|
Cross Match
Cross-matching or crossmatching is a test performed before a blood transfusion as part of blood compatibility testing. Normally, this involves adding the recipient's blood plasma to a sample of the donor's red blood cells. If the blood is incompatible, the antibodies in the recipient's plasma will bind to antigens on the donor red blood cells. This antibody-antigen reaction can be detected through visible clumping or destruction of the red blood cells, or by reaction with anti-human globulin. Along with blood typing of the donor and recipient and screening for unexpected blood group antibodies, cross-matching is one of a series of steps in pre-transfusion testing. In some circumstances, an electronic cross-match can be performed by comparing records of the recipient's ABO and Rh blood type against that of the donor sample. In emergencies, blood may be issued before cross-matching is complete. Cross-matching is also used to determine compatibility between a donor and recipient ... [...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] |
Organ Transplantation
Organ transplantation is a medical procedure in which an organ (anatomy), organ is removed from one body and placed in the body of a recipient, to replace a damaged or missing organ. The donor and recipient may be at the same location, or organs may be transported from a Organ donation, donor site to another location. Organ (anatomy), Organs and/or Tissue (biology), tissues that are transplanted within the same person's body are called autografts. Transplants that are recently performed between two subjects of the same species are called allografts. Allografts can either be from a living or cadaveric source. Organs that have been successfully transplanted include the Heart transplantation, heart, Kidney transplantation, kidneys, Liver transplantation, liver, Lung transplantation, lungs, Pancreas transplantation, pancreas, Intestinal transplant, intestine, Thymus transplantation, thymus and uterus transplantation, uterus. Tissues include Bone grafting, bones, tendons (both referr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blood Compatibility Testing
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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microscope
A microscope () is a laboratory instrument used to examine objects that are too small to be seen by the naked eye. Microscopy is the science of investigating small objects and structures using a microscope. Microscopic means being invisible to the eye unless aided by a microscope. There are many types of microscopes, and they may be grouped in different ways. One way is to describe the method an instrument uses to interact with a sample and produce images, either by sending a beam of light or electrons through a sample in its optical path, by detecting photon emissions from a sample, or by scanning across and a short distance from the surface of a sample using a probe. The most common microscope (and the first to be invented) is the optical microscope, which uses lenses to refract visible light that passed through a thinly sectioned sample to produce an observable image. Other major types of microscopes are the fluorescence microscope, electron microscope (both the transmi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Haemolytic Disease Of The Newborn
Hemolytic disease of the newborn, also known as hemolytic disease of the fetus and newborn, HDN, HDFN, or erythroblastosis foetalis, is an alloimmune condition that develops in a fetus at or around birth, when the IgG molecules (one of the five main types of antibodies) produced by the mother pass through the placenta. Among these antibodies are some which attack antigens on the red blood cells in the fetal circulation, breaking down and destroying the cells. The fetus can develop reticulocytosis and anemia. The intensity of this fetal disease ranges from mild to very severe, and fetal death from heart failure (hydrops fetalis) can occur. When the disease is moderate or severe, many erythroblasts (immature red blood cells) are present in the fetal blood, earning these forms of the disease the name ''erythroblastosis fetalis'' (). HDFN represents a breach of immune privilege for the fetus or some other form of impairment of the immune tolerance in pregnancy. Various types of HD ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transfusion Reaction
Blood transfusion is the process of transferring blood products into a person's Circulatory system, 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, blood plasma, plasma, clotting factors and platelets. Red blood cells (RBC) contain hemoglobin, and supply the Cell (biology), 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 scien ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Red Blood Cell
Red blood cells (RBCs), also referred to as red cells, red blood corpuscles (in humans or other animals not having nucleus in red blood cells), haematids, erythroid cells or erythrocytes (from Greek ''erythros'' for "red" and ''kytos'' for "hollow vessel", with ''-cyte'' translated as "cell" in modern usage), are the most common type of blood cell and the vertebrate's principal means of delivering oxygen (O2) to the body tissues—via blood flow through the circulatory system. RBCs take up oxygen in the lungs, or in fish the gills, and release it into tissues while squeezing through the body's capillaries. The cytoplasm of a red blood cell is rich in hemoglobin, an iron-containing biomolecule that can bind oxygen and is responsible for the red color of the cells and the blood. Each human red blood cell contains approximately 270 million hemoglobin molecules. The cell membrane is composed of proteins and lipids, and this structure provides properties essential for physiolo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhesus Blood Group System
