjugate; occlusocervical; office call; on call; only child; optic chiasma; oral contra... |
| antigenic complex | A composite of different antigenic structures, such as a cell or a bacterium, or, by extension, a molecule containing two or more determinant groups of different antigenic specificities. (05 Mar 2000) |
|---|---|
| apical complex | A set of anterior structures that characterise one or several developmental stages of members of the protozoan phylum Apicomplexa; includes the following structures, visible by electron microscopy: polar ring, conoid, rhoptries, micronemes, and subpellicular tubules. (05 Mar 2000) |
| atrial complex | P wave in the electrocardiogram. Synonym: auricular complex. (05 Mar 2000) |
| auricular complex | P wave in the electrocardiogram. Synonym: auricular complex. (05 Mar 2000) |
| avian leukaemia-sarcoma complex | A term applied to a group of transmissible virus-induced diseases of chickens causing sarcoma, myeloblastosis, erythroblastosis, leukosis, osteopetrosis, and lymphomatosis. These agents are closely related viruses (avian leukosis-sarcoma virus) causing prolferation of immature erythroid, myeloid, or lymphoid cells, a division of the RNA tumour viruses (subfamily Oncovirinae) causing the avian leukosis-sarcoma complex of diseases; the viruses are subgrouped according to antigenic characteristics and growth in defined types of tissue culture cells. Synonym: avian erythroblastosis virus, avian leukosis-sarcoma virus, avian lymphomatosis virus, avian myeloblastosis virus, avian sarcoma virus, fowl erythroblastosis virus, fowl lymphomatosis virus, fowl myeloblastosis virus. (05 Mar 2000) |
| b c1 complex | <biochemistry> A part of the mitochondrial electron transport chain that accepts electrons from ubiquinone and passes them on to cytochrome C. The b/c1 complex consists of 2 cytochromes. (18 Nov 1997) |
| b-complex vitamin | <biochemistry> A group of vitamins that includes: B1(thiamin), B2 riboflavin), B3 (niacin), B6(pyridoxine), B12 (cobalamin) and folate. (24 Mar 1998) |
| binary complex | A noncovalent complex of two molecules; often referring to the enzyme-substrate complex in an enzyme-catalyzed reaction. Compare: central complex, Michaelis complex. Synonym: enzyme-substrate complex. (05 Mar 2000) |
| bithorax complex | <genetics, molecular biology> A group of homeotic mutations of Drosophila that map to the bithorax region on chromosome III. The mutations all cause the third thoracic segment to develop like the second thoracic segment to varying extents. The genes of the bithorax complex are thought to determine the differentiation of the posterior thoracic segments and the abdominal segments. (18 Nov 1997) |
| brain wave complex | A specific combination of fast and slow electroencephalographic activity that recurs frequently enough to be identified as a discrete phenomenon. (05 Mar 2000) |
| brother complex | Extreme envy or jealousy of a brother, leading to hatred. Synonym: brother complex. Origin: Cain, biblical personage (05 Mar 2000) |
| Cain complex | Extreme envy or jealousy of a brother, leading to hatred. Synonym: brother complex. Origin: Cain, biblical personage (05 Mar 2000) |
| MAC complex | complement |
| major histocompatabilty complex | <immunology> A cluster of genes on chromosome 6 concerned with antigen production and critical to transplantation. The MHC includes the human leukocyte antigen (HLA) genes. (12 Dec 1998) |
| major histocompatibility complex | The set of gene loci specifying major histocompatibility antigens, for example HLA in man, H 2 in mice, RLA in rabbits, RT 1 in rats, DLA in dogs, SLA in pigs, etc. Acronym: MHC (18 Nov 1997) |