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Glucagonoma
Glucagonoma is a very rare tumor of the pancreatic alpha cells that results in the overproduction of the hormone, glucagon. Typically associated with a rash called necrolytic migratory erythema, weight loss, and mild diabetes mellitus, most people with glucagonoma contract it spontaneously. However, about 10% of cases are associated with multiple endocrine neoplasia type 1 (MEN-1) syndrome. Causes Although the cause of glucagonoma is unknown, some genetic factors may lead to the condition. A family history of multiple endocrine neoplasia type 1 (MEN1) is a risk factor. Additionally, those with Mahvash disease have an increased risk for glucagonoma, as the glucagon receptor gene (GCGR) is mutated. Mechanism Glucagonoma results from the overproduction of glucagon, a peptide hormone located in the pancreatic alpha cells. Classic symptoms include, but are not limited to, necrolytic migratory erythema (NME), diabetes mellitus, and weight loss. NME presents in about 70% of cases of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glucagon
Glucagon is a peptide hormone, produced by alpha cells of the pancreas. It raises concentration of glucose and fatty acids in the bloodstream, and is considered to be the main catabolic hormone of the body. It is also used as a medication to treat a number of health conditions. Its effect is opposite to that of insulin, which lowers extracellular glucose. It is produced from proglucagon, encoded by the ''GCG'' gene. The pancreas releases glucagon when the amount of glucose in the bloodstream is too low. Glucagon causes the liver to engage in glycogenolysis: converting stored glycogen into glucose, which is released into the bloodstream. High blood-glucose levels, on the other hand, stimulate the release of insulin. Insulin allows glucose to be taken up and used by insulin-dependent tissues. Thus, glucagon and insulin are part of a feedback system that keeps blood glucose levels stable. Glucagon increases energy expenditure and is elevated under conditions of stress. Glucagon belo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alpha Cell
Alpha cells (α cells) are endocrine cells that are found in the Islets of Langerhans in the pancreas. Alpha cells secrete the peptide hormone glucagon in order to increase glucose levels in the blood stream. Discovery Islets of Langerhans were first discussed by Paul Langerhans in his medical thesis in 1869. This same year, Laguesse named them after Langerhans. At first, there was a lot of controversy about what the Islets were made of and what they did. It appeared that all of the cells were the same within the Islet, but were histologically distinct from acini cells. Laguesse discovered that the cells within the Islets of Langerhans contained granules that distinguished them from acini cells. He also determined that these granules were products of the metabolism of the cells in which they were contained. Michael Lane was the one to discover that alpha cells were histologically different than beta cells in 1907. Before the function of alpha cells was discovered, the function of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oncology
Oncology is a branch of medicine that deals with the study, treatment, diagnosis and prevention of cancer. A medical professional who practices oncology is an ''oncologist''. The name's etymological origin is the Greek word ὄγκος (''ónkos''), meaning "tumor", "volume" or "mass". Oncology is concerned with: * The diagnosis of any cancer in a person (pathology) * Therapy (e.g. surgery, chemotherapy, radiotherapy and other modalities) * Follow-up of cancer patients after successful treatment * Palliative care of patients with terminal malignancies * Ethical questions surrounding cancer care * Screening efforts: ** of populations, or ** of the relatives of patients (in types of cancer that are thought to have a hereditary basis, such as breast cancer) Diagnosis Medical histories remain an important screening tool: the character of the complaints and nonspecific symptoms (such as fatigue, weight loss, unexplained anemia, fever of unknown origin, paraneoplasti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tumor
A neoplasm () is a type of abnormal and excessive growth of tissue. The process that occurs to form or produce a neoplasm is called neoplasia. The growth of a neoplasm is uncoordinated with that of the normal surrounding tissue, and persists in growing abnormally, even if the original trigger is removed. This abnormal growth usually forms a mass, when it may be called a tumor. ICD-10 classifies neoplasms into four main groups: benign neoplasms, in situ neoplasms, malignant neoplasms, and neoplasms of uncertain or unknown behavior. Malignant neoplasms are also simply known as cancers and are the focus of oncology. Prior to the abnormal growth of tissue, as neoplasia, cells often undergo an abnormal pattern of growth, such as metaplasia or dysplasia. However, metaplasia or dysplasia does not always progress to neoplasia and can occur in other conditions as well. The word is from Ancient Greek 'new' and 'formation, creation'. Types A neoplasm can be benign, potentially m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hormone
A hormone (from the Greek participle , "setting in motion") is a class of signaling molecules in multicellular organisms that are sent to distant organs by complex biological processes to regulate physiology and behavior. Hormones are required for the correct development of animals, plants and fungi. Due to the broad definition of a hormone (as a signaling molecule that exerts its effects far from its site of production), numerous kinds of molecules can be classified as hormones. Among the substances that can be considered hormones, are eicosanoids (e.g. prostaglandins and thromboxanes), steroids (e.g. oestrogen and brassinosteroid), amino acid derivatives (e.g. epinephrine and auxin), protein or peptides (e.g. insulin and CLE peptides), and gases (e.g. ethylene and nitric oxide). Hormones are used to communicate between organs and tissues. In vertebrates, hormones are responsible for regulating a variety of physiological processes and behavioral activities such ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Necrolytic Migratory Erythema
