Hermann Dr Lang

“PMN-Elastase Assay”: Enzyme Immunoassay for Human Polymorphonuclear Elastase Complexed with α1-Proteinase Inhibitor

A solid phase, enzyme-linked immunoassay is described for the quantitative determination of the complex of human granulocyte elastase (EC 3.4.21.37) with alpha 1-proteinase inhibitor. The assay employs antibody-coated test tubes and it is suitable for routine use in clinical chemistry laboratories. Data for sample stability and test characteristics are given. A reference range of 20-180 micrograms/l elastase in plasma was determined. The diagnostic significance of granulocyte elastase levels in plasma in inflammatory diseases is discussed.

Quantitation of myeloperoxidase from human granulocytes as an inflammation marker by enzyme-linked immunosorbent assay

Myeloperoxidase (donor: H20 2 oxidorcd uctase, EC 1.11.1.7) is a cationic heme enzyme of mol wt of approximately 140,000 whieh is found as a main constituent of the azurophilic granules of polymorphonuclcar lcukoeytes (PMN) and in monocytcs (1]. Myclopcroxidase (MPO) plays an important role in killing bacteria using halide ions as a cofactor [2]. As a consequencc of phagocytosis MPO is discharged into phagolysosomes. Leakagc during phagocytosis or secretion on stimulation by various inflammatory mediators causes th.e appearance of extraccllular MPO activity. MPO activity outside of the cells may either stimulate inflammatory processes by oxidation ofphysiological substrates Jike IgG, C3b, Cl.1-proteinase inhibitor as weil as latent collagenase and by killing cells or may aLternatively modulate mflammatory activity by inactivation of cbemotactic peptides, lysosomal enzymes as weil as Fcand C3b-rcceptors on phagocytes \3]. Quantita tive detennination of MPO in serum or plasma has been accomplished by radioimmunoassay [4] and in cell extracts or tissue extracts by enzyme assays. Here we describe a sandwicb-type enzyme-linked immunosorbent assay for quanti tation of MPO concentration iD plasma, bronchoalveolar lavage fluid or extracts from granulocytes.

Kinetic Determination of Glucose Concentrations with Glucose Dehydrogenase

A manual version and mechanized versions for several types of analyzers are described for the kinetic determination of glucose with glucose dehydrogenase. Results of glucose determinations with and without deproteinization of samples are discussed. The correlation of results with the hexokinase method is shown.