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Glossary
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
acute phase
A short, sharp, and relatively
severe course of a disease; not chronic.
Addison's disease
A disease marked by
the atrophy or destruction of the adrenal cortex. Most cases of Addison's disease appear
to involve an autoimmune process.
alanine aminotransferase (a.
transaminase; ALT)
aminotransferases are enzymes that facilitate the conversion of
one amino acid into another, thus helping to maintain a balanced supply of amino acid
building blocks for protein synthesis. Elevated alanine amino transferase activity
provides a useful indicator for liver disorders.
albumin
A type of protein widely distributed
in the tissues and fluids of plants and animals. It is the single most abundant protein
in blood. Albumin acts as a carrier for numerous substances in the blood.
alkaline phosphatase
A group of
enzymes that belong to the class known as hydrolases. They are thought to play an
important role in the transport of sugars and phosphates in the intestine, bone, kidney
and placenta. Elevated serum levels of alkaline phosphatase activity may indicate liver
disease.
amino acid
A family of modified organic
acids that serve as building blocks for the synthesis of proteins.
amylase
An enzyme that breaks down complex
carbohydrates such as starch.
anaphylactic shock
An allergic
reaction marked by contraction of smooth muscle and dilation of blood vessels. If not
checked rapidly by an injection of epinephrine, the reaction can be lethal.
anorexia nervosa
A personality
disorder manifested by extreme aversion to food, usually occurring in young women.
anterograde
Moving forward.
antidepressants
Pharmaceutical agents
used to treat clinical depression.
anti-inflammatory
Agents that
reduce inflammation without directly antagonizing the agent that caused it.
antinuclear antibody
Anti-self
antibodies directed against the DNA. It is one indicator for the autoimmune disorder
systemic lupus erythematosis (SLE).
anxiety disorders
Also known as
anxiety neurosis or anxiety reaction. A condition that can be caused by both psychologic
and physiologic factors. It can take two general forms: (1) acute anxiety (panic
disorder), marked by repeated occurrences of intense self-limited anxiety lasting usually
a few minutes to an hour, or (2) chronic anxiety, characterized by less intense reactions
of much longer duration (days, weeks, or months).
asthma
A disease marked by recurrent attacks
of distressed breathing. It is most often due to allergic reactions to plant or animal
substances or to food products.
autoimmune disease
Disorders in
which the body mounts a destructive immune response against its own tissues.
axillary lymph nodes
Lymphoid
organs located near the shoulder joint.
B
bile duct
Tubular structures responsible for
conducting bile (a substance that aids in digestion) from the liver to the intestine.
biliary obstruction
Blockage or
clogging of a bile duct.
bilirubin
A red pigment formed from
hemoglobin during normal and abnormal destruction of red blood cells in the body.
bipolar affective disorder
A
mood disorder that commonly begins with depression and is characterized by at least one
period of elation sometime during the course of the illness.
Borrelia
A genus of bacteria with numerous
species that cause disease in humans. The diseases associated with these organisms are
typically relapsing fevers.
bulimia nervosa
A disorder marked by
morbidly increased appetite, often alternating with periods of anorexia.
C
Candida albicans
A common saprophyte
of the digestive tract and female urogenital tract. It does not ordinarily cause disease,
but may do so following a disruption of bacterial flora of the body, or in patients with
depressed immune systems.
case-control study
An epidemiologic
study that examines selected patients who have a defined disease (cases) with persons
without the disease (controls).
case definition
In the example of CFS,
a combination of symptoms, signs, and physiologic characteristics that serve to
distinguish a case of chronic fatigue syndrome from other disease states.
cervical lymph nodes
Lymphoid
organs located in the neck.
cholangitis
Inflammation of the bile
duct.
cholecystitis
Inflammation of the gall
bladder.
chronic
Of long duration, denoting a disease
of slow progress and long continuance.
chronic fatigue and immune dysfunction syndrome
(CFIDS)
A synonym for chronic fatigue syndrome used by some patients and
physicians. It should be stressed, however, that no immune dysfunction or aberration has
been persuasively linked to chronic fatigue syndrome.
cirrhosis
Progressive disease of the liver,
characterized by liver cell damage, scarring of the liver, and abnormal liver
architecture and function.
cluster investigation
An
epidemiologic investigation mounted to determine if there has been an unexpected increase
in the number or prevalence of cases of illness. The increase can be with respect to a
particular interval in time, a particular location, or both.
coenzyme
A substance that enhances or is
necessary for the action of enzymes. They are generally much smaller than enzymes
themselves.
co-morbid
Two or more disease conditions
that occur simultaneously within the same person. A diagnosis of CFS requires that
certain other conditions that may also cause fatigue, such as cancer, are not present.
connective tissue
The supporting
tissues of the body, such as tendons, ligaments, bone, and cartilage.