The Rh blood group system is a human blood group system. It contains proteins on the surface of red blood cells. After the ABO blood group system, it is the most likely to be involved in transfusion reactions. The Rh blood group system consists of 49 defined blood group antigens, among which the five antigens D, C, c, E, and e are the most important. There is no d antigen. Rh(D) status of an individual is normally described with a ''positive'' (+) or ''negative'' (−) suffix after the ABO type (e.g., someone who is A+ has the A antigen and Rh(D) antigen, whereas someone who is A− has the A antigen but lacks the Rh(D) antigen). The terms ''Rh factor'', ''Rh positive'', and ''Rh negative'' refer to the Rh(D) antigen only. Antibodies to Rh antigens can be involved in hemolytic transfusion reactions and antibodies to the Rh(D) and Rh antigens confer significant risk of hemolytic disease of the fetus and newborn. Nomenclature The Rh blood group system has two sets of nomenclature ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blood Donation
A blood donation occurs when a person voluntarily has blood drawn and used for blood transfusion, transfusions and/or made into biopharmaceutical medications by a process called Blood fractionation, fractionation (separation of whole blood components). Donation may be of whole blood, or of specific components directly (apheresis). Blood banks often participate in the collection process as well as the procedures that follow it. Today in the developed world, most blood donors are unpaid volunteers who donate blood for a community supply. In some countries, established supplies are limited and donors usually give blood when family or friends need a transfusion (directed donation). Many donors donate for several reasons, such as a form of charity, general awareness regarding the demand for blood, increased confidence in oneself, helping a personal friend or relative, and social pressure. Despite the many reasons that people donate, not enough potential donors actively donate. Ho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coomb's Test
A Coombs test, also known as antiglobulin test (AGT), is either of two blood tests used in immunohematology. They are the direct and indirect Coombs tests. The direct Coombs test detects antibodies that are stuck to the surface of the red blood cells. Since these antibodies sometimes destroy red blood cells, a person can be anemic and this test can help clarify the condition. The indirect Coombs detects antibodies that are floating freely in the blood. These antibodies could act against certain red blood cells and the test can be done to diagnose reactions to a blood transfusion. The direct Coombs test is used to test for autoimmune hemolytic anemia—that is, a condition where the immune system breaks down red blood cells, leading to anemia. The direct Coombs test is used to detect antibodies or complement proteins attached to the surface of red blood cells. To perform the test, a blood sample is taken and the red blood cells are washed (removing the patient's own plasma and u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Centrifuge
A centrifuge is a device that uses centrifugal force to separate various components of a fluid. This is achieved by spinning the fluid at high speed within a container, thereby separating fluids of different densities (e.g. cream from milk) or liquids from solids. It works by causing denser substances and particles to move outward in the radial direction. At the same time, objects that are less dense are displaced and moved to the centre. In a laboratory centrifuge that uses sample tubes, the radial acceleration causes denser particles to settle to the bottom of the tube, while low-density substances rise to the top. A centrifuge can be a very effective filter that separates contaminants from the main body of fluid. Industrial scale centrifuges are commonly used in manufacturing and waste processing to sediment suspended solids, or to separate immiscible liquids. An example is the cream separator found in dairies. Very high speed centrifuges and ultracentrifuges able to provi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sensitivity And Specificity
''Sensitivity'' and ''specificity'' mathematically describe the accuracy of a test which reports the presence or absence of a condition. Individuals for which the condition is satisfied are considered "positive" and those for which it is not are considered "negative". *Sensitivity (true positive rate) refers to the probability of a positive test, conditioned on truly being positive. *Specificity (true negative rate) refers to the probability of a negative test, conditioned on truly being negative. If the true condition can not be known, a " gold standard test" is assumed to be correct. In a diagnostic test, sensitivity is a measure of how well a test can identify true positives and specificity is a measure of how well a test can identify true negatives. For all testing, both diagnostic and screening, there is usually a trade-off between sensitivity and specificity, such that higher sensitivities will mean lower specificities and vice versa. If the goal is to return the ratio at w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
