Isoenzyme Values Research Articles

Predictive value of MB isoenzyme of creatine kinase and poisoning severity score in the prognosis of patients with wasp sting

To explore the predictive value of MB isoenzyme of creatine kinase (CK-MB) and poisoning severity score (PSS) in the clinical prognosis of patients with wasp sting. A retrospective study was conducted. The clinical data of patients who were stung by wasps admitted to emergency department of the First Affiliated Hospital of Henan University of Science and Technology from July 2017 to November 2019 were collected. The 24-hour acute physiology and chronic health evaluation II (APACHE II), CK-MB and PSS scores of the patients were collected after admission, and 28-day outcome was recorded. Spearman correlation analysis method was used to analyze the correlation between CK-MB and PSS score. Logistic regression model was used to construct joint predictors, and the receiver operating characteristic (ROC) curve was drawn to evaluate the predictive value of various indicators for 28-day prognosis of patients with wasp stings. Finally 90 patients were included in the analysis. There were 67 patients survived at 28 days, and 23 dead with the 28-day mortality of 25.6%. APACHE II score, CK-MB and PSS score in the death group were significantly higher than those in the survival group [APACHE II score: 19.7±2.7 vs. 13.7±2.3, CK-MB (U/L): 183 (151, 243) vs. 36 (21, 75), PSS score: 17.7±2.6 vs. 9.3±4.5, all P < 0.01]. The correlation analysis showed that CK-MB and PSS score were positively correlated (r = 0.843, P < 0.01). Logistic regression model fitted CK-MB and PSS score, and Hosmer-Lemeshow test showed that the model fitted well. ROC curve analysis showed that the area under ROC curve (AUC) of CK-MB for predicting 28-day outcome was 0.957, the sensitivity was 91.3%, and the specificity was 88.1%; the AUC of PSS score was 0.908, the sensitivity was 91.3%, and the specificity was 90.8%. The AUC of CK-MB combined with PSS score was 0.964, the sensitivity was 100%, and the specificity was 79.4%, indicating that CK-MB combined with PSS score had higher predictive value and higher sensitivity for 28-day prognosis of patients with wasp sting. High CK-MB level and high PSS score in early stage of wasp sting injury indicate poor prognosis. Both CK-MB and PSS score can be used as predictors for predicting the prognosis of patients with wasp stings. In addition, CK-MB combined with PSS score have greater predictive value.

Sarcopenia and sarcopenic obesity as prognostic predictors in hospitalized elderly patients with acute myocardial infarction.

ABSTRACTObjective:To investigate the potential value of sarcopenia and sarcopenic obesity as prognostic predictors in hospitalized elderly patients with acute myocardial infarction.Methods:A cross-sectional study based on data collected from elderly patients with acute myocardial infarction, admitted to a public hospital located in the Northeastern region of Brazil, from April to July 2015. The diagnosis of sarcopenia was based on muscle mass, muscle strength and physical performance measurements. Cardiovascular risk and prognostic markers, such as troponin and creatine kynase MB isoenzyme values, acute myocardial infarction classification according to ST segment elevation, and thrombolysis in myocardial infarction score were used.Results:The sample comprised 99 patients with mean age of 71.6 (±7.4) years. Prevalence of sarcopenia and sarcopenic obesity was 64.6% and 35.4%, respectively. Sarcopenia was more prevalent among males (p=0.017) aged >80 years (p=0.008). Thrombolysis in myocardial infarction was the only marker of cardiovascular risk significantly associated with sarcopenia (p=0.002).Conclusion:Prevalence of sarcopenia was high and associated with thrombolysis in myocardial infarction risk score. Sarcopenic obesity affected approximately one-third of patients and was not associated with any of the prognostic predictors.

Defining Features of Patients who Develop Takotsubo Cardiomyopathy during Myasthenic Crisis: A Systematic Review of Case Studies.

