Determination Of Isoenzymes Research Articles

Diagnosis of induced cleft palate in rats from defective patterns of differentiation of isoenzymes.

Cleft palate was induced in 420 embryos of Sprague-Dawley rats with a single oral dose of 600 mg/kg beta-aminoproprionitrile (BAPN) on embryonal day 15, 7 hours. The cleft palate was accompanied by a pathological differentiation pattern of various isoenzymes in palatal shelves. These isoenzymes could be detected in amniotic fluid from the 16th to the 20th days of pregnancy when they also had a pathological differentiation pattern. We conclude that teratogenically induced cleft palate in rats is accompanied by a pathological differentiation pattern that can be traced by determination of isoenzymes in the palatal shelves as well as in amniotic fluid.

Serum creatine kinase activity and sensing characteristics after intraoperative arrhythmia induction using implantable defibrillator rate sensing leads.

In 29 patients (24 men, 5 woman, mean age 57 +/- 14 years) we evaluated the effect of intraoperative arrhythmia induction during implantable defibrillator (ICD) placement using alternating current (AC) applied through the epicardial rate sensing leads on acute and chronic pacing thresholds, electrogram amplitudes, slew rates and serum creatine kinase levels. In 15 patients undergoing new ICD implantation, pacing thresholds, electrogram amplitudes, slew rates, and resistances were measured before and following at least three inductions of ventricular fibrillation (VF) using AC applied through the epicardial rate sensing leads. Fourteen patients who underwent VF induction using AC through the epicardial leads during initial implant (mean time of 31 months previously) underwent ICD pulse generator replacement only with parameters measured as above before and after at least two inductions, and these compared to the values at initial implant. In all 29 patients serum creatine kinase levels were obtained before, immediately following, and at 8, 16, and 24 hours after surgery. No significant change in acute pacing threshold, electrogram amplitude, slew rate or resistance occurred. Chronically there was an expected 154% increase in pacing threshold but no significant change in electrogram amplitude or resistance. Serial serum creatine kinase and MB isoenzyme determinations demonstrated no evidence of myocardial necrosis. We conclude that intraoperative arrhythmia induction during ICD implantation using AC applied through the rate sensing leads is a safe and effective technique.

The diagnostic significance of lactate dehydrogenase isoenzymes in urinary cytology

Lactate dehydrogenase (LDH) isoenzyme distribution was examined in 106 urine samples being tested cytologically for evidence of bladder cancer; the samples were selected to have less than 20 leucocytes and erythrocytes per high power field and the LDH pattern determined by electrophoresis. The Papanicolaou stained-smears showed 68 negative, 17 suspicious and 21 positive. The LDH M-fraction of the urinary supernatant in cytologically positive cases was significantly greater than in negative cases, although the latter included a few false negative samples. Some of the false negatives gave positive results for the LDH M-fraction; these results suggest that the determination of LDH isoenzymes in the urine is useful in diagnosing urinary tract cancers, including early stage, and for follow-up of patients with bladder cancers after surgical resection.

Semi-Automated fluorometric assay for urinary total and b n-acetyl-β-d-glucosaminidase: Analytical investigation

Total N-acetyl-beta-D-glucosaminidase (NAG) and NAG-B isoenzyme determination are determined in order to investigate renal tubular function. Here, we propose a semi-automated adaptation of Sandman's manual method for the Monarch centrifugal analyzer. Fluorescence of the released 4-methylumbelliferone is automatically read and results are directly expressed in nanokatal/l. Mean (1 SD) values expressed in nanokatal/millimole creatinine in urine from healthy female (n = 30) and male (n = 30) subjects were 8.2 (4.0) and 7.8 (2.9) for total NAG and 1.9 (1.4) and 1.5 (0.7) for the NAG-B isoenzyme activity. The assay of six patients with various renal disorders shows definite increase in total NAG and NAG-B isoenzyme activities.

