Medical Dictionary

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betula (bet′u-la)
European white birch, bark and leaves of B. alba (family Betulaceae); native to Europe, northern Asia, and North America, north of Pennsylvania. It contains betulin (b. camphor), betuloresinic acid, volatile oil, saponins, betulol (sesquiterpine alcohol), apigenin, dimethyl ether, betuloside, gaultherin, methyl salicylate, and ascorbic acid; has odor of wintergreen and is used as a pharmaceutic aid (flavor/aromatic).

Betz
Vladimir A., Russian anatomist, 1834–1894. See B. cells, under cell.

Beuren
Alois J., 20th century German cardiologist. See B. syndrome.

Bevan-Lewis
William, English physician and physiologist, 1847–1929. See Bevan-Lewis cells, under cell.

bevel (bev′el)
1. A surface having a sloped or slanting edge. 2. The incline that one surface or line makes with another when not at right angles. 3. The edge of a cutting instrument. 4. To create a slanting edge on a body structure. cavosurface b. the incline of the cavosurface angle of a prepared cavity wall in relation to the plane of the enamel wall. reverse b. the sloping edge of a cutting instrument.

bevonium methyl sulfate (be-vo′ne-um)
An anticholinergic agent. SYN: pyribenzyl methyl sulfate.

bezoar (be′zor)
A concretion formed in the alimentary canal of animals, and occasionally humans; formerly considered to be a useful medicine with magical properties and apparently still used for this purpose in some countries; according to the substance forming the ball, may be termed trichobezoar (hairball), trichophytobezoar (hair and vegetable fiber mixed), or phytobezoar (foodball). [Pers. padzahr, antidote]

Bezold
Friedrich, German otologist, 1842–1908. See B. abscess.

Bezold
Albert von, German physiologist, 1836–1868. See B. ganglion, B.-Jarisch reflex.

BGP
Abbreviation for bone Gla protein.

BHA
Abbreviation for butylated hydroxyanisole.

bhang (bang)
Name given in the East to powdered preparation of Cannabis sativa that is chewed or smoked by the local residents. SEE ALSO: cannabis. [Hind.]

BHN
Abbreviation for Brinell hardness number.

BHT
Abbreviation for butylated hydroxytoluene.

Bi
Symbol for bismuth.

bi-
1. Prefix meaning twice or double, referring to double structures or dual actions. 2. In chemistry, used to denote a partially neutralized acid (an acid salt); e.g., bisulfate. Cf.:bis-, di-. [L.]

Bial
Manfred, German physician, 1869–1908. See B. test.

Bianchi
Giovanni B., Italian anatomist, 1681–1761. See B. nodule.

biarticular (bi′ar-tik′u-lar)
SYN: diarthric.

bias (bi′-as)
1. Systematic discrepancy between a measurement and the true value; may be constant or proportionate and may adversely affect test results. 2. Any trend in the collection, analysis, interpretation, publication, or review of data that can lead to conclusions that differ systematically from the truth; deviation of results or inferences from the truth, or processes leading to deviation. [Fr. biais, obliquity, perh. fr. L. bifax, two-faced] There is no imputation of prejudice, partisanship, or other subjective or emotional factor such as an investigator's desire to achieve a particular outcome. More than 100 varieties of b. have been described but all fall into one of a rather small number of distinct categories: 1. Systematic one-sided variation of measurements from the true value (syn systematic error, instrumental error, or b.). 2. Variation of statistical summary measures (means, rates, measures of association, etc.) from their true values as a result of systematic variation of measurements, other flaws in data collection, or flaws in study design or analysis. 3. Deviation of inferences from the truth as a result of flaws in study design, data collection, or the analysis or interpretation of results. 4. A tendency of procedures in study design, data collection, analysis, interpretation, review or publication, to yield results or conclusions that depart from the truth. 5. Prejudice leading to the conscious or subconscious selection of study procedures that depart from the truth in a particular direction, or to one-sidedness in interpretation of results. This form of b. can arise as a result of shoddy scientific methods, or deliberately when investigators behave fraudulently in order to misrepresent the truth. ascertainment b. systematic failure to represent equally all classes of cases or persons supposed to be represented in a sample. cross-level b. a b. due to aggregation at the population level of causes and/or effects that are unlike at the individual level; can occur in ecologic studies. recall b. systematic error due to differences in accuracy or completeness of recall to memory of past events or experiences. reporting b. selective revealing or suppression of information about past medical history, e.g., details of exposure to sexually transmitted diseases. response b. systematic error due to differences in characteristics between those who choose or volunteer to take part in a study, and those who do not. sampling b. systematic error due to study of a nonrandom sample of a population.

