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Our medical glossary includes definitions
for terms related to hepatitis and its treatment, and general
medicine, health, and sexuality. Click on a link below for
definitions of medical terms beginning with that letter.
ABDOMEN (adjective
ABDOMINAL): the area of the body between the chest and pelvis.
ABSORPTION: the passage of
nutrients, drugs, or water from the intestines into the bloodstream.
ABSTRACT: a written summary of the important points of a medical
article.
ACCELERATE: speed up.
ACCELERATED APPROVAL: FDA regulations governing early marketing
approval of promising drugs for life-threatening illnesses.
ACETAMINOPHEN: an analgesic drug used to relieve pain
and reduce fever. Tylenol is the most well known brand name.
ACQUIRED IMMUNE DEFICIENCY SYNDROME (AIDS): a syndrome characterized
by suppression of the immune system, rendering the body susceptible
to various illnesses; the late, symptomatic stage of HIV disease.
ACTIGALL: see ursodiol.
ACTIVE INFECTION: an infection in which a disease-causing
microorganism is actively replicating and infecting new cells.
ACUPRESSURE: a traditional Chinese healing technique in which
finger pressure is applied to specific points on the body
to treat disease and ameliorate symptoms.
ACUPUNCTURE: a traditional Chinese healing technique that
involves inserting thin needles into different acupuncture
points on the body. Acupuncture is believed to improve the
flow of qi, the body's vital energy; it is used for many conditions,
including pain and addiction.
ACUTE: rapid-onset, short-term initial stage of a disease.
Contrast with chronic.
ACUTE HEPATITIS: the initial stage of viral hepatitis following
infection. In HCV, acute hepatitis refers to the first six
months of infection.
ADA: see Americans with Disabilities Act.
ADHERENCE: following a prescribed treatment regimen, including
correct dosage, timing, and number of doses per day.
ADJUNCT THERAPY: therapy given in addition to a primary treatment.
ADRENAL GLAND: one of a pair of glands located above the kidneys.
The adrenal medulla produces hormones such as adrenaline (epinephrine),
while the adrenal cortex produces corticosteroids and androgens.
ADVERSE REACTION (SIDE EFFECT): an undesired action or effect
of a drug or other treatment.
AEROBIC EXERCISE: a type of exercise (e.g., running, swimming)
that makes the heart and lungs work harder to supply the muscles
with oxygen.
AFP: see alpha-fetoprotein.
AIDS: see acquired immune deficiency syndrome.
ALANINE AMINOTRANSFERASE (ALT; formerly SGPT): an enzyme (also
called alanine transaminase) produced in the liver when the
membranes of liver cells break down. ALT levels are measured
to help assess the degree of liver damage and determine how
well HCV treatment is working. A normal level is below 48
IU/L.
ALBUMIN: a blood protein produced by the liver that plays
a role in maintaining normal blood volume. A low albumin level
is associated with liver cirrhosis. A normal level is 3.2-5.0g.
ALCOHOLISM: a disorder characterized by excessive consumption
of and dependence on alcohol.
ALFERON: brand name of human leukocyte-derived interferon-alpha-n3,
produced by ISI Pharmaceuticals.
ALKALINE PHOSPHATASE (AP): an enzyme found in various body
tissues and fluids. Abnormal alkaline phosphatase levels are
associated with liver disease and bone and muscle damage.
A normal level is 35-125 IU/L.
ALKALOID: an organic compound found in plants.
ALLERGY: an abnormal immune response to an antigen (allergen)
that does not normally cause an adverse reaction (e.g., animal
dander, pollen). Allergic reactions are caused by the release
of histamine by mast cells, a type of white blood cell. Allergic
symptoms may include runny nose (rhinitis), skin rash, asthma,
and anaphylactic shock.
ALLOPATHY (adjective ALLOPATHIC): Western medicine; the conventional
medical practices used most often in the U.S.
ALOPECIA: hair loss.
ALPHA INTERFERON: see interferon-alpha.
ALPHA-FETOPROTEIN (AFP): a protein, measurable in the blood,
that is often elevated in people with liver cancer.
ALPHA LIPOIC ACID (THIOCTIC ACID): a compound that enhances
the antioxidant effect of vitamin C and vitamin E, and may
help reduce liver inflammation and protect liver cells from
damage.
ALT: see alanine aminotransferase.
ALTERNATIVE THERAPY: any type of treatment that is not considered
standard or conventional practice in a given culture. In Western
countries, traditional Chinese medicine, homeopathy, naturopathy,
and chiropractic are considered alternative therapies.
AMANTADINE (brand name SYMMETREL): a drug that is used to
treat influenza and is also under study as a treatment for
chronic hepatitis C.
AMENORRHEA: absence of menstrual periods.
AMERICANS WITH DISABILITY ACT (ADA): a federal law that requires
employers to offer certain protections and benefits (including
"reasonable accommodation") to persons with disabilities
that substantially limit major life activities.
AMINO ACID: an organic compound that is a basic structural
unit of peptides and proteins. There are over 100 amino acids,
eight of which are essential for human metabolism.
AMINOTRANSFERASE (TRANSAMINASE): an enzyme (e.g., ALT, AST)
produced by the liver that catalyzes the transfer of amino
acids. Abnormally high aminotransferase levels in the blood
suggest liver damage.
AMMONIA: a toxic metabolic byproduct that is normally excreted
in the urine.
AMNESIA: memory loss.
AMPLICOR/COBALT AMPLICOR: brand name of a PCR-based viral
load test for HCV and HIV.
ANALGESIC: a drug or therapy that reduces pain.
ANALINGUS (RIMMING): oral/anal sex.
ANECDOTAL: evidence based on reports of specific individual
cases rather than controlled clinical studies.
ANEMIA (adjective ANEMIC): reduced number of red blood cells
or reduced ability of blood to carry oxygen. There are several
types of anemia, all with different causes. Symptoms may include
fatigue, weakness, pale skin, and difficulty breathing.
ANESTHESIA (adjective ANESTHETIC): an agent that controls
pain. Localized anesthesia blocks pain in a given area; general
anesthesia produces unconsciousness.
ANUERYSM: an abnormally stretched, dilated section of a blood
vessel that is prone to bursting.
ANGINA PECTORIS: chest pain that occurs when the heart muscle
receives inadequate oxygen.
ANOREXIA: loss of appetite for food.
ANTIBIOTIC: an agent that kills or inhibits the growth of
bacteria.
ANTIBODY (IMMUNOGLOBULIN): a protein produced by plasma cells
(a type of immune system white blood cell) when they encounter
foreign invaders. Specific antibodies bind to specific invaders,
or antigens, and target them for destruction. The presence
of antibodies indicates current infection with or past exposure
to a pathogen.
ANTIBODY POSITIVE (SEROPOSITIVE): the presence in the blood
of antibodies against a specific pathogen such as HCV.
ANTIBODY TEST: an assay that detects the presence of antibodies
in a blood sample; ELISA and RIBA tests are used to detect
HCV antibodies.
ANTICOAGULANT: a drug that reduces or delays blood coagulation
or clotting.
ANTICONVULSANT: a drug that prevents or reduces convulsions
or seizures.
ANTIDEPRESSANT: a drug that elevates the mood and alleviates
mental depression. There are several types, including selective
serotonin reuptake inhibitors (SSRIs), MAO inhibitors, and
tricyclics.
ANTIEMETIC: a drug that relieves nausea and vomiting.
ANTIFIBROTIC: a drug or other agent than prevents or reduces
the development of liver fibrosis or cirrhosis.
ANTIGEN: any agent or substance that stimulates an immune
response. Antigens are often foreign invaders such as bacteria
or viruses.
ANTIHISTAMINE: a drug that blocks the action of histamine,
a chemical messenger in the body. Antihistamines are used
to prevent or alleviate allergic reactions and to reduce stomach
acid production.
ANTIOXIDANT: a substance that reduces oxidation by binding
with and neutralizing free radicals. The body produces natural
antioxidants, and they are also available in foods and dietary
supplements (e.g., vitamin E, selenium).
ANTIRETROVIRAL: a drug that suppresses the activity or replication
of retroviruses. Different types of antiretroviral drugs (e.g.,
reverse transcriptase inhibitors, protease inhibitors) interfere
with various stages of the virus life cycle.
ANTISENSE OLIGONUCLEOTIDE: an agent that blocks the synthesis
of disease-causing proteins by binding with and preventing
translation of RNA (genetic material). HCV antisense oligodeoxynucleotides
are directed against a specific HCV genetic sequence and inhibit
viral gene expression.
ANTIVIRAL: a drug that suppresses the activity or replication
of viruses.
ANXIOLYTIC: a drug that helps relieve mental anxiety.
APLASTIC ANEMIA: anemia due to a reduced level of red blood
cells caused by the inability of stem cells in the bone marrow
to produce new cells. Certain drugs suppress the bone marrow
and can lead to aplastic anemia as a side effect.
ARM: a group of participants in a clinical trial who receive
the same treatment (or placebo).
ARTERIOGRAPHY (ANGIOGRAPHY): examination
of arteries (after injection of a dye) to look for damage
and blockages.
ARTHRALGIA: joint pain.
