Spectrographic Studies of Cancer and Normal Blood Plasma: II. Absorption Spectra of Fractionated Cancer and Normal Human Blood Plasma

Abstract

Introduction In the experiments on the absorption of normal and cancer rat plasma fractionated with zinc hydroxide powder, described in the preceding paper (1), it was found that the absorption curves of normal rat plasma treated with zinc hydroxide powder were practically identical between the wavelengths of 2900 A and 3400 A while those of cancer rat plasma, similarly treated, deviated from the normal, the deviation being roughly proportional to the size of the tumor growth. In the present study, on human plasma, the same technic was employed to determine whether a similar difference exists. Results Absorption curves typical of those obtained are shown in Fig. 1; these were obtained from a healthy subject, Case 26. Curve A is that of undiluted plasma; curve B of plasma diluted five times; curve C of plasma diluted five times and treated with 0.1 gm. of zinc hydroxide powder per 5 c.c. of diluted plasma, and curve D of plasma diluted twenty times. Such determinations were made on 12 cancer and 7 normal plasmas. A careful examination of these curves was made to discover any possible correlation between the shape of the curves and the pathological condition of the subject. The height of the band at approximately 2780 A, which is a rough measure of the protein content, varied over a wide range in both cancer and normal plasmas, and nothing peculiar to the cancerous condition could be detected. The extinction coefficients in the region of 2900 A to 3100 A of plasma after treatment with 0.1 gm. of zinc hydroxide powder (curve C) gave no consistent values for these human specimens as was the case for rats (1). The ratio of the maximum extinction coefficient of the plasma treated with zinc hydroxide powder (curve C) to that of the untreated plasma of the same dilution (curve B) for the 2800 A band was, however, found to be greater for normal plasmas than for cancer plasmas. The work, therefore, was continued along this line.