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. See also CD4 (T4) or CD4+ Cells; Diarrhea; HIV Disease; Kaposi's Sarcoma; Opportunistic Infection; Wasting Syndrome.
ADJUVANT:
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. Also found in most other vaccines.
ANTIBODIES:
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.
ANTIGEN:
A substance that, when introduced into the body, is capable of inducing the production of a specific antibody. See also Antibodies.
ANTIRETROVIRAL AGENTS:
Substances used against retroviruses such as HIV. See also Retrovirus.
ANTIVIRAL:
A substance or process that destroys a virus or suppresses its replication.
AZT:
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.
BASELINE:
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.
BLINDED STUDY:
A clinical trial in which participants are unaware as to whether or not they are in the experimental or control arm of the study.
BOOSTER:
A second or later dose of a vaccine given to increase the immune response to the original dose. See also Vaccine.
CDC:
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.
CLINICAL TRIAL:
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.
COMPASSIONATE USE:
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.
CONTROL:
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.
DIAGNOSIS:
The determination of the presence of a specific disease or infection, usually accomplished by evaluating clinical symptoms and laboratory tests.
DOUBLE-BLIND STUDY:
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.
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.
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.
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.
FDA:
See Food and Drug Administration.
FOOD AND DRUG ADMINISTRATION (FDA):
The Public Health Service agency responsible for (among others) ensuring the safety and effectiveness of drugs, biologics, vaccines and medical devices used in the diagnosis, treatment and prevention of HIV infection, AIDS and AIDS-related opportunistic infections. The FDA also works with the blood banking industry to safeguard the nation's blood supply. See also Public Health Service.
GASTROINTESTINAL:
Relating to the stomach and intestines.
GLYCOPROTEIN:
A conjugated protein in which the nonprotein group is a carbohydrate (i.e., a sugar molecule); also called glucoprotein.
GP41:
Glycoprotein 41, a protein embedded in the outer envelope of HIV. Plays a key role in HIV's infection of CD4+ T cells by facilitating the fusion of the viral and the cell membranes.
GP120:
Glycoprotein 120, a protein that protrudes from the surface of HIV and binds to CD4+ T cells.
HAART:
See Highly Active Antiretroviral Therapy
HEPATITIS:
An inflammation of the liver caused by certain viruses and other factors such as alcohol abuse, some medications and trauma. Although many cases of hepatitis are not a serious threat to health, the disease can become chronic and can sometimes lead to liver failure and death. There are four major types of viral hepatitis: (a) hepatitis A, caused by infection with the hepatitis A virus; (b) hepatitis B, caused by infection with the hepatitis B virus (HBV), which is most commonly passed on to a partner during intercourse, especially during anal sex, as well as through sharing drug needles; (c) non-A, non-B hepatitis, caused by the hepatitis C virus, which appears to be spread through sexual contact as well as through sharing drug needles (another type of non-A, non-B hepatitis is caused by the hepatitis E virus, principally spread through contaminated water) (d) delta hepatitis occurs only in people who are already infected with HBV and is caused by the HDV virus; most cases of delta hepatitis occur among people who are frequently exposed to blood and blood products such as people with hemophilia. See also Hemophilia.
HIGHLY ACTIVE ANTRETROVIRAL THERAPY:
The standard of treatment for HIV and AIDS in the developed world. HAART therapy consists of a regimen of various combinations of antretroviral drugs including both Reverse Transcriptase Inhibitors and Protease Inhibitors. The use of combinations of drugs has been shown to suppress viral activity in the face of viral resistance.
HUMAN IMMUNODEFICIENCY VIRUS TYPE 1 (HIV-1):
1. The retrovirus isolated and recognized as the etiologic (i.e., causing or contributing to the cause of a disease) agent of AIDS. HIV-1 is classified as a lentivirus in a subgroup of retroviruses. See also Lentivirus; Retrovirus. 2. Most viruses and all bacteria, plants and animals have genetic codes made up of DNA, which uses RNA to build specific proteins. The genetic material of a retrovirus such as HIV is the RNA itself. HIV inserts its own RNA into the host cell's DNA, preventing the host cell from carrying out its natural functions and turning it into an HIV virus factory. See also DNA; Ribonucleic Acid.
