A Complied Glossary of AIDS Terms, and Terminology

Derived from texts obtained by: Tall Paul Updated by: Norman R. Brown

(December 22, 1991)

Glossary of AIDS Terminology

566C80: A treatment possibility for PCP and toxoplasmosis, currently under study. Developed by Burroughs-Wellcome, 566C80 shows promise of actually killing pneumocystis, rather than merely controlling its growth (as with pentamidine).

ABCD: Liposome-encapsulated Amphotericin B made by Liposome Technology, Inc. Currently in Phase I testing for PCP prophylaxis.

ABLC: Amphotericin B lipid complex made by Liposome Technology, Inc. Currently in Phase II testing for cryptococcal meningitis.

ABDOMINAL: Pertaining to the abdomen, the area of the body between the thorax and pelvis (also called the belly).

ABSOLUTE CD4+ CELL COUNT (T4 COUNT): The actual number of T helper cells (lymphocytes) in a cubic millimeter of blood. The CD4+ count is significantly lower in HIV+ persons.

ACANTHAMOEBIASIS: Infection with Acanthamoeba castellani, a free-living amoeba which ordinarily inhabits moist soil or water. This opportunistic parasite causes one type of meningoencephalitis. (O.I.).

ACCRUAL: The process of signing people up to participate in drug trials.

ACEBUTOLOL: A beta-blocker commonly used in the treatment of hypertension (high blood pressure, angine pectoris, and certain types of arrythmia (irregular heartbeat).

ACETYLCHOLINE: A chemical found in the body and brain that is felt to be important as a neurotransmitter. It appears to counteract many actions of dopamine.

ACID-LABILE ALPHA INTERFERON: A subclass of alpha interferon which is destroyed by acid. It has been shown to be produced at high levels by white blood cells which are infected with HIV. It has been implicated as a predictor of AIDS and is associated with a greater likelihood of developing opportunistic infections.

ACID-STABLE ALPHA INTERFERON: Alpha interferon which remains stable in acid. It has been reproduced in large quantities through DNA technology and is used as a treatment for Kaposi's Sarcoma. It is also being investigated as an antiviral treatment for HIV infection.

ACQUIRED: A condition that is not inherited or congenital.

ACQUIRED IMMUNE DEFICIENCY SYNDROME (AIDS): AIDS is believed to be caused by a member of the retrovirus group called HIV (human immunodeficiency virus), of which there are a number of variants that also may cause AIDS. HIV attacks and destroys helper T-lymphocytes, which have a vital role in the defense against virus and fungus infections and some cancers. Once inside cells, HIV takes over the cell function and starts to reproduce (replicate), in time, producing hundreds of cloned copies of itself which in turn attack other cells continuing the process of replication. AIDS is characterized by this defect in the body's natural immunity against disease. People who have AIDS do not die from the disease per se, but from a number of serious, often fatal secondary or "opportunistic infections" and malignancies. The incubation period (the period between initial infection and the development of the disease findings or symptoms) is from three to ten years or more. The AIDS virus does not attack only the immune system. It is known to have a definite affinity for brain tissue. Increasing numbers of cases of HIV encephalopathy (brain involvement) are now occurring. This condition leads to a slow progressive dementia with eventual death. Treatment has to be considered from points of view--the treatment of the disorders resulting from the immune deficiency and the attack on the causal virus infection. Another approach is to try to improve the efficiency of the immune system itself. AIDS is a manifestation of infection with HIV characterized by the presence of one or more diseases as defined by the Center for Disease Control (CDC). These diseases occur following a depression of an individual's immune system function. The affected person becomes susceptible to unusual infections and/or malignancies (O. I.).

ACROMEGALY: A chronic disease caused by hypersecretion of the pituitary growth hormone and characterized by enlargement of many parts of the skeleton, especially the nose, ears, jaws, fingers, and toes.

ACTG: See AIDS Clinical Trials Group

ACTH (ADRENOCORTICOTROPHIC HORMONE): The pituitary hormone that regulates cortisol production.

ACTH STIMULATION TEST: A test to assess the functioning of the adrenal cortex, the part of the adrenal gland that makes cortisol.

ACTIVE IMMUNITY: Immunity produced by the body in response to stimulation by a disease-causing organism or other antibody.

ACUPUNCTURE: Therapy in which needles are applied to meridians (set points of the body). The precise disorder treated or the degree of anesthesia required determines the temperature of the needle used, the angle of insertion, the speed of insertion and withdrawal.

ACUTE: Rapid in onset; severe, life-threatening. The opposite of persistent, chronic, or long-term.

ACYCLOVIR (ACV) (trade name ZOVIRAX): A prescription and antiviral drug used to treat herpes simplex. Some studies suggest when given with AZT may increase the anti-HIV benefit of AZT.

ADDICTION: Physiological and psychological dependence on and craving for a chemical substance.

ADENOCARCINOMA: Technical name for a malignant tumor derived from a gland or glandular tissue, or a tumor of which the gland-derived cells form gland-like structures. Examples include most cancers of the colon, breast, pancreas, and kidney and many other organs.

ADENOPATHY: Enlargement of glands; especially the lymph nodes.

ADENOVIRUS: A group of DNA-containing viruses originally identified in human adenoid tissue present in latent infections in healthy persons that can cause upper respiratory tract infection and conjunctivitis as opportunistic infections in PWAs. (O.I.)

ADJUNCT: Any substance which is taken in conjunction with, and used as a secondary treatment, to a main treatment.

ADJUVANT: Any substance which enhances the immune-stimulating properties of an antigen or the pharmacological effect of a drug.

ADMINISTRATION: (or route of administration). This term refers to how a drug of therapy is introduced into the body (e.g. intravenously, orally).

ADVERSE REACTION: Patients in trials may have toxic reactions to the experimental medicines. Toxic reactions are usually listed in the protocol and the patient's Informed Consent. However, some reactions may never have been reported before. Any amount of toxicity must be reported within 24 hours by telephone to the sponsor of the trial, who then must tell the FDA. A clinical trial can be stopped because of adverse reaction.

AEROSOLIZED: A form of administration in which a drug, such as pentamidine, is turned into a fine spray or mist by a nebulizer, and inhaled.

AEROSOLIZED PENTAMIDINE (trade names NEBUPENT and PNEUMOPENT): A prescription drug that has antiprotozoal activity. The drug is delivered by an aerosol producing device (nebulizer) and is inhaled by mouth and used as a prophylaxis for Pneumocystis carinii pneumonia (PCP) in AIDS patients and others with T4 cell counts of 200 and below.

AFB: Acid Fast Bacilli

AGAMMAGLOBULINEMIA: A near total absence of immunoglobulin, or antibodies.

AGENT: Any substance or force capable of bringing about a biological, chemical, or physical change. An agent can also be a person acting on behalf of someone else.

AGONIST: A chemical or drug that enhances neurotransmitter activity. There are two important types of agonists: Indirect agonists act to increase the release of the neurotransmitter or to delay its breakdown. Amantadine (Symmetrel) is an example of an indirect agonist. Direct-acting agonists (bromocriptine, pergolide, lisuride) directly stimulate dopamine receptors and have been used mainly as an ancillary drug for parkinson patients who are helped with moderate doses. Pergolide and lisuride remain investigational drugs, available only at research institutions.

AIDS CLINICAL DRUG DEVELOPMENT COMMITTEE (ACDDC): A committee of mostly academic and government physicians who review candidate drugs submitted by researchers and drug companies. From available data, they assign a research priority; low, medium, or high.

AIDS CLINICAL TESTING UNIT (ACTU): The sites where NIAID's AIDS drug clinical trials are performed.

AIDS CLINICAL TRIALS GROUP (ACTG): Sponsored by the National Institute of Allergy and Infectious Disease, there are numerous medical centers participating in the evaluation of treatments for HIV-related infections.

AIDS RELATED COMPLEX (ARC): A term not officially defined or recognized by the CDC which has been used to describe a variety of symptoms and signs found in some persons infected with HIV. These may include recurrent fevers, unexplained weight loss, swollen lymph nodes, and/or fungus infection of the throat and mouth. Also commonly described as symptomatic HIV infection.

AL-721: A drug from the Ethigen Corp. Was studied as an anti-retroviral, but no clinical or laboratory evidence of benefit has been observed.

ALKALINE PHOSPHATASE (ALK PHOS): An enzyme measurement that indicates the health of the liver.

ALKALOIDS: A large group of organic bases that most often occurs in seed.

ALLERGEN: Any substance that causes an allergy.

ALLERGY: An immediate or delayed immune reaction caused by the presence of foreign antigens.

ALLOGENETIC: Refers to having cell-types that are distinct and cause reactions in the immune system.

ALOPECIA: Transient hair loss resulting from use of certain therapies.

ALPHA INTERFERON (trade names INTRON-A, ROFERON-A and WELLFERON-A): This cytokine is produced by leukocytes. Recombinant alpha interferon has anti-HIV and immunomodulatory activity, and inhibits growth of tumor cells. This biological product has proven effective and received FDA approval for the treatment of AIDS-associated Kaposi's sarcoma, hairy leukemia and genital warts. Alpha interferon is a very promising anti-HIV treatment alone or in combination with other antivirals such as AZT. In NIH trials, asymptomatic patients showed improvement of their immunological status, and developed less OIs than those on placebo.

ALPRAZOLAM (trade name XANAX): This is an approved drug for he treatment of mild anxiety disorders. The drug is a benzoiazepine analog.

ALTRUISTIC: Refers to behavior that is not necessarily beneficial to oneself, but which benefits others.

ALUM: An odorless, colorless, crystalline substance.

ALVEOLAR: Pertaining to the alveoli sac, the site of gas exchange in the lungs. They are approximately .25mm in size, and there are approximately 1.5 million in each lung.

ALZHEIMER'S DISEASE is a generative disorder of the brain. It usually begins in middle or late adult life and produces a progressive deterioration of mentation. While often attributed in ignorance to a hardening of the arteries, there is no known relationship between AD and ANY vascular disorder. While occasionally familial, in most instances it is not, and the cause remains entirely unknown.

AMANTADINE (Symmetrel): A drug which is believed to help Parkinson's disease patients by decreasing the rate of dopamine breakdown. Amantadine is a dopaminergic agonist which allows dopamine to remain in the synapse region to activate receptor sites.

AMEBIASIS: Infection caused by a tiny animal parasite, Entamoeba histolytica, which lives in the human large intestine.

AMERICAN MEDICAL ASSOCIATION (AMA): The largest physician oriented organization in American medicine.

AmFAR: The American Foundation for AIDS Research, a private, nonprofit agency which raises funds for AIDS research.

AMINO ACID: Any one of 20 or more organic acids, some of which are the building blocks for proteins and are necessary for metabolism and growth.

AMINOSALICYLIC ACID (Asacol): An aspirin derivative. This experimental drug is now in Phase III trials as a treatment for non-specific colonic inflammation in persons with HIV.

AMPLIGEN: (drug) mismatched double stranded RNA, an antiviral and immunomodulator. May slow or block the progression of LAS or ARC into full blown AIDS. Currently in clinical trials.

AMPHOTERICIN B: A prescription antibiotic administered intravenously to treat cryptococcol meningitis and other systemic fungal infections (similar to those described under fluconazole). It is the standard treatment for systemic fungal infections. (Systemic refers to an infection throughout the body.) It is also used to treat life-threatening infections such as cryptococcosis and histoplasmosis. Adverse reactions are only likely when given by injection; these include vomiting, fever, headache and - rarely - seizures.

AMPULES: Small, sealed glass containers used to hold a solution for hypodermic injection.

AMYLASE: A class of enzymes (proteins), it is secreted by salivary glands and the pancreas to aid digestion of food, an increase in amylase levels may indicate pancreatitis.

AMYOTROPHIC LATERAL SCLEROSIS (ALS) is a degenerative disorder of the central nervous system (CNS) which involves the major motor pathway. The cause is unknown and the disease usually begins in middle or late adult life. The patients develop progressive weakness, spasticity and loss of muscle tissue. There is no known treatment; the disease significantly decreases life expectancy.

ANALGESIC: Agent that reduces pain without reducing consciousness.

ANALOG (ANALOGUE): A chemical compound with a structure similar to that of another but differing from it in respect to a certain component; it may have a similar or opposite action metabolically.

ANAMNESTIC RESPONSE: The heightened immunologic reaction elicited by a second or subsequent exposure to a particular pathogenic microorganism or antigen after serum antibodies can no longer be detected in the blood.

ANAPHYLACTIC SHOCK: An often severe and sometimes fatal systemic reaction in a susceptible individual upon exposure to a specific antigen (as wasp venom or penicillin) after previous sensitization that is characterized especially by respiratory symptoms, fainting, itching, urticaria, swelling of the throat or other mucous membranes and a sudden decline in blood pressure.

ANEMIA: A condition is which there are not enough healthy red-blood cells in the bloodstream or too little hemoglobin in the red-blood cells.

ANERGY: Lack of response to a foreign substance which 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.

ANSAMYCIN (trade name RIFABUTIN): This is an investigational drug for treatment of infections with mycobacterium avium intracellulare (MAI). Since 1983, 3,000 patients with life threatening mycobacterium infections received this drug from the Centers for Disease Control (CDC). The CDC no longer provides this drug to these patients. The drug is available under compassionate use in Canada. Thus far, the trials conducted with MAI patients have not yielded the results necessary for approval of the drug. The Phase III trial tests ansamycin's ability to prevent or delay the onset of MAI infection in patients with HIV.

ANTABUSE (DISULFIRAM): A prescription drug used to treat alcohol addiction. Antabuse is metabolized in part to diethyldithiocarbamate (DTC), which is also manufactured as a drug, by the French pharmaceutical manufacturer Merieux Institute, Inc. The exact percentage of antabuse that converts to DTC in the bloodstream is uncertain. DTC is a potential immune stimulant and has been in trial in the US since 1987. Reports from trials in Europe continue to suggest possible immune enhancement for DTC.

