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.
Oncopathology is one of the main mortality causes in the population. The immediate cause of death in a patient with cancer is metastatic spreading. The study of this pathological process is difficult due to asymptomatic course of the metastatic process, non-specificity of the main clinical analyses, impossibility of in-life studying the process of metastatic spreading. For this reason, laboratory models of metastatic spreading are being investigated, which can be connected both with direct introduction of tumor strains into the organ and with the development of metastases during experimental carcinogenesis. The issue of studying the endocrine system and its influence on the processes of metastatic spreading remains relevant. One of the organs that react to changes in the internal environment is the adrenal glands. The adrenal cortex plays an important role in the body's homeostasis, controlling the amount of cortisol, aldosterone and sex hormones (androgens and a small amount of estrogens), while the adrenal medulla controls stress reactions by discharging adrenaline and norepinephrine. Each of the hormones synthesized by the adrenal glands is somehow involved in the processes of carcinogenesis and metastatic spreading. Thus, cortisol, one of the hormones formed in the adrenal cortex, has a pronounced immunosuppressive effect, it affects the rate of cell proliferation, angiogenesis, differentiation and apoptosis, has a destructive effect on connective tissue. An increase in catecholamines in the blood leads to the damage to biological membranes, which stimulates adhesion and extravasation of tumor cells. In addition, catecholamines stimulate lymphoproliferation. Sex hormones affect not only hormone-dependent tumors of the reproductive system by stimulating cell growth, enhancing uncontrolled cell proliferation and angiogenesis, but tumors of other organs as well. Aldosterone, acting on the vascular wall, promotes the penetration of tumor cells into the vascular bed and their spread throughout the body.
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.
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.
In 2020 the pandemic of a new coronavirus infection spread in almost all countries of the world. The danger of this infection lies in the damage to the lungs, which can lead to fatal outcomes. The success of treatment is largely determined by the early diagnosis of the disease and its timely treatment. In order to find the ways of early laboratory diagnosis of coronavirus infection, we studied changes in peripheral blood indicators, coagulograms and C-reactive protein in 56 outpatient patients with mild course of coronavirus infection, whose average age was 49±2 years (among them, 23.2% were men and 66.8% were women). In all patients, coronavirus infection was confirmed by the detection of SARS-CoV-2 RNA by polymerase chain reaction (PCR) in nasopharyngeal or oropharyngeal smears. Signs of lung damage were detected in 66% of patients according to computed tomography findings. The number of red blood cells and the level of hemoglobin in all patients were normal. In 7% of patients, thrombocytopenia was detected, in 5.3% of patients – thrombocytosis. The most pronounced changes are foundin the leucoformula and indicators of the blood coagulation system. In 12.5% of patients without signs of viral pneumonia, leukocytosis was detected. All cases of leukopenia were noted only against the background of lung damage, at this, in 16% lymphopenia was found, 43% had relative lymphocytosis. The coagulogram of more than half of the patients with pneumonia showed shortening of blood clotting in the activated partial thromboplastin time (APTT) test, an increase in prothrombin index(PI) and the content of fibrinogen. The level of C-reactive protein was increased in only a quarter of patients with mild lung damage. Thus, changes in the leucoformula against the background of a tendency to hypercoagulation in blood clotting indicators should cause doctors' apprehensive attitude when treating a patient with clinical symptoms similar to COVID-19.
One of the main problems of modern medicine is cancer, which is the second leading cause of death after cardiovascular disease. Malignant neoplasms have been known for a long time; however, their study still presents significant difficulties. Modeling of malignant processes in animals allow researchers to study tumors and the main patterns of malignant growth characteristic of animals and humans. The main cause of death in malignant neoplasms is the process of metastasis formation, which remains to be understood in detail. The study of metastatic processes is one of the most important tasks of oncology. To this end, various models of tumor metastasis are created. The article reviews literature data on the most popular models of metastasis in experimental conditions. The advantages and disadvantages of the main approaches to modeling metastasis are evaluated.
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