Graft versus Host Disease. Important. It is possible that the main title of the report Graft versus Host Disease is not the name you expected. Please check the synonyms listing to find the alternate name(s) and disorder subdivision(s) covered by this report. Synonyms. Disorder Subdivisions. General Discussion. Graft versus Host Disease (GVHD) is a rare disorder that can strike persons whose immune system is deficient or suppressed and who have received a bone marrow transplant or a nonirradiated blood transfusion. Symptoms may include skin rash, intestinal problems and liver dysfunction. Resources. Caitlin Raymond International Registry. UMASS Memorial Medical Center. Lake Avenue. Worcester, MA 0. Pustular psoriasis appears as raised bumps filled with noninfectious pus. The skin under and surrounding the pustules is red and tender. Inverse psoriasis. Helicobacter pylori is the leading cause of chronic gastritis, peptic ulcer disease, gastric adenocarcinoma and. Menopause is the time in a woman’s life when hormone production levels drop to a point where she stops getting her period (menstruating). Some treatments for breast. Please check the synonyms listing to. The following is a glossary of terms related to bone marrow failure diseases. You can also browse the glossary of drug names. INTRODUCTION. Graft-versus-host disease (GVHD) is the result of an intricate immune response following allogeneic stimuli. GVHD, which can be acute and/or chronic. Tel: (5. 08)3. 34- 8. Fax: (5. 08)3. 34- 8. Tel: (8. 00)7. 26- 2. Email: info@CRIR. Internet: http: //www. NIH/National Heart, Lung and Blood Institute. P. O. Box 3. 01. 05. Bethesda, MD 2. 08. Tel: (3. 01)5. 92- 8. Fax: (3. 01)2. 51- 1. Email: nhlbiinfo@rover. Internet: http: //www. Genetic and Rare Diseases (GARD) Information Center. PO Box 8. 12. 6Gaithersburg, MD 2. Tel: (3. 01)2. 51- 4. Fax: (3. 01)2. 51- 4. Tel: (8. 88)2. 05- 2. TDD: (8. 88)2. 05- 3. Internet: http: //rarediseases. GARD/Locks of Love. Southern Blvd. West Palm Beach, FL 3. Tel: (5. 61)8. 33- 7. Fax: (5. 61)8. 33- 7. Tel: (8. 88)8. 96- 1. TDD: (5. 61)8. 33- 7. Email: info@locksoflove. Internet: http: //www. Autoimmune Information Network, Inc. PO Box 4. 12. 1Brick, NJ 0. Fax: (7. 32)5. 43- 7. Email: autoimmunehelp@aol. European Society for Immunodeficiencies. Chantepoulet. Geneva, CH 1. Switzerland. Tel: 4. Fax: 4. 12. 29. 06. Email: esid@kenes. Internet: http: //www. For a Complete Report. This is an abstract of a report from the National Organization for Rare Disorders (NORD). A copy of the complete report can be downloaded free from the NORD website for registered users. The complete report contains additional information including symptoms, causes, affected population, related disorders, standard and investigational therapies (if available), and references from medical literature. For a full- text version of this topic, go to www. Rare Disease Database under . It is provided for informational purposes only. NORD recommends that affected individuals seek the advice or counsel of their own personal physicians. It is possible that the title of this topic is not the name you selected. Please check the Synonyms listing to find the alternate name(s) and Disorder Subdivision(s) covered by this report. This disease entry is based upon medical information available through the date at the end of the topic. Since NORD's resources are limited, it is not possible to keep every entry in the Rare Disease Database completely current and accurate. Please check with the agencies listed in the Resources section for the most current information about this disorder. For additional information and assistance about rare disorders, please contact the National Organization for Rare Disorders at P. O. Box 1. 96. 8, Danbury, CT 0. Last Updated: 1/1. Copyright 1. 99. 1, 1. National Organization for Rare Disorders, Inc. Liver - Wikipedia. The liver is a vital organ only found in vertebrates. The liver has a wide range of functions, including detoxification of various metabolites, protein synthesis, and the production of biochemicals necessary for digestion. It is an accessory digestive gland and produces bile, an alkaline compound which aids in digestion via the emulsification of lipids. The gallbladder, a small pouch that sits just under the liver, stores bile produced by the liver. Artificial livers are yet to be developed to promote long term replacement in the absence of the liver. A human liver normally weighs 1. Located in the right upper quadrant of the abdominal cavity, it rests just below the diaphragm, to the right of the stomach and overlies the gallbladder. The hepatic