connective tissue disorder
A
variety of inflammatory diseases of connective tissue, the most common of which is
rheumatoid arthritis. Much, if not all, of this disease is now attributed to autoimmune
processes.
control
A device used to verify or regulate
a scientific experiment or study. A case-control study serves as a useful example. Since
patients with a specific illness are examined for various characteristics, a group of
healthy individuals who otherwise have as much in common with the patients as possible
must be examined in parallel for the same characteristics.
creatinine
A component of urine, and the
final breakdown product of creatine, which is an important molecule for building energy
reserves, for example, in muscle cells.
cross-sectional study
In
epidemiology, a study in which participants are examined at only a single time for
characteristics of a disease.
cytokine
Proteins manufactured by cells of
various lineages that, when secreted, drive specific responses (e.g., proliferation,
growth, or maturation) in other susceptible cells.
cytomegalovirus (CMV)
One of the eight
known types of human herpesviruses, also known as human herpesvirus 5 (HHV-5). It belongs
to the beta subfamily of herpesviruses. CMV can cause severe disease in patients with
immune deficiency and in newborns when the virus is transmitted in utero.
D
depression
A neurotic or psychotic
condition marked by an inability to concentrate, insomnia, and feelings of dejection and
guilt.
diabetes mellitus
A metabolic
disease in which carbohydrate utilization is reduced and fat and protein utilization is
enhanced. It is caused by insulin deficiency.
diabetic acidosis
A condition in
diabetic patients in which the levels of alkali are reduced relative to the level of
acids.
diabetic ketoacidosis
A form of
acidosis in diabetic patients caused by the enhanced production of ketone bodies.
diabetic nephrosclerosis
A
condition in diabetic patients marked by hardening of the kidney from overgrowth and
contraction of the connective tissue of the organ.
delusional disorders
A
psychiatric disorder characterized by states of heightened self-awareness and a tendency
toward paranoia.
dementias
A physically caused permanent or
progressive decline in intellectual function that interferes with the patient's normal
social or economic activity.
diuretics
Agents that promote the excretion
of and/or increase the amount of urine.
E
electrolytes
Substances that dissociate
in water to form a cation (positively charged ion) and and anion (negatively charged
ion). Charged ions are central to a variety of important processes in the body, including
muscle contraction and nerve impulse conduction.
enterovirus
A genus of RNA viruses with
over 70 types identified in humans. They reproduce in the intestinal tract, and various
members can cause a variety of human diseases, including poliomyelitis, aseptic
meningitis, hepatitis, inflammatory heart disease, and rhinitis.
enzyme
Specialized proteins that act as
catalysts for virtually all necessary chemical reactions that take place within the body.
Like all catalysts, enzymes unchanged by the reactions they promote, and will initiate
many reactions until they are degraded (usually by another enzyme).
eosinophil
A white cell of the category
known as granulocytes. These cells contain numerous dense granules in their cytoplasm
that comprise a battery of highly active digestive chemicals and toxins. Their chief role
is thought to be in combatting large parasites, although occasionally their activity may
be triggered by other agents, potentially leading to damage of normal tissues (see
eosinophilia myalgia syndrome).
eosinophilia myalgia syndrome
(EMS)
A disease caused by marked promotion of eosinophil activity,
resulting in a symptom complex of severe pain, inflammation of the tendons, fluid
build-up in the muscles, and skin rash. The disorder has been linked to a contaminant of
some commercial preparations of the amino acid L-tryptophan.
epidemiology
The branch of medical
science that deals with the incidence, distribution, and control of disease in a
population.
Epstein-Barr virus (EBV)
One of the
eight known types of human herpesviruses, also known as human herpesvirus 4 (HHV-4). It
belongs to the gamma subfamily of herpesviruses. It commonly causes acute mononucleosis,
and less commonly chronic mononucleosis. It some populations EBV is causally associated
with life-threatening malignancies (Burkitt's lymphoma, nasopharyngial carcinoma).
etiology
Causal association of a disease with
an agent. The study of the cause of diseases.
F
fibromyalgia
Also known as myofascial
pain syndrome and fibromyositis. A group of common rheumatoid disorders (not involving
the joints) characterized by achy pain, tenderness, and stiffness of muscles.
G
gamma (g) glutamyl
transferase
One of a family of enzymes involved in transporting amino
acids from the exterior to the cytoplasm of a cell. High serum levels of this enzyme
serve as an indicator for liver disease.
globulin
A family of proteins found in
abundance in plasma. They include the gamma globulins, which in turn include the various
antibody molecules produced by the immune system.
glomerulonephritis
Kidney disease
characterized by bilateral inflammatory changes in the glomeruli (tufts of capillary
loops associated with the nephrons, the functional units of the kidney). The disorder is
not caused by infection. It is considered an autoimmune disease.
glucose
A simple sugar which is actively
transferred into the blood following the digestive breakdown of starch and other
carbohydrates in the gut.
