| signal recognition particle | A complex between a 7S RNA and six proteins. SRP binds to the nascent polypeptide chain of eukaryotic proteins with a signal sequence and halts further translation until the ribosome becomes associated with the rough endoplasmic reticulum. One of the SRP proteins (srp54) binds GTP and in association with 7SRNA and srp19 has GTPase activity. (18 Nov 1997) |
|---|---|
| signal recognition particle receptor | Receptor for the signal recognition particle (SRP) found in the membrane of the endoplasmic reticulum. Also called docking protein. Heterodimeric, both protomers having GTP binding capacity, though dissimilar binding sites. Not until the complex of SRP, ribosome, message and nascent polypeptide chain binds to the SRP receptor is the block to further chain elongation released and concurrently the SRP is released, leaving the ribosome attached to the endoplasmic reticulum membrane. Cotranslational transport of the polypeptide delivers it into the lumen of the ER. (18 Nov 1997) |
| dual recognition hypothesis | An outmoded hypothesis that is known to be incorrect now that the structure of the T-cell receptor is known. The proposal was that viral (and some chemical) antigens were recognised in association with histocompatibility antigens by separate receptors on the T-cell. The generation of cytotoxic T-cells was by association with Class I MHC antigens, of T helper cells by association with Class II MHC antigens. See: altered self hypothesis. (18 Nov 1997) |
| airspace-filling pattern | Cloudy to dense opacities, obscuring vascular markings, on chest radiographs. Synonym: airspace-filling pattern. (05 Mar 2000) |
| airway pattern | Chest radiographic appearance of thickened bronchial walls, bronchiectasis, bronchiolitis, or acinar consolidation. (05 Mar 2000) |
| alveolar pattern | Cloudy to dense opacities, obscuring vascular markings, on chest radiographs. Synonym: airspace-filling pattern. (05 Mar 2000) |
| A-pattern strabismus | Strabismus in which esotropia is more marked in looking upward than downward, strabismus in which exotropia is more marked on looking downward than upward. Synonym: A-pattern strabismus. (05 Mar 2000) |
| axial pattern flap | A flap that includes a direct specific artery within its longitudinal axis. Synonym: arterial flap. (05 Mar 2000) |
| ballerina-foot pattern | A vigorous posteromedial contraction of the left ventricle coupled with convexity anteriorly sometimes resulting from poor contraction of the opposing anterior wall; it is the most frequent dyssynergy observed in the prolapsed mitral valve leaflet syndrome (even with a normal anterior wall) and produces a configuration of angiographic dye in the right anterior oblique projection resembling a ballerina's foot; sometimes called dancer's foot malformation. (05 Mar 2000) |
| banding pattern | <genetics> Chromosomes stained with certain dyes, commonly quinacrine (Q banding) or Giemsa (G banding), show a pattern of transverse bands of light and heavy staining that is characteristic for the individual chromosome. The basis of the differential staining, which is the same in most tissues, is not understood: each band represents 5-10% of the length, about 10exp7 base pairs, although this is not true for polytene chromosomes in Drosophila that show more than 4000 bands. (18 Nov 1997) |
| butterfly pattern | Bilateral, symmetric, pulmonary alveolar opacities sparing the periphery, on chest radiographs; usually caused by pulmonary oedema. (05 Mar 2000) |
| male pattern alopecia | The most common form of androgenic alopecia, seen in men as receding frontal and bilateral triangular temple hair lines, and a balding patch on the vertex, which may progress to complete alopecia. Synonym: male pattern baldness. (05 Mar 2000) |
| male pattern baldness | The most common form of androgenic alopecia, seen in men as receding frontal and bilateral triangular temple hair lines, and a balding patch on the vertex, which may progress to complete alopecia. Synonym: male pattern baldness. (05 Mar 2000) |
| random pattern flap | A flap in which the pedicle blood supply is derived randomly from the network of vessels in the area, rather than from a single longitudinal artery as in an axial pattern flap. (05 Mar 2000) |
| pattern | 1. Anything proposed for imitation; an archetype; an exemplar; that which is to be, or is worthy to be, copied or imitated; as, a pattern of a machine. "I will be the pattern of all patience." (Shak) 2. A part showing the figure or quality of the whole; a specimen; a sample; an example; an instance. "He compares the pattern with the whole piece." (Swift) 3. Stuff sufficient for a garment; as, a dress pattern. 4. Figure or style of decoration; design; as, wall paper of a beautiful pattern. 5. Something made after a model; a copy. "The patterns of things in the heavens." (Heb. Ix. 23) 6. Anything cut or formed to serve as a guide to cutting or forming objects; as, a dressmaker's pattern. 7. A full-sized model around which a mold of sand is made, to receive the melted metal. It is usually made of wood and in several parts, so as to be removed from the mold without injuring it. A definable characteristic relationship between the members of any set of objects or actions; also, the set having a definable relationship between its members. Thus: the distribution of bomb or shell impacts on a target area, or of bullet holes in a target; a set of traits or actions that appear to be consistent throughout the members of a group or over time within a group, as behavioral pattern, traffic pattern, dress pattern Pattern box, chain, or cylinder, devices, in a loom, for presenting several shuttles to the picker in the proper succession for forming the figure. Pattern card. A set of samples on a card. A count-wheel. Origin: OE. Patron, F. Patron, a patron, also, a pattern. See Patron. Source: Websters Dictionary (01 Mar 1998) |