ARTHRITIS: joint inflammation.
ASCITES: accumulation of fluid in the abdominal (peritoneal)
cavity. Ascites may be a symptom of advanced liver disease
with decompensated cirrhosis.
ASPARTATE AMINOTRANSFERASE (AST, formerly SGOT): an enzyme
(also called aspartate transaminase) produced in the liver.
When liver cells are damaged, AST is released. Elevated levels
may indicate liver disease, but are also seen in people with
muscle damage. A normal level is below 42 IU/L.
ASSAY: a test, especially one used to detect the presence
or amount of an agent in the blood or body tissues.
AST: see aspartate aminotransferase.
ASTRAGALUS: an herb used to stimulate the immune system. It
is an ingredient in many Chinese herbal formulas.
AS-TREATED ANALYSIS: a method of analyzing the results of
a clinical trial that includes only participants who successfully
complete a course of the treatment, excluding those who drop
out early. Contrast with intent-to-treat analysis.
ASYMPTOMATIC: not feeling or showing outward symptoms or signs
of a disease.
ATHEROSCLEROSIS: a condition in which blood vessels harden
and loose their elasticity due to the build-up of fatty material
(plaques).
AUTOANTIBODY: an antibody that targets the body's own tissues.
AUTOIMMUNE RESPONSE (AUTOIMMUNITY): a condition in which a
person's immune system produces antibodies that attack the
body's own tissues. Several conditions associated with advanced
hepatitis C (e.g., lichen planus, Sjögren's syndrome)
appear to have an autoimmune aspect.
AUTOIMMUNE THYROIDITIS: an inflammatory, autoimmune condition
in which the immune system attacks the thyroid gland.
AYURVEDA: a system of traditional medicine practiced in India.
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BACTERIUM (plural BACTERIA): a simple single-celled
microorganism. Bacteria are classified by their shape (e.g.,
rod, spirochete), staining properties (Gram positive or Gram
negative) and habitat (aerobic, anaerobic).
BASELINE: an initial or known value (e.g., ALT level, HCV
viral load) against which later measurements can be compared.
B-CELL (B-LYMPHOCYTE): a type of immune system white blood
cell. B-cells mature into plasma cells that produce antibodies.
bDNA: see branched-chain DNA assay.
BECK DEPRESSION INDEX: a written, self-report questionnaire
used to gauge clinical depression.
BENIGN: a mild, non-lethal illness, especially a non-cancerous
tumor. Contrast with malignant.
BIAS: in a clinical trial, a false association that results
from to the failure to account for some skewing or influencing
factor.
BID: taken twice daily.
BILE: a yellowish-green fluid produced by the liver that aids
in the digestion of fats and the excretion of toxins.
BILE DUCT: the passage that carries bile from the liver to
the small intestine.
BILIRUBIN: a yellowish pigment released when red blood cells
are broken down. Normally bilirubin is processed and excreted
by the liver. An excess level of bilirubin in the blood (hyperbilirubinemia)
may indicate liver damage, and can lead to jaundice (yellowing
of the skin and whites of the eyes), pale-colored stools,
and dark urine. A normal bilirubin level is below 1.3mg.
BINDING PROTEIN: a protein synthesized by the liver that binds
to and transports substances such as vitamins, minerals, hormones,
and fats.
BIOAVAILABILITY: the degree to which a drug or other substance
is absorbed and circulated in the body.
BIOCHEMICAL RESPONSE (BIOLOGICAL RESPONSE): a favorable response
to treatment as indicated by normalization of blood values
(e.g., liver enzyme levels).
BIOFEEDBACK: a technique in which people learn to use signals
from their own bodies to influence physiological functions.
BIOFLAVINOID (VITAMIN P): natural pigments found in fruits
and vegetables that increase absorption of vitamin C.
BIOLOGICAL RESPONSE: see biochemical response.
BIOPSY: a procedure in which a sample of cells or tissue is
taken for laboratory examination. Liver biopsies are used
to monitor liver disease progression in people with HCV.
BLINDING: a method of conducting clinical trials in which
participants do not know who is taking an experimental treatment,
a standard (control) treatment, or a placebo. In a blinded
study, the volunteers do not know what treatment (if any)
they are receiving. In a double-blind study, neither the volunteers
nor the researchers administering the treatment know who is
receiving what. Blinding is done to reduce bias in drug trials.
In the case of medical necessity, a study may be unblinded
to reveal who is receiving what treatment.
BLOOD-BORNE: a pathogen that is transmitted through direct
blood-to-blood contact, for example, through sharing dirty
needles or through a blood transfusion.
BLOOD TRANSFUSION: the infusion of blood or blood components
into an individual for the treatment of a medical condition.
Transfusions may be homologous (from a donor) or autologous
(previously stored blood from the recipient).
BMI: see body mass index.
BODY MASS INDEX (BMI): a measurement of body fat determined
by dividing a person's weight (in kilograms) by height (in
meters squared).
BODYWORK: healing techniques (e.g., massage therapy, reflexology)
that involve manipulating or applying pressure to the body.
BONE MARROW: the soft, spongy material inside certain long
bones where blood cells are produced.
BRAIN FOG: mild mental confusion, memory loss, and/or lack
of concentration and alertness. May be a symptom of toxic
chemical build-up due to impaired liver function. See hepatic
encephalopathy.
BRANCHED-CHAIN DNA ASSAY (bDNA): an test that measures the
amount of virus (viral load) in plasma or tissues using a
chemical signal emitted by viral genetic material.
BREAKTHROUGH: the return of detectable viral load or high
ALT levels in a person who had previously achieved a good
virological or biochemical treatment response.
BUDDING: the emergence of newly produced virus particles through
a host cell membrane.
BUPLEURUM: an herb traditionally used in Chinese medicine
to treat liver conditions.
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CANCER: a malignant neoplasm or tumor characterized by abnormal
cell proliferation. Types include carcinoma (which affects
epithelial cells), sarcoma (which affects soft tissues), lymphoma
and leukemia (which affect lymphoid tissue), and glioma (which
affects brain tissue).
CAPILLARIES: tiny blood vessels that deliver oxygen and nutrients
to and remove waste products from cells.
CARBOHYDRATE: an organic molecule composed mainly of carbon,
hydrogen, and oxygen atoms. Carbohydrates constitutes a major
class of nutrients, and are present in foods such as bread
and pasta.
CARCINOGEN: an agent that promotes the development of cancer.
CARCINOMA: a malignant tumor of the epithelial cells that
line body surfaces and cavities. Carcinoma in situ refers
to an early stage of cancer that has not invaded surrounding
tissues.
CARDIAC: having to do with the heart.
CARDIOVASCULAR: having to do with to the circulatory system
(the heart and blood vessels).
CARRIER: a person who does not show symptoms or have active
disease, but who carries an infectious organism and can transmit
it to others.
CASE STUDY: a description of a specific clinical case, that
is, the development of disease and response to treatment in
a single individual.
CASUAL CONTACT: non-intimate contact between individuals (e.g.,
hugging, eating, working together) that does not involve transfer
of body fluids and therefore does not pose a risk for transmission
of blood-borne diseases.
CATEGORY A, B, C, D, X: an FDA classification for drug safety
during pregnancy. Category A drugs have not shown a risk to
fetuses in controlled studies. Category X includes drugs which
animal and human studies or common experience have shown to
cause fetal abnormalities or miscarriages.
CD4 CELL (CD4 LYMPHOCYTE, T-HELPER CELL): a type of white
blood cell that helps the body fight infection.
CD4 CELL COUNT: the number of CD4 lymphocytes in one cubic
millimeter (mm3) of blood. The CD4 count is one indicator
of the progression of HIV disease. A CD4 count below 200 cells/mm3
is a diagnostic criteria for AIDS.
CD8 CELL (CD8 LYMPHOCYTE): a type of white blood cell that
helps regulate and/or carry out the body's immune response.
CD8 cells include T-suppressor cells and cytotoxic T-lymphocytes.
CDC: see Centers for Disease Control and Prevention.
CELL: the basic unit of living organisms. A cell contains
a nucleus and a cell wall (in plants) or a cell membrane (in
animals) which surrounds the cellular material, called cytoplasm.
CENTERS FOR DISEASE CONTROL AND PREVENTION (CDC): the U.S.
federal government agency within the Department of Health
and Human Services that monitors the occurrence of diseases
and develops policies for preventing disease and maintaining
the health of the population.
CENTRAL NERVOUS SYSTEM (CNS): the brain and spinal cord.
CEPLENE: see histamine dihydrochloride.
CEREBROVASCULAR: having to do with the flow of blood to the
brain.
CEREBROVASCULAR ACCIDENT: see stroke.
CESAREAN SECTION (C-SECTION): a delivery procedure that involves
making an incision through the abdominal wall to remove an
infant from the uterus (womb).
CFIDS: chronic fatigue immune dysfunction syndrome. See chronic
fatigue syndrome.
CHEMOKINE: a chemical, secreted by certain immune system cells,
that acts as a messenger between cells and stimulates the
activity of cells.
CHEMOTHERAPY: the use of drugs to treat disease.
CHIROPRACTIC: a system of treatment based on manipulation
of the spine.
