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PubMed | University of Miami, Burnasyan Federal Medical Biophysical Center, Institute for Nuclear Problems, University of California at San Francisco and 2 more.
Type: Journal Article | Journal: PloS one | Year: 2015

The excess incidence of thyroid cancer in Ukraine and Belarus observed a few years after the Chernobyl accident is considered to be largely the result of 131I released from the reactor. Although the Belarus thyroid cancer prevalence data has been previously analyzed, no account was taken of dose measurement error.We examined dose-response patterns in a thyroid screening prevalence cohort of 11,732 persons aged under 18 at the time of the accident, diagnosed during 1996-2004, who had direct thyroid 131I activity measurement, and were resident in the most radio-actively contaminated regions of Belarus. Three methods of dose-error correction (regression calibration, Monte Carlo maximum likelihood, Bayesian Markov Chain Monte Carlo) were applied.There was a statistically significant (p<0.001) increasing dose-response for prevalent thyroid cancer, irrespective of regression-adjustment method used. Without adjustment for dose errors the excess odds ratio was 1.51 Gy- (95% CI 0.53, 3.86), which was reduced by 13% when regression-calibration adjustment was used, 1.31 Gy- (95% CI 0.47, 3.31). A Monte Carlo maximum likelihood method yielded an excess odds ratio of 1.48 Gy- (95% CI 0.53, 3.87), about 2% lower than the unadjusted analysis. The Bayesian method yielded a maximum posterior excess odds ratio of 1.16 Gy- (95% BCI 0.20, 4.32), 23% lower than the unadjusted analysis. There were borderline significant (p = 0.053-0.078) indications of downward curvature in the dose response, depending on the adjustment methods used. There were also borderline significant (p = 0.102) modifying effects of gender on the radiation dose trend, but no significant modifying effects of age at time of accident, or age at screening as modifiers of dose response (p>0.2).In summary, the relatively small contribution of unshared classical dose error in the current study results in comparatively modest effects on the regression parameters.

Zablotska L.B.,University of California at San Francisco | Bazyka D.,National Research Center for Radiation Medicine | Lubin J.H.,U.S. National Institutes of Health | Gudzenko N.,National Research Center for Radiation Medicine | And 16 more authors.
Environmental Health Perspectives | Year: 2013

Background: Risks of most types of leukemia from exposure to acute high doses of ionizing radiation are well known, but risks associated with protracted exposures, as well as associations between radiation and chronic lymphocytic leukemia (CLL), are not clear. Objectives: We estimated relative risks of CLL and non-CLL from protracted exposures to low-dose ionizing radiation. Methods: A nested case-control study was conducted in a cohort of 110,645 Ukrainian cleanup workers of the 1986 Chornobyl nuclear power plant accident. Cases of incident leukemia diagnosed in 1986-2006 were confirmed by a panel of expert hematologists/hematopathologists. Controls were matched to cases on place of residence and year of birth. We estimated individual bone marrow radiation doses by the Realistic Analytical Dose Reconstruction with Uncertainty Estimation (RADRUE) method. We then used a conditional logistic regression model to estimate excess relative risk of leukemia per gray (ERR/Gy) of radiation dose. Results: We found a significant linear dose response for all leukemia [137 cases, ERR/Gy = 1.26 (95% CI: 0.03, 3.58]. There were nonsignificant positive dose responses for both CLL and non-CLL (ERR/Gy = 0.76 and 1.87, respectively). In our primary analysis excluding 20 cases with direct in-person interviews < 2 years from start of chemotherapy with an anomalous finding of ERR/Gy = -0.47 (95% CI: < -0.47, 1.02), the ERR/Gy for the remaining 117 cases was 2.38 (95% CI: 0.49, 5.87). For CLL, the ERR/Gy was 2.58 (95% CI: 0.02, 8.43), and for non-CLL, ERR/Gy was 2.21 (95% CI: 0.05, 7.61). Altogether, 16% of leukemia cases (18% of CLL, 15% of non-CLL) were attributed to radiation exposure. Conclusions: Exposure to low doses and to low dose-rates of radiation from post-Chornobyl cleanup work was associated with a significant increase in risk of leukemia, which was statistically consistent with estimates for the Japanese atomic bomb survivors. Based on the primary analysis, we conclude that CLL and non-CLL are both radiosensitive.

