Protista

“ Haeckel has also made observations upon those lowest forms of life, which, being simply protoplasm without the slightest trace of organization, not even possessing a nucleus, form his division Protista, occupying the no-man's-land between the animal and vegetable kingdoms. ”

“ Purposes of Proteids.—The chief purpose of proteids in the body is to rebuild the tissues. Not only do they supply all of the main elements in the tissues, but they are of such a nature chemically that they are readily built into the protoplasm. They are absolutely essential to life, no other nutrients being able to take their place. An animal deprived of them exhausts the proteids in its body and then dies. In addition to rebuilding the tissues, proteids may also be oxidized to supply the body with energy. ”

“ The proteids of the tissues serve the double purpose of forming a working part of the cell protoplasm, and of supplying reserve food material. That they are available for supplying energy, and are properly regarded as storage material, is shown by the rapid loss of proteid in starving animals. When the proteids are eaten in excess of the body's need for rebuilding the tissues, they are supposed to be broken up in such a manner as to form glycogen and fat, which may then be stored in ways already described. ”

“ Now, as the proteid part of its molecule is the most important constituent of living matter, it is evident that proteid food is an absolute necessity. If our diet contained no proteids, the tissues of the body would gradually waste away, and death from starvation would result. All the food-stuffs are necessary in one way or another to the preservation of perfect health, but proteids, together with a certain proportion of water and inorganic salts, are absolutely necessary for the bare maintenance of animal life—that is, for the formation and preservation of living protoplasm. ”

“ Let us say a word or two on their nature and peculiarities.
Far down among the lowest forms of animal life with which we are acquainted, is the strange organism known as the Proteus (Amœ ba diffluens) ; it is nothing more than a small lump of jelly without integument, but endowed with the capability of moving and eating, if eating it may be called. Special organs for this or any other function it has none, but the whole of the gelatinous body covers and encloses within itself any atom capable of affording nutrition, and becomes mouth and stomach both, when occasion requires. ”

“ Proteids are confessedly among the most complex bodies the physiologist has to deal with, while at the same time they are perhaps the most important, not only in view of their wide-spread distribution through animal and vegetable tissues, but because of the prominent part they take in the nutrition of the body. The more our knowledge is broadened concerning these varied substances, the more we are impressed with their complexity, and at the same time with the necessity for a more accurate study of both their composition and constitution. ”

“ According to physiological authority which we must, for the moment, accept, proteid is a vitally-necessary material and we cannot afford to waste it. Our life depends upon proteid to replace the waste of muscular tissue which occurs [Pg 4] with every movement, but when even good proteid is found by the mouth to be in a form that is too refractory for the teeth to handle, it is poor policy to send it on to the toothless stomach and intestines for the accomplishment of the reduction. If the mouth cannot handle what its guardian senses don't like, it can spit it out and get rid of it immediately ”

“ With the time at my disposal, it would be impossible to discuss all the chemico-vital problems which the physiologists of the present day are attempting to solve, but there is one subject at which many of them are laboring which seems to me to be of supreme importance—I mean the chemical constitution of proteid or albuminous substances. Proteids are produced only in the living laboratory of plants and animals; proteid metabolism is the main chemical attribute of a living thing; proteid matter is the all-important material present in protoplasm. ”

“ Worthy of special notice is the fact that cell protoplasm is essentially proteid in nature; water and proteid make up the larger part of its substance, to which are added small proportions of carbohydrate, fat, and mineral matter. Proteid is the basis of cell protoplasm; it is the chemical nucleus of living matter, and owing to the large size of its molecule, with its large number of contained atoms, is capable of many combinations and many alterations. ”

“ It is true that, with the limitations of our present knowledge, it is difficult to see why if digestive proteolysis has for its sole object the conversion of the proteid foods into forms suitable for absorption there should be any considerable breaking down of proteid beyond the proteose or peptone stage, since the latter bodies would seem to be most easily adaptable for transformation into the proteids of blood, lymph and tissue. ”

“ We also know definitely just what use the body makes of these various substances. The Proteid is the up-builder of tissue, the essential foodstuff without which life cannot exist. If we compare the human body to an engine, as nearly all physiologists seem bound to do, we may say that Proteid is like the brass, or other metal, of which the structure is composed. The various Carbohydrates and the [Pg 99] Fats are the fuels from which are derived the energy which animates and operates the mechanism. ”

“ The one factor above all others that tends to increase the extent of proteid katabolism is the amount of proteid food ingested. Increase in the amount of the albuminous foodstuffs is at once, or speedily, followed by an increase in the output of nitrogenous waste products, the latter constituting a good measure of the extent of proteid metabolism going on in the body. We have been taught to believe that the healthy adult under ordinary conditions of life needs for the maintenance of health, strength, bodily and mental vigor, about 118 grams of proteid food daily. ”

“ The oxidation or burning up of proteid, however, is never complete. There is always a certain amount of unburnable substance left behind from the processes of metabolism, which the liver and kidneys of the body have to dispose of. If only as much proteid as is needed by the body for the upbuilding of its tissue, and the repair of waste, is taken, the body can very readily handle it; but an excess of proteid is highly disadvantageous. Professor Chittenden, in his great work, “The Nutrition of Man,” has set forth in elaborate detail the process of the assimilation of proteid. ”

“ Assuming for the moment the correctness of this theory, we see at a glance that all disruption of proteid matter in the body must be preceded by the upbuilding of the proteid into living protoplasm. There can be no destruction of proteid until the latter has been raised to the high plane of living matter. ”