CHOLAGOGUE: an agent (especially an herb) that improves bile
flow.
CHOLANGITIS: inflammation of the bile duct, often characterized
by jaundice.
CHOLESTASIS: obstruction of the flow of bile between the liver,
the gall bladder, and the small intestine.
CHOLESTEROL: a fatty substance in animal tissue that is an
essential component of cell membranes, certain hormones, and
nerve fiber insulation. Cholesterol is manufactured by the
liver, and is also present in certain foods. There are two
primary types of cholesterol in the blood, low-density lipoprotein
(LDL), which is considered a risk factor for heart disease;
and high-density lipoprotein (HDL), which is considered protective.
CHRONIC: a long-term or persistent disease. Contrast with
acute.
CHRONIC ACTIVE HEPATITIS: a condition in which HCV or HBV
continues to replicate and infect new cells after six months.
CHRONIC FATIGUE SYNDROME (CHRONIC FATIGUE
IMMUNE DYSFUNCTION SYNDROME, CFIDS): an illness characterized
by prolonged fatigue, neurological problems, joint and muscle
pain, and/or impairment of the ability to function normally
for six months or longer.
CHRONIC HEPATITIS: liver inflammation lasting longer that
six months.
CIRRHOSIS: a type of liver damage in which normal liver cells
are replaced with fibrous scar tissue. In compensated cirrhosis,
the liver is damaged but can still function. In decompensated
cirrhosis, liver function is severely impaired and scar tissue
interferes with normal blood flow through the liver, potentially
leading to bleeding varices, ascites, "brain fog,"
and other symptoms.
CLEARANCE: removal or elimination, e.g., of a virus or drug
from the body.
CLINICAL: relating to the treatment of patients. A clinical
observation is based on a person's observed condition and
symptoms, as distinguished from laboratory findings.
CLINICAL TRIAL (CLINICAL STUDY): an organized procedure for
determining the effectiveness of a new drug or therapy by
administering the agent to volunteers under controlled conditions.
In many clinical trials, new treatments are compared against
older standard treatments or an inactive substance (placebo).
CLOT: a sticky mass of coagulated blood cells and platelets.
CLOTTING FACTOR (COAGULATION FACTOR): a protein (e.g., fibrinogen,
prothrombin, Factor VIII) that is necessary for normal blood
clotting. Several clotting factors are synthesized by the
liver and production may be impaired when the liver is damaged.
People with clotting factor deficiencies may experience prolonged
bleeding and easy bruising.
COBALAMIN: see vitamin B12.
COEMZYME Q10: an antioxidant agent that is necessary for the
proper activity of certain enzymes.
COFACTOR: a factor that influences the progression of a disease
or the action of a disease-causing agent.
COGNITIVE DYSFUNCTION: reduction in mental functioning and
ability to carry out tasks that require thinking, planning,
and memory.
COHORT: a group of individuals in a study who share a demographic,
clinical, or other characteristic.
COINFECTION: concurrent infection with more than one disease-causing
organism (e.g., HCV and HIV).
COLONY-STIMULATING FACTOR (CSF): a cytokine responsible for
regulating the production of white blood cells. Types include
granulocyte colony-stimulating factor (G-CSF) and granulocyte
macrophage colony-stimulating factor (GM-CSF).
COLOSTRUM: breast fluid produced during the first few days
after a baby's birth (prior to milk production) that contains
proteins, immunoglobulins, and immune cells.
COMA: a state of deep unconsciousness; a vegetative state.
COMBINATION THERAPY: use of two or more drugs together to
improve the effectiveness of treatment. In HCV treatment,
the term most often refers to the use of interferon plus ribavirin.
Contrast with monotherapy.
COMPASSIONATE USE: an FDA classification that allows individuals
to use experimental drugs prior to their approval for a serious
illness for which there is no other suitable treatment.
COMPENSATED CIRRHOSIS: see cirrhosis.
COMPLEMENTARY THERAPY: an alternative therapy that is used
in conjunction with a standard Western treatment.
COMPLETE BLOOD COUNT (CBC): an inventory of the cellular components
of the blood, including red blood cell count, hematocrit and
hemoglobin, white blood cell count, and platelet count.
COMPUTED TOMOGRAPHY SCAN (CT SCAN): a method of viewing the
soft tissues of the body using X-rays.
CONDOM: a sheath made of latex, polyurethane, or animal membrane
that is worn over the penis to hold ejaculated semen. Condoms
are used to prevent pregnancy; latex and polyurethane condoms
also protect against HIV, HCV and certain other sexually transmitted
diseases. The "female condom" (Reality) is an internal
pouch worn inside the vagina or anus.
CONFIDENCE INTERVAL: a statistical measure of the likelihood
that an experimental result is "true" and not the
result of chance alone.
CONGENITAL: present from birth.
CONGESTIVE HEART FAILURE: heart dysfunction that leads to
a build-up of fluids in the body.
CONJUNCTIVITIS: inflammation of the conjunctiva, a membrane
that cover the eye and lines the eyelid.
CONSENSUS INTERFERON: a preparation that contains a variety
of different types of interferon.
CONTRACEPTION: birth control; a device or method that prevents
conception (fertilization), implantation, or successful gestation.
CONTRAINDICATION: any circumstance or condition that makes
a drug or other method of treatment inadvisable in a particular
case.
CONTROL ARM: a comparison group in a clinical trial that is
used to verify an experimental result. A control group is
typically given an older standard treatment or a placebo rather
than the new experimental treatment under study.
CONTROLLED TRIAL: a clinical trial in which a group receiving
an experimental treatment is compared to a control group that
is given a standard treatment or a placebo.
CORE: the inner part of a virus that contains its genetic
material.
CORONARY ARTERY DISEASE: damage to or blockage of the arteries
that provide blood to the heart muscle.
CORTICOSTEROID: a steroid hormone (e.g., prednisone, cortisone)
produced by the cortex of the adrenal gland or manufactured
synthetically. Corticosteroids have anti-inflammatory and
immunosuppressive properties, and are used to treat a variety
of conditions.
CREATININE: a metabolic byproduct produced by muscles; high
levels in the blood may indicate kidney dysfunction.
CREST SYNDROME: a type of scleroderma characterized by a variety
of different symptoms (primarily calcinosis, Raynaud's phenomenon,
esophageal dysfunction, sclerodactyly, and telangiectasia).
CRYOGLOBULIN: an abnormal immune protein.
CRYOGLOBULINEMIA: a condition in which cryoglobulins form
in the blood. When the blood is cooled, the cryoglobulins
clump together, causing the blood to thicken and restricting
blood flow. Essential mixed cryoglobulinemia occurs in many
people with HCV, although most do not experience symptoms.
CRYOSURGERY: removal of damaged or cancerous tissue by freezing.
CT SCAN: see computed tomography scan.
CULTURE: a method of growing a microorganism in a laboratory.
CUNNILINGUS: oral sex on a woman; contact between the mouth
and the vulva or vagina.
CUTANEOUS: relating to the skin.
CYSTEINE: an amino acid; one of the building blocks of glutathione.
CYTOKINE: a chemical messenger (e.g., interferon, interleukin,
tumor necrosis factor) produced by white blood cells. Cytokines
coordinate several aspects of the immune response, including
stimulating antibody production and activating killer T-cells.
CYTOPENIA: low levels of blood cells.
CYTOPLASM: the material that makes up the interior of a cell.
CYTOPROTECTIVE: an agent that protects cells from damage.
CYTOTOXIC T-LYMPHOCYTE (CTL, KILLER T-CELL): a type of CD8
white blood cell that targets and kills cells infected with
viruses, bacteria, parasites, and other microorganisms.
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DATA (singular DATUM): factual information,
especially results of an experiment or clinical trial.
DATA AND SAFETY MONITORING BOARD (DSMB): a group of experts
that evaluates clinical trials for safety and ethics. DSMBs
typically examine interim data as a trial progresses and determine
whether it should be stopped or allowed to continue.
DECOMPENSATED CIRRHOSIS: see cirrhosis.
DEHYDRATION: loss or lack of water in the body. Dehydration
may result from prolonged vomiting or diarrhea, and may disrupt
many bodily processes.
DELIRIUM: a state of mental confusion, typically acute and
rapid in onset, that may be caused by factors including disease,
drug use, or high fever.
DELTA HEPATITIS: see hepatitis D.
DEMENTIA: chronic loss of mental capacity. Dementia may involve
progressive deterioration of thinking, memory, and motor function,
and may also be associated with personality changes and psychological
symptoms such as depression.
DEMOGRAPHICS: the characteristics of a population (e.g., sex,
race, age).
DENTAL DAM: a flat square of latex or plastic, traditionally
used for dental surgery, that can be used to protect against
the spread of sexually transmitted diseases during oral sex.
DEOXYRIBONUCLEIC ACID (DNA): a double-stranded nucleic acid
that encodes genetic information. DNA is made up of four chemical
building blocks (nucleotides): adenine, cytosine, guanine,
and thymine.
DEPRESSION (DYSTHYMIA): a mood disorder characterized by prolonged
sadness or grief.
