Author : Simon Flexner
Publisher :
Page : 728 pages
File Size : 26,1 MB
Release : 2015-07-21
Category : Science
ISBN : 9781331944997
Excerpt from The Journal of Experimental Medicine, Vol. 20 In previous articles it was shown that connective tissue could be kept outside of the organism in a condition of permanent life. The purpose of the following experiments was to determine the present condition of a strain of connective tissue which, after having undergone 358 passages, has now reached the twenty-ninth month of its life in vitro. The strain of connective tissue was derived from a piece of heart extirpated on January 17, 1912, from a chick embryo seven days old. The fragment of heart pulsated for 104 days and gave rise to a very large number of connective tissue cells. These cells multiplied actively during the last two years, and produced a large amount of connective tissue. At present, a great many cultures are obtained from the strain every week. The dynamic condition of a tissue is manifested by the rate of its growth. The increase in the volume of a fragment of connective tissue can be measured with comparative accuracy. For this the following technique is used. A fragment of tissue is removed from a culture, washed in Ringer solution, and placed in a new medium. It soon becomes surrounded with a ring of new tissue. After forty-eight hours the width of this ring is measured with a micrometer. Under the ordinary conditions of the experiment the thickness of the new tissue is more or less uniform, and its total volume can therefore be estimated fairly accurately by its superficial size. The fragments of tissue usually double in forty-eight hours. But their rapidity of growth is subject to fluctuations dependent upon the character of the medium and upon the condition of the tissue at the time that it is placed in the medium. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This 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.