THYROID CANCER INCIDENCE IN THE POPULATION OF UKRAINE AND ITS EPIDEMIOLOGICAL DETERMINANTS: IONIZING RADIATION AND ENDOCRINE DISRUPTORS. / ЧАСТОТА РАКУ ЩИТОПОДІБНОЇ ЗАЛОЗИ У НАСЕЛЕННЯ УКРАЇНИ ТА ЙОГО ЕПІДЕМІОЛОГІЧНІ ДЕТЕРМІНАНТИ: ІОНІЗУЮЧЕ ВИПРОМІНЮВАННЯ ТА ЕНДОКРИННІ РУЙНІВНИКИ.

OBJECTIVE: to estimate the risk of thyroid cancer incidence in the population of Ukraine in connection with its exposure to radioactive iodine fallout of Chornobyl origin and the use of pesticides in agricultural production in the country. OBJECT OF STUDY: Incidence rates of thyroid cancer in the population of Ukraine in 2001-2019, average regional radiation doses absorbed by the thyroid because of the Chornobyl accident, the volume of use of various groups of pesticides in the regions of Ukraine. RESEARCH METHODS: statistical, mathematical and cartographic. RESULTS: The study covering the period of 2001-2019, revealed significant temporal and regional differences in the thyroid cancer incidence in the population of the Ukraine regions in 2001-2019. The existence of a significant correlation between the thyroid cancer incidence and the amount of radiation exposure to the thyroid associated with the Chornobyl accident was established. The existence of a significant correlation between the thyroid cancer incidence and the degree of pesticide use intensity in agriculture in the Ukraine regions was established. A significant value of multiple correlation r = 0.5866 (p < 0.05) was found between the thyroid cancer incidence in Ukraine andthe average regional radiation doses and the pesticide use intensity in agricultural production in the country. CONCLUSIONS: A reliable value of the multiple correlation between the value of the average regional radiation exposure doses to the thyroid associated with the Chornobyl accident and the degree of pesticide use intensity in the national economy of Ukraine and the thyroid cancer incidence in the population was determined.

LATE ONCOLOGICAL AFTEREFFECTS OF RADIATION EXPOSURE CAUSED BY THE CHORNOBYL ACCIDENT. / VIDDALENI ONKOLOGIChNI NASLIDKY RADIATsIINOGO OPROMINENNIa, SPRYChYNENOGO AVARIIeIu NA ChORNOBYL'S'KII AES.

Studies of the longterm oncological consequences after the Chornobyl accident show a significant impact of radiation exposure on the cancer incidence rate in affected population in Ukraine. This is supported by the increased radiation risk of leukaemia in liquidators, which exceeds national population rates, and its value is comparable to the data on hibakushi, who were subjected to Abombings. For the first time in the cleanup workers cohort the radiation dependence of chronic lymphoid leukaemia was established. There are radiation associated risks of leukemia in children who have been exposed to radiation from the Chornobyl accident. There has been registered an increase of thyroid cancer incidence in children and adults (liquidators, evacuees from the 30km exclusion zone and residents of the most contaminated territories). There is an excess of breast cancer in female liquidators. The frequency of all forms of malignant neoplasms decreases over time but still exceeds national rates. Further monitoring of malignant neoplasms in the groups of affected population will allow evaluating the radiation risks of cancer forms whose radiationassociated manifestation is already known from previous studies or can be expected in the future.

Non-radiation risk factors for leukemia: A case-control study among chornobyl cleanup workers in Ukraine.

BACKGROUND: Occupational and environmental exposure to chemicals such as benzene has been linked to increased risk of leukemia. Cigarette smoking and alcohol consumption have also been found to affect leukemia risk. Previous analyses in a large cohort of Chornobyl clean-up workers in Ukraine found significant radiation-related increased risk for all leukemia types. We investigated the potential for additional effects of occupational and lifestyle factors on leukemia risk in this radiation-exposed cohort. METHODS: In a case-control study of chronic lymphocytic and other leukemias among Chornobyl cleanup workers, we collected data on a range of non-radiation exposures. We evaluated these and other potential risk factors in analyses adjusting for estimated bone marrow radiation dose. We calculated Odds Ratios and 95% Confidence Intervals in relation to lifestyle factors and occupational hazards. RESULTS: After adjusting for radiation, we found no clear association of leukemia risk with smoking or alcohol but identified a two-fold elevated risk for non-CLL leukemia with occupational exposure to petroleum (OR=2.28; 95% Confidence Interval 1.13, 6.79). Risks were particularly high for myeloid leukemias. No associations with risk factors other than radiation were found for chronic lymphocytic leukemia. CONCLUSIONS: These data - the first from a working population in Ukraine - add to evidence from several previous reports of excess leukemia morbidity in groups exposed environmentally or occupationally to petroleum or its products.

