RADON IN MINES OF KRYVYI RIH IRON ORE BASIN IN UKRAINE.

The first studies of radiation exposure in old mines of Kryvyi Rih Iron Ore Basin (Kryvbas) began relatively recently, about 20 years ago. The results of these studies have shown that the problem of radon is present in the major part of the Basin mines. In 6 of 8 mines tested, an excess of radiation safety standards for the equilibrium equivalent decay products concentration (EEC) of Radon-222 was observed. According to the sum of the main measured parameters of radiation situation, a preliminary assessment of doses to underground workers was made and a classification of the Basin mines according to radiation danger was developed. Results of the recent radiation surveys of these mines are shown in this article. Data on the incidence of lung cancer among the miners are presented and classified into age groups. Measures to improve the radiation situation in the mines of Kryvbas are considered.

RADIATION PROTECTIVE ACTIVITY DURING IMPLEMENTATION OF THE STATE PROGRAM FOR THE PROTECTION OF POPULATION OF ZHOVTI VODY TOWN.

The town of Zhovti Vody is a 'capital' of uranium mining and processing industry of Ukraine. The mining and processing of uranium has been carried out in this area for more than 60 y. During this period, due to increasing production activities, the town has grown significantly. As a result of production activities and also due to the human factor, the territory of the town was contaminated by radioactive rocks. In addition, out of ignorance, radioactive rocks were used in the construction of houses and roads. To normalize the radiation situation in the town, a targeted State Programme was adopted in 2003 for a period of 10 y. In 2013, the Programme was subsequently extended until 2022. In accordance with this Programme, decontamination of the urban territory, measurements of radon isotopes in houses and anti-radon reconstructions of the premises have been performed. The results of these works are described in this article.

[VIOLATION OF THE PROOXIDANT-ANTIOXIDANT BALANCE IN THE SPLEEN TISSUE UNDER EXPERIMENTAL CARCINOGENESIS].

This study was devoted to the investigation of antioxidant homeostasis in spleen tissue of white rats in the dynamics of development of colon adenocarcinoma induced by the introduction of sym-dimethylhydrazine (DMH). The effectiveness of the antioxidant barrier (Cu,Zn-superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, reduced glutathione) and oxidative damage products (TBARS, advanced oxidation protein products, diene and triene conjugates, Schiff bases) were measured in the homogenate of spleen tissue. A violation of the redox balance due to the accumulation of lipid peroxidation products, a decrease in the activity of antioxidant enzymes and antioxidant mediators of non-enzymatic nature was established. The development of oxidative stress leads to disruption of the synthesis of glutathione peroxidase and glutathione reductase in the endoplasmic reticulum, i.e., to inhibition of the functional activity of the glutathione-dependent unit of the antioxidant system. DMH-induced carcinogenesis is associated with enzymatic/non-enzymatic redox imbalance as well as increased oxidative damage to proteins and lipids. Evaluation of redox biomarkers can be potential diagnostic indicator of colon adenocarcinoma advancement.

SEARCH AND MAPPING OF THE OLD BURIED TAILINGS WITH RADIOACTIVE WASTES AT THE URBAN TERRITORY.

The article presents results of investigation on search and mapping of the old buried tailings with radioactive wastes on the territory of Kamianske City. For solving the problem used complex of methods. These methods are as follows: soil-gas 222Rn measurement and measurement of 222Rn flux density from the ground surface, gamma-radiation survey, prospecting drilling, gamma-ray logging and laboratory analysis of radionuclides. The leading method in this complex was the method of soil-gas 222Rn measurement. Using this method location of the tailings has been precisely defined. The tailings boundaries have been contoured in the plan. Other methods permitted to define such parameters as thickness of the wastes, their volume (~330 000 m3), radionuclide and chemical composition. It was found that radioactive residues occur at a depth from 2 to 11 m and contain in its composition 226Ra, 210Pb and 210Po in the range from 8370 to 37 270 Bq kg-1.

High resolution SEM imaging of gold nanoparticles in cells and tissues.

