Determination Of Isoenzymes Research Articles

Antibody inhibition procedure for myocardial (CK-MB) isoenzyme determination by a modified program on the Technicon RA-1000 analyzer.

Antibody inhibition procedure for myocardial (CK-MB) isoenzyme determination by a modified program on the Technicon RA-1000 analyzer.

Elevated serum creatine kinase levels. An early diagnostic sign of acute dissection of the aorta.

Twenty-two patients suffering from acute dissection of the aorta were analyzed for their serum creatine kinase levels within six hours of onset of acute chest pain. Elevated serum levels were found in 14 patients (64%). In five patients, creatine kinase isoenzyme analysis was performed. These five patients showed more than 95% creatine phosphokinase MM isoenzyme of the total creatine kinase level. The finding of elevated levels of total creatine kinase in patients presenting with acute chest pain does not exclude acute dissection of the aorta. Determination of creatine kinase isoenzymes may be helpful in the differential diagnosis of acute chest pain.

Value of creatine phosphokinase isoenzyme determinations in the diagnosis of myocardial contusion

Myocardial contusion is an injury often missed in the patient with severe multisystem trauma. Fifty patients with physical findings or mechanisms of injury that were suggestive of possible nonpenetrating injury to the heart were studied with serial creatine phosphokinase isoenzyme (CPK/MB), continuous arrhythmia monitoring, and ECGs for at least 72 hours. Two-dimensional echocardiograms were obtained on all patients within 48 hours of admission. Seventy-two percent (36 of 50) had detectable CPK/MB. Ten patients had echocardiograms suggestive of cardiac contusion. Of these ten, three had no detectable CPK/MB and six had CPK/MB of less than 5%. CPK/MB had a sensitivity of 70% and a specificity of 27.5%. We conclude that in the patient with multisystem injury, CPK/MB determinations are not reliable. The decision to evaluate the patient with echocardiography should be made on the basis of physical findings and, more importantly, on mechanism of injury.

Diagnostic value of serum creatine kinase and lactate dehydrogenase isoenzyme determinations for monitoring early cardiac damage in rats

Serum activities of creatine kinase (CK, EC 2.7.3.2) and CK isoenzymes, lactate dehydrogenase (LDH, EC 1.1.1.27) and LDH isoenzymes, α-hydroxybutyrate dehydrogenase (α-HBDH, no EC) and the LDH/α-HBDH ratio were studied following a single s.c. application of 5–250 mg isoproterenol/kg body weight (b.w.) in rats. Measurements of the serum enzymes and histological and enzyme-histochemical examinations of hearts were performed 2, 4, 6, 8 and 24 h after treatment. A drastic increase in serum levels of the isoenzymes CK-MB, LDH 1, LDH 2 and α-HBDH and decrease in the ratio LDH/α-HBDH were observed from 2 h onwards after isoproterenol application in all dose groups, the maximum effect being after 4–8 h. Focal cellular injury in the myocardium could also be observed from 2 h onwards after isoproterenol application by an enzyme-histochemical method using nitro blue tetrazolium (NBT) whereas the earliest histological alterations using haematoxylin and eosin (HE) stain could be detected 6 h after treatment. A dose-dependent effect as to enzyme values as well as to myocardial necrosis was observed 24 h after isoproterenol application. No kidney damage could be detected on the basis of serum urea nitrogen and histological examinations. Thus, measurement of serum activities of CK-MB isoenzyme alone or LDH 1–2 isoenzymes in combination with other tests to exclude kidney damage are valuable indicators of cardiac lesions in rats.

Does serial determination of lactate dehydrogenase isoenzymes 1 and 2 ratios contribute to the diagnosis of acute myocardial infarction?