DETOXIFICATION: removal of toxic (poisonous) substances. Detoxification
of the blood is an important function of the liver.
DIABETES MELLITUS: a disease caused by insufficient insulin
production or lack of responsiveness to insulin. Type 1 (insulin-dependent
or juvenile-onset) diabetes results from an inability of the
body to produce insulin. Type 2 (non-insulin-dependent or
adult-onset) diabetes occurs later is life and is associated
with decreased insulin production or insulin resistance.
DIAGNOSIS: the determination of the existence of a disease
or condition. Diagnosis generally involves an evaluation of
a person's medical history, clinical symptoms, and laboratory
test results.
DIARRHEA: frequent, loose bowel movements. Diarrhea may be
caused by a variety of factors, including microorganisms and
as a side effect of certain drugs. Persistent diarrhea can
lead to dehydration and inadequate nutrient absorption.
DIETITIAN: a medical professional specializing in dietetics,
the study of nutrition and the use of special diets to prevent
and treat disease.
DISCORDANT: not having the same serostatus, for example a
couple in which one partner is HCV positive and the other
is HCV negative.
DIURETIC: an agent that increases loss of water from the body
through urination.
DNA: see deoxyribonucleic acid.
DOSAGE: the amount of a drug that is given at one time.
DOSE-RANGING TRIAL: a clinical trial in which different doses
of a drug are compared to determine which dosage has the best
balance of effectiveness and acceptable side effects.
DOSHA: one of the three bodily humors (vata, pitta, and kapha,)
recognized in Ayurvedic medicine.
DOUBLE-BLIND: see blinding.
DRUG INTERACTION: a phenomenon that occurs when multiple drugs
are taken together or drugs are taken with certain herbs or
foods. Drug interactions may enhance or reduce the action
of a drug and may increase its side effects.
DYSFUNCTION: lack or loss of normal function.
DYSPLASIA (adjective DYSPLASTIC): abnormal cell or tissue
growth.
DYSTHYMIA: see depression.
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ECZEMA: a type of skin rash.
EDEMA: swelling caused by accumulation of fluid in body tissues.
EFFICACY: effectiveness; the ability to achieve a desired
result.
ELISA/ELISA II: see enzyme-linked immunosorbent assay.
EMBOLISM: a blood clot that travels through the bloodstream
and becomes lodged in a blood vessel, causing a blockage.
ENCEPHALOPATHY: disease of the brain. See also hepatic encephalopathy.
END-OF-TREATMENT (EOT) RESPONSE: the disappearance of detectable
HCV RNA from the blood at the end of a course of treatment.
ENDOCRINE: endocrine glands are ductless glands that regulate
bodily functions via hormones secreted into the bloodstream.
The endocrine system includes the hypothalamus, pituitary
gland, thyroid, adrenal glands, and gonads (ovaries and testes).
ENDOSCOPY: a method of examining the interior of a body cavity
or hollow organ (e.g., esophagus, stomach) using an endoscope,
a narrow, flexible fiber optic instrument that conducts light.
ENDOTHELIUM (adjective ENDOTHELIAL): a layer of cells that
lines blood and lymph vessels, the heart, and various body
cavities.
ENDPOINT: a marker of disease progression. Endpoints may be
clinical manifestations (e.g., disease symptoms, death) or
laboratory results such as ALT level or viral load (sometimes
called surrogate markers).
END-STAGE RENAL DISEASE (ESRD): kidney failure.
ENROLLMENT CRITERIA: factors used to determine whether a person
is eligible to participate in a clinical trial. See also inclusion
criteria, exclusion criteria.
ENTERIC: having to do with the intestines.
ENTERIC HEPATITIS: see hepatitis E.
ENVELOPE: the outer coat of a virus.
ENZYME: a protein that induces or accelerates a chemical reaction.
ENZYME-LINKED IMMUNOSORBENT ASSAY (ELISA, ELISA II): a laboratory
test used to detect the presence of antibodies in the blood.
EOT: see end-of-treatment response.
EPIDEMIOLOGY: the study of the frequency, distribution, and
behavior of a disease within a population.
EPIVIR: see lamivudine.
EPO: see erythropoietin.
EPOGEN: see erythropoietin.
ERADICATION (verb ERADICATE): the complete elimination of
an organism from the body.
ERYTHROCYTE: a mature red blood cell. Erythrocytes transport
oxygen to the tissues of the body.
ERYTHROPOIETIN (EPOIETIN, EPO): a hormone produced by the
kidneys that stimulates the production of red blood cells.
Genetically engineered EPO (brand names Procrit, Epogen) is
used to treat certain types of anemia.
ESOPHAGUS (adjective ESOPHAGEAL): the swallowing tube; the
portion of the digestive tract between the mouth and the stomach.
ESRD: see end-stage renal disease.
ESSENTIAL MIXED CRYOGLOBULINEMIA: see cryoglobulinemia.
ESTROGEN: the primary female sex hormone or a synthetic analog.
Estrogens stimulate the development of female secondary sex
characteristics and regulate the reproductive cycle in women.
ETIOLOGY: the cause of a disease.
EXACERBATE: to worsen or make more severe.
EXCLUSION CRITERIA: conditions that disqualify someone from
participating in a clinical trial. Contrast with inclusion
criteria.
EXPERIMENTAL ARM: the group of participants in a clinical
trial that receives the new experimental treatment under study.
EXPERIMENTAL DRUG: a new drug that is being tested as a treatment
for a specific condition and has not yet been approved by
the FDA for use.
EXTRAHEPATIC: outside the liver.
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FACTOR VIII: a protein synthesized by the
liver that is necessary for proper blood clotting.
FAILURE TO THRIVE: a condition in which an infant loses or
fails to gain weight and develops at a slower rate than expected.
FALSE-NEGATIVE: a negative test result in a person who in
fact has the disease or condition being tested. Contrast with
false-positive.
FALSE-POSITIVE: a positive test result in for a person who
in fact does not have the disease or condition being tested.
Contrast with false-negative.
FASCICULATION: an involuntary muscle contraction.
FATIGUE: unusual, prolonged, or excessive tiredness.
FAT-SOLUBLE: capable of being dissolved in fat. Contrast water-soluble.
FATTY ACID: an organic molecule made up of a hydrocarbon chain
and a carboxylic acid group. Fatty acids may be saturated,
monounsaturated, or polyunsaturated.
FDA: see Food and Drug Administration.
FEBRILE: having a fever or increased body temperature.
FECAL-ORAL ROUTE: a route of transmission of infectious organisms
which involves the transfer of fecal matter to the mouth (e.g.,
by ingesting contaminated food or water, oral/anal sex).
FECES (adjective FECAL): excrement; excreted waste matter.
FELLATIO: oral sex on a man; contact between the mouth and
the penis.
FEMALE CONDOM: see condom.
FIBROMYALGIA (FIBROMYOSITIS): a condition characterized by
pain throughout the body, often accompanied by fatigue.
FRIBROMYOSITIS: see fibromyalgia.
FIBROSIS (adjective FIBROTIC): liver damage in which fibrous
tissue develops and replaces normal cells.
FIBRINOGEN: a factor produced by the liver that is necessary
for proper blood clotting.
FILGRASTIM: see granulocyte colony-stimulating factor.
FINE-NEEDLE ASPIRATION BIOPSY: a type of liver biopsy in which
a tissue sample is withdrawn using a very fine needle.
FLARE (FLARE-UP): a sudden, acute worsening of disease symptoms.
FLATULENCE: excessive intestinal gas.
FLAVIVIRUS: a group of viruses, several of which cause diseases
in humans. HCV is related to flaviviruses, and some taxonomists
consider the Hepacivirus genus to be part of the Flaviviridae
family.
FLUMADINE: see rimantadine.
FOLIC ACID (FOLATE): a vitamin necessary for red blood cell
production and proper neurological function; folic acid also
helps prevents neural tube defects in fetuses.
FOOD AND DRUG ADMINISTRATION (FDA): the U.S. federal agency
responsible for regulating the development, use, and safety
of drugs, medical devices, cosmetics, and related products.
The FDA approves new experimental drugs based on the results
of clinical trials.
FOOD GUIDE PYRAMID: a diagram showing what foods are included
in a balanced diet. A healthy diet includes 6-11 servings
of breads and grains (the bottom level of the pyramid); 3-5
servings of vegetables; 2-4 servings of fruit; 2-3 servings
of meat, fish, beans, or nuts; 2-3 servings of dairy products;
and limited fats and oils.
FREE RADICAL: a molecule that contains an unpaired electron.
Free radicals are a byproduct of normal metabolism. They are
highly reactive and bind with other molecules. The "theft"
of electrons by free radicals can disrupt normal cellular
processes and cause cellular damage (oxidative stress). See
also antioxidant.
FULMINANT: an unusually severe or aggressive form of a disease.
FULMINANT HEPATITIS: a severe, life-threatening form of hepatitis.
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GALL BLADDER: an organ beneath the liver
where bile is stored.
GAMMA GLOBULIN: a preparation of antibodies injected to prevent
or treat infection. Gamma globulin is used as postexposure
prevention for hepatitis A and hepatitis B.
