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ACQUIRED IMMUNODEFICIENCY SYNDROME (AIDS):
The most severe manifestation of infection with the human immunodeficiency virus (HIV). The Centers for Disease Control and Prevention list numerous opportunistic infections and neoplasms (cancers) which, in the presence of HIV infection, constitute an AIDS diagnosis. In addition, a CD4+ T-cell count below 200/mm3 in the presence of HIV infection constitutes an AIDS diagnosis. The period between infection with HIV and the onset of AIDS averages 10 years in the United States. People with AIDS often suffer infections of the lungs, brain, eyes and other organs, and frequently suffer debilitating weight loss, diarrhea and a type of cancer called Kaposi's sarcoma. Even with treatment, most people with AIDS die within two years of developing infections or cancers that take advantage of their weakened immune systems. See also CD4 (T4) or CD4+ Cells; Diarrhea; HIV Disease; Kaposi's Sarcoma; Opportunistic Infection; Wasting Syndrome.
A chronic disease caused by hypersecretion of the pituitary growth hormones. It is characterized by enlargement of many parts of the skeleton, especially the nose, ears, jaws, fingers and toes. See also Pituitary Gland.
See AIDS Clinical Trials Group.
An infection causing disease with a sudden onset, severity and (often) short course. As related to HIV infection: Once the virus enters the body, HIV infects a large number of CD4+ T cells and replicates rapidly. During this acute or primary phase of infection, the blood contains many viral particles that spread throughout the body, seeding themselves in various organs, particularly the lymphoid tissues. See also Acute Retroviral Syndrome; CD4 (T4) or CD4+ Cells; Infection; Lymphoid Organs.
ACUTE RETROVIRAL SYNDROME:
The acute or primary HIV infection often passes unrecognized, but may be present as a mononucleosis-like syndrome within three months of the infection. The diagnosis is made by demonstrating HIV antibody seroconversion. See also Seroconversion.
(Acycloguanosine). A nucleoside analog antiviral drug used to treat the symptoms of the genital form of herpes simplex virus infection. See also Herpes Simplex Virus; Nucleoside Analog.
Any disease involving or causing enlargement of glandular tissues, especially one involving the lymph nodes.
An ingredient-as in a prescription or solution-that facilitates or modifies the action of the principal ingredient. May be used in HIV therapies or for HIV vaccines.
(Route of Administration). A term used to refer to how a drug or therapy is introduced into the body. Systemic administration means that the drug goes throughout the body (usually carried in the bloodstream), and includes oral administration (by mouth) and intravenous administration (injection into the vein). Local administration means that the drug is applied or introduced into the specific area affected by the disease, such as application directly onto the affected skin surface (topical administration). The effects of most therapies depend upon the ability of the drug to reach the affected area, thus the route of administration and consequent distribution of a drug in the body is an important determinant of its effectiveness.
In a clinical trial, an unwanted effect detected in participants. The term is used whether or not the effect can be attributed to the intervention under study.
See Side Effects.
A form of administration in which a drug, such as pentamidine, is turned into a fine spray or mist by a nebulizer and inhaled. See also Pentamidine.
See AIDS Education and Training Centers.
This includes HIV-positive people, persons living with AIDS and other individuals, including their families, friends and advocates, directly impacted by HIV infection and its physical, psychological and sociological ramifications.
A nearly total absence of immunoglobulins. See also Antibodies.
AGENCY FOR HEALTH CARE POLICY AND RESEARCH (AHCPR):
An agency of the Public Health Service that supports activities to enhance health care services and improve access to them.
See Agency for Health Care Policy and Research.
See Acquired Immunodeficiency Syndrome.
The National Library of Medicine publishes the monthly AIDS Bibliography, which includes all citations from the AIDSLINE database. The AIDS Bibliography is available from the Superintendent of Documents (Phone: 202-783-3238). See also AIDSLINE.
AIDS CLINICAL TRIALS GROUP (ACTG):
The ACTG is composed of a number of US medical centers that valuate treatment for HIV and HIV-associated infections. ACTG studies are sponsored by the National Institute of Allergy and Infectious Diseases.
AIDS DEMENTIA COMPLEX:
About half the people infected with HIV, the virus that causes AIDS, develop infections or other problems involving the brain or spinal cord. These neurological complications may include inflammation of the brain (encephalitis), or of the membrane surrounding the brain (meningitis), infections of the brain, brain or spinal cord tumors, nerve damage, difficulties in thinking and behavioral changes (i.e., AIDS dementia complex) and stroke.
