On the Differentiation of BCG Inoculated and Naturally Infected Individuals With Polysaccharide and Polypeptide Fraction of Tuberculin

It was about ten years ago that Kasuya has pointed out that there are at least two kinds of factors in the active priciples of tuberculin different as well in its biological significance as its chemical properties. The one is protein derivative in nature as the majority of investigators as Seibert, Kallós and, Hoffmann Gough, and Maschmann and Küster, has reported ; while the other is polysaccharide in nature having a definite skin reaction to individuals who has just recovered from Primary infection or suffering from active pulmonary tuberculosis at present time.This finding seemed to have no particular attention paid in this country except it was supported by Prof. Toda, and his collaborator in the early period. Meanwhile recently, in view of the importance of the study of the epidemiology of tuberculosis, it seemd to authors necessary, to repeat this investigation once more to ascertain, whether at first the biological activity of polysaccharide measured by skin test is essentially exist or not, and secondary, what is the significance of its positive reaction if it truly exist. Fortunately, last year we could have an opportunity to make a survey about the 1000 school children, the result of which appeared to favor the previous opinion of Kasuya mentioned above. Recently we were chanced to read the articles of Dr. F. B. Seibert, where it was mentioned on the presence of at least two kinds of tuberculin protein different in biological and physico-chemical significances. The correlation of this evidence-to our finding will be discussed later.