Quarter of century since the Chornobyl accident: сancer risks in affected groups of population. / Chvert'' stolittja pislja Chornobyl''s''koi' avarii': ryzyk raku v grupah postrazhdalogo naselennja.

Objective. The goal of this study was to define levels and dynamic trends of cancer incidence at whole and some separate sites in groups of Ukrainian population affected by the Chornobyl accident during a long period of observation. Materials and methods. Those groups were Chornobyl accident recovery operation workers (CRW) of 1986-1987 years of participation, evacuees from Prypyat town and 30-km zone and residents of the most contaminated territories of Ukraine. Analysis was carried out with the standard methods of descriptive epidemiology: calculation of crude, age-specific and age-adjusted incidence rates with standard errors and confidence intervals. Results, discussion and conclusions. This study showed that all cancer incidences exceeded the national level only in CRW group. Decrease of cancer incidence rate in the recent years might be caused by shortened average life expectancy in Ukrainian population, especially in males. Statistically significant increase of leukemia incidence in CRW group was registered as well. Besides, in all three main affected groups there was revealed significant excess of thyroid cancer. Irradiation of thyroid due to radioactive iodine fallouts might be a main cause of this phenomenon. Increase of thyroid cancer incidence was registered not only in children, but also in adolescents and adults. Appearance of excess thyroid cancer cases as an effect of radiation exposure tends to increase during the time. Significant excess was also revealed for breast cancer in female CRW group. Because latency period for different nosological forms of radiation-induced malignant tumors varies widely, profound attention in further studies should be drawn not only to thyroid, breast cancers and leukemia, but also to malignancies with longer latent period: lung, stomach, colon, ovary, urinary bladder, kidney cancer and multiple myeloma.

Multiple myeloma among Chornobyl accident clean-up workers - state and perspectives of analytical study.

UNLABELLED: The objective of the study was to analyze the Multiple Myeloma (MM) incidence in clean-up workers preparing the information background for consequent analytical study with a dose-dependent risk estimates. MATERIALS AND METHODS: The Cohort Database was linked to the Ukrainian National Cancer Registry to identify the MM cases in a cohort of 152 520 male clean-up workers. RESULTS: The 64 MM cases were identified in the studied Cohort for the 1987-2012 period. Fifty-eight of them were included to the preliminary incidence analysis accounting for the 10-years lag-period. According to the preliminary data analysis the MM incidence rate in studied clean-up workers Cohort did not exceed the corresponding rate in general population of Ukraine along the 21 years after the catastrophe. CONCLUSIONS: Standardized incidence ratio for the 2008-2012 period, that is 22-26 years after the accident, demonstrated the significant excess of MM incidence among male clean-up workers in comparison with general population of Ukraine of corresponding age and gender (SIR 1.61, 95% CI 1.01;2.21).

The Ukrainian-American study of leukemia and related disorders among Chornobyl cleanup workers from Ukraine: I. Study methods.

There are relatively few data on the risk of leukemia among those exposed to external radiation during cleanup operations after the Chornobyl nuclear accident, and results have not been consistent. To investigate this further, we assembled a cohort of 110,645 male cleanup workers from Ukraine and identified cases of leukemia occurring during the period 1986 to 2000. Detailed interviews were conducted and individual bone marrow doses estimated using a new time-and-motion method known as RADRUE described in companion paper II. For the initial analyses we used a nested case-control approach with a minimum of five controls per case, matched for year of birth, oblast (region) of registration, and residence. All identified cases were reviewed by an international panel of experts; 87 of 111 were confirmed. The dose-response analysis and results are given in companion paper III. As background, we describe herein the design, procedures, outcome of case finding and confirmation, control selection, dose estimation and interviewing of subjects.

[Informative value of the specialized registers in research of leukemia in Chernobyl accident liquidators in Ukraine].

The article considers the possibility of the use of current infrastructure of specialized population registers of Ukraine to study leukemia and other systemic blood diseases revealed in Chernobyl accident liquidators. Advantage and limitation of such registers in the use are discussed in the article. Ukrainian state register of people who suffered from Chernobyl accident and Ukrainian national cancer registers are the largest population registers in the country, which cover all the territory of Ukraine and contain information on each individual and may serve as source base for epidemiological studies. To solve issues on leukemia and other oncological diseases is recommended to use in complex data of specialized registers of Ukraine. It should be also taken into account necessity of using late registered cases and verifying registered diagnoses.

Selective form of an excitable membrane plasticity.

This work describes the change in an active electrogenesis of the command neurons responsible for defensive closure of a snail's pneumostome during elaborating, extinction and restoration of a classical conditioned defensive reflex to a tactile stimulus. Tactile stimulations applied to different parts of a snail's body served as a differential stimulus. As the biological value of a conditioned stimulus increases due to learning, the excitability of command neurons in response to conditioned stimulus rises. At the same time the neurons demonstrated a reduced excitability in response to a differentiating stimulus.

