Nosology

NOSOLOGY (from Greek nosos-disease, and logos-science), the doctrine of disease or diseases. The distinction between N. and pathology is not sufficiently clear (see also Pathology). Under nosos is usually understood disease as a process, i.e., taken as a concept of dynamic order, while pathos, or pathies—diseased condition as something more or less stationary, usually arising as a result of disease (e.g., defect of heart valves—pathos, which led to it endocarditis—disease). However, pathology deals by no means only with pathic states in the just-mentioned sense, but also to an even greater degree with pathic processes. Therefore, the name 'pathology' by no means corresponds to the content placed in it. French authors distinguish affection and maladie. Under affection (=pathos) is understood the totality of morbid phenomena connected with a certain damage to this or that organ or tissue without regard to the producing cause (e.g., embolism of the pulmonary artery, cirrhosis of the liver, inflammation of the kidneys). Maladie (=nosos) is the totality of morbid phenomena developing under the influence of some definite cause. In this latter sense one speaks of plague, syphilis, leprosy, tbc, etc., as special diseases, separate nosological units regardless of localization, spread, character of the process, and other peculiarities. What is understood by the word affection corresponds to the concept of disease in the anatomical sense, whereas maladie is primarily an etiological concept. Rossle divides all pathology into the doctrine of malformations, or teratology (disontogenesis), and N., or the doctrine of disease in the proper sense. According to Rossle, therefore, N. merges with pathology in the part remaining after deducting teratology. In any case, one thing is indisputable, that the concept pathology is broader compared with the concept N., or, as Tendeloo expresses it, pathology is a generic, and N. a specific concept. At the same time, just as general and special pathology are distinguished, one can also speak of general and special N. Standing on the ground of Rossle's definition, and also guided by word-formation, one should include in general N. everything that pertains to the doctrine of disease in general, among other things general etiology, pathogenesis, i.e., the mechanism of development of corresponding pathological processes, their dynamics, and finally special pathological processes and functional disturbances of individual organs and systems. Into N. should also enter the doctrine of classification of morbid forms, of the principles of construction of the so-called nosological units. This last task (classification) is moreover so important that some authors identify the very concept of N. with the classification of morbid forms, which is however clearly incorrect. Thus or otherwise, N., understood as the entire doctrine of diseases as a whole, should in essence cover almost everything that constitutes the theoretical side of medical knowledge. In such scope N. as a doctrine does not exist. Modern pathology, highlighting as separate major chapters the doctrine of etiology (see>) and the doctrine of pathogenesis (see>), leaves to N. the treatment of only the following questions: about the essence of disease and about the classification of morbid forms, including their description, so-called nosography. Depending on the state of science, N. at different times changed its position on a number of questions, in some cases, it is true, only clarifying and supplementing the corresponding content, in others as if fundamentally rebuilding its 'front'. Such a crisis-like position in the sense of revising basic, long-established viewpoints is noted in N. at the present time. 1. The understanding of the essence of disease changed fundamentally at different times (see Disease). After the period of dominance of ontological, and then primitive humoralistic concepts, the localistic principle was introduced into N. (Morgagni; 1766), which much later received its maximum development in Virchow's 'cellular pathology'. At present, while continuing to recognize the importance of the cell in the origin of pathological processes, nosological concepts as a whole have nevertheless undergone considerable shifts. Firstly, too straightforward cellularism proved insufficient for a comprehensive evaluation of pathological phenomena, especially in the field of immunology and endocrinology. In the latter field, for example, we have the cardinal fact—the realization of 'consensus partium' purely by chemical-humoral means; furthermore, the hormonal effect can change not only quantitatively but also qualitatively, under the influence of fluctuations in the content of ions at the site of hormone action, while the