INTENSITY OF OXIDATIVE PROCESSES IN BLOOD AND LEVEL OF APOPTOSIS IN BLOOD LYMPHOCYTES IN RADIOLOGISTS/X-RAY TECHNOLOGIES EXPOSED TO SMALL DOSES OF IONIZING RADIATION. / ІНТЕНСИВНІСТЬ ОКИСНИХ ПРОЦЕСІВ В КРОВІ ТА РІВЕНЬ АПОПТОЗУ В ЛІМФОЦИТАХ КРОВІ У РАДІОЛОГІВ/РЕНТГЕНОЛОГІВ, ЯКІ ЗАЗНАЮТЬ ВПЛИВУ МАЛИХ ДОЗ ІОНІЗУЮЧОГО ВИПРОМІНЮВАННЯ.

OBJECTIVE: to determine the presence of changes in peripheral blood parameters, characterizing its redox state, and the level of apoptosis of lymphocyte in radiologists/x-ray technologies who, due to their official duties, are exposed to small doses of ionizing radiation. OBJECT AND METHODS: The work was performed on blood samples of 45 professionals radiologists/x-ray technologies and 52 conventionally healthy individuals (control group). The content of malondialdehyde and sulfhydryl groups of proteins and peptides (-SH) in blood plasma was determined; catalase enzyme activity and the ratio of pro-antioxidant processes in hemolysates, the level of superoxide anion-radical (О2-) generation, the total production offree radical compounds (reactive forms of oxygen and nitrogen) and the level of apoptosis of peripheral blood lymphocytes (PBL). RESULTS: The content of malondialdehyde in the blood of professionals was increased by 1.49 times and the contentof -SH was decreased by 1.67 times compared to conventionally healthy individuals. An increase in the level of О2-production by 1.56 times was observed for PBL. The obtained results indicate a shift in the ratio between antioxidant and pro-oxidant processes towards the latter, which is confirmed by a 1.49-fold increase of this index. The levelfor PBL apoptosis was reduced by 1.35 times. For professionals, against the background of increased generation of О2-, a reliable direct correlation was observed between the indicator of apoptosis and the total production of free radical compounds, and between the latter and the level of apoptosis of lymphocytes, which was not noted for the conventionally healthy individuals group. CONCLUSION: A change in the ratio between pro- and antioxidant processes in the blood was found for professionals who are in contact with sources of ionizing radiation, which indicates the possibility of the development of oxidative stress, and the consequence of a reduced level of apoptosis of lymphocytes may be the danger of accumulating genetic damage in these cells.

ROLE OF CONTEMPORARY IMAGING METHODS IN RADIOTHERAPY PLANNING AND MONITORING OF GYNECOLOGICAL CANCER PATIENTS (REVIEW). / РОЛЬ СУЧАСНИХ МЕТОДІВ ВІЗУАЛІЗАЦІЇ У ПЛАНУВАННІ ПРОМЕНЕВОЇ ТЕРАПІЇ ТА МОНІТОРИНГУ ОНКОГІНЕКОЛОГІЧНИХ ХВОРИХ (огляд літератури).

Radiotherapy (RT) and radiation oncology are of essential role in the clinical treatment of cancer patients. The widely available imaging modalities such as diagnostic ultrasound, computer-assisted tomography, and contrast-enhanced MRI are used in clinical practice for diagnostics and management planning. Moreover, these methods are also used to monitor the treatment upon RT. However, some diagnostic issues cannot be sufficiently resolved by the simple use of standard morphological imaging. Thus, positron emission tomography is gaining an increasing clinical relevance in the management of cancer patients undergoing RT, as it allows to visualize and quantify the tumor features at a molecular level, such as tumor metabolism or receptor expression, beyond simple morphological patterns shown by the conventional imaging. This review focuses on the recent and current advances in imaging techniques, including PET imaging, in the diagnostics and planning of RT in some cancers, namely in cervical cancer.