ANTAGONIST: A drug that prevents or reverses the action of another drug.

ANTIBACTERIAL: A substance which stops or checks the growth of bacteria.

ANTIBIOTIC: A substance that kills or inhibits the growth of organisms and is used to combat disease and infection.

ANTIBODY (Ab): Molecules in the blood or secretory fluids that tag, destroy or neutralize bacteria, viruses, or other harmful toxins. They are members of a class of proteins known as immunoglobulin, which are produced and secreted by B-lymphocytes in response to stimulation by antigens.

ANTIBODY-DEPENDENT CELL-MEDIATED CYTOTOXICITY (ADCC): An immune response in which antibodies coat target cells, making them vulnerable to attack by killing cells.

ANTICHOLINERGIC: An adjective used to describe a chemical, a drug or a drug effect that relates to acetylcholine inactivity or blockade.

ANTICHOLINERGIC DRUGS (Artane, Benedryl, Cogentin, etc.): These agents diminish the effect of acetylcholine, a neurotransmitter that in many ways counteracts the effect of dopamine in the brain. These agents are used as ancillary drugs in the treatment of the symptoms of Parkinson's disease and their side effects include dry mouth, blurred vision, difficulty with urination and occasional personality changes.

ANTICOAGULANT: A substance that delays or counteracts blood clotting.

ANTIEMETIC: A drug that prevents or stops nausea and vomiting.

ANTIFOLATE: An agent that inhibits intracellular production of folinic acid.

ANTIFUNGAL: A substance which kills or inhibits the growth of a fungus.

ANTIGEN (Ag): A foreign protein that can cause an immune response by stimulating the production of antibodies in the body. Proteins have a very complex and almost infinitely variable chemical composition and are constituents of all living matter. Common examples of antigens are the bacteria and viruses that cause human disease. The antibody formed in response to a particular antigen s unique to that antigen, reacting with no other.

ANTIGEN DEPENDANT CELL MEDIATED CYTOTOXICITY (or ANTIBODY- DEPENDANT CELLULAR CYTOTOXICITY): A condition by which a T-cell destroys a cell coated with an antibody. This is one of the two major mechanisms the immune system uses to destroy tumor cells.

ANTIGENEMIA: the presence of detectable amounts of antigens in the blood.

ANTI-IDIOTYPE: An antibody that recognizes and binds to another antibody (idiotype).

ANTI-INFECTIVE: Substance which treats opportunistic infections.

ANTI-INFLAMMATORY: A substance which counteracts or suppresses inflammation. There are two types: steroidal agents, such as cortisone, and non-steroidal agents, such as aspirin or colchicine.

ANTIMICROBIAL THERAPY: Medicines taken to cure infections. (i.e. antibiotics, antifungals).

ANTI-NEOPLASTIC: Inhibiting or preventing the proliferation of tumor cells.

ANTIOXIDANT: A substance that prevents oxidation. These are often used in fats, oils and food to keep them from becoming rancid.

ANTIPROLIFERATIVE: A substance which stops cells from growing.

ANTIPROTOZOAL: A substance which kills or inhibits the growth of protozoa. For example, toxoplasmosis and cryptosporidiosis are caused by protozoan infections, which can be treated with such drugs.

ANTITOXIN: Antibody that recognize and inactivate toxins produced by certain bacteria, plants or animals.

ANTIRETROVIRAL: A substance that stops or suppresses the activity of a retrovirus such as the HIV. AZT is an antiretroviral drug.

ANTIVIRAL: A type of substance or process which destroys a virus or suppresses its pathogenic action.

ANTIVIRAL ACTIVITY: The action of an agent that stops or suppresses the activity of a virus.

APLASTIC ANEMIA: A condition of bone marrow failure that can be fatal if left untreated.

APPLICATION PENDING: Clinical trials have been completed, but the company has not yet submitted an application for marketing to the Food and Drug Administration (FDA).

APPLICATION SUBMITTED: An application for marketing has been submitted to the FDA.

APPROVED: The product has been approved for marketing by the FDA.

ARC (AIDS Related Complex): A term not officially defined or recognized by the CDC which has been used to describe a variety of symptoms and signs found in some persons infected with HIV. These may include recurrent fevers, unexplained weight loss, swollen lymph nodes, and/or fungus infection of the mouth and throat. Also commonly described as symptomatic HIV infection.

ARTHRALGIA: A pain in a joint.

ARV (AIDS Related Retrovirus): See HIV.

AS-101: An immunomodulator made by Wyeth-Ayerst, AS 101 is a chemically-synthesized ammonium of salt of tellurium which has been shown to enhance production of white blood cells and interleukin-2 and is currently in clinical trials for treatment of ARC and AIDS.

ASO: AIDS Service Organization

ASPERGILLOSIS: A disease caused by the fungus Aspergillus Fumigatus causing inflammatory lesions of the skin, ear, orbit, nasal sinuses, lungs and sometimes the bones, meninges, heart, kidneys or spleen. Symptoms include fever, chills, difficulty breathing, and coughing up blood. If the infection reaches the brain, it may cause dementia. Treatment involves the administration of intravenous amphotericin B. (O.I.)

ASPERGILLOMYCOSIS: See ASPERGILOSIS

ASSAY: A test to detect the presence and concentration of a drug or substance in the blood, other body fluids, or body tissues.

ASTHMA: A spasm or sudden temporary narrowing of the airways in the lungs which results in wheezing and shortness of breath. In different people, asthma may be triggered by hay fever, food or other allergies, exercise, emotional stress, or a particular drug.

ASYMPTOMATIC INFECTION: An infection, or phase of an infection, without symptoms.

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.

ATAXIA: Loss of muscle control leading to jerky or uncoordinated movements.

ATROPHY: A wasting or decrease in size.

ATTENUATED VIRUS: A weakened virus whose ability to infect or produce disease is potentially reduced.

AUTOANTIBODIES: Antibodies that mistakenly attack host cells.

AUTOIMMUNE: A condition in which the body's immune system turns against its own tissue.

AUTOIMMUNIZATION: The induction in an individual of an immune response to its own cells (tissue).

AUTOIMMINE DISEASE: A disease which arises from and is directed against an individual's own tissues.

AUTOLOGOUS: Pertaining to the same organism or one of its parts, such as autologous blood draws for elective surgery or grafts.

AVEROL: (drug) Substance developed from sea sponges. A German-Japanese research team at the University of Mainz has suggested it may be effective against AIDS. The Frankfurt based pharmaceutical concern Marz, which holds the patent on Averol, is developing an injectable solution and hopes to begin clinical trials.

AXON: A long structure in the nerve cell that acts as a pathway for nerve impulses.

AZDU (AZIDOURIDINE): This drug is a nucleoside analog made by Triton Biosciences. The compound appears to suppress HIV, and to interfere with the ability of the virus to replicate inside human cells. It may also counteract HIV and delay progression of AIDS. AZDU seems to produce few toxic side effects, but hasn't made it beyond Phase I trials because of lack of interest from Triton.

AZM (ZITHROMAX, AZITHROMYCIN): Made by Pfizer. A macrolide antibiotic, under study for the treatment and prophylaxis of toxoplasmic encephalitis, treatment of mycobacterium avium complex (MAC), and treatment of cryptosporidiosis. Available under compassionate use for persons who have failed standard therapy for toxoplasmosis. Contact Dr. Michael DeBruin at (203) 441-5701.

AZT (AZIDOTHYMIDINE; ZIDOVUDINE; trade name RETROVIR): Dihydro methyl pyridinyl carbonyl azido dideoxythymidine. This drug, a pyrimidine nucleoside analog is the only anti-HIV medicine approved for treatment of patients with AIDS or severe ARC. Two large government placebo trials have tested AZT in HIV-infected adults with early ARC (ACTG 016) or who had no symptoms (ACTG 019). The trials were halted in August 1989. The data reviewed by NIAID showed AZT treatment hindered disease progression in people in both trials who had T4 cell counts between 200-500. The federal agencies, NIAID, the FDA, and Burroughs Wellcome Company are currently developing procedures to make the drug available to persons who need it. On October 25, 1989, AZT became available free for treating children with AIDS or at advanced stages of HIV virus infection under a Treatment IND (investigational new drug) program sponsored by burroughs Wellcome. Physicians interested in enrolling patients in the Treatment IND protocol may call 1-800-829-PEDS (toll free). Trials investigating the efficacy and safety of AZT are continuing.

B CELL: One of the immune system cell types; B cells fight infection primarily by making antibodies.

B-LYMPHOCYTES (B-CELLS): One of the two major classes of lymphocytes. During infections, these cells are transformed into plasma cells which produce antibodies specific to the pathogen. This transformation occurs through interactions with various types of T Cells and other components of the immune system.

BACLOFEN (Lioresal): An agent that presumably increases GABA activity. It has been used to help control some side effects of chronic dopaminergic therapy, especially dystonias.

BACTERIA: One group of microscopic organisms, many of which can cause disease when they infect someone.

BACTERIALCIDAL: Capable of killing bacteria.

BACTERIOSTATIC: Capable of inhibiting reproduction of bacteria.

BACTRIM (trade name): See TMP/SMX

BACTERIUM: A microscopic organism composed of a single cell. Many bacteria can cause disease in man.

BASAL CELL CARCINOMA: A common skin cancer.

BASAL GANGLIA: A group of brain areas that collectively are involved with control of normal movement and walking. The caudate nucleus and putamen (striatum), globus pallidus and substantia nigra are important basal ganglia structures.

BASELINE: A known value with which later measurements can be compared (e.g. baseline temperature, baseline hemoglobin level).

BASOPHIL: A type of white blood cell, also called a granular leukocyte, filled with granules of toxic chemicals, that can digest microorganisms. Basophils are responsible for the symptoms of allergy.

BENIGN: Mild type or character that does not threaten health or life as in benign tumor.

BENZODIAZIPINE: A general name for a certain group of tranquilizers, such as valium.

BETA-BLOCKERS: Drugs which block one of the two types of receptors for neurotransmitter norepinephrine (noradrenaline). The major use of these drugs is in the treatment of hypertension and heart disease, but they are also frequently used in the treatment of benign, essential tremor. The best known of these is Inderal (propranolol).

BETA ENDORPHIN: A hormone in the body related to opiate pain relievers; involved in coping with acute stress. Its functions include control of pain and fear, increase in airflow to the lungs, reduction of gastrointestinal activity to shift blood to the brain and muscles and mobilization of the immune system.

BETA INTERFERON (trade name BETASERON): Recombinant beta interferon exhibits the same antiviral, immunomodulatory and anti-cancer activity as the beta interferon produced naturally by the body. Like alpha interferon, in laboratory studies beta interferon stops replication of HIV. Larger clinical trials using this combination are presently under way.

BETA-2 MICROGLOBULIN: A protein found in the blood. Higher than normal amounts of this protein in the blood indicate replication of HIV and progression of HIV disease.

BETASERON: A recombinant form of human interferon beta made by Triton Biosciences. Currently in Phase II and III testing for treatment of HIV and Kaposi's Sarcoma.

BHT (Butylated hydroxytoluene): BHT is a manufactured antioxidant used in fats and oils as a food preservative. BHT inactivates a variety of viruses with lipids in their envelopes, including cytomegalovirus (CMV) and the Semiliki Forest virus. BHT also inactivates the herpes simplex virus (HSV). Cytomegalovirus and the herpes virus are two possible cofactors in HIV progression, and both lead to life-threatening illnesses in individuals whose immune systems have been damaged by HIV. Researchers believe the drug inactivates CMV and HSV by affecting their lipid envelopes. Animal studies on BHT show the drug protects against Newcastle disease virus at extremely low doses (100 to 200 parts per million of total diet). The envelope of HIV contains lipids similar to those found in Newcastle disease virus.

BILIRUBIN: A reddish yellow pigment occurring in bile, blood, urine and gallstones. An elevated level is a fair indicator that something is wrong with the liver, pancreas, or bile ducts and eyes often become jaundiced or yellow in color. Indicates the health status of the liver.

BIOAVAILABILITY: The rate and extent to which a substance is absorbed and circulated in the body.

BIOLOGICALS (Biological Products): Medicines made by living organisms, including humans. These products include gamma globulins, vaccines, etc.

BIOLOGICAL RESPONSE MODIFIERS (BRMs): Substances, either natural or synthesized, that boost, direct or restore normal immune defenses. BRMs include interferons, interleukins, thymus hormones and monoclonal antibodies.

BIOPSY: Removal and laboratory examination of tissue from the living body.

BIOSYNTHESIS: The building up of a chemical compound in the physiologic processes of a living organism.

BIOTECHNOLOGY: The use of living organisms or their products to make or modify a substance. These include recombinant DNA techniques (genetic engineering) and hybridoma technology.

BI-RG-587: An antiviral drug developed by Boeringer Ingelheim to block reverse transcriptase, an enzyme used by HIV during the process of replication; currently in Phase I studies.

BLASTOGENIC: The process of producing newly matured lymphocytes (a type of white blood cell) in response to a challenge by infectious agents such as bacteria and viruses.

BLASTOMYCOSIS: An infectious disease caused by a fungus, usually in the lungs. It can spread to the skin, bone or other tissues.

BLEPHAROSPASM: Uncontrolled closure of the eyelids. These movements are seen in a variety of movement disorders including, at times, Parkinson's disease.

BLOOD BRAIN BARRIER: A barrier between brain blood vessels and brain tissues whose effect is to restrict what may pass from the blood into the brain. This barrier presents a problem in treating HIV infection because treatments must cross it to stop HIV infection in the brain.

