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Sample records for irradiated cells underwent

  1. The effects of transfusion of irradiated blood upon cellular immune response in patients underwent open heart surgery

    International Nuclear Information System (INIS)

    Togashi, Ken-ichi; Nakazawa, Satoshi; Moro, Hisanaga; Yazawa, Masatomo; Kanazawa, Hiroshi; Hayashi, Jun-ichi; Yamazaki, Yoshihiko; Eguchi, Shoji

    1989-01-01

    The purpose of this paper is to demonstrate the effect of the transfusion of blood received 1500 rad exposure upon the immune response in 14 patients underwent various type of cardiac surgery. 13 patients received known amounts banked blood and irradiated fresh blood, while one patient received a lot of amounts of banked and irradiated and non-irradiated fresh blood. The authors studied the numbers of lymphocytes as well as lymphocyte subsets such as pan-T cells, B cells, helper/inducer T cells (T H/I ), cytotoxic/supressor T cells (T C/S ), active T cells, natural killer (NK) cells and NK cell activity during two weeks after surgeries. In all 14 patients, pan-T lymphocytes decreased markedly in a few days after surgeries, but increased to higher levels on the eight postoperative day than the levels preoperatively. T H/I and T C/S lymphocytes changed on the similar pattern as pan-T lymphocytes. Active T and B cells did not change significantly in two weeks. The number and activity of NK cells gave the lowest levels on the second postoperative day and did not recovery to the preoperative levels in two weeks. One patient received non-irradiated fresh blood showed the similar immune response as other 13 patients, while he gave the lower levels than others did. This patient died of graft-versus-host disease (GVHD)-like syndrome on the 36th postoperative day. It may be thought that the transfusion of irradiated blood would prevent the host from GVHD and gave the better effects on the immune response than that of non-irradiated blood following open-heart surgeries. (author)

  2. Cell cycle evaluation of granulosa cells in the {gamma}-irradiated mouse ovarian follicles

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    KIm, Jin Kyu; Lee, Chang Joo; Lee, Young Keun [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of); Song, Kang Won; Yoon, Yong Dal [Hanyang Univ., Seoul (Korea, Republic of)

    1999-03-01

    This study was carried out to evaluate the biochemical and morphological effects of ionizing radiation on mouse ovarian follicles. Immature mice (ICR, 3 week-old) were irradiated with a dose of LD{sub 80(30)} at KAERI. The ovaries were collected after 6 hours, 12 hours, 1 day, and 2 days post irradiation. With the morphological basis of the histological staining with hematoxylin-eosin, immunohistochemical preparation using in situ 3'-end labeling was evaluated. Flow cytometric evaluation of DNA extracted from the whole ovary was performed. The percentage of A{sub 0} (subpopulation of cells with degraded DNA and with lower DNA fluorescence than G{sub 0}/G{sub 1} cells), apoptotic, cells in the cell cycle was significantly higher in the irradiated group than in the control group. The number of in situ 3'-end labeled follicles increased at 6 hours post irradiation. All the analyses represented that the ionizing radiation-induced follicular atresia was taken place via an apoptotic degeneration. Such a degeneration underwent very fast and acutely. Therefore, it is concluded that the radiation-induced follicular degeneration is, like the spontaneous atresia, mediated by an acute apoptosis of follicular granulosa cells. Flow cytometric evaluation of cell cycles can make the role for quantifying the atretic follicles and understanding the mechanism of the radiation-induced cell death.

  3. Influence of operation and irradiation on cell-mediated immunity in patients with oral cancer

    International Nuclear Information System (INIS)

    Tominaga, Kazuhiro; Tominaga, Naohiro; Tokuhisa, Michio

    1995-01-01

    To evaluate the influence of operation and irradiation on cell-mediated immunity in patients with primary oral squamous cell carcinoma, several parameters, including NK activity, LAK activity, and IL-2 production, were selected. Twenty-two patients who underwent operation and/or irradiation from 1989 to 1993 were evaluated. Perioperatively, no significant change of immunologic parameters was observed except increased number of peripheral leukocytes at two weeks after operation. Immediately and/or one month after irradiation, significantly decreased numbers of leukocytes and lymphocytes as well as significantly depressed levels of blastoid transformation of lymphocytes, LAK activity, and IL-2 production were observed. By three months after irradiation, values of immunologic parameters returned to preirradiation values. The number of monocytes and level of NK activity showed little change after irradiation. (author)

  4. Adaptation and possible attenuation of Theileria parva-infected cells grown in irradiated mice

    International Nuclear Information System (INIS)

    Irvin, A.D.; Brown, C.G.D.; Stagg, D.A.; Kanhai, G.K.; Kimber, C.D.; Radley, D.E.

    1976-01-01

    Theileria parva-infected bovine lymphoid cells were taken from 8 cattle immediately after death from East Coast fever (ECF). Cells were inoculated into groups of irradiated Swiss and athymic nude mice. The irradiated mice were exposed to 800 rad doses from a 60 Co source. Cells became established in one group of Swiss mice and 2 groups of athymic mice. Development of cells in mice only occurred if cells concurrently established in culture; when establishment in culture was delayed, cells failed to develop in mice. Cells from one of the isolates in athymic mice were passaged 6 times through further mice. On inoculation of these mouse-passaged cells into cattle, the animals underwent mild reactions and subsequently resisted a lethal ECF challenge. The possibility of vaccinating cattle aginst ECF by means of mouse passaged cells merits further study. (author)

  5. Radiation Effect on Secondary Cancerization by Tumour Cell Grafts. Take of Irradiated Tumour Cells in Irradiated and Non-Irradiated Animals

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    Costachel, O.; Sandru, Gh.; Kitzulescu, I. [Oncological Institute, Bucharest (Romania)

    1969-11-15

    This study was designed to determine the ability of haemocytoblastoma, SME and Jensen tumours, which had been irradiated in vitro, to take in C{sub 57}BL/6 mice or Wistar rats that were whole-body irradiated at 0.4 kR and 0.6 kR respectively. It was found-that the take of tumour cell grafts irradiated in vitro increased in whole-body irradiated mice and rats but not in non-irradiated ones. When Wistar rats, that had been whole-body irradiated with 0.7 and 0.8 kR 1 - 7 months earlier and survived after treatment, were grafted with Jensen tumour cells irradiated in vitro with 3 kR they were found to develop tumours and lung metastases (in contrast to non-irradiated rats). A cross resistance against non-irradiated Jensen tumour cells was obtained in non- irradiated Wistar rats by grafting irradiated Jensen tumour cells. Chromosomal analysis showed two supplementary giant markers in the Jensen tumour cells that had been irradiated in vitro before grafting. (author)

  6. Stem cell migration after irradiation

    International Nuclear Information System (INIS)

    Nothdurft, W.; Fliedner, T.M.

    1979-01-01

    The survival rate of irradiated rodents could be significantly improved by shielding only the small parts of hemopoietic tissues during the course of irradiation. The populations of circulating stem cells in adult organisms are considered to be of some importance for the homeostasis between the many sites of blood cell formation and for the necessary flexibility of hemopoietic response in the face of fluctuating demands. Pluripotent stem cells are migrating through peripheral blood as has been shown for several mammalian species. Under steady state conditions, the exchange of stem cells between the different sites of blood cell formation appears to be restricted. Their presence in blood and the fact that they are in balance with the extravascular stem cell pool may well be of significance for the surveilance of the integrity of local stem cell populations. Any decrease of stem cell population in blood below a critical size results in the rapid immigration of circulating stem cells in order to restore local stem cell pool size. Blood stem cells are involved in the regeneration after whole-body irradiation if the stem cell population in bone marrows is reduced to less than 10% of the normal state. In the animals subjected to partial-body irradiation, the circulating stem cells appear to be the only source for the repopulation of the heavily irradiated, aplastic sites of hemopoietic organs. (Yamashita, S.)

  7. Cytologic studies on irradiated gestric cancer cells

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    Isono, S; Takeda, T; Amakasu, H; Asakawa, H; Yamada, S [Miyagi Prefectural Adult Disease Center, Natori (Japan)

    1981-06-01

    The smears of the biopsy and resected specimens obtained from 74 cases of irradiated gastric cancer were cytologically analyzed for effects of irradiation. Irradiation increased the amount of both necrotic materials and neutrophils in the smears. Cancer cells were decreased in number almost in inverse proportion to irradiation dose. Clusters of cancer cells shrank in size and cells were less stratified after irradiation. Irradiated cytoplasms were swollen, vacuolated and stained abnormally. Irradiation with less than 3,000 rads gave rise to swelling of cytoplasms in almost all cases. Nuclei became enlarged, multiple, pyknotic and/or stained pale after irradiation. Nuclear swelling was more remarkable in cancer cells of differentiated adenocarcinomas.

  8. Effects of low priming dose irradiation on cell cycle arrest of HepG2 cells caused by high dose irradiation

    International Nuclear Information System (INIS)

    Xia Jingguang; Jin Xiaodong; Chinese Academy of Sciences, Beijing; Li Wenjian; Wang Jufang; Guo Chuanling; Gao Qingxiang

    2005-01-01

    Human hepatoma cells hepG2 were irradiated twice by 60 Co γ-rays with a priming dose of 5 cGy and a higher dose of 3 Gy performed 4h or 8h after the low dose irradiation. Effects of the priming dose irradiation on cell cycle arrest caused by high dose were examined with flow cytometry. Cells in G 2 /M phase accumulated temporarily after the 5 cGy irradiation, and proliferation of tumor cells was promoted significantly by the low dose irradiation. After the 3 Gy irradiation, G 2 phase arrest occurred, and S phase delayed temporally. In comparison with 3 kGy irradiation only, the priming dose delivered 4h prior to the high dose irradiation facilitated accumulation of hepG2 cells in G 2 /M phase, whereas the priming dose delivered 8h prior to the high dose irradiation helped the cells to overcome G 2 arrest. It was concluded that effects of the priming dose treatment on cell cycle arrest caused by high dose irradiation were dependent on time interval between the two irradiations. (authors)

  9. Changes in T-cell count in patients undergoing radiotherapy. With particular reference to preoperative irradiation for gastric carcinoma

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    Makino, K; Sato, S [Tokyo Medical Coll. (Japan)

    1980-01-01

    To know changes in immunological competence of T-cells induced by radiotherapy, T-cells in peripheral blood of patients who underwent radiotherapy were observed before, during, and 6 months after the irradiation. The subjects were 69 patients having malignant tumors including 20 with gastric cancer, 15 with breast cancer, and 9 with colon cancer. 200 rad of an exposure dose was irradiated for successive 5 to 6 days. A total of exposure doses ranged from 2,000 to 10,000 rad. T-cell count decreased markedly until exposure doses reached 3,000 rad, but its decrease was mild after exposure doses were over 3,000 rad. T-cell count decreased slightly in patients whose head and neck were irradiated, but it decreased markedly in patients whose thorax and abdomen were irradiated. Therefore, it was thought that there was a relationship between exposed sites and the decrease in T-cell count. T-cell count decreased markedly when irradiation field was wide. The smaller exposure doses were, the earlier the recovery of T-cell were. T-cells irradiated with over 7,000 rad did not recover within 6 months after the irradiation. The recovery of T-cells in patients with gastric cancer who did not undergo gastrectomy was markedly worse than that in patients who had gastrectomy. Patterns of changes in T-cell count were divided into 4 (ascending curve, U-type curve, flat curve, and descending curve), and prognosis of patients were discussed. There was a clear difference in prognosis of patients among four patterns.

  10. Cell Morphology Change by the Ultraviolet Ray Irradiation

    International Nuclear Information System (INIS)

    Park, Myung Joo; Matuo, Yoichirou; Akiyama, Yoko; Izumi, Yoshinobu; Nishijima, Shigehiro

    2009-01-01

    The effect of low doses of ultraviolet (UV) irradiation on morphology changes of cell has been studied based on the observation of the cell length. It was shown that UV-irradiated cell has different behavior in comparison with nonirradiated cell. From the histogram of cell-length distribution, it was confirmed that cell cycle of non irradiated cell was 28 hours, and that cell cycle of irradiated cell with dose of 20 Jm -2 was delayed (39 hours), while irradiated cell with 40 Jm -2 and 60 Jm -2 did not divide and kept growing continuously. It was supposed that in case of 20 Jm -2 of irradiation dose, the cell cycle was delayed because the checkpoint worked in order to repair DNA damage induced by generation of pyrimidine dimer, reactive oxygen species and so on. It was also supposed that in case of 40 Jm -2 and 60 Jm -2 of irradiation dose, overgrowth was induced because the checkpoint was not worked well. The morphology of overgrown cell was similar to that of normally senescent cell. Therefore, it was considered that cell senescence was accelerated by UV irradiation with irradiation doses of 40 Jm -2 and 60 Jm -2

  11. Interaction of X-irradiated mouse cells in heterokaryons

    International Nuclear Information System (INIS)

    Hofmanova, J.; Spurna, V.

    1985-01-01

    The frequency of heterokaryon formation and the ability of DNA synthesis in the system of mouse X-irradiated L fibroblasts and non-irradiated or irradiated LS/BL lymphosarcoma cells were studied. The frequency of heterokaryons after fusion of one or both irradiated parental cells was 3 to 6 times higher than in the non-irradiated cell cultures. In these heterokaryons we found 1.5 to 3 times more nuclei of irradiated L cells capable of DNA synthesis than in the population of non-fused irradiated cells. (author)

  12. Modification of cell growth rate by irradiation

    International Nuclear Information System (INIS)

    Itoh, Hisao; Takemasa, Kazuhiko; Nishiguchi, Iku; Ka, Wei-Jei; Kutsuki, Shoji; Hashimoto, Shozo

    1993-01-01

    The effect of irradiation on the proliferation kinetics of the monolayer cells has been studied. Two human cell lines with different doubling times (HeLa-P and RMUG) and two clones that have the same radiosensitivity but different doubling times (HeLa-R and HeLa-S) were irradiated with a daily dose of 2 Gy for 6 days. The number of the clonogenic cells/dish was calculated by multiplying the number of total cell/dish by the survival fraction. In the rapidly growing cells (HeLa-P, HeLa-R), the number of the clonogenic cells was not decreased by the first two fractionated irradiations, but decreased thereafter at a similar rate as by single-dose fractionation, whereas the clonogenic cell number decreased from the first fractionated irradiation in the slowly growing cells (RMUG, HeLa-S). When the proliferation of clonogenic cell number increased along with a similar growth rates that was seen in all other types of cells. Further, no correlation was seen between the growth rates of cells without irradiation and cells that received irradiation. This latter result suggests that the slow growth rate of non-irradiated cells may not be the predictive factor of the tumor cure and the interruption of radiotherapy may reduce the beneficial effect of this treatment even in slow growing tumors. (author)

  13. Isolation of chlamydia in irradiated and non-irradiated McCoy cells

    International Nuclear Information System (INIS)

    Johnson, L.; Harper, I.A.

    1975-01-01

    Specimens from eye and genital tract were cultured in parallel in irradiated and non-irradiated McCoy cells and the frequency of isolation of chlamydia using these culture methods was compared. There was a significant difference between the frequencies of isolation; irradiated McCoy cells produced a greater number of positive results. (author)

  14. Effect of x-irradiation on cell kinetics of esophageal membrane cells in mice

    International Nuclear Information System (INIS)

    Ando, Koichi; Tsunemoto, Hiroshi; Urano, Muneyasu; Koike, Sachiko

    1977-01-01

    Effect of x-irradiation on the cell kinetics of esophageal membrane cells was studied in C3Hf/He male mice. Experimental methods include; counting the number of basal and superficial cells, and pulse or continuous labelling by tritiated thymidine. Esophageal area was irradiated with 1000 rad of 200 kVp x-rays and cell kinetics were studied on the 5th post-irradiation day. Autoradiography revealed the shortening of the cell cycle time, specifically in G- and G- phases. Numbers of basal cells and of superficial cells were found to increase for 5 days after irradiation. Continuous labelling experiments using infusion technique demonstrated than growth fraction of irradiated basal cells was 1.0 as well as that of non-irradiated cells. It was of interest that the migration time, i.e., the time required for labelled cells to migrate from basal cell layer to superficial cell layer, was shortened approximately 1/3 of that of non-irradiated control after irradiation. Diurnal variation was observed not only in normal basal cells but also in irradiated ones, and the rate of increase of labelling index after continuous labelling was independent of the time when the labelling was started. (auth.)

  15. Effect of x irradiation on cell kinetics of esophageal membrane cells in mice

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    Ando, K; Tsunemoto, H; Urano, M; Koike, S [National Inst. of Radiological Sciences, Chiba (Japan)

    1977-05-01

    Effect of x irradiation on the cell kinetics of esophageal membrane cells was studied in C3Hf/He male mice. Experimental methods include; counting the number of basal and superficial cells, and pulse or continuous labelling by tritiated thymidine. Esophageal area was irradiated with 1000 rad of 200 kVp x rays and cell kinetics were studied on the 5th post-irradiation day. Autoradiography revealed the shortening of the cell cycle time, specifically in G- and G- phases. Numbers of basal cells and of superficial cells were found to increase for 5 days after irradiation. Continuous labelling experiments using infusion technique demonstrated than growth fraction of irradiated basal cells was 1.0 as well as that of non-irradiated cells. It was of interest that the migration time, i.e., the time required for labelled cells to migrate from basal cell layer to superficial cell layer, was shortened approximately 1/3 of that of non-irradiated control after irradiation. Diurnal variation was observed not only in normal basal cells but also in irradiated ones, and the rate of increase of labelling index after continuous labelling was independent of the time when the labelling was started.

  16. 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

  17. Reactivation of UV- and γ-irradiated herpes virus in UV- and X-irradiated CV-1 cells

    International Nuclear Information System (INIS)

    Takimoto, K.; Niwa, O.; Sugahara, T.

    1982-01-01

    Enhanced reactivation of UV- and γ-irradiated herpes virus was investigated by the plaque assay on CV-1 monkey kidney monolayer cells irradiated with UV light or X-rays. Both UV- and X-irradiated CV-1 cells showed enhancement of survival of UV-irradiated virus, while little or no enhancement was detected for γ-irradiated virus assayed on UV- or X-irradiated cells. The enhanced reactivation of UV-irradiated virus was greater when virus infection was delayed 24 or 48 h, than for infection immediately following the irradiation of cells. Thus the UV- or X-irradiated CV-1 cells are able to enhance the repair of UV damaged herpes virus DNA, but not of γ-ray damaged ones. (author)

  18. Spatio-temporal cell dynamics in tumour spheroid irradiation

    International Nuclear Information System (INIS)

    Kempf, H.; Bleicher, M.; Meyer-Hermann, M.; Kempf, H.; Bleicher, M.; Kempf, H.; Meyer-Hermann, M.

    2010-01-01

    Multicellular tumour spheroids are realistic in vitro systems in radiation research that integrate cell-cell interaction and cell cycle control by factors in the medium. The dynamic reaction inside a tumour spheroid triggered by radiation is not well understood. Of special interest is the amount of cell cycle synchronization which could be triggered by irradiation, since this would allow follow-up irradiations to exploit the increased sensitivity of certain cell cycle phases. In order to investigate these questions we need to support irradiation experiments with mathematical models. In this article a new model is introduced combining the dynamics of tumour growth and irradiation treatments. The tumour spheroid growth is modelled using an agent-based Delaunay/Voronoi hybrid model in which the cells are represented by weighted dynamic vertices. Cell properties like full cell cycle dynamics are included. In order to be able to distinguish between different cell reactions in response to irradiation quality we introduce a probabilistic model for damage dynamics. The overall cell survival from this model is in agreement with predictions from the linear-quadratic model. Our model can describe the growth of avascular tumour spheroids in agreement to experimental results. Using the probabilistic model for irradiation damage dynamics the classic 'four Rs' of radiotherapy can be studied in silico. We found a pronounced reactivation of the tumour spheroid in response to irradiation. A majority of the surviving cells is synchronized in their cell cycle progression after irradiation. The cell synchronization could be actively triggered and should be exploited in an advanced fractionation scheme. Thus it has been demonstrated that our model could be used to understand the dynamics of tumour growth after irradiation and to propose optimized fractionation schemes in cooperation with experimental investigations. (authors)

  19. Negative pion irradiation of mammalian cells

    International Nuclear Information System (INIS)

    Dertinger, H.; Luecke-Huhle, C.; Schlag, H.; Weibezahn, K.F.

    1976-01-01

    Monolayers and spheroids of Chinese hamster cells (V79) were subjected to negative pion irradiation under aerobic conditions. R.b.e. values in the pion peak of 1.8 and 1.5 were obtained for monolayers and spheroids, respectively, whereas the r.b.e. for the plateau was found to be slightly higher than 1. In addition, it was observed that the higher resistance of the V79 spheroid cells than the monolayers to γ-irradiation is not diminished in the pion peak, suggesting that the underlying phenomenon of intercellular communication influences cell survival even after high-LET irradiation. (author)

  20. Unirradiated cells rescue cells exposed to ionizing radiation: Activation of NF-κB pathway in irradiated cells

    Energy Technology Data Exchange (ETDEWEB)

    Lam, R.K.K. [Department of Physics and Materials Science, City University of Hong Kong (Hong Kong); Han, Wei [Center of Medical Physics and Technology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031 (China); Yu, K.N., E-mail: peter.yu@cityu.edu.hk [Department of Physics and Materials Science, City University of Hong Kong (Hong Kong); State Key Laboratory in Marine Pollution, City University of Hong Kong (Hong Kong)

    2015-12-15

    Highlights: • Rescue effect was observed in both irradiated and HeLa and NIH/3T3 cells. • Novel setup and procedures to separate the rescue signals and the bystander signals. • Confirmed activation of NF-κB pathway in rescue effect using activation inhibitor. • Confirmed activation of NF-κB pathway in rescue effect using anti-NF-κB p65 antibody. - Abstract: We studied the involvement of NF-κB pathway activation in the rescue effect in HeLa and NIH/3T3 cells irradiated by α particles. Firstly, upon irradiation by 5 cGy of α particles, for both cell lines, the numbers of 53BP1 foci/cell at 12 h post-irradiation were significantly smaller when only 2.5% of the cell population was irradiated as compared to 100% irradiation, which demonstrated the rescue effect. Secondly, we studied the effect of NF-κB on the rescue effect through the use of the NF-κB activation inhibitor BAY-11-7082. Novel experimental setup and procedures were designed to prepare the medium (CM) which had conditioned the bystander cells previously partnered with irradiated cells, to ensure physical separation between rescue and bystander signals. BAY-11-7082 itself did not inflict DNA damages in the cells or have effects on activation of the NF-κB response pathway in the irradiated cells through direct irradiation. The rescue effect was induced in both cell lines by the CM, which was abrogated if BAY-11-7082 was added to the CM. Thirdly, we studied the effect of NF-κB on the rescue effect through staining for phosphorylated NF-κB (p-NF-κB) expression using the anti-NF-κB p65 (phospho S536) antibody. When the fraction of irradiated cells dropped from 100% to 2.5%, the p-NF-κB expression in the cell nuclei of irradiated NIH/3T3 cells increased significantly, while that in the cell nuclei of irradiated HeLa cells also increased although not significantly. Moreover, the p-NF-κB expression in the cell nuclei of irradiated HeLa cells and NIH/3T3 cells treated with CM also increased

  1. Heavy ion irradiation induces autophagy in irradiated C2C12 myoblasts and their bystander cells

    International Nuclear Information System (INIS)

    Hino, Mizuki; Tajika, Yuki; Hamada, Nobuyuki

    2010-01-01

    Autophagy is one of the major processes involved in the degradation of intracellular materials. Here, we examined the potential impact of heavy ion irradiation on the induction of autophagy in irradiated C2C12 mouse myoblasts and their non-targeted bystander cells. In irradiated cells, ultrastructural analysis revealed the accumulation of autophagic structures at various stages of autophagy (id est (i.e.) phagophores, autophagosomes and autolysosomes) within 20 min after irradiation. Multivesicular bodies (MVBs) and autolysosomes containing MVBs (amphisomes) were also observed. Heavy ion irradiation increased the staining of microtubule-associated protein 1 light chain 3 and LysoTracker Red (LTR). Such enhanced staining was suppressed by an autophagy inhibitor 3-methyladenine. In addition to irradiated cells, bystander cells were also positive with LTR staining. Altogether, these results suggest that heavy ion irradiation induces autophagy not only in irradiated myoblasts but also in their bystander cells. (author)

  2. Immunological network activation by low-dose rate irradiation. Analysis of cell populations and cell surface molecules in whole body irradiated mice

    International Nuclear Information System (INIS)

    Ina, Yasuhiro; Sakai, Kazuo

    2003-01-01

    The effects of low-dose rate whole body irradiation on biodefense and immunological systems were investigated using female C57BL/6 (B6) mice. These B6 mice were exposed continuously to γ-rays from a 137 Cs source in the long-term low-dose rate irradiation facility at CRIEPI for 0 - 12 weeks at a dose rate of 0.95 mGy/hr. In the bone marrow, thymus, spleen, lymph nodes, and peripheral blood of the irradiated mice, changes in cell populations and cell surface molecules were examined. The cell surface functional molecules (CD3, CD4, CD8, CD19, CD45R/B220, ICAM-1, Fas, NK-1.1, CXCR4, and CCR5), and activation molecules (THAM, CD28, CD40, CD44H, CD70, B7-1, B7-2, OX-40 antigen, CTLA-4, CD30 ligand, and CD40 ligand) were analyzed by flow cytometry. The percentage of CD4 + T cells and cell surface CD8 molecule expressions on the CD8 + T cells increased significantly to 120-130% after 3 weeks of the irradiation, compared to non-irradiated control mice. On the other hand, the percentage of CD45R/B220 + CD40 + B cells, which is one of the immunological markers of inflammation, infection, tumor, and autoimmune disease, decreased significantly to 80-90% between the 3rd to 5th week of irradiation. There was no significant difference in other cell population rates and cell surface molecule expression. Furthermore, abnormal T cells bearing mutated T cell receptors induced by high-dose rate irradiation were not observed throughout this study. These results suggest that low-dose rate irradiation activates the immunological status of the whole body. (author)

  3. Irradiation strongly reduces tumorigenesis of human induced pluripotent stem cells

    International Nuclear Information System (INIS)

    Inui, Shoki; Minami, Kazumasa; Ito, Emiko; Imaizumi, Hiromasa; Mori, Seiji; Koizumi, Masahiko; Fukushima, Satsuki; Miyagawa, Shigeru; Sawa, Yoshiki; Matsuura, Nariaki

    2017-01-01

    Induced pluripotent stem (iPS) cells have demonstrated they can undergo self-renewal, attain pluripotency, and differentiate into various types of functional cells. In clinical transplantation of iPS cells, however, a major problem is the prevention of tumorigenesis. We speculated that tumor formation could be inhibited by means of irradiation. Since the main purpose of this study was to explore the prevention of tumor formation in human iPS (hiPS) cells, we tested the effects of irradiation on tumor-associated factors such as radiosensitivity, pluripotency and cell death in hiPS cells. The irradiated hiPS cells showed much higher radiosensitivity, because the survival fraction of hiPS cells irradiated with 2 Gy was < 10%, and there was no change of pluripotency. Irradiation with 2 and 4 Gy caused substantial cell death, which was mostly the result of apoptosis. Irradiation with 2 Gy was detrimental enough to cause loss of proliferation capability and trigger substantial cell death in vitro. The hiPS cells irradiated with 2 Gy were injected into NOG mice (NOD/Shi-scid, IL-2 Rγnull) for the analysis of tumor formation. The group of mice into which hiPS cells irradiated with 2 Gy was transplanted showed significant suppression of tumor formation in comparison with that of the group into which non-irradiated hiPS cells were transplanted. It can be presumed that this diminished rate of tumor formation was due to loss of proliferation and cell death caused by irradiation. Our findings suggest that tumor formation following cell therapy or organ transplantation induced by hiPS cells may be prevented by irradiation.

  4. The live cell irradiation and observation setup at SNAKE

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    Hable, V. [Angewandte Physik und Messtechnik LRT2, UniBw-Muenchen, 85577 Neubiberg (Germany)], E-mail: volker.hable@unibw.de; Greubel, C.; Bergmaier, A.; Reichart, P. [Angewandte Physik und Messtechnik LRT2, UniBw-Muenchen, 85577 Neubiberg (Germany); Hauptner, A.; Kruecken, R. [Physik Department E12, TU-Muenchen, 85748 Garching (Germany); Strickfaden, H.; Dietzel, S.; Cremer, T. [Department Biologie II, LMU-Muenchen, 82152 Martinsried (Germany); Drexler, G.A.; Friedl, A.A. [Strahlenbiologisches Institut, LMU-Muenchen, 80336 Muenchen (Germany); Dollinger, G. [Angewandte Physik und Messtechnik LRT2, UniBw-Muenchen, 85577 Neubiberg (Germany)

    2009-06-15

    We describe a new setup at the ion microprobe SNAKE (Superconducting Nanoscope for Applied nuclear (Kern-) physics Experiments) at the Munich 14 MV Tandem accelerator that facilitates both living cell irradiation with sub micrometer resolution and online optical imaging of the cells before and after irradiation by state of the art phase contrast and fluorescence microscopy. The cells are kept at standard cell growth conditions at 37 {sup o}C in cell culture medium. After irradiation it is possible to switch from single ion irradiation conditions to cell observation within 0.5 s. First experiments were performed targeting substructures of a cell nucleus that were tagged by TexasRed labeled nucleotides incorporated in the cellular DNA by 55 MeV single carbon ion irradiation. In addition we show first online sequences of short time kinetics of Mdc1 protein accumulation in the vicinity of double strand breaks after carbon ion irradiation.

  5. Recovery from inhibition of transcription in γ-irradiated Euglena cells

    International Nuclear Information System (INIS)

    Tsushimoto, G.; Kikuchi, T.; Ishida, M.R.

    1982-01-01

    Transcriptional activity was inhibited with low doses of γ-irradiation which did not cause the death of cells, but induced the delay of cell division in the unicellular alga Euglena. The incorporation of [ 14 C]uracil into cells was inhibited to about 50% of non-irradiated cells immediately after 3 krad irradiation. The suppressed transcriptional activity was gradually recovered after irradiation. At about 12 h post-irradiation, the rate of incorporation of [ 14 C]uracil recovered to that of non-irradiated cells. The synthesis of ribosomal RNA was inhibited immediately after 3 krad irradiation, but it recovered within 12 h after irradiation. The synthesis of cytosol ribosomal RNA precursor was more strongly inhibited than that of other cytosol ribosomal RNAs. The synthesis of cytoplasmic organelle ribosomal RNA was also inhibited and recovered after 3 krad irradiation. (Auth.)

  6. X-ray irradiation of yeast cells

    Science.gov (United States)

    Masini, Alessandra; Batani, Dimitri; Previdi, Fabio; Conti, Aldo; Pisani, Francesca; Botto, Cesare; Bortolotto, Fulvia; Torsiello, Flavia; Turcu, I. C. Edmond; Allott, Ric M.; Lisi, Nicola; Milani, Marziale; Costato, Michele; Pozzi, Achille; Koenig, Michel

    1997-10-01

    Saccharomyces Cerevisiae yeast cells were irradiated using the soft X-ray laser-plasma source at Rutherford Laboratory. The aim was to produce a selective damage of enzyme metabolic activity at the wall and membrane level (responsible for fermentation) without interfering with respiration (taking place in mitochondria) and with nuclear and DNA activity. The source was calibrated by PIN diodes and X-ray spectrometers. Teflon stripes were chosen as targets for the UV laser, emitting X-rays at about 0.9 keV, characterized by a very large decay exponent in biological matter. X-ray doses to the different cell compartments were calculated following a Lambert-Bouguet-Beer law. After irradiation, the selective damage to metabolic activity at the membrane level was measured by monitoring CO2 production with pressure silicon detectors. Preliminary results gave evidence of pressure reduction for irradiated samples and non-linear response to doses. Also metabolic oscillations were evidenced in cell suspensions and it was shown that X-ray irradiation changed the oscillation frequency.

  7. Polyamines and post-irradiation cell proliferation

    International Nuclear Information System (INIS)

    Rosiek, O.; Wronowski, T.; Lerozak, K.; Kopec, M.

    1978-01-01

    The results of three sets of experiments will be presented. Firstly polyamines and DNA content was determined in bone marrow, mesenteric lymph nodes, spleen, liver and kidney of rabbits at the 1, 5, 10 and 20th day after exposure to 600 R of X-irradiation. Polyamine concentration in bone marrow, spleen and lymph nodes was found to be markedly increased during the period of postirradiation recovery. Secondly, effect of 10 -5 M methyl glyoxalbis, guanylhydrazone (MGBG), an inhibitor of spermidine and spermine synthesis, on multiplication of X-irradiated cultures of murine lymphoblaste L5178Y-S was assessed. MGBG-induced inhibition of cell proliferation could be prevented by concurrent administration of 10 -4 M spermidine. Thirdly the influence of putrescine on bone marrow cellularity and 3 H-thymidine incorporation into bone marrow cells was investigated in X-irradiated mice. The results obtained indicate close relation of polyamines to cell proliferation processes after irradiation. (orig./AJ) [de

  8. Colon mucosal cells after high-dose fractional irradiation

    International Nuclear Information System (INIS)

    Zorc-Pleskovic, R.; Vraspir-Porenta, O.; Petrovic, D.; Zorc, M.; Pleskovic, L.

    2000-01-01

    The aim of this study was to investigate histological and stereological changes in cryptal enterocytes, mucosal lymphocytes and mast cells 10 days after irradiation. For experimental model, 24 Beagle dogs 1-2 years old were used. Twelve dogs were irradiated 20 days with 32 Gy over the whole pelvis and tail. Another 12 dogs represented a control group. For the detection of apoptosis, the TUNEL technique was used. Histological and stereological analyses were performed using a Wild sampling microscope M 1000. In the irradiated group, volume density (P < 0.01), numerical density (P < 0.05) and average volume of lymphocytes (P < 0.001) were significantly lower than in the nonirradiated group. Numerical areal density of mast cells in the irradiated group was also significantly lower (P < 0.05). Volume density (P < 0.001) and average volume of mast cells (P < 0.001) were significantly higher in the irradiated group. The results of our experiments show that irradiation causes injury and loss of lymphocytes and mast cells in the colon mucosa. Apoptosis was detected in enterocytes and lymphocytes in the irradiated group and in nonirradiated group in equal numbers (2.5 ± 0.3 vs. 2.3 ± 0.3; ns.), suggesting that 10 days after high-dose irradiation, the cell loss is not due to apoptosis. (author)

  9. Modulation of NF-KB in rescued irradiated cells

    International Nuclear Information System (INIS)

    Lam, R.K.K.; Fung, Y.K.; Han, W.; Li, L.; Chiu, S.K.; Cheng, S.H.; Yu, K.N.

    2015-01-01

    Studies by different groups on the rescue effect, where unirradiated bystander cells mitigated the damages in the irradiated cells, since its discovery by the authors' group in 2011 were first reviewed. The properties of the rescue effect were then examined using a novel experimental set-up to physically separate the rescue signals from the bystander signals. The authors' results showed that the rescue effect was mediated through activation of the nuclear factor-KB (NF-KB) response pathway in the irradiated cells, and that the NF-KB activation inhibitor BAy -1 1-7082 did not affect the activation of this response pathway in the irradiated cells induced by direct irradiation. (authors)

  10. The effects of X-irradiation on the chondrogensis of mesenchymal cells

    International Nuclear Information System (INIS)

    Ha, Jong Ryeol

    2002-01-01

    It is well known that X-irradiation affects on maturing process of differentiated chondrocytes. Nevertheless, It has been remained elusively whether X-irradiation affects the process of differentiation of mesenchymal cells which differentiate into chondrocyte, fibroblast, or muscle cells. In this study, we examined the effect of X-irradiation (with 1 to 10 Gy) on chondrogenesis using mesenchymal cells of chick limb bud. Our results show that X-irradiation dose-dependently inhibited chondrogenesis. This result suggests that immature chondroblast-like mesenchymal cells are sensitive to X-irradiation, Moreover, X-irradiation affects not only maturing process of chondrocytes, but also inhibits the chondrogenesis. Taken together, we demonstrate that the whole process of differentiation of mature chondrocytes from mesenchymal cells is affected by X-irradiation and undifferentiated cells were more affected by X-irradiation than mature cells

  11. Irradiation sensitivity of human and porcine mesenchymal stem cells

    International Nuclear Information System (INIS)

    Singh, S.

    2009-01-01

    Surgical resection, chemotherapy, radiotherapy, and combinations thereof are a plethora of possible treatment modalities of head and neck malignancies. Treatment regimens including radiotherapy however put jaws at risk of subsequent osteoradionecrosis. Besides cancer cells, irradiation impacts on all tissue-inherent cells, including mesenchymal stem cells (MSCs). Since it is the bone and bone marrow MSC, which contributes to bone regeneration through proliferation and osteogenic differentiation of its progeny, the influence of irradiation on MSC viability and the respective differentiation capacity appears to be critical. However to date, only a few reports picked MSCs role out as a pivotal topic. As a first attempt, we irradiated human bone derived MSC in vitro. With increasing doses the cells self-renewal capabilities were greatly reduced. Notably however, the mitotically stalled cells were still capable of differentiating into osteoblasts and preadipocytes. Next, the mandibles of Sus scrofa domestica were irradiated with a total dose of 18 Gy. At different time points post radiatio, MSCs were isolated from bone autopsies. In comparison between irradiated and non- irradiated samples, no significant differences regarding the proliferation and osteogenic differentiation potential of tissue specific MSC became apparent Therefore, pig mandibles were irradiated with doses of 9 and 18 Gy, and MSCs were isolated immediately afterwards. No significant differences between the untreated and bone irradiated with 9 Gy with respect of proliferation and osteogenic differentiation were observed. Cells isolated from 18 Gy irradiated specimens exhibited a greatly reduced osteogenic differentiation capacity, and during the first two weeks proliferation rates of explanted cells were greatly diminished. Thereafter, cells recovered and showed proliferation behaviour comparable to control samples. These results imply that MSCs can cope with irradiation up to relatively high doses

  12. Eimeria tenella: in vitro development in irradiated bovine kidney cells

    Energy Technology Data Exchange (ETDEWEB)

    Crane, M.St.J.; Schmatz, D.M.; Stevens, S.; Habbersett, M.C.; Murray, P.K. (Merck Sharp and Dohme Research Labs., Rahway, NJ (USA))

    1984-06-01

    The initial infection and first-generation development of Eimeria tenella was quantified using a cloned MDBK (Madin-Darby Bovine Kidney) cell line, irradiated with gamma radiation prior to infection, as the host cell. Irradiated cell cultures were found to be more susceptible to infection and had a greater capacity to support parasite development than non-irradiated cultures. It was suggested that the larger proportion of cells in the G/sub 2/ phase of the cell cycle, the larger individual cell size and the inhibition of cell division in the irradiated cultures were all factors contributing to the increased susceptibility to infection and capacity to support parasite growth and development. The application of this technique (host cell irradiation) to the cultivation of other intracellular, protozoan parasites is discussed.

  13. Eimeria tenella: in vitro development in irradiated bovine kidney cells

    International Nuclear Information System (INIS)

    Crane, M. St.J.; Schmatz, D.M.; Stevens, S.; Habbersett, M.C.; Murray, P.K.

    1984-01-01

    The initial infection and first-generation development of Eimeria tenella was quantified using a cloned MDBK (Madin-Darby Bovine Kidney) cell line, irradiated with gamma radiation prior to infection, as the host cell. Irradiated cell cultures were found to be more susceptible to infection and had a greater capacity to support parasite development than non-irradiated cultures. It was suggested that the larger proportion of cells in the G 2 phase of the cell cycle, the larger individual cell size and the inhibition of cell division in the irradiated cultures were all factors contributing to the increased susceptibility to infection and capacity to support parasite growth and development. The application of this technique (host cell irradiation) to the cultivation of other intracellular, protozoan parasites is discussed. (author)

  14. Change of cell cycle arrest of tumor cell lines after 60Co γ-irradiation

    International Nuclear Information System (INIS)

    Tang Yi; Liu Wenli; Zhou Jianfeng; Gao Qinglei; Wu Jianhong

    2003-01-01

    Objective: To observe the cell cycle arrest changes in peripheral blood mononuclear cells (PBMNCs) of normal persons and several kinds of tumor cell lines after 60 Co γ-irradiation. Methods: PBMNCs of normal persons, HL-60, K562, SiHA and 113 tumor cell lines were irradiated with 60 Co γ-rays at the absorbed doses of 6, 10,15 Gy. Cell cycles changes were checked 6, 12, 24, 48 and 60 h after the irradiation. Results: A stasis state was observed in normal person PBMNCs, 95 percents of which were in G 1 phase, and they still remained stasis after the irradiation. Except the 113 cell line manifesting G 1 phase arrest, all other tumor cell lines showed G 2 /M phase arrest after irradiation. The radiation sensitivity of HL-60 was higher than that of SiHA cell line. Conclusion: Different cell lines have different cell cycle arrest reaction to radiation and their radiation sensitivity are also different

  15. Rescue Effects: Irradiated Cells Helped by Unirradiated Bystander Cells

    Science.gov (United States)

    Lam, R. K. K.; Fung, Y. K.; Han, W.; Yu, K. N.

    2015-01-01

    The rescue effect describes the phenomenon where irradiated cells or organisms derive benefits from the feedback signals sent from the bystander unirradiated cells or organisms. An example of the benefit is the mitigation of radiation-induced DNA damages in the irradiated cells. The rescue effect can compromise the efficacy of radioimmunotherapy (RIT) (and actually all radiotherapy). In this paper, the discovery and subsequent confirmation studies on the rescue effect were reviewed. The mechanisms and the chemical messengers responsible for the rescue effect studied to date were summarized. The rescue effect between irradiated and bystander unirradiated zebrafish embryos in vivo sharing the same medium was also described. In the discussion section, the mechanism proposed for the rescue effect involving activation of the nuclear factor κB (NF-κB) pathway was scrutinized. This mechanism could explain the promotion of cellular survival and correct repair of DNA damage, dependence on cyclic adenosine monophosphate (cAMP) and modulation of intracellular reactive oxygen species (ROS) level in irradiated cells. Exploitation of the NF-κB pathway to improve the effectiveness of RIT was proposed. Finally, the possibility of using zebrafish embryos as the model to study the efficacy of RIT in treating solid tumors was also discussed. PMID:25625514

  16. Delayed cell death associated with mitotic catastrophe in γ-irradiated stem-like glioma cells

    International Nuclear Information System (INIS)

    Firat, Elke; Gaedicke, Simone; Tsurumi, Chizuko; Esser, Norbert; Weyerbrock, Astrid; Niedermann, Gabriele

    2011-01-01

    Stem-like tumor cells are regarded as highly resistant to ionizing radiation (IR). Previous studies have focused on apoptosis early after irradiation, and the apoptosis resistance observed has been attributed to reduced DNA damage or enhanced DNA repair compared to non-stem tumor cells. Here, early and late radioresponse of patient-derived stem-like glioma cells (SLGCs) and differentiated cells directly derived from them were examined for cell death mode and the influence of stem cell-specific growth factors. Primary SLGCs were propagated in serum-free medium with the stem-cell mitogens epidermal growth factor (EGF) and fibroblast growth factor-2 (FGF-2). Differentiation was induced by serum-containing medium without EGF and FGF. Radiation sensitivity was evaluated by assessing proliferation, clonogenic survival, apoptosis, and mitotic catastrophe. DNA damage-associated γH2AX as well as p53 and p21 expression were determined by Western blots. SLGCs failed to apoptose in the first 4 days after irradiation even at high single doses up to 10 Gy, but we observed substantial cell death later than 4 days postirradiation in 3 of 6 SLGC lines treated with 5 or 10 Gy. This delayed cell death was observed in 3 of the 4 SLGC lines with nonfunctional p53, was associated with mitotic catastrophe and occurred via apoptosis. The early apoptosis resistance of the SLGCs was associated with lower γH2AX compared to differentiated cells, but we found that the stem-cell culture cytokines EGF plus FGF-2 strongly reduce γH2AX levels. Nonetheless, in two p53-deficient SLGC lines examined γIR-induced apoptosis even correlated with EGF/FGF-induced proliferation and mitotic catastrophe. In a line containing CD133-positive and -negative stem-like cells, the CD133-positive cells proliferated faster and underwent more γIR-induced mitotic catastrophe. Our results suggest the importance of delayed apoptosis, associated mitotic catastrophe, and cellular proliferation for γIR-induced death of

  17. 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)

  18. Lymphocyte development in irradiated thymuses: dynamics of colonization by progenitor cells and regeneration of resident cells

    International Nuclear Information System (INIS)

    Mehr, R.; Fridkis-Hareli, M.; Abel, L.; Segel, L.; Globerson, A.

    1995-01-01

    Lymphocyte development in irradiated thymuses was analyzed using two complementary strategies: an in vitro experimental model and computer simulations. In the in vitro model, fetal thymus lobes were irradiated and the regeneration of cells that survived irradiation were examined, with the results compared to those of reconstitution of the thymus by donor bone marrow cells and their competition with the thymic resident cells. In vitro measurements of resident cell kinetics showed that cell proliferation is slowed down significantly after a relatively low (10Gy) irradiation dose. Although the number of thymocytes that survived irradiation remained low for several days post-irradiation, further colonization by donor cells was not possible, unless performed within 6 h after irradiation. These experimental results, coupled with the analysis by computer simulations, suggest that bone marrow cell engraftment in the irradiated thymus may be limited by the presence of radiation-surviving thymic resident cells and the reduced availability of seeding niches. (Author)

  19. Protection of lethally irradiated mice with allogeneic fetal liver cells: influence of irradiation dose on immunologic reconstitution

    International Nuclear Information System (INIS)

    Tulunay, O.; Good, R.A.; Yunis, E.J.

    1975-01-01

    After lethal irradiation long-lived, immunologically vigorous C3Hf mice were produced by treatment with syngeneic fetal liver cells or syngeneic newborn or adult spleen cells. Treatment of lethally irradiated mice with syngeneic or allogeneic newborn thymus cells or allogeneic newborn or adult spleen cells regularly led to fatal secondary disease or graft-versus-host reactions. Treatment of the lethally irradiated mice with fetal liver cells regularly yielded long-lived, immunologically vigorous chimeras. The introduction of the fetal liver cells into the irradiated mice appeared to be followed by development of immunological tolerance of the donor cells. The findings suggest that T-cells at an early stage of differentiation are more susceptible to tolerance induction than are T-lymphocytes at later stages of differentiation. These investigations turned up a perplexing paradox which suggests that high doses of irradiation may injure the thymic stroma, rendering it less capable of supporting certain T-cell populations in the peripheral lymphoid tissue. Alternatively, the higher and not the lower dose of irradiation may have eliminated a host cell not readily derived from fetal liver precursors which represents an important helper cell in certain cell-mediated immune functions, e.g., graft-versus-host reactions, but which is not important in others, e.g., allograft rejections. The higher dose of lethal irradiation did not permit development or maintenance of a population of spleen cells that could initiate graft-versus-host reactions but did permit the development of a population of donor cells capable of achieving vigorous allograft rejection

  20. Study of homing patterns of x-irradiated murine lymphoid cells

    International Nuclear Information System (INIS)

    Crouse, D.A.

    1974-01-01

    Effects of in vitro x-ray exposure of murine lymphoid cells on their subsequent in vivo homing patterns were studied. The homing of lymphoid cells to various tissues and organs was followed by using radio-labeled cell preparations or by following the distribution of cells with a specific immunological memory. X irradiation of 51 Cr-labeled spleen, lymph node, bone marrow, or thymus cells was found to significantly alter their subsequent in vivo distribution. Irradiated cells demonstrated an increased distribution to the liver and a significantly lower retention in the lungs. Cells going to the lymph nodes of Peyer's patches showed a significant exposure dependent decrease in homing following irradiation. Irradiated lymph node cells homed in greater numbers to the spleen and bone marrow, while irradiated cells from other sources showed a decrease or no change indistribution to the same tissues. Lymph node cell suspensions from dinitrophenyl-bovine gamma globulin (DNP-BGG) immune LBN rats were prepared, irradiated (0 and 200 R) and injected into intermediate (LBN) hosts and controls. Irradiated memory cells provided a secondary antibody response, which was delayed but not suppressed when compared to unirradiated cells. Alteration in homing of lymphocytes caused by various physical and chemical agents was a result of effects on cell membrane characteristics which controlled some aspects of the phenomenon. Radiation (100 to 200 R) may have had a similar effect or it may have resulted in the selective elimination of a population of cells. (U.S.)

  1. In vitro repopulation of haemopoietic stem cells after irradiation

    International Nuclear Information System (INIS)

    Mori, K.J.; Kumagai, Keiko; Seto, Akira; Ito, Yohei

    1981-01-01

    A culture system was designed in which proliferation of the haemopoietic stem cells was supported by adherent 'stromal' cell colonies. Application of the culture system to studies on kinetic behaviour of the haemopoietic stem cells after irradiation revealed; i) bone marrow stromal cells were radiosensitive with D 0 = 95R, when measured as the capability to proliferate and form adherent cell colonies in vitro, ii) radiosensitivity of the pluripotent stem cells (CFUs) in vitro was within the range of the in vivo sensitivity, iii) irradiated bone marrow cells under in vitro condition could repopulate at the same rate as those under in vivo condition, thereby suggesting that the function related to the support of haemopoiesis was radioresistant, iv) concentrations of both CFUs and granulocyte-macrophage precursor cells (CFUc) were higher in the irradiated cultures than those in unirradiated control culture at 3 weeks after irradiation. (author)

  2. Cell cycle delays induced by heavy ion irradiation of synchronous mammalian cells

    International Nuclear Information System (INIS)

    Scholz, M.; Kraft-Weyrather, W.; Ritter, S.; Kraft, G.

    1994-01-01

    Cell cycle delays in V79 Chinese hamster cells induced by heavy ion exposure have been investigated using flow cytometry. Synchronous cell populations in G 1 -, S- and late-S/G 2 M-phase were used. Cells were irradiated with particles from Z = 10 (neon) up to Z = 96 (uranium) in the energy range from 2.4 to 17.4 MeV/u and the LET range from 415 to 16225 keV/μm at the UNILAC at GSI, Darmstadt. For comparison, experiments with 250 kV X-rays were performed. For light particles like neon, cell cycle perturbations comparable to those after X-ray irradiation were found, and with increasing LET an increasing delay per particle traversal was observed. For the highest LET-values, extended delays in G 1 -, S- and G 2 M-phase were detected immediately after irradiation. A large fraction of the cells remained in S-phase or G 2 M-phase up to 48 h or longer after irradiation. No significant cell age dependence of cycle delays was detected for the very high LET values. In addition to cell cycle delays, two effects related to the DNA-content as determined by flow cytometry were found after irradiation with very high LET particles, which were attributed to cell fusion and to drastic morphological changes of the cells. Estimations based on the dose deposited by a single particle hit in the cell nucleus and the actual number of hits show, that the basic trend of the experimental results can be explained by the stochastic properties of particle radiation. (orig.)

  3. Cell-kinetics of the human uterine cervical carcinoma cells during radium irradiation

    International Nuclear Information System (INIS)

    Iwata, Masaharu; Sasaki, Hiroshi

    1983-01-01

    HeLa cells grown in a monolayer culture and in nude mice were exposed to graded dose rates (37, 55 or 200 rad/hour) and doses (500-2,000 rad) of radiation and analyzed in terms of their cell cycle distribution using flow-microfluorometry. In the case of the cultured HeLa cells, dose-survival curves were constructed using colony formation as the end-point. The HeLa cells, both in vitro and in vivo, accumulated in G2-M phases after both acute and chronic irradiation. The dose rate of 37 rad/hour proved to be the most effective in producing G2-M accumulation, which is the sensitive phase of the cell cycle. In comparing the G2-M accumulation to the irradiation time, 55 and 37 rad/hour proved to be similarly efficient in producing G2-M accumulation, both in vitro and in vivo. When survival of HeLa cells in vitro was studied, the radiation-induced changes in cell distribution correlated with cell survival and accounted for the change in the dose rate effect above 1,000 rads. In the case of in vivo HeLa cells, the decrease in the number of G0+G1 stage cells was demonstrated during chronic irradiation (37 and 55 rad/hour). The two low dose rates were equally efficient in producing a decrease in the number of G0+G1 cells. These data indicate that chronic irradiation induces redistribution and recruitment more effectively than acute irradiation. (author)

  4. Cell cycle progression in irradiated endothelial cells cultured from bovine aorta

    International Nuclear Information System (INIS)

    Rubin, D.B.; Drab, E.A.; Ward, W.F.; Bauer, K.D.

    1988-01-01

    Logarithmically growing endothelial cells from bovine aortas were exposed to single doses of 0-10 Gy of 60Co gamma rays, and cell cycle phase distribution and progression were examined by flow cytometry and autoradiography. In some experiments, cells were synchronized in the cell cycle with hydroxyurea (1 mM). Cell number in sham-irradiated control cultures doubled in approximately 24 h. Estimated cycle stage times for control cells were 14.4 h for G1 phase, 7.2 h for S phase, and 2.4 h for G2 + M phase. Irradiated cells demonstrated a reduced distribution at the G1/S phase border at 4 h, and an increased distribution in G2 + M phase at 24 h postirradiation. Autoradiographs of irradiated cells after continuous [3H]thymidine labeling indicated a block in G1 phase or at the G1/S-phase border. The duration of the block was dose dependent (2-3 min/cGy). Progression of the endothelial cells through S phase after removal of the hydroxyurea block also was retarded by irradiation, as demonstrated by increased distribution in early S phase and decreased distribution in late S phase. These results indicate that progression of asynchronous cultured bovine aortic endothelial cells through the DNA synthetic cycle is susceptible to radiation inhibition at specific sites in the cycle, resulting in redistribution and partial synchronization of the population. Thus aortic endothelial cells, diploid cells from a normal tissue, resemble many immortal cell types that have been examined in this regard in vitro

  5. Untargeted viral mutagenesis is not found in X-irradiated monkey cells

    International Nuclear Information System (INIS)

    Lytle, C.D.; Carney, P.G.; Lee, W.; Bushar, H.F.

    1988-01-01

    The existence of untargeted viral mutagenesis in X-irradiated cells was investigated in a mammalian virus/cell system, where a low level of such viral mutagenesis can be demonstrated in UV-irradiated cells. In the positive control experiment UV-elicited mutagenesis was shown with cell exposures of 5, 10 and 15 J/m 2 and a delay of 24 h between cell irradiation and infection with unirradiated herpes simplex virus. Although X-ray doses of 1, 3 and 10 Gy elicit enhanced reactivation of UV-irradiated virus, no untargeted mutagenesis for any X-ray dose at post-irradiation infection times of 0, 24 or 72 h was observed in this study. Thus untargeted mutagenesis of herpes simplex virus was not demonstrated in X-irradiated monkey cells, under conditions where X-ray-enhanced reactivation occurs and where untargeted mutagenesis in UV-irradiated cells occurs. (author)

  6. Influence of Ouabain on cell inactivation by irradiation

    International Nuclear Information System (INIS)

    Verheye-Dua, F.A.; Boehm, L.

    1996-01-01

    Background: It has been suggested that irradiation affects the function of the Na + -K + -ATPase. Here we examine the influence of the inhibitor ouabain on the cytotoxicity or irradiation. Material and Methods: Cell colony assay, cell survival, 86 Rb-uptake, flow cytometry. Results: In V79, HeLa and A549 cell ouabain alone causes a significant growth reduction at medium concentrations of 10 -4 M, 10 -6 M and 10 -7 M, respectively. When cells were exposed to the drug for 1 h and subsequently irradiated, the SF2 values decreased from 0.55 to 0.41, from 0.42 to 0.18 and from 0.57 to 0.35 in V79, HeLa and A549 cells, respectively. These effects were manifest at drug concentrations of 10 -3 M, 10 -6 M and 10 -7 M respectively, where Na + -K + -ATPase activity as mesured by 86 Rb-uptake was reduced to 40 to 60% of the control value. Addition of the drug after irradiation and when the G2/M cell cycle block was firmly established, markedly delayed the recovery of cells for well over 6 h and G1 levels remained at 50% of the control values. Conclusion: It is concluded that ouabain is strongly dose modifying in the human cell lines HeLa and A549 at concentrations which correlate with the inhibition of the Na + -K + -ATPase. Ouabain also inhibits the recovery of cells blocked in the cell cycle by irradiation. (orig.) [de

  7. Effective suppression of bystander effects by DMSO treatment of irradiated CHO cells

    International Nuclear Information System (INIS)

    Kashino, Genro; Prise, K.M.; Suzuki, Keiji

    2007-01-01

    Evidence is accumulating that irradiated cells produce some signals which interact with non-exposed cells in the same population via a bystander effect. Here, we examined whether dimethyl sulfoxide (DMSO) is effective in suppressing radiation induced bystander effects in Chinese hamster ovary (CHO) and repair deficient xrs5 cells. When 1 Gy-irradiated CHO cells were treated with 0.5% DMSO for 1 hr before irradiation, the induction of micronuclei in irradiated cells was suppressed to 80% of that in non-treated irradiated cells. The suppressive effect of DMSO on the formation of bystander signals was examined and the results demonstrated that 0.5% DMSO treatment of irradiated cells completely suppressed the induction of micronuclei by the bystander effect in non-irradiated cells. It is suggested that irradiated cells ceased signal formation for bystander effects by the action of DMSO. To determine the involvement of reactive oxygen species on the formation of bystander signals, we examined oxidative stress levels using the 2',7'-dichlorofluorescein (DCFH) staining method in irradiated populations. The results showed that the treatment of irradiated cells with 0.5% DMSO did not suppress oxidative stress levels. These results suggest that the prevention of oxidative stress is independent of the suppressive effect of DMSO on the formation of the bystander signal in irradiated cells. It is suggested that increased reactive oxygen species (ROS) in irradiated cells is not a substantial trigger of a bystander signal. (author)

  8. Tumor necrosis factor alpha production in irradiated cells in vitro

    International Nuclear Information System (INIS)

    Koeteles, G.J.; Bognar, G.; Kubasova, T.

    1994-01-01

    Normal and tumor cell lines were used to investigate tumor necrosis factor (TNFα) production and its radiation sensitivity. The cells were irradiated with gamma rays using different doses from 0.25 Gy up to 5 Gy. The number of plated cells, changes of proliferation and TNFα production were determined during the following four post-irradiation days. For TNFα quantity measurement immuno-radiometric assay (IRMA) and enzyme amplified sensitivity assay (EASIA) was used. The results suggest that though gamma irradiation decreased cell proliferation in a dose dependent manner, the quantity produced in the post-irradiation period increased considerably in each irradiated sample. (N.T.) 3 refs.; 2 figs.; 1 tab

  9. Cell cycle delays in synchronized cell populations following irradiation with heavy ions

    International Nuclear Information System (INIS)

    Scholz, M.

    1992-11-01

    Mammalian cells subjected to irradiation with heavy ions were investigated for cell cycle delays. The ions used for this purpose included Ne ions in the LET range of 400 keV/μm just as well as uranium ions of 16225 keV/μm. The qualitative changes in cell cycle progression seen after irradiation with Ne ions (400 keV/μm) were similar to those observed in connection with X-rays. Following irradiation with extremely heavy ions (lead, uranium) the majority of cells were even at 45 hours still found to be in the S phase or G 2 M phase of the first cycle. The delay cross section 'σ-delay' was introduced as a quantity that would permit quantitative comparisons to be carried out between the changes in cell progression and other effects of radiation. In order to evaluate the influence of the number of hits on the radiation effect observed, the size of the cell nucleus was precisely determined with reference to the cycle phase and local cell density. A model to simulate those delay effects was designed in such a way that account is taken of this probability of hit and that the results can be extrapolated from the delay effects after X-irradiation. On the basis of the various probabilities of hit for cells at different cycle stages a model was developed to ascertain the intensified effect following fractionated irradiation with heavy ions. (orig./MG) [de

  10. Beneficial Effect of the Nutritional Support in Children Who Underwent Hematopoietic Stem Cell Transplant.

    Science.gov (United States)

    Koç, Nevra; Gündüz, Mehmet; Tavil, Betül; Azik, M Fatih; Coşkun, Zeynep; Yardımcı, Hülya; Uçkan, Duygu; Tunç, Bahattin

    2017-08-01

    The aim of this study was to evaluate nutritional status in children who underwent hematopoietic stem cell transplant compared with a healthy control group. A secondary aim was to utilize mid-upper arm circumference as a measure of nutritional status in these groups of children. Our study group included 40 children (18 girls, 22 boys) with mean age of 9.2 ± 4.6 years (range, 2-17 y) who underwent hematopoietic stem cell transplant. Our control group consisted of 20 healthy children (9 girls, 11 boys). The children were evaluated at admission to the hospital and followed regularly 3, 6, 9, and 12 months after discharge from the hospital. In the study group, 27 of 40 patients (67.5%) received nutritional support during hematopoietic stem cell transplant, with 15 patients (56%) receiving enteral nutrition, 6 (22%) receiving total parenteral nutrition, and 6 (22%) receiving enteral and total parenteral nutrition. Chronic malnutrition rate in the study group was 47.5% on admission to the hospital, with the control group having a rate of 20%. One year after transplant, the rate decreased to 20% in the study group and 5% in the control group. The mid-upper arm circumference was lower in children in the study group versus the control group at the beginning of the study (P groups at follow-up examinations (P > .05). During follow-up, all anthropometric measurements increased significantly in both groups. Monitoring nutritional status and initiating appropriate nutritional support improved the success of hematopoietic stem cell transplant and provided a more comfortable process during the transplant period. Furthermore, mid-upper arm circumference is a more sensitive, useful, and safer parameter that can be used to measure nutritional status of children who undergo hematopoietic stem cell transplant.

  11. Hematopoietic stem cell migration and proliferation after Partial body irradiation

    International Nuclear Information System (INIS)

    Murata, Takashi; Utsumi, Makoto; Hotta, Tomomitsu; Yamada, Hideo

    1983-01-01

    Stem cell migration in hematopoietic recovery after partial body irradiation was investigated with special emphasis on the comparative roles of the bone marrow and the spleen. The number of CFU-S in circulation declined rapidly and reached zero within a day after irradiation, thereafter it increased gradually. This finding suggests the presence of two different phases of stem cell migration. One is a rapid migrating phase in which stem cells are released rapidly within a day after irradiation, and the other is a slow migrating phase. The result of split doses of local body irradiation experiments implicated a role for the spleen distinct from that of the bone marrow in the preferential distribution of stem cells early after irradiation. The cell kinetic study showed that the proliferation of CFU-S occurred actively in irradiated bone marrow and the spleens as compared to that in unirradiated control. But on Day 7 and on Day 10 after irradiation, the proliferation of CFU-S in shielded bone marrow did not occur as actively as those in irradiated areas. The results of our present studies suggest that the spleen is not only the storage pools of migrating stem cells but also the main site of active proliferation of CFU-S in the early period of hematopoietic regeneration. (author)

  12. Osteogenic Matrix Cell Sheets Facilitate Osteogenesis in Irradiated Rat Bone

    Directory of Open Access Journals (Sweden)

    Yoshinobu Uchihara

    2015-01-01

    Full Text Available Reconstruction of large bone defects after resection of malignant musculoskeletal tumors is a significant challenge in orthopedic surgery. Extracorporeal autogenous irradiated bone grafting is a treatment option for bone reconstruction. However, nonunion often occurs because the osteogenic capacity is lost by irradiation. In the present study, we established an autogenous irradiated bone graft model in the rat femur to assess whether osteogenic matrix cell sheets improve osteogenesis of the irradiated bone. Osteogenic matrix cell sheets were prepared from bone marrow-derived stromal cells and co-transplanted with irradiated bone. X-ray images at 4 weeks after transplantation showed bridging callus formation around the irradiated bone. Micro-computed tomography images at 12 weeks postoperatively showed abundant callus formation in the whole circumference of the irradiated bone. Histology showed bone union between the irradiated bone and host femur. Mechanical testing showed that the failure force at the irradiated bone site was significantly higher than in the control group. Our study indicates that osteogenic matrix cell sheet transplantation might be a powerful method to facilitate osteogenesis in irradiated bones, which may become a treatment option for reconstruction of bone defects after resection of malignant musculoskeletal tumors.

  13. Investigation of the response of low-dose irradiated cells. Pt. 2. Radio-adaptive response of human embryonic cells is related to cell-to-cell communication

    International Nuclear Information System (INIS)

    Ishii, Keiichiro; Watanabe, Masami.

    1994-01-01

    To clarify the radio-adaptive response of normal cells to low-dose radiation, we irradiated human embryonic cells and HeLa cells with low-dose X-ray and examined the changes in sensitivity to subsequent high-dose X-irradiation. The results obtained were as follows; (1) When HE cells were irradiated by a high-dose of 200 cGy, the growth ratio of the living cells five days after the irradiation decreased to 37% of that of the cells which received no X-irradiation. When the cells received a preliminary irradiation of 10 to 20 cGy four hours before the irradiation of 200 cGy, the relative growth ratios increased significantly to 45-53%. (2) This preliminary irradiation effect was not observed in HeLa cells, being cancer cells. (3) When the HE cells suspended in a Ca 2+ iron-free medium or TPA added medium while receiving the preliminary irradiation of 13 cGy, the effect of the preliminary irradiation in increasing the relative growth ratio of living cells was not observed. (4) This indicates that normal cells shows an adaptive response to low-dose radiation and become more radioresistant. This phenomenon is considered to involve cell-to-cell communication maintained in normal cells and intracellular signal transduction in which Ca 2+ ion plays a role. (author)

  14. Influence of low dose irradiation on differentiation, maturation and T-cell activation of human dendritic cells

    Energy Technology Data Exchange (ETDEWEB)

    Jahns, Jutta [Department of Radiotherapy and Radiation Oncology, University of Leipzig, Stephanstrasse 21, 04103 Leipzig (Germany); Anderegg, Ulf; Saalbach, Anja [Department for Dermatology, Venerology and Allergology, University of Leipzig, Johannisallee 30, 04103 Leipzig (Germany); Rosin, Britt; Patties, Ina; Glasow, Annegret [Department of Radiotherapy and Radiation Oncology, University of Leipzig, Stephanstrasse 21, 04103 Leipzig (Germany); Kamprad, Manja [Institute for Clinical Immunology and Transfusion Medicine, University of Leipzig, Johannisallee 30, 04103 Leipzig (Germany); Scholz, Markus [Institute for Medical Informatics, Statistics and Epidemiology, University of Leipzig, Haertelstr. 16-18, 04103 Leipzig (Germany); Hildebrandt, Guido, E-mail: Guido.Hildebrandt@uni-rostock.de [Department of Radiotherapy and Radiation Oncology, University of Rostock, Suedring 75, 18059 Rostock (Germany); Department of Radiotherapy and Radiation Oncology, University of Leipzig, Stephanstrasse 21, 04103 Leipzig (Germany)

    2011-05-10

    Ionizing irradiation could act directly on immune cells and may induce bystander effects mediated by soluble factors that are released by the irradiated cells. This is the first study analyzing both the direct effect of low dose ionizing radiation (LDIR) on the maturation and cytokine release of human dendritic cells (DCs) and the functional consequences for co-cultured T-cells. We showed that irradiation of DC-precursors in vitro does not influence surface marker expression or cytokine profile of immature DCs nor of mature DCs after LPS treatment. There was no difference of single dose irradiation versus fractionated irradiation protocols on the behavior of the mature DCs. Further, the low dose irradiation did not change the capacity of the DCs to stimulate T-cell proliferation. But the irradiation of the co-culture of DCs and T-cells revealed significantly lower proliferation of T-cells with higher doses. Summarizing the data from approx. 50 DC preparations there is no significant effect of low dose ionizing irradiation on the cytokine profile, surface marker expression and maturation of DCs in vitro although functional consequences cannot be excluded.

  15. Irradiation of single cells with individual high-LET particles

    International Nuclear Information System (INIS)

    Nelson, J.M.; Braby, L.A.

