[HOME] [FUN SITE] Good Sites A_ B_ C_ D_ E_ F_ G_ H_ I_ J_ K_ L_ M_ N_ O_ P_ Q_ R_ S_ T_ U_ V_ W_ X_ Y_ Z_ Other_ Back to AIDS Prevention Home AIDS Glossary n.r. (non rep.) pharmaceutical abbreviation,  do not repeat (non repetatur) nac see a substance which is converted within the body to cysteine, an amino acid that is a component of glutathione, a major cellular antioxidant. NAC may block the action of tumor necrosis factor. n-acetylcysteine see NAC naive inexperienced. The term is used to describe an individual who has never taken a certain drug or class of drugs (e.g., AZT-naive, antiretroviral-naive), or to refer to an undifferentiated immune system cell. naive t-cell a subset of CD4 and CD8 cells that proliferate rapidly when exposed to new antigens. Naive cells are "uncommitted" and respond to general antigenic stimulation (i.e., not only to a specific antigen). A naive T-cell is not yet "programmed" to stimulate either a cell-mediated (TH1) or a humoral (TH2) response. naltrexone (revia, trexan) a drug used to treat opiate (e.g., heroin) addiction and alcoholism. Naltrexone blocks the opiate receptors, preventing cells from responding to opiate drugs and endorphins. Naltrexone has been used as an immune modulator by some people with HIV disease. narcotic see opioid. nasba see nucleic acid sequence-based amplification. natal relating to birth. national cancer institute (nci) a U.S. government sponsored research agency, part of the National Institutes of Health, that deals with malignant diseases. national institute of allergy and infectious disea a component of the National Institutes of Health that conducts federally-funded research aimed at preventing, diagnosing and treating infectious diseases such as AIDS and tuberculosis. NIAID conducts the majority of HIV/AIDS research in the U.S., including the AIDS Clinical Trials Group (ACTG), Community Programs for Clinical Research on AIDS (CPCRA) and the AIDS Vaccine Evaluation Group (AVEG). national institutes of health (nih) a large biomedical research organization that is part of the U.S. Public Health Service (PHS). NIH includes various institutes, centers and divisions, several of which (e.g., NIAID) perform AIDS-related research. national science foundation (nsf) the agency of the U.S. federal government that coordinates and funds scientific and technological research, including medical research. national task force on aids drug development a task force of the Department of Health and Human Services commissioned by the president to study obstacles to AIDS drug development and formulate ways to overcome them. natural history study a study of the development of a disease over the course of time. natural killer cell (nk cell) a type of lymphocyte that attacks and kills tumor cells and cells infected with microorganisms. Unlike cytotoxic T-lymphocytes, NK cells are nonspecific and attack infected cells without regard to specific antigens or MHC receptor configuration. natural killer cells (nk) a lymphocyte (white blood cell) that attacks and destroys infected or cancer-causing cells without antigen stimulation. naturopathy a alternative system of natural healing that relies on healthy foods and exercise, and the avoidance of drugs, believing that the body can cure itself. nci see National Cancer Institute. nda see new drug application. nebulizer a device used to convert liquid medication to a fine mist that can be inhaled. necrosis localized tissue death. nef a gene of HIV that influences viral replication; also the protein produced by that gene. nelfinavir (viracept, formerly ag1343) a protease inhibitor drug currently in clinical trials. neo- prefix, new, recent. neonate (adjective neonatal) a newborn, especially within the first weeks after birth. neoplasia abnormal cell growth that may be precancerous. neoplasm abnormal new growth in plant or animal tissue, a tumor. neopterin a substance produced by macrophage cells when they find a foreign substance in the blood stream. Neopterin alerts other cells to take action against the intruder. Measuring neopterin is one way of finding out how well the immune system is working. nephro-, neph- prefix, kidney. nephrolithiasis see kidney stone. nephrotoxicity the property of being poisonous to the kidneys; many drugs have nephrotoxic side effects. nerve a cordlike structure composed of fibers that conduct impulses between the central nervous system and other part of the body. A nerve cell is a neuron, or cell that conducts neural