WorldWideScience

Sample records for radiation exposed small

  1. Radiation-related small head sizes among prenatally exposed atomic bomb survivors

    International Nuclear Information System (INIS)

    Otaki, Masanori; Schull, William J.

    2004-01-01

    The population prenatally exposed to the atomic bombings of Hiroshima and Nagasaki, referred to as the In Utero Clinical Sample, on whom Dosimetry System 1986 doses are available consists of 1566 individuals (1242 in Hiroshima and 324 in Nagasaki). Of these study subjects, 1473 had the circumference of their heads measured at least once between ages 9 to 19. Among these 1473 individuals, 62 had small heads - the circumference of the head was two standard deviations or more below the observed specific age-at-measurement mean. Twenty-six of the 30 cases with severe mental retardation described elsewhere are included among these subjects. Of these 26 severely mentally retarded cases, 15 (58%) had small heads. Most (86%) of the individuals with small heads were exposed in the first or second trimester of pregnancy - 55% in the former period and 31% in the latter. Various dose-response relationships, with and without a threshold, have been fitted to the data grouped by the trimester or postovulatory age (weeks after ovulation) at which exposure occurred. A significant effect of radiation on the frequency of individuals with atypically small heads is observed only in the first and second trimesters and for the intervals postovulation of 0-7 weeks and 8-15 weeks. Although the risk of a small head at 0-7 weeks postovulation increases significantly with increasing dose, no increase in risk for severe mental retardation is noted in this period. No excess risk of a small head was seen in the third trimester or among individuals exposed at ≥ 16 weeks postovulation. The estimated threshold, based either on a linear or a linear-quadratic dose-response relationship, is zero or thereabouts. This apparent absence of a threshold and the somewhat different periods of vulnerability suggest an embryological difference in the development of both a small head and mental retardation. Mean IQ (using the Koga test) and its standard deviation are 63.8 and 8.5, respectively, for the

  2. Production of sake from rice material exposed to γ-radiation and technical development for its production. Characterization of low-dose exposed rice and small-scale brewing with it

    International Nuclear Information System (INIS)

    Samuta, Takashi; Aramaki, Isao; Hashizume, Katsumi

    1997-01-01

    The effects of γ-ray radiation have been studied on rice materials for sake production. Previous studies showed that the radiation caused to decrease the viscosity as well as the gelatinization heat of those rice and also decrease the chain length of amylose in its endosperm starch. Therefore, it is possible that a new kind sake with excellent quality might be produced by exposing raw material to radiation at an appropriate dose. Here, it was demonstrated that even a low-dose radiation with γ-ray may change various properties of rice including milling characteristics, water absorbing capacity, digestibility, viscosity etc. However, the characteristics as to fermentation were not affected so much and significant changes were observed only in the degree of coloring of the products. The effects of radiation on the constituents of sake were found to be comparatively small. For the production of matured sake, γ-ray radiation was evaluated to be much effective, because the period of maturation was significantly shortened by using irradiated rice material. Thus, a fragrant matured-like sake could be easily produced from γ-ray radiated rice. There remains a trouble in the coloring of the product. (M.N.)

  3. Expression of matrix metalloproteinase-2 and tissue inhibitor of metalloproteinase-2 in radiation exposed small intestinal mucosa of the rat

    International Nuclear Information System (INIS)

    Kwag, Hyon Joo; Lee, Kyoung Ja; Rhee, Chung Sik

    2003-01-01

    The matrix metalloproteinases (MMPs) are a family of enzymes whose main function is the degradation of the extracellular matrix. Several studies have revealed that MMPs and TIMPs are related to the wound healing process and in photoaging caused by ultraviolet irradiation. However, the expressions of MMP and TIMP after irradiation have not, to the best of our knowledge, been studied. This study investigates the expressions of MMP-2 and TIMP-2 in rat intestinal mucosa following irradiation. The entire abdomen of Sprague-Dawley rats was irradiated using a single dose method. The rats were sacrificed on day 1, 2, 3, 5, 7 and 14 following irradiation. Histopathological observations were made using hematoxilin and eosin staining. The expressions of MMP-2 and TIMP-2 were examined using immunohistochemistry, immunoblotting and ELISA. Radiation induced damage, associated with atrophic villi, and infiltration of inflammatory cells was observed from the first postirradiation day, and severe tissue damage was observed on the second and the third postirradiation days. An increase in mitosis and the number of regenerating crypts, as evidence of regeneration, were most noticeable on the fifth postirradiation day. From the immunohistochemistry, the MMP-2 expression was observed from the first postirradiation day, but was most conspicuous on the third and the fifth postirradiation days. The TIMP-2 expression was most conspicuous on the fifth postirradiation day. From the immunoblotting, the MMP-2 expression was strongly positive on the third postirradiation day, and that of TIMP-2 showed a strong positive response on the fifth postirradiation day. In ELISA, tests, the expressions of MMP-2 and TIMP-2. were increased in the postirradiation groups compared to those of the normal controls, and showed a maximum increase on the fifth postirradiation day. These results were statistically significant. The expressions of MMP-2 and TIMP-2 were increased in the intestinal mucosa of the rats

  4. Occupational health care of radiation exposed workers

    International Nuclear Information System (INIS)

    Abdul Rahim Rahman Hamzah

    1995-01-01

    The medical problems encountered by the earlier pioneer workers in radiation at the turn of the century are well known. In the 1928, the ICRP (International Committee for Radiological Protection) was instituted and the ALARA principle of radiation protection was evolved. Occupational health care is about maintaining the health and safety of workers in their workplaces. This involves using medical, nursing and engineering practices to achieve its objectives. In certain occupations, including those where workers are exposed to ionising radiation, some of these principles are enshrined in the legislation and would require statutory compliance. Occupational health care of radiation workers seek to prevent ill health arising from exposure to radiation by consolidating the benefits of exposures control and dosimetry. This is via health surveillance for spillages, contamination and exposures to unsealed sources of radiation. It is unlikely that can plan and hope to cater for a Chernobyl type of disaster. However, for the multitude of workers in industry exposed to radiation, control models are available. These are from the more in industrialize countries with a nuclear based energy industry, and where radioactive gadgetry are used in places ranging from factories and farms to construction sites. These models involve statutory requirements on the standard of work practices, assessment of fitness to work and the monitoring of both the worker and the workplace. A similar framework of activity is present in Malaysia. This will be further enhanced with the development of her general health and safety at work legislation. (author)

  5. Towards harmonized qualifications for radiation exposed personnel

    International Nuclear Information System (INIS)

    Briso, Hugo A.

    2008-01-01

    The accelerated process of globalization affecting mankind doesn't exclude safety matters. Indeed, some trans national corporations are increasingly offering specialized engineering services such as industrial radiography or well lodging. As well, a growing scientific exchange involves the mobility of nuclear researchers in different areas, for instance radiochemistry, nuclear medicine and radiotherapy. Such a breakdown in the technological frontiers must necessarily be reflected by the regulatory solutions. Particularly, diverse levels of theoretical-practical training for radiation exposed personnel coexist in the Latin-American Region, being an especially sensitive problem for radiation protection matters. The spectrum goes from post-graduate courses required for radiation protection officers in some countries, while in others only basic recommendations are required for the operating personnel. Another scheme consists of medium level course for the operating personnel, while radiation protection officers don't have special requirements. Many educational private institutions teach non standardized courses which only give broad concepts of radiation protection. On the other hand, usually nothing is said about the operational training, or else its certification is entrusted to the employer itself. In some countries multiple Regulatory Authorities apply dissimilar criteria to assess safety matters, including the evaluation of workers applications. The necessary regional integration makes indispensable to establish common standards for granting authorizations. Having similar or homogeneous requirements for the universe of radiation exposed personnel, i.e. source operators, radiation protection officers, qualified experts and technical support people would be easier for the Regulatory Authorities to have common methodologies of evaluation for the applicants. An IAEA supported technical cooperation project related to this paper seeks to establish standardized

  6. Effects of Ionizing Radiation in Atopic Patients Exposed to Radiation

    International Nuclear Information System (INIS)

    Radwan, N.K.A.

    2014-01-01

    Atopic dermatitis is a chronic relapsing inflammatory skin disease that arises most commonly during early infancy, and is characterized by severe pruritus, age-dependant skin manifestations, and a fluctuating clinical course. Hereditary, environmental and immunological factors are involved in the aetiopathogenesis of AD. Also the differentiation of helper T- cells, local cytokine profile, IgE, infectious agents and superantigens are factors identified as being involved in the pathogenesis of AD. One hundred patients with AD were selected from the outpatient clinic of the National Center for Radiation Research and Technology in Cairo, Egypt. They were divided into 2 groups; group 1 included radiation workers in the Hall of gamma irradiation unit and group 2 included workers outside controlled area and not exposed to radiation with comparable age and sex. The severity of the disease was evaluated according to the grade of atopic dermatitis. Total and specific serum IgE was measured and Complete Blood Count was also carried out. Four Malassezia species were isolated from AD patients M. globosa, M. furfur, M. sympodialis and M. obtusa. The clinical isolates consisted of two bacterial strains, S. aureus and S. epidermidis. The significant increase of AD severity seems to be more closely related to the prevalence of S. aureus and Malassezia on the skin of radiation workers. This was proved by the presence of high IgE and eosinophils in radiation workers. So, the interactions of low gamma radiation and skin seems to further complicate the risk of assessments of atopic dermatitis

  7. Severe small bowel radiation enteritis

    International Nuclear Information System (INIS)

    Jaen, J.; Santos, J.A.; Carrion, J.R.; Garcia, P.

    1989-01-01

    We have during recent years observed 8 patients with serious radiation injury to the small intestine. As the cases are quite illustrative, their symptomatology is briefly reported and the treatment and possible predisposing factors are analysed. (orig./MG)

  8. Effects of small radiation doses

    International Nuclear Information System (INIS)

    Fuchs, G.

    1986-01-01

    The term 'small radiation dosis' means doses of about (1 rem), fractions of one rem as well as doses of a few rem. Doses like these are encountered in various practical fields, e.g. in X-ray diagnosis, in the environment and in radiation protection rules. The knowledge about small doses is derived from the same two forces, on which the radiobiology of human beings nearly is based: interpretation of the Hiroshima and Nagasaki data, as well as the experience from radiotherapy. Careful interpretation of Hiroshima dates do not provide any evidence that small doses can induce cancer, fetal malformations or genetic damage. Yet in radiotherapy of various diseases, e.g. inflammations, doses of about 1 Gy (100 rad) do no harm to the patients. According to a widespread hypothesis even very small doses may induce some types of radiation damage ('no threshold'). Nevertheless an alternative view is justified. At present no decision can be made between these two alternatives, but the usefullness of radiology is definitely better established than any damage calculated by theories or extrapolations. Based on experience any exaggerated fear of radiations can be met. (author)

  9. Administrative norms on radiofrequency radiation for occupationally exposed persons

    International Nuclear Information System (INIS)

    Saxeboel, G.

    1982-01-01

    The report presents a proposal for administrative norms on radiofrequency (RF) radiation for occupationally exposed persons. The norms establish maximum allowable field exposure in a frequency range from 1 MHz too 300 GHz. (RF)

  10. Epidemiological studies of some populations exposed to ionizing radiation

    International Nuclear Information System (INIS)

    Weeks, J.L.

    1985-08-01

    During 1984 September 19 and 20, a meeting was held at the Whiteshell Nuclear Research Establishment, Pinawa, Manitoba to discuss current epidemiological studies of populations exposed to low levels of ionizing radiation. Twelve representatives from three countries attended the meeting and eleven papers were extensively discussed. The majority of these papers described studies of populations occupationally exposed to radiation. The report contains summaries of the papers presented and of the discussions that took place

  11. Cytogenetics observation and radiation influence evaluation of exposed persons in a discontinuous radiation exposure event

    International Nuclear Information System (INIS)

    Chen Ying; Liu Xiulin; Yang Guoshan; Ge Shili; Jin Cuizhen; Yao Bo

    2003-01-01

    The cytogenetics results and dose estimation of exposed and related persons in an discontinuous radiation exposure event were reported in this paper. According to dicentrics + ring and micronucleus results combined with clinical data, slight (middle) degree of subacute radiation symptom of the victim was diagnosed. A part of 52 examined persons were exposed to radiation in a certain degree

  12. Transistor Small Signal Analysis under Radiation Effects

    International Nuclear Information System (INIS)

    Sharshar, K.A.A.

    2004-01-01

    A Small signal transistor parameters dedicate the operation of bipolar transistor before and after exposed to gamma radiation (1 Mrad up to 5 Mrads) and electron beam(1 MeV, 25 mA) with the same doses as a radiation sources, the electrical parameters of the device are changed. The circuit Model has been discussed.Parameters, such as internal emitter resistance (re), internal base resistance, internal collector resistance (re), emitter base photocurrent (Ippe) and base collector photocurrent (Ippe). These parameters affect on the operation of the device in its applications, which work as an effective element, such as current gain (hFE≡β)degradation it's and effective parameter in the device operation. Also the leakage currents (IcBO) and (IEBO) are most important parameters, Which increased with radiation doses. Theoretical representation of the change in the equivalent circuit for NPN and PNP bipolar transistor were discussed, the input and output parameters of the two types were discussed due to the change in small signal input resistance of the two types. The emitter resistance(re) were changed by the effect of gamma and electron beam irradiation, which makes a change in the role of matching impedances between transistor stages. Also the transistor stability factors S(Ico), S(VBE) and S(β are detected to indicate the transistor operations after exposed to radiation fields. In low doses the gain stability is modified due to recombination of induced charge generated during device fabrication. Also the load resistance values are connected to compensate the effect

  13. Thermoluminescent behavior of diamond thin films exposed to ultraviolet radiation

    International Nuclear Information System (INIS)

    Barboza F, M.; Gastelum, S.; Melendrez, R.; Chernov, V.; Bernal, R.; Cruz V, C.; Brown, F.

    2002-01-01

    In this work the thermoluminescent properties of diamond thin films are discussed which are grown up through the chemical vapor method exposed to ultraviolet radiation of 200-280 nm. The films with thickness 3, 6, 9, 12, 180 and 500 microns were grown up using a precursor gas formed of H 2 -CH 4 -CO excited through microwave energy or hot filament.The structure and morphology of the films were examined through scanning electron microscopy, indicating the formation of different diamond polycrystal structures which depend on the type of heating of the precursor gas used as well as the film dimensions. In general, the brilliance curve depends on the sample and the wavelength of the irradiation ultraviolet light, however it presents clearly thermoluminescence bands in 148, 160, 272, 304, 320 and 324 C degrees. The maximum of the thermoluminescence efficiency is obtained for the case of sample exposure with light of 214 nm. The sample of 500 microns is what exhibits greater thermoluminescent efficiency of those studied samples. The thermoluminescent behavior in function of radiation dose presents regions of linearity and supra linearity for higher and small doses respectively. The disappearance of the thermoluminescent signal depends on the characteristics of the film and it can reach until a 30 % of loss before to reach the stability. (Author)

  14. Evaluation of radiation protection educational level of professional exposed workers

    International Nuclear Information System (INIS)

    Marinkovic, O.; Krstev, S.; Jovanovic, S.

    2006-01-01

    Full text: Serbia and Montenegro legislation concerning with radiation protection was upgrading after publication ICRP- 60 and B.S.S., No.115. Present Law on the Protection against Ionizing Radiation is in force from 1996. Among quite new issues in radiation protection regulations there was article relate to obligatory refresher training. Due to adverse political and economic situation through many years radiation protection regulations were not fulfill completely. The aim of this investigation was to get real view to education level of professional exposed workers. In Serbia and Montenegro the most of ionizing radiation sources are in medical use and the most exposed workers are radiographers and radiologists. The test was passed by 200 radiographers and 50 radiologists. Main groups of questions were: Radiation protection and safety; difference between safety and security; legislation: law and regulations; incidents, accidents and operational failures: recording, learning. Usually, knowledge from school pales. New quantities (as ambient and personal dose equivalent) are mostly unknown. It is easier to understand the real difference between safety and security than to understand linguistic differences. Discussing regulations workers are more interesting in syndicate regulations than radiation protection ones. Operational failures and incidents are hidden. Better to say: nobody dare to speak about them. The results imposed conclusion that regulatory body has to pay more attention to upraise safety culture and radiation protection education level of professional exposed workers. (authors)

  15. UDS in lymphocytes of occupationally radiation exposed persons

    International Nuclear Information System (INIS)

    Tuschl, H.; Kovac, R.

    1982-01-01

    To determine a possible effect of low dose radiation on DNA repair processes, peripheral lymphocytes of mine workers exposed to 222 Rn in the thermal gallery of Badgastein (Austria) and employees of the Austrian Research Centre Seibersdorf, exposed to varying doses of gamma radiation, were investigated. The capacity for unscheduled DNA synthesis (UDS) induced by in vitro UV irradiation was measured by autoradiography of isolated lymphocytes of exposed persons and unexposed controls. In all 222 Rn-exposed mine workers a significant increase of UDS above control values could be observed. Gamma irradiation 31 mrad had a significant effect on UDS, indicating a stimulation of DNA repair capability by chronic low dose exposure. (Author)

  16. Genomic damage in children accidentally exposed to ionizing radiation

    DEFF Research Database (Denmark)

    Fucic, A; Brunborg, G; Lasan, R

    2007-01-01

    During the last decade, our knowledge of the mechanisms by which children respond to exposures to physical and chemical agents present in the environment, has significantly increased. Results of recent projects and programmes focused on children's health underline a specific vulnerability of chil...... and efficient preventive measures, by means of a better knowledge of the early and delayed health effects in children resulting from radiation exposure....... of children to environmental genotoxicants. Environmental research on children predominantly investigates the health effects of air pollution while effects from radiation exposure deserve more attention. The main sources of knowledge on genome damage of children exposed to radiation are studies performed...... after the Chernobyl nuclear plant accident in 1986. The present review presents and discusses data collected from papers analyzing genome damage in children environmentally exposed to ionizing radiation. Overall, the evidence from the studies conducted following the Chernobyl accident, nuclear tests...

  17. Own experiences in genetic counselling of radiation exposed persons

    International Nuclear Information System (INIS)

    Laude, G.; Bruening, L.

    1995-01-01

    An outline is given of genetic counselling provided to 46 radiation-exposed persons during the period from 1978 to 1994. The radiation exposure had, in most cases, been due to radiation-therapeutic measures (n=22). To a low extent, counselling was carried out because of fear of genetic consequences of the Chernobyl reactor accident (n=11), preceding radiation exposure from X-ray (n=9) and nuclear diagnosis (n=1) as well as occupation radiation exposure (n=3). During counselling, information was given on the genetic risk to be expected, taking into consideration the risk factor that is valid at present and the malformation doubling dose. After performance of radiation therapy, an avoidance of conception for 2 years has been recommended. After termination of this period, in the case of an urgent wish of having children, pregnancy was not discouraged if no further risk factors existed. (orig.) [de

  18. Micronuclei frequency in albino rats exposed to high natural radiation

    International Nuclear Information System (INIS)

    Aneesh, D.; Godwin Wesley, S.

    2013-01-01

    Genotoxicity and DNA damage endpoints are used to evaluate results in the context of cell survival. Genotoxicity in mammalian cells is monitored mostly by using cytokinesis-block micronucleus (CBMN) assay. The score of micronuclei (MN) in peripheral blood lymphocytes can be used as a biomarker and also as a bio-dosimeter of radiation exposure. In the present study the effect of natural radiation on albino rats has been investigated, to find out if there is any increase in MN frequency in peripheral blood lymphocytes. Animals at the age of 2-3 weeks were exposed to natural radiation, at the dose of 10.38 μGyh -1 for a period of 6 months. A parallel control set was also maintained (0.12 μGy h -1 '). Blood samples were collected from both test (exposed to natural radiation) and control rats. Lymphocyte culture was done following 'microculture techniques' for 72 h. Cytochalasin B, at a concentration of 6.0 μg/ml, was added to the lymphocyte cultures at 44 h to block cytokinesis. The frequency of MN was evaluated by scoring a total of 1000 binucleated (BN) cells from one slide. The frequency of MN among the rats exposed to natural radiation was found to be 1.83±0.05 per 1000 BN cells and in the control it was 1.82±0.07 per 1000 BN cells. No statistically significant difference in the MN frequencies of exposed and control groups (p>0.05) was seen. The lower MN frequency in natural radiation exposed rats could be an indication of adaptive response. (author)

  19. Computed temperature profile in materials exposed to gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Ping, Tso Chin; Choong, Yap Siew; Seon, Chan Kam

    1987-06-01

    Computed temperature profiles are presented for the materials of lead, steel, concrete and water in curved shells, when they are exposed to gamma radiation. The results are based on the usual simplified theory of thermal conduction with an exponential heat source.

  20. Studies of workers exposed to low doses of external radiation

    International Nuclear Information System (INIS)

    Gilbert, E.S.

    1991-04-01

    Currently, several epidemiologic studies of workers who have been exposed occupationally to low levels of radiation are being conducted, and include studies of workers in the United States, Great Britain, and Canada involved in the production of both defense materials and nuclear power. This paper focuses on studies that evaluate the possible adverse effects resulting from external exposure to radiation. The radiation risk estimates that have been used to establish radiation protection standards for workers and others have been obtained mainly from studies of persons exposed at high doses and dose rates. However, questions remain with regard to the extrapolation process that has been necessary for estimating low-level radiation risks. Occupational studies provide a direct assessment of risk based on data on persons exposed at the actual levels of interest. If current risk estimates are correct, these studies have very little chance of detecting risk, but can still be used to provide useful upper limits on risks. The studies are also adequate to detect serious underestimation of risks. 36 refs., 3 figs., 3 tabs

  1. Protection of persons occupationally exposed to radiation and of patients

    International Nuclear Information System (INIS)

    Stieve, F.E.

    1976-01-01

    The experiences of the last ten years have shown that the measures of the First Radiation Protection Ordinance generally proved to be sufficient for the protection of the employed or of the patients. They had to be amended in so far as the exposure to radiation for those occupationally exposed can be reduced. This results in changes to the regulations so that certain groups of persons can also be effectively controlled. The recognition that medical supervision for radiation protection reasons is reasonable only if exposure has occurred should be additionally utilized in the regulations if the Euratom standards make this possible. The protection of patients attains some new rules which can be derived from handling and from therapeutical use. In this case too experience resulted in a more reasonable application of ionizing radiation and radioactive materials than was expected when the First Radiation Protection Ordinance was issued. (orig.) [de

  2. Chromosomal aberrations in subjects exposed to ionizing radiation

    International Nuclear Information System (INIS)

    Jovicic, D.; Milacic, S.; Kovacevic, R.; Tanaskovic, I.

    2006-01-01

    Occupational exposure is particularly delicate because of chronic exposure to low doses of ionizing radiation and its cumulative effect, where it is important to consider the biological response of body to given conditions of exposure. The objective of this study was the observation of the recovery of the DNA damages in subjects working in the radiation area in two different intervals.Group I, consisting of 30 subjects, was exposed to ionizing radiation and unstable chromosomal aberrations were identified. Group II included the same, re-examined subjects (30) 9 months later. It was verified that 5 (16.67%) subjects still had unstable chromosomal aberrations, although they had been excluded from radiation area Controls groups (C) consisted of 64 subjects that were not exposed to mutagenic agents.The comparison of the control group with the two studied groups revealed the reduction of the unstable aberrations (p<0.05). The total effective doses, which increased with the years spent in radiation area, reflected the yield of chromosomal aberrations. The presence of chromosomal aberrations in some subjects, after the exclusion from the ionising radiation exposure, suggests that the time needed for the recovery of the DNA damages is different, which indicates the individual differences in radiosensitivity as well as different of the reparatory cellular response. (author)

  3. Preventive medical programmes to personnel exposed to ionizing radiation

    International Nuclear Information System (INIS)

    Estrada F, E.

    1996-01-01

    The increasing use of ionizing radiation in the medical field as well as in industry and research grants has special importance to the security aspects related to the individual as well as his surroundings, reason for which the implementation of effective Occupational Radiation Protection Programmes constitutes a priority. Presently, in Guatemala, an Occupational Medicine Programme, directed to the Radiosanitary watch over of occupationally exposed personnel does not exist. It is the goal in this project to organize and establish such programme, based on protective and training actions focused toward the employee as the main entity, his specific activities and his work surroundings. Medical watch over together with Radiation Protection will permit the reduction of the occurrence probability of accidents or incidents, as well as the limitation of stochastic effects to the undermost values. The application scope of the present project is, in the first place, directed to the occupationally exposed personnel of the Direcci[n General de Energ[a Nuclear, as regulatory entity of these activities, and afterwards, its application in the different institutions which work with ionizing radiations. All the previously exposed is based on the Nuclear Legislation prevailing in Guatemala as well as the recommendations of international organizations. (author)

  4. Analysis of reproductive function in persons exposed to chronic radiation

    International Nuclear Information System (INIS)

    Kossenko, M.M.; Ostroumova, E.V.; Vyushkova, O.V.

    2000-01-01

    The purpose of the study was to analyze the reproductive function in individuals exposed to radiation in the riverside villages on the Techa in the Southern Urals. The exposure of the population, numbering 28000, occurred in 1950-1956 as a result of discharges into the river of radioactive wastes from the Mayak facility for processing weapon plutonium. The residents were exposed to chronic radiation, both external and internal. The range of exposure doses to gonads was sufficiently wide: 20-1270 mSv. However, the distribution of doses among the exposed individuals was ununiform, and the proportion of people whose dose was below 120 mGy accounted for 74%. The following characteristics of exposed women were analyzed: menstrual function, outcomes of pregnancy, birth rates, health status for newborns. The analysis of the menstrual function in exposed women showed that in persons exposed in childhood, menarche was registered at the age of 14.3 years, on the average (based on literature sources, menarche is attained at the age of 13 for unexposed population). The mean age at menopause was 47.9 years for exposed women (the respective mean value for Russia is 50.8 years). Pregnancy outcomes were analyzed in 9000 exposed women. The rate of medical and criminal abortions was estimated as 79 per 100 labors. The rate of spontaneous abortions for exposed women was slightly higher, 3.11%, than for controls, 2.30%; these difference, however, were statistically insignificant. The total loss of fetus or neonate (unfavorable outcomes of pregnancy: spontaneous abortions, stillbirths, early neonatal death) was estimated to be 4.58% at zero dose. Exposure to gonads at the dose 1 Sv, estimated using the above-indicated method, yielded 3% of additional unfavorable outcomes of pregnancy. It was shown, based on the analysis of birth rates for the Techa Cohort that they had not undergone any essential changes over the first 25 years of exposure compared to the respective coefficients for

  5. Analysis of reproductive function in persons exposed to chronic radiation

    Energy Technology Data Exchange (ETDEWEB)

    Kossenko, M.M.; Ostroumova, E.V.; Vyushkova, O.V. [Urals Research Center for Radiation Medicine, Chelyabinsk (Russian Federation)

    2000-05-01

    The purpose of the study was to analyze the reproductive function in individuals exposed to radiation in the riverside villages on the Techa in the Southern Urals. The exposure of the population, numbering 28000, occurred in 1950-1956 as a result of discharges into the river of radioactive wastes from the Mayak facility for processing weapon plutonium. The residents were exposed to chronic radiation, both external and internal. The range of exposure doses to gonads was sufficiently wide: 20-1270 mSv. However, the distribution of doses among the exposed individuals was ununiform, and the proportion of people whose dose was below 120 mGy accounted for 74%. The following characteristics of exposed women were analyzed: menstrual function, outcomes of pregnancy, birth rates, health status for newborns. The analysis of the menstrual function in exposed women showed that in persons exposed in childhood, menarche was registered at the age of 14.3 years, on the average (based on literature sources, menarche is attained at the age of 13 for unexposed population). The mean age at menopause was 47.9 years for exposed women (the respective mean value for Russia is 50.8 years). Pregnancy outcomes were analyzed in 9000 exposed women. The rate of medical and criminal abortions was estimated as 79 per 100 labors. The rate of spontaneous abortions for exposed women was slightly higher, 3.11%, than for controls, 2.30%; these difference, however, were statistically insignificant. The total loss of fetus or neonate (unfavorable outcomes of pregnancy: spontaneous abortions, stillbirths, early neonatal death) was estimated to be 4.58% at zero dose. Exposure to gonads at the dose 1 Sv, estimated using the above-indicated method, yielded 3% of additional unfavorable outcomes of pregnancy. It was shown, based on the analysis of birth rates for the Techa Cohort that they had not undergone any essential changes over the first 25 years of exposure compared to the respective coefficients for

  6. Rubella virus detection by ELISA method in exposed radiation workers

    International Nuclear Information System (INIS)

    Wu Jianmei; Zhu Bo; Zhu Youming; Shao Jinhui; Wu Weiping; Han Jinxiang

    2005-01-01

    Objective: A rapid diagnosis method was developed to detect Rubella virus infection in radiation workers. Methods: Modified ELISA method was used to detect the level of lgG and lgM antibodies in 514 in Jinan district. Results: 90.47% of 514 cases was shown to be resistant against Rubella virus; 6.42% were sensitive type; 0.78% belonged to be reinfected. Conclusion: Detection of Rubella virus in exposed radiation workers was imperative, and vaccine against Rubella virus was also needed to eliminate the infection risk. (authors)

  7. Cytogenetic investigation of subjects professionally exposed to radiofrequency radiation.

    Science.gov (United States)

    Maes, Annemarie; Van Gorp, Urbain; Verschaeve, Luc

    2006-03-01

    Nowadays, virtually everybody is exposed to radiofrequency radiation (RFR) from mobile phone base station antennas or other sources. At least according to some scientists, this exposure can have detrimental health effects. We investigated cytogenetic effects in peripheral blood lymphocytes from subjects who were professionally exposed to mobile phone electromagnetic fields in an attempt to demonstrate possible RFR-induced genetic effects. These subjects can be considered well suited for this purpose as their RFR exposure is 'normal' though rather high, and definitely higher than that of the 'general population'. The alkaline comet assay, sister chromatid exchange (SCE) and chromosome aberration tests revealed no evidence of RFR-induced genetic effects. Blood cells were also exposed to the well known chemical mutagen mitomycin C in order to investigate possible combined effects of RFR and the chemical. No cooperative action was found between the electromagnetic field exposure and the mutagen using either the comet assay or SCE test.

  8. The management of workers occupationally exposed to ionizing radiation

    International Nuclear Information System (INIS)

    1993-10-01

    In Canada, the regulation of radiation protection is a shared responsibility between the federal body (the Atomic Energy Control Board) and the appropriate provincial body (usually the Department of Health, or Department of Labour). The AECB is responsible, for example, for regulating the development, application and use of nuclear energy and radioisotopes, and the provinces are responsible for the regulation of all other forms of ionizing and non-ionizing radiations and for naturally-occurring radioactive material (NORM). Although there is consultation between the federal and provincial regulatory agencies, the division of jurisdictional authority has resulted in considerable differences in the approach towards implementation radiation protection programs in Canada. This is especially true in the management of workers occupationally exposed to ionizing radiation. These differences have produced unwarranted discrepancies in operating procedures and practices in the allocation of resources and manpower, and in the requirements governing radiological training, personnel monitoring and medical surveillance. In light of the General Amendments to the AEC Regulations, the 1990 Recommendations of the ICRP, and the IAEA recommendations on safety culture, the ACRP has considered it timely to undertake a study to examine the feasibility of establishing a more coherent approach to harmonize radiation protection practices within Canada. This study comprised an examination of the regulatory approach used in several countries: a review of the nature of radiation safety programs in various types of licensed institutions and facilities in Canada; and a review of recommendations of internationally-recognized authorities in radiation protection

  9. Radiation pneumonitis in a patient exposed to asbestos

    International Nuclear Information System (INIS)

    Ashford, R.F.U.; Maher, J.; Drury, A.; Pickering, D.

    1981-01-01

    A case report is presented of a 58 year old man who had for many years run an asbestos importing and fibreizing plant. He developed radiation pneumonitis following radiotherapy to a squamous cell carcinoma of the middle 3rd of the oesophagus. Detailed lung studies at autopsy revealed asbestos bodies associated with macrophages in many alveoli and areas of subpleural fibrosis typical of asbestos exposure. This was the most florid case of radiation seen in the Westminster Hospital for some years and the first seen in patients treated for carcinoma of the oesophagus using a three field technique. It is suggested that when planning radiotherapy to an asbestos-exposed patient, a possible increase in lung sensitivity to radiation should be considered when planning dosage. (U.K.)

  10. Mammalian cells exposed to ionizing radiation: structural and biochemical aspects

    International Nuclear Information System (INIS)

    Sabanero, M.; Flores V, L. L.; Azorin V, J. C.; Vallejo, M. A.; Cordova F, T.; Sosa A, M.; Castruita D, J. P.; Barbosa S, G.

    2015-10-01

    Acute or chronic exposure to ionizing radiation is a factor that may be hazardous to health. It has been reported that exposure to low doses of radiation (less than 50 mSv / year) and subsequently exposure to high doses have greater effects in people. However, it is unknown molecular and biochemical level alteration. This study, analyzes the susceptibility of a biological system (HeLa Atcc CCL-2 human cervix cancer cell line) to ionizing radiation (6 and 60 mSv/ 90). Our evaluate multiple variables such as: total protein profile, mitochondrial metabolic activity (XTT assay), cell viability (Trypan blue exclusion assay), cytoskeleton (actin micro filaments), nuclei (D API), genomic DNA. The results indicate, that cells exposed to ionizing radiation structurally show alterations in nuclear phenotype and aneuploidy, further disruption in the tight junctions and consequently on the distribution of actin micro filaments. Similar alterations were observed in cells treated with a genotoxic agent (200μM H 2 O 2 /1 h). In conclusion, this multi-criteria assessment enables precise comparisons of the effects of radiation between any biological systems. However, it is necessary to determine stress markers for integration of the effects of ionizing radiation. (Author)

  11. Mammalian cells exposed to ionizing radiation: structural and biochemical aspects

    Energy Technology Data Exchange (ETDEWEB)

    Sabanero, M.; Flores V, L. L. [Universidad de Guanajuato, Departamento de Biologia, DCNE, Noria Alta s/n, 36250 Guanajuato, Gto. (Mexico); Azorin V, J. C.; Vallejo, M. A.; Cordova F, T.; Sosa A, M. [Universidad de Guanajuato, Departamento de Ingenieria Fisica, DCI, Loma del Bosque 103, Col. Lomas del Campestre, 37150 Leon, Guanajuato (Mexico); Castruita D, J. P. [Universidad de Guadalajara, Departamento de Ecologia, CUCBA, Las Agujas, 45100 Zapopan, Jalisco (Mexico); Barbosa S, G., E-mail: myrna.sabanero@gmail.com [Universidad de Guanajuato, Departamento de Ciencias Medicas, DCS, 20 de Enero No. 929, Col. Obregon, 37000 Leon, Guanajuato (Mexico)

    2015-10-15

    Acute or chronic exposure to ionizing radiation is a factor that may be hazardous to health. It has been reported that exposure to low doses of radiation (less than 50 mSv / year) and subsequently exposure to high doses have greater effects in people. However, it is unknown molecular and biochemical level alteration. This study, analyzes the susceptibility of a biological system (HeLa Atcc CCL-2 human cervix cancer cell line) to ionizing radiation (6 and 60 mSv/ 90). Our evaluate multiple variables such as: total protein profile, mitochondrial metabolic activity (XTT assay), cell viability (Trypan blue exclusion assay), cytoskeleton (actin micro filaments), nuclei (D API), genomic DNA. The results indicate, that cells exposed to ionizing radiation structurally show alterations in nuclear phenotype and aneuploidy, further disruption in the tight junctions and consequently on the distribution of actin micro filaments. Similar alterations were observed in cells treated with a genotoxic agent (200μM H{sub 2}O{sub 2}/1 h). In conclusion, this multi-criteria assessment enables precise comparisons of the effects of radiation between any biological systems. However, it is necessary to determine stress markers for integration of the effects of ionizing radiation. (Author)

  12. Ionizing radiation and frequency of chromosomal aberrations in exposed personnel

    International Nuclear Information System (INIS)

    Spasojevic-Tisma, Vera; Pavlovic, Snezana

    2008-01-01

    Full text: Frequencies of chromosomal aberrations in lymphocytes of peripheral blood were investigated among the observed groups of subjects who were exposed to low radiation doses (external exposure) in comparison with the control group. The first group of subjects is involved in the production of radioisotope technetium, whose accumulated work exposure time ranges between 3 and 30 years. The second group works on inspection of the medical X-ray equipment, whose accumulated work exposure time is between 2 and 34 years. The third group worked on decontamination of the terrain from depleted uranium radioactive ammunition. These workers were involved in mechanical removal of the surface soil layer to a depth of 50 cm. They were selected out of a group of professionals otherwise exposed to radiation from confined sources in their daily work. The accumulated work exposure of this group ranged from 2 to 34 years. The control group consisted of individuals not working in the ionizing radiation zone. The average yearly absorbed dose measured by TL dosimeters for all three observed groups did not exceed 2 mSv. The chromosomal aberrations were analyzed by a modified Moorhead method. The objective of the study was to establish the existence of differences in the frequencies of chromosomal aberrations change with respect to the source type, i.e. type of radioactive emission. Comparisons of the chromosomal changes in the observed groups revealed that the group working on technetium production had an increase in the frequency of chromosomal aberrations with respect to control. The aberrations found were of the acentric fragment and chromosomal break types. A comparison of the exposed groups between each other, no statistically significant differences in the numbers of chromosomal aberrations were found. Soil decontamination from depleted uranium did not contribute to the relative radiation risk, since it lasted only a few months, and was done by the professionals fully clothed

  13. Thermoluminescent dosemeters (TLD) exposed to high fluxes of gamma radiation, thermal neutrons and protons

    International Nuclear Information System (INIS)

    Gambarini, G.; Martini, M.; Meinardi, F.; Raffaglio, C.; Salvadori, P.; Scacco, A.; Sichirollo, A.E.

    1996-01-01

    Thermoluminescent dosemeters (TLD), widely experimented and utilized in personal dosimetry, have some advantageous characteristics which induce one to employ them also in radiotherapy. The new radiotherapy techniques are aimed at selectively depositing a high dose in cancerous tissues. This goal is reached by utilising both conventional and other more recently proposed radiation, such as thermal neutrons and heavy charged particles. In these inhomogeneous radiation fields a reliable mapping of the spatial distribution of absorbed dose is desirable, and the utilized dosemeters have to give such a possibility without notably perturbing the radiation field with the materials of the dosemeters themselves. TLDs, for their small dimension and their tissue equivalence for most radiation, give good support in the mapping of radiation fields. After exposure to the high fluxes of therapeutic beams, some commercial TL dosemeters have shown a loss of reliability. An investigation has therefore be performed, both on commercial and on laboratory made phosphors, in order to investigate their behaviour in such radiation fields. In particular the thermal neutron and gamma ray mixed field of the thermal column of a nuclear reactor, of interest for Boron Neutron Capture Therapy (B.N.C.T.) and a proton beam, of interest for proton therapy, were considered. Here some results obtained with new TL phosphors exposed in such radiation fields are presented, after a short description of some radiation damage effect on commercial LiF TLDs exposed in the (n th ,γ) field of the thermal column of a reactor. (author)

  14. Radiation research contracts: Biological effects of small radiation doses

    Energy Technology Data Exchange (ETDEWEB)

    Hug, O [International Atomic Energy Agency, Division of Health, Safety and Waste Disposal, Vienna (Austria)

    1959-04-15

    To establish the maximum permissible radiation doses for occupational and other kinds of radiation exposure, it is necessary to know those biological effects which can be produced by very small radiation doses. This particular field of radiation biology has not yet been sufficiently explored. This holds true for possible delayed damage after occupational radiation exposure over a period of many years as well as for acute reactions of the organism to single low level exposures. We know that irradiation of less than 25 Roentgen units (r) is unlikely to produce symptoms of radiation sickness. We have, however, found indications that even smaller doses may produce certain instantaneous reactions which must not be neglected

  15. Studies on chromosome aberrations in workers occupationally exposed to radiation

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jong Hyung; Oh, Hyeon Joo; Shim, Sun Bo; Roh, Hye Won; Lee, Hai Yong [Korea Food and Drug Administration, Seoul (Korea, Republic of); Kang, Soon Ja [Ewha Womens Univ., Seoul (Korea, Republic of)

    1998-06-01

    Cytogenetic assays for unstable chromosomes were performed on 54 medical radiation workers who are occupationally exposed to radiation and 42 controls. A total of 15,577 metaphase cells were scored. The frequencies of dicentrics and acentric chromosomes on controls were 0.52*10{sup -3} and 0.82*10{sup -2}, respectively. On radiation workers those were 2.28*10{sup -3} and 1.34*10{sup -2}, respectively. Though the frequencies of all types of chromosome aberrations in the workers were higher than those in the controls, the only significant difference was found in the case of dicentrics (P < 0.01). When we considered exposure dose of recent one year, duration of employment and smoking habit in radiation worker, a slight increase was shown in frequency of unstable chromosome aberrations on these workers, but no statistical differences were observed (P > 0.05) except exposure dose of recent one year (P < 0.05). These results could indicate that low level exposure to ionizing radiation can induce unstable chromosome aberrations in blood lymphocytes.

  16. Assessment of the hormonal state of medical personnel occupationally exposed to ionizing radiation

    International Nuclear Information System (INIS)

    Bliznakov, V.; Maleeva, A.; Mikhaylov, M.

    1982-01-01

    Testosterone, follicle-stimulating hormone (FSH) and luteinizing hormone (LH) concentrations are assayed in 14 men against the background of occupational exposure of medical personnel to small - dose radiations. Low testosterone values, and elevated LH and FSH levels are established. A preliminary conclusion is made according to which in occupationally exposed men in the field of medicine there is a disturbance of hormonal secretion along the hypophysis - target gland axis. Twenty normal men of comparable age are studied for control purpose. (author)

  17. Medical examination of the workers occupationally exposed to ionizing radiation

    International Nuclear Information System (INIS)

    Kato, Toshio

    1991-01-01

    The hazardous effects of ionizing radiation to man are well recognized, and they are divided into two groups, the stochastic effects (hereditary and carcinogenic effect) and non-stochastic effects (somatic effects such as depression of hematopoiesis, chronic dermatitis and cataracta). The basic framework of the International Commission on Radiological Protection (ICRP) is intended to prevent the occurrence of non-stochastic effects, by keeping doses below the relevant thresholds, and to ensure that all reasonable aspects are taken to reduce the incidence of stochastic effects. In Japan, the regulatory provisions of radiological protection of the workers occupationally exposed to ionizing radiation are based on the recommendation of ICRP adopted in 1977. According to these regulations, the dose equivalent limits of occupational exposure of man has been decided at 50 mSv/year. The monitoring of exposure to the individual and the procedure of medical examination of the workers are briefly described and discussed. (author)

  18. Conditions for licensing workers exposed to ionizing radiation

    International Nuclear Information System (INIS)

    2007-01-01

    This entrance speaking on conditions of license workers in the areas of employment ionizing radiation addresses two aspects, the first aspect: industrial applications: speak for the workers in this area by a supervisor to portray industrial and industrial photographer and a supervisor sounding wells and a Nuclear Gauges Supervisor and the previous and subsequent Practices of the law The second aspect: about the medical applications and describes the general conditions of the licenses in this area and those working in this area of professional diagnostic radiology and nuclear medicine technician and technician treatment of radiotherapy and radiation protection officers at large and small institutions

  19. Counseling Patients Exposed to Ionizing Radiation in Diagnostic Radiology During Pregnancy

    International Nuclear Information System (INIS)

    Brnic, Z.; Leder, N.I.; Popic Ramac, J.; Vidjak, V.; Knezevic, Z.

    2013-01-01

    There are many false assumptions regarding influence of radiation on pregnant patients and fetus during diagnostic procedures in spite of scientific facts based on studies (both in general population and among physicians). These false assumptions are mostly based on the idea that every diagnostic procedure that uses ionizing radiation is a cause for serious concern and consideration for artificial abortion as a possible solution. We have analysed the data of counselling of pregnant patients exposed to ionizing radiation during diagnostic procedures in University Hospital Merkur, during a period of four years. In this period we had 26 patients come in counselling due to exposure to ionizing radiation during pregnancy. Results show that most of these patients have been exposed to radiation between 2nd and 3rd week of gestation (36 %), between 4th and 5th week - 32 %; before 2nd week - 24%; and after 6th week of gestation less than 8 %. Average doses were: up to 0.01 cGy in 46.2 % patients; 0.01 - 0.15 cGy in 19.2 % patients; 0.2 - 1 cGy in 26.9 % and 1 cGy or more in 7.7 % of patients. No one of the counselled patients had a medical indication for abortion, even though in a small percentage of patients abortion was a personal subjective decision. Considering that there are no Croatian guidelines for counselling patients exposed to ionizing radiation during pregnancy, recommendation is to use International Commission on Radiological Protection (ICRP) guidelines for management of pregnant patients exposed to ionizing radiation.(author)

  20. Frequency of chromosomal aberrations in workers occupationally exposed to ionizing radiations

    International Nuclear Information System (INIS)

    Spasojevic-Tisma, V.; Joksic, G.; Ilic, Z.; Milanovic, S.; Djuric, J.; Tisma, J.; Celeketic, D.; Cuknic, O.; Perisic, J.; Milacic, S.; Cuknic, O.)

    2007-01-01

    Subjects occupationally exposed to ionizing radiation (external exposition) are examined for chromosomal aberrations in peripheral blood lymphocytes in comparison to a control group. The average annual absorbed dose, measured by TLD dosimeters, for all three groups did not exceed 2mSv. Continuous exposure to small doses of ionizing radiation causes unstable aberrations in lymphocytes. In this research the largest number of found alterations are of acentric fragments and chromosomal breaks type. The highest occupational risk appears to be for subjects working in manufacturing of radio isotope technetium [sr

  1. Advanced Small Animal Conformal Radiation Therapy Device.

    Science.gov (United States)

    Sharma, Sunil; Narayanasamy, Ganesh; Przybyla, Beata; Webber, Jessica; Boerma, Marjan; Clarkson, Richard; Moros, Eduardo G; Corry, Peter M; Griffin, Robert J

    2017-02-01

    We have developed a small animal conformal radiation therapy device that provides a degree of geometrical/anatomical targeting comparable to what is achievable in a commercial animal irradiator. small animal conformal radiation therapy device is capable of producing precise and accurate conformal delivery of radiation to target as well as for imaging small animals. The small animal conformal radiation therapy device uses an X-ray tube, a robotic animal position system, and a digital imager. The system is in a steel enclosure with adequate lead shielding following National Council on Radiation Protection and Measurements 49 guidelines and verified with Geiger-Mueller survey meter. The X-ray source is calibrated following AAPM TG-61 specifications and mounted at 101.6 cm from the floor, which is a primary barrier. The X-ray tube is mounted on a custom-made "gantry" and has a special collimating assembly system that allows field size between 0.5 mm and 20 cm at isocenter. Three-dimensional imaging can be performed to aid target localization using the same X-ray source at custom settings and an in-house reconstruction software. The small animal conformal radiation therapy device thus provides an excellent integrated system to promote translational research in radiation oncology in an academic laboratory. The purpose of this article is to review shielding and dosimetric measurement and highlight a few successful studies that have been performed to date with our system. In addition, an example of new data from an in vivo rat model of breast cancer is presented in which spatially fractionated radiation alone and in combination with thermal ablation was applied and the therapeutic benefit examined.

  2. Cytogenetic dose-response and adaptive response in cells of ungulate species exposed to ionizing radiation

    International Nuclear Information System (INIS)

    Ulsh, B.A.; Miller, S.M.; Mallory, F.F.; Mitchel, R.E.J.; Morrison, D.P.; Boreham, D.R.

    2004-01-01

    In the studies reported here, the micronucleus assay, a common cytogenetic technique, was used to examine the dose-responses in fibroblasts from three ungulate species (white-tailed deer, woodland caribou, and Indian muntjac) exposed to high doses of ionizing radiation (1-4 Gy of 60 Co gamma radiation). This assay was also used to examine the effects of exposure to low doses (1-100 mGy) typical of what these species experience in a year from natural and anthropogenic environmental sources. An adaptive response, defined as the induction of resistance to a stressor by a prior exposure to a small 'adapting' stress, was observed after exposure to low doses. This work indicates that very small doses are protective for the endpoint examined. The same level of protection was seen at all adapting doses, including 1 radiation track per cell, the lowest possible cellular dose. These results are consistent with other studies in a wide variety of organisms that demonstrate a protective effect of low doses at both cellular and whole-organism levels. This implies that environmental regulations predicated on the idea that even the smallest dose of radiation carries a quantifiable risk of direct adverse consequences to the exposed organism require further examination. Cytogenetic assays provide affordable and feasible biological effects-based alternatives that are more biologically relevant than traditional contaminant concentration-based radioecological risk assessment

  3. Action spectra in mammalian cells exposed to ultraviolet radiation

    International Nuclear Information System (INIS)

    Anon.

    1981-01-01

    A review is given of the literature published since 1977 on action spectra in mammalian cells exposed to ultraviolet radiation in the wavelength region above 220 nm. Action spectra for lethal events are discussed for cell inactivation in normal cells, growth arrested cells and photosensitive cells. Action spectra for non-lethal events are also discussed in relation to pyrimidine dimer formation, photoreactivation and the use of photosensitisers. It was concluded from these studies that damage to the DNA, and the extent of the repair of this damage, seems to determine a cell's response to such parameters as inactivation, mutation, transformation, latent viral activation, cellular viral capacity and ultraviolet enhanced viral reactivation. In addition to the direct effects of UV on DNA, photosensitization of cellular responses with chemicals such as 8-MOP extend the wavelength range at which damage can be demonstrated. (U.K.)

  4. Viability and Virulence of Entomopathogenic Nematodes Exposed to Ultraviolet Radiation.

    Science.gov (United States)

    Shapiro-Ilan, David I; Hazir, Selcuk; Lete, Luis

    2015-09-01

    Entomopathogenic nematodes (EPNs) can be highly effective biocontrol agents, but their efficacy can be reduced due to exposure to environmental stress such as from ultraviolet (UV) radiation. Our objectives were to 1) compare UV tolerance among a broad array of EPN species, and 2) investigate the relationship between reduced nematode viability (after exposure to UV) and virulence. Nematodes exposed to a UV radiation (254 nm) for 10 or 20 min were assessed separately for viability (survival) and virulence to Galleria mellonella. We compared 9 different EPN species and 15 strains: Heterorhabditis bacteriophora (Baine, fl11, Oswego, and Vs strains), H. floridensis (332), H. georgiana (Kesha), H. indica (HOM1), H. megidis (UK211), Steinernema carpocapsae (All, Cxrd, DD136, and Sal strains), S. feltiae (SN), S. rarum (17C&E), and S. riobrave (355). In viability assessments, steinernematids, particularly strains of S. carpocapsae, generally exhibited superior UV tolerance compared with the heterorhabditids. However, some heterorhabditids tended to be more tolerant than others, e.g., H. megidis and H. bacteriophora (Baine) were most susceptible and H. bacteriophora (Vs) was the only heterorhabditid that did not exhibit a significant effect after 10 min of exposure. All heterorhabditids experienced reduced viability after 20 min exposure though several S. carpocapsae strains did not. In total, after 10 or 20 min exposure, the viability of seven nematode strains did not differ from their non-UV exposed controls. In virulence assays, steinernematids (particularly S. carpocapsae strains) also tended to exhibit higher UV tolerance. However, in contrast to the viability measurements, all nematodes experienced a reduction in virulence relative to their controls. Correlation analysis revealed that viability among nematode strains is not necessarily related to virulence. In conclusion, our results indicate that the impact of UV varies substantially among EPNs, and viability alone

  5. Implications of radiation dose and exposed populations on radiation protection in the 21st century.

    Science.gov (United States)

    Boice, John D

    2014-02-01

    Radiation is in the public eye because of Fukushima, computed tomography examinations, airport screenings, and possible terrorist attacks. What if the Boston Marathon pressure cooker had also contained a radioactive source? Nuclear power may be on the resurgence. Because of the increasing uses of radiation, the increases in population exposures, and the increasing knowledge of radiation effects, constant vigilance is needed to keep up with the changing times. Psychosocial disorders associated with the inappropriate (but real) fear of radiation need to be recognized as radiation detriments. Radiation risk communication, radiation education, and communication must improve at all levels: to members of the public, to the media, to other scientists, and to radiation professionals. Stakeholders must continue to be involved in all radiation protection initiatives. Finally, we are at a crisis as the number of war babies (me) and baby boomers (you?) who are also radiation professionals continues its rapid decline, and there are few in the pipeline to fill the current and looming substantial need: "The old road is rapidly agin'" (Dylan). NCRP has begun the WARP initiative-Where Are the Radiation Professionals?-an attempt to rejuvenate the pipeline of future professionals before the trickle becomes tiny drops. A Workshop was held in July 2013 with government agencies, military, private sector, universities, White House representatives, and societies to develop a coordinated and national action plan. A "Manhattan Project" is needed to get us "Back to the Future" in terms of the funding levels that existed in years past that provided the necessary resources to train, engage, and retain (a.k.a., jobs) the radiation professionals needed for the nation. If we don't keep swimmin' (Disney's Nemo) we'll "sink like a stone" (Dylan).Introduction of Implications of Radiation Dose and Exposed Populations (Video 2:06, http://links.lww.com/HP/A25).

  6. Optical radiative properties of ablating polymers exposed to high-power arc plasmas

    Science.gov (United States)

    Becerra, Marley; Pettersson, Jonas

    2018-03-01

    The radiative properties of polymers exposed to high-intensity radiation are of importance for the numerical simulation of arc-induced ablation. The paper investigates the optical properties of polymethylmethacrylate PMMA and polyamide PA6 films exposed to high-power arc plasmas, which can cause ablation of the material. A four-flux radiative approximation is first used to estimate absorption and scattering coefficients of the tested materials in the ultraviolet (UV) and in the visible (VIS) ranges from spectrophotometric measurements. The temperature-induced variation of the collimated transmissivity of the polymers is also measured from room temperature to the glass temperature of PMMA and the melting temperature of PA6. Furthermore, band-averaged absorption and scattering coefficients of non-ablating and ablating polymers are estimated from the UV to the short-wavelength infrared (SWIR), covering the range of interest for the simulation of arc-induced ablation. These estimates are obtained from collimated transmissivities measured with an additional in situ photometric system that uses a high-power, transient arc plasma to both illuminate the samples and to induce ablation. It is shown that the increase in the bulk temperature of PA6 leads to a strong reversible increase in collimated transmissivity, significantly reducing the absorption and scattering coefficients of the material. A weaker but opposite effect of temperature on the optical properties is found in PMMA. As a consequence, it is suggested that the absorption coefficient of polymers used for arc-induced ablation estimates should not be taken directly from direct collimated transmissivity measurements at room temperature. The band-averaged radiation measurements also show that the layer of products released by ablation of PMMA produces scattering radiation losses mainly in the VIS-SWIR ranges, which are only a small fraction of the total incident arc radiation. In a similar manner, the ablation layer

  7. Cytogenetic monitoring of nuclear workers occupationally exposed to ionising radiation

    International Nuclear Information System (INIS)

    Griciene, B.; Slapsyte, G.; Mierauskiene, J.

    2014-01-01

    Chromosome aberration (CA) analysis using Giemsa techniques was performed in blood lymphocytes of 84 nuclear workers with cumulative doses of 1-632 mSv during employment periods of 1-25 y. The control group comprised 82 healthy male donors. An estimated CA frequency in the total radiation-exposed group was significantly higher when compared with the controls (2.27 vs. 1.76 CA/100 cells, p 0.05). However, significant increase in the total CA frequency was determined in workers with additional internal exposure (2.54 CA/100 cells, p < 0.05) and those with registered neutron doses (2.95 CA/100 cells, p < 0.01). No correlation was found between CA frequency and occupational exposure dose. Borderline significant correlation was found between duration of employment and total CA (r = 0.218, p = 0.046, Fig. 2) and chromosome-type aberration (r = 0.265, p = 0.015) frequency. (authors)

  8. Radiation dose assessment for occupationally exposed workers in ...

    African Journals Online (AJOL)

    2017-01-31

    Jan 31, 2017 ... with the legislation and safety requirements, has not yet been established. ... occupational exposure to ionising radiation such as X-rays. This study was hence ..... ionizing radiation), conventional X-ray machines or mobile.

  9. Studies on the hazard of leukaemia and cancer in persons occupationally exposed to radiation

    International Nuclear Information System (INIS)

    Streffer, C.

    1988-01-01

    The mortality rates of British radiologists in dependence of the duration of their radiation work are compared with the general mortality rate in England and Wales, the mortality rates of men of the social class 1 and the mortality rates of practicing physicians. It turns out that the mortality by malignant diseases (leukemia and cancer) of persons exposed to radiation at work in nuclear plants is not considerably higher than it is for comparable groups of persons not exposed to radiation. Tumour entities of the GI tract have not been found either in the British radiologists exposed to radiation. (DG) [de

  10. Autonomous Radiation Monitoring of Small Vessels

    International Nuclear Information System (INIS)

    Fabris, Lorenzo; Hornback, Donald Eric

    2010-01-01

    Small private vessels are one avenue by which nuclear materials may be smuggled across international borders. While one can contemplate using the terrestrial approach of radiation portal monitors on the navigable waterways that lead to many ports, these systems are ill-suited to the problem. They require vehicles to pass at slow speeds between two closely-spaced radiation sensors, relying on the uniformity of vehicle sizes to space the detectors, and on proximity to link an individual vehicle to its radiation signature. In contrast to roadways where lanes segregate vehicles, and motion is well controlled by inspection booths; channels, inlets, and rivers present chaotic traffic patterns populated by vessels of all sizes. We have developed a unique solution to this problem based on our portal-less portal monitor instrument that is designed to handle free-flowing traffic on roadways with up to five-traffic lanes. The instrument uses a combination of visible-light and gamma-ray imaging to acquire and link radiation images to individual vehicles. It was recently tested in a maritime setting. In this paper we present the instrument, how it functions, and the results of the recent tests.

  11. Autonomous radiation monitoring of small vessels

    International Nuclear Information System (INIS)

    Ziock, K.P.; Cheriyadat, A.; Fabris, L.; Goddard, J.; Hornback, D.; Karnowski, T.; Kerekes, R.; Newby, J.

    2011-01-01

    Small private vessels are one avenue by which nuclear materials may be smuggled across international borders. While one can contemplate using the land-based approach of radiation portal monitors on the navigable waterways that lead to many ports, these systems are ill-suited to the problem. In contrast to roadways, where lanes segregate vehicles, and motion is well controlled by inspection booths; channels, inlets, and rivers present chaotic traffic patterns populated by vessels of all sizes. A unique solution to this problem is based on a portal-less portal monitor designed to handle free-flowing traffic on roadways with up to five-traffic lanes. The instrument uses a combination of visible-light and gamma-ray imaging to acquire and link radiation images to individual vehicles. This paper presents the results of a recent test of the system in a maritime setting.

  12. The modes of death in mammals exposed to whole body radiation (acute radiation syndromes)

    International Nuclear Information System (INIS)

    Santos, O.R. dos.

    1990-07-01

    When an animal is exposed to a sufficient amount of radiation, there will be changes in many organs of the body, and as a result of either the effects in one particular organ or the interaction of effects in several organs, the animal as a whole will show characteristic syndromes. Some syndromes result inevitably in death. Others may or may not be lethal, depending on the extent of the tissue damage. The time of appearance of the syndromes, their duration, and the survival of the organism depend on many factors. Whole body acute doses of radiation produce the same spectrum of Central Nervous System (CNS), Gastrointestinal (GI) and Bone Marrow (BM) injury in man as was described for animals. Damage to the skin, ovary and testis are an integral and important part of the symptoms. (author) [pt

  13. Analysis of the health of a group exposed to low doses of ionizing radiation

    International Nuclear Information System (INIS)

    Diaz Ledesma, F.; Crespo, H.

    1997-01-01

    In order to evaluate the effects of exposure to low radiation doses, the health status of professional staff exposed to ionizing radiation is investigated. Based on archived material of medical and radiation exposure records taken over a time span of 13 years, a variety of medical parameters are explored. Findings of surveys made are given. (author)

  14. Overview of the ISS Radiation Environment Observed during the ESA EXPOSE-R2 Mission in 2014-2016

    Science.gov (United States)

    Dachev, T. P.; Bankov, N. G.; Tomov, B. T.; Matviichuk, Yu. N.; Dimitrov, Pl. G.; Häder, D.-P.; Horneck, G.

    2017-11-01

    The radiation risk radiometer-dosimeter (R3D)-R2 solid-state detector performed radiation measurements at the European Space Agency EXPOSE-R2 platform outside of the Russian "Zvezda" module at the International Space Station (ISS) from 24 October 2014 to 11 January 2016. The ISS orbital parameters were average altitude of 415 km and 51.6° inclination. We developed special software and used experimentally obtained formulas to determine the radiation flux-to-dose ratio from the R3DR2 Liulin-type deposited-energy spectrometer. We provide for the first time simultaneous, long-term estimates of radiation dose external to the ISS for four source categories: (i) galactic cosmic ray particles and their secondary products; (ii) protons in the South Atlantic Anomaly region of the inner radiation belt (IRB); (iii) relativistic electrons and/or bremsstrahlung in the outer radiation belt (ORB); and (iv) solar energetic particle (SEP) events. The latter category is new in this study. Additionally, in this study, secondary particles (SP) resulting from energetic particle interaction with the detector and nearby materials are identified. These are observed continuously at high latitudes. The detected SPs are identified using the same sorting requirements as SEP protons. The IRB protons provide the highest consistent hourly dose, while the ORB electrons and SEPs provide the most extreme hourly doses. SEPs were observed 11 times during the study interval. The R3DR2 data support calculation of average equivalent doses. The 30 day and 1 year average equivalent doses are much smaller than the skin and eyes doses recommendations by the National Council on Radiation Protection (Report 132), which provides radiation protection guidance for Low Earth Orbit.

  15. Effects of small doses of ionising radiation

    International Nuclear Information System (INIS)

    Doll, R.

    1998-01-01

    Uncertainty remains about the quantitative effects of doses of ionising radiation less than 0.2 Sv. Estimates of hereditary effects, based on the atomic bomb survivors, suggest that the mutation doubling dose is about 2 Sv for acute low LET radiation, but the confidence limits are wide. The idea that paternal gonadal irradiation might explain the Seascale cluster of childhood leukaemia has been disproved. Fetal irradiation may lead to a reduction in IQ and an increase in seizures in childhood proportional to dose. Estimates that doses to a whole population cause a risk of cancer proportional to dose, with 0.1 Sv given acutely causing a risk of 1%, will need to be modified as more information is obtained, but the idea that there is a threshold for risk above this level is not supported by observations on the irradiated fetus or the effect of fallout. The idea, based on ecological observations, that small doses protect against the development of cancer is refuted by the effect of radon in houses. New observations on the atomic bomb survivors have raised afresh the possibility that small doses may also have other somatic effects. (author)

  16. Guide on medical management of persons exposed in radiation accidents

    International Nuclear Information System (INIS)

    1990-01-01

    The present guide has been prepared in order to provide guidance to medical and para-medical personnel regarding medical management of the different types of radiation accidents. It discusses briefly the physical aspects and biological effect of radiation, for the benefit of those who have not specialised in radiation medicine. The diagnosis, medical management and follow-up of persons involved in different types of radiation accidents are also dealt with. The implementation of the procedures described calls for organisation of appropriate facilities and provision of requisite equipment as well as education and training of the staff. It is emphasised that major radiation accidents are rare events and the multi-disciplinary nature of the response required to deal with them calls for proper planning and continuous liaison among plant management, radiation protection personnel, first-aid assistants and medical and paramedical staff. The organisation and conduct of emergency drills may help in maintaining preparedness of the medical facilities for efficient management of radiation casualities. (original). 64 refs., tabs., figs

  17. Persons occupationally exposed to radiation in the Federal Land Niedersachen

    International Nuclear Information System (INIS)

    Ruschkowski, E. von; Kalmbach, U.

    1984-01-01

    The results of the physical radiation protection control according to section 62 of the ordinance on radiation protection (StrlSchVO) or section 40 of the roentgen ordinance (ROeV) for the report year 1982 are presented in table form. They show persons and plants under the legal obligation of being monitored events of excess radiation exposure, frequency distribution of the annual doses, survey of incorporation measurements and results of the first and following medical checks according to section 42 ROeV and section 71 StrlSchVO. In the year of report, no personnel contaminations occurred. (HSCH) [de

  18. Small and Exposed: Debt Accumulation in Canada’s Small Provinces

    Directory of Open Access Journals (Sweden)

    Ronald D. Kneebone

    2015-05-01

    the last three years of our period of analysis, policy-induced deficits have the province sliding in the wrong direction, adding 2.6 percentage points of GDP to its accumulated operating account deficit. Notably, there appears to be little difference between NDP and PC governments when it comes to policy-induced debt accumulation. The one distinction appears to be that the PCs have tended to begin governing by adding debt, and reducing it later, while the NDP has followed the opposite pattern. The record of P.E.I.’s policy decisions, meanwhile, has been the reverse of Manitoba’s: After managing to keep its debt in check for 20 years, the government since 1999 has added 11 percentage points of GDP to its accumulated operating account deficit almost entirely as the result of policy choices. Particularly worrisome is the recent rapid accumulation of debt between 2009 and 2014. In the meantime, Nova Scotia continues working to undo the risky policies of the “lost decade” from 1984 to 1994, where PC governments increased the debt ratio by nearly a third. In all four provinces the ability to keep debt ratios under control will depend heavily on constraining the growth in health-care spending. Health spending has soared in all provinces since 1999–2000, the most extreme case being in New Brunswick where the share of revenue spent on health has leaped from 25.4 to 35.9 per cent. Even if these provinces cannot change the fact that they are small and exposed, and are stuck with the specific economic risks that entails, they do have the ability to make policy choices that mitigate the length and severity of the effects of exogenous shocks. With three of the provinces (save P.E.I. expected to enjoy faster growth in 2015, the work in better preparing their economies for shocks should begin right away.

  19. Study on the immunity state of mouse exposed to mobile phone radiation during embryonic phase

    International Nuclear Information System (INIS)

    Pei Yinhui; Gao Hui

    2008-01-01

    Objective: To study the effect of mobile phone radiation on mouse which exposed to radiation during embryonic phase. Methods: Pregnant mice were exposed to mobile phone radiation. The mice's netrophile phage percentage and spleen lymphocyte transformation rate were detected respectively 2 months after birth. Results: The netrophile phage percentage of experimental mice was seemly the same as that of control group, and there was no significant difference (P>0.05), but the spleen transformation rate showed the diverse trend. Conclusion: The specific cellular immunity of mice, which ex- posed to mobile phone radiation during embryonic phase, was seen to be in a state of decreasement. (authors)

  20. The extent of unwanted infrared photoacoustic signals from polymer sampling tubings exposed to ultraviolet radiation

    NARCIS (Netherlands)

    Bicanic, D.; Solyom, A.; Angeli, G.; Wegh, H.; Postumus, M.; Jalink, H.

    1995-01-01

    The extent of unwanted photoacoustic (PA) signals due to volatiles released from various polymer tubing materials [transparent, red and black polyethylene (PE), polymer of tetrafluorethylene (PTFE) and copolymer of tetrafluorethylene and hexafluorethylene (FEP)] when exposed to 245 nm radiation was

  1. Under-exposed. And if radiations were good for you?

    International Nuclear Information System (INIS)

    Gay, Michel

    2016-01-01

    This book is in fact a synthesis of an American publication (Under-Exposed). The author, with its characteristic style, aims at giving a positive perception of nuclear energy, at denying catastrophist speeches on nuclear energy, and more particularly on radioactivity: low doses are not dangerous, and even can be useful for our health and well-being, notably in many spa resorts. Thus, he also aims at struggling against what he considers as an ecological obscurantism

  2. Oxidative stress in mollusks Biomphalaria Glabrata exposed to gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Luanna R.S.; Augusto, Ricielle L.; Siqueira, Williams N.; Luna Filho, Ricardo L.C.; Pereira, Dewson R.; França, Elvis J.; Silva, Edvane B.; Melo, Ana M.M.A., E-mail: luannaribeiro_lua@hotmail.com, E-mail: williams.wns@gmail.com, E-mail: ejfranca@gmail.com, E-mail: edvborges@yahoo.com, E-mail: luannaribeiro_lua@hotmail.com, E-mail: williams.wns@gmail.com, E-mail: ricardolclf@hotmail.com, E-mail: dewson.rocha@gmail.com, E-mail: s, E-mail: amdemelo@hotmail.com, E-mail: ricielleaugusto@gmail.com, E-mail: williams.wns@gmail.com, E-mail: ejfranca@gmail.com [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil); Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil)

    2017-11-01

    Ionizing radiation can cause biological changes in different organisms such as mollusks from Biomphalaria glabrata species, in which alterations could be observed in the reproductive system of the specimens, prejudicing fertility and fecundity. As the changes may occur due to the lipid peroxidation caused by the action of free radicals on the gonads, the objective of this work was to evaluate the oxidative damage caused by the exposure of B. glabrata mollusks to different doses of gamma radiation. In addition, efforts were carried out to standardize a sensitive and low-cost technique for detecting negative effects caused by high doses of ionizing radiation. For this, each mollusk group (n = 10) was submitted to 0 (control), 10, 15, 20 and 25 Gy (Gammacell- {sup 60}Co, dose rate 3.532 kGy/h). The TBARS method was applied for the quantification of lipid peroxidation of the gonads of the mollusks after 24 and 48 h. ANOVA, followed by the mean comparison (Tukey) at the 5% of significance level, indicated high concentrations of TBARS in the gonads after 24 h. Otherwise, after 48 h, differences for TBARS concentrations were not significant at the 95% confidence level, determining that the action of free radicals from ionizing radiation on cell membranes mainly occurred within 24 h after irradiation. (author)

  3. Oxidative stress in mollusks Biomphalaria Glabrata exposed to gamma radiation

    International Nuclear Information System (INIS)

    Silva, Luanna R.S.; Augusto, Ricielle L.; Siqueira, Williams N.; Luna Filho, Ricardo L.C.; Pereira, Dewson R.; França, Elvis J.; Silva, Edvane B.; Melo, Ana M.M.A.

    2017-01-01

    Ionizing radiation can cause biological changes in different organisms such as mollusks from Biomphalaria glabrata species, in which alterations could be observed in the reproductive system of the specimens, prejudicing fertility and fecundity. As the changes may occur due to the lipid peroxidation caused by the action of free radicals on the gonads, the objective of this work was to evaluate the oxidative damage caused by the exposure of B. glabrata mollusks to different doses of gamma radiation. In addition, efforts were carried out to standardize a sensitive and low-cost technique for detecting negative effects caused by high doses of ionizing radiation. For this, each mollusk group (n = 10) was submitted to 0 (control), 10, 15, 20 and 25 Gy (Gammacell- "6"0Co, dose rate 3.532 kGy/h). The TBARS method was applied for the quantification of lipid peroxidation of the gonads of the mollusks after 24 and 48 h. ANOVA, followed by the mean comparison (Tukey) at the 5% of significance level, indicated high concentrations of TBARS in the gonads after 24 h. Otherwise, after 48 h, differences for TBARS concentrations were not significant at the 95% confidence level, determining that the action of free radicals from ionizing radiation on cell membranes mainly occurred within 24 h after irradiation. (author)

  4. Radiation dose assessment for occupationally exposed workers in ...

    African Journals Online (AJOL)

    2017-01-31

    Jan 31, 2017 ... with the legislation and safety requirements, has not yet ... occupational exposure to ionising radiation such as X-rays. This study was hence ... of health care service delivery in Malawi (i.e. regional level, district level and ...

  5. Radiation research contracts: Biological effects of small radiation doses

    International Nuclear Information System (INIS)

    Hug, O.

