The protease and antiprotease of plasmas of patients with cancer and other diseases.

MacFarlane and Biggs (5) recently reviewed the literature dealingwith the plasminogen-plasmin, an active proteolytic enzyme and an antiprotease which are present in plasmas in health and dis ease. Satisfactory quantitative data for the plas minogen-plasmin relationship and for the spon taneously active proteolytic enzyme in disease are limited. Although the antiprotease has been studied rather extensively, its relationship to the proteolytic enzymes is not well established The active proteolytic enzyme observed in the plasmas of diseased individuals has been desig nated chiefly as fibrinolysin and “plasmin.― The characterization of this enzyme is inadequately defined. With a few exceptions (5), the results ob tamed for the activities of this proteolytic enzyme in the plasmas of patients cannot be considered as quantitative. Von Dungern (@) first attempted to determine the trypsin inhibitor quantitatively in the plasmas of patients with osteomyelitis. Subsequently, many observations have been made on antipro tease with a variety of procedures. It is generally agreed that this inhibitor is increased in a large variety of diseases (3, 4). Christensen (1) studied the kinetics of the inhibitor-crystalline trypsin re action and was able to develop a well standardized procedure for determining inhibitor activity. This investigation is concerned with the plas mm,spontaneously activeproteolyticenzymeand antiprotease activities of the plasmas of patients (a) shortly after admissiOn and usually before ther apy is instituted, and (b) at intervals after opera tion or during therapy.