fluctuations themselves are connected with changes either in the tone of the autonomic nervous system or in the ion content of the plasma. Although the initial and final moment in this chain of phenomena is of cellular character, here we essentially have a humoral process. Thus, remaining on the ground of cellularism, modern N. at the same time has taken a step in the direction of humoralism, investing, it is true, in the concept of humoral moments a more concrete and somewhat different content compared with previous pathology. Secondly, having at the center of attention active cellular elements, one in no way can underestimate according to modern views the significance of intercellular substance. The latter is the bearer, besides mechanical, also of osmotic and oncotie forces and plays the role of an intermediary between cells and blood. In view of this, in interpreting the pathogenesis of edema, for example, it is necessary to take into account the participation of this substance. Furthermore, age-related changes in the physico-chemical constitution of the organism are to a large extent determined by changes in the properties of intercellular substance, by its gradual transition from a semi-liquid state to a gel with subsequent disturbance of the vital activity of cellular elements. The intercellular substance of connective tissue itself is subject to the action of some secretions (condition of subcutaneous tissue in myxedema). The examples cited illustrate two important factors that stood until very recently outside the sphere of attention of N.: the role of intercellular substance in the pathogenesis of pathological processes and the humoral moment influencing it. Thirdly, the very concept of the cell of a multicellular organism as an independent biological individual proved to be an abstraction, not corresponding to reality either morphologically or physiologically. In the first respect it is sufficient to point to the fact of the presence everywhere of anatomical connections between cellular elements, reaching maximum expression in epithelium (complexity), but also existing even among what seem to be randomly scattered cellular elements of mesenchyme. A number of corrections have been introduced also into the concept of organs as isolated formations: everywhere there are vascular and nervous connections, and hence the inevitability to a greater or lesser degree of various reflected phenomena even in distant parts of the body in case of disease of a certain organ. To some formations it is difficult to apply even the very name 'organ', which is why here one speaks of systems (for example, reticulo-endothelial system, chromaffin system, etc.). From the physiological side, the difficulties for the concept of organs as isolated physiological units are illustrated by such facts as the doctrine of central and peripheral heart, of pulmonary and tissue respiration, of the secretion of bile not only by the liver but also by the ret.-end. system, of the intimate participation in the process of urine formation not only of the kidneys but of all other tissues. The specificity of hormonal organs can be recognized only with large reservations: thus, along with adrenaline there are adrenaline-like, vasoconstrictive substances of blood serum; choline, recognized by some as 'Peristaltikhormon' and the hormone of the adrenal cortex, is found not only in the intestines and adrenals but generally everywhere where only the breakdown of lecithin takes place; ovarian hormone has been found not only in the ovaries but also in the placenta and even in the male sex glands; the presence of insulin has been established particularly in large quantities along with pancreas in the liver and among other things in the submaxillary gland; finally and the so-called 'cardiac hormone' of Haberlandt proved to be if not 'ubiquitous', still located by no means only in the cardiac muscle. Essential corrections are also introduced into the concept of the tissues of the organism. Analysis of the structure of relationships between muscles and nerve endings showed, for example, that there are no muscular and nervous systems or isolated systems, but there exists a neuromuscular apparatus. It is quite clear how this circumstance changes our concepts of the structure of the indicated parts. From all that has been said it is evident that the so-called organ principle, as not embracing the whole sum of phenomena connected with disease, should not be accepted unconditionally in constructing nosological concepts, but should be supplemented and corrected in accordance with the above-mentioned modern nosological provisions. In many cases the former concept of 'sedes morborum' proves too simplified, needing expansion and of necessity complication.