BODY FLUIDS: Term used for a number of fluids manufactured within the body. Usually used when referring to semen, blood, urine and saliva. Though some of these fluids have been found to contain traces of the AIDS virus, not all are thought to be able to transmit the virus to another person. Those fluids which are believed to transmit the virus are semen, blood, vaginal secretions, menstrual blood, and breast milk. Tears, sweat, and saliva are not viewed as effective means of transmission.

BONE MARROW: Soft tissue located in the cavities of the bones where blood cells are formed, including erythrocytes, leukocytes and platelets.

BONE MARROW CELL POOL: Those bone marrow cells responsible for the production of blood cells.

BONE MARROW SUPPRESSION: A condition that can be caused by certain drugs. It leads to a decrease in white blood cells, red blood cells, and platelets, which can lead to bleeding or infections. People taking medications known to cause bone marrow suppression should have frequent blood tests.

BRADYKINESIA: Often used interchangeably with akinesia, the term means a difficulty in initiating, or a lack of movement: it is one of the four hallmarks of parkinsonism.

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.

BRONCHOSCOPY: Visualization of the trachea and lungs with flexible fiber optics. Often used as a diagnostic tool for PCP.

BROPIRIMINE: An immunomodulator made by Upjohn which is currently in Phase II testing for treatment of Kaposi's Sarcoma.

BUFFERED: Coated or encased in a special substance which allows easier absorption of a medication by neutralizing the acidic environment of the stomach.

BURKITT'S LYMPHOMA: A malignant cancer of the lymphatic system. Epstein-Barr virus has been isolated from Burkitt's lymphoma and is suspected as a causative agent. (O.I.)

BUSPAR (trade name): Also known as Buspirone, this new drug is a non-benzodiazepine anti-anxiety drug. The drug is reported to be non-addictive, unlike Valium-type drugs.

BUTYL-DNJ (N-butyldeoxynjirimycin): made by G.D. Searle, butyl-DNJ inhibits protein N-glcosylation which is essential to the ability of HIV to infect healthy cells. Currently in Phase I trials.

BUYERS CLUBS: Non-profit organizations serving the PWA community by selling medications that are not FDA approved and, therefore, not available in pharmacies.

CACHEXIA: General ill health and malnutrition. A general weight loss and wasting occurring in the course of a chronic disease or emotional disturbance.

CAMPYLOBACTER: A genus of bacteria, one of which causes gastroenteritis in humans. (O.I.)

CANCER: A large group of diseases characterized by uncontrolled growth and spread of abnormal cells.

CANDIDA: A yeast-like fungi, commonly found in the normal flora of the mouth, skin, intestinal tract and vagina, but can become clinically infectious in immune compromised people.

CANDIDIASIS: A yeast-like fungal infection caused by Candida family, generally albicans, which affects membranes, the skin (dermatocandidiasis) and internal organs. Oral infections (thrush) exhibit creamy white patches of exudate on inflamed and painful mucosa. Common sites are the nailbeds, axilla (armpit), umbilicus, around the anus, the esophagus (candida esophagitis), respiratory tract (bronchocandidiasis), and the vaginal area (vaginitis). It may occur systemically and affect the heart and the meninges. Candida infections usually respond to treatment with an antifungal drug such as a nystatin--in the form of a mouthwash, lozenge, suppository, or cream; intestinal infection is treated with oral medication. PWAs may get a generalized candida infection involving most organs. This is life threatening and sometimes requires the intravenous administration of powerful (and quite toxic) antifungal agent(s). This infection has become a standard problem seen in immune depressed people. Candidiasis of the esophagus, trachea, bronchi or lungs is an indicator disease for AIDS. (O.I.)

CAPSID: The protein covering that covers the nucleic acid core of a virus.

CARBIDOPA: This drug prevents levodopa from being broken down by enzymes in the body and excreted before it reaches the brain. With carbidopa, a higher percentage of ingested levodopa can arrive at the brain and be converted to dopamine which acts at the striata receptor sites where it is needed. Carbidopa combined with levodopa is marketed as Sinemet and is presently the drug of choice for most patients.

CARCINOGEN: ("Cancer causing"). Any cancer-producing agent or substance.

CARCINOGENICITY: The ability of a chemical or physical agent (drugs, radioactivity, x-rays) to facilitate the development of cancer, generally after a long latency period.

CARCINOMA: A malignant tumor that may spread to other parts of the body.

CARRISYN (Acemannan): Carrisyn is extracted from aloe vera gel, which is derived from the aloe barbadenisis plant. Researchers believe that the active ingredient with antiviral activity in aloe is a polysaccharide. Carrisyn shows antiviral activity against the measles virus and herpes viruses.

CASCADE: The continuation of a process through a series of steps. Each step initiates the next step until the final step is reached. The action may or may not become cumulative as each step progress.

CASE-CONTROL STUDY: An epidemiological method in which persons with a disease condition are compared with a healthy population similar in age, sex, race, etc., to determine the differences between them.

CATECHOLAMINE: A class of chemicals, two of which are known to be important to brain function. These are dopamine and norepinephrine.

CATHETER: A semi-permanent tubular medical device for insertion into canals, vessels, passageways, or body cavities to permit injection or withdrawal of fluids or to keep a passage open.

CBCT: Community Based Clinical Trials.

CBO: Community Based Organization.

CC: Abreviation for cubic centimeter.

CD4: (T4) The protein embedded on the surface of T-helper and other white-blood cells to which HIV attaches itself. Also found to a lesser degree on the surface of monocyte/macrophage, Langerhans cells, astrocytes, keratinocytes and glial cells. HIV invades cells first by attaching to the CD4 molecule (CD4 receptor).

CD4-IgG: a genetically-engineered, experimental anti-HIV drug, produced by Genentech, Inc.

CD4 IMMUNOADHESIN: A hybrid of CD4, called a CD4 immunoadhesin, also blocks AIDS infection of blood cells in the test tube. In addition, the hybrid was able to bind to special sites on white-blood cells in the test tube, suggesting that in people it may trigger an immune system attack on the virus and AIDS-infected blood cells.

CD4-PSEUDOMONAS EXOTOXIN: A genetically engineered drug developed to seek out and kill cells infected with HIV. CD4 alone may prevent spread of infection between cells, but it does not kill cells already infected with HIV.

CD8: (T8) A protein embedded in the cell surface of suppressor T-lymphocytes.

CDC: The Centers for Disease Control. A federal health agency that is a branch of the Public Health Service. The CDC provides national health and safety guidelines and statistical data on AIDS and other communicable diseases; including disease surveillance, licensing of clinical laboratories, conducting research and training of epidemiologists and health workers.

CELL: The smallest independent unit of an organism. A cell is composed of cytoplasm and a nucleus, and is surrounded by a membrane or wall.

CELL LINES: Specific cell types artificially maintained in the laboratory (in-vitro) for scientific purposes.

CELL-MEDIATED IMMUNITY (CMI): The branch of the immune system in which the reaction to foreign material is performed by specific defence cells (killer cells, macrophage and other white blood cells) rather than antibodies.

CELL MEMBRANE: The wall around a cell that separates it from its environment.

CELL PROLIFERATION: The multiplication of similar cells.

CELLULAR IMMUNITY: Cell-mediated immunity.

CENTRAL NERVOUS SYSTEM: The brain and spinal cord with their nerves and end organs that control voluntary acts.

CEPHALOSPORIN: Antibiotic drug class that kills many bacterial germs that penicillin and sulfa drugs can't destroy.

CEREBRAL: Of or relating to the brain.

CEREBROSPINAL FLUID (CSF): Cerebrospinal fluid (CSF): A fluid which circulates around the brain and spinal cord. Examination of cerebrospinal fluid is important in diagnosing diseases of the central nervous system (CNS). Examination of CSF taken by needle for the lower back (lumbar puncture) or from the neck (cisternal puncture) helps in the diagnosis of neurological disease. CSF pressure and protein levels may be raised in cancer; in meningitis while cells and bacteria are found in the CSF.

CEREBROVASCULAR: Relating to the blood supply to the brain.

CERVICAL DYSPLASIA: Abnormal tissue development of the lower part of the uterus; may progress to cancer of the uterus.

CHANCROID: A highly contagious STD caused by hemophilus ducreyi bacterium that appears as a pimple on the skin of the genital organs and grows until finally bursting leaving a painful, pus-filled infectious venereal ulcer (chancre). Characterized by chancres that differ from those of syphilis in lacking firm indurated margins (soft chancres). Since Chancroid appears as a sore it is suspected as a route of transmission of AIDS. (O.I.)

CHELATING: Combining with a metal in complexes in which the metal is part of a ring.

CHEMOSUPPRESSION: Suppression of a virus or other organism through chemotheraphy, e.g. AZT suppression of HIV replication.

CHEMOTHERAPY: The use of chemical agents in the treatment of a disease.

CHLAMYDIA: A bacterial infection can which causes urethritis, conjunctivitis, and variety of other symptoms. Chlamydia occurs as a venereal disease independently of AIDS but can also appear as an opportunistic infection. (O.I.)

CHOLINE: A natural compound that may be used by the body to make acetycholine. Increasing acetylcholine concentrations in the brain could possibly be useful in controlling Huntington's disease, levodopa-induced dyskinesias, tardive dyskinesia and certain problems related to dementia. Increasing acetycholine concentration is hazardous to patients with Parkinson's disease.

CHOLINERGIC: An adjective used to describe a chemical, a drug or a drug effect that is related to acetylcholine.

CHOREA: A movement abnormality that can be seen in many diseases. It is characterized by fidgety irregular movements of the extremities and trunk, and often involves the lip and facial muscles. Chorea can be seen as a reversible side effect of chronic dopaminergic therapy in patients with Parkinson's disease, and it is symptomatic of Huntington's disease and Sydenham's chorea.

CHOROID: Blood vessel-rich tissue that nourishes the parts of the eye, especially the retina.

CHOROIDRETINITIS (CHOROIDITIS): Inflammation of the choroid (the middle coat of the retina). This may be caused by infections such as toxoplasmosis, tuberculosis, or syphilis. The condition is painless and the only symptom is blurring or loss of vision. (O.I.)

CHROMOSOME: A thread-like structure in the nucleus of a cell that contains genetic information encoded by DNA.

CHRONIC: Continuous or persistent condition of long duration.

CHRONIC FATIGUE SYNDROME (CFS): An illness characterized by significant fatigue, neurological, joint and muscle problems, chronicity and impairment of ability to function lasting 6 months or longer; accompanied by impairment in natural killer cell activity. CSF may be caused by an as yet undetected virus.

CHRONICALLY: The tendency to occur or be present on a long-term basis.

CILOFUNGIN: A treatment for candida infection of the throat. The drug was withdrawn from study by the manufacturer, Eli Lily, with no given reason.

CIMETIDINE (TAGAMET): A drug developed to treat peptic (stomach) ulcers by stopping the secretion of stomach acid.

CIPD: Chronic idiopathic demyelinating polyneuropathy.

CIRCULATING IMMUNE COMPLEXES (CIC): See Immune Complex.

CLARITHROMYCIN (CLM) (trade name: KLACID): An anti-infective under study for treatment and prophylaxis of mycobacterium avium complex (MAC) and treatment of toxoplasmosis. It is unlikely that clarithromycin alone will be effective against MAC, since the history of mycobacterial therapies points to a reliance on combinations of treatments; and because resistance to drugs appears to develop quickly.

CLINDAMYCIN: Clindamycin is an antibiotic, similar in structure to erythromycin, which acts to stop proteins production. Clindamycin combined with pyrimethamine is currently under investigation for the treatment and prophylaxis of toxoplasmosis - infection of the brain. Currently in Phase I and II testing for treatment of pneumocystis pneumonia (PCP).

CLINICAL: Based on observation of the condition of patients and their symptoms, as opposed to blood work or other laboratory tests.

CLINICAL COMPARISON STUDY: A clinical trial where the test drug is evaluated against an existing standard therapy rather than against a placebo.

CLINICAL TRIAL: A test to see how well a new drug works on people.

CLOFAMIZINE (CFZ): A drug sometimes used as a prophylaxis for MAI, currently in clinical trials.

CLONE: A group of genetically identical cells or organisms descended from a common ancestor. To produce such genetically identical copies.

CLOTRIMAZOLE TROCHE (trade name Mycelex): This troche is a slow-dissolving tablet containing 10 mg of clotrimazole, a synthetic fungal agent for topical use in the mouth. Clotrimazole is an antifungal that has activity against the fungal infection candida albicans.

CLOTTING FACTORS: Substances in the blood responsible for normal coagulation.

CMV RETINITIS: An infection of cytomegalovirus (CMV) in the retina of the eye which can cause blindness. "Peripheral CMV retinitis" refers to the early stages of the disease, which can become "sight-threatening" (a later stage that is considered to be an immediate threat to the patient's vision) if left untreated. (O.I.)

CNS (Central Nervous System): Composed of the brain, spinal cord, and its coverings (meninges).

COALESCE: The fusion of originally separate parts.

COFACTORS: Substances, microorganisms, or characteristics of individuals which may influence the progression of a disease or the likelihood of becoming ill.

COCCIDIOIDES IMMITIS: A type of fungus which can infect the lungs of people with AIDS, but can also spread to the skin, gastrointestinal tract and central nervous system.

COCCIDIOMYCOSIS: (California Disease, Desert Fever, Desert Rheumatism, San Joaquin Valley Fever, Valley Fever): A fungal disease caused by infection with Coccidioides immitis. It occurs in two forms. The first is an acute, benign, self-limiting respiratory infection due to inhalation of spores and varying in severity from a mild infection similar to the common cold or flu which may later recur after apparent recovery to a very severe infection with pneumonia, high fever, and skin inflammation. The secondary form (or progressive coccidioidomycosis) is virulent and severe involving the lungs, central nervous system, and skin. Symptoms include anemia, inflammation of the veins, and various allergic reactions. (O.I.)