HUMAN IMMUNODEFICIENCY VIRUS TYPE 2 (HIV-2):
A virus closely related to HIV-1 that has been found to cause immune suppression. Most common in Africa.
IMMUNE-BASED THERAPY:
A treatment that activates, enhances or otherwise modulates the immune system of the patient to help fight infection or disease.
IMMUNE DEFICIENCY:
A breakdown or inability of certain parts of the immune system to function, thus making a person susceptible to certain diseases that they would not ordinarily develop.
IMMUNE RESPONSE:
The activity of the immune system against foreign substances.
IMMUNE SYSTEM:
The complex functions of the body that recognize foreign agents or substances, neutralize them and recall the response later when confronted with the same challenge.
IMMUNITY:
A natural or acquired resistance to a specific disease. Immunity may be partial or complete, long-lasting or temporary.
IMMUNOCOMPETENT:
1. Capable of developing an immune response. 2. Possessing a normal immune system.
IMMUNODEFICIENCY:
A deficiency of immune response or a disorder characterized by deficient immune response; classified as antibody (B cell), cellular (T cell), combined deficiency or phagocytic dysfunction disorders.
IMMUNOMODULATOR:
Any substance that influences the immune system.
IMMUNOSTIMULANT:
Any agent or substance that triggers or enhances the body's defense; also called immunopotentiators.
IMMUNOSUPPRESSION:
A state of the body in which the immune system is damaged and does not perform its normal functions. Immunosuppression may be induced by drugs or result from certain disease processes, such as HIV infection. See also Immune System.
IMMUNOTHERAPY:
Treatment aimed at reconstituting an impaired immune system. See also Immune System.
INCLUSION/EXCLUSION 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 allow people with chronic liver disease or with certain drug allergies; others may exclude men or women, or only include people with a lowered T-cell count.
IND:
See Investigational New Drug.
INFECTION:
The state or condition in which the body (or part of the body) is invaded by an infectious agent (e.g., a bacterium, fungus or virus), which multiplies and produces an injurious effect (active infection). As related to HIV: Infection typically begins when HIV encounters a CD4+ cell. The HIV surface protein gp120 binds tightly to the CD4 molecule on the cell's surface. The membranes of the virus and the cell fuse, a process governed by gp41, another surface protein. The viral core, containing HIV's RNA, proteins and enzymes, is released into the cell. See CD4 (T4) or CD4+ Cells; gp41; gp120.
INFECTIOUS:
Capable of being transmitted by infection, with or without actual contact. See also Infection.
INFORMED CONSENT:
Type of protection available to people considering entering a drug trial. Before entering the trial, participants must sign a consent form that contains an explanation of: (a) why the research is being done, (b) what researchers want to accomplish, (c) what will be done during the trial and for how long, (d) what risks are in the trial, (e) what benefits can be expected from the trial, (f) what other treatments are available, and (g) the participant's right to leave the trial at any time. See also Clinical Trial.
INTRAMUSCULAR:
Injected directly into a muscle.
INVESTIGATIONAL NEW DRUG (IND):
The status of an experimental drug after the Food and Drug Administration agrees that it can be tested in people.
IN VITRO:
("In glass"). An artificial environment created outside a living organism (e.g., a test tube or culture plate) used in experimental research to study a disease or process.
IN VIVO:
("In life"). Studies conducted within a living organism (e.g., animal or human studies).
LYMPHOCYTE:
A white blood cell. Present in the blood, lymph and lymphoid tissue.
