Defensive Ferments of the Animal Organism

Front matter

DEFENSIVE FERMENTS OF THE ANIMAL ORGANISM

DEFENSIVE FERMENTS OF THE ANIMAL ORGANISM

against substances out of harmony with the body, the blood-plasma and the cells; their demonstration, and their diagnostic significance for testing the functions of different organs

Preface to the English Edition

Preface to the English Edition.

It is more than three years since Abderhalden first published his results in regard to the sero-diagnosis of pregnancy. In the course of his general studies on the nature and properties of the ferments in the blood, and on their relations to metabolism, he came across an instance of their specific action, which suggested the possibility of diagnosing the condition of pregnancy by their means. And it was on the basis of the same methods as had been employed years before by himself and his followers in their preliminary theoretical investigations, that he was led to the great discovery of the demonstration of specific ferments in the blood-serum; that is to say, by the use of the optical method and of the dialysation process.

In view of the possibility of the practical application, in medicine, of these new methods of research, for the purpose of making differential diagnoses and of testing the functions of organs in various diseases, they have been taken up by many members of the medical profession. They were first employed by the gynæcologist; but there is now hardly any branch of medicine left in which the application of these new methods has not been attempted, and in the course of time interest in these new weapons of research has rapidly increased. Much has been done, for the popularization of these methods, by the kindness which has been shown by Abderhalden and his assistants to all those who were willing to acquaint themselves with the rather complicated technique involved in them. He found room in his institute for all who wanted to come; every written inquiry was promptly answered; and reagents, such as placenta-albumen and peptone, in the preparation of which some difficulty is met with, were freely supplied from his laboratory.

The conception of "harmony and disharmony" has been employed by us, in order to represent the meaning we attach to Abderhalden's terms "fremd" and "eigen." These phrases, though they have been translated literally by some, do not seem to us to be amenable to direct translation.

In presenting this translation of the latest edition of Abderhalden's work on defensive ferments, I have been inspired by the hope of being able to excite or further, in regard to this important line of modern research, the interest of many to whom the German text may be inaccessible.

J. O. Gavronsky.

7, Cambridge Terrace, Regent's Park. February 23, 1914.

Preface to the Third Edition

Preface to the Third Edition.

It took less than three months for the Second Edition to be exhausted, a pleasing sign that this new field of research has excited much interest. The number of works which have been completed on the basis of the principles there laid down, and of the methods there disclosed, exceeds one hundred and twenty! Every week brings forth new works. I am not sure whether that ought to give me entirely unbroken satisfaction. The fundamental works, which have arrived at a definite conclusion in regard to the elaboration of the dialysation process and of the optical method, have been produced during the last twelve years or so. The "theoretical" part, which pointed to the possibility of a sero-diagnosis of the functions of organs, was practically established six years ago. Experiments on animals were started on a large scale, so as to allow for all possibilities. Over and over again doubts cropped up which had to be settled. The astonishing result was found that, in disturbances of certain organs, only their albuminous constituents suffer decomposition. These discoveries were not made public, and only those results, which were established in investigations on pregnancy, were published. Pregnancy is a condition which allows of no misinterpretation. In almost every case the clinical diagnosis can be compared, with absolute certainty, with the result of the serological diagnosis. The actual diagnosis either corresponds with the former, or it does not. These clear conditions, however, are not presented by the other morbid processes. A certain disease may be accompanied by all kinds of other disturbances of the functions of the organ. Very seldom are we faced with the presence of "pure" disease. Therefore, we are bound to conclude that only the worker in a hospital is in a position to judge, to what extent serological investigations can be applied for testing the functions of an organ. In this case two aims have to be distinguished. The serological diagnosis can, in many cases, widen our understanding of the disturbances occurring in a given disease. We gain an insight into long suspected functional troubles of certain organs, or discover that others, which had never been thought of, regularly produce disturbances in a certain disease. It is an entirely different question to ask whether the serological diagnosis of an organ can be applied to differential diagnosis, i.e., whether we are entitled to accord a preference to this, as against any other, method.

Many years may be required before the question of the practical value of the methods worked out can be decided for each separate case. Every research, which has not been carried out with absolutely unobjectionable technique, delays our arrival at a clear appreciation of the suitability of the methods. There are practically no methods which, on first acquaintance, will lead anyone to good results. Often weeks have to be spent in preliminary studies, before facts are acquired which entitle us to apply the required methods to certain questions. No conscientious student would publish these preliminary studies, but would treat them as exercises. Owing to a very extensive experience of my own, I cannot deny that many preliminary studies of this kind have been published. It is only work that is deliberate, and that is based on a complete command of methods, that can lead to satisfactory results. It is, besides, the duty of the clinical worker to thoroughly study each case, and to follow it out to the end.