Journal Article Does serial determination of lactate dehydrogenase isoenzymes 1 and 2 ratios contribute to the diagnosis of acute myocardial infarction? Get access Z Rotenberg, Z Rotenberg Israel and Ione Massada Center for Heart Diseases, Dept. of Med. A, Petah Tikva, Israel Search for other works by this author on: Oxford Academic Google Scholar I Weinberger, I Weinberger Israel and Ione Massada Center for Heart Diseases, Dept. of Med. A, Petah Tikva, Israel Search for other works by this author on: Oxford Academic Google Scholar E Davidson, E Davidson Israel and Ione Massada Center for Heart Diseases, Dept. of Med. A, Petah Tikva, Israel Search for other works by this author on: Oxford Academic Google Scholar J Fuchs, J Fuchs Israel and Ione Massada Center for Heart Diseases, Dept. of Med. A, Petah Tikva, Israel Search for other works by this author on: Oxford Academic Google Scholar O Sperling, O Sperling Israel and Ione Massada Center for Heart Diseases, Dept. of Med. A, Petah Tikva, Israel Search for other works by this author on: Oxford Academic Google Scholar J Agmon J Agmon Israel and Ione Massada Center for Heart Diseases, Dept. of Med. A, Petah Tikva, Israel Search for other works by this author on: Oxford Academic Google Scholar Clinical Chemistry, Volume 34, Issue 7, 1 July 1988, Pages 1506–1507, https://doi.org/10.1093/clinchem/34.7.1506a Published: 01 July 1988

Emergency surgery in patients with post-traumatic myocardial contusion

Little information concerning the prognostic and functional significance of post-traumatic myocardial contusion appears to exist. During a 10-month period, 19 patients with major blunt thoracic trauma were diagnosed as having myocardial contusion using clinical findings, serial ECG and CPK-MB isoenzyme determinations, and biventricular radionuclide angiocardiography (RA). All patients had associated thoracic and extrathoracic injuries. ECG and RA were useful and complementary tests, detecting abnormalities in 90% and 47% of patients, respectively. Only one patient had an abnormally elevated CPK-MB. All patients required operative treatment for associated injuries, 15 (79%) on the day of admission. Eleven patients required perioperative cardiac inotropic support and one needed IABP. No late complications were attributable to the cardiac contusions per se; no patients died. Emergency surgery for associated injuries in patients with myocardial contusion can be safely performed using hemodynamic monitoring to guide cardiac inotropic support measures. Myocardial contusion does not constitute an absolute contraindication to necessary operations in polytraumatized patients.

Serum CPK and Hypoxic-Ischemic Encephalopathy (HIE)

The value of brain-typical creatine phosphokinase iso-enzyme (CPK-BB) determinations in the assessment of brain damage due to neonatal asphyxia in 33 full-term infants has been assessed in the Services of Neonatology, Child Neurology and Radiology, Clinica Infantil, Cindad Sanitaria “La Paz“, Madrid, Spain.

Emergency Surgery in Patients with Post-traumatic Myocardial Contusion

Little information concerning the prognostic and functional significance of post-traumatic myocardial contusion appears to exist. During a 10-month period, 19 patients with major blunt thoracic trauma were diagnosed as having myocardial contusion using clinical findings, serial ECG and CPK-MB isoenzyme determinations, and biventricular radionuclide angiocardiography (RA). All patients had associated thoracic and extrathoracic injuries. ECG and RA were useful and complementary tests, detecting abnormalities in 90% and 47% of patients, respectively. Only one patient had an abnormally elevated CPK-MB. All patients required operative treatment for associated injuries, 15 (79%) on the day of admission. Eleven patients required perioperative cardiac inotropic support and one needed IABP. No late complications were attributable to the cardiac contusions per se; no patients died. Emergency surgery for associated injuries in patients with myocardial contusion can be safely performed using hemodynamic monitoring to guide cardiac inotropic support measures. Myocardial contusion does not constitute an absolute contraindication to necessary operations in polytraumatized patients.

Early evaluation of cardiac injury by two-dimensional echocardiography in patients suffering blunt chest trauma

The availability of two-dimensional echocardiography as a clinical tool has led to an interest in its applicability, usefulness, and reliability in the evaluation of blunt cardiac trauma. Forty patients who sustained objective evidence of blunt chest trauma were evaluated at our institution using serial ECGs, creatine phosphokinase (CPK) isoenzyme determinations, and two-dimensional echocardiography. Twenty patients (50%) manifested evidence of cardiac injury as demonstrated by abnormal ECGs, elevated CPK isoenzymes, or abnormal echocardiograms. Nine (23%) patients had abnormal echocardiograms with findings of pericardial effusions in four, chamber enlargement in three, and echodense areas of the right ventricle in two. There was no correlation with ECG changes or the presence of CPK isoenzymes. Based on these observations we believe echocardiography can be used as a noninvasive modality to complement other clinical tools in the detection of blunt cardiac injury.

Excretion of urinary N-acetyl-beta-D-glucosaminidase isoenzymes after renal transplantation in the rat.

