Serial monitoring of the serum isoenzyme patterns of creatine phosphokinase (CPK) and lactate dehydrogenase (LDH) in patients suspected of acute myocardial infarction has become a highly sensitive and specific diagnostic method. The predictable evolution of isoenzyme patterns following infarction permits diagnosis and recognition of early stages, recovery stages and extension of infarction in t...

We assessed the clinical efficacy of a thin-layer agarose electrophoresis assay for lactate dehydrogenase isoenzyme estimation in the diagnosis of acute myocardial infarction. From a population of 228 patients admitted to the Coronary Care Unit with suspected acute myocardial infarction, all 101 positive cases (confirmed by clinical presentation and electrocardiographic changes) were correctly ...

Exactly why N-acetyl-beta-D-glucosaminidase (NAG) excretion is increased in patients with nephrotic syndrome with glomerular lesions is poorly understood. Glomeruli contain less NAG than do proximal tubules. In this study, we have tried to measure the NAG isoenzymes automatically by use of the recently developed fast protein liquid chromatography (FPLC) system, followed by column chromatography...

1. Differentiation and maturation of rabbit bone-marrow erythroid cells was accompanied by a 15-fold decrease in lactate dehydrogenase activity from approx. 0.1pmol of NADH utilized/min per cell in basophilic cells to 0.007 pmol of NADH/min per cell in reticulocytes. 2. In early cells, cell division takes place with a corresponding decrease in cell volume, but the concentration of lactate dehyd...

Two ammonium-inducible, chloroplast-localized NADP-specific glutamate dehydrogenase isoenzymes were purified to homogeneity from Chlorella sorokiniana. These isoenzymes were homopolymers of either alpha- or beta-subunits with molecular weights of 55,500 or 53,000, respectively. The alpha-isoenzyme was preferentially induced at low ammonium concentrations (2 millimolar or lower), whereas only th...

BACKGROUND Paraoxonase 1 (PON1), an esterase that hydrolyzes toxic organophosphates and has antioxidative and antiatherogenic properties, contains a common polymorphism at position 192: glutamine (Q) or arginine (R). The Q and R isoenzymes exhibit different physical and protective properties. We describe 2 methods for quantifying their serum activity levels. METHODS We measured serum hydrolyt...

The chloroplast and cytoplasmic isoenzymes of phosphoglycerate kinase (PGK) (EC. 2.7.2.3) from Hordeum vulgare leaves have been separated and purified for the first time to apparent homogeneity. The method for purifying the isoenzymes is described here and consists of DEAE Sephacel chromatography followed by affinity chromatography on ATP Sepharose. This consistently provided a 500- to 900-fold...

The alkaline phosphatase activity expressed by JAR choriocarcinoma cells was compared to the placental isoenzyme of human alkaline phosphatase by several criteria. JAR cell alkaline phosphatase was similar to the placental isoenzyme with respect to heat and urea stability and sensitivity to most inhibitors, but it differed significantly from placental alkaline phosphatase in its sensitivity to ...

Serial measurements of the MB isoenzyme of creatine kinase, total creatine kinase, aspartate mainotransferase, and urea stable lactate dehydrogenase have been made in the serum of a series of 139 patients admitted with a diagnosis of suspected myocardial infarction. Serum MB isoenzyme measurements have also been made on postoperative surgical patients and patients with medical disorders known t...

Two cases of congestive cardiac failure had unusually high activities of serum lactate dehydrogenase and lactate dehydrogenase isoenzyme-5. Values for isoenzyme-5 exceeding 87% of the total serum activity, and increases of 228- to 380-fold of the upper reference limit, are very uncommon.