... (British: methaemoglobin) (pronounced "met-hemoglobin") is a hemoglobin in the form of metalloprotein, in which ... Methemoglobin is expressed as a concentration or a percentage. Percentage of methemoglobin is calculated by dividing the ... The NADH-dependent enzyme methemoglobin reductase (a type of diaphorase) is responsible for converting methemoglobin back to ... For example, a methemoglobin concentration of 1.5 g/dL may represent a percentage of 10% in an otherwise healthy patient with a ...
He determined that the iron centre in methemoglobin is a ferric (FeIII) centre, unlike the ferrous (FeII) centre found in ... Conant, J. B.; Fieser, L. F. (1925). "Methemoglobin". Journal of Biological Chemistry. 62 (3): 595-622. doi:10.1016/S0021-9258( ... Bodansky, O. (1951). "Methemoglobinemia And Methemoglobin-Producing Compounds". Pharmacological Reviews. 3 (2): 144-191. ISSN ...
When methemoglobin concentration is elevated in red blood cells, tissue hypoxia may occur. Normally, methemoglobin levels are ... Due to a deficiency of the enzyme diaphorase I (cytochrome b5 reductase), methemoglobin levels rise and the blood of met-Hb ... The binding of oxygen to methemoglobin results in an increased affinity for oxygen in the remaining heme sites that are in ... People with severe methemoglobinemia (methemoglobin level above 50%) may exhibit seizures, coma, and death (level above 70%). ...
It works by generating methemoglobin. This is suitable as an emergency treatment only; treatment must be followed up with ... Vick JA, Von Bredow JD (1996). "Effectiveness of intramuscularly administered cyanide antidotes on methemoglobin formation and ...
It converts hemoglobin into methemoglobin. 2,4-Dinitrotoluene is also a listed hazardous waste under 40 CFR 261.24. Its United ...
"Spectrophotometric measurement of carboxyhemoglobin and methemoglobin in blood". Clinical Chemistry. 25 (8): 1388-93. doi: ...
It can act as an oxidant, to induce the formation of methemoglobin. Methemoglobin in turn can sequester cyanide as ... Therefore, the measurement of actual ratios and levels of methemoglobin and hemoglobin must accompany any blood gas partial ... More fundamentally, blood gas analysis on the whole has limited effectiveness, as the increased methemoglobin level increases ... forming methemoglobin, which cannot carry oxygen. Severe poisoning cases will progress to methemoglobinemia, characterized by a ...
The nitrites were administered to produce methemoglobin and induce vasodilation. Amyl nitrites were discontinued in 2012 in ... therapeutic methemoglobin levels'". The American Journal of Emergency Medicine. 7 (4): 437-440. doi:10.1016/0735-6757(89)90057- ...
Methemoglobinemia, which is a disease defined by high levels of methemoglobin in the blood. Increased levels of methemoglobin ... Additionally, a direct methemoglobin level can be obtained. As of 22 May 2007, the United States Environmental Protection ... A CO-oximeter can be used to detect levels of methemoglobin in the blood if methemoglobinemia is suspected, by seeing the ... This is possible because methylene blue oxidizes NADPH, which in turn can convert methemoglobin back to hemoglobin. Out of all ...
... and methemoglobin (MetHb). The use of 'CO' rather than 'Co' or 'co' is more appropriate since this designation represents a ... carboxyhemoglobin and methemoglobin. Crit Care International, April-May, 8-9, 1995. Moran RF, The case for standardized ... methemoglobin -metHb, other hemoglobin moieties and 'background' light-absorbing species. Traditionally, measurement is made ... "Spectrophotometric measurement of carboxyhemoglobin and methemoglobin in blood". Clinical Chemistry. 25 (8): 1388-93. doi: ...
Nitrosotoluene converts hemoglobin to methemoglobin, resulting in methemoglobinemia.[ISBN missing] Evidence suggests that this ... increased methemoglobin levels and moderate skin irritation and severe eye irritation in rabbits. Only oral short-term exposure ... Observed symptoms included increased methemoglobin levels, congestion, hemosiderosis (iron overload disorder), hematopoiesis ( ...
Fierro, B. R., Agnew, D. W., Duncan, A. E., Lehner, A. F., & Scott, M. A. (2013). Skunk musk causes methemoglobin and Heinz ...
