DNA-repair after irradiation of cells with gamma-rays and neutrons

International Nuclear Information System (INIS)

Altmann, H.

1975-11-01

The structural alterations of calf thymus DNA produced by neutron or gamma irradiation were observed by absorption spectra, sedimentation rate and viscosity measurements. Mixed neutron-gamma irradiation produced fewer single and double strand breaks compared with pure gamma irradiation. RBE-values for mixed neutron-gamma radiation were less than 1, and DNA damage decreased with increasing neutron dose rate. Repair processes of DNA occuring after irradiation were measured in mouse spleen suspensions and human lymphocytes using autoradiographic methods and gradient centrifugations. The number of labelled cells was smaller after mixed neutron-gamma irradiation than after gamma irradiation. The rejoining of strand breaks in alkaline and neutral sucrose was more efficient after gamma irradiation than after mixed neutron-gamma irradiation. Finally, the effect of detergents Tween 80 and Nonident P40 on unscheduled DNA synthesis was studied by autoradiography after mixed neutron-gamma irradiation (Dn=5 krad). The results showed that the DNA synthesis was inhibited by detergent solutions of 0.002%

Q{sub {gamma}-H2AX}, an analysis method for partial-body radiation exposure using {gamma}-H2AX in non-human primate lymphocytes

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Redon, Christophe E., E-mail: redonc@mail.nih.gov [NIH, NCI, CCR, Laboratory of Molecular Pharmacology, Bethesda, MD 20892 (United States); Nakamura, Asako J.; Gouliaeva, Ksenia [NIH, NCI, CCR, Laboratory of Molecular Pharmacology, Bethesda, MD 20892 (United States); Rahman, Arifur; Blakely, William F. [Armed Forces Radiobiology Research Institute, Uniformed Services University, Bethesda, MD 20889-5603 (United States); Bonner, William M. [NIH, NCI, CCR, Laboratory of Molecular Pharmacology, Bethesda, MD 20892 (United States)

2011-09-15

We previously used the {gamma}-H2AX assay as a biodosimeter for total-body irradiation (TBI) exposure ({gamma}-rays) in a rhesus macaque (Macaca mulatta) model. Utilizing peripheral blood lymphocytes and plucked hairs, we obtained statistically significant {gamma}-H2AX responses days after total-body exposure to 1-8.5 Gy ({sup 60}Co {gamma}-rays at 55 cGy min{sup -1}). Here, we introduce a partial-body exposure analysis method, Q{sub {gamma}-H2AX}, which is based on the number of {gamma}-H2AX foci per damaged cells as evident by having one or more {gamma}-H2AX foci per cell. Results from the rhesus monkey - TBI study were used to establish Q{sub {gamma}-H2AX} dose-response calibration curves to assess acute partial-body exposures. {gamma}-H2AX foci were detected in plucked hairs for several days after in vivo irradiation demonstrating this assay's utility for dose assessment in various body regions. The quantitation of {gamma}-H2AX may provide a robust biodosimeter for analyzing partial-body exposures to ionizing radiation in humans.

DNA double-strand break and apoptosis induction in human lymphocytes in different cycle cell phases by 60Co gamma rays and Bragg peak protons of a medical beam

International Nuclear Information System (INIS)

Khachenkova, A.A.; Boreyko, A.V.; Mozhaeva, A.V.; Chausov, V.N.; Ravnachka, I.I.; Amov, I.; Tiunchik, S.I.

2009-01-01

A comparative analysis is made of the regularities in the formation of DNA double-strand break and apoptosis induction in peripheral human blood lymphocytes in different cell cycle phases after 60 Co gamma and extended Bragg peak proton irradiation. It is shown that the formation of apoptotic cells in a lymphocyte population increases linearly in all the cell cycle stages after proton irradiation. The maximal DNA double-strand break and apoptosis yield in lymphocytes is observed in the S phase of the cell cycle

Changes in lymphocyte subsets due to local irradiation of a portion of the maxilla in mice. A study of minor population lymphocytes

Energy Technology Data Exchange (ETDEWEB)

Yamashita, Chiho; Satoh, Daigo; Yosue, Takashi [Nippon Dental Univ., Tokyo (Japan). School of Dentistry

2001-03-01

In the present study we investigates the influence of the local irradiation of a portion of the maxilla on the numbers of lymphocyte subsets in peripheral blood and spleen, specifically minor population lymphocytes ({gamma}{delta}T cells and NKT cells). Male C57BL/6 mice at 15 weeks of age were used for the experiments. In the irradiation group, a portion of the maxilla was exposed to X-ray (2.0 Gy/min, 10 Gy) and we analyzed lymphocytes using flow cytometry (anti-CD3, CD4, CD8, TCR{alpha}{beta}, TCR{gamma}{delta} and NK1.1 monoclonal antibodies), and compared the outcome to that obtained from the non-irradiation groups. The following results were obtained: In peripheral blood, CD4{sup +}SP T cells, CD8{sup +}SP T cells, {alpha}{beta} T cells, {gamma}{delta} T cells and NK cells decreased significantly on the first day and third day after irradiation. NKT cells decreased significantly on the third day after irradiation. In spleen, CD4{sup +}SP T cells, CD8{sup +}SP T cells, {alpha}{beta} T cells and {gamma}{delta} T cells decreased significantly on the first day after irradiation. NK cells and NKT cells did not change significantly after irradiation. The above results indicate that the changes in lymphocytes have a direct relationship to radiosensitivity, and the origin and distribution in lymphocyte subsets. (author)

Human gamma interferon production by cytotoxic T lymphocytes sensitized during hepatitis A virus infection

International Nuclear Information System (INIS)

Maier, K.; Gabriel, P.; Koscielniak, E.; Stierhof, Y.D.; Wiedmann, K.H.; Flehmig, B.; Vallbracht, A.

1988-01-01

The production of interferon (IFN) during a chromium-51 release assay with hepatitis A virus (HAV)-infected fibroblasts and autologous peripheral blood lymphocytes from patients with acute HAV infection was studied to determine whether IFN plays a role in immunopathogenesis of hepatitis A infection in humans. Skin fibroblasts of eight patients after acute HAV infection and from two control persons without history of current of past HAV infection were infected with HAV. Peripheral blood lymphocytes were collected at different times after the onset of icterus and tested in a chromium-51 release assay against autologous HAV-infected skin fibroblasts for their cytolytic and IFN-producing activity. The IFN produced during the assay was characterized and found to have the properties of human gamma IFN. Cytotoxicity and gamma IFN release were virus specific. The cell types responsible for both functions were characterized and found to be in the HLA-dependent T8 + lymphocyte subset. Considering that gamma IFN has an antiviral effect on persistent HAV infection in vitro and that it probably accounts for stimulation of HLA class I antigen expression on hepatocytes, these experimental results presented here demonstrate that human gamma IFN produced by HAV-specific T cells may participate in pathogenesis of hepatitis A infection in humans

Modulation of gamma ray induced chromosome aberrations in human peripheral blood lymphocytes by Hippophae rhammnoides leaf extract, SBL-1

International Nuclear Information System (INIS)

Tyagi, Anuradha; Madhu Bala

2014-01-01

Hippophae rhammnoides L. commonly known as seabuckthorn is a temperate shrub and native of Asia and Europe. It has high antioxidant potential and is known to the traditional Indian, Chinese and Tibetan medicinal system for treatment of multiple disorders viz., circulatory and digestive disorders, hepatic injuries, neoplasia etc. One time treatment with the standardized leaf extract from H. rhammnoides (SBL-1) before whole body irradiation with 60 Co (10 Gy), rendered more than 90% survival in non SBL-1 treated irradiated animals (J herbs, spices medi plants, 2009). Present study investigated the effects of SBL-1 treatment on chromosomal damage in human peripheral blood lymphocytes (PBL), with or without 60 Co-gamma-radiation. The lymphocytes were isolated from the blood drawn from different donors. The isolated lymphocytes were divided into several groups: Group 1-untreated control, Group 2-irradiated (2 Gy), Group 3, 4 and 5 were treated with different concentration of SBL-1, 30 min. after irradiation with 60 Co-gamma-rays (2 Gy). Group 6 was treated with the maximum concentration of SBL-1 used in the study. The metaphase spreading technique was used as per standard procedure to record chromosome breaks, dicentrics, acentrics and rings. The results were also recorded in terms of total aberrant metaphase and frequency of aberrant metaphase per 100 cells. In comparison to the untreated control, in the irradiated PBL culture, there was 8-fold increase in breaks, 211-folds in dicentrics, 75-folds in acentrics and 3-folds in rings (average data). SBL-1 alone at the highest concentration did not cause any significant change in number of breaks, dicentrics, acentrics and rings. The radiation induced aberrations decreased significantly by treatment with SBL-1 and the maximum decrease was observed when the cells were treated with 22μg/ml of SBL-1. These results demonstrated the anti-clastogenic activity of SBL-1 against gamma radiation induced damage. (author)

Study of the radioprotective effect of flavonoid quercetin on human lymphocytes

International Nuclear Information System (INIS)

Siqueira, Williams Nascimento de

2013-01-01

Ionizing radiation has been used in various fields of study, as medicine, industry, energy production, surgical materials sterilization, preservation and sterilization of foods, among others. These radiations may be responsible for adverse effects at molecular level in living organisms, where most important damage occurs in deoxyribonucleic acid molecule, DNA. These harmful effects caused by radiation highlights the importance of acquiring knowledge about radioprotector substances because they can act as protector of living tissue of those effects. In this research was investigated the possible radioprotective effect 'in vitro' of the flavonoid quercetin in human lymphocytes exposed to gamma radiation. At first, test was performed to evaluate the antioxidant activity of quercetin by capturing DPPH free radical molecules. Then, it was collected peripheral blood of volunteers donors. Then the samples were irradiated from linear accelerator (Siemens Primus - energy of 6 MeV and dose rate of 200 cGy/min from IMIP-PE). After samples irradiation, lymphocytes were isolated from whole blood and then the culture was carried out to obtain lymphocyte in metaphases and subsequent, analysis of chromosomal abnormalities were done at optical microscope. Statistical analysis was used Student 't' test. The results showed that quercetin at a concentration of 37.5 μM presented radioprotective against damage from gamma radiation on human lymphocytes in vitro. Have been also observed that the irradiated lymphocytes showed morphologically unchanged after undergoing the presence of the flavonoid quercetin. (author)

Human cytomegalovirus replicates in gamma-irradiated fibroblasts

International Nuclear Information System (INIS)

Shanley, J.D.

1986-01-01

Because of the unique interdependence of human cytomegalovirus (HCMV) and the physiological state of the host cell, we evaluated the ability of human foreskin fibroblasts (HFF), exposed to gamma radiation, to support HCMV growth. Irradiation of HFF with 2,500 rADS prevented cellular proliferation and suppressed cellular DNA, but not RNA or protein synthesis. Treatment of HFF cells with 2,500 rADS 6 or 48 hours prior to infection did not alter the time course or virus yield during HCMV replication. Virus plaquing efficiency in irradiated cells was comparable to that of nonirradiated cells. As judged by thymidine incorporation and BUdR inhibition of virus replication, HCMV infection induced both thymidine kinase activity and host cell DNA synthesis in irradiated cells. In addition, virus could be recovered from HFF exposed to radiation 0-2 days after infection with HCMV. These studies indicate that the damage to cells by gamma irradiation does not alter the capacity of host cells to support HCMV replication

Effect of pretreatment with venom of Apis mellifera bees on the yield of gamma-ray induced chromosome aberrations in human blood lymphocytes

International Nuclear Information System (INIS)

Varanda, E.A.; Takahashi, C.S.

1993-01-01

Venom of the honey bee Apis mellifera induced a protective effect against the induction of dicentric chromosomes by gamma radiation (2.0 Gy) in human peripheral blood lymphocytes when the cultures were treated with 0.00015 μl venom/1 ml medium 6 h before irradiation. In cultures to which the venom was added immediately before irradiation with 0.25, 1.0 and 2.0 Gy, no significant differences in number of dicentric chromosomes induced was observed when compared to cultures submitted to irradiation only. The venom did not induce clastogenic effects nor did it increase the frequency of sister chromatid exchanges. (author)

Caffeine enhanced measurement of mutagenesis by low levels of [gamma]-irradiation in human lymphocytes

Energy Technology Data Exchange (ETDEWEB)

Puck, T.P.; Johnson, R.; Waldren, C.A. (Eleanor Roosevelt Institute for Cancer Research, Denver, CO (United States)); Morse, H. (Univ. of Colorado Cancer Center, Denver, CO (United States))

1993-09-01

The well-known action of caffeine in synergizing mutagenesis (including chromosome aberrations) of agents like ionizing radiation by inhibition of cellular repair processes has been incorporated into a rapid procedure for detection of mutagenicity with high sensitivity. Effects of 5-10 rads of [gamma]-irradiation, which approximate the human lifetime dose accumulation from background radiation, can be detected in a two-day procedure using an immortalized human WBC culture. Chromosomally visible lesions are scored on cells incubated for 2 h after irradiation in the presence and absence of 1.0 mg/ml of caffeine. An eightfold amplification of scorable lesions is achieved over the action of radiation alone. This approach provides a closer approximation to absolute mutagenicity unmitigated by repair processes, which can vary in different situations. It is proposed that mutagenesis testing of this kind, using caffiene or other repair-inhibitory agents, be employed to identify mutagens in their effective concentrations to which human populations may be exposed; to detect agents such as caffeine that may synergize mutagenic actions and pose epidemiologic threats; and to discover effective anti-mutagens. Information derived from the use of such procedures may help prevent cancer and newly acquired genetic disease.

The Effect Of SEA On Long Tail Monkeys (Macaca Fascicularis) Lymphocyte Culture Gamma Ray-Irradiated In Vitro

International Nuclear Information System (INIS)

Wa'id, Abdul; Lusiyanti, Yanti

2000-01-01

Staphylococus enteroxine (SEA) is one of toxins produced by the bacterium Staphylococus aureus. In the culture, SEA has proven as a potent stimulator of lymphocytes in man event at fg/ml concentrations. This research studied the effect of SEA compared to Phytohaemagglutinine (PHA) on the peripheral blood lymphocytes culture of the long-tail monkeys. About 5 ml blood was collected from 5 monkeys and irradiated using Gamma Cell-220 P3TIR with doses of 0 (control); 1.0; 2.0; 3.0 and 4.0 Gy. The blood samples were cultured in the appropriate growth medium based on standard procedure and added with 1.0 ml (0.5 mug/ml) SEA or 0.15 ml PHA. The cultures were then incubated for 96 hours and prepared the slides. The results showed that on the unirradiated peripheral blood lymphocytes of long-tail monkeys the mitotic indices obtained using PHA and SEA are relatively similar. On the irradiated lymphocytes with doses of 1-3 Gy, the mitotic indices using SEA are relatively higher than that of PHA. Dose responses of dicentric, ring and acentric fragment of both PHA and SEA are relatively the same

PCC-ring induction in human lymphocytes exposed to gamma and neutron irradiation

Energy Technology Data Exchange (ETDEWEB)

Lamadrid B, A I; Garcia L, O [CPHR, Calle 20 No. 4113 e/41 y 47, Playa, La Habana 11300 (Cuba); Delbos, M; Voisin, P; Roy, L [Institut de Radioprotection et de Surete Nucleaire, BP 17, 92262 Fontenay-aux-Roses (France)

2006-07-01

Dose-effect curves for dose assessment in Gamma and neutron overexposures to high doses are presented in this paper for the first time in literature. The relationships were obtained by plotting the Premature Chromosome Condensation -rings (PCC-R) frequencies in PCC Iymphocytes obtained by chemical induction with Calyculin A in vitro, with radiation doses between 5 to 25 Gy. For the elaboration of these curves 9 676 PCC cells in Gl G2 and M stages were analyzed. The results were fitted to a lineal quadratic model in Gamma irradiation. For neutron irradiation the data was fitted to a lineal quadratic model up to 10 Gy and then a markedly cell cycle arrest and saturation was observed. These curves are of particular interest for victims exposed to doses exceeding 5 Gy where it is always very difficult to estimate a dose using the conventional technique. (Author)

PCC-ring induction in human lymphocytes exposed to gamma and neutron irradiation

International Nuclear Information System (INIS)

Lamadrid B, A.I.; Garcia L, O.; Delbos, M.; Voisin, P.; Roy, L.

2006-01-01

Dose-effect curves for dose assessment in Gamma and neutron overexposures to high doses are presented in this paper for the first time in literature. The relationships were obtained by plotting the Premature Chromosome Condensation -rings (PCC-R) frequencies in PCC Iymphocytes obtained by chemical induction with Calyculin A in vitro, with radiation doses between 5 to 25 Gy. For the elaboration of these curves 9 676 PCC cells in Gl G2 and M stages were analyzed. The results were fitted to a lineal quadratic model in Gamma irradiation. For neutron irradiation the data was fitted to a lineal quadratic model up to 10 Gy and then a markedly cell cycle arrest and saturation was observed. These curves are of particular interest for victims exposed to doses exceeding 5 Gy where it is always very difficult to estimate a dose using the conventional technique. (Author)

Edaravone protects human peripheral blood lymphocytes from γ-irradiation-induced apoptosis and DNA damage.

Science.gov (United States)

Chen, Liming; Liu, Yinghui; Dong, Liangliang; Chu, Xiaoxia

2015-03-01

Radiation-induced cellular injury is attributed primarily to the harmful effects of free radicals, which play a key role in irradiation-induced apoptosis. In this study, we investigated the radioprotective efficacy of edaravone, a licensed clinical drug and a powerful free radical scavenger that has been tested against γ-irradiation-induced cellular damage in cultured human peripheral blood lymphocytes in studies of various diseases. Edaravone was pre-incubated with lymphocytes for 2 h prior to γ-irradiation. It was found that pretreatment with edaravone increased cell viability and inhibited generation of γ-radiation-induced reactive oxygen species (ROS) in lymphocytes exposed to 3 Gy γ-radiation. In addition, γ-radiation decreased antioxidant enzymatic activity, such as superoxide dismutase and glutathione peroxidase, as well as the level of reduced glutathione. Conversely, treatment with 100 μM edaravone prior to irradiation improved antioxidant enzyme activity and increased reduced glutathione levels in irradiated lymphocytes. Importantly, we also report that edaravone reduced γ-irradiation-induced apoptosis through downregulation of Bax, upregulation of Bcl-2, and consequent reduction of the Bax:Bcl-2 ratio. The current study shows edaravone to be an effective radioprotector against γ-irradiation-induced cellular damage in lymphocytes in vitro. Finally, edaravone pretreatment significantly reduced DNA damage in γ-irradiated lymphocytes, as measured by comet assay (% tail DNA, tail length, tail moment, and olive tail moment) (p edaravone offers protection from radiation-induced cytogenetic alterations.

Evaluation through comet assay of DNA damage induced in human lymphocytes by alpha particles. Comparison with protons and Co-60 gamma rays

International Nuclear Information System (INIS)

Di Giorgio, M.; Kreiner, A. J.; Schuff, J. A.; Vallerga, M. B.; Taja, M. R.; Lopez, F. O.; Alvarez, D. E.; Saint Martin, G.; Burton, A.; Debray, M. E.; Kesque, J. M.; Somacal, H.; Stoliar, P.; Valda, A.; Davidson, J.; Davidson, M.; Ozafran, M. J.; Vazquez, M. E.

2004-01-01

Several techniques with different sensitivity to single-strand breaks and/or double strand breaks were applied to detect DNA breaks generated by high LET particles. Tests that assess DNA damage in single cells might be the appropriate tool to estimate damage induced by particles, facilitating the assessment of heterogeneity of damage in a cell population. The microgel electrophoresis (comet) assay is a sensitive method for measuring DNA damage in single cells. The objective of this work was to evaluate the proficiency of comet assay to assess the effect of high LET radiation on peripheral blood lymphocytes, compared to protons and Co-60 gamma rays. Materials and methods: Irradiations of blood samples were performed at TANDAR laboratory (Argentina). Thin samples of human peripheral blood were irradiated with different doses (0-2.5 Gy) of 20.2 MeV helium-4 particles in the track segment mode, at nearly constant LET. Data obtained were compared with the effect induced by a MeV protons and Co-60 gamma rays. Alkaline comet assay was applied. Comets were quantified by the Olive tail moment. Distribution of the helium-4 particle and protons were evaluated considering Poisson distribution in lymphocyte nuclei. The mean dose per nucleus per particle result 0.053 Gy for protons and 0.178 Gy for helium-4 particles. When cells are exposed to a dose of 0.1 Gy, the hit probability model predicts that 43% of the nuclei should have experienced and alpha traversal while with protons, 85% of the nuclei should be hit. The experimental results show a biphasic response for helium-4 particles (0.1 Gy), indicating the existence of two subpopulations: unhit and hit. Distributions of tail moment as a function of fluence and experimental dose for comets induced by helium-4 particles, protons and Co-60 gamma rays were analyzed. With helium-4 irradiations, lymphocyte nuclei show an Olive tail moment distribution flattened to higher tail moments a dose increase. However, for irradiations with

Gamma-H2AX as a biomarker of DNA damage induced by ionizing radiation in targeted and bystander human artificial skin models and peripheral blood lymphocytes

Science.gov (United States)

Redon, Christophe; Dickey, Jennifer; Bonner, William; Sedelnikova, Olga

Ionizing radiation (IR) exposure is inevitable. In addition to exposure from cosmic rays, the sun and radioactive substances, modern society has created new sources of radiation exposure such as space and high altitude journeys, X-ray diagnostics, radiological treatments and the increasing threat of radiobiological terrorism. For these reasons, a reliable, reproducible and sensitive assessment of dose and time exposure to IR is essential. We developed a minimally invasive diagnostic test for IR exposure based on detection of a phosphorylated variant of histone H2AX (gamma-H2AX), which occurs specifically at sites of DNA double-strand breaks (DSBs). The phosphorylation of thousands of H2AX molecules forms a gamma-H2AX focus in the chromatin flanking the DSB site that can be detected in situ. We analyzed gamma- H2AX focus formation in both directly irradiated cells as well as in un-irradiated "bystanders" in close contact with irradiated cells. In order to insure minimal invasiveness, we examined commercially available artificial skin models as a surrogate for human skin biopsies as well as peripheral blood lymphocytes. In human skin models, cells in a thin plane were microbeamirradiated and gamma-H2AX formation was measured both in irradiated and in distal bystander cells over time. In irradiated cells DSB formation reached a maximum at 15-30 minutes post- IR and then declined within several hours; all cells were affected. In marked contrast, the incidence of DSBs in bystander cells reached a maximum by 12-48 hours post-irradiation, gradually decreasing over the 7 day time course. At the maxima, 40-60% of bystander cells were affected. Similarly, we analyzed blood samples exposed to IR ex vivo at doses ranging from 0.02 to 3 Gy. The amount of DNA damage was linear in respect to radiation dose and independent of the age or sex of the blood donor. The method is highly reproducible and highly sensitive. In directly irradiated cells, the number of gamma-H2AX foci peaked

Post-irradiation treatment of human lymphocytes with spermidine reduced frequency of chromatid breaks

International Nuclear Information System (INIS)

Bocian, E.; Rosiek, O.; Ziemba-Zoltowska, B.

1978-01-01

Human lymphocyte cultures were X-irradiated with a single dose of 100 or 200 rad 46 h after phytohemagglutinin stimulation. In dose-fractionation experiments, 2h later the second dose was applied. All the cultures were harvested at 54 h after their initiation. In lymphocytes irradiated with a single dose of 200 rad, 2h post-irradiation contact with 10 -5 M exogeneous spermidine resulted in reduction of chromatid breaks by 34 %. Introduction of spermidine into culture medium for fractionation interval between the 2 doses of 100 rad reduced the frequency of chromatid breaks by 42 %. (author)

Effects of exogenous and endogenous IL-2 on irradiated human peripheral blood lymphocytes

International Nuclear Information System (INIS)

Zhang Lansheng; Wang Ninghai; Luan Meiling

1993-08-01

Human peripheral blood lymphocytes were irradiated with 1 to 40 Gy of γ-ray, and then cultured with PHA to prepare supernatant containing IL-2 for observation of kinetics of endogenous IL-2 production and reversion of lymphocyte proliferation after adding a highly purified IL-2. IL-2 activity was determined by the ability to sustain IL-2 dependent cell line (CTLL), lymphocyte proliferation was determined by 3 H-TdR incorporation and T lymphocyte subsets by monoclonal antibodies. The experimental results showed that lymphocytes exposed to 60 Co synthesized less DNA than nonirradiated lymphocytes. The inhibitory effect can partially reversed by purified IL-2 at the γ-ray dose range of 1 to 10 Gy, while irradiation with 2.5 Gy resulted in a reduction of T cells and T subsets, and increase in CD + 4 /CD + 8 ratio. The ratio of subsets recovered after adding IL-2. The kinetics of IL-2 production showed that the endogenous IL-2 production rose markedly with increasing dose of irradiation at the range of 1 to 10 Gy, and the peak of IL-2 production was at the γ-ray dose of 10 Gy

Melatonin may play a role in modulation of bax and bcl-2 expression levels to protect rat peripheral blood lymphocytes from gamma irradiation-induced apoptosis

International Nuclear Information System (INIS)

Mohseni, Mehran; Mihandoost, Ehsan; Shirazi, Alireza; Sepehrizadeh, Zargham; Bazzaz, Javad Tavakkoly; Ghazi-khansari, Mahmoud

2012-01-01

The close relationship between free radicals effects and apoptosis process has been proved. Melatonin has been reported as a direct free radical scavenger. We investigated the capability of melatonin in the modification of radiation-induced apoptosis and apoptosis-associated upstream regulators expression in rat peripheral blood lymphocytes. Rats were irradiated with a single whole body Cobalt 60-gamma radiation dose of 8 Gy at a dose rate of 101 cGy/min with or without melatonin pretreatments at different concentrations of 10 and 100 mg/kg body weight. The rats were divided into eight groups of control, irradiation-only, vehicle-only, vehicle plus irradiation, 10 mg/kg melatonin alone, 10 mg/kg melatonin plus irradiation, 100 mg/kg melatonin alone and 100 mg/kg melatonin plus irradiation. Rats were given an intraperitoneal (IP) injection of melatonin or the same volume of vehicle alone 1 h prior to irradiation. Blood samples were taken 4, 24, 48 and 72 h after irradiation for evaluation of flow cytometric analysis of apoptotic lymphocytes using Annexin V/PI assay and measurement of bax and bcl-2 expression using quantitative real-time PCR (RT 2 qPCR). Irradiation-only and vehicle plus irradiation showed an increase in the percentage of apoptotic lymphocytes significantly different from control group (P < 0.01), while melatonin pretreatments in a dose-dependent manner reduced it as compared with the irradiation-only and vehicle plus irradiation groups (P < 0.01) in all time points. This reduced apoptosis by melatonin was related to the downregulation of bax, upregulation of bcl-2, and therefore reduction of bax/bcl-2 ratio. Our results suggest that melatonin in these doses may provide modulation of bax and bcl-2 expression as well as bax/bcl-2 ratio to protect rat peripheral blood lymphocytes from gamma irradiation-induced apoptosis.

Melatonin may play a role in modulation of bax and bcl-2 expression levels to protect rat peripheral blood lymphocytes from gamma irradiation-induced apoptosis

Energy Technology Data Exchange (ETDEWEB)

Mohseni, Mehran [Department of Radiology and Medical Physics, Faculty of Paramedicine, Kashan University of Medical Sciences, Kashan (Iran, Islamic Republic of); Mihandoost, Ehsan, E-mail: mihandoost.e@gmail.com [Department of Medical Radiation Engineering, Science and Research Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of); Shirazi, Alireza [Department of Medical Physics and Biomedical Engineering, Faculty of Medicine, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Sepehrizadeh, Zargham [Department of Pharmaceutical Biotechnology, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Bazzaz, Javad Tavakkoly [Department of Medical Genetics, Faculty of Medicine, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Ghazi-khansari, Mahmoud [Department of Pharmacology, Faculty of Medicine, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of)

2012-10-15

The close relationship between free radicals effects and apoptosis process has been proved. Melatonin has been reported as a direct free radical scavenger. We investigated the capability of melatonin in the modification of radiation-induced apoptosis and apoptosis-associated upstream regulators expression in rat peripheral blood lymphocytes. Rats were irradiated with a single whole body Cobalt 60-gamma radiation dose of 8 Gy at a dose rate of 101 cGy/min with or without melatonin pretreatments at different concentrations of 10 and 100 mg/kg body weight. The rats were divided into eight groups of control, irradiation-only, vehicle-only, vehicle plus irradiation, 10 mg/kg melatonin alone, 10 mg/kg melatonin plus irradiation, 100 mg/kg melatonin alone and 100 mg/kg melatonin plus irradiation. Rats were given an intraperitoneal (IP) injection of melatonin or the same volume of vehicle alone 1 h prior to irradiation. Blood samples were taken 4, 24, 48 and 72 h after irradiation for evaluation of flow cytometric analysis of apoptotic lymphocytes using Annexin V/PI assay and measurement of bax and bcl-2 expression using quantitative real-time PCR (RT{sup 2}qPCR). Irradiation-only and vehicle plus irradiation showed an increase in the percentage of apoptotic lymphocytes significantly different from control group (P < 0.01), while melatonin pretreatments in a dose-dependent manner reduced it as compared with the irradiation-only and vehicle plus irradiation groups (P < 0.01) in all time points. This reduced apoptosis by melatonin was related to the downregulation of bax, upregulation of bcl-2, and therefore reduction of bax/bcl-2 ratio. Our results suggest that melatonin in these doses may provide modulation of bax and bcl-2 expression as well as bax/bcl-2 ratio to protect rat peripheral blood lymphocytes from gamma irradiation-induced apoptosis.

Micronuclei induced by fast neutrons versus 60Co gamma-rays in human peripheral blood lymphocytes.

Science.gov (United States)

Vral, A; Verhaegen, F; Thierens, H; De Ridder, L

1994-03-01

Here we compared the effectiveness of neutrons ( = 5.5 MeV) versus 60Co gamma-rays in producing micronuclei (MN) in human lymphocytes. To obtain dose-response data, blood samples of six donors were irradiated with doses ranging from 0.1 to 5 Gy for gamma-rays and 0.1-3 Gy for neutrons. A linear dependence of MN yield with dose was found for fast neutrons while for gamma-rays a nonlinear dependence existed. For both radiation qualities no significant interindividual differences were found. Derived relative biological effectiveness values decreased with increasing dose. The MN frequency distributions were overdispersed with respect to the Poisson distribution, with neutrons showing higher dispersion values than with gamma-rays. To compare the repair kinetics of both radiation qualities split-dose experiments were performed. A dose of 4 Gy gamma-rays (3 Gy neutrons) was delivered either as a single exposure or in two equal fractions separated by time intervals ranging from 30 min to 10 h (30 min to 7 h for neutrons). The data showed for gamma-rays a significant decline (30% +/- 10%) in MN yield with interfraction time due to repair of DNA damage. This repair is a continuous process starting almost immediately after the first of the two doses and lasting 3-5 h. For fast neutrons no decline was observed indicating irreparable damage.

Dose-rate effects for apoptosis and micronucleus formation in gamma-irradiated human lymphocytes

Energy Technology Data Exchange (ETDEWEB)

Boreham, D.R.; Dolling, J.-A.; Maves, S.R. [Atomic Energy of Canada Limited, Chalk River, Ontario (Canada); Siwarungsun, N. [Chulalongkorn Univ., Bangkok (Thailand); Mitchel, R.E.J. [Atomic Energy of Canada Limited, Chalk River, Ontario (Canada)

2000-07-01

We have compared dose-rate effects for {gamma}-radiation-induced apoptosis and micronucleus formation in human lymphocytes. Long-term assessment of individual radiation-induced apoptosis showed little intraindividual variation but significant interindividual variation. The effectiveness of radiation exposure to cause apoptosis or micronucleus formation was reduced by low-dose-rate exposures, but the reduction was apparent at different dose rates for these two end points. Micronucleus formation showed a dose-rate effect when the dose rate was lowered to 0.29 cGy/min, but there was no accompanying cell cycle delay. A further increase in the dose-rate effect was seen at 0.15 cGy/min, but was now accompanied by cell cycle delay. There was no dose-rate effect for the induction of apoptosis until the dose rate was reduced to 0.15 cGy/min, indicating that the mechanisms or signals for processing radiation-induced lesions for these two end points must be different at least in part. There appear to be two mechanisms that contribute to the dose-rate effect for micronucleus formation. One of these does not affect binucleate cell frequency and occurs at dose rates higher than that required to produce a dose-rate effect for apoptosis, and one affects binucleate cell frequency, induced only at the very low dose rate which coincidentally produces a dose-rate effect for apoptosis. Since the dose rate at which cells showed reduced apoptosis as well as a further reduction in micronucleus formation was very low, we conclude that the processing of the radiation-induced lesions that induce apoptosis, and some micronuclei, is very slow in quiescent and PHA-stimulated lymphocytes, respectively. (author)

The profiles of gamma-H2AX along with ATM/DNA-PKcs activation in the lymphocytes and granulocytes of rat and human blood exposed to gamma rays.

Science.gov (United States)

Wang, Jing; Yin, Lina; Zhang, Junxiang; Zhang, Yaping; Zhang, Xuxia; Ding, Defang; Gao, Yun; Li, Qiang; Chen, Honghong

2016-08-01

Establishing a rat model suitable for γ-H2AX biodosimeter studies has important implications for dose assessment of internal radionuclide contamination in humans. In this study, γ-H2AX, p-ATM and p-DNA-PKcs foci were enumerated using immunocytofluorescence method, and their protein levels were measured by Western blot in rat blood lymphocytes and granulocytes exposed to γ-rays compared with human blood lymphocytes and granulocytes. It was found that DNA double-strand break repair kinetics and linear dose responses in rat lymphocytes were similar to those observed in the human counterparts. Moreover, radiation induced clear p-ATM and p-DNA-PKcs foci formation and an increase in ratio of co-localization of p-ATM or p-DNA-PKcs with γ-H2AX foci in rat lymphocytes similar to those of human lymphocytes. The level of γ-H2AX protein in irradiated rat and human lymphocytes was significantly reduced by inhibitors of ATM and DNA-PKcs. Surprisingly, unlike human granulocytes, rat granulocytes with DNA-PKcs deficiency displayed a rapid accumulation, but delayed disappearance of γ-H2AX foci with essentially no change from 10 h to 48 h post-irradiation. Furthermore, inhibition of ATM activity in rat granulocytes also decreased radiation-induced γ-H2AX foci formation. In comparison, human granulocytes showed no response to irradiation regarding γ-H2AX, p-ATM or p-DNA-PKcs foci. Importantly, incidence of γ-H2AX foci in lymphocytes after total-body radiation of rats was consistent with that of in vitro irradiation of rat lymphocytes. These findings show that rats are a useful in vivo model for validation of γ-H2AX biodosimetry for dose assessment in humans. ATM and DNA-PKcs participate together in DSB repair in rat lymphocytes similar to that of human lymphocytes. Further, rat granulocytes, which have the characteristic of delayed disappearance of γ-H2AX foci in response to radiation, may be a useful experimental system for biodosimetry studies.

The profiles of gamma-H2AX along with ATM/DNA-PKcs activation in the lymphocytes and granulocytes of rat and human blood exposed to gamma rays

Energy Technology Data Exchange (ETDEWEB)

Wang, Jing; Yin, Lina; Zhang, Junxiang; Zhang, Yaping; Zhang, Xuxia; Ding, Defang; Gao, Yun; Li, Qiang; Chen, Honghong [Fudan University, Department of Radiation Biology, Institute of Radiation Medicine, Shanghai (China)

2016-08-15

Establishing a rat model suitable for γ-H2AX biodosimeter studies has important implications for dose assessment of internal radionuclide contamination in humans. In this study, γ-H2AX, p-ATM and p-DNA-PKcs foci were enumerated using immunocytofluorescence method, and their protein levels were measured by Western blot in rat blood lymphocytes and granulocytes exposed to γ-rays compared with human blood lymphocytes and granulocytes. It was found that DNA double-strand break repair kinetics and linear dose responses in rat lymphocytes were similar to those observed in the human counterparts. Moreover, radiation induced clear p-ATM and p-DNA-PKcs foci formation and an increase in ratio of co-localization of p-ATM or p-DNA-PKcs with γ-H2AX foci in rat lymphocytes similar to those of human lymphocytes. The level of γ-H2AX protein in irradiated rat and human lymphocytes was significantly reduced by inhibitors of ATM and DNA-PKcs. Surprisingly, unlike human granulocytes, rat granulocytes with DNA-PKcs deficiency displayed a rapid accumulation, but delayed disappearance of γ-H2AX foci with essentially no change from 10 h to 48 h post-irradiation. Furthermore, inhibition of ATM activity in rat granulocytes also decreased radiation-induced γ-H2AX foci formation. In comparison, human granulocytes showed no response to irradiation regarding γ-H2AX, p-ATM or p-DNA-PKcs foci. Importantly, incidence of γ-H2AX foci in lymphocytes after total-body radiation of rats was consistent with that of in vitro irradiation of rat lymphocytes. These findings show that rats are a useful in vivo model for validation of γ-H2AX biodosimetry for dose assessment in humans. ATM and DNA-PKcs participate together in DSB repair in rat lymphocytes similar to that of human lymphocytes. Further, rat granulocytes, which have the characteristic of delayed disappearance of γ-H2AX foci in response to radiation, may be a useful experimental system for biodosimetry studies. (orig.)

The profiles of gamma-H2AX along with ATM/DNA-PKcs activation in the lymphocytes and granulocytes of rat and human blood exposed to gamma rays

International Nuclear Information System (INIS)

Wang, Jing; Yin, Lina; Zhang, Junxiang; Zhang, Yaping; Zhang, Xuxia; Ding, Defang; Gao, Yun; Li, Qiang; Chen, Honghong

2016-01-01

Establishing a rat model suitable for γ-H2AX biodosimeter studies has important implications for dose assessment of internal radionuclide contamination in humans. In this study, γ-H2AX, p-ATM and p-DNA-PKcs foci were enumerated using immunocytofluorescence method, and their protein levels were measured by Western blot in rat blood lymphocytes and granulocytes exposed to γ-rays compared with human blood lymphocytes and granulocytes. It was found that DNA double-strand break repair kinetics and linear dose responses in rat lymphocytes were similar to those observed in the human counterparts. Moreover, radiation induced clear p-ATM and p-DNA-PKcs foci formation and an increase in ratio of co-localization of p-ATM or p-DNA-PKcs with γ-H2AX foci in rat lymphocytes similar to those of human lymphocytes. The level of γ-H2AX protein in irradiated rat and human lymphocytes was significantly reduced by inhibitors of ATM and DNA-PKcs. Surprisingly, unlike human granulocytes, rat granulocytes with DNA-PKcs deficiency displayed a rapid accumulation, but delayed disappearance of γ-H2AX foci with essentially no change from 10 h to 48 h post-irradiation. Furthermore, inhibition of ATM activity in rat granulocytes also decreased radiation-induced γ-H2AX foci formation. In comparison, human granulocytes showed no response to irradiation regarding γ-H2AX, p-ATM or p-DNA-PKcs foci. Importantly, incidence of γ-H2AX foci in lymphocytes after total-body radiation of rats was consistent with that of in vitro irradiation of rat lymphocytes. These findings show that rats are a useful in vivo model for validation of γ-H2AX biodosimetry for dose assessment in humans. ATM and DNA-PKcs participate together in DSB repair in rat lymphocytes similar to that of human lymphocytes. Further, rat granulocytes, which have the characteristic of delayed disappearance of γ-H2AX foci in response to radiation, may be a useful experimental system for biodosimetry studies. (orig.)

The comparison of radiosensitivity of human lymphocytes stimulated with PHA Con A and PWM

International Nuclear Information System (INIS)

Geng Yongzhi; Su Liaoyuan

1989-11-01

The transformation, DNA strand breaks and its repair ability in human peripheral blood lymphocytes stimulated with PHA, Con A and PWM were respectively assessed following exposure to 60 Co gamma rays by 3 H-thymidine uptake and hydroxylapatite chromatography. It was showed the transformation of lymphocytes stimulated with PHA, Con A and PWM were suppressed by gamma rays and the dose-effect curves were biphase within the range of 0∼8 Gy. The lymphocytes stimulated with PWM was the most resistant to gamma rays. The extent of DNA strand breaks in lymphocytes induced by gamma rays was linearly related to the dose within the range of 0∼30 Gy and was identical in three kinds of lymphocytes. After post-irradiation incubation of 37 deg C, the DNA strand breaks could be repaired incompletely and after maxium repair the strand breaks were observed again. The repair ratio of strand breaks in the lymphocytes stimulated with PWM was the highest in the cells with three mitogens. The results showed that the difference of radiation effect on the transformation is probably related to the repair ability of DNA strand breaks

Radio response of human lymphocytes pretreated with boron and gadoliniums assessed by the, comet assay

International Nuclear Information System (INIS)

Kim, J. K.; Park, T. W.; Cebulska-Wasiewska, A.; Nili, M.

2009-01-01

Boron and gadolinium are among the nuclides that hold a unique property of being a neutron capture therapy agent. Neutron beams have often a considerable portion of gamma rays with fast neutrons. Gamma rays, as beam contaminants, can cause considerable damage to normal tissues even if such tissues do contain high boron concentrations. Materials and Methods: The modification of radio response in human lymphocytes pretreated with boron or gadolinium compound was studied by assessing the DNA damage using single cell gel electrophoresis, the comet assay. The lymphocytes from the human peripheral blood were irradiated with 0, 1, 2 and 4 Gy of gamma rays from a 60 Co isotopic source with or without pretreatment of boron or gadolinium compound for 10 minutes at 4 d egree C . Post-irradiation procedures included slide preparation, cell-lysing, unwinding and electrophoresis, neutralization, staining, and analytic steps, gel electrophoresis. Results: The results indicate that pretreatment with boron compound (50 n M or 250 n M of 10 B) is effective in reducing the radiosensitivity of the lymphocyte DNA. Conversely, pretreatment with gadolinium compound (50 n M) led to a dose-dependent increase in the radiosensitivity, most prominently with a dose of 4 Gy (P<0.001). Furthermore, when the lymphocytes were pretreated with a Combined mixture (1:1) of boron (250 n M) and gadolinium (50 n M) compounds, the reduced radiosensitivity was also observed.

Genomic instability after targeted irradiation of human lymphocytes: Evidence for inter-individual differences under bystander conditions

International Nuclear Information System (INIS)

Kadhim, Munira A.; Lee, Ryonfa; Moore, Stephen R.; Macdonald, Denise A.; Chapman, Kim L.; Patel, Gaurang; Prise, Kevin M.

2010-01-01

Environmental 222 radon exposure is a human health concern, and many studies demonstrate that very low doses of high LET α-particle irradiation initiate deleterious genetic consequences in both irradiated and non-irradiated bystander cells. One consequence, radiation-induced genomic instability (RIGI), is a hallmark of tumorigenesis and is often assessed by measuring delayed chromosomal aberrations. We utilised a technique that facilitates transient immobilization of primary lymphocytes for targeted microbeam irradiation and have reported that environmentally relevant doses, e.g. a single 3 He 2+ particle traversal to a single cell, are sufficient to induce RIGI. Herein we sought to determine differences in radiation response in lymphocytes isolated from five healthy male donors. Primary lymphocytes were irradiated with a single particle per cell nucleus. We found evidence for inter-individual variation in radiation response (RIGI, measured as delayed chromosome aberrations). Although this was not highly significant, it was possibly masked by high levels of intra-individual variation. While there are many studies showing a link between genetic predisposition and RIGI, there are few studies linking genetic background with bystander effects in normal human lymphocytes. In an attempt to investigate inter-individual variation in the induction of bystander effects, primary lymphocytes were irradiated with a single particle under conditions where fractions of the population were traversed. We showed a marked genotype-dependent bystander response in one donor after exposure to 15% of the population. The findings may also be regarded as a radiation-induced genotype-dependent bystander effect triggering an instability phenotype.

Genomic instability after targeted irradiation of human lymphocytes: Evidence for inter-individual differences under bystander conditions

Energy Technology Data Exchange (ETDEWEB)

Kadhim, Munira A., E-mail: mkadhim@brookes.ac.uk [School of Life Sciences, Oxford Brookes University, Oxford OX3 0BP (United Kingdom); Lee, Ryonfa [Biophysics, GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Planckstrasse 1, D-64291 Darmstadt (Germany); Moore, Stephen R.; Macdonald, Denise A. [Radiation and Genome Stability Unit, Medical Research Council, Harwell, Oxfordshire OX11 0RD (United Kingdom); Chapman, Kim L. [School of Life Sciences, Oxford Brookes University, Oxford OX3 0BP (United Kingdom); Patel, Gaurang; Prise, Kevin M. [Centre for Cancer Research and Cell Biology, Queen' s University Belfast, Belfast BT9 7BL (United Kingdom)

2010-06-01

Environmental {sup 222}radon exposure is a human health concern, and many studies demonstrate that very low doses of high LET {alpha}-particle irradiation initiate deleterious genetic consequences in both irradiated and non-irradiated bystander cells. One consequence, radiation-induced genomic instability (RIGI), is a hallmark of tumorigenesis and is often assessed by measuring delayed chromosomal aberrations. We utilised a technique that facilitates transient immobilization of primary lymphocytes for targeted microbeam irradiation and have reported that environmentally relevant doses, e.g. a single {sup 3}He{sup 2+} particle traversal to a single cell, are sufficient to induce RIGI. Herein we sought to determine differences in radiation response in lymphocytes isolated from five healthy male donors. Primary lymphocytes were irradiated with a single particle per cell nucleus. We found evidence for inter-individual variation in radiation response (RIGI, measured as delayed chromosome aberrations). Although this was not highly significant, it was possibly masked by high levels of intra-individual variation. While there are many studies showing a link between genetic predisposition and RIGI, there are few studies linking genetic background with bystander effects in normal human lymphocytes. In an attempt to investigate inter-individual variation in the induction of bystander effects, primary lymphocytes were irradiated with a single particle under conditions where fractions of the population were traversed. We showed a marked genotype-dependent bystander response in one donor after exposure to 15% of the population. The findings may also be regarded as a radiation-induced genotype-dependent bystander effect triggering an instability phenotype.

Induction and persistence of multicentric chromosomes in cultured human peripheral blood lymphocytes following high-dose gamma irradiation

International Nuclear Information System (INIS)

Suto, Yumiko; Hirai, Momoki; Akiyama, Miho; Nakagawa, Takashi; Tominaga, Takako; Suzuki, Toshikazu; Sugiura, Nobuyuki; Yuki, Masanori; Nakayama, Fumiaki

2012-01-01

Among radiation-induced chromosome aberrations, multicentric chromosomes, as represented by dicentric chromosomes (dicentrics), are regarded as sensitive and specific biomarkers for assessing radiation dose in the 0 to 5 Gy range. The objective of this study was to characterize chromosome aberrations induced in vitro by a higher dose of radiation. Peripheral blood lymphocytes were exposed to 15 Gy gamma rays at a dose rate of 0.5 Gy/min and harvested at 48, 50, 52, 54, 56 and 72 h. The first mitotic peak appeared at 52-54 h, showing about a 6 h mitotic delay as compared with nonirradiated control cultures. Cell-cycle analysis of parallel and simultaneous cultures by sister-chromatid differentiation staining suggests that metaphase cells examined in 48-56 h cultures were in the first mitosis after culture initiation. The mean dicentric equivalent counts ranged from 9.0 to 9.3 in consecutively harvested cultures with no significant differences among them. At 72 h, about 20% of dividing cells were tetraploid, persisting with faithfully replicated unstable chromosome aberrations. The non-random distribution of replicated chromosome pairs, deduced from multicolor fluorescence in situ hybridization analysis, led us to surmise that the predominant mechanism underlying the induction of tetraploid cells is endoreduplication. These findings suggest that a high-dose in vitro irradiation applied to peripheral blood lymphocytes may affect on the replication process, in addition to structural chromosome damage. (author)

Assessment of the radioprotective effects of amifostine and melatonin on human lymphocytes irradiated with gamma-rays in vitro

International Nuclear Information System (INIS)

Kopjar, N.; Miocic, S.; Ramic, S.; Milic, M.; Viculin, T.

2005-01-01

Radioprotective effects of amifostine and melatonin on human peripheral blood irradiated with g-rays were investigated using the micronucleus (MN) assay and the analysis of sister chromatid exchanges (SCE). Duplicate blood samples were pre-treated with amifostine (7.7 mM), melatonin (2 mM) and their combination for 30 minutes. Negative controls were also included. After treatment with radioprotectors, one blood sample from each experimental group was exposed to g-rays from a 6 0C o source. The radiation dose absorbed was 2 Gy. Pre-treated irradiated blood samples showed a decrease in the total number of MN and in the number of cells with more than one MN. Moreover, they also showed significantly lower mean SCE values. Our results indicate that amifostine, melatonin and their combination in vitro have radioprotective effects on g-irradiated human peripheral blood lymphocytes, with no significant genotoxicity. Therefore, it may be reasonable to use them in combination, adjusting the doses of amifostine to achieve the best radioprotective effect with as few side effects as possible. Before employment, this combination should be extensively tested in vitro and in vivo, using the same and other biomarkers for different radiation dose and concentration ranges of both radioprotectors.(author)

Gamma-radiation-induced chromosal aberration in human lymphocytes: dose-rate effects in stimulated and non-stimulated cells

International Nuclear Information System (INIS)

Liniecki, J.; Bajerska, A.; Wyszynska, K.; Cisowska, B.

1977-01-01

Stimulated and non-stimulated human peripheral blood lymphocytes were irradiated acutely and chronically, over 24 h. Dose-effect relationships for dicentric chromosomes were established and various models were fitted to the data. At prolonged irradiations, the yield decreased in basic agreement with the linear-quadratic model of aberration induction. Dose-protraction experiments on PHA + and PHA - lymphocytes, irradiated under various conditions of oxygenation and suspension (culture medium, whole blood) showed that the rejoining time increased from about 3 h in non-stimulated cells to about 10 h after PHA stimulation, and that this retarded rejoining was most likely due to blastic transformation itself and not to other conditions of irradiation

Early morphologic and quantitative changes in mouse peripheral blood lymphocytes after low dose gamma-irradiation

International Nuclear Information System (INIS)

Gitsov, L.; Byrneva, V.; Goranov, I.

1979-01-01

The study was undertaken in an effort to establish differences in the radiosensitivity of peripheral blood lymphocytes, as a possible test for evaluation of early and discrete radiation injury. Sexually mature mice of BAIB/c line were X-irradiated with doses of 50 and 250 rad. The animals were sacrificed by blood letting 24 hours after irradiation, but 30 minutes before this each mouse was heparinized. Smears were prepared from the enriched pooled leucocyte suspensions, obtained by dextran sedimentation of the red cells. The preparations were stained with toluidin blue by the methods of Smetana and Pappenheim. Cell size, clasmatosis, nucleolar structure and degree of cytoplasmic metachromasia were determined. It was found that the lymphocytogram of animals irradiated with 50 rad was characterized by high percentage of small lymphocytes, most of them with dispersed nuclear ribonucleoproteins and minimal clasmatose activity. Irradiation with 100 rad induced a characteristical rise in lymphocyte clasmatose activity and decrease in the number of small lymphocytes. The nucleoli were bright and well delineated. The lymphocytogram of animals irradiated with higher doses (150 and 250 rad) was characterized by predomination of large lymphocytes and hyperbasophilic forms with well preserved bright nucleoli. The percentage of lymphocates with clasmatosis was below the control value. (A.B.)

Gamma radiation induced chromosal aberration in human lymphocytes: dose-rate effects in stimulated and non-stimulated cells

Energy Technology Data Exchange (ETDEWEB)

Liniecki, J; Bajerska, A; Wyszynska, K [School of Medicine, Lodz (Poland). Div. of Nuclear Medicine and Radiobiology. Medical Research Center; Cisowska, B [Copernicus Municipal Hospital, Lodz (Poland). Oncology Center. Radiotherapy Dept.

1977-05-01

Stimulated and non-stimulated human peripheral blood lymphocytes were irradiated acutely and chronically, over 24 h. Dose-effect relationships for dicentric chromosomes were established and various models were fitted to the data. At prolonged irradiations, the yield decreased in basic agreement with the linear-quadratic model of aberration induction. Dose-protraction experiments on PHA/sup +/ and PHA/sup -/ lymphocytes, irradiated under various conditions of oxygenation and suspension (culture medium, whole blood) showed that the rejoining time increased from about 3 h in non-stimulated cells to about 10 h after PHA stimulation, and that this retarded rejoining was most likely due to blastic transformation itself and not to other conditions of irradiation.