The growing demand of gold nanoparticles in medical applications increases the need for simple and efficient characterization methods of the interaction between the nanoparticles and biological systems. Due to its nanometre resolution, modern scanning electron microscopy (SEM) offers straightforward visualization of metallic nanoparticles down to a few nanometre size, almost without any special preparation step. However, visualization of biological materials in SEM requires complicated preparation procedure, which is typically finished by metal coating needed to decrease charging artefacts and quick radiation damage of biomaterials in the course of SEM imaging. The finest conductive metal coating available is usually composed of a few nanometre size clusters, which are almost identical to the metal nanoparticles employed in medical applications. Therefore, SEM monitoring of metal nanoparticles within cells and tissues is incompatible with the conventional preparation methods. In this work, we show that charging artefacts related to non-conductive biological specimen can be successfully eliminated by placing the uncoated biological sample on a conductive substrate. By growing the cells on glass pre-coated with a chromium layer, we were able to observe the uptake of 10 nm gold nanoparticles inside uncoated and unstained macrophages and keratinocytes cells. Imaging in back scattered electrons allowed observation of gold nanoparticles located inside the cells, while imaging in secondary electron gave information on gold nanoparticles located on the surface of the cells. By mounting a skin cross-section on an improved conductive holder, consisting of a silicon substrate coated with copper, we were able to observe penetration of gold nanoparticles of only 5 nm size through the skin barrier in an uncoated skin tissue. The described method offers a convenient modification in preparation procedure for biological samples to be analyzed in SEM. The method provides high conductivity without application of surface coating and requires less time and a reduced use of toxic chemicals.

Strontium hexaferrite nanomagnets suspended in a cosmetic preparation: a convenient tool to evaluate the biological effects of surface magnetism on human skin.

BACKGROUND/PURPOSE: Magnetic therapy has been popular for ages, but its therapeutic abilities remain to be demonstrated. We aimed to develop a homogeneous, stable dispersion of magnetic nanoparticles in a skin-care preparation, as a tool to analyze the biological and physiological effects of superficial magnetism in skin. METHODS: SrFe(12)O(19) nanoparticles were generated by ultrasound, dispersed in glycerol, stabilized in Dermud cream and permanently magnetized. The magnetic cream was applied on the epidermis of human skin organ cultures. The effects on UV-induced cell toxicity, apoptosis and inflammatory cytokine expression were analyzed. A clinical test was performed to check skin moisturization. RESULTS: Nanomagnets were found to be homogenously and stably dispersed. After magnetization, the preparation generated a magnetic field of 1-2 G. Upon cream application, no cytotoxicity and no impairment of cellular vitality were found after 24 and 48 h, respectively. The anti-apoptotic and anti-inflammatory properties of Dermud were not modified, but its long-term effect on moisturization in vivo was slightly increased. CONCLUSION: Nanomagnetic Dermud cream can be used as a tool to analyze the biological effects of nanomagnets dispersed on the skin surface at the cellular and molecular levels, thus allowing to explore the possible therapeutic uses of superficial magnetism for skin care.

Changes in protein kinase C during vitellogenesis in the crayfish Cherax quadricarinatus--possible activation by methyl farnesoate.

During ovarian maturation in the crayfish Cherax quadricarinatus, changes in ovarian protein kinase C (PKC) isoenzymes take place in parallel to yolk accumulation (as shown by immunoblot analysis). Significant changes were recorded in the amounts of specific isoenzymes and in their distribution between the cytosol and the membranes. Ovarian maturation was accompanied by the appearance of high- and low-molecular-weight immunoreactive PKC isoenzyme species. Among the isoenzymes tested, PKC alpha was the most clearly activated during ovarian maturation, as shown by significant translocation from the cytosol to the particulate fraction and the appearance of high-molecular-weight species. Moreover, a similar picture was obtained in the ovaries of intersex individuals upon induction of secondary vitellogenesis by androgenic gland ablation. Immunohistological staining showed PKC alpha to be localized mainly in the cytosol of premature oocytes, whereas in later maturation stages, it was concentrated around the nucleus in a vesicular structure and in the oocyte membrane. In secondary vitellogenic stages, PKC was localized in the plasma membrane and apparently in follicular cells. In addition, its activity was demonstrated by in vitro phosphorylation assays of a crayfish ovarian homogenate. Activation of total PKC phosphorylation of histone, an external substrate, was induced by phosphatidylserine plus 12-O-tetradecanoylphorbol-13-acetate (TPA) or methyl farnesoate. Both TPA and methyl farnesoate stimulated activation of PKC alpha in organ culture, causing its translocation from the cytosol to the membranes and inducing autophosphorylation of threonine residues. The changes in PKC isoenzymes during ovarian maturation in the crayfish suggest their involvement in this process as well as a possible regulatory role for methyl farnesoate through a direct effect on some PKC isoenzymes.