COGNITIVE: Relating to awareness with perception, reasoning and memory.

COHORT: A group of individuals sharing a statistical factor in a demographic study.

COLCHICINE: This is a natural product isolated from the lily family. Know for hundreds of years, it is an approved anti-inflammatory drug used in the treatment of gout. The drug has in vitro anti-HIV activity in HIV infected cells of three different types (Montreal 5th International Conference, June 1989). At the meeting, scientists suggested continuing studies of its in vitro effects and them cautiously starting the phase I trials to look at toxicity in HIV-infected individuals.

COLITIS: Inflammation of the colon.

COLON: The part of the large intestine that extends from the cecum to the rectum - the last three to five feet of intestine. Also called the "large intestine" or "large bowel".

COLONOSCOPE: A long flexible tube, containing fiber optics, used to examine the colon.

COLONOSCOPY: Examination of the colon using a colonoscope.

COLONY STIMULATING FACTORS: (CSFs) The production of white blood cells is controlled by proteins called colony stimulating factors. Cancer chemotherapy and inherited disorders are among the causes of low white blood counts, which lower resistance to infection. CSFs are being investigated not only as a way to counteract low white blood cell counts, but also as a way to produce specific types of white blood cells. In addition, there is hope that CSFs can stimulate the body to produce additional bone marrow as well as cause some cancer cells to stop dividing.

COMA: A state of unconsciousness in which movement and mental processes are impaired. People in deep coma cannot be aroused by external stimulus.

COMBINATION CHEMOTHERAPY: The use of two or more types of treatment, chemotherapy or radiation therapy, to achieve optimum results against the cancer.

COMBINATION THERAPY: The use of two or more types of treatment in combination, alternately or together, to achieve optimum results against HIV infection. Combinations may offer advantages over single drug therapy.

COMMUNITY-BASED CLINICAL TRIAL (CBCT): A complement to traditional academic research, CBCTs are conducted by primary-care physicians in close cooperation with patients and AIDS advocates.

COMMUNITY RESEARCH INITIATIVE (CRI): A non-profit community-based organization started in New York City in 1987 to perform scientific studies of AIDS treatments.

COMPARISON TRIAL: Experimental drugs are tested against each other or against an approved drug.

COMPARATIVE STUDY: A study comparing two things, such as two different drugs, or two dosages of the same drug.

COMPASSIONATE USE: A designated or method of releasing an investigational new drug when there is little established data as to its efficacy. The drug company is not generally allowed to charge for compassionate use and must be willing to give the drug free of charge to those patients whose medical condition might be helped by the use of this drug. Special approval must be obtained from the FDA for compassionate use of a drug. (Now termed Open Study protocol by the FDA).

COMPLEMENT: A group of proteins in normal blood serum and plasma that, in combination with antibodies, causes destruction of antigens (particularly bacteria and foreign blood corpuscles).

COMPLEMENT CASCADE: A precise sequence of events, usually triggered by an antigen-antibody complex, in which each component of the complement system is activated in turn.

COMPLETE BLOOD COUNT (CBC): Series of tests including cell counts, hematocrit, hemoglobin, and cell volume measurement.

COMPOUND Q: GLQ223 (an artificial form, produced by recombinant technology), or trichosanthin (a natural substance derived from Chinese cucumber root); a substance that shows strong, selective activity against HIV-infected cells. It also show very toxic side effects. Virtually ignored by the government, Compound Q continues to be tested in community-based studies.

CONCOMITANT DRUGS: Drugs taken together with possible adverse drug interactions.

CONCURRENT DRUGS: Drugs taken together without expected adverse drug interactions.

CONDYLOMA: A venereal wart caused by the papilloma virus. Condylomas exist as venereal infections independently of AIDS, but the immune suppression of AIDS may cause them to proliferate. They may be treated by the topical application of a drug, cryosurgery (a freezing technique), or with laser surgery depending on the size of the lesion. Because of their tendency to recur, treatment may have to be done several times. (O.I.)

CONJUNCTIVA: a membrane that lines the inside of the eyelid and touches the white part of the eye; secretes a mucous that lubricates the eyeballs.

CONTAGIOUS: Any infectious disease capable of being transmitted by casual contact from one person to another.

CONTINUOUS INFUSION: Uninterrupted introduction of fluid other than blood into a vein.

CONTRAINDICATION: ("to indicate against"). A specific circumstance as a symptom or condition that makes a particular treatment or procedure inadvisable.

CONTROL: A standard against which experimental observations may be evaluated.

CONTROLLED TRIALS: Generally trials in which one group gets the experimental drug. The other group, the control group, is given either a placebo or an approved drug therapy. Participants usually do not know which group they are in.

CORE PROTEIN: An integral protein in the HIV virus composed of three units, p24, p15, and p18.

CORNEA: the outermost layer of the 3 tissues that make up the wall of the eyeball; the clear, transparent, curved portion that covers the colored part of the eye; enables light rays to enter the eyeball.

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 manufactured synthetically such as corticosterone, cortisone, and aldosterone. Corticosteroids are immunosuppressive and people with HIV infection should be cautious about taking them.

CORTISOL (ALSO CALLED HYDROCORTISONE): A steroid hormone secreted by the adrenal cortex.

CORYNEBACTERIAL INFECTIONS: Infections by one of a genus of bacteria which include Listeria monocytogenes and are responsible for opportunistic infections in AIDS. (O.I.)

COTTON WOOL PATCHES: White spots in the internal layer of the retina (back lining of the eye). These spots indicate areas of blocked blood supply.

CPCRA: Community Programs for Clinical Research on AIDS. Part of the NIH's Division of AIDS.

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.

CREATININE: A protein found in muscles and blood and excreted by the kidneys in the urine. The level of creatinine in the blood and urine provides a measure of kidney function.

CREUTZFELDT-JAKOB / CREUTZFELDT-JAKOB DISEASE: A rare, usually fatal, transmissible viral encephalopathy, occurring in middle life, with brain degeneration, progressive dementia, wasting, tremor and erratic movement. Included here as another progressive neurological virus.

CROHN'S DISEASE: An inflammatory disease involving any part of the gastrointestinal tract from mouth to anus, but commonly involving the small intestine. It causes scarring and thickening of the bowel wall and often leads to intestinal obstruction and abscesses. It is characterized by recurrent episodes of abdominal pain (usually on the lower right side), diarrhea, fever, weight loss, and appetite depression. It is often mis-diagnosed as appendicitis. (O.I.)

CROSSOVER: A procedure in a controlled trial where halfway through the study the control group is taken off the control and given the experimental drug and vice versa.

CRYPTOCOCCAL MENINGITIS: A fungal infection caused by the Cryptococcus neoformans that affects the three membranes (meninges) surrounding the brain and spinal cord. Symptoms include severe headache, dizziness, nausea, anorexia, vision disorders, and mental deterioration. (See Cryptococcosis).

CRYPTOCOCCOSIS: An infectious disease seen in HIV-infected patients due to the fungus Cryptococcus neoformans which is acquired via the respiratory tract. It characteristically spreads to the meninges (the lining of the brain and spinal cord) and may be spread to the kidneys and skin. Meningitis with headache, blurred vision, confusion, depression, agitation or slurred speech are common symptoms. (See Cryptococcal Meningitis).

CRYPTOCCUS NEOFORMANS: A fungal parasite that can infect the lungs of people with AIDS, and may spread to the meninges (linings of the brain and spinal cord), lungs, kidneys and skin.

CRYPTOSPORIDIOSIS: An infection caused by a protozoan parasite found in the intestines of animals. Acquired in some people by direct contact with the infected animal or by ingestion of contaminated food or water, it lodges in the intestines and causes severe diarrhea. It may be transmitted from person to immunosuppressed people and can lead to prolonged symptoms which do not respond to most medications. On study reports a more short-lived illness in healthy persons which resolves spontaneously. (O.I.)

CRYPTOSPORIDIAL DIARRHEA: Caused by a parasite (cryptosporidium) and characterized by chronic, profuse, watery diarrhea, accompanied by fever, marked weight loss and enlarged lymph nodes. See cryptosporidiosis. (O.I.)

CT: Computed Tomography (CAT Scan).

CULTURE: The growth of microorganisms or living tissue in the laboratory, in solutions that promote their growth.

CUSHING'S SYNDROME: A set of symptoms often associated with steroid use. The syndrome includes high blood and urine sugar levels, high blood pressure and weight gain. The extra fat is often distributed in a particular way, giving a rounded look to the face, a "buffalo hump" appearance to the shoulders, and a central truncal obesity. Someone who looks this way is often described as "cushingoid".

CUTANEOUS: Pertaining to the skin.

CYTOKINES: Naturally occurring proteins that regulate or modify the growth of specific cells. They are soluble, hormone-like substances which are produced and released by lymphocytes. Proteins produced by white blood cells that act as chemical messengers between cells. CD8 (T-suppressor) cells release a cytokine that appears to block HIV replication in infected cells, at least until the advanced stage of HIV disease.

CYTOMEGALOVIRUS (CMV): A virus related to the herpes family, CMV infections may occur without any symptoms or may result in mild flu-like symptoms of aching, fever, mild sore throat, weakness or enlarged lymph nodes. Sever CMV infections can result in retinitis, hepatitis, mononucleosis, colitis, or pneumonia; especially in immune suppressed people. CMV is "shed" in body fluids such as urine, semen, saliva, feces, and sweat. Severe and fatal CMV infection is common in the terminal stages of AIDS. The virus is resistant to Acyclovir. Also, see CMV retinitis. (O.I.)

CYTOPENIA: Deficiency in the cellular elements of the blood.

CYTOPLASM: The watery material between the nucleus and membrane of the cell.

CYTOTOXIC: Term used to describe something which damages cells. Also used as the name of a type of T-cell.

CYTOTOXIC T LYMPHOCYTE: (CTL) A lymphocyte that is able to kill foreign cells that have been marked for destruction by the cellular immune system.

CYTOTOXICITY: An agent or process which is toxic to cells; that results in suppression of function or cell death.

D4T (2',3'-DIDEHYDRO 3'-DIDEOXYTHYMIDINE): This experimental drug is like a thymidine nucleoside analog like AZT. It acts like AZT and inhibits HIV by premature viral DNA chain termination.

DANAZOL: A drug that suppresses the action of the pituitary gland. It is used in the treatment of thrombocytopenia (ITP).

DAPSONE: This is an approved sulfa-type drug used to treat leprosy. In AIDS research, it is being tested for its ability to prevent Pneumocystis carinii pneumonia (PCP).

DARAPRIM: Trade name for an approved drug (also knopyrimethamine) used in treating toxoplasmosis in AIDS patients.

ddC (DIDEOXYCYTIDINE - HIVID): Like AZT, ddC is an experimental pyrimidine nucleoside analog which inhibited HIV in vitro, and was more potent than AZT in these tests. In initial clinical trials which administered ddC only, 35 out of 61 ddc-treated patients were taken off the drug due to toxicity; many patients developed peripheral neuropathy. The current trials of ddC control the toxicity of the drug by using much lower doses.

ddI (DIDEOXYINOSINE, trade name VIDEX): This experimental, anti-HIV drug is a purine nucleoside analog. The antiviral action of this drug is similar to that of AZT. In clinical trials, ddI is being compared to AZT to see which one works better. In two phase I trials sponsored by the federal AIDS program, patients treated with ddI showed increase of T-cell levels and falling of p24 levels. Toxicity due to ddI (pancreatitis and neuropathy) were shown at higher doses. The drug is also available to patients who need the drug and who do not qualify for the three clinical trials. DDI is available to these patients under a Treatment IND or compassionate use program. Doctors should inquire about enrolling patients in these protocols by calling the Company Bristol Myers at the toll free number, 1-800-662-7999.

DEHYDRATION: The state produced by abnormal loss of body water; the deprivation or loss of water from the tissues. Dehydration may arise from an inability to drink either because of difficulty in swallowing, or because the person is weak, drowsy, or comatose from any cause. Vomiting may both prevent fluid intake and increase fluid loss. Diarrhea may act in the same way, and a combination will lead to rapid dehydration. It is unusual for dehydration to occur as an isolated problem and may involve a gross loss of salt which may be more serious that the loss of body water. Symptoms of uncontrolled dehydration are thirst, followed by weakness, exhaustion, and finally delirium and death.

DELIRIUM: A clouding of consciousness in which perception is disordered. The person is often restless, anxious, and inattentive. Hallucinations, both auditory and visual occur and add to the person's distress. Symptoms range from mild, such as occasional wandering of the mind, to severe where confusion is so great that the patient is unable to recognize family, respond appropriately, or sleep and is prone to self-injury. In some bacterial infections, the accompanying delirium is thought to result from the action of toxins on certain parts of the brain. Treatment of delirium involves control of the underlying cause. Sedatives may be ordered to prevent the person from becoming exhausted or hurting himself.

DEMENTIA: Chronic intellectual impairment (loss of mental capacity) with organic origins, that affects a person's ability to function in a social or occupational setting. AIDS-related dementia may be caused by HIV or other opportunistic infections such as CMV. Literally, "loss of mind." Dementia can have many possible causes and mechanisms, but the constant feature is loss of memory, particularly for recent events. As it progresses, the person loses all intellectual powers and emotional control, with the result that their personality is completely degraded. (O.I.)

DEMYELINATING: Having to do with destruction of the myelin sheath that surrounds and insulates the axon of some nerves.

DEMYELINATION: Destruction, removal, or loss of the myelin sheath of a nerve or nerves.