Interleukin-15 differentially enhances the expression of interferon-gamma and interleukin-4 in activated human (CD4(+))T lymphocytes

NARCIS (Netherlands)

Borger, P; Kauffman, HF; Postma, DS; Esselink, MT; Vellenga, E

In this study interleukin (IL)-15 was examined for its ability to modulate the expression of interferon-gamma (IFN-gamma) and IL-4 in activated human T lymphocytes. The effect of IL-15 was compared with IL-2 and IL-7, cytokines all known to use the IL-2 receptor gamma(C) chain. The results

Nitric oxide selectively decreases interferon-gamma expression by activated human T lymphocytes via a cGMP-independent mechanism

NARCIS (Netherlands)

Roozendaal, R; Vellenga, E; Postma, DS; De Monchy, JGR; Kauffman, HF

1999-01-01

The role of exogenous nitric oxide (NO) on the expression of interleukin (IL)-2, IL-4, IL-5 and interferon-gamma (IFN-gamma) by freshly isolated human T lymphocytes was investigated. The presence of NO, generated from any of the NO-donor compounds, S-nitroso-N-acetyl-D,L-penicillamine (NAP),

Dose and dose rate effects of whole-body gamma-irradiation: I. Lymphocytes and lymphoid organs

Science.gov (United States)

Pecaut, M. J.; Nelson, G. A.; Gridley, D. S.

2001-01-01

The major goal of part I of this study was to compare varying doses and dose rates of whole-body gamma-radiation on lymphoid cells and organs. C57BL/6 mice (n = 75) were exposed to 0, 0.5, 1.5, and 3.0 Gy gamma-rays (60Co) at 1 cGy/min (low-dose rate, LDR) and 80 cGy/min (high-dose rate, HDR) and euthanized 4 days later. A significant dose-dependent loss of spleen mass was observed with both LDR and HDR irradiation; for the thymus this was true only with HDR. Decreasing leukocyte and lymphocyte numbers occurred with increasing dose in blood and spleen at both dose rates. The numbers (not percentages) of CD3+ T lymphocytes decreased in the blood in a dose-dependent manner at both HDR and LDR. Splenic T cell counts decreased with dose only in HDR groups; percentages increased with dose at both dose rates. Dose-dependent decreases occurred in CD4+ T helper and CD8+ T cytotoxic cell counts at HDR and LDR. In the blood the percentages of CD4+ cells increased with increasing dose at both dose rates, whereas in the spleen the counts decreased only in the HDR groups. The percentages of the CD8+ population remained stable in both blood and spleen. CD19+ B cell counts and percentages in both compartments declined markedly with increasing HDR and LDR radiation. NK1.1+ natural killer cell numbers and proportions remained relatively stable. Overall, these data indicate that the observed changes were highly dependent on the dose, but not dose rate, and that cells in the spleen are more affected by dose rate than those in blood. The results also suggest that the response of lymphocytes in different body compartments may be variable.

Influence of high energy electron irradiation and gamma irradiation on the osmotic resistance of human erythrocyte membranes

International Nuclear Information System (INIS)

Catana, D.; Hategan, Alina; Moraru, Rodica; Popescu, Alina; Morariu, V. V.

1998-01-01

The effects of 5 MeV electrons and of gamma irradiation at 0 deg. C on the osmotic fragility of human erythrocyte membranes are presented. Both electron and gamma radiation in the range 0-400 Gy induced no hemolysis indicating that the membrane modifications due to radiation interaction do not reach a critical point as to cause swelling of the cells and subsequent lysis. The osmotic stress experiments performed after irradiation showed that the gamma irradiated erythrocytes exhibited an almost similar sigmoidal behavior for all irradiation doses, whereas the electron irradiated samples showed a much larger increase in hemolysis degree and, in the case of a given electron dose (100 Gy), the hemolysis was found much smaller than for the control sample (a similar behavior of the erythrocytes was found in the case of microwave irradiation at temperatures under 0 deg. C). Our experimental data suggest that electron radiation and gamma radiation have different impacts on the erythrocyte membrane fluidity, involving, probably, the different rate of energy deposition in the samples and the direct interaction of electrons with the erythrocyte membranes. (authors)

Studies on bystander effects of 14MeV neutrons in human blood lymphocytes using CBMN assay

International Nuclear Information System (INIS)

Bakkiam, D.; Arul Anantha Kumar, A.; Sonwani, Swetha; Alaguraja, E.; Mathiyarasu, R.; Baskaran, R.; Venkatraman, B.

2018-01-01

Radiation induced Bystander Effects (RIBE) in cells generally describes the phenomenon that non-irradiated cells respond as if they have themselves been irradiated upon receiving signals from directly irradiated cells, either through partnering or medium transfer. While it has been well established that bystander effects could be induced by gamma radiation and alpha-particle radiation it is still a question whether neutrons induce bystander effects or not. In view of this, experiments were carried out to quantify cytogenetic damage in human blood lymphocytes induced by neutron directly and indirectly i.e. RIBE through medium transfer method. Cytokinesis Blocked MicroNucleus (CBMN) assay was used to study DNA damage events wherein micronuclei (MN) were scored in binucleated cells. Results of MN frequency in neutron direct and indirect irradiated blood lymphocytes (bystander samples) are compared

Structural changes in chromosomes of peripheral blood lymphocytes in monkeys subjected to long-term daily irradiation

International Nuclear Information System (INIS)

Kosichenko, L.P.

1976-01-01

During the period that lasted from 4 to 11 years after the cessation of the long-term daily gamma-irradiation the frequency of chromosome rearrangements in peripheral blood lymphocytes of monkeys exceeded the control level. The number of rearrangements did not change significantly with different total irradiation doses (from 826 to 3677r). The main type of structural chromosome rearrangements were symmetrical chromosome exchanges. Abnormal cell clones in peripheral lymphocytes in monkeys irradiated with low doses exhibited no selective advantages during the periods of investigation

Signalling detection of DNA damage induced by low doses of ionizing radiation in human lymphocytes

International Nuclear Information System (INIS)

Valente, M.

2011-01-01

Individuals spontaneously present different sensitivities to ionizing radiation, measured by the severity of their post-radiotherapy side-effects. Cells from some patients with extreme clinical radiosensitivity have shown altered cellular radiosensitivity measured by different endpoints as apoptosis or DNA damage. Linking clinical and cellular sensitivity is of fundamental importance to establish a clinical test capable of predicting a person's radiosensitivity from a sample. Easily sampled, peripheral blood lymphocytes (PBL) are an appealing cellular model to study individual radiosensitivity as they have been shown to be the most radiosensitive hematopoietic cells. DNA damages and repair can be visualized by observing the kinetics of appearance and disappearance of gamma-H2AX foci on DNA double-strand breaks through immunofluorescence microscopy. The experimental strategy chosen here was to follow lymphocyte gamma-H2AX foci kinetics in response to different levels of irradiation as delayed gamma-H2AX foci disappearance has been observed in cells of individuals with high clinical radiosensitivity. For our initial study we irradiated in vitro samples of radiotherapy patients with different clinical radiosensitivities. The groups of distinct clinical sensitivities showed no corresponding differences in their cellular gamma-H2AX response. In addition, several samples were lost, mainly due to the long transportation period before being treated in our lab. To render this method usable for clinical applications, several changes were made: after improving sample viability, speed was increased by automation of image acquisition (Metasystem) and gamma-H2AX focus scoring (freeware CellProfiler). This technique was able to detect doses as low as 0.005 Gy and gave similar results to manual focus scoring. The possibility of discriminating different lymphocyte subsets (CD4, CD8 and CD19) during analysis was added to identify among the lymphocyte subsets the one producing more

Radioprotective effect of flavonoid quercetin on human lymphocytic cells; Efeito radioprotetor do flavonóide quercetina sobre células linfocitárias humanas

Energy Technology Data Exchange (ETDEWEB)

Siqueira, Williams N.; Melo, Larissa S.A.; Lima, Maíra V.; Luna Filho, Ricardo L.C.; Melo, Ana M.M.A.; Silva, Edvane B., E-mail: williams.wns@gmail.com, E-mail: larissamelo.pe@gmail.com, E-mail: mairavasconceloslima@gmail.com, E-mail: ricardolclf@hotmail.com, E-mail: amdemelo@hotmail.com, E-mail: edvborges@yahoo.com [Universidade Federal de Pernambuco (UFPE), Recife (Brazil)

2017-07-01

Several substances of synthetic and natural origin have been studied in relation to their ability to protect the body from damage caused by ionizing radiation. Among these substances, quercetin has been shown to be a molecule of natural origin with high radioprotective potential due to its antioxidant properties. The objective of this study was to determine, in vitro, the radioprotective effect of quercetin on human lymphocytes exposed to gamma radiation. Blood was irradiated at the 2.5, 3.5 and 4.5 Gy doses and then lymphocyte culture with quercetin at preselected concentrations of 37.5 and 75 μM. Subsequently, slides were prepared for analysis and quantification of the metaphases present in lymphocyte cells. The results demonstrated that irradiated lymphocytes and later exposed to quercetin presented a lower number of chromosomal alterations compared to the control group which was irradiated and not exposed to quercetin. Therefore, the results suggest a radioprotective effect of flavonoid quercetin on human lymphocytes exposed, in vitro, to ionizing radiation.

Migration patterns of dendritic cells in the rat: comparison of the effects of gamma and UV-B irradiation on the migration of dendritic cells and lymphocytes

Energy Technology Data Exchange (ETDEWEB)

Oluwole, S.F.; Engelstad, K.; De Rosa, C.; Wang, T.S.; Fawwaz, R.A.; Reemtsma, K.; Hardy, M.A. (Columbia Univ., New York, NY (USA))

1991-04-01

To further define the underlying mechanisms of immune suppression induced by UV-B irradiation, we have examined the kinetics of homing patterns of in vitro UV-B-irradiated and gamma-irradiated-thoracic duct lymphocytes (TDL) compared to dendritic cells (DC). Our findings show that {sup 111}In-oxine-labeled TDL specifically home to the spleen, liver, lymph nodes, and bone marrow with subsequent recirculation of a large number of cells from the spleen to lymph nodes. In contrast, DC preferentially migrate to the spleen and liver with a relatively insignificant distribution to lymph nodes and an absence of subsequent recirculation. Splenectomy prior to cell injection significantly diverts the spleen-seeking DC to the liver but not to the lymph nodes, while the homing of TDL to lymph nodes is significantly increased. In vitro exposure of 111In-oxine labeled TDL to gamma irradiation does not significantly impair immediate homing to lymphoid tissues but inhibits cell recirculation between 3 and 24 hr. In contrast, gamma irradiation does not affect the tissue distribution of labeled DC, suggesting that DC are more radioresistant to gamma irradiation than TDL. Unlike the findings in animals injected with gamma-irradiated cells, UV-B irradiation virtually abolished the homing of TDL to lymph nodes and significantly reduced the homing of the spleen-seeking DC to the splenic compartment while a large number of cells were sequestered in the liver. The results of in vitro cell binding assay show that TDL, unlike DC, have the capacity to bind to high endothelial venules (HEV) within lymph node frozen sections while gamma and UV-B irradiation significantly inhibit the binding of TDL to lymph node HEV.

Dose-response relationship for chromosomal aberrations induced in human lymphocytes by 18 MeV electron beam irradiation

International Nuclear Information System (INIS)

Lashin, E.A.; Elaasar, E.M.; Moustafa, H.F.; Bakir, Y.Y.; Al Zenki, S.D.

1990-01-01

Dose response curves for lymphocyte chromosome aberration frequencies using X- and gamma radiation became an important and reliable indicator as biological dosimeter especially in radiation accidents and occupational over exposures. Nowadays electron beam therapy is frequently used for their advantages in cases of tumours under or near to the body surface. Dose-response curves for these electron beams are rarely published. Human peripheral blood lymphocytes were in vitro irradiated with various low and high doses (0.1 Gy to 4.9 Gy) of 18 MeV electron beams to utilize such a dose-response curve using chromosomal aberration frequencies as a biological indicator. Then we compared the biological curve with physically obtained curves normally used in planning for radiotherapy treatment. It is interesting to find a significant difference between both of them. The biological curve is generally higher in value and the aberrations induced by 93% of a dose is significantly higher and deeper in site than those aberrations induced by the 100% dose calculated physically. If the above observation is confirmed by detailed studies, it would be of importance to the radiotherapist to plan for isodose curves according to biological determinations. (author)

Changes in intestinal intraepithelial lymphocytes due to local irradiation of a portion of the maxilla in mice

Energy Technology Data Exchange (ETDEWEB)

Satoh, Daigo; Tamazawa, Ken; Yosue, Takashi; Sakai, Yasuo; Suzuki, Masayuki [Nihon Univ., Tokyo (Japan). School of Dentistry; Arai, Chiaki; Inagaki, Hiroyuki

2000-05-01

We have been investigating the changes of lymphocyte subsets in the immune organs after head and neck irradiation. The present study investigated the influence due to local irradiation (10 Gy) of a portion of the maxilla on intestinal intraepithelial lymphocytes (i-IEL) in mice. We analyzed the percentage of subpopulations in i-IEL following irradiation using two-color fluorometry (anti-TCR{alpha}{beta}, TCR{gamma}{delta}, CD4 and CD8 monoclonal antibodies), and the outcome was compared with that obtained from non-irradiation groups. The result was that the percentage of {alpha}{beta}T cells, {gamma}{delta}T cells, CD4{sup +}SPT cells and CD8{sup +}SPT cells did not show any significant change and the fact differed from that in spleen and thymus where the percentage of these subpopulations was significantly changed. Although spleen and thymus reflect damaged lymphocytes that had circulated through the irradiation field, the result indicates that the balance among i-IEL subsets does not change after irradiation. The reason that equilibrium of i-IEL subsets remains stable seems related to localization of the small intestine and radioresistance. It was also indicated that the effect on the oral epithelium in the irradiation field reflects the percentages of i-IEL subsets. (author)

Protective Effect of Curcumin on γ - radiation Induced Chromosome Aberrations in Human Blood Lymphocytes

International Nuclear Information System (INIS)

AlSuhaibani, E.S

2008-01-01

The present work is aimed at evaluating the radioprotective effect of curcumin on γ radiation induced genetic toxicity. The DNA damage was analyzed by the frequencies of chromosome aberrations assay. Human lymphocytes were treated in vitro with 5.0 γg/ml of curcumin for 30 min at 37 degree C then exposed to 1, 2 and 4 Gy gamma-radiation. The lymphocytes which were pre-treated with curcumin exhibited a significant decrease in the frequency of chromosome aberration at 1 and 2 Gy radiation-induced chromosome damage as compared with the irradiated cells which did not receive the curcumin pretreatment. Thus, pretreatment with curcumin gives protection to lymphocytes against γ-radiation induced chromosome aberration at certain doses. (author)

Comparison of two different techniques on the human lymphocytes morphology and sensitivity to gamma radiation

International Nuclear Information System (INIS)

Kol, R.

1985-02-01

The lymphocytes in the peripheral blood are divided into two main subclasses: T cells and B cells. These differ from each other in function and in their sensitivity to radiation. The effort to study which group is more sensitive to radiation has resulted in many contradictory results. In the present study we examined whether the methods that are used to separate the lymphocytes from the whole blood, before their separation into subclasses, have an effect on the cells and whether this might contribute to the contradictory results. Blood samples were taken from several normal donors and each sample was devided into two fractions. Lymphocytes in each fraction were separated by one of the two following methods: a) sedimentation of erythrocytes by gravitation; b) separation on Ficoll-Paque density gradient. For cells obtained by these two methods, the ultrastructure was examined by electron microscopy and their ability to incorporate radioactive thymidine was measured. Samples separated on Ficoll-Paque showed a subpopulation with morphological changes similar to those occuring in lymphocytes undergoing stimulation. Unstimulated cells separated on Ficoll-Paque showed greater sensitivity to radiation. The effect of gamma radiation on the capability of lymphocytes to undergo transformation in response to three mitogens; PHA, PWM and Con A was examined. Different mitogens stimulate different lymphocytes subpopulations. There was no difference between the two separation methods regarding the sensitivity to gamma radiation of stimulation by PAH and PWM. The transformation by Con A of lymphocytes separated on Ficoll-Paque was more radiosensitive. This could indicate that the separation by Ficoll-Paque density gradient causes a selective depletion of T lymphocytes that react with Con A and are considered more radioresistant. The use of different methods for separating lymphocytes from whole blood- each has a different influence on the cells- can contribute to contradictory

Effect of low-dose irradiation on expression of mRNA and protein. Pt.1. Induction of thioredoxin as radioprotective protein in human lymphocytes

International Nuclear Information System (INIS)

Hoshi, Yuko; Tanooka, Hiroshi; Wakasugi, Hiro; Miyasaki, Kunihisa

1997-01-01

To elucidate the mechanism of hormetic effect by low-dose ionizing radiation, we studied the expression of the thioredoxin (TRX) gene in human lymphocytes after irradiation. TRX is a radioprotector and a key protein regulating cellular functions through redox reaction. The major results obtained were as follows; (1) The peaks of TRX mRNA expression and protein synthesis in human lymphocytes appeared 6-8 hr after irradiation with 25cGy. (2) At 6 hr after irradiation, the optimum dose for induction of TRX mRNA and TRX protein in human lymphocytes appeared to be 25-50cGy. (3) Induction of expression TRX mRNA had individual variations about twice. (4) Lymphocytes prepared from fresh venous blood showed the lowest TRX mRNA level in other cells such a Jurkat cells, lymphocytes stimulated for now with IL-2 and CD3 and the immortalized cell line 1G8. (5) The optimal dose and time course of induction of TRX by low-dose radiation suggest that TRX is related to the radio-adaptive response. (author)

Inactivation of HTB63 human melanoma cells by irradiation with protons and gamma rays.

Science.gov (United States)

Ristic-Fira, Aleksandra; Petrovic, Ivan; Todorovic, Danijela; Koricanac, Lela; Vujèic, Miroslava; Demajo, Miroslav; Sabini, Gabriella; Cirrone, Pablo; Cuttone, Giacomo

2004-12-01

The effects of single irradiation with gamma rays and protons on HTB63 human melanoma cell growth were compared. The exponentially growing cells were irradiated with gamma rays or protons using doses ranging from 2-20 Gy. At 48 h of post-irradiation incubation under standard conditions, cell survival and induction of apoptotic cell death were examined. The best effect of the single irradiation with gamma rays was the reduction of cell growth by up to 26% (p=0.048, irradiation vs. control), obtained using the dose of 16 Gy. The same doses of proton irradiation, having energy at the target of 22.6 MeV, significantly inhibited melanoma cell growth. Doses of 12 and 16 Gy of protons provoked growth inhibition of 48.9% (p=0.003, irradiation vs. control) and 51.2% (p=0.012, irradiation vs. control) respectively. Irradiation with 12 and 16 Gy protons, compared to the effects of the same doses of gamma rays, significantly reduced melanoma cell growth (p=0.015 and p=0.028, protons vs. gamma rays, respectively). Estimated RBEs for growth inhibition of HTB63 cells ranged from 1.02 to 1.45. The electrophoretical analyses of DNA samples and flow cytometric evaluation have shown a low percentage of apoptotic cells after both types of irradiation. The better inhibitory effect achieved by protons in contrast to gamma rays, can be explained considering specific physical properties of protons, especially taking into account the highly localized energy deposition (high LET).

The relationship between lymphocytes activated by pokeweed mitogen and by lipopolysaccharides and their radiosensitivity

International Nuclear Information System (INIS)

Su Liaoyuan; Liu Fenju; Liu Keliang; Xu Changshao; Xu Yingdong; Geng Yongzhi

1992-07-01

Human whole blood was incubated in vitro. Lymphocytes were activated by poke-weed mitogen (PWM) and by Lipopolysaccharides (LPS). The relationship between the two kinds of lymphocytes was investigated using radioactive compound incorporation. The study showed that PWM-activated lymphocytes were able to promote the stimulating effect of LPS on B lymphocytes. The stimulating effect of PWM-activated lymphocytes was obviously decreased after they were irradiated with 10 Gy gamma rays. When PWM-activated lymphocytes and LPS-activated lymphocytes were incubated together after one of the cell populations had been exposed 10 Gy 60 Co gamma rays, the incorporation of [ 3 H] TdR was much decreased and the synergistic function disappeared, especially when the PWM-activated lymphocytes were irradiated. In cells from patients treated with 60 Co gamma rays for carcinoma of nasopharynx, the incorporation in LPS-activated lymphocytes approached normal levels while that in PWM-activated lymphocytes was reduced significantly and the stimulating effect of PWM-activated lymphocytes on LPS-activated lymphocytes was also markedly reduced. These demonstrate that PWM-activated lymphocytes have a similar function to T-helper cells and seem to be more radiosensitive than LPS-activated lymphocytes

Survival of human lymphocytes after exposure to densely ionizing radiations

International Nuclear Information System (INIS)

Madhvanath, U.; Raju, M.R.; Kelly, L.S.

1976-01-01

Interphase death of human blood lymphocytes cultured in vitro was studied after exposure to 60 Co gamma rays and to accelerated ions of 1 H, 4 He, 7 Li, 11 B, 12 C, 20 Ne, 40 Ar, and π - meson beam under aerobic conditions. Exposures were also conducted under hypoxic conditions with 60 Co gamma rays, 4 He, 7 Li, and 12 C ion beams. Time course of interphase death was followed for 6 days after irradiation. Percent survivals were determined by using the trypan blue exclusion method. Survival curves at 5 days postirradiation were exponential for all radiations studied. These observations indicate that the production of interphase death of lymphocytes by densely ionizing radiations follows a pattern similar to that observed with colony-forming mammalian cells. However, the reproductive capacity of the latter cells is impaired with maximum effectiveness at energy densities associated with 220 keV/μm for the beam conditions used in this investigation. The much lower energy densities required to kill a lymphocyte suggest that a sensitive structure other than DNA may be responsible for the production of lymphocyte death, perhaps the membranes. The calculated inactivation cross sections for high-LET radiations above 650 keV/μm yielded values larger than the actual cell dimensions. It appears that contributions from delta rays become appreciable in this system at these LET's

In vivo induction of apoptosis in human lymphocytes by therapeutic fractionated total body irradiation

International Nuclear Information System (INIS)

Delic, J.; Magdelenat, H.; Barbaroux, C.; Chaillet, M.-P.; Dubray, B.; Fourquet, A.; Cosset, J.-M.; Gluckman, E.; Girinsky, T.

1995-01-01

Ionizing radiations have been reported as an in vitro apoptosis initiating stimulus in human lymphocytes. As the cytotoxicity of ionizing radiations and chemotherapeutic agents appears to be dependent on the efficacy of cell death induction, the manipulation of apoptosis initiation might be used as a means to suppress some pathological process. In the present study the in vivo induction of γ-ray mediated programmed cell death in humans is reported. The in vivo induction of apoptosis in peripheral blood lymphocytes (PBL) by ionizing radiations was investigated in 33 patients after each of two sessions (2 Gy and 4 Gy) of fractionated total body irradiation (FTBI) as part of their conditioning regimen before bone marrow transplantation. PBL committed to apoptosis were scored before irradiation (S1), 4 h (S2) and 24 h after 2 Gy (S3, 14-17 h after the second 2 Gy fraction). Nuclear morphology and chromatin-DNA were analysed by fluorescence microscopy immediately after blood sample withdrawal (I) and after 24 h in cell culture medium (II). (author)

Localization of specific sequences and DNA single-strand breaks in individual UV-A-irradiated human lymphocytes by COMET FISH

Science.gov (United States)

Bock, Claudia; Rapp, Alexander; Dittmar, Heike; Monajembashi, Shamci; Greulich, Karl-Otto

1999-01-01

The COMET assay, a single cell electrophoresis technique which allows to separate electrophoretically fractionated DNA according to size has been combined with fluorescence in situ hybridization (FISH) which allows to localize specific genes or gene regions. This combination (COMET FISH) allows the detection of DNA single strand breaks in specific regions of the genome of human lymphocytes at the single cell level. Various types of DNA probes, e.g. centromere-, (alpha) - satellite-, telomere-, whole chromosome-, single copy- and region specific DNA probes have been used to investigate whether the UV-A induced DNA single strand breaks are distributed randomly all over the human genome or induced at specific sites ('hot spots'). In the investigated human peripheral blood lymphocytes all but one centromere reveal low sensitivity for UV-A irradiation (500 kJ/m2), while telomeres are randomly distributed over COMET heads and tails. The human chromosome 1 is fractionated by irradiation, but remains in the COMET head, indicating an only moderate degree of fractionation. Among three tested single copy probes, c- myc, p53 and p58, the p53 gene located on chromosome 17p13.1 and the p58 gene (1p36) appear to be located in UV-A stable regions of the human genome in 95% of 65 investigated lymphocytes. In contrast, the c-myc proto-oncogene (8q24) is found in the COMET tail in 90% of the 27 investigated lymphocytes and thus appears to be more sensitive to UV-A irradiation.

Effect of Green Tea Extract on T cell Mediated Hypersensitivity Reaction in BALB/c Mice Exposed to Gamma Irradiation

International Nuclear Information System (INIS)

Hashim, A.M.; Ismail Al-kadey, M.M.I.; Shabon, M.H.; Hussien, S.M.

2010-01-01

Gamma radiation is widely used in the treatment of malignant neoplasms. However, it deprives the host immune function which may retard tumor rejection by the immune response. The main purpose of the present study is to test the ability of green tea dry extract to restore the T cell hypersensitivity reaction in gamma irradiated BALB/c mice. It aims also to elucidate the possible mechanism of action of ionizing radiation and green tea dry extract in the immune function. Four groups of BALB/c mice, each of ten, have been used in each experiment. The first group served as a control, the second group received green tea dry extract and the third group was exposed to 2 Gy gamma irradiation, while the fourth group received green tea dry extract before and after gamma irradiation. The following parameters were determined, the contact sensitivity reaction by the mouse ear swelling response, local dendritic cell migration, local lymph node weight, lymphocyte proliferation, spleen and thymus weight with their lymphocyte count. The effect of gamma irradiation and green tea dry extract on the elicitation phase of contact sensitivity was also determined. Data from the present study showed that gamma irradiation caused a significant decrease of the mouse ear swelling response and retarded dendritic cell migration. They also showed a significant decline in the lymphocytes proliferation in lymph node draining the contact sensitizer application. Total body exposure to 2 Gy gamma irradiation induced marked decline of thymus weight and thymocyte count, while it reduced spleen weight and spleenocyte count to a lesser extent. Exposure to gamma irradiation enhanced the elicitation phase of contact sensitivity. Administration of green tea dry extract partially preserved the contact sensitivity response to oxazolone in gamma irradiated BALB/c mice. It markedly minimized the enhancement of the elicitation phase of ear swelling. In conclusion, the present study heralds a beneficial role of

Analysis of the frequency of unstable chromosome aberrations in human lymphocytes irradiated with 60Co

International Nuclear Information System (INIS)

Mendonca, Julyanne C.G.; Mendes, Mariana E.; Lima, Fabiana F.; Santos, Neide

2013-01-01

The aim of this study was to analyze the frequency of unstable chromosomal aberrations induced by gamma radiation from a 60 Co source at two different doses. Samples were obtained from a healthy donor and exposed to 60 Co source (Gammacel 220 ) located in the Department of Nuclear Energy of Pernambuco Federal University (DEN/UFPe/Brazil) with a rate of air Kerma to 3,277 Gy/h. Exposures resulted in absorbed dose 0.51 Gy and 0.77 Gy. Mitotic metaphases were obtained by culturing lymphocytes for chromosome analysis and the slides were stained with 5% Giemsa. Among the unstable chromosomal aberrations the dicentric chromosomes, ring chromosomes and acentric fragments were analyzed. To calculate the significance level the chi - square test was used, considering relevant differences between the frequencies when the value of p < 0.05. To calculate the significance level of the chi - square test was used, considering relevant differences between the frequencies when the value of p < 0.05. The results showed that there was significant difference of the frequencies of dicentric chromosomes (from 0.18 to 0.51 to 0.37 Gy to 0.77 Gy), however there was no statistically significant difference between the frequencies of acentric fragments ( 0.054 to 0, 51 Gy to 0.063 to 0.77 Gy) and ring chromosomes (0.001 to 0.51 Gy to 0.003 to 0.77 Gy). The low number of rings is found justified, considering that in irradiated human lymphocytes, its appearance is rare relative to dicentrics. The results confirm that dicentrics are the most reliable biomarkers in estimating dose after exposure to gamma radiation. These two points will make the calibration curve dose-response being built for Biological Dosimetry Laboratory of CRCN-NE/CNEN

Short-term effects of regional irradiation on lymphocytes, T lymphocytes and eosinophils

International Nuclear Information System (INIS)

Chazarin, C.; Roche, H.; Bugat, R.; Pris, F.

1983-01-01

Twenty-three cancer patients treated only by regional irradiation were studied. Radiotherapy was delivered to the pelvis in 14 patients and to the mediastinum in 9. T lymphocytes were evaluated with the Jondal technique. Before treatment, lymphocyte counts were identical in patients and control. Decreases in total lymphocytes and T lymphocytes became significant in both groups after 40 Gy. Significant rises in eosinophil counts were found only after abdominal irradiation and seemed unrelated to variations in lymphocyte counts [fr

Chromosome aberrations in human peripheral lymphocytes induced by single or fractionated X-irradiation

International Nuclear Information System (INIS)

Ivanov, B.; Leonard, A.; Deknyudt, G.

1980-01-01

Investigated is the effect of single (125 and 250 R) and fractionated (2x125 R) irradiation on the output of chromosome aberrations in lymphocytes of human peripheral blood kept between irradiations at the temperature of 5 deg C. The single irradiation is carried out immediately after vein-puncture. In the case of fractionated irradiation the first dose of 125R is given after vein-puncture, the second, in the interval of 2, 8 and 24 hours. Blood is cultivated immediately after two irradiations in order to prepare metaphase plates for cytogenic analysis. Repair processes in cell heritage structures are not realised in blood irradiated by fractions which is kept at 5 deg C between irradiations. On the contrary, chromosome fragments, interstitial deletions, aberrant cells and cell breaks are found in a large amount in blood irradiated by fractions. They have appeared with the authentically high statistic difference as compared with the cells irradiated one time with the same dose. This effect is probably attained due to blood preservation

Radiation sensitivity of human malignant lymphocytes

International Nuclear Information System (INIS)

Seshadri, R.; Matthews, C.; Morley, A.A.

1985-01-01

A simple and rapid in vitro technique to assess the sensitivity of human malignant lymphocytes to roentgen irradiation is described. A variety of established malignant lymphocyte cell lines were cloned in microwells and clone survival was used as the end-point. The survival of the clonogenic malignant lymphocyte down to a fraction of approximately 0.001 could be measured accurately. Except for a T-cell line, the radiation sensitivities of the cell lines were similar to that of normal T-lymphocytes. (orig.)

Activation of immune functions via induction of glutathione of lymphocytes by low-dose, whole-body irradiation with gamma-rays

International Nuclear Information System (INIS)

Shuji Kojima; Hisatake Hayase; Mareyuki Takahashi

2007-01-01

Complete text of publication follows. We have recently found that low doses of radiation, unlike higher doses, do not always cause a decrease of cellular glutathione, but they can increase it, leading to an elevation of Con A-induced proliferation of splenocytes. In this study, we first examined whether the increase of glutathione level induced by low-dose gamma-ray irradiation is involved in the appearance of enhanced natural killer (NK) activity and antibody-dependent cellular cytotoxicity (ADCC), leading to delayed tumor growth in Ehrlich solid tumor (EST)-bearing mice. NK activity in ICR mouse splenocytes was significantly increased from 4 h to 6 h after a single whole-body gamma-ray irradiation at 0.5 Gy, and thereafter decreased almost to the zero-time level by 24 h post-irradiation. ADCC was also increased significantly in a similar way. Reduced glutathione exogenously added to splenocytes obtained from normal mice enhanced both NK activity and ADCC in a dose-dependent manner. The inhibitory effect of the radiation on tumor growth was then examined in EST-bearing mice. Repeated low-dose irradiation (0.5 Gy, four times, before and within an early time after the inoculation) significantly delayed the tumor growth. Finally, the effect of single low-dose (0.5 Gy), whole-body gamma-ray irradiation on immune balance (Th1/Th2) was examined in order to elucidate the mechanism underlying the anti-tumor immunity. Recent studies indicate that Th1/Th2 balance plays an important role in the immune responses involved in anti-tumor immunity. The activity of NK is hallmarks of cell-mediated immunity, and play key roles in anti-tumor immunity. The percentage of B cells in blood lymphocytes was selectively decreased after the radiation, concomitantly with an increase in that of helper T cell population, favoring Th1 polarization. The IFN-gamma level in splenocyte culture prepared from EST-bearing mice was significantly increased 48 h after the radiation, though the level of

Survival and PHA-stimulation of #betta#-irradiated human peripheral blood T lymphocyte subpopulations

International Nuclear Information System (INIS)

Schwartz, J.L.; Darr, D.C.; Daulden, M.E.

1983-01-01

Human peripheral blood T lymphocyte subpopulations were identified and isolated on the basis of their ability to bind IgG (T-G), IgM (T-M), or neither immunoglobulin class (T-null). Lymphocytes were exposed to 0, 0.5, 1.0, 2.5 or 5.0 Gy of 60 Co #betta#-rays either as a T-cell suspension or as separated T cell subsets. Survival curves, determined 5 days after irradiation, revealed that each subset has radiosensitive and radioresistant portions, and that the T-G cell is the most sensitive subset. Mitotic indices of 48-h cultures showed that the response of unirradiated T lymphocytes to PHA varied greatly among the subsets, the highest indices being obtained for the T-M and the lowest for the T-G cells. With the possible exception of the T-G cells, the subsets are realtively resistant to mitotic effects of #betta#-rays. T-G cells suppress the PHA-induced mitotic response of the other T lymphocyte subsets, and this suppressor effect is radiosensitive, being abolished by 1.0 Gy. It is concluded that lymphocytes exposed to >= 1 Gy of #betta#-rays will have very few dividing B lymphocytes or T-G cells. This together with radiation-induced loss of T-G suppressor action means that the predominant lymphocyte types in mitosis after >=1 Gy are the radioresistant T-M and T-null cells. (orig.)

Effect of radiation therapy on the mitogenic response of in vitro irradiated human lymphocytes to phytohaemagglutinin

International Nuclear Information System (INIS)

Baral, E.; Blomgren, H.; Einhorn, N.; Lax, I.; Juhlin, I.

1977-01-01

Irradiation of human peripheral lymphocytes in vitro reduces their capacity to be triggered to DNA-synthesis by PHA in a two-dose shaped fashion suggesting the presence of one relatively radiationsensitive and one relatively resistant cell population. Intracavitary and external radiation therapy for carcinoma of the uterus and vagina, which reduced the lymphocyte counts by approximately 66 per cent, did not significantly change the ratio of these subpopulations, indicating that PHA-reactive cells cannot be grouped into radiation sensitive and resistant subpopulations

Dose-response calibration curves of {sup 137}Cs gamma rays for dicentric chromosome aberrations in human lymphocytes

Energy Technology Data Exchange (ETDEWEB)

Jo, Wol Soon; Oh, Su Jung; Jeong, Soo Kyun; Yang, Kwang Mo [Dept. of Research center, Dong Nam Institute of Radiological and Medical Sciences, Busan (Korea, Republic of); Jeong, Min Ho [Dept. of Microbiology, Dong A University College of Medicine, Busan (Korea, Republic of)

2012-11-15

Recently, the increased threat of radiologically industrial accident such as radiation nondestructive inspection or destruction of nuclear accident by natural disaster such as Fukushima accident requires a greater capacity for cytogenetic biodosimetry, which is critical for clinical triage of potentially thousands of radiation-exposed individuals. Dicentric chromosome aberration analysis is the conventional means of assessing radiation exposure. Dose–response calibration curves for {sup 13}'7Cs gamma rays have been established for unstable chromosome aberrations in human peripheral blood lymphocytes in many laboratories of international biodosimetry network. In this study, therefore, we established dose– response calibration curves of our laboratory for {sup 137}Cs gamma raysaccording to the IAEA protocols for conducting the dicentric chromosome assay We established in vitro dose–response calibration curves for dicentric chromosome aberrations in human lymphocytes for{sup 13}'7Cs gamma rays in the 0 to 5 Gy range, using the maximum likelihood linear-quadratic model, Y = c+αD+βD2. The estimated coefficients of the fitted curves were within the 95% confidence intervals (CIs) and the curve fitting of dose–effect relationship data indicated a good fit to the linear-quadratic model. Hence, meaningful dose estimation from unknown sample can be determined accurately by using our laboratory’s calibration curve according to standard protocol.

Invitro genotoxicity, assessment of cytotoxicity and of Rely X luting cement on human lymphocyte cells before and after irradiation

International Nuclear Information System (INIS)

Shetty, Shilpa S.; Hegde, Mithra N.; Shabin; Hegde, Nidarsh D.; Suchetha Kumari; Sanjeev, Ganesh

2013-01-01

In dentistry, a luting agent is a viscous material placed between tooth structure and a prosthesis that by polymerization firmly attach the prosthesis to the tooth structure. Luting agents contact a large area of dentin when used for crown cementation. There is little information on biocompatibility tests, especially on the effect of electron beam irradiation on cytotoxicity for luting resin cements. To determine the in vitro cytotoxicity and genotoxicity of Rely X luting cement on human lymphocyte cells before and after irradiation. Rely X luting cement was obtained commercially. Samples were prepared as per the ISO standard size of 25x2x2 mm using polytetrafluoroethylene teflon mould and divided into two groups - non irradiated and irradiated groups. The samples in irradiated category were exposed to 200 Gy of electron beam irradiation at Microtron Centre, Mangalore University, Mangalore, India. For hemolysis the samples were immersed in phosphate buffer saline and incubated at 370℃ for 24 hrs, 7 days and 14 days. 200 μl of 24 hr material extract was mixed with human peripheral blood lymphocyte tested for comet assay by single cell DNA comet assay. Hemolytic activity of non irradiated Rely X luting cement after 24 hrs, 7 days and 14 days was 54.78±1.48, 69.91±2.41 and 43.21±0.92 respectively whereas hemolytic activity of irradiated Rely X luting cement after 24 hrs, 7 days and 14 days was 91.8±8.29, 56.95±19.7 and 41.34±12.30. The irradiation of Rely X luting cement with 200 Gy dose of electron beam irradiation caused an increase in the frequency of DNA damage when compared to that of the non-irradiated group. Based on the experimental condition, it is concluded that incomplete polymerization of the dental luting cements has resulted in the elution of the resin components which are responsible for the cytotoxicity and genotoxicity of Rely X luting cement on human lymphocyte cells. (author)

Solar-simulated ultraviolet irradiation induces selective influx of CD4+ T lymphocytes in normal human skin

NARCIS (Netherlands)

Di Nuzzo, S.; de Rie, M. A.; van der Loos, C. M.; Bos, J. D.; Teunissen, M. B.

1996-01-01

The proportion and composition of the human cutaneous CD3+ T lymphocyte population was determined in situ following a single exposure to physiological, erythema-inducing doses of simulated solar radiation, mainly consisting of UV radiation. Biopsies were taken 1, 2 and 7 days after local irradiation

T gamma/delta lymphocytes in renal transplant recipients

NARCIS (Netherlands)

Raasveld, M. H.; Bloemena, E.; Surachno, S.; ten Berge, R. J.

1992-01-01

T gamma/delta lymphocytes are able to perform allospecific cytotoxicity and natural killer cytotoxicity in vitro. However, very little is known about their function in vivo. To investigate the possible involvement of T gamma/delta lymphocytes in the immune response to renal allografts, fine-needle

The growth of human fibroblasts and A431 epidermoid carcinoma cells on gamma-irradiated human amnion collagen substrata.

Science.gov (United States)

Liu, B; Harrell, R; Lamb, D J; Dresden, M H; Spira, M

1989-10-15

Human fibroblasts and A431 human epidermoid carcinoma cells were cultured on gamma-irradiated human amnion collagen as well as on plastic dishes and non-irradiated collagen coated dishes. The morphology, attachment, growth and short-term cytotoxicity of these culture conditions have been determined. Both irradiated and non-irradiated amnion collagen enhanced the attachment and proliferation of fibroblasts as compared to the plastic dishes. No differences in these properties were observed for A431 cells cultured on irradiated collagen when compared with culture on non-irradiated collagen substrates. Cytotoxicity assays showed that irradiated and non-irradiated collagens were not cytotoxic for either fibroblasts or A431 cells. The results demonstrated that amnion collagen irradiated at doses of 0.25-2.0 Mrads is optimal for cell growth.

The use of gamma-irradiation and ultraviolet-irradiation in the preparation of human melanoma cells for use in autologous whole-cell vaccines

International Nuclear Information System (INIS)

Deacon, Donna H; Slingluff, Craig L Jr; Hogan, Kevin T; Swanson, Erin M; Chianese-Bullock, Kimberly A; Denlinger, Chadrick E; Czarkowski, Andrea R; Schrecengost, Randy S; Patterson, James W; Teague, Mark W

2008-01-01

Human cancer vaccines incorporating autologous tumor cells carry a risk of implantation and subsequent metastasis of viable tumor cells into the patient who is being treated. Despite the fact that the melanoma cell preparations used in a recent vaccine trial (Mel37) were gamma-irradiated (200 Gy), approximately 25% of the preparations failed quality control release criteria which required that the irradiated cells incorporate 3 H-thymidine at no more than 5% the level seen in the non-irradiated cells. We have, therefore, investigated ultraviolet (UV)-irradiation as a possible adjunct to, or replacement for gamma-irradiation. Melanoma cells were gamma- and/or UV-irradiated. 3 H-thymidine uptake was used to assess proliferation of the treated and untreated cells. Caspase-3 activity and DNA fragmentation were measured as indicators of apoptosis. Immunohistochemistry and Western blot analysis was used to assess antigen expression. UV-irradiation, either alone or in combination with gamma-irradiation, proved to be extremely effective in controlling the proliferation of melanoma cells. In contrast to gamma-irradiation, UV-irradiation was also capable of inducing significant levels of apoptosis. UV-irradiation, but not gamma-irradiation, was associated with the loss of tyrosinase expression. Neither form of radiation affected the expression of gp100, MART-1/MelanA, or S100. These results indicate that UV-irradiation may increase the safety of autologous melanoma vaccines, although it may do so at the expense of altering the antigenic profile of the irradiated tumor cells

Effect of IL-2 on recovery of proliferation ability of irradiated T lymphocytes

International Nuclear Information System (INIS)

Wang Ninghai; Zhang Lansheng

1989-01-01

3 H-thymidine incorporation assay was used to evaluated the proliferation ability of normal human peripheral blood T lymphocytes irradiated with or without exogenous IL-2 by 60 Co γ-ray at various doses after exposure to 1, 2.5, 5, 10, 20 and 40 Gy γ-ray, the DNA synthesis is blocked. It indicated IL-2 has damage effect on the proliferation ability of T cells. 3 H-thymidine incorporation rate in cells decreases with increasing dose of irradiation. Incorporation of 3 H-Tdk in irradiated groups in the dose range of 1 to 40 Gy was compared with that in the control group. The incorporation rate 3 H-TdR in these irradiated groups is 27 to 82 % of that in control group. The inhibition of lymphocyte proliferation was partially enhanced by adding IL-2, but the inhibiting effect on proliferation of human peripheral blood lymphocytes exposed to irradiation at more than 10 Gy is not reversible

Damage of lymphocytes by ionizing irradiation

International Nuclear Information System (INIS)

Rose, H.; Moldenhauer, H.; Kehrberg, G.

1985-01-01

After a short review, how lymphocytes of the peripheral blood are influenced by radiotherapy, the damage of lymphocytes by whole-body irradiation is pointed out in animal experiments and after in vitro irradiation. The special sensibility of B-cells and their homogeneity in fields of radiobiology are opposed to the heterogeneity of T-cells. The radiosensibility of cytotoxic lymphocytes, suppressor cells, and helper cells are discussed. It appears, that within these functional criteria, there is a different radiosensibility, too. (author)

The dependence of the magnitude of induced adaptive responseon on the dose of pre-irradiation of cultured human lymphocytes under the optimum irradiation time scheme

International Nuclear Information System (INIS)

Mortazavi, S.M.J.; Mozdarani, H.

2000-01-01

Human lymphocytes exposed to low doses of X-rays, become less susceptible to the induction of chromosome aberrations by subsequent exposure to high doses of X-rays. This has been termed the radioadaptive response. One of the most important questions in the adaptive response studies was that of the possible existence of an optimum adapting dose. Early experiments indicated that this response could be induced by low doses of X-rays from 1 cGy to 20 cGy. Recently, it has been interestingly shown that the time scheme of exposure to adapting and challenge doses plays an important role in determination of the magnitude of the induced adaptive response. In this study, using the optimum irradiation time scheme (24-48), we have monitored the cytogenetic endpoint of chromosome aberrations to assess the magnitude of adaptation to ionizing radiation in the cultured human lymphocytes. Lymphocytes were pre-exposed to an adapting dose of 1-20 cGy at 24 hours, before an acute challenge dose of 1 or 2 Gy at 48 hours. Cells were fixed at 54 hours. Lymphocytes, which were pretreated with 5 as well as 10 cGy adapting doses, had significantly fewer chromosome aberrations. In spite of the fact that lymphocytes of some of our blood donors which were pre-treated with 1 or 20 cGy adapting doses, showed an adaptive response, the pooled data (all donors) indicated that such an induction of adaptive response can not be observed in these lymphocytes. The overall pattern of the induced adaptive response, indicated that in human lymphocyte (at least under the above mentioned irradiation scheme), 5 cGy and 10 cGy adapting doses are the optimum doses. (author)

Autoradiographic study of gamma-irradiated mouse spleen during primary immune response

International Nuclear Information System (INIS)

Gitsov, L.G.; Kyncheva, L.S.; Burneva, V.G.; Martinova, J.Sh.; Viklichka, S.

1978-01-01

Study on the kinetics of the cells in the mouse spleen during the primary immune response against thymusdependent antigen after sublethal irradiation was carried out. For this purpose the animals were immunized with sheep erythrocytes one day after their irradiation with 700 r gamma rays. On the 5th day after the immunization, tritium labelled thymidine was injected three times at two hourly intervals. Mice were killed two hours after the third injection for preparation of routine histological samples and autoradiographs. Immunized, but not irradiated mice were utilized as controls. Extensive zones of lymphocyte destruction were observed in the spleen of the irradiated mice - accumulation of picnotic lymphocyte nuclei, surrounded by reticulo-histocyte elements. The number of the labelled cells and the intensity of labelled are lower than that of the germinal centres in control animal. There is no marked cell destruction in the periarteriolar zone nor labelled cells, whereas in the controls there is a considerable number of labelled blast cells. In the red pulp of the irradiated animals islands of erythroblasts were found, whereas in the controls - parallely to the erythroblast islands, there are islands of proliferating lymphocytes and plasmocytes. The decrease of lymphocyte number in irradiated mice is connected with their destruction and with the altered lymphocytopoiesis in the red pulp. It is assumed that the observed preservation of the periarteriolar lymphatic sheaths in an expression of a higher radioresistance of the T-cells as compared to the B-cells in the white pulp. This study contributes for elucidation of the irradiation immunosuppressive effect. It points out also that the post-irradiation lymphopaenia is due not only to the cell death but also to the exclusion of part of the T-lymphocytes from the circulation and their selective deposition in the thymus-dependent zones of the peripheral lymphoid organs. (A.B.)

Clastogenic effects in human lymphocytes exposed to low and high dose rate X-ray irradiation and vitamin C

International Nuclear Information System (INIS)

Konopacka, M; Rogolinski, J.

2011-01-01

In the present work we investigated the ability of vitamin C to modulate clastogenic effects induced in cultured human lymphocytes by X-irradiation delivered at either high (1 Gy/min) or low dose rate (0.24 Gy/min). Biological effects of the irradiation were estimated by cytokinesis-block micronucleus assay including the analysis of the frequency of micronuclei (MN) and apoptotic cells as well as calculation of nuclear division index (NDI). The numbers of micronucleated binucleate lymphocytes (MN-CBL) were 24.85 ± 2.67% and 32.56 ± 3.17% in cultures exposed to X-rays (2 Gy) delivered at low and high dose rates, respectively. Addition of vitamin C (1-20 μg/ml) to the medium of cultures irradiated with the low dose rate reduced the frequency of micronucleated lymphocytes with multiple MN in a concentration-dependent manner. Lymphocytes exposed to the high dose rate radiation showed a U-shape response: low concentration of vitamin C significantly reduced the number of MN, whereas high concentration influenced the radiation-induced total number of micronucleated cells insignificantly, although it increased the number of cells with multiple MN. Addition of vitamin C significantly reduced the fraction of apoptotic cells, irrespective of the X-ray dose rate. These results indicate that radiation dose rate is an important exposure factor, not only in terms of biological cell response to irradiation, but also with respect to the modulating effects of antioxidants. (authors)

Familial study of ataxia telangiectasia. Heterozygotes identification on the basis of sensitivity of gamma-irradiated cultures to caffeine post-treatment

Energy Technology Data Exchange (ETDEWEB)

Pawlak, A.L.; Kotecki, M. [Polska Akademia Nauk, Poznan (Poland). Zaklad Genetyki Czlowieka; Ignatowicz, R. [Centrum Zdrowia Dziecka, Warsaw (Poland)

1994-12-31

The effects of caffeine (CF), {gamma}-irradiation + CF post-treatment on chromosomal aberrations were studied in lymphocyte cultures from a patient with ataxia telangiectasia (AT), his parents and brother. In the studied family both the homozygotes and the obligatory heterozygotes of AT showed increased sensitivity to CF post-treatment. Individual differences in sensitivity to {gamma}-irradiation + CF post-treatment proved to be correlated with the sensitivity of non-irradiated cells to CF treatment, but not to {gamma}-irradiation. (author). 19 refs, 1 fig., 1 tab.

Differential effect of gamma-irradiated and heat-treated lymphocytes on T cell activation, and interleukin-2 and interleukin-3 release in the human mixed lymphocyte reaction

International Nuclear Information System (INIS)

Loertscher, R.; Abbud-Filho, M.; Leichtman, A.B.; Ythier, A.A.; Williams, J.M.; Carpenter, C.B.; Strom, T.B.

1987-01-01

Heat-inactivated (45 degrees C/1 hr) lymphocytes selectively activate suppressor T cells in the mixed lymphocyte reaction (MLR), while no significant proliferation and cytotoxic T lymphocyte activation can be detected. It is not well understood why hyperthermic treatment abolishes the stimulatory capacity of lymphocytes since HLA-DR molecules remain detectable immediately following heat exposure. In order to further characterize the requirements for Ts activation we studied the effects of hyperthermic treatment on cellular protein and DNA synthesis and cell surface protein expression in proliferating T and B cells; interleukin (IL)-1, IL-2, and IL-3 release following allogeneic stimulation with heat treated cells (HMLR); and IL-2 receptor expression as an indicator of T cell activation in the HMLR. Hyperthermic treatment reduced cellular protein synthesis as estimated by 14 C-leucine uptake to about 15%, and DNA synthesis ( 3 H-thymidine incorporation) to about 5% of untreated control cells. In contrast to y-irradiated cells, viability of heated cells rapidly declined within the first 24 hr. Hyperthermic treatment doubled binding of mouse immunoglobulin paralleled by an increased expression of IL-2 and transferrin receptors, while expression of HLA-DR and 4F2 proteins appeared unchanged. Stimulation with heated cells triggered the release of IL-1- and an IL-3-like bioactivity but did not induce IL-2 synthesis and/or release, thus explaining the lack of proliferation in the HMLR. Addition of exogenous IL-2 but not IL-1 restored HMLR proliferation. A comparison of allostimulation with y-irradiated and heat-treated cells revealed that significantly fewer T cells were induced to express IL-2 receptors at day 3 (14% vs. 8%, P less than 0.001) and at day 6 (42% vs. 21%, P less than 0.05) with heat-inactivated stimulators

Gelam Honey Protects against Gamma-Irradiation Damage to Antioxidant Enzymes in Human Diploid Fibroblasts

Directory of Open Access Journals (Sweden)

Suzana Makpol

2013-02-01

Full Text Available The present study was designed to determine the radioprotective effects of Malaysian Gelam honey on gene expression and enzyme activity of superoxide dismutase (SOD, catalase (CAT and glutathione peroxidase (GPx of human diploid fibroblasts (HDFs subjected to gamma-irradiation. Six groups of HDFs were studied: untreated control, irradiated HDFs, Gelam honey-treated HDFs and HDF treated with Gelam honey pre-, during- and post-irradiation. HDFs were treated with 6 mg/mL of sterilized Gelam honey (w/v for 24 h and exposed to 1 Gray (Gy of gamma rays at the dose rate of 0.25 Gy/min. Gamma-irradiation was shown to down-regulate SOD1, SOD2, CAT and GPx1 gene expressions (p < 0.05. Conversely, HDFs treated with Gelam honey alone showed up-regulation of all genes studied. Similarly, SOD, CAT and GPx enzyme activities in HDFs decreased with gamma-irradiation and increased when cells were treated with Gelam honey (p < 0.05. Furthermore, of the three different stages of study treatment, pre-treatment with Gelam honey caused up-regulation of SOD1, SOD2 and CAT genes expression and increased the activity of SOD and CAT. As a conclusion, Gelam honey modulates the expression of antioxidant enzymes at gene and protein levels in irradiated HDFs indicating its potential as a radioprotectant agent.

