CHOLESTATIC JAUNDICE
cholestatic jaundice
Jaundice
(yellow discoloration of the
skin) that occurs as a result of
cholesta-
sis
(obstruction in the flow of bile to
the intestine).
C
cholesteatoma
A rare but serious condition in w hich
skin cells proliferate and grow inwards
from the ear canal into the middle ear.
Cholesteatoma usually occurs as a result
of long-standing
otitis media
(a m iddle-
ear infection) together with a defect in
the eardrum (see
eardrum, perforated).
If
left untreated, it may grow and damage
the small bones in the middle ear and
surrounding structures.
Cholesteatoma needs to be removed
surgically through the eardrum or by
mastoidectomy
(removal of the mastoid
bone, w hich is located behind the ear,
together with the cholesteatoma).
cholesterol
A fat-like substance that is an important
constituent of body cells and also is
involved in the formation of
hormones
and bile salts. Cholesterol is made by
the liver from various foods, especially
those containing saturated fats (see
fats
and oils
) ,
although a small amount is
absorbed directly from cholesterol-rich
foods such as eggs and shellfish.
Both cholesterol and fats (triglycer-
ides) are transported in the blood as
lipoproteins. These are particles with a
core, w hich is made of varying propor-
tions of cholesterol and triglycerides,
and an outer layer made of proteins.
CHOLESTEROL-RELATED DISEASES
High blood cholesterol levels increase
the risk of
atherosclerosis
(accumulation
of fatty deposits on the lining of the
arteries) and w ith it the risk of
coronary
artery disease
or of
stroke
(damage to
part of the brain due to interruption of
its blood supply). In general, choles-
terol transported in the bloodstream as
low-density lipoproteins (LDLs) or as
very low-density lipoproteins (VLDLs)
is a risk factor for these conditions,
w hile cholesterol in the form of high-
density lipoproteins (HDLs) seems to
protect against arterial disease.
Levels of cholesterol in the blood are
influenced by diet, genetic factors, and
metabolic
diseases
such
as
diabetes
mellitus
.
Cholesterol levels can be mea-
sured by blood tests. They are measured
in m illim oles per litre (m m ol/L). The
optimun level is less than
5
.
0
. Higher
levels may require dietary modification.
Sometimes, however, medication (such
as
simvastatin
) may be required to re-
duce the risk of arterial diseases.
cholesterolosis
Abnormal
deposits
of
cholesterol
in
the lining of the gallbladder that may
be associated with the
development
of
gallstones
.
Cholesterolosis is some-
times known as strawberry gallbladder
because of the appearance of an affec-
ted gallbladder.
cholestyramine
An alternative spelling for the lipid-
lowering drug
colestyramine
.
cholic acid
One of the acids contained in
bile
.
cholinergic crisis
A condition that affects people with
myasthenia gravis
w ho are undergoing
treatment with
cholinesterase inhibitors
.
The problem is caused by an overdose
of cholinesterase inhibitors. During a
cholinergic crisis, the muscle weakness
that is associated with myasthenia gra-
vis worsens
dramatically,
and needs
emergency medical treatment.
cholinesterase inhibitors
COMMON DRUGS
• Neostigmine •Pyridostigmine
A group of drugs, also known as anti-
cholinesterases, that are used to relieve
muscle weakness resulting from myas-
thenia gravis. In this disease, abnormal
activity of the immune system causes
the destruction of receptors on muscle
cells that bind w ith acetylcholine, a
neurotransmitter that makes the mus-
cles contract. Cholinesterase inhibitors
block the action of acetylcholinester-
ase, the enzyme that normally breaks
down acetylcholine, allowing the neu-
rotransmitter more time to act. The
drugs are
also
used to
reverse
the
effects of muscle-relaxant drugs given
with general anaesthesia.
chondritis
Inflammation of
cartilage
(connective
tissue composed of the gel-like sub-
stance collagen). It is usually caused by
pressure, stress, or injury.
Costochondritis is inflammation of
the cartilage between the ribs and the
sternum
(breastbone). This condition
causes tenderness over the sternum and
pain if pressure is exerted on the ribs at
the front of the chest. Chondritis may
also affect the cartilage lining the hip
and knee joints; this inflammation may
eventually lead to
osteoarthritis
.
chondro-
A prefix denoting a relationship to
car-
tilage
,
as in chondrocyte, a cell that
produces cartilage.
chondrocalcinosis
The presence of calcium pyrophosphate
in joint cartilage. The condition, w hich
occurs in
pseudogout
(a form of arthri-
tis), causes pain and swelling.
chondroma
A noncancerous tumour composed of
cartilage
,
affecting the bones. Chondro-
mas most often occur in the hands and
feet (see
chondromatosis
) .
chondromalacia patellae
A painful knee disorder, one cause of
anterior knee pain, in w hich the
carti-
lage
(connective tissue composed of
the gel-like substance collagen) behind
the patella (kneecap) is damaged. Ado-
lescents are most commonly affected.
CAUSE
Chondromalacia
patellae
may
result
from knee injuries or sporting activities
in w hich the knee is bent for long per-
iods (such as horse-riding). This action
may weaken
the inner part of the
quadriceps muscle
(w hich is at the
front of the thigh), causing the patella
to tilt when the knee is straightened
and rubs against the lower end of the
femur
(thigh bone). The rubbing causes
the cartilage that covers both bones to
roughen, causing pain and tenderness.
TREATMENT
Treatment of chondromalacia patellae
is with
analgesic drugs
(painkillers) and
exercises to strengthen the thigh mus-
cles. Rarely, surgery is needed.
chondromatosis
A condition in w hich multiple non-
cancerous tumours, called
chondromas
,
arise in the bones, most commonly in
the bones of the hands and feet. The
tumour cells consist of
cartilage
(con-
nective tissue composed of the gel-like
substance
collagen).
Chondromatosis
usually causes no symptoms.
chondrosarcoma
A cancerous growth of
cartilage
(con-
nective tissue composed of the gel-like
substance collagen). Chondrosarcoma
170
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