As yet, it is too early to criticize the works that have appeared, and I have contented myself merely with summarizing such as have come to my notice. Then the results of recent experimental researches have been referred to. The question of the specificity of the substrates is discussed, and, finally, in the description of the technique, some recent experiences have been considered.

Emil Abderhalden.

November, 1913.

Preface to the Second Edition

Preface to the Second Edition.

Though scarcely a year has elapsed since the publication of the First Edition, yet it has been possible to widen the scope of the Second in many points. Since then, numerous investigations in different fields have been either begun or completed. The most important results of these investigations are given at the end of this little volume.

The term "protective ferment" has been dropped, because it may easily convey the idea that these ferments, which are called into action by the presence of substances out of harmony with the plasma, are unconditionally protective. The term "defensive ferment" will more readily suggest the notion, that the animal organism attempts to defend itself. By means of decomposition it often deprives disharmonious substances of their specific character, but in many cases the defensive ferments form decomposition stages which are more dangerous than the substrates they attack.

May this new edition find the same friendly welcome as the first.

Emil Abderhalden.

Halle a/S., June 15, 1913.

Preface to the First Edition

Preface to the First Edition.

In my text-book on Physiological Chemistry, published in 1906, I made an attempt to harmonize the defensive measures, adopted by the animal organism against products generated by cells out of harmony with the body, with the metabolic processes of the individual cells of the body. I was of the opinion that, when an invasion takes place of cells which are out of harmony with the body, the blood or plasma, and the cells, the cells of the body respond with counter-measures which are not entirely new to the cells of the particular organ or of the blood; on the contrary, I tried to bring the whole question of the so-called reactions of immunity into close line with processes that are normal, and consequently familiar, to the cells. From the point of view stated in the above-mentioned text-book, I attacked experimentally the problem of the method of defence, used by the animal organism, against the invasion of substances out of harmony with the body, the blood plasma, and the cells. In the first place I studied the question whether normal blood plasma contains definite ferments; and, in the second place, whether the introduction of disharmonious substances is followed by the appearance of ferments which were not there before. I found, in fact, that, after the introduction of substances out of harmony with the blood plasma, ferments appeared which are capable of transforming these products, and of depriving them thus of their specific character. These facts established beyond doubt one means of defence possessed by the animal organism against the invasion of disharmonious substances.

My thoughts then turned at once to the relation of these facts to immunity, and especially also to anaphylaxy, and I undertook experiments to decide the question as to whether the animal organism develops any ferments of a specific nature against substances produced by micro-organisms. And I was particularly interested in the question whether the stages that arise, in any given case, during the decomposition of a particular substrate vary with the species of the invading cell, and whether this may not give us the explanation of many phenomena that appear in the course of certain infections. Finally, I was able to demonstrate that, during pregnancy also, the organism defends itself, by means of ferments, against certain constituents which are passed into the blood, most probably from the cells of the chorionic villi, and which, though in harmony with the species, are out of harmony with the plasma. This observation renders possible a diagnosis of pregnancy.

The above statements have a bearing on a great number of particular problems connected with immunity, which still await solution; nor is there any doubt that many well-ascertained facts are closely connected with the results of our researches. Even now it would be tempting to select suitable instances from the mass of my particular observations, with a view to giving a more general signification to the views I have formulated on the means of defence possessed by the organism against the invasion of substances or cells that are out of harmony with the body. For the time being I have refrained from doing so, as the mere enumeration of closely related observations, quite apart from a discussion of all the hypotheses put forward, would enormously increase the scope of this little volume, and incidentally would interfere with a clear insight into our subject.

Again, it is very difficult, for those not actually engaged in research work on immunity, to keep in touch with all the communications made at different times concerning ideas and theories that are constantly changing, and above all to find a sure footing amongst the somewhat pleonastic terminology and nomenclature employed. Theory and actual fact form, in this field of research, a closely interwoven net of conceptions; so much so, that only those, who have already acquired, by actual corroboration, a thorough knowledge of all the problems connected with the subject, are able to trace sharp limits between hypotheses and facts. For these reasons I have limited myself to making mention of those works which either are closely connected with my own researches, or else will be of special service to the reader, in that the full lists of references they contain will be a guide to further study in this field of research. This limitation alone has enabled me to present a picture—which, I hope, is quite clear—of the development of my own investigations, and to show how I arrived at the doctrine of the active part played by ferments in connection with disharmonious substances.

