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Sample records for x-irradiated differentially radiosensitive

  1. Radiosensitivity of pulmonary alveolar macrophages in rats exposed to local X-irradiation

    International Nuclear Information System (INIS)

    Gong Yifen; Fei Lihua; Wu Dechang

    1987-01-01

    The radiosensitivity of pulmonary alveolar macrophages (PAMs) in rats exposed to local thoracic X-irradiatoin was studied. The percentages of mitotic and labeling cells were used as biological endpoints. The parameters of radiosensitivity of PAMs obtained on the second day after local exposure are as follows: D 0 = 0.68 Gy, Dq = 0.06 Gy, n = 1.1 for mitotic cells and D 0 = 1.04 Gy, Dq = 0.12 Gy, n = 1.12 for labeling cells. The parameters of radiosensitivity of PAMs in bronchical lavage obtained immediately after X-irradiation are: D 0 = 3.56 Gy, Dq = 0.77 Gy, n = 1.24 for labeling cells and D 0 = 3.69 Gy, Dq = 0.35 Gy, n = 1.1 for mitotic cells. The comparison of thses results indicates that the radiation effect on PAMs obtained immediately after X-irradiation is less severe than that of PAMs obtained 2 days later. It might be caused by the delay of cell cycle within 2 days after X-irradiation

  2. Thermo-radiosensitivity of the granulocyte and macrophage precursor cells of mice. II. - X irradiation effects and influence of hyperthermia on the radiosensitivity

    International Nuclear Information System (INIS)

    Bueren, J.A.; Nieto, M.

    1983-01-01

    The effects of the X-irradiation on the viability of the granulocyte-macrophage precursors, has been determined by means of the agar diffusion chamber culture technique. The results show the high radiosensitivity of these cells, with survival parameter similar to those previously reported in the literature about different granulocyte-macrophage precursors. When a hyperthermic treatment is performed prior to the X-irradiation, a radiosensitization phenomenon is observed due to the synergism existent between hyperthermia and X rays on the lethality of the precursors. (Authors) 37 refs

  3. Differential cisplatin responses in human carcinoma cell lines pre-exposed to fractionated X-irradiation

    International Nuclear Information System (INIS)

    Dempke, W.C.M.; Hosking, L.K.; Shellard, S.A.; Hill, B.T.

    1991-01-01

    These results suggest that cells exposed to X-irradiation may respond differently to subsequent cisplatin (CDDP) treatment. Initial studies of possible mechanisms responsible for these differential sensitivities indicate that they may differ according to whether resistance or hypersensitivity is expressed. (author)

  4. 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)

  5. 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.

  6. Thermo-radiosensitivity of the granulocyte and macrophage precursor cells of mice. I I . - X- irradiation effects and influence of hyperthermia on the radiosensitivity; Termo-radiosensibilidad del precursor hematopoyetico que origina las series granulocitica y macrofaga de raton. II. - Efectos producidos por la radiacion X e influencia de la hipertermia sobre la radiosensibilidad celular

    Energy Technology Data Exchange (ETDEWEB)

    Bueren, J A; Nieto, M

    1983-07-01

    The effects of the X-irradiation on the viability of the granulocyte-macrophage precursors, has been determined by means of the agar diffusion chamber culture technique. The results show the high radiosensitivity of these cells, with survival parameter similar to those previously reported in the literature about different granulocyte-macrophage precursors. When a hyperthermic treatment is performed prior to the X-irradiation, a radiosensitization phenomenon is observed due to the synergism existent between hyperthermia and X rays on the lethality of the precursors. (Authors) 37 refs.

  7. Differential Effects of Alpha-Particle Radiation and X-Irradiation on Genes Associated with Apoptosis

    International Nuclear Information System (INIS)

    Chauhan, V.; Howland, M.; Chen, J.; Kutzner, B.; Wilkins, R.C.

    2011-01-01

    This study examined differential effects of alpha-(α) particle radiation and X-rays on apoptosis and associated changes in gene expression. Human monocytic cells were exposed to a-particle radiation and X-rays from 0 to 1.5 Gy. Four days postexposure, cell death was measured by flow cytometry and 84 genes related to apoptosis were analyzed using real-time PCR. On average, 33% of the cells were apoptotic at 1.5 Gy of a-particle radiation. Transcript profiling showed statistical expression of 15 genes at all three doses tested. Cells exposed to X-rays were <5% apoptotic at ∼1.5 Gy and induced less than a 2-fold expression in 6 apoptotic genes at the higher doses of radiation. Among these 6 genes, Fas and TNF-α were common to the α-irradiated cells. This data suggests that α-particle radiation initiates cell death by TNF-a and Fas activation and through intermediate signalling mediators that are distinct from X-irradiated cells

  8. Proliferation and Differentiation of Autologic and Allogenic Stem Cells in Supralethally X-Irradiated Dogs

    Energy Technology Data Exchange (ETDEWEB)

    Chertkov, I. L. [Department of Radiobiology, Central Institute of Haematology and Blood Transfusion, Moscow, USSR (Russian Federation)

    1967-07-15

    Full text: Allogenic bone marrow after transplantation into dogs irradiated with 1000 R X-rays differentiates in the normal way only for 3-4 days, afterwards transforming into lymphoid cells. This transformation is due to the antigen stimulus of the host on the grafted stem cells. The lymphoid cells, obtained from the host's blood on the 7-8th day after grafting, showed specific, immune activity under the Immune Lymphocyte Transfer test. Within a short duration of the immune response immunoblasts and immunocytes Undergo degenerative changes: destroyed mitochondria, formation of autophagic vacuoles and, finally, lysis of the cells. These changes are suggested to be the result of overloading of immune cells with antigen. Preliminary sensitization of the donor with prospective host's haemopoietic tissue does not hasten the immune transformation of haemopoiesis. Injections of bacterial pyrogen, cortisone or 6-mercaptopurine into recipients, as well as incubation of bone marrow at 37 Degree-Sign C for 2 hours, do not prevent the immune transformation. Preliminary thymectomy of the prospective recipients prevents in some of the cases immune transformation of the bone-marrow graft. The delay of allogenic bone-marrow transplantation for 5-6 days prevents in some dogs (X-irradiated with 1000 R, but not with 1200 R) the immune transformation. Transplantation of autologic bone marrow or shielding of the legs during irradiation is accompanied with good restoration of normal haemopoiesis without lymphoid transformation. (author)

  9. Differential effects of fractionated X irradiation on mouse spermatogonial stem cells

    NARCIS (Netherlands)

    van der Meer, Y.; Huiskamp, R.; Davids, J. A.; de rooij, D. G.

    1993-01-01

    The response of spermatogonial stem cells to fractionated X irradiation was studied in the various stages of the spermatogenic cycle of the CBA mouse. Fractionated doses of 2 + 2, 1 + 3, and 3 + 1 Gy with a 24-h interval between the doses were compared with a single dose of 4 Gy. The numbers of

  10. Differential radiosensitivity among B cell subpopulations

    International Nuclear Information System (INIS)

    Riggs, J.E.

    1988-01-01

    The selective radiosensitivity of sIgM >> sIgD marginal zone B cells is associated with the selective loss of B cell function. The simultaneous restoration of impaired function and recovery of these cells with time supports this premise. B cell recovery, delayed one week after irradiation, is in progress at two weeks, and virtually complete by three weeks. XID mice reveal similar recovery kinetics although there are fewer recovering cells and these bear reduced levels of Ia. This observation represents additional evidence that xid B cells are distinct from those of normal mice. The simultaneous loss, and concurrent recovery, of sIgM >> sIgD B cells and TI-2 responsiveness in irradiated mice suggests the existence of a unique B cell subpopulation possessing both phenotypes. Additional support for this hypothesis is provided by demonstrating that splenocytes, depleted of IgD + cells adoptively reconstitute this response in XID mice. The peritoneal B cell pool, which, compared to the spleen, consist of increased numbers of sIgM >> sIgD B cells, is shown to be a source of radiosensitive B cells that are TI-2 responsive. These observations represent additional evidence for an association between sIgM >> sIgD B cells and TI-2 responsiveness

  11. Ascertainment of the effect of differential growth rates of mutants on observed mutant frequencies in X-irradiated mammalian cells

    International Nuclear Information System (INIS)

    Knaap, A.G.A.C.; Simons, J.W.I.M.

    1983-01-01

    As it is not known to what extent differential growth rates of induced mutants lead to over- and under-representation of mutants in treated populations and thereby affect the determination of mutant frequencies, the mutation induction in X-irradiated L5178Y mouse lymphoma cells was determined via two methods. The first method involves the standard protocol which may suffer from the effect of differential growth rates, while the second method is based upon the fluctuation test in which the differential growth rates can be actually measured. It appeared that the standard protocol led to a mutant frequency that was similar to the mutant frequency determined in the fluctuation test. Therefore, the standard protocol appears to lead to only a minor under-estimation if any. Substantial heterogeneity in growth rates of induced mutants was observed, but the mutants with a selective advantage appear largely to compensate for the mutants that are lost because of selective disadvantage. It was calculated that the chance for isolating the same mutant twice from a treated population had been increased 2.2-fold because of the observed differential growth rates. (orig./AJ)

  12. Differential radiosensitivity on a tissue level in Delphinium ajacis

    Energy Technology Data Exchange (ETDEWEB)

    Mandal, S K; Basu, R K [Bose Research Inst., Calcutta (India). Cryogenetics Lab.

    1980-09-01

    Root, leaf, pollen mother cell and endosperm of D.ajacis showed differential sensitivity as measured by X-ray-induced chromosomal aberrations at mitotic anaphase and telophase stages of the first and second division cycles after irradiation. These tissues differed significantly in Interphase Chromosome Volume (ICV) values. In all the tissues the percentage of aberrant cells increased linearly with increase in X-ray dose. Though endosperm had the largest ICV value it was the most radioresistant tissue tested. The relative radiosensitivity of the other 3 tissues was positively correlated with ICV value. The radioresistance of endosperm is probably due to factors unique to this tissue which remained obscure.

  13. Differential Radiosensitizing Effect of Valproic Acid in Differentiation Versus Self-Renewal Promoting Culture Conditions

    International Nuclear Information System (INIS)

    Debeb, Bisrat G.; Xu Wei; Mok, Henry; Li Li; Robertson, Fredika; Ueno, Naoto T.; Reuben, Jim; Lucci, Anthony; Cristofanilli, Massimo; Woodward, Wendy A.

    2010-01-01

    Purpose: It has been shown that valproic acid (VA) enhances the proliferation and self-renewal of normal hematopoietic stem cells and that breast cancer stem/progenitor cells can be resistant to radiation. From these data, we hypothesized that VA would fail to radiosensitize breast cancer stem/progenitor cells grown to three-dimensional (3D) mammospheres. Methods and Materials: We used the MCF7 breast cancer cell line grown under stem cell-promoting culture conditions (3D mammosphere) and standard nonstem cell monolayer culture conditions (two-dimensional) to examine the effect of pretreatment with VA on radiation sensitivity in clonogenic survival assays and on the expression of embryonic stem cell transcription factors. Results: 3D-cultured MCF-7 cells expressed higher levels of Oct4, Nanog, and Sox2. The 3D passage enriched self-renewal and increased radioresistance in the 3D mammosphere formation assays. VA radiosensitized adherent cells but radioprotected 3D cells in single-fraction clonogenic assays. Moreover, fractionated radiation sensitized VA-treated adherent MCF7 cells but did not have a significant effect on VA-treated single cells grown to mammospheres. Conclusion: We have concluded that VA might preferentially radiosensitize differentiated cells compared with those expressing stem cell surrogates and that stem cell-promoting culture is a useful tool for in vitro evaluation of novel cancer therapeutic agents and radiosensitizers.

  14. X irradiation of human epidermis in vitro. 2

    International Nuclear Information System (INIS)

    Wollina, U.; Fueller, J.; Burger, B.; Hipler, C.; Jena Univ.

    1989-01-01

    On the example of the reduction of epidermal adhesion of FITC wheat germ agglutinine (WGA) the direct membrane effect of a single X irradiation (44 kV and 220 kV) was analyzed in vitro. Human normal skin and psoriasis centres were compared. Normal skin showed no alteration of microscopically visible FITC-WGA adhesion on epidermal cells over the whole dose range. Foci of psoriasis responded to doses of ≥ 5 Gy (44 and 220 kV) with a drastic reduction of epidermal lectin binding to lower and medium cell layers. Maximum efficacy was with 5 Gy (44 kV) or 10 Gy (220 kV). A dose elevation up to 20 Gy did not result in an increase of efficacy. Topographically the radiosensitive FITC-WGA adhesion could chiefly be seen in the dermal ridges. The findings support the impression of an increased radiosensitivity of the lesional psoriatic epidermis compared with normal skin. This is connected with an abnormal differentiation of keratinocytes in psoriasis. (author)

  15. Induction of DNA-strand breaks after X- irradiation in murine bone cells of various differentiation capacities

    Science.gov (United States)

    Lau, P.; Hellweg, C. E.; Kirchner, S.; Arenz, A.; Baumstark-Khan, C.; Horneck, G.

    Bone loss resulting from long-duration space flight is a well known medical risk for space travellers, as a weakened skeleton is more susceptible to bone fractures. In addition to weightlessness the astronaut is also exposed to cosmic ionizing radiation. In order to elucidate changes in bone cell metabolism by ionizing radiation, a ground-based bone cell model has been developed. This model consists of a bunch of immortalized murine osteocyte, osteoblast and pre-osteoblast cell lines representing discrete stages of differentiation: The osteocyte cell line MLO-Y4 (obtained from L. Bonewald, Kansas City, USA), the osteoblast cell line OCT-1 (obtained from D. Chen, San Antonio, USA), and the subclones 4 and 24 of the osteoblast cell line MC3T3-E1 (obtained from ATCC, Manassas, Virginia, USA). Regarding their growth properties, MLO-Y4 cells show the highest growth velocity with a doubling time of 15.8 h. The osteoblast cell line OCT-1 has a doubling time of 27.3 h. The respective values for MC3T3-E1 subclone 24 and S4 are 90.5 h and 51.6 h. To investigate the stage of differentiation, the expression of alkaline phosphatase, of osteocalcin and of E11 was examined. Survival after X-ray exposure was determined using the colony forming ability test. The resulting dose-effect relationships revealed significant differences. The parameter D0 of the survival curves ranges between 1.8 Gy for OCT-1, 1.9 Gy for MLO-Y4, 2.0 Gy for subclone 24 and 2,3 Gy for subclone 4. The quantitative acquisition of DNA-strand breaks was performed by Fluorescent Analysis of DNA-Unwinding (FADU). The results can be correlated with the corresponding survival curve. In conclusion, the cell lines with higher differentiation levels are less sensitive to radiation when compared to the lower differentiated osteoblast cell lines.

  16. Differential response of inbred and F1 hybrid embryos of Hibiscus sabdariffa L. to x-irradiation

    International Nuclear Information System (INIS)

    Shome, A.; Hazra, S.

    1988-01-01

    Radio-response of HS 4288, HS 7910 and two F 1 hybrid embryos of H. sabdariffa to X-ray doses (2-8 kR) was assessed. Reduction in shoot and root length and incidence of root injuries increased always with the increase of X-ray doses. LD 50 values of HS 4288, HS 7910, F 1 HS 4288 x HS 7910 and F 1 HS 7910 x HS 428 were in between 5 and 6 kR, 2 and 4 kR, 6 and 8 kR, and 5 and 6 kR respectively. Judging by LD 50 values and 100 per cent seedling abnormality, relatively HS 4288 and F 1 HS 4288 x HS 7910 were resistant and HS 7910 and F 1 HS 7910 x HS 4288 were susceptible. Induction of macro-mutations was different in two inbreds and also in two F 1 hybrids. Role of cytoplasmic factors for the differential response are discussed. (author). 14 refs., 5 tabs

  17. 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

  18. The proliferative activity of testicular cell types and the effect of postnatal X-irradiation in the developing mouse testis

    International Nuclear Information System (INIS)

    Vergouwen, R.P.F.A.; Huiskamp, R.; Davids, J.A.G.; Rooij, D.G. de

    1991-01-01

    The authors describe the effects of x-irradiation on the developing mouse testis, particularly in relation to A spermatogonia, Sertoli cells, Leydig cells and mesenchymal cells commonly regarded as Leydig precursors. It was concluded that radiosensitivity is highest during the first week after birth and decreases thereafter, with the exception of A spermatogonia which are radiosensitive at all ages. (UK)

  19. X irradiation of human epidermis in vitro. 2. Comparison of single 44 kV and 200 kV X irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Wollina, U; Fueller, J; Burger, B; Hipler, C

    1989-01-01

    On the example of the reduction of epidermal adhesion of FITC wheat germ agglutinine (WGA) the direct membrane effect of a single X irradiation (44 kV and 220 kV) was analyzed in vitro. Human normal skin and psoriasis centres were compared. Normal skin showed no alteration of microscopically visible FITC-WGA adhesion on epidermal cells over the whole dose range. Foci of psoriasis responded to doses of /ge/ 5 Gy (44 and 220 kV) with a drastic reduction of epidermal lectin binding to lower and medium cell layers. Maximum efficacy was with 5 Gy (44 kV) or 10 Gy (220 kV). A dose elevation up to 20 Gy did not result in an increase of efficacy. Topographically the radiosensitive FITC-WGA adhesion could chiefly be seen in the dermal ridges. The findings support the impression of an increased radiosensitivity of the lesional psoriatic epidermis compared with normal skin. This is connected with an abnormal differentiation of keratinocytes in psoriasis. (author).

  20. Radiosensitivities of sensitized lymphocytes

    International Nuclear Information System (INIS)

    Taniguchi, Kazuto

    1979-01-01

    Immunization of mice with cell antigens such as allogeneic tumor cells or xenogeneic erythrocytes raises a variety of immune reactions mediated by T lymphocytes: i.e. delayed type hypersensitivity (DTH), cytotoxicity, and antibody production. The radiosensitivities of these reactions were examined in mice exposed to 600 R x-irradiation a few hours before or after immunization. 1) DTH to xenogeneic erythrocytes, as demonstrated by footpad reaction, was not suppressed by irradiation 3 h before or after immunization. DTH to allogeneic tumor cells, as demonstrated by a migration inhibition test, hardly developed in mice that had been irradiated before or after immunization. It may have belonged to distinct types of delayed reactions which were mediated by distinct subpopulations of T lymphocytes. 2) Cytotoxicity against allogeneic cells and xenogeneic erythrocytes showed almost the same radiosensitivity. It was scarcely detected in mice that had been irradiated before immunization. However, a low but definite degree of cytotoxicity was detected in mice that had been irradiated only a few hours after immunization. Solubilized allogeneic cells instead of native cells were used as immunizing antigens. It was also possible for precursor cells with cytotoxicity to acquire a radioresistant nature by immunization of solubilized antigens, but native cells were required as stimulation for radioresistant precursor cells to differentiated into nature cytotoxic effector cells. 3) Antibody production against xenogeneic erythrocytes or allogeneic cells was almost completely depleted in mice that had been irradiated before or after immunization. It is possible that antibody production essentially requires cell division and clonal expansion of B lymphocytes. (Bell, E.)

  1. 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.

  2. Regulation of antibody synthesis in the X-irradiated Mexican axolotl

    International Nuclear Information System (INIS)

    Charlemagne, J.

    1981-01-01

    The effects of X-irradiation were studied on the Mexican axolotl antibody synthesis. To reduce the anti-horse red blood cell (HRBC) antibody titers, 150 rd and smaller doses are ineffective, 200-450 rd are increasingly effective, and 700 rd are maximally effective (and lethal). A significant enhancement of the anti-HRBC titers was observed in low doses (50-150 rd X-irradiated animals). This enhancement was also observed when a low X-ray dose was applied only on the thymic areas. In whole body, but thymus area-shielded, 100 rd X-irradiated animals, the anti-HRBC titers were similar to those of the nonirradiated, HRBC-immunized control group. To explain these phenomena, it is suggested that a radiosensitive, adult thymectomy-sensitive and hydrocortisone-sensitive suppressor T cell subpopulation regulates the antibody synthesis in the axolotl. (orig.) [de

  3. Regulation of antibody synthesis in the X-irradiated Mexican axolotl

    Energy Technology Data Exchange (ETDEWEB)

    Charlemagne, J.

    1981-09-01

    The effects of X-irradiation were studied on the Mexican axolotl antibody synthesis. To reduce the anti-horse red blood cell (HRBC) antibody titers, 150 rd and smaller doses are ineffective, 200-450 rd are increasingly effective, and 700 rd are maximally effective (and lethal). A significant enhancement of the anti-HRBC titers was observed in low doses (50-150 rd X-irradiated animals). This enhancement was also observed when a low X-ray dose was applied only on the thymic areas. In whole body, but thymus area-shielded, 100 rd X-irradiated animals, the anti-HRBC titers were similar to those of the nonirradiated, HRBC-immunized control group. To explain these phenomena, it is suggested that a radiosensitive, adult thymectomy-sensitive and hydrocortisone-sensitive suppressor T cell subpopulation regulates the antibody synthesis in the axolotl.

  4. Contributions concerning radiosensitivity proffered by the basic sciences to clinical radiation therapy

    International Nuclear Information System (INIS)

    Caputo, A.

    1974-01-01

    Basic concepts of radiosensitivity are reviewed. Some topics discussed are: probability of lethal injury as a dose dependent function; mutations resulting from radiation damage to DNA; relation of cell radiosensitivity to chromosome volume; relation of molecular structure of DNA to relative radiosensitivity of the organism; repair replication of DNA following uv and x irradiation of Escherichia coli and mammalian cells; and relation of the cell cycle to radiosensitivity. (U.S.)

  5. Differential Radiosensitizing Potential of Temozolomide in MGMT Promoter Methylated Glioblastoma Multiforme Cell Lines

    International Nuclear Information System (INIS)

    Nifterik, Krista A. van; Berg, Jaap van den; Stalpers, Lukas J.A.; Lafleur, M. Vincent M.; Leenstra, Sieger; Slotman, Ben J.; Hulsebos, Theo J.M.; Sminia, Peter

    2007-01-01

    Purpose: To investigate the radiosensitizing potential of temozolomide (TMZ) for human glioblastoma multiforme (GBM) cell lines using single-dose and fractionated γ-irradiation. Methods and Materials: Three genetically characterized human GBM cell lines (AMC-3046, VU-109, and VU-122) were exposed to various single (0-6 Gy) and daily fractionated doses (2 Gy per fraction) of γ-irradiation. Repeated TMZ doses were given before and concurrent with irradiation treatment. Immediately plated clonogenic cell-survival curves were determined for both the single-dose and the fractionated irradiation experiments. To establish the net effect of clonogenic cell survival and cell proliferation, growth curves were determined, expressed as the number of surviving cells. Results: All three cell lines showed MGMT promoter methylation, lacked MGMT protein expression, and were sensitive to TMZ. The isotoxic TMZ concentrations used were in a clinically feasible range of 10 μmol/L (AMC-3046), 3 μmol/L (VU-109), and 2.5 μmol/L (VU-122). Temozolomide was able to radiosensitize two cell lines (AMC 3046 and VU-122) using single-dose irradiation. A reduction in the number of surviving cells after treatment with the combination of TMZ and fractionated irradiation was seen in all three cell lines, but only AMC 3046 showed a radiosensitizing effect. Conclusions: This study on TMZ-sensitive GBM cell lines shows that TMZ can act as a radiosensitizer and is at least additive to γ-irradiation. Enhancement of the radiation response by TMZ seems to be independent of the epigenetically silenced MGMT gene

  6. Differential radiosensitivity of seeds, seedlings and callus cultures of Petunia inflata

    International Nuclear Information System (INIS)

    Bapat, V.A.; Rao, P.S.

    1976-01-01

    A comparative study of the effects of γ-irradiation on seeds, seedlings and callus cultures of Petunia inflata showed striking differences in radiosensitivity as reflected in differences in mean fresh and dry weights, seedling height and morphology. Seeds subjected to low doses (4-6 kR) of irradiation showed stimulation of seedling height. Direct exposure of seedlings to high doses (10 kR) of irradiation caused inhibition in their development. Callus cultures, however, were more radioresistant compared to seeds and seedlings. Tissues grown on either an irradiated nutrient medium or on a medium in which sucrose alone had been irradiated, showed a marked inhibition in their growth potential

  7. Growth regulation in X-irradiated mouse skin

    International Nuclear Information System (INIS)

    Elgjo, K.; Devik, F.