CONTEMPORARY APPROACHES TO PROGNOSTICATION AND MANAGEMENT OF PELVIC RADIATION INJURIES IN GYNECOLOGICAL CANCER PATIENTS. / SUChASNI PIDKhODY DO PROGNOZUVANNIa TA LIKUVANNIa PROMENEVYKh UShKODZhEN' ORGANIV MALOGO TAZU PISLIa RADIOTERAPIÏ KhVORYKh ONKOGINEKOLOGIChNOGO PROFILIu.

BACKGROUND: Rapid development of radiotherapeutic techniques and implementation of radiation therapy (RT) nanotechnologies in practice, taking into account principles of radiobiology, ensures that the planned dose will bedelivered to the target volume with minimal irradiation of healthy tissues while maintaining the guaranteed RTquality. Therefore, further advance of RT involves not only implementation of the new technologies in radiationpractice, but also the intensive developments in fields of radiation medicine and clinical radiobiology. OBJECTIVE: search for optimal models of the high-energy (HDR - high dose rate) brachytherapy (BT) using the 192Irsource in comparison with effects of the reference gamma radiation from 60Co, thereby, to increase the effectivenessof chemoradiation therapy (CRT) of gynecological cancer patients (GCPs) with minimal radiation loads on criticalorgans and tissues in the tumor environment. The radiobiological study was aimed to determine the feasibility ofusing the transmembrane potential (TMP) and intensity of reactive oxygen species (ROS) production in peripheralblood lymphocytes (PBL) as predictors of radiosensitivity of non-malignant cells from the tumor environment or itsbed in order to minimize the RT complications in GCPs. MATERIALS AND METHODS: Patients (n = 115) with cancer stages II-III, T2-3N0-1M0 were managed with comprehensiveconservative treatment. Three groups of patients were selected depending on the applied HDR BT method against abackground of the administered chemosensitizing agents. Blood samples of GCPs (n = 24) before the RT initiationand of apparently healthy individuals (AHIs, i.e. the control group, n = 18) were taken for the radiobiologicalresearch. RESULTS: Review of the direct results of 60Co or 192Ir sources use in HDR BT and of the follow-up data showed theincreased tumor positive response in the main study groups after CRT course by respectively 16.6 % and 20.1 % incomparison with 60Со HDR BT administration. Concerning local reactions it was noted that grade II radiation reactions were almost absent in the main groups. According to the results of radiobiological studies, it was establishedthat TMP level in PBL of GCPs was 1.36 times higher than in AHIs. CONCLUSIONS: Thus, the emerging of late radiation injuries depended on the accuracy of of individual computer planning and correct reproduction of the planned RT course, timely correction of treatment programs, use of a complexof rational medical prophylaxis, severity of tumor process and concomitant disorders, as well as on the used type ofHDR radiation sources (192Ir and 60Co). Changes in TMP values and intensity of ROS production in PBL of GCPs in comparison with AHIs, and the high values of these parameters in PBL of individual patients are a rationale to specifythem as additional indicators characterizing the possibility of radiation complications before the RT planning.

FEATURES OF OXIDATIVE METABOLISM AND GENETIC DISORDERS IN PERIPHERAL BLOOD LYMPHOCYTES OF PATIENTS WITH PRIMARY CERVICAL CANCER.

