Pathology

PATHOLOGY (from the Greek pathos-suffering and logos-study), literally the science of diseases. However, in connection with the differentiation of our knowledge, pathology has long ceased to be a unified science. Its fully isolated, independent branches today are pathological anatomy (see) and pathological physiology (see). Further distinction is made between general pathology, which studies the regularities of the origin, development, and spread of diseases in general (in the USSR, general pathology as a discipline has been renamed pathological physiology), and special pathology, which develops the etiology, pathology, and clinic of each individual disease. In Russian universities, there has long existed a department of 'special pathology and therapy', the task of which was to describe the most typical diseases of internal organs (without detailed examination of patients and without delving into the pathogenesis of diseases, their differential diagnosis, etc.); since 1923, this department has been abolished in our country. In essence, it is incorrect to apply the term 'special pathology' only to internal diseases, and it should be extended to diseases of all other organs (eye, ear, etc.). The further existing term 'experimental pathology' does not characterize any special branch of knowledge, but rather a specific methodology for studying pathological phenomena, which in fact is used (along with other methods) by many departments of medicine (including all clinical disciplines). In recent times, geographical pathology has developed greatly, which, although it has a special object and methods of study (see Medical Geography), has not yet emerged as an independent science and is studied by epidemiologists and clinicians, as well as pathologists and pathophysiologists. The history of pathology, as well as the struggle of trends and directions in pathology, constitutes an integral part of the history of medicine (see).

