G6PD DEFICIENCY
GALLBLADDER CANCER
G6PD deficiency
An
X-linked disorder
that affects the chemistry of red blood
cells, making them prone to damage by
infectious illness or certain drugs or foods.
Red blood cells are missing G
6
PD (the
enzyme
glucose
6
phosphate dehydroge-
nase). The disorder most often affects
southern European and black men.
Women are unaffected but can carry the
abnormal gene.
Some
antimalarial drugs
and
antibiotics
can precipitate destruction of red cells
in affected people. In one form of G
6
PD
deficiency called
favism,
affected people
are sensitive to a chemical in broad
beans, which they must avoid eating.
After taking a precipitating drug or food,
or during an infectious illness, a person
with
G
6
PD
deficiency develops
the
symptoms (see
anaemia, haemolytic)
.
G
6
PD deficiency is diagnosed with a
blood test. There is no particular treat-
ment but symptoms caused by a drug
or food can be relieved by avoiding it.
GABA
The
abbreviation
for
gamma-
aminobutyric acid, a
neurotransmitter
.
GABA controls the flow of nerve impulses
by blocking the release of other neuro-
transmitters
(e.g.
noradrenaline
and
dopamine
)
that stimulate nerve activity.
GABA activity is increased by
benzodi-
azepine drugs
and
anticonvulsants
.
gabapentin
An
anticonvulsant drug
used
either alone or with other anticonvul-
sants to treat some types of
epilepsy
.
Common side effects include dizziness,
unsteadiness, and fatigue.
galactorrhoea
Spontaneous, persistent
production of milk by a woman who is
not pregnant or lactating (see
lactation
),
or, very rarely, by a man.
Lactation is initiated by a rise in the
level of
prolactin
, a hormone produced
by the
pituitary gland
. Galactorrhoea is
caused by excessive secretion of pro-
lactin due to a
pituitary tumour
or other
endocrine disease, such as
hypothy-
roidism
.
Some
antipsychotic drugs
may
also cause excessive secretion. Treat-
ment with
bromocriptine
suppresses
prolactin production, but the underlying
cause may also need treatment.
galactosaemia
A rare, inherited condi-
tion in which the body is unable to
convert the sugar galactose into
glucose
due to the absence of a liver enzyme.
It causes no symptoms at birth, but
jaundice
,
diarrhoea, and vomiting soon
develop and the baby fails to gain weight.
Untreated, the condition results in liver
disease, cataract, and
learning difficulties
.
The diagnosis is confirmed by urine and
blood tests. The major source of galac-
tose is the milk sugar lactose. Lactose-
free milk must be used throughout life.
gallbladder
A small, pear-shaped sac
situated under the liver that stores
bile
.
Bile, produced by the liver, passes into
the gallbladder via the hepatic and cystic
ducts. It is released into the intestine
via the common
bile duct
.
G
GALLBLADDER
Common
bile
duct___
LOCATION
Cystic duct
Gallbladder
lining
Wall of
/4
gallbladder
Fibrous
tissue
Hepatic
Liver
ducts
from
liver
Pancreas
g a llb la d d e r c a n c e r
A rare
cancer
of
unknown cause that occurs mainly in the
elderly. The cancer may cause
jaundice
and tenderness in the abdomen, but
it is sometimes symptomless. It is usu-
ally diagnosed by
ultrasound scanning.
243
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