Effects of Hesperidin as a Radioprotector on Apoptosis in Rat Peripheral Blood Lymphocytes after Gamma Radiation

Directory of Open Access Journals (Sweden)

Fardid R.

2016-12-01

Full Text Available Introduction: Hesperidin (HES, as the most abundant flavonoid existing in the citrus, is widely used by human daily. The radio-protective effects of Hesperidin have been confirmed in various measurement systems. This study aimed to evaluate the effects of Hesperidin on the changes in the apoptosis level and expression of apoptotic genes target (bax, bcl-2 and ration of bax/bcl-2 in the peripheral blood lymphocytes of male rats after gamma radiation. Materials and Methods: 64 male rats were divided into eight groups: Control, HES (100 mg/kg b.w, orally, 7 days, whole body irradiation with 2 and 8Gy, preadministrated with 50 and 100 mg/kg body weight of Hesperidin for 7 days before irradiation with 2 and 8 Gy. 24 hours after radiation, apoptotic lymphocytes were evaluated using PE Annexin V Apoptosis detection I kit and the levels of mRNA for bax and bcl-2 were evaluated by real time reverse transcription polymerase chain reaction. Results: A significant reduction in apoptosis of the lymphocytes was demonstrated in group animals receiving 8 Gy compared to the group which received 2 Gy irradiation (p<0.0001. However, apoptosis significantly increased in group of rats who received Hesp before irradiation (p<0.05. The increase of apoptosis by Hesperidin administration can be attributed to the decreased expression of bax and significantly reduced expression of bcl-2 and finally increasing the ration of bax/bcl-2. Conclusion: The results suggest that administration of 50 and 100 mg/kg of Hesperidin induces apoptotic effects by changing expression level of bax, bcl-2 and also the ratio of bax/bcl2.

Radiolabeled Humanized Anti-CD3 Monoclonal Antibody Visilizumab for Imaging Human T-Lymphocytes

NARCIS (Netherlands)

Malviya, Gaurav; D'Alessandria, Calogero; Bonanno, Elena; Vexler, Vladimir; Massari, Roberto; Trotta, Carlo; Scopinaro, Francesco; Dierckx, Rudi; Signore, Alberto

2009-01-01

Visilizumab is an IgG(2) humanized monoclonal antibody (mAb) characterized by non-Fc gamma R binding and specific to the CD3 antigen, expressed on more than 95% of circulating resting T-lymphocytes and on activated T-lymphocytes homing in inflamed tissues. We hypothesized that the use of a

Radioprotective effect of antioxidants on human blood lymphocytes

International Nuclear Information System (INIS)

Wang Mingsuo; Gu Xuandi; Zhu Genbo; Feng Jixing; Su Liaoyuan

1991-09-01

By using an improved fluorometric method with 2-thiobarbituric acid (TBA) as fluorometric agent, the antiradiation effects of four kinds of antioxidants on 60 Co γ-ray irradiation inducing final products of lipid peroxides (LPO), i.e. malodialdehyde (MDA) content changes in human blood lymphocytes, were investigated with LPO value as an indicator. The results of the experiment were as following: (1)The radioprotective effect of exogenous antioxidants added to human blood lymphocytes on radiation-induced LPO damage of cellular membrane were remarkable; (2)The radioprotective beneficial sequences of four kinds of antioxidants were arranged like this: SOD > VE >VC, Se 4+ ; (3)Radioprotective effects of antioxidants on radiation-induced damage varied especially with the property of antioxidants, drug concentration, and pretreatment and monitoring time, etc., as well as irradiated dosage and various kinds of incubated cells. In addition, the mechanism of these antioxidants as radioprotectants on human blood lymphocytes is discussed in connection with LPO damage and radioprotection

Elimination of radiation-induced chromosome damages in human peripheral blood lymphocyte cultures. 2. The frequency of aberrations in the first-fifth post-irradiation mitosis

International Nuclear Information System (INIS)

Pyatkin, E.K.; Pokrovskaya, V.N.; Nugis, V.Yu.

1982-01-01

The number of chromosome aberrations in 1.-5. mitoses cultivated from lymphocyte PHA of peripheric man blood after gamma irradiation in vitro in 1e5; 3 and 6 Gy has been determined. For all the doses, as the cells passed 1. and successive postradiation divisiops, observed was the decrease in the number of aberrant metaphases and all the aberrations of the chromosomal typee at that their elimination rate increases with the dose increase. No considerable differences in the frequency of pair fragments in 1.-4. mitosis after irradiation in 1,5 Gy dose, in 1.-3. mitoses after irradiation in 3 Gy dose and in 1.-2. mitoses after irradiation in 6 Gy dose were found. In lymphocyte cultures irradiated in 3 and 6 Gy doses the number of dicentries in 2. mitosis was approximately 2 times smaller than in 1. mitosis and in 3. mitosis two times smaller than in 2. mitosis. In 1. mitosis almost all the dicentrics have accompanying pair fragments in 2. and 3. mitoses a share of the dicentrics without fragments constituted about 30-70 %, and in 4.-5. mitoses amounted to 95-100 %. The reduction of the number of irregular chromosomes in the process of cell passing of 1. and successive postradiation mitosis was noted only during lymphocyte investigation irradiated in 6 Gy. At 1,5 and 3 Gy doses these aberration frequency in 1.-5. and 1.-4. mitoses were nearly the same

Influence factors of human T lymphocyte co-stimulatory effect in vitro

International Nuclear Information System (INIS)

Zhou Jianhua; Su Liaoyuan; Tong Jian; Xue Lian

2000-01-01

Objective: Effects of CD3 McAb, CD28 McAb, PHA and low-dose γ-ray irradiation on T lymphocytes were investigated to explore factors of influencing T cell signals transduction. Method: Using CD3 McAb and CD28 McAb mimicking as the first and the second signals, and using PHA and low dose γ-rays irradiation as stimulatory factors in T cell activation, the influences of these factors and the two signals on human lymphocyte proliferation response were studied with 3 H-thymidine incorporation. Results: Lymphocyte proliferation response occurred when the two signals were treated co-stimulation or within certain intervals (within 40h). PHA and 10 cGy γ-rays irradiation can also activate lymphocytes to proliferate. However, each of the two signals alone did not activate lymphocytes to proliferate. Conclusion: CD3 McAb, CD28 McAb, PHA and low-dose γ-rays irradiation could stimulate T lymphocyte proliferation, which is an important aspect in cellular immune regulation

Gamma irradiation reduces the immunological toxicity of doxorubicin, anticancer drug

Energy Technology Data Exchange (ETDEWEB)

Kim, Jae-Hun; Sung, Nak-Yun; Raghavendran, H. Balaji; Yoon, Yohan; Song, Beom-Seok; Choi, Jong-il [Team for Radiation Food Science and Biotechnology, Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup 580-185 (Korea, Republic of); Yoo, Young-Choon [Department of Microbiology, College of Medicine, Konyang University, Daejeon 302-718 (Korea, Republic of); Byun, Myung-Woo [Team for Radiation Food Science and Biotechnology, Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup 580-185 (Korea, Republic of); Hwang, Young-Jeong [Division of Food Science, International University of Korea, Jinju 660-759 (Korea, Republic of); Lee, Ju-Woon [Team for Radiation Food Science and Biotechnology, Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup 580-185 (Korea, Republic of)], E-mail: sjwlee@kaeri.re.kr

2009-07-15

Doxorubicin (DOX) is a widely used anticancer agent, but exhibits some immunological toxicity to patients during chemotherapy. The present study was conducted to evaluate the effect of gamma irradiation on the immunological response and the inhibition activity on in vivo tumor mass of DOX. The results showed that DOX irradiated at 10 and 20 kGy reduce the inhibition of mouse peritoneal macrophage proliferation and induce the release of cytokines (TNF-{alpha} and IL-6) when compared with non-irradiated DOX. The cytotoxicity against human breast (MCF-7), murine colon adenocarcinoma (Colon 26) and human monocytic (THP-1) tumor cell were not significantly different between non-irradiated and irradiated DOX (P<0.05). In vivo study on the tumor mass inhibition, gamma-irradiated DOX showed a considerable inhibition of tumor mass and this effect was statistically non-significant as compared with non-irradiated DOX. In conclusion, gamma irradiation could be regarded as a potential method for reducing the immunological toxicity of DOX. Further researches is needed to reveal the formation and activity of radiolysis products by gamma irradiation.

Gamma irradiation reduces the immunological toxicity of doxorubicin, anticancer drug

International Nuclear Information System (INIS)

Kim, Jae-Hun; Sung, Nak-Yun; Raghavendran, H. Balaji; Yoon, Yohan; Song, Beom-Seok; Choi, Jong-il; Yoo, Young-Choon; Byun, Myung-Woo; Hwang, Young-Jeong; Lee, Ju-Woon

2009-01-01

Doxorubicin (DOX) is a widely used anticancer agent, but exhibits some immunological toxicity to patients during chemotherapy. The present study was conducted to evaluate the effect of gamma irradiation on the immunological response and the inhibition activity on in vivo tumor mass of DOX. The results showed that DOX irradiated at 10 and 20 kGy reduce the inhibition of mouse peritoneal macrophage proliferation and induce the release of cytokines (TNF-α and IL-6) when compared with non-irradiated DOX. The cytotoxicity against human breast (MCF-7), murine colon adenocarcinoma (Colon 26) and human monocytic (THP-1) tumor cell were not significantly different between non-irradiated and irradiated DOX (P<0.05). In vivo study on the tumor mass inhibition, gamma-irradiated DOX showed a considerable inhibition of tumor mass and this effect was statistically non-significant as compared with non-irradiated DOX. In conclusion, gamma irradiation could be regarded as a potential method for reducing the immunological toxicity of DOX. Further researches is needed to reveal the formation and activity of radiolysis products by gamma irradiation.

The influence of interleukin-2, feeder cells, and timing of irradiation on the radiosensitivity of human T lymphocytes assessed by the colony-forming assay

International Nuclear Information System (INIS)

Gerber, M.; Guichard, M.; Pioch, Y.; Dubois, J.B.

1989-01-01

The radiosensitivity of human lymphocytes was investigated by the method of colony formation in the absence of interleukin-2 (IL2) and feeder cells, both of which enhance growth of T-cell colonies. The shape of the survival curve and the radiosensitivity was shown to depend upon the ability of lymphocytes to produce IL2: the survival curve for lymphocytes that were the most competent producers of IL2 is the closest to linearity; the lymphocytes that were poor producers show biphasic survival curves. The radiosensitivity of the lymphocytes from the first group is less than that of the latter, when the comparison is based on the first part of the biphasic survival curve. This is more easily seen when cultures are irradiated 24 h after stimulation by phytohemagglutinin (the time of the peak IL2 production) than when cultures are irradiated 2 h before stimulation. This study demonstrates that growth conditions influence the response of lymphocytes to irradiation and that optimal growth conditions result in a linear survival curve

Carcinostatic effects of platinum nanocolloid combined with gamma irradiation on human esophageal squamous cell carcinoma.

Science.gov (United States)

Li, Qiang; Tanaka, Yoshiharu; Saitoh, Yasukazu; Tanaka, Hiroshi; Miwa, Nobuhiko

2015-04-15

To explore the carcinostatic effects of platinum nanocolloid (Pt-nc) combined with gamma rays on human esophageal squamous cell carcinoma (ESCC). ESCC-derived KYSE-70 cells were treated with various concentrations of Pt-nc and/or gamma irradiation, and subsequently cultured in phenol red free DMEM with 10% FBS for 48 h. The proliferative status of the KYSE-70 cells was evaluated using trypan blue dye exclusion and WST-8 assays. Cellular and nucleic morphological aspects were evaluated using crystal violet and Hoechst 33342 stainings, respectively. Radiosensitivity was quantified by a cell viability assay, and the activated form of caspase-3, a characteristic apoptosis-related protein, was detected by Western blotting. Although single treatment with either Pt-nc or gamma irradiation could slightly inhibit the growth of the KYSE-70 cells, their combination exerted remarkable carcinostatic effects in a manner dependent on either Pt-nc concentrations or gamma ray doses, compared with the effect of each treatment alone (pirradiated with gamma rays, were shown to undergo distinct apoptotic morphological changes. The carcinostatic effect of gamma rays at 7 Gy without Pt-nc was approximately equal to that when 3-Gy irradiation was combined with 100 ppm Pt-nc or that 5-Gy irradiation was combined with 50 ppm Pt-nc. Pt-nc in combination with gamma rays may exert a cooperative effect through platinum- or gamma ray-induced apoptosis resulting in the inhibition of growth of cancer cells, while concurrently enabling the lowering of the radiative dose. Copyright © 2015 Elsevier Inc. All rights reserved.

Improvement of techniques for the detection of radio-induced micronuclei in human blood lymphocytes

Energy Technology Data Exchange (ETDEWEB)

Voisin, P.; Paillole, N.

1995-12-31

Scoring of micronuclei in cytokinesis-blocked peripheral human lymphocytes, after an accidental overexposure, seems an easier and faster alternative for biological dosimetry than conventional cytogenetics (dicentric chromosomes). Several variations of the cytokinesis-block micronucleus assay have been tested, in order to obtain a sufficient number of micronuclei in bi-nucleated cells by the shortest time possible for operational purposes. The methods differ in the use of hypotonic treatment as well as culture time (48 to 72 h), amount of blood and materials used. We have compared frequencies of bi-nucleated cells and micronuclei in normal lymphocytes and after {gamma}-({sup 60}Co) irradiation in vitro with {sup 60}Co for doses up to 6 Gy. Main results and the final choice of the technique are presented. (authors). 3 refs., 3 figs.

Detection and quantification of live, apoptotic, and necrotic human peripheral lymphocytes by single-laser flow cytometry.

Science.gov (United States)

Liegler, T J; Hyun, W; Yen, T S; Stites, D P

1995-05-01

Regulation of peripheral lymphocyte number involves a poorly understood balance between cell renewal and loss. Disrupting this balance leads to a large number of disease states. Methods which allow qualitative and quantitative measurements of cell viability are increasingly valuable to studies directed at revealing the mechanisms underlying apoptotic and necrotic cell death. Here, we have characterized a method using single-laser flow cytometry that differentiates and quantifies the relative number of live, apoptotic, and late-stage apoptotic and necrotic peripheral lymphocytes. Following in vitro gamma irradiation and staining with acridine orange in combination with ethidium bromide, three distinct populations were seen by bivariate analysis of green versus red fluorescence. The identity of each distinct fluorescent population (whether live, apoptotic, or necrotic) was determined by sorting and examination of cellular morphology by electron microscopy. This flow cytometric method is directly compared with the techniques of trypan blue exclusion and DNA fragmentation to quantify cell death following exposure to various doses of in vitro gamma irradiation and postirradiation incubation times. We extend our findings to illustrate the utility of this method beyond analyzing radiation-induced apoptotic peripheral blood mononuclear cells (PBMC); similar fluorescent patterns are shown for radiation- and corticosteroid-treated murine thymocytes, activated human PBMC, and PBMC from human immunodeficiency virus-infected individuals. Our results demonstrate that dual-parameter flow cytometric analysis of acridine orange-ethidium bromide-stained lymphocytes is overall a superior method with increased sensitivity, greater accuracy, and decreased subjectivity in comparison with the other methods tested. By using standard laser and filter settings commonly available to flow cytometric laboratories, this method allows rapid measurement of a large number of cells from a

Economics of gamma irradiation processing

International Nuclear Information System (INIS)

Tani, Toshio

1980-01-01

The gamma-ray irradiation business started at the Takasaki Laboratory of Japan Atomic Energy Research Institute. The irradiation facilities were constructed thereafter at various sites. The facilities must accept various types of irradiation, and must be constructed as multi-purpose facilities. The cost of irradiation consists of the cost of gamma sources, construction expense, personnel expense, management expense, and bank interest. Most of the expenses are considered to be fixed expense, and the amount of irradiation treatment decides the original costs of work. The relation between the irradiation dose and the construction expense shows the larger facility is more economical. The increase of amount of treatment reduces the original cost. The utilization efficiency becomes important when the amount of treatment and the source intensity exceed some values. The principal subjects of gamma-ray irradiation business are the sterilization of medical tools and foods for aseptic animals, the improvement of quality of plastic goods, and the irradiation of foods. Among them, the most important subject is the sterilization of medical tools. The cost of gamma irradiation per m 3 in still more expensive than that by ethylene oxide gas sterilization. However, the demand of gamma-ray irradiation is increasing. For the improvement of quality of plastic goods, electron irradiation is more favourable than the gamma irradiation. In near future, the economical balance of gamma irradiation can be achieved. (Kato, T.)

The evaluation of protective effect of lycopene against genotoxic influence of X-irradiation in human blood lymphocytes

International Nuclear Information System (INIS)

Gajowik, Aneta; Dobrzynska, Malgorzata M.

2017-01-01

Many studies suggest that exogenous antioxidants may protect cells against DNA damage caused with ionizing radiation. One of the most powerful antioxidants is lycopene (LYC), a carotenoid derived from tomatoes. The aim of this study was to investigate, using the comet assay, whether LYC can act as protectors/modifiers and prevent DNA damage induced in human blood lymphocytes, as well as to mitigate the effects of radiation exposure. In this project, LYC, dissolved in DMSO at a concentration of 10, 20 or 40 μM/ml of cell suspension, was added to the isolated lymphocytes from human blood at appropriate intervals before or after the X-irradiation at doses of 0.5, 1 and 2 Gy. Cell viability in all groups was maintained at above 70%. The results showed the decrease of DNA damage in cells treated with various concentrations of LYC directly and 1 h before exposure to X-rays compared to the control group exposed to irradiation alone. Contrary results were observed in cells exposed to LYC immediately after exposure to ionizing radiation. The studies confirmed the protective effect of LYC against DNA damage induced by ionizing radiation, but after irradiation the carotenoid did not stimulate of DNA repair and cannot act as modifier. However, supplementation with LYC, especially at lower doses, may be useful in protection from radiation-induced oxidative damage. (orig.)

The evaluation of protective effect of lycopene against genotoxic influence of X-irradiation in human blood lymphocytes

Energy Technology Data Exchange (ETDEWEB)

Gajowik, Aneta; Dobrzynska, Malgorzata M. [National Institute of Public Health-National Institute of Hygiene, Department of Radiation Protection and Radiobiology, Warsaw (Poland)

2017-11-15

Many studies suggest that exogenous antioxidants may protect cells against DNA damage caused with ionizing radiation. One of the most powerful antioxidants is lycopene (LYC), a carotenoid derived from tomatoes. The aim of this study was to investigate, using the comet assay, whether LYC can act as protectors/modifiers and prevent DNA damage induced in human blood lymphocytes, as well as to mitigate the effects of radiation exposure. In this project, LYC, dissolved in DMSO at a concentration of 10, 20 or 40 μM/ml of cell suspension, was added to the isolated lymphocytes from human blood at appropriate intervals before or after the X-irradiation at doses of 0.5, 1 and 2 Gy. Cell viability in all groups was maintained at above 70%. The results showed the decrease of DNA damage in cells treated with various concentrations of LYC directly and 1 h before exposure to X-rays compared to the control group exposed to irradiation alone. Contrary results were observed in cells exposed to LYC immediately after exposure to ionizing radiation. The studies confirmed the protective effect of LYC against DNA damage induced by ionizing radiation, but after irradiation the carotenoid did not stimulate of DNA repair and cannot act as modifier. However, supplementation with LYC, especially at lower doses, may be useful in protection from radiation-induced oxidative damage. (orig.)

Effect of in vitro x-irradiation on human peripheral blood T and B lymphocytes

International Nuclear Information System (INIS)

Prusek, W.; Astaldi, G.

1979-01-01

The effect of in vitro irradiation with increasing in logarythmic progress X-ray doses on lymphocyte viability and on T and B lymphocyte populations was studied in normal adults, patients with myasthenia gravis and in patients undergoing long-term steroid therapy. Decrease in numbers of lymphocytes carrying T or B lymphocyte surface markers was higher than the viable cell loss. The decrease showed no linear correlation with X-ray doses applied, which might reflect the existence of radioresistant T and B lymphocytes. A higher so-called early radiosensitivity of B lymphocytes was demonstrated. In patients with myasthenia gravis early radioresistance of T lymphocytes was detected. In patients undergoing long-term steroid therapy, an increase in numbers of cells lacking markers of any of lymphocyte populations was found in parallel with a decrease in T lymphocyte number which, in these patients, showed a higher radiosensitivity. (author)

Effect of in vitro x-irradiation on human peripheral blood T and B lymphocytes

Energy Technology Data Exchange (ETDEWEB)

Prusek, W. (Szpital Wojewodzki, Wroclaw (Poland)); Astaldi, G. (The Blood Research Foundation Centre, Tortona (Italy))

1979-01-01

The effect of in vitro irradiation with increasing in logarythmic progress X-ray doses on lymphocyte viability and on T and B lymphocyte populations was studied in normal adults, patients with myasthenia gravis and in patients undergoing long-term steroid therapy. Decrease in numbers of lymphocytes carrying T or B lymphocyte surface markers was higher than the viable cell loss. The decrease showed no linear correlation with X-ray doses applied, which might reflect the existence of radioresistant T and B lymphocytes. A higher so-called early radiosensitivity of B lymphocytes was demonstrated. In patients with myasthenia gravis early radioresistance of T lymphocytes was detected. In patients undergoing long-term steroid therapy, an increase in numbers of cells lacking markers of any of lymphocyte populations was found in parallel with a decrease in T lymphocyte number which, in these patients, showed a higher radiosensitivity.

Cytogenetic analysis of the combined action of pesticides and radiation on human lymphocytes

International Nuclear Information System (INIS)

Ryabchenko, N.I.; Fesenko, Eh.V.; Antoshchina, M.M.

1995-01-01

The efficiency of the combined action of pesticides and irradiation at the G 0 stage was studied in cultured human lymphocytes. Carbophos (malathion) increased the yield of chromosome and chromatid fragments in irradiated lymphocytes. Herbicide 2,4-D (dichlorophenoxyacetic acid) raised lymphocyte radiosensitivity by increasing the yield of chromosome type aberrations, the radiosensitizing effect of the herbicide decreased as its concentration increased. 4 refs

Cellular response to low Gamma-ray doses

Energy Technology Data Exchange (ETDEWEB)

Manzanares A, E; Vega C, H R; Leon, L.C. de . [Unidades Academicas de Estudios Nucleares, Universidad Autonoma de Zacatecas, A.P. 336, 98000 Zacatecas (Mexico); Rebolledo D, O; Radillo J, F [Facultad de Ciencias Biologicas y Agropecuarias de la Universidad de Colima, Colima (Mexico)

2002-07-01

Lymphocytes, obtained from healthy donors, were exposed to a low strength gamma-ray field to determine heat shock protein expression in function of radiation dose. Protein identification was carried out using mAb raised against Hsp70 and Hsc70.Hsp70 protein was detected after lymphocyte irradiation. In all cases, an increasing trend of relative amounts of Hsp70 in function to irradiation time was observed. After 1.25 c Gy gamma-ray dose, lymphocytes expressed Hsp70 protein, indicating a threshold response to gamma rays. (Author)

Cellular response to low Gamma-ray doses

International Nuclear Information System (INIS)

Manzanares A, E.; Vega C, H.R.; Leon, L.C. de; Rebolledo D, O.; Radillo J, F.

2002-01-01

Lymphocytes, obtained from healthy donors, were exposed to a low strength gamma-ray field to determine heat shock protein expression in function of radiation dose. Protein identification was carried out using mAb raised against Hsp70 and Hsc70.Hsp70 protein was detected after lymphocyte irradiation. In all cases, an increasing trend of relative amounts of Hsp70 in function to irradiation time was observed. After 1.25 c Gy gamma-ray dose, lymphocytes expressed Hsp70 protein, indicating a threshold response to gamma rays. (Author)

The effect of γ-irradiation on the toxicity of malathion in V79 hamster cells and Molt-4 human lymphocytes

International Nuclear Information System (INIS)

Szekely, J.G.; Goodwin, M.; Delaney, S.

1992-01-01

There is a growing interest in irradiation of food and agricultural products for insect disinfestation, sprout inhibition, delayed ripening and the reduction of microbiological loads. Irradiation to a maximum dose of 10 kGy is recognized as safe by national and international regulatory agencies. To address the question, whether irradiation of pesticide residues might produce radiation products that were less or more toxic than the original pesticide, effects were observed of 10 kGy of γ-radiation on malathion as measured by sister-chromatid exchange (SCE), micronuclei formation, cell survival, growth rate and polyploid formation. No significant differences were found between effects of irradiated and unirradiated malathion on any of these end- points. Polyploid formation was the most dramatic effect of both irradiated and control malathion on V79 Chinese hamster cells. Cell survival, polyploid formation and growth rate were slightly better in cells treated with irradiated malathion. In Molt-4 human lymphocyte cell, micronuclei formation was not affected by unirradiated or irradiated malathion. Compared to malathion alone, the lack of such biological effects indicates that none of the presumed radiation-induced breakdown products increased or decreased the endpoints studied. The number of SCE was consistently, but not significantly, higher in cells treated with irradiated malathion. There were no significant differences in cell survival or micronucleus formation in the human lymphocyte cell line Molt-4 treated with irradiated or control malathion. Thus, the irradiation of the pesticide malathion to 10 kGy, a recommended upper dose for most food irradiations, does not significantly alter its toxicity in these in vitro systems. (author). 23 refs.; 4 figs.; 3 tabs

Effect of low dose x-irradiation on alloantigen sensitized and unsensitized lymphocytes

Energy Technology Data Exchange (ETDEWEB)

Dohi, Kiyohiko; Yahata, Hiroshi; Fukuda, Yasuhiko; Asahara, Toshimasa; Ono, Eiji; Ezaki, Haruo

1984-12-01

The effect of local graft irradiation on immune response in allograft in which acute rejection occurs was studied using an in vitro model. Unidirectional mixed lymphocyte culture (MLC) was used as the in vitro model of acute rejection. 150 and 300 rad x-irradiation suppressed mixed lymphocyte reaction (MLR) but did not cell-mediated-lympholysis (CML) of unsensitized lymphocytes. X-irradiated alloantigen sensitized cells (ASC) generated in 6-day MLC suppressed MLR and CML of unsensitized lymphocytes. Suppressive effects of x-irradiated ASC were of the same degree by x-irradiation doses of 150-500 rad. Suppressive effect of x-irradiation was maintained for only a short period after x-irradiation. Potential function of suppressor precursor cells among unsensitized lymphocytes was abolished by x-irradiation of 300 rad. (author).

Dose-rate effects for apoptosis and micronucleus formation in gamma-irradiated human lymphocytes

International Nuclear Information System (INIS)

Boreham, D.R.; Dolling, J.-A.; Maves, S.R.; Siwarungsun, N.; Mitchel, R.E.J.

2000-01-01

We have compared dose-rate effects for γ-radiation-induced apoptosis and micronucleus formation in human lymphocytes. Long-term assessment of individual radiation-induced apoptosis showed little intraindividual variation but significant interindividual variation. The effectiveness of radiation exposure to cause apoptosis or micronucleus formation was reduced by low-dose-rate exposures, but the reduction was apparent at different dose rates for these two end points. Micronucleus formation showed a dose-rate effect when the dose rate was lowered to 0.29 cGy/min, but there was no accompanying cell cycle delay. A further increase in the dose-rate effect was seen at 0.15 cGy/min, but was now accompanied by cell cycle delay. There was no dose-rate effect for the induction of apoptosis until the dose rate was reduced to 0.15 cGy/min, indicating that the mechanisms or signals for processing radiation-induced lesions for these two end points must be different at least in part. There appear to be two mechanisms that contribute to the dose-rate effect for micronucleus formation. One of these does not affect binucleate cell frequency and occurs at dose rates higher than that required to produce a dose-rate effect for apoptosis, and one affects binucleate cell frequency, induced only at the very low dose rate which coincidentally produces a dose-rate effect for apoptosis. Since the dose rate at which cells showed reduced apoptosis as well as a further reduction in micronucleus formation was very low, we conclude that the processing of the radiation-induced lesions that induce apoptosis, and some micronuclei, is very slow in quiescent and PHA-stimulated lymphocytes, respectively. (author)

Microwaves from GSM mobile telephones affect 53BP1 and gamma-H2AX foci in human lymphocytes from hypersensitive and healthy persons.

Science.gov (United States)

Markovà, Eva; Hillert, Lena; Malmgren, Lars; Persson, Bertil R R; Belyaev, Igor Y

2005-09-01

The data on biologic effects of nonthermal microwaves (MWs) from mobile telephones are diverse, and these effects are presently ignored by safety standards of the International Commission for Non-Ionizing Radiation Protection (ICNIRP). In the present study, we investigated effects of MWs of Global System for Mobile Communication (GSM) at different carrier frequencies on human lymphocytes from healthy persons and from persons reporting hypersensitivity to electromagnetic fields (EMFs). We measured the changes in chromatin conformation, which are indicative of stress response and genotoxic effects, by the method of anomalous viscosity time dependence, and we analyzed tumor suppressor p53-binding protein 1 (53BP1) and phosphorylated histone H2AX (gamma-H2AX), which have been shown to colocalize in distinct foci with DNA double-strand breaks (DSBs), using immunofluorescence confocal laser microscopy. We found that MWs from GSM mobile telephones affect chromatin conformation and 53BP1/gamma-H2AX foci similar to heat shock. For the first time, we report here that effects of MWs from mobile telephones on human lymphocytes are dependent on carrier frequency. On average, the same response was observed in lymphocytes from hypersensitive and healthy subjects.

Human cytotoxic T-lymphocyte membrane-camouflaged nanoparticles combined with low-dose irradiation: a new approach to enhance drug targeting in gastric cancer

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Zhang L

2017-03-01

Full Text Available Lianru Zhang, Rutian Li, Hong Chen, Jia Wei, Hanqing Qian, Shu Su, Jie Shao, Lifeng Wang, Xiaoping Qian, Baorui Liu The Comprehensive Cancer Centre of Drum Tower Hospital, Medical School of Nanjing University and Clinical Cancer Institute of Nanjing University, Nanjing, People’s Republic of China Abstract: Cell membrane-derived nanoparticles are becoming more attractive because of their ability to mimic many features of their source cells. This study reports on a biomimetic delivery platform based on human cytotoxic T-lymphocyte membranes. In this system, the surface of poly-lactic-co-glycolic acid nanoparticles was camouflaged using T-lymphocyte membranes, and local low-dose irradiation (LDI was used as a chemoattractant for nanoparticle targeting. The T-lymphocyte membrane coating was verified using dynamic light scattering, transmission electron microscopy, and confocal laser scanning microscopy. This new platform reduced nanoparticle phagocytosis by macrophages to 23.99% (P=0.002. Systemic administration of paclitaxel-loaded T-lymphocyte membrane-coated nanoparticles inhibited the growth of human gastric cancer by 56.68% in Balb/c nude mice. Application of LDI at the tumor site significantly increased the tumor growth inhibition rate to 88.50%, and two mice achieved complete remission. Furthermore, LDI could upregulate the expression of adhesion molecules in tumor vessels, which is important in the process of leukocyte adhesion and might contribute to the localization of T-lymphocyte membrane-encapsulated nanoparticles in tumors. Therefore, this new drug-delivery platform retained both the long circulation time and tumor site accumulation ability of human cytotoxic T lymphocytes, while local LDI could significantly enhance tumor localization. Keywords: cell membrane, drug delivery system, gastric cancer, low-dose irradiation, nanoparticles

Effects of whole-body cobalt 60 gamma irradiation on the young korean native goats

International Nuclear Information System (INIS)

Kim, Jong Gyu; Sung, Jai Ki

1989-01-01

This study was carried out to investigate the effects of whole-body cobolt-60 gamma irradiation on clinical signs, mortality, hematological, blood chemical, chromosomal and pathologic changes in the young Korean native goats. Groups of goats were exposed to 200, 400, 600 and 800 rads of gamma irradiation from a cobalt-60 source. Clinical signs such as diarrhea, anorexia, weakness and depression of the irradiated goats were observed. Mortalities were 66.7 percent in the group irradiated with 200 rads and 100 percent in the groups irradiated with higher doses. Death times were shortened with the increment of irradiation doses. With time after irradiation, the values of erythrocytes, hemoglobin and packed cell volume decreased in the 200 and 400 rads groups and increased in the 600 and 800 rads groups. The number of total leukocytes of the irradiated goats decreased significantly in all irradiated groups. The degrees of decrease were severe as the irradiated doses were increased. Significant decrease of lymphocyte counts were observed from 6 hours in the 800 rads group and 1 day post irradiation(PI) in all other groups. Post irradiation times for significant reduction of neutrophils were 1, 3, 3 and 5 days for 800, 600, 400 and 200 rads groups, respectively. Serum sorbitol dehydrogenase and serum aspartate aminotransferase activities increased remarkably at 6 hours PI in the 800 rads group and 1 day PI in all other groups. Thereafter the activities returned to normal values. Since mitoses of lymphocytes were completely inhibited in blood cultures of all irradiated goats, chromosomal pictures could not be observed. However, mitoses were observed on 28 days PI in 200 rads group and no abberration in the number and structures of lymphocyte chromosomes were detected. Histopathologic findings in various organs of the irradiated goats were severe necrosis and depletion of lymphoid cells in the lymph nodes and spleen, hypoplasia of hemopoietic cells in the bone marrow

Adaptive response induced by low doses of ionizing radiation in human lymphocytes

International Nuclear Information System (INIS)

Frati, Diego Libkind; Bunge, Maria M.

2001-01-01

The term adaptive response (AR) applies to the phenomenon of protection or enhanced repair induced by a small dose of a mutagenic agent. In order to determine the existence of AR in human lymphocytes for two different irradiation schemes, microcultures of blood from 4 donors were irradiated. Samples were exposed 24 hours (hr) after phytohemagglutinin stimulation to an adapting dose of 0,01 Gy and to a challenging dose of 1,5 Gy either 6 or 24 hr later (irradiation scheme 24+30 or 24+48, respectively). Gamma radiation from a 2,5 MeV Linac was used in all experiments. A cytogenetic analysis of unstable chromosome aberrations was applied as the endpoint. High inter-individual variability was found for the first irradiation scheme: one expressed AR, two did not and the last showed an apparent synergistic response. For the second irradiation scheme, low mitotic indices (MI) were found, suggesting a G2 arrest. When a series of harvesting times were applied for the last donor, normal MI were obtained only harvesting after 58 hr. An AR was found when harvesting at 72 hr but not at 58 hr. (author)

Gamma-irradiated scrub typhus immunogens: development of cell-mediated immunity after vaccination of inbred mice

International Nuclear Information System (INIS)

Jerrells, T.R.; Palmer, B.A.; Osterman, J.V.

1983-01-01

Mice immunized with three injections of gamma-irradiated Karp strain of Rickettsia tsutsugamushi were evaluated for the presence of cell-mediated immunity by using delayed-type hypersensitivity, antigen-induced lymphocyte proliferation, and antigen-induced lymphokine production. These animals also were evaluated for levels of circulating antibody after immunization as well as for the presence of rickettsemia after intraperitoneal challenge with viable Karp rickettsiae. After immunization with irradiated Karp rickettsiae, a demonstrable cell-mediated immunity was present as evidenced by delayed-type hypersensitivity responsiveness, lymphocyte proliferation, and production of migration inhibition factor and interferon by immune spleen lymphocytes. Also, a reduction in circulating rickettsiae was seen in mice immunized with irradiated rickettsiae after challenge with 1,000 50% mouse lethal doses of viable, homologous rickettsiae. All responses except antibody titer and reduction of rickettsemia were similar to the responses noted in mice immunized with viable organisms. Antibody levels were lower in mice immunized with irradiated rickettsiae than in mice immunized with viable rickettsiae. Furthermore, mice that were immunized with viable rickettsiae demonstrated markedly lower levels of rickettsemia after intraperitoneal challenge compared with either mice immunized with irradiated rickettsiae or nonimmunized mice

Synthesis of pro-inflammatory cytokines and adhesion molecules expression by the irradiated human monocyte/macrophage

International Nuclear Information System (INIS)

Pons, I.

1997-09-01

As lesions induced by ionizing radiations are essentially noticed in organs the functional and structural organisation of which depend on the highly proliferative stem cell pool, the author reports an in-vivo investigation of the effect of a gamma irradiation on the expression and secretion of pro-inflammatory cytokines par human monocytes/macrophages. In order to study the role of the cell environment in the radiation-induced inflammation, the author studied whether a co-stimulation of monocytes/macrophages by gamma irradiation, or the exposure of co-cultures of monocytes/macrophages and lymphocytes, could modulate the regulation of inflammatory cytokines. The author also studied the modulation of the expression of adhesion molecules mainly expressed by the monocyte/macrophage, and the membrane density of the CD14 receptor after irradiation of monocytes/macrophages during 24 hours, and of totally differentiated macrophages after seven days of culture

B and T lymphocytes in man. I. Effect of infant thymic irradiation on the circulating B and T lymphocytes

International Nuclear Information System (INIS)

Reddy, M.M.; Goh, K.; Hempelmann, L.H.

1976-01-01

B and T lymphocytes were studied in a group of adults whose thymic glands were irradiated in infancy for alleged thymic enlargement. Two independent methods were used to determine the B and T lymphocytes from each peripheral blood specimen: (1) the relative proportion of cells with surface immunoglobulins (B lymphocytes) and cells forming rosettes with sheep erythrocytes (T lymphocytes); and (2) the relative mitogenic response to phytohemagglutinin (T lymphocytes) and to pokeweed mitogen (B lymphocytes). All specimens were coded. The results obtained indicate: (1) a reduction of B and T lymphocytes; and (2) a decreased mitogenic response of lymphocytes to phytohemagglutinin and pokeweed mitogen in this group of patients as compared with the controls. These observations suggest that (1) the effect of irradiation to the thymus gland on lymphocytes is long lasting and (2) both B and T lymphocytes are affected by irradiation to the thymus gland

Dose response curve for prematurely condensed chromosome fragments of human lymphocytes after 60Co-γ ray exposure

International Nuclear Information System (INIS)

Gao Jinsheng; Zheng Siying; Bao Hong

1992-06-01

The dose-effect relationship of premature condensed chromosome fragments in human lymphocytes irradiated by 60 Co gamma ray was studied by PCC method (premature condensed chromosomes). In addition, The conventional cellular genetics method was also used in the study. The response curve of both methods can represented by two linear equations. The ratio of two slopes, K PCC /K M1 , is about 28. Comparing with conventional method, the PCC method has many advantages such as faster, simpler, more sensitive and accurate. The PCC method used in the studying of radiation damage is also discussed

Dose-response relationship of γ-H2AX foci induction in human lymphocytes after X-rays exposure

International Nuclear Information System (INIS)

Mandina, Tania; Roch-Lefevre, Sandrine H.; Voisin, Pascale; Gonzalez, Jorge E.; Lamadrid, Ana I.; Romero, Ivonne; Garcia, Omar; Voisin, Philippe; Roy, Laurence

2011-01-01

Biological dosimeters are recommended for dose estimation in case of human overexposure to ionising radiation. Rapid measurement of γ-H2AX foci as a marker of DNA double-strand breaks (DSB) induction has been recently tested with this purpose. Here we reported a dose-response relationship after X-ray irradiation at different times post-exposure. Blood samples were obtained from several healthy donors and exposed to doses between 0 and 2 Gy. After irradiation, blood samples were incubated at 37 deg. C during 0.5 h, 5 h, and 8 h. Scoring of cells and γ-H2AX foci was performed by software. The dose-response curves for different incubation times were as follows: Y (0.5h) = 11.66D + 0.15 (R 2 = 0.99), Y (5h) = 2.44D + 0.15 (R 2 = 0.99), Y (8h) = 1.57D + 0.22 (R 2 = 0.99). At 0.5 h post-exposure, the dose-response relationship for X-irradiated lymphocytes was similar to the one obtained after gamma-irradiation using the same protocol. On the other hand, the results were not similar after 8 h due to different kinetics after gamma- and X-irradiation. Our results confirm the possibilities of using γ-H2AX foci method for dose estimation in a period from 0.5 h up to 8 h post X-irradiation and support the hypothesis of differences in γ-H2AX foci kinetics after gamma- and X-irradiation in vitro.

Pathomorphology of spleen lymphocyte apoptosis in large dose 60Co γ-irradiated mice

International Nuclear Information System (INIS)

Gao Linlu; Cui Yufang; Yang Hong; Xia Guowei; Peng Ruiyun; Gao Yabing; Wang Dewen

2000-01-01

Objective: The aim of the authors was to investigate the pathomorphology changes of spleen lymphocyte apoptosis after 60 Co γ-irradiation. Methods: The mice were irradiated with 6, 9, 12, 15 and 20 Gy of 60 Co γ-rays. At different times after irradiation, the mice were sacrificed and the pathological changes of spleen lymphocyte were observed by light and transmission electron microscopies. Results: Spleen lymphocyte decreased evidently and the peak of apoptosis in spleen lymphocyte was dependent on radiation dose and the time after irradiation. Conclusion: After γ-irradiation with large doses, pathological changes of spleen lymphocyte apoptosis in mice can be divided into obviously different stages. The main causes of death of spleen lymphocytes are different in different dose groups

Preliminary study on biological dosimetry using alkaline single cell gel electrophoresis of human peripheral lymphocytes

International Nuclear Information System (INIS)

Liu Qingjie; Lu Xue; Feng Jiangbing; Chen Deqing; Chen Xiaosui

2006-01-01

Objective: To explore the feasibility of alkaline single cell gel electrophoresis (SCGE) in biological dosimetry of ionizing radiation. Methods: Normal peripheral blood samples from two healthy males were exposed to different doses coblat-60 gamma-rays, ranged from 0 to 5 Gy, and the tail length (TL) and Oliver tail moment (TM) of the lymphocytes were analyzed with SCGE. The dose-effect curves of TL and TM were fitted respectively. The TL and TM of lymphocytes for eight radiation workers were analyzed with SCGE, cumulative doses were estimated using the fitted TL and TM equations, and then compared with the recorded monitoring doses. Results: The TLs or TMs of normal human lymphocytes were increased with the irradiation doses, and its relationship can be fitted with a linear-quadratic equations: Y=13.59 + 20.87X - 2.27 X 2 for TL, and Y = 8.50 + 15.04X - 1.43X 2 for TM, respectively (Y denotes TL or TM value, X is radiation dose). The doses estimated with TM equation were closer to the recorded monitoring doses than that with TL equation. Conclusions: The TM in lymphocytes analyzed with SCGE is a promising radiation biological dosimeter. (authors)

Glia maturation factor gamma regulates the migration and adherence of human T lymphocytes

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Lippert Dustin ND

2012-04-01

Full Text Available Abstract Background Lymphocyte migration and chemotaxis are essential for effective immune surveillance. A critical aspect of migration is cell polarization and the extension of pseudopodia in the direction of movement. However, our knowledge of the underlying molecular mechanisms responsible for these events is incomplete. Proteomic analysis of the isolated leading edges of CXCL12 stimulated human T cell lines was used to identify glia maturation factor gamma (GMFG as a component of the pseudopodia. This protein is predominantly expressed in hematopoietic cells and it has been shown to regulate cytoskeletal branching. The present studies were undertaken to examine the role of GMFG in lymphocyte migration. Results Microscopic analysis of migrating T-cells demonstrated that GMFG was distributed along the axis of movement with enrichment in the leading edge and behind the nucleus of these cells. Inhibition of GMFG expression in T cell lines and IL-2 dependent human peripheral blood T cells with shRNAmir reduced cellular basal and chemokine induced migration responses. The failure of the cells with reduced GMFG to migrate was associated with an apparent inability to detach from the substrates that they were moving on. It was also noted that these cells had an increased adherence to extracellular matrix proteins such as fibronectin. These changes in adherence were associated with altered patterns of β1 integrin expression and increased levels of activated integrins as detected with the activation specific antibody HUTS4. GMFG loss was also shown to increase the expression of the β2 integrin LFA-1 and to increase the adhesion of these cells to ICAM-1. Conclusions The present studies demonstrate that GMFG is a component of human T cell pseudopodia required for migration. The reduction in migration and increased adherence properties associated with inhibition of GMFG expression suggest that GMFG activity influences the regulation of integrin mediated

Impairment of lymphocyte adhesion to cultured fibroblasts and endothelial cells by γ-irradiation

International Nuclear Information System (INIS)

Piela-Smith, T.H.; Aneiro, L.; Nuveen, E.; Korn, J.H.; Aune, T.

1992-01-01

A critical component of immune responsiveness is the localization of effector cells at sites of inflammatory lesions. Adhesive molecules that may play a role in this process have been described on the surfaces of both lymphocytes and connective tissue cells. Adhesive interactions of T lymphocytes with fibroblasts or endothelial cells can be inhibited by preincubation of the fibroblasts or endothelial cells with antibody to intercellular adhesion molecule 1 (CD54) or by preincubation of the T cells with antibody to lymphocyte function-associated Ag 1 (CD11a/CD18), molecules shown to be important in several other cell-cell adhesion interactions. Here the authors show that γ-irradiation of human T lymphocytes impaired their ability to adhere to both fibroblasts and endothelial cells. This impairment was not associated with a loss of cell viability or of cell surface lymphocyte function-associated Ag 1 expression. γ-Irradiation of T cells is known to result in the activation of ADP-ribosyltransferase, an enzyme involved in DNA strand-break repair, causing subsequent depletion of cellular nicotinamide adenine dinucleotide (NAD) pools by increasing NAD consumption for poly(ADP-ribose) formation. Preincubation of T cells with either nicotinamide or 3-aminobenzamide, both known inhibitors of ADP-ribosyltransferase, completely reversed the suppressive effects of γ-irradiation on T cell adhesion. The maintenance of adhesion was accompanied by inhibition of irradiation-induced depletion of cellular NAD. These experiments suggest that the impairment of cellular immune function after irradiation in vivo may be caused, in part, by defective T cell emigration and localization at inflammatory sites. 44 refs., 5 figs., 3 tabs

Gamma Irradiation does not Cause Carcinogenesis of Irradiated Herbs

International Nuclear Information System (INIS)

Thongphasuk, Jarunee; Thongphasuk, Piyanuch; Eamsiri, Jarurut; Pongpat, Suchada

2009-07-01

Full text: Microbial contamination of medicinal herbs can be effectively reduced by gamma irradiation. Since irradiation may cause carcinogenicity of the irradiated herbs, the objective of this research is to study the effect of gamma irradiation (10 and 25 kGy) from cobalt-60 on carcinogenicity. The herbs studied were Pueraria candollei Grah., Curcuma longa Linn. Zingiber montanum, Senna alexandrina P. Miller, Eurycoma Longifolia Jack, Gymnostema pentaphylum Makino, Ginkgo biloba, Houttuynia cordata T., Andrographis paniculata, Thunbergia laurifolia L., Garcinia atroviridis G., and Cinnamomum verum J.S.Presl. The results showed that gamma irradiation at the dose of 10 and 25 kGy did not cause carcinogenicity of the irradiated herbs

Cytogenetic adaptive response induced by pre-exposure in human lymphocytes and marrow cells of mice

International Nuclear Information System (INIS)

Zhang Lianzhen; Deng Zhicheng

1993-01-01

The cytogenetic adaptive response induced by pre-exposure in human lymphocytes and marrow cells of mice were studied. The results of this study showed that human lymphocytes in vitro and mouse marrow cells in vivo can become adapted to low-level irradiation from 3 H-TdR or exposure to a low dose of X-or γ-irradiation, so that they become less sensitive to the chromosomal damage effects of subsequent exposures. (4 tabs.)

Gamma irradiator

International Nuclear Information System (INIS)

Simonet, G.

1986-09-01

Fiability of devices set around reactors depends on material resistance under irradiation noticeably joints, insulators, which belongs to composition of technical, safety or physical incasurement devices. The irradiated fuel elements, during their desactivation in a pool, are an interesting gamma irradiation device to simulate damages created in a nuclear environment. The existing facility at Osiris allows to generate an homogeneous rate dose in an important volume. The control of the element distances to irradiation box allows to control this dose rate [fr

Development of Irradiation Procedure for Gamma Irradiation Chamber Bio beam GM 8000

International Nuclear Information System (INIS)

Shuhaimi Shamsudin; Affrida Abu Hassan; Zaiton Ahmad; Abdul Rahim Harun; Ahmad Zainuri Mohd Dzomir

2015-01-01

Bio Beam GM 8000 gamma irradiation chamber obtained a conditional approval to operate on March 27, 2012, and later acquired a full approval on December 13, 2012. The objective for the procurement of this gamma chamber is to develop an acute irradiation facility for biological samples, including plants tissues, insects, pupae, microorganisms, as well as animal and human cells. To ensure a smooth and efficient operation, irradiation procedures were developed and improved over time. This paper discusses the operation and management of the Bio Beam GM 8000 facility, including irradiation procedures and sample preparation, application for services through online e-client system, consultancy, quality assurance and information dissemination to internal as well as external clients. In addition, this paper also discusses the potential, constraints and improvement measures taken to optimize the use of this facility in order to meet its objectives. (author)

Protective effect of citrullus vulgaris on irradiated lymphocyte membrane ultrastructure

International Nuclear Information System (INIS)

Khairul Osman; Norashikin, M.S.; Hing Hiang Lian; Siti Fatimah Ibrahim; Seetha Khartini Abdul Wahab; Jamaludin Mohamed; Proom Promwichit

2004-01-01

Radiotherapy causes various complications including low immunity. Past research that the low immunity is due to the low amount of lymphocytes and consumption vulgaris will alleviate this problem. Based on this a study was conducted to identify vulgaris was able to produce radioprotection on the lymphocyte membrane. A total of 30 adult male Sprague-Dawley rats were used and divided into three equals groups of positive control and treatment. For seven days, positive control and negative control were force fed with normal saline of 40 ml/kg animal weight while the treatment group received 40g/kg animal weight fresh juice of citrullus vulgaris daily. After a week positive control an group were irradiated with 0.9 Gy gamma ray. Viable lymphocyte were determined using propidium iodine and acridine orange stain. Results clearly shows that positive con and treatment group were significantly different at 34 ± 3% , 80 ± 2% an 71 ± 2% respectively. SEM results shows that pores were present on the membrane of the pos while the negative control had none. Similar results were also found on the treatment group. Based on the result it had shown that citrullus vulgaris had radioprotection properties and lymphocytes were destroyed by the formation of pores on their membrane. It is very likely that the radioprotection properties could be due to the presence of antioxidants particularly vitamin A, C and lycopene. In conclusion, citrullus vulgaris could be used as a safe radioprotection agent. (Author)

Phosphorylation of histone H2AX as an indicator of received dose of gamma radiation after whole-body irradiation of rats

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Radim Havelek

2011-01-01

Full Text Available The aim of our study was to determine whether phosphorylation of histone H2AX can be used as an indicator of received dose of gamma radiation after whole-body irradiation of rats. Wistar rats were irradiated by 1-10 Gy of gamma radiation by 60Co source. Value LD50/60 was 7.37 (4.68-8.05 Gy. Histone H2AX is phosphorylated by ATM kinase on serine 139 (γH2AX quickly after the irradiation. It forms microscopically visible foci in the site of double strand breaks of DNA. Flow-cytometric method was used for quantitative detection. This study is the first one that evaluated dose-dependency of H2AX phosphorylation in peripheral lymphocytes of rats irradiated by whole-body dose 1-10 Gy. Our data show a dose-dependent increase in γH2AX in rat peripheral blood lymphocytes 1 h after whole-body irradiation by the dose of 1-10 Gy. We proved that phosphorylation of histone H2AX is a prompt and reliable indicator of the received radiation dose suitable for rapid measurement before the number of lymphocytes in peripheral blood starts to decrease. It can be used already 1 h after the irradiation for an estimation of the received dose of radiation. Blood samples can be stored in 4 °C for 23 h without significantly affecting the result.

