[Features of behavioral reactions of chronically irradiated mice in the raised crosswise labyrinth with various genetically determined radiosensitivity and possibilities of their modification by the fungal biopolymer complex].

Structural elements of the central nervous system--neurons, along with the higher neuroendocrine structures and the hypothalamus centres, show high sensitivity to a chronic action of low doses of ionizing radiation (IR) in view of their extreme enrichment by phospholipids and intensive supply by oxygen, creating favorable conditions for the development of oxidizing stress. Stressful influences cause negative emotions in the behaviour of animals manifested as fear or uneasiness. The study represents the results of comparative research into the behavioral reactions characterized by uneasiness in the Balb/c and C57bl/6 mice exposed to a chronic irradiation at low doses. The chitin-melanin-glucan complex from fungi Fomes fomentarius (ChMG) was approved as an adaptive agent. It has been shown that under identical conditions, deposition levels of radionuclides 137Cs and 90Sr are raised in mice with IR hypersensitivity--line Balb/c, in comparison with less radio sensitive mice--line C57bl/6. Simultaneously, Balb/c mice were observed to exhibit the signs of a more anxious behaviour in the new environment. Chronic external and internal radiation exposure to rare ionizing radiation at low doses promotes strengthening of anxiety and phobic reactions in mice with IR hypersensitivity. The use of ChMG in animals neutralized the increase in anxiety and phobic reactions after a prolonged irradiation, thus indicating the presence in ChMG of the anxiolitic activity along with the above mentioned powerful radiosorbent, antioxidant, gene protective and immunomodulatory properties.

Character of interaction between irradiated and non-irradiated cells in culture in diffusion chambers in vivo.

OBJECTIVE: Current investigation is devoted to determination of interaction type between the non-irradiated murine bone-marrow cells and irradiated microenvironment in cell culture in diffusion chambers in vivo. MATERIALS AND METHODS: To study the characteristics of interaction between the cells we implemented an original cultivation model with bone-marrow cells of intact Balb/c mice inserted in the diffusion chambers in peritoneum of irradiated animals (it provided the access of nutrients and signaling molecules from outside). RESULTS: As a result of investigations performed, we have determined the direct influence of microenvironment factors of irradiated mice organism on the non-irradiated bone-marrow cells. Thus, cultivation of the cells in the organism of non-irradiated mice revealed a low colony-forming activity due to the absence of additional growth factors release. At the same time an irradiation of the recipient mice and, to a lesser extent, a treatment by cytostatic agent cyclophosphamide increased the proliferative activity of bone-marrow cells in chambers, which indicated the pronounced impact of factors released by the cells as an effect of ionizing radiation. Influence of signaling molecules was realized through the wall of diffusion chamber, causing the stimulation of colony-forming activity. Moreover, we should mention that a direct contact between cells was not necessary for the delivery of a signal. CONCLUSIONS: Stimulating influence on the colony-forming activity of non-irradiated hematopoietic progenitor cells in diffusion chambers, which is performed by cellular and extra-cellular structures forming external microenvironment, is associated with the action of growth factors produced by irradiated cells and affecting non-irradiated cells through the chamber wall, which is impermeable for the cells but freely transmits diffusible molecules.

[Vascular reactivity and metabolism of the reactive oxygen species and nitrogen in effects of low doses of radiation].

