Failure to observe pentolysis by the serum of rats bearing malignant tumors.

In 1944, Bevilotti (1) reported that the red corpuscles of patients with malignant tumors de grade pentoses in vitro, while the red cells of normal subjects, or of patients with benign tu mors, do not have this effect. Menkes (5-8) ob served a similar action by blood serum. He found that when the sera of patients with malignant tumors were incubated at 37° C. with pentoses (o-ribose, D-xylose, D-arabinose, or L-xylose) deg radation of the pentose occurred with formation of lactic and pyruvic acids. Normal sera and the sera of patients with benign tumors and chronic diseases, such as tuberculosis, cirrhosis, diabetes, and nephritis, did not exhibit this effect. Menkes called this process "pentolysis," since it appeared