Subject: GLOSSARY, complete (a-z)
Date: November 1989 (149 items) (590 lines)
Originally compiled by Etienne Hafs from BETA #3 and BETA #4, with additions by sysop.

ACTG:
AIDS Clinical Trials
acute:
Rapid in onset; severe, life-threatening; the opposite of persistent or long-term.
acyclovir (zovirax):
An antiviral drug used in the treatment of herpes simplex virus 1 (HSV 1), herpes simplex virus 2 (HSV 2) and herpes zoster.
aerosolized:
Administered as a fine spray and inhaled.
AIDS:
Acquired Immune Deficiency Syndrome.
alveolar sac:
The smallest end unit of the lung where oxygenation of the blood occurs and where carbon dioxide is removed from the blood to be exhaled. Each sac is about .25 mm in size and there are approximately 1.5 million in each lung.
AmFAR:
The American Foundation for AIDS Research.
anemia:
An abnormally low number of red blood cells.
anergy:
Lack of response to the injection of a certain foreign substance. This may indicate the inability of the immune system to mount a normal allergic response.
anorexia:
Prolonged loss of appetite that leads to significant weight loss.
antagonist:
A drug that prevents or reverses the action of another drug.
antibiotic:
A natural of synthetic substance that inhibits growth of or destroys microorganisms, typically bacteria.
antibody:
A protein substance, developed in response to an antigen, that destroys or neutralizes bacteria, viruses or other harmful toxins. This antigen/antibody reaction forms the basis of immunity (see also p24 antigen and autoimmune response).
antigen:
A substance that stimulates an immune response. The immune system recognizes these substances as being foreign, and produces antibodies to "fight" them. This antigen/antibody response is an important part of immunity.
antigenemia:
The presence of detectable amounts of antigens in the blood.
ARC:
AIDS-related complex.
aspergillosis:
A fungal infection of the lung which can spread through the blood to other organs. Symptoms include fever, chills, difficulty breathing, and coughing up blood. If the infection reaches the brain, it may cause dementia.
assay:
A test to detect the presence and concentration of a drug or substance in the blood, other body fluids, or body tissues.
asymptomatic seropositive:
An individual who has been infected with HIV but shows no apparent symptoms. HIV positive individuals can still spread the disease even though they are asymptomatic.
atrophy:
A wasting or decrease in size.
autoimmune response:
A response caused by the immune system mistakenly attacking the body's own tissues.
axon:
A long structure in the nerve cell that acts as a pathway for nerve impulses.
AZT:
Dihydro methyl pyridinyl carbonyl azido dideoxythymidine.
baseline:
A known value with which later measurements can be compared (e.g., baseline temperature, baseline hemoglobin level.)
bioavailability:
The rate and extent to which a substance is absorbed and circulated within the body.
blood-cerebrospinal fluid barrier:
A barrier between the blood and the fluid surrounding the brain and spinal column. It only allows some substances to pass from the blood to the fluid. This barrier presents a potential problem in treating HIV infection because treatments must cross it to stop HIV infection in the brain.
bone marrow cell pool:
Those bone marrow cells responsible for the production of blood cells.
bronchodilating:
Anything that opens or expands the bronchi (that part of the body that conveys air to and from the lungs). Bronchodilating drugs can reduce coughing, wheezing, and shortness of breath.
cachexia:
Profound and marked state of general ill health and malnutrition.
candidiasis:
A fungal infection, usually of the moist cutaneous areas of the body, including the skin, mouth, esophagus (candida esophagitis) and respiratory tract.
CDC:
The Centers for Disease Control.
CD4:
A protein embedded in the cell surface of T helper cells and certain other cells. HIV invades these cells by first attaching to the CD4 receptor. This term also refers to an experimental, genetically engineered drug that acts as a "decoy" that "tricks" HIV into attaching to it instead of infecting new cells.
central nervous system:
The brain and spinal cord with their nerves and end organs that control voluntary acts.
chromosomes:
A threadlike structure in the nucleus of a cell that contains genetic information encoded by DNA.
clinical:
Based on observation of the condition of patients and their symptoms, as opposed to blood work or other laboratory tests.
coma:
A state of unconsciousness in which movement and mental processes are impaired. People in deep coma cannot be aroused by external stimulus.
compassionate use:
A program in which people who are seriously ill can have their physicians request access to an experimental drug from the manfacturer. Very few drugs are available through this program.
cortex:
The external part of an organ, such as the brain, kidney, or adrenal gland.
corticosteroid:
Any of a number of steroid substances obtained from the cortex of the adrenal gland, or any synthetic substitute. Corticosteroids are immunosuppressive and HIV infected individuals should be cautious about taking them.
