Cardiac myoglobin detection

Cardiac myoglobin detection was based on direct electron transfer between the Fe(III)-heme and the electrode surface that was modified with metal nanoparticles stabilized by didodecyldimethylammonium bromide and antibodies. Gold, silver, and copper nanoparticles were tested as catalysts of the Fe(III)/Fe(II) electrode process. Experiments were carried out with human blood plasma samples of healthy donors and patients with acute myocardial infarction. The method proposed does not require labeled secondary antibodies. The myoglobin immunosensor has a detection limit of 5 ngrnL and a broad range of working concentrations (Suprun et al., 2011). The whole procedure takes 20 min and can be used to establish the diagnosis of acute myocardial infarction. 

Suprun, E.V., Shilovskaya, A.L., Lisitsa, A.V., Buiko, T.V., Shumyantseva, V.V., Archakor, A.I., 2011. Electrochemical immunosensor based on metal nanoparticles for cardiac myoglobin detection in human blood plasma. Electroanalysis 23 (5), 1051—1057. 

Elevations in cTnl and cTnT are highly specific for myocardial injury. However, in individuals without myocardial disease, their levels are very low to undetectable. This is in contrast to the low but measurable concentrations of CK-2 and myoglobin detected in serum from skeletal muscle turnover in patients with noncardiac-related diseases and in normal individuals. Therefore release of cTnl or cTnT from myocardium into the blood following AMI and after the washout that accompanies successful reperfusion generates an excellent signal compared with no detectable baseline levels before myocardial damage. The initial rapid release of cardiac troponin subunits I and T following successful reperfusion is most hkely derived from the soluble cytosolic myocardial fraction (6% cTnT 3% cTnl). 

These equations are applicable to ferryl myoglobin radical production in chemical systems, but the results are less clear when applied to cellular systems such as cardiac myocytes. A better spectroscopic approach here is to observe the shifts in the Soret region to detect qualitatively the presence of ferryl myoglobin (Turner et al., 1991). Fig. 4.6 shows the comparison between the visible spectra of metmyoglobin... 

Apple PS, Christenson RH, Valdes R, Wu AHB, Andriak AJ, Duh SH et al. Simultaneous rapid measurement of whole blood myoglobin, creatine kinase MB, and cardiac troponin I by the Triage Cardiac Panel for detection of myocardial infarction. Clin Chem 1999 273 1279-82. 

Apple FS, Voss E, Lund L, Preese L, Berger CR, Henry TD. Cardiac troponin, CK-2, and myoglobin for the early detection of acute myocardial infarction and... 

Diagnosis of cardiac muscle injury relies on the detection of biomarkers such as troponin I (Tnl), troponin C (TnC), myoglobin, fatty acid binding protein (FABP), glycogen phosporylase isoenzyeme BB (GPBB), C-reactive protein (CP), urinary albumin, creatine kinase myocardial band (CK-MB), and brain (B-type) natriuretic peptide in blood and urine [28-30]. 

In the acute setting of cocaine-induced chest pain, assessment includes the possible diagnosis of acute myocardial infarction. However, cocaine may independently affect cardiac biomarkers [22 ]. Recent cocaine use may alter the specificity of measurement of serum creatine kinase and its MB Iraction. Among cocaine users, increased serum creatine kinase activities and increased mean myoglobin concentrations are common. Increased skeletal muscle activity and rhab-domyolysis are often present, possibly because of cocaine-induced hyperthermia. Troponin I concentrations are more reliable cardiac biomarkers for detecting cocaine-induced myocardial infarction and are associated with a poor prognosis. 

Zhu JM, et al. Simultaneous detection of high-sensitivity cardiac troponin I and myoglobin by modified sandwich lateral flow immunoassay proof of principle. Clinical Chemistry 2011 57 1732-8. http //dx.doi.org/10.1373/clinchem.2011.171694. 

FIGURE 9.39 The change in ET resistance as a function of the concentration of cTnl (A) or a nonspecific control myoglobin ( ). (Reprinted with permissions from Periyakaruppan, A., Gandhiraman, R.P., Meyyappan, M. et ah, Label-free detection of cardiac troponin-I nsing carbon nanofiber based nanoelectrode arrays, Anal. Chem., 85, 3858-3863. Copyright 2013, American Chemical Society.)... 

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