    1978-01-01

    Extracts of hairless mouse skin were tested for their content of epidermal G 1 inhibitor and G 2 inhibitor at daily intervals after X-irradiation with 4 500 or 2 250 rad. After either dose the skin extracts lacked G 1 inhibitory activity on days 5 and 6 respectively after irradiation. This coincided with the time when the epidermal mitotic rate again became normal and started a period of over-shoot. The time interval of 5 to 6 days corresponds to the turnover time of the differentiating cells in hairless mouse back epidermis. The findings indicate that the proliferating cells in epidermis can respond to changes in local chalone concentration, even after X-irradiation at the tested doses, and that the irradiated epidermal cell population still retains some important properties inherent in a cybernetically regulated system. The local G 2 -inhibitory activity also varied after irradiation, but these variations could not be directly related to the corresponding mitotic rates. (author)

  8. Effect of X-irradiation on fecundity, fertility and longevity of the red cotton bug Dysdercus koenigii Fabr

    International Nuclear Information System (INIS)

    Srivastava, K.P.; Deshpande, D.J.

    1983-01-01

    X-irradiation of the sexes affects reproduction in D. koenigii differently. Irradiation of the male has no effect on the fecundity of the female but that of the female affects it adversely. Fertility shows fluctuations at lower doses and a linear decline at higher ones irrespective of the sex irradiated. But whereas complete sterility (infertility) sets in the female at 2000 rad, the male needs 4000 rad to induce the same in the female, which indicates a greater radiosensitivity of the former, longevity is unaffected by X-irradiation, indicating lack of correlation between sterility and longevity reported to exist in some insects. (author)

  9. Contribution of caspase-3 differs by p53 status in apoptosis induced by X-irradiation

    International Nuclear Information System (INIS)

    Kobayashi, Daisuke; Tokino, Takashi; Watanabe, Naoki

    2001-01-01

    We investigated the effect of p53 status on involvement of caspase-3 activation in cell death induced by X-irradiation, using rat embryonic fibroblasts (REFs) transduced with a temperature-sensitive mutant (mt) p53 gene. Cells with wild-type (wt) p53 showed greater resistance to X-irradiation than cells with mt p53. In cells with wt p53, X-irradiation-induced apoptosis was not inhibited by the caspase-3 inhibitor acetyl-L-aspartyl-L-methionyl-L-glutaminyl-L-aspartyl-aldehyde (Ac-DMQD-CHO) and caspase-3 activity was not elevated following X-irradiation, although induction of p53 and p21/WAF-1 protein was observed. In contrast, irradiated cells with mt p53 showed 89% inhibition of cell death with Ac-DMQD-CHO and 98% inhibition with the antioxidant N-acetyl-L-cysteine (NAC). In cells with mt p53, caspase-3 activity was increased approximately 5 times beyond baseline activity at 24 h after irradiation. This increase was almost completely inhibited by NAC. However, inhibition of caspase-3 by Ac-DMQD-CHO failed to decrease production of reactive oxygen species by cells with mt p53. Differential involvement of caspase-3 is a reason for differences in sensitivity to X-irradiation in cells with different p53 status. Caspase-3 activation appears to occur downstream from generation of reactive oxygen species occurring independently of wt p53 during X-irradiation-induced cell death. (author)

  10. Is variation in human radiosensitivity real or artifactual?

    International Nuclear Information System (INIS)

    Nakamura, Nori; Kushiro, Jun-ichi; Sposto, R.; Akiyama, Mitoshi.

    1989-12-01

    Two methods of producing human T-lymphocyte colonies in vitro are described, as well as dose-survival experiments using these methods for the investigation of possible differential radiosensitivity among individuals. In one method, the cloning efficiency (CE) of nonirradiated lymphocytes was between 10 % and 40 % (method 1), whereas subsequent improvement in assay conditions (method 2) resulted in a CE greater than 30 %. In vitro X-irradiation of colonies produced using method 1 revealed that the dose required to kill 90 % of the cells (D 10 ) was 2.87±0.28 Gy (mean ±SD, n = 18) for repeated examinations of lymphocytes from one reference individual. Using method 2, the D 10 values were greater, viz., 3.66±0.21 Gy for 28 repeated tests of the same reference individual and 3.58±0.19 Gy for 31 different individuals. Analysis of variance to compare the data from repeated examinations of one person versus data from single examinations of different persons showed that variation in the D 10 value was not significantly greater in the latter group. These results support the hypothesis that individual variation in human radiosensitivity is quite small, if it exists at all, as far as can be determined by the loss of colony-forming ability of irradiated G 0 lymphocytes. (author)

  11. Differential sensitivity of cellular membranes to peroxidative processes. An electronmicroscopic, histochemical and cytochemical study of the effects of vitamin E deficiency and X-irradiation on the liver of the Pekin duckling

    Energy Technology Data Exchange (ETDEWEB)

    Huijbers, W A.R.

    1976-01-01

    A description is given of a morphological and cytochemical investigation into the effects of both vitamin E deficiency and x irradiation on the ultrastructure and enzyme activities of several cellular membranes, particularly the plasma membrane and the membranes of lysosomes, mitochondria and endoplasmic reticulum. In the vitamin E deficient situation, the radicals and peroxides only originate near mitochondria and endoplasmic reticulum, so that these membrane systems suffer from changes. After irradiation of the liver of both the control duckling and the deficient duckling, radicals originate in all parts of the cell. Due to their high content of lipids and cholesterols, peroxides will occur mainly in plasma membranes and lysosomal membranes. Moreover, in these membranes there is hardly any protection by vitamin E.

  12. Differential response of DU145 and PC3 prostate cancer cells to ionizing radiation: role of reactive oxygen species, GSH and Nrf2 in radiosensitivity.

    Science.gov (United States)

    Jayakumar, Sundarraj; Kunwar, Amit; Sandur, Santosh K; Pandey, Badri N; Chaubey, Ramesh C

    2014-01-01

    Radioresistance is the major impediment in radiotherapy of many cancers including prostate cancer, necessitating the need to understand the factors contributing to radioresistance in tumor cells. In the present study, the role of cellular redox and redox sensitive transcription factor, Nrf2 in the radiosensitivity of prostate cancer cell lines PC3 and DU145, has been investigated. Differential radiosensitivity of PC3 and DU145 cells was assessed using clonogenic assay, flow cytometry, and comet assay. Their redox status was measured using DCFDA and DHR probes. Expression of Nrf2 and its dependent genes was measured by EMSA and real time PCR. Knockdown studies were done using shRNA transfection. PC3 and DU145 cells differed significantly in their radiosensitivity as observed by clonogenic survival, apoptosis and neutral comet assays. Both basal and inducible levels of ROS were higher in PC3 cells than that of DU145 cells. DU145 cells showed higher level of basal GSH content and GSH/GSSG ratio than that of PC3 cells. Further, significant increase in both basal and induced levels of Nrf2 and its dependent genes was observed in DU145 cells. Knock-down experiments and pharmacological intervention studies revealed the involvement of Nrf2 in differential radio-resistance of these cells. Cellular redox status and Nrf2 levels play a causal role in radio-resistance of prostate cancer cells. The pivotal role Nrf2 has been shown in the radioresistance of tumor cells and this study will further help in exploiting this factor in radiosensitization of other tumor cell types. © 2013.

  13. Post-X-irradiation effects on petunia pollen germinating in vitro and in vivo

    International Nuclear Information System (INIS)

    Gilissen, L.J.W.

    1978-01-01

    The germination of Petunia hybrida L. pollen grains in germination medium, containing 10% sucrose and 0.01 % H 3 BO 3 , was linearly related to relative humidity (RH): being minimal at 0 % RH and maximal at 100 % RH. The low germination at 0 % RH was completely restored after transfer to 100 % RH. Germination in medium decreased with increasing X-ray exposures between O and 400 kR. This decrease was caused by pollen rupture. No in vitro germination occurred at exposures of 400 kR and more. The radiosensitivity of pollen in vitro was minimal at 80 % RH. Transfer of pollen to the stigma post-X-irradiation resulted in resistance to much higher exposures of irradiation (<750 kR). The differences in radiosensitivity of the pollen germinated in vitro and in vivo are due possibly to the differences in composition of the germination medium and the stigmatic exudate. Pollen tube growth of irradiated pollen after compatible or incompatible pollination at first showed retarded then normal tube growth. A conclusion is that X-irradiation of pollen cannot influence the characteristics of pollen tube growth after compatible or incompatible pollination. (author)

  14. Differential radiosensitivity of mouse embryonic neurons and glia in cell culture

    International Nuclear Information System (INIS)

    Dambergs, R.; Kidson, C.

    1977-01-01

    The responses of neurons and glial cells to ultraviolet and γ-radiation were studied in cell cultures of embryonic mouse brains. A decrease in the ratio of glia to neurons occurred after both forms of irradiation. [ 3 H]thymidine labelling followed by autoradiography revealed that all glia were capable of replication, whereas 70 percent of neurons were non-replicating under the conditions of the study. Ultraviolet radiation caused a decrease in the proportion of replicating neurons but did not affect the proportion of replicating glia, whereas γ-radiation caused a decrease in DNA replication in both cell types. Levels of ultraviolet radiation-induced unscheduled DNA synthesis were lower in neurons than in glia. It is concluded that sensitivity to both ionizing and ultraviolet radiation of neurons and glial cells in embryonic brain cultures is determined primarily by the capacity for and state of DNA replication. Neurons which have already reached the stage of terminal differentiation are more resistant than replicating neurons of glial cells

  15. Effects of X-irradiation on axonal sprouting induced by botulinum toxin

    Energy Technology Data Exchange (ETDEWEB)

    Gomez, S; Duchen, L W [National Hospital, London (UK); Hornsey, S [Hammersmith Hospital, London (UK). M.R.C. Cyclotron Unit

    1982-01-01

    The effect of X-irradiation on axonal sprouting of motor nerves induced by botulinum toxin was examined. Muscles of one leg in the mouse were X-irradiated (15Gy) prior to the injection of a locally paralysing dose of botulinum toxin. It was found that axonal sprouting occurred as expected, but the sprouts remained unmyelinated and many degenerated. Fewer new end-plates were formed, muscles remained more severely atrophied and supersensitive to acetylcholine and recovery of neuromuscular transmission was greatly delayed when compared with the effects of botulinum toxin alone. X-irradiation did not prevent sprouting but, probably by impairing Schwann cell proliferation, altered axon-Schwann cell relationships and prevented the maturation of newly-formed axons and the differentiation of new end-plates.

  16. Gluconeogenesis in lethally X-irradiated rats

    International Nuclear Information System (INIS)

    Paulikova, E.; Ahlers, I.; Praslicka, M.

    1983-01-01

    The in vivo incorporation of U- 14 C-alanine into blood glucose and liver glycogen was measured in rats irradiated with a single whole body lethal dose of X-rays. Changes in gluconeogenic enzyme activities were studied in the liver. Increased incorporation of 14 C-alanine into blood glucose and liver glycogen were found after irradiation. Liver phosphoenolpyruvate carboxykinase and glycogenic activity underwent almost parallel changes and were significantly elevated from the 6th to the 48th hour, with resultant accumulation of glycogen. Glucose-6-phosphatase activity was depressed and there was a negative correlation between it and liver glycogen concentration. Maximum fructose-1,6-diphosphatase activity was found at 48 hours. The results show that glycogen accumulation in the liver and the raised blood glucose level in X-irradiated rats are based on raised gluconeogenesis. (author)

  17. Gluconeogenesis in lethally X-irradiated rats

    Energy Technology Data Exchange (ETDEWEB)

    Paulikova, E.; Ahlers, I.; Praslicka, M. (Univerzita P.J. Safarika, Kosice (Czechoslovakia). Katedra Vseobecnej Biologie)

    1983-02-01

    The in vivo incorporation of U-/sup 14/C-alanine into blood glucose and liver glycogen was measured in rats irradiated with a single whole body lethal dose of X-rays. Changes in gluconeogenic enzyme activities were studied in the liver. Increased incorporation of /sup 14/C-alanine into blood glucose and liver glycogen were found after irradiation. Liver phosphoenolpyruvate carboxykinase and glycogenic activity underwent almost parallel changes and were significantly elevated from the 6th to the 48th hour, with resultant accumulation of glycogen. Glucose-6-phosphatase activity was depressed and there was a negative correlation between it and liver glycogen concentration. Maximum fructose-1,6-diphosphatase activity was found at 48 hours. The results show that glycogen accumulation in the liver and the raised blood glucose level in X-irradiated rats are based on raised gluconeogenesis.

  18. Radiosensitivity of mouse germ cells

    International Nuclear Information System (INIS)

    Matsuda, Yoichi; Takeuchi, Toyoko; Maemori, Mamiko; Seki, Naohiko; Tobari, Izuo

    1991-01-01

    To estimate radiosensitivity of mouse germ cells the analysis of chromosome aberrations was performed at diakinesis-metaphase I of spermatocytes and first-cleavage metaphase of one-cell embryos after exposure to radiations at various stages of primary spermatocytes and spermatids. The result provided evidence that there are two major types of DNA damage in X-irradiated sperm : (1) short-lived DNA lesions ; the lesions are subject to repair inhibition by agents added in G 1 , and are converted into chromosome-type aberrations during G 1 , and (2) long-lived DNA lesions ; the lesions persist until S phase and repair of the lesions is inhibited by caffeine, hydroxyurea and arabinofuranosyl cytosine in G 2 . The characteristic of X-ray damage induced in spermiogenic stage and repair mechanism for the damage in the fertilized egg were discussed comparing with the results with two chemicals, methyl methanesulfonate (MMS) and mitomycin C (MMC). (J.P.N.)

  19. The enhancement of radiosensitivity by celecoxib, selective cyclooxygenase-2 inhibitor, on human cancer cells expressing differential levels of cyclooxygenase-2

    International Nuclear Information System (INIS)

    Pyo, Hong Ryull; Shin, You Keun; Kim, Hyun Seok; Seong, Jin Sil; Suh, Chang Ok; Kim, Gwi Eon

    2003-01-01

    To investigate the modulation of radiosensitivity by celecoxib, a selective cyclooxygenase-2 (COX-2) inhibitor, on cancer cells over- and under-expressing COX-2. A clonogenic radiation survival analysis was performed on A549 human lung and MCF-7 human breast cancer cell lines incubated in both 1 and 10% fetal bovine serum (FBS) containing media. The apoptosis in both cell lines was measured after treatment with radiation and/or celecoxib. Celecoxib enhanced the radiation sensitivity of the A549 cells in the medium containing the 10% FBS, with radiation enhancement ratios of 1.58 and 1.81 respectively, at surviving fractions of 0.1, with 30 μ M and 50 μ M celecoxib. This enhanced radiosensitivity disappeared in the medium containing the 1% FBS. Celecoxib did not change the radiation sensitivity of the MCF-7 cells in either media. The induction of apoptosis by celecoxib and radiation was not synergistic in either cell line. Celecoxib, a selective COX-2 inhibitor, preferentially enhanced the effect of radiation on COX-2 over-expressing cancer cells compared to the cells with a low expression, and this effect disappeared on incubation of the cells during drug treatment in the medium with suboptimal serum concentration. Apoptosis did not appear to be the underlying mechanism of this radiation enhancement effect due to celecoxib on the A549 cells. These findings suggest radiosensitization by a selective COX-2 inhibitor is COX-2 dependent

  20. X-irradiation-induced emesis in Suncus murinus

    International Nuclear Information System (INIS)

    Torii, Yoshifumi; Saito, Hiroshi; Matsuki, Norio; Shikita, Mikio.

    1993-01-01

    X-irradiation-induced emesis was investigated in Suncus murinus, a house musk shrew. Whole body X-irradiation caused emesis, and the calculated ED 50 value that induced emesis in 50% of animals was 429 cGy. At the irradiation dose of 800 cGy all the animals vomited 10.0±2.4 times with a latency of 20.0±2.9 min. The emetogenic effect of X-irradiation was dependent on the part of the body exposed. Abdominal X-irradiation at 1000 cGy caused emesis in all animals studied, whereas the same dose to the head had no emetogenic effect. We investigated several prophylactic methods against X-irradiation-induced emesis. Surgical vagotomy completely inhibited the emesis induced by 800 cGy X-irradiation. Emesis was also prevented by the subcutaneous administration of tropisetron (ICS 205-930, a selective serotonergic 5-HT 3 receptor antagonist) with an ID 50 value of 29 μg/kg. These results suggest that (1) suncus is a useful experimental animal for the study of radiation-induced emesis and the development of prophylactic drugs, (2) serotonin plays an important role in X-irradiation-induced emesis, and (3) X-irradiation-induced emesis is very similar to that caused by cancer chemotherapeutic agents. (author)

  1. 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

  2. Rapid decrease in brain enkephalin content after low-dose whole-body X-irradiation of the rat

    Energy Technology Data Exchange (ETDEWEB)

    Miyachi, Yukihisa (Central Research Inst. of Electric Power Industry, Komae, Tokyo (Japan). Komae Research Lab.); Ogawa, Norio; Mori, Akitane

    1992-03-01

    Methionine-eckephalin (ME) contents in the hypothalamus and other rat brain structures were measured immediately after 10 or 20 cGy whole-body X-irradiation. The ME contents of homogenates of the striatum, hypothalamus, midbrain + thalamus, hindbrain and pituitary were assayed radioimmunologically with {sup 125}I. The contents of all the structure, except the pituitary, decreased significantly after 20 cGy irradiation. The reduction in the hypothalamus was transient, ME content gradually recovering with time. These results suggest that the central nervous system of mammals is one of the most radiosensitive organs as judged by changes in stress-induced mediators such as ME. (author).

  3. A reevaluation of X-irradiation-induced phocomelia and proximodistal limb patterning.

    Science.gov (United States)

    Galloway, Jenna L; Delgado, Irene; Ros, Maria A; Tabin, Clifford J

    2009-07-16

    Phocomelia is a devastating, rare congenital limb malformation in which the long bones are shorter than normal, with the upper portion of the limb being most severely affected. In extreme cases, the hands or fingers are attached directly to the shoulder and the most proximal elements (those closest to the shoulder) are entirely missing. This disorder, previously known in both autosomal recessive and sporadic forms, showed a marked increase in incidence in the early 1960s due to the tragic toxicological effects of the drug thalidomide, which had been prescribed as a mild sedative. This human birth defect is mimicked in developing chick limb buds exposed to X-irradiation. Both X-irradiation and thalidomide-induced phocomelia have been interpreted as patterning defects in the context of the progress zone model, which states that a cell's proximodistal identity is determined by the length of time spent in a distal limb region termed the 'progress zone'. Indeed, studies of X-irradiation-induced phocomelia have served as one of the two major experimental lines of evidence supporting the validity of the progress zone model. Here, using a combination of molecular analysis and lineage tracing in chick, we show that X-irradiation-induced phocomelia is fundamentally not a patterning defect, but rather results from a time-dependent loss of skeletal progenitors. Because skeletal condensation proceeds from the shoulder to fingers (in a proximal to distal direction), the proximal elements are differentially affected in limb buds exposed to radiation at early stages. This conclusion changes the framework for considering the effect of thalidomide and other forms of phocomelia, suggesting the possibility that the aetiology lies not in a defect in the patterning process, but rather in progenitor cell survival and differentiation. Moreover, molecular evidence that proximodistal patterning is unaffected after X-irradiation does not support the predictions of the progress zone model.

  4. A Reevaluation of X-Irradiation Induced Phocomelia and Proximodistal Limb Patterning

    Science.gov (United States)

    Galloway, Jenna L.; Delgado, Irene; Ros, Maria A.; Tabin, Clifford J.

    2009-01-01

    Phocomelia is a devastating, rare congenital limb malformation in which the long bones are shorter than normal, with the upper portion of the limb being most severely affected. In extreme cases, the hands or fingers are attached directly to the shoulder and the most proximal elements (those closest to the shoulder) are entirely missing. This disorder, previously known in both autosomal recessive and sporadic forms, showed a dramatic increase in incidence in the early 1960’s due to the tragic toxicological effects of the drug thalidomide, which had been prescribed as a mild sedative1, 2. This human birth defect is mimicked in developing chick limb buds exposed to X-irradiation3-5. Both X-irradiation5 and thalidomide-induced phocomelia5, 6 have been interpreted as patterning defects in the context of the Progress Zone Model, which states that a cell’s proximodistal (PD) identity is determined by the length of time spent in a distal limb region termed the “Progress Zone” 7. Indeed, studies of X-irradiation induced phocomelia have served as one of the two major experimental lines of evidence supporting the validity of the Progress Zone Model. Here, using a combination of molecular analysis and lineage tracing, we show that X-irradiation-induced phocomelia is fundamentally not a patterning defect, but rather results from a time-dependent loss of skeletal progenitors. As skeletal condensation proceeds from the shoulder to fingers (in a proximal to distal direction), the proximal elements are differentially affected in limb buds exposed to radiation at early stages. This conclusion changes the framework for considering the effect of thalidomide and other forms of phocomelia, suggesting the possibility that the etiology lies not in a defect in the patterning process, but rather in progenitor cell survival and differentiation. Moreover, molecular evidence that PD patterning is unaffected following X-irradiation does not support the predictions of the Progress Zone

  5. Ultrastructural and cytochemical study of membrane alterations in x-irradiated liver tissue from normal and vitamin E-deficient ducklings

    International Nuclear Information System (INIS)

    Huijbers, W.A.R.; Oosterbaan, J.A.; Meskendorp-Haarsma, T.J.; Hardonk, M.J.; Molenaar, I.

    1979-01-01

    An investigation into the differential susceptibility of liver cellular membranes to peroxidative processes has been performed, using x irradiation on the liver surface, resulting in a a 3-mm penetrating gradient of membrane damage. Ultrastructural, cytochemical, and histochemical findings in this area point to a differential sensitivity of cellular membranes to x irradiation. The plasma membrane and the lysosomal membrane, containing much lipid and cholesterol and little membrane and the lysosomal membrane, containing much lipid and cholesterol and little vitamin E, are highly susceptible to x irradiation. Less sensitive are the membranes of mitochondria and endoplasmic reticulum, containing relatively much vitamin E and proteins and a lower amount of lipids and cholesterol

  6. In vivo radiosensitization by diethyldithiocarbamate

    International Nuclear Information System (INIS)

    Kent, C.R.; Blekkenhorst, G.H.

    1988-01-01

    Diethyldithiocarbamate (DDC) has been suggested to have both radiosensitizing (due to superoxide dismutase (SOD) inhibition) and radioprotective properties. We have studied the activity of SOD up to 24 h after intratumoral administration of 50, 100, 150, and 300 mg/kg DDC in 3-methylcholanthrene-induced tumors in BALB/c mice. Maximal inhibition of SOD (8% of control) was obtained 1 h after administration of 100 mg/kg DDC. Tumor response to DDC and X irradiation was assessed using a tumor growth-delay assay, after 11 Gy 100-kVp X rays given up to 24 h after DDC administration. Radiation-induced tumor growth delay (7.11 +/- 1.76 days) was enhanced only when tumors were irradiated 2-4 h after 50 mg/kg DDC. When higher doses of DDC were used, tumor cure was noted when DDC was injected 1-6 h before irradiation. We suggest our findings are consistent with radiosensitization being due to SOD inhibition, but that if insufficient time is allowed between DDC injection and irradiation, the sensitization is masked by a radioprotective effect. We believe that further investigations as to the therapeutic potential of DDC in human patients with cancer are warranted

  7. Synergism of X irradiation and radiographic contrast medium

    Energy Technology Data Exchange (ETDEWEB)

    Carr, D; Walker, A; Tannahill, A J; White, R G [Glasgow Western Infirmary (UK)

    1981-10-01

    The results indicate that rabbits which had received abdominal x irradiation (750 rad) two hours before RCM (/sup 125/I-labelled meglumine ioglycamate) administration retained a significantly larger amount of RCM in the kidney, liver, spleen and plasma compared with animals which had received RCM with no prior x irradiation. There was no significant difference between the group receiving RCM alone and the group receiving RCM 24 h post-irradiation. With two insignificant exceptions, endotoxin assays were negative.

  8. 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

  9. Differential sensitivity of p53+ and p53- cells to caffeine-induced radiosensitization and override of G2 delay

    International Nuclear Information System (INIS)

    Powell, S.N.; DeFrank, J.S.; Connell, P.; Eogan, M.; Preffer, F.; Dombkowski, D.; Tang, W.; Friend, S.H.

