GLYCERYL TRINITRATE
GOLFER'S ELBOW
Glycerol is used in moisturizing creams.
It is also used in eardrops to soften ear-
wax and in
cough remedies
to help
soothe a dry, irritating cough.
glyceryl trinitrate
A
vasodilator drug
used to treat and prevent symptoms of
angina pectoris.
High doses may cause a
headache, flushing, and dizziness.
glycogen
The main form of
carbohydrate
stored in the body, found mainly in the
liver and in muscles. When there is too
much glucose in the blood, the excess
is converted to glycogen by the action
of
insulin
and
corticosteroid hormones
.
When the blood glucose level is low, gly-
cogen is converted back to glucose (a
process regulated by
adrenaline
and
gluc-
agon
)
and released into the bloodstream.
glycosuria
The presence of
glucose
in
the urine. Glycosuria results from failure
of the
kidneys
to reabsorb glucose back
into the bloodstream after the blood
has been filtered. This may be due to
hyperglycaemia
, as in
diabetes mellitus
,
or may occur if the kidney tubules have
been damaged. However, glycosuria is
usually only significant if accompanied
by a high blood glucose level. Glyco-
suria often occurs during pregnancy
when the blood glucose level is normal.
Glycosuria is diagnosed by
urinalysis
.
Treatment depends on the cause.
glycosylated haemoglobin
A form of
haemoglobin
that is bound to the sugar
glucose. In most people, 3-8 per cent of
haemoglobin is glycosylated. In people
with
diabetes mellitus
, the level of glyco-
sylated haemoglobin may be raised if
treatment has not kept the blood glu-
cose level within the normal range.
Glycosylated haemoglobin levels indi-
cate blood glucose levels over the
preceding 3 months.
goitre
Enlargement of the
thyroid gland
,
visible as a swelling on the neck. The
thyroid gland may enlarge (without any
disturbance of its function) at
puberty
,
during pregnancy, or as a result of tak-
ing
oral contraceptives
.
In many parts of
the world the main cause of a goitre is
lack of
iodine
in the diet. A condition
called toxic goitre develops in
Graves'
disease
and in other forms of
hyperthy-
roidism
that lead to
thyrotoxicosis
.
A
goitre is also a feature of different types
of
th}nroiditis.
Other causes include a
tumour or nodule in the gland and, in
rare cases,
th^noid cancer.
A goitre can range in size from a barely
noticeable lump to a large swelling, de-
pending on the cause. Large swellings
may press on the
oesophagus
or
trachea,
making swallowing or breathing difficult.
G
A goitre not caused by disease may
eventually disappear. Goitre due to iodine
deficiency can be treated by dietary mea-
sures. When a goitre is the result of
disease, treatment is for the underlying
disorder. Large goitres can be treated
surgically (see
thyroidectomy
).
gold
An
antirheumatic drug
used to treat
severe
rheumatoid arthritis
and, occasion-
ally, arthritis arising as a complication
of
psoriasis
. It is given either as regular
injections or orally (see
auranofin
).
A
common adverse effect is
dermatitis
.
Gold may damage the kidneys, liver,
and bone marrow and may cause loss of
appetite, nausea, and diarrhoea.
golfer's elbow
A painful condition caused
by inflammation of the
epicondyle
(bony
prominence) on the inner
elbow
, at the
site of attachment of some forearm mus-
cles. Golfer's elbow is caused by overuse
of these muscles, which bend the wrist
and fingers. Activities such as using a
screwdriver or playing golf with a faulty
grip can cause the condition. Treatment
consists of resting the elbow, applying
ice-packs, and taking
analgesic drugs
to
relieve pain. If the pain is severe or per-
sistent, injection of a
corticosteroid drug
into the area may help.
255
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