    1959-01-01

    According to its Statute the IAEA has to fulfil a dual function - to help individual countries in solving their specific problems and to undertake tasks in the common interest of all its Member States. With this latter aim in mind the Agency has placed a number of research contracts with national research institutes. The purpose and scope of two of them is described below by the scientists responsible for their execution. The Agency has contributed to this work by putting at the institutes' disposal scientists from its own staff apparatus and financial aid.IAEA placed a research contract concerning the effects of small radiation doses on cells, in particular on nervous cells, with the Pharmacological Institute of the University of Vienna. This Institute appeared well suited to deal with the problem owing to the type of its previous research work. The Director, Prof. Franz Bruecke, and his collaborator Dr. Otto Kraupp, have long been interested in the functioning of the nervous system and in the influence of different drugs upon it. It was particularly fortunate that the electrical properties and functions of cells had been measured by a method specially developed at this Institute. From the above mentioned observations one could expect that instantaneous reactions of cells to radiation would also lead to changes of the electrical status. Consequently, this method is now being applied to the research undertaken for IAEA. Different cells of plants and animals, ranging from algae to muscle fibres of mammals, were chosen as objects. So far changes of potentials-had been observed only during irradiation with very high doses. During these investigations another useful test for small radiation doses was developed, namely the measurement of the through-flow of an artificial blood solution through the blood vessels of an intestinal loop. It was observed that a few seconds after irradiation the flow rate diminishes, and returns to its normal level only when irradiation ends

  6. Radiation research contracts: Biological effects of small radiation doses

    Energy Technology Data Exchange (ETDEWEB)

    Hug, O

    1959-01-15

    According to its Statute the IAEA has to fulfil a dual function - to help individual countries in solving their specific problems and to undertake tasks in the common interest of all its Member States. With this latter aim in mind the Agency has placed a number of research contracts with national research institutes. The purpose and scope of two of them is described below by the scientists responsible for their execution. The Agency has contributed to this work by putting at the institutes' disposal scientists from its own staff apparatus and financial aid.IAEA placed a research contract concerning the effects of small radiation doses on cells, in particular on nervous cells, with the Pharmacological Institute of the University of Vienna. This Institute appeared well suited to deal with the problem owing to the type of its previous research work. The Director, Prof. Franz Bruecke, and his collaborator Dr. Otto Kraupp, have long been interested in the functioning of the nervous system and in the influence of different drugs upon it. It was particularly fortunate that the electrical properties and functions of cells had been measured by a method specially developed at this Institute. From the above mentioned observations one could expect that instantaneous reactions of cells to radiation would also lead to changes of the electrical status. Consequently, this method is now being applied to the research undertaken for IAEA. Different cells of plants and animals, ranging from algae to muscle fibres of mammals, were chosen as objects. So far changes of potentials-had been observed only during irradiation with very high doses. During these investigations another useful test for small radiation doses was developed, namely the measurement of the through-flow of an artificial blood solution through the blood vessels of an intestinal loop. It was observed that a few seconds after irradiation the flow rate diminishes, and returns to its normal level only when irradiation ends

  7. Toward Imaging of Small Objects with XUV Radiation

    Science.gov (United States)

    Sayrac, Muhammed; Kolomenski, Alexandre A.; Boran, Yakup; Schuessler, Hans

    The coherent diffraction imaging (CDI) technique has the potential to capture high resolution images of nano- or micron-sized structures when using XUV radiation obtained by high harmonic radiation (HHG) process. When a small object is exposed to XUV radiation, a diffraction pattern of the object is created. The advances in the coherent HHG enable obtaining photon flux sufficient for XUV imaging. The diffractive imaging technique from coherent table top XUV beams have made possible nanometer-scale resolution imaging by replacing the imaging optics with a computer reconstruction algorithm. In this study, we present our initial work on diffractive imaging using a tabletop XUV source. The initial investigation of imaging of a micron-sized mesh with an optimized HHG source is demonstrated. This work was supported in part by the Robert A. Welch Foundation Grant No. A1546 and the Qatar Foundation under the grant NPRP 8-735-1-154. M. Sayrac acknowledges support from the Ministry of National Education of the Republic of Turkey.

  8. Moessbauer studies of hemoglobin in erythrocytes exposed to neutron radiation

    Energy Technology Data Exchange (ETDEWEB)

    Niemiec, Katarzyna; Kaczmarska, Magdalena; Buczkowski, Mateusz [AGH University, Faculty of Physics and Computer Science, Department of Medical Physics and Biophysics (Poland); Fornal, Maria [Collegium Medicum, Jagiellonian University, Department of Internal Medicine and Gerontology (Poland); Pohorecki, Wladyslaw [AGH University, Faculty of Energy and Fuels (Poland); Matlak, Krzysztof; Korecki, Jozef [AGH University, Faculty of Physics and Computer Science, Department of Solid State Physics (Poland); Grodzicki, Tomasz [Collegium Medicum, Jagiellonian University, Department of Internal Medicine and Gerontology (Poland); Burda, Kvetoslava, E-mail: kvetoslava.burda@fis.agh.edu.pl [AGH University, Faculty of Physics and Computer Science, Department of Medical Physics and Biophysics (Poland)

    2012-03-15

    We studied radiation effects on the stability of various states of hemoglobin (Hb) in red blood cells (RBC) irradiated with a very low dose of neutron rays, 50 {mu}Gy. We investigated RBCs isolated from blood of healthy donors. Moessbauer spectroscopy was applied to monitor different forms of Hb. Our results show, for the first time, that oxyhemoglobin (OxyHb) and deoxyhemoglobin (DeoxyHb) are two Hb forms sensitive to such a low neutron radiation. Both Hbs change into a new Hb form (Hb{sub irr}). Additionally, OxyHb transfers into HbOH/H{sub 2}O, which under our experimental conditions is resistant to the action of neutron rays.

  9. Lymphocytic reactions in persons occupationally exposed to ionizing radiation

    International Nuclear Information System (INIS)

    Bliznakov, V.; Nikolov, A.

    1989-01-01

    The most frequent reasons for deviations of hematological indicies in radiological and X-ray personnel are discussed. The dynamics of lymphocyte count in individuals working in the city of Sofia is tabulated for a period of 12 years. The data show that the number of deviations from the norm (accepted as 1.929±0.908 g/l) reduced in time, which is one of the features of radiation syndrome. 24.23% of the persons investigated have had lymphocytosis. The following most common reasons for this are mentioned: increased cummulative radiation dose, focal infections, alergie, neurosis, tyreotoxicosis, virus infections, leucosis. The second and third investigations of such persons before applying any therapy are proposed in order to precisize the diagnosting

  10. Photosynthetic carbon reduction by seagrasses exposed to ultraviolet A radiation

    Science.gov (United States)

    1979-01-01

    The seagrasses Halophila engelmannii, Halodule wrightii, and Syringodium filiforme were examined for their intrinsic sensitivity to ultraviolet-A-UV-A and ultraviolet-B-UV-B radiation. The effect of UV-A on photosynthetically active radiation (PAR) was also determined. Ultraviolet-A and ultraviolet-B were studied with emphasis on the greater respective environmental consequence in terms of seagrass distribution and abundance. Results indicate that an intrinsic sensitivity to UV-A alone is apparent only in Halophila, while net photosynthesis in Halodule and Syringodium seems unaffected by the level of UV-A provided. The sensitivity of Halophila to UV-A in the absense of (PAR) indicates that the photosynthetic reaction does not need to be in operation for damage to occur. Other significant results are reported.

  11. Dependence of malformation upon gestational age and exposed dose of gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sung-Ho; Lee, Jong-Hwan; Oh, Heon; Kim, Se-Ra [Chonnam National Univ., Kwangju (Korea, Republic of). Coll. of Veterinary Medicine; Lee, Cha-Soo; Jo, Sung-Kee; Kim, Tae-Hwan; Lee, Yun-Sil

    2001-09-01

    In order to evaluate the importance of gestational age and the dose-incidence relationship by gamma radiation, pregnant ICR mice at gestational days from 2.5 to 15.5 days post-coitus (p.c.) were exposed to a single dose of 2.0 Gy and also at day 11.5 after conception, which was the most sensitive stage for the induction of major congenital malformations. The animals were sacrificed on day 18 of gestation and the fetuses were examined for mortality, growth retardation, changes in head size and other morphological abnormalities. The only demonstrable effect of irradiation during the pre-implantation period was an increase in prenatal mortality. Resorptions were maximal on exposure at day 2.5 after conception. The pre-implantation irradiated embryos which survived did not show any major fetal abnormalities. A small head, growth retardation, a cleft palate, dilatation of the cerebral ventricle, a renal pelvis, and abnormalities of the extremities and tail after exposure were prominent during the organogenesis period, especially on day 11.5 of gestation. As for the dose-incidence relationship, the incidence of a small head, growth-retarded fetuses, a cleft palate, dilatation of cerebral ventricle and abnormalities of the extremities in live fetuses rose as the radiation dose increased. The result indicated that the late period of organogenesis in the development of the brain, skull and extremities of a mouse was a particularly sensitive phase. The threshold doses of radiation that induced a cleft palate and dilatation of the cerebral ventricle, and abnormal extremities were between 1.0 and 2.0 Gy, and between 0.5 and 1.0 Gy, respectively. (author)

  12. Dependence of malformation upon gestational age and exposed dose of gamma radiation

    International Nuclear Information System (INIS)

    Kim, Sung-Ho; Lee, Jong-Hwan; Oh, Heon; Kim, Se-Ra; Lee, Cha-Soo; Jo, Sung-Kee; Kim, Tae-Hwan; Lee, Yun-Sil

    2001-01-01

    In order to evaluate the importance of gestational age and the dose-incidence relationship by gamma radiation, pregnant ICR mice at gestational days from 2.5 to 15.5 days post-coitus (p.c.) were exposed to a single dose of 2.0 Gy and also at day 11.5 after conception, which was the most sensitive stage for the induction of major congenital malformations. The animals were sacrificed on day 18 of gestation and the fetuses were examined for mortality, growth retardation, changes in head size and other morphological abnormalities. The only demonstrable effect of irradiation during the pre-implantation period was an increase in prenatal mortality. Resorptions were maximal on exposure at day 2.5 after conception. The pre-implantation irradiated embryos which survived did not show any major fetal abnormalities. A small head, growth retardation, a cleft palate, dilatation of the cerebral ventricle, a renal pelvis, and abnormalities of the extremities and tail after exposure were prominent during the organogenesis period, especially on day 11.5 of gestation. As for the dose-incidence relationship, the incidence of a small head, growth-retarded fetuses, a cleft palate, dilatation of cerebral ventricle and abnormalities of the extremities in live fetuses rose as the radiation dose increased. The result indicated that the late period of organogenesis in the development of the brain, skull and extremities of a mouse was a particularly sensitive phase. The threshold doses of radiation that induced a cleft palate and dilatation of the cerebral ventricle, and abnormal extremities were between 1.0 and 2.0 Gy, and between 0.5 and 1.0 Gy, respectively. (author)

  13. Induction of adaptive response in human blood lymphocytes exposed to radiofrequency radiation.

    Science.gov (United States)

    Sannino, Anna; Sarti, Maurizio; Reddy, Siddharth B; Prihoda, Thomas J; Vijayalaxmi; Scarfì, Maria Rosaria

    2009-06-01

    The incidence of micronuclei was evaluated to assess the induction of an adaptive response to non-ionizing radiofrequency (RF) radiation in peripheral blood lymphocytes collected from five different human volunteers. After stimulation with phytohemagglutinin for 24 h, the cells were exposed to an adaptive dose of 900 MHz RF radiation used for mobile communications (at a peak specific absorption rate of 10 W/kg) for 20 h and then challenged with a single genotoxic dose of mitomycin C (100 ng/ml) at 48 h. Lymphocytes were collected at 72 h to examine the frequency of micronuclei in cytokinesis-blocked binucleated cells. Cells collected from four donors exhibited the induction of adaptive response (i.e., responders). Lymphocytes that were pre-exposed to 900 MHz RF radiation had a significantly decreased incidence of micronuclei induced by the challenge dose of mitomycin C compared to those that were not pre-exposed to 900 MHz RF radiation. These preliminary results suggested that the adaptive response can be induced in cells exposed to non-ionizing radiation. A similar phenomenon has been reported in cells as well as in animals exposed to ionizing radiation in several earlier studies. However, induction of adaptive response was not observed in the remaining donor (i.e., non-responder). The incidence of micronuclei induced by the challenge dose of mitomycin C was not significantly different between the cells that were pre-exposed and unexposed to 900 MHz RF radiation. Thus the overall data indicated the existence of heterogeneity in the induction of an adaptive response between individuals exposed to RF radiation and showed that the less time-consuming micronucleus assay can be used to determine whether an individual is a responder or non-responder.

  14. The fate of chromosomal aberrations in 137Cs-exposed individuals in the Goiania radiation accident

    International Nuclear Information System (INIS)

    Ramalho, A.T.; Nascimento, A.C.

    1991-01-01

    Following the Goiania radiation accident, lymphocytes from 110 exposed or potentially exposed individuals were analyzed for the frequencies of chromosomal aberrations (dicentrics and centric rings) to estimate absorbed radiation dose. Dose estimates for 21 subjects exceeded 1.0 Gy, and for eight subjects they exceeded 4.0 Gy. Four of the subjects died. After the emergency period, a cytogenetic follow-up of 10 of the highest exposed patients was started. The results suggest that the average disappearance half-time of lymphocytes containing dicentric and centric rings was 130 d, which is shorter than the usually accepted value of 3 y reported in the literature

  15. Proposal to integrate the service on radiation hygiene at the primary health care services for workers exposed to ionizing radiation

    International Nuclear Information System (INIS)

    Frometa Suarez, Ileana; Lopez Pumar, Georgina; Gonzalez Amil, Melva

    1998-01-01

    The National Health System implemented in the last few years a new pattern of primary attention for workers by creating doctors offices in work centers. At the same time, the Ministry of Public Health (MINSAP) carries the medical surveillance of the staff exposed to ionizing radiation. This work proposes a program to integrate the consulting room on radiation hygiene to primary health care services for workers that work with ionizing radiation sources, aiming to ameliorate and improve them

  16. Immune cells in Chernobyl radiation workers exposed to low-dose irradiation

    International Nuclear Information System (INIS)

    Bazyka, D.; Chumak, A.; Byelyaeva, N.; Gulaya, N.; Margytich, V.; Thevenon, C.; Guichardant, M.; Lagarde, M.

    2002-01-01

    the aim of this work was to study immune response parameters in Chernobyl emergency and recovery operation radiation workers and nuclear industry workers exposed under professional limits. The monohydroxylated fatty acid content in peripheral blood mononuclear cell of radiation workers compared to unexposed control at the 12-th year after Chernobyl NPP accident was studied too

  17. Histomorphometric Evaluation of the Small Coronary Arteries in Rats Exposed to Industrial Noise

    Directory of Open Access Journals (Sweden)

    Ana Lousinha

    2015-05-01

    Full Text Available Morphological changes induced by industrial noise (IN have been experimentally observed in several organs. Histological observations of the coronary arteries showed prominent perivascular tissue and fibrosis among IN-exposed rats. The effects on the small arteries are unknown. Objective: To evaluate the histomorphometric changes induced by IN on rat heart small arteries. Methods: Twenty Wistar rats exposed to IN during a maximum period of seven months and 20 age-matched controls were studied. Hearts were transversely sectioned from ventricular apex to atria and a mid-ventricular fragment was selected for analysis. The histological images were obtained with an optical microscope using 400× magnifications. A total of 634 arterial vessels (298 IN-exposed and 336 controls were selected. The mean lumen-to-vessel wall (L/W and mean vessel wall-to-perivascular tissue (W/P ratios were calculated using image J software. Results: There were no differences between exposed and control animals in their L/W ratios (p = 0.687 and time variations in this ratio were non-significant (p = 0.110. In contrast, exposed animals showed lower W/P ratios than control animals (p < 0.001, with significant time variations (p = 0.004. Conclusions: Industrial noise induced an increase in the perivascular tissue of rat small coronary arteries, with significant development of periarterial fibrosis.

  18. Longitudinal study among children of parents exposed to ionizing radiation

    International Nuclear Information System (INIS)

    Herrmann, T.

    1992-01-01

    In view of the fact that there is a general lack of experience in consultancy to patients treated by radiation therapy, the Radiotherapy Dept. of the 'Carl Gustav Carus' Medical Academy in Dresden started to carry out investigations among the off-spring of radiotherapy patients of procreative age. The first phase of the study carried out with the help of the residents' registration system of the former GDR found 21 children of patients treated by radiotherapy. Encouraged by the first experience, the author of the paper since then has continued the investigations on a regular and comprehensive basis, collecting the data of all offspring of patients treated by the Dept., and performing follow-up examinations every five years (1975, 1980, 1985), assisted by an experienced pediatrician. A major result of the study is the fact that it confirms the permissible dose to the testes or ovaries which has been observed so far for radiation treatment, but has been the subject of controversial debates among experts. Doses exceeding 1.5 Gy to a man, or 3.0 Gy to a woman, applied at the usual clinical conditions, have to be regarded as sterilising doses. The author developes conclusions and advice for medical consultancy to patients. (orig./MG) [de

  19. Potential radiation dose from eating fish exposed to actinide contamination

    International Nuclear Information System (INIS)

    Emery, R.M.; Klopfer, D.C.; Baker, D.A.; Soldat, J.K.

    1980-01-01

    The purpose of this work is to establish a maximum potential for transporting actinides to man via fish consumption. The study took place in U-Pond, a nuclear waste pond on the Hanford Site. It has concentrations of 238 U, 238 Pu, /sup 239,240/Pu and 241 Am that are approximately three orders of magnitude greater than background levels. Fish living in the pond contain higher actinide concentrations than those observed in fish from any other location. Experiments were performed in U-pond to determine maximum quantities of actinides that could accumulate in fillets and whole bodies of two centrarchid fish species. Doses to hypothetical consumers were then estimated by assuming that actinide behavior in their bodies was similar to that defined for Standard Man by the International Commission on Radiological Protection. Results indicate that highest concentrations occurring in bluegill or bass muscle after more than a year's exposure to the pond would not be sufficient to produce a significant radiation dose to a human consumer, even if he ate 0.5 kg (∼1 lb) of these fillets every day for 70 years. Natural predators (heron or coyote), having lifetime diets of whole fish from U-Pond, would receive less radiation dose from the ingested actinides than from natural background sources. 34 refs., 5 figs., 4 tabs

  20. Potential radiation dose from eating fish exposed to actinide contamination

    International Nuclear Information System (INIS)

    Emery, R.M.; Klopfer, D.C.; Baker, D.A.; Soldat, J.K.

    1981-01-01

    The purpose of this work is to establish a maximum potential for transporting actinides to man via fish consumption. The study took place in U-pond, a nuclear waste pond on the Hanford Site. It has concentrations of 238 U, 238 Pu, sup(239,240)Pu and 241 Am that are approx. 3 orders of magnitude greater than background levels. Fish living in the pond contain higher actinide concentrations than those observed in fish from any other location. Experiments were performed in U-Pond to determine maximum quantities of actinides that could accumulate in fillets and whole bodies of two centrarchid fish species. Doses to hypothetical consumers were then estimated. Results indicate that highest concentrations occurring in bluegill or bass muscle after more than a year's exposure to the pond would not be sufficient to produce a significant radiation dose to a human consumer, even if he ate 0.5 kg (of the order of 1 lb) of these fillets every day for 70 yr. Natural predators (heron or coyote), having lifetime diets of whole fish from U-Pond, would receive less radiation dose from the ingested actinides than from natural background sources. (author)

  1. Study of External Radiation Expose Dose on Hands of Nuclear Medicine Workers

    International Nuclear Information System (INIS)

    Park, Jun Chul; Pyo, Sung Jae

    2012-01-01

    The aims of this study are to assess external radiation exposed doses of body and hands of nuclear medicine workers who handle radiation sources, and to measure radiation exposed doses of the hands induced by a whole body bone scan with high frequency and handling a radioactive sources like 99m Tc-HDP and 18 F-FDG in the PET/CT examination. Skillful workers, who directly dispense and inject from radiation sources, were asked to wear a TLD on the chest and ring finger. Then, radiation exposed dose and duration exposed from daily radiation sources for each section were measured by using a pocket dosimeter for the accumulated external doses and the absorbed dose to the hands. In the survey of four medical institutions in Incheon Metropolitan City, only one of four institutions has a radiation dosimeter for local area like hands. Most of institutions uses radiation shielding devices for the purpose of protecting the body trunk, not local area. Even some institutions were revealed not to use such a shielding device. The exposed doses on the hands of nuclear medicine workers who directly handles radioactive sources were approximately twice as much as those on the body. The radiation exposure level for each section of the whole body bone scan with high frequency and that of the PET/CT examination showed that radiation doses were revealed in decreasing order of synthesis of radioactive medicine and installation to a dispensing container, dispensing, administering and transferring. Furthermore, there were statistically significant differences of radiation exposure doses of the hands before and after wearing a syringe shielder in administration of a radioactive sources. In this study, although it did not reach the permissible effective dose for nuclear medicine, the occupational workers were exposed by relatively higher dose level than the non-occupational workers. Therefore, the workers, who closely exposed to radioactive sources should be in compliance with safety

  2. Photosynthethic carbon reduction by seagrasses exposed to ultraviolet B radiation

    Science.gov (United States)

    1979-01-01

    The species of seagrasses were selected on the basis of their dominance in the marine system, contribution to total productivity, and importance to the life histories of organisms in the Indian River lagoon system along the central Florida east coast. The three seagrasses were Halophilia engelmannii, Halodule wrightii, and Syringodium filiforme. These seagrasses form an excellent experimental system as their areas of dominance fall more or less along a natural gradient of UV-B and photosynthetically active radiation (PAR) penetration. The sensitivity of photosynthesis in the seagrasses was determined and their photosynthetic response to levels of UV-B simulating atmospheric ozone depletion was monitored. Further experiments explore the possible attenuation or repair of UV-B induced photosynthetic inhibition by PAR, the role of epiphytic growth upon seagrasses as a protective UV-B shield, and the inhibition of photosynthesis in response to UV-A is studied.

  3. Thermoluminescence of sulfated zircon exposed to gamma radiation

    International Nuclear Information System (INIS)

    Rubio, E.; Castano, V.M.; Mendoza A, E.; Gonzalez, P.R.

    2003-01-01

    In this work, the thermoluminescent (Tl) signal induced by gamma radiation in zirconia and sulfated zirconia samples embedded in Ptfe pellets is reported and discussed. In this case, samples were obtained through sol-gel method using zirconium n-propoxide and H 2 SO 4 as precursors, and later were subjected to thermal treatment at 600 C to obtain, the tetragonal phase accordingly to X-ray diffraction analysis. Experimental results show that the thermoluminescent glow peak depends on both, the crystalline structure and sulfate concentration. Two maximum peaks were observed located at 147 C and 274 C arising from the electronic transitions. Tl response as a function of the absorbed dose shows a linear increase for a wide of range exposure as well as good stability in time. The high sensitivity, dose linearity and signal stability of this material open the potential possibility to be used for the dosimetry applications. (Author)

  4. Bio-dosimetry for radiation-exposed individuals

    International Nuclear Information System (INIS)

    Sauvaigo, Sylvie; Chapuis, Violaine; Caillat, Sylvain; Sarrazy, Fanny; Breton, Jean

    2013-01-01

    Exposure of civil populations to genotoxic chemicals or radioactive hazard is an increased concern. It is not only an industrial risk (chemistry plant accident for example) but also a national security problem due to the threat of radiological and nuclear terrorism. It is important to anticipate the need of a bio-dosimetry tool aimed at identifying exposed population in the absence of acute syndrome, in order to assure the medical care that would prevent carcinogenic consequences. DNA repair is a bio-marker of exposure to geno-toxics in individuals. A DNA repair signature can be assessed from Peripheral Blood Mononuclear Cells (PBMCs) that reflects the exposure history of the individuals, using a functional enzymatic assay on bio-chip. A proof of concept was obtained using PBMCs from patients undergoing radiotherapy regimen. We identified two classes of responses among patients, if we except a very atypical signature in one patient that could reflect defects in DNA repair. Interestingly, repair of the major oxidative lesions increased during the course of the radiotherapy. We propose to implement this fast, quantitative, possibly automatized assay to identify bio-markers of exposure to geno-toxics and to validate the exposure bio-markers through ex vivo exposure of blood from volunteers. (authors)

  5. Risk of cataract among medical staff in neurosurgical department occupationally exposed to radiation

    International Nuclear Information System (INIS)

    Stankova-Mileva, I.; Vassileva, J.; Djounova, J.

    2012-01-01

    In this study we present the risk of cataract among medical staff in neurosurgical department occupationally exposed to radiation compared to those of non-radiation workers. Cataract is the most common degenerative opacity of the crystalline lens developing with aging. Other risk factors for cataract are: infrared and ultraviolet radiation, systemic diseases (diabetes, hypertonic disease), eye diseases (glaucoma, high myopia), drugs (steroids), etc. High risk of developing cataract we find among staff occupationally exposed to radiation during operations - interventional cardiologists and neurosurgeons. This study includes 30 people between 33 and 60 years of age working in neurosurgical department and control group (the same amount and age of people not exposed to radiation in their work). After visual acuity measurement, the lens was examined by retroillumination method (red reflex) and using a bio microscope. The patients were asked for presence of ocular and systemic diseases, eye trauma, drug, alcohol and tobacco abuse and for how many years they work in this department. There was one case with cataract among neurosurgeons. The doctor doesn't have eye or systemic diseases, doesn't take any drugs and is not alcohol or tobacco abuser. In the control group there were two persons with subcapsular cataract but they have diabetes. Radiation is one of the risk factors for cataract. Continuing of this epidemiological survey will provide further knowledge on the potential risk of occupational radiation-induced cataract among neurosurgical staff and will contribute for optimization of radiation protection. (authors)

  6. Monitoring the genetic health of persons in Goiania accidentally exposed to ionizing radiation from caesium-137

    International Nuclear Information System (INIS)

    Da Cruz, A.D.; Glickman, B.W.

    1998-01-01

    This work describes the long term genetic monitoring of the Goiania population exposed to ionizing radiation from 137 Cs, using cytogenetic and molecular endpoints. Cytogenetically, micronucleus frequencies differentiated groups exposed to different levels of radiation. Two molecular methods were employed: 1) the hprt clonal assay, involving in vitro selection of 6-thioguanine-resistant hprt mutant clones which were characterized at the molecular level using RT-PCR and genomic analysis. Ionizing radiation exposure initially elevated hprt mutation frequency which gradually diminished, so that no significant increase was observed four and a half years after original exposure. The spectrum of hprt mutations recovered from ten individuals exposed to relatively high doses of radiation revealed a fourfold increase in the frequency of A:T → G:C transitions. The increase is consistent with the effects of ionizing radiation in prokaryotes and lower eukaryotes. Additionally, a twofold increase in the frequency of deletions was observed which may reflect radiation induced DNA strand breakage; 2) determination of microsatellite instability using fluorescent PCR and genomic DNA from mononuclear cells. The frequency distributions of somatic microsatellite alterations in exposed and non-exposed populations were not different. Our assay lacked sensitivity to discriminate between spontaneous and induced microsatellite instability and therefore, is not suitable for population monitoring. Finally, we estimated the risk associated with radiation exposure for the exposed Goiania population. The estimated genetic risk of dominant disorders in the first post-exposure generation was increased nearly twenty-fourfold. The risk of carcinogenesis was increased by a factor of 1.5. (author)

  7. Monitoring the genetic health of persons in Goiania accidentally exposed to ionizing radiation from caesium-137

    Energy Technology Data Exchange (ETDEWEB)

    Da Cruz, A D; Glickman, B W [Centre for Environmental Health, Department of Biology, University of Victoria, Victoria, BC (Canada)

    1998-12-01

    This work describes the long term genetic monitoring of the Goiania population exposed to ionizing radiation from {sup 137}Cs, using cytogenetic and molecular endpoints. Cytogenetically, micronucleus frequencies differentiated groups exposed to different levels of radiation. Two molecular methods were employed: (1) the hprt clonal assay, involving in vitro selection of 6-thioguanine-resistant hprt mutant clones which were characterized at the molecular level using RT-PCR and genomic analysis. Ionizing radiation exposure initially elevated hprt mutation frequency which gradually diminished, so that no significant increase was observed four and a half years after original exposure. The spectrum of hprt mutations recovered from ten individuals exposed to relatively high doses of radiation revealed a fourfold increase in the frequency of A:T {yields} G:C transitions. The increase is consistent with the effects of ionizing radiation in prokaryotes and lower eukaryotes. Additionally, a twofold increase in the frequency of deletions was observed which may reflect radiation induced DNA strand breakage; (2) determination of microsatellite instability using fluorescent PCR and genomic DNA from mononuclear cells. The frequency distributions of somatic microsatellite alterations in exposed and non-exposed populations were not different. Our assay lacked sensitivity to discriminate between spontaneous and induced microsatellite instability and therefore, is not suitable for population monitoring. Finally, we estimated the risk associated with radiation exposure for the exposed Goiania population. The estimated genetic risk of dominant disorders in the first post-exposure generation was increased nearly twenty-fourfold. The risk of carcinogenesis was increased by a factor of 1.5. (author)

  8. Biomarkers in volunteers exposed to mobile phone radiation.

    Science.gov (United States)

    Söderqvist, Fredrik; Carlberg, Michael; Hardell, Lennart

    2015-06-01

    For some time it has been investigated whether low-intensity non-thermal microwave radiation from mobile phones adversely affects the mammalian blood-brain barrier (BBB). All such studies except one have been either in vitro or experimental animal studies. The one carried out on humans showed a statistically significant increase in serum transthyretin (TTR) 60 min after finishing of a 30-min microwave exposure session. The aim of the present study was to follow up on the finding of the previous one using a better study design. Using biomarkers analyzed in blood serum before and after the exposure this single blinded randomized counterbalanced study, including 24 healthy subjects aged 18-30 years that all underwent three exposure conditions (SAR(10G)=2 W/kg, SAR(10G)=0.2 W/kg, sham), tested whether microwaves from an 890-MHz phone-like signal give acute effects on the integrity of brain-shielding barriers. Over time, statistically significant variations were found for two of the three biomarkers (TTR; β-trace protein); however, no such difference was found between the different exposure conditions nor was there any interaction between exposure condition and time of blood sampling. In conclusion this study failed to show any acute clinically or statistically significant effect of short term microwave exposure on the serum levels of S100β, TTR and β-trace protein with a follow up limited to two hours. The study was hampered by the fact that all study persons were regular wireless phone users and thus not naïve as to microwave exposure. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  9. Radiation damage in silicon exposed to high-energy protons

    International Nuclear Information System (INIS)

    Davies, Gordon; Hayama, Shusaku; Murin, Leonid; Krause-Rehberg, Reinhard; Bondarenko, Vladimir; Sengupta, Asmita; Davia, Cinzia; Karpenko, Anna

    2006-01-01

    Photoluminescence, infrared absorption, positron annihilation, and deep-level transient spectroscopy (DLTS) have been used to investigate the radiation damage produced by 24 GeV/c protons in crystalline silicon. The irradiation doses and the concentrations of carbon and oxygen in the samples have been chosen to monitor the mobility of the damage products. Single vacancies (and self-interstitials) are introduced at the rate of ∼1 cm -1 , and divacancies at 0.5 cm -1 . Stable di-interstitials are formed when two self-interstitials are displaced in one damage event, and they are mobile at room temperature. In the initial stages of annealing the evolution of the point defects can be understood mainly in terms of trapping at the impurities. However, the positron signal shows that about two orders of magnitude more vacancies are produced by the protons than are detected in the point defects. Damage clusters exist, and are largely removed by annealing at 700 to 800 K, when there is an associated loss of broad band emission between 850 and 1000 meV. The well-known W center is generated by restructuring within clusters, with a range of activation energies of about 1.3 to 1.6 eV, reflecting the disordered nature of the clusters. Comparison of the formation of the X centers in oxygenated and oxygen-lean samples suggests that the J defect may be interstitial related rather than vacancy related. To a large extent, the damage and annealing behavior may be factorized into point defects (monitored by sharp-line optical spectra and DLTS) and cluster defects (monitored by positron annihilation and broadband luminescence). Taking this view to the limit, the generation rates for the point defects are as predicted by simply taking the damage generated by the Coulomb interaction of the protons and Si nuclei

  10. Automated measurement of pulmonary emphysema and small airway remodeling in cigarette smoke-exposed mice.

    Science.gov (United States)

    Laucho-Contreras, Maria E; Taylor, Katherine L; Mahadeva, Ravi; Boukedes, Steve S; Owen, Caroline A

    2015-01-16

    COPD is projected to be the third most common cause of mortality world-wide by 2020((1)). Animal models of COPD are used to identify molecules that contribute to the disease process and to test the efficacy of novel therapies for COPD. Researchers use a number of models of COPD employing different species including rodents, guinea-pigs, rabbits, and dogs((2)). However, the most widely-used model is that in which mice are exposed to cigarette smoke. Mice are an especially useful species in which to model COPD because their genome can readily be manipulated to generate animals that are either deficient in, or over-express individual proteins. Studies of gene-targeted mice that have been exposed to cigarette smoke have provided valuable information about the contributions of individual molecules to different lung pathologies in COPD((3-5)). Most studies have focused on pathways involved in emphysema development which contributes to the airflow obstruction that is characteristic of COPD. However, small airway fibrosis also contributes significantly to airflow obstruction in human COPD patients((6)), but much less is known about the pathogenesis of this lesion in smoke-exposed animals. To address this knowledge gap, this protocol quantifies both emphysema development and small airway fibrosis in smoke-exposed mice. This protocol exposes mice to CS using a whole-body exposure technique, then measures respiratory mechanics in the mice, inflates the lungs of mice to a standard pressure, and fixes the lungs in formalin. The researcher then stains the lung sections with either Gill's stain to measure the mean alveolar chord length (as a readout of emphysema severity) or Masson's trichrome stain to measure deposition of extracellular matrix (ECM) proteins around small airways (as a readout of small airway fibrosis). Studies of the effects of molecular pathways on both of these lung pathologies will lead to a better understanding of the pathogenesis of COPD.

  11. A Review of the New European Technical Recommendations for Monitoring Individuals Occupationally Exposed to External Radiation

    International Nuclear Information System (INIS)

    Dijk, J.W.E. van; Alves, J.G.; Ambrosi, P.; Bartlett, D.T.; Currivan, L.; Fantuzzi, E.; Kamenopoulou, V.

    2013-01-01

    This paper reviews the revised Technical Recommendations for Monitoring Individuals Occupationally Exposed to External Radiation as issued by the European Commission as Radiation Protection 160. These recommendations are aimed at all stakeholders in radiation protection dosimetry with an emphasis in the responsible technical staff of approved dosimetry services. This paper briefly touches each Chapter and ends with a more in depth section on the uncertainty evaluation of dose measurements. -- Highlights: ► Recommendations on all aspects of running an approved dosimetry service. ► Radiation protection framework. ► Metrology of personal dosimeters. ► QC and QA of individual monitoring

  12. Evaluation of Medical and Dosimetric Monitoring of the Personnel Exposed to Ionizing Radiations in Industry

    International Nuclear Information System (INIS)

    Hammou, A.; Ben Hariz, N.; Ben Omrane, L.

    2008-01-01

    Increasing use of the ionizing radiations in industry, in particular in the field of the non destructive testing (NDT) exposes the operators to low radiation doses. Therefore Radiation protection measures in this field are needed. We report the results of a survey carried out on a sample of 50 workers in NDT in Tunisia; Our purpose is to evaluate the professional training levels in radiation protection of the operators, to determine their exposure dose rate. In case of over-exposure, to determine the causes, to evaluate the medical follow-up, and to propose adequate recommendations

  13. Reduction in life span on normal human fibroblasts exposed to low-dose radiation in heavy-ion radiation field

    International Nuclear Information System (INIS)

    Suzuki, Masao; Yamaguchi, Chizuru; Yasuda, Hiroshi; Uchihori, Yukio; Fujitaka, Kazunobu

    2003-01-01

    We studied the effect of in vitro life span in normal human fibroblasts exposed to chronically low-dose radiation in heavy-ion radiation field. Cells were cultured in a CO 2 incubator, which was set in the irradiation room for biological study of heavy ions in the Heavy Ion Medical Accelerator in Chiba (HIMAC) at National Institute of Radiological Sciences (NIRS), and exposed to scattered radiations produced with heavy-ion beams throughout the life span of the cell population. Absorbed dose, which was measured using a thermoluminescence dosimeter(TLD) and a Si-semiconductor detector, was to be 1.4 mGy per day when operating the HIMAC machine for biological experiments. The total population doubling number of the exposed cells reduced to 79-93% of non-exposed control cells in the three independent experiments. There is evidence that the exposure of chronically low-dose radiation in heavy-ion radiation field promotes the life-span reduction in cellular level. (author)

  14. Responses of populations of small mammals to ionizing radiation

    International Nuclear Information System (INIS)

    Kitchings, J.T.

    1978-01-01

    Studies on the responses of small mammals to ionizing radiation have, over the past 30 years, documented numerous effects on direct mortality, reproduction, the hemopoietic systems, and radionuclide metabolism. Three general findings have resulted from past efforts: (1) ionizing radiation is a factor in environmental stress, (2) the response of wild small mammals to ionizing radiation is a mosaic of varying radiosensitivities interacting with environmental variables, and (3) one of the most sensitive organismal processes to radiation is reproduction. While an excellent understanding of the biological effects resulting from high or intermediate-level radiation exposures has been developed, this is not the case for effects of low-level doses

  15. Findings of thyroid ultrasonography in patients with hypothyroidism exposed to ionizing radiation due to Chernobyl accident

    International Nuclear Information System (INIS)

    Grid'ko, O.M.

    1997-01-01

    Comparative analysis of the findings of clinical and ultrasound study of the thyroid gland in 403 participants of the accident clean-up irradiated in the 'iodine' period and 57 patients with hypothyroidism (of them, 46 were exposed to radiation in the 'iodine' period and 11 in 'non-iodine' one) was carried out. The disease dynamics was investigated in 81 patients with acute radiation sickness. The structural changes suggest different ways of hypothyroidism development in the exposed persons and manifest themselves in two main clinical forms of the disease, atrophic and hypertrophic ones

  16. Chemical effects and their consequences for individuals occupationally exposed to ionizing radiation

    International Nuclear Information System (INIS)

    Salvador, C.; Kahl, G.G.; Kühn, P.; Zottis, A.D.; Flôr, R.C.

    2017-01-01

    By legal determination, workers exposed to ionizing radiation should use individual dosimeters in the most exposed region of the body, designed to estimate the effective dose, as well as radiation protective clothing to minimize occupational exposures. Regarding dosimetry, in most cases it is perceived that the monthly values of exposure are within the limits of normality, however, even being below the limit can not rule out the possibility of damage that the low dose of ionizing radiation can cause. The objective of this article is to highlight the main chemical effects caused by exposure to ionizing radiation, especially biochemical damage in DNA, chromosomal aberrations and the correlation with the exposure of occupationally exposed individuals, as well as individuals from the public. A bibliographic search was carried out in indexed databases from February to April 2017 with the following descriptors: Radiation Ionizing, DNA Damage and Occupational Exposure. In the 'Science Direct' database were found 1205 articles, in the 'Scopus' 19 articles, in the 'Web of Science' 83 articles, in the 'PubMed' 22 articles and in the 'VHL' 60 articles related to the theme. It was concluded that exposure to ionizing radiation can affect the DNA molecule despite its repair mechanisms, which may result in genotoxicity. It has been reported a correlation between occupationally exposed individuals and chromosomal aberrations, demonstrating that even low doses of ionizing radiation can compromise the genetic material integrity of exposed workers, leading to the need for a periodic cytogenetic study for this group of workers

  17. Evaluation of cytogenetic damage in nuclear medicine personnel occupationally exposed to low-level ionising radiation

    International Nuclear Information System (INIS)

    Garaj-Vrhovac, V.; Kopjar, N.; Poropat, M.

    2005-01-01

    Despite intensive research over the last few decades, there still remains considerable uncertainty as to the genetic impact of ionising radiation on human populations, particularly at low levels. The aim of this study was to provide data on genetic hazards associated with occupational exposure to low doses of ionising radiation in nuclear medicine departments. The assessment of DNA damage in peripheral blood lymphocytes of medical staff was performed using the chromosome aberration (CA) test. Exposed subjects showed significantly higher frequencies of CA than controls. There were significant inter-individual differences in DNA damage within the exposed population, indicating differences in genome sensitivity. Age and gender were not confounding factors, while smoking enhanced the levels of DNA damage only in control subjects. The present study suggests that chronic exposure to low doses of ionising radiation in nuclear medicine departments causes genotoxic damage. Therefore, to avoid potential genotoxic effects, the exposed medical personnel should minimise radiation exposure wherever possible. Our results also point to the significance of biological indicators providing information about the actual risk to the radiation exposed individuals.(author)

  18. UDS and SCE in lymphocytes of persons occupationally exposed to low levels of ionizing radiation

    International Nuclear Information System (INIS)

    Tuschl, H.; Kovac, R.; Altmann, H.

    1983-03-01

    Unscheduled DNA synthesis induced by 'in vitro' UV-irradiation was investigated in lymphocytes of persons occupationally exposed to low doses of ionizing radiation (maximum registered radiation dose: 98 mrad/month). For radiation exposures >14 mrad/month, above background level, increased rates of UDS after in vitro UV-irradiation of lymphocytes were found. The bromodeoxyuridine differential chromatid labeling technique was applied to the examination of spontaneous and mytomycin C induced sister chromatid exchanges in the same population. No statistically significant difference could be determined in spontaneously occurring SCEs, while MMC induced SCEs were significantly reduced in persons exposed to radiation doses >14 mrad/month, thus indicating increased repair capability for DNA lesions inflicted by a second insult after protracted low dose irradiation. (Author) [de

  19. The effect of melatonin on eye lens of rats exposed to ultraviolet radiation.

    Science.gov (United States)

    Anwar, M M; Moustafa, M A

    2001-05-01

    We investigated the influence of exogenously administered melatonin on adult rats eye lenses exposed to ultraviolet radiation (UV) A and B ranging from 356-254 nm irradiation at 8 microW/cm(2). Rats exposed to this range of UV for 15 min for one week showed a significant (PUV-radiation significantly (PUV irradiation, may be the main cause of lens opacification. Melatonin injection with radiation significantly reduced (Pradiation, SOD and GSH-Px enzyme activities increased significantly (PUV radiation was as effective as melatonin treatment concurrent with UV irradiation. We conclude that melatonin may protect the eye lens from the damaging effects of UV exposure, and its actions protect lens from oxidative stress, elevating Ca(2+) levels, which are considered as an important causes of cataractogenesis.

  20. Analysis of emotionality and locomotion in radio-frequency electromagnetic radiation exposed rats.

    Science.gov (United States)

    Narayanan, Sareesh Naduvil; Kumar, Raju Suresh; Paval, Jaijesh; Kedage, Vivekananda; Bhat, M Shankaranarayana; Nayak, Satheesha; Bhat, P Gopalakrishna

    2013-07-01

    In the current study the modulatory role of mobile phone radio-frequency electromagnetic radiation (RF-EMR) on emotionality and locomotion was evaluated in adolescent rats. Male albino Wistar rats (6-8 weeks old) were randomly assigned into the following groups having 12 animals in each group. Group I (Control): they remained in the home cage throughout the experimental period. Group II (Sham exposed): they were exposed to mobile phone in switch-off mode for 28 days, and Group III (RF-EMR exposed): they were exposed to RF-EMR (900 MHz) from an active GSM (Global system for mobile communications) mobile phone with a peak power density of 146.60 μW/cm(2) for 28 days. On 29th day, the animals were tested for emotionality and locomotion. Elevated plus maze (EPM) test revealed that, percentage of entries into the open arm, percentage of time spent on the open arm and distance travelled on the open arm were significantly reduced in the RF-EMR exposed rats. Rearing frequency and grooming frequency were also decreased in the RF-EMR exposed rats. Defecation boli count during the EPM test was more with the RF-EMR group. No statistically significant difference was found in total distance travelled, total arm entries, percentage of closed arm entries and parallelism index in the RF-EMR exposed rats compared to controls. Results indicate that mobile phone radiation could affect the emotionality of rats without affecting the general locomotion.

  1. Radiation risk factors in incidence anortality among exposed individuals of East Kazakhstand m

    Directory of Open Access Journals (Sweden)

    Kazbek Apsalikov

    2014-01-01

    Full Text Available Introduction: Lengthy clinical and epidemiological studies at the Research Institute of Radiation Medicine and Ecology have discovered basic patterns of long-term effects from ionizing radiation in population groups exposed to radiation risk. Methodology for calculating injury from radiation risk factors has been developed and implemented to minimize the effects of the Semipalatinsk nuclear test site (SNTS. Material and methods: We analyzed materials from the database of the Scientific Medical Register that were exposed to radiation as a result of SNTS. We analyzed both male and female populations of the Abay, Beskaragai and Zhanasemei, Kokpekti (control areas of East-Kazakhstan region (EKR from 2008-2012. These populations were split into three groups allocated by the generation. The first group represented persons born from the period of 01/01/1930 -08/01/1949 and their children born from the period of 10/09/1949-12/31/1962. The second group were persons born after 01/01/1963. The third group served as the control and were persons who immigrated to these areas after 1990. Results: There was an increased incidence of cancer (21.5%, p < 0.000734, cardiovascular diseases (10.2%; respiratory problems (9.6%, gastrointestinal issues (9.1%, p < 0.00371-0.00679 in the first group. The effect of the radiation dose has not been fully stuided among the subjects in the second group.The major causes of excess mortality in the first group were neoplams (30.6%, hypertension (23.8%, and myocardial infarction (22.6%. The effects of radiation influenced mortality in the second group were 2-2.5 times lower than the first group.Conclusion: There is a correlation between the size of the radiation dose, the risk profile, and age at the moment of radiation exposure with trends of morbidity and mortality in the radiation exposed areas.

  2. Cytogenetic and hematological studies in the workers occupationally exposed to low levels of ionizing radiation

    International Nuclear Information System (INIS)

    Zakeri, F.; Honarjoo, M.; Rajab pour, M.; Zahadat, A.; Ahmad pour, M.J.; Asghari, K.

    2007-01-01

    Complete text of publication follows. Objective: This study was aimed at detecting both the incidence of chromosomal aberrations and changes in the hematological parameters as biomarkers of possible radiation injury among workers occupationally exposed to low levels of ionizing radiation and detecting the dose-effect relationship. Methods: Samples of peripheral blood were collected from 38 male industrial radiographers exposed to ionizing radiation for 1-16 years and from 24 age- and sex-matched healthy blood donors without radiation history served as control group. All radiation workers were routinely monitored with film badge. Cytogenetic analysis in peripheral blood lymphocytes assessed by the conventional chromosome aberration assay and at least 200 metaphases for each person were scored. The collected blood samples were analyzed for hematological assay using an automatic analyzer Sysmex KX-21, where 14 different parameters were computerized. Mann-Whitney U test was used to compare the frequencies of the unstable aberrations and hematological parameters between test and control groups. Dose-effect relationship and the influence of age and duration of employment was tested by regression analysis. Results and conclusion: The mean frequencies of dicentric and acentric chromosome aberrations were significantly higher in the exposed group than in the control group (P< 0.0005). No correlation between chromosomal aberrations and physical dose and age was observed in the exposed group. Also there is no clear relation between chromosome damage and duration of exposure. However, the increase in chromosome aberrations in the exposed group was not followed by a corresponding hematological depression. The average values of hematological indices were within the reference levels and did not show any significant differences with control group. A tendency of decreasing the absolute lymphocyte count within the referential levels was the only hematological effect in radiation

  3. Metabolic changes in broiler chickens exposed to low dose of ionising radiation

    International Nuclear Information System (INIS)

    Danova, D.; Kafka, I.; Kalenicova, Z.; Petrovova, E.; Toropila, M.

    2008-01-01

    In our experiment broiler chickens, 28-day old, were exposed to single whole- body dose 3 Gy of ionising radiation in time gap 3., 7., 14. and 21 day. We applied zinc to organism of chicks after irradiation. We observed changes of concentrations of cholesterol and glucose in blood serum. From obtained results it is evident that despite relative high resistance of poultry to irradiation, it reacts strongly to ionising radiation even at laboratory levels. (authors)

  4. Increased concentration of Pseudomonas aeruginosa and Staphylococcus sp. in small animals exposed to aerospace environments

    Science.gov (United States)

    Guthrie, R. K.

    1976-01-01

    The effects of increased concentrations of PSEUDOMONAS AERUGINOSA AND STAPHYLOCOCCUS in the total bacterial flora of small animals exposed to simulated spacecraft environments were evaluated. Tests to detect changes in infectivity, effects of antibiotic treatments, immune responses to bacterial antigens, and effectiveness of immune responses in the experimental environment were conducted. The most significant results appear to be the differences in immune responses at simulated altitudes and the production of infection in the presence of a specific antibody.

  5. Clinical course of brain stroke in the persons exposed to ionizing radiation under the production conditions

    International Nuclear Information System (INIS)

    Bouchmanov, A.

    2000-01-01

    The purpose was to study the risk factors and clinical course of brain strokes in professionally exposed workers being employed in plutonium production in comparison with a control group. The method and materials of study -clinical supervision and clinical database creation on 162 cases of brain stroke (128 males and 34 females) developed among professionally exposed workers. Age of patient varied from 21 to 68 years (in average -51.6 y.). The control group consisted of patients with the same diagnosis, worked on the same enterprise, but non-exposed to radiation. Data on the totally accumulated dose of external gamma radiation were received on the base of the individual dosimeters (from 0.1 cSv to 52 cSv, in average about 13 cSv); the plutonium-239 body content was estimated accordingly to the level of urine radionuclide excretion (from 0.4 kBq to 1.6 kBq, in average about 0.33 kBq). Muscle's hypertinsion and pathological great-toe reflexes in paretic legs and hands, hemianopsia, impressive and ataxic aphasia prevailed in the patients with ischemic brain strokes in system of internal carotid artery, exposed to radiation. The changes of muscle's tension, ataxia and nystagmus were marked more often in the professionals with ischemic brain strokes in system of vertebrobasilar artery. The illness proceeded more easy and with smaller frequency of frustration of consciousness and algesthesia, irrespective of a type ischemic brain strokes in the people exposed to ionizing radiation, than in patients of non-irradiated group. It was found that the arterial hypertension appeared to be the main risk factor for the brain stroke in both groups of patients (in 81.48% and 91.15% of cases). There was no marked differences in significance of risk factors and in main clinical parameters of various types of ischemic brain strokes among the patients professionally exposed to radiation in comparison with a control group. (author)

  6. How much can be learned from populations exposed to low levels of radiation

    International Nuclear Information System (INIS)

    Gilbert, E.S.

    1984-05-01

    The assessment of health effects from low-level exposure to radiation is a matter of considerable controversy. Many of the problems in analyzing and interpreting data on populations exposed to low levels of radiation are well illustrated by a current study of the effects on mortality of occupational exposure to radiation at the Hanford plant. The conclusion drawn is that the amount that can be learned from the Hanford population, and other populations exposed to low levels of radiation, is extremely limited. The data are not adequate to determine reliable estimates of risks, or to investigate the appropriateness of various models. Although there are problems in using data from populations exposed at high levels to estimate risks of low level exposure to radiation, the problems in obtaining such estimates directly are even more severe. Thus data from populations such as the Japanese A-bomb survivors and the British ankylosing spondylitis patients must continue to serve as our primary source of information on radiation effects. 27 references, 3 tables

  7. Flow cytometric assessment of DNA damage in the fish Catla catla (Ham.) exposed to gamma radiation

    International Nuclear Information System (INIS)

    Anbumani, S.; Mohankumar, Mary N.; Selvanayagam, M.

    2012-01-01

    Environmental mutagens such as ionizing radiation and chemicals induce DNA damage in a wide variety of organisms. The International Commission on Radiological Protection (lCRP) has recently emphasized the need to protect non-human biota from the potential effects of ionizing radiation. Radiation exposures to non-humans can occur as a result of low-level radioactive discharges into the environment. Molecular genetic effects at low-level radiation exposures are largely unexplored and systematic studies using sensitive biomarkers are required to assess DNA damage in representative non-human species. The objective of the study was to detect DNA damage in the fish Catla catla exposed to gamma radiation using flow cytometry at different time intervals. Increases in the coefficient of variation (CV) of the G 0 /G 1 peak, indicating abnormal DNA distributions were observed in fish exposed to gamma radiation than in controls. Significant increase in the CV was observed from day 12-90 and thereafter decreased. This increase in CV might be due to DNA damage in the cell populations at G 0 /G 1 phase or deletions and duplications caused by improper repair of chromosomes in the cell-cycle machinery. Ionizing radiation induced cell-cycle perturbations and apoptosis were also observed after gamma radiation exposure. (author)

  8. Tumor induction by small doses ionising radiation

    International Nuclear Information System (INIS)

    Putten, L.M. van

    1981-01-01

    Tumour induction by low radiation doses is in general a non-linear process. However, two exceptions are well known: myeloid leukemia in Rf mice and mamma tumours in Sprague-Dawley rats. The hypothesis that radiation is highly oncogenic in combination with cell growth stimuli, as reaction to massive cell death after damage of nuclear DNA, is applied to man and the consequences are discussed. (Auth.)

  9. Thermoluminescence properties of undoped and nitrogen-doped CVD diamond exposed to gamma radiation

    International Nuclear Information System (INIS)

    Barboza-Flores, M.; Gastelum, S.; Cruz-Zaragoza, E.; Melendrez, R.; Chernov, V.; Pedroza-Montero, M.; Favalli, A.

    2008-01-01

    It is known that the thermoluminescence (TL) performance of CVD diamond depends on the impurity concentration and doping materials introduced during growing. We report on the TL properties of undoped and 750 ppm nitrogen-doped CVD diamond grown on (0 0 1) silicon substrate. The samples were exposed to gamma radiation from a Gammacell 200 Nordion irradiator in the 10-500 Gy dose range at 627 mGy/min dose rate. The nitrogen-doped CVD diamond sample exhibited a TL glow curve peaked around 537 K and a small shoulder about 411 K and a linear dose behavior in the 10-60 Gy dose range. In contrast, the undoped specimen showed a 591 K peaked TL glow curve and linear dose response for 10-100 Gy doses. However, both samples displayed a non-linear dose response for doses higher than 100 Gy. The doping effects seem to cause a higher TL efficiency, which may be attributed to the differences in the diamond bonding and amorphous carbon on the CVD samples as well as to the presence of nitrogen. In addition, the nitrogen content may produce some structural and morphological surface effects, which may account for the distinctive TL features and dose response of the diamond samples

  10. Family history and medical examination of occupationally exposed employees against ionizing radiation

    International Nuclear Information System (INIS)

    Heinemann, G.

    2000-01-01

    Searching for individual radiosensitivity could improve the quality of the medical examination of occupationally exposed employees and thus provide real protection of the individual against ionizing radiation. For this purpose genetic family history should be recorded by a skilled interviewer. (orig.) [de

  11. A study of immunological reactions in dogs exposed to prolonged chronic radiation

    Science.gov (United States)

    Konstantinova, I. V.; Grigoryev, Y. G.; Markelov, B. A.; Skryabin, A. S.; Zemskov, V. M.; Vasilyev, I. S.; Veysfeyler, Y. K.; Iokai, I.

    1974-01-01

    Immunomorphological studies on dog tissues exposed to long term gamma irradiation show that the number of cells containing antibodies increased and that the blast transformation reaction was activated. Prolonged radiation did not cause a reliable change in the synthesis of nucleic acids in spleen cells.

  12. Evaluation of chromosomal aberrations in radiologists and medical radiographers chronically exposed to ionising radiation

    International Nuclear Information System (INIS)

    Kasuba, V.; Rozgaj, R.; Jazbec, A.

    2005-01-01

    Chromosomal aberrations are fairly reliable indicators of damage induced by ionising radiation. This study included 180 radiologists and medical radiographers (technicians) and 90 controls who were not occupationally exposed to ionising radiation. All exposed subjects were routinely monitored with film badge, and none was exposed to a radiation dose exceeding the limit for occupational exposure recommended by the International Commission on Radiological Protection (ICRP). Two hundred metaphases for each person were scored. The frequencies of acentric fragments, dicentrics, ring chromosomes and chromosomal exchanges were determined and compared to those obtained in the control group. Chromosome aberrations were analysed using Poisson regression for profession, age, sex, smoking and years of exposure. Age, smoking, diagnostic exposure to X-rays and occupation were found to correlate with the occurrence of acentric fragments. The influence of exposure duration on the frequency of acentric fragments was greater in medical radiographers than in radiologists. Smoking and sex were found to correlate with the occurrence of dicentric chromosomes, which were more common in men than in women. As chromosome aberrations exceeded the expected level with respect to the absorbed dose, our findings confirm the importance of chromosome analysis as a part of regular medical check-up of subjects occupationally exposed to ionising radiation.(author)

  13. Cytogenetic monitoring of hospital workers exposed to low-level ionizing radiation

    International Nuclear Information System (INIS)

    Bigatti, P.; Lamberti, L.; Ardito, G.; Armellino, F.

    1988-01-01

    In the present study the cytogenetic effects in hospital workers exposed to low-level radiation were evaluated. Samples of peripheral blood were collected from 63 subjects working in radiodiagnostics and from 30 subjects, working in the same hospitals, who were used as controls. A higher number of cells with chromosome-type aberrations (CA) was observed in the exposed workers vs. the controls and the difference was statistically significant (p<0.05). No correlation was, on the contrary, found between CA and years of exposure. A significant difference was observed in the incidence of cells with CA between smokers and non-smokers, but in the control group only. In contrast, in the workers exposed to ionizing radiation, the frequency of cells with CA was very similar in smokers and non-smokers. 13 refs.; 4 tabs

  14. Cytogenetic monitoring of personnel occupationally exposed to microwave radiation of GEM radar

    International Nuclear Information System (INIS)

    Garaj-Vrhovac, Vera; Gajski, Goran; Brumen, Vlatka

    2008-01-01

    In the present study we analyzed and followed-up on the DNA damaging effects of microwave radiation of GEM radar equipment within microwave field of 10 μW/cm 2 to 10 mW/cm 2 in personnel occupationally exposed to frequency range of 1.5 GHz to 10.9 GHz. The single cell gel electrophoresis (SCGE)/comet assay as a tool for the bio monitoring of individuals accidentally, environmentally or occupationally exposed to physical or chemical agents was used to evaluate possible genotoxic effect on peripheral human blood lymphocytes. The comet assay is a method that allows efficient determination of single strand breaks (SSB) and double-strand breaks (DSB), as well as alkali-labile sites in the DNA of single cells. The comet assay was carried out under alkaline conditions. We measured the baseline comet assay effect in whole blood samples. Parameter of the comet assay was studied in workers occupationally exposed to microwave radiation of GEM radar and in corresponding unexposed control subjects. It was found that in the subjects who were occupationally exposed to microwave radiation, the levels of DNA damage increased compare to control group and showed interindividual variations. As a measure of DNA damage tail length was used, calculated from the centre of the head and presented in micrometers (μm). Mean value of exposed group was 13.54±1.44 as opposed to control mean value that was 13.15±1.39. Differences between mean tail lengths were statistically significant (P<0.05, ANOVA). The results of this study indicate that individuals occupationally exposed to microwave frequency of GEM radar equipment may experience an increased genotoxic risk, emphasizing the importance of individual bio monitoring, limiting exposure and radiation safety programs. (author)

  15. Cytogenetic Follow-up Study of Population Occupationally Exposed to Nonionizing Radiation

    International Nuclear Information System (INIS)

    Garaj-Vrhovac, V.; Kasuba, V.; Vojvodic, S.

    1998-01-01

    The aim of this investigation was to analyse the results of a four year follow- up study of chromosome aberrations in a population occupationally exposed to microwave radiation. The study included a group of 30 healthy volunteers - radar technicians occupationally exposed to microwave radiation and a group of 30 healthy controls from the general population. The average duration of employment of the exposed subjects was 16 years. The chromosome aberrations assay was carried out on 48 h culture of lymphocytes. Microwave power density was measured with Raham model 4A (General Microwave Corporation, Farmingdale, NY) at different workplaces. The measurements of electromagnetic field power density distribution at different workplaces show that during an ordinary workday the examinees stay in zones with power density below 5 mW/cm 2 with a frequency range of 1250-1350 MHz. The chromosomal type of aberrations in the exposed group during the 4-year follow up study was predominantly higher than in the control group. The total percentage of chromosome aberrations for the exposed group in the first year of the study was 2.36%, in the second 1.43%, in the third 2.88%, and in the fourth year 2.60%, while for the control group was 1.39%. In every year of investigation in exposed group manifested dicentric chromosomes, while in last two years ring chromosome also detected. Mutagenic changes in the somatic cells detected in exposed subjects pointed to the fact that these cellular damages can be related to continuous occupational exposure to microwave radiation. (author)

  16. Sunlight-exposed biofilm microbial communities are naturally resistant to chernobyl ionizing-radiation levels.

    Science.gov (United States)

    Ragon, Marie; Restoux, Gwendal; Moreira, David; Møller, Anders Pape; López-García, Purificación

    2011-01-01

    The Chernobyl accident represents a long-term experiment on the effects of exposure to ionizing radiation at the ecosystem level. Though studies of these effects on plants and animals are abundant, the study of how Chernobyl radiation levels affect prokaryotic and eukaryotic microbial communities is practically non-existent, except for a few reports on human pathogens or soil microorganisms. Environments enduring extreme desiccation and UV radiation, such as sunlight exposed biofilms could in principle select for organisms highly resistant to ionizing radiation as well. To test this hypothesis, we explored the diversity of microorganisms belonging to the three domains of life by cultivation-independent approaches in biofilms developing on concrete walls or pillars in the Chernobyl area exposed to different levels of radiation, and we compared them with a similar biofilm from a non-irradiated site in Northern Ireland. Actinobacteria, Alphaproteobacteria, Bacteroidetes, Acidobacteria and Deinococcales were the most consistently detected bacterial groups, whereas green algae (Chlorophyta) and ascomycete fungi (Ascomycota) dominated within the eukaryotes. Close relatives to the most radio-resistant organisms known, including Rubrobacter species, Deinococcales and melanized ascomycete fungi were always detected. The diversity of bacteria and eukaryotes found in the most highly irradiated samples was comparable to that of less irradiated Chernobyl sites and Northern Ireland. However, the study of mutation frequencies in non-coding ITS regions versus SSU rRNA genes in members of a same actinobacterial operational taxonomic unit (OTU) present in Chernobyl samples and Northern Ireland showed a positive correlation between increased radiation and mutation rates. Our results show that biofilm microbial communities in the most irradiated samples are comparable to non-irradiated samples in terms of general diversity patterns, despite increased mutation levels at the single

  17. 'Rogue' cells observed in children exposed to radiation from the Chernobyl accident

    International Nuclear Information System (INIS)

    Sevan'kaev, A.V.; Tsyb, A.F.; Zhloba, A.A.; Moiseenko, V.V.; Skrjabin, A.M.; Climov, V.M.

    1993-01-01

    Eight 'rogue' lymphocyte metaphases containing a large number of aberrant chromosomes were noted during a survey of chromosomal damage in 328 Belarussian children. The study population comprised children of families living in territory contaminated by radiation from the Chernobyl accident. The majority of the sample had been evacuated within 1 week from very heavily polluted territory to areas that had received much less fallout. Two hundred cells were scored per subject and one rogue cell was found in a child exposed in utero; one in a child conceived after the accident and six in the postnatally exposed group. The possibility that the damage was due to exposure to radio-iodine concentrated in the thyroid gland, or to radiation from incorporated hot particles' of an alpha or beta/gamma emitter is discussed. It is concluded that the damage to these cells is unlikely to have been caused by radiation. (Author)

  18. Quantitative and qualitative changes in the lymphocytes of rats chronically exposed to radiation and chemical factors

    International Nuclear Information System (INIS)

    Ivanov, V.V.

    1986-01-01

    Quantitative and qualitative characteristics of lymphocytes in peripheral blood, thymus and spleen of rats chronically exposed to combined external γ-radiation trichlorfon pesticide effect have been studied. It is shown that chronical combined trichlorfon and γ irradiation effect is accompanied by suppression of lymphopoiesis already at the early stages of the experience. The observed effects are formed depending on both daily and cumulative doses of the effect. The development of the combined effect is based on the summation of effects of chronical effect of ionizing radiation and pesticide. The revealed changes in lymphocytes population exposed to radiation and chemical factors can lead to substantial decrease of natural immunity thereby decreasing to various diseases

  19. role of some transition metals and metalloproteins on oxidative stress formation among ionizing radiation exposed workers

    International Nuclear Information System (INIS)

    Michael, M.I.

    2004-01-01

    this study was established to evaluate the role of working in radiation field for different prolonged periods on some oxidant/antioxidant parameters and to estimate the role of other additional factors such as age, smoking and inflammation on the progress of oxidative stress on the chosen volunteers. one hundred and twenty six male volunteers working in the nuclear research center and hot laboratories center were assessed in the present study, they were arranged as 70 radiation exposed workers and 56 control individuals. the radiation exposed workers were rearranged into 50 non-smokers, non-hypertensive and non-diabetics; 10 individuals were smokers, non-hypertensive, non-diabetic and other 10 volunteers with increased erythrocyte sedimentation rate (esr), non-smokers, non-hypertensive and non-diabetics

  20. Compensation for damage to workers health exposed to ionizing radiation in Argentina

    CERN Document Server

    Sobehart, L J

    2003-01-01

    The objective of this report is to analyze the possibility to establish a scheme to compensate damage to workers health exposed to ionizing radiation in Argentina for those cases in which it is possible to assume that the exposure to ionizing radiation is the cause of the cancer suffered by the worker. The proposed scheme is based on the recommendations set out in the 'International Conference on Occupational Radiation Protection: Protecting Workers against Exposure to Ionization Radiation, held in Geneva, Switzerland, August 26-30, 2002. To this end, the study analyzes the present state of scientific knowledge on cancer causation due to genotoxic factors, and the accepted form of the doses-response curve, for the human beings exposure to ionization radiation at low doses with low doses rates. Finally, the labor laws and regulations related to damage compensation; in particular the present Argentine Labor Law; the National Russian Federal Occupational Radiological Health Impairment and Workmen Compensation, t...

  1. Health surveillance of persons occupationally exposed to ionizing radiation: Guidance for occupational physicians

    International Nuclear Information System (INIS)

    1998-01-01

    This Safety Report is intended mainly for occupational physicians, as well as for occupational health service personnel, to assist them in routine practice by specifying the features of work under radiation conditions, the general rules of radiological protection for occupational exposure and the organization of the medical surveillance of workers occupationally exposed to radiation. The Report is consistent with the recommendations of the International Commission on Radiological Protection presented in its Publication 60 (1990) and with the International Basic Safety Standards for Protection against Ionizing Radiation and for the Safety of Radiation Sources published by the IAEA in 1966. It supersedes Safety Series No.83 (Radiation Protection in Occupational Health: Manual for Occupational Physicians) published by the IAEA in 1987

  2. Medical status of Marshallese accidentally exposed to 1954 Bravo fallout radiation: January 1988 through December 1991

    Energy Technology Data Exchange (ETDEWEB)

    Howard, J.E.; Heotis, P.M.; Scott, W.A.; Adams, W.H.

    1995-07-01

    The purpose of this report is to disseminate information concerning the medical status of 253 Marshallese exposed to fallout radiation in 1954. This report discusses the medical care provided and the medical findings for the years 1988-1991. Details of the BRAVO thermonuclear accident that caused the exposure have been published, and a 1955 article in the Journal of the American Medical Association describing the acute medical effects in the exposed population remains a definitive and relevant description of events. Participation in the Marshall Islands Medical Program by the exposed Marshallese is voluntary. In the spring and fall of each year, medical surveillance is provided to exposed and unexposed cohorts. Examinations performed include: a cancer-related examination as defined by the American Society, an annual thyroid examination and thyroid function testing, serum prolactin testing looking for pituitary tumors, annual blood counts to include platelets, and evaluation for paraneoplastic evidence of neoplasms. This report details the medical program, medical findings, and thyroid surgery findings. Deaths (4 exposed and 10 nonexposed) that occurred during the reporting period are discussed. There is a mild but relatively consistent depression of neutrophil, lymphocyte, and platelet concentrations in the blood of the exposed population. This depression appears to be of no clinical significance. Thyroid hypofunction, either clinical or biochemical, has been documented as a consequence of radiation exposure in 14 exposed individuals. Previously, one other exposed person was diagnosed with basal cell carcinoma. During this reporting period, a thyroid nodule was identified in an individual who was in utero during the exposure. Upon pathologic review, the nodule was diagnosed as occult papillary carcinoma.

  3. Medical status of Marshallese accidentally exposed to 1954 Bravo fallout radiation: January 1988 through December 1991

    International Nuclear Information System (INIS)

    Howard, J.E.; Heotis, P.M.; Scott, W.A.; Adams, W.H.

    1995-07-01

    The purpose of this report is to disseminate information concerning the medical status of 253 Marshallese exposed to fallout radiation in 1954. This report discusses the medical care provided and the medical findings for the years 1988-1991. Details of the BRAVO thermonuclear accident that caused the exposure have been published, and a 1955 article in the Journal of the American Medical Association describing the acute medical effects in the exposed population remains a definitive and relevant description of events. Participation in the Marshall Islands Medical Program by the exposed Marshallese is voluntary. In the spring and fall of each year, medical surveillance is provided to exposed and unexposed cohorts. Examinations performed include: a cancer-related examination as defined by the American Society, an annual thyroid examination and thyroid function testing, serum prolactin testing looking for pituitary tumors, annual blood counts to include platelets, and evaluation for paraneoplastic evidence of neoplasms. This report details the medical program, medical findings, and thyroid surgery findings. Deaths (4 exposed and 10 nonexposed) that occurred during the reporting period are discussed. There is a mild but relatively consistent depression of neutrophil, lymphocyte, and platelet concentrations in the blood of the exposed population. This depression appears to be of no clinical significance. Thyroid hypofunction, either clinical or biochemical, has been documented as a consequence of radiation exposure in 14 exposed individuals. Previously, one other exposed person was diagnosed with basal cell carcinoma. During this reporting period, a thyroid nodule was identified in an individual who was in utero during the exposure. Upon pathologic review, the nodule was diagnosed as occult papillary carcinoma

  4. Retrospective genetic study of germinative mutations in Str loci of individuals potentially exposed to ionizing radiation

    International Nuclear Information System (INIS)

    Costa, Emilia Oliveira Alves

    2010-01-01

    The Brazilian radiological accident that occurred in 1987, in Goiania, it was a terrible radiation episode. As a consequence, hundreds of people were contaminated due to the Cesium-137 radiation. Recently, many studies had shown that genome instabilities, such as, mutations, chromosomal aberrations, micronuclei formation and micro satellite instability and a delay on cellular death are usually reported on mammal cells exposed to ionizing radiation, being considered as a manly risk to humans. Mutations can be spontaneous, and the occurrence is dependent on the organism, or, induced, being associated to mutagenic exposition. Ionizing radiations are an example of physical and mutagenic agents that could harm the cell repair and could cause the development of many types of cancer. The evaluation of the biological effects of the ionizing radiation, in somatic and germ line cells, with a consequent determination of the radio-induced mutations, it is extremely important to estimate the genetic risks, manly in population exposed to radiation. The analyses of repetitive DNA sequences have been demonstrated that such sequences are prone to high rates of spontaneous mutations. The minisatellites and microsatellites have been used to demonstrate the induction of germ line mutation rates on mouse, humans, among others organisms. The aim of the present study was to analyze the frequency of microsatellite alterations to determine the mutation rates occurred in germ cells of the parents exposed to the ionizing radiation of the Cesium-137. The studied group was constitute of 10 families of individuals accidentally exposed to Cesium-137 and by the control group constituted by 645 healthy individuals who carried out paternity tests on 2009. We found only one mutation of paternal origin in the D8S1179 locus on the exposed group, being the mutation rate of 0.002. In the control group, we found 01 mutation on D16S539 loei and on D3S1358; 02 mutations on Penta E loeus; 04 mutations on D

  5. Germline mutations in people descendants occupationally exposed to ionizing radiation from Cesium 137

    International Nuclear Information System (INIS)

    Silva, Juliana Ferreira da

    2016-01-01

    The radiological accident in Goiania in 1987, resulted in a serious episode of human contamination, animal, plant and environmental were exposed to Cesium 137 chloride ( 137 CsCl) that caused contamination and accidental and occupational exposure to ionizing radiation. Ionizing radiation is one of the environmental components that causes most cellular stress in complex organisms. Exposure to ionizing radiation induces breaks in nucleic acids, especially, DNA double and single strand breaks. Chromosomal microarray analysis is an important tool for the detection and microdeletion and microduplications in the genomes. In this study we proposed to analyze the effect of exposure to RI on the formation of CNVs in an exposed human population occupationally to ionizing radiation from Cesium 137 during the accident in Goiania. The exposed group consisted of 07 families, of which at least one parent was occupationally exposed to ionizing radiation from Cesium 137, including a total of 25 individuals, do not know the absorbed dose of the military who were occupationally exposed to ionizing radiation. 11 families with a group of individuals not exposed to IR was used as control were used including a total of 33 individuals with no history of exposure to RI. The genotyping microarray was conducted in CytoScan HD system (Affymetrix®) without then analyzes was performed in ChAS® software. The statistical tests used were: Shapiro-Wilk, Mann- Whitney U, Spearman correlation, discriminant function analysis, binomial test, χ 2 test. All analyzes were performed using the statistical package SPSS 21.0, with a significance level of 5% (p <0.05). The frequency of CNVs were estimated loss / generation, gain / generation and burden / generation, representing 3,9 x 10 -5 , 6,8 x 10 -6 and 4,6 x 10 -5 respectively for the exposed group. For the control group, the frequencies were 2,1 x 10 -5 , 5,9 x 10 -6 and 3,1 x 10 -5 respectively. Thus, the frequency of CNVs showed statistically

  6. Methods and technologies for creation of register for exposed to radiation population

    International Nuclear Information System (INIS)

    Apsalikov, K.; Madieva, M.; Gusev, B.; Chajzunusova, N.; Isadilova, M.; Bejsenova, Sh.; Argembaeva, R.

    2005-01-01

    For the last 60 years, some huge radioecological accidents and catastrophes have taken place, connected with nuclear weapon use in war, nuclear weapon tests on the nuclear test sites of Nevada, Semipalatinsk, Loob-Nor and the disturbance of the technological cycle at the enterprises of atomic industry and NPP. The scientific-technical program is being carried out at the Scientific research Institute of Radiation medicine and Ecology. The one of the its major task is to create the Scientific Automated Medical Register for the Kazakhstan population exposed to radiation. The aim of this program is a long-term automated personnel registering of population exposed to radiation in consequences of on nuclear testing on the Semipalatinsk Test Site, evolution of health condition and its changes, prediction for taken optimal decisions upon minimization of post-radiation consequences. Thus, main tendencies of Register creation are registration of the extent and characteristics of concrete man-caused factor (including radioactive), the number and age-sexual peculiarities of the risk group, medical information according to qualitative and quantitative parameters of different nosological forms of radiation induced diseases, and the duration of stay of definite patient under risk. After formatting of effective equivalent doses the information allows not only containing radiation risk, but also working out medical-social activities, directed to decrease the risk up to the level of average Republican standards. (author)

  7. ATLAS Transition Radiation Tracker - small piece

    CERN Multimedia

    2006-01-01

    The ATLAS transition radiation tracker is made of 300'000 straw tubes, up to 144cm long. Filled with a gas mixture and threaded with a wire, each straw is a complete mini-detector in its own right. An electric field is applied between the wire and the outside wall of the straw. As particles pass through, they collide with atoms in the gas, knocking out electrons. The avalanche of electrons is detected as an electrical signal on the wire in the centre. The tracker plays two important roles. Firstly, it makes more position measurements, giving more dots for the computers to join up to recreate the particle tracks. Also, together with the ATLAS calorimeters, it distinguishes between different types of particles depending on whether they emit radiation as they make the transition from the surrounding foil into the straws.