Drozdovitch V.,U.S. National Cancer Institute | Minenko V.,Institute for Nuclear Problems | Khrouch V.,Burnasyan Federal Medical Biophysical Center | Leshcheva S.,Republican Research Center for Radiation Medicine and Human Ecology | And 10 more authors.
Radiation Research | Year: 2013

The U.S. National Cancer Institute, in collaboration with the Belarusian Ministry of Health, is conducting a study of thyroid cancer and other thyroid diseases in a cohort of about 12,000 persons who were exposed to fallout from the Chernobyl accident in April 1986. The study subjects were 18 years old or younger at the time of exposure and resided in Belarus in the most contaminated areas of the Gomel and Mogilev Oblasts, as well as in the city of Minsk. All cohort members had at least one direct thyroid measurement made in April-June 1986. Individual data on residential history, consumption of milk, milk products and leafy vegetables as well as administration of stable iodine were collected for all cohort members by means of personal interviews conducted between 1996 and 2007. Based on the estimated 131I activities in the thyroids, which were derived from the direct thyroid measurements, and on the responses to the questionnaires, individual thyroid doses from intakes of 131I were reconstructed for all cohort members. In addition, radiation doses to the thyroid were estimated for the following minor exposure pathways: (a) intake of short-lived 132I, 133I and 132Te by inhalation and ingestion; (b) external irradiation from radionuclides deposited on the ground; and (c) ingestion intake of 134Cs and 137Cs. Intake of 131I was the major pathway for thyroid exposure; its mean contribution to the thyroid dose was 92%. The thyroid doses from 131I intakes varied from 0.5 mGy to almost 33 Gy; the mean was estimated to be 0.58 Gy, while the median was 0.23 Gy. The reconstructed doses are being used to evaluate the risk of thyroid cancer and other thyroid diseases in the cohort. © 2013 by Radiation Research Society. All rights of reproduction in any form reserved.

Drozdovitch V.,U.S. National Cancer Institute | Minenko V.,Institute for Nuclear Problems | Golovanov I.,Burnasyan Federal Medical Biophysical Center | Khrutchinsky A.,Institute for Nuclear Problems | And 8 more authors.
Radiation Research | Year: 2015

Deterministic thyroid radiation doses due to iodine-131 (131I) intake were reconstructed in a previous article for 11,732 participants of the Belarusian-American cohort study of thyroid cancer and other thyroid diseases in individuals exposed during childhood or adolescence to fallout from the Chernobyl accident. The current article describes an assessment of uncertainties in reconstructed thyroid doses that accounts for the shared and unshared errors. Using a Monte Carlo simulation procedure, 1,000 sets of cohort thyroid doses due to 131I intake were calculated. The arithmetic mean of the stochastic thyroid doses for the entire cohort was 0.68 Gy. For two-thirds of the cohort the arithmetic mean of individual stochastic thyroid doses was less than 0.5 Gy. The geometric standard deviation of stochastic doses varied among cohort members from 1.33 to 5.12 with an arithmetic mean of 1.76 and a geometric mean of 1.73. The uncertainties in thyroid dose were driven by the unshared errors associated with the estimates of values of thyroid mass and of the 131I activity in the thyroid of the subject; the contribution of shared errors to the overall uncertainty was small. These multiple sets of cohort thyroid doses will be used to evaluate the radiation risks of thyroid cancer and noncancer thyroid diseases, taking into account the structure of the errors in the dose estimates. © 2015 by Radiation Research Society.

Khrutchinsky A.,Institute for Nuclear Problems | Drozdovitch V.,U.S. National Cancer Institute | Kutsen S.,Institute for Nuclear Problems | Minenko V.,Belarusian Medical Academy of Post Graduate Education | And 4 more authors.
Applied Radiation and Isotopes | Year: 2012

This paper presents results of Monte Carlo modeling of the SRP-68-01 survey meter used to measure exposure rates near the thyroid glands of persons exposed to radioactivity following the Chernobyl accident. This device was not designed to measure radioactivity in humans. To estimate the uncertainty associated with the measurement results, a mathematical model of the SRP-68-01 survey meter was developed and verified. A Monte Carlo method of numerical simulation of radiation transport has been used to calculate the calibration factor for the device and evaluate its uncertainty. The SRP-68-01 survey meter scale coefficient, an important characteristic of the device, was also estimated in this study. The calibration factors of the survey meter were calculated for 131I, 132I, 133I, and 135I content in the thyroid gland for six age groups of population: newborns; children aged 1yr, 5yr, 10yr, 15yr; and adults. A realistic scenario of direct thyroid measurements with an "extended" neck was used to calculate the calibration factors for newborns and one-year-olds. Uncertainties in the device calibration factors due to variability of the device scale coefficient, variability in thyroid mass and statistical uncertainty of Monte Carlo method were evaluated. Relative uncertainties in the calibration factor estimates were found to be from 0.06 for children aged 1yr to 0.1 for 10-yr and 15-yr children. The positioning errors of the detector during measurements deviate mainly in one direction from the estimated calibration factors. Deviations of the device position from the proper geometry of measurements were found to lead to overestimation of the calibration factor by up to 24 percent for adults and up to 60 percent for 1-yr children. The results of this study improve the estimates of 131I thyroidal content and, consequently, thyroid dose estimates that are derived from direct thyroid measurements performed in Belarus shortly after the Chernobyl accident. © 2012.

