| Barr body | Small dark staining inactivated X chromosome seen in female (XX) cells. According to the Lyon hypothesis, random inactivation occurs. (18 Nov 1997) |
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| Barr chromatin body | Condensed chromatin of the inactivated X chromosome in female mammals (Barr body). (18 Nov 1997) |
| Barr, Murray | <person> Canadian microanatomist, *1908. See: Barr chromatin body. (05 Mar 2000) |
| Barr, Yvonne | <person> English virologist, *1932. See: Epstein-Barr virus. (05 Mar 2000) |
| barracouata | 1. <zoology> A voracious pikelike, marine fish, of the genus Sphyraena, sometimes used as food. That of Europe and our Atlantic coast is Sphyraena spet (or S. Vulgaris); a southern species is S. Picuda; the Californian is S. Argentea. 2. <zoology> A large edible fresh water fish of Australia and New Zealand (Thyrsites atun). Source: Websters Dictionary (01 Mar 1998) |
| Barraquer Roviralta, Luis | <person> Spanish physician, 1855-1928. See: Barraquer's disease. (05 Mar 2000) |
| Barraquer's disease | A condition characterised by a complete loss of the subcutaneous fat of the upper part of the torso, the arms, neck, and face, sometimes with an increase of fat in the tissues about and below the pelvis. Synonym: Barraquer's disease, lipodystrophia progessiva superior, partial lipoatrophy, Simons' disease. (05 Mar 2000) |
| Barraquer's method | Zonulysis Dissolution of the zonula ciliaris by enzymes (alpha-chymotrypsin) to facilitate surgical removal of a cataract. Synonym: Barraquer's method. Origin: zonule + G. Lysis, dissolution (05 Mar 2000) |
| Barraquer, Hignacio | <person> Spanish ophthalmologist, 1884-1965. See: Barraquer's method. (05 Mar 2000) |
| Barre's sign | <clinical sign> if the hemiplegic is placed in the prone position with the limbs flexed at the knees, he is unable to maintain the flexed position on the side of the lesion but extends the leg. (05 Mar 2000) |
| Barre, Jean | <person> French neurologist, *1880. See: Barre's sign, Guillain-Barre reflex, Guillain-Barre syndrome, Landry-Guillain-Barre syndrome. (05 Mar 2000) |
| barred owl | <zoology> A large American owl (Syrnium nebulosum); so called from the transverse bars of a dark brown colour on the breast. Source: Websters Dictionary (01 Mar 1998) |
| barrel | 1. A round vessel or cask, of greater length than breadth, and bulging in the middle, made of staves bound with hoops, and having flat ends or heads. 2. The quantity which constitutes a full barrel. This varies for different articles and also in different places for the same article, being regulated by custom or by law. A barrel of wine is 31 1/2 gallons; a barrel of flour is 196 pounds. 3. A solid drum, or a hollow cylinder or case; as, the barrel of a windlass; the barrel of a watch, within which the spring is coiled. 4. A metallic tube, as of a gun, from which a projectile is discharged. 5. A jar. 6. <zoology> The hollow basal part of a feather. <anatomy> Barrel bulk, the tympanum, or tympanic cavity. Barrel organ, an instrument for producing music by the action of a revolving cylinder. Barrel vault. See Vault. Origin: OE. Barel, F. Baril, prob. Fr. Barre bar. Cf. Barricade. Source: Websters Dictionary (01 Mar 1998) |
| barrel chest | A chest permanently resembling the shape of a barrel, i.e., with increased anteroposterior diameter, roughly equaling the lateral diameter; usually with some degree of kyphosis; seen in cases of emphysema. (05 Mar 2000) |
| barrel distortion | <microscopy> A distortion, or aberration. (05 Aug 1998) |
| Epstein-Barr virus | <virology> Species of Herpetoviridae that is responsible for infectious mononucleosis (glandular fever). Discovered in 1964, this virus has been associated with Burkitt's lymphoma in South African children and with nasopharyngeal carcinoma in Asian populations. (27 Sep 1997) |
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| epstein-barr virus nuclear antigens | Nuclear antigens encoded by epstein-barr virus genes. at least six nuclear antigens have been identified but their mechanism of action and role in B-cell transformation is still unknown. (12 Dec 1998) |