I
ALVEOLITIS
eyebrows. Skin diseases such as scalp
ringworm
(see
tinea),
lichen planus,
lupus erythematosus,
and
skin tumours
may also cause localized hair loss.
TREATMENT
Treatments for male-pattern baldness
include
hair transplants
or drug treat-
ments
with
minoxidil
or
finasteride.
Generalized
alopecia
often
resolves
without treatment. Treatment of local-
ized alopecia depends on the cause.
alpha1-antitrypsin deficiency
A rare
genetic disorder
in which a person
is missing the enzyme alphar antitryp-
sin,
which protects
the body from
damage by other enzymes. The disease
mainly affects tissues in the lungs,
resulting in
emphysema,
and the liver,
causing
cirrhosis.
The effects of alphar
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
COMMON DRUGS
• Alfuzosin •Doxazosin •Indoramin •Prazosin
• Tamsulosin •Terazosin
A group of drugs used to treat
hyperten-
sion
(high blood pressure) and urinary
symptoms resulting from an enlarged
prostate gland (see
prostate, enlarged).
Alpha-blocker drugs interfere with
the nerve signals that govern the con-
traction of blood vessels This causes the
vessels to widen (vasodilation), thereby
reducing the blood pressure. In the
treatment of an enlarged prostate gland,
alpha-blockers relax the ring of muscles
at the bladder outlet, which improves
the outflow of urine.
Side effects may include dizziness and
fatigue (caused by a drop in blood pres-
sure
on
standing
up),
drowsiness,
headache, nausea, and a dry mouth.
alpha-fetoprotein
A protein that is produced in the liver
and gastrointestinal tract of the fetus
and by some abnormal tissues in adults.
ALPHA-FETOPROTEIN IN
PREGNANCY
Alpha-fetoprotein (AFP) is excreted in
the fetal urine into the amniotic fluid;
the fluid is swallowed by the fetus,
which introduces AFP into the fetal
digestive system. Most of the AFP is
broken down in the fetal intestine, but
some of it passes into the mother’s cir-
culation. AFP can be measured in the
maternal blood from the latter part of
the first trimester of pregnancy, and its
concentration rises between the 15 th
and 20th weeks.
Raised levels of AFP are associated
with fetal
neural tube defects,
such as
spina bifida
or
anencephaly,
and certain
kidney 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, measurement of blood AFP is
included in blood tests that are used to
screen pregnant women for increased
risk of Down’s syndrome.
ALPHA-FETOPROTEIN IN
ADULTS
AFP
levels are
commonly raised in
adults with hepatoma (see
liver cancer),
cancerous
teratoma
of the testes
or
ovaries, or cancer of the pancreas, stom-
ach, or lung. For this reason, AFP is
known as a “tumour marker”.
AFP levels can be used to monitor
results of treatment of such cancers;
increasing levels after chemotherapy or
surgery may indicate recurrence. How-
ever, AFP levels are also raised in some
noncancerous conditions such as viral
and alcoholic
hepatitis
and
cirrhosis.
alprazolam
A
benzodiazepine drug
that is used in
the treatment of
anxiety, panic attacks,
and
phobias
.
alprostadil
A
prostaglandin drug
used to minimize
the effects of congenital (present from
birth) heart defects in newborn babies
prior to corrective surgery; it is usually
administered in hospital. Alprostadil is
also used as treatment for impotence. To
produce an erection, it is self-adminis-
tered, either by injection into the penis
or as a gel introduced into the
urethra.
alternative medicine
Also called
complementary medicine,
any
medical system based on a theory of
disease or method of treatment other
than orthodox Western medicine.
altitude sickness
See
mountain sickness
.
aluminium
A light, metallic element that is found
in bauxite and various other minerals.
Aluminium
compounds are used in
antacid drugs
and in
antiperspirants.
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. Inhalation of these fumes can cause
fibrosis
of lung tissue. Drugs that contain
aluminium interfere with the absorp-
tion and excretion of a number of other
drugs and should not, therefore, be
taken simultaneously.
alveolectomy
See
alveoloplasty
.
alveolitis
Inflammation and thickening of the
walls of the alveoli (the tiny air sacs in
the lungs). Alveolitis reduces the elastic-
ity of the lungs during breathing and
reduces the efficiency of the transfer of
gas between the lungs and the sur-
rounding blood vessels.
CAUSES
Alveolitis is commonly caused by an
allergic reaction to inhaled dust of ani-
mal or plant origin, as in
farmer’s lung
(caused by spores from mouldy hay),
bagassosis
(caused
by
spores
from
mouldy sugar-cane residue), and pigeon
fancier’s lung (caused by particles from
bird droppings). This type of alveolitis
is known as extrinsic allergic alveolitis.
Trachea
Bronchus
Bronchiole
Lung
Normal
alveoli
Inflamed
alveoli
Effects of alveolitis
The alveoli become inflamed and their walls
thicken, causing the lungsto become less elastic
and less able to transfer oxygen.
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