GAMMA-GLUTAMYL TRANSPEPTIDASE (GGT): a liver enzyme. Elevated
GGT levels may indicate bile obstruction and liver damage.
A normal GGT level is 30-60 IU/L.
GAN CAO: see licorice root.
GASTROENTERITIS: inflammation of the stomach and intestines.
GASTROENTEROLOGY (also GASTROENTEROLOGIST): the medical specialty
that deals with the digestive system; a gastroenterologist
treats digestive diseases.
GASTROINTESTINAL: having to do with the digestive system,
especially the stomach and intestines.
GASTROINTESTINAL TRACT: the digestive tube consisting of the
mouth, esophagus, stomach, small intestine, large intestine,
and anus.
GB VIRUS C (GBV-C): see hepatitis G virus.
G-CSF: see granulocyte colony-stimulating factor.
GENE (adjective GENETIC): the basic unit of heredity. Genes
contain hereditary information encoded in the form of DNA
(or RNA in some viruses). In animal and plant cells, genes
are located on the chromosome in a cell's nucleus.
GENE THERAPY: an approach to preventing or treating disease
by replacing, removing, or introducing genes, or otherwise
manipulating genetic material.
GENERIC DRUG: a drug that is not protected by a patent and
may be produced by any manufacturer.
GENERIC NAME: a common name used to identify a drug, as opposed
to a brand name used by a particular company for marketing
(e.g., pegylated interferon is the generic name of the drug
marketed under the brand names Peg-Intron and Pegasys).
GENETIC ENGINEERING: manipulation of an organism's genetic
material to modify the proteins it produces.
GENETIC MATERIAL: deoxyribonucleic acid (DNA) and ribonucleic
acid (RNA), the molecules that carry hereditary information.
GENOME: the complete genetic code or "blueprint"
of an organism.
GENOTYPE: the genetic makeup of an organism. HCV has six major
genotypes (designated by the numbers 1 through 6). In the
U.S., genotype 1a/b is most prevalent, and also more difficult
to treat. See also quasispecies.
GI: see gastrointestinal.
GLOBULIN: see immunoglobulin.
GLOMERULUS (plural GLOMERULI): a small capillary bed in the
kidney where blood filtration takes place.
GLOMERULONEPHRITIS: an inflammatory disorder of the glomeruli,
often due to the build-up of cryoglobulins.
GLUCONEOGENESIS: the conversion of glycogen to glucose in
the liver.
GLUCOSE (BLOOD SUGAR): a form of sugar that is the body's
primary fuel. The liver stores glucose after meals and releases
it again as needed. Abnormally low or high levels of glucose
in the blood may indicate a metabolic disturbance (e.g., diabetes).
GLUCOSE-6-PHOSPHATE DEHYDROGENASE (G6PD): a human red blood
cell enzyme. G6PD deficiency can cause severe anemia.
GLUTATHIONE: a natural antioxidant found in the body.
GLYCINE: an amino acid; one of the building blocks of glutathione.
GLYCOGEN: a carbohydrate stored in body tissues. The liver
converts glucose from food into glycogen and stores it for
later use. When needed, the liver converts glycogen back into
glucose.
GLYCYRRHIZIN: see licorice root.
GM-CSF: see granulocyte macrophage colony-stimulating factor.
GRAFT: a transplanted organ or tissue.
GRANULOCYTE: a type of immune system white blood cell (e.g.,
neutrophil, basophil, eosinophil) that releases toxic chemicals
to kill invading microorganisms and mediate allergic reactions.
GRANULOCYTE COLONY-STIMULATING FACTOR (G-CSF): a cytokine
that stimulates the production of granulocytes. Genetically
engineered G-CSF (filgrastim; brand name Neupogen) is used
to treat neutropenia.
GRANULOCYTE MACROPHAGE COLONY-STIMULATING FACTOR (GM-CSF):
a cytokine that stimulates growth of granulocytes and macrophages,
two types of white blood cell. Genetically engineered GM-CSF
(sargramostim; brand names Leukine, Prokine) is used to treat
neutropenia.
GRANULOCYTOPENIA: an abnormally low number of granulocytes
in the circulating blood, which may lead to an increased risk
of bacterial infection. In practice, the term is used to refer
to neutropenia.
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HALF-LIFE: the time required for half
of the original amount of a drug to be eliminated from the
body, or for a drug to decrease to half its original concentration
in the blood.
HAS: see hepatic arterial stenosis.
HAT: see hepatic arterial thrombosis.
HCC: see hepatocellular carcinoma.
HCT: see hematocrit.
HCV RNA: the genetic material of the hepatitis C virus. A
detectable level of HCV RNA on a viral load test indicates
that HCV is actively replicating.
HELICASE INHIBITOR: a drug that inhibits the action of a virus'
helicase enzyme, thus preventing the viral genetic material
from unwinding, and interfering with viral replication.
HEMATOCRIT (HCT): the percentage of red blood cells in a given
amount of whole blood; the hematocrit reflects the oxygen-carrying
capacity of the blood. A normal hematocrit is 40-54% for adult
men and 37-47% for adult women.
HEMATOLOGICAL: having to do with the blood.
HEMATOPOIESIS: the production of blood cells in the bone marrow.
Hematopoietic stem cells give rise to all types of red and
white blood cells.
HEME: the iron-based pigment in red blood cells, a component
of hemoglobin that is released when red blood cells are broken
down.
HEMOCHROMATOSIS: iron overload disease; a disease in which
iron is not properly metabolized and builds up in tissues
throughout the body, especially in the liver.
HEMOGLOBIN: the red, iron-based pigment in red blood cells
that enables them to transport oxygen. Also refers to a test
of the amount of hemoglobin in red blood cells.
HEMOLYSIS: the breakdown or destruction of red blood cells.
HEMOLYTIC ANEMIA: a low red blood cell count due to excessive
cell destruction.
HEMOPHILIA: a hereditary disease in which a person does not
produce sufficient blood clotting factors and is prone to
prolonged bleeding.
HEMORRHAGE: bleeding.
HEPACIVIRUS: a genus of viruses that includes HCV.
HEPATIC: having to do with the liver; also, an herbal remedy
used to treat liver conditions.
HEPATIC ARTERIAL STENOSIS (HAS): narrowing of the hepatic
artery.
HEPATIC ARTERIAL THROMBOSIS (HAT): the formation of clots
in the hepatic artery.
HEPATIC ARTERY: the blood vessel that delivers oxygen-rich
blood to the liver.
HEPATIC COMA: loss of consciousness due to advanced liver
disease. When the liver is damaged, it cannot remove toxins
from the body; these toxins build up in the bloodstream causing
brain damage and other symptoms. Hepatic coma is an indication
of advanced liver failure.
HEPATIC ENCEPHALOPATHY: impaired brain function due to advanced
liver damage; this occurs when the damaged liver can no longer
effectively filter toxins from the bloodstream.
HEPATIC PANEL: see liver function tests.
HEPATIC RESECTION: surgical removal of part of the liver;
may be done to treat liver cancer.
HEPATIC VEIN: the blood vessel that carries filtered blood
from the liver to the heart.
HEPATITIS: inflammation of the liver. Hepatitis may have various
causes, including viruses, toxins, and heavy alcohol consumption.
HEPATITIS A (INFECTIOUS HEPATITIS): a viral disease of the
liver that is primarily transmitted by the fecal-oral route.
Symptoms may include fever, fatigue, nausea, and jaundice.
Hepatitis A typically resolves on its own and does not become
chronic. There is no standard treatment for hepatitis A, but
an effective vaccine is available.
HEPATITIS A VIRUS (HAV): the virus that
causes hepatitis A.
HEPATITIS B (SERUM HEPATITIS): a viral
disease of the liver. Hepatitis B is a blood-borne disease,
but may also be transmitted sexually transmitted or vertically
from mother to child. Symptoms may include fever, fatigue,
abdominal pain, jaundice, and elevated liver enzymes.
Hepatitis B becomes chronic in about 5-10% of infected adults.
Standard treatments for hepatitis B are interferon and
lamivudine; an effective vaccine is available.
HEPATITIS B
IMMUNOGLOBULIN (HBIG): a preparation of antibodies
administered as postexposure prophylaxis to prevent illness in
people exposed to the hepatitis B virus.
HEPATITIS B
VIRUS (HBV): the virus that causes hepatitis B.
HEPATITIS C
(formerly NON-A/NON-B HEPATITIS): a viral disease of the
liver. Hepatitis C is a blood-borne disease; in rare cases it
may be transmitted sexually or vertically from mother to
child. Symptoms may include fever, fatigue, abdominal pain,
jaundice, and elevated liver enzymes. Chronic hepatitis C can
lead to long-term liver damage. Standard treatment for
hepatitis C is a combination of interferon (standard or
pegylated) plus ribavirin; there is currently no vaccine.
HEPATITIS C
VIRUS (HCV): the virus that causes hepatitis C.
HEPATITIS D
(DELTA HEPATITIS): a viral disease of the liver. Hepatitis D
is caused by a blood-borne virus that only causes disease in
people already infected with hepatitis B.
HEPATITIS D
VIRUS (HDV): the virus that causes hepatitis D.
HEPATITIS E
(ENTERIC HEPATITIS): a viral disease of the liver. Hepatitis E
is spread through the fecal-oral route. The disease is rare in
the U.S., but common in Africa and Asia. It is usually mild,
but may be severe and possibly fatal in pregnant women.
HEPATITIS E
VIRUS (HEV): the virus that causes hepatitis E.
HEPATITIS G
VIRUS (HGV, GB VIRUS C, GBV-C): a recently discovered
blood-borne virus that appears to be related to hepatitis C.
It is not known to cause disease.
HEPATOCELLULAR CARCINOMA (HCC): a type of
primary liver cancer seen in some people with long-term liver
damage due to chronic hepatitis C or hepatitis B.
HEPATOCYTE: a
working liver cell.
HEPATOLOGY (also HEPATOLOGIST): the
medical specialty that deals with the liver; a hepatologist
treats liver disease.
HEPATOMEGALY: enlargement of the liver.
HEPATOTOXICITY (adjective HEPATOTOXIC):
toxic or poisonous to the liver.
HERBALISM (HERBAL THERAPY): the medicinal
or therapeutic use of plants or plant products.
HISTAMINE: a
cellular compound that is released in response to an allergen
and causes the symptoms of allergic reactions.
HISTAMINE
DIHYDROCHLORIDE (brand name CEPLENE, formerly MAXIMINE): a
histamine analog being studied as a treatment for chronic
hepatitis C.
HISTOLOGY (adjective HISTOLGICAL): the
study or examination of body tissues. In people with HCV,
histological improvement refers to improved liver tissue
health, including decreased inflammation and reduced fibrosis
or cirrhosis.
HISTOLOGICAL RESPONSE: an improvement in
liver tissue condition (e.g., reduced inflammation) in
response to treatment.
HIV: see human immunodeficiency virus.
HIV DISEASE:
infection with the human immunodeficiency virus, which attacks
the body's immune system. AIDS is the late, symptomatic stage
of HIV disease.
HOMEOPATHY: an alternative healing system
based on the theory that "like cures like." Homeopathic
therapy uses extremely diluted doses of substances that
normally cause the types of symptoms being treated.
HORMONE: a
chemical messenger (e.g., adrenaline, testosterone) involved
in the regulation and coordination of bodily or cellular
functions. Hormones may act locally or be secreted into the
bloodstream.
HORMONE REPLACEMENT THERAPY (HRT): the
administration of hormones to replace those that the body is
unable to produce; typically refers to estrogen replacement
therapy in postmenopausal women.
HOST CELL: a cell infected with a virus
or other microorganism.
HUMAN IMMUNODEFICIENCY VIRUS (HIV): a
slow-acting retrovirus associated with AIDS. HIV is
transmitted through blood-to-blood contact, sexual activity,
or from mother to child.
HUMAN LEUKOCYTE ANTIGEN (HLA): a genetic
marker of "self" which prevents the immune system from
attacking the body's own tissues.
HYPERBILIRUBINEMIA: an excess level of
bilirubin in the blood, characterized by jaundice,
pale-colored stools, and dark urine.
HYPERCHOLESTEREMIA: a high level of
cholesterol in the blood.
HYPERGLOBULINEMIA: an abnormally high
level of immunoglobulins (antibodies) in the blood.
HYPERGLYCEMIA: high
blood sugar.
HYPERTENSION: high blood pressure.
HYPERTHYROIDISM:
increased thyroid gland activity and thyroid hormone
overproduction
HYPOALBUMINEMIA: a low level of the blood
protein albumin.
HYPOTHYROIDISM: decreased thyroid gland
activity and reduced thyroid hormone production.
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top
IBUPROFEN: a
nonsteroidal anti-inflammatory drug used to relieve pain and
reduce fever. Advil, Aleve, and Motrin are common brand names.
IDIOPATHIC:
a term used to describe a disease or condition of unknown
cause or origin.
IDU: see injection drug user.
IFN: see
interferon.
IG: immunoglobulin. see antibody.
IMMUNE GLOBULIN:
see antibody.
IMMUNE RESPONSE: the activity of the
immune system, for example against an outside invader (e.g.,
bacteria, virus), cancerous cells, or the body's own tissues
(autoimmune response).
IMMUNE SYSTEM: the body's defense system
that protects against foreign invaders (e.g., bacteria,
viruses). Some immune defenses are nonspecific (e.g.,
phagocytosis), while others are directed against specific
invaders (e.g., antibody production). Organs of the immune
system include the lymph nodes, spleen, thymus, and tonsils.
IMMUNITY:
resistance to disease; the body's ability to recognize and
defend against outside invaders and cancerous cells. Immunity
may be either natural or acquired (for example, artificially
induced through a vaccine).
IMMUNIZATION: the process by which a
person is protected against illness caused by a pathogen
(e.g., bacteria, virus). Active immunization (vaccination)
involves exposing a person to antigens to prompt the body to
mount an immune response (e.g., production of antibodies).
Passive immunization involves the injection of an antibody
preparation (e.g., gamma globulin).
IMMUNOCOMPETENT:
capable of mounting an immune response.
IMMUNOCOMPROMISE: see
immunodeficiency.
IMMUNODEFICIENCY: inability of the immune
system to work properly, resulting in increased susceptibility
to disease.
IMMUNOGLOBULIN: see antibody.
IMMUNOMODULATOR:
an agent that influences the body's immune response.
IMMUNOSUPPRESSION: see immunodeficiency.
IMMUNOSUPPRESSIVE: a drug or other agent
that decreases immune system function.
IMMUNOTHERAPY
(IMMUNE-BASED THERAPY): a therapy that attempts to modify or
enhance the immune response or reconstitute a damaged immune
system.
IMPDH INHIBITOR: see inosine
monophosphate dehyrogenase inhibitor.
INCIDENCE (also
INCIDENCE RATE): the number of new cases of a disease or
condition in a specific population during a given period of
time. The incidence rate is determined by dividing the number
of new cases by the total population. Contrast with
prevalence.
INCLUSION CRITERIA: conditions that a
person must meet in order to be eligible for a clinical trial.
Contrast with exclusion criteria.
INCUBATION PERIOD: the period of time
between initial exposure to an infectious microorganism and
the development of disease symptoms.
INDUCTION
THERAPY: the initiation phase of a particular treatment.
Typically induction therapy uses higher or more frequent doses
of a drug. Contrast with maintenance therapy.
INFECTION: a
condition in which the body is invaded by an infectious
organism (e.g., bacteria, virus, fungus).
INFECTIOUS: a
disease or condition that can be transmitted from one person
to another.
INFECTIOUS HEPATITIS: see hepatitis A.
INFERGEN:
brand name of interferon alfacon 1 consensus interferon,
produced by Amgen/InterMune.
INFLAMMATION: the body's response to
tissue injury or infection, typically characterized by
redness, swelling, heat, and pain.
INFORMED
CONSENT: a mechanism designed to protect subjects in clinical
trials. Before entering a trial, participants must sign a form
stating that they have been given and understand important
information about the trial (including possible risks and
benefits) and voluntarily agree to take part.
INFUSION: direct
injection (e.g., of a drug, nutrients) into the bloodstream.
INHIBITOR:
an agent that inhibits or blocks an activity.
INJECTION DRUG
USER (IDU): a person who uses an illegal drug (e.g., heroin,
cocaine) administered with a needle and syringe. The term
intravenous drug user (IVDU) is also sometimes used.
INOSINE
MONOPHOSPHATE DEHYDROGENASE (IMPDH)
INHIBITOR: an agent (e.g., ribavirin)
that interferes with the synthesis and storage of guanine,
thus inhibiting viral replication.
INSOMNIA: inability to sleep.
INSTITUTIONAL
REVIEW BOARD (IRB): a multidisciplinary group that reviews and
ensures the ethical conduct of clinical trials that include
human participants.
INSULIN: a peptide hormone produced in
the pancreas that enables cells to use glucose. Lack of or
insensitivity to insulin results in diabetes.
INSULIN
RESISTANCE: a condition in which the body's tissues cannot
properly use insulin, leading to blood sugar imbalances.
INTENT-TO-TREAT
ANALYSIS: a method of analyzing the results of a clinical
trial in which all participant who were originally assigned to
an arm are analyzed, including those who dropped out due to
treatment failure or side effects. Contrast with as-treated
analysis.
INTERFERON (IFN): a cytokine (messenger
protein) that plays a role in immune response. The three major
classes of interferon are alpha, beta, and gamma.
INTERFERON-ALPHA: a naturally occurring
protein produced by the immune system that interferes with
viral replication. Interferon-alpha (brand names include
Intron-A, Roferon-A) is standard treatment for HCV and is also
approved for HBV. Side effects may include flu-like symptoms,
fatigue, loss of appetite, depression, and anxiety.
INTERLEUKIN
(IL): a cytokine (chemical messenger), secreted by immune
system blood cells, that regulates a range of immune
functions.
INTERNATIONAL UNIT (IU): a standard unit
of measurement.
INTERNAL RIBOSOME ENTRY SITE INHIBITOR:
an agent that interferes with the translation of viral genetic
material and thus inhibits viral reproduction.