Necrolytic migratory erythema is a red, blistering rash that spreads across the skin. It particularly affects the skin around the mouth and distal extremities; but may also be found on the lower abdomen, buttocks, perineum, and groin. It is strongly associated with glucagonoma, a glucagon-producing tumor of the pancreas, but is also seen in a number of other conditions including liver disease and intestinal malabsorption. Signs and symptoms Clinical features NME features a characteristic skin eruption of red patches with irregular borders, intact and ruptured vesicles, and crust formation. It commonly affects the limbs and skin surrounding the lips, although less commonly the abdomen, perineum, thighs, buttocks, and groin may be affected. Frequently these areas may be left dry or fissured as a result. All stages of lesion development may be observed synchronously. The initial eruption may be exacerbated by pressure or trauma to the affected areas. Associated conditions Will ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Multiple Endocrine Neoplasia Type 1
Multiple endocrine neoplasia type 1 (MEN-1) is one of a group of disorders, the multiple endocrine neoplasias, that affect the endocrine system through development of neoplastic lesions in pituitary, parathyroid gland and pancreas. It was first described by Paul Wermer in 1954. Signs and symptoms Parathyroid Hyperparathyroidism is present in ≥ 90% of patients. Asymptomatic hypercalcemia is the most common manifestation: about 25% of patients have evidence of nephrolithiasis or nephrocalcinosis. In contrast to sporadic cases of hyperparathyroidism, diffuse hyperplasia or multiple adenomas are more common than solitary adenomas. Pancreas Pancreatic islet cell tumors are today the major cause of death in persons with MEN-1. Tumors occur in 60-80% of persons with MEN-1 and they are usually multicentric. Multiple adenomas or diffuse islet cell hyperplasia commonly occurs. About 30% of tumors are malignant and have local or distant metastases. About 10-15% of islet cell tumors origi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mahvash Disease
Mahvash disease is an autosomal recessive, hereditary pancreatic neuroendocrine tumor syndrome. The genetic defect that causes Mahvash disease is biallelic inactivating mutations of the glucagon receptor gene (''GCGR''). Mahvash disease was discovered by American physician Run Yu and his colleagues in 2008. Mahvash disease is very rare. There have been over 10 cases of Mahvash disease described by the end of 2018. Mahvash disease occurs in both females and males. Mahvash disease is also called “glucagon cell hyperplasia and neoplasia” or “glucagon cell adenomatosis” by some authors but Mahvash disease is a distinct disease entity while the two alternative terms are mostly histological descriptions. Some patients with “glucagon cell hyperplasia and neoplasia” do not have glucagon receptor mutations. Signs and symptoms Most patients with Mahvash disease are diagnosed in adulthood. Patients with Mahvash disease usually present with vague abdominal discomfort. Imaging wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glucagon Receptor
The glucagon receptor is a 62 kDa protein that is activated by glucagon and is a member of the class B G-protein coupled family of receptors, coupled to G alpha i, Gs and to a lesser extent G alpha q. Stimulation of the receptor results in the activation of adenylate cyclase and phospholipase C and in increased levels of the secondary messengers intracellular cAMP and calcium. In humans, the glucagon receptor is encoded by the gene. Glucagon receptors are mainly expressed in liver and in kidney with lesser amounts found in heart, adipose tissue, spleen, thymus, adrenal glands, pancreas, cerebral cortex, and gastrointestinal tract. Signal transduction pathway A glucagon receptor, upon binding with the signaling molecule glucagon, initiates a signal transduction pathway that begins with the activation of adenylate cyclase, which in turn produces cyclic AMP (cAMP). Protein kinase A, whose activation is dependent on the increased levels of cAMP, is responsible for the ensuin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peptide
Peptides (, ) are short chains of amino acids linked by peptide bonds. Long chains of amino acids are called proteins. Chains of fewer than twenty amino acids are called oligopeptides, and include dipeptides, tripeptides, and tetrapeptides. A polypeptide is a longer, continuous, unbranched peptide chain. Hence, peptides fall under the broad chemical classes of biological polymers and oligomers, alongside nucleic acids, oligosaccharides, polysaccharides, and others. A polypeptide that contains more than approximately 50 amino acids is known as a protein. Proteins consist of one or more polypeptides arranged in a biologically functional way, often bound to ligands such as coenzymes and cofactors, or to another protein or other macromolecule such as DNA or RNA, or to complex macromolecular assemblies. Amino acids that have been incorporated into peptides are termed residues. A water molecule is released during formation of each amide bond.. All peptides except cyc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Insulin
Insulin (, from Latin ''insula'', 'island') is a peptide hormone produced by beta cells of the pancreatic islets encoded in humans by the ''INS'' gene. It is considered to be the main anabolic hormone of the body. It regulates the metabolism of carbohydrates, fats and protein by promoting the absorption of glucose from the blood into liver, fat and skeletal muscle cells. In these tissues the absorbed glucose is converted into either glycogen via glycogenesis or fats (triglycerides) via lipogenesis, or, in the case of the liver, into both. Glucose production and secretion by the liver is strongly inhibited by high concentrations of insulin in the blood. Circulating insulin also affects the synthesis of proteins in a wide variety of tissues. It is therefore an anabolic hormone, promoting the conversion of small molecules in the blood into large molecules inside the cells. Low insulin levels in the blood have the opposite effect by promoting widespread catabolism, especial ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kidney Failure
Kidney failure, also known as end-stage kidney disease, is a medical condition in which the kidneys can no longer adequately filter waste products from the blood, functioning at less than 15% of normal levels. Kidney failure is classified as either acute kidney failure, which develops rapidly and may resolve; and chronic kidney failure, which develops slowly and can often be irreversible. Symptoms may include leg swelling, feeling tired, vomiting, loss of appetite, and confusion. Complications of acute and chronic failure include uremia, high blood potassium, and volume overload. Complications of chronic failure also include heart disease, high blood pressure, and anemia. Causes of acute kidney failure include low blood pressure, blockage of the urinary tract, certain medications, muscle breakdown, and hemolytic uremic syndrome. Causes of chronic kidney failure include diabetes, high blood pressure, nephrotic syndrome, and polycystic kidney disease. Diagnosis of acute f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