BACKGROUND: The combination of chemo- and radiotherapy used as main treatment of locally advanced cervical cancer (CC) may lead to side effects in healthy cells, which undermine the effectiveness of treatment and quality of life. The assessment of damage level in healthy radiosensitive cells from the tumor environment before the treatment is important in order to predict and prevent remote side effects of radiation. AIM: To study the oxidative metabolism and genetic disorders in peripheral blood lymphocytes (PBL) of primary CC patients in order to evaluate the possibilities of predicting radiation complications based on the molecular and biological properties of PBL. MATERIALS AND METHODS: Peripheral blood samples were collected from 13 primary CC patients T1-4N0-1M0-1, and PBL were routinely isolated. The oxidative metabolism (mitochondrial trans-membrane potential, superoxide anion radical (О2•) generation, reactive oxygen species (ROS) production in PBL as well as the level of SH-groups in plasma and pro/antioxidant ratio in hemolysates were examined. The development of genetic instability was determined by estimation of DNA double-strand breaks (DNA-DSB), frequency and spectrum of chromosome aberrations and apoptosis. RESULTS: The marked increase in the intensity of О2• generation in PBL (1.5-fold), depletion of SH-groups content (1.6-fold) and a shift in the pro-antioxidant balance (1.4-fold) towards its prooxidant component were observed in the blood of primary CC patients as compared to healthy individuals. These oxidative stress related events were accompanied by an increase in the level of DNA-DSB (2.1-fold), apoptosis (3.5-fold) and frequency of cells with chromosome aberrations (3.9-fold). On the contrary, significant decrease in mitochondrial trans-membrane potential (2.0-fold) and ROS generation in PBL (4.0-fold) were detected. CONCLUSION: Preliminary data indicate a violation of redox processes regulation, a shift in the pro-antioxidant balance towards its pro-oxidant component, accompanied by an increase in the level of DNA damage, development of genetic instability and apoptotic death of blood lymphocytes in primary CC patients.

Fractionated low-dose radiation exposure potentiates proliferation of implanted tumor cells.

AIM: The purpose of this study is to test whether whole-body fractionated exposure of tumor-free animals to low doses of low-LET radiation (at the total delivered dose of 1.0 Gy of X-rays) is capable of potentiating growth of subsequently implanted tumor cells. MATERIALS AND METHODS: Adult male rats were fractionally exposed to low doses of X-rays (10 acute exposures with 0.1 Gy each and with a frequency of 1 exposure per 3 days). The next day after the last irradiation rats were implanted with Guerin carcinoma (GC) cells. On the 12th and 18th days after implantation of GC cells, animals were sacrificed, and the mass of tumors was measured by weighing them, although the kinetics of tumor growth was also examined by daily measurements of the dimensions of tumors. Cytotoxic effects in the bone marrow were assessed flow cytometrically in acridine orange-stained unfractionated bone marrow cells using the ratio of polychromatic erythrocytes (PCE) to normochromatic erythrocytes (NCE). RESULTS: In irradiated rats, tumors grew apparently faster than in unirradiated rats for up to 18 days after implantation of GC cells. On the 18th day after implantation of GC cells the average value of the mass of tumors in irradiated rats was 2.8-fold higher compared with the average value of the mass of tumors in unirradiated rats (p < 0.05). On this day post-implantation, the bone marrow in irradiated animals was 1.8-fold more suppressed (as evidenced by decreased PCE/NCE ratios) than that in animals that were irradiated, but were not implanted with GC cells (p > 0.05), and was 1.4-fold more suppressed than that in animals that were not irradiated, but were implanted with GC cells (p > 0.05). CONCLUSION: Fractionated irradiation of tumor-free animals with low doses of X-rays potentiates proliferation of subsequently implanted GC cells. This potentiation seems to be associated with radiation-induced impaired hematopoiesis.

Chromosomal radiosensitivity in Ukrainian breast cancer patients and healthy individuals.

AIM: Recent studies showed that increased chromosomal damage induced by ionizing radiation is observed among patients with different tumor types. The aim of the study was evaluation of chromosomal radiosensitivity in breast cancer (BC) patients (n = 37) and healthy women (n = 44). METHODS: Chromosomal radiosensitivity was assessed with G0 and G2 assay. For G0 assay lymphocytes were exposed in vitro to 1,5 Gy of X-rays before culture setting. For G2 assay lymphocytes were irradiated with 0,5 Gy of X-rays after 47 h of incubation. RESULTS: Significant differences in mean scores both of G0 and G2 assay between breast cancer patients and controls were observed indicating the increased chromosomal radiosensitivity of lymphocytes of cancer patients. 11% of healthy women and 38% of BC patients were determined to be radiosensitive with G2 assay. CONCLUSION: Obtained results support the concept of association between elevated individual G2 chromosomal radiosensitivity and predisposition to BC.