Protective effect of red wine on the frequency of micronuclei in human lymphocytes irradiated in vitro

International Nuclear Information System (INIS)

Stankovic, M.; Joksic, G.

2000-01-01

The present investigation was undertaken to study the effect of red wines 'Cabernet Sauvignon' on the micronuclei formation in human lymphocytes. Blood samples of healthy volunteers were irratiated in vitro using 60 Co as a source of radiation, dose of 2Gy. Irradiated samples, as well as unirradiated controls, were treated with concentrations of red wine ranged from 100-500 ml/2x106 cells. Obtained results demonstrated significant decrease of the micronuclei frequency (t=9.14; p0.05) in treated samples versus untreated controls. The results of our study demonstrated radioprotective effect of red wine

T-lymphocyte dependency of B-lymphocyte blastogenic response to phytomitogens

International Nuclear Information System (INIS)

Han, T.; Dadey, B.

1978-01-01

Human peripheral blood T and B lymphocytes were separated by a method based on the stable rosette formation of T lymphocytes with neuraminidase-treated sheep erythrocytes, followed by centrifugation over a Ficoll-Hypaque gradient. Monocytes were isolated from the T-depleted B lymphocyte preparation by allowing the monocytes to ingest iron particles and by subsequent centrifugation over a Ficoll-Hypaque gradient. The T lymphocytes responded extremely well to PHA and very well to PWM, while the B lymphocytes were unresponsive to either PHA or PWM. However, when the B lymphocytes were cultured together with irradiated autologous or allogeneic T lymphocytes (1 : 1,1:2 or 1 : 4 ratio), both PHA and PWM became mitogenic to B lymphocytes. Irradiated T lymphocytes alone did not respond to either PHA or PWM, indicating that the 3 H-thymidine incorporation seen in the mixed-cell culture was due to the activation of unirradiated B lymphocytes. The B lymphocytes failed to respond to these phytomitogens in the presence of lower concentrations of irradiated T lymphocytes. The monocytes were found to be incapable of helping the B lymphocytes to respond to PHA or PWM. (author)

The effect of continuous low dose-rate gamma irradiation on cell population kinetics of lymphoid tissue

Science.gov (United States)

Foster, B. R.

1974-01-01

Cellular response and cell population kinetics were studied during lymphopoiesis in the thymus of the mouse under continuous gamma irradiation using autoradiographic techniques and specific labeling with tritiated thymidine. On the basis of tissue weights, it is concluded that the response of both the thymus and spleen to continuous low dose-rate irradiation is multiphasic. That is, alternating periods of steady state growth, followed by collapse, which in turn is followed by another period of homeostasis. Since there are two populations of lymphocytes - short lived and long-lived, it may be that different phases of steady state growth are mediated by different lymphocytes. The spleen is affected to a greater extent with shorter periods of steady-state growth than exhibited by the thymus.

Implementation of good manufacturing practices (GMP) on human blood irradiation

International Nuclear Information System (INIS)

Boghi, Claudio; Napolitano, Celia M.; Ferreira, Danilo C.; Rela, Paulo Roberto; Zarate, Herman S.

2007-01-01

The irradiation of human blood is used to avoid the TA-GVHD (transfusion-associated graft-versus-host-disease), a rare but devastating adverse effect of leukocytes present in blood components for a immuno-competent transfusion recipients. Usually this irradiation practice is performed to a physical elimination of lymphocytes. The implementation of the GMP will assure that the properly dose in a range of 25 Gy to 50 Gy will be delivered to the blood in the bag collected in a blood tissue bank. The studies to establish the GMP were developed under the guidelines of the standard ISO 11137 - Sterilization of health care products - Requirements for validation and routine control - Radiation sterilization. In this work, two dosimetric systems were used for dose mapping during the studies of irradiator qualification, loading pattern, irradiation process validation and auditing. The CaSO 4 : Dy dosimeter presented difficulties concerning to uncertainty on dose measurement, stability, trace ability and calibration system. The PMMA and gafchromic dosimetric systems have shown a better performance and were adopted on establishment of GMP procedures. The irradiation tests have been done using a Gammacell 220 Irradiator. The developed GMP can be adapted for different types of gamma irradiators, allowing to set up a quality assurance program for blood irradiation. (author)

Implementation of good manufacturing practices (GMP) on human blood irradiation

Energy Technology Data Exchange (ETDEWEB)

Boghi, Claudio; Napolitano, Celia M.; Ferreira, Danilo C.; Rela, Paulo Roberto [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)]. E-mails: cboghi@uol.com.br; cmnapoli@ipen.br; dancarde@ig.com.br; prela@ipen.br; Zarate, Herman S. [Comission Chilena de Energia Nuclear, Santiago (Chile)]. E-mail: hzarate@cchen.cl

2007-07-01

The irradiation of human blood is used to avoid the TA-GVHD (transfusion-associated graft-versus-host-disease), a rare but devastating adverse effect of leukocytes present in blood components for a immuno-competent transfusion recipients. Usually this irradiation practice is performed to a physical elimination of lymphocytes. The implementation of the GMP will assure that the properly dose in a range of 25 Gy to 50 Gy will be delivered to the blood in the bag collected in a blood tissue bank. The studies to establish the GMP were developed under the guidelines of the standard ISO 11137 - Sterilization of health care products - Requirements for validation and routine control - Radiation sterilization. In this work, two dosimetric systems were used for dose mapping during the studies of irradiator qualification, loading pattern, irradiation process validation and auditing. The CaSO{sub 4}: Dy dosimeter presented difficulties concerning to uncertainty on dose measurement, stability, trace ability and calibration system. The PMMA and gafchromic dosimetric systems have shown a better performance and were adopted on establishment of GMP procedures. The irradiation tests have been done using a Gammacell 220 Irradiator. The developed GMP can be adapted for different types of gamma irradiators, allowing to set up a quality assurance program for blood irradiation. (author)

Good manufacturing practices (GMP utilized on human blood irradiation process

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Cláudio Boghi

2008-01-01

Full Text Available Irradiation of human blood is used to avoid the TA-GVHD (transfusion-associated graft-versus-host-disease, a rare but devastating adverse effect of leukocytes present in blood components for immunocompetent transfusion recipients. Usually this irradiation practice is performed to a physical elimination of lymphocytes. The implementation of the GMP will assure that the properly dose in a range of 25Gy to 50Gy will be delivered to the blood in the bag collected in a blood tissue bank. The studies to establish the GMP were developed under the guidelines of the standard ISO 11137 - Sterilization of health care products - Requirements for validation and routine control - Radiation sterilization. In this work, two dosimetric systems were used for dose mapping during the studies of irradiator qualification, loading pattern, irradiation process validation and auditing. The CaSO4: Dy dosimeter presented difficulties concerning to uncertainty on dose measurement, stability, trace ability and calibration system. The PMMA and gafchromic dosimetric systems have shown a better performance and were adopted on establishment of GMP procedures. The irradiation tests have been done using a Gammacell 220 Irradiator. The developed GMP can be adapted for different types of gamma irradiators, allowing to set up a quality assurance program for blood irradiation.

DNA metabolism in peripheral lymphocytes of UV-B wholebody irradiated men

International Nuclear Information System (INIS)

Klein, W.; Kocsis, F.; Altmann, H.

1983-02-01

Healthy probands were UV-B irradiated and different times after the treatment blood was taken and lymphocytes were isolated. Semiconservative DNA-synthesis was enhanced after 4 in vivo expositions. DNA repair replication in lymphocytes after in vitro UV-C damage was initially increased in UV-B wholebody irradiated people. With nucleoidsedimentation DNA strand breaks after in vivo UV-B irradiation were detected. (Author) [de

Adherence of murine lymphocytes to high endothelial venules in vitro and its radiation effect

Energy Technology Data Exchange (ETDEWEB)

Lixin, Liu; Zijun, Mao; Zhiwei, Yin [Suzhou Medical Coll., JS (China). Dept. of Pathophysiology

1991-02-01

Using the assay of specific adhesion of lymphocytes to high endothelial venules (HEV) on cryostat sections of mesenteric lymph nodes (MLN), the effects of different doses (0, 1, 2, 4, 8 Gy) of {sup 60}Co {gamma}-ray irradiation of murine MLN lymphocytes in vitro on adhesion to normal HEV was observed. The results showed that in the irradiated murine MLN lymphocytes the ability to adhere to HEV of normal MLN was reduced. Statistical significance was revealed at 2, 4, 8 Gy irradiations. This results suggests that irradiation can inhibit the specific recognition and adhesion of lymphocytes to HEV to a certain extent.

Biological effects in lymphocytes irradiated with 99mTc: determination of the curve dose-response

International Nuclear Information System (INIS)

Oliveira, Romero Marcilio Barros Matias de

2002-08-01

Biological dosimetry estimates the absorbed dose taking into account changes in biological parameters. The most used biological indicator of an exposition to ionizing radiation is the quantification of chromosomal aberrations of lymphocytes from irradiated individuals. The curves of dose versus induced biological effects, obtained through bionalyses, are used in used in retrospective evaluations of the dose, mainly in the case of accidents. In this research, a simple model for electrons and photons transports was idealized to simulate the irradiation of lymphocytes with 99m Tc, representing a system used for irradiation of blood cells. The objective of the work was to establish a curve of dose versus frequencies of chromosomal aberrations in lymphocytes of human blood. For the irradiation of blood samples micro spheres of human serum of albumin (HSAM) market with 99m Tc were used, allowing the irradiation of blood with different administered activities of 99m Tc, making possible the study the cytogenetical effects as a function of such activities. The conditions of irradiation in vivo using HSAM spheres marked with 99m Tc were simulated with MCNP 4C (Monte Carlo N-Particle) code to obtain the dose-response curve. Soft tissue composition was employed to simulate blood tissue and the analyses of the curve of dose versus biological effect showed a linear quadratic response of the unstable chromosomal aberrations. As a result, the response of dose versus chromosomal aberrations of blood irradiation with 99m Tc was best fitted by the curve Y=(8,99 ±2,06) x 1- -4 + (1,24 ±0,62) x 10 -2 D + (5,67 ± 0,64) x 10 -2 D 2 . (author)

Effect of ionizing whole-body irradiation on the primary and secondary antibody reaction of cows to injection of human gamma globulin

International Nuclear Information System (INIS)

Koch, F.; Buchholz, I.; Mehlhorn, G.

1989-01-01

In 3 experiments 29 cows were exposed to whole-body irradiation, using 9 MeV X-rays of a linear accelerator, with doses of 1.50 and 2.00 Gy or 60 Co gamma rays with a dose of 2.75 Gy, as a midline dose. 2 weeks prior to irradiation the first immunization was applied using human gamma globulin. 4 or 5 weeks after irradiation a second immunization was carried out. The antibody titres were investigated. The irradiation failed to affect the antibody titres after the first immunization. After the second immunization the antibody titres of the irradiated animals remained diminished significantly (α = 0.05). This has been attributed to a damage of the memory cell pool. (author)

Cytogenetic determination of the effect of irradiation on in vitro lymphocyte transformation rates

International Nuclear Information System (INIS)

Lloyd, D.C.; Dolphin, G.W.; Purrott, R.J.

1976-01-01

The effect of x irradiation on the yield of transformed cells in 48-hr cultures has been studied in human peripheral-blood lymphocytes. Cytogenetic damage was used as a marker, aberration yields being obtained for mixed cultures prepared from equal numbers of normal and irradiated lymphocytes and from pure cultures of irradiated cells. Comparison of data from these two types of culture shows that the yield observed ranged from 90 percent of that expected at 50 rads to 11 percent at 700 rads. Poisson analysis demonstrated that for all doses, cells with high levels of structural damage were not selectively eliminated. The extent to which mitotic delay contributes to the reduction in numbers of transformed cells was examined by varying the time in cultures from 36 to 72 hr. The implication of this work in the field of radiation-dose estimation by chromosome-aberration analysis is discussed

Gamma irradiation induced ultrastructural changes in Paracoccidioides brasiliensis yeast cells

International Nuclear Information System (INIS)

Demicheli, Marina C.; Andrade, Antero S.R.; Goes, Alfredo Miranda

2007-01-01

Paracoccidioides brasiliensis is a thermally dimorphic fungus agent of paracoccidioidomycosis, a deep-seated systemic infection of humans with high prevalence in Latin America. Up to the moment no vaccine has still been reported. Ionizing radiation can be used to attenuate pathogens for vaccine development and we have successfully attenuated yeast cells of P. brasiliensis by gamma irradiation. The aim of the present study was to examine at ultrastructural level the effects of gamma irradiation attenuation on the morphology of P. brasiliensis yeast cells. P. brasiliensis (strain Pb-18) cultures were irradiated with a dose of 6.5 kGy. The irradiated cells were examined by scanning and also transmission electron microscopy. When examined two hours after the irradiation by scanning electron microscopy the 6.5 kGy irradiated cells presented deep folds or were collapsed. These lesions were reversible since examined 48 hours after irradiation the yeast have recovered the usual morphology. The transmission electron microscopy showed that the irradiated cells plasma membrane and cell wall were intact and preserved. Remarkable changes were found in the nucleus that was frequently in a very electrodense form. A extensive DNA fragmentation was produced by the gamma irradiation treatment. (author)

Effects of gamma irradiation on antioxidants of medicinal plants

International Nuclear Information System (INIS)

Jetawattana, Suwimol; Chaichantipyuth, Chaiyo

2003-06-01

The antioxidant effect of water extracts from irradiated medicinal plants on inhibition of lipid peroxidation in human plasma was examined. The results presented herein indicate that crude extracts from 29 kinds, 31 extracts, of medicinal plants, irradiated at 10 and 25 kilo gray. showed no significant change in inhibition of lipid peroxidation in plasma induced by gamma irradiation (p<0.05). It also found that extraction yields in some irradiated plants were increased

Effects of gamma irradiation on antioxidants of medicinal plants

Energy Technology Data Exchange (ETDEWEB)

Jetawattana, Suwimol [The irradiation research for agriculture program, Office of Atoms for Peace, BK (Thailand); Chaichantipyuth, Chaiyo [Faculty of Pharmacy, Chulalongkorn University, BK (Thailand)

2003-06-01

The antioxidant effect of water extracts from irradiated medicinal plants on inhibition of lipid peroxidation in human plasma was examined. The results presented herein indicate that crude extracts from 29 kinds, 31 extracts, of medicinal plants, irradiated at 10 and 25 kilo gray. showed no significant change in inhibition of lipid peroxidation in plasma induced by gamma irradiation (p<0.05). It also found that extraction yields in some irradiated plants were increased.

Dose Distribution of Gamma Irradiators

International Nuclear Information System (INIS)

Park, Seung Woo; Shin, Sang Hun; Son, Ki Hong; Lee, Chang Yeol; Kim, Kum Bae; Jung, Hai Jo; Ji, Young Hoon

2010-01-01

Gamma irradiator using Cs-137 have been widely utilized to the irradiation of cell, blood, and animal, and the dose measurement and education. The Gamma cell 3000 Elan (Nordion International, Kanata, Ontario, Canada) irradiator was installed in 2003 with Cs-137 and dose rate of 3.2 Gy/min. And the BioBeam 8000 (Gamma-Service Medical GmbH, Leipzig, Germany) irradiator was installed in 2008 with Cs-137 and dose rate of 3.5 Gy/min. Our purpose was to evaluate the practical dosimetric problems associated with inhomogeneous dose distribution within the irradiated volume in open air state using glass dosimeter and Gafchromic EBT film dosimeter for routine Gamma irradiator dosimetry applications at the KIRAMS and the measurements were compared with each other. In addition, an user guideline for useful utilization of the device based on practical dosimetry will be prepared. The measurement results of uniformity of delivered dose within the device showed variation more than 14% between middle point and the lowest position at central axis. Therefore, to maintain dose variation within 10%, the criteria of useful dose distribution, for research radiation effects, the irradiated specimen located at central axis of the container should be placed within 30 mm from top and bottom surface, respectively. In addition, for measurements using the film, the variations of dose distribution were more then 50% for the case of less than 10 second irradiation, mostly within 20% for the case of more than 20 second irradiation, respectively. Therefore, the irradiation experiments using the BioBeam 8000 irradiator are recommended to be used for specimen required at least more than 20 second irradiation time.

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)

The effect of in vitro irradiation on the responses of human lymphocytes to PHA, PPD and allogeneic cells

International Nuclear Information System (INIS)

Herva, E.; Kiviniitty, K.; Oulu Univ.

1975-01-01

The effect of X-ray, cobalt and 45 MeV electron irradiation on the responses of lymphocytes to PHA, PPD and allogeneic cells was studied using a semimicro lymphocyte culture technique. The responses to PPD and allogeneic cells were found to be more sensitive to irradiation than the response to PHA, even when the time factor was taken into account, i.e. the effect of irradiation was measured on the same day irrespective the type os stimulation. At the doses used, 500, 3,000 and 6,000 rd, there was no difference between the effects of the three types of radiation used. The possible explanations for the findings are discussed. (orig.) [de

Cytogenetic effects study of in vitro irradiation in peripheral blood lymphocytes of persons working with ionizing radiation

International Nuclear Information System (INIS)

Hadzhidekova, V.; Benova, D.; Bulanova, M.

1998-01-01

The genome radiosensitivity of persons working in the NPP 'Kozloduy', as well as controls are studied. An indicator of genome radiosensitivity is the chromosomal damage induced by in vitro irradiation. A cytogenetic analysis of peripheral blood lymphocytes before and after in vitro irradiation with a dose of 1.5 Gy gamma rays is carried out. The frequency of chromosomal aberrations and micronuclei before and after the irradiation is scored. In certain cases the technique of fluorescent in situ hybridization for recording stable chromosome rearrangements is applied. The data obtained show a decreased chromosome radiosensitivity in occupationally engaged persons as compared to low doses, over a long period of time, may induce the so called 'adaptive response' which makes cells more resistant of subsequent in vitro irradiation with a high dose (author)

The Effect of a Grape Seed Extract on Radiation-Induced DNA Damage in Human Lymphocytes

Science.gov (United States)

Dicu, Tiberius; Postescu, Ion D.; Foriş, Vasile; Brie, Ioana; Fischer-Fodor, Eva; Cernea, Valentin; Moldovan, Mircea; Cosma, Constantin

2009-05-01

Plant-derived antioxidants due to their phenolic compounds content are reported as potential candidates for reducing the levels of oxidative stress in living organisms. Grape seed extracts are very potent antioxidants and exhibit numerous interesting pharmacologic activities. Hydroethanolic (50/50, v/v) standardized extract was obtained from red grape seed (Vitis vinifera, variety Burgund Mare—BM). The total polyphenols content was evaluated by Folin-Ciocalteu procedure and expressed as μEq Gallic Acid/ml. The aim of this study was to evaluate the potential antioxidant effects of different concentrations of BM extract against 60Co γ-rays induced DNA damage in human lymphocytes. Samples of human lymphocytes were incubated with BM extract (12.5, 25.0 and 37.5 μEq GA/ml, respectively) administered at 30 minutes before in vitro irradiation with γ-rays (2 Gy). The DNA damage and repair in lymphocytes were evaluated using alkaline comet assay. Using the lesion score, the radiation-induced DNA damage was found to be significantly different (pextract (except the lymphocytes treated with 37.5 μEq GA/ml BM extract). DNA repair analyzed by incubating the irradiated cells at 37° C and 5% CO2 atmosphere for 2 h, indicated a significant difference (pextract, immediately and two hours after irradiation. These results suggest radioprotective effects after treatment with BM extract in human lymphocytes.

Varied effects of thoracic irradiation on peripheral lymphocyte subsets in lung cancer patients

International Nuclear Information System (INIS)

Nakayama, Yasuhiro; Makino, Shigeki; Fukuda, Yasuki; Min, Kyong-Yob; Ikemoto, Toshiyuki; Shimizu, Akira; Ohsawa, Nakaaki

1995-01-01

To investigate the influence of thoracic irradiation on immunological competence in patients with lung cancer, we examined the changes in peripheral blood lymphocyte subsets in 15 patients before and after radiation therapy by two-color flow cytometry techniques. After radiation therapy, the percentage and the absolute number of CD4+CD45RA+ cells (naive T cells) and CD56+and/orCD16+ cells (NK cells) decreased. The percentage of CD4+ human leukocyte antigen-DR(HLA-DR)+ cells (activated CD4T cells) and CD8+HLA-DR+ cells (activated CD8T cells) increased, although the absolute number did not change significantly. Naive T cells may be more selectively damaged than memory T cells by thoracic irradiation, through their recirculation behavior. The reduction of natural killer (NK) cells is disadvantageous for anti-tumor immunity. The percentage of HLA-DR positive T lymphocytes was significantly increased, and thus the possibility of HLA-DR enhancement by irradiation cannot be excluded. Therefore, thoracic irradiation has numerous varied effects on the immunological system of lung cancer patients. (author)

Heritability of Susceptibility to Ionizing Radiation-Induced Apoptosis of Human Lymphocyte Subpopulations

International Nuclear Information System (INIS)

Schmitz, Annette; Bayer, Jan; Dechamps, Nathalie; Goldin, Lynn; Thomas, Gilles

2007-01-01

Purpose: To evaluate the heritability of intrinsic radiosensitivity, the induction of apoptosis in lymphocyte subpopulations was determined on samples from related individuals belonging to large kindred families. Methods and Materials: Quiescent lymphocytes from 334 healthy individuals were gamma-irradiated in vitro. Apoptosis was determined 18 h after irradiation by eight-color flow cytometry. Radiosensitivity was quantified from dose-effect curves. Intrafamilial correlations and heritability were computed for 199 father-mother-offspring trios using the programs SOLAR (Sequential Oligogenic Linkage Analysis Routines) and SAGE (Statistical Analysis for Genetic Epidemiology). Segregation analyses were conducted using SAGE. Results: Marked differential susceptibility of naive and memory T lymphocytes was demonstrated. Also, although age and gender were significant covariates, their effects only accounted for a minor part of the inter-individual variation. Parent-offspring and sib-sib correlations were significant for the radiosensitivity of B cells, T4, and T8 and of effector memory T4 and T8 subpopulations. In the T4-effector memory subpopulation, the phenotype showed correlations most consistent with dominant or additive genetic effects, and the results of the segregation analysis were consistent with the contribution of a bi-allelic dominant locus. Conclusions: Heritability was demonstrated for the susceptibility to ionizing radiation-induced apoptosis of lymphocyte populations, and the segregation of the T4-effector memory radiosensitivity phenotype was consistent with a simple mendelian transmission model involving one major gene

Production of modified starches by gamma irradiation

International Nuclear Information System (INIS)

Kang, Il-Jun; Byun, Myung-Woo; Yook, Hong-Sun; Bae, Chun-Ho; Lee, Hyun-Soo; Kwon, Joong-Ho; Chung, Cha-Kwon

1999-01-01

As a new processing method for the production of modified starch, gamma irradiation and four kinds of inorganic peroxides were applied to commercial corn starch. The addition of inorganic peroxides without gamma irradiation or gamma irradiation without the addition of inorganic peroxides effectively decreased initial viscosity, but did not sufficiently keep viscosity stable. The combination of adding ammonium persulfate (APS) and gamma irradiation showed the lowest initial viscosity and the best stability out of the tested four kinds of inorganic peroxides. Among the tested mixing methods of APS, soaking was found to be more effective than dry blending or spraying. Therefore, the production of modified starch with low viscosity as well as with sufficient viscosity stability became feasible by the control of gamma irradiation dose levels and the amount of added APS to starch

Portable gamma-irradiator - a modified model

International Nuclear Information System (INIS)

Pandev, I.N.; Christova, M.G.; Stefanov, S.D.; Gentchev, N.V.; Bakardjiev, S.T.; Christov, C.D.; Genov, D.T.

1983-01-01

A new modification of a portable gamma-irradiator has been designed with a relatively large irradiation volume, good homogeneity of the gamma field, small overall dimension, light biological shielding, and simple mechanics. It is possible to irradiate materials in two cylindrical volumes (3 l and 6 l) with different dose rates. 137 Cs is used as a radiation source. Depending on application, the irradiator can be charged with various total activities up to 6.66 x 10 14 Bq (18 kCi). The dose rate can be also charged up to the maximum by different positions of the source element. The gamma-irradiator can be used for scientific studies and for industrial purposes. (author)

Drinking beer reduces radiation-induced chromosome aberrations in human lymphocytes

International Nuclear Information System (INIS)

Monobe, Manami

2002-01-01

We here investigated and reported the effects of beer drinking on radiation-induced chromosome aberrations in blood lymphocytes. Human blood that was collected either before or after drinking a 700 ml beer was in vitro irradiated with 200 kVp X rays or 50 keV/μm carbon ions. The relation between the radiation dose and the aberration frequencies (fragments and dicentrics) was significantly (P<0.05) lower for lymphocytes collected 3 h after beer drinking than those before drinking. Fitting the dose response to a linear quadratic model showed that the alpha term of carbon ions was significantly (P<0.05) decreased by beer drinking. A decrease of dicentric formation was detected as early as 0.5 h after beer drinking, and lasted not shorter than 4.5 h. The mitotic index of lymphocytes was higher after beer drinking than before, indicating that a division delay would not be responsible for the low aberrations induced by beer drinking. An in vitro treatment of normal lymphocytes with 0.1 M ethanol, which corresponded to a concentration of 6-times higher than the maximum ethanol concentration in the blood after beer drinking, reduced the dicentric formation caused by X-ray irradiation, but not by carbon-ion irradiation. The beer-induced reduction of dicentric formation was not affected by serum. It is concluded that beer could contain non-ethanol elements that reduce the chromosome damage of lymphocytes induced by high-LET radiation. (author)

Total lymphoid irradiation in multiple sclerosis: blood lymphocytes and clinical course

International Nuclear Information System (INIS)

Cook, S.D.; Devereux, C.; Troiano, R.; Zito, G.; Hafstein, M.; Lavenhar, M.; Hernandez, E.; Dowling, P.C.

1987-01-01

We have found a significant relationship between blood lymphocyte count and prognosis in 45 patients receiving either total lymphoid irradiation or sham irradiation for chronic progressive multiple sclerosis. Patients with sustained lymphocyte counts less than 900 mm-3 for prolonged periods after treatment showed less rapid progression over the ensuing 3 years than did patients with multiple sclerosis who had lymphocyte counts above this level (p less than 0.01). Our results suggest that a simple laboratory test, the absolute blood lymphocyte count, may serve as a valuable barometer for monitoring the amount of immunosuppressive therapy needed to prevent progression in patients with multiple sclerosis, and possibly other autoimmune diseases

Modelling a gamma irradiation process using the Monte Carlo method

International Nuclear Information System (INIS)

Soares, Gabriela A.; Pereira, Marcio T.

2011-01-01

In gamma irradiation service it is of great importance the evaluation of absorbed dose in order to guarantee the service quality. When physical structure and human resources are not available for performing dosimetry in each product irradiated, the appliance of mathematic models may be a solution. Through this, the prediction of the delivered dose in a specific product, irradiated in a specific position and during a certain period of time becomes possible, if validated with dosimetry tests. At the gamma irradiation facility of CDTN, equipped with a Cobalt-60 source, the Monte Carlo method was applied to perform simulations of products irradiations and the results were compared with Fricke dosimeters irradiated under the same conditions of the simulations. The first obtained results showed applicability of this method, with a linear relation between simulation and experimental results. (author)

Modelling a gamma irradiation process using the Monte Carlo method

Energy Technology Data Exchange (ETDEWEB)

Soares, Gabriela A.; Pereira, Marcio T., E-mail: gas@cdtn.br, E-mail: mtp@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

2011-07-01

In gamma irradiation service it is of great importance the evaluation of absorbed dose in order to guarantee the service quality. When physical structure and human resources are not available for performing dosimetry in each product irradiated, the appliance of mathematic models may be a solution. Through this, the prediction of the delivered dose in a specific product, irradiated in a specific position and during a certain period of time becomes possible, if validated with dosimetry tests. At the gamma irradiation facility of CDTN, equipped with a Cobalt-60 source, the Monte Carlo method was applied to perform simulations of products irradiations and the results were compared with Fricke dosimeters irradiated under the same conditions of the simulations. The first obtained results showed applicability of this method, with a linear relation between simulation and experimental results. (author)

Immunoglobulin production in human mixed lymphocyte cultures: implications for co-cultures of cells from patients and healthy donors

International Nuclear Information System (INIS)

Ruemke, H.C.; Terpstra, F.G.; Huis, B.; Out, T.A.; Zeijlemaker, W.P.

1982-01-01

When human peripheral blood lymphocytes (PBL) are cultured in the presence of irradiated allogeneic lymphocytes, the resulting mixed lymphocyte reaction (MLR) leads to the secretion into the supernatant of substantial amounts of IgM and IgG, derived from nonirradiated responder B lymphocytes. Our data indicate that stimulation to Ig production by responder B cells may result from different types of of interactions. First, B cells and monocytes among the irradiated stimulator cells activate T responder B cells to produce Ig; second, ''responder'' B cells activate irradiated ''stimulator'' T cells, leading to a ''helper'' signal, back to the responder B cells and leading to Ig production. The latter system is radiosensitive, because allogeneic T cells, irradiated at a dose of 4000 rad or more, failed to induce Ig production by responder B cells. In some combinations of human allogeneic lymphocytes, the co-culture of the cells leads to inhibition of Ig production, both in the presence and in the absence of PWM. Thus, co-culture of allogeneic cells may cause ''positive'' as well as ''negative'' allogeneic effects. The implications of these findings for the interpretation of co-cultures that are aimed at establishing defects in lymphocytes from patients with, for example, immunodeficiencies, who fail to produce Ig in the presence of PWM are discussed

T-dependence of human B lymphocyte proliferative response to mitogens.

Science.gov (United States)

Brochier, J; Samarut, C; Gueho, J P; Revillard, J P

1976-01-01

Human peripheral blood and tonsil lymphocytes were fractionated on anti-Ig-coated Sephadex columns or by centrifugation after rosetting with native sheep erythrocytes. Both methods allowed the recovery of B and T-enriched populations the purity of which was checked by fluorescein-labelled anti-Ig serum, E and EAC rosette formation, and heterologous antisera specific for B or T lymphocytes. The proliferative response of T cells to PHA, Con A, PWM, and ALS was not found different from that of unfractionated cells, whereas no response of the B cells could be observed to these mitogens providing that no contaminating T cells were present. Addition of T lymphocytes to these unresponsive B cells allowed them to respond to phytomitogens, but not to ALS. X-irradiated T cells could, to some extent, replace the diving T lymphocytes; no T-replacing factor could be found in cell-free supernatants from T cells, whether or not they had been activated by mitrogens. This model of B-T cooperation appears useful for studying the differentiation and maturation of human B lymphocytes.

Effect of in vivo γ-irradiation on the binding of wheat germ agglutinin on lymphocyte plasma membranes

International Nuclear Information System (INIS)

Moullier, P.; Daveloose, D.; Dubos, M.; Leterrier, F.; Hoebeke, J.

1986-01-01

Using quantitative fluorimetry with fluoresceinated wheat germ agglutinin, we have been able to investigate in vivo gamma radiation-induced damage at the outer membrane level of rat splenic lymphocytes, namely damage to the glucosidic moieties of membrane glycoproteins and glycolipids. This paper demonstrates that below an irradiation level of 1 gray (Gy), removal of sialic acid is the major feature leading to new exposed specific binding sites for wheat germ agglutinin, since this lectin is specific for sialic acid and N-acetyl-D-glucosamine. Our studies also suggest that above 1 Gy of irradiation more internal damage occurs, since we observed a striking decrease in wheat germ agglutinin binding sites. (orig.)

The Development of Gamma Irradiator Control System

International Nuclear Information System (INIS)

Mohd Zaid Hassan; Anwar Abdul Rahman; Azraf Azman; Mohd Rizal Mamat

2015-01-01

This paper presents the preliminary software development for the Gamma irradiator control system using commercial supervisory control and data acquisition (SCADA) software. The radiation dose analysis is the study of the relationship between the initial loading source activity (Curie) and concurrent activity in order to perform the irradiation process. The concurrent source activity calculation model is presented. The Human machine interface (HMI) has been developed by using Indusoft Web Studio to solve the mathematical calculation, task and process overview. (author)

Biometric indices of recirculating lymphocytes after acute and chronic gamma-irradiation

International Nuclear Information System (INIS)

Kalinin, E.V.

1978-01-01

The karyometry method was used to study the distribution of mature lymphocytes of lymphatic organs and peripheral blood among classes of nuclear volumes. Radiation injury was accompanied by a selection of populations of short-lived lymphocytes with very big nuclei the content of which was function of cumulative radiation dose. The number of small lymphocytes dependend on the phase of the radiation reaction

Computational model of gamma irradiation room at ININ

Science.gov (United States)

Rodríguez-Romo, Suemi; Patlan-Cardoso, Fernando; Ibáñez-Orozco, Oscar; Vergara Martínez, Francisco Javier

2018-03-01

In this paper, we present a model of the gamma irradiation room at the National Institute of Nuclear Research (ININ is its acronym in Spanish) in Mexico to improve the use of physics in dosimetry for human protection. We deal with air-filled ionization chambers and scientific computing made in house and framed in both the GEANT4 scheme and our analytical approach to characterize the irradiation room. This room is the only secondary dosimetry facility in Mexico. Our aim is to optimize its experimental designs, facilities, and industrial applications of physical radiation. The computational results provided by our model are supported by all the known experimental data regarding the performance of the ININ gamma irradiation room and allow us to predict the values of the main variables related to this fully enclosed space to within an acceptable margin of error.

EPR investigation of some gamma-irradiated medicines

International Nuclear Information System (INIS)

Aleksieva, Katerina; Yordanov, Nicola

2016-01-01

The results of EPR studies on three medical tablets – Galanthamine, Cytisine and Tribulus terrestris before and after gamma-irradiation are reported. Before irradiation Galanthamine and Cytisine tablets are EPR silent, whereas Tribulus terrestris show a broad singlet line with g factor 2.2084±0.002. The same spectrum is recorded after irradiation. After gamma-sterilization, however, Galanthamine and Cytisine tablets exhibit a typical EPR spectrum due to gamma induced free radicals in lactose used as an excipient. These stable free radicals can be used for identification of radiation processing for a long time after it. Key words: medical tablets, gamma-irradiation, EPR

DNA damage in human lymphocytes due to synergistic interaction between ionizing radiation and pesticide

International Nuclear Information System (INIS)

Kim, J. K.; Lee, K. H.; Lee, B. H.; Chun, K. J.

2001-01-01

Biological risks may arise from the possibility of the synergistic interaction between harmful factors such as ionizing radiation and pesticide. The effect of pesticide on radiation-induced DNA damage in human in human blood lymphocytes was evaluated by the single cell gel electrophoresis (SCGE) assay. The lymphocytes, with or without pretreatment of the pesticide, were exposed to 2.0 Gy of gamma ray. Significantly increased tail moment, which was a marker of DNA strand breaks in SCGE assay, showed an excellent dose-response relationship. The present study confirms that the pesticide has the cytotoxic effect on lymphocytes and that it interacts synergistically with ionizing radiationon DNA damage, as well

Gamma irradiators for radiation processing

International Nuclear Information System (INIS)

2006-01-01

Radiation technology is one of the most important fields which the IAEA supports and promotes, and has several programmes that facilitate its use in the developing Member States. In view of this mandate, this Booklet on 'Gamma Irradiators for Radiation Processing' is prepared which describes variety of gamma irradiators that can be used for radiation processing applications. It is intended to present description of general principles of design and operation of the gamma irradiators available currently for industrial use. It aims at providing information to industrial end users to familiarise them with the technology, with the hope that the information contained here would assist them in selecting the most optimum irradiator for their needs. Correct selection affects not only the ease of operation but also yields higher efficiency, and thus improved economy. The Booklet is also intended for promoting radiation processing in general to governments and general public

Effect of gamma irradiation on Korean traditional multicolored paintwork

Science.gov (United States)

Yoon, Minchul; Kim, Dae-Woon; Choi, Jong-il; Chung, Yong-Jae; Kang, Dai-Ill; Hoon Kim, Gwang; Son, Kwang-Tae; Park, Hae-Jun; Lee, Ju-Woon

2015-10-01

Gamma irradiation can destroy fungi and insects involved in the bio-deterioration of organic cultural heritages. However, this irradiation procedure can alter optical and structural properties of historical pigments used in wooden cultural heritage paintings. The crystal structure and color centers of these paintings must be maintained after application of the irradiation procedure. In this study, we investigated the effects of gamma irradiation on Korean traditional multicolored paintwork (Dancheong) for the preservation of wooden cultural heritages. The main pigments in Korean traditional wooden cultural heritages, Sukganju (Hematite; Fe2O3), Jangdan (Minium; Pb3O4), Whangyun (Crocoite; PbCrO4), and Jidang (Rutile; TiO2), were irradiated by gamma radiation at doses of 1, 5, and 20 kGy. After irradiation, changes in Commision Internationale d'Eclairage (CIE) color values (L*, a*, b*) were measured using the color difference meter, and their structural changes were analyzed using X-ray diffraction (XRD) analysis. The slightly change in less than 1 dE* unit by gamma irradiation was observed, and structural changes in the Dancheong were stable after exposure to 20 kGy gamma irradiation. In addition, gamma irradiation could be applied to painted wooden cultural properties from the Korean Temple. Based on the color values, gamma irradiation of 20 kGy did not affect the Dancheong and stability was maintained for five months. In addition, the fungicidal and insecticidal effect by less than 5 kGy gamma irradiation was conformed. Therefore, the optical and structural properties of Dancheong were maintained after gamma irradiation, which suggested that gamma irradiation can be used for the preservation of wooden cultural heritages painted with Dancheong.

In vitro evaluation of 213Bi-rituximab versus external gamma irradiation for the treatment of B-CLL patients: relative biological efficacy with respect to apoptosis induction and chromosomal damage

International Nuclear Information System (INIS)

Vandenbulcke, Katia; Lahorte, Christophe; Slegers, Guido; De Vos, Filip; Dierckx, Rudi A.; Offner, Fritz; Philippe, Jan; Apostolidis, Christos; Molinet, Roger; Nikula, Tuomo K.; Bacher, Klaus; De Gelder, Virginie; Vral, Anne; Thierens, Hubert

2003-01-01

External source radiotherapy and beta radioimmunotherapy (RIT) are effective treatments for lymphoid malignancies. The development of RIT with alpha emitters is attractive because of the high linear energy transfer (LET) and short path length, allowing higher tumour cell kill and lower toxicity to healthy tissues. We assessed the relative biological efficacy (RBE) of alpha RIT (in vitro) compared to external gamma irradiation with respect to induction of apoptosis in B chronic lymphocytic leukaemia (B-CLL) and induction of chromosomal damage in healthy donor B and T lymphocytes. The latter was measured by a micronucleus assay. 213 Bi was eluted from a 225 Ac generator and conjugated to CD20 antibody (rituximab) with CHX-A''-DTPA as a chelator. B-CLL cells from five patients were cultured for 24 h in RPMI/10% FCS while exposed to 213 Bi conjugated to CD20 antibody or after external 60 Co gamma irradiation. Binding assays were performed in samples of all patients to calculate the total absorbed dose. Apoptosis was scored by flow cytometric analyses of the cells stained with annexin V-FITC and 7-AAD. Apoptosis was expressed as % excess over spontaneous apoptosis in control. Full dose range experiments demonstrated 213 Bi-conjugated CD20 antibody to be more effective than equivalent doses of external gamma irradiation, but showed that similar plateau values were reached at 10 Gy. The RBE for induction of apoptosis in B-CLL was 2 between 1.5 and 7 Gy. The micronucleus yield in lymphocytes of healthy volunteers was measured to assess the late toxicity caused by induction of chromosomal instability. While gamma radiation induced a steady increase in micronucleus yields in B and T cells, the damage induced by 213 Bi was more dramatic, with RBE ranging from 5 to 2 between 0.1 Gy and 2 Gy respectively. In contrast to gamma irradiation, 213 Bi inhibited mitogen-stimulated mitosis almost completely at 2 Gy. In conclusion, high-LET targeted alpha particle exposure killed B

Cytogenetic damages in peripheral blood of monkey lymphocytes under simulation of cosmonauts irradiation.

Science.gov (United States)

Petrov, Vladislav; Ivanov, Alexandr; Barteneva, Svetlana; Snigiryeva, Galina; Shafirkin, Alexandr

Earth modeling of crewmember exposure should be performed for correct estimating radiation hazard during the flight. Such modeling was planned in a monkey experiment for investigating consequences of exposure to a man during an interplanetary flight. It should reflect a chronic impact of galactic cosmic rays and acute and fractional irradiation specified for solar cosmic rays and radiation belts respectively. Due to the difficulty of modeling a chronic impact with the help of a charged particles accelerator it can be used the gamma source. While irradiating big animal groups during a long-term period of time it is preferably to replace chronic irradiation by an equal fractional one. In this case the chosen characteristics of fractional irradiation should ensure the appearances of radiobiological consequences equal to the ones caused by the modeled chronic exposure. So for developing an exposure scheme in the monkey experiment (with Macaca -Rhesus) the model of the acting residual dose, that takes into account repair and recovery processes in the exposed body was used. The total dose value was in the limits from 2.32 Gy up to 3.5 Gy depending on the exposure character. The acting residual dose in all versions of exposure was 2.0 Gy for every monkey. While performing the experiment all the requirements of bioethics for the work with animals were observed. The objects of interest were genomic damages in lymphocytes of monkey's peripheral blood. The data about the CAF during the exposure and at various time moments after exposure particularly directly after the completion of chronicle and fractional irradiation were analyzed. CAF -dose of acute single gamma-irradiation in the range 0 -1.5Gy relationship (calibration curve) was defined in vitro. In addition the rate of the aberrant cells elimination within three months after the irradiation completion was estimated. On the basis of the obtained CAF data we performed verification of applicability of cytogenetic analysis

The secondary biogenic radiation of gamma-irradiated human blood

International Nuclear Information System (INIS)

Kuzin, A.M.; Surkenova, G.N.; Budagovskij, A.V.; Gudi, G.A.

1997-01-01

The sample of blood freshly taken from healthy men were gamma-irradiated with a dose of 10 Gy. It was shown that after the treatment the blood gained the capacity to emit secondary biogenic radiation. Emission lasted for some hours, passed through quartz-glass curette and was revealed by stimulating influence on biological detector (sprouting seeds)

Changes in lymphocyte subsets due to local irradiation of a portion of the maxilla in mice. A study of minor population lymphocytes

International Nuclear Information System (INIS)

Yamashita, Chiho; Satoh, Daigo; Yosue, Takashi

2001-01-01

In the present study we investigates the influence of the local irradiation of a portion of the maxilla on the numbers of lymphocyte subsets in peripheral blood and spleen, specifically minor population lymphocytes (γδT cells and NKT cells). Male C57BL/6 mice at 15 weeks of age were used for the experiments. In the irradiation group, a portion of the maxilla was exposed to X-ray (2.0 Gy/min, 10 Gy) and we analyzed lymphocytes using flow cytometry (anti-CD3, CD4, CD8, TCRαβ, TCRγδ and NK1.1 monoclonal antibodies), and compared the outcome to that obtained from the non-irradiation groups. The following results were obtained: In peripheral blood, CD4 + SP T cells, CD8 + SP T cells, αβ T cells, γδ T cells and NK cells decreased significantly on the first day and third day after irradiation. NKT cells decreased significantly on the third day after irradiation. In spleen, CD4 + SP T cells, CD8 + SP T cells, αβ T cells and γδ T cells decreased significantly on the first day after irradiation. NK cells and NKT cells did not change significantly after irradiation. The above results indicate that the changes in lymphocytes have a direct relationship to radiosensitivity, and the origin and distribution in lymphocyte subsets. (author)

Effect of gamma irradiation on Korean traditional multicolored paintwork

International Nuclear Information System (INIS)

Yoon, Minchul; Kim, Dae-Woon; Choi, Jong-il; Chung, Yong-Jae; Kang, Dai-Ill; Hoon Kim, Gwang; Son, Kwang-Tae; Park, Hae-Jun; Lee, Ju-Woon

2015-01-01

Gamma irradiation can destroy fungi and insects involved in the bio-deterioration of organic cultural heritages. However, this irradiation procedure can alter optical and structural properties of historical pigments used in wooden cultural heritage paintings. The crystal structure and color centers of these paintings must be maintained after application of the irradiation procedure. In this study, we investigated the effects of gamma irradiation on Korean traditional multicolored paintwork (Dancheong) for the preservation of wooden cultural heritages. The main pigments in Korean traditional wooden cultural heritages, Sukganju (Hematite; Fe 2 O 3 ), Jangdan (Minium; Pb 3 O 4 ), Whangyun (Crocoite; PbCrO 4 ), and Jidang (Rutile; TiO 2 ), were irradiated by gamma radiation at doses of 1, 5, and 20 kGy. After irradiation, changes in Commision Internationale d’Eclairage (CIE) color values (L*, a*, b*) were measured using the color difference meter, and their structural changes were analyzed using X-ray diffraction (XRD) analysis. The slightly change in less than 1 dE* unit by gamma irradiation was observed, and structural changes in the Dancheong were stable after exposure to 20 kGy gamma irradiation. In addition, gamma irradiation could be applied to painted wooden cultural properties from the Korean Temple. Based on the color values, gamma irradiation of 20 kGy did not affect the Dancheong and stability was maintained for five months. In addition, the fungicidal and insecticidal effect by less than 5 kGy gamma irradiation was conformed. Therefore, the optical and structural properties of Dancheong were maintained after gamma irradiation, which suggested that gamma irradiation can be used for the preservation of wooden cultural heritages painted with Dancheong. - Highlights: • Effects of gamma irradiation on the Dancheong were evaluated. • We confirmed that optical and structural properties of Dancheong were maintained. • Irradiation can contribute the

Kinetics of human lymphocyte division and chromosomal radiosensitivity

Energy Technology Data Exchange (ETDEWEB)

Bianchi, N O; Bianchi, M S; Larramendy, M [Instituto Multidisciplinario de Biologia Celular, La Plata (Argentinia)

1979-12-01

Human blood from normal donors was irradiated with 200 R during the G/sub 0/ phase, and the X-ray sensitivity of early and late dividing lymphocytes in culture was expressed as percentage of induced dicentrics. Cells in first or subsequent divisions were individualized by BrdU-Giemsa techniques. Lymphocytes in the first division at 40, 44 and 72 h after the start of culture had a lower sensitivity to radiation than lymphocytes making their first division at 48, 52 and 56 h. It was observed that: (a) the combination of radiation followed by BrdU did not increase the clastoyenic action of X-rays, (b)X-rays in the dose and duration used in our cultures did not increase the frequency of SCEs, and (c) minor changes in culture conditions probably influenced the frequency of SCEs.

Evaluation of gamma irradiation of teas

Energy Technology Data Exchange (ETDEWEB)

Gerolis, Luanai G.L.; Lameiras, Fernando S.; Menezes, Maria A.B.C.; Leal, Alexandre S., E-mail: luanaigraz@yahoo.com.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Krambrock, Klaus, E-mail: klaus@fisica.ufmg.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Dept. de Fisica. Lab. de Ressonancia Paramagnetica Eletronica

2013-07-01

There is a growing interest in the determination of non-essential traces elements in agroindustrial products. The continuous ingestion and accumulation in the organism of such elements, that may be toxic, can cause hazards to the human health in the long term. Reliable analytical techniques are necessary to monitor such products, including teas. In this work, the neutron activation technique is being employed to determine the trace elements in teas, due to its high sensibility and the possibility to perform a multi-elementary analysis. The gamma irradiation of teas is also being studied, because the shelf life can be extended and no chemical product is added to the teas. There is a concern related to the formation of free radicals in the teas, which is being accessed with electronic paramagnetic resonance. The results of the gamma irradiation up to 20 kGy of Camelia sinensis, Ilex paraguariensis, and Matricaria recutita are presented. (author)

Evaluation of gamma irradiation of teas

International Nuclear Information System (INIS)

Gerolis, Luanai G.L.; Lameiras, Fernando S.; Menezes, Maria A.B.C.; Leal, Alexandre S.; Krambrock, Klaus

2013-01-01

There is a growing interest in the determination of non-essential traces elements in agroindustrial products. The continuous ingestion and accumulation in the organism of such elements, that may be toxic, can cause hazards to the human health in the long term. Reliable analytical techniques are necessary to monitor such products, including teas. In this work, the neutron activation technique is being employed to determine the trace elements in teas, due to its high sensibility and the possibility to perform a multi-elementary analysis. The gamma irradiation of teas is also being studied, because the shelf life can be extended and no chemical product is added to the teas. There is a concern related to the formation of free radicals in the teas, which is being accessed with electronic paramagnetic resonance. The results of the gamma irradiation up to 20 kGy of Camelia sinensis, Ilex paraguariensis, and Matricaria recutita are presented. (author)

Gamma-irradiation of tomatoes

International Nuclear Information System (INIS)

Tencheva, S.; Todorov, S.

1975-01-01

The influence of gamma-ray on tomatoes picked in a pink-red ripening stage, good for consumption, is studied. For that purpose tomatoes of ''Pioneer 2'' variety packed in perforated 500 g plastic bags were irradiated on a gamma device (Cobalt-60) at a dose power of 1900 rad/min with doses 200 or 300 krad. Samples were stored after irradiation at room temperature (20 - 22sup(o)C). Microbiological studies demonstrated that 44 resp. 99.96 per cent of the initial number of microorganisms was destroyed after irradiation with 200 resp. 300 krad. The time required for the number of microorganisms to be restored was accordingly increased. Irradiation delayed tomato ripening by 4 to 6 days, demonstrable by the reduced content of the basic staining substances - carotene and licopine. Immediately after irradiation the ascorbic acid content was reduced by an average of 13 per cent. After 18 days the amount of ascorbic acid in irradiated tomatoes was increased to a higher than the starting level, this is attributed to reductone formation during irradiation. The elevated total sugar content shown to be invert sugar was due to further tomato ripening. (Ch.K.)

Post harvest changes gamma-irradiated banana Prata

International Nuclear Information System (INIS)

Vilas Boas, E.V. de; Chitarra, A.B.; Chitarra, M.I.F.

1996-01-01

The effect of the gamma-irradiation was evaluated at 0.25 and 0.50 kGy, on the development of peel coloration, CO 2 and ethylene evolution, conversion of starch to sugars, pulp-to-peel ratio, pectic solubilization and activities of enzymes of the cell wall, pectin methylesterase (PME), and polygalacturonase (PG), during maturation of 'Prata' bananas. The gamma-irradiation did not affect the normal colour development of the fruits. An increase in the ethylene peak and a decrease in the CO 2 peak was observed. The gamma-irradiation did not affect the degradation of starch, while a delay in soluble sugar accumulation was noted on the 6 and 7 colour grades. The fruits subjected to 0.25 kGy had the highest increase in the pulp-to-peel relation, beginning with colour grade 5, due to a possible stress effect of that dose. An increase of pectin solubilization was observed. Higher PME activities were exhibited by irradiated fruits, although the gamma-irradiation suppressed the PG activity throughout the maturation period. The gamma-irradiation did not extend the post-harvest life of 'Prata' bananas. (author) [pt

Cellular Stress to Low Gamma-ray Dose

International Nuclear Information System (INIS)

Manzanares-Acuna, E.; Vega-Carrillo, H. R.; Letechipia de Leon, C.; Guzman Enriquez, L. J.; Garcia-Talavera, M.