    1993-01-01

    The dose-limiting normal tissue of concern when irradiating head and neck lesions is often the vascular endothelium within the treatment field. Consequently, the response of capillary endothelial cells exposed to moderate doses of high LET particles is essential for establishing exposure limits for neutron-capture therapy. In an effort to characterize the high-LET radiation biology of cultured endothelial cells, the authors are attempting to measure cellular response to single particles. The single-particle irradiation apparatus, described below, allows them to expose individual cells to known numbers of high-LET particles and follow these cells for extended periods, in order to assess the impact of individual particles on cell growth kinetics. Preliminary cell irradiation experiments have revealed complications related to the smooth and efficient operation of the equipment; these are being resolved. Therefore, the following paragraphs deal primarily with the manner by which high LET particles deposit energy, the requirements for single-cell irradiation, construction and assembly of such apparatus, and testing of experimental procedures, rather than with the radiation biology of endothelial cells

  16. Estrogen enhanced cell-cell signalling in breast cancer cells exposed to targeted irradiation

    International Nuclear Information System (INIS)

    Shao, Chunlin; Folkard, Melvyn; Held, Kathryn D; Prise, Kevin M

    2008-01-01

    Radiation-induced bystander responses, where cells respond to their neighbours being irradiated are being extensively studied. Although evidence shows that bystander responses can be induced in many types of cells, it is not known whether there is a radiation-induced bystander effect in breast cancer cells, where the radiosensitivity may be dependent on the role of the cellular estrogen receptor (ER). This study investigated radiation-induced bystander responses in estrogen receptor-positive MCF-7 and estrogen receptor-negative MDA-MB-231 breast cancer cells. The influence of estrogen and anti-estrogen treatments on the bystander response was determined by individually irradiating a fraction of cells within the population with a precise number of helium-3 using a charged particle microbeam. Damage was scored as chromosomal damage measured as micronucleus formation. A bystander response measured as increased yield of micronucleated cells was triggered in both MCF-7 and MDA-MB-231 cells. The contribution of the bystander response to total cell damage in MCF-7 cells was higher than that in MDA-MB-231 cells although the radiosensitivity of MDA-MB-231 was higher than MCF-7. Treatment of cells with 17β-estradiol (E2) increased the radiosensitivity and the bystander response in MCF-7 cells, and the effect was diminished by anti-estrogen tamoxifen (TAM). E2 also increased the level of intracellular reactive oxygen species (ROS) in MCF-7 cells in the absence of radiation. In contrast, E2 and TAM had no influence on the bystander response and ROS levels in MDA-MB-231 cells. Moreover, the treatment of MCF-7 cells with antioxidants eliminated both the E2-induced ROS increase and E2-enhanced bystander response triggered by the microbeam irradiation, which indicates that ROS are involved in the E2-enhanced bystander micronuclei formation after microbeam irradiation. The observation of bystander responses in breast tumour cells may offer new potential targets for radiation

  17. Response of thyroid follicular cells to gamma irradiation compared to proton irradiation. I. Initial characterization of DNA damage, micronucleus formation, apoptosis, cell survival, and cell cycle phase redistribution

    Science.gov (United States)

    Green, L. M.; Murray, D. K.; Bant, A. M.; Kazarians, G.; Moyers, M. F.; Nelson, G. A.; Tran, D. T.

    2001-01-01

    The RBE of protons has been assumed to be equivalent to that of photons. The objective of this study was to determine whether radiation-induced DNA and chromosome damage, apoptosis, cell killing and cell cycling in organized epithelial cells was influenced by radiation quality. Thyroid-stimulating hormone-dependent Fischer rat thyroid cells, established as follicles, were exposed to gamma rays or proton beams delivered acutely over a range of physical doses. Gamma-irradiated cells were able to repair DNA damage relatively rapidly so that by 1 h postirradiation they had approximately 20% fewer exposed 3' ends than their counterparts that had been irradiated with proton beams. The persistence of free ends of DNA in the samples irradiated with the proton beam implies that either more initial breaks or a quantitatively different type of damage had occurred. These results were further supported by an increased frequency of chromosomal damage as measured by the presence of micronuclei. Proton-beam irradiation induced micronuclei at a rate of 2.4% per gray, which at 12 Gy translated to 40% more micronuclei than in comparable gamma-irradiated cultures. The higher rate of micronucleus formation and the presence of larger micronuclei in proton-irradiated cells was further evidence that a qualitatively more severe class of damage had been induced than was induced by gamma rays. Differences in the type of damage produced were detected in the apoptosis assay, wherein a significant lag in the induction of apoptosis occurred after gamma irradiation that did not occur with protons. The more immediate expression of apoptotic cells in the cultures irradiated with the proton beam suggests that the damage inflicted was more severe. Alternatively, the cell cycle checkpoint mechanisms required for recovery from such damage might not have been invoked. Differences based on radiation quality were also evident in the alpha components of cell survival curves (0.05 Gy(-1) for gamma rays, 0

  18. Effects of irradiated biodegradable polymer in endothelial cell monolayer formation

    Energy Technology Data Exchange (ETDEWEB)

    Arbeitman, Claudia R.; Grosso, Mariela F. del [CONICET – Consejo Nacional de Investigaciones Científicas y Técnicas (Argentina); Gerencia de Investigación y Aplicaciones, TANDAR-CNEA (Argentina); Behar, Moni [Instituto de Física, UFRGS, Porto Alegre, RS (Brazil); García Bermúdez, Gerardo, E-mail: ggb@tandar.cnea.gov.ar [CONICET – Consejo Nacional de Investigaciones Científicas y Técnicas (Argentina); Gerencia de Investigación y Aplicaciones, TANDAR-CNEA (Argentina); Escuela de Ciencia y Tecnología, UNSAM (Argentina)

    2013-11-01

    In this work we study cell adhesion, proliferation and cell morphology of endothelial cell cultured on poly-L-lactide acid (PLLA) modified by heavy ion irradiation. Thin films of PLLA samples were irradiated with sulfur (S) at energies of 75 MeV and gold (Au) at 18 MeV ion-beams. Ion beams were provided by the Tandar (Buenos Aires, Argentina) and Tandetron (Porto Alegre, Brazil) accelerators, respectively. The growth of a monolayer of bovine aortic endothelial cells (BAEC) onto unirradiated and irradiated surfaces has been studied by in vitro techniques in static culture. Cell viability and proliferation increased on modified substrates. But the results on unirradiated samples, indicate cell death (necrosis/apoptosis) with the consequent decrease in proliferation. We analyzed the correlation between irradiation parameters and cell metabolism and morphology.

  19. Effects of irradiated biodegradable polymer in endothelial cell monolayer formation

    International Nuclear Information System (INIS)

    Arbeitman, Claudia R.; Grosso, Mariela F. del; Behar, Moni; García Bermúdez, Gerardo

    2013-01-01

    In this work we study cell adhesion, proliferation and cell morphology of endothelial cell cultured on poly-L-lactide acid (PLLA) modified by heavy ion irradiation. Thin films of PLLA samples were irradiated with sulfur (S) at energies of 75 MeV and gold (Au) at 18 MeV ion-beams. Ion beams were provided by the Tandar (Buenos Aires, Argentina) and Tandetron (Porto Alegre, Brazil) accelerators, respectively. The growth of a monolayer of bovine aortic endothelial cells (BAEC) onto unirradiated and irradiated surfaces has been studied by in vitro techniques in static culture. Cell viability and proliferation increased on modified substrates. But the results on unirradiated samples, indicate cell death (necrosis/apoptosis) with the consequent decrease in proliferation. We analyzed the correlation between irradiation parameters and cell metabolism and morphology

  20. Splenic irradiation for hairy cell leukaemia

    Energy Technology Data Exchange (ETDEWEB)

    Al-Moundhri, A.; Graham, P.H. [St George Hospital, Kogarah, NSW, (Australia). Department of Radiation Oncology

    1997-11-01

    Splenic irradiation in the management of hairy cell leukaemia is previously unreported. A case is presented here to illustrate that splenic irradiation may be a useful addition to systemic therapies. It achieved local splenic and blood picture response and remission similar to splenectomy without any significant toxicity. (authors). 7 refs., 2 figs.

  1. PHOTODYNAMIC THERAPY FOR HEAD AND NECK BASAL CELL SKIN CANCER WITH ADDITIONAL INTERSTITIAL LASER IRRADIATION

    Directory of Open Access Journals (Sweden)

    V. N. Kapinus

    2017-01-01

    Full Text Available The article is devoted to the development and evaluation of the effi ciency of photodynamic therapy (PDT with photosensitizer photolon with additional interstitial laser irradiation in patients with head and  neck basal cell skin cancer (BCSC. Treatment was performed in 55  patients. On the fi rst stage, all patients underwent photodynamic  therapy with interstitial irradiation using fl exible optical fi bers with  cylindrical diffuser, on the second stage PDT with distant delivery of  laser at a dose of 50-300 J/cm2 was carried out. During the follow- up period of 6 months to 4 years in 13 (23.6% of the 55 patients a  recurrence of the disease was diagnosed. A higher rate of recurrence was in the group of patients who underwent PDT for recurrent  neoplasms compared with patients with primary disease (37.5% and 4.3%, respectively, in patients with endophytic growth of the tumor compared to patients with exophytic component (30.0% and 16.0%,respectively and in patients with large tumors (up to 2.0 cm – 14.3%, from 2.0 to 5.0 cm – 16.7% and more than 5.0 cm – 54.4%.

  2. Functional State of Haemopoietic Stem Cells in the Irradiated Mouse

    Energy Technology Data Exchange (ETDEWEB)

    Silini, G.; Pozzi, Laura V. [Laboratorio di Radiobiologica Animale, Centro Studi Nucleari, Casaccia, Rome (Italy)

    1968-08-15

    The repopulation kinetics of bone marrow in irradiated (C3H x C57BL) F{sub 1} hybrid mice were followed at different time intervals after a single whole-body dose of 150 rad X -rays. The changes in the number of total nucleated cells and of colony-forming cells were estimated and expressed as number of cells per femur shaft of fixed length. For the evaluation of the progenitor cell compartment an exogenous test of transplantation into heavily irradiated hosts followed by spleen colony counts was employed. In an attempt to distinguish between cycling and dormant cells in the progenitor pool, vinblastine was also administered under various schedules of treatment with respect to time and dosage to follow the changes induced by this drug in the irradiated recovering marrow. The depopulation of total bone-m arrow cells caused by vinblastine proceeded at a comparable rate in both the irradiated and the normal mouse. On the other hand, depopulation of the colony-formers is faster in animals irradiated 1 -2 days previously as compared with normal animals or mice irradiated 1 week or 2 weeks earlier. The data were interpreted to show that in the marrow of a newly-irradiated animal more cells are in a fast cycle than in a normal or a recovering animal. Data are finally presented and discussed concerning the use of vinblastine for studies of stem cell kinetics in haemopoietic tissues. (author)

  3. Ultraviolet B irradiation induces expansion of intraepithelial tumor cells in a tissue model of early cancer progression.

    Science.gov (United States)

    Mudgil, Adarsh V; Segal, Nadav; Andriani, Frank; Wang, Youai; Fusenig, Norbert E; Garlick, Jonathan A

    2003-07-01

    Ultraviolet B irradiation is thought to enable skin cancer progression as clones of genetically damaged keratinocytes escape apoptosis and expand at the expense of adjacent normal cells. Mechanisms through which potentially malignant cells in human skin undergo clonal expansion, however, are not well understood. The goal of this study was to characterize the role of ultraviolet B irradiation on the intraepithelial expansion of early stage human tumor cells in organotypic skin cultures. To accomplish this, we have studied the effect of ultraviolet B irradiation on organotypic cultures that were fabricated by mixing normal human keratinocytes with beta-galactosidase-marked, intraepithelial tumor cells (HaCaT-ras, clone II-4), which bear mutations in both p53 alleles and harbor an activated H-ras oncogene. We found that when organotypic mixtures were exposed to an ultraviolet B dose of 50 mJ per cm2, intraepithelial tumor cells underwent a significant degree of proliferative expansion compared to nonirradiated cultures. To understand this response, organotypic cultures of nor-mal keratinocytes were exposed to ultraviolet B and showed a dose-dependent increase in numbers of sunburn cells and TUNEL-positive cells although their proliferation was suppressed. In contrast, neither the apoptotic nor the proliferative response of II-4 cells was altered by ultraviolet B in organotypic cultures. The differential response of these cell types suggested that II-4 cells were resistant to ultraviolet-B-induced alterations, which allowed these intraepithelial tumor cells to gain a selective growth and survival advantage relative to neighboring normal cells. These findings demonstrate that ultraviolet B exposure can induce the intraepithelial expansion of apoptosis-resistant, p53-mutant, and ras-activated keratinocytes, suggesting that this agent can act to promote the early stages of epithelial carcinogenesis.

  4. Bone cell viability after irradiation

    International Nuclear Information System (INIS)

    Jacobsson, M.; Kaelebo, P.; Tjellstroem, A.; Turesson, I.; Goeteborg Univ.; Goeteborg Univ.; Goeteborg Univ.

    1987-01-01

    Adult rabbits were irradiated to one proximal tibial metaphysis while the contralateral tibia served as a control. Each animal was thus its own control. Single doses of 15, 25 and 40 Gy 60 Co were used. The follow-up time was 11 to 22 weeks after irradiation. A histochemical method, recording diaphorase (NADH 2 and NADPH 2 ) activity in osteocytes, was employed. This method is regarded as superior to conventional histology. No evidence of osteocyte death was found even after 22 weeks following 40 Gy irradiation. This is interpreted as an indication that the osteocytes, which are end stage cells, are relatively radioresistant. (orig.)

  5. Recovery of rat lens epithelial cells after total or partial x-irradiation

    International Nuclear Information System (INIS)

    Miller, R.C.; Riley, E.F.

    1987-01-01

    Irradiation of whole lenses interferes with the normal mitogenic response of lens cells to stimulation by mechanical wounding. Radiation exposure causes a delay and partial suppression of cells entering the S phase of the cell cycle. When cells are irradiated 1 day before wounding, DNA synthesis begins 20 hr after wounding and peaks 10 hr later. The return to a normal wound response is gradual when the time interval between irradiation and wounding is lengthened. By 28 days, essentially complete recovery of the wound response occurs. Mitosis shows a similar pattern of recovery. When half of the lens is irradiated 1 day before wounding, delay and suppression of the wound response in the irradiated half of the lens epithelium is observed. However, if 4 days elapse between irradiation and mechanical wounding, complete recovery of cells responding to the mitogenic stimulus occurs. Cells of the shielded half of the lens appear to compensate for the reduced number of irradiated cells entering S phase so that peak labelling of shielded cells is 70% compared with 50% for control lens cells. An evaluation of mitotic figures confirms faster recovery of the entire lens when only half the lens is irradiated. Complete recovery of the cellular response of partially irradiated lenses occurs in 4 days in contrast to almost 28 days for wholly irradiated lenses. (author)

  6. Effects of irradiation on cytokine production in glioma cell lines

    Energy Technology Data Exchange (ETDEWEB)

    Yamanaka, Ryuya; Tanaka, Ryuichi; Yoshida, Seiichi [Niigata Univ. (Japan). Brain Research Inst.

    1993-11-01

    The effects of irradiation on cytokine production in glioma cell lines, NP1, NP2 and NP3, were studied. Culture supernatants were collected after 6, 24, 48 or 72 hours and the concentrations of interleukin (IL)-6 and IL-8 measured by enzyme-linked immunosorbent assay. Spontaneous and IL-1[beta]-stimulated productions were analyzed. Some cells were given a single dose of Lineac irradiation (10 or 20 Gy). Production of IL-6 (with or without IL-1[beta] stimulation) increased gradually to a maximum after 72 hours, more in the 20 Gy-irradiated cells than 10 Gy cells (p<0.01). Production of IL-8 increased gradually to a maximum after 48 or 72 hours. Spontaneous production of IL-8 increased more in 20 Gy-irradiated cells than 10 Gy cells after 6 and 24 hours (p<0.01), but increased more in 10 Gy cells than 20 Gy cells after 48 and 72 hours (p<0.01). The production of IL-8 stimulated by IL-1[beta] increased more in 10 Gy cells than 20 Gy cells 24 hours later (p<0.01). IL-6 and IL-8 production differed in the response to irradiation. Our data suggest that bidirectional communication between the immune system and glioma cells changes after radiotherapy. (author).

  7. Cellular therapy without cells: extracellular vesicles promote activation of stem cells after irradiation

    International Nuclear Information System (INIS)

    Lange, C.

    2016-01-01

    Mesenchymal stromal cells from the bone marrow (MSC) have been shown to be effective in several cell therapeutic treatments. However, MSC accumulate in lungs after i.v. injection. How do MSC transfer their potential to organs with therapeutic need? We show that released extracellular vesicles (EV) might be playing an active role in this transfer. EV were isolated from MSC supernatant and characterized with flow cytometry, proteomics and next generation sequencing. Our data showed the transfer of RNAs, clustering into several protective gene groups. Besides, we repeatedly detected genomic DNA on vesicles. Using a plant - derived detector gene we showed horizontal DNA transfer via EV. Furthermore, we showed that EV were able to salvage stem/progenitor cells in vitro from radiation suppression. Three selected proteins from proteomics data were examined for stem cell protection after irradiation. EV derived from down-regulated producer MSC showed a substantial loss of protection in irradiated stem cells supporting their relevance for stem cell protection. Finally, we showed that EV after i.v. injection into lethally irradiated animals colocalize within 2-4 hours with hematopoietic stem cells in the bone marrow giving hint to direct protection of stem cells by EV. In conclusion, EV derived from bone marrow MSC were able to transfer several cargo compounds leading potentially to change of the genetic properties. Importantly, EV protect irradiated hematopoietic stem cells, stimulate their recovery and proliferation and rescue lethally irradiated animals long-term. Thus, EV might be an alternative for future cell therapeutic treatment particularly in radiation-based events. (author)

  8. Killing effect of peripheral blood mononuclear cells irradiated by γ ray on human gastric cancer MKN-28 cell

    International Nuclear Information System (INIS)

    Wu Daocheng; Zhang Xianqing; Mu Shijie; Liu Zhongxiang; Xia Aijun; Huang Xiaofeng; An Qunxing

    2007-01-01

    Objective: To observe the killing effect of peripheral blood mononuclear cells (PBMCs) irradiated by γ ray on cultured human gastric cancer cell line MKN-28. Methods: The experiment were divided into MKN-28 tumor cell control group, PBMCs groups and MKN-28 cells with irradiated or non-irradiated PBMCs co-culture groups. Radidation dosage were from 0.5 to 3 Gy, acridine orange/ethidium bromide (AO/EB) staining were used to observe the kill effect of PBMCs on tumor cells in different period. Results: After culture for 144h, the dead cells of several dosage irradiated PBMCs are much more than those of non-irradiated PBMCs group. At 240 hours of culture, the alive PBMCs deareses in number in both irradiated and non-irradiared groups, but decreases in radiated groups are more obvious. After culture for 72 h in the co-cultured groups, the difference is not evident among all radiation dosage groups. After 96-240 h of co-culture, the killing effect of 0.5-2Gy irradiated PBMCs on tumor cells is very strong, especially in 1Gy group, but the killing effect of PBMCs irradiated by 2.5-3Gy on tumor cells were weaker than that of 0.5-2Gy irradiated groups. At 240 hours co-cultured groups irradiated by 2.5-3Gy, tumor cells still survive and proliferate. Conclusion: Gamma ray irradiation have killing effect to some PBMCs. The cytocidal effect of PBMCs irradiated by 0.5-2Gy on tumor cells were increased. Chemotaxis and cytocidal effect of tumor cells to postirradiated PBMCs were also found. The killing effect of PBMCs irradiated by 2.5 and 3 Gy on tumor cells were restrained. (authors)

  9. Low Doses of Gamma-Irradiation Induce an Early Bystander Effect in Zebrafish Cells Which Is Sufficient to Radioprotect Cells

    Science.gov (United States)

    Pereira, Sandrine; Malard, Véronique; Ravanat, Jean-Luc; Davin, Anne-Hélène; Armengaud, Jean; Foray, Nicolas; Adam-Guillermin, Christelle

    2014-01-01

    The term “bystander effect” is used to describe an effect in which cells that have not been exposed to radiation are affected by irradiated cells though various intracellular signaling mechanisms. In this study we analyzed the kinetics and mechanisms of bystander effect and radioadaptation in embryonic zebrafish cells (ZF4) exposed to chronic low dose of gamma rays. ZF4 cells were irradiated for 4 hours with total doses of gamma irradiation ranging from 0.01–0.1 Gy. In two experimental conditions, the transfer of irradiated cells or culture medium from irradiated cells results in the occurrence of DNA double strand breaks in non-irradiated cells (assessed by the number of γ-H2AX foci) that are repaired at 24 hours post-irradiation whatever the dose. At low total irradiation doses the bystander effect observed does not affect DNA repair mechanisms in targeted and bystander cells. An increase in global methylation of ZF4 cells was observed in irradiated cells and bystander cells compared to control cells. We observed that pre-irradiated cells which are then irradiated for a second time with the same doses contained significantly less γ-H2AX foci than in 24 h gamma-irradiated control cells. We also showed that bystander cells that have been in contact with the pre-irradiated cells and then irradiated alone present less γ-H2AX foci compared to the control cells. This radioadaptation effect is significantly more pronounced at the highest doses. To determine the factors involved in the early events of the bystander effect, we performed an extensive comparative proteomic study of the ZF4 secretomes upon irradiation. In the experimental conditions assayed here, we showed that the early events of bystander effect are probably not due to the secretion of specific proteins neither the oxidation of these secreted proteins. These results suggest that early bystander effect may be due probably to a combination of multiple factors. PMID:24667817

  10. Adaptation of cell renewal systems under continuous irradiation

    International Nuclear Information System (INIS)

    Fabrikant, J.I.

    1987-01-01

    There are adaptive changes in the proliferative characteristics of renewal tissues under the stress of continuous low-dose-rate irradiation which indicate that cell and tissue kinetics will have a considerable effect on the radiation response. Factors that determine the adaptation response involve cellular radiosensitivity, i.e. cell cycle effects, which determine the rate of cell sterilization and death, and compensatory cell proliferation and the capacity for regeneration, i.e. changes in the patterns of cell population kinetics, which determine the rate of cell birth. In rapidly dividing cell renewal systems, there is an effective elimination of damaged cells, with almost complete repair of cellular nonlethal damage. In slowly dividing renewal tissues, there is some repair or elimination of cellular radiation damage and the pattern of cell proliferation during regeneration is relatively little disturbed by prior continuous irradiation. Experimental data on intestinal epithelium, immunohematopoietic tissues, seminiferous epithelium and regenerating liver are presented. Discussion includes differences in adaptation to continuous low-dose-rate irradiation involving intracellular and extracellular control mechanisms which regulate cellular proliferation and differentiation and, thereby, control cell population levels and physiological function. 29 references

  11. Significance of apoptotic cell death after γ-irradiation

    International Nuclear Information System (INIS)

    Wu, H.G.; Kim, I.H.; Ha, S.W.; Park, C.I.

    2003-01-01

    Full text: The objectives of this study are to investigate the significance of apoptotic death compared to total cell death after γ-ray irradiation in human Hand N cancer cell lines and to find out correlation between apoptosis and radiation sensitivity. Materials and Method: Head and neck cancer cell lines (PCI-1, PCI-13, and SNU-1066), leukemia cell line (CCRF-CEM), and fibroblast cell line (LM217) as a normal control were used for this study. Cells were irradiated using Cs-137 animal experiment irradiator. Total cell death was measured by clonogenic assay. Annexin-V staining was used to detect the fraction of apoptotic death. The resulting data was analyzed with two parameters, apoptotic index (AI) and apoptotic fraction(AF). AI is ratio of apoptotic cells to total cells, and AF is ration of apoptotic cell death to mutant frequencytion ex(Number of apoptotic cells) / (Number of total cells counted) AF = {(AI) / (1-survival fraction)} x 100 (%) Results. Surviving fraction at 2 Gy (SF2) were 0.741, 0.544, 0.313, 0.302, and 0.100 for PCI-1, PCI-13, SNU-1066, CCRF-CEM, and LM217 cell lines, respectively. Apoptosis was detected in all cell lines. Apoptotic index reached peak value at 72 hours after irradiation in head and neck cancer cell lines, and that was at 24 hours in CCRF-CEM and LM217. Total cell death increased exponentially with increasing radiation dose from 0 Gy to 8 Gy, but the change was minimal in apoptotic index (Fig. 1.). Apoptotic fractions at 2 Gy were 46%, 48%, 46%, 24%, and 19% and at 6 Gy were 20%, 33%, 35%, 17%, and 20% for PCI-1, PCI-13, SNU-1066, CCRF-CEM, and LM217, respectively. The radioresistant cell lines showed more higher apoptotic fraction at 2 Gy (Table 1.), but there was not such correlation at 6 Gy. Conclusion: All cell lines used in this study showed apoptosis after irradiation, but time course of apoptosis was different from that of leukemia cell line and normal fibroblast cell line. Reproductive cell death was more important

  12. Effects of cell concentrations on the survival and repopulation of haemopoietic stem cells in irradiated bone marrow cell culture in vitro

    International Nuclear Information System (INIS)

    Fujitake, Hideki; Okamoto, Yuruko; Okubo, Hiroshi; Miyanomae, Takeshi; Kumagai, Keiko; Mori, K.J.

    1981-01-01

    Effects of cell concentrations on the survival and repopulation of haemopoietic stem cells after irradiation were studied in the long-term culture of mouse bone marrow cells in vitro. No difference was observed in the survival of the stem cells among cultures in which 0 - 10 7 cells were re-inoculated on the adherent cell colonies in the culture flask. Stem cells showed a significant proliferation within 1 week and the number of the stem cells exceeded the control in 3 weeks after irradiation in the cultures with less than 10 6 re-inoculated cells per flask. In contrast, there was a considerable delay in the onset of stem cell proliferation after irradiation in the culture with 10 7 cells per flask. Based on these results, a possibility that a stimulator of stem cell proliferation, released from irradiated stromal cells, is cancelled by an inhibitory factor produced by irradiated or unirradiated haemopoietic cells is postulated. (author)

  13. Stimulation of the proliferation of hemopoietic stem cells in irradiated bone marrow cell culture

    International Nuclear Information System (INIS)

    Mori, K.J.; Izumi, H.; Seto, A.

    1981-01-01

    Long-term hemopoiesis was established in bone marrow cell culture in vitro. This culture was shown to support the recovery proliferation of hemopoietic stem cells completely in vitro after irradiation. Hemopoietic stem cells were stimulated into proliferation in culture when normal bone marrow cells were overlayed on top of the irradiated adherent cell colonies. These results indicate that proliferation and differentiation of hemopoietic stem cells in vitro are also supported by stromahemopoietic cell interactions

  14. Ultrastructural morphometry of parotid acinar cells following fractionated irradiation

    International Nuclear Information System (INIS)

    Grehn, A.-L.; Gustafsson, H.; Franzen, L.; Thornell, L.-E.; Henriksson, R.

    1997-01-01

    The aim of this study was to evaluate the long term effects on the ultrastructure of parotid glands after fractionated irradiation. The method implemented involved 5 x 6 Gy and 5 x 8 Gy, Monday to Friday 6 MV photons. By unilateral irradiation, the contralateral parotid gland served as a control. Although irradiation diminished the acinar cell density in light microscopic sections from 75 to 32% after 5 x 8 Gy of irradiation, ultrastructural morphometry could not detect any statistically significant differences in acinar cell size, nuclear size, nuclear density, granule area, mean granule size, or granule density. In general, greater differences were seen between rats receiving 30 or 40 Gy, on both the irradiated and the control side, than between the irradiated side and the control side. This was interpreted as due to differences in the nutritional state of the animals. This analysis concluded that individual acinar cells that survive irradiation seem not to be damaged in the long term when evaluated at the ultrastructural level. The study further stresses the importance of adequate sampling sizes and the use of adequate controls. (author)

  15. Control of cell behavior on PTFE surface using ion beam irradiation

    International Nuclear Information System (INIS)

    Kitamura, Akane; Kobayashi, Tomohiro; Meguro, Takashi; Suzuki, Akihiro; Terai, Takayuki

    2009-01-01

    A polytetrafluoroethylene (PTFE) surface is smooth and biologically inert, so that cells cannot attach to it. Ion beam irradiation of the PTFE surface forms micropores and a melted layer, and the surface is finally covered with a large number of small protrusions. Recently, we found that cells could adhere to this irradiated PTFE surface and spread over the surface. Because of their peculiar attachment behavior, these surfaces can be used as biological tools. However, the factors regulating cell adhesion are still unclear, although some new functional groups formed by irradiation seem to contribute to this adhesion. To control cell behavior on PTFE surfaces, we must determine the effects of the outermost irradiated surface on cell adhesion. In this study, we removed the thin melted surface layer by postirradiation annealing and investigated cell behavior on the surface. On the surface irradiated with 3 x 10 16 ions/cm 2 , cells spread only on the remaining parts of the melted layer. From these results, it is clear that the melted layer had a capacity for cell attachment. When the surface covered with protrusions was irradiated with a fluence of 1 x 10 17 ions/cm 2 , the distribution of cells changed after the annealing process from 'sheet shaped' into multicellular aggregates with diameters of around 50 μm. These results indicate that we can control cell behavior on PTFE surfaces covered with protrusions using irradiation and subsequent annealing. Multicellular spheroids can be fabricated for tissue engineering using this surface.

  16. Cell cycle of spermatogonial colony forming stem cells in the CBA mouse after neutron irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Bootsma, A.L. (Rijksuniversiteit Utrecht (Netherlands). Academisch Ziekenhuis); Davids, J.A.G. (Netherlands Energy Research Foundation, Petten (Netherlands))

    1988-03-01

    In the CBA mouse testis, about 10% of the stem cell population is highly resistant to neutron irradiation (D/sub 0/, 0.75 Gy). Following a dose of 1.50 Gy these cells rapidly increase their sensitivity towards a second neutron dose and progress fairly synchronously through their first post-irradiation cell cycle. From experiments in which neutron irradiation was combined with hydroxyurea, it appeared that in this cycle the S-phase is less radiosensitive (D/sub 0/, 0.43 Gy) than the other phases of the cell cycle (D/sub 0/, 0.25 Gy). From experiments in which hydroxyurea was injected twice after irradiation, the speed of inflow of cells in S and the duration of S and the cell cycle could be calculated. Between 32 and 36 hr after irradiation cells start to enter the S-phase at a speed of 30% of the population every 12 hr. At 60 hr 50% of the population has already passed the S-phase while 30% is still in S. The data point to a cell cycle time of about 36 hr, while the S-phase lasts 12 hr at the most. (author).

  17. 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.

  18. Bystander apoptosis in human cells mediated by irradiated blood plasma

    International Nuclear Information System (INIS)

    Vinnikov, Volodymyr; Lloyd, David; Finnon, Paul

    2012-01-01

    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 0 -stage lymphocytes. Plasma was collected from healthy donors’ blood irradiated in vitro to 0–40 Gy acute γ-rays. Reporter PBM were separated from unirradiated blood with Histopaque and held in medium with the test plasma for 24 h at 37 °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.

  19. Squamous cell carcinoma in situ after irradiation

    International Nuclear Information System (INIS)

    Kambara, Takeshi; Nishiyama, Takafumi; Yamada, Rie; Nagatani, Tetsuo; Nakajima, Hiroshi; Sugiyama, Asami

    1997-01-01

    We report two cases with Squamous Cell Carcinoma (SCC) in situ caused by irradiation to hand eczemas, resistant to any topical therapies. Both of our cases clinically show palmer sclerosis and flexor restriction of the fingers, compatible to chronic radiation dermatitis. Although SCC arising in chronic radiation dermatitis is usually developed ten to twenty years after irradiation, in our cases SCC were found more than forty years after irradiation. (author)

  20. The inhibition of repair in UV irradiated human cells

    International Nuclear Information System (INIS)

    Collins, A.R.S.; Schor, S.L.; Johnson, R.T.

    1977-01-01

    Three different assay procedures are used to determine the effects of hydroxyurea on excision repair in UV-irradiated HeLa cells. At the cytological level, incubation of UV-irradiated metaphase cells with hydroxyurea caused chromosome decondensation. Using a modified alkaline sucrose gradient sedimentation technique involving minimal lysis before centrifugation, a marked retardation was found in the sedimentation of DNA from UV-irradiated cells incubated for a short period with hydroxyurea. The effect of hydroxyurea on the incorporation of [ 3 H]thymidine by UV-irradiated G1 cells was found to depend on the concentration of thymidine present in the medium. The results point to an inhibition of repair DNA synthesis by hydroxyurea (or deoxyadenosine), at the level of the supply of DNA precursors, i.e. in the same way that these agents inhibit semiconservative DNA synthesis. In the presence of these inhibitors, single-strand gaps accumulate in the DNA

  1. Morphological changes in human melanoma cells following irradiation with thermal neutrons.

    Science.gov (United States)

    Barkla, D H; Allen, B J; Brown, J K; Mountford, M; Mishima, Y; Ichihashi, M

    1989-01-01

    Morphological changes in two human melanoma cell lines, MM96 and MM418, following irradiation with thermal neutrons, were studied using light and electron microscopy. The results show that the response of human malignant melanoma cells to neutron irradiation is both cell line dependent and dose dependent, and that in any given cell line, some cells are more resistant to irradiation than others, thus demonstrating heterogeneity in respect to radiosensitivity. Cells repopulating MM96 flasks after irradiation were morphologically similar to the cells of origin whereas in MM418 flasks cells differentiated into five morphologically distinct subgroups and showed increased melanization. The results also show that radiation causes distinctive morphological patterns of damage although ultrastructural changes unique to the high LET particles released from boron 10 neutron capture are yet to be identified.

  2. Morphological changes in human melanoma cells following irradiation with thermal neutrons

    International Nuclear Information System (INIS)

    Barkla, D.H.; Allen, B.J.; Brown, J.K.; Mountford, M.; Mishima, Y.; Ichihashi, M.

    1989-01-01

    Morphological changes in two human melanoma cell lines, MM96 and MM418, following irradiation with thermal neutrons, were studied using light and electron microscopy. The results show that the response of human malignant melanoma cells to neutron irradiation is both cell line dependent and dose dependent, and that in any given cell line, some cells are more resistant to irradiation than others, thus demonstrating heterogeneity in respect to radiosensitivity. Cells repopulating MM96 flasks after irradiation were morphologically similar to the cells of origin whereas in MM418 flasks cells differentiated into five morphologically distinct subgroups and showed increased melanization. The results also show that radiation causes distinctive morphological patterns of damage although ultrastructural changes unique to the high LET particles released from boron 10 neutron capture are yet to be identified

  3. MeV single-ion beam irradiation of mammalian cells using the Surrey vertical nanobeam, compared with broad proton beam and X-ray irradiations

    Energy Technology Data Exchange (ETDEWEB)

    Prakrajang, K. [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Faculty of Science, Maejo University, Chiang Mai 50290 (Thailand); Jeynes, J.C.G.; Merchant, M.J.; Kirkby, K.; Kirkby, N. [Surrey Ion Beam Center, Faculty of Engineering and Physical Science, University of Surrey, Guildford Surrey, GU2 7XH (United Kingdom); Thopan, P. [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Yu, L.D., E-mail: yuld@fnrf.science.cmu.ac.th [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Thailand Center of Excellence in Physics, Commission on Higher Education, 328 Si Ayutthaya Road, Bangkok 10400 (Thailand)

    2013-07-15

    Highlights: •Recently completed nanobeam at the Surrey Ion Beam Centre was used. •3.8-MeV single and broad proton beams irradiated Chinese hamster cells. •Cell survival curves were measured and compared with 300-kV X-ray irradiation. •Single ion irradiation had a lower survival part at ultra-low dose. •It implies hypersensitivity, bystander effect and cell cycle phase of cell death. -- Abstract: As a part of a systematic study on mechanisms involved in physical cancer therapies, this work investigated response of mammalian cells to ultra-low-dose ion beam irradiation. The ion beam irradiation was performed using the recently completed nanobeam facility at the Surrey Ion Beam Centre. A scanning focused vertical ion nano-beam was applied to irradiate Chinese hamster V79 cells. The V79 cells were irradiated in two different beam modes, namely, focused single ion beam and defocused scanning broad ion beam of 3.8-MeV protons. The single ion beam was capable of irradiating a single cell with a precisely controlled number of the ions to extremely low doses. After irradiation and cell incubation, the number of surviving colonies as a function of the number of the irradiating ions was measured for the cell survival fraction curve. A lower survival for the single ion beam irradiation than that of the broad beam case implied the hypersensitivity and bystander effect. The ion-beam-induced cell survival curves were compared with that from 300-kV X-ray irradiation. Theoretical studies indicated that the cell death in single ion irradiation mainly occurred in the cell cycle phases of cell division and intervals between the cell division and the DNA replication. The success in the experiment demonstrated the Surrey vertical nanobeam successfully completed.

  4. Appearance of thymic nurse cells after gamma irradiation

    International Nuclear Information System (INIS)

    Mulder, A.H.; Bekkum, D.W. van

    1983-01-01

    Since prothymocytes home from the bone marrow to the thymus, it was tested in the mouse whether prothymocytes could be recaptured from thymic nurse cells (TNC). Bone marrow cells were labelled with the red fluorescing anthracycline daunomycin and varying numbers (up to 25 x 10 6 nucleated bone marrow cells) were injected into lethally irradiated recipients. At several time intervals after transplantation (up to 24 hours), thymuses were removed and the TNCs were isolated. No specific red fluorescence was found within the TNCs. These experiments were repeated with supravital compounds at concentrations which have been shown not to affect viability, homing pattern and function. Again, no specific fluoresence was found in the TNC after transplantation of labelled bone marrow into irradiated mice. The relationship between the dose of total body gamma irradiation and the time after irradiation was investigated. Maximal numbers of TNCs were found at 6 hours after irradiation with 4 Gy. Eight to 12 hours after irradiation, the number of TNCs isolated decreased and had returned to preirradiation levels at 24 hours. The relation between TBI dose and the number of TNCs per thymus is shown. The number determined at 3 hours increased with the dose to reach a maximum at 4 Gy. The authors later studied the morphology of the TNCs isolated at 4 to 6 hours after irradiation. On electron microscopic examination, signs of degeneration and death of the enclosed thymocytes was detected. (Auth.)

  5. Late post-irradiation phenomena in mammalain cell populations. Pt. 2. Intraclonal recovery in sublines isolated from X-irradiated L5178Y-S cell populations

    International Nuclear Information System (INIS)

    Beer, J.Z.

    1975-01-01

    Clonal analysis of L5178Y-S cell populations irradiated with 300 rads of X-rays indicates occurence of cell sublines with considerably prolonged mean doubling times up to 22 h as compared to 10-11 h for control. Subsequent observations of growth of the handicapped sublines derived from single cells showed capability of all more than 100 studied sublines to recover normal proliferative activity. This process of intraclonal recovery required in many cases longer periods of time, corresponding to many tens, sometimes more than 200, generations. Late intraclonal recovery was further analysed by subcloning. It was found that although cytochemically assayed viability of the handicapped sublines was normal, cloning efficiency strongly depended on the stage of the recovery process. The recovery processes occuring in clones isolated from irradiated cell populations were compared with analogous processes occuring in slowly growing sublines isolated from non-irradiated cell cultures. Marked differences in kinetics of these processes show that either they are different in sublines derived from irradiated and non-irradiated cell populations or that the mechanisms of the late intraclonal recovery are affected by radiation. The results presented allow to conclude that gradual post-irradiation recovery of growth depends primarily on formation, in the developing populations, of cells with higher proliferative activities. Possible nature of the recovery processes is discussed in the light of available information on mammalian somatic cell variants with altered drug or temperature sensitivity, or with nutritional requirements. A sequence is proposed of changes leading from radiation-induced disturbance of the normably existing equilibrium between three basic cell subpopulations to ultimate restoration of this equilibrium. (author)

  6. Dysfunction of irradiated thymus for the development of helper T cells

    International Nuclear Information System (INIS)

    Amagai, T.; Kina, T.; Hirokawa, K.; Nishikawa, S.; Imanishi, J.; Katsura, Y.

    1987-01-01

    The development of cytotoxic T cells and helper T cells in an intact or irradiated thymus was investigated. C57BL/6 (H-2b, Thy-1.2) mice were whole body-irradiated, or were irradiated with shielding over either the thymus or right leg and tail, and were transferred with 1.5 X 10(7) bone marrow cells from B10.Thy-1.1 mice (H-2b, Thy-1.1). At various days after reconstitution, thymus cells from the recipient mice were harvested and a peanut agglutinin low-binding population was isolated. This population was further treated with anti-Thy-1.2 plus complement to remove host-derived cells and was assayed for the frequency of cytotoxic T cell precursors (CTLp) and for the activity of helper T cells (Th). In the thymus of thymus-shielded and irradiated mice, Th activity reached normal control level by day 25, whereas CTLp frequency remained at a very low level during these days. In the thymus of whole body-irradiated mice, generation of CTLp was highly accelerated while that of Th was retarded, the period required for reconstitution being 25 days and more than 42 days for CTLp and Th, respectively. Preferential development of CTLp was also seen in right leg- and tail-shielded (L-T-shielded) and irradiated recipients. Histological observation indicated that Ia+ nonlymphoid cells were well preserved in the thymus of thymus-shielded and irradiated recipients, whereas in L-T-shielded and irradiated recipients, such cells in the medulla were markedly reduced in number. These results suggest strongly that the generation of Th but not CTLp is dependent on radiosensitive thymic component(s), and that such components may represent Ia+ cells themselves in the medulla or some microenvironment related to Ia+ cells

  7. Herpes virus and viral DNA synthesis in ultraviolet light-irradiated cells

    Energy Technology Data Exchange (ETDEWEB)

    Coppey, J; Nocentini, S [Institut du Radium, 75 - Paris (France). Lab. Curie

    1976-07-01

    The rate of virus DNA synthesis and the production of infectious virus are impaired in stationary monkey kidney CV-I cells irradiated with u.v. before infection with herpes simplex virus (HSV). The inhibition of HSV multiplication is due to u.v.-induced damage in cell DNA. CV-I cells recover their capacity to support HSV growth during the 40 to 48 h after irradiation, and the final virus yield is enhanced by factor of 10. The time course of the recovery is similar to that of the excision repair process occurring in u.v.-irradiated mammalian cells. Caffeine, hydroxyurea and cycloheximide inhibit the recovery. Fluorodeoxyuridine is without effect. A small but significant amount of labelled dThd coming from irradiated cell DNA is incorporated into virus DNA. HSV specified thymidine kinase seems to be more effective for virus DNA synthesis in irradiated than in control cells.

  8. Enhanced micronucleus formation in the descendants of {gamma}-ray-irradiated tobacco cells: Evidence for radiation-induced genomic instability in plant cells

    Energy Technology Data Exchange (ETDEWEB)

    Yokota, Yuichiro, E-mail: yokota.yuichiro@jaea.go.jp [Life Science and Biotechnology Division, Quantum Beam Science Directorate, Japan Atomic Energy Agency, 1233 Watanuki-machi, Takasaki, Gunma 370-1292 (Japan); Funayama, Tomoo; Hase, Yoshihiro [Life Science and Biotechnology Division, Quantum Beam Science Directorate, Japan Atomic Energy Agency, 1233 Watanuki-machi, Takasaki, Gunma 370-1292 (Japan); Hamada, Nobuyuki [Radiation Safety Research Center, Nuclear Technology Research Laboratory, Central Research Institute of Electric Power Industry, 2-11-1 Iwado-kita, Komae, Tokyo 201-8511 (Japan); Kobayashi, Yasuhiko; Tanaka, Atsushi; Narumi, Issay [Life Science and Biotechnology Division, Quantum Beam Science Directorate, Japan Atomic Energy Agency, 1233 Watanuki-machi, Takasaki, Gunma 370-1292 (Japan)

    2010-09-10

    Ionizing radiation-induced genomic instability has been documented in various end points such as chromosomal aberrations and mutations, which arises in the descendants of irradiated mammalian or yeast cells many generations after the initial insult. This study aimed at addressing radiation-induced genomic instability in higher plant tobacco cells. We thus investigated micronucleus (MN) formation and cell proliferation in tobacco cells irradiated with {gamma}-rays and their descendants. In {gamma}-irradiated cells, cell cycle was arrested at G{sub 2}/M phase at around 24 h post-irradiation but released afterward. In contrast, MN frequency peaked at 48 h post-irradiation. Almost half of 40 Gy-irradiated cells had MN at 48 h post-irradiation, but proliferated as actively as sham-irradiated cells up to 120 h post-irradiation. Moreover, the descendants that have undergone at least 22 generations after irradiation still showed a two-fold MN frequency compared to sham-irradiated cells. This is the direct evidence for radiation-induced genomic instability in tobacco cells.

  9. Systematization of the Mechanism by Which Plasma Irradiation Causes Cell Growth and Tumor Cell Death

    Science.gov (United States)

    Shimizu, Nobuyuki

    2015-09-01

    New methods and technologies have improved minimally invasive surgical treatment and saved numerous patients. Recently, plasma irradiation has been demonstrated that might be useful in medical field and the plasma irradiation device is expected to become practically applicable. Mild plasma coagulator showed some advantages such as hemostasis and adhesion reduction in experimental animal model, but the mechanism of plasma irradiation remains unclear. Our study group aim to clarify the mechanism of plasma irradiation effects, mainly focusing on oxidative stress using cultured cell lines and small animal model. First, a study using cultured cell lines showed that the culture medium that was activated by plasma irradiation (we called this kind of medium as ``PAM'' -plasma activated medium-) induced tumor cell death. Although this effect was mainly found to be due to hydrogen peroxide, the remaining portion was considered as the specific effect of the plasma irradiation and we are now studying focusing on this effect. Second, we established a mouse intra-peritoneal adhesion model and checked biological reaction that occurred in the adhesion part. Histopathological study showed inflammatory cells infiltration into adhesion part and the expression of PTX3 that might involve tissue repair around adhesion part. We also confirmed that cytokines IL-6 and IL-10 might be useful as a marker of adhesion formation in this model. Applying ``PAM'' or mild plasma irradiation in this model, we examine the effects of plasma on inflamed cells. The samples in these experiments would be applied to targeted proteomics analysis, and we aim to demonstrate the systematization of the cell's reaction by plasma irradiation.

  10. Effects of x-irradiation on growth of vascular smooth muscle cells

    International Nuclear Information System (INIS)

    Dzoga, K.F.; Dimitrievich, G.S.; Sutton, H.G.; Griem, M.L.

    1984-01-01

    Effects of x-irradiation doses ranging from 0-2000 rads on vascular smooth muscle cells were measured. Explant cultures were from the medial layers of aortas from New Zealand rabbits. X-irradiation was delivered to narrow mediastinal port using a 250 kV Maxitron at a rate of 80 rads/min. and a S-C distance of 60 cm. Explantation was done either immediately following radiation or five days later. Two parameters were used to determine post-irradiation growth potential of these cells: number of outgrowing cells per seeded explant and size and number of cells/culture. Results were expressed as fraction of control. Irradiation immediately before explantation reduced number of cells/ explant 10% for 250 rads and over 50% for 500 rads. Doses of 1000 rads and over resulted in reductions of over 70% in number of growing explants and culture size. When five days were allowed to elapse between x-irradiation and explantation the same parameters were not significantly affected for doses of 500 rads or less. Doses of 1000 rads resulted in a reduction in number of cells of 40% and 2000 rads of over 80%. These results suggest the presence of a population of vascular repair cells five days following irradiation treatment. The nature of these cells is discussed

  11. Irradiation effects on high efficiency Si solar cells

    International Nuclear Information System (INIS)

    Nguyen Duy, T.; Amingual, D.; Colardelle, P.; Bernard, J.

    1974-01-01

    By optimizing the diffusion parameters, high efficiency cells are obtained with 2ohmsxcm (13.5% AMO) and 10ohmsxcm (12.5% AMO) silicon material. These new cells have been submitted to radiation tests under 1MeV, 2MeV electrons and 2.5MeV protons. Their behavior under irradiation is found to be dependent only on the bulk material. By using the same resistivity silicon, the rate of degradation is exactly the same than those of conventional cells. The power increase, due to a better superficial response of the cell, is maintained after irradiation. These results show that new high efficiency cells offer an E.O.L. power higher than conventional cells [fr

  12. Effects of irradiance and prey deprivation on growth, cell carbon and photosynthetic activity of the freshwater kleptoplastidic dinoflagellate Nusuttodinium (= Gymnodinium) aeruginosum (Dinophyceae).

    Science.gov (United States)

    Drumm, Kirstine; Liebst-Olsen, Mette; Daugbjerg, Niels; Moestrup, Øjvind; Hansen, Per Juel

    2017-01-01

    The freshwater dinoflagellate Nusuttodinium aeruginosum lacks permanent chloroplasts. Rather it sequesters chloroplasts as well as other cell organelles, like mitochondria and nuclei, from ingested cryptophyte prey. In the present study, growth rates, cell production and photosynthesis were measured at seven irradiances, ranging from 10 to 140 μmol photons m-2s-1, when fed the cryptophyte Chroomonas sp. Growth rates were positively influenced by irradiance and increased from 0.025 d-1 at 10 μmol photons m-2s-1 to maximum growth rates of ~0.3 d-1 at irradiances ≥ 40 μmol photons m-2s-1. Similarly, photosynthesis ranged from 1.84 to 36.9 pg C cell-1 h-1 at 10 and 140 μmol photons m-2s-1, respectively. The highest rates of photosynthesis in N. aeruginosum only corresponded to ~25% of its own cell carbon content and estimated biomass production. The measured rates of photosynthesis could not explain the observed growth rates at high irradiances. Cultures of N. aeruginosum subjected to prey starvation were able to survive for at least 27 days in the light. The sequestered chloroplasts maintained their photosynthetic activity during the entire period of starvation, during which the population underwent 4 cell divisions. This indicates that N. aeruginosum has some control of the chloroplasts, which may be able to replicate. In conclusion, N. aeruginosum seems to be in an early stage of chloroplast acquisition with some control of its ingested chloroplasts.

  13. A Study on Cell Size of Irradiated Spacer Grid for PWR Fuel

    International Nuclear Information System (INIS)

    Jin, Y. G.; Kim, G. S.; Ryu, W. S. and others

    2014-01-01

    The spacer grids supporting the fuel rods absorb vibration impacts due to the reactor coolant flow, and grid spring force decreases under irradiation. This reduction of contact force might cause grid-to-rod fretting wear. The fretting failure of the fuel rod is one of the recent significant issues in the nuclear industry from an economical as well as a safety concern. Thus, it is important to understand the characteristics of cell spring behavior and the change in size of grid cells for an irradiated spacer grid. In the present study, the dimensional measurement of a spacer grid was conducted to investigate the cell size of an irradiated spacer grid in a hot cell at IMEF (Irradiated Materials Examination Facility) of KAERI. To evaluate the fretting wear performance of an irradiated spacer grid, hot cell tests were carried out at IMEF of KAERI. Hot cell examinations include dimensional measurements for the irradiated spacer grid. The change of cell sizes was dependent on the direction of the spacer grids, leading to significant gap variations. It was found that the change in size of the cell springs due to irradiation-induced stress relaxation and creep during the fuel residency in the reactor core affect the contact behavior between the fuel rod and the cell spring

  14. Effects of 3-AB on PARP expression of Hela cells and apoptosis and cell cycle progression of Hela cells after X-rays irradiation

    International Nuclear Information System (INIS)

    Du Xiang; Zhao Hongguang; Guo Wei; Gong Shouliang; Wang Wen

    2007-01-01

    Objective: To study the changes of apoptosis and cell cycle progression of Hela cells after the poly (ADP- ribose) polymerase (PARP) was inhibited by its inhibitor 3-aminobenzamid (3-AB) and the mechanisms of PARP interaction with Hela cells damaged by irradiation. Methods: Hela cell line was used. Flow cytometry (FCM) was used to examine the PARP expression of control and 3 AB groups at 0, 2, 4, 8, 12 h alter administration with 5 mmol·L -1 3-AB. The percentage of apoptotic cells and cell cycle progression ol control, irradiation, 3-AB plus irradiation groups were measured with FCM at 2, 8, 12, 24 h after exposure to 2 Gy irradiation following administration with 5 mmol·L -1 3-AB. Results: The percentage of Hela cells with positive expression of PARP protein decreased after administration with 3-AB and there was significant difference between 3-AB plus irradiation group and control group (P 2 cells in the 3-AB plus irradiation group were lower than those in the irradiation group (P 2 arrest induced by irradiation. (authors)

  15. Cell death induced by gamma irradiation of developing skeletal muscle

    International Nuclear Information System (INIS)

    Olive, M.; Blanco, R.; Rivera, R.; Cinos, C.; Ferrer, I.

    1995-01-01

    Newborn Sprague-Dawley rats were exposed to a single dose of 2 Gy gamma rays and killed from 6 h to 5 d later. Increased numbers of dying cells, characterised by their extreme chromatin condensation and often nuclear fragmentation were seen in skeletal muscle 6 h after irradiation. Dying cells decreased to nearly normal values 48 h later. In situ labelling of nuclear DNA fragmentation identified individual cells bearing fragmented DNA. The effects of gamma rays were suppressed following cycloheximide i.p. at a dose of 1 μg/g body weight given at the time of irradiation. Taken together, the present morphological and pharmacological results suggest that gamma ray induced cell death in skeletal muscle is apoptotic, and that the process is associated with protein synthesis. Finally, proliferating cell nuclear antigen-immunoreactive cells, which were abundant in control rats, decreased in number 48 h after irradiation. However, a marked increase significantly above normal age values was observed at the 5th day, thus suggesting that regeneration occurs following irradiation-induced cell death in developing muscle. (author)

  16. Aggregation patterns of fetal rat brain cells following exposure to X-irradiation

    International Nuclear Information System (INIS)

    Shoji, R.; Suzuki, K.; Lee, I.P.

    1980-01-01

    In our search for a simplified in vitro test system to assess the teratogenic effects of physical factors, we studied the effects of total maternal body X-irradiation on aggregation patterns of enzymatically isolated fetal rat brain cells and on ultrastructural aggregate changes. The fetal brain cells were derived from day 14 gestation fetuses of pregnant Sprague-Dawley (CD strain) rats exposed to X-irradiation (25 - 200 R) one hour prior to sacrifice. Notable changes in the cell aggregates following X-irradiation included a reduction in cell aggregate size and an increase in number. The frequency of cell aggregates was higher in the treated than in the control group, and the mean diameter of cell aggregates was inversely related to increasing X-irradiation doses. Transmission electron microscopy revealed in isolated cells features of degenerative process which were similar to those found in intact fetal brain lesions caused by maternal X-irradiation. Furthermore, scanning electron microscopy revealed that inhibition of cell aggregation following X-irradiation could probably be attributed to inhibition of membrane filopodia development and a consequent failure of cell aggregates to fuse into a greater cell aggregate mass. These results suggest that the membrane factors which influence cell aggregation may be a useful parameter to assess early effects of X-irradiation-induced brain deformity. Presently, the cell aggregation culture system is being further evaluated as a short term test system for environmental teratogens

  17. RNA and protein synthesis of irradiated Ehrlich ascites tumour cells. Pt. 2

    International Nuclear Information System (INIS)

    Skog, S.; Tribukait, B.; Nygard, O.; Wenner-Gren-Center foer Vetenskaplig Forskning, Stockholm

    1985-01-01

    Poly(A)-containing RNA (m-RNA) was studied in in vivo growing Ehrlich ascites tumour cells following a roentgen irradiation dose of 5 Gy. m-RNA increased significantly during the first 12 hours after irradiation. Thus, the observed decrease in protein synthesis rate during this time seems not to be due to radiation induced changes at the transcriptional level. The protein synthesis rate of in vivo irradiated cells incubated in vitro in culture medium was unchanged. On the other hand, the protein synthesis rate of non-irradiated cells incubated in vitro in ascites fluid from irradiated animals was decreased. We concluded that factor(s) inhibiting protein synthesis or the lack of factor(s) promoting protein synthesis in the ascites fluid is(are) of significance for the reduced protein synthesis of tumour cells found in irradiated in vivo growing cells. (orig.)

  18. Combined effect of x irradiation and cell-mediated immune reaction

    International Nuclear Information System (INIS)

    Song, C.W.; Guertin, D.P.

    1978-01-01

    The combined effect of radiation and cell-mediated immune reaction on tumor cells was investigated in vitro. Mastocytoma P815-X2 cells of DBA mice either were irradiated first and subjected to immune lysis by immune splenic lymphocytes of C57Bl mice, or the tumor cells were subjected to immune reaction first and then irradiated. Cell survival was quantitated by colony formation in soft agar medium. It was observed that cellular immune damage to tumor cells did not influence the response of tumor cells to subsequent radiation. Irradiation of tumor cells first, followed by subjection of the cells to cellular immune reaction, slightly enhanced the death of the tumor cells. It appears that this enhanced death might have resulted from a relative increase in the ratio of the number of cytotoxic immune cells to the number of target tumor cells in the incubation mixture as a consequence of the decrease in the number of viable tumor cells by radiation

  19. Cytofluorometric analysis of proliferation kinetics of cerebral cells of prenatally irradiated rats

    International Nuclear Information System (INIS)

    Borovitskaya, A.E.; Evtushenko, V.I.; Tokalov, S.V.; Yagunov, A.S.; Khanson, K.P.

    1994-01-01

    Prenatal irradiation of humans or animals causes serious and life-long functional and structural damage to the central nervous system. Irradiation of a fetus decreases its brain mass, an effect accompanied by a broad spectrum of disorders in higher nervous activity and behavior. The extent of cerebral damage depends on the kind of radiation, dosage, and on the stage of embryonic development. In rodents, the most serious damage resulted from the irradiation of 15-18 day embryos. Prenatally irradiated animals had pronounced morphological and biochemical changes within the brain, as well as serious deviations from normal behavior. The cerebral structural-functional disorders are known to result from the destruction of irradiated cells, primarily of neuroblasts. The authors used flow cytofluorometry to study the proliferation of cerebral cells at various ontogenetic stages in rats antenatally exposed to γ-neutron radiation. For one-week old animals, the postradiation changes of cell distributions over the cell cycle were found only within the cerebellum. This likely reflects the compensatory cell proliferation, because delayed postnatal development is typical of this part of the brain. There were no detectable differences in brain cytokinetics between two week-old control and irradiated animals. Most of the brain cells (except a limited population of glia, endothelial cells, and cells of the secondary germinal layer) are in the resting state during this period, and radiation does not change their cell cycle distributions. Thus, the increasing occurrence of the S + G 2 + M phases in the cell cycle observed in newborn irradiated rats may reflect the enhanced proliferation of nervous cells surviving the irradiation. However, this compensatory proliferation does not prevent the brain mass from being deficient in the postnatal development of prenatally irradiated animals

  20. RBE of cells irradiated by carbon ions

    International Nuclear Information System (INIS)

    Li Wenjian; Zhou Guangming; Wei Zengquan; Wang Jufang; Dang Bingrong; Li Qiang; Xie Hongmei

    2002-01-01

    The mouse melanoma cells (B16), human cervical squamous carcinoma cells (HeLa), Chinese hamster pulmonary cells V79, and human hepatoma cells (SMMC-7721) were collected for studying. The cells of 5 x 10 5 /ml were seeded in 35 mm diameter petri dish and allowed to grow one day, and then the medium in petri dishes was removed away, the cells were washed once with phosphate-buffered saline (PBS), petri dishes was covered with 4μm thickness Mylar film. The cells were irradiated by 12 C ion beam with LETs of 125.5, 200, 700 keV/μm in water generated from HIRFL (Heavy Ion Research Facility in Lanzhou). For 60 Co γ-ray experiment, the cells of 5 x 10 4 /ml were grown in 20 ml culture flasks including 1.5 ml cell suspension and directly used for irradiation. Following irradiation, the cells were trypsinized, counted, plated at appropriate densities in growth medium and then seeded in 60 mm diameter culture dishes. Each dish was filled 4 ml standard medium, and incubated for 8-12 days at 37 degree C incubator containing 5% CO 2 . The cultures were then rinsed with PBS buffer at pH 6.8, fixed with Carnoy's fluid, stained for 8 min with Giemsa (1:20, pH 6.8), and colonies containing more than 50 cells were scored. Their relative biological effectivenesses (RBE) were investigated. The results show that RBE depends on cellular types and increases with increasing of cellular survival level when LET is at 125.5 keV/μm, and decreases with increasing LET when LET ≥ 125.5 keV/μm

  1. Effects of x-irradiation on cell kinetics of oral epithelium in mice

    International Nuclear Information System (INIS)

    Jinnouchi, Kenichi

    1982-01-01

    The acute radiation effects on the tongue and lip mucosa epithelium were cytokinetically investigated after the local irradiation at the head part of C 3 Hf/He mice with single dose of 516 mC/kg(2000R) of X rays. The microautoradiographic study was performed for these two kinds of oral epithelium at various times after the pulse-labeling with 3 H-thymidine, which followed immediately after the irradiation. The cell kinetics of irradiated as well as unirradiated basal cells were investigated by observing the changes in frequencies of the labeled cells and the labeled mitoses in the epithelium along the time course after irradiation. The results of the analysis of the percent frequencies of mitotic cells as a function of time after the labeling and the irradiation showed that the movement of the labeled cells were blocked at G 2 phase for about 6 hr and that the cell cycle time after the 1st post irradiation mitoses became shorter than that of the unirradiated cells. However, no change was found in the migration rate of the tongue epithelium, i.e., the time required for labeled cells to migrate from basal cell layer to prickle-granular cell layer. On the other hand, only 25% of labeled cells in the lip mucosa epithelium migrated into prickle-granular cell layer until 40 hr after irradiation, and it was hardly observed that the labeled cells moved into mitotic phase. These results suggest that basal cell of the lip mucosa is more radiosensitive than that of the tongue epithelium. (author)

  2. The irradiation effects of ultraviolet rays on Leptospira cells

    International Nuclear Information System (INIS)

    Maeda, Hidezo

    1982-01-01

    The irradiation effects of ultraviolets rays (UV) on leptospira cells were investigated. Four serovar strains of Genus Leptospira ; L. copenhageni, L. canicola, L. biflexa and L. illini were used. A sterilization lamp (Toshiba-GL-15) were lighted at intervals of 90mm on the sample fluid for several minutes. Loss of motility, survival growth and morphological damages were recognized under several conditions. The medium conditions were important, that is, the Korthof's medium was less effective than phosphate buffered saline (PBS). The irradiation time was also important, that is, L. canicola cells in PBS lost their motility and survive ability within 300sec. of irradiation, however, much more time, such as 1.200sec. was necessary in Korthof's medium. This phenomenon may be depended upon defensibility of albumin in the latter. Among the strains, L. biflexa cells showed the highest resistance in loss of motility and survive ability, and other three strains were inferior. The remarkable efects of cellular structures were also seen in the materials with 30 min. of irradiation, in both immediate time or after 24h incubation. The damages observed after 24th of irradiation were much more drastic than those of immediate time. No effect could be seen on the cells suspended in the Korthof's medium irradiated for 24h. Regarding morphological effect, there appeared relaxation of helical body, spherical body and semighost as the immediate changes. Structural damages were recognized as the collapse of cell body, such as scattering of capsule, release of axial flagella, loss or change of cytoplasmic density and break down of wall membrane complex. These phenomena were regarded as the indirect effects of UV-irradiation and autolysis in a post-mortem change. (author)

  3. The role of prophylactic cranial irradiation in regionally advanced non-small cell lung cancer. A Southwest Oncology Group Study

    Energy Technology Data Exchange (ETDEWEB)

    Rusch, V.W.; Griffin, B.R.; Livingston, R.B. (Univ. of Washington, Seattle (USA))

    1989-10-01

    Lung cancer is the most common malignant disease in the United States. Only the few tumors detected very early are curable, but there has been some progress in the management of more advanced non-small cell lung cancer, particularly in regionally inoperable disease. Prevention of central nervous system relapse is an important issue in this group of patients because brain metastases ultimately develop in 20% to 25% of them. Seventy-three patients with regionally advanced non-small cell lung cancer were entered into a Phase II trial of neutron chest radiotherapy sandwiched between four cycles of chemotherapy including cisplatin, vinblastine, and mitomycin C. Prophylactic cranial irradiation was administered concurrently with chest radiotherapy (3000 cGy in 10 fractions in 15 patients; 3600 cGy in 18 fractions in the remaining 50 patients). Patients underwent computed tomographic scan of the brain before treatment and every 3 months after treatment. The initial overall response rate was 79%, but 65 of the 73 patients have subsequently died of recurrent disease. Median follow-up is 9 months for all 73 patients and 26 months for eight long-term survivors. No patient who completed the prophylactic cranial irradiation program had clinical or radiologic brain metastases. Toxic reactions to prophylactic cranial irradiation included reversible alopecia in all patients, progressive dementia in one patient, and possible optic neuritis in one patient. Both of these patients received 300 cGy per fraction of irradiation. The use of prophylactic cranial irradiation has been controversial, but its safety and efficacy in this trial supports its application in a group of patients at high risk for central nervous system relapse. Further evaluation of prophylactic cranial irradiation in clinical trials for regionally advanced non-small cell lung cancer is warranted.

  4. Effect of irradiation on human T-cell proliferation: low dose irradiation stimulates mitogen-induced proliferation and function of the suppressor/cytotoxic T-cell subset

    International Nuclear Information System (INIS)

    Gualde, N.; Goodwin, J.S.

    1984-01-01

    Unfractionated human T cells exposed to 10-50 rad of X irradiation incorporated less [ 3 H]thymidine than nonirradiated T cells when subsequently cultured with PHA or Con A. The cytotoxic/suppressor T-cell subset, isolated as either OKT8(+) or OKT4(-) cells, demonstrated significantly enhanced [ 3 H]thymidine incorporation in PHA- or Con A-stimulated cultures after exposure to 10-50 rad, compared to unirradiated cells, while the proliferation of the OKT4(+) helper/inducer subset was inhibited by low dose irradiation. It has been previously reported that approximately 30% of the cytotoxic/suppressor subset also stains with OKM1. When the cytotoxic/suppressor subset was further subdivided into OKT4(-), OKM1(+), and OKT4(-), OKM1(-) cells, proliferation of the OKT4(-), OKM1(+) population was inhibited by exposure to 25 rad while proliferation of the OKT4(-), OKM1(-) population was stimulated. The increase in proliferation of the cytotoxic/suppressor T-cell subset after low dose irradiation is paralleled by an increase in suppressor activity of these cells. T cells exposed to 25 rad and then cultured with Con A for 48 hr caused greater inhibition of IgG production when added to fresh autologous lymphocytes stimulated by pokeweed mitogen than did unirradiated cells. Thus, low dose irradiation enhances both the proliferation and function of the human suppressor T-cell subset

  5. Stimulation of Hepatoma Cell Invasiveness and Metastatic Potential by Proteins Secreted From Irradiated Nonparenchymal Cells

    Energy Technology Data Exchange (ETDEWEB)

    Zhou Leyuan [Department of Radiation Oncology, Zhongshan Hospital, Fudan University, Shanghai (China); Wang Zhiming [Department of Medical Oncology, Zhongshan Hospital, Fudan University, Shanghai (China); Gao Yabo [Department of Radiation Oncology, Zhongshan Hospital, Fudan University, Shanghai (China); Wang Lingyan [Experimental Research Center, Zhongshan Hospital, Fudan University, Shanghai (China); Zeng Zhaochong, E-mail: zeng.zhaochong@zs-hospital.sh.cn [Department of Radiation Oncology, Zhongshan Hospital, Fudan University, Shanghai (China)

    2012-11-01

    Purpose: To determine whether factors secreted by irradiated liver nonparenchymal cells (NPCs) may influence invasiveness and/or metastatic potential of hepatocellular carcinoma (HCC) cells and to elucidate a possible mechanism for such effect. Methods and Materials: Primary rat NPCs were cultured and divided into irradiated (10-Gy X-ray) and nonirradiated groups. Forty-eight hours after irradiation, conditioned medium from irradiated (SR) or nonirradiated (SnonR) cultures were collected and added to sublethally irradiated cultures of the hepatoma McA-RH7777 cell line. Then, hepatoma cells were continuously passaged for eight generations (RH10Gy-SR and RH10Gy-SnonR). The invasiveness and metastatic potential of McA-RH7777, RH10Gy-SnonR, and RH10Gy-SR cells were evaluated using an in vitro gelatinous protein (Matrigel) invasion and an in vivo metastasis assay. In addition, SR and SnonR were tested using rat cytokine antibody arrays and enzyme-linked immunosorbent assay (ELISA). Results: In vitro gelatinous protein invasion assay indicated that the numbers of invading cells was significantly higher in RH10Gy-SR (40 {+-} 4.74) than in RH10Gy-SnonR (30.6 {+-} 3.85) cells, and lowest in McA-RH7777 (11.4 {+-} 3.56) cells. The same pattern was observed in vivo in a lung metastasis assay, as evaluated by number of metastatic lung nodules seen with RH10Gy-SR (28.83 {+-} 5.38), RH10Gy-SnonR (22.17 {+-} 4.26), and McA-RH7777 (8.3 {+-} 3.8) cells. Rat cytokine antibody arrays and ELISA demonstrated that metastasis-promoting cytokines (tumor necrosis factor-{alpha} and interleukin-6), circulating growth factors (vascular endothelial growth factor and epidermal growth factor), and metalloproteinases (MMP-2 and MMP-9) were upregulated in SR compared with SnonR. Conclusions: Radiation can increase invasiveness and metastatic potential of sublethally irradiated hepatoma cells, and soluble mediators released from irradiated NPCs promote this potential. Increased secretion of

  6. Anomalous effects in silicon solar cell irradiated by 1-MeV protons

    Science.gov (United States)

    Kachare, R.; Anspaugh, B. E.

