Mast cells are an important link in the immune system. They are involved in many pathological processes such as stress, inflammation, autoimmune processes and carcinogenesis. The purpose of the review is to summarize the data on the role of mast cells in carcinogenesis. Materials and methods. Review of available literature sources published in Elibrary and PubMed. Results. Tumor growth in the body is accompanied by immune system dysfunction and mast cell response. Mast cells are able to stimulate tumour growth through the secretion of proteases, angiogenic and growth factors, and at the same time have a tumour suppressive effect. The response of the mast cell population depends on the type of tissue from which the tumor is developing, the speed and stage of the process, the localization of the mast cells, and the combination of pro- and anti-tumor factors. During tumour development and growth, total degranulation of mast cells occurs. In addition, mast cells in normal and tumor tissue differ in structure. This article provides information on the role of mast cells in carcinogenesis. Conclusion. Thus, mast cells on the one hand positively affect tumor growth through the synthesis of proteases, growth and angiogenic factors, and on the other hand, act as inhibitors of malignant growth. The response of mastocytes directly depends on the tissue in which tumour develops, on its type and degree of malignancy, the stage of pathological process, localization of mast cells and the degree of their activation, as well as the total balance of pro- and antitumour effects.

Mast cells play an important role in many processes occurring in the human body. These include inflammation, allergic reactions, parasitic infections, carcinogenesis and others. Therefore, the detection of mast cells plays an important role in the diagnosis of pathological conditions. The purpose of the study is to summarize data on imaging methods of mast cells. Materials and methods. Review of available literature sources published in Elibrary and PubMed. Results. There are several major groups of methods for finding mast cells: histochemical, enzyme-linked histochemical and immunohistochemical. All are based on the ability to detect specific substances contained in mast cell granules. Histochemical methods include Unno, alcian blue and safranin staining of mast cells and others. The most modern method is mast cell visualisation using immunohistochemical reactions based on antigen-antibody reactions. Conclusion. This review presents the most common methods of mast cell staining, differing in difficulty of performance, specificity in relation to mast cells and staining cost.

The adrenal gland is one of the first organs to respond to external influences. Cortisol, with its important properties affecting the immune system, proliferation and apoptosis in various tissues, is a significant indicator of such a pathological process as malignant growth. Selenium is a powerful antioxidant having an immunomodulatory action and exhibiting anticarcinogenic effects. In this paper, we investigate adrenal morphofunctional changes under experimental carcinogenesis against the background of urethane and selenium administration by determining blood cortisol concentrations and studying the aggregate morphometric index of adrenal glands. The study revealed that carcinogen introduction imitates the adaptation syndrome stages in the organism and is accompanied by changes in the cortisol level and aggregate morphometric index. Maximal values of the studied parameters were detected after 1 month of exposure to carcinogen, which indicated the development of the alarm phase. A further decrease in the indices after 2 and 3 months down to the intact level indicates the development of the resistance stage. A sharp decrease in the indices after 6 months shows the exhaustion stage. An isolated course introduction of selenium leads to a reliable decrease in the aggregate morphometric index practically in all terms that indicates the stress-relieving influence of the microelement. The combined effects of selenium and carcinogen revealed a dropout of the alarm stage, but rapid elimination of the micronutrient from the body could not prevent the development of the exhaustion phase after 6 months.

Micro- and macroelements play a significant role in the unimpaired functioning of all organs and systems. Important essential trace elements include selenium, which plays a crucial role in many physiological processes, including immune responses. The purpose is to generalize available data on the effect of selenium on the functioning of various organs and systems of the human body. Materials and methods. This literature review presents data on the effect of selenium on the body, published in domestic and foreign literature sources. Results. Selenium belongs to essential trace elements; it is a part of various proteins and enzymes that have cytoprotective, antitumor, antimutagenic effects. In addition, selenium participates in the functioning of the body's endocrine, reproductive, immune and antioxidant systems, although it was previously considered one of the most toxic trace elements. Many studies have been devoted to the analysis of selenium's effect on the processes of carcinogenesis and prevention of the development of tumor processes of various localization. Selenium-containing enzymes play one of the leading roles in anti-carcinogenic action, as they take part in the antioxidant defense of the body, regulate apoptosis and cell proliferation, protect desoxyribonucleic acid from damage, affect the metabolism and detoxification of carcinogens. Conclusions. The study of selenium's antitumor effect is of the greatest interest at present, since the number of patients with oncopathology is increasing every year.

Macrophages are the key thymic cells that take part in the antigen-independent differentiation of T-lymphocytes and their further selection. The level of macrophages indicates changes in the functions of the organ under study. As an essential trace element, selenium is part of a variety of proteins and enzymes, which perform cytoprotective, antimutagenic, and anticancerogenic action. Selenium also plays a significant role in the functioning of the immune system, increasing the activity of natural killers, production of interleukins, and stimulation of phagocytosis. This study was aimed at investigating the response of thymic macrophages to the administration of selenium and a chemical carcinogen. During the experiment, an increase in the level of CD68-positive cells was revealed in all experimental animals receiving selenium and a carcinogen, as well as under their combined action. The observed effects were assumed to be related to the immune-stimulating effect of selenium.