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Abstract - a written summary of the important points of a scientific article.
Acquired Immune Deficiency Syndrome (AIDS) - the late stage of HIV disease. AIDS involves the loss of function of the immune system as CD4 cells are infected and destroyed, allowing the body to succumb to opportunistic infections that are generally not pathogenic in people with intact immune systems. Common symptoms of AIDS include malignancies and wasting syndrome. The Center for Disease control and prevention (CDC) defines AIDS as the presence of at least one of several opportunistic infections or the presence of fewer than 200 CD4 cells/mm3 in an HIV positive individual.
Active Immunity - immunity naturally produced by the body's own immune system in response to stimulation by foreign antigens. Contrast with passive immunity.
Active Immunization - a process by which a person is inoculated with an antigen to encourage their immune system to mount an immune response, e.g., by producing antibodies. Contrast with passive immunization.
Acute retroviral syndrome (ARS) - a combination of flu-like symptoms (e.g., fever, sore throat, skin rash, headache, nausea, muscle or joint pain) that accompanies primary (initial) HIV infection or occur shortly after infection. ARS is due to a cellular immune response that takes place before the immune system has had time to produce antibodies.
Acyclovir (Zovirax) - an antiviral drug used to treat herpes simplex virus types 1 and 2 and varicella-zoster virus infections. When used in combination with AZT, acyclovir has been shown in some studies to prolong survival in persons with HIV disease.
Alternative medicine - a broad category of treatment systems (e.g., chiropractic, herbal medicine, acupuncture, homeopathy, naturopathy, and spiritual devotions) or culturally based healing traditions such as Chinese, Ayurvedic, and Christian Science. Alternative medicines share the common characteristic of non acceptance by the biomedical (i.e., mainstream Western) establishment. Alternative medicine is also referred to as "complementary medicine."
Antiretroviral drugs - Substances used to kill or inhibit the multiplication of retroviruses such as HIV.
B lymphocytes - One of the two major classes of lymphocytes, B lymphocytes are blood cells of the immune system, derived from the bone marrow and spleen; they are involved in the production of antibodies. During infections, these cells are transformed into plasma cells that produce large quantities of antibody directed at specific pathogens. When antibodies bind to foreign proteins, such as those that occur naturally on the surfaces of bacteria, they mark the foreign cells for consumption by other cells of the immune system. This transformation occurs through interactions with various types of T cells and other components of the immune system. In persons living 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 HIV.
Biotechnology - 1. Use of living organisms or their products to make or modify a substance. These include recombinant DNA techniques (genetic engineering). 2. 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.
Body fluids - Any fluid in the human body, such as blood, urine, saliva (spit), sputum, 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 HIV.
CD4 (T4) or CD4+ cells - 1. A type of T cell involved in protecting against viral, fungal, and protozoal infections. 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 for developing opportunistic infections. 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 CD8 (T8) Cells; Immunodeficiency.
Centers for Disease control and prevention - The U.S. Department of Health and Human Services agency with the mission to promote health and quality of life by preventing and controlling disease, injury, and disability. CDC operates 11 Centers including the National Center for HIV, STD, and TB Prevention. CDC assesses the status and characteristics of the HIV epidemic and conducts epidemiologic, laboratory, and surveillance investigations. http://www.cdc.gov
Central nervous system - The central nervous system is composed of the brain, spinal cord, and meninges (protective membranes surrounding them).
Co-receptors - A group of proteins that have been found to block the entry of HIV into immune cells.
Cofactors - 1. Substances, micro-organisms, 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 cofactors are other infections, drug and alcohol use, poor nutrition, genetic factors, and stress. In HIV immunology, the concept of cofactors is being expanded and new cofactors have been identified. A recent example is the discovery of the interaction of CXCR4 (fusin) and CD4 to facilitate entry of HIV into cells.
Complement - A group of proteins in normal blood serum and plasma that, in combination with antibodies, causes the destruction of antigens, particularly bacteria and foreign blood cells.