cranial nerves:
Twelve pair of nerves in the brain.
creatine phosphokinase (CPK):
An enzyme essential to muscle contraction that is abnormally elevated in the blood in certain conditions.
cryptococcal meningitis:
A fungal infection that affects the three membranes (meninges) surrounding the brain and spinal cord. Symptoms include severe headache, vertigo, nausea, anorexia, sight disorders and mental deterioration.
cryptosporidiosis; cryptosporidial diarrhea:
Caused by a parasite and characterized by chronic, profuse, watery diarrhea, accompanied by a fever, marked weight loss and enlarged lymph nodes.
cytokines:
Naturally occurring proteins that regulate or modify the growth of specific cells.
cytomegalovirus (CMV):
a herpes virus. An opportunistic infection that can cause blindness and be fatal in AIDS patients. ("Sight-threatening" refers to the later stage of CMV that is considered to be an immediate threat to a patient's vision. "Peripheral CMV retinitis" refers to the early stages of the disease, which can become sight-threatening if left untreated.)
danazol:
A drug that suppresses the action of the pituitary gland. It is used in the treatment of thrombocytopenia (ITP).
dapsone:
An antibacterial drug used to treat PCP.
dementia:
A loss of mental capacity. AIDS related dementia may be caused by HIV or other infections.
demyelinating:
Having to do with destruction of the myelin sheath that surrounds and insulates the axon of some nerves.
distal:
Farthest from the center or from a central point of reference.
DNA:
Deoxyribonucleic acid. Material in the nucleus of a cell which contains the cell's genetic code.
double blind study:
A method of medical investigation in which neither the subject nor the investigator knows what treatment, if any, the subject is receiving. At the end of the experiment, the "code" is broken and data are analyzed with respect to the various treatments used. This method attempts to eliminate observer and subject bias.
efficacy:
Strength, efficiency. The ability to achieve a desired effect.
enzyme:
A protein that can produce chemical changes in other substances without being changed itself.
FDA:
Food and Drug Administration.
G6PD:
Glucose-6-phosphate dehydrogenase.
ganciclovir (DHPG):
An experimental antiviral drug used in the treatment of CMV retinitis, AIDS related meningoencephalitis, and AIDS related polyradiculopathy.
granulocyte:
A type of white blood cell.
granulocytopenia:
An abnormally low number of granulocytes in the circulating blood that can lead to increased risk of severe bacterial infection.
Guillain Barr syndrome:
An acute disease that produces bilateral weakness or paralysis, most commonly in the legs and feet.
hairy leukoplakia:
A condition believed to be caused by a combination of the Epstein-Barr and human papilloma viruses. Symptoms include white patches in the mouth, often in a striped pattern on the side of the tongue. It is believed to be found only in people who are HIV-positive.
half-life:
The time required for half the amount of a drug to be eliminated from the body.
hematocrit:
The volume percentage of red blood cells in whole blood. In men, it normally constitutes about 40 to 54% of the whole blood; in women, it normally constitutes about 37 to 47%.
hemoglobin:
The protein in red blood cells that carries oxygen to the cells. Normal hemoglobin values for women are 12 grams per liter and 14 16 grams per liter for men. These values may vary according to where the test is performed.
herpes simplex virus 1 (HSV 1):
A virus that can cause painful "cold" sores or blisters on the lips ("fever blisters") or in the mouth or around the eyes. The symptomatic disease stage occurs at unpredictable intervals of weeks, months or years. The latent (inactive) virus can reactivate due to emotional stress, physical trauma, other infections, or suppression of the immune system. HSV 1 responds well to treatment with acyclovir.
herpes simplex virus 2 (HSV 2):
A virus that can cause an inflammatory disease of the skin or mucous membrane. It is highly contagious and is usually sexually transmitted. Painful blisters may appear on the anus or genitals 2 12 days after infection. In healthy individuals, symptoms resolve without treatment in 2 3 weeks. In severely immuno-compromised individuals, the virus is sometimes difficult to suppress. Like HSV 1, HSV 2 may lie dormant (inactive) for weeks, months or years before reactivating to produce symptoms. Treatment with acyclovir usually works well.
herpes varicella zoster virus (HVZ):
May appear in adulthood as a result of having had chicken pox (caused by the varicella virus) as a child. Herpes zoster, also called shingles, consists of very painful blisters on the skin and follows nerve pathways.
herpes virus 6 (HHV 6):
A new herpes virus recently discovered by Dr. Robert Gallo and associates at the National Cancer Institute. Dr. Gallo has suggested that HHV 6 may play an important co-factor role in the development of AIDS.
herpes zoster:
A condition characterized by painful blisters which generally dry and scab, leaving minor scarring. Also known as "shingles," it is caused by reactivation of a previous infection from varicella-zoster, the virus that causes chicken pox.
histoplasmosis:
A disease caused by a fungal infection that can affect all the organs of the body. Symptoms usually include fever, shortness of breath, cough, weight loss and physical exhaustion.
