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Because T cells recognize only fragmented antigens displayed on cell surfaces, antigen processing must occur before the antigen fragment can be recognized by a T-cell receptor. Specifically, the fragment, bound to the major histocompatibility complex (MHC) , is transported to the surface of the antigen-presenting cell , a process known as ...
Antigen presentation stimulates immature T cells to become either mature "cytotoxic" CD8+ cells or mature "helper" CD4+ cells. An antigen-presenting cell (APC) or accessory cell is a cell that displays an antigen bound by major histocompatibility complex (MHC) proteins on its surface; this process is known as antigen presentation.
Thoracentesis / ˌ θ ɔː r ə s ɪ n ˈ t iː s ɪ s /, also known as thoracocentesis (from Greek θώραξ (thōrax, GEN thōrakos) 'chest, thorax' and κέντησις (kentēsis) 'pricking, puncture'), pleural tap, needle thoracostomy, or needle decompression (often used term), is an invasive medical procedure to remove fluid or air from the pleural space for diagnostic or therapeutic ...
Langerhans' cells are particular type of dendritic cells present in non lymphoid tissues together with interstitial cells. When these cells (in an immature state) come in contact with antigenic cells or disease causing viruses etc. these cells produce an inflammatory stimulus and start antigen processing and move toward lymph nodes where these ...
During this maturation process, there is nuclear extrusion – i.e. mature erythrocytes have no nucleus. Nucleated red blood cells present in a sample of bone marrow can indicate the release of incompletely developed cells. This can occur in pathology such as thalassaemia, severe anaemia or haematological malignancy.
MHC class I molecules are one of two primary classes of major histocompatibility complex (MHC) molecules (the other being MHC class II) and are found on the cell surface of all nucleated cells in the bodies of vertebrates. [1] [2] They also occur on platelets, but not on red blood cells.
At these conditions, nucleation of ice is either slow or does not occur at all. However, at lower temperatures nucleation is fast, and ice crystals appear after little or no delay. [1] [2] Nucleation is a common mechanism which generates first-order phase transitions, and it is the start of the process of forming a new thermodynamic phase. In ...
In cell biology, microtubule nucleation is the event that initiates de novo formation of microtubules (MTs). These filaments of the cytoskeleton typically form through polymerization of α- and β-tubulin dimers, the basic building blocks of the microtubule, which initially interact to nucleate a seed from which the filament elongates.