The comprehensive survey, which I now present, has resulted from the fact that many problems have been so far advanced, recently, by means of experimental work, that it seemed advisable to take stock of the observations that lie stored in numerous publications. And, on the other hand, I find that the further study of particular problems can be carried on only in institutions supplying means and apparatus which I cannot command. One man by himself is able in certain problems to reach only a certain point. He takes over, as it were, an edifice which has been built up to a certain height from all possible sides. He tests the scaffolding—the existing working theories—to see whether it will last any longer, or whether it must be replaced; and, more important than that, decides whether the structure itself is perfectly sound. He then builds further, but in most cases makes only a tiny addition. It is very easy for a single observer to lose a clear view of the whole, through using too complicated a scaffolding. Others follow; they test the solidity of the structure, they move the misplaced bricks into their correct position, and give a finishing touch to the parts that are insufficiently trimmed. Each new workman brings new tools, new ideas, and his own extensive experience with him, and tackles the whole structure from different points of view. Then the scaffolding is removed, and a mighty building appears, which scarcely gives any idea how diverse were the plans on which it was founded. So, too, this contribution to our knowledge of the functions of the cells may be considered only as an attempt to adjust a new stone in the already existing structure, and to construct a scaffold from which further progress may be made.

In conclusion, may I be permitted to express my heartiest thanks to my collaborators, whose untiring energy has made it possible to accomplish so many single experiments in such a relatively short time, and to work out different problems from various standpoints at the same time.

Emil Abderhalden.

Halle a/S., April 15, 1912.

Section 1

Defensive Ferments of the Animal Organism.

The question has frequently been raised, whether unicellular organisms exhibit simpler processes, in their general organization and metabolism, than do organisms composed of numerous cells. A priori, it is conceivable that organisms of a morphologically simpler construction are composed of simpler combinations, and that their metabolic processes follow a simpler path, than is the case in those forms of life in which the body is built up by the co-operation of different cells. But all our experience, hitherto, has proved, that even those cells which are constructed on a simple plan morphologically do, when studied from a purely chemical point of view, show exceedingly complicated relations. Indeed, the study of the processes of metabolism in unicellular forms of life is a study all the more difficult, in comparison with that of more complicated organisms, in that, in the former, it is so difficult to separate the actually absorbed materials from the metabolic by-products, and these again from the secretory or excretory products. Absorption and secretion merge in each other. The higher we climb in the scale of organization, particularly in the animal kingdom, the more do we meet with cells which are entrusted with special functions. For instance, we find cells which receive matter from the exterior. Others transform particular compounds into products of a special nature. Others, again, have the function of carrying the final products of metabolism to definite points for excretion.

A unicellular organism stands constantly in relation with numerous substances of the outer world, which differ from place to place and from time to time.. Some of these it makes use of as nutriment. Others, on the contrary, are entirely useless to the cell in question, while many would cause considerable harm, if allowed to penetrate its wall cells. To these substances the single cell does not yield itself helplessly, but has at its disposal various arrangements for its own defence. It has, in the first place, a cell wall which is impermeable by many substances. Further, the cell, by means of different processes, is capable of altering substances, which may in any way be injurious to it, in such a way that the active group is rendered harmless. Often a simple hydrolytic decomposition is sufficient to deprive the compli substance of its specific properties. The disharmonious product is decomposed into indifferent by-products which are harmless to the cell. More energetic means are often employed, and the material is oxidized or reduced according to the special needs of the cell. Even in these simple forms of life it is probable that many substances are rendered harmless by combining to form fresh compounds, just as, in the metabolism of a more complicated organism, rearrangements of different kinds are undergone which alter such materials as are undesirable, so that they may be excreted in this form out of the body. Very often a given substance is incapable of combination, in which case it must first be so transformed by special processes as to be susceptible to combination. We thus see how the cells of the body oxidize, reduce, or decompose, until a product is reached that is capable of combination. There is no reason to doubt that unicellular organisms have similar means of defence at their disposal, but they are not so easily traced, owing to the fact that it is more difficult to add certain substances to a single cell, without damaging it, than it is in the case of a more complicated organism. The latter are able to modify profoundly the action of substances introduced by the mouth, owing to the fact that they are gradually absorbed. Further, these substances are considerably diluted in the lymph and the blood. Finally, they may be easily withdrawn from the body before they have had any opportunity of penetrating into the interior of the cells.

