EDEMA:
An abnormal swelling resulting from the accumulation of fluid in the spaces between tissues.
EFAVIRENZ:
An FDA approved (09/18/98) non-nucleoside reverse transcriptase inhibitor for combination use with other antiretroviral agents for adults and children with HIV infection. Also called Sustiva.
EFFICACY:
(Of a drug or treatment). The maximum ability of a drug
or treatment to produce a result regardless of dosage. A drug passes efficacy trials if it is effective at the dose tested and against the illness for which it is prescribed. In the procedure mandated by the FDA, Phase II clinical trials gauge efficacy, and Phase III trials confirm it.
ELISA:
(Enzyme-Linked Immunosorbent Assay). A type of enzyme immunoassay (EIA) to determine the presence of antibodies to HIV in the blood or oral fluids. Repeatedly reactive (i.e., two or more) ELISA test results should be validated with an independent supplemental test of high specificity. In the U.S. the validation test used most often is the Western Blot test.
EMPIRICAL:
Based on experimental data, not on a theory.
ENCEPHALITIS:
A brain inflammation of viral or other microbial origin. Symptoms include headaches, neck pain, fever, nausea, vomiting, and nervous system problems. Several types of opportunistic infections can cause encephalitis.
ENDEMIC:
Pertaining to diseases associated with particular locales or population groups.
ENDOGENOUS:
Relating to or produced by the body.
ENDOSCOPY:
Viewing the inside of a body cavity (e.g., colon) with an endoscope, a device using flexible fiber optics.
ENDOTOXIN:
A toxin present inside a bacterial cell.
ENDPOINT:
A category of data used to compare the outcome in different arms of a clinical trial. Common endpoints are severe toxicity, disease progression, or -- especially in HIV disease -- surrogate markers, such as CD4 count; sometimes death is used as an endpoint. The term is confusing because it often incorrectly implies that patients in a study are no longer followed after they experience an endpoint. This is obviously true where the event is death, but need not be so for nonfatal events. In fact, the design of the trial may require continued treatment and follow-up of patients over the entire course of the trial, regardless of the number of nonfatal "endpoints" observed.
END-STAGE DISEASE:
Final period or phase in the course of a disease leading to a person's death.
ENTERIC:
Pertaining to the intestines.
ENTERITIS:
Inflammation of the intestine.
ENV:
(env) A gene of HIV that codes for the protein gp160, the precursor of the envelope proteins gp120 and gp41. See gp160; gp120; gp41.
ENVELOPE:
In virology, a protein covering that packages the virus's genetic information. The outer coat, or envelope, of HIV is composed of two layers of fat-like molecules called lipids taken from the membranes of human cells. Embedded in the envelope are numerous cellular proteins, as well as mushroom-shaped HIV proteins that protrude from the surface. Each mushroom is thought to consist of a cap made of four glycoprotein molecules called gp120, and a stem consisting of four gp41 molecules embedded in the envelope. The virus uses these proteins to attach to and infect cells.
ENZYME:
A cellular protein whose shape allows it to hold together several other molecules in close proximity to each other. In this way, enzymes are able to induce chemical reactions in other substances with little expenditure of energy and without being changed themselves. Basically, an enzyme acts as a catalyst.
EOSINOPHIL:
A type of white blood cell, called granulocyte, that can digest microorganisms. The granules can be stained by the acid dye, eosin, for microscopic examination.
EOSINOPHILLIC FOLLICULITIS:
An inflammatory reaction around hair follicles, characterized by very itchy papules (small elevation or bump on the skin) that may grow together to form plaques. The cause of this condition in persons with AIDS has yet to be established; it involves invasion of the follicles by eosinophils. Partially successful treatment has been reported with ultraviolet light, steroids, antihistamines, and itraconazole.
EPIDEMIC:
A disease that spreads rapidly through a demographic segment of the human population, such as everyone in a given geographic area; a military base, or similar population unit; or everyone
of a certain age or sex, such as the children or women of a region. Epidemic diseases can be spread from person to person or from a contaminated source such as food or water.
EPIDEMIOLOGIC SURVEILLANCE:
The ongoing and systematic collection, analysis, and interpretation of data about a disease or health condition. As part of a surveillance system to monitor the HIV epidemic in the U.S., the Centers for Disease Control and Prevention (CDC), in collaboration with state and local health departments, other federal agencies, blood collection agencies, and medical research institutions, conducts standardized HIV seroprevalence surveys in designated subgroups of the U.S. population. Collecting blood samples for the purpose of surveillance is called serosurveillance.
EPIDEMIOLOGY:
The branch of medical science that deals with
the study of incidence and distribution and control of a disease in a population.
EPITHELIUM:
The covering of the internal and external organs of the body. Also the lining of vessels, body cavities, glands, and organs. It consists of cells bound together by connective material and varies in the number of layers and the kinds of cells.
EPITOPE:
A unique shape or marker carried on an antigen's surface that triggers a corresponding antibody response. See Antibodies; Antigen.
EPIVIR:
See Lamivudine.
EPSTEIN-BARR VIRUS (EBV):
A herpes-like virus that causes one of the two kinds of mononucleosis (the other is caused by CMV, see). It infects the nose and throat and is contagious. EBV lies dormant in the lymph glands and has been associated with Burkitt's lymphoma and hairy leukoplakia.
ERYTHEMA:
Redness or inflammation of the skin or mucous membranes.
ERYTHEMA MULTIFORME:
A skin disease characterized by papular (small, solid, usually conic elevation of the skin) or vesicular lesions (blisters), and reddening or discoloration of the skin often in concentric zones about the lesion. Associated with many infections, collagen disease, drug sensitivities, allergies, and pregnancy. A severe form of this condition is Stevens-Johnson Syndrome.
ERYTHROCYTES:
Red blood cells whose major function is to carry oxygen to cells.
ETIOLOGY:
The study or theory of the factors that cause disease.
EXCLUSION/INCLUSION CRITERIA:
The medical or social standards determining whether a person may or may not be allowed to enter a clinical trial. For example, some trials may not include persons with chronic liver disease, or may exclude persons with certain drug allergies; others may exclude men or women or only include persons with a lowered T cell count.
EXOGENOUS:
Developed or originating outside the body.
EXOTOXIN:
A toxic substance, made by bacteria released outside the bacterial cell.
EXPANDED ACCESS:
Refers to any of the FDA procedures, such as compassionate use, parallel track, and treatment IND, that distribute experimental drugs to patients who are failing on currently available treatments for their condition and also are unable to participate in ongoing clinical trials.
EXPERIMENTAL DRUG:
A drug that is not FDA licensed for use in humans, or as a treatment for a particular condition. See also off-label use.
EXPRESSION SYSTEM:
In HIV vaccine production, cells into which an HIV gene has been inserted to produce desired HIV proteins.
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