    1995-01-01

    Purpose: Most drug discovery efforts have focused on finding new DNA damaging agents to kill tumor cells preferentially. An alternative approach is to find ways to increase tumor specific killing by modifying tumor specific responses to that damage. We asked whether cells lacking the G1/S arrest in response to X-rays are more sensitive to X-ray damage when treated with agents that override G2/M arrest. Materials and Methods: Mouse embryonic fibroblasts genetically matched to be (+/+) or (-/-) p53 and rat embryonic fibroblasts (REF) made (+) or (-) for wild-type p53 function by transfection were irradiated with and without caffeine, a known checkpoint inhibitor. Caffeine treatment was maintained for 24 hours from 1 hour prior to irradiation. Cell survival following ionizing radiation was measured by clonogenic assay. For cell-cycle analysis, cells were in exponential asynchronous growth at the time of irradiation. The proportion of cells in G1, S and G2/M phases of the cell cycle were recorded immediately before and following irradiation and subsequently at 3,6,9,12,24 and 48 hours following irradiation. Results: Caffeine was found to cause radiosensitzation at low dose (0.5mM) in (-/-) cells but not in (+/+) cells. The sensitization enhancement ratio (SER) was 1.45 at 0.1 survival and 1.56 at 0.01 survival. At this dose of caffeine, this SER reflected therapeutic gain as there was no detectable effect on (+/+) cells. At 1mM caffeine, sensitization of (-/-) cells was 1.77, but (+/+) cells now also showed sensitization (SER=1.25). In (-/-) cells at 0.1mM caffeine the SER was 1.5 at 0.01 survival. The transfected REF cells (functionally null for p53) also exhibited caffeine-induced radiosensitization at both 0.5 and 2mM caffeine with a SER 1.45 for 2mM at 0.1 survival. No significant sensitization could be demonstrated for REF cells at the same doses of caffeine. The REF cells, with wild-type p53, transfected with pCMVneo alone showed no change in radiosensitivity or

  10. Synergism between two helper cell subpopulations characterized by different radiosensitivity and nylon adherence

    International Nuclear Information System (INIS)

    Agarossi, G.; Mancini, C.; Doria, G.

    1981-01-01

    The present work extends our previous results on the radiosensitivity of the helper cell function. Two helper cell subpopulations, 1 radiosensitive and the other radioresistant, have been demonstrated in the spleen of mice at different times after priming with HRBC. The radiosensitive subpopulation increases with the increasing time interval between carrier-priming and irradiation. The 2 cell subpopulations have been further characterized by different nylon adherence properties: radioresistant helper cells adhere to nylon wool, whereas radiosensitive cells pass through. The 2 cell subpopulations were separated by x-irradiation and nylon wool filtration, and their helper activity was assessed separately or after recombination. The results favor the notion that 2 functionally independent helper T cells, as characterized by different radiosensitivity and nylon adherence, participate synergistically in the helper activity of primed spleen cells

  11. Possible genetic damage from diagnostic x irradiation. A review

    International Nuclear Information System (INIS)

    Withrow, T.J.; Andersen, F.A.; Yao, K.T.S.; Stratmeyer, M.E.

    1980-08-01

    Although it is known that x irradiation is capable of producing mutations and chromosomal abnormalities in experimental systems, there is little or no direct evidence of such phenomena in humans. This report reviews some human genetic diseases and chromosomal abnormalities as well as the evidence for x-ray induced mutations and chromosomal abnormalities in experimental systems. The examination of these areas reveals that spontaneous chromosomal abnormalities and genetic diseases are associated with the same type of DNA damage that x irradiation produces in experimental systems. Therefore, it is concluded that genetic radiation damage in humans may mainfest itself as an increase in the spontaneous genetic diseases rather than as any unique disease

  12. Radiosensitivity of higher plants

    International Nuclear Information System (INIS)

    Feng Zhijie

    1992-11-01

    The general views on radiosensitivity of higher plants have been introduced from published references. The radiosensitivity varies with species, varieties and organs or tissues. The main factors of determining the radiosensitivity in different species are nucleus volume, chromosome volume, DNA content and endogenous compounds. The self-repair ability of DNA damage and chemical group of biological molecules, such as -SH thiohydroxy of proteins, are main factors to determine the radiosensitivity in different varieties. The moisture, oxygen, temperature radiosensitizer and protector are important external factors for radiosensitivity. Both the multiple target model and Chadwick-Leenhouts model are ideal mathematical models for describing the radiosensitivity of higher plants and the latter has more clear significance in biology

  13. Analysis of the factors in determining radiosensitivity in mammalian cells by using radio-sensitive and -resistant clones isolated from HeLa S3 cells in vitro

    International Nuclear Information System (INIS)

    Nikaido, Osamu; Horikawa, Masakatsu

    1976-01-01

    The factors in determining radiosensitivity of cultured mammalian cells were analysed by using two clones each having different radiosensitivities. The radiosensitive clones were isolated from HeLa S3 cells by the N-methyl-N'-nitro-N-nitrosoguanidine (MNNG)-treatment, X-irradiation (200 R) and 5-bromodeoxyuridine (BUdR)-visible light method. On the other hand, the radioresistant clone was isolated by single X-irradiation (2000 R) from MNNG-treated HeLa S3 cell population. The radiosensitivities expressed in D sub(o) and D sub(q) values were 110 and 140 R in radiosensitive SM-1a clone and 180 and 230 R in radioresistant RM-1b clone respectively. The biological and biochemical characteristics of both clones such as the distribution of chromosome numbers, formation and rejoining of single strand breaks in DNA caused by X-irradiation, non-protein sulfhydryl (NPSH) and apparent total sulfhydryl (APSH) contents were measured. Among the characteristics analysed, different contents of NPSH in the cell were well correlated to their daiosensitivities among the original HeLa S3 cells, SM-1a and RM-1b clone. Additionally, it was found that the radioresistant L.P3 Co-3 cells isolated by Tsuboi et al. from the original mouse L.P3 cells by means of serial irradiation with 60 Co γ-rays have more abundant NPSH than the original L.P3 cells. From these results, it can be concluded that the amount of NPSH play the main role in determining radiosensitivity in cultured mammalian cells. (auth.)

  14. Isothermal annealing kinetics of X-irradiated pyrene by EPR

    International Nuclear Information System (INIS)

    Partiti, C.S.M.; Pontuschka, W.M.; Fazzio, A.; Piccini, A.

    1989-07-01

    The annealing behavior of X-irradiated stable free radicals found in Pyrene (C 16 H 10 ) single crystals was studied by EPR. Two processes of thermal decay kinetics were found, both with the same activation energy (1.9±0.1) ev. (author) [pt

  15. Transgenerational developmental effects and genomic instability after X-irradiation of preimplantation embryos: Studies on two mouse strains

    International Nuclear Information System (INIS)

    Jacquet, P.; Buset, J.; Neefs, M.; Vankerkom, J.; Benotmane, M.A.; Derradji, H.; Hildebrandt, G.; Baatout, S.

    2010-01-01

    Recent results have shown that irradiation of a single cell, the zygote or 1-cell embryo of various mouse strains, could lead to congenital anomalies in the fetuses. In the Heiligenberger strain, a link between the radiation-induced congenital anomalies and the development of a genomic instability was also suggested. Moreover, further studies showed that in that strain, both congenital anomalies and genomic instability could be transmitted to the next generation. The aim of the experiments described in this paper was to investigate whether such non-targeted transgenerational effects could also be observed in two other radiosensitive mouse strains (CF1 and ICR), using lower radiation doses. Irradiation of the CF1 and ICR female zygotes with 0.2 or 0.4 Gy did not result in a decrease of their fertility after birth, when they had reached sexual maturity. Moreover, females of both strains that had been X-irradiated with 0.2 Gy exhibited higher rates of pregnancy, less resorptions and more living fetuses. Additionally, the mean weight of living fetuses in these groups had significantly increased. Exencephaly and dwarfism were observed in CF1 fetuses issued from control and X-irradiated females. In the control group of that strain, polydactyly and limb deformity were also found. The yields of abnormal fetuses did not differ significantly between the control and X-irradiated groups. Polydactyly, exencephaly and dwarfism were observed in fetuses issued from ICR control females. In addition to these anomalies, gastroschisis, curly tail and open eye were observed at low frequencies in ICR fetuses issued from X-irradiated females. Again, the frequencies of abnormal fetuses found in the different groups did not differ significantly. In both CF1 and ICR mouse strains, irradiation of female zygotes did not result in the development of a genomic instability in the next generation embryos. Overall, our results suggest that, at the moderate doses used, developmental defects

  16. Transgenerational developmental effects and genomic instability after X-irradiation of preimplantation embryos: Studies on two mouse strains

    Energy Technology Data Exchange (ETDEWEB)

    Jacquet, P., E-mail: pjacquet@sckcen.be [Molecular and Cellular Biology, Institute for Environment, Health and Safety, SCK.CEN, Boeretang 200, B-2400 Mol (Belgium); Buset, J.; Neefs, M. [Molecular and Cellular Biology, Institute for Environment, Health and Safety, SCK.CEN, Boeretang 200, B-2400 Mol (Belgium); Vankerkom, J. [Division of Environmental Research, VITO, Boeretang 200, B-2400 Mol (Belgium); Benotmane, M.A.; Derradji, H. [Molecular and Cellular Biology, Institute for Environment, Health and Safety, SCK.CEN, Boeretang 200, B-2400 Mol (Belgium); Hildebrandt, G. [Department of Radiotherapy and Radiation Oncology, University of Leipzig, Stephanstrasse 9a, D-04103 Leipzig (Germany); Department of Radiotherapy, University of Rostock, Suedring 75, D-18059 Rostock (Germany); Baatout, S. [Molecular and Cellular Biology, Institute for Environment, Health and Safety, SCK.CEN, Boeretang 200, B-2400 Mol (Belgium)

    2010-05-01

    Recent results have shown that irradiation of a single cell, the zygote or 1-cell embryo of various mouse strains, could lead to congenital anomalies in the fetuses. In the Heiligenberger strain, a link between the radiation-induced congenital anomalies and the development of a genomic instability was also suggested. Moreover, further studies showed that in that strain, both congenital anomalies and genomic instability could be transmitted to the next generation. The aim of the experiments described in this paper was to investigate whether such non-targeted transgenerational effects could also be observed in two other radiosensitive mouse strains (CF1 and ICR), using lower radiation doses. Irradiation of the CF1 and ICR female zygotes with 0.2 or 0.4 Gy did not result in a decrease of their fertility after birth, when they had reached sexual maturity. Moreover, females of both strains that had been X-irradiated with 0.2 Gy exhibited higher rates of pregnancy, less resorptions and more living fetuses. Additionally, the mean weight of living fetuses in these groups had significantly increased. Exencephaly and dwarfism were observed in CF1 fetuses issued from control and X-irradiated females. In the control group of that strain, polydactyly and limb deformity were also found. The yields of abnormal fetuses did not differ significantly between the control and X-irradiated groups. Polydactyly, exencephaly and dwarfism were observed in fetuses issued from ICR control females. In addition to these anomalies, gastroschisis, curly tail and open eye were observed at low frequencies in ICR fetuses issued from X-irradiated females. Again, the frequencies of abnormal fetuses found in the different groups did not differ significantly. In both CF1 and ICR mouse strains, irradiation of female zygotes did not result in the development of a genomic instability in the next generation embryos. Overall, our results suggest that, at the moderate doses used, developmental defects

  17. Effects of x-irradiation on steroid biotransformations by testicular tissue. Final report, May 1, 1966--July 31, 1976. [Rats

    Energy Technology Data Exchange (ETDEWEB)

    Ellis, L.C.

    1976-08-01

    A number of parameters of testicular and body function were investigated after various dosages of x-irradiation to ascertain: what relationship they have to the radiation syndrome and testicular repression and regeneration of the rat; and how sensitive these parameters are to radiation. Changes in androgen synthesis were not well correlated with either body or gonad weights, hematocrit values or testicular histology. Lipid peroxidation, catalase activity, metabolism of testosterone, prostaglandins, cyclic nucleotides and serotonin metabolism were all related to the direct effects of radiation on the male gonad. Indirect effects on the testis appear to be mediated by serotonin and the pineal gland. The pineal gland appeared to be responsible for variations in androgen synthesis and radiosensitivity of the testis through its secretory products-melatonin and arginine vasopressin. These compounds have the capacity of inducing endocrine rhythms by affecting: the hypothalamus-pituitary axis; the liver; and/or the gonad directly.

  18. Effects of x-irradiation on steroid biotransformations by testicular tissue. Final report, May 1, 1966--July 31, 1976

    International Nuclear Information System (INIS)

    Ellis, L.C.

    1976-08-01

    A number of parameters of testicular and body function were investigated after various dosages of x-irradiation to ascertain: what relationship they have to the radiation syndrome and testicular repression and regeneration of the rat; and how sensitive these parameters are to radiation. Changes in androgen synthesis were not well correlated with either body or gonad weights, hematocrit values or testicular histology. Lipid peroxidation, catalase activity, metabolism of testosterone, prostaglandins, cyclic nucleotides and serotonin metabolism were all related to the direct effects of radiation on the male gonad. Indirect effects on the testis appear to be mediated by serotonin and the pineal gland. The pineal gland appeared to be responsible for variations in androgen synthesis and radiosensitivity of the testis through its secretory products-melatonin and arginine vasopressin. These compounds have the capacity of inducing endocrine rhythms by affecting: the hypothalamus-pituitary axis; the liver; and/or the gonad directly

  19. Sister chromatid exchange induced by X-irradiation of retinoblastoma lymphocytes

    International Nuclear Information System (INIS)

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

    1984-01-01

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

  20. Ferritin-iron increases killing of Chinese hamster ovary cells by X-irradiation

    International Nuclear Information System (INIS)

    Nelson, J.M.; Stevens, R.G.

    1992-01-01

    Stationary-phase Chinese hamster ovary cells were cultured in medium containing ferritin (∼19% iron by weight) added at concentrations ranging from 0 to 128 μg/ml. One set of cultures was unirradiated, another set exposed to 4.0 Gy of X-ray. Clonogenic cell survival was assessed in each set of cultures. In the absence of added ferritin, 4.0 Gy killed approximately 50% of the cells. In the absence of radiation, ferritin was not toxic at less than 48 μg/ml; above 48 μg/ml, toxicity increased with concentration. Apoferritin was not toxic at any concentration tested (up to 1000 μg/ml). Although 32 μg/ml ferritin, reflecting only a 3-6 fold increase in iron concentration over normal serum, was not toxic, it reduced survival of X-irradiated cells by an additional 75%. These results indicate that a sublethal concentration of ferritin can be a potent radiosensitizer. (Author)

  1. The effects of low dose X-irradiation on osteoblastic MC3T3-E1 cells in vitro

    Directory of Open Access Journals (Sweden)

    Xu Wei

    2012-06-01

    Full Text Available Abstract Background It has been indicated that moderate or high dose of X-irradiation could delay fracture union and cause osteoradionecrosis, in part, mediated by its effect on proliferation and differentiation of osteoblasts. However, whether low dose irradiation (LDI has similar roles on osteoblasts is still unknown. In this study, we investigated whether and to what extent LDI could affect the proliferation, differentiation and mineralization of osteoblasts in vitro. Methods The MC3T3-E1 cells were exposed to single dose of X-irradiation with 0, 0.1, 0.5, 1.0 Gy respectively. Cell proliferation, apoptosis, alkaline phosphatase (ALP activity, and mineralization was evaluated by methylthiazoletetrazolium (MTT and bromodeoxyuridine (BrdU assay, flow cytometry, ALP viability kit and von Kossa staining, respectively. Osteocalcin (OCN and core-binding factor α1 (Cbfα1 expressions were measured by real time-PCR and western blot, respectively. Results The proliferation of the cells exposed to 2.0 Gy was significantly lower than those exposed to ≤1.0 Gy (p  Conclusions LDI have different effects on proliferation and differentiation of osteoblasts from those of high dose of X-irradiation, which might suggest that LDI could lead to promotion of frature healing through enhancing the differentiation and mineralization of osteoblasts.

  2. A comparative study on radiosensitivity of neonatal ducks and chickens

    International Nuclear Information System (INIS)

    Nakanishi, Y.H.; Ogata, Kenji; Sugimura, Makoto

    1979-01-01

    Neonatal ducks and chickens are exposed to a wholebody X-irradiation ranging from 100 R to 3,000 R at a dose-rate of 185 R per min. Lethal doses to 50% in 30 days are estimated to be 500 R for the ducks, while 800 R for the chickens. The ducks appear to be much more radiosensitive than the chickens. Histopathological observations of various organs of the exposed specimens after death reveal remarkable alterations: Particularly lymphoid organs are affected much more in the ducks than in the chickens at lesser doses than 1,000 R. (author)

  3. Comparative study on radiosensitivity of neonatal ducks and chickens

    Energy Technology Data Exchange (ETDEWEB)

    Nakanishi, Y H; Ogata, K; Sugimura, M [Hokkaido Univ., Sapporo (Japan)

    1979-05-01

    Neonatal ducks and chickens are exposed to a wholebody X-irradiation ranging from 100 R to 3,000 R at a dose-rate of 185 R per min. Lethal doses to 50% in 30 days are estimated to be 500 R for the ducks, while 800 R for the chickens. The ducks appear to be much more radiosensitive than the chickens. Histopathological observations of various organs of the exposed specimens after death reveal remarkable alterations: Particularly lymphoid organs are affected much more in the ducks than in the chickens at lesser doses than 1,000 R.

  4. Assessment of in vitro radiosensitivity of human peripheral blood lymphocytes

    International Nuclear Information System (INIS)

    Knox, S.J.; Shifrine, M.; Rosenblatt, L.S.

    1980-01-01

    The proliferative capacity of sensitive lymphocyte progenitor cells, from thirty-one clinically normal adults, was evaluated following in vitro x-irradiation (0-400R). Radiation effects were studied using both whole blood and lymphocyte-enriched mononuclear cell fractions in the lymphocyte stimulation test and colony formation assay with 6 different mitogens and antigens. Radiation dose-response survival curves were determined for the different test groups. The sensitivity of the different assay systems is compared and normative values are presented that may be used for comparison purposes to determine the relative radiosensitivity of atypical individuals and groups of individuals

  5. Clinical outcomes of childhood x-irradiation for lymphoid hyperplasia

    International Nuclear Information System (INIS)

    Pottern, L.M.

    1987-01-01

    A prospective study was conducted to explore the relationship between childhood x-irradiation for lymphoid hyperplasia and the subsequent development of thyroid gland and other head and neck disorders. All individuals under 18 years of age who were x-irradiated for lymphoid hyperplasia during the years 1938-69 at Children's Hospital Medical Center, Boston comprised the exposed population. The comparison group consisted of non-exposed, surgically treated individuals. The study included a health questionnaire and a clinical examination component. A history of thyroid cancer was reported by 11 exposed subjects and no non-exposed subjects. Significantly elevated standardized incidence ratios of thyroid cancer were seen for both exposed males and females, 19.9 and 12.1, respectively. The average thyroid radiation dose was 25.8 rads and the mean latency period was 17.3 years

  6. Radiosensitization, mutagenicity, and toxicity of Escherichia coli by several nitrofurans and nitroimidazoles. [X radiation

    Energy Technology Data Exchange (ETDEWEB)

    Chessin, H.; McLaughlin, T.; Mroczkowski, Z.; Rupp, W.D.; Low, K.B.

    1978-08-01

    Representative nitrofurans (nitrofurantoin, nifuroxime, NF-167, NF-269) and nitroimidazoles (metronidazole, misonidazole) were found to sensitize hypoxic RecA/sup -/ Escherichia coli cells to X irradiation. These compounds were also mutagenic to E. coli using a UvrA/sup -/ strain as a test system, and toxic at high concentrations, using several strains differing in their repair capacity. However, the relative degrees of radiosensitization, mutagenicity, and toxicity, for the various compounds, were not simply correlated, suggesting that potential radiosensitizers with fewer side effects could be screened using bacteria.

  7. Protein synthesis in x-irradiated rabbit lens

    International Nuclear Information System (INIS)

    Garadi, R.; Foltyn, A.R.; Giblin, F.J.; Reddy, V.N.

    1984-01-01

    The present study deals with the incorporation of 35 S methionine into lens crystallins as a function of time after x-irradiation. Crystallin synthesis is first affected approximately 4 weeks following x-irradiation. This coincides with the time period at which the ratio of the two cations in the lens is affected, as shown in earlier studies. A greater decrease in 35 S-methionine incorporation into crystallins is observed between 5-7 weeks following x-irradiation in good agreement with a cation imbalance at these time intervals. These studies also revealed for the first time that the change in cation distribution can affect not only crystallin synthesis, but also the synthesis of certain polypeptides of lens membranes. No alteration in protein synthesis could be detected in lens epithelium even after 7 weeks following irradiation. In addition to the effect of Na+ and K+ levels on protein synthesis, an impaired transport of amino acids into the x-rayed lens was also found to be a factor in the observed reduction in synthesis of the crystallin, cytoskeletal and membrane proteins of the fiber cells. It is concluded that Na+/K+ ratio as well as the availability of amino acids in the lens are important factors in protein synthesis of x-ray cataracts

  8. Morphological profiles of neutron and X-irradiated small intestine

    International Nuclear Information System (INIS)

    Carr, K.E.; O'Shea, O.; Hazzard, R.A.; McCullough, J.S.; Hume, S.P.; Nelson, A.C.

    1996-01-01

    This paper describes the response of mouse small intestine, at several time points after treatment with neutron or X-irradiation, using doses expected to give similar effects in terms of crypt/microcolony survival. Using resin histology, the effects of radiation on the numbers of duodenal cell types and measurements of tissue areas were assessed. The results for individual parameters and for an estimate of overall damage are given in a data display, which summarises the morphological profile of the organ after both types of radiation. Damage and recovery were seen for many of the parameters studied but there was no standard response pattern applicable for all parameters. In particular, the response of individual crypt cell types could not be predicted from knowledge of the change in crypt numbers. With regard to the holistic response of the gut, neutron irradiation appeared to have caused more damage and produced more early effects than the X-irradiation. More specifically, neutron treatment led to more damage to the neuromuscular components of the wall, while X-irradiation produced early vascular changes. (author)

  9. G{sub 2} radiosensitivity of cells derived from cancer-prone individuals

    Energy Technology Data Exchange (ETDEWEB)

    Darroudi, F.; Vyas, R.C.; Vermeulen, S.; Natarajan, A.T. [J.A. Cohen Institute of Radiopathology and Radiation Protection, Interuniversity Institute, Leiden (Netherlands)

    1995-04-01

    The potential of enhanced chromatid damage, observed after X-irradiation of G{sub 2} phase, has been used to detect individuals genetically predisposed to cancer, utilising fibroblasts/lymphocytes from these patients as well as fibroblasts derived from human tumours. Fibroblasts and/or lymphocyte samples of two autosomal recessive syndromes (xeroderma pigmentosum (XP), Fanconi`s anaemia (FA)) and one congenital or acquired disorder, aplastic anaemia (AA), were employed for the G{sub 2} radiosensitivity assay. In addition, we have estimated the frequencies of spontaneously occurring chromosomal aberrations as well as G{sub 2} radiosensitivity of eight samples of fibroblasts/fibroblast-like cells (two normal, two colorectal carcinoma, two Wilms` tumour, one retinoblastoma and one polyposis coli), and three samples of lymphocytes (two normal and one from a lymphoma patient). The results obtained indicate that there were no differences between fibroblast cells derived from patients or tumours, except FA patients, in the frequency of spontaneously occurring chromosomal aberrations when compared to normal cells. Following X-irradiation we did not observe any significantly increased G{sub 2} radiosensitivity in FA and XP cells. Lymphocytes from AA and lymphoma patients, and all tumour cell lines except retinoblastoma, responded with increased frequencies of aberrations following G{sub 2} X-irradiation in comparison to cells derived from normal individuals. In our hands, the G{sub 2} sensitivity assay could not always discriminate cells from cancer-prone individuals from those of controls.

