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The paper deals with applying mathematical modeling to study tumor growth process and optimizing cancer treatment. A structured review of the studies devoted to this problem is given. The role of the cell life cycle in understanding the tumor growth and the mechanisms of cancer treatment is discussed. It is important that modern cancer treatment methods, in particular, chemotherapy and radiation therapy, affect both normal and tumor cells in certain stages of the life cycle and do not influence on cells in other stages. Cell life cycle description is given as well as the mechanisms that maintain and restore normal density of the cell population. A graph of cell life cycle stages and transitions is demonstrated. Dynamic mathematical model of proliferative homeostasis in the cell population is proposed, which takes into account the heterogeneity of cell populations by life cycle stages. The model is a system of differential equations with delays. The stationary state of the model is investigated, which allows to determine the parameters values for the normal cell population. The results of a numeric experiment is obtained, which is focused on the process of cell population density recovery after mass death of cells. As the experiment shows, after cell death, the densities of cells in different life cycle stages are restored to normal values, which corresponds to the concepts of proliferative homeostasis in cell populations.

Introduction. In endosurgery of the digestive tract, ‘cellular technologies’ are gaining popularity, including the use of blood components or blood cells with a haemostatic purpose. In this regard, the objective of the study is evaluation of the effectiveness of bleeding control and safety of resection of the hollow organs of the digestive tract in the experimental trauma models of the abdominal organs in laboratory animals. Materials and methods. The study was conducted in 20 mature male Chinchilla rabbits with the mean body mass of 2450 ± 210 g. All animals were divided into four experimental groups: the control group (without bleeding control); the group that received the infiltration of the wall of a hollow organ with saline; the group in which bleeding was controlled by argon plasma coagulation (APC), and the group wherein animals underwent haemostasis with autoplasma. Results. In the control group and the physiological saline group, no statistical difference was observed in the time of bleeding control. Autoplasma, due to preventive local administration, is more effective than APC and has a high haemostatic potential. Conclusion. Autoplasma has been found to be highly effective and safe for bleeding control in the gastrointestinal tract in the experimental model, which has paved the way for new possibilities for operations of various scales, including endoscopic operations.

The dynamics of blood fluorescence (FL) after intravenous injection of 5-fluorouracil (FU) to oncology patients taking chemotherapy were investigated. It was demonstrated that FU quenches FL of water solutions of tryptophan (Trp) (total concentration is 1.0 × 10 −5 mol L −1 , λ max = 353 nm) and plasma protein – albumin ( λ max = 340 nm) with the Stern–Volmer constants 16.4 × 10 3 L mol −1 and 52 L mol −1 , accordingly. The quenching of both Trp and albumin FL by 5-fluorouracil was concluded to proceed via the static mechanism of reversible photoinduced electron transfer (PET).

Breast cancer ranks first in the structure of oncological diseases in women in Russia and in the World. In recent years there have been numerous reports that the growth and progression of breast cancer and other tumors depend not only on their malignant potential, but also on stromal factors presented in the tumor microenvironment and intercellular interactions. The aim of our study was to evaluate intercellular interactions of the tissues surrounding the tumor, by means of determination of the locally interleukine profile. We have identified interleukine profiles of the axillary fatty tissue from the lesions and subcutaneous fat of the anterior chest wall, located at a maximum distance from the tumors, in stage IIa-IIIb breast cancer patients. As a result we came to a conclusion: the method based on the measurement of IL-1, IL-2, IL-6, IL-10 and а-TNF levels in the tissues and in the blood allows to evaluate the immune processes occurring in the tissues surrounding the tumor; adipose tissue of various areas of breast cancer patients differs significantly according to the level of interleukines, which indicates that different involvement of adipose tissue in various areas of the immune response; there is a dependence of the local immune status of armpit adipose tissue on the expression of ER, PgR, Her2/neu on the surface of breast cancer cells.