biasterionic (bi-as-ter-e-on′ik)
Relating to both asterions, especially the b. diameter, or b. width, the shortest distance from one asterion to the other.

biauricular (bi-aw-rik′u-lar)
Relating to both auricles, in any sense.

bib.
Abbreviation for L. b., drink.

bibliomania (bib′le-o-ma′ne-a)
Morbidly intense desire to collect and possess books, especially rare books. [G. biblion, book, + mania, frenzy]

bibulous (bib′u-lus)
SYN: absorbent (1) . [L. bibulus, drinking freely, absorbent]

bicameral (bi-kam′er-al)
Having two chambers; denoting especially an abscess divided by a more or less complete septum. [bi- + L. camera, chamber]

bicapsular (bi-kap′soo-lar)
Having a double capsule.

bicarbonate (bi-kar′bon-at)
HCO3−;the ion remaining after the first dissociation of carbonic acid; a central buffering agent in blood. standard b. the plasma b. concentration of a sample of whole blood that has been equilibrated at 37°C with a carbon dioxide pressure of 40 mm Hg and an oxygen pressure greater than 100 mm Hg; abnormally high or low values indicate metabolic alkalosis or acidosis, respectively.

bicardiogram (bi-kar′de-o-gram)
The composite curve of an electrocardiogram representing the combined effects of the right and left ventricles.

bicellular (bi-sel′u-lar)
Having two cells or subdivisions.

bicephalus (bi-sef′a-lus)
SYN: dicephalus.

biceps (bi′seps)
A muscle with two origins or heads. Commonly used to refer to the b. brachii (muscle). [bi- + L. caput, head]

Bichat
Marie F.X., French anatomist, physician, and biologist, 1771–1802. See B. canal, B. fat-pad, B. fissure, B. fossa, B. ligament, B. membrane, B. protuberance, B. tunic.

bicho (be′cho)
SYN: epidemic gangrenous proctitis.

biciliate (bi-sil′e-at)
Having two cilia.

bicipital (bi-sip′i-tal)
1. Two-headed. 2. Relating to a biceps muscle. [bi- + L. caput, head]

Bickel
Gustav, 19th century German physician. See B. ring.

biclonal (bi-klo′nal)
Pertaining to or characterized by biclonality.

biclonality (bi-klon-al′i-te)
A condition in which some cells have markers of one cell line and other cells have markers of another cell line, as in biclonal leukemias.

biconcave (bi-kon′kav)
Concave on two sides; denoting especially a form of lens. SYN: concavoconcave.

biconvex (bi-kon′veks)
Convex on two sides; denoting especially a form of lens. SYN: convexoconvex.

bicornous, bicornuate, bicornate (bi-kor′nus, -noo-at, -nat)
Two-horned; having two processes or projections. [bi- + L. cornu, horn]

bicro-
SYN: pico- (2) .

bicron (bi′kron)
SYN: picometer.

bicuculline (bi′coo-cu-len)
An alkaloid naturally occurring in the d-form; found in Dicentra cucullaria and Adlumia fungosa (family Fumariaceae) and several Corydalis species; a powerful convulsant that acts by antagonizing γ-aminobutyric acid, an inhibitory neurotransmitter.