2004-01-01

The purpose of this study was to evaluate the effect of low gamma ray intensity upon Hsp 70 expression in human lymphocytes. the heat shock proteins (Hsp) family, are a group of proteins present in all living organism, therefore there are highly conserved and are related to adaptation and evolution. At cellular level these proteins acts as chaperones correcting denatured proteins. when a stress agent, such heavy metals, UV, heat, etc. is affecting a cell a response to this aggression is triggered through overexpression of Hsp. Several studies has been carried out in which the cellular effect are observed, mostly of these studies uses large doses, but very few studies are related with low doses. Blood of healthy volunteers was obtained and the lymphocytes were isolated by ficoll-histopaque gradient. Experimental lots were irradiated in a ''137Cs gamma-ray. Hsp70 expression was found since 0.5 cGy, indicating a threshold to very low doses of gamma rays. (Author) 27 refs

Gamma-ray spectroscopy on irradiated fuel rods

International Nuclear Information System (INIS)

Terremoto, Luis Antonio Albiac

2009-01-01

The recording of gamma-ray spectra along an irradiated fuel rod allows the fission products to be qualitatively and quantitatively examined. Among all nondestructive examinations performed on irradiated fuel rods by gamma-ray spectroscopy, the most comprehensive one is the average burnup measurement, which is quantitative. Moreover, burnup measurements by means of gamma-ray spectroscopy are less time-consuming and waste-generating than burnup measurements by radiochemical, destructive methods. This work presents the theoretical foundations and experimental techniques necessary to measure, using nondestructive gamma-ray spectroscopy, the average burnup of irradiated fuel rods in a laboratory equipped with hot cells. (author)

Manifestation of radiaton injury of human lymphocytes using PHA mitogenic stimulation in different culture systems

International Nuclear Information System (INIS)

Horky, J.

1986-01-01

The proliferative response of human lymphocytes to phytohemagglutinin in vitro is affected by X-irradiation. Dose-related changes in mitogenic stimulation of irradiated lymphocytes were compared for two culture systems - the cultivation of separated lymphocytes and the cultivation of whole blood. In the whole blood cultures, the proliferative activity of stimulated lyphocytes was markedly and reproducibly depressed by irradiation. An exponential curve could be fitted to the values of mitogenic response within a dose range from 0 to 2.5 Gy with high correlation. In a modified test where the mitogenic stimulus was given after a 24 h delay, depression in the response was even more pronounced. Radiosensitivity of human lymphocytes as determined by means of mitogenic stimulation in the whole blood cultures appears to be a characteristic individual feature. The mean D 37 value of the radiation-induced depression in mitogenic response in a group of 20 healthy donors was 2.5 Gy in the standard test and 2.0 Gy in the test with a delayed mitogenic stimulus. In contrast, the data obtained from separated lymphocyte cultures were characterized by a high degree of test-to-test variability and by much lower radiosensitivity. The possible mechanisms of these distinctive manifestations of the same primary radiation injury are discussed. (author) 3 tabs., 2 figs., 12 refs

Selective destruction of mouse islet beta cells by human T lymphocytes in a newly-established humanized type 1 diabetic model

Energy Technology Data Exchange (ETDEWEB)

Zhao, Yong, E-mail: yongzhao@uic.edu [Department of Medicine, University of Illinois at Chicago, Chicago, IL 60612 (United States); Guo, Chengshan; Hwang, David; Lin, Brian; Dingeldein, Michael; Mihailescu, Dan; Sam, Susan; Sidhwani, Seema [Department of Medicine, University of Illinois at Chicago, Chicago, IL 60612 (United States); Zhang, Yongkang [Department of Pharmacology, University of Illinois at Chicago, Chicago, IL 60612 (United States); Jain, Sumit [Department of Medicine, University of Illinois at Chicago, Chicago, IL 60612 (United States); Skidgel, Randal A. [Department of Pharmacology, University of Illinois at Chicago, Chicago, IL 60612 (United States); Prabhakar, Bellur S. [Department of Immunology and Microbiology, University of Illinois at Chicago, Chicago, IL 60612 (United States); Mazzone, Theodore [Department of Medicine, University of Illinois at Chicago, Chicago, IL 60612 (United States); Holterman, Mark J. [Department of Surgery, University of Illinois at Chicago, Chicago, IL 60612 (United States)

2010-09-03

Research highlights: {yields} Establish a human immune-mediated type 1 diabetic model in NOD-scid IL2r{gamma}{sup null} mice. {yields} Using the irradiated diabetic NOD mouse spleen mononuclear cells as trigger. {yields} The islet {beta} cells were selectively destroyed by infiltrated human T cells. {yields} The model can facilitate translational research to find a cure for type 1 diabetes. -- Abstract: Type 1 diabetes (T1D) is caused by a T cell-mediated autoimmune response that leads to the loss of insulin-producing {beta} cells. The optimal preclinical testing of promising therapies would be aided by a humanized immune-mediated T1D model. We develop this model in NOD-scid IL2r{gamma}{sup null} mice. The selective destruction of pancreatic islet {beta} cells was mediated by human T lymphocytes after an initial trigger was supplied by the injection of irradiated spleen mononuclear cells (SMC) from diabetic nonobese diabetic (NOD) mice. This resulted in severe insulitis, a marked loss of total {beta}-cell mass, and other related phenotypes of T1D. The migration of human T cells to pancreatic islets was controlled by the {beta} cell-produced highly conserved chemokine stromal cell-derived factor 1 (SDF-1) and its receptor C-X-C chemokine receptor (CXCR) 4, as demonstrated by in vivo blocking experiments using antibody to CXCR4. The specificity of humanized T cell-mediated immune responses against islet {beta} cells was generated by the local inflammatory microenvironment in pancreatic islets including human CD4{sup +} T cell infiltration and clonal expansion, and the mouse islet {beta}-cell-derived CD1d-mediated human iNKT activation. The selective destruction of mouse islet {beta} cells by a human T cell-mediated immune response in this humanized T1D model can mimic those observed in T1D patients. This model can provide a valuable tool for translational research into T1D.

Gamma irradiation of onions and garlic

International Nuclear Information System (INIS)

Baraldi, D.

1975-01-01

Technological and economic feasibility of gamma irradiation of onions and garlic on an industrial scale are studied. Statistical data on production, consumption, exportation and losses during storage are analyzed. Traditional methods of food preservation are reviewed and gamma irradiation techniques are presented as an alternative to sprout inhibition. Requirements for the irradiation of onions and garlic on a commercial scale including a cost benefit analysis are discussed. Some conclusions are formulated on licensing and prospects

Action of the poison of Apis mellifera bee and gamma radiation on bone marrow cells of Wistar rats and on lymphocytes of human peripheral blood

International Nuclear Information System (INIS)

Varanda, E.A.

1987-01-01

''In vivo'' and ''in vitro'' experiments are performed to determine the radioprotective action of the poison of Apis mellifera bees. The frequency of chromosome aberrations, induced by gamma radiation, is studied in two assays: ''in vivo'' in bone marrow cells from Wistar rats and ''in vitro'' in human peripheral blood lymphocyte cultures. The sister chromatid exchanges (SCE) are studied in the ''in vitro'' assays. (M.A.C.) [pt

Gamma scanning of the irradiated HANARO fuels

International Nuclear Information System (INIS)

Hong, Kwon Pyo; Lee, K. S.; Park, D. G.; Baik, S. Y.; Song, W. S.; Kim, T. Y.; Seo, C. K.

1997-02-01

To conform the burnup state of the fuels, we have transported the irradiated HANARO fuels from the reactor to IMEF (Irradiated Material Examination Facility), and executed gamma scanning for the fuels. By measuring the gamma-rays from the irradiated fuels we could see the features of the relative burnup distributions in the fuel bundles. All of 17 fuel bundles were taken in and out between HANARO and IMEF from March till August in 1996, and we carried out the related regulations. Longitudinal gamma scanning and angular gamma scanning are done for each fuel bundle without dismantlement of the bundles. (author). 5 tabs., 25 figs

Gamma irradiation devices

International Nuclear Information System (INIS)

Foeldiak, Gabor; Stenger, Vilmos.

1983-01-01

The main parameters and the preparation procedures of the gamma radiation sources frequently applied for irradiation purposes are discussed. In addition to 60 Co and 137 Cs sources also the nuclear power plants offer further opportunities: spent fuel elements and products of certain (n,γ) reactions can serve as irradiation sources. Laboratory scale equipments, pilot plant facilities for batch or continuous operation, continuous industrial irradiators and special multipurpose, mobile and panorama type facilities are reviewed including those in Canada, USA, India, the Soviet Union, Hungary, UK, Japan and Australia. For irradiator design the source geometry dependence of the spatial distribution of dose rates can be calculated. (V.N.)

Comparative effectiveness of gamma-rays and electron beams in food irradiation

International Nuclear Information System (INIS)

Hayashi, Toru

1991-01-01

Ionizing radiations which can be used for the treatment of foods are gamma-rays from Co-60 and Cs-137, accelerated electrons from a machine at an energy of 10 MeV or lower and X-rays from a machine at an energy of 5 MeV or lower. The Joint FAO/IAEA/WHO Expert Committee on the Wholesomeness of Irradiated Food held in 1980 concluded that the foods irradiated at overall average doses up to 10 kGy with the radiation listed above are wholesome for human consumption. While most of the commercial food irradiations are conducted with gamma-rays from Co-60, accelerated electrons are increasingly utilized for treating foods. An important difference between gamma-rays and accelerated electrons is the penetration capacity in materials. The penetration capacity of gamma-rays is much higher than that of accelerated electrons. Another important difference is the dose rate. The dose rates of gamma-rays from commercial Co-60 sources are 1-100 Gy/min, while those of electron beams from electron accelerators are 10 3 -10 6 Gy/s. Ideally a comparison of the effect of different types of ionizing radiation should be carried out at the same dose rate but this has been difficult due to the design of irradiators. It is very difficult to draw a definite conclusion on the difference in the effectiveness in food irradiation between gamma-rays and electron beams based on published data. This chapter deals with as many reports as possible on the comparative effectiveness of gamma-rays and electron beams and on the effect of dose rate on chemical reactions and living organisms, whether or not they demonstrate any dependency of the effect of irradiation on dose rate and type of radiation. (author)

A lymphoblastoid response of human foetal lymphocytes to ultraviolet-irradiated herpes simplex virus

International Nuclear Information System (INIS)

Westmoreland, D.

1980-01-01

Cultures of foetal lymphocytes were exposed to u.v.-irradiated herpes simplex virus (HSV). The cells responded with increased 6- 3 H-thymidine incorporation, the formation of clumps of enlarged lymphoblastoid cells and cell division. This response was first detected 3 to 4 days after exposure to virus material and was shown to be virus-dose dependent. The ability to stimulate foetal cells was considerably more u.v. resistant than infectivity. Two isolates of HSV type 2 (4663 and 37174), which had a high 'transforming' ability, produced large numbers of non-infectious particles (particle: infectivity ratios in excess of 10 4 ). The cells, which responded to u.v.-irradiated HSV with blastoid transformation, were associated with the non-E-rosetting (T-cell-depleted) subpopulation. (author)

Biological effects of tritiated water in low concentration of human lymphocyte chromosome

International Nuclear Information System (INIS)

Tanaka, K.; Kamada, N.; Sawaeda, S.

1992-01-01

This study was undertaken to investigate the dose-response relationship of tritiated water (HTO) for chromosome aberration in the human lymphocytes, at low dose in vitro exposure ranging from 0.1-1 Gy. The Relative Biological Effectiveness values of HTO with respect to 60 Co gamma ray at a dose rate of 2 cGy/min(15 mCi/ml), at low dose range for the induction of dicentric and centric ring chromosomes were 2.7 in lymphocytes. Also lymphocytes were chronically exposed to HTO for 67 to 80 hrs at different lower dose rates (0.5 and 0.02 cGy/min). There was a 77% decrease in the yields of dicentrics and centric rings, at the dose rate of 0.02cGy/min of HTO, presenting a clear dose rate effect of HTO. The RBE value of HTO relative to 137 Cs gamma ray was 2.0 at the dose rate of 0.02cGy/min(0.15mCi/ml). This suggests that a higher dose rate of HTO exposure has a higher risk and a decrease of RBE value at low dose rate. These results provide useful information for the assessment of health risks in humans specially exposed to low concentration of HTO. (author). 6 refs., 2 figs

RBE of thermal neutrons for induction of chromosome aberrations in human lymphocytes.

Science.gov (United States)

Schmid, E; Wagner, F M; Canella, L; Romm, H; Schmid, T E

2013-03-01

The induction of chromosome aberrations in human lymphocytes irradiated in vitro with slow neutrons was examined to assess the maximum low-dose RBE (RBE(M)) relative to (60)Co γ-rays. For the blood irradiations, cold neutron beam available at the prompt gamma activation analysis facility at the Munich research reactor FRM II was used. The given flux of cold neutrons can be converted into a thermally equivalent one. Since blood was taken from the same donor whose blood had been used for previous irradiation experiments using widely varying neutron energies, the greatest possible accuracy was available for such an estimation of the RBE(M) avoiding the inter-individual variations or differences in methodology usually associated with inter-laboratory comparisons. The magnitude of the coefficient α of the linear dose-response relationship (α = 0.400 ± 0.018 Gy(-1)) and the derived RBE(M) of 36.4 ± 13.3 obtained for the production of dicentrics by thermal neutrons confirm our earlier observations of a strong decrease in α and RBE(M) with decreasing neutron energy lower than 0.385 MeV (RBE(M) = 94.4 ± 38.9). The magnitude of the presently estimated RBE(M) of thermal neutrons is-with some restrictions-not significantly different to previously reported RBE(M) values of two laboratories.

Growth of Theileria annulata and Theileria parva macroschizont-infected bovine cells in immunodeficient mice: effect of irradiation and tumour load on lymphocyte subsets

Energy Technology Data Exchange (ETDEWEB)

Fell, A.H.; Preston, P.M. (Edinburgh Univ. (United Kingdom))

1992-07-01

Bovine cells infected with macroschizonts of the protozoan parasites Theileria annulata and Theileria parva formed solid tumours when injected into irradiated Balb/c and irradiated Balb/c nude mice. T. annulata tumours grew more vigorously than T. parva tumours, when initiated with similar doses of infected cells in mice exposed to the same doses of gamma-irradiation. In irradiated Balb/c mice, tumours of both species of parasites began to regress 2-3 weeks after injection of cells but grew without regression in irradiated Balb/c nude mice. Haemorrhage and necrosis of tumours, induced by macrophages and neutrophils, were seen in both mouse strains but were insufficient to cause regression in Balb/c nude mice. Theileria-infected bovine cells failed to establish in C57 beige mice, which lack functional natural killer (NK) cells. Flow cytometry, using monoclonal antibodies to murine leukocyte/lymphocyte antigens, showed that the radiation dose required to allow establishment of T. annulata tumours in Balb/c mice caused a severe depletion of splenic lymphocytes. B cells, helper T and cytotoxic T cells showed differing levels of susceptibility to irradiation. (Author).

Growth of Theileria annulata and Theileria parva macroschizont-infected bovine cells in immunodeficient mice: effect of irradiation and tumour load on lymphocyte subsets

International Nuclear Information System (INIS)

Fell, A.H.; Preston, P.M.

1992-01-01

Bovine cells infected with macroschizonts of the protozoan parasites Theileria annulata and Theileria parva formed solid tumours when injected into irradiated Balb/c and irradiated Balb/c nude mice. T. annulata tumours grew more vigorously than T. parva tumours, when initiated with similar doses of infected cells in mice exposed to the same doses of gamma-irradiation. In irradiated Balb/c mice, tumours of both species of parasites began to regress 2-3 weeks after injection of cells but grew without regression in irradiated Balb/c nude mice. Haemorrhage and necrosis of tumours, induced by macrophages and neutrophils, were seen in both mouse strains but were insufficient to cause regression in Balb/c nude mice. Theileria-infected bovine cells failed to establish in C57 beige mice, which lack functional natural killer (NK) cells. Flow cytometry, using monoclonal antibodies to murine leukocyte/lymphocyte antigens, showed that the radiation dose required to allow establishment of T. annulata tumours in Balb/c mice caused a severe depletion of splenic lymphocytes. B cells, helper T and cytotoxic T cells showed differing levels of susceptibility to irradiation. (Author)

Proliferative kinetics and chromosome damage in trisomy 21 lymphocyte cultures exposed to gamma-rays and bleomycin

International Nuclear Information System (INIS)

Morimoto, K.; Kaneko, T.; Iijima, K.; Koizumi, A.

1984-01-01

Lymphocytes from patients with Down's syndrome (trisomy 21) have been investigated for cell cycle kinetics, cell proliferation delays, and chromosomal aberrations after exposure to gamma-rays or bleomycin. Analysis by sister chromatid differential staining revealed that trisomy 21 lymphocytes started cell cycling about 5 hr earlier than did normal diploid lymphocytes after phytohemagglutinin stimulation as a whole, but that cycling trisomic and normal cells had the same mean cell cycle times. When exposed to gamma-rays or bleomycin in G0, trisomy 21 lymphocytes showed a 30% or, on average, 50% longer duration of cell turnover times, respectively, than normal cells; only bleomycin-treated trisomic cells had a biphasic dose-response. Frequencies of dicentrics and rings in first-division cells after gamma-ray or bleomycin exposure were twice as high in trisomic cells as in normal cells. The frequency of aberrations decreased by 50% (gamma-ray-exposed) or 65 to 85% (bleomycin-treated) through successive divisions; trisomic cells showed a more marked decline in aberration yields compared to normal cells after bleomycin treatment. These data support the idea that circulating lymphocytes in trisomy 21 patients have a shorter average life span or a younger average age

Ameliorating Effects of Bone Marrow Transplantation and Zinc Supplementation on Physiological and Immunological Changes in Gamma-Irradiated Rats

International Nuclear Information System (INIS)

Ashry, O.; Soliman, M.; Mahmoud, N.; Abd Elnaby, Y.

2015-01-01

Purpose: The present study was carried out to determine the prophylactic impact of zinc sulphate administration to irradiated rats treated with bone marrow transplantation (BMT) as indicated by the hematological and immunologic response as well as oxidative stress. Material and methods: Rats were injected orally with zinc sulphate, 10 mg/kg body wt, daily for 2 weeks before whole body 5 Gy gamma irradiation and intravenous injection of bone marrow cells, one hour post irradiation. Results: The results revealed a significant decrease in red blood cells (RBC), white blood cells (WBC), glutathione (GSH) and zinc superoxide dismutase (Zn/SOD), splenocyte count as well as bone marrow lymphocyte count and viability of irradiated rats. Regarding immunological data: tumor necrosis factor alpha (TNF– ) and interleukin 2 (IL–2) recorded a significant decrease while interleukin 6 (IL–6) and lipid peroxidation product (MDA) in the serum and spleen were conversely elevated. Zn supplementation before irradiation and BMT and showed significant decrease of serum and tissue MDA compared to the irradiated group. Lymphocytes, bone marrow viability percentage, splenocytes percentage, IL–2, IL–6 and GSH were significantly elevated compared to irradiated group. Conclusion: Protection with Zn, enforcing significant innate response, could trigger and augment adaptive immune response by BMT which suggests its use to protect against radiation hazards. (author)

Comparison of electron beam and gamma irradiation for the sterilization of allograft

International Nuclear Information System (INIS)

Jong il Choi; Nak Yun Sung; Hee Sub Lee; Jae Hun Kim; Myung Woo Byun; Ju Woon Lee

2008-01-01

Full text: For human use, it is necessary to sterilize the allograft in order to reduce the risk of infections and associated complications. In this study, we compared the effects of electron beam and gamma irradiation for the sterilization of the demineralized bone matrix (DBM) in a carboxymethylcellulose (CMC) carrier with regard to the physiological and osteoinductive properties. The CMC carrier was irradiated at the various doses. and the viscosity of the irradiated CMC was measured. The viscosity of the CMC irradiated with electron beam was higher than that with gamma ray. Also, the addition of vitamin C as the radical scavenger and irradiation at -70 degree C were shown to be effective in preventing the degradation of CMC by the irradiation. To investigate the effect of irradiation on the osteoinduction of DBM, alkaline phosphatase (ALP) activity with C2C12 cells was measured. The ALP activity of DBM in CMC was higher when irradiated with the electron beam compared with the gamma ray. The bone morphogenetic proteins (BMP) were extracted from DBM irradiated with electron beam and gamma ray, and it was found that the extraction efficiency of BMP was higher from DBM irradiated with the electron beam. This was reasoned for the higher APL activity of the electron beam irradiated DBM. With the advantages of electron beam such as short processing time, in-line processing, and low equipment cost, these results suggest that electron beam irradiation is recommendable for the sterilization of DBM allograft. (Author)

Effects of Acute Gamma Irradiation on Amaryllis Orange Bio gamma

International Nuclear Information System (INIS)

Sakinah Ariffin; Shakinah Salleh; Shuhaimi Shamsuddin; Suhaimi Musa; Affrida Abu Hassan

2016-01-01

Ornamental and landscaping plants have their own demand. Color variations, shape and flower shelf life are among the important value-added characters in improvement of new varieties of ornamental plants. Mutation induction using ionizing radiation is an alternative way for obtaining plant with desirable traits. Improvement of ornamental plant Amaryllis 'Orange Bio gamma' was carried out by exposing bulbs with gamma rays at dose 0, 10, 15, 20, 25, 30, 40 and 50 Gy using Bio Beam GM8000 gamma irradiation chamber at the Malaysian Nuclear Agency. Effect of radiation on the growth of bulbs was observed. Data on shoot and root length was recorded after 6 weeks. From the observation, the increasing dose has caused a reduction in shoot length and inhibited the root production. This paper will discuss the effects of acute gamma irradiation on the plant morphology. The result and observation obtained is useful for future work on lily improvement and will be included into Bio Beam GM8000 irradiation database. (author)

Mechanical and thermal properties of castor oil polyurethane bone cement after gamma irradiation

International Nuclear Information System (INIS)

Azevedo, E.C.; Chierice, G.O.; Claro Neto, S.; Lepiesnki, C.M.; Nascimento, E.M.

2009-01-01

Polyurethanes from castor oil are being employed as bone cement in medical applications. In this work the thermal and mechanical properties of gamma irradiated polyurethanes derivative from castor oil were investigated by instrumented indentation, thermogravimetry and scanning electron microscopy. A slightly increase in hardness is observed only for doses as high as 100 kGy. Thermal analysis indicates stability at human body temperature. The glass transition temperature has small changes after gamma irradiation. (author)

The induced expression of heat shock proteins as a part of the early cellular response to gamma radiation

International Nuclear Information System (INIS)

Stankova, K.; Ivanova, K.; Georgieva, R.; Rupova, I.; Boteva, R.

2008-01-01

A variety of stressful stimuli including gamma radiation can induce increase in the synthesis of heat shock proteins (Hsp). This family of molecular chaperones includes members with molecular masses ranging from 10 to 150 kDa and has been identified in all organisms from bacteria to humans. Hsp70 chaperones are very important. The present study aimed to characterize the radiation-induced changes in Hsp70 synthesis in human lymphocytes as a part of the early cellular response to gamma irradiation. The expression of Hsp70 was determined with Western blot and the radiation-induced apoptotic changes were registered by staining with fluorescent dyes. Part of the experiments were performed in the presence of the organic solvent DMSO. At low concentrations this reagent shows antioxidant activity and can reduce the level of the radiation-induced oxidant stress which determines the predominant biological effects of the ionizing radiation. Irradiation with 0.5 to 8 Gy caused statistically significant increase in the synthesis of Hsp70 which was strongest after irradiation with 4 Gy. In the range 0.5-2 Gy the enhancement of the radiation-induced synthesis of Hsp70 reached 60%. Our experimental results characterize changes in the Hsp70 synthesis after gamma irradiation as a part of the early cellular stress response in lymphocytes. (authors)

Differential androgenesis in gamma irradiated mice

Energy Technology Data Exchange (ETDEWEB)

Kim, Jihyang; Yoon, Yongdal [Hanyang Univ., Seoul (Korea, Republic of); Kim, Jin Kyu [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

2002-07-01

The Leydig cells of the testis account for at least 75% of the total testosterone produced in the normal adult male. Whereas the production of estrogen from androgen is catalyzed by aromatase cytochrome P450, which is found in many tissues, including gonad, brain, adipose tissue, bone, and heart. The gamma-irradiation causes the impairment of spermatogenesis and steroidogenesis in male mice. The present study was performed to analyze changes in testosterone concentrations and expression of steroidogenic enzyme of mice after whole body gamma-irradiation. Eight-week-old male ICR mice were irradiated with 6.5 or 10 Gy. At days 1, 2, 3, 4, and 5 after irradiation, testes were removed and processed for paraffin sections and isolation of mRNA. We calculated the gonad index from body and testis weight, and checked the testis volume. Hormonal analysis was performed by means of radioimmunoassay (RIA) in serum and intratesticular fluid. Semiquantitative reverse transcription polymerase chain reaction (RT-PCR) was used to evaluate the expression kinetics of the apoptotic gene and the cytochrome P450 aromatase gene after irradiation. In gamma-irradiated mice, the body weight reduced in comparison to that of the control group. Therefore, gonad indices increased. The testosterone concentrations in serum and intratesticular fluid were significantly reduced. RT- PCR data represented that the expression of Fas, Fas ligand, and aromatase cytochrome P450 showed the specific patterns against control groups. These results indicated that gamma- irradiation of adult mice induced the alteration of androgenesis and suggested that might counteract the spermatogenesis.

A Review on Microbial Mutagenesis through Gamma Irradiation for Agricultural Applications

International Nuclear Information System (INIS)

Hoe, P.C.K.; Khairuddin Abdul Rahim

2016-01-01

Gamma irradiation is widely used in sterilization and mutagenesis, especially for plant breeding and crop protection. Microbial mutagenesis through gamma irradiation is mainly applied in fermentation industry. In agriculture, gamma irradiation is mostly applied in crop improvement. Microbial mutagenesis is mainly applied against fungus and spore-forming bacteria, which are resistant to gamma irradiation. Response of microbes to gamma irradiation varies and depends on various factors. Review of previous works on gamma irradiation for microbial mutagenesis in agriculture may provide some information for the use of this method. The general view on gamma irradiation, its application, and mutagenesis are discussed in this paper. Further investigation on microbial mutagenesis should consider molecular changes, information on which is lacking in previous works. Moreover, studies on microbial mutagenesis are still lacking in Malaysia despite having several gamma irradiation facilities. Therefore, further studies on microbial mutagenesis should be conducted. (author)

Effect of proton and gamma irradiation on human lung carcinoma cells: Gene expression, cell cycle, cell death, epithelial–mesenchymal transition and cancer-stem cell trait as biological end points

Energy Technology Data Exchange (ETDEWEB)

Narang, Himanshi, E-mail: narangh@barc.gov.in [Radiation Biology and Health Sciences Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Kumar, Amit [Radiation Biology and Health Sciences Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Bhat, Nagesh [Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Pandey, Badri N.; Ghosh, Anu [Radiation Biology and Health Sciences Division, Bhabha Atomic Research Centre, Mumbai 400085 (India)

2015-10-15

Highlights: • Biological effectiveness of proton and gamma irradiation is compared in A549 cells. • Proton irradiation is two times more cytotoxic than gamma irradiation. • It alters ten times more number of early genes, as observed by microarray study. • It does not enhance cell migration, invasion and adhesion, unlike gamma irradiation. • It was more effective in reducing the percentage of cancer stem cell like cells. - Abstract: Proton beam therapy is a cutting edge modality over conventional gamma radiotherapy because of its physical dose deposition advantage. However, not much is known about its biological effects vis-a-vis gamma irradiation. Here we investigated the effect of proton- and gamma- irradiation on cell cycle, death, epithelial-mesenchymal transition (EMT) and “stemness” in human non-small cell lung carcinoma cells (A549). Proton beam (3 MeV) was two times more cytotoxic than gamma radiation and induced higher and longer cell cycle arrest. At equivalent doses, numbers of genes responsive to proton irradiation were ten times higher than those responsive to gamma irradiation. At equitoxic doses, the proton-irradiated cells had reduced cell adhesion and migration ability as compared to the gamma-irradiated cells. It was also more effective in reducing population of Cancer Stem Cell (CSC) like cells as revealed by aldehyde dehydrogenase activity and surface phenotyping by CD44{sup +}, a CSC marker. These results can have significant implications for proton therapy in the context of suppression of molecular and cellular processes that are fundamental to tumor expansion.

Influence of immunomodulators on the lymphokine secretion of irradiated lymphocytes

International Nuclear Information System (INIS)

Kowalczyk-Bronisz, S.H.

1986-01-01

Spleen lymphocytes derived from guinea pigs loose their ability to secrete lymphokines induced by Con A after treatment with irradiation (500 and 750 mC/kg). In the presence of the immunomodulators isoprinosine, levamisole and the thymosine-like factor TFX the lymphocytes are again capable of secreting lymphokines. After treatment with immunomodulators in dosages between 10 and 100 μg/ml the migration inhibition activity for macrophages and the chemotactic activity for polymorphonuclear granulocytes produced by lymphocytes were restored. (author)

In vitro evaluation of {sup 213}Bi-rituximab versus external gamma irradiation for the treatment of B-CLL patients: relative biological efficacy with respect to apoptosis induction and chromosomal damage

Energy Technology Data Exchange (ETDEWEB)

Vandenbulcke, Katia; Lahorte, Christophe; Slegers, Guido [Department of Radiopharmacy, Faculty of Pharmaceutical Sciences, Ghent University, Harelbekestraat 72, 9000, Gent (Belgium); De Vos, Filip; Dierckx, Rudi A. [Division of Nuclear Medicine, Ghent University Hospital (Belgium); Offner, Fritz [Department of Hematology, Ghent University Hospital (Belgium); Philippe, Jan [Department of Clinical Chemistry, Ghent University Hospital (Belgium); Apostolidis, Christos; Molinet, Roger; Nikula, Tuomo K. [European Commission, Joint Research Centre, Institute for Transuranium Elements, Karlsruhe (Germany); Bacher, Klaus; De Gelder, Virginie; Vral, Anne; Thierens, Hubert [Department of Anatomy, Embryology, Histology and Medical Physics, Ghent University (Belgium)

2003-10-01

External source radiotherapy and beta radioimmunotherapy (RIT) are effective treatments for lymphoid malignancies. The development of RIT with alpha emitters is attractive because of the high linear energy transfer (LET) and short path length, allowing higher tumour cell kill and lower toxicity to healthy tissues. We assessed the relative biological efficacy (RBE) of alpha RIT (in vitro) compared to external gamma irradiation with respect to induction of apoptosis in B chronic lymphocytic leukaemia (B-CLL) and induction of chromosomal damage in healthy donor B and T lymphocytes. The latter was measured by a micronucleus assay. {sup 213}Bi was eluted from a {sup 225}Ac generator and conjugated to CD20 antibody (rituximab) with CHX-A''-DTPA as a chelator. B-CLL cells from five patients were cultured for 24 h in RPMI/10% FCS while exposed to {sup 213}Bi conjugated to CD20 antibody or after external {sup 60}Co gamma irradiation. Binding assays were performed in samples of all patients to calculate the total absorbed dose. Apoptosis was scored by flow cytometric analyses of the cells stained with annexin V-FITC and 7-AAD. Apoptosis was expressed as % excess over spontaneous apoptosis in control. Full dose range experiments demonstrated {sup 213}Bi-conjugated CD20 antibody to be more effective than equivalent doses of external gamma irradiation, but showed that similar plateau values were reached at 10 Gy. The RBE for induction of apoptosis in B-CLL was 2 between 1.5 and 7 Gy. The micronucleus yield in lymphocytes of healthy volunteers was measured to assess the late toxicity caused by induction of chromosomal instability. While gamma radiation induced a steady increase in micronucleus yields in B and T cells, the damage induced by {sup 213}Bi was more dramatic, with RBE ranging from 5 to 2 between 0.1 Gy and 2 Gy respectively. In contrast to gamma irradiation, {sup 213}Bi inhibited mitogen-stimulated mitosis almost completely at 2 Gy. In conclusion, high

TRIGA out of core gamma irradiation facility

International Nuclear Information System (INIS)

Rant, J.; Pregl, G.

1988-01-01

A possibility to irradiate extended objects in a gamma field inside the shielding water tank and above the core of operating TRIGA Mark II Reactor has been investigated. The irradiation cask is shielded with Cd cover to filter out thermal neutrons. The dose rate of the gamma field strongly depends on the distance of the irradiation position above the core. At 25 cm above the core, the gamma dose rate is 2.2 Gy/s and epithermal neutron flux is ∼ 8.10 6 ncm -2 s -1 ∼ 3 as measured by TLD (CaF 2 : Mn) dosimeters and Au foils respectively. Tentative applications of the gamma irradiation facility are in the studies of radiation induced accelerated aging and within the Nuclear Power Plant Equipment Qualification Program (EQP). A complete characterization of the neutron spectrum and optimization of the 7 radiation field within the cask has still to be performed. (author)

Effect of gamma irradiation on storability of Syrian walnut

Energy Technology Data Exchange (ETDEWEB)

Al-Bachir, M [Atomic Energy Commission, Damascus (Syrian Arab Republic). Dept. of Radiation Technology

2001-12-01

Walnut fruits of Baladi variety were irradiated with 0, 0.5, 1.0, 1.5 and 2.0 kGy of gamma irradiation. The irradiated and unirradiated fruits were stored at room temperature (15 to 18 Centigrade) and at a relative humidity of 50 to 70%. Fungal load, proximate composition, chemical changes and sensory properties of nuts were evaluated immediately after irradiation, 6 and 12 months of storage. The results indicated that gamma irradiation reduced the fungal load. Used doses did not cause any significant change in proximate composition of walnuts. Immediately after irradiation, gamma irradiation increased total acidity and decreased iodine value and the volatile basic nitrogen (VBN). whereas, after 12 months of storage, gamma irradiation decreased total acidity and peroxide value and increased iodine value and (VBN). Immediately after irradiation no significant differences were observed between irradiated and non-irradiated samples in flavor and aroma. Whereas, after 12 months of storage higher doses (1.5 and 2.0 kGy) had a negative effect on sensory characteristics. (author)

Effect of gamma irradiation on storability of Syrian walnut

International Nuclear Information System (INIS)

Al-Bachir, M.

2002-01-01

Walnut fruits of Baladi variety were irradiated with 0, 0.5, 1.0, 1.5 and 2.0 kGy of gamma irradiation. The irradiated and unirradiated fruits were stored at room temperature (15 to 18 Centigrade) and at a relative humidity of 50 to 70%. Fungal load, proximate composition, chemical changes and sensory properties of nuts were evaluated immediately after irradiation, 6 and 12 months of storage. The results indicated that gamma irradiation reduced the fungal load. Used doses did not cause any significant change in proximate composition of walnuts. Immediately after irradiation, gamma irradiation increased total acidity and decreased iodine value and the volatile basic nitrogen (VBN). whereas, after 12 months of storage, gamma irradiation decreased total acidity and peroxide value and increased iodine value and (VBN). Immediately after irradiation no significant differences were observed between irradiated and non-irradiated samples in flavor and aroma. Whereas, after 12 months of storage higher doses (1.5 and 2.0 kGy) had a negative effect on sensory characteristics. (author)

Critical evaluation of gamma-irradiated serum used as feeder in the culture and demonstration of putative nanobacteria and calcifying nanoparticles.

Directory of Open Access Journals (Sweden)

Jan Martel

Full Text Available The culture and demonstration of putative nanobacteria (NB and calcifying nanoparticles (CNP from human and animal tissues has relied primarily on the use of a culture supplement consisting of FBS that had been gamma-irradiated at a dose of 30 kGy (gamma-FBS. The use of gamma-FBS is based on the assumption that this sterilized fluid has been rid entirely of any residual NB/CNP, while it continues to promote the slow growth in culture of NB/CNP from human/animal tissues. We show here that gamma-irradiation (5-50 kGy produces extensive dose-dependent serum protein breakdown as demonstrated through UV and visible light spectrophotometry, fluorometry, Fourier-transformed infrared spectroscopy, and gel electrophoresis. Yet, both gamma-FBS and gamma-irradiated human serum (gamma-HS produce NB/CNP in cell culture conditions that are morphologically and chemically indistinguishable from their normal serum counterparts. Contrary to earlier claims, gamma-FBS does not enhance the formation of NB/CNP from several human body fluids (saliva, urine, ascites, and synovial fluid tested. In the presence of additional precipitating ions, both gamma-irradiated serum (FBS and HS and gamma-irradiated proteins (albumin and fetuin-A retain the inherent dual NB inhibitory and seeding capabilities seen also with their untreated counterparts. By gel electrophoresis, the particles formed from both gamma-FBS and gamma-HS are seen to have assimilated into their scaffold the same smeared protein profiles found in the gamma-irradiated sera. However, their protein compositions as identified by proteomics are virtually identical to those seen with particles formed from untreated serum. Moreover, particles derived from human fluids and cultured in the presence of gamma-FBS contain proteins derived from both gamma-FBS and the human fluid under investigation-a confusing and unprecedented scenario indicating that these particles harbor proteins from both the host tissue and the FBS

Quality Properties of Cakes Containing Gamma-Irradiated Egg White

International Nuclear Information System (INIS)

Lee, J.W.; Seo, J.H.; Ahn, H.J; Byun, M.W; Kim, Y.H.; Choi, J.M.; Yook, H.S.

2003-01-01

As a research on the practical approaches of gamma irradiation for the reduction of egg allergy, cakes including gamma-irradiated egg white were manufactured, and rheological characteristics and sensory qualities of the cakes were evaluated. Egg white was separated from whole egg and then gamma-irradiated with the absorbed dose of 10 or 20 kGy

Physicochemical Properties of Gamma-Irradiated Corn Starch

International Nuclear Information System (INIS)

Lee, Y.J.; Lim, S.T.; Kim, S.Y.; Han, S.M.; Kim, H.M.; Kang, I.J.

2006-01-01

Structural modification of corn starch by gamma irradiation was evaluated for under dry conditions at varied intensities from 0 to 40 kGy. Under scanning electron microscopy, the granule shape of corn starch was not significantly affected by the irradiation up to 40 kGy. In addition, X-ray diffraction and melting patterns of the irradiated starches were similar to those of the native starch, indicating that crystalline regions in the starch granules were not changed by irradiation. However, the pattern of gel permeation column chromatography showed a significant increase in partial hydrolysis of gamma irradiated starch samples

Effect of gamma irradiation sterilization on the osteoinductive capacity of demineralized bone powder

International Nuclear Information System (INIS)

Babak Arjmand; Hamid Reza Aghayan; Mehdi Golestani; Farid Azmoudeh Ardalan

2008-01-01

Full text: Gamma irradiation is a well known method for secondary sterilization of bone allograft before clinical use to reduce the risk of infections and complications. The current study evaluated the effect of gamma irradiation on the osteoinductive capability of human demineralized bone powder using a rat model. Twenty rats received two separate implants consisting of 30 mg aseptically-harvested and 30 mg gamma irradiated demineralized bone powder. The implants from each group were placed into two separate muscle pouch in the paravertebral muscles of each rat. All 20 rats were euthanized after 4 weeks and each implantation site was removed with 0.5 cm normal tissue around the implant. Histological examination was done to determine the presence or absence of new bone, cartilage and bone marrow element. All except one of 20 aseptically-harvested demineralized bone powder sites histologically contained new bone elements (95%) and six (30%) of 20 gamma irradiated demineralized bone powder sites showed evidence of new bone elements. There was significant difference between two groups (p<0.05). The results of this study indicate that gamma irradiation reduces osteoinductive properties of demineralized bone powder. But because of its availability and low cost it is widely used for secondary sterilization of bone allografts. (Author)

Radiation effect and response of DNA synthesis in lymphocytes induced by low dose irradiation

International Nuclear Information System (INIS)

Zhao Yujie; Su Liaoyuan; Zou Huawei; Kong Xiangrong

1999-01-01

The ability of DNA synthesis in lymphocytes were measured by using 3 H-TdR incorporation method. This method was used to observe the damage of lymphocytes irradiated by several challenge doses (0.5-0.8 Gy) and adaptive response induced by previous low dose irradiation. The results show that DNA synthesis was inhibited by challenge dose of radiation and was adapted by previous 0.048 Gy irradiation

The Influence of N-acetylcysteine and Gender-Related Differences on the Radiosensitivity of Mouse Lymphocytes

International Nuclear Information System (INIS)

El-Shamy, E.; El-Kabany, H.

2012-01-01

The objective of the present study is to evaluate the possible efficiency of 200 mg/kg body weight N-acetylcysteine (NAC) on the radiosensitivity of mouse lymphocytes considering gender factor. The half of blood sample from mice was exposed to gamma-radiation (2 Gy). The time course of lymphocyte apotosis of irradiated samples was examined in vitro by flow cytometry and compared with lymphocytes from non-irradiated remaining half of samples. Kinetics of radiation-induced apoptosis was similar among groups, which peaked at 8 h. NAC protected irradiated lymphocytes in male mice. Lymphocytes from female mice were highly radiation resistant compared to males and the NAC provided no additional benefit at the doses used in this study. These results highlight that radiation-induced apoptosis is complex and is modified by the radio protector and gender.

Gemstone dedicated gamma irradiation development

Energy Technology Data Exchange (ETDEWEB)

Omi, Nelson M.; Rela, Paulo R. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)]. E-mails: nminoru@ipen.br; prela@ipen.br

2007-07-01

The gemstones gamma irradiation process to enhance the color is widely accepted for the jewelry industry. These gems are processed in conventional industrial gamma irradiation plant which are optimized for other purposes, using underwater irradiation devices with high rejection rate due to its poor dose uniformity. A new conception design, which states the working principles and manufacturing ways of the device, was developed in this work. The suggested device's design is based on the rotation of cylindrical baskets and their translation in circular paths inside and outside a cylindrical source rack as a planetary system. The device is meant to perform the irradiation in the bottom of the source storage pool, where the sources remain always shielded by the water layer. The irradiator matches the Category III IAEA classification. To verify the physical viability of the basic principle, tests with rotating cylindrical baskets were performed in the Multipurpose Irradiator constructed in the CTR, IPEN. Also, simulations using the CADGAMMA software, adapted to simulate underwater irradiations, were performed. With the definitive optimized irradiator, the irradiation quality will be enhanced with better dose control and the production costs will be significantly lower than market prices due to the intended treatment device's optimization. This work presents some optimization parameters and the expected performance of the irradiator. (author)

Decommissioning of an Irradiator MPX-{gamma} - 25M and a neutron Irradiator; Desmantelamiento de un irradiador tipo MPX-{gamma}-25M y de un irradiador de neutrones

Energy Technology Data Exchange (ETDEWEB)

Soguero, Dania; Guerra, Mercedes; Prieto, Enrique; Desdin, Luis, E-mail: sdania@ceaden.edu.cu [Centro de Aplicaciones Tecnologica y Desarrollo Nuclear (CEADEN), La Habana (Cuba)

2013-07-01

In this paper a technology is developed with its procedures in radiation protection to ensure the safety of the process of decommissioning of two irradiators. Both processes are described, the process of decommissioning of a neutron Irradiator 4. 44{center_dot}10{sup 11}Bq, employed in the vegetal radio mutagenesis, and disassembling of an installation of gamma irradiation of 3.33 * 10{sup 12} Bq, self-shielded of category I, model MPX - {gamma} - 25 M. The specific objectives are: a) identify aspects of the contractual assurance, of human and technical resources, b) to evaluate the radiological situation of the process and c) analyze the potential radiological extraordinary events in each of the steps of the process, ensuring the right answers. Evaluation of radiological successful events described can be considered as reference to address the process of disassembling of other similar irradiators.

[Induction of glutathione and activation of immune functions by low-dose, whole-body irradiation with gamma-rays].

Science.gov (United States)

Kojima, Shuji

2006-10-01

We first examined the relation between the induction of glutathione and immune functions in mice after low-dose gamma-ray irradiation. Thereafter, inhibition of tumor growth by radiation was confirmed in Ehrlich solid tumor (EST)-bearing mice. The total glutathione level of the splenocytes transiently increased soon after irradiation and reached a maximum at around 4 h postirradiation. Thereafter, the level reverted to the 0 h value by 24 h postirradiation. A significantly high splenocyte proliferative response was also recognized 4 h postirradiation. Natural killer (NK) activity was also increased significantly in a similar manner. The time at which the response reached the maximum coincided well with that of maximum total glutathione levels of the splenocytes in the gamma-ray-irradiated mice. Reduced glutathione exogenously added to splenocytes obtained from normal mice enhanced the proliferative response and NK activity in a dose-dependent manner. The inhibitory effects of radiation on tumor growth was then examined in EST-bearing mice. Repeated low-dose irradiation (0.5 Gy, four times, before and within an early time after inoculation) significantly delayed the tumor growth. Finally, the effect of single low-dose (0.5 Gy), whole-body gamma-ray irradiation on immune balance was examined to elucidate the mechanism underlying the antitumor immunity. The percentage of B cells in blood lymphocytes was selectively decreased after radiation, concomitant with an increase in that of the helper T cell population. The IFN-gamma level in splenocyte culture prepared from EST-bearing mice was significantly increased 48 h after radiation, although the level of IL-4 was unchanged. IL-12 secretion from macrophages was also enhanced by radiation. These results suggest that low-dose gamma-rays induce Th1 polarization and enhance the activities of tumoricidal effector cells, leading to an inhibition of tumor growth.

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)

Comparative study on disinfection potency of spore forming bacteria by electron-beam irradiation and gamma-ray irradiation

International Nuclear Information System (INIS)

Takizawa, Hironobu; Suzuki, Satoru; Suzuki, Tetsuya; Takama, Kozo; Hayashi, Toru; Yasumoto, Kyoden.

1990-01-01

Along with gamma-ray irradiation, electron-beam irradiation (EB) is a method to disinfect microorganisms which cause food decomposition and food-poisoning. The present study was undertaken to compare sterilization efficacy of EB and gamma-ray irradiation on bacterial spores and vegetative cells under various conditions. Spores of Bacillus pumilus, a marker strain for irradiation study, and Bacillus stearothermophilus known as a thermophilic bacteria were irradiated by electron-beam and gamma-ray separately at irradiation dose of 0 to 10 kGy on combination of wet/dry and aerobic/anaerobic conditions. Sterilization effect of irradiation on spores was evaluated by colony counting on agar plates. Results showed that both EB and gamma-ray irradiation gave sufficient sterilization effect on spores, and the sterilization effect increased exponentially with irradiation dose. The sterilization effect of gamma-ray irradiation was higher than that of EB in all cases. Higher disinfection effect was observed under aerobic condition. The present study suggests that oxygen supply in EB is more important than gamma-ray irradiation. No results suggesting that chlorine ion at 0.1 ppm (as available chlorine concentration) enhanced the sterilization efficacy of either EB or gamma-ray irradiation was obtained under any conditions examined. (author)

Comparative study on disinfection potency of spore forming bacteria by electron-beam irradiation and gamma-ray irradiation

Energy Technology Data Exchange (ETDEWEB)

Takizawa, Hironobu; Suzuki, Satoru; Suzuki, Tetsuya; Takama, Kozo [Hokkaido Univ., Hakodate (Japan). Faculty of Fisheries; Hayashi, Toru; Yasumoto, Kyoden

1990-10-01

Along with gamma-ray irradiation, electron-beam irradiation (EB) is a method to disinfect microorganisms which cause food decomposition and food-poisoning. The present study was undertaken to compare sterilization efficacy of EB and gamma-ray irradiation on bacterial spores and vegetative cells under various conditions. Spores of Bacillus pumilus, a marker strain for irradiation study, and Bacillus stearothermophilus known as a thermophilic bacteria were irradiated by electron-beam and gamma-ray separately at irradiation dose of 0 to 10 kGy on combination of wet/dry and aerobic/anaerobic conditions. Sterilization effect of irradiation on spores was evaluated by colony counting on agar plates. Results showed that both EB and gamma-ray irradiation gave sufficient sterilization effect on spores, and the sterilization effect increased exponentially with irradiation dose. The sterilization effect of gamma-ray irradiation was higher than that of EB in all cases. Higher disinfection effect was observed under aerobic condition. The present study suggests that oxygen supply in EB is more important than gamma-ray irradiation. No results suggesting that chlorine ion at 0.1 ppm (as available chlorine concentration) enhanced the sterilization efficacy of either EB or gamma-ray irradiation was obtained under any conditions examined. (author).

Subpopulations of lymphocytes and their bearing on the radiation dose-response of the human lymphocyte (cell survival, mitogenic stimulation and chromosome aberration frequency)

International Nuclear Information System (INIS)

Schwartz, J.L.

1979-01-01

To determine whether in the lymphocyte the frequency of chromosome aberrations might be influenced by a differential radiation response of the varying types of cells, as well as interactions among them, subpopulations were separated on the basis of differences in cell surface receptors. The subpopulations, namely, T and B lymphocytes and three T subsets, T-M, T-G, T-null, were found to differ in radiosensitivity as measured by survival in culture and mitotic index after PHA stimulation. All the populations studied are represented to varying degrees among the mitotic cells of unirradiated samples 48 hours after PHA stimulation. At increasing doses of 6 Co gamma rays (50, 100, 250, 500 rads), however, their proportions change both as a direct result of irradiation, such as cell killing, and as an indirect effect, such as the reduction in suppressor cell action

Bystander apoptosis in human cells mediated by irradiated blood plasma

Energy Technology Data Exchange (ETDEWEB)

Vinnikov, Volodymyr, E-mail: vlad.vinnikov@mail.ru [Grigoriev Institute for Medical Radiology of the National Academy of Medical Science of Ukraine (Ukraine); Lloyd, David; Finnon, Paul [Centre for Radiation, Chemical and Environmental Hazards of the Health Protection Agency of the United Kingdom (United Kingdom)

2012-03-01

Following exposure to high doses of ionizing radiation, due to an accident or during radiotherapy, bystander signalling poses a potential hazard to unirradiated cells and tissues. This process can be mediated by factors circulating in blood plasma. Thus, we assessed the ability of plasma taken from in vitro irradiated human blood to produce a direct cytotoxic effect, by inducing apoptosis in primary human peripheral blood mononuclear cells (PBM), which mainly comprised G{sub 0}-stage lymphocytes. Plasma was collected from healthy donors' blood irradiated in vitro to 0-40 Gy acute {gamma}-rays. Reporter PBM were separated from unirradiated blood with Histopaque and held in medium with the test plasma for 24 h at 37 Degree-Sign C. Additionally, plasma from in vitro irradiated and unirradiated blood was tested against PBM collected from blood given 4 Gy. Apoptosis in reporter PBM was measured by the Annexin V test using flow cytometry. Plasma collected from unirradiated and irradiated blood did not produce any apoptotic response above the control level in unirradiated reporter PBM. Surprisingly, plasma from irradiated blood caused a dose-dependent reduction of apoptosis in irradiated reporter PBM. The yields of radiation-induced cell death in irradiated reporter PBM (after subtracting the respective values in unirradiated reporter PBM) were 22.2 {+-} 1.8% in plasma-free cultures, 21.6 {+-} 1.1% in cultures treated with plasma from unirradiated blood, 20.2 {+-} 1.4% in cultures with plasma from blood given 2-4 Gy and 16.7 {+-} 3.2% in cultures with plasma from blood given 6-10 Gy. These results suggested that irradiated blood plasma did not cause a radiation-induced bystander cell-killing effect. Instead, a reduction of apoptosis in irradiated reporter cells cultured with irradiated blood plasma has implications concerning oncogenic risk from mutated cells surviving after high dose in vivo irradiation (e.g. radiotherapy) and requires further study.

Cell survival of human tumor cells compared with normal fibroblasts following 60Co gamma irradiation

International Nuclear Information System (INIS)

Lloyd, E.L.; Henning, C.B.; Reynolds, S.D.; Holmblad, G.L.; Trier, J.E.

1982-01-01

Three tumor cell lines, two of which were shown to be HeLa cells, were irradiated with 60 Co gamma irradiation, together with two cell cultures of normal human diploid fibroblasts. Cell survival was studied in three different experiments over a dose range of 2 to 14 gray. All the tumor cell lines showed a very wide shoulder in the dose response curves in contrast to the extremely narrow shoulder of the normal fibroblasts. In addition, the D/sub o/ values for the tumor cell lines were somewhat greater. These two characteristics of the dose response curves resulted in up to 2 orders of magnitude less sensitivity for cell inactivation of HeLa cells when compared with normal cells at high doses (10 gray). Because of these large differences, the extrapolation of results from the irradiation of HeLa cells concerning the mechanisms of normal cell killing should be interpreted with great caution

Biodosimetry of ionizing radiation by selective painting of prematurely condensed chromosomes in human lymphocytes

Science.gov (United States)

Durante, M.; George, K.; Yang, T. C.

