scholarly journals Simulated nuclear contamination scenario, solid cancer risk assessment, and support to decision

Nukleonika ◽  
2019 ◽  
Vol 64 (2) ◽  
pp. 41-48 ◽  
Author(s):  
Sergio X. Lima ◽  
Karolina P. S. Costa ◽  
Zelmo R. Lima ◽  
Fagner C. Rother ◽  
Olga M. O. Araujo ◽  
...  
Keyword(s):  
Radiation Effects ◽  
Radioactive Material ◽  
Cancer Risk Assessment ◽  
Whole Body ◽  
Decision Making Process ◽  
Solid Cancer ◽  
Health Physics ◽  
Output Data ◽  
Mathematical Relationships ◽  
Atmospheric Release

Abstract The detonation of an (hypothetical) improvised nuclear device (IND) can generate atmospheric release of radioactive material in the form of particles and dust that ultimately contaminate the soil. In this study, the detonation of an IND in an urban area was simulated, and its effects on humans were determined. The risk of solid cancer development due to radiation was calculated by taking into account prompt radiation and whole-body exposure of individuals near the detonation site up to 10 km. The excess relative risk (ERR) of developing solid cancer was evaluated by using the mathematical relationships from the Radiation Effects Research Foundation (RERF) studies and those from the HotSpot code. The methodology consists of using output data obtained from simulations performed with the HotSpot health physics code plugging in such numbers into a specific given equation used by RERF to evaluate the resulting impact. Such a preliminary procedure is expected to facilitate the decision-making process significantly.

Effect of Two Graded Doses of Whole-Body X-Irradiation and Radioprotection by the Use of S-Phenethyl Formamidino 4 (N-Ethyl Isothioamide) Morpholine Dihydrochloride

1983 ◽  
Vol 22 (05) ◽  
pp. 237-245 ◽  
Author(s):  
P. K. Chaturvedi ◽  
S. N. Pandeya ◽  
S. S. Hasan
Keyword(s):  
Radiation Effects ◽  
Whole Body ◽  
X Irradiation ◽  
Radiation Induced ◽  
Induced Changes ◽  
The Brain

The protection offered by a newly synthesized compound (S-phenethyl-formamidino-4(N-ethyl isothioamide) morpholine dihydrochloride) against radiation effects on DNA, RNA and protein biosynthetic processes in the brain, and on metabolites of 5-HT and nor-adrenalin, i.e., 5-HIAA and VMA, in the urine, including the radiobiological damage to thyroid and testes, was evaluated. The use of the compound prior to irradiation prevented radiation-induced changes in the thyroid and testes. The radiation-induced alterations in the pattern of DNA, RNA, protein in the brain, and in 5-HIAA and VMA in urine could be averted by treatment with this compound prior to each dose of X-irradiation.

scholarly journals Metabolomic Studies of Tissue Injury in Nonhuman Primates Exposed to Gamma-Radiation

2019 ◽  
Vol 20 (13) ◽  
pp. 3360 ◽  
Author(s):  
Amrita K. Cheema ◽  
Khyati Y. Mehta ◽  
Meena U. Rajagopal ◽  
Stephen Y. Wise ◽  
Oluseyi O. Fatanmi ◽  
...  
Keyword(s):  
Ionizing Radiation ◽  
Radiation Effects ◽  
Nonhuman Primates ◽  
Clinical Symptoms ◽  
Tissue Injury ◽  
Predictive Biomarkers ◽  
Whole Body ◽  
Biomarkers Of Exposure ◽  
Radiation Induced ◽  
Over Time

Exposure to ionizing radiation induces a complex cascade of systemic and tissue-specific responses that lead to functional impairment over time in the surviving population. However, due to the lack of predictive biomarkers of tissue injury, current methods for the management of survivors of radiation exposure episodes involve monitoring of individuals over time for the development of adverse clinical symptoms and death. Herein, we report on changes in metabolomic and lipidomic profiles in multiple tissues of nonhuman primates (NHPs) that were exposed to a single dose of 7.2 Gy whole-body 60Co γ-radiation that either survived or succumbed to radiation toxicities over a 60-day period. This study involved the delineation of the radiation effects in the liver, kidney, jejunum, heart, lung, and spleen. We found robust metabolic changes in the kidney and liver and modest changes in other tissue types at the 60-day time point in a cohort of NHPs. Remarkably, we found significant elevation of long-chain acylcarnitines in animals that were exposed to radiation across multiple tissue types underscoring the role of this class of metabolites as a generic indicator of radiation-induced normal tissue injury. These studies underscore the utility of a metabolomics approach for delineating anticipatory biomarkers of exposure to ionizing radiation.

