Methemoglobin British English methaemoglobin pronounced MET hemoglobin is a form of the oxygen carrying protein hemoglobin , in which the iron in the heme group is in the Fe sup 3 sup ferric state, not the Fe sup 2 sup ferrous of normal hemoglobin. Methemoglobin cannot carry oxygen. It is a bluish chocolate brown in color. The NADH dependent enzyme methemoglobin reductase diaphorase I is responsible for converting methemoglobin back to hemoglobin. Normally one to two percent of people s hemoglobin is methemoglobin a higher percentage than this can be genetic or caused by exposure to various chemicals and depending on the level can cause health problems known as methemoglobinemia . A higher level of methemoglobin will tend to cause a pulse oximeter to read closer to 85 regardless of the true level of oxygen saturation. ref cite web url http www.emedicine.com med TOPIC1466.HTM accessdate 2008 03 31 last Denshaw Burke first Mary date 2006 11 07 title Methemoglobinema ref Common causes Reduced cellular defense mechanisms Children younger than 4 months exposed to various environmental agents Cytochrome b5 reductase deficiency Glucose 6 phosphate dehydrogenase deficiency G6PD deficiency Hemoglobin M disease Pyruvate kinase deficiency Various pharmaceutical compounds Local anesthetic agents, especially prilocaine as used in the Bier block Amyl nitrite , chloroquine , dapsone , nitrates ... to treat cyanide poisoning. It works by converting hemoglobin to methemoglobin, which allows for the binding ... Toxicology journal Toxicology year 2001 volume 168 issue 1 pages 37 38 ref Methemoglobin saturation Methemoglobin saturation is expressed as the percentage of hemoglobin in the methemoglobin state That is MetHb ... reflist 1 External links MeshName Methemoglobin http books.google.ca books?id 09WL4spDvZ8C&pg ... cs Methemoglobin da M th moglobin de Meth moglobin es Metahemoglobina fr M th moglobine it Metaemoglobina ja pl Methemoglobina pt Meta hemoglobina fi Methemoglobiini sv Methemoglobin ... more details
enzyme Name cytochrome b5 reductase EC number 1.6.2.2 CAS number 9032 25 1 IUBMB EC number 1 6 2 2 GO code 0004128 image NADH cytochrome B5 reductase 1UMK.png width caption Ribbon diagram of red blood cell erythrocytic methemoglobin reductase with FAD bound. From PDB 1UMK . Cytochrome b sub 5 sub reductase also known as methemoglobin reductase is a NADH dependent enzyme that converts methemoglobin to hemoglobin . It contains FAD and catalyzes the reaction center NADH H sup sup 2 ferricytochrome b sub 5 sub NAD sup sup 2 ferrocytochrome b sub 5 sub center The following four human genes encode cytochrome b sub 5 sub reductases CYB5R1 CYB5R2 CYB5R3 CYB5R4 See also Cytochrome b5 Methemoglobinemia Reductase External links MeshName Cytochrome B 5 Reductase PDB 1IB0 crystal structure of rat CBR complexed with NAD PDB 1NDH crystal structure of pig liver CBR PDB 1UMK crystal structure of human erythrocyte CBR InterPro IPR001834 InterPro entry for CBR NADH or NADPH oxidoreductases Flavoproteins Category EC 1.6.2 de Cytochrom b5 Reduktasen it Citocromo b5 reduttasi ja b5 ... more details
characterized by the presence of a higher than normal level of methemoglobin metHb in the blood . Methemoglobin ... to the left. When methemoglobin concentration is elevated in red blood cells , tissue hypoxia can occur. Overview Normally, methemoglobin levels are 1 , as measured by the co oximetry test. Elevated levels of methemoglobin in the blood are caused when the mechanisms that defend against oxidative ... hemoglobin to methemoglobin, resulting in a reduced ability to release oxygen to tissues and thereby hypoxia. This can give the blood a bluish or chocolate brown color. Spontaneous formation of methemoglobin is normally reduced via electron donation by protective enzyme systems, e.g. NADH methemoglobin reductase cytochrome b5 reductase major pathway , NADPH methemoglobin