Contagious - In the context of HIV, has come to be more popularly known as any infectious disease capable of being transmitted by casual contact from person to another. Casual contact can be defined as normal day-to-day contact among people at home, school, work, or in the community. A contagious pathogen (e.g., chicken pox) can be transmitted by casual contact. An infectious pathogen, on the other hand, is transmitted by direct or intimate contact (e.g., sex). HIV is infectious, not contagious.
Endemic - Pertaining to diseases associated with particular locales or population groups.
Endogeneous - Relating to or produced by the body.
Enteritis - Inflammation of the intestine.
Entry inhibitors - Compounds designed to disrupt the interactions between the HIV virus and the cell surface. These compounds can block or prevent binding to human cell surface receptions (CD4, CCR5, and CXCR4, for instance), or prevent fusion of the HIV virus to the cell. No drugs that employ these mechanisms have been approved by the FDA. Some compounds are in clinical trials.
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.
Erythema - Redness or inflammation of the skin or mucous membranes.
Erythrocytes - Red blood cells whose major function is to carry oxygen to cells.
Gene - 1. A unit of DNA that carries information for the biosynthesis of a specific product in the cell. 2. Ultimate unit by which inheritable characteristics are transmitted to succeeding generations in all living organisms. Genes are contained by, and arranged along the length of, the chromosome. Alteration of either gene number or arrangement can result in mutation (a change in the inheritable traits).
Genetic engineering - The technique by which genetic material from one organism is inserted into a foreign cell in order to mass-produce the protein encoded by the inserted genes. This relatively new technique manipulates the DNA (genetic material) of cells. For example, in this technique, the genes, which are actually portions of molecules of DNA, are removed from the donor organism (insect, plant, mammal, or other organism) and spliced into the genetic material of a virus; the virus is then allowed to infect recipient bacteria. In this way the bacteria become recipients of both viral and foreign genetic material.
Granulocyte - A type of white blood cell filled with granules of compounds that digest micro-organisms. Granulocytes are part of the innate immune system and have broad-based activity.
Hematocrit - A laboratory measurement that determines the percentage of packed red blood cells in a given volume of blood. In women, red blood cells are normally 37 to 47 percent of their blood, and in men, red blood cells are normally 40 to 54 percent of their blood.
Hemoglobin - The component of red blood cells that carries oxygen.
Hemolysis - The rupture of red blood cells.
Hepatitis C/Co infection with HIV - Approximately 40% of patients infected with HIV are also infected with the hepatitis C virus (HCV), mainly because both viruses share the same routes of transmission. HCV is one of most important causes of chronic liver disease in the U.S. It has been demonstrated in clinical studies that HIV infection causes a more rapid progression of chronic hepatitis C to cirrhosis and liver failure in HIV-infected persons.
HIV disease - During the initial infection with HIV, when the virus comes in contact with the mucosal surface and finds susceptible T cells, the first site at which there is truly massive production of the virus is lymphoid tissue. This leads to a burst of massive viremia, with wide dissemination of the virus to lymphoid organs. The resulting immune response to suppress the virus is only partially successful and some virus escape. Eventually, this results in high viral turnover that leads to destruction of the immune system. HIV disease is, therefore, characterized by a gradual deterioration of immune functions. During the course of infection, crucial immune cells, called CD4+ T cells, are disabled and killed, and their numbers progressively decline.
Holistic medicine - Healing traditions that promote the protection and restoration of health through theories reputedly based on the body's natural ability to heal itself and through manipulation of various ways body components affect each other and are influenced by the external environment.
Hormone - An active chemical substance formed in one part of the body and carried in the blood to other parts of the body where it stimulates or suppresses cell and tissue activity.
HIV type-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. 2. 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 factory.
HIV type-2 - A virus closely related to HIV-1 that has also been found to cause AIDS. It was first isolated in West Africa. Although HIV-1 and HIV-2 are similar in their viral structure, modes of transmission, and resulting opportunistic infections, they have differed in their geographic patterns of infection.
Human leukocyte antigens (HLA) - Marker molecules on cell surfaces that identify cells as "self" and prevent the immune system from attacking them.
