Simultaneous determination of free 3-methoxy-4-hydroxymandelic acid and free 3-methoxy-4-hydroxyphenylethyleneglycol in plasma by liquid chromatography with electrochemical detection.

A new assay method is described for the simultaneous determination of free 3-methoxy-4-hydroxymandelic acid and 3-methoxy-4-hydroxyphenylethyleneglycol in plasma utilizing separation and purification by Bio-Gel P-10 followed by high-performance liquid chromatography with electrochemical detection. This technique is sensitive and reliable, and offers an inexpensive and practical alternative to gas chromatographic--mass fragmentographic methods for the monitoring of plasma levels of these catecholamine metabolites in the study of selective metabolic pathways of endogenous norepinephrine originating in the peripheral and the central nervous systems.

Investigation on the interaction of commercial forms of streptokinase and human plasminogen: a potential screening procedure for fibrinolytic inhibitors.

Streptokinase activation of human plasminogen is known to produce several enzymatic entities. Initially, the identification and characterization of these various entities were based on molecular model studies which necessitated highly purified biological materials and sophisticated techniques. However, these conditions cannot always be adhered to when alacrity, precision, and cost are often the prime factors governing the choice of a method for the evaluation of therapeutic agents.

Kinetic studies on soluble and insoluble urokinases.

A water-insoluble urokinase (ins-UK) was prepared by covalent coupling to an electrostatically neutral polyacrylamide derivative. The esteratic activity retained by the bound enzyme is about 70 percent of that of the soluble urokinase (UK). Comparative kinetic studies of these two forms of the enzyme were undertaken on lysine esters: N-alpha-acetyl-L-lysine-methyl ester (ALEe) and N-alpha acetylglycyl-L-lysine methyl ester (AGLMe).