reductase minor pathway and to a lesser ... to a deficiency of the enzyme diaphorase I NADH methemoglobin reductase , methemoglobin levels rise ... normally present in red blood cells maintain methemoglobin levels at less than one percent of the total ... , dapsone and nitrate s may accelerate the rate of formation of methemoglobin up to one thousandfold, overwhelming the protective enzyme systems and acutely increasing methemoglobin levels ... electron acceptor such as methylene blue, or flavin for NADPH methemoglobin reductase RBCs ... ref Yubisui T Takeshita M Yoneyama Y. Reduction of methemoglobin through flavin at the physiological ... methemoglobin 1 include shortness of breath, cyanosis , mental status changes 50 ... methemoglobin levels has a characteristic chocolate brown color as compared to normal bright ... methemoglobin 50 patients have dysrhythmias, seizures, coma and death 70 . ref name emedmed1466 Healthy people may not have many symptoms with methemoglobin levels 15 , however patients with co morbidities ... more details
Distinguish 4 Dimethylaminopyridine chembox verifiedrevid 399320064 ImageFile 4 Dimethylaminophenol.svg ImageSize 75px IUPACName OtherNames Section1 Chembox Identifiers ChemSpiderID Ref chemspidercite correct chemspider ChemSpiderID 20816 InChI 1 C8H11NO c1 9 2 7 3 5 8 10 6 4 7 h3 6,10H,1 2H3 InChIKey JVVRCYWZTJLJSG UHFFFAOYAU StdInChI Ref stdinchicite correct chemspider StdInChI 1S C8H11NO c1 9 2 7 3 5 8 10 6 4 7 h3 6,10H,1 2H3 StdInChIKey Ref stdinchicite correct chemspider StdInChIKey JVVRCYWZTJLJSG UHFFFAOYSA N CASNo 619 60 3 PubChem 22174 SMILES Oc1ccc N C C cc1 Section2 Chembox Properties Formula C sub 8 sub H sub 11 sub NO MolarMass 137.179 g mol Appearance Density MeltingPt BoilingPt 165 C 0.040 bar Solubility Section3 Chembox Hazards MainHazards FlashPt Autoignition 4 Dimethylaminophenol abbreviated in medical practice as DMAP is an aromatic compound containing both phenol and amine functional groups. It has the molecular formula C sub 8 sub H sub 11 sub NO. Uses 4 Dimethylaminophenol has been used as an antidote for cyanide poisoning . ref name pmid11121929 cite journal author Kampe S, Iffland R, Korenkov M, Diefenbach C title Survival from a lethal blood concentration of cyanide with associated alcohol intoxication journal Anaesthesia volume 55 issue 12 pages 1189 91 year 2000 month December pmid 11121929 doi 10.1046 j.1365 2044.2000.01628.x url http www3.interscience.wiley.com resolve openurl?genre article&sid nlm pubmed&issn 0003 2409&date 2000&volume 55&issue 12&spage 1189 ref It works by generating methemoglobin . ref name pmid8956097 cite journal author Vick JA, Von Bredow JD title Effectiveness of intramuscularly administered cyanide antidotes on methemoglobin formation and survival journal J Appl Toxicol volume 16 issue 6 pages 509 16 year 1996 pmid 8956097 doi 10.1002 SICI 1099 1263 199611 16 6 509 AID JAT382 3.0.CO 2 V url ref This is suitable as an emergency treatment only treatment must be followed up with sodium thiosulfate or cobalamin . In a ... more details
s iron from the ferrous state to the ferric state, converting the hemoglobin into methemoglobin . Citation needed date May 2010 Treatment with alkyl nitrite nitrite s is not innocuous as methemoglobin ... . Cyanide preferentially bonds to methemoglobin rather than the cytochrome oxidase , converting methemoglobin ... and within the cells to combat cyanide intoxication. This versatility contrasts with methemoglobin ... of 3 mg kg of 4 DMAP produces 35 percent methemoglobin levels within 1 minute. Reportedly ... provides an antidote effect more quickly than formation of methemoglobin, but a clear superiority to methemoglobin formation has not been demonstrated. Cobalt Complex chemistry complexes are quite ... more details
