DUODENAL ULCER
DYDROGESTERONE
Gastric surgery interferes with the nor-
mal mechanism for emptying food from
the stomach (see
digestion
).
If a meal
rich in carbohydrates is “dumped” too
quickly from the stomach, the upper
intestine may swell. This, together with
the excessive amounts of certain hor-
mones released into the bloodstream,
causes the symptoms of early dumping.
As sugars are absorbed from the intes-
tine, they rapidly increase the blood
glucose level, causing excess
insulin
release. This may in turn later lower the
blood glucose
level
below
normal,
causing the symptoms of late dumping.
A person who has had a gastrectomy
can avoid symptoms by eating frequent,
small dry meals that do not contain
refined carbohydrates. Symptoms may
also be prevented by lying down after a
large meal. Adding
guar gum
to food is
sometimes effective.
duodenal ulcer A raw area in the wall of
the
duodenum,
due to erosion of its inner
surface lining. Duodenal ulcers and gas-
tric ulcers (similar areas in the lining of
the stomach) are also called
peptic ulcers
.
duodenitis
Inflammation of the
duode-
num
(first part of the small intestine),
producing vague gastrointestinal symp-
toms. The condition is diagnosed by
oesophagogastroduodenoscopy (see
gas-
troscopy
) which is the examination of
the walls of the upper digestive tract
with a flexible viewing instrument. Treat-
ment is similar to that for a duodenal
ulcer (see
peptic u cer
).
duodenum
The first part of the small
intestine extending from the pylorus
(the muscular valve at the lower end of
the stomach) to the ligament of Treitz,
which marks the boundary between the
duodenum and the jejunum (the second
part of the small intestine). It is about
25 cm long and shaped like a C; it forms
a loop around the head of the
pancreas
.
Ducts from the pancreas,
liver
, and
gall-
bladder
feed into the duodenum through
a small opening. Digestive enzymes in
the pancreatic secretions and chemicals
in the bile are released into the duode-
num through this opening.
Dupuytren's contracture
A disorder
of the hand in which one or more fingers
become fixed in a bent position. In about
half the cases, both hands are affected.
In most cases there is no apparent cause,
but the disease may in part be inherited.
Men over 40 are most often affected.
The tissues under the skin in the fingers
or palm become thickened and short-
ened, causing difficulty in straightening
the fingers. Surgery can correct deformity
of the fingers, but in some cases there is
a recurrence of the condition.
DUPUYTREN'S CONTRACTURE
dura m ater The outer of the 3 mem-
branes (
meninges
) covering the brain.
dust diseases
Lung disorders caused by
dust particles inhaled and absorbed into
the lung tissues. There they may cause
fibrosis
(formation of scar tissue) and
progressive lung damage. The main
symptoms are a cough and breathing
difficulty. It may take at least 10 years of
exposure to dusts containing coal, sil-
ica, talc, or asbestos before serious lung
damage develops (see
pneumoconiosis
).
Hypersensitivity to moulds on hay or
grain may lead to allergic
alveolitis
. Pre-
ventive measures, such as the installation
of dust extraction machinery, have redu-
ced the incidence of dust diseases.
DVT
Deep vein thrombosis (see
throm-
bosis, deep vein
).
dwarfism
See
short stature.
dydrogesterone
A drug derived from
the female sex hormone
progesterone
.
It is used to treat
premenstrual syn-
drome
and menstrual problems (see
menstruation, disorders of
). It is also
given together with an
oestrogen drug
as
hormone replacement therapy
follow-
ing the menopause. Dydrogesterone is
sometimes prescribed for
endometriosis
or to prevent
miscarriage
. Adverse effects
include swollen ankles, weight gain,
breast tenderness, and nausea.
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