| giant osteoid osteoma | A benign, painful, tumour of bone characterised by the formation of osteoid tissue, primitive bone and calcified tissue. It occurs frequently in the spine of young persons. (12 Dec 1998) |
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| osteoid | <pathology> Uncalcified bone matrix, the product of osteoblasts. Consists mainly of collagen, but has osteonectin present. (18 Nov 1997) |
| osteoid osteoma | <radiology> M more than F, 15 - 30 years of age, lucent nidus with thickened cortex, metaphyseal, femur, talus, tibia, patella, rarely spine, never skull or clavicle, pain at night, relievey be inflammatory rather than neoplastic, treatment: leave it (disappears in 4-6 yrs), or remove nidus, Differential diagnosis: TB abscess, chronic osteo (Brodie abscess), sclerosing osteomyelitis of Garre (12 Dec 1998) |
| osteoid tissue | Osseous tissue prior to calcification. (05 Mar 2000) |
| osteoma, osteoid | Benign circumscribed tumour of spongy bone occurring especially in the bones of the extremities and vertebrae, most often in young persons. (12 Dec 1998) |
| blood relative | A relative of a person sharing some of the sources from which genes are derived. These will include many of the genes that operate in the blood and its constituents but no special importance attaches to the blood as a vehicle of inheritance. Spouses are not ordinarily blood relatives and when they are, the marriage is consanguineous and carries a higher risk than average of progeny homozygous by descent from ancestors in common. Such marriages are discouraged and within certain degrees of kindred may be illegal. Origin: a folk metaphor of breeding (05 Mar 2000) |
| relative | One who, or that which, relates to, or is considered in its relation to, something else; a relative object or term; one of two object or term; one of two objects directly connected by any relation. Specifically: A person connected by blood or affinity; strictly, one allied by blood; a relation; a kinsman or kinswoman. "Confining our care . . . To ourselves and relatives." . A relative prnoun; a word which relates to, or represents, another word or phrase, called its antecedent; as, the relatives " who", "which", "that". Source: Websters Dictionary (01 Mar 1998) |
| relative accommodation | Quantity of accommodation required for single binocular vision for any specified distance, or for any particular degree of convergence. (05 Mar 2000) |
| relative afferent pupillary defect | An asymmetry of the pupillomotor input between the two eyes; tested by alternating the light from one eye to the other and comparing the direct light reactions. (05 Mar 2000) |
| relative aperture | <microscopy> The ratio of the focal length of a lens to the diameter of its entrance pupil. This gives a number known as the f-number, usually written f:8, f:16, etc. Thus, if the focal length is divided by the number 8, 16, etc., the result will be the diameter of the entrance pupil of the lens, or if the diaphragm of the lens is wide open it will be very nearly the diameter of the free aperture of the lens. See: F-number. (05 Aug 1998) |
| relative basal area | An estimate of basal area for trees, such as produced by the Bitterlich sampling technique. (09 Oct 1997) |
| relative biological effectiveness | The ratio of radiation dosages required to produce identical change based on a formula comparing other types of radiation with that of gamma or roentgen rays. (12 Dec 1998) |
| relative dehydration | Water deficit relative to content of solutes contributing effective osmotic pressure; a state of increased effective osmotic pressure of body fluids. (05 Mar 2000) |
| relative immunity | A modified, not completely effective resistance that results when there is a sort of "fluctuating equilibrium" between the defense mechanisms of the host and the infective agent. (05 Mar 2000) |
| relative incompetence | Imperfect closure of a cardiac valve, in consequence of excessive dilation of the corresponding cavity of the heart. (05 Mar 2000) |