Image Co monitor.JPG thumb Finger tip carboxyhemoglobin saturation monitor. A CO oximeter is a device for detecting Hypoxia medical hypoxia , a medical condition relating to oxygen deficiency at tissue level . The device measures absorption at several wavelengths to distinguish oxyhemoglobin from carboxyhemoglobin and determine the oxyhemoglobin saturation the percentage of oxygenated Hb compared to the total amount of hemoglobin Hb , including carboxy Hb, met Hb, oxy Hb, and reduced Hb. When a patient presents with carbon monoxide poisoning CO , the CO oximeter will detect this Hb and will report the oxyhemoglobin saturation as markedly reduced. Measurement Traditionally, this measurement is made from Arterial blood gas arterial blood processed in a blood gas analyzer with a CO oximeter. ref name pmid455674 cite journal author Rodkey FL, Hill TA, Pitts LL, Robertson RF title Spectrophotometric measurement of carboxyhemoglobin and methemoglobin in blood journal Clinical Chemistry volume 25 issue 8 pages 1388 93 year 1979 month August pmid 455674 doi url http www.clinchem.org cgi pmidlookup?view long&pmid 455674 accessdate 2009 07 17 ref ref name pmid7361284 cite journal author Rees PJ, Chilvers C, Clark TJ title Evaluation of methods used to estimate inhaled dose of carbon monoxide journal Thorax volume 35 issue 1 pages 47 51 year 1980 month January pmid 7361284 pmc 471219 doi 10.1136 thx.35.1.47 url http thorax.bmj.com cgi pmidlookup?view long&pmid 7361284 accessdate 2009 07 17 ref More recently, pulse CO oximeters have made it possible to estimate carboxyhemoglobin with non invasive technology similar to a Pulse oximeter ref name pmid18500075 cite journal author Coulange M, Barthelemy A, Hug F, Thierry AL, De Haro L title Reliability of new pulse CO oximeter in victims of carbon monoxide poisoning journal Undersea & Hyperbaric Medicine volume 35 issue 2 pages 107 11 year 2008 pmid 18500075 doi url http archive.rubicon foundation.org 8084 accessdate 2009 07 17 ref ... more details
of nitrate than others. The cytochrome b5 reductase methemoglobin reductase enzyme may ... ehp dw Programs nitrate.htm ref Such individuals cannot break down methemoglobin as rapidly as those that do have the enzyme, leading to increased circulating levels of methemoglobin the implication ... more details
Image Streptococcal hemolysis.jpg thumb Hemolyses of Streptococcus spp. BR left &alpha hemolysis S. mitis BR middle &beta hemolysis S. pyogenes BR right &gamma hemolysis non hemolytic, S. salivarius Hemolysis Haemolysis in British English is the breakdown of red blood cells . The ability of bacterial colonies to induce hemolysis when grown on blood agar is used to classify certain microorganisms . This is particularly useful in classifying Streptococcus streptococcal species. A substance that causes hemolysis is a hemolysin . Types of hemolysis Alpha When Alpha hemolysis hemolysis is present the agar under the colonies is dark and greenish. Streptococcus pneumoniae and a group of oral streptococci Streptococcus viridans Streptococcus viridans or viridans streptococci display alpha hemolysis. This is sometimes called green hemolysis because of the color change in the agar. Other synonymous terms are incomplete hemolysis and partial hemolysis . Alpha hemolysis is caused by hydrogen peroxide produced by the bacterium, oxidizing hemoglobin to green methemoglobin . Beta Beta hemolysis hemolysis , sometimes called complete hemolysis , is a complete lysis of red cells in the media around and under the colonies the area appears lightened yellow and transparent. Streptolysin, an exotoxin, is the enzyme produced by the bacteria which causes the complete lysis of red blood cells. There are two types of streptolysin Streptolysin O SLO and streptolysis S SLS . Streptolysin O is an oxygen sensitive cytotoxin, secreted by most Group A streptococcus GAS , and interacts with cholesterol in the membrane of eukaryotic cells mainly red and white blood cells, macrophages, and platelets , and usually results in hemolysis under the surface of blood agar. Streptolysin S is an oxygen stable cytotoxin also produced by most GAS strains which results in clearing on the surface of blood agar. SLS affects immune cells, including polymorphonuclear leukocytes and lymphocytes, and is thought ... more details
