diff --git a/modules/m45543/index.cnxml b/modules/m45543/index.cnxml index daa39db11..5c5e0a901 100644 --- a/modules/m45543/index.cnxml +++ b/modules/m45543/index.cnxml @@ -39,7 +39,7 @@ Antibodies may inhibit infection by (a) preventing the antigen from binding its target, (b) tagging a pathogen for destruction by macrophages or neutrophils, or (c) activating the complement cascade. -The availability and reliability of antibodies makes them ideally suited for use in medical tests and investigations. Radioimmunossays, for example, rely on the antigen-antibody interaction. Usually, a specific antigen is made radioactive, allowed to bind to its antibody, and then introduced into a sample substance, such as a patient's blood. By measuring eventual changes in the quantity of the bound and unbound antigen, analysts can detect the presence and/or concentration of certain substances. Developed by Rosalyn Sussman Yalow and Solomon Berson in the 1950s, the technique is known for extreme sensitivity, meaning that it can detect and measure very small quantities of a substance. It is used in narcotics detection, blood bank screening, early cancer screening, hormone measurement, and allergy diagnosis. Based on her significant contribution to the field, Yalow received a Nobel Prize, making her the second woman to be awarded the prize for medicine. +The availability and reliability of antibodies makes them ideally suited for use in medical tests and investigations. Radioimmunoassays, for example, rely on the antigen-antibody interaction. Usually, a specific antigen is made radioactive, allowed to bind to its antibody, and then introduced into a sample substance, such as a patient's blood. By measuring eventual changes in the quantity of the bound and unbound antigen, analysts can detect the presence and/or concentration of certain substances. Developed by Rosalyn Sussman Yalow and Solomon Berson in the 1950s, the technique is known for extreme sensitivity, meaning that it can detect and measure very small quantities of a substance. It is used in narcotics detection, blood bank screening, early cancer screening, hormone measurement, and allergy diagnosis. Based on her significant contribution to the field, Yalow received a Nobel Prize, making her the second woman to be awarded the prize for medicine.
Cell-Mediated Immunity Unlike B cells, T lymphocytes are unable to recognize pathogens without assistance. Instead, dendritic cells and macrophages first engulf and digest pathogens into hundreds or thousands of antigens. Then, an antigen-presenting cell (APC) detects, engulfs, and informs the adaptive immune response about an infection. When a pathogen is detected, these APCs will engulf and break it down through phagocytosis. Antigen fragments will then be transported to the surface of the APC, where they will serve as an indicator to other immune cells. A dendritic cell is an immune cell that mops up antigenic materials in its surroundings and presents them on its surface. Dendritic cells are located in the skin, the linings of the nose, lungs, stomach, and intestines. These positions are ideal locations to encounter invading pathogens. Once they are activated by pathogens and mature to become APCs they migrate to the spleen or a lymph node. Macrophages also function as APCs. After phagocytosis by a macrophage, the phagocytic vesicle fuses with an intracellular lysosome. Within the resulting phagolysosome, the components are broken down into fragments; the fragments are then loaded onto MHC class II molecules and are transported to the cell surface for antigen presentation (). Helper T cells cannot properly respond to an antigen unless it is processed and embedded in an MHC class II molecule. The APCs express MHC class II on their surfaces, and when combined with a foreign antigen, these complexes signal an invader. diff --git a/modules/m66665/index.cnxml b/modules/m66665/index.cnxml index 73645de58..51456493a 100644 --- a/modules/m66665/index.cnxml +++ b/modules/m66665/index.cnxml @@ -54,7 +54,7 @@
Antibodies of the Mucosal Immune System Antibodies synthesized by the mucosal immune system include IgA and IgM. Activated B cells differentiate into mucosal plasma cells that synthesize and secrete dimeric IgA, and to a lesser extent, pentameric IgM. Secreted IgA is abundant in tears, saliva, breast milk, and in secretions of the gastrointestinal and respiratory tracts. Antibody secretion results in a local humoral response at epithelial surfaces and prevents infection of the mucosa by binding and neutralizing pathogens.
Antibodies in Detection and Measurement -The variety, specificity, and reliability of antibodies makes them ideally suited for certain medical tests and investigations. Radioimmunossays (RIA), for example, rely on the antigen-antibody interaction to detect the presence and/or concentration of certain antigens. Developed by Rosalyn Sussman Yalow and Solomon Berson in the 1950s, the technique is known for extreme sensitivity, meaning that it can detect and measure very small quantities of a substance. It is used in narcotics detection, blood bank screening, early cancer screening, hormone measurement, and allergy diagnosis. Based on her significant contribution to medicine, Yalow received a Nobel Prize, making her the second woman to be awarded the prize for medicine. +The variety, specificity, and reliability of antibodies makes them ideally suited for certain medical tests and investigations. Radioimmunoassays (RIA), for example, rely on the antigen-antibody interaction to detect the presence and/or concentration of certain antigens. Developed by Rosalyn Sussman Yalow and Solomon Berson in the 1950s, the technique is known for extreme sensitivity, meaning that it can detect and measure very small quantities of a substance. It is used in narcotics detection, blood bank screening, early cancer screening, hormone measurement, and allergy diagnosis. Based on her significant contribution to medicine, Yalow received a Nobel Prize, making her the second woman to be awarded the prize for medicine. The basic principle of radioimmunoassay is competitive binding, where a radioactive antigen competes with a non-radioactive antigen for a fixed number of antibody or receptor binding sites. First, an antigen is made radioactive (tagged), and then it is mixed with a known quantity of its specific antibody. When a sample. such as one from the patient's blood, is introduced, antibodies will cease binding to the tagged antigen and instead bind to the untagged one, a process called displacement. After several steps, the amount of newly unbound tagged antigen is measured to see how much displacement occurred, which indicates the presence and concentration of the antigen in the blood.For example, to measure insulin levels, the first step is to mix known amounts of radioisotope-tagged insulin and antibodies. These combine chemically. Next, a small amount of the patient's blood is added. The insulin contained in the blood displaces some of the tagged insulin. The tagged insulin is then measured with isotope detectors, and the patient's insulin level is calculated.