    1989-01-01

    Several silicon solar cells having thicknesses of approximately 63 microns, with and without back-surface fields (BSF), were irradiated with 1-MeV protons having fluences between 10 to the 10th and 10 to the 12th sq cm. The irradiations were performed using both normal and isotropic incidence on the rear surfaces of the cells. It was observed that after irradiation with fluences greater than 10 to the 11th protons/sq cm, all BSF cells degraded at a faster rate than cells without BSF. The irradiation results are analyzed using a model in which irradiation-induced defects in the BSF region are taken into account. Tentatively, it is concluded that an increase in defect density due to the formation of aluminum and proton complexes in BSF cells is responsible for the higher-power loss in the BSF cells compared to the non-BSF cells.

  7. Differential effect of procaine on irradiated mammalian cells in culture

    International Nuclear Information System (INIS)

    Djordjevic, B.

    1979-01-01

    HeLa and V-79 Chinese hamster cells temporarily stored in ampoules were treated with the local anesthetic procaine. Postirradiation treatment increased lethality in HeLa cells depending on drug concentration, duration of treatment, and cell density, as measured by colony-forming ability upon plating. If present during irradiation only, procaine protected from irradiation. In V-79 cells, procaine potentiated radiation lethality only in freshly trypsinized cells. Procaine effect was thus cell type specific and most likely involved the cell membrane

  8. Oxygen sensitization of mammalian cells under different irradiation conditions

    International Nuclear Information System (INIS)

    Ling, C.C.; Michaels, H.B.; Gerweck, L.E.; Epp, E.R.; Peterson, E.C.

    1981-01-01

    The oxygen dependence of the radiosensitivity of cultured CHO cells was examined in detail with particular attention paid to avoiding possible artifacts due to radiolytic oxygen depletion. Two methods of gas equilibration and irradiation were used. In the first approach, cells were irradiated with 50-kVp X rays in a thin-layer geometry which offered maximum interchange between the cells and the surrounding gas. The second technique employed 280-kVp X irradiation of cells under full-medium conditions with mechanical agitation to minimize the effect of radiochemical oxygen consumption by promoting rapid oxygen replenishment. With these techniques oxygen radiosensitization was clearly resolved at an oxygen concentration of 0.03% in the gas phase. The oxygen K curves measured by these two methods were similar in shape over a wide range of oxygen concentration

  9. Autoradiographic studies on the cell kinetics after the whole body X-irradiation. 2. Regularities of the post-irradiation death of differentiating and proliferating cells of the rat brain subependimal zone

    International Nuclear Information System (INIS)

    Gracheva, N.D.

    1982-01-01

    A wave-like character of death of proliferating and differentiating (D) cells is shown autoradiographically using 3 H-thymidine introduced 60-80 min before the whole body X-ray irradiation in doses of 50, 150 or 300 R on subependymal cells of rat brain. Lethally damaged cells irradiated in G 2 and S-phases, resulted in 4 peaks of death in mitosis by following the first postradiational mitotic cycle (MC). Lethally damaged cells irradiated in G 1 -phase lost ability for DNA synthesis as cells irradiated in a dose of 300 R did not include additionally introduced (3 hrs before death) 14 C-thymidine from 12 to 17 hrs after 3 H-thymidine injection. However, in the first 4 hrs after irradiation there were no cells irradiated in G 1 -phase among dead ones, as indirec showed the calculations of data obtained tly/ while studying Pliss lymphosarcoma. A supposition is made that the death of cells irradiated in G 1 -phase is attributed to mitotic phase of the first MC after irradiation. Waves of death of lethally damaged D-cells repeated the peaks of death and corresponded to the mitotic peaks of proliferating cells, which permitted to presuppose the presence of ''short cycle'' (SC) in D-cells, which have the rhythm similar to MC and their death has been attributed to the final SC phase, which corresponds to MC mitotic phase in time. According to the peaks of cell death position of one hour block independent of dose in six MC(SC) points is determined. The cells have experienced the block in the point of MC(SC) in subphase of which they were caught by irradiation. Dose effect is manifested in the number of dead cells

  10. 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

  11. X-ray microbeam stand-alone facility for cultured cells irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Bożek, Sebastian, E-mail: sebastian.bozek@yahoo.com [Jagiellonian University Medical College, Department of Pharmaceutical Biophysics, Krakow (Poland); Bielecki, Jakub; Wiecheć, Anna; Lekki, Janusz; Stachura, Zbigniew; Pogoda, Katarzyna; Lipiec, Ewelina; Tkocz, Konrad; Kwiatek, Wojciech M. [Institute of Nuclear Physics Polish Academy of Sciences, PL-31342 Krakow (Poland)

    2017-03-01

    Highlights: • An X-ray microbeam line for irradiation of living cultured cells was constructed. • A step by step explanation of working principles with engineering details, procedures and calculations is presented. • A model of beam and cell interaction is presented. • A method of uniform irradiation of living cells with an exact dose per a cell is presented. • Results of preliminary experiments are presented. - Abstract: The article describes an X-ray microbeam standalone facility dedicated for irradiation of living cultured cells. The article can serve as an advice for such facilities construction, as it begins from engineering details, through mathematical modeling and experimental procedures, ending up with preliminary experimental results and conclusions. The presented system consists of an open type X-ray tube with microfocusing down to about 2 μm, an X-ray focusing system with optical elements arranged in the nested Kirckpatrick-Baez (or Montel) geometry, a sample stand and an optical microscope with a scientific digital CCD camera. For the beam visualisation an X-ray sensitive CCD camera and a spectral detector are used, as well as a scintillator screen combined with the microscope. A method of precise one by one irradiation of previously chosen cells is presented, as well as a fast method of uniform irradiation of a chosen sample area. Mathematical models of beam and cell with calculations of kerma and dose are presented. The experiments on dose-effect relationship, kinetics of DNA double strand breaks repair, as well as micronuclei observation were performed on PC-3 (Prostate Cancer) cultured cells. The cells were seeded and irradiated on Mylar foil, which covered a hole drilled in the Petri dish. DNA lesions were visualised with γ-H2AX marker combined with Alexa Fluor 488 fluorescent dye.

  12. DNA repair capacity and rate of excision repair in UV-irradiated mammalian cells

    International Nuclear Information System (INIS)

    Inoue, Masao; Takebe, Hiraku.

    1978-01-01

    Repair capacities of five mammalian cell strains were measured by colony-forming ability, HCR of UV-irradiated virus, UDS, pyrimidine dimer excision, and semi-conservative DNA replication. Colony-forming ability of UV-irradiated cells was high for human amnion FL cells and mouse L cells, slightly low for African green monkey CV-1 cells, and extremely low for xeroderma pigmentosum cells. HCR of UV-irradiated Herpes simplex virus was high in CV-1 cells, FL and normal human fibroblast cells, low in both XP and L cells. The amount of UDS was high in FL and normal human fibroblast cells, considerably low in CV-1 cells, and essentially no UDS was observed in XP cells. Rate of UDS after UV-irradiation was slower for CV-1 cells than FL and human fibroblast cells. Rate of the excision of thymine-containing dimers from the acid-insoluble fraction during post-irradiation incubation of the cells was rapid in FL and normal human cells and slow in CV-1 cells, and no excision took place in XP cells. Semi-conservative DNA synthesis was reduced after UV-irradiation in all cell lines, but subsequently recovered in FL, normal human and CV-1 cells. The onset of recovery was 4 h after UV-irradiation for FL and normal human cells, but about 6 h for CV-1 cells. The apparent intermediate repair of CV-1 cells except for HCR may be related to the slow rate of excision repair. ''Patch and cut'' model is more favorable than ''cut and patch'' model to elucidate these results. (auth.)

  13. Proton irradiation effects of amorphous silicon solar cell for solar power satellite

    Energy Technology Data Exchange (ETDEWEB)

    Morita, Yousuke; Oshima, Takeshi [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment; Sasaki, Susumu; Kuroda, Hideo; Ushirokawa, Akio

    1997-03-01

    Flexible amorphous silicon(fa-Si) solar cell module, a thin film type, is regarded as a realistic power generator for solar power satellite. The radiation resistance of fa-Si cells was investigated by the irradiations of 3,4 and 10 MeV protons. The hydrogen gas treatment of the irradiated fa-Si cells was also studied. The fa-Si cell shows high radiation resistance for proton irradiations, compared with a crystalline silicon solar cell. (author)

  14. Mechanisms of taste bud cell loss after head and neck irradiation

    Science.gov (United States)

    Nguyen, Ha M.; Reyland, Mary E.; Barlow, Linda A.

    2012-01-01

    Taste loss in human patients following radiotherapy for head and neck cancer is a common and significant problem, but the cellular mechanisms underlying this loss are not understood. Taste stimuli are transduced by receptor cells within taste buds, and like epidermal cells, taste cells are regularly replaced throughout adult life. This renewal relies on a progenitor cells adjacent to taste buds, which continually supply new cells to each bud. Here we treated adult mice with a single 8 Gy dose of X-ray irradiation to the head and neck, and analyzed taste epithelium at 1–21 days post-irradiation (dpi). We found irradiation targets the taste progenitor cells, which undergo cell cycle arrest (1–3 dpi) and apoptosis (within 1 dpi). Taste progenitors resume proliferation at 5–7 dpi, with the proportion of cells in S and M phase exceeding control levels at 5–6 and 6 dpi, respectively, suggesting that proliferation is accelerated and/or synchronized following radiation damage. Using BrdU birthdating to identify newborn cells, we found that the decreased proliferation following irradiation reduces the influx of cells at 1–2 dpi, while the robust proliferation detected at 6 dpi accelerates entry of new cells into taste buds. By contrast, the number of differentiated taste cells was not significantly reduced until 7 dpi. These data suggest a model where continued natural taste cell death, paired with temporary interruption of cell replacement underlies taste loss after irradiation. PMID:22399770

  15. ATM phosphorylation in HepG2 cells following continuous low dose-rate irradiation

    International Nuclear Information System (INIS)

    Mei Quelin; Du Duanming; Chen Zaizhong; Liu Pengcheng; Yang Jianyong; Li Yanhao

    2008-01-01

    Objective: To investigate the change of ATM phosphorylation in HepG2 cells following a continuous low dose-rate irradiation. Methods: Cells were persistently exposed to low dose-rate (8.28 cGy/h) irradiation. Indirect immunofluorescence and Western blot were used to detect the expression of ATM phosphorylated proteins. Colony forming assay was used to observe the effect of a low dose-rate irradiation on HepG2 cell survival. Results: After 30 min of low dose-rate irradiation, the phosphorylation of ATM occurred. After 6 h persistent irradiation, the expression of ATM phosphorylated protein reached the peak value, then gradually decreased. After ATM phosphorylation was inhibited with Wortmannin, the surviving fraction of HepG2 cells was lower than that of the irradiation alone group at each time point (P<0.05). Conclusions: Continuous low dose-rate irradiation attenuated ATM phosphorylation, suggesting that continuous low dose-rate irradiation has a potential effect for increasing the radiosensitivity of HepG2 cells. (authors)

  16. Irradiation specifically sensitises solid tumour cell lines to TRAIL mediated apoptosis

    International Nuclear Information System (INIS)

    Marini, Patrizia; Schmid, Angelika; Jendrossek, Verena; Faltin, Heidrun; Daniel, Peter T; Budach, Wilfried; Belka, Claus

    2005-01-01

    TRAIL (tumor necrosis factor related apoptosis inducing ligand) is an apoptosis inducing ligand with high specificity for malignant cell systems. Combined treatment modalities using TRAIL and cytotoxic drugs revealed highly additive effects in different tumour cell lines. Little is known about the efficacy and underlying mechanistic effects of a combined therapy using TRAIL and ionising radiation in solid tumour cell systems. Additionally, little is known about the effect of TRAIL combined with radiation on normal tissues. Tumour cell systems derived from breast- (MDA MB231), lung- (NCI H460) colorectal- (Colo 205, HCT-15) and head and neck cancer (FaDu, SCC-4) were treated with a combination of TRAIL and irradiation using two different time schedules. Normal tissue cultures from breast, prostate, renal and bronchial epithelia, small muscle cells, endothelial cells, hepatocytes and fibroblasts were tested accordingly. Apoptosis was determined by fluorescence microscopy and western blot determination of PARP processing. Upregulation of death receptors was quantified by flow cytometry. The combined treatment of TRAIL with irradiation strongly increased apoptosis induction in all treated tumour cell lines compared to treatment with TRAIL or irradiation alone. The synergistic effect was most prominent after sequential application of TRAIL after irradiation. Upregulation of TRAIL receptor DR5 after irradiation was observed in four of six tumour cell lines but did not correlate to tumour cell sensitisation to TRAIL. TRAIL did not show toxicity in normal tissue cell systems. In addition, pre-irradiation did not sensitise all nine tested human normal tissue cell cultures to TRAIL. Based on the in vitro data, TRAIL represents a very promising candidate for combination with radiotherapy. Sequential application of ionising radiation followed by TRAIL is associated with an synergistic induction of cell death in a large panel of solid tumour cell lines. However, TRAIL receptor

  17. Irradiated murine fibroblasts as feeder layer used in human cell culture

    International Nuclear Information System (INIS)

    Almeida, Tiago L.; Klingbeil, Fatima G.; Yoshito, Daniele; Caproni, Priscila; Mathor, Monica B.; Herson, Marisa R.

    2007-01-01

    In 1975, Rheinwald and Green published an in vitro model for keratinocyte cell cultures in which the use of murine fibroblasts, as a feeder layer was introduced. These cells are modified fibroblasts, which presence render keratinocyte cells to remain proliferative for longer periods of time. This optimization of culture outputs has allowed for several clinical applications of confluent keratinocyte cultures as skin substitutes or wound dressings in situations such as post burn extensive skin loss, loss of oral mucosa, and other skin disorders. Nevertheless, proliferation of fibroblast in co-culture with keratinocytes must be controlled by anti-proliferative measures such as irradiation; at the same time, keratinocytes require specific nutrients in the culture medium, which may interfere with the fibroblast feeder layer viability. Therefore, the thorough understanding of the impact of different issues such as culture media composition, irradiation dose and pre-plating storage conditions of irradiated fibroblast to be used as feeder layer in these co-culture systems is important. In this work, changes as far as viability and proliferative rates of irradiated fibroblasts in culture were evaluated in relation to the type of culture medium used, dose of gamma radiation exposure, storage and timing of cell plating post irradiation. Results indicate that the type of culture medium used and time-lag between irradiation, refrigeration and plating of irradiated cells do not have significant impact in culture outcomes. However, the dose of gamma radiation administered to the cells may influence the final quality of these cells if to be used as a feeder layer. (author)

  18. 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

  19. In vitro proliferative capacity of vascular cells irradiated in vivo

    International Nuclear Information System (INIS)

    Fischer-Dzoga, K.; Dimitrievich, G.S.; Griem, M.L.

    1985-01-01

    Explants were prepared from rabbit vascular aortic layers and irradiated with x-ray doses ranging from 100 cGy-5 cGy. This resulted in a 50% reduction in number of outgrowing cells with doses of 100-125 gy. Doses of 250, 500 and 750 gy resulted in a reduction of 70, 90, and 95% respectively. However, when the rabbit was irradiated in vivo to a narrow mediastinal port immediately before the explantation of vascular tissue, the number of outgrowing cells was comparable to that of the irradiated control for doses up to 250 cGy, while doses of 500 and 750 cGy reduced outgrowth by 60 and 93% respectively. To test for in situ repair, the time interval between irradiation and explantation was prolonged from 1-4 hours in one hour increments. The results were scored as average number of cells/explant and average number of cells/growing culture

  20. Effect of in vitro irradiation and cell cycle-inhibitory drugs on the spontaneous human IgE synthesis in vitro

    International Nuclear Information System (INIS)

    Del Prete, G.F.; Vercelli, D.; Tiri, A.; Maggi, E.; Rossi, O.; Romagnani, S.; Ricci, M.

    1987-01-01

    The in vitro effects of radiation, diterpine forskolin (FK), and hydrocortisone (HC) on the in vitro spontaneous IgE synthesis by peripheral blood B-lymphocytes from atopic patients were investigated. Without affecting cell viability, in vitro irradiation inhibited in a dose-dependent fashion de novo IgE synthesis in vitro by B cells from all patients examined with a mean 40% reduction of in vitro IgE product after treatment with 100 rads. In contrast, the in vitro IgE production by the U266 myeloma cell line was unaffected, even by irradiation with 1600 rads. The addition to B cell cultures from atopic patients of FK consistently resulted in a dose-dependent inhibition of the spontaneous IgE production in vitro. The addition to cultures of 10(-5) and 10(-6) molar concentrations of HC was also usually inhibitory, whereas lower HC concentrations were uneffective or even enhanced the spontaneous in vitro IgE synthesis. When 10(-6) molar concentrations of both HC and FK were combined in culture, a summation inhibitory effect on the spontaneous IgE synthesis was observed. In contrast, neither FK nor HC had inhibitory effect on the in vitro spontaneous IgE synthesis by the U266 myeloma cell line. The spontaneous in vitro IgE synthesis by B cells from patients with Hodgkin's disease, demonstrating high levels of serum IgE, was strongly reduced or virtually abolished after patients underwent total nodal irradiation to prevent the spread of the disease. In addition, the in vitro spontaneous IgE synthesis by B cells from atopic patients was markedly decreased or abolished by in vivo administration of betamethasone

  1. Repair and mutagenesis of herpes simplex virus in UV-irradiated monkey cells

    International Nuclear Information System (INIS)

    Lytle, C.D.; Goddard, J.G.; Lin, C.H.

    1980-01-01

    Mutagenic repair in mammalian cells was investigated by determining the mutagenesis of UV-irradiated or unirradiated herpes simplex virus in UV-irradiated CV-1 monkey kidney cells. These results were compared with the results for UV-enhanced virus reactivation (UVER) in the same experimental situation. High and low multiplicities of infection were used to determine the effects of multiplicity reactivation (MR). UVER and MR were readily demonstrable and were approximately equal in amount in an infectious center assay. For this study, a forward-mutation assay was developed to detect virus mutants resistant to iododeoxycytidine (ICdR), probably an indication of the mutant virus being defective at its thymidine kinase locus. ICdR-resistant mutants did not have a growth advantage over wild-type virus in irradiated or unirradiated cells. Thus, higher fractions of mutant virus indicated greater mutagenesis during virus repair and/or replication. The data showed that: (1) unirradiated virus was mutated in unirradiated cells, providing a background level of mutagenesis; (2) unirradiated virus was mutated about 40% more in irradiated cells, indicating that virus replication (DNA synthesis) became more mutagenic as a result of cell irradiation; (3) irradiated virus was mutated much more (about 6-fold) than unirradiated virus, even in unirradiated cells; (4) cell irradiation did not change the mutagenesis of irradiated virus except at high multiplicity of infection. High multiplicity of infection did not demonstrate UVER or MR alone to be either error-free or error-prone. When the two processes were present simultaneously, they were mutagenic. (orig.)

  2. Mutagenic effect of cyclophosphan on bone marrow cells of irradiated rats

    International Nuclear Information System (INIS)

    Barkan, R.S.; Yakovleva, T.K.

    1979-01-01

    The frequency of chromosome aberrations in bone marrow cells of male rats was studied 24 hours after the intraperitoneal injection of cyclophosphane (25 mg/kg weight). Cyclophosphane (CP) was injected to animals that had been earlier (15 days before, 1, 3, 4, 6 and 9 months earlier) exposed to X-ray and γ-irradiation at the dose of 400 rad. It has been shown that the preliminary irradiation of animals results in a higher mutagenic CP effect as against its effect for non irradiated rats. The effect was recorded during four months following the acute single x-irradiation (dose rate of 70 rad/min) and within one month following chronic γ-irradiation (dose rate of 100 rad/day). At later periods, the above effect fully disappeared. Chronic irradiation was less effective with regard to the subsequent mutagenic CP action than the acute irradiation. In most experiments with acute irradiation an increase in mutagenic CP efficiency revealed itself both in an increase in the frequency of cells with chromosome aberrations and in the cell damage rate. The possible mechanisms of the effect of preliminary irradiation on the subsequent mutagenic effect of chemical compounds are discussed

  3. Dose verification by OSLDs in the irradiation of cell cultures

    International Nuclear Information System (INIS)

    Meca C, E. A.; Bourel, V.; Notcovich, C.; Duran, H.

    2015-10-01

    The determination of value of irradiation dose presents difficulties when targets are irradiated located in regions where electronic equilibrium of charged particle is not reached, as in the case of irradiation -in vitro- of cell lines monolayer-cultured, in culture dishes or flasks covered with culture medium. The present study aimed to implement a methodology for dose verification in irradiation of cells in culture media by optically stimulated luminescence dosimetry (OSLD). For the determination of the absorbed dose in terms of cell proliferation OSL dosimeters of aluminum oxide doped with carbon (Al 2 O 3 :C) were used, which were calibrated to the irradiation conditions of culture medium and at doses that ranged from 0.1 to 15 Gy obtained with a linear accelerator of 6 MV photons. Intercomparison measurements were performed with an ionization chamber of 6 cm 3 . Different geometries were evaluated by varying the thicknesses of solid water, air and cell culture medium. The results showed deviations below 2.2% when compared with the obtained doses of OSLDs and planning system used. Also deviations were observed below 3.4% by eccentric points of the irradiation plane, finding homogeneous dose distribution. Uncertainty in the readings was less than 2%. The proposed methodology contributes a contribution in the dose verification in this type of irradiations, eliminating from the calculation uncertainties, potential errors in settling irradiation or possible equipment failure with which is radiating. It also provides certainty about the survival curves to be plotted with the experimental data. (Author)

  4. Migration of bone marrow cells to the thymus in sublethally irradiated mice

    International Nuclear Information System (INIS)

    Varlet, Andree; Lenaerts, Patrick; Houben-Defresne, M.P.; Boniver, Jacques

    1982-01-01

    In sublethally irradiated mice, thymus repopulation is due first to the proliferation of surviving thymocytes followed by the multiplication of bone marrow derived prothymocytes. The migration of bone marrow cells to the thymus after a single sublethal whole-body X irradiation was studied by using fluorescein isothiocyanate as a cell marker. Irradiation increases the permissiveness of the thymus to the immigration of bone marrow cells. Furthermore, the post-Rx regenerating bone marrow cells exhibit migration capacities greater than the normal ones. The radiation induced changes in the bone marrow thymus interaction might play an important role in thymus regeneration after sublethal irradiation [fr

  5. Reduction of irradiated tumor cells viability under effect of hyperglycemia

    International Nuclear Information System (INIS)

    Meshcherikova, V.V.; Voloshina, E.A.

    1983-01-01

    On Ehrlich carcinoma cells adapted to growth in vivo and in vitro, cellular mechanisms of short-term hyperglycemia effect have been studied. It has been found that SH by itself leads to the loss of viability of a part of cells of ELD solid tumors manifesting during the first 24 hours upon irradiation according to the interphase death type. Tumor cell radiation injuries arising under the effect of irradiation, usually non realized up to the first division, under SH conditions potentiate its injury effect. The phenomena observed explain partially selective injury of tumoral cells in the course of irradiation under SH conditions which testifies to the prospects of its use in clinics

  6. Action of caffeine on the survival of x-irradiated cells

    International Nuclear Information System (INIS)

    Busse, P.M.

    1978-01-01

    Post-irradiation treatment of HeLa S3 cells with 1 mM caffeine results in a marked diminution of the surviving fraction as scored by colony formation. The decrease is dose-dependent; the effect of a 24-h post-irradiation treatment of a non-synchronous population with caffeine is to change the terminal slope of the survival curve and its intercept. Do is reduced from 130 to 60 rad; the extrapolation number is increased about twofold. The amount of post-irradiation killing is maximal if cells are exposed to caffeine at a concentration of at least 1 mM for 8 hours; less than 10% of unirradiated cells are killed under these conditions. Dose-response curves were also obtained for synchronous cells at various phases of the cell cycle. Similar results were obtained at all cell ages, but the magnitude of the effect is age-dependent. This age dependence was further explored in experiments in which mitotically collected cells were exposed to 300 or 500 rad doses at 2-hour intervals throughout the cell cycle. Treatment with caffeine for 24 hours after irradiation enhances the killing of cells late in the cycle more than in G 1 . The sensitivities of two other cell lines, CHO and EMT6, also were examined; both are substantially less sensitive to caffeine. The smaller cell-cycle dependence of CHO cells is qualitatively the same as that of HeLa cells

  7. Effects of irradiance and prey deprivation on growth, cell carbon and photosynthetic activity of the freshwater kleptoplastidic dinoflagellate Nusuttodinium (= Gymnodinium aeruginosum (Dinophyceae.

    Directory of Open Access Journals (Sweden)

    Kirstine Drumm

    Full Text Available The freshwater dinoflagellate Nusuttodinium aeruginosum lacks permanent chloroplasts. Rather it sequesters chloroplasts as well as other cell organelles, like mitochondria and nuclei, from ingested cryptophyte prey. In the present study, growth rates, cell production and photosynthesis were measured at seven irradiances, ranging from 10 to 140 μmol photons m-2s-1, when fed the cryptophyte Chroomonas sp. Growth rates were positively influenced by irradiance and increased from 0.025 d-1 at 10 μmol photons m-2s-1 to maximum growth rates of ~0.3 d-1 at irradiances ≥ 40 μmol photons m-2s-1. Similarly, photosynthesis ranged from 1.84 to 36.9 pg C cell-1 h-1 at 10 and 140 μmol photons m-2s-1, respectively. The highest rates of photosynthesis in N. aeruginosum only corresponded to ~25% of its own cell carbon content and estimated biomass production. The measured rates of photosynthesis could not explain the observed growth rates at high irradiances. Cultures of N. aeruginosum subjected to prey starvation were able to survive for at least 27 days in the light. The sequestered chloroplasts maintained their photosynthetic activity during the entire period of starvation, during which the population underwent 4 cell divisions. This indicates that N. aeruginosum has some control of the chloroplasts, which may be able to replicate. In conclusion, N. aeruginosum seems to be in an early stage of chloroplast acquisition with some control of its ingested chloroplasts.

  8. 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

  9. Real-time observation of irradiated Hela-cell Modified by Fluorescent ubiquitination-based Cell Cycle Indicator Using Synchrotron X-Ray Microbeam

    International Nuclear Information System (INIS)

    Narita, A.; Noguchi, M.; Kaminaga, K.; Yokoya, A.; Kobayashi, K.; Usami, N.; Fujii, K.

    2015-01-01

    Fluorescent ubiquitination-based cell-cycle indicator (FUCCI) human cancer (HeLa) cells (red indicates G1; green, S/G2) were exposed to a synchrotron X-ray microbeam. Cells in either G1 or S/G2 were irradiated selectively according to their colour in the same microscopic field. Time-lapse micrographs of the irradiated cells were acquired for 24 h after irradiation. For fluorescent immunostaining, phosphorylated histone proteins (γ-H2AX) indicated the induction of DNA double-strand breaks. The cell cycle was arrested by irradiation at S/G2. In contrast, cells irradiated at G1 progressed to S/G2. The foci were induced in cells irradiated at both G1 and S/G2, suggesting that the G1-S (or S) checkpoint pathway does not function in HeLa cells due to the fact that the cells are functionally p53 deficient, even though X-ray microbeam irradiation significantly induces double-strand breaks. These results demonstrate that single FUCCI cell exposure and live cell imaging are powerful methods for studying the effects of radiation on the cell cycle. (authors)

  10. S-phase cell distribution in the small intestine irradiated at different times of the day. I. Acute irradiation injury

    Energy Technology Data Exchange (ETDEWEB)

    Becciolini, A; Balzi, M; Cremonini, D; Fabbrica, D [Florence Univ. (Italy). Ist. di Radiologia

    1983-01-01

    The S-phase cell distribution has been analysed to evaluate the behaviour of proliferative cells in the intestinal epithelium after irradiation at different times of the day. A marked reduction of S cell frequency was observed at early intervals after abdominal irradiation; this reduction was particularly evident in the lower half of the crypts. At subsequent intervals a progressive extension of the proliferative compartment, with labelled cells also at the top of the crypt, was present. The irradiated groups generally showed a homogeneous behaviour even if a more marked reduction in S-phase cells was observed in group C. The invertase activity, a brush border enzyme synthetized during the differentiation process, presented a different behaviour at the early intervals in the irradiated groups. When the extension of the proliferative compartment occurred the invertase activity reached values close to zero. The modifications in brush border enzymes and in S-phase cell distribution, at early killing times, led to the hypothesis of an early differentiation.

  11. Leydig cell damage after testicular irradiation for lymphoblastic leukemia

    International Nuclear Information System (INIS)

    Shalet, S.M.; Horner, A.; Ahmed, S.R.; Morris-Jones, P.H.

    1985-01-01

    The effect of testicular irradiation on Leydig cell function has been studied in a group of boys irradiated between 1 and 5 years earlier for a testicular relapse of acute lymphoblastic leukemia. Six of the seven boys irradiated during prepubertal life had an absent testosterone response to HCG stimulation. Two of the four boys irradiated during puberty had an appropriate basal testosterone level, but the testosterone response to HCG stimulation was subnormal in three of the four. Abnormalities in gonadotropin secretion consistent with testicular damage were noted in nine of the 11 boys. Evidence of severe Leydig cell damage was present irrespective of whether the boys were studied within 1 year or between 3 and 5 years after irradiation, suggesting that recovery is unlikely. Androgen replacement therapy has been started in four boys and will be required by the majority of the remainder to undergo normal pubertal development

  12. Deformation behavior of cell spring of an irradiated spacer grid

    International Nuclear Information System (INIS)

    Jin, Y. G.; Baek, S. J.; Ryu, W. S.; Kim, G. S.; Yoo, B. O.; Kim, D. S.; Ahn, S. B.; Chun, Y. B.; Choo, Y. S.

    2012-01-01

    Mechanical properties of a space grid of a fuel assembly are of great importance for fuel operation reliability in extended fuel burnup and duration of fuel life. The spacer grid with inner and outer straps has cell spring and dimples, which are in contact with the fuel rod. The spacer grids supporting the fuel rods absorb vibration impacts due to the reactor coolant flow and also grid spring force is decreasing under irradiation. This reduction of contact force might cause the grid to rod fretting wear. The fretting failure of the fuel rod is one of the significant issues recently in the nuclear industry from an economical as well as a safety concern. Thus, it is important to understand the characteristics of cell spring behavior for an irradiated spacer grid. In the present study, the stiffness test and dimensional measurement of cell springs were conducted to investigate the deformation behavior of cell springs of an irradiated spacer grid in a hot cell at IMEF (irradiated materials examination facility) of KAERI

  13. Overview of Radiosensitivity of Human Tumor Cells to Low-Dose-Rate Irradiation

    International Nuclear Information System (INIS)

    Williams, Jerry R.; Zhang Yonggang; Zhou Haoming; Gridley, Daila S.; Koch, Cameron J.; Slater, James M.; Little, John B.

    2008-01-01

    Purpose: We compared clonogenic survival in 27 human tumor cell lines that vary in genotype after low-dose-rate (LDR) or high-dose rate (HDR) irradiation. We measured susceptibility to LDR-induced redistribution in the cell cycle in eight of these cell lines. Methods and Materials: We measured clonogenic survival after up to 96 hours of LDR (0.25 Gy/h) irradiation. We compared these with clonogenic survival after HDR irradiation (50 Gy/h). Using flow cytometry, we measured LDR-induced redistribution as a function of time during LDR irradiation in eight of these cell lines. Results: Coefficients that describe clonogenic survival after both LDR and HDR irradiation segregate into four radiosensitivity groups that associate with cell genotype: mutant (mut)ATM, wild-type TP53, mutTP53, and an unidentified gene in radioresistant glioma cells. The LDR and HDR radiosensitivity correlates at lower doses (∼2 Gy HDR, ∼6 Gy LDR), but not at higher doses (HDR > 4 Gy; LDR > 6 Gy). The rate of LDR-induced loss of clonogenic survival changes at approximately 24 hours; wild-type TP53 cells become more resistant and mutTP53 cells become more sensitive. Redistribution induced by LDR irradiation also changes at approximately 24 hours. Conclusions: Radiosensitivity of human tumor cells to both LDR and HDR irradiation is genotype dependent. Analysis of coefficients that describe cellular radiosensitivity segregates 27 cell lines into four statistically distinct groups, each associating with specific genotypes. Changes in cellular radiosensitivity and redistribution in the cell cycle are strongly time dependent. Our data establish a genotype-dependent time-dependent model that predicts clonogenic survival, explains the inverse dose-rate effect, and suggests possible clinical applications

  14. Delayed cell death, giant cell formation and chromosome instability induced by X-irradiation in human embryo cells

    International Nuclear Information System (INIS)

    Roy, K.; Kodama, Seiji; Suzuki, Keiji; Watanabe, Masami

    1999-01-01

    We studied X-ray-induced delayed cell death, delayed giant cell formation and delayed chromosome aberrations in normal human embryo cells to explore the relationship between initial radiation damage and delayed effect appeared at 14 to 55 population doubling numbers (PDNs) after X-irradiation. The delayed effect was induced in the progeny of X-ray survivors in a dose-dependent manner and recovered with increasing PDNs after X-irradiation. Delayed plating for 24 h post-irradiation reduced both acute and delayed lethal damage, suggesting that potentially lethal damage repair (PLDR) can be effective for relieving the delayed cell death. The chromosome analysis revealed that most of the dicentrics (more than 90%) observed in the progeny of X-ray survivors were not accompanied with fragments, in contrast with those observed in the first mitosis after X-irradiation. The present results indicate that the potentiality of genetic instability is determined during the repair process of initial radiation damage and suggest that the mechanism for formation of delayed chromosome aberrations by radiation might be different from that of direct radiation-induced chromosome aberrations. (author)

  15. Relationship between α/β and radiosensitivity and biologic effect of fractional irradiation of tumor cells

    International Nuclear Information System (INIS)

    Guo Chuanling; Chinese Academy of Sciences, Beijing; Wang Jufang; Jin Xiaodong; Li Wenjian

    2006-01-01

    Five kinds of malignant human tumor cells, i.e. SMMC-7721, HeLa, A549, HT29 and PC3 cell lines, were irradiated by 60 Co γ-rays to 1-6 Gy in a single irradiation or two irradiations of half dose. The radiosensitivity was compared with the dose-survival curves and D 50 and D 10 values. Differences in the D 50 and D 10 between the single and fractional irradiation groups showed the effect of fractional irradiation. Except for PC3 cells, all the cell lines showed obvious relationship between radiosensitivity and biologic effect of fractional irradiation and the α/β value. A cell line with bigger α/β was more radiation sensitive, with less obvious effect of fractional irradiation. The results indicate that there were obvious differences in radiosensitivity, repair ability and biologic effect of fractional irradiation between tumor cells from different tissues. To some tumor cell lines, the relationship between radiosensitivity, biologic effect of fractional irradiation and repair ability was attested. The α/β value of single irradiation can be regarded as a parameter to investigate the radiosensitivity and biologic effect of fractional irradiation of tumor cells. (authors)

  16. Subclinical hypothyroidism in children and adolescents after hematopoietic stem cells transplantation without irradiation

    Directory of Open Access Journals (Sweden)

    Milenković Tatjana

    2014-01-01

    Full Text Available Background/Aim. Although total body irradiation (TBI was considered to be the primary cause of thyroid dysfunction following hematopoietic stem cells transplantation (HSCT, a significant prevalence of subclinical hypothyroidism after HSCT with chemotherapy-only conditioning regimens has been observed in several studies. The aim of this study was to assess changes in thyroid stimulating hormone (TSH levels in children after HSCT, without the use of irradiation at any time in the course of the treatment. Methods. Our cohort consisted of 41 children and adolescents who underwent autologous or allogeneic HSCT and were available for follow-up for at least one year after transplantation. Irradiation was not performed in any of the subjects, neither during pretransplatation therapy, nor during conditioning. The median duration of follow-up was 2.9 years. The indications for HSCT were hematologic malignancy (41.5%, solid malignant tumor (34.1%, and other disorders (24.4%. The thyroid status of all the subjects was assessed prior to HSCT and after follow-up period. Results. Thyroid dysfunction after HSCT was present in 27 (65.8% subjects. Subclinical hypothyroidism was the most common abnormality, presenting in 23 (56.1% patients, primary hypothyroidism was present in one (2.4% patient, while 3 (7.3% subjects had low free T4 with normal TSH values. Significantly (p < 0.01 higher elevations in TSH levels were present in the patients who received chemotherapy for the underlying disease prior to HSCT. Conclusion. Our findings emphasize the need for long-term monitoring of thyroid function following HSCT, regardless of whether or not irradiation was used.

  17. X-irradiation-induced nuclear lesions in cultured mammaliam cells: an ultrastructural analysis

    International Nuclear Information System (INIS)

    Barham, S.S.; Walters, R.A.

    1978-01-01

    Electron-dense chromatin aggregates, hereafter referred to as lesions, have been characterized morphologically within interphase nuclei of Chinese hamster cells (line CHO) after a single acute exposure to 400, 800, 1200, or 2000 rad of x irradiation. At all doses studied, lesions were observed only after termination of radiation-induced division delay. Cell profiles were scored by electron microscopy for the presence or absence of nuclear lesions at various times after irradiation. The mitotic fraction from each irradiated population was also scored for each sample by light and electron microscopy. From these data and from simultaneous cell-density counts for each sample, it is apparent that postirradiation cell division is a prerequisite to formation of interphase nuclear lesions. Irradiated cell populations blocked in mitosis by Colcemid beyond the normal period of postirradiation division-delay failed to display nuclear lesions until after Colcemid was removed and cell division was completed. Enzyme digestions of isolated nuclei from irradiated cells with DNase I, RNase A, and Pronase suggest that the nuclear lesions are comprised primarily of chromatin. Nucleolar lesions, as well as various aberrant morphological forms of nucleoli, were also observed in cell populations after the onset of postirradiation cell division during the first 72 hr following exposure to irradiation. Delayed radiation-induced ultrastructural alterations of the nucleus included the formation of cytoplasmic invaginations into the nuclear space and inclusions of membranes within nuclei

  18. Inhibition of EGFR nuclear shuttling decreases irradiation resistance in HeLa cells.

    Science.gov (United States)

    Wei, Hong; Zhu, Zijie; Lu, Longtao

    2017-01-01

    Cervical cancer is a leading cause of mortality in women worldwide. The resistance to irradiation at the advanced stage is the main reason for the poor prognosis and high mortality. This work aims to elucidate the molecular mechanism underlying the radio-resistance. In this study, we determined the pEGFR-T654 and pDNA-PK-T2609 expression level changes in irradiated HeLa cells treated with T654 peptide, a nuclear localization signal (NLS) inhibitor, to inhibit EGFR nuclear transport. Cell viability, cell cycle and migratory capacity were analyzed. Xenograft animal model was used to evaluate the effect of EGFR nuclear transport inhibition on the tumor growth in vivo. The enhanced translocation of nuclear EGFR in the irradiated HeLa cells correlated with the increasing level of pEGFR-T654 and pDNA-PK-T2609. Inhibition of EGFR nuclear translocation by NLS peptide inhibitor attenuated DNA damage repair in the irradiated HeLa cells, decreased cell viability and promoted cell death through arrest at G0 phase. NLS peptide inhibitor impaired the migratory capacity of irradiated HeLa cells, and negatively affected tumorigenesis in xenograft mice. This work puts forward a potential molecular mechanism of the irradiation resistance in cervical cancer cells, providing a promising direction towards an efficient therapy of cervical cancer.

  19. An Effective Approach for Immunotherapy Using Irradiated Tumor Cells

    International Nuclear Information System (INIS)

    Mostafa, D.M.B.

    2011-01-01

    This study has been aimed to investigate the effect of injection of Irradiated Ehrlich tumor cells alone or concurrent with immunomodulator in mice before and after challenge with viable Ehrlich tumor cells for enhancement of immune system. This study includes the estimation of survival, tumor size, lymphocyte count, LDH, MTT, granzyme B, and DNA fragmentation. In order to fulfill the target of this study, a total of 120 female swiss albino mice were used. They were divided into two classes vaccinated (injection of vaccine before challenge) and therapeutic class (injection of vaccine after challenge). Each class was divided into four groups, group (1) mice injected with viable Ehrlich tumor cells (G1), group (2) mice injected with irradiated tumor cells (G2), group (3) mice injected with immunomodulator (G3), and group (4) mice injected with irradiated tumor cells + immunomodulator (G4). Results obtained from this study demonstrated that, the lymphocyte count and granzyme B activity were increased in both the vaccinated and therapeutic classes compared with control group. LDH activity was decreased in all groups of vaccinated class and also in G2 and G4 groups of therapeutic class compared with control group. There was a significant increase in percent apoptosis of tumor cells cultured with spleenocytes of the groups of vaccinated class as compared with control group. Cellular DNA from Ehrlich tumor cell line cultured with spleenocytes of immunized groups was fragmented into discrete bands of approximate multiples of 200 bp. Revealing significant apoptosis in tumor cells due to vaccination. It is concluded that, vaccination with irradiated tumor cells is an effective approach in stimulation of immune system against viable tumor cells.

  20. Prognostic significance of nuclear factor of activated T-cells 5 expression in non-small cell lung cancer patients who underwent surgical resection.

    Science.gov (United States)

    Cho, Hyun Jin; Yun, Hwan-Jung; Yang, Hee Chul; Kim, Soo Jin; Kang, Shin Kwang; Che, Chengri; Lee, Sang Do; Kang, Min-Woong

    2018-06-01

    Nuclear factor of activated T-cells 5 (NFAT5) is known to be correlated with migration or invasion of tumor cells based on previous in vitro studies. The aim of this study was to analyze the relationship between NFAT5 expression and clinical prognosis in non-small cell lung cancer (NSCLC) patients who underwent surgical resection. A total of 92 NSCLC patients who underwent surgical resection were enrolled. The tissue microarray core was obtained from surgically resected tumor specimens. NFAT5 expression was evaluated by immunohistochemistry. Relationships of NFAT5 expression with disease recurrence, overall survival, and disease-free survival (DFS) were analyzed. The mean age of 92 patients was 63.7 y. The median follow-up duration was 63.3 mo. Fifty-one (55%) patients exhibited positive expression of NFAT5. Disease recurrence in the NFAT5-positive group was significantly (P = 0.022) higher than that in the NFAT5-negative group. NFAT5-positive expression (odds ratio: 2.632, 95% confidence interval: 1.071-6.465, P = 0.035) and pathologic N stage (N1-2 versus N0; odds ratio: 3.174, 95% confidence interval: 1.241-8.123, P = 0.016) were independent and significant risk factors for disease recurrence. DFS of the NFAT5-positive group was significantly worse than that of the NFAT5-negative group (89.7 versus 48.7 mo, P = 0.011). A multivariate analysis identified NFAT5 expression (P < 0.029) as a significant independent risk factor for DFS of patients with postoperative pathologic T and N stages (P < 0.001 and P = 0.017, respectively). NFAT5 expression is a useful prognostic biomarker for NSCLC patients who underwent surgical resection. Copyright © 2018 Elsevier Inc. All rights reserved.

  1. 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.

  2. Relapsing pattern of brain metastasis after brain irradiation in small cell lung cancer

    International Nuclear Information System (INIS)

    Murakami, Masao; Kuroda, Yasumasa; Okamoto, Yoshiaki; Kono, Koichi; Yoden, Eisaku; Mori, Takeki

    1997-01-01

    Many reports concerning radiation therapy for brain metastasis have been published, and which of the various methods urged by these reports provide optional control is still controversial. According to developing diagnosis of metastasis in CNS, therapeutic problems should be referred. We reviewed 67 patients with small cell lung cancer and brain metastasis who underwent brain irradiation (Ave. 47 Gy/5W), and all 15 patients with brain relapse after the irradiation. Relapsing patterns in this clinical setting were divided into local regrowth in the same lesions and re-metastasis (reseeding) in other regions, by reviewing follow up CT and MRI studies. Total survival among 15 patients with brain relapse and 52 without relapse was longer in the former cases than the later: 1-, and 2-year survival (47/19%, 13/8%) and MST (10.8/5.7 months), from the initial brain irradiation. The concerned significant factors limited in younger age, low value of LDH and improvement of NF. Of the 15 patients with brain relapse, 4 developed local regrowth and 11 did re-metastasis. The period of remission since brain irradiation were 172±94.4 and 393±281 days, respectively. Lower number of brain metastasis and lower value of LDH were shown in re-metastasis patients. At the time of brain relapse, 11 patients had recurrence of carcinomatous meningitis. 4 patients were treated with whole brain re-irradiation. All patients died of cancer, including 12 of relapsing CNS diseases and 3 of primary lesion and hepatic metastasis. Leukoencephalopathy developed in 2 patients. Survival since the brain relapse was 2 to 238 days without significant difference in cases of local regrowth and re-metastasis. According to our data on relapsing pattern of brain metastasis after conventional fractionated brain irradiation with an objective dose of 50 Gy, 75% of brain relapse were re-metastasis, we appreciate this irradiation for initial brain metastasis if limited to the brain. (author)

  3. In vitro infectivity of irradiated Plasmodium berghei sporozoites to cultured hepatoma cells

    International Nuclear Information System (INIS)

    Sigler, C.I.; Leland, P.; Hollingdale, M.R.

    1984-01-01

    The invasion of gamma-irradiated Plasmodium berghei sporozoites into cultured hepatoma cells and their transformation into trophozoites was similar to invasion and transformation of non-irradiated sporozoites. However, trophozoites from irradiated sporozoites did not further develop into schizonts, but persisted within the cells for up to 3 days. Sporozoite surface protective antigen was present in trophozoites from irradiated and non-irradiated sporozoites, suggesting that hepatocyte antigen processing may contribute to the induction of anti-malarial immunity

  4. 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).

  5. The effect of thymus cells on bone marrow transplants into sublethally irradiated mice

    International Nuclear Information System (INIS)

    Kruszewski, J.A.; Szcylik, C.; Wiktor-Jedrzejczak, W.

    1984-01-01

    Bone marrow cells formed similar numbers of 10-days spleen colonies in sublethally (6 Gy) irradiated C57B1/6 mice as in lethally (7.5 Gy) irradiated mice i.e. approximately 20 per 10 5 cells. Numbers of 10 day endogenous spleen colonies in sublethally irradiated mice (0.2 to 0.6 per spleen) did not differ significantly from the numbers in lethally irradiated mice. Yet, transplants of 10 7 coisogenic marrow cells into sublethally irradiated mice resulted in predominantly endogenous recovery of granulocyte system as evidenced by utilization of ''beige'' marker for transplanted cells. Nevertheless, transplanted cells engrafted into sublethally irradiated mice were present in their hemopoietic tissues throughout the observation period of 2 months never exceeding 5 to 10% of cells. Thymus cells stimulated endogenous and exogenous spleen colony formation as well as endogenous granulopoietic recovery. Additionally, they increased both the frequency and absolute numbers of graft-derived granulocytic cells in hemopoietic organs of transplanted mice. They failed, however, to essentially change the quantitative relationships between endogenous and exogenous hemopoietic recovery. These results may suggest that spleen colony studies are not suitable for prediction of events following bone marrow transplant into sublethally irradiated mice. Simultaneously, they have strengthened the necessity for appropriate conditioning of recipients of marrow transplants. (orig.) [de

  6. The effect of fractionated irradiation on cell kinetics

    International Nuclear Information System (INIS)

    Laasonen, A.; Pyrhoenen, S.; Kouri, M.; Raety, J.; Holsti, L.R.

    1991-01-01

    The effects of single and split-dose irradiation were compared by in vitro experiments on HeLa cells. Changes in rate of cell proliferation were detected by flow cytometry, simultaneously determining the DNA content and the bromodeoxyuridine incorporation of individual cells. Cell cultures were irradiated with either a single dose of 1-6 Gy or with a corresponding dose divided into multiple fractions given at 1-6-h intervals. A dose-dependent accumulation of cells in G2/M phase was observed. The method was sensitive enough for the detection of G2/M block even after 1 Gy. The block disappeared completely within a 24-h follow-up time at dose levels up to 3 Gy. Interestingly, no differences in cell kinetics were observed between the single and split-dose regiments. This approach proves to be valuable in evaluating novel fractionation models and the effects of radiation on the cell kinetics of human tumor cells. (orig.)

  7. Differentiation of bone marrow cells with irradiated bone in vitro

    International Nuclear Information System (INIS)

    Toshiyuki Tominaga; Moritoshi Itoman; Izumi, T.; Wakita, R.; Uchino, M.

    1999-01-01

    Disease transmission or infection is an important issue in bone allograft, and irradiation is used for sterilization of graft bones. One of the advantages of bone allograft over biomaterials is that graft bones have osteoinductive factors such as growth factors. Irradiation is reported to decrease the osteoinductive activity in vivo. We investigated the osteoinductive activity of irradiated bone by alkaline phosphatase (ALP) activity in rat bone marrow cell culture. Bones (tibias and femurs of 12-week-old Wistar rats) were cleaned of adhering soft tissue, and the marrow was removed by washing. The bones were defatted, lyophilized, and cut into uniform 70 mg fragments. Then the Bone fragments were irradiated at either 10, 20, 25, 30, 40, or 50 kGy at JAERI. Bone marrow cells were isolated from tibias and femurs of 4-week-old Wistar rats. Cells were plated in tissue culture flask. When primary cultures reached confluence, cells were passaged (4 x 103 cell / cm2) to 6 wells plates. The culture medium consisted of minimum essential medium, 10% fetal bovine serum, ascorbic acid, and antibiotics. At confluence, a cell culture insert was set in the well, and an irradiated bone fragment was placed in it. Then, medium was supplemented with 10 mM ?-glycerophosphate and 1 x 10-8 M dexamethasone. Culture wells were stained by naphthol AS-MX phosphate, N,N-dimethyl formamide, Red violet LB salt on day 0, 7, 14. The density of ALP staining was analyzed by a personal computer. Without bones, ALP staining increased by 50% on day 7 and by 100% on day 14, compared with that on day 0. The other side, with bones irradiated at 30 kGy or lower, ALP staining increased by 150% on day 7, and by 180% on day 14, compared with that on day 0. In the groups of irradiated bones of 40 kGy or higher, the increase in ALP staining was less prominent compared with the groups of irradiated bones of 30 kGy or lower. In the groups of 0-30 kGy irradiation, ALP staining increased in the early period

  8. An integrated on-line irradiation and in situ live cell imaging system

    Energy Technology Data Exchange (ETDEWEB)

    Liang, Ying; Fu, Qibin; Wang, Weikang; Liu, Yu; Liu, Feng; Yang, Gen, E-mail: gen.yang@pku.edu.cn; Wang, Yugang

    2015-09-01

    Ionizing radiation poses a threat to genome integrity by introducing DNA damages, particularly DNA double-strand breaks (DSB) in cells. Understanding how cells react to DSB and maintain genome integrity is of major importance, since increasing evidences indicate the links of DSB with genome instability and cancer predispositions. However, tracking the dynamics of DNA damages and repair response to ionizing radiation in individual cell is difficult. Here we describe the development of an on-line irradiation and in situ live cell imaging system based on isotopic sources at Institute of Heavy Ion Physics, Peking University. The system was designed to irradiate cells and in situ observe the cellular responses to ionizing radiation in real time. On-line irradiation was achieved by mounting a metal framework that hold an isotopic γ source above the cell culture dish for γ irradiation; or by integrating an isotopic α source to an objective lens under the specialized cell culture dish for α irradiation. Live cell imaging was performed on a confocal microscope with an environmental chamber installed on the microscope stage. Culture conditions in the environment chamber such as CO{sub 2}, O{sub 2} concentration as well as temperature are adjustable, which further extends the capacity of the system and allows more flexible experimental design. We demonstrate the use of this system by tracking the DSB foci formation and disappearance in individual cells after exposure to irradiation. On-line irradiation together with in situ live cell imaging in adjustable culture conditions, the system overall provides a powerful tool for investigation of cellular and subcellular response to ionizing radiation under different physiological conditions such as hyperthermia or hypoxia.

  9. An integrated on-line irradiation and in situ live cell imaging system

    International Nuclear Information System (INIS)

    Liang, Ying; Fu, Qibin; Wang, Weikang; Liu, Yu; Liu, Feng; Yang, Gen; Wang, Yugang

    2015-01-01

    Ionizing radiation poses a threat to genome integrity by introducing DNA damages, particularly DNA double-strand breaks (DSB) in cells. Understanding how cells react to DSB and maintain genome integrity is of major importance, since increasing evidences indicate the links of DSB with genome instability and cancer predispositions. However, tracking the dynamics of DNA damages and repair response to ionizing radiation in individual cell is difficult. Here we describe the development of an on-line irradiation and in situ live cell imaging system based on isotopic sources at Institute of Heavy Ion Physics, Peking University. The system was designed to irradiate cells and in situ observe the cellular responses to ionizing radiation in real time. On-line irradiation was achieved by mounting a metal framework that hold an isotopic γ source above the cell culture dish for γ irradiation; or by integrating an isotopic α source to an objective lens under the specialized cell culture dish for α irradiation. Live cell imaging was performed on a confocal microscope with an environmental chamber installed on the microscope stage. Culture conditions in the environment chamber such as CO 2 , O 2 concentration as well as temperature are adjustable, which further extends the capacity of the system and allows more flexible experimental design. We demonstrate the use of this system by tracking the DSB foci formation and disappearance in individual cells after exposure to irradiation. On-line irradiation together with in situ live cell imaging in adjustable culture conditions, the system overall provides a powerful tool for investigation of cellular and subcellular response to ionizing radiation under different physiological conditions such as hyperthermia or hypoxia

  10. An integrated on-line irradiation and in situ live cell imaging system

    Science.gov (United States)

    Liang, Ying; Fu, Qibin; Wang, Weikang; Liu, Yu; Liu, Feng; Yang, Gen; Wang, Yugang

    2015-09-01

    Ionizing radiation poses a threat to genome integrity by introducing DNA damages, particularly DNA double-strand breaks (DSB) in cells. Understanding how cells react to DSB and maintain genome integrity is of major importance, since increasing evidences indicate the links of DSB with genome instability and cancer predispositions. However, tracking the dynamics of DNA damages and repair response to ionizing radiation in individual cell is difficult. Here we describe the development of an on-line irradiation and in situ live cell imaging system based on isotopic sources at Institute of Heavy Ion Physics, Peking University. The system was designed to irradiate cells and in situ observe the cellular responses to ionizing radiation in real time. On-line irradiation was achieved by mounting a metal framework that hold an isotopic γ source above the cell culture dish for γ irradiation; or by integrating an isotopic α source to an objective lens under the specialized cell culture dish for α irradiation. Live cell imaging was performed on a confocal microscope with an environmental chamber installed on the microscope stage. Culture conditions in the environment chamber such as CO2, O2 concentration as well as temperature are adjustable, which further extends the capacity of the system and allows more flexible experimental design. We demonstrate the use of this system by tracking the DSB foci formation and disappearance in individual cells after exposure to irradiation. On-line irradiation together with in situ live cell imaging in adjustable culture conditions, the system overall provides a powerful tool for investigation of cellular and subcellular response to ionizing radiation under different physiological conditions such as hyperthermia or hypoxia.

  11. Genotoxic damage in non-irradiated cells: contribution from the bystander effect

    International Nuclear Information System (INIS)

    Zhou, H.; Randers-Pherson, G.; Suzuki, M.; Waldren, C.A.; Hei, T.K.

    2002-01-01

    It has always been accepted dogma that the deleterious effects of ionising radiation such as mutagenesis and carcinogenesis are due mainly to direct damage to DNA. Using the Columbia University charged-particle microbeam and the highly sensitive A L cell mutagenic assay, it is shown here that non-irradiated cells acquire the mutagenic phenotype through direct contact with cells whose nuclei are traversed with 2 alpha particles each. Pre-treatment of cells with lindane, a gap junction inhibitor, significantly decreased the mutant yield. Furthermore, when irradiated cells were mixed with control cells in a similar ration as the in situ studies, no enhancement in bystander mutagenesis was detected. Our studies provide clear evidence that genotoxic damage can be induced in non-irradiated cells, and that gap junction mediated cell-cell communication plays a critical role in the bystander phenomenon. (author)

  12. Cell shedding from X-irradiated multicellular spheroids of human lung carcinomas

    International Nuclear Information System (INIS)

    Sakata, K.; Okada, S.; Suzuki, N.; Majima, H.

    1991-01-01

    We studied the effect of radiation on cell shedding from the surface of multicellular spheroids. Spheroids were produced from two human lung cell lines, one adenocarcinoma (LCT1) and the other small cell carcinoma (LCT2), by using a liquid overlay culture technique. The number of cells shed from both kinds of spheroids did not change significantly when they were irradiated. The number of clonogenic cells shed from both kinds of irradiated spheroids decreased sharply as the dose of irradiation increases. There were no significant differences in clonogenic cell shedding per spheroid between LCT1 and LCT2 spheroids. 400 μm spheroids were more radioresistant to inhibition of clonogenic cell shedding than 250 μm spheroids. Shed cells were more radiosensitive than speroid cells. In these experiments, we did not obtain any results indicating that radiation enchances metastasis. (orig.) [de

  13. Local regulation of haemopoietic stem cell proliferation in mice following irradiation

    International Nuclear Information System (INIS)

    Ali, A.M.; Riches, A.C.; Wright, E.G.

    1989-01-01

    Changes in the kinetic state of pluripotent haemopoietic spleen colony forming cells (CFU-S) and of the CFU-S proliferation stimulator have been studied following whole-body X-irradiation. Rapid recruitment of CFU-S into cell cycle by 30 min after irradiation was observed following low doses (0.5 Gy) but a delay of 6 h occurred after higher doses (1.5 and 4.5 Gy). These changes in proliferative state correlated with the presence of the CFU-S proliferation stimulator. CFU-S irradiated in vitro in bone marrow plugs were also recruited into cycle illustrating directly the local nature of the feedback mechanism. CFU-S removed from 1.5 Gy irradiated recipients at a time when they were not in cycle were not responsive to the CFU-S proliferation stimulator. The CFU-S proliferation stimulator was produced by Ia positive cells in the irradiated bone marrow. The regulation changes occurring shortly after irradiation cannot simply be controlled by the size of the CFU-S compartment. (author)

  14. Effect of irradiation on cell cycle, cell death and expression of its related proteins in normal human oral keratinocytes

    International Nuclear Information System (INIS)

    Kang, Mi Ae; Heo, Min Suk; Lee, Sam Sun; Oh, Sung Ook; Choi, Soon Chul; Park, Tae Won; Lee, Sul Mi; Jeon, In Seong

    2003-01-01

    To investigate the radiosensitivity of the normal human oral keratinocytes (NHOK), and the effect of irradiation on cell cycle and protein expression. To evaluate the radiosensitivity of NHOK, the number of colonies and cells were counted after irradiation and the SF2 (survival fraction as 2 Gy) value, and the cell survival curve fitted on a linear-quadratic model were obtained. LDH analysis was carried out to evaluate the necrosis of NHOK at 1, 2,3, and 4 days after 2, 10, and 20 Gy irradiation. Cell cycle arrest and the induction of apoptosis were analyzed using flow cytometry at 1, 2, 3, and 4 days after 2, 10, and 20 Gy irradiation. Finally, proteins related cell cycle arrest and apoptosis were analysed by Western blot. The number of survival cell was significantly decreased in a dose-dependent manner. The cell survival curve showed SF2, α, and β values to be 0.568, 0.209, and 0.020 respectively. At 20 Gy irradiated cells showed higher optical density than the control group. After irradiation, apoptosis was not observed but G2 arrest was observed in the NHOK cells. 1 day after 10 Gy irradiation, the expression of p53 remained unchanged, the p21 WAF1/Cip1 increased and the mdm2 decreased. The expression of bax, bcl-2, cyclin B1, and cyclin D remained unchanged. These results indicate that NHOK responds to irradiation by G2 arrest, which is possibly mediated by the expression of p21 WAF1/Cip1 , and that cell necrosis occurs by high dose irradiation.

  15. Analysis of cell flow and cell loss following X-irradiation using sequential investigation of the total number of cells in the various parts of the cell cycle

    International Nuclear Information System (INIS)

    Skog, S.; Tribukait, B.

    1985-01-01

    The cell flow and cell loss of an in vivo growing Ehrlich ascites tumour were calculated by sequential estimation of changes in total number of cells in the cell cycle compartments. Normal growth was compared with the grossly disturbed cell flow evident after a 5 Gy X-irradiation. The doubling time of normal, exponentially growing cells was 24 hr. The generation time was 21 hr and the potential doubling time was 21 hr. Thus, the growth fraction was 1.0 and the cell loss rate about 0.5%/hr. Following irradiation, a transiently increased relative outflow rate from all cell cycle compartments was found at about 3 and 40 hr, and from S phase at 24 hr after irradiation. Increase in cell loss as well as non-viable cells was observed at 24 hr after irradiation at the time of release of the irradiation-induced G 2 blockage. The experiments show the applicability and limitations of cell flow and cell loss calculations by sequential analysis of the total number of cells in the various parts of the cell cycle. (author)

  16. Patterns of proliferation and differentiation of irradiated haemopoietic stem cells cultured on normal 'stromal' cell colonies in vitro

    International Nuclear Information System (INIS)

    Mori, K.J.

    1981-01-01

    Experiments were designed to elucidate whether or not the irradiated bone marrow cells receive any stimulation for the self-replication and differentiation from normal 'stromal' cell colonies in the bone marrow cell culture in vitro. When irradiated or unirradiated bone marrow cells were overlaid on the normal adherent cell colonies, the proliferation of haemopoietic stem cells was supported, the degree of the stimulation depending on the starting cellular concentration. There was, however, no significant changes in the concentration of either CFUs or CFUc regardless of the dose of irradiation on the bone marrow cells overlaid. This was a great contrast to the dose-dependent decrease of CFUs or CFUc within the culture in which both the stem cells and stromal cells were simultaneously irradiated. These results suggest that the balance of self-replication and differentiation of the haemopoietic stem cells is affected only when haemopoietic microenvironment is perturbed. (author)

  17. Differential induction from X-irradiated human peripheral blood monocytes to dendritic cells

    International Nuclear Information System (INIS)

    Yoshino, Hironori; Takahashi, Kenji; Monzen, Satoru; Kashiwakura, Ikuo

    2008-01-01

    Dendritic cells (DCs) are a type of antigen-presenting cell which plays an essential role in the immune system. To clarify the influences of ionizing radiation on the differentiation to DCs, we focused on human peripheral blood monocytes and investigated whether X-irradiated monocytes can differentiate into DCs. The non-irradiated monocytes and 5 Gy-irradiated monocytes were induced into immature DCs (iDCs) and mature DCs (mDCs) with appropriate cytokine stimulation, and the induced cells from each monocyte expressed each DC-expressing surface antigen such as CD40, CD86 and HLA-DR. However, the expression levels of CD40 and CD86 on the iDCs derived from the 5 Gy-irradiated monocytes were higher than those of iDCs derived from non-irradiated monocytes. Furthermore, the mDCs derived from 5 Gy-irradiated monocytes had significantly less ability to stimulate allogeneic T cells in comparison to the mDCs derived from non-irradiated monocytes. There were no significant differences in the phagocytotic activity of the iDCs and cytokines detected in the supernatants conditioned by the DCs from the non-irradiated and irradiated monocytes. These results suggest that human monocytes which are exposed to ionizing radiation can thus differentiate into DCs, but there is a tendency that X-irradiation leads to an impairment of the function of DCs. (author)

  18. Effect of ultraviolet irradiation on mast cell-deficient W/Wv mice

    International Nuclear Information System (INIS)

    Ikai, K.; Danno, K.; Horio, T.; Narumiya, S.

    1985-01-01

    The effect of UV irradiation on the skin was investigated in (WB-W/+) X (C57BL/6J-Wv/+)F1-W/Wv mice, which are genetically deficient in tissue mast cells. Their congenic littermates (+/+) and normal albino mice (ICR or BALB/c) were used as controls. Mice were irradiated with 500 mJ/cm2 of UVB and the increment of ear thickness was measured before and 6, 12, and 24 h after irradiation. Ear swelling in W/Wv mice at 12 and 24 h after irradiation was significantly smaller than that in +/+ and ICR mice. In contrast, the number of sunburn cells formed 24 h after UVB irradiation (200 or 500 mJ/cm2) was similar in W/Wv, +/+ and ICR mice. On the other hand, when mice were treated with 8-methoxy-psoralen (0.5%) plus UVA irradiation (4 J/cm2) (topical PUVA), ears of W/Wv and BALB/c mice, which were both white in color, were thickened similarly 72 h after treatment, but less swelling was observed in +/+ mice, which were black in skin color. The amount of prostaglandin D2 (PGD2) in ears, determined by radioimmunoassay specific for PGD2, was elevated 3-fold in +/+ and ICR mice at 3 h after irradiation with 500 mJ/cm2 of UVB in comparison with basal level without irradiation. However, such elevation was not observed in W/Wv mice. These results suggest that mast cells play an important role in UVB-induced inflammation, and PGs from mast cells are responsible at least in part for the development of this reaction. However, neither mast cells nor PGs contribute to the sunburn cell formation and ear swelling response by PUVA treatment

  19. Abnormal G1 arrest in the cell lines from LEC strain rats after X-irradiation

    International Nuclear Information System (INIS)

    Hayashi, M.; Uehara, K.; Kirisawa, R.; Endoh, D.; Arai, S.; Okui, T.

    1997-01-01

    The effect of X-irradiation of cell lines from LEC and WKAH strain rats on a progression o cell cycle was investigated. When WKAH rat ells were exposed to 5 Gy of X-rays and their cell cycle distribution was determined by a flow cytometer, the proportion of S-phase cells decrease and that of G2/M-phase cells in creased at 8 hr post-irradiation. At 18 and 24 hr post-irradiation, approximately 80% of the cells appeared in the G1 phase. On the contrary, the proportion of S-phase cells increased and that of G1-phase cells decreased in LEC rats during 8-24 hr post-irradiation, compared with that at 0 hr post-irradiation. Thus, radiation-induced delay in the progression from the G1 phase to S phase (G1 arrest) was observed inWKAH rat cells but not in LEC rat cells. In the case of WKAH rat cells, the intensities of the bands of p53 protein increased at 1 and 2 hr after X-irradiation at 5 Gy, compared with those of un-irradiated cells and at 0 hr post-irradiation. In contrast, the intensities of the bands were faint and did not significantly increase in LEC rat ells during 0-6 hr incubation after X-irradiation. Present results suggested that the radioresistant DNA synthesis in LEC rat cells is thought to be due to the abnormal G1 arrest following X-irradiation

  20. ''Protective'' effect of cells gamma-irradiation at the metaphase of mitosis after UV-irradiation at the S-period

    Energy Technology Data Exchange (ETDEWEB)

    Lebedeva, L I; Chubykin, V L [AN SSSR, Novosibirsk. Inst. Tsitologii i Genetiki

    1975-10-01

    As a result of the ultraviolet irradiation in vitro of the embryo fibroblasts of BALB mice in the S-stage with an incident dose of 40 erg/mm/sup 2/, 20.1% cells showed chromosome aberrations. Additional gamma irradiation of cells in the metaphase of the first mitosis with a dose of 5 krad leads with a high degree of certainty to a decrease to 11.7% in the frequency of aberrant cells observed in the same mitotic stage. The frequency of spontaneous aberrations does not change during the first few minutes after the gamma irradiation of intact cells. The ''protective'' effect of gamma rays cannot be attributed to non-uniform changes in the duration of the mitotic stages for aberrant and normal cells, to the adhesion of chromosome fragments or to the breaking of bridges in the anaphase. The destruction of cells during irradiation is also an unlikely explanation of the observed effect. It is assumed that the decrease in the frequency of aberrations is a result of the previously predicted modification of the processes involved, when potential chromosome damage becomes visible abberations during metaphase.