Background.Myasthenic crisis can induce Takotsubo cardiomyopathy leading to transient systolic and diastolic left ventricular dysfunction and wall-motion abnormalities, including the characteristic apical ballooning. We aimed to define the clinical features of this disease entity.Methods.A systematic review was conducted to examine the characteristics of Takotsubo cardiomyopathy presenting in myasthenia gravis patients. Case reports were accessed by searching MEDLINE/PubMed, Google Scholar, CINAHL, and Web of Science databases. 523 articles were identified and 14 were selected for review.Results.Takotsubo cardiomyopathy presenting in myasthenia gravis’ patients tends to affect women between the ages of 40 to 77. History of atrial fibrillation or hypertension was found in a minority of cases. Generalized weakness, fatigue, dysphagia and respiratory distress were common at presentation. Vital signs demonstrated normal blood pressure without tachycardia or bradycardia. Elevated values of troponins, creatine kinase (CK), and CK-MB isoenzymes were recorded. ST-segment elevation followed by T-wave inversion were predominantly found on electrocardiograms. Apical abnormalities in the form of ballooning, hypokinesia, or sparing and reduced left ventricular ejection fraction (≤45%) were observed using transthoracic echocardiogram or left ventriculography. Coronary angiography demonstrated no obstructive lesions. Ventilatory support, cholinesterase inhibitors and glucocorticoids resulted in the recovery or improvement of the left ventricular ejection fraction and hemodynamic stability. Only a minority of patients died of refractory heart failure. Treatment with inotropes and/or vasopressors led to poorer outcomes, including death or intractable heart failure.Conclusion.The management of Takotsubo cardiomyopathy developing in myasthenia gravis patients should focus on addressing the myasthenic crisis, while proving supportive care in and intensive care setting.

Comparison of glutathion-s-transferase A-4 expression values between lumbar spinal canal stenosis and lumbar discal hernia patients

Aim: To compare the glutathione s-transferase α-4 (GSTA4) isoenzymes expression values in patients with lumbar spinal canal stenosis (LSCS) due to ligamentum flavum (LF) hypertrophy with patients no evidence of LF hypertrophy.Material and Methods: 27 LF specimens were obtained from patients with LSCS and 27 LF specimens were obtained from patients with lumbar discal hernia (LDH). Firstly these LF samples were analyzed histologically to identify the fibrosis and elastin degradation values. Then GSTA4 isoenzyme values were measured and compared.Results: The mean LF thickness was significantly higher in the LSCS group than in the LDH group (6.72±0.86 and 3.1±0.7 mm, respectively, p 0.005). Average elastin degradation degree was significantly higher in the LSCS group than LDH group (4.4 ±0.50 vs. 0.18±0.1, respectively, p 0.001). And avarage fibrosis degree was significantly higher in the LSCS group than LDH group (4.41±0.17 vs. 0.96±0.11, respectively, p 0.001). And significantly higherexpression of GSTA4 izoenzyme was observed in the LF samples obtained from patients with LSCS compared with controls (144.1±11.16 vs 51.75±21.53, respectively, p=0.009). Conclusion: Our findings in this study suggest that there is a relationship between LF hypertrophy and GSTA4 isoenzyme expression.

Mining distinct aldehyde dehydrogenase 1 (ALDH1) isoenzymes in gastric cancer.