Actions of a novel therapeutic formulation: Zn, Se and Mn plus Lachesis Muta venom (O-LM) on radiation deleterious immune effects

2007 ◽  
Vol 25 (18_suppl) ◽  
pp. 14116-14116
Author(s):  
E. Rivera ◽  
G. Cremaschi ◽  
A. M. Genaro ◽  
M. Croci ◽  
L. Sambuco ◽  
...  
Keyword(s):  
T Lymphocyte ◽  
Radiation Effects ◽  
Protective Action ◽  
Malignant Cell ◽  
Whole Body ◽  
Normal Tissues ◽  
T Lymphocyte Proliferation ◽  
Lymphocyte Activity ◽  
High Doses ◽  
Lachesis Muta

14116 Background: We have previously reported that O-LM inhibits malignant cell proliferation and increases survival in rodent tumor models (Int J Cancer S13:183, 2002). Molecular and immunological basis of O-LM action were reported (J Clin Oncol 24:18S, 2006). As O- LM selectively protects normal tissues from high doses of ionizing radiation (Proc Int Cancer Congress,1495–9, 1998), we here investigated O- LM protective action upon radiation effects on immune cells. Methods: Balb/c mice (n=15 each group) were employed: control (C); 2Gy whole body irradiated (IR); treated with O-LM (Zn, Se, Mn 4μg/ml each; L. Muta 4 ng/ml; 0.1 ml/day, sc) for 15 days and 2Gy irradiated (O-LM+IR). Mice were sacrificed at day 3, 7 or 15 post-irradiation (PI). Proliferation was evaluated in lymphocytes by [3H]- Thymidine incorporation after T- or B selective mitogen stimulation. In cell-free supernatants (SN) from mitogen-stimulated cultures cytokines involved in lymphocyte regulation and/or inflammation were determined by ELISA. Results: Irradiation induced a decrease in T lymphocyte proliferation at 3 and 7 days PI (% of decrease in IR: 47.6±9.0, p<0.05; 42.0±7.2, p<0.02 respectively). Pretreatment with O-LM recovered proliferation to basal values (day 3 PI 93.4±10.2%; day 7 PI 130.9±15.3%, O-LM+IR vs. C; p=NS). No modifications were observed in B cells. At day 3 PI, a marked decrease in IFN? levels was obtained in SN of IR mice that was reverted by O-LM treatment (pg/ml: IR 1653±419; C 10884±2783, p<0.02; O-LM+IR 16924±4284, p<0.05 vs C). Also, at day 7 PI, an important increase in TNFa was observed in IR mice, that were reverted by O-LM (pg/ml: IR: 300.7±62.3 vs O-LM+IR: 28.7±2.3, p<0.02). No differences were found in IL-2 levels. Conclusions: The therapeutic action of O-LM is based on its ability of targeting simultaneously multiple pathways involved in cancer development. Present data demonstrate that O-LM protects animals from irradiation by recovering the immune function, improving T lymphocyte activity and modulating the production of key cytokines as IFN? and TNFa. The reported effect may represent a potential benefit for cancer patients undergoing radiotherapy. No significant financial relationships to disclose.