S. Levit. Paleopathology--the science of pathological changes found in fossil organisms. The term 'paleopathology' first appeared in print in America in 1895 (Standard Dictionary, v. II, N. Y.). A vast literature has accumulated on paleopathology, in which, besides Americans, German authors have made a significant contribution (among them Virchow). The study of pathological changes encountered in ancient humans and animals was carried out almost exclusively on bone material from fossils, from petrifications of the earliest geological epochs, and on Egyptian mummies from prehistoric times. Soft parts and organs on these objects rarely remained preserved, at best in the form of imprints on stones. In connection with this, judgments regarding the time of appearance of one or another pathological change in animals and humans can be based on paleopathological data only to an extremely limited extent. In general, it must be said that we know nothing about the true time of appearance of diseases, since one cannot assert that they appeared precisely at the time to which the pathological findings belong. Furthermore, it must be assumed that before the pathological changes that appeared acquired established forms, a very long time may have passed. The first visible traces of pathological changes that have reached us date to the Ordovician and Silurian periods; they concern indefinite traumatic injuries of brachiopods and cephalopods, apparently accidental and healed fractures of shell hinges, the shells themselves, etc. The number of pathological increases with the transition to subsequent geological epochs. The first signs of parasitism are found in the Devonian period, and starting from the 12th period, the curve of diseases rises sharply, especially in dinosaurs, crocodiles, plesiosaurs, and sea turtles. Then the curve drops sharply. Many animals (reptiles) become extinct by this time, and a number of diseases cease with them. The mammals of the Cretaceous and early Tertiary periods were apparently not as susceptible to diseases as the previous groups of giant reptiles and as later groups of mammals. The ascending curve of this time is not as steep, but in the future it rises sharply again. Thus, the first manifestation of pathological changes was trauma, as evidenced by fractures and calluses, followed by parasitic processes, caries of bones and teeth, necroses, all kinds of bone hypertrophy, different arthritides, spondylitides, etc. Parasitism was probably preceded by commensalism and symbiosis. Symbiosis of roundworms with corals, with crinoids, as well as of sponges with annelids is known; only later do indefinite lesions of mollusk hinges, deposits on their shells, and other changes appear, indicating the presence of a parasite on the host. An interesting type of parasitism, giving deformities in the form of thickenings on the gill slits, was found in a certain species of Branchioplax washingtoniana (ice age). This animal species has survived to this day on some coasts of America, and the same type of parasitism is still found on it today, as it was many thousands of years ago. The earliest fractures and calluses in fish and reptiles date to the Permian period. Microscopic study of these calluses showed that the lacunae in them are few and they are small, abundantly interspersed with osteoid tissue, the canals are short and unbranched; the lamellae are well defined; Sharpey's fibers are not observed. Thus, the phenomena of bone healing that took place 20 million years ago are approximately the same as they are now. Pictures of apparently infected fractures and bone necroses have also been found. These processes, first found in fish and reptiles, are later observed in all species of fossil mammals and humans. Particularly rich material of this kind relates to finds in caves and concerns their primitive inhabitants-cave bears and lions. Many of the corresponding remains indicate that fractures are not spontaneous but inflicted during struggle. In these same caves, bones with phenomena of necroses, ankyloses, caries, exostoses, hypertrophies, atrophies, and deforming arthritides have been found. The latter have been designated by many authors as 'cave gout,' although apparently they have nothing in common with human gout: the changes do not affect the articular surfaces but consist of bone proliferations along the diaphysis. The origin of these changes, as well as of disfiguring spondylitides, is unknown. Numerous periostoses have also been found. Since it is believed that they are not of syphilitic origin, many authors (including Virchow) believe that similar findings in prehistoric humans should also not be considered syphilis, i.e., they think that the question of the existence of prehistoric syphilis in Europe should be decided in the negative sense. Dental caries and alveolar periostitis appeared in the Cretaceous period and are an extremely common finding in later times. Dental fistulas are not uncommon. Actinomycosis is revealed simultaneously with the appearance of the earliest horses. As for bacteria, even in finds from distant times, filamentous bacteria and cocci (of the diplococcus type) have been discovered. They left traces of their existence in the form of canal passages in the bone substance of bones that lay in swampy places. In addition, bacteria were found in coprolites, as well as in the teeth of all kinds of fish and reptiles. The pictures of dentin destruction under the influence of bacteria in fossils are similar to those that we observe today. Nevertheless, the fossil bacteria causing caries, and in general ancient bacteria, cannot be identified with modern species of them, since we have an idea only of their external form and know nothing of their biological properties. Dental caries should apparently be considered the first bacterial disease process on earth. In the ice age (recent era), all the diseases listed above are encountered; no new ones have been discovered. (Pathology of the predecessor of humans of this period is extremely poorly known. There is only one corresponding document-a femur of Pithecanthropus with exostoses. The main lesions found in the earliest humans reduce to bone injuries, partly spontaneous, partly inflicted by stone arrows or knives. Deforming arthritides and spondylitides, jaw diseases, periostites and exostoses are encountered. Their syphilitic nature is denied. Undoubted evidence of syphilis dates to 1495 (the year of the discovery of America). The additional tubercle on the first molar (tuberculum Carabelli) cannot be considered syphilis, as it occurs almost as a rule in one species of fossil human (Krapina), who lived 75,000 years ago, and also in monkeys. In Neolithic times (10,000 years ago), trepanation of the skull, cauterization, and amputations were well known. Corresponding documents have reached us in the form of objects with traces of the mentioned operations. Diseases of prehistoric humans are represented by mummies of ancient Egyptians (3,000 years old). Atherosclerosis with calcification, resembling atherosclerosis of our time under microscopic examination, was found in them. Lesions were found in young and old and in localization coincide with those observed today (regarding etiology, it should be noted that tobacco was not known at that time). In one of the mummies, a skin lesion extremely resembling smallpox was found. Among thousands of mummies, bladder stones are noted in individual cases. In some cases, Bilharzia haematobia was found in the form of calcified eggs in the kidney (this disease is still prevalent in Egypt). From adhesions in the region of the cecum, one can assume a former appendicitis. Prolapses of the intestines, vagina, hydrocephalus, tuberculous spondylitis with a gumma, osteosarcoma, deforming arthritides and spondylitides, and all kinds of dental caries were observed. In no case was rickets found (also in animals). An idea of some diseases among ancient Peruvians is given by the images that have reached us on clay jugs. Thus we have become acquainted with: gundu (thickening of the back of the nose), skin lesions-verruga peruviana and leishmaniasis (with facial ulceration). Pathological changes in early vertebrates do not represent types of diseases that would essentially differ from modern ones. One can of course assume that many of them at their origin were different and over time modified into their present form, but some part apparently has come down to us unchanged (caries, necroses, some types of parasitism). Part of the diseases may not have reached us at all, since they disappeared with extinct animals. In the process of extinction of individual species, diseases obviously did not play a decisive role. Knowledge and correct interpretation of pathological manifestations of antiquity are very important for understanding the evolutionary process. A striking example of what harmful conclusions can result from the incorrect use of paleopathological data is Virchow's attempt to interpret Pithecanthropus not as a product of regular evolution, but as a pathological manifestation belonging to P.

As is known, the basis of Virchow's approach was the desire to reject the origin of man from monkeys and at the same time to discredit all of Darwin's evolutionary teaching.