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Azathioprine
Azathioprine (AZA), sold under the brand name Imuran, among others, is an immunosuppressive medication. It is used in rheumatoid arthritis, granulomatosis with polyangiitis, Crohn's disease, ulcerative colitis, and systemic lupus erythematosus, and in kidney transplants to prevent rejection. It is listed by the International Agency for Research on Cancer as a group 1 carcinogen (carcinogenic to humans). It is taken by mouth or injected into a vein. Common side effects include bone-marrow suppression and vomiting. Bone-marrow suppression is especially common in people with a genetic deficiency of the enzyme thiopurine S-methyltransferase. Other serious risk factors include an increased risk of certain cancers. Use during pregnancy may result in harm to the baby. Azathioprine is in the purine analogue and antimetabolite family of medications. It works via 6-thioguanine to disrupt the making of RNA and DNA by cells. Azathioprine was first made in 1957. It is on the World H ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thiopurine S-methyltransferase
Thiopurine methyltransferase or thiopurine S-methyltransferase (TPMT) is an enzyme that in humans is encoded by the ''TPMT'' gene. A pseudogene for this locus is located on chromosome 18q. Function Thiopurine methyltransferase methylates thiopurine compounds. The methyl donor is S-adenosyl-L-methionine, which is converted to S-adenosyl-L-homocysteine. This enzyme metabolizes thiopurine drugs via S-adenosyl-L-methionine as the S-methyl donor and S-adenosyl-L-homocysteine as a byproduct. Clinical significance Thiopurine drugs such as 6-mercaptopurine are used as chemotherapeutic agents and immunosuppressive drugs. Genetic polymorphisms that affect this enzymatic activity are correlated with variations in sensitivity and toxicity to such drugs within individuals. About 1/300 individual is deficient for the enzyme. Pharmacology TPMT is best known for its role in the metabolism of the thiopurine drugs such as azathioprine, 6-mercaptopurine and 6-thioguanine. TPMT ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Myasthenia Gravis
Myasthenia gravis (MG) is a long-term neuromuscular junction disease that leads to varying degrees of skeletal muscle weakness. The most commonly affected muscles are those of the eyes, face, and swallowing. It can result in double vision, drooping eyelids, trouble talking, and trouble walking. Onset can be sudden. Those affected often have a large thymus or develop a thymoma. Myasthenia gravis is an autoimmune disease of the neuro-muscular junction which results from antibodies that block or destroy nicotinic acetylcholine receptors (AChR) at the junction between the nerve and muscle. This prevents nerve impulses from triggering muscle contractions. Most cases are due to immunoglobulin G1 (IgG1) and IgG3 antibodies that attack AChR in the postsynaptic membrane, causing complement-mediated damage and muscle weakness. Rarely, an inherited genetic defect in the neuromuscular junction results in a similar condition known as congenital myasthenia. Babies of mothers with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Immunosuppressive Medication
Immunosuppressive drugs, also known as immunosuppressive agents, immunosuppressants and antirejection medications, are drugs that inhibit or prevent activity of the immune system. Classification Immunosuppressive drugs can be classified into five groups: * glucocorticoids * cytostatics * antibodies * drugs acting on immunophilins * other drugs Glucocorticoids In pharmacologic (supraphysiologic) doses, glucocorticoids, such as prednisone, dexamethasone, and hydrocortisone are used to suppress various allergic, inflammatory, and autoimmune disorders. They are also administered as posttransplantory immunosuppressants to prevent the acute transplant rejection and graft-versus-host disease. Nevertheless, they do not prevent an infection and also inhibit later reparative processes. Immunosuppressive mechanism Glucocorticoids suppress cell-mediated immunity. They act by inhibiting genes that code for the cytokines Interleukin 1 (IL-1), IL-2, IL-3, IL-4, IL-5, IL-6, IL-8, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
WHO Model List Of Essential Medicines
The WHO Model List of Essential Medicines (aka Essential Medicines List or EML), published by the World Health Organization (WHO), contains the medications considered to be most effective and safe to meet the most important needs in a health system. The list is frequently used by countries to help develop their own local lists of essential medicines. , more than 155 countries have created national lists of essential medicines based on the World Health Organization's model list. This includes both developed and developing countries. The list is divided into core items and complementary items. The core items are deemed to be the most cost-effective options for key health problems and are usable with little additional health care resources. The complementary items either require additional infrastructure such as specially trained health care providers or diagnostic equipment or have a lower cost–benefit ratio. About 25% of items are in the complementary list. Some medica ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transplant Rejection
Transplant rejection occurs when transplanted tissue is rejected by the recipient's immune system, which destroys the transplanted tissue. Transplant rejection can be lessened by determining the molecular similitude between donor and recipient and by use of immunosuppressant drugs after transplant. Types of transplant rejection Transplant rejection can be classified into three types: hyperacute, acute, and chronic. These types are differentiated by how quickly the recipient's immune system is activated and the specific aspect or aspects of immunity involved. Hyperacute rejection Hyperacute rejection is a form of rejection that manifests itself in the minutes to hours following transplantation. It is caused by the presence of pre-existing antibodies in the recipient that recognize antigens in the donor organ. These antigens are located on the endothelial lining of blood vessels within the transplanted organ and, once antibodies bind, will lead to the rapid activation of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antimetabolite