In such cases, the enzyme methemoglobin reductase will be able to eventually reactivate methemoglobin by reducing the iron ... The iron ion may be either in the ferrous Fe2+ or in the ferric Fe3+ state, but ferrihemoglobin (methemoglobin) (Fe3+) cannot ... Nitric oxide is capable of converting a small fraction of hemoglobin to methemoglobin in red blood cells. The latter reaction ... Linberg R, Conover CD, Shum KL, Shorr RG (1998). "Hemoglobin based oxygen carriers: how much methemoglobin is too much?". Artif ...
Gibson, Q. H. (1948). "The reduction of methaemoglobin in red blood cells and studies on the cause of idiopathic ... Gibson, Q. H. (1943). "The reduction of methaemoglobin by ascorbic acid". Biochemical Journal. 37 (5): 615-618. doi:10.1042/ ...
A hemichrome (FeIII) is a form of low-spin methemoglobin (metHb). Hemichromes, which precede the denaturation processes of ... to methemoglobin (met-Hb) and ending up in hemichrome (HC). For forensic purposes, the fractions of HbO2, met-Hb and HC in a ...
Pisciotta, A. V.; Ebbe, S. N.; Hinz, J. E. (July 1959). "Clinical and laboratory features of two variants of methemoglobin M ... and elevated methemoglobin (metHb) level in blood. HbM is an altered form of hemoglobin (Hb) due to point mutation occurring in ... "Interpreting sulfhemoglobin and methemoglobin in patients with cyanosis: An overview of patients with M-hemoglobin variants". ... HbM is a rare methemoglobin group inherited in an autosomal dominant manner, resulting from missense mutations in genes ...
Cyanide has a preference to the ferric ion on methemoglobin over the ferric ion on cytochrome oxidase a3 and causes cyanide to ... The nitrites act with hemoglobin to form methemoglobin which binds cyanide. ...
... is believed to work by creating methemoglobin that then binds with cyanide and thus removes it from the ... The patient's levels of methemoglobin should be regularly checked during treatment. While not well studied during pregnancy, ...
Myocardial oxygen-supply during hemodilution with stroma-free hemoglobin and methemoglobin solutions. Biro GP, Beresford- ...
"Nitrates in drinking water and methemoglobin levels in pregnancy: a longitudinal study". Environmental Health. 9 (1): 60. doi: ...
Hydroxylamine can also generate methemoglobin, a protein that could hinder further oxygen exchange. It was also detected that ...
... methemoglobin is reduced back to hemoglobin. When large amounts of methemoglobin occur secondary to toxins, methemoglobin ... which then reduces the heme group from methemoglobin to hemoglobin. Methylene blue can reduce the half life of methemoglobin ... Specifically, it is used to treat methemoglobin levels that are greater than 30% or in which there are symptoms despite oxygen ... Normally, through the NADH- or NADPH-dependent methemoglobin reductase enzymes, ...
This method has the advantage of avoiding the formation of methemoglobin (see below). This antidote kit is sold under the brand ... The nitrites oxidize hemoglobin to methemoglobin, which competes with cytochrome oxidase for the cyanide ion. Cyanmethemoglobin ...
2007 Davenport, H (1952). "A natural factor catalyzing reduction of methaemoglobin by isolated chloroplasts". Proc R Soc Lond B ... Noted for research in photosynthesis, his early career involved the methaemoglobin reducing factor, later known as ferredoxin. ... "A natural factor catalyzing reduction of methaemoglobin by isolated chloroplasts" in Proceedings of the Royal Society B: ...
Nitrite ions then combine with hemoglobin to produce methemoglobin, blocking the transport of oxygen. The result is a form of ...
The methylene blue allows the methaemoglobin to be converted to haemoglobin. Supportive treatment is also usually provided, ...
He determined methemoglobin's absorption spectra and was the first to crystallize several derivatives of hemoglobin. He was ...
T2*-weighted sequences are used to detect deoxygenated hemoglobin, methemoglobin, or hemosiderin in lesions and tissues. ...
Yubisui T, Takeshita M, Yoneyama Y (June 1980). "Reduction of methemoglobin through flavin at the physiological concentration ... flavin reductase often catalyzes an NADPH dependent reduction of flavin mononucleotide which occurs in methemoglobin in ... the body and are used in a variety of processes which include metabolism of fat and ketones and the reduction of methemoglobin ...
If the heme is oxidized, methemoglobin, which is more brownish and cannot transport oxygen, is formed. In the rare condition ...