  10. Pharmacological targeting of the ephrin receptor kinase signalling by GLPG1790 in vitro and in vivo reverts oncophenotype, induces myogenic differentiation and radiosensitizes embryonal rhabdomyosarcoma cells

    Directory of Open Access Journals (Sweden)

    Francesca Megiorni

    2017-10-01

    Full Text Available Abstract Background EPH (erythropoietin-producing hepatocellular receptors are clinically relevant targets in several malignancies. This report describes the effects of GLPG1790, a new potent pan-EPH inhibitor, in human embryonal rhabdomyosarcoma (ERMS cell lines. Methods EPH-A2 and Ephrin-A1 mRNA expression was quantified by real-time PCR in 14 ERMS tumour samples and in normal skeletal muscle (NSM. GLPG1790 effects were tested in RD and TE671 cell lines, two in vitro models of ERMS, by performing flow cytometry analysis, Western blotting and immunofluorescence experiments. RNA interfering experiments were performed to assess the role of specific EPH receptors. Radiations were delivered using an x-6 MV photon linear accelerator. GLPG1790 (30 mg/kg in vivo activity alone or in combination with irradiation (2 Gy was determined in murine xenografts. Results Our study showed, for the first time, a significant upregulation of EPH-A2 receptor and Ephrin-A1 ligand in ERMS primary biopsies in comparison to NSM. GLPG1790 in vitro induced G1-growth arrest as demonstrated by Rb, Cyclin A and Cyclin B1 decrease, as well as by p21 and p27 increment. GLPG1790 reduced migratory capacity and clonogenic potential of ERMS cells, prevented rhabdosphere formation and downregulated CD133, CXCR4 and Nanog stem cell markers. Drug treatment committed ERMS cells towards skeletal muscle differentiation by inducing a myogenic-like phenotype and increasing MYOD1, Myogenin and MyHC levels. Furthermore, GLPG1790 significantly radiosensitized ERMS cells by impairing the DNA double-strand break repair pathway. Silencing of both EPH-A2 and EPH-B2, two receptors preferentially targeted by GLPG1790, closely matched the effects of the EPH pharmacological inhibition. GLPG1790 and radiation combined treatments reduced tumour mass by 83% in mouse TE671 xenografts. Conclusions Taken together, our data suggest that altered EPH signalling plays a key role in ERMS development and that

  11. Resistance of transplantation tolerance to X-irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Holan, V; Hasek, M; Chutna, J [Czechoslovak Academy of Sciences, Prague. Institute of Molecular Genetics

    1979-04-01

    With regard to the previous finding that suppressor cells participating in the state of transplantation tolerance were radiosensitive, the possibility was investigated whether tolerance can be abolished by irradiation. In the rat model used (AVN recipients, Lewis donors), both neonatally induced tolerance and tolerance induced in the adult life by the transfer of suppressor cells were found to be radioresistant.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1984-12-01

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

  13. Correlation between slowly repairable double-strand breaks and thermal radiosensitization in the human HeLa S3 cell line

    NARCIS (Netherlands)

    Kampinga, HH; Hiemstra, YS; Konings, AWT; Dikomey, E

    The effect of heat on double-strand breaks (dsb) repair was compared with thermal radiosensitization using HeLa S3 cells. Cells were exposed to a combined treatment of X-irradiation followed by heat (44 degrees C, 0.5 h) separated by time intervals up to 8h. DNA dsb were measured by PFGE and

  14. Effects of x-irradiation on lens reducing systems

    International Nuclear Information System (INIS)

    Giblin, F.J.; Chakrapani, B.; Reddy, V.N.

    1978-01-01

    Studies have been made of the effects of x ray on various lens reducing systems including the levels of NADPH and glutathione (GSH), the activity of the hexose monophosphate shunt (HMS), and the activities of certain enzymes including glutathion reductase, glutathione peroxidase, and glucose-6-phosphate dehydrogenase (G-6-PD). It was found that during several weeks following x irradiation but prior to cataract formation there was very little change in the number of reduced -SH groups per unit weight of lens protein but that, with the appearance of cataract, there was a sudden loss of protein -SH groups. In contrast, the concentration of GSH in the x-rayed lens decreased throughout the experimental period. Similarly, the concentration of NADPH in the x-rayed lens was found to decrease significantly relative to controls one week prior to cataract formation and the ratio of NADPH to NADP + in the lens shifted at this time period from a value greater than 1.0 in the control lens to less than 1.0 in the x-rayed lens. A corresponding decrease occurred in the activity of the HMS in x-rayed lenses as measured by culture in the presence of 1- 14 C-labelled glucose. G-6-PD was partially inactivated in the x-rayed lens. Of the eight enzymes studied, G-6-PD appeared to be the most sensitive to x-irradiation. The data indicate that x-irradiation results in a steady decrease in the effectiveness of lens reducing systems and that, when these systems reach a critically low point, sudden oxidation of protein -SH groups and formation of high molecular weight protein aggregates may be initiated

  15. Effects of x-irradiation on lens reducing systems. [Rabbits

    Energy Technology Data Exchange (ETDEWEB)

    Giblin, F.J.; Chakrapani, B.; Reddy, V.N.

    1978-01-01

    Studies have been made of the effects of x ray on various lens reducing systems including the levels of NADPH and glutathione (GSH), the activity of the hexose monophosphate shunt (HMS), and the activities of certain enzymes including glutathion reductase, glutathione peroxidase, and glucose-6-phosphate dehydrogenase (G-6-PD). It was found that during several weeks following x irradiation but prior to cataract formation there was very little change in the number of reduced -SH groups per unit weight of lens protein but that, with the appearance of cataract, there was a sudden loss of protein -SH groups. In contrast, the concentration of GSH in the x-rayed lens decreased throughout the experimental period. Similarly, the concentration of NADPH in the x-rayed lens was found to decrease significantly relative to controls one week prior to cataract formation and the ratio of NADPH to NADP/sup +/ in the lens shifted at this time period from a value greater than 1.0 in the control lens to less than 1.0 in the x-rayed lens. A corresponding decrease occurred in the activity of the HMS in x-rayed lenses as measured by culture in the presence of 1-/sup 14/C-labelled glucose. G-6-PD was partially inactivated in the x-rayed lens. Of the eight enzymes studied, G-6-PD appeared to be the most sensitive to x-irradiation. The data indicate that x-irradiation results in a steady decrease in the effectiveness of lens reducing systems and that, when these systems reach a critically low point, sudden oxidation of protein -SH groups and formation of high molecular weight protein aggregates may be initiated.

  16. Radiosensitizers and protectors

    International Nuclear Information System (INIS)

    Nori, D.; Kim, J.H.; Hilaris, B.; Chu, F.C.

    1987-01-01

    Over the past decades, various physical, biological, and clinical strategies have been investigated to improve the therapeutic effectiveness of radiation. One of these efforts has been to develop chemical radiosensitizers and protectors. In the broadest sense, a radiation sensitizer is any agent that enhances the cytolethal effects of radiation. Drugs that selectively protect tissues from radiation injury are under active study. This chapter briefly reviews the present status of chemical radiosensitizers and protectors. The discussion of sensitizers will be limited to the oxic cell and hypoxic cell radiosensitizers and their clinical applications

  17. Radiation effects in x-irradiated hydroxy compounds

    International Nuclear Information System (INIS)

    Budzinski, E.E.; Potter, W.R.; Box, H.C.

    1980-01-01

    Radiation effects are compared in single crystals of xylitol, sorbitol, and dulcitol x-irradiated at 4.2 0 K. In xylitol and dulcitol, but not in sorbitol, a primary oxidation product is identified as an alkoxy radical. ENDOR measurements detected three proton hyperfine couplings associated with the alkoxy ESR absorption, one of which is attributed to a proton three bond lengths removed from the seat of unpaired spin density. Intermolecular trapping of electrons is observed in all three crystals. ENDOR measurements were made of the hyperfine couplings between the trapped electron and the hydroxy protons forming the trap

  18. 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)

  19. Effect of head x-irradiation on adrenal medullary secretion

    International Nuclear Information System (INIS)

    Mieno, Masahiro

    1977-01-01

    The purpose of the present experiments was to investigate an immediate effect of head x-irradiation on the secretion of adrenaline and noradrenaline by the adrenal medulla. When the dogs were irradiated with 200 or 800 R of x-rays to their heads under pentobarbital anesthesia, the majority of the animals showed no stimulation of the adrenal medulla but the minority showed a slight but definite increase in the secretion of adrenaline, the peak being attained within 60 min after exposure. (auth.)

  20. Radiosensitivity of glial progenitor cells of the perinatal and adult rat optic nerve studied by an in vitro clonogenic assay

    International Nuclear Information System (INIS)

    Maazen, R.W.M. van der; Verhagen, I.; Kleiboer, B.J.; Kogel, A.J. van der

    1991-01-01

    The cellular basis of radiation-induced demyelination and white matter necrosis of the central nervous system (CNS), is poorly understood. Glial cells responsible for myelination in the CNS might be the target cells of this type of damage. Glial cells with stem cell properties derived from the perinatal and adult rat CNS can be cultured in vitro. These cells are able to differentiate into oligodendrocytes or type-2 astrocytes (O-2A) depending on the culture conditions. Growth factors produced by monolayers of type-1 astrocytes inhibit premature differentiation of O-2A progenitor cells and allow colony formation. A method which employs these monolayers of type-1 astrocytes to culture O-2A progenitor cells has been adapted to allow the analysis of colonies of surviving cells after X-irradiation. In vitro survival curves were obtained for glial progenitor cells derived from perinatal and adult optic nerves. The intrinsic radiosensitivity of perinatal and adult O-2A progenitor cells showed a large difference. Perinatal O-2A progenitor cells are quite radiosensitive, in contrast to adult O-2A progenitor cells. For both cell types an inverse relationship was found between the dose and the size of colonies derived from surviving cells. Surviving O-2A progenitor cells maintain their ability to differentiate into oligo-dendrocytes or type-2 astrocytes. This system to assess radiation-induced damage to glial progenitor cells in vitro systems to have a great potential in unraveling the cellular basis of radiation-induced demyelinating syndromes of the CNS. (author). 28 refs.; 4 figs.; 1 tab

  1. Radiosensitivity of fingermillet genotypes

    Energy Technology Data Exchange (ETDEWEB)

    Raveendran, T S; Nagarajan, C; Appadurai, R; Prasad, M N; Sundaresan, N [Tamil Nadu Agricultural Univ., Coimbatore (India)

    1984-07-01

    Varietal differences in radiosensitivity were observed in a study involving 4 genotypes of fingermillet (Eleusine coracana (Linn.) Gaertn.) subjected to gamma-irradiation. Harder seeds were found to tolerate a higher dose of the mutagen.

  2. Hypothalamic-pituitary-testicular system following testicular X-irradiation

    International Nuclear Information System (INIS)

    Verjans, H.L.; Eik-Nes, K.B.

    1976-01-01

    Testes of adult, male rats were exposed to a total dose of 1500 R of X-irradiation. Testicular weight decreased from day 8 after X-ray treatment. This decrease was, however, precded by an increment of the testis weight on day 4 following treatment. X-ray treatment of testes was associated with significant increase in serum FSH. Testicular irradiation had, however, no effect on ventral prostate and seminal vesicles weights. Serum testosterone increased only on day 1, 2 and 4 after irradiation, while serum LH levels tended to increase from day 8 post-irradiation. These changes were not significant, however, when compared with non-irradiated controls. At 7, 13 and 20 days following 1500 R of bilateral, testicular X-irradiation, the hypothalamic-pituitary unit was still capable of responding to exogenous gonadotrophin releasing factor. Serum FSH may in male rats be regulated at least partly by circulating steroids of testicular origin and partly by an unknown factor of non-interstitial cell nature. (author)

  3. 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.)

  4. The development of the cholinergic system in rat hippocampus following postnatal X-irradiation

    International Nuclear Information System (INIS)

    Ben-Barak, J.

    1981-01-01

    Postnatal X-irradiation of the rat hippocampus results in a marked reduction in the number of the postnatally developing granular neurons in the dentate gyrus and also caused a marked increase in the specific activity of acetylcholinesterase (AChE) and choline acetyltransferase (CAT) and a slight but consistent increase in the activity per whole hippocampus of AChE. The effect of irradiation on the granular neurons and on the cholinergic enzymes was found to be dose and age dependent. Drastic increase in specific enzymatic activities is also observed in the irradiated cerebellum whose granular neurons differentiate postnatally and to a lesser extent in the cerebral cortex in which cell formation is accomplished prior to birth. (Auth.)

  5. The effect of the timing of prenatal exposure to x-irradiation on Purkinje cell numbers in rat cerebellum

    International Nuclear Information System (INIS)

    Miki, T.; Satriotomo, I.; Matsumoto, Y.; Kuma, H.; Takeuchi, Y.; Gu

    2003-01-01

    Full text: Prenatal exposure of the developing brain to X-irradiation is known to cause various deleterious consequences. We have examined the effects of prenatal X-irradiation on the development of the cerebellum. Wistar rats were exposed to 1.5 Gy X-irradiation either on the 14, 15 or 16th day of gestation (E14, E15, E16). Sham-irradiated animals were used as controls. At seven postnatal weeks of age, male rats were deeply anesthetized and killed by intracardiac perfusion with 2.5 % glutaraldehyde in 0.1 M phosphate buffer. The unbiased stereological procedure known as the fractionator method was used to estimate the total number of Purkinje cells in the cerebellum. Body and cerebellar weights from E14 and E15, but not E16 irradiated rats showed significant deficits compared to control animals. Rats irradiated on E16 and control rats had about 285,100 - 304,800 Purkinje cells in the cerebellum. There was no significant difference between these values. However, E14 and E15 irradiated animals had about 117,500 and 196,300 Purkinje cells, respectively. These estimates were significantly different from those observed in both control and E16 irradiated rats. Given that the phase of division of Purkinje cell progenitors is mainly between E14-E15 and the phase of differentiation and migration is between E16-E20, it is concluded that the vulnerable period of the Purkinje cells to X-irradiation closely overlaps the phase of division of progenitors

  6. Hormonal levels after ovarian X-irradiation of ewes

    International Nuclear Information System (INIS)

    Driancourt, M.A.; Blanc, M.R.; Mariana, J.C.

    1983-01-01

    The effects of X-irradiation on ovulation rate, cyclicity and progesterone and FSH levels in Ile-de-France ewes (4 control and 16 irradiated) after they were treated during the breeding season were reported. The doses used (800 and 2400 R) destroyed 50% of all size classes of the follicular population. Ovulation occurred in 87% of the treated ewes (ovulation rate = 1) when they were irradiated 24 h after luteolysis; 78% of the corpora lutea resulting from these ovulations were normal as to length and progesterone production. FSH in treated ewes started to increase 20 h after treatment and remained higher than in the controls until ovulation time. Later, while these levels were similar between groups on the day of ovulation, high ovulatory levels persisted in irradiated ewes. In the next cycles, the length of the follicular phases, ovulation rate and progesterone and FSH levels were similar between groups

  7. Radiosensitizers: rationale and potential

    International Nuclear Information System (INIS)

    Brown, J.M.

    1981-01-01

    This paper briefly reviews agents that are capable of sensitizing hypoxic cells to radiation and chemotherapeutic agents. The first part is a synopsis of the development of hypoxic radiosensitizers, which concludes that misonidazole can be effective against human tumors. Unfortunately, neurotoxicity limits its effectiveness in humans because the dose that can be given in conjunction with daily fractionated radiation is five to ten times lower than is required for full radiosensitization of the hypoxic cells. The second part covers our recent efforts to develop a drug that does not produce such limiting neurotoxicity. The primary rationale of our program was to synthesize a drug with a short plasma half-life that was too hydrophilic to cross the blood-brain barrier but was able to penetrate tumors and radiosensitize hypoxic cells. From this program, a new drug, SR-2508, has been found that is as efficient as misonidazole in its radiosensitizing ability, but is four to ten times less toxic. Finally, the potential of radiosensitizers not only as agents that can sensitize tumor cells to radiation, but also as agents that can specifically sensitize tumors to chemotherapeutic agents, is discussed. In addition, these drugs may be potential cytotoxic agents that produce toxicity only in solid tumors

  8. Cytogenetic characteristics of soft wheat mutants under x-irradiation

    International Nuclear Information System (INIS)

    Shakaryan, Zh.O.; Avakyan, V.A.; Amirbekyan, V.A.

    1981-01-01

    Radiosensitivity of induced mutants of soft wheat is studied by criteria of frequency and character of changes in 1 and 2 divisions of meiosis. Two constant induced mutant forms of soft wheat were investigated. Mutant lines of squareheads with red ear (re) and erectoids 37/1 were obtained by X-ray irradiating hydride seeds F 1 of hybride combination of Alty-Agach Awnless 1. Seeds of mutants and initial kinds were exposed to X-rays at a dose of 10 kR. A conclusion may be drawn on the basis of studying the meiosis process in mutants and initial kinds of soft wheat on X-ray radiation that the mutants are more radiosensitive. This testifies to that that the induced mutants of soft wheat represent new genotypes in comparison with the initial kinds and differ from the latter not only in morphological characters but in the reaction norm with respect to external medium factors, i.e. the limit of possible changeability of the genotype has been extended [ru

  9. Morphological and behavioral evaluation of central nervous system toxicity after embryonic x-irradiation

    International Nuclear Information System (INIS)

    Schneider, B.F.

    1979-01-01

    The purpose of these studies was to quantify the effects of embryonic x-irradiation on neuronal development and to describe the behavioral effects of such a treatment. Rats were exposed to 125r x-irradiation on gestational day 15

  10. Effect of X-irradiation on the growth and some antioxidase activity in wheat seedlings

    International Nuclear Information System (INIS)

    Li Qun; Gu Ruiqi

    1997-01-01

    Wheat seedlings of 48h after germination were irradiated with various dosage of X-rays. High dosage X-irradiation, 8 Gy and 14 Gy can inhibited the growth, decrease the freshness weight of wheat seedlings. The height and weight of wheat seedlings decreased with the development of X-irradiation of dosage. The concentration of protein and activity of some antioxidases include ascorbic acid peroxidase (ASA-POD), glutathione peroxidase (GSH-Px) and glutathione transferase (GSH-Ts) were observed on 2nd and 4th day after irradiation. The concentration of protein in wheat seedlings decreases with the development of X-irradiation of dosage. The concentration of protein on 4th day was higher than that on 2nd day showed that the damage of wheat seedlings induced by X-irradiation was resumed during the culture process. X-irradiation can increase activity of ASA-POD, GSH-Px and GSH-Ts of wheat seedlings, and the increase rate of 14 Gy X-irradiation was higher than that of 8 Gy. The activity of ASA-POD and GSH-Px increased during the culture process and the activity of GSH-Ts decreased. That's show that wheat seedlings can increase the activity of antioxidases to resist the damage induced by high dosage X-irradiation. The results of low dosage X-irradiation, 2 Gy is similar as the control

  11. Histological aspects of arterial abnormalities produced by X-irradiation of the aortic and branchial arches in the chick embryo

    International Nuclear Information System (INIS)

    Fischer, J.-L.

    1976-01-01

    Low dose X irradiations centred on one or two aortic and branchial arches of 3-day chick embryos result in teratogenic effects on the arteries (21-92%) and in low mortality (4-12%). Histological studies of abnormal arteries show different structural malformations of the arterial wall: inorganized arterial fibres, abnormal intima, newly formed arterial tissue in arterial lumen, coalescence of two arteries. It is suggested that a disturbance at the aortic differentiation level results under experimental conditions in the observed arterial abnormalities

  12. Radiosensitivity in plants

    International Nuclear Information System (INIS)

    Nauman, A.F.

    1979-01-01

    The report presents a compilation of available data on the sensitivity of plants to ionizing radiation, and provides basic information on methods of determining such sensitivities, or of estimating radiosensitivities by calcuation of the nuclear factors upon which they depend. The scope of the data presented here is necessarily limited to the most generally useful radiobiological end points and to the most commonly-used types of radiation. Many of the factors which influence radiosensitivity, particularly nuclear factors, will be discussed. Emphasis will be upon whole-plant studies done at Brookhaven National Laboratory by A.H. Sparrow and his associates, since these studies are the source of most of the available radiosensitivity data and of all the sensitivity predictions listed here. Data presented here include summaries of experimentally-determined radiosensitivities at various end points for both herbaceous and woody higher plants, and for a few species of ferns and lower plants. The algae and fungi have not been considered here due to space limitations

  13. Radiosensitivity in plants

    Energy Technology Data Exchange (ETDEWEB)

    Nauman, A F

    1979-01-01

    The report presents a compilation of available data on the sensitivity of plants to ionizing radiation, and provides basic information on methods of determining such sensitivities, or of estimating radiosensitivities by calcuation of the nuclear factors upon which they depend. The scope of the data presented here is necessarily limited to the most generally useful radiobiological end points and to the most commonly-used types of radiation. Many of the factors which influence radiosensitivity, particularly nuclear factors, will be discussed. Emphasis will be upon whole-plant studies done at Brookhaven National Laboratory by A.H. Sparrow and his associates, since these studies are the source of most of the available radiosensitivity data and of all the sensitivity predictions listed here. Data presented here include summaries of experimentally-determined radiosensitivities at various end points for both herbaceous and woody higher plants, and for a few species of ferns and lower plants. The algae and fungi have not been considered here due to space limitations.

  14. Use of /sup 59/Fe uptake in estimating the marrow dose in normal and splenectomized rats exposed to 1000 kVp x irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Maillie, H D; Baxter, R C; Lisman, H [Rochester Univ., N.Y. (USA). School of Medicine and Dentistry

    1977-11-01

    The /sup 59/Fe uptake system was used to estimate the dose distribution throughout sham-operated and splenectomized rats exposed to whole-body 1000 kVp x irradiation. The marrow in the splenectomized animals was found to be slightly more radiosensitive. However, the difference between the two groups of rats was not significant. The dose distributions throughout the marrow of both groups were the same. It was concluded that splenectomy had no effect on the usefulness of this method. The method of measuring /sup 59/Fe uptake in this study used the uptake of radioiron at 6 hr post-injection and the deduction of the activity due to circulating iron. This resulted in a technique capable of measuring changes in iron uptake with midline-air-exposures of 25 R.

  15. Repair of membrane damage in X-irradiated E. coli

    International Nuclear Information System (INIS)

    Gillies, N.E.; Ratnajothi, N.H.; Hewamanna, R.; Obioha, F.I.

    1984-01-01

    When E. coli B/r or E. coli K12 AB1157 were X-irradiated in the presence of oxygen and incubated immediately after irradiation in broth containing penicillin in concentration that on its own was not lethal to unirradiated bacteria, substantial additional killing was caused. When treatment with penicillin was delayed for increasing times after irradiation the additional killing became progressively less. These results were interpreted as demonstrating the repair or removal of oxygen-dependent radiation-induced lesions in the bacterial membranes. Removal of these lesions was inhibited by incubation of the irradiated bacteria at low temperature before treatment with penicillin or by exposing the cells to a non-lethal concentration of toluene before irradiation. These observations suggest that an enzymatic repair process may be involved in the removal of the membrane lesions. The fatty acid mutant E. coli K 1060 proved exceptional in that some additional killing by penicillin was detectable after anaerobic as well as aerobic irradiation. This points to the importance of membrane composition in the development of those radiation lesions that are brought to light by penicillin treatment. (author)

  16. Production measurements affected by x irradiation of chicken semen

    International Nuclear Information System (INIS)

    Zartman, D.L.; Urquhart, N.S.; Francis, D.W.

    1976-01-01

    Single Comb White Leghorn (S.C.W.L.) and Dark Cornish semen was x-irradiated with 1000 R and introduced into S.C.W.L. hens to produce S.C.W.L. and crossbred chicks. The irradiation reduced the fertilizing capacity of the semen about 25% and the hatchability of the embryos about 38%. Semen of the two breeds was affected differently since there was much less alteration of embryonic development among purebred, S.C.W.L. chicks than among Cornish-sired crossbreds. As is typical, crossbred chicks gained weight faster than purebred S.C.W.L. irrespective of radiation damage. After irradiation, live weight was 4% less at 16 weeks of age for the crossbreds but no substantial effect on growth was evident for the S.C.W.L., although they were significantly heavier at hatching in the irradiated population. The rate of egg production in the first 30 days declined 15% under pressure from the irradiation damage. The distribution, as well as the frequency, of embryonic mortalities changed after parental semen irradiation. The majority of embryonic deaths occurred during the first 6 days of incubation with a coincidental decrease in the proportion of deaths occurring late during incubation. Posthatching mortalities were not affected for S.C.W.L. but were doubled for Cornish up to 16 weeks old

  17. Late effects of x-irradiation in rats, 1

    International Nuclear Information System (INIS)

    Jankovic-Stejin, V.D.; Kanazir, D.T.