for membrane ion pumps and NADH for reduction of methemoglobin . The PPP supplies the red blood cell ... to methemoglobin that also weakens the cell wall. Glutathione removes peroxides via the action ... more details
Massi Joe E. Kiani born February 22, 1965 is an Iran ian born United States American entrepreneur who co founded medical technology company Masimo in 1989 with fellow engineer Mohammed Diab. ref http www.ocbj.com news 2006 mar 20 masimos kiani stared down tyco ref The company is now publicly traded and employs approximately 2,000 people worldwide. ref http www.anesthesiologynews.com ancp 0810 content ANCP10 046a.html?pagename Masimo Corporation Corporate Profile ref Image Joe Kiani 2.jpg thumbnail Masimo Chairman and CEO Joe Kiani Joe Kiani was born in Shiraz , Iran and emigrated to the United States at the age of nine. ref http wn.com masimo ceo joe kiani part 1 ref He received both his bachelor s B.S.E.E and master s M.S.E.E degrees in electrical engineering from San Diego State University . ref http www.allbusiness.com north america united states california metro areas 4072648 1.html ref Masimo makes a pulse oximetry technology known as Masimo Signal Extraction Technology SET ref http www.anesthesia analgesia.org content 95 4 967.long ref as well as Rainbow SET Pulse CO Oximetry, which non invasively and continuously measures parameters that previously required invasive procedures, such as total hemoglobin SpHb , carboxyhemoglobin SpCO , methemoglobin SpMet , and pleth variability index PVI . ref http www.medicalnewstoday.com articles 107498.php ref Masimo also makes Rainbow Acoustic Monitoring, wihch provides Respiration Rate RRa . ref http www.rtmagazine.com news 2009 12 01 01.asp ref Under Kiani s leadership, Masimo won a patent infringement award when it sued the Nellcor division of Tyco Healthcare now known as Covidien for infringing on its patents for measure through motion and low perfusion pulse oximetry. Masimo was awarded more than 300 million in damages when the suit was settled in 2006. ref http www.knobbe.com prac iplitigation masimo.htm ref In addition, Kiani and Masimo filed a 2004 lawsuit against Tyco claiming it violated antitrust laws specifical ... more details
in sickle cell disease by increasing methemoglobin levels ref name Beutler E 1871 Beutler E. The effect of methemoglobin formation in sickle cell disease. J Clin Invest 40 1856 1871, 1961 ref , carboxyhemoglobin ... more details
PBB geneid 1727 NADH cytochrome b5 reductase 3 is an enzyme that in humans is encoded by the CYB5R3 gene . ref name pmid2479590 cite journal author Tomatsu S, Kobayashi Y, Fukumaki Y, Yubisui T, Orii T, Sakaki Y title The organization and the complete nucleotide sequence of the human NADH cytochrome b5 reductase gene journal Gene volume 80 issue 2 pages 353 61 year 1989 month Dec pmid 2479590 pmc doi 10.1016 0378 1119 89 90299 0 ref ref name pmid3268037 cite journal author Bull PC, Shephard EA, Povey S, Santisteban I, Phillips IR title Cloning and chromosomal mapping of human cytochrome b5 reductase DIA1 journal Ann Hum Genet volume 52 issue Pt 4 pages 263 8 year 1989 month Nov pmid 3268037 pmc doi 10.1111 j.1469 1809.1988.tb01105.x ref The PBB Summary template is automatically maintained by Protein Box Bot. See Template PBB Controls to Stop updates. PBB Summary section title summary text Two forms of NADH cytochrome b5 reductase are known, a membrane bound form in somatic cells anchored in the endoplasmic reticulum, mitochondrial and other membranes and a soluble form in erythrocytes. The former exists