Stability and electrophoretic characteristics of creatine kinase BB extracted from human brain and intestine.

1988 ◽  
Vol 34 (3) ◽  
pp. 489-492 ◽  
Author(s):  
S L Chastain ◽  
C H Ketchum ◽  
W E Grizzle

Abstract Creatine kinase (CK; EC 2.7.3.2) isoenzyme BB extracted from brains of rats reportedly undergoes modification at 37 degrees C, leaving an electrophoretic variant that accounts for most of the residual CK activity. This variant, called CK-BB', migrates on electrophoresis similarly to creatine kinase isoenzyme MB. Using electrophoresis and immunoinhibition with antiserum to creatine kinase isoenzyme MM, we found CK-BB to be the only identifiable cytoplasmic isoenzyme in surgical samples from human brain and intestine. In contrast, we found that some samples of brain obtained at autopsy contain CK-BB'. We also found that CK-BB extracted from human brain was converted to CK-BB' upon incubation in serum or plasma at 37 degrees C. We found a similar development of CK-BB' in incubation mixtures of serum or plasma containing CK-BB obtained from surgical samples of human intestine. The development of CK-BB' during infarction of the gastrointestinal system may thus be a source of false-positive CK-MB in the laboratory verification of myocardial infarction when electrophoresis is used as the only method to identify CK isoenzymes.

1978 ◽  
Vol 24 (10) ◽  
pp. 1818-1821 ◽  
Author(s):  
L M Shaw ◽  
D A Newman

Abstract Six of 13 randomly selected patients in a medical intensive-care unit with above-normal creatine kinase MB activities had diagnoses other than myocardial infarction. These data, which indicate the need for further study, were obtained during evaluation of a commercially available column procedure (Biodynamics/bmc).


1980 ◽  
Vol 26 (1) ◽  
pp. 150-152
Author(s):  
D Obzansky ◽  
J A Lott

Abstract We have clinically evaluated the Dade "Cardiozyme" immunoinhibition procedure for determination of creatine kinase isoenzyme MB (CK-MG) in 71 patients who were suspected of having had an acute myocardial infarction. Electrophoresis for CK-MB was also carried out. On the basis of diagnostic sensitivity and specificity for myocardial infarction, we found the Dade procedure for CK-MB to be somewhat inferior to electrophoresis. In 11 patients for whom the time of infarction was known, we observed normal CK-MB results for two of them by both immunoinhibition and electrophoresis during the first 24 h, but subsequently could detect abnormal CK-MB results by both methods. Thus in some patients such data are not helpful for making a diagnosis in the first 24 h. The Dade procedure is easy to perform, but lacks sensitivity in the region of low CK-MB activity, requires a very stable spectrophotometer, is imprecise, and produces negative numerical results in patients without myocardial infarction.


1989 ◽  
Vol 35 (3) ◽  
pp. 444-447 ◽  
Author(s):  
L H Bernstein ◽  
I J Good ◽  
G I Holtzman ◽  
M L Deaton ◽  
J Babb

Abstract By using bivariate probability estimation for the diagnosis of acute myocardial infarction (AMI) we show how to overcome the difficulties encountered for patients whose clinical presentation is atypical and those encountered when multiple isoenzyme determinations are treated by univariate methods. We use the values for creatine kinase isoenzyme MB measured at the time of admission and 12 h later to estimate the Bayes factors in favor of AMI. The Bayes factors are compiled into a table that the clinician can use to estimate the posterior probability that a patient has AMI. The table of Bayes factors is based on data for a sample of 802 non-AMI patients and 180 AMI patients. Further to validate the method, we randomly chose 200 of the non-AMI and 50 of the AMI patients as an evaluation sample, then used the remaining 602 non-AMI and 130 AMI patients to recompute the Bayes factors. These Bayes factors were used to find the probability of AMI for each of the 250 patients in the evaluation sample. The method resulted in only one false positive and no false negatives. For the misclassified patient the measurements at admission and 12 h later were 1 and 11 U/L; the posterior odds were 15 to 1 in favor of AMI, but in fact the patient was non-AMI.


