Complement cascade – Definition, Deficiencies

Complement Cascade Definition Complement Cascade is  the series of events that take place when an ANTIBODY binds with an ANTIGEN, activating the complements. Complements are proteins that participate in immune and inflammatory processes, acting primarily to kill antibody-marked cells. The biochemical interactions that take place with their activation ultimately lead to the formation of a protein structure called […]

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Major histocompatability complex (MHC) – class I, II, III

Major Histocompatability Complex Definition and Types Major Histocompatability Complex Definition (MHC) – The group of genes, located on chromosome 6, that determine the HUMAN LEUKOCYTE ANTIGENS (HLAS) the body’s cells carry on their cell membranes. HLAs are unique proteins that cell membranes display to identify themselves to the IMMUNE SYSTEM. There are three types of MHC: Class I MHC […]

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Cytokines definition

Definition of Cytokines A large family of proteins that mediate and regulate the IMMUNE RESPONSE. Leukocytes (white BLOOD cells) produce this proteins. There are more than 100 cytokines, which may act independently or synergistically with others. Among the actions of cytokines are cell homing and direction (drawing leukocytes to the site of INFECTION or injury), INFLAMMATION response, and stimulation of the numerous […]

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Monoclonal antibodies (MAbs)

Monoclonal Antibodies Definition Antibodies produced in a laboratory using RECOMBINANT DNA technology. MAbs derive from cloned mouse SPLEEN cells (hence the designation “monoclonal”) containing the desired ANTIBODY fused with human myeloma cells. Mouse cells have proteins very similar to the proteins of human cells. Human myeloma cells, because they are cancer cells, have the ability to replicate […]

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Gammaglobulin – definition

What is Gammaglobulin and Definition Gammaglobulin – a solution of immunoglobulins collected from the PLASMA of donated BLOOD or from donated plasma. The highest concentration is of IMMUNOGLOBULIN E (IgE). Health-care providers administer gammaglobulin by intramuscular or intravenous injection to provide rapid immune protection for exposure to infectious diseases such as HEPATITIS. Though the protection is temporary, it helps prevent INFECTION until the […]

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Monokines – Definition

Monokines Definition CYTOKINES that convey biochemical messages among monocytes (white blood cells in the blood circulation) and macrophages (white blood cells that reside in the tissues). Monokines direct the actions of these immune cells during the IMMUNE RESPONSE, stimulating and coordinating numerous functions. There is some overlap between monokines and LYMPHOKINES (which lymphocytes produce). See also COMPLEMENT CASCADE; IMMUNE SYSTEM; INTERFERONS; INTERLEUKINS; LEUKOCYTE; […]

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Gut-associated lymphoid tissue (GALT)

Gut-Associated Lymphoid Tissue Definition Loosely organized, nonencapsulated clusters of LYMPH tissue beneath the epithelium (tissue that forms the mucous lining) of the gastrointestinal tract from the ESOPHAGUS to the COLON. T-cell lymphocytes, Bcell lymphocytes, and macrophages primarily inhabit Gut-Associated Lymphoid Tissue (GALT). The role of GALT is to block NORMAL FLORA BACTERIA (bacteria that are normally present […]

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Mononuclear phagocyte system

Mononuclear phagocyte system Definition and Function The combined activity of the IMMUNE SYSTEM’s phagocytes-monocytes in the blood circulation and macrophages in the tissues-to consume cellular debris. These cells are scavengers within the body, responsible for cleaning up after B-cell lymphocytes, T-cell lymphocytes, and natural killer (NK) cells. They also clear the debris that results from normal cell […]

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The Immune System and Allergies

The Immune System Definition The IMMUNE SYSTEM protects the body from INFECTION. Allergies represent an inappropriate response from the immune system toward harmless substances. Doctors (MDs and DOs) who treat conditions of the immune system may be internists or immunologists. Doctors who specialize in treating allergies are allergists, and those who specialize in treating RHEUMATOID […]

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Histamine and Histamine Receptors – Definition, types

Histamine and Histamine Receptors Definition A chemical that acts as an IMMUNE RESPONSE mediator. Large, granulated leukocytes called mast cells, which reside in the mucous membrane lining of the respiratory and gastrointestinal tracts, store histamine in their granules and release it during the immune response. Mast cells are most abundant in the nasal passages (including the SINUSES), […]

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