|
Agglutinins
Agglutination is the clumping of particles. The word ''agglutination'' comes from the Latin '' agglutinare'' (glueing to). Agglutination is the process that occurs if an antigen is mixed with its corresponding antibody called isoagglutinin. This term is commonly used in blood grouping. This occurs in biology in two main examples: # The clumping of cells such as bacteria or red blood cells in the presence of an antibody or complement. The antibody or other molecule binds multiple particles and joins them, creating a large complex. This increases the efficacy of microbial elimination by phagocytosis as large clumps of bacteria can be eliminated in one pass, versus the elimination of single microbial antigens. # When people are given blood transfusions of the wrong blood group, the antibodies react with the incorrectly transfused blood group and as a result, the erythrocytes clump up and stick together causing them to agglutinate. The coalescing of small particles that are suspend ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hemagglutinin
In molecular biology, hemagglutinins (or ''haemagglutinin'' in British English) (from the Greek , 'blood' + Latin , 'glue') are receptor-binding membrane fusion glycoproteins produced by viruses in the ''Paramyxoviridae'' family. Hemagglutinins are responsible for binding to receptors on red blood cells to initiate viral attachment and infection. The agglutination of red cells occurs when antibodies on one cell bind to those on others, causing amorphous aggregates of clumped cells.Hemagglutinins recognize cell-surface glycoconjugates containing sialic acid on the surface of host red blood cells with a low affinity, and use them to enter the endosome of host cells. In the endosome, hemagglutinins are activated at a pH of 5 - 6.5, to undergo conformational changes that enable viral attachment through a fusion peptide. Agglutination and hemagglutinins were discovered by virologist George K. Hirst in 1941. Alfred Gottschalk proved in 1957 that hemagglutinins bind a virus to a host c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cold Agglutinin Disease
Cold agglutinin disease (CAD) is a rare autoimmune disease characterized by the presence of high concentrations of circulating cold sensitive antibodies, usually IgM and autoantibodies that are also active at temperatures below , directed against red blood cells, causing them to agglutinate and undergo lysis. It is a form of autoimmune hemolytic anemia, specifically one in which antibodies bind red blood cells only at low body temperatures, typically 28–31 °C. When affected people's blood is exposed to cold temperatures ( to ), certain proteins that normally attack bacteria (IgM antibodies) attach themselves to red blood cells and bind them together into clumps (agglutination). This eventually causes red blood cells to be prematurely destroyed (hemolysis) leading to anemia and other associated signs and symptoms. Cold agglutinin disease can be primary (unknown cause) or secondary, due to an underlying condition such as an infection, another autoimmune disease, or cert ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blood Type
A blood type (also known as a blood group) is a classification of blood, based on the presence and absence of antibodies and inherited antigenic substances on the surface of red blood cells (RBCs). These antigens may be proteins, carbohydrates, glycoproteins, or glycolipids, depending on the blood group system. Some of these antigens are also present on the surface of other types of cells of various tissues. Several of these red blood cell surface antigens can stem from one allele (or an alternative version of a gene) and collectively form a blood group system. Blood types are inherited and represent contributions from both parents of an individual. , a total of 43 human blood group systems are recognized by the International Society of Blood Transfusion (ISBT). The two most important blood group systems are ABO and Rh; they determine someone's blood type (A, B, AB, and O, with + or − denoting RhD status) for suitability in blood transfusion. Blood group systems A com ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Autoagglutination
In hematology, red cell agglutination or autoagglutination is a phenomenon in which red blood cells clump together, forming aggregates. It is caused by the surface of the red cells being coated with antibodies. This often occurs in cold agglutinin disease, a type of autoimmune hemolytic anemia in which people produce antibodies (termed cold agglutinins) that bind to their red blood cells at cold temperatures and destroy them. People may develop cold agglutinins from lymphoproliferative disorders, from infection with ''Mycoplasma pneumoniae'' or Epstein–Barr virus, or idiopathically (without any apparent cause). Red cell agglutination can also occur in paroxysmal nocturnal hemoglobinuria and warm autoimmune hemolytic anemia. In cases of red cell agglutination, the direct antiglobulin test can be used to demonstrate the presence of antibodies bound to the red cells. __TOC__ Interference with laboratory tests Red blood cell aggregates are counted as single cells by the automated ana ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Complete Blood Count
A complete blood count (CBC), also known as a full blood count (FBC), is a set of medical laboratory tests that provide cytometry, information about the cells in a person's blood. The CBC indicates the counts of white blood cells, red blood cells and platelets, the concentration of hemoglobin, and the hematocrit (the volume percentage of red blood cells). The red blood cell indices, which indicate the average size and hemoglobin content of red blood cells, are also reported, and a white blood cell differential, which counts the different types of white blood cells, may be included. The CBC is often carried out as part of a medical assessment and can be used to monitor health or diagnose diseases. The results are interpreted by comparing them to Reference ranges for blood tests, reference ranges, which vary with sex and age. Conditions like anemia and thrombocytopenia are defined by abnormal complete blood count results. The red blood cell indices can provide information about the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blood Transfusion
