Excerpt from Analysis of Program Activities, National Institutes of Health, 1956: National Institute of Allergy and Infectious DiseasesA newly developed method of blood fractionation, plasmapheresis, has been reported by grantees at Children's Hospital in Philadelphia. By this method, utilizing the Cohn blood fractionator, plasma has been collected 25 times from each of 23 donors in a period of one year. It IS suggested that the procedure could be carried out as often as once weekly. This marked increase over the usual five donations a year is made possible by the action of the fractionator which separates the red blood cells and immediately returns them to the donor.About the PublisherForgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.comThis book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully, any imperfections that remain are intentionally left to preserve the state of such historical works.