Penicillin, Plasma Fractionation and the Physician
by DR. JOHN F. FULTON
1
RECENT news releases from the Surgeon General of the Army repeatedly mention that, whereas in the First World War twelve to fifteen per cent of the wounded brought to front-line hospitals died, only three per cent or thereabouts have succumbed in similar circumstances during the Second World War. Surgeon General Kirk is inclined to attribute this remarkable improvement to better surgery; broadly speaking, he is correct, but the term “better surgery” requires explanation.
The lay press usually credits the great gain to the sulfa drugs and penicillin, and, while there is some basis for this inference, it is also true that in the hands of some of our less experienced colleagues in liberated areas the sulfa drugs and penicillin have caused little improvement in their mortality statistics. The advocates of air evacuation suggest that the greater speed in the movement of the wounded has played an important part in reducing mortality; here too a case can be made, but for obvious reasons it cannot be the whole story. From Red Cross Headquarters we hear that plasma and plasma fractions prepared under the Navy blood-fractionation program have been primarily responsible for saving the lives of this war’s wounded; plasma has been important, but in recent months it has probably been less significant than whole blood, which has also been made available through the Red Cross blood-collection program.
Certain thoughtful persons familiar with the background of American medicine during the past thirty years suggest that the reason the Surgeons General of our Army and Navy are able to cite statistics so unbelievably favorable lies not in penicillin or in blood plasma, nor yet in air evacuation or improved surgical techniques, but in the fact that during the past thirty years the medical schools and hospitals in this country have, until this war began, progressively improved their standards of medical education; and that since the end of the last war they have turned out a more highly trained, resourceful, and generally competent body of physicians and surgeons than any other nation, except possibly Great Britain.
First in order of importance, then, in explaining the reduction in mortality rates, is the fact that our wounded at the battle fronts are coming under the care of better trained and educated medical officers than in the last war. Next is the fact that medical units now actually accompany assault boats and paratroops in their landings and in all other frontline operations, with the result that the wounded receive treatment more promptly than in any previous armed conflict of which there is record. In the third place, we must acknowledge the enormous benefit derived from the new therapeutic agents and technical procedures, penicillin leading the list with the adjuvant agents of the sulfa group. A fourth factor lies in the various blood derivatives and whole blood. Finally, our wounded have benefited from improved surgical procedures, many of which have been made possible by penicillin and the sulfa drugs, since surgeons now need worry little about infection complicating the wounds.
Several of the advances in medicine and surgery that have come as a direct result of the war will be described here individually, but I would reiterate that the reason we have fared so well lies primarily in the fact that we had such a large reservoir of highly trained young physicians from which the armed forces were able to draw. We should reflect long and seriously on this point because our military forces, the Army in particular, have unwittingly done everything conceivable — and continue in this ill-timed policy — to lower the standards of medical education in this country and to hinder adequate training of premedical students. Moreover, through the accelerated teaching schedule on which they have sternly insisted, the Medical Departments of the Army and Navy have thrown to the four winds nearly everything that we had learned about medical education in the past fifty years. They have ignored our standards and requirements so completely that the medical schools of this country are now in the unenviable position of being unable to select their students on the basis of merit. Because of the continued refusal of the Congress, Selective Service and the Secretary of War to defer students preparing for the professions, there are virtually no physically fit male applicants from whom to select.
On this point the British learned their lesson in the last war, for they lost men such as Keith Lucas, the distinguished young Cambridge physiologist, and hundreds of others like him, and their “Schedule of Reserved Occupations” in this war in consequence made it mandatory that a proportion of their younger talent should be deferred for the professions. Our colleagues in the Soviet Union have done the same; in fact, they have gone even further than the British in deferring students entering the sciences. But we have deliberately and recklessly refused to defer or otherwise to protect — save in very rare instances -our younger scientific talent. I mention this first as the principal black mark on our otherwise remarkable war record; the damage done, though grave, is not irreparable, particularly if our academic institutions have the courage of their convictions, and on the basis of their accumulated experience have the will to insist firmly, from the moment the Japanese war is ended, that the high standards of medical training (undergraduate and postgraduate) shall be restored to the exacting pre-war level.
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THE other side of the picture is brighter, far brighter. What medical students of the war years have lost in basic training and in the broader cultural backgrounds which should have been theirs, they have gained in the newer fruits of medical research which have come during the war period, many of them as a direct result of the war. I shall mention penicillin first since its story carries many poignant lessons.