artery carries oxygen- rich blood from the aorta, whereas the portal vein carries blood rich in digested nutrients from the entire gastrointestinal tract and also from the spleen and pancreas. Each lobule is made up of millions of hepatic cells (hepatocytes) which are the basic metabolic cells. The lobules are held together by a fine dense irregular fibroelastic connective tissue layer which extends into the structure of the liver, by accompanying the vessels (veins and arteries), ducts and nerves through the hepatic portal, as a fibrous capsule called Glisson's capsule. The fibrous coat is of areolar tissue and follows the vessels and ducts to support them. From the visceral surface, the two additional lobes are located between the right and left lobes, one in front of the other. A line can be imagined running from the left of the vena cava and all the way forward to divide the liver and gallbladder into two halves. An important anatomical landmark, the porta hepatis, also known as the transverse fissure of the liver, divides this left portion into four segments, which can be numbered starting at the caudate lobe as I in an anticlockwise manner. From this visceral view, seven segments can be seen, because the eighth segment is only visible in the parietal view. The peritoneum folds back on itself to form the falciform ligament and the right and left triangular ligaments. It is covered in peritoneum apart from where it attaches the gallbladder and the porta hepatis. Underneath the right lobe and to the right of the gallbladder fossa, are two impressions, one behind the other and separated by a ridge. The one in front is a shallow colic impression, formed by the hepatic flexure and the one behind is a deeper renal impression accommodating part of the right kidney and part of the suprarenal gland. It is located close to the right of the fossa between the bare area and the caudate lobe and immediately above the renal impression. The greater part of the suprarenal impression is devoid of peritoneum and it lodges the right suprarenal gland. This is caused by the descending portion of the duodenum, and is known as the duodenal impression. The lobules are roughly hexagonal, and consist of plates of hepatocytes radiating from a central vein. A distinctive component of a lobule is the portal triad, which can be found running along each of the lobule's corners. The portal triad, misleadingly named, consists of five structures: a branch of the hepatic artery, a branch of the hepatic portal vein, and a bile duct, as well as lymphatic vessels and a branch of the vagus nerve. Non- parenchymal cells constitute 4. The duct, vein, and artery divide into left and right branches, and the areas of the liver supplied by these branches constitute the functional left and right lobes. The functional lobes are separated by the imaginary plane, Cantlie's line, joining the gallbladder fossa to the inferior vena cava. The plane separates the liver into the true right and left lobes. The middle hepatic vein also demarcates the true right and left lobes. The right lobe is further divided into an anterior and posterior segment by the right hepatic vein. The left lobe is divided into the medial and lateral segments by the left hepatic vein. Couinaud classification system. Eight subsegments by Couinaud labelled. The medial segment is also called the quadrate lobe. In the widely used Couinaud (or . Each segment has its own vascular inflow, outflow and biliary drainage. In the centre of each segment there is a branch of the portal vein, hepatic artery and bile duct. In the periphery of each segment there is vascular outflow through the hepatic veins. This means that resection lines parallel the hepatic veins, leaving the portal veins, bile ducts, and hepatic arteries intact. It contains one or more hepatic veins which drain directly into the IVC. The origins of the liver lie in both the ventral portion of the foregutendoderm (endoderm being one of the 3 embryonic germ layers) and the constituents of the adjacent septum transversummesenchyme. In the human embryo, the hepatic diverticulum is the tube of endoderm that extends out from the foregut into the surrounding mesenchyme. The mesenchyme of septum transversum induces this endoderm to proliferate, to branch, and to form the glandular epithelium of the liver. A portion of the hepatic diverticulum (that region closest to the digestive tube) continues to function as the drainage duct of the liver, and a branch from this duct produces the gallbladder. The hepatic endodermal cells undergo a morphological transition from columnar to pseudostratified resulting