GTN
GUT
G
GTN
The abbreviation for
glyceryl tri-
nitrate
.
guar gum
A gum extracted from the
cluster bean (
CYAMOPSIS TETRAGONOLABA).
Guar gum is not digested in the body. It
is taken (as granules sprinkled on food
or dissolved in water) as an aid to con-
trolling the blood
glucose
level in people
with
diabetes mellitus
because it slows
absorption of glucose in the small in-
testine. Guar gum may cause
flatulence
,
nausea, and abdominal discomfort.
Guillain-Barre syndrome
A rare con-
dition affecting the peripheral nerves
(see
peripheral nervous system
)
that
causes weakness, usually in the limbs.
The cause is believed to be an allergic
reaction to an infection, usually viral;
the nerves are damaged by
antibodies
produced by the body to eliminate the
infection. In most cases, the disease
develops 2 or 3 weeks after the onset of
infection. Weakness, often accompanied
by numbness and tingling, usually starts
in the legs and spreads to the arms. The
weakness may become progressively
worse, resulting in
paralysis
.
The mus-
cles of the face and those controlling
speech, swallowing, and breathing may
also be affected.
Diagnosis of Guillain-Barre syndrome
is confirmed by electrical tests to mea-
sure how fast nerve impulses are being
conducted, or by a
lumbar puncture
.
Most people recover fully with only sup-
portive treatment. However, in severe
cases, treatment with
plasmapheresis
or
immunoglobulin
may be given. Mechan-
ical
ventilation
may be needed to aid
breathing if the respiratory muscles and
diaphragm
are severely affected. Some
people are left with permanent weak-
ness in affected areas and/or suffer from
further attacks of the disease.
guilt
A painful feeling that arises from
the awareness of having broken a moral
code. Guilt is self-inflicted, unlike shame,
which depends on how other people
view the transgression. Some psycho-
analysts view guilt as a result of the
prohibitions of the
superego
instilled by
parental authority in early life. Others
see guilt as a conditioned response to
actions that in the past have led to pun-
ishment. Feeling guilty for no reason or
for an imagined crime is one of the
main symptoms of psychotic
depression
.
Guinea worm disease
A tropical dis-
ease caused by a female parasitic worm
more than 1
m long. Infection is the
result of drinking water containing the
water flea cyclops, which harbours larvae
of the worm. The larvae pass through
the intestine and mature in body tissues.
After about a year, the adult female worm,
now pregnant, approaches the skin sur-
face and creates an inflamed blister that
bursts, exposing the end of the worm.
Urticaria
,
nausea, and diarrhoea often
develop while the blister is forming. The
disease occurs in Africa, South America,
the Caribbean, Middle East, and India.
The traditional remedy is to wind the
worm from the skin on to a small stick.
Once the worm is out, the condition
usually clears up. The drugs
tiabenda-
zole
and niridazole are given to reduce
inflammation,
antibiotics
are given to
control secondary infection, and the
patient is immunized against
tetanus
.
Gulf War syndrome
A group of symp-
toms caused by exposure of people in
the armed forces to chemicals, includ-
ing insecticides, used during the Gulf
War in 1991. Gulf War syndrome may
also be due to side effects of
vaccines
and drugs given to the armed forces to
prevent against possible attacks of
chemical and biological weapons.
gullet
Common name for the
oesophagus
.
gum
The soft tissue surrounding the
teeth
that protects underlying structures and
keeps the teeth in position in the jaw.
Healthy gums are pink or brown and
firm. Careful
oral hygiene
helps prevent
gum disease.
Gingivitis
may occur if
plaque
is allowed to collect around the
base of the teeth. Untreated gingivitis
may lead to chronic
periodontitis
. Bleed-
ing gums are nearly always a symptom
of gingivitis; rarely, they are due to
leukaemia
or
scurvy
.
Gingival
hyperplasia
occurs most often as a side-effect of
treatment with
phenytoin
.
gumboil
See
abscess, dental
.
gumma
A soft tumour that may develop
in the late stages of untreated
syphilis
.
These tumours are very uncommon in
developed countries.
gut
A common name for the
intestine
.
260
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