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Mixed Lymphocyte Reaction
Mixed lymphocyte reaction (MLR) is a test used by pharmaceutical and biotech organizations to show the safety of a drug or implantable material. It is commonly used as part of the FDA clearance process. Put simply, it is mixing populations of T-lymphocytes (category of white blood cells) together, and measuring the reaction that occurs. Technically, it is an ex-vivo cellular immune assay that occurs between two allogeneic lymphocyte populations (same species but genetically distinct). In a one-way MLR, only one lymphocyte population can respond or proliferate. In a two-way MLR, both populations can proliferate. MLR’s are performed to assess how T-cells react to external stimuli. T cells are a type of white blood cell that scans for cellular abnormalities and infections. They are essential to human immunity. History & background The MLR was first recognized when researchers mixed leukocytes from two unrelated donors in culture. After several days, lymphocytes underwent blast tra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lymphocyte
A lymphocyte is a type of white blood cell (leukocyte) in the immune system of most vertebrates. Lymphocytes include natural killer cells (which function in cell-mediated, cytotoxic innate immunity), T cells (for cell-mediated, cytotoxic adaptive immunity), and B cells (for humoral, antibody-driven adaptive immunity). They are the main type of cell found in lymph, which prompted the name "lymphocyte". Lymphocytes make up between 18% and 42% of circulating white blood cells. Types The three major types of lymphocyte are T cells, B cells and natural killer (NK) cells. Lymphocytes can be identified by their large nucleus. T cells and B cells T cells (thymus cells) and B cells ( bone marrow- or bursa-derived cells) are the major cellular components of the adaptive immune response. T cells are involved in cell-mediated immunity, whereas B cells are primarily responsible for humoral immunity (relating to antibodies). The function of T cells and B cells is to recognize sp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Major Histocompatibility Complex
The major histocompatibility complex (MHC) is a large locus on vertebrate DNA containing a set of closely linked polymorphic genes that code for cell surface proteins essential for the adaptive immune system. These cell surface proteins are called MHC molecules. This locus got its name because it was discovered via the study of transplanted tissue compatibility. Later studies revealed that tissue rejection due to incompatibility is only a facet of the full function of MHC molecules: binding an antigen derived from self-proteins, or from pathogens, and bringing the antigen presentation to the cell surface for recognition by the appropriate T-cells. MHC molecules mediate the interactions of leukocytes, also called white blood cells (WBCs), with other leukocytes or with body cells. The MHC determines donor compatibility for organ transplant, as well as one's susceptibility to autoimmune diseases. In a cell, protein molecules of the host's own phenotype or of other biologic entities ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cell-mediated Immunity
Cell-mediated immunity or cellular immunity is an immune response that does not involve antibodies. Rather, cell-mediated immunity is the activation of phagocytes, antigen-specific cytotoxic T-lymphocytes, and the release of various cytokines in response to an antigen. History In the late 19th century Hippocratic tradition medicine system, the immune system was imagined into two branches: humoral immunity, for which the protective function of immunization could be found in the humor (cell-free bodily fluid or serum) and cellular immunity, for which the protective function of immunization was associated with cells. CD4 cells or helper T cells provide protection against different pathogens. Naive T cells, which are immature T cells that have yet to encounter an antigen, are converted into activated effector T cells after encountering antigen-presenting cells (APCs). These APCs, such as macrophages, dendritic cells, and B cells in some circumstances, load antigenic peptides ont ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thymectomy
A thymectomy is an operation to remove the thymus. It usually results in remission of myasthenia gravis with the help of medication including steroids. However, this remission may not be permanent. Thymectomy is indicated when thymoma are present in the thymus. Anecdotal evidence suggests MG patients with no evidence of thymoma may still benefit from thymectomy, thus the procedure is (unless and until a much-discussed clinical survey ever reaches a contradictory conclusion) commonly prescribed. Surgical approaches There are a number of surgical approaches to the removal of the thymus gland: transternal (through the Sternum, breast bone), transcervical (through a small neck incision), transthoracic (through one or both sides of the chest.) * The transternal approach is most common and uses the same length-wise incision through the sternum (breast bone) used for most open-heart surgery. It is espoused by surgeons such as Alfred Jaretzki and is the most commonly performed procedure ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bursectomy
A bursectomy is the removal of a bursa, which is a small sac filled with synovial fluid that cushions adjacent bone structures and reduces friction in joint movement. This procedure is usually carried out to relieve chronic inflammation (bursitis) or infection, when conservative management has failed to improve patient outcomes. See also * List of surgeries by type Many surgical procedure names can be broken into parts to indicate the meaning. For example, in gastrectomy, "ectomy" is a suffix meaning the removal of a part of the body. "Gastro-" means stomach. Thus, ''gastrectomy'' refers to the surgical remo ... References Further reading * * * Orthopedic surgical procedures Synovial bursae {{Treatment-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
T Cells
A T cell is a type of lymphocyte. T cells are one of the important white blood cells of the immune system and play a central role in the adaptive immune response. T cells can be distinguished from other lymphocytes by the presence of a T-cell receptor (TCR) on their cell surface. T cells are born from hematopoietic stem cells, found in the bone marrow. Developing T cells then migrate to the thymus gland to develop (or mature). T cells derive their name from the thymus. After migration to the thymus, the precursor cells mature into several distinct types of T cells. T cell differentiation also continues after they have left the thymus. Groups of specific, differentiated T cell subtypes have a variety of important functions in controlling and shaping the immune response. One of these functions is immune-mediated cell death, and it is carried out by two major subtypes: CD8+ "killer" and CD4+ "helper" T cells. (These are named for the presence of the cell surface proteins CD8 or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transplant Rejection