  8. Association of radiation dose with prevalence of thyroid nodules among atomic bomb survivors exposed in childhood (2007-2011).

    Science.gov (United States)

    Imaizumi, Misa; Ohishi, Waka; Nakashima, Eiji; Sera, Nobuko; Neriishi, Kazuo; Yamada, Michiko; Tatsukawa, Yoshimi; Takahashi, Ikuno; Fujiwara, Saeko; Sugino, Keizo; Ando, Takao; Usa, Toshiro; Kawakami, Atsushi; Akahoshi, Masazumi; Hida, Ayumi

    2015-02-01

    Few studies have evaluated the association of radiation dose with thyroid nodules among adults exposed to radiation in childhood. To evaluate radiation dose responses on the prevalence of thyroid nodules in atomic bomb survivors exposed in childhood. This survey study investigated 3087 Hiroshima and Nagasaki atomic bomb survivors who were younger than 10 years at exposure and participated in the thyroid study of the Adult Health Study at the Radiation Effects Research Foundation. Thyroid examinations including thyroid ultrasonography were conducted between October 2007 and October 2011, and solid nodules underwent fine-needle aspiration biopsy. Data from 2668 participants (86.4% of the total participants; mean age, 68.2 years; 1213 men; and 1455 women) with known atomic bomb thyroid radiation doses (mean dose, 0.182 Gy; median dose, 0.018 Gy; dose range, 0-4.040 Gy) were analyzed. The prevalence of all thyroid nodules having a diameter of 10 mm or more (consisting of solid nodules [malignant and benign] and cysts), prevalence of small thyroid nodules that were less than 10 mm in diameter detected by ultrasonography, and atomic bomb radiation dose-responses. Thyroid nodules with a diameter of 10 mm or more were identified in 470 participants (17.6%): solid nodules (427 cases [16.0%]), malignant tumors (47 cases [1.8%]), benign nodules (186 cases [7.0%]), and cysts (49 cases [1.8%]), and all were significantly associated with thyroid radiation dose. Excess odds ratios per gray unit were 1.65 (95% CI, 0.89-2.64) for all nodules, 1.72 (95% CI, 0.93-2.75) for solid nodules, 4.40 (95% CI, 1.75-9.97) for malignant tumors, 2.07 (95% CI, 1.16-3.39) for benign nodules, and 1.11 (95% CI, 0.15-3.12) for cysts. The interaction between age at exposure and the dose was significant for the prevalence of all nodules (P = .003) and solid nodules (P bomb survivors 62 to 66 years after their exposure in childhood. However, radiation exposure is not associated with small thyroid

  9. Occupational exposure to solar radiation in Australia: who is exposed and what protection do they use?

    Science.gov (United States)

    Carey, Renee N; Glass, Deborah C; Peters, Susan; Reid, Alison; Benke, Geza; Driscoll, Timothy R; Fritschi, Lin

    2014-02-01

    Solar ultraviolet radiation (UVR) exposure is widely recognised as a leading cause of skin cancer, with outdoor workers being particularly at risk. Little is known on a national level about how many workers are exposed to solar radiation, the circumstances in which they are exposed, or their use of protective measures. The Australian Work Exposures Study (AWES) was a cross-sectional telephone survey of 5,023 Australian workers aged 18 to 65. A subset of 1,113 respondents who indicated they worked outdoors was asked about their exposure to solar radiation in terms of the amount of time they spent working outdoors, their working location and their use of sun protective measures. A total of 1,100 respondents (22% overall) were assessed as being exposed to solar radiation at work. Exposure was more likely among males and those residing in lower socioeconomic and regional areas. Sun protection was used by 95% of the respondents, although the level of protection varied among workers, with only 8.7% classified as fully protected. This study provides valuable information regarding solar exposure that has not previously been available. The results of this study will inform strategies for risk reduction. © 2014 The Authors. ANZJPH © 2014 Public Health Association of Australia.

  10. A cytogenetic approach to the effects of low levels of ionizing radiations on occupationally exposed individuals

    Energy Technology Data Exchange (ETDEWEB)

    Zakeri, Farideh [National Radiation Protection Department, Iranian Nuclear Regulatory Authority, Nuclear Science and Research Institute-Agriculture, Medicine and Industry Research School, Tehran (Iran, Islamic Republic of); Graduate School of Science and Technology, Chiba University, Inage-ku, Chiba 263-8522 (Japan)], E-mail: fzakeri@aeoi.org.ir; Hirobe, Tomohisa [Graduate School of Science and Technology, Chiba University, Inage-ku, Chiba 263-8522 (Japan); Radiation Effect Mechanism Research Group, National Institute of Radiological Sciences, Inage-ku, Chiba 263-8555 (Japan)

    2010-01-15

    The aim of the present study was to assess occupationally induced chromosomal damage in hospital workers exposed to low levels of ionizing radiation. Thirty-two interventional cardiologists, 36 nuclear medicine physicians and 33 conventional radiologists were included in this study, along with 35 healthy age- and sex-matched individuals as the control group. We used conventional metaphase chromosome aberration (CA) analysis, cytokinesis-block micronucleus (MN) assay as important biological indicators of ionizing radiation exposure. Occupational dosimetry records were collected over the last year (ranged from 0.25 to 48 mSv) and their whole life exposure (ranged from 1.5 to 147 mSv). The results showed significantly higher frequencies of dicentric and acentric CAs (p < 0.001) and MN (p < 0.01) in all exposed groups than in the controls. Taking all the confounding factors into account, no obvious trend of increased chromosomal damages as a function of either duration of employment, exposed dose, sex or age was observed. Interventional cardiologists had the highest rates of CA and MN frequencies between the worker groups, though the differences were not significant. These results indicate that long term exposure to low dose ionizing radiation could result in DNA damage. Hence, the personnel who work in the hospitals should carefully apply the radiation protection procedures.

  11. Dynamics of extra-genital pathology formation in exposed to radiation women of the reproductive age

    International Nuclear Information System (INIS)

    Apsalikov, K.N.; Gusev, B.I.; Pivina, L.M.; Kenzhina, L.B.; Ryzhenkova, O.N.; Mansarina, A.E.; Bajbusinov, O.N.

    2005-01-01

    The paper presents an extra-genital sickness rate analysis in exposed women of reproductive age that live on territories adjacent to the Semipalatinsk test site, for the period from 1963 to 2000. The average dose of women exposed to radiation is more than 0.5 Sv. Significant exceeding of age-specific standardized factor for the period from 1963 to 1990 was found. Among nosologic classes, representing exceeding of age-specific standardized factors in women of reproductive age, there were revealed diseases of blood circulation system, blood and hematopoietic organs, endocrine system, nervous system and sense organs. (author)

  12. Expression profile of cell cycle genes in the fish CATLA CATLA (Ham.) exposed to gamma radiation

    International Nuclear Information System (INIS)

    Anbumani, S.; Mohankumar Mary, N.

    2012-01-01

    The International Commission on Radiological Protection (ICRP) emphasized the need to protect non-human biota from the potential effects of ionizing radiation and proposed to include molecular effects such as DNA damage as endpoints. Molecular effects of ionizing radiation exposure in representative non-humans are largely unexplored and sufficient data is not available in fishes. Gene expression is a fast and sensitive end point in detecting the molecular cues as a result of ionizing radiation exposure in a wide variety of aquatic organisms under suspected environmental contamination. Exposure to ionizing radiation transiently alters gene expression profiles as cells regulate certain genes to protect cellular structures and repair damage. The present study focused on genes like Gadd45á, Cdk1 and Bcl-2 in DNA damage repair and cell cycle machinery and its implication as molecular markers of radiation exposure. This study is first of its kind showing the in vivo expression profile of cell cycle genes in fish exposed to gamma radiation. Although this preliminary investigation points to certain molecular markers of ionizing radiation, elaborate studies with various doses and dose-rates are required before these markers find application as prospective molecular markers in aquatic radiation biodosimetry

  13. Development of defects in the structure of PIN dosimetry diodes exposed to gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Sopko, V. [Hospital Na Bulovce, Department of Radiological Physics, Budinova 2, CZ-18081 Prague 8 (Czech Republic); Institute of Experimental and Applied Physics, Czech Technical University in Prague, Horska 3a/22, CZ 12800 Prague 2 (Czech Republic); Sopko, B., E-mail: bruno.sopko@cern.ch [Department of Physics, Faculty of Mechanical Engineering, Czech Technical University in Prague, Technicka 4, CZ 16000 Prague 6 (Czech Republic); Faculty of Production Technology and Management, J. E. Purkyně Univerzity in Ústí nad Labem, Na Okraji 1001, 400 01 Ústí nad Labem (Czech Republic); Chren, D. [Department of Physics, Faculty of Mechanical Engineering, Czech Technical University in Prague, Technicka 4, CZ 16000 Prague 6 (Czech Republic); Dammer, J. [Hospital Na Bulovce, Department of Radiological Physics, Budinova 2, CZ-18081 Prague 8 (Czech Republic); Institute of Experimental and Applied Physics, Czech Technical University in Prague, Horska 3a/22, CZ 12800 Prague 2 (Czech Republic); Charles University in Prague, First Faculty of Medicine, Salmovská 1,CZ-12000 Prague 2 (Czech Republic)

    2013-12-01

    Studies of radiation induced defects continue to be relevant as they find an ever greater application due to the increasing radiation doses to which semiconductor detectors are exposed. Efforts of figuring out the changes due to high radiation doses provide the fundamental motivation for this type of experiments. The PIN diode is described, and a developmental disorder caused thereto by 60Co source gamma quanta ranging from 100 kGy to 1 MGy. The calibration curve shows the effect of disturbances on the volt-ampere characteristics as a function of the dose of gamma radiation. The results are compared with earlier published data. Highlights: •We have studied Si PIN diode dosimeters irradiated by gamma. •We measured DLTS spectra and calculated energy traps caused by gamma irradiation. •Increasing dose caused creation of new traps and disappearance of others.

  14. Report on results of seventeen years in consultations of radiation exposed pregnant women

    International Nuclear Information System (INIS)

    Bruening, L.; Arndt, D.; Laude, G.

    1992-01-01

    In a survey it will be given results of consultations of pregnant women exposed during the pregnancy in the period of 1976 to 1992 formerly in the National Board of Atomic Safety and Radiation Protection of the GDR and since 1990 in the Clinic-diagnostical Division of the Federal Health Office. The report includes dose estimations of the embryo and medical assessments of 430 pregnant women. The radiation exposure were mainly received by X-ray diagnostic (n = 406 cases) and the others by applications of radiation in nuclear medicine, research and vocational training (n = 24 cases). Results of dose and risk estimation were summarized in tables. Women having incurred fetal doses in excess of 100 mGy were recommended to interrupt pregnancy. A fetal dose above 100 mGy occured in 9 cases. The anatomico-pathological and embryological findings of the embryo or fetus showed only in one case a reference of teratogenic radiation damage. (orig.) [de

  15. BRCA mutations in women from Belarus exposed to radiation from Chernobyl compared to controls

    International Nuclear Information System (INIS)

    Melnov, S.B.; Nadyrov, E.; Modugno, F.; Foley, T.; Murphy, P.; Putyrski, L.

    2009-01-01

    Full text: There are several reports of studies that suggest a causal association between exposure to ionizing radiation and the subsequent development of breast cancer. Since the Chernobyl accident in 1986, there has been a dramatic increase in thyroid cancer after radiation exposure, especially among those who were exposed as young children and living in the areas with the greatest contamination. One early report found that women exposed to radiation from Chernobyl had a slight, but significant increase in the incidence of breast cancer. No other data are reported about additional risks for the development of breast cancer in this population. With funding from a NIH R03 grant application and the Child Health International Foundation, we are investigating the molecular epidemiology of breast cancer in Belarusian women exposed at ages < 40 years to high radiation doses from the Chernobyl accident compared to controls for the common Eastern European BRCA 1/2 mutations. As occurred 20+ years after exposure of Japanese women exposed to radiation fallout from atomic bombs in 1945, we expect to find a sustained increase in breast cancer for the coming decade and longer. We accomplished nearly all of the following objectives in the evaluation of Belarusian women with breast cancer and controls who were exposed to sustained high doses of ionizing radiation in 1986. When our US collaborators visited the Republic of Belarus, they (a) met with Belarusian consultants, co-investigators, other health care professionals and administrators and developed a formal collaboration to study breast cancer, BRCA mutations and radiation exposure; (b) recruited Belarusian cancer epidemiologists, Chernobyl radiation dosimetrists, and cancer registry/database management personnel; (c) began a collaboration with the Director of Breast Cancer Surgery for the Republic of Belarus and met several breast cancer specialists in surgery and oncology under his direction; and (d) met medical directors

  16. [Cognitive impairments in persons exposed to radiation during the period of prenatal development].

    Science.gov (United States)

    Burtovaya, E Yu; Kantina, T E; Belova, M V; Akleyev, A V

    2015-01-01

    To assess the cognitive status in persons exposed to ionizing radiation in prenatal period. The study included in-utero exposed people (n = 77), and the comparison group (n = 73), which consisted of people who lived in the territories of the Chelyabinsk Oblast that were not radioactive. The following methods were used: clinical, clinical-psychological (Mini-Mental State Examination (MMSE), the WAIS test, the proverb interpretation task, neurophysiological (EEG) methods, laboratory-based methods (cholesterol, high and low-density lipoproteins, triglycerides, cortisol, melatonin), and methods of statistical data processing. The number of people with non-psychotic mental disorders with the prevalence of organic mental disorders (cognitive and asthenic) was significantly higher among in-utero exposed subjects. A neurophysiological study revealed more severe changes in the bioelectric brain activity with the presence of pathological and theta-rhythms in exposed persons. The clinical-psychological study revealed a significant decrease in the analytic/synthetic ability in exposed people and significantly lower level of the general and verbal IQ. These changes were accompanied by higher levels of cortisol and melatonin which led to the activation and tension of the adaptation mechanisms in in-utero exposed subjects.

  17. Sperm quality and DNA damage in men from Jilin Province, China, who are occupationally exposed to ionizing radiation.

    Science.gov (United States)

    Zhou, D D; Hao, J L; Guo, K M; Lu, C W; Liu, X D

    2016-03-22

    Long-term radiation exposure affects human health. Ionizing radiation has long been known to raise the risk of cancer. In addition to high doses of radiation, low-dose ionizing radiation might increase the risk of cardiovascular disease, lens opacity, and some other non-cancerous diseases. Low- and high-dose exposures to ionizing radiation elicit different signaling events at the molecular level, and may involve different response mechanisms. The health risks arising from exposure to low doses of ionizing radiation should be re-evaluated. Health workers exposed to ionizing radiation experience low-dose radiation and have an increased risk of hematological malignancies. Reproductive function is sensitive to changes in the physical environment, including ionizing radiation. However, data is scarce regarding the association between occupational radiation exposure and risk to human fertility. Sperm DNA integrity is a functional parameter of male fertility evaluation. Hence, we aimed to report sperm quality and DNA damage in men from Jilin Province, China, who were occupationally exposed to ionizing radiation. Sperm motility and normal morphology were significantly lower in the exposed compared with the non-exposed men. There was no statistically significant difference in sperm concentration between exposed and non-exposed men. The sperm DNA fragmentation index was significantly higher in the exposed than the non-exposed men. Chronic long-term exposure to low doses of ionizing radiation could affect sperm motility, normal morphology, and the sperm DNA fragmentation index in the Chinese population. Sperm quality and DNA integrity are functional parameters that could be used to evaluate occupational exposure to ionizing radiation.

  18. Behavior and memory evaluation of Wistar rats exposed to 1·8 GHz radiofrequency electromagnetic radiation.

    Science.gov (United States)

    Júnior, Luiz Carlos de Caires; Guimarães, Ernesto da Silveira Goulart; Musso, Camila Manso; Stabler, Collin Turner; Garcia, Raúl Marcel González; Mourão-Júnior, Carlos Alberto; Andreazzi, Ana Eliza

    2014-09-01

    The development of communication systems has brought great social and economic benefits to society. As mobile phone use has become widespread, concerns have emerged regarding the potential adverse effects of radiofrequency electromagnetic radiation (RF-EMR) used by these devices. To verify potential effects of mobile phone radiation on the central nervous system (CNS) in an animal model. Male Wistar rats (60 days old) were exposed to RF-EMR from a Global System for Mobile (GSM) cell phone (1·8 GHz) for 3 days. At the end of the exposure, the following behavioral tests were performed: open field and object recognition. Our results showed that exposed animals did not present anxiety patterns or working memory impairment, but stress behavior actions were observed. Given the results of the present study, we speculate that RF-EMR does not promote CNS impairment, but suggest that it may lead to stressful behavioral patterns.

  19. The health status of grandchildren of subjects occupationally exposed to chronic radiation. Communication 2. Morphofunctional parameters

    International Nuclear Information System (INIS)

    Petrushkina, N.P.; Musatkova, O.B.

    1996-01-01

    The study was aimed at investigation of the parameters of physical development and specific features in the development of psychomotor habits and peripheral blood parameters in children aged 0 to 7 grandchildren of exposed individuals. A dynamic follow-up of physical and psychomotor development, as well as regular check-ups of peripheral blood were carried out in 877 grandchildren of test subjects occupationally exposed to chronic radiation before conception. Multifactorial analysis did not show a correlation between the deviations in the physical development of children in the studied cohort and exposure of their grandparents and/or parents. Factors other than radiation (poor health status of mother, gestosis) did influence the studied parameters. The mean levels of hemoglobin, red cells, platelets, and leukocytes in the test group were virtually the same as in controls and coincided with published data [ru

  20. Neonates are Over Exposed to X-Ray Radiation During Their Stay in NICUs

    International Nuclear Information System (INIS)

    Datz, H.; Margaliot, M.; Ben-Shlemo, A.; Shani, G.; Bader, D.; Uster, A.; Marks, K.; Solomkin, T.; Zangen, D.; Sadetzki, S.

    2004-01-01

    Diagnostic radiology plays an important role in the assessment and treatment of neonates requiring intensive care. It is often necessary to perform multiple radiographic examinations depending upon the infants birth weight, gestational age and respiratory problems, especially to those infants with very low birth weight (< 1500g). The high frequency of these examinations raises the radiological issue due to the potentially long-term adverse effects. We hypothesize that unnecessary organs of those infants are exposed to X-ray radiation during their hospitalization, leading to an increased risk of long-term adverse effects. The goal of this study was to examine if organs, other than those originally intended, were exposed to excessive radiation in a population of neonates during their stay in the Neonatal Intensive Care Unit - NICU

  1. Surgical management of radiation injury to the small intestine

    Energy Technology Data Exchange (ETDEWEB)

    Swan, R.W.; Fowler, W.C. Jr., Boronow, R.C.

    1976-01-01

    Severe injury of the small intestine represents one of the most tragic complications of radiation of the pelvis and abdomen. Not uncommonly, patients die from the radiation or the treatment of its intestinal complications. More commonly, patients become intestinal cripples, secondary to chronic partial obstruction of the small intestine and malnutrition associated with the stagnant loop syndrome, as previously reported by one of us. Management results have been discouraging, usually because of a general lack of clinical recognition and understanding of radiation injury to the intestine. Medical management has not been satisfactory. It may provide temporary relief from symptoms, but not long-lasting. Surgical management, although frequently curative, has been associated with high death and morbidity rates. Many surgical procedures have been used in treating radiation injury to the small intestine. Generally, these fall into two categories: first, intestinal resection with primary anastomosis; and second, enteroenteric or enterocolic bypass. In the literature are reflected advocates for each method of surgical management.

  2. Clinical course of brain stroke in the persons exposed to ionizing radiation under the production conditions

    Energy Technology Data Exchange (ETDEWEB)

    Bouchmanov, A. [State Research Center of Russia, Moscow (Russian Federation). Inst. of Biophysics

    2000-05-01

    The purpose was to study the risk factors and clinical course of brain strokes in professionally exposed workers being employed in plutonium production in comparison with a control group. The method and materials of study -clinical supervision and clinical database creation on 162 cases of brain stroke (128 males and 34 females) developed among professionally exposed workers. Age of patient varied from 21 to 68 years (in average -51.6 y.). The control group consisted of patients with the same diagnosis, worked on the same enterprise, but non-exposed to radiation. Data on the totally accumulated dose of external gamma radiation were received on the base of the individual dosimeters (from 0.1 cSv to 52 cSv, in average about 13 cSv); the plutonium-239 body content was estimated accordingly to the level of urine radionuclide excretion (from 0.4 kBq to 1.6 kBq, in average about 0.33 kBq). Muscle's hypertinsion and pathological great-toe reflexes in paretic legs and hands, hemianopsia, impressive and ataxic aphasia prevailed in the patients with ischemic brain strokes in system of internal carotid artery, exposed to radiation. The changes of muscle's tension, ataxia and nystagmus were marked more often in the professionals with ischemic brain strokes in system of vertebrobasilar artery. The illness proceeded more easy and with smaller frequency of frustration of consciousness and algesthesia, irrespective of a type ischemic brain strokes in the people exposed to ionizing radiation, than in patients of non-irradiated group. It was found that the arterial hypertension appeared to be the main risk factor for the brain stroke in both groups of patients (in 81.48% and 91.15% of cases). There was no marked differences in significance of risk factors and in main clinical parameters of various types of ischemic brain strokes among the patients professionally exposed to radiation in comparison with a control group. (author)

  3. [Genotoxic damage among artisanal and small-scale mining workers exposed to mercury].

    Science.gov (United States)

    Rosales-Rimache, Jaime A; Elizabeth Malca, Nancy; Alarcón, Jhonatan J; Chávez, Manuel; Gonzáles, Marco Antonio

    2013-01-01

    To determine the genotoxic damage among artisanal and small-scale mining workers exposed to mercury. Observational cross-sectional study which evaluated mercury-exposed workers (n=83), whose cells were collected by mouth swab for further staining, microscopic observance, micronuclei count, and other nuclear alterations. 24-hour urine was also collected for the determination of inorganic mercury. 68.7% of participants were male, the mean age being 43 ± 12,4 years (range: 16-76). The average time of occupational exposure to mercury was 12,1 ± 6,7 years, and the contact with mercury was 4,1 ± 3,6 kg per person per day. 93% of participants failed to wear personal protection gear while handling mercury. Results of biological monitoring showed that 17% of participants had concentrations of mercury in urine higher than 2,5 µg/L, this value being the detection limit of the measurement technique used. Results of the genotoxic evaluation evidenced that 15% of people with labor exposure to mercury presented micronuclei in mouth epithelial cells, and other indicators of nuclear alteration such as nucleoplasmic bridges, gemmation and binucleation were found, which are also considered genotoxic events associated to the exposure of physical or chemical risk agents. The finding of micronuclei in mouth epithelial cells reflects genotoxic damage associated to the labor exposure of mercury used in artisanal and small-scale mining activities.

  4. Temperature thresholds for surface blistering of platinum and stainless steel exposed to curium-242 alpha radiations

    International Nuclear Information System (INIS)

    McDonell, W.R.; Dillich, S.

    1981-01-01

    Implantation of helium in materials exposed to alpha-emitting radionuclides such as 242 Cm causes surface blistering at elevated temperatures. The temperature thresholds for such blistering are of practical importance to the selection of suitable container materials for radionuclides, and are of fundamental interest with regard to the mechanisms of helium blistering of materials in radiation environments. The purpose of this investigation was to establish temperature thresholds for surface blistering of platinum and stainless-steel container materials by post-irradiation heating of specimens exposed at room temperature to alpha particles from an external 242 Cm source. These thresholds were compared with (1) the analogous temperature thresholds for surface blistering of materials exposed to external beams of accelerator helium ions, and (2) thresholds for swelling and grain-boundary cracking of materials in which helium is generated internally by (n,α) reactions during reactor exposures

  5. Health status of grandchildren of subjects occupationally exposed to chronic radiation. Communication 4. Congenital developmental defects

    International Nuclear Information System (INIS)

    Petrushkina, N.P.; Musatkova, O.B.

    1996-01-01

    The purpose of this study was to analyze the incidence and structure of cogenital developmental defects in the grandchildren of subjects occupationally exposed to chronic external gamma-irradiation. For 830 children only grandfather was exposed, for 259 only grandmother, and for 468 grandfather and grandmother. The mean equivalent doses for gonads by the moment of conception of future parents of the cohort examined ranged from 17.3 to 145.3 sSv. The incidence and structure of congenital developmental defects in 1557 grandchildren of occupationally exposed subjects differed from that in controls. Multifactorial analysis failed to establish the effect of grandparents' and parents' exposure on the development of diseases in the progeny. Factors other than radiation proved to be significant. 13 refs.; 1 tab

  6. Surveillance of health care workers exposed to ionising radiation: Rimed pilot study

    International Nuclear Information System (INIS)

    2008-01-01

    The project so-called RIMED aimed to set up epidemiological surveillance of health care workers exposed to ionizing radiation. A pilot study was conducted in a sample of hospital personnel to examine the possibility of identifying exposed subjects in order to analyse mortality patterns according to occupational characteristics such as medical departments or occupations in a historical cohort. Seven hospitals participated in this pilot study. Health-care workers who had worn a dosimeter up to December 2003 were to be included in this cohort. The subjects' identification data were obtained from the SISERI (Systeme d'information de la surveillance de l'exposition aux rayonnements ionisants - Ionizing Radiation Exposure Monitoring Information System) database managed by the Institut de radioprotection et de surete nucleaire - Radiation Protection and Nuclear Safety Institute (IRSN). The SISERI system was in a 'pilot' phase in 2004. According to SISERI database, a total of 5126 subjects were found to have worn a dosimeter up to December 2003. The subjects' identification data were completed by the administrative services of the hospitals and occupational physicians searched for subjects' occupational data. Information required for the vital status search was satisfactorily completed only for 38% of the cohort subjects. This pilot study showed that obtaining data from SISERI database completed by hospital administrative data in 2004 led to a database of insufficient quality for epidemiological surveillance. The Institut de veille sanitaire (French Institute of Public Health Surveillance) recommends that transmission by the employers of some specific personal or occupational data of the exposed subjects should be made compulsory. In this way, SISERI system should be able to constitute any database with required quality for epidemiological surveillance of ionizing radiation exposed subjects. (authors)

  7. Carcinogenic risk for workers exposed to ionizing radiation. A critical review of present epidemiologic studies

    International Nuclear Information System (INIS)

    Tirmarche, M.

    1987-01-01

    Epidemiologic studies on workers who have been exposed to ionizing radiation have allowed to demonstrate certain cancer risks associated with elevated, often retrospectively reconstituted exposures. Present studies on still active workers or workers having worked for the last 15 years are indispensable to define the risk associated with low irradiation doses; they must, however, take into account confounding factors that may play a role in the etiology of the cancer studied

  8. Reproductive function of animals exposed to low-dose external γ-radiation

    International Nuclear Information System (INIS)

    Izhevskij, P.V.; Krupitskaya, L.I.; Startsev, N.V.

    1993-01-01

    Chronic external γ-radiation effects on the reproductive function were simulated in male rats at doses equivalent to the dose obtained by the persons who participated in the liquidation of the Chernobyl poer plant accident aftereffects and by the population. The incidence of the pre-and postimplantation deaths was found increased in the progeny of males exposed to chronic external γ-irradiation at total doses of 158 and 237 Gy, though no strict dose dependence was observed

  9. The health after effects on children exposed to Chernobyl radiation fallout

    International Nuclear Information System (INIS)

    Contis, G.

    2002-01-01

    The purpose of this paper is to describe some of the long-term health consequences that are now being detected in Ukrainian adolescents who, as children, were exposed to Chornobyl radiation fallout fifteen years ago. The information presented will emphasize the importance of ensuring that nuclear power plants are built and operated with all the safeguards needed to prevent a recurrence of the Chornobyl disaster

  10. Germline minisatellite mutations in workers occupationally exposed to radiation at the Sellafield nuclear facility

    International Nuclear Information System (INIS)

    Tawn, E Janet; Curwen, Gillian B; Rees, Gwen S; Jonas, Patricia

    2015-01-01

    Germline minisatellite mutation rates were investigated in male workers occupationally exposed to radiation at the Sellafield nuclear facility. DNA samples from 160 families with 255 offspring were analysed for mutations at eight hypervariable minisatellite loci (B6.7, CEB1, CEB15, CEB25, CEB36, MS1, MS31, MS32) by Southern hybridisation. No significant difference was observed between the paternal mutation rate of 5.0% (37 mutations in 736 alleles) for control fathers with a mean preconceptional testicular dose of 9 mSv and that of 5.8% (66 in 1137 alleles) for exposed fathers with a mean preconceptional testicular dose of 194 mSv. Subgrouping the exposed fathers into two dose groups with means of 111 mSv and 274 mSv revealed paternal mutation rates of 6.0% (32 mutations in 536 alleles) and 5.7% (34 mutations in 601 alleles), respectively, neither of which was significantly different in comparisons with the rate for the control fathers. Maternal mutation rates of 1.6% (12 mutations in 742 alleles) for the partners of control fathers and 1.7% (19 mutations in 1133 alleles) for partners of exposed fathers were not significantly different. This study provides evidence that paternal preconceptional occupational radiation exposure does not increase the germline minisatellite mutation rate and therefore refutes suggestions that such exposure could result in a destabilisation of the germline that can be passed on to future generations. (paper)

  11. Scientific colloquium on medical supervision of workers exposed to ionizing and non ionizing radiations

    International Nuclear Information System (INIS)

    1975-01-01

    The general principles of medical surveillance for workers exposed to ionizing radiation were defined in the Euratom Basic Standards in 1959. These principles, which are in accordance with the early IGRP publications, have been adopted by the national authorities and implemented without difficulty. However, because of the forthcoming publication of the revised Basic Standards- in accordance with recent IGRP recommendations, the Commission decided to organize a meeting of doctors responsible for the medical surveillance of workers exposed to ionizing radiation in order to disseminate as widely as possible the results of experience gained in the field of radiological protection and to pinpoint the practical difficulties which might arise when the principles were applied. The Commission also considered it important to inform doctors specializing in radiological protection about the principles to be followed by those responsible for the health protection of workers exposed to non-ionizing radiation, particularly microwaves and Laser beams. The complete text of each report in the original language is given in this volume

  12. Review of epidemiological studies of human populations exposed to ionizing radiation

    International Nuclear Information System (INIS)

    Rao, B.S.

    2002-01-01

    Epidemiological studies undertaken in many radiation exposed cohorts have played an important role in the quantification of radiation risk. Follow up of nearly 100,000 A-bomb survivors by the Radiation Effects Research Foundation (RERF), constitutes the most comprehensive human epidemiological study. The study population covered both sexes, different age groups and dose ranges from a few mSv to 2-3 Sv. Among nearly 90,000 cohorts, as on 1990, 54% are alive. Among these, 35,000 are those exposed as children at the age<20 years. Nearly 20 % of the mortalities (8,040) were due to cancer. It was estimated from the analysis of these data that among the cancers observed in LSS cohorts, 425±45 cases (335 solid cancers+90 leukaemias) were attributable to radiation exposure. Assuming a value of two for DDREF, ICRP 60, 1991 estimated a cancer risk of 5% per Sv for low dose and low dose rate exposure conditions. There have been a number of efforts to study the human populations exposed to low level radiations. Epidemiological studies on nuclear workers from USA, UK and Canada constituting 95,673 workers spanning 2,124,526 person years was reported by Cardis et al. (1995). Total number of deaths were 15,825, of which 3,976 were cancer mortalities. The excess relative risk for all cancers excluding leukaemia is -0.07 per Sv (-0.4- +0.3) and for leukaemia (excluding CLL) is 2.18 (0.1-5.7). Epidemiological studies in high background radiation areas (HBRA) of Yangjiang, China and coastal Kerala showed no detectable increase in the incidence of cancers or of any genetic disorders. Epidemiological studies in human populations exposed to elevated background radiation for several generations did not show any increase in the genetic disorders. Recent information on the background incidence of monogenic disorders in human populations and the recoverability factor of induced genetic changes suggests a risk much lower than the earlier ICRP estimates. Many other epidemiological studies of

  13. The Assessment of Primary DNA Damage in Medical Personnel Occupationally Exposed to Ionizing Radiation

    International Nuclear Information System (INIS)

    Kopjar, N.; Garaj-Vrhovac, V.

    2003-01-01

    In physico-chemical interaction with cellular DNA ionizing radiation produces a variety of primary lesions, such as single-strand breaks (SSB), alkali-labile sites, double-strand breaks (DSB), DNA-DNA and DNA-protein crosslinks, and damage to purine and pyrimidine bases. The effects of low-level exposure to ionising radiation are of concern to large number of people, including workers receiving radiation exposure on the job. It is very important to estimate absorbed doses from individuals occupationally exposed to ionising radiation for carrying out radioprotection procedures and restrict the hazards to human health. A wide range of methods is presently used for the detection of early biological effects of DNA-damaging agents in environmental and occupational settings. Currently, unstable chromosomal aberrations in peripheral blood lymphocytes, in particularly dicentrics, are the most fully developed biological indicators of ionizing radiation exposure. This methodology usually complements data obtained by physical dosimetry. As a routine, it is used whenever the individual dosimeter shows an exposure to penetrating radiation above its limit of detection. One of the advantages of cytogenetic dosimetry is that this biological dosimeter can be assessed at any moment whereas physical dosimeters are not always present in the subject. During the last years, the single cell gel electrophoresis (SCGE) or comet assay has gained widespread acceptance for genotoxicity testing. In molecular epidemiology studies DNA damage evaluated by the comet assay is utilized as a biomarker of exposure. The comet assay permits the detection of primary DNA damage and the study of repair kinetics at the level of single cells. The aim of the present study was to assess and quantificate the levels of DNA damage in peripheral blood leukocytes of medical workers occupationally exposed to ionizing radiation and corresponding unexposed control subjects. As a sensitive biomarker of exposure the

  14. A Route to Chaotic Behavior of Single Neuron Exposed to External Electromagnetic Radiation.

    Science.gov (United States)

    Feng, Peihua; Wu, Ying; Zhang, Jiazhong

    2017-01-01

    Non-linear behaviors of a single neuron described by Fitzhugh-Nagumo (FHN) neuron model, with external electromagnetic radiation considered, is investigated. It is discovered that with external electromagnetic radiation in form of a cosine function, the mode selection of membrane potential occurs among periodic, quasi-periodic, and chaotic motions as increasing the frequency of external transmembrane current, which is selected as a sinusoidal function. When the frequency is small or large enough, periodic, and quasi-periodic motions are captured alternatively. Otherwise, when frequency is in interval 0.778 electromagnetic radiation. The frequency apparently plays a more important role in determining the system behavior.

  15. Medical status of Marshallese accidentally exposed to 1954 Bravo fallout radiation: January 1980-December 1982

    International Nuclear Information System (INIS)

    Adams, W.H.; Harper, J.A.; Rittmaster, R.S.; Heotis, P.M.; Scott, W.A.

    1984-01-01

    This report updates, for 1980 through 1982, the results of continuing medical surveillance of a Marshallese population accidentally exposed to radioactive fallout in March 1954. The originally exposed Marshallese population comprised 64 persons on Rongelap Atoll who each received, on the average, an estimated 190 rads of absorbed external gamma radiation, 18 on Ailingnae Atoll who received 110 rads, and 159 on Utirik who received 11 rads. There were, in addition, 3 persons in utero on Rongelap, 1 person in utero on Ailingnae, and 8 persons in utero on Utirik who are considered exposed. The recipients of primary medical care include exposed and comparison populations as well as a rather large number of additional beneficiaries who are seen on a humanitarian basis of practical need and resource availability. In recent years, about 1400 people have been seen annually. This report, however, deals with four clearly defined groups: the remaining individuals who were exposed to radioactive fallout on Rongelap, Ailingnae, and Utirik in 1954 (including those in utero), and a comparison population of individuals from Rongelap who were unexposed. The number of persons now in each exposure category are 51, 12, 116, and 137, respectively. 100 references, 4 figures, 5 tables

  16. Medical status of Marshallese accidentally exposed to 1954 Bravo fallout radiation: January 1980-December 1982

    Energy Technology Data Exchange (ETDEWEB)

    Adams, W.H.; Harper, J.A.; Rittmaster, R.S.; Heotis, P.M.; Scott, W.A.

    1984-01-01

    This report updates, for 1980 through 1982, the results of continuing medical surveillance of a Marshallese population accidentally exposed to radioactive fallout in March 1954. The originally exposed Marshallese population comprised 64 persons on Rongelap Atoll who each received, on the average, an estimated 190 rads of absorbed external gamma radiation, 18 on Ailingnae Atoll who received 110 rads, and 159 on Utirik who received 11 rads. There were, in addition, 3 persons in utero on Rongelap, 1 person in utero on Ailingnae, and 8 persons in utero on Utirik who are considered exposed. The recipients of primary medical care include exposed and comparison populations as well as a rather large number of additional beneficiaries who are seen on a humanitarian basis of practical need and resource availability. In recent years, about 1400 people have been seen annually. This report, however, deals with four clearly defined groups: the remaining individuals who were exposed to radioactive fallout on Rongelap, Ailingnae, and Utirik in 1954 (including those in utero), and a comparison population of individuals from Rongelap who were unexposed. The number of persons now in each exposure category are 51, 12, 116, and 137, respectively. 100 references, 4 figures, 5 tables. (ACR)

  17. OLTARIS: An Efficient Web-Based Tool for Analyzing Materials Exposed to Space Radiation

    Science.gov (United States)

    Slaba, Tony; McMullen, Amelia M.; Thibeault, Sheila A.; Sandridge, Chris A.; Clowdsley, Martha S.; Blatting, Steve R.

    2011-01-01

    The near-Earth space radiation environment includes energetic galactic cosmic rays (GCR), high intensity proton and electron belts, and the potential for solar particle events (SPE). These sources may penetrate shielding materials and deposit significant energy in sensitive electronic devices on board spacecraft and satellites. Material and design optimization methods may be used to reduce the exposure and extend the operational lifetime of individual components and systems. Since laboratory experiments are expensive and may not cover the range of particles and energies relevant for space applications, such optimization may be done computationally with efficient algorithms that include the various constraints placed on the component, system, or mission. In the present work, the web-based tool OLTARIS (On-Line Tool for the Assessment of Radiation in Space) is presented, and the applicability of the tool for rapidly analyzing exposure levels within either complicated shielding geometries or user-defined material slabs exposed to space radiation is demonstrated. An example approach for material optimization is also presented. Slabs of various advanced multifunctional materials are defined and exposed to several space radiation environments. The materials and thicknesses defining each layer in the slab are then systematically adjusted to arrive at an optimal slab configuration.

  18. Health protection of persons occupationally exposed to ionising radiation in Croatia

    International Nuclear Information System (INIS)

    Zavalic, M.

    2005-01-01

    The aim of this study was to investigate the health condition of workers occupationally exposed to ionising radiation. The results for 1406 workers exposed to ionising radiations, who were regularly examined in 2004, were analysed using Statistica 5.0. The analysis included workers' case histories, frequency of illnesses and causes of temporary or permanent work disability. Of 1406 workers, 16 (1.13%) were found permanently disabled; in 11 the cause of disability was lens opacity, in 2 persistent trombocitophenia, and in 2 malignant tumour. Twenty-four workers were temporarily disabled, of whom 5 due to pregnancy. Thrombocytopenia was found in 12 men and only one woman. Anaemia was found in 4 women; dicentric chromosomes were the cause of temporary disability in one person, and tuberculosis in one person. Medical examinations of Croatian workers confirm low occupational exposure to ionising radiation. With this type of radiation, the established lens impairments could not be characterised as occupational. The two malignant tumours however were recognised as occupational diseases.(author)

  19. Sunlight-exposed biofilm microbial communities are naturally resistant to chernobyl ionizing-radiation levels.

    Directory of Open Access Journals (Sweden)

    Marie Ragon

    Full Text Available BACKGROUND: The Chernobyl accident represents a long-term experiment on the effects of exposure to ionizing radiation at the ecosystem level. Though studies of these effects on plants and animals are abundant, the study of how Chernobyl radiation levels affect prokaryotic and eukaryotic microbial communities is practically non-existent, except for a few reports on human pathogens or soil microorganisms. Environments enduring extreme desiccation and UV radiation, such as sunlight exposed biofilms could in principle select for organisms highly resistant to ionizing radiation as well. METHODOLOGY/PRINCIPAL FINDINGS: To test this hypothesis, we explored the diversity of microorganisms belonging to the three domains of life by cultivation-independent approaches in biofilms developing on concrete walls or pillars in the Chernobyl area exposed to different levels of radiation, and we compared them with a similar biofilm from a non-irradiated site in Northern Ireland. Actinobacteria, Alphaproteobacteria, Bacteroidetes, Acidobacteria and Deinococcales were the most consistently detected bacterial groups, whereas green algae (Chlorophyta and ascomycete fungi (Ascomycota dominated within the eukaryotes. Close relatives to the most radio-resistant organisms known, including Rubrobacter species, Deinococcales and melanized ascomycete fungi were always detected. The diversity of bacteria and eukaryotes found in the most highly irradiated samples was comparable to that of less irradiated Chernobyl sites and Northern Ireland. However, the study of mutation frequencies in non-coding ITS regions versus SSU rRNA genes in members of a same actinobacterial operational taxonomic unit (OTU present in Chernobyl samples and Northern Ireland showed a positive correlation between increased radiation and mutation rates. CONCLUSIONS/SIGNIFICANCE: Our results show that biofilm microbial communities in the most irradiated samples are comparable to non-irradiated samples in

  20. Sunlight-Exposed Biofilm Microbial Communities Are Naturally Resistant to Chernobyl Ionizing-Radiation Levels

    Science.gov (United States)

    Ragon, Marie; Restoux, Gwendal; Moreira, David; Møller, Anders Pape; López-García, Purificación

    2011-01-01

    Background The Chernobyl accident represents a long-term experiment on the effects of exposure to ionizing radiation at the ecosystem level. Though studies of these effects on plants and animals are abundant, the study of how Chernobyl radiation levels affect prokaryotic and eukaryotic microbial communities is practically non-existent, except for a few reports on human pathogens or soil microorganisms. Environments enduring extreme desiccation and UV radiation, such as sunlight exposed biofilms could in principle select for organisms highly resistant to ionizing radiation as well. Methodology/Principal Findings To test this hypothesis, we explored the diversity of microorganisms belonging to the three domains of life by cultivation-independent approaches in biofilms developing on concrete walls or pillars in the Chernobyl area exposed to different levels of radiation, and we compared them with a similar biofilm from a non-irradiated site in Northern Ireland. Actinobacteria, Alphaproteobacteria, Bacteroidetes, Acidobacteria and Deinococcales were the most consistently detected bacterial groups, whereas green algae (Chlorophyta) and ascomycete fungi (Ascomycota) dominated within the eukaryotes. Close relatives to the most radio-resistant organisms known, including Rubrobacter species, Deinococcales and melanized ascomycete fungi were always detected. The diversity of bacteria and eukaryotes found in the most highly irradiated samples was comparable to that of less irradiated Chernobyl sites and Northern Ireland. However, the study of mutation frequencies in non-coding ITS regions versus SSU rRNA genes in members of a same actinobacterial operational taxonomic unit (OTU) present in Chernobyl samples and Northern Ireland showed a positive correlation between increased radiation and mutation rates. Conclusions/Significance Our results show that biofilm microbial communities in the most irradiated samples are comparable to non-irradiated samples in terms of general

  1. Review of NCRP radiation dose limit for embryo and fetus in occupationally-exposed women

    International Nuclear Information System (INIS)

    Anon.

    1977-01-01

    On the basis of the current review, the NCRP has decided to make no change in the current recommendation of its radiation dose limit to the unborn. The NCRP recommendation is restated here as follows: During the entire gestation period, the maximum permissible dose equivalent to the embryo-fetus from occupational exposure of the expectant mother should be 0.5 rem. Since the preparation of the 1971 report there has been no new evidence concerning teratogenic or carcinogenic effects of irradiation of the embryo-fetus that would justify a change in the limit in either direction. It is implicit in this position and recommendation that women who can reasonably be expected to be pregnant should not, in certain instances, be exposed to the same radiation environment as women who are not considered fertile or as men. This applies particularly to conditions where radiation workers can receive dose equivalents of 0.5 rem or more in short periods

  2. The growth and development of Schistosoma mansoni in mice exposed to sublethal doses of radiation

    International Nuclear Information System (INIS)

    Aitken, R.; Wilson, R.A.

    1989-01-01

    The maturation of Schistosoma mansoni was studied in mice exposed to various sublethal doses of radiation. Although the treatment of mice with 500 rads of radiation prior to infection did not alter parasite maturation, doses in excess of 500 rads led to a reduction in worm burden. This could not be attributed to a delay in the arrival of parasites in the hepatic portal system. Worms developing in mice treated with 800 rads commenced egg-laying about 1 wk later than worms in intact mice, and the rate of egg deposition appeared to be lower in irradiated hosts. The data demonstrate that exposure of C57BL/6 mice to doses of radiation in excess of 500 rads impairs their ability to carry infections of S. mansoni. The findings do not support the hypothesis that primary worm burdens in the mouse are controlled by a host immune response

  3. Aspects of research on effects of population exposed to low level radiation in China

    International Nuclear Information System (INIS)

    Wei, L.

    1992-01-01

    Research works of epidemiology and experimental biology concerning health effects on populations exposed to low level ionizing radiation in China have been reviewed, with emphasis on the studies of mortality of malignancies and prevalence of hereditary diseases in a high background radiation area (HBRA) (radiation level is about three times of the control area of normal background CA), where the inhabitant families have lived for many generations. About one million person-years in HBRA and as many in CA were observed for cancer mortality. Statistical analysis showed that no difference was found either in mortality of all cancers or leukemias between HBRA and CA. The incidence of Down Syndrome in HBRA was within the range of spontaneous incidence and dependent on age of maternity. The characteristics of adaptive response induced by low level irradiation in humans as well as in experimental animal lymphocytes observed in Chinese laboratories are also discussed in this presentation

  4. Compensation for damage to workers health exposed to ionizing radiation in Argentina

    International Nuclear Information System (INIS)

    Sobehart, Leonardo J.

    2003-01-01

    The objective of this report is to analyze the possibility to establish a scheme to compensate damage to workers health exposed to ionizing radiation in Argentina for those cases in which it is possible to assume that the exposure to ionizing radiation is the cause of the cancer suffered by the worker. The proposed scheme is based on the recommendations set out in the 'International Conference on Occupational Radiation Protection: Protecting Workers against Exposure to Ionization Radiation, held in Geneva, Switzerland, August 26-30, 2002. To this end, the study analyzes the present state of scientific knowledge on cancer causation due to genotoxic factors, and the accepted form of the doses-response curve, for the human beings exposure to ionization radiation at low doses with low doses rates. Finally, the labor laws and regulations related to damage compensation; in particular the present Argentine Labor Law; the National Russian Federal Occupational Radiological Health Impairment and Workmen Compensation, the United Kingdom Compensation Scheme for Radiation-linked Diseases and the United States Energy Employees Occupational Illness Compensation Program are described. (author)

  5. Personal dosimetry TLD 100 in orthopedic surgeons exposed to ionizing radiation in Bogota - Colombia

    International Nuclear Information System (INIS)

    Sierra C, B. Y.; Jimenez, Y.; Plazas, M. C.; Eslava S, J.; Groot R, H.

    2014-08-01

    Orthopedic surgeons should be considered as professionals occupationally exposed to ionizing radiation, for using C arc (fluoroscope) an equipment of X type radiation emission, during surgical procedures for imaging generation. Some health institutes, use of C arc under uncontrolled circumstances, such a lack of dosimetry control, incomplete or absence of personnel protective elements and protective measures, which in turn, lead to a high exposition to the personnel. Materials and methods. Study of double match cohort by age and gender, was conducted, in four health institutions of second and third level of attention in Bogota city. Personal dosimetry measurements with TLD-100 dosimetry crystals in both cohorts and environmental dosimetry in each of operation rooms used for orthopedic procedures, were carry out during six months of follow up. Dosimetry crystals were read in a Harshaw 4500 - Bicron equipment, in the Medical Physics Laboratory of National University of Colombia. Results. Dosimetry measurements are compatibles with those of occupationally exposed personnel 3.44 mSv/6 m CI 95% (1.66-3.99), even does not overpass ICRP recommendations, are higher as were expect at the beginning of the study. The median of effective accumulative dose in thorax is 3,4 mSv CI 95% (1,66-3,99), higher in comparison with neck value 2,7 mSv CI 95% (1,73-3,80) and hand dosimetry 1,42 mSv CI 95% (0,96-2,34). Conclusions: Orthopedic surgeons should be considered occupational exposed to ionizing radiation, who has to accomplish to the radiological protection measures, dosimetric follow up and maintenance of the used X ray equipment. It was confirm throughout this study that dosimetry shows higher levels as expected at the beginning of the study, compatible with occupationally exposed personnel. (Author)

  6. Alteration of cytokine profiles in mice exposed to chronic low-dose ionizing radiation

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Suk Chul [Radiation Health Research Institute, Korea Hydro and Nuclear Power Co., Ltd., 388-1, Ssangmun-dong, Dobong-gu, Seoul 132-703 (Korea, Republic of); Lee, Kyung-Mi [Global Research Lab, BAERI Institute, Department of Biochemistry and Molecular Biology, Korea University College of Medicine, Seoul 136-705 (Korea, Republic of); Kang, Yu Mi [Radiation Health Research Institute, Korea Hydro and Nuclear Power Co., Ltd., 388-1, Ssangmun-dong, Dobong-gu, Seoul 132-703 (Korea, Republic of); Kim, Kwanghee [Global Research Lab, BAERI Institute, Department of Biochemistry and Molecular Biology, Korea University College of Medicine, Seoul 136-705 (Korea, Republic of); Kim, Cha Soon; Yang, Kwang Hee; Jin, Young-Woo [Radiation Health Research Institute, Korea Hydro and Nuclear Power Co., Ltd., 388-1, Ssangmun-dong, Dobong-gu, Seoul 132-703 (Korea, Republic of); Kim, Chong Soon [Department of Nuclear Medicine, Haeundae Paik Hospital, Inje University, Busan 612-030 (Korea, Republic of); Kim, Hee Sun, E-mail: hskimdvm@khnp.co.kr [Radiation Health Research Institute, Korea Hydro and Nuclear Power Co., Ltd., 388-1, Ssangmun-dong, Dobong-gu, Seoul 132-703 (Korea, Republic of)

    2010-07-09

    While a high-dose of ionizing radiation is generally harmful and causes damage to living organisms, a low-dose of radiation has been shown to be beneficial in a variety of animal models. To understand the basis for the effect of low-dose radiation in vivo, we examined the cellular and immunological changes evoked in mice exposed to low-dose radiation at very low (0.7 mGy/h) and low (3.95 mGy/h) dose rate for the total dose of 0.2 and 2 Gy, respectively. Mice exposed to low-dose radiation, either at very low- or low-dose rate, demonstrated normal range of body weight and complete blood counts. Likewise, the number and percentage of peripheral lymphocyte populations, CD4{sup +} T, CD8{sup +} T, B, or NK cells, stayed unchanged following irradiation. Nonetheless, the sera from these mice exhibited elevated levels of IL-3, IL-4, leptin, MCP-1, MCP-5, MIP-1{alpha}, thrombopoietin, and VEGF along with slight reduction of IL-12p70, IL-13, IL-17, and IFN-{gamma}. This pattern of cytokine release suggests the stimulation of innate immunity facilitating myeloid differentiation and activation while suppressing pro-inflammatory responses and promoting differentiation of naive T cells into T-helper 2, not T-helper 1, types. Collectively, our data highlight the subtle changes of cytokine milieu by chronic low-dose {gamma}-radiation, which may be associated with the functional benefits observed in various experimental models.

  7. Cytogenetic Analysis In Blood Lymphocyte From Workers Occupationally Exposed To Low Levels Of Radiation

    International Nuclear Information System (INIS)

    Rahimah Abdul Rahim; Mohd Rodzi Ali; Noraisyah Mohd Yusof; Juliana Mahamad Napiah; Yahaya Talib; Shafii Khamis

    2016-01-01

    Whether it comes from the ground, the sky, or medical treatment, humans are constantly exposed to ionizing radiation from the world around them. This is a normal occurrence, and has always been the case. According to the IAEA International Basic Safety Standard, the radiation dose for public is not more than 1 mSv per year. That is just an average though, and the actual figure may fluctuate widely per person depending on where they live and the medical procedures they had that year. The international standard is to allow people who work with and around radioactive material (researchers, nuclear power plant workers, X-ray technicians and others) to have exposures of not more than 20 mSv total per year. The 20 mSv annual dose is considered to be safe and not significantly increase the risk for radiation-related health effects. Biological dosimetry based on the analysis of micronuclei in the cytokinesis-block micronucleus (CBMN) assay can be used as an alternative method for scoring dicentric chromosomes in the field of radiation protection. Bio dosimetry is mainly performed, in addition to the physical dosimetry, with the aim of individual dose assessment. The aim of the present study was to perform a cytogenetic analysis in peripheral blood lymphocyte of 30 individuals occupationally exposed to low level of ionizing radiation and compare the result with 30 controls using CBMN assay. Number of bi-nucleated cell and micronuclei were scored and statistical analysis was done to see the effect of micronuclei with gender, age and occupation. In conclusion, scoring of micronuclei is a useful cytogenetic monitoring for radiation workers and assessment of genetic damage. (author)

  8. Onset of Coulomb explosion in small silicon clusters exposed to strong-field laser pulses

    Science.gov (United States)

    Sayres, S. G.; Ross, M. W.; Castleman, A. W., Jr.

    2012-05-01

    It is now well established that, under intense laser illumination, clusters undergo enhanced ionization compared to their isolated atomic and molecular counterparts being subjected to the same pulses. This leads to extremely high charge states and concomitant Coulomb explosion. Until now, the cluster size necessary for ionization enhancement has not been quantified. Here, we demonstrate that through the comparison of ion signal from small covalently bound silicon clusters exposed to low intensity laser pulses with semi-classical theory, their ionization potentials (IPs) can be determined. At moderate laser intensities the clusters are not only atomized, but all valence electrons are removed from the cluster, thereby producing up to Si4+. The effective IPs for the production of the high charge states are shown to be ˜40% lower than the expected values for atomic silicon. Finally, the minimum cluster size responsible for the onset of the enhanced ionization is determined utilizing the magnitude of the kinetic energy released from the Coulomb explosion.

  9. Application of the Alkaline comet assay in bio monitoring of medical personnel occupationally exposed to ionizing radiation

    International Nuclear Information System (INIS)

    Kopjar, N.; Graj-Vrhovac, V.

    2002-01-01

    Ionising radiation is a ubiquitous environmental physical agent whose DNA damaging effects are fairly well established. The effects of low-level exposure to ionizing radiation are of concern to large number of people, including workers receiving radiation exposure on the job. Medical radiation workers are employees of hospitals, clinics and private offices where radiation is used in the process of delivering health care to humans. These workers can be categorised into two groups exposed employees who receive at least a minimum detectable exposure during a one-year period, and potentially exposed employees who work in the vicinity of radiation but whose exposures are below detectable limits. The exposure of patients and workers to radiation in medicine is a direct consequence of the use of radiation to improve the health of the individuals. Trends in radiation exposure of both patients and workers are effected not only by developments in radiation protection, but also by dose in the practice of medicine. It is very important to estimate absorbed doses from individuals occupationally exposed to ionizing radiation for carrying out radioprotection procedures and restrict the hazards to human health. The extent of health hazards is difficult to assess. Therefore, development of procedures that can be used to precisely identify health hazards in the exposed populations is a most significant approach towards establishing effective programs for disease prevention

  10. Cardiovascular changes in atherosclerotic ApoE-deficient mice exposed to Co60 (γ radiation.

    Directory of Open Access Journals (Sweden)

    Prem Kumarathasan

    Full Text Available BACKGROUND: There is evidence for a role of ionizing radiation in cardiovascular diseases. The goal of this work was to identify changes in oxidative and nitrative stress pathways and the status of the endothelinergic system during progression of atherosclerosis in ApoE-deficient mice after single and repeated exposure to ionizing radiation. METHODS AND RESULTS: B6.129P2-ApoE tmlUnc mice on a low-fat diet were acutely exposed (whole body to Co60 (γ (single dose 0, 0.5, and 2 Gy at a dose rate of 36.32 cGy/min, or repeatedly (cumulative dose 0 and 2 Gy at a dose-rate of 0.1 cGy/min for 5 d/wk, over a period of 4 weeks. Biological endpoints were investigated after 3-6 months of recovery post-radiation. The nitrative stress marker 3-nitrotyrosine and the vasoregulator peptides endothelin-1 and endothelin-3 in plasma were increased (p<0.05 in a dose-dependent manner 3-6 months after acute or chronic exposure to radiation. The oxidative stress marker 8-isoprostane was not affected by radiation, while plasma 8-hydroxydeoxyguanosine and L-3,4-dihydroxyphenylalanine decreased (p<0.05 after treatment. At 2Gy radiation dose, serum cholesterol was increased (p = 0.008 relative to controls. Percent lesion area increased (p = 0.005 with age of animal, but not with radiation treatment. CONCLUSIONS: Our observations are consistent with persistent nitrative stress and activation of the endothelinergic system in ApoE-/- mice after low-level ionizing radiation exposures. These mechanisms are known factors in the progression of atherosclerosis and other cardiovascular diseases.

  11. Regulation on radiation protection health care of workers exposed to ionizing radiation. - Regulation on radiation protection health care - of the 25 Mar 1986

    International Nuclear Information System (INIS)

    1986-01-01

    The present regulation will be in force on 1 July 1986 and supersedes a regulation from 29 September 1970. It regulates the medical surveillance with regard to radiation protection for all kinds of workers with an increased risk of being exposed to ionizing radiation such as e.g. reactor operators and miners. Examinations have to be performed according to directions of the SAAS including further measures if necessary regarding clinical occupational and radiation protection medicine. The task of the firms, the managers, the medical officers, and the SAAS are distinctly marked

  12. Possible cause for altered spatial cognition of prepubescent rats exposed to chronic radiofrequency electromagnetic radiation.

    Science.gov (United States)

    Narayanan, Sareesh Naduvil; Kumar, Raju Suresh; Karun, Kalesh M; Nayak, Satheesha B; Bhat, P Gopalakrishna

    2015-10-01

    The effects of chronic and repeated radiofrequency electromagnetic radiation (RFEMR) exposure on spatial cognition and hippocampal architecture were investigated in prepubescent rats. Four weeks old male Wistar rats were exposed to RF-EMR (900 MHz; SAR-1.15 W/kg with peak power density of 146.60 μW/cm(2)) for 1 h/day, for 28 days. Followed by this, spatial cognition was evaluated by Morris water maze test. To evaluate the hippocampal morphology; H&E staining, cresyl violet staining, and Golgi-Cox staining were performed on hippocampal sections. CA3 pyramidal neuron morphology and surviving neuron count (in CA3 region) were studied using H&E and cresyl violet stained sections. Dendritic arborization pattern of CA3 pyramidal neuron was investigated by concentric circle method. Progressive learning abilities were found to be decreased in RF-EMR exposed rats. Memory retention test performed 24 h after the last training revealed minor spatial memory deficit in RF-EMR exposed group. However, RF-EMR exposed rats exhibited poor spatial memory retention when tested 48 h after the final trial. Hirano bodies and Granulovacuolar bodies were absent in the CA3 pyramidal neurons of different groups studied. Nevertheless, RF-EMR exposure affected the viable cell count in dorsal hippocampal CA3 region. RF-EMR exposure influenced dendritic arborization pattern of both apical and basal dendritic trees in RF-EMR exposed rats. Structural changes found in the hippocampus of RF-EMR exposed rats could be one of the possible reasons for altered cognition.

  13. Association between sperm DNA integrity and seminal plasma antioxidant levels in health workers occupationally exposed to ionizing radiation

    International Nuclear Information System (INIS)

    Kumar, Dayanidhi; Salian, Sujith Raj; Kalthur, Guruprasad; Uppangala, Shubhashree; Kumari, Sandhya; Challapalli, Srinivas; Chandraguthi, Shrinidhi Gururajarao; Jain, Navya; Krishnamurthy, Hanumanthappa; Kumar, Pratap; Adiga, Satish Kumar

    2014-01-01

    There is a paucity of data regarding the association between occupational radiation exposure and risk to human fertility. Recently, we provided the first evidence on altered sperm functional characteristics, DNA damage and hypermethylation in radiation health workers. However, there is no report elucidating the association between seminal plasma antioxidants and sperm chromatin integrity in occupationally exposed subjects. Here, we assessed the seminal plasma antioxidants and lipid peroxidation level in 83 men who were occupationally exposed to ionizing radiation and then correlated with the sperm chromatin integrity. Flow cytometry based sperm chromatin integrity assay revealed a significant decline in αt value in the exposed group in comparison to the non-exposed group (P<0.0001). Similarly, both total and reduced glutathione levels and total antioxidant capacity in the seminal plasma were significantly higher in exposed group than the non-exposed group (P<0.01, 0.001 and 0.0001, respectively). However, superoxide dismutase level and malondialdehyde level, which is an indicator of lipid peroxidation in the seminal plasma, did not differ significantly between two groups. The total antioxidant capacity (TAC) and GSH level exhibited a positive correlation with sperm DNA integrity in exposed subjects. To conclude, this study distinctly shows that altered sperm chromatin integrity in radiation health workers is associated with increase in seminal plasma antioxidant level. Further, the increased seminal plasma GSH and TAC could be an adaptive measure to tackle the oxidative stress to protect genetic and functional sperm deformities in radiation health workers. - Highlights: • Seminal plasma antioxidants were measured in men occupationally exposed to radiation. • Sperm chromatin integrity was significantly affected in the exposed group. • Glutathione and total antioxidant capacity was significantly higher in exposed group. • Sperm DNA damage in exposed subjects

  14. Association between sperm DNA integrity and seminal plasma antioxidant levels in health workers occupationally exposed to ionizing radiation

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Dayanidhi; Salian, Sujith Raj; Kalthur, Guruprasad; Uppangala, Shubhashree; Kumari, Sandhya [Division of Clinical Embryology, Department of Obstetrics and Gynecology, Kasturba Medical College, Manipal University, Manipal 576104 (India); Challapalli, Srinivas [Department of Radiotherapy, Kasturba Medical College, Mangalore (India); Chandraguthi, Shrinidhi Gururajarao [Department of Radiotherapy and Oncology, Kasturba Medical College, Manipal (India); Jain, Navya; Krishnamurthy, Hanumanthappa [National Centre for Biological Sciences, Bangalore (India); Kumar, Pratap [Department of Obstetrics and Gynecology, Kasturba Medical College, Manipal University, Manipal (India); Adiga, Satish Kumar, E-mail: satish.adiga@manipal.edu [Division of Clinical Embryology, Department of Obstetrics and Gynecology, Kasturba Medical College, Manipal University, Manipal 576104 (India)

    2014-07-15

    There is a paucity of data regarding the association between occupational radiation exposure and risk to human fertility. Recently, we provided the first evidence on altered sperm functional characteristics, DNA damage and hypermethylation in radiation health workers. However, there is no report elucidating the association between seminal plasma antioxidants and sperm chromatin integrity in occupationally exposed subjects. Here, we assessed the seminal plasma antioxidants and lipid peroxidation level in 83 men who were occupationally exposed to ionizing radiation and then correlated with the sperm chromatin integrity. Flow cytometry based sperm chromatin integrity assay revealed a significant decline in αt value in the exposed group in comparison to the non-exposed group (P<0.0001). Similarly, both total and reduced glutathione levels and total antioxidant capacity in the seminal plasma were significantly higher in exposed group than the non-exposed group (P<0.01, 0.001 and 0.0001, respectively). However, superoxide dismutase level and malondialdehyde level, which is an indicator of lipid peroxidation in the seminal plasma, did not differ significantly between two groups. The total antioxidant capacity (TAC) and GSH level exhibited a positive correlation with sperm DNA integrity in exposed subjects. To conclude, this study distinctly shows that altered sperm chromatin integrity in radiation health workers is associated with increase in seminal plasma antioxidant level. Further, the increased seminal plasma GSH and TAC could be an adaptive measure to tackle the oxidative stress to protect genetic and functional sperm deformities in radiation health workers. - Highlights: • Seminal plasma antioxidants were measured in men occupationally exposed to radiation. • Sperm chromatin integrity was significantly affected in the exposed group. • Glutathione and total antioxidant capacity was significantly higher in exposed group. • Sperm DNA damage in exposed subjects

  15. Sublethal effects in Atlantic salmon (Salmo salar) exposed to mixtures of copper, aluminium and gamma radiation

    International Nuclear Information System (INIS)

    Heier, Lene Sørlie; Teien, Hans Christian; Oughton, Deborah; Tollefsen, Knut-Erik; Olsvik, Pål A.; Rosseland, Bjørn Olav; Lind, Ole Christian; Farmen, Eivind; Skipperud, Lindis; Salbu, Brit

    2013-01-01

    The present study was designed to investigate the effects in presmolt of Atlantic salmon (Salmo salar) exposed to copper (Cu), aluminium (Al) and gamma radiation, individually or in combination. Fish were exposed for 48 h to metals added to lake water; 10, 40 and 80 μg Cu/L, 250 μg Al/L and a combination of 40 μg Cu/L and 250 μg Al/L. In addition, gamma radiation (4–70 mGy delivered over 48 h) was added as an additional exposure stressor. Selected endpoints were chosen to reveal different toxic mechanisms and included Cu and Al accumulation on gills, blood chemistry and haematological variables (plasma sodium and chloride, haematocrit, glucose), hepatic levels of reduced and oxidised glutathione (GSH and GSSG) and hepatic transcriptional response of glutathione peroxidase (GPx), gamma-glutamylcysteine synthetase (GCS), metallothionein (MT) and ubiquitin. Exposure to Cu alone resulted in gill accumulation of Cu, reduction of plasma ions and increased transcriptional response of GPx, MT and ubiquitin. Exposure to Al alone reduced plasma ion levels but did not affect any of the hepatic biomarkers except for ubiquitin. The combined metal exposure (Cu + Al) altered the GSH levels, however GPx and MT were not affected suggesting a different mode of detoxification in the combined exposure. Gamma radiation appeared to influence GSH and ubiquitin levels. The observed effects seemed to be both stressor and concentration dependent

  16. [Morphological structure of rat epiphysis exposed to electromagnetic radiation from communication devices].

    Science.gov (United States)

    Yashchenko, S G; Rybalko, S Yu

    Pineal gland is one of the most important components of homeostasis - the supporting system of the body. It participates in the launch of stress responses, restriction of their development, prevention of adverse effects on the body. There was proved an impact of electromagnetic radiation on the epiphysis. However, morphological changes in the epiphysis under exposure to electromagnetic radiation of modern communication devices are studied not sufficiently. For the time present the population is daily exposed to electromagnetic radiation, including local irradiation on the brain. These date determined the task of this research - the study of the structure of rat pineal gland under the exposure to electromagnetic radiation from personal computers and mobile phones. These date determined the task of this research - the study of the structure of rat pineal gland under the exposure to electromagnetic radiation from personal computers and mobile phones. Performed transmission electron microscopy revealed signs of degeneration of dark and light pinealocytes. These signs were manifested in the development of a complex of general and specific morphological changes. There was revealed the appearance of signs of aging and depletion transmission electron microscopy both in light and dark pinealocytes. These signs were manifested in the accumulation of lipofuscin granules and electron-dense "brain sand", the disappearance of nucleoli, cytoplasm vacuolization and mitochondrial cristae enlightenment.

  17. Evaluation of radiosensitivity hemocytes of Biomphalaria glabrata exposed to gamma radiation

    International Nuclear Information System (INIS)

    Silva, L.R.S.; Amaral, A.J.; Silva, E.B.; Amancio, F.F.; Melo, A.M.M.A.

    2013-01-01

    The mollusc Biomphalaria glabrata have characteristics that allow them to be identified as an animal model ideal for monitoring areas exposed to chemical agents and physical. This study evaluated the effect of ionizing radiation from Cobalt-60 in haemocytes present in the hemolymph of Biomphalaria glabrata, with the goal of using these cells as indicators of the presence of radiation in aquatic environments. The mollusks were divided into five groups: one control and four subjected doses of 25, 35, 45 and 55 Gy of gamma radiation. After 48 hours of irradiation, the clam hemolymph was collected and slides were prepared and stained with Giemsa for analyses under a light microscope. Statistical analysis was performed using ANOVA and Tukey's test, p <0.05. The results showed that the total number of cells after irradiation reduced compared to control except at a dose of 55 Gy. During data analysis, morphological changes were observed in haemocytes of mollusks subjected to doses of 35, 45 and 55 Gy. These modifications consisted of nucleus bilobulated and nucleo plasmatic bridges. Another change was exclusively observed in the cellular exposure of 55 Gy, where hemocytes showed misshapen nuclei and cytoplasm vacuolisation, suggestive of apoptosis. It is concluded that hemocytes are sensitive to radiation and can be used as indicators of the presence of high doses of ionizing radiation in aquatic environments. (author)

  18. Survey of studies of occupational populations exposed to low-level radiation

    International Nuclear Information System (INIS)

    Marks, S.

    1980-04-01

    Studies of occupational populations exposed to large doses of radiation, principally from the ingestion of radium by dial painters and inhalation of radon and its daughters by miners, have provided important information on the health effects of those radioisotopes. Studies of medical radiologists, military personnel exposed to nuclear tests, and factory workers exposed to thorium are in progress. Employees of DOE-contractor facilities and of naval shipyards are also under study. Personnel dosimetry data are generally available for the latter category of occupational populations. Reasons for conducting the studies include interest in exploring the verification at low exposure levels of results of studies of heavily exposed populations and the responsibility of the employer to maintain adequate surveillance of the health of his workers by conducting appropriate epidemiologic studies. The low level of exposure of workers in facilities where adequate personnel dosimetry records are available make it unlikely that the results of such studies can be used to provide health risk estimates in the near future

  19. Production and excision of thymine damage in the DNA of mammalian cells exposed to high-LET radiations

    International Nuclear Information System (INIS)

    Mattern, M.R.; Welch, G.P.

    1979-01-01

    HeLa S3 and Chinese hamster ovary cells were irradiated with high doses of carbon ions having linear energy transfers (LETs) of 170 and 780 keV/μm. The DNA was analyzed for 5,6-dihydroxydihydrothymine (t'-type) radiation products both before and after postirradiation incubation at 37 0 C. In HeLa cells, 2.1 x 10 -5 ring-damaged thymines were produced per kilorad per 10 6 daltons after irradiation with high-LET carbon ions - approximately one-fifth the efficiency of t' formation in HeLa cells exposed to low-LET x rays. t' products were also formed less efficiently in Chinese hamster ovary cells exposed to carbon ions than in those exposed to x rays. In both cell lines, up to 80% of the t' formed initially was excised selectively from the DNA during 60 min of postirradiation incubation at 37 0 C. Product excision was accompanied by small amounts of DNA degradation (less than 1%). Radiation with LET of 170 keV/μm - nearly the most effective LET for cell killing and the generation of unrejoined DNA strand breaks - produced ring-damaged thymines that were removed selectively from the DNA. This result is consistent with the conclusion that t'-type products do not contribute substantially to lethality after high-LET irradiation, although the alternative possibilities remain that t' is not excised as efficiently after biological doses, or that a particular subclass of t' or defective postexcision events contribute to cell killing

  20. Exposing exposure: automated anatomy-specific CT radiation exposure extraction for quality assurance and radiation monitoring.

    Science.gov (United States)

    Sodickson, Aaron; Warden, Graham I; Farkas, Cameron E; Ikuta, Ichiro; Prevedello, Luciano M; Andriole, Katherine P; Khorasani, Ramin

    2012-08-01

    To develop and validate an informatics toolkit that extracts anatomy-specific computed tomography (CT) radiation exposure metrics (volume CT dose index and dose-length product) from existing digital image archives through optical character recognition of CT dose report screen captures (dose screens) combined with Digital Imaging and Communications in Medicine attributes. This institutional review board-approved HIPAA-compliant study was performed in a large urban health care delivery network. Data were drawn from a random sample of CT encounters that occurred between 2000 and 2010; images from these encounters were contained within the enterprise image archive, which encompassed images obtained at an adult academic tertiary referral hospital and its affiliated sites, including a cancer center, a community hospital, and outpatient imaging centers, as well as images imported from other facilities. Software was validated by using 150 randomly selected encounters for each major CT scanner manufacturer, with outcome measures of dose screen retrieval rate (proportion of correctly located dose screens) and anatomic assignment precision (proportion of extracted exposure data with correctly assigned anatomic region, such as head, chest, or abdomen and pelvis). The 95% binomial confidence intervals (CIs) were calculated for discrete proportions, and CIs were derived from the standard error of the mean for continuous variables. After validation, the informatics toolkit was used to populate an exposure repository from a cohort of 54 549 CT encounters; of which 29 948 had available dose screens. Validation yielded a dose screen retrieval rate of 99% (597 of 605 CT encounters; 95% CI: 98%, 100%) and an anatomic assignment precision of 94% (summed DLP fraction correct 563 in 600 CT encounters; 95% CI: 92%, 96%). Patient safety applications of the resulting data repository include benchmarking between institutions, CT protocol quality control and optimization, and cumulative

  1. Cerenkov light spectrum in an optical fiber exposed to a photon or electron radiation therapy beam

    International Nuclear Information System (INIS)

    Lambert, Jamil; Yin Yongbai; McKenzie, David R.; Law, Sue; Suchowerska, Natalka

    2009-01-01

    A Cerenkov signal is generated when energetic charged particles enter the core of an optical fiber. The Cerenkov intensity can be large enough to interfere with signals transmitted through the fiber. We determine the spectrum of the Cerenkov background signal generated in a poly(methyl methacrylate) optical fiber exposed to photon and electron therapeutic beams from a linear accelerator. This spectral measurement is relevant to discrimination of the signal from the background, as in scintillation dosimetry using optical fiber readouts. We find that the spectrum is approximated by the theoretical curve after correction for the wavelength dependent attenuation of the fiber. The spectrum does not depend significantly on the angle between the radiation beam and the axis of the fiber optic but is dependent on the depth in water at which the fiber is exposed to the beam.