impulses. nerve growth factor (ngf) one of a family of proteins that nourish and sustain neurons. neural relating to a neuron, a nerve or the nervous system. neuralgia pain along a nerve pathway. neuritis inflammation of the nerves, typically accompanied by symptoms of pain and tenderness. neuro-,neur- prefix, pertaining to the central nervous system (brain, spinal cord) neuroimaging examination of the brain by external methods (e.g., magnetic resonance imaging, CT scan). neuroleptic a drug that acts on the nervous system and modifies psychotic behavior. neurologic pertaining to the central nervous system (brain and spinal cord) or the peripheral nervous system (the nerves in the rest of the body). neurology the branch of medicine concerned with the nervous system and its disorders. neuron (nerve cell) a cell which conducts electric neural impulses from one part of the body to another. Neurons are made up of dendrites (branch-like fibers which receive impulses) and axons (fibers which transmit impulses), and communicate with other neurons and effector organs at junctures called synapses. neuropathy any disease, inflamation, or abnormality of a nerve. neuropathy (adjective neuropathic) damage to the nerves; an inflammatory or degenerative condition of the nervous system. See also peripheral neuropathy. neuropharmacologic relating to drugs that affect the nervous system. neuropsychological relating to both physical and psychological aspects of the brain. neuroradiology (neuroradiography) the study or diagnosis of parts of the nervous system using X-rays. neurosyphilis a late form of syphilis that affects the brain and may lead to dementia and death. neurotoxicity the quality of being destructive of or poisonous to the tissues of the nervous system. neurotransmitter a chemical messenger (e.g., dopamine, serotonin) used to communicate among neurons and between neurons and other types of cells. neutralization a process whereby antibodies bind to an antigen (e.g., HIV) to prevent infectious or toxic processes. neutralizing antibody an antibody that neutralizes (renders harmless) infectious microorganisms. Neutralizing antibodies to HIV block the ability of the virus to infect cells. Contrast with enhancing antibody. neutrexin brand name of trimetrexate. neutropenia A low number of neutrophils in the blood. Neutrophils are a white blood cell important in defending the body against infections. neutrophil a white blood cell (granulocytes) that is filled with chemicals that can destroy (digest) microorganisms. These cells are the body's front line defense against bacterial infection. nevirapine (viramune, formerly birg-587) a non-nucleoside reverse transcriptase inhibitor drug approved for the treatment of HIV disease. Nevirapine blocks HIV replication by binding to the reverse transcriptase enzyme. Side effects include rash and liver toxicity. new drug application (nda) an application made by a drug manufacturer to FDA requesting marketing approval of a new drug. nf-kappa b (nf-kb) nuclear factor kappa B, a regulatory protein that functions to increase cellular metabolic activity and cell division. Certain HIV genes contain receptors for NF-kB, which may induce increased HIV gene expression and thus viral replication. ngo see non-governmental organization. nhl abbreviation,  non-Hodgkin's lymphoma, a rare cancer that affects B-cells in the lymph system. niacin a vitamin needed for the metabolism of proteins, carbohydrates and fats. Signs of niacin deficiency include weakness, headache, skin rash and diarrhea. niaid see National Institute of Allergy and Infectious Disease. night sweats abnormal sweating during sleep. nih see National Institutes of Health. nitric oxide a reactive oxygen intermediate (free radical) that has several biological functions. nitrite inhalant (poppers) a volatile (easily evaporated) chemical preparation with vasodilating (blood vessel expanding) properties. Some forms (e.g., amyl nitrite, isobutyl nitrite, or Rush) may be used recreationally to enhance sexual sensation. Some studies have linked inhalant use to immunosuppression, and they were previously regarded by some as a cofactor for AIDS and/or Kaposi's sarcoma. nizoral brand name of ketoconazole. nk cell see natural killer cell. nk cells See natural killer cells. nnrti see non-nucleoside reverse-transcriptase inhibitor. nociception the perception of pain or injury. A nociceptor is a pain receptor. nodule (nodular lesion) a hard, raised area of the skin or a