HIV positive:
Presence of antibodies to the human immunodeficiency virus, the virus that is assumed to cause AIDS, in the blood.
IDU:
Injection drug user(s).
immunoglobulin:
One of a family of closely related proteins that can act as antibodies.
immunomodulating:
A therapy that attempts to reconstruct or enhance a damaged immune system.
IM:
Intramuscular.
IND status:
Investigational new drug status. Certain drugs are available on a case by case basis through this mechanism.
intravenous:
Within or into the veins. Intravenous drugs are injected directly into the veins.
isolate:
Different strains of HIV.
ITP:
Idiopathic thrombocytopenia. Idiopathic means that the disorder is of unknown origin. (See also thrombocytopenia).
IV:
Intravenous. Generally used to indicate the reception of liquids through a tube connected to a vein in the patient, or to the reception of liquids directly from a hypodermic needle.
jaundice:
Yellow pigmentation of the skin and whites of the eyes caused by liver disease (such as hepatitis) or excessive destruction of red blood cells.
Kaposi's sarcoma (KS):
A tumor of the walls of lymph vessels. It usually appears as pink to purple painless spots on the surface of the skin, but it can also occur internally. KS is one of the major cancers found among PWA, especially gay and bisexual men.
Karnofski score:
A measure given by a physician to a patient's ability to perform certain ordinary tasks.
kg (kilogram):
A measure of weight equal to 2.2046 pounds.
lactic dehydrogenase (LDH):
An enzyme in the blood and various tissues that helps to break down the lactic acid in milk and certain other foods. An elevated level of LDH may signal damage to muscle or other tissues.
leucovorin calcium:
A calcium salt of folic acid (a member of the vitamin B complex). Leucovorin is used to treat severe anemias. The effectiveness of leucovorin calcium as a supplement to TMP-SMX is not well understood, but it has been shown to reduce drug toxicity in other antibiotic treatment.
leukocyte:
White blood cells that can move from the bloodstream to tissue and back again. They act as scavengers, helping to combat infection.
leukopenia:
An abnormally low normal number of white blood cells in the circulating blood.
lymphadenopathy:
Enlargement of the lymph nodes or lymph system.
lymphocyte:
A type of white blood cell.
lymphokines:
Substances that help to produce cellular immunity by stimulating macrophages and lymphocytes.
MAI:
See Myobacterium avium intercellulare.
macrophage:
A large cell which ingests degenerated cells and blood tissue, and foreign particles. It breaks down foreign particles and displays their antigens on its surface. T cells then read these antigens, beginning the process of antibody production. Macrophages exist in large numbers throughout the body.
meningoencephalitis:
Inflammation of the brain and of the membranes covering the brain and spinal cord.
metastatic:
Having to do with the transfer of a disease from one part of the body to another.
mitogen:
A substance that induces the division of cells and can induce cancer-like effects.
nanomole:
One billionth (10 -9 power) of a mole (molecular weight).
neurologic (neurological):
Concerning the central nervous system (brain and spinal cord) or the peripheral nervous system (the rest of the nervous system) and/or diseases of these systems.
neuropathy:
Any disease of the nervous system.
neuroradiological:
Pertaining to the study of the nervous system with X rays.
neutropenia:
A shortage of neutrophils, the most common type of white blood cells.
neutrophil:
The most common type of white blood cell. They are the immune system's primary defense against bacterial infections. The normal range for neutrophils is from 3000 to 7000.
NIAID:
The National Institute of Allergy and Infectious Diseases.
NIH:
National Institutes of Health.
Orphan drug:
An FDA term for classification of a drug. Indicated for rare diseases. Gives the exclusive right to produce a drug that will be used by only an estimated small number of patients.
p24 antigen:
A protein fragment of HIV. The p24 antigen test measures this fragment. A positive result for p24 antigen suggests active HIV replication. A positive test result may mean the individual has a higher chance of developing AIDS in the future.
pancreatitis:
Inflammation of the pancreas. Characterized by intense abdominal pain, nausea, vomiting, constipation, slow pulse, and possible jaundice.
parallel track:
A proposed system that expands access to a promising drug to people who cannot participate in clinical trials of that drug (at the same time as the clinical trials are underway).
paraplegia:
Paralysis of both legs and lower part of the body.
passive immunotherapy:
A treatment for HIV infection which uses p24 antibody-rich plasma that has been centrifuged to separate it from the blood of asymptomatic HIV-positive people.
pathogen:
Any microorganism capable of causing disease.