in thickening into the early liver bud. Their expansion forms a population of the bipotential hepatoblasts. The liver bud separates into the lobes. The left umbilical vein becomes the ductus venosus and the right vitelline vein becomes the portal vein. The expanding liver bud is colonized by hematopoietic cells. The bipotential hepatoblasts begin differentiating into biliary epithelial cells and hepatocytes. The biliary epithelial cells differentiate from hepatoblasts around portal veins, first producing a monolayer, and then a bilayer of cuboidal cells. In ductal plate, focal dilations emerge at points in the bilayer, become surrounded by portal mesenchyme, and undergo tubulogenesis into intrahepatic bile ducts. Hepatoblasts not adjacent to portal veins instead differentiate into hepatocytes and arrange into cords lined by sinudoidal epithelial cells and bile canaliculi. Once hepatoblasts are specified into hepatocytes and undergo further expansion, they begin acquiring the functions of a mature hepatocyte, and eventually mature hepatocytes appear as highly polarized epithelial cells with abundant glycogen accumulation. In the adult liver, hepatocytes are not equivalent, with position along the portocentrovenular axis within a liver lobule dictating expression of metabolic genes involved in drug metabolism, carbohydrate metabolism, ammonia detoxification, and bile production and secretion. Over the course of further development, it will increase to 1. The umbilical vein enters the abdomen at the umbilicus, and passes upward along the free margin of the falciform ligament of the liver to the inferior surface of the liver. There it joins with the left branch of the portal vein. The ductus venosus carries blood from the left portal vein to the left hepatic vein and then to the inferior vena cava, allowing placental blood to bypass the liver. In the fetus, the liver does not perform the normal digestive processes and filtration of the infant liver because nutrients are received directly from the mother via the placenta. The fetal liver releases some blood stem cells that migrate to the fetal thymus, creating the T- cells or T- lymphocytes. After birth, the formation of blood stem cells shifts to the red bone marrow. After two to five days, the umbilical vein and ductus venosus are completely obliterated; the former becomes the round ligament of liver and the latter becomes the ligamentum venosum. In the disorders of cirrhosis and portal hypertension, the umbilical vein can open up again. Physiology. The liver is thought to be responsible for up to 5. Currently, there is no artificial organ or device capable of reproducing all the functions of the liver. Some functions can be carried out by liver dialysis, an experimental treatment for liver failure. Blood supply. The hepatic portal vein delivers approximately 7. The hepatic arteries supply arterial blood to the liver, accounting for the remaining quarter of its blood flow. Oxygen is provided from both sources; approximately half of the liver's oxygen demand is met by the hepatic portal vein, and half is met by the hepatic arteries. The central veins coalesce into hepatic veins, which leave the liver and drain into the inferior vena cava. The biliary tract, also known as the biliary tree, is the path by which bile is secreted by the liver then transported to the first part of the small intestine, the duodenum. The bile produced in the liver is collected in bile canaliculi, small grooves between the faces of adjacent hepatocytes. The canaliculi radiate to the edge of the liver lobule, where they merge to form bile ducts. Within the liver, these ducts are termed intrahepatic bile ducts, and once they exit the liver they are considered extrahepatic. The intrahepatic ducts eventually drain into the right and left hepatic ducts, which exit the liver at the transverse fissure, and merge to form the common hepatic duct. The cystic duct from the gallbladder joins with the common hepatic duct to form the common bile duct. The common bile duct and the pancreatic duct enter the second part of the duodenum together at the hepatopancreatic ampulla, also known as the ampulla of Vater. Synthesis. When needed, the liver releases glucose into the blood by performing glycogenolysis, the breakdown of glycogen into glucose. Adipose and liver cells produce glycerol by breakdown of fat, which the liver uses for gluconeogenesis. It is also responsible for a large part of amino acid synthesis. The liver plays a role in the production of clotting factors as well as red blood cell production.
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