Transplant rejection occurs when Organ transplant, transplanted tissue is rejected by the recipient's immune system, which destroys the transplanted tissue. Transplant rejection can be lessened by determining the molecular similitude between donor and recipient and by use of immunosuppressant drugs after transplant. Types of transplant rejection Transplant rejection can be classified into three types: hyperacute, acute, and chronic. These types are differentiated by how quickly the recipient's immune system is activated and the specific aspect or aspects of immunity involved. Hyperacute rejection Hyperacute rejection is a form of rejection that manifests itself in the minutes to hours following transplantation. It is caused by the presence of pre-existing Antibody, antibodies in the recipient that recognize antigens in the donor organ. These antigens are located on the endothelial lining of blood vessels within the transplanted organ and, once antibodies bind, will lead to the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Human Leukocyte Antigen
The human leukocyte antigen (HLA) system or complex is a complex of genes on chromosome 6 in humans which encode cell-surface proteins responsible for the regulation of the immune system. The HLA system is also known as the human version of the major histocompatibility complex (MHC) found in many animals. Mutations in HLA genes may be linked to autoimmune disease such as type I diabetes, and celiac disease. The HLA gene complex resides on a 3 Mbp stretch within chromosome 6, p-arm at 21.3. HLA genes are highly polymorphic, which means that they have many different alleles, allowing them to fine-tune the adaptive immune system. The proteins encoded by certain genes are also known as ''antigens'', as a result of their historic discovery as factors in organ transplants. HLAs corresponding to MHC class I ( A, B, and C), all of which are the HLA Class1 group, present peptides from inside the cell. For example, if the cell is infected by a virus, the HLA system brings fragme ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lymph Nodes
A lymph node, or lymph gland, is a kidney-shaped organ of the lymphatic system and the adaptive immune system. A large number of lymph nodes are linked throughout the body by the lymphatic vessels. They are major sites of lymphocytes that include B and T cells. Lymph nodes are important for the proper functioning of the immune system, acting as filters for foreign particles including cancer cells, but have no detoxification function. In the lymphatic system a lymph node is a secondary lymphoid organ. A lymph node is enclosed in a fibrous capsule and is made up of an outer cortex and an inner medulla. Lymph nodes become inflamed or enlarged in various diseases, which may range from trivial throat infections to life-threatening cancers. The condition of lymph nodes is very important in cancer staging, which decides the treatment to be used and determines the prognosis. Lymphadenopathy refers to glands that are enlarged or swollen. When inflamed or enlarged, lymph nodes can be fi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mitomycins
The mitomycins are a family of aziridine-containing natural products isolated from '' Streptomyces caespitosus'' or '' Streptomyces lavendulae.'' They include mitomycin A, mitomycin B, and mitomycin C. When the name mitomycin occurs alone, it usually refers to mitomycin C, its international nonproprietary name. Mitomycin C is used as a medicine for treating various disorders associated with the growth and spread of cells. Biosynthesis In general, the biosynthesis of all mitomycins proceeds via combination of 3-amino-5-hydroxybenzoic acid (AHBA), D-glucosamine, and carbamoyl phosphate, to form the mitosane core, followed by specific tailoring steps. The key intermediate, AHBA, is a common precursor to other anticancer drugs, such as rifamycin and ansamycin. Specifically, the biosynthesis begins with the addition of phosphoenolpyruvate (PEP) to erythrose-4-phosphate (E4P) with a yet undiscovered enzyme, which is then ammoniated to give 4-amino-3-deoxy-D-arabino heptulosonic aci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Immunology
Immunology is a branch of medicineImmunology for Medical Students, Roderick Nairn, Matthew Helbert, Mosby, 2007 and biology that covers the medical study of immune systems in humans, animals, plants and sapient species. In such we can see there is a difference of human immunology and comparative immunology in veterinary medicine and animal biosciences. Immunology measures, uses charts and differentiate in context in medicine the studies of immunity on cell and molecular level, and the immune system as part of the physiological level as its functioning is of major importance. In the different states of both health, occurring symptoms and diseases; the functioning of the immune system and immunological responses such as autoimmune diseases, allergic hypersensitivities, or in some cases malfunctioning of immune system as for example in immunological disorders or in immune deficiency, and the specific transplant rejection) Immunology has applications in numerous disciplines of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Immune System
The immune system is a network of biological processes that protects an organism from diseases. It detects and responds to a wide variety of pathogens, from viruses to parasitic worms, as well as cancer cells and objects such as wood splinters, distinguishing them from the organism's own healthy tissue. Many species have two major subsystems of the immune system. The innate immune system provides a preconfigured response to broad groups of situations and stimuli. The adaptive immune system provides a tailored response to each stimulus by learning to recognize molecules it has previously encountered. Both use molecules and cells to perform their functions. Nearly all organisms have some kind of immune system. Bacteria have a rudimentary immune system in the form of enzymes that protect against virus infections. Other basic immune mechanisms evolved in ancient plants and animals and remain in their modern descendants. These mechanisms include phagocytosis, antimicrobial pe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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