DEPRENYL: An inhibitor of the enzyme monoamine-oxidase type B. This enzyme normally acts to degrade dopamine so that it is no longer active to stimulate brain dopamine receptors. Deprenyl, by antagonizing this breakdown sequence, has been used in an attempt to prolong dopamine activity.

DERMATITIS: inflammation of the skin.

DESCICLOVIR: A drug which is metabolized into acyclovir after absorbing into the body.

DEXAMETHASONE: A naturally occurring steroid with a potent anti-inflammatory effect in disorders of many organ systems.

DEXTRAN SULFATE (Uendex): A low toxicity antiviral. Dextran sulfate has several mechanisms of antiviral activity against HIV. In cell culture it blocks syncytia formation (cell-to-cell infection). AZT cannot block cell-to-cell infection. In laboratory studies dextran sulfate blocks HIV from binding and entering T-helper cells. The drug also works to block reverse transcriptase activity in cell cultures. Recent evidence also indicates that in laboratory experiments it blocks infection between macrophages.

DFMO: A drug active against pneumocystis (PCP) and may alleviate some of the symptoms of cryptosporidiosis. In vitro studies suggest that DFMO (Eflornithine) has a synergistic effect with ganciclovir, implying that lower, less toxic doses might be possible in the future to control retinitis.

DHEA (DEHYDROEPIANDROSTERONE, EL-10): the drug is available in Japan and Italy for the treatment of menopause, emotional instability, depression and stress. The drug may enhance the body's immune response, and may have anti-HIV activity.

DHPG: See ganciclovir (9-(1,3-dihydoxy-propoxymethyl)guanine).

DIABETES: Literally any disease which causes frequent urination, but most often it is used to refer to diabetes mellitus, a disease resulting in low levels or abnormal functioning of insulin in the body. Insulin is the protein which helps to control blood sugar levels. Symptoms of diabetes mellitus also include greatly increased thirst and high blood pressure.

DIAGNOSIS: The evaluation of a patient's medical history. Clinical symptoms and laboratory tests which confirm or establish the presence of disease or infection.

DICLAZURIL: An experimental drug being tested as a treatment for cryptosporidiosis in AIDS. The drug has potent activity against other coccidial infections in animals.

DISMUTASES: Dismutase, an enzyme, is important in organ transplantation and in treating heart attack where tissues have been deprived of blood for a short time. When the blood flow is restored to the transplanted organ or to the heart muscle after a clot is dissolved, the cells in the organ can be damaged by the excessively oxygen-rich blood. Dismutases prevent this "reperfusion injury" by allowing the oxygen-deprived tissue to recover their normal state in a more orderly manner.

DISSEMINATED: Scattered throughout the body.

DISTAL: Farthest from the center or from a central point of reference.

DNA: (Deoxyribonucleic Acid). A complex protein in the nucleus of a cell which contains the cell's genetic code and is the carrier of genetic information. HIV can insert itself into a cell's DNA and use cellular mechanisms for replication.

DNA SYNTHESIS: The process of manufacturing molecules of DNA, the genetic material of all living organisms.

DOPAMINE: A chemical found in the body and brain that is felt to be important as a neurotransmitter. Its action in the brain appears important for the facilitation of normal movement. Its highest concentration is in the basal ganglia (striatum). It is involved in producing a sense of general energy, spontaneity and elevated mood.

DOPAMINERGIC: An adjective used to describe a chemical, a drug or a drug effect related to dopamine.

DORMANCY: See latency.

DOSE: The amount of a drug that is given at one time.

DOSE COMPARISON: A trial that uses different amounts of the same drug. Sometimes the drug tested against is a placebo.

DOSE ESCALATION: A drug trial in which the amount of the drug is increased with each new trial group.

DOSE RANGING: A drug trial in which two or more doses of a given drug are being tested against each other in order to determine which dose works best and is the least harmful.

DOUBLE BLIND: A trial design in which neither the experimental subjects nor administering doctors are told which subjects are receiving test drugs and hich are receiving placebo or other therapy. Believed to promote faster and more objective results, as doctor's and patient's biased expectations about a test drug's efficacy are reduced.

DOXORUBICIN (trade name ADRIAMYCIN): An approved drug for many types of neoplastic conditions (cancers) such as leukemias, sarcomas, carcinomas, and lymphomas.

DRUG-INDUCED PARKINSONISM: In patients receiving neuroleptic drugs, the dopaminergic system is underactive because of drug-induced receptor site blockade. In patients receiving reserpine for hypertension (high blood pressure), the dopaminergic system is underactive because this drug depletes the brain of dopamine. All of these agents will cause parkinsonism that is usually reversible when the offending medication is stopped. Patients with drug-induced parkinsonism look the same as patients with Parkinson's disease, but the cause and treatment of the two conditions are different.

DUNHL: see Non-Hodgkin's Lymphoma.

DYSFUNCTION: Poor functioning or abnormal functioning of a cell or organ of the body.

DYSKINESIA: Abnormal, rapid, involuntary movement(s) most commonly appearing as protrusions of the tongue or mouthing movements of the lips, but which may involve any part of the body. Like the word parkinsonism, dyskinesia is a descriptive term, and may be due to many factors including levodopa-induced dyskinesias and tardive dyskinesia. Dyskinesias appear to relate to the dopaminergic system and may relate to altered sensitivity of receptor sites in the brain to neurotransmitters.

DYSPLASIA: The abnormal development of tissue. In disease, the alteration of size, shape and organization of adult cells.

DYSTONIA: A motor disorder consisting of forceful, spasmodic twisting or jerking movements. It frequently worsens during motor activity or emotional stress, subsiding when the patient sleeps. Dystonic posture may occur as part of a neurologic disease or as a reaction to drug treatment or as a result of an injury or trauma. If confined to the muscles of the neck with onset occurring in middle life, it is usually called spasmodic torticollis. Present medical therapy is erratic and of limited clinical value.

EASTERN COORDINATING ONCOLOGY GROUP (ECOG) PERFORMANCE STATUS: A system used to measure a person's ability to function (0=normal; 1=capable of self-care, able to do light work; 2=bedridden less than 50 percent of the time; 3=bedridden more than 50 percent of the time; 4=completely bedridden.

EFFECTIVE DRUG: According to the FDA, a drug that benefits patients for a specific disease.

EFFICACY: Strength, efficiency. The ability to achieve a desired effect.

EIA: (Enzyme immunoassay) see ELISA. A blood test to determine HIV infection.

ELECTROENCEPHALOGRAM: The record obtained by means of the electroencephalograph.

ELECTROLYTE: Electrically-charged salts found in blood, tissue, fluids, and cells, including the salts of sodium, potassium, and chlorine.

ELECTRON BEAM THERAPY: A type of radiation therapy.

ELFORNITHINE (DFMO): This is an experimental antiprotozoa drug available to treat pneumocystis carinii pneumonia (PCP). It is only available on a patient by patient basis under a compassionate use protocol.

ELISA: (Enzyme linked immunosorbent assay) A testing method to detect antibodies to HIV. Also see Western Blot. Does not detect AIDS, only indicates if viral infection has occurred.

EMPIRICAL TREATMENT: Treatment undertaken when a precise diagnosis cannot be made, based on experience with similar cases.

ENCEPHALITIS: inflammation of the brain, usual viral but sometimes bacterial in origin. Symptoms include headache, neck pain, fever, nausea, and vomiting. Nervous systems problems may occur such as laziness, paralysis, weakness, and coma. Treatment includes antibiotics for infection, steroids to reduce brain swelling, medicine to control fever and headache, and prolonged bedrest. Several types of opportunistic infections can cause encephalitis. (O.I.)

ENCEPHALOPATHY: Disease of the brain.

ENDEMIC: Pertaining to diseases associated with particular locals or population groups.

ENDOCRINE GLANDS: The organs in the body that are responsible for producing hormones.

ENDOGENOUS: Relating to or produced by the body.

ENDORPHINERGIC: Endorphin-like or endorphin-related (see beta endorphins above for description of their activity).

ENDORPHINS: A group of hormones including Beta endorphin, metenkephalin, levenkephalin and dynorphin (see Beta endorphin above for description of their functions.

ENDOSCOPY: Viewing the inside of a body cavity with a device using flexible fiber optics.

ENDOTHELIAL: Pertaining to the endothelium, cells that line blood vessels, the heart, and other body cavities.

ENDOTHELIAL CELLS: Cells that line blood and lymphatic vessels and the heart.

ENDOTOXIN: A toxin present inside a bacteria cell.

ENTERIC: Of or relating to the intestines.

ENTERIC PATHOGENS: Disease causing organisms infecting the gastrointestinal tract and sometimes spreading from there to other parts of the body.

ENTERITIS: Inflammation of the intestines.

ENVELOPE: A natural covering. The HIV envelope is composed of two units; gp120 and gp41. gp120 is the portion of HIV which binds to a helper T cell's surface protein, CD4.

ENZYME: Protein chemical that can accelerate a chemical reaction in the body.

EOSINOPHIL: a type of white blood cell, called a granulocyte, that can digest microorganisms.

EPIDEMIC: An outbreak of a disease among a population.

EPIDEMIOLOGY: The science concerned with the determination of the specific causes of distribution of a disease of the interrelation between various factors determining a disease.

EPITOPE: A unique shape or marker carried on an antigen's surface which triggers a corresponding antibody response.

EPSTEIN-BARR VIRUS (EBV): A herpes-like virus that causes one of the two kinds of mononucleosis (the other is caused by CMV). It infects the nose and throat and is contagious. EBV lies dormant in the lymph glands and has been associated with Burkitt's lymphoma , a cancer of the lymph tissue, and hairy leukoplakia. This is one of the clearest links to date between viruses and cancer. (O.I.)

ERYTHEMATOUS: Red or reddened.

ERYTHROCYTES: Red blood cells whose primary function is to carry oxygen to cells.

ERYTHROPOIETIN (EPO, trade name EPREX): Kidney disease often impairs the body's ability to produce this hormone, causing anemia, a deficiency in red blood cell production. Requires frequent blood transfusions, or restoration of the missing hormone (EPO). Since transfusions may expose those who receive them to infectious agents, EPOs are available through genetic engineering in large amounts. Researchers are looking for ways to use EPO to treat anemia caused by retrovir (AZT) in PWAs. EPO is a cytokine which stimulates red blood cell formation. Recombinant EPO is a prescription drug for kidney disease. The drug is currently used to treat anemia in AIDS patients with hematocrit (red cell count) less than 30% under a treatment IND program. Doctors can request this drug for their patients by calling Ortho Pharmaceuticals at their toll-free number 1-800-243-7739.

ESOPHAGEAL/GASTRIC CANDIDIASIS: A fungal infection of the stomach and/or esophagus (gullet) that often produces pain with swallowing and weight loss; an AIDS-defining opportunistic infection.

ESOPHAGITIS: Inflammation of the lower part of the esophagus, the tube connecting the throat and the stomach.

ESSENTIAL TREMOR (benign, familial tremor): This sort of tremor differs from the tremor of Parkinson's disease in that it is usually minimal or not present at rest and is increased when the patient moves his hands, especially in writing. The handwriting of a patient with essential tremor is usually large and sloppy as opposed to the micrographic handwriting of a patient with Parkinson's disease. Essential tremor is often associated with head-shaking and may also be associated with walking difficulties (titubation). These walking problems differ from those of parkinson's patients who walk with their feet close together, while those with essential tremor may walk with their legs far apart (ataxia). Essential tremor occurring in families is termed specifically familial tremor.

ETHAMBUTOL (MYAMBUTOL): An oral drug used in combination with other agents to treat tuberculosis; under study, in combination with other drugs, as a treatment for MAI; side effects may include decreased or distorted vision.

ETIOLOGY: The study or theory of factors which cause disease.

ETOPOSIDE (trade name VePESID): An approved drug found useful in the treatment of cancer or the testicles and small cell lung cancer.

EXOGENOUS: Developed or originating outside the body.

EXOTOXIN: A toxic substance made by bacteria that is released outside the bacterial cell.

EXPANDED ACCESS: A system for distributing experimental drugs to patients who are unable to participate in ongoing clinical efficacy trials and have no other treatment options available.

EXPERIMENTAL DRUG: A drug that has not been approved for use as a treatment for a specific condition in a specific population.

EXTRACORPOREAL: Outside of the body.

FACTOR VIIIs: Because hemophiliacs lack the clotting protein Factor VIII, they often suffer internal bleeding, which requires infusions of the protein derived from human blood. In the early 1980s the transfusions sometimes were found to be contaminated with the HIV virus. After 1984, manufacturers devised ways to kill the virus in the clotting protein. Through genetic engineering, researchers can make a Factor VIII that will be HIV-free.

FALSE NEGATIVE: An erroneous test result that indicates that no antibodies are present when in fact they are.

FALSE POSITIVE: An erroneous test result that indicates that antibodies are present when in fact there are none.

FANSIDAR: An anti-malarial agent containing two drugs, sulfadoxine (25mg) and pyrimethamine (500mg). It has been used to treat PCP and forms of resistant malaria. Severe side effects have been associated with its use.

FATTY ACIDS: A group of lipids found in animal fats. Some fatty acids are essential for good nutrition.

FESTINATION: A tendency to take shorter, quicker steps in walking. Like micrographia (handwriting becoming smaller in a sentence), it is a sign of Parkinson's disease.

FOOD AND DRUG ADMINISTRATION (FDA): The agency of the federal government responsible for the regulation of drugs.

FIACITIBINE (FIAC): A drug manufactured by Oclassen which is active against all the herpes viruses, as well as the hepatitis B virus. Although FIAC is a nucleoside analog like AZT and ddI, it has no effect on HIV. One early advantage seen with FIAC is its ability to be administered in an oral form. FIAC was first studied in the early 1980s at Memorial Sloan-Kettering Hospital in New York for treating severe cytomegalovirus infections, and demonstrated some bone-marrow toxicity and gastrointestinal upsets. At the manufacturer's request, a version made by Janssen was withdrawn from a study as a treatment for cryptosporidiosis because of poor patient compliance.