  2. [Clinico-morphological peculiarities of thyroid cancer among children exposed to the Chernobyl disaster radiation].

    Science.gov (United States)

    Iakovleva, I N; Shishkov, R V; Poliakov, V G; Pankova, P A

    2008-01-01

    The paper deals with a comparison of clinico-morphological patterns of sporadic thyroid cancer and that in pediatric patients exposed to radiation during the Chernobyl disaster. The latter are highly prone to both local and regional metastatic spread to the lymph nodes (intrathyroid distribution--61%; extension through capsule--42%, and metastases to the neck lymph nodes--66%). However, these data do not differ significantly from those for intact areas. Yet, cancer occurs in exposed cohorts at an earlier stage: its incidence at age 4-6 is 2-3.5 higher and that of relapse such as presentation of latent metastases to the lymph nodes and tumor foci development in residual tumor tissue is 1.6 times the average. Also, morphological patterns have changed: typical papillary cancer incidence has dropped by half while the diffuse follicular variety has grown 1.8-fold.

  3. Primary functions of the first Japanese large-scale facility for exposing small animals to radon

    International Nuclear Information System (INIS)

    Ishimori, Yuu; Tanaka, Hiroshi; Mitsunobu, Fumihiro; Yamaoka, Kiyonori; Kataoka, Takahiro; Sakoda, Akihiro

    2010-01-01

    The Japan Atomic Energy Agency (JAEA) and Okayama University have carried out the experimental animal study and its related studies since 2007 in order to examine the physiological effects of radon in detail. Thus, a radon test facility for small animals was developed in order to increase the statistical certainty of our animal tests. This paper illustrates the performances of that facility, the first large-scale facility of its types in Japan. The facility has a potential of approximately 150 mouse-scale tests at the same time. The apparatus for exposing small animals to radon has six animal chamber groups each of which consists of five independent cages. Different radon concentrations in each animal chamber group are available. The major functions of the facility controlling radon and avoiding thoron were shown theoretically and experimentally. The relative standard deviation of radon concentration at the highest concentration group was about 5%, although the lower concentration groups seemed to be affected by variations in background radon. (author)

  4. Growth and development over the first year of life of grandchildren of persons being exposed to occupational external radiation

    International Nuclear Information System (INIS)

    Petrushkina, N.P.; Perminova, L.E.

    1993-01-01

    Physical and psychomotor development of children whose grandparents were occupationally exposed to chronic external gamma-radiation at doses 0.1 to over 400 Gy was studied. Mean values of the major anthropometric parameters at first and over the first year of life, growth and mass increment rates were assessed, as well as body length growth per quarter, age of the doubling and tripling the body mass at birth, and age of the cross-over of the head and chest circumference values. Share of infants with the harmonic and dysharmonic development, of those small-for-date and large-for-date were estimated, and the psychomotor development and the rate of biologic maturation were assessed. No significant differences between studied parameters of the test group and the reference group were detected

  5. Gastrointestinal drug absorption in rats exposed to 60Co γ-radiation

    International Nuclear Information System (INIS)

    Brady, M.E.

    1976-01-01

    Following exposure of the gastrointestinal (GI) tract to ionizing radiation, its structure and function are altered for several days. Such alterations may affect the bioavailability of orally administered drugs. The potential mechanisms by which radiation may affect drug absorption were explored by studying the absorption of four test drugs, sulfanilamide, bretylium, sulfisoxazole acetyl, and riboflavin, in rats that were exposed to 850 R cobalt-60 gamma-radiation or sham irradiated. In one series of experiments, the drugs were administered orally and the amount of drug excreted in urine was used as a measure of the extent of their absorption. Cumulative urinary excretion of the drugs was shown to be a valid measure of absorption since it was not affected by radiation after intravenous administration of the drugs. At one day post-irradiation, the extent of absorption of sulfanilamide and bretylium was not affected by radiation but the absorption of sulfisoxazole acetyl and riboflavin was increased. At five days post-irradiation, there was no detectable difference between irradiated and control animals in the extent of absorption of the drugs. The fraction of sulfanilamide excreted in the urine as 4 N-conjugate was increased at one day post-irradiation. The increased excretion of metabolite appeared to result from metabolism of the drug by gut flora prior to absorption. This study shows that radiation-induced alterations in the absorption of orally administered drugs are due primarily to slowed gastric emptying. In general, slowed gastric emptying causes the rate of drug absorption to decline. The extent of absorption of drugs that are normally well absorbed is not affected by radiation while the extent of absorption of drugs that normally are absorbed poorly may be increased after irradiation of the GI tract

  6. Cytogenetic studies in persons, professionally exposed to low doses ionizing radiation

    International Nuclear Information System (INIS)

    Bulanova, M.; Ivanov, B.; Khristova, M.; Praskova, L.; Mikhajlov, M.; Dovev, I.

    1981-01-01

    Cytogenetic techniques were used to examine peripheral lymphocytes taken from 33 subjects employed at the IRT-2000-Sofia Nuclear Reactor and exposed to mixed gamma and neutron radiation in its Zone A. Physical dosimetry data (from pen and film personnel dosimeters) showed the exposures to be below maximum permissible levels, in complience with Radiation Safety Norms in the P.R. of Bulgaria (1972). The subjects were distributed into three groups according to the length of their occupational experience as radiation workers. Comparisons were made with cytogenetic findings in the lymphocyte cultures taken from 30 subjects with no occupational radiation exposure. Radiation workers exhibited a significant increase in chromosomal damage of the chromosome and chromatid type. Subjects with 5-10 years of occupational experience had a higher degree of chromosomal damage than the less-than-5-years group. For persons with more than 10 years of occupational experience, however, no increase over controls could be ascertained in percentage of chromosomal damage. When radiation workers were re-distributed in accord with the exposures received, it was evident that the effect increased with the accumulated dose, the group with about 0.02 Sievert having nearly twice the aberrant cell percentage for the 0.01 Sievert group. In the group of up to 0.05 Sievert, the percentage of aberrant cells was in the order of that observed after exposure to 0.02 Sievert. From the findings in the analysis, radiation quality seemed to play no part in enliciting the cytogenetic response of peripheral lymphocytes. (A.B.)

  7. Increased frequency of micronucleated exfoliated cells among humans exposed in vivo to mobile telephone radiations

    International Nuclear Information System (INIS)

    Manoj Kumar Sharma; Abhay Singh Yadav

    2007-01-01

    Complete text of publication follows. The health concerns have been raised following the enormous increase in the use of wireless mobile telephones through out the world. This investigation had been taken, with the motive to find out whether mobile phone radiations cause any in vivo effects on the frequency of micronucleated exfoliated cells in the exposed subjects. A total of 109 subjects including 85 regular mobile phone users (exposed) and 24 non-users (controls) had participated in this study. Exfoliated cells were obtained by swabbing the buccal-mucosa from exposed as well as sex-age-matched controls. One thousand exfoliated cells were screened from each individual for nuclear anomalies including micronuclei (MN), karyolysis (KL), karyorrhexis (KH), broken egg (BE) and bi-nucleated (BN) cells. The average daily duration of exposure to mobile phone radiations is 61.26 minutes with an overall average duration of exposure in term of years is 2.35 years in exposed subjects along with the 9.84±0.745 MNC (micronucleated cells) and 10.72±0.889 TMN (total micronuclei) as compared to zero duration of exposure along with average 3.75±0.774 MNC and 4.00±0.808 TMN in controls. The means are significantly different in case MNC and TMN at 0.01% level of significance. For all other nuclear anomalies (KL, KH, BE and BN cells) the means are found statistically nonsignificant. A positive correlation was found in the frequency of MNC and TMN with respect to duration of exposure time.

  8. Follow-up of victim exposed in uterus 16 years after Xinzhou radiation accident

    International Nuclear Information System (INIS)

    Liang Li; Zhang Shulan; Jia Tingzhen; Liu Qingjie; Ma Liwen; Su Xu; Zhang Zhaohui; Qin Bin; Chen Sen; Wang Wenxue

    2010-01-01

    Objective: To observe and study the late effects of intrauterine exposure to irradiation. Methods: A 16-year-old girl, borne by a woman exposed to 60 Co irradiation during the Xinzhou radiation accident 16 years ago underwent inquiry, general medical examination. Conventional chromosome aberration analysis and fluorescence in situ hybridization (FISH) were used to examine non-stability and stability shromosome aberrations, and China revised Wechsler Intelligence Scale for Children (C W ISC) was used to detect IQ level. Results: Inquiry revealed no history of carcinoma and no family history of hereditary diseases. The girl often caught cold when she was a child, but she hadn't any other diseases. Menarche occurred when she was 12 years old, and she had not suffered from dysmenorrhea. Her development of body frame constitution was normal. She could not carry out addition and subtraction, but she could make simple verbal communication, writing and even reciting text. The results of the routine lab examination were within the normal range. Unstable chromosome aberrations were not shown, and the chromosome translocation rate was 2.3%. The dose that induced the chromosome injury was deduced as 0.81 Gy. The biological dose of the radiation that she was exposed to was inferred to be 1.85 Gy when she was in her mother's uterus. Ultrasonic sound showed nodular goiter and no malignant change. China's revised Wechsler Intelligence Scale for Children (C W ISC) test results showed that speech, operation and full-scale IQ was 51, 50, and 46 respectively. The total intelligence was better than 0.01%, and worse than 99.90% of the population. Conclusions: Exposure in utero does not affect the body frame constitution development after birth of the fetus, but mental retardation is clear. No evidence of any tumor can be found for the children exposed to radiation before their birth. (authors)

  9. mFISH analysis of chromosome aberrations in workers occupationally exposed to mixed radiation

    Energy Technology Data Exchange (ETDEWEB)

    Sotnik, Natalia V.; Osovets, Sergey V.; Azizova, Tamara V. [Southern Urals Biophysics Institute (SUBI), Ozyorsk, Chelyabinsk Region (Russian Federation); Scherthan, Harry [Bundeswehr Institute of Radiobiology Affiliated to the University of Ulm, Munich (Germany)

    2014-05-15

    We performed a study on the presence of chromosome aberrations in a cohort of plutonium workers of the Mayak production association (PA) with a mean age of 73.3 ± 7.2 years to see whether by multi-color fluorescence in situ hybridization (mFISH) translocation analysis can discriminate individuals who underwent occupational exposure with internal and/or external exposure to ionizing radiation 40 years ago. All Mayak PA workers were occupationally exposed to chronic internal alpha-radiation due to incorporated plutonium-239 and/or to external gamma-rays. First, we obtained the translocation yield in control individuals by mFISH to chromosome spreads of age-matched individuals and obtained background values that are similar to previously published values of an international study (Sigurdson et al. in Mutat Res 652:112-121, 2008). Workers who had absorbed a total dose of >0.5 Gy external gamma-rays to the red bone marrow (RBM) displayed a significantly higher frequency of stable chromosome aberrations relative to a group of workers exposed to <0.5 Gy gamma-rays total absorbed RBM dose. Thus, the translocation frequency may be considered to be a biological marker of external radiation exposure even years after the exposure. In a group of workers who were internally exposed and had incorporated plutonium-239 at a body burden >1.48 kBq, mFISH revealed a considerable number of cells with complex chromosomal rearrangements. Linear associations were observed for translocation yield with the absorbed RBM dose from external gamma-rays as well as for complex chromosomal rearrangements with the plutonium-239 body burden. (orig.)

  10. ECG changes in factory workers exposed to 27.2  MHz radiofrequency radiation.

    Science.gov (United States)

    Chen, Qingsong; Xu, Guoyong; Lang, Li; Yang, Aichu; Li, Shilin; Yang, Liwen; Li, Chaolin; Huang, Hanlin; Li, Tao

    2013-05-01

    To research the effect of 27.2 MHz radiofrequency radiation on electrocardiograms (ECG), 225 female workers operating radiofrequency machines at a shoe factory were chosen as the exposure group and 100 female workers without exposure from the same factory were selected as the control group. The 6 min electric field strength that the female workers were exposed to was 64.0 ± 25.2 V/m (mean ± SD), which exceeded 61 V/m, the International Commission on Non-Ionizing Radiation Protection reference root mean square levels for occupational exposure. A statistical difference was observed between the exposed group and the control group in terms of the rate of sinus bradycardia (χ(2)  = 11.48, P = 0.003). When several known risk factors for cardiovascular disease were considered, including smoking, age, alcohol ingestion habit, and so on, the exposure duration was not an effective factor for ECG changes, sinus arrhythmia, or sinus bradycardia according to α = 0.05, while P = 0.052 for sinus arrhythmia was very close to 0.05. We did not find any statistical difference in heart rate, duration of the QRS wave (ventricular depolarization), or corrected QT intervals (between the start of the Q wave and end of the T wave) between the exposed and control groups. Occupational exposure to radiofrequency radiation was not found to be a cause of ECG changes after consideration of the confounding factors. Copyright © 2012 Wiley Periodicals, Inc.

  11. Claudin-3 expression in radiation-exposed rat models: A potential marker for radiation-induced intestinal barrier failure

    Energy Technology Data Exchange (ETDEWEB)

    Shim, Sehwan; Lee, Jong-geol; Bae, Chang-hwan; Lee, Seung Bum [National Radiation Emergency Medical Center, Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of); Jang, Won-Suk; Lee, Sun-Joo [Laboratory of Experimental Pathology, Korea Cancer Center Hospital, Seoul (Korea, Republic of); Lee, Seung-Sook [National Radiation Emergency Medical Center, Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of); Department of Pathology, Korea Cancer Center Hospital, Seoul (Korea, Republic of); Park, Sunhoo, E-mail: sunhoo@kcch.re.kr [National Radiation Emergency Medical Center, Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of); Department of Pathology, Korea Cancer Center Hospital, Seoul (Korea, Republic of)

    2015-01-02

    Highlights: • Irradiation increased intestinal bacterial translocation, accompanied by claudin protein expression in rats. • Neurotensin decreased the bacterial translocation and restored claudin-3 expression. • Claudin-3 can be used as a marker in evaluating radiation induced intestinal injury. - Abstract: The molecular events leading to radiation-induced intestinal barrier failure are not well known. The influence of the expression of claudin proteins in the presence and absence of neurotensin was investigated in radiation-exposed rat intestinal epithelium. Wistar rats were randomly divided into control, irradiation, and irradiation + neurotensin groups, and bacterial translocation to the mesenteric lymph node and expression of claudins were determined. Irradiation led to intestinal barrier failure as demonstrated by significant bacterial translocation. In irradiated terminal ilea, expression of claudin-3 and claudin-4 was significantly decreased, and claudin-2 expression was increased. Administration of neurotensin significantly reduced bacterial translocation and restored the structure of the villi as seen by histologic examination. Among the three subtype of claudins, only claudin-3 expression was restored. These results suggest that the therapeutic effect of neurotensin on the disruption of the intestinal barrier is associated with claudin-3 alteration and that claudin-3 could be used as a marker in evaluating radiation-induced intestinal injury.

  12. The protective effect of lycopene against radiation injury to the small intestine of abdominally radiated mice

    International Nuclear Information System (INIS)

    Itoh, Youko; Kurabe, Teruhisa; Ishiguchi, Tsuneo

    2004-01-01

    To reduce the side effects of radiotherapy, radioprotective effects of lycopene on villi and crypts in the small intestine of abdominally radiated mice (15 Gy) were examined with administration pre-, continuous and post-radiation. In the lycopene group, the ratio of the villus length to the crypt was significantly increased in comparison with the radiation only group at 2 days after radiation. At 7 days after radiation, the ratio of necrotic cells in crypt/total was significantly decreased and the ratio of necrotic cells in villus/total was significantly increased by lycopene administration, which indicated an acceleration of the recovery from the radiation injury with lycopene. Each lycopene administered group showed a significant radioprotective effect, with the pre-radiation administration inducing a smaller effect than that of continuous and post-radiation administration. Radiation induced apoptosis was also decreased by lycopene administration. It is concluded that pre-, continuous and post-radiation administration of lycopene protects against radiation injury of the small intestine and accelerate the recovery. (author)

  13. Induction of λ prophage in lysogenic E.Coli exposed to ionizing radiation of different let

    International Nuclear Information System (INIS)

    Bonev, M.; Kozubek, S.; Krasavin, E.A.; Cherevatenko, A.P.

    1988-01-01

    Induction of λ prophage in lysogenic E. coli cells exposed to ionizing radiation of different LET was studied as a function of dose I(D). Activities of pleiotropic RecA protein were shown to contribute to the shape of the I(D) curve. The experimental data were fitted by the function I(D)=αD(1-exp(-D 0 -1 xD))exp(-βD). Inducibility α increased with increasing LET which was related to the increased incidence of DNA lesions being a SOS - system call

  14. Bacterial growth in humic waters exposed to UV-radiation and simulated sunlight

    DEFF Research Database (Denmark)

    Corin, N.; Backlund, P.; Wiklund, T.

    1998-01-01

    Sterile filtered (0.45 mu m) humic lake water was exposed to simulated sunlight (300-800 nm) or W-radiation (254 run)for various periods of times and the dissolved organic carbon content, absorbance at 254 and 460 nm and PH were recorded. The irradiated water was inoculated with a natural bacterial...... assemblage and the number of viable bacteria war estimated 3 and 5 days after the inoculation using the plate count technique. The number of viable bacteria increased with the irradiation time indicating that the chemical changes of the humus macromolecules observed during irradiation resulted...

  15. Cytogenetic monitoring, radiosensitivity study and adaptive response of workers exposed to low level ionizing radiation

    International Nuclear Information System (INIS)

    Peitl Junior, Paulo

    1996-01-01

    The objectives of the present study were: To determine the frequencies of chromosome aberrations in lymphocytes from individuals belonging to professionally exposed groups, under normal conditions; to determine the possible differences in radiosensitivity between the lymphocytes of technicians and controls after in vitro irradiation with gamma rays during the G 1 phase of the cell cycle (radiosensitivity study), and to examine the influence of in vivo and in vitro pre-exposure to low doses of radiation on the frequency of chromosome aberrations induced in vitro by high doses (study of the adaptive response) in a group of technicians (T) compared to controls (C). (author)

  16. Peculiarities of gastrointestinal tract diseases course in the persons exposed to ionizing radiation

    International Nuclear Information System (INIS)

    Pasyijeshvyilyi, L.M.

    1994-01-01

    The study involved 145 men aged 21 - 49 years, who were exposed to radiation in the dose of 9.3 ± 1.6 rem at different terms of their stay in 30-km zone during 49 ± 5.4 days. In the study group, chronic gastroduodenitis was diagnosed in 56 patients, chronic cholecystitis - in 47 patients, chronic pancreatitis - in 42 patients. In spite of the difference of nosologic forms, main clinical features of the disease were noted to be the changes of vegetative nervous system and psycho emotional changes

  17. Morphofunctional lesions in kidneys of monkeys pretreated with drugs and exposed to proton radiation

    International Nuclear Information System (INIS)

    Fedorenko, B.S.; Kabachenko, A.N.; Smirnova, O.A.

    1980-01-01

    A study was made of the effect of adeturon or complex treatment on the development of structural derangements, the volume of renal glomeruli and Bowman's capsules in kidneys of monkeys exposed to 240 MeV protons in a dosage of 700 rad. Injection or adeturon (100 mg/kg) 15 min before irradiation, or treatment with antibiotics and vitamins fail to lower the degree of morphological damage to kidneys. It is assumed that processes of autosensitization in the irradiated animal organism play an important role in the development of radiation injury to kidneys

  18. Health surveillance of medical personnel occupationally exposed to ionizing radiation sources: Biomonitoring and dosimetry

    International Nuclear Information System (INIS)

    Brumen, V.; Prlic, I.; Radalj, Z.; Horvat, D.; Cerovac, H.

    1996-01-01

    The aim of this work is to present the complete results of periodical health surveillance of medical personnel occupationally exposed to ionizing radiation sources, conducted according to established law regulations in Croatia. The report comprises a total of 21 examinees (11 female, 10 male), mean age 43,19 ± 9,85 years, originating from different professional groups and working in a radiation zone 14,7 ± 8,27 years on the average. Within the framework of this study, the results of their biomonitoring, including haematological parameters (whole blood count), ophthalmological findings (fundus oculi), cytogenetic test (conventional structural chromosomal aberration analysis) and peripheral blood flow survey (capillaroscopy and dermothermometry) will be presented. Filmdosimetric data for the referred period will also be reported. (author)

  19. Haematological evaluation in workers exposed to ionizing radiation from a radiotherapy service

    International Nuclear Information System (INIS)

    Lopez Pumar, G.M.; Frometa Suarez, I.

    1997-01-01

    Evaluation of haematological indicators is carried out as routing in medical surveillance of workers exposed to ionizing radiation, in order to assest the initial and continuing fitness for their intended tasks. The purpose of this work is to analize the behaviour of haematological parametsrs in relation with the time of exposure as well as received doses for workers. It was stabilished a 8 years follw up for the 74 workers of the radiotherapy service in the Oncological Hospital in Havana City. As result were observed no significant changes on mean number of leucocytes, platelets an haemoglobin, which oscillate within normal limits stablished for adult people. Allthought it was incountered an increase in the number of cases with leucopenia, in direct relation with the increase of time of exposure an cumulative doses. The incidence of those cases was 2,3 times higher in the 8th year of the follow up, in relation with the begining of the exposition to ionizing radiation

  20. Liver polyribosome distribution in intact and adrenalectomized rats exposed to. gamma. radiation

    Energy Technology Data Exchange (ETDEWEB)

    Yatvin, M B; Abdel-Halim, M N [Wisconsin Univ., Madison (USA). Dept. of Radiology; Wisconsin Univ., Madison (USA). Dept. of Human Oncology)

    1978-06-01

    The mechanism(s) by which gamma radiation influences liver polyribosome distribution was studied in groups of intact and adrenalectomized male rats. A shift from light to heavy aggregates occurred in the polyribosomes of both intact and adrenalectomized rats after they were exposed to gamma rays. In irradiated adrenalectomized rats, however, the shift to heavier aggregates was not as great as that which occurred in irradiated adrenal-intact animals. Subcutaneous injection of cortisone acetate (10 mg/100 g body weight) also altered the liver polyribosome patterns of both intact and adrenalectomized rats within 8 hours of its administration. The shift which occurred following cortisone administration, however, was less striking than that seen after irradiation only. Thus, although adrenal glucocorticoids contribute to the radiation-indu ied shift in liver polyribosomes in adrenal-intact rats, other factors appear to be involved, since the shift is also obtained in adrenalectomized animals.

  1. Global micro RNA expression in papillary thyroid carcinomas of young patients exposed to radiation

    Energy Technology Data Exchange (ETDEWEB)

    Unger, K.; Elmahjoub, A.; Thomas, G. [Human Cancer Studies Group, Surgery and Cancer, Imperial College London, London (United Kingdom); Bogdanova, T. [Institute of Endocrinology and Metabolism, Academy of Medical Sciences of the Ukraine, Kiew (Ukraine)

    2012-07-01

    One of the main effects of the Chernobyl reactor accident is an increase in childhood papillary thyroid carcinomas (PTC) in the regions that were contaminated with radio-iodine from the fallout. Despite a considerable research effort, molecular profiles have yet to be identified that reliably distinguish between age matched patients with radiation associated and sporadic PTCs. Expression of micro RNAs (miRNA) have recently been studied extensively in many different cancer types. MiRNAs have the potential to provide insights into the network of molecular pathways that are involved in the development of tumorigenesis as they are involved in the regulation of networks of mRNAs. In addition, miRNAs can be studied in formalin-fixed paraffin embedded material, making them ideal for clinical studies. This study was designed specifically to identify differentially expressed miRNAs in patients with childhood PTC that were exposed (n=11) and non-exposed (n=9) to irradiation. The results suggest that in radiation-associated childhood PTC DNA repair processes which are reflected by genes that encode DNA-binding proteins are de-regulated. DNA mutation and double-strand breaks are induced by ionising radiation and subsequent mis-repair and inactivation of tumour suppressor genes and the activation of oncogenes leads to growth and proliferation of the tumour cell. These findings suggest that in addition to the MAP kinase pathway which is known to be a key pathway in PTC, additional pathways such as the Fc epsilon RI signalling, the VEGF pathway and p53 signalling pathway seem to be involved in radiation-associated tumorigenesis of PTC

  2. First assessment of individual monitoring of medical workers occupationally exposed to ionizing radiation in Burkina Faso

    International Nuclear Information System (INIS)

    Yakoro, A.; Nobila Ouédraogo, Salimata Traoré

    2010-01-01

    This paper reports the results of monitoring of medical workers occupationally exposed to ionizing radiation as a consequence of exposure to X-rays, from 2007 to 2010, in Burkina Faso. The radiation exposure monitoring was made with thermoluminescent dosimeters (TLD-100) type 0110 and the reader used was Harshaw 4500. The medical establishments. subscribers were provided with personal dosimeters (measuring Hp (10) and Hp (0.07)) and dosimeters for background and workplace exposure (H*10) measurement. The dosimeters have been worn for periods of 2 months each. The number of establishments subscribed and workers monitored has gradually increased from 4 radiology establishments with 13 workers monitored at September 2007 to 23 subscribers with 121 workers monitored at the end of April 2010. 13 establishments were still working without monitoring. From September 2007 to April 2010, no individual annual dose limit has really been reached. 88.16% of the 2 months dose values of personal dosimeters were below 0.1mSv, the detection limit and 96.61% of Hp (10) bimonthly values were below 3.33mSv. The workplace exposure monitoring values were often low (varying from 0.00mSv to 40.45mSv). 87.08% of the values of H*(10) were below 3.33mSv, the upper limit of Hp (10) for a period of 2 months. Low values of individual dose have also been recorded despite of high values of workplace monitoring. This allowed to state that the workers monitored were not exposed to a major risk. Nevertheless, 13 TLD have been lost and 3 damaged by subscribers (out of 1504 TLD provided). 26 times (out of 240), background measurement and workplace exposure monitoring dosimeters have been placed at the improper location. Therefore, sensitization of the establishments using ionizing radiation should be reinforced and the national regulations should impose radiation monitoring (author)

  3. Global micro RNA expression in papillary thyroid carcinomas of young patients exposed to radiation

    International Nuclear Information System (INIS)

    Unger, K.; Elmahjoub, A.; Thomas, G.; Bogdanova, T.

    2012-01-01

    One of the main effects of the Chernobyl reactor accident is an increase in childhood papillary thyroid carcinomas (PTC) in the regions that were contaminated with radio-iodine from the fallout. Despite a considerable research effort, molecular profiles have yet to be identified that reliably distinguish between age matched patients with radiation associated and sporadic PTCs. Expression of micro RNAs (miRNA) have recently been studied extensively in many different cancer types. MiRNAs have the potential to provide insights into the network of molecular pathways that are involved in the development of tumorigenesis as they are involved in the regulation of networks of mRNAs. In addition, miRNAs can be studied in formalin-fixed paraffin embedded material, making them ideal for clinical studies. This study was designed specifically to identify differentially expressed miRNAs in patients with childhood PTC that were exposed (n=11) and non-exposed (n=9) to irradiation. The results suggest that in radiation-associated childhood PTC DNA repair processes which are reflected by genes that encode DNA-binding proteins are de-regulated. DNA mutation and double-strand breaks are induced by ionising radiation and subsequent mis-repair and inactivation of tumour suppressor genes and the activation of oncogenes leads to growth and proliferation of the tumour cell. These findings suggest that in addition to the MAP kinase pathway which is known to be a key pathway in PTC, additional pathways such as the Fc epsilon RI signalling, the VEGF pathway and p53 signalling pathway seem to be involved in radiation-associated tumorigenesis of PTC

  4. Combination chemotherapy concurrent with small dose radiation therapy for small cell carcinoma of the lung

    International Nuclear Information System (INIS)

    Tada, Toshihiko; Fujita, Hiroji; Shintomi, Takenori

    1987-01-01

    Forty consecutive patients with small cell carcinoma of the lung were treated with chemotherapy, radiotherapy or both. Of 34 patients treated with chemotherapy, 24 were treated with combination chemotherapy, containing cyclophosphamide vincristine methotrexate and procarbazine, concurrent with small dose radiation therapy (500 cGy/5 fraction) as a chemosensitizer (COMPrt). The response rate to this regimen was 81 % (29 % complete) and the 2 year survival rate was 28.6 %. These results have been superior to other regimens and the toxicity was not see to be any higher. After completion of COMPrt regimen, 10 patients were treated with intrathoracic radiation therapy (average dose 3000 cGy) and 3 recieved surgical treatment. Radiation therapy improved the 2-year survival rate (42.2 %) when compared with those patients who received no radiation therapy (18.2 %). Three patients received surgical treatment were considered to be disease-free for 23, 17, and 9 months respectively, after induction of chemotherapy. (author)

  5. Report of the actual conditions of the radiation exposed residents near the former Semipalatinsk nuclear test site

    International Nuclear Information System (INIS)

    Kawano, Noriyuki; Taooka, Yasuyuki; Hiraoka, Takashi; Hoshi, Masaharu; Shaimardanovich, Z.Z.

    2004-01-01

    Hiroshima Peace Science Consortium, established in 2002 as part of the local cooperation project of Hiroshima University for peace science, conducted a field research in Semipalatinsk and related areas in 2002 to collect and analyze data on health effects of radiation experiences of people exposed to nuclear test radiation. This book is a report of the research and contains Introductory remarks; 6 chapters of Overview of the study, Medical information analysis on the radiation exposed residents near the former Semipalatinsk nuclear test site using questionnaire, Content analysis of testimonies written by hibakusha near the nuclear test site of Semipalatinsk, Comments on the interview, Significance of collecting testimonies of those exposed to radiation in Semipalatinsk, Kazakhstan/in comparison with those of Hiroshima and Nagasaki, and Future tasks and prospective; Conclusion; and 2 Appendices of Research on the conditions of radiation exposure survey response sheet and Testimonies. (N.I.)

  6. The problematic on the cancer development in occupationally exposed workers to ionizing radiations

    International Nuclear Information System (INIS)

    Nouailhetas, Y.; Mezrahi, A.; Heilbron Filho, P.F.L.; Oliveira, S.M.V.

    1996-01-01

    Frequently and in an increasing perspective, the Brazilian Nuclear Energy Commission is inquired on the development of cancer in occupationally exposed workers to ionizing radiation. These workers try to compensate their state of ill health juridically. Taking into account that cancer is a probabilistic effect of radiation, it could be only detected by an increase in cases that normally occur in a particular population. Whether or not the occurrence of the illness is identified as having occupational origin misses scientific consistence. Regarding the probabilistic effect of low level radiation doses, radiation protection is founded on the linear dose-effect without threshold hypothesis. Thus, it could be call into a question: is it possible that the illness, presented by an individual, derives from occupational causes. If the answer is positive, the responsibility can be imputed, at first, to the employer and the link of causality turns out to be fundamented not any more in measurable objective facts but in social, economic, ethic and moral aspects, which arise from the radiological protection quality and measures offered by the employer. (author)

  7. Radiation-use of a forest exposed to elevated concentrations of atmospheric carbon dioxide

    International Nuclear Information System (INIS)

    DeLucia, E. H.; George, K.; Hamilton, J. G.

    2002-01-01

    Radiation-use efficiency of growth (defined as biomass accumulation per unit of absorbed photosynthetically active radiation) of loblobby pine forest plots exposed to ambient or elevated atmospheric carbon dioxide concentration was compared. Biomass accumulation of the dominant loblobby pines was calculated from monthly measurements of tree growth and site-specific allometric measurements. Leaf area index was estimated by optical, allometric and interfall methods, depending on species. Results showed that depending on tree height, elevated carbon dioxide did not alter the above-ground biomass allocation in loblobby pine. Leaf area index estimates by the different methods were found to vary significantly, but elevated carbon dioxide had only a slight effect on leaf area index in the first three years of this study. The 27 per cent increase in radiation-use efficiency of growth in response to carbon dioxide enrichment is believed to have been caused primarily by the stimulation of biomass increment. It was concluded that long-term increases in atmospheric carbon dioxide concentration can increase the radiation-use efficiency of growth in closed canopy forests, but the magnitude and duration of this increase in uncertain. 57 refs., 2 tabs., 3 figs

  8. Role of Immunomodulators in Tumor Regression in Mice Exposed to Fractionated Low Dose of Gamma Radiation

    International Nuclear Information System (INIS)

    Rokaya Elsayed Maaroaf Elsayed

    2015-01-01

    Immunotherapy is one of the most promising approaches of cancer treatment. The present study was designed to examine the role of irradiated tumor cell lysate vaccine, IFNα-2b and low dose of gamma irradiation as immunomodulators either alone or combined in tumor regression. Ehrlich ascite carcinoma (EAC) cells and 9 groups of female mice were used. Mice were immunized intramuscularly by tumor cell lysate vaccine one time/week for 3 weeks in the right thigh of mice. After two weeks from last immunization, all mice were challenged with normal viable EAC cells at count of 2.5 ×10 6 /mouse in the opposite left thigh for Ehrlich carcinoma (EC) production. Mice were subcutaneously injected with 10.000 units of IFNα-2b 3 times/week for 4 weeks and others were exposed to fractionated dose of γ- radiation (0.5 Gy/day x 4, day after day). Tumor size, serum tumor markers (TNF-α and CEA), tumor DNA fragmentation and Caspase-3 were evaluated. Oxidative stress (MDA and NO) markers and antioxidants (GSH, GPX and SOD) were determined in spleen and tumor tissues. Histopathological examinations, apoptosis and necrosis in spleen and tumor tissues were also examined. The results revealed significant inhibition in tumor size throughout the observation period either for treatments with vaccine or IFNα-2b either alone or combined with γ-irradiation. DNA fragmentation and Caspase-3 enzyme activities were significantly elevated in immunized mice as compared with EC group along with diminished tumor size while, tumor markers were significantly decreased. MDA and NO were significantly increased in tumor tissue.while, tumor GSH content, GPX and SOD activities were significantly decreased. Combined treatments of female mice bearing EC with IFN-α-2b, tumor cell lysate vaccine and low dose of γ-radiation cause a highly significant decrease in serum TNF-α and CEA levels, increase in Cas-3 activity, no DNA fragmentation, significant increase in MDA, decrease in SOD activity and decreased

  9. Chromosome aberrations in peripheral blood lymphocytes in subjects occupationally exposed to ionizing radiation or chemical clastogens

    International Nuclear Information System (INIS)

    Lalic, H.; Radosevic-Stasic, B.

    2002-01-01

    To get an insight into genotoxic risk in some occupations, in this study the chromosome aberration analysis of peripheral blood lymphocytes was made in 20 physicians and nurses exposed to a low dose of ionizing radiation in a hospital, 12 individuals working with X-rays in a cement factory and 19 technicians working with some chemical toxic agents in the laboratories of a medical school. The control group consisted of 14 sex- and age-matched unexposed persons living in the same district area. The data showed that the total number of chromosome aberrations in 200 scored metaphases in all examined groups were almost the same and inside the low-permitted values. In hospital workers, however, the percentage of acentric and dicentric fragments (1.63 ± 0.28 vs 0.31 ± 0.21 and 0.47 ± 0.18 vs 0.0, respectively) increased predominantly in contrast to cement-factory employees and laboratory workers, where a higher incidence of minutes (0.58 ± 0.19 vs 0.31 ± 0.2) or gaps (2.21 ± 0.37 vs 1.15 ± 1.15) was noticed. Moreover, in groups exposed to low doses of ionizing radiation (hospital and factory), a positive correlation was found between the total number of chromosome aberrations and the 6-year absorption dose or working period, suggesting an effect of cumulative dosage. (author)

  10. Hot spring therapy of the patients exposed to atomic bomb radiation, 15

    Energy Technology Data Exchange (ETDEWEB)

    Ouchi, Tamon [Genbaku Hibakusha Beppu Onsen Ryoyo Kenkyusho, Oita (Japan); Tsuji, Hideo

    1983-03-01

    The patients exposed to the atomic bomb radiation in Hiroshima area came to Beppu Spa to have hot spring therapy. During the fiscal year of 1982 (April, 1982, to March, 1983), 3972 persons came to the hot spring sanatorium, and 586 patients (14.8 %) received physical examination. Among them, 473 patients (80.7 %) were exposed to the atomic bomb radiation on August 6, 1945, or entered in the city of Hiroshima by August 20, 1945, according to the official notebook issued by the government. Physical examination was performed twice a week during their stay, and more than 53.5 % of the patients were older than 70, and the oldest was 93 years old. Blood pressure was measured when the patients came in and went out, and hypertensive patients were asked to observe the rule of treatment strictly. The complaints of the patients which brought them to the hot spring were mostly pain in bodies and lower extremities, and hypertension, common cold syndrome, diabetes and constipation. Patients took hot spring bath 2

  11. Molecular Characterization of TP53 Gene in Human Populations Exposed to Low-Dose Ionizing Radiation

    Directory of Open Access Journals (Sweden)

    Igor Brasil-Costa

    2013-01-01

    Full Text Available Ionizing radiation, such as that emitted by uranium, may cause mutations and consequently lead to neoplasia in human cells. The TP53 gene acts to maintain genomic integrity and constitutes an important biomarker of susceptibility. The present study investigated the main alterations observed in exons 4, 5, 6, 7, and 8 of the TP53 gene and adjacent introns in Amazonian populations exposed to radioactivity. Samples were collected from 163 individuals. Occurrence of the following alterations was observed: (i a missense exchange in exon 4 (Arg72Pro; (ii 2 synonymous exchanges, 1 in exon 5 (His179His, and another in exon 6 (Arg213Arg; (iii 4 intronic exchanges, 3 in intron 7 (C → T at position 13.436; C → T at position 13.491; T → G at position 13.511 and 1 in intron 8 (T → G at position 13.958. Alteration of codon 72 was found to be an important risk factor for cancer development (P=0.024; OR=6.48; CI: 1.29–32.64 when adjusted for age and smoking. Thus, TP53 gene may be an important biomarker for carcinogenesis susceptibility in human populations exposed to ionizing radiation.

  12. Hot spring therapy of the patients exposed to atomic bomb radiation, 15

    International Nuclear Information System (INIS)

    Ouchi, Tamon; Tsuji, Hideo.

    1983-01-01

    The patients exposed to the atomic bomb radiation in Hiroshima area came to Beppu Spa to have hot spring therapy. During the fiscal year of 1982 (April, 1982, to March, 1983), 3972 persons came to the hot spring sanatorium, and 586 patients (14.8 %) received physical examination. Among them, 473 patients (80.7 %) were exposed to the atomic bomb radiation on August 6, 1945, or entered in the city of Hiroshima by August 20, 1945, according to the official notebook issued by the government. Physical examination was performed twice a week during their stay, and more than 53.5 % of the patients were older than 70, and the oldest was 93 years old. Blood pressure was measured when the patients came in and went out, and hypertensive patients were asked to observe the rule of treatment strictly. The complaints of the patients which brought them to the hot spring were mostly pain in bodies and lower extremities, and hypertension, common cold syndrome, diabetes and constipation. Patients took hot spring bath 2 - 3 times daily, and many patients had microwave and low frequency wave treatment. Soaking in a bath (containing 1.4 mg of cupric sulfate and 11.4 mg of zinc sulfate per liter) was practiced by diabetic patients. The therapeutic effects were difficult to judge because the period of stay of the most patients was about 10 days, but in most of them, subjective symptoms were relieved when they left the sanatorium. (Yamashita, S.)

  13. Determination of intake and internal radiation dose for occupationally exposed workers to iodine 131

    International Nuclear Information System (INIS)

    Kharita, M. H.; Maghrabi, M.; Sadyya, A.

    2004-12-01

    Workers who prepare and inject radioactive Iodine I 131 doses at the medical centers in Syria are potentially exposed to the radioactive intake by ingestion or inhalation during preparation or injection processes. The received amount of the radioactive intake differs according to the amount of the I 131 that released during the preparation or injection processes, and to the work conditions and the applying ways of the radiation protection principles. Because of this radioactive intake, the thyroid gland may expose to amounts of I 131 which may negatively affect the health of the workers, so it is necessary to make routine monitoring for all workers who receive an intake of more than 10% of the annual intake limit which is (2*10 6 Bq/y) for I 131 . To make this monitoring process, it is necessary to use either the thyroid gland counter in order to know the concentrated amount of the radioactivity in the gland, or the analysis of a 24 hours urine sample of the exposed workers to determine the eliminated amount of the radioactivity using gamma spectrometry, also the two processes can be applied at the same time. Since the thyroid gland counter is not available, the analysis of urine sample was done to determine the concentrated amount of the radioactivity in urine, then to estimate the radioactive intake and the internal radioactive dose. The results of applying this method dictated that some workers work in safe conditions according to the radiation protection and there is no need for them to make routine monitoring . But the other workers receive a radioactive intake of about 10% yearly of the annual intake limit and that requires a routine periodical monitoring for those workers in addition to the necessity of applying the principles of the radiation protection during the work with I 131 . These principles and systems should indicate the basic requirement of radiation protection that must be available in the laboratory that deal with I 131 either for therapy or for

  14. Depression, suicide ideation, and thyroid tumors among ukrainian adolescents exposed as children to chernobyl radiation.

    Science.gov (United States)

    Contis, George; Foley, Thomas P

    2015-05-01

    The Chernobyl Childhood Illness Program (CCIP) was a humanitarian assistance effort funded by the United States Congress. Its purpose was to assist the Ukrainian Government to identify and treat adolescents who developed mental and physical problems following their exposure as young children to Chernobyl radiation. Thirteen years after the Chernobyl nuclear plant accident in 1986, the CCIP examined 116,655 Ukrainian adolescents for thyroid diseases. Of these, 115,191 were also screened for depression, suicide ideation, and psychological problems. The adolescents lived in five of Ukraine's seven most Chernobyl radiation contaminated provinces. They were up to 6 years of age or in utero when exposed to nuclear fallout, or were born up to 45 months after Chernobyl. Ukrainian endocrinologist and ultrasonographers used physical examination and ultrasonography of the neck to evaluate the adolescents for thyroid tumors. The adolescents were then screened for depression by the Children's Depression Inventory (CDI). After this, Ukrainian psychologists conducted individual psychological interviews to corroborate the adolescents' CDI responses. Papillary thyroid carcinoma was diagnosed in eight adolescents, a high prevalence rate similar to that reported by other studies from the Soviet Union. Screening identified thyroid nodules in 1,967 adolescents (1.7%). Depression was diagnosed in 15,399 adolescents (13.2%), suicide ideation in 813 (5.3%), and attempted suicide in 354 (2.3%). Underlying components of the participants' depression were negative mood, interpersonal difficulties, negative self-esteem, ineffectiveness, and anhedonia. Depression was greater in females (77%). Those with thyroid and psychological problems were referred for treatment. The adolescents screened by CCIP represent the largest Ukrainian cohort exposed to Chernobyl radiation as children who were evaluated for both thyroid tumors and depression. The group had an increased prevalence of thyroid cancer

  15. NMR-based Metabolomics Analysis of Liver from C57BL/6 Mouse Exposed to Ionizing Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, Xiongjie [Pacific Northwest National Laboratory, Richland, Washington 99352; State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, the Chinese Academy of Sciences, Wuhan, 430071, PR China; University of Chinese Academy of Sciences, Beijing 100049, China; Hu, Mary [Pacific Northwest National Laboratory, Richland, Washington 99352; Zhang, Xu [State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, the Chinese Academy of Sciences, Wuhan, 430071, PR China; Hu, Jian Zhi [Pacific Northwest National Laboratory, Richland, Washington 99352

    2017-07-01

    The health effects of exposing to ionizing radiation are attracting great interest in the space exploration community and patients considering radiotherapy. However, the impact to metabolism after exposure to high dose radiation has not yet been clearly defined in livers. In the present study, 1H nuclear magnetic resonance (NMR) based metabolomics combined with multivariate data analysis are applied to study the changes of metabolism in the liver of C57BL/6 mouse after whole body exposure to either gamma (3.0 and 7.8 Gy) or proton (3.0 Gy) radiation. Principal component analysis (PCA) and orthogonal projection to latent structures analysis (OPLS) are employed for classification and identification of potential biomarkers associated with gamma and proton irradiation. The results show that the radiation exposed groups can be well separated from the control group. At the same radiation dosage, the group exposed to proton radiation is well separated from the group exposed to gamma radiation, indicating different radiation sources induce different alterations based on metabolic profiling. Common to both gamma and proton radiation at the high radiation doses studied in this work, compared with the control groups the concentrations of choline, O-phosphocholine and trimethylamine N-oxide are decreased statistically, while those of glutamine, glutathione, malate, creatinine, phosphate, betaine and 4-hydroxyphenylacetate are statistically and significantly elevated after exposure to radiation. Since these altered metabolites are associated with multiple biological pathways, the changes suggest that the exposure to radiation induce abnormality in multiple biological pathways. In particular, metabolites such as 4-hydroxyphenylacetate, betaine, glutamine, choline and trimethylamine N-oxide may be good candidates of pre-diagnose biomarkers for ionizing radiation in liver.

  16. Genetic effects in children exposed in prenatal period to ionizing radiation after the Chornobyl nuclear power plant accident.

    Science.gov (United States)

    Stepanova, Ye I; Vdovenko, V Yu; Misharina, Zh A; Kolos, V I; Mischenko, L P

    2016-12-01

    To study the genetic effects in children exposed to radiation in utero as a result of the Chornobyl nuclear power plant accident accounting the total radiation doses and equivalent radiation doses to the red bone marrow. Incidence of minor developmental anomalies was studied in children exposed to radiation in utero (study group) and in the control group (1144 subjects surveyed in total). Cytogenetic tests using the method of differential G-banding of chromosomes were conducted in 60 children of both study and control groups (10-12-year-olds) and repeatedly in 39 adolescents (15-17-year-olds). A direct correlation was found between the number of minor developmental anomalies and fetal dose of radiation, and a reverse one with fetal gestational age at the time of radiation exposure. Incidence of chromosomal damage in somatic cells of 10-12-year-old children exposed prenatally was associated with radiation dose to the red bone marrow. The repeated testing has revealed that an increased level of chromosomal aberrations was preserved in a third of adolescents. The persons exposed to ionizing radiation at prenatal period should be attributed to the group of carcinogenic risk due to persisting increased levels of chromosome damage. This article is a part of a Special Issue entitled "The Chornobyl Nuclear Accident: Thirty Years After".

  17. The efficiency of superficially active compounds on the process of decontamination in animals exposed to various doses of ionizing radiation

    International Nuclear Information System (INIS)

    Kossakowski, S.

    1977-01-01

    The efficiency of some superficially active compounds on the process of decontamination was investigated in swine exposed to various doses of ionizing radiation (300, 600 R), and then contaminated with 90 Sr, 131 I, 137 Cs, and 144 Ce. The results revealed that the time factor after irradiation was more important for the efficiency of decontamination than the doses of radiation. (author)

  18. Prediction of radiation-related small-bowel damage

    International Nuclear Information System (INIS)

    Potish, R.A.

    1980-01-01

    In order to predict which patients have a high risk for radiation-related small-bowel damage, the concept of the dose-response curve was applied to the predisposing factors (number of previous laparotomies, extent of surgery, thin physique, hypertension, age, cancer stage, number of treatment days, fractionation, and weight change during radiotherapy) present in 92 patients receiving identical radiation doses and volumes This analysis allows an estimate of the probability of complication to be assigned to individual patients. The utility and limitations of the dose-response concept are discussed

  19. Dose-rate effects for mammary tumor development in female Sprague-Dawley rats exposed to X and γ radiation

    International Nuclear Information System (INIS)

    Johnson, J.R.; Gragtmans, N.J.; Myers, D.K.; Jones, A.R.

    1989-01-01

    Mammary tumour development was followed in two experiments involving a total of 2229 female Sprague-Dawley rats exposed to various doses of X or γ rays at different dose rates. The data for another 462 rats exposed to tritiated water in one of these experiments were also analyzed. The incidence of adenocarcinomas and fibroadenomas at a given time after exposure increased linearly in proportion to total radiation dose for most groups. However, no significant increase in adenocarcinomas was observed with chronic γ exposures up to 1.1 Gy, and the increase in fibroadenomas observed with chronic gamma exposures at a dose rate of 0.0076 Gy h -1 up to an accumulated dose of 3.3 Gy was small compared to that observed after acute exposures. The incidence of all mammary tumors increased almost linearly with the log of dose rate in the range 0.0076 to 26.3 Gy h -1 for 3 Gy total dose of gamma rays. The effects of X rays appeared to be less influenced by dose rate than were the effects of γ rays. (author)

  20. Leukaemia following childhood radiation exposure in the Japanese atomic bomb survivors and in medically exposed groups

    International Nuclear Information System (INIS)

    Little, M. P.

    2008-01-01

    Incidence and mortality risks of radiation-associated leukaemia are surveyed in the Japanese atomic bomb (A-bomb) survivors exposed in early childhood and in utero. Leukaemia incidence and mortality risks are also surveyed in 16 other studies of persons who received appreciable doses of ionizing radiation in the course of treatment in childhood and for whom there is adequate dosimetry and cancer incidence or mortality follow-up. Relative risks tend to be lower in the medical series than in the Japanese A-bomb survivors. The relative risks in the medical studies tend to diminish with increasing average therapy dose. After taking account of cell sterilisation and dose fractionation, the apparent differences between the relative risks for leukaemia in the Japanese A-bomb survivors and in the medical series largely disappear. This suggests that cell sterilisation largely accounts for the discrepancy between the relative risks in the Japanese data and the medical studies. Excess absolute risk has also been assessed in four studies, and there is found to be more variability in this measure than in excess relative risk. In particular, there is a substantial difference between the absolute risk in the Japanese atomic bomb survivor data and those in three other (European) populations. In summary, the relative risks of leukaemia in studies of persons exposed to appreciable doses of ionizing radiation in the course of treatment for a variety of malignant and non-malignant conditions in childhood are generally less than those in the Japanese A-bomb survivor data. The effects of cell sterilisation can largely explain the discrepancy between the Japanese and the medical series. (authors)

  1. Toxicity bioassay in mice exposed to low dose-rate radiation

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Joog Sun; Gong, Eun Ji; Heo, Kyu; Yang, Kwang Mo [Research Center, Dongnam Institute of Radiological and Medical Sciences, Busan (Korea, Republic of)

    2013-04-15

    The systemic effect of radiation increases in proportion to the dose amount and rate. The association between accumulated radiation dose and adverse effects, which is derived according to continuous low dose-rate radiation exposure, is not clearly elucidated. Our previous study showed that low dose-rate radiation exposure did not cause adverse effects in BALB/c mice at dose levels of ≤2 Gy, but the testis weight decreased at a dose of 2 Gy. In this study, we studied the effects of irradiation at the low dose rate (3.49 mGy/h) in the testes of C57BL/6 mice. Mice exposed to a total dose of 0.02, 0.2, and 2 Gy were found to be healthy and did not show any significant changes in body weight and peripheral blood components. However, mice irradiated with a dose of 2 Gy had significantly decreased testis weight. Further, histological studies and sperm evaluation also demonstrated changes consistent with the findings of decreased testis weight. In fertile patients found to have arrest of sperm maturation, the seminiferous tubules lack the DNMT1 and HDAC1 protein. The decrease of DNMT1 and HDAC1 in irradiated testis may be the part of the mechanism via which low dose-rate irradiation results in teticular injury. In conclusion, despite a low dose-rate radiation, our study found that when mice testis were irradiated with 2 Gy at 3.49 mGy/h dose rate, there was significant testicular and sperm damage with decreased DNMT1 and HDAC1 expression.

  2. Risk of cancer among in utero children exposed to A-bomb radiation, 1950-84

    International Nuclear Information System (INIS)

    Yoshimoto, Yasuhiko; Kato, Hiroo; Schull, W.J.

    1990-01-01

    This study examines the risk of cancer (incidence) over a period of 40 years among the inutero exposed survivors of the atomic bombing of Hiroshima and Nagasaki, and adds eight years of follow-up to a previous report which was confined to mortality. Only two cases of childhood cancer were observed among these survivors in the first 14 years of life; both had been heavily exposed. Subsequent cancers have all been of the adult type. Not only did the observed cancers occur earlier in the ≥ 0.30 Gy dose group than in the 0 Gy dose group but the incidence continues to increase and the crude cumulative incidence rate, 40 years after the A-bombing, is 3.9-fold greater in the ≥ 0.30 Gy group. In the observation period 1950-84, based on the absorbed dose to the mother's uterus, as estimated by the Dosimetry System 1986 (DS86), the relative risk of cancer at 1 Gy is 3.77 with a 95% confidence interval of 1.14-13.48. For the entire ≥ 0.01 Gy dose group the average excess risk per 10 4 person-year-gray is 6.57 (0.07-14.49) and the estimated attributable risk is 40.9% (2.9%-90.2%). These results, when viewed in the perspective of fetus doses, suggest that susceptibility to radiation-induced cancers is higher in pre- than in postnatally exposed survivors (at least those exposed as adults). However, definitive conclusions must await further follow-up studies. (author)

  3. Epidemiological studies of general population groups exposed to low-level radiation

    International Nuclear Information System (INIS)

    Davies, J.M.; Inskip, H.

    1986-01-01

    The exposure of man to radiation and the resulting risk of carcinogenesis continue to be of concern to the public. In this context, there is often a tendency to carry out epidemiological studies concerning the induction of cancer in radiation workers and members of the public which are not supported by a statistically valid data base or whose result are misinterpreted or misused. To assist national authorities in evaluating radiological risks, the Nuclear Energy Agency has sponsored a critical review of the methodologies for, and the limitations of, these epidemiological studies, and of the precautions to be adopted in interpreting their results. Prepared by two consultants, Dr. Joan M. Davies and Dr. Hazel Inskip, the review focuses on the problems encountered when carrying out epidemiological studies on groups of the general population exposed to radiation, and using their results for radiological protection purposes. The primary objective is to provide background material for national authorities who have responsibilities in the field of radiological protection, as well as to other persons interested in this subject. It is published under the responsibility of the Secretary General of the OECD, and does not necessarily reflect the views of Member Governments

  4. Nailfold Capillaroscopic Monitoring as Preventive Medicine in Subjects Exposed to Ionising Radiation

    International Nuclear Information System (INIS)

    Pennarola, R.; Perdereau, B.; Trenta, G.; Cosset, J. M.

    2004-01-01

    Capillaroscopy consists of in vivo observation of microvessels using special microscopes with a short focal length. Normally, when looking at the nail fold, where capillaroscopy is commonly used, the capillaries ares arranged like hairpins, lined up in parallel or obliquely to the field of vision in three or four layers above the subpapillary venous network, approximately 20 loops per mm''2. Ionising radiation can badly damage the skin and underlying tissues. The capillary network is among the first structures to show an effect. Moderate doses of radiation cause damage endothelial cells with hypertrophy or hyperplasia of endothelial cells, which can block capillaries while having little effect on larger vessels. Occlusion of capillaries impedes blood flow no only in nearby tissue but also in areas farther away. Capillaroscopic examination of the nail fold is irreplaceable in the field of radioprotection especially in cases of exposure of the hands. Nailfold capillaroscopic monitoring lets us observe the degree to which qualitative and quantitative alterations of the capillaries are a function of the evolution of the lesion. Therefore, for biological monitoring of subjects exposed to radiation the authors propose to use this microvascular quantitative analysis of the nailfold region. Experience, matured over many years by our team, highlights the relation between the sum of repeated exposure and the importance of tissue alterations evidenced by microcirculation. (Author) 9 refs

  5. TL and LOE dosimetric evaluation of diamond films exposed to beta and ultraviolet radiation

    International Nuclear Information System (INIS)

    Preciado F, S.; Melendrez, R.; Chernov, V.; Barboza F, M.; Schreck, M.; Cruz Z, E.

    2005-01-01

    The diamond possesses a privileged position regarding other materials of great technological importance. Their applications go from the optics, microelectronics, metals industry, medicine and of course as dosemeter, in the registration and detection of ionizing and non ionizing radiation. In this work the results of TL/LOE obtained in two samples of diamond of 10 μm thickness grown by the chemical vapor deposition method (CVD) assisted by microwave plasma. The films were deposited in a silicon substrate (001) starting from a mixture of gases composed of CH 4 /H 2 and 750 ppm of molecular nitrogen as dopant. The samples were exposed to beta radiation (Sr 90 / Y 90 ) and ultraviolet, being stimulated later on thermal (TL) and optically (LOE) to evaluate their dosimetric properties. The sample without doping presented high response TL/LOE to the ultraviolet and beta radiation. The TL glow curve of the sample without doping showed two TL peaks with second order kinetics in the range of 520 to 550 K, besides a peak with first order kinetics of more intensity around 607 K. The TL efficiency of the non doped sample is bigger than the doped with nitrogen; however the LOE efficiency is similar in both samples. The results indicate that the CVD diamond possesses excellent perspectives for dosimetric applications, with special importance in radiotherapy due to it is biologically compatible with the human tissue. (Author)

  6. Late radiation effects in Marshall Islanders exposed to fallout 28 years ago

    International Nuclear Information System (INIS)

    Conard, R.A.

    1984-01-01

    In 1954, following detonation of a megaton nuclear device at Bikini, an unfortunate accident occurred owing to an unpredicted shift in winds resulting in exposure to radioactive fallout of 250 Marshallese people, 28 American servicemen on atolls to the east, and 23 Japanese fishermen on their fishing vessel. In this presentation, medical findings in the exposed Marshallese noted over the past 28 years is briefly reviewed with particular emphasis on late effects on the thyroid gland. The Marshallese were too far distant from the detonation for any direct effects, and their exposure was due entirely to fallout radiation during the 2 days prior to evacuation. This consisted of penetrating whole-body gamma radiation, irradiation of the skin (principally beta radiation) from fallout deposited on the skin, and internal absorption of radionuclides from ingestion of contaminated food and water. The most serious internal exposure was that to the thyroid from radioiodines, which were relatively abundant in the fallout. 63 references, 1 figure, 4 tables

  7. Quantification of micronuclei in blood lymphocytes of patients exposed to gamma radiation for dose absorbed assessment

    International Nuclear Information System (INIS)

    Barbosa, Isvania Maria Serafim da Silva

    2003-02-01

    Dose assessment in an important step to evaluate biological effects as a result of individual exposure to ionizing radiation. The use of cytogenetic dosimetry based on the quantification of micronuclei in lymphocytes is very important to complement physical dosimetry, since the measurement of absorbed dose cannot be always performed. In this research, the quantification of micronuclei was carried out in order to evaluate absorbed dose as a result of radiotherapy with 60 Co, using peripheral blood samples from 5 patients with cervical uterine cancer. For this purpose, an aliquot of whole blood from the individual patients was added in culture medium RPMI 1640 supplemented with fetal calf serum and phytohaemagglutinin. The culture was incubated for 44 hours. Henceforth, cytochalasin B was added to block the dividing lymphocytes in cytokinesis. The culture was returned to the incubator for further of 28 hours. Thus, cells were harvested, processed and analyzed. Values obtained considering micronuclei frequency after pelvis irradiation with absorption of 0,08 Gy and 1,8 Gy were, respectively, 0,0021 and 0,052. These results are in agreement with some recent researches that provided some standard values related to micronuclei frequency induced by gamma radiation exposure in different exposed areas for the human body. The results presented in this report emphasizes biological dosimetry as an important tool for dose assessment of either total or partial-body exposure to ionizing radiation, mainly in retrospective dose investigation. (author)

  8. Rifampicin sensitivity of residual RNA synthesis in Escherichia coli cells exposed to ultraviolet radiation and combined ultraviolet and γ radiations

    International Nuclear Information System (INIS)

    Prakash, R.K.; Netrawali, M.S.; Pradhan, D.S.

    1976-01-01

    UV-irradiation prevents rifampicin inhibition of the initiation of RNA synthesis by E.coli cells, but such rifampicin insensitivity is not exhibited by the residual RNA synthesis in γ-irradiated cells. Studies of the rate of [ 3 H]-uridine incorporation by E.coli cells at various times of incubation have been used to show that when γ-irradiation was given either before or after UV-irradiation of cells, the observed rifampicin insensitivity of residual RNA synthesis in the UV-irradiated cells was obliterated. RNA synthesis in cells subjected to combined exposures of UV- and γ-radiations was lowered to a lesser extent than that in the cells exposed to UV-irradiation alone. Possible mechanisms are discussed. (U.K.)

  9. Rifampicin sensitivity of residual RNA synthesis in Escherichia coli cells exposed to ultraviolet radiation and combined ultraviolet and. gamma. radiations

    Energy Technology Data Exchange (ETDEWEB)

    Prakash, R K; Netrawali, M S; Pradhan, D S [Bhabha Atomic Research Centre, Bombay (India). Biochemistry and Food Technology Div.

    1976-09-01

    UV-irradiation prevents rifampicin inhibition of the initiation of RNA synthesis by E.coli cells, but such rifampicin insensitivity is not exhibited by the residual RNA synthesis in ..gamma..-irradiated cells. Studies of the rate of (/sup 3/H)-uridine incorporation by E.coli cells at various times of incubation have been used to show that when ..gamma.. irradiation was given either before or after uv-irradiation of cells, the observed rifampicin insensitivity of residual RNA synthesis in the uv-irradiated cells was obliterated. RNA synthesis in cells subjected to combined exposures of uv- and ..gamma..-radiations was lowered to a lesser extent than that in the cells exposed to uv-irradiation alone. Possible mechanisms are discussed.

  10. Photoionization of atoms and small molecules using synchrotron radiation

    International Nuclear Information System (INIS)

    Ferrett, T.A.

    1986-11-01

    The combination of synchrotron radiation and time-of-flight electron spectroscopy has been used to study the photoionization dynamics of atoms (Li) and small molecules (SF 6 , SiF 4 , and SO 2 ). Partial cross sections and angular distribution asymmetry parameters have been measured for Auger electrons and photoelectrons as functions of photon energy. Emphasis is on the basic understanding of electron correlation and resonant effects as manifested in the photoemission spectra for these systems. 254 refs., 46 figs., 10 tabs

  11. Optically stimulated luminescence of natural NaCl mineral from Dead Sea exposed to gamma radiation

    International Nuclear Information System (INIS)

    Roman L, J.; Cruz Z, E.; Pina L, Y. I.; Marcazzo, J.

    2016-10-01

    Luminescence properties such as radioluminescence, thermoluminescence and optically stimulated luminescence have been studied on natural sodium chloride (NaCl) for dosimetric purposes in retrospective dosimetry (Timar-Gabor et al., 2013; Druzhyna et al., 2016). In this work, the optically stimulated luminescence (Cw-OSL) emissions of natural salt minerals, collected from Dead Sea in summer of 2015, were studied. The Cw-OSL dose response of natural salt was analyzed in the range between 0.2 and 10 Gy gamma dose of "6"0Co. Samples exposed at 3 Gy exhibited good repeatability with a variation coefficient of 4.6%. The thermal stability of the Cw-OSL response was analyzed to different temperatures from 50 up to 250 degrees Celsius using a heating rate of 5 degrees Celsius. The results showed that the natural Dead Sea salt minerals could be applied as natural dosimeter of gamma radiation. (Author)

  12. Food collection and response to pheromones in an ant species exposed to electromagnetic radiation.

    Science.gov (United States)

    Cammaerts, Marie-Claire; Rachidi, Zoheir; Bellens, François; De Doncker, Philippe

    2013-09-01

    We used the ant species Myrmica sabuleti as a model to study the impact of electromagnetic waves on social insects' response to their pheromones and their food collection. We quantified M. sabuleti workers' response to their trail, area marking and alarm pheromone under normal conditions. Then, we quantified the same responses while under the influence of electromagnetic waves. Under such an influence, ants followed trails for only short distances, no longer arrived at marked areas and no longer orientated themselves to a source of alarm pheromone. Also when exposed to electromagnetic waves, ants became unable to return to their nest and recruit congeners; therefore, the number of ants collecting food increases only slightly and slowly. After 180 h of exposure, their colonies deteriorated. Electromagnetic radiation obviously affects social insects' behavior and physiology.

  13. Thermoluminescent dosimetry of new phosphors of Zn O exposed to beta radiation

    International Nuclear Information System (INIS)

    Cruz V, C.; Burruel I, S.E.; Grijalva M, H.; Barboza F, M.; Bernal, R.

    2004-01-01

    In this work, we report the thermoluminescence dosimetry of a new Zn O phosphor obtained by annealing of Zn S powder precipitated when Zn S films were grown by employing a CBD method. The collected Zn S powder was pressed in a die to form pellets which were subjected to different thermal treatments under air atmosphere. X-ray diffraction (XRD) patterns and energy-dispersive X-ray Spectrometry (EDS) analyses confirmed the transformation of Zn S to Zn O. The phosphors thus obtained were exposed to high doses of beta radiation and their thermoluminescent dosimetry show that these new phosphors are materials suitable to be used in high dose thermoluminescence dosimetry. (Author)

  14. Optically stimulated luminescence of natural NaCl mineral from Dead Sea exposed to gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Roman L, J.; Cruz Z, E. [UNAM, Instituto de Ciencias Nucleares, Ciudad Universitaria, 04510 Ciudad de Mexico (Mexico); Pina L, Y. I. [UNAM, Facultad de Ciencias, Ciudad Universitaria, 04510 Ciudad de Mexico (Mexico); Marcazzo, J., E-mail: jesus.roman@nucleares.unam.mx [Instituto de Fisica Arroyo Seco - UNICEN, Pinto 399, 7000 Tandil (Argentina)

    2016-10-15

    Luminescence properties such as radioluminescence, thermoluminescence and optically stimulated luminescence have been studied on natural sodium chloride (NaCl) for dosimetric purposes in retrospective dosimetry (Timar-Gabor et al., 2013; Druzhyna et al., 2016). In this work, the optically stimulated luminescence (Cw-OSL) emissions of natural salt minerals, collected from Dead Sea in summer of 2015, were studied. The Cw-OSL dose response of natural salt was analyzed in the range between 0.2 and 10 Gy gamma dose of {sup 60}Co. Samples exposed at 3 Gy exhibited good repeatability with a variation coefficient of 4.6%. The thermal stability of the Cw-OSL response was analyzed to different temperatures from 50 up to 250 degrees Celsius using a heating rate of 5 degrees Celsius. The results showed that the natural Dead Sea salt minerals could be applied as natural dosimeter of gamma radiation. (Author)

  15. Hematology evaluation in workers exposed to ionizing radiation of a radiotherapy service

    International Nuclear Information System (INIS)

    Lopez P, G.; Frometa S, I.

    1996-01-01

    The verification of hematology indicators is performed as a routine at the initial and periodic evaluation of the health of workers which are exposed to ionizing radiation. In order to analyze the behavior of such indicators in connection with the exposure time and the received dose, a sample (n=74) of workers of the Radiotherapy Service in the Cancer Hospital in La Habana has been studied during 8 years. It was observed that the mean number of leucocytes, blood platelet and hemoglobin did not show meaningful variations and oscillated into normal limits; however an increase in the number of leukopenia cases was detected when the exposure time and the accumulated dose increased. This increase was two, three times higher in the last year of pursuit in connection with the initial value. (authors). 8 refs., 2 figs., 3 tabs

  16. Luminescent emission of LiF: Mg, Ti exposed to UV radiation

    International Nuclear Information System (INIS)

    Estrada G, A.; Castano M, V.M.; Cruz Z, E.; Garcia F, F.

    2002-01-01

    It was investigated the luminescent emission stimulated by heat (Tl) of LiF: Mg, Ti crystals which were exposed to UV radiation coming from a mercury lamp. Since this crystal depends on the thermal history, it has been used a thermal treatment consisting of a baking at 380 C during one hour for each reading and they were irradiated with UV. The brilliance curves between 5 and 840 minutes of exposure in the face of UV light were obtained. An important loss in the response, starting from 150 minutes of irradiation was observed. Also the relative intensity of the brilliance curve decay when the crystals being stored in darkness and room temperature conditions, which is according to the results in the literature about. (Author)

  17. Optically stimulated luminescence dosimetry performance of natural Brazilian topaz exposed to beta radiation

    International Nuclear Information System (INIS)

    Bernal, R.; Souza, D. N.; Valerio, M. E. G.; Cruz-Vazquez, C.; Barboza-Flores, M.

    2006-01-01

    Optically stimulated luminescence (OSL) has become the technique of choice in many areas of dosimetry. Natural materials like topaz are available in large quantities in Brazil and other countries. They have been studied to investigate the possibility of use its thermoluminescence (TL) properties for dosimetric applications. In this work, we investigate the possibility of utilising the OSL properties of natural Brazilian topaz in dosimetry. Bulk topaz samples were exposed to doses up to 100 Gy of beta radiation and the integrated OSL as a function of the dose showed linear behaviour. The fading occurs in the first 20 min after irradiation but it is <6% of the integrated OSL measured shortly after exposure. We conclude that natural colourless topaz is a very suitable phosphor for OSL dosimetry. (authors)

  18. Radiation processing of organics and biological materials exposed to ocean world surface conditions.

    Science.gov (United States)

    Hand, K. P.; Carlson, R. W.

    2017-12-01

    Assessing the habitability of ocean worlds, such as Europa and Enceladus, motivates a search for endogenous carbon compounds that could be indicative of a habitable, or even inhabited, subsurface liquid water environment. We have examined the role of destruction and synthesis of organic compounds via 10 keV electron bombardment of ices generated under temperature and pressure conditions comparable to Europa and Enceladus. Short-chain organics and ammonia, in combination with water, were exposed to Mrad to Grad doses and observed to evolve to a `lost' carbon fraction (CO and CO2) and a `retained' carbon fraction (consisting of a highly refractory `ocean world tholin' populated by highly radiation resistant carbonyl, aldehyde, and nitrile components). The retained fraction is of key importance as this likely represents the observable fraction for future spacecraft investigations. We also irradiated microbial spores (B. pumilis) to approximately 2 Grad and have found persistence of biomolecule fractions derived from proteins and nucleic acids.

  19. Comparative study on the catalase activity in grassy and forestry plants exposed to low gamma radiation

    International Nuclear Information System (INIS)

    Arteni, A. A; Mocanasu, R. C.; Arteni, V.; Creanga, I.

    2001-01-01

    Since gamma rays level in atmosphere occasionally increases affecting biosphere,the radiation effect damages seriously certain plant species. This study was focused on a grassy species,Triticum aestivum, in comparison to a forestry species, namely Quercus robur. Young plantlets were exposed to weak gamma rays delivered by a laboratory 60 Co source, for different irradiation times. The enzymatic activity of catalase was evaluated using biochemical methods. Triticum aestivum presented a slight enhancing of catalase, both in caryopsides and leafs. Quercus robur revealed a rapid linear enhancing of catalase in saplings cultivated in laboratory while saplings grown in forestry were characterized by a reduced catalase activity. Concurrent phenomena of enzyme biosynthesis stimulation and enzyme structure damage are presumed to be the cause of such behavior. (authors)

  20. Endothelial dysfunction in rectal cancer patients chronically exposed to ionizing radiation

    Energy Technology Data Exchange (ETDEWEB)

    Rakhypbekov, Tolebay; Pak, Laura; Chaizhunusova, Nailya; Manambayeva, Zukhra; Tokanova, Sholpan; Madiyeva, Madina [Semey State Medical University, Semey (Kazakhstan); Inoue, Ken [Kochi University, Health Service Center, Kochi (Japan); Kawano, Noriyuki; Hoshi, Masaharu [Hiroshima University, Hiroshima (Japan); Takeichi, Nobuo [Takeichi Clinic, Hiroshima (Japan); Noso, Yoshihiro [Shimane University, Department of General Surgery, Faculty of Medicine, Shimane (Japan); Khozhayev, Arman; Molgazhdarov, Maulen [The Kazakh National Medical University of S.D.Asfendiyarov, Department of Oncology, Almaty (Kazakhstan); Olzhaev, Sayakhat [Almaty Regional Oncologic Hospital, Department of Oncology, Almaty (Kazakhstan)

    2017-08-15

    We sought to identify the features of endothelial function in rectal cancer patients who were exposed to chronic ionizing radiation from a nuclear test site in Kazakhstan. We examined 146 individuals, 76 of whom were rectal cancer patients. The existence of a complex of disturbances of the endothelium and hemostasis systems in patients vs non-patients was revealed. Endothelial dysfunction was expressed as an increase of nitric oxide (NO) production along with decreases in vasodilatation function, and increased levels of von Willebrand factor in blood, along with an increase in the number of circulating endotheliocytes. Significant correlations between indicators of endothelial function and vascular-platelet hemostasis were observed. These changes and their interrelations were expressed more strongly in the patients who lived in the contaminated area around the nuclear test site. Such patients could have an increased risk of thrombosis and other complications after the treatment of a malignant neoplasm. (orig.)