    1978-01-01

    The present cytogenetic study was made on the bone marrow cells of 48 male rats killed after 9 to 17 months following acute whole-body x-irradiation. We found that exposure to a dose of 700 rads of x-rays, delivered to animals at a high dose-rate (100 rads/min) resulted in a widespread karyotype variability. The number of cell types were existing independently in the haemopoietic tissue within the first week after irradiation, decreased with time. The selection process of persisting abnormalities as well a further evolution of the cells with new karyotypes to clones, were evident after a month following irradiation. Consequently, the analysis of haemopoietic tissue revealed, in 92% of the late survivors, a genetically heterogeneous cell population in which the number of normal diploid cells decreased to a considerable extent. Clones increased in size with elapsing time from exposure to radiation. Thus, the mean clone cell frequency for animals killed after 9 to 17 months following irradiation ranged from 20.6 +- 3.42% to 61.6 +- 4.26%. Analysis of the data showed a significant positive correlation between development of clones in vivo and the survival time after irradiation (r = 0.820; P<0.01). For such a finding, the occurrence of large clones especially in the bone marrow of rats with growing tumors was of the great influence. Relationship between the degree of mutagenesis on the chromosome level and the process of tumor advancement is discussed. (auth.)

  18. Renal effects of renal x irradiation and induced autoallergic glomerulonephritis

    International Nuclear Information System (INIS)

    Rappaport, D.S.

    1977-01-01

    This study was conducted to determine what, if any, influence a single large x-ray exposure of kidney has on the development and course of an experimental autoallergic glomerulonephritis (EAG) in rats. The EAG was induced by immunization with B. pertussis vaccine and homogenate of homologous kidney tissue and Freund's complete adjuvant. Rats were either immunized, sham-immunized, irradiated (1500 R to right kidney temporarily exteriorized), sham-irradiated, or both immunized and irradiated. Immunized-irradiated animals were irradiated either 4 or 2 weeks prior to, concurrently with, or 1 or 2 weeks after immunization, and were sacrificed at 2, 4, 6, 10, or 14 weeks post-immunization. Immunized-only and sham-immunized-only animals were sacrificed at corresponding post-immunization times, and irradiated-only and sham-irradiated-only animals were sacrificed at corresponding post-irradiation times. Progressive arteriolonephrosclerosis (ANA) was observed in right (irradiated) kidneys following x irradiation. The experimental autoallergic glomerulonephritis (EAG) was observed in both kidneys following immunization. The histopathological changes associated with EAG were distinct from those associated with ANS

  19. Hippocampal development in the rat: cytogenesis and morphogenesis examined with autoradiography and low-level x-irradiation

    International Nuclear Information System (INIS)

    Bayer, S.A.; Altman, J.

    1974-01-01

    The cytogenesis and morphogenesis of the rat hippocampus was examined with the techniques of 3 H-thymidine autoradiography, cell pyknosis produced by low-level x-irradiation, and quantitative histology. The procedure of progressively delayed cumulative labelling was used for autoradiography. Groups of rats were injected with four successive daily doses of 3 H-thymidine during non-overlapping periods ranging from birth to day 19. They were killed at 60 days of age, and the percentage of labelled cells was determined. Cell pyknosis in Ammon's horn reaches a maximal level prenatally and declines rapidly during the early postnatal period. Cell pyknosis in the dentate gyrus reaches its highest level during the second postnatal week and declines gradually with some radiosensitive cells still present in the adult. Immature granule cells are also at their highest level during the second postnatal week, while mature granule cells gradually accumulate to attain asymptotic levels at around two months of age. The alignment of the pyramidal cells to form the characteristic curvature of Ammon's horn occurs shortly after pyramidal cell cytogenesis is completed. Mechanisms for the morphological development of the dentate gyrus along with a consideration of the possible migratory route of granule cell precursors are discussed. (U.S.)

  20. Stage specificity and dose-response relationships for chromosome aberrations induced in mouse primary spermatocytes following X-irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Matsuda, Y.; Tobari, I.; Utsugi, T.

    1986-05-01

    In this study, dose-response relationships were examined for chromosome aberrations observed at diakinesis-metaphase I of spermatocytes with X-irradiation at various stages of meiosis (diplotene, mid-pachytene, zygotene and leptotene). The frequencies of cells with X-ray-induced chromosome aberrations increased with dose at all stages in the applied range of 0.5-3.0 Gy and tended to increase as the irradiated stages descended after leptotene stage. In three stages, the frequencies increased exponentially with dose, but the rates of induction of chromosome breaks were markedly different depending on the stages at which spermatocytes were irradiated with X-rays. The rate of induction was the highest at diplotene and the lowest at leptotene, suggesting that diplotene spermatocytes had the highest radiosensitivity to the induction of chromosome breaks, followed by pachytene, zygotene and leptotene spermatocytes in that order. The dose-response relationships fitted well to linear equations for deletion-type aberrations at each stage, and to linear-quadratic equations for exchange-type aberrations at all stages except for leptotene. At leptotene, the chromatid exchanges were hardly observed, the aberrations being mainly consisted of iso-chromatid fragments. On the contrary, chromatid exchanges and iso-chromatide deletions were mainly observed at later stages (zygotene-diplotene).

  1. HLA‐G modulates the radiosensitivity of human neoplastic cells

    International Nuclear Information System (INIS)

    Michelin, Severino; Gallegos, Cristina; Baffa Trasci, Sofía; Dubner, Diana; Favier, B.; Carosella, E.D.

    2011-01-01

    Tumor cells show a very broad range of radiosensitivities. The differential radiosensitivity may depend on many factors, being the efficiency to recognize and/or repair the DNA lesion, and the cell cycle control mechanisms, the most important (Jeggo and Lavin, 2009; Kumala et al., 2003). Human leukocyte antigen‐G (HLA‐G) is a non‐classical HLA class I molecule involved in fetus protection form the maternal immune system, transplant tolerance, and viral and tumoral immune escape (Carosella et al., 2008). It has been determined that gamma radiation modulates HLA‐G expression at the plasma membrane of human melanoma cells. However, its role in tumoral radiosensitivity has not been demonstrated yet. The objective of this work was to determine if the radiosensitivity of human neoplastic cell lines cultured in vitro was mediated by HLA‐G expression. (authors)

  2. Cellular radiation effects and hyperthermia cell cycle kinetics of radiation sensitive mutants of saccharomyces cerevisiae after x-irradiation and hyperthermia

    International Nuclear Information System (INIS)

    Fingerhut, R.; Kiefer, J.; Otto, F.

    1983-01-01

    Radiosensitive mutants rad2, rad9, and rad51 of Saccharomyces cerevisiae were X-irradiated with 120 Gy or 60 Gy, heated at 50 0 C for 30 min or treated with a combination of both and incubated in nutrient medium at 30 0 C. Cell number, percentage of budding cells, and cell cycle progression were determined in 45-min intervals. Cell cycle kinetics were investigated by flow cytofluorometry. Hyperthermia leads mainly to a lengthening of G1, whereas X-rays arrest cells of the rad2 and rad9 mutant in G2 and the rad51 - mutant additionaly in a state with DNA contents above G2. Cell division dealy is influenced by oxygen in all strains but to a lesser extent in the rad2 mutant. The effect of the combined treatment appears to be merely additive in the rad2 and rad9 mutant while the rad51 mutant is sensitized to X-irradiation by hyperthermia. No selective action of hyperthermia on hypoxic cells was found. (orig.)

  3. Free amino acids in synaptic vesicles isolated from the cerebellum and cerebral hemispheres of control and neonatally X-irradiated rats

    International Nuclear Information System (INIS)

    Valcana, T.; Hudson, D.B.; Timiras, P.S.

    1984-01-01

    X-irradiation of the rat brain (1000R, at two days of age), suppresses the normal age-related increase in the weight of the cerebellum and cerebral hemispheres and influences amino acid levels. The decrease in glutamic acid concentration, particularly in the cerebellum, supports the previously advanced proposition that this amino acid may be associated with or may be the transmitter of, the rat cerebellar granule cells. Subfractionation of the cerebellar tissue reveals that the decrease in the glutamic acid level consequent to the loss of granule cells, is reflected in the cytoplasmic fraction but not in the synaptic vesicle subfraction, where glutamic acid was increased. The reduced weight gain in the cerebral hemispheres after irradiation, is accompanied by a significant decrease of aspartate in the cytoplasmic fraction, changes which suggest that a specific cell type, with aspartic acid as its neurotransmitter (possibly in the hippocampus), may also be radiosensitive in the early postnatal period. In contrast, in the synaptic vesicle fraction from cerebral hemispheres, all free amino acids, with the exception of glutamine, increased significantly. Overall, the changes in free amino acid concentration induced by X-irradiation in the cytoplasmic fraction in both brain regions studied are opposite to those found in the synaptic vesicle fraction and although they may indicate changes in specific cell populations, as proposed above, they could also reflect changes in cellular compartmentalization and metabolism or changes in the relative axonal arborization of the affected regions

  4. Low-Dose Radiation Cataract and Genetic Determinants of Radiosensitivity

    Energy Technology Data Exchange (ETDEWEB)

    Kleiman, Norman Jay [Columbia University

    2013-11-30

    The lens of the eye is one of the most radiosensitive tissues in the body. Ocular ionizing radiation exposure results in characteristic, dose related, progressive lens changes leading to cataract formation. While initial, early stages of lens opacification may not cause visual disability, the severity of such changes progressively increases with dose until vision is impaired and cataract extraction surgery may be required. Because of the transparency of the eye, radiation induced lens changes can easily be followed non-invasively over time. Thus, the lens provides a unique model system in which to study the effects of low dose ionizing radiation exposure in a complex, highly organized tissue. Despite this observation, considerable uncertainties remain surrounding the relationship between dose and risk of developing radiation cataract. For example, a growing number of human epidemiological findings suggest significant risk among various groups of occupationally and accidentally exposed individuals and confidence intervals that include zero dose. Nevertheless, questions remain concerning the relationship between lens opacities, visual disability, clinical cataract, threshold dose and/or the role of genetics in determining radiosensitivity. Experimentally, the response of the rodent eye to radiation is quite similar to that in humans and thus animal studies are well suited to examine the relationship between radiation exposure, genetic determinants of radiosensitivity and cataractogenesis. The current work has expanded our knowledge of the low-dose effects of X-irradiation or high-LET heavy ion exposure on timing and progression of radiation cataract and has provided new information on the genetic, molecular, biochemical and cell biological features which contribute to this pathology. Furthermore, findings have indicated that single and/or multiple haploinsufficiency for various genes involved in DNA repair and cell cycle checkpoint control, such as Atm, Brca1 or Rad9

  5. 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

  6. The anti-tumor effect of ACNU and x-irradiation on mouse glioma

    International Nuclear Information System (INIS)

    Nakagawa, Hidemitsu; Hori, Masaharu; Hasegawa, Hiroshi; Mogami, Heitaro; Hayakawa, Toru.

    1979-01-01

    Anti-tumor activities of 1-(4-amino-2-methyl-5-pyrimidinyl)methyl-3-(2-chloroethyl)-3-nitrosourea hydrochloride (ACNU) and x-irradiation on methylcholanthrene induced glioma in C 57 BL mice were studied in vitro and in vivo. In vitro experiments using cultured glioma cells (MGB cells), the synchronization of cell cycle was done by excess addition of thymidine, and the anti-tumor cell effect were investigated by mean of determinations of DNA synthesis, mitotic index and the number of the living cells following the treatments. As the results, it appeared obvious that ACNU was most effective on MGB cells in S phase and x-irradiation in M phase. As to the combined therapy of ACNU and x-irradiation, the anti-tumor effect was most remarkable when the cells were treated by x-irradiation in the G 2 , M phase, which were hervested by addition of ACNU 44 hours before irradiation. However simultaneous treatment of ACNU and x-irradiation on the cells in G 1 phase was not so remarkable. In vivo experiments the anti-tumor effect of ACNU and x-irradiation on subcutaneously or intracranially transplanted glioma in mice was investigated. Either ACNU 10 mg/kg or local x-irradiation 1240 rads showed inhibitory effect on the tumor growth and prolonged the survival time of the tumor bearing mice. The combination therapy was more effective than ACNU or x-irradiation alone, particularly combination therapy of ACNU and repeated small doses irradiation of x-ray was remarkably effective. Evidence obtained indicated that the combination therapy of ACNU and x-irradiation have synergistic anti-tumor effect on experimental mouse glioma. (author)

  7. Hypoxic cell radiosensitization by moderate hyperthermia and glucose deprivation

    International Nuclear Information System (INIS)

    Kim, J.H.; Kim, S.H.; Hahn, E.W.

    1983-01-01

    Cell culture studies were carried out to determine whether moderate hyperthermia reduces the oxygen enhancement ratio of cells under well-defined cultural conditions. Using asynchronously growing HeLa cells, the OER of cells with and without glucose was determined following exposure of cells to moderate hyperthermia, 40.5omicronC for 1 hr, immediately after X irradiation. The OER of cells with 5 mM glucose was 3.2, whereas the OER of glucose-deprived cells was reduced to 2.0. The pH of the cell culture medium was kept at 7.4 throughtout the experiments. The present finding may provide a clue toward further enhancing the radiosensitization of hypoxic cells by heat

  8. Hypoxic cell radiosensitization by moderate hyperthermia and glucose deprivation

    International Nuclear Information System (INIS)

    Kim, J.H.; Kim, S.H.; Hahn, E.W.

    1983-01-01

    Cell culture studies were carried out to determine whether moderate hyperthermia reduces the oxygen enhancement ratio of cells under well-defined cultural conditions. Using asynchronously growing HeLa cells, the OER of cells with and without glucose was determined following exposure of cells to moderate hyperthermia, 40.5 degrees C for 1 hr, immediately after X irradiation. The OER of cells with 5 mM glucose was 3.2, whereas the OER of glucose-deprived cells was reduced to 2.0. The pH of the cell culture medium was kept at 7.4 throughout the experiments. The present finding may provide a clue toward further enhancing the radiosensitization of hypoxic cells by heat

  9. Intestinal complications following accelerated fractionated X-irradiation

    International Nuclear Information System (INIS)

    Hauer-Jensen, M.; Poulakos, L.; Osborne, J.W.

    1990-01-01

    Due to paucity of suitable animal models, it has been difficult to study the development of long-term intestinal complications following fractionated irradiation. We recently developed a model which allows multiple radiation exposures of a short segment of rat ileum without the need for repeated surgery. In the present series, this model was used to study the influence of shortening the total treatment time (accelerated fractionation) on development of radiation enteropathy. Male rats were orchiectomized and a short segment of distal ileum was transposed to the scrotum. Starting 3 weeks after surgery, the scrotum containing the intestinal segment was X-irradiated with 20 fractions of 2.8 Gy (total dose 56 Gy). Two fractionation schedules were compared: one fraction per day (total treatment time 26 days) and 3 fractions per day (total treatment time 7 days). Actuarial survival curves were obtained, and the degree of radiation injury was assessed 2, 8 and 26 weeks after the last radiation exposure using a semiquantitative histopathologic scoring system. There was no mortality from acute radiation injury in either treatment group. All animals of the 1-fraction/day group survived the observation period (26 weeks). In the 3-fraction/day group, there was significant mortality due to intestinal obstruction, and cumulative mortality at 26 weeks was 100%. Radiation injury, as assessed by the histopathologic scoring system, was also more pronounced in this group than in the 1-fraction/day group. We conclude that shortening the total treatment time significantly increases the severity of late intestinal complications. Our data are suggestive of an association between acute mucosal damage and chronic radiation injury of the small intestine. (orig.)

  10. Radiosensitivity of hepatocellular carcinoma

    International Nuclear Information System (INIS)

    Hennequin, C.; Quero, L.; Rivera, S.

    2011-01-01

    The frequency of hepatocellular carcinoma (HCC) is increasing in the western world and the role of radiotherapy is more and more discussed. Classically, hepatocellular carcinoma was considered as a radioresistant tumour: in fact, modern radio-biologic studies, performed on cell lines directly established from patients, showed that hepatocellular carcinoma has the same radiosensitivity than the other epithelial tumours. From clinical studies, its α/β ratio has been estimated to be around 15 Gy. Radiosensitivity of normal hepatic parenchyma is now well evaluated and some accurate NTCP models are available to guide hepatic irradiation. The biology of hepatocellular carcinoma is also better described: the combination of radiotherapy and targeted therapies will be a promising approach in the near future. (authors)

  11. Radiosensitivity of cells

    Energy Technology Data Exchange (ETDEWEB)

    Alexander, P [Radiation Biology Section, Chester Beatty Research Institute, Royal Cancer Hospital, London (United Kingdom)

    1960-07-15

    The mechanism by which radiation kills cells must be investigated with the goal to make possible to devise means to alter the radiosensitivity of cells. The object of our investigation, supported by IAEA, is to try and find the reasons for the variation in sensitivity between different cells. Once we know the reason for the differences in radiosensitivity of different micro-organisms we can begin to look rationally for ways of enhancing the radiation response of the more sensitive organisms. An investigation of this type has implications far beyond food sterilization, as it cannot fail to provide fundamental facts about radiation injury to cells in general. Cancer researchers have looked for many years for means of sensitizing cancer cells to radiation

  12. Radiosensitivity of cells

    International Nuclear Information System (INIS)

    Alexander, P.

    1960-01-01

    The mechanism by which radiation kills cells must be investigated with the goal to make possible to devise means to alter the radiosensitivity of cells. The object of our investigation, supported by IAEA, is to try and find the reasons for the variation in sensitivity between different cells. Once we know the reason for the differences in radiosensitivity of different micro-organisms we can begin to look rationally for ways of enhancing the radiation response of the more sensitive organisms. An investigation of this type has implications far beyond food sterilization, as it cannot fail to provide fundamental facts about radiation injury to cells in general. Cancer researchers have looked for many years for means of sensitizing cancer cells to radiation

  13. Radiosensitivity of human haematopoietic stem/progenitor cells

    International Nuclear Information System (INIS)

    Kato, Kengo; Kashiwakura, Ikuo; Omori, Atsuko

    2013-01-01

    The haematopoietic system is regenerative tissue with a high proliferative potential; therefore, haematopoietic stem cells (HSCs) are sensitive to extracellular oxidative stress caused by radiation and chemotherapeutic agents. An understanding of this issue can help predict haematopoietic recovery from radiation exposure as well as the extent of radiation damage to the haematopoietic system. In the present study, the radiosensitivity of human lineage-committed myeloid haematopoietic stem/progenitor cells (HSPCs), including colony-forming unit–granulocyte macrophage, burst-forming unit–erythroid and colony-forming unit–granulocyte–erythroid–macrophage–megakaryocyte cells, which are contained in adult individual peripheral blood (PB) and fetus/neonate placental/umbilical cord blood (CB), were studied. The PB of 59 healthy individual blood donors and the CB of 42 neonates were investigated in the present study. HSPCs prepared from PB and CB were exposed to 0.5 or 2 Gy x-irradiation. The results showed that large individual differences exist in the surviving fraction of cells. In the case of adult PB, a statistically significant negative correlation was observed between the surviving fraction observed at a dose of 0.5 Gy and the age of the blood donors; however, none of these correlations were observed after 2 Gy x-irradiation. In addition, seasonal and gender variation were observed in the surviving fraction of CB HSPCs. The present results suggest that there are large individual differences in the surviving fraction of HSPCs contained in both adult PB and fetus/neonate CB. In addition, some factors, including the gender, age and season of birth, affect the radiosensitivity of HSPCs, especially with a relatively low-dose exposure. (paper)

  14. Radiosensitivity and genes

    Energy Technology Data Exchange (ETDEWEB)

    Qiyue, Hu; Mingyue, Lun [Suzhou Medical Coll., JS (China)

    1995-07-01

    Reported effects of some oncogenes, tumour suppressor genes and DNA repair genes on sensitivity of cells to ionizing radiation are reviewed. The role of oncogenes in cellular response to irradiation is discussed, especially the extensively studied oncogenes such as the ras gene family. For tumour suppressor genes, mainly the p53, which is increasingly implicated as a gene affecting radiosensitivity, is reviewed. It is considered that there is a cell cycle checkpoint determinant which is postulated to be able to arrest the irradiated cells in G{sub 1} phase to allow them to repair damage before they undergo DNA synthesis. So far there are six DNA repair genes which have been cloned in mammalian cells, but only one, XRCC1, appears to be involved in repair of human X-ray damage. XRCC1 can correct high sisterchromatid exchange levels when transferred into EM{sub 9} cells, but its expression seems to have no correlation with radiosensitivity of human neck and head tumour cells. Radiosensitivity is an intricate issue which may involve many factors. A scheme of cellular reactions after exposure to irradiation is proposed to indicate a possible sequence of events initiated by ionizing radiation.

  15. Radiosensitivity and genes

    International Nuclear Information System (INIS)

    Hu Qiyue; Lun Mingyue

    1995-07-01

    Reported effects of some oncogenes, tumour suppressor genes and DNA repair genes on sensitivity of cells to ionizing radiation are reviewed. The role of oncogenes in cellular response to irradiation is discussed, especially the extensively studied oncogenes such as the ras gene family. For tumour suppressor genes, mainly the p53, which is increasingly implicated as a gene affecting radiosensitivity, is reviewed. It is considered that there is a cell cycle checkpoint determinant which is postulated to be able to arrest the irradiated cells in G 1 phase to allow them to repair damage before they undergo DNA synthesis. So far there are six DNA repair genes which have been cloned in mammalian cells, but only one, XRCC1, appears to be involved in repair of human X-ray damage. XRCC1 can correct high sisterchromatid exchange levels when transferred into EM 9 cells, but its expression seems to have no correlation with radiosensitivity of human neck and head tumour cells. Radiosensitivity is an intricate issue which may involve many factors. A scheme of cellular reactions after exposure to irradiation is proposed to indicate a possible sequence of events initiated by ionizing radiation

  16. Radiosensitivity of amphibia

    Energy Technology Data Exchange (ETDEWEB)

    Muramatsu, S [National Inst. of Radiological Sciences, Chiba (Japan)

    1975-04-01

    Radiosensitivity (semi-lethal dose) and the damages of radiation in the amphibia were studied by /sup 3/H-TdR from the standpoint of cellular kinetics. The cell mitosis cycle of the amphibia required a long time. The functional cell regeneration and the physiological function of the cell were slower than in mice. The reason for the low radiosensitivity of the amphibia was discussed relative to the environmental factor of temperature. Because the amphibia change body temperature according to environmental temperature, the danger of radiation damage, the actual lethal dose and the period of survival were influenced by the environmental temperature. Acute radiation danger to amphibia was essentially the same as the danger to mammalia, both young and old. LD/sub 50/ irradiation effects varied among the species. The cell regeneration, turn over, and the mitosis in the amphibia, were affected by environmental temperature, however, the courses proceeded slower than those of the mammalia. Therefore, the question remains, whether the comparison of the radiosensitivities of amphibia with other classes of animal by LDsub(50/30) irradiation was appropriate.

  17. In vivo and in vitro radiosensitivities ofnewly established mouse ascites tumors

    International Nuclear Information System (INIS)

    Okamoto, M.; Tsuboi, A.; Tsuchiya, T.

    1981-01-01

    The response of two newly established mouse mammary tumors to x irradiation in vitro and in vivo was studied by colony-forming assay in soft agar. Cells irradiated in vivo were more resistant than those irradiated in vitro. The D 0 values for in vitro irradiation were 112 rad at both exponential and stationary phases, while those for in vivo irradiation were 303 rad at exponential phase and 556 rad at stationary phase. This increase in D 0 value, which is greater than the OER, suggests that radiosensitivity in vivo cannot be explained only by hypoxia

  18. Selective survival of β1-adenergic receptors in rat cerebellum following neonatal X-irradiation

    International Nuclear Information System (INIS)

    Minneman, K.P.; Pittman, R.N.; Wolfe, B.B.; Molinoff, P.B.

    1981-01-01

    To investigate the cellular localization of β 1 - and β 2 -adrenergic receptors, the effects of intermittent neonatal X-irradiation focused on the cerebellum were determined on the densities of the two subtypes of β-adrenergic receptor. This treatment destroys the late-maturing cerebellar interneurons including the granule, basket and stellate cells. The total number of β 2 -adrenergic receptors per cerebellum was reduced by 81-83% in 6- and 12-week-old X-irradiated rats. However, the number of β 1 -adrenergic receptors per cerebellum in 6- and 12-week-old X-irradiated rats was not significantly different from that in control animals. The results suggest that β 2 receptors in the rat cerebellum are primarily associated with the small interneurons destroyed by neonatal X-irradiation. The β 1 receptors may be located on a cell population which is unaffected by this treatment, possibly on cerebellar Purkinje cells. (Auth.)

  19. Effects of whole-body x irradiation on the biogenesis of creatine in the rat

    International Nuclear Information System (INIS)

    Thyagarajan, P.; Vakil, U.K.; Sreenivasan, A.