In the first place, unlike the blood fractionation program, penicillin was not a product of war research; rather, it came as a result of a broadly conceived academic research program which long antedated the war. Its large-scale production, however, would not have come about so soon had it not been for the war. The development of penicillin and its recognition as the most important therapeutic agent ever to be int reduced into the healing art lacks, as did the introduction of surgical anesthesia, the element of a clear-cut and isolated discovery for which full credit should be given to one man. “Discoveries” are not made this way.
On account of their having shunned the public press (somewhat to their own detriment), the group at Oxford which has been responsible for establishing the therapeutic usefulness of penicillin is often not mentioned in popular accounts of the drug — this because of the earlier and much dramatized story of how the potentialities of penicillin were first recognized by Alexander Fleming in 1929.
Fleming, one day, permitted the open dishes on which he was growing colonies of bacteria to remain uncovered before an open window. Air-borne fungus spores settled on the dishes, and within a few hours spots of fungus mold began growing side by side with the bacterial colonies. Instead of casting the contaminated cultures aside he took note of the fact that individual colonies of bacteria adjacent to the mold growth had ceased to develop — in fact their growth had been actively inhibited. Obviously, therefore, the mold sent forth into the culture medium something inimical to the life of the bacteria.
The principle underlying the therapeutic action of penicillin is therefore extremely simple. In layman’s language, when one colony of micro-organisms grow side by side in a dish of agar with another colony, they may either grow happily together, or the presence of one colony may arrest the growth of the other colony. Pasteur, toward the end of the last century, had noted that some bacterial colonies completely arrested the growth of other colonies. Sir Howard Florey, who has recently delved into the history of these growth antagonisms, states that many instances of such recorded antagonisms can be traced between the time of Pasteur and the publication of Fleming’s celebrated paper in 1929. Gustave Gratia, the Belgian bacteriologist, for example, in 1924 made an extract of a streplothrix that arrested growth in colonies of staphylococci, and he actually subjected the extract to therapeutic trial by local application to infected areas of human skin, he believed with beneficial result; but Gratia did not carry his experimentation beyond this point.
To Fleming must be given credit for having focused world attention on the problem. He observed arrest of growth in colonies of pathogenic organisms, such as streptococci and meningococci, contaminated by a mold, later identified as Penicillium notatum. Like Gratia, he envisaged the possibility of making extracts of the mold, and he carried out preliminary experiments in this direction. But whereas the broth in which the mold was growing had strong antibacterial properties, these properties were lost when he attempted by extraction to obtain the active agent. After a number of trials of this character, he concluded that the active agent, which he had named “penicillin,” was too unstable to be used therapeutically.
Although Fleming did not succeed in making penicillin available therapeutically, he recognized the great possibilities which were inherent in the new agent should anyone succeed in extracting and purifying it. He also named it and he proved that, unlike other antiseptics, it was freely diffusible in animal tissues and in substances such as gelatin. He also established the fact that the crude broth was nontoxic, and by means of a simple experiment demonstrated that, whereas antiseptics such as carbolic acid killed the white blood cells (which are normally responsible for killing any bacteria that may invade the blood stream), penicillin broth, even when concentrated, in no way affected the white blood cells and yet it quickly destroyed pathogenic bacteria introduced among them.
The problem rested there for ten years until Howard Florey and the resourceful team with which he surrounded himself in 1938 and 1939 took up the work anew. There are many parallels between the history of penicillin and the discovery —of which every Bostonian is proud — of the agent in liver responsible for the cure of pernicious anemia. About 1924, Dr. George Minot, who was interested in pernicious anemia, became convinced that it might respond to a specific diet. He and his colleague, Dr. William Murphy, tried many foods, including beefsteak in large quantities, kidney, sweetbreads, and so on, but they were put off from trying liver by the fact that Dr. George Whipple had shown liver to be effective in promoting red-blood-cell regeneration following hemorrhage. Since pernicious anemia as a clinical entity was obviously quite different from hemorrhagic anemia, he thought it highly improbable that liver would be effective in pernicious anemia. Contrary to the general supposition, therefore, Whipple’s work actually delayed Minot’s discovery rather than expedited it.
