Disease relevance of MB

• RESULTS: Three patients were diagnosed to have suffered from perioperative myocardial infarction on the basis of significant elevations of troponin T and creatine kinase MB-isoenzyme (CK-MB) concentrations [1].
• In conclusion, a dissociation in the adaptive response of m. erector spinae in scoliosis between mitochondrial enzyme and myoglobin content was demonstrated [2].
• The enzyme activities of creatine kinase (CK), its isoenzyme MB (CK-MB) and of lactate dehydrogenase isoenzyme 1 (LD-1) have been used for years in diagnosing patients with chest pain in order to differentiate patients with acute myocardial infarction (AMI) from non-AMI patients [3].
• The present study investigated the net myocardial release of SA and the cardiac markers (cTnT, Mb, CK-MB) during reperfusion after hypothermic cardioplegic cardiac arrest in 25 patients undergoing elective CABG [4].
• Overexpressions of myoglobin and antioxidant enzymes in ragged-red fibers of skeletal muscle from patients with mitochondrial encephalomyopathy [5].

Psychiatry related information on MB

• The combination of myoglobin and physician decision making identified 63 of the 65 patients (96.9% [95% CI = 92.7 to 100]) with subsequent AEs [6].
• In a time study we compared the analytical and clinical performance of the Tandem Icon QSR CK-MB enzyme-immunoassay (Hybritech) (creatine kinase-MB) and a creatine kinase-MB immunoinhibition method (Boehringer Mannheim GmbH) (creatine kinase-B) [7].
• There was a close correlation between serum levels of CK and Mb with physical activity [8].
• Myoglobin concentrations > 5 nmol/L (83 micrograms/L) were measurable with response times of 15 to 130 min limited by diffusion into the sensing element [9].
• Size estimation of acute myocardial infarction from serial serum myoglobin observations with due consideration of individual differences in basic kinetics [10].

High impact information on MB

• Studies of ET reactions in ruthenium-modified proteins have probed lambda and HAB in several metalloproteins (cytochrome c, myoglobin, azurin) [11].
• Comparison of serum enzyme activities in the remaining 374 patients confirmed that Hp 2-2 patients had significantly higher total creatine kinase, creatine kinase isoenzyme MB fraction, aspartate aminotransferase, and lactate dehydrogenase peak levels [12].
• During a 72-hour fast, serum creatine phosphokinase rose more than 10 times, and myoglobin was detected in urine [13].
• Myoglobin is a globular haem protein that reversibly binds ligands such as O2 and CO [14].
• Comparison with the CO-bound and unligated myoglobin structures reveals that on photodissociation of the CO, the haem 'domes', the iron moves partially out of the haem plane, the iron-proximal histidine bonds is compressed, the F helix is strained and the distal histidine swings towards the outside of the ligand-binding pocket [14].

Chemical compound and disease context of MB

• METHODS: We measured myoglobin, carbonic anhydrase III and creatine kinase MB-fraction release serially in 29 patients with acute myocardial infarction treated with thrombolysis and in 28 patients treated with primary coronary angioplasty [15].
• RESULTS: Myocardial activities of citrate synthase as well as contents of coenzyme Q10 and myoglobin in patients with ischaemic heart disease were not different from those of the reference group, and no linear relation was found between these three markers on the one hand and thallium uptake on the other [16].
• Michellamine B (MB) is a naturally occurring naphthylisoquinoline alkaloid of novel chemical structure with activity against human immunodeficiency virus (HIV) types 1 and 2 in vitro [17].
• We investigated the release of MB and CK in 40 patients who underwent ILP for melanoma (n = 15) or sarcoma (n = 25) using rhTNF alpha/melphalan (n = 28) or a triple-drug regimen (n = 12) [18].
• Acute myocardial infarction in chest pain patients with nondiagnostic ECGs: serial CK-MB sampling in the emergency department. The Emergency Medicine Cardiac Research Group [19].

Biological context of MB

• Myoglobin, muscle fibre diameter, and citrate synthase activity were measured in leg muscle of untrained and trained men and in the myocardium from the apex of the left ventricle and from papillary muscle in patients subjected to open heart surgery [20].
• Myoglobin content and activities of CS and ASAT were not related to left ventricular function [21].
• A sequence motif (CCAC box) within an upstream enhancer region of the human myoglobin gene is essential for transcriptional activity in both cardiac and skeletal muscle [22].
• Unique sequence DNA probes were isolated from the cloned gene and used to test for the presence of the human myoglobin gene in a series of human rodent somatic cell hybrids containing various complements of human chromosomes [23].
• Somatic cell hybrids containing translocation chromosomes carrying part of chromosome 22 were used to locate the myoglobin gene to the region 22q11----22q13 [23].

