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RhD
Rh blood group, D antigen also known as Rh polypeptide 1 (RhPI) or cluster of differentiation 240D (CD240D) is a protein that in humans is encoded by the ''RHD'' gene. The RHD gene codes for the RhD erythrocyte membrane protein that is the Rh factor antigen of the Rh blood group system. RHD has sequence similarity to RHCE, RhAG, RhBG, and RhCG and these five genes constitute the Rh family. It was proposed that the erythrocyte Rh complex is a heterotrimer of RhAG, RhD, and RhCE protein subunits. RhAG is a functional ammonia transporter and is required for normal cell surface expression of RhD and RhCE. Patients who lack RhD/RhCE/RhAG on the surface of their erythrocytes have hemolytic anemia. Antibodies to the RhD protein can cause Rh disease. Model organisms Model organisms have been used in the study of RHD function. A conditional knockout mouse line, called ''Rhdtm1a(EUCOMM)Wtsi'' was generated as part of the International Knockout Mouse Consortium program — a high-throug ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rh 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 nomenclatu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rh Disease
Rh disease (also known as rhesus isoimmunization, Rh (D) disease, and blue baby disease) is a type of hemolytic disease of the fetus and newborn (HDFN). HDFN due to anti-D antibodies is the proper and currently used name for this disease as the Rh blood group system actually has more than 50 antigens and not only the D-antigen. The term "Rh Disease" is commonly used to refer to HDFN due to anti-D antibodies, and prior to the discovery of anti-Rho(D) immune globulin, it was the most common type of HDFN. The disease ranges from mild to severe, and occurs in the second or subsequent pregnancies of Rh-D negative women when the biologic father is Rh-D positive. Due to several advances in modern medicine, HDFN due to anti-D is preventable by treating the mother during pregnancy and soon after delivery with an injection of anti-Rho(D) (RhoGam) immune globulin. With successful mitigation of this disease by prevention through the use of anti-Rho(D) immune globulin, other antibodies a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antibody
An antibody (Ab), also known as an immunoglobulin (Ig), is a large, Y-shaped protein used by the immune system to identify and neutralize foreign objects such as pathogenic bacteria and Viral disease, viruses. The antibody recognizes a unique molecule of the pathogen, called an antigen. Each tip of the "Y" of an antibody contains a paratope (analogous to a lock) that is specific for one particular epitope (analogous to a key) on an antigen, allowing these two structures to bind together with precision. Using this binding mechanism, an antibody can ''tag'' a microbe or an infected cell for attack by other parts of the immune system, or can neutralize it directly (for example, by blocking a part of a virus that is essential for its invasion). To allow the immune system to recognize millions of different antigens, the antigen-binding sites at both tips of the antibody come in an equally wide variety. In contrast, the remainder of the antibody is relatively constant. It only occurs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RHCE (gene)
Blood group Rh(CE) polypeptide is a protein that in humans is encoded by the ''RHCE'' gene. RHCE has also recently been designated CD240CE ( cluster of differentiation 240CE). The Rh blood group system is the second most clinically significant of the blood groups, second only to ABO. It is also the most polymorphic of the blood groups, with variations due to deletions, gene conversions, and missense mutations. The Rh blood group includes this gene which encodes both the RhC and RhE antigens on a single polypeptide and a second gene which encodes the RhD protein. The classification of Rh-positive and Rh-negative individuals is determined by the presence or absence of the highly immunogenic RhD protein on the surface of erythrocytes. Alternative splicing of this gene results in four transcript variants encoding four different isoforms. A recent study in the population of the island of Sardinia shows the association of a noncoding variant in the RHCE gene (rs630337) with an increa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ammonia Transporter
Ammonia transportersTC# 1.A.11 are structurally related membrane transport proteins called Amt proteins (ammonia transporters) in bacteria and plants, methylammonium/ammonium permeases (MEPs) in yeast, or Rhesus (Rh) proteins in chordates. In humans, the RhAG, RhBG, and RhCG Rhesus proteins constitute solute carrier family 42 whilst RhD and RhCE form the Rh blood group system. The three-dimensional structure of the ammonia transport protein AmtB from ''Escherichia coli'' has been determined by x-ray crystallography; ; revealing a hydrophobic ammonia channel. The human RhCG ammonia transporter was found to have a similar ammonia-conducting channel structure. It was proposed that the erythrocyte Rh complex is a heterotrimer of RhAG, RhD, and RhCE subunits in which RhD and RhCE might play roles in anchoring the ammonia-conducting RhAG subunit to the cytoskeleton. Based on reconstitution experiments, purified RhCG subunits alone can function to transport ammonia. RhCG is required ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Erythrocyte
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 physio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RHAG