PCP (Pneumocystis Carinii Pneumonia):
A type of lung infection found in immunosuppressed individuals. It is the most common opportunistic infection in AIDS.
peripheral:
Located at, or pertaining to, the periphery; occurring away from the center.
peripheral neuropathy:
A disorder of the nerves, usually involving the feet or hands, and sometimes the legs and arms. Symptoms may include numbness, a tingling or burning sensation, sharp pain, weakness, and abnormal reflexes. In severe cases, paralysis may result.
PGL:
Persistent generalized abnormal enlargement of the lymph nodes (lymphadenopathy).
pharmacokinetic:
Concerning the study of how a drug passes through the body, the extent and rate of absorption from the stomach, its distribution, and location in tissues.
Phase I:
The first step in human testing of a drug. Tests for safety in humans, and is usually done with a very small number of participants.
Phase II:
Effectiveness testing in humans, done if Phase I has been completed and shows acceptable levels of safety. Usually done with 50 to 300 individuals.
Phase III:
Expansion of Phase II testing to 300 to 3000 volunteers. Compares drug to other methods and confirms results of Phase II with statistically more reliable numbers.
placebo:
An inert, inactive substance. In placebo-controlled drug studies, a placebo is given to one group of patients, while the drug being tested is given to another group. The results obtained in the two groups are then compared.
plasma:
A fluid in which blood cells and nutritive substances are circulated in the body. It also serves to remove waste products of metabolism from organs and to facilitate chemical communication between different portions of the body.
plasmapheresis:
The selective removal of certain proteins or antibodies. This process is sometimes used in the treatment of some peripheral neuropathies.
platelet:
A type of blood cell that facilitates blood clotting.
polyneuropathy:
A disease in which several peripheral nerves are affected at the same time.
prednisone:
A synthetic corticosteroid sometimes used in the treatment of neuropathies. Like all corticosteroids, it is immunosuppressive.
Project Inform:
A San-Francisco-based organization which disseminates information about HIV public policy issues and treatments for HIV infection.
prophylaxis:
Treatment that helps to prevent a disease before it occurs or recurs.
protein:
A group of compounds which occurs naturally in plants and animals and other organisms. Proteins provide the structures essential for the growth and repair of animal tissue.
protocol:
The blueprint of a scientific experiment and the methods used in that experiment. Defines length of experiment, dosage levels, criteria for participation, statistical analysis, etc.
PWA or PLWA:
Person living with AIDS or people living with AIDS.
PWARC or PLWARC:
Person living with ARC (AIDS-related conditions) or people living with ARC.
seropositive:
Infected with HIV, or a person infected with HIV.
shingles:
herpes zoster (usually blisters around waist)
stupor:
A state of semi-consciousness.
sulfadiazine:
A sulfa drug used in the treatment of K.S., toxoplasmosis and meningitis.
symmetric:
Occurring in the same parts on opposite sides of the body (e.g., right leg and left leg).
synergism, synergistic:
The harmonious action of two or more drugs producing a greater effect than with either drug alone.
systemic:
Affecting the whole body.
T-helper cell:
A type of white blood cell (also known as T4 cells) which help the body fight off certain infections. HIV invades these cells and weakens or destroys them. Regular monitoring of T-helper cell counts in HIV-infected individuals helps provide an idea of the progression of HIV infection. The "normal" range for T-helper cells in people who are HIV-negative is 480-1800, but this may vary, depending on the laboratory where the test is given. The lower the T-helper cell count, the greater the risk for opportunistic infections.
thrombocytopenia:
An abnormally low number of platelets in the blood.
toxicology:
The study of the harmful effects of substances on the body. The science of toxicology determines the level of toxicity of substances, how toxicity occurs, and how it can be controlled.
toxoplasmic encephalitis:
An inflammation of the brain caused by toxoplasmosis, a parasite.
toxoplasmosis:
A disease due to infection with the protozoa toxoplasmosa gondii, frequently causing focal encephalitis (inflammation of the brain). It may also involve the heart, lung, adrenal glands, pancreas and testes.
Treatment IND:
Treatment Investigational New Drug. An FDA classification that allows U.S. physicians to prescribe a promising drug before it has been approved for marketing.
uncontrolled trials:
Research studies in which there are no participants taking a placebo (see also placebo controlled study).
uric acid:
A substance found in the blood and urine that is a product of protein digestion.
vincristine:
A drug sometimes used in the treatment of K.S., ITP (thrombocytopenia), leukemias, lymphomas, and solid tumors.
white matter:
Referring to a specific portion of the brain. The brain also contains gray matter.
zoster, herpes:
shingles (usually blisters around waist)