  1. Monitoring the genetic health of humans accidentally exposed to ionizing radiation of Cesium-137 in Goiania (Brazil)

    Energy Technology Data Exchange (ETDEWEB)

    Cruz, A. da; Glickman, B.W. [Victoria Univ., BC (Canada). Dept. of Biology. Centre for Environmental Health

    1997-12-31

    A long-term genetic monitoring of the Goiania population exposed to ionizing radiation of Cesium-137 is described using cytogenetic and molecular endpoints. Two molecular methods were employed: the hprt clonal assay, involving in vitro selection of 6-thioguanine-resistant hprt mutant clones which were characterized at the molecular level using RT-PCR and genomic analysis. Ionizing radiation exposure initially elevated hprt mutation frequency which gradually diminished, so that no significant increase was observed 4.5 years after original exposure. The spectrum of hprt mutation recovered from 10 individuals exposed to relatively high doses of radiation revealed a 4-fold increase in the frequency of A:T{yields}G:C transitions. Additionally, a two-fold increase in the frequency of deletions was observed which may reflect radiation-induced DNA strand breakage; determination of micro satellite instability using fluorescent PCR and genomic DNA from mononuclear cells. The frequency distribution of somatic micro satellite alterations in exposed and non-exposed populations were not different. We estimated the risk associated with radiation exposure for the exposed Goiania population. The estimated genetic risk of dominant disorders in the first post-exposure generation was increased by approximately a 24-fold. The risk of carcinogenesis was increased by a factor of 1.5 13 refs.; e-mail: acruz at uvic.ca.; bwglick at uvic.ca

  2. What can be learned from epidemiologic studies of persons exposed to low doses of radiation?

    International Nuclear Information System (INIS)

    Gilbert, E.S.

    1993-04-01

    The main objective of radiation risk assessment is to determine the risk of various adverse health effects associated with exposure to low doses and low dose rates. Extrapolation of risks from studies of persons exposed at high doses (generally exceeding 1 Sv) and dose rates has been the primary approach used to achieve this objective. The study of Japanese atomic bomb survivors in Hiroshima and Nagasaki has played an especially important role in risk assessment efforts. A direct assessment of the dose-response function based on studies of persons exposed at low doses and dose rates is obviously desirable. This paper focuses on the potential of both current and future nuclear workers studies for investigating the dose-response functions at low doses, and also discusses analyses making use of the low dose portion of the atomic bomb survivor data. Difficulties in using these data are the statistical imprecision of estimated dose-response parameters, and potential bias resulting from confounding factors and from uncertainties in dose estimates

  3. Pulsed EPR analysis of tooth enamel samples exposed to UV and {gamma}-radiations

    Energy Technology Data Exchange (ETDEWEB)

    Marrale, M., E-mail: marrale@unipa.it [Dipartimento di Fisica, Universita di Palermo, Viale delle Scienze, Edificio 18, 90128 Palermo (Italy); Gruppo V Sezione INFN, Catania, Italy and Unita CNISM, Palermo (Italy); Longo, A.; Brai, M. [Dipartimento di Fisica, Universita di Palermo, Viale delle Scienze, Edificio 18, 90128 Palermo (Italy); Gruppo V Sezione INFN, Catania (Italy) and Unita CNISM, Palermo (Italy); Barbon, A.; Brustolon, M. [Dipartimento di Scienze Chimiche, Universita degli Studi di Padova, Via Marzolo 1, 35131 Padova (Italy); Fattibene, P. [Istituto Superiore di Sanita, Viale Regina Elena 299, 00161 Rome (Italy)

    2011-09-15

    The electron paramagnetic resonance (EPR) spectroscopy is widely applied for retrospective dosimetric purposes by means of quantitative detection of radicals in tooth enamel and bone samples. In this work we report a study by cw and pulsed EPR on two samples of human tooth enamel respectively irradiated by UV (254 nm) and {gamma}-exposed. The continuous wave (cw) EPR spectra have shown the usual presence in both samples of two types of CO{sub 2}{sup -} radicals, with axial and orthorombic g tensors. We have obtained the electron spin echo detected EPR (ED-EPR) spectra at 80 K of the two samples, and we have shown that they are suitable to mark the difference between the effects produced by the different irradiations. At low temperature the contribution to the ED-EPR spectrum of the mobile radical with the axial g tensor is still present in the UV irradiated sample, but not in the {gamma}-irradiated one, where its dynamics is too slow to average the g tensor. We have moreover studied the two-pulse electron spin echo decay on varying the microwave power, a well established method for measuring the Instantaneous Diffusion. We have found that the spectral diffusion parameter is almost the same for both radiation types, whereas the Instantaneous Diffusion is significantly larger for {gamma}-exposed samples than for UV irradiated ones. This difference is due to a higher local microscopic concentration of free radicals for samples irradiated with {gamma} photons.

  4. Biological responses of two soybean cultivars exposed to enhanced UVB radiation

    International Nuclear Information System (INIS)

    D'Surney, S.J.; Tschaplinski, T.J.; Edwards, N.T.; Shugart, L.R.

    1993-01-01

    A UVB exposure and monitoring system has been established at the Oak Ridge National Laboratory's Global Climate Change Research Facility. The system consists of a power supply, and data acquisition and exposure equipment to accomplish controlled, elevated exposure of terrestrial plants to UVB. Plant biomass, selected compounds that absorb UV radiation, and DNA integrity/damage were measured for two soybean cultivars [Glycine max (L.) Merr.] Forrest and Essex exposed to elevated UVB (32% above ambient) in this system. The biomass of each major plant organ was observed to be less in soybean cultivar Forrest upon exposure to enhanced UVB with the greatest response in seed pods and stems. In contrast, soybean cultivar Essex showed no biomass response to elevated UVB. Enhanced UVB caused significant (P < 0.1) changes in concentrations of UV-absorbing compounds in both soybean cultivars. The Essex cultivar had an increase in UV-absorbing compounds, whereas a decline was observed for soybean Forrest. There was a decrease in the integrity of DNA, as measured by strand breaks, from both cultivars at 30 and 52 days to exposure. DNA pyrimidine dimers in isolated plant DNA were measured with Micrococcus luteus UV endonuclease. DNA from soybean Forrest exposed to UVB and sampled at 30 and 52 days of exposure had significantly greater (P<0.05) pyrimidine dimer concentration (dimer frequency ≈ 1 dimer per 28,000 DNA bases) than either cultivar exposed to UV treatment for 1 day or Essex at days 30–52 (dimer frequencies < /1 per 120,000 bases of DNA). Decrease in DNA integrity and biomass production in Forrest under elevated UVB may be related to the inability to maintain high concentrations of UV-absorbing compounds in leaves. The tolerant cultivar Essex increased the concentration of UV-absorbing compounds while maintaining biomass production and DNA integrity under elevated UVB

  5. Molecular markers for assessment of radiation-induced oxidant stress of occupationally exposed persons

    International Nuclear Information System (INIS)

    Stankova, K.; Zaharieva, E.; Aneva, N.; Kazarska, O.; Boteva, R.

    2013-01-01

    Full text: Introduction: The biological effects of ionizing radiation (IR) are mainly due to high creativity, oxygen - containing free radicals and molecules known as Reactive Oxygen Species (ROS). After irradiation the cells accumulate ROS, which may induce destructive changes in all cell structures and macromolecules (membranes, DNA, RNA , proteins and enzymes) and result in abnormalities on cell and tissue level. The effects of ROS are particularly important in chronic oxidative stress induced by prolonged occupational exposure that can permanently disrupt cellular redox homeostasis, which increase the risk of oncogenic, neurodegenerative, cardiovascular and other diseases. This requires the study of the antioxidant status of the Kozloduy NPP personnel who are professionally exposed to low dose irradiation. Materials and methods: As an antioxidant status markers, changes in the levels of the ROS and the electrochemical potential at mitochondrial lymphocytes (both before and after their additional in vitro exposure to 3 Gy), as well as the antioxidant activity of blood plasma are analyzed. The study was conducted with spectral methods and includes 40 professionally exposed people from the Kozloduy NPP (mean age 44.3, and radiation exposure from 0,1 to 257,9 mSv) and 20 unexposed controls (mean age 46.5 years). Results: Statistical analysis of the data shows that chronic exposure to low doses IR as a result of occupation exposure does not lead to significant changes in the levels of the ROS, the antioxidant activity of plasma and mitochondrial electrochemical potential. More significant impact on these indicators proves the age of the respondents, which is explained by a decrease in the activity of the cellular reparative and antioxidant systems induced by the natural processes of aging. Results for occupational exposure and non-exposure persons were heterogeneous due to the individual radio sensitivity of the persons included in biomonitoring. Conclusion

  6. Influence of seeds extract of Trigonella foenum graecum (Methi) on mice exposed to gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Chaudhary, R; Gupta, U; Goyal, P.K., E-mail: pkgoyal2002@gmail.co [Radiation and Cancer Biology Laboratory, Department of Zoology, University of Rajasthan, Jaipur, (India)

    2010-07-01

    The present study has been carried out to evaluate the radioprotective effect of Trigonella foenum seeds extract (TFE) on peripheral blood of mice. For this purpose, mice were orally given double distilled water (control) or optimum dose (100 mg/kg of body weight per day) of TFE for five consecutive days (experimental). Thirty minutes after the last administration of double distilled water or TFE, these were exposed whole-body to 5 Gy gamma radiation and autopsied between 12 hours to 30 days for hematological and biochemical estimation. Total erythrocyte count, hemoglobin level, and hematocrit percentage were decreased from normal in both the groups. A significant increase in these parameters was observed in TFE administered irradiated group, in contrast to without TFE irradiated one, by restoring towards normal values at the end of the experiment. From the results, it is evident that TFE may be responsible for the protection of stem cells in bone marrow which subsequently resulted in higher hematological constituents in peripheral blood. The study concludes the prophylactic use of such plant extract against radiation induced hematological alterations. (author)

  7. PHYTOTHERAPEUTIC EFFECT OF AVOCADOS AND SOYA AS DRUG ON HEART OF RATS EXPOSED TO GAMMA RADIATION

    International Nuclear Information System (INIS)

    OMRAN, M.F.; IBRAHIM, N.K.; ABU-ZIED, N.M.

    2008-01-01

    This study was planed to determine the role of single oral dose of avocados and soya in irradiated rats exposed to gamma radiation. the experimental animals were randomly divided into four groups; 12 rats for each. Group 1: kept as control. Group 2: rats received piascledine for 14 consecutive days. Group 3: rats submitted to whole body gamma rays (4 Gy). Group 4: rats received the same piascledine 14 days post-exposure to 4 Gy gamma radiation. The animals were weighed then dissected after one and fourteen days post-administration and the cardiac tissue and plasma were stored at 12 oC till used for biochemical analysis and kept in ice. The following parameters were determined: plasma total cholesterol, triacylglycerol, high density lipoprotein-cholesterol, low density lipoprotein-cholesterol, LDH, phospholipids, ALT, CPK and TBARS. In cardiac tissue, determinations of total cholesterol, triacylglycerol, phospholipids and TBARS were conducted.It can be concluded that administration of avocados and soy as natural drug (piascledine) post-irradiation in rats is a favorable modificator against the impaired physiological processes in animal body due to gamma irradiation

  8. Mental and behavioural disorders in Belarusian persons exposed in utero to radiation following the Chernobyl accident

    International Nuclear Information System (INIS)

    Igumnov, S.A.

    2007-01-01

    Complete text of publication follows. Objectives - Investigation of mental health and psychosocial development of persons from Belarus exposed in utero to radiation following the Chernobyl accident in 1986. Methods - Ten year follow-up of 245 persons exposed in utero following the Chernobyl accident and 239 persons of the same age from non- or slightly contaminated regions. Psychiatric and psychosocial assessments were performed at the age 6-7 years, 10-12 years, and 15-16 years. Psychiatric diagnosis of the children in both groups was established by means of a semi-structured clinical interview based on the diagnostic criteria of the ICD-10, Chapter V (Mental and behavioural disorders). Results - The persons who were exposed to the influence of radionuclides antenatally showed a relative increase in mental and behavioral disorders compared to the control group. This was mainly due to the increased prevalence of cases of specific developmental disorders of speech and language, specific developmental disorders of motor function, emotional disorders and disorders of social functioning. Phobic anxiety disorders were the most common emotional disorders in both groups (27 cases - 10.8 % in the exposed group vs 17 cases - 6.8 % in the control group. The relative risk of the development of emotional disorders was 2.67 (P<0.001). There was no difference between the cases and control groups in terms of the prevalence of mental retardation, specific learning disorders, hyperkinetic disorders and other mental and behavioral disorders. At adolescent age there was also no difference in the prevalence of conduct disorders between the cases and the control groups. Conduct disorders were often associated with unfavorable psychological surroundings, including unsatisfactory family relations and learning difficulties at school. Conduct disorders at adolescent age (15-16) were closely correlated with hyperkinetic disorders (r=0.72; P<0.01), disorders of scholastic skills (r=0.72; P<0

  9. Effect of adiponectin deficiency on intestinal damage and hematopoietic responses of mice exposed to gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Ponemone, Venkatesh; Fayad, Raja; Gove, Melissa E.; Pini, Maria [Department of Kinesiology and Nutrition, University of Illinois at Chicago, Chicago, IL 60612 (United States); Fantuzzi, Giamila, E-mail: giamila@uic.edu [Department of Kinesiology and Nutrition, University of Illinois at Chicago, Chicago, IL 60612 (United States)

    2010-08-07

    Adiponectin (APN) is an adipose tissue-derived cytokine that regulates insulin sensitivity and inflammation. It is also involved in modulation of cell proliferation by binding to various growth factors. Based on its known effects in modulating cell proliferation and oxidative stress, APN may potentially be involved in regulating tissue damage and repair following irradiation. Adiponectin KO mice and their WT littermates were exposed to a single whole-body dose of 3 or 6 Gy gamma radiation. Radiation-induced alterations were studied in jejunum, blood, bone marrow and thymus at days 1 and 5 post-irradiation and compared with sham-irradiated groups. In WT mice, irradiation did not significantly alter serum APN levels while inducing a significant decrease in serum leptin. Irradiation caused a significant reduction in thymocyte cellularity, with concomitant decrease in CD4{sup +}, CD8{sup +} and CD4{sup +}CD8{sup +} T cell populations, with no significant differences between WT and APN KO mice. Irradiation resulted in a significantly higher increase in the frequency of micronucleated reticulocytes in the blood of APN KO compared with WT mice, whereas frequency of micronucleated normochromatic erythrocytes in the bone marrow at day 5 was significantly higher in WT compared with APN KO mice. Finally, irradiation induced similar alterations in villus height and crypt cell proliferation in the jejunum of WT and APN KO mice. Jejunum explants from sham-irradiated APN KO mice produced higher levels of IL-6 compared with tissue from WT animals, but the difference was no longer apparent following irradiation. Our data indicate that APN deficiency does not play a significant role in modulating radiation-induced gastrointestinal injury in mice, while it may participate in regulation of damage to the hematopoietic system.

  10. Effect of adiponectin deficiency on intestinal damage and hematopoietic responses of mice exposed to gamma radiation

    International Nuclear Information System (INIS)

    Ponemone, Venkatesh; Fayad, Raja; Gove, Melissa E.; Pini, Maria; Fantuzzi, Giamila

    2010-01-01

    Adiponectin (APN) is an adipose tissue-derived cytokine that regulates insulin sensitivity and inflammation. It is also involved in modulation of cell proliferation by binding to various growth factors. Based on its known effects in modulating cell proliferation and oxidative stress, APN may potentially be involved in regulating tissue damage and repair following irradiation. Adiponectin KO mice and their WT littermates were exposed to a single whole-body dose of 3 or 6 Gy gamma radiation. Radiation-induced alterations were studied in jejunum, blood, bone marrow and thymus at days 1 and 5 post-irradiation and compared with sham-irradiated groups. In WT mice, irradiation did not significantly alter serum APN levels while inducing a significant decrease in serum leptin. Irradiation caused a significant reduction in thymocyte cellularity, with concomitant decrease in CD4 + , CD8 + and CD4 + CD8 + T cell populations, with no significant differences between WT and APN KO mice. Irradiation resulted in a significantly higher increase in the frequency of micronucleated reticulocytes in the blood of APN KO compared with WT mice, whereas frequency of micronucleated normochromatic erythrocytes in the bone marrow at day 5 was significantly higher in WT compared with APN KO mice. Finally, irradiation induced similar alterations in villus height and crypt cell proliferation in the jejunum of WT and APN KO mice. Jejunum explants from sham-irradiated APN KO mice produced higher levels of IL-6 compared with tissue from WT animals, but the difference was no longer apparent following irradiation. Our data indicate that APN deficiency does not play a significant role in modulating radiation-induced gastrointestinal injury in mice, while it may participate in regulation of damage to the hematopoietic system.

  11. Modification in oxidative processes in muscle tissues exposed to laser- and light-emitting diode radiation.

    Science.gov (United States)

    Monich, Victor A; Bavrina, Anna P; Malinovskaya, Svetlana L

    2018-01-01

    Exposure of living tissues to high-intensity red or near-infrared light can produce the oxidative stress effects both in the target zone and adjacent ones. The protein oxidative modification (POM) products can be used as reliable and early markers of oxidative stress. The contents of modified proteins in the investigated specimens can be evaluated by the 2,4-dinitrophenylhydrazine assay (the DNPH assay). Low-intensity red light is able to decrease the activity of oxidative processes and the DNPH assay data about the POM products in the biological tissues could show both an oxidative stress level and an efficiency of physical agent protection against the oxidative processes. Two control groups of white rats were irradiated by laser light, the first control group by red light and the second one by near-infrared radiation (NIR).Two experimental groups were consequently treated with laser and red low-level light-emitting diode radiation (LED). One of them was exposed to red laser light + LED and the other to NIR + LED. The fifth group was intact. Each group included ten animals. The effect of laser light was studied by methods of protein oxidative modifications. We measured levels of both induced and spontaneous POM products by the DNPH assay. The dramatic increase in levels of POM products in the control group samples when compared with the intact group data as well as the sharp decrease in the POM products in the experimental groups treated with LED low-level light were statistically significant (p ≤ 0.05). Exposure of skeletal muscles to high-intensity red and near-infrared laser light causes oxidative stress that continues not less than 3 days. The method of measurement of POM product contents by the DNPH assay is a reliable test of an oxidative process rate. Red low-intensity LED radiation can provide rehabilitation of skeletal muscle tissues treated with high-intensity laser light.

  12. Analysis of chronic radiation exposure at small doses

    International Nuclear Information System (INIS)

    Krestinina, L.Y.

    2000-01-01

    The purpose of the study was to analyze the late effects of radiation exposure among residents of settlements located on the territory of the East-Urals Radiation Trace (EURT) in the Southern Urals. In 1957 an explosion occurred at the depot of radioactive waste in the Southern Urals. An area of 23000 km 2 was contaminated, with contamination density of over 0.1 Ci/m 2 for 90 Sr. There were 217 populated ares on that territory with total population about 270000. The residents of 22 villages with contamination density of over 4 Ci/km 2 for 90 Sr were evacuated. The times of evacuation differed from 7 to 670 days since the accident, depending on the level of contamination. In 1988-1993 an individualized registry was created at the Urals Research Center for Radiation Medicine (URCRM) which included information on the residents of 22 evacuated villages and a proportion of unevacuated residents of the EURT area. Currently, the registry contains data on 30000 residents. Of that number 17000 persons were born before, and 12000 after the accident (including about 9000 offspring of exposed residents evacuated from the EURT, and about 3000 persons who were born after the accident and have been living permanently in the EURT area). Over the 35-year period since the accident the residents have received mean effective doses ranging from 23 to 530 mSv. The mean effective doses received by permanent residents range from 5 to 60 mSv. The cohort of people exposed on the EURT territory was identified based on the information contained in the registry. If a person happened to be in the EURT area at the time of the accident, he/she was considered to be eligible for inclusion in the cohort. Over the 35-year period (from 1957 through 1992) 29.5% of 17872 residents died, and 35% of the original cohort were lost to follow-up for different reasons. To enable an analysis a control group was established which included residents of villages located outside, but close enough, to the EURT area

  13. Metabolomic applications in radiation biodosimetry: exploring radiation effects through small molecules.

    Science.gov (United States)

    Pannkuk, Evan L; Fornace, Albert J; Laiakis, Evagelia C

    2017-10-01

    Exposure of the general population to ionizing radiation has increased in the past decades, primarily due to long distance travel and medical procedures. On the other hand, accidental exposures, nuclear accidents, and elevated threats of terrorism with the potential detonation of a radiological dispersal device or improvised nuclear device in a major city, all have led to increased needs for rapid biodosimetry and assessment of exposure to different radiation qualities and scenarios. Metabolomics, the qualitative and quantitative assessment of small molecules in a given biological specimen, has emerged as a promising technology to allow for rapid determination of an individual's exposure level and metabolic phenotype. Advancements in mass spectrometry techniques have led to untargeted (discovery phase, global assessment) and targeted (quantitative phase) methods not only to identify biomarkers of radiation exposure, but also to assess general perturbations of metabolism with potential long-term consequences, such as cancer, cardiovascular, and pulmonary disease. Metabolomics of radiation exposure has provided a highly informative snapshot of metabolic dysregulation. Biomarkers in easily accessible biofluids and biospecimens (urine, blood, saliva, sebum, fecal material) from mouse, rat, and minipig models, to non-human primates and humans have provided the basis for determination of a radiation signature to assess the need for medical intervention. Here we provide a comprehensive description of the current status of radiation metabolomic studies for the purpose of rapid high-throughput radiation biodosimetry in easily accessible biofluids and discuss future directions of radiation metabolomics research.

  14. Spectrum of chromosomal aberrations in peripheral lymphocytes of hospital workers occupationally exposed to low doses of ionizing radiation

    International Nuclear Information System (INIS)

    Maffei, Francesca; Angelini, Sabrina; Forti, Giorgio Cantelli; Violante, Francesco S.; Lodi, Vittorio; Mattioli, Stefano; Hrelia, Patrizia

    2004-01-01

    Chromosome aberrations frequency was estimated in peripheral lymphocytes from hospital workers occupationally exposed to low levels of ionizing radiation and controls. Chromosome aberrations yield was analyzed by considering the effects of dose equivalent of ionizing radiation over time, and of confounding factors, such as age, gender and smoking status. Frequencies of aberrant cells and chromosome breaks were higher in exposed workers than in controls (P=0.007, and P=0.001, respectively). Seven dicentric aberrations were detected in the exposed group and only three in controls, but the mean frequencies were not significantly different. The dose equivalent to whole body of ionizing radiation (Hwb) did appear to influence the spectrum of chromosomal aberrations when the exposed workers were subdivided by a cut off at 50 mSv. The frequencies of chromosome breaks in both subgroups of workers were significantly higher than in controls (≤50 mSv, P=0.041; >50 mSv, P=0.018). On the other hand, the frequency of chromatid breaks observed in workers with Hwb >50 mSv was significantly higher than in controls (P=0.015) or workers with Hwb ≤50 mSv (P=0.046). Regarding the influence of confounding factors on genetic damage, smoking status and female gender seem to influence the increase in chromosome aberration frequencies in the study population. Overall, these results suggested that chromosome breaks might provide a good marker for assessing genetic damage in populations exposed to low levels of ionizing radiation

  15. Dosimetric methodology for extremities of individuals occupationally exposed to beta radiation using the optically stimulated luminescence technique

    International Nuclear Information System (INIS)

    Pinto, Teresa Cristina Nathan Outeiro

    2010-01-01

    A dosimetric methodology was established for the determination of extremity doses of individuals occupationally exposed to beta radiation, using Al 2 O 3 :C detectors and the optically stimulated luminescence (OSL) reader system microStar, Landauer. The main parts of the work were: characterization of the dosimetric material Al 2 O 3 :C using the OSL technique; establishment of the dose evaluation methodology; dose rate determination of beta radiation sources; application of the established method in a practical test with individuals occupationally exposed to beta radiation during a calibration simulation of clinical applicators; validation of the methodology by the comparison between the dose results of the practical test using the OSL and the thermoluminescence (TL) techniques. The results show that both the OSL Al-2O 3 :C detectors and the technique may be utilized for individual monitoring of extremities and beta radiation. (author)

  16. Radiation exposure of the radiological staff caused by radiography of small mammals, reptiles and birds

    International Nuclear Information System (INIS)

    Eckert, Yvonne

    2015-01-01

    maximum measured doses were 11.4 μSv for the eye-lenses, 11.5 μSv for the thyroid, 5.67 μSv for the thoracic region under the lead apron, 3.47 μSv for the thoracic region above the lead apron, 1.86 μSv for the gonads, 182 μSv for the fingers and 2.05 μSv for the foot. The median of all dose values was 0.53 μSv. The analysis of the results showed that radiation exposure of staff during X-raying small mammals, reptiles and birds was very low. Dose values at the eye-lenses, thyroid region and the fingers were regularly measurable and were annotated. The most exposed body regions were the fingers, which were closest to the primary x-ray field during X-raying. All in all, the measured dose values were in the range of a few microsievert. There was no influence of dose-influencing-parameters on the dose. There was a slight, non-significant trend that heavier patients caused higher dose values because of more scattered radiation, and also a higher kV-number was correlated with an increase in dose rate. The comparison between measuring positions above and under the protection clothes showed that even the values measured above the protection clothes were low. Furthermore, the protective effect of protection clothes was pointed out. Therefore it is not necessary to optimize the radiation protection measures in the clinic. The results of the estimation of the annual radiation exposure of the radiological staff underlined that the exposure is well below the national dose limits for occupationally exposed persons. The conservative maximum effective dose amounted to less than 1 % of the civilizing radiation exposure of all citizens in Germany. Moreover the evaluation of the results concerning the anesthetic risk of the patients showed that routinely X-raying without any anesthesia is justifiable.

  17. Small compact pulsed electron source for radiation technologies

    International Nuclear Information System (INIS)

    Korenev, Sergey

    2002-01-01

    The small compact pulsed electron source for radiation technologies is considered in the report. The electron source consists of pulsed high voltage Marx generator and vacuum diode with explosive emission cathode. The main parameters of electron source are next: kinetic energy is 100-150 keV, beam current is 5-200 A and pulse duration is 100-400 nsec. The distribution of absorbed doses in irradiated materials is considered. The physical feasibility of pulsed low energy electron beam for applications is considered

  18. Synchrotron radiation interferences between small dipoles at LEP

    International Nuclear Information System (INIS)

    Bovet, C.; Burns, A.; Meot, F.; Placidi, M.; Rossa, E.; Vries, J. de

    1997-06-01

    Synchrotron Radiation interferences between small dipoles in the very low (visible) frequency range have been studied at the LEP diagnostic mini-wiggler. Their understanding allowed a substantial brightness gain by adequate layout modifications. The phenomenon is described analytically in terms of time coherence effects. This serves as a basis for further detailed numerical simulations of the experiment by means of stepwise ray-tracing, and allows precise interpretation of the spectral, polarization and intensity measurements collected at LEP. It also provides guidelines for SR diagnostic at injection energy in LHC

  19. Uptake, depuration, and radiation dose estimation in zebrafish exposed to radionuclides via aqueous or dietary routes

    Energy Technology Data Exchange (ETDEWEB)

    Reinardy, Helena C., E-mail: helena.reinardy@plymouth.ac.uk [Ecotoxicology Research and Innovation Centre, School of Biomedical and Biological Sciences, The University of Plymouth (United Kingdom); Teyssie, Jean-Louis, E-mail: J.Teyssie@iaea.org [IAEA Marine Environment Laboratories, 4, Quai Antoine 1er, MC 98000 (Monaco); Jeffree, Ross A., E-mail: R.Jeffree@iaea.org [IAEA Marine Environment Laboratories, 4, Quai Antoine 1er, MC 98000 (Monaco); Faculty of Science, University of Technology, Sydney, PO Box 123, Broadway, NSW 2007 (Australia); Copplestone, David, E-mail: David.copplestone@stir.ac.uk [School of Biological and Environmental Sciences, University of Stirling (United Kingdom); Henry, Theodore B., E-mail: ted.henry@plymouth.ac.uk [Ecotoxicology Research and Innovation Centre, School of Biomedical and Biological Sciences, University of Plymouth (United Kingdom); Center for Environmental Biotechnology, University of Tennessee, Knoxville, TN 37996 (United States); Department of Forestry, Wildlife and Fisheries, University of Tennessee, Knoxville, TN 37996 (United States); Jha, Awadhesh N., E-mail: A.Jha@plymouth.ac.uk [Ecotoxicology Research and Innovation Centre, School of Biomedical and Biological Sciences, The University of Plymouth (United Kingdom)

    2011-09-01

    Understanding uptake and depuration of radionuclides in organisms is necessary to relate exposure to radiation dose and ultimately to biological effects. We investigated uptake and depuration of a mixture of radionuclides to link bioaccumulation with radiation dose in zebrafish, Danio rerio. Adult zebrafish were exposed to radionuclides ({sup 54}Mn, {sup 60}Co, {sup 65}Zn, {sup 75}Se, {sup 109}Cd, {sup 110m}Ag, {sup 134}Cs and {sup 241}Am) at tracer levels (< 200 Bq g{sup -1}) for 14 d, either via water or diet. Radioactivity concentrations were measured in whole body and excised gonads of exposed fish during uptake (14 d) and depuration phases (47 d and 42 d for aqueous and dietary exposures respectively), and dose rates were modelled from activity concentrations in whole body and exposure medium (water or diet). After 14-day aqueous exposure, radionuclides were detected in decreasing activity concentrations: {sup 75}Se > {sup 65}Zn > {sup 109}Cd > {sup 110m}Ag > {sup 54}Mn > {sup 60}Co > {sup 241}Am > {sup 134}Cs (range: 175-8 Bq g{sup 1}). After dietary exposure the order of radionuclide activity concentration in tissues (Bq g{sup -1}) was: {sup 65}Zn > {sup 60}Co > {sup 75}Se > {sup 109}Cd > {sup 110m}Ag > {sup 241}Am > {sup 54}Mn > {sup 134}Cs (range: 91-1 Bq g{sup -1}). Aqueous exposure resulted in higher whole body activity concentrations for all radionuclides except {sup 60}Co. Route of exposure did not appear to influence activity concentrations in gonads, except for {sup 54}Mn, {sup 65}Zn, and {sup 75}Se, which had higher activity concentrations in gonads following aqueous exposure. Highest gonad activity concentrations (Bq g{sup -1}) were for {sup 75}Se (211), {sup 109}Cd (142), and {sup 65}Zn (117), and highest dose rates ({mu}Gy h{sup -1}) were from {sup 241}Am (aqueous, 1050; diet 242). This study links radionuclide bioaccumulation data obtained in laboratory experiments with radiation dose determined by application of a dosimetry modelling tool, an

  20. Sensible biological models to be exposed to VDT (Video Display Terminal) radiations in human male reproduction

    International Nuclear Information System (INIS)

    Tritto, J.; North, M.-O.; Laverdure, A.M.; Surbeck, J.

    1999-01-01

    Temperature and environmental effects, particularly endocrine disrupters and EMF radiations, are actively investigated in human and non-human reproduction experimental models. Sensitivity and specificity of the different cell types of the testes seminiferous tubules in animals and in human are evaluated, showing a specific responsiveness of spermatogonia (SPG) and resting pachytene spermatocytes (SPC). At 32 o C the 24 h short-term cultures of biopsies of normal human testis show an expected low occurrence of apoptotic SPG (1 %) that increases to 3,4 % in peer samples exposed to VDT for the same period, with the appearance of apoptotic SPC (4,6 %). In samples from a thermically-impaired testis of the same subject the apoptotic occurrence of SPG is 2,6 % with 15,4 % for SPC after 24 h cultures. After 24 h exposure to VDT the apoptotic score is 7,6 % for SPG and 18,5 % for SPC in thermically impaired peer samples. With EMF-bioshields the apoptotic score for SPG is 0,8 % in normal 2,2 % for SPG and 13,8 % for SPC in T-impaired peer-samples. NMRS of the cultures fluids show a proportional production of lactate, corresponding to the different degrees of histopathological impairment of the samples. IVOS (Integrated Visual Optic System) analysis of sperm samples from thermically-impaired, not-repaired and repaired testes exposed to VDT shows sensible variations on straightness (STR), linearity (LIN) and lateral head displacement (LHD) parameters. To evaluate the thermic and non-thermic potential bioeffects of VDT on human spermatogenesis the specificity, the sensitivity and the reproducibility of the biological models on one side and the specificity of the methodologies on the other side must be provided. (author)

  1. Mutagenic adaptive response to high-LET radiation in human lymphoblastoid cells exposed to X-rays.

    Science.gov (United States)

    Varès, Guillaume; Wang, Bing; Tanaka, Kaoru; Kakimoto, Ayana; Eguchi-Kasai, Kyomi; Nenoi, Mitsuru

    2011-01-10

    The ability of cells to adapt low-dose or low-dose rate radiation is well known. High-LET radiation has unique characteristics, and the data concerning low doses effects and high-LET radiation remain fragmented. In this study, we assessed in vitro the ability of low doses of X-rays to induce an adaptive response (AR) to a subsequent challenging dose of heavy-ion radiation. Lymphoblastoid cells (TK6, AHH-1, NH32) were exposed to priming 0.02-0.1Gy X-rays, followed 6h later by challenging 1Gy heavy-ion radiation (carbon-ion: 20 and 40keV/μm, neon-ion: 150keV/μm). Pre-exposure of p53-competent cells resulted in decreased mutation frequencies at hypoxanthine-guanine phosphoribosyl transferase locus and different H2AX phosphorylation kinetics, as compared to cells exposed to challenging radiation alone. This phenomenon did not seem to be linked with cell cycle effects or radiation-induced apoptosis. Taken together, our results suggested the existence of an AR to mutagenic effects of heavy-ion radiation in lymphoblastoid cells and the involvement of double-strand break repair mechanisms. Copyright © 2010 Elsevier B.V. All rights reserved.

  2. Physiological and biochemical responses of small fish exposed to Athabasca oil sands sediment

    International Nuclear Information System (INIS)

    Tetrault, G.R.; Environment Canada, Burlington, ON; McMaster, M.E.; Dixon, D.G.; Parrott, J.L.

    2002-01-01

    A study was conducted to determine the influence of naturally occurring oil sands related compounds on the reproductive function and hepatic responses of fish. Wild fish, both exposed and unexposed to the compounds in question, were collected along with sediments for laboratory testing. The study showed that in vitro gonadal incubation levels of steroid production were lower at the tributary sites within the oil sands deposits. One indicator of exposure to oil sands related compounds (hepatic 7-ethoxyresorufin-O-deethylase activity) was shown to be 5 times higher at the same sites. In addition, slimy sculpin were exposed to sediment samples from the Steepbank River site for 4 to 8 days to evaluate the absorption of the indicator. The indicator in exposed fish was found to be comparable to that measured in fish native to the oil sands area. The study was not capable of predicting an altered ability of gonadal tissue of exposed fish to produce steroid hormones in vitro. It was concluded that future development could compromise the reproductive health of fish in the area

  3. Effects of the material composition in the TL curves of alkaline halides with Eu2+ exposed to β radiation

    International Nuclear Information System (INIS)

    Perez S, R.; Piters, T.; Aceves, R.; Rodriguez M, R.

    2006-01-01

    The solid state dosemeters plays a very important paper in the growing use of the ionizing radiation. When being increased the use of the radioactive isotopes in the medicine and in the industry, the necessity to have materials but adapted in each case it has increased. To synthesize such materials, it is necessary to enlarge the knowledge on the paper that its play the physical characteristics of the crystals such as the crystalline structure, the lattice constant, imbibed nano structures, dislocations, ions size, electronic states of the ions, etc., on the effects of the ionizing radiation. In the past its have been carried out many studies approaching these problems in some materials, but we consider that its are insufficient before the challenges of the applications. To contribute to the understanding of these effects, we present a study focused to alkaline halide crystals impurified with Eu 2+ ions, making an analysis on the paper that its play a) the ions concentration of Eu 2+ in KBr: Eu 2+ , b) the different sites of trapping of electrons and holes in KBr: Eu 2+ , KCl: Eu 2+ , RbBr:Eu 2+ , RbCl: Eu 2+ and c) the composition of the crystalline solid solutions KCl x Br 1-X : Eu 2+ and RbCI x KBr 1-x : Eu 2+ on the thermoluminescence curve when these materials are exposed to small dose of β irradiation. The increase in the concentration of Eu 2+ ions produces a smaller relative intensity of the emissions of high temperature for a given dose and it is found that in a RbCl x KBr 1-x : Eu 2+ with the greater/smaller concentration of Cl - ions, the temperature of the characteristic emission is near to the 453/373 K. The composition x of halogenous ions and not the one of alkaline in the crystalline solid solution dominates the landslide of the temperature of the emission. (Author)

  4. Interaction of solutions containing phenothiazines exposed to laser radiation with materials surfaces, in view of biomedical applications

    NARCIS (Netherlands)

    Simon, A.; Alexandru, T.; Boni, M.; Damian, V.; Stoicu, A.; Dutschk, Victoria; Pascu, M.L.

    2014-01-01

    Phenothiazine drugs - chlorpromazine (CPZ), promazine (PZ) and promethazine (PMZ) - were exposed to 266 nm (fourth harmonic of the Nd:YAG pulsed laser radiation) in order to be modified at molecular level and to produce an enhancement of their antibacterial activity. The irradiated samples were

  5. Method and means of reducing erosion of components of plasma devices exposed to helium and hydrogen isotope radiation

    International Nuclear Information System (INIS)

    Kaminsky, M.S.; Das, S.K.; Rossing, T.D.

    1977-01-01

    Surfaces of components of plasma devices exposed to radiation by atoms or ions of helium or isotopes of hydrogen can be protected from damage due to blistering by shielding the surfaces with a structure formed by sintering a powder of aluminum or beryllium and its oxide or by coating the surfaces with such a sintered metal powder. 7 claims

  6. Crosstalk between MAV and MEP pathways in vitro grape plants exposed to UV-B radiation

    International Nuclear Information System (INIS)

    Gil, M.; Bottini, R.; Piccoli, P.; Pontin, M.

    2010-01-01

    The synthesis of terpenoids from IPP (isopentenyl diphosphate) proceeds in plants throughout two pathways, the MVA (mevalonic acid) in cytosol and the MEP (2-C-methyl-D-erythritol 4-phosphate) in plastids. Ultraviolet-B (UV-B) radiation induced the synthesis of terpenes in in vitro grape plants according to the fluence rate. Low intensity UV-B promoted the MVA pathway while high intensity UV-B stimulated the MEP pathway. Mevastatin is known to inhibit the enzyme HMG-CoA reductase blocking terpene synthesis in cytosol. In vitro plants growing 45 days under 16 h-photoperiod (100 μmol m - 2 s - 1) were fed at the apex with mevastatin and then exposed to an UV-B dose administrated at two intensities: low UV-B (8.25 μW cm - 2,16 h) or high UV-B (33 μW cm - 2,4 h). Methanol: chloroform extracts were analyzed by GC-EIMS and compared with controls without mevastatin. Levels of γ-Sitosterol and Stigmasterol were significantly increased under low intensity UV-B in the controls. The plants treated with the inhibitor showed a significant decrease of both sterols and a decrease in the plastidial terpenes but sterols were higher under UV-B. These results suggest an IPP crosstalk between the MAV and MEP pathways under restrictive conditions. (authors)

  7. Viability of quail embryos and nestlings from the eggs exposed to gamma-radiation, vibration and storage

    International Nuclear Information System (INIS)

    Mishchenko, V.F.; Shafirkin, A.V.

    1986-01-01

    The viability of quail embryos and nestlings from the incubation eggs exposed (in) to gamma-radiation at a dose of 300 cGy and stored for 15 days or (ii) to gamma-radiation at a dose of 300 cGy and stored for 30 days or (iii) to vibration with the acute egg end oriented contrary to the vibration front and stored for 30 days did not decrease as compared to that of the controls stored for the same time period. The viability diminished if the radiation dose was increased to 600-1200 cGy of if the egg orientation during vibration was changed

  8. Effect of natural β-carotene supplementation in children exposed to radiation from the Chernobyl accident

    International Nuclear Information System (INIS)

    Ben-Amotz, A.; Yatziv, S.; Sela, M.; Greenberg, S.; Rachmilevich, B.; Shwarzman, M.; Weshler, Z.

    1998-01-01

    Attempts were made to evaluate 709 children (324 boys and 385 girls) who had been exposed long-term to different doses of radiation during and after the Chernobyl accident and had moved to Israel between 1990 and 1994. Upon arrival, all of them underwent a check-up for most common clinical disorders and were then divided into three groups according to their residences (distance from the reactor) and the level of irradiation exposure: no radiation, 2 , and >5 Ci/m 2 , respectively. Blood serum analyses for total carotenoids, retinol, α-tocopherol and oxidized conjugated dienes in 262 of the children showed increased HPLC levels of conjugated dienes, indicating increased levels of oxidation of in vivo blood lipids in children from the contaminated areas. The levels were higher in girls than in boys. Some 57 boys and 42 girls were given a basal diet with a diurnal supplementation of 40 mg natural 9-cis and all-trans equal isomer mixture β-carotene in a capsulated powder form of the alga Dunaliella bardawil, for a period of 3 months. Blood serum analyses were regularly conducted before supplementation to determine the baseline effect of radiation exposure to the children, after 1 and 3 months of natural β-carotene supplementation. After supplementation, the levels of the oxidized conjugated dienes decreased in the children's sera without any significant changes in the level of total carotenoids, retinol or α-tocopherol. Other common blood biochemicals were within the normal range for all tests and no statistical differences before or after supplementation of β-carotene were noted. High pressure liquid chromatography (HPLC) analyses for carotenoids in the blood detected mainly oxycarotenoids, and to a lesser extent, all-trans β-carotene, α-carotene, but not 9-cis β-carotene. The results suggest that irradiation increases the susceptibility of lipids to oxidation in the Chernobyl children and that natural β-carotene may act as an in vivo lipophilic antioxidant

  9. Inelastic contribution to the radiation damage of Cu and Ni exposed to charged particles

    International Nuclear Information System (INIS)

    Ibragimov, Sh.Sh.; Ibragimov, R.M.; Kirsanov, V.V.; Reutov, V.F.

    1975-01-01

    The formation of radiation damage through primary knock-on atoms (PKA) in elastic interactions, and heavy nuclear reaction products in irradiation of Cu by 30 MeV protons and of Ni by 50 MeV α-particles is studied. Distributions of the mean free path of bombarding particles, of concentration and average energy of PKA and recoil nuclei are obtained. The characteristic feature of these distributions is a substantial superiority of the PKA concentration while thier average energy is much less than that of recoil nuclei. A comparison of numbers of atoms displaced by elastic and inelastic interactions is made. The contribution of inelastic processes to the total number of displacements per target atom is shown to be small for the (α, Ni) system and notable for the (p, Cu) system within the range of the mean free path where the proton energy is mainly going into ionization

  10. Implantation and Evaluation of a Training Program in Radiation Protection of the Exposed Workers in our Hospital

    International Nuclear Information System (INIS)

    Gil Agudo, A.; Ruiz Rodriguez, J. C.; Zapata Jimenez, J. C.; Munoz Cuevas, R.; Gil Tomas, S.

    2004-01-01

    The object of this work is to introduce the training program in Radiation Protection implemented in our Hospital, and its evaluation and follow-up. Material AND Methods: The training program in Radiation Protection implanted by the Department of Radiation Protection in the Hospital de la Ribera consists of three types of training modalities: Annual Seminars: applicable to all the exposed workers and divided in a general part and a specific one for each area; Informative lectures: applicable to a specific department, deal with specific issues of interest without predetermined frequency; Individualised training: applicable to pregnant, new workers, job moves and duties change. The follow-up of the program is carried out by mean of inquiries about general and site-specific knowledge on radiation protection. Results The results of the inquiries are analysed and related with the continuous training program. Conclusion: It is remarkable that departments with workers without academic training in radiation protection (Intensive Care Unit, Surgery, Endoscopy,) need a more dedicated training. The results confirm the validity of the three training modalities: The annual seminar provides a continuous training to all exposed workers; the informative lecture is useful to handle immediately issues of current interest in a specific department and the individual training are useful to acquire specific knowledge about radiation risks and radiation protection rules in new working situations. (Author)

  11. Strategies for Discovery of Small Molecule Radiation Protectors and Radiation Mitigators

    Energy Technology Data Exchange (ETDEWEB)

    Greenberger, Joel S.; Clump, David [Radiation Oncology Department, University of Pittsburgh Cancer Institute, Pittsburgh, PA (United States); Kagan, Valerian [Environmental and Occupational Health Department, University of Pittsburgh, Pittsburgh, PA (United States); Bayir, Hülya [Critical Care Medicine Department, University of Pittsburgh Medical Center, Pittsburgh, PA (United States); Lazo, John S. [Pharmacology Department, University of Virginia, Charlottesville, VA (United States); Wipf, Peter [Department of Chemistry, Accelerated Chemical Discovery Center, University of Pittsburgh, Pittsburgh, PA (United States); Li, Song; Gao, Xiang [Pharmaceutical Science Department, University of Pittsburgh, Pittsburgh, PA (United States); Epperly, Michael W., E-mail: greenbergerjs@upmc.edu [Radiation Oncology Department, University of Pittsburgh Cancer Institute, Pittsburgh, PA (United States)

    2012-01-13

    Mitochondrial targeted radiation damage protectors (delivered prior to irradiation) and mitigators (delivered after irradiation, but before the appearance of symptoms associated with radiation syndrome) have been a recent focus in drug discovery for (1) normal tissue radiation protection during fractionated radiotherapy, and (2) radiation terrorism counter measures. Several categories of such molecules have been discovered: nitroxide-linked hybrid molecules, including GS-nitroxide, GS-nitric oxide synthase inhibitors, p53/mdm2/mdm4 inhibitors, and pharmaceutical agents including inhibitors of the phosphoinositide-3-kinase pathway and the anti-seizure medicine, carbamazepine. Evaluation of potential new radiation dose modifying molecules to protect normal tissue includes: clonogenic radiation survival curves, assays for apoptosis and DNA repair, and irradiation-induced depletion of antioxidant stores. Studies of organ specific radioprotection and in total body irradiation-induced hematopoietic syndrome in the mouse model for protection/mitigation facilitate rational means by which to move candidate small molecule drugs along the drug discovery pipeline into clinical development.

  12. Participation of different genes in the ruptures repair of double chain in Escherichia coli stumps exposed to gamma radiation

    International Nuclear Information System (INIS)

    Serment G, J. H.; Martinez M, E.; Alcantara D, D.

    2013-01-01

    All living organisms are naturally exposed to radiation from different sources. Ionizing radiation produces a plethora of lesions upon DNA that can be categorized as single and double strand breaks and base damage. Among them, unrepaired double strand breaks (Dbs) have the greatest biological significance, since they are responsible of cell death. In Escherichia coli this kind of lesions are repaired mostly by homologous recombination. In this work the participation of some recombination genes in the repair of Dbs is evaluated. Escherichia coli defective strains were exposed to gamma radiation and incubated for different periods in ideal conditions. Both micro electrophoresis and pulse field gel electrophoresis techniques were used to evaluate the kinetics of repair of such lesions, reflecting the importance of each defective gene in the process. (Author)

  13. Effects of chronic exposure to low doses of ionizing radiation on the reproductive performance and outcome of an exposed population

    International Nuclear Information System (INIS)

    Mannino, J.A.

    1978-01-01

    This study was designed to test the hypothesis that low doses of ionizing radiation (cumulative dose less than 5.0 rads/yr) effects the reproductive history and/or outcome of a human population. Medically-related personnel who were exposed to low doses of radiation in the course of their employment were compared with medically-related personnel who were not routinely exposed to ionizing radiation. Each population consisted of 3000 persons from the states of Michigan and Ohio. Reproductive performance, history, and outcome of each sample population was compared statistically. Nineteen congenital defects and 47 postnatal defects were recorded for conceptions of the non-exposed population and 50 congenital defects and 83 postnatal defects were recorded for the exposed group. These groups were further broken down as to whether conception took place before, during, or after exposure and the results statistically analyzed. It was found that the exposure population had greater than expected numbers of postnatal defects and less than expected numbers of normal conceptions

  14. Chemical and optical changes in freshwater dissolved organic matter exposed to solar radiation

    Science.gov (United States)

    Osburn, C.L.; Morris, D.P.; Thorn, K.A.; Moeller, R.E.

    2001-01-01

    We studied the chemical and optical changes in the dissolved organic matter (DOM) from two freshwater lakes and a Sphagnum bog after exposure to solar radiation. Stable carbon isotopes and solid-state 13C-NMR spectra of DOM were used together with optical and chemical data to interpret results from experimental exposures of DOM to sunlight and from seasonal observations of two lakes in northeastern Pennsylvania. Solar photochemical oxidation of humic-rich bog DOM to smaller LMW compounds and to DIC was inferred from losses of UV absorbance, optical indices of molecular weight and changes in DOM chemistry. Experimentally, we observed a 1.2??? enrichment in ??13C and a 47% loss in aromatic C functionality in bog DOM samples exposed to solar UVR. Similar results were observed in the surface waters of both lakes. In late summer hypolimnetic water in humic Lake Lacawac, we observed 3 to 4.5??? enrichments in ??13C and a 30% increase in aromatic C relative to early spring values during spring mixing. These changes coincided with increases in molecular weight and UV absorbance. Anaerobic conditions of the hypolimnion in Lake Lacawac suggest that microbial metabolism may be turning over allochthonous C introduced during spring mixing, as well as autochthonous C. This metabolic activity produces HMW DOM during the summer, which is photochemically labile and isotopically distinct from allochthonous DOM or autochthonous DOM. These results suggest both photooxidation of allochthonous DOM in the epilimnion and autotrophic production of DOM by bacteria in the hypolimnion cause seasonal trends in the UV absorbance of lakes.

  15. Thyroid Dose Estimates for a Cohort of Belarusian Children Exposed to Radiation from the Chernobyl Accident

    Science.gov (United States)

    Drozdovitch, Vladimir; Minenko, Victor; Khrouch, Valeri; Leshcheva, Svetlana; Gavrilin, Yury; Khrutchinsky, Arkady; Kukhta, Tatiana; Kutsen, Semion; Luckyanov, Nickolas; Shinkarev, Sergey; Tretyakevich, Sergey; Trofimik, Sergey; Voillequé, Paul; Bouville, André

    2013-01-01

    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. PMID:23560632

  16. Adaptive response of yeast cultures (Saccharomyces Cerevisiae) exposed to low dose of gamma radiation

    International Nuclear Information System (INIS)

    Kulcsar, Agnes; Savu, D.; Petcu, I.; Gherasim, Raluca

    2003-01-01

    The present study was planned as follows: (i) setting up of standard experimental conditions for investigation of radio-induced adaptive response in lower Eucaryotes; (ii) developing of procedures for synchronizing Saccharomyces cerevisiae X 310 D cell cultures and cell cycle stages monitoring; (iii) investigation of gamma (Co-60) and UV irradiation effects on the viability of synchronized and non-synchronized cell cultures of Saccharomyces cerevisiae; the effects were correlated with the cell density and cell cycle stage; (iv) study of the adaptive response induced by irradiation and setting up of the experimental conditions for which this response is optimized. The irradiations were performed by using a Co-60 with doses of 10 2 - 10 4 Gy and dose rates ranging from 2.2 x 10 2 Gy/h to 8.7 x 10 3 Gy/h. The study of radioinduced adaptive response was performed by applying a pre-irradiation treatment of 100-500 Gy, followed by challenge doses of 2-4 kGy delivered at different time intervals, ranging from 1 h to 4 h. The survival rate of synchronized and non-synchronized cultures as a function of exposure dose shows an exponential decay shape. No difference in viability of the cells occurred between synchronized and non-synchronized cultures. The pre-irradiation of cells with 100 and 200 Gy were most efficient to induce an adaptive response for the yeast cells. In this stage of work we proved the occurrence of the adaptive response in the case of synchronized yeast cultures exposed to gamma radiation. The results will be used in the future to investigate the dependence of this response on the cell cycle and the possibility to induce such a response by a low level electromagnetic field. (authors)

  17. Strategies for Discovery of Small Molecule Radiation Protectors and Radiation Mitigators

    Directory of Open Access Journals (Sweden)

    Joel S Greenberger

    2012-01-01

    Full Text Available Mitochondrial targeted radiation damage protectors (delivered prior to irradiation and mitigators (delivered after irradiation, but before the appearance of symptoms associated with radiation syndrome have been a recent focus in drug discovery for 1 normal tissue radiation protection during fractionated radiotherapy, and 2 radiation terrorism counter measures. Several categories of such molecules have been discovered: nitroxide-linked hybrid molecules, including GS-nitroxide, GS-nitric oxide synthase inhibitors, p53/mdm2/mdm4 inhibitors, and pharmaceutical agents including inhibitors of the phosphoinositide-3-kinase pathway and the anti-seizure medicine, carbamazepine. Evaluation of potential new irradiation dose modifying molecules to protect normal tissue includes: clonagenic radiation survival curves; assays for apoptosis and DNA repair, and irradiation-induced depletion of antioxidant stores. Studies of organ specific radioprotection and in total body irradiation-induced hematopoietic syndrome in the mouse model for protection/mitigation facilitate rational means by which to move candidate small molecule drugs along the drug discovery pipeline into clinical development.

  18. Changes in viability of two Antarctic marine bacteria exposed to solar radiation in the water column: influence of vertical mixing

    International Nuclear Information System (INIS)

    Hernandez, E.A.

    2007-01-01

    The effect of UV radiation on two Antarctic marine bacterial strains (UVps and UVvi) was studied in the water column of Potter Cove (South Shetland, Antarctica). Quartz flasks were filled with the bacterial suspensions and exposed to solar radiation at 0 m, 1 m and 3 m depth. Assays using flasks exposed to direct solar radiation and others using flasks covered with/by interferential filters which discriminate between UVA and UVB, were performed. In other assays, a vertical mixing of 4 m/h was simulated. Both strains showed a significant decrease in viability (expressed as colony - forming units) when exposed to a surface UVB dose of 8.4 kJ m -2 . Studies with interferential filters showed a significant decrease at 0 and 1 m depth under both UV treatments. The UVps strain appeared to be more sensitive to UVB than to UVA. Damage produced by UVB was attenuated by the vertical mixing when the surface UVB dose was 4.8 kJ m -2 . This effect was not observed when surface UVB dose was 7.7 kJ m -2 . These results show that the negative effect caused by UVB radiation on the bacterio plankton would be significant only in the first meter of water column of the Antarctic coastal waters with high levels of suspended particulate material. (author) [es

  19. A study of the indices of the peripheral blood of women, professionally exposed to low doses of ionizing radiation

    International Nuclear Information System (INIS)

    Bliznakov, V.; Mikhajlov, M.A.; Serafimov, A.; Nikolov, A.

    1979-01-01

    The peripheral blood content in women, which, due to their occupation are exposed to low dose ionizing radiation effect, has been investigated. One hundred and ten women from 20 to 50 years of age and occupation service in a sphere of ionizing radiation from 6 months to 4 years (an average length of 2,5 years) were examined. The unequal external gamma irradiation was the fundamental factor of the radiation effect under conditions of occupational media. The mean annual dose did never exceed the maximum permissible limits. As control, a group of 106 clinically healthy women of the same age and working in the industry but not exposed to radiation effect, was formed. Hemoglobin quantity, erythrocytes and leukocytes number, differential count of leukocytes and thrombocytes number were analyzed. Not any statistically significant differences (p > 0,05) between the mean values of the studied parameters of the control group and this one of women exposed to occupational irradiation were observed. This analysis of the hematological parameters represents the first stage of the already undertaken dynamic examination of the health status of a new and relatively stable contingent of occupationally irradiated persons. (A.B.)

  20. Surgical aspects of radiation enteritis of the small bowel

    International Nuclear Information System (INIS)

    Wobbes, T.; Verschueren, R.C.; Lubbers, E.J.; Jansen, W.; Paping, R.H.

    1984-01-01

    Injury to the small bowel is one of the tragic complications of radiotherapy. We performed a retrospective analysis of patients operated upon for stenosis, perforation, fistulization, and chronic blood loss of the small bowel after radiotherapy for multiple malignant diseases. In the period 1970 to 1982 in the Department of General Surgery of the St. Radboud University Hospital, Nijmegen, and the Department of Surgical Oncology of the State University, Groningen, 27 patients were treated surgically. Twenty patients presented with obstruction. In 17 patients a side-to-side ileotransversostomy was performed; in three the injured bowel was resected. Of the five patients with fistulization, three underwent a bypass procedure; in two cases the affected bowel was resected. In one patient with perforation, a resection was performed, as in a patient with chronic blood loss. Two of the 20 patients (10 per cent) in whom the diseased bowel was bypassed died postoperatively. Of the seven patients whose affected bowel was resected four (57 per cent) died of intra-abdominal sepsis. Management of the patient with chronic radiation enteritis is discussed. We conclude, on the basis of our experience, that in patients with obstruction and fistulization, a bypass procedure of the affected bowel is a safe method of treatment. In case of resection, the anastomosis should be performed during a second operation

  1. Surgical aspects of radiation enteritis of the small bowel

    Energy Technology Data Exchange (ETDEWEB)

    Wobbes, T.; Verschueren, R.C.; Lubbers, E.J.; Jansen, W.; Paping, R.H.

    1984-02-01

    Injury to the small bowel is one of the tragic complications of radiotherapy. We performed a retrospective analysis of patients operated upon for stenosis, perforation, fistulization, and chronic blood loss of the small bowel after radiotherapy for multiple malignant diseases. In the period 1970 to 1982 in the Department of General Surgery of the St. Radboud University Hospital, Nijmegen, and the Department of Surgical Oncology of the State University, Groningen, 27 patients were treated surgically. Twenty patients presented with obstruction. In 17 patients a side-to-side ileotransversostomy was performed; in three the injured bowel was resected. Of the five patients with fistulization, three underwent a bypass procedure; in two cases the affected bowel was resected. In one patient with perforation, a resection was performed, as in a patient with chronic blood loss. Two of the 20 patients (10 per cent) in whom the diseased bowel was bypassed died postoperatively. Of the seven patients whose affected bowel was resected four (57 per cent) died of intra-abdominal sepsis. Management of the patient with chronic radiation enteritis is discussed. We conclude, on the basis of our experience, that in patients with obstruction and fistulization, a bypass procedure of the affected bowel is a safe method of treatment. In case of resection, the anastomosis should be performed during a second operation.

  2. Is it possible to detect by peri-ungual capillaroscopy the micro-circulatory impact of ionizing radiation among radiation exposed physicians?

    International Nuclear Information System (INIS)

    Menez, C.

    2007-10-01

    The objective: evaluation of the peri-ungual capillaroscopy as diagnostic tool and screening of secondary infra clinical lesions to a chronic exposure to X ionizing radiation. Material and methods: the whole of personnel exposed of the Grenoble university hospital center, as well as a non exposed physician population chosen according to age criteria, had benefit of a peri-ungual capillaroscopy. An estimation of the exposure level was realised, allowing the constitution of exposure groups. Seven qualitative capillaroscopic variables were evaluated: dilatation, hemorrhages, edema, capillary rarefaction, tortuosity, capillary density and background color. Results: two homogenous populations in term of age: 32 exposed subjects, for essential cardiologists and interventional radiologists; 35 non exposed subjects. No statistically significant difference was enlightened, in the comparison of exposed- non exposed groups and in the comparison of the most exposed group to the control group. Discussion: the low statistical power of this study does not allow to conclude to the lack of inter group difference. This result disagrees with the literature, but these works are not easily comparable. Conclusion: the importance of the stake and the surveillance of the operators hands justifies the realisation of a multi centric great scope study. (N.C.)

  3. Immunizing potential of sporulated oocysts of Eimeria nieschulzi exposed to heat and 60Co gamma-radiation

    International Nuclear Information System (INIS)

    Conder, G.A.; Duszynski, D.W.

    1977-01-01

    Sporulated oocysts of Eimeria nieschulzi Dieben 1924, a rat coccidium, were exposed to radiation, heat, or both in an effort to attenuate the parasite. Moderate levels of each treatment or combination thereof attenuated the parasite, reduced pathogenesis (as judged by oocyst discharge during primary infection), and produced immunity to challenge when the oocysts were subsequently inoculated into rats. Thus, heat- and/or radiation-treated E. nieschulzi oocysts fed to rats could reduce pathogenesis during a primary infection and yet give good homologous protection

  4. Code of Nursing Practice for Staff Exposed to Ionizing Radiation (1984)

    International Nuclear Information System (INIS)

    1984-01-01

    This Code, published by the National Health and Medical Research Council and intended for nurses and auxiliary staff provides general guidance on radiation protection. The Code is supplementary to radiation control legislation relating to the use of ionizing radiation in medical practice. The principles established by the recommendations of the International Commission on Radiological Protection (ICRP) have been taken into account. (NEA) [fr

  5. The impact of humidity on evaporative cooling in small desert birds exposed to high air temperatures.

    Science.gov (United States)

    Gerson, Alexander R; Smith, Eric Krabbe; Smit, Ben; McKechnie, Andrew E; Wolf, Blair O

    2014-01-01

    Environmental temperatures that exceed body temperature (Tb) force endothermic animals to rely solely on evaporative cooling to dissipate heat. However, evaporative heat dissipation can be drastically reduced by environmental humidity, imposing a thermoregulatory challenge. The goal of this study was to investigate the effects of humidity on the thermoregulation of desert birds and to compare the sensitivity of cutaneous and respiratory evaporation to reduced vapor density gradients. Rates of evaporative water loss, metabolic rate, and Tb were measured in birds exposed to humidities ranging from ∼2 to 30 g H2O m(-3) (0%-100% relative humidity at 30°C) at air temperatures between 44° and 56°C. In sociable weavers, a species that dissipates heat primarily through panting, rates of evaporative water loss were inhibited by as much as 36% by high humidity at 48°C, and these birds showed a high degree of hyperthermia. At lower temperatures (40°-44°C), evaporative water loss was largely unaffected by humidity in this species. In Namaqua doves, which primarily use cutaneous evaporation, increasing humidity reduced rates of evaporative water loss, but overall rates of water loss were lower than those observed in sociable weavers. Our data suggest that cutaneous evaporation is more efficient than panting, requiring less water to maintain Tb at a given temperature, but panting appears less sensitive to humidity over the air temperature range investigated here.

  6. Prospective study of total cholesterol amount in the blood of the persons exposed to ionizing radiation due to Chernobyl accident

    International Nuclear Information System (INIS)

    Chobot'ko, G.M.

    1998-01-01

    The blood of the men aged 20-59 residing in Kyiv after the accident and that of the participants of the accident clean-up aged 25-55 has been studying for 10 years. The nature of the observed changes in blood cholesterol amount is atherogenic, which should be taken into account when taking preventive and therapeutic measures in the persons exposed to different dosed of ionizing radiation

  7. Kinetics of hemopoietic stem cells and survival of mice treated with hydroxyurea and exposed to prolonged γ-radiation

    International Nuclear Information System (INIS)

    Chertkov, K.S.; Rogozkin, V.D.; Dikovenko, E.A.; Mosina, Z.M.

    1979-01-01

    A study was made of radioprotective efficiency of hydroxyurea in relation to mice exposed to prolonged 137 Cs-γ-radiation. It was found that a 30-day survival rate, under optimal conditions of treatment with hydroxyurea, was more than 40 per cent higher than that of the controls. The protective effect of hydroxyurea was manifested at the level of hemopoietic stem cells due to a quicker onset and accelerated rate of the repopulation process

  8. Contribution of modern medical imaging technology to radiation health effects in exposed populations

    International Nuclear Information System (INIS)

    Fabrikant, J.I.

    1980-11-01

    The introduction of technically-advanced imaging systems in medicine carries with it potential health hazards, particularly from ionizing and nonionizing radiation exposure of human populations. This paper will discuss what we know and what we do not know about the health effects of low-level radiation, how the risks of radiation-induced health effects may be estimated, the sources of the scientific data, the dose-response models used, the uncertainties which limit precision of estimation of excess health risks from low-level radiation, and what the implications might be for radiation protection in medicine and public health policy

  9. Investigation of mutagenic effects in personnel occupationally exposed to ionizing radiation in Brazil

    International Nuclear Information System (INIS)

    Cunha Junior, Luiz Raimundo Campos da Silva e

    2015-01-01

    Ionizing radiation (IR) are present in most of the early diagnosis of a multitude of diseases, many cancers are included, and have the characteristic of a quick and accurate diagnosis, and often cheaper. The use of this type of energy but requires specific care protection, since the IR has a characteristic of altering the genetic material through mutations. The radiology area operators in hospitals are the class of workers who are exposed more directly and thus are targets of investigations that may assist in understanding the interaction of IR with the biological material, in addition to assisting these professionals in requirement radiological protection We collected 73 samples of individuals working in various radiology departments in five hospitals in four different states in Brazil (Sao Paulo, Minas Gerais, Rio Grande do Sul and Para). The selection criteria for participation were: at least 18 years old and 2 years in the profession, not alcoholic or smoker, not taking drugs. For cytogenetic analysis were performed the comet test and micronucleus, and chromosome aberration study. This study was approved by ethics committee All the samples were compared to individuals of the same age and gender who have not gone through any kind of radiological examination in the last 6 months. When compared with the control, MN tests and AC showed a total damage, using the t test, the database and SPSS BioEstat. The comet assay showed a higher level of damage compared to controls (0.84 0,47). the average age was established and made relationship between gender and age of the participants, the more damage levels in females compared to males. Individuals aged over 45 years also showed a higher level of damage when compared with the age. A factor to be taken into consideration is that the population of Porto Alegre present a lower level of damage compared to other groups, and most likely this event due to the use of DR equipment Direct conversion. The Belo Horizonte and Ribeirao

  10. Radiation structurization borosilicates in the region of small dozes

    International Nuclear Information System (INIS)

    Gadzhieva, N.N.; Melikova, S.Z.

    2007-01-01

    Full text: Borosilicates are one of perspective materials who are characterized by high thermal and radiating stability. Owing to these properties they are widely applied as constructional materials in reactor technologies. The structural condition of a bor in crystal compounds is characterized by two coordination numbers- three and and four. Change of this condition speaks also original properties borosilicate. Studying influence is actual γ-irradiations in the region of rather small dozes on ability change coordination of a B in borosilicate. In the given work results of IR-spectroscopic researches initial and radiation-structured borosilicates are presented. With this purpose were investigated borosilicates with maintenance B 2 O 3 in SiO 2 equal 0.5; 1; 1.5; 3; 5 and 10 mas.%, received by a method of sedimentation. Samples irradiated γ-quanta on an isotope source 60 Co with capacity of a doze dD γ /dt=0.80 Gy/s. The absorbed doze made D γ ∼0.5-50 kGy. IR-spectra of reflection initial and γ-irradiated tablets borosilicates measured on spectrophotometer Specord 71 IR (Carl Zeiss) at a room temperature. Optical density of the bands corresponding trigonal and tetrahedric - coordination atoms of a bor and their parity at the various mass maintenance of boric anhydride in SiO 2 before and after γ-irradiation. The absorption bands of asymmetric stretching vibration BO 3 and BO 4 groupings in structure of B 2 O 3 /SiO 2 have maxima at ν=1320 (ν as BO 3 ) and 980 cm -1 (ν as BO 4 ). Studying dose has shown dependences D 1320 /D 980 , that in the region of rather small dozes 0.5 γ 1320 /D 980 of optical densities trigonal and tetrahedric coordination a B it is established, that at the contain B 2 O 3 in SiO 2 /B 2 O 3 ∼1.5 mas.% maximal introduction B 3+ in a lattice oxide silicon is observed

  11. Radiation Synovectomy: an effective alternative treatment for inflamed small joints.

    Science.gov (United States)

    Karavida, N; Notopoulos, A

    2010-01-01

    An inflamed painful joint is one of the most common indications for the patient to be referred to a rheumatologist or an orthopedician. In relation to the aetiology, the therapeutic approach might be systemic, local or a combination of them in some cases, always with the thought of balancing risk with benefit for the patient. In all cases, independently of the cause, the goal of therapy is to improve the quality of life through the reduction of pain, improvement of mobility and preservation of function. Nuclear Medicine has to offer Radiosynoviorthesis, an effective alternative procedure for treating inflamed small joints. Various radionuclides are available for radiosynoviorthesis. Their selection depends on the size of the joint to be treated. Small joints are mainly treated with [169Er] erbium under a fluoroscopic or sonographic guidance, usually with a simultaneous instillation of a corticoid. Candidates for radiosynoviorthesis should have been under a six-month systemic treatment without encouraging results or should have undergone at least one unsuccessful intra-articular injection of a long acting glucocorticoid. Since 1973, when [169Er] erbium was firstly suggested as a therapeutic agent for radiosynoviorthesis of the finger joints, there has been quite enough experience in its' application. It has been found to be cost effective in providing long term relief of pain and deformity of the inflamed joints in comparison to other therapeutic approaches. Additionally, there is no radiation risk and can be performed on an out patient basis. Therefore it can stand as an effective alternative procedure for treating early stages of chronic synovitis in RA (rheumatoid arthritis) patients, with minor damage of the cartilage and the adjacent bones, and for synovitis secondary to inflammatory arthropathies.

  12. Effect of low dose radiation in lymphocytes from children exposed to ionizing radiation after the Chernobyl accident. Cytogenetic, chromosome painting, GPA and adaptive response studies

    International Nuclear Information System (INIS)

    Padovani, L.; Appolloni, M.; Anzidei, P.; Spano, M.; Stronati, L.; Testa, A.; Mauro, F.

    1997-01-01

    The present study concerns the monitoring of some children coming from Byelorussian, Ukrainian and Russian republics, exposed to the fall-out, or to the initial acute dose of radiation with the aim of assessing the effects of ionizing radiation on human health and of verifying the persisting of chromosomal damage several years after the accident. Both structural chromosomes damage (conventional cytogenetic and chromosome painting) and molecular mutation (GPA) have been investigated, moreover the possible induction of an adaptive response has been tested. (author)

  13. The study of the effects of ionizing and non-ionizing radiations on birth weight of newborns to exposed mothers.

    Science.gov (United States)

    Mortazavi, S M J; Shirazi, K R; Mortazavi, G

    2013-01-01

    Life evolved in an environment filled with a wide variety of ionizing and non-ionizing radiation. It was previously reported that medical exposures to pregnant women increases the risk of low birth weight. This study intends to investigate the relationship between exposure to ionizing and non-ionizing radiation and the risk of low birth weight. One thousand two hundred mothers with their first-term labor (vaginal or cesarean) whose newborns' history had been registered in neonates' screening program in Shiraz were interviewed and surveyed. Data collection was performed by the assessment of mother's history of radiography before and during pregnancy, physical examination of the mother for height and weight and weighing and examining the newborn for any diagnosis of disease and anomalies. There were no statistical significant differences between the mean weight of newborns whose mothers had been exposed to some common sources of ionizing and non-ionizing radiations such as dental or non dental radiographies, mobile phone, cordless phone and cathode ray tube (CRT) and those of non-exposed mothers. The findings of this study cast doubt on previous reports, which indicated that exposure to ionizing radiation during pregnancy increased the risk of low birth weight.

  14. Clinical observation of a 16-year-old female exposed to radiation in utero: follow-up after the Shanxi Xinzhou radiation accident

    International Nuclear Information System (INIS)

    Liang Li; Zhang Zhaohui; Chen Sen; Ma Liwen; Chen Yamai; Zhang Shuluan; Jia Tingzhen; Liu Ying; Liu Qingjie; Su Xu; Qin Bin; Wang Zuoyuan

    2011-01-01

    A follow-up study of the late effects of intrauterine exposure to irradiation has been made on a 16-year-old girl whose mother was exposed to external 60 Co irradiation during the Xinzhou radiation accident 16 years previously. The outcomes of the general medical examinations, conventional chromosome aberration analyses and fluorescence in situ hybridisation (FISH) are presented and the China-revised Wechsler Intelligence Scale for Children (C W ISC) was used to identify her IQ level, which was well below normal for her age. The biological dose of the radiation to which she was exposed when she was in her mother's uterus was inferred to be 1.85 Gy. Although there is no evidence of any other developmental changes or tumour induction at this stage in her life, the child's total intelligence level does appear to have been affected. (note)

  15. Analysis of the health of a group exposed to low doses of ionizing radiation; Analisis de salud en un grupo expuesto a dosis bajas de radiaciones ionizantes

    Energy Technology Data Exchange (ETDEWEB)

    Diaz Ledesma, F [Servicio Medico de Tecnatom, SA Madrid (Spain); Crespo, H [Hospital Gregorio Maranon de Madrid, Madrid (Spain)

    1997-11-01

    In order to evaluate the effects of exposure to low radiation doses, the health status of professional staff exposed to ionizing radiation is investigated. Based on archived material of medical and radiation exposure records taken over a time span of 13 years, a variety of medical parameters are explored. Findings of surveys made are given. (author). 1 fig.

  16. Reliability of semiconductor and gas-filled diodes for over-voltage protection exposed to ionizing radiation

    Directory of Open Access Journals (Sweden)

    Stanković Koviljka

    2009-01-01

    Full Text Available The wide-spread use of semiconductor and gas-filled diodes for non-linear over-voltage protection results in a variety of possible working conditions. It is therefore essential to have a thorough insight into their reliability in exploitation environments which imply exposure to ionizing radiation. The aim of this paper is to investigate the influence of irradiation on over-voltage diode characteristics by exposing the diodes to californium-252 combined neutron/gamma radiation field. The irradiation of semiconductor over-voltage diodes causes severe degradation of their protection characteristics. On the other hand, gas-filled over-voltage diodes exhibit a temporal improvement of performance. The results are presented with the accompanying theoretical interpretations of the observed changes in over-voltage diode behaviour, based on the interaction of radiation with materials constituting the diodes.

  17. Quantitative dose-response of growth and development in Arabidopsis thaliana exposed to chronic gamma-radiation

    International Nuclear Information System (INIS)

    Daly, K.; Thompson, K.H.