Sir Howard Florey had long been interested in the problem of suppressing bacterial growth by specific agents from various sources in the plant and animal kingdom, and in 1930 he published an important paper on the so-called “lysozymes,” specific agents in animal tissues which suppress the growth of pathogenic microbes.1 Florey, accordingly, began to look to other sources. He was reluctant at first to try penicillin, even as Minot had been reluctant to try liver, because Fleming had declared it unstable. However, he and his associate, Dr. E. Chain, decided to try penicillin, since the other agents, several of which were highly bactericidal, had proved toxic when given to animals. One of them, which was five times more potent than penicillin in destroying organisms, proved to have an insidious, delayed toxicity which did not manifest itself until two to three weeks had elapsed after the initial injection. The animals then quite suddenly developed a fatal degeneration of the liver.
Experiments on penicillin were undertaken at Oxford early in 1939. The group of investigators was obliged to grow its own mold from a strain supplied by Fleming. Dr. Chain, a Continental biochemist, devised an extraction procedure (similar in some respects to that developed in 1926 by Dr. Edwin Cohn for liver extract), and in the early months of 1939 they succeeded in producing small amounts of a stable, but as yet impure, solution of penicillin which protected mice against large injections of highly virulent organisms such as streptococci. They were able to prove, furthermore, that this stable solution showed little toxicity. In 1940, Chain and Florey prepared a dry brown powder which was freely soluble in water and which retained antibacterial properties for an indefinite period. In solution the potency of the preparation rapidly deteriorated.
Dr. Norman Heatley of Florey’s team must be given principal credit for developing methods of assay. The strength of each new strain had to be tested; without testing methods it would have been impossible to determine the effectiveness of the different molds or of the various methods of extraction. It is worthy of emphasis in this connection that all the preliminary work that led to establishment of the therapeutic effectiveness of penicillin was carried out on animals. Without animal experimentation we should never have had penicillin for use in man. It is impossible as yet to estimate how many lives have actually been saved so far by penicillin, since not all the factors can be readily appraised, but I should think it no exaggeration to say that the handful of mice, rats, and cats which Howard Florey and his colleagues used during 1939 and 1940 has already saved many thousands of human lives in the war theaters alone.
3
THE history of penicillin falls largely into three phases: (1) Fleming’s initial observation, which, although important, ended in failure as far as practical therapeutic application was concerned; (2) the successful extraction and purification of penicillin by Florey and his collaborators and the demonstration of its therapeutic properties; (3) the remarkable feat of commercial production, for which our resourceful and energetic drug houses, working under the direction of Dr. A. Newton Richards, Professor of Pharmacology at the University of Pennsylvania and Chairman of the Committee on Medical Research, are largely responsible.
The history of this commercial production can be quickly told. During the winter of 1940-1941 Florey, working with his wife Dr. Ethel Florey and with Dr. C. M. Fletcher, experienced clinicians, succeeded in restoring with their penicillin solution four of six moribund human beings, all of whom were near death from advanced blood-stream infections — infections that had been untouched by the sulfa drugs. This clinical evidence was promising, but the war was going badly for England then, and there was no possibility of introducing large-scale production of the drug; consequently Dr. Florey came to this country with his associate, Dr. Norman Heatley, in July, 1941, having been backed in the enterprise by Dr. Daniel O’Brien, head of the London office of the Rockefeller Foundation.
On his arrival Florey was put immediately in touch with Dr. Ross G. Harrison, Professor Emeritus of Zoology at Yale, and Chairman of the National Research Council in Washington. Dr. Florey’s clinical evidence was meager, but he was sure of his ground because of his well-conceived and well-executed animal experiments. Professor Harrison, himself an experimentalist with wide experience, saw at once the implications of Florey’s work, and as a biologist he also envisaged the broader implications of the rivalry between plant molds and the bacteria. Harrison sent Dr. Florey at once to the Department of Agriculture, which in turn placed at his disposal the government mold laboratory at Peoria, Illinois. There, for three months, with Norman Heatley and Dr. Robert D. Coghill, the Director of the Fermentation Division of the Laboratory, he explored production methods; and by changing one step in the original Oxford procedure, they were able to increase the penicillin yield tenfold. Further improvements followed.
By the end of September, 1941, Florey was satisfied that everything was proceeding smoothly and he turned over the supervision of the therapeutic testing of penicillin to Dr. Lewis H. Weed, Chairman of the Division of Medical Sciences of the National Research Council, and through him to the Council’s Committee on Chemotherapeutic and Other Agents. Dr. Perrin Long (later Chief Consultant in Medicine in the Mediterranean Theater of Operations) was originally Chairman of this committee; in May, 1942, Dr. Long entered the Army and was succeeded by Dr. Chester Keefer of Boston, who has been personally responsible for directing the broadly conceived program of therapeutic testing of penicillin and other chemotherapeutic substances.