Rh-associated glycoprotein (RHAG) is an ammonia transporter protein that in humans is encoded by the ''RHAG'' gene. RHAG has also recently been designated CD241 (cluster of differentiation 241). Mutations in the RHAG gene can cause stomatocytosis. Function The Rh blood group antigens (MIM 111700) are associated with human erythrocyte membrane proteins of approximately 30 kD, the so-called Rh30 polypeptides. Heterogeneously glycosylated membrane proteins of 50 and 45 kD, the Rh50 glycoproteins, are coprecipitated with the Rh30 polypeptides on immunoprecipitation with anti-Rh-specific mono- and polyclonal antibodies. The Rh antigens appear to exist as a multisubunit complex of CD47 (MIM 601028), LW (MIM 111250), glycophorin B (MIM 111740), and play a critical role in the Rh50 glycoprotein upplied by OMIM Interactions RHAG has been shown to interact with ANK1. See also * Rh deficiency syndrome References Further reading * * * * * * * * * * * * * * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, responding to stimuli, providing structure to cells and organisms, and transporting molecules from one location to another. Proteins differ from one another primarily in their sequence of amino acids, which is dictated by the nucleotide sequence of their genes, and which usually results in protein folding into a specific 3D structure that determines its activity. A linear chain of amino acid residues is called a polypeptide. A protein contains at least one long polypeptide. Short polypeptides, containing less than 20–30 residues, are rarely considered to be proteins and are commonly called peptides. The individual amino acid residues are bonded together by peptide bonds and adjacent amino acid residues. The sequence of amino acid resid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dual-energy X-ray Absorptiometry
Dual-energy X-ray absorptiometry (DXA, or DEXA) is a means of measuring bone mineral density (BMD) using spectral imaging. Two X-ray beams, with different energy levels, are aimed at the patient's bones. When soft tissue absorption is subtracted out, the bone mineral density (BMD) can be determined from the absorption of each beam by bone. Dual-energy X-ray absorptiometry is the most widely used and most thoroughly studied bone density measurement technology. The DXA scan is typically used to diagnose and follow osteoporosis, as contrasted to the nuclear bone scan, which is sensitive to certain metabolic diseases of bones in which bones are attempting to heal from infections, fractures, or tumors. It is also sometimes used to assess body composition. Physics Soft tissue and bone have different attenuation coefficients to X-rays. A single X-ray beam passing through the body will be attenuated by both soft tissue and bone, and it is not possible to determine, from a single ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radiography
Radiography is an imaging technique using X-rays, gamma rays, or similar ionizing radiation and non-ionizing radiation to view the internal form of an object. Applications of radiography include medical radiography ("diagnostic" and "therapeutic") and industrial radiography. Similar techniques are used in airport security (where "body scanners" generally use backscatter X-ray). To create an image in conventional radiography, a beam of X-rays is produced by an X-ray generator and is projected toward the object. A certain amount of the X-rays or other radiation is absorbed by the object, dependent on the object's density and structural composition. The X-rays that pass through the object are captured behind the object by a detector (either photographic film or a digital detector). The generation of flat two dimensional images by this technique is called projectional radiography. In computed tomography (CT scanning) an X-ray source and its associated detectors rotate around ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clinical Chemistry
Clinical chemistry (also known as chemical pathology, clinical biochemistry or medical biochemistry) is the area of chemistry that is generally concerned with analysis of bodily fluids for diagnostic and therapeutic purposes. It is an applied form of biochemistry (not to be confused with medicinal chemistry, which involves basic research for drug development). The discipline originated in the late 19th century with the use of simple chemical reaction tests for various components of blood and urine. In the many decades since, other techniques have been applied as science and technology have advanced, including the use and measurement of enzyme activities, spectrophotometry, electrophoresis, and immunoassay. There are now many blood tests and clinical urine tests with extensive diagnostic capabilities. Most current laboratories are now highly automated to accommodate the high workload typical of a hospital laboratory. Tests performed are closely monitored and quality c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Micronucleus Test
A micronucleus test is a test used in toxicological screening for potential genotoxic compounds. The assay is now recognized as one of the most successful and reliable assays for genotoxic carcinogens, i.e., carcinogens that act by causing genetic damage and is recommended by the OECD guideline for the testing of chemicals. There are two major versions of this test, one '' in vivo'' and the other ''in vitro''. The ''in vivo'' test normally uses mouse bone marrow or mouse peripheral blood. When a bone marrow erythroblast develops into a polychromatic erythrocyte, the main nucleus is extruded; any micronucleus that has been formed may remain behind in the otherwise anucleated cytoplasm. Visualisation of micronuclei is facilitated in these cells because they lack a main nucleus. An increase in the frequency of micronucleated polychromatic erythrocytes in treated animals is an indication of induced chromosome damage. Micronuclei were first used to quantify chromosomal damage ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
