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Bethlem myopathy

A rare, autosomal dominant form of limb-girdle muscular dystrophy that becomes clinically obvious in early childhood. It is usually slowly progressive, gradually resulting in weakness that may limit the ability to walk independently. Muscle contractures, e.g., of the hands, ankles, and elbows, are characteristic.


(bech″ŭ-lās′ē-ē″) [Betula + -aceae] A family of flowering, nut-bearing trees, the birch family, that also includes alders, hazels, and hornbeams. Pollen from members of this family produces allergic reactions in many people in the early spring. SEE: Fagales.

Betula verrucosa

(bech′ŭ-lă vĕ-roo-kō′să) [L. betula verrucosa, rough birch] The scientific name for the European white birch tree. The pollen from this birch, abbreviated Bet by the World Health Organization, contains allergens that cause allergies in the spring in the northern hemisphere. SEE: Betulaceae.

Betz cell

(bets) [Vladimir A. Betz, Russ. anatomist, 1834–1894] A type of giant pyramidal cell in the cortical motor area of the brain. The axons of these cells are included in the pyramidal tract.


(bev′ĕl) 1. A surface slanting from the horizontal or vertical. 2. In dentistry, to produce a slanting surface in the enamel margins of a cavity preparation, named according to the surface that results.


(bē′zor) [Arabic bazahr, protecting against poison] A hard mass of entangled material sometimes found in the stomachs and intestines of animals and humans, such as a hairball (trichobezoar), a hair and vegetable fiberball (trichophytobezoar), or a vegetable food-ball (phytobezoar).

Bezold, Friedrich

(bē′zold″, bāt′solt″) Ger. otologist, 1842–1908.

B.'s abscess An abscess that erodes through the mastoid bone into the superior portion of the sternocleidomastoid muscle of the neck. Such an abscess can travel through muscle or fascial planes into neighboring tissues in the neck, the mediastinum, or the throat and can be life-threatening.

B.'s mastoiditis Abscess underneath insertion of the sternocleidomastoid muscle caused by pus breaking through the mastoid tip.

B.'s perforation A perforation on the inner surface of the mastoid bone.


biologically false positive.






[L. bis, twice] Prefix meaning two, double, twice.


(bī″ar-tik′yă-lăr) [bi- + articular] Pert. to two joints (such as the temporomandibular joints); diarthric.


(bī′ăs) [Fr. biais, oblique] In experimental medicine, statistics, and epidemiology, any effect or interference tending to produce results that depart systematically from the true ...

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