other people (see isolation). In reverse
barrier nursing, a patient with reduced
ability to fight infections is protected
against outside infection. (See also
aseptic technique.)
bartholinitisAn infection of Bartholin’s
glands,at the entrance to the vagina,
that may be due to a sexually transmit-
ted infectionsuch as gonorrhoea. It
causes an intensely painful red swelling
at the opening of the ducts. Treatment
is with antibiotic drugs,analgesic drugs,
and warm baths. Bartholinitis some-
times leads to an abscessor a painless
cyst (called a Bartholin’s cyst), which
may become infected. Abscesses are
drained under general anaesthesia.
Recurrent abscesses or infected cysts
may need surgery to convert the duct
into an open pouch (see marsupializa-
tion) or to remove the gland completely
Bartholin’s glandsA pair of oval, pea-
sized glands whose ducts open into the
vulva (the folds of flesh that surround
the opening of the vagina). During sexu-
al arousal, these glands secrete a fluid
to lubricate the vulval region. Infection
of the glands causes bartholinitis.
basal cell carcinomaA type of skin
cancer, also known as a rodent ulcer or
BCC, that occurs most commonly on
the face or neck. It starts as a small, flat
nodule and grows slowly, eventually
forming a shallow ulcer with raised
pearly edges. Basal cell carcinoma is
caused by skin damage from the ultra-
violet radiation in sunlight. Fair-skinned
people over 50 are the most commonly
affected; dark and black-skinned people
are protected by the larger amount of
the skin pigment melanin. The risk is
reduced by avoiding overexposure to
strong sunlight, using sunscreens, and
wearing protective clothing and sun
hats. Without treatment, the carcinoma
gradually invades and destroys surround-
ing tissues but virtually never spreads
to other parts of the body. Treatment is
usually with surgery (or in some cases
radiotherapy) and is often completely
successful. Plastic surgery may also be
needed, however, depending on the size
and site of the tumour. People who
have had a basal cell carcinoma may
develop new tumours and should be
alert to any changes in their skin. (See
also melanoma,malignant; squamous cell
carcinoma; sunlight,adverse effects of.)
basal gangliaPaired nerve cell clusters
deep within the cerebrum (the main
mass of the brain) and upper part of
the brainstem. The basal ganglia play a
vital part in producing smooth, contin-
uous muscular actions and in stopping
and starting movement. Any disease or
degeneration affecting the basal ganglia
and their connections may lead to the
appearance of involuntary movements,
trembling, and weakness, as occur in
Parkinson’s disease.
basesee alkali.
basophilA type of white blood cell that
plays a part in inflammatory and aller-
gic reactions.
B-cellSee lymphocyte.
BCG vaccinationA vaccine that pro-
vides immunity against tuberculosis. BCG
is prepared from an artificially weak-
ened strain of bovine (cattle) tubercle
bacilli, themicroorganisms responsible
for the disease. BCG stands for “bacille
Calmette–Guérin”, after the 2 French-
men who developed the vaccine in 1906.
BCG is given to people at risk of tuber-
culosis and for whom a tuberculin testis
negative. These people include health
workers, contacts of people who have
tuberculosis, and immigrants (including
children) from countries with a high rate
of tuberculosis. Infants born to immi-
grants in this category are immunized,
without having a tuberculin test, within
a few days of birth. The vaccine is also
recommended for children aged 10–14
years for whom the test is negative.BARTHOLINITIS BCG VACCINATION
B
BASAL CELL CARCINOMA
Raised edge
of carcinomaShallow
ulcer