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Published in the Bulletin of Experimental Treatments for AIDS Winter 2002 issue, by the San Francisco AIDS Foundation.
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GlossaryA | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X-ZAACUTE: rapid in onset, aggressive; short-term initial stage of a disease. Contrast with chronic. ALLERGEN: a substance that induces allergy. ANALGESIC: a drug or therapy that reduces perception of or sensibility to pain. ANESTHETIC: an agent that controls pain. ANTENATAL: the period of time before birth. ANTIBODY (AB, IMMUNOGLOBULIN, IG): a protein secreted by activated plasma cells, which evolve from B cells. Antibodies are present throughout the blood and tissues; they are produced in response to stimulation by foreign antigens as part of the body’s defense against disease. Specific antibodies bind to and act upon specific antigens; the antigen/antibody reaction forms the basis of humoral (TH2) immunity. ANTIDEPRESSANT: a psychotropic agent that elevates the mood and prevents or alleviates psychological depression. Antidepressant drugs may be used as an adjuvant analgesic to relieve the pain of peripheral neuropathy. Heterocyclic and tricyclic classifications refer to antidepressants with specific chemical structures. Other classes of antidepressants include MAO inhibitors and selective serotonin reuptake inhibitors (e.g., Prozac). ANTIGEN: any agent or substance that stimulates an immune response. Antigens are often foreign microorganisms such as bacteria or viruses, or the substances they produce. ANTIRETROVIRAL: an agent (e.g., AZT, ritonavir, efavirenz) that suppresses the activity or replication of retroviruses such as HIV by interfering with various stages of the virus’ life cycle. ARRHYTHMIA: loss of normal rhythm, especially irregularities of the heartbeat. ARTHRODESIS: surgical immobilization of a joint; joint fusion. ARTHROPLASTY: surgical repair of a joint. ASYMPTOMATIC: not feeling or showing outward signs of a disease. AUTOIMMUNE RESPONSE (AUTOIMMUNITY): a condition in which an individual’s immune system fails to recognize its own biochemical markers as being part of the “self” and attacks body tissues as if they were foreign matter, possibly leading to autoimmune diseases such as lupus or rheumatoid arthritis. AXON: the extension of a neuron that conducts neuronal impulses to and from muscles, tissues, and organs. See neuron. BBASELINE: an initial or known value (e.g., CD4 cell count, HIV viral load) against which later measurements can be compared. BIOPSY: the removal of a small sample of cells or tissue for microscopic examination and/or culture. BONE MARROW: the soft, spongy tissue in the interior of certain bones (e.g., the long bones of the limbs). Bone marrow contains stem cells and is the site of blood cell production. CCESAREAN SECTION (C SECTION, CESAREAN DELIVERY): a delivery procedure that involves making an incision through the abdominal wall to permit the removal of an infant from the uterus. CHEMOTHERAPY: the use of chemicals or drugs to treat disease; the term typically is used to refer to cancer treatment. CHRONIC: less intense, slow, persisting over a long period. Contrast with acute. COHORT: a group of individuals in a study who share a demographic, clinical, or other statistical characteristic (e.g., age, study site). CORTICOSTEROID: one of a group of steroid hormones (e.g., prednisone, cortisone, aldosterone) produced by the cortex of the adrenal gland or manufactured synthetically. Corticosteroids have anti-inflammatory and immunosuppressive properties and are used to treat a variety of conditions. CORTISOL: a steroid hormone secreted by the adrenal cortex as part of the body’s response to stress. Cortisol promotes the breakdown of body tissues to provide energy and raw materials; high cortisol levels are associated with reduced immune function. Synthetic cortisol (hydrocortisone) is used to reduce inflammation and lessen allergic reactions. CUSHING’S SYNDROME: a disorder caused by excessive secretion of the adrenal gland hormone cortisol. The syndrome is characterized by accumulation of fat around the abdomen. CYTOKINE: an intercellular hormone or chemical messenger protein (e.g., tumor necrosis factor, interleukin) released by white blood cells (e.g., macrophages, T cells). Cytokines facilitate communication among immune system cells and between immune system cells and the rest of the body. CYTOMEGALOVIRUS (CMV): a herpes virus that occurs in healthy individuals without causing symptoms. In immunocompromised individuals (usually with fewer than 50 CD4 cells/mm3), CMV may cause serious illness including retinitis (inflammation of the retina), pneumonia, colitis (inflammation of the large bowel), and encephalitis (inflammation of the brain). CMV infection in a pregnant woman may lead to congenital abnormalities in the newborn. CMV may be treated with ganciclovir, foscarnet, or cidofovir. DDEGENERATION: progressive deterioration of a tissue or organ leading to structural or functional impairment. DEMYELINATION: the destruction or loss of the myelin (a fatty substance) sheath that surrounds and insulates the axons of nerve cells. The myelin sheath is necessary for the proper conduction of neural impulses. DISLOCATION: the displacement of any part, especially of a bone. DYSFUNCTION: lack or loss of normal function. EEFFECTOR: a molecule, chemical, or structure that regulates a pathway (course followed by a body process) by increasing or decreasing the pathway’s reaction rate. ELECTROPHYSIOLOGICAL: electrical phenomena associated with a physiological process (i.e., the function of a bodily part). ENZYME: a protein that induces or accelerates a chemical reaction. ERADICATION: the complete elimination of an organism (e.g., HIV) from the body, including the blood and reservoir tissue sites. ETIOLOGY: the cause or causes of a disease; the study of causes of disease. GGANGLION: a general term for a group of nerve cell bodies located outside of the central nervous system, and occasionally applied to certain cell groups within the brain or spinal cord (e.g., basal ganglia). GANGLIONITIS: inflammation of the ganglion. GASTROINTESTINAL: pertaining to the stomach and intestines. GLUCOSE (BLOOD SUGAR): a form of sugar that is the body’s primary fuel; glucose broken down from food can be converted into energy or stored. Abnormally low or high levels of glucose in the blood often indicate metabolic disturbances (e.g., diabetes). HHAART: highly active antiretroviral therapy, a term for potent combination anti-HIV treatment that usually includes a protease inhibitor. HERPESVIRUS: a group of viruses that includes herpes simplex virus type 1 (HSV-1) and 2 (HSV-2), varicella-zoster virus (VZV), Epstein-Barr virus (EBV), cytomegalovirus (CMV), human herpesvirus types 6 and 7 (HHV-6, HHV-7), and Kaposi’s sarcoma-associated herpesvirus (HHV-8). Herpesviruses may act as opportunistic pathogens and/or cofactors in HIV pathogenesis (disease development). HORIZONTAL TRANSMISSION: contagion or spread of an infectious disease from one individual to another within a population. Contrast with perinatal transmission. HYPERSENSITIVITY: abnormal sensitivity; an exaggerated immune response to a substance such as an antigen or drug. IIMMUNODEFICIENCY: the inability of the immune system to work properly, resulting in susceptibility to disease. Immunodeficiency may be either congenital (present from birth) or acquired. HIV leads to immunodeficiency by attacking T cells. IMMUNOPHILIN: a generic term for an intracellular protein that binds to immunosuppressive drugs. IMMUNOSUPPRESSION: reduced function of the immune system; a state in which the immune system defenses have been suppressed, damaged, or weakened. IN UTERO: in the uterus; typically refers to events that occur in the womb before birth. INCIDENCE (INCIDENCE RATE): the number of new cases of a disease or condition in a specific population during a given period of time. The incidence rate is determined by dividing the number of new cases by the total population. Contrast with prevalence. INDUCTION THERAPY: a short course of therapy used to control the active spread of a disease and usually requiring higher and/or more frequent dosing than required after the disease is initially brought under control. Contrast with maintenance therapy. INFLAMMATION: the body’s response to tissue injury or infection, which typically includes increased vessel dilation and permeability, resulting in redness, swelling, heat, and pain. INTRAVENOUS (IV): injected directly into a vein. LLIPID: a fat. LIPOATROPHY: wasting of body fat. LIPOCYTE: a fat cell. LIPODYSTROPHY: abnormal body fat distribution, which may include wasting and localized fat accumulation. Also refers to a broader, poorly defined syndrome that may include altered fat metabolism, insulin resistance, and other manifestations. MMACROPHAGE: a large scavenger white blood cell that ingests and processes degenerated cells and foreign invaders. Macrophages secrete messenger proteins (monokines) involved in a variety of immune system responses. Macrophages are derived from monocytes that leave the blood to migrate into the tissues. Specialized macrophages protect the skin, lungs (alveolar macrophages), brain (microglia), liver (Kupffer cells), and other tissues. Long-lived macrophages can harbor large quantities of HIV and may act as viral reservoirs. MAGNETIC RESONANCE IMAGING (MRI): a sensitive, noninvasive method for viewing soft tissues of the body using a strong magnetic field. MAINTENANCE THERAPY (SECONDARY PROPHYLAXIS): preventive or suppressive therapy that follows successful initial treatment of an illness. Maintenance therapy generally continues for the lifetime of the individual to prevent disease recurrence. Contrast with induction therapy. MASTITIS: inflammation of the breast, usually caused by infection. MEAN: a statistical measurement of the central tendency, or average, of a set of values. Contrast with median. MEDIAN: the number within a series that is preceded and followed by an equal number of values. Also, the middle value in a distribution, on either side of which lie an equal number of values. Contrast with mean. METHADONE: an oral opioid