Từ điển y khoa
Thuật ngữ y khoa chuẩn hóa theo MeSH, ICD-11, SNOMED CT.
62,341 terms indexed
The process by which antigen is presented to lymphocytes in a form they can recognize. This is performed by antigen presenting cells (APCs). Some antigens require processing before they can be recognized. Antigen processing consists of ingestion and partial digestion of the antigen by the APC, followed by presentation of fragments on the cell surface. (From Rosen et al., Dictionary of Immunology, 1989)
The complex formed by the binding of antigen and antibody molecules. The deposition of large antigen-antibody complexes leading to tissue damage causes IMMUNE COMPLEX DISEASES.
The processes triggered by interactions of ANTIBODIES with their ANTIGENS.
A heterogeneous group of immunocompetent cells that mediate the cellular immune response by processing and presenting antigens to the T-cells. Traditional antigen-presenting cells include MACROPHAGES; DENDRITIC CELLS; LANGERHANS CELLS; and B-LYMPHOCYTES. FOLLICULAR DENDRITIC CELLS are not traditional antigen-presenting cells, but because they hold antigen on their cell surface in the form of IMMUNE COMPLEXES for B-cell recognition they are considered so by some authors.
Loss of detectable antigen from the surface of a cell after incubation with antibodies. This is one method in which some tumors escape detection by the immune system. Antigenic modulation of target antigens also reduces the therapeutic effectiveness of treatment by monoclonal antibodies.
Change in the surface ANTIGEN of a microorganism. There are two different types. One is a phenomenon, especially associated with INFLUENZA VIRUSES, where they undergo spontaneous variation both as slow antigenic drift and sudden emergence of new strains (antigenic shift). The second type is when certain PARASITES, especially trypanosomes, PLASMODIUM, and BORRELIA, survive the immune response of the host by changing the surface coat (antigen switching). (From Herbert et al., The Dictionary of Immunology, 4th ed)
Substances that are recognized by the immune system and induce an immune reaction.
Substances of archaeal origin that have antigenic activity.
Substances elaborated by bacteria that have antigenic activity.
Differentiation antigens residing on mammalian leukocytes. CD stands for cluster of differentiation, which refers to groups of monoclonal antibodies that show similar reactivity with certain subpopulations of antigens of a particular lineage or differentiation stage. The subpopulations of antigens are also known by the same CD designation.
Glycoproteins expressed on cortical thymocytes and on some dendritic cells and B-cells. Their structure is similar to that of MHC Class I and their function has been postulated as similar also. CD1 antigens are highly specific markers for human LANGERHANS CELLS.
Differentiation antigens expressed on B-lymphocytes and B-cell precursors. They are involved in regulation of B-cell proliferation.
A major histocompatibility complex class I-like protein that contains an IMMUNOGLOBULIN C1-SET DOMAIN. It plays a unique role in the presentation of lipid ANTIGENS to NATURAL KILLER T-CELLS.
Unglycosylated phosphoproteins expressed only on B-cells. They are regulators of transmembrane Ca2+ conductance and thought to play a role in B-cell activation and proliferation.
Glycoproteins found on immature hematopoietic cells and endothelial cells. They are the only molecules to date whose expression within the blood system is restricted to a small number of progenitor cells in the bone marrow.
Differentiation antigens expressed on pluripotential hematopoietic cells, most human thymocytes, and a major subset of peripheral blood T-lymphocytes. They have been implicated in integrin-mediated cellular adhesion and as signalling receptors on T-cells.
Antigens from the house dust mites (DERMATOPHAGOIDES), mainly D. farinae and D. pteronyssinus. They are proteins, found in mite feces or mite extracts, that can cause ASTHMA and other allergic diseases such as perennial rhinitis (RHINITIS, ALLERGIC, PERENNIAL) and atopic dermatitis (DERMATITIS, ATOPIC). More than 11 groups of Dermatophagoides ALLERGENS have been defined. Group I allergens, such as Der f I and Der p I from the above two species, are among the strongest mite immunogens in humans.
Antigens expressed primarily on the membranes of living cells during sequential stages of maturation and differentiation. As immunologic markers they have high organ and tissue specificity and are useful as probes in studies of normal cell development as well as neoplastic transformation.
Membrane antigens associated with maturation stages of B-lymphocytes, often expressed in tumors of B-cell origin.
Surface antigens expressed on myeloid cells of the granulocyte-monocyte-histiocyte series during differentiation. Analysis of their reactivity in normal and malignant myelomonocytic cells is useful in identifying and classifying human leukemias and lymphomas.