Effect of reticulocytosis on lactate dehydrogenase isoenzyme distribution in serum: in vivo and in vitro studies

We investigated the effect of reticulocytosis on the lactate dehydrogenase (LD; EC 1.1.1.27) isoenzyme LD1/LD2 ratio in patients with and without evidence of hemolytic disease. Analysis of sera from patients with reticulocytosis and in vivo hemolysis showed a mean LD1/LD2 ratio of 0.92 compared with a ratio of 0.69 in patients with in vivo hemolysis and normal reticulocyte counts. Determination of LD isoenzymes in erythrocyte lysate revealed significantly increased LD1/LD2 ratios for patients with marked reticulocytosis compared with those for patients with normal-to-minimal increases in reticulocytes. Finally, separation of mature erythrocytes and reticulocytes by flow cytometry revealed marked differences in the LD1/LD2 isoenzyme distribution between these two cell types. The ability of hemolysis to cause a "flipped" LD1/LD2 ratio is dependent on the proportion of the hemolyzed cells that are reticulocytes.

Aspartate aminotransferase isoenzymes

Aspartate aminotransferase (AST, EC 2.6.1.1) exists in human tissues as two distinct isoenzymes, one located in the cytoplasm (c-AST), and the other in mitochondria (m-AST). Striated muscle, myocardium, and liver tissues are the main sources of AST. A growing body of information suggests that determination of AST isoenzymes in human serum is useful in evaluating damage to some of these organs. In hepatic disease, the test is used to assess liver necrosis and for determining prognosis. It may also assist in identifying patients with active alcoholic liver disease. In patients with acute myocardial infarction, measurement of AST isoenzymes provides diagnostic information that differs from that obtained by determination of total creatine kinase and lactate dehydrogenase enzymes, and their isoenzymes.

Prenatal Diagnosis by Isoenzymic Differentiation of Treacher Collins' Syndrome Induced by Retinoids in Rats

A series of branchial arch malformations was induced in 618 embryos from 72 pregnant rats by a single intraperitoneal injection of 10 mg/kg etretinate at 8.5 days of gestation. The litters developed several malformations, including microtia, low set and dorsally placed outer ears, defective middle ear ossicles, short cochleas, defectively differentiated Meckel's cartilages, micrognathia, rudimentary malar bones, lateral facial clefts, fistulas and skin tags, all of which were similar to Treacher Collins' syndrome in man. The defects were accompanied by a pathological differentiation pattern of various isoenzymes in maxillary and mandibular processes. These isoenzymes could be detected in amniotic fluid from the 9th to the 20th days of pregnancy and showed a pathological differentiation pattern here as well. We conclude that a teratogenically induced syndrome affecting the first and second branchial arches is accompanied by a pathological differentiation pattern that can be traced by determinations of isoenzymes in the branchial arches as well as in amniotic fluid.

Sensitive, simple staining method for use in electrophoretic determination of amylase isoenzymes in serum.

We have developed a sensitive and simple staining method for use in electrophoretic analysis of serum alpha-amylase (EC 3.2.1.1) isoenzymes. The principle of this method is as follows. alpha-Amylase hydrolyzes 4-nitrophenylmaltoheptaoside to generate oligosaccharide, which is then converted to gluconolactone in the presence of oligosaccharide dehydrogenase (no EC no. assigned), with concomitant reduction of 1-methoxy-5-methylphenazinium methylsulfate (1-m-PMS) to 1-m-PMSH. The hydrogen in 1-m-PMSH is then transferred to 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide to yield formazan. Each of the isoenzymes can then be measured densitometrically. The mean (and SD) values for total amylase, P1, S1, and S2 as determined by this method with sera from 25 healthy adults in fasting were 251 (64), 104 (35), 126 (40), and 22 (11) U/L, respectively. Between-assay CVs (n = 10) for determinations of P1, S1, and S2 were 3.54%, 4.03%, and 7.01%, respectively.

In Reply: Conflicting Results of Liquid-Chromatographic Determinations of Alkaline Phosphatase Isoenzymes

In Reply: Conflicting Results of Liquid-Chromatographic Determinations of Alkaline Phosphatase Isoenzymes

Conflicting results of liquid-chromatographic determinations of alkaline phosphatase isoenzymes.

