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The aim of the research was an experimental study of the specificity of morphological change development in internal organs with long-term exposure of the body to various production factors: coal-rock dust and sodium fluoride. Materials and methods. The study was conducted on two experimental models: anthracosilicosis and fluoride intoxication. After 1, 3, 6, 9, 12 weeks of exposure to harmful factors, in experimental animals, the lungs, bronchi, heart, liver and kidneys were sampled for subsequent histological processing. Results. The exposure of the body to coal-rock dust and sodium fluoride leads to the development of adaptive reactions in the internal organs of animals in the 1st-3rd weeks of the experiment, which is a universal mechanism in the early stages. Their further intake causes the formation of organ-specific manifestations depending on the acting factor. Inhalation of coal-rock dust is accompanied by an early breakdown of compensatory mechanisms of the respiratory organs and heart muscle and the formation of pneumosclerosis, atrophy of the bronchial mucosa, and degenerative changes in cardiomyocytes from the 6th week of the experiment. Cardiosclerosis develops by the 12th week. In the liver and kidneys, dystrophic changes in parenchymatous cells are restrained by reparative processes and develop by the 9th week of the experiment. Accumulation of sodium fluoride leads to the early formation of pronounced protein dystrophy of hepatocytes and nephrocytes with the formation of necrotic foci by the 6th-9th weeks of the experiment. Disturbances in the bronchopulmonary system before the 9th week of exposure are of the nature of immune inflammation with subsequent development of degenerative changes in the air-conducting structures. Moderate dystrophy of the parenchymatous component is characteristic of the heart muscle throughout the experiment. Regardless of the influencing production factor, changes in the vessels of the organs under study are characterized by hypertrophy of smooth muscle cells of the media, endotheliosis, hyalinosis and fibrosis of the perivascular zones. Conclusion. Identification of the stages of morphological changes has practical significance for elaboration of recommendations for determining the timing and methods of prevention and correction of disorders caused by exposure to coal-rock dust and sodium fluoride.

Relevance. Generalized infections are characterized by a severe course with multiple organ failure. The use of different infection models, the lack of a unified system for assessing organ damage makes it difficult to interpret and extrapolate the results. The purpose of the study – to develop criteria for assessing kidney and liver dysfunction in associated infection modeled by cultivated (CB) and uncultivated bacteria (NCB) of P. aeruginosa and S. aureus. Methods. There were 58 rabbits used in the experiment, divided into III groups. The animals were infected with CB and NCB forms of P. aeruginosa and S. aureus bacteria isolated from the wound contents of patients with thermal trauma. The functional, pathomorphological state of the kidneys and liver was studied, morphometry and statistical analysis were performed. Results. In healthy animals, a statistically significant weak direct linear correlation between biochemical and morphometric parameters characterizing the functioning of the kidneys and liver was revealed. Under the conditions of the SIRS, an increase in the severity of the direct linear correlation to strong and very strong in animals of the IA, IIA and IIB subgroups was noted. There is no correlation in the IB subgroup. A stable statistically significant linear correlation between functional and morphometric indicators reflecting the state of the kidneys and liver indicates the development of hepatoprenal syndrome as a manifestation of the mutual burden syndrome characteristic of generalized infection. Conclusions. Critical periods of violation of correlational relationships are revealed, reflecting the violation of the conjugacy of the functioning of internal organs. When infected with CB, the body's ability to compensate for structural and functional disorders persists for up to 8 days of the disease. On the 11-12th day, liver and kidney dysfunction develops, maintained and aggravated by the syndrome of mutual aggravation. When infected with NCB, the disease acquires a lightning-fast course. The correlation between biochemical and morphometric parameters is maintained up to 2-5 days. The death of animals on the 8th day of the experiment was caused by a violation of the conjugate functioning of the liver and kidneys, reflecting the early development of multiple organ failure.