These were days of great scarcity of penicillin. It was in constant demand by the armed forces, and Dr. Keefer had the unenviable task of rationing the meager supply available in 1942—1943 — even to refusing frantic requests to save the lives of his friends and his friends’ children. The early distribution was handled wisely and fairly and there was no justifiable criticism of I he way in which this heavy responsibility was executed.
The production program was sponsored energetically by Dr. A. N. Richards as Chairman of the Committee on Medical Research of the Office of Scientific Research and Development (OSRD). The OSRD had come into being only three days before Dr. Florey’s arrival in this country, but the Committee on Medical Research did not become fully organized until about the time that Dr. Florey returned from Peoria. Dr. Richards, also an experimentalist of long standing, quickly saw the possibilities inherent in penicillin; he brought to the problem the weight of his influence and his intimate knowledge of the drug houses of this country. To Newton Richards and his Committee on Medical Research must be given the fullest measure of credit for the wise and forceful supervision of the production program.
The first patient in this country to receive penicillin developed under the OSRD program was the wife of a member of the Yale faculty who had had a progressive streptococcus septicemia with temperatures ranging from 104° to 106° during the four weeks of her illness. She was near death when she received her first injection of penicillin on Saturday afternoon, March 14, 1942. Within two hours her temperature had dropped to 99° and, whereas she had had an average of 200 organisms in each cubic millimeter of her blood (which had remained untouched by the sulfa drugs), within twenty-four hours of her first dose of penicillin her blood stream had become sterile. Although the penicillin available in 1942 was not yet pure, it was highly effective. The patient recovered and has been entirely free of trouble ever since.
Now, three and a half years later, thousands upon thousands of similar case histories could be recorded and the varieties of diseases which have yielded to penicillin are legion. With one notable exception, all, or nearly all, could have been predicted on the basis of Fleming’s early tests with the impure broth and Florey’s extensive animal experiments. Some organisms are resistant to penicillin and anyone infected with them cannot expect help from the drug, but fortunately the majority of the more virulent pathogenic organisms yield to penicillin. The one organism no one would have predicted as being penicillinsensitive is the spirochete of syphilis. Spirochetes are not bacteria, but belong to the protozoa of the animal kingdom; for some reason, as yet little understood, cases of syphilis, especially fresh cases, yield promptly and dramatically to penicillin, and the old and laborious thirty to sixty days’ treatment with arsenicals is now a thing of the past.
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BROADLY speaking, penicillin is effective against infections caused by organisms having an affinity for Gram’s violet stain — the so-called “Gram-positive” group of bacteria. These include many of the most virulent pathogenic organisms, such as the various pneumococci which cause pneumonia; the streptococci which are responsible for the many streptococcal infections, including scarlet fever; the staphylococci, the important group of skin organisms which are generally responsible for bone infections (osteomyelitis) and skin infections such as acne and furunculosis. The Welch bacillus, the causal agent of gas gangrene, is also Gram-positive and highly sensitive to penicillin.
A few Gram-negative organisms, such as the meningococcus, the organism of epidemic meningitis, are also sensitive to penicillin, as are the Gram-negative plague bacillus and the gonococcus of gonorrhea; but the majority of the Gram-negative organisms, such as the typhoid bacillus, the dysentery bacilli, the colon bacillus, and the tubercle bacillus, are resistant to penicillin and there is no point in wasting the valuable drug in treating these infections.
Since the spirochete of syphilis has proved highly sensitive to penicillin, it now appears that many of the other spirochetal diseases, including yaws and spirochetal jaundice, can be knocked out by penicillin. Ocular infections (which are generally caused by st reptococci or staphylococci) are remarkably responsive to penicillin, especially when locally administered, and many other local infections respond to local treatment. The ramifications of penicillin therapy thus are far beyond anything that could have been anticipated.
Sir Alexander Fleming, in recent addresses in this country, modestly stated that the real importance of his early observation may lie, not in the fact that it led Florey to develop penicillin, but in the fact that it may have a larger significance because it has focused the attention of the world upon the general problem of bactericidal agents — “antibiotics,” as they have come to be called. He thinks it improbable that the first one to be developed will be the best.
Already much time and attention have been given to other agents — such as “streptomysin,” which appears highly effective in arresting experimental tuberculosis in animals. So far, although it is receiving clinical trial, its efficacy in this and other types of infectious disease has not yet been established. But those who are investigating this problem have every hope that something effective will soon be discovered for the “captain of the men of death,” as Sir William Osler once picturesquely characterized tuberculosis.