As a principal defence a single cell always has the cell wall, with its characteristic construction and its specific physical properties. Besides this, there is no doubt that ferments play a considerable role. They allow the cell to make a choice from amongst the substances which are continually acting upon it. These ferments, as Emil Fischer (Lit. 6) has proved from his exact researches on the subject, are directed in a specific manner against definite substrates. Only those substances, which are capable of being decomposed by the cell into simpler groups, are in general found to be of use to it. Throughout, our positive knowledge has led us to the conclusion that cells supply their vital needs only from the simplest units of the nutritive material, and that they probably never break down such complicated substances as fats, polysaccharides, and proteins, directly into their final metabolic products. Even the simplest units are not at once completely broken up. The cell works in stages. First of all it splits up large molecules into smaller particles, and so sets free from the rest one fraction of the entire energic contents of the original material, until finally—at least, with carbohydrates and fats—the whole amount of contained energy is released. The cell regulates its own metabolism down to the minutest details. In the proper preparation of the material to be decomposed, and in the gradual liberation of the amount of energy required, lies the real importance of those substances formed by the cell, which we at present comprise under the name of ferments.

The ferments have yet another value for the cell, in that they help it to regulate its own structure. Not every product which is taken up by the cell passes into its structure. Sometimes the decomposition must be carried on further; in other cases the particles must be synthesized suitably for the production of the necessary structural unit; after which it sets about the recombination of all the numerous constructive units, so as to form the complicated characteristic structure of the cell. Though we do not yet know the precise nature of the ferments, yet their specific activities, and their great importance in regard to cell metabolism and cell structure, are well known.

Without energy no cell can do work or produce heat, and it is in energic metabolism that we find a true picture of the functions of the cell. How the cell procures the required energy, in what manner it makes use of it, and so on, we can learn only by an accurate and possibly exhaustive study of the finer metabolic processes that go on in the cell. In these processes the so-called ferments play the most important rôle. With their aid we have succeeded in following up, outside the cell, processes which seemed to be exclusive properties of the cell. The more these experiments are extended, the more we meet with observations which show that we have been in the habit of picturing far too schematically the processes within the cell body. Thus, for instance, the simply formulated process of the fermentation of grape sugar into alcohol and carbonic acid gas—C6H12O6 = 2C2H5OH + 2CO2—has been found to be a most complicated process. A whole chain of reactions takes place, before the grape sugar is finally converted into alcohol and carbonic acid gas. There are many more intermediate stages present than were ever suspected. It will be an important duty of future research to ascertain what importance alcoholic fermentation, in all its stages, has for the yeast cell. We are indebted to recent researches, in which Knoop, Neubauer, Friedmann, Embden, Dakin, Schittenhelm, Jones and others have taken a prominent part, for a knowledge of numerous intermediate stages in the decomposition of the amino-acids, of grape sugar, of purin bases, &c. Every time we demonstrate fresh intermediate links in the decomposition of certain compounds we get a deeper insight into the working of the metabolic processes of the cells, and obtain important clues as to the means by which the cells of the animal organism produce, from compounds of a definite kind, substances that belong to a different group. We may mention here, for instance, the conversion of amino-acids into grape sugar, and of carbohydrates into fats.

Some of the unicellular forms of life, and some organisms consisting of a few groups of cells, are, at least in part, equipped with agents (ferments) which are not so precisely directed against certain substrates as the ferments of the higher species, such as plants and animals. While the ferments of the latter, so far as we know, principally decompose substrates consisting of units which are found in the cell-constituents that constantly recur in Nature, cases have been observed amongst the lower organisms (i.e., morphologically lower) where the latter split up compounds, which have been prepared in the laboratory from units which are not known to exist in a free state in Nature. Owing to this wider independence these organisms are assured of better conditions of existence. These cells can live where others, being unable to secure the energic contents of the material supplied to them, and being also unable to form from this substrate the elements required for their bodies, are bound to perish through lack of nourishment. In this way a cell dies, though it be plentifully surrounded by a material rich in energy, which, however, cannot be used because it lacks the proper form—both structural and configurative. It does not suit the organization of the cell. There is an abundance of oxygen at its disposal, but the latter cannot find any point of attack; and so the necessary preparation is wanting.

