Mass concentration of creatine kinase MB isoenzyme and lactate dehydrogenase isoenzyme 1 in diagnosis of perioperative myocardial infarction after coronary bypass surgery

Recent advances in methodology allow the mass concentration of creatine kinase MB isoenzyme (CK-MB), and of lactate dehydrogenase isoenzyme 1 (LD1) to be determined quickly and easily as routine, emergency tests. We evaluated these tests as diagnostic criteria of perioperative myocardial infarction (PMI) after coronary bypass surgery. These tests were compared with the usual measurements of CK-MB activity by immunoinhibition and LD1 by electrophoresis and with other biological markers of myocardial infarction such as total CK, total LD, and aspartate aminotransferase. Sixty-one patients who underwent coronary bypass grafting were followed pre- and postoperatively by enzyme determinations and electrocardiography; a subgroup was monitored by myocardial scintigraphy. CK-MB mass appeared to be the best marker of PMI during the first 48 h, although LD1 was the marker of choice from days 2 to 4.     

Increased serum lactate dehydrogenase isoenzyme 1 and macro creatine kinase type 2 in a patient with lung cancer

A 72-yr-old man, having a lung tumor with metastatic spread to liver and bone, was hospitalized with a lactate dehydrogenase (LD; EC 1.1.1.27) activity and a creatine kinase (CK; EC 2.7.3.2) activity in serum of 30 and 2 times the upper reference limit (URL), respectively. The LD isoenzyme-1/LD activity ratio was 62% (2 times URL). This ratio was maintained throughout hospitalization, during which LD activity increased up to 90 times URL. Macro CK type 2 activity represented almost all of the CK activity, which increased up to 4 times URL during hospitalization. The patient died the 29th day after admission. The enzyme abnormalities were thought to stem from tumor tissue.     

Abnormal lactate dehydrogenase isoenzyme pattern in a critically ill patient

We have described a patient who had an abnormal isoenzyme of lactate dehydrogenase in both serum and tissue. The presence of LD6 is indicative of a poor prognosis. Some of the biochemical characteristics of the isoenzyme are (1) LD6 is not an artifact, (2) it contains an M subunit but not an H subunit, and (3) it is not an immunoglobulin complex. We believe LD6 may arise during episodes of severe shock as lysosomes rupture and is either a previously sequestered lysosomal LD or is a lysosomal modification of LD5.     

Serum creatine kinase isoenzyme MB concentration after endomyocardial biopsy

Serum total creatine kinase (CK), CK-MB and myoglobin (Mb) were serially determined in 17 patients who underwent endomyocardial biopsy. Mean total CK levels increased from 36 +/- 27 U/l 30 min before biopsy to a maximum of 112 +/- 77 U/l 8 h following the procedure (p less than 0.05). Similarly, Mb concentrations rose from 57 +/- 55 micrograms/l to 119 +/- 57 micrograms/l 30 min after biopsy (p less than 0.05). Normalization of total CK and Mb levels occurred within 16 and 8 h, respectively. A new immunoenzymetric assay (IEMA) was used to measure the mass concentration of the CK-MB molecule. The initial CK-MB levels were 0.2 +/- 0.4 microgram/l; a small but significant elevation was recorded as early as 2 h after biopsy (1.6 +/- 1.5 micrograms/l, p less than 0.05). CK-MB returned to initial concentration 16 h after the beginning of the procedure. Comparison with the maximum CK-MB levels recorded in 16 myocardial infarction patients (258 +/- 172 micrograms/l, range 90-680 micrograms/l) indicated that the modest increase of CK-MB level detected after biopsy probably reflects a limited endomyocardium lesion at the sampling site, excluding any significant myocardial damage. Total CK and Mb, which showed more pronounced elevations than CK-MB, are likely to originate from other sources than the myocardium.     

Serum creatine kinase isoenzyme BB is a poor index to the size of various brain lesions

We divided patients with brain lesions into three groups: (a) patients with primary or metastatic brain cancer, (b) brain infarctions, and (c) brain contusion(s). We analyzed each patient's sera for creatine kinase isoenzyme BB (CK-BB), using a monoclonal antibody kit (Impres-BB; International Immunoassay Laboratories). Computerized axial tomography (CAT) scans were performed on each patient. The size of the various lesions was measured from the CAT scan and recorded in milliliters. Total CK, CK-BB, and their ratios were compared with the volume of damaged brain tissue. We found no correlation between any of the variables and the various brain lesions. We attribute this lack of correlation to an intact blood-brain barrier, the rapid elimination or inactivation of CK-BB, or some combination of these factors.     