H
hematologic
Having to do with the blood.
hemoglobin
The red, oxygen-carrying protein
found in red blood cells.
hepatitis B virus
A small DNA virus
capable of causing both acute and chronic liver disease, possibly by eliciting tissue
damage by the immune system. The virus may also be a risk factor for hepatic carcinoma.
It is often transmitted through sexual activity or through exposure to contaminated
blood.
hepatitis C virus
An RNA virus
related to the pestiviruses and flaviviruses. It is capable of causing both acute and
chronic liver disease. As with hepatitis B, the liver damage resulting from this
infection may be the result of immune reactivity against virus-infected liver cells.
herpesvirus
A family of large DNA viruses
that infect a wide range of animal species. Eight distinct types have been associated
with a variety of human diseases.
human herpesvirus 6
A virus of the
herpesvirus beta-subfamily, discovered in 1985, that infects more than 95% of people by
the age of 2 years. It has been causally associated with roseola, mononucleosis-like
illness, inflammation of lymph glands. There is also suggestive evidence for a role in
multiple sclerosis.
hyperthyroidism
A condition marked by
excessive secretory activity of the thyroid gland.
hypoparathyroidism
A condition
caused by the rEducation or absence of secretions of the parathyroid gland.
hypothyroidism
Diminished production
of thyroid hormone, leading to thyroid insufficiency.
I
iatrogenic
Related to an abnormal state or
condition produced in a patient through inadvertant or erroneous treatment.
idiopathic
Denoting a disease of unknown
cause.
imaging tests
Any of a variety of methods
for observing the internal anatomy of the body, ranging from simple x-rays to complex
three-dimensional scanning techniques using nuclear magnetic resonance, positron
emission, and other techniques.
immune globulin
A crude preparation of
antibody molecules collected from pooled multiple blood donations, used as a means for
passively transferring antimicrobial resistance to susceptible individuals.
immune suppressants
Agents that
block or restrict the activity of one or more components of the immune system, usually
leading to increased susceptibility to infectious disease.
insomnia
Inability to sleep even in the
absence of external impediments, during the period when sleep should normally occur.
J
K
L
lactate
An ester of lactic acid produced
during non-respiratory glucose combustion. It may accumulate during some disease
conditions, leading to lactate acidosis.
lactate dehydrogenase
An enzyme
important to the process of glucose combustion in the body, and an important mechanism
for cellular energy production.
Lyme disease
A tick-transmitted
inflammatory disorder that begins with a characteristic skin rash, and may be followed
weeks to months later by neurologic, cardiac, or joint abnormalities.
lymphotrophic
Denoting a virus that
tends to bind to and infects one or more subsets of lymphocytes.
lymph node
Secondary immune organs
distributed at discrete locations throughout the body. These organs play a central role
in the activation and trafficking of immune lymphocytes in the body.
lymphocyte
Small white blood cells that are
uniform in appearance, but very diverse in function. Collectively, they are responsible
for antibody production, direct cell-mediated killing of virus-infected cells and tumor
cells, and for the regulation of virtually every other component of the mammalian immune
system.
M
magnetic resonance
imaging
The use of nuclear magnetic resonance of protons to produce
cross-sectional proton density images of internal structures of the human body.
malabsorption syndrome
Syndromes
resulting from impaired absorption of nutrients from the bowel.
malaise
A feeling of general discomfort or
uneasiness, an out-of-sorts feeling, often the first indication of an infection or other
disease.
multiple chemical sensitivity
disorder
A controversial diagnosis of an allergy-like sensitivity to an
unusually broad range and number of substances. This condition has not been subjected to
rigorous scientific scrutiny, and there is considerable doubt as to whether or not it
actually exists.
multiple sclerosis
A slowly
progressive central nervous system disease characterized by disseminated patches of
demyelination in the brain and spinal cord.
myalgic encephalomyelitis
A
synonym for chronic fatigue syndrome in common usage in the United Kingdom and Canada.
myoglobin
The oxygen-transporting protein
of muscle, resembling blood hemoglobin in function.
N
narcolepsy
A sudden, uncontrollable
disposition to sleep occurring at irregular intervals, with or without obvious
predisposing or exciting cause.
natural killer cell (NK)
A
lymphocyte which, unlike other lymphocytes, does not require specific activation by
foreign antigen. They are considered to play a "front line" role in controlling
infection, curbing infection until a specific, coordinated immune response can be
mounted.
neurasthenia
Nervous exhaustion. A
functional neurosis marked by intense nervous irritability and weakness.
neuromyasthenia
Muscular weakness,
usually of emotional origin.
neuropsychiatric
Relating to organic
and functional diseases of the nervous system.
neurotransmitters
Substances
produced in neurons that promote or inhibit the conduction of nerve impulses, such as
epinephrine, norepinephrine, dopamine, serotonin, and gamma-aminobutyrate.
