This series has three easy 5 minute installments. This first installment: Permanent Life of Tissues.
This series is about early twentieth century advances in the life sciences published shortly after Alexis Carrel won the Noble Prize his work on vascular suture and the transplantation of blood vessels and organs in 1912.
This series comprises two essays. The first is from Scientific American; the second is from the head of the Zoology Section of the National Museum of Paris. They were written around 1914. Alexis Carrel achieved the first transplants in history. He also was able to remove organs and keep them alive for extended periods of time.
The “Immortality” of Tissues
By Genevieve Grandcourt
A very evident disadvantage under which medical science has labored has been the impossibility of watching the chemical process set in motion by substances introduced into the body. For this reason various experimenters, from time to time, have attempted to “grow tissues” artificially, in such manner that their development, functions, and decay–under both healthy and diseased conditions–might be studied under the microscope. The only way in which this could be done would be to take a piece of living tissue from the body, and cause its cells to multiply; tissue being made up of an aggregation of cells.
Science has failed to produce a single living cell, that is, a cell which will undergo the process of nuclear division (growth) which is the prime condition of its being; and it seemed equally impossible to cause a cell already living to undergo the same process if deprived of the circulation of the blood. Therefore, when in 1910 it was announced that Dr. Alexis Carrel with his assistant, Dr. M. T. Burrows, had succeeded, scientific credulity was taxed. A well-known French savant expressed the opinion before the Society of Biology in Paris, that as others experimenting along these lines, had witnessed only degeneration and survival of cells, this phenomenon was all Carrel’s discovery amounted to. In view of past experience, indeed, the chances were in favor of a mistake. In 1897, Leo Loeb said that he had produced this artificial growth both within and without the body. Obviously, such development within the organism where the process of utilizing the body-fluids, etc., follows the same course as in nature, takes on the character of grafting rather than of cultivating in a culture medium. As to causing the external growth, it was ten years later before it seems first to have succeeded. In 1907 Harrison, from Johns Hopkins University, furnished details of his research in such form as to be convincing. But his work had reference to the growth of tissues only of coldblooded animals, he having cultivated artificially, nerve fibers from the central nervous system of the frog.
Carrel’s work consisted in extending Harrison’s method to apply to warm-blooded animals, including, of course, mammals; he having primarily in view at this time a more precise knowledge of the laws governing the restoration of tissues, for example, after serious surgical wounds. He and his assistant worked steadily to this end, and succeeded. The tissues of the higher animals, including man, can now be developed in a culture, and such development can be made to correspond to a rigidly precise technique. The feat is accomplished by putting minute pieces of living tissue into a plasmatic (blood) medium which will coagulate. So complicated is this apparently simple matter in its application that only the most exquisite surgical skill is proof against incalculable modifications in results.
Having obtained evidence that tissue can be cultivated in accordance with a formula that may be relied upon to give definite results, the effort was made to grow artificially the various malignant (cancerous) tissues, in turn, of chicken, rat, dog, and human being. Cancerous tissue invariably developed cancer, and so rapidly and extensively that the growth could be observed with the naked eye.
It now became evident that, under the right circumstances, the artificial growth of tissues could be utilized in the study of many problems; such as malignant growth of tissue; certain problems in immunity, as, for example, the production of antitoxins of certain organisms; the regulation of the growth of the organism, or of different parts of the organism; rejuvenation and senility; and the character of the internal secretions of the glands, such as the thyroid which plays a role most important in physical and mental development. The difficulty lay in the fact that the artificial growth was so very short-lived. It was found that by passing the growth into a new medium, and repeating the process, the tissues would begin to grow again; but their life even under these circumstances was limited at the most to twenty days. This was manifestly too short a time in which to study the fundamental questions to which the researchers had addressed themselves. Thereupon, study was taken up to determine the question as to what made these tissues die. It was found that, apparently as incidental to growth, there was the process of decay, due to an inability of the tissues to eliminate waste products.
On January 17, 1912, experiments were commenced to determine whether these effects could be overcome. The observations were on the heart and blood-vessels, artificially grown, of the chicken fetus. These growths were put into a salt solution for a few minutes at different periods of their growth, and then placed in a new plasmatic medium. It was found that by following this method, the tissues could be made to live indefinitely. When an animal is in the early stages of its development, the growth of its tissues is necessarily greater as it matures, there being steady diminution after a certain age until the growth altogether ceases, and the size of the animal is determined. But it was found by subjecting these artificial growths to washings in salt solution that the mass was fifteen times greater at the end of than at the commencement of the third month, showing that they do not grow old at all! In the artificial growth the problem of senility and death is solved.
It was the announcement of this “permanent life of tissues” that caused such a furor in Paris last summer, and several eminent scientists to demand ocular demonstration, because “the discovery, if true, constituted the greatest scientific advance of a generation.”