Some of the substances cannot be absorbed by the cell, simply because they are physically too coarse to penetrate through the cell wall. Such is the case with many colloidal substances, which must be first decomposed into simpler groups before they can pass into the interior of the cell. In these cases the presence of ferments is essential, and they have to be of such a kind as to be capable of decomposing the complicated molecules into a form which may easily penetrate through the cell wall. Often, however, such conditions may suffice as enable the coarse complex substance to be simply broken up into finer particles, which may be ingested in this form by the cell, without any molecular decomposition being necessary. Further decomposition takes place during absorption or, even later, at a suitable point within the cell.

Even a unicellular organism does not enter into intimate relations with substances which have not previously been remodelled. This remodelling generally takes place in such a manner that the substrate is decomposed into simpler indifferent constituents, after which the cell builds from the base upwards. In many cases this rebuilding is unnecessary. Such is the case when the cell only requires the energy contained in the absorbed substance. As soon, however, as substances are required as vital units of the cell, then they have to be adapted to the whole structural plan in all its minutest details. This is also the case when secretory substances, having a characteristic structure and a specific action, are to be formed.

Ye know of unicellular organisms which produce their body substance from very simple elements indeed. Thus, we know of organisms which produce their cell plasma from carbonates, nitrates, water, and salts. Others can draw their nitrogenous supply from any substance which will supply them with ammonia. Others, again, make use of the free nitrogen of the air. There are, however, even amongst unicellular organisms, some that are very fastidious and will only thrive in the presence of certain peptones. Others even require certain forms of protein from which to obtain their derivatives.

An exhaustive study of the sources of nitrogen necessary for each separate organism, paying due attention to other nutritious materials and conditions, will no doubt lead to exact methods for the culture of separate cells in the laboratory. Following this line of inquiry we could surround certain microorganisms with peptones whose composition we are familiar with, and so acquire a deeper insight into the processes of their metabolism. Even the mode of decomposition of the substrate, and of the intermediate stages, may furnish some important hints as to the specific functions of the cell and, in many cases, allow us to recognize particular organisms. We shall, by this means, understand why certain germs thrive upon certain media, while on any other substrate they either cease to grow or perish entirely.

It will also be possible to determine exactly, which of the decomposites and by-products formed from the culture medium produce harmful effects.

There is no doubt that, in the organic world, certain species prepare the soil for others, and in this way one organism acts as a pioneer to the others. It is a most interesting task to follow up this co-operation of different living beings in all its details. To a certain degree we have, in the co-operation of single cells, a forecast of the division of labour found amongst the organs of the higher forms of life. In the former case we have the cells as yet free, while in the latter they are combined into tissues. From this point of view we may look upon the symbiosis of heterogeneous species of cells as a first experiment in the building up of a cell state. The single cells are still independent and their duties multifarious. There is no strong bond uniting the organisms into any one "organ," and yet they depend upon each other for mutual support. Unicellular beings begin to organize themselves into combinations. Another step further and we arrive at cell complexes having definite functions, which we call organs. But even the most developed organisms, both of the animal and plant worlds, have relations with cells which stand outside the common organization. By means of micro-organisms the plant gains access to otherwise inaccessible sources of nitrogen, while by means of bacteria the animals make use of the important carbohydrate, cellulose. The bacteria convert the latter, within the intestines, into products which can be further decomposed by the ferments secreted by the glands.

In those organisms in which division of labour has been instituted amongst the cells, and particularly in those in which definite cells have closed in to form an alimentary canal, these are the only cells which are in communication with the outer world. They alone know, so to speak, what food is ingested. Even these have no direct relation with the ingested material, seeing that the latter, before being taken up by the cells of the gut, has been subjected to the action of the ferments poured into the alimentary canal, and been disintegrated into simpler and indifferent particles. All nutriment of a composite nature is dissolved in stages, until finally products of decomposition result which no longer exhibit any special characters.

Generally speaking, food supplies the material for the building up of the cell, and we must remember that we are dealing with the complicated tissues of animals and plants. Each cell has a specific fabric of its own, which is dependent on the nature of its separate units, and on the manner in which they combine together. We must not look upon this from a purely chemical point of view alone, but should pay attention to its physical aspects as well. The sum of the properties resulting from the special structure of the cell conditions its special functions. When such cells, with their specific structure and functions, are taken in by an individual organism, the latter can at first do nothing with the material supplied. The special character of the different products that make up the particular cells must first be destroyed. Unit must be separated from unit, so as to leave only a mixture of simple compounds, from the elements of which the body cells may construct their own material, or else renew their supply of energy. In the latter case, too, as has been mentioned before, a preparatory decom- position (a kind of adaptation to the cell) is necessary.