Determination of creatine kinase MB activity with the Du Pont aca: interferences from the sample matrix.

1984 ◽  
Vol 30 (2) ◽  
pp. 238-242 ◽  
Author(s):  
W Stein ◽  
J Bohner

Abstract During the last three years we and other have observed discrepancies between results for creatine kinase isoenzyme MB as measured with the mechanized ion-exchange chromatographic method in the Du Pont aca and those by other techniques. These observations prompted us to investigate the influence of the matrix on the Du Pont CK-MB assay. We conclude that, apart from possible interferences by CK-MM, CK-BB, and both types of macro CK, the aca will give apparent CK-MB activities that are directly related to protein concentration and inversely related to sodium chloride concentration. Practical consequences for the routine and emergency laboratories are: no diluted samples are allowed; application is restricted to samples from patients suspected of acute myocardial infarction which show upper-normal total CK activity; and multiple timed samples are run, in order to recognize the typical change in enzyme pattern with time.

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.


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.


1983 ◽  
Vol 29 (6) ◽  
pp. 1115-1119 ◽  
Author(s):  
H F ter Welle ◽  
T Baartscheer ◽  
J W Fiolet

Abstract In determination of creatine kinase isoenzyme MB (CK-MB), the Boehringer immunoinhibition method gives a high and variable blank activity as compared with column-chromatography. Thus a correction must be applied. Furthermore, a second correction of 1% of total creatine kinase activity is necessary to compensate for nonspecific creatine phosphate-dependent activity. As a consequence, two immunoinhibition determinations--one for CK-MB and one for blank activity--and a determination of total creatine kinase are required. Use of the manufacturer's diagnostic criteria, on the basis of which suspected myocardial infarction is confirmed or eliminated, leads to a high frequency of false-negative conclusions.


1964 ◽  
Vol 19 (2) ◽  
pp. 292-296 ◽  
Author(s):  
Irene R. Held ◽  
Smith Freeman

The binding of calcium to human plasma albumin, alpha, beta, and gamma globulins was studied with the aid of an ultracentrifuge. The amount of calcium bound to these separated proteins was determined in solutions with electrolyte concentrations and pH within physiological ranges. The total calcium concentration was 2.35–2.90 mm/liter H2O and the total protein concentration was 3.91–4.29 g/100 ml H2O. In these solutions no significant differences were found for the binding of calcium (expressed as mm Ca++ bound per gram protein) by albumin, alpha, and beta globulins; the average values obtained were, respectively, 0.016, 0.018, and 0.023. Significantly less calcium was bound by gamma globulin; 0.009 mm/gram. The pH was varied between 7.200–7.550 and the sodium chloride concentration between 114–157 mEq Na per liter. These changes did not measurably affect the amount of calcium bound to albumin. protein-bound calcium; ultracentrifugation and determination of protein-bound calcium; plasma globulin-bound calcium; plasma albumin-bound calcium Submitted on July 2, 1963


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).


1988 ◽  
Vol 34 (10) ◽  
pp. 2031-2038 ◽  
Author(s):  
R A Rudolph ◽  
L H Bernstein ◽  
J Babb

Abstract We show how to make an unsupervised discrimination of disease and nondisease states by measuring information and using newer notions of inductive reason. We also present a new theory of group-based reference values that is based on measuring information uncertainty. We use data on the isoenzymes creatine kinase-MB (CK-MB) and lactate dehydrogenase-1 (LD1) and on the percentage of LD1 from 101 patients with acute myocardial infarction (AMI) and from 41 patients with suspected, but unfounded, infarction (non-AMI). Calculating the Shannon entropy, a concept from information theory, of the data base allows determination of a difference in entropy values ("effective information"), which determines decision cutoff values that produce binary-base patterns yielding the fewest classification errors. Redundancy in testing is important because it provides the information to approach a goal of errorless discrimination by coding the test results and meeting the conditions of the "Noisy Channel Theorem" of information theory. This redundancy improves the predictive value of diagnosis by isolating the area of equivocation to evident patterns. Results for CK-MB and LD1 are 99% correct in assigning cases to AMI and non-AMI categories; adding %LD1 increases the proportion of errorless binary patterns from 25% to 90%.


1991 ◽  
Vol 122 (4) ◽  
pp. 958-964 ◽  
Author(s):  
David Wolfson ◽  
Eric Lindberg ◽  
Lyndon Su ◽  
Sergio J. Farber ◽  
Stuart B. Dubin

Author(s):  
J. Spincemaille ◽  
J. Delanghe ◽  
M. De Buyzere ◽  
M. Breemeersch ◽  
V. Blaton

1982 ◽  
Vol 28 (8) ◽  
pp. 1796-1796
Author(s):  
Steven D Stroop ◽  
Gerard Helinek ◽  
Harry L Greene

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.


Sign in / Sign up

Export Citation Format

Share Document