MUTATION:
In biology, a sudden change in a gene or unit of hereditary material that results in a new inheritable characteristic. In higher animals and many higher plants, a mutation may be transmitted to future generations only if it occurs in germ-or sex cell-tissue; body cell mutations cannot be inherited. Changes within the chemical structure of single genes may be induced by exposure to radiation, temperature extremes and certain chemicals. The term mutation may also be used to include losses or rearrangements of segments of chromosomes, the long strands of genes. Drugs such as colchicine double the normal number of chromosomes in a cell by interfering with cell division. Mutation, which can establish new traits in a population, is important in evolution. As related to HIV: HIV mutates rapidly. During the course of HIV disease, viral strains may emerge in an infected individual that differ widely in their ability to infect and kill different cell types, as well as in their rate of replication. Strains of HIV from patients with advanced disease appear to be more virulent and infect more cell types than strains obtained earlier from the same individual. See also Gene.
NATURAL KILLER CELLS:
(NK cells). A type of lymphocyte that does not carry the markers to be B cells or T cells. Like cytotoxic T cells, they attack and kill tumor cells and protect against a wide variety of infectious microbes. They are "natural" killers because they do not need additional stimulation or need to recognize a specific antigen in order to attack and kill. Persons with immunodeficiences such as those caused by HIV infection have a decrease in "natural" killer cell activity. See also Antigen; B Lymphocytes; Cytotoxic; Lymphocyte; Null Cell; T Cells.
OPPORTUNISTIC INFECTION:
1. An illness caused by an organism that usually does not cause disease in a person with a normal immune system. People with advanced HIV infection suffer opportunistic infections of the lungs, brain, eyes and other organs. 2. Opportunistic infections common in AIDS patients include Pneumocystis carinii pneumonia, Kaposi's sarcoma, shigellosis, histoplasmosis and other parasitic, viral, and fungal infections, and some types of cancers. See also Histoplasmosis; Kaposi's Sarcoma; Pneumocystis carinii Pneumonia.
p24:
1. Within the envelope of the HIV virus is a bullet-shaped core made of another protein, p24, that surrounds the viral RNA. 2. The p24 antigen test looks for the presence of this protein in a patient's blood. 3. A positive result for the p24 antigen suggests active HIV replication. p24 found in the peripheral blood is thought to also correlate with the amount of virus in the peripheral blood. It is believed that there are measurable levels of p24 when first infected with the virus after which there is a strong antibody response to p24 in early disease. Low or unmeasurable levels of p24 may indicate that the virus is in a dormant stage. Spikes in p24 levels may indicate that HIV has begun active replication.
PBMC:
See Peripheral Blood Mononuclear Cell.
PCR:
See Polymerase Chain Reaction.
PERIPHERAL BLOOD MONONUCLEAR CELL (PBMC):
Cells in the bloodstream with one nucleus. See also Nucleus.
PLACEBO:
An inactive substance against which investigational treatments are compared for efficacy. See also Placebo Controlled Study.
PLACEBO CONTROLLED STUDY:
A method of investigation of drugs in which an inactive substance (the placebo) is given to one group of patients, while the drug being tested is given to another group. The results obtained in the two groups are then compared.
PLACEBO EFFECT:
A physical or emotional change occurring after a substance is taken or administered that is not the result of any special property of the substance. The change may be beneficial, reflecting the expectations of the patient and, often, the expectations of the person giving the substance.
POLYMERASE CHAIN REACTION (PCR):
1. A laboratory process that selects a DNA segment from a mixture of DNA chains and rapidly replicates it; used to create a large, readily analyzed sample of a piece of DNA. It is used in DNA fingerprinting and in medical tests to identify diseases from the infectious agent's DNA. See also DNA. 2. As related to HIV: A sensitive laboratory technique that can detect and quantify HIV in a person's blood or lymph node.
PROTEASE INHIBITORS:
HIV protease is an aspartyl enzyme essential to the replicative life cycle of HIV. The three-dimensional molecular structure of the HIV protease has been fully determined. Pharmaceutical developers are therefore able to rationally design compounds to inhibit it and thus interfere with replication of the virus. In the US, five peptide-based protease inhibitors (saquinavir, Roche; A-80987, ABT-538, Abbott Laboratories; L735,524, Merck; KNI-272, NCI) are in clinical development. All compounds inhibit HIV-1 in vitro in nanomolar concentrations. In Europe, two peptide-based compounds (ABT-987, Abbott Laboratories; AG-1343, Agouron Pharmaceuticals, Inc.) are currently in development. See also In Vitro.