An online database service administered by the National Library of Medicine, with references to drugs undergoing testing against AIDS, AIDS-related complex and related opportunistic infections.
AIDS EDUCATION AND TRAINING CENTERS (AETC):
The Health Resources and Services Administration supports a network of 15 regional centers that serve as resources for educating health professionals in prevention, diagnosis and care of HIV-infected patients. The centers train primary caregivers to incorporate HIV prevention strategies into their clinical priorities, along with diagnosis, counseling and care of HIV-infected persons and their families.
AIDS KNOWLEDGE BASE:
Full-text electronic database on AIDS, available in print as well as electronic form, produced and maintained by physicians and other health care professionals. The database is edited by P.T. Cohen (San Francisco General Hospital), Merle Sande, and Paul Volberding.
An online database service administered by the National Library of Medicine, with citations and abstracts covering the published scientific and medical literature on AIDS and related topics.
Several cancers are more common or more aggressive in people infected with HIV, the virus that causes AIDS. These malignancies include certain types of immune system cancers known as lymphomas, Kaposi's sarcoma and anogenital cancers primarily affecting the cervix and the anus. HIV, or the immune suppression it induces, appears to play a role in the development of these cancers. See also Cervical Cancer; Kaposi's Sarcoma; Lymphoma.
AIDS-RELATED COMPLEX (ARC):
1. A term, not officially defined or recognized by the Centers for Disease Control and Prevention, that 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. 2. Symptoms that appear to be related to infection by the HIV virus. They include an unexplained, chronic deficiency of white blood cells (leukopenia) or a poorly functioning lymphatic system with swelling of the lymph nodes (lymphadenopathy) lasting for more than three months without the opportunistic infections required for a diagnosis of AIDS. See also Wasting Syndrome.
AIDS RESEARCH ADVISORY COMMITTEE:
Board that advises and makes recommendations to the Director, National Institute of Allergy and Infectious Diseases, on all aspects of HIV-related research, vaccine development, pathogenesis and epidemiology.
AIDS SERVICE ORGANIZATION (ASO):
A health association, support agency or other service active in the prevention and treatment of AIDS.
An online database service administered by the National Library of Medicine, with information about clinical trials of agents under evaluation against HIV infection, AIDS and related opportunistic infections.
AIDS WASTING SYNDROME:
See Wasting Syndrome.
An enzyme that is normally present in certain cells within the liver, bone, kidney, intestine and placenta. When the cells are destroyed in those tissues, more of the enzyme leaks into the blood, and levels rise in proportion to the severity of the condition. Measurement of this enzyme is used as an indication of the health of the liver.
The loss of hair that frequently occurs in patients undergoing chemotherapy for cancer or suffering from other diseases, such as AIDS, where cell-killing, or cytotoxic, drugs are used.
In Western countries, alternative therapy refers to any type of medicine that supplements or is used in lieu of biomedicine (i.e., conventional medicine) or allopathic medicine. In other parts of the world, where traditional medicine predominates, the term may refer to biomedicine itself.
Potassium aluminum sulfate or ammonium aluminum sulfate, used especially as an emetic (i.e., an agent that induces vomiting), an astringent (i.e., a substance that contracts tissues) and styptic (i.e., a substance that tends to check bleeding by contracting the tissues or blood vessels).
Pertaining to the alveoli sac, the site of gas exchange in the lungs.
An inflammation of the intestines caused by infestation with Entameba histolytica (a type of ameba) and characterized by frequent, loose stools flecked with blood and mucus.
Any of a class of organic compounds having a carboxyl group (COOH) and an amino group (NH2). Some 22 amino acids are commonly found in animals, and more than 100 less common forms are found in nature, chiefly in plants. When the carboxyl carbon atom of one amino acid binds to the nitrogen of another with the release of a water molecule, a linkage called a peptide bond is formed. Chains of amino acids, joined head-to-tail in this manner, are synthesized by living systems and are called polypeptides (up to about 50 amino acids) and proteins (over 50 amino acids). See also Peptide; Proteins.
The surgical insertion of a hollow needle through the abdominal wall and into the uterus of a pregnant female to obtain amniotic fluid (i.e., the serous fluid in which the embryo is suspended) especially to examine the fetal chromosomes for an abnormality or for the determination of the sex of the embryo. See also Uterus.
In chemistry, a compound with a structure similar to that of another compound, but differing from it in respect to certain components or structural makeup; it may have a similar or opposite action metabolically.
The heightened immunologic reaction elicited by a second or subsequent exposure to a particular pathogenic microorganism or antigen. See also Antigen.