An antimetabolite is a chemical that inhibits the use of a metabolite, which is another chemical that is part of normal metabolism. Such substances are often similar in structure to the metabolite that they interfere with, such as the antifolates that interfere with the use of folic acid; thus, competitive inhibition can occur, and the presence of antimetabolites can have toxic effects on cells, such as halting cell growth and cell division, so these compounds are used as chemotherapy for cancer. Function Cancer treatment Antimetabolites can be used in cancer treatment, as they interfere with DNA production and therefore cell division and tumor growth. Because cancer cells spend more time dividing than other cells, inhibiting cell division harms tumor cells more than other cells. Antimetabolite drugs are commonly used to treat leukemia, cancers of the breast, ovary, and the gastrointestinal tract, as well as other types of cancers. In the Anatomical Therapeutic Chemical Cla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
6-thioguanine
Tioguanine, also known as thioguanine or 6-thioguanine (6-TG) is a medication used to treat acute myeloid leukemia (AML), acute lymphocytic leukemia (ALL), and chronic myeloid leukemia (CML). Long-term use is not recommended. It is given by mouth. Common side effects include bone marrow suppression, liver problems and inflammation of the mouth. It is recommended that liver enzymes be checked weekly when on the medication. People with a genetic deficiency in thiopurine S-methyltransferase are at higher risk of side effects. Avoiding pregnancy when on the medication is recommended for both males and females. Tioguanine is in the antimetabolite family of medications. It is a purine analogue of guanine and works by disrupting DNA and RNA. Tioguanine was developed between 1949 and 1951. It is on the World Health Organization's List of Essential Medicines. Medical uses * Acute leukemias in both adults and children *Chronic myelogenous leukemia *Inflammatory bowel diseas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bone Marrow Suppression
Bone marrow suppression also known as myelotoxicity or myelosuppression, is the decrease in production of cells responsible for providing immunity (leukocytes), carrying oxygen ( erythrocytes), and/or those responsible for normal blood clotting ( thrombocytes). Bone marrow suppression is a serious side effect of chemotherapy and certain drugs affecting the immune system such as azathioprine. The risk is especially high in cytotoxic chemotherapy for leukemia. Nonsteroidal anti-inflammatory drugs (NSAIDs), in some rare instances, may also cause bone marrow suppression. The decrease in blood cell counts does not occur right at the start of chemotherapy because the drugs do not destroy the cells already in the bloodstream (these are not dividing rapidly). Instead, the drugs affect new blood cells that are being made by the bone marrow. When myelosuppression is severe, it is called myeloablation. Many other drugs including common antibiotics may cause bone marrow suppression. Unlike ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ulcerative Colitis
Ulcerative colitis (UC) is a long-term condition that results in inflammation and ulcers of the colon and rectum. The primary symptoms of active disease are abdominal pain and diarrhea mixed with blood ( hematochezia). Weight loss, fever, and anemia may also occur. Often, symptoms come on slowly and can range from mild to severe. Symptoms typically occur intermittently with periods of no symptoms between flares. Complications may include abnormal dilation of the colon (megacolon), inflammation of the eye, joints, or liver, and colon cancer. The cause of UC is unknown. Theories involve immune system dysfunction, genetics, changes in the normal gut bacteria, and environmental factors. Rates tend to be higher in the developed world with some proposing this to be the result of less exposure to intestinal infections, or to a Western diet and lifestyle. The removal of the appendix at an early age may be protective. Diagnosis is typically by colonoscopy with tissue biopsies. I ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Purine Analogue
Purine analogues are antimetabolites that mimic the structure of metabolic purines. Examples *Nucleobase analogues **Thiopurines such as thioguanine are used to treat acute leukemias and remissions in acute granulocytic leukemias. *** Azathioprine is the main immunosuppressive cytotoxic substance. A prodrug, it is widely used in transplantation to control rejection reactions. It is nonenzymatically cleaved to mercaptopurine, a purine analogue that inhibits DNA synthesis. By preventing the clonal expansion of lymphocytes in the induction phase of the immune response, it affects both cell immunity and humoral immunity. It also successfully suppresses autoimmunity. *** Mercaptopurine *** Thioguanine * Nucleoside analogues **Clofarabine **Pentostatin and cladribine are adenosine analogs that are used primarily to treat hairy cell leukemia. *Nucleotide analogues **Fludarabine inhibits multiple DNA polymerases, DNA primase, and DNA ligase I, and is S phase-specific (since these en ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crohn's Disease
Crohn's disease is a type of inflammatory bowel disease (IBD) that may affect any segment of the gastrointestinal tract. Symptoms often include abdominal pain, diarrhea (which may be bloody if inflammation is severe), fever, abdominal distension, and weight loss. Complications outside of the gastrointestinal tract may include anemia, skin rashes, arthritis, inflammation of the eye, and fatigue. The skin rashes may be due to infections as well as pyoderma gangrenosum or erythema nodosum. Bowel obstruction may occur as a complication of chronic inflammation, and those with the disease are at greater risk of colon cancer and small bowel cancer. While the precise causes of Crohn's disease (CD) are unknown, it is believed to be caused by a combination of environmental, immune, and bacterial factors in genetically susceptible individuals. It results in a chronic inflammatory disorder, in which the body's immune system defends the gastrointestinal tract, possibly targeting microbial ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Behçet's Disease
Behçet's disease (BD) is a type of inflammatory disorder which affects multiple parts of the body. The most common symptoms include painful sores on the mucous membranes of the mouth and other parts of the body, inflammation of parts of the eye, and arthritis. The sores can last from a few days, up to a week or more. Less commonly there may be inflammation of the brain or spinal cord, blood clots, aneurysms, or blindness. Often, the symptoms come and go. The cause is unknown. It is believed to be partly genetic. Behçet's is not contagious. Diagnosis is based on at least three episodes of mouth sores in a year together with at least two of the following: genital sores, eye inflammation, skin sores, a positive skin prick test. There is no cure. Treatments may include immunosuppressive medication such as corticosteroids and lifestyle changes. Lidocaine mouthwash may help with the pain. Colchicine may decrease the frequency of attacks. While rare in the United States ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
