| styloid process of radius | A thick, pointed, palpable projection on the lateral side of the distal extremity of the radius. Synonym: processus styloideus radii. (05 Mar 2000) |
|---|---|
| syndrome, thrombocytopenia-absent radius | See Syndrome, TAR. (12 Dec 1998) |
| interosseous border of radius | The ridge along the medial side of the radius to which is attached the interosseous membrane. Synonym: margo interosseus radii. (05 Mar 2000) |
| orbicular ligament of radius | The ligament that encircles and holds the head of the radius in the radial notch of the ulna, forming the proximal radioulnar joint and enabling pronation/supination of forearm; receives the radial collateral ligament of the elbow. Synonym: ligamentum annulare radii, ligamentum orbiculare radii, orbicular ligament of radius. (05 Mar 2000) |
| thrombocytopenia-absent radius syndrome | <syndrome> Tar stands for thrombocytopenia (low blood platelets) and aplasia (absence) of the radius (the long bone on the thumb-side of the forearm), features characterizing this syndrome. There is phocomelia (flipper-limb) with the thumbs always present. The fibula (the smaller bone in the lower leg) is often absent. The risk of bleeding from too few platelets is high in early infancy but lessens with age. The condition is inherited in an autosomal recessive trait with one gene (on a non-sex chromosome) coming from each parent to the tar child. Alternative names include thrombocytopenia-absent radius syndrome, radial aplasia-thrombocytopenia syndrome, and tetraphocomelia-thrombocytopenia syndrome. (12 Dec 1998) |
| effective collision radius | <radiobiology> Effective size of a particle equal to the square root of (cross-section/pi). Determines the effective range of interaction of the particle. (09 Oct 1997) |
| tuberosity of radius | An oval projection from the medial surface of the radius just distal to the neck, giving attachment on its posterior half to the tendon of the biceps. Synonym: tuberositas radii, bicipital tuberosity, tuber radii, tuberosity of radius. (05 Mar 2000) |
| finite larmor radius | (FLR) In many plasma theories the size of the Larmor radius (or gyroradius) is assumed to be negligibly small, or infinitesimal. Different effects occur when the size of the Larmor radius is finite and needs to be considered. (09 Oct 1997) |
| larmor radius | <radiobiology> The radius of the path of a charged particle moving in a magnetic field (and transverse to the field lines). Synonym: gyroradius, cyclotron radius. (09 Oct 1997) |
| receptors, cytoplasmic and nuclear | Proteins in the cytoplasm or nucleus that specifically bind signalling molecules and trigger changes which influence the behaviour of cells. The major groups are the steroid hormone receptors, which usually are found in the cytoplasm, and the thyroid hormone receptors, which usually are found in the nucleus. Receptors, unlike enzymes, generally do not catalyze chemical changes in their ligands. (12 Dec 1998) |
| Remak's nuclear division | <cell biology> An unusual form of nuclear division, in which the nucleus simply constricts, rather like a cell without chromosome condensation or spindle formation. Partitioning of daughter chromosomes is haphazard. Observed in some Protozoa. (18 Nov 1997) |
| Pelger-Huet nuclear anomaly | Congenital inhibition of lobulation in the nuclei of neutrophilic leukocytes; most cells present band or bilobulate appearance, and only an occasional cell is trilobed; it is not associated with disease, but may be confused with leukocyte "shift to left"; autosomal dominant inheritance. (05 Mar 2000) |
| ribonucleoproteins, small nuclear | Highly conserved nuclear RNA-protein complexes that function in RNA processing in the nucleus, including pre-mRNA splicing and pre-mRNA 3'-end processing in the nucleoplasm. The u3 snrnp is localised in the nucleolus, where it aligns into base pairs with the 28s rrna precursor in a still unidentified region and functions in pre-rrna processing. The u7 snrnp aligns into base pairs with a conserved sequence in the 3'-end of histone pre-mRNA and is an essential cofactor for the cleavage that creates the mature nonadenylated 3'-end. (12 Dec 1998) |
| RNA, heterogeneous nuclear | Nuclear nonribosomal RNA larger than about 1000 nucleotides, the mass of which is rapidly synthesised and degraded within the cell nucleus. Some heterogeneous nuclear RNA may be a precursor to mRNA. However, the great bulk of total hnrna hybridises with nuclear DNA rather than with mRNA. (12 Dec 1998) |
| RNA, nuclear | RNA molecules found in the nucleus either associated with chromosomes or in the nucleoplasm. (12 Dec 1998) |