A life-threatening allergic reaction characterized by a swelling of body tissues (including the throat) and a sudden decline in blood pressure.
A lower than normal number of red blood cells.
1. The loss or weakening of the body's immunity to an irritating agent, or antigen. The strength of the body's immune response is often quantitatively measured by means of a skin test where a solution containing an antigen known to cause a response, such as mumps or candida, is injected immediately under the skin. The lack of a reaction to these common antigens indicates anergy. See also Antigen. 2. Researchers in cell culture have shown that CD4+T cells can be turned off by a signal from HIV that leaves them unable to respond to further immune system stimulation. This inactivated state is known as anergy. See also CD4 (T4) or CD4+ Cells.
An antimicrobial agent, derived from cultures of a microorganism or produced semisynthetically, used to treat infections.
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 immunoglobulins, which are produced and secreted by B lymphocytes in response to stimulation by antigens. An antibody is specific to an antigen. See also Antigen; Lymphocyte.
ANTIBODY-DEPENDENT CELL-MEDIATED CYTOTOXICITY (ADCC):
An immune response in which antibodies bind to target cells, identifying them for attack by the immune system. See also Antibodies.
An agent that inhibits intracellular (i.e., inside cells) production of folinic acid. See also Folinic Acid.
A substance that, when introduced into the body, is capable of inducing the production of a specific antibody. See also Antibodies.
An antibody that recognizes and binds to another antibody (idiotype).
Inhibiting or preventing the proliferation of tumor cells.
Substances used against retroviruses such as HIV. See also Retrovirus.
Antibodies that recognize and inactivate toxins produced by certain bacteria, plants or animals. See also Antibodies.
A substance or process that destroys a virus or suppresses its replication.
Cellular suicide, also known as programmed cell death. HIV may induce apoptosis in both infected and uninfected immune system cells. Uninfected cells may also undergo apoptosis. Normally when CD4+ T cells mature in the thymus gland, a small proportion of these cells are unable to distinguish self from nonself. Because these cells would otherwise attack the body's own tissues, they receive a biochemical signal from other cells that results in apoptosis. See also CD4 (T4) or CD4+ Cells; Thymus.
See AIDS-Related Complex.
A group of participants in a clinical trial, all of whom receive the same treatment or placebo. See also Placebo.
A pain in a joint.
See AIDS Service Organization.
A fungal infection (resulting from the fungus Aspergillus) of the lungs that can spread through the blood to other organs. Symptoms include fever, chills, difficulty in breathing and coughing up blood. If the infection reaches the brain, it may cause dementia. See also Dementia.
ASSEMBLY AND BUDDING:
Names for a portion of the processes by which new HIV virus is formed in infected host cells. Viral core proteins, enzymes and RNA (ribonucleic acid) gather just inside the cell's membrane, while the viral envelope proteins aggregate within the membrane. An immature viral particle is formed and then pinches off from the cell, acquiring an envelope and the cellular and HIV proteins from the cell membrane. The immature viral particle then undergoes processing by an HIV enzyme called protease to become an infectious virus. See also Enzyme; Ribonucleic Acid.
Without symptoms. Usually used in AIDS literature to describe a person who has a positive reaction to one of several tests for HIV antibodies, but who shows no clinical symptoms of the disease.
Weakened or decreased. For example, an attenuated virus can no longer produce disease, but might be used to produce a vaccine.
1. An antibody that is active against some of the tissues of the organism that produced it. 2. An antibody directed against the body's own tissue. See also Antibodies.
The induction in an individual of an immune response to its own cells (tissue). See also Immune Response.
Susceptible of being inoculated with microorganisms from one's own body.
Pertaining to the same organism or one of its parts; originating within an organism itself.
Azidothymidine (also called zidovudine or ZDV; the Burroughs-Wellcome trade name is Retrovir). One of the first drugs used against HIV infection, AZT is a nucleoside analog that suppresses replication of HIV. See also Nucleoside Analog.
Capable of killing bacteria.
Capable of inhibiting reproduction of bacteria.
A microscopic organism composed of a single cell. Many bacteria can cause disease in humans.
A virus of insects used in the production of some HIV vaccines. See also Vaccine.
1. Information gathered at the beginning of a study from which variations found in the study are measured. 2. A known value or quantity with which an unknown is compared when measured or assessed.
A type of white blood cell, also called a granular leukocyte, filled with granules of toxic chemicals that can digest microorganisms. Basophils, as well as other types of white blood cells, are responsible for the symptoms of allergy. The granules stain blue when exposed to a basic dye for microscopic examination.