The disturbance of endothelium-dependent and endothelium-independent vascular reactions of relaxation was registered in the preparations of aorta of radiosensitive BALB/c mice, exposed to chronic external gamma-irradiation (cumulative dose of 0.43 Sv). Low doses of radiation induced an intensive hydrolysis of membrane phospholipids by phospholipase A2, displayed by an increase in the level of eukosanoisds--LTC4 and TxB2, formed under effects of lipid oxidases (lipoxygenase and cyclooxygenase) at the same time with O2 generation. High doses of O2- can also be formed under the effect of low doses of radiation along xanthine oxidase pathway simultaneously with uric acid. In these conditions *OH-radical is formed not only at the expense of water radiolysis, which is observed under the effect of high doses, as well as along the two--NO-dependent and NO-independent--pathways. Significant increase in the content of lipid peroxidation products--dienic conjugates and valonic dialdehyde--in the organs of cardiovascular system is a confirmation of active generation of *OH and *NO2 under the effect of low doses of radiation. The latter induce significant changes in the pools of NO stable metabolites, which can cause disturbance of NO-dependent physiological functions of both heart and aorta. Significant decrease in the levels of nitrite and nitrozothiols in these conditions may result in an oxidative stress. In increased simultaneous generation of *O2- and NO they may bind and thus form a toxic substance peroxynitrite. This notion can be confirmed by the low doses of nitrite, which are formed spontaneously in the presence of molecular oxygen against the background of increased or control levels of nitrate, which is formed mainly at the degradation of peroxynitrite, i.e. at high levels of superoxide anion.

[Age-related characteristics of contractile vascular reactions and the content of oxygen free radicals and nitric oxide metabolites in BALB/c mice in conditions of alienation zone].

Peculiarities of changes of the endothelium-dependent and endothelium-independent vascular reactions of relaxation, and the content of oxygen free radicals and stable metabolites of nitric oxide (NO) were studied in the aorta preparations of BALB/c mice of the two age groups (6 and 18 months), which were born and lived in the Chernobyl alienation zone. The results obtained showed no endothelium-dependent reactions of aortal smooth muscles relaxation to acetylcholine and only partially impaired endothelium-independent reactions to sodium nitroprusside in animals of both age groups. There was a significant decrease in the content of high-molecular nitrosothiols (HMNT) in old animals, which may signify a depletion of NO depot in the aorta. A decrease of HMNT levels induced an increase of the shares of anion nitrite and low-molecular nitrosothiols (LMNT) in the total amount of endogenous donors of NO in the aorta of old animals. Exposure of old animals to low doses of radiation resulted in an over 3-fold increase of LMNT. In old mice the levels of oxygen active forms, superoxide and hydroxyl radicals increase, while the level of H2O2 remained unchanged.

[Immunological mechanisms of the radioprotective effects of ceruloplasmin]. / Immunologicheskie mekhanizmy radioprotektornogo deistviia tseruloplazma.

The aim of the work was to examine immunotropic features of celluroplasmine++ (Cp) and estimate its capacity as radioprotector. The pulse radiolysis method was used to set the mechanism of elementary reactions, which were responsible for antioxidant activity, and to demonstrate a particular role of reversible oxycomplexis, Cp...O2. Within in vitro test-systems the effects of Cp were examined on the model of interaction between lymphocytes from Shelter staff which constantly contacts with ionizing irradiation, and autologous erythrocytes in rosset-forming phenomenon (223 Shelter employees in comparison with 253 donors of Kyiv blood transfucion station). Expression of this Index in the presence of antigens with known poly-specificity was determined (antigens were taken from cortical and pyramid sections of kidney, liver, lungs, myocard, pancreatic gland, grey matter and aorta). Simultaneously the presence of analogous autoantibodies was determined (ELISA). It has been shown that Cp can reprogram the level of expression of immunovaluable receptors towards to norm. It has been also defined that Cp presence in blood irradiated in vitro (1-15 rem) promotes the masking of active centers of autoantibodies of different tissue specificity.

[Strategy and tactics of radiation protection of the personnel in light of future work on stabilization and reorganization of the "Shelter" compound into radiologically safe system]. / Strategiia i taktika radiologicheskoi zashchity personala v sviazi s predstoiashchimi rabotami po stabilizatsii i reorganizatsii ob''ekta "Ukrytie" v radiatsionno bezopasnuiu sistemu.