bicuspid (bi-kus′pid)
1. Having two points, prongs, or cusps. 2. Teeth having two cusps. Humans have eight b. or premolar teeth: two in front of each group of molars. See b. tooth. [bi- + L. cuspis, point] b. aortic valve See familial aortic ectasia syndrome.

bicuspidization (bi-kus′pi-di-za′shun)
Surgical change of a normally tricuspid valve into a functioning bicuspid valve; performed in correction of tricuspid valvar disease.

b.i.d.
Abbreviation for L. bis in die, twice a day.

bidactyly (bi-dak′ti-le)
Abnormality in which the medial digits are lacking, with only the first and fifth represented. SEE ALSO: lobster-claw deformity, ectrodactyly. [bi- + G. daktylos, finger]

bidet (be-da′)
A tub for a sitz bath, having also an attachment for giving vaginal or rectal infusions. [Fr. a small horse]

bidiscoidal (bi′dis-koy′dal)
Resembling, or consisting of, two disks.

BIDS [MIM*234050]
Acronym for brittle hair, impaired intelligence, decreased fertility, and short stature; the brittle hair may be due to an inherited deficiency of a high-sulfur protein; autosomal recessive inheritance.

biduous (bid′u-us)
Rarely used term denoting of two days' duration. [L. biduus, lasting two days, fr. bi- + dies, day]

Biebl
M. See B. loop.

Biebrich scarlet red [C.I. 26905]
SYN: scarlet red. [Biebrich, Germany]

Biederman
Joseph, U.S. physician, *1907. See B. sign.

Biedl
Artur, Austrian physician, 1869–1933. See Bardet-B. syndrome.

Bielschowsky
Max, German neuropathologist, 1869–1940. See B. disease, B. stain, Jansky-B. disease.

Bielschowsky
Alfred, German ophthalmologist, 1871–1940. See B. sign.

Biemond
Avic, French neurologist, *1902. See B. syndrome.

Bier
August K.G., German surgeon, 1861–1949. See B. amputation, B. hyperemia, B. method.

Biermer
Anton, German physician, 1827–1892. See B. anemia, B. disease, Addison-B. disease.

Biesiadecki
Alfred von, Polish physician, 1839–1888. See B. fossa.

bifascicular (bi′fa-sik′u-lar)
Involving two of the presumed three major fascicles of the ventricular conduction system of the heart.

bifid (bi′fid)
Split or cleft; separated into two parts. [L. bifidus, cleft in two parts]

Bifidobacterium (bi′fi-do-bak-ter′e-um)
A genus of anaerobic bacteria (family Actinomycetaceae) containing Gram-positive rods of highly variable appearance; freshly isolated strains characteristically show true and false branching, with bifurcated V and Y forms, uniform or branched, and club or spatulate forms. They frequently stain irregularly; two or more granules may stain with methylene blue, while the remainder of the cell is unstained. They are not acid fast, are nonmotile, and do not produce spores; acetic and lactic acids are produced from glucose. Pathogenicity for humans is rare, although they have been found in the feces and alimentary tract of infants, older people, and animals. The type species is B. bifidum. [L. bifidus, cleft in two parts, + bacterium] B. bifidum type species of the genus B.; it is found in the feces and alimentary tract of breast- and bottle-fed infants and of older persons, rats, turkeys, and chickens; also found in the rumen of cattle; pathogenicity for humans and other animals is rare. Associated with a growth factor belonging to a group of N-containing polysaccharides with a high hexosamine content and known as bifidus factor. B. dentium a bacterial species recovered in association with dental caries and periodontal disease. It is also an opportunistic pathogen, recovered in mixed infections associated with abscess formation.

bifocal (bi-fo′kal)
Having two foci.

biforate (bi-fo′rat)
Having two openings. [bi- + L. foro, pp. -atus, to bore, pierce]

bifunctional (bi-func′shun-al)
Referring to a molecule containing two reactive functional groups; cross-linking reagents are b. compounds.

bifurcate, bifurcated (bi-fer′kat, -ka-ted)
Forked; two-pronged; having two branches. [bi- + L. furca, fork]

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