Effect of isoenzyme composition on Kodak Ektachem test results for creatine kinase, lactate dehydrogenase, alkaline phosphatase, and amylase.

Seventy-four patients' sera containing macroenzymes or other uncommon enzyme forms were analyzed for total creatine kinase, lactate dehydrogenase, alkaline phosphatase, or amylase activity on an Ektachem 700XR analyzer. The Ektachem test results correlated well with activities obtained by means of liquid reagents on RA-1000. For each enzyme tested, linear-regression analysis yielded data comparable with those for sera containing exclusively the more common isoenzymes. Increased concentrations of intestinal ALP, however, resulted in higher activities of total ALP being reported for the Ektachem.     

Creatine kinase activity and isoenzyme pattern in various normal tissues and neoplasms

I measured total creatine kinase (CK; EC 2.7.3.2) activity and isoenzyme pattern in normal and neoplastic tissues. CK activity was detected in all of them examined. In various tumors it was greater than, less than, or the same as that in normal tissue, no clear correlation being seen between total activity and growth rate or degree of differentiation. In several cases, there was a greater proportion of the CK-MM isoenzyme, and 15 of 53 cases showed an atypical CK-MM band. The atypical CK-MM band, also reported by others, might be an insensitive and nonspecific tumor marker. The CK-BB isoenzyme, ubiquitous in neoplastic tissues, might accordingly be a nonspecific marker. Total CK activity was very low in most tumor tissues. Presumably a bulky tumor or an advanced stage of malignancy is a requisite to release of routinely detectable CK-BB into the circulation.     

不同补液温度对失血性休克兔二胺氧化酶和心肌酶变化的影响

目的 探讨失血性休克时适宜的抗休克补液温度。方法 将23只家兔按随机方法分为假手术 组(n=7)、液体复苏温热组(n=8)、常温组(n=7)和低温组(n=8)。温热组、常温组、低温组兔复制失血性休克 模型后,给予3倍失血量的平衡液及自体血复苏,液体温度分别控制在(39.5±1.3)℃、(20.6±1.3)℃和 (10.7±1.6)℃。选择休克前、休克模型成功后30 min及液体复苏后1、2和4 h 5个时间点取血,观察二胺氧 化酶(DAO)和心肌酶的变化。结果 温热溶液复苏DAO升高幅度较低;温热溶液复苏使肌酸激酶、肌酸激酶 同工酶和乳酸脱氢酶上升幅度较小。结论 温热液体治疗失血性休克对改善肠黏膜和心肌细胞缺血性损伤, 维持肠黏膜完整性有一定意义。     

Serum creatine kinase and CK-MB isoenzyme responses to acute and prolonged swimming in trained athletes

Six highly-trained male swimmers completed a maximum work capacity tethered swim and a 1-h continuous tethered swim at approximately 70% VO2max in order to evaluate total serum creatine kinase and CK-MB isoenzyme changes. Venous blood obtained before, 5 min post-, 6 h post-, and 24 h post-exercise was analyzed for total serum CK (kinetic UV method, normal = less than 100 U/l) and CK-MB isoenzyme (quantitative electrophoretic technique, normal = less than 5 U/l). VO2max averaged 4.59 +/- 0.28 l/min, with a mean total work time of 24.5 min to achieve maximum capacity. Mean resting total CK was 100.5 +/- 15.8 U/l. Compared to rest, neither swim bout produced a significant (p greater than 0.05) elevation in mean total creatine kinase. No CK-MB isoenzyme was observed in any post-exercise blood sample. Swimming, performed by highly-trained swimmers at high levels of intensity or for prolonged durations, may not impose sufficient degrees of trauma producing muscular stress. Therefore, the structural integrity of the cell membrane is maintained and the loss of intracellular creatine kinase to the bloodstream prevented.     

Simultaneous separation of creatine kinase and lactate dehydrogenase isoenzymes using an electrophoresis method]

A specific and sensitive rapid method for simultaneous electrophoretic separation of the blood serum creatine kinase (CK) and lactate dehydrogenase (LDH) isoenzymes is described, fit for rapid diagnosis. A common electrophoresis scheme was used for the separation of both enzymes on the same cellulose acetate plate. Then the isoenzymes were separately detected by their enzymic activities. To detect the enzymic activities at the sites of isoenzymes' localization, the samples were incubated with substrate gel. Optimal conditions for the detection of CK and LDH activities were defined. To illustrate the diagnostic value of the method, the blood serum CK and LDH isoenzymic activities were measured in the patients with acute myocardial infarction and in those operated on for aortocoronary shunting.