FIALURUDINE (FIAU): Manufactured by Oclassen, FIAU is indicated for treatment of herpes infections and also shows action against HIV. Currently in Phase I testing.

FIBROBLAST: Any cell from which connective tissue is developed.

FLAME RETINAL HEMORRHAGE: bright red bleeding in the inner surface of the retina in a flame-shaped configuration with feathered edges.

FLOATERS: Floating dark spots within the field of vision. They can be caused by CMV retinitis, but also appear in some persons as a normal part of the aging process. An HIV-knowledgeable opthamologist can make a correct diagnosis.

FLUCONAZOLE (trade name DIFLUCAN): A broad spectrum antifungal drug (manufactured by Pfizer Pharmaceuticals) in the triazole class that can be given oral or intravenous administration. According to company sources, the drug will be approved by the FDA for oral candidiasis and cryptococcal meningitis (CM) in February 1990. An alternate therapy for CM is the antifungal drug, Amphotericin B (AMB). Fluconazole continues to be studied for CM, oral candidiasis and other fungal infections.

FLUCYTOSINE: An anti-fungal drug usually given with the drug amphotericin B in order to decrease the emergence of resistant strains of fungi. The trade name is Ancobon.

FLUOROTHYMIDINE: A type of drug in preclinical development which is designed to inhibit the reverse transcriptase process.

FOLLICULITIS: A bacterial infection of the hair follicles that occurs most commonly in the hairy areas of the groin, armpit or face.

FOSCARNET (TRISODIUM PHOSPHONOFORMATE, PFA): This experimental drug is very active against CMV. It also inhibits other herpes viruses and HIV. Foscarnet trials are currently underway nationwide for CMV retinitis, the primary HIV infection and for histoplasmosis infections.

FUNDI: Plural of fundus, which refers to the back wall of the eye or retina. A fundic exam is an exam where someone looks inside the eye with a light to see the structures on the back wall.

FUNGUS: A general term used to denote a class of microbes including mushrooms, yeast, and molds. Fungi cause infections such as thrush, cryptococcal meningitis, and PCP.

G6PD: Glucose-6-phosphate dehydrogenase. A protein normally found in red blood cells.

G6PD DEFICIENCY (GLUCOSE-6-PHOSPHATE DEHYDROGENASE DEFICIENCY): An insufficient amount of the enzyme G6PD in the body. People who are G6PD deficient are unable to take certain medications such as Dapsone because this enzyme is necessary to prevent these drugs from causing a harmful depletion of red blood cells.

GABA (gamma-amino-butyric acid): A chemical found in the brain that may act to antagonize dopamine activity in specific brain regions. In Huntington's disease, where dopamine activity may be excessive, there is evidence for a deficiency of GABA. In Parkinson's disease, where there is already underactivity of dopamine, some patients find they walk worse when they take a GABA-like drug. However, GABA-mimetic drugs such as baclofen (Lioresal) can be helpful in controlling some side effects such as the dystonias or dyskinesias seen in patients being treated chronically for Parkinson's disease.

GAMIUNE-N: Human serum globulin. Now in Phase I and II testing as an immunomodulator for ARC, AIDS and pediatric HIV infection.

GAMMA GLOBULIN (IgG): The portion of the plasma that contains antibodies.

GAMMA INTERFERON: This cytokine is produced by activated lymphocytes. Gamma Interferon enhances the antimicrobial functions of monocytes antimicorbialand macrophage cells. Recombinant gamma interferon, produced by Genetech, has been tested in patients with ARC, AIDS and KS with no apparent clinical benefit. Presently, it is thought that this medicine might be an antimicrobial therapy for MAI.

GANCICLOVIR (trade name CYTOVENE, DHPG): This drug has recently been approved

for AIDS patients with Cytomegalovirus (CMV) infection of the eye (CMV retinitis). The drug is still being studied to evaluate its benefits for other manifestations of CMV (colitis, encephalitis, etc.)

GANGLION: A mass of nervous tissue, composed principally of nerve-cell bodies, usually lying outside the central nervous system.

GASTROENTERITIS: Inflammation of the lining of the stomach and intestines.

GASTROINTESTINAL: Relating to the stomach and intestines.

GASTROINTESTINAL INTOLERANCE: Being unable to take a drug because it causes problems in the digestive system, such as stomach aches or diarrhea.

G-CSF: (Granulocyte colony stimulating factor) (trade name Neupogen) Appears to be slightly more effective in stimulating white blood cells than GM-CSF in Phase I and II trials.

GENE: A unit of DNA that carries the code for specific cell functions.

GENITAL: A sexual organ.

GENOME: The DNA code that comprises the complete genetic composition of an organism.

GENTAMICIN LIPOSOME INJECTION (TLC G-65): Recently granted orphan drug status by the FDA. Gentamicin sulfate is already approved to treat certain bacterial infections, but like many anitbiotics, it does not adequately reach the interior of human cells, where MAI resides. Liposomes naturally penetrate cell walls and are sometimes used to encapsulate and deliver a given drug to intracellular targets.

GIARDIASIS: A protozoan infection of Giardia lamblia with protracted, intermittent diarrhea; abdominal pain, distention, gas, fatigue and weight loss. Undigested fat may be present in the stools. Drugs are highly effective in clearing up this condition. (O.I.)

GLAMMA GLOBULINS: A type of immunoglobulin (see below) made by plasma cells, which is able to resist infection by viruses and bacteria.

GLAND: An organ that produces specialized chemicals, such as hormones, that are released into the blood to act as distant sites.

GLIA: These are the support cells of the central nervous system. While they do not carry out the brain's functions as the neurons do, they may play a role in maintaining the health of the neurons, and may be involved in a variety of neurologic disorders.

GLOBULINS: Simple proteins found in blood serums which contain various molecules central to immune system function.

GLOBUS PALLIDUS: An area of the brain adjacent to the striatum and related in function to the striatum. At one time surgical procedures were performed on the globus pallidus to try to relieve some of the symptoms of Parkinson disease. This surgery was of very limited benefit and is no longer being done. The term pallidum is also used to describe this area of the brain.

GLYCOSYLATION: The process of adding a form of glucose called glocosyl to a protein to form a glycoprotein.

GLYCYRRHIZIN: Glycyrrhizin sulfate, derived from licorice root. Has been observed in laboratory tests to inhibit HIV replication, interfere with virus-to-cell binding and cell-to-cell infection, suppress the clumping of infected cells and induce interferon activity. It also inactivated herpes simplex virus and varicella zoster virus, both of which can become serious opportunistic infections. Currently used in Japan to treat liver disease, it is being studied as a possible complementary therapy for a number of conditions involving liver dysfunction.

GM-CSF: (Granulocyte macrophage colony stimulating factor) - A hormone that stimulates growth of granulocytes and macrophages. GM-CSF has been synthesized by genetic engineering and is being tested in PWA as a means of alleviating the neutropenia caused by AZT and ganciclovir.

GP-41 See core protein.

GP-120: See envelope.

GRANULOCYTES: A cell type of the immune system filled with granules of toxic chemicals that enable them to digest microorganisms. Basophils, neutrophils, and eosonophils, are examples of granulocytes.

GRANULOCYTOPENIA: An abnormally low number of granulocytes in the circulating blood that can lead to increased risk of severe bacterial infection.

GROWTH FACTORS: A growth factor is responsible for regulating cell proliferation (rapid and repeated reproduction), function and differentiation. Different growth factors elicit different responses from different cell types, such as stimulating cell growth, enhancing cell survival, initiating cell migration and stimulating the secretion of tissue-specific hormones.

GUILLAIN BARR SYNDROME: An acute disease that produces bilateral weakness or paralysis, most commonly in the legs and feet.

H2 ANTAGONISTS: Medications used to treat longstanding acid indigestion and stomach ulcers.

HAIRY LEUKOPLAKIA: A whitish, slightly raised lesion that appears on the side of the cheeks, gums or tongue. Thought to be related to Epstein-Barr Virus infection. (O.I.)

HALF-LIFE: the time required for half the amount of a drug to be eliminated from the body.

HELPER-SUPPRESSOR RATIO: The ratio of helper T-cells to suppressor cells.

HELPER T CELLS: (T4,CD4) A subset of T cells that carry the T4 marker and are essential for turning on antibody production, activating cytotoxic T cells, and initiating other immune responses.

HEMATOCRIT: The percentage of packed red blood cells in a given volume of blood. Normal ranges: women 37-43%, men 43-49%.

HEMATOLOGIC NEOPLASMS: Tumors of the blood forming organs.

HEMATOTOXIC: Poisonous to the blood or blood producing bone marrow.

HEMOGLOBIN: The protein in red-blood cells responsible for oxygen transport. Normal hemoglobin values are 12-15 g/100 ml for women and 14-16.5 g/100 ml for men. These values can vary.

HEMOLYSIS: The rupture of red blood cells.

HEMOLYTIC ANEMIA: Anemia caused by excessive destruction or a shortened life span of red-blood cells. The body can't manufacture new cells fast enough to replace old cells.

HEMOPHILIA: An inherited disease that prevents the normal clotting of blood.

HEPATITIS: inflammation of the liver caused by one of several agents. Often accompanied by jaundice, enlarged liver, fever, fatigue, and nausea.

HEPATITIS B: a viral liver disease that can be acute or chronic and even life-threatening, particularly in people with poor immune resistance. Like HIV, the hepatitis B virus can be transmitted by sexual contact, contaminated needles or contaminated blood or blood products. Unlike HIV, it is also transmissible through close casual contact.

HERPES SIMPLEX VIRUS I (HSV I): A virus which causes cold sores or fever blisters on the mouth or around the eyes and can be transmitted to the genital region. The latent virus can be reactivated by stress, trauma, other infections or suppression of the immune system. In the eyes, called Herpes Zoster Opthalmicus. (O.I.)

HERPES SIMPLEX VIRUS II (HSV II): A virus causing painful sores of the anus or genitals which may lie dormant in nerve tissue and can be reactivated to produce the symptoms. HSV II may be transmitted to a neonate during birth from an infected mother. (O.I.)

HERPES VARICELLA ZOSTER VIRUS (HVZ): The varicella virus causes chicken pox in children and may reappear in adulthood as herpes zoster. Herpes zoster, also called shingles, consists of very painful blisters on the skin that follow nerve pathways. (O.I.)

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.

HHS: Branch of federal government: Department of Health and Human Services.

HIGH RISK BEHAVIOR: A term used to describe certain activities that increase the risk of transmitting the AIDS virus. These include anal or vaginal intercourse without a condom, oral-anal contact, semen or urine in the mouth, manual-anal penetration, sharing intravenous needles, intimate blood contact, and sharing of sex toys contaminated by body fluids. These behaviors are often referred to as "unsafe" activities.

HIGH RISK GROUPS: Those groups in which epidemiological evidence indicates there is an increased risk of contracting AIDS. High risk groups include gay and bisexual men, IV drug users, hemophiliacs, and the sexual partners of any in these groups. In prevention it is important to stress high risk behaviors as opposed to groups. It is not groups but behaviors that spread he AIDS virus (HIV).

HISTAMINE: A hormone/chemical transmitter involved in local immune responses, in regulating stomach acid production and in alergic reactions.

HISTOLOGICAL: Pertaining to the science of tissues, including their cellular composition and organization. It usually refers to the examination of biopsies with a microscope.

HISTOCOMPATIBILITY TESTING: A method of matching the self antigens (HLA) on the tissues of a transplant donor with those of a recipient. The closer the match, the better the chance that the transplant will not be rejected.

HISTOPLASMA CAPSULATUM: A type of fungus which may infiltrate the lungs of people with AIDS or be more widespread.

HISTOPLASMOSIS: A fungal infection caused by inhalation or ingestion of spores of Histoplasma capsulatum. It causes acute pneumonia, inflammation of the meninges, heart, peritoneum, adrenals, and all other organs of the body. Symptoms usually include fever, shortness of breath, cough, weight loss and physical exhaustion. (O.I.)

HIV positive (HIV+): Presence of the human immunodeficiency virus (HIV), the virus that causes AIDS, in the blood and confirmed by two successive ELISA tests and the Western Blot.

HIV-1: See Human Immunodeficiency Virus Type 1.

HIV-2: See Human Immunodeficiency Virus Type 2.

HIVAC-1e: This is an experimental substance prepared from the envelope protein of HIV. This is not a treatment for people with HIV infection. The protein is produced by genetic modification in the vaccinia virus. The purpose of this vaccine is to produce an increased immunity to AIDS in uninfected persons. The vaccine trial is considered the first step in testing vaccines which will stop the spread of AIDS.

HIVES: A skin reaction consisting of patchy, itchy, raised areas, usually triggered by allergic reactions to drugs or chemicals; occasionally caused by stress; sometimes referred to as urticaria.

HIVIG: A type of passive immunotherapy, a treatment in which plasma from HIV+ asymptomatic donors is processed to inactivate HIV and then infused into HIV-infected subjects. The plasma donors are selected for high levels of HIV neutralizing antibodies.

HODGKIN'S DISEASE: A progressive malignant cancer of the lymphatic system. Symptoms include lymphadenopathy, wasting, weakness, fever, itching, night sweats and anemia. This disease is treated with radiation and chemotherapy; newer combinations of anticancer drugs are being tried constantly with increasing success. Most patients can now be cured. (O.I.)

HOMOPHOBIA: Emotional negative bias, prejudice towards individuals who are homosexual.

HORMONAL: Pertaining to hormones, the chemical substances in the body that are involved in regulating and coordinating the activity of body tissue and organs; the hormones and the central nervous system represent the major governing systems of the body.

