A
AIDS: A severe immunologist disorder caused by the retrovirus HIV, resulting in a defect in cell-mediated immune response that is manifested by increased susceptibility to opportunistic infections and to certain rare cancers, especially Kaposi's sarcoma. It is transmitted primarily by exposure to contaminated body fluids, especially blood and semen.
AZT: A nucleoside analogue antiviral drug that inhibits the replication of retro viruses such as HIV by interfering with the enzyme reverse transcripts. Also called zidovudine.
C
Conjunctiva: The mucous membrane that lines the inner surface of the eyelid and the exposed surface of the eyeball.
Conjunctivitis: Inflammation of the conjunctiva, characterized by redness and often accompanied by a discharge.
Cryptosporidium: A protozoan of the genus Cryptosporidium that is an intestinal parasite in humans and other vertebrates and sometimes causes diarrhea that is especially severe in immunocompromised individuals.
Cytomegalovirus: Any of a group of herpes viruses that attack and enlarge epithelial cells. Such viruses also cause a disease of infants characterized by circulatory dysfunction and microcephaly.
D
DNA: A nucleic acid that carries the genetic information in the cell and is capable of self-replication and synthesis of RNA. DNA consists of two long chains of nucleotides twisted into a double helix and joined by hydrogen bonds between the complementary bases adenine and thymine or cytosine and guanine. The sequence of nucleotides determines individual hereditary characteristics.
ddI: A nucleoside analogue antiviral drug that inhibits replication of retro viruses such as HIV by interfering with the enzyme reverse transcripts. Also called didanosine.
G
Gay-Rights Movement: gay-rights movement, organized efforts to end the criminalization of homosexuality and protect the civil rights of homosexuals. While there was some organized activity on behalf of the rights of homosexuals in the first half of the 20th cent., the modern gay-rights movement in the United States is usually said to have begun with the Stonewall riot (June, 1969) in New York City, which resulted from a police raid on a gay bar. A number of groups formed to work for the repeal of laws prohibiting consensual homosexual conduct; for legislation barring discrimination against gays in housing and employment; and for greater acceptance of homosexuals among the rest of the population. By 1999 the antisodomy laws of 32 states had been repealed or declared unconstitutional; in all but five of the remaining states, the antisodomy laws applied to both heterosexuals and homosexuals.
H
Hemophilia: Any of several hereditary blood-coagulation disorders in which the blood fails to clot normally because of a deficiency or abnormality of one of the clotting factors. Hemophilia, a recessive trait associated with the X-chromosome, is manifested almost exclusively in males.
Hepatitis: Inflammation of the liver caused by infectious or toxic agents and characterized by jaundice, fever, liver enlargement, and abdominal pain.
Hepatitis A: An infection of the liver that is caused by an RNA virus, is transmitted by ingestion of infected food and water, and has a shorter incubation and generally milder symptoms than hepatitis B. Also called infectious hepatitis.
Hepatitis B: An infection of the liver that is caused by a DNA virus is transmitted by contaminated blood or blood derivatives in transfusions, by sexual contact with an infected person, or by the use of contaminated needles and instruments. The disease has a long incubation and symptoms that may become severe or chronic, causing serious damage to the liver. Also called serum hepatitis.
Hepatitis C : An infection of the liver that is caused by an RNA virus is transmitted primarily by blood and blood products, as in blood transfusions or intravenous drug use, and sometimes through sexual contact. Most cases of non-A, non-B hepatitis are of this type.
Hepatitis D : An acute or chronic infection of the liver caused by an RNA virus, occurring either simultaneously with hepatitis B or as a super infection in a hepatitis B carrier. It is usually more severe than other forms of hepatitis, is transmitted sexually or by exposure to infected blood or blood products, and is most prevalent in tropical and subtropical areas of the Mediterranean basin.
Herpes Simplex: A recurrent viral disease caused by the herpes simplex virus, type one, and marked by the eruption of fluid-containing vesicles on the mouth, lips, or face. Or a recurrent viral disease caused by the herpes simplex virus, type two, and marked by the eruption of fluid-containing vesicles on the genitals.
HIV: A retrovirus that causes AIDS by infecting helper T cells of the immune system. The most common serotype, HIV-1, is distributed worldwide, while HIV-2 is primarily confined to West Africa.
I
Immunity: The ability of an organism to resist disease by identifying and destroying foreign substances or organisms. Although all animals have some immune capabilities, little is known about nonmammalian immunity. Mammals are protected by a variety of preventive mechanisms, some of them nonspecific (e.g., barriers, such as the skin), others highly specific (e.g., the response of antibodies). Herpes Zoster: An acute viral infection characterized by inflammation of the sensory ganglia of certain spinal or cranial nerves and the eruption of vesicles along the affected nerve path. It usually strikes only one side of the body and is often accompanied by severe neuralgia. Also called shingles.
K
Kaposi's sarcoma: a usually fatal cancer that was considered rare until its appearance in AIDS patients. First described by an Austro-Hungarian physician, Moritz Kaposi, in 1872, it appears in three forms and is characterized by vascular skin tumors. Kaposi's sarcoma is endemic in Africa, where it is more aggressive, seen in children and young men, and accounts for 10% of malignancies in Congo (Kinshasa) and Uganda. A mild form of the disease is sometimes seen in elderly men of Mediterranean origin. The development of AIDS-related Kaposi's sarcoma has been linked to a virus of the herpes group. In the early 1980s it was seen in nearly 50% of AIDS patients, but the proportion has decreased since that time. In AIDS, Kaposi's presents as barely raised pink or red papules or plaques that become widely disseminated on the skin and in the gastrointestinal and respiratory tracts, where they may cause extensive bleeding. Treatment includes chemotherapy or surgical excision, cryosurgury (destruction by freezing), or electrodessication (destruction by heat). Local radiation therapy can also be effective. AIDS patients are treated with Vinblastine, an active, but weak, agent, which further lowers immunity.
L
Lymphoma: Any of various usually malignant tumors that arise in the lymph nodes or in other lymphoid tissue.
P
Pneumonia: An acute or chronic disease marked by inflammation of the lungs and caused by viruses, bacteria, or other microorganisms and sometimes by physical and chemical irritants.
T
T cell: Any of the lymphocytes that mature in the thymus and have the ability to recognize specific peptide antigens through the receptors on their cell surface. Also called T lymphocyte.
T lymphocyte: Any of the nearly colorless cells found in the blood, lymph, and lymphoid tissues, constituting approximately 25 percent of white blood cells and including B cells, which function in humoral immunity, and T cells, which function in cellular immunity. RNA: A polymeric constituent of all living cells and many viruses, consisting of a long, usually single-stranded chain of alternating phosphate and ribose units with the bases adenine, guanine, cytosine, and uracil bonded to the ribose. The structure and base sequence of RNA are determinants of protein synthesis and the transmission of genetic information. Also called ribonucleic acid.
Thrush: A contagious disease caused by a fungus, Candida albicans, that occurs most often in infants and children, characterized by small whitish eruptions on the mouth, throat, and tongue, and usually accompanied by fever, colic, and diarrhea.
Tuberculosis: An infectious disease of humans and animals caused by the tubercle bacillus and characterized by the formation of tubercles on the lungs and other tissues of the body, often developing long after the initial infection. Tuberculosis of the lungs, characterized by the coughing up of mucus and sputum, fever, weight loss, and chest pain.