    1975-01-01

    The response of Arabidopsis thaliana (L.) Heynh. (Cruciferae) to a gradient of chronic gamma-radiation was examined under field conditions. Plants that were initially introduced to the gamma field as dry seeds received exposures of 1.34 to 18 800R/20 hour day from the time of seed germination. Regression analysis demonstrated a significant, but non-linear, response for three variables, number of seedlings emerging, number of plants flowering, and plant volume; the response of a fourth variable, number of leaves per plant, was not related to daily exposure. LD 50 values ranged from 66R/20 hour day for plant volume to 1231R/20 hour day for seedling emergence. Flowering and plant volume were the most sensitive indicators of radiation exposure. The demonstration of a variable threshold at low levels of exposure indicates that in nature A. thaliana may be exposed to environmental radiation throughout its life-cycle without significant modification of growth or development. (author)

  18. Review of NCRP radiation dose limit for embryo and fetus in occupationally-exposed women - approved 1977

    International Nuclear Information System (INIS)

    Anon.

    1978-01-01

    On the basis of the current review, the NCRP has decided to make no change in the current recommendation of its radiation dose limit to the unborn. The NCRP recommendation is restated here as follows: During the entire gestation period, the maximum permissible dose equivalent to the embryo-fetus from occupational exposure of the expectant mother should be 0.5 rem. Since the preparation of the 1971 report there has been no new evidence concerning teratogenic or carcinogenic effects of irradiation of the embryo-fetus that would justify a change in the limit in either direction. It is implicit in this position and recommendation that women who can reasonably be expected to be pregnant should not, in certain instances, be exposed to the same radiation environment as women who are not considered fertile or as men. This applies particularly to conditions where radiation workers can receive dose equivalents of 0.5 rem or more in short periods

  19. Persistence of translocations detected by means of fluorescence in situ hybridization in peripheral lymphocytes of accidentally exposed radiation workers

    International Nuclear Information System (INIS)

    Pressl, S.; Stephan, G.

    1997-01-01

    The translocation frequency in lymphocytes of radiation workers accidentally exposed a number of years earlier was determined by means of fluorescence in situ hybridization. Chromosomes 2, 4 and 8 were painted, and simultaneously the centromeres. The genomic frequency of translocations is between 1.7 and 17.9 per 1000 cells. This variation is not significantly different from the level in healthy control subjects. Therefore, no radiation exposure could be detected retrospectively. On the other hand, the frequency of dicentrics in these radiation workers measured by means of fluorescence plus Giemsa staining shortly after the exposure was significantly increased, and whole body doses between 0.2 and 0.3 Gy could be calculated. Consequently, it would seem that dicentrics measured shortly after an exposure are a more sensitive indicator than translocations which are determined years later. (author)

  20. Chromosome aberration analysis in persons exposed to low-level radiation from the JCO criticality accident in Tokai-mura

    International Nuclear Information System (INIS)

    Sasaki, Masao S.; Hayata, Isamu; Kamada, Nanao; Kodama, Yoshiaki; Kodama, Seiji

    2001-01-01

    Chromosome aberrations were studied in peripheral blood lymphocytes of 43 persons who were exposed to low-level radiation of mixed neutrons and γ-rays resulting from the JCO criticality accident. When the age-adjusted frequencies of dicentric and ring chromosomes were compared with the dose calibration curve established in vitro for 60 Co γ-rays as a reference radiation, a significant correlation was observed between the chromosomally estimated doses and the documented doses evaluated by physical means. The regression coefficient of the chromosomal doses against the documented doses, 1.47±0.33, indicates that the relative biological effectiveness of fission neutrons at low doses is considerably higher than that currently adopted in the radiation protection standard. (author)

  1. The Xenon Test Chamber Q-SUN® for testing realistic tolerances of fungi exposed to simulated full spectrum solar radiation.

    Science.gov (United States)

    Dias, Luciana P; Araújo, Claudinéia A S; Pupin, Breno; Ferreira, Paulo C; Braga, Gilberto Ú L; Rangel, Drauzio E N

    2018-06-01

    The low survival of insect-pathogenic fungi when used for insect control in agriculture is mainly due to the deleterious effects of ultraviolet radiation and heat from solar irradiation. In this study, conidia of 15 species of entomopathogenic fungi were exposed to simulated full-spectrum solar radiation emitted by a Xenon Test Chamber Q-SUN XE-3-HC 340S (Q-LAB ® Corporation, Westlake, OH, USA), which very closely simulates full-spectrum solar radiation. A dendrogram obtained from cluster analyses, based on lethal time 50 % and 90 % calculated by Probit analyses, separated the fungi into three clusters: cluster 3 contains species with highest tolerance to simulated full-spectrum solar radiation, included Metarhizium acridum, Cladosporium herbarum, and Trichothecium roseum with LT 50  > 200 min irradiation. Cluster 2 contains eight species with moderate UV tolerance: Aschersonia aleyrodis, Isaria fumosorosea, Mariannaea pruinosa, Metarhizium anisopliae, Metarhizium brunneum, Metarhizium robertsii, Simplicillium lanosoniveum, and Torrubiella homopterorum with LT 50 between 120 and 150 min irradiation. The four species in cluster 1 had the lowest UV tolerance: Lecanicillium aphanocladii, Beauveria bassiana, Tolypocladium cylindrosporum, and Tolypocladium inflatum with LT 50  solar radiation before. We conclude that the equipment provided an excellent tool for testing realistic tolerances of fungi to full-spectrum solar radiation of microbial agents for insect biological control in agriculture. Copyright © 2018 British Mycological Society. Published by Elsevier Ltd. All rights reserved.

  2. Response of antioxidant defense system to laser radiation apical meristem of Isatis indigotica seedlings exposed to UV-B.

    Science.gov (United States)

    Chen, Yi-Ping

    2009-07-01

    To determine the response of antioxidant defense system to laser radiation apical meristem of Isatis indigotica seedlings, Isatis indigotica seedlings were subjected to UV-B radiation (10.08 kJ m(-2)) for 8 h day(-1) for 8 days (PAR, 220 micromol m(-2) s(-1)) and then exposed to He-Ne laser radiation (633 nm; 5.23 mW mm(-2); beam diameter: 1.5 mm) for 5 min each day without ambient light radiation. Changes in free radical elimination systems were measured, the results indicate that: (1) UV-B radiation enhanced the concentration of Malondialdahyde (MDA) and decreased the activities of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) in seedlings compared with the control. The concentration of MDA was decreased and the activities of SOD, CAT and POD were increased when seedlings were subjected to elevated UV-B damage followed by laser; (2) the concentration of UV absorbing compounds and proline were increased progressively with UV-B irradiation, laser irradiation and He-Ne laser irradiation plus UV-B irradiation compared with the control. These results suggest that laser radiation has an active function in repairing UV-B-induced lesions in seedlings.

  3. Methodology for estimating radiation dose rates to freshwater biota exposed to radionuclides in the environment

    International Nuclear Information System (INIS)

    Blaylock, B.G.; Frank, M.L.; O'Neal, B.R.

    1993-08-01

    The purpose of this report is to present a methodology for evaluating the potential for aquatic biota to incur effects from exposure to chronic low-level radiation in the environment. Aquatic organisms inhabiting an environment contaminated with radioactivity receive external radiation from radionuclides in water, sediment, and from other biota such as vegetation. Aquatic organisms receive internal radiation from radionuclides ingested via food and water and, in some cases, from radionuclides absorbed through the skin and respiratory organs. Dose rate equations, which have been developed previously, are presented for estimating the radiation dose rate to representative aquatic organisms from alpha, beta, and gamma irradiation from external and internal sources. Tables containing parameter values for calculating radiation doses from selected alpha, beta, and gamma emitters are presented in the appendix to facilitate dose rate calculations. The risk of detrimental effects to aquatic biota from radiation exposure is evaluated by comparing the calculated radiation dose rate to biota to the U.S. Department of Energy's (DOE's) recommended dose rate limit of 0.4 mGy h -1 (1 rad d -1 ). A dose rate no greater than 0.4 mGy h -1 to the most sensitive organisms should ensure the protection of populations of aquatic organisms. DOE's recommended dose rate is based on a number of published reviews on the effects of radiation on aquatic organisms that are summarized in the National Council on Radiation Protection and Measurements Report No. 109 (NCRP 1991). DOE recommends that if the results of radiological models or dosimetric measurements indicate that a radiation dose rate of 0. 1 mGy h -1 will be exceeded, then a more detailed evaluation of the potential ecological consequences of radiation exposure to endemic populations should be conducted

  4. Supervision of professional personnel exposed to ionizing radiation (X-rays); Surveillance du personnel professionnellement expose aux radiations ionisantes (rayons X)

    Energy Technology Data Exchange (ETDEWEB)

    Chalabreysse, J [Commissariat a l' Energie Atomique, Pierrelatte (France). Centre d' Etudes Nucleaires

    1964-10-01

    After a short introduction giving the physical characteristics and the possible interactions of X-rays, this report considers in more detail the basis of the dosimetry and the units used. Taking into account the dangers of irradiation and the professional norms applicable, the report reviews the physical methods (collective and individual dosimetry) and the biological method (based on the systematic supervision of the hemogram) which are used to ensure that these professional norms an respected. As an example the influence is studied of repeated doses of X-rays on the hemogram of X-ray operators when the individual radiation levels are known through dosimetric films. Two processes are used: one considers the mean values (irradiation and average hemogram for each person), the other requires the use of an electronic computer and uses each haematological variable as a function of the monthly or cumulative doses; it gives correlation coefficients for the different variables. In conclusion, the results obtained are compared to those conventionally accepted, and the validity of the hemogram is estimated as a criterion for the supervision. (author) [French] Apres avoir rappele brievement les caracteristiques physiques et le mode d'interaction des rayons X, ce rapport reprend les bases de la dosimetrie et les unites qui sont utilisees. Considerant les dangers entraines par une irradiation et rappelant les normes professionnelles, il envisage les methodes physiques (dosimetrie collective et individuelle) et la methode biologique (basee sur la surveillance systematique de l'hemogramme), utilisees pour faire respecter ces normes professionnelles. En application est etudiee l'influence, sur l'hemogramme des manipulateurs radio, des rayons X subis a doses repetees, connaissant les niveaux individuels d'irradiation gr e au film dosimetrique. Deux procedes sont utilises, l'un considere les valeurs moyennes (irradiation et hemogramme moyens pour chaque individu), l'autre faisant

  5. Supervision of professional personnel exposed to ionizing radiation (X-rays); Surveillance du personnel professionnellement expose aux radiations ionisantes (rayons X)

    Energy Technology Data Exchange (ETDEWEB)

    Chalabreysse, J. [Commissariat a l' Energie Atomique, Pierrelatte (France). Centre d' Etudes Nucleaires

    1964-10-01

    After a short introduction giving the physical characteristics and the possible interactions of X-rays, this report considers in more detail the basis of the dosimetry and the units used. Taking into account the dangers of irradiation and the professional norms applicable, the report reviews the physical methods (collective and individual dosimetry) and the biological method (based on the systematic supervision of the hemogram) which are used to ensure that these professional norms an respected. As an example the influence is studied of repeated doses of X-rays on the hemogram of X-ray operators when the individual radiation levels are known through dosimetric films. Two processes are used: one considers the mean values (irradiation and average hemogram for each person), the other requires the use of an electronic computer and uses each haematological variable as a function of the monthly or cumulative doses; it gives correlation coefficients for the different variables. In conclusion, the results obtained are compared to those conventionally accepted, and the validity of the hemogram is estimated as a criterion for the supervision. (author) [French] Apres avoir rappele brievement les caracteristiques physiques et le mode d'interaction des rayons X, ce rapport reprend les bases de la dosimetrie et les unites qui sont utilisees. Considerant les dangers entraines par une irradiation et rappelant les normes professionnelles, il envisage les methodes physiques (dosimetrie collective et individuelle) et la methode biologique (basee sur la surveillance systematique de l'hemogramme), utilisees pour faire respecter ces normes professionnelles. En application est etudiee l'influence, sur l'hemogramme des manipulateurs radio, des rayons X subis a doses repetees, connaissant les niveaux individuels d'irradiation gr e au film dosimetrique. Deux procedes sont utilises, l'un considere les valeurs moyennes (irradiation et hemogramme moyens pour

  6. G2 repair and chromosomal damage in lymphocytes from workers occupationally exposed to low-level ionizing radiation

    Directory of Open Access Journals (Sweden)

    J PINCHEIRA

    1999-01-01

    Full Text Available The effect of the G2 repair of chromosomal damage in lymphocytes from workers exposed to low levels of X- or g-rays was evaluated. Samples of peripheral blood were collected from 15 radiation workers, 20 subjects working in radiodiagnostics, and 30 healthy control donors. Chromosomal aberrations (CA were evaluated by scoring the presence of chromatid and isochromatid breaks, dicentric and ring chromosomes in lymphocytes with/without 5mM caffeine plus 3mM-aminobenzamide (3-AB treatment during G2. Our results showed that the mean value of basal aberrations in lymphocytes from exposed workers was higher than in control cells (p< 0.001. The chromosomal damage in G2, detected with caffeine plus 3-AB treatment was higher than the basal damage (untreated conditions, both in control and exposed populations (p< 0.05. In the exposed workers group, the mean value of chromosomal abnormalities in G2 was higher than in the control (p< 0.0001. No correlation was found between the frequency of chromosome type of aberrations (basal or in G2, and the absorbed dose. Nevertheless, significant correlation coefficients (p< 0.05 between absorbed dose and basal aberrations yield (r = 0.430 or in G2 (r = 0.448 were detected when chromatid breaks were included in the total aberrations yield. Under this latter condition no significant effect of age, years of employment or smoking habit on the chromosomal aberrations yield was detected. However, analysis of the relationship between basal aberrations yield and the efficiency of G2 repair mechanisms, defined as the percentage of chromosomal lesions repaired in G2, showed a significant correlation coefficient (r = -0.802; p< 0.001. These results suggest that in addition to the absorbed dose, the individual G2 repair efficiency may be another important factor affecting the chromosomal aberrations yield detected in workers exposed to low-level ionizing radiation

  7. Exposed persons at the Chernobyl Atomic Power Station accident: acute radiation effects

    International Nuclear Information System (INIS)

    Gus'kova, A.K.; Baranov, A.E.; Barabanova, A.V.

    1987-01-01

    Observation made over 115 patients with acute radiation sickness due to exposure external γ- and β-rays confirmed high efficiency of the earlier proposed principles of prognostication of the degree of severity by clinical manifestations of the primary disease response and those of separate syndromes, using the methods of hematological and cytogenetic analyses. Out of 115 victims, 56 persons had radiation burns (RB), 17 intestinal syndrome (IS), 80 - oropharengeal syndrome (ORS), 7 - interstitial radiation pneumonitis (IRP). In thanatogenesis, of prime importance were: RB (more than 40% of the body surface) - 19 persons and IRP - 7 persons. A severe course of intestinal and oropharengeal syndromes was combined with other fatal manifestations of radiation injury. Early isolation of patients (2-4 stages), selective decontamination of the intestine, prescription of a wide spectrum antibiotics, antimycotic and antiviral drugs, as well as γ-globulin could practically remove the risk of the development of fatal infectious complications during a medullary andtransitory forms of radiation sickness

  8. Monitoring and assessment of individual doses of occupationally exposed workers due to external radiation

    International Nuclear Information System (INIS)

    Kitaw, S. T.

    2015-05-01

    Exposure to external radiation occurs in many occupations. Any exposure to ionizing radiation has the tendency to change the biochemical make-up of the human body which may result in biological health effects of ionizing radiation. This study reviews the monitoring and assessment of external radiation doses in industrial radiography using thermoluminescence and direct reading dosimeters. Poor handling procedures such as inadequate engineering control of equipment, safety culture, management, and inadequate assessment and monitoring of doses are the causes of most of the reported cases of exposure to external radiation in industrial radiography. Occupational exposure data in industrial radiography from UNSCEAR report 2008 was discussed and recommendations were made to regulatory authorities, operating organizations and radiographers. (au)

  9. TBT toxicity on a natural planktonic assemblage exposed to enhanced ultraviolet-B radiation

    Energy Technology Data Exchange (ETDEWEB)

    Sargian, Peggy [Institut des Sciences de la Mer de Rimouski (ISMER), Universite du Quebec a Rimouski, 310, Allee des Ursulines, Rimouski, Que., G5L 3A1 (Canada)]. E-mail: peggy_sargian@uqar.qc.ca; Pelletier, Emilien [Institut des Sciences de la Mer de Rimouski (ISMER), Universite du Quebec a Rimouski, 310, Allee des Ursulines, Rimouski, Que., G5L 3A1 (Canada); Mostajir, Behzad [Reseaux trophiques pelagiques (GDR 2476) et Ecologie Microbienne des milieux Aquatiques, UMR 5119 Ecosystemes lagunaires, CNRS-Universite Montpellier II, Case 093, 34095 Montpellier Cedex 5 (France); Ferreyra, Gustavo A. [Institut des Sciences de la Mer de Rimouski (ISMER), Universite du Quebec a Rimouski, 310, Allee des Ursulines, Rimouski, Que., G5L 3A1 (Canada); Instituto Antartico Argentino (IAA), Cerrito 1248 (C1010AAZ), Buenos Aires (Argentina); Demers, Serge [Institut des Sciences de la Mer de Rimouski (ISMER), Universite du Quebec a Rimouski, 310, Allee des Ursulines, Rimouski, Que., G5L 3A1 (Canada)

    2005-07-01

    A microcosm approach was designed to study the combined effects of tributyltin (TBT) from antifouling paints and ultraviolet-B radiation (UVBR: 280-320 nm), on a natural planktonic assemblage (<150 {mu}m) isolated from the St. Lawrence Estuary at the end of the springtime. Microcosms (9 l, cylindrical Teflon[reg] bags, 75 cm height x 25 cm width) were immersed in the water column of mesocosms (1800 l, polyethylene bags, 2.3 m depth) and exposed to two different UVBR regimes: natural ambient UVBR (NUVBR), and enhanced level of UVBR (HUVBR). During consecutive 5 days, effects of TBT (120 ng l{sup -1}) and enhanced UVBR (giving a biologically weighted UVBR 2.15-fold higher than natural light condition) were monitored in the samples coming from following treatments: (i) NUVBR light condition without TBT (NUVBR) (ii) NUVBR light condition with TBT-added (NUVBR + TBT) (iii) HUVBR light condition without TBT (HUVBR) and (iv) HUVBR light condition with TBT-added (HUVBR + TBT). Each treatment was conducted in triplicate microcosms. Different parameters were then measured during 5 days, including TBT analysis, bacterial abundance and productivity, phytoplankton abundance, cellular characteristics and growth rates, as well as in vivo chlorophyll a (Chl a) fluorescence. Following TBT addition (NUVBR + TBT treatment), Chl a concentrations never exceeded 1 {mu}g l{sup -1} whereas final values as high as 54 {mu}g l{sup -1} were observed in TBT-free treatments (NUVBR and HUVBR). TBT addition resulted also in the lost of fluorescence signal of the maximum efficiency of the photosystem II in phytoplankton assemblage. TBT toxicity caused on phytoplankton <20 {mu}m an increase of mean cell size and changes in shape reflected a drastic disturbance of the cell cycle leading to an inhibition of the apparent growth rate. These negative effects of TBT resulted in a final abundance of phytoplankton <20 {mu}m of 591 {+-} 35 cells ml{sup -1} in NUVBR + TBT relative to NUVBR treatment (i

  10. Radiation exposure and examination time during enteroclysis and small bowel follow-through

    International Nuclear Information System (INIS)

    Thoeni, R.F.; Gould, R.G.

    1989-01-01

    The authors have investigated radiation exposures and total examination and fluoroscopy times in enterolysis and small-bowel-follow-through (SBFT). Enteroclysis was performed in 25 patients and SBFT in another 25 (17 with UGI/SBFT and 8 with SBFT alone), with 5 TLD dosimeters placed in areas of the back exposed to primary x-rays during fluoroscopy, spot, and overhead radiography. Skin entry exposures, fluoroscopy, and total examination times in enteroclysis were compared to those in SBFTs. Biphasic enteroclyis was performed, with an average of 18 radiographs per study, SBFT with 16, and UGI/SBFT with 23. Indications and pathology for enteroclysis and SBFT were similar. Detailed findings are presented. The authors conclude that total examination time for enteroclysis is two to three times shorter and skin entry exposure is less than two to three times higher than for SBFT. Higher radiation exposure of enteroclysis should be weighted against very short examination times and reported high accuracy in deciding between enteroclysis and SBFT

  11. Qualitative evaluation of the DNA degradation in plague insects exposed to gamma radiation

    International Nuclear Information System (INIS)

    Ortega, Yuriko; Agapito, Juan; Vargas, Johnny; Vivanco, Monica; Martinez, Norberta

    2014-01-01

    Insects produce large losses in stored grain depending on the type of cereal and storage time and other factors. The rice weevil Sitophilus oryzae L and the false flour beetle Tribolium confusum are important pests of stored grain. The study aimed to qualitatively evaluate the effect of gamma radiation on the DNA of two species of insect pests from samples stored Chullpi and white corn infested with adult weevils. Samples were treated with radiation doses of 100, 400, 1000 and 2000 Gy and DNA extraction was obtained by three methods: TNES-urea, CTAB and NaOH. The DNA damage induced by gamma radiation in weevils was determined by gel electrophoresis. As a result, it was found that exposure of adult weevils to a radiation dose of 100 Gy and 400 caused an average mortality of the insects, showing a degree of resistance to gamma radiation. However, radiation doses of 1000 and 2000 Gy caused 100 % mortality of insects. Preliminary results show that DNA damage is proportional to the amount of gamma radiation. (authors).

  12. Delayed radiation injury of gut-exposed and gut-shielded mice. II. The decrement in life span

    International Nuclear Information System (INIS)

    Spalding, J.F.; Archuleta, R.F.; Prine, J.R.

    1978-01-01

    Two mouse strains (RF/J and C57B1/6J) were exposed to x-ray doses totaling 400, 800, and 1200 rad. Total doses were given in 200-rad fractions at 7-day intervals to the whole body, gut only, or bone tissue with the gut shielded. Animals were anesthetized during exposure. Two control groups were used. A sham control group was anesthetized but not exposed to x rays, and another control group received neither anesthesia nor x-radiation. All mice were retained in a standard laboratory environment for observations on life span and histopathology at death. Life shortening was observed in all irradiated groups of strain RF/J mice and was attributed primarily to an increase in incidence and/or earlier onset of neoplasia. Life shortening was observed in the C57B1/6J whole-body exposed mice, but the effect appeared to be noncarcinogenic. Shielding of the bone or gut tissue proved to have a 100% sparing effect in strain C57 mice and none in strain RF mice. In both mouse strains, the sham control groups (anesthetized but not irradiated) showed approximately 8% life shortening below the non-anesthetized control groups and increased incidences of neoplasia of approximately 40%, suggesting that sodium pentabarbital may be as carcinogenic as x-radiation

  13. Design and dosimetry of small animal radiation facilities

    Science.gov (United States)

    Rodriguez, Manuel R.

    The aim of this work was to develop an irradiation system for radiobiology studies. We designed a novel image-guided micro-irradiator capable of partial-body zebrafish embryo irradiation. The radiation source is a 50 kV photon beam from a miniature x-ray source (Xoft Inc., CA). The source is inserted in a cylindrical brass collimator, 3 cm in diameter and 3 cm in length. The collimator has a 1 mm-diameter pinhole along the longitudinal axis, which provides a well-focused beam with a sharp penumbra. A photodiode is installed at one exit of the pinhole collimator to monitor the photon dose rate. The source with the collimator is attached under a movable table. A video camera, connected to the computer, is placed above the movable table to record position of the specimens in relation to the pinhole collimator. The captured images are analyzed, and the relative distances between the specimens and the pinhole are calculated. The coordinates are sent to the computer-controlled movable table to accurately position the specimens in the beam. Monte Carlo simulations were performed to characterize dosimetric properties of the system, to determine dosimetric sensitivity, and to help in the design. The image-guidance and high precision of the movable table enable very accurate specimen position. The beam monitoring system provides accurate, fast and easy dose determination. Portability and self-shielding make this system suitable for any radiobiology laboratory. This novel micro-irradiator is appropriate for partial irradiation of zebrafish embryos; however its potential use is much wider like irradiation of cell cultures or other small specimens.

  14. A morphological and cytological study of Petunia hybrida exposed to UV-B radiation

    International Nuclear Information System (INIS)

    Staxén, I.; Bornmann, J.F.

    1994-01-01

    The aim of this study was to investigate whether the cytoskeleton, and in particular the microtubular system, is affected by enhanced levels of ultraviolet-B (280–320 nm, 9 kJ m −2 day −1 biologically effective UV-B radiation) radiation in epidermal cells of Petunia x hybrida Vilm, isolated from leaves of plants grown under UV-B radiation and visible light. In addition, morphological changes during development were monitored. In a previous study microtubules were depolymerized and delays in the different stages of the cell cycle were found when protoplasts of Petunia were irradiated with UV-B radiation (Staxén et al. 1993. Protoplasma 173: 70–76). Thus it was of interest to ascertain whether the cytoskeleton would be similarly affected in an intact system. Assuming an effect of UV-B radiation on the microtubular system, we wished to determine whether this could be correlated to concomitant changes in leaf morphology. Plants of Petunia hybrida were grown in greenhouse conditions in the presence or absence of UV-B radiation. During the course of the experiment, samples were taken from young, expanding leaves and from older, fully expanded leaves and prepared for localization and analysis of microtubules from the adaxial epidermal cells. Morphology rather than the cytoskeleton was affected by UV radiation, despite the fact that the epidermal cytoskeleton would most likely be affected, since it is located in the cells which form the first intercepting layer for incident radiation. Morphological changes under UV-B radiation, as compared to those under control conditions, were reflected in earlier flowering and an increase in leaf number. Cell division was thus stimulated as was also evidenced from the increased leaf area. Our results indicate that the number of stomata differentiated on a leaf area basis was not altered although the number of stomata per epidermal cell was reduced. (author)

  15. Motor reactivity of animals exposed to ionizing radiation and treated with psychotropic drugs

    International Nuclear Information System (INIS)

    Szwaja, S.

    1978-01-01

    The influence of ionizing radiation on motor reactivity of animals and the influence of selected psychotropic drugs (fenactil, haloperidol, relanium) on the changes invoked by ionizing radiation were studied experimentally in rats whose motor reactivity was assessed on the basis of conditional reflexes. In unirradiated rats, fenactil and haloperidol, but not relanium, disordered positive conditional reactions. Roentgen irradiation of the rats with a single dose on the whole body caused a drop in positive conditional reactions. Relanium and fenactil enhanced psychomotor activity of rats after exposure to ionizing radiation. (author)

  16. Motor reactivity of animals exposed to ionizing radiation and treated with psychotropic drugs

    Energy Technology Data Exchange (ETDEWEB)

    Szwaja, S [Uniwersytet Jagiellonski, Krakow (Poland)

    1978-01-01

    The influence of ionizing radiation on motor reactivity of animals and the influence of selected psychotropic drugs (fenactil, haloperidol, relanium) on the changes invoked by ionizing radiation were studied experimentally in rats whose motor reactivity was assessed on the basis of conditional reflexes. In unirradiated rats, fenactil and haloperidol, but not relanium, disordered positive conditional reactions. Roentgen irradiation of the rats with a single dose on the whole body caused a drop in positive conditional reactions. Relanium and fenactil enhanced psychomotor activity of rats after exposure to ionizing radiation.

  17. Health effects in women exposed to low levels of ionizing radiation

    International Nuclear Information System (INIS)

    Fabrikant, J.I.

    1982-06-01

    There are three delayed health effects of radiation which appear at the present time to have importance to women in radiation protection. These are: (1) the probability of cancer-induction at low doses and low-dose rates; (2) the consideration of those cancers in women, notably the breast and the thyroid, attributable to radiation exposure; and (3) the probability of induction of developmental abnormalities in the newborn following low-dose exposure in utero. The bases for the concern over these effects are discussed

  18. Clinical and experimental investigation on small intestinal injury following radiation therapy for carcinoma of uterine cervix

    International Nuclear Information System (INIS)

    Asakura, Midori

    1977-01-01

    Radiation injury of the small bowel was observed in 6 of 460 patients with carcinoma of uterine cervix who were treated by radiation between April 1966 and December 1973 at Tokyo Women's Medical College, Department of Radiology. Three of these 6 patients were treated conservatively and the other 3 others underwent surgery but died subsequently. Clinically and surgically these 6 patients showed marked adhesions of intestinal loops, which may be accounted for by the radiation injury of the small bowel. Clinical experience has shown that it is necessary to use a small radiation field to decrease small bowel injury from radiation. An experiment using abdominal radiation in mice confirmed that LD sub(50/30) is larger with a center split, maintaining equal integral doses. In adult dogs, severe small bowel obstruction was observed with over 4000 rad irradiation. Small bowel injury was milder in case with center split, intracavitary irradiation, and small radiation field. It was concluded that center split is one of the methods of preventing radiation injury of the small bowel. (Evans, J.)

  19. A cytogenetic bio-monitoring of industrial radiographers occupationally exposed to low levels of ionizing radiation by using CBMN assay

    International Nuclear Information System (INIS)

    Shakeri, Mahsa; Changizi, Vahid; Zakeri, Farideh; Rajabpour, Mohammad Reza; Farshidpour, Mohammad Reza

    2017-01-01

    Industrial radiography is the process of using either gamma-emitting radionuclide sources or X-ray machines to examine the safety of industrial materials. The average annual effective dose in industrial radiography is one of the highest among radiation workers. The aim of this study was to investigate the cytogenetic effects of ionizing radiation in the peripheral blood lymphocytes of 60 industrial radiographers and 40 non-exposed individuals as the control group by using cytokinesis-block micronucleus (CBMN) assay. Totally, the frequencies of micronuclei (MN), nucleoplasmic bridges (NPBs) and nuclear buds (NBUDs) were significantly higher in the industrial radiographers than in the controls (p = 0.000). The mean MN frequency per 1000 binucleated cells in the industrial radiographers with last 5-y radiation dose of >100 mSv was significantly higher than those with ≤100 mSv (34.81 ± 12.70 vs. 26.33 ± 7.940, p = 0.024). The effect of age was observed in the control group and subjects with the age of >30 y showed significantly higher MN frequency compared with the subjects with the age of ≤30 y (9.45 ± 3.710 vs. 6.81 ± 3.050, p = 0.02). No obvious trend of increased MN as a function of either duration of employment or age or smoking status was observed in the industrial radiographers. The results show the increased levels of cytogenetic damages in the industrial radiographers. Even the workers exposed to the permissible doses are subjected to elevated frequencies of DNA damages. These findings confirm the importance of cytogenetic bio-monitoring program beside physical dosimetry, surveying radiation safety of equipment and periodic training of workers for improvement of safety and radiation protection. (authors)

  20. The Temperature of Various Surfaces Exposed to Solar Radiation: An Experiment.

    Science.gov (United States)

    Russell, Dena G.; Bartels, Richard A.

    1989-01-01

    Examines the effect of solar radiation on colored shingles. Describes the experimental procedure, results, and discussion. Presents a picture of the experimental arrangement and three graphs of data measured at different dates. (YP)

  1. A handbook for the triage, monitoring and treatment of people exposed to a malevolent use of radiation

    International Nuclear Information System (INIS)

    Rojas-Palma, Carlos; Meer, Klaas van der; Liland, Astrid; Jaworska, Alicja; Jerstad, Ane; Kruse, Phil; Smith, Karen; Rahola, Tua; Muikku, Maarit; Etherington, George; Perez, Maria del R.; Carr, Zhanat; Smagala, Genowefa

    2008-01-01

    In the aftermath of the Chernobyl accident European national emergency response plans have been tailored to deal with accidents at nuclear power plants. Several terrorist acts (World Trade Center, New York; Atocha train station, Madrid; suicide bombings) carried out by disaffected groups have shifted the focus to malevolent use of radiation. The radiation exposure can range from very low to substantial, possibly combined with conventional injuries. Therefore practicable tools are needed for an adequate response to such acts and more specifically to address European guidelines covering triage to treatment and long term follow up of exposed people. The European Commission through the EURATOM 6th Framework Programme is co-sponsoring the specific targeted research project TMT handbook. The main objective of this project is to produce a practicable handbook for the effective and timely triage, monitoring and treatment of people exposed to radiation following a malevolent act. This paper elaborates on the work being carried out and outlines the progress achieved prior to the deployment of the handbook in European national emergency response organizations, which are in the process of testing and evaluating the material through targeted emergency response exercises. The end of this paper includes some remarks on the challenges that need to be dealt with in order to achieve a sustainable development of what has been achieved through the lifetime of this project. (author)

  2. He-Ne laser treatment improves the photosynthetic efficiency of wheat exposed to enhanced UV-B radiation

    International Nuclear Information System (INIS)

    Chen, Huize; Han, Rong

    2014-01-01

    The level of ultraviolet-B (UV-B) radiation on the Earth’s surface has increased due to depletion of the ozone layer. Here, we explored the effects of continuous wave He-Ne laser irradiation (632 nm, 5 mW mm –2 , 2 min d –1 ) on the physiological indexes of wheat seedlings exposed to enhanced UV-B radiation (10 KJ m –2 d –1 ) at the early growth stages. Wheat seedlings were irradiated with enhanced UV-B, He-Ne laser treatment or a combination of the two. Enhanced UV-B radiation had deleterious effects on wheat photosynthesis parameters including photosystem II (chlorophyll content, Hill reaction, chlorophyll fluorescence parameters, electron transport rate (ETR), and yield), the thylakoid (optical absorption ability, cyclic photophosphorylation, Mg 2+ -ATPase, and Ca 2+ -ATPase) and some enzymes in the dark reaction (phosphoenolpyruvate carboxylase (PEPC), carbonic anhydrase (CA), malic dehydrogenase (MDH), and chlorophyllase). These parameters were improved in UV-B-exposed wheat treated with He-Ne laser irradiation; the parameters were near control levels and the enzyme activities increased, suggesting that He-Ne laser treatment partially alleviates the injury caused by enhanced UV-B irradiation. Furthermore, the use of He-Ne laser alone had a favourable effect on seedling photosynthesis compared with the control. Therefore, He-Ne laser irradiation can enhance the adaptation capacity of crops. (paper)

  3. The role of radiation regulatory agencies of the Republic of the Philippines in the education and training of workers occupationally exposed to radiation

    International Nuclear Information System (INIS)

    Perio Peralta, Agnette de

    2008-01-01

    In the Republic of the Philippines, there are two national radiation regulatory agencies. One is the Philippine Nuclear Research Institute (PNRI) which has the regulatory mandate over radioactive materials. The other one is the Bureau of Health Devices and Technology (BHDT) which has the regulatory mandate over radiation devices. Since a major requirement in regulating use of radiation sources is the appropriate qualification of the workers occupationally exposed to radiation, the paper discusses the strategies and activities of these two agencies to ensure that these workers have the necessary education and training to do their work properly. Some of these are the conduct of training courses in cooperation with the relevant professional societies, conduct of distance aided training in cooperation with the IAEA, initiation and active involvement in the establishment and continued existence of the masteral degree program in medical physics which was established with IAEA technical assistance, assistance to lawmakers in drafting pertinent legislation, and creation of joint technical working groups to ensure harmonization of standards and regulations, among others. The Philippines has adopted a national policy that users of radiation and radioactive materials have the primary responsibility for radiation safety. The PNRI and the BHDT have adopted strategies which have been very useful in the effective implementation of their regulations. (author)

  4. The Effect of Dose Rate on Composite Durability When Exposed to a Simulated Long-Term Lunar Radiation Environment

    Science.gov (United States)

    Rojdev, Kristina; O'Rourke, Mary Jane; Hill, Charles; Nutt, Steven; Atwell, William

    2011-01-01

    Human exploration of space beyond low Earth orbit (LEO) requires a safe living and working environment for crew. Composite materials are one type of material being investigated by NASA as a multi-functional structural approach to habitats for long-term use in space or on planetary surfaces with limited magnetic fields and atmosphere. These materials provide high strength with the potential for decreased weight and increased radiation protection of crew and electronics when compared with conventional aluminum structures. However, these materials have not been evaluated in a harsh radiation environment, as would be experienced outside of LEO or on a planetary surface. Thus, NASA has been investigating the durability of select composite materials in a long-term radiation environment. Previously, NASA exposed composite samples to a simulated, accelerated 30-year radiation treatment and tensile stresses similar to those of a habitat pressure vessel. The results showed evidence of potential surface oxidation and enhanced cross-linking of the matrix. As a follow-on study, we performed the same accelerated exposure alongside an exposure with a decreased dose rate. The slower dose ]rate is comparable to a realistic scenario, although still accelerated. Strain measurements were collected during exposure and showed that with a fastdose rate, the strain decreased with time, but with a slow ]dose rate, the strain increased with time. After the radiation exposures, samples were characterized via tensile tests, flexure tests, Fourier Transform Infrared Spectroscopy (FTIR), and Differential Scanning Calorimetry (DSC). The results of these tests will be discussed.

  5. Life-span radiation effects studies in prenatally and postnatally exposed beagle dogs at Colorado State University

    International Nuclear Information System (INIS)

    Benjamin, S.A.; Lee, A.C.; Angleton, G.M.; Jaenke, R.S.; Saunders, W.J.; Miller, G.K.; Brewster, R.D.

    1986-01-01

    The lifetime hazards associated with exposure to ionizing radiation during development are studied in 1680 beagle dogs given whole-body exposures to 60 Co gamma radiation. Eight groups of 120 dogs each received 20-R or 100-R exposures at 8, 28, or 55 days postcoitus (dpc) or at 2 days postpartum (dpp). In addition, exposures of 100 R were given to 120 dogs at 70 dpp and to 240 dogs at 365 dpp. An additional 360 dogs were sham exposed. Smaller groups of dogs were used to identify organs and tissues of particular sensitivity to radiation injury during development and to evaluate mechanisms of radiation injury. The research is concerned primarily with evaluating the role of age at exposure as a factor influencing response to radiation injury. As of December 31, 1982, of the 1680 dogs, 1058 were dead. Survivors ranged from 9.9 to 15 years of age. Through 10 years of age, no differences in survival were evident in any exposure groups. A variety of clinical, pathophysiologic, and pathologic responses have been studied. Irradiation during development has been found to be associated with abnormalities of skeletal, dental, and central nervous system development. Irradiation during ocular development has induced dysplastic and atrophic retinal lesions. Perinatal irradiation of the kidney has resulted in dysplasia, and, in animals receiving higher doses, significant chronic renal disease. The thymus gland, particularly thymic epithelium, has been found to be highly radiosensitive during fetal development

  6. Adaptive response in human blood lymphocytes exposed to non-ionizing radiofrequency fields: resistance to ionizing radiation-induced damage.

    Science.gov (United States)

    Sannino, Anna; Zeni, Olga; Romeo, Stefania; Massa, Rita; Gialanella, Giancarlo; Grossi, Gianfranco; Manti, Lorenzo; Vijayalaxmi; Scarfì, Maria Rosaria

    2014-03-01

    The aim of this preliminary investigation was to assess whether human peripheral blood lymphocytes which have been pre-exposed to non-ionizing radiofrequency fields exhibit an adaptive response (AR) by resisting the induction of genetic damage from subsequent exposure to ionizing radiation. Peripheral blood lymphocytes from four healthy donors were stimulated with phytohemagglutinin for 24 h and then exposed for 20 h to 1950 MHz radiofrequency fields (RF, adaptive dose, AD) at an average specific absorption rate of 0.3 W/kg. At 48 h, the cells were subjected to a challenge dose (CD) of 1.0 or 1.5 Gy X-irradiation (XR, challenge dose, CD). After a 72 h total culture period, cells were collected to examine the incidence of micronuclei (MN). There was a significant decrease in the number of MN in lymphocytes exposed to RF + XR (AD + CD) as compared with those subjected to XR alone (CD). These observations thus suggested a RF-induced AR and induction of resistance to subsequent damage from XR. There was variability between the donors in RF-induced AR. The data reported in our earlier investigations also indicated a similar induction of AR in human blood lymphocytes that had been pre-exposed to RF (AD) and subsequently treated with a chemical mutagen, mitomycin C (CD). Since XR and mitomycin-C induce different kinds of lesions in cellular DNA, further studies are required to understand the mechanism(s) involved in the RF-induced adaptive response.

  7. Blot hybridization analysis of TCR genes of T cells for five people exposed in a radiation accident

    International Nuclear Information System (INIS)

    Min Rui; Liu Benti; Cheng Tianmin; Yang Rujun; Meng Xiangshun; Xiao Jinsong

    1996-01-01

    Human lymphocyte total DNA was prepared in agarose plug by mixing cells with low melting agarose, and two restriction endonucleases were used for digestion of the total DNA with human α and β TCR cDNA probes. The total digested DNA from five people who were whole body exposed to 2.0-2.5 Gy ionizing radiation in an accident 4.5 years ago was hybridized by Southern blot method. The results showed that no obvious difference in hybridization bands was found between controls and the five victims when hybridizations were fulfilled in the total DNA which was digested by Hind III restriction endonuclease with both α and β probes. However, when the total DNA was digested with restriction endonuclease EcoR I and was hybridized with TCR α probe, four of the five exposed people showed a different hybridizing band pattern compared with the controls. The results are also discussed

  8. The problem of induced genomic instability in the child organism under conditions of long-term effect of small radiation doses

    International Nuclear Information System (INIS)

    Suskov, I.I.; Kuz'mina, N.S.

    2001-01-01

    The phenomenological aspects of the genomic instability induced in the descendants of the multi-divided cells having been exposed to the radiation are examined. It is demonstrated that the regularity of the genomic instability induction do not correspond to the classical conception of the radiation genetics (hit principle and target theory). The mechanisms and the biological significance of this new genetic phenomenon in the child organism under conditions of low-intensive effect of small-dose radiation and its connection with the state of health are discussed [ru

  9. Association between mortality and residual radiation in Nagasaki atomic bomb survivors exposed at long-distance from the hypocenter

    International Nuclear Information System (INIS)

    Kondo, Hisayoshi; Mine, Mariko; Yokota, Kenichi; Shibata, Yoshisada

    2012-01-01

    Mortality of Nagasaki A-bomb survivors exposed at 3 km or longer distance from the hypocenter was compared with that of those who were additionally exposed to residual radiation because of their entrance in the area at 1 km or closer to the center within 24 hr post explosion. The latter survivors (group I), 2,357 men with average age of 28.4 y and 2,618 women of 26.5 y at the exposure, were alive at 1970, and the former (group II, without exposure to residual radiation) was selected to match their numbers in sex, exposed distance, ages at exposure and at start of the follow-up study to those of group I. Follow-up was conducted from 1970 to 2007, and their total, malignant, cerebrovascular, cardiac and pneumonic deaths were observed. Cox proportional hazard model was used for estimation of mortality risk with covariates of sex and age at start of the study. The risk in group II was defined to be standard. Ages at start of the study were 53.3 and 51.4 y in men and women, respectively. Crude mortality tended to be higher in men of group I at ages of 40-49 and 50-59 y at start of the study. Hazard ratios of total and malignant tumor deaths in group I were 0.965 and 1.092, respectively, without statistic significance from group II and of other deaths, 0.982-0.999, also of statistic insignificance. Thus increased mortality due to residual radiation was not observed. (T.T.)

  10. A full-text english database of testimonies of those exposed to radiation near the Semipalatinsk nuclear test site, Kazakhstan

    OpenAIRE

    Matsuo, Masatsugu; Kawano, Noriyuki; Hirabayashi, Kyoko; Tooka, Yasuyuki; Apsalikov, Kazbek Negamatovich; Hoshi, Masaharu

    2004-01-01

    The present paper is a sequel to the initial report (Kawano et al 2003a) of the project for a full-text Japanese database of the testimonies of those exposed to radiation near the nuclear test site of Semipalatinsk, Kazakhstan. 139 testimonies were gathered in four villages near Semipalatinsk in 2002. We translated them into English from Russian and Kazakh, and created a full-text database by using a Latin script text retrieval program, TERESA. The present paper attempts at essentially the sa...

  11. Relationship between human respiratory reactivity and neutrophil metabolism under intermittent hypoxic influences in humans exposed to low-level radiation

    International Nuclear Information System (INIS)

    Serebrovskaya, T.V.; Oberenko, O.A.; Guseva, S.A.

    1996-01-01

    The group of 18 men exposed to radiation during amelioration work in the Chernobyl NPP was examined in the course of adaptation to intermittent hypoxia (rebreathing technique during 10 days of three dayly 5-7 min sessions with 15 min break). The starting level of ventilatory response to hypoxic stimulus (HVR) did not differ from the one in persons living in non-contaminated areas. This hypoxic training (HT) caused the increase of HVR, activity of NADPH-oxidase and cationic protein content in neutrophyls as well as various changes in mieloperoxidase activity. The correlation between respiration reactivity and deviations in neutrophil metabolism under HT was found. 14 refs., 2 figs

  12. Study about the sensibility in vitro of different strains of Vibrio cholera 01 exposed to 60 Co gamma radiation

    International Nuclear Information System (INIS)

    Moraes, Ivany Rodrigues de

    1998-01-01

    The presence of some microorganisms in food, or the metabolites originated during their own multiplication may bring several diseases to humans: intoxications and food borne infections. Among the agents that may cause those diseases, we find Vibrio cholerae 01. In this experiment, the studies are focused on the radiosensibility in vitro of four strains of V. cholerae 01, exposed to different doses of ionizing radiation of 60 Co. The results are compared with other data related to bacterial food borne diseases, including water. (author)

  13. Health status of the population in the Ukraine exposed to radiation as a result of the Chernobyl accident

    International Nuclear Information System (INIS)

    Romanenko, A.E.

    1992-01-01

    Evaluation of the health status of population exposed top radiation as a result of the Chernobyl accident is a problem of paramount importance. The results of demographic and epidemiologic surveys and clinical observations have shown that changes in the morbidity rates among children and adults at the strictly controlled districts in the Ukraine result not only from improved diagnostic service, but also from the after effects of the Chernobyl accident. A tendency to a growth of primary disease incidence among childrn and adults was established. Analysis of the results of follow-up of children has revealed an increased incidence of thyroid cancer. The accident caused an unfavourable demographic situation in the Republic

  14. MOSFET assessment of radiation dose delivered to mice using the Small Animal Radiation Research Platform (SARRP).

    Science.gov (United States)

    Ngwa, Wilfred; Korideck, Houari; Chin, Lee M; Makrigiorgos, G Mike; Berbeco, Ross I

    2011-12-01

    The Small Animal Radiation Research Platform (SARRP) is a novel isocentric irradiation system that enables state-of-the-art image-guided radiotherapy research to be performed with animal models. This paper reports the results obtained from investigations assessing the radiation dose delivered by the SARRP to different anatomical target volumes in mice. Surgically implanted metal oxide semiconductor field effect transistors (MOSFET) dosimeters were employed for the dose assessment. The results reveal differences between the calculated and measured dose of -3.5 to 0.5%, -5.2 to -0.7%, -3.9 to 0.5%, -5.9 to 2.5%, -5.5 to 0.5%, and -4.3 to 0% for the left kidney, liver, pancreas, prostate, left lung, and brain, respectively. Overall, the findings show less than 6% difference between the delivered and calculated dose, without tissue heterogeneity corrections. These results provide a useful assessment of the need for tissue heterogeneity corrections in SARRP dose calculations for clinically relevant tumor model sites.

  15. Incidence of primary hypothyroidism in patients exposed to therapeutic external beam radiation, where radiation portals include a part or whole of the thyroid gland

    Directory of Open Access Journals (Sweden)

    B A Laway

    2012-01-01

    Full Text Available Introduction: Hypothyroidism is a known consequence of external-beam radiotherapy to the neck encompassing a part or whole of the thyroid gland. In this non-randomized prospective study, we have tried to evaluate the response of the thyroid gland to radiation by assessing thyroid function before irradiation and at regular intervals after irradiation. Aims and Objectives: The aim of this study were to assess in the cancer patients, who were exposed to the therapeutic external beam radiation, where radiation portals include a part or whole of the thyroid gland: the incidence of primary hypothyroidism, the time required to become hypothyroid, any relation between the total dose for the development of hypothyroidism, and whether there are any patient or treatment-related factors that are predictive for the development of hypothyroidism, including the use of concurrent chemotherapy. Materials and Methods: This non-randomized, prospective study was conducted for a period of 2 years in which thyroid function was assessed in 59 patients (cases of head and neck cancer, breast cancer, lymphoma patients and other malignancies, who had received radiotherapy to the neck region. 59 euthyroid healthy patients (controls were also taken, who had not received the neck irradiation. These patients/controls were assessed periodically for 2 years. Results: The incidence of hypothyroidism after external beam radiation therapy (EBRT to neck where radiation portals include part or whole of the thyroid gland was 16.94%, seven cases had subclinical hypothyroidism (11.86% and three cases had clinical hypothyroidism (5.08%. Mean time for development of hypothyroidism was 4.5 months. There was no effect of age, gender, primary tumor site, radiation dose and chemotherapy, whether neoadjuvant or concurrent with the development of hypothyroidism. Conclusion: In summary, we found that thyroid dysfunction is a prevalent, yet easily treatable source of morbidity in patients

  16. Mode selection in electrical activities of myocardial cell exposed to electromagnetic radiation

    International Nuclear Information System (INIS)

    Ma, Jun; Wang, Ya; Wang, Chunni; Xu, Ying; Ren, Guodong

    2017-01-01

    Highlights: • Neuronal model under electromagnetic induction and radiation is set up; • The transition of electrical activities under electromagnetic radiation is discussed; • Dynamical response of encoding of neuron is discussed for possible mechanism of heart disease. - Abstract: Based on the Fitzhugh–Nagumo neuron model, the effect of electromagnetic induction is considered and external electromagnetic radiation is imposed to detect the mode transition of electrical activities in a myocardial cell. Appropriate dynamical and functional responses can be observed in the sampled series for membrane potentials by setting different feedback modulation on the membrane potential in presence of electromagnetic radiation. The electromagnetic radiation is described by a periodical forcing on the magnetic flux, and it is found that the response frequency can keep pace with the frequency of external forcing. However, mismatch of frequency occurs by further increasing the frequency of external forcing, it could account for the information encoding of neuron. The dynamical response could be associated with the magnetization and polarization of the media, thus the outputs of membrane potential can become quiescent and/or bursting as well.

  17. Competitive interaction in plant populations exposed to supplementary ultraviolet-B radiation

    International Nuclear Information System (INIS)

    Fox, F.M.; Caldwell, M.M.; Utah State Univ., Logan

    1978-01-01

    Changes in plant growth and competitive balance between pairs of competing species were documented as a result of supplementary ultraviolet-B radiation (principally in the 290-315 nm waveband) under field conditions. This component of the terrestrial solar spectrum would be intensified if the atmospheric ozone layer were reduced. A method for calculating and statistically analyzing relative crowding coefficients was developed and used to evaluate the competitive status of the species pairs sown in a modified replacement series. The effect of the supplementary UV-B irradiance was generally detrimental to plant growth, and was reflected in decreased leaf area, biomass, height and density as well as changes competitive balance for various species. For some species, interspecific competition apparently accentuated the effect of the UV-B radiation, while more intense intraspecific competition may have had the same effect for other species. A few species when grown in a situation of more severe mutual interspecific competition exhibited enhanced growth under the UV-B radiation treatment. This, however, was usually associated with a detrimental effect of the radiation, on its competitor and thus was likely the result of its improved competitive circumstance rather than a benefical physiological effect of the radiation. (orig.) [de

  18. New small devices for radiation detection: the Wee Pocket Chirper and the Portable Multichannel Analyzer

    International Nuclear Information System (INIS)

    Umbarger, C.J.

    1980-08-01

    Recent events have demonstrated the need for improved capability to monitor the exposure of workers to radiation and, in general, to identify and measure the many forms of radioactive materials found throughout the nuclear industry. Two radiation monitoring devices have been developed that are much smaller than existing instruments, yet exhibit superior performance and a longer battery life. The first instrument, the Wee Pocket Chirper, is a tiny, battery-powered warning device that chirps when exposed to radiation. The second instrument is a portable battery-powered, computer-based, multichannel analyzer that allows the user to examine radiation fields and to identify the types and amounts of radioactive materials present

  19. Disordered redox metabolism of brain cells in rats exposed to low doses of ionizing radiation or UHF electromagnetic radiation.

    Science.gov (United States)

    Burlaka, A P; Druzhyna, M O; Vovk, A V; Lukin, S М

    2016-12-01

    To investigate the changes of redox-state of mammalian brain cells as the critical factor of initiation and formation of radiation damage of biological structures in setting of continuous exposure to low doses of ionizing radiation or fractionated ultra high frequency electromagnetic radiation (UHF EMR) at non-thermal levels. The influence of low-intensity ionizing radiation was studied on outbred female rats kept for 1.5 years in the Chernobyl accident zone. The effects of total EMR in the UHF band of non-thermal spectrum were investigated on Wistar rats. The rate of formation of superoxide radicals and the rate of NO synthesis in mitochondria were determined by the EPR. After exposure to ionizing or UHF radiation, the levels of ubisemiquinone in brain tissue of rats decreased by 3 and 1.8 times, respectively. The content of NO-FeS-protein complexes in both groups increased significantly (р < 0.05). In the conditions of ionizing or EMR the rates of superoxide radical generation in electron-transport chain of brain cell mitochondria increased by 1.5- and 2-fold, respectively (р < 0.05). In brain tissue of rats kept in the Chernobyl zone, significant increase of NO content was registered; similar effect was observed in rats treated with UHFR (р < 0.05). The detected changes in the electron transport chain of mitochondria of brain cells upon low-intensity irradiation or UHF EMR cause the metabolic reprogramming of cell mitochondria that increases the rate of superoxide radical generation and nitric oxide, which may initiate the development of neurodegenerative diseases and cancer. This article is part of a Special Issue entitled "The Chornobyl Nuclear Accident: Thirty Years After".

  20. Learning From Trials on Radiation Dose in Non-Small Cell Lung Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Bradley, Jeffrey, E-mail: jbradley@wustl.edu [Department of Radiation Oncology, Washington University School of Medicine, St. Louis, Missouri (United States); Hu, Chen [Division of Oncology, Johns Hopkins University School of Medicine, Baltimore, Maryland (United States)

    2016-11-15

    In this issue of the International Journal of Radiation Oncology • Biology • Physics, Taylor et al present a meta-analysis of published data supporting 2 findings: (1) radiation dose escalation seems to benefit patients who receive radiation alone for non-small cell lung cancer; and (2) radiation dose escalation has a detrimental effect on overall survival in the setting of concurrent chemotherapy. The latter finding is supported by data but has perplexed the oncology community. Perhaps these findings are not perplexing at all. Perhaps it is simply another lesson in the major principle in radiation oncology, to minimize radiation dose to normal tissues.

  1. Fabrication of new phosphors of NaCl: Cu and their thermoluminescent characterization to be exposed to beta radiation

    International Nuclear Information System (INIS)

    Bernal, R.; Perez S, R.; Barboza F, M.; Tostado G, W.C.; Cruz V, C.

    2004-01-01

    In this work, we report the fabrication of new NaCl:Cu phosphors manufactured by following a previously reported sintering method. The samples were made from mixtures of commercially available Na CI and Cu Cl high purity powders. Tl glow curves obtained after exposing the samples to beta radiation exhibit two main intense peaks at 117 and 310 when a 2 C/s heating rate is used. These peaks positions differ from those reported for NaCl:Cu monocrystals. The first peak vanishes in ca. 3 h, while the high temperature one remains with no meaningful changes. The position, as well as the remarkable stability of the high temperature peak indicates that this new phosphors have better properties than the monocrystals present to be applied as detectors and dosimeters of ionizing radiation. (Author)

  2. Morphological study of liver of mice-like rodents from the areas of Altai region exposed to radiation pollution

    International Nuclear Information System (INIS)

    Lushnikova, E.L.; Molodykh, O.P.; Nepomnyashikh, L.M.

    1997-01-01

    Morphofunctional liver state of two mice-like rodents species caught at the three areas of Altai region exposed to radiation during nuclear tests at Semipalatinsk site was studied. It was shown that the stereotype morphofunctional changes in the liver of both rodent species were developed under chronical influence of low doses of radiation and chemical contamination. These changes are manifested as dystrophic disorders of hepatocytes and hemodynamic disturbances accompanied by a decrease of volume ratio of sinusoidal capillaries to hepatocytes and stroma to parenchyma. Hyperglicogenosis, redistribution of the main cytoplasmic organelles, and considerably reduction of the volume densities of mitochondria, smooth and rough endoplasmic reticulum are the leading ultrastructural changes. Moreover, character and manifestation of the changes are determined by ecological belonging and correlated with intensity of anthropogenic pollution. The role of these changes in development of long term pathology are discussed

  3. Medical status of Marshallese accidentally exposed to 1954 Bravo fallout radiation, January 1983-December 1984

    International Nuclear Information System (INIS)

    Adams, W.H.; Engle, J.R.; Harper, J.A.; Heotis, P.M.; Scott, W.A.

    1986-01-01

    March 1, 1984, was the 30th anniversary of the Bravo thermonuclear test that resulted in the accidental exposure of the populations of Rongelap and Utirik atolls to radioactive fallout. The chronicling of the medical events resulting from that exposure is continued in this report, which covers the period from January 1983 through December 1984. An updated listing of all relevant publications from the Medical Department Brookhaven National Laboratory, is presented in the Reference Section. Thirty years of observation continue to show no detectable increase in mortality in the exposed population as a result of that exposure. The survival curves of the high-exposure Rongelap group, the low-exposure Utirik population, and an unexposed group of Rongelap people matched by age and sex to the exposed Rongelap group in 1957 continue to be similar. 89 refs., 2 figs., 6 tabs

  4. Medical status of Marshallese accidentally exposed to 1954 Bravo fallout radiation, January 1983-December 1984

    Energy Technology Data Exchange (ETDEWEB)

    Adams, W.H.; Engle, J.R.; Harper, J.A.; Heotis, P.M.; Scott, W.A.

    1986-01-01

    March 1, 1984, was the 30th anniversary of the Bravo thermonuclear test that resulted in the accidental exposure of the populations of Rongelap and Utirik atolls to radioactive fallout. The chronicling of the medical events resulting from that exposure is continued in this report, which covers the period from January 1983 through December 1984. An updated listing of all relevant publications from the Medical Department Brookhaven National Laboratory, is presented in the Reference Section. Thirty years of observation continue to show no detectable increase in mortality in the exposed population as a result of that exposure. The survival curves of the high-exposure Rongelap group, the low-exposure Utirik population, and an unexposed group of Rongelap people matched by age and sex to the exposed Rongelap group in 1957 continue to be similar. 89 refs., 2 figs., 6 tabs.

  5. Radiation sensitivity of noise in monolithic JFET circuits exposed to 60Co γ - rays

    International Nuclear Information System (INIS)

    Cesura, G.; Re, V.; Tomasini, A.

    1993-01-01

    The spectral density of channel current noise in JFET's is governed in the low-frequency region by Lorentzian terms. Ordinarily, their influence on the equivalent noise charge of preamplifiers for radiation detectors is negligible, as these terms vanish as soon as the frequency exceeds a few Hz. Exposure of JFET's to γ - rays has proved, however, that these noise contributions are enhanced by the absorbed radiation and may invade a much broader frequency range, thereby degrading the equivalent noise charge even at comparatively short processing times. The extent to which the noise behaviour of JFET's is affected by radiation-enhanced Lorentzian terms is analysed in this paper. Results of measurements, carried out after exposure to 60 Co γ - rays of JFET parts and monolithic circuits realised in two different technologies, are discussed and compared with the theoretical predictions. (orig.)

  6. Mortality among workers exposed to external ionizing radiation at a nuclear facility in Ohio

    International Nuclear Information System (INIS)

    Wiggs, L.D.; Cox-DeVore, C.A.; Wilkinson, G.S.; Reyes, M.

    1991-01-01

    In a cohort mortality study of white men employed by the Mound Facility (1947 through 1979), observed deaths did not exceed those expected based on US death rates for the overall cohort or for the subcohort monitored for external ionizing radiation. Among the radiation-monitored subcohort, mortality for workers with cumulative radiation doses of at least 10 mSv was not significantly increased when compared with mortality for coworkers with cumulative doses of less than 10 mSv. A significant dose-response based on a Mantel-Haenszel test of trend was observed for all leukemias. However, when a death from chronic lymphatic leukemia, a type of leukemia generally not regarded as radiogenic, was removed from the analyses, the strength of the dose-response was reduced

  7. Cumulative genetic damage in children exposed to preconception and intrauterine radiation

    International Nuclear Information System (INIS)

    Bross, I.D.; Natarajan, N.

    1980-01-01

    Using a mathematical model and newly developed computer software, the data from the Tri-State Leukemia Survey involving different combinations of radiation exposures to the father and mother prior to conception and to the mother during pregnancy were analyzed. The hypothesis that radiation exposure produces genetic damage which may be expressed in the child both as indicator disease and as leukemia was tested. The genetic damage was estimated in terms of the proportion affected by a given exposure. The relative risk of leukemia and certain other indicator diseases among those affected could then be estimated. The results show that there are at least two distinguishable risk groups, one group with lower (one or two exposures); and the other group with higher (two or three) radiation exposures

  8. Age associated alteration in DNA damage and repair capacity in Turbatrix aceti exposed to ionizing radiation

    International Nuclear Information System (INIS)

    Targovnik, H.S.; Locher, S.E.; Hariharan, P.V.

    1985-01-01

    Excision repair capacity was measured in young and old Turbatrix aceti (phylum Nematoda) following exposure to ionizing radiation. Both repair synthesis and removal of 5,6-dihydroxydihydrothymine type (glycol) base damage were quantitated. At least two-fold higher glycol levels were produced in the DNA of young than of old nematodes for the same radiation dose. Young worms also excised glycol damage more rapidly and completely than old worms. Both peak repair synthesis activity and completion of repair synthesis occurred at earlier times during post-irradiation incubation in young nematodes. The data indicate there is a significant age-associated difference in both the incidence and removal of ionizing radiation damage in T. aceti which is used as a model of the ageing process. (author)

  9. Anomalous effect of small doses of ionizing radiation on metals and alloys

    International Nuclear Information System (INIS)

    Chernov, I.P.; Mamontov, A.P.; Botaki, A.A.; Cherdantsev, P.A.; Chakhlov, B.V.; Sharov, S.R.; Timoshnikov, Yu.A.; Filipenko, L.A.

    1986-01-01

    The effect of small doses of 60 Co gamma rays on copper, tungsten, and WCo alloys has been investigated. A decrease in the concentration of material defects under the influence of small doses of ionizing radiation was found. Also the structural rearrangement of the crystal was found to be still in progress after irradiation ceased. The mechanism of the anomalous effect of small doses of ionizing radiation on metals and alloys is discussed in terms of the electron energy scheme. (U.K.)

  10. Radiation surveillance of exposed workers during activities of moving of the earth area of Montecillo

    International Nuclear Information System (INIS)

    Ortiz, M. T.; Alvarez, A.; Garcia, E.; Diaz, P.; Quinones, J.

    2013-01-01

    One of the objectives of this study was to limit the doses received by exposed workers and the public (in this case the workers of the CIEMATs buildings next to the work) by setting the appropriate criteria of optimization and protection.In addition was a theoretical evaluation of the dose inhalation, workers would have received if ALARA study protection measures has not been established. (Author)

  11. Change in the thermionic work function of semiconductor powders exposed to electromagnetic radiation

    Science.gov (United States)

    Bourasseau, S.; Martin, J. R.; Juillet, F.; Teichner, S. J.

    1977-01-01

    The variations of the thermoelectronic work function of titanium dioxide, submitted to an ultraviolet or visible and infrared radiation, in the presence of oxygen, are studied by the vibrating condenser method. It is shown that during the ultraviolet irradiation, a desorption of a first species of oxygen simultaneously occurs with the adsorption of a second species of oxygen and that this phenomenon is found for any structure of TiO2 (anatase or rutile) any texture, oxygen pressure, radiation intensity, and nature of introduced dopes.

  12. Radiation damage study in CZT matrix detectors exposed to gamma rays

    International Nuclear Information System (INIS)

    Leyva Fabelo, Antonio; Pinnera Hernandez, Ibrahin; Cruz Inclan, Carlos Manuel; Abreu Alfonso, Yamiel; Dona Lemus, Olga; Diaz Garcia, Angelina; Montanno Zetina, Luis Manuel

    2009-01-01

    Radiation damage in terms of atomic displacements in a typical CZT detector used in medical imaging applications was studied using the Monte Carlo statistical method. All detector structural and geometric features as well as different energies of the photons usually used in the application were taken into account. Considering the Mott McKinley Feshbach classical approach, effective cross sections of the displacements were calculated, including the number of displacements per atom for each atomic species present in the material and each photon energy considered. These results are analyzed and compared. Finally, the radiation damage on CZT detector is compared to that calculated in a similar detector manufactured with other semiconducting materials. (author)

  13. Basic trends in the medical observation of staff exposed to ionizing radiations

    International Nuclear Information System (INIS)

    Ingilizova, K.

    1991-01-01

    Some problems of the preliminary and regular medical examinations are discussed as well as the necessity of medical surveillance of the personnel after leaving the sphere of ionizing radiation. The main points which should be included in the preliminary anamnesis are pointed out, as well as the volume of the conventional clinical examinations and special investigations connected with the potential radiation hazards. The necessity of using suitable criteria for evaluation of the occupational fitness for particular cases is stressed. Some considerations are given about the frequency of the regular medical examinations and the type of the test included in them. 3 refs

  14. Basic trends in the medical observation of staff exposed to ionizing radiations

    Energy Technology Data Exchange (ETDEWEB)

    Ingilizova, K [Meditsinska Akademiya, Sofia (Bulgaria). Nauchen Inst. po Rentgenologiya i Radiobiologiya

    1991-01-01

    Some problems of the preliminary and regular medical examinations are discussed as well as the necessity of medical surveillance of the personnel after leaving the sphere of ionizing radiation. The main points which should be included in the preliminary anamnesis are pointed out, as well as the volume of the conventional clinical examinations and special investigations connected with the potential radiation hazards. The necessity of using suitable criteria for evaluation of the occupational fitness for particular cases is stressed. Some considerations are given about the frequency of the regular medical examinations and the type of the test included in them. 3 refs.

  15. Risk of leukemia in susceptible children exposed to preconception, in utero, and postnatal radiation

    International Nuclear Information System (INIS)

    Bross, I.D.J.; Natarajan, N.

    1974-01-01

    Further statistical analysis has clarified the hypothesis that there exists a susceptible subgroup of children who are prone to develop leukemia after exposure to low doses of diagnostic radiation which have no effect on normal insusceptible children. The susceptible group does not show marked increase in relative risk when there is no report of exposure. The risk of developing leukemia among the susceptible children with any of the three types of radiation exposure is markedly increased in the appropriate age groups. The data are concordant with a latent period of 4 to 7 years. (auth)

  16. Perspectives of decision-making and estimation of risk in populations exposed to low levels of ionizing radiations

    Energy Technology Data Exchange (ETDEWEB)

    Fabrikant, J.I.

    1979-01-01

    The setting of any permissible radiation level or guide remains essentially an arbitrary procedure. Based on the radiation risk estimates derived, any lack of precision does not minimize either the need for setting public health policies nor the conclusion that such risks are extremely small when compared with those avialable of alternative options, and those normally accepted by society as the hazards of everyday life. When compared with the benefits that society has established as goals derived from the necessary activities of medical care and energy production, it is apparent that society must establish appropriate standards and seek appropriate controlling procedures which continue to assure that its needs are being met with the lowest possible risks. This implies continuing decision-making processes in which risk-benefit and cost-effectiveness assessments must be taken into account. Much of the practical information necessary for determination of radiation protection standards for public health policy is still lacking. It is now assumed that any exposure to radiaion at low levels of dose carries some risk of deleterious effects. However, how low this level may be, or the probability, or magnitude of the risk, still are not known. Radiation and the public health becomes a societal and political problem and not solely a scientific one. Our best scientific knowledge and our best scientific advice are essential for the protection of the public health, for the effective application of new technologies in medicine, and for guidance in the production of energy in industry. Unless man wishes to dispense with those activities which inevitably involve exposure to low levels of ionizing radiations, he must recognize that some degree of risk, however small, exists. In the evaluation of such risks from radiation, it is necessary to limit the radiation exposure to a level at which the risk is acceptable both to the individual and to society.

  17. Perspectives of decision-making and estimation of risk in populations exposed to low levels of ionizing radiations

    International Nuclear Information System (INIS)

    Fabrikant, J.I.

    1979-01-01

    The setting of any permissible radiation level or guide remains essentially an arbitrary procedure. Based on the radiation risk estimates derived, any lack of precision does not minimize either the need for setting public health policies nor the conclusion that such risks are extremely small when compared with those avialable of alternative options, and those normally accepted by society as the hazards of everyday life. When compared with the benefits that society has established as goals derived from the necessary activities of medical care and energy production, it is apparent that society must establish appropriate standards and seek appropriate controlling procedures which continue to assure that its needs are being met with the lowest possible risks. This implies continuing decision-making processes in which risk-benefit and cost-effectiveness assessments must be taken into account. Much of the practical information necessary for determination of radiation protection standards for public health policy is still lacking. It is now assumed that any exposure to radiaion at low levels of dose carries some risk of deleterious effects. However, how low this level may be, or the probability, or magnitude of the risk, still are not known. Radiation and the public health becomes a societal and political problem and not solely a scientific one. Our best scientific knowledge and our best scientific advice are essential for the protection of the public health, for the effective application of new technologies in medicine, and for guidance in the production of energy in industry. Unless man wishes to dispense with those activities which inevitably involve exposure to low levels of ionizing radiations, he must recognize that some degree of risk, however small, exists. In the evaluation of such risks from radiation, it is necessary to limit the radiation exposure to a level at which the risk is acceptable both to the individual and to society

  18. Pomegranate Alleviates Oxidative Damage and Neurotransmitter Alterations in Rats Brain Exposed to Aluminum Chloride and/or Gamma Radiation

    International Nuclear Information System (INIS)

    Said, U.Z.; EL-Tahawey, N.A.; Elassal, A.A.; Elsayed, E.M.; Shousha, W.Gh.

    2013-01-01

    Aluminum and gamma radiation, both are potent neurotoxins and have been implicated in many human neuro degenerative diseases. The present study was designed to investigate the role of pomegranate in alleviating oxidative damage and alteration of neurotransmitters in the brain of rats exposed to aluminum chloride (AlCl 3 ), and/or gamma radiation (IR). The results revealed that rats whole body exposed to γ- rays, (1 Gy/week up to 4 Gy), and/or administered aluminum chloride (35 mg/kg body weight), via gavages for 4 weeks, resulted in brain tissue damage, featuring by significant increase of the level of thiobarbituric acid reactive substances (TBARS), and advanced oxidation protein products (AOPP), associated with significant decrease of superoxide dismutase (SOD) and catalase (CAT) activities, as well as glutathione (GSH) content indicating occurrence of oxidative stress. A significant decrease of serotonin (5-HT) level associated with a significant increase of 5-hydroxyindole acetic acid (5-HIAA), in addition to a significant decrease in dopamine (DA), norepinephrine (NE) and epinephrine (EPI) contents recorded at the 1st, 7th and 14th day post-irradiation, indicating alterations in the metabolism of brain monoamines. On the other hand, the results exhibited that, supplementation of rats with pomegranate, via gavages, at a dose of 3 ml /kg body weight/ day, for 4 weeks along with AlCl 3 with or without radiation has significantly ameliorated the changes occurred in the mentioned parameters and the values returned close to the normal ones. It could be concluded that pomegranate, by its antioxidant constituents might antagonize brain oxidative damage and minimize the severity of aluminum (Al), and/or radiation-induced neurotransmitters disorders

  19. Dose-dependent hepatic transcriptional responses in Atlantic salmon (Salmo salar) exposed to sublethal doses of gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Song, You, E-mail: you.song@niva.no [Norwegian University of Life Sciences (NMBU), Faculty of Environmental Science and Technology, Department of Environmental Sciences (IMV), Centre for Environmental Radioactivity - CERAD, P.O. Box 5003, N-1432 Ås (Norway); Norwegian Institute for Water Research (NIVA), Gaustadalléen 21, N-0349 Oslo (Norway); Salbu, Brit; Teien, Hans-Christian; Heier, Lene Sørlie [Norwegian University of Life Sciences (NMBU), Faculty of Environmental Science and Technology, Department of Environmental Sciences (IMV), Centre for Environmental Radioactivity - CERAD, P.O. Box 5003, N-1432 Ås (Norway); Rosseland, Bjørn Olav [Norwegian University of Life Sciences (NMBU), Faculty of Environmental Science and Technology, Department of Environmental Sciences (IMV), Centre for Environmental Radioactivity - CERAD, P.O. Box 5003, N-1432 Ås (Norway); Norwegian University of Life Sciences (NMBU), Department of Ecology and Natural Resource Management, P.O. Box 5003, N-1432 Ås (Norway); Tollefsen, Knut Erik [Norwegian University of Life Sciences (NMBU), Faculty of Environmental Science and Technology, Department of Environmental Sciences (IMV), Centre for Environmental Radioactivity - CERAD, P.O. Box 5003, N-1432 Ås (Norway); Norwegian Institute for Water Research (NIVA), Gaustadalléen 21, N-0349 Oslo (Norway)

    2014-11-15

    Highlights: • First study on early stress responses in salmon exposed to low-dose gamma radiation. • Dramatic dose-dependent transcriptional responses characterized. • Multiple modes of action proposed for gamma radiation. - Abstract: Due to the production of free radicals, gamma radiation may pose a hazard to living organisms. The high-dose radiation effects have been extensively studied, whereas the ecotoxicity data on low-dose gamma radiation is still limited. The present study was therefore performed using Atlantic salmon (Salmo salar) to characterize effects of low-dose (15, 70 and 280 mGy) gamma radiation after short-term (48 h) exposure. Global transcriptional changes were studied using a combination of high-density oligonucleotide microarrays and quantitative real-time reverse transcription polymerase chain reaction (qPCR). Differentially expressed genes (DEGs; in this article the phrase gene expression is taken as a synonym of gene transcription, although it is acknowledged that gene expression can also be regulated, e.g., at protein stability and translational level) were determined and linked to their biological meanings predicted using both Gene Ontology (GO) and mammalian ortholog-based functional analyses. The plasma glucose level was also measured as a general stress biomarker at the organism level. Results from the microarray analysis revealed a dose-dependent pattern of global transcriptional responses, with 222, 495 and 909 DEGs regulated by 15, 70 and 280 mGy gamma radiation, respectively. Among these DEGs, only 34 were commonly regulated by all radiation doses, whereas the majority of differences were dose-specific. No GO functions were identified at low or medium doses, but repression of DEGs associated with GO functions such as DNA replication, cell cycle regulation and response to reactive oxygen species (ROS) were observed after 280 mGy gamma exposure. Ortholog-based toxicity pathway analysis further showed that 15 mGy radiation

  20. Metronomic Small Molecule Inhibitor of Bcl-2 (TW-37) Is Antiangiogenic and Potentiates the Antitumor Effect of Ionizing Radiation

    International Nuclear Information System (INIS)

    Zeitlin, Benjamin D.; Spalding, Aaron C.; Campos, Marcia S.; Ashimori, Naoki; Dong Zhihong; Wang Shaomeng; Lawrence, Theodore S.; Noer, Jacques E.

