warts, skin tags, some birthmarks, some
skin cancers,and to treat haemorrhoids.
cryotherapyThe use of cold or freezing
in treatment. (See also cryosurgery.)
cryptococcosisA rare infection caused
by inhaling the fungus CRYPTOCOCCUS
NEOFORMANSfound especially in soil con-
taminatedwith pigeon droppings. The
most serious form the infection can take
is meningitis. Another form of infection
causes growths in the lungs, resulting
in chest pain and a cough, or on the
skin, causing a rash of ulcers. Most cases
of cryptococcosis occur in people with re-
duced immunity, such as those with AIDS.
Cryptococcal meningitis is diagnosed
from a sample of spinal fluid. A combi-
nation of amphotericin Band another
antifungal drug, flucytosine, is usually
prescribed. Most cases in which only the
lungs are infected need no treatment.
cryptorchidismA developmental dis-
order of male infants in which the
testes fail to descend normally into the
scrotum (see testis, undescended).
cryptosporidiosisA type of diarrhoeal
infection caused by protozoa, which may
be spread from person to person or from
domestic animals to people. The disease
causes watery diarrhoea and sometimes
fever and abdominal pain. It is most com-
mon in children but also occurs in male
homosexuals. Treatment, apart fromre-
hydration therapy,is not usually needed
except for people whose immune system
is suppressed, in whom the infection may
be much more severe.
CT scanningA diagnostic technique in
which the combined use of a computer
and X-rayspassed through the body at
different angles produces cross-sectional
images of tissues. CT (computed tomo-
graphy) scanning has revolutionized the
diagnosis and treatment of tumours, ab-
scesses, and haemorrhages in the brain,
as well as head injuriesand strokes. CT
scanning is also used to locate and image
tumours, investigate diseases, and aid
needle biopsyin organs of the trunk.
Newer types of CT scanners use a spi-
ral technique: the scanner rotates around
the body as the patient is moved slowly
forwards on a bed, causing the X-ray
beams to follow a spiral course. The
computer produces 3-D images. Injectedbadlydecayed or weakened, it may be
necessary to remove the entire natural
crown of the tooth and then fit the arti-
ficial crown onto a post cemented in
the root canal.
cruciate ligamentsTwo ligamentsin the
knee that pass over each other to form a
cross. The ligaments form connections
between the femurand tibiainside the
knee joint and prevent overbending and
overstraightening at the knee.
crush syndromeDamage to a large
amount of body muscle(usually as a
result of a serious accident) causing kid-
ney failure. The damaged muscles release
proteins into the bloodstream, temporar-
ily impairing kidney function. Dialysis is
given while the kidneys recover.
crutch palsyWeakness or paralysisof
muscles in the wrist, fingers, and thumb
due to pressure on the nervesthat sup-
ply these muscles from a crutch pressing
under the arm. The condition does not
occur in people who use the more com-
mon elbow crutches.
crying in infantsA normal response in
babies to needs or discomforts, such as
hunger or thirst. Most healthy babies stop
crying when their needs are attended to.
In a few cases, persistent crying may be
due to a physical cause such as intoler-
ance of cow’s milk or an illness (such as
an ear or throat infection, or a viral fever).
cryo-A prefix meaning ice cold, used
medically to indicate that a procedure
uses freezing or low temperatures.
cryopreservationThe preservation of
living cells by freezing. The technique is
used to store human eggs for in vitro
fertilization, sperm for artificial insem-
ination, or plasmaand blood belonging
to rare blood groups.
cryosurgeryThe use of temperatures
below freezing to destroy tissue, or the
use of cold during surgery to produce
adhesionbetween an instrument and
body tissue. Cryosurgery causes only
minimal scarring and is used to treat
cancerous tumours in sites where heavy
scarring can block vital openings such
as in the cervix, the liver, and the
intestines. It may be used in eye opera-
tions, for example in cataract surgery
and treatment forretinal detachment.It
is also commonly used for removing
CRUCIATE LIGAMENTS CT SCANNING
C