Antigens expressed on the cell membrane of T-lymphocytes during differentiation, activation, and normal and neoplastic transformation. Their phenotypic characterization is important in differential diagnosis and studies of thymic ontogeny and T-cell function.
Substances of fungal origin that have antigenic activity.
Any part or derivative of a helminth that elicits an immune reaction. The most commonly seen helminth antigens are those of the schistosomes.
Antigens stimulating the formation of, or combining with heterophile antibodies. They are cross-reacting antigens found in phylogenetically unrelated species.
Human alloantigens expressed only on platelets, specifically on platelet membrane glycoproteins. These platelet-specific antigens are immunogenic and can result in pathological reactions to transfusion therapy.
A group of lymphocyte surface antigens located on mouse LYMPHOCYTES. Specific Ly antigens are useful markers for distinguishing subpopulations of lymphocytes.
Newly formed ANTIGENS that arise from mutations in tumor cells. These antigens are specific to cancer cells and absent in normal tissues.
Immunologically detectable substances found in the CELL NUCLEUS.
Substances found in PLANTS that have antigenic activity.
Polyomavirus antigens which cause infection and cellular transformation. The large T antigen is necessary for the initiation of viral DNA synthesis, repression of transcription of the early region and is responsible in conjunction with the middle T antigen for the transformation of primary cells. Small T antigen is necessary for the completion of the productive infection cycle.
Any part or derivative of any protozoan that elicits immunity; malaria (Plasmodium) and trypanosome antigens are presently the most frequently encountered.
Antigens on surfaces of cells, including infectious or foreign cells or viruses. They are usually protein-containing groups on cell membranes or walls and may be isolated.
Antigens which may directly stimulate B lymphocytes without the cooperation of T lymphocytes.
Carbohydrate antigens expressed by malignant tissue. They are useful as tumor markers and are measured in the serum by means of a radioimmunoassay employing monoclonal antibodies.
Substances elaborated by viruses that have antigenic activity.
Those proteins recognized by antibodies from serum of animals bearing tumors induced by viruses; these proteins are presumably coded for by the nucleic acids of the same viruses that caused the neoplastic transformation.
Islands in the Lesser Antilles, within the Leeward Islands. ANTIGUA, BARBUDA, and Redonda, an uninhabited island, constitute the independent state of ANTIGUA AND BARBUDA. The capital is St. Johns.
Compounds used to lower excessive POTASSIUM levels in the body.
Drugs used in the treatment of acute or chronic vascular HYPERTENSION regardless of pharmacological mechanism. Among the antihypertensive agents are DIURETICS; (especially DIURETICS, THIAZIDE); ADRENERGIC BETA-ANTAGONISTS; ADRENERGIC ALPHA-ANTAGONISTS; ANGIOTENSIN-CONVERTING ENZYME INHIBITORS; CALCIUM CHANNEL BLOCKERS; GANGLIONIC BLOCKERS; and VASODILATOR AGENTS.
Serum containing GAMMA-GLOBULINS which are antibodies for lymphocyte ANTIGENS. It is used both as a test for HISTOCOMPATIBILITY and therapeutically in TRANSPLANTATION.
Agents used in the treatment of malaria. They are usually classified on the basis of their action against plasmodia at different stages in their life cycle in the human. (From AMA, Drug Evaluations Annual, 1992, p1585)
Agents that are used to treat bipolar disorders or mania associated with other affective disorders.
Drugs that are chemically similar to naturally occurring metabolites, but differ enough to interfere with normal metabolic pathways. (From AMA Drug Evaluations Annual, 1994, p2033)
Antimetabolites that are useful in cancer chemotherapy.
Small cationic peptides that are an important component, in most species, of early innate and induced defenses against invading microbes. In animals they are found on mucosal surfaces, within phagocytic granules, and on the surface of the body. They are also found in insects and plants. Among others, this group includes the DEFENSINS, protegrins, tachyplesins, and thionins. They displace DIVALENT CATIONS from phosphate groups of MEMBRANE LIPIDS leading to disruption of the membrane.
Agents that arrest cells in MITOSIS, most notably TUBULIN MODULATORS.
A metallic element that has the atomic symbol Sb, atomic number 51, and atomic weight 121.75. It is used as a metal alloy and as medicinal and poisonous salts. It is toxic and an irritant to the skin and the mucous membranes.
A schistosomicide possibly useful against other parasites. It has irritant emetic properties and may cause lethal cardiac toxicity among other adverse effects.
Antimony complex where the metal may exist in either the pentavalent or trivalent states. The pentavalent gluconate is used in leishmaniasis. The trivalent gluconate is most frequently used in schistosomiasis.
Agents that reduce the frequency or rate of spontaneous or induced mutations independently of the mechanism involved.