B CELL LYMPHOMA:
See B Lymphocytes.
1. A bile pigment whose measurement can be used as an indication of the health of the liver. 2. A substance released from old or damaged red blood cells. Small amounts of bilirubin normally enter the bloodstream and circulate until they reach the liver and then into the bowel, where bilirubin is further broken down and excreted. The normal value is 0.1 to 1.5 milligrams per liter of blood.
As related to HIV infection: An antibody that attaches to some part of the HIV virus. Binding antibodies may or may not adversely affect the virus.
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. See also Interferon; Interleukin-2; Monoclonal Antibody; Thymus.
The surgical removal of a piece of tissue from a living subject for microscopic examination to make a diagnosis (for example, to determine whether abnormal cells such as cancer cells are present).
1. The use of living organisms or their products to make or modify a substance. These include recombinant DNA techniques (also referred to as genetic engineering) and hybridoma technology. 2. The industrial application of the results of biological research, particularly in fields such as recombinant DNA or gene splicing, which permits the production of synthetic hormones or enzymes by combining genetic material from different species.
A clinical trial in which participants are unaware as to whether or not they are in the experimental or control arm of the study.
BLOOD BRAIN BARRIER:
The barrier between brain blood vessels and brain tissues whose effect is to restrict what may pass from the blood into the brain.
B LYMPHOCYTES (B CELLS):
One of the two major classes of lymphocytes. During infections, these cells are transformed into plasma cells that produce large quantities of antibody directed at specific pathogens. This transformation occurs through interactions with various types of T cells and other components of the immune system. In persons with AIDS, the functional ability of both the B and the T lymphocytes is damaged, with the T lymphocytes being the principal site of infection by the HIV virus. See also Lymphocyte; T Cells.
Any fluid in the human body, such as blood, urine, saliva, sputum (spit), tears, semen, mother's milk or vaginal secretions. Only blood, semen, mother's milk and vaginal secretions have been linked directly to the transmission of the HIV virus.
Soft tissue located in the cavities of the bones where blood cells such as erythrocytes, leukocytes and platelets are formed. See also Erythrocytes; Leukocytes; Platelets.
A second or later dose of a vaccine given to increase the immune response to the original dose. See also Vaccine.
BRANCHED DNA ASSAY:
A sensitive, rapid test that can be used to monitor the amount of HIV in a patient's bloodstream (i.e., the viral burden). See also Viral Burden.
An infection, caused by the infectious agent the vaccine is designed to protect against, that occurs during the course of a vaccine trial. These infections may be caused by exposure to the infectious agent before the vaccine has taken effect, or before all doses of the vaccine have been given. Breakthrough infections also occur in trial participants receiving placebos.
Visual examination of the bronchial passages of the lungs through a tube of an endoscope inserted into the upper lungs or extraction of material from the lungs by means of a bronchoscope. See also Endoscopy.
See Assembly and Budding.
A lymphatic cancer that involves not only the lymphatic and the associated reticuloendothelial system, but also other body tissues. This disease, which is most common in Central Africa, is thought to be possibly caused by the Epstein-Barr virus. Also called African lymphoma, Burkitt's tumor. See also Epstein-Barr Virus; Lymph; Reticuloendothelial Cells.
General ill health and malnutrition, marked by weakness and emaciation, usually associated with serious disease. See also Wasting Syndrome.
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. See also Fungus.
An infection with a fungus of the Candida family, generally Candida albicans; it most commonly involves the skin (dermatocandidiasis), oral mucosa (thrush), respiratory tract (bronchocandidiasis) and vagina (vaginitis). Candidiasis of the esophagus, trachea, bronchi or lungs is an indicator disease for AIDS. See also Fungus; Thrush.
Any cancer-producing substance.
A tubular medical device for insertion into canals, vessels, passageways or body cavities, usually to permit injection (e.g., through an intravenous catheter into a vein) or withdrawal of fluids, or to keep a passage open.
See Community-Based Clinical Trial.
See Community-Based Organization.
See Centers for Disease Control and Prevention.
CD8 (T8) CELLS:
A protein embedded in the cell surface of suppressor T lymphocytes. Also called cytotoxic T cells. See also CD Nomenclature; CD4 (T4) or CD4+ Cells; T Cells.
CD4 (T4) or CD4+ CELLS:
1. White blood cells killed or disabled during HIV infection. These cells normally orchestrate the immune response, signaling other cells in the immune system to perform their special functions. Also known as T helper cells. 2. HIV's preferred targets are cells that have a docking molecule called cluster designation 4 (CD4) on their surfaces. Cells with this molecule are known as CD4-positive (or CD4+) cells. Destruction of CD4+ lymphocytes is the major cause of the immunodeficiency observed in AIDS, and decreasing CD4+ lymphocyte levels appear to be the best indicator of morbidity in these patients. Although CD4 counts fall, the total T-cell level remains fairly constant through the course of HIV disease, due to a concomitant increase in the CD8+ cells. The ratio of CD4+ to CD8+ cells is therefore an important measure of disease progression. See also CD Nomenclature; CD8 (T8) Cells; Immunodeficiency.
CDC NATIONAL AIDS CLEARINGHOUSE:
The CDC's comprehensive reference, referral and publication distribution service for HIV and AIDS information. The Clearinghouse works in partnership with national, regional, state and local organizations that develop and deliver HIV prevention programs and services.
This nomenclature was developed to standardize and compare monoclonal antibodies from different sources. Antibodies with similar reactivity patterns are assigned to CD groups representing "clusters of differentiation." T lymphocytes are CD3+ and can be separated into the CD4+ T helper cells and the CD8+ cytotoxic/suppressor cells. Although CD4+ cells are predominantly T lymphocytes, some monocytes are also CD4+.
Specific cell types artificially maintained in the laboratory (i.e., 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 defense cells (i.e., killer cells, macrophage and other white blood cells) rather than antibodies.
See Cell-Mediated Immunity.
CENTERS FOR DISEASE CONTROL AND PREVENTION (CDC):
A Public Health Service agency responsible (among others) for assessing the status and characteristics of the AIDS epidemic and the prevalence of HIV infections. CDC supports the design, implementation and evaluation of prevention activities, and maintains various HIV/AIDS information services, such as the CDC National AIDS Clearinghouse.
CENTRAL NERVOUS SYSTEM (CNS):
Composed of the brain, spinal cord and its coverings (meninges).
CENTRAL NERVOUS SYSTEM (CNS) DAMAGE:
(By HIV infection). Although monocytes and macrophages can be infected by HIV, they appear to be relatively resistant to killing. However, these cells travel throughout the body and carry HIV to various organs, especially the lungs and the brain. People infected with HIV often experience abnormalities in the central nervous system. Investigators have hypothesized that an accumulation of HIV in brain and nerve cells or the inappropriate release of cytokines or toxic byproducts by these cells may be to blame for the neurological manifestations of HIV disease. See also Cytokines; Macrophage; Monocyte.
Pertaining to the cerebrum, the main portion of the brain.
A neoplasm of the uterine cervix that can be detected in the early curable stage by the Papanicolaou (Pap) test. See also Cervical Dysplasia; Cervix; Pap Smear.
A precursor lesion for cervical cancer. Studies indicate an increase in prevalence of cervical dysplasia among HIV-infected women. Additional studies have documented that a higher prevalence is associated with greater immuno suppression. HIV infection also may adversely affect the clinical course and treatment of cervical dysplasia and cancer. See also Dysplasia.
CERVICAL INTRAEPITHELIAL NEOPLASIA (CIN1, CIN2, CIN3):
Dysplasia of the cervix epithelium, often pre-malignant (i.e., cancerous), characterized by various degrees of hyperplasia, abnormal keratinization (forming horny epidermal tissue) and condylomata. Considerable evidence implicates human papilloma virus (HPV) in the development of CIN. Immunosuppression may also play an important role in facilitating infection or persistence of HPV in the genital tract and progression of HPV-induced neoplasia. See also Cervix; Condyloma; Dysplasia; Epithelium; Hyperplasia; Neoplasm.
The part of the uterus that protrudes into the cavity of the vagina. See also Uterus.
In vaccine experiments, the exposure of an immunized animal to the infectious agent.
The treatment, mostly of cancer, by the use of a series of cytotoxic drugs that attack cancerous cells. This treatment commonly has adverse side effects that may include the temporary loss of the body's natural immunity to infections, loss of hair, digestive upset and a general feeling of illness. Although unpleasant, the adverse effects of treatment are tolerated considering the life-threatening nature of the cancers usually treated by chemotherapy. See also Cytotoxic.
CHRONIC IDIOPATHIC DEMYELINATING POLYNEUROPATHY (CIPD):
Chronic, spontaneous loss or destruction of myelin. Myelin is a soft, white, somewhat fatty material that forms a thick sheath around the protoplasmic core of myelinated nerve fiber.
See Chronic Idiopathic Demyelinating Polyneuropathy.
CIRCULATING IMMUNE COMPLEXES:
See Immune Complex.
A group of related HIV variants, classified according to degree of genetic similarity. HIV variants are currently grouped into clades A, B, C, D, E, F and O.
Pertaining to or founded on observation and treatment of patients, as distinguished from theoretical or basic science.
A mechanism, adopted by the National Institutes of Health in onjunction with the editors of several biomedical journals, for urgent cases in which timely and broad dissemination of results of clinical trials could prevent morbidity (sickness) and mortality (death). The Clinical Alert does not become a barrier to subsequent publication of the full research paper. Clinical Alerts are widely distributed electronically through the National Library of Medicine and through standard mailings.
The state or period of an infectious agent, such as a virus or bacterium, living or developing in a host without producing clinical symptoms. As related to HIV infection: Although infected individuals usually exhibit a period of clinical latency with little evidence of disease, the virus is never truly latent. Even early in the disease, HIV is active within lymphoid organs where large amounts of virus become trapped in the FDC network. Surrounding germinal centers are areas rich in CD4+ T cells. These cells increasingly become infected and viral particles accumulate both in infected cells and as free virus. See also CD4 (T4) or CD4+ Cells; Lymphoid Organs.
CLINICAL PRACTICE GUIDELINES:
Standards for physicians to adhere to in prescribing care for a given condition or illness.
A carefully designed and executed investigation of the effects of a drug (or vaccine) administered to human subjects. The goal is to define the clinical efficacy and pharmacological effects (toxicity, side effects, incompatibilities or interactions) of the drug. The US government, through the Food and Drug Administration, requires strict testing of all new drugs and vaccines prior to their approval for use as therapeutic agents.
1. A group of genetically identical cells or organisms descended from a common ancestor. To produce such genetically identical copies. 2. A genetically identical replication of a living cell that is valuable for the investigation and reproduction of test cultures.
See Central Nervous System.
An infectious fungal disease caused by the inhalation of spores of Coccidioides immitis, which is carried on windblown dust particles. The disease is endemic in hot dry regions of the Southwestern US and Central and South America, and is an opportunistic disease associated with AIDS. Also called desert fever, San Joaquin fever, valleyfever. See also Fungus; Opportunistic Infection.
1. Substances, microorganisms or characteristics of individuals that may influence the progression of a disease or the likelihood of becoming ill. 2. A substance, such as a metallic ion or coenzyme, that must be associated with an enzyme for the enzyme to function. 3. A situation or activity that may increase a person's susceptibility to AIDS. Examples of such cofactors are other infections, drugs and alcohol use, poor nutrition, genetic factors and stress.
In epidemiology, a group of individuals with some characteristics in common.
Inflammation of the colon.
COMMUNITY-BASED CLINICAL TRIAL (CBCT):
A clinical trial conducted primarily through primary-care physicians rather than academic research facilities.
COMMUNITY-BASED ORGANIZATION (CBO):
A locally based service organization that provides social services at the community level.
COMMUNITY PROGRAMS FOR CLINICAL RESEARCH ON AIDS (CPCRA):
An initiative of the National Institute of Allergy and Infectious Diseases (NIAID) to broaden the base of clinical investigations by involving community physicians in AIDS research and trials. NIAID started the CPCRA in 1989. It is one of four HIV clinical trials programs supported by NIAID. In 1992 the name of the program was officially changed to the Terry Beirn Community Programs for Clinical Research on AIDS. (See also Terry Beirn Community Programs for Clinical Research on AIDS).
A method of providing experimental drugs to very sick patients who have no other treatment options. Often, case-by-case approval must be obtained from the Food and Drug Administration for "compassionate use" of a drug.
A group of proteins in normal blood serum and plasma which, in combination with antibodies, causes the destruction of antigens, particularly bacteria and foreign blood corpuscles. See also Antibodies; Antigen.
A precise sequence of events, usually triggered by an antigen-antibody complex, in which each component of the complement system is activated in turn. See also Antibodies; Antigen.
Drugs that are taken together. Certain concomitant medications may have adverse interactions.
Joint French/British clinical trial of AZT in asymptomatic HIV-positive individuals. See also AZT.
(Condyloma acuminatum). A papilloma with a central core of connective tissue in a treelike structure covered with epithelium, usually occurring on the mucous membrane or skin of the external genitals or in the perianal (tissue surrounding the anus) region. Although the lesions are usually few in number, they may aggregate to form large cauliflower-like masses. Caused by the human papilloma virus (HPV), it is infectious and autoinoculable (i.e., capable of being transmitted by inoculation from one part of the body to another). Also called acuminate or venereal warts. See also Epithelium; Papilloma.