Aldehyde dehydrogenase 1 (ALDH1) consists of a family of intracellular enzymes, highly expressed in stem cells populations of leukemia and some solid tumors. Up to now, 6 isoforms of ALDH1 have been reported. However, the expression patterns and the identity of ALDH1 isoenzymes contributing to ALDH1 activity, as well as the prognostic values of ALDH1 isoenzymes in cancers all remain to be elucidated. Here, we studied the expressions of ALDH1 transcripts in gastric cancer (GC) compared with the normal controls using the ONCOMINE database. Through the Kaplan-Meier plotter database, which contains updated gene expression data and survival information of 876 GC patients, we also investigated the prognostic values of ALDH1 isoenzymes in GC patients. It was found that when compared with normal tissues, ALDH1A1 mRNA expression was downregulated, whereas ALDH1A3 and ALDH1B1 were upregulated in GC patients. In survival analyses, high ALDH1A1 and ALDH1B1 expressions were associated with better overall survival (OS) in all GC patients. In addition, high transcription activity of ALDH1A1 predicted better OS in gastric intestinal type adenocarcinoma, but not in diffuse gastric adenocarcinoma. GC patients with high mRNA level of ALDH1B1 showed better OS in gastric intestinal type, and worse OS in diffuse type. Oppositely, high transcription activities of ALDH1A2, ALDH1A3 and ALDH1L1 predicted worsen overall survival in GC patients, suggesting that these isoenzymes might be responsible mainly for the ALDH1 activities in GC. These data provides ALDH1A2, ALDH1A3 and ALDH1L1 as excellent potential targets for individualized treatment of GC patients.

Genome-wide association study of perioperative myocardial infarction after coronary artery bypass surgery

ObjectivesIdentification of patient subpopulations susceptible to develop myocardial infarction (MI) or, conversely, those displaying either intrinsic cardioprotective phenotypes or highly responsive to protective interventions remain high-priority knowledge gaps. We sought...

Purification and characterization of xanthine oxidase from liver of the water buffalo Bubalus bubalis

Xanthine oxidase (XO) is an important enzyme with broad medical applications as detecting reagents in many diagnostic kits. In this study, buffalo liver xanthine oxidase (BLXO) was purified to homogeneity by acetone precipitation and chromatography on DEAE-cellulose and Sephacryl S-300 columns with a specific activity of 7.2 units / mg protein which represent 31.3 folds. The native molecular weight of the purified enzyme is 200 kDa and its subunit molecular weight was determined by SDS-PAGE to be 67 kDa. The isoelectric point (pI) value of BLXO isoenzyme is at pH 6.0 – 6.2. It displayed its pH optima at 7.6 and the Km value is 1.1 mM xanthine. FeCl2 increased the activity of BLXO while CuCl2, MnCl2 and ZnCl2 were found to be inhibitors of the purified enzyme. Allopurinol inhibits BLXO competitively and has one binding site on it with Ki value of 0.025mM.

Diagnostic value of heart-type fatty acid binding protein determined by the rapid qualitative chromatographic immunoassay method for the detection of minor myocardial damage in patients presenting with non-ST elevation acute coronary syndrome

The aim of this prospective study was to evaluate the diagnostic value of heart-type fatty acid binding protein (H-FABP) determined by qualitative immunoassay method for the detection of minor myocardial damage (MMD) in patients with non-ST elevation acute coronary syndrome (NSTE-ACS). The study consisted of 62 patients with NSTE-ACS. Cardiac troponin I (cTnI) and creatine kinase MB isoenzyme (CK-MB) values were measured at arrival. Myoglobin and H-FABP were obtained if cTnI level was found to be elevated. A control group included 20 subjects with normal cTnI and CK-MB values. H-FABP was determined by a rapid qualitative immunochromatographic test. Patients were classified as MMD-ACS group if they had abnormal cTnI and normal CK-MB (n=24) and as NSTEMI-ACS group if they had elevated both cTnI and CK-MB (n=38). The diagnostic accuracy of H-FABP for minor myocardial damage was determined using ROC analysis. The sensitivity of the H-FABP was significantly higher for NSTEMI-ACS than for MMD-ACS (44.7% vs 0%, p<0.001) and its specificity was 95% for both groups. The diagnostic efficacy rates for myoglobin and H-FABP were 75% and 43% for MMD-ACS, 74% and 62% for NSTEMI-ACS. Positive predictive value for H-FABP and myoglobin were found to be 0% and 80.8% in MMD-ACS, 94% and 87% in NSTEMI-ACS and negative predictive value was 44% and 69.5% in MMD-ACS, 47.5% and 59% in NSTEMI-ACS, respectively. AUC for myoglobin was significantly greater than that for H-FABP in MMD-ACS group (0.754 vs 0.525, p=0.027). The sensitivity of the H-FABP was significantly higher in patients with >3-fold increase in cTnI than those with <3-fold increase in cTnI (46.8% vs. 6.7%, p<0.001). A positive correlation was found between the magnitude of cTnI rise and H-FABP results (r=0.45, p<0.001). H-FABP determined by the rapid qualitative immunochromatographic test has almost similar diagnostic value to that of myoglobin for identifying NSTEMI-ACS, however, does not seem to represent diagnostic potential for the detection of MMD.