drug used for pain therapy and to treat opiate (e.g., heroin) addiction. Methadone maintenance therapy is used to prevent withdrawal symptoms by administering a small dose of methadone on a regular (e.g., daily) basis. MONOTHERAPY: use of a single drug or other therapy. MYELIN: a white fatty substance that forms a sheath around the axons of certain neurons and provides insulation necessary for proper neural transmission. MYOPATHY: inflammation or degeneration of the muscles, which may cause pain or weakness. NNARCOTIC: see opiate. NEURITIS: inflammation of a nerve, or a condition resulting in pain and tenderness of the nerves. NEURON (NERVE CELL): a cell that conducts electrical neural impulses from one part of the body to another. Neurons are made up of dendrites (branch-like fibers that receive impulses) and axons (fibers that transmit impulses), and communicate with other neurons and effector organs at junctures called synapses. NEUROTOXIC NEUROPATHY: a form of neuropathy that may be caused by the side effects associated with many of the antiretroviral drugs used to treat HIV disease. NON-NUCLEOSIDE REVERSE TRANSCRIPTASE INHIBITOR (NNRTI): a drug (e.g., nevirapine, delavirdine, efavirenz) that binds with and inhibits the action of the HIV reverse transcriptase enzyme, thus blocking viral transcription and replication. OOFF-LABEL: use of an FDA-approved drug for an indication other than that for which it was approved. OPIATE (OPIOID, NARCOTIC): a class of drugs (e.g., heroin, codeine, methadone) that are derived from the opium poppy plant, contain opium, or are produced synthetically and have opium-like effects. Opioid drugs relieve pain, dull the senses, and induce sleep. OPPORTUNISTIC ILLNESS (OPPORTUNISTIC INFECTION, OI): a disease caused by a microorganism that does not normally cause illness in a person with a healthy immune system, but that may cause serious disease when the immune system is weakened. Common OIs in HIV positive people include Pneumocystis carinii pneumonia (PCP), Mycobacterium avium complex (MAC), and cytomegalovirus (CMV) infection. OSTEOBLAST: a bone-forming cell. OSTEOCLAST: a large cell involved in the absorption and removal of bone tissue. OSTEOPENIA: a reduction in bone volume to subnormal levels. OSTEOPOROSIS: atrophy of the bone tissue; a loss of calcium from the bones. Osteoporosis is influenced by hormone levels and may be ameliorated by adequate calcium intake. PPARASTHESIA: an abnormal sensation such as burning, prickling, tickling, or tingling. PASTEURIZATION: partial sterilization of a substance (especially a liquid) using heat to destroy harmful organisms without inducing major chemical alteration of the substance. PATHOLOGY ( adjective PATHOLOGIC): and how the body is affected. PERINATAL TRANSMISSION (VERTICAL TRANSMISSION): the conveyance of a pathogen such as HIV from a mother to a fetus or newborn. Vertical transmission may occur in utero (in the womb), intrapartum (during birth), or postpartum (via breast-feeding). Contrast with horizontal transmission. PERIPHERAL: located at the periphery or away from the center. PERIPHERAL NEUROPATHY: damage to the peripheral nerves, usually involving the feet and hands, and sometimes the legs, arms, and face. Symptoms may include numbness, tingling or burning sensations, pain, abnormal reflexes, weakness, and partial paralysis. Peripheral neuropathy is a side effect of many drugs (e.g., ddC, ddI, d4T). PERSON-YEAR: a value determined by multiplying the number of persons by the number of years. For example, one person followed for ten years equals ten person-years; ten persons followed for one year also equals ten person-years. PLACEBO: an inert, inactive substance; a “sugar pill.” Experimental therapies are compared with a placebo in many clinical trials. PNEUMOCYSTIS CARINII PNEUMONIA (PCP): a life-threatening opportunistic type of pneumonia believed to be caused by a protozoan. PCP is a common infection that can cause severe illness in immunocompromised people (especially those with fewer than 200 CD4 cells/ mm3). Symptoms include dry cough, fever, chest tightness, and shortness of breath. Pneumocystis carinii can also infect other parts of the body. First-line treatment and primary prophylaxis is TMP-SMX (Bactrim, Septra); other treatments and prophylaxes include dapsone, pentamidine, and atovaquone. POLYMERASE CHAIN REACTION (PCR) ASSAY: a highly sensitive test that can detect small amounts of DNA or RNA (genetic material) in a blood or tissue sample using an amplification technique that multiplies the existing DNA/RNA so that it can be detected more easily. PCR assays are used to determine viral loads in persons infected with HIV. POLYRADICULOPATHY: inflammation of nerve roots near the spinal cord. PREVALENCE (PREVALENCE RATE): the proportion of individuals with a disease or condition in a specific population during a given time. The prevalence rate is determined by dividing the number of people with the condition by the total population. Contrast with incidence. PROGRESSION: advancement of a disease. PROPHYLAXIS: a therapy that helps to prevent a disease or condition before it occurs (primary prophylaxis) or recurs (secondary prophylaxis). PROPRIOCEPTION: the perception of movement and position in space. PROTEASE INHIBITOR (PI): a drug (e.g., saquinavir, ritonavir, indinavir) that blocks the action of the HIV protease enzyme, thereby preventing viral replication. PROTOCOL: a plan that states the specifics of a clinical trial, such as the hypothesis to be tested, drug(s) to be used, method(s) of administration, length of the trial, endpoints to be used, and characteristics of participants (e.g., inclusion/exclusion criteria). PSYCHOTROPIC: an agent (e.g., thorazine) that affects psychological or mental functioning or behavior. RRADIOGRAPH: a picture taken with X-rays, for example for diagnosis. RANDOMIZED TRIAL: an experiment in which subjects with particular characteristics are assigned by chance to different treatment or control arms. Randomization is done to cancel out the influence of factors that are not under study. With successful randomization, the chance of one individual’s being placed in a given study arm is independent of the placement of others, and the only differences between the groups are those intended by the experimenter (e.g., different drugs taken). RECEPTOR: a specific binding site on a cell’s surface or interior. When chemical messengers bind to receptors, various cellular functions are activated or inhibited. Many drugs exert their effects by binding to receptors and altering normal cellular communication. Viruses enter cells by fusing with receptors on the cell surface. RESORPTION: the process of dissolving and assimilating a substance such as bone tissue. SSEROCONVERSION: the development of antibodies directed against an antigen; the change in a person’s antibody status from negative to positive. Vaccine-induced seroconversion does not indicate an infection. SERONEGATIVE: having a blood test result that does not indicate infection with a microorganism (e.g., HIV), either by the presence of antibodies or antigen. SEROPOSITIVE: having a blood test result that indicates infection with a microorganism (e.g., HIV). A test may either detect antibodies to an organism (antibody positive), or detect the organism itself or its proteins (antigen positive). SEROSTATUS: the presence or absence of an organism in the blood. Serostatus may be measured by the presence of antibodies against an organism (antibody status) or by the presence of the organism itself (antigen status). See seronegative and seropositive. SPINAL CORD: the cord of nervous tissue that extends from the brain lengthwise along the back in the vertebral canal, carries impulses to and from the brain, and serves as a center for initiating and coordinating many reflexes. STEROID: one of a family of substances that share a similar chemical structure, including certain hormones (e.g., testosterone) and various drugs. Some steroid drugs are used to lessen inflammatory reactions. SUBCLINICAL: low-grade and asymptomatic. SURROGATE MARKER: a marker or sign that can serve in place of a clinical endpoint such as disease progression or death. Surrogate markers for HIV disease may be virologic (e.g., viral load), immunologic (e.g., CD4 cell count), or clinical (e.g., weight loss). SYMPTOMATIC: showing outward signs of a disease. TT LYMPHOCYTE (T CELL): a type of white blood cell that matures in the thymus and carries out the cellmediated immune response. There are three major types of T lymphocytes: helper (CD4) T cells, suppressor (CD8) T cells, and killer (CD8) T cells (cytotoxic T lymphocytes or CTLs). TARSAL TUNNEL SYNDROME: inflammation of the tibial nerve. Symptoms may include pain, numbness, burning, and electrical sensations along the nerve, which includes the inside of the ankle, heel, arch, and bottom of the foot. THYROID GLAND: an organ at the base of the neck that produces thyroxin and other hormones. TOXIC: the quality of being poisonous or harmful; often used to refer to side effects of drugs. TRANSCUTANEOUS (TRANSDERMAL): able to be absorbed by or to pass through intact skin; administered through the skin. TRICYCLIC ANTIDEPRESSANT: see antidepressant. TRIGLYCERIDE: a combination of glycerol and fatty acid that circulates in the blood. VVARICELLA-ZOSTER VIRUS (VZV, HUMAN HERPESVIRUS 3): a herpesvirus that initially causes chickenpox (varicella), usually in children. VZV may lie dormant within the nerves and later reactivate to cause herpes zoster (shingles), especially in immunosuppressed individuals. VASCULITIS: inflammation of the blood or lymph vessels. VIREMIA: the presence of virus in the blood. VISCOSITY: thickness of a fluid or semifluid; resistance to flow. VISCOUS: not able to flow freely (of fluid); having a consistency similar to honey or syrup. WWASTING SYNDROME: a condition characterized by atrophy of lean body mass and involuntary weight loss of more than 10% of normal body weight. Other symptoms may include chronic diarrhea, fatigue, weakness, and fever. Death typically occurs when body weight falls to one-third of ideal weight, or when body cell mass decreases by 50%. Page last updated 21 March 2002 |
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