Blood transfusion is the process of transferring blood products into a person's circulation intravenously. Transfusions are used for various medical conditions to replace lost components of the blood. Early transfusions used whole blood, but modern medical practice commonly uses only components of the blood, such as red blood cells, white blood cells, plasma, clotting factors and platelets. Red blood cells (RBC) contain hemoglobin, and supply the cells of the body with oxygen. White blood cells are not commonly used during transfusion, but they are part of the immune system, and also fight infections. Plasma is the "yellowish" liquid part of blood, which acts as a buffer, and contains proteins and important substances needed for the body's overall health. Platelets are involved in blood clotting, preventing the body from bleeding. Before these components were known, doctors believed that blood was homogeneous. Because of this scientific misunderstanding, many patients died b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phytohaemagglutinin
Phytohaemagglutinin (PHA, or phytohemagglutinin) is a lectin found in plants, especially certain legumes. PHA actually consists of two closely related proteins, called leucoagglutinin (PHA-L) and PHA-E. These proteins cause blood cells to clump together. PHA-E cause erythrocytes (red blood cells) to clump. PHA-L causes leukocytes (white blood cells) to clump. Phytohaemagglutinin has carbohydrate-binding specificity for a complex oligosaccharide containing galactose, ''N''-acetylglucosamine, and mannose. It is found in the highest concentrations in uncooked red kidney beans and white kidney beans (also known as cannellini), and it is also found in lower quantities in many other types of green beans and other common beans ('' Phaseolus vulgaris''), as well as broad beans (''Vicia faba'') such as fava beans. It has a number of physiological effects and is used in medical research. In high doses, it is a toxin. The lectin has a number of effects on cell metabolism; it induces mito ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blood Typing
Blood compatibility testing is conducted in a medical laboratory to identify potential incompatibilities between blood group systems in blood transfusion. It is also used to diagnose and prevent some complications of pregnancy that can occur when the baby has a different blood group from the mother. Blood compatibility testing includes blood typing, which detects the antigens on red blood cells that determine a person's blood type; testing for unexpected antibodies against blood group antigens (antibody screening and identification); and, in the case of blood transfusions, mixing the recipient's plasma with the donor's red blood cells to detect incompatibilities ( crossmatching). Routine blood typing involves determining the ABO and RhD (Rh factor) type, and involves both identification of ABO antigens on red blood cells (forward grouping) and identification of ABO antibodies in the plasma (reverse grouping). Other blood group antigens may be tested for in specific clinical situ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
White Blood Cell
White blood cells, also called leukocytes or leucocytes, are the cell (biology), cells of the immune system that are involved in protecting the body against both infectious disease and foreign invaders. All white blood cells are produced and derived from multipotent cells in the bone marrow known as hematopoietic stem cells. Leukocytes are found throughout the body, including the blood and lymphatic system. All white blood cells have cell nucleus, nuclei, which distinguishes them from the other blood cells, the anucleated red blood cells (RBCs) and platelets. The different white blood cells are usually classified by cell division, cell lineage (myelocyte, myeloid cells or lymphocyte, lymphoid cells). White blood cells are part of the body's immune system. They help the body fight infection and other diseases. Types of white blood cells are granulocytes (neutrophils, eosinophils, and basophils), and agranulocytes (monocytes, and lymphocytes (T cells and B cells)). Myeloid cells ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Max Von Gruber
Max von Gruber (6 July 1853, in Vienna – 16 September 1927, in Berchtesgaden) was an Austrian scientist and eugenicist. As a bacteriologist he discovered specific agglutination in 1896 with his English colleague Herbert Durham (Gruber-Widal-reaction). But his main interests were studying hygiene and sexual life. Max von Gruber was the son of Ignaz Gruber (1803–1872), a general practitioner and the first specialist in otology in Austria, and publisher of a two-volume textbook on medical chemistry (1835). His brother was Franz von Gruber. He graduated from the Schottengymnasium in Vienna and studied medicine at the University of Vienna, receiving his medical doctorate in 1876. He then learned chemistry and physiology under Max von Pettenkofer (1818–1901) and Karl von Voit (1831–1908) in Munich and Karl Ludwig (1816–1895) in Leipzig. Also working under Pettenkofer was Hans Ernst August Buchner (1850–1902), who encouraged Gruber to concentrate on bacteriology. Unlike some ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Agglutination In The Blood
In linguistics, agglutination is a morphological process in which words are formed by stringing together morphemes, each of which corresponds to a single syntactic feature. Languages that use agglutination widely are called agglutinative languages. Turkish is an example of an agglutinative language. The Turkish word ("from your houses") consists of the morphemes ''ev-ler-iniz-den,'' literally translated morpheme-by-morpheme as ''house-plural-your(plural)-from''. Agglutinative languages are often contrasted with isolating languages, in which words are monomorphemic, and fusional languages, in which words can be complex, but morphemes may correspond to multiple features. Examples of agglutinative languages Although agglutination is characteristic of certain language families, this does not mean that when several languages in a certain geographic area are all agglutinative they are necessarily related phylogenetically. In the past, this assumption led linguists to propose the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Widal Test
The Widal test, developed in 1896 and named after its inventor, Georges-Fernand Widal, is an indirect agglutination test for enteric fever or undulant fever whereby bacteria causing typhoid fever is mixed with a serum containing specific antibodies obtained from an infected individual. In cases of ''Salmonella'' infection, it is a demonstration of the presence of O-soma false-positive result. Test results need to be interpreted carefully to account for any history of enteric fever, typhoid vaccination, and the general level of antibodies in the populations in endemic areas of the world. As with all serological tests, the rise in antibody levels needed to perform the diagnosis takes 7–14 days, which limits its applicability in early diagnosis. Other means of diagnosing ''Salmonella typhi'' (and '' paratyphi'') include cultures of blood, urine and faeces. These organisms produce H2S from thiosulfate and can be identified easily on differential media such as bismuth sulfite agar. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