    1977-01-01

    Influences of whole-body x irradiation on various aspects of creatine metabolism have been studied. Exposures to sublethal or lethal doses of x radiation results in excessive urinary excretion as well as higher accumulation of creatine in the skeletal muscle of x-irradiated rats. A sudden fall in CPK activity in muscle with a concomitant rise in serum suggests that changes in serum and tissue CPK activity are of an adaptive nature in rats exposed to sublethal doses of x radiation. In vitro studies on creatine synthesis shows that transaminidase and methyl transferase activities in kidneys and liver, respectively, are decreased on the 5th day in the x-irradiated, are decreased on the 5th day in the x-irradiated rat. However, on the 8th day, the enzyme activities are restored to normal

  20. Potential in a single cancer cell to produce heterogeneous morphology, radiosensitivity and gene expression

    International Nuclear Information System (INIS)

    Ban, Sadayuki; Ishikawa, Ken-ichi; Kawai, Seiko; Koyama-Saegusa, Kumiko; Ishikawa, Atsuko; Imai, Takashi; Shimada, Yutaka; Inazawa, Johji

    2005-01-01

    Morphologically heterogeneous colonies were formed from a cultured cell line (KYSE70) established from one human esophageal carcinoma tissue. Two subclones were separated from a single clone (clone 13) of KYSE70 cells. One subclone (clone 13-3G) formed mainly mounding colonies and the other (clone 13-6G) formed flat, diffusive colonies. X-irradiation stimulated the cells to dedifferentiate from the mounding state to the flat, diffusive state. Clone 13-6G cells were more radiosensitive than the other 3 cell lines. Clustering analysis for gene expression level by oligonucleotide microarray demonstrated that in the radiosensitive clone 13-6G cells, expression of genes involved in cell adhesion was upregulated, but genes involved in the response to DNA damage stimulus were downregulated. The data demonstrated that a single cancer cell had the potential to produce progeny heterogeneous in terms of morphology, radiation sensitivity and gene expression, and irradiation enhanced the dedifferentiation of cancer cells. (author)

  1. Effects of bleomycin and x irradiation on the frequency of chromosomal aberrations in selected connective tissue diseases

    International Nuclear Information System (INIS)

    Burkhardt, W.C. Jr.

    1978-01-01

    Whole blood lymphocytes from 28 patients with selected connective tissue disorders (6 progressive systemic sclerosis (PSS), 6 anti-nuclear antibody positive rheumatoid arthritis, 6 anti-nuclear antibody negative rheumatoid arthritis, 6 systemic lupus erythematosus, and 4 mixed connective tissue disease) and 17 controls matched for sex, age, and race were studied to determine the frequency of spontaneous as well as bleomycin and/or x-irradiation induced chromosomal aberrations. The effects of bleomycin on cultured lymphocytes were tested, but differential susceptibilities to this clastogen were not demonstrated among the disease groups and controls investigated. However, the combined effect of bleomycin and x irradiation were found to be additive in control lymphocytes, nearly additive in PSS, RA+, and SLE cultures, but reduced considerably from the expected additive value in Ra- cultures. This study indicated that peripheral blood lymphocytes from patients with connective tissue disease, as a whole, possess greater frequencies of spontaneous chromosomal aberrations than matched controls and that x rays can produce greater frequencies of chromosomal aberrations in whole blood lymphocytes of PSS patients than in suitably matched control individuals

  2. Kinetics of telencephalic neural cell proliferation during the fetal regeneration period following a single X-irradiation at the late organogenesis stage. Pt. 2

    International Nuclear Information System (INIS)

    Schmahl, W.

    1983-01-01

    Autoradiographic studies were conducted at the cerebral hemispheres of mouse embryos X-irradiated on day 12 of gestation and of normal litter mates during the subsequent developmental period. By counting the percentage of labeled mitoses the generation time, the potential doubling time, the growth fraction, as well as the length of the individuall cell cycle stages of the neuroblast cells were determined. A continuous increase of generation time was found in the normal brains, concomitant with a latero-medial gradient in telencephalic wall differentiation progress. After X-irradiation this normal differentiation pattern still prevails, but with some marked topographical pecularities. The most important finding was a significant lengthening of the generation time at the medially situated rudiments of the ventricular zone and, similarly at the heterotopic cell islets located within the intermediary zone. Concomitant with this effect, which was seen mainly on days 15 and 17 of gestation, there was a marked increase of mitotic time of these special neuroblasts. The latter finding was regarded as a random event only, which has no causal relationship to the pathogenesis of the heterotopic islets or similar overgrowth anomalies after X-irradiation. In spite of the long generation time of these histological pecularities, they make a considerable contribution to the regeneration of the injured telencephalic wall: up to day 15 gestation the heterotopias had a growth fraction of nearly 1.0(=100 %), whereas the percentage of proliferating cells within the orthotopic remainders of the ventricular zone was only 44%. (orig.)

  3. Chromosomes, cancer and radiosensitivity

    International Nuclear Information System (INIS)

    Samouhos, E.

    1983-01-01

    Some specific chromosomal abnormalities are associated with certain cancers. The earliest description of such a specific association is the one of the Philadelphia chromosome and myelogenous leukemia (1960). Other congenital karyotype abnormalities are associated with specific cancers. Examples of these are Down's syndrome with leukemia and Klinefelter's syndrome with male breast cancer. Genetic diseases of increased chromosome breakage, or of defective chromosome repair, are associated with greatly increased cancer incidence. Three such diseases have been recognized: 1) Fanconi's anemia, associated with leukemias and lymphomas, 2) Bloom's syndrome, associated with acute leukemias and lymphosarcoma, and 3) ataxia telangiectasia, associated with Hodgkin's disease, leukemia, and lymphosarcomas. Ten percent of individuals with ataxia telangiectasia will develop one of these neoplasms. Individuals with certain of these syndromes display an unusually high radiosensitivity. Radiation therapy for cancers has been fatal in patients who received as low as 3000 rad. This remarkable radiosensitivity has been quantitated in cell cultures from such cases. Evidence suggests that the apparent sensitivity may reflect subnormal ability to repair radiation damage. The rapid proliferation of information in this field stems from the interdigitation of many disciplines and specialties, including cytogenetics, cell biology, molecular biology, epidemiology, radiobiology, and several others. This paper is intended for clinicians; it presents a structured analytic scheme for correlating and classifying this multidisciplinary information as it becomes available

  4. Radiosensitization by hematocrit manipulation

    International Nuclear Information System (INIS)

    Hirst, D.G.; Hazlehurst, J.L.; Brown, J.M.

    1985-01-01

    The authors show that tumors in mice adapt to anemia in a rather complex manner. Radiosensitivity may be lower, higher or equal to normal depending on when the anemia is induced prior to irradiation. The authors study these changes in radiosensitivity which occur during a period of anemia followed by the restoration of the hematocrit. When mice were made anemic immediately before irradiation, their tumors were very resistant, but the resistance was lost over the following 24 hrs even though the anemia was maintained. If mice which had been anemic for 24 hrs were retransfused to normal levels with red blood cells immediately before irradiation, their tumors were considerably more sensitive than normal. As the interval between retransfusion and irradiation was increased, sensitization was rapidly lost so that by 24 hrs sensitivity was the same as that of control tumors. They attribute this loss of sensitization to rapid tumor growth in response to a restored oxygen supply so that new hypoxic cells are created. The implications of this for the treatment of the anemic patient are discussed

  5. Genetic control of the radiosensitivity of lymphoid cells for antibody formation ability in mice

    International Nuclear Information System (INIS)

    Okumoto, Masaaki; Mori, Nobuko; Esaki, Kozaburo; Imai, Shunsuke; Haga, Satomi; Hilgers, Jo; Takamori, Yasuhiko.

    1994-01-01

    To analyze the genetic basis of the relationship between the radiosensitivity of the immune response and radiation lymphomagenesis, we examined the radiosensitivity of lymphoid cells for antibody formation in BALB/cHeA, STS/A, F 1 hybrids, and their recombinant inbred mouse strains. The decrease in the number of plaque-forming spleen cells in BALB/cHeA mice exposed to 3 Gy X-irradiation was more than tenfold that in STS/A mice. The phenotype of radioresistance was dominant over sensitivity. The coincidence between the strain distribution patterns of the genetic markers and radiosensitivities of antibody formation in the various recombinant inbred strains was in the region with the lgh locus on chromosome 12. There was obvious difference between the patterns in the region containing the lfa locus on chromosome 4 which has been shown to be related to the incidence of radiation-induced lymphomas. These results indicate that the region on chromosome 12 may contain major gene(s) related to radiosensitivity for antibody formation. (author)

  6. Radiosensitization of hypoxic tumor cells by simultaneous administration of hyperthermia and nitroimidazoles

    International Nuclear Information System (INIS)

    Hofer, K.G.; Hofer, M.G.; Ieracitano, J.; McLaughlin, W.H.

    1977-01-01

    The radiation response of oxygenated and hypoxic L1210 leukemia cells subjected to in vivo treatments with hyperthermia and/or chemical radiosensitizers was evaluated with the [ 125 I]iododeoxyuridine prelabeling assay. X irradiation of L1210 cells at body temperatures of 41 0 C or higher resulted in strongly enhanced tumor cell death. The magnitude of this thermal effect increased with increasing temperatures. Hypoxic L1210 cells were particularly sensitive to heat induced enhancement of radiation damage, i.e., the sensitizing effects were more pronounced and occurred at lower temperatures. Chemical radiosensitizers (metronidazole, Ro 7-0582) selectively sensitized hypoxic L1210 populations; fully oxygenated cells were not affected. Considerable radiosensitization was achieved at nontoxic dose levels of the two sensitizers. Experiments designed to determine the degree of radiosensititization as a function of drug dose showed that Ro 7-0582 was consistently more effective than metronidazole in sensitizing hypoxic tumor populations. At the highest drug dose used (3 mg/g body wt) the DMF was 2.2 for metronidazole and 2.8 for Ro 7-0582. Combined administration of hyperthermia and Ro 7-0582 (or metronidazole) produced synergistic potentiation of radiation damage in hypoxic L1210 populations (DMF of 4.2). Under optimal conditions, hypoxic L1210 cells subjected simultaneously to both modes of radiosensitization became more radiosensitive than untreated, fully oxygenated L1210 cells. Experiments on two other tumor lines (BP-8 murine sarcoma and Ehrlich ascites cells) indicate that such synergistic radiosensitization effects are not unique to L1210 cells

  7. Taxonomic and developmental aspects of radiosensitivity

    International Nuclear Information System (INIS)

    Harrison, F.L.; Anderson, S.L.

    1996-11-01

    Considerable information is available on the effects of radioactivity on adult and early life stages of organisms. The preponderance of data is on mortality after a single irradiation with relatively high doses. Unfortunately, because experiments were carried out under different conditions and for different time periods, the validity of comparing the results from different laxonomic groups is questionable. In general, the conclusions are that there is a relationship (1) between radioresistance to high doses of acute radiation and taxonomy of the organism, primitive forms being more radioresistant than complex vertebrates and (2) between radiosensitivity and developmental stage, early life stages being more sensitive than later stages. The first conclusion may be related to the capability of the organism to repopulate cells and to differentiate and redifferentiate them; the second to the rate of cellular division and to the degree of differentiation. In question, however, is the relevance of the responses from high levels of acute radiation to that of the responses to long-term exposure to low levels of radiation, which are ecologically of more interest. Data from studies of the effects of acute and chronic exposure on development of gametes and zygotes indicate that, for some fishes and invertebrates, responses at the cellular and molecular levels show effect levels comparable to those observed in some mammals. Acute doses between 0,05 and 0.5Cy and dose rates between 0.02 to 0.2mCy/h appear to define critical ranges in which detrimental effects on fertility are first observed in a variety of radiosensitive organisms. To better understand inherent radiosensitivity, we need more information on the ability of cells to repopulate and differentiate and to prevent or repair damage to biological critical molecules, such as DNA, because these factors may alter significantly organisms'' responses to radiation

  8. Taxonomic and developmental aspects of radiosensitivity

    Energy Technology Data Exchange (ETDEWEB)

    Harrison, F.L. [Lawrence Livermore National Lab., CA (United States); Anderson, S.L. [Lawrence Berkeley National Lab., CA (United States)

    1996-11-01

    Considerable information is available on the effects of radioactivity on adult and early life stages of organisms. The preponderance of data is on mortality after a single irradiation with relatively high doses. Unfortunately, because experiments were carried out under different conditions and for different time periods, the validity of comparing the results from different laxonomic groups is questionable. In general, the conclusions are that there is a relationship (1) between radioresistance to high doses of acute radiation and taxonomy of the organism, primitive forms being more radioresistant than complex vertebrates and (2) between radiosensitivity and developmental stage, early life stages being more sensitive than later stages. The first conclusion may be related to the capability of the organism to repopulate cells and to differentiate and redifferentiate them; the second to the rate of cellular division and to the degree of differentiation. In question, however, is the relevance of the responses from high levels of acute radiation to that of the responses to long-term exposure to low levels of radiation, which are ecologically of more interest. Data from studies of the effects of acute and chronic exposure on development of gametes and zygotes indicate that, for some fishes and invertebrates, responses at the cellular and molecular levels show effect levels comparable to those observed in some mammals. Acute doses between 0,05 and 0.5Cy and dose rates between 0.02 to 0.2mCy/h appear to define critical ranges in which detrimental effects on fertility are first observed in a variety of radiosensitive organisms. To better understand inherent radiosensitivity, we need more information on the ability of cells to repopulate and differentiate and to prevent or repair damage to biological critical molecules, such as DNA, because these factors may alter significantly organisms` responses to radiation.

  9. Environmental enrichment to alleviate maze performance deficits in rats with microcephaly induced by X-irradiation

    International Nuclear Information System (INIS)

    Shibagaki, M.; Seo, M.; Asano, T.; Kiyono, S.

    1981-01-01

    Pregnant rats received 150 R of X-irradiation on day 17 of gestation. The male offspring were reared under environmentally enriched (EC), standard colony (SC) or impoverished conditions (IC) for 30 days after weaning. Then the Hebb-Williams maze test was carried out. The effects of X-irradiation and environment were both significant in initial, repetitive and total error scores and running time. Further analysis revealed that both EC-SC and EC-IC differences in initial, repetitive and total error scores were significant in X-irradiated animals, whereas only the EC-IC difference in initial and total error scores was significant in sham-irradiated control animals. Total protein, protein/g cortex, total benzodiazepine and muscarine cholinergic receptor bindings, and muscarinic cholinergic receptor binding/mg protein in the cerebral cortex were decreased in X-irradiated groups, compared to controls, but the effect of environment was not significant in these items. The results confirmed that environmental enrichment is a useful tool to alleviate the learning decrements in prenatally X-irradiated microcephalic rats. (author)

  10. Radiosensitivity of neuroblastoma

    International Nuclear Information System (INIS)

    Deacon, J.M.; Wilson, P.; Steel, G.G.

    1985-01-01

    Neuroblastoma is known to be clinically radioresponsive: it is possible to obtain local tumour control with relatively small doses of radiation. The main therapeutic problem, however, is one of metastatic disease, where in spite of modern combination chemotherapy, the prognosis remains poor. Systemic therapy with either drugs or radiation is dose-limited by toxicity to bone marrow stem cells. However, the advent of new technology which enables tumour cells to be removed from infiltrated marrow prior to autologous bone marrow ''rescue'' allows dose escalation, and makes the use of systemic irradiation in the treatment of stage IV disease feasible. The objective of this study was to investigate the radiobiology of neuroblastoma in detail, including intrinsic cellular radiosensitivity, repair capacity, and extrinsic dose-modifying factors which may affect tumour response in vivo. Cells at three levels of organisation were used: single cell suspensions multicellular tumour spheroids; and xenografts grown in immune-suppressed mice

  11. Two types of congenital hydrocephalus induced in rats by X-irradiation in utero: electron microscopic study on the telencephalic wall

    International Nuclear Information System (INIS)

    Takeuchi, I.K.; Murakami, U.

    1979-01-01

    Stage-specific incidences of congenital hydrocephalus induced by X-irradiation of pregnant rats showed a bimodal distribution. At a dose level of 200 R, 100% hydrocephalic offspring were obtained by irradiation at embryonic days 11 and 14. When pregnant rats were subjected to 200 R X-irradiation at embryonic day 11, numerous ventricular cells of the telencephalic wall of the embryo became necrotic during the first 2 hours post-irradiation, but the paraventricular cell-to-cell interconnexions made up of zonulae adhaerentes were less affected. Mitosis took place in the surviving paraventricular surface cells throughout subsequent development. The full-term fetus exhibited little change in the cytoarchitectural arrangement of neural cells and neuropils, although it was only about half the thickness of the untreated control. After 200 R X-irradiation at embryonic day 14, most of the ventricular cells became necrotic within 6 hours. The paraventricular cell-to-cell interconnexions were completely destroyed, and never repaired in subsequent development. Mitosis took place either freely in cell clusters, or in rosettes which formed randomly in the telencephalic wall between 48 and 72 hours post-irradiation. The resulting telencephalic wall of the full-term fetus was also about half the thickness of the control. In the outer part of the tissue, the cortical plate made up of differentiating neuroblasts was hypoplastic, but the inner half was filled with numerous heterotopic masses of pleomorphic cells and bundles of primitive axons. The ependymal layer at the paraventricular surface was never formed. Whether the paraventricular zonulae adhaerentes were destroyed or not by X-irradiation was considered to be an important factor in the determination of the subsequent cytoarchitectural organization of the telencephalic wall. (author)

  12. Effect of whole-body X-irradiation on lysosomal enzymes

    Energy Technology Data Exchange (ETDEWEB)

    D' souza, D W; Vakil, U K; Srinivasan, A [Bhabha Atomic Research Centre, Bombay (India). Biochemistry and Food Technology Div.

    1974-06-01

    Effects of whole-body x irradiation with sublethal dose (400 rad) on three intestinal lysosomal enzymes, namely, arylsulphatase, cathepsin and acid phosphatases, have been studied. They are almost equally distributed throughout the entire small intestine region. X irradiation adversely affects the integrity of lysosomal membranes. ''Free'' and ''total'' lysosomal enzyme activities exhibit maxima on 6th day. These activities return to normal level on 14th day when there is rapid generation of villi, indicating that lysosomal activities correlate with the progression of injury and of repair mechanism after sublethal dose of x irradiation. The increase in total lysosomal activity may be due to its decreased breakdown, since the rate of protein synthesis in intestinal mucosa is reduced. This is evidenced by reduced incorporation of orally fed /sup 14/C leucine into acid insoluble proteins. (auth)

  13. Cerebellar malformations in prenatally x-irradiated rats: quantitative analysis and detailed description

    International Nuclear Information System (INIS)

    Inouye, M.

    1979-01-01

    Pregnant WKA/HoK rats were exposed to 100 R or 200 R x-irradiation on one of gestation days 16 through 21. Offspring were killed at 60 days of age and the cerebellum was examined. The cerebellum of animals exposed to 200 R was slightly reduced in weight but not in width. The observed reduction in the dorsoventral length of the cerebellum was more evident when the x-irradiation was early in gestation. The anterior portions of hemispheres were situated anterior to the culmen in every 200 R group. Histologically, ectopic Purkinje cells in the granule cell layer and white matter appeared following x-irradiation on day 20 or 21, but they were not found following earlier treatment. In the cerebellum of animals exposed to 100 R the reduction in size was mild and the folial abnormalities were rare, but the number of sublobules decreased

  14. Effects of electroacupuncture on leukocytes and plasma protein in the X-irradiated rats

    International Nuclear Information System (INIS)

    Hau, D.M.

    1984-01-01

    The effects of electroacupuncture on leukocytes and plasma protein on the X ray-irradiated rats were investigated in the present study. The results showed that X-irradiation had an evident inhibitory effect on the counts of total leukocytes, lymphocytes and neutrocytes, and the concentration of the total plasma protein, plasma albumin, globulin and alpha- and beta-globulin in X-irradiated rats. The electroacupuncture was able to help the X-irradiated rats to recover the counts of the total leukocyte, lymphocyte and neutrocyte. The electroacupuncture had a helpful tendency to recover the concentration of the total plasma protein, albumin, globulin, and alpha- and beta-globulin in the irradiated rats

  15. Effects of electroacupuncture on leukocytes and plasma protein in the X-irradiated rats

    Energy Technology Data Exchange (ETDEWEB)

    Hau, D.M.

    The effects of electroacupuncture on leukocytes and plasma protein on the X ray-irradiated rats were investigated in the present study. The results showed that X-irradiation had an evident inhibitory effect on the counts of total leukocytes, lymphocytes and neutrocytes, and the concentration of the total plasma protein, plasma albumin, globulin and alpha- and beta-globulin in X-irradiated rats. The electroacupuncture was able to help the X-irradiated rats to recover the counts of the total leukocyte, lymphocyte and neutrocyte. The electroacupuncture had a helpful tendency to recover the concentration of the total plasma protein, albumin, globulin, and alpha- and beta-globulin in the irradiated rats.

  16. Chromosomal radiosensitivity during the G2 cell-cycle period of skin fibroblasts from individuals with familial cancer

    International Nuclear Information System (INIS)

    Parshad, R.; Sanford, K.K.; Jones, G.M.

    1985-01-01

    The authors reported previously that human cells after neoplastic transformation in culture had acquired an increased susceptibility to chromatid damage induced by x-irradiation during the G2 phase of the cell cycle. Evidence suggested that this results from deficient DNA repair during G2 phase. Cells derived from human tumors also showed enhanced G2-phase chromosomal radiosensitivity. Furthermore, skin fibroblasts from individuals with genetic diseases predisposing to a high risk of cancer, including ataxia-telangiectasia, Bloom syndrome, Fanconi anemia, and xeroderma pigmentosum exhibited enhanced G2-phase chromosomal radiosensitivity. The present study shows that apparently normal skin fibroblasts from individuals with familial cancer--i.e., from families with a history of neoplastic disease--also exhibit enhanced G2-phase chromosomal radiosensitivity. This radiosensitivity appears, therefore, to be associated with both a genetic predisposition to cancer and a malignant neoplastic state. Furthermore, enhanced G2-phase chromosomal radiosensitivity may provide the basis for an assay to detect genetic susceptibility to cancer

  17. The molecular basis of radiosensitivity

    International Nuclear Information System (INIS)

    McMillan, T.J.

    1989-01-01

    This paper considers how DNA damage induced by ionising radiation is processed within the cell. The current view of radiobiology is discussed. The author explains the molecular processes that underlie the differences in radiosensitivity

  18. Role of wild-type p53 in apoptotic and non-apoptotic cell death induced by X-irradiation and heat treatment in p53-mutated mouse M10 cells

    International Nuclear Information System (INIS)

    Ito, Atsushi; Nakano, Hisako; Shinohara, Kunio

    2010-01-01

    The sensitizing effects of wild-type p53 on X-ray-induced cell death and on heat-induced apoptosis in M10, a radiosensitive and Trp53 (mouse p53 gene)-mutated lymphoma cell line which dies through necrosis by X-irradiation, were investigated using three M10 derived transfectants with wild-type TP53 (human p53 gene). Cell death was determined by colony formation and/or dye exclusion test, and apoptosis was detected as the changes in nuclear morphology by Giemsa staining. Expression of wild-type p53 protein increased radiosensitivity of cell death as determined by both clonogenic and dye exclusion assays. This increase in radiosensitivity was attributable largely to apoptosis induction in addition to a small enhancement of necrosis. Interestingly neither pathway to cell death was accompanied by caspase-3 activation. On the other hand, heat-induced caspase-3 dependent apoptotic cell death without transfection was further increased by the transfection of wild-type p53. In conclusion, the introduction of wild-type p53 enhanced apoptotic cell death by X-rays or heat via different mechanisms that do or do not activate caspase-3, respectively. In addition, p53 also enhanced the X-ray-induced necrosis in M10 cells. (author)

  19. Stage-specific effects of X-irradiation on Yeast meiosis

    International Nuclear Information System (INIS)

    Thorne, L.W.; Byers, B.