However, somewhat simplified concepts, as well as methods of simplification, have their raison d'etre when studying complex phenomena as an inevitable intermediate stage in the disintegration of the latter on the path to further synthesis, for example, Kravkov's method of isolated organs, Carrel's method of tissue cultures. In both cases, only a certain caution and correction are required when transferring the obtained data to the organism as a whole. All of the above dictates the following two conclusions that are essential from a nosological point of view: first, the need to revise the question of dividing diseases into local and general; second, the necessity, when constructing nosological concepts, not to be satisfied with only the 'local' principle, but to proceed from the particular to the general, from the organ to the whole individual. The division of diseases into local and general from a symptomatic point of view is understandable, but from a nosological point of view, it encounters great difficulties in many cases. For example, the anthrax pustula maligna can be considered in a certain sense as a 'local' disease as long as the bacteria have not penetrated into the blood. However, it is impossible to say with complete certainty about any given moment, even an early one, that the latter have not yet entered the blood, even in the form of individual specimens; moreover, the absorption of toxic substances already takes place in the early stages of the disease, which manifests as a general temperature reaction, and with the onset of fever, the process undoubtedly changes from local to general, and the general in one form or another inevitably reflects on the local. The material relating to the question under discussion, in the vast majority of cases, represents what in dialectical terms is called the 'interpenetration of opposites' and can be briefly characterized by the formula: 'the local in the general' and 'the general in the local'. A good example of such interpenetration could be the comparison of a wound with sepsis: the wound as a primarily local process can give rise to sepsis as a general phenomenon, but £31 once this latter has arisen, it immediately reflects on the local, i.e., on the wound—the latter takes on the so-called septic appearance. As knowledge expands, what until recently seemed local begins to be interpreted as an expression of the general. For Virchow, with his localist approach to £L, there were no general diseases at all, because, according to the 'testimony of path. anatomy, there is not a single disease in which all organs are affected; on the contrary, one always finds unchanged some tissue or other'. For him, the so-called 'general infections' were not such either, although it is precisely on this last example that one can most clearly show the complete untenability of such a point of view. Atherosclerosis was recently treated as a disease only of the vessels; now there is a tendency to link it with a general disturbance of cholesterol metabolism. In explaining renal edema, it is assumed that the same toxic cause both damages the kidneys and increases the porosity of the vascular filter. However, even without such an assumption, can one speak of a local disease in such cases when at the same time operating with such general pathogenetic concepts as increased molecular concentration and hydrophilicity of tissues? Sexual functions often suffer depending on extragenital factors, for example from general obesity or general exhaustion, and the condition of the skin has long been rightly regarded as a 'mirror' of the internal state—general metabolism and the nervous system. Finally, even such seemingly 'isolated' diseases as glaucoma have, according to Fischer (M. Fischer), a common pathological substrate—acidosis, and the course of the wound healing process is strongly influenced by the state of the general nutrition of the organism. The high nosological significance of the 'general' is also illustrated by the modern doctrine of constitution. Usually, constitution is understood as the sum of the anat.-physiol. peculiarities of the organism that determine its reaction to irritations. However, the sum should not be understood as the result of a simple addition of the peculiarities of individual organs; the concept of general constitution also includes the idea of the nature of the connection, mutual coordination and regulation of tissues and organs. Each individual property of the organism or peculiarity of each of its organs is therefore not a simple component, but at the same time a function of the whole. For example, we have an exudative diathesis not because the subject has a tendency to prurigo, urticaria, eczema, rhinitis, laryngitis, bronchitis, conjunctivitis, etc.