Active electrogenesis of command neurons of defense behavior of the snail during conditioning.

A change in the active electrogenesis of command neurons of the defensive closing of the spiracle of the edible snail during the development, extinction, and repeat development of a classical conditioned defense reflex in response to tactile stimulation is described in this study; the tactile stimulation of another point of the body served as the differential stimulus. As the biological significance of the conditional stimulus increased as the result of training, the excitability of the command neurons in response to this stimulus increased. At the same time, the neurons manifested reduced excitability in response to the differential stimulus. The possible mechanisms of the rapid reorganization of the excitability of the neurons and the functional significance of the change in the generation threshold of the AP are discussed.

[The active electrogenesis of the command neurons in the defensive behavior of the mollusk during conditioning]. / Aktivnyi élektrogenez komandnykh neironov oboronitel'nogo povedeniia molliuska pri obuslovlivanii.

In the paper changes of active electrogenesis of the command neurones of defensive closure of snail pneumostome at elaboration, extinction and repeated elaboration of classic conditioned defensive reflex to tactile stimulus was described; the tactile stimulation of other point of the body served as a differentiating stimulus. During the increase of biological significance of conditioned stimulus as a result of learning the stimulation of the command neurones in response to this stimulus was raised. At the same time the neurones showed decreased excitability in response to differentiating stimulus. Possible mechanisms of quick reconstruction of neurones excitability and functional value of PA generation threshold changes were discussed.

[Effects of dalargin on some parameters of peroxidation of liver lipids in experimental animals]. / Vliianie dalargina na nekotorye pokazateli perekisnogo okisleniia lipidov pecheni v éksperimente.

The cholestasis and pancreatitis model was studied experimentally in 144 white rats. The influence of intraperitoneal injections of dalargin on the level of lipid peroxidation and on xanthine oxidase activity of the liver tissues in periods of 1, 3 and 5 hours was investigated. During that period the activity of hepato-specific enzymes in the liver tissues and serum were investigated. The reduction of xanthine oxidase activity in all the periods after injection of dalargin was discovered, the level of malonic dialdehyde was reduced by 43.8% 3 hours later. Simultaneously, the increase of the level of histidase in liver tissues was discovered (on 104.3% and 56.3% after 3 and 5 hours accordingly) and later the tendency to decrease the activity in serum was observed.

[The antioxidant action of dalargin on the liver in experimental acute cholestasis]. / Antioksidantnoe deistvie dalargina na pechen' v usloviiakh ostrogo kholestaza v éksperimente.

Experiments were conducted on 182 rats with acute cholestasis to study the effect of intra-abdominal dalargin injection (10 mcg/kg) with the serotonin antagonist ketanserine (150 mg/kg) on xanthine oxidase (XO) activity and level of lipid peroxidation in the hepatic tissue and on the activity of the hepatospecific enzymes histidase and urokaninase in hepatic tissue and blood serum 1, 3, and 5 hours after the injection. Dalargin reduced XO activity by 32-37% in different periods after the injection, dalargin in combination with ketanserine--by 37-48%. Dalargin reduced the level of lipid peroxidation by 29-35%, and when combined with ketanserine--by 37-49%. The administration of dalargin reveals a distinct tendency towards reduction of the release of the hepatospecific enzymes histidase and urokanase into the blood and increase of their activity in the hepatic tissue. Dalargin with ketanserine produces a similar effect but of a higher degree. These data allow us to speak of the hepatoprotective effect of dalargin, which is potentiated by its injection together with ketanserine. It was found that dalargin (50 mcg/kg, intraperitoneally) increases the leu-enkephalin content in the hepatic tissue more than 3.5 fold one hour after injection.

[Experimental study of the hepatoprotective effect of transcranial transcutaneous electrostimulation and the synthetic analog of leu-enkephalin dalargin]. / Izuchenie v éksperimente gepatoprotektornogo deistviia transkranial'noi chreskozhnoi élektrostimuliatsii i sinteticheskogoanaloga lei-enkefalina dalargina.

Results obtained from the study of mechanisms of hepatoprotective effect of transcranial transcutaneous electrostimulation are cited (TTES). In experiments on cholestase and pancreatitis models in rats we studied hepatospecific enzymes i.e. histidase and urokininanse in blood and liver and membrane-linked enzyme 5'-nucleotidase in the liver tissue. We made three series of experiments: 1 - TTES + valium, 2 - synthetis hexapeptide (SH) - leuenkephaline analog; 3 - TTES + valium + SH. Results obtained from experiments showed that mechanisms of TTES hepatoprotective action are in part conditioned by endogenous opiopeptides mobilization which produced membranestabilizing effect on the hepatocyte. We concluded that in patients with hepatic pathology it was reasonable to combine the electroanesthesia with SH.