GALLBLADDER, DISORDERS OF
GANGRENE
G
Treatment is by surgical removal of the
tumour, but the cancer has often spread
to the liver by the time it is detected,
making the outlook poor.
gallbladder, disorders of
The princi-
pal
gallbladder
disorder is
gallstones
,
which are common and often symptom-
less. Attempts by the gallbladder to
expel the stones can cause
biliary colic
.
If a gallstone becomes stuck in the gall-
bladder outlet, acute
cholecystitis
may
develop. Occasionally, this leads to a
painful condition called
empyema
of the
gallbladder. If a gallbladder is empty
when a stone obstructs its outlet, it may
fill with mucus, resulting in a
mucocele
.
Gallbladder cancer
is rare.
gallium
A
metallic
element
whose
radioactive form is used in
radionuclide
scanning
to detect areas of inflamma-
tion such as those that occur in cancers,
abscesses
,
osteomyelitis
,
and
sarcoidosis
.
gallstones
Lumps of solid matter found
in the
gallbladder
,
or in the
bile ducts
.
Gallstones are composed mainly of
cholesterol
and bile pigments from the
breakdown of red blood cells. They
develop when there is a disturbance in
the chemical composition of
bile
.
Gallstones are rare in childhood and
become increasingly common with age.
Women are affected more than men.
Risk factors include a high-fat diet and
being overweight.
Most gallstones cause no symptoms.
When symptoms do occur, they often
begin when a stone gets stuck in the
duct leading from the gallbladder, caus-
ing
biliary colic
and nausea. Gallstones
may cause indigestion and
flatulence
.
Possible complications are
cholecystitis
and
bile duct obstruction
.
Diagnosis is by
ultrasound scanning
,
X-ray oral
cholecystography
, or
cholan-
giography
. Stones that are not causing
symptoms are usually left alone. In
other cases, the gallbladder and stones
may be removed by
cholecystectomy
.
Ultrasonic shock waves (see
lithotripsy
)
are sometimes used to shatter stones;
the fragments pass into the bowel and
cause no further problems. Drugs such
as
chenodeoxycholic acid
or
ursodeoxy-
cholic acid
can dissolve some stones if
given over a period of months.
gambling,
pathological
Chronic in-
ability to resist impulses to gamble,
resulting in personal or social problems.
gamete
A sex cell, which is either the
sperm
of the male or the
ovum
(egg
cell) of the female.
gamete
intrafallopian
transfer
(GIFT)
A technique for assisting
con-
ception
(see
infertility
), which can only
be used if a woman has normal
fallopian
tubes
. In GIFT, eggs are removed from
an
ovary
during
laparoscopy
and mixed
with sperm in the laboratory before
both are introduced into a fallopian
tube. A fertilized egg may then become
implanted in the
uterus
.
gamma-globulin
A
substance
pre-
pared from human blood that contains
antibodies
against most common infec-
tions. (See
immunoglobulin injections
.)
gamolenic acid
An essential
fatty acid
found in evening primrose oil and
starflower oil (borage oil). Gamolenic
acid may be prescribed for breast ten-
derness,
premenstrual syndrome
, and
eczema
. Very large doses may cause
abdominal pain and loose stools.
ganciclovir
An
antivkal drug
that is
used to treat serious
cytomegalovirus
infection in people with an impaired or
suppressed immune system as a result
of AIDS or following organ transplan-
tation.
Side effects include nausea,
diarrhoea, abdominal pain, weakness,
and bone marrow suppression.
ganglion
A group of
nerve
cells that have
a common function; for example, the
basal ganglia
in the brain are concerned
with the control of muscular movements.
The term is also used to describe a
fluid-filled swelling associated with the
sheath of a
tendon
.
gangrene
Death of tissue, usually as a
result of loss of blood supply. Gangrene
may affect a small area of skin or a sub-
stantial portion of a limb. Pain is felt in
the dying tissues, but once dead they
become numb. The affected tissue turns
black. There are two types of gangrene:
dry and wet. In dry gangrene, there is
usually no infection, and the tissue
dies because it has no blood supply.
Dry gangrene does not spread, and it
may be caused by
arteriosclerosis
,
dia-
betes mellitus
,
thrombosis
,
frostbite, or
244
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