—such a sequence of reasoning is used only when establishing a diagnosis, but because there is a tendency to all the aforementioned disease forms, which is based on a constitution with the character of an exudative diathesis. In the field of genetics, a corresponding shift has also occurred recently. Quite recently, among Mendelian laws, there was the position on the 'independence of inherited traits'; now, following Morgan, not only is their linkage admitted as a common phenomenon determined by the 'linear arrangement of genes in chromosomes', but also the influence of each individual gene on almost all parts of the body and vice versa—the participation of the entire germ plasm in the development of each part of the body. The significance of the 'whole', the organism, for nosological concepts is also evidenced by such facts as the variability and two-phase nature of the hormonal effect, as well as the effect of vagotropic and sympathicotropic drugs depending on the general state of the organism (the tone of its autonomic nervous system, ion concentration, etc.). Even more indicative are the searches of modern therapy, which characterize the nosological shift in the area under discussion. Krehl calls for treating the entire individual, not forgetting, among other things, the effect on his psyche, thereby as it were expanding the old well-known slogan: 'treat the patient, not the disease'. Kraus develops the 'pathology of personality'. The search for the most refined specificity has been replaced by the method of non-specific Reiztherapie, where the bet is undoubtedly on the non-specific stimulation of the organism as a whole. In surgery, doubt has arisen about the rationality of many operations dictated by the organ principle, and in their place, indications are accumulating that it is possible to obtain the desired effect in a completely different way, having nothing in common with the principles of purely organ pathology: a simple incision of the organ instead of a special operation on it, and sometimes even near it, for example, a simple incision in the lumbar region instead of an operation on the kidney; Bier even treats by simple cauterization of some area of the body with a hot iron. Such a paradoxical fact apparently indicates that the matter here is not so much in the nature of the surgical intervention as in the intervention as such. In view of this, the question has been raised about the general effect of aseptic surgical intervention on the organism along with the local one in the form of a kind of Reiztherapie (changes in blood, increase in peptolytic ability, etc.).—In the department of general etiology, nosology is increasingly moving away from primitive etiological views, which is particularly evident in relation to infectious diseases. The initial primitive viewpoint, which reduced almost everything to the microbe in the question of the etiology of infectious diseases, no longer satisfies anyone today: the well-known facts of bacillus carriage are sufficiently eloquent in this respect, and in its place another concept has been put forward, the essence of which is characterized by the formula: infection is a function of three variables: the microorganism, the macroorganism, and the environment. The role of the macroorganism must be properly taken into account also in interpreting outbreaks of epidemics, since it is hardly possible here to reduce everything to the introduction of the corresponding causative agent and fluctuations in its pathogenicity. Accordingly, the viewpoint on the treatment of infectious diseases and in particular on chemotherapy must now be revised. The expectation of parasitotropy of medicinal substances has only been partially justified: therapia sterilisans, as it turns out, is carried out not only by the effect of salvarsan on spirochetes but also by the active participation of the reticulo-endothelium in this process.—The question of the routes of spread and mechanism of development of the pathological process—see Pathogenesis. As for the systematization of diseases themselves, with the development of medical knowledge, particularly in the field of etiology and path. anatomy, significant progress has been made over time, although problems requiring their resolution still remain on this path. The work of nosological thought in this direction was twofold: on the one hand, analytical—towards the differentiation of diseases as individual nosological units, and on the other—synthetic, towards the classification of diseases into separate groups. By the name nosological unit is meant a more or less definitely delineated in its essence disease form, the latter being to a certain extent impersonal, since Nosology does not simply list or add, but integrates individual cases, i.e., individual diseases, into nosological units.

In the construction of nosological units, etiology has dominant significance, but to a certain degree the pathological-anatomical substrate, if such exists, and the nature of functional changes are also taken into account, as well as to some extent the symptomatology. For a long time only a symptomatic approach was possible, but now a more profound, nosological approach in the true sense of this word is also possible. Symptomatology, however, should not now be ignored, since the symptom as an expression of the body's reaction serves to characterize the disease from the standpoint of its essence. The isolation of nosological units is sufficiently simple in some cases, while in others, on the contrary, it encounters certain difficulties. The question is clear when it comes to comparing such heterogeneous diseases as, on the one hand, for example, any typical infectious disease, and on the other hand, gout, traumatic injuries; it is also clear in regard to such so-called specific infectious diseases as plague, cholera, typhus, Siberian ulcer. In particular, various forms of tuberculosis, despite the diversity of clinical pictures depending among other things on the affected organ, provide grounds for treating as a single nosological entity. Various syphilitic lesions, of course, should also be combined into one nosological unit, despite symptomatic dissimilarity (for example, syphilis of the brain and syphilis of the bones), but progressive paralysis already deserves to be isolated into a special nosological unit, since here in addition to spirochetes other etiological factors are also significant, in