“ Taking into account all of the circumstances attending the circulation of the blood through the abdominal organs, especially the rate of flow, and remembering the great increase in the number of leucocytes contained in the blood during the several hours attending digestive proteolysis, it is plain that a comparatively large amount of proteid matter must be transferred from the intestine to the blood in the bodies of the white corpuscles so abundantly produced in the lymph glands, etc., during proteid digestion. ”

“ And if we go a step beyond this and suppose that in the formation of true tissue proteid or the living protoplasm of the cell, certain of these end-products of proteid decomposition are absolutely indispensable, we can easily picture for ourselves a dearth of such building stones in the long-continued use of a diet which lacks that particular proteid from which the necessary building stones can be split off in adequate number. ”

“ Just as the so-called secreting cells of the tubuli uriniferi may lose for a time their power to pick out from the blood material destined for the urine, being clogged or exhausted by continued effort, so the epithelial cells of the intestine, which play such an important part in the absorption of proteid matters from the alimentary tract, may, in the presence of an excess of proteid matter, become temporarily exhausted, and, refusing passage to the proteoses and peptone formed by proteolysis, render possible further hydrolytic cleavage into leucin, tyrosin, lysatin, etc. ”

“ If it is true, on the other hand, that the healthy organism needs a daily intake of 118 grams of proteid food more or less, in order to maintain physiological equilibrium, to keep up physical and mental vigor, and to preserve the normal power of resistance to the incursions of disease, then we must consider that the good overbalances the evil, and that evil exists in order that good may be accomplished. ”

“ In ordinary proteolytic action, both in the stomach and intestine, it is very apparent that the primary products of proteolysis, the proteoses and peptones, are the chief products formed, and that under normal circumstances the greater portion of the proteid food finds its way from the alimentary canal into the blood, after transformation into one or more of these two classes of products. At the same time, it must be borne in mind that even the acid-albumin formed by pepsin-hydrochloric acid may be absorbed without undergoing further change. ”

“ But no man on earth except myself has ever been able to create a proteid. They have missed the whole secret because they have been working at ordinary temperatures. Just as the drop of water will not form from its two gases at 4,500 degrees Fah., nor at its own lower explosion temperature, unless the spark be added, so will protoplasm not form except under certain electric and thermal conditions. ”

“ On the other hand, if an insufficient amount of proteid is taken, the tissues are improperly nourished, and one is unable to exert his usual strength. What is true of the proteids is true, though in a different way, of the other great classes of foods. A diet which is lacking in proteid, carbohydrate, or fat, or which has any one of them in excess, is not adapted to the requirements of the body. ”

“ But such energy as is liberated in the breaking-down process might be derived far more economically by simple destruction of the proteid, as contained in the meshes of the tissue elements, without assuming a preliminary conversion into living protoplasm. Obviously, we have here a theory which does not help us in arriving at any very satisfactory conception of proteid metabolism. ”

“ The proteolytic power was proved to be due to a specific ferment or enzyme, now universally called trypsin, which digests proteid foods to the best advantage in the presence of sodium carbonate. Digestive proteolysis in the human body was thus shown to be due mainly to the presence of two distinct enzymes, the one active in an acid fluid, the gastric juice, the other in an alkaline-reacting fluid, the pancreatic juice, but both endowed with the power of digesting all varieties of proteid foods, with the formation of a large number of more or less closely related products. ”

“ Hence, proteolysis in the living stomach may give rise to such an increased production and secretion of hydrochloric acid that formation of the terminal products of gastric digestion may be greatly accelerated. That such in fact is the case, I have no manner of doubt, but that it may result in the complete conversion of the so-called primary and secondary proteoses into peptone I very much question. In fact, such examinations as I have made of the stomach-contents after a suitable test-meal have always resulted in the finding of a relatively large amount of proteoses. ”

“ It is very evident from what has been said that all forms of proteid matter, i.e., all the members of the three main groups spoken of in our classification of the proteids, excepting only nuclein, reticulin, and the keratins, are capable of undergoing proteolysis with pepsin-hydrochloric acid. Further, in every case the main products of the transformation are proteoses; viz., albumoses, caseoses, gelatoses, vitelloses, myosinoses, etc., according to the nature of the proteid undergoing proteolysis; true peptones being formed in less abundance. ”

“ Further, the very nature of the proteoses and peptones, their marked physiological action when they are introduced directly into the circulating blood, their rapid excretion, either as proteoses or peptones, by the kidneys when so introduced,207 all indicate that they are foreign substances, totally out of their natural environment when introduced into the blood-current. And yet we very well know that proteoses especially are possessed of high nutritive qualities; they are abundantly able to support animal life. ”

“ The treatment of enlarged prostate is palliative—attention to the general health, the occasional administration of anodyne suppositories or enemata, prevention of accumulation in the lower bowels, either by gentle laxatives or the throwing up of bland fluid, and the avoiding as far as possible all sources to excitement, of mind as well as body. The radical cure, it has been said, is extirpation of the gland, but the cool proposal of such an operation would indicate either ignorance, or dereliction of principle, or mental obliquity, or all combined. ”

“ Now the one great necessity without which we die is proteid, because proteid supplies (and nothing else in the world supplies) the waste which daily and hourly goes on in the body. It is present in conveniently large quantities in all meat foods, which is one of the main causes of their being eaten, but it is present also in large quantities in cheese, milk-proteid, grains, nuts, and pulses, though in certain other fruits and vegetables{102} it is almost completely absent. ”