1997-01-01

Painting of interphase chromosomes can be useful for biodosimetric purposes in particular cases such as radiation therapy, accidental exposure to very high radiation doses and exposure to densely ionizing radiation, for example during space missions. Biodosimetry of charged-particle radiation is analyzed in the present paper. Target cells were human peripheral blood lymphocytes irradiated in vitro with gamma rays, protons and iron ions. After exposure, lymphocytes were incubated for different times to allow repair of radiation-induced damage and then fused to mitotic hamster cells to promote premature condensation in the interphase chromosomes. Chromosome spreads were then hybridized with whole-chromosome DNA probes labeled with fluorescent stains. Dose-response curves for the induction of chromatin fragments shortly after exposure, as well as the kinetics of rejoining and misrejoining, were not markedly dependent on linear energy transfer. However, after exposure to heavy ions, more aberrations were scored in the interphase cells after incubation for repair than in metaphase samples harvested at the first postirradiation mitosis. On the other hand, no significant differences were observed in the two samples after exposure to sparsely ionizing radiation. These results suggest that interphase chromosome painting can be a useful tool for biodosimetry of particle radiation.

High activity gamma irradiators developed in Hungary

International Nuclear Information System (INIS)

Stenger, V.

1997-01-01

The development of high activity Gamma irradiators began in Hungary already in the early years of 60s. The very first designs were serving research in irradiation chemistry, radiation physics, food and agricultural research, radiation sterilization, plastic radiation chemistry, radiobiology, cancer therapy, personal and high dose dosimetry, following the international trends. Domestic and new international demands forced us to design and construct High Activity Gamma Irradiators: Multipurpose Pilot, Portable and Large scale bulk, Multipurpose Industrial scale types

Dicentric and ring chromosome yield in lymphocytes of in vitro irradiated blood of various donors

International Nuclear Information System (INIS)

Kubelka, D.; Horvat, D.; Svilicic, N.

1988-01-01

Results of in vitro irradiation of blood of nine human donors are presented. The blood irradiation doses were 0.1, 0.2, 0.5, 1, 2, and 3 Gy of X-ray exposure. The X-ray tube voltage was 250 kV. After irradiation, the standard 48-hours in vitro cultivation of lymphocytes was performed, with addition of BrdU, which enabled chromosome aberration analysis during the first in vitro division. Based on dicentric and ring yield, the dose-response curve has been generated for each donor. The tests on difference significance of obtained coefficients indicate there is no need for summary presentation of results. (author)

Detection of individual radiosensitivity by radiation–induced micronuclei in human peripheral blood lymphocytes and polymorphisms in DNA repair genes

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Staynova, A.; Hadjidekova, V.; Popova, L.; Hristova, R. [Radiation Genetics Laboratory, National Centre of Radiobology and Radiation Protection, Sofia (Bulgaria); Savov, A. [National Genetic Laboratory, University Hospital of Obstetrics and Gynecology, Sofia (Bulgaria)

2013-07-01

Aim: To investigate the association of two polymorphisms – in XRCC1 gene (Arg399Gln) and in APE1 gene (Asp148Glu) and the radiation induced frequency of micronuclei in human peripheral blood lymphocytes. Material and methods: Genomic DNA from 34 cancer patients and 52 controls were genotyped using PCR–RFLP technique. Micronucleus test (MNT) was performed on 15 cancer patients and 15 controls, before and after in vitro irradiation with 2Gy gamma rays. Results: The data showed that cancer patients had a significantly higher spontaneous frequency of cells with micronuclei than controls (P=0.009). No statistical difference was registered when comparing the mean frequency of cells with micronuclei after in vitro irradiation between these groups. Four subjects were selected as radiosensitive after applying cut–off of the mean frequency of radiation induced micronuclei. Three of them are carriers of the XRCC1 399Gln allele and two of them are carriers of the APE1 148Glu allele. (author)

Biomedical and biophysical research and calibration projects: radiobiology. Chromosomal aberrations in human lymphocytes - response to mixed neutron/photon exposures

International Nuclear Information System (INIS)

Slabbert, J.P.; Hough, J.H.; Jansen, S.

1991-01-01

Whether synergistic interaction damage is realized when lymphocytes are exposed to mixed high/low LET radiation fields, and if so, how well these effects can be predicted, was investigated. Whole-blood samples were exposed, at 37 degrees C, to neutrons, 60 Co gamma-rays and a mixture of 25% neutrons and 75% photons. The mixture was delivered both sequentially and simultaneously. A significant difference between the sequential and simultaneous irradiations was evident. Both mixed-field exposures yield aberration frequencies in excess of the sum predicted for individual irradiations. 5 refs., 2 figs., 1 tab

Practical design of gamma irradiation facility

International Nuclear Information System (INIS)

Sugimoto, Sen-ichi

1976-01-01

In this report, it is intended to describe mainly the multi-purpose irradiation facilities which carry out the consigned irradiation for the sterilization of medical apparatuses, which is most of the demand of gamma irradiation in Japan. Gamma irradiation criterion is summed up to that ''Apply the specified dose properly and uniformly to product cases and be economic.'' Though the establishment of the design standard for irradiation facilities is not easy and is not solve simply, the factors to be considered in the design are as follows: (1) mechanism safety, (2) multipurpose irradiation structure, (3) irradiation criteria and practice, (4) efficiency of radiation source utilization and related problems, and (5) economical merit. Irradiation facilities are generally itemized as follows: irradiation equipments, radiation source-storing facility, package carrier, radiation source-driving equipments, facilities for safety and operational management and others. Examples and their characteristics are reported for the facilities of Japan Radio-isotope Irradiation Cooperative Association and Radie Industries Ltd. Expenses for construction, processing and radiation sources are shown on the basis of a few references, and the cost trially calculated under a certain presumptive condition is given. (Wakatsuki, Y.)

Physicochemical properties of gamma-irradiated soybeans

International Nuclear Information System (INIS)

Lee, H.J.; Kim, J.O.; Yook, H.S.; Byun, M.W.

1996-01-01

Some physicochemical properties of gamma-irradiated soybeans (0-20 kCy) were investigated. Proximate components, fatty acid compositions and minerals of the soybeans irradiated at 2.5 - 20 kGy shrived no difference from the nonirradiated control. Irradiation doses above 10 kGy and long term storage caused decrease in extractable phenols and phytate content, whereas increases in acid value and organic acid content. The total amino acids content of the soybeans irradiated up to 10 kGy was not changed as compared with the nonirradiated control. Sulfur-containing amino acids, however, were changed by 10 and 20 kGy irradiaton. Gamma irradiation and long term storage caused minor changes in the color attributes of soybeans. Hunter's 'L' (lightness) and 'b' (yellowness) values were decreased whereas 'a' (redness) value was increased with increasing dose levels and the elapse of the storage period

Vanderbilt University Gamma Irradiation of Nano-modified Concrete (2017 Milestone Report)

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Deichert, Geoffrey G. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Linton, Kory D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Terrani, Kurt A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Selby, Aaron P. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Reches, Yonathan [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2017-08-01

This document outlines the irradiation of concrete specimens in the Gamma Irradiation Facility in the High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory (ORNL). Two gamma irradiation runs were performed in July of 2017 on 18 reference mortar bar specimens, 26 reference cement paste bar specimens, and 28 reference cement paste tab specimens to determine the dose and temperature response of the specimens in the gamma irradiation environment. Specimens from the first two gamma irradiations were surveyed and released to Vanderbilt University. The temperature and dose information obtained informs the test parameters of the final two gamma irradiations of nano-modified concrete planned for FY 2018.

Lymphocytes from wasted mice express enhanced spontaneous and {gamma}-ray-induced apoptosis

Energy Technology Data Exchange (ETDEWEB)

Woloschak, G.E. [Argonne National Lab., IL (United States)]|[Loyola Univ. Medical Center, Maywood, IL (United States); Chang-Liu, Chin-Mei [Argonne National Lab., IL (United States); Chung, Jen; Libertin, C.R. [Loyola Univ. Medical Center, Maywood, IL (United States)

1993-09-01

Mice bearing the autosomal recessive mutation wasted (wst/wst) display a disease pattern including faulty repair of DNA damage in lymphocytes after radiation exposure, neurologic abnormalities, and immunodeficiency. Many of the features of this mouse model have suggested a premature or increased spontaneous frequency of apoptosis in thymocytes; past work has shown an inability to establish cultured T cell lines, an abnormally high death rate of stimulated T cells in culture, and an increased sensitivity of T cells to the killing effects of ionizing radiations in wst/wst mice relative to controls. The experiments reported here were designed to examine splenic and thymic lymphocytes from wasted and control mice for signs of early apoptosis. Our results revealed enhanced expression of Rp-8 mRNA (associated with apoptosis) in thymic lymphocytes and reduced expression in splenic lymphocytes of wst/wst mice relative to controls; expression of Rp-2 and Td-30 mRNA (induced during apoptosis) were not detectable in spleen or thymus. Higher spontaneous DNA fragmentation was observed in wasted mice than in controls; however, {gamma}-ray-induced DNA fragmentation peaked at a lower dose and occurred to a greater extent in wasted mice relative to controls. These results provide evidence for high spontaneous and {gamma}-ray-induced apoptosis in T cells of wasted mice as a mechanism underlying the observed lymphocyte and DNA repair abnormalities.

Ultraviolet B irradiation induces changes in the distribution and release of arachidonic acid, dihomo-gamma-linolenic acid, and eicosapentaenoic acid in human keratinocytes in culture

International Nuclear Information System (INIS)

Punnonen, K.; Puustinen, T.; Jansen, C.T.

1987-01-01

There is increasing evidence that derivatives of 20-carbon polyunsaturated fatty acids, the eicosanoids, play an important role in the inflammatory responses of the human skin. To better understand the metabolic fate of fatty acids in the skin, the effect of ultraviolet B (UVB) irradiation (280-320 nm) on the distribution and release of 14 C-labeled arachidonic acid, dihomo-gamma-linolenic acid, and eicosapentaenoic acid in human keratinocytes in culture was investigated. Ultraviolet B irradiation induced the release of all three 14 C-labeled fatty acids from the phospholipids, especially from phosphatidylethanolamine, and this was accompanied by increased labeling of the nonphosphorus lipids. This finding suggests that UVB induces a significant liberation of eicosanoid precursor fatty acids from cellular phospholipids, but the liberated fatty acids are largely reincorporated into the nonphosphorus lipids. In conclusion, the present study suggests that not only arachidonic acid but also dihomo-gamma-linolenic acid, and eicosapentaenoic acid might be involved in the UVB irradiation-induced inflammatory reactions of human skin

Gamma irradiation treatment of secondary sewage effluent

International Nuclear Information System (INIS)

Vajdic, A.H.

The operation and monitoring of a pilot scale Co-60 gamma irradiation unit treating secondary sewage effluent is described. The disinfecting efficiency of the unit is compared to that of an experimental 'ideal' chlorination unit and to the plant chlorination process. A cost estimate for disinfection by gamma irradiation on a full plant scale is included. (author)

Inverse gamma ray dose rate effect in californium-252 RBE experiment with human T-1 cells irradiated in vitro

International Nuclear Information System (INIS)

Todd, P.; Feola, J.M.

1986-01-01

Metabolically deoxygenated suspensions of human T-1 cells were used to determine the RBE in hypoxia of low dose rate (LDR) Cf-252 radiation compared to LDR gamma radiation. Based upon the initial portion of the survival curves the RBE was 5.0 ± 1.0 for all components of the Cf-252 radiation and 7.1 ± 1.7 for the neutrons alone. An inverse dose rate effect was observed for LDR gamma radiation in which greater cell sensitivity was observed at lower dose rates and longer irradiation periods. It was demonstrated that there was little or no sublethal damage repair or cell progression during LDR at 21 deg C, and the observed decrease in cell survival probability with increasing irradiation time at a given dose was attributable to reoxygenation of the cell suspensions during the course of LDR exposures. (Auth.)

Participation of lymphocytes in hemopoiesis regeneration under local irradiation of the body

International Nuclear Information System (INIS)

Gol'dberg, E.D.; Dygaj, A.M.

1982-01-01

Lymphocyte participation in regulation of a pool of stem blood-producing cells using a model of local irradiation of bone marrow was studied. Right pelvic limb of BALB/c strain mice was exposed to local X-radiation at a dose of 7.0 Gy. During different periods after the irradiation the animals were killed and the total number of nucleus-containing cells in thymus, spleen, bone marrow from irradiated and screened femurs were counted. Smears of bone marrow were used to calculate myelogram. To study thymocyte effect on postradiation regeneration of hemopoesis, each of thymectomized mice were injected intravenously 4x10 7 viable thymocytes. Processes of the postradiation regeneration of hemopoesis were specially investigated in animals against the background of intraperitoneal injection of antithymocytic heterologous serum. The population of stem blood-producing cells of bone marrow was studied by the method of exogenic cloning in the body of syngenic recipient lethally irradiated (7.5 Gy). It is shown that during the period before active recovery of hemopoesis observed is the selective accumulation of lymphocytes of predominantly thymus origin only in irradiated blood-producing tissue. T lymphocytes stimulated colony-forming activity of bone marrow and accelerated the postradiation regeneration of hemopoesis

The effect of UV-light on DNA metabolism of lymphocytes during radiotherapy

International Nuclear Information System (INIS)

Klein, W.; Altmann, H.; Klein, H.; Alth, G.; Koren, H.

1980-02-01

The effects of gamma plus electron therapy and only gammatherapy, respectively, were investigated in lymphocytes of the peripheral blood of 10 patients with malignancies. The efficiency of DNA repair was tested by an irradiation of the cells with UV light beside radiotherapy. Using only gamma rays for therapy, the effects by UV light were not so pronounced than for using gamma plus electron therapy. (author)

Study of p53 protein expression levels from irradiated peripheral blood lymphocytes for biodosimetry

International Nuclear Information System (INIS)

Cavalcanti, M.B.; Fernandes, T.S.; Melo, J.A.; Neves, M.A.B.; Machado, C.G.F

2005-01-01

Biodosimetry can be defined as the investigation of radioinduced biological effects in order to correlate them with the absorbed dose. Scoring of unstable chromosomal aberrations and micronuclei, from in vitro irradiated peripheral blood lymphocytes, is commonly used for biodosimetry based on cytogenetic analysis. However, this method of analysis is time-consuming, which may represent a pitfall when fast investigation of a possible exposure to ionizing radiation (IR) is needed. The interaction of IR with the living cell can cause injuries in the DNA molecules. However, normal cells possess mechanisms of repair that are capable to correct those damages. During the repair process of the DNA various proteins are expressed. Among these proteins, p53 plays an important role. This protein is a transcription factor that helps in the maintenance of the genomic integrity. p53 protein is found into the cytoplasm in reduced concentrations and has a short average life. However, expression of p53 protein can be induced by DNA harmful radioinduced, which increases the concentration and the average life of this protein, making possible its detection. Thus, the correlation between the increasing of p53 expression and the irradiation may constitute a fast and reliable method of individual monitoring in cases of accidental or suspected exposures to IR. In this context, the objective of this research was to evaluate the p53 protein expression levels from lymphocytes of the human peripheral blood after in vitro irradiation. For this, samples of peripheral blood from healthy individuals were irradiated with known doses. Lymphocytes were separated on ficoll gradient by centrifugation and re-suspended at 1x 10 6 /mL in RPMI medium enriched with fetal calf serum. Hence, lymphocytes were incubated in 5% CO 2 at 37 deg C prior to the methodology of flow cytometry, using intranuclear antigens for the quantification of p53. In this report, the methodology performed and the results obtained

Study of p53 protein expression levels from irradiated peripheral blood lymphocytes for biodosimetry

Energy Technology Data Exchange (ETDEWEB)

Cavalcanti, M.B.; Fernandes, T.S. [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Energia Nuclear; Amaral, A. [Universite Paris XII (UPXII) (France); Melo, J.A. [Centro de Radioterapia de Pernambuco (CERAPE), PE (Brazil); Neves, M.A.B.; Machado, C.G.F, E-mail: maribrayner@yahoo.com.br [Fundacao de Hematologia e Hemoterapia de Pernambuco, PE (Brazil)

2005-07-01

Biodosimetry can be defined as the investigation of radioinduced biological effects in order to correlate them with the absorbed dose. Scoring of unstable chromosomal aberrations and micronuclei, from in vitro irradiated peripheral blood lymphocytes, is commonly used for biodosimetry based on cytogenetic analysis. However, this method of analysis is time-consuming, which may represent a pitfall when fast investigation of a possible exposure to ionizing radiation (IR) is needed. The interaction of IR with the living cell can cause injuries in the DNA molecules. However, normal cells possess mechanisms of repair that are capable to correct those damages. During the repair process of the DNA various proteins are expressed. Among these proteins, p53 plays an important role. This protein is a transcription factor that helps in the maintenance of the genomic integrity. p53 protein is found into the cytoplasm in reduced concentrations and has a short average life. However, expression of p53 protein can be induced by DNA harmful radioinduced, which increases the concentration and the average life of this protein, making possible its detection. Thus, the correlation between the increasing of p53 expression and the irradiation may constitute a fast and reliable method of individual monitoring in cases of accidental or suspected exposures to IR. In this context, the objective of this research was to evaluate the p53 protein expression levels from lymphocytes of the human peripheral blood after in vitro irradiation. For this, samples of peripheral blood from healthy individuals were irradiated with known doses. Lymphocytes were separated on ficoll gradient by centrifugation and re-suspended at 1x 10{sub 6}/mL in RPMI medium enriched with fetal calf serum. Hence, lymphocytes were incubated in 5% CO{sub 2} at 37 deg C prior to the methodology of flow cytometry, using intranuclear antigens for the quantification of p53. In this report, the methodology performed and the results

Caffeine degradation in water by gamma irradiation, ozonation and ozonation/gamma irradiation

Directory of Open Access Journals (Sweden)

Torun Murat

2014-03-01

Full Text Available Aqueous solutions of caffeine were treated with ozone and gamma irradiation. The amounts of remaining caffeine were determined after solid phase extraction as a function of absorbed dose and ozonation time. In addition to this, some important parameters such as inorganic ions, chemical oxygen demand (COD dissolved oxygen and total acidity changes were followed. Caffeine (50 ppm is found to be completely decomposed at 3.0 kGy and 1.2 kGy doses in the absence of H2O2 and in 1.20 mM H2O2 solutions, respectively. In the case of gamma irradiation after ozonation, 50 ppm caffeine was removed at 0.2 kGy when the solution was ozonized for 100 s at a rate of 10 g O3 h-1 in 400 mL 50 ppm paracetamol solution.

Symmetrical exchanges between chromosomes induced by irradiation of human lymphocytes with fast neutrons and detected by repeated fluorescence in situ hybridisation

International Nuclear Information System (INIS)

Lukasova, E.; Kozubek, S.; Ryznar, L.; Mareckova, A.; Bartova, E.; Kozubek, M.; Skalnikova, M.; Kroha, V.

1998-01-01

The frequency was studied of exchange aberrations between chromosomes no. 1, 2, 3, 4, 6, 8, 9, 11, 12, 14, 18, and 22 in the first postirradiation mitosis of human lymphocytes irradiated with various doses of neutrons of a mean energy of 7 MeV. Seven repeated hybridizations were carried out. Seven different images were obtained for each mitosis, in which two specific chromosomes were distinguished from the others by red and green fluorescence. The successive images were compared, whereby the frequencies of exchange aberrations between the visualized chromosomes were found. The results show a higher frequency of exchanges between chromosomes 14/8, 14/18, 14/3, 8/3, 8/1, and 8/18. No exchange aberrations occurred between the upper of the chromosomes mentioned and chromosomes 9, 22, 4, or 12. The results suggest that chromosomes 1, 3, 8, 14, and 18 are located in mutual vicinity in the interphase nuclei of lymphocytes. This vicinity seems to be one of the reasons for the spontaneous reciprocal exchanges between chromosome 14 and the remaining chromosomes mentioned (1, 3, 8, 18), characteristic for the malignancy of B-lymphocytes in various types of non-Hodgkin lymphomas

Bilateral lymphocytic alveolitis: a common reaction after unilateral thoracic irradiation

International Nuclear Information System (INIS)

Martin, C.; Romero, S.; Arriero, J.M.; Hernandez, L.; Sanchez-Paya, J.; Massuti, B.

1999-01-01

The main aim of the present study was to assess the early diagnostic value of bronchoalveolar lavage (BAL) in radiation-induced lung injury in patients with breast carcinoma. Twenty-six females receiving postoperative radiotherapy for breast cancer were evaluated before and 0, 15, 30, 60 , and 180 days after radiotherapy. History, physical examination, chest radiographs, and pulmonary function tests were obtained. BAL, including lymphocyte subsets analysis, was limited to the second evaluation after radiotherapy. A group of 21 healthy females were used as control. Findings after radiotherapy in asymptomatic patients were compared with findings in a group of patients with radiation pneumonitis. Irradiated patients showed a significantly (p<0.01) greater percentage (29.5±15.7%) of BAL lymphocytes than controls (6.2±3.3%). No statistical differences existed in BAL findings between the irradiated and unirradiated sides of the chest. Percentages of BAL lymphocytes did not differ significantly between patients who developed subsequent pneumonitis (24.5±13.5%) and those who did not develop pneumonitis (32.8±16.5%). Patients with pneumonitis at the time of BAL had significantly higher (p<0.05) alveolar CD4 subset cells (24.8±10.2%) than asymptomatic patients (15.2±8.9%). Maximal reductions in total lung capacity (p<0.01), and residual volume (p<0.05) occurred 60 days after irradiation. The early lymphocytic alveolitis induced by unilateral thoracic radiotherapy in most patients with breast cancer is always bilateral and does not predict the subsequent development of radiological evidence of pneumonitis. (au)

Bilateral lymphocytic alveolitis: a common reaction after unilateral thoracic irradiation

Energy Technology Data Exchange (ETDEWEB)

Martin, C.; Romero, S.; Arriero, J.M.; Hernandez, L. [Hospital General Universitario, Servicios de Neumologia, Alicante (Spain); Sanchez-Paya, J. [Hospital General Universitario, Epidemiologia, Alicante (Spain); Massuti, B. [Hospital General Universitario, Oncologia, Alicante (Spain)

1999-04-01

The main aim of the present study was to assess the early diagnostic value of bronchoalveolar lavage (BAL) in radiation-induced lung injury in patients with breast carcinoma. Twenty-six females receiving postoperative radiotherapy for breast cancer were evaluated before and 0, 15, 30, 60 , and 180 days after radiotherapy. History, physical examination, chest radiographs, and pulmonary function tests were obtained. BAL, including lymphocyte subsets analysis, was limited to the second evaluation after radiotherapy. A group of 21 healthy females were used as control. Findings after radiotherapy in asymptomatic patients were compared with findings in a group of patients with radiation pneumonitis. Irradiated patients showed a significantly (p<0.01) greater percentage (29.5{+-}15.7%) of BAL lymphocytes than controls (6.2{+-}3.3%). No statistical differences existed in BAL findings between the irradiated and unirradiated sides of the chest. Percentages of BAL lymphocytes did not differ significantly between patients who developed subsequent pneumonitis (24.5{+-}13.5%) and those who did not develop pneumonitis (32.8{+-}16.5%). Patients with pneumonitis at the time of BAL had significantly higher (p<0.05) alveolar CD4 subset cells (24.8{+-}10.2%) than asymptomatic patients (15.2{+-}8.9%). Maximal reductions in total lung capacity (p<0.01), and residual volume (p<0.05) occurred 60 days after irradiation. The early lymphocytic alveolitis induced by unilateral thoracic radiotherapy in most patients with breast cancer is always bilateral and does not predict the subsequent development of radiological evidence of pneumonitis. (au) 38 refs.

Chromosome aberrations of the peripheral lymphocytes in rabbits exposed to single and fractionated whole-body x-irradiations

International Nuclear Information System (INIS)

Tamura, Hiroaki; Sakurai, Masaharu; Sugahara, Tsutomu.

1978-01-01

The changes in the frequency of peripheral lymphocytes with chromosome aberrations were observed during or after irradiation of rabbits exposed to fractionated or single whole-body irradiations. In rabbits given daily fractionated whole-body irradiations the incidence of the aberrations showed a linear increase in the first week; however, the incidence decreased thereafter though exposures were repeated. The lymphocyte count tended to decrease as the number of irradiations increased. In rabbits exposed to a single dose of 250 R or 500 R the incidence of aberrations rapidly decreased over a period of 10 days following irradiation, and then showed a little change thereafter. The lymphocyte count in the peripheral blood reached a nadir 2 - 5 days after irradiation, and then started to increase gradually. It was speculated that there are two types of lymphocytes, long-lived and short-lived, in the peripheral blood of rabbits, both of which are PHA-committed. (auth.)

Lymphocyte as a biological dosimeter : a different approach

International Nuclear Information System (INIS)

Madhvanath, U.

1974-01-01

Chromosome aberration frequency as a measure of radiation exposure in human blood lymphocytes following a short term culture is well known and the technique is in use at several laboratories in the world to determine accidental exposures. Results of an entirely different approach to arrive at the exposure is presented. Time course of interphase death of human peripheral blood lymphocytes was followed for 6 days after exposure to cobalt-60 gamma radiation. Trypan blue dye exclusion method was used for scoring viable cells. Survival curves at 5 days post irradiation were exponential and had two components: an initial sensitive component representing a major sub-population of lymphocytes with a mean lethal dose (DO) of 75 rads and the other an apparently more resistant population with a Do of about 300 rads. The initial part of the survival curve which spans to about 100 rads reaching a survival level of 15 percent, can be used to read off the extent of exposure in accident cases. Although 60 percent of the initial lymphocytes survive in the unexposed control cultures, the method is sensitive to exposures of the order of 20 rads and reproducible results have been obtained. The response is independent of dose-rate from 65 rads/min to 65 rads/hour. Other aspects of the dosimetry system such as the neutron response, in vitro and in vivo correlation are discussed. (author)

Effect of caffeine posttreatment on X-ray-induced chromosomal aberrations in human blood lymphocytes in vitro

Energy Technology Data Exchange (ETDEWEB)

Natarajan, A T [Rijksuniversiteit Leiden (Netherlands). Dept. of Radiation Genetics and Chemical Mutagenesis; Cohen (J.A.) Inst. voor Radiopathologie en Stralenbescherming, Leiden (Netherlands)); Obe, G [Rijksuniversiteit Leiden (Netherlands). Dept. of Radiation Genetics and Chemical Mutagenesis; Cohen (J.A.) Inst. voor Radiopathologie en Stralenbescherming, Leiden (Netherlands); Freie Univ. Berlin (Germany, F.R.). Inst. fuer Genetik); Dulout, F N [Rijksuniversiteit Leiden (Netherlands). Dept. of Radiation Genetics and Chemical Mutagenesis; Instituto Multidisciplinario de Biologia Celular, La Plata (Argentinia))

1980-01-01

The potentiating effect of caffeine on X-ray-induced chromosomal aberrations in human blood lymphocytes has been investigated, with special reference to cell cycle stages (G0 and G2). Both quantitative and qualitative differences in the yield of chromosomal aberrations were detected in caffeine-posttreated cells, depending on the cell stage irradiated. The studies on caffeine potentiating effects on X-irradiated G0 lymphocytes from normal adults, newborns, Down syndrome patients, and an ataxia telangiectasia patient pointed to interindividual variations in the response to caffeine potentiation among normal probands and a very profound effect in ataxia cells.

Studies on adaptive response of lymphocyte transformation induced by low-dose irradiation

International Nuclear Information System (INIS)

Du Zeji; Su Liaoyuan; Tian Hailin; Zou Huawei

1995-10-01

Human peripheral blood lymphocytes stimulated by mitogen in vitro for 24 h were exposed to low-dose γ-ray irradiation (0.5∼4.0 cGy, adaptive dose). They showed an adaptive response to the inhibition of 3 H-TdR incorporation by subsequent higher acute doses of γ-ray (challenge dose). At the interval of 24 h between adaptive dose and challenge dose, the strongest adaptive response induced by low-dose irradiation was found. It is also found that the response induced by 1.0 cGy of adaptive dose was more obvious than that by other doses and that 3.0 Gy of challenge dose produced the strongest adaptive response. As the challenge doses increased, the adaptive response reduced. (2 figs., 2 tabs.)

Two-faces stationary irradiation method and dosimetric considerations for radiation processing at the multipurpose gamma irradiation facility / IPEN-CNEN

International Nuclear Information System (INIS)

Santos, Paulo S.; Vasquez, Pablo A.S.

2015-01-01

Over the last ten years, the Multipurpose Gamma Irradiation Facility of the Nuclear and Energy Research Institute - IPEN/CNEN located inside the Sao Paulo University campus has been providing services on radiation processing, especially for sterilization of health care and disposable medical products as well as support to research studies on modification of physical, chemical and biological properties of several materials. Placed at the same campus operates an extremely important radiopharmaceutical production facility when almost all disposable supplies used to produce medical products as the technetium-99m are continuously sterilized by gamma radiation. Many university biomedical research laboratories specially those working with equipment for cell cultures and vaccine production also make use of the gamma sterilization. Animal feed and shavings used by certified bioteries are routinely disinfected. Alternative underwater irradiation methods were developed to meet the demand of gemstone color enhancement. Human tissues including bone, skin, amniotic membranes, tendons, and cartilage belonging to National Banks are usually irradiated too. Different kind of polymers, hydrogels, foods as well native fruits, have been irradiated in this facility. Cultural heritage objects as books, paintings and furniture are disinfected routinely by gamma radiation. The success of the implementation of radiation processing in this facility is due to research and development of irradiation and dosimetry methods suitable for each condition. In this work are presented some considerations about the distribution dose and the two-faces stationary irradiation method developed and validated for this facility. (author)

Two-faces stationary irradiation method and dosimetric considerations for radiation processing at the multipurpose gamma irradiation facility / IPEN-CNEN

Energy Technology Data Exchange (ETDEWEB)

Santos, Paulo S.; Vasquez, Pablo A.S., E-mail: psantos@ipen.br, E-mail: pavsalva@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

2015-07-01

Over the last ten years, the Multipurpose Gamma Irradiation Facility of the Nuclear and Energy Research Institute - IPEN/CNEN located inside the Sao Paulo University campus has been providing services on radiation processing, especially for sterilization of health care and disposable medical products as well as support to research studies on modification of physical, chemical and biological properties of several materials. Placed at the same campus operates an extremely important radiopharmaceutical production facility when almost all disposable supplies used to produce medical products as the technetium-99m are continuously sterilized by gamma radiation. Many university biomedical research laboratories specially those working with equipment for cell cultures and vaccine production also make use of the gamma sterilization. Animal feed and shavings used by certified bioteries are routinely disinfected. Alternative underwater irradiation methods were developed to meet the demand of gemstone color enhancement. Human tissues including bone, skin, amniotic membranes, tendons, and cartilage belonging to National Banks are usually irradiated too. Different kind of polymers, hydrogels, foods as well native fruits, have been irradiated in this facility. Cultural heritage objects as books, paintings and furniture are disinfected routinely by gamma radiation. The success of the implementation of radiation processing in this facility is due to research and development of irradiation and dosimetry methods suitable for each condition. In this work are presented some considerations about the distribution dose and the two-faces stationary irradiation method developed and validated for this facility. (author)

Chromosomal aberrations in Cynomolgus peripheral lymphocytes during and after fractionated whole-body γ-irradiation

International Nuclear Information System (INIS)

Guedeney, G.; Malarbet, J.L.; Doloy, M.T.

1989-01-01

Cynomolgus monkeys (Macaca fascicularis) were exposed to fractionated whole-body γ-irradiation at high and low dose rates for 4 or 5 weeks. The time-dependence of chromosomal aberrations was studied in relation to the number of lymphocytes during irradiation and after exposure for periods of up to about 600 days for chromosomal aberrations and 200 days for lymphocyte counts. Additivity of the daily effects on the number of chromosomal aberrations was observed during the exposures. Immediately after the end of the exposures the number of chromosomal aberrations decreased to reach low values. The disappearance of chromosomal aberrations seemed to be related to recovery of the lymphocyte counts. The data presented here emphasize the different kinetic patterns of chromosomal aberrations after fractionated and acute irradiation. (author)

Radiosensitivity of different aged human lymphocytes following electron irradiation in vitro

International Nuclear Information System (INIS)

Joksic, G.; Nikolic, M.; Spasojevic-Tisma, V.

1997-01-01

Cytochalasin B-blocking micronucleus test and chromosomal aberration analysis were used in this study to estimate the yield of individual variability in radiation response of different aged human lymphocytes. Both analyses were performed in three groups of adults, aged 18-65 years, on two sampling times, following irradiation by therapeutical dose of 2 G in vitro. No statistically significant difference in the induced yield of exchange aberrations between individuals under consideration was found. The yield of total aberration data showed greater variability and was statistically significant in the oldest group against two other adult groups. Regarding to fixation times no statistically significant differences in the induced yield of chromosomal aberration (exchanges as well as total aberrations) were observed. The study has shown a slight increase in spontaneously occurring micronuclei with age. Almost equal mean number of radiation induced micronuclei was observed in the groups of adult aged 18-20 and 45-55 years. The highest mean number was observed in the oldest group. Evident variation in number of radiation induced micronuclei among individuals from the same age group was observed. The results of micronuclei assay for for all individuals under consideration show statistically significant difference in the yield of radiation-induced micronuclei regarding the second fixation time. This study has shown that cytochalasin-B blocking micronucleus test is more sensitive assay than chromosomal aberration analysis for the estimation of individual radiosensitivity. (author)

The yield of fission neutron-induced chromatid aberrations in G[sub 2]-stage human lymphocytes: effect of caffeine, hydroxyurea and cytosine arabinoside post-irradiation

Energy Technology Data Exchange (ETDEWEB)

Antoccia, A.; Tanzarella, C. (La Sapienza Univ., Rome (Italy)); Palitti, F. (Tuscia Univ., Viterbo (Italy) La Sapienza Univ., Rome (Italy)); Raggi, T. (Tuscia Univ., Viterbo (Italy)); Catena, C. (ENEA, Casaccia (Italy). Centro Ricerche Energia)

1992-11-01

To evaluate the influence of inhibitors of DNA synthesis/repair on the yield of chromosomal aberrations in the G[sub 2] phase of the cell cycle, whole-blood cultures of human lymphocytes were exposed to various doses of fission neutrons or X-rays and treated post-irradiation during the last 2.45 h before harvesting, with 5mM hydroxyurea (HU) and 0.05 mM cytosine arabinoside (ara-C). The presence of caffeine and HU strongly potentiated the yield of chromatid-type aberrations induced by both neutrons and X-rays. No potentiating effect, except at the highest dose of neutrons, was observed when irradiated cells were subsequently treated with ara-C. In addition, neutron-induced mitotic delay was shortened by treatment with caffeine, mainly within the first 2 h after irradiation. (Author).

Effect of gamma irradiation on the photoluminescence of porous silicon

Energy Technology Data Exchange (ETDEWEB)

Elistratova, M. A., E-mail: Marina.Elistratova@mail.ioffe.ru; Romanov, N. M. [Peter the Great St. Petersburg Polytechnic University (Russian Federation); Goryachev, D. N. [Russian Academy of Sciences, Ioffe Institute (Russian Federation); Zakharova, I. B. [Peter the Great St. Petersburg Polytechnic University (Russian Federation); Sreseli, O. M. [Russian Academy of Sciences, Ioffe Institute (Russian Federation)

2017-04-15

The effect of gamma irradiation on the luminescence properties of porous silicon produced by the electrochemical technique is studied. Changes in the photoluminescence intensity between irradiation doses and over a period of several days after the last irradiation are recorded. The quenching of photoluminescence at low irradiation doses and recovery after further irradiation are registered. It is found that porous silicon is strongly oxidized after gamma irradiation and the oxidation process continues for several days after irradiation. It is conceived that the change in the photoluminescence spectra and intensity of porous silicon after gamma irradiation is caused by a change in the passivation type of the porous surface: instead of hydrogen passivation, more stable oxygen passivation is observed. To stabilize the photoluminescence spectra of porous silicon, the use of fullerenes is proposed. No considerable changes in the photoluminescence spectra during irradiation and up to 18 days after irradiation are detected in a porous silicon sample with a thermally deposited fullerene layer. It is shown that porous silicon samples with a deposited C{sub 60} layer are stable to gamma irradiation and oxidation.

Tolerance of edible flowers to gamma irradiation

International Nuclear Information System (INIS)

Koike, Amanda C.R.; Araujo, Michel M.; Costa, Helbert S.F.; Almeida, Mariana C.; Villavicencio, Anna Lucia C.H.

2011-01-01

People have been eating flowers and using them in culinary creations for hundreds of years. Edible flowers are increasingly being used in meals as an ingredient in salads or garnish, entrees, drinks and desserts. The irradiation process is an alternative method that can be used in disinfestation of food and flowers, using doses that do not damage the product. The sensitivity of flowers to irradiation varies from species to species. In the present research was irradiated with doses up to 1 kGy some edible flowers to examine their physical tolerance to gamma-rays. Furthermore, high doses gamma irradiation causes petal withering, browning process and injury in edible flowers. (author)

Tolerance of edible flowers to gamma irradiation

Energy Technology Data Exchange (ETDEWEB)

Koike, Amanda C.R.; Araujo, Michel M.; Costa, Helbert S.F.; Almeida, Mariana C.; Villavicencio, Anna Lucia C.H., E-mail: ackoike@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP) Sao Paulo, SP (Brazil)

2011-07-01

People have been eating flowers and using them in culinary creations for hundreds of years. Edible flowers are increasingly being used in meals as an ingredient in salads or garnish, entrees, drinks and desserts. The irradiation process is an alternative method that can be used in disinfestation of food and flowers, using doses that do not damage the product. The sensitivity of flowers to irradiation varies from species to species. In the present research was irradiated with doses up to 1 kGy some edible flowers to examine their physical tolerance to gamma-rays. Furthermore, high doses gamma irradiation causes petal withering, browning process and injury in edible flowers. (author)

Glucose metabolism in gamma-irradiated rice seeds

International Nuclear Information System (INIS)

Inoue, M.; Hasegawa, H.; Hori, S.

1980-01-01

Gamma-irradiation of 30 kR in rice seeds caused marked inhibition in seedling growth, and prevented the release of reduced sugar during the period of 25 to 76hr after soaking. The C 6 /C 1 ratio following irradiation continued to decrease up to the 76th hour of soaking; the control's ratio tended to increase with comparable soaking time. The percentage recovery of 14 C in carbon dioxide from glucose -1- 14 C was lower in irradiated than in control seeds. These results indicate that gamma-irradiation reduces the participation of the pentose phosphate pathway in glucose catabolism during an early period of germination. (author)

Effect of irradiation on T-cell suppression of ELISA-determined Ig production by human blood B-cells in vitro

Energy Technology Data Exchange (ETDEWEB)

Wasserman, J; Stedingk, L.V. von; Biberfeld, G; Petrini, B; Blomgren, H; Baral, E [Central Microbiologcal Lab. of Stockholm County Council (Sweden)

1979-11-01

Human blood B-lymphocytes were co-cultured with in vitro irradiated allogeneic or autologous T-lymphocytes in the presence of pokeweed mitogen (PWM). The production of IgG, IgM and IgA, as assessed by the enzyme-linked immunosorbent assay (ELISA) was increased 2-7 times, as compared to values obtained with non-irradiated T-lymphocytes. It was suggested that the increase of Ig production was due to the selective radiosensitivity of T-lymphocytes with suppressor function. (author).

Gamma irradiation enhances biological activities of mulberry leaf extract

International Nuclear Information System (INIS)

Cho, Byoung-Ok; Che, Denis Nchang; Yin, Hong-Hua; Jang, Seon-Il

2017-01-01

The purpose of this study was to investigate the influence of irradiation on the anti-oxidative, anti-inflammatory and whitening effects of mulberry leaf extract. This was done by comparing the phenolic contents; 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging effects; 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonicacid) (ABTS) radical scavenging effects; in vitro tyrosinase inhibitory effects and the production of IL-6, TNF-α, PGE 2 , and NO in lipopolysaccharide-stimulated RAW264.7 macrophages and the production of IL-6 and TNF-α in phorbol 12-myristate 13-acetate plus calcium ionophore A23187-stimulated HMC-1 cells, respectively. The results showed that irradiated mulberry leaf extract possesses more anti-oxidant, anti-inflammatory, and tyrosinase inhibitory activities than their non-irradiated counterpart, probably due to increase in phenolic contents induced by gamma irradiation at dose of 10kGy. This research stresses on the importance of irradiation in functional foods. - Highlights: • Gamma-irradiated mulberry leaf extract enhanced in vitro antioxidant activities. • Gamma-irradiated mulberry leaf extract enhanced in vitro tyrosinase inhibitory effects. • Gamma-irradiated mulberry leaf extract treatment reduced the production of IL-6, TNF-α, PGE 2 , and NO.

Food irradiation: Gamma processing facilities

Energy Technology Data Exchange (ETDEWEB)

Kunstadt, P. [MDS Nordion International, 447 March Road. Kanata, Ontario, K2K148 (Canada)

1997-12-31

The number of products being radiation processed is constantly increasing and today include such diverse items as medical disposable, fruits and vegetables, bulk spices, meats, sea foods and waste effluents. Not only do the products differ but also many products, even those within the same groupings, require different minimum and maximum radiation doses. These variations create many different requirements in the irradiator design. The design of Cobalt-60 radiation processing facilities is well established for a number of commercial applications. Installations in over 40 countries, with some in operation since the early 1960s, are testimony to the fact that irradiator design, manufacture, installation and operation is a well established technology. However, in order to design gamma irradiators for the preservation of foods one must recognize those parameters typical to the food irradiation process as well as those systems and methods already well established in the food industry. This paper discusses the basic design concepts for gamma food irradiators. They are most efficient when designed to handle a limited product density range at an established dose. Safety of Cobalt-60 transport, safe facility operation principles and the effect of various processing parameters on economics, will also be discussed. (Author)

Food irradiation: Gamma processing facilities

Energy Technology Data Exchange (ETDEWEB)

Kunstadt, P [MDS Nordion International, 447 March Road. Kanata, Ontario, K2K148 (Canada)

1998-12-31

The number of products being radiation processed is constantly increasing and today include such diverse items as medical disposable, fruits and vegetables, bulk spices, meats, sea foods and waste effluents. Not only do the products differ but also many products, even those within the same groupings, require different minimum and maximum radiation doses. These variations create many different requirements in the irradiator design. The design of Cobalt-60 radiation processing facilities is well established for a number of commercial applications. Installations in over 40 countries, with some in operation since the early 1960s, are testimony to the fact that irradiator design, manufacture, installation and operation is a well established technology. However, in order to design gamma irradiators for the preservation of foods one must recognize those parameters typical to the food irradiation process as well as those systems and methods already well established in the food industry. This paper discusses the basic design concepts for gamma food irradiators. They are most efficient when designed to handle a limited product density range at an established dose. Safety of Cobalt-60 transport, safe facility operation principles and the effect of various processing parameters on economics, will also be discussed. (Author)

Food irradiation: Gamma processing facilities

International Nuclear Information System (INIS)

Kunstadt, P.

1997-01-01

The number of products being radiation processed is constantly increasing and today include such diverse items as medical disposable, fruits and vegetables, bulk spices, meats, sea foods and waste effluents. Not only do the products differ but also many products, even those within the same groupings, require different minimum and maximum radiation doses. These variations create many different requirements in the irradiator design. The design of Cobalt-60 radiation processing facilities is well established for a number of commercial applications. Installations in over 40 countries, with some in operation since the early 1960s, are testimony to the fact that irradiator design, manufacture, installation and operation is a well established technology. However, in order to design gamma irradiators for the preservation of foods one must recognize those parameters typical to the food irradiation process as well as those systems and methods already well established in the food industry. This paper discusses the basic design concepts for gamma food irradiators. They are most efficient when designed to handle a limited product density range at an established dose. Safety of Cobalt-60 transport, safe facility operation principles and the effect of various processing parameters on economics, will also be discussed. (Author)

Polyherbal EMSA ERITIN Promotes Erythroid Lineages and Lymphocyte Migration in Irradiated Mice

Directory of Open Access Journals (Sweden)

Ibrahim Mansur

2016-01-01

Full Text Available Radiotherapy is commonly used to kill malignant cells, but it can significantly deplete hematopoietic and splenic erythroblasts. Radioprotective agents are therefore very important in clinical radiotherapy. We examined the effect of poly-herbal EMSA ERITIN on immunological responses when administered to sublethally irradiated mice with the aim of highlighting promotes erythroid lineages and lymphocytes migration in irradiated mice with the parameter are TER119+CD123+in bone marrow and SDF-1 in bone marrow and spleen organ. Normal BALB/c mice were sublethally irradiated with 600 rad. EMSA ERITIN was administered orally at different doses:(1.04, 3.125 and 9.375 mg/g body weight for 15 days. On day 16 erythroid lineages (TER-119+CD123+ were observed in bone marrow and lymphocytes migration by the production of SDF-1 in spleen and bone marrow. Lymphocytes migration was indicated by the production of SDF-1 in spleen and bone marrow using flow cytometry analysis. EMSA ERITIN increased the generation of erythroid lineage cells marked by TER119+CD123+ and promoted lymphocyte migration by increasing SDF-1 production in bone marrow and spleen. EMSA ERITIN appears to be a powerful medicinal herb with potential as a food supplement to normalize homeostasis and erythropoiesis after radiation.

Improvement of rice starch by gamma irradiation

International Nuclear Information System (INIS)

Duan Zhiying; Wu Dianxing; Shen Shengquan; Han Juanying; Xia Yingwu

2003-01-01

Three types of rice cultivars, Indica, Japonica and hybrid rice, with similar intermediate apparent amylose content (AAC) as well as early Indica rice cultivars with different amounts of AAC were selected for studying the effects of gamma irradiation on starch viscosity, physico-chemical properties and starch granule structure. Four major parameters of RVA profile, peak viscosity (PKV), hot paste viscosity (HPV), cool paste viscosity (CPV), setback viscosity (SBV) and consistence viscosity (CSV) were considerably decreased with increasing dose levels. Gamma irradiation reduced the amylose contents in the cultivars with low AAC, intermediate AAC, and glutinous rice, but had no effects on the high AAC cultivar. No visible changes in alkali spreading value (ASV) were detected after irradiation, but the peak time (PKT) were reduced with the dose level. Gel consistency (GC) were significantly increased in the tested cultivars, especially in the high AAC Indica rice, suggesting that it is promising to use gamma irradiation to improve eating and cooking quality of rice

Gemstone enhancing dedicated gamma irradiator development

International Nuclear Information System (INIS)

Omi, Nelson Minoru

2006-01-01

The gemstones gamma irradiation process to enhance the color is widely accepted for the jewelry industry. These gems are processed in conventional industrial gamma irradiation plant which are optimized for other purposes, using underwater irradiation devices with high rejection rate due to it's poor dose uniformity. A new conception design, which states the working principles and manufacturing ways of the device, was developed in this work. The suggested device's design is based on the rotation of cylindrical baskets and their translation in circular paths inside and outside a cylindrical source rack as a planetary system. The device is meant to perform the irradiation in the bottom of the source storage pool, where the sources remain always shielded by the water layer. The irradiator matches the Category III IAEA classification. To verify the physical viability of the basic principle, tests with rotating cylindrical baskets were performed in the Multipurpose Irradiator raised in the CTR, IPEN. Also, simulations using the CADGAMMA software, adapted to simulate underwater irradiations were performed. With the definitive irradiator, the irradiation quality will be enhanced with better dose control and the production costs will be significantly lower than market prices due to the intended treatment device's optimization. (author)

Neutron and gamma irradiation damage to organic materials.

Energy Technology Data Exchange (ETDEWEB)

White, Gregory Von, II; Bernstein, Robert

2012-04-01

This document discusses open literature reports which investigate the damage effects of neutron and gamma irradiation on polymers and/or epoxies - damage refers to reduced physical chemical, and electrical properties. Based on the literature, correlations are made for an SNL developed epoxy (Epon 828-1031/DDS) with an expected total fast-neutron fluence of {approx}10{sup 12} n/cm{sup 2} and a {gamma} dosage of {approx}500 Gy received over {approx}30 years at < 200 C. In short, there are no gamma and neutron irradiation concerns for Epon 828-1031/DDS. To enhance the fidelity of our hypotheses, in regards to radiation damage, we propose future work consisting of simultaneous thermal/irradiation (neutron and gamma) experiments that will help elucidate any damage concerns at these specified environmental conditions.

Gamma irradiation versus microbial contamination of Thai medicinal herbs

Directory of Open Access Journals (Sweden)

Wannipa Phianphak

2007-03-01

Full Text Available Seventeen species of herbs established in Thai traditional remedies were microbially decontaminated by gamma-irradiation doses of 7.7 and 8.8 kGy. The herb samples were randomly collected four times from producers in Chiangmai during a 1-year period. These were tested, qualitatively and quantitatively, for total aerobic bacteria, Staphylococcus spp., Salmonella spp., coliform bacteria, and fungi before and after gamma treatment. No microorganisms were found after gamma treatment; and the color, aroma, and texture of the herbs remained normal. The applied dose of gamma irradiation was within the regulatory limits in Thailand (<10 kGy and the main export country (USA< 30 kGy. Gamma irradiation is an effective treatment for microbial decontamination of Thai export herbs.

The effect of natural hot environment on survival and peripheral blood lymphocytes in γ-irradiated mice

International Nuclear Information System (INIS)

Zhou Meijuan; Zheng Li; Ding Zhenhua

2004-01-01

Objective: To study the effect of natural hot environment (NHE) on survival and peripheral blood lymphocytes in γ-irradiated in mice. Methods: After γ-irradiation at the dosage of 6.5 or 9.0 Gy, the mice were exposed to NHE for 0, 3, 6, 9 h or 30 days. After exposure to NHE, mice of the 6 h and 9 h groups, were then bred at room temperature. The survival and peripheral blood lymphocytes were observed for 30 days. Results: There were obvious differences in survival time between the groups that were exposed to NHE for 9 h and 30 d and that of the 0 h group, the mice of these three groups having been irradiated with 6.5 Gy. For 9.0 Gy-irradiated mice, the survival times of the 6, 9 h and 30 d groups were all significantly shorter than that of the 0 h group. The descending rate of peripheral blood lymphocytes in 0 h group is smaller than that of all NHE groups. There was no lymphocyte fluctuate resuscitation in all NHE groups as seen in the 0 h group. Conclusion: There is a significant decrease of survival indexes and a faster descending rate of peripheral blood lymphocytes in mice exposed to after γ-irradiation. (authors)

Mechanisms involved in the differential recovery of CD4 and CD8 T-lymphocytes after local irradiation in mice

International Nuclear Information System (INIS)

De Ruysscher, D; Waer, M.; Vandeputte, M.; Van der Schueren, E.

1990-01-01

The mechanisms involved in the differential recovery of CD4 (helper/inducer phenotype) and CD8 (Cytotoxic/suppressor phenotype) T-lymphocytes after fractionated local irradiation were investigated. In mice, a better recovery of CD4 cells than of CD8 cells was found, while the reverse has been described in humans. Differences in radiosensivitity between CD4 and CD8 mouse splenocytes could not be found. No sequestration of CD8 cells in irradiated tissues could be demonstrated. Irradiation of the thymus did not influence the observed immune changes. Altered thymic production of CD4 and CD8 cells could be excluded by intrathymic injection of FITC (fluorescein isothiocyanate). Hindlimb and tail irradiation did suggest that the differential recovery of CD4 and CD8 T-lymphocytes after local irradiation is determined by extrathymic factors in man and mice, and that the observed differences in immune recovery between man and mice are due to defective thymic function in the former and normal function in the latter. (author). 12 refs.; 5 figs.; 2 tabs

Apoptotic response of irradiated T-Lymphocytes. An epidemiologic study in canine radiotherapy patients

International Nuclear Information System (INIS)

Stankeova, S.; Kaser-Hotz, B.; Crompton, N.E.A.; Blattmann, H.; Theiler, P.; Emery, G.C.; Roos, M.