    2010-01-01

    Purpose: To investigate the effect of a metronomic (low-dose, high-frequency) small-molecule inhibitor of Bcl-2 (TW-37) in combination with radiotherapy on microvascular endothelial cells in vitro and in tumor angiogenesis in vivo. Methods and Materials: Primary human dermal microvascular endothelial cells were exposed to ionizing radiation and/or TW-37 and colony formation, as well as capillary sprouting in three-dimensional collagen matrices, was evaluated. Xenografts vascularized with human blood vessels were engineered by cotransplantation of human squamous cell carcinoma cells (OSCC3) and human dermal microvascular endothelial cells seeded in highly porous biodegradable scaffolds into the subcutaneous space of immunodeficient mice. Mice were treated with metronomic TW-37 and/or radiation, and tumor growth was evaluated. Results: Low-dose TW-37 sensitized primary endothelial cells to radiation-induced inhibition of colony formation. Low-dose TW-37 or radiation partially inhibited endothelial cell sprout formation, and in combination, these therapies abrogated new sprouting. Combination of metronomic TW-37 and low-dose radiation inhibited tumor growth and resulted in significant increase in time to failure compared with controls, whereas single agents did not. Notably, histopathologic analysis revealed that tumors treated with TW-37 (with or without radiation) are more differentiated and showed more cohesive invasive fronts, which is consistent with less aggressive phenotype. Conclusions: These results demonstrate that metronomic TW-37 potentiates the antitumor effects of radiotherapy and suggest that patients with head and neck cancer might benefit from the combination of small molecule inhibitor of Bcl-2 and radiation therapy.

  1. Radiation Tolerant, FPGA-based SmallSat Computer System

    Data.gov (United States)

    National Aeronautics and Space Administration — The goal of this project is to mature the technology readiness of a radiation tolerant smallsat computer system for a subsequent orbital flight demonstration. The...

  2. Laser-based flow cytometric analysis of genotoxicity of humans exposed to ionizing radiation during the Chernobyl accident

    International Nuclear Information System (INIS)

    Jensen, R.H.; Bigbee, W.L.; Langlois, R.G.; Grant, S.G.; Pleshanov, P.G.; Chirkov, A.A.; Pilinskaya, M.A.

    1990-01-01

    An analytical technique has been developed that allows laser-based flow cytometric measurement of the frequency of red blood cells that have lost allele-specific expression of a cell surface antigen due to genetic toxicity in bone marrow precursor cells. Previous studies demonstrated a correlation of such effects with the exposure of each individual to mutagenic phenomena, such as ionizing radiation, and the effects can persist for the lifetime of each individual. During the emergency response to the nuclear power plant accident at Chernobyl, Ukraine, USSR, a number of people were exposed to whole body doses of ionizing radiation. Some of these individuals were tested with this laser-based assay and found to express a dose-dependent increase in the frequency of variant red blood cells that appears to be a persistent biological effect. All data indicate that this assay might well be used as a biodosimeter to estimate radiation dose and also as an element to be used for estimating the risk of each individual to develop cancer due to radiation exposure. 17 refs., 5 figs

  3. Activation of eNOS in endothelial cells exposed to ionizing radiation involves components of the DNA damage response pathway

    Energy Technology Data Exchange (ETDEWEB)

    Nagane, Masaki; Yasui, Hironobu; Sakai, Yuri; Yamamori, Tohru [Laboratory of Radiation Biology, Department of Environmental Veterinary Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo 060-0818 (Japan); Niwa, Koichi [Laboratory of Biochemistry, Department of Food and Cosmetic Science, Faculty of Bioindustry, Tokyo University of Agriculture, Abashiri 099-2493 (Japan); Hattori, Yuichi [Department of Molecular and Medical Pharmacology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama 930-0194 (Japan); Kondo, Takashi [Department of Radiological Sciences, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama 930-0194 (Japan); Inanami, Osamu, E-mail: inanami@vetmed.hokudai.ac.jp [Laboratory of Radiation Biology, Department of Environmental Veterinary Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo 060-0818 (Japan)

    2015-01-02

    Highlights: • eNOS activity is increased in BAECs exposed to X-rays. • ATM is involved in this increased eNOS activity. • HSP90 modulates the radiation-induced activation of ATM and eNOS. - Abstract: In this study, the involvement of ataxia telangiectasia mutated (ATM) kinase and heat shock protein 90 (HSP90) in endothelial nitric oxide synthase (eNOS) activation was investigated in X-irradiated bovine aortic endothelial cells. The activity of nitric oxide synthase (NOS) and the phosphorylation of serine 1179 of eNOS (eNOS-Ser1179) were significantly increased in irradiated cells. The radiation-induced increases in NOS activity and eNOS-Ser1179 phosphorylation levels were significantly reduced by treatment with either an ATM inhibitor (Ku-60019) or an HSP90 inhibitor (geldanamycin). Geldanamycin was furthermore found to suppress the radiation-induced phosphorylation of ATM-Ser1181. Our results indicate that the radiation-induced eNOS activation in bovine aortic endothelial cells is regulated by ATM and HSP90.

  4. Radioprotective effect of Tamarindus indica pod extract in Swiss albino mice exposed to whole body electron beam radiation

    International Nuclear Information System (INIS)

    Nandini, S.; Suchetha Kumari, N.; Ganesh Sanjeev; D'sa, Prima

    2013-01-01

    The objective of the study was to investigate the radioprotective effect of Tamarindus indica pod extract against radiation induced damage.The effect of 100 mg of hydroalcoholic extract of Tamarindus indica pod was studied in Swiss albino mice exposed to 6 Gy whole body electron beam radiation. Treatment of mice with extract for 15 days before irradiation reduced the symptoms of radiation sickness when compared with the untreated irradiated group. The irradiated animals showed an elevation in lipid peroxidation and reduction in glutathione, total antioxidants and antioxidant enzymes such as glutathione peroxidase and catalase activities. Radiation induced mice has shown micronucleus in the bone marrow cells. Treatment of mice with Tamarindus indica pod extract before irradiation caused a significant reduction in lipid peroxidation followed by significant elevation in reduced glutathione, total antioxidants, glutathione peroxidase and catalase activity. It also showed a reduction in the micronucleus formation in bone marrow cells. Results indicate that the radioprotective activity of Tamarindus indica pod extract may be due to free radical scavenging attributed as a result of increased antioxidant level in mice. (author)

  5. Depth distributions of DNA damage in Antarctic marine phyto- and bacterioplankton exposed to summertime UV radiation

    NARCIS (Netherlands)

    Buma, A.G.J.; de Boer, M.K.; Boelen, P.

    During a survey from January to March 1998, the occurrence of W-B radiation (UVBR)-induced DNA damage in Antarctic marine phytoplankton and bacterioplankton was investigated, Sampling was done in Ryder Bay, off the British base Rothera Station, 67 degreesS, 68 degreesW (British Antarctic Survey).

  6. Dose-dependent micronuclei formation in normal human fibroblasts exposed to proton radiation

    Czech Academy of Sciences Publication Activity Database

    Litvinchuk, Alexandra; Vachelová, Jana; Michaelidesová, Anna; Wagner, Richard; Davídková, Marie

    2015-01-01

    Roč. 54, č. 3 (2015), s. 327-334 ISSN 0301-634X R&D Projects: GA ČR(CZ) GBP108/12/G108; GA MŠk LM2011019 Institutional support: RVO:61389005 Keywords : human fibroblasts * proton radiation * micronuclei assay * biodosimetry Subject RIV: BO - Biophysics Impact factor: 1.923, year: 2015

  7. Measurement of the optical fiber numeric aperture exposed to thermal and radiation aging

    Science.gov (United States)

    Vanderka, Ales; Bednarek, Lukas; Hajek, Lukas; Latal, Jan; Poboril, Radek; Zavodny, Petr; Vasinek, Vladimir

    2016-12-01

    This paper deals with the aging of optical fibers influenced by temperature and radiation. There are analyzed changes in the structure of the optical fiber, related to the propagation of light in the fiber structure. In this case for numerical aperture. For experimental measurement was used MM fiber OM1 with core diameter 62.5 μm, cladding diameter 125 μm in 2.8 mm secondary coating. Aging of the optical fiber was achieved with dry heat and radiation. For this purpose, we were using a temperature chamber with a stable temperature of 105 °C where the cables after two months. Cables were then irradiated with gamma radiation 60Co in doses of 1.5 kGy and then 60 kGy. These conditions simulated 50 years aging process of optical cables. According to European Standard EN 60793-1-43:2015 was created the automatic device for angular scan working with LabVIEW software interface. Numerical aperture was tested at a wavelength of 850 nm, with an output power 1 mW. Scanning angle was set to 50° with step 0.25°. Numerical aperture was calculated from the position where power has fallen from maximal power at e2 power. The measurement of each sample was performed 10 hours after thermal and radiation aging. The samples were subsequently tested after six months from the last irradiation. In conclusion, the results of the experiment were analyzed and compared.

  8. Frequency of Acentric Fragments Are Associated with Cancer Risk in Subjects Exposed to Ionizing Radiation.

    Czech Academy of Sciences Publication Activity Database

    Fucic, A.; Bonassi, S.; Gundy, S.; Šrám, Radim; Ceppi, M.; Lucas, J.N.

    2016-01-01

    Roč. 36, č. 5 (2016), s. 2451-2457 ISSN 0250-7005 Institutional support: RVO:68378041 Keywords : ionizing radiation * cancer risk * acentric fragments * chromosomal aberrations Subject RIV: DN - Health Impact of the Environment Quality Impact factor: 1.937, year: 2016

  9. DNA damage in cultured human skin fibroblasts exposed to excimer laser radiation

    Energy Technology Data Exchange (ETDEWEB)

    Rimoldi, D.; Miller, A.C.; Freeman, S.E.; Samid, D. (Department of Pathology, Uniformed Services University of the Health Sciences, Bethesda, MD (USA))

    1991-06-01

    Ultraviolet excimer lasers are being considered for use in a variety of refractive and therapeutic procedures, the long-term biologic consequences of which are unknown. The effect of sublethal doses of 193-nm laser radiation on cellular DNA was examined in cultured human skin fibroblasts. In contrast to 248 nm, treatments with the 193-nm laser radiation below 70 J/m2 did not cause significant pyrimidine dimer formation in the skin cells. This was indicated by the lack of excision repair activities (unscheduled DNA synthesis assay), and further demonstrated by direct analysis of pyrimidine dimers in DNA from irradiated cells. However, a low level of unscheduled DNA synthesis could be detected following irradiation at 193 nm with 70 J/m2. Both the 193-nm and 248-nm radiation were able to induce chromosomal aberrations, as indicated by a micronucleus assay. A dose-dependent increase in micronuclei frequency was observed 48 and 72 h after laser irradiation. These results indicate that exposure of actively replicating human skin fibroblasts to sublethal doses of either 193- or 248-nm laser radiation can result in genotoxicity.

  10. Position of cytogenetic examination of cosmonauts for the space radiation expose estimate

    Science.gov (United States)

    Snigireva, Galina; Novitskaya, Natalia; Ivanov, Alexander

    Analysis of chromosome aberrations in human peripheral blood lymphocytes is widely used for the indication and quantitative assessment of radiation. The dose, as estimated by the frequency of chromosome aberrations takes into account not only the physical impact of radiation on the human body but also its individual characteristics, such as radiation sensitivity and functional conditions during irradiation. The purpose of this study was to evaluate the influence of radiation on the chromosome aberration frequency in peripheral blood lymphocytes of the cosmonauts who participated in flights on the ISS (International Space Station). Cytogenetic examination was performed in the period 1992-2013 and included the analysis of chromosome aberrations using conventional Giemsa staining method in blood samples from 38 cosmonauts who participated in flights on the ISS. The cytogenetic examination results showed that cosmic flights lead to an increase of chromosome aberrations in the lymphocytes of cosmonauts. Compared with the pre-flight levels frequencies of dicentrics and centric rings (the radiation exposure markers) are about 4 times higher for cosmonauts after flights. The frequency of chromosome aberrations depends on the length of the flight and, correspondingly, on the accumulated dose of cosmic irradiation. Between flights, a decrease in the chromosome aberration frequency is observed, but even several years after a flight, the level of chromosome aberrations in the lymphocytes of cosmonauts remains high. Cytogenetic monitoring of cosmonauts can undoubtedly play an important role in comprehensive medical surveys of these individuals if we take into account the possible connection of higher levels of chromosomal aberrations with the risk of oncological diseases. Analysis of chromosome aberration dynamics after flights will allow the determination of individuals with an increased cancerogenese risk and provision of required treatments.

  11. Leaf anatomical changes in Populus trichocarpa, Quercus rubra, Pseudotsuga menziesii and Pinus ponderosa exposed to enhanced ultraviolet-B radiation

    International Nuclear Information System (INIS)

    Nagel, L.M.; Bassman, J.H.; Edwards, G.E.; Robberecht, R.; Franceshi, V.R.

    1998-01-01

    Leaf anatomical characteristics are important in determining the degree of injury sustained when plants are exposed to natural and enhanced levels of ultraviolet-B (UV-B) radiation (280–320 nm). The degree to which leaf anatomy can adapt to the increasing levels of UV-B radiation reaching the earth's surface is poorly understood in most tree species. We examined four tree species, representing a wide range of leaf anatomical characteristics, to determine responses of leaf area, specific leaf weight, and leaf tissue parameters after exposure to ambient and enhanced levels of UV-B radiation. Seedlings were grown in a greenhouse with photosynthetically active radiation of 39 mol m −2 day −1 and under one of three daily irradiances of biologically effective UV-B radiation (UV-BBE) supplied for 10 h per day: (1) approximate ambient level received at Pullman, Washington on June 21 (1 x ); two times ambient (2 x ), or three times ambient (3 x ). We hypothesized the response of each species to UV-B radiation would be related to inherent anatomical differences. We found that the conifers responded anatomically to nearly an equal degree as the broad-leaved trees, but that different tissues were involved. Populus trichocarpa, an indeterminate broadleaf species, showed significantly thicker palisade parenchyma in recently mature leaves at the 3 x level and in older leaves under the 2 x level. In addition, individual leaf area was generally greater with increased UV-B irradiance. Quercus rubra, a semi-determinate broadleaf species, exhibited significantly thicker palisade parenchyma at the 2 x and 3 x levels as compared to controls. Psuedotsuga menziesii, an evergreen coniferous species with bifacially flattened needles, and Pinus ponderosa, an evergreen coniferous species with a complete hypodermis, showed no significant change in leaf area or specific leaf weight under enhanced UV-B radiation. Epidermal thickness was unchanged in P. menziesii. However, P. ponderosa

  12. Phenotypic and genotypic characterization of antioxidant enzyme system in human population exposed to radiation from mobile towers.

    Science.gov (United States)

    Gulati, Sachin; Yadav, Anita; Kumar, Neeraj; Priya, Kanu; Aggarwal, Neeraj K; Gupta, Ranjan

    2018-03-01

    In the present era, cellular phones have changed the life style of human beings completely and have become an essential part of their lives. The number of cell phones and cell towers are increasing in spite of their disadvantages. These cell towers transmit radiation continuously without any interruption, so people living within 100s of meters from the tower receive 10,000 to 10,000,000 times stronger signal than required for mobile communication. In the present study, we have examined superoxide dismutase (SOD) enzyme activity, catalase (CAT) enzyme activity, lipid peroxidation assay, and effect of functional polymorphism of SOD and CAT antioxidant genes against mobile tower-induced oxidative stress in human population. From our results, we have found a significantly lower mean value of manganese superoxide dismutase (MnSOD) enzyme activity, catalase (CAT) enzyme activity, and a high value of lipid peroxidation assay in exposed as compared to control subjects. Polymorphisms in antioxidant MnSOD and CAT genes significantly contributed to its phenotype. In the current study, a significant association of genetic polymorphism of antioxidant genes with genetic damage has been observed in human population exposed to radiations emitted from mobile towers.

  13. Influence of Vitamins C and E on Cigarette Smoke Inhalation Injury in Radiation Exposed Guinea Pigs

    International Nuclear Information System (INIS)

    Abu Sinna, G.; El Dighidy, E.; Ashry, O.; Azzoz, G.

    2010-01-01

    Cigarette Smoke is known to cause oxidative stress and is implicated in the initiation of heart disease. This study was conducted to access the potential synergistic effect of successive doses of cigarette smoke inhalation for 21 days and 8 Gy gamma irradiation, fractionated at 4 doses weekly for 2 weeks. Blood antioxidants: superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), reduced glutathione (GSH) and serum malonaldehyde (MDA), lactate dehydrogenase (LDH) were studied in guinea pigs. creatine kinase (CK), total cholesterol (TC), triglycerides (TG) and high and low density cholesterol (HDL and LDL). The potential curative effect of vitamins C and E on the adverse effect of smoke inhalation was also investigated. Administration of vitamins induced a significant drop (P< 0.05) in MDA, CK and LDL. Meanwhile, SOD, GSH and HDL were significantly elevated compared to the control. Animals exposed to cigarette smoke showed significantly elevated LDH and CK enzyme activities as well as MDA conc. Meanwhile, GSH and GSH-px activity were decreased, while no changes were observed in the lipid profile. Vitamins administered to smoke exposed group elevated significantly SOD, GSH-Px, GSH and depressed MDA, LDH, CK and TC compared to the group exposed only to smoke. Irradiation alone or preceded by smoke inhalation induced significant drop in SOD, GSH-Px and GSH as well as elevation in MDA, CK, TG and TC compared to the control. Vitamins intake post-irradiation induced significant elevation in antioxidants and drop in MDA, CK, TG, TC compared to the irradiated group. Vitamins injection to smock irradiated group induced elevation in GSH-Px, GSH and decrease in MDA, CK, TC and LDL compared to irradiated smoke group. The results pointed out the ameliorating effects of vitamins against environment pollutants.

  14. Proteinase activity in cell nuclei of rats exposed to γ-radiation and methyl nitrosourea

    International Nuclear Information System (INIS)

    Malakhova, L.V.; Surkenova, G.N.; Gaziev, A.I.

    1990-01-01

    Activity of nuclear proteinases in blood and liver cells of rats exposed to whole-body γ-irradiation (10 Gy) has been comparatively studied by the capacity of splitting the caseic substrate. Proteinase activity in nuclei of irradiated rat leukocytes was shown to increase by 2.5 times and to gradually decrease after 48 h reaching 150-160% as compared to the control. Two hours following a single injection of methyl nitrosourea the alteration in the activity of proteinases in nuclei of rat hepatocytes and leukocytes was different from the alteration of this index after γ-irradiation

  15. Induced Mitogenic Activity in AML-12 Mouse Hepatocytes Exposed to Low-dose Ultra-Wideband Electromagnetic Radiation

    Directory of Open Access Journals (Sweden)

    P. B. Tchounwou

    2005-04-01

    Full Text Available Ultra–wideband (UWB technology has increased with the use of various civilian and military applications. In the present study, we hypothesized that low-dose UWB electromagnetic radiation (UWBR could elicit a mitogenic effect in AML-12 mouse hepatocytes, in vitro. To test this hypothesis, we exposed AML-12 mouse hepatocytes, to UWBR in a specially constructed gigahertz transverse electromagnetic mode (GTEM cell. Cells were exposed to UWBR for 2 h at a temperature of 23°C, a pulse width of 10 ns, a repetition rate of 1 kHz, and field strength of 5-20 kV/m. UWB pulses were triggered by an external pulse generator for UWBR exposure but were not triggered for the sham exposure. We performed an MTT Assay to assess cell viability for UWBR-treated and sham-exposed hepatocytes. Data from viability studies indicated a time-related increase in hepatocytes at time intervals from 8-24 h post exposure. UWBR exerted a statistically significant (p < 0.05 dose-dependent response in cell viability in both serum-treated and serum free medium (SFM -treated hepatocytes. Western blot analysis of hepatocyte lysates demonstrated that cyclin A protein was induced in hepatocytes, suggesting that increased MTT activity after UWBR exposure was due to cell proliferation. This study indicates that UWBR has a mitogenic effect on AML-12 mouse hepatocytes and implicates a possible role for UWBR in hepatocarcinoma.

  16. The psychological well-being of Norwegian adolescents exposed in utero to radiation from the Chernobyl accident

    Directory of Open Access Journals (Sweden)

    Mednick Sarnoff

    2011-04-01

    Full Text Available Abstract Background On 26 April 1986, the Chernobyl nuclear power plant suffered an accident. Several areas of central Norway were heavily affected by far field radioactive fallout. The present study focuses on the psychological well-being of adolescents who were exposed to this radiation as fetuses. Methods The adolescents (n = 53 and their mothers reported their perceptions of the adolescents' current psychological health as measured by the Youth Self Report and Child Behaviour Checklist. Results In spite of previous reports of subtle cognitive deficits in these exposed adolescents, there were few self-reported problems and fewer problems reported by the mothers. This contrasts with findings of studies of children from the former Soviet Union exposed in utero, in which objective measures are inconsistent, and self-reports, especially by mothers, express concern for adolescents' cognitive functioning and psychological well-being. Conclusion In the current paper, we explore possible explanations for this discrepancy and suggest that protective factors in Norway, in addition to perceived physical and psychological distance from the disaster, made the mothers less vulnerable to Chernobyl-related anxiety, thus preventing a negative effect on the psychological health of both mother and child.

  17. Mössbauer studies of hemoglobin in erythrocytes exposed to neutron radiation

    International Nuclear Information System (INIS)

    Niemiec, Katarzyna; Kaczmarska, Magdalena; Buczkowski, Mateusz; Fornal, Maria; Pohorecki, Władysław; Matlak, Krzysztof; Korecki, Józef; Grodzicki, Tomasz; Burda, Kvetoslava

    2012-01-01

    We studied radiation effects on the stability of various states of hemoglobin (Hb) in red blood cells (RBC) irradiated with a very low dose of neutron rays, 50 μGy. We investigated RBCs isolated from blood of healthy donors. Mössbauer spectroscopy was applied to monitor different forms of Hb. Our results show, for the first time, that oxyhemoglobin (OxyHb) and deoxyhemoglobin (DeoxyHb) are two Hb forms sensitive to such a low neutron radiation. Both Hbs change into a new Hb form (Hb irr ). Additionally, OxyHb transfers into HbOH/H 2 O, which under our experimental conditions is resistant to the action of neutron rays.

  18. ММР and RHOA gene expression in persoms exposed to ionizing radiation

    Directory of Open Access Journals (Sweden)

    Mikhailov V.F.

    2013-12-01

    Full Text Available The purpose of the study is to investigate the mechanisms of MMP-7, -13, TIMP-2 and RhoA genes expression in blood cells after ionizing radiation exposure. Material and methods.\\Ne had examined blood samples from 27 healthy donors, 32 prostate cancer patients before and after radiotherapy, and 32 Chernobyl liquidators by qRT-PCR method. Result. Our results suggests that the expression of MMP-7, MMP-13 genes in prostate cancer patients with grade 2 (T2N0M0. Probably, these changes were associated with the tumor process development, but no with radiation therapy. RhoA level in blood of liquidators was decreased.

  19. Study on the cause of discoloration of radiation-exposed polyolefin

    Energy Technology Data Exchange (ETDEWEB)

    Jeun, Joonpyo; Kang, Philhyun; Oh, Seunghwan; Kim, Hyunbin

    2013-01-15

    Olefinic polymers, such as polyethylene and polypropylene, have a wide variety of known end use applications. Olefinic polymers have been disclosed to be useful in the manufacture of shaped articles for medical used and for food packaging uses where the articles must undergo stabilization for be disinfected. Notwithstanding the significant known advantages of sterilization by means of high energy radiation, several disadvantages are known to be associated with such sterilization techniques. Most of all, when treated with radiation energy in an amount sufficient to achieve the desired sterilization, such polyolefin compositions may become discolored. This coloration may occur for a variety of reasons such as the use of certain additives in the polymer, as well as the presence of high amounts of catalytic residues. In this study, effects of structure of antioxidant and UV stabilizer on the discoloration of olefinic polymer resin were investigated. Furthermore, The mechanism of discoloration of olefinic polymer was suggested.

  20. Study on serum metabonomics of rats exposed to low-dose ionizing radiation, carbon monoxide, benzene and noise

    Directory of Open Access Journals (Sweden)

    Qing-rong WANG

    2015-07-01

    Full Text Available Objective To investigate the combined effects of low-dose ionizing radiation, carbon monoxide, benzene and noise on serum metabolites and the mechanism of injury induced by these complex environmental factors in rats. Methods  Sixteen adult SD rats were randomly divided into control group and exposed group (8 each. The exposed group received the combined effect every day for 7 days. At the end of experiment, sera were collected from the abdominal aorta of rats. The metabolic fingerprint of serum was obtained by 1H nuclear magnetic resonance (1H NMR spectroscopy and determined with pattern recognition techniques of principal component analysis (PCA and orthogonal signal correction-partial least squares (OSC-PLS. The similarities and differences in metabolic profiles between two groups were visualized by SIMCA-P software. Results The rat serum 1H NMR spectra revealed different metabolic spectra between the control group and exposed group. The OSC-PLS plots of the serum samples presented respectively marked clustering between the two groups. Compared with the control group, the contents of lipid, high density lipoprotein, glycine/glucose, N-acetyl glycoprotein 1, N-acetyl glycoprotein 2, phosphatidyl choline and unsaturated fatty acid increased, while those of lactic acid, threonine/lipid, alanine, creatine, glycerylphosphorylcholine/ trimethylamine oxide, low density lipoprotein/high density lipoprotein, low density lipoprotein, very low density lipoprotein/ low density lipoprotein, very low density lipoprotein and saturated fatty acid decreased. Conclusions Combination of low-dose ionizing radiation, carbon monoxide, benzene and noise could induce changes of serum metabolites in rats, involving in immune function, renal function and energy metabolism. The NMR-based-metabonomics method has potential of application in research on combined biological effects of the complex environmental factors. DOI: 10.11855/j.issn.0577-7402.2015.07.09

  1. Variation in the thermionic work function of semiconductor powders exposed to electromagnetic radiation

    Science.gov (United States)

    Bourasseau, S.; Martin, J. R.; Juillet, F.; Teichner, S. J.

    1977-01-01

    The study of the variation of thermoelectronic work function potential of TiO2 in the presence of isobutane shows that this gas is not adsorbed on this solid, in either the presence or the absence of ultraviolet radiation. These results, as well as those obtained in a previous work, lead to the mechanism of the photo-oxidation of isobutane at room temperature, in which excited atomic oxygen is the active species.

  2. Dynamics of organic matter in a Mediterranean mixed forest exposed to chronic gamma radiation

    International Nuclear Information System (INIS)

    Tabone, E.; Poinsot-Balaguer, N.

    1987-01-01

    An area of mixed forest [white oak (Quercus pubescens W.) and evergreen oak (Quercus ilex L.)] in Cadarache (Southern France) has been irradiated for 14 years by a 137 Cs source. Radiation effects on soil organic matter were investigaed at five stations along the gradient towards the source and in a control area of non-irradiatd forest. The highest radiation levels (60-100 mGy x h -1 ) killed trees and shrubs so that there were no ongoing litter inputs to soils in the three nearest stations to the source. Inputs from annuals and radiation tolerant perennials were insignificant in these sites. At lower radiation levels (15 mGy x h -1 ) litter standing crops are increasing. The carbon and nitrogen balance between input and the decomposition of organic matter showed two main patterns. In the areas without litter input the total C and N standing crops were significantly lower than in areas receiving litter, though maintained at a higher level than expected because of the residual organic matter from dead plants. Water trickling down the slope was also a source of N inputs. Principal components analysis showed ordination of the sites according to levels of irradiation and descriminating between C and N concentrations in sites according to litter inputs. On a basis of soil water contents the stations are located on the first axis according to soil organic matter concentrations. Irradiation has a range of direct and indirect effects on soil organic matter but lack of litter input is a key factor. (author)

  3. Genetic monitoring of experimental Drosophila populations exposed to X-radiation and treated with melanin

    International Nuclear Information System (INIS)

    Mosseh, I.B.; Savchenko, V.K.; Lyakh, I.P.

    1985-01-01

    Monitoring of laboratory populations of Drosophila over four years has demonstrated that X radiation of 0.25 C/kg, delivered during the life span of each generation, causes a decrease of 20% and 30%, on the average, in the number of individuals in 1-55 generations and 45-55 generations, respectively. The antimutagen, melanin, added to a nutrient medium has no effect on the number of individuals in populations

  4. Executive order no. 821 on dose monitoring of employees exposed to ionizing radiation

    International Nuclear Information System (INIS)

    1990-01-01

    This Order which entered into force on 1 January 1991, was made in implementation of the European Communities' Council Directive No. 80/836 Euratom amended by Directive No. 84/467 Euratom on radiation protection of 15 July 1980 and 3 September 1984 respectively. It lays down the technical standards to be observed regarding dosimetry and provides inter alia, for dosimetric control by thermoluminescent dosimetry for personal and environmental monitoring. (NEA) [fr

  5. Risk of cancer among children exposed in utero to A-bomb radiations, 1950-84

    International Nuclear Information System (INIS)

    Yoshimoto, Yasuhiko; Kato, Hiroo; Schull, W.J.; Texas Univ., Houston

    1988-01-01

    This study examines the risk of cancer (incidence) over 40 years among in-utero exposed survivors of atomic bombing of Hiroshima and Nagasaki, and adds eight years of follow-up to a previous report confined to mortality. Only two cases of childhood cancer were observed among these survivors in the first 14 years of life; both had been heavily exposed. Subsequent cancers have all been of the adult type. Not only did the observed cancers occur earlier in the 0.30+ Gy dose group than in the 0 Gy dose group but incidence continues to increase, and crude cumulative incidence rate, 40 years after A-bombing, is 3.9-fold greater in the 0.3+ Gy group. In the observation period 1950-84, based on the absorbed dose to the mother's uterus as estimated by the 1986 dosimetry system (DS86), the relative risk of cancer at 1 Gy is 3.77 with a 95% confidence interval of 1.14-13.48. For the entire 0.01 + Gy dose group the average excess risk per 10 4 person-year-gray is 6.57 (0.07-14.49) and the estimated attributable risk is 40.9% (2.9-90.2%). (author)

  6. Development of tumours in dogs exposed to low doses of gamma radiation for a long time

    International Nuclear Information System (INIS)

    Yakovleva, V.I.

    1974-01-01

    150 animals were exposed to chronic (doses 21, 63 and 125 rad/year, with dose rates of 0.06, 0.17 and 0.34 rad/day, respectively) or combined γ-irradiation (chronic irradiation at 63 rad/year and acute irradiation at 58 and 126 rad/year) for a total period of 6 years. Post-mortem examination of 74 irradiated a7 animals revealed malignant neoplasms in 5 (flat-cell pulmonary carcinoma, hepatocellular liver carcinoma, skin basalioma, osteogenic costal sarcoma, and eye melanoma) and bening neoplasms also in 5 (3 leidigomas, parenchymatous thyroid struma and angiofibroma of hypodermic tissue). Of the 19 dogs in the control group, 2 had mammary tumours (cystadenoma and adenofibroma that changed to adenocarcinoma). Most of the neoplasms were seen in animals exposed to chronic irradiation with the highest dose rates as well as in those which received the highest total doses used in chronic irradiation. Acute effects were noted twice as often as chronic ones

  7. Radiation protection - Monitoring of workers occupationally exposed to a risk of internal contamination with radioactive material

    International Nuclear Information System (INIS)

    2006-01-01

    In the course of employment, individuals might work with radioactive materials that, under certain circumstances, could be taken into the body. Protecting workers against risks of incorporated radionuclides requires the monitoring of potential intakes and/or the quantification of actual intakes and exposures. The selection of measures and programmes for this purpose requires decisions concerning methods, techniques, frequencies etc. for measurements and dose assessment. The criteria permitting the evaluation of the necessity of such a monitoring programme or for the selection of methods and frequencies of monitoring usually depend upon the legislation, the purpose of the radiation protection programme, the probabilities of potential radionuclide intakes, and the characteristics of the materials handled. This International Standard offers guidance for the decision whether a monitoring programme is required and how it should be designed. Its intention is to optimise the efforts for such a monitoring programme consistent with legal requirements and with the purpose of the radiation protection programme. Recommendations of international expert bodies and international experience with the practical application of these recommendations in radiation protection programmes have been considered in the development of this International Standard. Its application facilitates the exchanges of information between authorities, supervisory institutions and employers. The International Standard is not a substitute for legal requirements. In the International Standard, the word 'shall' is used to denote a requirement and no deviation is allowed. The word 'should' is used to denote a recommendation from which justified deviations are allowed. The word 'may' is used to denote permission

  8. The protector role of Mn2+ in Saccharomyces cerevisiae exposed to 60Co gamma radiation

    International Nuclear Information System (INIS)

    Galvao, Izabela; Leal, Alexandre Soares; Neves, Maria Jose

    2009-01-01

    The radiation is present on all over the world and can be classified, according to the effect that produces on matter, as non-ionizing and ionizing. The ionizing radiations transfer a sufficient amount of energy to the molecule and charged atoms called ions can be formatted. The biological organisms have approximately 70% of water and when submit to the incident radiation occur the radiolysis of water. Water radiolysis produces highly reactive oxygen species (ROS) known as free radicals. The ROS can interact with all important biomolecules like lipid, protein and DNA. This interaction can cause the loss of functions of theses molecules and thus lead to cell death. The manganese is a heavy metal that at low concentrations is essential for the biological system, since it is cofactor for action of several enzymes. At high concentrations the manganese is toxic to the organisms. Recently was observed that manganese can have a protector role against oxidative stress. In this work, it was studied the anti-oxidant role of manganese in cells submitted to gamma irradiation. It was performed the determination of two oxidative stress indicators: lipid peroxidation and determination of thiol group, the results presented suggest that the manganese had protective role against lipid damage and in this way, has an antioxidant role. (author)

  9. A Combined Tissue Kinetics and Dosimetric Model of Respiratory Tissue Exposed to Radiation. Final Technical Report

    International Nuclear Information System (INIS)

    John R. Ford

    2005-01-01

    Existing dosimetric models of the radiation response of tissues are essentially static. Consideration of changes in the cell populations over time has not been addressed realistically. For a single acute dose this is not a concern, but for modeling chronic exposures or fractionated acute exposures, the natural turnover and progression of cells could have a significant impact on a variety of endpoints. This proposal addresses the shortcomings of current methods by combining current dose-based calculation techniques with information on the cell turnover for a model tissue. The proposed model will examine effects at the single-cell level for an exposure of a section of human bronchiole. The cell model will be combined with Monte Carlo calculations of doses to cells and cell nuclei due to varying dose-rates of different radiation qualities. Predictions from the model of effects on survival, apoptosis rates, and changes in the number of cycling and differentiating cells will be tested experimentally. The availability of dynamic dosimetric models of tissues at the single-cell level will be useful for analysis of low-level radiation exposures and in the development of new radiotherapy protocols

  10. A Combined Tissue Kinetics and Dosimetric Model of Respiratory Tissue Exposed to Radiation

    Energy Technology Data Exchange (ETDEWEB)

    John R. Ford

    2005-11-01

    Existing dosimetric models of the radiation response of tissues are essentially static. Consideration of changes in the cell populations over time has not been addressed realistically. For a single acute dose this is not a concern, but for modeling chronic exposures or fractionated acute exposures, the natural turnover and progression of cells could have a significant impact on a variety of endpoints. This proposal addresses the shortcomings of current methods by combining current dose-based calculation techniques with information on the cell turnover for a model tissue. The proposed model will examine effects at the single-cell level for an exposure of a section of human bronchiole. The cell model will be combined with Monte Carlo calculations of doses to cells and cell nuclei due to varying dose-rates of different radiation qualities. Predictions from the model of effects on survival, apoptosis rates, and changes in the number of cycling and differentiating cells will be tested experimentally. The availability of dynamic dosimetric models of tissues at the single-cell level will be useful for analysis of low-level radiation exposures and in the development of new radiotherapy protocols.

  11. Parameter changes in silicon IMPATT diodes for mm wavelength range exposed to gamma-radiation

    International Nuclear Information System (INIS)

    Shcherbina, L.V.; Torchinskaya, T.V.; Shcherbina, E.S.; Polupan, G.P.

    1999-01-01

    We investigated the p + -n-n + -silicon mesa-diodes fabricated using batch technique whose breakdown voltage was 19±1 V. The exposition of IMPATT diodes to 60 Co gamma-radiation was made in the 10 3 to 10 7 Gy dose range. When the gamma-irradiation dose was increased up to (5-8)*10 5 Gy, then the thermal-generation component of the reverse current was monotonously decreasing. The breakdown voltage remained the same during gamma-irradiation. It was shown experimentally that exposition of diodes to (5-8)*10 5 Gy doses of gamma-irradiation led to some drop of both the number of microplasmas in the avalanche breakdown region and the micro plasma noise level. 60 Co gamma-irradiation in the 10 3 -8*10 5 Gy dose range led also to the growth of the microwave output power P out . The decrease of the micro plasma number in the avalanche breakdown region and Pout growth may be explained if one assumes that gamma-irradiation in the 10 3 - 8*10 5 Gy dose range leads to 'healing' of structural defects in the semiconductor due to their interaction with the radiation-induced point defects. The gamma-irradiation dose increase over 8*10 5 Gy results in a storage of some radiation-induced defects in the IMPATT diode base and electrical parameters of diodes are degrading

  12. 3D quantification of brain microvessels exposed to heavy particle radiation

    International Nuclear Information System (INIS)

    Hintermueller, C; Stampanoni, M; Coats, J S; Obenaus, A; Nelson, G; Krucker, T

    2009-01-01

    Space radiation with high energy particles and cosmic rays presents a significant hazard to spaceflight crews. Recent reviews of the health risk to astronauts from ionizing radiation concluded to establish a level of risk which may indicate the possible performance decrements and decreased latency of late dysfunction syndromes (LDS) of the brain. A hierarchical imaging approach developed at ETH Zuerich and PSI, which relies on synchrotron based X-ray Tomographic Microscopy (SRXTM), was used to visualize and analyze 3D vascular structures down to the capillary level in their precise anatomical context. Various morphological parameters, such as overall vessel volume, vessel thickness and spacing, are extracted to characterize the vascular structure within a region of interest. For a first quantification of the effect of high energy particles on the vasculature we scanned a set of 6 animals, all of same age. The animals were irradiated with 1 Gy, 2 Gy and 4 Gy of 600MeV 56 Fe heavy particles simulating the space radiation environment. We found that with increasing dose the diameter of vessels and the overall vessel volume are decreased whereas the vessel spacing is increased. As these parameters reflect blood flow in three-dimensional space they can be used as indicators for the degree of vascular efficiency which can have an impact on the function and development of lung tissue or tumors.

  13. Radiomodification by Aloe vera leaf extract on skin of Swiss albino mice exposed to gamma radiation

    International Nuclear Information System (INIS)

    Gehlot, Prashasnika; Soyal, Dhanraj; Goyal, P.K.

    2007-01-01

    The development of effective radioprotectors and radiorecovery drugs is of great importance in view of their potential application during both planned (e.g. radiotherapy) and unplanned (e.g. in nuclear industry, natural background radiation emanating from the earth or other sources) radiation exposure. Over the past 50 years, research in the development of radioprotectors has focused on screening a plethora of chemical and biological compounds. Several synthetic chemical compounds have been tested for protection against radiation. But they have limited use due to inherent toxicity. Herbal medicine is still the mainstay of about 75-80 percent of the world population mainly in the developing nations for primary health care because of better cultural acceptability, better compatibility with the human body and lesser side effects. Thus, natural products offer an alternative to their synthetic counterparts due to low toxicity with no side effects. The present investigation has been an attempt to asses the radioprotective efficacy of Aloe vera leaf extract on biochemical alterations in skin of Swiss albino mice

  14. Management and processing of dosimetric data of workers exposed to ionizing radiation

    International Nuclear Information System (INIS)

    Rasoarimalala, T.

    2012-01-01

    The Madagascar - INSTN Radiation protection and Dosimetry Department use the reader HARSHAW TLD 6600 for workers doses reading. Although the performance of this device, manual works is required to store and to maintain the dosimetric data after reading and to note the TLDs sent to the establishments. To avoid these manual works, this present work proposes computer programs written in Python and using SQLite software. One of the programs in python retrieves dose values after reading and transfers directly these doses in the workers database. The use of SQLite software provides a way for the dosimetric data management and the TLDs movement monitoring. The other program assesses estimation of the dose received by worker through a trend curve for workers dosimetric monitoring. The calculated differences of this curve over the curve connecting all points are less than 20%, acceptable limit in radiation protection for TLDs. This present work presents then significances for the personnel occupying individual monitoring of ionizing radiation workers and for these workers too. [fr

  15. Tumour induction by small doses of ionised radiation

    International Nuclear Information System (INIS)

    Putten, L.M. van

    1980-01-01

    The effect of low doses of ionised radiation on tumour induction in animals is discussed. It is hypothesised that high doses of radiation can strongly advance tumour induction from the combination of a stimulated cell growth, as a reaction to massive cell killing, and damage to DNA in the cell nuclei. This effect has a limit below which the radiation dose causes a non-significant amount of dead cells. However in animals where through other reasons, a chronic growth stimulation already exists, only one effect, the damage of DNA, is necessary to induce tumours. A linear dose effect without a threshold level applies in these cases. Applying this hypothesis to man indicates that calculating low dose effects by linear extrapolation of high dose effects is nothing more than a reasonable approximation. (C.F.)

  16. Aggregated Transfer Factors For Small Mammals Collected From the Exposed Sediments Of A 137 Cs Contaminated Reservoir

    Energy Technology Data Exchange (ETDEWEB)

    Paller, Michael H.; Jannika, G. Timothy; Wike, Lynn D

    2005-10-04

    {sup 137}Cs transfer factors were computed for small mammals collected from the dried sediment areas of a partially drained, contaminated reservoir. Soil {sup 137}Cs concentrations were heterogeneous on small and large spatial scales, with a geometric mean of 253.1 Bq/kg dry weight. About 50% of the variance in cotton rat Sigmodon hispidus tissue {sup 137}Cs levels was explained by variation in soil {sup 137}Cs levels. Soil to animal transfer factors (whole body dry weight) averaged 6.0 for cotton rats and 1.2 for cotton mice Peromyscus gossypinus. These values are similar to {sup 137}Cs transfer factors for herbivorous, homeothermic animals from other contaminated ecosystems. Site-specific transfer factors can significantly affect the estimation of dose. In the RESRAD-BIOTA dose model, the default transfer factor for {sup 137}Cs in terrestrial animals is 110 resulting in an estimate of radiation dose to terrestrial biota that is 16 times more than the dose calculated with the actual measured transfer factor.

  17. Frequencies of chromosomal aberrations and sister chromatid exchanges in the benthic worm Neanthes arenaceodentata exposed to ionizing radiation

    International Nuclear Information System (INIS)

    Harrison, F.L.; Rice, D.W. Jr.; Moore, D.H.

    1984-07-01

    Traditional bioassays are unsuitable for assessing sublethal effects from ocean disposal of low-level radioactive waste because mortality and phenotypic responses are not anticipated. We compared the usefulness of chromosomal aberration and sister chromatid exchange (SCE) induction as measures of low-level radiation effects in a sediment-dwelling marine worm, Neanthes arenaceodentata. The SCEs, in contrast to chromosomal aberrations, do not alter the overall chromosome morphology and in mammalian cells appear to be a more sensitive indicator of DNA alterations caused by environmental mutagens. Newly hatched larvae were exposed to two radiation-exposure regimes of either x rays at a high dose rate of 0.7 Gy (70 rad)/min for as long as 5.5 min or to 60 Co gamma rays at a low dose rate of from 4.8 x 10 -5 to 1.2 x 10 -1 Gy (0.0048 to 12 rad)/h for 24 h. After irradiation, the larvae were exposed to 3 x 10 -5 M bromodeoxyuridine (BrdUrd) for 28 h (x-ray-irradiated larvae) or for 54 h ( 60 Co-irradiated larvae). Larval cells were examined for the proportion of cells in first, second, and third or greater division. Frequencies of chromosomal aberrations and SCEs were determined in first and second division cells, respectively. Results from x-ray irradiation indicated that dose-related increases occur in chromosome and chromatid deletions, but a dose of equal or greater 2 Gy (equal to or greater than 200 rad) was required to observe a significant increase. Worm larvae receiving 60 Co irradiation showed elevated SCE frequencies with a significant increase of 0.6 Gy (60 rad). We suggest that both SCEs and chromosomal aberrations may be useful for measuring effects on genetic material induced by radiation. 56 references, 7 figures, 9 tables

  18. Antitumour and Antioxidant Activities of Activin in Kidney Tissue of Mouse Bearing Murine Mammary Adenocarcinoma and Exposed to Gamma Radiation

    International Nuclear Information System (INIS)

    EI-Tahawy, N.A.; Hanafi, N.; Said, U.Z.

    2009-01-01

    Activin (a grape seed-derived proanthocyanidins extract) possess a broad spectrum of biological, pharmacological and therapeutic activities. The present study performed to investigate the preventive and modulating effects of dietary activin in radiation or murine mammary adenocarcinoma (MMA) induced damage in kidneys of albino mice throughout in vitro and in vivo studies. Activin was orally administered to mice for 5 consecutive days (100 mg/ kg body wt) before and 10 days post tumour inoculation. In irradiated group, animals were exposed to 6 Gy whole body gamma-radiations on the fifth day of tumour inoculation. Biochemical and histopathological studies were investigated. In vitro studies using MMA cells revealed that activin increase non viable tumour cell counts. In vivo studies, either MMA or gamma-irradiation resulted in biochemical, and histopathological changes leading to kidney damage. Biochemical studies revealed that activin treatment significantly restored the elevated activity of lactate dehydrogenase (LDH), ameliorated kidney functions profile, and depressed the levels of tumour markers, also enhanced glutathione content (GSH) and activities of superoxide dismutase (SOD) and catalase (CAT). It also reduced kidney lipid peroxides and improves serum total protein level. Histopathological changes in the kidney tissues were attenuated by activin treatment either in MMA-bearing mice group or irradiation group. Exposure of MMA-bearing mouse to gamma- radiations slightly improves the above mentioned damage. While dual treatment of MMA-bearing mice with activin and subsequence with gamma-radiation exposure was more effective. It could be concluded that activin through its antioxidant properties might attenuate radiation or MMA induced renal damage suggesting that activin may have a potential benefit in enhancing radiotherapy

  19. Problems of differential diagnosis in evaluation of pathological effects of ionizing radiation in medical supervision of occupationally exposed persons

    International Nuclear Information System (INIS)

    Stojanovic, D.; Veljkovic, D.; Aleksic, B.; Djukic, Z.

    1977-01-01

    The results of medical supervision of persons occupationally exposed to ionizing radiation and controlled in period to ten years, have been presented. Observations were selected according to occupation (radiologists, phtisiologists, surgeons, physicians, stomatologists, veterinaries, technicians), to the sex, age, character of exposition, film badges data of the received doses. The problems of differential diagnosis of some states and diseases according to the systems (skin, eyes, cardiovascular system, endocrine system, nervous system, haematopoietic tissue), have been discussed with special attention to focus of a disease, which can change numerical values in the peripheral blood or as far as their look is concerned that could be very similar to changes affected by action of ionizing radiation. On the basis of the existed criteria for evaluation of haematological parameters, pathological states of the skin, lenticular injury, changes in cardiovascular system and changes in other systems too, indications and contraindications for work with ionizing radiation have been observed. The incidence and persistance of morphological changes of lymphocytes and granulocytes in peripheral blood and anaemic states in correlation with other changes in the frame of the estimation of risk of malignancy have also been observed. The results obtained showed that the majority of data falls into the normal limits, but nevertheless there were some clinical and laboratory changes caused by the action of radiation, on the basis of which is possible to make the evaluation of the state of the health of radiation workers. An early discovery of changes in some radiosensitive systems, observation of the evolution of changes and influence of factors which favourised the progression of some changes and the problems of specifity and characteristics of some states and diseases, including the importance of differential diagnosis for expertize have been discussed

  20. Heterogeneity in c-jun gene expression in normal and malignant cells exposed to either ionizing radiation or hydrogen peroxide

    International Nuclear Information System (INIS)

    Horio, M.; Collart, F.R.; Huberman, E.

    1993-01-01

    We investigated the role of reactive oxygen intermediates and protein kinase C (PKC) in induction of c-jun gene expression in human ML-2 leukemic cells and normal DET-551 fibroblasts by comparing the effects of either ionizing radiation or H 2 O 2 exposure in the presence or absence of appropriate inhibitors. In these cell types, the radiation and H 2 O 2 -mediated increase in c-jun mRNA levels could be prevented by pretreatment of the cells with N-acetylcysteine, an antioxidant, or H7, an inhibitor of PKC and cAMP-dependent protein kinase (PKA), but not by HA1004, an inhibitor of PKA. These results suggest a role for PKC and reactive oxygen intermediates in the induction of c-jun gene expression in both normal and tumor cells. We also investigated potential differences in radiation- or H 2 O 2 -induced c-jun gene expression in normal and tumor cells by examining steady-state c-jun mRNA levels in a number of human fibroblast, leukemia, melanoma, sarcoma, and carcinoma cell types. We observed heterogeneity in the steady-state level of c-jun mRNA in both the untreated normal and tumor cells and in such cells exposed to ionizing radiation or to H 2 O 2 . Exposure to radiation or to hydrogen peroxide produced a varied response which ranged from little or no induction to a more than two orders of magnitude increase in the steady-state level of the c-jun mRNA

  1. Risk of lower extremity arterial disease in a cohort of workers occupationally exposed to ionizing radiation over a prolonged period

    Energy Technology Data Exchange (ETDEWEB)

    Azizova, Tamara V.; Bannikova, Maria V.; Grigorieva, Evgenia S.; Bagaeva, Yaroslava P.; Azizova, Elena V. [Southern Urals Biophysics Institute, Ozyorsk Chelyabinsk Region (Russian Federation)

    2016-05-15

    In this study the incidence risk of lower extremity arterial disease (LEAD; international classification of diseases version 9 code 440.2) was assessed in a cohort of workers occupationally exposed to radiation over a prolonged period. The study cohort includes 22,377 workers of the Mayak Production Association (25 % of whom are females) first employed at one of the main facilities in 1948-1982 and followed up to the end of 2008. Dose estimates used in the study are provided by Mayak Worker Dosimetry System 2008. The mean total dose from external gamma-rays is 0.54 Gy for males and 0.44 Gy for females. The mean absorbed liver dose from internal alpha-radiation due to incorporated plutonium is 0.23 Gy in males and 0.44 Gy in females. Relative risks and excess relative risks per unit dose (ERR/Gy) are calculated based on maximum likelihood. A total of 943 cases of LEAD are registered in the study cohort during the follow-up of 512,801 person-years. A significant association of LEAD incidence with total dose from external gamma-rays (based on a linear model) was revealed, and the ERR/Gy is 0.27 (95 % confidence interval (CI) 0.11; 0.48). It turned out that a linear-exponential model provides a better fit of the data (∇AIC = 9.957). Inclusion of an adjustment for internal alpha-radiation dose resulted in the reduction of the ERR/Gy to 0.19 (95 % CI 0.05; 0.39), but the risk remains significant. No association of LEAD incidence with dose from internal alpha-radiation was found in the study worker cohort. It is concluded that this study provides evidence for an association of LEAD incidence with dose from external gamma-rays taking non-radiation factors into account. (orig.)

  2. Rapid growth of black holes accompanied with hot or warm outflows exposed to anisotropic super-Eddington radiation

    Science.gov (United States)

    Takeo, Eishun; Inayoshi, Kohei; Ohsuga, Ken; Takahashi, Hiroyuki R.; Mineshige, Shin

    2018-05-01

    We perform two-dimensional radiation hydrodynamical simulations of accretion flows on to a black hole (BH) with a mass of 103 ≤ MBH/ M⊙ ≲ 106 in order to study rapid growth of BHs in the early Universe. For spherically symmetric flows, hyper-Eddington accretion from outside the Bondi radius can occur unimpeded by radiation feedback when MBH ≳ 104 M⊙(n∞/105 cm - 3) - 1(T∞/104 K)3/2, where the density and temperature of ambient gas are initially set to n∞ = 105 cm-3 and T∞ = 104 K. Here, we study accretion flows exposed to anisotropic radiation from a nuclear accretion disc with a luminosity higher than the Eddington value (LEdd) due to collimation towards the bipolar directions. We find that, unlike the spherically symmetric case, even less massive BHs with MBH ionized regions expand towards the poles producing hot outflows with T ˜ 105 K. For more massive BHs with MBH ≳ 5 × 105 M⊙, intense inflows of neutral gas through the equator totally cover the central radiating region due to the non-radial gas motions. Because of efficient recombination by hydrogen, the entire flow settles in neutral and warm gas with T ≃ 8000 K. The BH is fed at a rate of ˜5 × 104LEdd/c2 (a half of the inflow rate from the Bondi radius). Moreover, radiation momentum absorbed by neutral hydrogen produces warm outflows towards the bipolar directions at ˜ 10 per cent of the BH feeding rate and with a velocity several times higher than the escaping value.

  3. Alteration of Organic Compounds in Small Bodies and Cosmic Dusts by Cosmic Rays and Solar Radiation

    Science.gov (United States)

    Kobayashi, Kensei; Kaneko, Takeo; Mita, Hajime; Obayashi, Yumiko; Takahashi, Jun-ichi; Sarker, Palash K.; Kawamoto, Yukinori; Okabe, Takuto; Eto, Midori; Kanda, Kazuhiro

    2012-07-01

    amino acids. Complex amino acid precursors with high molecular weights could be formed in simulated dense cloud environments. They would have been altered in the early solar system by irradiation with soft X-rays from the young Sun, which caused increase of hydrophobicity of the organics of interstellar origin. They were taken up by parent bodies of meteorites or comets, and could have been delivered to the Earth by meteorites, comets and cosmic dusts. Cosmic dusts were so small that they were directly exposed to the solar radiation, which might be critical for the survivability of organics in them. In order to evaluate the roles of space dusts as carriers of bioorganic compounds to the primitive Earth, we are planning the Tanpopo Mission, where collection of cosmic dusts by using ultra low-density aerogel, and exposure of amino acids and their precursors for years are planned by utilizing the Japan Experimental Module / Exposed Facility of the ISS [2]. The mission is now scheduled to start in 2013. We thank Dr. Katsunori Kawasaki of Tokyo Institute of Technology, and Dr. Satoshi Yoshida of National Institute of Radiological Sciences for their help in particles irradiation. We also thank to the members of JAXA Tanpopo Working Group (PI: Prof. Akihiko Yamagishi) for their helpful discussion. [1] K. Kobayashi, et al., in ``Astrobiology: from Simple Molecules to Primitive Life,'' ed. by V. Basiuk, American Scientific Publishers, Valencia, CA, (2010), pp. 175-186. [2] K. Kobayashi, et al., Trans. Jpn. Soc. Aero. Space Sci., in press (2012).

  4. Thermoluminescence of Zn3(PO4)2:Mn2+ exposed to β radiation

    International Nuclear Information System (INIS)

    Perez S, R.; Aceves, R.; Piters D, T.; Rodriguez M, R.; Camarillo, I.; Camarillo, E.

    2015-10-01

    The thermoluminescence (Tl) response and trapping analysis of Zn 3 (PO 4 ) 2 :Mn 2+ glass at room temperature after being exposed to a dose of β-irradiation is reported. The material shows a linear behavior for doses lower than 25 Gy. Measurements indicate that Tl glow curves are composed by several glow peaks. In order to verify this observation, partial heating technique has been applied. The result was the detection of at least four glow peaks located about 124, 199, 240, and 290 degrees C. The complete Tl glow curve shows a higher intensity at temperatures near 200 degrees C, which reduce possibilities of fading. A residual Tl analysis for different waiting times in the measurement of Tl indicate that low decay luminescent centers exist which correspond mainly to the first Tl glow peak. According with the result found, this type of material has potential to be used as β-irradiation dosemeter in different applications. (Author)

  5. Thermomechanical behaviour of a cellular structure exposed to a high radiation flux

    International Nuclear Information System (INIS)

    Biggio, M.; Zani, F.

    1983-01-01

    Cellular structures composed of panels surrounding a number of cooling channels, are envisaged for the first wall in the conceptual design of a TOKAMAK-type experimental fusion reactor. The behaviour of this type of structure when exposed directly to the plasma is analysed. Results show that three-dimensional calculations must be performed in order to assess the real behaviour of the first-wall structure considered. An analysis of an aluminium first-wall model proposed for the experimental reactor INTOR is presented as a specific case. The temperature and stress distributions in the first wall were quantified by two- and three-dimensional calculations using the finite-element method. (author)

  6. Comorbidity and radiation: methodological aspects of health assessment of persons exposed to the Chornobyl accident factors.

    Science.gov (United States)

    Nosach, O V

    2013-01-01

    Comorbidity is one of the most challenging problems of a modern medicine. In a population exposed to the factors of the Chornobyl accident there is an obvious increase in the number of diseases occurring simultaneously against the background of rising prevalence of different classes of chronic medical nosology. The scientific data analysis are presented on the methodological approaches that can be used to create a specialized system for integrated assessment of the health of patients with comorbid disorders. Developing such a system it should be taken into account the trends of changes in the incidence, prevalence and structure of chronic disease, factors and regularities of comorbid disease in the cohorts of Chornobyl accident clean-up workers, evacuees and dwellers of contaminated territories. The system should provide a non-random selection of combinations (clusters) of the most common diseases with serious consequences for the survivors. Nosach O. V., 2013.

  7. Radiation-Induced Chemical Dynamics in Ar Clusters Exposed to Strong X-Ray Pulses

    Science.gov (United States)

    Kumagai, Yoshiaki; Jurek, Zoltan; Xu, Weiqing; Fukuzawa, Hironobu; Motomura, Koji; Iablonskyi, Denys; Nagaya, Kiyonobu; Wada, Shin-ichi; Mondal, Subhendu; Tachibana, Tetsuya; Ito, Yuta; Sakai, Tsukasa; Matsunami, Kenji; Nishiyama, Toshiyuki; Umemoto, Takayuki; Nicolas, Christophe; Miron, Catalin; Togashi, Tadashi; Ogawa, Kanade; Owada, Shigeki; Tono, Kensuke; Yabashi, Makina; Son, Sang-Kil; Ziaja, Beata; Santra, Robin; Ueda, Kiyoshi

    2018-06-01

    We show that electron and ion spectroscopy reveals the details of the oligomer formation in Ar clusters exposed to an x-ray free electron laser (XFEL) pulse, i.e., chemical dynamics triggered by x rays. With guidance from a dedicated molecular dynamics simulation tool, we find that van der Waals bonding, the oligomer formation mechanism, and charge transfer among the cluster constituents significantly affect ionization dynamics induced by an XFEL pulse of moderate fluence. Our results clearly demonstrate that XFEL pulses can be used not only to "damage and destroy" molecular assemblies but also to modify and transform their molecular structure. The accuracy of the predictions obtained makes it possible to apply the cluster spectroscopy, in connection with the respective simulations, for estimation of the XFEL pulse fluence in the fluence regime below single-atom multiple-photon absorption, which is hardly accessible with other diagnostic tools.

  8. Delayed radiation effects at the small and large intestine

    International Nuclear Information System (INIS)

    Wunder, S.

    1982-01-01

    The work deals with 56 patients treated within a period of 15 years for delayed radiation damage to the intestine. Gynecologic carcinomas were most frequently the basic disease. By the time the complaints occurred, which mostly took the form of an ileus, the radiation therapy dated back 4 months to 38 years. The mean age of the patients was 60 years. The report points out the diagnostical problem as well as clinical, radiographic and histological findings. Especially hydronephrosis and renal failure were observed as additional radiation sequelae. Whenever possible, resection of the intestinal segment concerned should be carried through. The portion of radiological patients who attracted the disorder was of 72 per cent, with a lethal result in 37 per cent. Half the patients died from an imperfect anastomosis followed by peritonitis. In 16 per cent of the patients recidivations of the malignant basic disease occurred. Whether treatment of radiation damage of the intestine is successful depends on the care taken to give a diagnosis and on the assessment of the intestinal segment damaged. As the actinic injury tends to aggravate early surgical intervention is recommended. Because the treatment of malignant tumours by irradiation is partly quite successful, injuries to the intestine must to some extent be put up with. (orig./MG) [de

  9. A cytogenetic biomonitoring of industrial radiographers occupationally exposed to low levels of ionizing radiation by using cbmn assay.

    Science.gov (United States)

    Shakeri, Mahsa; Zakeri, Farideh; Changizi, Vahid; Rajabpour, Mohammad Reza; Farshidpour, Mohammad Reza

    2017-06-15

    Industrial radiography is the process of using either gamma-emitting radionuclide sources or X-ray machines to examine the safety of industrial materials. The average annual effective dose in industrial radiography is one of the highest among radiation workers. The aim of this study was to investigate the cytogenetic effects of ionizing radiation in the peripheral blood lymphocytes of 60 industrial radiographers and 40 non-exposed individuals as the control group by using cytokinesis-block micronucleus (CBMN) assay. Totally, the frequencies of micronuclei (MN), nucleoplasmic bridges (NPBs) and nuclear buds (NBUDs) were significantly higher in the industrial radiographers than in the controls (p = 0.000). The mean MN frequency per 1000 binucleated cells in the industrial radiographers with last 5-y radiation dose of >100 mSv was significantly higher than those with ≤100 mSv (34.81 ± 12.7‰ vs. 26.33 ± 7.94‰, p = 0.024). The effect of age was observed in the control group and subjects with the age of >30 y showed significantly higher MN frequency compared with the subjects with the age of ≤30 y (9.45 ± 3.71‰ vs. 6.81 ± 3.05‰, p = 0.02). No obvious trend of increased MN as a function of either duration of employment or age or smoking status was observed in the industrial radiographers. The results show the increased levels of cytogenetic damages in the industrial radiographers. Even the workers exposed to the permissible doses are subjected to elevated frequencies of DNA damages. These findings confirm the importance of cytogenetic biomonitoring program beside physical dosimetry, surveying radiation safety of equipment and periodic training of workers for improvement of safety and radiation protection. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  10. Micronuclei in cytokinesis-blocked lymphocytes of medical personnel occupationally exposed to ionizing radiation

    International Nuclear Information System (INIS)

    Noditi, M.; Draghia, L.; Popescu, D.; Cincu, E.

    2006-01-01

    Bio monitoring of occupational exposures relies on surveillance of exposure and its biological consequences. The measurement of micronuclei in population of exposed cells is a cytogenetic end point used for estimation purposes. To ensure that only dividing cells are scored, cells are treated with cytochalasin B, which blocks cytokinesis and results in bi nucleated cells. Only the bi nucleated cells are evaluated for the formation of micronuclei. In 2004-2005 there have been analyzed and compared two groups of medical staff occupationally exposed to X-rays by using micronucleus test. The first group consisted in 9 doctors and nurses specialized in interventional cardiology from the Institute of Cardiology - Timisoara, Romania, males and females, smokers and nonsmokers. The mean age was 41.5 years and the mean duration of employment 10.6 years. According to personal dosimeters, some of them have had an overdose exposure. The other group consisted in 19 doctors and nurses from the radiology department of several hospitals from Timisoara with the mean age of 48.3 years and the mean duration of employment of 17.8 years. According to personal dosimeters, none of them have had an overdose exposure. The recorded frequency of micronuclei was 62.6/1000 bi nucleated cells for the interventional cardiology personnel. There have been observed cells with 2, 3 and even 5 micronuclei. For the radiology department personnel the frequency of micronuclei was 15.4/1000 bi nucleated cells and the appearance of cells with more than one micronucleus was exceptional. In general, there was a tendency of accumulation of micronuclei with age but the correlation with the age of employment was rather unclear. Due to low doses exposure confounding factors could exist. For instance, a proportion of micronuclei are formed because of other mutagen factors from the environment or smoking habit. Nevertheless the exposure of interventional cardiology personnel is more consistent and further

  11. Micronuclei in cytokinesis-blocked lymphocytes of medical personnel occupationally exposed to ionizing radiation

    Energy Technology Data Exchange (ETDEWEB)

    Noditi, M.; Draghia, L.; Popescu, D. [Institute of Public Health ' Prof. Dr. Leonida Georgescu' Timisoara (Romania); Cincu, E. [University of Agriculture Sciences of Banat, Timisoara (Romania)

    2006-07-01

    Bio monitoring of occupational exposures relies on surveillance of exposure and its biological consequences. The measurement of micronuclei in population of exposed cells is a cytogenetic end point used for estimation purposes. To ensure that only dividing cells are scored, cells are treated with cytochalasin B, which blocks cytokinesis and results in bi nucleated cells. Only the bi nucleated cells are evaluated for the formation of micronuclei. In 2004-2005 there have been analyzed and compared two groups of medical staff occupationally exposed to X-rays by using micronucleus test. The first group consisted in 9 doctors and nurses specialized in interventional cardiology from the Institute of Cardiology - Timisoara, Romania, males and females, smokers and nonsmokers. The mean age was 41.5 years and the mean duration of employment 10.6 years. According to personal dosimeters, some of them have had an overdose exposure. The other group consisted in 19 doctors and nurses from the radiology department of several hospitals from Timisoara with the mean age of 48.3 years and the mean duration of employment of 17.8 years. According to personal dosimeters, none of them have had an overdose exposure. The recorded frequency of micronuclei was 62.6/1000 bi nucleated cells for the interventional cardiology personnel. There have been observed cells with 2, 3 and even 5 micronuclei. For the radiology department personnel the frequency of micronuclei was 15.4/1000 bi nucleated cells and the appearance of cells with more than one micronucleus was exceptional. In general, there was a tendency of accumulation of micronuclei with age but the correlation with the age of employment was rather unclear. Due to low doses exposure confounding factors could exist. For instance, a proportion of micronuclei are formed because of other mutagen factors from the environment or smoking habit. Nevertheless the exposure of interventional cardiology personnel is more consistent and further

  12. Experimental investigation of dynamic pressure in a cryosorbing beam tube exposed to synchrotron radiation

    International Nuclear Information System (INIS)

    Anashin, V.V.; Malyshev, O.B.; Osipov, V.N.; Maslennikov, I.L.; Turner, W.C.

    1994-06-01

    Results of photodesorption experiments on a 4.2-K beam tube irradiated with synchrotron radiation from the VEPP-2M storage ring are being reported. The experiments have been performed on SSC1 and SSC2 beamlines. Synchrotron radiation parameters of the SSC1 beamline are the same as the SSCL 20 TeV proton collider; critical energy = 284 eV, photon intensity 1·10 16 photons/m/s. Photon intensity of the SSC2 beamline is eight times higher than intensity of the SSC1 beamline. We have used two experimental configurations to observe the density increase due to: (1) photodesorption of tightly bound molecules not previously desorbed and (2) photodesorption of weakly bound cryosorbed molecules. The two configurations used were a simple 4.2-K beam tube and a 4.2-K tube with a coaxial perforated liner. The photo-desorption coefficient of tightly bound H 2 measured on the SSC1 beamline was observed to decrease monotonically with photon exposure, reaching η4·10 -4 molecules per photon at the end of exposure (∼1·10 22 photons/m). The same experiment on the SSC2 beamline gave a similar result at photon dose 3.5·10 22 photons/m. The photodesorption coefficient of cryosorbed H 2 increased with increasing H 2 surface density, reaching η'σ w ∼7 molecules/photon at one monolayer surface density (s m ∼3·10 15 H 2 /cm 2 ), where σ w is the sticking coefficient. The liner was shown to effectively shield cryosorbed molecules from synchrotron radiation

  13. Prenatal radiation exposures at diagnostic procedures: methods to identify exposed pregnant patients

    International Nuclear Information System (INIS)

    Pettersson, H.; Sandborg, M.; Nilsson, J.; Olsson, S.

    2002-01-01

    Knowledge about frequency and doses to embryo/foetus from diagnostic radiology is of great importance both in the sense of estimating the radiation risks but also for optimizing the diagnostic procedures and making decisions regarding alternative procedures. In addition, the pregnant patient has the right to know the magnitude and type of radiation risks expected as a result of foetus exposure. From a risk perspective epidemiological data have shown that the embryo/foetus together with children experience higher radiation sensitivity in terms of induced leukemia and cancer compared to an adult population. Recent estimates give cancer excess lifetime mortality risks for whole body exposures of children and foetus (0-15 y age) of 0.06% (ICRP84, 2000) up to 0.14% per 10 mSv (BEIR-V 1990). In addition to the risk of cancer induction effects of cell killing, e.g. CNS abnormalities, cataracts, malformations, growth retardation, may occur. However, these effects are believed to have a threshold, about 100-200 mGy (ICRP84, 2000), and such foetus doses are rarely reached in diagnostic radiology procedures. There are 2 principal situations where foetus exposures may occur in diagnostic radiology; 1. The pregnancy of the patient is known at the time of examination, but due to the medical indications the examination can not be postponed or put forward in time, and there are no suitable alternative non-radiological procedures. 2. The pregnancy of the patient is not known at the time of examination, either due to the fact that the patient is unaware of her pregnancy or the medical personnel failed to obtain this information. The former situation may occur during the first few weeks from conception, whereas the latter situation may cover a greater gestation period

  14. Bonding two surfaces by exposing to actinic radiation an epoxide liquid composition

    International Nuclear Information System (INIS)

    Green, G.E.

    1981-01-01

    A method for preparing a film adhesive from an epoxide resin is described. A liquid containing an epoxide resin and a photopolymerizable compound is polymerized to form a solid continuous film by exposure to actinide radiation. A catalyst can be used but no thermal crosslinking should be allowed to occur. The film so obtained is used to bond surfaces together by the application of heat and pressure. The period of heating can be very short, as there need be no solvent to evaporate and the films need not be thick, typically 20 to 250 μm. (O.T.)

  15. Radiation utilization efficiency and the growth of soybeans exposed to ozone: a comparative analysis

    International Nuclear Information System (INIS)

    Leadley, P.W.; Reynolds, J.F.; Flagler, R.; Heagle, A.S.

    1990-01-01

    Effects of ozone (O 3 ) on field-planted soybeans (Glycine max (L.) Merr. ‘Davis’) were examined using a simple crop-growth model that resolves the rate of increase in crop dry weight into the total amount of radiation intercepted by a crop canopy and the efficiency of conversion of this energy into dry matter (ϵ, termed utilization efficiency). The objectives were : (1) to examine the effects of O 3 on light interception and ϵ, and compare these results with a similar study by Unsworth et al. to determine whether the effects of O 3 are consistent from year to year, and (2) to determine whether ϵ is more sensitive to O 3 during reproductive than vegetative growth and whether allocation of aboveground biomass to seed is affected by O 3 . Five O 3 concentrations (seasonal means of 30, 52, 57, 76 and 99 ppb) were maintained in open-top chambers over the growing season. All treatments were irrigated. Leaf, stem and pod weights and leaf area were measured weekly throughout the season. Total incident solar radiation and total radiation transmission through the canopy were measured with tube solarimeters and electronic integrating devices. Increased O 3 concentrations were accompanied by depressed leaf area expansion and earlier leaf senescence, but did not affect total light interception over the entire season. Utilization efficiency (ϵ) was reduced in high O 3 treatments and was the most important factor in the reduction of yield; ϵ for the whole season declined from 0.89 g MJ −1 in the 30-ppb treatment to a low of 0.68 g MJ −1 in the 99-ppb treatment. Efficiencies were higher during reproductive than vegetative growth, but were not more sensitive to O 3 . Seed yield decreased from 450 g m −2 in the 30-ppb treatment to 320 g m −2 in the 99-ppb treatment. Fractional allocation of aboveground dry weight to seed was not affected by O 3 . Reduced ϵ values with increasing O 3 concentrations were consistent with an earlier study by Unsworth et al. however

  16. Propolis Supplementation and the Changes in the Oxidative Metabolism of Blood Platelets Exposed to Electromagnetic Radiation

    Directory of Open Access Journals (Sweden)

    Henrykowska Gabriela

    2015-03-01

    Full Text Available Introduction. Electromagnetic radiation (EMR that has an effect on living organisms may be a source of oxidative stress. A lack of proper compensation by antioxidant defences on the part of proteins leading to an uncontrolled growth of reactive forms of oxygen, which may give rise to numerous health conditions. Various scientific studies have indicated that propolis has multiple valuable medicinal properties: antibacterial, anti-inflammatory, antioxidant, protective - in relation to liver parenchyma, as well as anti-cancer. Nonetheless, the results of studies concerned with its antioxidant capabilities are not explicit and require further tests and analyses.