Objective. In recent years, an increase in the incidence of infectious diseases caused by bacterial associations has been noted. The change in the species composition of microorganisms in associations requires studying the mechanisms of interaction of pathogens, identifying the role of associated microflora during the infectious process. The purpose of the research is to study the pathomorphology of the animals organs infected with P. aeruginosa and S. aureus in cultivated and non-cultivated forms; determine the microbial landscape of blood and internal organs; identify the biochemical characteristics of microorganisms. Methods. The experiment was carried out on 58 rabbits, divided into 3 groups. The animals were infected with cultivated and non-cultivated forms of P. aeruginosa and S. aureus bacteria isolated from patients treated in the burn department of the Regional Clinical Hospital N 1 in Tyumen. Species identification of bacteria in dead animals in blood, liver, lungs and kidneys was carried out with a study of their biochemical properties. Results. It was revealed that the death of animals on the 8-9th day developed due to DAP of the lungs and discirculatory – destructive changes in the parenchymal organs. On the 11-12th day, the second peak of mortality was noted, due to the progression of systemic inflammation. In group II, on the 2-5th day, the fulminant course of the disease led to massive death of animals due to the inclusion of E. coli in the association. The second peak of mortality on the 8th day of the disease is due to systemic inflammation and progressive multiple organ failure.Conclusions. When animals are infected with the association of P. aeruginosa and S. aureus in an uncultivated state, they are reversed to an uncultivated state. The liver is a reservoir of infectious origin in a generalized infectious process. The translocated E. coli acquired atypical properties that enhance its virulence. In a cultivated form, translocated E. coli can exist as a monoculture or in association with P. aeruginosa and S. aureus, contributing to a more severe course of the infectious process due to a synergistic effect.

Objective – currently, associated infections in the structure of human infectious diseases cause high mortality, difficulty in diagnosis and treatment. In the literature, the issue of lung pathomorphology during infection with P. aeruginosa and S. aureus in cultivated and uncultivated forms of bacteria is insufficiently illuminated. The aim of this study is to study the morphological features of lung damage in experimental infection caused by the association of cultivated and uncultivated forms of P. aeruginosa and S. aureus bacteria. Methods. The experiment was carried out on 58 rabbits of the «Soviet Chinchilla» breed, divided into 3 experimental groups. To infect rabbits, a suspension of cultivated and uncultivated forms of bacteria P. aeruginosa and S. aureus isolated from patients undergoing treatment in the burn department of the Regional Clinical Hospital № 1 of the city of Tyumen was used. A microscopic examination of the lungs was performed using standard histological techniques. Results. In the first group of experimental animals, the lethality was 22 (84.6 %) rabbits, of which on the 8-9 day – 18 (81.8 %) and on the 12th day – 4 animals (18.2 %). In group II, 24 (92.3 %) rabbits died, from the 2-5th day – 18 (75 %) and on the 8th day of the experiment – 6 (25 %) animals. Morphological changes in the lungs correspond to the first phase of diffuse alveolar injury (DAP) - exudative changes. With the use of cultured forms of bacteria, lethality is lower, morphological changes in the lungs correspond to the late manifestation of the DAP exudation phase (atelectasis, parenchymal distelectasis, hemorrhages and inflammatory lymphocytic infiltration of the interstitium). When uncultivated forms of P. aeruginosa and S. aureus bacteria are used, lethality is higher due to early changes in the phase of DAP exudation (alveolar edema, necrosis and desquamation of endothelial cells and type I alveocytes). Conclusions. In animals that survived this critical line (days 2-5), the process acquires a favorable course due to the transition from uncultivated to cultivated forms of bacteria, the morphological picture of lung damage corresponds to the late manifestation of the DAP exudation phase.

Subject of the study. Systemic morphological changes associated with the dynamics of pneumoconiosis. Objective of the study – to study in the experiment the features of the development of morphological changes in the organs and tissues in the conditions of prolonged exposure to the coal-rock dust on the body. Methods. Experiments were carried out on white laboratory male rats of the experimental and control groups. The animals of the experimental group underwent inhalation exposure to the coal-rock dust of the gas fatty type in an average concentration of 50 mg/m3 for 12 weeks in the priming chamber. For histological examination of the morphological changes in the internal organs in the rats of both groups the fragments of the lungs, bronchi, heart, liver and kidneys at different periods of the experiment were taken. Main results. Prolonged inhalation of the coal-rock dust leads to the development of morphological disorders, primarily the bronchopulmonary system, as well as the heart, liver and kidneys. The changes are formed from the moment of the impact of the damaging factor on the body and are characterized by phase development. The pneumoconiotic process is accompanied by the progressive development of microcirculatory disorders and the same type of pathological changes in the vessel walls of all organs under investigation, the extent of which is associated with the duration of exposure to coal-rock dust on the body. Area of application of the results. The results of the conducted studies broaden and deepen the understanding of the mechanisms of pneumoconiosis development. Defining the stages of morphological changes has theoretical and practical meaning for elaboration of the recommendations for determining the timing and methods of prevention and correction of disturbances caused by exposure to the coal-rock dust. Conclusions. New data have been obtained that indicate a systemic exposure to the coal-rock dust on the morphological state of the organs and tissues of the body.