While the discovery of penicillin cannot be attributed to the war, we can say categorically that penicillin production on the vast scale on which it has been developed in four years would never have been achieved had it not been for the pressure of war and the willingness of the large commercial concerns to make a fantastic investment on which there might be little remuneration for years to come. It is impossible to give an exact estimate of the investment in penicillin production in this country. A conservative figure would be not less than a hundred million dollars. On the experimental and clinical investigation the Committee on Medical Research has also made a large investment.
The historian of science, particularly the medical historian, feels that the public does not understand the background and sequences of scientific discovery. Could anyone contend that Newton discovered the laws of gravitation? He elucidated them in a precise manner, but he built on the shoulders of others. And when one examines the history of oxygen, Robert Boyle has almost as clear a claim in 1660 as Joseph Priestley in 1774; yet the laurels go primarily to Lavoisier since he in 1775 was able unquestionably to establish the elemental nature of respiratory gas. The story of the introduction of surgical anesthesia is another case in point. Credit for the discovery of ether anesthesia cannot be given unequivocally to any one man, but if credit is to be parceled out, the chief claim must be accorded to the man who first convinced the world that surgical anesthesia was both feasible and safe. That man was w. T. G. Morton.
If one applies this somewhat pragmatic criterion to the problem of liver and pernicious anemia, one can say with much reserve that the man who deserves primary credit is George Minot, but he would be the last to claim the discovery for himself alone, since he had built, as has every scientist who has advanced his field of learning, upon the work of others who had gone before him. There is indeed nothing more unfort unale or unpleasant in the field of human relations than priority seekers and those who, with the best of intentions, support an overzealous claimant. It is to the everlasting credit of those who have been concerned with penicillin and with other agents based on the antibiotic principle, such as Dubos’s gramicidin, that there has been little wrangling over credit and priority.
There is much still to be done with penicillin and its sister substances, both in the field of therapeutics and in the broader realm of biology. Those who enter the field should do so with clear perspective; and if they are wise, they will walk humbly, thankful for the responsibility which it has been given them to share.
5
WHEN one turns to blood and the advances that have been made in the study of this circulating tissue, one becomes acutely aware that wars, whatever their horrors, may contribute to creative human endeavor in that they stimulate work of such quality as has come out of the blood-fractionation program.
In the spring of 1940 the armed forces sought advice from the National Research Council (NC) concerning ways and means of preparing blood for use in treating the injured. Since we were not then in the war, the problem was fortunately approached from a broad biological standpoint, and the Division of Medical Sciences of the NRC developed through its Committee on Shock and Transfusions a longrange program which was financed after 1941 largely by the Committee on Medical Research of the OSRD. Contracts were entered into between various civilian groups and the OSRD, with the end in view of studying every possible way in which blood might be prepared for use in battle areas.
Since the British had had battle experience long before we did, it was natural that we should attempt to make use of their knowledge. They let it be known that, while many of their surgeons preferred whole blood to help resuscitate those who were in acute shock from injury or hemorrhage, or from both, they had experienced great difficulty in preserving whole blood for any length of time, and difficulties from incompatible blood types were so great that they had decided to look for an ideal blood substitute. Blood serum and blood plasma (that is, whole blood minus its red cells) helped to restore the blood volume in cases of shock in which there had been little antecedent hemorrhage. The British preferred serum, since it could be prepared in large amounts with less specialized equipment . There had been sufficient American pre-war experience, especially that of Dr. Max Strumia of Philadelphia, not only with the separation of plasma but also in its preparation as a dry powder which could be rehydrated by the mere addition of sterile water, to warrant its adoption as the first stable blood derivative recommended by the NRC to the armed forces.
The Army and Navy knew this much in 1940; and for better or worse, they abandoned at first any thought of shipping whole blood overseas, concentrating instead on the various blood derivatives. It will not be possible to review the details of all the OSRD contracts having to do with the blood program, but one contract will be singled out for special mention, with full realization of the fact that it is only one of the many similar contracts which have contributed so notably to this and other problems of medical research. One of the problems which appeared the most pressing among those facing the armed forces in 1940 was the preparation of a derivative of blood plasma which could be distributed in solution, would be stable under extreme conditions of heat and cold, would be ready for instant use, and would be available in as small volume as possible. Such a derivative would be most practical not only in battle areas, but particularly in ships, in landing craft, and in airplanes, where space is at a premium.