Purification and kinetic study of bone and liver alkaline phosphatase isoenzymes in the dog

To study bone and liver alkaline phosphatases (ALP) in the dog, tissue samples were obtained immediately after death from dogs apparently involved in road traffic accidents. Tissue samples were homogenized, and extracted protein was subjected to diethylaminoethyl cellulose–Sephadex column chromatography equilibrated previously with 0.01 M Tris-hydrochloric acid buffer (pH 7.2) and eluted with linear gradient of ionic strength from 0 to 0.4 M NaCl. Fractions with peak activity of ALP were considered a source of purified enzyme. ALP activity was measured by a kinetic method using p-nitrophenylphosphate as a substrate. The kinetic study was performed using a constant concentration of purified isoenzymes and different concentrations of the substrate. Precise Km values for liver and bone ALP were identified using direct linear plot (Eisenthal–Cornish-Bowden plot). Our study showed that the Km value of liver isoenzyme was 13 times greater than that of bone isoenzyme (3.3 mmol and 0.25 mmol, respectively). This may be due to the physiological role of bone ALP in preparing phosphate for bone mineralization and the retention of phosphates in mineral complexes with calcium in bone tissues.

Adjustments of serum lactate dehydrogenase isoenzymes and their significance in monitoring the treatment in patients with tubercular pyothorax

The adjustments and diagnostic significance of polyacrylamide gel electrophoretic (PAGE) profiles of lactate dehydrogenase isoenzymes (LDH: 1.1.1.27) was evaluated in the sera and pleural fluid of patients with tubercular pyothorax. Sera and pleural fluid samples were randomly collected from 72 and 18 patients respectively at two different timings; first, when patients were admitted to the Hospital and second, after an intensive phase of treatment. Sera of 20 healthy individuals served as control. Our results demonstrate significant differences in sera LDH (sLDH) and pleural fluid LDH (pfLDH) isoenzymes. In patients the order of LDH isoenzyme in sera and pleural fluid followed: LDH-5>-4>-2>-3>-1 and LDH-5>-4>-3>-2>-1 respectively. The ranking of activity levels in control was LDH-2>-1>-3>-5>-4. In the second phase of sampling from 31 patients, values of sLDH isoenzymes showed recovery and resembled profiles of controls. Therefore, the sLDH zymograms of patients can be used as the prognostic marker, since they tend to reach the normal level during recovery signifying the effect of chemotherapy in hospitalized patients. Moreover, according to the present findings on LDH-PAGE profiles, the levels of LDH-5 and-4 rise in pyothorax patients significantly (P<0.05). This elevation along with the rise in total LDH activity may, therefore, be used in the diagnosis and monitoring of tubercular pyothorax.

