Webster's New World Medical Dictionary

Barrett esophagus
A complication of chronic
severe gastrointestinal reflux disease (GERD) that
involves a change in the type of cells that line the
inner wall of the lower esophagus. There is a small
but definite increased risk of cancer of the esopha-
gus (adenocarcinoma) in people with Barrett
esophagus. The diagnosis of Barrett esophagus is
made on seeing (through endoscopy) a pink
esophageal lining (mucosa) that extends a short
distance (usually less than 2.5 inches) up the
esophagus from the gastroesophageal junction and
finding cell changes on biopsy of the lining.
Treatment involves acid-suppression drugs and fol-
lowup monitoring of the esophagus is advised.
barrier method
A birth control method that
employs a barrier which prevents sperm from
entering the cervix, thereby preventing conception.
Condoms and diaphragms are examples of a barrier
method. See also 
cervical cap; condom; condom,
female; diaphragm.
Bartholin gland
One of a pair of glands between
the vulva and the vagina that produce lubrication in
response to stimulation. Along with a second pair of
nearby glands, called the lesser vestibular glands,
the Bartholin glands act to aid in sexual intercourse.
Also known as greater vestibular gland.
Bartonella henselae
See 
cat scratch disease.
Bartonella quintana
A parasitic microorganism
in the rickettsiae family that can multiply within the
gut of a louse and can then be transmitted to
humans and cause trench fever. Transmission
occurs when infected louse feces are rubbed into
abraded skin or into the whites of the eyes. Trench
fever was first recognized in the trenches of World
War I, and it now occurs among homeless people,
injection drug users, street alcoholics, and others
who live in cramped, unhygienic quarters. B. quin-
tana is also responsible for a disease called bacillary
angiomatosis in people infected with HIV, and for
infection of the heart and great vessels (endocardi-
tis) in people with bloodstream infection (bac-
teremia). Also known as Rochalimaea quintana. See
also 
trench fever.