Dr. Edwin Cohn, the protein chemist of the Harvard Medical School, who in 1927 met the challenge presented in George Minot’s discovery of liver therapy by extracting and purifying liver principle for use in pernicious anemia, was asked to take up the problem of preparing in compact form the fractionated blood plasma which would have as nearly as possible the same property as whole blood in treatment of battle casualties, but which could be stored in much smaller space. To facilitate this investigation, Dr. Cohn gathered a group of investigators under his direction — a group which included clinicians, chemists, pathologists, and immunologists.2 For Edwin Cohn the problem was especially appropriate, since he had been characterizing and separating proteins from solution during the previous twenty or twenty-five years. With this rich background and with the group of investigators available for testing his various fractions, he was able to isolate the albumin of human plasma by techniques which were both practical and capable of being conducted on a large scale.
The two major protein fractions in blood plasma are the “globulins” and the “albumins.” Because albumin does not contain agglutinins, it is safer to use than the globulins, some of which may cause transfusion reactions. Furthermore, in solution it is extremely stable, so that concentrated solutions of albumin can be shipped and kept under conditions of either tropic or arctic warfare.
With the splendid coöperation of the Red Cross in organizing the blood-collecting program, and of several commercial companies in setting up huge plants under Dr. Cohn’s supervision, large quantities of human albumin were made available and sent to the ends of the earth. Subsequent investigation by Dr. Cohn and his group showed that human albumin also has a valuable place in the treatment of certain diseases which are characterized by the loss of albumin from the circulating blood. It has long been known that the blood of patients with cirrhosis of the liver is deficient in albumin. The administration of human albumin by vein to sufferers from this disorder results in a striking, although usually a temporary, improvement. The beneficial effects of albumin have been proved in certain types of kidney disease in which large amounts of albumin are lost in the urine, such as nephrosis.
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COHN and his associates thus solved the technical problem which had been put to them by the Navy, and they might have stopped there. Had they done so, there would have been no particular point in writing about the program now, for they would not have made available a series of products from plasma which have specific functions in the body and can now be used in therapy in many different conditions.
Cohn was determined to waste no part of the blood, but to find uses for all the different proteins which remained after albumin had been removed. He therefore proceeded to concentrate and purify the other fractions and to study their properties. One of the outstanding features of Dr. Cohn’s technique for the fractionation of human blood plasma was that it permitted the isolation of many different proteins from the same portion of blood, without destroying their useful and characteristic properties — a feat of chemical manipulation which had not previously been achieved. Furthermore, all his methods were applicable on a large scale, in contrast to most of the previous methods, which were useful only in obtaining a small amount of material for laboratory study. When the contracts for the study of proteins other than albumin were granted, Dr. Cohn and his group soon made available in large quantities numerous other proteins of the blood, including globulins and the proteins concerned with the blood’s clotting mechanism.
One of the globulins, designated by the Greek letter gamma, — that is, the “gamma-globulin,” — is a concentrate of protein concerned with immunity. Since a large percentage of the people donating blood to the Red Cross program had at some previous time had measles, this fraction was tried clinically by Dr. Joseph Stokes, Jr., of Philadelphia, and Dr. Charles Janeway of Boston, at the suggestion of Dr. Elliott Robinson, to see whether it would prevent measles in man, and it did. Instead of turning the globulins down the sink as unwanted, Dr. Cohn and his collaborators were thus able to direct the preparation of a quantity sufficient to prevent measles in the whole United States standing army for many years.
It was next found by Dr. Stokes that the gammaglobulins were highly effective in the prevention of infectious jaundice, of which many cases developed in the armed forces, particularly in the Mediterranean theater. It has been possible to develop sera which are effective against certain other infections by fractionating the blood of people who have recently recovered from these diseases.
Another globulin which has been isolated in large quantities is that responsible for the specific blood type in all individuals—that is, whether one is type O, A, B, or AB. The blood as collected by the Red Cross consists of a mixture of all types and therefore the blood-typing globulin from the pool is not useful. However, if the blood of different types is separated before fractionation, one particular fraction will contain only the globulins which are responsible for characterizing a particular blood type. Because other fractions of the blood have been removed and the blood-typing globulin has been concentrated in one small part, the resulting material is thirty times as effective as the original plasma when used to determine an unknown blood type. Since the blood type must be determined before a transfusion of whole blood is given, the use of especially selected plasma or of this highly concentrated globulin fraction facilitates transfusion in the armed forces as well as among civilians.