Alkaline phosphatase and its isoenzyme activity for the evaluation of bone metabolism in children receiving anticonvulsant monotherapy

This study aimed to investigate whether carbamazepine, sodium valproate or phenobarbital as monotherapy in ambulatory epileptic children with adequate sun exposure have some effect on their bone metabolism based on the determination of total serum alkaline phosphatase (AP) levels and its bone isoenzyme activity. Blood samples were obtained from 118 epileptic children (37 on carbamazepine, 47 on sodium valproate and 34 on phenobarbital) and from corresponding healthy controls matched for age, gender and anthropometric parameters. AP and its liver, bone and intestinal isoenzyme levels, other common biochemical markers of bone and liver metabolism and drug levels were measured in the study participants. Patients on carbamazepine or phenobarbital had significantly elevated AP levels accompanied by increased bone and liver isoenzyme activity compared to controls. An increase of bone AP isoenzyme values, correlated with the duration of treatment ( r= 0.49, P= 0.002), was found in children on sodium valproate without, however, a concomitant significant elevation of total AP values. We conclude that children who receive antiepileptic drugs as monotherapy, even when residing in a Mediterranean country with adequate sunlight, may have their bone metabolism affected as indicated by the elevated levels of bone AP isoenzyme. This isoenzyme, but not total AP values, could therefore be used as a marker for the selection of patients who would be benefited by a thorough evaluation of their bone metabolism profile.

Lactic dehydrogenase isoenzymes in cerebrospinal fluid associated with hydrocephalus

Various neurological disorders are associated with specific changes in the level of total lactic dehydrogenase and concentrations of its isoenzymes in the cerebrospinal fluid. We describe the lactic dehydrogenase isoenzyme values in children with hydrocephalus. Cerebrospinal fluid samples collected from 10 patients (2 to 16 mo) with hydrocephalus were analysed for total lactic dehydrogenase activity and lactic dehydrogenase isoenzymes. Findings were compared with those in samples from 15 paediatric patients, with normal results. Mean total lactic dehydrogenase activity in the cerebrospinal fluid was significantly higher in the patients with hydrocephalus (101 ± 23.11 U/L) than in the controls (33.53 ± 5.75 U/L) (p &lt; 0.001). In the control samples, lactic dehydrogenase‐1 was the main fraction, followed by lactic dehydrogenase‐2 and 3; only small concentrations of lactic dehydrogenase‐4 and lactic dehydrogenase‐5 were detected. By contrast, patients with hydrocephalus had lower concentrations of the lactic dehydrogenase‐1 fraction and higher lactic dehydrogenase‐2 and lactic dehydrogenase‐3 concentrations, the differences between these results and those in the control group being statistically significant (p &lt; 0.001). The values for lactic dehydrogenase‐4 and lactic dehydrogenase‐5 were similar in both groups. Conclusion: Findings should be considered together with computed tomography/magnetic resonance imaging and ultrasound scans. The cerebrospinal fluid lactic dehydrogenase profile may prove to be an important predictor of cerebral injury, obstructive hydrocephalus and long‐term neurodevelopmental problems.

Lactic dehydrogenase isoenzymes in cerebrospinal fluid associated with hydrocephalus.

Various neurological disorders are associated with specific changes in the level of total lactic dehydrogenase and concentrations of its isoenzymes in the cerebrospinal fluid. We describe the lactic dehydrogenase isoenzyme values in children with hydrocephalus. Cerebrospinal fluid samples collected from 10 patients (2 to 16 mo) with hydrocephalus were analysed for total lactic dehydrogenase activity and lactic dehydrogenase isoenzymes. Findings were compared with those in samples from 15 paediatric patients, with normal results. Mean total lactic dehydrogenase activity in the cerebrospinal fluid was significantly higher in the patients with hydrocephalus (101 +/- 23.11 U/L) than in the controls (33.53 +/- 5.75 U/L) (p <0.001). In the control samples, lactic dehydrogenase-1 was the main fraction, followed by lactic dehydrogenase-2 and 3; only small concentrations of lactic dehydrogenase-4 and lactic dehydrogenase-5 were detected. By contrast, patients with hydrocephalus had lower concentrations of the lactic dehydrogenase-1 fraction and higher lactic dehydrogenase-2 and lactic dehydrogenase-3 concentrations, the differences between these results and those in the control group being statistically significant (p < 0.001). The values for lactic dehydrogenase-4 and lactic dehydrogenase-5 were similar in both groups. Findings should be considered together with computed tomography/magnetic resonance imaging and ultrasound scans. The cerebrospinal fluid lactic dehydrogenase profile may prove to be an important predictor of cerebral injury, obstructive hydrocephalus and long-term neurodevelopmental problems.