  1. Genomic instability induced by 137Cs γ-ray irradiation in CHL surviving cells

    International Nuclear Information System (INIS)

    Yue Jingyin; Liu Bingchen; Wu Hongying; Zhou Jiwen; Mu Chuanjie

    1999-01-01

    Objective: To study in parallel several possible manifestations of instability of surviving CHL cells after irradiation, namely the frequencies of mutation at locus, micronuclei and apoptosis. Methods: The frequencies of mutation at HGPRT locus, micronuclei and apoptosis were assayed at various times in surviving cells irradiated with γ-rays. Results: The surviving cells showed a persistently increased frequency of mutation at the HGPRT locus after irradiation until 53 days. Mutant fraction as high as 10 -4 was scored, tens of times higher than those assayed in control cells studied in parallel. The frequency of bi nucleated cells with micronuclei determined within 24 hours after irradiation increased with dose and reached a peak value of (26.58 +- 2.48)% at 3 Gy, decreasing at higher doses to a plateau around 20%. The micronucleus frequency decreased steeply to about (14.47 +- 2.39)% within the first 3 days post-irradiation, and fluctuated at around 10% up to 56 days post-irradiation. The delayed efficiency of irradiated cells was significantly decreased. The frequency of apoptosis peaked about (24.90 +- 4.72)% at 10 Gy 48 h post-irradiation (γ-ray dose between 3-10 Gy) and then decreased to about 12% within 3 days. It was significantly higher than in control cells until 14 days. Conclusions: It shows that genomic instability induced by radiation can be transmitted to the progeny of surviving cells and may take many forms of expression such as lethal mutation, chromosome aberrations, gene mutation, etc

  2. Medium from X-rayed cultures induces DNA strand-breaks in non-irradiated HeLa cells

    International Nuclear Information System (INIS)

    Ikushima, T.; Okuyama, K.; Tanizaki, Y.

    2002-01-01

    There is growing evidence to indicate that several types of responses are induced by ionizing radiation in non-irradiated cells. Such bystander effects include the killing of non-irradiated cells, the induction of sister chromatid exchanges and chromosomal aberrations, and the induction of gene mutations and chromosomal instability and enhanced cell growth. In the present study, we assessed whether the medium from irradiated cultures can induce DNA strand-breaks in non-irradiated cells, using single-cell gel electrophoresis assay (comet assay). HeLa cells in culture were irradiated with 0.5 to 8 Gy of 140 kVp X-rays and one hour later, the medium was taken from the irradiated culture, passed through a filter and transferred to the parallel culture of non-irradiated HeLa cells as non-target cells. After incubation for 30 min, the comet assay was performed under alkaline and neutral conditions. Such treatments resulted in a dose-dependent increase in tail moment under either alkaline or neutral condition, indicating the induction of DNA single- or double-strand breaks, respectively. It was also shown that the clonogenic survival was reduced in the cells cultured in the medium from irradiated cultures. Such a change was not detected at all when medium alone was irradiated. These results provided disputed evidence that irradiated cells released certain genotoxic factor(s) into the culture medium that can induce DNA strand breaks leading to cell death. Our results suggest that physical contact between irradiated and non-irradiated cells may not be necessary for the bystander effects observed in this study. It appears that bystander responses may be mediated by multiple mechanisms

  3. Effect of dihydroartemisinin on the cell cycle progress of irradiated human cervical cancer cell line and its mechanism

    International Nuclear Information System (INIS)

    Chen Xialin; Ji Rong; Cao Jianping; Zhu Wei; Fan Sanjun; Wang Jianfang; Cao Jianping

    2010-01-01

    Objective: To observe the changes of cell cycle on cancer cells after dihydroartemisinin and X-ray irradiation. Methods: Human HeLa cells of cervical cancer with p53 mutation was used and human SiHa cells of cervical cancer with wild p53 was used as control. Flow cytometry was used to detect the effect of dihydroartemisinin (20 and 100 μmol/L) and irradiation (6 Gy)on cell cycle. Western blot was used to measure the levels of cell cycle protein. Results: G 2 arrest was observed in irradiated HeLa cells, which the proportion of cells in G 2 phase was increased from 14.45% to 73.58% after 6 Gy X-ray irradiation, but it was abrogated by dihydroartemisinin from 73. 58% to 48.31% in HeLa cells, and it had no change on the SiHa cells. The elevated Wee1 protein and the lowered Cyclin B1 protein were observed with the G 2 arrest severity. The expression of radiation-induced Wee1 protein was suppressed and the Cyclin B1 protein was increased after dihydroartemisinin treatment, which was in accordance with the abrogation of radiation-induced G 2 delay. Conclusions: The main effect of irradiation on cell cycle of p53 mutated HeLa cells is G 2 arrest. Dihydroartemisinin could abrogate it, which is associated with the changes of Wee1 protein and Cyclin B1 protein. In Siha cells, the main effect of irradiation on cell cycle is G 1 arrest, and dihydroartemisinin has no effect on it. (authors)

  4. Intravenous injection of artificial red cells and subsequent dye laser irradiation causes deep vessel impairment in an animal model of port-wine stain.

    Science.gov (United States)

    Rikihisa, Naoaki; Tominaga, Mai; Watanabe, Shoji; Mitsukawa, Nobuyuki; Saito, Yoshiaki; Sakai, Hiromi

    2018-03-15

    Our previous study proposed using artificial blood cells (hemoglobin vesicles, Hb-Vs) as photosensitizers in dye laser treatment for port-wine stains (PWSs). Dye laser photons are absorbed by red blood cells (RBCs) and hemoglobin (Hb) mixture, which potentially produce more heat and photocoagulation and effectively destroy endothelial cells. Hb-Vs combination therapy will improve clinical outcomes of dye laser treatment for PWSs because very small vessels do not contain sufficient RBCs and they are poor absorbers/heaters of lasers. In the present study, we analyzed the relationship between vessel depth from the skin surface and vessel distraction through dye laser irradiation following intravenous Hb-Vs injection using a chicken wattle model. Hb-Vs were administered and chicken wattles underwent high-energy irradiation at energy higher than in the previous experiments. Hb-Vs location in the vessel lumen was identified to explain its photosensitizer effect using human Hb immunostaining of the irradiated wattles. Laser irradiation with Hb-Vs can effectively destroy deep vessels in animal models. Hb-Vs tend to flow in the marginal zone of both small and large vessels. Increasing laser power combined with Hb-Vs injection contributed for deep vessel impairment because of the synergetic effect of both methods. Newly added Hb tended to flow near the target endothelial cells of the laser treatment. In Hb-Vs and RBC mixture, heat transfer to endothelial cells from absorbers/heater may increase. Hb-Vs function as photosensitizers to destroy deep vessels within a restricted distance that the photon can reach.

  5. Chemosensitivity of irradiated resistant cells of multicellular spheroids in A549 lung adenocarcinoma

    International Nuclear Information System (INIS)

    Shi Degang; Shi Genming; Huang Gang

    2006-01-01

    Objective: To investigate the chemosensitivity of irradiated resistant cells of multicellular spheroids in A549 lung adenocarcinoma. Methods: The A549 irradiated resistant cells were the 10th regrowth generations after irradiated with 2.5 Gy of 6 MV X-ray, the control groups were A549 parent cells and MCFY/VCR resistant cells. The 6 kinds of chemotherapeutic drugs were DDP, VDS, 5-FU, HCP, MMC and ADM respectively, with verapamil (VPL) as reverse agent. The treatment effect was compared with MTT assay, and the multidrug resistant gene expressions of mdrl and MRP were measured with RT-PCR method. Results: A549 cells and irradiated resistant cells were resistant to DDP, but sensitivity to VDS,5-FU, HCP, MMC and ADM. The inhibitory rates of VPL to the above two cells were 98% and 25% respectively(P 2 -MG and MRP/β 2 -MG of all A549 cells were about 0 and 0.7 respectively, and those of MCFT/VCR cells were 35 and 4.36. Conclusion: The chemosensitivity of A549 irradiated resistant cells had not changed markedly, the decreased sensitivity to VPL could not be explained by the gene expression of mdrl and MRP. It is conferred that some kinds of changes in the cell membrane and decreased regrowth ability to result in resistance. Unlike multidrug resistance induced by chemotherapy, VPL may be not an ideal reverser to irradiated resistant cells. The new kinds of biological preparation should be sought to combine chemotherapy to treat recurring tumor with irradiated resistance. (authors)

  6. Loss of photoreactivation in UV-irradiated cultured fish cells under different conditions

    International Nuclear Information System (INIS)

    Mano, Y.; Kator, K.; Egami, N.

    1982-01-01

    CAF-MM1 cells derived from a goldfish have photoreactivability for the damage induced by ultraviolet light. When UV-irradiated cells were incubated in the dark at 26 0 C, the longest interval in which photoreactivation (PR) was observed, measured by colony formation technique, was about 30h after the UV irradiation. However, if the cells were incubated at 20 0 C, the effective time was prolonged. Since each time appeared to correspond to the doubling time of the cells at each temperature, the loss of photoreactivability is suggested to be closely related to cell growth or progression of cell cycle. The loss of PR was not observed in the cells held in confluence up to 48h after UV irradiation. Photoreactivating enzyme in growing CAF-MM1 cells incubated in the dark for 24h after UV irradiation was shown to be active, so that it is not possible that the cause of the loss of PR is change in the activity of photoreactivating enzyme. (author)

  7. Electron microscopic study of the spilt irradiation effects on the rat parotid ductal cells

    International Nuclear Information System (INIS)

    Kim, Sung Soo; Lee, Sang Rae

    1988-01-01

    This study was designed to investigate the effects of split irradiation on the salivary ductal cells, especially on the intercalated cells of the rat parotid glands. For this study, 24 Sprague-Dawley strain rats were irradiated on the head and neck region with two equal split doses of 9 Gy for a 4 hours interval by Co-60 teletherapy unit, Picker's mode l 4M 60. The conditions of irradiation were that field size, dose rate, SSD and depth were 12 X 5 cm, 222 cGy/min, 50 cm and 1 cm, respectively. The experimental animals were sacrificed 1, 2, 3, 6, 12, hours and 1, 3, 7, days after the irradiation and the changes of the irradiated intercalated cells of the parotid glands were examined under light and electron microscope. The results were as follows: 1. By the split irradiation, the degenerative changes of intercalated cells of the parotid glands appeared at 3 hours after irradiation and the most severe cellular degeneration observed at 6 hours after irradiation. The repair processes began from 12 hours after irradiation and have matured progressively. 2. Under electron microscope, loss of nuclear membrane, microvilli and secretory granules, derangement of chromosomes, degeneration of cytoplasm, atrophy or reduction of intracytoplasmic organelles were observed in the intercalated ductal cells after split irradiation. 3. Under light microscope, derangement of ductal cells, widening of cytoplasms and nuclei, hyperchromatism and proliferation of ductal cells were observed in intercalated ducts after split irradiation.

  8. Analysis of Giant-nucleated Cell Formation Following X-ray and Proton Irradiations

    Science.gov (United States)

    Almahwasi, Ashraf Abdu

    Radiation-induced genetic instability has been observed in survivors of irradiated cancerous and normal cells in vitro and in vivo and has been determined in different forms, such as delayed cell death, chromosomal aberration or mutation. A well defined and characterized normal human-diploid AG1522 fibroblast cell line was used to study giant-nucleated cell (GCs) formation as the ultimate endpoint of this research. The average nuclear cross-sectional areas of the AG1522 cells were measured in mum2. The doubling time required by the AG1522 cells to divide was measured. The potential toxicity of the Hoechst dye at a working concentration on the live AG1522 cells was assessed. The yield of giant cells was determined at 7, 14 and 21 days after exposure to equivalent clinical doses of 0.2, 1 or 2 Gy of X-ray or proton irradiation. Significant differences were found to exist between X-ray or proton irradiation when compared with sham-irradiated control populations. The frequency of GCs induced by X-rays was also compared to those formed in proton irradiated cultures. The results confirm that 1 Gy X-rays are shown to induce higher rates of mitotically arrested GCs, increasing continually over time up to 21 days post-irradiation. The yield of GCs was significantly greater (10%) compared to those formed in proton populations (2%) 21 days postirradiation. The GCs can undergo a prolonged mitotic arrest that significantly increases the length of cell cycle. The arrest of GCs at the mitotic phase for longer periods of time might be indicative of a strategy for cell survival, as it increases the time available for DNA repair and enables an alternative route to division for the cells. However, the reduction in their formation 21 days after both types of radiation might favour GCs formation, ultimately contributing to carcinogenesis or cancer therapy resistance. The X-ray experiments revealed a dose-dependent increase in the GCs up to 14 days after irradiation. Although the proton

  9. Stromal cell migration precedes hemopoietic repopulation of the bone marrow after irradiation

    International Nuclear Information System (INIS)

    Werts, E.D.; Gibson, D.P.; Knapp, S.A.; DeGowin, R.L.

    1980-01-01

    Circulation of hemopoietic stem cells into an irradiated site has been thoroughly documented, but migration of stromal cells to repair radiation damage has not. We determined the radiosensitivity of mouse bone marrow stroma and evaluated stromal and hemopoietic repopulation in x-irradiated marrow. The D 0 for growth of colonies of marrow stromal cells (MSC) was 215 to 230 rad. Total-body irradiation (TB) obliterated marrow stromal and hemopoietic cells within 3 days. In contrast, 1 day after 1000 rad leg irradiation (LI), MSC rose to 80% of normal, but fell to 34% by 3 days and recovered to 72% by 30 days. However, femoral nucleated cells diminished to 20% by 3 days and recovered to 74% of normal by 30 days. Likewise, differentiated marrow cells and hemopoietic stem cells were initially depleted. With 1000 rad LI followed 3 h later by 1000 rad to the body while shielding the leg, MSC and femoral nucleated cells recovered to values intermediate between 1000 rad TB and 1000 rad LI. We concluded that: (1) the D 0 for MSC was 215 to 230 rad, (2) stromal repopulation preceded hemopoietic recovery, and (3) immigration of stromal cells from an unirradiated sanctuary facilitated hemopoietic repopulation of a heavily irradiated site

  10. Cells of the J774 macrophage cell line are primed for antibody-dependent cell-mediated cytotoxicity following exposure to γ-irradiation

    International Nuclear Information System (INIS)

    Duerst, R.; Werberig, K.

    1991-01-01

    Activation of macrophages (M phi) for host defense against tumor cells follows a sequence of priming events followed by an initiating stimulus that results in production and release of cytotoxic molecules that mediate target cell killing. The authors have developed a model to study specific macrophage cytotoxicity in vitro utilizing a cultured murine M phi cell line, J774. Specific cytotoxicity of cultured human gastrointestinal tumor cells is achieved in the presence of murine IgG2a monoclonal antibody (mAb) 17-1-A. The ability of these cells to mediate antibody-dependent cell-mediated cytotoxicity (ADCC) is greatly enhanced following gamma-irradiation. ADCC can be demonstrated at mAb 17-1-A concentrations greater than or equal to 1 microgram/ml and effector/target cell ratios greater than or equal to 2. Exposure to doses greater than or equal to 10 Gy of gamma-irradiation increases ADCC threefold. Varying the duration from J774 M phi exposure to γ-irradiation until addition of antibody-coated target cells showed that the primed state for ADCC is stable for at least 8 days but approximately 24 hr is required for complete development of the primed state. mAb-dependent target cell death begins 8 hr after addition of mAb and labeled target cells to primed effector cells and is complete by 24 hr. Incubation of unirradiated J774 M phi effector cells with recombinant murine interferon-γ (rmIFN-γ) also results in enhanced ADCC, but the extent of target cell killing achieved is less than that following priming by γ-irradiation. Concomitant priming of γ-irradiated J774 M phi with rmIFN-γ increases the extent of ADCC. Further study of irradiated J774 cells may elucidate the molecular pathways utilized by M phi for achieving and maintaining the primed state for ADCC

  11. Survival of Lymphatic Cells after X-Irradiation in Mice

    Energy Technology Data Exchange (ETDEWEB)

    Vos, O. [Medical Biological Laboratory, National Defense Research Organization TNO, Ruswuk, Z.H. (Netherlands)

    1967-07-15

    Lymphatic tissues are generally classified among the most radiosensitive tissues of the body. The main reason for this is that histologically extensive destruction is found within a few hours after irradiation. We tried to estimate the degree of cellular degeneration by making cell suspensions from lymph nodes and thymus of mice at different times after X-irradiation with 800 R or at 24 h after radiation with different doses. The numbers of normal viable cells we obtained were expressed as percentages of the cells recovered from unirradiated control mice.

  12. Evaluation of cell proliferative activity after irradiation using immunohistochemical approach and flow cytometry

    Energy Technology Data Exchange (ETDEWEB)

    Tamada, Takashi (Okayama Univ. (Japan). School of Medicine)

    1992-06-01

    To evaluate a proliferative activity of post-irradiated malignant cells, we studied the kinetics of HeLa cells using immunohistochemical approach and flow cytometry. HeLa cells were stained with two proliferation-associated monoclonal antibodies, Ki-67 and anti-DNA polymerase {alpha} antibody. Nucleoli of non-irradiated cells were granularly stained with Ki-67. After irradiation, only the center of nuclei was diffusely stained with Ki-67. One hundred forty-four hours after low-dose irradiation, the staining patterns became the same as the control. On the other hand, after high-dose irradiation, the center of nuclei was weakly stained. DNA polymerase {alpha} was diffusely labelled with nuclei of the control. It was located around the border of nuclei of low-dose irradiated cells like a ring. But after high-dose irradiation, it was granularly distributed in the periphery of nuclei. FITC conjugated Ki-67/PI two parameter analysis was done by a single laser flow cytometer. Twenty-four hours after irradiation, DNA-histograms showed the accumulation to G{sub 2}/M phase and the increase of DNA content of G{sub 2}/M cells, as exposure dose was increased. Two parameter analysis showed the increase of FITC uptake of G{sub 2}/M phase as dose increased. These changes of flow cytometry were remarkably observed after 24 hours' incubation. It was shown that the difference of Ki-67 antigen and DNA polymerase {alpha} appearance depended on the irradiation dose. These findings suggest that immunohistochemical staining with Ki-67 or anti-DNA polymerase {alpha} antibody and flow cytometry using Ki-67 are available to evaluate cell damages after irradiation. (author).

  13. Interferon synthesis in mouse peritoneal cells damaged by x irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Szolgay, E; T' alas, M

    1976-01-01

    NDV-induced interferon of peritoneal cells of irradiated (x-rays, 400 R) and control mice was investigated in vitro. Irradiation or treatment with hydroxyurea (10(-5) M) and mitomycin C (25 microng/ml) did not change interferon synthesis in spite of an 80 to 90% inhibition of 3H-thymidine incorporation. Increased doses of mitomycin C and treatment with actinomycin D and puromycin blocked interferon production. De novo interferon synthesis occurred in cells with damaged replicative activity of DNA caused by irradiation or by treatment with antimetabolites.

  14. Effects of γ irradiation of hydra: elimination of interstitial cells from viable hydra

    International Nuclear Information System (INIS)

    Fradkin, M.; Kakis, H.; Campbell, R.D.

    1978-01-01

    Hydra attenuata and H. magnipapillata were γ-irradiated from a cesium source. All doses which had any observable effect (3000 rad and above) resulted in a reduction in the number of interstitial cells and of their differentiated product cells, or in the complete elimination of these cells. Interstitial cells were essentially completely eliminated within 5 days after irradiation doses above 5500 rad, and these hydra died. Irradiation doses of 4200 to 5500 rad resulted in a mixture of effects: some hydra recovered completely, some lost all interstitial cells and died, and some lost interstitial cells but could be propagated, as asexually reproducing clones, by hand feeding them. Hydra of some of these hand-fed clones entirely lacked interstitial cells and did not recover interstitial cells during subsequent culturing. Yet when these hydra were repopulated by interstitial cells from a normal hydra, they were restored to normal. Nerve cells became depleted more slowly than interstitial cells following irradiation, so animals can be obtained which possess nerve but no stem (interstitial) cells. The nerve cells and other derivatives of interstitial cells eventually disappear upon prolonged culture of the hydra. Thus γ irradiation can be used to eliminate interstitial cells from hydra, leaving viable polyps composed only of epithelial cells

  15. Cell Survival and DNA Damage in Normal Prostate Cells Irradiated Out-of-Field.

    LENUS (Irish Health Repository)

    Shields, L

    2014-10-31

    Interest in out-of-field radiation dose has been increasing with the introduction of new techniques, such as volumetric modulated arc therapy (VMAT). These new techniques offer superior conformity of high-dose regions to the target compared to conventional techniques, however more normal tissue is exposed to low-dose radiation with VMAT. There is a potential increase in radiobiological effectiveness associated with lower energy photons delivered during VMAT as normal cells are exposed to a temporal change in incident photon energy spectrum. During VMAT deliveries, normal cells can be exposed to the primary radiation beam, as well as to transmission and scatter radiation. The impact of low-dose radiation, radiation-induced bystander effect and change in energy spectrum on normal cells are not well understood. The current study examined cell survival and DNA damage in normal prostate cells after exposure to out-of-field radiation both with and without the transfer of bystander factors. The effect of a change in energy spectrum out-of-field compared to in-field was also investigated. Prostate cancer (LNCaP) and normal prostate (PNT1A) cells were placed in-field and out-of-field, respectively, with the PNT1A cells being located 1 cm from the field edge when in-field cells were being irradiated with 2 Gy. Clonogenic and γ-H2AX assays were performed postirradiation to examine cell survival and DNA damage. The assays were repeated when bystander factors from the LNCaP cells were transferred to the PNT1A cells and also when the PNT1A cells were irradiated in-field to a different energy spectrum. An average out-of-field dose of 10.8 ± 4.2 cGy produced a significant reduction in colony volume and increase in the number of γ-H2AX foci\\/cell in the PNT1A cells compared to the sham-irradiated control cells. An adaptive response was observed in the PNT1A cells having first received a low out-of-field dose and then the bystander factors. The PNT1A cells showed a significant

  16. Communicating the non-targeted effects of radiation from irradiated to non-irradiated cells

    International Nuclear Information System (INIS)

    Laiakis, E.C.; Morgan, W.F.

    2005-01-01

    For many years, the central dogma in radiobiology has been that energy deposited in the cell nucleus is responsible for the biological effects associated with radiation exposure. However, non-targeted and delayed effects of radiation have shifted this belief. The studies of radiation-induced genomic instability, the bystander and abscopal effects, clastogenic factors, and the Death Inducing Effect have dominated the interest of the radiobiology field of late. The passing of signals from irradiated to non-irradiated cells can be accomplished through cell-to-cell gap junction communication or secretion of molecules, which in turn can elicit a response through activation of signal transduction pathways. Proposed mediators of this phenotype include proteins involved with inflammation. Given their size and connection with oxidative stress, cytokines are an attractive candidate as mediators of the induction of the non-targeted effects of radiation. Here we review the evidence for a possible connection between these delayed non-targeted effects of radiation and the cytokine cascades associated with inflammation. (author)

  17. Loss of Ia-bearing splenic adherent cells after whole body ultraviolet irradiation

    International Nuclear Information System (INIS)

    Letvin, N.L.; Nepom, J.T.; Greene, M.I.; Benacerraf, B.; Germain, R.N.

    1980-01-01

    Daily uv irradiation of mice results in a marked decrease in the antigen-presenting capability of SAC from these mice after 1 wk of uv exposure. To directly examine this cell population, we developed a technique for purifying SAC that involves passing mouse splenocytes through two cycles of glass adherence with an intervening incubation on rabbit anti-mouse Ig-coated dishes. SAC from externally uv irradiated mice prepared by this method, when pulsed with antigen, activate primed T cells to proliferate much less efficiently than SAC from normal mice. Both the proportion and absolute number of Ia-bearing cells in this purified SAC population from uv irradiated mice are considerably smaller than that seen in similarly prepared populations from normal mice. Previous adjuvant immunization was shown to override functional defects elicited by external uv irradiation. This demonstration of a uv irradiation induced selective loss of Ia bearing splenic adherent cells and the functional consequences of this loss provide further evidence for the importance of Ia-bearing accessory cells in antigen presentation of T dependent antigens, and provides insight into the origin of the immunologic defects induced by whole body uv irradiation

  18. Sublethal irradiation promotes invasiveness of neuroblastoma cells

    International Nuclear Information System (INIS)

    Schweigerer, Lothar; Rave-Fraenk, Margret; Schmidberger, Heinz; Hecht, Monica

    2005-01-01

    Neuroblastoma is the most frequent extracranial solid tumour of childhood. Despite multiple clinical efforts, clinical outcome has remained poor. Neuroblastoma is considered to be radiosensitive, but some clinical studies including the German trial NB90 failed to show a clinical benefit of radiation therapy. The mechanisms underlying this apparent discrepancy are still unclear. We have therefore investigated the effects of radiation on neuroblastoma cell behaviour in vitro. We show that sublethal doses of irradiation up-regulated the expression of the hepatocyte growth factor (HGF) and its receptor c-Met in some neuroblastoma cell lines. The increase in HGF/c-Met expression was correlated with enhanced invasiveness and activation of proteases degrading the extracellular matrix. Thus, irradiation at sublethal doses may promote the metastatic dissemination of neuroblastoma cells through activating the HGF/c-Met pathway and triggering matrix degradation

  19. Partial reconstitution of virus-specific memory CD8+ T cells following whole body γ-irradiation

    International Nuclear Information System (INIS)

    Grayson, Jason M.; Laniewski, Nathan G.; Holbrook, Beth C.

    2006-01-01

    CD8 + memory T cells are critical in providing immunity to viral infection. Previous studies documented that antigen-specific CD8 + memory T cells are more resistant to radiation-induced apoptosis than naive T cells. Here, we determined the number and in vivo function of memory CD8 + T cells as immune reconstitution progressed following irradiation. Immediately following irradiation, the number of memory CD8 + T cells declined 80%. As reconstitution progressed, the number of memory cells reached a zenith at 33% of pre-irradiation levels, and was maintained for 120 days post-irradiation. In vitro, memory CD8 + T cells were able to produce cytokines at all times post-irradiation, but when adoptively transferred, they were not able to expand upon rechallenge immediately following irradiation, but regained this ability as reconstitution progressed. When proliferation was examined in vitro, irradiated memory CD8 + T cells were able to respond to mitogenic growth but were unable to divide

  20. Acceleration of astrocytic differentiation in neural stem cells surviving X-irradiation.

    Science.gov (United States)

    Ozeki, Ayumi; Suzuki, Keiji; Suzuki, Masatoshi; Ozawa, Hiroki; Yamashita, Shunichi

    2012-03-28

    Neural stem cells (NSCs) are highly susceptible to DNA double-strand breaks; however, little is known about the effects of radiation in cells surviving radiation. Although the nestin-positive NSCs predominantly became glial fibrillary acidic protein (GFAP)-positive in differentiation-permissive medium, little or no cells were GFAP positive in proliferation-permissive medium. We found that more than half of the cells surviving X-rays became GFAP positive in proliferation-permissive medium. Moreover, localized irradiation stimulated differentiation of cells outside the irradiated area. These results indicate for the first time that ionizing radiation is able to stimulate astrocyte-specific differentiation of surviving NSCs, whose process is mediated both by the direct activation of nuclear factor-κB and by the indirect bystander effect induced by X-irradiation.

  1. Growth of cells superinoculated onto irradiated and nonirradiated confluent monolayers

    International Nuclear Information System (INIS)

    Matsuoka, H.; Ueo, H.; Sugimachi, K.

    1990-01-01

    We prepared confluent monolayers of normal BALB/c 3T3 cells and compared differences in the growth of four types of cells superinoculated onto these nonirradiated and irradiated monolayers. The test cells were normal BALB/c 3T3 A31 cells, a squamous cell carcinoma from a human esophageal cancer (KSE-1), human fetal fibroblasts, and V-79 cells from Chinese hamster lung fibroblasts. Cell growth was checked by counting the cell number, determining [3H]thymidine incorporation and assessing colony formation. We found that on nonirradiated monolayers, colony formation of human fetal fibroblasts and normal BALB/c 3T3 cells was completely inhibited. On irradiated cells, test cells did exhibit some growth. KSE-1 cells, which had a low clonogenic efficiency on plastic surfaces, formed colonies on both irradiated and nonirradiated cells. On these monolayers, the clonogenic efficiency of V-79 cells was also higher than that on plastic surfaces. We conclude that the nonirradiated monolayer of BALB/c 3T3 cells completely inhibits the growth of superinoculated normal BALB/c 3T3 and human fetal fibroblasts, while on the other hand, they facilitate the growth of neoplastic KSE-1 and V-79 cells by providing a surface for cell adherence and growth, without affecting the presence of normal cells in co-cultures

  2. Skin allografts in lethally irradiated animals repopulated with syngeneic hemopoietic cells

    International Nuclear Information System (INIS)

    Schwadron, R.B.

    1983-01-01

    Total body irradiation and repopulation with syngeneic hemopoietic cells can be used to induce tolerance to major histocompatibility complex (MHC) mismatched heart and kidney grafts in rats and mice. However, this protocol does not work for MHC mismatched skin grafts in rats or mice. Furthermore, LEW rats that accept WF cardiac allografts after irradiation and repopulation reject subsequent WF skin grafts. Treatment of skin allograft donors with methotrexate prior to grafting onto irradiated and reconstituted mice resulted in doubling of the mean survival time. Analysis of which antigens provoked skin graft rejection by irradiation and reconstituted animals revealed the importance of I region antigens. Cardiac allograft acceptance by irradiated and reconstituted animals is mediated by suppressor cells found in the spleen. Adoptively tolerant LEW rats accepted WF skin grafts in 50% of grafted animals. Analysis of this phenomenon revealed that the adoptive transfer procedure itself was important in achieving skin allograft acceptance by these animals. In general, it seems that the lack of ability of irradiated and reconstituted animals to accept fully MHC disparate skin grafts results from the inability of these animals to suppress lymph node effector cells against I region antigen seen on highly immunogenic allogeneic Langerhans cells in the skin

  3. Mechanisms of taste bud cell loss after head and neck irradiation.

    Science.gov (United States)

    Nguyen, Ha M; Reyland, Mary E; Barlow, Linda A

    2012-03-07

    Taste loss in human patients following radiotherapy for head and neck cancer is a common and significant problem, but the cellular mechanisms underlying this loss are not understood. Taste stimuli are transduced by receptor cells within taste buds, and like epidermal cells, taste cells are regularly replaced throughout adult life. This renewal relies on progenitor cells adjacent to taste buds, which continually supply new cells to each bud. Here we treated adult mice with a single 8 Gy dose of x-ray irradiation to the head and neck, and analyzed taste epithelium at 1-21 d postirradiation (dpi). We found irradiation targets the taste progenitor cells, which undergo cell cycle arrest (1-3 dpi) and apoptosis (within 1 dpi). Taste progenitors resume proliferation at 5-7 dpi, with the proportion of cells in S and M phase exceeding control levels at 5-6 and 6 dpi, respectively, suggesting that proliferation is accelerated and/or synchronized following radiation damage. Using 5-bromo-2-deoxyuridine birthdating to identify newborn cells, we found that the decreased proliferation following irradiation reduces the influx of cells at 1-2 dpi, while the robust proliferation detected at 6 dpi accelerates entry of new cells into taste buds. In contrast, the number of differentiated taste cells was not significantly reduced until 7 dpi. These data suggest a model where continued natural taste cell death, paired with temporary interruption of cell replacement, underlies taste loss after irradiation.

  4. Immunity to Schistosoma mansoni in congenitally athymic, irradiated and mast cell-depleted rats

    International Nuclear Information System (INIS)

    Ford, M.J.; Bickle, Q.D.; Taylor, M.G.

    1987-01-01

    Immunity to Schistosoma mansoni was investigated in congenitally athymic (Nu/Nu) rats, irradiated rats and in mast cell-depleted rats. Nu/Nu rats failed to develop significant resistance following vaccination with irradiated cercariae, although Nu/Nu recipients of serum from vaccinated Fischer rats (VRS) manifested resistance comparable to heterozygous controls, suggesting that T-cells were required in the induction of resistance but were not involved in the efferent arm of antibody-dependent elimination. Radiosensitive cells (including eosinophils, basophils, neutrophils, lymphocytes and mast cells) were apparently not essential for the antibody-dependent elimination of lung or post-lung stages since irradiated (700-750 rad.) recipients of VRS manifested comparable degrees of resistance to unirradiated controls in spite of a greater than 85% reduction in total blood leucocyte counts after irradiation. Depletion of 99% of tissue mast cells by treatment of rats with Compound 48/80 had no significant effect on the attrition of a challenge infection in rats rendered immune by vaccination with irradiated cercariae or by transfer of VRS. However, there was a significant increase in worm recovery in unimmunized and mast cell-depleted or irradiated rats, indicating that mast cells and perhaps other radio-isotope sensitive cells may be involved in innate resistance. (author)

  5. Immunity to Schistosoma mansoni in congenitally athymic, irradiated and mast cell-depleted rats

    Energy Technology Data Exchange (ETDEWEB)

    Ford, M.J.; Bickle, Q.D.; Taylor, M.G.

    1987-04-01

    Immunity to Schistosoma mansoni was investigated in congenitally athymic (Nu/Nu) rats, irradiated rats and in mast cell-depleted rats. Nu/Nu rats failed to develop significant resistance following vaccination with irradiated cercariae, although Nu/Nu recipients of serum from vaccinated Fischer rats (VRS) manifested resistance comparable to heterozygous controls, suggesting that T-cells were required in the induction of resistance but were not involved in the efferent arm of antibody-dependent elimination. Radiosensitive cells (including eosinophils, basophils, neutrophils, lymphocytes and mast cells) were apparently not essential for the antibody-dependent elimination of lung or post-lung stages since irradiated (700-750 rad.) recipients of VRS manifested comparable degrees of resistance to unirradiated controls in spite of a greater than 85% reduction in total blood leucocyte counts after irradiation. Depletion of 99% of tissue mast cells by treatment of rats with Compound 48/80 had no significant effect on the attrition of a challenge infection in rats rendered immune by vaccination with irradiated cercariae or by transfer of VRS. However, there was a significant increase in worm recovery in unimmunized and mast cell-depleted or irradiated rats, indicating that mast cells and perhaps other radio-isotope sensitive cells may be involved in innate resistance.

  6. He-Ne laser irradiation affects proliferation of cultured rat Schwann cells in a dose-dependent manner

    International Nuclear Information System (INIS)

    Breugel, H.H.F.I. van; Bar, P.R.

    1993-01-01

    Schwann cell proliferation is considered an essential part of Wallerian degeneration after nerve damage. Laminin, an important component of the extracellular matrix and produced by Schwann cells, provides a preferred substrate for outgrowing axons. To study whether low energy (He-Ne) laser irradiation may exert a positive effect on nerve regeneration through an effect on Schwann cells, its effect was evaluated in vitro. Schwann cells were isolated from sciatic nerves of 4-5-day old Wistar rats and cultures on 96-multiwell plates. The cells were irradiated by a He-Ne laser beam. At three consecutive days, starting either at day 5 or day 8, cells were irradiated each day for 0.5, 1, 2, 5 or 10 min. Both cell number and laminin production were determined for each irradiation condition within one experiment. Schwann cells that were irradiated from day 8 on were hardly affected by laser irradiation. However, the proliferation of cells that were irradiated starting on day 5 was significantly increased after 1, 2 and 5 min of daily irradiation, compared to non-irradiated control cultures. The lamin production per cell of these Schwann cells was not significantly altered. From these results we conclude that He-Ne laser irradiation can modulate proliferation of rat Schwann cells in vitro in a dose-dependent manner. (Author)

  7. Loss of photoreactivation in UV-irradiated cultured fish cells under different conditions

    Energy Technology Data Exchange (ETDEWEB)

    Mano, Y.; Kator, K.; Egami, N. (Tokyo Univ. (Japan). Faculty of Science)

    1982-05-01

    CAF-MM1 cells derived from a goldfish have photoreactivability for the damage induced by ultraviolet light. When UV-irradiated cells were incubated in the dark at 26/sup 0/C, the longest interval in which photoreactivation (PR) was observed, measured by colony formation technique, was about 30h after the UV irradiation. However, if the cells were incubated at 20/sup 0/C, the effective time was prolonged. Since each time appeared to correspond to the doubling time of the cells at each temperature, the loss of photoreactivability is suggested to be closely related to cell growth or progression of cell cycle. The loss of PR was not observed in the cells held in confluence up to 48h after UV irradiation. Photoreactivating enzyme in growing CAF-MM1 cells incubated in the dark for 24h after UV irradiation was shown to be active, so that it is not possible that the cause of the loss of PR is change in the activity of photoreactivating enzyme.

  8. Karyometric observations of WISH cell cultures irradiated with 3 GHz microwaves

    Energy Technology Data Exchange (ETDEWEB)

    Szmigielski, S.; Luczak, M.; Wiranowska, M.

    1975-01-01

    WISH cell cultures 24 hours after passage were irradiated with 3 GHz microwaves (10 cm) at far field conditions in free space (anechoic chamber) for 30 minutes, at field power density 5 or 20 mW/cm/sup 2/. Within 1, 24, and 48 hours of the exposure to microwave fields the volumes of nuclei and nucleoli were measured with the use of a micrometer, and logvolumes and nucleo-nucleolar ratios were calculated. Under the applied irradiation conditions the culture medium temperature did not exceed 37/sup 0/C. In cultures irradiated at field power density 20 mW/cm/sup 2/ increased number of cells with small nuclei and enlarged nucleoli was noted within 1 hour of the exposure. Within 24 and 48 hours after irradiation the nucleolar volume showed a slight decrease, whereas the nuclear volume increased. In cultures irradiated at field power density 5 mW/cm/sup 2/ increased numbers of cells with enlarged nuclei and nucleoli were found. Analysis of the distribution curves of nuclear and nucleolar volumes suggests that non-thermal power densities of microwaves stimulate the metabolism of cell cultures. However, at higher power densities (20 mW/cm/sup 2/) the stimulation phase is preceded by a period of reduced viability of cell cultures.

  9. Effects on proliferation and cell cycle of irradiated KG-1 cells stimulated by CM-CSF

    International Nuclear Information System (INIS)

    Guo Dehuang; Dong Bo; Wen Gengyun; Luo Qingliang; Mao Bingzhi

    2000-01-01

    In order to explore the variety of cell proliferation and cell cycle after exposure to ionizing radiation, the responses of irradiated KG-1 cells of the human myeloid leukemia stimulated by GM-CSF, the most common used cytokine in clinic, were investigated. The results showed that GM-CSF enhance KG-1 cells proliferation, reduce G0/G1 block, increase S phase and G2/M phase. The stimulation effects of the GM-CSF are more effective in irradiated group than in control group

  10. Effects of 4000 rad irradiation on the in vitro storage properties of packed red cells

    International Nuclear Information System (INIS)

    Moore, G.L.; Ledford, M.E.

    1985-01-01

    Immunosuppressed patients who require red cell transfusions receive irradiated (1500-3000 rad) packed red cells. These cells are irradiated immediately before infusion. If a large group of patients become immunosuppressed due to exposure to radiation or chemicals, the ability to supply large volumes of irradiated blood at the time of use might not be possible. An alternate solution to providing quantities of irradiated blood is to irradiate the units prior to storage. This study presents in vitro data comparing storage of paired packed red cell units either irradiated or not irradiated. Five units of fresh blood drawn into citrate-phosphate-dextrose-adenine (CPDA-1) were packed to a hematocrit of 75 +/- 1 percent, and then each unit was divided in two equal parts. One of each pair was irradiated (4000 rads), and both parts of each unit were stored for 35 days at 4 degrees C. Samples were analyzed every 7 days. Irradiation caused a slight drop in red cell adenosine triphosphate and 2,3 diphosphoglycerate and a slight increase in plasma hemoglobin compared to controls. Methemoglobin, pH, and glucose consumption were identical to the controls. The evidence indicates that irradiation did not cause biochemical or metabolic changes in the red cells that would lead us to suspect a difference between irradiated and nonirradiated stored red cells in function or viability. These negative findings require in vivo confirmation

  11. The influence of Listeria monocytogenes cells on the primary immunologic response in irradiated mice

    International Nuclear Information System (INIS)

    Borowski, J.; Jokoniuk, P.

    1977-01-01

    The influence of killed Listeria monocytogenes cells on the primary immunologic response in mice irradiated with 300 or 500 R was studied. The immunologic response of the mice to sheep red blood cells used as antigen was assessed at the cellular level (by counting PFC) and humoral level. Injection of killed Listeria monocytogenes cells before irradiation of the mice diminished the immunosuppressive effect of roentgen radiation. Injection of the cells after irradiation accelerated regeneration of immunologic reactivity in the irradiated mice. (author)

  12. The Columbia University microbeam II endstation for cell imaging and irradiation

    International Nuclear Information System (INIS)

    Bigelow, A.W.; Ross, G.J.; Randers-Pehrson, G.; Brenner, D.J.

    2005-01-01

    The Columbia University Microbeam II has been built to provide a focused ion beam for irradiating designated mammalian cells with single particles. With the interest in irradiating non-stained cells and cells in three-dimensional tissue samples, the endstation was designed to accommodate a variety of imaging techniques, in addition to fluorescent microscopy. Non-stained cells are imaged either by quantitative phase microscopy (QPm) [IATIA, Box Hill North, Victoria, 3129, Australia [1

  13. Binucleate cell formation correlates to loss of colony-forming ability in X-irradiated cultured mammalian cells

    International Nuclear Information System (INIS)

    Sasaki, H.; Yoshinaga, H.; Kura, S.

    1986-01-01

    The relationship between binucleate cell formation and the loss of colony-forming ability was examined in several cultured mammalian cell lines irradiated with X rays. The maximum fraction of binucleate cells after X irradiation increased dose-dependently within the range in which reproductive cell death might predominate over interphase cell death. When the logarithm of percentage survival was plotted against the percentage binucleate cells, a similar correlation was found for all cell lines tested, with the exception of mouse leukemia L5178Y cells, the most radiosensitive cells used. These observations suggest that the fraction of binucleate cells in the cell population can serve as a measure of cellular radiation damage

  14. Effect of pepleomycin combined with irradiation on cultured Chinese hamster V79 cells

    International Nuclear Information System (INIS)

    Saito, Tsutomu

    1983-01-01

    The combined effect of pepleomycin (PEP), a bleomycin derivative, with irradiation was investigated on cultured Chinese hamster V79 cells. An additive effect was observed when PEP and irradiation were given simultaneously. A time interval between PEP (50μg/ml for one hour) and subsequent irradiation (10 Gy) increased the survival, and it became maximum when the time interval exceeded 2 hours. PEP-induced potentially lethal damage (PLD) was recovered when trysinization was delayed, and this recovery increased the survival. When PEP was given at a time interval after initial irradiation, the survival was decreased to below that following simultaneous treatment of the two modalities, and it became minimum when the time interval was 5 to 6 hours. Cells in ''G 2 -block'' induced by 10 Gy irradiation were partially synchronized, and cells in G 2 -M phase were more sensitive to PEP than those in S phase. It was considered that cells became more sensitive to PEP when they were irradiated 5 to 6 hours previously. However, cells recovery at any cell age when trypsinization was delayed. The benefit of a time interval between the two modalities was decreased by this recovery. (author)

  15. Long-term hematopoietic stem cell damage after external irradiation with X rays

    International Nuclear Information System (INIS)

    Grande, M.T.; Varas, F.; Bueren, J.A.

    1997-01-01

    We have investigated the functionality of the lympho-hematopoietic stem cells long-term (9 months) after the irradiation (X rays) of mice at different stages of development, by means of a competitive bone marrow repopulation assay. Our data revealed that a dose of 1 Gy was only capable of inducing significant long-term failures in the functionality of the primitive repopulating cells in mice irradiated at the young-adult stage (12 week-old), but not in mice irradiated at the late stages of foetus development (17 day-old fetuses) nor at the early development of the embryo (4 day-old embryos). The differential generation of long-term stem cell defects as a function of the age was confirmed in mice irradiated with 3 Gy. While no significant effects in the long-term repopulating cells were observed in 4 day-old embryos, significant repopulation deficiencies were observed in this population when mice were irradiated at the 17 day of foetus development, and more markedly at the adult stage of growth. These data offer new evidence about the influence of the developmental stage of the animal on the generation of residual hematopoietic dysfunctions by external irradiation, with particular relevance to the very primitive lympho-hematopoietic stem cells. (author)

  16. Cardiac arrest due to hyperkalemia following irradiated packed red cells transfusion

    Energy Technology Data Exchange (ETDEWEB)

    Miyazawa, Kazuharu [Yamamoto-kumiai General Hospital, Noshiro, Akita (Japan); Ohta, Sukejuurou; Kojima, Yukiko; Mizunuma, Takahide; Nishikawa, Toshiaki

    1998-11-01

    We describe two cases of cardiac arrest due to hyperkalemia following transfusion of irradiated packed red cells. Case 1: Because sudden, rapid and massive hemorrage occurred in a 69-year-old male patient undergoing the left lobectomy of the liver, 8 units of irradiated packed red cells were rapidly transfused, the patient developed cardiac arrest. Serum kalium concentration after transfusion was 7.6 mEq/l. Case 2: A 7-month-old girl scheduled for closure of a ventricular septal defect, developed cardiac arrest due to hyperkalemia at the start of cardiopulmonary bypass. The extracorporeal circuit was primed with 6 units of irradiated packed red blood cells. Serum kalium concentration immediately after the start of cardiopulmonary bypass was 10.6 mEq/l. Analysis of kalium concentration in the pilot tubes of the same packs revealed 56-61 mEq/l. These case reports suggest that fresh irradiated packed red cells should be transfused during massive bleeding and for pediatric patients to prevent severe hyperkalemia. (author)

  17. Effects of X-ray irradiation combined with hyperthermia on human bone marrow cells

    International Nuclear Information System (INIS)

    Xie Huaijiang; Niu Rongjiu; Liu Xiaodong; Liu Huanqin

    1996-01-01

    The authors report on the effects of X-ray irradiation combined with hyperthermia on human bone marrow cells (BMC) in vitro. Observation was made on the morphology of treated cells under optic microscope and ultrastructural changes under electron microscope. The change was not obvious at first after treatment i,e, only the vacuolar degeneration was observed in a few cells under the EM. The survival of BMC alone after irradiation decreased with increase of the irradiation dose. The morphological changes included vacuolar degeneration of cells, swelling of mitochondria, and disintegration of nuclear membranes. The survival rate of BMC after irradiation combined with hyperthermia was significantly lower than that after treatment by either of them alone (P<0.01). The morphological changes were as follows: the cell structure was destroyed, the cell support system and cell organelles were destroyed, the cell membrane and nuclear membranes were destroyed, and the cell plasma and nuclear sap overflowed

  18. The effect of resveratrol in combination with irradiation and chemotherapy. Study using Merkel cell carcinoma cell lines

    International Nuclear Information System (INIS)

    Heiduschka, G.; Lill, C.; Brunner, M.; Thurnher, D.; Seemann, R.; Schmid, R.; Houben, R.; Bigenzahn, J.

    2014-01-01

    Merkel cell carcinoma (MCC) is a rare, but highly malignant tumor of the skin. In case of systemic disease, possible therapeutic options include irradiation or chemotherapy. The aim of this study was to evaluate whether the flavonoid resveratrol enhances the effect of radiotherapy or chemotherapy in MCC cell lines. The two MCC cell lines MCC13 and MCC26 were treated with increasing doses of resveratrol. Combination experiments were conducted with cisplatin and etoposide. Colony forming assays were performed after sequential irradiation with 1, 2, 3, 4, 6, and 8 Gy and apoptosis was assessed with flow cytometry. Expression of cancer drug targets was analyzed by real-time PCR array. Resveratrol is cytotoxic in MCC cell lines. Cell growth is inhibited by induction of apoptosis. The combination with cisplatin and etoposide resulted in a partially synergistic inhibition of cell proliferation. Resveratrol and irradiation led to a synergistic reduction in colony formation compared to irradiation alone. Evaluation of gene expression did not show significant difference between the cell lines. Due to its radiosensitizing effect, resveratrol seems to be a promising agent in combination with radiation therapy. The amount of chemosensitizing depends on the cell lines tested. (orig.) [de

  19. Repopulated antigen presenting cells induced an imbalanced differentiation of the helper T cells in whole body gamma irradiated mice

    Energy Technology Data Exchange (ETDEWEB)

    Park, Hae Ran; Jo, Sung Kee [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of); Paik, Sang Kee [Chungnam National University, Taejon (Korea, Republic of)

    2004-07-01

    Therapeutic irradiation of cancer patients, although it may be protected by several antioxidant agents against free radicals, often induces chronic sequelae such as inflammation (allergic inflammation). This is a limiting factor for radiotherapy. Following radiotherapy, the inflammation or injury can occur in any organ with a high radiosensitivity such as the lung, bladder, kidney, liver, stomach and intestine. The mechanism by which ionizing radiation initiates inflammation is, however, poorly understood. In recent studies, it was suggested that a factor for irradiation-induced inflammation might be the over production of IL-4 that enhances fibroblast proliferation and collagen synthesis. During the early stages after irradiation, type 2 of the helper T cells might be the major source of IL-4, and later on there seems to be an activation of the other IL-4 producing cell types, e.q. macrophages or mast cells. This is interesting because inflammation is classically seen to be dominated by Th1 cells secreting IFN-{gamma}. In the previous study, we were interested in the enhancement of the IL-4 and the IgE production during the development of immune cells after {gamma}-irradiation. We were able to deduce that IL-4 production was increased because of the shifted differentiation of the naive Th cells by the repopulated antigen presenting cells after irradiation. The aim of the present study was to precisely define whether antigen-presenting cells (APCs) of whole body irradiation-treated mice could influence the shifted differentiation of the Th cells. This view can be demonstrated by confirming that the shifted functional status of the Th cells is induced by the altered function of the repopulated macrophages after whole body irradiation (WBI)

  20. Immobilization of cellulose producing cells (sporotrichum cellulophilum) using irradiated rice husk as a substrate

    International Nuclear Information System (INIS)

    Lina, M.R.; Tamada, M.; Kumakura, M.

    1991-01-01

    An experiment to study the effect of irradiated rice husk as a substrate on cellulase production of free and immobilized cells of S. cellulophium was carried out. Radiation pretreatment of rice husk was done using electron beam accelerator (Dynamitron IEA 3000-25,2), with doses of 0, 0.2, 0.4, 0.6, 0.8, and 1.0 MGy. The substrate used in cellulase production of free and immobilized cells were cellulose powder as a standard, and 1.0 MGy irradiated rice husk. Concentrations of cellulose powder for free and immobilized cells were 1, 2, 3, 5, and 8% (w/v). Irradiated rice husk concentrations for free cells were 3, 6, 9, 15, and 24% (w/v), whereas for immobilized cells were 3, 6, and 9% (w/v). Results showed that glucose concentration in 1.0 MGy irradiated rice husk was the highest of all irradiated and unirradiated rice husks. The GPA (glucose production activity) values used of free immobilized cells of S. cellulophium in medium containing 1.0 MGy irradiated rice husk were about 50% lower than in cellulose powder medium. Cellulase solution resulted by immobilized cells, either in cellulose powder or in irradiated rice husk media, were clear and did not contain mycelium. (authors). 7 refs, 7 figs

  1. The effect of x-ray irradiation on proliferation and differentiation of epithelial cells in mouse skin

    International Nuclear Information System (INIS)

    Tanabe, Akira

    1980-01-01

    To elucidate radiation injuries and the recovery mechanism of epithelial cells exposed to 150 R or 450 R of x-ray, the epidermal proliferative unit (EPU) in the backs of mice was analysed histologically and dynamically by measuring the labelled index of cells with 3 H-thymidine and measuring differentiation index of cells. EPU was normal for 6 days after irradiation with both 150 R and 450 R. However, partial hyperplasia and EPU disorders in a range consistent with hyperplasia appeared in segmented preparations 7 days after irradiation. Both doses inhibited cell differentiation for 5 days after irradiation. Cell proliferation, which was higher than the normal rate, peaked 7 days after irradiation with 150 R and 9 days after irradiation with 540 R. Cell proliferation returned to normal 10 days after irradiation. DNA synthesis was inhibited one day after irradiation with both 150 R and 450 R, but it returned to normal 3 days after irradiation. There was an overshoot of DNA synthesis, but synthesis returned to normal 9 days after irradiation with 150 R and 12 days after irradiation with 450 R. EPU disorders returned to normal according to normalization of cell differentiation and DNA synthesis. (Tsunoda, M.)

  2. The effects of pervanadate given at different times on the proliferation of irradiated NFS-60 cells

    International Nuclear Information System (INIS)

    Wang Yuan; Yuan Xiaoling; Zhao Zhenhu; Shan Yajun; Chen Jiapei; Cong Yuwen

    2004-01-01

    To comprehend the feasibility of the inhibitor of tyrosine phosphatase pervanadate using for therapy of radiation injury and inquire into the effects of tyrosine phosphatases on the radiation injury of hematopoietic cells, the effects of different times of administration on NFS-60 cells irradiated with different doses were observed. It was found that pervanadate could specifically enhance the proliferation of irradiated cells, such effects became obvious with the dose of irradiation increased and displayed time effects. For 3 Gy irradiated NFS-60 cells, good results were achieved when pervanadate was administrated 24h after irradiation, there were no difference between before and 30 mins after irradiation, but for 5 Gy irradiated cells, the best time administration is 24 and 48h after irradiation. Effects of pervanadate administrated before irradiation was better than that administrated 30 min after irradiation. These results suggest that protein tyrosine phosphatase might involve in the course of radiation injury of hematopoietic cells. It is hoped that enhancing receptor signal transduction by PTP inhibitors will become a new way of therapy of acute radiation disease

  3. Simultaneous electron-proton irradiation of crucible grown and float-zone silicon solar cells

    International Nuclear Information System (INIS)

    Bernard, J.

    1974-01-01

    The realisation of an irradiation chamber which permits simultaneous irradiations by electrons, protons, photons and in-situ measurements of solar cells main parameters (diffusion length, I.V. characteristics) is described. Results obtained on 20 solar cells n/p 10Ωcm made in silicon pulled crystals and 20 solar cells n/p 10Ωcm made in silicon float-zone simultaneously irradiated with electrons and photons are given [fr

  4. Study on apoptosis of prostate cancer cell induced by 125I seed irradiation

    International Nuclear Information System (INIS)

    Liao Anyan; Wang Junjie; Wang Jidong; Zhuang Hongqing; Zhao Yong

    2007-01-01

    Objective: To explore the mechanism of apoptosis induced by 125 I seed irradiation on PC3 cells. Methods: Human prostate cancer cell line PC3 was treated by irradiation of 125 I (2.77 cGy/h) with various dose. Agarose gel electrophoresis of DNA and flows cytometry were used to detect the apoptosis of PC3 cells and indirect immunofluorescence assay was used to detect the expression of Bcl-2. The activity of Caspase-3 was measured by Caspase Colorimetric Assay Kits. Results: Apoptosis of PC3 cells could be efficiently induced by 125 I seed irradiation. The apoptotic peaks were found by flow cytometry and DNA ladder appeared on 1.8% agarose gel. The activity of Caspase-3 on PC3 cells treated by 125 I seed irradiation was not changed significantly. Bcl-2 gene expression was down-regulated with the sample concentration increased. Conclusion: 125 I irradiation can induce the apoptosis of PC3 cells and the mechanism of apoptosis is related with down regulation of Bcl-2 gene expression and is not related with Caspase-3 activity. (authors)

  5. Susceptible genes and molecular pathways related to heavy ion irradiation in oral squamous cell carcinoma cells

    International Nuclear Information System (INIS)

    Fushimi, Kazuaki; Uzawa, Katsuhiro; Ishigami, Takashi; Yamamoto, Nobuharu; Kawata, Tetsuya; Shibahara, Takahiko; Ito, Hisao; Mizoe, Jun-etsu; Tsujii, Hirohiko; Tanzawa, Hideki

    2008-01-01

    Background and purpose: Heavy ion beams are high linear energy transfer (LET) radiation characterized by a higher relative biologic effectiveness than low LET radiation. The aim of the current study was to determine the difference of gene expression between heavy ion beams and X-rays in oral squamous cell carcinoma (OSCC)-derived cells. Materials and methods: The OSCC cells were irradiated with accelerated carbon or neon ion irradiation or X-rays using three different doses. We sought to identify genes the expression of which is affected by carbon and neon ion irradiation using Affymetrix GeneChip analysis. The identified genes were analyzed using the Ingenuity Pathway Analysis Tool to investigate the functional network and gene ontology. Changes in mRNA expression in the genes were assessed by real-time quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR). Results: The microarray analysis identified 84 genes that were modulated by carbon and neon ion irradiation at all doses in OSCC cells. Among the genes, three genes (TGFBR2, SMURF2, and BMP7) and two genes (CCND1 and E2F3), respectively, were found to be involved in the transforming growth factor β-signaling pathway and cell cycle:G1/S checkpoint regulation pathway. The qRT-PCR data from the five genes after heavy ion irradiation were consistent with the microarray data (P < 0.01). Conclusion: Our findings should serve as a basis for global characterization of radiation-regulated genes and pathways in heavy ion-irradiated OSCC

  6. Chromosome aberrations and cell survival in irradiated mammalian cells

    International Nuclear Information System (INIS)

    Tremp, J.

    1981-01-01

    A possible correlation between chromosome aberrations and reduced proliferation capacity or cell death was investigated. Synchronized Chinese hamster fibroblast cells were irradiated with 300 rad of x rays in early G 1 . Despite synchronization the cells reached the subsequent mitosis at different times. The frequency of chromosome aberrations was determined in the postirradiation division at 2-h intervals. The highest frequency occurred in cells with a first cell cycle of medium length. The colony-forming ability of mitotic cells was measured in parallel samples by following the progress of individual mitoses. The proportion of cells forming macrocolonies decreased with increasing cell cycle length, and the number of non-colony-forming cells increased. Irrespective of various first cell cycle lengths and different frequencies of chromosome aberrations, the number of cells forming microcolonies remained constant. A correlation was found between the absence of chromosome aberrations and the ability of cells to form macrocolonies. However, cells with a long first cell cycle formed fewer macrocolonies than expected

  7. Survival and antigenic profile of irradiated malarial sporozoites in infected liver cells

    International Nuclear Information System (INIS)

    Suhrbier, A.; Winger, L.A.; Castellano, E.; Sinden, R.E.

    1990-01-01

    Exoerythrocytic (EE) stages of Plasmodium berghei derived from irradiated sporozoites were cultured in vitro in HepG2 cells. They synthesized several antigens, predominantly but not exclusively those expressed by normal early erythrocytic schizonts. After invasion, over half the intracellular sporozoites, both normal and irradiated, appeared to die. After 24 h, in marked contrast to the normal parasites, EE parasites derived from irradiated sporozoites continued to break open, shedding their antigens into the cytoplasm of the infected host cells. Increasing radiation dosage, which has previously been shown to reduce the ability of irradiated sporozoites to protect animals, correlated with reduced de novo antigen synthesis by EE parasites derived from irradiated sporozoites

  8. Evaluation of cell behavior on modified polypropylene with swift heavy ion irradiation

    International Nuclear Information System (INIS)

    Arbeitman, Claudia R.; Ibañez, Irene L.; García Bermúdez, Gerardo; Durán, Hebe; Grosso, Mariela F. del; Salguero, Noelia; Mazzei, Rubén

    2012-01-01

    Ion beam irradiation is a well known means to change the physico-chemical properties of polymers, and induced bio and citocompatibility in controlled conditions and in selected areas of surface. However, the enhancement of cell adhesion on a modified substrate does not mean that the surface is adequate for functional cells. The purpose of the present work is to study proliferation, changes in cytoskeleton and cell morphology on substrates as a function of irradiation parameters. We irradiated polypropylene with sulfur (S) ion-beam at energies of 110 MeV with fluences between 1 × 10 6 and 2 × 10 10 ions cm −2 . NIH 3T3 cells were cultured on each sample. Cell morphology was observed using phase contrast microscopy and cytoskeleton proteins with fluorescence microscopy. The analysis show different cellular responses as a functions of irradiation parameter, strongly suggests that different underlying substratum can result in distinct types of cytoskeleton reorganization.

  9. Evaluation of cell behavior on modified polypropylene with swift heavy ion irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Arbeitman, Claudia R., E-mail: arbeitman@tandar.cnea.gov.ar [Gerencia de Investigacion y Aplicaciones, TANDAR-CNEA, Av. Gral. Paz 1499, 1650 San Martin, Bs. As. (Argentina); CONICET, Av. Rivadavia 1917, C1033AAJ, CABA (Argentina); Ibanez, Irene L. [CONICET, Av. Rivadavia 1917, C1033AAJ, CABA (Argentina); Garcia Bermudez, Gerardo [Gerencia de Investigacion y Aplicaciones, TANDAR-CNEA, Av. Gral. Paz 1499, 1650 San Martin, Bs. As. (Argentina); CONICET, Av. Rivadavia 1917, C1033AAJ, CABA (Argentina); Duran, Hebe [CONICET, Av. Rivadavia 1917, C1033AAJ, CABA (Argentina); Gerencia de Desarrollo Tecnologico y Proyectos Especiales, TANDAR-CNEA (Argentina); Grosso, Mariela F. del [Gerencia de Investigacion y Aplicaciones, TANDAR-CNEA, Av. Gral. Paz 1499, 1650 San Martin, Bs. As. (Argentina); CONICET, Av. Rivadavia 1917, C1033AAJ, CABA (Argentina); Salguero, Noelia [Gerencia de Investigacion y Aplicaciones, TANDAR-CNEA, Av. Gral. Paz 1499, 1650 San Martin, Bs. As. (Argentina); Mazzei, Ruben [U.A. Tecnologicas y Agropecuarias, CNEA (Argentina)

    2012-02-15

    Ion beam irradiation is a well known means to change the physico-chemical properties of polymers, and induced bio and citocompatibility in controlled conditions and in selected areas of surface. However, the enhancement of cell adhesion on a modified substrate does not mean that the surface is adequate for functional cells. The purpose of the present work is to study proliferation, changes in cytoskeleton and cell morphology on substrates as a function of irradiation parameters. We irradiated polypropylene with sulfur (S) ion-beam at energies of 110 MeV with fluences between 1 Multiplication-Sign 10{sup 6} and 2 Multiplication-Sign 10{sup 10} ions cm{sup -2}. NIH 3T3 cells were cultured on each sample. Cell morphology was observed using phase contrast microscopy and cytoskeleton proteins with fluorescence microscopy. The analysis show different cellular responses as a functions of irradiation parameter, strongly suggests that different underlying substratum can result in distinct types of cytoskeleton reorganization.

  10. Enhanced thermal stability of a polymer solar cell blend induced by electron beam irradiation in the transmission electron microscope

    Energy Technology Data Exchange (ETDEWEB)

    Bäcke, Olof, E-mail: obacke@chalmers.se [Department of Applied Physics, Chalmers University of Technology, 41296 Göteborg (Sweden); Lindqvist, Camilla; Diaz de Zerio Mendaza, Amaia [Department of Chemistry and Chemical Engineering, Chalmers University of Technology, 41296 Göteborg (Sweden); Gustafsson, Stefan [Department of Applied Physics, Chalmers University of Technology, 41296 Göteborg (Sweden); Wang, Ergang; Andersson, Mats R.; Müller, Christian [Department of Chemistry and Chemical Engineering, Chalmers University of Technology, 41296 Göteborg (Sweden); Kristiansen, Per Magnus [Institute of Polymer Nanotechnology (INKA), FHNW University of Applied Science and Arts Northwestern Switzerland, 5210 Windisch (Switzerland); Laboratory for Micro- and Nanotechnology, Paul Scherrer Institute, 5232 Villigen (Switzerland); Olsson, Eva, E-mail: eva.olsson@chalmers.se [Department of Applied Physics, Chalmers University of Technology, 41296 Göteborg (Sweden)

    2017-05-15

    We show by in situ microscopy that the effects of electron beam irradiation during transmission electron microscopy can be used to lock microstructural features and enhance the structural thermal stability of a nanostructured polymer:fullerene blend. Polymer:fullerene bulk-heterojunction thin films show great promise for use as active layers in organic solar cells but their low thermal stability is a hindrance. Lack of thermal stability complicates manufacturing and influences the lifetime of devices. To investigate how electron irradiation affects the thermal stability of polymer:fullerene films, a model bulk-heterojunction film based on a thiophene-quinoxaline copolymer and a fullerene derivative was heat-treated in-situ in a transmission electron microscope. In areas of the film that exposed to the electron beam the nanostructure of the film remained stable, while the nanostructure in areas not exposed to the electron beam underwent large phase separation and nucleation of fullerene crystals. UV–vis spectroscopy shows that the polymer:fullerene films are stable for electron doses up to 2000 kGy. - Highlights: • Thermal stability of a polymer: fullerne blend is increased using electron irradiation. • Using in-situ transmission electron microscopy the nanostructure is studied. • Electron irradiation stops phase separation between the polymer and fullerene. • Electron irradiation quenches the formation and nucleation of fullerene crystals.

  11. Effects of X-irradiation on membranes of tumor cells

    International Nuclear Information System (INIS)

    Fonck, K.

    1982-01-01

    The aim of the investigation was to gain more insight into the effect of ionizing radiation on biomembranes, especially the membrane phospholipids. A general outline of the experimental approach is given in the first chapter. The influence of membrane-active agents and hyperthermia on cell survival after irradiation was studied. Phospholipid turnover was followed by measuring the incorporation of radioactive precursors. The second chapter is an introduction to general radiobiology and to phospholipid metabolism. After the presentation of some physico-chemical properties of ionizing radiation, the effects on cells and cellular components are described. In chapters 3 to 6 the experimental part is described. Chapter 3 starts with the determination of the cellular survival of L5178Y lymphoma cells after X-irradiation. In chapter 4 the lipid composition of lymphosarcoma cell nuclei is presented and in chapter 5 studies on the effect of X-irradiation on the incorporation of palmitate and arachidonate into the phospholipids of lymphosarcoma cells are described. Chapter 6 describes experiments in which lymphosarcoma cells isolated from the spleens of tumor-bearing mice were used to study the effect of a low dose of X-rays (5 Gy) on the incorporation of [ 3 H]palmitate and [ 14 C]arachidonate into the lipids of the tumor cells. These fatty acids were rapidly incorporated especially into the phospholipids of the cells. Chapter 7 contains a general discussion on the experimental results. (Auth.)

  12. Irradiation effect on the apoptosis induction in the human cancer cell lines and the gingival fibroblast

    International Nuclear Information System (INIS)

    Park, Mu Soon; Lee, Sam Sun; Choi, Soon Chul; Park, Tae Won; You, Dong Soo

    1998-01-01

    The radiation-induced apoptosis was studied for two human cancer cell lines (KB cells, RPMI 2650 cells) and the human gingival fibroblast cell line (HGF-1 cells). The single irradiation of 2, 10, 20 Gy was done with 241.5 cGy/min dose rate using the 137 Cs MK cell irradiator. The cell were stained with propidium iodide and examined under the fluoro-microscope and assayed with the flow cytometry a day after irradiation. Also, the LDH assay was done to determine the amount of necrotic cells. The obtained results were as follows : 1. On the fluoro-microscope, many fragmented nuclei were detected in the KB, RPMI 2650, and HGF-1 cells after irradiation. 2. On the DNA content histogram obtained from the flow cytometry, the percentages of the pre-G1 peak of the control and 2, 10 and 20 Gy irradiation group were 4.5, 55.0, 52.3, and 66.6% on KB cells, 2.7, 3.3, 31.8, and 32.6% on RPMI 2650 cells and 2.8, 21.8, 30.4, and 40.2% on HGF-1 cells respectively. 3. The number of G1-stage cells was abruptly decreased after 2 Gy irradiation on KB cells and 10 Gy irradiation on RPMI 2650 cells, But there was a slight decrease without regard to irradiation dose on HGF-1 cells. 4. There was no significantly different absorbance in extracellular LDH assay along the experimental cell lines

  13. Transformation of UV-hypersensitive Chinese hamster ovary cell mutants with UV-irradiated plasmids

    International Nuclear Information System (INIS)

    Nairn, R.S.; Humphrey, R.M.; Adair, G.M.