1985 ◽  
Vol 31 (10) ◽  
pp. 1741-1742 ◽  
Author(s):  
R H Ng ◽  
C Roe ◽  
D Funt ◽  
B E Statland

Abstract A 78-year-old woman had increased activities of creatine kinase (CK; EC 2.7.3.2) and CK-MB isoenzyme in her serum, associated with severe theophylline intoxication. The time course for CK-MB activity was similar to that from an acute myocardial infarction. Clinical findings, however, including electrocardiograms, did not support the diagnosis of myocardial infarction. We suggest caution in interpreting CK-MB results in severe theophylline intoxication.


1981 ◽  
Vol 27 (6) ◽  
pp. 828-831 ◽  
Author(s):  
T C Kwong ◽  
R L Rothbard ◽  
T L Biddle

Abstract A new radiometric assay specific for creatine kinase isoenzyme MB was evaluated with respect to its precision and agreement with a conventional electrophoretic CK-MB assay for the diagnosis of myocardial infarction. The reference interval we find for serum CK-MB in healthy subjects is 0--30 micrograms/L. The coefficients of variation at 197 and 40 micrograms of CK-MB per liter, were 5.2 and 11.5%, respectively. In a clinical study of 52 consecutive patients admitted into a Coronary Care Unit with a diagnosis of suspected myocardial infarction, there was overall agreement in CK-MB results by the two assays for 51 of 52 patients. A more sensitive and quantitative assay that is specific for CK-MB can be helpful in cases where diagnosis of myocardial infarction is equivocal.


1990 ◽  
Vol 36 (4) ◽  
pp. 639-641 ◽  
Author(s):  
A Usui ◽  
K Kato ◽  
H Sasa ◽  
K Minaguchi ◽  
T Abe ◽  
...  

Abstract Concentrations in serum of S100ao protein (alpha alpha form of S-100 protein, which is present at high concentrations in heart muscle) were successively measured by enzyme immunoassay in 21 patients with acute myocardial infarction (AMI) and six with angina pectoris (ANP). Results were compared with measurements of creatine kinase isoenzyme MB (CK-MB) concentrations in the same specimens. Mean S100ao concentrations in sera from 100 healthy adults were 0.12 (SD 0.08) microgram/L. In patients with AMI, S100ao concentrations were 4.74 +/- 5.27 micrograms/L at admission, peaked 8 h after admission (23.5 +/- 27.7 micrograms/L), then decreased gradually. Among nine AMI patients who were admitted within an hour after their attack, eight showed abnormally high concentrations of S100ao in serum (greater than 0.5 microgram/L), whereas only four showed abnormally high CK-MB concentrations (greater than 5 micrograms/L) in sera at the time of admission. Serum S100ao concentrations remained within the normal range in all six patients with ANP; however, serum CK-MB concentrations were increased in two of them. Therefore, serum S100ao is useful not only for detection of AMI but also for differentiating AMI from ANP.


1980 ◽  
Vol 26 (1) ◽  
pp. 150-152 ◽  
Author(s):  
D Obzansky ◽  
J A Lott

Abstract We have clinically evaluated the Dade "Cardiozyme" immunoinhibition procedure for determination of creatine kinase isoenzyme MB (CK-MG) in 71 patients who were suspected of having had an acute myocardial infarction. Electrophoresis for CK-MB was also carried out. On the basis of diagnostic sensitivity and specificity for myocardial infarction, we found the Dade procedure for CK-MB to be somewhat inferior to electrophoresis. In 11 patients for whom the time of infarction was known, we observed normal CK-MB results for two of them by both immunoinhibition and electrophoresis during the first 24 h, but subsequently could detect abnormal CK-MB results by both methods. Thus in some patients such data are not helpful for making a diagnosis in the first 24 h. The Dade procedure is easy to perform, but lacks sensitivity in the region of low CK-MB activity, requires a very stable spectrophotometer, is imprecise, and produces negative numerical results in patients without myocardial infarction.


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