Regulation of protein kinase C by short term hyperglycaemia in human platelets in vivo and in vitro.

Postprandial hyperglycaemia carries an increased risk of macrovascular disease even without Type II (non-insulin-dependent) diabetes mellitus. Chronic hyperglycaemia activates protein kinase C (PKC) in vitro and in vivo but it is not known whether PKC is regulated by short-term post-prandial hyperglycaemia in vivo in humans. We investigated whether PKC is regulated in vivo in hyperglycaemic and hyperinsulinaemic infusion tests and correlated the results to stimulations in vitro. Protein kinase C regulation was measured in platelets obtained from 8 healthy subjects who were infused with glucose and insulin for 2 h attaining peak concentrations of 16 mmol/l glucose and in platelets from 8 healthy young subjects, 8 older subjects without diabetes, and 10 older subjects with Type II diabetes after incubation in vitro with 16 mmol/l glucose or glucose and insulin. For precise quantification, a shortened PKC beta1 standard protein was generated by bacterial expression and PKC alpha, beta1, beta2 and delta isoenzyme values were measured by immunoblot analyses. Hyperglycaemic and hyperinsulinaemic in vivo tests increased the amounts of PKC alpha, beta1 and beta2 in the membrane fraction of platelets to 225 +/- 87 %, 164 +/- 22 % and 302 +/- 135 %, respectively, when compared with the baseline values in young healthy volunteers (n = 8, p < 0.05). The expression of PKC delta did not change. In comparison to the recombinant PKC beta1 standard protein, 5 ng PKC beta1/ microg protein was measured before the test and 2 ng/microg were translocated to the membrane fraction after the infusion. No change in the absolute amount of PKC beta1 was detected. In contrast, after incubation in vitro PKC was not regulated by glucose or glucose and insulin in 8 young healthy subjects (age 26 +/- 0.7 years) and in 8 older, healthy subjects (age 64,8 +/- 4 years) although 100 nmol/l 12-O-tetradecanoylphorbol 13-acetate caused maximal activation. In marked contrast, PKC beta1 and PKC beta2, but not PKC alpha or PKC delta, were increased in vitro in the membrane fraction by 292 +/- 61% and 432 +/- 88% (p < 0.05) in 10 subjects with Type II diabetes mellitus matched for age, sex and BMI. We found that short-term hyperglycaemia activates PKC alpha, beta1 and beta2 in platelets of healthy persons making them potential candidates for mediating the increased cardiovascular risk of postprandial hyperglycaemia. Hyperglycaemia and hyperinsulinaemia did not cause short-term activation of PKC in platelets in vitro suggesting the existence of additional stimuli. Subjects with Type II diabetes showed a markedly altered reactivity of platelet PKC beta in vitro indicating some diabetes-related regulation.

Heparin-coated circuits reduce myocardial injury in heart or heart-lung transplantation: a prospective, randomized study