Immune system - The body's complicated natural defense against disruption caused by invading foreign agents (e.g., microbes, viruses). There are two aspects of the immune system's response to disease: innate and acquired. The innate part of the response is mobilized very quickly in response to infection and does not depend on recognizing specific proteins or antigens foreign to an individual's normal tissue. It includes complements, macrophages, dendritic cells, and granulocytes. The acquired, or learned, immune response arises when dendritic cells and macrophages present pieces of antigen to lymphocytes, which are genetically programmed to recognize very specific amino acid sequences. The ultimate result is the creation of cloned populations of antibody-producing B cells and cytotoxic T lymphocytes primed to respond to a unique pathogen.
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.
Incubation period - The time interval between the initial infection with a pathogen (e.g., HIV) and the appearance of the first symptom or sign of disease.
Infection - 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.
Lipid - Any of a group of fats and fatlike compounds, including sterols, fatty acids, and many other substances.
Mucous membrane - Moist layer of tissue lining the digestive, respiratory, urinary, and reproductive tracts-all the body cavities with openings to the outside world except the ears.
Natural killer cells - A type of lymphocyte. Like cytotoxic T cells, NK cells 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 immunodeficiencies such as those caused by HIV infection have a decrease in natural killer cell activity.
NEF - One of the regulatory genes of HIV. Three HIV regulatory genes-tat, rev, and nef-and three so-called auxiliary genes-vif, vpr, and vpu-contain information necessary for the production of proteins that control the virus; ability to infect a cell, produce new copies of itself, or cause disease.
Opportunistic infections - Illnesses caused by various organisms, some of which usually do not cause disease in persons with normal immune systems. Persons living with advanced HIV infection suffer opportunistic infections of the lungs, brain, eyes, and other organs. Opportunistic infections common in persons diagnosed with AIDS include Pneumocystis carinii pneumonia; Kaposi's Sarcoma; cryptosporidiosis; histoplasmosis; other parasitic, viral, and fungal infections; and some types of cancers.
Palliative care - Palliative care is an approach to life- threatening chronic illnesses, especially at the end of life. Palliative care combines active and compassionate therapies to comfort and support patients and their families who are living with life-ending illness. Palliative care strives to meet physical needs through pain relief and maintaining quality of life while emphasizing the patient's and family's rights to participate in informed discussion and to make choices. This patient- and family-centered approach uses the skills of interdisciplinary team members to provide a comprehensive continuum of care including spiritual and emotional needs.
Passive immunity - Also referred to as acquired immunity. Resistance resulting from previous exposure to an infectious agent or antigen may be active or passive. Passive immunity can be acquired from the transfer of antibodies from another person or from an animal, either naturally-as from mother to fetus or to the newborn via breast milk-or by intentional inoculation (vaccination).
Perinatal transmission - Transmission of a pathogen, such as HIV, from mother to baby before, during, or after the birth process. Ninety percent of children reported with AIDS acquired HIV infection from their HIV-infected mothers.
Placebo controlled study - A method of investigation of drugs in which an inactive substance (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 to see if the investigational treatment is more effective in treating the condition.
Regulatory T-cells - T cells that direct other immune cells to perform special functions. The chief regulatory cell, the CD4+ T cell or T helper cell, is the chief target of HIV.
Retinitis - Inflammation of the retina, linked in AIDS to cytomegalovirus (CMV) infection. Untreated, it can lead to blindness.
Retrovirus - A type of virus that, when not infecting a cell, stores its genetic information on a single-stranded RNA molecule instead of the more usual double-stranded DNA. HIV is an example of a retrovirus. After a retrovirus penetrates a cell, it constructs a DNA version of its genes using a special enzyme called reverse transcriptase. This DNA then becomes part of the cell's genetic material.
Rev - One of the regulatory genes of HIV. Three HIV regulatory genes-tat, rev, and nef -and three so-called auxiliary genes-vif, vpr, and vpu-contain information necessary for the production of proteins that control the virus's ability to infect a cell, produce new copies of the virus, or cause disease.
Sepsis - The presence of harmful micro-organisms or associated toxins in the blood.
Seroconversion - The development of antibodies to a particular antigen. When people develop antibodies to HIV, they seroconvert from antibody-negative to antibody-positive. It may take from as little as 1 week to several months or more after infection with HIV for antibodies to the virus to develop. After antibodies to HIV appear in the blood, a person should test positive on antibody tests.