2003-01-01

Background: Evaluation of radiation-induced apoptosis in T-lymphocytes was developed for human medicine in order to predict the sensitivity of individual patients to radiation therapy and has regular use in cases of suspected hypersensitivity. A major goal of the present study was to evaluate the usefulness of the apoptosis assay in veterinary medicine for application in radiation sensitivity testing. The main goal was to examine potential changes in sensitivity of T-lymphocytes to radiation-induced apoptosis during the course of radiation treatment. This is a clear example of the advantageous use of spontaneous canine tumors to augment human cancer research. Material and Methods: Blood was collected in heparin tubes, diluted 1:10 in RPMI medium, irradiated with X-rays and incubated for 48 h. T-lymphocytes were labeled using FITC-conjugated antibodies, erythrocytes were lysed, and DNA stained with propidium iodide. For cell analysis, a Becton Dickinson FACScan flow cytometer was used. Radiation-induced apoptosis in T-lymphocytes was quantified. Blood samples from tumor-bearing dogs were taken before the first fraction and at the end of radiation therapy. Results: Apoptosis in lymphocytes is dependent on donor age and donor weight. Tumor-bearing dogs when compared with healthy dogs showed no significant differences in levels of induced apoptosis. No significant changes were seen in the levels of radiation-induced apoptosis in blood taken before, during, or after radiation therapy. Conclusion: The leukocyte apoptosis assay can be successfully applied to canine patients, and a wide spectrum of sensitivities to radiation-induced apoptosis is observed. The sensitivity of a patient's peripheral blood T-lymphocytes to radiation-induced apoptosis does not change as a result of the trauma of radiotherapy during the course of tumor treatment. (orig.)

Effect of gamma irradiation on HPMC/ZnO nanocomposite films

International Nuclear Information System (INIS)

Rao, B. Lakshmeesha; Asha, S.; Madhukumar, R.; Latha, S.; Gowda, Mahadeva; Shivananda, C. S.; Harish, K. V.; Sangappa; Shetty, G. Rajesha

2015-01-01

The present work looks into the structural and mechanical properties modification in ZnO nanoparticle incorporated Hydroxypropyl methylcellulose (HPMC) polymer films, induced by gamma irradiation. The irradiation process was performed in gamma chamber at room temperature by use of Cobalt-60 source (Average energy of 1.25MeV) at different doses: 0, 50, 100, 150 and 200 kGy respectively. The changes in structural parameters and mechanical properties in pure and gamma irradiated HPMC/ZnO nanocomposite films have been studied using X-ray scattering (XRD) data and universal testing machine (UTM). It is found that gamma irradiation decreases the structural parameters and improves the mechanical properties of nanocomposite films

Change in the enzymatic dual function of the peroxiredoxin protein by gamma irradiation

International Nuclear Information System (INIS)

An, Byung Chull; Lee, Seung Sik; Lee, Jae Taek; Park, Chul-Hong; Lee, Sang Yeol; Chung, Byung Yeoup

2012-01-01

PP1084 protein was exposed to gamma irradiation ranging from 5 to 500 kGy. Native PAGE showed minor structural changes in PP1084 at 5 kGy, and major structural changes at >15 kGy. Size-exclusion chromatography (SEC) showed the formation of a new shoulder peak when the protein was irradiated with 15 and 30 kGy, and a double peak appeared at 100 kGy. The results of PAGE and SEC imply that PP1084 protein is degraded by gamma irradiation, with simultaneous oligomerization. PP1084 chaperone activity reached the highest level at 30 kGy of gamma irradiation, and then, decreased in a dose-dependent manner with increasing gamma irradiation. However, the peroxidase activity significantly decreased following exposure to all intensities of gamma irradiation. The improvement of chaperone activity using gamma irradiation might be promoted by the oligomeric structures containing covalently cross-linked amino acids. Consequently, PP1084 modification using gamma irradiation could elevate chaperone activity by about 3–4 folds compared to the non-irradiated protein. - Highlights: ► The structure of PP1084 protein was drastically changed above 15 kGy gamma irradiation. ► PP1084 chaperone activity reached the highest level at 30 kGy of gamma irradiation. ► PP1084 modification using gamma irradiation could elevate chaperone activity by about 3–4 folds.

Mechanisms of an increased level of serum iron in gamma-irradiated mice

International Nuclear Information System (INIS)

Xie, Li-hua; Zhang, Xiao-hong; Hu, Xiao-dan; Min, Xuan-yu; Zhou, Qi-fu; Zhang, Hai-qian

2016-01-01

The potential mechanisms underlying the increase in serum iron concentration in gamma-irradiated mice were studied. The gamma irradiation dose used was 4 Gy, and cobalt-60 ( 60 Co) source was used for the irradiation. The dose rate was 0.25 Gy/min. In the serum of irradiated mice, the concentration of ferrous ions decreased, whereas the serum iron concentration increased. The concentration of ferrous ions in irradiated mice returned to normal at 21 day post-exposure. The concentration of reactive oxygen species in irradiated mice increased immediately following irradiation but returned to normal at 7 day post-exposure. Serum iron concentration in gamma-irradiated mice that were pretreated with reduced glutathione was significant lower (p < 0.01) than that in mice exposed to gamma radiation only. However, the serum iron concentration was still higher than that in normal mice (p < 0.01). This change was biphasic, characterized by a maximal decrease phase occurring immediately after gamma irradiation (relative to the irradiated mice) and a recovery plateau observed during the 7th and 21st day post-irradiation, but serum iron recovery was still less than that in the gamma-irradiated mice (4 Gy). In gamma-irradiated mice, ceruloplasmin activity increased and serum copper concentration decreased immediately after irradiation, and both of them were constant during the 7th and 21st day post-irradiation. It was concluded that ferrous ions in irradiated mice were oxidized to ferric ions by ionizing radiation. Free radicals induced by gamma radiation and ceruloplasmin mutually participated in this oxidation process. The ferroxidase effect of ceruloplasmin was achieved by transfer of electrons from ferrous ions to cupric ions. (orig.)

Cholesterol metabolism in blood cells of irradiated rats

International Nuclear Information System (INIS)

Novoselova, E.G.; Kulagina, T.P.; Potekhina, N.I.

1985-01-01

Cholesterol metabolism in blood erythrocytes and lymphocytes of irradiated rats has been investigated. It has been found that at all terms and doses of irradiation, a suppression of the synthesis of erythrocyte cholesterol is observed. The increase of cholesterol quantiy in erythrocytes upon total gamma irradiation in the 10 Gr dose possibly is the result of growth of cholesterol transfer from plasma into erythrocyte cells. The study of the cholesterol synthesis in suspension of lymphocytes elminated from peripheral blood of control and irradiated rats has shown that at irradiation doses of 4 and 10 Gr in an hour acivation of cholesterol synthesis in vitro takes places

Analysis of gamma irradiated pepper constituents, 5

International Nuclear Information System (INIS)

Takagi, Kazuko; Okuyama, Tsuneo; Ishikawa, Toshihiro.

1988-01-01

Gamma irradiated peppers (10 krad, 100 krad, 1 Mrad) were analyzed by HPLC. The extraction method and HPLC conditions were same as the first report, that is, the extraction from pepper was performed by Automatic Air Hammer and the extracted samples were separated on a reversed phase C 8 column with a concave gradient from 0.1% trifluoro aceticacid (TFA) in water to 75% acetonitrile-0.1% TFA in water for 60 minutes and detected at 210 nm, 280 nm. It is difficult to compare with irradiated and unirradiated pepper constituents by their peak height or area. And the method of multi variant statistically analysis was introduced. The 'peak n area/peak n + 1 area' ratio was calculated by computer. Each peak area was accounted by integrator. The value of these ratio were called 'parameter'. Each chromatogram has 741 parameters calculated with 39 chromatographic peaks. And these parameters were abopted to the multi variant statiscally analysis. Comparison of constituents between irradiated pepper and unirradiated pepper was done by 741 parameters. The correlation of parameters between irradiated and unirradiated was investigated by use of computer. Some parameters of irradiated case were selected as which had no correlation with unirradiated case. That is to say these parameters were thought to be changed with gamma spectrum irradiation. By this method, Coumarin was identified as a changed component with gamma irradiation. (author)

Gamma ray irradiation to semi-purified diet

International Nuclear Information System (INIS)

Takigawa, Akihiro; Danbara, Hiroshi; Ohyama, Yoshinobu

1976-01-01

Semi-purified diet containing 10% soybean oil was irradiated with gamma rays at levels of 0.6, 3 and 6 Mrad and was fed to chicks. Crude fat contents of the diets decreased and a considerable amount of peroxide was formed with high doses of irradiation. Feed consumption and feed efficiency of the highly irradiated diets were less than those of control. Metabolizable energy and digestibility of the diets, especially of fat, were decreased with the irradiation. The chicks fed with irradiated diets showed marked dilatation of the small intestine and the liver, and their erythrocytes were more fragile than those of control. The same phenomena were found with the chicks fed the diet containing the oil highly oxidized by autoxidation. Irradiation of the diet excluding oil showed little effect on the growth of chicks. It was considered that these phenomena were caused by the peroxide or other oxidation products of fat which were formed with gamma ray irradiation. (auth.)

Radiation enhanced reactivation of irradiated human adenovirus type 2 in human cells

International Nuclear Information System (INIS)

Jeeves, W.P.

1981-04-01

Radiation-enhanced reactivation (ER) of a radiation-damaged mammalian virus is the term given to the observation that the survival of irradiated virus can be enhanced by irradiation of an appropriate host cell prior to infection. In this work, both UV-enhanced reactivation (UVER) and gamma-ray-enhanced reactivation (γRER) of irradiated human adenovirus type 2 (AD 2) were studied in a variety of normal and DNA repair-deficient human fibroblast host cell strains. In order to examine the lesion specificity of ER in human cells, experiments were performed using UV-irradiated and γ-irradiated virus. The investigation was carried out using a sensitive technique of indirect immunofluorescence, according to which irradiated and unirradiated cell cultures were infected with irradiated or unirradiated AD 2 and were subsequently examined for the presence of viral structural antigens ('V' Ag) at a fixed time after infection

Analysis of the dose-response relationships of chromosomal aberrations after irradiation and bleomycin exposure of different human lymphocyte fractions in vitro

International Nuclear Information System (INIS)

Dresp, J.

1979-01-01

Cytogenetic analyses could be carried out on whole blood and pure T-cell cultures and also on cells of the 'buffy-coat'. In pure B-cell cultures even after 96 hours no mitogenic stimulation could be achieved. Parameters of radiosensitivity and bleomycin sensitivity were dicentric chromosomes, for which the dose-response relationships were calculated. Chromosomal investigations on the 'buffy-coat' cells did not provide indications referring to a varying radiosensitivity compared to whole blood cultures. In pure T-cell cultures T-lymphocytes, which had been separated after whole blood irradiation exposure, showed lower aberration rates than lymphocytes, which had been cultured after whole blood irradiation without previous separation. In the case of bleomycin exposure the treatment of previously separated leucocytes and T-lymphocytes respectively, led to lower aberration rates than the treatment before separation. Therefore it is apparently not necessary for a cytogenetic dosimetry or mutagenicity to depart from the whole blood culture method. (orig./MG) [de

Enhanced biological activities of gamma-irradiated persimmon leaf extract.

Science.gov (United States)

Cho, Byoung-Ok; Nchang Che, Denis; Yin, Hong-Hua; Jang, Seon-Il

2017-09-01

The aim of this study was to compare the anti-oxidative and anti-inflammatory activities of gamma-irradiated persimmon leaf extract (GPLE) with those of non-irradiated persimmon leaf extract (PLE). Ethanolic extract of persimmon leaf was exposed to gamma irradiation at a dose of 10 kGy. After gamma irradiation, the color of the extract changed from dark brown to light brown. The anti-oxidative and anti-inflammatory activities of GPLE and PLE were assessed from: total polyphenol and total flavonoid contents; 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay; 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) assay, and levels of pro-inflammatory mediators such as nitric oxide (NO), prostaglandin E2 (PGE2), tumor necrosis factor alpha (TNF-α) and interleukin-6 (IL-6). The total polyphenol contents of GPLE and PLE were determined to be 224.44 ± 1.54 and 197.33 ± 5.81 mg gallic acid equivalents (GAE)/g, respectively, and the total flavonoid contents of GPLE and PLE were 206.27 ± 1.15 and 167.60 ± 2.00 mg quercetin equivalents (QUE)/g, respectively. The anti-oxidant activities of GPLE and PLE as measured by DPPH assays were 338.33 ± 30.19 μg/ml (IC50) and 388.68 ± 8.45 μg/ml (IC50), respectively, and those measured by ABTS assays were 510.49 ± 15.12 μg/ml (IC50) and 731.30 ± 10.63 μg/ml (IC50), respectively. IC50 is the inhibitor concentration that reduces the response by 50%. GPLE strongly inhibited the production of NO, PGE2 and IL-6 compared with PLE in lipopolysaccharide-stimulated RAW264.7 macrophages. Furthermore, GPLE significantly inhibited the production of TNF-α and IL-6 cytokines compared with PLE in phorbol 12-myristate 13-acetate (PMA) plus A23187-stimulated HMC-1 human mast cells. These results indicate that gamma irradiation of PLE can enhance its anti-oxidative and anti-inflammatory activities through elevation of the phenolic contents. Therefore, gamma-irradiated PLE has potential for use in the food and cosmetic

The effect of caffeine posttreatment on X-ray-induced chromosomal aberrations in human blood lymphocytes in vitro

International Nuclear Information System (INIS)

Natarajan, A.T.; Obe, G.

1980-01-01

The potentiating effect of caffeine on X-ray-induced chromosomal aberrations in human blood lymphocytes has been investigated, with special reference to cell cycle stages (G0 and G2). Both quantitative and qualitative differences in the yield of chromosomal aberrations were detected in caffeine-posttreated cells, depending on the cell stage irradiated. The studies on caffeine potentiating effects on X-irradiated G0 lymphocytes from normal adults, newborns, Down syndrome patients, and an ataxia telangiectasia patient pointed to interindividual variations in the response to caffeine potentiation among normal probands and a very profound effect in ataxia cells. (orig.) [de

Keeping the quality of cows' butter by gamma-irradiation

International Nuclear Information System (INIS)

Rady, A.H.; Badr, H.M.

2003-01-01

This investigation aims to study the use of gamma irradiation for keeping the quality of cows' butter. Fresh butter samples were exposed to gamma irradiation at doses of 0, 2.5 and 5 kGy followed by refrigerated storage and the effects of these treatments on the microbiological aspects and lipid characteristics of butter samples were studied. Moreover, fatty acid profiles and unsaponifiable matter constituents were determined by gas chromatographic analysis, while the stability of butter was determined by rancimat. The results indicated that gamma irradiation at 2.5 kGy dose reduced the counts of total bacteria, lipolytic bacteria, coliforms, molds and yeasts, however, these counts gradually increased during cold storage. Also irradiation at 5 kGy dose greatly reduced the total bacterial count which gradually increased upon storage, while completely eliminated the Other determined microorganisms. Irradiation treatments increased the acid value and peroxide value of butter, while the iodine number was not altered. Moreover, gas chromatographic analysis showed that gamma irradiation slightly increased the total volatile fatty acids, total saturated fatty acids and total hydrocarbons, while slightly decreased the total unsaturated fatty acids and total sterols. In addition, irradiation of butter decreased its stability as determined by rancimat and upon storage of both irradiated and non irradiated butter samples, the acid value gradually increased, while a flexuous changes in the peroxide value were observed. The present study proved that 2.5 and 5 kGy gamma irradiation doses could keep the quality of cows' butter and increased its shelf life at 4 +/- 1degreeC for 8 and 12 weeks as compared to 4 weeks for non irradiated butter (based on the visual appearance of mold growth on the surface of samples) without any effects on its sensory properties [es

Changes in thymocytes due to local irradiation of a portion of the maxilla in mice. A study of NKT cells and {gamma}{delta}T cells

Energy Technology Data Exchange (ETDEWEB)

Satho, Taigo; Tamasawa, Ken; Yosue, Takashi [Nippon Dental Univ., Tokyo (Japan); Arai, Thiaki

2000-07-01

We have been investigating the changes of lymphocyte subsets in immune organs after head and neck irradiation. The aim of the present study was to determine the influence of local irradiation (10 Gy) of a portion of the maxilla on the thymocyte subsets, specifically NKT cells and {gamma}{delta}T cells in mice. The thymocyte subsets were analyzed following irradiation using a fluorometer (anti-CD4, CD8, TCR{alpha}{beta}, TCR{gamma}{delta} and NK1.1 monoclonal antibodies) and the outcome compared with that obtained from no-irradiation groups. The following results were obtained: The total number of thymocytes showed a significant decrease one day and three days after irradiation. The absolute number of DN (double negative; CD4{sup -} CD8{sup -}), CD4{sup +} SP (CD4{sup +} single positive; CD4{sup +} CD8{sup -}) and CD8{sup +} SP (CD8{sup +} single positive; CD4{sup -} CD8{sup +}) thymocytes showed a significant decrease one day after irradiation. The absolute number of DP (double positive; CD4{sup +} CD8{sup +}) thymocytes showed a significant decrease one day and three days after irradiation. The absolute number of NKT and {gamma}{delta}T cells showed a significant decrease one day after irradiation. In conclusion, the results suggest that NKT cells and {gamma}{delta}T cells exhibit behavior which is the same as main stream thymocytes, except DP thymocytes. (author)

Preventive and Therapeutic Effects of Propolis in Gamma Irradiated Rats

International Nuclear Information System (INIS)

Hamza, R.G.; El-Shahat, A.N.

2011-01-01

Ionizing radiation is known to stimulate the generation of oxygen radicals which destabilize organic molecules resulting in a decrease of the system's antioxidant potential. Propolis (bee glue) is a complex mixture of natural substances that exhibits a broad spectrum of biological activities. As the possibility exists that it may exert a radio protections role, the present study aimed to examine the preventive and therapeutic effects of propolis on the gamma irradiation-induced changes in antioxidant status and certain biochemical parameters. HPLC chromatography for analysis of propolis showed that the number of identified phenols was 6 compounds (natural antioxidants). Male albino rats were exposed to 6 Gy of gamma radiation. The efficiency of propolis was evaluated when propolis was administered orally to rats at a dose of 200 mg/kg as follow: non-irradiated rats received orally propolis extract for 6 weeks (positive control) and rats received orally propolis extract for 3 weeks before or after gamma irradiation. The obtained results revealed that propolis given to rats before gamma irradiation protect the hazardous effects of gamma irradiation. In addition, administration of propolis to gamma irradiated rats caused significant enhancement in hepatic antioxidant enzymes (glutathion reductase; GR and catalase; CAT) and total antioxidant capacity associated with a remarkable decrease in the level of lipid peroxidation (TBARS). Also, it significantly reduced the changes induced by gamma irradiation in the serum levels of glucose and liver enzymes; aminotransferases (AST, ALT) and alkaline phosphatase (ALP). In addition, a significant improvement was observed in the serum levels of total cholesterol (TC), triglycerides (TG), low density lipoprotein- cholesterol (LDL-C) and high density lipoprotein-cholesterol (HDL-C). In conclusion, the positive results obtained in the gamma irradiated rats given propolis indicated that propolis could be considered as effective

Computer-controlled gamma-ray scanner for irradiated reactor fuel

International Nuclear Information System (INIS)

Mandler, J.W.; Coates, R.A.; Killian, E.W.

1979-01-01

Gamma-ray scanning of irradiated fuel is an important nondestructive technique used in the thermal fuels behavior program currently under way at the Idaho National Engineering Laboratory. This paper is concerned with the computer-controlled isotopic gamma-ray-scanning system developed for postirradiation examination of fuel and includes a brief discussion of some scan results obtained from fuel rods irradiated in the Power-Burst Facility to illustrate gamma-ray spectrometry for this application. Both burnup profiles and information concerning fission-product migration in irradiated fuel are routinely obtained with the computer-controlled system

Frequency of sister chromatid exchanges in lymphocyte cultures of human peripheral blood after the combined effect of γ-radiation and caffeine

International Nuclear Information System (INIS)

Nugis, V.Yu.; Pyatkin, E.K.

1986-01-01

Keeping of human peripheral blood lymphocytes, irradiated in vitro with 60 Co-γ-quanta at a dose of 3 Gy at G 0 phase, with caffeine of 16 and 160 μg/ml during cultivation with PHA had no appreciable influence on the fraquency of sister chromatid exchanges. A minor increase in the number of sister chromatid exchanges was only noted when nonirradiated and irradiated lymphocytes were cultured with 160 μg/ml caffeine

Enhanced release of bone morphogenetic proteins from demineralized bone matrix by gamma irradiation

International Nuclear Information System (INIS)

Sung, Nak-Yun; Choi, Jong-il

2015-01-01

Gamma irradiation is a useful method for sterilizing demineralized bone matrix (DBM), but its effect on the osteoinductivity of DBM is still controversial. In this study, the osteoinductive activity of gamma-irradiated DBM was examined using a mouse myoblastic cell line (C2C12). DBM was extracted from adult bovine bone and was irradiated at a dose of 25 kGy using a 60 cobalt gamma-irradiator. Cell proliferation with DBM was not affected by gamma-irradiation, but alkaline phosphatase and osteocalcin productions were significantly increased in C2C12 cell groups treated with gamma-irradiated DBM. It was reasoned that bone morphogenetic proteins were more efficiently released from gamma-irradiated DBM than from the non-irradiated control. This result suggests the effectiveness of radiation sterilization of bone implants - Highlights: • Demineralized bone matrix (DBM) was gamma-irradiated for sterilization. • Irradiated DBM had higher alkaline phosphatase and osteocalcin production. • It was reasoned the more released bone morphogenetic proteins by irradiation. • This result supports the application of radiation sterilization for bone implants

Sister chromatid exchange induced by X-irradiation of retinoblastoma lymphocytes

International Nuclear Information System (INIS)

Abramovsky-Kaplan, I.; Jones, I.S.

1984-01-01

Lymphocyte cultures were employed to assess the degree of spontaneous and induced chromosomal fragility in retinoblastoma. Sister chromatid exchange (SCEs) were scored in metaphases. Three unilateral, three bilateral, eleven family members and controls were studied. Retinoblastoma (RB) lymphocytes did not exhibit increased spontaneous fragility. X-irradiation (25-200 rad) did not significantly increase SCE in unilateral retinoblastoma lymphocytes when compared with controls (P greater than 0.50). However, bilaterally affected subjects and three unaffected relatives demonstrated a statistically significant increase in SCE (P less than 0.01). In conclusion, hereditary retinoblastoma lymphocytes appear more radiosensitive than sporadic retinoblastoma, perhaps, reflecting the increased second malignancies in germinal mutation retinoblastoma. In addition, the analysis of radiation-induced SCE in peripheral blood lymphocytes of RB patients and family members may provide a valuable tool increasing the accuracy of genetic counseling for this disorder. Additional studies of RB patients and families are needed to assess the relevance of this approach to genetic counseling

Influence of Gamma-Irradiation on the Growth of Aspergillus spp. on Feeds for Ensuring Feed Safety

International Nuclear Information System (INIS)

Nam, B.R.; Kim, K.Y.; Ryu, H.J.

2010-01-01

Aspergillus spp. is widely spread in the world on feeds and foods. They have been known to produce aflatoxins, which are mutagenic and carcinogenic to humans. The objective of this study was to determine the optimum gamma-irradiation dose for controlling the growth of Aspergillus spp. to ensure safety of feeds. Four species fungal spore (10?7 spore/mL) exposed to 0, 1, 3, 5, 7 and 10 kGy of gamma radiation were inhibited in their growth and AFB? productivity by greater-than or equal to 5 kGy. Meantime, the growth of fungal inoculated on feeds was inhibited at greater-than or equal to 3 kGy. However, AFB? presented in aqueous solution was not be inactivated completely by less-than or equal to 10 kGy irradiation. These results indicate that Aspergillus spp. on feeds could be controlled by 5 kGy gamma-irradiation but detoxification of AFB? demands a higher dose of gamma-irradiation (greater-than or equal to 10 kGy)

Evaluation of spontaneous and radiation-induced micronucleus frequency in cultured human peripheral blood lymphocytes depending on age and sex

Energy Technology Data Exchange (ETDEWEB)

Jeon, H. J.; Kang, C. M.; Chung, H. C. [Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of)] (and others)

2002-12-15

The goal of this study was to provide data on the dose-dependent production of MicroNucleus (MN) in human lymphocytes irradiated with {sup 60}Co {gamma}-rays and 50MeV neutron, and to evaluate predictive markers of intrinsic radiosensitivity in individuals for monitoring occupational or environmental radiation exposure. For the dose-response study, heparinized whole blood of 10 healthy volunteers was irradiated with {sup 60}Co {gamma}-rays employing of 0.25-8Gy. The MNs were observed all doses, and the numerical changes according to doses. In dose-response curves fit linear-quadratic form (alpha =0.31{+-}0.049, beta =0.0022{+-}0.0022) for {gamma}-rays, but (alpha=0.99{+-}0.528, beta =0.0093{+-}0.0047) for neutron. Neutrons were than {gamma}-rays effective in producing MN with dose-dependent manner. The frequency of MN varies with dose. The RBE (Relative Biological Effectiveness) for micronuclei was 2.370.17. Further studies were carried out to provide evidence for the existence of individual variations in age-dependent responses to radiation. Spontaneous and radiation-induced MN varies greatly among individuals, and little is known about the molecular mechanisms of this variability. It was shown that the increased level of spontaneous cell with MN was observed with increasing age. The relationship between radiosensitivity and the increased spontaneous level of MN may be in inverse proportion. These studies indicated that the MN assay have a high potential as a rapid, sensitive and accurate method which can be used to monitor a large population exposed to radiation for rapid triage in the case of a large-scale accident.

Evaluation of spontaneous and radiation-induced micronucleus frequency in cultrued human peripheral blood lymphocytes depending on age and sex

Energy Technology Data Exchange (ETDEWEB)

Jeon, H. J.; Kang, C. M.; Chung, H. C. [Korea Cancer Center Hospital, Seoul (Korea, Republic of)] [and others

2002-07-01

The goal of this study was to provide data on the dose-dependent production of micronucleus (MN) in human lymphocytes irradiated with {sub 60} Co {gamma} -rays and 50MeV neutron, and to evaluate predictive markers of intrinsic radiosensitivity in individuals for monitoring occupational or environmental radiation exposure. For the dose-response study, heparinized whole blood of 10 healthy volunteers was irradiated with {sub 60} Co {gamma} -rays employing of 0.25-8Gy. The MNs were observed all doses, and the numerical changes according to doses. In dose-response curves fit linear- quadratic form (alpha =0.31{+-}0.049, beta =0.0022{+-}0.0022) for {gamma} -rays, but (alpha =0.99{+-}0.528, beta =0.0093{+-}0.0047) for neutron. Neutrons were than {gamma} -rays effective in producing MN with dose-dependent manner. The frequency of MN varies with dose. The RBE for micronuclei was 2.37{+-}0.17. Further studied are carried out to provide evidence for the existence of individual variations in age-dependent responses to radiation. Spontaneous and radiation-induced MN varies greatly between individuals, and little is known about the molecular mechanisms of this variability. It was shown that the increased level of spontaneous cell with MN was observed with increasing age. The relationship between radiosensitivity and the increased spontaneous level of MN may be in inverse proportion. These studies indicates that the MN assay have a high potential as a rapid, sensitive and accurate method which can be used to monitor a large population exposed to radiation for rapid triage in the case of a large-scale accident.

Combined low- and high-dose irradiation and its interpretation from the point of view of radiation protection

International Nuclear Information System (INIS)

Beno, M.

1996-01-01

During the last decade some 'stimulating' or 'hormetic' effects have been ascribed to low-levels of radiation. The adaptive response was a phenomenon recently used as an argument among others advertising such hormetic effects of low dose irradiation. Human peripheral blood lymphocytes may show a decrease of chromosomal aberrations (CA) after high doses of ionizing radiation if they have been previously irradiated by small doses of internally deposited tritium from labelled thymidine, or by small doses of X-rays. This response looks as if some adaptation would take place to the low-dose irradiation and was called 'adaptive response' (AR). It was attributed to repair mechanisms elicited by damaging the lymphocyte DNA by small doses of radiation so that after the high dose, delivered at times when higher levels of repair proteins and other molecules are still present in cells, a lower damaging effect may be expressed. Our work was aimed at gaining information about the frequency distribution of the responses to a combination of low-dose irradiation with tritium and high-dose irradiation with gamma rays and at comparing two endpoints: counts of CA with counts of micronuclei (M) in lymphocytes from the same donors in a human population sample

Toxoplasma gondii gamma irradiation using Co-60

International Nuclear Information System (INIS)

Serra-Freire, Nicolau Maues

1996-01-01

The use of nuclear power through radiation for the destruction of microorganisms which cause food deterioration, infections and toxicosis, is specifically for peaceful purposes. Toxoplasma gondii is a protozoa responsible for illnesses in humans and animals. One of the most common ways of transmission is through raw or poorly cooked meat. There is little information on the resistance of T. gondii to radiation. The objective of this research is to determine the Minimum Lethal Dose (MLD) of gamma radiation for those microorganisms. Suspensions of T. gondii containing approximately one million taquizoites/ml were irradiated with doses between up 0,01 up to 0,15 kGy (Kilogray) and inoculated to mice. The surviving T. gondii were re-irradiated with 0,01 up to 0,16 kGy. The irradiated protozoa were totally destroyed with a 0,15 kGy dose (MLD). Taquizoites issued from live protozoa of 0,14 kGy also were completely destroyed with dose of 0,15 kGy. No increase in resistance was observed regarding the non irradiated protozoa. (author)

Chronic gamma irradiation of ornamental and landscaping plants at gamma greenhouse

International Nuclear Information System (INIS)

Shuhaimi Shamsudin; Zaiton Ahmad; Affrida Abu Hassan

2011-01-01

Activities on chronic gamma irradiation of ornamental and landscaping plants have started since April 2010. Among plants which have been irradiated were landscaping plants such as hibiscus, canna, turnera, plumeria, amaryllis, and ornamental plants such as orchid, heliconia, cucurma and sanseviera, as well as vanilla. The main objectives at the initial stage were to develop database for optimum chronic irradiation dose and suitable experimental design for each species. The ultimate aim is to obtain new varieties of ornamental plants with flower and horticultural traits of commercial values and landscaping plants suitable for Malaysian landscape such as large and colourful flower, longer bloom period and frequent flowering. This paper discusses irradiation activities for ornamental plants in Gamma Greenhouse including preparation of samples, growing medium and screening plots, selection/determination of optimum dose and dose rate, collection of data and selection of mutants. (author)

Effects of gamma-irradiation on meat proteins

International Nuclear Information System (INIS)

Yook, H.S.; Kim, M.R.; Kim, J.O.; Lim, S.I.; Byun, M.W.

1998-01-01

The proteins extracted from beef, pork and chicken meats were irradiated with up to 100 kGy at room temperature. The extracted proteins were evaluated on their in vitro digestibility by incubating successively with pepsin and pancreatin conjugate. Amino acid compositions and SDS-PAGE pattern were also analyzedin for these proteins. Gamma irradiation within the applied dose range (up to 100 kGy) produced negligible in in vitro digestibility and amino acid composition. Analysis of gamma-irradiated proteins by SDS-PAGE revealed radiolysis of ovalbumin to proteins or peptides with lower molecular weight. On the other hand, the proteins directly extracted from irradiated meats containing moisture were also evaluated for their in vitro digestibility, amino acid compositions and SDS-PAGE pattern. However, the results obtained from this experiment were similar to those of irradiated proteins after extraction from the meats

Application of gamma irradiation for inhibition of food allergy

International Nuclear Information System (INIS)

Byun, M.-W.; Lee, J.-W.; Yook, H.-S.; Jo, Cheorun; Kim, H.-Y.

2002-01-01

This study was carried out to evaluate the application of food irradiation technology as a method for reducing food allergy. Milk β-lactoglobulin, chicken egg albumin, and shrimp tropomyosin were used as model food allergens for experiments on allergenic and molecular properties by gamma irradiation. The amount of intact allergens in an irradiated solution was reduced by gamma irradiation depending upon the dose. These results showed that epitopes on the allergens were structurally altered by radiation treatment and that the irradiation technology can be applied to reduce allergenicity of allergic foods

Application of gamma irradiation for inhibition of food allergy

Energy Technology Data Exchange (ETDEWEB)

Byun, M.-W. E-mail: mwbyun@kaeri.re.kr; Lee, J.-W.; Yook, H.-S.; Jo, Cheorun; Kim, H.-Y

2002-03-01

This study was carried out to evaluate the application of food irradiation technology as a method for reducing food allergy. Milk {beta}-lactoglobulin, chicken egg albumin, and shrimp tropomyosin were used as model food allergens for experiments on allergenic and molecular properties by gamma irradiation. The amount of intact allergens in an irradiated solution was reduced by gamma irradiation depending upon the dose. These results showed that epitopes on the allergens were structurally altered by radiation treatment and that the irradiation technology can be applied to reduce allergenicity of allergic foods.

Fungal beta glucan protects radiation induced DNA damage in human lymphocytes.

Science.gov (United States)

Pillai, Thulasi G; Maurya, Dharmendra K; Salvi, Veena P; Janardhanan, Krishnankutty K; Nair, Cherupally K K

2014-02-01

Ganoderma lucidum (Ling Zhi), a basidiomycete white rot macrofungus has been used extensively for therapeutic use in China, Japan, Korea and other Asian countries for 2,000 years. The present study is an attempt to investigate its DNA protecting property in human lymphocytes. Beta glucan (BG) was isolated by standard procedure and the structure and composition were studied by infrared radiation (IR) and nuclear magnetic resonance (NMR) spectroscopy, gel filtration chromatography and paper chromatography. The radioprotective properties of BG isolated from the macro fungi Ganoderma lucidum was assessed by single cell gel electrophoresis (comet assay). Human lymphocytes were exposed to 0, 1, 2 and 4 Gy gamma radiation in the presence and absence of BG. The comet parameters were reduced by BG. The results indicate that the BG of G. lucidum possessed significant radioprotective activity with DNA repairing ability and antioxidant activity as the suggestive mechanism. The findings suggest the potential use of this mushroom for the prevention of radiation induced cellular damages.

New multipurpose gamma-irradiation facility

Energy Technology Data Exchange (ETDEWEB)

Huebner, G

1985-01-01

In the past 3 years much work has been done in the G.D.R. on food irradiation. The experiments have shown that this treatment gives favourable results in many products such as spices, onions, potatoes, chicken, animal feeds, fodder yeast, drugs and vaccines. Economic aspects of food irradiation require the effective use of an irradiation plant and cobalt-60. Therefore, a new multipurpose irradiation facility was developed, applicable as an onion irradiator with a capacity of about 15 ton/h and for the simultaneous irradiation of different products (spices, animal feed, chicken, etc.) in closed product boxes with a size of 1.2 m x 1.0 m x 1.2 m. A microcomputer controls the transport of product boxes around the gamma sources.

Gamma-irradiation of wet corn. Microbiological aspects

International Nuclear Information System (INIS)

Poisson, Jeanne; Cahagnier, B.

1973-01-01

In the course of a survey of several years work on microbiological decontamination and control of wet corn by gamma-irradiation the following factors are studied: inhibiting and selective effect of gamma-irradiation (100 to 500krads) on the microflora of grains; evolution of residual microflora of irradiated wet grains (moisture content about 35%), during storage experiments under ventilated or airtight conditions. Two important points emerge from those studies. The microflora which develops on irradiated sample is much less varied than that of the control sample. The microbial population of an irradiated sample rises up in a few days on a level with the initial one of the control, then goes on increasing while remaining, as a rule, slightly inferior to that of the control placed under the same conditions. This greatly lowers the practical interest of irradiation, which can only be used together with another treatment able to inhibit the quick growth of the residual microflora [fr

Pathologic characteristics of gut-associated lymphoid tissues and lymphocyte apoptosis in mouse intestine after neutron-and γ-irradiation

International Nuclear Information System (INIS)

Fu Kaifei; Peng Ruiyun; Gao Yabing; Wang Dewen; Chen Haoyu; Wu Xiaohong; Yang Yi; Hu Wenhua; Ma Junjie

2004-01-01

Objective: To compare the pathologic characteristics of gut-associated lymphoid tissues and lymphocyte apoptosis in neutron-irradiated mouse small intestines with those in γ-irradiated ones. Methods: Altogether 350 BALB/c mice were irradiated with different doses of neutrons or γ-rays, and were sacrificed on 6 h,12 h,125 d, 7 d, 14 d, 21 d and 28 d after irradiation and their total intestines were removed. Then the pathologic changes and death mode of lymphocytes in gut-associated lymphoid tissues were studied comparatively with light microscopy, electron microscopy and in situ terminal labeling method. Results: The basic pathologic changes of gut-associated lymphoid tissues after neutron irradiation included degeneration, apoptosis and necrosis of lymphocytes. The number of lymphocytes also decreased. There was no obvious regeneration after 4.0 and 5.5 Gy neutron irradiation, while after 2.5 Gy regeneration and recovery appeared, which were, there fore, dose-dependent. In the 2.5 Gy neutron group, the numbers of lymphocytes of intramucosal and submucous lymphoid tissues decreased, and karyopyknosis and a great quantity of nuclear fragments could also be observed at 6 h-3 d after irradiation. However, on the 3rd day regeneration of crypt epithelial cells appeared. On the 5th day hyperplasia of submucous lymphocytic tissues appeared, but recovery to normal level was not achieved till 14 d after irradiation. The basic pathologic changes after γ-irradiation were similar to that of neutron irradiation. Regeneration and recovery appeared in the 5.5 Gy group while no obvious regeneration in the 12.0 Gy group. The results of in situ terminal labeling indicated that at 6 h after irradiation the number of apoptotic cells in gut-associated lymphoid tissues of each group increased obviously, while in 4.0 Gy neutron group and 12.0 Gy γ-ray group it was more abundant. Conclusion: Both 2.5-5.5 Gy neutron and 5.5-12.0 Gy γ-ray irradiation can induce obvious injuries in gut

Effects of chronic whole-body gamma irradiation on cell mediated immunity

International Nuclear Information System (INIS)

Shifrine, M.; Taylor, N.J.; Wilson, F.D.; DeRock, E.W.; Wiger, N.

1979-01-01

The whole blood lymphocyte stimulation test has been used to estimate the effects of chronic, whole-body, gamma irradiation in the dog. At lower dose levels, 0.07 and 0.33 R/day to cumulative dose of about 50 and 250 R, there was no change in cell mediated immunity. Dogs at high dose levels were affected. Dogs which succumbed to aplastic anemia at high doses had reduced immunological responses. Dogs which survived these high doses showed a temporary depression. When aplastic anemia was initially noted, there was a differential response to PHA and Con-A stimulation. The response to the former mitogen was profoundly reduced, but Con-A stimulated cells were unaffected, indicative of the development of radioresistant cell lines. As the dogs progressed toward aplastic anemia, all T lympocytes were negatively affected

Influence of irradiation conditions on the gamma irradiation effect in polyethylene

International Nuclear Information System (INIS)

Kacarevic-Popovic, Z.; Gal, O.; Novakovic, L.J.; Secerov, B.

2002-01-01

Complete text of publication follows. The radiation cross-linking of polyethylene, due to its high cross-linking yield, has resulted in the radiation technology that has found application in radiation production of heat shrinkable structures and in improvement of mechanical and thermo-physical properties of oriented polyethylene objects. It is observed that the cross-linking efficiency decreases when the irradiation is carried out in the presence of oxygen. In order to estimate the conditions that improve cross-linking efficiency, gamma irradiation effect in two types of polyethylene, irradiated in water and air was investigated. The polyethylene samples used were the low density (LDPE) Lotrene CdF 0302 with 45% crystallinity and the high density (HDPE) Hiplex EHM 6003 with 73% crystallinity. Both kinds of samples, fixed in the Pyrex glass tubes, were simultaneously irradiated with 60 Co gamma rays in distilled water and air, at a doses rate of 9,5 kGy/h (determined by the Fricke dosimeter) at room temperature. Radiation induced oxidative degradation was followed through oxygen containing group formation by the carbonyl group band (1720 cm -1 ) and transvinylene group formation by the band at 966 cm -1 in the infrared spectra. Cross-linking efficiency was determined by gel content using the procedure of the extraction in xylene. The monitored effects of gamma irradiation in water and air point to the conclusion that irradiation in water leads to the lower oxidative degradation and higher cross-linking compared with the effects measured after irradiation in air

Modifications induced by gamma irradiation to Makrofol polymer nuclear track detector

Directory of Open Access Journals (Sweden)

A. Tayel

2015-03-01

Full Text Available The aim of the present study was extended from obtaining information about the interaction of gamma rays with Makrofol DE 7-2 track detector to introduce the basis that can be used in concerning simple sensor for gamma irradiation and bio-engineering applications. Makrofol polymer samples were irradiated with 1.25 MeV 60Co gamma radiations at doses ranging from 20 to 1000 kG y. The modifications of irradiated samples so induced were analyzed using UV–vis spectrometry, photoluminescence spectroscopy, and the measurements of Vickers’ hardness. Moreover, the change in wettability of irradiated Makrofol was investigated by the contact angle determination of the distilled water. UV–vis spectroscopy shows a noticeable decrease in the energy band gap due to gamma irradiation. This decrease could be attributed to the appearance of a shift to UV spectra toward higher wavelength region after irradiation. Photoluminescence spectra reveal a remarkable change in the integrated photoluminescence intensity with increasing gamma doses, which may be resulted from some matrix disorder through the creation of some defected states in the irradiated polymer. The hardness was found to increase from 4.78 MPa for the unirradiated sample to 23.67 MPa for the highest gamma dose. The contact angle investigations show that the wettability of the modified samples increases with increasing the gamma doses. The result obtained from present investigation furnishes evidence that the gamma irradiations are a successful technique to modify the Makrofol DE 7-2 polymer properties to use it in suitable applications.

Modulation of Enzymatic Activities of Dual Functional Peroxiredoxin by Gamma Irradiation

International Nuclear Information System (INIS)

Hong, Sung Hyun; Lee, Seung Sik; Park, Chul Hong; Chung, Byung Yeoup

2012-01-01

Recently, enzymes have frequently been used as catalysts in various bio-industrial, commercial, and pharmaceutical applications, because they are more stable, more efficient, and less toxic than the synthetic catalysts. However, one of their major disadvantages is their low thermostability, which leads the researchers to develop new forms of industrially important enzymes with increased resistance to inactivation and aggregation. This study describes a strategy for modifying the molecular chaperone activity of peroxiredoxin (Prx) by using gamma irradiation. Prxs are a ubiquitous family of antioxidant enzymes. Upon oxidation of their peroxidatic Cys, the molecules undergo a structural conversion from a low-molecular-weight (LMW) species acting as a peroxidase to a high-molecular-weight (HMW) complex functioning as a chaperone. In the present study, we examined the effect of gamma irradiation on PP1084 with respect to its protein structure and enzymatic function. The use of gamma irradiation as a physical treatment can increase the cohesive strength of the protein by forming cross-links. The aims of the present work were (1) to improve the chaperone activity of PP1084 by gamma irradiation, (2) to identify the 'optimal' intensity of gamma irradiation, and (3) to investigate the influence of gamma irradiation on protein hydrophobicity as related to chaperone function. Following PP1084 treatment with 30 kGy gamma irradiation, the PP1084 chaperone activity enhanced by about 3-4-fold compared with nonirradiated PP1084, while the peroxidase activity decreased. Ongoing research efforts are addressing the physical modifications of PP1084 protein by gamma irradiation

Sister-chromatid exchange induced by X-ray of human lymphocytes and the effect of L-crysteine

International Nuclear Information System (INIS)

Abramovski, I.; Vorsanger, G.; Hirschhorn, K.

1978-01-01

A staining technique that detects sister-chromatid exchanges (SCEs) has been used to examine the response of human lymphocyte chromosomes to various dosages of X-irradiation. The SCE frequency was markedly increased following irradiation. However, the increase was of a significantly smaller magnitude when irradiation occurred in the presence of an antimutagenic agent. Scoring SCEs may provide a useful technique for assaying the mutagenic effects of environmental carcinogens as well as the protective effects of antimutagenic agents. (Auth.)

Study of gamma irradiation effect on commercial TiO2 photocatalyst

International Nuclear Information System (INIS)

Bello Lamo, M.P.; Williams, P.; Reece, P.; Lumpkin, G.R.; Sheppard, L.R.

2014-01-01

The aim of this work is to understand the effect of gamma irradiation on commercial TiO 2 photocatalyst for water treatment applications. Previous studies concluded that gamma-irradiation is able to modify the electronic properties of TiO 2 based photocatalysts and consequently their photocatalytic performance. However, there are some discrepancies in the literature where on one hand a significant enhancement of the material properties is reported and on the other hand only a weak effect is observed. In this study a surface effect on TiO 2 is confirmed by using low and medium gamma irradiation doses. - Highlights: • Gamma irradiated TiO 2 is investigated for photocatalytic water treatment. • By low gamma doses, no change in surface properties is observed. • However, a surface defect is found for gamma irradiated TiO 2 at higher doses. • XPS measurements showed an increase of hydroxyl groups. • That may cause a variation of its adsorption capacity

Gamma Irradiation on Growth and Development of Amorphophallus muelleri Blume.

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Edi Santosa

2014-09-01

Full Text Available ABSTRACT Iles-iles (Amorphophallus muelleri Blume produces apomictic seeds lead to low genetic variation. In order to induce genetic variation, germinated seeds were exposed to Gamma irradiation (Co-60 at doses of 10 to 100 Gy. Seed irradiation was conducted at Center for the Application of Isotope and Irradiation Technology -National Nuclear Energy Agency (CAIRT, Indonesia. Morphology and yield of M1 generation were observed. Results showed that irradiation at a dose of 10 Gy close to LD50 with survival rate 56%. Gamma irradiation at a dose of 10 Gy delayed seeds germination.  Germination rates gradually increased and reached maximum at 4 weeks after planting (WAP for control plants, and 14 WAP of irradiated plants. At 16 WAP, germination rate of 10 Gy irradiated plants was 56% and 84% for those of control plants. Irradiation induced chimera as indicated by short petiole, variegated and abnornal shape of leaflets. Some irradiated plants entered dormancy at 8-10 weeks later than control ones. Prolong vegetative periode lead the plants to produce heavier corms. This study revealed the possibility to induce variation of A. muelleri by using gamma irradition. Keywords: Amorphophallus muelleri, gamma irradiation (Co-60, morphological variation, mutation breeding

Analysis of the frequency of unstable chromosome aberrations in human lymphocytes irradiated with {sup 60}Co; Analise da frequencia de alteracoes cromossomicas instaveis em linfocitos humanos irradiados com {sup 60}Co

Energy Technology Data Exchange (ETDEWEB)

Mendonca, Julyanne C.G.; Mendes, Mariana E.; Lima, Fabiana F., E-mail: july_cgm@hotmail.com, E-mail: mendes_sb@hotmail.com [Centro Regional de Ciencias Nucleares (CRCN-NE/CNEN-PE), Recife, PE (Brazil); Santos, Neide, E-mail: santos_neide@yahoo.com.br [Universidade Federal de Pernambuco (CCB/UFPE), Recife, PE (Brazil). Departamento de Genetica

2013-07-01

The aim of this study was to analyze the frequency of unstable chromosomal aberrations induced by gamma radiation from a {sup 60}Co source at two different doses. Samples were obtained from a healthy donor and exposed to {sup 60}Co source (Gammacel 220 ) located in the Department of Nuclear Energy of Pernambuco Federal University (DEN/UFPe/Brazil) with a rate of air Kerma to 3,277 Gy/h. Exposures resulted in absorbed dose 0.51 Gy and 0.77 Gy. Mitotic metaphases were obtained by culturing lymphocytes for chromosome analysis and the slides were stained with 5% Giemsa. Among the unstable chromosomal aberrations the dicentric chromosomes, ring chromosomes and acentric fragments were analyzed. To calculate the significance level the chi - square test was used, considering relevant differences between the frequencies when the value of p < 0.05. To calculate the significance level of the chi - square test was used, considering relevant differences between the frequencies when the value of p < 0.05. The results showed that there was significant difference of the frequencies of dicentric chromosomes (from 0.18 to 0.51 to 0.37 Gy to 0.77 Gy), however there was no statistically significant difference between the frequencies of acentric fragments ( 0.054 to 0, 51 Gy to 0.063 to 0.77 Gy) and ring chromosomes (0.001 to 0.51 Gy to 0.003 to 0.77 Gy). The low number of rings is found justified, considering that in irradiated human lymphocytes, its appearance is rare relative to dicentrics. The results confirm that dicentrics are the most reliable biomarkers in estimating dose after exposure to gamma radiation. These two points will make the calibration curve dose-response being built for Biological Dosimetry Laboratory of CRCN-NE/CNEN.

Sterilization by gamma irradiation

International Nuclear Information System (INIS)

Reyes Frias, L.

1992-01-01

Since 1980 the National Institute of Nuclear Research counts with an Industrial Gamma Irradiator, for the sterilization of raw materials and finished products. Through several means has been promoted the use of this technology as alternative to conventional methods of sterilization as well as steam treatment and ethylene oxide. As a result of the made promotion this irradiator has come to its saturation limit being the sterilization irradiation one of the main services that National Institute of Nuclear Research offers to producer enterprises of disposable materials of medical use also of raw materials for the elaboration of cosmetic products and pharmaceuticals as well as dehydrated foods. It is presented the trend to the sterilization service by irradiation showed by the compilation data in a survey made by potential customers. (Author)

Inactivation of fungal contaminants on Korean traditional cashbox by gamma irradiation

Science.gov (United States)

Choi, Jong-il; Lim, Sangyong

2016-01-01

In this study, gamma irradiation was applied to decontaminate a Korean cultural artifact, a wooden cashbox stored in local museum. Fungi isolated from the wooden cashbox were identified by 18S rDNA sequencing methods. It was observed that the isolated fungi exhibited high similarity to Aspergillus niger, Penicillium verruculosum, and Trichoderma viride. Each strain was tested for sensitivity to gamma irradiation, and was inactivated by the irradiation at a dose of 5 kGy. The wooden cashbox was thus gamma-irradiated at this dose (5 kGy), and consequently decontaminated. Two months after the irradiation, when the wooden cashbox was retested to detect biological contamination, no fungi were found. Therefore, these results suggest that gamma irradiation at a low dose of 5 kGy can be applied for successful decontamination of wooden artifacts.

Effect of gamma irradiation on storability of strawberry (Fragaria sp)

Energy Technology Data Exchange (ETDEWEB)

Al-Bachir, M; Farah, S [Atomic Energy Commission, Dept. of Agriculture, Damascus (Syrian Arab Republic)

1998-02-01

Despite the increased production of strawberry in Syria, the storability and marketability of fruits were not well studied. The objectives of this study were to investigate the effect of gamma irradiation on storability of Senga sengana strawberry produced in Syria and the effect of gamma irradiation on fungal sp. i.e. Botrytis; Penicillium; Rhizopus. The fruits were treated with 1 , 2 and 3 KGy of gamma rays. Treated and untreated fruits were stored at 2 to 4 centigrade and 80 to 90 % relative humidity (RH). In order to investigate their marketability, the fruits where held at room temperature (25 to 30 centigrade). Weight loss, microbial decay, and total loss, juice production, pH, total soluble solids of the juice and organoleptic qualities were evaluated throughout the different storage and marketing periods. The results indicate that gamma irradiation decreased the microbial decay and increased the storability and marketability of fruits by 50 and 100% after using 2 and 3 kGy, respectively. D10 were 1.8 and 2.4 for Botrytis and Rhizopus respectively. One day after irradiation total soluble solids and its pH values were increased. Fourteen days later, irradiated fruits produced more juice with higher pH, but total soluble solids were less. Gamma irradiation did not have an effect on aroma and colour of fruits, whereas, 3 kGy of gamma irradiation had an adverse negative effect on taste. (author)

Kraft cooking of gamma irradiated wood, (1)

International Nuclear Information System (INIS)

Inaba, Masamitsu; Meshitsuka, Gyosuke; Nakano, Junzo

1979-01-01

Studies have been made of kraft cooking of gamma irradiated wood. Beech (Fagus crenata Blume) wood meal suspended in aqueous alkaline alcohol was irradiated up to 1.5 KGy (0.15 Mrad) with gamma rays from a Co-60 source in the presence or absence of oxygen. The irradiated wood meals were washed thoroughly with fresh water, air dried and cooked under the ordinary cooking conditions. The results are summarized as follows: (1) Pre-irradiation in aqueous alkali have negligible effect on kraft cooking. (2) In the case of ethanol addition (50 g/l), pre-irradiation in vacuo shows acceleration of delignification and stabilization of carbohydrates during kraft cooking. Cooked yield gain by pre-irradiation was about 1.2% in all over the range of delignification from 80 to 90%. Aqueous ethanol without alkali also shows positive but smaller effect than that with alkali. (3) Propanol, iso-propanol and butanol show positive but smaller effects than ethanol. However, methanol does not show any positive effect. (4) Irradiation in the presence of oxygen does not show any attractive effect on kraft cooking. (author)

Inhibition of DNA repair by whole body irradiation induced nitric oxide leads to higher radiation sensitivity in lymphocytes

International Nuclear Information System (INIS)

Sharma, Deepak; Santosh Kumar, S.; Raghu, Rashmi; Maurya, D.K.; Sainis, K.B.