HORMONE: An active chemical substance formed in one part of the body and carried in the blood to another part of the body.

HOST: A cell or organism that supports the growth of a parasite or virus.

HPMPC: A drug that acts against CMV and herpes (not against HIV). Much of the research has tested it for herpes, but in AIDS the most important use may be for treating CMV (cytomegalovirus). In the laboratory, HPMPC is active against human CMV in very small concentrations. In vivo and in vitro studies have been completed; the next step is to complete preclinical tests, obtain and IND from the FDA, and begin clinical trials.

HTLV-III (Human T-Lymphotophic Virus Type III): See HIV-1

HUMAN HERPES VIRUS 6 (HHV 6): A new herpes virus recently discovered by Dr. Robert Gallo and associates at the National Cancer Institute. He has suggested that HHV 6 may play an important co factor role in the development of AIDS. HUMAN IMMUNODEFICIENCY VIRUS TYPE I (HIV-1): The retrovirus isolated and recognized as the etiologic agent of AIDS. HIV is classified as a lentivirus in a subgroup of the retroviruses.

HUMAN IMMUNODEFICIENCY VIRUS TYPE I (HIV-1): The retrovirus isolated and recognized as the etiologic agent of AIDS. HIV I is classified as a lentivirus in a subgroup of the retroviruses.

HUMAN IMMUNODEFICIENCY VIRUS TYPE II (HIV-2): A virus very similar to HIV-1 which has been found to cause immune suppression, primarily in Africa.

HUMAN LEUKOCYTE ANTIGENS (HLA): Protein markers of self used in histocompability testing.

HUMATIN: Trade name for paromomycin, an antibiotic used for the treatment of amebiasis and giardiasis; under study as treatment for cryptosporidiosis.

HUMORAL IMMUNITY: One of two fundamental but overlapping branches of the immune system (cell mediated is the other). The term 'humor' refers to the body fluids, primarily serum and lymph. Molecules of the humoral immune system are proteins collectively called immunogloblins, a single such molecule is called an antibody.

HUNTINGTON'S DISEASE: A degenerative disorder of the basal ganglia in which the striatum becomes shrunken. It is characterized by chronic, progressive motor disability including chorea and/or rigidity, plus mental deterioration terminating in dementia. Except for very rare mutations, the disease is inherited from an afflicted parent. (For more information this disorder, choose "Huntington" as your search term in the Rare Disease Database.)

HYBRIDOMA: A cell culture consisting of a clone of fused cells of different kinds, e.g., mouse myeloma cells and lymphocytes. A cell which produces antibody can be rendered "immortal" by fusing it with a tumor cell.

HYDROXYETHOXY METHYL PHENYLTHIOTHYMINE (HEPT): A potential antiviral drug shown to work in both T-cells and macrophages infected with HIV-1, but did not effect HIV-2 or other viruses.

HYPER-: A prefix meaning raised or increased; above.

HYPERICIN: A chemical substance that in laboratory studies inhibits HIV replication and spread from cell to cell, and protects mice from the lethal effects of HIV-like mouse viruses; found in low concentration in the St. John's Wort plant. Clinical trials of hypericin for treatment of HIV infection are about to begin with both a synthetic version and with a highly concentrated St. John's Wort extract.

HYPERPLASIA: Excessive growth of normal cells.

HYPERSENSITIVITY: A situation in which the body reacts with an exaggerated immune response to drugs or other substances.

HYPERTHERMIA: The treatment of disease by raising body temperature above normal.

HYPERURICEMIA: Excess of uric acid or urates in the blood; it is a prerequisite for the development of gout and may lead to renal disease.

HYPO-: A prefix meaning lowered or reduced; below.

HYPOGAMMAGLOBULINEMIA: Abnormally low levels of immunoglobulin.

HYPOKALEMIA: Abnormally low level of potassium in the blood; may result in abnormal heart rhythms, muscle weakness, or paralysis.

HYPOMAGNESEMIA: Abnormally low level of magnesium in the blood that can cause muscle weakness and fatigue.

HYPOXIA: Reduction of oxygen supply to tissue.

IDIOPATHIC: Without known cause. There are two major types of Parkinson's disease; the post-encephalitic variety associated with an attack of encephalitis, and the idiopathic variety, without apparent cause.

IDIOPATHIC THROMBOCYTOPENIC PURPURA (ITP): An autoimmune disease, common in people with AIDS, where the destruction of platelets (thromocytes) leads to an increased susceptibility to spontaneous bruising. (O.I.)

IDIOTYPES: The unique and characteristic parts of an antibody's variable region, which can themselves serve as antigens.

IDU: Injection/Intraveneous drug user(s).

IgA: An immunoglobulin found in body such as tears and saliva and in the respiratory and gastrointestinal tract to protect the body's entrances from infection.

IgD: An immunoglobulin that is poorly understood, but thought to participate in regulatory functions.

IgE: An immunoglobulin that participates in allergic reactions.

IgG: An immunoglobulin that circulates in the blood and enters tissues.

IgM: An immunoglobulin that primarily kills bacteria in the blood.

IM: Intramuscular; injected into the muscle.

IMIPRAMINE: This prescription drug is an antidepressant.

IMMUNE COMPLEX: Clusters formed when antigens and antibodies bind together.

IMMUNE DEFICIENCY: A breakdown or inability of certain parts of the immune system to function, thus making a person susceptible to certain diseases which they would not ordinarily develop.

IMMUNE MODULATORS: Substances that modify immune functions; the term generally used to identify substances that enhance immune functions. This includes two sub-groups: cytokines and "broad acting" immune modulators. Cytokines are hormones made by immune cells to influence other immune cells. "Broad acting" immune modulators are chemical transmitters/hormones in the body which regulate the immune system (i.e., endorphins), or act in a similar fashion.

IMMUNE RESPONSE: The activity of the immune system against foreign substances.

IMMUNE SYSTEM: The complex functions of the body that recognize foreign agents or substances, neutralize them, and recall the response later when confronted with the same challenge.

IMMUNITY: A natural or acquired resistance to a specific disease. Immunity may be partial or complete; long lasting or temporary.

IMMUNIZATION: To protect against disease by vaccination, usually with a weakened form of a pathogen that is unable to cause illness.

IMMUNOCOMPETENT: Capable of developing an immune response.

IMMUNOCOMPROMISED: Pertaining to reduced function of the body's immune system.

IMMUNOGENICITY: Having the properties of an antigen, a substance that produces a state of sensitivity and/or resistance to infection.

IMMUNOGLOBULIN (Ig): See antibodies. An antibody or protein which attacks invading organisms and allows the body to destroy them.

IMMUNOLOGIC: Relating to the study of immunity of diseases.

IMUNOLOGISTS: Physicians who specialize in disorders that involve the immune system and/or are treated by modifying the immune system, such as cancer, HIV infection, other infections, autoimmune diseases, management of organ transplants, etc.

IMMUNOMODULATING: A therapy that attempts to reconstruct or enhance a damaged immune system.

IMMUNOMODULATOR: Any substance that strengthens the immune system and helps the body fight off opportunistic infections or other diseases that attack people with HIV or AIDS.

IMMUNOMODULATION THERAPY: A therapy that attempts to reconstruct or enhance a damaged immune system. Examples of immunodulating therapy for AIDS include DNCB, isoprinosine and Imuthiol (DTC).

IMMUNOSTIMULANT (IMMUNOPOTENTIATORS): Any agent or substance that triggers or enhances the body's defenses; also called immunopotentiators.

IMMUNOSUPPRESSED: A state of the body in which the immune system defenses have been suppressed.

IMMUNOSUPPRESSION: Reduced function of the body's immune system.

IMMUNOTHERAPY: Treatment aimed at reconstituting an impaired immune system.

IMMUNOTOXIN: A monoclonal antibody linked to a toxic drug or a radioactive substance (e.g., CD4-Pseudonomas exotoxin).

IMREG: An experimental agent currently in Phase II testing as an immune modulator.

IMREG-1: A leukocyte derived immunomodulator which has been demonstrated to enhance the production of some immune system proteins in CD4+ cells from HIV- subjects. A trial in ARC patients is currently in development.

IMUTHIOL (diethyldithiocarbamate): Also known as DTC. An immune modulator developed in France; believed to cause the liver to produce a substance which causes the growth of T-cells. Results of a multicenter trial are mixed at best. Those who received the drug had slightly fewer OIs than those who received a placebo, however, those results only applied when patients were not using AZT of PCP prophylaxis.

IN VITRO: (Latin for "in glass") An artificial environment created outside a living organism, e.g., a test tube or culture plate, used in experimental research to study a disease of process.

IN VIVO: (Latin for "in life") Studies conducted within a living organism, e.g., animal or human studies.

INCLUSION/EXCLUSION CRITERIA: The medical or social reasons why a person may or may not be allowed to enter a trial. (For example, some trials may not allow women, another may exclude people with certain drug allergies).

INCREASED RETINAL VASCULAR TORTUOSITY: increased bending of the retinal vessels; seen in people with HIV, as well as with other systemic diseases in which the blood is thickened or the vitreous outflow of the eye is compromised.

INCUBATION PERIOD: The time interval between the initial exposure to infection and appearance of the first symptom or sign of disease.

IND or INVESTIGATIONAL NEW DRUG: Name given to an experimental drug after the FDA approves an application for testing in people.

IND status: Investigational new drug status. Certain drugs are available on a case by case basis through this mechanism.

INDICATION: Purpose for which a drug is intended; e.g. Pentamidine is indicated for PCP.

INDOMETHACIN: A nonsteroidal anti-inflammatory drug which provides symptomatic relief from fever and diarrhea, and both reduce synthesis of a certain prostaglandin (especially prostaglandin E2) which appears be excessive in persons with HIV and may make the disease worse.

INFECTION: The state or condition in which the body (or part of it) is invaded by an infectious agent which multiplies and produces an injurious effect (active infection).

INFECTIOUS: Capable of being transmitted by infection, with or without actual contact.

INFERENTIAL: Pertaining to inferences; something which is implied or inferred.

INFLAMMATORY BOWEL DISEASE (IBD): A disorder of the colon. Symptoms include "stomach" pain, constipation, and diarrhea. IBD can be one of two diseases with unknown causes: ulcerative colitis or Crohn's disease.

INFORMED CONSENT: Type of protection available to people considering entering a drug trial. Before entering the trial participants must sign a consent form that contains an explanation of a) why the research is being done; b) what researchers want to accomplish; c) what will be done during the trial and for how long; d) what risks are in the trial; e) what benefits can be expected from the trial; f) other treatments available; and g) the right to leave the trial at any time.

INFUSION: The process of giving a substance (medication, food supplements, etc.) to a patient by injecting it into the blood stream. This procedure can either be a one-time event or continued over many hours, days or even months.

INGUINAL: Relating to the groin.

INHIBITORS: In medicine, refers to drugs/chemicals/substances that inhibit or block a biological activity.

INSTITUTIONAL REVIEW BOARD (IRB): Every institution that conducts or supports biomedical or behavioral, research involving human subjects must, by federal regulation, have an IRB that initially approves and periodically reviews the research so as to protect the rights of human subjects.

INTEGRATION: The process by which the viral DNA of HIV enters the DNA of the T-helper cell. It can remain in the cell without reproducing until the T-helper cell is stimulated.

INTERACTION: Change in the body's response to one drug when another is taken. Interaction may increase the effect of one or both drugs, decrease the effect of one or both drugs, or cause toxicity.

INTERFERON: A family of 20-25 natural proteins (lymphokines) produced by the body in response to an infection. These substances "interfere" with cell infection. There are three main classes of interferon: alpha, beta, and gamma. They are produced by cells infected by almost any virus.

INTERLEUKIN: Any of several naturally occurring substances which are responsible for communication between immune system cells.

INTERLEUKIN 1 (IL-1): A molecule that is activated early in an immune system response; also called progen because it causes fever.

INTERLEUKIN 2 (IL-2): One of a family of molecules that control the growth and function of many types of lymphocytes. It is manufactured by Hoffman-LaRoche and Immunex under the trade name Leukomax, and by Cetus under the name Proleukin. A naturally-ocurring hormone in the body that governs the expression and re-activity of T-cells. A genetically-engineered version of IL-2 has been tested in combination with AZT and other antivirals. Results show no sustained T-helper cell increases nor any anti-HIV effect from IL-2; a modified version of IL-2 with a longer half-life is currently under study.

INTESTINAL MALABSORPTION: A condition in which the nutrients found in food are not absorbed by the body. It can lead to malnutrition and weight loss.

INTRACTABLE DISEASE: A disease which is unresponsive to treatment.

INTRALESIONAL: Injected directly into a lesion.

INTRATHECAL: Injected into the fluid surrounding the spinal cord.

INTRAVENOUS (IV): Within or into the veins. Intravenous drugs are injected directly into the veins.

INTRAVITREAL: Within the eye.

INTRON A: Interferon Alpha 2b; made by Schering-Plough, approved by the FDA as a treatment for Kaposi's Sarcoma.

IRIS: The colored disk behind the cornea and in front of the lens that regulates the amount of light entering the eye by adjusting the pupil.

ISCADOR: Iscador is the brand name of an extract of European mistletoe (Viscum album), a common plant. In Western Europe it has been used as a cancer treatment for over 60 years. Iscador works as an anticancer agent by directly destroying cancer cells and by enhancing the immune system.

ISOPORIASIS (Coccidiosis): A sporozoan parasitic infection which is usually asymptomatic but may result in severe diarrhea. (O.I.)

ISOLATE: Different strains of HIV.

ITP: (idiopathic thrombocytopenic purpura) A condition in which the body produces antibodies against its own blood clotting cells, platelets.