    1993-01-01

    Previous work has shown that cdc 13 causes meiotic arrest of Saccharomyces cerevisiae following DNA replication by a RAD9-dependent mechanism. In the present work, the authors have further investigated the implicit effects of chromosomal lesions on progression through meiosis by exposing yeast cells to X-irradiation at various times during sporulation. They find that exposure of RAD9 cells to X-irradiation early in meiosis prevents sporulation, arresting the cells at a stage prior to premeiotic DNA replication. rad9 meiotic cells are much less responsive to X-irradiation damage, completing sporulation after treatment with doses sufficient to cause arrest of RAD9 strains. These findings thereby reveal a RAD9-dependent checkpoint function in meiosis that is distinct from the G 2 arrest previously shown to result from cdc 13 dysfunction. Analysis of the spores that continued to be produced by either RAD9 or rad9 cultures that were X-irradiated in later stages of sporulation revealed most spores to be viable, even after exposure to radiation doses sufficient to kill most vegetative cells. This finding demonstrates that the lesions induced by X-irradiation at later times fail to trigger the checkpoint function revealed by cdc 13 arrest and suggests that the lesions may be subject to repair by serving as intermediates in the recombination process. Strains mutant for chromosomal synapsis and recombination, and therefore defective in meiotic disjunction, were tested for evidence that X-ray-induced lesions might alleviate inviability by promoting recombination. Enhancement of spore viability when spo 11 (but not hop 1) diploids were X-irradiated during meiosis indicates that induced lesions may partially substitute for SPO 11-dependent functions that are required for the initiation of recombination. 74 refs., 3 figs., 6 tabs

  20. Studies on Drosophila radiosensitive strains

    International Nuclear Information System (INIS)

    Varentsova, E.P.; Zakharov, I.A.

    1976-01-01

    45 of radiosensitive strains of Drosophila melanogaster were isolated by Curly/Lobe technique after EMS treatment of Livadia population males. The lethality of non-Curly late larvae after gamma-irradiation (4000r) characterized radiosensitivity strains. Most of them exhibited higher frequency of the spontaneous dominant lethals (up to 69%). The males of 6 strains were semi-sterile. 5 of these strains exhibited higher frequency of X-chromosome non-disjunction

  1. Activation of human B lymphocytes. 8. Differential radiosensitivity of subpopulations of lymphoid cells involved in the polyclonally-induced PFC responses of peripheral blood B lymphocytes

    Energy Technology Data Exchange (ETDEWEB)

    Fauci, A S; Pratt, K R; Whalen, G [National Inst. of Allergy and Infectious Diseases, Bethesda, MD (USA)

    1978-11-01

    The differential effect of various doses of irradiation on subpopulations of human peripheral blood lymphoid cells involved in the pokeweed mitogen induced PFC response against sheep red blood cells was studied. The plaque forming B cells were quite sensitive to low doses of irradiation with complete suppression of responses at 300 to 500 rad. On the contrary, helper T-cell function was resistant to 2000 rad. Co-culture of irradiated T cells with autologous or allogeneic B cells resulted in marked enhancement of PFC responses consistent with the suppression of naturally occurring suppressor cells with a resulting pure helper effect. Irradiated T-cell-depleted suspensions failed to produce this effect as did heat killed T cells, whereas mitomycin C treated T cells gave effects similar to irradiated T cells. These findings are consistent with a lack of requirement of cell division for a T-cell helper effect and a requirement of mitosis or another irradiation sensitive, mitomycin C sensitive process for a T-suppressor cell effect. These studies have potential relevance in the evaluation of subpopulations of human lymphoid cells involved in antibody production in normal individuals and in disease states.

  2. 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

  3. Time-resolved magnetic field effects in exciplex systems under X-irradiation

    International Nuclear Information System (INIS)

    Anishchik, S.V.; Lavrik, N.L.

    1988-01-01

    The presence of exciplex systems after X-irradiation of pyrene and N,N-diethylaniline in methanol as well as the influence of the applied magnetic field on exciplex fluorescence was registered using a time-resolving method. The experimental results confirmed the hypothesis on exciplex emergence in the system under study. (author)

  4. X-irradiation in the prevention of experimental post-traumatic vitreous proliferations

    International Nuclear Information System (INIS)

    Belkin, M.; Avni, I.; Kessler, E.; Hercberg, A.; Spierer, A.; Treister, G.

    1983-01-01

    The authors created double perforating injuries in both eyes of 22 rabbits. One eye of each animal was given a dose of 600 Rad x-irradiation 24 hours after the injury. The irradiated eyes developed significantly less intraocular proliferation than the non-irradiated eyes. (author)

  5. Differences in heat-induced cell killing as determined in three mammalian cell lines do not correspond with the extent of heat radiosensitization

    International Nuclear Information System (INIS)

    Kampinga, H.H.; Jorritsma, J.B.M.; Burgman, P.; Konings, A.W.T.

    1986-01-01

    Three different cell lines, Ehrlich ascites tumour (EAT) cells, HeLa S 3 cells and LM mouse fibroblasts, were used to investigate whether or not the extent of heat killing (44 0 C) and heat radio-sensitization (44 0 C before 0-6 Gy X-irradiation) are related. Although HeLa cells were the most heat-resistant cell line and showed the least heat radiosensitization, we found that the most heat-sensitive EAT cells (D 0 , EAT = 8.0 min; D 0 , LM = 10.0 min; D 0 , HeLa = 12.5 min) showed less radiosensitization than the more heat-resistant LM fibroblasts (TERsub(HeLa)< TERsub(EAT)< TERsub(LM)). Therefore, it is concluded that the routes leading to heat-induced cell death are not identical to those determining heat radiosensitization. Furthermore the inactivation of DNA polymerase α and β activities by heat seemed not to correlate with heat survival alone but showed a positive relationship to heat radiosensitization. The possibility of these enzymes being a determinant in heat radiosensitization is discussed. (author)

  6. Protective effects of vitamin E on microcephaly in rats X-irradiated in utero: DNA, lipid peroxide and confronting cisternae

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, Harumi; Iwasaki, Setsuo; Inomata, Kenichirou; Nasu, Fumio; Nishimura, Shigeru

    1986-06-01

    Fetuses from rats given either water or 0.03% D,L-..cap alpha..-tocopherol acetate (vitamin E) as a drinking fluid and X-irradiated with 100 rad on gestational day 13 were examined on gestational day 21. Mean cerebral weight which was significantly reduced by the X-irradiation was increased by vitamin E supplementation but the level did not reach that in sham-irradiated controls. Administration of vitamin E caused an increase in DNA concentration which was significantly reduced by X-irradiation with water treatment. An increase in the mean level of lipid peroxide formation was observed in the water-treated, X-irradiated group in the sample at zero time but not in the vitamin E-treated, X-irradiated group. In the cytoplasm of fetal cerebral neurons from X-irradiated dams with vitamin E supplementation, confronting cisternae were frequently observed between two nuclear envelopes. Confronting cisternae may be considered as a repair mechanism of vitamin E against X-irradiated neuronal damage in the fetal cerebrum. This study provides evidence of the protection by vitamin E of neuronal development in X-irradiated fetuses, through its antioxidant properties, against attacks by free radicals and/or lipid peroxide. 35 refs.; 3 figs.; 1 table.

  7. Radiosensitivity of carcinoma of esophagus

    International Nuclear Information System (INIS)

    Furusawa, Hidenori

    1986-01-01

    With a detailed graphic reconstruction of radiation effects shown in 11 operation materials of carcinoma of esophagus with preoperative irradiation, histologic analysis of the radiosensitivity was made. Residual cancer lesions in 11 operation specimens contained adenocarcinoma elements. Carcinoma of esophagus belonged to mixed carcinoma (syn. metaplastic cancer). Radioresistant nature resulted from the remnant adenocarcinoma elements. Protruded type (3 cases) showed about 60 % of residual cancer after preoperative irradiation of 40 Gy (Lineac or 60 Co.). The residual cancer nests histologically revealed well-differentiated squamous cell carcinoma with a few signet-ring cells, compatible with mucoepidermoid carcinoma. In protruded type, the mixed carcinoma was composed of segmental, disproportioned zonal squamous metaplasia. As its histogenetic origin, a main duct of esophageal gland was suggested. In 9 autopsy cases of esophageal cancer, recurrent lesion within the field of irradiation failed to respond to radiotherapy. In recurrent residual lesions, a higher proportion of adenocarcinoma elements was noticed. Therefore, the cancer part formed by a high rate of metaplasia was markedly responsive to irradiation, whereas increased residue of adenocarcinoma elements was enhanced the radioresistant property. In a middle thoracic esophagus (Im) corresponding to the commonest site of esophageal cancer, the distribution of esohageal glands was in a high density with a constant ratio of density in each age group particularly in male. In age groups with higher incidence of carcinoma of esophagus, esophageal glands markedly increased especially in male, in contrast with the indefinite number and density ratio in female cases. A high density of esophageal glands was noticed in the upper (Iu) and lower (Im) parts of the 2nd physiologic constriction, in proportion to the commonest site of carcinoma of esophagus. (J.P.N.)

  8. Development of rat visual system after prenatal X-irradiation

    International Nuclear Information System (INIS)

    Brueckner, G.; Biesold, D.; Mares, V.

    1980-01-01

    Rats pregnant for 16 or 19 days (ED 16 or 19) were irradiated with 1 Gy and killed after 24 hrs or at age 24 or 180 days. The primary influence of X-rays consists in a lethal lesion of cells located in the periventricular zone as well as some of the more differentiated cells in the brain parenchyma. After irradiation on ED 16, the acute damage was greater in the cerebral cortex and the superior colliculus (SC) than in the lateral geniculate nucleus (LGN). Irradiation on ED 19 damaged mainly the cortical part of the visual system. In adult animals the acute radiation damage results in a deficit in packing density and the total number of neurons. Animals irradiated on ED 16 revealed more pronounced changes in deep layers of the cortex (L VI) than in the superficial layers. The deficit was smaller in the SC, and in the LGN an increase in the packing density of nerve cells was found. In animals irradiated on ED 19, the deficit in neurons density occurred mainly in more superficial layers of the cortex, with a maximum deficit in layer IV. From comparison of acute and final changes it may be concluded that the damage of preneuroblastic cell populations is compensated during later embryonic development, while the damage induced in populations already at early neuroblast stage is irreversible and leads to a permanent deficit. Glia cell population is altered in a similar way as the number of neurons in regions poor in myelin, while in regions rich in myelin the number of glia cells seems to depend on changes in the number of efferent and afferent nerve fibres. (author)

  9. Hereditary syndromes with enhanced radiosensitivity

    International Nuclear Information System (INIS)

    Lohmann, D.

    2000-01-01

    Sensitivity to ionizing radiation is modified by heritable genetic factors. This is exemplified by heritable disorders that are characterized by predisposition to the development of neoplasms. Cells derived from patients with ataxia telangiectasia, Nijmegen breakage syndrome and ataxia telangiektasia-like disorder show a markedly changed reaction to exposure to ionizing radiation. Correspondingly, at least in patients with ataxia telangiectasia, an enhanced radiosensitivity that is of clinical importance has been observed. In addition to these recessive disorders, some autosomal dominant cancer predisposition syndromes are associated with increased radiosensitivity. As cells from these patients still have a normal allele (that is dominant over the mutant allele), the cellular phenotype is most often normal. Specifically, there is no overtly altered reaction in response to ionizing radiation. Nevertheless, two dominant cancer predisposition syndromes, namely hereditary retinoblastoma and naevoid basal cell carcinoma syndrome, are associated with a enhanced radiosensitivity as indicated by increased development of tumors following radiation therapy. (orig.) [de

  10. Hormonal status can modify radiosensitivity

    International Nuclear Information System (INIS)

    Ricoul, M.; Sabatier, L.; Dutrillaux, B.

    1997-01-01

    In preliminary experiments, we have demonstrated that pregnancy increases chromosome radiosensitivity in the mouse at the end of gestation. Blood obtained from women at various times of pregnancy was then exposed to ionizing radiations in vitro. By comparison to non pregnant women, an increase in chromosome breakages was observed in metaphases from lymphocytes. Immediately after delivery, this increase of radiosensitivity disappeared. In a prospective study, serial analyses showed a very strong correlation between the amount of pregnancy hormones, progesterone in particular, and the increase of radiosensitivity. Thus, pregnant women may have an increased sensitivity to ionizing radiation during the second half of their pregnancy and the risks of radiation exposure of pregnant women have to be considered not only n relation to the child, but also to their own hypersensitivity. (authors)

  11. The radiosensitivity of spermatogonial stem cells in C3H/101 F1 hybrid mice

    International Nuclear Information System (INIS)

    Van der Meer, Yvonne; De Rooij, Dirk G.; Cattanach, Bruce M.

    1993-01-01

    The radiosensitivity of spermatogonial stem cells of C3H/HeHx101/H F 1 hybrid mice was determined by counting undifferentiated spermatogonia at 10 days after X-irradiation. During the spermatogenic cycle, differences in radiosensitivity were found, which were correlated with the proliferative activity of the spermatogonial stem cells. In stage VIII irr , during quiescence, the spermatogonial stem cells were most radiosensitive with a D 0 of 1.4 Gy. In stages XI irr -V irr , when the cells were proliferatively active, the D 0 was about 2.6 Gy. Based on the D 0 values for sensitive and resistant spermatogonia and on the D 0 for the total population, a ratio of 45:55% of sensitive to resistant spermatogonial stem cells was estimated for cell killing. When the present data were compared with data on translocation induction obtained in mice of the same genotype, a close fit was obtained when the translocation yield (Y; in % abnormal cells) after a radiation dose D was described by Y=e τD , with τ=1 for the sensitive and τ=0.1 for the resistant spermatogonial stem cells, with a maximal e τD of 100

  12. Effects of taurolidine on radiosensitivity of murine melanoma cells and its mechanism

    International Nuclear Information System (INIS)

    Sun Baosheng; Liu Shixin; Wang Tiejun; Liu Linlin; Huang Guomin; Gong Shouliang

    2008-01-01

    Objective: To observe the effects of taurolidine on radiosensitivity of B16-F10 cells of murine melanoma via the enhancement of Bax and Bad proteins and induction of Bcl-2 protein. Methods: The apoptosis of B16-F10 cells was assessed after treated with 0, 10, 25, 50, 100 and 150 μmol·L -1 taurolidine, clone survival assay was used to detect the radiosensitivity of B16-F10 cells, and protein expressions were determined by Western blotting. Results: The apoptosis of 5% cells was induced in a dose-and time-dependent manner after B16-F10 cells were treated with 50 μmol·L -1 taurolidine. The survival rate decreased after treated with tautolidine in combination with 2 Gy X-irradiation with the increase of taurolidine concentration and doses of irradiation (P 0 and SER D q ) also increased with the increase of its concentration, there was significant difference between 50 μmol·L -1 taurolidine group and 10 μmol·L -1 taurolidine group (P<0.05); meantime, the level of proapototic protein Bax and Bad increased and the level of antiapoptotic protein Bcl-2 reduced. Conclusion: Taurolidine in combination with irradiation can enhance the radiosensitivity by the mediation of Bcl-2 family protein. (authors)

  13. Reproductive survival of explanted human tumor cells after exposure to nitrogen mustard or x irradiation; differences in response with subsequent subculture in vitro

    International Nuclear Information System (INIS)

    Wells, J.; Berry, R.J.; Laing, A.H.

    1977-01-01

    Curves for the survival of reproductive capacity of explanted human tumor cells, following exposure to the alkylating agent nitrogen mustard (mustine hydrochloride) or 250-kVp x rays, were obtained as soon as a satisfactory plating efficiency, i.e., greater than or approximately equal to 10 percent, was obtained from the tumor cells in vitro (usually within 2-10 weeks of explanation). It was found that all six tumor explants tested became more sensitive to the action of nitrogen mustard on serial subculture, whereas the response of four explants which were X-irradiated was invariant with further subculturing. Furthermore, all but one explant yielded survival curves which were extremely similar, with D/sub q/ values circa 440-610 rad. One line, from a seminoma, however, had a D/sub q/ of 150 rad. These radiosensitive seminoma cells were, however, the most resistant to the action of nitrogen mustard. The increase in sensitivity to nitrogen mustard with serial subculture in vitro was not associated with any change in the proliferative rate of the cells, although it may be associated with an increase in the efficiency of transport

  14. A study of morphogenesis of digital malformation on rat embryo by x-irradiation

    International Nuclear Information System (INIS)

    Kim, Jhai Dhuck; You, Dong Soo

    1981-01-01

    The author studied in the effects of x-irradiation to the development of digital malformation in gestation rats. The time-matings occurred between 6 p.m. and 8 a.m. and females with copulation plugs at 8 a.m. were isolated and properly marked for evidence of copulation. The lower abdomen of mothers were exposed to x-irradiation on the 11 1/2th day of gestation, the critical period developing digital malformation, respectively 100, 150, 200, 250, 300 and 350 rads. At 18 1/2th day of post-conception total 50 pregnant females were dissected and the incidence of digital malformations were obtained. Rat embryos on the 12, 13, 14, 15, 16th day of gestation irradiated by 250 rads were examined for morphogenesis of digital malformation. Digital radiating lines were examined in water and histologically by H-E stain. Supra vital stain samples by Nile-blue sulfate in 37 .deg. C normal saline were prepared for the observation of cell necrosis regions and morphogenesis of digits. The results obtained were as follows; 1. By x-irradiation on 11th day of gestation, digital malformations of Ectrodactylia, Syndactylia, Polydactylia and Hematodactylia were developed. Ectrodactylia showed the effective relationship to the amount of irradiation, however Syndactylia and Poydactylia did not. 2. By x-irradiation, cell necrosis of digital germ was appeared markedly, but in 48 hours after irradiation was depressed to the periphery of digital germ and in 72 hours after irradiation was disappeared. Digital radiating line showed marked state of malformation in 48 hours after irradiation and continued to show the same amount of physiological cell necrosis as the compared control group in 72 hours after irradiation. But in the Syndactylia, physiological cell necrosis was not able to be recognized. 3. Ectrodactylia induced by x-irradiation was considered as the direct result of cell necrosis of digital origin, however, Polydactylia and Syndactylia were considered as the result of some effect in

  15. Protection of Escherichia coli cells against the lethal effects of ultraviolet and X-irradiation by prior X-irradiation. A genetic and physiological study

    Energy Technology Data Exchange (ETDEWEB)

    Smith, K C; Martignoni, K D [Stanford Univ., Calif. (USA). Dept. of Radiology

    1976-12-01

    When log phase cells of wild-type E.coli K-12 were maintained in growth medium after X-irradiation, they became progressively more resistant to a subsequent exposure to UV or X-radiation. The time to achieve maximum resistance was about 60 min. The uvrB, uvrD, polA and certain exrA strains (W3110 background) also demonstrated this X-ray-induced resistance to subsequent UV or X-irradiation but recA, recB, lex (AB1157 or W3110 backgrounds) and other exrA strains (AB1157 background) did not. The resistance induced in wild-type, uvrB and uvrD cells was characterized by the production or enhancement of a shoulder on the survival curves obtained for the second irradiation, while the resistance induced in the W3110 exrA strains was expressed only as a change in slope. The induction of resistance in the W3110 exrA strain was not inhibited by the presence of chloramphenical, but that in the wild-type cells appeared to be. The production or enhancement of a shoulder on the survival curves of the rec/sup +/ lex/sup +/ exr/sup +/ cells is consistent with the concept of the radiation induction of repair enzymes. Alternative explanations, however, are discussed.

  16. Targeting neuroendocrine differentiation for prostate cancer radiosensitization

    Science.gov (United States)

    2017-12-01

    Fig. 12). Since we suspected that Western blotting-based method may not be sensitive enough, we are planning to use radioisotope -labeled SAM to...Chang-Deng Hu CONTRACTING ORGANIZATION: Purdue University, West Lafayette, IN 47907-2040 REPORT DATE : December 2017 TYPE OF REPORT: Final...RETURN YOUR FORM TO THE ABOVE ADDRESS. 1. REPORT DATE December 2017 2. REPORT TYPE Final 3. DATES COVERED 30 Sept 2013 - 29 Sept 2017 4. TITLE AND

  17. AT-406, an IAP inhibitor, activates apoptosis and induces radiosensitization of normoxic and hypoxic cervical cancer cells.

    Science.gov (United States)

    Lu, Jing; Qin, Qin; Zhan, Liang-Liang; Liu, Jia; Zhu, Hong-Cheng; Yang, Xi; Zhang, Chi; Xu, Li-Ping; Liu, Zhe-Ming; Wang, Di; Cui, He-Qing; Meng, Ciu-Ciu; Cai, Jing; Cheng, Hong-Yan; Sun, Xin-Chen

    2014-01-01

    IAP antagonists increased the antitumor efficacy of X-irradiation in some types of cancers, but their effects on hypoxic cancer cells remain unclarified. We aims to investigate the radiosensitizing effect of an IAP inhibitor AT-406 on cervical cancer cell lines under both normoxia and hypoxia conditions. Hela and Siha cells were treated to investigate the effects of drug administration on cell proliferation, apoptosis, and radiosensitivity. Western blot analysis was used to determine the role of AT-406 in inhibition of IAPs. The pathway of apoptosis was characterized by caspases activity assay. AT-406 potently sensitized Hela cells but not Siha cells to radiation under normoxia. Notably, the radiosensitizing effect of AT-406 on hypoxic cells was more evident than on normoxic cells in both cell lines. Further mechanism studies by western blot showed that under normoxia AT-406 decreased the level of cIAP1 in Hela cells in a dose-dependent manner; while additional downregulation of XIAP expression was induced by AT-406 treatment under hypoxia in both cell lines. Finally, AT-406 works on both extrinsic death receptor and intrinsic mitochondrial apoptosis pathways to activate apoptosis. Totally, AT-406 acts as a strong radiosensitizer in human cervical cancer cells, especially in hypoxic condition.

  18. Individual differences in the radiosensitivity of hematopoietic progenitor cells detected in steady-state human peripheral blood

    International Nuclear Information System (INIS)

    Oriya, Asami; Takahashi, Kenji; Kashiwakura, Ikuo; Inanami, Osamu; Kuwabara, Mikinori; Miura, Toshiaki; Abe, Yoshinao

    2008-01-01

    The aim of this study is to evaluate the individual differences in radiosensitivity of lineage-committed myeloid hematopoietic progenitors, colony-forming cells (CFC), detected in steady-state human peripheral blood (PB). Mononuclear cells were prepared from the buffy-coat of 30 individuals PB, and were assayed for CFC by semi-solid culture supplemented with cytokines. X irradiation was performed in the range of 0.5-4 Gy at a dose rate of about 80 cGy/min. The mean number of hematopoietic progenitor cells is 5866±3408 in 1 ml of buffy-coat, suggesting that the erythroid progenitor cells are the major population. The total CFC radiosensitivity parameter D 0 and n value are 1.18±0.24 and 1.89±0.98, respectively. Using a linear regression analysis, a statistically significant correlation is observed between the D 0 value and the surviving fraction at 4 Gy (r=0.611 p 0 parameter and the level of antioxidants, plasma uric acid, plasma bilirubin, and intracellular glutathione. The present study demonstrates that there are large individual differences in the radiosensitivity of hematopoietic progenitor cells as detected in steady-state human PB. These differences demonstrate almost no correlation with plasma or intracellular antioxidants. The prediction of individual differences in radiosensitivity of CFC can only be measured by 4 Gy irradiation. (author)

  19. Combined effects of x-irradiation and bleomycin on the proliferation of isoproterenol-stimulated mouse parotid glands

    International Nuclear Information System (INIS)

    Shoju, Masumi

    1977-01-01

    Effects of x-irradiation and bleomycin (BLM) on DNA synthesis in isoproterenol (IPR)-stimulated mouse parotid glands were investigated. The incorporation of thymidine- 3 H into DNA in parotid glands increased remarkably in 16 hours with a peak at 22 hours after the injection of IPR. When x-irradiation (250 rads) was given at 1 hour after IPR (early G 1 phase), the stimulation of DNA synthesis was inhibited by about 50%, and the beginning of DNA synthesis was delayed nearly 6 hours. BLM injected in the early G 1 phase was also effective in inhibiting DNA synthesis. However, the injection of BLM in the late G 1 or S phase did not interfere with DNA synthesis. Combined x-irradiation and BLM inhibited DNA synthesis and delayed the beginning of the S phase far more strikingly than did x-irradiation alone. When BLM was injected at various intervals before and after x-irradiation, the greatest inhibition was found just after irradiation. Therefore, a longer interval between x-irradiation and BLM injection had a tendency to decrease the rate of inhibiting DNA synthesis. These findings were confirmed by measuring the labeling index and the mitotic index in the acinar cells of the mouse parotid gland. These results suggest that simultaneous application of x-irradiation and BLM has the greatest effect. (Evans, J.)