    1988-01-01

    Transfection of UV-hypersensitive, DNA repair-deficient Chinese hamster ovary (CHO) cell lines and parental, repair-proficient CHO cells with UV-irradiated pHaprt-1 or pSV2gpt plasmids resulted in different responses by recipient cell lines to UV damage in transfected DNA. Unlike results reported for human cells, UV irradiation of transfecting DNA did not stimulate genetic transformation of CHO recipient cells. In repair-deficient CHO cells, proportionally fewer transformants were produced with increasing UV damage than in repair-proficient cells in transfections with UV-irradiated hamster adenine phosphoribosyltransferase (APRT) gene contained in plasmid pHaprt-1. Transfection of CHO cells with UV-irradiated pSV2gpt resulted in neither decline in transformation frequencies in repair-deficient cell lines relative to repair-proficient cells nor stimulation of genetic transformation by UV damage in the plasmid. Blot hybridization analysis of DNA samples isolated from transformed cells showed no dramatic changes in copy number or arrangement of transfected plasmid DNA with increasing UV dose. The authors conclude responses of recipient cells to UV-damaged transfecting plasmids depend on type of recipient cell and characteristics of the genetic sequence used for transfection. (author)

  14. Low- and high-dose laser irradiation effects on cell migration and destruction

    Science.gov (United States)

    Layton, Elivia; Gallagher, Kyra A.; Zukerman, Sara; Stevens, Brianna; Zhou, Feifan; Liu, Hong; Chen, Wei R.

    2018-02-01

    Metastases are the cause of more than 90 percent of cancer-related deaths. Current treatment methods, including chemotherapy, radiation, and surgery, fail to target the metastases effectively. One potential treatment for metastatic cancer is laser immunotherapy (LIT). LIT combines the use of a photothermal laser with an immunoadjuvant, Glycated Chitosan (GC). GC combined with single-walled carbon nanotubes (SWNTs) has proven to be a viable alternative to traditional cancer treatment methods, when under irradiation of laser with appropriate wavelength. In this study, the effects of low dose and high dose laser irradiation on metastatic pancreatic cancer cell migration were observed. It was found that low dose irradiation increased the migration rate, but the high dose irradiation significantly decreased the migration rate of the cancer cells. When using LIT, the goal is to kill tumor cells and to prompt the correct immune response. If the tumor were irradiated with a low dose, it would promote metastasis. If the dose of irradiation were too high, it would destroy the entire tumor and the immune response would not recognize the tumor. Therefore, the laser dose plays an important role in LIT, particularly when using SWNT as light absorbing agent. Our results from this study will delineate the optimal laser irradiation dose for destroying tumor cells and at the same time preserve and release tumor antigens as a precursor of antitumor immune response.

  15. Responses of vibrissa-sensitive cortical neurons in normal and prenatally x-irradiated rat

    International Nuclear Information System (INIS)

    Ito, M.; Kawabata, M.; Shoji, R.

    1979-01-01

    Rats were irradiated by 200 R of x ray on day 17 of gestation through the body wall of the mother. When they underwent the following electrophysiological tests at the age of 3 to 4 month, the somatosensory cortex showed a lack of layers II, III, IV, and Va. Spike responses to quick whisker deflections were recorded from single cells in the somatosenory cortex of normal and prenatally x-irradiated rats. For the irradiated rats the response latency was prolonged when compared to the normal controls. Cortical laminar analysis of field potentials revealed that there was no difference in the latency of these potentials between the two groups, suggesting that vibrissal sensory signals reach the cortical level normally even in the irradiated rats. The prolonged latency of the irradiated cortical neuronal response could thus be ascribed to an abnormal intracortical delay, which was most likely associated with the failure of development of layer IV stellate cells in these preparations

  16. The regulation of ras-raf signaling pathway on G1 phase of the irradiated cells

    International Nuclear Information System (INIS)

    Guo Dehuang; Dong Bo; Liu Nongle; Wen Gengyun; Luo Qingliang; Mao Bingzhi

    2000-01-01

    Objective: To investigate the way of ras-raf signaling pathway which regulate the G 1 phase in irradiated KG-1 cells. Methods: Blocked the GM-CSF signaling pathway by transfected DN-ras and then momentary transfected cyclin D1 into irradiated KG-1 cells, the effects of cyclin D1 on G 1 phase was examined. Results: The irradiated KG-1 cells transfected DN-ras can't recover form G 1 phase arrest even though the GM-CSF was given,momentary transfected cyclin D1 promote the irradiated KG-1 cells from G 1 arrest. Conclusion: Activation of ras-raf signaling pathway regulate the cell cycle of the irradiated KG-1 cells through promotion the expression of the cyclin D1

  17. Reactivation of X-irradiated cell material during limb regeneration in Urodeles Amphibians

    International Nuclear Information System (INIS)

    Desselle, J.C.

    1979-10-01

    In amputated members irradiated with X-rays the regeneration power is inhibited. This power is restored by grafts of healthy tissue in the irradiated members. The origin of the cell material of the restored regeneration blastema has been studied by an original labelling technique. The different amounts of DNA in the graft cells and those of the stump mark the graft cells during the regeneration process. It was shown that the graft causes a reactivation of the inhibited stump cells and the reactivation stages are the same as the activation stages of the member regenerating normally. It was also established that during restored regeneration the cell material implanted in the irradiated members contributes, by the 160th day of regeneration, 4.5% of the cartilaginous regenerate cells and 12% of the muscle cells. All the other regenerate cells are supplied by the cells of the stump; these are reactivated and together with the activated graft cells lead to the restitution of the amputated member [fr

  18. The crosstalk between α-irradiated Beas-2B cells and its bystander U937 cells through MAPK and NF-κB signaling pathways

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Jiamei; Yuan, Dexiao; Xiao, Linlin; Tu, Wenzhi; Dong, Chen; Liu, Weili; Shao, Chunlin, E-mail: clshao@shmu.edu.cn

    2016-01-15

    Highlights: • α-irradiated Beas-2B cells induced bystander effects in macrophage U937 cells. • The neighboring macrophages enhanced the damage of α-irradiated Beas-2B cells. • MAPK and NF-κB pathways were activated in U937 cells after cell co-culture. • NF-κB and MAPK pathways participated in the bilateral bystander responses. - Abstract: Although accumulated evidence suggests that α-particle irradiation induced bystander effect may relevant to lung injury and cancer risk assessment, the exact mechanisms are not yet elucidated. In the present study, a cell co-culture system was used to investigate the interaction between α-particle irradiated human bronchial epithelial cells (Beas-2B) and its bystander macrophage U937 cells. It was found that the cell co-culture amplified the detrimental effects of α-irradiation including cell viability decrease and apoptosis promotion on both irradiated cells and bystander cells in a feedback loop which was closely relevant to the activation of MAPK and NF-κB pathways in the bystander U937 cells. When these two pathways in U937 cells were disturbed by special pharmacological inhibitors before cell co-culture, it was found that a NF-κB inhibitor of BAY 11-7082 further enhanced the proliferation inhibition and apoptosis induction in bystander U937 cells, but MAPK inhibitors of SP600125 and SB203580 protected cells from viability loss and apoptosis and U0126 presented more beneficial effect on cell protection. For α-irradiated epithelial cells, the activation of NF-κB and MAPK pathways in U937 cells participated in detrimental cellular responses since the above inhibitors could largely attenuate cell viability loss and apoptosis of irradiated cells. Our results demonstrated that there are bilateral bystander responses between irradiated lung epithelial cells and macrophages through MAPK and NF-κB signaling pathways, which accounts for the enhancement of α-irradiation induced damage.

  19. The crosstalk between α-irradiated Beas-2B cells and its bystander U937 cells through MAPK and NF-κB signaling pathways

    International Nuclear Information System (INIS)

    Fu, Jiamei; Yuan, Dexiao; Xiao, Linlin; Tu, Wenzhi; Dong, Chen; Liu, Weili; Shao, Chunlin

    2016-01-01

    Highlights: • α-irradiated Beas-2B cells induced bystander effects in macrophage U937 cells. • The neighboring macrophages enhanced the damage of α-irradiated Beas-2B cells. • MAPK and NF-κB pathways were activated in U937 cells after cell co-culture. • NF-κB and MAPK pathways participated in the bilateral bystander responses. - Abstract: Although accumulated evidence suggests that α-particle irradiation induced bystander effect may relevant to lung injury and cancer risk assessment, the exact mechanisms are not yet elucidated. In the present study, a cell co-culture system was used to investigate the interaction between α-particle irradiated human bronchial epithelial cells (Beas-2B) and its bystander macrophage U937 cells. It was found that the cell co-culture amplified the detrimental effects of α-irradiation including cell viability decrease and apoptosis promotion on both irradiated cells and bystander cells in a feedback loop which was closely relevant to the activation of MAPK and NF-κB pathways in the bystander U937 cells. When these two pathways in U937 cells were disturbed by special pharmacological inhibitors before cell co-culture, it was found that a NF-κB inhibitor of BAY 11-7082 further enhanced the proliferation inhibition and apoptosis induction in bystander U937 cells, but MAPK inhibitors of SP600125 and SB203580 protected cells from viability loss and apoptosis and U0126 presented more beneficial effect on cell protection. For α-irradiated epithelial cells, the activation of NF-κB and MAPK pathways in U937 cells participated in detrimental cellular responses since the above inhibitors could largely attenuate cell viability loss and apoptosis of irradiated cells. Our results demonstrated that there are bilateral bystander responses between irradiated lung epithelial cells and macrophages through MAPK and NF-κB signaling pathways, which accounts for the enhancement of α-irradiation induced damage.

  20. Depression of pyrimidine dimer excision from the aspects of uv reversibility of irradiated cells

    Energy Technology Data Exchange (ETDEWEB)

    Slamenova, D; Slezarikova, V; Masek, F [Slovenska Akademia Vied, Bratislava (Czechoslovakia)

    1977-04-01

    Depression of pyrimidine dimer excision induced in uv-irradiated E.coli B/r T/sup -/trp/sup -/Hcr/sup +/ cells by preirradiation cultivation in conditions of starving for the essential amino acid and thymine does not increase uv-reversibility of irradiated cells and does not influence the time of expression of trp/sup +/ reversions. The expression of mutations becomes completed in control and prestarved cells prior to restoration of postradiation division. Genetic deficiency leads up to their high sensitivity to the mutagenic activity of uv irradiation. Expression of trp/sup +/ revertants in Hcr/sup -/ type cells does not become completed until after commencement of the postradiation division of irradiated cells. Prestarved E.coli B/r T/sup -/trp/sup -/Hcr/sup +/ cells exhibited depression of excision even with postradiation cultivation in the absence of an essential amino acid, which is associated with greater stability of newly synthesized DNA and overall decrease of the death rate of cells. In postradiation starvation for the essential amino acid E.coli B/r T/sup -/trp/sup -/Hcr/sup -/ cells irradiated with low uv light doses behaved similarly. Control E.coli B/r T/sup -/trp/sup -/Hcr/sup +/ cells, cultivated after irradiation without amino acid, excised pyrimidine dimers; they are characterised by high degradation of newly synthesized DNA and increased death rate of cells.

  1. Cell survival in spheroids irradiated with heavy-ion beams

    International Nuclear Information System (INIS)

    Rodriguez, A.; Alpen, E.L.

    1981-01-01

    Biological investigations with accelerated heavy ions have been carried out regularly at the Lawrence Berkeley Laboratory Bevalac for the past four years. Most of the cellular investigations have been conducted on cell monolayer and suspension culture systems. The studies to date suggest that heavy charged particle beams may offer some radiotherapeutic advantages over conventional radiotherapy sources. The advantages are thought to lie primarily in an increased relative biological effectiveness (RBE), a decrease in the oxygen enhancement ratio (OER), and better tissue distribution dose. Experiments reported here were conducted with 400 MeV/amu carbon ions and 425 MeV/amu neon ions, using a rat brain gliosarcoma cell line grown as multicellular spheroids. Studies have been carried out with x-rays and high-energy carbon and neon ion beams. These studies evaluate high-LET (linear energy transfer) cell survival in terms of RBE and the possible contributions of intercellular communication. Comparisons were made of the post-irradiation survival characteristics for cells irradiated as multicellular spheroids (approximately 100 μm and 300 μm diameters) and for cells irradiated in suspension. These comparisons were made between 225-kVp x-rays, 400 MeV/amu carbon ions, and 425 MeV/amu neon ions

  2. Extracorporeal irradiation of dog blood: the effects of a radiostrontium irradiator on blood stem cells (CFU-C)

    Energy Technology Data Exchange (ETDEWEB)

    Szemere, P.; Fliedner, T.M.; Nothdurft, W.; Breitig, D.

    1982-07-01

    The radiation sensitivity of dog blood stem cells was measured in vitro and in an extracorporeal circulation passing through a radiation field. It was established that the calculated D/sub 0/ was as low as 0.45 Gy. Investigating the cell killing rate in our equipment (Buchler type /sup 90/Sr device for extracorporeal irradiation), we found an overkill situation; the dose delivered was in excess of that which would be required for the total eradication of all stem cells in the peripheral blood passing through the radiation field. Various other types of devices used for extracorporeal irradiation of blood are also reviewed.

  3. Influence of catechins on bystander responses in CHO cells induced by alpha-particle irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Law, Y.L.; Wong, T.P.W. [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong (Hong Kong); Yu, K.N. [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong (Hong Kong)], E-mail: peter.yu@cityu.edu.hk

    2010-04-15

    In this work, we studied alpha-particle induced and medium-mediated bystander effects in Chinese hamster ovary (CHO) cells through micronucleus (MN) assay. We showed that signal transduction from irradiated cells to bystander cells occur within a short time after irradiation. We then studied the effects of ROS (reactive oxygen species)-scavenging catechins in the medium before irradiation. We observed decreases in the percentage of bystander cells with MN formation and thus proved the protection effect of catechins on bystander cells from radiation.

  4. Response of stem cell system to whole body and partial body irradiation

    International Nuclear Information System (INIS)

    Gidali, J.

    1975-01-01

    The pluripotent stem cell system, though being distributed in the body, reacts homogeneously to irradiation. This homogeneity is controlled by short-range (local) and long-range (humoral) regulations acting primarily on pluripotent and committed stem cells. Migration of stem cells from unirradiated to irradiated areas may play a role in the regeneration processes even if local regeneration may also occur. Migration induction as well as proliferation induction in the shielded area do not seem to be specific radiation-induced reactions. Both may be influenced either by some physiological regulators released after irradiation in a higher quantity or by some non-specific triggering agents. Both repeated and continuous irradiation induce the establishment of a new steady state. In the steady state after repeated sublethal irradiations, the CFU count stays at a suboptimal level either as a consequence of an increased differentiation or of some undefined damage in milieu control. In the new steady state during continuous irradiation, the number of mature elements in blood is close to the normal while CFU population is reduced to less than 2 percent of its original level

  5. Low-level laser irradiation induces in vitro proliferation of mesenchymal stem cells

    International Nuclear Information System (INIS)

    Barboza, Carlos Augusto Galvão; Ginani, Fernanda; Soares, Diego Moura; Henriques, Águida Cristina Gomes; Freitas, Roseana de Almeida

    2014-01-01

    To evaluate the effect of low-level laser irradiation on the proliferation and possible nuclear morphological changes of mouse mesenchymal stem cells. Mesenchymal stem cells derived from bone marrow and adipose tissue were submitted to two applications (T0 and T48 hours) of low-level laser irradiation (660nm; doses of 0.5 and 1.0J/cm"2). The trypan blue assay was used to evaluate cell viability, and growth curves were used to analyze proliferation at zero, 24, 48, and 72 hours. Nuclear alterations were evaluated by staining with DAPI (4'-6-diamidino-2-phenylindole) at 72 hours. Bone marrow-derived mesenchymal stem cells responded to laser therapy in a dose-dependent manner. Higher cell growth was observed when the cells were irradiated with a dose of 1.0J/cm"2, especially after 24 hours (p<0.01). Adipose-derived mesenchymal stem cells responded better to a dose of 1.0J/cm"2, but higher cell proliferation was observed after 48 hours (p<0.05) and 72 hours (p<0.01). Neither nuclear alterations nor a significant change in cell viability was detected in the studied groups. Low-level laser irradiation stimulated the proliferation of mouse mesenchymal stem cells without causing nuclear alterations. The biostimulation of mesenchymal stem cells using laser therapy might be an important tool for regenerative therapy and tissue engineering

  6. RNA and protein synthesis of irradiated Ehrlich ascites tumour cells. Pt. 1

    International Nuclear Information System (INIS)

    Skog, S.; Tribukait, B.; Sundius, G.

    1985-01-01

    The effects of roentgen irradiation on the incorporation of 3 H-uridine and 14 C-leucine into RNA and protein and the RNA and protein contents of in vivo growing Ehrlich ascites tumour cells were studied. The results were related to changes in the composition of cells in cell cycle and compared with the synthesis of RNA and protein in cell material from various parts of the cell cycle obtained by means of elutriator centrifuging. The incorporation expressed by the ratio between acid insoluble/acid soluble activity was unchanged for RNA during the observation period up to 24 hours after a dose of 5.0 Gy. The ratio for protein was markedly decreased between 4 and 24 hours. This decrease was partly due to a decrease of the pool size of leucine as studied by changing the amounts of 14 C leucine used. From these studies, the existence of at least two pools, an expandable and a non-expandable fixed pool can be concluded. There were no differences in the decrease of protein-synthesis between cells from the various parts of the cell cycle. The RNA and protein contents of the irradiated cells from various parts of the cell cycle corresponded to those of non-irradiated cells except for G 1 /early S-phase cells at 15 and 24 hours after irradiation. Possible reasons for this discrepancy are discussed. (orig.)

  7. Studies of Bystander Effect and Intercellular Communication in Human Epithelial Cell Cultures Irradiated with X-rays

    International Nuclear Information System (INIS)

    Romppanen, E.; Trott, K. R.; Musatonen, R.; Leszcznski, D.; Belyakov, O.

    2004-01-01

    The bystander effect is a phenomenon whereby biological consequences of irradiation are expressed in nonexposed cells in the vicinity of exposed cells. Two main pathways have been proposed to mediate the bystander effect: Gap Junction Intercellular Communication (GJIC) and medium borne soluble factors dependent mechanisms. The present study was designed to evaluate the relative contributions of gap junction intercellular communication and of soluble extracellular factors on the bystander effects of low dose X-ray irradiation. HaCaT human epithelial cell monolayers were exposed to X-ray using specially constructed shield, which cover 95% or 56% or 0% of the cells from the radiation. To evaluate whether the GJIC is involved in transmission of the bystander signal from irradiated to nonirradiated cells, irradiations were performed in presence or absence of GJIC inhibitor lindane. The cytochalasin B block technique was used to quantify fractions of micronucleated cells 48 hours after the irradiation. Our results suggest that more micronucleated cells are induced in partially shielded monolayers than expected according to back extrapolation of the data from open field irradiation. Treatment with lindane considerably reduced amount of the bystander damage. We demonstrated that fraction of micronucleated cells after X-rays irradiation of 5% of cells with 1 Gy was 0.07±0.08 (without lindane) and 0.05±0.004 (in presence of lindane). Irradiation of 100% of cells with the same dose resulted in 0.023±0.04 /without lindane) and 0.013±0.02 (in presence of lindane) fractions of micronucleated cells. Comparison with open field data showed that the fraction of micronucleated cells after irradiation of 5% of the cell culture was 5-10 times greater than the estimated fraction assuming no bystander effect. Irradiation of 44% of cells ded not demonstrate a pronounced bystander effect. (Author) 20 refs

  8. The influence of fractionation on cell survival and premature differentiation after carbon ion irradiation

    International Nuclear Information System (INIS)

    Wang Jufang; Li Renming; Guo Chuanling; Fournier, C.; K-Weyrather, W.

    2008-01-01

    To investigate the influence of fractionation on cell survival and radiation induced premature differentiation as markers for early and late effects after X-rays and carbon irradiation. Normal human fibroblasts NHDF, AG1522B and WI-38 were irradiated with 250 kV X-rays, or 266 MeV/u, 195 MeV/u and 11 MeV/u carbon ions. Cytotoxicity was measured by a clonogenic survival assay or by determination of the differentiation pattern. Experiments with high-energy carbon ions show that fractionation induced repair effects are similar to photon irradiation. The relative biological effective (RBE) 10 values for clonogenic survival are 1.3 and 1.6 for irradiation in one or two fractions for NHDF cells and around 1.2 for AG1522B cells regardless of the fractionation scheme. The RBE for a doubling of post mitotic fibroblasts (PMF) in the population is 1 for both single and two fractionated irradiation of NHDF cells. Using 11 MeV/u carbon ions, no repair effect can be seen in WI-38 cells. The RBE 10 for clonogenic survival is 3.2 for single irradiation and 4.9 for two fractionated irradiations. The RBE for a doubling of PMF is 3.1 and 5.0 for single and two fractionated irradiations, respectively. For both cell lines the effects of high-energy carbon ions representing the irradiation of the skin and the normal tissue in the entrance channel are similar to the effects of X-rays. The fractionation effects are maintained. For the lower energy, which is representative for the irradiation of the tumor region, RBE is enhanced for clonogenic survival as well as for premature terminal differentiation. Fractionation effects are not detectable. Consequently, the therapeutic ratio is significantly enhanced by fractionated irradiation with carbon ions. (author)

  9. DNA synthesis and cell survival after X-irradiation of mammalian cells treated with caffeine or adenine

    International Nuclear Information System (INIS)

    Griffiths, T.D.; Carpenter, J.G.; Dahle, D.B.

    1978-01-01

    The expression of the transient depression in the rate of DNA synthesis normally observed after exposure of randomly-dividing Chinese hamster V-79 or Chinese hamster CHO cells to ionizing radiation could be postponed by a post-irradiation treatment with 1.0 to 2.0 mM adenine or 1.5 mM caffeine. Caffeine may exert its effect by creating additional sites for replication in irradiated cells. Cells treated with caffeine or adenine for 2 or 4 hours after exposure to 3000 rad of 300 kVp X-rays exhibited depressed synthesis only after the removal of caffeine or adenine. These alterations in the timing of the X-ray-induced depression of the rate of DNA synthesis had no effect on X-ray-induced cell killing. Although a 4 hour post-irradiation treatment of randomly-dividing Chinese hamster V-79 cells with 1.0 or 2.0 mM caffeine potentiated X-ray-induced cell killing, this reduction in survival was due primarily to effects on cells not in S-phase. (author)

  10. Effects of cytokine combinations on the cell cycle and early apoptosis of irradiated umbilical cord blood AC133+ cells

    International Nuclear Information System (INIS)

    Liu Yulong; Dai Hong; Jiang Zhong; Zhou Liying; Guo Xiaokui; Zhou Jianying

    2005-01-01

    The cell cycle and early apoptosis of 2.5 Gy 6 MV-X ray irradiated umbilical cord blood AC133 + cells cultured with cytokine combinations (IL-3 + FL + SCF) were immunolabelled and analyzed by flow cytometry at d 0, 1, 2, 3 and 7. The result of flow cytometry analysis showed that majority of irradiated umbilical cord blood AC133 + cells were in G 0 /G 1 phase of the cell cycle at d 0. Under the influence of cytokine combinations (IL-3 + FL + SCF), nearly 50% of cells were in S phase on 3rd day. AC133 + cells irradiated were in vitro incubated in the medium without cytokines, nearly all cells died by apoptosis. However, when we incubated cells with cytokine combinations (IL-3 + FL + SCF), (38.0 ± 6.8)% of cells were saved from apoptosis at d 2. The more percent of saved AC133 + cells became to proliferate with the extension of culture. In short, cytokine combinations (IL-3 + FL + SCF) could have a key role to protect irradiated cells and partially avoid induction of apoptosis by ionizing radiation in hematopoietics stem/progenitor cells. (authors)

  11. Irradiated KHYG-1 retains cytotoxicity: potential for adoptive immunotherapy with a natural killer cell line.

    Science.gov (United States)

    Suck, G; Branch, D R; Keating, A

    2006-05-01

    To evaluate gamma-irradiation on KHYG-1, a highly cytotoxic natural killer (NK) cell line and potential candidate for cancer immunotherapy. The NK cell line KHYG-1 was irradiated at 1 gray (Gy) to 50 Gy with gamma-irradiation, and evaluated for cell proliferation, cell survival, and cytotoxicity against tumor targets. We showed that a dose of at least 10 Gy was sufficient to inhibit proliferation of KHYG-1 within the first day but not its cytolytic activity. While 50 Gy had an apoptotic effect in the first hours after irradiation, the killing of K562 and HL60 targets was not different from non-irradiated cells but was reduced for the Ph + myeloid leukemia lines, EM-2 and EM-3. gamma-irradiation (at least 10 Gy) of KHYG-1 inhibits cell proliferation but does not diminish its enhanced cytolytic activity against several tumor targets. This study suggests that KHYG-1 may be a feasible immunotherapeutic agent in the treatment of cancers.

  12. Changes in distribution of cell cycle phases and DNA content in HeLa S3 cell after irradiation

    International Nuclear Information System (INIS)

    Wang Shunbao

    1992-01-01

    The effects of irradiation and hyperthermia on the distribution in various phases and DNA content of HeLa S 3 cells were analyzed by flow cytometry and an image analysis instrument. A marked increase in DNA content from 6.718 to 9.614(AU) in HeLa S 3 cells after 6 Gy irradiation was seen to correspond with the changes in the distribution of various phases in G 2 + M, from 22% to 52%. Meanwhile, the surviving fraction of HeLa S 3 cells after 6 Gy irradiation was less than 1%. However, after heating at 44 deg C for 10 min, the amount of cells in G 2 + M increased from 22.5% to 52.5% and the surviving fraction after hyperthermia was less than 2.65%. The changes in distribution of various phases after Ir-192 irradiation were similar to those seen after X-ray irradiation. The delay of G 2 + M phase after treatment with 8 Gy plus heating at 44 deg C for 7 min in HeLa S 3 cells was similar to that seen in the case of treatment with 8 Gy alone. As the surviving fraction accompanying the G 2 + M delay after irradiation plus heat treatment was very low, we suggest that the changes of distribution in various phases of HeLa S 3 cells after treatment might be used as a rapid indicator of serious injury

  13. Apoptosis of nasopharyngeal carcinoma cell line (CNE-2) induced by neutron irradiation

    International Nuclear Information System (INIS)

    Liang Ke; He Shaoqin; Feng Yan; Tang Jinhua; Feng Qinfu; Shen Yu; Yin Weibo; Xu Guozhen; Liu Xinfan; Wang Luhua; Gao Li

    1999-01-01

    Objective: To study the apoptotic response of the nasopharyngeal carcinoma cell line (CNE-2) induced by neutron irradiation. Methods: CNE-2 cells were cultured as usual. Using the techniques of DNA agarose gel electrophoresis and DNA special fluorescent staining, the status of apoptosis in CNE-2 cells after neutron irradiation was detected. Results: It was shown that the apoptosis can be induced in CNE-2 cell after neutron radiation. Six hrs, after different doses of neutron (0/0.667/1.333/2.000/2.667/3.333 Gy) and X-ray 0/2/4/6/8/10 Gy) irradiation the apoptotic rates were 2.4%, 6.3%, 7.1%, 9.5%, 13.5%, 14.6% and 2.4%, 3.8%, 5.7%, 7.8%, 10.4%, 11.7%, respectively; at 48 hrs they were 18.3%, 21.5%, 22.8%, 29.3%, 34.2% and 13.7%, 17.6%, 21.3%, 25.6%, 28.9%, respectively. At 10 hrs after neutron irradiation the DNA ladder of apoptosis could be detected between 0.667-3.333 Gy doses in CNE-2 cells by DNA agarose gel electrophoresis. Conclusion: Neutron radiation can induce apoptosis in tumor cells. Compared with the X-ray, neutron induces apoptosis in larger extent than X-ray in the same condition; meanwhile, apoptosis after irradiation is dose and time dependent

  14. Interaction between thymic cells and hemopoietic stem cells. Enhanced repopulation of the irradiated thymus

    International Nuclear Information System (INIS)

    Daculsi, Richard; Legrand, Elisabeth; Duplan, J.-F.

    1977-01-01

    In irradiated mice engrafted with hemopoietic cells, the thymus is repopulated more rapidly by bone marrow-derived than by spleen-derived cells. Admixing thymic cells with restorative suspension stimulates the thymic repopulation by spleen-derived cells whereas it has no effect on the repopulation by bone marrow-derived cells [fr

  15. Effect of Irradiation on Apoptosis, Cell Cycle Arrest and Calcified Nodule Formation of Rat Calvarial Osteoblast

    International Nuclear Information System (INIS)

    Lee, Young Mi; Choi, Hang Moon; Heo, Min Suk; Lee, Sam Sun; Choi, Soon Chul; Park, Tae Won

    2000-01-01

    The study was aimed to detect the induction of apoptosis, cell cycle arrest and calcified nodule formation after irradiation on primarily cultured osteoblasts. Using rat calvarial osteoblasts, the effects of irradiation on apoptosis, cell cycle arrest, and calcified nodule formation were studied. The single irradiation of 10, 20 Gy was done with 5.38 Gy/min dose rate using the 137 Cs cell irradiator at 4th and 14th day of culture. Apoptosis induction and cell cycle arrest were assayed by the flow cytometry at 1, 2, 3, and 4 days after irradiation. The formation of calcified nodules was observed by alizarin red staining at 1, 3, 10, 14 days after irradiation at 4th day of culture, and at 1, 4, 5 days after irradiation at 14th day of culture. Apoptosis was not induced by 10 or 20 Gy independent of irradiation and culture period. Irradiation did not induced G1 arrest in post-irradiated osteoblasts. After irradiation at 4th-day of culture, G2 arrest was induced but it was not statistically significant after irradiation at 14th-day of culture. In the case of irradiated cells at 4th day of culture, calcified nodules were not formed and at 14th-day of culture after irradiation, calcified nodule formation did not affected. Taken together, these results suggest that irradiation at the dose of 10-20 Gy would not affect apoptosis induction of osteoblasts. Cell cycle and calcified nodule formation were influenced by the level of differentiation of osteblasts.

  16. Spermatogonial stem cell renewal following irradiation

    International Nuclear Information System (INIS)

    Fabrikant, J.I.

    1979-05-01

    The spermatogonial cell renewal system can maintain function and a steady level of cell population for relatively long periods of continuous low-level irradiation indicating that there does not appear to be a serious accumulation, over many generations, of damage affecting proliferation. Provided the dose-rate is quite low, there is an effective selective removal of damaged cells with almost complete repair of cellular nonlethal damage. At dose-rates greater than 2 rad/day, spermatogonia are very sensitive to radiation death, and the main reason for the low tolerance to continuous stress could, in part, be the limited extent of compensatory mechanisms regulating spermatogonial cell production. However, there is some capacity to change the patterns of cellular proliferation while still remaining under homeostatic control, and this capacity appears to reside in the relatively radioresistant A/sub s/ stem-cell population. Little is known about the extent to which the spermatogonial cell population can repair nonlethal cellular radiation damage accumulated under continuous stress affecting the regenerative capacity of the tissue. After acute exposure, a minimum number of surviving type A/sub s/ stem-cells are required to repopulate the functional seminiferous epithelium, regeneration proceeds along an ordered cell stage sequence, and is dependent on the time required for all stages from type A/sub s/ spermatogonia to mature spermatozoa. Under continuous irradiation, provided the dose-rate is not too high, the repopulating ability of the seminiferous epithelium is maintained, in the presence of injury, due to initial repair and long-term repair of cellular radiation damage. There is evidence for initial repair, since a dose-rate effect exists in type A survival, at low doses. Long-term repair occurs due to differential radiosensitivities of spermatogonia

  17. Effects of X-irradiation on glial cells in the developing rat brain

    International Nuclear Information System (INIS)

    Ferrer, I.; Borras, D.

    1994-01-01

    Sprague-Dawley rats were given a single dose of 2Gy X-rays when 1 or 3 days of age. Dying cells in the germinal layer of the telencephalon reached peak values 6h after irradiation; dead cells were cleared 48h later. These effects were almost abolished with the injection of cyclohexamide (1 μg/g body weight) given at the time of irradiation. PCNA-immunoreactive cells (cells in late G 1 and S phases of the cell cycle) and PCNA-negative cells were sensitive to X-rays. Long-term effects on glial cell populations in the subcortical white matter of the cingulum were examined in irradiated rats, killed at postnatal day 30 (P30), by means of glial fibrillary acidic protein, vimentin and S-100 immunohistochemistry, as well as with anti-TGF-α (transformerly growth factor) antibodies that are used as putative oligodendrogial cell markers in the white matter of rat. (author)

  18. Damaging and protective bystander cross-talk between human lung cancer and normal cells after proton microbeam irradiation

    International Nuclear Information System (INIS)

    Desai, Sejal; Kobayashi, Alisa; Konishi, Teruaki; Oikawa, Masakazu; Pandey, Badri N.

    2014-01-01

    Graphical abstract: - Highlights: • Proton-microbeam irradiated A549 cells send damaging signals to bystander A549 cells. • Irradiated A549–A549 bystander response is through gap junctional communication. • Bystander WI38 cells exert protective signalling in irradiated A549 cells. • Rescue of irradiated A549 cells by WI38 cells is independent of gap junctions. - Abstract: Most of the studies of radiation-induced bystander effects (RIBE) have been focused on understanding the radiobiological changes observed in bystander cells in response to the signals from irradiated cells in a normal cell population with implications to radiation risk assessment. However, reports on RIBE with relevance to cancer radiotherapy especially investigating the bidirectional and criss-cross bystander communications between cancer and normal cells are limited. Hence, in present study employing co-culture approach, we have investigated the bystander cross-talk between lung cancer (A549) and normal (WI38) cells after proton-microbeam irradiation using γ-H2AX foci fluorescence as a measure of DNA double-strand breaks (DSBs). We observed that in A549–A549 co-cultures, irradiated A549 cells exert damaging effects in bystander A549 cells, which were found to be mediated through gap junctional intercellular communication (GJIC). However, in A549–WI38 co-cultures, irradiated A549 did not affect bystander WI38 cells. Rather, bystander WI38 cells induced inverse protective signalling (rescue effect) in irradiated A549 cells, which was independent of GJIC. On the other hand, in response to irradiated WI38 cells neither of the bystander cells (A549 or WI38) showed significant increase in γ-H2AX foci. The observed bystander signalling between tumour and normal cells may have potential implications in therapeutic outcome of cancer radiotherapy

  19. Damaging and protective bystander cross-talk between human lung cancer and normal cells after proton microbeam irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Desai, Sejal [Radiation Signalling and Cancer Biology Section, Radiation Biology and Health Sciences Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Kobayashi, Alisa; Konishi, Teruaki; Oikawa, Masakazu [Radiation System and Engineering Section, Department of Technical Support and Development, Research, Development and Support Center, National Institute of Radiological Sciences, Chiba 263-8555 (Japan); Pandey, Badri N., E-mail: badrinarain@yahoo.co.in [Radiation Signalling and Cancer Biology Section, Radiation Biology and Health Sciences Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India)

    2014-05-15

    Graphical abstract: - Highlights: • Proton-microbeam irradiated A549 cells send damaging signals to bystander A549 cells. • Irradiated A549–A549 bystander response is through gap junctional communication. • Bystander WI38 cells exert protective signalling in irradiated A549 cells. • Rescue of irradiated A549 cells by WI38 cells is independent of gap junctions. - Abstract: Most of the studies of radiation-induced bystander effects (RIBE) have been focused on understanding the radiobiological changes observed in bystander cells in response to the signals from irradiated cells in a normal cell population with implications to radiation risk assessment. However, reports on RIBE with relevance to cancer radiotherapy especially investigating the bidirectional and criss-cross bystander communications between cancer and normal cells are limited. Hence, in present study employing co-culture approach, we have investigated the bystander cross-talk between lung cancer (A549) and normal (WI38) cells after proton-microbeam irradiation using γ-H2AX foci fluorescence as a measure of DNA double-strand breaks (DSBs). We observed that in A549–A549 co-cultures, irradiated A549 cells exert damaging effects in bystander A549 cells, which were found to be mediated through gap junctional intercellular communication (GJIC). However, in A549–WI38 co-cultures, irradiated A549 did not affect bystander WI38 cells. Rather, bystander WI38 cells induced inverse protective signalling (rescue effect) in irradiated A549 cells, which was independent of GJIC. On the other hand, in response to irradiated WI38 cells neither of the bystander cells (A549 or WI38) showed significant increase in γ-H2AX foci. The observed bystander signalling between tumour and normal cells may have potential implications in therapeutic outcome of cancer radiotherapy.

  20. Salisphere derived c-Kit+ cell transplantation restores tissue homeostasis in irradiated salivary gland

    International Nuclear Information System (INIS)

    Nanduri, Lalitha S.Y.; Lombaert, Isabelle M.A.; Zwaag, Marianne van der; Faber, Hette; Brunsting, Jeanette F.; Os, Ronald P. van; Coppes, Robert P.

    2013-01-01

    Introduction: During radiotherapy salivary glands of head and neck cancer patients are unavoidably co-irradiated, potentially resulting in life-long impairment. Recently we showed that transplantation of salisphere-derived c-Kit expressing cells can functionally regenerate irradiated salivary glands. This study aims to select a more potent subpopulation of c-Kit + cells, co-expressing stem cell markers and to investigate whether long-term tissue homeostasis is restored after stem cell transplantation. Methods and results: Salisphere derived c-Kit + cells that co-expressed CD24 and/or CD49f markers, were intra-glandularly injected into 15 Gy irradiated submandibular glands of mice. Particularly, c-Kit + /CD24 + /CD49f + cell transplanted mice improved saliva production (54.59 ± 11.1%) versus the irradiated control group (21.5 ± 8.7%). Increase in expression of cells with differentiated duct cell markers like, cytokeratins (CK8, 18, 7 and 14) indicated functional recovery of this compartment. Moreover, ductal stem cell marker expression like c-Kit, CD133, CD24 and CD49f reappeared after transplantation indicating long-term functional maintenance potential of the gland. Furthermore, a normalization of vascularization as indicated by CD31 expression and reduction of fibrosis was observed, indicative of normalization of the microenvironment. Conclusions: Our results show that stem cell transplantation not only rescues hypo-salivation, but also restores tissue homeostasis of the irradiated gland, necessary for long-term maintenance of adult tissue

  1. Beta-irradiation used for systemic radioimmunotherapy induces apoptosis and activates apoptosis pathways in leukaemia cells

    International Nuclear Information System (INIS)

    Friesen, Claudia; Lubatschofski, Annelie; Debatin, Klaus-Michael; Kotzerke, Joerg; Buchmann, Inga; Reske, Sven N.

    2003-01-01

    Beta-irradiation used for systemic radioimmunotherapy (RIT) is a promising treatment approach for high-risk leukaemia and lymphoma. In bone marrow-selective radioimmunotherapy, beta-irradiation is applied using iodine-131, yttrium-90 or rhenium-188 labelled radioimmunoconjugates. However, the mechanisms by which beta-irradiation induces cell death are not understood at the molecular level. Here, we report that beta-irradiation induced apoptosis and activated apoptosis pathways in leukaemia cells depending on doses, time points and dose rates. After beta-irradiation, upregulation of CD95 ligand and CD95 receptor was detected and activation of caspases resulting in apoptosis was found. These effects were completely blocked by the broad-range caspase inhibitor zVAD-fmk. In addition, irradiation-mediated mitochondrial damage resulted in perturbation of mitochondrial membrane potential, caspase-9 activation and cytochrome c release. Bax, a death-promoting protein, was upregulated and Bcl-x L , a death-inhibiting protein, was downregulated. We also found higher apoptosis rates and earlier activation of apoptosis pathways after gamma-irradiation in comparison to beta-irradiation at the same dose rate. Furthermore, irradiation-resistant cells were cross-resistant to CD95 and CD95-resistant cells were cross-resistant to irradiation, indicating that CD95 and irradiation used, at least in part, identical effector pathways. These findings demonstrate that beta-irradiation induces apoptosis and activates apoptosis pathways in leukaemia cells using both mitochondrial and death receptor pathways. Understanding the timing, sequence and molecular pathways of beta-irradiation-mediated apoptosis may allow rational adjustment of chemo- and radiotherapeutic strategies. (orig.)

  2. UV or X-irradiation increases the cytoplasmic accumulation of rhodamine 123 in various cancer cell lines

    International Nuclear Information System (INIS)

    Dumitriu, I.E.; Beyer, T.D.; Gaipl, U.S.; Kalden, J.R.; Herrmann, M.; Roedel, F.

    2003-01-01

    Purpose: Previous studies indicated that ATP-binding cassette (ABC) membrane transporters protect against UV-induced apoptosis. We investigated the effect of UVB and X-ray irradiation on the export function of these ABC transporters in primary lymphocytes and various cancer cell lines. Material and Methods: We used rhodamine accumulation assays in various human malignant cell lines and peripheral blood lymphocytes (PBL). Cells were irradiated with up to 960 mJ/cm 2 and up to 50 Gy of UVB and X-ray, respectively. Results: We demonstrated that UVB as well as X-ray irradiation inhibit the export function of the ABC transporters in a dose-dependent fashion. For PBL, this effect did not correlate with an apoptotic phenotype. In the case of the tumor cell lines, even though the irradiation-induced inhibition of membrane transporters was accompanied by phosphatidylserine exposure, only a minority of cells had lost their mitochondrial membrane potential during the observation period. Furthermore, we demonstrated that the inhibition of membrane transporters is not a general feature of apoptosis. Conclusion: Irradiation inhibits the export function of ABC transporters. Although some of the irradiated cells undergo apoptosis following irradiation, the inhibition is an unique feature accompanying irradiation and not a general hallmark of apoptotic cell death. The inhibition of drug export by irradiation may offer new potential for reverting multidrug resistance of cancer cells. (orig.)

  3. UV or X-irradiation increases the cytoplasmic accumulation of rhodamine 123 in various cancer cell lines

    Energy Technology Data Exchange (ETDEWEB)

    Dumitriu, I.E.; Beyer, T.D.; Gaipl, U.S.; Kalden, J.R.; Herrmann, M. [Inst. for Clinical Immunology, Dept. of Medicine III, Friedrich Alexander Univ. of Erlangen-Nuremberg, Erlangen (Germany); Roedel, F. [Dept. of Radiooncology, Univ. of Erlangen-Nuremberg, Erlangen (Germany)

    2003-08-01

    Purpose: Previous studies indicated that ATP-binding cassette (ABC) membrane transporters protect against UV-induced apoptosis. We investigated the effect of UVB and X-ray irradiation on the export function of these ABC transporters in primary lymphocytes and various cancer cell lines. Material and Methods: We used rhodamine accumulation assays in various human malignant cell lines and peripheral blood lymphocytes (PBL). Cells were irradiated with up to 960 mJ/cm{sup 2} and up to 50 Gy of UVB and X-ray, respectively. Results: We demonstrated that UVB as well as X-ray irradiation inhibit the export function of the ABC transporters in a dose-dependent fashion. For PBL, this effect did not correlate with an apoptotic phenotype. In the case of the tumor cell lines, even though the irradiation-induced inhibition of membrane transporters was accompanied by phosphatidylserine exposure, only a minority of cells had lost their mitochondrial membrane potential during the observation period. Furthermore, we demonstrated that the inhibition of membrane transporters is not a general feature of apoptosis. Conclusion: Irradiation inhibits the export function of ABC transporters. Although some of the irradiated cells undergo apoptosis following irradiation, the inhibition is an unique feature accompanying irradiation and not a general hallmark of apoptotic cell death. The inhibition of drug export by irradiation may offer new potential for reverting multidrug resistance of cancer cells. (orig.)

  4. Dosimetry of irradiation models. The 96-well clonogenic assay for testing radiosensitivity of cell lines

    International Nuclear Information System (INIS)

    Kulmala, J.; Rantanen, V.; Turku Univ.; Pekkola-Heino, K.; Turku Univ.; Tuominen, J.; Grenman, R.; Turku Univ.

    1995-01-01

    Radiation experiments with cells in single cell suspension in test tubes and on 96-well plates were carried out and compared. The cells originated from cell lines established from carcinomas of the floor of the mouth and from endometrical carcinoma. Two irradiation models were constructed. Both models allowed the absorbed doses to the cells to be administered with a high accuracy in both experimental settings (better than 5.0%). These irradiation models were compared on cancer cell lines with dissimilar inherent radiation sensitivity and histologic type (UM-SCC-1 resistant, UM-SCC-14A sensitive, and UT-EC-2B highly sensitive); various radiation doses were used. The fractions of surviving cells as a function of radiation dose were compared: there was no significant difference between cells irradiated in test tubes and cells irradiated in 96-well plates. Thus, if the absorbed doses in cells suspended in a tube and in a plate were the same, the survival was similar regardless of the type of irradiation model. (orig.)

  5. Depression of pyrimidine dimer excision from the aspects of U.V. reversibility of irradiated cells

    International Nuclear Information System (INIS)

    Slamenova, D.; Slezarikova, V.; Masek, F.

    1977-01-01

    Depression of pyrimidine dimer excision induced in U.V. irradiated E.coli B/r T - trp - Hcr + cells by preirradiation cultivation in conditions of starving for the essential amino acid and thymine does not increase U.V.-reversibility of irradiated cells and does not influence the time of expression of trp + reversions. The expression of mutations becomes completed in control and prestarved cells prior to restoration of postradiation division. Genetic deficiency leads up to their high sensitivity to the mutagenic activity of U.V. irradiation. Expression of trp + revertants in Hcr - type cells does not become completed until after commencement of the postradiation division of irradiated cells. Prestarved E.coli B/r T - trp - Hcr + cells exhibited depression of excision even with postradiation cultivation in the absence of an essential amino acid, which is associated with greater stability of newly synthesized DNA and overall decrease of the death rate of cells. In postradiation starvation for the essential amino acid E.coli B/r T - trp - Hcr - cells irradiated with low U.V. light doses behaved similarly. Control E.coli B/r T - trp - Hcr + cells, cultivated after irradiation without amino acid, excised pyrimidine dimers; they are characterised by high degradation of newly synthesized DNA and increased death rate of cells. (author)

  6. The crosstalk between α-irradiated Beas-2B cells and its bystander U937 cells through MAPK and NF-κB signaling pathways.

    Science.gov (United States)

    Fu, Jiamei; Yuan, Dexiao; Xiao, Linlin; Tu, Wenzhi; Dong, Chen; Liu, Weili; Shao, Chunlin

    2016-01-01

    Although accumulated evidence suggests that α-particle irradiation induced bystander effect may relevant to lung injury and cancer risk assessment, the exact mechanisms are not yet elucidated. In the present study, a cell co-culture system was used to investigate the interaction between α-particle irradiated human bronchial epithelial cells (Beas-2B) and its bystander macrophage U937 cells. It was found that the cell co-culture amplified the detrimental effects of α-irradiation including cell viability decrease and apoptosis promotion on both irradiated cells and bystander cells in a feedback loop which was closely relevant to the activation of MAPK and NF-κB pathways in the bystander U937 cells. When these two pathways in U937 cells were disturbed by special pharmacological inhibitors before cell co-culture, it was found that a NF-κB inhibitor of BAY 11-7082 further enhanced the proliferation inhibition and apoptosis induction in bystander U937 cells, but MAPK inhibitors of SP600125 and SB203580 protected cells from viability loss and apoptosis and U0126 presented more beneficial effect on cell protection. For α-irradiated epithelial cells, the activation of NF-κB and MAPK pathways in U937 cells participated in detrimental cellular responses since the above inhibitors could largely attenuate cell viability loss and apoptosis of irradiated cells. Our results demonstrated that there are bilateral bystander responses between irradiated lung epithelial cells and macrophages through MAPK and NF-κB signaling pathways, which accounts for the enhancement of α-irradiation induced damage. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Effect of UV C irradiation on P53 in FADD+/+ and FADD-/- cells

    International Nuclear Information System (INIS)

    Matic, Igor; Radnic, Maja; Marijanovic, Inga; Furcic, Ivana; Nagy, Biserka

    2008-01-01

    The dominant paradigm of tumor biology is that evasion from apoptosis is one of the crucial features of malignant diseases and that the efficiency of cancer therapy depends on P53-dependent apoptosis. Because of the importance of apoptotic pathways in protecting cells against malignant transformation, disruption of apoptosis is extremely common in cancer cells, and is frequently due to mutations in the P53 tumor suppressor gene. Fas-associated death domain (FADD) is an adapter protein that is required for apoptosis induced by all known death receptors. FADD is implicated in death receptor-independent apoptotic response, such as DNA damage. We used embryonic fibroblasts derived from FADD knockout mice and their genetic counterparts. We predicted that UV exposure induces a loss of FADD function and leads to mutations in P53. Loss of FADD expression causes deregulation of apoptosis and expansion of mutated cells and initiation of cancer. We predicted that FADD dysfunction may be potentially advantageous for tumor growth and that FADD can act as a tumor suppressor. Cells were irradiated with UV C light (254 nm) using a germicidal lamp (Upland, CA). The culture media was drained before the irradiation and fresh media was added after. In the first experiment we irradiated cells with a dose of 25 J/m 2 and after 5 days we isolated genomic DNA but part of the cells were irradiated again with the same dose. After 5 days DNA were isolated so the cumulative irradiation dose was 50 J/m 2 . In the second experiment cells were irradiated ones with the dose of 40 J/m 2 and DNA was isolated after 18 days. Lethal dosage for each cell line is 50 J/m 2 . Genomic DNA was analyzed by allele-specific polymerase chain reaction (AS-PCR) for CC to TT mutation at codons 154-155 and 175-176 in exon 5 and for C to T mutations at codons 270 and 275 in exon 8 of the P53 gene. The mutant-specific forward primer was used for each mutation. The reverse primers for amplification of mutations were

  8. Evaluation of the effectiveness of packed red blood cell irradiation by a linear accelerator.

    Science.gov (United States)

    Olivo, Ricardo Aparecido; da Silva, Marcus Vinícius; Garcia, Fernanda Bernadelli; Soares, Sheila; Rodrigues Junior, Virmondes; Moraes-Souza, Helio

    2015-01-01

    Irradiation of blood components with ionizing radiation generated by a specific device is recommended to prevent transfusion-associated graft-versus-host disease. However, a linear accelerator can also be used in the absence of such a device, which is the case of the blood bank facility studied herein. In order to evaluate the quality of the irradiated packed red blood cells, this study aimed to determine whether the procedure currently employed in the facility is effective in inhibiting the proliferation of T lymphocytes without damaging blood components. The proliferation of T lymphocytes, plasma potassium levels, and the degree of hemolysis were evaluated and compared to blood bags that received no irradiation. Packed red blood cell bags were irradiated at a dose of 25Gy in a linear accelerator. For this purpose, a container was designed to hold the bags and to ensure even distribution of irradiation as evaluated by computed tomography and dose-volume histogram. Irradiation was observed to inhibit the proliferation of lymphocytes. The percentage of hemolysis in irradiated bags was slightly higher than in non-irradiated bags (p-value >0.05), but it was always less than 0.4% of the red cell mass. Although potassium increased in both groups, it was more pronounced in irradiated red blood cells, especially after seven days of storage, with a linear increase over storage time. The findings showed that, at an appropriate dosage and under validated conditions, the irradiation of packed red blood cells in a linear accelerator is effective, inhibiting lymphocyte proliferation but without compromising the viability of the red cells. Copyright © 2015 Associação Brasileira de Hematologia, Hemoterapia e Terapia Celular. Published by Elsevier Editora Ltda. All rights reserved.

  9. Expression of multidrug resistance gene and P-glycoprotein in nasopharyngealcarcinoma cells after irradiation

    International Nuclear Information System (INIS)

    Wang Ruoyu; Wang Hui; Fan Kai; Lv Shen

    2007-01-01

    Objective: To mimick a clinical fractionated protocol of exposure to X-radiation in vitro in order to investigate the changes in the function of MDR1 and P-gp in nasopharyngeal carcinoma (NPC) CNE cell before and after irradiation to determine the sequential order of radiotherapy and chemotherapy or the time of chemotherapy after radiotherapy in the treatment of NPC. Methods: Exponentially growing CNE cells were treated with fractionated X-radiation with total dose of 10 Gy (2 Gy per day for 5 days consecutively) in vitro. The expression of MDR1 gene was examined in CNE cells before irradiation and on days 4,8,13,17 and 21 after irradiation by RT-PCR, and its protein P-gp were detected by immunocytochemistry. The function of multidrug resistance protein P-gp was examined by MTT method. Results: Expression of MDR1 gene was below the level of detection before irradiation. Irradiation induced an overexpression of MDR1 gene on day 4, expression of MDR1 was decreased from day 8 to day 21. The overall expression of MDR1 was significantly more than that before irradiation (P<0.05) Expression of P-gp was below the level of detection before irradiation, which demonstrated that irradiation induced an overexpression of P-gp. This overexpression was increased from day 8 to day 21. The overpression of MDR1 gene was maintained dining a short period, however, the emergence of overpression of protein P-gp was later than that of MDR1 gene. Resistance index was 1 for both pre-irradiation and on day 8, and up to 8,10,11.2 on days 13, 17 and 21, respectively. The change of resistance index was accordant with the condition of overexpression of P-gp . Conclusions: Expression of P-gp in nasopharyngeal carcinoma (NPC) CNE cell was below the level of detection before irradiation. Irradiation can induce an overexpression of MDR1 gene and its protein P-gp in CNE cells. The overexpression of MDR1 gene and its protein P-gp lasted a long term. (authors)

  10. In-cell refabrication of experimental pencils from pencils pre-irradiated in a power reactor

    International Nuclear Information System (INIS)

    Vignesoult, N.; Atabek, R.; Ducas, S.

    1980-05-01

    For the fuel-cladding study, small irradiated pencils were fabricated in a hot cell from long elements taken from power reactors. This reconstitution in a hot cell makes it possible to: - avoid long and costly fabrications of pencils and pre-irradiations in experimental reactors, - perform re-irradiations on very long fuel elements from power reactors, - fabricate several small pencils from one pre-irradiation pencil having homogeneous characteristics. This paper describes (a) the various in-cell fabrication stages of small pre-irradiated pencils, stressing the precautions taken to avoid any pollution and modifications in the characteristics of the pencil, in order to carry out a perfectly representative re-irradiation, (b) the equipment used and the quality control made, and (c) the results achieved and the qualification programme of this operation [fr

  11. Low-level laser irradiation induces in vitro proliferation of mesenchymal stem cells

    Energy Technology Data Exchange (ETDEWEB)

    Barboza, Carlos Augusto Galvão; Ginani, Fernanda [Universidade Federal do Rio Grande do Norte, Natal, RN (Brazil); Soares, Diego Moura [Universidade Federal de Pernambuco, Recife, PE (Brazil); Henriques, Águida Cristina Gomes; Freitas, Roseana de Almeida [Universidade Federal do Rio Grande do Norte, Natal, RN (Brazil)

    2014-07-01

    To evaluate the effect of low-level laser irradiation on the proliferation and possible nuclear morphological changes of mouse mesenchymal stem cells. Mesenchymal stem cells derived from bone marrow and adipose tissue were submitted to two applications (T0 and T48 hours) of low-level laser irradiation (660nm; doses of 0.5 and 1.0J/cm{sup 2}). The trypan blue assay was used to evaluate cell viability, and growth curves were used to analyze proliferation at zero, 24, 48, and 72 hours. Nuclear alterations were evaluated by staining with DAPI (4'-6-diamidino-2-phenylindole) at 72 hours. Bone marrow-derived mesenchymal stem cells responded to laser therapy in a dose-dependent manner. Higher cell growth was observed when the cells were irradiated with a dose of 1.0J/cm{sup 2}, especially after 24 hours (p<0.01). Adipose-derived mesenchymal stem cells responded better to a dose of 1.0J/cm{sup 2}, but higher cell proliferation was observed after 48 hours (p<0.05) and 72 hours (p<0.01). Neither nuclear alterations nor a significant change in cell viability was detected in the studied groups. Low-level laser irradiation stimulated the proliferation of mouse mesenchymal stem cells without causing nuclear alterations. The biostimulation of mesenchymal stem cells using laser therapy might be an important tool for regenerative therapy and tissue engineering.

  12. A comparison study on of tumor cell-killing effects between low-dose-rate β-irradiation of 32P and γ-irradiation of 60Co

    International Nuclear Information System (INIS)

    Feng Huiru; Tian Jiahe; Ding Weimin; Zhang Jinming; Chen Yingmao

    2004-01-01

    The paper is to elucidate radiobiological characteristics and radiobiological mechanism in killing tumor cells with low dose rate β-rays and high dose rate γ-rays. HeLa cells were exposed to low-rate β-irradiation of 32 P or high-dose-rate γ-irradiation of 60 Co. Cell response-patterns were compared between two the types of radiations in terms of their inhibition of cell proliferation and cell cycle blockage, evaluated by trypanblue excluded method and flow cytometry, respectively. Results show that there is a different way in growth inhibition effect on HeLa cells between low-dose-rate irradiation of 32 P and high-dose-rate irradiation of 60 Co γ. In exposure to 32 P, the inhibition of cell proliferation in HeLa cell was a prolong course, whereas and the effect was in a more serious and quick way in 60 Co irradiation. Cell cycle arrest in G 2 phase induced by 32 P was lower and more prolong than that induced by 60 Co. The inhibition effect on tumor cells between the two types of radiations is different. Impaired DNA repair system by continuous low-dose-rate radiation might contribute to the final radiation effect of 32 P

  13. 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

  14. Carbon-ion beam irradiation kills X-ray-resistant p53-null cancer cells by inducing mitotic catastrophe.

    Directory of Open Access Journals (Sweden)

    Napapat Amornwichet

    Full Text Available BACKGROUND AND PURPOSE: To understand the mechanisms involved in the strong killing effect of carbon-ion beam irradiation on cancer cells with TP53 tumor suppressor gene deficiencies. MATERIALS AND METHODS: DNA damage responses after carbon-ion beam or X-ray irradiation in isogenic HCT116 colorectal cancer cell lines with and without TP53 (p53+/+ and p53-/-, respectively were analyzed as follows: cell survival by clonogenic assay, cell death modes by morphologic observation of DAPI-stained nuclei, DNA double-strand breaks (DSBs by immunostaining of phosphorylated H2AX (γH2AX, and cell cycle by flow cytometry and immunostaining of Ser10-phosphorylated histone H3. RESULTS: The p53-/- cells were more resistant than the p53+/+ cells to X-ray irradiation, while the sensitivities of the p53+/+ and p53-/- cells to carbon-ion beam irradiation were comparable. X-ray and carbon-ion beam irradiations predominantly induced apoptosis of the p53+/+ cells but not the p53-/- cells. In the p53-/- cells, carbon-ion beam irradiation, but not X-ray irradiation, markedly induced mitotic catastrophe that was associated with premature mitotic entry with harboring long-retained DSBs at 24 h post-irradiation. CONCLUSIONS: Efficient induction of mitotic catastrophe in apoptosis-resistant p53-deficient cells implies a strong cancer cell-killing effect of carbon-ion beam irradiation that is independent of the p53 status, suggesting its biological advantage over X-ray treatment.

  15. Radiation induced bystander signals are independent of DNA damage and DNA repair capacity of the irradiated cells

    Energy Technology Data Exchange (ETDEWEB)

    Kashino, Genro [Gray Cancer Institute, P.O. Box 100, Mount Vernon Hospital, Northwood, Middlesex HA6 2JR (United Kingdom); Particle Radiation Oncology Research Center, Research Reactor Institute, Kyoto University, 2-1010 Asashiro-nishi, Kumatori-cho, Sennan-gun, Osaka 590-0494 (Japan); Suzuki, Keiji [Division of Radiation Biology, Department of Radiology and Radiation Biology, Course of Life Sciences and Radiation Research, Graduate School of Biomedical Sciences, Nagasaki University, 1-14 Bunkyo-machi, Nagasaki 852-8521 (Japan); Matsuda, Naoki [Division of Radiation Biology and Protection, Center for Frontier Life Sciences, Nagasaki University, Nagasaki 852-8102 (Japan); Kodama, Seiji [Radiation Biology Laboratory, Radiation Research Center, Frontier Science Innovation Center, Organization for University-Industry-Government Cooperation, Osaka Prefecture University, 1-2 Gakuen-cho, Sakai, Osaka 599-8570 (Japan); Ono, Koji [Particle Radiation Oncology Research Center, Research Reactor Institute, Kyoto University, 2-1010 Asashiro-nishi, Kumatori-cho, Sennan-gun, Osaka 590-0494 (Japan); Watanabe, Masami [Laboratory of Radiation Biology, Division of Radiation Life Science, Department of Radiation Life Science and Radiation Medical Science, Kyoto University Research Reactor Institute, 2-1010 Asashiro-nishi, Kumatori-cho, Sennan-gun, Osaka 590-0494 (Japan); Prise, Kevin M [Gray Cancer Institute, P.O. Box 100, Mount Vernon Hospital, Northwood, Middlesex HA6 2JR (United Kingdom) and Centre for Cancer Research and Cell Biology, Queen' s University Belfast, Lisburn Road, Belfast BT9 7AB (United Kingdom)]. E-mail: prise@gci.ac.uk

    2007-06-01

    Evidence is accumulating that irradiated cells produce signals, which interact with non-exposed cells in the same population. Here, we analysed the mechanism for bystander signal arising in wild-type CHO cells and repair deficient varients, focussing on the relationship between DNA repair capacity and bystander signal arising in irradiated cells. In order to investigate the bystander effect, we carried out medium transfer experiments after X-irradiation where micronuclei were scored in non-targeted DSB repair deficient xrs5 cells. When conditioned medium from irradiated cells was transferred to unirradiated xrs5 cells, the level of induction was independent of whether the medium came from irradiated wild-type, ssb or dsb repair deficient cells. This result suggests that the activation of a bystander signal is independent of the DNA repair capacity of the irradiated cells. Also, pre-treatment of the irradiated cells with 0.5% DMSO, which suppresses micronuclei induction in CHO but not in xrs5 cells, suppressed bystander effects completely in both conditioned media, suggesting that DMSO is effective for suppression of bystander signal arising independently of DNA damage in irradiated cells. Overall the work presented here adds to the understanding that it is the repair phenotype of the cells receiving bystander signals, which determines overall response rather than that of the cell producing the bystander signal.

  16. Delayed reproductive death as a dominant phenotype in cell clones surviving X-irradiation

    International Nuclear Information System (INIS)

    Chang, W.P.; Little, J.B.

    1992-01-01

    Residual damage manifested as reduced cloning efficiency was observed in many of the cloned progeny of Chinese hamster ovary (CHO) cells and human carcinoma SQ-20B cells surviving X-irradiation. This stable phenotype, which we have termed delayed reproductive death, persisted for >50 generations of cell replication post-irradiation. Clones showing this phenotype were aneuploid, and formed colonies with a high proportion of giant cells. By somatic cell hybridization of CHO clones, the delayed reproductive death phenotype was found to be a dominant trait; the cloning efficiency of hybrid clones was persistently depressed, as compared with that of control hybrid cells. These results suggest that delayed reproductive death represents a specific cellular response that may persist in some of the progeny of mammalian cells for long periods after X-irradiation. (author)

  17. Reductone effect on UV-irradiated starved E. coli cells

    International Nuclear Information System (INIS)

    Felzenszwalb, I.; Gomes, R.A.

    1982-01-01

    A starvation-induced resistence enhancement (SIRE) to UV and reductone treatments was observed in repair-profient E. coli cells. The UV-reductone positive interaction, which is possibly related to excision repair mechanisms, was not modified by prestarvation when all cells in culture had completed their round of DNA replication. In irradiated prestarved reductone-treated cells, a decrease in the DNA degradation rate was detected after the removal of reductone and the induction of a lower number of DNA single-strand breaks. The induction kinectics of DNA single-strand breaks in prestarved UV-irradiated and the repair kinetics of these lesions are slower than in non-starved cells. The resistance enhancement demonstrated under these conditions could be justified either by the generation of fewer doubles strand breaks during repair or by the possibility of repair of these lesions. (Author) [pt

  18. Low-intensity laser irradiation at 660 nm stimulates cytochrome c oxidase in stressed fibroblast cells.

    Science.gov (United States)

    Houreld, Nicolette N; Masha, Roland T; Abrahamse, Heidi

    2012-07-01

    Low-intensity laser irradiation (LILI) has been used to modulate a variety of biological processes, including diabetic wound healing. The mechanism of action is thought to exist primarily with the mitochondria. This study aimed to determine the effect of irradiation on normal, diabetic, and ischemic mitochondrial electron transport chain (ETC) complexes. Normal, diabetic and ischemic human skin fibroblast mitochondria were irradiated in vitro at a wavelength of 660 nm and a fluence of either 5 or 15 J/cm(2). Non-irradiated mitochondria served as controls. Enzyme activities of mitochondrial complexes I, II, III, and IV were determined immediately post-irradiation. Normal, diabetic, and ischemic cells were irradiated and adenosine triphosphate (ATP) and active mitochondria were determined by luminescence and fluorescent microscopy, respectively. Irradiated diabetic mitochondria at a fluence of 15 J/cm(2) showed a significant decrease in complex III activity (P < 0.05). Normal (P < 0.01) and diabetic (P < 0.05) mitochondria irradiated at either 5 or 15 J/cm(2) showed a significant increase in complex IV activity. ATP results showed a significant increase in irradiated normal cells (5 J/cm(2); P < 0.05) and diabetic cells (15 J/cm(2); P < 0.01). There was a higher accumulation of active mitochondria in irradiated cells than non-irradiated cells. Irradiation at 660 nm has the ability to influence mitochondrial enzyme activity, in particular cytochrome c oxidase. This leads to increased mitochondrial activity and ATP synthesis. Copyright © 2012 Wiley Periodicals, Inc.

  19. Gamma-irradiation and neutron effect on DNA-membrane complexes of mammalian cells

    International Nuclear Information System (INIS)

    Lapidus, I.L.; Nazarov, V.M.; Ehrtsgreber, G.

    1984-01-01

    The first results of radiobiological investigations in the biophysical channel of the JINR reactor IBR-2 are presented. Sedimentation behaviour of DNA-membrane complexes has been studied at irradiation of the Chinese hamster cells (VT9-4) in a wide dose range of 137 Cs γ-irradiation and neutrons. An earlier assumption of the authors on the role of DNA double-strand breaks in changing the relative sedimentation velocity of complexes at irradiation of cells with doses over 50 Gy has been confirmed

  20. Heritable non-lethal damage to cultured human cells irradiated with heavy ions

    International Nuclear Information System (INIS)

    Walker, J.T.; Walker, O.A.

    2002-01-01

    During interplanetary flights the nuclei of all of a crew member's cells could be traversed by at least one high-LET (linear energy transfer) cosmic-ray particle. In mammalian cells irradiated in vitro about 1 in 10,000 of the surviving cells traversed by heavy particles is transformed to malignancy or mutated. What, if anything, happens to the remaining >99% of surviving cells? A retrospective analysis of archived data and samples from heavy-ion irradiation experiments with cultured human cells in vitro indicated that heavy ions caused a dose- and LET-dependent reduction in growth rates of progeny of irradiated cells, based on colony-size distributions. The maximum action cross section for this effect is between 100 and 300 μm 2 , at least as large as the cell nuclear area and up to 3 times the cross section for cell killing. Thus, heritable slow growth is the most prevalent effect of high-LET radiations on cultured animal cells, which may have implications for crew health during deep space travel. (author)

  1. Repair of potentially lethal and sublethal radiation damage in x-irradiated ascites tumor cells

    International Nuclear Information System (INIS)

    Tsuboi, Atsushi; Okamoto, Mieko; Tsuchiya, Takehiko.

    1985-01-01

    The ability of cells to repair cellular radiation damage during the growth of TMT-3 ascites tumor and the effect of host reaction on the repair ability were examined by using an in vitro assay of cell clonogenicity after in situ irradiation of tumor cells. In single-dose experiments, the repair of potentially lethal radiation damage (PLD) was observed in stationary phase cells (12-day tumor) of the unirradiated host, but not in exponential phase cells (3-day tumor) of the unirradiated host animals. However, if previously irradiated host animals were used, even the exponentially growing tumor cells showed repair of PLD. In two-dose experiments, the ability to repair sublethal radiation damage (SLD) in exponential phase tumor cells was less than that of stationary phase cells in the unirradiated host. In the pre-irradiated host, the extent of the repair in exponential phase cells was somewhat enhanced. These results suggest that irradiation of host animals might suppress a factor that inhibits repair, resulting in enhancement of the repair capability of tumor cells. (author)

  2. Change in the dibenzyldimethylammonium accumulation by irradiated Streptococcus cells caused by radiation damage modifiers

    International Nuclear Information System (INIS)

    Fomenko, B.S.; Leont'eva, G.A.