Background. The effects of heparin-coated (HC) circuits have been primarily investigated in routine cardiac operations with limited duration of cardiopulmonary bypass (CPB) and ischemia. Their benefits have not been conclusively proven but could be more significant when CPB and ischemic times are longer, such as during heart transplantation (HTx) or heart-lung transplantation (HLTx). Methods. In a 22-month period, 29 patients undergoing HTx and HLTx were randomly divided into two groups using HC (Duraflo II, n = 14, 10 HTx and 4 HLTx) or uncoated but identical circuits (NHC group, n = 15, 10 HTx and 5 HLTx). All patients received full systemic heparinization (3 mg/kg) during CPB. Plasma endotoxin, interleukin (IL)-6, IL-8, IL-10, IL-12, and cardiac troponin-I were measured before heparin administration, immediately after aortic cross-clamping, 5, 30, 60, 90, 120 minutes, and 12 and 24 hours after aortic declamping. The intensive care unit (ICU) staff and the laboratory technologists were blinded as to the use of HC circuits. Results. No statistically significant differences between groups were found with respect to all baseline values, duration of CPB and aortic cross-clamping, graft ischemic time, doses of heparin, postoperative blood loss and transfusion, peak lactate and creatine kinase-MB isoenzyme values, duration of mechanical ventilation, or length of ICU stay. One patient in each group died during the hospital stay. Patients in the HC group needed more protamine sulfate after CPB. Although endotoxin levels were similar in the two groups, significantly lower IL-6, IL-8, and IL-10 levels were observed 1 hour after aortic declamping in the HC group. The release of cardiac troponin-I was also significantly reduced in the HC group 12 and 24 hours after reperfusion. Conclusions. The use of HC circuit limits both pro- and anti-inflammatory responses to CPB. It may also reduce myocardial injury after prolonged duration of CPB and ischemia.

Profiles and prognostic values of LDH isoenzymes in patients with non-Hodgkin's lymphoma.

Serum lactic dehydrogenase (LDH) is an important prognostic factor in patients with non-Hodgkin's lymphoma (NHL). We have examined the LDH isoenzyme content in serum and CSF of patients with NHL, at diagnosis and at relapse. In patients with increased serum LDH at diagnosis, the percentage of isoenzyme 2 was increased in 52% of patients and the absolute value of isoenzyme 3 was increased in 64% of patients. In relapsing patients these values were respectively 69% and 65%. Conversely in patients with increased serum LDH due to myeloid regeneration after chemotherapy, isoenzymes 4 and 5, but not isoenzymes 2 or 3, were increased. High absolute values of isoenzyme 3 were correlated with an altered performance status, advanced tumor stage, and aggressive histology whereas high isoenzyme 2 percentages were correlated with altered performance status only. Among patients with high total serum LDH, a high content of isoenzyme 2 and a high absolute value of isoenzyme 3 were correlated with high serum levels of TNFalpha and TNF receptor p75. Analysis of total LDH and LDH isoenzyme profiles in CSF did not reveal any correlation with meningeal involvement by lymphoma. High isoenzyme 2 percentages and high absolute values of isoenzyme 3 in serum were both significantly associated with a shorter freedom-from-progression and overall survival. Isoenzyme 3 remained a prognostic factor for survival even when considering only patients with high total serum LDH at diagnosis. We conclude that there are some characteristic serum LDH isoenzyme profiles in patients with NHL and that some of these specific alterations may help refine the prognostic value of total serum LDH.

Bone alkaline phosphatase isoenzyme in renal osteodystrophy.

Serum total alkaline phosphatase is the most commonly used biochemical marker of bone disease in renal patients, but alkaline phosphatase originates from different organs and sometimes lacks specificity. Bone isoenzyme measurement is considered superior to total alkaline phosphatase for the assessment of bone metabolism. We have studied the value of bone isoenzyme, determined by a new. IRMA (Tandem-R-Ostase), in haemodialysis patients with secondary hyperparathyroidism and renal osteodystrophy. Fifty-six haemodialysis patients were studied. Intact parathyroid hormone (PTH), osteocalcin, total alkaline phosphatase and bone alkaline phosphatase were determined. A transiliac bone biopsy was performed in 20 of the 56 patients after double tetracycline labelling. There was a significant correlation between bone alkaline phosphatase and PTH (r = 0.79, P < 0.001) and between bone and total alkaline phosphatase (r = 0.84, P < 0.001) in all patients. The patients who underwent a bone biopsy showed osteitis fibrosa in 17, mixed lesion in one, adynamic bone disease in one and normal bone in one. Bone alkaline phosphatase showed a significant correlation with static and dynamic histomorphometric indices similar to that obtained with PTH and better than those of total alkaline phosphatase and osteocalcin. It is concluded that bone alkaline phosphatase (ostase) seems to be a useful non-invasive marker of bone metabolism in patients on haemodialysis with high turnover bone disease. More studies are necessary to know its value in low turnover bone disease.

