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Allopurinol
Allopurinol is a medication used to decrease high blood uric acid levels. It is specifically used to prevent gout, prevent specific types of kidney stones and for the high uric acid levels that can occur with chemotherapy. It is taken by mouth or injected into a vein. Common side effects when used by mouth include itchiness and rash. Common side effects when used by injection include vomiting and kidney problems. While not recommended historically, starting allopurinol during an attack of gout appears to be safe. In those already on the medication, it should be continued even during an acute gout attack. While use during pregnancy does not appear to result in harm, this use has not been well studied. Allopurinol is in the xanthine oxidase inhibitor family of medications. Allopurinol was approved for medical use in the United States in 1966. It is on the World Health Organization's List of Essential Medicines. Allopurinol is available as a generic medication. In 2020, it was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gout
Gout ( ) is a form of inflammatory arthritis characterized by recurrent attacks of a red, tender, hot and swollen joint, caused by deposition of monosodium urate monohydrate crystals. Pain typically comes on rapidly, reaching maximal intensity in less than 12 hours. The joint at the base of the big toe is affected in about half of cases. It may also result in tophi, kidney stones, or kidney damage. Gout is due to persistently elevated levels of uric acid in the blood. This occurs from a combination of diet, other health problems, and genetic factors. At high levels, uric acid crystallizes and the crystals deposit in joints, tendons, and surrounding tissues, resulting in an attack of gout. Gout occurs more commonly in those who: regularly drink beer or sugar-sweetened beverages; eat foods that are high in purines such as liver, shellfish, or anchovies; or are overweight. Diagnosis of gout may be confirmed by the presence of crystals in the joint fluid or in a deposit outsid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lesch–Nyhan Syndrome
Lesch–Nyhan syndrome (LNS) is a rare inherited disorder caused by a deficiency of the enzyme hypoxanthine-guanine phosphoribosyltransferase (HGPRT). This deficiency occurs due to mutations in the ''HPRT1'' gene located on the X chromosome. LNS affects about 1 in 380,000 live births. The disorder was first recognized and clinically characterized by American medical student Michael Lesch and his mentor, pediatrician William Nyhan, at Johns Hopkins. The HGPRT deficiency causes a build-up of uric acid in all body fluids. The combination of increased synthesis and decreased utilization of purines leads to high levels of uric acid production. This results in both high levels of uric acid in the blood and urine, associated with severe gout and kidney problems. Neurological signs include poor muscle control and moderate intellectual disability. These complications usually appear in the first year of life. Beginning in the second year of life, a particularly striking feature of LNS is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kidney Stones
Kidney stone disease, also known as nephrolithiasis or urolithiasis, is a crystallopathy where a solid piece of material (kidney stone) develops in the urinary tract. Kidney stones typically form in the kidney and leave the body in the urine stream. A small stone may pass without causing symptoms. If a stone grows to more than , it can cause blockage of the ureter, resulting in sharp and severe pain in the lower back or abdomen. A stone may also result in blood in the urine, vomiting, or painful urination. About half of people who have had a kidney stone will have another within ten years. Most stones form by a combination of genetics and environmental factors. Risk factors include high urine calcium levels, obesity, certain foods, some medications, calcium supplements, hyperparathyroidism, gout and not drinking enough fluids. Stones form in the kidney when minerals in urine are at high concentration. The diagnosis is usually based on symptoms, urine testing, and medical ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxipurinol
Oxipurinol (INN, or oxypurinol USAN) is an inhibitor of xanthine oxidase. It is an active metabolite of allopurinol and it is cleared renally. In cases of renal disease, this metabolite will accumulate to toxic levels. By inhibiting xanthine oxidase, it reduces uric acid production. High serum uric acid levels may result in gout, kidney stones Kidney stone disease, also known as nephrolithiasis or urolithiasis, is a crystallopathy where a calculus (medicine), solid piece of material (kidney stone) develops in the urinary tract. Kidney stones typically form in the kidney and leave the ..., and other medical conditions. References Pyrazolopyrimidines Xanthine oxidase inhibitors Human drug metabolites {{heterocyclic-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hyperuricemia
Hyperuricaemia or hyperuricemia is an abnormally high level of uric acid in the blood. In the pH conditions of body fluid, uric acid exists largely as urate, the ion form. Serum uric acid concentrations greater than 6 mg/dL for females, 7 mg/dL for men, and 5.5 mg/dL for youth (under 18 years old) are defined as hyperuricemia. The amount of urate in the body depends on the balance between the amount of purines eaten in food, the amount of urate synthesised within the body (e.g., through cell turnover), and the amount of urate that is excreted in urine or through the gastrointestinal tract. Hyperuricemia may be the result of increased production of uric acid, decreased excretion of uric acid, or both increased production and reduced excretion. Signs and symptoms Unless high blood levels of uric acid are determined in a clinical laboratory, hyperuricemia may not cause noticeable symptoms in most people. Development of gout which is a painful, short-term disorder is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xanthine Oxidase Inhibitor