    1975-01-01

    Anoxia, concentrated cell suspension, glutathione (10 -4 -10 -2 M) or low concentrations of cysteine (10 -4 -10 -3 M) exerted a radioprotective effect and suppressed the accumulation of dibenzyldimethylammonium chloride (DDA + ) by γ-irradiated (40 krad) S. faecalis cells. Dilution of the cell suspensions and higher cysteine concentrations (>10 -3 M) increased the effects of irradiation on bacterial accumulation of DDA + and decreased the cell survival. The lethal action of irradiation apparently involves damage to the mechanisms which maintain a normal membrane potential

  3. Cell division requirement for activation of murine leukemia virus in cell culture by irradiation

    International Nuclear Information System (INIS)

    Otten, J.A.; Quarles, J.M.; Tennant, R.W.

    1976-01-01

    Actively dividing cultures of AKR mouse cells were exposed to relatively low dose-rates of γ radiation and tested for activation of endogenous leukemia viruses. Efficient and reproducible induction of virus was obtained with actively dividing cells, but cultures deprived of serum to inhibit cell division before and during γ irradiation were not activated, even when medium with serum was added immediately after irradiation. These results show that cell division was required for virus induction but that a stable intermediate similar to the state induced by halogenated pyrimidines was not formed. In actively dividing AKR cell cultures, virus activation appeared to be proportional to the dose of γ radiation; the estimated frequency of activation was 1-8 x 10 - 5 per exposed cell and the efficiency of activation was approximately 0.012 inductions per cell per rad. Other normal primary and established mouse cell cultures tested were not activated by γ radiation. The requirement of cell division for radiation and chemical activation may reflect some common mechanism for initiation of virus expression

  4. Comparison of the effect between an active specific immunotherapy using the immune reaction of a low-dose irradiated tumor tissue and that using irradiated tumor cells

    International Nuclear Information System (INIS)

    Ogawa, Yasuhiro; Maeda, Tomoho; Yoshida, Shoji; Yamamoto, Yoichi; Morita, Masaru

    1983-01-01

    The effect of the active specific immunotherapy using the immune reaction of a low-dose irradiated tumor tissue was compared with that of irradiated (10,000 rads) tumor cells on the transplanted MM46 tumor of female C3H/He mice after radiotherapy. MM46 tumor cells were inoculated into the right hind paws of mice. On the 6th day, irradiation with a dose of 3,000 rads was performed. On the 14th day, tumor cells and concomitant mononuclear cells which were separated from the low-dose irradiated tumor tissue (2,000 rads on the 6th day) were injected into the left hind paws of one group of the tumor-bearing mice. On the same day, irradiated MM46 tumor cells were injected into the left hind paws of another group of the tumor-bearing mice. Effectiveness of these two methods of active specific immunotherapy against tumor was evaluated by the regression of tumor and survival rate of mice. The active specific immunotherapy using the immune reaction of a low-dose irradiated tumor tissue was far more effective than irradiated tumor cells on this tumor system involved. (author)

  5. Fast kinetics of the oxygen effect in irradiated mammalian cells

    International Nuclear Information System (INIS)

    Watts, M.E.; Maughan, R.L.; Michael, B.D.

    1978-01-01

    A technique using a fast gas transfer with a single pulse of electrons (the gas-explosion technique) has been used to investigate the time-dependence of the dose-modifying action of oxygen in irradiated V79 Chinese hamster cells. Oxygen did not significantly alter the shapes of the survival curves. The dose-modifying factor between the fully oxic and fully hypoxic (oxygen at 9000 ms) curve was 2.6. The dose-modifying factor for the survival curve drawn for oxygen contact at 0.3 ms after irradiation was 1.5 relative to the hypoxic curve. The duration of the post-effect (oxygen contact after irradiation) indicated that oxygen-dependent damage has a lifetime extending into the ms time-range. In the pre-effect time region (oxygen contact before irradiation) 1 to 2 ms oxygen contact was required to achieve the full sensitization. The results are discussed with reference to the diffusion time for oxygen to reach the sensitive site within the cell. (U.K.)

  6. Generation of cytotoxic T lymphocytes in vitro. VII. Suppressive effect of irradiated MLC cells on CTL response

    International Nuclear Information System (INIS)

    Fitch, F.W.; Engers, H.D.; Cerottini, J.C.; Bruner, K.T.

    1976-01-01

    Irradiated cells obtained from MLC at the peak of the CTL response caused profound suppression of generation of CTL when added in small numbers at the initiation of primary MLC prepared with normal spleen cells. The inhibitory activity of the MLC cells was not affected by irradiation (1000 rads) but was abolished by treatment with anti-theta serum and complement. The suppression was immunologically specific. The response of A (H-2/sup a/) spleen cells toward C3H (H-2/sup k/) alloantigens was suppressed by irradiated MLC cells obtained from MLC prepared with A spleen cells and irradiated C3H-stimulating cells, whereas the response of A spleen cells toward DBA/2 (H-2/sup d/) alloantigens was affected relatively little. However, if irradiated C3H x DBA/2F1 hybrid spleen cells were used to stimulate A spleen cells in MLC, addition of irradiated MLC cells having cytotoxic activity toward C3H antigens abolished the response to both C3H and DBA/2 antigens. The response to DBA/2 antigens was much less affected when a mixture of irradiated C3H and DBA/2 spleen cells was used as stimulating cells. Thus, the presence of MLC cells having cytotoxic activity toward one alloantigen abolished the response to another non-cross-reacting antigen only when both antigens were present on the same F1 hybrid-stimulating cells. This suppression of generation of CTL by irradiated MLC cells apparently involves inactivation of alloantigen-bearing stimulating cells as a result of residual cytotoxic activity of the irradiated MLC cells. This mechanism may be active during the decline in CTL activity noted in the normal immune response in vivo and in vitro

  7. Movement of beta-irradiated epidermal basal cells to the spinous-granular layers in the absence of cell division

    International Nuclear Information System (INIS)

    Etoh, H.; Taguchi, Y.H.; Tabachnick, J.

    1975-01-01

    Guinea-pig epidermis was irradiated with 3000 rad of beta rays 1 hr after two injections of [ 3 H]thymidine 5 hr apart (labeled cells in S phase and G 2 phase) or 18 hr after injection (labeled early G 1 cells). In nonirradiated epidermis labeled basal cells divided within 24 hr with daughter cells remaining in the basal layer, and approximately 50 percent of the labeled cells moved into the spinal layer by the 3rd day. Cell division in nonirradiated epidermis diluted the number of silver grains/nucleus, and lightly labeled cells were found in the granular layer by day 7. Beta irradiation inhibited cell division but it did not slow the rate of transit (ca 8 days) of irradiated labeled cells from basal to granular layer, some of these remaining heavily labeled. Although cell division may play some role in upward movement of basal cells in normal epidermis detachment of a basal cell from the basement membrane and its transit to the granular layer is unimpaired in the absence of cell division. These findings suggest that some radioresistant metabolic function(s), not cell division, is responsible for upward movement of basal cells. (auth)

  8. Abrogation of Early Apoptosis Does Not Alter Late Inhibition of Hippocampal Neurogenesis After Irradiation

    International Nuclear Information System (INIS)

    Li Yuqing; Aubert, Isabelle; Wong, C. Shun

    2010-01-01

    Purpose: Irradiation of the adult brain results in acute apoptosis of neural progenitors and vascular endothelial cells, as well as late dysfunction of neural progenitors and inhibition of neurogenesis. We sought to determine whether the early apoptotic response has a causative role in late inhibition of neurogenesis after cranial irradiation. Methods and Materials: Using a genetic approach with p53 and smpd1 transgenic mice and a pharmacologic approach with basic fibroblast growth factor (bFGF) to abrogate the early apoptotic response, we evaluated the late inhibition of neurogenesis in the hippocampal dentate gyrus after cranial irradiation. Results: In dentate gyrus, subgranular neural progenitors underwent p53-dependent apoptosis within 24 h after irradiation. Despite a near abrogation of neural progenitor apoptosis in p53-/- mice, the reduction in newborn neurons in dentate gyrus at 9 weeks after irradiation in p53-/- mice was not different from that observed in wildtype controls. Endothelial cell apoptosis after radiation is mediated by membrane damage initiated by activation of acid sphingomyelinase (ASMase). Deletion of the smpd1 gene (which encodes ASMase) attenuated the apoptotic response of endothelial cells. At 9 weeks after irradiation, the inhibition of hippocampal neurogenesis was not rescued by ASMase deficiency. Intravenous administration of bFGF protected both endothelial cells and neural progenitors against radiation-induced apoptosis. There was no protection against inhibition of neurogenesis at 9 weeks after irradiation in bFGF-treated mice. Conclusion: Early apoptotic death of neural progenitors, endothelial cells, or both does not have a causative association with late inhibition of neurogenesis after irradiation.

  9. Herpes simplex virus produces larger plaques when assayed on ultraviolet irradiated CV1 cells

    International Nuclear Information System (INIS)

    Coohill, T.P.; Babich, M.A.; Taylor, W.D.; Snipes, W.

    1980-01-01

    Plaque development for either untreated or UV treated irradiated Herpes simplex virus Type 1 was faster when assayed on UV irradiated CV1 cells. This Large Plaque Effect only occurred if a minimum delay of 12h between cell irradiation and viral inoculation was allowed. Shorter delays gave plaques that were smaller than controls (unirradiated virus-unirradiated cells). The effect was maximal for a 48-h delay and remained unchanged for delays as long as 84h. The effect was greatest for cell exposures of 10Jm -2 . (author)

  10. Comparison of six different models describing survival of mammalian cells after irradiation

    International Nuclear Information System (INIS)

    Sontag, W.

    1990-01-01

    Six different cell-survival models have been compared. All models are based on the similar assumption that irradiated cells are able to exist in one of three states. S A is the state of a totally repaired cell, in state S C the cell contains lethal lesions and in state S b the cell contains potentially lethal lesions i.e. those which either can be repaired or converted into lethal lesions. The differences between the six models lie in the different mathematical relationships between the three states. To test the six models, six different sets of experimental data were used which describe cell survival at different repair times after irradiation with sparsely ionizing irradiation. In order to compare the models, a goodness-of-fit function was used. The differences between the six models were tested by use of the nonparametric Mann-Whitney two sample test. Based on the 95% confidence limit, this required separation into three groups. (orig.)

  11. Fluorescent light irradiation and its mutagenic potential in cultured mammalian cells

    International Nuclear Information System (INIS)

    Pant, K.; Thilager, A.

    1994-01-01

    The photobiological effect of light is characterized by its energy emission at different wave lengths. Therefore by studying the energy emission spectra at different light sources and their photobiological activities, one can relate wavelength range(s) of the spectrum to a particular photobiological effect. We studied the potential of light irradiation from standard fluorescent bulbs (Sylvania 34WT-12) used in offices and laboratories to induce unscheduled DNA Synthesis (UDS) and mutations in cultured mammalian cells. The energy emission spectrum of the bulbs was determined at every 10 nanometers from 300nM to 700nM. The Chinese hamster ovary (CHO) cells were used to study the induction of mutations at the Hypoxanthine Guanine Phosphoribosyl Transferase (HGPRT) locus. Primary rat hepatocyte cultures were used to study the effect of light irradiation on UDS. The CHO cells were cultured in tissue culture flasks in minimum light conditions (.02mw/cm 2 ) and exposed to light irradiations with durations from 0 to 40 minutes. The cultures were maintained in darkness during the expression period and evaluated for HGPRT mutant frequencies. Similarly, the primary rat hepatocyte cultures were cultured on cover slips under minimal light conditions except for light irradiation and evaluated for UDS using 3H-thymidine labelled auto-radiography. The results of the study indicate that irradiation from fluorescent lights caused a slight elevation in the HGPRT mutant frequency in CHO cells. However a significant increase in UDS was not observed even at the maximum light irradiation dose. These results were compared to data obtained from similar experiments conducted with fluorescent bulbs with different energy emission spectra

  12. Evaluation of 18F-FDG and 18F-FLT for monitoring therapeutic responses of colorectal cancer cells to radiotherapy

    International Nuclear Information System (INIS)

    Wang, Hui; Liu, Bo; Tian, Jiahe; Xu, Baixuan; Zhang, Jinming; Qu, Baolin; Chen, Yingmao

    2013-01-01

    In order to compare the efficacy of 18 F-fluorothymidine (FLT) and 18 F-fluorodeoxyglucose (FDG) for monitoring early responses to irradiation, two human colorectal cancer (CRC) cell lines SW480 and SW620, which were derived from the primary lesions and the metastatic lymph node, underwent X-ray irradiation of 0, 10, or 20 Gy and were examined at 0, 24 and 72 h After irradiation, reduced proliferation of both SW480 and SW620 cells was observed in a dose-dependent manner (P < 0.001), G0-G1 arrest was also noted in both cell types after 72 h in the 20 Gy group (P < 0.001). Although increased apoptosis was observed in both cell lines after irradiation (P < 0.001), a greater percentage of SW480 cells underwent apoptosis in response to irradiation than SW620 cells. Increased Hsp27 and decreased integrin β 3 , Ki67 and VEGFR2 expression was observed over time via immunocytochemistry and Western blot analysis (P < 0.001), however, no significant changes were noted in response to irradiation. Finally, reduced uptake of 18 F-FLT by SW480 or SW620 cells was observed at 24-h post-irradiation, however, reduced 18 F-FDG uptake was only observed after 72 h. Therefore, we conclude that 18 F-FLT is a more suitable positron emission tomography (PET) tracer for monitoring early responses to irradiation in primary and metastatic lymph node CRC cells

  13. Polycarbonate surface cell's adhesion examination after Nd:YAG laser irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Ramazani, S.A. Ahmad, E-mail: Ramazani@sharif.ir [Polymer Group, Department of Chemical and Petroleum Engineering, Sharif University of Technology, Tehran (Iran, Islamic Republic of); Mousavi, Seyyed Abbas, E-mail: Musavi@che.sharif.ir [Department of Chemistry, Sharif University of Technology, Tehran (Iran, Islamic Republic of); Seyedjafari, Ehsan [Department of Biotechnology, University College of Science, University of Tehran (Iran, Islamic Republic of); Poursalehi, Reza [Department of Physics, University of Shahed, Tehran (Iran, Islamic Republic of); Sareh, Shohreh [Research Center of Iranian Blood Transfusion Organization, Tehran (Iran, Islamic Republic of); Silakhori, Kaveh [Laser Research Center, Atomic Energy Organization, Tehran (Iran, Islamic Republic of); Poorfatollah, Ali Akbar [Research Center of Iranian Blood Transfusion Organization, Tehran (Iran, Islamic Republic of); Shamkhali, Amir Nasser [Department of Chemistry, Sharif University of Technology, Tehran (Iran, Islamic Republic of)

    2009-05-05

    Nd:YAG laser treatment was used in order to increase surface cell adhesion aspects of polycarbonate (PC) films prepared via melt process. The treatment was carried out under different wavelengths and beam diameters. ATR-FTIR and UV spectra obtained from different samples before and after laser treatment in air showed that laser irradiation has induced some chemical and physical changes in surface properties. The irradiated films were also characterized using scanning electron microscopy (SEM) and contact angle measurements. Effect of pulse numbers on the surface properties was also investigated. Cell culture test was used to evaluate cell adhesion property on the PC films before and after treatment. The results obtained from this test showed that after laser treatment, the cells were attached and proliferated extensively on the Nd:YAG laser treated films in comparison with the unmodified PC. Moreover, it was revealed that a decrease in the laser beam diameter and an increase in the irradiated pulse numbers increased surface wettability and caused a better cell attachment on the polymer surface. The obtained results also showed that a decrease in the laser beam diameter and an increase in the irradiated pulse numbers increased surface wettability and caused a better cell attachment on the polymer surface.

  14. Effect of low-level laser irradiation on osteoblast-like cells cultured on porous hydroxyapatite scaffolds

    Directory of Open Access Journals (Sweden)

    Serena Incerti Parenti

    2013-09-01

    Full Text Available OBJECTIVE: To determine the effect of laser irradiation at a low dose on human osteoblastlike cells. Materials and methods: 32 porous hydroxyapatite scaffolds currently used for bone tissue engineering were seeded with MG63 cells and irradiated or not with a GaAlAs diode laser (wavelength 915 nm, dose 2 J/cm² using different power density and exposure duration. RESULTS: After 72-h incubation, cells showed well spread morphology and good adhesion on both laser-treated and untreated scaffolds. Laser irradiation did not interfere in cell viability and proliferation as compared with the non-irradiated controls. CONCLUSION: This study suggests that there is no effect of 915 nm laser irradiation at a dose of 2 J/cm² on the proliferation rate of MG63 cells. Future investigations are needed to compare different dose and wavelength regimens in order to determine the optimal set of laser parameters for maximum cell yield and safe clinical application.

  15. HTB140 melanoma cells under proton irradiation and/or alkylating agents

    Science.gov (United States)

    Korićanac, L.; Petrović, I.; Privitera, G.; Cuttone, G.; Ristić-Fira, A.

    2007-09-01

    Chemoresistance is a major problem in the treatment of malignant melanoma. The mainstay of treatment for melanoma is the DNA-alkylating agent dacarbazine (DTIC). Fotemustine (FM), a member of the chloroethylnitrosourea group of alkylating agents, has also demonstrated significant antitumor effects in malignant melanoma. However, the intrinsic and acquired resistance of melanoma limits the clinical application of these drugs. Melanomas are also extremely radioresistant. With the objective of enhancing growth inhibition of melanoma cells, combined treatments of FM or DTIC with proton irradiation have been investigated. These effects were studied on HTB140 melanoma cell viability and proliferation. Cells exposed to treatment with FM and protons have shown inhibition of cell growth and significant reduction of proliferation capacity compared to single irradiation or drug treatment. Treatment with DTIC and protons has shown improved growth inhibition compared to appropriate single drug treatment, while the effects of single proton irradiation have been the most pronounced.

  16. Development of the IFJ single ion hit facility for cells irradiation

    International Nuclear Information System (INIS)

    Veselov, O.; Polak, W.; Ugenskiene, R.; Hajduk, R.; Lebed, K.; Lekki, J.; Horwacik, T.; Dutkiewicz, E.M.; Maranda, S.; Pieprzyca, T.; Sarnecki, C.; Stachura, Z.; Szklarz, Z.; Styczen, J.

    2005-12-01

    In recent years a single ion hit facility (SIHF) has been constructed at the IFJ ion microprobe. The setup is used for the precise irradiations of living cells by a controlled number of ions. The facility allows investigations in various aspects of biomedical research, such as adaptive response, bystander effect, inverse dose-rate effect, low-dose hypersensitivity, etc. Those investigations have two very important requirements: (i) cells must be examined in their natural state and environment, i.e. without previously being killed, and preferentially, neither fixed nor stained, and (ii) a possibility of automatic irradiation of large number of cells with a computer recognition of their positions must be provided. This work presents some of the crucial features of the off-line and on-line optical systems, including self-developed software responsible for the automatic cell recognition. We also show several tests carried out to determine the efficiency of the whole setup and some segments. In conclusion, the results of our first irradiation measurements performed with living cells are demonstrated. (author)

  17. Phospholipid metabolism in lymphoid cells at delayed periods following sublethal γ-irradiation of rats

    International Nuclear Information System (INIS)

    Novoselova, E.G.

    1991-01-01

    Dynamics of phospholipid metabolism in rat thymocytes and bone marrow cells was studied 1-6 months after fractionated irradiation. The rate of total and individual lipid synthesis was shown to increase in the exposed cells. The rate of lipid synthesis increased 1 and 2 months after irradiation and was normalized 3 and 6 months after irradiation

  18. Model animal experiments on UV-c irradiation of blood and isolated cell populations

    International Nuclear Information System (INIS)

    Repke, H.; Scherf, H.P.; Wiesner, S.

    1984-01-01

    The cellular and molecular basis of the therapeutically used effect of reinjected ultraviolet (UVC) irradiated blood is unknown. First approaches to that problem were made in this study by aid of model experiments. Neither the spontaneous degranulation nor the antigen-induced histamine release from rat connective tissue mast cells (in vivo) was influenced by the injection (i.v.) of UV-irradiated blood or blood lymphocytes. By comparison of the effect of UV light on blood lymphocytes (number of dead cells, strength of chemoluminescence) after irradiation of the isolated cells and the unfractionated blood, respectively, it was shown that the strong light absorption within the blood sample prevents damage or functional alterations of the blood lymphocytes. The compound 48/80 - induced histamine release from rat peritoneal mast cells can be completely inhibited by UV irradiation (0.6 mJ/cm 2 ) without increasing the spontaneous histamine release. (author)

  19. In vitro gamma irradiation Medical Center of leukemic cells in mice, rats, and guinea pigs

    International Nuclear Information System (INIS)

    Gross, L.; Dreyfuss, Y.; Ehrenreich, T.; Feldman, D.; Limbert, L.M.

    1980-01-01

    In vitro gamma irradiation of virus-induced (Gross) mouse leukemia cells at doses of 350 to 1600 rads (1 rad = 0.01 gray) had no effect on their ability to induce leukemia, usually within 2 weeks, after transplantation into syngeneic mice. However, when cells irradiated at doses of 2000-20,000 rads were transplanted, they induced leukemia after a latency period exceeding 2.5 months, similar to the results observed in mice inoculated with filtered mouse leukemia extracts. Similar results were also obtained after irradiation of leukemic cells derived from rats in which leukemia had been induced by rat-adapted mouse leukemia virus. Apparently, gamma irradiation at a dose of, or exceeding, 2000 rads, inhibits the ability of mouse and rat leukemic cells to induce leukemia after transplantation into syngeneic hosts; however, it does not inactivate the virus carried by such cells nor prevent it from inducing leukemia. [In previous experiments, doses of more than 4,500,000 rads were needed to inactivate the passage A (Gross) leukemia virus carried in either mouse or rat leukemic cells.] In vitro gamma irradiation of L2C guinea pig leukemic cells at doses of 750 to 2500 rads had no apparent effect on their ability to induce leukemia after transplantation into strain 2 guinea pigs. However, irradiation at doses of 3250 to 20,000 rads inactivated their ability to do so. The morphology of mouse, rat, and guinea pig leukemic cells and the virus particles present in such cells was not affected by irradiation at doses of 20,000 rads

  20. Enhancement of postreplication repair in ultraviolet-light-irradiated Chinese hamster cells by irradiation in G2 or s-phase

    International Nuclear Information System (INIS)

    D'Ambrosio, S.M.; Aebersold, P.M.; Setlow, R.B.

    1978-01-01

    Postreplication repair in synchronous Chinese hamster cells was determined after split doses of ultraviolet (uv) radiation. Repair was enhanced by irradiation of cells in G 2 or S-phase with a small dose of uv radiation at least 1.5 h before a three-fold larger dose of uv. There was significantly greater enhancement when the first dose was given in G 2 than when it was given in the S-phase 0.5 to 1.5 h before the test dose. These data indicate that enhancement of postreplication repair does not require active DNA replication and qualitatively is independent of when in the cell cycle the cells are irradiated

  1. Effects of x-irradiation on cell division, oxygen consumption, and growth medium pH of an insect cell line cultured in vitro

    International Nuclear Information System (INIS)

    Koval, T.M.; Myser, W.C.; Hink, W.F.

    1975-01-01

    Cultured Trichoplusia ni cells in exponential growth were administered x-ray doses of 10,000 R and then subcultured. The untreated cell population began exponential growth within a few hours after subculture, eventually reaching stationary growth phase 96 hr later at a cell density of 2.08 x 10 6 cells/ml, whereas the irradiated cell population did not change for 24 hr after irradiation and then began exponential growth at a rate similar to that of control cells, also reaching stationary phase at 96 hr, but at a cell density of 0.93 x 10 6 cells/ml, which is less than half the maximum density of controls. From 24 to 96 hr after treatment, the x-irradiated cells were characterized by an increased consumption of oxygen that was nearly twice the amount utilized by control cells. The pH of the cell growth medium increases over 96 hr from 6.3 to 6.6 for irradiated as well as for untreated cultures, but since the number of x-rayed cells is less than half the number of untreated cells, the pH increase, per cell, of medium from irradiated cultures is about twice that of medium from control cultures

  2. Expression of UV-irradiated adenovirus in normal and UV-sensitive Chinese hamster ovary cells

    International Nuclear Information System (INIS)

    Rainbow, A.J.

    1985-01-01

    The chinese hamster ovary (CHO) cell mutants UV-20, UV-24, and UV-41 are abnormally sensitive to UV and harbour various defects lin their ability to repair cellular DNA. This study has examined the expression of UV-irradiated AD2 in these cells. HCR of UV-irradiated Ad2, as measured by viral structural antigen (Vag) formation or progeny production, was found to be similar for the normal and the UV-sensitive CHO strains. UV-irradiation of Ad2 (1200 J/m/sup 2/) resulted in a delay of Vag expression of 18 hours in normal human fibroblasts, which is thought to reflect the time required for removal of UV-induced lesions from the DNA before viral DNA synthesis can proceed. However, a similar UV-irradiation of Ad2 did not result in a delay of Vag expression for infection of CHO cells, suggesting that UV-induced lesions in Ad2 DNA do not inhibit its replication in CHO cells. These results indicate a fundamental difference in the processing of UV-irradiated AD2-DNA in CHO as compared to human cells

  3. Presence of UV-endonuclease sensitive sites in daughter DNA of UV-irradiated mammalian cells

    International Nuclear Information System (INIS)

    D'Ambrosio, S.; Setlow, R.B.

    1978-02-01

    Asynchronous Chinese hamster cells were irradiated with 10 Jm -2 uv radiation and 0.25 to 4 hours later pulse-labeled with [ 3 H]thymidine. Cells synchronized by shaking off mitotic and G 1 cells were irradiated in either the G 1 -phase or S-phase of the cell cycle and pulse-labeled with [ 3 H]thymidine in the S-phase. After a 12 to 14 hour chase in unlabeled medium, the DNA was extracted, incubated with Micrococcus luteus uv-endonuclease and sedimented in alkaline sucrose. The number of endonuclease sensitive sites decreased as the time between uv irradiation and pulse-labeling of daughter DNA increased. Further, there were significantly less endonuclease sensitive sites in the daughter DNA from cells irradiated in the G 1 -phase than in the S-phase. These data indicate that very few, if any, dimers are transferred from parental DNA to daughter DNA and that the dimers detected in daughter DNA may be due to the irradiation of replicating daughter DNA before labeling

  4. Temporally distinct response of irradiated normal human fibroblasts and their bystander cells to energetic heavy ions

    International Nuclear Information System (INIS)

    Hamada, Nobuyuki; Ni, Meinan; Funayama, Tomoo; Sakashita, Tetsuya; Kobayashi, Yasuhiko

    2008-01-01

    Ionizing radiation-induced bystander effects have been documented for a multitude of endpoints such as mutations, chromosome aberrations and cell death, which arise in nonirradiated bystander cells having received signals from directly irradiated cells; however, energetic heavy ion-induced bystander response is incompletely characterized. To address this, we employed precise microbeams of carbon and neon ions for targeting only a very small fraction of cells in confluent fibroblast cultures. Conventional broadfield irradiation was conducted in parallel to see the effects in irradiated cells. Exposure of 0.00026% of cells led to nearly 10% reductions in the clonogenic survival and twofold rises in the apoptotic incidence regardless of ion species. Whilst apoptotic frequency increased with time up to 72 h postirradiation in irradiated cells, its frequency escalated up to 24 h postirradiation but declined at 48 h postirradiation in bystander cells, indicating that bystander cells exhibit transient commitment to apoptosis. Carbon- and neon-ion microbeam irradiation similarly caused almost twofold increments in the levels of serine 15-phosphorylated p53 proteins, irrespective of whether 0.00026, 0.0013 or 0.0066% of cells were targeted. Whereas the levels of phosphorylated p53 were elevated and remained unchanged at 2 h and 6 h postirradiation in irradiated cells, its levels rose at 6 h postirradiation but not at 2 h postirradiation in bystander cells, suggesting that bystander cells manifest delayed p53 phosphorylation. Collectively, our results indicate that heavy ions inactivate clonogenic potential of bystander cells, and that the time course of the response to heavy ions differs between irradiated and bystander cells. These induced bystander responses could be a defensive mechanism that minimizes further expansion of aberrant cells

  5. Effects of fotemustine or dacarbasine on a melanoma cell line pretreated with therapeutic proton irradiation

    Directory of Open Access Journals (Sweden)

    Privitera Giuseppe

    2009-04-01

    Full Text Available Abstract Background Considering that HTB140 melanoma cells have shown a poor response to either protons or alkylating agents, the effects of a combined use of these agents have been analysed. Methods Cells were irradiated in the middle of the therapeutic 62 MeV proton spread out Bragg peak (SOBP. Irradiation doses were 12 or 16 Gy and are those frequently used in proton therapy. Four days after irradiation cells were treated with fotemustine (FM or dacarbazine (DTIC. Drug concentrations were 100 and 250 μM, values close to those that produce 50% of growth inhibition. Cell viability, proliferation, survival and cell cycle distribution were assessed 7 days after irradiation that corresponds to more than six doubling times of HTB140 cells. In this way incubation periods providing the best single effects of drugs (3 days and protons (7 days coincided at the same time. Results Single proton irradiations have reduced the number of cells to ~50%. FM caused stronger cell inactivation due to its high toxicity, while the effectiveness of DTIC, that was important at short term, almost vanished with the incubation of 7 days. Cellular mechanisms triggered by proton irradiation differently influenced the final effects of combined treatments. Combination of protons and FM did not improve cell inactivation level achieved by single treatments. A low efficiency of the single DTIC treatment was overcome when DTIC was introduced following proton irradiation, giving better inhibitory effects with respect to the single treatments. Most of the analysed cells were in G1/S phase, viable, active and able to replicate DNA. Conclusion The obtained results are the consequence of a high resistance of HTB140 melanoma cells to protons and/or drugs. The inactivation level of the HTB140 human melanoma cells after protons, FM or DTIC treatments was not enhanced by their combined application.

  6. Calibration of gamma cell 220 excel irradiator using Fricke and alanine dosimeters

    International Nuclear Information System (INIS)

    Rushdi, M. A. H.

    2006-06-01

    Using of gamma cell 220 excel irradiators is widely spread in many countries. This type of irradiators is being used for research purposes. Gamma cell 220 excel was provided by the International Atomic Energy Agency (IAEA) to the radiation processing laboratory of Sudan Atomic Energy Commission (SAEC). It is a self-contained gamma irradiator and self shielded, this makes it operates safely. Dose calibration for this cell is important for samples irradiation. In this work, a dosimetry system for the GC220E of SAEC was established using Fricke dosimeter. Fricke dosimeter has a confidence 95% in the rang not exceed 400 Gy. To establish routine dosimetry at high doses up to 5000 Gy, alanine dosimeter was used. This range can demonstrate the ability of GC220E to deliver known controllable doses in reproducible manner for high doses. The irradiation specifications often include a lower and upper limit of absorbed dose or central target dose. Absorbed dose mapping was carried out by both dosimeters to determine the magnitude and locations of D.max and D.min in the irradiation chamber. The results are in good agreement with dose distribution given in the machine manual. A comparison between the tow dosimeters was done and explained.(Author)

  7. Interaction between x-irradiated plateau-phase bone marrow stromal cell lines and co-cultivated factor-dependent cell lines leading to leukemogenesis in vitro

    International Nuclear Information System (INIS)

    Naparstek, E.; Anklesaria, P.; FitzGerald, T.J.; Sakakeeny, M.A.; Greenberger, J.S.

    1987-01-01

    Plateau-phase mouse clonal bone marrow stromal cell lines D2XRII and C3H cl 11 produce decreasing levels of M-CSF (CSF-1), a specific macrophage progenitor cell humoral regulator, following X-irradiation in vitro. The decrease did not go below 40% of control levels, even after irradiation doses of 50,000 rad (500 Gy). In contrast, a distinct humoral regulator stimulating growth of GM-CSF/IL-3 factor-dependent (FD) hematopoietic progenitor cell lines was detected following radiation to doses above 2000 rad. This humoral factor was not detectable in conditioned medium from irradiated cells, weakly detected using factor-dependent target cell populations in agar overlay, and was prominently detected by liquid co-cultivation of factor-dependent cells with irradiated stromal cell cultures. Subclonal lines of FD cells, derived after co-cultivation revealed karyotypic abnormalities and induced myeloblastic tumors in syngeneic mice. Five-eight weeks co-cultivation was required for induction of factor independence and malignancy and was associated with dense cell to cell contact between FD cells and stromal cells demonstrated by light and electron microscopy. Increases in hematopoietic to stromal cell surface area, total number of adherent cells per flask, total non-adherent cell colonies per flask, and cumulative non-adherent cell production were observed after irradiation. The present data may prove very relevant to an understanding of the cell to cell interactions during X-irradiation-induced leukemia

  8. Measurement of DNA-protein crosslinks in mammalian cells without X-irradiation

    International Nuclear Information System (INIS)

    Gantt, R.; Stephens, E.V.; Davis, S.R.

    1985-01-01

    To study the mechanisms of formation and repair of DNA-protein crosslinks in mammalian cells, the best general method to assay these lesions is the Kohn membrane alkaline elution procedure. Use of this sensitive technique requires the introduction of random strand breaks in the DNA by X-irradiation to reduce the very high molecular weight so that it elutes off the filter at an appropriate rate. This report describes an alternative method for fragmenting the DNA in the absence of X-irradiation equipment. Convenient reproducible elution rates of DNA from various mouse and human cells in culture without X-irradiation result from elution through polyvinyl chloride filters with 75 mM sodium hydroxide (0.33 ml/min) instead of the standard 20 mM EDTA-tetrapropylammonium hydroxide, pH 12.2 (0.03 to 0.04 ml/min). Dose-dependent retardation of the DNA elution was observed over the range 0 to 30 microM trans-platinum(II)diamminedichloride, and proteinase K treatment during cell lysis restored the elution rate to that of the untreated control cell DNA. In the absence of X-irradiation, this elution method measures DNA-protein crosslinks with higher sensitivity and equivalent reproducibility as the air-burst procedure

  9. The effect of vitamin E on cellular survival after X irradiation of lymphoma cells

    International Nuclear Information System (INIS)

    Fonck, K.; Kronings, A.W.T.

    1978-01-01

    Asynchronous cultures of a lymphocytic mouse leukaemic cell line L5178Y were X-irradiated under oxic and hypoxic conditions. The survival curves had almost no shoulder when the cells were grown under normal conditions and then irradiated in the presence of vitamin E, whereas a clear shoulder appeared when the cells were grown and irradiated in a medium supplemented with vitamin E (100 μg/ml). There was no change in the final sensitivity to lethal events in the vitamin E enriched cells. The results suggest that the radioprotective effect of vitamin E depends on its incorporation into the cell membranes. (U.K.)

  10. Studies on cross-immunity among syngeneic tumors by immunization with gamma-irradiated tumor cells

    International Nuclear Information System (INIS)

    Ito, Izumi

    1977-01-01

    In order to clarify whether cross-immunity among 3-methyl-cholanthrene (MCA)-induced sarcomas in C3H/He mice can be established or not, transplantations of syngeneic tumors were carried out in mice immunized with gamma-irradiated (13,000 rad 60 Co) tumor cells and in those immunized with living tumor cells thereafter. The following results were obtained. By using immunizing procedure with only gamma-irradiated tumor cells, a pair of tumors originating from one and the same mouse showed cross-resistance to each other. However, no such evidence was seen among tumors originating from different mice. Cross-immunity among syngeneic tumors originating from different mice could be clearly observed, when immunizing procedure using living tumor cells was added after the treatment with gamma-irradiated tumor cells. It was considered that common antigenicity among MCA-induced sarcoma cells was decreased by gamma-irradiation and that individual differences of tumor antigenecity were shown distinctly under such conditions. (auth.)

  11. Effect of front and rear incident proton irradiation on silicon solar cells

    Science.gov (United States)

    Anspaugh, Bruce; Kachare, Ram

    1987-01-01

    Four solar cell types of current manufacture were irradiated through the front and rear surfaces with protons in the energy range between 1 and 10 MeV. The solar cell parameters varied for this study were cell thickness and back surface field (BSF) vs. no BSF. Some cells were irradiated at normal incidence and an equal number were irradiated with simulated isotropic fluences. The solar cell electrical characteristics were measured under simulated AM0 illumination after each fluence. Using the normal incidence data, proton damage coefficients were computed for all four types of cells for both normal and omnidirectional radiation fields. These were found to compare well with the omnidirectional damage coefficients derived directly from the rear-incidence radiation data. Similarly, the rear-incidence omnidirectional radiation data were used to compute appropriate damage coefficients. A method for calculating the effect of a spectrum of energies is derived from these calculations. It is suitable for calculating the degradation of cells in space when they have minimal rear-surface shielding.

  12. Neoplastic transformation of hamster embryo cells irradiated in utero and assayed in vitro

    International Nuclear Information System (INIS)

    Borek, C.; Pain, C.; Mason, H.

    1977-01-01

    It is stated that induction of neoplastic transformation in vitro by x-rays and neutrons has been reported, and the authors had previously found that transformation by x-rays could be detected at doses as low as 1 R and the rate of transformation increased with dose, reaching a peak of 1% between 150 and 300 R. This frequency of neoplastic transformation in vitro is much higher than the frequency of radiation induced tumors observed after exposing animals to similar doses of radiation. Studies are here reported showing that malignant transformed cells can be obtained from embryos irradiated in utero and assayed in vitro, and that the frequency of transformation is at least tenfold lower than when the irradiations are performed in vitro, and thus closer to the incidence in animals. Hamster embryo cells were used for the studies. Questions that arise are as follows: does the host mediate in modulating transformation by radiation; is there a repair of transforming events before they can be expressed; and how significant is the state of cells during irradiation in determining the rate of transformation. It is known from in vitro studies that cell replication is required for fixation of the transformation. With the in vitro technique cells are seeded as single cells with ample opportunity to divide. In addition they are not in contact with one another, and constitute a mixture of cell types from many tissues. In utero the situation is quite different; the embryonic cells are irradiated as tissues where there is cell to cell contact in tissue-specific arrangements, and where the rate of cell replication varies with the tissue. It remains to be seen which of these factors, if any, is responsible for the lowered yield of transformed cells characteristic of in utero as opposed to in vitro irradiation. (U.K.)

  13. Frequency of polyploid cells in the bone marrow of rats fed irradiated wheat

    International Nuclear Information System (INIS)

    George, K.P.; Chaubey, R.C.; Sundaram, K.; Gopal-Ayengar, A.R.

    1976-01-01

    Diets containing different proportions of non-irradiated or irradiated wheat were fed to Wistar rats for 1 or 6 wk. Cytological analysis of the bone marrow showed no significant difference in the frequency of polyploid cells in the rats fed non-irradiated or irradiated wheat diets, even when the treated wheat was fed to the rats within 24 hr of irradiation. (author)

  14. Irradiation With Carbon Ion Beams Induces Apoptosis, Autophagy, and Cellular Senescence in a Human Glioma-Derived Cell Line

    International Nuclear Information System (INIS)

    Jinno-Oue, Atsushi; Shimizu, Nobuaki; Hamada, Nobuyuki; Wada, Seiichi; Tanaka, Atsushi; Shinagawa, Masahiko; Ohtsuki, Takahiro; Mori, Takahisa; Saha, Manujendra N.; Hoque, Ariful S.; Islam, Salequl; Kogure, Kimitaka; Funayama, Tomoo; Kobayashi, Yasuhiko

    2010-01-01

    Purpose: We examined biological responses of human glioma cells to irradiation with carbon ion beams (C-ions). Methods and Materials: A human glioma-derived cell line, NP-2, was irradiated with C-ions. Apoptotic cell nuclei were stained with Hoechst 33342. Induction of autophagy was examined either by staining cells with monodansylcadaverine (MDC) or by Western blotting to detect conversion of microtuble-associated protein light chain 3 (MAP-LC3) (LC3-I) to the membrane-bound form (LC3-II). Cellular senescence markers including induction of senescence-associated β-galactosidase (SA-β-gal) were examined. The mean telomere length of irradiated cells was determined by Southern blot hybridization. Expression of tumor suppressor p53 and cyclin/cyclin-dependent kinase inhibitor p21 WAF1/CIP1 in the irradiated cells was analyzed by Western blotting. Results: When NP-2 cells were irradiated with C-ions at 6 Gy, the major population of the cells died of apoptosis and autophagy. The residual fraction of attached cells ( WAF1/CIP1 was induced in NP-2 cells after irradiation. Furthermore, we found that irradiation with C-ions induced cellular senescence in a human glioma cell line lacking functional p53. Conclusions: Irradiation with C-ions induced apoptosis, autophagy, and cellular senescence in human glioma cells.

  15. Factors affecting ultraviolet-A photon emission from β-irradiated human keratinocyte cells.

    Science.gov (United States)

    Le, M; Mothersill, C E; Seymour, C B; Ahmad, S B; Armstrong, A; Rainbow, A J; McNeill, F E

    2015-08-21

    The luminescence intensity of 340±5 nm photons emitted from HaCaT (human keratinocyte) cells was investigated using a single-photon-counting system during cellular exposure to (90)Y β-particles. Multiple factors were assessed to determine their influence upon the quantity and pattern of photon emission from β-irradiated cells. Exposure of 1 x 10(4) cells/5 mL to 703 μCi resulted in maximum UVA photoemission at 44.8 x 10(3)±2.5 x 10(3) counts per second (cps) from live HaCaT cells (background: 1-5 cps); a 16-fold increase above cell-free controls. Significant biophoton emission was achieved only upon stimulation and was also dependent upon presence of cells. UVA luminescence was measured for (90)Y activities 14 to 703 μCi where a positive relationship between photoemission and (90)Y activity was observed. Irradiation of live HaCaT cells plated at various densities produced a distinct pattern of emission whereby luminescence increased up to a maximum at 1 x 10(4) cells/5 mL and thereafter decreased. However, this result was not observed in the dead cell population. Both live and dead HaCaT cells were irradiated and were found to demonstrate different rates of photon emission at low β activities (⩽400 μCi). Dead cells exhibited greater photon emission rates than live cells which may be attributable to metabolic processes taking place to modulate the photoemissive effect. The results indicate that photon emission from HaCaT cells is perturbed by external stimulation, is dependent upon the activity of radiation delivered, the density of irradiated cells, and cell viability. It is postulated that biophoton emission may be modulated by a biological or metabolic process.

  16. Chemical inhibition of cell recovery after irradiation with sparsely and densely ionizing radiation

    Energy Technology Data Exchange (ETDEWEB)

    Evastratova, Ekaterina S.; Petin, Vladislav [A. Tsyb Medical Radiological Research Centre-branch of the National Medical Research Radiological Centre of the Ministry of Health of the Russian Federation, Obninsk (Russian Federation); Kim, Jin Hong; Kim, Jin Kyu [Korea Atomic Energy Research Institute, Advanced Radiation Technology Institute (ARTI), Jeongeup (Korea, Republic of); Lim, Youg Khi [Dept. of Radiological Science, Gachon University, Incheon (Korea, Republic of)

    2017-02-15

    The dependence of cell survival on exposure dose and the duration of the liquid holding recovery (LHR) was obtained for diploid yeast cells irradiated with ionizing radiation of different linear energy transfer (LET) and recovering from radiation damage without and with various concentrations of cisplatin - the most widely used anticancer drug. The ability of yeast cells to recover from radiation damage was less effective after cell exposure to high-LET radiation, when cells were irradiated without drug. The increase in cisplatin concentration resulted in the disappearance of this difference whereas the fraction of irreversible damage was permanently enlarged independently of radiation quality. The probability of cell recovery was shown to be constant for various conditions of irradiation and recovery. A new mechanism of cisplatin action was suggested according with which the inhibition of cell recovery after exposure to ionizing radiations was completely explained by the production of irreversible damage.

  17. Chemical inhibition of cell recovery after irradiation with sparsely and densely ionizing radiation

    International Nuclear Information System (INIS)

    Evastratova, Ekaterina S.; Petin, Vladislav; Kim, Jin Hong; Kim, Jin Kyu; Lim, Youg Khi

    2017-01-01

    The dependence of cell survival on exposure dose and the duration of the liquid holding recovery (LHR) was obtained for diploid yeast cells irradiated with ionizing radiation of different linear energy transfer (LET) and recovering from radiation damage without and with various concentrations of cisplatin - the most widely used anticancer drug. The ability of yeast cells to recover from radiation damage was less effective after cell exposure to high-LET radiation, when cells were irradiated without drug. The increase in cisplatin concentration resulted in the disappearance of this difference whereas the fraction of irreversible damage was permanently enlarged independently of radiation quality. The probability of cell recovery was shown to be constant for various conditions of irradiation and recovery. A new mechanism of cisplatin action was suggested according with which the inhibition of cell recovery after exposure to ionizing radiations was completely explained by the production of irreversible damage

  18. 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.

  19. Irradiation effects of ultraviolet rays on Leptospira cells. Loss of motility, survive ability, and damages of cell structures

    Energy Technology Data Exchange (ETDEWEB)

    Maeda, Hidezo (Yamaguchi Univ., Ube (Japan). School of Medicine)

    1982-12-01

    The irradiation effects of ultraviolets rays (UV) on leptospira cells were investigated. Four serovar strains of Genus Leptospira ; L. copenhageni, L. canicola, L. biflexa and L. illini were used. A sterilization lamp (Toshiba-GL-15) was lighted at intervals of 90mm on the sample fluid for several minutes. Loss of motility, survival growth and morphological damages were recognized under several conditions. The medium conditions were important, that is, the Korthof's medium was less effective than phosphate buffered saline (PBS). The irradiation time was also important, that is, L. canicola cells in PBS lost their motility and survive ability within 300sec. of irradiation, however, much more time, such as 1.200sec. was necessary in Korthof's medium. This phenomenon may be depended upon defensibility of albumin in the latter. Among the strains, L. biflexa cells showed the highest resistance in loss of motility and survive ability, and other three strains were inferior. The remarkable efects of cellular structures were also seen in the materials with 30 min. of irradiation, in both immediate time or after 24h incubation. The damages observed after 24th of irradiation were much more drastic than those of immediate time. No effect could be seen on the cells suspended in the Korthof's medium irradiated for 24h. Regarding morphological effect, there appeared relaxation of helical body, spherical body and semighost as the immediate changes. Structural damages were recognized as the collapse of cell body, such as scattering of capsule, release of axial flagella, loss or change of cytoplasmic density and break down of wall membrane complex. These phenomena were regarded as the indirect effects of UV-irradiation and autolysis in a post-mortem change.

  20. Leptin induction following irradiation is a conserved feature in mammalian epithelial cells and tissues.

    Science.gov (United States)

    Licursi, Valerio; Cestelli Guidi, Mariangela; Del Vecchio, Giorgia; Mannironi, Cecilia; Presutti, Carlo; Amendola, Roberto; Negri, Rodolfo

    2017-09-01

    Leptin (LEP) is a peptide hormone with multiple physiological functions. Besides its systemic actions, it has important peripheral roles such as a mitogen action on keratinocytes following skin lesions. We previously showed that LEP mRNA is significantly induced in response to neutron irradiation in mouse skin and that the protein increases in the irradiated epidermis and in the related subcutaneous adipose tissue. In this work, we investigated the post-transcriptional regulation of LEP by miRNAs and the conservation of LEP's role in radiation response in human cells. We used microarray analysis and real-time polymerase chain reaction (RT-PCR) to analyze modulation of miRNAs potentially targeting LEP in mouse skin following irradiation and bioinformatic analysis of transcriptome of irradiated human cell lines and cancer tissues from radiotherapy-treated patients to evaluate LEP expression. We show that a network of miRNAs potentially targeting LEP mRNA is modulated in irradiated mouse skin and that LEP itself is significantly modulated by irradiation in human epithelial cell lines and in breast cancer tissues from radiotherapy-treated patients. These results confirm and extend the previous evidence that LEP has a general and important role in the response of mammalian cells to irradiation.

  1. Effects of ultraviolet irradiation on the cell cycle in normal and UV-sensitive cell lines with reference to the nature of the defect in xeroderma pigmentosum variant

    International Nuclear Information System (INIS)

    Imray, P.; Mangan, T.; Saul, A.; Kidson, C.

    1983-01-01

    Analysis of the distribution of cells through the phases of the cell cycle by DNA flow cytofluorimetry has been utilized to investigate the effects of ultraviolet (UV) irradiation on cell-cycle progression in normal and UV-sensitive lymphoblastoid cell lines. In time-course studies only slight perturbation of DNA distribution was seen in normal cells, or UV-sensitive familial melanoma (FM) lines in the 48 h following irradiation. Xeroderma pigmentosum (XPA) excision-deficient cells showed a large increase in the proportion of cells in S phase 16-40 h post-irradiation. XP variant (XPV) cells were blocked in G 1 and S phases with the complete absence of cells with G 2 DNA content 16-28 h after irradiation. By 48 h post-irradiation the DNA distribution of XPA and XPV cells had returned to that of an unirradiated control. When colcemid was added to the cultures immediately after irradiation to prevent mitotic cells dividing and re-entering the cell cycle, progression through the first cycle after irradiation was followed. UV irradiation did not affect the rate of movement of cells out of G 1 into S phase in normal, FM or XPA cells. The proportion of cells in S phase was increased in UV-irradiated cultures in these cell types and the number of cells entering the G 2 +M compartment was reduced. (orig./AJ)

  2. Cell kinetics of irradiated experimental tumors: cell transition from the non-proliferating to the proliferating pool

    International Nuclear Information System (INIS)

    Potmesil, M.; Goldfeder, A.

    1980-01-01

    In murine mammary carcinomas, parenchymal tumor cells with dense nucleoli traverse the cell cycle and divide, thus constituting the proliferating pool. Cells with trabeculate or ring-shaped nucleoli either proceed slowly through G 1 phase or are arrested in it. The role of these non-proliferating, G 1 phase-confined cells in tumor regeneration was studied in vivo after a subcurative dose of X-irradiation in two transplantable tumor lines. Tumor-bearing mice were continuously injected with methyl[ 3 H]thymidine before and after irradiation. Finally, the labeling was discontinued, mice injected with vincristine sulfate and cells arrested in metaphase were accumulated over 10-hrs. Two clearly delineated groups of vincristine-arrested mitoses emerged in autoradiograms prepared from tumor tissue at the time of starting tumor regrowth: one group with the silver-grain counts corresponding to the background level, the other with heavily labeled mitoses. As the only source of unlabeled mitoses was unlabeled G 1 phase-confined cells persisting in the tumor, this indicated cell transition from the non-proliferating to the proliferating pool, which took place in the initial phase of the tumor regrowth. Unlabeled progenitors have apparently remained in G 1 phase for at least 5-12 days after irradiation. (author)

  3. Effect of irradiation on the acinar cells of submandibular gland in streptozotocin-induced diabetic rats

    International Nuclear Information System (INIS)

    Lee, Seung Hyun; Hwang, Eui Hwan; Lee, Sang Rae

    2003-01-01

    To observe the histologic changes and clusterin expression in the acinar cells of the submandibular gland in streptozotocin-induced diabetic rat following irradiation. Mature Sprague-Dawley rats were divided into three groups: control, diabetic, and diabetic-irradiated groups. Diabetes mellitus was induced in the Sprague-Dawley rats by injecting streptozotocin, while the control rats were injected with citrate buffer only. After 5 days, rats in diabetic-irradiated group were irradiated with single absorbed dose of 10 Gy to the head and neck region. The rats were killed at 1, 3, 7, 14, 21, and 28 days after irradiation. The specimen including the submandibular gland were sectioned and observed using histologic and immunohistochemical methods. Morphologic change of acinar cells was remarkable in the diabetic group, but was not observed in the diabetic-irradiated group. Necrotic tissues were observed in the diabetic-irradiated group. Coloring of toluidine blue stain was most increased at 14 days in the diabetic group, however there were no significant change throughout the period of the experiment in the diabetic-irradiated group. Expression of clusterin was most significant at 14 days in the diabetic group, but gradually decreased with time after 7 days in the diabetic-irradiated group. Degeneration of clusterin was observed in the diabetic-irradiated group. This experiment suggests that the acinar cells of submandibular gland in rats are physiologically apoptosis by the induction of diabetes, but that the apoptosis is inhibited and the acinar cells necrotized after irradiation.

  4. The use of computerized video time lapse to study cell death in rat embryo cells transfected with c-ha-ras or c-myc

    International Nuclear Information System (INIS)

    Forrester, H.B.; Vidair, C.A.; Dewey, W.C.; Ling, C.C.

    1998-01-01

    Full text: Individual rat embryo fibroblasts that had been transfected with the c-myc (REC:myc) or c-Ha ras (REC:ras) oncogene were followed after irradiation using a computer video time lapse (CVTL) system in order to quantify the lethal events that resulted in loss of clonogenic survival after irradiation. By followed the cells for 2 to 3 generations before irradiation we were able to determine where they were in the cell cycle at the time of irradiation for cell cycle analysis. After irradiation, the individual cells and their progeny were followed in multiple fields for 5-6 days Then, pedigrees for individual irradiated cells were determined by noting the times of divisions fusions, and cell death. After X-irradiation, the clonogenic survival values for these two cell lines are similar. However, by using computerized video time lapse (CVTL) to follow individual cells we found that the loss of clonogenic survival was due to two different processes, cell death and a senescent-like process. The loss of clonogenic survival of x-irradiated (9.5 and 4 Gy) REC:myc cells was attributed almost entirely to the cells dying by apoptosis (∼99 and 90%). In contrast, approximately 60% of the x-irradiated (9.5 Gy) non-clonogenic REC:ras cells died by apoptosis (with a very small amount of necrosis), and the other 40% underwent a senescent-type process in which some of the cells and their progeny stopped dividing but remained as viable cells throughout 140 hours of observation. Both processes usually occurred after the cells had divided and continued to occur in the cells' progeny for up to five divisions after irradiation. The mode of cell death in the progeny of a non-clonogenic cell can be determined only by using CVTL and can not be determined by conventional clonogenic survival experiments. Also, only by following the individual cells and their progeny can the true amount of apoptosis be determined. The cumulative percentage of apoptosis scored in whole populations

  5. Investigation of the bystander effect in MRC5 cells after acute and fractionated irradiation in vitro

    International Nuclear Information System (INIS)

    Soleymanifard, Shokouhozaman; Toossi, Mohammad Taghi Bahreyni; Samani, Roghayeh Kamran; Mohebbi, Shokoufeh

    2014-01-01

    Radiation-induced bystander effect (RIBE) has been defined as radiation responses observed in nonirradiated cells. It has been the focus of investigators worldwide due to the deleterious effects it induces in nonirradiated cells. The present study was performed to investigate whether acute or fractionated irradiation will evoke a differential bystander response in MRC5 cells. A normal human cell line (MRC5), and a human lung tumor cell line (QU-DB) were exposed to 0, 1, 2, and 4Gy of single acute or fractionated irradiation of equal fractions with a gap of 6 h. The MRC5 cells were supplemented with the media of irradiated cells and their micronucleus frequency was determined. The micronucleus frequency after single and fractionated irradiation did not vary significantly in the MRC5 cells conditioned with autologous or QU-DB cell-irradiated media, except for 4Gy where the frequency of micronucleated cells was lower in those MRC5 cells cultured in the media of QU-DB-exposed with a single dose of 4Gy. Our study demonstrates that the radiation-induced bystander effect was almost similar after single acute and fractionated exposure in MRC5 cells. (author)

  6. Investigation of the bystander effect in MRC5 cells after acute and fractionated irradiation in vitro

    Directory of Open Access Journals (Sweden)

    Shokouhozaman Soleymanifard

    2014-01-01

    Full Text Available Radiation-induced bystander effect (RIBE has been defined as radiation responses observed in nonirradiated cells. It has been the focus of investigators worldwide due to the deleterious effects it induces in nonirradiated cells. The present study was performed to investigate whether acute or fractionated irradiation will evoke a differential bystander response in MRC5 cells. A normal human cell line (MRC5, and a human lung tumor cell line (QU-DB were exposed to 0, 1, 2, and 4Gy of single acute or fractionated irradiation of equal fractions with a gap of 6 h. The MRC5 cells were supplemented with the media of irradiated cells and their micronucleus frequency was determined. The micronucleus frequency after single and fractionated irradiation did not vary significantly in the MRC5 cells conditioned with autologous or QU-DB cell-irradiated media, except for 4Gy where the frequency of micronucleated cells was lower in those MRC5 cells cultured in the media of QU-DB-exposed with a single dose of 4Gy. Our study demonstrates that the radiation-induced bystander effect was almost similar after single acute and fractionated exposure in MRC5 cells.

  7. Photoluminescence in large fluence radiation irradiated space silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Hisamatsu, Tadashi; Kawasaki, Osamu; Matsuda, Sumio [National Space Development Agency of Japan, Tsukuba, Ibaraki (Japan). Tsukuba Space Center; Tsukamoto, Kazuyoshi

    1997-03-01

    Photoluminescence spectroscopy measurements were carried out for silicon 50{mu}m BSFR space solar cells irradiated with 1MeV electrons with a fluence exceeding 1 x 10{sup 16} e/cm{sup 2} and 10MeV protons with a fluence exceeding 1 x 10{sup 13} p/cm{sup 2}. The results were compared with the previous result performed in a relative low fluence region, and the radiation-induced defects which cause anomalous degradation of the cell performance in such large fluence regions were discussed. As far as we know, this is the first report which presents the PL measurement results at 4.2K of the large fluence radiation irradiated silicon solar cells. (author)

  8. Expression profiles are different in carbon ion-irradiated normal human fibroblasts and their bystander cells

    International Nuclear Information System (INIS)

    Iwakawa, Mayumi; Hamada, Nobuyuki; Imadome, Kaori; Funayama, Tomoo; Sakashita, Testuya; Kobayashi, Yasuhiko; Imai, Takashi

    2008-01-01

    Evidence has accumulated that ionizing radiation induces biological effects in non-irradiated bystander cells having received signals from directly irradiated cells; however, energetic heavy ion-induced bystander response is incompletely characterized. Here we performed microarray analysis of irradiated and bystander fibroblasts in confluent cultures. To see the effects in bystander cells, each of 1, 5 and 25 sites was targeted with 10 particles of carbon ions (18.3 MeV/u, 103 keV/μm) using microbeams, where particles traversed 0.00026, 0.0013 and 0.0066% of cells, respectively. diated cells, cultures were exposed to 10% survival dose (D), 0.1D and 0.01D of corresponding broadbeams (108 keV/μm). Irrespective of the target numbers (1, 5 or 25 sites) and the time (2 or 6 h postirradiation), similar expression changes were observed in bystander cells. Among 874 probes that showed more than 1.5-fold changes in bystander cells, 25% were upregulated and the remainder downregulated. These included genes related to cell communication (PIK3C2A, GNA13, FN1, ANXA1 and IL1RAP), stress response (RAD23B, ATF4 and EIF2AK4) and cell cycle (MYCN, RBBP4 and NEUROG1). Pathway analysis revealed serial bystander activation of G protein/PI-3 kinase pathways. Instead, genes related to cell cycle or death (CDKN1A, GADD45A, NOTCH1 and BCL2L1), and cell communication (IL1B, TCF7 and ID1) were upregulated in irradiated cells, but not in bystander cells. Our results indicate different expression profiles in irradiated and bystander cells, and imply that intercellular signaling between irradiated and bystander cells activate intracellular signaling, leading to the transcriptional stress response in bystander cells

  9. Functional Changes of Dendritic Cells in C6 Glioma-Bearing Rats That Underwent Combined Argon-Helium Cryotherapy and IL-12 Treatment.

    Science.gov (United States)

    Li, Ming; Cui, Yao; Li, Xiqing; Guo, Yanwu; Wang, Bin; Zhang, Jiadong; Xu, Jian; Han, Shuangyin; Shi, Xiwen

    2016-08-01

    The aim of this study was to explore changes in tumor tissues of glioma-bearing rats that underwent argon-helium cryoablation as well as changes in antitumor immunity before and after combined interleukin 12 treatment. Two hundred sixty Wistar rats were randomly divided into a blank control group, intravenous injection interleukin-12 group, cryotherapy group, and cryotherapy + intravenous injection group. C6 glioma cells proliferated in vitro were implanted subcutaneously on the backs of rats to establish C6 glioma-bearing animal models. Each group underwent the corresponding treatments, and morphological changes in tumor tissues were examined using hematoxylin-eosin staining. CD11c staining was examined using immunohistochemistry, and differences in dendritic cells and T-cell subsets before and after treatment were analyzed using flow cytometry. The control group showed no statistical changes in terms of tumor tissue morphology and cellular immunity, cryotherapy group, and cryotherapy + intravenous injection group, among which the count for the cryotherapy + intravenous injection group was significantly higher than those of all other groups. In the argon-helium cryotherapy group, tumor cells were damaged and dendritic cell markers were positive. The number of CD11c+ and CD86+ cells increased significantly after the operation as did the cytokine interferon-γ level (P < .01), suggesting a shift toward Th1-type immunity. Combined treatment of argon-helium cryoablation and interleukin 12 for gliomas not only effectively injured tumor tissues but also boosted immune function and increased antitumor ability. Therefore, this approach is a promising treatment measure for brain gliomas. © The Author(s) 2015.

  10. The combined effects of irradiation and herpes simplex virus type 1 infection on an immortal gingival cell line

    Science.gov (United States)

    2014-01-01

    Background Oral mucosa is frequently exposed to Herpes simplex virus type 1 (HSV-1) infection and irradiation due to dental radiography. During radiotherapy for oral cancer, the surrounding clinically normal tissues are also irradiated. This prompted us to study the effects of HSV-1 infection and irradiation on viability and apoptosis of oral epithelial cells. Methods Immortal gingival keratinocyte (HMK) cells were infected with HSV-1 at a low multiplicity of infection (MOI) and irradiated with 2 Gy 24 hours post infection. The cells were then harvested at 24, 72 and 144 hours post irradiation for viability assays and qRT-PCR analyses for the apoptosis-related genes caspases 3, 8, and 9, bcl-2, NFκB1, and viral gene VP16. Mann–Whitney U-test was used for statistical calculations. Results Irradiation improved the cell viability at 144 hours post irradiation (P = 0.05), which was further improved by HSV-1 infection at MOI of 0.00001 (P = 0.05). Simultaneously, the combined effects of infection at MOI of 0.0001 and irradiation resulted in upregulation in NFκB1 (P = 0.05). The combined effects of irradiation and HSV infection also significantly downregulated the expression of caspases 3, 8, and 9 at 144 hours (P = 0.05) whereas caspase 3 and 8 significantly upregulated in non-irradiated, HSV-infected cells as compared to uninfected controls (P = 0.05). Infection with 0.0001 MOI downregulated bcl-2 in non-irradiated cells but was upregulated by 27% after irradiation when compared to non-irradiated infected cells (P = 0.05). Irradiation had no effect on HSV-1 shedding or HSV gene expression at 144 hours. Conclusions HSV-1 infection may improve the viability of immortal cells after irradiation. The effect might be related to inhibition of apoptosis. PMID:25005804

  11. Evaluation of {sup 18}F-FDG and {sup 18}F-FLT for monitoring therapeutic responses of colorectal cancer cells to radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Hui [Nuclear Medicine Department, The General Hospital of the Chinese People' s Liberation Army and Military Medical Postgraduate College, Beijing 100853 (China); Liu, Bo [Department of Hepatobiliary Surgery, The General Hospital of the Chinese People' s Liberation Army and Military Medical Postgraduate College, Beijing 100853 (China); Tian, Jiahe, E-mail: tianjh@vip.sina.com [Nuclear Medicine Department, The General Hospital of the Chinese People' s Liberation Army and Military Medical Postgraduate College, Beijing 100853 (China); Xu, Baixuan; Zhang, Jinming [Nuclear Medicine Department, The General Hospital of the Chinese People' s Liberation Army and Military Medical Postgraduate College, Beijing 100853 (China); Qu, Baolin [Department of Radiation Oncology, The General Hospital of the Chinese People' s Liberation Army and Military Medical Postgraduate College, Beijing 100853 (China); Chen, Yingmao [Nuclear Medicine Department, The General Hospital of the Chinese People' s Liberation Army and Military Medical Postgraduate College, Beijing 100853 (China)

    2013-09-15

    In order to compare the efficacy of {sup 18}F-fluorothymidine (FLT) and {sup 18}F-fluorodeoxyglucose (FDG) for monitoring early responses to irradiation, two human colorectal cancer (CRC) cell lines SW480 and SW620, which were derived from the primary lesions and the metastatic lymph node, underwent X-ray irradiation of 0, 10, or 20 Gy and were examined at 0, 24 and 72 h After irradiation, reduced proliferation of both SW480 and SW620 cells was observed in a dose-dependent manner (P < 0.001), G0-G1 arrest was also noted in both cell types after 72 h in the 20 Gy group (P < 0.001). Although increased apoptosis was observed in both cell lines after irradiation (P < 0.001), a greater percentage of SW480 cells underwent apoptosis in response to irradiation than SW620 cells. Increased Hsp27 and decreased integrin β{sub 3}, Ki67 and VEGFR2 expression was observed over time via immunocytochemistry and Western blot analysis (P < 0.001), however, no significant changes were noted in response to irradiation. Finally, reduced uptake of {sup 18}F-FLT by SW480 or SW620 cells was observed at 24-h post-irradiation, however, reduced {sup 18}F-FDG uptake was only observed after 72 h. Therefore, we conclude that {sup 18}F-FLT is a more suitable positron emission tomography (PET) tracer for monitoring early responses to irradiation in primary and metastatic lymph node CRC cells.

  12. Adaptive changes in NAD+ metabolism in ultraviolet light-irradiated murine lymphoma cells

    International Nuclear Information System (INIS)

    Kleczkowska, H.E.; Szumiel, I.; Althaus, F.R.

    1990-01-01

    We have determined the ability of UV254nm-irradiated murine lymphoma cells to adapt their NAD+ metabolism to the increased NAD+ consumption for the poly ADP-ribosylation of chromatin proteins. Two murine lymphoma sublines with differential UV-sensitivity and poly(ADP-ribose) turnover were used as a model system. The first subline, designated LY-R is UV254nm-sensitive and tumorigenic in DBA/2 mice. The second subline, LY-S is UV254nm-resistant and nontumorigenic. Following treatment of these cells with 2 mM benzamide, an inhibitor of the NAD(+)-utilizing enzyme poly(ADP-ribose) polymerase, NAD+ levels slowly increased up to about 160% of control levels after 3 hours. When benzamide was added to these cultures 20 min after UV254nm irradiation, a dramatic transient increase of NAD+ levels was observed within 4 min in LY-R cells and more moderately in LY-S cells. At later times after UV254nm irradiation, the NAD+ levels increased in both sublines reaching up to 200% of the concentrations prior to benzamide treatment. These results demonstrate an adaptative response of NAD+ metabolism to UV254nm irradiation. In parallel, we observed a differential repartitioning of ADP-ribosyl residues between the NAD+ and poly(ADP-ribose) pools of LY-R and LY-S cells that correlates with the differential UV sensitivity of these cells

  13. Effect of continuous low-dose γ-irradiation on rat Sertoli cell function

    International Nuclear Information System (INIS)

    Kamtchouing, P.; Papadopoulos, V.; Drosdowsky, M.A.; Carreau, S.; Pinon-Lataillade, G.; Maas, J.; Guillaumin, J.M.; Bardos, P.; Perreau, C.; Hochereau de Reviers, M.T.

