Relation of the anti-stiffness factor to collagen disease and calcinosis.

The Relation of the Anti-Stiffness Factor to Collagen Disease and Calcinosis The " anti-stiffness factor " is a fat-soluble vitamin whichregulatesphosphorus metabolism. The object of this communication is to report studies on the possible relations of the anti-stiffness factor to human disease. Since none of the work on the anti-stiffness factor has appeared in journals devoted to clinical matters, the essential experimental findings are briefly summarized below. Sources and Nature of the Anti-Stiffness Factor.-The crude sources of the antistiffness factor are green vegetables, raw cream, unheated molasses, and raw sugarcane juice. The nature of the active principle is still unknown. Active fractions, however, are fat soluble. Reliable assay is difficult; Gouley found that methylvinyl-ketone had some anti-stiffness activity, but this has not been confirmed as the active principle. Oleson and others (1947), and Petering and others (1948), suggested ergostanyl acetate and alpha-ergostanyl acetate respectively as the active principle. Van Wagtendonk and Wulzen (1943) isolated a fat-soluble fraction from raw cream curative in doses of 0 1 ,ug., and (1946) a crystalline substance from molasses and cane juice which was active in doses of 0 * 002 jig. Ross and others (1949) have recently presented evidence for the presence of a steroid compound in cane juice which exhibits anti-stiffness activity.