PROTEINS:
Any of the group of highly complex organic compounds found in all living cells. Protein is the most abundant class of all biological molecules, comprising about 50 percent of cellular dry weight. Classified by biological function, proteins include the enzymes, which catalyze cellular reactions; collagen, keratin and elastin, which are structural, or support, proteins; hemoglobin and other transport proteins; casein, ovalbumin and other nutrient proteins; antibodies, which are necessary for immunity; protein hormones, which regulate metabolism; and proteins such as actin and myosin, the contractile muscle proteins that perform mechanical work. Structurally, proteins are large molecules composed of one or more chains of varying amounts of the same 22 amino acids, which are linked by peptide bonds. Each protein is characterized by a unique and invariant amino acid sequence. Protein chains may contain hundreds of amino acids; some proteins also incorporate phosphorus or such metals as iron, zinc and copper. The amino acid sequence also determines the molecule's three-dimensional structure; this so-called native state is required for proper biological function. The information for the syntheses of the specific amino acid sequences from free amino acids is carried by the cell's nucleic acid. See also Peptide; Ribonucleic Acid.
PROTOCOL:
The detailed plan for a clinical trial that states the trial's rationale, purpose, drug or vaccine dosages, length of study, routes of administration, who may participate and other aspects of trial design. See also Clinical Trial; Inclusion/Exclusion Criteria.
RANDOMIZED TRIAL:
A study in which participants are randomly assigned to either a treatment arm or placebo arm of a clinical trial. See also Clinical Trial; Placebo.
RECEPTOR:
A molecule on the surface of a cell that serves as a recognition or binding site for antigens, antibodies or other cellular or immunological components. See also Antibodies; Antigen.
RETROVIRUS:
HIV and other viruses that carry their genetic material in the form of RNA and that have the enzyme reverse transcriptase. Like all viruses, HIV can replicate only inside cells, commandeering the cell's machinery to reproduce. Like other retroviruses, HIV uses the enzyme called reverse transcriptase to convert its RNA into DNA, which is then integrated into the host cell DNA. See also DNA; Reverse Transcriptase; Ribonucleic Acid.
SEXUALLY TRANSMITTED DISEASE (STD):
Also called venereal disease. A contagious disease usually acquired by sexual intercourse or genital contact. Historically, the five venereal diseases were: gonorrhea, syphilis, chancroid, granuloma inguinale and lymphogranuloma venereum. To these have been added scabies, herpes genitalis and anorectal herpes and warts, pediculosis, trichomoniasis, genital candidiasis, molluscum contagiosum, nonspecific urethritis, chlamydial infections, cytomegalovirus and AIDS. See also Herpes Simplex Virus II; Molluscum Contagiosum.
SIDE EFFECTS:
The action or effect of a drug (or vaccine) other than that desired. The term usually refers to undesired or negative effects, such as headache, skin irritation or liver damage. Experimental drugs must be evaluated for both immediate and long-term side effects.
STATISTICAL SIGNIFICANCE:
A term based on statistical tests that is used to denote the probability that the observed association could have occurred by chance alone. Does not refer to medical or biological significance of an association. For example, a statistical significance at the 1-percent level indicates a 1-in-100 chance that a result can be ascribed to chance.
STD:
See Sexually Transmitted Disease.
T CELLS:
(T Lymphocytes). A thymus-derived white blood cell that participates in a variety of cell-mediated immune reactions. Three fundamentally different types of T cells are recognized: helper, killer and suppressor (each has many subdivisions). T lymphocytes are CD3+ and can be separated into the CD4+ T helper cells and the CD8+ cytotoxic/suppresssor cells. See also Thymus.
THERAPEUTIC HIV VACCINE:
A vaccine designed to boost the immune response to HIV in persons already infected with the virus.
THYMUS:
A mass of glandular tissue located in the neck or chest of most vertebrates. Found in the upper chest under the breastbone in humans, the thymus is essential to the development of the body's system of immunity beginning in fetal life (i.e., before birth). The thymus processes white blood cells, known as lymphocytes, which kill foreign cells and stimulate other immune cells to produce antibodies. The gland grows throughout childhood until puberty and then gradually decreases in size. See also Antibodies; Lymphocyte.