  17. Optical effects of exposing intact human lenses to ultraviolet radiation and visible light

    DEFF Research Database (Denmark)

    Kessel, Line; Eskildsen, Lars; Lundeman, Jesper Holm

    2011-01-01

    region of incoming visible light. The aim of the present study was to examine the optical effects on human lenses of short wavelength visible light and ultraviolet radiation. METHODS: Naturally aged human donor lenses were irradiated with UVA (355 nm), violet (400 and 405 nm) and green (532 nm) lasers......: Irradiation with high intensity lasers caused scattering lesions in the human lenses. These effects were more likely to be seen when using pulsed lasers because of the high pulse intensity. Prolonged irradiation with UVA led to photodarkening whereas no detrimental effects were observed after irradiation...

  18. Optical effects of exposing intact human lenses to ultraviolet radiation and visible light

    DEFF Research Database (Denmark)

    Kessel, Line; Eskildsen, Lars Baunsgaard; Lundeman, Jesper Holm

    2011-01-01

    wavelength region of incoming visible light. The aim of the present study was to examine the optical effects on human lenses of short wavelength visible light and ultraviolet radiation. METHODS: Naturally aged human donor lenses were irradiated with UVA (355 nm), violet (400 and 405 nm) and green (532 nm....... RESULTS: Irradiation with high intensity lasers caused scattering lesions in the human lenses. These effects were more likely to be seen when using pulsed lasers because of the high pulse intensity. Prolonged irradiation with UVA led to photodarkening whereas no detrimental effects were observed after...

  19. Mortality in Zarinsk area of Altai Krai as a territory exposed to radiation as a result of nuclear tests at the Semipalatinsk test site

    OpenAIRE

    Kolyado I.; Plugin S.

    2017-01-01

    In Altai krai, there exists a regional segment of the National Radiation Epidemiological Register. The most numerous contingent are victims of nuclear tests at the Semipalatinsk testing site. The new method of calculation of cumulative total effective whole-body radiation dose in patients exposed to radiation as a result of nuclear testing at the Semipalatinsk test site allowed expanding this contingent, to a large extent - due to the inhabitants of Zarinsk area of Altai Krai. The given artic...

  20. Chronic risk assessment for the use of radiation in occupationally exposed personnel (OEP) in the oral health area

    International Nuclear Information System (INIS)

    Flores H, C.; Huerta F, M. R.; Sosa A, M. A.; Diaz de Leon M, L. V.

    2017-10-01

    There is a scientific discordance in the amounts of radiation used in radio-diagnosis and received in practice by the occupationally exposed personnel (OEP), with the exception of radiologists who follow the safety and hygiene measures recommended by the regulations. The objective of this study was to quantify the risk of the OEP in the dental area by the use of ionizing radiation chronically. A fundamental variable to take into account in the study was the number of films taken day/shift. A comparative study was carried out, n = 70 study subjects. The information was collected by occupational clinical history, biological and occupational monitoring. The average age was 19.6 years for E-1 and E-2 was 50 years. The radiation emission in the calibrated equipment was 1.578 (Lp). The risk is 2:1 E-1:E-2. As a result of the study was found that in most cases the OEP does not use protection measures, only the patient. (Author)

  1. Innovative Approaches to Enhance Safety and Radiation Protection on a PET RI/RF Producing Facility for Occupationally Exposed Personnel

    International Nuclear Information System (INIS)

    Avila-Sobarzo, M.J.; Tenreiro, C.; Sadeghi, M.

    2011-01-01

    The explosive demand for positron emission tomography (PET) and, recently introduced, fusion technology (PET/CT and soon commercially available PET/MRI) as non-invasive diagnostic tools of choice for clinical imaging, results on a world wide PET centers and PET RI/RF production facilities remarkably increment . A charged particle accelerator when operated for PET radionuclides production produces ionizing radiation. The multi curies radionuclides from the accelerator and the radiopharmaceuticals synthesized are ionizing radiations emitters open sources. Therefore, the probability of unexpected radiation exposure is always present along full production line, from target loading for irradiation to final dose dispensing.Improving safety working conditions requires permanent radiological risks assessment associated with the production process for accelerator operators, radio chemist and hot cell assistants as well as other occupationally exposed personnel.In this work we present some of the experimental improvements added to our Cyclone 18/9 operation and routinely 18 FDG production process to improve personnel radioprotection. These approaches apply for professionals working on other accelerator field such as non-destructive analytical and tracer technicians at research and industrial levels with charged particle accelerators

  2. The status of the nervous system of persons exposed to occupational chronic radiation (45 years of observation)

    International Nuclear Information System (INIS)

    Azizova, T.V.

    2000-01-01

    The retrospective study of a state of the nervous system in dynamics in 1090 workers of the first Russian atomic enterprise was carried out. The main unfavorable factor of occupational effect in the yearly years of work (1948-1954) was chronic external gamma-radiation in doses from 0.4 to 5.7 Gy per one year. During maximal radiation exposure a vegetative dystonia of a hypotensive type (51.8%), asthenic syndrome (35.2%) and syndrome of microorganic changes of the central nervous system (5.9%) were most frequently registered in workers. Frequency and the periods of the development of these syndromes depended on an annual exposure dose (p<0.001). Alongside with an occupational chronic exposure non-radiation factors (age at the moment of an exposure, initial state of health, intense nature of job regarding nervous loads) exerted the certain influence on the development of these neurologic syndromes. In the long-term period after an exposure the cerebrovascular diseases were most frequent. Their incidence was naturally related with the age of patients. However, it was determined that the initial clinical manifestations of a cerebral atherosclerosis in persons exposed to irradiation in doses more of 2.5 Gy/year were registered in younger age than in control group. The frequency of their development depended on an annual dose of a gamma-irradiation, age at the moment of an exposure, degree of manifestation and duration of preceding vegetative - vascular disorders. (author)

  3. In-Situ Strain Analysis of Potential Habitat Composites Exposed to a Simulated Long-Term Lunar Radiation Exposure

    Science.gov (United States)

    Rojdev, Kristina; O'Rourke, Mary Jane; Hill, Charles; Nutt, Steven; Atwell, William

    2010-01-01

    NASA is studying the effects of long-term space radiation on potential multifunctional composite materials for habitats to better determine their characteristics in the harsh space environment. Two composite materials were selected for the study and were placed in a test stand that simulated the stresses of a pressure vessel wall on the material. The samples in the test stand were exposed to radiation at either a fast dose rate or a slow dose rate, and their strain and temperature was recorded during the exposure. It was found that during a fast dose rate exposure the materials saw a decreased strain with time, or a shrinking of the materials. Given previous radiation studies of polymers, this is believed to be a result of crosslinking occurring in the matrix material. However, with a slow dose rate, the materials saw an increase in strain with time, or a stretching of the materials. This result is consistent with scission or degradation of the matrix occurring, possibly due to oxidative degradation.

  4. FGF2 mediates DNA repair in epidermoid carcinoma cells exposed to ionizing radiation

    International Nuclear Information System (INIS)

    Marie, Melanie; Hafner, Sophie; Moratille, Sandra; Vaigot, Pierre; Rigaud, Odile; Martin, Michele T.; Mine, Solene

    2012-01-01

    Fibroblast growth factor 2 (FGF2) is a well-known survival factor. However, its role in DNA repair is poorly documented. The present study was designed to investigate in epidermoid carcinoma cells the potential role of FGF2 in DNA repair. The side population (SP) with cancer stem cell-like properties and the main population (MP) were isolated from human A431 squamous carcinoma cells. Radiation-induced DNA damage and repair were assessed using the alkaline comet assay. FGF2 expression was quantified by enzyme linked immunosorbent assay (ELISA). SP cells exhibited rapid repair of radiation induced DNA damage and a high constitutive level of nuclear FGF2. Blocking FGF2 signaling abrogated the rapid DNA repair. In contrast, in MP cells, a slower repair of damage was associated with low basal expression of FGF2. Moreover, the addition of exogenous FGF2 accelerated DNA repair in MP cells. When irradiated, SP cells secreted FGF2, whereas MP cells did not. FGF2 was found to mediate DNA repair in epidermoid carcinoma cells. We postulate that carcinoma stem cells would be intrinsically primed to rapidly repair DNA damage by a high constitutive level of nuclear FGF2. In contrast, the main population with a low FGF2 content exhibits a lower repair rate which can be increased by exogenous FGF2. (authors)

  5. Enhancement of heat transfer from a continuously moving porous fin exposed in convective–radiative environment

    International Nuclear Information System (INIS)

    Bhanja, Dipankar; Kundu, Balaram; Aziz, Abdul

    2014-01-01

    Highlights: • Analytical model for thermal analysis of moving porous fins. • Heat transfer from the fin surface due to convection and radiation. • For practical design aspects, optimization analysis was carried out. • Comparative study was made between the solid and porous moving fins. • Porous moving fin has more heat transfer ability than the stationary fin. - Abstract: In the present article, an exercise has been devoted to establish an analytical model for the determination of temperature distribution, fin efficiency and optimum design parameters of a porous moving fin which is losing heat by simultaneous convection and radiation to its surroundings. For the adaptation of this consideration, the governing equation becomes highly nonlinear. An analytical technique called Adomian decomposition method (ADM) is proposed for the solution methodology. The accuracy of the analytic solution is validated by using a numeric scheme called finite difference method. The results indicate that the numerical data and analytical approach are in agreement with each other. As the present study is an analytic, it is extended to the analysis for determination of optimum dimensions of said fin by satisfying either the maximization of rate of heat transfer for a given fin volume or by the minimization of fin volume for a desired heat transfer rate. The study is further extended to the porous fin in stationary condition and it is found that porous fin in moving condition transfers more heat than stationary condition. Investigation has also been made on solid moving fin to compare the outcomes of these parameters

  6. Fluorescence in situ hybridisation in chromosome aberration detection in subjects occupationally exposed to ionising radiation

    International Nuclear Information System (INIS)

    Zeljezic, D.; Garaj-Vrhovac, V.

    2005-01-01

    For more than two decades, chromosomal aberration analysis has been used to detect structural chromosomal aberrations as sensitive biodosimeters of occupational exposure to ionising radiation. Its use is also recommended by the World Health Organisation. Changes in chromosome structure detected by that method are considered to be early biomarkers of a possible malignant disease. Aberrations detected by the method are unstable and can be found in the lymphocytes of irradiated personnel only within a limited time after exposure. To detect stable chromosomal aberrations, which persist after exposure, multicolour fluorescent in situ hybridisation has to be used. Using DNA probes labelled with different fluorochromes, it dyes each pair of chromosomes with different colour. Due to the dynamic of unstable aberration formation, chromosomal aberration analysis is more suitable in genome damage assessment of recent exposures. On the other hand, fluorescence in situ hybridisation gives the information on chromosome instability caused by long-term occupational exposure to ionising radiation. Considering the high costs of fluorescence in situ hybridisation and the uncertainty of the result, it should be used in biodosimetry only when it is absolutely necessary.(author)

  7. Thermoluminescence characterization of CVD diamond film exposed to UV and beta radiation

    International Nuclear Information System (INIS)

    Barboza-Flores, M.; Melendrez, R.; Gastelum, S.; Chernov, V.; Bernal, R.; Cruz-Vazquez, C.; Brown, F.; Pedroza-Montero, M.; Gan, B.; Ahn, J.; Zhang, Q.; Yoon, S.F.

    2003-01-01

    Thermoluminescence (TL) properties of diamond films grown by microwave and hot filament CVD techniques were studied. The main purpose of the present work was to characterize the thermoluminescence response of diamond films to ultraviolet and beta radiation. The thermoluminescence excitation spectrum exhibits maximum TL efficiency around 210-215 nm. All samples presented a glow curve composed of at least one TL peak and showed regions of linear as well as supralinear behavior as a function or irradiation dose. The linear dose dependence was found for up to sixteen minutes of monochromatic UV irradiation and 300 Gy for beta irradiated samples. The activation energy and the frequency factor were determined and found in the range of 0.33-1.7 eV and 5.44 x 10 2 -5.67 x 10 16 s -1 , respectively. The observed TL performance is reasonable appropriate to justify further investigation of diamond films as radiation dosimeters keeping in mind that diamond is an ideal TL dosemeter since it is tissue-equivalent and biological compatible. (copyright 2003 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  8. Onset of behavioral effects in mice exposed to 10 Gy Co-60 radiation

    International Nuclear Information System (INIS)

    Maier, D.M.; Landauer, M.R.

    1990-01-01

    The effects of 10 Gray (Gy) Co-60 radiation on social behavior, locomotor activity, and body weight were assessed in individually housed male Swiss-Webster mice. In experiment 1, aggressive behavior was evaluated prior to irradiation and for 7 d postirradiation by placing an untreated intruder in the irradiated or sham-irradiated resident's home cage for 5 min. Offensive aggressive behavior was not affected significantly by radiation until day 7 postirradiation, when attack latency increased, the frequency and duration of fighting decreased, and the frequency of bites, lunges, and chases decreased. Untreated intruder mice paired with irradiated resident mice showed a decrease in the duration of defensive upright postures and a decrease in the frequency of defensive upright postures, squeaks, and escapes on day 7 postirradiation. In experiment 2, locomotor activity and body weight were monitored for 7 d postirradiation. Body weight was decreased in irradiated mice beginning 4 d postirradiation. Locomotor activity was suppressed in irradiated animals 90 min after irradiation and remained depressed throughout the 7-d testing period. 25 refs

  9. A prospective study of hyperparathyroidism in individuals exposed to radiation in childhood

    International Nuclear Information System (INIS)

    Cohen, J.; Gierlowski, T.C.; Schneider, A.B.

    1990-01-01

    To determine the effects of childhood irradiation on the parathyroid glands, a cohort of 4,297 patients who received radiation to the tonsils before the age of 16 years has been followed-up prospectively. Among the 2,923 patients who were located and provided information, 32 patients developed clinical hyperparathyroidism. The incidence of clinical hyperparathyroidism was 18.7 per 100,000 person-years below the age of 40 years and 171 per 100,000 person-years in the age range of 40 to 60 years. This represents a 2.9-fold and 2.5-fold increase in the incidence of hyperparathyroidism compared with that among the general population. In addition, 31% of the patients who developed hyperparathyroidism also developed thyroid cancer, which is higher than the 11.2% prevalence of thyroid cancer in the patients who received radiation therapy who did not develop parathyroid tumors. Patients with a history of head and neck irradiation should have their parathyroid glands evaluated on a regular basis

  10. The dangers of small doses of radiation: science or science fiction

    International Nuclear Information System (INIS)

    Dunster, H.J.

    1985-01-01

    The paper reviews the risks of small doses of radiation on man. The topic is discussed under the subject headings: the present state of our knowledge; the basis of the present policy: and the scientific standpoint. (U.K.)

  11. Abundance and diversity of aquatic macroinvertebrate communities in lakes exposed to Chernobyl-derived ionising radiation

    International Nuclear Information System (INIS)

    Murphy, J.F.; Nagorskaya, L.L.; Smith, J.T.

    2011-01-01

    Littoral (lake shore) macroinvertebrate communities were studied in eight natural lakes affected by fallout from the Chernobyl accident. The lakes spanned a range in 137 Cs contamination from 100 to 15500 kBq m -2 and estimated external dose rates ranged from 0.13 to 30.7 μGy h -1 . General linear models were used to assess whether abundance of individuals, taxon richness, Berger-Parker dominance and Shannon-Wiener diversity varied across the lakes. Step-wise multiple regressions were used to relate variation in total abundance, taxon richness, Berger-Parker dominance, Shannon-Wiener diversity, taxon richness within major groups of macroinvertebrates and abundance of the more common individual taxa to the measured environmental characteristics (conductivity, pH, total hardness and phosphate; lake area, lake maximum depth and total external dose) of the lakes. No evidence was found in this study that the ecological status of lake communities has been influenced by radioactive contamination from the Chernobyl accident. Indeed, the most contaminated lake, Glubokoye, contained the highest richness of aquatic invertebrates. Taxon richness in the eight study lakes varied from 22 (Svyatskoe no. 7) to 42 (Glubokoye) which spans a range typical for uncontaminated lakes in the region. Since 90 Sr is readily-absorbed by Mollusca, estimated dose rates to this group exceeded those for other invertebrate groups in two lakes (Perstok and Glubokoye). However this study found no association between mollusc diversity or abundance of individual snail species and variation between lakes in the external radiation dose. Indeed Glubokoye, the lake most contaminated by 90 Sr, had the highest richness of freshwater snails per sample (an average of 8.9 taxa per sample). - Highlights: → We studied the effect of radiation on macroinvertebrates in Chernobyl affected lakes. → Abundance, taxon richness, Berger-Parker dominance, Shannon-Wiener diversity evaluated. → No relationship between

  12. Prenatal Radiation exposures at diagnostic procedures: methods to identify exposed pregnant patients

    International Nuclear Information System (INIS)

    Pettersson, H.; Sandborg, M.; Nilsson, J.; Olsson, S.; Hellman, S.; Helmrot, E.; Persliden, J.; Cederlund, T.

    2003-01-01

    Knowledge about frequency and doses to embryo/foetus from diagnostic radiology is of great importance both in the sense of estimating the radiation risks but also for optimizing the diagnostic procedures and making decisions regarding alternative procedures. In addition, the pregnant patient has a right to know the magnitude and type of radiation risks expected as a result of foetus exposure. From a risk perspective epidemiological data has shown that the embryo/foetus together with children experience higher radiation sensitivity in terms of induced leukemia and cancer compared to an adult population. Recent estimates give cancer excess lifetime mortality risks for whole body exposures of children and foetus (0-15 y age) of 0.06% up to 0.14% per 10 mSv. In addition to the risk of cancer induction effects of cell killing, e.g. CNS abnormalities, cataracts, malformations, growth retardation, may occur. However, these effects are believed to have a threshold, about 100-200 mGy, and such foetus doses are rarely reached in diagnostic radiology procedures. There are 2 principal situations where foetus exposures may occur in diagnostic radiology; The pregnancy of the patient is known at the time of examination, but due to the medical indications the examination can not be postponed or put forward in time, and there are no suitable alternative non-radiological procedures. The pregnancy of the patient is not known at the time of examination, either due to the fact that the patient is unaware of her pregnancy or the medical personnel failed to obtain this information. The former situation may occur during the first few weeks from conception, whereas the latter situation may cover a greater gestation period. The frequency of foetus exposure is not well documented. In Sweden, there are well-established routines to track down pregnant patients before examinations are being performed. However, there are no general obligations or routines to document the cases either (i) when

  13. Radiation exposure and dose to small mammals in radon-rich soils

    International Nuclear Information System (INIS)

    Macdonald, C.R.; Laverock, M.J.

    1998-01-01

    Protection of the environment from radionuclide releases requires knowledge of the normal background levels of radiation exposure in the exposed biotic community and an estimate of the detriment caused by additional exposure. This study modeled the background exposure and dose to the lungs of small burrowing mammals from 222 Rn in artificial burrows in radon-rich soils at a site in southeastern Manitoba. E-PERM chambers used to measure 222 Rn in soil showed good reproducibility of measurement, with an average coefficient of variance (CV) of about 10%. Geometric mean (GM) 222 Rn concentrations at nine randomly selected sites ranged from 5,490 Bq/m 3 (GSD = 1.57, n = 7) to 41,000 Bq/m 3 (GSD = 1.02, n = 5). Long-term monitoring of 222 Rn concentrations in artificial burrows showed large variation within and between burrows and did not show consistent variation with season, orientation of the burrow opening, or levels of 226 Ra in the soil. Annual GM concentrations in individual burrows ranged from 7,480 Bq/m 3 (GSD = 1.60) to 18,930 Bq/m 3 (GSD = 1.81) in burrows several meters apart. A grand GM of 9,990 Bq/m 3 (GSD = 1.81, n = 214) was measured over the site for the year. An exposure model was constructed for five small mammal species based on their respiration rates and the number of hours spent in the burrow, active or hibernating, exposed to soil gas 222 Rn, and the time spent out of the burrow exposed to atmospheric 222 Rn. A background dose of 0.9 mGy/a from atmospheric 222 Rn (40 Bq/m 3 ) was estimated for a large-bodied (80 kg), nonburrowing animal living on the soil surface. The highest exposures (mJ/a) in burrowing mammals occurred in those species with the highest respiration rates. Hibernation accounted for a small fraction of total annual exposure ( 22R n concentrations from the field studies and an equilibrium factor (F) of 0.5, doses to lung ranged from 90 mGy/a in the badger to 700 mGy/a in the pocket gopher. These doses closely correspond to those

  14. A small-angle scattering study of bacteriophage T7 using synchrotron radiation

    International Nuclear Information System (INIS)

    Feigin, L.A.; Svergun, D.I.; Dembo, A.T.; Ronto, G.; Toth, K.

    1989-01-01

    Structure transitions in the bacterial virus T7, due to an environment of varying ionic strength, are investigated by means of synchrotron radiation small-angle scattering. Effects of radiation damages and kinetics of the structure transition are separated. Time dependencies of the structural parameters and distribution functions are obtained and characteristic features of the structure rearrangements are described. (orig.)

  15. Ultrastructural alterations in ciliary cells exposed to ionizing radiation. A scanning and transmission electron microscopic study

    Energy Technology Data Exchange (ETDEWEB)

    Baldetorp, L; Mecklenburg, C v; Haakansson, C H [Lund Univ. (Sweden). Hospital; Lund Univ. (Sweden). Dept. of Zoology)

    1977-01-01

    Early effects of ionizing radiation were investigated in an experimental in vitro system using the ciliary cells of the tracheal mucous membrane of the rabbit, irradiated at 30/sup 0/C and at more than 90% humidity. The changes in physiological activities of the ciliary cells caused by irradation were continously registered during the irradation. The specimens were examined immediately after irradiation electron microscopically. The morphological changes in irradiated material after 10-70 Gy are compared with normal material. After 40-70 Gy, scanning electron microscopy revealed the formation of vesicles on cilia, and club-like protrusions and adhesion of their tips. After 30-70 Gy, a swelling of mitochondrial membranes and cristae was apparent transmission electron microscopically. The membrane alterations caused by irradiation are assumed to disturb the permeability and flow of ATP from the mitochondria, which in turn leads to the recorded changes in the activity of the ciliated cells.

  16. Dose-rate effects on mammalian cells exposed to ionizing radiation

    International Nuclear Information System (INIS)

    Mitchell, J.B.

    1978-01-01

    The effect of irradiation on the life cycle and on cell survival was studied for a range of different dose rates. Log phase, plateau phase and synchronized cultures of different mammalian cells were used. Cell cycle redistribution during the radiation exposure was found to be a very important factor in determining the overall dose-rate effect for log phase and synchronized cells. In fact, cell cycle redistribution during the exposure, in some instances, resulted in a lower dose rate being more effective in cell killing per unit dose than a higher dose rate. For plateau phase cultures, where cell cycle times are greatly lengthened, the effects of redistribution in regard to cell killing was virtually eliminated. Both fed and unfed plateau phase cultures exhibited a dose-rate effect, but it was found that below dose rates of 154 rad/h there is no further loss in effectiveness

  17. Specific features of peroxide stress in children permanently exposed to low-intensity radiation

    International Nuclear Information System (INIS)

    Durnov, L.A.; Bajkova, V.N.; Mayakova, S.A.; Polyakov, V.G.; Kolosov, E.A.; Dumbrajs, K.O.; Gracheva, I.V.; Zakharova, N.V.; Leonidova, Yu.A.; Romanova, L.F.

    2000-01-01

    To study the peculiarities of peroxide stress in children residing at the territories with chronic low-intensity radiation effects, the investigation was performed of tyrosine level, indices of the intensity of free radical lipid peroxidation and antioxidant system status in children and teenagers living in Sverdlovsk and Kolpnyansk districts of the Orel region contaminated due to the Chernobyl accident. Regions mentioned are characterized by low-intensity contamination with radionuclides (mainly 90 Sr, 131 I, 137 Cs), 25% an increase in tyrosine content, 1.8 times in malonic dial, 25-40 % in catalase and superoxide dismutase activity was revealed in blood plasma. Contents of A and E vitamins, glutathione and glutathione-depending enzymes are decreased. It is recommended to observe children health in regions contaminated as a result of the Chernobyl accident and correct failed redox processes using antioxidative vitamins [ru

  18. Formation of thymine containing dimers in skin exposed to ultraviolet radiation

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, B E [Dundee Univ. (UK)

    1978-01-01

    Nuclear DNA appears to be the major molecular target for the inhibitory, mutagenic and lethal effects of ultraviolet radiation on cells in culture. Cyclobutyl dimers between adjacent pyrimidine bases, the major photochemical lesions for these effects in prokaryotes, also play a part in UVR effects on eukaryotes cells. Pyrimidine dimers have been isolated from in vivo UV-irradiated guinea pig and mouse skin. The wavelength dependence for dimer induction is similar to that for acute skin reactions but no direct causal relationship has been established. Sunlight UVR may induce dimers in skin DNA. Excision of dimers from mouse skin in vivo is deficient as it is for most rodent cells in culture; human cell excision is efficient and the difficulties in interpretation of UV-carcinogenesis results with mice in terms of human skin cancer are therefore increased.

  19. Thermoluminescence of sulfated zircon exposed to gamma radiation; Termoluminiscencia de circonia sulfatada expuesta a radiacion gamma

    Energy Technology Data Exchange (ETDEWEB)

    Rubio, E.; Castano, V.M. [Centro de Fisica Aplicada y Tecnologia Avanzada, UNAM, A.P. 1-1010, 76000 Queretaro (Mexico); Mendoza A, E.; Gonzalez, P.R. [ININ, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    2003-07-01

    In this work, the thermoluminescent (Tl) signal induced by gamma radiation in zirconia and sulfated zirconia samples embedded in Ptfe pellets is reported and discussed. In this case, samples were obtained through sol-gel method using zirconium n-propoxide and H{sub 2}SO{sub 4} as precursors, and later were subjected to thermal treatment at 600 C to obtain, the tetragonal phase accordingly to X-ray diffraction analysis. Experimental results show that the thermoluminescent glow peak depends on both, the crystalline structure and sulfate concentration. Two maximum peaks were observed located at 147 C and 274 C arising from the electronic transitions. Tl response as a function of the absorbed dose shows a linear increase for a wide of range exposure as well as good stability in time. The high sensitivity, dose linearity and signal stability of this material open the potential possibility to be used for the dosimetry applications. (Author)

  20. Bioassay in BALB/c mice exposed to low dose rate radiation

    Energy Technology Data Exchange (ETDEWEB)

    Km, Sung Dae; Gong, Eun Ji; Bae, Min Ji; Yang, Kwang Mo; Kim, Joong Sun [Dongnam Institute of Radiological and Medical Sciences, Suwon (Korea, Republic of)

    2012-09-15

    The present study was performed to investigate the toxicity of low-dose-rate irradiation in BALB/c mice. Twenty mice of each sex were randomly assigned to four groups of five mice each and were exposed to 0 (sham), 0.02, 0.2, or 2 Gy, equivalents to low-dose-rate irradiation to 3.49 mGy{center_dot}h{sup -1}. Urine, blood, and blood biochemistry were analyzed, and organ weight was measured. The low-dose-rate irradiation did not induce any toxicologically significant changes in mortality, clinical signs, body weight, food and water consumption, urinalysis, and serum biochemistry. However, the weights of reproductive organs including the testis, ovary, and uterus decreased in a dose-dependent manner. Irradiation at 2 Gy significantly decreased the testis, ovary, and uterus weights, but did not change the weights of other organs. There were no adverse effects on hematology in any irradiated group and only the number of neutrophils increased dose dependently. The low-dose-rate irradiation exposure did not cause adverse effects in mice at dose levels of 2 Gy or less, but the reproductive systems of male and female mice showed toxic effects.

  1. Thermally and optically stimulated luminescence of new ZnO nano phosphors exposed to beta radiation

    International Nuclear Information System (INIS)

    Cruz V, C.; Burruel I, S.E.; Grijalva M, H.; Chernov, V.; Bernal, R.

    2006-01-01

    In this work, we report the thermoluminescence (TL) and the optically stimulated luminescence (OSL) of ZnO nano phosphors obtained by thermal annealing of ZnS powders synthesized by precipitation in a chemical bath deposition reaction. To obtain nanocrystalline ZnO, ZnS pellet-shaped samples were subjected to a sintering process at 700 C during 24 under air atmosphere. Some samples were exposed to beta particles in the 0.15-10.15 kGy dose range and the integrated thermoluminescence as a function of dose increased as dose increased, with no saturation clue for the tested doses. Computerized glow-curve deconvolution of the experimental TL curves in individual peaks revealed a second order kinetics. In order to test the BOSL (Blue Optically Stimulated Luminescence) response, samples were beta irradiated with doses up to 600 Gy, showing an increasing OSL intensity as dose increases. From the experimental results that we have obtained, we conclude that the new ZnO phosphors under investigation are good candidates to be used as dosimetric materials. (Author)

  2. Stereotactic body radiation therapy versus conventional radiation therapy in patients with early stage non-small cell lung cancer

    DEFF Research Database (Denmark)

    Jeppesen, Stefan Starup; Schytte, Tine; Jensen, Henrik R

    2013-01-01

    Abstract Introduction. Stereotactic body radiation therapy (SBRT) for early stage non-small cell lung cancer (NSCLC) is now an accepted and patient friendly treatment, but still controversy exists about its comparability to conventional radiation therapy (RT). The purpose of this single...... and SBRT predicted improved prognosis. However, staging procedure, confirmation procedure of recurrence and technical improvements of radiation treatment is likely to influence outcomes. However, SBRT seems to be as efficient as conventional RT and is a more convenient treatment for the patients....

  3. Ag nanoparticle effects on the thermoluminescent properties of monoclinic ZrO2 exposed to ultraviolet and gamma radiation

    International Nuclear Information System (INIS)

    Villa-Sanchez, G; Mendoza-Anaya, D; Gutierrez-Wing, C; Perez-Hernandez, R; Gonzalez-MartInez, P R; Angeles-Chavez, C

    2007-01-01

    The goal of this work was to analyse ZrO 2 in the pure state and when doped with Ag nanoparticles, by electron microscopy, x-ray diffraction and thermoluminescence methods. According to the results obtained, Ag nanoparticles did not modify the morphology or the crystalline structure of the ZrO 2 . The thermoluminescent (TL) response of pure ZrO 2 showed two peaks, one at 334 K and the other at 417 K, when it was exposed to ultraviolet (UV) radiation, and at 342 and 397 K when gamma radiation was used. For ZrO 2 impregnated with Ag nanoparticles a diminished TL intensity due to nanoparticle shielding was observed, but the glow curve shape was similar. However, when Ag nanoparticles were added during the ZrO 2 synthesis, a shift of the TL peaks towards higher temperature values with reference to pure ZrO 2 was observed. A linear dependence of the integrated TL signal as a function of the irradiation dose was observed in all analysed samples. It was possible to determine some kinetic parameters, such as activation energy, kinetic order and frequency factor, using the sequential quadratic programming glow curve deconvolution; it was found that these values are highly dependent on the type of radiation used. Ag nanoparticles present in ZrO 2 also modified the kinetic parameters, mainly when they were added during the synthesis of ZrO 2 . Our results reinforce the possibilities of using pure and doped ZrO 2 as an appropriate dosimetric material in radiation physics

  4. Differential Mobility Spectrometry (DMS) Reveals the Elevation of Urinary Acetylcarnitine in Non-Human Primates (NHPs) Exposed to Radiation.

    Science.gov (United States)

    Vera, Nicholas B; Chen, Zhidan; Pannkuk, Evan; Laiakis, Evagelia C; Fornace, Albert J; Erion, Derek M; Coy, Stephen L; Pfefferkorn, Jeffrey A; Vouros, Paul

    2018-03-29

    Acetylcarnitine has been identified as one of several urinary biomarkers indicative of radiation exposure in adult rhesus macaque monkeys (non-human primates, NHPs). Previous work has demonstrated an up-regulated dose-response profile in a balanced male/female NHP cohort 1 . As a contribution toward the development of metabolomics-based radiation biodosimetry in human populations and other applications of acetylcarnitine screening, we have developed a quantitative, high-throughput method for the analysis of acetylcarnitine. We employed the Sciex SelexIon DMS-MS/MS QTRAP 5500 platform coupled to flow injection analysis (FIA), thereby allowing for fast analysis times of less than 0.5 minutes per injection with no chromatographic separation. Ethyl acetate is used as a DMS modifier to reduce matrix chemical background. We have measured NHP urinary acetylcarnitine from the male cohorts that were exposed to the following radiation levels: control, 2 Gy, 4 Gy, 6 Gy, 7 Gy and 10 Gy. Biological variability, along with calibration accuracy of the FIA-DMS-MS/MS method, indicate LOQ of 20 μM, with observed biological levels on the order of 600 μM and control levels near 10 μM. There is an apparent onset of intensified response in the transition from 6 Gy to 10 Gy. The results demonstrate that FIA-DMS-MS/MS is a rapid, quantitative technique that can be utilized for the analysis of urinary biomarker levels for radiation biodosimetry. This article is protected by copyright. All rights reserved.

  5. Quality assurance of the dose delivered by small radiation segments

    International Nuclear Information System (INIS)

    Hansen, Vebeke N.; Evans, Philip M.; Budgell, Geoffrey J.; Mott, Judith H.L.; Williams, Peter C.; Brugmans, Marco J.P.; Wittkaemper, Frits W.; Mijnheer, Ben J.; Brown, Kevin

    1998-01-01

    The use of intensity modulation with multiple static fields has been suggested by many authors as a way to achieve highly conformal fields in radiotherapy. However, quality assurance of linear accelerators is generally done only for beam segments of 100 MU or higher, and by measuring beam profiles once the beam has stabilized. We propose a set of measurements to check the stability of dose delivery in small segments, and present measured data from three radiotherapy centres. The dose delivered per monitor unit, MU, was measured for various numbers of MU segments. The field flatness and symmetry were measured using either photographic films that are subsequently scanned by a densitometer, or by using a diode array. We performed the set of measurements at the three radiotherapy centres on a set of five different Philips SL accelerators with energies of 6 MV, 8 MV, 10 MV and 18 MV. The dose per monitor unit over the range of 1 to 100 MU was found to be accurate to within ±5% of the nominal dose per monitor unit as defined for the delivery of 100 MU for all the energies. For four out of the five accelerators the dose per monitor unit over the same range was even found to be accurate to within ±2%. The flatness and symmetry were in some cases found to be larger for small segments by a maximum of 9% of the flatness/symmetry for large segments. The result of this study provides the dosimetric evidence that the delivery of small segment doses as top-up fields for beam intensity modulation is feasible. However, it should be stressed that linear accelerators have different characteristics for the delivery of small segments, hence this type of measurement should be performed for each machine before the delivery of small dose segments is approved. In some cases it may be advisable to use a low pulse repetition frequency (PRF) to obtain more accurate dose delivery of small segments. (author)

  6. Induction of cytochrome P450 1 genes and stress response genes in developing zebrafish exposed to ultraviolet radiation

    Energy Technology Data Exchange (ETDEWEB)

    Behrendt, Lars [Biology Department, Redfield 352 MS-32, Woods Hole Oceanographic Institution, 45 Water Street, Woods Hole, MA 02543 (United States); Joensson, Maria E. [Biology Department, Redfield 352 MS-32, Woods Hole Oceanographic Institution, 45 Water Street, Woods Hole, MA 02543 (United States); Department of Environmental Toxicology, Uppsala University (Sweden); Goldstone, Jared V. [Biology Department, Redfield 352 MS-32, Woods Hole Oceanographic Institution, 45 Water Street, Woods Hole, MA 02543 (United States); Stegeman, John J., E-mail: jstegeman@whoi.edu [Biology Department, Redfield 352 MS-32, Woods Hole Oceanographic Institution, 45 Water Street, Woods Hole, MA 02543 (United States)

    2010-06-01

    Ultraviolet (UV) radiation damages cell molecules, and has been suggested to up-regulate mammalian cytochrome P4501 (CYP1) genes through an aryl hydrocarbon receptor (AHR) mediated mechanism. In this study, embryos and larvae of zebrafish (Danio rerio) were exposed to UV to determine the effects on expression of CYP1 and stress response genes in vivo in these fish. Zebrafish embryos were exposed for varying times to UV on two consecutive days, with exposure beginning at 24 and 48 h post-fertilization (hpf). Embryos exposed for 2, 4 or 6 h twice over 2 days to UVB (0.62 W/m{sup 2}; 8.9-26.7 kJ/m{sup 2}) plus UVA (2.05 W/m{sup 2}; 29.5-144.6 kJ/m{sup 2}) had moderately (2.4 {+-} 0.8-fold) but significantly up-regulated levels of CYP1A. UVA alone had no effect on CYP1A expression. Proliferating cellular nuclear antigen (PCNA) and Cu-Zn superoxide dismutase (SOD1) transcript levels were induced (2.1 {+-} 0.2 and 2.3 {+-} 0.5-fold, respectively) in embryos exposed to two 6-h pulses of 0.62 W/m{sup 2} UVB (26.8 kJ/m{sup 2}). CYP1A was induced also in embryos exposed to higher intensity UVB (0.93 W/m{sup 2}) for two 3-h or two 4-h pulses (20.1 or 26.8 kJ/m{sup 2}). CYP1B1, SOD1 and PCNA expression was induced by the two 3-h pulses of the higher intensity UVB, but not after two 4-h pulses of the higher intensity UVB, possibly due to impaired condition of surviving embryos, reflected in a mortality of 34% at that UVB dose. A single 8-h long exposure of zebrafish larvae (8 dpf) to UVB at 0.93 W/m{sup 2} (26.8 kJ/m{sup 2}) significantly induced CYP1A and CYP1B1 expression, but other CYP1 genes (CYP1C1, CYP1C2 and CYP1D1) showed no significant increase. The results show that UVB can induce expression of CYP1 genes as well stress response genes in developing zebrafish, and that UVB intensity and duration influence the responses.

  7. Clinico-morphological comparisons in ultrasound diagnosis of carcinoma of the thyroid in children exposed to radiation

    Energy Technology Data Exchange (ETDEWEB)

    Cherstvoj, E D [Minsk Medical Inst., Minsk (Belarus); Demidchik, E P [Republican Centre of Hygiene and Epidemiology, Minsk (Belarus); Drozd, V M [Scientific Research Inst. for Radiation Medicine, Belarus Ministry of Health, Minsk (Belarus)

    1997-09-01

    The purpose of the study was to compare morphologic and ultrasonic pictures of the thyroid. The study included 42 children with thyroid cancer exposed to ionizing radiation after the Chernobyl accident. All children were operated on during 1990-1994 yy. This study has shown that diffuse sclerosing variant of papillary carcinoma (PC) occurred more frequently in patients with higher absorbed doses to the thyroid. This variant of PC was rarely found at pT1 stage, besides, diffuse sclerosing PC was more frequently accompanied by bilateral and median metastases (``pure`` PC and follicular variant of PC). Biometry of thyroid carcinoma showed a wider spread of neoplastic process in diffuse sclerosing PC than in pure papillary carcinoma. The patients with diffuse sclerosing PC had the second operation more frequently than those with follicular PC. 14 refs, 5 tabs.

  8. Growth, photosynthesis and UV-B absorbing compounds of Portuguese Barbela wheat exposed to ultraviolet-B radiation

    International Nuclear Information System (INIS)

    Correia, C.M.; Torres-Pereira, M.S.; Torres-Pereira, J.M.G.

    1999-01-01

    Wheat plants (Triticum aestivum L.) were exposed to two levels of UV-B radiation (ambient UV-B and high UV-B, simulating a 20% reduction in the ozone layer) under mediterranean field-growth conditions. After 4 months of UV-B treatment, total plant biomass of high UV-B plants was 18% lower compared to control plants. The decrease of biomass appears to be the result of changes in morphological and physiological processes. High UV-B treatment induces decreases in leaf area, net photosynthesis rate, transpiration rate and water use efficiency. Pigment analysis of leaf extracts showed increases in chlorophyll content and no effect on accumulation of UV-B absorbing pigments. The underlying mechanisms for these results are discussed. (author)

  9. Cytogenetic studies in human blood lymphocytes exposed in vitro to radiofrequency radiation at a cellular telephone frequency (835.62 MHz, FDMA).

    Science.gov (United States)

    Vijayalaxmi; Leal, B Z; Meltz, M L; Pickard, W F; Bisht, K S; Roti Roti JL; Straube, W L; Moros, E G

    2001-01-01

    Freshly collected peripheral blood samples from four healthy human volunteers were diluted with RPMI 1640 tissue culture medium and exposed in sterile T-75 tissue culture flasks in vitro for 24 h to 835.62 MHz radiofrequency (RF) radiation, a frequency employed for customer-to-base station transmission of cellular telephone communications. An analog signal was used, and the access technology was frequency division multiple access (FDMA, continuous wave). A nominal net forward power of 68 W was used, and the nominal power density at the center of the exposure flask was 860 W/m(2). The mean specific absorption rate in the exposure flask was 4.4 or 5.0 W/kg. Aliquots of diluted blood that were sham-exposed or exposed in vitro to an acute dose of 1.50 Gy of gamma radiation were used as negative or positive controls. Immediately after the exposures, the lymphocytes were stimulated with a mitogen, phytohemagglutinin, and cultured for 48 or 72 h to determine the extent of genetic damage, as assessed from the frequencies of chromosomal aberrations and micronuclei. The extent of alteration in the kinetics of cell proliferation was determined from the mitotic indices in 48-h cultures and from the incidence of binucleate cells in 72-h cultures. The data indicated no significant differences between RF-radiation- and sham-exposed lymphocytes with respect to mitotic indices, incidence of exchange aberrations, excess fragments, binucleate cells, and micronuclei. In contrast, the response of the lymphocytes exposed to gamma radiation was significantly different from both RF-radiation- and sham-exposed cells for all of these indices. Thus, under the experimental conditions tested, there is no evidence for the induction of chromosomal aberrations and micronuclei in human blood lymphocytes exposed in vitro for 24 h to 835.62 MHz RF radiation at SARs of 4.4 or 5.0 W/kg.

  10. Radiosensitive target in the early mouse embryo exposed to very low doses of ionizing radiation

    International Nuclear Information System (INIS)

    Wiley, Lynn M.; Raabe, Otto G.; Khan, Rakhshi; Straume, Tore

    1994-01-01

    We exposed mouse preimplantation embryos in vitro to either tritiated water (HTO) or tritiated thymidine (TdR) to determine whether the radiosensitive target was nuclear or extranuclear for embryonic cell proliferation disadvantage in the mouse embryo chimera assay. 8-cell embryos were incubated in either HTO or TdR for 2 h and paired with non-irradiated control embryos to form chimeras. Chimeras were cultured for an average of 20.2 h to allow for 2-3 cell cycles and then partially dissociated to obtain the number of progeny cells contributed by the two partner embryos for each chimera. These values were expressed as a 'proliferation ratio' (number of cells from the irradiated embryo: total number of cells in the chimera). A ratio significantly less than 0.50 indicates that the experimental embryo expressed an embryonic cell proliferation disadvantage, which is the endpoint of this assay. The activity concentrations of HTO and TdR were adjusted so that both would deliver comparable mean absorbed nuclear doses during the combined initial 2-h irradiation incubation and subsequent 20.2 h chimera incubation periods. Although nuclear doses were comparable under these conditions, the extranuclear dose delivered by the uniformly distributed HTO was about 100 times greater than the extranuclear dose delivered by TdR for each given nuclear dose. Consequently, obtaining mean TdR proliferation ratios≤mean HTO proliferation ratios would be evidence for a nuclear target while obtaining mean HTO proliferation ratios< mean TdR proliferation ratios would be evidence for an extranuclear target. TdR consistently produced lower mean proliferation ratios over a range of doses from 0.14 Gy to 0.43 Gy. Therefore, we conclude that the radiosensitive target for this endpoint is nuclear

  11. Radiation-Induced Bystander Effects in A549 Cells Exposed to 6 MV X-rays.

    Science.gov (United States)

    Yang, Shuning; Xu, Jing; Shao, Weixian; Geng, Chong; Li, Jia; Guo, Feng; Miao, Hui; Shen, Wenbin; Ye, Tao; Liu, Yazhou; Xu, Haiting; Zhang, Xuguang

    2015-07-01

    The aim of the study is to explore the bystander effects in A549 cells that have been exposed to 6MV X-ray. Control group, irradiated group, irradiated conditioned medium (ICM)-received group, and fresh medium group were designed in this study. A549 cells in the logarithmic growth phase were irradiated with 6MV X-ray at 0, 0.5, 1, 1.5, and 2. In ICM-received group, post-irradiation A549 cells were cultured for 3 h and were transferred into non-irradiated A549 cells for further cultivation. Clone forming test was applied to detect the survival fraction of cells. Annexin V-FITC/PI double-staining assay was used to detect the apoptosis of A549 cells 24, 48, 72, and 96 h after 2-Gy 6MV X-ray irradiation, and the curves of apoptosis were drawn. The changes in the cell cycles 4, 48, 72, and 96 h after 2-Gy 6MV X-ray irradiation were detected using PI staining flow cytometry. With the increase of irradiation dose, the survival fraction of A549 cells after the application of 0.5 Gy irradiation was decreasing continuously. In comparison to the control group, the apoptosis rate of the ICM-received group was increased in a time-dependent pattern, with the highest apoptosis rate observed at 72 h (p X-ray irradiation can induce bystander effect on A549 cells, which reaches a peak at 72 h.

  12. Low Dose Radiation Response Curves, Networks and Pathways in Human Lymphoblastoid Cells Exposed from 1 to 10 cGy of Acute Gamma Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Wyrobek, A. J.; Manohar, C. F.; Nelson, D. O.; Furtado, M. R.; Bhattacharya, M. S.; Marchetti, F.; Coleman, M.A.

    2011-04-18

    We investigated the low dose dependency of the transcriptional response of human cells to characterize the shape and biological functions associated with the dose response curve and to identify common and conserved functions of low dose expressed genes across cells and tissues. Human lymphoblastoid (HL) cells from two unrelated individuals were exposed to graded doses of radiation spanning the range of 1-10 cGy were analyzed by transcriptome profiling, qPCR and bioinformatics, in comparison to sham irradiated samples. A set of {approx}80 genes showed consistent responses in both cell lines; these genes were associated with homeostasis mechanisms (e.g., membrane signaling, molecule transport), subcellular locations (e.g., Golgi, and endoplasmic reticulum), and involved diverse signal transduction pathways. The majority of radiation-modulated genes had plateau-like responses across 1-10 cGy, some with suggestive evidence that transcription was modulated at doses below 1 cGy. MYC, FOS and TP53 were the major network nodes of the low-dose response in HL cells. Comparison our low dose expression findings in HL cells with those of prior studies in mouse brain after whole body exposure, in human keratinocyte cultures, and in endothelial cells cultures, indicates that certain components of the low dose radiation response are broadly conserved across cell types and tissues, independent of proliferation status.

  13. Histomorphologic study of the parotide glands of young rats exposed of ionizing radiation

    International Nuclear Information System (INIS)

    Roslindo, E.B.; Utrilla, L.S.; Roslindo, N.C.; Onofre, M.A.

    1989-01-01

    A study was performed on rats to verify the effects of ionizing radiation on the structure of the parotid glands of young rats. Thirty twenty five-day old rats (Holtzman) were equally distributed into two experimental groups: Group 1 - irradiated; Group II - control. Using a conventional X-ray apparatus, the region of the parotid glands was irradiated with a dose of 300 R, this procedure was repeated every 48 hours up to an exposition of 1200 R. After periods of 3, 8, 13, 18, and 28 days, the animals belonging to both groups were sacrificed and the parotid glands removed and fixed in 10% formalin and Bouin liquid for 24 hours. The sections were stained by hematoxylin and eosin and Mallory's Thricromic, allowing analysis through the usual optical microscope. The following conclusions may be drawn through the methodology used: the Group 1 - rats gained body weight uniformly after the 13 sup(th) day, although this was not equivalent to the control group; the critical phase of glandular disorganization determined by irradiation corresponded to the experimental period of 8 days, decreasing in the subsequent days; the serous acini and the striated ducts showed to be more radium sensitive even under the use of low fractionated doses; the parotid glands showed indications of gradual morphological recovery after the last exposition to X-rays. (author)

  14. Capillary-metric surveillance of the personnel professionally exposed to ionizing radiations

    International Nuclear Information System (INIS)

    Perdereau, B.; Brixy, F.; Cosset, J.M.

    1997-01-01

    The aim of this work was to ensure the surveillance of low irradiation doses cumulated at the level of fingers by means of a sensible, reliable and low-cost method. The skin capillary network represents an indicator of high sensibility for alteration caused by ionizing radiations. The capillary-metry is a method which consists in exploiting numerically the parameters deduced from capillary-scopic observation. A stereo-microscope of low magnifying power and large frontal distance permits a tridimensional visualisation of capillary loops after trans-illumination of the skin (immersion oil). The photographic and numerical recording on diskettes is achieved on the pathological zones of all fingers of both hands. The multi-criteria exploitation (the characteristics of capillaries, their environment and populations) allows their interpretation. Twenty-one subjects were controlled in the frame of a radio-pathological surveillance at Institut Curie de Paris. The case study presenting a confirmed chronic irradiation has evidenced alteration in organisation, in the distribution of capillaries and also a decrease in their number and a diminution of their diameter. Finally, the presence of ecstasies and stenoses is frequent as the presence of desert zones. In conclusion, these alterations, although less spectacularly then the acute irradiation are sufficiently marked to be not confounded with the microvascular chronic anomalies observed in chemists, masons or musicians, as those of current vascular pathology

  15. Antioxidant activity of mulberry (Morus alba L.) fruits in male rats exposed to gamma- radiation

    International Nuclear Information System (INIS)

    Hamza, R.G.; Mekawey, H.M.S.; El shahat, A.N.

    2013-01-01

    This study was designed to investigate the possible ameliorative effects of mulberry fruits on oxidative damage induced by irradiation in male rats. Gamma irradiation (2.5 Gy x 3 delivered every other day) resulted in a significant decrease of hepatic glutathione content (GSH) and the activity of xanthine dehydrogenase (XDH), superoxide dismutase (SOD) and catalase (CAT). The level of insulin and testosterone as well as the concentration of high density lipoprotein-cholesterol (HDL-C) showed a decrease. A remarkable increase of malondialdehyde (MDA) concentration and xanthine oxidase activity was elevated in the liver. The activity of some liver enzymes, the level of glucose and the concentrations of total cholesterol (TC), triglycerides (TG), low density- and very low density lipoprotein-cholesterol showed a significant increase. Administration of mulberry fruit powder (MFP) to irradiated rats was found to offer protection against irradiation induced oxidative stress by elevating the activity of antioxidant enzymes, enhancing liver function in addition to improving the lipid metabolism. From all results collected in this study, it could be concluded that the berries might be considered a natural antioxidant substance that can protect from radiation hazards

  16. Antioxidant enzymes expression in Pseudomonas aeruginosa exposed to UV-C radiation.

    Science.gov (United States)

    Salma, Kloula Ben Ghorbal; Lobna, Maalej; Sana, Khefacha; Kalthoum, Chourabi; Imene, Ouzari; Abdelwaheb, Chatti

    2016-07-01

    It was well known that, UV-C irradiation increase considerably the reactive oxygen species (ROS) levels in eukaryotic and prokaryotic organisms. In the enzymatic ROS-scavenging pathways, superoxide dismutase (SOD), Catalase (CAT), and peroxidase (POX) were developed to deal with oxidative stress. In this study, we investigated the effects of UV-C radiations on antioxidant enzymes (catalase, superoxide dismutase, and peroxidases) expression in Pseudomonas aeruginosa. Catalase, superoxide dismutase, and peroxidases activities were determined spectrophotometrically. Isozymes of superoxide dismutase were revealed by native gel activity staining method. Lipid peroxidation was determined by measuring malondialdehyde formation. Our results showed that superoxide dismutase, catalase and peroxidase activities exhibited a gradual increase during the exposure time (30 min). However, the superoxide dismutase activity was maximized at 15 min. Native gel activity staining assays showed the presence of three superoxide dismutase isozymes. The iron-cofactored isoform activity was altered after exposure to UV-C stress. These finding suggest that catalase and peroxidase enzymes have the same importance toward UV-C rays at shorter and longer exposure times and this may confer additional protection to superoxide dismutase from damage caused by lipid peroxidation. Moreover, our data demonstrate the significant role of the antioxidant system in the resistance of this important human pathogen. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Amplification of the Luminescence Response in Organic Materials Exposed to Ionizing Radiation

    International Nuclear Information System (INIS)

    Michel, M.; Rocha, L.; Hamel, M.; Normand, S.

    2013-06-01

    Polymer-based scintillators present interesting features for the field of ionizing radiation detection, related to the high sensitivity of fluorescence techniques coupled to the manufacturing advantages of such materials. Organic materials can indeed be manufactured into large sensing areas with different geometrical conformations through low-cost fabrication techniques. While results herein presented focus on liquids, the same phenomena would occur in solid samples. Widely used for sensing applications because of its high sensitivity, fluorescence has yet been further improved using technologies yielded by research in photonics. It has already been shown that the use of nano-structuring for sensing applications enables previously unattained sensitivities. Herein we propose a technique based on the manipulation of light using nano-structuring of the detection medium in order to enable the amplification of the sensitive material emission. This amplification of the luminescence signal is aimed at reducing the detection limit of low-energy beta emitters such as tritium, well-known issue of major importance. The first step of our study, presented here, consists in demonstrating the ability of well-known scintillators to emit in laser regime when optically excited in a Distributed Feedback scheme. They are, to our knowledge, the first of their kind. The technique here presented, being usable whatever the sample maximum emission wavelength, should also enable a simplification of the devices based on scintillators. (authors)

  18. Supervision of professional personnel exposed to ionizing radiation (X-rays)

    International Nuclear Information System (INIS)

    Chalabreysse, J.

    1964-10-01

    After a short introduction giving the physical characteristics and the possible interactions of X-rays, this report considers in more detail the basis of the dosimetry and the units used. Taking into account the dangers of irradiation and the professional norms applicable, the report reviews the physical methods (collective and individual dosimetry) and the biological method (based on the systematic supervision of the hemogram) which are used to ensure that these professional norms an respected. As an example the influence is studied of repeated doses of X-rays on the hemogram of X-ray operators when the individual radiation levels are known through dosimetric films. Two processes are used: one considers the mean values (irradiation and average hemogram for each person), the other requires the use of an electronic computer and uses each haematological variable as a function of the monthly or cumulative doses; it gives correlation coefficients for the different variables. In conclusion, the results obtained are compared to those conventionally accepted, and the validity of the hemogram is estimated as a criterion for the supervision. (author) [fr

  19. Adaptive repair induced by small doses of γ radiation in repair-defective human cells

    International Nuclear Information System (INIS)

    Zasukhina, G.D.; L'vova, G.N.; Vasil'eva, I.M.; Sinel'shchikova, T.A.; Semyachkina, A.N.

    1993-01-01

    Adaptive repair induced by small doses of gamma radiation was studied in repair-defective xeroderma pigmentosum, gout, and homocystinuria cells. The adaptation of cells induced by small doses of radiation was estimated after subsequent exposure to gamma radiation, 4-nitroquinoline-1-oxide, and N-methyl-N-nitro-N-nitrosoguanidine by three methods: (1) by the reduction in DNA breaks; (2) by induction of resistant DNA synthesis; and (3) by increased reactivation of vaccinia virus. The three cell types in response to the three different mutagens revealed differences in the mechanism of cell defense in excision repair, in the adaptive response, and in Weigl reactivation

  20. Central nervous system radiation injury in small animal models

    International Nuclear Information System (INIS)

    Kogel, A.J. van der

    1991-01-01

    Experimental studies on radiation injury in the central nervous system have been carried out in many species ranging from mouse to monkey. This review is restricted to studies in rodents irradiated with low linear energy transfer (LET) radiation. In this paper, the various rodent models of brain and spinal cord injury are described with particular emphasis on the pathology of different types of lesions and theories of their pathogenesis. Many of the initial studies were limited to relatively high single doses, but in later work more clinically relevant fractionated irradiation schemes were employed. This has led to the recognition of various types of early and late delayed injury that are analogous to the syndromes observed in humans. Two main pathways have been suggested for the pathogenesis, one involving predominantly the progressive loss of glial cells and the other involving vascular injury. The relative importance of both mechanisms will be discussed with respect to treatment conditions and to dose level in particular. An hypothesis is presented concerning the possible role of different cell types in the development of specific syndromes

  1. Apoptosis and mitosis in the small intestine at radiation injury

    International Nuclear Information System (INIS)

    Hashiguchi, Junichiro; Ito, Masahiro; Onizuka, Shinya; Sekine, Ichiro; Uchida, Shinji

    1990-01-01

    A single whole body irradiation was given at a dose rate of 0.298 Gy/min in 6-week-old male mice. Intestinal crypt apoptosis and mitosis cells were determined by delivering radiation doses of 0.4, 0.6, 1.0, 1.5, 2.0, 5.0, 10.0, and 20.0 Gy. The incidence of apoptosis was linearly increased in a dose-dependent manner up to 5.0 Gy, and thereafter, it was gradually decreased. There was a decreased tendency for mitosis with delivering higher radiation doses. The incidence of apoptosis rapidly increased 2 hours after irradiation with either 0.6 Gy or 2.0 Gy, and reached to the peak 4 hours later. It brought about a 18-fold and 28-fold increase for 0.6 Gy and 2.0 Gy, respectively, relative to that before irradiation. Mitosis cells decreased by half one hour after irradiation with 0.6 Gy, and then returned to the pre-irradiation value through synchronization 24 hours later. The number of cells positive to BrdU was 776 in the group of mice without irradiation and 479 in the group of mice irradiated with 2.0 Gy. (N.K.)

  2. New limits to the small scale fluctuations in the cosmic background radiation

    International Nuclear Information System (INIS)

    Kellermann, K.I.; Fomalont, E.B.; Wall, J.V.

    1983-01-01

    The VLA has been used at 4.9 GHz to observe a small region of sky in order to extend the radio source count to low flux density (Fomalont et al., these proceedings) and to look for small scale fluctuations in the 2.7 K cosmic microwave background radiation. (Auth.)

  3. Radiation planning in small complex lesions and experimental verification

    International Nuclear Information System (INIS)

    Jess-Hempen, A.; Wowra, B.; Mack, A.; Kreiner, H.J.; Heck, B.

    2003-01-01

    The Gamma Knife is used as a sterotactic tool for the conformal treatment of very small, complex-shape cranial lesions. The combination of planning software and treatment equipment enables a highly-precise conformal dose distribution and positioning. The purpose of the present study was to experimentally verify the precision actually achievable in case of extremely irregular, small target volumes. For this purpose, a complete treatment procedure was performed using a standard head phantom complemented with a specially developed insert that simulates an L-shaped lesion. The spatial precision of the irradiation was recorded by means of high-resolution film dosimetry using GafChromic TM films. The analysis of the films showed for the film in the center plane an excellent conformity of the 75% isodose line used to circumscribe the lesion. A very good agreement between planning and measurement resulted also for isodose lines residing outside of the target volume. (orig.) [de

  4. Monitoring mutations in people: an in vivo study of people accidentally or occupationally exposed to ionizing radiation

    International Nuclear Information System (INIS)

    Glickman, B.W.

    1996-01-01

    Recent developments in molecular biology and medicine now permit the monitoring of mutation in humans 'in vivo'. The most commonly used approach, and the main one reported in this paper, is the study of mutations at the hypoxanthine phosphoribosyl transferase (hprt) locus in peripheral T-lymphocytes. This paper deals with evidence from the radiological accident in Goiania, Brazil (where several hundred people were accidentally exposed to cesium-137), from a study of Soviet cosmonauts, and from monozygotic twins. The conclusions from Brazil are: mutation at hprt increases with age and is higher in smokers; in adults a linear dose response was found; no radiation-induced mutational fingerprint was found; children are particularly sensitive; the level of mutation dropped over several years (probably reflecting natural T-cell turnover). The conclusions from cosmonauts are: each cosmonaut had a significantly above-average level of mutation, but this may not be due to radiation at all; no 'fingerprint' was found, and there was no apparent dependence on dose. The study of twins showed a very strong correlation of mutant frequencies between one twin and the other, but this correlation decreased with age, presumably due to environmental effects. 1 tab., 2 figs

  5. Raman micro-spectroscopy analysis of human lens epithelial cells exposed to a low-dose-range of ionizing radiation

    Science.gov (United States)

    Allen, Christian Harry; Kumar, Achint; Qutob, Sami; Nyiri, Balazs; Chauhan, Vinita; Murugkar, Sangeeta

    2018-01-01

    Recent findings in populations exposed to ionizing radiation (IR) indicate dose-related lens opacification occurs at much lower doses (micro-spectroscopy was used to investigate the effects of varying doses of radiation, ranging from 0.01 Gy to 5 Gy, on human lens epithelial (HLE) cells which were chemically fixed 24 h post-irradiation. Raman spectra were acquired from the nucleus and cytoplasm of the HLE cells. Spectra were collected from points in a 3  ×  3 grid pattern and then averaged. The raw spectra were preprocessed and principal component analysis followed by linear discriminant analysis was used to discriminate between dose and control for 0.25, 0.5, 2, and 5 Gy. Using leave-one-out cross-validation accuracies of greater than 74% were attained for each dose/control combination. The ultra-low doses 0.01 and 0.05 Gy were included in an analysis of band intensities for Raman bands found to be significant in the linear discrimination, and an induced repair model survival curve was fit to a band-difference-ratio plot of this data, suggesting HLE cells undergo a nonlinear response to low-doses of IR. A survival curve was also fit to clonogenic assay data done on the irradiated HLE cells, showing a similar nonlinear response.

  6. Examination of gene expression in mice exposed to low dose radiation using affymetrix cDNA microarrays

    Energy Technology Data Exchange (ETDEWEB)

    Morris, D.; Knox, D.; Lavoie, J.; Lemon, J.; Boreham, D. [McMaster Univ., Hamilton, Ontario (Canada)

    2005-07-01

    'Full text:' Gamma radiation acts via the indirect effect to damage cells by producing reactive oxygen species (ROS). These ROS are capable damaging macromolecules and, altering signal pathways and gene transcription. Cells have evolved enzymes and mechanisms to scavenge ROS and repair oxidative damage. Microarrays allow the survey of the gene transcription activity of thousands of genes simultaneously. Messenger RNA is extracted from cells, hybridized with the complementary DNA (cDNA) of a microarray chip, and examined with a chip reader. Affymetrix microarray chips have been produced by the CSCHAH in Winnipeg containing 26000 murine genes. Groups of female mice have been exposed to low dose whole body chronic gamma radiation exposures of 0,50,100, and 120 mGy, corresponding to 15,30,60, and 75 weeks, respectively. MRNA from mice brain tissue has been extracted, isolated, converted to cDNA and labeled. Gene expression in each irradiated mouse was compared to the pooled expression of the control mice. Analysis of gene expression levels are performed with microarray analytical software, Array Pro by Media Cybernetics, and powerful statistical software, BRB microarray tools. Differences in gene expressions, focusing on genes for cytokines, DNA repair mechanisms, immuno-modulators, apoptosis pathways, and enzymatic anti-oxidant systems, are being examined and will be reported. (author)

  7. Genomic Profiling of a Human Leukemic Monocytic Cell-Line (THP-1 Exposed to Alpha Particle Radiation

    Directory of Open Access Journals (Sweden)

    Vinita Chauhan

    2012-01-01

    Full Text Available This study examined alpha (α- particle radiation effects on global changes in gene expression in human leukemic monocytic cells (THP-1 for the purposes of mining for candidate biomarkers that could be used for the development of a biological assessment tool. THP-1 cells were exposed to α-particle radiation at a dose range of 0 to 1.5 Gy. Twenty-four hours and three days after exposure gene expression was monitored using microarray technology. A total of 16 genes were dose responsive and classified as early onset due to their expression 24 h after exposure. Forty-eight transcripts were dose responsive and classified as late-onset as they were expressed 72 h after exposure. Among these genes, 6 genes were time and dose responsive and validated further using alternate technology. These transcripts were upregulated and associated with biological processes related to immune function, organelle stability and cell signalling/communication. This panel of genes merits further validation to determine if they are strong candidate biomarkers indicative of α-particle exposure.

  8. Factors predicting radiation pneumonitis in locally advanced non-small cell lung cancer

    International Nuclear Information System (INIS)

    Kim, Myung Soo; Lee, Ji Hae; Ha, Bo Ram; Lee, Re Na

    2011-01-01

    Thoracic radiotherapy is a major treatment modality of stage III non-small cell lung cancer. The normal lung tissue is sensitive to radiation and radiation pneumonitis is the most important dose-limiting complication of thoracic radiation therapy. This study was performed to identify the clinical and dosimetric parameters related to the risk of radiation pneumonitis after definitive radiotherapy in stage III non-small cell cancer patients. The medical records were reviewed for 49 patients who completed definitive radiation therapy for locally advanced non-small cell lung cancer from August 2000 to February 2010. Radiation therapy was delivered with the daily dose of 1.8 Gy to 2.0 Gy and the total radiation dose ranged from 50.0 Gy to 70.2 Gy (median, 61.2 Gy). Elective nodal irradiation was delivered at a dose of 45.0 Gy to 50.0 Gy. Seven patients (14.3%) were treated with radiation therapy alone and forty two patients (85.7%) were treated with chemotherapy either sequentially or concurrently. Twenty-five cases (51.0%) out of 49 cases experienced radiation pneumonitis. According to the radiation pneumonitis grade, 10 (20.4%) were grade 1, 9 (18.4%) were grade 2, 4 (8.2%) were grade 3, and 2 (4.1%) were grade 4. In the univariate analyses, no clinical factors including age, sex, performance status, smoking history, underlying lung disease, tumor location, total radiation dose and chemotherapy were associated with grade ≥2 radiation pneumonitis. In the subgroup analysis of the chemotherapy group, concurrent rather than sequential chemotherapy was significantly related to grade ≥2 radiation pneumonitis comparing sequential chemotherapy. In the univariate analysis with dosimetric factors, mean lung dose (MLD), V20, V30, V40, MLDipsi, V20ipsi, V30ipsi, and V40ipsi were associated with grade ≥2 radiation pneumonitis. In addition, multivariate analysis showed that MLD and V30 were independent predicting factors for grade ≥2 radiation pneumonitis. Concurrent

  9. Mortality study of Canadian military personnel exposed to radiation: atomic test blasts and Chalk River nuclear reactor clean-ups, 1950's

    International Nuclear Information System (INIS)

    Raman, S.; Dulberg, C.S.; Spasoff, R.A.

    1984-08-01

    This report describes a historical cohort study of the group of Canadian military personnel exposed to radiation in the 1950s at atomic bomb test blasts in the U.S. and Australia, and at clean-up operations at the Chalk River Nuclear Laboratories. Overall and cause-specific mortality in the exposed group was compared to that of the control cohort of unexposed military personnel, matched on age, service, rank and trade. Analyses indicated no elevation in the exposed cohort, in overall or cause-specific mortality due to diseases associated with radiation. Since this study was restricted to an investigation of mortality, we must stress that we cannot generalize these results or conclusions to current morbidity experienced by the exposed cohort

  10. Cancer risk of low dose/low dose rate radiation: a meta-analysis of cancer data of mammals exposed to low doses of radiation

    International Nuclear Information System (INIS)

    Ogata, Hiromitsu; Magae, Junji

    2008-01-01

    Full text: Linear No Threshold (LNT) model is a basic theory for radioprotection, but the adaptability of this hypothesis to biological responses at low doses or at low dose rates is not sufficiently investigated. Simultaneous consideration of the cumulative dose and the dose rate is necessary for evaluating the risk of long-term exposure to ionizing radiation at low dose. This study intends to examine several numerical relationships between doses and dose rates in biological responses to gamma radiation. Collected datasets on the relationship between dose and the incidence of cancer in mammals exposed to low doses of radiation were analysed using meta-regression models and modified exponential (MOE) model, which we previously published, that predicts irradiation time-dependent biological response at low dose rate ionizing radiation. Minimum doses of observable risk and effective doses with a variety of dose rates were calculated using parameters estimated by fitting meta-regression models to the data and compared them with other statistical models that find values corresponding to 'threshold limits'. By fitting a weighted regression model (fixed-effects meta-regression model) to the data on risk of all cancers, it was found that the log relative risk [log(RR)] increased as the total exposure dose increased. The intersection of this regression line with the x-axis denotes the minimum dose of observable risk. These estimated minimum doses and effective doses increased with decrease of dose rate. The goodness of fits of MOE-model depended on cancer types, but the total cancer risk is reduced when dose rates are very low. The results suggest that dose response curve for cancer risk is remarkably affected by dose rate and that dose rate effect changes as a function of dose rate. For scientific discussion on the low dose exposure risk and its uncertainty, the term 'threshold' should be statistically defined, and dose rate effects should be included in the risk

  11. Hepatic transcriptional responses in Atlantic salmon (Salmo salar) exposed to gamma radiation and depleted uranium singly and in combination

    Energy Technology Data Exchange (ETDEWEB)

    Song, You, E-mail: yso@niva.no [Norwegian University of Life Sciences (NMBU), Faculty of Environmental Science and Technology, Department of Environmental Sciences (IMV), Centre for Environmental Radioactivity - CERAD, P.O. Box 5003, N-1432 Ås (Norway); Norwegian Institute for Water Research (NIVA), Gaustadalléen 21, N-0349 Oslo (Norway); Salbu, Brit; Teien, Hans-Christian [Norwegian University of Life Sciences (NMBU), Faculty of Environmental Science and Technology, Department of Environmental Sciences (IMV), Centre for Environmental Radioactivity - CERAD, P.O. Box 5003, N-1432 Ås (Norway); Evensen, Øystein [Norwegian University of Life Sciences (NMBU), Department of Basic Sciences and Aquatic Medicine, P.O. Box 8146 Dep., N-0033 Oslo (Norway); Lind, Ole Christian [Norwegian University of Life Sciences (NMBU), Faculty of Environmental Science and Technology, Department of Environmental Sciences (IMV), Centre for Environmental Radioactivity - CERAD, P.O. Box 5003, N-1432 Ås (Norway); Rosseland, Bjørn Olav [Norwegian University of Life Sciences (NMBU), Faculty of Environmental Science and Technology, Department of Environmental Sciences (IMV), Centre for Environmental Radioactivity - CERAD, P.O. Box 5003, N-1432 Ås (Norway); Norwegian University of Life Sciences (NMBU), Department of Ecology and Natural Resource Management (INA), P.O. Box 5003, N-1432 Ås (Norway); and others

    2016-08-15

    Radionuclides are a special group of substances posing both radiological and chemical hazards to organisms. As a preliminary approach to understand the combined effects of radionuclides, exposure studies were designed using gamma radiation (Gamma) and depleted uranium (DU) as stressors, representing a combination of radiological (radiation) and chemical (metal) exposure. Juvenile Atlantic salmon (Salmo salar) were exposed to 70 mGy external Gamma dose delivered over the first 5 h of a 48 h period (14 mGy/h), 0.25 mg/L DU were exposed continuously for 48 h and the combination of the two stressors (Combi). Water and tissue concentrations of U were determined to assess the exposure quality and DU bioaccumulation. Hepatic gene expression changes were determined using microarrays in combination with quantitative real-time reverse transcription polymerase chain reaction (qPCR). Effects at the higher physiological levels were determined as plasma glucose (general stress) and hepatic histological changes. The results show that bioaccumulation of DU was observed after both single DU and the combined exposure. Global transcriptional analysis showed that 3122, 2303 and 3460 differentially expressed genes (DEGs) were significantly regulated by exposure to gamma, DU and Combi, respectively. Among these, 349 genes were commonly regulated by all treatments, while the majority was found to be treatment-specific. Functional analysis of DEGs revealed that the stressors displayed similar mode of action (MoA) across treatments such as induction of oxidative stress, DNA damage and disturbance of oxidative phosphorylation, but also stressor-specific mechanisms such as cellular stress and injury, metabolic disorder, programmed cell death, immune response. No changes in plasma glucose level as an indicator of general stress and hepatic histological changes were observed. Although no direct linkage was successfully established between molecular responses and adverse effects at the organism

  12. Hepatic transcriptional responses in Atlantic salmon (Salmo salar) exposed to gamma radiation and depleted uranium singly and in combination

    International Nuclear Information System (INIS)

    Song, You; Salbu, Brit; Teien, Hans-Christian; Evensen, Øystein; Lind, Ole Christian; Rosseland, Bjørn Olav

    2016-01-01

    Radionuclides are a special group of substances posing both radiological and chemical hazards to organisms. As a preliminary approach to understand the combined effects of radionuclides, exposure studies were designed using gamma radiation (Gamma) and depleted uranium (DU) as stressors, representing a combination of radiological (radiation) and chemical (metal) exposure. Juvenile Atlantic salmon (Salmo salar) were exposed to 70 mGy external Gamma dose delivered over the first 5 h of a 48 h period (14 mGy/h), 0.25 mg/L DU were exposed continuously for 48 h and the combination of the two stressors (Combi). Water and tissue concentrations of U were determined to assess the exposure quality and DU bioaccumulation. Hepatic gene expression changes were determined using microarrays in combination with quantitative real-time reverse transcription polymerase chain reaction (qPCR). Effects at the higher physiological levels were determined as plasma glucose (general stress) and hepatic histological changes. The results show that bioaccumulation of DU was observed after both single DU and the combined exposure. Global transcriptional analysis showed that 3122, 2303 and 3460 differentially expressed genes (DEGs) were significantly regulated by exposure to gamma, DU and Combi, respectively. Among these, 349