Conflicting results of liquid-chromatographic determinations of alkaline phosphatase isoenzymes.

Clinical value of an amplified electrophoretic determination of enolase isoenzymes in small cell lung carcinoma patients : Batandier C, Brambilla E, Nagy-Mignotte H, et al. Enzymology Laboratory, Centre Hospitalier Regional, Universitare de Grenoble, Faculte de Medecine-Pharmacie, Grenoble. Scand J Clin Lab Invest 1989;49:33–42

Clinical value of an amplified electrophoretic determination of enolase isoenzymes in small cell lung carcinoma patients : Batandier C, Brambilla E, Nagy-Mignotte H, et al. Enzymology Laboratory, Centre Hospitalier Regional, Universitare de Grenoble, Faculte de Medecine-Pharmacie, Grenoble. Scand J Clin Lab Invest 1989;49:33–42

Comparison of two methods for the determination of the isoenzymes of a-amylase in serum and urine

Comparison of two methods for the determination of the isoenzymes of a-amylase in serum and urine

Does Anesthetic Technique Make a Difference? Augmentation of Systolic Blood Pressure During Carotid Endarterectomy

SMITH, J. S.; ROIZEN, M. F.; CAHALAN, M. K.; BENEFIEL, D. J.; BEAUPRE, P. N.; SOHN, Y. J.; BYRD, B. F.; SCHILLER, N. B.; STONEY, R. J.; EHRENFELD, W. K.; ELLIS, J. E.; ARONSON, S. Author Information

A prospective evaluation of 68 patients suffering blunt chest trauma for evidence of cardiac injury.

The prevalence and significance of cardiac injury following blunt chest trauma is largely unknown. Although electrocardiography (ECG) and creatinine phosphokinase isoenzyme (CPK-MB) determination have traditionally been used in determining cardiac injury, recent developments in two-dimensional echocardiography (ECHO) as a noninvasive diagnostic tool have led to its use in detecting structural cardiac damage following trauma. In an attempt to determine the occurrence and consequences of cardiac injury we prospectively evaluated 68 patients at one institution using ECHO, serial ECG, and serial CPK-MB determinations in the first 3 days following hospital admission. Patients were selected who had evidence of blunt chest injury on examination or by mechanism of injury. The mean age of the 68 patients was 36.3 +/- 19.6 years and the mean Injury Severity Score, 21.5 +/- 11.6. Forty-nine patients (72%) were found to have an abnormal ECHO, ECG, or CPK-MB (greater than 3%). Eighteen patients (26%) had abnormal ECHOs consisting of seven right ventricular contusions, three left ventricular contusions, three contusions of both chambers, four pericardial effusions, and one small ventricular septal defect. Only three contusions were associated with elevated CPK-MB and seven with abnormal ECGs. Abnormalities of ECG included 18 patients with S-T, T wave changes, axis shifts (11 patients), and bundle branch or hemiblocks (10 patients). No patient died or experienced serious morbidity as a result of their cardiac injury, including 12 patients who underwent surgical procedures with general anesthesia within 30 days of admission.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiac Isoenzyme Values After Total Joint Arthroplasty

The purpose of this study was to prospectively determine what effect total joint arthroplasty had on the myocardial-associated isoenzymes of serum creatine kinase (CK-MB) and lactate dehydrogenase (LD-1:LD-2). Fifty patients treated with total joint arthroplasty of the hip or knee had isoenzyme determinations using automated spectrophotometry and agarose gel electrophoresis. Skeletal muscle injury associated with the trauma of surgery resulted in significant elevations of the absolute value of CK-MB; however, the percentage of CK-MB comprising total CK activity and LD-1:LD-2 did not rise significantly in patients who did not experience postoperative myocardial infarction. It is important to determine both serum CK-MB and LD-1:LD-2 in suspected postoperative myocardial infarction since false positive elevations of CK-MB can occur. Elevations of CK-MB exceeding 50 International Units/liter or 5% of the total CK activity combined with LD-1:LD-2 exceeding 1.0 should not be attributed to skeletal muscle injury alone following total joint arthroplasty of the hip or knee.