There are several other types of globulins in the circulating blood, many of which have been isolated by Dr. Cohn and his collaborators and are now being studied to determine whether or not they can be put to particular clinical uses. Besides the globulins concerned with blood typing and those concerned with immunity, there are globulins which are hormones and enzymes, those concerned with the transport of fat, and those concerned with the coagulation of the blood.
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PERHAPS the most dramatic achievement of the fractionation program has been the isolation in useful form of fibrinogen and thrombin, proteins responsible for the coagulation of the blood. For the blood to clot, fibrinogen and thrombin unite to form fibrin. When solutions of fibrinogen and thrombin are mixed they form a glue-like substance which has been found useful in certain phases of surgery, especially in holding skin grafts in place. If the mixture of fibrinogen and thrombin is made under other conditions, the characteristics of the resulting fibrin may be made to vary greatly in mechanical properties.
One product of fibrinogen and thrombin under particular conditions is a dry foam which, when moistened, has properties similar to those of a moist cotton pledget such as a surgeon uses when attempting to stop tissue hemorrhages. If such a foam is moistened in thrombin solution, it will act as an agent which will arrest local bleeding in most dramatic fashion. Indeed, “fibrin foam" and thrombin seems to be the answer to the surgeon’s prayer, for the history of surgery has been largely concerned with ways and means of dealing with hemorrhage. Before the time of Ambroise Paré in 1545, military surgeons arrested hemorrhage by plunging the bleeding member into boiling oil, a procedure deemed preferable to the cautery which had been used since prehistoric times. Paré introduced the ligature. When a large vessel bled, it was tied instead of seared. After Paré’s time there was, curiously enough, little advance in methods of controlling bleeding, save for certain improvements in the tourniquet and in hemostat clamps, until Sir Victor Horsley, the British neurosurgeon, found that pieces of muscle, when they were applied to a bleeding point, tended to promote coagulation.
Harvey Cushing confirmed this discovery, and a year later, in 1910, introduced the silver clip. He also made wise use of the blood-vessel constrictor, adrenalin, to stop bleeding. Later he introduced, with his colleague Bo vie of Harvard, certain electrosurgical methods for arresting bleeding when vascular brain tumors were to be removed; they developed highfrequency currents which would coagulate and cut tissue without unduly heating it. In fibrin foam and thrombin, on the other hand, we have a physiologically normal method of inducing coagulation. The met hod of preparation was elaborated in the Harvard Laboratory by a young Navy lieutenant, E. A. Bering, Jr. Quite fittingly, the announcement of the clinical use of this important new agent was made by Franc Ingraham and Orville Bailey in the first number of the Journal of Neurosurgery, founded by the Harvey Cushing Society in January, 1944.
Not only is fibrin foam with thrombin useful in surgical procedures on patients with normal bloodclotting mechanism, but it has also proved effective in treatment of wounds of patients having hemophilia. The hereditary transmission of this disease and the difficulty in controlling bleeding have left a mark in European history out of all proportion to the frequency of the disease. Its occurrence in the male members of the royal families, particularly those of Spain and Russia, has necessitated a protection from injury so meticulous that successful leadership could hardly be expected. The most trifling injury or the most inconsequential operation results in bleeding which ordinary hemostatic agents are completely inadequate to control. Although fibrin foam and thrombin do not alter the inherent deficiency of another globulin in patients with hemophilia, the application of this material makes it possible to control local hemorrhage promptly and completely. It must be recognized, however, that a second injury will again require treatment with the hemostatic material, since fibrin foam with thrombin does nothing to alter the basic mechanism at fault.
It is remarkable that changes in the conditions under which fibrinogen and thrombin solutions are mixed can alter the character of the product to so great an extent . With proper conditions it is possible to produce a material varying greatly in appearance, character, and use from the same proteins employed in making fibrin foam.
One such material, developed by John Ferry and his associates under Cohn’s OSRD contract, has been designated “ fibrin film.” ’Phis, when wet, is a sheet of translucent, elastic material somewhat resembling in appearance latex rubber. It is, however, made entirely from human proteins and causes little reaction when left in the tissues. It does not act as a hemostatic agent, but has been prepared for use in the treatment of head wounds in which the coverings of the brain have been destroyed. Very serious results are to be expected when the brain is left uncovered following such injury. The experience of Ingraham and Bailey with fibrin film indicates that the unfortunate results following such injuries can be greatly reduced by the use of fibrin film as a substitute for the normal brain covering which has been destroyed. Not only is fibrin film of value in treating head injuries, but it also has a large place in the surgery of brain tumors and certain other conditions of civil practice.