Any infectious disease capable of being transmitted by casual contact from one person to another. Casual contact can be defined as normal day-to-day contact between people at home, school, work or in the community. A contagious infection (e.g., a common cold) can be communicable by casual contact; an infectious infection, on the other hand, is communicable by intimate contact such as sex. AIDS is infectious, not contagious.
A specific circumstance when the use of certain treatments could be harmful.
A standard against which experimental observations may be evaluated. In clinical trials, one group of patients is given an experimental drug, while another group (i.e., the control group) is given either a standard treatment for the disease or a placebo. See also Placebo.
As related to HIV: An integral protein of the HIV virus composed of three units, p24, p15 and p18.
CORRELATES OF IMMUNITY/CORRELATES OF PORTECTION:
The immune responses that protect an individual from a certain disease. The precise identities of the correlates of immunity in HIV are unknown.
See Community Programs for Clinical Research on AIDS.
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.
A life-threatening infection of the membranes (meninges) that line the brain and the spinal cord. Cryptococcal disease is caused by a fungus (Cryptococcus neoformans). Most people have been exposed to this organism, which is found in soil contaminated by bird droppings, but it usually does not cause disease in healthy people. The majority of people with cryptococcal meningitis have immune systems that are damaged by disease, such as AIDS, or suppressed by drugs. The organism can infect almost all organs of the body, although it most commonly causes disease of the meninges, skin or lungs.
An infectious disease seen in HIV-infected patients due to the fungus Cryptococcus neoformans, which is acquired via the respiratory tract. It can spread from the lungs to the brain, the central nervous system, the skin, skeletal system and urinary tract. See also Cryptococcal Meningitis.
An opportunistic infection caused by the protozoan parasite Cryptosporidium parvum.
(Computed Tomography). Radiography (using X-rays) in which a three-dimensional image of a body structure is constructed by computer from a series of plane cross-sectional images made along an axis. Also referred to as CAT scan.
See Cytotoxic T Lymphocyte.
Of, pertaining to or affecting the skin.
1. Immune system proteins involved in the normal regulation of the immune response. They may also help to activate HIV-2. Proteins used for communication by cells of the immune system. Central to the normal regulation of the immune response.
A herpes virus that is a common cause of opportunistic diseases in people with AIDS and other people with immune suppression. While CMV can infect most organs of the body, people with AIDS are most susceptible to CMV retinitis (disease of the eye) and colitis (disease of the colon). See also Cytomegalovirus (CMV) Retinitis.
CYTOMEGALOVIRUS (CMV) RETINITIS:
Most adults in the US have been infected by cytomegalovirus, although the virus usually does not cause disease in healthy people. Because the virus remains in the body for life, it can cause disease if the immune system becomes severely damaged by disease or suppressed by drugs. CMV retinitis is an eye disease common among people who are infected with HIV. Without treatment, people with CMV retinitis can lose their vision. CMV infection can affect both eyes and is the most common cause of blindness among people with AIDS.
Deficiency in the cellular elements of the blood.
All of the substance of a cell other than the nucleus.
An agent or process that is toxic to cells (i.e., it causes suppression of function or cell death).
CYTOTOXIC T LYMPHOCYTE (CTL):
A lymphocyte that is able to kill foreign cells that have been marked for destruction by the cellular immune system. See also CD8 (T8) Cells; Lymphocyte.
An organized compilation of information, usually maintained in a computer system.
DATA SAFETY AND MONITORING BOARD (DSMB):
An independent committee, composed of community representatives and clinical research experts, that reviews data while a clinical trial is in progress to ensure that participants are not exposed to undue risk. A DSMB may recommend that a trial be stopped if there are safety concerns or if the trial objectives have been achieved.
See Division of AIDS Treatment Research Initiative.
Dideoxycytidine (zalcitabine, HIVID), a nucleoside analog drug that inhibits the replication of HIV. See also Nucleoside Analog.
Dideoxyinosine (didanosine, Videx), a nucleoside analog drug that inhibits the replication of HIV. See also Nucleoside Analog.
Elimination of a gene (i.e., from a chromosome) either in nature or in the laboratory. See also Gene.
Chronic intellectual impairment (i.e., loss of mental capacity) with organic origins that affects a person's ability to function in a social or occupational setting. See also AIDS Dementia Complex.