ITRACONAZOLE (ITR): An antifungal, investigational drug being studied for a number of AIDS-related fungal infections. Its toxicity profile resembles fluconazole. ITR's most promising use is as a maintenance therapy against the fungal infections Histoplasmosis capsulatum and cryptococcal meningitis. I.V. PENTAMIDINE: A drug frequently used as the second-line treatment (after TMP-SMX) for PCP. Side effects may include pancreatitis.

INTRAVENOUS IMMUNOGLOBULIN (IVIG, trade name GAMIMUNE N): This product is a sterile solution of gamma globulins (proteins) containing antibodies normally present in adult blood. Gamma globulin (Gamimune N, trade name) is a prescription biological therapy for non-AIDS immunodeficiency syndrome and for non AIDS-related Idiopathic Thromocytopenic Purpura (ITP). IVIG is experimental in symptomatic HIV-infected children. IVIG is experimental in adults with AIDS who have decreased platelet counts.

IVDU: Intravenous drug user(s).

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): Masses of small blood vessels which grow rapidly. Kaposi's Sarcoma was initially thought to be a tumor of small blood vessels. Usually appears as pink to purple, painless spots on the skin but may also occur internally in addition to or independent of the skin lesions. Originally seen in elderly men or in equatorial Africans in a slow growing form. It can be accompanied by fever, enlarged lymph nodes and gastrointestinal problems. (O.I.)

KARNOFSKY SCORE: A subjective score assigned by a physician describing a patient's ability to function and measured by the performance of common tasks. 90-100% is "normal, no complaints".

KETOCONAZOLE (trade name NIZORIL): A prescription drug supplied in tablets and liquid suspension used for the treatment of systemic (throughout the body) fungal infections: candidiasis, chronic mucocutaneous candidiasis, oral thrush, candiduria, blastomycosis, coccidioidomycosis, histoplasmosis, chromomycosis, and paracoccidioidomycsis. kg (kilogram): A measure of weight equal to 2.2046 pounds.

KILLER CELLS: A class of immune system cells that function to kill cancer and virus-infected cells; also called "Natural Killer" cells.

KILLER T CELL: See cytotoxic T lymphocyte.

KUPFFER CELLS: Specialized macrophages in the liver.

KURU: A chronic, progressive, fatal nervous system disorder caused by a slow virus. It is found only among the Fore and neighboring peoples of New Guinea and is thought to be associated with cannibalism. Symptoms include failure of muscular coordination, shivering tremors, slurring of speech, and uncontrollable eye motions. Included here as another neurological virus.

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.

LAK CELLS: Lymphocytes transformed in the laboratory into lymphokine activated killer cells, which attack tumor cells.

LANGERHANS CELLS: Dendrite cells in the skin that pick up antigen and transport it to the lymph nodes.

LAS (Lymphadenopathy Syndrome): A chronic enlargement of lymph nodes (glands), often associated with HIV infection.

LATENCY: The period when an organism is in the body and not producing any ill effects.

LAV: (Lymphadenopathy Associated Virus). See HIV.

LAVAGE: Washing.

LECTINS: A substance derived from plants that produces action resembling immunological reactions. Lectins are commonly used as mitogens.

LECITHIN (Phosphatidylcholine): Like choline, this substance may be a dietary precursor to acetylcholine and may be useful in the conditions mentioned above, where choline is being studied.

LEGIONNAIRES' DISEASE: A disease caused by the bacteria Legionella pneumophila. It is characterized by high fever, gastrointestinal pain, headache, and pneumonia. There may also be involvement of the kidneys, liver and nervous system. (O.I.)

LENTINAN: An experimental polysaccharide (a sugar product) given by IV administration. The drug is obtained from edible mushrooms. It acts as a non-specific immunomodulator which may augment the patient's immune response. It is used as a cancer treatment in Japan. An extract from the shiitake mushroom that has been used in Japan as an adjunct to cancer therapy. Phase I trials of lentinan in the U.S. showed no effectiveness as a treatment for HIV infection at the doses studied. A Phase I/II open label efficacy trial of lentinan plus AZT is currently under way at UCSF.

LENTIVIRUS: A sub-family of retroviruses that is cytopathic and causes chronic diseases.

LESION: Any pathological or traumatic discontinuity of tissue, which may cause a loss of function (of the affected or surrounding tissue).

LEU19(CD56): A T-cell receptor that is a marker for a subset of killer cells called "lymphokine-activated killer cells" (LAK cells). These cells kill virus- infected cells. Indication of increases in CD56 cells may serve as a mechanism by which some immune-modulating drugs reduce the body's HIV burden, and/or reduce HIV-related damage to T-helper cells.

LEUCOVORIN CALCIUM: A calcium salt of folic acid (a member of the vitamin B complex). Leucovorin is used to treat severe anemia. 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.

LEUKOCYTES: All white blood cells. They play a major role in fighting disease. Lymphocytes are one subclass of Leukocytes. The two types of white blood cells commonly associated with AIDS are T-cells and B-cells.

LEUKOPENIA: A lower than normal level of leukocytes (white blood cells) in the blood.

LEVAMISOLE: Immunostimulant, available on a compassionate use basis as therapy for people with colon cancer, but is not being studied for AIDS. Nevertheless many PWAs use Levamisole as an immunomodulator and report some benefit in the number of reduced minor infections such as colds and sinus problems. An immune- modulating drug that is FDA-approved for the treatment of cancer of the colon and rectum.

LEVODOPA (L-dopa): A natural compound found in the body and brain that is converted into dopamine by special enzymes. When nerve cells die and no longer produce dopamine, levodopa may be given as a medication which is absorbed from the stomach and intestines into the blood stream and eventually passes to the brain where the special enzymes can convert it into dopamine.

LEVODOPA-INDUCED DYSKINESIAS: Abnormal, involuntary movements which appear after patients have been treated for prolonged periods with dopaminergic agents. At early stages of the disorder these can often be alleviated by a reduction in the amount of drug taken. This side effect can be alleviated by a reduction in the amount of drug taken. This side effect differs from the "on-off" phenomenon and end-of-dose akinesia (see ON-OFF PHENOMENON below).

LIPIDS: Substances extracted from animal or vegetable cells by "fat" solvents.

LIPOSYN III-2%: A lipid mixture containing egg lipids (phosphatides) which is administered intravenously. Other stimulating substances are also present. Lyposyn III-2% has been used in AIDS patients as a parenteral (intravenous) nutritional program with encouraging effects. Lipid mixtures of this type have shown anti-HIV properties in vitro, e.g. AL-721. Intravenously administered Lyposyn III-2% may show anti-HIV properties in HIV-infected patients. In clinical trials, orally administered AL-721 did not slow HIV in ARC patients and did not show changes in T-cells or p24 antigen levels.

LIPOSYN II-20% (manufacturer Abbott Laboratories): A lipid mixture analog of Lyposyn III-2% available in hospitals throughout the nation. A fat emulsion product given by intravenous administration. The product is used to supply fatty and other nutrients to severely undernourished patients.

LISTERIOSIS: In humans, a disease characterized by upper respiratory infection, angina, conjunctivitis, inflammation of the lymph nodes, and septicemia (blood poisoning.) The active agent is Listeria monocytogenes. (O.I.)

LITHIUM CARBONATE: Lithium salts have been used extensively in the treatment of manic depressive illness. Non-AIDS patients treated with lithium carbonate often increases granulocytes. lithium carbonate is being studied for the treatment of AZT-related neutropenia.

LUMBAR PUNCTURE (spinal tap): A test in which cerebrospinal fluid (CSF) is withdrawn and analyzed. A small opening in the spinal column made by a needle, to remove spinal fluid, or to inject anesthesia or medicine need not be painful if enough local anesthetic is used. For a day following the procedure, raising the head and spine can cause spinal fluid to leak out resulting in severe headaches. Usually it is performed if there is suspicion of an infectious disease of the brain or nervous system such as encephalitis or meningitis.

LYMPH: A transparent, slightly yellow fluid that carries lymphocytes. Lymph is derived from tissue fluids collected from all parts of the body and is returned to the blood via lymphatic vessels.

LYMPH GLANDS: Glands in the lymph vessels throughout the body that trap foreign and infectious matter and protect the bloodstream from infection.

LYMPH NODES: Small bean-sized organs of the immune system, distributed widely throughout the body. Lymph fluid is filtered through the lymph nodes in which all types of lymphocytes take up temporary residence. Antigens which enter the body find their way into lymph or blood and are filtered out by lymph nodes or the spleen respectively, for attack by the immune system.

LYMPHADENOPATHY (seen from Chronic Lymphadenopathy Syndrome (CLS); GENERALIZED LYMPHADENOPATHY SYNDROME (GLS); LYMPHADENOPATHY ASSOCIATED SYNDROME (LAS); and PROGRESSIVE GENERALIZED LYMPHADENOPATHY (PGL): Swollen, firm and possibly tender lymph nodes. The cause may range from a temporary infection such as the flu, HIV, mononucleosis, to lymphoma(cancer of the lymph nodes). PGL (also called AIDS-related complex) in HIV infection is a condition in which lymph nodes are chronically swollen in at least two areas of the body for three months or more. Enlarged spleens also occur in about one third of people with PGL.

LYMPHATIC VESSELS: A body-wide network of channels, similar to the blood vessels, which transport lymph to the immune organs and into the bloodstream.

LYMPHOCYTE: A type of white blood cell. T-helper cells are one type of lymphocyte.

LYMPHOCYTIC INTERSTITIAL PNEUMONIA (LIP): A type of pneumonia that affects 35 to 40% of children with AIDS. Children with HIV who have LIP are diagnosed as having AIDS.

LYMPHOCYTES: A type of white-blood cell, comprising between 20 and 50 percent of white-blood cells in an adult. Lymphocytes are produced in the lymphoid tissues of the body. The B lymphocytes produce antibodies that are released into the bloodstream. The T lymphocytes, on the other hand, carry antibodies on their own surface and produce cellular immunity. The AIDS virus attacks certain kinds of T lymphocytes--the helper T cells--and this leads to severe immune deficiency.

LYMPHOID TISSUE: Refers to large well defined collections of different types of lymphocytes that are found in many parts of the body. Lymph nodes and spleen consist almost entirely of lymphoid tissue. It is also found throughout the body, particularly in the small intestine.

LYMPHOKINES: Powerful substances, produced and released into the bloodstream by T lymphocytes. These molecules help direct and regulate the immune response.

LYMPHOKINE ACTIVATED KILLER CELLS (LAK): Lymphocytes transformed in the laboratory into killer cells which attack tumor cells.

LYMPHOMA: A group of malignant diseases of the lymphoid tissue. These include Hodgkin's disease and non-Hodgkin's lymphoma. The usual symptoms include persistent lymph-node swelling, weight loss, and sometimes fever. The type of treatment depends on the appearance of the lymphoma under the microscope as well as the extent of the spread of the lymphoma. Treatment can involve either radiotherapy or chemotherapy, or a combination of both. In most cases of Hodgkin's disease and about 50 percent of non-Hodgkin's lymphoma, treatment can result in a cure. (O.I.)

LYSIS: Rupture and destruction of a cell.

MACROLIDE: A group of antibiotic drugs.

MACROPHAGE: Certain phagocytes known as macrophages act as identifiers of foreign material within the body engulfing them and then expressing on their own surfaces the specific chemical markers that can be recognized by other cells of the immune system. The macrophage may be a reservoir for HIV. A large scavenger cell that ingests degenerated cells, blood tissue and foreign particles. Macrophages exist in large numbers throughout the body, and are key to the development of immunity to a variety of organisms.

MACULA: the pigmented central area, or "yellow spot," of the retina devoid of blood vessels; it is the most sensitive area of the retina and is responsible for its nourishment.

MAGNETIC RESONANCE IMAGING (MRI): A non-invasive diagnostic technique that can provide information on the form and function of internal tissue and organs of the body.

MAC: See mycobacterium avium intercellular.

MAI: See Mycobacterium avium intercellular.

MAI BACILLEMIA: Having MAI organisms floating freely in the blood.

MAINTENANCE THERAPY: Use of a treatment or treatments to maintain a desired effect that has already been achieved.

MAJOR HISTOCOMPATIBILITY COMPLEX (MHC): A group of genes that controls aspects of the immune response. The products of these genes, the histocompatibility antigens, are present on every cell of the body and serve as markers to distinguish self from non-self cells.

MALABSORPTION SYNDROME: Decreased intestinal absorption resulting in loss of appetite, muscle pain and weight loss.

MALAISE: A generalized nonspecific feeling of discomfort.

MALIGNANCY: A neoplasm or tumor replicating out of control and invading tissue and causing damage to that tissue.

MARINOL: A synthetic form of tetrahydrocannabinol, the active ingredient in marijuana. Unimed, the manufacturer, has been granted orphan drug status for Marinol as a treatment for stimulating appetite and combatting weight loss in persons with AIDS.

MAST CELL: A granulocyte found in tissue. The contents of the mast cells, along with those of basophils, are responsible for the symptoms of allergy.

mBACOD: ACTG Trial No. 074 (LYMPH002) tests a chemotherapy medicine, mBACOD, in patients with AIDS-related lymphoma. the medicine mBACOD is a combination chemotherapy, which consists of six medicines: methotrexate, Adriamycin (doxorubicin), bleomycin, cyclophosphamide, Oncovin (vincristine), and dexamethasone. The action of these anti-cancer drugs is described in the Physician's Desk Reference (PDR). GM-CSF is given to patients along with mBACOD to counteract the toxic side effects on white blood cells.

MEAN CORPUSCULAR VOLUME (MCV): The average volume of erythrocytes, conventionally expressed in cubic micrometers per red blood cell.

MECHANICAL VENTILATION: The use of a device called a ventilator to keep a person breathing when that person is unable to breath on his or her own.

MEGACE (megesterol a