Value of creatinine phosphokinase isoenzyme determinations in the diagnosis of myocardial contusion: Lindenbaum GA, Carroll SF, Block EF, Kapusnick RA. Ann Emerg Med 1988;17:885-9

Value of creatinine phosphokinase isoenzyme determinations in the diagnosis of myocardial contusion: Lindenbaum GA, Carroll SF, Block EF, Kapusnick RA. Ann Emerg Med 1988;17:885-9

Diagnosis of acute myocardial infarction from two measurements of creatine kinase isoenzyme MB with use of nonparametric probability estimation.

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.

The development of an immunosensor for the electrochemical determination of the isoenzyme LDH5

In this work we describe an immunoelectrochemical technique for the determination of LDH isoenzymes. The method is based on the covalent binding of monoclonal antibody against the isoenzyme LDH5 to a glassy carbon electrode, and the exploitation of the electrode surface as the solid phase for enzyme immunoassay. The resulting enzyme electrode was studied by a computerized electrochemical system. This combination formed the basis of a highly sensitive fast and convenient technique for the determination of the LDH isoenzymes in sera.

Clinical value of an amplified electrophoretic determination of enolase isoenzymes in small cell lung carcinoma patients

Neurone specific enolase (NSE); alpha gamma and gamma gamma isoenzymes of the glycolytic enzyme enolase, is found in considerable quantity in serum of patients with small cell lung cancer (SCLC). The spectrophotometric measurement of serum enolase activity, plus the electrophoretic separation of isoenzymes (alpha alpha, alpha gamma and gamma gamma) using an amplification reaction constitute a simple method, the application of which has not yet been demonstrated. In patients, serum values of higher than 25 U/l of total enolase activity, with more than 10% NSE, were considered to be positive. Seventy patients diagnosed as SCLC were classified before treatment as having either limited (LD) or extensive (ED) disease, and after chemotherapy as being in complete (CR) or partial remission (PR), stable state (SS) or in relapse (R). The levels of enolase activity and NSE (M +/- SE) in these patients (enolase: 67 +/- 7 U/l, NSE 27 +/- 2%) were different from those in a control group of 19 patients with non-small cell lung cancer (enolase: 29 +/- 2 U/l, NSE: 7 +/- 1%) (p less than 0.001) at the time of diagnosis. Mean enolase and NSE levels in patients with SCLC were seen to differ significantly according to the clinical stage. The results of those patients with ED differed from those of patients with LD (p less than 0.001). The results of the group of patients that achieved remission differed from that of patients during relapse (p less than 0.0001). Serial measurements demonstrated a good correlation between enolase and NSE serum levels and the progression of the disease. The usefulness of this method in the early assessment of treatment was also demonstrated. The clinical usefulness of the dosage of NSE with that of two other tumour markers CKBB and mitochondrial CK was compared.

Determination of human aspartate aminotransferase isoenzymes by their differential sensitivity to proteases

The effect of various proteases (trypsin, chymotrypsin, subtilisin, protease 401, and thermolysin) on the mitochondrial isoenzyme (m-AST) and cytoplasmic isoenzyme (c-AST) of human and swine aspartate aminotransferase (AST;EC 2.6.1.1) was evaluated. All procedures including the reaction with proteases and the subsequent determination of the AST activity were carried out in an automatic analyzer. The mammalian c-AST was efficiently inactivated by chymotrypsin, subtilisin and protease 401 while m-AST activity decreased very slowly with these proteases. Thermolysin and trypsin showed much less effect on c-AST activity. Especially, chymotrypsin at concentrations of 0.5-1.0 g/L inactivated human c-AST almost completely but showed no detectable inactivating effect on m-AST. Thus chymotrypsin appears to be the most suitable protease for the differential determination of AST isoenzymes in human serum. Further studies on the effects of proteases with AST from other species showed that Escherichia coli AST resembled mammalian m-AST while Pseudomonas AST resembled c-AST.