Thus, from human fibrinogen and thrombin two products of widely different character and of different uses have been prepared by altering slightly the conditions under which they are allowed to mix. This is an example of what the chemist can accomplish in preparing materials suitable for special medical requirements if he is working in close coöperation with experts in animal experimentation and in clinical and surgical procedures. The fundamental chemical work has to be done by highly qualified specialists in order to prepare the new materials to be studied. These are then tested in animals, and if the tests are successful, clinical trial must be undertaken in carefully selected cases.
It is of great importance to judge with suitable wisdom the precise moment when more extended clinical trial and final release of the new products may be permitted, because great harm might result if the conditions under which the materials are prepared deviate even slightly from those most favorable. It is easy to see that animal experimentation plays an essential role in this sequence. The results may either establish the safety of an entirely new product or may prevent the use of a material wholly unsuited to human medicine and surgery.
The Harvard group on plasma fractionation is a classic example of the speed and efficiency with which a group of specialists in a large number of entirely different fields may produce and establish the use and safety of new products in medicine and surgery. Such groups have proved their usefulness over and over again under pressure of wartime conditions, and it is only logical to expect similar results when the attention of the groups can be turned to the problems of peace. It is clear, however, that such groups cannot function any better than an individual scientist when the problem on which they work or the manner in which it is undertaken or the time for publication of their studies is determined by any outside agencies. The results reflect great credit upon American scientists and particularly on the judgment of those in the Army and Navy and the Committee on Medical Research who sponsored Dr. Cohn without curtailing his independence.
What lessons have been learned from our wartime medical research? In the first place, we can recall only with chagrin the fact that in the spring of 1940, when our peril became clear, we were as pitifully unprepared in medicine as we were in the instruments of war. For over a year, an isolationist Congress made it difficult to obtain funds and to conduct essential research. The National Defense Research Committee (NDRC), through the fortunate circumstance of having persuasive scientific leaders, Vannevar Bush and James B. Conant, in the right places at the right time, received an independent appropriation of ten million dollars in June, 1940, but practically nothing was designated for medical research until the OSRD was created by executive order on June 28, 1941. During the first year, the various committees of the Division of Medical Sciences at the National Research Council, which had been called into being at the request of the Surgeons General of the Army, Navy, and Public Health Service, were virtually without funds to operate.
It is imperative that such a situation never be permitted to occur again if we have any regard whatsoever for our national security. The people of the United States as a result of the war have become “health conscious,” and conscious also of the importance of medical research for our nation’s welfare. There is every indication that the public will insist upon improved medical service and health protection, and will demand that the government foster research essential for the health and security of the nation.
We shall show our wisdom in the ways and means chosen for the support of our post-war medical research. We must decide whether it is to be placed in the hands of bureaucratic Federal agencies that will be subject to political influence, or whether it will be set up under the supervision of recognized scientific bodies which are independent of political control.
- He did not succeed in purifying the lysozyme, however, but it was ultimately crystallized by his associate, Houghton Roberts, in 1937.↩
- The chemists were largely those previously associated with him, and each of them has become an expert regarding one or another of the diverse groups of proteins which constitute plasma. Thus the expert on the proteins concerned in blood coagulation is John T. Edsall; on the globulins of importance in immunity, John L. Oncley; and on the albumin separated for use in shock and hypoproteinemia, Laurence E. Strong and Walter L. Hughes, Jr. George Scatchard of the Research Laboratory of Physical Chemistry at the Massachusetts Institute of Technology joined the group, as did Hubert Vickery of New Haven and other investigators from other institutions. The testing of each fraction demanded not only chemical but also animal experimentation to prove the safety of the product before clinical investigation could begin. Here Dr. Cohn’s day-by-day collaborators included among the clinicians the late Soma Weiss, Charles A. Janeway, S. Howard Armstrong, Jr,; as surgeon, Franc D. Ingraham, as well as a group of young Navy lieutenants assigned to the Plasma Fractionation Laboratory; as immunologist, John Enders; and as pathologist, Orville T. Bailey. Only when this group, working in close coöperation, were satisfied of the safety and value of a product was its wider testing begun under other OSRD contracts in order to obtain independent evidence, on the basis of which an NRC committee could recommend its adoption to the armed forces.↩