INTOLERANCE: inability
of the body to tolerate a drug, resulting in adverse side
effects.
INTRACELLULAR: within a cell.
INTRAVENOUS
(IV): injected directly into a vein.
INTRAVENOUS
IMMUNOGLOBULIN (IVIG): an antibody preparation administered
intravenously to treat illness in a person whose own immune
system does not produce sufficient antibodies.
INTRON-A: brand
name of interferon-alpha-2b, produced by Schering-Plough.
IN UTERO: in the
uterus; refers to events that occur in the womb before birth.
INVESTIGATIONAL NEW DRUG (IND): an FDA
classification for experimental drugs that are undergoing
clinical trials to assess their safety and effectiveness prior
to marketing approval.
IN VITRO: Latin for "in glass"; refers to
studies done in a test tube or culture medium in the
laboratory.
IN VIVO: Latin for "in a living
organism"; refers to studies done using human or animal
subjects.
IRES INHIBITOR: see internal ribosome
entry site inhibitor.
IRON: an important trace element needed
for the production of hemoglobin in red blood cells. High
levels of iron can be toxic to the liver.
IRON-DEFICIENCY
ANEMIA: the most common type of anemia, caused by a lack of
iron.
ISCHEMIA: reduced blood supply to bodily
tissues.
ISLET CELL: a cell in the Islets of
Langerhans in the pancreas that produces insulin.
IU: see
international unit.
IVDU: see injection drug user.
IVIG: see
intravenous immunoglobulin
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JAUNDICE: (icterus,
itcteric) yellowing of the skin and whites of the eyes due to
high bilirubin levels in the blood. Jaundice is often a sign
of liver damage or gallbladder disease.
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KETONE: a
byproduct of fat metabolism. When the body does not have
enough glucose, the liver converts fatty acids into ketones,
which are used as fuel by the muscles.
KIDNEY
(adjective RENAL): one of two bean-shaped organs located in
the lower back part of the abdominal cavity. The kidneys
filter waste material from the blood and excrete urine.
KIDNEY STONE
(NEPHROLITHIASIS): an accumulation of substances (e.g., drug
crystals, minerals) in the kidneys, leading to blockage and
pain.
KUPFFER CELL: a type of macrophage that
resides in the liver and ingests bacteria absorbed from the
intestines.
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LACTATION: production of breast milk.
LAMIVUDINE (3TC,
brand name EPIVIR): a nucleoside analog drug used to treat
chronic hepatitis B and HIV disease.
LAPAROSCOPIC
LIVER BIOPSY: a type of liver biopsy using a laparoscope.
LAPAROSCOPY: a
procedure in which a lighted instrument is inserted through an
abdominal incision for the purpose of diagnosis, biopsy, or
surgery.
LATENCY (adjective LATENT): the state in
which a disease-causing organism is present in the body, but
not actively replicating or causing illness.
LAXATIVE: an
agent that promotes bowel evacuation (defecation).
LECITHIN: a
fatty compound required for proper metabolism.
LESION: any
abnormal tissue change caused by disease or injury.
LEUKINE: see
granulocyte-macrophage colony-stimulating factor.
LEUKOCYTE: an
immune system white blood cell (e.g, T-cell, B-cell,
neutrophil).
LICHEN PLANUS: an inflammatory disease of
the skin and mucous membranes characterized by red or purple
bumps or blotches. The cause of lichen planus is not known,
but it appears to be an autoimmune condition.
LICORICE ROOT
(GLYCYRRHIZA GLABRA,
GLYCYRRHIZIN,
GAN CAO): an herbal remedy traditionally used to treat
diseases of the liver and bronchial conditions. Glycyrrhizin
is an active component of licorice root.
LIPID: a fat.
LIPODYSTROPHY: a syndrome that involves
abnormal lipid metabolism and redistribution of body fat.
LIPOGENESIS:
production of lipids (fats).
LIVER: a large organ on the upper right
side of the abdomen that plays an important role in the
metabolism of sugars and fats, synthesizes several proteins,
and filters toxins from the blood.
LIVER CANCER:
malignant proliferation of cells in the liver. The most common
type of liver cancer in people with chronic hepatitis is
hepatocellular carcinoma.
LIVER CELL: see hepatocyte.
LIVER ENZYME:
see aminotransferase.
LIVER FUNCTION TESTS (HEPATIC PANEL): a
set of blood tests that measure levels of liver enzymes,
proteins, and various other substances. Liver function tests
are used to help diagnose liver disease, assess the degree of
liver damage and determine how well treatment is working.
LOBE: one of the
four anatomical divisions of the liver; lobes are further
divided into lobules.
LOG: a measure based on the logarithmic
scale that refers to quantities in factor of ten. A log change
is an exponential, or 10-fold, increase or decrease (e.g., a
change from 10 to 100 is a 1-log increase; a change from
1,000,000 to 10,000 is a 2-log decrease). Viral load is
sometimes expressed in logs.
LUPUS: see systemic lupus erythematosus.
LYMPH NODE
(LYMPH GLAND): a small, bean-sized organ located throughout
the body, with concentrations in the neck, groin, and armpits.
Lymph nodes filter out antigens and are the site of immune
cell activation.
LYMPHATIC SYSTEM: a network of organs and
vessels that help maintain the fluid environment of the body
and coordinate immune responses. The lymphoid organs include
the lymph nodes, spleen, thymus, tonsils, and adenoids.
LYMPHOCYTE: a
type of white blood cell (e.g., T-cell, B-cell, natural killer
cell) that plays a role in the body's immune defense.
LYMPHOCYTOPENIA:
a deficiency of lymphocytes.
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MACROPHAGE: a large
scavenger white blood cell that ingests and processes foreign
invaders and cellular debris. Specialized macrophages protect
the skin, lungs (alveolar macrophages), brain (microglia),
liver (Kupffer cells), and other tissues.
MAGNETIC
RESONANCE IMAGING (MRI): a sensitive, non-invasive method for
viewing soft tissues of the body using a magnetic field.
MAINTENANCE
THERAPY: therapy that follows successful initial treatment of
an illness; generally maintenance therapy continues for a long
period of time (possibly for life) to prevent disease
recurrence. Contrast with induction therapy.
MAJOR
HISTOCOMPATIBILITY COMPLEX (MHC): a group of genes that
controls the expression of cell surface protein markers (also
known as human leukocyte antigen, or HLA, markers) that allow
immune cells to recognize the body's own cells (that is, to
distinguish "self" from "non-self").
MALAISE: a
generalized feeling of illness and discomfort; a flu-like
feeling.
MALIGNANCY: a cancer, neoplasm, or tumor
that grows in an uncontrolled manner, and may invade nearby
tissue and metastasize, or spread, to other areas of the body.
MALIGNANT: a
condition that is severe, harmful, or resistant to treatment.
Contrast with benign.
MALNUTRITION: lack of the minimum amount
of nutrients (proteins, carbohydrates, lipids, vitamins,
minerals, etc.) necessary for good health. Malnutrition may
result from poor diet, lack of appetite, or inadequate
absorption of nutrients from the gastrointestinal tract.
MAXIMINE: see
histamine dihydrochloride.
MEAN (AVERAGE): a statistical measurement
of the central tendency, or average, of a set of values. For
example, in the series of values "1, 1, 3, 5, 6, 8, 8, 10,
21," the mean is 7 (determined by adding up all the values and
dividing by the number of values). Contrast with median.
MEDIAN: the
number within a series that is preceded and followed by an
equal number of values. For example, in the series of values
"1, 1, 3, 5, 6, 8, 8, 10, 21," the median is 6 (there are four
values lower and four values higher). Contrast with mean.
MEDITATION: a
technique for relaxation and clearing and focusing the mind.
MEGAKARYOCYTE: a large precursor blood
cell that gives rise to platelets.
MEMBRANE: a thin sheet or layer of tissue
that serves as a semi-permeable covering.
MEMBRANOPROLIFERATIVE GLOMERULONEPHRITIS:
see glomerulonephritis.
MENOPAUSE: the cessation of menstruation.
MENSTRUATION: a stage of the female
reproductive cycle. An ovum (egg) matures and is released
every month. Hormones prepare the uterus for possible
implantation. If pregnancy does not occur, the uterine lining
(blood and tissue) is shed and expelled (the menstrual
period).
MESSENGER RNA (mRNA): a piece of
ribonucleic acid that carries genetic information from DNA to
ribosomes in order to synthesize new proteins.
METABOLISM
(adjective METABOLIC): the processes of building the body's
molecular structures from nutrients (anabolism) and breaking
them down for energy (catabolism). Also, the chemical
processing or breakdown of food, drugs, and toxins.
METASTASIS
(adjective METASTATIC, verb
METASTASIZE): a disease (especially
cancer) that spreads from one part of the body to another.
METHADONE: an
oral opiate-like drug used for pain management and to treat
opiate (e.g., heroin) addiction. Methadone maintenance therapy
prevents withdrawal symptoms by administering small doses of
the drug on a regular basis.
METHIONINE: see s-adenosylmethionine.