Anatomical context of MB

• The claudication leg had higher activities of a marker enzyme for mitochondrial oxidative capacity, citrate synthase (CS), as well as of the MB and the mitochondrial isoenzyme of creatine kinase (CK), which are considered to be involved in the transfer of high energy phosphate from the mitochondria to the resynthesis of ATP in the cytoplasm [24].
• The myoglobin content in trained skeletal muscle did not differ from that of untrained muscle [20].
• Myoglobin content in human skeletal muscle and myocardium: relation to fibre size and oxidative capacity [20].
• In the left ventricle it was only 40% of that found in untrained muscle while papillary muscle had almost twice as high a myoglobin content as did the left ventricle [20].
• OBJECTIVE: The purpose of the present study was to evaluate the usefulness of the myoglobin/carboanhydrase III (Myo/CAIII) ratio in the diagnosis of perioperative myocardial infarction during coronary artery bypass surgery [1].

Associations of MB with chemical compounds

• An enhancement solution dissociates Eu3+ and Sm3+ ions from the labeled CA III and Mb, respectively, into a solution where they form highly fluorescent chelates [25].
• No significant differences between claudication and healthy leg were found in distribution of muscle fibre types or fibre dimension, capillary density or myoglobin content, nor was there any side difference in phosphofructokinase or lactate dehydrogenase [24].
• Mean plasma/serum ratios for cTnT (0.95), creatine kinase-MB (1.01) and myoglobin (0.99) were comparable with those of the 29 common analytes (interval of means 0.83-1.05) [26].
• Here we show that human ferrous oxy-myoglobin (oxyMb) oxidizes .NO, with a second order rate constant k = 2.8 +/- 0.1 x 10(7) M(-1).s(-1) as determined by stopped-flow spectroscopy [27].
• Mass spectrometry of wild-type human Mb following reaction with H(2)O(2) demonstrated the formation of a homodimer (mass of 34,107 +/- 5 atomic mass units) sensitive to reducing conditions [28].

Physical interactions of MB

• Fluorescence measurements gave no indication of NADPH binding to deoxygenated ferrous or ferric myoglobin [29].
• Using pluramycin as a probe, it was determined that TBP binding to the human myoglobin TATA sequences enhances pluramycin reactivity at a site immediately downstream of the TATA box [30].
• However, all strains were able to utilize the heme from myoglobin when myoglobin was complexed with haptoglobin [31].
• Earlier markers such as myoglobin and heart fatty acid binding protein (hFABP) may provide information earlier; however, the true role of such markers remains unclear when applied to real life patient cohorts [32].
• The sequence of heme decomposition by the reconstituted heme oxygenase system is quite similar to that in the non-enzymic coupled oxidation of myoglobin and ascorbic acid [33].

Enzymatic interactions of MB

• Recent studies suggest that NO* can serve as an antioxidant of the highly oxidizing ferryl myoglobin (MbFe(IV)=O), which has been proposed to be at least in part responsible for the oxidative damage caused by the reperfusion of ischemic tissues [34].

Regulatory relationships of MB

• The two biphasic mesotheliomas which expressed desmin also expressed smooth muscle actin but were negative for myoglobin [35].
• Antioxidant effect of coenzyme Q on hydrogen peroxide-activated myoglobin [36].
• The myoglobin/H2O2/system activated phenothiazines that were scarcely active or inactivate with the MPO/H2O2/system, such as the trifluoromethyl derivatives [37].

Other interactions of MB

• Good correlations were obtained with the results of CA III RIA and a commercial myoglobin RIA kit [25].
• In addition, the bedside tests for cTnT and cTnI alone or together with myoglobin and CK-MB mass can be used instead of quantitative analyses in the diagnosis of patients with chest pain [3].
• In patients with CPEO/KSS, stainings of Mb, SOD, CAT, and GSH-Px in nonatrophic ragged-red fibers (RRFs) were more intense than those in non-RRFs [5].
• The myoglobin gene is therefore not linked to the alpha-globin gene cluster on chromosome 16 or the beta-globin cluster on chromosome 11, and represents a third dispersed globin locus in the human genome [23].
• In specimens from patients with DMD/PM, the antioxidant enzymes but not Mb were overexpressed in degenerative fibers [5].

Analytical, diagnostic and therapeutic context of MB

• Citrate synthase, ASAT, CK, CK-MB, CK-MIT and LD activities were decreased (12-30%) after the postoperative leg immobilization period [38].
• Dual-label time-resolved fluoroimmunoassay for simultaneous detection of myoglobin and carbonic anhydrase III in serum [25].
• Myoglobin, creatine kinase MB isoforms and creatine kinase MB mass in early diagnosis of myocardial infarction in patients with acute chest pain [39].
• RESULTS: Thrombolytic therapy was followed by a 9.1+/-2.2-fold increase in myoglobin and 10.8+/-3.3-fold increase in creatine kinase MB-fraction during the first hour of treatment, while carbonic anhydrase III remained unchanged [15].
• BACKGROUND: The serum ratio of heart-type fatty acid-binding protein to myoglobin (F/M) has been shown to be a new marker for cardiac damage and volume overload in hemodialysis patients [40].

References