    1988-01-01

    Continuous low-dose γ-irradiation of mature rats induced a progressive degeneration of the germ cells. Blood FSH increased by 127, 176 and 214%, respectively, after 55, 70 and 85 days of treatment when compared to FSH levels in control rats (8.50 ± 0.60 ng/ml); conversely, serum LH and testosterone levels were unchanged. The Sertoli cell function was affected by the treatment from 70 days on, as attested by androgen binding protein (ABP) and transferrin secretions which diminished 35-40%. Serum ABP levels were not altered, whatever the duration of irradiation, even though epididymal ABP contents (as well as concentrations) diminished 34-60% when compared to those of the controls. Moreover, in purified Leydig cells, LH-stimulated intracellular cAMP levels, which were decreased by seminiferous tubule medium (STM) from control rats, were enhanced in presence of STM from treated animals. Testosterone output was stimulated 9-fold in presence of oLH and further increased (46-76%) from stages XIV-V by STM prepared from control and irradiated rats, respectively. After 85 days the STM effects on both cAMP and testosterone syntheses were zero. These results demonstrate a probable alteration of Sertoli cell function after irradiation, but also a role of the germ cells in the regulation of the synthesis of ABP, transferrin and Sertoli cell paracrine factors

  14. Analysis of cell kinetics after gamma ray irradiation using anti-BrdU monoclonal antibody

    International Nuclear Information System (INIS)

    Akagi, Kiyoshi; Tanaka, Yoshimasa

    1989-01-01

    The cell cycle was analyzed using anti-BrdU monoclonal antibody, and changes in cell kinetics after gamma ray irradiation as evaluated by this BrdU-PI double staining were compared with those evaluated by the DNA histogram method based on PI staining. The effect of irradiation on the cell kinetics has been studied according primarily to the number of G2 blocked cells. By the present BrdU method, rapid transition of the G1-S phase was observed within 2 hours of irradiation, and then G1 block was observed. Cells in the S phase progressed to the G2 + M cells returned to the G1 phase after 18 or more hours. These initial G1 blocked cells induced by irradiation were confirmed for the fist time by the present BrdU-PI double staining. By the conventional method based on the DNA histogram, accurate determination of S cell fraction was difficult due to overlapping of the DNA contents of G1 cells and early S cells and those of late S cells and G2 cells. On the other hand, BrdU-PI double staining allowed direct differentiation of G1, S, and G2 + M cells, especially between G1-S and S-G2 + M cells. The analysis of cell kinetics using BrdU is advantageous over the conventional autoradiographic methods in that it allowed more rapid assay with very high sensitivity. In addition, BrdU is alrady used clinically as an enhancement agent in radiation therapy for cancer. The present method is considered to be indispensable for evaluation of the percentage of S cells in the tumor tissue and analysis of cell kinetics after irradiation and chemotherapy against cancer. (author)

  15. Effects of irradiation on the expression of the adhesion molecules (NCAM, ICAM-1) by glioma cell lines

    Energy Technology Data Exchange (ETDEWEB)

    Yamanaka, Ryuya; Tanaka, Ryuichi; Yoshida, Seiichi [Niigata Univ. (Japan). Brain Research Inst.

    1993-11-01

    The expression of the intercellular adhesion molecule-1 (ICAM-1) and neural cell adhesion molecule (NCAM) by glioma cell lines was investigated. The effects of interferon (IFN)-[gamma] or irradiation on the expression was also assessed. Two glioma cell lines showed more than 75% NCAM-positive cells. After treatment with IFN-[gamma] or irradiation, another three cell lines were induced to show more than 50% positive cells. Three glioma cell lines showed more than 50% ICAM-1-positive cells. After treatment with IFN-[gamma], another two cell lines were induced to show more than 50% positive cells. After treatment with irradiation, one more cell line was induced to show more than 50% positive cells. ICAM-1 and NCAM expression by glioma cell lines is susceptible to modulation by IFN-[gamma] or irradiation. (author).

  16. Biological X-ray irradiator characterization for use with small animals and cells.

    Science.gov (United States)

    Bruno, A Colello; Mazaro, S J; Amaral, L L; Rego, E M; Oliveira, H F; Pavoni, J F

    2017-03-02

    This study presents the characterization of an X-ray irradiator through dosimetric tests, which confirms the actual dose rate that small animals and cells will be exposed to during radiobiological experiments. We evaluated the linearity, consistency, repeatability, and dose distribution in the positions in which the animals or cells are placed during irradiation. In addition, we evaluated the performance of the X-ray tube (voltage and tube operating current), the radiometric survey (leakage radiation) and safety devices. The irradiator default setting was established as 160 kV and 25 mA. Tests showed that the dose rate was linear overtime (R2=1) and remained stable for long (constant) and short (repeatability) intervals between readings. The mean dose rate inside the animal cages was 1.27±0.06 Gy/min with a uniform beam of 95.40% (above the minimum threshold guaranteed by the manufacturer). The mean dose rate inside the cell plates was 0.92±0.19 Gy/min. The dose rate dependence with tube voltage and current presented a quadratic and linear relationship, respectively. There was no observed mechanical failure during evaluation of the irradiator safety devices and the radiometric survey obtained a maximum ambient equivalent dose rate of 0.26 mSv/h, which exempts it from the radiological protection requirements of the International Atomic Energy Agency. The irradiator characterization enables us to perform radiobiological experiments, and assists or even replaces traditional therapy equipment (e.g., linear accelerators) for cells and small animal irradiation, especially in early research stages.

  17. Biological X-ray irradiator characterization for use with small animals and cells

    Directory of Open Access Journals (Sweden)

    A. Colello Bruno

    Full Text Available This study presents the characterization of an X-ray irradiator through dosimetric tests, which confirms the actual dose rate that small animals and cells will be exposed to during radiobiological experiments. We evaluated the linearity, consistency, repeatability, and dose distribution in the positions in which the animals or cells are placed during irradiation. In addition, we evaluated the performance of the X-ray tube (voltage and tube operating current, the radiometric survey (leakage radiation and safety devices. The irradiator default setting was established as 160 kV and 25 mA. Tests showed that the dose rate was linear overtime (R2=1 and remained stable for long (constant and short (repeatability intervals between readings. The mean dose rate inside the animal cages was 1.27±0.06 Gy/min with a uniform beam of 95.40% (above the minimum threshold guaranteed by the manufacturer. The mean dose rate inside the cell plates was 0.92±0.19 Gy/min. The dose rate dependence with tube voltage and current presented a quadratic and linear relationship, respectively. There was no observed mechanical failure during evaluation of the irradiator safety devices and the radiometric survey obtained a maximum ambient equivalent dose rate of 0.26 mSv/h, which exempts it from the radiological protection requirements of the International Atomic Energy Agency. The irradiator characterization enables us to perform radiobiological experiments, and assists or even replaces traditional therapy equipment (e.g., linear accelerators for cells and small animal irradiation, especially in early research stages.

  18. Characterization of death of human fetal bone marrow CD34+ cells after different dose of γ-irradiation

    International Nuclear Information System (INIS)

    Xiang Yingsong; Yang Rujun; Tang Gusheng

    2001-01-01

    Objective: To investigate the characterization of death of the human hematopoietic stem cells after irradiation. Methods: Human fetal bone marrow mononuclear cells were irradiated with different doses of 60 Co γ-rays at different high dose rates. Apoptosis and necrosis of CD34 + cells were analyzed by flow cytometry, following three-color labelling with PE-CD34/FITC-Annexin V/7AAD at different times after irradiation. Results: The death of CD34 + cells after 5 Gy and 8 Gy irradiation showed a continuous process of reproductive death during the first week,and the main death type was apoptosis. A majority of CD34 + cells died of necrosis during the first day after 10 Gy and 12 Gy irradiation, and all of them died within a week. Conclusion: Niches are continuously vacated every day within a week following irradiation and reproductive death of hematopoietic stem cells occurred

  19. Enhancement of tumor cell killing in vitro by pre- and post-irradiation exposure to aclacinomycin A

    International Nuclear Information System (INIS)

    Bill, C.A.; Mendoza, A.; Vrdoljak, E.; Tofilon, P.J.

    1993-01-01

    Aclacinomycin A (ACM), a potent inducer of leukemic cell differentiation, significantly enhances the radiosensitivity of a human colon tumor cell line (Clone A) when cultures are exposed to 15-nM concentrations for 3 days before irradiation. We now demonstrate that incubation with ACM after irradiation can also enhance Clone A cell killing. The maximum increase in cell killing, based on colony-forming ability, occurred when Clone A cells were exposed for 1 h to 5 μM ACM model added 1 or 2 h after irradiation. The post-irradiation ACM protocol reduced the terminal slope (as reflected by D o ) of the radiation cell survival curve with no change in the low-dose, shoulder region of the curve (D q value). In contrast, for pre-irradiation treatment with ACM (15 nM, 3 days), the shoulder region of the curve was reduced with no change in the terminal slope. For pre- and post-irradiation ACM treatment the dose enhancement factors at 0.10 survival were 1.22 and 1.28, respectively. When ACM was given both before and after irradiation both the shoulder and terminal slope values decreased to produce a dose enhancement factor at a surviving fraction of 0.10 of 1.50. These data suggest that the enhanced cell killing produced by pre- and post-irradiation treatment with ACM is achieved through different mechanisms. (author) 26 refs., 3 tabs., 2 figs

  20. Effects of x-ray irradiation on mast cells and mastocalcergy in the connective tissue

    Energy Technology Data Exchange (ETDEWEB)

    Song, H. Y.; Rhee, S. J.; Son, M. H.; Choi, K. C. [Chonbuk National University College of Medicine, Jeonju (Korea, Republic of)

    1982-09-15

    Experiments were performed to observe the influence of x-ray irradiation on mast cells and mastocalcergy in rats. Animals were irradiated single dose of x-ray. X-ray irradiation was applied to the whole body in doses either 100 rads or 150 rads (Cobalt-60 Teletherapy Unit). One day after irradiation the rats were injected lead acetate intravenously, followed by injection of compound 48/80 in the back subcutaneously. Animals were killed by decapitation at intervals, 1 hour, 5 hours, 1 day and 6 day after subcutaneous injection. Specimens of the abdominal and back skin were fixed in alcohol formol solution and stained with the following methods; H-E for observation of pathological changes of tissues, toluidine blue for demonstration of mast cells, von Kossa-azure A for demonstration of carbonate and phosphate, and chloranilic acid for demonstration of calcium. The following conclusions were obtained. Calciphylatic wheals are large size in the control group, medium size in 100 rads irradiation group and small size in 150 rads irradiation group. In x-ray irradiation groups the number of mast cells decreases more in the 150 rads than in the 100 rads irradiation. In the 100 rads x-ray irradiation group, histochemical study of the injection sites showed that calcium impregnated to mast cell granules and connective tissue fibers in 1 days after subcutaneous injection. The morphogenesis of this calcinosis was the same in the rat of 5 hour after subcutaneous injection of the control group. Whereas, 1 day after subcutaneous injection in 150 rads x-ray irradiation group calcium deposited more slightly than other groups.

  1. {sup 197}Au irradiation study of phase-change memory cell with GeSbTe alloy

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Liangcai; Song, Zhitang; Lian, Jie; Rao, Feng; Liu, Bo; Song, Sannian; Liu, Weili; Feng, Songlin [State Key Laboratory of Functional Materials for Informatics, Laboratory of Nanotechnology, Shanghai Institute of Micro-system and Information Technology, Chinese Academy of Sciences, Shanghai 200050 (China); Zhou, Xilin; Liu, Xuyan [State Key Laboratory of Functional Materials for Informatics, Laboratory of Nanotechnology, Shanghai Institute of Micro-system and Information Technology, Chinese Academy of Sciences, Shanghai 200050 (China); Graduate School of the Chinese Academy of Sciences, Beijing 100080 (China)

    2010-10-15

    A {sup 197}Au ion source was used to irradiate a Ge{sub 2}Sb{sub 2}Te{sub 5}-alloy-based phase-change memory (PCM) cell to study the ion-irradiation effect on the properties of the cell. The PCM devices with the tungsten (W) heating electrode of 260 nm diameter were fabricated by 0.18 {mu}m complementary metal-oxide-semiconductor (CMOS) technology. Four different doses (10{sup 10}, 10{sup 11}, 10{sup 12}, and 5 x 10{sup 12} ions/cm{sup 2}, respectively) were applied to irradiate the PCM cell. The samples before and after irradiation were characterized by current-voltage and resistance measurements at room temperature. It is found that the cell properties (resistance value of the amorphous and crystalline states, threshold voltage, and current for phase transition, etc.) have hardly changed, even for the sample irradiated up to 10{sup 12} ions/cm{sup 2} dose, and the cell still has good set-reset operation ability (above 10{sup 5} cycles). Furthermore, the resistance ratio remains at 1000 even after 10{sup 5} cycles of the set-reset operation. The results show the PCM cell with Ge{sub 2}Sb{sub 2}Te{sub 5} alloy has a strong ion-irradiation tolerance. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  2. The affect of bone marrow cell biomechanical characteristics to 6 Gy γ irradiation-injured mice

    International Nuclear Information System (INIS)

    Pu Xiaoyun; Chen Xiaoli; Pan Jing; Li Zhaoquan; Deng Jun; Huang Hui; Ye Yong

    2004-01-01

    Objective: To explore the change of bone marrow cell biomechanical characteristics in radiation-injured mice and the influencing factors. Methods: Male Kunming mice were exposed to total body irradiation of 6 Gy γ-rays from a 60 Co source. Electrophoresis, DPH probe-micropore filter, and adhesion rate methods were used to detect cell surface charge, membrane microviscosity, cell deformability, and cell adhesion, respectively. Results: The deformability, adhesiveness and cell surface charges of bone marrow cells (including hematopoietic cells and stromal cells) were dramatically decreased, but membrane microviscosity was obviously increased after irradiation on 1 d, 3 d and 7 d. Conclusion: The biomechanical characteristics of bone marrow cells are obviously changed after radiation injury. It might be one of the reasons of hematopoietic failure after irradiation. (authors)

  3. Total body irradiation in hematopoietic stem cell transplantation

    Directory of Open Access Journals (Sweden)

    Fundagul Andic

    2014-06-01

    Full Text Available Total body irradiation is used in conjunction with chemotherapy as a conditioning regimen in the treatment of many disease such as leukemia, myelodysplastic syndrome, aplastic anemia, multiple myeloma and lymphoma prior to the hematopoetic stem cell transplantation. The main purposes of the hematopoetic stem cell transplantation are eradication of the recipient bone marrow and any residual cancer cells, creation of space in the receipient bone marrow for donor hematopoetic stem cells, and immunosuppression to prevent rejection of donor stem cells in the case of an allotransplant. [Archives Medical Review Journal 2014; 23(3.000: 398-410

  4. The influence of hyperthermia and irradiation on some bioelectric parameters of the cells

    International Nuclear Information System (INIS)

    Solic, F.; Milotic, B.; Stipcic-Solic, N.

    1986-01-01

    The simultaneously influence of hyperthermia and low intensity gamma irradiation on the biopotential and the resistance of Nitella cells were investigated. The effect induced by irradiation and hyperthermia is manifested as membrane repolarization while hyperthermia alone induced depolarization. The resistance of cells is in positive correlation with membrane potential. (author)

  5. The regulation effect of STAT 5 signaling pathway on the cell cycle progression of irradiated KG-1 cells

    International Nuclear Information System (INIS)

    Guo Dehuang; Dong Bo; Luo Qingliang; Wen Gengyun; Mao Bingzhi

    2000-01-01

    The author investigated the role of the JAK/STAT signaling pathway regulating cell cycle progression in the irradiated KG-1 cells. By permanent transfecting the cells with DN-STAT 5 cDNA to block the JAK/STAT signaling pathway and then transient transfecting with cyclin D 1 or cyclin B 1 cDNA, the effects of cyclin D 1 protein and cyclin B 1 protein on the cell cycle progression were examined. Results showed that after irradiation with 8Gy 60 Co rays, the irradiated KG-1 cells transfected with only DN-STAT 5 cDNA can not recover form the G 1 arrest, even though GM-CSF was added. Meanwhile, the cells transfected with both the DN-STAT 5 cDNA and cyclin D 1 cDNA or cyclin B 1 cDNA can recover from the G 1 arrest or the G 2 arrest to a great extent. Thus, it was proved indirectly that the JAK/STAT signaling pathway activated by GM-CSF regulated the cell cycle progression through cyclin D 1 and cyclin B 1 protein

  6. Biological studies using mammalian cell lines and the current status of the microbeam irradiation system, SPICE

    Energy Technology Data Exchange (ETDEWEB)

    Konishi, T. [Dept. of Technical Support and Development, Fundamental Technology Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan)], E-mail: tkonishi@nirs.go.jp; Ishikawa, T. [Dept. of Technical Support and Development, Fundamental Technology Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Iso, H. [Dept. of Technical Support and Development, Fundamental Technology Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Neos-Tech Co. Ltd., Benten 4-11-13-202, Chuo-ku, Chiba 206-0045 (Japan); Yasuda, N.; Oikawa, M. [Dept. of Technical Support and Development, Fundamental Technology Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Higuchi, Y. [Dept. of Technical Support and Development, Fundamental Technology Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Neos-Tech Co. Ltd., Benten 4-11-13-202, Chuo-ku, Chiba 206-0045 (Japan); Kato, T. [Dept. of Technical Support and Development, Fundamental Technology Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Graduate School of Science, Rikkyo University, 3-34-1 Nishi-Ikebukuro, Toshimaku, Tokyo 171-8501 (Japan); Hafer, K. [Department of Radiation Oncology, UCLA School of Medicine, Los Angeles, CA (United States); Kodama, K. [Dept. of Technical Support and Development, Fundamental Technology Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Neos-Tech Co. Ltd., Benten 4-11-13-202, Chuo-ku, Chiba 206-0045 (Japan); Hamano, T.; Suya, N.; Imaseki, H. [Dept. of Technical Support and Development, Fundamental Technology Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan)

    2009-06-15

    The development of SPICE (single-particle irradiation system to cell), a microbeam irradiation system, has been completed at the National Institute of Radiological Sciences (NIRS). The beam size has been improved to approximately 5 {mu}m in diameter, and the cell targeting system can irradiate up to 400-500 cells per minute. Two cell dishes have been specially designed: one a Si{sub 3}N{sub 4} plate (2.5 mm x 2.5 mm area with 1 {mu}m thickness) supported by a 7.5 mm x 7.5 mm frame of 200 {mu}m thickness, and the other a Mylar film stretched by pressing with a metal ring. Both dish types may be placed on a voice coil stage equipped on the cell targeting system, which includes a fluorescent microscope and a CCD camera for capturing cell images. This microscope system captures images of dyed cell nuclei, computes the location coordinates of individual cells, and synchronizes this with the voice coil motor stage and single-particle irradiation system consisting of a scintillation counter and a beam deflector. Irradiation of selected cells with a programmable number of protons is now automatable. We employed the simultaneous detection method for visualizing the position of mammalian cells and proton traversal through CR-39 to determine whether the targeted cells are actually irradiated. An immuno-assay was also performed against {gamma}-H2AX, to confirm the induction of DNA double-strand breaks in the target cells.

  7. High-dose irradiation induces cell cycle arrest, apoptosis, and developmental defects during Drosophila oogenesis.

    Directory of Open Access Journals (Sweden)

    Hee Jin Shim

    Full Text Available Ionizing radiation (IR treatment induces a DNA damage response, including cell cycle arrest, DNA repair, and apoptosis in metazoan somatic cells. Because little has been reported in germline cells, we performed a temporal analysis of the DNA damage response utilizing Drosophila oogenesis as a model system. Oogenesis in the adult Drosophila female begins with the generation of 16-cell cyst by four mitotic divisions of a cystoblast derived from the germline stem cells. We found that high-dose irradiation induced S and G2 arrests in these mitotically dividing germline cells in a grp/Chk1- and mnk/Chk2-dependent manner. However, the upstream kinase mei-41, Drosophila ATR ortholog, was required for the S-phase checkpoint but not for the G2 arrest. As in somatic cells, mnk/Chk2 and dp53 were required for the major cell death observed in early oogenesis when oocyte selection and meiotic recombination occurs. Similar to the unscheduled DNA double-strand breaks (DSBs generated from defective repair during meiotic recombination, IR-induced DSBs produced developmental defects affecting the spherical morphology of meiotic chromosomes and dorsal-ventral patterning. Moreover, various morphological abnormalities in the ovary were detected after irradiation. Most of the IR-induced defects observed in oogenesis were reversible and were restored between 24 and 96 h after irradiation. These defects in oogenesis severely reduced daily egg production and the hatch rate of the embryos of irradiated female. In summary, irradiated germline cells induced DSBs, cell cycle arrest, apoptosis, and developmental defects resulting in reduction of egg production and defective embryogenesis.

  8. Attempts of local irradiation of cells by microbeam. From ultraviolet to heavy particles

    Energy Technology Data Exchange (ETDEWEB)

    Kobayashi, Yasuhiko [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    2002-03-01

    This review describes the history of attempts of local irradiation of cells by microbeam and present status of the study. Local irradiation of cells was attempted as early as in 1912 with use of short {alpha}-particle range and of focused UV beams. After the war, laser microbeams were then developed for microsurgery in embryology. In addition, microbeams of electron generated from the gun and of X-ray collimated were developed. In 1950s, the electron microbeam was generated from Van de Graaff accelerator in Chicago University and proton, deuteron and He-ion microbeams from the cyclotron, in BNL. In 1980s, Gesellschaft fuer Schwerionenforshung (Germany) used heavy ion microbeams from C to U generated from the linear accelerator and PNL, proton to {sup 4}He-ion microbeams from the tandem-electrostatic accelerator. At present in 2002, the equipments for microbeam for cell irradiation are the Van de Graaff accelerators in Gray Cancer Institute (England) and in Columbia University, and the cyclotron in TIARA in Japan. The purpose of the study in TIARA is to develop a system to generate heavy particle microbeams for cell irradiation for analysis of the biological effect of ultra-low fluence, high LET heavy particles like the galactic cosmic ray. Recently, the CHO-KI cell nucleus is irradiated by {sup 40}Ar and {sup 20}Ne ions. (K.H.)

  9. Attempts of local irradiation of cells by microbeam. From ultraviolet to heavy particles

    International Nuclear Information System (INIS)

    Kobayashi, Yasuhiko

    2002-01-01

    This review describes the history of attempts of local irradiation of cells by microbeam and present status of the study. Local irradiation of cells was attempted as early as in 1912 with use of short α-particle range and of focused UV beams. After the war, laser microbeams were then developed for microsurgery in embryology. In addition, microbeams of electron generated from the gun and of X-ray collimated were developed. In 1950s, the electron microbeam was generated from Van de Graaff accelerator in Chicago University and proton, deuteron and He-ion microbeams from the cyclotron, in BNL. In 1980s, Gesellschaft fuer Schwerionenforshung (Germany) used heavy ion microbeams from C to U generated from the linear accelerator and PNL, proton to 4 He-ion microbeams from the tandem-electrostatic accelerator. At present in 2002, the equipments for microbeam for cell irradiation are the Van de Graaff accelerators in Gray Cancer Institute (England) and in Columbia University, and the cyclotron in TIARA in Japan. The purpose of the study in TIARA is to develop a system to generate heavy particle microbeams for cell irradiation for analysis of the biological effect of ultra-low fluence, high LET heavy particles like the galactic cosmic ray. Recently, the CHO-KI cell nucleus is irradiated by 40 Ar and 20 Ne ions. (K.H.)

  10. Effects of hyperthermia, x-ray irradiation and their combination on ascites tumor cells of mice

    International Nuclear Information System (INIS)

    Kaneko, Itsuo

    1982-01-01

    Fibrosarcoma ascites tumor cells (PB8) from NMRI mice were used to investigate cell loss by hyperthermia and/or x-ray irradiation. The tumor cells were labelled by an injection of 125 I-deoxyuridine to the abdominal cavity of the donors 2 days before the physical treatments. The labelled cells, transfered in test tubes, were heated at 44 0 C for 10-20 min and/or irradiated by x-ray at 250-1612 rad, and were transplanted in the recipient abdominal cavity as soon as possible after the treatments. The radioactivity of the tumor cells, as an indicator of cell loss, was measured with a gamma spectrometer. In the irradiated group, the ratio of cell loss increased in a dose-dependent manner, starting from the 4th day after the transplantation to the 9th day. In the heated group, the ratio of cell loss increased in proportion to the heating time, starting without delay after transplantation. In the combination group, the effect of the treatments was more marked than that by each single treatment. In the early stage of this group, cell loss was by heating and then, from the 4th day, the irradiation effect mostly dominated. It is concluded from the above results that cell loss by heating or irradiation is independent and that the effect of the combination is additive. (author)

  11. 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%

  12. Relationship of colony-stimulating activity to apparent kill of human colony-forming cells by irradiation and hydroxyurea

    International Nuclear Information System (INIS)

    Broxmeyer, H.E.; Galbraith, P.R.; Baker, F.L.

    1976-01-01

    Suspensions of human bone marrow cells were subjected to 137 Cs irradiation in vitro and then cultured in semisolid agar medium. Cultures of irradiated cells were stimulated with colony-stimulating activity (CSA) of different potencies, and it was found that the amount of stimulation applied to cultures influenced the apparent kill of colony-forming cells (CFC). It was also found that the effects of irradiation on colony formation were not confined to CFC kill since medium conditioned by cells during irradiation exhibited stimulatory and inhibitory properties after treatment by 600 and 1000 rads, respectively. Studies in which irradiated cells were pretreated with hydroxyurea indicated that CFC in the DNA synthetic phase of the cell cycle were particularly sensitive to low doses of irradiation. The proliferative capacity of CFC surviving 1000 rads was undiminished as judged by their ability to form large colonies. Estimates of CFC kill by hydroxyurea were also affected by the level of CSA

  13. Response of mesenchymal stem cells in mice to 3.5 Gy X-ray irradiation

    International Nuclear Information System (INIS)

    Su Wenxia; Liu Huimin; Chen Yonghong; Zeng Wen; Liu Wenli; Sun Hanying

    2011-01-01

    Objective: To investigate the response of mesenchymal stem cells in mice to medium-dose X-ray irradiation in vitro. Methods: The mouse mesenchymal stem cell line C3H10T1/2 was submitted to 3.5 Gy X-ray irradiation. Hoechst33258 staining of adherent cells and Annexin V-FITC staining and flow cytometry analysis of suspension cells were performed respectively to assess cellular apoptosis at 3, 6, 12, 24, 48, 72 h and 1 week after irradiation. SA-β-gal staining was performed to analyze the cellular senescence at 24, 48, 72 h and 1 week after irradiation. The mRNA level of both Fas with its ligand FasL and p53 with its downstream target p21 WAF1 were measured by Real-Time PCR analysis. The expression of Fas protein was determined by immunofluorescence staining. Results: An increased apoptosis was observed at 3 h after irradiation with apoptosis rate 11.72% ± 1.61% (t=9.01, P<0.01), the apoptosis rate reached the peak level at 12 h 20.52% ± 1.96% (t=16.27, P<0.01), and then declined progressively to normal level at 48 h 4.93% ±0.46% (t=2.26, P>0.05). The SA-β-gal positive rate of post-radiation cells at 72 h was 53.33% ± 5.62%, significantly higher than that of normal control 3.24% ± 0.39% (t=17.77, P<0.01). The level of Fas, FasL mRNA was found to be elevated 3 h after irradiation with a peak at 12 h, and no differences were found l week later. The level of Fas protein was observed to reach the peak at 12 h after irradiation. The occurrence of peak level of Fas/FasL mRNA and protein was consistent with that of apoptosis of C3H10T1/2 cell. A transient up-regulation of p53, p21 WAF1 mRNA expression was found at 12 h after irradiation followed by a significant increase later at 72 h after irradiation. The occurrence of the two peaks of p53, p21 WAF1 mRNA expression were coincident with that of cellular apoptosis and senescence, respectively. The levels of p53, p21 WAF1 mRNA in senescence group were significantly higher than those of apoptosis group (t=17.85, 13

  14. Sensitivity of Vibrio cholerae cells to lethal and mutagenic effect of UV-irradiation mediated by plasmids

    International Nuclear Information System (INIS)

    Tiganova, I.G.; Evdokimova, N.M.; Aleshkin, G.I.

    1988-01-01

    The effect of UV-irradiation on Vibrio cholerae cells and its changes mediated by the plasmid R245 have been studied. Vibrio cholerae strains 569B and RV31 have been shown to be considerably more sensitive to lethal effect of UV-irradiation as compared with Escherichia coli and Salmonella typhimurium cells. Highly toxigenic strain 569B and practically atoxigenic strain RV31 have the same UV-sensitivity. Lethla effect of UV-irradiation on Vibrio cholerae cells is incresed when the irradiated cells are plated on enriched media. UV-induction of mutations was not registered in plasmidless strains of Vibrio cholerae. Plasmid R245 increase UV-resistance of vibrio cells and makes them UV-mutable

  15. The biological effect of 125I seed continuous low dose rate irradiation in CL187 cells

    Directory of Open Access Journals (Sweden)

    Zhuang Hong-Qing

    2009-01-01

    Full Text Available Abstract Background To investigate the effectiveness and mechanism of 125I seed continuous low-dose-rate irradiation on colonic cell line CL187 in vitro. Methods The CL187 cell line was exposed to radiation of 60Coγ ray at high dose rate of 2 Gy/min and 125I seed at low dose rate of 2.77 cGy/h. Radiation responses to different doses and dose rates were evaluated by colony-forming assay. Under 125I seed low dose rate irradiation, a total of 12 culture dishes were randomly divided into 4 groups: Control group, and 2, 5, and 10 Gy irradiation groups. At 48 h after irradiation, apoptosis was detected by Annexin and Propidium iodide (PI staining. Cell cycle arrests were detected by PI staining. In order to investigate the influence of low dose rate irradiation on the MAPK signal transduction, the expression changes of epidermal growth factor receptor (EGFR and Raf under continuous low dose rate irradiation (CLDR and/or EGFR monoclonal antibodies were determined by indirect immunofluorescence. Results The relative biological effect (RBE for 125I seeds compared with 60Co γ ray was 1.41. Apoptosis rates of CL187 cancer cells were 13.74% ± 1.63%, 32.58% ± 3.61%, and 46.27% ± 3.82% after 2 Gy, 5 Gy, and 10 Gy irradiation, respectively; however, the control group apoptosis rate was 1.67% ± 0.19%. G2/M cell cycle arrests of CL187 cancer cells were 42.59% ± 3.21%, 59.84% ± 4.96%, and 34.61% ± 2.79% after 2 Gy, 5 Gy, and 10 Gy irradiation, respectively; however, the control group apoptosis rate was 26.44% ± 2.53%. P 2/M cell cycle arrest. After low dose rate irradiation, EGFR and Raf expression increased, but when EGFR was blocked by a monoclonal antibody, EGFR and Raf expression did not change. Conclusion 125I seeds resulted in more effective inhibition than 60Co γ ray high dose rate irradiation in CL187 cells. Apoptosis following G2/M cell cycle arrest was the main mechanism of cell-killing effects under low dose rate irradiation. CLDR could

  16. 1H MRS can detect dose dependent effects in irradiated tumor cells and spheroids

    International Nuclear Information System (INIS)

    Grande, S.; Viti, V.; Guidoni, L.; Luciani, A.M.

    2003-01-01

    Full text: 1 H MR spectra of tumour cells are often characterised by the presence of intense signals from the methylene fatty acid chains of mobile lipids (ML), mostly triglycerides (TG). In previous work (Magnetic Resonance in Medicine ,1999, 42:248-257), we showed that the intensity of these signals is modulated by cell proliferation. Polyunsaturation levels of the fatty acid chains were also found higher when mobile lipid signals were intense, in agreement with independent findings by other authors (Nat. Med . 1999, 5:1323-1327). Cells from breast carcinoma (MCF 7) were irradiated at increasing doses (5 - 40 Gy) to detect spectral differences in irradiated cells and to relate them to the metabolic breakdown accompanying cell death. Early and late, metabolism mediated , effects were observed. The main effect observed shortly after treatment was a decrease in ML peak intensity, probably from the oxidative damage to the involved lipid structures. On the other hand, when cells were observed after 24, 48 and 72 hours, irradiated cells displayed more intense ML peaks, with a maximum effect after 48 hours, irrespective of the initial intensity of ML signals. The effect was found dose dependent. Also peaks from lipid polyunsaturation were found higher in irradiated samples. Moreover, also phosphorylcholine and glutathione signals were affected by irradiation. Similar effects were found in multicellular spheroids from the same cell strain. Association of the observed changes with apoptotic death is currently under consideration

  17. The re-establishment of hypersensitive cells in the crypts of irradiated mouse intestine

    International Nuclear Information System (INIS)

    Ijiri, K.; Potten, C.S.

    1984-01-01

    Two doses of γ-radiation separated by various time intervals have been used to investigate when after irradiation the cell population susceptible to acute cell death is re-established. Dead cells were scored 3 or 6 h after the second dose. Within 1-2 days of small doses (0.5 Gy) the sensitive cells, recognized histologically as apoptotic cells, are re-established at the base of the crypt (around cell position 6). After higher doses (9.0 Gy) they are not re-established until about the fourth day after irradiation. Even in the enlarged regenerating crypts the sensitive cells are found at the same position at the crypt base. It has been estimated that the crypt contains five or six cells that are susceptible to low doses (0.5 Gy) (hypersensitive cells) and up to a total of only seven or eight susceptible cells that can be induced by any dose to enter the sequence of changes implicit in apoptosis. Between 4 and 10 days after an intitial irradiation of 9.0 Gy the total number of susceptible cells increased from seven to eight to about 10 to 13 per crypt. (author)

  18. Evidence of heritable lethal mutations in progeny of X-irradiated CHO cells by micronucleus count in clon-cells

    International Nuclear Information System (INIS)

    Hagemann, G.; Kreczik, A.; Treichel, M.

    1996-01-01

    Low doses of ionizing radiation reduce the growth rates of clones following irradiation of the progenitor cells. Such reductions of clone growth have been proven by means of measurements of clone size distributions. The medians of such distributions can be used to quantify the radiation damage. Prolongations of generation times and cell death as result of heritable lethal mutations have been discussed as causes for the reduction of clone growth. The cell number of a clone of hypotetraploid CHO-cells was compared to the frequency of micronucleated binucleated cells in the same clone using the cytokinesis-block-micronucleus method. The dose dependent reduction of clone sizes is measured by the difference of the medians (after log transformation) of the clone size distributions. At cytochalasin-B concentrations of 1 μg/ml and after an incubation time of 16 h a yield of binucleated cells of about 50% was obtained. Median clone size differences as a measure of clonal radiation damage increased linearly with incubation times of 76, 100, 124, and 240 h following irradiation with 3, 5, 7, and 12 Gy. The frequency of binucleated clone cells with micronuclei strongly increased with decreasing clone size by a factor up to 20 following irradiation with 3, 5, and 7 Gy. The frequency of micronucleated binucleated clone cells was found to be independent of incubation time after irradiation. Radiation induced clone size reductions result from cell losses caused by intraclonal expression of micronuclei which have its origin in heritable lethal mutations. Measurements of clone size distributions can be done automatically. They can serve as predictive test for determination of median cell loss rates of surviving cell clones. (orig./MG) [de

  19. [Effect of electromagnetic pulse irradiation on structure and function of Leydig cells in mice].

    Science.gov (United States)

    Wang, Shui-Ming; Wang, De-Wen; Peng, Rui-Yun; Gao, Ya-Bing; Yang, Yi; Hu, Wen-Hua; Chen, Hao-Yu; Zhang, You-Ren; Gao, Yan

    2003-08-01

    To explore the effect of electromagnetic pulse (EMP) irradiation on structure and function of Leydig cells in mice. One hundred and fourteen male Kunming mice were randomly divided into irradiated and control group, the former radiated generally by 8 x 10(3) V/m, 2 x 10(4) V/m and 6 x 10(4) V/m EMP respectively five times within two minutes. Pathological changes of Leydig cells were observed by light and electron microscope. Serum testosterone (T), luteinizing hormone (LH) and estradiol (E2) were measured dynamically by radioimmunoassay at 6 h, 1 d, 3 d, 7 d, 14 d and 28 d after irradiation. Main pathological changes were edema and vacuolation, swelling of cytoplasmic mitochondria, reduce of lipid droplets, pale staining of most of lipid droplets, and partial or complete cavitation of lipid droplets in Leydig cells within 28 days after EMP radiation. Compared with normal controls, serum T decreased in all in different degrees within 28 days, and dropped significantly at 6 h-14 d, 6 h-7 d and 1 d-28 d after 8 x 10(3) V/m, 2 x 10(4) V/m and 6 x 10(4) V/m EMP irradiation(P < 0.05 or P < 0.01). EMP irradiation caused no significant changes in serum LH and E2. Leydig cells are among those that are the most susceptible to EMP irradiation. EMP irradiation may cause significant injury in structure and function of Leydig cells in mice, whose earlier and continuous effect is bound to affect sexual function and sperm production.

  20. Whole tumor antigen vaccination using dendritic cells: Comparison of RNA electroporation and pulsing with UV-irradiated tumor cells

    Directory of Open Access Journals (Sweden)

    Benencia Fabian

    2008-04-01

    Full Text Available Abstract Because of the lack of full characterization of tumor associated antigens for solid tumors, whole antigen use is a convenient approach to tumor vaccination. Tumor RNA and apoptotic tumor cells have been used as a source of whole tumor antigen to prepare dendritic cell (DC based tumor vaccines, but their efficacy has not been directly compared. Here we compare directly RNA electroporation and pulsing of DCs with whole tumor cells killed by ultraviolet (UV B radiation using a convenient tumor model expressing human papilloma virus (HPV E6 and E7 oncogenes. Although both approaches led to DCs presenting tumor antigen, electroporation with tumor cell total RNA induced a significantly higher frequency of tumor-reactive IFN-gamma secreting T cells, and E7-specific CD8+ lymphocytes compared to pulsing with UV-irradiated tumor cells. DCs electroporated with tumor cell RNA induced a larger tumor infiltration by T cells and produced a significantly stronger delay in tumor growth compared to DCs pulsed with UV-irradiated tumor cells. We conclude that electroporation with whole tumor cell RNA and pulsing with UV-irradiated tumor cells are both effective in eliciting antitumor immune response, but RNA electroporation results in more potent tumor vaccination under the examined experimental conditions.

  1. Thymic nurse cells and thymic repopulation after whole body sublethal irradiation in mice

    International Nuclear Information System (INIS)

    Houben-Defresne, M.P.; Varlet, A.; Boniver, J.

    1984-01-01

    Thymic Nurse Cells (TNCs) are lymphoepithelial complexes which are thought to play a role in the early stages of the intrathymic differentiation pathway. Their repopulation kinetics were analyzed in mice after sublethal whole-body irradiation. Changes of the number of TNCs per thymus were parallel with the evolution of the whole thymocyte population. Particularly, a first wave of TNCs restoration was followed by a secondary depletion and a final recovery. This suggests that TNCs restoration is related to the proliferating progeny of intrathymic radioresistant thymocytes. When normal bone marrow cells were grafted intravenously after irradiation, no secondary depletion was found. This pattern of restoration was obviously related to thymic repopulation by cells which were derived from the inoculated bone marrow. Homing studies with FITC labelled bone marrow cells showed that inoculated bone marrow cells did not penetrate TNCs early after irradiation. Later on, when immigrant cells started to proliferate, they were found preferentially within TNCs before spreading in the whole thymus. (Auth.)

  2. Clonal proliferation and karyotypic features of cells in bone marrow after irradiation

    International Nuclear Information System (INIS)

    Kohno, S.; Ishihara, T.

    1979-01-01

    Single stem cells in which chromosome abnormalities are induced by radiation may multiply to form the chromosomally abnormal clones of cells that may replace most of the cells in regenerating hematopoietic tissues after irradiation. It is only a limited number of karyotypes out of a variety of the cells with radiation-induced chromosome abnormalities that can persist as proliferative clones. Such clones in the bone marrows of irradiated rats were found to have aneusomic chromosome constitutions with trisomy or monosomy. This finding is contradictory to the general beliefs that the chromosomally abnormal clones surviving after irradiation would have the chromosome constitutions comparable to a normal diploid set making such clone cells selectively neutral, and that autosomally monosomic cells would not be able to compete against the cells in normal somatic tissues. The proliferation of aneusomic cells in hematopoietic tissues is a phenomenon observable in various blood disorders such as leukemia. The fact that almost all of the aneuploid clones observed possessed various chromosomal rearrangements in addition to their numerical changes appears to indicate that the chromosomal imbalance in original clones may predispose their chromosomes to non-disjunction. The process of the leukemic development of cells may require two steps: the leukemic transformation of cells and the proliferation of such transformed cells up to the manifestation of the disease. (Yamashita, S.)

  3. Cell and tissue kinetics of the subependymal layer in mouse brain following heavy charged particle irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Manley, N.B.; Fabrikant, J.I.; Alpen, E.L.

    1988-12-01

    The following studies investigate the cellular response and cell population kinetics of the subependymal layer in the mouse brain exposed to heavy charged particle irradiation. Partial brain irradiation with helium and neon ions was confined to one cortex of the brain. Both the irradiated and the unirradiated contralateral cortex showed similar disturbances of the cell and tissue kinetics in the subependymal layers. The irradiated hemisphere exhibited histological damage, whereas the unirradiated side appeared normal histologically. This study concerns the cell population and cell cycle kinetics of the subependymal layer in the mouse brain, and the effects of charged particle irradiations on this cell population. Quantitative high resolution autoradiography was used to study the kinetic parameters in this cell layer. This study should help in understanding the effects of these high-energy heavy ions on normal mammalian brain tissue. The response of the mammalian brain exposure to charged particle ionizing radiation may be extremely variable. It varies from minimal physiological changes to overt tissue necrosis depending on a number of factors such as: the administered dose, dose-rate, the volume of the irradiated tissue, and the biological end-point being examined.

  4. EDF requirements for hot cells examinations on irradiated fuel

    International Nuclear Information System (INIS)

    Segura, J.C.; Ducros, G.

    2002-01-01

    The objectives of increasing French Nuclear Power Plants (NPP) availability while lengthening the fuel irradiation cycle and reaching higher burnups lead EDF to carry out on site and hot cell examinations. The data issued from such fuel behaviour monitoring programmes will be used to ascertain that the design criteria are met. Data are also needed for modelling, development and validation. The paper deals quickly with the logistics linked to the selection and transport of fuel rods from NPP to hot cell laboratory. Hot cell PIEs remain a valuable method to obtain data in such fields as PCI (Pellet-Cladding Interaction), internal pressure, FGR (Fission Gas Release), oxide thickness, metallurgical aspects. The paper introduces burnup determination methods, inner pressure evaluation, preparation of samples for further irradiation such as power ramps for PCI and RIA (Reactivity Initiated Accident) testing. The nuclear microprobe of Perre Suee laboratory is also presented. (author)

  5. Distinct radioprotective activities of major heat shock proteins in irradiated mammalian cells

    International Nuclear Information System (INIS)

    Kabakov, Alexander; Malyutina, Yana; Kudryavtsev, Vladimir

    2008-01-01

    Full text: Several years ago we have suggested that heat shock proteins (Hsps) can be involved in cellular and tissue mechanisms of protection from ionizing radiation. At present, the accumulated experimental data do allow us to characterize three major mammalian Hsps, Hsp70, Hsp27 and Hsp90, as specific endogenous radioprotectors which are able to prevent or minimize cell death resulting from the radiation exposure. It follows from the many findings that the radioprotective effect of these Hsps is particularly manifested in their ability to attenuate apoptosis in various normal and tumor cells irradiated in vivo or in vitro. The obtained data already enable to suggest three main mechanisms of the radioprotection conferred by the excess Hsps: 1) Modulation of the intracellular signaling so that the apoptotic signal transduction is blocked, whereas the 'cell survival' signal transduction is stimulated; 2) Suppression of the radiation-associated free radical generation and apoptosis induced by reactive oxygen species (ROS); 3) Attenuation of the genotoxic impact of ionizing radiation. The latter suggested mechanism seems particularly intriguing and implies that the excess Hsps can somehow contribute to protection/repair of genomic DNA from radiation-induced damage. According to our recent results, Hsp90 is indeed involved in the post-irradiation repair of nuclear DNA, while excess Hsp70 can beneficially affect the p53-mediated DNA damage response in irradiated cells to ensure their long-term survival and recovery. As for Hsp27, we found that its accumulation in target cells increases their radioresistance by enhancing the irradiation-responsive activation of anti apoptotic pathways. While the Hsp70 and Hsp27 seem to perform different functions in irradiated cells, the synergistic enhancement of radioprotection was clearly observed in the cells enriched by the both the Hsps. In vivo, such radioprotective activities of the major mammalian Hsps may play a role in

  6. Chromosomal Aberrations in Normal and AT Cells Exposed to High Dose of Low Dose Rate Irradiation

    Science.gov (United States)

    Kawata, T.; Shigematsu, N.; Kawaguchi, O.; Liu, C.; Furusawa, Y.; Hirayama, R.; George, K.; Cucinotta, F.

    2011-01-01

    Ataxia telangiectasia (A-T) is a human autosomally recessive syndrome characterized by cerebellar ataxia, telangiectases, immune dysfunction, and genomic instability, and high rate of cancer incidence. A-T cell lines are abnormally sensitive to agents that induce DNA double strand breaks, including ionizing radiation. The diverse clinical features in individuals affected by A-T and the complex cellular phenotypes are all linked to the functional inactivation of a single gene (AT mutated). It is well known that cells deficient in ATM show increased yields of both simple and complex chromosomal aberrations after high-dose-rate irradiation, but, less is known on how cells respond to low-dose-rate irradiation. It has been shown that AT cells contain a large number of unrejoined breaks after both low-dose-rate irradiation and high-dose-rate irradiation, however sensitivity for chromosomal aberrations at low-dose-rate are less often studied. To study how AT cells respond to low-dose-rate irradiation, we exposed confluent normal and AT fibroblast cells to up to 3 Gy of gamma-irradiation at a dose rate of 0.5 Gy/day and analyzed chromosomal aberrations in G0 using fusion PCC (Premature Chromosomal Condensation) technique. Giemsa staining showed that 1 Gy induces around 0.36 unrejoined fragments per cell in normal cells and around 1.35 fragments in AT cells, whereas 3Gy induces around 0.65 fragments in normal cells and around 3.3 fragments in AT cells. This result indicates that AT cells can rejoin breaks less effectively in G0 phase of the cell cycle? compared to normal cells. We also analyzed chromosomal exchanges in normal and AT cells after exposure to 3 Gy of low-dose-rate rays using a combination of G0 PCC and FISH techniques. Misrejoining was detected in the AT cells only? When cells irradiated with 3 Gy were subcultured and G2 chromosomal aberrations were analyzed using calyculin-A induced PCC technique, the yield of unrejoined breaks decreased in both normal and AT

  7. Optical and electrical properties of electron-irradiated Cu(In,Ga)Se{sub 2} solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Hirose, Y.; Warasawa, M. [Department of Electrical Engineering, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda 278-8510 (Japan); Takakura, K. [Department of Information, Communication and Electrical Engineering, Kumamoto National College of Technology, 2659-2 Suya, Koshi, Kumamoto 861-1102 (Japan); Kimura, S. [Department of Electrical Engineering, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda 278-8510 (Japan); Chichibu, S.F. [CANTech, Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1 Katahira, Aoba, Sendai 980-8577 (Japan); Ohyama, H. [Department of Information, Communication and Electrical Engineering, Kumamoto National College of Technology, 2659-2 Suya, Koshi, Kumamoto 861-1102 (Japan); Sugiyama, M., E-mail: mutsumi@rs.noda.tus.ac.jp [Department of Electrical Engineering, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda 278-8510 (Japan)

    2011-08-31

    The optical and electrical properties of electron-irradiated Cu(In,Ga)Se{sub 2} (CIGS) solar cells and the thin films that composed the CIGS solar cell structure were investigated. The transmittance of indium tin oxide (ITO), ZnO:Al, ZnO:Ga, undoped ZnO, and CdS thin films did not change for a fluence of up to 1.5 x 10{sup 18} cm{sup -2}. However, the resistivity of ZnO:Al and ZnO:Ga, which are generally used as window layers for CIGS solar cells, increased with increasing irradiation fluence. For CIGS thin films, the photoluminescence peak intensity due to Cu-related point defects, which do not significantly affect solar cell performance, increased with increasing electron irradiation. In CIGS solar cells, decreasing J{sub SC} and increasing R{sub s} reflected the influence of irradiated ZnO:Al, and decreasing V{sub OC} and increasing R{sub sh} mainly tended to reflect the pn-interface properties. These results may indicate that the surface ZnO:Al thin film and several heterojunctions tend to degrade easily by electron irradiation as compared with the bulk of semiconductor-composed solar cells.

  8. Radiobiologic significance of apoptosis and micronucleation in quiescent cells within solid tumors following γ-ray irradiation

    International Nuclear Information System (INIS)

    Masunaga, Shin-ichiro; Ono, Koji; Suzuki, Minoru; Kinashi, Yuko; Takagaki, Masao

    2001-01-01

    Purpose: To determine the frequency of apoptosis in quiescent (Q) cells within solid tumors following γ-ray irradiation, using four different tumor cell lines. In addition, to assess the significance of detecting apoptosis in these cell lines. Methods and Materials: C3H/He mice bearing SCC VII or FM3A tumors, Balb/c mice bearing EMT6/KU tumors, and C57BL mice bearing EL4 tumors received 5-bromo-2'-deoxyuridine (BrdU) continuously for 5 days via implanted mini-osmotic pumps to label all proliferating (P) cells. The mice then received γ-ray irradiation at a dose of 4-25 Gy while alive or after tumor clamping. Immediately after irradiation, the tumors were excised, minced, and trypsinized. The tumor cell suspensions thus obtained were incubated with cytochalasin-B (a cytokinesis blocker), and the micronucleus (MN) frequency in cells without BrdU labeling (=Q cells) was determined using immunofluorescence staining for BrdU. Meanwhile, 6 hours after irradiation, tumor cell suspensions obtained in the same manner were fixed. The apoptosis frequency in Q cells was also determined with immunofluorescence staining for BrdU. The MN and apoptosis frequency in total (P+Q) tumor cells were determined from the tumors that were not pretreated with BrdU. Results: In total cells, SCC VII, FM3A, and EMT6/KU cells showed reasonable relationships between MN frequency and surviving fraction (SF). However, fewer micronuclei were induced in EL4 cells than the other cell lines. In contrast, a comparatively close relationship between apoptosis frequency and SF was found in total cells of EL4 cell line. Less apoptosis was observed in the other cell lines. Quiescent tumor cells exhibited significantly lower values of MN and apoptosis frequency probably due to their large hypoxic fraction, similar to total tumor cells on clamped irradiation. Conclusion: γ-ray irradiation induced MN formation in SCC VII, FM3A, and EMT6/KU tumor cells, and the apoptosis was marked in EL4 cells compared with

  9. Phase-changes in cell cycle of wound tissue irradiated with 5.21 Gy soft X-rays

    International Nuclear Information System (INIS)

    Liu Jianzhong; Zhou Yuanguo; Cheng Tianmin; Zhou Ping; Liu Xia; Li Ping

    2002-01-01

    Objective: To study the phase-changes in cell cycle of wound tissue which was locally irradiated with 5.21 Gy soft X-rays. Methods: Flow cytometry and PI staining were used to analyze cell cycle. Cell proliferation was determined with BrdU labeling. Results: During 3-9 days after irradiation, the percentage of the G 0 /G 1 phase cells in wound of the control side decreased while the percentage of S phase cells increased and reached the highest value on day 9. The percentage of G 2 /M phase cells also increased, and reached its peak on day 15. The percentage of G 0 /G 1 phase cell increased in wound of the irradiation side and was higher than that of the control wound, meanwhile the percentages of S and G 2 /M cells were significantly lower than those of the control wound. In the period of 12-22 days after wounding, the percentage of S phase cells increased and reached its peak value on the 22 th day. When most of cells were in S phase and arrested dramatically. Through the whole healing process, the percentage of G 2 /M in wound of the irradiation side was lower than that of the non-irradiated wound. The BrdU-positive cells were fibroblasts, endothelial cells and smooth muscle cells. Conclusion: These results suggest that G 1 block, S phase arrest, and switch of G 2 /M with suppression of mitotic activity of these cells are induced by local 5.21 Gy soft X-ray irradiation. Therefore, wound healing delay is induced partly by cell cycle arrest

  10. Enhanced thermal stability of a polymer solar cell blend induced by electron beam irradiation in the transmission electron microscope.

    Science.gov (United States)

    Bäcke, Olof; Lindqvist, Camilla; de Zerio Mendaza, Amaia Diaz; Gustafsson, Stefan; Wang, Ergang; Andersson, Mats R; Müller, Christian; Kristiansen, Per Magnus; Olsson, Eva

    2017-05-01

    We show by in situ microscopy that the effects of electron beam irradiation during transmission electron microscopy can be used to lock microstructural features and enhance the structural thermal stability of a nanostructured polymer:fullerene blend. Polymer:fullerene bulk-heterojunction thin films show great promise for use as active layers in organic solar cells but their low thermal stability is a hindrance. Lack of thermal stability complicates manufacturing and influences the lifetime of devices. To investigate how electron irradiation affects the thermal stability of polymer:fullerene films, a model bulk-heterojunction film based on a thiophene-quinoxaline copolymer and a fullerene derivative was heat-treated in-situ in a transmission electron microscope. In areas of the film that exposed to the electron beam the nanostructure of the film remained stable, while the nanostructure in areas not exposed to the electron beam underwent large phase separation and nucleation of fullerene crystals. UV-vis spectroscopy shows that the polymer:fullerene films are stable for electron doses up to 2000kGy. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Murine scid cells complement ataxia-telangiectasia cells and show a normal port-irradiation response of DNA synthesis

    International Nuclear Information System (INIS)

    Komatsu, K.; Yoshida, M.; Okumura, Y.

    1993-01-01

    The murine severe combined immunodeficient mutation (scid) is characterized by a lack of both B and T cells, due to a deficit in lymphoid variable-(diversity)-joining (V(D)J) rearrangement. Scid cells are highly sensitive to both radiation-induced killing and chromosomal aberrations. Significantly reduced D 0 and n values were demonstrated in scid cells and were similar to ataxia-telangiectasia (AT) cells (a unique human disease conferring whole body radiosensitivity). However, the kinetics of DNA synthesis after irradiation were different between the two cell types. In contrast with the radioresistant DNA synthesis of AT cells, DNA synthesis of scid cells was markedly inhibited after irradiation. The existence of different mutations was also supported by evidence of complementation in somatic cell hybrids between scid cells and AT cells. Results indicate that the radiobiological character of scid is similar to AT but is presumably caused by different mechanisms. (author)

  12. A theoretical study on the influence of the homogeneity of heavy-ion irradiation field on the survival fraction of cells

    International Nuclear Information System (INIS)

    Wen Xiaoqiong; Li Qiang; Zhou Guangming; Li Wenjian; Wang Jufang; Wei Zengquan

    2001-01-01

    In order to provide theoretical basis for the homogeneity request of heavy-ion irradiation field, the most important design parameter of the heavy-ion radiotherapy facility planned in IMP (Institute of Modern Physics), the influence of the homogeneity of heavy-ion irradiation field on the survival fraction of cells was investigated theoretically. A formula for survival fraction of cells irradiated by the un-uniform heavy-ion irradiation field was deduced to estimate the influence of the homogeneity of heavy-ion irradiation field on the survival fraction of cells. The results show that the survival fraction of cells irradiation by the un-uniform irradiation field is larger than that of cells irradiated by the uniform irradiation field, and the survival fraction of cells increases as the homogeneity of heavy-ion irradiation field decreasing. Practically, the heavy-ion irradiation field can be treated as uniform irradiation field when its homogeneity is better than 95%. According to these results, design request for the homogeneity of heavy-ion irradiation field should be better than 95%. The present results also show that the agreement of homogeneity of heavy-ion irradiation field must be checked while comparing the survival fraction curves obtained by different laboratory

  13. Ultraviolet B irradiation of human leukaemia HL-60 cells in vitro induces apoptosis

    International Nuclear Information System (INIS)

    Martin, S.J.; Cotter, T.G.

    1991-01-01

    UV radiation is known to be a potent agent for the induction of programmed cell death (apoptosis) in human skin. However, the mechanistic aspects of UV-induced apoptosis remain ill-defined. In this study the effects of varying periods of UV-irradiation on the human leukaemia HL-60 cell line and on five other human cell lines were investigated.HL-60 cells were found to rapidly undergo apoptosis en masse after short periods of UV-irradiation whereas prolonged exposure of these cells to this form of radiation induced a more rapid form of cell death which was suggestive of necrosis, the pathological mode of cell death. UV-induced apoptosis in cell lines was characterized by morphological changes as well as DNA fragmentation into unit multiples of ∼ 200 bp, which was indicative of endogenous endonuclease activation. This DNA fragmentation pattern was not detected in cells immediately after UV-irradiation, and was therefore not the result of direct UV-induced DNA damage. UV-induced apoptosis of the HL-60 cell line was found to require extracellular calcium and to be inhibited in a dose-dependent way by zinc added to the culture medium. (author)

  14. Design computations and safety report of a cell for in pile irradiation tests

    International Nuclear Information System (INIS)

    Verri, A.

    1987-01-01

    The criteria adopted in positioning the irradiation cell within the 1Mw TRIGA reactor of the ENEA Casaccia are reported. Maximum heat which can be released by the cell is then evaluated. The final configuration of the cell as a whole, the heating system for the sample under irradiation, the procedure used in the calculations, are also reported. The selection and the design of the safety system, including auxiliary equipments are discussed

  15. The radiosensitizing effect of doranidazole on human colorectal cancer cells exposed to high doses of irradiation

    International Nuclear Information System (INIS)

    Zhang, Li; Gong, Aimin; Ji, Jun; Wu, Yuanyuan; Zhu, Xiaoyu; Lv, Suqing; Lv, Hongzhu; Sun, Xizhuo

    2007-01-01

    This paper investigates the effects of a new radiosensitizer, doranidazole, and enhancing irradiation on colorectal cancer cells. The radiosensitizing effect of doranidazole was determined using colony formation and propidium iodide (PI) assays to measure cell growth inhibition and the cell killing effect of human colorectal cancer cell lines exposed to high doses of γ-ray irradiation under hypoxic conditions in vitro. Fluorescence staining and cell migration assays were also used to assess the radiosensitizing effect. Cell proliferation evaluated by clonogenic survival curves was significantly inhibited by 5 mmol/L doranidazole, particularly at doses ranging from 10 to 30 Gy of irradiation. The radiosensitizing effect of doranidazole on colorectal cancer cells occurs in a time- and dose-dependent manner. Doranidazole also inhibited the mobility of cell invasion and migration. Doranidazole can enhance the killing effect and the cell growth inhibition of colorectal cancer after high-dose irradiation in a time and dose-dependent manner

  16. Repopulation capacity during fractionated irradiation of squamous cell carcinomas and glioblastomas in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Budach, Wilfried; Gioioso, Danielle; Taghian, Alphonse; Stuschke, Martin; Suit, Herman D

    1997-10-01

    Purpose: Determination of clonogenic cell proliferation of three highly malignant squamous cell carcinomas (SCC) and two glioblastoma cell lines during a 20-day course of fractionated irradiation under in vitro conditions. Methods and Materials: Tumor cells in exponential growth phase were plated in 24-well plastic flasks and irradiated 24 h after plating with 250 kV x-rays at room temperature. Six fractions with single doses between 0.6 and 9 Gy were administered in 1.67, 5, 10, 15, and 20 days. Colony growth was monitored for at least 60 days after completion of irradiation. Wells with confluent colonies were considered as 'recurrences' and wells without colonies as 'controlled'. The dose required to control 50% of irradiated wells (WCD{sub 50}) was estimated by a logistic regression for the different overall treatment times. The effective doubling time of clonogenic cells (T{sub eff}) was determined by a direct fit using the maximum likelihood method. Results: The increase of WCD{sub 50} within 18.3 days was highly significant for all tumor cell lines accounting for 7.9 and 12.0 Gy in the two glioblastoma cell lines and for 12.7, 14.0, and 21.7 Gy in the three SCC cell lines. The corresponding T{sub eff}s were 4.4 and 2.0 days for glioblastoma cell lines and 2.4, 4.2, and 1.8 days for SCC cell lines. Population doubling times (PDT) of untreated tumor cells ranged from 1.0 to 1.9 days, showing no correlation with T{sub eff}s. T{sub eff} was significantly longer than PDT in three of five tumor cell lines. No significant differences were observed comparing glioblastomas and SCC. Increase of WCD{sub 50} with time did not correlate with T{sub eff} but with T{sub eff}* InSF2 (surviving fraction at 2 Gy). Conclusion: The intrinsic ability of SCC and glioblastoma cells to repopulate during fractionated irradiation could be demonstrated. Repopulation induced dose loss per day depends on T{sub eff} and intrinsic radiation sensitivity. Proliferation during treatment was

  17. G2 arrest and apoptosis of cultured Raji cells by continuous low dose rate beta irradiation therapy with 188Re-perrhenate

    International Nuclear Information System (INIS)

    Yim, S. J.; Kim, E. H.; Lee, T. S.; Woo, K. S.; Jeong, W. S.; Choi, C. W.; Yim, S. M.

    2001-01-01

    Beta emitting radionuclide therapy gives exponentially decreasing radiation dose rate and results in cell death presumably by apoptosis. We observed changes in DNA content and apoptosis in relatively low dose rate beta irradiation. Raji cells were cultured and incubated with 188Re-perrhenate (3.7MBq, or 370MBq/ml) for 4 hours to give irradiation dose of 0.4, 4, or 40 Gy. After changing the culture media, cells were cultured for 2,4,8,16, and 24 hours. The cells were stained with Trypan blue, Annexin-V and Propidium Iodide (PI) to observe cell viability, cell membrane alternation by apoptosis and changes in DNA content respectively. Flowcytometry was done for Annexin-V and PI to quantitate apoptosis and necrosis in the irradiated cells. DAPI(4,6-diamidino-2-phenylindole) stain was also done to observe the damage in the nucleus. Cell viability decreased with an increasing radiation dose. Cells irradiated in 40 Gy showed early uptake of both Annexin-V and PI suggesting cell death by necrosis. Cells irradiated in 0.4 Gy showed delayed uptake of Annexin-V only, and later on PI uptake suggesting cell death mainly by apoptosis. The cells irradiated in 0.4 Gy showed G2 arrest in 16 hours after irradiation, but the cells irradiated in 40 Gy showed early DNA fragmentation within 2 hours after irradiation. In DAPI stain, early nucleus damage was observed in the cells irradiated in 40 Gy. On the other hand, slowly increasing apoptotic bodies were observed in the cells irradiated in 0.4 Gy. These results suggest that continuous low-dose irradiation induces G2 arrest and progressive apoptosis in cells while continuous high-dose irradiation induces rapid necrosis. Therefore, we expect therapeutic effect by continuous low-dose rate irradiation with beta emitting radiopharmaceuticals

  18. Deficient repair and degradation of DNA in X-irradiated L5178Y S/S cells: cell-cycle and temperature dependence

    International Nuclear Information System (INIS)

    Ueno, A.M.; Goldin, E.M.; Cox, A.B.; Lett, J.T.

    1979-01-01

    The rejoining of DNA strand breaks induced by X rays in the radiosensitive S/S variant of the L5178Y murine leukemic lymphoblast has been studied by alkaline-EDTA-sucrose sedimentation using swinging-bucket and zonal rotors. After irradiation, incubation resulted in an increase in DNA size, but the DNA structures were not restored in all cells, even when the x-ray dose was only 50 rad. Subsequently, 10 to 20 h after irradiation, heavily degraded DNA began to appear. When cells were irradiated at different parts of the cycle, the extent of DNA degradation varied in a fashion similar to survival: Least DNA degradation was found after irradiation at the most radioresistant stage (G 1 + 8 h), and most DNA degradation occurred after irradiation at the radiosensitive stage (G 1 ). Changes in cell survival caused by postirradiation hypothermia were also reflected in the extent of DNA degradation. Populations of G 1 cells, which show marked increases in survival after postirradiation hypothermic exposure, exhibited a lower level of DNA degradation, whereas populations of G 1 + 8 h cells, whose survival is affected little by postirradiation hypothermia, showed limited changes in DNA degradation. The onset of degradation was delayed by hypothermia in all cases

  19. Immunologic effects of whole body ultraviolet (uv) irradiation. II. Defect in splenic adherent cell antigen presentation for stimulation of T cell proliferation

    International Nuclear Information System (INIS)

    Letvin, N.L.; Fox, I.J.; Greene, M.I.; Benacerraf, B.; Germain, R.N.

    1980-01-01

    Ultraviolet (uv) irradiation has been shown to alter many parameters of the immunologic reactivity of mice. The altered responsiveness of uv-irradiated mice, as measured by delayed-type hypersensitivity (DTH) and primary in vitro plaque-forming cell (PFC) responses to T-dependent antigens, has recently been correlated with a functional defect in the splenic adherent cell population of these animals. The present studies describe a model of this altered responsiveness, which allows further clarification of the effects of external uv irradiation on the splenic antigen-presenting cell (APC) in its interactions with T cells

  20. AECL hot-cell facilities and post-irradiation examination services

    International Nuclear Information System (INIS)

    Schankula, M.H.; Plaice, E.L.; Woodworth, L.G.

    1998-04-01

    This paper presents an overview of the post-irradiation examination (PIE) services available at AECL's hot-cell facilities (HCF). The HCFs are used primarily to provide PIE support for operating CANDU power reactors in Canada and abroad, and for the examination of experimental fuel bundles and core components irradiated in research reactors at the Chalk River Laboratories (CRL) and off-shore. A variety of examinations and analyses are performed ranging from non-destructive visual and dimensional inspections to detailed optical and scanning electron microscopic examinations. Several hot cells are dedicated to mechanical property testing of structural materials and to determine the fitness-for-service of reactor core components. Facility upgrades and the development of innovative examination techniques continue to improve AECL's PIE capabilities. (author)

  1. AECL hot-cell facilities and post-irradiation examination services

    International Nuclear Information System (INIS)

    Schankula, M.H.; Plaice, E.L.; Woodworth, L.G.

    1995-01-01

    This paper presents an overview of the post-irradiation examination (PIE) services available at AECL's hot-cell facilities (HCF). The HCFs are used primarily to provide PIE support for operating CANDU power reactors in Canada and abroad, and for the examination of experimental fuel bundles and core components irradiated in research reactors at the Chalk River Laboratories (CRL) and off-shore. A variety of examinations and analysis are performed ranging from non-destructive visual and dimensional inspections to detailed optical and scanning electron microscopic examinations. Several hot cells are dedicated to mechanical property testing of structural materials and to determine the fitness-for-service of reactor core components. Facility upgrades and the development of innovative examination techniques continue to improve AECL's PIE capabilities. (author)

  2. Cell and tissue kinetics of the subependymal layer in mouse brain following heavy charged particle irradiation

    International Nuclear Information System (INIS)

    Manley, N.B.

    1988-01-01

    The following studies investigate the cellular response and cell population kinetics of the subependymal layer in the mouse brain exposed to heavy charged particle irradiation. Partial brain irradiation with helium and neon ions was confined to one cortex of the brain. Both the irradiated and the unirradiated contralateral cortex showed similar disturbances of the cell and tissue kinetics in the subependymal layers. The irradiated hemisphere exhibited histological damage, whereas the unirradiated side appeared normal histologically. The decrease in the values of the labeling indices 1 week after charged particle irradiation was dose- and ion-dependent. Mitotic indices 1 week after 10 and 25 Gy helium and after 10 Gy neon were the same as those seen in the control mice. Analysis of cell kinetics 1 week after 10 Gy helium and 10 Gy neon irradiation suggests the presence of a progenitor subpopulation that is proliferating with a shorter cell cycle. Comparison of the responses to the different charged particle beams indicates that neon ions are more effective in producing direct cellular damage than the helium ions, but the surviving proliferating cells several divisions later continue to maintain active cell renewal. Based on the 1 week post-irradiation H 3 -TdR labeling indices, a rough estimate of the RBE for neon ions is at least 2.5 when compared to helium ions

  3. Hormonal protection of spermatogenic stem cells during irradiation

    International Nuclear Information System (INIS)

    Kroonenburgh, M.J.P.G. van.

    1986-01-01

    In this thesis it is examined if by hormonal suppression of spermatogenesis the disadvantageous side-effects of radiation therapy on the gonads can be reduced. Therefore a rat model was investigated, where hormonal suppression of spermatogenesis during irradiation was achieved and stem cell survival was measured. Attention was focussed on the stem cell, because this cell is primarily responsible for the late effects of radiation on fertility. Flow cytometrical and histological techniques were used as parameters for measuring stem cell survival. Serum concentrations of FSH, LH and testosterone were measured to evaluate the hormonal suppression. (Auth.)

  4. Hyperkalemia after irradiation of packed red blood cells: Possible effects with intravascular fetal transfusion

    International Nuclear Information System (INIS)

    Thorp, J.A.; Plapp, F.V.; Cohen, G.R.; Yeast, J.D.; O'Kell, R.T.; Stephenson, S.

