Cardiac troponin-I is not expressed in fetal and healthy or diseased adult human skeletal muscle tissue

1995 ◽  
Vol 41 (12) ◽  
pp. 1710-1715 ◽  
Author(s):  
G S Bodor ◽  
D Porterfield ◽  
E M Voss ◽  
S Smith ◽  
F S Apple

Abstract Cardiac troponin-I (cTnI) is not found in sera of patients with skeletal muscle disease in the absence of myocardial injury. It is not known, however, whether trace amounts of cTnI are expressed in regenerating human skeletal muscle, as has been observed with creatine kinase MB. Using immunohistochemical and biochemical techniques, we investigated cTnI expression in various human muscle tissues: human heart tissue (n = 5), normal adult skeletal muscle (n = 3), and fetal heart (n = 3) and skeletal muscle (n = 3) obtained, respectively, during heart transplant, from autopsy, or from a tissue bank. Specimens from diagnostic tissue biopsies were used as diseased skeletal muscle: polymyositis (PM), n = 13; Duchenne muscular dystrophy (DMD), n = 6. Frozen sections 8 microns thick were stained immunohistochemically for either cTnI or TnI (cardiac or skeletal) by using monoclonal antibodies (MAb) 2B1.9 (cTnI specific) or 3C5.10 (reactive with all TnI isoforms), respectively. cTnI was measured in tissue homogenates by an immunofluorometric assay. Cardiac muscle was stained by both MAbs. Normal fetal and adult skeletal muscle, and samples from all of the PM and DMD patients, stained only with the nonspecific MAb (3C5.10), confirming the sole presence of skeletal TnI. No cTnI was detectable by immunoassay in any skeletal muscle sample. We conclude that cTnI is not expressed in human skeletal muscle during development or during regenerative muscle disease processes such as PM or DMD.

1975 ◽  
Vol 149 (3) ◽  
pp. 525-533 ◽  
Author(s):  
H A Cole ◽  
S V Perry

1. Troponin I isolated from fresh cardiac muscle by affinity chromatography contains about 1.9 mol of covalently bound phosphate/mol. Similar preparations of white-skeletal-muscle troponin I contain about 0.5 mol of phosphate/mol. 2. A 3':5'-cyclic AMP-dependent protein kinase and a protein phosphatase are associated with troponin isolated from cardiac muscle. 3. Bovine cardiac 3':5'-cyclic AMP-dependent protein kinase catalyses the phosphorylation of cardiac troponin I 30 times faster than white-skeletal-muscle troponin I. 4. Troponin I is the only component of cardiac troponin phosphorylated at a significant rate by the endogenous or a bovine cardiac 3':5'-cyclic AMP-dependent protein kinase. 5. Phosphorylase kinase catalyses the phosphorylation of cardiac troponin I at similar or slightly faster rates than white-skeletal-muscle troponin I. 6. Troponin C inhibits the phosphorylation of cardiac and skeletal troponin I catalysed by phosphorylase kinase and the phosphorylation of white skeletal troponin I catalysed by 3':5'-cyclic AMP-dependent protein kinase; the phosphorylation of cardiac troponin I catalysed by the latter enzyme is not inhibited.


2021 ◽  
pp. 096032712110434
Author(s):  
Yusuf K Tekin ◽  
Gülaçan Tekin ◽  
Naim Nur ◽  
İlhan Korkmaz ◽  
Sefa Yurtbay

Introduction The present study was undertaken to investigate the prognostic value of the frontal QRS-T angle associated with adverse cardiac outcomes in patients with carbon monoxide (CO) poisoning in early stages in the emergency department. Materials and methods The data of 212 patients with CO poisoning who were admitted to the ED between January 2010 and May 2020 were retrospectively analyzed. The frontal QRS-T angle was obtained from the automatic reports of the EKG device. Results Compared to patients without myocardial damage, among patients with myocardial damage, statistically high creatinine, creatine kinase MB, cardiac troponin I, and frontal QRS-T angle values were found ( p < 0.001 for all parameters), while the saturation of arterial blood pH and arterial oxygen values were found to be lower ( p = 0.002 and p < 0.001, respectively). The frontal QRS-T angle values were correlated with creatine kinase, creatine kinase-MB, cardiac troponin I, and oxygen saturation (SpO2) in arterial blood (r = 0. 232, p = 0.001; r = 0. 253, p = < 0.001; r = 0. 389, p = < 0.001; r = −0. 198, p = 0.004, respectively). The optimum cut-off value of the frontal QRS-T angle was found to be 44.5 (area under the curve: 0.901, 95% confidence interval: 0.814–0.988, sensitivity: 87%, specificity: 84%). Conclusions The frontal QRS-T angle, a simple and inexpensive parameter that can be easily obtained from 12-lead surface electrocardiography, can be used as an early indicator in the detection of myocardial damage in patients with CO poisoning.


1999 ◽  
Vol 45 (6) ◽  
pp. 822-828 ◽  
Author(s):  
David J Newman ◽  
Yemi Olabiran ◽  
William D Bedzyk ◽  
Suzette Chance ◽  
Eileen G Gorman ◽  
...  

Abstract Background: Available assays for cardiac troponin I (cTnI) yield numerically different results. The aim of this study was to compare patient values obtained from four cTnI immunoassays. Methods: We studied the Stratus® II assay, the Opus® II assay, the Access® assay, and a research-only cTnI heterogeneous immunoassay that uses the Dade Behring aca® plus immunoassay system equipped with two new noncommercial monoclonal antibodies. Because the aca plus cTnI assay is for research only, we first evaluated and analytically validated it for serum and citrated plasma. Initially, each method was calibrated using the method-specific calibrator supplied by each manufacturer; however, the aca plus cTnI assay was calibrated using patient serum pools containing cTnI and selected on the basis of increased creatine kinase MB isoenzyme and with values assigned by use of the Stratus cTnI assay. For method comparisons, individual patient sample cTnI values were determined and compared with the Stratus II assay. Results: Passing and Bablock regression analysis yielded slopes of 1.44 (r = 0.96; n = 72) for the Opus II vs Stratus II assays; 0.07 (r = 0.91; n = 72) for the Access vs Stratus II assays; and 0.90 (r = 0.91, n = 72) for the aca plus vs Stratus II assays. The recalibration of each method with a Stratus II-assigned serum pool improved, but did not entirely eliminate, the slope differences between the different assays (range, 1.00–1.16). The observed scatter in the correlation curves remained. Conclusion: There is a need to further explore the specificities of these assays with respect to the different circulating forms of cTnI.


1994 ◽  
Vol 40 (7) ◽  
pp. 1291-1295 ◽  
Author(s):  
J E Adams ◽  
K B Schechtman ◽  
Y Landt ◽  
J H Ladenson ◽  
A S Jaffe

Abstract Although measurement of cardiac troponin I (cTnI) is, in some situations, more specific for detection of cardiac injury than is measurement of the MB isoenzyme of creatine kinase (MBCK), its sensitivity and specificity relative to MBCK for detection of myocardial infarction has not been established. Accordingly, we studied prospectively 199 consecutive patients admitted to the coronary care unit. Values of MBCK and cTnI mass were determined in all samples. Of the 188 patients admitted with a suspicion of acute myocardial ischemia, 89 were diagnosed as having an acute myocardial infarction on the basis of the patterns of MBCK values. Eighty-six of these patients also had increased cTnI (concordance, 96.6%); three did not. Of the patients diagnosed as without infarction, five with unstable angina and symptoms in the day(s) prior to admission had increased cTnI, for a cTnI specificity of 94.9%. Receiver operating characteristic curve analysis indicated that cTnI and MBCK had statistically indistinguishable diagnostic accuracies for the detection of acute myocardial infarction.


1997 ◽  
Vol 134 (4) ◽  
pp. 622-630 ◽  
Author(s):  
Milenko J. Tanasijevic ◽  
Christopher P. Cannon ◽  
Donald R. Wybenga ◽  
George A. Fischer ◽  
Christine Grudzien ◽  
...  

2007 ◽  
Vol 8 (1) ◽  
pp. 78 ◽  
Author(s):  
Raffaella Di Lisi ◽  
Anne Picard ◽  
Simonetta Ausoni ◽  
Stefano Schiaffino

1997 ◽  
Vol 4 (1) ◽  
pp. 6-12 ◽  
Author(s):  
Gerard X. Brogan ◽  
Judd E. Hollander ◽  
Charles F. McCuskey ◽  
Henry C. Thode ◽  
Jeffrey Snow ◽  
...  

Author(s):  
Mary McLaurin ◽  
Fred S Apple ◽  
Timothy D Henry ◽  
Scott W Sharkey

Patients with cocaine-related chest pain with electrocardiographic (ECG) abnormalities are often admitted to rule out acute myocardial infarction (AMI). Cardiac troponin I and T should be superior to measurement of creatine kinase (CK)—MB for detecting cardiac injury in patients with coexisting skeletal muscle injury. We prospectively evaluated 19 consecutive patients with acute chest pain related to cocaine use who were hospitalized to rule out AMI. The admission ECG was abnormal in 16 of 19 patients. Total CK and CK—MB were elevated during the hospital course in 14 and 3 patients, respectively. Cardiac troponin I and cardiac troponin T levels were within normal limits in all patients demonstrating that recent myocardial injury did not occur. Clinically, no patient had an AMI. Cocaine-induced thoracic skeletal muscle injury or transient cocaine-induced coronary vasospasm should be considered as alternative sources of chest pain in these patients.


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