Buzdin A.A.,Pathway Pharmaceuticals | Buzdin A.A.,Moscow Institute of Physics and Technology | Zhavoronkov A.A.,Pathway Pharmaceuticals | Zhavoronkov A.A.,Moscow Institute of Physics and Technology | And 7 more authors.
Frontiers in Genetics | Year: 2014

We propose a new biomathematical method, OncoFinder, for both quantitative and qualitative analysis of the intracellular signaling pathway activation (SPA). This method is universal and may be used for the analysis of any physiological, stress, malignancy and other perturbed conditions at the molecular level. In contrast to the other existing techniques for aggregation and generalization of the gene expression data for individual samples, we suggest to distinguish the positive/activator and negative/repressor role of every gene product in each pathway. We show that the relative importance of each gene product in a pathway can be assessed using kinetic models for "low-level" protein interactions. Although the importance factors for the pathway members cannot be so far established for most of the signaling pathways due to the lack of the required experimental data, we showed that ignoring these factors can be sometimes acceptable and that the simplified formula for SPA evaluation may be applied for many cases. We hope that due to its universal applicability, the method OncoFinder will be widely used by the researcher community. © 2014 Buzdin, Zhavoronkov, Korzinkin, Venkova, Zenin, Smirnov and Borisov.

Yarmoshenko I.V.,Russian Academy of Sciences | Vasilyev A.V.,Russian Academy of Sciences | Onishchenko A.D.,Russian Academy of Sciences | Kiselev S.M.,Burnasyan Federal Medical Biophysical Center | Zhukovsky M.V.,Russian Academy of Sciences
Radiation Protection Dosimetry | Year: 2014

Modern energy-efficient architectural solutions and building construction technologies such as monolithic concrete structures in combination with effective insulation reduce air permeability of building envelope. As a result, air exchange rate is significantly reduced and conditions for increased radon accumulation in indoor air are created. Based on radon survey in Ekaterinburg, Russia, remarkable increase in indoor radon concentration level in energy-efficient multi-storey buildings was found in comparison with similar buildings constructed before the-energy-saving era. To investigate the problem of indoor radon in energyefficient multi-storey buildings, the measurements of radon concentration have been performed in seven modern buildings using radon monitoring method. Values of air exchange rate and other parameters of indoor climate in energy-efficient buildings have been estimated. © The Author 2014. Published by Oxford University Press. All rights reserved.

Zhukovsky M.,Russian Academy of Sciences | Yarmoshenko I.,Russian Academy of Sciences | Kiselev S.,Burnasyan Federal Medical Biophysical Center
Journal of Environmental Radioactivity | Year: 2012

The typical method of radon mapping usually used in most countries is the presenting of average radon concentrations in dwellings for districts or regions. Sometimes the maps of radon concentrations in the soil or maps of percentage above the reference level also demonstrated. Such approach not always can be used for identification of the regions with high probability of radon exposure above the reference levels where the population density is low. The combination of archive geological data and the results of representative radon survey allow estimating the typical parameters of radon concentration distribution for selected categories of buildings (multi-storey or rural type houses) situated in geological zones with the different radon potential. In this case it is possible to give grounds for the necessary level of radon protection measures in the new buildings constructed in this region. The use of such approach in Ural region of Russia is demonstrated. © 2012 Elsevier Ltd.

PubMed | Blokhin Russian Cancer Scientific Center, Burnasyan Federal Medical Biophysical Center and National Research Nuclear University MEPhI
Type: | Journal: Applied radiation and isotopes : including data, instrumentation and methods for use in agriculture, industry and medicine | Year: 2015

In this report the efficacy of extracellular pharmaceutical Gd-DTPA in Binary Radiotherapy was studied. The study was carried out in mice bearing transplantable adenocarcinoma Ca755 using X-ray based contrast enhanced radiotherapy as a practical implementation of Binary Radiotherapy. It was shown that intravenous administration of 0.3 ml of 0.5 M water solution of Gd-DTPA followed by X-irradiation at a dose of 10 Gy provides T/C%=103% and leads to complete tumor regression in 25% of mice.

Larenkov A.A.,Burnasyan Federal Medical Biophysical Center | Bruskin A.B.,Burnasyan Federal Medical Biophysical Center | Kodina G.E.,Burnasyan Federal Medical Biophysical Center
Journal of Radioanalytical and Nuclear Chemistry | Year: 2015

The ion-exchange behavior of 68Ga in mixed HCl–ethanol media on cation and anion exchangers was studied. The mass distribution coefficients of 68Ga on Dowex 50 W × 8 and Dowex 1 × 8 ion-exchange resins at HCl concentrations in the range 0.1–3.0 M and with ethanol volume fractions 0–90 % were determined. The dynamic characteristics of the 68Ga ion exchange in mixed HCl–ethanol solutions were studied. A process, based on the data obtained, was developed for preparing of 68Ga solutions in 0.1 M HCl with high chemical and radiochemical purity that are suitable for producing of 68Ga-radiopharmaceuticals with required quality for clinical use. The suitability of the process for the synthesis of different 68Ga-radiopharmaceuticals in routine clinical practice was demonstrated. © 2015, Akadémiai Kiadó, Budapest, Hungary.

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