The urinary excretion of N-acetyl-beta-D-glucosaminidase isoenzymes A and B following kidney transplantation was studied in rats. High enzymuria with permanent marked isoenzyme B excretion occurred from the immediate post-operative period to the irreversible rejection episode. Isoenzyme B could represent as much as 10-40% of total N-acetyl-beta-D-glucosaminidase activity and it reflected the intensity of tubular lesions as observed by histological examination of allograft specimens. Thus, N-acetyl-beta-D-glucosaminidase B isoenzyme determination may reinforce the diagnostic value of total (A + B) urinary N-acetyl-beta-D-glucosaminidase activity determination during the various complications which can occur after transplantation.

Cloning and nucleotide sequence of heavy- and light-chain cDNAs from a creatine-kinase-specific monoclonal antibody.

Determination of creatine kinase isoenzymes by inhibition assay is a useful tool for the diagnosis and monitoring of myocardial infarction. We have established several mouse hybridoma lines secreting monoclonal antibodies with creatine kinase M-subunit inhibitory capacity. One of the monoclonal antibodies (MAK33) inhibits creatine kinase-MM by 80% without influencing the activity of creatine kinase-MB. A combination of two monoclonal antibodies increased the inhibition of creatine kinase MM up to 99.4%. Poly(A) + RNA of hybridoma cells secreting MAK33 was isolated and used for cloning cDNA of both heavy and light chains of this antibody. Full-length cDNA clones were obtained by hybridization with gamma 1 and kappa constant region cDNA probes. The complete nucleotide sequences from the variable regions including signal peptide and part of the 5'-untranslated regions have been determined.

Interference by platelets in the electrophoretic determination of enolase isoenzymes in plasma.

Serum and plasma gave different electrophoretic patterns when enolase isoenzymes were evaluated by electrophoresis on cellulose acetate. Plasma isoenzyme bands were more intense, and there was an additional one (band P) that was not present in serum. We show that, under the conditions of electrophoresis, some of the residual platelets in the plasma are ruptured, releasing intracellular enolases and consequently leading to intensification of the isoenzyme bands. The band P originated from the remaining unruptured platelets. Thus plasma samples must be platelet-free for determination of enolase isoenzyme to be reliable.

4681842 Process and reagent for the differentiated determination of isoenzymes of alkaline phosphatase: Sidney B Rosalki, London, United Kingdom assigned to Boehringer Mannheim GmbH

4681842 Process and reagent for the differentiated determination of isoenzymes of alkaline phosphatase: Sidney B Rosalki, London, United Kingdom assigned to Boehringer Mannheim GmbH

Robotic sample preparation evaluated for the immunochemical determination of cardiac isoenzymes.

A general-purpose bench-top laboratory robot was programmed to perform sample preparation for immunoprecipitative and immunoinhibitory determinations of cardiac isoenzymes with commercial kits. Run size could be varied from 1 to 24 patients' samples, and was determined by the robot without prompting. The robot placed the processed samples into a sample rotor for dried transfer to a batch centrifugal analyzer. Robotic precision compared well with that of manual performance of the same procedures at four concentrations of lactate dehydrogenase (EC 1.1.1.27) isoenzyme 1 activity and at one of two concentrations of creatine kinase (EC 2.7.3.2.) isoenzyme MB activity; for the other creatine kinase MB concentration, use of the robot significantly improved precision. Results for 100 samples from patients after open-heart surgery were highly correlated with manually obtained results for both isoenzyme determinations (r less that 0.96 each). Time to completion for small run sizes for either approach was comparable about 25 min. For larger batches, robotic run time increased rapidly, to 169 min for 24 patients' samples vs 41 min by manual assay.

Microcomputer-assisted interpretative reporting of sequential cardiac profile data.

The authors have developed a microcomputer-based system for interpretative reporting of sequential cardiac profile data, which consists of creatine kinase and lactate dehydrogenase isoenzyme levels. Patient demographic data and test results (total creatine kinase [CK], MB isoenzyme of CK [CK-MB], lactate dehydrogenase isoenzyme 1 [LD-1], and lactate dehydrogenase isoenzyme 2 [LD-2]) are entered manually through the keyboard. Percent MB and LD ratio are calculated. The test results are compared with normal range values, and an interpretative report is generated, including all pertinent demographic information and graphic display of up to 36 previous CK and LD isoenzyme determinations. Interpretative statements are printed beneath the graphic display after analysis of previous test results. The combination of graphic data display and interpretations based on prior data provides useful and accurate information to the cardiologist. Significant discrepancies between computer-assisted and pathologist interpretation were not encountered.