The long-range cytotoxic effect in tumor-bearing animals.

AIM: The relationship between cancer and patient health is still of great interest for experimental and clinical oncology. The tumor can adversely affect surrounding and distant tissues as well. However, effects of the tumor on distant tissues are much less studied than its effects on surrounding tissues. This study was aimed to test whether the tumor could trigger cytotoxic and/or genotoxic signals with respect to the distant proliferative tissue such as bone marrow. MATERIALS AND METHODS: Rats were subcutaneously implanted with Guerin carcinoma cells, and on the 12(th) and 18(th) days after implantation both cytotoxic and genotoxic effects were assessed by flow cytometry in acridine orange stained unfractionated bone marrow cells isolated from femur. The cytotoxic effect was assessed using ratios of the following cell populations: total nucleated cells (TNC)/total enucleated erythrocytes (TE); polychromatic erythrocytes (PCE)/normochromatic erythrocytes (NCE). The genotoxic effect was assessed by quantification of micronucleated PCE (MNPCE) within the population of PCE. RESULTS: A significant cytotoxic effect was observed in tumor-bearing animals on the 12(th) and 18(th) days after implantation (≈ 2-fold decrease in both TNC/TE and PCE/NCE ratios compared with corresponding parameters in control animals). There was also a genotoxic effect in these animals (a slight increase in the number of MNPCE), however, this effect was insignificant. The PCE/NCE ratio reversely correlated with the tumor weight which is suggestive of the link between erythropoietic cytotoxicity and tumor progression. CONCLUSION: Cytotoxic insult to the bone marrow is likely to be associated with the mechanism(s) triggered by distantly located tumors whose growth may correlate with the cytotoxic effect.

Effects of green and black tea biocomposites on endogenous synthesis, metabolism and genotoxic effect of carcinogenic N-nitrosodimethylamine.

AIM: To study the modifying effect of green and black tea biocomposites on endogenous synthesis and genotoxic action of the carcinogenic N-nitrosodimethylamine. METHODS: Green and black tea biocomposites were administered to the white inbred rats in vivo. Amidopyrine and sodium nitrite were used as N-nitrosodimethylamine precursors and 4-methylpyrazol as an inhibitor of its metabolism. N-nitrosodimethylamine (blood, daily urine and reaction mixture), nitrites and nitrates (daily urine) levels were measured. Genotoxic action was tested by formation of DNA single-strand breaks in hepatocytes. RESULTS: In in vitro system, biocomposites increased N-nitrosodimethylamine synthesis in neutral medium and decreased in acid conditions. In vivo, black tea biocomposite consumption resulted in enhanced background level of DNA single-strand breaks in rats hepatocytes and higher genotoxic effect upon administration of N-nitrosodimethylamine precursors. The levels of N-nitrosodimethylamine in blood and urine of experimental animals were increased after precursors' administration. In contrast, green tea biocomposite significantly decreased background level of DNA single-strand breaks. However, there was no protective action of this food supplement at the N-nitrosodimethylamine, precursors' administration. 4-methylpyrazol administration did not increase N-nitrosodimethylamine excretion in urine, while this effect was observed in control and black tea biocomposite groups. CONCLUSIONS: The effects of green tea and black tea biocomposites on N-nitrosodimethylamine synthesis in in vitro system are unidirectional and depend on biocomposites' concentration and acidity of the medium. Long-term consumption of black tea biocomposite resulted in intensification of endogenous N-nitrosodimethylamine synthesis and increased damage of the hepatocytes' DNA. As to the green tea biocomposite, the obtained results allow us to suggest that this biocomposite enhanced N-nitrosodimethylamine metabolism.