TOXICITY:
The extent, quality or degree of being poisonous or harmful to the body.
TRANSMISSION:
In the context of HIV disease: HIV is spread most commonly by sexual contact with an infected partner. The virus can enter the body through the mucosal lining of the vagina, vulva, penis, rectum or, very rarely, the mouth during sex. The likelihood of transmission is increased by factors that may damage these linings, especially other sexually transmitted diseases that cause ulcers or inflammation. Studies of SIV infection of the genital membranes of nonhuman primates suggest that the sentinel cells known as mucosal dendritic cells may be the first cells infected. Infected dendritic cells may migrate to lymph nodes and infect other cells. HIV also is spread through contact with infected blood, most often by the sharing of drug needles or syringes contaminated with minute quantities of blood containing the virus. Children can contract HIV from their infected mothers either during pregnancy or birth, or postnatally, via breastfeeding. Current research indicates that the AIDS virus may be 100 to 1000 times more contagious during the first two months of infection, when routine AIDS tests are unable to tell whether people are infected. See also Lymph Nodes; Simian Immunodeficiency Virus.
VACCINATION:
Inoculation of a substance (vaccine) into the body for the purpose of producing active immunity against a disease. The vaccine is usually a weakened culture of the agent causing the disease; the use of vaccines is a cornerstone of preventive medicine. Vaccination was used in ancient times in China, India and Persia, and was introduced to the West in the late 18th century by E. Jenner. Vaccinations have eradicated smallpox and are used today to prevent diphtheria, poliomyelitis, rabies and typhoid. Experimental vaccines for certain cancers have been developed for laboratory mice. See also Inoculation.
VACCINE:
A substance that contains antigenic components from an infectious organism. By stimulating an immune response (but not disease), it protects against subsequent infection by that organism. See also Antigen; Vaccination.
VIRAL BURDEN:
(Viral Load). The amount of HIV virus in the circulating blood. Monitoring a person's viral burden is important because of the apparent correlation between the amount of virus in the blood and the severity of the disease: sicker patients generally have more virus than those with less advanced disease. A new, sensitive, rapid test-called the branched DNA assay for HIV-1 infection-can be used to monitor the HIV viral burden. In the future, this procedure may help clinicians to decide when to give anti-HIV therapy. It may also help investigators determine more quickly if experimental HIV therapies are effective.
VIRAL ENVELOPE:
As related to HIV: HIV is spherical in shape with a diameter of 1/10,000 of a millimeter. The outer coat, or envelope, 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.
VIRAL LOAD:
See Viral Burden.
VIROLOGY:
The study of viruses and viral disease.
VIRUS:
Organism composed mainly of nucleic acid within a protein coat, ranging in size from 100 to 2000 angstroms (unit of length; 1 angstrom is equal to 10-10 meters); they can be seen only with an electron microscope. During the stage of their life cycle when they are free and infectious, viruses do not carry out the usual functions of living cells, such as respiration and growth; however, when they enter a living plant, animal or bacterial cell, they make use of the host cell's chemical energy and protein- and nucleic acid-synthesizing ability to replicate themselves. Viral nucleic acids are single- or double-stranded and may be DNA (deoxyribonucleic acid) or RNA (ribonucleic acid). After viral components are made by the infected host cell, virus particles are released; the host cell is often dissolved. Some viruses do not kill cells but transform them into a cancerous state; some cause illness and then seem to disappear, while remaining latent and later causing another, sometimes much more severe, form of disease. Viruses, known to cause cancer in animals, are suspected of causing cancer in humans. Viruses also cause measles, mumps, yellow fever, poliomyelitis, influenza and the common cold. Some viral infections can be treated with drugs. See also DNA; Nucleic Acid; Ribonucleic Acid.
WESTERN BLOT:
A laboratory test for the presence of specific antibodies, more accurate than the ELISA test. See also Antibodies; ELISA.
© D. Sander, 1995-2002
