| senile nephrosclerosis | Patchy atrophic scarring of the kidney due to arteriosclerotic narrowing of the lumens of large branches of the renal artery, occurring in old or hypertensive persons and occasionally causing hypertension. Synonym: arterionephrosclerosis, senile nephrosclerosis. (05 Mar 2000) |
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| senile osteomalacia | Osteoporosis in the aged. (05 Mar 2000) |
| senile plaque | <neurology> Characteristic feature of the brains of Alzheimer's patients and aged monkeys, consisting of a core of amyloid fibrils surrounded by dystrophic neurites. The principal component of amyloid fibrils in senile plaques is B/A4, a peptide of about 4 kD that is derived from the larger amyloid precursor protein (APP). The B/A4 sequence is located near the C terminus of APP. (18 Nov 1997) |
| senile plaques | Microscopic argyrophilic masses composed of fragmented axon terminals and dendrites surrounding a core of amyloid. They are seen in small amounts in the cerebral cortex of normal elderly people and in larger amounts in those with alzheimer disease. (12 Dec 1998) |
| senile psychosis | Mental disturbance occurring in old age and related to degenerative cerebral processes. (05 Mar 2000) |
| senile retinoschisis | Retinoschisis occurring most often in the elderly and affecting the outer plexiform layer; it begins in the extreme inferotemporal periphery and is not significantly progressive; vision usually is good. (05 Mar 2000) |
| senile sebaceous hyperplasia | Hyperplasia of mature sebaceous glands, forming a nodule on the skin of the face or forehead in elderly persons. (05 Mar 2000) |
| senile tremor | An essential tremor that becomes symptomatic in elderly adults. (05 Mar 2000) |
| senile wart | <dermatology> A skin lesion that is abnormally sensitive to the effects of ultraviolet light (sunlight). Thought to be a precancerous skin lesion that is more common in the fair-skinned or elderly individual. Approximately 20% of these skin lesions will develop into squamous cell carcinoma. Prevention includes the use of sun screen agents and the avoidance of drugs (for example tetracyclines) known to cause photosensitivity reactions. Usually a discreet slightly raised, red or pink lesion located on a sun exposed surface. Texture may appear as rough, gritty or scaly. Growths may be biopsied to look for cancer or removed via cryotherapy or electrical cautery. Some topical agents may be used to promote peeling. (27 Sep 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) |