O
osmolality
Osmotic concentration. An
indicator of fluid balance in the bodies tissues.
P
pathognomonic
Characteristic or
indicative of a disease, denoting especially one or more typical symptoms.
pathophysiologic
Characteristic
derangement of function seen in disease.
period prevalence
The number of
existing cases of an illness during a period or interval, divided by the average
population.
pituitary
Also known as the hypophysis, a
gland at the base of the brain with two functionally distinct lobes involved in
regulating growth, metabolism, and maturation.
plasma
The fluid portion of the blood, rich in
soluble proteins with a wide range of functions.
positron emission tomography (PET
scan)
Imaging technique that relies on the detection of gamma rays
emitted from tissues after administration of a natural biochemical substance into which
positron-emitting isotopes have been incorporated.
pulmonary
Relating to the lungs.
Q
R
radionuclide scans
Any of a variety
of medical imaging methods that rely on atomic isotopes that decay and emit radiation.
renal
Relating to the kidneys.
retrovirus
A family of RNA viruses that
have the unique characteristic of producing an enzyme that makes a DNA copy of its
genetic information from an RNA template (the opposite of what normally takes place). The
most widely recognized of these viruses is HIV, the causative agent in AIDS. Another
virus from this family (HTLV-1) has been associated with T cell leukemia. Initial reports
of an association of an HTLV-II-like retrovirus with CFS could not be confirmed in
subsequent studies.
roseola
Also known as roseola infantum,
exanthem subitem, and pseudorubella. An acute disease of infants or very young children
caused by HHV-6 and characterized by high fever and a skin rash.
rubella
Also known as German measles, an acute
disease marked by skin rash and swollen lymph nodes, but generally without fever. It is
caused by an RNA virus of the togavirus family.
S
sarcoidosis
A systemic disease involving
the lungs, lymph nodes, skin, liver, spleen, eyes, phalangial bones, and parotid glands,
characterized by granular nodules. Its cause is not known.
schizophrenia
The most common type of
psychosis, characterized by extensive withdrawal of the individual's interest from other
people and the outside world and the investment of it in his/her own self.
sentinel surveillance
A
monitoring method that employs a surrogate indicator for a public health problem,
allowing estimation of the magnitude of the problem in the general population.
sequelae
Morbid conditions following as a
consequence of a disease.
single photon emission computed tomography (SPECT)
scan
An imaging technique that measures the emission of photons of a
given energy from radioactive tracers introduced into the body. As with other forms of
computer-assisted tomography, the technique produces a series of cross-sectional images
of internal anatomy.
sinusitus
Inflammation of the lining
membrane of any sinus, especially of one of the paranasal sinuses.
sleep apnea
A group of potentially lethal
disorders in which breathing recurrently stops during sleep for long enough to cause
measurable blood deoxygenation.
subacute
A zone between acute and chronic,
denoting the course of a disease.
syphillis
An acute and chronic disease
caused by the bacteria Treponema pallidum, transmitted by direct contact, usually
through sexual intercourse.
systemic lupus
erythematosus
An inflammatory disease of connective tissue occurring
predominantly in women (90%). It is considered to be an autoimmune disease.
T
T lymphocyte, T cell
The most common
type of lymphocyte, itself divided into at least three subpopulations on the basis of
function — cytotoxic, or killer T lymphocytes, helper T lymphocytes, and suppressor
T lymphocytes. T cells play a cardinal role in regulating the immune system.
thyroid
A two-lobed structure located in
front of and on either side of the trachea, producing the hormone thryoxin; of or
relating to the thyroid gland.
thyroid-stimulating
hormone
A hormone of the anterior pituitary gland that stimulates and
regulates the development and secretory activity of the thyroid gland.
thyrotoxicosis
Poisoning from
hyperthyroidism.
titer
The concentration of a substance in a
solution, or the strength of such a substance detected by titration. In the current
context, the term is most likely to refer to antibody titer, which is a measure of the
concentration of specific antibodies to selected microbes that are circulating in an
individual's bloodstream.
tumor
An abnormal mass of tissue that grows
more rapidly than normal, and continues to grow after the stimuli which initiated the
new growth cease.
U
urea
The chief product of nitrogen metabolism
in mammals, excreted in the urine. Carbonyl diamide.
V
vitamin
A group of organic micronutrients,
present in minute quantities in natural foodstuffs, that are essential to normal
metabolism.
vitamin D deficiency
(ricketts
and osteomalacia) In children, the condition prevents normal bone development; in
adults, a lack of vitamin D causes demineralization of bone, particularly in the spine,
pelvis, and lower extremities.
vitamin D intoxication
A
disorder marked by weight loss, nausea, vomiting, and impaired renal function.
W
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