Subject: e
Date: Thu, 12 Oct 95 23:34 PDT (200 lines of text)

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 Food and Drug Administration, phase II clinical trials gauge efficacy, phase III trials confirm it.
ELISA:
(Enzyme-Linked Immunosorbent Assay). A laboratory test to determine the presence of antibodies to HIV in the blood. A positive ELISA test generally is confirmed by the Western Blot test. See also Antibodies; Western Blot.
EMPIRICAL:
Based on experimental data, not on a theory.
ENCEPHALITIS:
A general term denoting inflammation of the brain.
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.
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:
A gene of HIV that codes for the protein gp160, the precursor of the envelope proteins gp120 and gp41. See also Gene.
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 protein, 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. See also Glycoprotein; gp41; gp120; Lipid.
ENZYME:
A protein that accelerates a specific chemical reaction without altering itself (i.e., 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.
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 US, the 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 in the US population. Collecting blood samples for the purpose of surveillance is called serosurveillance. See also Centers for Disease Control and Prevention; Seroprevalence; Surveillance.
EPIDEMIOLOGY:
The branch of medical science that deals with the incidence, 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 also Antibodies; Antigen.
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 and hairy leukoplakia. See also Burkitt's Lymphoma; Cytomegalovirus; 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. Erythema multiforme has been associated with many infections, collagen disease, drug sensitivities, allergies and pregnancy. A severe form of this condition is Stevens-Johnson Syndrome. See also Lesion; Stevens-Johnson Syndrome.
ERYTHEMATOUS:
Red or reddened.
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 people with chronic liver disease, or may exclude people with certain drug allergies; others may exclude men or women or only include people with a lowered T-cell count.
EXOGENOUS:
Developed or originating outside the body.
EXOTOXIN:
A toxic substance, made by bacteria, that is released outside the bacterial cell.
EXPANDED ACCESS:
A general term for methods of distributing experimental drugs to patients who are unable to participate in ongoing clinical trials and have no other treatment options. Specific types of expanded access mechanisms include parallel track, Treatment IND, and compassionate use. See also Investigational New Drug.
EXPRESSION SYSTEM:
In HIV vaccine production, cells into which an HIV gene has been inserted to produce desired HIV proteins.