    1990-01-01

    Plasma potassium, calcium, and albumin concentrations in irradiated blood, and in fetal blood before and after transfusion, were measured. Dangerously high plasma potassium levels were observed in some units of irradiated packed red blood cells (range, 13.9 to 66.5 mEq/L; mean, 44.7 mEq/L) and could be one possible explanation for the high incidence of fetal arrhythmia associated with fetal intravascular transfusion. There are many factors operative in the preparation of irradiated packed red blood cells that may predispose to high potassium levels: the age of the red blood cells, the number of procedures used to concentrate the blood, the duration of time elapsed from concentration, the duration of time elapsed from irradiation, and the hematocrit. Use of fresh blood, avoidance of multiple packing procedures, limiting the hematocrit in the donor unit to less than or equal to 80%, and minimizing the time between concentration, irradiation and transfusion may minimize the potassium levels, and therefore making an additional washing procedure unnecessary

  5. BlueBerry Isolate, Pterostilbene, Functions as a Potential Anticancer Stem Cell Agent in Suppressing Irradiation-Mediated Enrichment of Hepatoma Stem Cells

    Directory of Open Access Journals (Sweden)

    Chi-Ming Lee

    2013-01-01

    Full Text Available For many malignancies, radiation therapy remains the second option only to surgery in terms of its curative potential. However, radiation-induced tumor cell death is limited by a number of factors, including the adverse response of the tumor microenvironment to the treatment and either intrinsic or acquired mechanisms of evasive resistance, and the existence of cancer stem cells (CSCs. In this study, we demonstrated that using different doses of irradiation led to the enrichment of CD133+ Mahlavu cells using flow cytometric method. Subsequently, CD133+ Mahlavu cells enriched by irradiation were characterized for their stemness gene expression, self-renewal, migration/invasion abilities, and radiation resistance. Having established irradiation-enriched CD133+ Mahlavu cells with CSC properties, we evaluated a phytochemical, pterostilbene (PT, found abundantly in blueberries, against irradiation-enriched CSCs. It was shown that PT treatment dose-dependently reduced the enrichment of CD133+ Mahlavu cells upon irradiation; PT treatment also prevented tumor sphere formation, reduced stemness gene expression, and suppressed invasion and migration abilities as well as increasing apoptosis of CD133+ Mahlavu CSCs. Based on our experimental data, pterostilbene could be used to prevent the enrichment of CD133+ hepatoma CSCs and should be considered for future clinical testing as a combined agent for HCC patients.

  6. Electron microbeam specifications for use in cell irradiation experiments

    International Nuclear Information System (INIS)

    Kim, E.-H.; Choi, M.-C.; Lee, D.-H.; Chang, M.; Kang, C.-S.

    2003-01-01

    The microbeam irradiation system was devised originally to identify the hit and unhit cells by confining the beam within the target cell. The major achievement through the microbeam experiment studies has turned out to be the discovery of the 'bystander effect'. Microbeam experiments have been performed with alpha and proton beams in major and with soft x-rays in minor. The study with electron microbeam has been deferred mainly due to the difficulty in confining the electron tracks within a single target cell. In this paper, the electron microbeam irradiation system under development in Korea is introduced in terms of the beam specifications. The KIRAMS electron microbeam irradiation system consists of an electron gun, a vacuum chamber for beam collimation into 5 μm in diameter and a biology stage. The beam characteristics in terms of current and energy spectrum of the electrons entering a target cell and its neighbor cells were investigated by Monte Carlo simulation for the electron source energies of 25, 50, 75 and 100 keV. Energy depositions in the target cell and the neighbor cells were also calculated. The beam attenuation in current and energy occurs while electrons pass through the 2 μm-thick Mylar vacuum window, 100 μm-thick air gap and the 2 μm-thick Mylar bottom of cell dish. With 25 keV electron source, 80 % of decrease in current and 30 % of decrease in average energy were estimated before entering the target cell. With 75 keV electron source, on the other hand, 55 % of decrease in current and less than 1 % of decrease in average energy were estimated. Average dose per single collimated electron emission was 0.067 cGy to the target cell nucleus of 5 μm in diameter and 0.030 cGy to the cytoplasm of 2.5 μm in thickness with 25 keV electron source while they were 0.15 cGy and 0.019 cGy, respectively, with 75 keV electron source. The multiple scattering of electrons resulted in energy deposition in the neighbor cells as well. Dose to the first

  7. Irradiation-induced up-regulation of HLA-E on macrovascular endothelial cells confers protection against killing by activated natural killer cells.

    Directory of Open Access Journals (Sweden)

    Isabelle Riederer

    Full Text Available BACKGROUND: Apart from the platelet/endothelial cell adhesion molecule 1 (PECAM-1, CD31, endoglin (CD105 and a positive factor VIII-related antigen staining, human primary and immortalized macro- and microvascular endothelial cells (ECs differ in their cell surface expression of activating and inhibitory ligands for natural killer (NK cells. Here we comparatively study the effects of irradiation on the phenotype of ECs and their interaction with resting and activated NK cells. METHODOLOGY/PRINCIPAL FINDINGS: Primary macrovascular human umbilical vein endothelial cells (HUVECs only express UL16 binding protein 2 (ULBP2 and the major histocompatibility complex (MHC class I chain-related protein MIC-A (MIC-A as activating signals for NK cells, whereas the corresponding immortalized EA.hy926 EC cell line additionally present ULBP3, membrane heat shock protein 70 (Hsp70, intercellular adhesion molecule ICAM-1 (CD54 and HLA-E. Apart from MIC-B, the immortalized human microvascular endothelial cell line HMEC, resembles the phenotype of EA.hy926. Surprisingly, primary HUVECs are more sensitive to Hsp70 peptide (TKD plus IL-2 (TKD/IL-2-activated NK cells than their immortalized EC counterpatrs. This finding is most likely due to the absence of the inhibitory ligand HLA-E, since the activating ligands are shared among the ECs. The co-culture of HUVECs with activated NK cells induces ICAM-1 (CD54 and HLA-E expression on the former which drops to the initial low levels (below 5% when NK cells are removed. Sublethal irradiation of HUVECs induces similar but less pronounced effects on HUVECs. Along with these findings, irradiation also induces HLA-E expression on macrovascular ECs and this correlates with an increased resistance to killing by activated NK cells. Irradiation had no effect on HLA-E expression on microvascular ECs and the sensitivity of these cells to NK cells remained unaffected. CONCLUSION/SIGNIFICANCE: These data emphasize that an irradiation

  8. Treating cell culture media with UV irradiation against adventitious agents: minimal impact on CHO performance.

    Science.gov (United States)

    Yen, Sandi; Sokolenko, Stanislav; Manocha, Bhavik; Blondeel, Eric J M; Aucoin, Marc G; Patras, Ankit; Daynouri-Pancino, Farnaz; Sasges, Michael

    2014-01-01

    Sterility of cell culture media is an important concern in biotherapeutic processing. In large scale biotherapeutic production, a unit contamination of cell culture media can have costly effects. Ultraviolet (UV) irradiation is a sterilization method effective against bacteria and viruses while being non-thermal and non-adulterating in its mechanism of action. This makes UV irradiation attractive for use in sterilization of cell culture media. The objective of this study was to evaluate the effect of UV irradiation of cell culture media in terms of chemical composition and the ability to grow cell cultures in the treated media. The results showed that UV irradiation of commercial cell culture media at relevant disinfection doses impacted the chemical composition of the media with respect to several carboxylic acids, and to a minimal extent, amino acids. The cumulative effect of these changes, however, did not negatively influence the ability to culture Chinese Hamster Ovary cells, as evaluated by cell viability, growth rate, and protein titer measurements in simple batch growth compared with the same cells cultured in control media exposed to visible light. © 2014 The Authors. Published by Wiley Periodicals, Inc. on behalf of American Institute of Chemical Engineers.

  9. Delayed K562 cell apoptosis promoted by cleaved LyGDI after 60Co γ-rays irradiation

    International Nuclear Information System (INIS)

    Sun Huali; Duan Weiming; Shao Yanyan; Xiao Hainan; Zhou Xinwen

    2010-01-01

    Objective: To elucidate the function and regulatory mechanism of LyGDI involved delayed cell death in the human K562 cells and HL-60 cells induced by 60 Co γ-rays. Methods: Erythrosine B cells staining was used to count the apoptosis rate. PI staining and flow cytometry were applied to check the cell cycle. The expression of LYGDI and Rac1 was resolved by Western blot by using monoclonal antibody of LyGDI and Rac1. The distribution of Rac1 protein in cells was observed with immunofluorescence by using the confocal microscope. Results: The K562 cells showed G 2 /M phase arrest and the percent age was 71.3%. The apoptosis rate was very low at early post-irradiation stage in the K562 cells. The apoptosis rate was 14% in the K562 cells at 24 h post-irradiation with 8 Gy of γ-rays, and delayed cell apoptosis was present. LyGDI was cleaved in the K562 cells irradiated by 4 Gy 60 Co γ-rays after 24 hours post-irradiation. The expression of Rac1 protein was not altered at all, but the distribution was changed in the irradiated cells while the Rac1 protein moved to cell membrane and a little in cell nucleus. The Rac1 was activated with the losing the binding affinity with the LyGDI. Conclusion: LyGDI could promote the delayed cell apoptosis, which is through the activation of the Rac1. (authors)

  10. Changes in T cell populations due to local irradiation of a portion of the maxilla in mice

    International Nuclear Information System (INIS)

    Satoh, Daigo

    1997-01-01

    The aim of this study was to investigate the changes in the immune organs after head and neck irradiation. The numbers of lymphocytes in peripheral blood, the spleen and the thymus following local irradiation of a portion of the maxilla in mice were studied using three-color fluorometry and were compared with a non-irradiation group. In the peripheral blood, the absolute numbers of T cells, CD4 + SP cells and CD8 + SP cells decreased after irradiation, and the period of the decrease was longer than the decreases in number of leukocytes and lymphocytes. The ratio of CD4 + SP cells showed a significant decrease, and the ratio of CD8+ S P cells showed a significant increase 1 day after irradiation. In the spleen, the absolute number of T cells, the radio of CD4 + SP and CD8 + SP cell subsets showed a decrease, and the period of the decrease was longer than the decrease of the wet-weight of the spleen, and also longer than the decrease of the number of leukocytes. The number of CD4 + SP cells showed a signigicant increase, and CD8 + SP cells showed a significant decrease 21 days after irradiation. In the thymus, the absolute number of TCR αβ-thymocytes did not show a significant decrease. However, the number of DN thymocytes showed a marked decrease. These results indicate that the numbers of T cells in peripheral blood, the spleen and the thymus change immediately after irradiation, and the numbers of lymphocytes and the T cells in the spleen recover more slowly than that in the peripheral blood. As lymphoid tissues showed the suppression of immunological response for a long period, it was suggested that lymphoid tissues have to be observed carefully after irradiation to prevent cancer metastasis. (K.H.)

  11. Photo irradiation Systems for In-Vitro Cultured Cells Phototherapy and Photobiology Experiments

    International Nuclear Information System (INIS)

    Serrano Navarro, Joel; Morales Lopez, Orestes M.; Hernandez Quintanas, Luis F.; Lopez Silva, Y.; Fabila Bustos, Diego A.; De la Rosa Vazquez, Jose M.; Valor Reed, Alma; Stolik Isakina, Suren; Brodin, Patrik N.; Guha, Chandan; Tome, Wolfgang A.

    2016-01-01

    The increase in research and application of various phototherapy methods, especially photodynamic therapy (PDT) has created the need to study in depth the mechanisms of interaction of light with biological tissue using a photosensitizing drug in order to increase the therapeutic effectiveness. In this issue, two systems for controlled irradiation of in-vitro cell culture and temperature monitoring of the culture are presented. The first system was designed to irradiate 24 wells in a 96-well microplate. The second one was constructed for the irradiation and control of a 24-well microplate using larger volumes of cultured cells. Both systems can independently irradiate and control the temperature of each well. The systems include a module for contactless measurement of the temperature in each well. Light sources are located in an interchangeable module, so that it can be replaced to irradiate with different wavelengths. These prototypes count with various operation modes, controlled by a computer, which permits establishing specific settings in accordance with the desired experiment. The systems allow the automated experiment execution with precise control of dosimetry, irradiation and temperature, which reduces the sample-handling while, saves time. (Author)

  12. Cytogenetic characterization of low-dose hyper-radiosensitivity in Cobalt-60 irradiated human lymphoblastoid cells

    Energy Technology Data Exchange (ETDEWEB)

    Joshi, Gnanada S. [Department of Biological Sciences, Wayne State University, Detroit, MI 48202 (United States); Joiner, Michael C. [Department of Radiation Oncology, Wayne State University, Detroit, MI 48201 (United States); Tucker, James D., E-mail: jtucker@biology.biosci.wayne.edu [Department of Biological Sciences, Wayne State University, Detroit, MI 48202 (United States)

    2014-12-15

    Highlights: • Human cells were irradiated in G1 or G2 and evaluated for micronuclei and bridges. • Cells irradiated in G2 but not in G1 exhibit low dose hyper-radiosensitivity. • Response curves of cells irradiated in G2 do not fit a linear-no-threshold model. • Response curves of cells irradiated in G1 fit a linear-no-threshold model. - Abstract: The dose-effect relationships of cells exposed to ionizing radiation are frequently described by linear quadratic (LQ) models over an extended dose range. However, many mammalian cell lines, when acutely irradiated in G2 at doses ≤0.3 Gy, show hyper-radiosensitivity (HRS) as measured by reduced clonogenic cell survival, thereby indicating greater cell lethality than is predicted by extrapolation from high-dose responses. We therefore hypothesized that the cytogenetic response in G2 cells to low doses would also be steeper than predicted by LQ extrapolation from high doses. We tested our hypothesis by exposing four normal human lymphoblastoid cell lines to 0–400 cGy of Cobalt-60 gamma radiation. The cytokinesis block micronucleus assay was used to determine the frequencies of micronuclei and nucleoplasmic bridges. To characterize the dependence of the cytogenetic damage on dose, univariate and multivariate regression analyses were used to compare the responses in the low- (HRS) and high-dose response regions. Our data indicate that the slope of the response for all four cell lines at ≤20 cGy during G2 is greater than predicted by an LQ extrapolation from the high-dose responses for both micronuclei and bridges. These results suggest that the biological consequences of low-dose exposures could be underestimated and may not provide accurate risk assessments following such exposures.

  13. Low dose ultraviolet B-irradiated Langerhans cells preferentially activate CD4+ cells of the T helper 2 subset

    International Nuclear Information System (INIS)

    Simon, J.C.; Cruz, P.D. Jr.; Bergstresser, P.R.; Tigelaar, R.E.

    1990-01-01

    UVB radiation distorts the Ag-presenting function of epidermal Langerhans cells (LC); this has been shown for the presentation of soluble Ag to primed T cells in vitro and for the initiation of delayed-type hypersensitivity in vivo, such as contact hypersensitivity (CH). Previous work has also demonstrated UVB-induced suppression of CH to be mediated ultimately by T cells. Two subsets of CD4+ Th cells, Th1 and Th2, have been identified, based on their cytokine production and functional activities. In particular, Th1 mediate delayed-type hypersensitivity, whereas Th2 do not. To investigate whether the perturbation of LC function induced by UVB radiation leads to a differential activation of these subsets of CD4+ cells, we examined the capacity of unirradiated and irradiated (200 J/m2) APC from adult BALB/c mice to present keyhole limpet hemocyanin to Ag-specific, H2d-restricted Th1 and Th2 cell lines. Four sources of APC were utilized: epidermal cells (EC), flow microfluorometry-purified Ia+ EC (LC), flow microfluorometry-purified Ia- EC, and splenic adherent cells (SAC). Unirradiated EC, LC, and SAC, but not Ia-EC, presented keyhole limpet hemocyanin to both Th1 and Th2. Irradiated EC and LC lost their ability to stimulate Th1, but retained fully their capacity to stimulate Th2. On the other hand, irradiated SAC were unable to induce proliferation of either Th1 or Th2. These findings indicate that suppression of CH mediated by UVB-irradiated LC may result from an alteration of the ratio and/or activity of Th1 and Th2 cells normally generated during the induction of such responses

  14. Effects of X-irradiation on cell-cycle progression, induction of chromosomal aberrations and cell killing in ataxia telangiectasia (AT) fibroblasts

    International Nuclear Information System (INIS)

    Nagasawa, H.; Little, J.B.; Latt, S.A.; Lalande, M.E.

    1985-01-01

    Survival, cumulative labeling indices, chromosomal aberrations and cell-cycle distribution by flow microfluorometry (FMF) were studied in fibroblasts from normal and three ataxia telangiectasia (AT) families after X-irradiation during density-inhibition of growth and immediate release by subculture to low density. Homozygotic AT (proband) fibroblasts were very hypersensitive to cell killing by X-irradiation. Fibroblasts from AT heterozygotes (parents) were minimally hypersensitive, with D 0 's slightly lower than those for normal fibroblasts. There were three different response groups for a G 1 phase block induced by 400 rad of X-rays: (1) minimal or no G 1 block was observed in AT homozygote cell strains; (2) 10-20% of the cells were blocked in G 1 in normal cell strains; and (3) 50% or more of the cells were blocked in AT heterozygote strains. FMF profiles and cumulative labeling indices showed that homozygotic AT cells irradiated in plateau phase moved into the S-phase following subculture with no additional delay over non-irradiated controls. Homozygotic AT cells showed not only a 4-5 times higher frequency of X-ray-induced chromosomal aberrations than normal strains, but approximately 30% of these were of the chromatid-type. There were no differences in the frequency or type of X-ray-induced chromosomal aberrations between normal and heterozygotic AT cells. (orig.)

  15. Response of S. boulardii cells to 60 Co irradiation and heat shock

    International Nuclear Information System (INIS)

    Neves, M.J.; Andrade, A.S.R.; Santos, R.G.; Nicoli, J.R.

    1997-01-01

    Full text. Preparation of Saccharomyces boulardii, a non pathogenic yeast, has been widely used in Europe and other countries to prevent gastrointestinal disorders. However the mechanism of action of theses cells on the illness is unknown but the efficacy of S. boulardii depends on its viability. As trehalose is a well known viability protectant in yeast cells against several adverse conditions, we determined its level. We measured the level of trehalose in cells submitted to heat shock, gamma irradiation and simulation of gastric environmental, all these conditions are commonly found during the bio therapeutic production and in the patients oral treatment. Trehalose levels were higher in yeast cells surviving to gamma irradiation ( 60 Cobalt) than in control cells. S. boulardii cells growth in log phase and submitted to the heat shock (40 deg C). Accumulated more trehalose than S. cerevisiae and unlikely to these cells, the pool of trehalose accumulated in S. boulardii was mobilized very slowly (70% of the trehalose pool was present 5 hours after the return to the normal temperature 30 deg C). Our results suggested a rather different trehalose metabolism in S. boulardii when compared with S. cerevisiae and showed that one of the response to the stress of irradiation was an increasing on the level of intracellular trehalose

  16. Variation in sensitizing effect of caffeine in human tumour cell lines after γ-irradiation

    International Nuclear Information System (INIS)

    Valenzuela, M.T.; Almodovar, M.R. de; Mateos, S.; McMillan, T.J.

    2000-01-01

    We have investigated whether the protective role of the G2 checkpoint has increasing importance when the p53-dependent G1 checkpoint is inactivated. We have studied the differential effect of caffeine by clonogenic assays and flow cytometry in three human tumour cell lines with different functionality of p53 protein. The radiosensitizing effect of caffeine (2 mM) expressed itself as a significant decrease in surviving fraction at 2 Gy and a significant increase in α-values in RT112 and TE671, both with non-functional p53. However, no radiosensitizing effect was seen in cells with a normal p53 function (MCF-7 BUS). Two millimoles of caffeine also caused important changes in the cell cycle progression after irradiation. MCF-7 BUS showed a G1 arrest after irradiation and an early G2 arrest but those cells that reached the second G2 did not arrest significantly. In contrast, TE671 exhibited radiosensitization by caffeine, no G1 arrest, a G2 arrest in those cells irradiated in G2, no significant accumulation in the second G2 but an overall delay in release from the first cell cycle, which could be abrogated by caffeine. RT112 was similar to TE671 except that the emphasis in a G2 arrest was shifted from the block in cells irradiated in G2 to those irradiated at other cell cycle phases. The data presented confirm that p53 status can be a significant determinant of the efficacy of caffeine as radiosensitizer in these tumour cell lines, and document the importance of the G2 checkpoint in this effect. (author)

  17. Survival of human osteosarcoma cells and normal human fibroblasts following alpha particle irradiation

    International Nuclear Information System (INIS)

    Lloyd, E.L.; Gemmell, M.A.

    1981-01-01

    Cell survival of human osteosarcoma cells in culture following alpha particle irradiation is reported here for the first time. The osteosarcoma cell line (TE-85) is found to be less sensitive to inactivation by 5.6 MeV alpha particles (LET 86 keV/μm) than normal diploid human fibroblasts (NFS). Values for the mean lethal doses were estimated to be 103 rads for the TE-85 cells compared with 68 rads for the NFS cultures irradiated under identical conditions. It is postulated that the aneuploidy of the tumor cells with increased DNA chromosomal material may confer a selective advantage for the survival of tumor cells relative to normal cells with diploid chromosomes

  18. Total lymphoid irradiation and total body irradiation for allogeneic bone marrow transplantation in aplastic anemia

    Energy Technology Data Exchange (ETDEWEB)

    Kurisu, Koichi; Hishikawa, Yoshio; Taniguchi, Midori; Kamikonya, Norihiko; Miura, Takashi; Kanamaru, Akihisa; Kakishita, Eizo; Kai, Shunro; Hara, Hiroshi (Hyogo Coll. of Medicine, Nishinomiya (Japan))

    Between April 1980 and June 1989, 15 patients with severe aplastic anemia (SAA) were treated at Hyogo College of Medicine with bone marrow transplantation (BMT) after preparation consisting of cyclophosphamide (CY) and total lymphoid irradiation (TLI) or total body irradiation (TBI) for the purpose of reducing the incidence of graft rejection. All patients had initial evidence of engraftment after the first transplantation except for one patient who died of heart failure due to CY on the third day after transplantation and could not be evaluated for engraftment. Rejection later occurred in four of these 14 patients, who then underwent successful regrafting. One of these four patients, who was conditioned with CY alone at the first grafting, underwent successful regrafting after a conditioning regimen of CY and TBI. In the other three patients, irradiation was performed twice as the conditioning regimen. Thus, 14 of 15 patients underwent successful BMT and are alive with restored hematopoietic function. From the above results, the combination of TLI or TBI and CY was considered to be very useful as a conditioning regimen for BMT in patients with SAA. (author).

  19. Displacement damage analysis and modified electrical equivalent circuit for electron and photon-irradiated silicon solar cells

    Science.gov (United States)

    Arjhangmehr, Afshin; Feghhi, Seyed Amir Hossein

    2014-10-01

    Solar modules and arrays are the conventional energy resources of space satellites. Outside the earth's atmosphere, solar panels experience abnormal radiation environments and because of incident particles, photovoltaic (PV) parameters degrade. This article tries to analyze the electrical performance of electron and photon-irradiated mono-crystalline silicon (mono-Si) solar cells. PV cells are irradiated by mono-energetic electrons and poly-energetic photons and immediately characterized after the irradiation. The mean degradation of the maximum power (Pmax) of silicon solar cells is presented and correlated using the displacement damage dose (Dd) methodology. This method simplifies evaluation of cell performance in space radiation environments and produces a single characteristic curve for Pmax degradation. Furthermore, complete analysis of the results revealed that the open-circuit voltage (Voc) and the filling factor of mono-Si cells did not significantly change during the irradiation and were independent of the radiation type and fluence. Moreover, a new technique is developed that adapts the irradiation-induced effects in a single-cell equivalent electrical circuit and adjusts its elements. The "modified circuit" is capable of modeling the "radiation damage" in the electrical behavior of mono-Si solar cells and simplifies the designing of the compensation circuits.

  20. The effect of whole body or total-head x irradiation of the metallophilic cells in the mice spleen

    International Nuclear Information System (INIS)

    Sasaki, Osamu; Matsueda, Yasutoshi; Mizuguchi, Hiroshi; Moriguchi, Kenzo; Ogata, Kunitoshi; Sugie, Tsuneto

    1984-01-01

    The purpose of this paper is to clarify morphological changes of the reticuloendothelial cells in the spleen following X-irradiation by Katsura's silver impregnation method. The animals used in this experiment were ddN female mice weighing 20 to 25g. The mice were given X-irradiation to the total-head (1,500R) or whole body (300R). The metallophilic cells in the spleen of control mice were of the small foamy type in the follicle, the large stellate type in the marginal metallophils, the small branching type in the marginal zone and the small foamy or round type in the red pulp, respectively. The metallophilic cells decreased immediately after whole body irradiation and the number of cells returned to normal in from 10 to 14 days. On the other hand, the number of the metallophilic cells in the follicle and the perifollicular region increased immediately after total-head X-irradiation. This state continued for several days. In the marginal zone and red pulp, the number of amoebian type cells appeared from 24 hours after irradiation and the number of cells in total-head irradiation group were more clearly distinguishable than in the whole body irradiated group. (author)

  1. Structure of cells chloroplasts and mitochondria of cotton leaves following gamma irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Arslanova, S V [AN Uzbekskoj SSR, Tashkent. Inst. Ehksperimental' noj Biologii Rastenij

    1975-01-01

    The article investigates the structural changes in the plastides and mitochondria of cotton leaf cells after irradiation. Cotton seeds that had been moistened for 24 hours were irradiated by a gamma source with a dose of 10 kR (intensity: 19 R/s.). For the study of the plastides and mitochondria of the leaf cells samples were taken in the cotyledonous leaf and flowering phases of the cotton. The cells of the cotton leaf mesophillum in the standard consists of chloroplast with developed interior structures. Study of the ultrastructure of the cells of the mesophilic tissue of the cotyledonous leaf in irradiated cotton plants showed that the chloroplastide membranes are not damaged. A change in the form of the chloroplasts, an accumulation of starch and plastic substances in the chloroplasts, and a reduction in the number of inter-grain bonds were noted. It was discovered that gamma irradiation produces an excessive build-up of starch in the chloroplasts. The mitochondria are often located close to the plastides. The optical density is typical of the matrix of the mitochondria in non-irradiated plants. After cotton seeds that have sprouted are irradiated with a dose of 10 kR in the cotyledonous leaf phase, part of the mitochondria swells. The matrix becomes more transparent, and the number of chrysts decreases. Part of the mitochondria remains intact. The optical density and internal membranes of the mitochondria remain the same as in the control group. The disturbances of the chloroplast and the mitochondria are also observed in the budding and flowering phases (under conditions of a natural day). It was noted that a shortened day facilitated to some extent a normalization of metabolism, and this produced in turn a normal development of the chloroplasts, leaf mitochondria and ATF generation, which reduces the final biological effect of the radiation.

  2. Comparison of thermoradiosensitization in two human melanoma cell lines and one fibroblast cell line by concurrent mild hyperthermia and low-dose-rate irradiation

    International Nuclear Information System (INIS)

    Raaphorst, G.P.; Bussey, A.; Heller, D.P.; Ng, C.E.

    1994-01-01

    Two human melanoma cell lines, one radioresistant (Sk-MEL-3) and one radiosensitive (HT-144), and a normal human fibroblast line (AG1522) were evaluated for thermoradiosensitization of low-dose-rate irradiation by concurrent mild hyperthermia (39-41 degrees C). None of the cell lines expressed chronic thermotolerance during heating at 39-41 degrees C. The SK-MEL-3 cells were the most heat sensitive, while AG1522 and HT-144 cells had the same sensitivity at 39 and 40 degrees C but HT-144 cells were more sensitive at 41 degrees C. All cell lines expressed thermal enhancement of radiosensitivity with heating during irradiation which increased with heating temperature. The SK-MEL-3 cells, which were the most resistant to radiation and demonstrated the greatest repair of sublethal damage (SLD) during low-dose-rate irradiation, had the greatest thermal enhancement of radiosensitivity, while the HT144 cells, which were the most sensitive and expressed little repair of SLD during low-dose-rate irradiation, had the smallest thermal enhancement of radiosensitivity. These data show that concurrent mild hyperthermia during low-dose-rate irradiation may be most efficacious in radiation-resistant tumor cells which express resistance through an enhanced capacity for repair of SLD. 24 refs., 5 figs., 1 tab

  3. Adhesion of thymus lymphocytes to aortic endothelial cells in rats irradiated with sup 60 Co-. gamma. -rays

    Energy Technology Data Exchange (ETDEWEB)

    Yongjian, Geng; Zijun, Mao; Zhiwei, Yin [Suzhou Medical Coll., JS (China)

    1990-03-01

    Adhesion of thymus lymphocytes to aortic endothelial cells in Wistar rats irradiated with {sup 60}Co-{gamma}-rays was preliminarily investigated with a stereological method. The results of experiments suggest that the number of lymphocytes of thymus which adhered to aortic endothelial cells significantly (p < 0.01) decreased after irradiation at doses of 2 and 8 Gy. However, when both thymus and aorta were irradiated, there were more lymphocytes adhering to endothelial cells than that when only thymus was irradiated.

  4. Simulation of limiting dilution technique in determination of immunocompetent cells frequency in irradiated cell cultures

    International Nuclear Information System (INIS)

    Martini Filho, R.J.; Barlette, V.E.; Goes, E.G.; Covas, D.T.; Orellana, M.

    2001-01-01

    Limiting dilution techniques (LDA) dose-response data have been used to detect immunocompetent T-Cells in microcultures. In this work, LDA frequencies estimates was obtained using χ2 minimization for irradiated cells in a range of 500 to 1,500 cGy. (author)

  5. The In Vitro Response of Tissue Stem Cells to Irradiation With Different Linear Energy Transfers

    Energy Technology Data Exchange (ETDEWEB)

    Nagle, Peter W.; Hosper, Nynke A. [Department of Cell Biology, University of Groningen, University Medical Center Groningen, Groningen (Netherlands); Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, Groningen (Netherlands); Ploeg, Emily M. [Department of Cell Biology, University of Groningen, University Medical Center Groningen, Groningen (Netherlands); Goethem, Marc-Jan van [Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, Groningen (Netherlands); KVI-Center for Advanced Radiation Research, University of Groningen, Groningen (Netherlands); Brandenburg, Sytze [KVI-Center for Advanced Radiation Research, University of Groningen, Groningen (Netherlands); Langendijk, Johannes A. [Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, Groningen (Netherlands); Chiu, Roland K. [Department of Cell Biology, University of Groningen, University Medical Center Groningen, Groningen (Netherlands); Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, Groningen (Netherlands); Coppes, Robert P., E-mail: r.p.coppes@umcg.nl [Department of Cell Biology, University of Groningen, University Medical Center Groningen, Groningen (Netherlands); Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, Groningen (Netherlands)

    2016-05-01

    Purpose: A reduction in the dose, irradiated volume, and sensitivity of, in particular, normal tissue stem cells is needed to advance radiation therapy. This could be obtained with the use of particles for radiation therapy. However, the radiation response of normal tissue stem cells is still an enigma. Therefore, in the present study, we developed a model to investigate the in vitro response of stem cells to particle irradiation. Methods and Materials: We used the immortalized human salivary gland (HSG) cell line resembling salivary gland (SG) cells to translate the radiation response in 2-dimensional (2D) to 3-dimensional (3D) conditions. This response was subsequently translated to the response of SG stem cells (SGSCs). Dispersed single cells were irradiated with photons or carbon ions at different linear energy transfers (LETs; 48.76 ± 2.16, 149.9 ± 10.8, and 189 ± 15 keV/μm). Subsequently, 2D or 3D clonogenicity was determined by counting the colonies or secondary stem cell-derived spheres in Matrigel. γH2AX immunostaining was used to assess DNA double strand break repair. Results: The 2D response of HSG cells showed a similar increase in dose response to increasing higher LET irradiation as other cell lines. The 3D response of HSG cells to increasing LET irradiation was reduced compared with the 2D response. Finally, the response of mouse SGSCs to photons was similar to the 3D response of HSG cells. The response to higher LET irradiation was reduced in the stem cells. Conclusions: Mouse SGSC radiosensitivity seems reduced at higher LET radiation compared with transformed HSG cells. The developed model to assess the radiation response of SGSCs offers novel possibilities to study the radiation response of normal tissue in vitro.

  6. The In Vitro Response of Tissue Stem Cells to Irradiation With Different Linear Energy Transfers

    International Nuclear Information System (INIS)

    Nagle, Peter W.; Hosper, Nynke A.; Ploeg, Emily M.; Goethem, Marc-Jan van; Brandenburg, Sytze; Langendijk, Johannes A.; Chiu, Roland K.; Coppes, Robert P.

    2016-01-01

    Purpose: A reduction in the dose, irradiated volume, and sensitivity of, in particular, normal tissue stem cells is needed to advance radiation therapy. This could be obtained with the use of particles for radiation therapy. However, the radiation response of normal tissue stem cells is still an enigma. Therefore, in the present study, we developed a model to investigate the in vitro response of stem cells to particle irradiation. Methods and Materials: We used the immortalized human salivary gland (HSG) cell line resembling salivary gland (SG) cells to translate the radiation response in 2-dimensional (2D) to 3-dimensional (3D) conditions. This response was subsequently translated to the response of SG stem cells (SGSCs). Dispersed single cells were irradiated with photons or carbon ions at different linear energy transfers (LETs; 48.76 ± 2.16, 149.9 ± 10.8, and 189 ± 15 keV/μm). Subsequently, 2D or 3D clonogenicity was determined by counting the colonies or secondary stem cell-derived spheres in Matrigel. γH2AX immunostaining was used to assess DNA double strand break repair. Results: The 2D response of HSG cells showed a similar increase in dose response to increasing higher LET irradiation as other cell lines. The 3D response of HSG cells to increasing LET irradiation was reduced compared with the 2D response. Finally, the response of mouse SGSCs to photons was similar to the 3D response of HSG cells. The response to higher LET irradiation was reduced in the stem cells. Conclusions: Mouse SGSC radiosensitivity seems reduced at higher LET radiation compared with transformed HSG cells. The developed model to assess the radiation response of SGSCs offers novel possibilities to study the radiation response of normal tissue in vitro.

  7. Enhancement of SPHK1 in vitro by carbon ion irradiation in oral squamous cell carcinoma

    International Nuclear Information System (INIS)

    Higo, Morihiro; Uzawa, Katsuhiro; Kawata, Tetsuya; Kato, Yoshikuni; Kouzu, Yukinao; Yamamoto, Nobuharu; Shibahara, Takahiko; Mizoe, Jun-etsu; Ito, Hisao; Tsujii, Hirohiko; Tanzawa, Hideki

    2006-01-01

    Purpose The purpose of this study was to assess the gene expression changes in oral squamous cell carcinoma (OSCC) cells after carbon ion irradiation. Methods and Materials Three OSCC cell lines (HSC2, Ca9-22, and HSC3) were irradiated with accelerated carbon ion beams or X-rays using three different doses. The cellular sensitivities were determined by clonogenic survival assay. To identify genes the expression of which is influenced by carbon ion irradiation in a dose-dependent manner, we performed Affymetrix GeneChip analysis with HG-U133 plus 2.0 arrays containing 54,675 probe sets. The identified genes were analyzed using the Ingenuity Pathway Analysis Tool to investigate the functional network and gene ontology. Changes in mRNA expression in the genes were assessed by real-time reverse transcriptase-polymerase chain reaction. Results We identified 98 genes with expression levels that were altered significantly at least twofold in each of the three carbon-irradiated OSCC cell lines at all dose points compared with nonirradiated control cells. Among these, SPHK1, the expression of which was significantly upregulated by carbon ion irradiation, was modulated little by X-rays. The function of SPHK1 related to cellular growth and proliferation had the highest p value (p = 9.25e-7 to 2.19e-2). Real-time reverse transcriptase-polymerase chain reaction analysis showed significantly elevated SPHK1 expression levels after carbon ion irradiation (p < 0.05), consistent with microarray data. Clonogenic survival assay indicated that carbon ion irradiation could induce cell death in Ca9-22 cells more effectively than X-rays. Conclusions Our findings suggest that SPHK1 helps to elucidate the molecular mechanisms and processes underlying the biologic response to carbon ion beams in OSCC

  8. Effect of Laser Irradiation on Cell Function and Its Implications in Raman Spectroscopy.

    Science.gov (United States)

    Yuan, Xiaofei; Song, Yanqing; Song, Yizhi; Xu, Jiabao; Wu, Yinhu; Glidle, Andrew; Cusack, Maggie; Ijaz, Umer Z; Cooper, Jonathan M; Huang, Wei E; Yin, Huabing

    2018-04-15

    Lasers are instrumental in advanced bioimaging and Raman spectroscopy. However, they are also well known for their destructive effects on living organisms, leading to concerns about the adverse effects of laser technologies. To implement Raman spectroscopy for cell analysis and manipulation, such as Raman-activated cell sorting, it is crucial to identify nondestructive conditions for living cells. Here, we evaluated quantitatively the effect of 532-nm laser irradiation on bacterial cell fate and growth at the single-cell level. Using a purpose-built microfluidic platform, we were able to quantify the growth characteristics, i.e., specific growth rates and lag times of individual cells, as well as the survival rate of a population in conjunction with Raman spectroscopy. Representative Gram-negative and Gram-positive species show similar trends in response to a laser irradiation dose. Laser irradiation could compromise the physiological function of cells, and the degree of destruction is both dose and strain dependent, ranging from reduced cell growth to a complete loss of cell metabolic activity and finally to physical disintegration. Gram-positive bacterial cells are more susceptible than Gram-negative bacterial strains to irradiation-induced damage. By directly correlating Raman acquisition with single-cell growth characteristics, we provide evidence of nondestructive characteristics of Raman spectroscopy on individual bacterial cells. However, while strong Raman signals can be obtained without causing cell death, the variety of responses from different strains and from individual cells justifies careful evaluation of Raman acquisition conditions if cell viability is critical. IMPORTANCE In Raman spectroscopy, the use of powerful monochromatic light in laser-based systems facilitates the detection of inherently weak signals. This allows environmentally and clinically relevant microorganisms to be measured at the single-cell level. The significance of being able to

  9. Indications of hematopoietic stem cell transplantations and therapeutic strategies of accidental irradiations

    International Nuclear Information System (INIS)

    2003-01-01

    Produced by a group of experts, this document first discusses the issue of accidental irradiations in terms of medical management. They notably outline the peculiar characteristics of these irradiations with respect to therapeutic irradiations. They agreed on general principles regarding casualty sorting criteria and process, and their medical treatment (systematic hematopoiesis stimulation, allogeneic transplantation of hematopoietic stem cells). They discuss some practical aspects of these issues: casualty sorting within a therapeutic perspective (actions to be performed within 48 hours), therapeutic strategies (support therapy, use of cytokines, and therapy by hematopoietic stem cell transplant). They state a set of recommendations regarding the taking into care and diagnosis, therapeutic strategies, research perspectives, and teaching

  10. Effect of cell phone-like electromagnetic radiation on primary human thyroid cells.

    Science.gov (United States)

    Silva, Veronica; Hilly, Ohad; Strenov, Yulia; Tzabari, Cochava; Hauptman, Yirmi; Feinmesser, Raphael

    2016-01-01

    To evaluate the potential carcinogenic effects of radiofrequency energy (RFE) emitted by cell phones on human thyroid primary cells. Primary thyroid cell culture was prepared from normal thyroid tissue obtained from patients who underwent surgery at our department. Subconfluent thyroid cells were irradiated under different conditions inside a cell incubator using a device that simulates cell phone-RFE. Proliferation of control and irradiated cells was assessed by the immunohistochemical staining of antigen Kiel clone-67 (Ki-67) and tumor suppressor p53 (p53) expression. DNA ploidy and the stress biomarkers heat shock protein 70 (HSP70) and reactive oxygen species (ROS) was evaluated by fluorescence-activated cell sorting (FACS). Our cells highly expressed thyroglobulin (Tg) and sodium-iodide symporter (NIS) confirming the origin of the tissue. None of the irradiation conditions evaluated here had an effect neither on the proliferation marker Ki-67 nor on p53 expression. DNA ploidy was also not affected by RFE, as well as the expression of the biomarkers HSP70 and ROS. Our conditions of RFE exposure seem to have no potential carcinogenic effect on human thyroid cells. Moreover, common biomarkers usually associated to environmental stress also remained unchanged. We failed to find an association between cell phone-RFE and thyroid cancer. Additional studies are recommended.

  11. The effect of X-ray irradiation on a red cell component in WB, WRC and LPRC

    International Nuclear Information System (INIS)

    Tayama, Tatsuya; Toyota, Kuroh; Nagahashi, Hisakata; Masuyama, Tetsuya; Haneda, Kenji; Juji, Takeo.

    1990-01-01

    In spite of the use of X-ray irradiation on blood products, few data about its effect on components are reported. We need more informations about a quality of irradiated red cell components. This study shows in vitro changes of irradiated red cell component in WB, WRC and LPRC as the minimum dose of 1,500, 3,000, and 5,000 rads. The fact as follows were observed in response to irradiated doses: 1) increased fragility of red cell membrane, 2) increased amount of plasma K and plasma Hb, and 3) decrease of ATP in WB.2,3-DPG, glucose, pH, Ht and Cl. The numbers of RBC, WBC and Platelet were not affected by irradiation with doses between 1,500 and 5,000 rads. According to these results, the followings are recommended: 1) irradiation with 1,500 rads is a proper method for WB, 2) in order to avoid the risk of increased plasma K, WB should be used within 1 week after irradiation, and WRC and LPRC should be used 24 hours after irradiation. (author)

  12. Phenotypic characterization of thymic prelymphoma cells of B10 mice treated with split-dose irradiation

    International Nuclear Information System (INIS)

    Muto, M.; Kubo, E.; Kamisaku, H.; Sado, T.

    1990-01-01

    Using an intrathymic injection assay on B10 Thy-1 congenic mice, it was demonstrated that thymic prelymphoma cells first developed within the thymuses from 4 to 8 days after split-dose irradiation and were detected in more than 63% of the test donor thymuses when examined at 21 and 31 days after irradiation. Moreover, some mice (25%) at 2 mo after split-dose irradiation had already developed thymic lymphomas in their thymuses. To characterize these thymic prelymphoma cells, the thymocytes from B10 Thy-1.1 mice 1 mo after irradiation were stained with anti-CD4 and anti-CD8 mAb and were sorted into four subpopulations. These fractionated cells were injected into the recipient thymuses to examine which subpopulation contained thymic prelymphoma cells. The results indicated that thymic prelymphoma cells existed mainly in CD4- CD8- and CD4- CD8+ thymocyte subpopulations and also in CD4+ CD8+ subpopulation. T cell lymphomas derived from CD4- CD8- prelymphoma cells had mainly CD4- CD8- or CD4- CD8+ phenotypes. T cell lymphomas developed from CD4- CD8+ prelymphoma cells mainly expressed CD4- CD8+ or CD4+ CD8+ phenotype. T cell lymphomas originating from CD4+ CD8+ prelymphoma cells were mainly CD4+ CD8+ but some CD4- CD8+ or CD4+ CD8- cells were also present. These thymic prelymphoma cells were further characterized phenotypically in relation to their expression of the marker defined by the mAb against J11d marker and TL-2 (thymus-leukemia) Ag, which is not expressed on normal thymocytes of B10.Thy-1.2 or B10.Thy-1.1 strain, but appears on the thymocytes of lymphomagenic irradiated mice. The results indicated that the prelymphoma cells existed in J11d+, TL-2+ cells

  13. Light scattering by irradiated cells as a method of biological dosimetry

    International Nuclear Information System (INIS)

    Ostashevsky, J.

    1984-01-01

    Light scattering (LS) parameters between 350-500 nm wavelength have been studied for 2 groups of cells: 1) blood (BL) and thymus (TL) lymphocytes of rats and mice, and 2) Ehrlich ascite tumor (EAT) cells. LS measurements of freshly prepared cell suspensions have been made 24 hrs after x-ray irradiation of rodents (250 Kev, HVL = 2 mm Cu) at doses of 50-900 cGy. A steep (30% per Gy) linear (50-800 cGy for TL and 50-400 cGy for BL) dose-dependence was obtained for the increase in 90 0 -angle LS intensity. Increase in absorption (low-angle LS) was also linear (50-800 cGy for TL and BL) but less steep (9% per Gy). Irradiated cells were the same size as unirradiated. Changes in LS for TL and BL appear to follow the appearance of additional vacuoles which may become new internal smaller-size centers of LS. This suggestion is supported by direct observations of cells with dark-field microscopy. For EAT cells, both 90 0 and low angle LS had the same slope. This slope (4% per Gy) is much shallower than that for BL and TL, and quantitatively coincides with enlargement of area of EAT cells, which could explain LS changes. The difference in LS behavior of the two cellular groups reflects a difference in their early response to irradiation: interphase death for TL and BL, vs division delay for EAT cells. The above data suggest the fast and simple method of biological dosimetry

  14. DNA synthesis in irradiated mammalian cells

    International Nuclear Information System (INIS)

    Painter, R.B.; California Univ., San Francisco; Young, B.R.

    1987-01-01

    One of the first responses observed in S phase mammalian cells that have suffered DNA damage is the inhibition of initiation of DNA replicons. In cells exposed to ionizing radiation, a single-strand break appears to be the stimulus for this effect, whereby the initiation of many adjacent replicons (a replicon cluster) is blocked by a single-strand break in any one of them. In cells exposed to ultraviolet light (u.v.), replicon initiation is blocked at fluences that induce about one pyrimidine dimer per replicon. The inhibition of replicon initiation by u.v. in Chinese hamster cells that are incapable of excising pyrimidine dimers from their DNA is virtually the same as in cells that are proficient in dimer excision. Therefore, a single-strand break formed during excision repair of pyrimidine dimers is not the stimulus for inhibition of replicon initiation in u.v.-irradiated cells. Considering this fact, as well as the comparative insensitivity of human ataxia telangiectasia cells to u.v.-induced inhibition of replicon initiation, we propose that a relatively rare lesion is the stimulus for u.v. -induced inhibition of replicon initiation. (author

  15. The effects of X-irradiation on ex vivo expansion of cryopreserved human hematopoietic stem/progenitor cells

    International Nuclear Information System (INIS)

    Hayashi, Naoki; Takahashi, Kenji; Kashiwakura, Ikuo

    2010-01-01

    In our previous study (Life Sciences 84: 598, 2009), we demonstrated that placental/umbilical cord blood-derived mesenchymal stem cell-like stromal cells have the effect to support the regeneration of freshly prepared X-irradiated hematopoietic stem/progenitor cells (HSPCs). Generally, HSPCs are supplied from companies, institutions, and cell banks that cryopreserve them for clinical and experimental use. In this study, the influence of cryopreservation on the responses of HSPCs to irradiation and co-culture with stromal cells is assessed. After cryopreservation with the optimal procedure, 2 Gy-irradiated HSPCs were cultured with or without stromal cells supplemented with combination of interleukin-3, stem cell factor, and thrombopoietin. The population of relatively immature CD34 + /CD38 - cells in cryopreserved cells was significantly higher than in fresh cells prior to cryopreservation; furthermore, the hematopoietic progenitor populations of CD34 + /CD45RA + cells and CD34 + /CD117 + cells in cryopreserved cells were significantly lower than that in fresh cells. However, the rate of expansion in the cryopreserved HSPCs was lower than in the fresh HSPCs. In the culture of cryopreserved cells irradiated with 2 Gy, the growth rates of CD34 + cells, CD34 + /CD38 - cells, and hematopoietic progenitors were greater than growth rates of their counter parts in the culture of fresh cells. Surprisingly, the effect to support the hematopoiesis in co-culture with stromal cells was never observed in the X-irradiated HSPCs after cryopreservation. The present results demonstrated that cryopreserving process increased the rate of immature and radio-resistant HSPCs but decreased the effects to support the hematopoiesis by stromal cells, thus suggesting that cryopreservation changes the character of HSPCs. (author)

  16. Unscheduled DNA synthesis in spleen cells of mice exposed to low doses of total body irradiation

    International Nuclear Information System (INIS)

    Tuschl, H.; Kovac, R.; Hruby, E.

    1983-07-01

    Unscheduled DNA synthesis was induced by UV irradiation of spleen cells obtained from C 57 Bl mice after repeated total body irradiation of 0.05 Gy 60 Co (0.00125 Gy/mice) and determined autoradiographically. An enhancement in the ability for repair of UV induced DNA lesions was observed in cells of gamma irradiated animals. While the amount of 3 H-thymidine incorporated per cell was increased, the percentage of labeled cells remained unchanged. The present results are compared with previous data on low dose radiation exposure in men. (Author) [de

  17. Characterization of membrane lipid fluidity in human embryo cells malignantly transfer med post 238Pu α irradiation

    International Nuclear Information System (INIS)

    Qi Zirong; Sun Ling; Liu Guolian; Shen Zhiyuan

    1992-01-01

    The membrane lipid fluidity of malignantly transformed human embryo cells following 238 Pu α particlce irradiation in vitro has been studied. The results indicate that the ontogenesis depends on irradiation dose (Gy) and the membrane lipid fluidity in malignantly transformed cells is higher than that in normal embryo cells. With the microviscosity (η) of cells plotted against the cell counts, the correlation coefficient (γ) is calculated to be between 0.9936 and 0.9999. Since the malignant transformation of irradiated embryo cells is manifested early on cell membrane lipid, the fluidity of membrane lipid can be used as an oncologic marker

  18. Suppressed histamine release from rat peritoneal mast cells by ultraviolet B irradiation: decreased diacylglycerol formation as a possible mechanism

    International Nuclear Information System (INIS)

    Danno, K.; Fujii, K.; Tachibana, T.; Toda, K.; Horio, T.

    1988-01-01

    This study was designed to investigate the effect of ultraviolet B (UVB) irradiation on mast cell functions. Purified mast cells obtained from rat peritoneal cavity were irradiated with UVB and subsequently exposed to a degranulator, compound 48/80, or the calcium ionophore A-23187. The amount of histamine released from mast cells measured by the enzyme isotopic assay was significantly decreased by UVB irradiation (100-400 mJ/cm2). Within this dose range, UVB alone was not cytotoxic to the cells because it did not induce histamine release. The suppression was observed when mast cells were subjected to degranulation without intervals after UVB irradiation, and even after 5 h postirradiation. The wavelength of 300 nm from a monochromatic light source showed the maximum effect. When mast cells prelabeled with [ 3 H]arachidonate were irradiated and challenged by compound 48/80, label accumulation in diacylglycerol produced by the phosphatidylinositol cycle was considerably decreased by UVB irradiation. From these results, we hypothesize that, within an adequate irradiation dose, UVB irradiation suppresses histamine release from mast cells, probably by causing noncytotoxic damage to the membrane phospholipid metabolism, which is tied to the degranulation mechanisms

  19. Whole body proton irradiation causes acute damage to bone marrow hematopoietic progenitor and stem cells in mice.

    Science.gov (United States)

    Chang, Jianhui; Wang, Yingying; Pathak, Rupak; Sridharan, Vijayalakshmi; Jones, Tamako; Mao, Xiao Wen; Nelson, Gregory; Boerma, Marjan; Hauer-Jensen, Martin; Zhou, Daohong; Shao, Lijian

    2017-12-01

    Exposure to proton irradiation during missions in deep space can lead to bone marrow injury. The acute effects of proton irradiation on hematopoietic stem and progenitor cells remain undefined and thus were investigated. We exposed male C57BL/6 mice to 0.5 and 1.0 Gy proton total body irradiation (proton-TBI, 150 MeV) and examined changes in peripheral blood cells and bone marrow (BM) progenitors and LSK cells 2 weeks after exposure. 1.0 Gy proton-TBI significantly reduced the numbers of peripheral blood cells compared to 0.5 Gy proton-TBI and unirradiated animals, while the numbers of peripheral blood cell counts were comparable between 0.5 Gy proton-TBI and unirradiated mice. The frequencies and numbers of LSK cells and CMPs in BM of 0.5 and 1.0 Gy irradiated mice were decreased in comparison to those of normal controls. LSK cells and CMPs and their progeny exhibited a radiation-induced impairment in clonogenic function. Exposure to 1.0 Gy increased cellular apoptosis but not the production of reactive oxygen species (ROS) in CMPs two weeks after irradiation. LSK cells from irradiated mice exhibited an increase in ROS production and apoptosis. Exposure to proton-TBI can induce acute damage to BM progenitors and LSK cells.

  20. Relationship between the adaptive response and bystander effect produced by single cell irradiation using a focused ultrasoft x-ray microbeam

    International Nuclear Information System (INIS)

    Wu, L.; Schettino, G.; Folkard, M.; Yu, Z.; Prise, K.; Michael, B.; Wang, Y.

    2003-01-01

    Full text: Using the cell killing method and our newly developed focused carbon-K ultrasoft X-rays, we tested for an interaction between bystander responses and adaptive responses by irradiating only one V79 cell in a population with a dose of 0.2 or 1Gy, combined with a conventional 240kVp X irradiation (0, 0.01, 0.05, 0.2 or 1Gy) 2 hours before or after bystander treatment. The clonogenic survival of V79 cells was precisely measured by a single cell revisiting assay after incubation for 3 days. Our results clearly showed that the cell killing by the bystander treatment could be reduced by about 5% if we treated the cells with a very low dose of conventional 240kVp X-rays of 0.01 or 0.05Gy (at which dose they only kill 1 or 2% cells in a population), whether the conventional dose was given before or after bystander irradiation. When the conventional dose was increased to 0.2 or 1Gy (at which dose they could kill about 10 or 25% V79 cells), no adaptive response was found if we treated the cells with conventional irradiation first and bystander irradiation afterwards. However, the adaptive responses observed when we irradiated a single cell within the whole cell population before 0.2 or 1Gy conventional irradiation was given. This showed that the bystander-mediated adaptive response could increase the cell survival by 5 or 8% respectively compared with the cell killing by conventional irradiation of 0.2 or 1Gy only. We also tested the distribution of dead clones in the microbeam dishes either for bystander irradiation only or combined with conventional X-rays. We did not find any distance relationship between the irradiated cell and non-irradiated cells, which was consistent with our previous bystander irradiation studies showing an equal probability of finding damaged clones any where in the scanned area of the dish

  1. Epithelial cell kinetics in mouse and rat skin irradiated with electrons

    International Nuclear Information System (INIS)

    McMaster-Schuyler, L.

    1984-02-01

    Experiments were performed to examine the kinetic responses of mouse and rat epidermal cells in vivo after single doses of ionizing radiation including responses of hair follicles at times after irradiation. The labeling indices in both species were reduced to 30 to 50% of control values immediately following irradiation at all the doses. In the rat, the labeling indices recovered and overshot control values within the first three days after 300 to 1200 rads. The mouse labeling indices continued to be suppressed for up to 10 days after 300 to 2400 rads. This indicated that rat G 1 phase epidermal cells recovered three times faster than those of the mouse with respect to the ability to maintain or increase control level cell proliferation after irradiation. After 1800 and 2400 rads, doses which produce skin ulceration, both species showed a reduction in their labeling indices for up to 7 days, indicating that a dose-dependent mechanism of recovery may be operable in the rat. 99 refs., 15 figs., 6 tabs

  2. Ion, X-ray, UV and Neutron Microbeam Systems for Cell Irradiation.

    Science.gov (United States)

    Bigelow, A W; Randers-Pehrson, G; Garty, G; Geard, C R; Xu, Y; Harken, A D; Johnson, G W; Brenner, D J

    2010-08-08

    The array of microbeam cell-irradiation systems, available to users at the Radiological Research Accelerator Facility (RARAF), Center for Radiological Research, Columbia University, is expanding. The HVE 5MV Singletron particle accelerator at the facility provides particles to two focused ion microbeam lines: the sub-micron microbeam II and the permanent magnetic microbeam (PMM). Both the electrostatic quadrupole lenses on the microbeam II system and the magnetic quadrupole lenses on the PMM system are arranged as compound lenses consisting of two quadrupole triplets with "Russian" symmetry. Also, the RARAF accelerator is a source for a proton-induced x-ray microbeam (undergoing testing) and is projected to supply protons to a neutron microbeam based on the (7)Li(p, n)(7)Be nuclear reaction (under development). Leveraging from the multiphoton microscope technology integrated within the microbeam II endstation, a UV microspot irradiator - based on multiphoton excitation - is available for facility users. Highlights from radiation-biology demonstrations on single living mammalian cells are included in this review of microbeam systems for cell irradiation at RARAF.

  3. Cell proliferation and death in the irradiated pituitary gland and its modification by growth stimulants

    International Nuclear Information System (INIS)

    Guo Yaping; Hendry, Jolyon H.; Morris, Ian D.; Davis, Julian R.E.; Beardwell, Colin G.

    1997-01-01

    Purpose: This study was undertaken to show whether the rate of expression of radiation injury in the rat pituitary gland could be accelerated by the use of growth stimulants. Methods and Materials: Rat pituitary glands were irradiated in situ with a range of single doses up to 20 Gy. The rats were then given subcutaneous slow-release implants containing 17β-estradiol (E 2 ) and sulpiride (S) to stimulate lactotroph proliferation. Two sequential cycles were used, each consisting of stimulation (3 weeks) and withdrawal (2 weeks). Measurements were made of gland weight; BrdU-labeled, giant, and apoptotic cells; lactotrophs; as well as pituitary prolactin content, in response to exogenous thyroid-releasing hormone (TRH). Results: The two cycles of stimulation/withdrawal resulted in marked changes in gland weight, BrdU-labeling index, and serum prolactin (PRL) levels in unirradiated rats. The proportion of immunopositive growth-hormone-producing (GH) cells increased after irradiation. Radiation inhibited the hypertrophic response to E 2 + S and also inhibited increases in BrdU-labeling index and serum PRL levels. Also, giant lactotrophs were observed in the irradiated pituitaries. However, they were not seen in the unirradiated rats or in the irradiated rats treated with E 2 + S. TRH promoted PRL secretion in the unirradiated rat. In contrast, TRH inhibited PRL secretion in the irradiated rat and in all treatment groups receiving E 2 + S. Apoptosis was induced by irradiation and was substantially increased in lactotrophs and in other cell types by withdrawal of the E 2 and S stimulus, although the highest observed incidence was only 7 per 10,000 cells. Conclusion: Both irradiation and E 2 + S treatment removed the hypothalamic control of PRL secretion, which reveals this important inhibitory action of TRH upon PRL secretion. This suggests that it is not suitable as a dynamic test of pituitary PRL reserves in such abnormal situations, where there may also be damage to

  4. Systemic LPS Translocation Activates Cross-Presenting Dendritic Cells but Is Dispensable for the Breakdown of CD8+ T Cell Peripheral Tolerance in Irradiated Mice.

    Directory of Open Access Journals (Sweden)

    Gabriel Espinosa-Carrasco

    Full Text Available Lymphodepletion is currently used to enhance the efficacy of cytotoxic T lymphocyte adoptive transfer immunotherapy against cancer. This beneficial effect of conditioning regimens is due, at least in part, to promoting the breakdown of peripheral CD8+ T cell tolerance. Lymphodepletion by total body irradiation induces systemic translocation of commensal bacteria LPS from the gastrointestinal tract. Since LPS is a potent activator of the innate immune system, including antigen presenting dendritic cells, we hypothesized that LPS translocation could be required for the breakdown of peripheral tolerance observed in irradiated mice. To address this issue, we have treated irradiated mice with antibiotics in order to prevent LPS translocation and utilized them in T cell adoptive transfer experiments. Surprisingly, we found that despite of completely blocking LPS translocation into the bloodstream, antibiotic treatment did not prevent the breakdown of peripheral tolerance. Although irradiation induced the activation of cross-presenting CD8+ dendritic cells in the lymphoid tissue, LPS could not solely account for this effect. Activation of dendritic cells by mechanisms other than LPS translocation is sufficient to promote the differentiation of potentially autoreactive CD8+ T cells into effectors in irradiated mice. Our data indicate that LPS translocation is dispensable for the breakdown of CD8+ T cell tolerance in irradiated mice.

  5. Transplantability of human lymphoid cell line, lymphoma, and leukemia in splenectomized and/or irradiated nude mice

    International Nuclear Information System (INIS)

    Watanabe, S.; Shimosato, Y.; Kuroki, M.; Sato, Y.; Nakajima, T.

    1980-01-01

    The effects of splenectomy and/or whole-body irradiation of nude mice before xenotransplantation of lymphoid cell lines, lymphoma, and leukemia were studied. Transplantation after whole-body irradiation resulted in the increased ''take'' rate of three cultured cell lines (two of T-cell-derived acute lymphocytic leukemia and one of B-cell derived acute lymphocytic leukemia) and in the tumorous growth of Burkitt-derived Raji and spontaneously transformed lymphoblastoid cell lines. With splenectomy plus irradiation as a pretreatment, tumorous growth occurred in four other cell lines which were not transplantable after irradiation only (two cell lines of Epstein-Barr virus-transformed cord blood cells and one each of null acute lymphocytic leukemia and nodular lymphoma-derived cell lines). Direct transplantation of leukemia and lymphoma cells into the pretreated mice was successful in 7 of 24 cases (29%). B-cell-derived diffuse large lymphoid lymphoma was transplantable in three of seven cases (43%). However, lymphoma and leukemia of peripheral T-cell origin was difficult to transplant even with pretreatment, and only one pleomorphic T-cell lymphoma grew to a significant size (2 cm). One tumor each of B-cell-derived diffuse large lymphoid and T-cell diffuse lymphoblastic lymphoma became transplantable

  6. Down-regulation of SMT3A gene expression in association with DNA synthesis induction after X-ray irradiation in nevoid basal cell carcinoma syndrome (NBCCS) cells

    International Nuclear Information System (INIS)

    Sugaya, Shigeru; Nakanishi, Hiroshi; Tanzawa, Hideki; Sugita, Katsuo; Kita, Kazuko; Suzuki, Nobuo

    2005-01-01

    Fibroblast cells derived from nevoid basal carcinoma syndrome (NBCCS) patients show increased levels of DNA synthesis after X-ray irradiation. Genes, whose expression is modulated in association with the DNA synthesis induction, were searched by using PCR-based mRNA differential display analysis in one of the NBCCS cell lines, NBCCS1 cells. Decreased levels of SMT3A gene expression were found in X-ray-irradiated NBCCS1 cells. This decrease was also shown by RT-PCR analysis in another cell line, NBCCS3 cells. In addition to NBCCS cells, normal fibroblast cells showed the DNA synthesis induction after X-ray irradiation when they were treated with antisense oligonucleotides (AO) for SMT3A. However, treatment of normal fibroblasts with the random oligonucleotides (RO) resulted in decreased levels of DNA synthesis after X-ray irradiation. Thus, down-regulation of SMT3A gene expression may be involved in the DNA synthesis induction after X-ray irradiation in the NBCCS cells at least tested

  7. Down-regulation of SMT3A gene expression in association with DNA synthesis induction after X-ray irradiation in nevoid basal cell carcinoma syndrome (NBCCS) cells

    Energy Technology Data Exchange (ETDEWEB)

    Sugaya, Shigeru [Department of Environmental Biochemistry, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670 (Japan); Nakanishi, Hiroshi [Department of Clinical Molecular Biology, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670 (Japan); Tanzawa, Hideki [Department of Clinical Molecular Biology, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670 (Japan); Sugita, Katsuo [Department of Clinical Medicine, Faculty of Education, Chiba University, 1-33 Yayoi, Inage-ku, Chiba 263-8522 (Japan); Kita, Kazuko [Department of Environmental Biochemistry, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670 (Japan); Suzuki, Nobuo [Department of Environmental Biochemistry, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670 (Japan)]. E-mail: nobuo@faculty.chiba-u.jp

    2005-10-15

    Fibroblast cells derived from nevoid basal carcinoma syndrome (NBCCS) patients show increased levels of DNA synthesis after X-ray irradiation. Genes, whose expression is modulated in association with the DNA synthesis induction, were searched by using PCR-based mRNA differential display analysis in one of the NBCCS cell lines, NBCCS1 cells. Decreased levels of SMT3A gene expression were found in X-ray-irradiated NBCCS1 cells. This decrease was also shown by RT-PCR analysis in another cell line, NBCCS3 cells. In addition to NBCCS cells, normal fibroblast cells showed the DNA synthesis induction after X-ray irradiation when they were treated with antisense oligonucleotides (AO) for SMT3A. However, treatment of normal fibroblasts with the random oligonucleotides (RO) resulted in decreased levels of DNA synthesis after X-ray irradiation. Thus, down-regulation of SMT3A gene expression may be involved in the DNA synthesis induction after X-ray irradiation in the NBCCS cells at least tested.

  8. In vitro study on the effects of irradiation on synchronized tumour cells

    International Nuclear Information System (INIS)

    Reckewell, O.

    1987-01-01

    It was the aim of the study described here to ascertain and compare the individual effects of irradiation on synchronized cells originating from Yoshida's ascites sarcoma or Ehrlich's ascites carcinoma. The methods used for this purpose included growth tests just as well as impulse-cytophotometric and microscopic analyses. In Ehrlich's ascites carcinoma, cell division delays were seen to be slightly more pronounced for the G 2 phase, which was the one subjected to irradiation. The reaction pattern of Yoshida's sarcoma was characterised not only by markedly increased radiosensitivity of the G 1 phase but also by 'G 1 arrest' or suspended G 1 proliferation as a result of irradiation during any other phase of the cell cycle. The available evidence strongly suggests that the G 2 phase can certainly not be regarded as one generally showing increased sensitivity to rays. In view of the considerable variations between individual tumour strains it is also quite obvious that there can be no phase-dependent increases in radiosensitivity, which all cells have in common. (orig./MG) [de

  9. Cell Proliferation during Lymphopoiesis in the Thymus of Normal and Continuously Irradiated Mice

    Energy Technology Data Exchange (ETDEWEB)

    Fabrikant, J. I. [Department of Radiological Science, Johns Hopkins University, Baltimore, MD (United States)

    1968-08-15

    The patterns of lymphoid cell proliferation in the thymus and spleen in normal and continuously irradiated young C57BL mice have been examined with techniques of flash and repeated labelling with tritiated thymidine and high resolution autoradiography. Changes in percentage labelling indices and labelled mitoses data have provided information on sites and rates of lymphoid cell proliferation in the thymus cortex (reticular cells, large, medium and small lymphocytes) and the spleen white pulp (germinal centre cells, large, medium and small lymphocytes). Labelling rates were fastest in the more primitive cell forms; in both lymphoid organs, the stem-cell labelling - reticular cells and germinal centre cells - reached 100% rapidly, whereas this was not the case for the different lymphocyte populations, and thymic lymphopoiesis was more rapid than splenic lymphopoiesis. Mean cycle times for thymus lymphoid cells were {approx} 12.5 hours for reticular cells, {approx} 9.5 hours for large lymphocytes, and {approx} 10.0 hours for medium and small lymphocytes; in the spleen, representative cycle times were significantly longer. Small lymphocytes were replaced at a greater rate in the thymus than in the spleen. Under continuous {gamma}-irradiation (caesium-137) at 45 rad/day and 75 rad/day for 15 days, there was a progressive depopulation of all lymphoid cell classes, an increase in the relative proportion of the more primitive forms, and a marked decrease in the numbers of small lymphocytes in both tissues. In the thymus and in the spleen, there was an increase in proliferation rates in both stem-cell populations and in all lymphoid cell forms, a decrease in mean cell cycle times to shorter values and a possible reduction in the spread of cell cycle times. In irradiated tissues, there was little evidence for lymphoid cell emigration. Tentative patterns of lymphopoiesis in the normal thymus and spleen based on the autoradiographic data aredescribed and changes in the

  10. Development of a single ion micro-irradiation facility for experimental radiobiology at cell level

    International Nuclear Information System (INIS)

    Barberet, Ph.

    2003-10-01

    A micro-irradiation device has been developed for radiobiology applications at the scale of the cell. This device is based on an upgrade of an existing micro-beam line that was already able to deliver a 1 to 3 MeV proton or alpha beam of low intensity and whose space resolution is lower than 1 micrometer in vacuum. The important part of this work has been the development of an irradiation stage designed to fit on the micro-probe and able to deliver ions in the air with an absolute accuracy of a few micrometers. A program has been set up to monitor the complete irradiation line in testing and in automatic irradiation operating phases. Simulation tools based on Monte-Carlo calculations have been validated through comparisons with experimental data particularly in the field of spatial resolution and of the number of ions delivered. The promising results show the possibility in a near future to use this tool to study the response of cells to very low irradiation doses down to the extreme limit of one ion per cell