The research aim is to analyze the "Shelter" personnel work conditions and to estimate how these conditions specify radiological defense. "Shelter" object remains to be an accumulation of the open radiotoxic materials. It is expected that the usage of standard technologies in such conditions will be connected with the great dose-expense of external and internal irradiation. The significant quantity of the fuel dust (more 30 tonne according to uranium) and the extremely harmful microclimate conditions such as: aggressive radiochemical aerosols, exclusively artificial and obviously insufficient illumination, high humidity, discomfortable temperature regime, high ability of many working places to induce the emotional stress reaction in personnel are the specificity of "Shelter" object. The synergetic influence of radiofactor and "Shelter" object microclimate is very dangerous because of its ability to deteriorate significantly the personnel health up to acute stress reaction. In these cases there appear the episodes of the short disorders of orientation in the surrounding situation, paroxysmal consciousness disturbances which may become the nondirect reason of the overirradiation and growth of work traumatism. That's why the methods of the stress-reaction prophylaxis and improvement of the individual defense become extremely improvement for the "Shelter" object personnel. It was shown that the following medicines are perspective due to their adaptogenic and radioprotective abilities, such as: alpha-2-recombinant interferon, antiinflammatory, steroid, antioxidant and enterosorbtive preparations of biological nature.

[The effect of 2',5'-oligoadenylates on the expression of the cellular proto-oncogene c-myc during the development of Svec's leukemia in rats]. / Vliianie 2',5'-oligoadenilatov na ékspressiiu kletochnogo protoonkogena c-myc pri razvitii leikoza Shvetsa u krys.

The effects of 2',5'-oligoadenilates (2,5A) on the survival of Wistar rats inoculated with Svec leukemia cells and the proliferation of tumoral cells were investigated. An agreement between the expression of c-myc protooncogene and inhibition of leukemic cell proliferation by 2,5A was found.

[Study of physiological functions of human ceruloplasmin. The effect of ceruloplasmin on immunocytes in a normal state and in pathology]. / Issledovanie fiziologicheskikh funktsii tseruloplazmina cheloveka. Vliianie tseruloplazmina na immunotsity v norme i pri patologii.

The immunomodulating effect of ceruloplasmin (CP) on the major components of the immunocompetent system of the organism--the natural resistance system and the specific immune response--has been established. CP can exert various influences on the level of expression of specific markers of T- and B-lymphocytes (as determined by various modifications of the rosette-forming test), on the phagocytic activity of neutrophils and monocytes as well as on the activity of "respiratory burst" enzymes. CP modulation was found to depend predominantly on the initial level of the immunological parameters to be determined, i. e., on the extent of immune inflammation in human patients. Thus, it was found that CP not only plays the roles of an antioxidant and a copper-transporting protein, but is also capable to interact with immunocytes, altering their biological activities. The observed immunotropicity of CP, its ability to directly interact with immunocytes and to model the immune function at the cell level provides evidence for the existence of a universal molecular language of information exchange between the macroorganism cells of various nature and origin.

[Antibody-dependent cell cytotoxicity and spontaneous cytotoxicity of peripheral blood lymphocytes of organ recipients and cells infiltrating the kidney allogeneic transplant]. / Antitelozavisimaia i spontannaia tsitotoksichnos't limfotsitov peri- fericheskoi krovi retsipientov i kletok, infi'ltrirovavshikh pochechnyi allotransplant.

It is supposed that determination of antibody-dependent cellular-mediated cytotoxicity and spontaneous cellular-mediated cytotoxicity in the peripheral blood is non-informative for early diagnosis of acute rejection crisis. Activity of K- and NK-cells in peripheral blood is observed to increase during a peak of the rejection crisis. While studying cellular infiltrate obtained from the transplanted kidney, activity of K- and NK-cells is shown to considerably increase in the rejected transplants, which can testify that they contribute much in the loss of the allotransplant function.

[Activity of natural killer cells in patients with testicular germ cell tumors]. / Aktivnost' estestvennykh killernykh kletok u bol'nykh germinativnymi opukholiami iaichka.

The level of activity in natural killer cells (mononuclears) of peripheral blood relative to 51C-labelled K-562 cells is found to be significantly lower in patients with germinative testicle tumours than in donors. At the same time neither mononuclears of the peripheral blood nor those isolated from the tumour tissue practically lyse tumour tissue cells. The higher activity of natural killer cells relative to K-562 cells corresponds to the higher immunocellular infiltration of the tissue from nonseminomatous tumours.