A xanthine oxidase inhibitor is any substance that inhibits the activity of xanthine oxidase, an enzyme involved in purine metabolism. In humans, inhibition of xanthine oxidase reduces the production of uric acid, and several medications that inhibit xanthine oxidase are indicated for treatment of hyperuricemia and related medical conditions including gout. Xanthine oxidase inhibitors are being investigated for management of reperfusion injury. Xanthine oxidase inhibitors are of two kinds: purine analogues and others. Purine analogues include allopurinol, oxypurinol, and tisopurine. Others include febuxostat, topiroxostat, and inositols (phytic acid and myo-inositol). In experiments, numerous natural products have been found to inhibit xanthine oxidase in vitro or in model animals (mice, rats). These include three flavonoids that occur in many different fruits and vegetables: kaempferol, myricetin, and quercetin. More generally, planar flavones and flavonols with a 7-hydro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adenine Phosphoribosyltransferase
Adenine phosphoribosyltransferase (APRTase) is an enzyme encoded by the ''APRT'' gene, found in humans on chromosome 16. It is part of the Type I PRTase family and is involved in the nucleotide salvage pathway, which provides an alternative to nucleotide biosynthesis de novo in humans and most other animals. In parasitic protozoa such as giardia, APRTase provides the sole mechanism by which AMP can be produced. APRTase deficiency contributes to the formation of kidney stones (urolithiasis) and to potential kidney failure. Function APRTase catalyzes the following reaction in the purine nucleotide salvage pathway: Adenine + Phosphoribosyl Pyrophosphate (PRPP) → Adenylate (AMP) + Pyrophosphate ( PPi) In organisms that can synthesize purines de novo, the nucleotide salvage pathway provides an alternative that is energetically more efficient. It can salvage adenine from the polyamine biosynthetic pathway or from dietary sources of purines. Although APRTase is functionally re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tumor Lysis Syndrome
Tumor lysis syndrome (TLS) is a group of metabolic abnormalities that can occur as a complication from the treatment of cancer, where large amounts of tumor cells are killed off ( lysed) from the treatment, releasing their contents into the bloodstream. This occurs most commonly after the treatment of lymphomas and leukemias and in particular when treating non-Hodgkin lymphoma, acute myeloid leukemia, and acute lymphoblastic leukemia. This is a potentially fatal complication and patients at increased risk for TLS should be closely monitored while receiving chemotherapy and should receive preventive measures and treatments as necessary. TLS can also occur on its own (while not being treated with chemotherapy) although this is less common. Tumor lysis syndrome is characterized by high blood potassium (hyperkalemia), high blood phosphate (hyperphosphatemia), low blood calcium (hypocalcemia), high blood uric acid (hyperuricemia), and higher than normal levels of blood urea nitrogen (B ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tophus
A tophus (Latin: "stone", plural tophi) is a deposit of monosodium urate crystals, in people with longstanding high levels of uric acid in the blood, a condition known as hyperuricemia. Tophi are pathognomonic for the disease gout. Most people with tophi have had previous attacks of acute arthritis, eventually leading to the formation of tophi. Chronic tophaceous gout is known as Harrison Syndrome. Tophi form in the joints, cartilage, bones, and other places throughout the body. Sometimes, tophi break through the skin and appear as white or yellowish-white, chalky nodules. Without treatment, tophi may develop on average about ten years after the onset of gout, although their first appearance can range from three to forty-two years. The development of gouty tophi can also limit joint function and cause bone destruction, leading to noticeable disabilities, especially when gout cannot successfully be treated. When uric acid levels and gout symptoms cannot be controlled with standard ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thiopurine 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 cataly ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glycogen Storage Disease
A glycogen storage disease (GSD, also glycogenosis and dextrinosis) is a metabolic disorder caused by an enzyme deficiency affecting glycogen synthesis, glycogen breakdown, or glucose breakdown, typically in muscles and/or liver cells. GSD has two classes of cause: genetic and acquired. Genetic GSD is caused by any inborn error of metabolism (genetically defective enzymes) involved in these processes. In livestock, acquired GSD is caused by intoxication with the alkaloid castanospermine. Types Remarks: * Some GSDs have different forms, e.g. infantile, juvenile, adult (late-onset). * Some GSDs have different subtypes, e.g. GSD1a / GSD1b, GSD9A1 / GSD9A2 / GSD9B / GSD9C / GSD9D. * GSD type 0: Although glycogen synthase deficiency does not result in storage of extra glycogen in the liver, it is often classified with the GSDs as type 0 because it is another defect of glycogen storage and can cause similar problems. * GSD type VIII (GSD 8): In the past it was considered a distin ... [...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] |
