ALPHAj-ANTITRYPSIN DEFICIENCY
alpha1-antitrypsin deficiency
A rare
genetic disorder
in which a person is
missing the enzyme alpha^antitrypsin,
which protects the body from damage
by other enzymes. The disease mainly
affects tissues in the lungs, resulting in
emphysema,
and the liver, causing
cir-
rhosis.
The effects of alpha^antitrypsin
deficiency may not become apparent
until after the age of 30. There is no
cure, but symptoms can be relieved by
drug treatment. In severe cases, a
liver
transplant
may be a possibility.
alpha-blocker drugs
A group of drugs
used to treat
hypertension
(high blood
pressure) and urinary symptoms due to
enlargement
of the
prostate
gland
.
Alpha-blockers are also used to treat
urinary retention caused by an enlarged
prostate gland (see
prostate
,
enlarged
).
Side effects of the drugs may include
dizziness and fatigue due to a sudden
drop in blood pressure, nausea, dry
mouth, and drowsiness.
alpha-fetoprotein
A protein that is
produced in the liver and gastrointes-
tinal tract of the fetus and by some
abnormal tissues in adults.
Alpha-fetoprotein (AFP) can be meas-
ured in the maternal blood from the
latter part of the 1st trimester of preg-
nancy,
and
its
concentration
rises
between the
15th and 20th weeks.
Raised levels of AFP are associated with
fetal
neural tube defects
, such as
spina
bifida
or
anencephaly
, and certain kid-
ney abnormalities. High levels of AFP
also occur in multiple pregnancies (see
pregnancy
,
multiple
) and threatened or
actual
miscarriage
. AFP levels may be
unusually low if the fetus has
Down's
syndrome.
For this reason, measure-
ment of blood AFP is included in blood
tests, which are used to screen preg-
nant women for an increased risk of
Down's syndrome.
AFP levels are commonly raised in
adults with hepatoma (see
liver cancer
),
cancerous
teratoma
of the testes or
ovaries,
or cancer of the pancreas,
stomach, or lung. For this reason, AFP
is known as a tumour marker. AFP levels
can be used to monitor the results of
treatment of certain cancers; increasing
levels after surgery or chemotherapy
ALVEOLITIS
may indicate tumour recurrence. How-
ever, AFP levels are also raised in some
noncancerous conditions, including viral
and alcoholic
hepatitis
and
cirrhosis
.
alprazolam
A
benzodiazepine drug
used
in the treatment of
anxiety
,
panic attacks
,
and
phobias.
alprostadil
A
prostaglandin drug
used,
prior to surgery, to minimize the effects
of congenital heart defects in newborn
babies. Alprostadil is also used as a
treatment for impotence. It is adminis-
tered by self-injection into the penis or
as a gel introduced into the
urethra
to
produce an erection.
alternative medicine
Any medical sys-
tem based on a theory of disease or
method of treatment other than the
orthodox science of Western medicine.
(See also
complementary m edicine
.)
altitude sickness
See
mountain sickness
.
aluminium
A light, metallic element
found in bauxite and various other min-
erals. Aluminium compounds are used
in
antacid
medications and in
antiper-
spirants.
Most of the aluminium taken
into the body is excreted. Excessive
amounts are toxic and are stored in the
lungs, brain, liver, and thyroid gland,
where they may result in organ damage.
Certain industrial processes give off
fumes containing aluminium into the
air. These fumes can cause
fibrosis
of
lung tissue. Drugs that contain alumin-
ium may interfere with the absorption
of other drugs and, therefore, should
not be taken at the same time.
alveolectomy
See
alveoloplasty.
alveolitis
Inflammation and thickening
of the walls of the alveoli (tiny air sacs)
in the lungs. Alveolitis reduces the elas-
ticity, and therefore the efficiency, of the
lungs. It is most commonly due to an
allergic reaction to inhaled dust of ani-
mal or plant origin, as in
farmer's lung
,
bagassosis
, and pigeon fancier's lung
(due to particles from bird droppings).
Fibrosing alveolitis is an
autoimmune
disorder
. In some cases, it occurs with
other autoimmune disorders such as
rheumatoid arthritis
or systemic
lupus
erythematosus
. Radiation alveolitis is
caused by irradiation of the lungs and
may occur as a rare complication of
radiotherapy
for lung or breast cancer.
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