Chemotaxis

“ The non-sensitiveness of a cell to a toxic body when brought into immediate relationship cannot, however, be explained further than by saying that the disintegrative changes which underlie symptoms of poisoning are not brought about. Then as regards natural powers of destroying bacteria, phagocytosis aided by chemiotaxis plays a part, and it can be understood that an animal whose phagocytes are attracted by a particular bacterium will have an advantage over one in which this action is absent. ”

“ The bacteria elaborate a chemical substance which attracts the phagocyte, and this is termed "positive chemiotaxis."80 But it may occur that the chemical substance produced by the bacteria may have an opposite, or repellent, effect upon the leucocytes, in which case we have "negative chemiotaxis."81 It is not to be wondered at that such a theory of immunity based upon microscopical observations, should at first have been widely accepted, and there can be no doubt that Metschnikoff has collected a considerable mass of evidence in support of a theory of phagocytosis. ”

“ Phagocytosis is the act by which the leucocytes englobe and dissolve the invading microbe. By its amœboid movement the leucocyte flows around, and envelopes the microbe for which it has a positive chemiotaxis, and then begins the struggle of vitality between the two living germs. If the poison (leucomaine antitoxin,) and digestive ferment (enzyme) of the leucocytes are more deadly to the invading germ, than its ptomaines, toxins and enzymes are to the leucocyte, the white cell comes off the victor, and recovery takes place, but if the converse obtains the triumph is on the side of the microbe. ”

“ Toxins. As bacteria grow, certain poisonous chemical substances appear about them. These poisons are produced by them directly, or are formed in the organic matter or tissues in which they live, as the result of their presence. Some of these substances are alkaloidal and are known as ferments or ptomains. Others are albuminous in nature and are called toxalbumins. The ptomains and toxalbumins are exceedingly powerful poisons, producing local necrosis, inflammation and even suppuration, when introduced by themselves and entirely free from living germs, into the tissues of animals. ”

“ Potassium and Sodium Hydroxides. In solutions of 1-3 per cent all tissue-structures swell and dissolve or become unrecognizable except elastic fibres, fat, pigment, amyloid, bacteria, yeasts and moulds. Used especially for examination of skin-scrapings or pus for presence of blastomyces and various forms of parasitic moulds (barber’s itch, ringworm, tinea, etc.) . Solutions of 33 per cent clear the tissues but do not destroy the cells. Useful for maceration. When diluted the cells are destroyed. ”

“ The amboceptors so necessary for the destructive action of the serum are produced by the body cells, particularly the leucocytes. The serum assists in pagocytosis by the action on bacteria of substances called opsonins which are contained in it, and the formation of which can be very greatly stimulated. Again, not all inclusion of bacteria within leucocytes is indicative of phagocytosis; in many cases the bacteria seem to find the best conditions for existence within the leucocytes, and these and not the bacteria are destroyed. ”

“ They have been attracted to the damaged area. The mechanism which effects this attraction is a chemical one—chemiotaxis. At the seat of the change chemical substances are produced which act upon the phagocytes, causing them to migrate towards the source—positive chemiotaxis. Apparently the material dissolving from cell débris can act in this manner. Thus if a capillary tube filled with a tissue extract be inserted under the skin of an animal, within a short time it will be found to be surrounded with numbers of leucocytes, which may also have encroached into the tube itself. ”

“ If examined microscopically, the liver and kidneys show no change, save a fatty degeneration and infiltration of the epithelial cells. In the muscular substance of the heart, under the endocardium, there is almost constantly noticed ecchymosis. In the most acute cases, in which a cholera-like diarrhœa has exhausted the sufferer, the blood may be thickened from loss of its aqueous constituents, and the whole of the organs will present that singularly dry appearance found in all cases in which there has been a copious draining away of the body fluids. ”

“ In this process there are two factors concerned, viz. the ingestion of bacteria by the cells, and the subsequent intracellular digestion. If either of these is wanting or interfered with, phagocytosis will necessarily fail as a means of defence. As regards the former, leucocytes are guided chiefly by chemiotaxis, i.e. by sensitiveness to chemical substances in their surroundings—a property which is not peculiar to them but is possessed by various unicellular organisms, including motile bacteria. When the cell moves from a less to a greater degree of concentration, i.e. ”

“ The coal-dust and the iron-filings are often sharp and jagged fragments, which penetrate the delicate tissues, and the escaping red blood-corpuscles are acted upon by the amoeboid cells in the air-passages, with the consequent formation of hæmatin or hæmatoidin, as are the blood-corpuscles in larger hemorrhages. The inhaled pigment finds its way, either directly or by the agency of amoeboid cells, into the lymphatics and fibrous tissue of the lungs, and remains indefinitely either in the bronchial and pulmonary lymphatic glands or in the interstitial tissue of the lungs. ”

“ In all cases in which the albuminous metabolism is very rapid, in cases of disease which are accompanied by decay of the tissues, as in the case of carcinoma, in cases of absorption of exudates and transudates, in all purulent processes, and lastly, in effusions of blood, the blood always contains a larger quantity of such compounds. The blood serum must further be absolutely free from hæmoglobin, and in doubtful cases the spectroscope should be used. ”

“ Administered in over-doses or for too long a time, carbolic acid produces stomatitis, œsophagitis and vomiting.
True poisoning is characterised by changes in the kidneys and bladder; the urine becomes brown and turbid, and possesses a well-marked carbolic odour, the animals suffer from severe trembling and appear stupid, and coma and paralysis precede death.
The specific lesions consist in parenchymatous nephritis, sometimes accompanied by renal hæmorrhage, cystitis and hyperæmia of the lung and brain. The flesh has an odour of carbolic acid, which renders it unfit for human consumption. ”

“ In about ten minutes, as the child cried a little, three drops more of chloroform were used for inhalation, and in about eight minutes more the operation was concluded. “On raising the child it laid its head on one side, convulsive twitches of the face were observed, with distortion of the eyeballs and dilatation of the pupils. For one moment the arms were stretched out stiff, then again they were relaxed, and fell as supple as the rest of the body. Death quickly followed—only one pulsation of the heart and a single râle with the expiration being perceived.” ”

“ Among stimuli acting unilaterally, perhaps none has proved more interesting, in late times, than what is known as Chemiotaxis. By it is meant the property an organism endowed with the power of movement has to move towards or away from a chemical stimulus applied unilaterally, or, at any rate, where it is applied in a more concentrated state on the one side than on the others, and more particularly where the concentration increases gradually in one direction away from the living organism acted upon. ”

“ The essential action of potassic chlorate seems to be that it causes a peculiar change in the blood, acting on the colouring matter and corpuscles; the latter lose their property as oxygen carriers; the hæmoglobin is in part destroyed; the corpuscles dissolved. The decomposed and altered blood-corpuscles are crowded into the kidneys, spleen, &c.; they block up the uriniferous canaliculi, and thus the organs present the curious colouring seen after death, and the kidneys become inflamed. ”

“ As is well known, blood serum possesses, as a rule, a bactericidal power upon most micro-organisms, and we have every reason to believe in the existence of specific substances in the serum which exert some influence upon the growth and development of micro-organisms, and also upon the toxic products they tend to elaborate. These protective substances—the alexins of Buchner—appear to be proteid in nature, resembling globulins, since they are precipitated from serum by the action of certain strong solutions of alkali salts, as sodium sulphate. ”

“ More usually, if the operation lasts more than a minute or two, it is necessary to repeat the inhalation; it is, indeed, generally desirable to let the patient have a few inspirations of air charged with chloroform vapour every half minute or so, whilst the operation continues, in order to keep up the insensibility. When the surgeon is cutting in the neighbourhood of important parts, it is desirable to prevent any sign of sensibility, and to keep repeating the chloroform so as to keep up the coma, without, however, causing embarrassment of the breathing, or wide dilatation of the pupil. ”

“ If not too much of the toxin is given, instead of injuring, it acts as a chemical stimulus to the cell in the manner already described. The cell in response produces more of the specific thing, which in this instance is more receptors which can combine with the toxin, i.e., with its haptophore group. If the stimulus is kept up, more and more of these receptors are produced until an excess for the cell accumulates, which excess is excreted from the individual cell and becomes free in the blood. ”

“ However this may be, it is pretty certain that the blood generally remains fluid in the human body after death from chloroform, only because it usually remains fluid in every kind of sudden death. When a patient dies slowly of illness, the body cools gradually before death takes place, and ammonia keeps exhaling in the breath, if Dr. Richardson is correct, whilst the formation of this alkali must be almost suspended. In many cases, we know that coagulation of the blood commences before the respiration and circulation have ceased. ”

“ The above case comes under the second division of this disease, where the irritative process resulting from the foreign body pervading the lungs, had advanced so far as to produce a variety of small cysts, and circumscribed, indurated masses, the former containing fluid, and the latter solid carbon, and it is evident in tracing its progress, that there must have been a very rapid increase within the system in the carbon originally deposited in the pulmonary structure by inhalation. ”

“ This may seem strange, but it would surprise you if you knew how very commonly there was imperfect intestinal excretion, or intestinal stasis, as it is now called, in these subjects; indeed, I might almost say that it is the rule, and that this assuredly plays a most important part in the auto-intoxication which leads up to cancer; in fact, I almost feel like saying that the toxins produced by the millions of micro-organisms generated through intestinal stasis and fecal putrefaction are the real, incidental cause of cancer. ”

“ When the body is enervated, elimination is checked. This, in turn, results in a retention of toxins in the blood--the condition which we speak of as toxemia. This state produces a crisis which is nothing more than heroic or extraordinary efforts by the body to eliminate waste or toxin from the blood. It is this crisis which we term disease. Such accumulation of toxin when once established, will continue until nerve energy has been restored to normal by removing the cause. So-called disease is nature's effort to eliminate toxin from the blood. All so-called diseases are crises of toxemia. ”

“ This condition of the blood, which is known as _leucocytosis_, is believed to be due to an excessive output and rapid formation of leucocytes by the bone marrow, and it probably has as its object the arrest and destruction of the invading organisms or toxins. To increase the resisting power of the system to pathogenic organisms, an artificial leucocytosis may be induced by subcutaneous injection of a solution of nucleinate of soda (16 minims of a 5 per cent. solution) . ”

“ There are some further effects of chloroform with which one becomes acquainted in experiments on the lower animals. If the inhalation is continued after the symptoms just described are produced, the breathing is rendered difficult, feeble, or irregular, and is sometimes performed only by the diaphragm, whilst the intercostal muscles are paralysed. If the dose of chloroform is gradually increased after these effects are produced, the breathing entirely ceases, but the heart continues to pulsate very distinctly, till its action becomes arrested by the absence of respiration, as in asphyxia. ”

“ Personally I believe that sooner or later it will be generally recognized that the starting point of cancer occurs in some cell or cells, previously normal, probably as the result of local irritation, in which there is a deposit of some of the elements of faulty nitrogenous partition, induced by undue ingestion of animal protein: and that the malignant, reproductive process in the cells is kept up by a continuance of the same supply of imperfectly disintegrated nitrogenous matter. ”