mainly on the cytoplasmic side of the endoplasmic reticulum and functions in desaturation and elongation of fatty acids, in cholesterol biosynthesis, and in drug metabolism. The erythrocyte form is located in a soluble fraction of circulating erythrocytes and is involved in methemoglobin reduction. The membrane bound form has both membrane binding and catalytic domains. The soluble form has only the catalytic domain. This gene encodes both forms of the enzyme which arise from tissue specific alternative transcripts that differ in the first exon. Mutations in this gene cause methemoglobinemias. ref name entrez cite web title Entrez Gene CYB5R3 cytochrome b5 reductase 3 url http www.ncbi.nlm.nih.gov sites entrez?Db gene&Cmd ShowDetailView&TermToSearch 1727 accessdate ref References reflist Further reading refbegin 2 PBB Further reading citations cite journal author Nar ... more details
methemoglobin Fe sup 3 sup cannot bind oxygen. ref cite journal author Linberg R, Conover CD, Shum KL, Shorr RG title Hemoglobin based oxygen carriers how much methemoglobin is too much .... In such cases, the enzyme cytochrome b5 reductase methemoglobin reductase will be able to eventually reactivate methemoglobin by reducing the iron center. In adult humans, the most common hemoglobin ... oxidation state III as methemoglobin , when not accompanied by superoxide . O sub 2 sub sup sup to hold ... or methemoglobin pronounced MET hemoglobin , which cannot bind oxygen. Hemoglobin in normal red ... of converting a small fraction of hemoglobin to methemoglobin in red blood cells. The latter reaction ... more details
Refimprove date November 2007 An arterial blood gas ABG is a blood test that is performed using blood from an artery . It involves puncturing an artery with a thin needle and syringe and drawing a small volume of blood. The most common puncture site is the radial artery at the wrist , but sometimes the femoral artery in the groin or other sites are used. The blood can also be drawn from an arterial catheter . The test is used to determine the pH of the blood, the partial pressure of carbon dioxide and oxygen , and the bicarbonate level. Many blood gas analyzers will also report concentrations of lactate , hemoglobin , several electrolyte s, oxyhemoglobin , carboxyhemoglobin and methemoglobin . ABG testing is mainly used in pulmonology , to determine gas exchange levels in the blood related to lung function, but has a variety of applications in other areas of medicine. Combinations of disorders can be complex and difficult to interpret, so calculators, ref name ABG interpreter cite web author Baillie K title Arterial Blood Gas Interpreter url http www.prognosis.org arterial blood gas calculator.php publisher prognosis.org accessdate 2007 07 05 Online arterial blood gas analysis ref nomograms , and rules of thumb ref cite journal author Baillie JK title Simple, easily memorised rules of thumb for the rapid assessment of physiological compensation for acid base disorders journal Thorax volume 63 issue 3 pages 289 90 year 2008 pmid 18308967 doi 10.1136 thx.2007.091223 ref are commonly used. Extraction and analysis Arterial blood for blood gas analysis is usually extracted by a phlebotomist , nurse , or respiratory therapist . ref cite journal author Aaron SD, Vandemheen KL, Naftel SA, Lewis MJ, Rodger MA title Topical tetracaine prior to arterial puncture a randomized, placebo controlled clinical trial journal Respir Med. volume 97 issue 11 pages 1195 1199 year 2003 pmid 14635973 doi 10.1016 S0954 6111 03 00226 9 ref Blood is most commonly drawn from the radial artery b ... more details
. This method has the advantage of avoiding the formation of methemoglobin see below . This antidote ... for cyanide. The nitrite s oxidize hemoglobin to methemoglobin which competes with cytochrome oxidase ... more details
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