MILK THISTLE
(SILYBUM MARIANUM, SILYMARIN): the most widely used herbal
remedy to treat chronic hepatitis. Silymarin is a combination
of active components derived from milk thistle. Studies
suggest that milk thistle can reduce hepatitis symptoms and
helps prevent liver damage.
MINERAL: an inorganic element that
promotes chemical reactions within the body and is necessary
for proper cellular metabolism. Essential minerals include
calcium, iodine, iron, magnesium, potassium, and zinc.
MISCARRIAGE: a
pregnancy that ends prematurely and is not carried to term.
MITOCHONDRION (plural MITOCHONDRIA): a
rod-shaped organelle in the cytoplasm of a cell that produces
energy.
MHC:
see major histocompatibility complex.
MOLECULE: a
small unit of matter made up of atoms. A molecule is the
smallest unit of a substance that retains its unique
characteristics.
MONOCLONAL ANTIBODIES: a preparation
consisting of identical antibodies active against a specific
pathogen.
MONOCYTE: a large white blood cell that
plays a role in immune defense. Monocytes circulate in the
bloodstream; when they migrate to the tissues, they mature
into macrophages.
MONOGAMY (MONOGAMOUS): having a single
spouse; more often used to refer to having a single sexual
partner.
MONOTHERAPY: use of a single drug for
treatment. Monotherapy for HCV (interferon alone) is no longer
considered standard treatment. Contrast with combination
therapy.
MORBIDITY: sickness; the state of being
affected by disease.
MORTALITY (also MORTALITY RATE): death.
The mortality rate is the rate of death in a given population.
MOXA: the
herb mugwort.
MOXIBUSTION: in traditional Chinese
medicine, the burning of an herb (moxa) to generate heat and
stimulate the flow of qi.
MRI: see magnetic resonance imaging.
mRNA: see
messenger RNA.
MU: abbreviation for million units.
MUCOUS MEMBRANE
(MUCOSA): a moist layer of semi-permeable tissue lining the
openings of the body (e.g., the gastrointestinal, respiratory,
and genitourinary tracts).
MULTIFOCAL: occurring at more that one
site.
MULTIVARIATE ANALYSIS: a statistical
analysis that takes into account several different factors or
variables.
MULTIVITAMIN: a nutritional supplement
that contains several different essential vitamins and
minerals.
MUTATION (verb MUTATE): a change in the
character of a gene that is perpetuated when a cell divides or
a virus replicates.
MYALGIA: muscle pain.
MYELIN: a white
fatty substance that forms a sheath around the axons of
neurons (nerve cells) and provides the insulation necessary
for the proper transmission of electrical impulses.
MYELOSUPPRESSION: inhibition of the bone
marrow, resulting in decreased blood cell production.
MYELOTOXIC:
poisonous to or destructive of the bone marrow.
MYOCARDIAL
INFARCTION: blockage of the arteries serving the heart, often
leading to angina pectoris and/or heart attack.
MYOPATHY: muscle
inflammation, damage, or disease.
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top
NAC: see
n-acetyl-cysteine.
N-ACETYL-CYSTEINE (NAC): a form of the
animo acid cysteine that is available as a nutritional
supplement. NAC is used to prevent liver damage due to
acetaminophen overdose.
NAIVE: inexperienced. Often used to
describe an individual who has never taken a certain drug, or
to an undifferentiated immune system cell.
NARCOTIC: see
opiate.
NATIONAL INSTITUTES OF HEALTH (NIH): a
large biomedical research organization that is part of the
U.S. Public Health Service. The NIH includes several
institutes, centers, and divisions. The National Institute of
Allergy and Infectious Diseases (NIAID) and the National
Institute of Diabetes and Digestive and Kidney Diseases
(NIDDK) conduct research on viral hepatitis.
NATURAL KILLER
(NK) CELL: a type of white blood cell that attacks and kills
tumor cells and cells infected with microorganisms.
NATUROPATHY: a
system of natural healing based on the philosophy that the
body has the ability to cure itself.
NAUSEA: stomach
distress characterized by an aversion to food and an urge to
vomit.
NDA:
see new drug application.
NECROSIS: cell or tissue death.
NECROINFLAMMATION: tissue inflammation
and death.
NEONATE (adjective NEONATAL): a newborn,
especially within the first days or weeks after birth.
NEOPLASM
(NEOPLASIA): a tumor or growth; tissue that develops
abnormally or cells that proliferate more rapidly than normal.
A benign neoplasm (e.g., a wart) is localized and does not
spread to other tissues; a malignant neoplasm (cancer) can
spread to other parts of the body.
NEPHROLITHIASIS:
see kidney stone.
NEPHROTOXICITY: the property of being
poisonous or harmful to the kidneys.
NEUPOGEN: see
granulocyte colony-stimulating factor.
NEURALGIA: nerve
pain.
NEUROPATHY (adjective NEUROPATHIC): nerve
damage or disease.
NEUTROPENIA: an abnormally low number of
neutrophils, resulting in increased susceptibility to
infection.
NEUTROPHIL: the most common type of
immune system white blood cell. Neutrophils are phagocytes
that engulf and destroy invading organisms such as bacteria
and fungi.
NEW DRUG APPLICATION (NDA): an
application made by a drug manufacturer to the FDA to request
marketing approval for a new drug.
NIACIN: see
vitamin B.
NIAID: National Institute of Allergy and
Infectious Diseases. See National Institutes of Health.
NIDDK: National
Institute of Diabetes and Digestive and Kidney Diseases. See
National Institutes of Health.
NIH: see National Institutes of Health.
NK CELL: see
natural killer cell.
NON-A/NON-B HEPATITIS: see hepatitis C.
NON-NUCLEOSIDE REVERSE
TRANSCRIPTASEINHIBITOR (NNRTI): an antiviral drug that
suppresses viral replication by interfering with the action of
the reverse transcriptase enzyme.
NONOXYNOL-9: a chemical formerly used as
a spermicide and microbicide. Recent studies have shown that
nonoxynol-9 causes tissue damage and may increase the risk of
STD transmission.
NONRESPONDER: person
who does not show improvement while undergoing treatment. In
HCV, a nonresponder does not achieve normal ALT levels or an
undetectable viral load.
NONSTEROIDAL
ANTI-INFLAMMATORY DRUG (NSAID): a drug (e.g., aspirin,
acetaminophen, ibuprofen) that relieves pain and reduces
inflammation by blocking the body's production of
prostaglandins.
NNRTI: see
non-nucleoside reverse transcriptase inhibitor.
NRTI: see nucleoside
reverse transcriptase inhibitor.
NSAID: see
nonsteroidal anti-inflammatory drug.
NUCLEOSIDE ANALOG: see
nucleoside reverse transcriptase inhibitor.
NUCLEOSIDE REVERSE
TRANSCRIPTASE INHIBITOR (NRTI, NUCLEOSIDE ANALOG): a drug that
mimics a nucleoside, one of the building blocks of genetic
material (DNA or RNA). NRTIs suppress viral replication by
interfering with the action of the reverse transcriptase
enzyme, causing premature termination of new chains of genetic
material.
NUCLEOTIDE: a genetic
building block.
NUTRIENT: an agent
that promotes proper growth and metabolism.
NUTRITION: the process
by which living organisms digest and metabolize food to use
for maintenance and growth of tissues.
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OFF-LABEL: use of an
FDA-approved drug for an indication other than that for which
it was approved.
ONCOGEN: an agent that
promotes neoplastic cell growth, or cancer.
ONCOGENESIS: the
development and growth of cancer.
ONCOLOGY: the study
and treatment of cancer.
OPEN-LABEL: a drug
trial which is not randomized and not blinded; both
participants and investigators know what drug is being tested
and what dosages are being used.
OPIATE (NARCOTIC): a
class of drugs (e.g., heroin, codeine, methadone) that are
derived from the opium poppy or produced synthetically and
have opium-like effects. Opiate drugs relieve pain, dull the
senses, and induce sleep.
OPPORTUNISTIC ILLNESS
(OPPORTUNISTIC INFECTION, OI): an illness or infection that
does not normally occur in a person with a healthy immune
system, but affects immunocompromised persons.
ORAL: relating to the
mouth; taken by mouth.
ORGANIC FOOD: food
that is grown naturally without the use of chemical
fertilizers, pesticides, or other artificial intervention.
OSTEOARTHRITIS:
degenerative joint disease.
OTC: see
over-the-counter.
OVER-THE-COUNTER
(OTC): drugs that are available without a prescription.
OXIDATIVE STRESS:
increased levels of free radicals in the body, potentially
leading to cell damage and death.
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PALLIATIVE: offering
symptomatic relief and comfort care (e.g., alleviation of
pain) rather than a cure.
PALLOR: paleness.
PANCREAS: a digestive
gland in the abdominal cavity that secretes digestive enzymes.
PANCREATITIS:
inflammation of the pancreas.
PANCYTOPENIA: an
abnormally low level of all types of blood cells, typically
due to bone marrow damage.
PARENTERAL: nutrients
given by injection into a vein, bypassing the gastrointestinal
tract.
PATHOGEN (adjective
PATHOGENIC): any disease-causing agent, especially a
microorganism (bacteria, virus, fungus, parasite).
PATHOGENESIS: the
development and progression of a disease.
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