The activities of choroform activated plasmin, spontaneously active protease (proteolysin) and trypsin inhibitor of the plasma of healthy young men and of patients with cancer and with a variety of acute and chronic diseases were determined.

Observations made on a group of patients shortly after admission to the hospital showed elevated values for the proteolysin and trypsin inhibitor in most cases. No relationship between plasmin, proteolysin, and inhibitor concentrations could be established.

Periodic analyses of the proteolysin and trypsin inhibitor were made on patients (a) after incomplete removal of cancer, (b) after complete removal of cancer, (c) during recovery from pneumonia, and (d) with a variety of chronic diseases. The proteolysin concentration dropped to zero soon after complete surgical removal of a cancer, and in other cases after successful therapy or surgery. The tryspin inhibitor remained elevated for an appreciable period.

The appearance of proteolysin in plasma is associated with necrosis and with inflammatory processes accompanied by elevated temperatures. The trypsin inhibitor concentration remains elevated in patients who have been operated on and in those whose tissues are undergoing readjustment to the normal state.

The significance of the changes noted in the plasmas of diseased individuals is discussed.


This investigation was supported by research grants from the National Cancer Institute. U.S. Public Health Service.

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