Serologic test - Any number of tests that are performed on the clear fluid portion of blood. Often refers to a test that determines the presence of antibodies to antigens such as viruses.
Serum - The clear, thin, and sticky fluid portion of the blood that remains after coagulation (clotting). Serum contains no blood cells, platelets, or fibrinogen.
Sexually transmitted disease (STD) - Also called venereal disease (VD) (an older public health term) or sexually transmitted infections (STIs). Sexually transmitted diseases are infections spread by the transfer of organisms from person to person during sexual contact. In addition to the "traditional" STDs (syphilis and gonorrhea), the spectrum of STDs now includes HIV infection, which causes AIDS; Chlamydia trachomatis infections; human papilloma virus (HPV) infection; genital herpes; chancroid; genital mycoplasmas; hepatitis B; trichomoniasis; enteric infections; and ectoparasitic diseases (i.e., diseases caused by organisms that live on the outside of the host's body). The complexity and scope of STDs have increased dramatically since the 1980s; more than 20 micro-organisms and syndromes are now recognized as belonging in this category.
Side effects - The actions or effects of a drug (or vaccine) other than those 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.
Syphilis - A primarily sexually transmitted disease resulting from infection with the spirochete (a bacterium), Treponema pallidum. Syphilis can also be acquired in the uterus during pregnancy.
Systemic - Concerning or affecting the body as a whole. A systemic therapy is one that the entire body is exposed to, rather than just the target tissues affected by a disease.
T cells or(T Lymphocytes) - T cells are white blood cells derived from the thymus gland that participate in a variety of cell-mediated immune reactions. Three fundamentally different types of T cells are recognized helper, killer, and suppressor. They are the immune system's "border police," responsible for finding infected or cancerous cells. The killer T cell receptors (TCR) bind to an infected cell's distress signal-a combination of one of the cell's own proteins and a tiny fragment of the invader's protein. The bits of foreign protein are made with the help of enzymes inside the infected cell that break down the pathogens into protein fragments (peptides), which are then picked up by the major histocompatibility
Therapeutic HIV vaccine - Also called treatment vaccine. A vaccine designed to boost the immune response to HIV infection. A therapeutic vaccine is different from a preventive vaccine, which is designed to prevent an infection or disease from becoming established in a person.
Tubercolisis - A bacterial infection caused by Mycobacterium tuberculosis. TB bacteria are spread by airborne droplets expelled from the lungs when a person with active TB coughs, sneezes, or speaks. Exposure to these droplets can lead to infection in the air sacs of the lungs. The immune defenses of healthy people usually prevent TB infection from spreading beyond a very small area of the lungs. If the body's immune system is impaired because of HIV infection, aging, malnutrition, or other factors, the TB bacterium may begin to spread more widely in the lungs or to other tissues. TB is seen with increasing frequency among HIV-infected persons. Most cases of TB occur in the lungs (pulmonary TB). However, the disease may also occur in the larynx, lymph nodes, brain, kidneys, or bones (extrapulmonary TB). Extrapulmonary TB infections are more common among persons living with HIV. See Multiple Drug Resistant TB.
Vaccine - A substance that contains antigenic components from an infectious micro-organism. By stimulating an immune response -but not the disease-it protects against subsequent infection by that organism. There can be preventive vaccines (e.g., measles or mumps) as well as therapeutic (treatment) vaccines.
Vertical transmission - Transmission of a pathogen such as HIV from mother to fetus or baby during pregnancy or birth.
Viricide - Any agent that destroys or inactivates a virus.
Virus - Organism composed mainly of nucleic acid within a protein coat. When viruses enter a living plant, animal, or bacterial cell, they make use of the host cell's chemical energy, protein, and nucleic acid-synthesizing ability to replicate themselves. After the infected host cell makes viral components and 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. In humans, viruses cause measles, mumps, yellow fever, poliomyelitis, influenza, and the common cold, among others. Some viral infections can be treated with drugs.
Window period - Time from infection with HIV until antibodies are detected.
(source : http://glossary.hivatis.org/index.asp ; http://www.sfaf.org/treatment/glossary/)