2007-01-01

Full text: It is well accepted that the sensitivity of mammalian cells is better following whole body irradiation (WBI) as compared to that following in vitro irradiation. However, the underlying mechanisms are not well understood. Following WBI, the lipid peroxidation and cell death were significantly higher in lymphocytes as compared to that in vitro irradiated lymphocytes. Further, WBI treatment of tumor bearing mice resulted in a significantly higher inhibition of EL-4 cell proliferation as compared to in vitro irradiation of EL-4 cells. The DNA repair was significantly slower in lymphocytes obtained from WBI treated mice as compared to that in the cells exposed to same dose of radiation in vitro. Generation of nitric oxide following irradiation and also its role in inhibition of DNA repair have been reported, hence, its levels were estimated under both WBI and in vitro irradiation conditions. Nitric oxide levels were significantly elevated in the plasma of WBI treated mice but not in the supernatant of in vitro irradiated cells. Addition of sodium nitroprusside (SNP), a nitric oxide donor to in vitro irradiated cells inhibited the repair of DNA damage and sensitized cells to undergo cell death. It also enhanced the radiation-induced functional impairment of lymphocytes as evinced from suppression of mitogen-induced IL-2, IFN-γ and bcl-2 mRNA expression. Administration of N G -nitro-L-arginine-methyl-ester(L-NAME), a nitric oxide synthase inhibitor, to mice significantly protected lymphocytes against WBI-induced DNA damage and inhibited in vivo radiation-induced production of nitric oxide. Our results indicated that nitric oxide plays a role in the higher radiosensitivity of lymphocytes in vivo by inhibiting repair of DNA damage

Radioprotective effect of sesamol on γ-radiation induced DNA damage, lipid peroxidation and antioxidants levels in cultured human lymphocytes

International Nuclear Information System (INIS)

Prasad, N. Rajendra; Menon, Venugopal P.; Vasudev, V.; Pugalendi, K.V.

2005-01-01

Sesamol pretreated (1, 5 and 10 μg/ml) lymphocytes were exposed to different doses of γ-radiation, i.e., 1, 2 and 4 Gray (Gy) and the cellular changes were estimated by using cytokinesis blocked micronucleus assay (MN), dicentric aberration (DC), thiobarbituric acid reactive substances (TBARS), reduced glutathione (GSH) and the activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx). Radiation significantly increased MN, DC frequencies, TBARS levels and decreased GSH and antioxidant enzyme levels in a dose dependent manner. The highest damage to lymphocytes was observed at 4 Gy irradiation. On the other hand, sesamol pretreatment significantly decreased MN, DC frequencies, TBARS levels and increased GSH levels and SOD, CAT and GPx activities in a concentration dependent manner. At 1 Gy irradiation all concentrations of sesamol (1, 5 and 10 μg/ml) significantly protects the lymphocytes from radiation damage. At 2 Gy irradiation 5 and 10 μg/ml of sesamol shows significant radioprotection. Since the highest damage was observed at 4 Gy irradiation both 1 and 5 μg/ml of sesamol pretreatment were not sufficient to protect the lymphocytes from radiation damage but 10 μg/ml of sesamol significantly (p < 0.05) protects the lymphocytes from radiation effect. Thus, sesamol pretreatment gives significant protection to cultured human lymphocytes against γ-radiation induced cellular damage. The possible mechanism involved in the radioprotective influence of sesamol is discussed

Gamma ray-irradiation in fresh allo-joint transplantation

International Nuclear Information System (INIS)

Watanabe, Hiroshi

1995-01-01

In the first of a series of experiments in rat designed to assess the efficacy of gamma ray irradiation in fresh allo-joint transplantation, it was found that the optimal gamma ray dosage was 4 Gy. At this dosage level, the irradiation rays suppressed the viability of marrow cells which had the highest antigenicity, with no injury to the bone or articular cartilage. In a second experiment, a fresh homologous knee joint was irradiated at 4 Gy and then transplanted while administering the donor's splenic cell suspension (for specific immunosuppression) and the immunosuppressive agent cyclosporine (5 mg/kg) to the recipient rat. All the rats that received a pre-irradiated knee joint graft survived until sacrificed for evaluation without showing any sign of host rejection. In these rats, bone fusion had occurred between the host bone and the graft by the 8th postoperative week. Degeneration of the articular cartilage was similar between the rats that had received a pre-irradiated graft and those that had not. These findings indicated that 4 Gy gamma ray irradiation to a graft before transplantation provided an effective means of immunosuppression. (author)

Dose mapping role in gamma irradiation industry

International Nuclear Information System (INIS)

Noriah Mod Ali; John Konsoh Sangau; Mazni Abd Latif

2002-01-01

In this studies, the role of dosimetry activity in gamma irradiator was discussed. Dose distribution in the irradiator, which is a main needs in irradiator or chamber commissioning. This distribution data were used to confirm the dosimetry parameters i.e. exposure time, maximum and minimum dose map/points, and dose distribution - in which were used as guidelines for optimum product irradiation. (Author)

Gamma-ray irradiation of a boreal forest ecosystem

International Nuclear Information System (INIS)

Guthrie, J.E.; Dugle, J.R.

1983-01-01

A long-term radiation ecology research project called Field Irradiator - Gamma (FIG) began at the Whiteshell Nuclear Research Establishment in 1968. The experimental area is in southeastern Manitoba and is located on the western edge of the Precambrian shield. The project studies the ecological effects continuous exposure to a gradient of gamma radiation has on a mixed boreal forest ecosystem. The gradient ranges from 1 to 460,000 times the natural background radiation level. This paper describes the forest, the gamma irradiator and its radiation field, and the research program

Effect of gamma irradiation on storability of apples (Malus Domestica L.)

International Nuclear Information System (INIS)

Al-Bachir, M.

2000-01-01

The aim of this study was to investigate the effect of gamma irradiation on storability of the two main apple varieties, Golden Delicious and Starking, in Syria. The experiments were performed in 1995 and 1996. Fruits were irradiated with 0, 0.5, 1.0 and 1,5 kGy. Irradiated and unirradiated fruits were stored at 1 to 2 Centigrade and 80 to 90% Rh. Weight loss and spoilage due to physiological disorders and fungal diseases were evaluated throughout the different storage periods. firmness, coloration and Ph values were estimated immediately after irradiation. The results showed that, in both varieties, gamma irradiation increased the weight loss after 45 days of storage in apples gathered in 1995 but not in the 1996 season. After 180 days of storage, gamma irradiation had different effects on weight loss depending on the growing year and variety, and increased fungal spoilage. Application of gamma irradiation prevented the growth of Aspergillus niger and the formation of skin scald in 'Golden Delicious' fruits. Immediately after treatment, gamma irradiation increased the softening of fruits, changed their color from green to yellow and decreased the Ph value of the juice. (author)

Toxicity Test on Malondialdehyde Content and Antioxidant Capacity of Irradiation Sterilization Rendang : In Vitro

International Nuclear Information System (INIS)

Zubaidah Irawati; Kamalita Pertiwi; Fransiska Rungkat Zakaria

2010-01-01

The safety of irradiated ethnic ready to eat food at high doses raises many questions, and recognized as one of great obstacles in the development of commercialization of food irradiation globally. People are still worried that food treated with irradiation would have induced radioactivity because free radical and its complex derivatives are formed in the irradiation process. Therefore, this study is needed to help understanding the effect of irradiated food on biological system in order to understand the possible effect to human body. The aimed of this research work was to secure the safety of irradiated food at high dose by conducting a toxicity assay using lymphocytes and erythrocytes human blood, and to determine antioxidant capacity of gamma - sterilized rendang at 45 kGy.The methods used were extraction and preparation of rending samples, culture medium preparation, lymphocytes isolation, the assays on lymphocytes proliferation, erythrocytes hemolysis,, antioxidant capacity, and malonaldehyde, respectively. The tested samples were irradiated at PATIR BATAN on 11 th November 2006 (sample A), on 14 th June 2007 (sample B), and “No Label” on 14 th June 2007 (sample C), respectively and non irradiated rending as control was also prepared. The results of proliferation assay showed that irradiated samples did neither inhibit nor induce proliferation significantly. Obviously, hemolysis rate of all samples showed increasing rate with increasing concentration or inversely correlated with dilution neither caused an increase in erythrocytes hemolysis rate nor inhibition in erythrocytes hemolysis significantly. Antioxidant capacity assay in irradiated samples showed higher value than in non-irradiated sample while irradiation treatment did not influence malonaldehyde content in rendang. (author)

A comparison of the effects of 900 MHz electromagnetic fields and gamma ionizing radiation in human peripheral blood lymphocytes

Energy Technology Data Exchange (ETDEWEB)

Savova, G.; Stankova, K. [Molecular Radiobiology and Prophylaxis Laboratory, National Centre of Radiobiology and Radiation Protection, Sofia (Bulgaria); Kuzmanova, M. [Sofia University „St. Kl. Ohridski”, Faculty of Biology, Sofia (Bulgaria)

2013-07-01

The usage of mobile phones increased significantly in the last 15 years. The concerns about the potential negative health effects arise, because of the daily use of electromagnetic field (EMF) sources. EMF, produced by cell phones may affect biological systems by increasing the production of free radicals, and even DNA damage. Other environmental factor, with an impact on humans’ life is the ionizing radiation. The main purpose of this work is to compare the effects of 900-MHz radiofrequency fields and gamma-ionizing radiation (γ-IR) on the levels of free radicals and DNA damage in human peripheral blood mononuclear cells (PBMC). The EMF generated, at a power of 2W used for cell phone applications, led to a significant increase in the levels of intracellular reactive oxygen species (ROS), but not in persisting DNA damage 2h post-exposure. In contrast, irradiation with 4Gy of gamma rays increased dramatically both - the intracellular ROS and the DNA damage compared to background. (author)

Inactive Doses and Protein Concentration of Gamma Irradiated Yersinia Enterocolitica

International Nuclear Information System (INIS)

Irawan Sugoro; Sandra Hermanto

2009-01-01

Yersinia enterocolitica is one of bacteria which cause coliform mastitis in dairy cows. The bacteria could be inactivated by gamma irradiation as inactivated vaccine candidate. The experiment has been conducted to determine the inactive doses and the protein concentration of Yersinia enterocolitica Y3 which has been irradiated by gamma rays. The cells cultures were irradiated by gamma rays with doses of 0, 100, 200, 400, 600, 800, 1.000 and 1.500 Gy (doses rate was 1089,59 Gy/hours). The inactive dose was determined by the drop test method and the protein concentration of cells were determined by Lowry method. The results showed that the inactive doses occurred on 800 – 1500 Gy. The different irradiation doses of cell cultures showed the effect of gamma irradiation on the protein concentration that was random and has a significant effect on the protein concentration. (author)

A comparative study of radioprotective effect of several antioxidants on human blood lymphocytes

International Nuclear Information System (INIS)

Wang Mingsuo; Zhu Gengbai; Gu Xuandi

1992-01-01

By means of improved fluorometric method with 2-thiobarbituric acid (TBA) as the fluorometric agent, radioprotective effects of four kinds of antioxidants on 60 Co γ-ray induced lipid peroxidation (LPO) level, i.e. Malondialdehyde (MDA) content changes in human blood lymphocytes were in human blood lymphocytes were compared by using relative protective efficiency (RPE) as an indicator. The LPO level in human lymphocytes which had been treated with an antioxidant at an concentration of 5 x 10 -3 g/L for 1 hr was measured 2 hr after exposure to 4 Gy of γ-rays, and the RPE values of antioxidants were calculated under these conditions: SOD, 38.23; VE, 23.75:VC, 19.32 and Se +4 , 18.27, thus the anticipation that the compounds, superoxide dismutase (SOD), 2-tocopherols (VE), ascorbic acid (VC) and Na 2 SeO 3 (Se +4 ) had radioprotective effects was confirmed. It was found that the radioprotective beneficial sequences of four kinds of antioxidants were arranged as SOD>VE>VC,Se +4 . The results show that radioprotective effects of exogenous antioxidants on radiation induced LPO damage are dependent not only on irradiation dosage, but also especially on property of antioxidants, drug concentration, pretreatment and monitoring time, etc. The mechanism of these antioxidants effecting as radioprotectants on human lymphocytes is discussed in connection with LPO damage and radioprotection

Operating experience with gamma ray irradiators

International Nuclear Information System (INIS)

Fraser, F.M.; Ouwerkerk, T.

1980-01-01

The experience of Atomic Energy of Canada, Limited (AECL) with radioisotopes dates back to the mid-1940s when radium was marketed for medical purposes. Cobalt-60 came on the scene in 1949 and within a few years a thriving business in cancer teletherapy machines and research irradiators was developed. AECL's first full-scale cobalt-60 gamma ray sterilizer for medical products was installed in 1964. AECL now has over 50 plants and 30 million curies in service around the world. Sixteen years of design experience in cobalt-60 sources, radiation shielding, safety interlock systems, and source pass mechanisms have made gamma irradiators safe, reliable, and easy to operate. This proven technology is being applied in promising new fields such as sludge treatment and food preservation. Cesium-137 is expected to be extensively utilized as the gamma radiation source for these applications

Borosilicate glass for gamma irradiation fields

Science.gov (United States)

Baydogan, N.; Tugrul, A. B.

2012-11-01

Four different types of silicate glass specimens were irradiated with gamma radiation using a Co-60 radioisotope. Glass specimens, with four different chemical compositions, were exposed to neutron and mixed neutron/gamma doses in the central thimble and tangential beam tube of the nuclear research reactor. Optical variations were determined in accordance with standardisation concept. Changes in the direct solar absorbance (αe) of borosilicate glass were examined using the increase in gamma absorbed dose, and results were compared with the changes in the direct solar absorbance of the three different type silicate glass specimens. Solar absorption decreased due to decrease of penetration with absorbed dose. αe of borosilicate increased considerably when compared with other glass types. Changes in optical density were evaluated as an approach to create dose estimation. Mixed/thermal neutron irradiation on glass caused to increse αe.

An Assessment of the Effects of Different Dose Levels of Gamma Rays on HPRT Gene of T-Cells from Human Peripheral Blood

International Nuclear Information System (INIS)

Bahreyni, M. T.; Rezaee, M.

2004-01-01

Ionizing radiation has been shown to produce a broad range of genetic aberrations in human and other species. Most of the genetic aberrations are deletions. To study genetic alterations, an assessment of somatic ell gene mutations induced by ionizing radiation is proper method. In this study, the intragenic and total gene deletions of 18 HPRT-mutants derived from T-lymphocytes and induced by gamma rays were analyzed. PCR amplification of individual HPRT exons and multiplex PCR. HPRT-mutants were isolated by treatment of irradiated samples with 6-thioguanine. MPCR and PCR of individual exons of HPRT demonstrated that the intragenic and total gene deletions were not significantly different. The samples including more than one deletion had non-random significantly higher frequency. Mapping of all intragenic deleltion exhibited a nonrandom distribution. Middle part of HPRT gene was more sensitive to gamma rays. The sensitivity was increased with radiation dose. This study showed that the size of deletions are dose dependent. Our results suggest that alterations in T- lymphocytes mutant genes, induced deletions, size of deletions and distribution of DNA breakpoints appeared to be dependent on low LET radiation dose. (Author) 11 refs

Dynanics of populations of T- and B-lymphocytes in the irradiated body

International Nuclear Information System (INIS)

Yarilin, A.A.

1978-01-01

On the basis of literary data analysis the estimation of lymphocyte radiosensitivity with the account of dividing this cell type into numerous varieties is given. Estimation results have shown that during in vitro irradiation at 1000 P dose rate in the first day 80 percent of blood B-cells and about 30 percent of T cells are killed. By the fourth day lymphocyte killing approaches maximum: B cells vanish practically completely, and T cells make up 6-8% of the initial content. The lymphocyte reduction greatly depends on an injury character. T and B lymphocyte reduction dynamics is in principle analogous except for some difference in reduction periods

Examination of irradiated fuel elements using gamma scanning technique

International Nuclear Information System (INIS)

Ichim, O.; Mincu, M.; Man, I.; Stanica, M.

2016-01-01

The purpose of this paper is to validate the gamma scanning technique used to calculate the activity of gamma fission products from CANDU/TRIGA irradiated fuel elements. After a short presentation of the equipments used and their characteristics, the paper describes the calibration technique for the devices and how computed tomography reconstruction is done. Following the previously mentioned steps is possible to obtain the axial and radial profiles and the computed tomography reconstruction for calibration sources and for the irradiated fuel elements. The results are used to validate the gamma scanning techniques as a non-destructive examination method. The gamma scanning techniques will be used to: identify the fission products in the irradiated CANDU/TRIGA fuel elements, construct the axial and radial distributions of fission products, get the distribution in cross section through computed tomography reconstruction, and determine the nuclei number and the fission products activity of the irradiated CANDU/TRIGA fuel elements. (authors)

Gamma irradiation for sewage treatment at US army facilities

International Nuclear Information System (INIS)

Van den Berg, A.J.; Hollis, H.D.; Musselman, H.D.; Woodbridge, D.D.

1975-01-01

The US Army Corps of Engineers has been sponsoring research for many years on the use of gamma irradiation for disinfection and sterilization of sewage plant effluents. Initial research was directed to laboratory experiments using sterile solutions to determine the effects of gamma irradiation on E. coli, M-pyogenes and M-smegmatis organisms, and on the chemical constituents of sewage such as phenols, surfactants and pesticides. The results of the initial research warranted further study using municipal sewage secondary effluent as test samples. Current research is directed towards investigating the effects of radiation on the constituents of sewage sludge and on the cyst stage of the amoebic protozoa. Consideration has been given by the Corps to the management of waste-waters by disposal on land. Legal and medical reasons dictate that the plant effluents be sterilized before being used as fertilizers and soil conditioners. Gamma radiation from isotopic sources appears to be the best source of sterilizing energy for Army waste-water disposal. The Corps of Engineers is considering the construction of an experimental gamma irradiation pilot facility to validate laboratory experimental work and to establish design criteria for operating plants. The data obtained will provide a basis for performing detailed cost effectiveness studies on gamma irradiation as a method to treat secondary plant effluent. In addition, optimization work will be conducted to determine where in the sewage treatment cycle the use of gamma irradiation will produce the best results in meeting current and anticipated standards. (author)

Induced disease resistance of satsuma mandarings against penicillium digitatum by gamma irradiation

International Nuclear Information System (INIS)

Jeong, Rae Dong

2017-01-01

Gamma irradiation, which is a type of ionizing radiation, can be used as a fruit inducible factor. In the present study, the effects of gamma irradiation on the resistance of mandarin fruits against Penicillium digitatum, the causal agent of postharvest green mold disease, were investigated. Pretreatment of a low dose of gamma irradiation effectively reduced the disease incidence and lesion diameter of mandarin fruits inoculated with P. digatatum during storage for 14 d. Interestingly, exposed to 400 Gy of gamma irradiation significantly maintained firmness and stimulated the synthesis of defense-related enzymes, (e.g., β-1,3-glucanase, phenylalanine, peroxidase, and polyphenol oxidase) and pathogenesis-related (PR) genes (e.g., PR-1 and PR-2). Therefore, the gamma irradiation-induced resistance against P. digatatum involves both changes of phenolic compounds and the induction of expression of defense-related genes. In addition, scanning electron microscopy analysis revealed that induced disease resistance by gamma irradiation signifcantly inhibits the growth of P. digatatum in mandarin fruits. These results suggest that the exposure of gamma irradiation is a potential methods for inducing the disease resistance of fruit to postharvest fungal pathogens and for extending the postharvest life of mandarin fruit

Induced disease resistance of satsuma mandarings against penicillium digitatum by gamma irradiation

Energy Technology Data Exchange (ETDEWEB)

Jeong, Rae Dong [Dept. of Applied Biology, Institute of Environmentally Friendly Agriculture, Chonnam National University, Gwangju (Korea, Republic of)

2017-06-15

Gamma irradiation, which is a type of ionizing radiation, can be used as a fruit inducible factor. In the present study, the effects of gamma irradiation on the resistance of mandarin fruits against Penicillium digitatum, the causal agent of postharvest green mold disease, were investigated. Pretreatment of a low dose of gamma irradiation effectively reduced the disease incidence and lesion diameter of mandarin fruits inoculated with P. digatatum during storage for 14 d. Interestingly, exposed to 400 Gy of gamma irradiation significantly maintained firmness and stimulated the synthesis of defense-related enzymes, (e.g., β-1,3-glucanase, phenylalanine, peroxidase, and polyphenol oxidase) and pathogenesis-related (PR) genes (e.g., PR-1 and PR-2). Therefore, the gamma irradiation-induced resistance against P. digatatum involves both changes of phenolic compounds and the induction of expression of defense-related genes. In addition, scanning electron microscopy analysis revealed that induced disease resistance by gamma irradiation signifcantly inhibits the growth of P. digatatum in mandarin fruits. These results suggest that the exposure of gamma irradiation is a potential methods for inducing the disease resistance of fruit to postharvest fungal pathogens and for extending the postharvest life of mandarin fruit.

Pollen-gamma irradiation on pineapple and pollination using irradiated pollen

International Nuclear Information System (INIS)

Benega, R.; Cisneros, A.; Martinez, J.; Arias, E.; Yabor, L.; Isidron, M.; Castillo, E.; Fernandez, J.

1997-01-01

In order to try to induce haploid plants, pineapple (Ananas comosus (L.) ;err.) pollen grains were gamma-rays irradiated with a Co 60 source at rates of doses from 0 to 300 Gy. The effect of gamma-rays on the generative-nucleus division and vitro pollen viability as well as, seed contents and plantlets obtained after pollinations was analysed. The were reducing in the division frequencies of generative nucleus at all assayed doses. The LD50 was achieved among 200 and 250 Gy. There were not differences on pollen viability in the rates of assayed doses. Seed contents were dose-dependent. The percentages of seed full and seed containing only embryos decreases at increasing of irradiation doses. Contrary effect was observed on the seed empty. Some plantlets regenerated from the different irradiation doses showed phenotypes with small and leaves and short inter nodes

Economics of gamma processing in cobalt-60 irradiation facilities

International Nuclear Information System (INIS)

Gay, H. G.; Kotler, J. G.

1985-01-01

Gamma processing by cobalt-60 is well established. However, since irradiation of food is relatively new from the commercial point of view, it is important to assess costs of gamma irradiation in the context of food processing. Five different types of AECL-RCC irradiation equipment are examined in terms of their throughputs, and capital and operating costs. Using these figures, costs of irradiation of nine types of food products are presented. In general, these represent about 2-10% of the wholesale cost of these products

Effect of gamma irradiation on storability of apples (Malus domestica L.)

Energy Technology Data Exchange (ETDEWEB)

Al-Bachir, M [Atomic Energy Commission (AECS), Dept. of Radiation Agriculture, Damascus (Syrian Arab Republic)

1997-12-01

The effects of gamma irradiation on storability of two main apple varieties in Syria, Golden Delicious and Starking, were investigated. Fruits were irradiated with 0, 0.5, 1, and 1.5 kGy and combined irradiation with 1 kGy after packaging the fruits with polyethylene or paper bags. Irradiated and unirradiated fruits were stored at 1 to 2 C deg and 80 to 90% Rh. Weight loss and spoilage were evaluated throughout the different storage periods. Firmness, coloration and pH values were estimated immediately after irradiation. The results showed that in both varieties, gamma irradiation increased the weight loss after 45 days of storage in the 1995, but not in the 1996 season. After 180 days of storage gamma irradiation had different effects on weight loss depending on the season and variety, and increased the fungal spoilage. Application of gamma irradiation prevented the growth of Aspergillus niger and the formation of skin scald in Golden Delicious fruits. Immediately after treatment, gamma irradiation increased the softening of fruits, changed their colour from green to yellow and decreased the pH value of the juice. Combined treatments decreased the rate of weight loss and skin scald in Golden Delicious fruits and increased the fungal spoilage. (author)

Dose-dependent and gender-related radiation-induced transcription alterations of Gadd45a and Ier5 in human lymphocytes exposed to gamma ray emitted by 60Co

International Nuclear Information System (INIS)

Tavakoli, H.; Manoochehri, M.; Mosalla, S. M. M.; Ghafori, M.; Karimi, A. A.

2013-01-01

Growth arrest DNA damage-inducible 45a gene (Gadd45a) and immediate early response gene 5 (Ier5) have been emphasised as ideal radiation bio-markers in several reports. However, some aspects of radiation-induced transcriptional alterations of these genes are unknown. In this study, gender-dependency and dose-dependency as two factors that may affect radiation induced transcription of Gadd45a and Ier5 genes were investigated. Human lymphocyte cells from six healthy voluntary blood donors (three women and three men) were irradiated in vitro with doses of 0.5-4.0 Gy from a 60 Co source and RNA isolated 4 h later using the High Pure RNA Isolation Kit. Dose and gender dependency of radiation-induced transcriptional alterations of Gadd45a and Ier5 genes were studied by quantitative real-time polymerase chain reaction. The results showed that as a whole, Gadd45a and Ier5 gave responses to gamma rays, while the responses were independent of radiation doses. Therefore, regardless of radiation dose, Gadd45a and Ier5 can be considered potential radiation bio-markers. Besides, although radiation-induced transcriptional alterations of Gadd45a in female and male lymphocyte samples were insignificant at 0.5 Gy, at other doses, their quantities in female samples were at a significantly higher level than in male samples. Radiation induced transcription of Ier5 of females samples had a reduction in comparison with male samples at 1 and 2 Gy, but at doses of 0.5 and 4 Gy, females were significantly more susceptible to radiation-induced transcriptional alteration of Ier5. (authors)

Biohydrogen production using waste activated sludge disintegrated by gamma irradiation

International Nuclear Information System (INIS)

Yin, Yanan; Wang, Jianlong

2015-01-01

Highlights: • The waste activated sludge could be disintegrated by gamma irradiation. • The disintegrated sludge could be used for biohydrogen production. • Combined alkali-irradiation treatment achieved the highest solubilization of sludge. - Abstract: The biohydrogen production using the disintegrated and dissolved sludge by gamma irradiation was studied. The experimental results showed that gamma irradiation and irradiation combined with alkali pretreatment could disintegrate and dissolve waste activated sludge for biohydrogen production. The alkali-irradiation treatment of the sludge at pH = 12 and 20 kGy achieved the highest disintegration and dissolution, i.e., it could destroy the cell walls and release organic matters (such as soluble COD, polysaccharides and protein) into the solution. The disintegrated sludge could be used as a low-cost substrate for biohydrogen production

Food safety aspect : Toxicity test of gold fish pepes sterilized by gamma irradiation in vitro

International Nuclear Information System (INIS)

Zubaidah Irawati; Kallista Rachmavika Putri; Fransiska Rungkat Zakaria

2011-01-01

Ionizing radiation is a physical preservation technique for foods using ionizing energy without impairing the products either natural characteristics or nutritive contents. Formation of free radicals and radiolytic products in irradiated foods may produce toxic substances, mutagen or carcinogenic that can affect the consumer health. Toxicity test as a part of food safety assays on gold fish (Cyprinus carpio ) pepes in a package and irradiated at the dose of 45 kGy under cryogenic condition was conducted through lymphocyte proliferation because lymphocyte cell is responsible for specific immune response and sensitive to unbalance condition between oxidant and anti oxidant in human body. Malonaldehyde content in the irradiated fish was also measured bearing in mind that malonaldehyde content could be used as indicator in the presence of free radicals and as oxidative damage indicator within the matrix of biological material. Dilution steps was done in all samples both in control and irradiated. Irradiation was conducted at three different times i.e., sample irradiated on 11 November 2006 (A), 14 June 2007(B), 5 April 2008 (C) and in 2008 (code: “no label”) (D), respectively. Proliferation of lymphocyte cell was assayed based on Stimulation Index value (SI), and free radical content of all samples was calculated based on malonaldehyde content (pmol/ml). The measurement of SI in sample without dilution showed that the highest value was found in sample B (1.356), but the lowest value was obtained in control (1.161); at one time dilution the highest value was obtained in sample D (1.344), the lowest was found in sample B (1.084) compared to control (1.259). At twice time dilution, the highest value was found in control (1.293), but the lowest was in sample D (0.984). The results of malonaldehyde content (pmol/ml) showed that sample without dilution has the highest quantity was found in sample A (0.1182 pmol/ml), but the lowest was in sample C (0.1178 pmol/ml) for

Cytogenetic Low-Dose Hyperradiosensitivity Is Observed in Human Peripheral Blood Lymphocytes

Energy Technology Data Exchange (ETDEWEB)

Seth, Isheeta [Department of Biological Sciences, Wayne State University, Detroit, Michigan (United States); Joiner, Michael C. [Department of Radiation Oncology, Wayne State University, Detroit, Michigan (United States); Tucker, James D., E-mail: jtucker@biology.biosci.wayne.edu [Department of Biological Sciences, Wayne State University, Detroit, Michigan (United States)

2015-01-01

Purpose: The shape of the ionizing radiation response curve at very low doses has been the subject of considerable debate. Linear-no-threshold (LNT) models are widely used to estimate risks associated with low-dose exposures. However, the low-dose hyperradiosensitivity (HRS) phenomenon, in which cells are especially sensitive at low doses but then show increased radioresistance at higher doses, provides evidence of nonlinearity in the low-dose region. HRS is more prominent in the G2 phase of the cell cycle than in the G0/G1 or S phases. Here we provide the first cytogenetic mechanistic evidence of low-dose HRS in human peripheral blood lymphocytes using structural chromosomal aberrations. Methods and Materials: Human peripheral blood lymphocytes from 2 normal healthy female donors were acutely exposed to cobalt 60 γ rays in either G0 or G2 using closely spaced doses ranging from 0 to 1.5 Gy. Structural chromosomal aberrations were enumerated, and the slopes of the regression lines at low doses (0-0.4 Gy) were compared with doses of 0.5 Gy and above. Results: HRS was clearly evident in both donors for cells irradiated in G2. No HRS was observed in cells irradiated in G0. The radiation effect per unit dose was 2.5- to 3.5-fold higher for doses ≤0.4 Gy than for doses >0.5 Gy. Conclusions: These data provide the first cytogenetic evidence for the existence of HRS in human cells irradiated in G2 and suggest that LNT models may not always be optimal for making radiation risk assessments at low doses.

Recommendations for the use of irradiated components

International Nuclear Information System (INIS)

2007-01-01

The disease 'graft-versus-host' associated with the transfusion (EIVH TA) is an adverse reaction rare but fatal, linked to the proliferation of T cells that are found in cellular components and reacting against the receptor's tissues). Gamma irradiation of cellular components is used as a prevention method because it deactivates the lymphocytes T by reducing its survival and by restraining its proliferation without producing alterations in others cells function. Recommendations for the use of gamma irradiation along with clinical indications for pediatric patients, patients with acquired immunosuppression and immunocompetent patients are given in this study. A brief description of operative aspects of irradiation procedures such as components to be irradiated, irradiation method, irradiation dose and viability of irradiated components is given [es

Microbiological and biochemical response of certain proteolytic bacterial isolates to varying levels of gamma irradiation

International Nuclear Information System (INIS)

El-Hifnawi, H.M.N.E.A.

1997-01-01

Amniotic membrane allo - and xeno grafts prepared from human foetal placenta, and their potential replacement of skin autotransplant, would significantly contribute to the success of clinical treatment of skin burns. Allo-and xenografts of human amniotic membrane should be ensured for their sterility, bio-mechanics and tissue antigenicity. The present study has been focused on sterilization and sterility assurance of the membrane grafts. Physico-chemical properties and antigenicity of the grafts await investigation. In the present study the isolation and identification of the bacteria contaminating the amniotic membrane allo-and xenografts prepared from human foetal placenta and the effect of gamma irradiation on it has been investigated. The proteolytic activity of these bacteria and the role of gamma irradiation in the control of bacterial activity were similarly investigated

Biological Dosimetry of In Vitro Irradiation with Radionuclides : Comparison of Whole Blood, Lymphocyte and Buffy Coat Culture

International Nuclear Information System (INIS)

Kim, Jong Ho; Lee, Dong Soo; Choi, Chang Woon; Chung, June Key; Lee, Myung Chul; Koh, Chang Soon; Kim, Chong Soon; Kim, Hee Geun; Kang, Duck Won; Song, Myung Jae

1995-01-01

The purpose of this study was to establish mononuclear cell cultures such as lymphocytes or buffy coat for the biological dosimetry of in vitro irradiation of the radionuclide Tc-99m in order to exclude the effect of residual doses seen in the cultures of whole blood. Biological dosimetry of Tc-99m on cultured mononuclear cells at doses ranging from 0.05 to 6.00 Gy, by scoring unstable chromosomal aberrations(Ydr) observed in cultured lymphocytes, were performed using peripheral venous blood of healthy normal person. The results showed that; (1) In vitro irradiation of radioisotope in separated lymphocyte or buffy coat showed trace amount af residual doses of isotope after washing. Residual doses of isotopes are increased in proportion tn exposed time and irradiated dose without difference between I-131 anct Tc-99m. (2) We obtained these linear-quadratic dose response equations in lymphocyte and buffy coat culture after in vitro irradiation of Tc-99m, respectively (Ydr = 0,001949 D 2 +0,006279D+ 0.000185; Ydr= 0.002531 D 2 -0.003274 D+0.003488). In conclusion, the linear quadrstic dose response equation from in vitro irradiation of Tc-99m with lymphocyte and buffy coat culture was thought to be useful for assessing Tc-99m indueed biological effects. And mononuclear cell cultures seem to be the most appropriate experimental model for the assessment of biological dosimetry of internal irradiation of radionuclides.

Termite feeding preference to four wood species after gamma irradiation

International Nuclear Information System (INIS)

Katsumata, N.; Yoshimura, T.; Tsunoda, K.; Imamura, Y.

2007-01-01

The effect of gamma irradiation at 100 kGy and at lower levels on termite resistance was examined in the laboratory by no-choice and choice feeding termite tests (Coptotermes formosanus Shiraki) using four wood species: sapwood of Cryptomeria japonica D. Don, and heartwoods of Pseudotsuga menziesii (Mirbel) Franco, Larix kaempferi (Lambert) Carriere, and Chamaecyparis obtusa Endl. The wood consumption rates in C. japonica and P. menziesii specimens were likely to increase with increases in gamma-irradiation levels, whereas little effect of gamma irradiation was seen in L. kaempferi and C. obtusa. Similar results were obtained in the two-choice test. The current results indicated that in the two-choice test with C. formosanus, 100-kGy-irradiated C. japonica and P. menziesii, which are not rich in antitermite substances, were eaten more than other wood samples with or without gamma irradiation. However, only C. japonica showed significant difference in termite feeding activity. The mass loss in 100-kGy-irradiated C. japonica was significantly higher in the multichoice test

The improvement of corn starch isolation process by gamma irradiation

International Nuclear Information System (INIS)

Byun, M.W.; Kang, I.J.; Kwon, J.H.; Lee, S.J.; Kim, S.K.

1995-01-01

Gamma irradiation was applied to non-glutinous and glutinous corns for improving starch isolation process. No significant changes in proximate composition of corn grains were observed by gamma irradiation. Irradiation at 1 and 5 kGy was effective for sterilizing all contaminated microorganisms of non-glutinous and glutinous corns, respectively. The moisture-uptake rate constants were increased in proportional to the steeping temperature and applied irradiation dose level. The irradiation efficacy on water absorption properties was also recognized in the corns stored for six months at room temperature. The combined use of gamma irradiation with sulfur dioxide solution was very effective for reducing steeping time. The starch yield gradually increased as irradiation dose levels increased. At 2 kGy, the sarch yield of non-glutinous and glutinous corns increased by 38% and 27%, respectively. No significant difference in Hunter's color value was observed between the starches isolated from nonirradiated and irradiated corn grains

Radiation protection in category III large gamma irradiators

International Nuclear Information System (INIS)

Costa, Neivaldo; Furlan, Gilberto Ribeiro; Itepan, Natanael Marcio

2011-01-01

This article discusses the advantages of category III large gamma irradiator compared to the others, with emphasis on aspects of radiological protection, in the industrial sector. This category is a kind of irradiators almost unknown to the regulators authorities and the industrial community, despite its simple construction and greater radiation safety intrinsic to the model, able to maintain an efficiency of productivity comparable to those of category IV. Worldwide, there are installed more than 200 category IV irradiators and there is none of a category III irradiator in operation. In a category III gamma irradiator, the source remains fixed in the bottom of the tank, always shielded by water, negating the exposition risk. Taking into account the benefits in relation to radiation safety, the category III large irradiators are highly recommended for industrial, commercial purposes or scientific research. (author)

Hypothermia postpones DNA damage repair in irradiated cells and protects against cell killing

Energy Technology Data Exchange (ETDEWEB)

Baird, Brandon J.; Dickey, Jennifer S.; Nakamura, Asako J.; Redon, Christophe E.; Parekh, Palak [Laboratory of Molecular Pharmacology, CCR, NCI, Bethesda, MD 20892 (United States); Griko, Yuri V. [Radiation and Space Biotechnology Branch, NASA Ames Research Center, Moffett Field, CA 94035 (United States); Aziz, Khaled; Georgakilas, Alexandros G. [Biology Department, East Carolina University, Greenville, NC 27858 (United States); Bonner, William M. [Laboratory of Molecular Pharmacology, CCR, NCI, Bethesda, MD 20892 (United States); Martin, Olga A., E-mail: sedelnio@mail.nih.gov [Laboratory of Molecular Pharmacology, CCR, NCI, Bethesda, MD 20892 (United States)

2011-06-03

Hibernation is an established strategy used by some homeothermic organisms to survive cold environments. In true hibernation, the core body temperature of an animal may drop to below 0 {sup o}C and metabolic activity almost cease. The phenomenon of hibernation in humans is receiving renewed interest since several cases of victims exhibiting core body temperatures as low as 13.7 {sup o}C have been revived with minimal lasting deficits. In addition, local cooling during radiotherapy has resulted in normal tissue protection. The experiments described in this paper were prompted by the results of a very limited pilot study, which showed a suppressed DNA repair response of mouse lymphocytes collected from animals subjected to 7-Gy total body irradiation under hypothermic (13 {sup o}C) conditions, compared to normothermic controls. Here we report that human BJ-hTERT cells exhibited a pronounced radioprotective effect on clonogenic survival when cooled to 13 {sup o}C during and 12 h after irradiation. Mild hypothermia at 20 and 30 {sup o}C also resulted in some radioprotection. The neutral comet assay revealed an apparent lack on double strand break (DSB) rejoining at 13 {sup o}C. Extension of the mouse lymphocyte study to ex vivo-irradiated human lymphocytes confirmed lower levels of induced phosphorylated H2AX ({gamma}-H2AX) and persistence of the lesions at hypothermia compared to the normal temperature. Parallel studies of radiation-induced oxidatively clustered DNA lesions (OCDLs) revealed partial repair at 13 {sup o}C compared to the rapid repair at 37 {sup o}C. For both {gamma}-H2AX foci and OCDLs, the return of lymphocytes to 37 {sup o}C resulted in the resumption of normal repair kinetics. These results, as well as observations made by others and reviewed in this study, have implications for understanding the radiobiology and protective mechanisms underlying hypothermia and potential opportunities for exploitation in terms of protecting normal tissues against

Influence of Gamma-Irradiation on the Growth of Aspergillus spp. on Feeds for Ensuring Feed Safety

International Nuclear Information System (INIS)

Kim, J.S.; Woo, J.H.; Kim, J.T.; Park, N.H.; Kim, C.G.

2010-01-01

Aspergillus spp. is widely spread in the world on feeds and foods. They have been known to produce aflatoxins, which are mutagenic and carcinogenic to humans. The objective of this study was to determine the optimum gamma-irradiation dose for controling the growth of Aspergillus spp. to ensure safety of feeds. Four species fungal spore (10∨7 spore/mL) exposed to 0, 1, 3, 5, 7 and 10 kGy of gamma radiation were inhibited in their growth and AFBâ‚ productivity by greater-than or equal to 5 kGy. Meantime, the growth of fungal inoculated on feeds was inhibited at greater-than or equal to 3 kGy. However, AFBâ‚ presented in aqueous solution was not be inactivated completely by less-than or equal to 10 kGy irradiation. These results indicate that Aspergillus spp. on feeds could be controlled by 5 kGy gamma-irradiation but detoxification of AFBâ‚ demands a higher dose of gamma-irradiation (greater-than or equal to 10 kGy)

Structural evolution of defective graphene under heat treatment and gamma irradiation

Science.gov (United States)

Zhang, Yifei; Shi, Jie; Chen, Cheng; Li, Nan; Xu, Zhiwei; Liu, Liangsen; Zhao, Lihuan; Li, Jing; Jing, Miaolei

2018-03-01

We have studied the structural change of defective graphene built by annealing in different temperature under the condition of gamma irradiation. Firstly, we found the heat treatment not only reduced but also striped the graphene. This behavior made defects become more firstly and then become less with the increase of temperature. And then gamma irradiation removed some oxygen-containing groups, by a simultaneous changed over carbon in the graphitic lattice from sp3 to sp2. Also, the gamma irradiation decreased the interlayer spacing between graphene lowest to 3.391 Å and made a crosslink which resulting in the size of the ordered gaining. A variation was detected by Raman spectroscopy that the amorphous carbon was declined after gamma irradiation. Furtherly we found the degree of this decline raised first and then diminished with the increase in the number of defects. The change in repair capacity of gamma irradiation presented a strategy for repairing the defects of graphene.

Gamma irradiation influence on physical properties of milk proteins

International Nuclear Information System (INIS)

Ciesla, K.; Salmieri, S.; Lacroix, M.; Le Tien, C.

2004-01-01

Gamma irradiation was found to be an effective method for the improvement of both barrier and mechanical properties of the edible films and coatings based on calcium and sodium caseinates alone or combined with some globular proteins. Our current studies concern gamma irradiation influence on the physical properties of calcium caseinate-whey protein isolate-glycerol (1:1:1) solutions and gels, used for films preparation. Irradiation of solutions was carried out with Co-60 gamma rays applying 0 and 32 kGy dose. The increase in viscosity of solutions was found after irradiation connected to induced crosslinking. Lower viscosity values were detected, however, after heating of the solutions irradiated with a 32 kGy dose than after heating of the non-irradiated ones regarding differences in the structure of gels and resulting in different temperature-viscosity curves that were recorded for the irradiated and the non-irradiated samples during heating and cooling. Creation of less stiff but better ordered gels after irradiation arises probably from reorganisation of aperiodic helical phase and β-sheets, in particular from increase of β-strands, detected by FTIR. Films obtained from these gels are characterised by improved barrier properties and mechanical resistance and are more rigid than those prepared from the non-irradiated gels. The route of gel creation was investigated for the control and the irradiated samples during heating and the subsequent cooling

Gamma irradiation influence on physical properties of milk proteins

Energy Technology Data Exchange (ETDEWEB)

Ciesla, K. E-mail: kciesla@orange.ichtj.waw.pl; Salmieri, S.; Lacroix, M.; Le Tien, C

2004-10-01

Gamma irradiation was found to be an effective method for the improvement of both barrier and mechanical properties of the edible films and coatings based on calcium and sodium caseinates alone or combined with some globular proteins. Our current studies concern gamma irradiation influence on the physical properties of calcium caseinate-whey protein isolate-glycerol (1:1:1) solutions and gels, used for films preparation. Irradiation of solutions was carried out with Co-60 gamma rays applying 0 and 32 kGy dose. The increase in viscosity of solutions was found after irradiation connected to induced crosslinking. Lower viscosity values were detected, however, after heating of the solutions irradiated with a 32 kGy dose than after heating of the non-irradiated ones regarding differences in the structure of gels and resulting in different temperature-viscosity curves that were recorded for the irradiated and the non-irradiated samples during heating and cooling. Creation of less stiff but better ordered gels after irradiation arises probably from reorganisation of aperiodic helical phase and {beta}-sheets, in particular from increase of {beta}-strands, detected by FTIR. Films obtained from these gels are characterised by improved barrier properties and mechanical resistance and are more rigid than those prepared from the non-irradiated gels. The route of gel creation was investigated for the control and the irradiated samples during heating and the subsequent cooling.

Study on effects of gamma-ray irradiation on TlBr semiconductor detectors

International Nuclear Information System (INIS)

Matsumura, Motohiro; Watanabe, Kenichi; Yamazaki, Atsushi; Uritani, Akira; Kimura, Norihisa; Nagano, Nobumichi; Hitomi, Keitaro

2016-01-01

Radiation hardness of thallium bromide (TlBr) semiconductor detectors to 60 Co gamma-ray irradiation was evaluated. The energy spectra and μτ products of electrons were measured to evaluate the irradiation effects. No significant degradation of spectroscopic performance of the TlBr detector for 137 Cs gamma-rays was observed up to 45 kGy irradiation. Although the μτ products of electrons in the TlBr detector slightly decreased, position of the photo-peak was stable without significant degradation after the gamma-ray irradiation. We confirmed that the TlBr semiconductor detector has a high tolerance for gamma-ray irradiation at least up to 45 kGy. (author)

ESR investigations of gamma irradiated beryllium ceramics

International Nuclear Information System (INIS)

Ryabikin, Yu.A.; Polyakov, A.I.; Petukhov, Yu.V.; Bitenbaev, M.I.; Zashkvara, O.V.

2000-01-01

In this report the result of ESR- investigation of kinetics of radiation paramagnetic defects accumulated in beryllium ceramics under gamma irradiation are presented. The data on quantum yield and destruction rate constants of these defects under ionizing irradiation are obtained. (orig.)

ESR investigations of gamma irradiated beryllium ceramics

Energy Technology Data Exchange (ETDEWEB)

Ryabikin, Yu A; Polyakov, A I; Petukhov, Yu V; Bitenbaev, M I; Zashkvara, O V [Physical-Technical Inst., Almaty (Kazakhstan)

2000-04-01

In this report the result of ESR- investigation of kinetics of radiation paramagnetic defects accumulated in beryllium ceramics under gamma irradiation are presented. The data on quantum yield and destruction rate constants of these defects under ionizing irradiation are obtained. (orig.)

Prevention Effect of Poly-Gamma-Glutamic Acid on Tissue Damage Induced by Gamma Irradiation as a Natural Cross-Linker

Energy Technology Data Exchange (ETDEWEB)

Kim, Jaehun; Sung, Nakyun; Kim, Jeongsoo; Jo, Euri; Choi, Jongil; Park, Jongheum; Lee, Juwoon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Lee, Kwangwon [Eulji Univ. Hospital, Daejeon (Korea, Republic of); Kwon, Jungkee [Chonbuk National Univ., Jeonju (Korea, Republic of); Kim, Taewoon [Jeonbuk Technopark, Jeonju (Korea, Republic of)

2012-03-15

This study was to determine the prevention effect of poly-gamma-glutamic acid (PGA) on tissue damage induced by gamma irradiation for development of xenograft. PGA (MW 2000 kDa) extracted from permeated soy bean (natto) was used in this study as natural compound, and glutaraldehyde (GA) and 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) were used as a control, chemical based cross-linking agents. GA, EDC and PGA treated porcine tendons were gamma-irradiated at the dose of 30 kGy. Prevention effects against tissue damage were measured as the result of tensile strength, hydroxyproline contents and tissue morphological analysis. Tensile of porcine tendon was remarkably decreased by gamma irradiation, but increased in PGA treated group. Morphological analysis showed that collagen structure was broken by gamma irradiation, but attenuated by PGA treatment. Base on the results, it demonstrated that gamma irradiation can induce severe alteration of porcine tendon, but PGA can effectively improve the tissue damage.

Prevention Effect of Poly-Gamma-Glutamic Acid on Tissue Damage Induced by Gamma Irradiation as a Natural Cross-Linker

International Nuclear Information System (INIS)

Kim, Jaehun; Sung, Nakyun; Kim, Jeongsoo; Jo, Euri; Choi, Jongil; Park, Jongheum; Lee, Juwoon; Lee, Kwangwon; Kwon, Jungkee; Kim, Taewoon

2012-01-01

This study was to determine the prevention effect of poly-gamma-glutamic acid (PGA) on tissue damage induced by gamma irradiation for development of xenograft. PGA (MW 2000 kDa) extracted from permeated soy bean (natto) was used in this study as natural compound, and glutaraldehyde (GA) and 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) were used as a control, chemical based cross-linking agents. GA, EDC and PGA treated porcine tendons were gamma-irradiated at the dose of 30 kGy. Prevention effects against tissue damage were measured as the result of tensile strength, hydroxyproline contents and tissue morphological analysis. Tensile of porcine tendon was remarkably decreased by gamma irradiation, but increased in PGA treated group. Morphological analysis showed that collagen structure was broken by gamma irradiation, but attenuated by PGA treatment. Base on the results, it demonstrated that gamma irradiation can induce severe alteration of porcine tendon, but PGA can effectively improve the tissue damage

Gamma-irradiation activates biochemical systems: induction of nitrate reductase activity in plant callus.

OpenAIRE

Pandey, K N; Sabharwal, P S

1982-01-01

Gamma-irradiation induced high levels of nitrate reductase activity (NADH:nitrate oxidoreductase, EC 1.6.6.1) in callus of Haworthia mirabilis Haworth. Subcultures of gamma-irradiated tissues showed autonomous growth on minimal medium. We were able to mimic the effects of gamma-irradiation by inducing nitrate reductase activity in unirradiated callus with exogenous auxin and kinetin. These results revealed that induction of nitrate reductase activity by gamma-irradiation is mediated through i...

Preservation of potatoes by gamma irradiation

International Nuclear Information System (INIS)

Nouani, A.; Boussaha, A.

1987-01-01

In Algeria, potatoes are a major food item in nutrition habits. Because of lack of cold storage facilities, losses can reach up to 40% of the total output of summer harvest. This paper describes the first experiments on the application of gamma irradiation for the preservation of local varieties of potatoes. Losses are strongly reduced by inhibition sprouting effect of irradiation and reduction of sugars content has no significant influence on the acceptability of irradiated potatoes

RADIOPROTECTIVE EFFECT OF LYCOPENE IN GAMMA IRRADIATED ALBINO RATS

International Nuclear Information System (INIS)

MOHAMED, M.I.; ALI, S.E.; HAGGAG, A.M.

2007-01-01

The present study was designed to explore the radioprotective potential of lycopene in gamma irradiated male rats. Four groups, each of sixteen rats, were assigned as follows: the first was untreated (control group), the second fed on chow diet mixed with 300 mg lycopene/kg diet (lycopene group), the third exposed to 6.5 Gy gamma radiation (irradiated group) and the fourth fed on chow mixed with 300 mg lycopene/kg and exposed to 6.5 Gy gamma radiation (irradiated and treated group). Animals exposed to ionizing radiation experienced decline in their body weights, increased ALT and AST enzymes and decreased serum albumin level. The study also showed decline in hemoglobin, total white blood cells count and blood platelets count. Bone marrow examination revealed profound hypoplasis and reduction of the cellular elements. Histological examination of liver, spleen, testis and intestine showed disruption of normal architecture of these organs. Irradiated and treated animals maintained a more or less steady body weight, and improved serum ALT, AST and albumin in comparison with those irradiated. The results also showed increased hemoglobin, total white blood cells, platelets count and partial improvement of bone marrow cellularity. Lycopene was also capable of partial preservation of normal architecture of liver, spleen, intestine and testis in gamma irradiated group.In conclusion, lycopene seems to be a useful radioprotector probably because of its potent antioxidant property

Effect of autoclave processing and gamma irradiation on apparent ...

African Journals Online (AJOL)