Purification and characterization of two forms of cysteine synthase from Allium tuberosum

Cysteine synthase (CSase) was purified from the leaves of Allium tuberosum. The purification steps including hydrophobic chromatography using EAH-Sepharose 4B resulted in the recovery of two different forms of CSase (isoenzymes A and B). Purified CSase isoenzyme A had a specific activity of 1.36 μkat mg −1 protein and isoenzyme B had a specific activity of 1.0 μkat mg −1 protein. The native M r for isoenzyme A was 80–82 × 10 3 and for B was 72–74 × 10 3. Both isoenzymes were dimers composed of identical subunit M r s which were 40 × 10 3 for A and 36 × 10 3 for B on SDS-PAGE. The K m values of isoenzymes A and B were 6.7 mM and 9.0 mM for O-acetyl- l-serine (OAS), respectively. Data on the substrate specificity show that both isoenzymes catalyse the formation of cysteine derivatives and some heterocyclic β-substituted alanines such as S-allyl- l-cysteine or β-(pyrazol-l-yl)- l-alanine from OAS as an additional catalytic activity. Antiserum produced from purified spinach CSase isoenzyme A was cross-reactive with only isoenzyme A. Several properties, including the amino acid composition of the purified enzymes, are also described.

Preliminary experience with the diagnostic value of the canine corticosteroid-induced alkaline phosphatase isoenzyme in hypercorticism and diabetes mellitus.

The present study communicates the interim experience with the diagnostic value of the canine corticosteroid-induced alkaline phosphatase isoenzyme (CIAP), qualitatively assessed by agarose gel electrophoresis, for the diagnosis of Hypercorticism (prolonged exposure to increased concentrations of exogenous or endogenous corticosteroids) and Diabetes mellitus. A total of 106 canine serum samples with a total alkaline phosphatase activity greater than 2.90 mu kat/l were included. CIAP was identified in 28 out of 29 cases of Hypercorticism, in 7 out of 9 cases of Diabetes mellitus, and in 33 out of 68 cases of various other diseases. Sensitivity and specificity with respect to Hypercorticism were 0.97 and 0.48, respectively, while for Diabetes mellitus sensitivity and specificity were 0.78 and 0.37. From this, the positive and the negative predictive values were calculated using standard formulas. The main conclusion may be summarized as follows: In the dog, only the negative finding of CIAP seems to be of diagnostic value in ruling out Hypercorticism as a cause for an increased total alkaline phosphatase activity.

Serum LDH and LDH Isoenzymes in Chronic Renal Failure: Effect of Hemodialysis

Serum levels of several commonly measured enzymes are abnormal in patients with end-stage renal disease (ESRD). In the present study we measured serum total LDH activity and LDH isoenzymes in a group of 25 ESRD patients shortly before, during, and immediately after hemodialysis. Baseline serum total LDH activity in the ESRD group was midly but significantly higher than that found in the normal control group. The observed elevation was associated with an isomorphic pattern. Single passage of blood through the extracorporeal apparatus led to a rise in total LDH, LDH-3, LDH-2 and LDH-4, a pattern consistent with release from the platelets. A steady increase was noted in total LDH, LDH-5 and LDH-1 of arterial blood during hemodialysis. This was thought to be due to ultrafiltration-induced hemoconcentration, enzyme release from the formed elements within the extracorporeal circuit and complement-mediated leukocyte activation and pulmonary leukostasis. These observations should be taken into consideration with regards to interpretation of LDH and LDH isoenzyme values and proper time of blood sampling in ESRD patients.