mucous membrane; a knot or swelling. nongonoccocal cervicitis (ngu) inflammation of the uterine cervix caused by an organism other than Neisseria gonorrhoeae (e.g., Chlamydia trachomatis, Trichomonas vaginalis). nongonoccocal urethritis (ngu) inflammation of the urethra caused by an organism other than Neisseria gonorrhoeae. non-governmental organization (ngo) an international organization that is not run by a government. Many international public health groups are NGO. non-hodgkin's lymphoma a rare cancer -- sometimes abbreviated as NHL -- that affects B-cells in the lymph system. non-hodgkins lymphoma (nhl) a type of cancer of the lymph nodes. NHL is characterized by abnormal growth of B-cells, and is the most common type of lymphoma in people with HIV/AIDS. See also Hodgkins disease, lymphoma. non-nucleoside reverse transcriptase inhibitor (nn a drug (e.g., nevirapine, delavirdine) that inhibits the action of the HIV-1 reverse transcriptase enzyme, thus blocking HIV replication, yet works in a different way than nucleoside analog drugs, by binding with the RT enzyme. nonopioid analgesic a pain reliever (e.g., aspirin, ibuprofen) that is not derived from opium and does not have opium-like characteristics and effects. nonoxynol-9 a surfactant chemical that is used as a spermicide and microbicide (e.g., in contraceptive foams, as a lubricant on condoms). non-specific immunity immune system function (e.g., phagocytosis) that is not directed toward a specific antigen or pathogen. Contrast with specific immunity. non-steroidal anti-inflammatory drug (nsaid) a drug (e.g., aspirin, ibuprofen) that relieves pain and reduces inflammation and fever, but which is not a steroid or a narcotic. norplant a progesterone-releasing contraceptive that is embedded under the skin of the upper arm. norvir brand name of ritonavir. nosocomial refers to the acquisition of a new disease or condition within a healthcare setting, for example a hospital-acquired infection. See also iatrogenic. nsaid see non-steroidal anti-inflammatory drug. nsf see National Science Foundation. nsi non-syncytium-inducing strain of HIV. See syncytium. nuclease an enzyme (or group of enzymes) which split nucleic acids into different products. nucleic acid DNA and RNA, molecules made up of nucleotides that carry genetic information. nucleic acid base one of the components that make up the genetic material; in combination with sugar and phosphate groups they form nucleotides, the "building blocks" of DNA and RNA. There are two types of bases, purines (adenine and guanine) and pyrmidines (cytosine, thymine and uracil). Bases are complementary and can bind with their counterpart in a process known as base-pairing. nucleic acid sequence-based amplification (nasba) an load assay for detecting HIV viral load in blood plasma. NASBA amplifies RNA rather than DNA. nucleoside a precursor compound that is a converted to a nucleotide by the addition of a phosphate group. nucleoside analog (na) a compound (e.g., AZT, ddI, ddC, d4T, 3TC) that mimics one of the building blocks of DNA and RNA. These compounds suppress retroviral replication by interfering with the reverse transcriptase enzyme. The defective synthetic nucleosides cause premature termination of the viral DNA chain. Nucleoside analogs are prodrugs that are converted into active agents by phosphorylation. nucleotide (deoxyribonucleotide, ribonucleotide) one of the building blocks that make up the genetic material (DNA and RNA). Nucleotides consist of a base (adenine, cytosine, guanine, thymine or uracil), a sugar and a phosphate group. nucleotide analog a compound (e.g., cidofovir, PMPA), similar to a nucleoside analog, which is already "primed" with an extra phosphate group and ready to be added to a DNA chain. The defective synthetic nucleotide interferes with viral replication by causing premature termination of the viral DNA chain. nucleus central part of a cell which contains its genetic material. nutrient any item that nourishes or promotes growth and metabolism. Nutrients act as cofactors in many vital physiological processes. nutrition the processes involved in ingesting and metabolizing food material by living plants and animals. nystatin (mycostatin) a topical treatment for candidiasis (thrush). Search: All Products Books Magazines Popular Music Classical Music Video DVD Toys & Games Baby Computer & Video Games Electronics Software Tools & Hardware Outdoor Living Kitchen & Housewares Camera & Photo Wireless Phones Keywords: