Creatine Kinase B-subunit Activity Research Articles

Creatine kinase B-subunit activity in serum in cases of suspected myocardial infarction: a prediction model based on the slope of MB increase and percentage CK-MB activity.

Journal Article Creatine kinase B-subunit activity in serum in cases of suspected myocardial infarction: a prediction model based on the slope of MB increase and percentage CK-MB activity. Get access L H Bernstein, L H Bernstein Search for other works by this author on: Oxford Academic Google Scholar G Reynoso G Reynoso Search for other works by this author on: Oxford Academic Google Scholar Clinical Chemistry, Volume 29, Issue 3, 1 March 1983, Pages 590–592, https://doi.org/10.1093/clinchem/29.3.590a Published: 01 March 1983

Electrophysiologic study for ventricular arrhythmia: Effect on total and myocardial-specific creatine kinase activity

To determine the potential for myocardial injury during electrophysiologic study for ventricular arrhythmia, total creatine kinase and creatine klnase B-subunit enzyme activity were serially measured after the procedure in 24 patients. During electrophysiologic study 14 of the 24 patients had sustained ventricular tachycardia or fibrillation, 4 patients had nonsustained ventricular tachycardia, and 6 patients had no ventricular arrhythmia induced. Cardioversion was necessary because of hemodynamic collapse in 9 of the 14 patients with sustained ventricular tachycardia or ventricular fibrillation. Coronary heart disease was present in 14 of the 24 patients, in 9 of the 14 with sustained ventricular tachycardia or ventricular fibrillation, and in 7 of the 9 patients requiring cardioversion. Total creatine kinase was modestly elevated (greater than twice baseline or greater than normal, or both) 24 hours after electrophysiologic study in 10 (42%) of the patients. Electrophysiologic study with or without the induction of ventricular tachycardia or ventricular fibrillation was not associated with Increased creatine kinase B-subunit activity even in patients with coronary heart disease.

More SensitiveFlamelessAtomicAbsorptionAnalysisof Vanadiumin Tissueand Serum

Abstract Vol. 28 p 79: See response in Letter of Cornelisand Versieck, p 1709. p 91: In the note added in proof, "131" should read "1.31." p 241: In Table 1, "6.5" should read "65"; in the footnote to Table 2, "0.05" should read "0.5" and the next to last paragraph should read: "Finally, in a few instances we have compared the glucose values obtained by using a drop of sample according to the instructions, versus dipping the strips into the sample, and found some variance between the values obtained by the two methods." p 344: Under "staining reagent," the correct concentration of orthophosphoric acid is 160 g/L (not 80 g/L). It is prepared by diluting 95 mL of the concentrated acid (850 g/kg, relative density 1.69 g/mL) to 1 L with distilled water. p 418: ref. 94, cited in the first full paragraph, should read "84." p 419: The volume number of ref. 1 should be 50, not 19. p 502: Corrections to two equations: the term (S2y - S2x) should read (S2y - S2x)2 and in the third equation in the second column delete the repetition of the term "(wx4)," which should only appear once. p 531: In last full paragraph in column one, the word "propionate" in the next to last line should instead read "dimethyl sulfoxide." p 614: References 21 and 22 are missing 21: Gerhardt, W., Ljungdahl, L., Borjesson, J., et al., Creatine kinase B-subunit activity in human serum. I. Development of an iminunoinhibition method for routine determination of S-creatine kinase B-subunit activity. Clin. Chim. Acta78, 29-41 (1977). 22: Neumeier, D., Prellwitz, W., Wurzburg, U., et al., Determination of creatine kinase isoenzyme MB activity in serum using immunological inhibition of creatine kinase M subunit activity: Activity kinetics and diagnostic significance in myocardial infarction. Clin. Chim. Acta73, 445-451 (1976). p 727: With regard to this Letter, the authors later pointed out that although the first sentence states that glycosylated hemoglobins have a higher isoelectric point, glycosylation actually decreases the isoelectric point. Later (p 728) they speculated that the fast hemoglobin variant might be HbN-Baltimore (α2β295Lys→Glu), but two reference laboratories identified it as the slightly slower HbJ-Baltimore (α2β216Gly→Asp). p 735: In the middle column, the third full paragraph, "Department of Internal Medicine" should read "Department of Laboratory Medicine." p 736: In column one, under Awards, the citation should have stated "in recognition of his contribution in the, field of clinical chemistry." p 1199: Table 1 folate concentrations should be "mg/L," not rg/L.

Significance of serum myoglobin in neuromuscular diseases and in carrier detection of Duchenne muscular dystrophy.

In a retrospective study, the serum myoglobin concentration (S-myoglobin) was determined in patients with neuromuscular diseases and in carriers of Duchenne muscular dystrophy (DMD). Myoglobin was quantified by a sensitive radioimmunoassay. Serum creatine kinase (CK, EC 2.7.3.2) activity (S-CK) and serum creatine kinase B-subunit activity (S-CKB) were determined for comparison. Sera from 70 patients with various neuromuscular diseases and from 17 female relatives of patients with DMD were analysed. Increased levels of S-myoglobin were found both in dystrophic and in spinal myopathies. Because of a marked overlap of the range of values between the different dystrophic myopathies and even between the dystrophic and the spinal myopathies, S-myoglobin is of little value in the final diagnosis of neuromuscular diseases. In the detection of carriers of DMD, simultaneous determination of S-myoglobin and S-CK gave a higher detection rate compared to the detection rate with S-CK. S-CKB was normal in all carriers and only elevated in some of the patients with DMD and limb girdle muscular dystrophy.

Optimized bioluminescence assay of creatine kinase and creatine kinase B-subunit activity.

Spectrophotometry of CK-B subunit activity based on immunoinhibition is rapid and convenient. However, the low sensitivity limits clinical applications to serum samples with CK-B activities considerably above normal. A sensitive, but not optimized, bioluminescent assay of CK-B, also based on immunoinhibition, has been described. We improved this method by the use of an ADP concentration saturating the CK reaction and by the combined use of AMP and diadenosine pentaphosphate for inhibition of adenylate kinase. The optimized bioluminescent method is similar to the corresponding spectrophotometric method (reaction conditions, analytical procedure, numerical results, etc.) and results by the two methods correlate well. However, the measuring time is shorter and, more important, the sensitivity of the bioluminescent method allows accurate determinations of CK-B, even in serum from healthy individuals (CV approximately 3%). Kits and instrumentation (manual and automatic) for determination of CK and CK-B are now commercially available.

Creatine kinase and creatine kinase B-subunit activity in serum in cases of suspected myocardial infarction.

We evaluated a diagnostic strategy by studying 481 patients suspected of having had an acute myocardial infarction; the prevalence of infarction by independent criteria was 0.43. This strategy is based on the sequential application of: (a) clinical criteria; (b) total creatine kinase determinations in two serum samples drawn within 10 to 20 h of the onset of acute symptoms; and (c) creatine kinase B-subunit (S-CK B) determinations after immunoinhibition with antibodies to creatine kinase M-subunit in the reaction medium in all samples found to have increased total creatine kinase activity. Discrimination limits of 150 U/L total creatine kinase for women and 200 U/L for men gave a diagnostic sensitivity of 0.99. Activities less than these limits in samples identified 68% of the 274 non-infarct cases (posterior probability of a negative result of 0.99) within 20 h. Subsequent determination of S-CK B in 292 patients who were positive by the discrimination limits for total creatine kinase verified myocardial infarction in 99% of 207 cases for which S-CK B exceeded the discrimination limit of 12 U/L. The strategy excluded 98% of all non-infarct cases at a posterior probability of 0.99.

Creatine kinase B-subunit activity in human sera: temporal aspects of its sensitivity after myocardial infarction.

We assessed the changes in sensitivity and specificity of creatine kinase (CK) isoenzymes at various times after acute myocardial infarction. CK-B was measured by an immunoinhibition technique. CK-MB was measured both by column chromatography on Sephadex DEAE A-50 and by electrophoresis on agarose gel. For CK-B, the sensitivity in detecting infarct varied from 11% in the first 8 h after onset of symptoms to 80% at 32 h after the infarct. Sensitivities for CK-MB by column and by electrophoresis were 25 and 45% for the first 8-h period and 80 and 89% at the 32nd hour, respectively. Comparison of values for CK-B with values for CK-MB by column and by electrophoresis gave correlation coefficients of 0.935 and 0.896, respectively. Patients having macro CK-BB exhibit anomalously high values for CK-B with respect to total CK. Patients having a mild infarct may show no increase in CK-isoenzymes.

Detection of acute myocardial infarction by a new, sensitive and rapid method for determination of creatine kinase B-subunit activity.

An immunoinhibition method for the assay of creatine kinase (CK) isoenzymes by continuous monitoring of the ATP formation in the CK reaction by a purified firefly luciferase reagent has been developed. The sensitivity of the firefly assay of ATP makes it possible to assay CK-B subunit activity (CK-B) in serum down to 1 U/l. In healthy individuals CK-B varied between 2 and 12, mean 3 U/l. A wide range of CK-B activity was observed after acute myocardial infarction (AMI), intramuscular injection and surgery with overlapping between these different categories. Therefore the maximal change in CK-B activity (ΔCK-B) was studied in 98 patients admitted to a coronary care unit. In all 57 patients without a subsequent diagnosis of AMI according to conventional criteria ΔCK-B was < 5 U/l. In all 41 patients with AMI ΔCK-B was ≥ 5 U/l. In all healthy individuals ΔCK-B was < 2 U/l. ΔCK-B ≥ 5 U/l was found after i.m. injection and different kinds of surgery in three out of 60 patients. Thus, the present method for determination of CK activity has been shown to possess high precision in low activities, to be as rapid as conventional methods and to be simple enough to be used in a routine laboratory. With these properties the method should be suited for early diagnosis and early exclusion of even very small AMIs.

Bioluminescence ATP monitoring as a method for the determination of total creatine kinase and creatine kinase B-subunit activity in human serum

Bioluminescence ATP monitoring as a method for the determination of total creatine kinase and creatine kinase B-subunit activity in human serum

Creatine kinase B-subunit activity in serum: Three years experience with M-subunit immunoinhibitors and routine application to the diagnosis of acute myocardial infarction (AMI)

Creatine kinase B-subunit activity in serum: Three years experience with M-subunit immunoinhibitors and routine application to the diagnosis of acute myocardial infarction (AMI)

Evaluation of serum creatine kinase B-subunit activity determination in the diagnosis of acute myocardial infarction

Serum CK-MB and LD-I have proved extremely useful in the diagnosis and differential diagnosis of acute myocardial infarction. However, CK-MB is present in skeletal muscle and can be released during ischemic attacks; thus, abnormal serum CK-MB activities cannot be equated with myocardial injury. Even wider is the distribution of LD-1, which is found particularly in erythrocytes and renal cortex; hence, an abnormal LD-1 level also cannot be equated with myocardial injury.The method of choice and the final arbiter for the CK and LD isoenzymes is electrophoresis. The possibility of interpreting the results visually fulfills, in part, quality-control needs, and makes the technique suitable for small and large laboratories. Extreme analytic sensitivity is not needed, and electrophoresis provides clinically useful and acceptable results.

Creatine kinase B-subunit activity in serum after immunoinhibition of M-subunit activity.

Creatine kinase (EC 2.7.3.2) B-subunit activity in serum may be routinely measured as residual activity after specific immunoinhibition of the M-subunit. We assessed the inhibition kinetics, specificity, completeness of inhibition, and inhibitory capacity of three different anti-M preparations, with use of isolated human BB, MM, and MB isoenzymes. The Scandinavian-recommended reaction system was used. We suggest a set of tentative quality requirements for anti-M for use in diagnosing acute myocardial infarction. The need to measure and subtract sample residual adenylate kinase activity was demosntrated. We describe a routine photometric method for determining B-subunit activity in serum. With the Scandinavian CK method the upper reference value for total creatine kinase in serum was found to be 150 U/L for women, 270 U/L for men. By bioluminescence, we found the upper reference value for B-subunit activity to be 6 U/L for both sexes. We discuss three different modes for applying B-subunit determinations to the diagnosis of acute myocardial infarction.

Creatine kinase B-subunit activity in human serum. II. Evaluation of S-CK B-subunit activity in the diagnosis of acute myocardial infarction

In a group of 113 consecutive patients taken into a coronary care unit on suspicion of acute myocardial infarction, blood samples were taken every 6 h and the following enzyme activities were measured: creatine kinase (S-CK), aspartate aminotransferase (S-ASAT), alanine aminotransferase (S-ALAT) and lactate dehydrogenase (S-LD). All measurements were made according to the Recommendations of the Scandinavian Committee on Enzymes. On all patients S-CK B subunit activity was determined by immunoinhibition with a specific anti CK M-subunit inhibitory antibody. At peak values of the respective total enzyme activities CK and LD isoenzymes were further qualitatively estimated by electrophoresis. The data indicate that even serial determinations of total CK, ASAT, ALAT and LD activities in serum do not provide the information required for a conclusive diagnosis of myocardial infarction in the individual case. In contrast, the positive predictive value (PV) of S-CK B was found to be 1.0 and the negative predictive value was 0.98. S-CK MB showed a PV pos. of 1.0 and also a PV neg. of 1.0. Electrophoretic determination of S-LD iso-enzymes was slightly poorer with a PV pos. of 0.96 and PV neg. of 0.98. S-CK, total activity with nearly 9 per cent false positives had a positive predictive value of only 0.91, but a negative one of 1.0.

Creatine kinase B-subunit activity in human serum. I. Development of an immunoinhibition method for routine determination of S-creatine kinase B-sununit activity

The properties of an inhibiting antibody directed against the M-subunits of human creatine kinase (EC 2.7.3.2, CK) were investigated in the reaction system recommended by the Scandinavian Committee on Enzymes (S.C.E.). At 37° C the rate of immunoinhibition of human CK M-subunit dependent activity corresponded to a t 1 2 of 38 s giving a k value of −2 per cent · s −1 when samples were incubated in the S.K.E. CK reagent A in the presence of antibody. Under the selected conditions immunoinhibition of S-CK M-subunit activity up to 1800 U/l was 99 per cent completed within 5 minutes using undiluted samples. No inhibition of CK B-subunit activity occurred at the chosen concentration of antibody. The inhibition data were verified using human sera and electrophoretically homogeneous preparations of human CK isoenzymes BB and MM. Sample adenylate kinase (EC 2.7.4.3, AK) was found to constitute a potential source of falsely increased S-CK B activity. As reported in the accompanying paper a S-CK B value of 15 U/l was used as a discrimination value in the diagnosis of acute myocardial infarction. The S.C.E. CK method incorporates a combination of two AK inhibitors adenosine 5'-monophosphate and P 1, P 5-diadenosine 5'-pentaphosphate. However, a frequency analysis of sample AK activities demonstrated that AK activities of more than 8 U/l will occur in about 10 per cent of the cases. Consequently, it was deemed necessary to measure the individual sample blank AK rates. The routine procedure developed thus included three separate measurements: determination of total S-CK and of S-CK B activities in the absence and presence of antibody, respectively. As the immunoinhibition was only 99 per cent complete a value corresponding to one per cent of the total S-CK activity was subtracted from the measured S-CK B activity. Likewise, the individual sample AK activity had to be measured and subtracted from the apparent S-CK B activity. The within-series precision of this S-CK B method at the levels of 10 U/l and 20 U/l corresponded to C.V. values of 10 and 5 per cent, respectively. Day-to-day precision at the level of 417 U/l corresponded to a C.V. of 4 per cent. The day-to-day precision of a control, total CK activity 625 U/l, gave a mean value of 53% ± 3% of CK B activity.