Destruction, removal or loss of the myelin sheath of a nerve or nerves. See also Myelin.
Any of the usual branching protoplasmic processes that conduct impulses toward the body of a nerve cell. See also Protoplasm.
Patrolling immune system cells that may begin the HIV disease process by carrying the virus from the site of the infection to the lymph nodes, where other immune cells become infected. Dendritic cells travel through the body and bind to foreign invaders-such as HIV-especially in external tissues, such as the skin and the membranes of the gut, lungs and reproductive tract. They then ferry the foreign substance to the lymph nodes to stimulate T cells and initiate an immune response. In laboratory experiments, the dendritic cells that carry HIV also bind to CD4+ T cells, thereby allowing HIV to infect the CD4+ T cells. CD4+ T cells are the critical immune system cells targeted by HIV and depleted during HIV infection. See also CD4 (T4) or CD4+ Cells; Lymph Nodes; T Cells.
(Also known as Stavudine and Zerit). d4T is a dideoxynucleoside pyrimidine analog (2'3'-didehydro-3'-deoxythymidine). Like other nucleoside analogs, d4T inhibits HIV replication by inducing premature viral DNA chain termination. d4T has been approved for patients with advanced HIV infection intolerant to or failing other antiretroviral drugs. See also Nucleoside Analog.
The determination of the presence of a specific disease or infection, usually accomplished by evaluating clinical symptoms and laboratory tests.
Uncontrolled, loose and frequent bowel movements. In the United States, almost all people with AIDS develop diarrhea at some time in the course of their disease. Severe or prolonged diarrhea can lead to weight loss and malnutrition. The excessive loss of fluid that may occur with AIDS-related diarrhea can be life-threatening. There are many possible causes of diarrhea in people who have AIDS. The most common infectious organism causing AIDS-related diarrhea include cytomegalovirus (CMV); the parasites Cryptosporidium, Microsporidia and Giardia lamblia; and the bacterium Mycobacterium avium-inracellulare (MAC). Other bacteria and parasites that cause diarrheal symptoms in otherwise healthy people may cause more severe, prolonged or recurrent diarrhea in people with HIV or AIDS. See also Cytomegalovirus; Giardiasis; Microsporidiosis; Mycobacterium Avium Complex.
Spread (of a disease) throughout the body.
DIVISION OF AIDS TREATMENT RESEARCH INITIATIVE (DATRI):
An organization established by the National Institute of Allergy and Infectious Diseases as a national network to test new therapies for HIV-infected persons. Its hallmark is the ability to rapidly conduct clinical trials and related research that evaluates new therapies and novel treatment approaches for those with HIV disease.
(Deoxyribonucleic Acid). 1. The molecular chain found in genes within the nucleus of each cell, which carries the genetic information that enables cells to reproduce. 2. DNA is the principal constituent of chromosomes, the structures that transmit hereditary characteristics. The amount of DNA is constant for all typical cells of any given species of plant or animal (including humans), regardless of the size or function of that cell. Each DNA molecule is a long, two-stranded chain made up of subunits, called nucleotides, containing a sugar (deoxyribose), a phosphate group and one of four nitrogenous bases: adenine (A), guanine (G), thymine (T) and cytosine (C). In 1953 J.D. Watson and F.H. Crick proposed that the strands, connected by hydrogen bonds between the bases, were coiled in a double helix. Adenine bonds only with thymine (A-T or T-A) and guanine only with cytosine (G-C or C-G). The complementarity of this bonding ensures that DNA can be replicated (i.e., that identical copies can be made in order to transmit genetic information to the next generation).
A region of a gene or gene product. See also Gene.
A clinical trial in which two or more doses of an agent (such as a drug) are tested against each other to determine which dose works best and is least harmful. See also Clinical Trial.
The relationship between the dose of some agent (such as a drug), or the extent of exposure, and a physiological response. A dose-response effect means that as the dose increases so does the effect.
A clinical trial design in which neither the participating individuals nor the study staff know which patients are receiving the experimental drug and which are receiving placebo or another therapy. Double-blind trials are thought to produce objective results, since the doctor's and patient's expectations about the experimental drug do not affect the outcome. See also Clinical Trial; Placebo.
A modification of the effect of a drug when administered with another drug. The effect may be an increase or a decrease in the action of either substance, or it may be an adverse effect that is not normally associated with either drug.
See Data Safety and Monitoring Board.
Any abnormal development of tissues or organs. In pathology, alteration in size, shape and organization of adult cells.
Difficult or labored breathing.