Therapeutics

Chemiotherapy.

Chemiotherapy, or the use of a drug which has a selective affinity for a germ and leads to its destruction without damaging the tissues of the body, was the conception of Paul Ehrlich of Frankfort-on-Main who in 1910 discovered the specific remedy "6o6" or salvarsan which rapidly leads to the destruction of the Spirochaeta pallida (see VENEREAL DISEASES), the protozoan responsible for syphilis. It now appears that the action is not independent. of the activities of the patients' bodies and that the germ is not poisoned and killed off solely by the drug, which indeed may damage the tissues of the patient very severely and even cause death, so that the ideal of chemiotherapy has not been realised. Remedies of this class are, like quinine in malaria, specific, lead to a complete cure, and are therefore of the greatest importance in opening a new vista in medicine. Since its introduc tion salvarsan and its modification neo-salvarsan "914" and allied organic preparations of arsenic have been increasingly used in the numerous results of syphilis with great success; but this treatment has its limitations, for when the parasite of syphilis gets inside the central nervous system and causes locomotor ataxia and general paralysis of the insane the drug cannot follow the spirochaete and the disease is little if at all influenced. Recently it has been found that inoculation with the malarial organism and an attack of the disease benefits patients with general, paralysis, but how far this is a permanent cure remains to be proved (see MALARIA). Try panosomes, animal (or protozoan) parasites closely akin to spiro chaetes are responsible for diseases, such as trypanosomiasis and African sleeping sickness (to be distinguished from quite a dif ferent disease epidemic encephalitis [see ENCEPHALITIS LETHAR GICA] popularly called sleepy sickness) which are also curable by the organic arsenical compounds atoxyl and arsacetin. Tartar emetic, a salt of antimony, acts like arsenic on trypanosomes and in addition effects a cure in bilharziasis (see BILHARZIASIS) (a disease due to flukes), filarial disease and kala-azar, three tropical infections (see KALA-AZAR; PHARMACOLOGY).

Serum Therapy.

Just as in enteric fever, so in cerebro-spinal ("spotted") fever and pneumonia (see CEREBROSPINAL FEVER) bacteriology has shown the existence of several strains or types of the causal micro-organism; these though morphologically indis tinguishable are so biologically different that each is most effi ciently treated by an antitoxic serum, obtained from an animal injected with, and so immunised to, that particular type. Before the recognition of these types antitoxic serums were employed, but they might or might not correspond to the exact strain of the micro-organism present in an individual case. In 1913 Douchez and Gillespie, working at the Rockefeller Institute, New York, isolated four types of pneumococci, the micro-organism causing acute pneumonia ; but it is only the antitoxic serum corresponding to pneumococcus type I. that is curative.

During the World War, especially in 1915, epidemic cerebro spinal meningitis or cerebro-spinal ("spotted") fever became prevalent among the fighting forces, especially in young recruits.

It is due to the Meningococcus intracellularis (see SPINAL MENIN GITIS; SERUM THERAPY), and in order effectively to neutralise its effects Simon Flexner of the Rockefeller Institute prepared an antitoxic serum from animals immunised from 4o different strains (multivalent). This serum is injected by lumbar puncture into the (subdural) space around the spinal cord, so that it can come into direct contact with the meningococci which chiefly select the cen tral nervous system. The prevalence of the disease stimulated research and strains of meningococci were isolated ; Mervyn Gor don, working for the Medical Research Committee (now Council), isolated four types of meningococci and prepared four correspond ing mono-type sera; when a case was bacteriologically proved to be due to infection with one of these strains, the corresponding serum was given ; while waiting for the bacteriological decision as to the responsible type, a mixture of type I. and type II. serum was given, as 8o to 85% of the cases were due to these strains. Tuberculosis.—The search for a specific remedy for tuber culosis, such as a new form of tuberculin, an antitoxic serum or a metallic preparation analogous to salvarsan or tartrate of anti mony in protozoan diseases, has continued, but no finality has been reached (see TUBERCULOSIS). Spahlinger's treatment by vac cines and serums has received intermittent attention, mainly in the lay press ; Dreyer in 1923, by removing the fatty material from tubercle bacilli, obtained a vaccine, called diaphyte, which has been tried on human beings, and from experiments on animals was at first thought to have an increased effect, as compared with other vaccines; later reports have not been favourable, but both ex perimentally and clinically it may still be premature to decide about its ultimate value. Recently sanocrysine (a gold compound) has been introduced by Mollgaard of Copenhagen and is still on trial; it is a powerful remedy which kills the tubercle bacilli and, by liberating their poisons, may produce severe constitutional reactions; Knud Faber, from his clinical experience, points out that to avoid these dangerous results, the doses should be small. In pulmonary tuberculosis a great factor in obtaining arrest and cure of the disease is rest, and in order to immobilize the lung the production of artificial pneumothorax (q.v.) is now widely prac tised. Air is introduced into the pleural cavity on the side of the affected lung which then collapses and comes to rest, all the work of respiration being carried on by the other lung. This procedure has given very good results in selected cases. Treatment in sana toria is of great value in arresting the progress of pulmonary dis ease and in teaching the patient the laws of health that he must follow, but it is now Decoming recognized that there is urgent need for a more prolonged protection from the strain of ordinary life in the environment of cities, and that tuberculous colonies in the country are required for this purpose, such as Papworth near Cambridge and Preston Hall near Maidstone.