accordance with which the attitude of paralytics to specific treatment is different from that of vulgar luetics. But the question is already somewhat complicated when attempting nosological combinations of those infectious diseases in which different microbes can give the same clinical phenomena, on the one hand, while on the other hand the same microbe can give different lesions, which applies especially to staphylococcus, streptococcus, pneumococcus, and Bact. coli. Streptococcus, for example, can cause an abscess, erysipelas, angina, osteomyelitis, and ulcerative endocarditis. Here, it would seem appropriate to replace the etiological principle with a localistic one in isolating nosological units. If even here the same etiological concept is maintained, then all the listed diseases will have to be treated as streptococcoses with different clinical pictures depending on the different relationship of the macroorganism to the microorganism. Here we come to the recognition of the possibility of classifying diseases also on the macrobiological principle, i.e., therefore judging not only by the type of infection but also by the type of reaction; for example, one speaks of so-called allergic diseases. The symptomatic principle does not guarantee accounting for the essence of the disease, although it must be noted that in the hands of experienced clinicians such an approach to the systematization of clinical material did not ultimately prevent the reduction of diseases into nosological units nor their classification to a certain extent into groups. Thus, in infectious diseases clinicians dealt sufficiently well long before the bacteriological era, and Laennec combined various forms of tuberculosis before the discovery of the tubercle bacillus by Koch. The main disadvantage of etiological concepts lies primarily in that here sometimes too dissimilar clinical forms are combined, and conversely, obviously similar symptological groups are broken up. The help of pathological anatomy in the classification of diseases is very valuable: it was by this very path that Louis once separated typhoid fever from the group of so-called putrid fevers, but the use of exclusively pathological-anatomical criteria in turn can lead to erroneous generalizations: for example, in Virchow, lymph tumors, scrofula, tuberculosis, typhoid fever, and leukemia all appear under the same heading. Moreover, not all diseases have a visible pathological-anatomical substrate—the pathogenetic concept would be convenient in terms of simplicity, since there are relatively few paths of pathogenetic action, but on the other hand, such a path or method of action of the pathogenic agent is not always known; besides, the same agent could act by different paths, for example through the nervous system and directly on the cell, causing nutritional disorders of the latter. An ideal classification would therefore have to be simultaneously symptomatic, etiological, pathological-anatomical, and pathogenetic. However, due to the impossibility at present of creating such, one has to be content with less perfect constructions, based on the maximum possible similarity in certain respects. In other words, where obvious etiological factors predominate, it is more correct to combine the corresponding disease forms according to the etiological principle as basic (infectious diseases, pneumoconioses, nutritional diseases, traumatic injuries and poisonings, etc.). If an etiological approach is impossible, one must be guided by data of a symptomatic and anatomical nature, for example tumors, vascular diseases, mental diseases, kidney diseases, etc. A single classificatory principle cannot be given at present. The first attempts at the classification of diseases go back to the 16th century (Fernel, 1558, and especially Felix Platter, 1560). But only in the 18th century, following the example of naturalists, there appeared among physicians creators of systems attempting to group all diseases into genera and species. Sauvages counted 2,400 species. Then followed the works of Vogel, Vitel, Macbride, and Cullen. At the beginning of the 19th century, Alibert ("Nosologie naturelle ou les maladies du corps humain, distribuees par familles", P., 1817) produced a complete reform in this regard. Based on botanical data, he changed the terminology and divided diseases into families, genera, species, and varieties. But for a long time the classification of Pinel ("Nosologie philosophique ou la methode de l'analyse appliquee a la medicine", P., 1818), created under the influence of Bichat's ideas, enjoyed the greatest success. Its disadvantage, however, lies in combining by no means always homogeneous facts. As an example of modern classifications, one can point to Roger's system, who divides all diseases into five groups: I—parasitic infectious, II—parasitic non-infectious (for example, trichinosis, helminthiasis, etc.), III—toxic, IV—traumatic, and V—organic lesions (affections). The first are in turn divided into specific and non-specific, and both of these into general and local. Among general specific ones there are 4 varieties: exanthematous diseases, septicemic (anthrax, plague, trypanosomiasis, typhus), with a tendency to nodular formations (tuberculosis, glanders, actinomycosis, etc.), and of neoplastic character. Among local non-specific ones— infections accompanied by inflammation: exudative, suppurative, degenerative, pseudomembranous, ulcerative, gangrenous. Toxic ones are divided into exogenous and endogenous, and among affections there appear three varieties: acquired, hereditary, and congenital.