[THE ISSUE OF THE IMPACT OF RADIOACTIVE SUBSTANCES ON PUBLIC HEALTH AND COUNTERMEASURES FOR RADIATION EXPOSURE AS A GLOBAL PROBLEM].

The widespread use in today's world of radioactive sources d in energy, medicine, engineering and construction, for contaminant tracking and food sterilization increases the likelihood of accidental exposure. The use of ionizing radiation and radioactive elements can directly or indirectly cause life-threatening complications, such as oncopathology, radiation burns, and impaired immunity. Pollution of the environment with radioactive elements and depletion of the ozone layer also contribute to an increase in the level of radiation exposure. To protect the health of the population living in contaminated areas and consuming locally produced products, it is necessary to organize a system for monitoring radioactive damage, as well as special anti-radiation protective measures in the field of agriculture and forestry, hunting and fishing, and providing the population with food. The purpose of the study is to analyze modern scientific data on the effect of ionizing radiation on reproductive function and modern approaches aimed at correcting its violations. Bibliographic, information-analytical methods and methods of comparative analysis were used.

DNA Damage in Splenocytes of Mice Exposed to Secondary Radiation Created by 650 MeV Protons Bombarding a Concrete Shielding Barrier.

The proportion of splenocytes with a high level of DNA double-strand breaks was determined in mice exposed to primary and secondary radiation created by bombarding of a concrete barrier (thickness 20, 40, and 80 cm) by 650 MeV protons. The proportion of splenocytes with a high level of DNA double-strand breaks was assessed by flow cytometric analysis of γH2AX+ and TUNEL+ cells. It is shown that concrete barrier can significantly reduce primary proton radiation; the severity of negative biological effects in mice irradiated in the center of the proton beam decreased with increasing the thickness of this barrier. However, the spectrum of secondary radiation changes significantly with increasing the barrier thickness from 20 to 80 cm and the distance from central axis of the beam from 0 to 20 cm, and the proportion of the neutron component increases, which also causes negative biological effects manifesting in a significant (p<0.05) increase in the percentage of splenocytes with a high level of DNA damage in mice irradiated at a distance of 20 cm from the center of the proton beam and receiving relatively low doses (0.10-0.17 Gy).

Medical management: major lessons learned from the Chernobyl accident (the review).

Thirty-five years have passed since the moment of the disaster at the Chernobyl nuclear power plant. It is quite a sufficient period to assess the correctness of the organisation of medical care for victims, to summarise the results of monitoring the health status of various groups of persons involved in the accident, including its direct participants. Radiation from a massive source of relatively uniform gamma radiation and a heterogeneous source of beta radiation can cause affected people to develop acute radiation syndrome (ARS) of varying severity, including non-curable forms of the disease ARS developed in 134 patients; 28 patients from 134 with ARS died in a short time (100 d) after exposure. Among the patients whose disease ended in death, 2/3 of the outcome could be due to radiation skin lesions (19 people). Treatment of ARS varying severity, which was combined with common skin burns with beta radiation, requires long-term specialised treatment. The experience of treating this group of patients has demonstrated that the indications for bone marrow transplantation in the curable form of ARS are limited. The percentage of victims who have absolute indications for allogeneic bone marrow transplantation and in whom this procedure will lead to an improved prognosis for life is very small. Recovery of own myelopoiesis and survival are possible after whole-body irradiation from 6 to 8 Gy, which was found after rejection of haploidentical human leucocyte antigen transplantation, as well as in patients who did not use bone marrow transplantation due to the absence of a corresponding donor. Patients who have undergone ARS need lifelong medical supervision and the provision of necessary medical care.

ACUTE MYELOID LEUKEMIA, PROSTATE AND SKIN CANCER IN ACUTE RADIATION SYNDROME SURVIVOR AFTER THE 1986 CHERNOBYL NUCLEAR ACCIDENT: CASE REPORT.

The development of hemoblastosis is often associated with the influence of various genotoxic unfavorable factors, in particular, with the effect of ionizing radiation. This article presents a case report of acute myeloid leukemia (AML) in a patient who was involved in the 1986 accident at the Chernobyl Nuclear Power Plant and suffered an acute radiation syndrome of degree II severity. Based on clinical and cytogenetic dosimetry, the average absorbed radiation dose to the whole body was estimated to be 4.3 Gy. During long-term clinical follow-up (27 years), moderate transient instability of hematological parameters was observed: lymphocytosis, leukopenia and thrombocytopenia, which was associated with chronic viral hepatitis C. Further cytogenetic investigations demonstrated a very high frequency of translocations, up to 50 times background values, that persisted over 3 decades. In 2014, the patient was diagnosed and operated on for prostate cancer and received a course of radiotherapy (total fractionated local dose of 35 Gy) in May 2015. From December 2015 through April 2016, the patient experienced general weakness and developed progressive cytopenia. A diagnosis of AML, resulting from a myelodysplastic syndrome, was confirmed by abnormal complex clones detected in 38% of metaphases by the mFISH-method, along with other chromosomal rearrangements. The patient underwent several chemotherapy treatments for AML but eventually died of bilateral pneumonia in March 2017.

[FEDERAL CLINICAL PRACTICE GUIDELINES FOR THE DIAGNOSIS, PREVENTION AND TREATMENT OF PNEUMOCONIOSIS].

The purpose of development of this clinical practice guidelines was to provide evidence-based protocols that help the practitioner and the patient make the right decision for the health assessment, treatment and prevention of pneumoconiosis. Pneumoconiosis is the interstitial lung disease of occupational origin caused by prolonged inhalation of inorganic dust, characterized by chronic diffuse aseptic inflammation in lung tissue with the development of pulmonary fibrosis. Currently, thereare no treatment that provide a cure pulmonary fibrosis and changes in the dynamics of decline in lung function. Regular, individually tailored treatment should be directed to the pathogenic mechanisms and some clinical symptoms of pneumoconiosis, as well as the prevention of complications. To enhance the effect of pharmacotherapy is recommended to use non-drug therapies that enhance the functionality of the respiratory system.

[Slow Formation and Degradation of γH2AX Foci in Human Skin Fibroblasts Exposed to Low-Dose X-Ray Radiation].

It was shown that the kinetics of changes of γH2AX foci number (marker of DNA double-strand breaks) in human skin fibroblasts after exposure to low doses of X-ray radiation (20, 40 and 80 mGy) differs from that observed after exposure to medium-low doses (160 and 240 mGy). After exposure to 160 and 240 mGy the highest number of γH2AX foci was detected at 30 min after exposure (first experimental point) and further their decrease was observed. At the same time we observed a fast phase of repair (upto 4 h), in which there was a decrease of the foci amount to ~50-60% and a slow phase of repair (from 4 h to 24 h). After 24 h only ~3-5% of the foci amount observed at 30 min after irradiation was left. After exposure to low doses, the foci number did not decrease during 2 h and even 24 h after exposure their amount was ~25% from that observed at maximum points (1 h after irradiation at 40 and 80 mGy and 2 h after irradiation at 20 mGy).