Operational Values of Radioactive Skin Contamination in the Case of Radiological Accident

2020 ◽  
Vol 65 (3) ◽  
pp. 20-26
Author(s):  
M. Grachev ◽  
Yu. Salenko ◽  
Yu. Abramov ◽  
G. Frolov ◽  
V. Klochkov ◽  
...  
Keyword(s):  
Experimental Studies ◽  
Absorbed Dose ◽  
The Body ◽  
Surface Contamination ◽  
Radioactive Material ◽  
Whole Body ◽  
Laboratory Animals ◽  
Intact Skin ◽  
Radioactive Substances ◽  
Skin Contamination

Purpose: Development of recommendations on the use in medical practice of institutions under FMBA of Russia of operational values of radioactive skin contamination in the event of radiological accidents. Material and methods: The easily measured radiation parameters were used as operational values: ambient dose equivalent rate (ADER) of γ-radiation, density of skin contamination with γ-, β- and α-emitting radionuclides. Operational values ​​of skin contamination were estimated on the basis of experimental data described in the literature and models on the kinetics of radioactive substances transport in the body, accepted values ​​of dose criteria for deterministic and stochastic effects. The estimation of radioactive material resorption through the skin was based on the results of experimental studies in laboratory animals (mainly piglets) for a limited set of chemical compounds of radionuclides. Results: The values of γ-ADER of the main dose-forming radionuclides measured at a distance of 10 cm from the skin surface in the range of 10–1000 μSv/h and the possible health effects due to the skin exposure and the intake of radioactive substances into the body were presented. In the IAEA recommendations, the level of skin contamination at 1 µSv/h is considered as a significant operational value according to the criterion of radioactive substances intake through the mouth from the contaminated surface of the hands. However, in our opinion, this estimate is excessively conservative; therefore it is not included in the recommended operational values. If the skin is contaminated with γ-β-emitting radionuclide solutions at a surface contamination higher than 106 Bq/cm2 (ADER ≥1000 µSv/h), the out of turn emergency decontamination should be carried out. Obligatory indications for the whole body counter examination after thorough decontamination and conducting biophysical analysis of bioassay are the following operational values: γ-ADER from the skin > 10 µSv/h; surface contamination of intact skin with β-active radionuclides > 20 000 β-part./(cm2·min); surface contamination of intact skin with α-active radionuclides > 200 α-part./ (cm2·min). Conclusion: The recommended operational values allow preliminarily and promptly to assess the health risk not only in the case of external (contact) exposure of the skin and underlying tissues, but also due to the intake of soluble radioactive substances into the body through intact and damaged (injured) skin. Taking into account the high degree of uncertainty of the estimates obtained, the operational values ​​should be considered as strictly conservative. They should be used only to determinate of urgency of decontamination carrying out for the provision of medical care during the prehospital and early hospital periods with the obligatory follow-up dosimetry examination for the final assessment of absorbed dose.

scholarly journals The Double Threshold: Consequences for Identifying Low-Dose Radiation Effects

Dose-Response ◽  
2020 ◽  
Vol 18 (3) ◽  
pp. 155932582094972
Author(s):  
Alan Waltar ◽  
Ludwig Feinendegen
Keyword(s):  
Dose Response ◽  
Radiation Effects ◽  
Low Dose ◽  
Development Program ◽  
Absorbed Dose ◽  
Current Data ◽  
Whole Body ◽  
Radiation Quality ◽  
Adaptive Protection ◽  
New Research

Prior to observing low-dose-induced cell signaling and adaptive protection, radiogenic stochastic effects were assumed to be linearly related to absorbed dose. Now, abundant data prove the occurrence of radiogenic adaptive protection specifically at doses below ∼ 200 mGy (with some data suggesting such protection at a dose even higher than 200 mGy). Moreover, cells do not thrive properly when deprived of radiation below background dose. Two threshold doses need be considered in constructing a valid dose-response relationship. With doses beginning to rise from zero, cells increasingly escape radiation deprivation. The dose at which radiation-deprived cells begin to function homeostatically provides dose Threshold A. With further dose increase, adaptive protection becomes prominent and then largely disappears at acute doses above ∼ 200 mGy. The dose at which damage begins to override protection defines Threshold B. Thresholds A and B should be terms in modeling dose-response functions. Regarding whole-body responses, current data suggest for low-LET acute, non-chronic, irradiation a Threshold B of about 100 mGy prevails, except for leukemia and probably some other malignancies, and for chronic, low dose-rate irradiation where the Threshold B may well reach 1 Gy per year. A new Research and Development Program should determine individual Thresholds A and B for various radiogenic cell responses depending on radiation quality and target.

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