Act 10: CK-MB

Question 1

_______ are dimeric molecules composed of M and B subunits and exist as the isoenzymes MM, MB, and BB.

Answer 1

Creatine Kinase

Question 2

Creatine Kinase are dimeric molecules composed of M and B subunits and exist as the isoenzymes (3)

Answer 2

MM, MB, and BB.

Question 3

are distributed primarily in the skeletal muscle and heart muscle, respectively

Answer 3

CK-MM and CK-MB

Question 4

is present mainly in the brain and in tissues composed of smooth muscle.

Answer 4

CKBB

Question 5

Following __________________, CK-MB activity increases significantly and this elevation is highly specific for the laboratory diagnosis of _________________.

Answer 5

acute myocardial infarction; myocardial infarction

Question 6

Although total CK activity usually increases following myocardial infarction, in some patients only the _____ activity increases, while the total CK remains in the normal range.

Answer 6

CK-MB;

Question 7

Conventionally, CK isoenzymes are quantitated after first separating the three species by either (3)

Answer 7

• electrophoresis
• column anion exchange
• batch anion exchange chromatography

Question 8

Recently, ________ have introduced an
immunoinhibition method.

Answer 8

Wurzburg et al.

Question 9

Recently, Wurzburg et al. have introduced an
___________ method.

Answer 9

immunoinhibition

Question 10

Recently, Wurzburg et al. have introduced an
immunoinhibition method. This methodology forms the basis of our?

Answer 10

CK-MB reagent

Question 11

PRINCIPLE of CK-MB

Answer 11

This procedure involves measurement of CK activity in the presence of an antibody to CK-M monomer.

This antibody completely inhibits the activity of CK-MM and half of the activity of CK-MB while not affecting the B subunit activity of CK-MB and CK-BB.

Then we use the CK method to quantitatively determine CK-B activity.

The CK-MB activity is obtained by multiplying the CK-B activity by two.

Question 12

CALCULATIONS:
A) Total CK Activity:
B) CK-B Activity:
C) CK-MB Activity:

Answer 12

A) Total CK Activity: Determine Total CK Activity in serum
B) CK-B Activity: = ΔAbs.min. x 3376
C) CK-MB Activity: CK-MB Activity (UL) = CK-B Activity UL x 2*

Question 13

Millimolar absorptivity of NADH

Answer 13

6.22

Question 14

Total reaction volume in CK-MB

Answer 14

1.050

Question 15

Sample volume in ml in CK-MB

Answer 15

0.050

Question 16

Calculations for Percentage of CK-MB activity in sample:

Answer 16

% CK-MB activity = CK-MB activity x 100/Total CK activity

Question 17

NORMAL VALUES of CK-MB: (37°C)

Answer 17

0-24 IUL

Question 18

NORMAL VALUES of CK-MB: (30°C)*

Answer 18

0-14 IUL

Question 19

NORMAL VALUES of %CK-MB

Answer 19

5.5%

Question 20

To convert CK-MB activity at 37°C to 30°C value, multiply the result by?

Answer 20

0.60