Differential Determination of GOT Isoenzymes in Sera and Organs of Experimental Animals by the Immunochemical Method

Differential Determination of GOT Isoenzymes in Sera and Organs of Experimental Animals by the Immunochemical Method

Stability of lactate dehydrogenase at different storage temperatures

The effect of storing human serum, cord blood serum or heparinized plasma at 25 degrees C, 4 degrees C & -20 degrees C on the activity and isoenzyme distribution of lactate dehydrogenase (LD) was studied. Cellulose acetate and agarose electrophoresis, as well as an immunochemical inhibition technique, were used for isoenzyme quantification. In contrast to previous reports, cryo-instability was found only in specimens stored at 4 degrees C. Serum specimens stored at 25 degrees C and -20 degrees C retained 74% and 87% of total activity after 45 days of storage. LD-1 was stable at all three temperatures, with a maximum loss of 10%. LD-2, LD-3, LD-4, & LD-5 were most labile at 4 degrees C. Specimens that are to be analyzed for total LD or LD isoenzymes should be stored frozen or, if necessary, at room temperature, but not in a refrigerator. Thus, separate storage of specimens for cardiac isoenzymes (LD & creatine kinase) is not necessary. This may eliminate a possible source of falsely elevated LD-1/LD-2 ratios, as well as reducing the labor factor and the corresponding cost of cardiac isoenzyme determinations.

Liquid-chromatographic determination of isoenzymes of alkaline phosphatase in serum and tissue homogenates.

We describe a new method for separating alkaline phosphatase (AP) isoenzymes by means of "high-performance" liquid chromatography. Isoenzymes are eluted from the column (Mono Q HR 5/5, a strong anion-exchanger) with a stepwise gradient of LiCl. The isoenzymes originating from small intestine, bone, liver, and bile were identified by use of tissue homogenates, pathological sera, and heat inactivation.

Rapid electrophoretic determination of neuron-specific enolase isoenzymes in serum.

This assay procedure for each of the two neuron-specific enolases (alpha gamma and gamma gamma) and the non-neuronal enolase (alpha alpha) in serum involves two steps: electrophoretic separation of the three isoenzymes--alpha alpha, alpha gamma, and gamma gamma--on cellulose acetate, and bioluminescence measurement of total enolase activity. From these data, the activity concentrations (U/L) of the three isoenzymes in serum are calculated. Both measurement steps are based on the enzymatic activity of enolase and thus differ from the immunological methods currently in use, which require the availability of specific antibodies. The method is rapid (approximately 30 min for both steps) and requires only 10 microL of serum for the complete analysis. Studies of normal children and adults, and of patients suffering from neuroblastoma and small-cell lung cancer, show that it is suitable for clinical use. Furthermore, the fact that both neuron-specific isoenzymes of enolase can be systematically separated is an advantage over immunological techniques in determining isoenzyme patterns for pathological samples.

The effect of infarct size on atrioventricular and intraventricular conduction disturbances in acute myocardial infarction

The effect of infarct size estimated from serial CK-MB isoenzyme determinations on the incidence of atrioventricular and intraventricular conduction disturbances was examined in 250 patients suffering their first myocardial infarction. The size of the infarct was significantly greater ( P < 0.001) in 72 patients with conduction disturbances than in 178 without conduction defects (54 ± 29 vs. 35 ± 22 CK-MB gEq). The largest size was observed in 10 patients with bifascicular block (71 ± 38 CK-MB gEq). Within the group of patients with intraventricular conduction disturbances, the size of the infarct was significantly greater ( P < 0.01) when localized inferiorly rather than anteriorly (91 ± 10 vs. 58 ± 27 CK-MB gEq). The size in those patients with complete atrioventricular block and anterior infarction was larger than in those with an inferior lesion (76 ± 21 vs. 52 ± 33 CK-MB gEq). The size in those patients with inferior infarction and complete block was significantly greater ( P < 0.05) than in patients with similarly positioned infarction without conduction disturbances (52 ± 33 vs. 35 ± 22 CK-MB gEq). There was no significant difference in the size of infarct when inferior infarction was complicated by first- and second-degree block in comparison to those without conduction defects (38 ± 23 vs. 35 ± 22 CK-MB gEq). A correlation was observed between the size of infarction and the incidence of conduction disturbances ( P < 0.001); the greater the size the higher the incidence of conduction disturbances.