  20. Development of novel radiosensitizers for cancer therapy

    CERN Document Server

    Akamatsu, K

    2002-01-01

    The novel radiosensitizers for cancer therapy, which have some atoms with large X-ray absorption cross sections, were synthesized. The chemical and radiation (X-rays, W target, 100kVp) toxicities and the radiosensitivities to LS-180 human colon adenocarcinoma cells were also evaluated. 2,3,4,5,6-pentabromobenzylalcohol (PBBA) derivatives were not radiosensitive even around the maximum concentration. On the other hand, the hydrophilic sodium 2,4,6-triiodobenzoate (STIB) indicated meaningful radiosensitivity to the cells. Moreover, the membrane-specific radiosensitizers, cetyl fluorescein isthiocyanate (cetyl FITC), cetyl eosin isothiocyanate (cetyl br-FITC), cetyl erythrosin isothiocyanate (cetyl I-FITC), which aim for the membrane damage by X-ray photoabsorption on the target atoms, were localized in the plasma membrane. As the results of the colony formation assay, it was found that both cetyl FITC are similarly radiosensitive. In this report, we demonstrate the synthetic methods of the radiosensitizers, the...

  1. Effects of nutritional status on gastric secretion and composition in X-irradiated rat

    International Nuclear Information System (INIS)

    D'Souza, D.W.; Vakil, U.K.; Sreenivasan, A.

    1974-01-01

    Whole body x-irradiation of the rat with a sub-lethal (400 r) or lethal (800 r) dose causes a marked depression in secretion and composition of gastric juice with a maximum drop of the 8th day. Similarly, pepsin and gastricsin activities also decline progressively, being lowest on the 8th day post-irradiation. Radiation exposure of the rat also results in a sudden rise in serum and tissue histamine levels which occurs on the 1st day, and returns to normal on the 3rd day post-irradiation. The nutritional status of the animal appears to influence recovery from radiation injury. Rats fed adequate diets with respect to protein and vitamin A prior to irradiation (400 r) recover earlier from radiation injury than deficient animals. The above biochemical changes are associated with gross and severe degeneration of stomach cells in the x-irradiated rat. (author)

  2. Congenital hydrocephalus following X-irradiation of pregnant rats on an early gestational day

    International Nuclear Information System (INIS)

    Takeuchi, I.K.; Takeuchi, Y.K.

    1986-01-01

    When pregnant rats were X-irradiated at a dose of 100 R on gestational day 9.5, a considerable number of postnatally-viable hydrocephalic offspring resulted, all of which were accompanied with bilateral micro- or anophthalmia. Histological studies revealed that the cerebral aqueduct of the congenital hydrocephalic brain was severely stenosed, and the subcommissural organ was reduced in size and displaced at some distance from the anterior end of the cerebral aqueduct. From embryological studies, it was considered that the maldevelopment of the subcommissural organ in the X-irradiated fetus might cause a reduction in the amount of its secretions which function as a cushion preventing complete closure of the cerebral aqueduct during fetal life, resulting in stenosis of the cerebral aqueduct

  3. 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)

  4. Cartilaginous metaplasia and overgrowth of neurocranium skull after X-irradiation in utero.

    Science.gov (United States)

    Schmahl, W; Meyer, I; Kriegel, H; Tempel, K H

    1979-01-01

    Prenatal X-irradiation of mice in the late organogenesis stage either with a fractionated or a single exposure dose (3 X 160 R or 200 R) leads to remarkable, previously undescribed malformations of the skull. These malformations range from mild hyperostotic nodule formation in about 90% of the offspring to excessive formation of desmal bony tissues, which extend deep into the forebrain and are thus only detectable in histological sections. Metaplastic and hyperplastic formation of cartilage in all the neurocranial regions is observed in about 10% of the offspring. The pathogenesis of these overgrowth phenomena is presumably related to a growth disturbance of both the mesenchymal skull primordium and the brain. While malformation of the latter leads to a decrease of intracranial pressure and consequently to altered growth activity of the skull sutures, the reparative and proliferative capacities of the mesenchyme are also stimulated, in a hyperplastic direction, by X-irradiation.

  5. Repair and replication of DNA in hereditary (bilateral) retinoblastoma cells after X-irradiation

    International Nuclear Information System (INIS)

    Cleaver, J.E.; Char, D.; Charles, W.C.; Rand, N.

    1982-01-01

    Fibroblasts from patients with hereditary retinoblastoma reportedly exhibit increased sensitivity to killing by X-rays. Although some human syndromes with similar or greater hypersensitivity to DNA-damaging agents (e.g., X-rays, ultraviolet light, and chemical carcinogens), such as xeroderma pigmentosum, are deficient in DNA repair, most do not have such clearly demonstrable defects in repair. Retinoblastoma cells appear to be normal in repairing single-strand breaks and performing repair replication after X-irradiation and also in synthesizing poly(adenosine diphosphoribose). Semiconservative DNA replication in these cells, however, is slightly more resistant than normal after X-irradiation, suggesting that continued replication of damaged parental DNA could contribute to the pathogenesis of the disease. This effect is small, however, and may be a consequence rather than a cause of the fundamental enzymatic abnormality in retinoblastoma that causes the tumorigenesis

  6. X-irradiation improves mdx mouse muscle as a model of myofiber loss in DMD

    International Nuclear Information System (INIS)

    Wakeford, S.; Watt, D.J.; Partridge, T.A.

    1991-01-01

    The mdx mouse, although a genetic and biochemical homologue of human Duchenne muscular dystrophy (DMD), presents a comparatively mild histopathological and clinical phenotype. These differences are partially attributable to the greater efficacy of regeneration in the mdx mouse than in DMD muscle. To lessen this disparity, we have used a single dose of X-irradiation (16 Gy) to inhibit regeneration in one leg of mdx mice. The result is an almost complete block of muscle fiber regeneration leading to progressive loss of muscle fibers and their replacement by loose connective tissue. Surviving fibers are mainly peripherally nucleated and, surprisingly, of large diameter. Thus, X-irradiation converts mdx muscle to a model system in which the degenerative process can be studied in isolation from the complicating effect of myofiber regeneration. This system should be of use for testing methods of alleviating the myofiber degeneration which is common to mdx and DMD

  7. X-irradiation improves mdx mouse muscle as a model of myofiber loss in DMD

    Energy Technology Data Exchange (ETDEWEB)

    Wakeford, S.; Watt, D.J.; Partridge, T.A. (Charing Cross and Westminster Medical School, London (England))

    1991-01-01

    The mdx mouse, although a genetic and biochemical homologue of human Duchenne muscular dystrophy (DMD), presents a comparatively mild histopathological and clinical phenotype. These differences are partially attributable to the greater efficacy of regeneration in the mdx mouse than in DMD muscle. To lessen this disparity, we have used a single dose of X-irradiation (16 Gy) to inhibit regeneration in one leg of mdx mice. The result is an almost complete block of muscle fiber regeneration leading to progressive loss of muscle fibers and their replacement by loose connective tissue. Surviving fibers are mainly peripherally nucleated and, surprisingly, of large diameter. Thus, X-irradiation converts mdx muscle to a model system in which the degenerative process can be studied in isolation from the complicating effect of myofiber regeneration. This system should be of use for testing methods of alleviating the myofiber degeneration which is common to mdx and DMD.

  8. Alteration of T cell function in healthy persons with a history of thymic x irradiation

    International Nuclear Information System (INIS)

    Rieger, C.H.L.; Kraft, S.C.; Rothberg, R.M.

    1975-01-01

    The possible late effects of x irradiation to the infantile thymus were investigated by studying immune functions in 12 healthy persons with a history of thymic x irradiation and healthy control subjects. No differences were found in serum immunoglobulin values, humoral antibody levels, lymphocyte counts, and lymphocyte reactivity to phytohemagglutinin, vaccinia virus, purified protein derivative (PPD), and allogeneic cells. The irradiation group exhibited cellular hyperresponsiveness to streptokinase-streptodornase (SK-SD). In contrast, mean skin and in vitro lymphocyte responses to Candida albicans were depressed in the patients with thymic irradiation. A dissociation of these two Candida responses was found in only 1 of 14 healthy control subjects but in 7 of 12 irradiated individuals. While thymic irradiation did not result in impaired immunologic defenses leading to clinical disease, it caused alterations in T cell responses similar to those reported in patients with chronic mucocutaneous candidiasis

  9. Selective elimination of intracortically projecting neurons of the rat neocortex by prenatal x-irradiation

    International Nuclear Information System (INIS)

    Jensen, K.F.

    1981-01-01

    The development of new racing methods has suggested that there are species differences in the extent of the contribution of the different layers of the neocortex to the callosal projection. The present investigation has utilized prenatal x-irradiation to selectively eliminate the late forming neurons of the supragranular layers of the rat neocortex. The reduction in the neuronal population of the supragranular layers closely parallels the reduction in the corpus callosum. These results indicate that the primary source of neurons of the callosal projection, are the late forming neurons of the supragranular layers. Thus, the current results suggest that low dose prenatal x-irradiation may be used to evaluate important developmental events in the formation of neocortical circuitry

  10. Alteration of T cell function in healthy persons with a history of thymic x irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Rieger, C.H.L.; Kraft, S.C.; Rothberg, R.M.

    1975-10-01

    The possible late effects of x irradiation to the infantile thymus were investigated by studying immune functions in 12 healthy persons with a history of thymic x irradiation and healthy control subjects. No differences were found in serum immunoglobulin values, humoral antibody levels, lymphocyte counts, and lymphocyte reactivity to phytohemagglutinin, vaccinia virus, purified protein derivative (PPD), and allogeneic cells. The irradiation group exhibited cellular hyperresponsiveness to streptokinase-streptodornase (SK-SD). In contrast, mean skin and in vitro lymphocyte responses to Candida albicans were depressed in the patients with thymic irradiation. A dissociation of these two Candida responses was found in only 1 of 14 healthy control subjects but in 7 of 12 irradiated individuals. While thymic irradiation did not result in impaired immunologic defenses leading to clinical disease, it caused alterations in T cell responses similar to those reported in patients with chronic mucocutaneous candidiasis.

  11. Swimming immobility time decreased in prenatally x-irradiated microcephalic rats

    International Nuclear Information System (INIS)

    Seo, Misako; Kiyono, Sigehiro; Shibagaki, Masamitsu

    1986-01-01

    Pregnant rats were X-irradiated (150 R) on gestation day 17, and the offspring were weaned at 21 days of age. After recording the spontaneous activity for one hour using Animex apparatus at 40 days of age, male offspring were tested for swimming immobility time on two consecutive days at 62 days of age. All X-irradiated pups were microcephalic, and their mean total brain weight was 78.5 % of the control group. Although no difference was found in spontaneous activity between the two groups, swimming immobility time was significantly shortened in the microcephalic group. The results suggest that the swimming immobility time is an indicator of adaptability to novel situation rather than an expression of helplessness, lowered mood or depressed state as originally proposed by Porsolt et al. (author)

  12. 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)

  13. Predisposition to cancer and radiosensitivity

    International Nuclear Information System (INIS)

    Pichierri, P.; Franchitto, A.; Palitti, F.

    2000-01-01

    Many cancer-prone diseases have been shown to be radiosensitive. The radiosensitivity has been attributed to pitfalls in the mechanisms of repair of induced DNA lesions or to an impaired cell cycle checkpoint response. Although discrepancies exist in the results obtained by various authors on the radiosensitivity of individuals affected by the same disease, these can be attributed to the large variability observed already in the response to radiation of normal individuals. To date three test are commonly used to assess radiosensitivity in human cells: survival, micronucleus and G 2 chromosomal assay. The three tests may be performed using either fibroblasts or peripheral blood lymphocytes and all the three tests share large interindividual variability. In this regard a new approach to the G 2 chromosomal assay which takes into account the eventual differences in cell cycle progression among individuals has been developed. This new approach is based on the analysis of G 2 homogeneous cell populations. Cells irradiated are immediately challenged with medium containing bromodeoxyuridine (BrdU rd). Then cells are sampled at different post-irradiation times and BrdU rd incorporation detected on metaphases spread and the scoring is done only at time points showing similar incidence of labelled cells among the different donors. Using this approach it has been possible to reduce the interindividual variability of the G 2 chromosomal assay. (author)

  14. Increased chromosome radiosensitivity during pregnancy

    International Nuclear Information System (INIS)

    Ricoul, Michelle; Sabatier, Laure; Dutrillaux, Bernard

    1997-01-01

    It was necessary to consider the risks of exposure of pregnant women, not only in relation to the child, but also in relation to their own hypersensitivity. We have demonstrated that pregnancy increases radiosensitivity of chromosome in the mouse at the end of gestation. This is of importance since it may have implications on radioprotection of pregnant women and give experimental guidelines to the problems of hypersensitivity to drugs and cancer aggravation during pregnancy. Blood obtained from women at various times of pregnancy was exposed to ionizing radiations. By comparison to non-pregnant women, an increase in chromosome breakage was observed in metaphases from lymphocytes, after short-term culture in the presence of the serum of the same donor. Immediately after delivery, this increase in radiosensitivity disappeared. In a prospective study, serial analyses showed a very strong correlation between the amount of pregnancy hormones, progesterone in particular, and the increase in radiosensitivity. Pregnant women may have an increased sensitivity to ionizing radiation during the second half of their pregnancy. This study provides the first evidence in human that radiosensitivity may vary in relation to physiological conditions

  15. Effects of X-irradiation on some aspects of protein metabolism in the frog, Rana hexadactyla

    International Nuclear Information System (INIS)

    Rajarami Reddy, G.; Sasira Babu, K.

    1980-01-01

    Changes in the level of total proteins and protease in brain, muscle and liver tissues of normal and X-irradiated frogs were determined. Low doses of radiation produced an increment in protein level while high doses produced decrement. However, protease activity at all doses exhibited an elevatory trend. Exposure of frogs to lethal doses resulted in increased protease activity and decreased protein content during post-irradiation periods. The results are discussed on the basis of protein destruction and lysosomal damage. (auth.)

  16. Evidence against a systemic humoral factor controlling the intestinal compensatory response following X-irradiation

    International Nuclear Information System (INIS)

    Sharp, J.G.; Osborne, J.W.; Iowa Univ., Iowa City

    1981-01-01

    The investigation was devised to determine whether changes noted in the unirradiated duodenum and colon of single rats after X-irradiation of only the exteriorized rat jejunum and ileum are mediated by a systemic humoral factor. Littermate Holtzman male rats were joined in parabiosis and one month later, the temporarily exteriorized jejunum and ileum of one member was exposed to 1.000 R of 250 kVp X-irradiation. Two days after X-irradiation, and 1, 12 and 24 h after 1 μCi/g bodyweight 3 H-thymidine was injected i.p. rats were sacrificed and appropriate tissues removed. Single rats which had the exteriorized jejunum and ileum irradiated were studied from 1-3 days after irradiation. Crypt cell migration rates were determined employing autoradiography. Tritium content and columnar cell migration rate in duodenum and colon of unirradiated rats compared to irradiated rats indicated that irradiation of one member of the pair had no effect on tritium incorporation or epithelial cell migration in the duodenum or colon of the unirradiated partner. Epithelial cell proliferation and crypt cell migration were increased in unirradiated duodenum and colon of single intestine-irradiated rats. Essentially the same changes were seen in the irradiated member of a parabiotic pair, but none of these changes were noted in the unirradiated member. The absence of stimulation in the unirradiated parabiont suggests that either a systemic humoral factor is not present after X-irradiation or is not present in sufficient concentration to be detected by these methods. (orig./MG)

  17. Characterization of Ninjurin and TSC22 induction after X-irradiation of normal human skin cells

    International Nuclear Information System (INIS)

    Koike, Manabu; Ninomiya, Yasuharu; Koike, Aki

    2008-01-01

    The skin is an external organ that is most frequently exposed to radiation. It is important to elucidate the influence of radiation exposure on the skin at the molecular level. To identify radiation-responsive genes in human skin cells, we used microarray technology to examine the effects of irradiation on 641 genes in normal human epidermal keratinocytes at 4 h and 8 h postirradiation with a cytotoxic dose of X-ray (10 Gy). We found that 18 genes were upregulated and 35 genes were downregulated in keratinocytes at 4 h and/or 8 h postirradiation. Ninjurin, whose function remains unknown in keratinocytes, was induced most strongly by X-irradiation. Several known apoptosis-related genes, such as TSC22, were also upregulated. We characterized Ninjurin and TSC22 induction after X-irradiation of normal human skin cells. The induction of the expression of Ninjurin and TSC22 mRNA in keratinocytes following high-dose X-irradiation was confirmed by northern blot analysis. In dermal fibroblasts, Ninjurin, but not TSC22, was induced after X-ray irradiation. The dependence of both gene expression on the status of an apoptosis regulator, p53, was found. In addition, the expression of both mRNA was induced upon treatment with an apoptosis inducer, etoposide. On the other hand, TSC22, but not Ninjurin, was induced and accumulated in keratinocytes upon treatment with an apoptosis inducer, anisomycin. However, in transient expression assay, EYFP-TSC22, as well as EYFP-Ninjurin or EYFP alone, did not induce apoptosis in keratinocytes in contrast to EYFP-GADD45. Taken together, these findings have important implications on the understanding of the mechanism underlying the complex response of skin cells following X-irradiation. (author)

  18. 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

  19. Epithelial regeneration of transposed intestine after high doses of X irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Both, N.J. de; Vermey, M [Erasmus Universiteit, Rotterdam (Netherlands)

    1976-01-01

    The regeneration capacities of normal and transposed small bowel epithelium were compared in rats after applying high doses of x irradiation. It has been shown that the potency of the mucosa to regenerate was much higher than assumed and that the mucosa could regenerate after single doses varying from 2000 to 5000 R. Even in the villus epithelium and in flat epithelium covering infiltrates of the lamina propria cells survived, which were still able to resume proliferative activity several days after irradiation.

  20. Neuronal damage in chick and rat embryos following X-irradiation

    International Nuclear Information System (INIS)

    Schneider, B.F.; Norton, S.

    1980-01-01

    Exposure of rat and chick embryos to X-irradiation at the time of development of neurons at the telencephalic-diencephalic border results in prolonged damage to neurons in this area as measured by neuronal nuclear size. A dose of 100 rads to the seven-day-old chick embryo has about the same effect as 125 rads to the 15-day-old rat fetus. The nuclear volume of large, multipolar neurons in the chick paleostriatum primitivum and the rat lateral preoptic area are reduced from 10 to 15%. Larger doses of X-irradiation to the chick (150 and 200 rads) cause progressively greater reductions in nuclear size. The large neurons which were measured in the rat and chick are morphologically similar in the two species. Both contain cytoplasmic acetylcholinesterase and have several branched, spiny dendritic processes. The similarity of response of chick and rat neurons to X-irradiation diminishes the significance of maternal factors as the cause of the effects of fetal irradiation in these experiments

  1. Transient virus expression during murine leukemia induction by x-irradiation

    International Nuclear Information System (INIS)

    Haas, M.

    1977-01-01

    Most x-irradiation-induced thymomas in C57BL/6 mice are virus-free when assayed by immunofluorescence for the gs antigen (gsa) of murine leukemia virus (MuLV). Virus was induced transiently in bone marrow cells and later appeared in thymus cells. Six to 7 weeks post irradiation, thymocytes and bone marrow cells were MuLV gsa-negative and remained negative for the lifetime of most animals, whether or not they contracted overt leukemia. During the period when MuLV gsa-positive bone marrow cells were found, XC-positive syncytia-producing bone marrow cells were also found. Virus information was expressed, therefore, for a limited duration, long before any signs of leukemia in the animal were evident. MuLV gsa-positive thymocytes taken from mice 4 weeks after x-irradiation were cocultivated with a series of indicator cells. B-tropic virus, in addition to a xenotropic virus, was isolated from these cells. Ecotropic virus was not found in normal mouse thymocytes, in irradiated thymocytes a few days after termination of the X-irradiation sequence, or in most primary thymomas. All thymocytes produced only xenotropic virus in the cocultivation assays. Expression of the ecotropic virus was, therefore, transient, as assayed by immunofluorescence, XC syncytia formation, and virus isolation from MuLV gsa-positive thymus cells

  2. 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

  3. The protective effect of Royal Jelly against the hemopoiesis dysfunction in X-irradiated mice

    Energy Technology Data Exchange (ETDEWEB)

    Emori, Yutaka; Oka, Hideki; Ohya, Osamu; Tamaki, Hajime; Hayashi, Yoshiro [Zeria Pharmaceutical Co., Ltd., Konan, Saitama (Japan). Central Research Laboratories; Nomoto, Kikuo

    1998-02-01

    The protective effect of Royal Jelly (RJ) against the hemopoietic dysfunction in whole body X-irradiated C57BL/6 mice was investigated. When RJ (1.0 g/kg, po or 0.5 g/kg, ip) was administered every day beginning two weeks before X-irradiation (10 Gy), a significant increase in the number of leukocytes and erythrocytes was observed in mice treated with RJ, as compared with X-irradiated control. In addition, the number of colony forming units in culture (CFU-C) of bone marrow cells or splenocytes was significantly increased in mice treated with RJ. Therefore, when granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin-3 (IL-3) in peripheral blood was measured by ELISA kit, a significant increase in the amount of GM-CSF and IL-3 was observed. These results suggest that the protective effect of RJ against hemopoietic dysfunction could be expressed through an increase in the number of hemopoietic stem cells by the induction of hemopoietic factor such as GM-CSF and IL-3. (author)

  4. Persistent genetic instability induced by synergistic interaction between x-irradiation and 6-thioguanine

    International Nuclear Information System (INIS)

    Grosovsky, A.J.; Nelson, S.L.; Smith, L.E.

    1995-01-01

    Clonal karyotypic analysis was performed using G-banding on four groups of clones derived from TK6 human lymphoblasts: 25 HPRT - total gene deletion mutants induced by exposure to 2 Gy of x-rays; 8 spontaneous HPRT - total gene deletion mutants; 25 clones irradiated with 2 Gy, not selected with 6-thioguanine. Ten to twenty metaphases were examined for each clone. Extensive karyotypic heterogeneity was observed among x-ray induced HPRT - mutants involving translocations, deletions, duplications and aneuploidy; recovery of chromosomal aberrations and karyotypic heterogeneity was greater than the additive effects of clones treated with x-irradiation or 6-thioguanine alone. This synergistic interaction between x-irradiation and 6-thioguanine was observed despite a 7 day phenotypic expression interval between exposure to the two agents. Thus, x-irradiated TK6 cells appear to be persistently hypersensitive to the induction of genetic instability. Several mutants appeared to exhibit evidence of clonal evolution since aberrant chromosomes observed in one metaphase, were found to be further modified in other metaphases. In order to determine if genetic instability, identified by clonal karyotypic heterogeneity, affected specific locus mutation rates, we utilized the heterozygous thymidine kinase (tk) locus as a genetic marker. Four x-ray induced HPRT - mutants with extensive karyotypic heterogeneity, exhibited mutation rates at tk ranging from 5 to 8 fold higher than the parental TK6 cells. Further analysis, using fractionated low dose radiation exposure, is currently in progress

  5. Response of the adrenal medulla to exogenous insulin in head X-irradiated dogs

    Energy Technology Data Exchange (ETDEWEB)

    Yamashita, K; Mieno, M; Shimizu, T [Nagasaki Univ. (Japan). School of Medicine

    1976-12-01

    The observed results on the secretory response of the adrenal medulla to exogenous insulin in dogs whose heads had been irradiated with 200 rad X-irradiation at a rate of 60.6 rad/min are reported. Approximately 20 h after irradiation 2 i.u. insulin/kg body weight was administered to both irradiated and control (non-irradiated) dogs. The secretion of both adrenaline and noradrenaline in five control dogs which received insulin had increased markedly 30 min after the injection and it was sustained over the first 120 min. Five irradiated dogs also responded to the injection of insulin by secreting appreciable amounts of both adrenaline and noradrenaline, but the responsiveness was considerably lower; adrenaline and noradrenaline secretion 30 and 60 min after the injection was 59 and 33% less than that caused by insulin in control animals respectively, and these differences were significant (P < 0.01). Since insulin induces hypoglycaemia and thereby leads to an increase in the adrenal medullary secretion through the central mechanism, the present results observed 1 day after X-irradiation of the head indicate that the susceptibility of the adrenomedullary activating mechanism in the central nervous system may be diminished considerably after X-irradiation, even at doses as low as 200 rad.

  6. Response of the adrenal medulla to exogenous insulin in head X-irradiated dogs

    International Nuclear Information System (INIS)

    Yamashita, K.; Mieno, M.; Shimizu, T.

    1976-01-01

    The observed results on the secretory response of the adrenal medulla to exogenous insulin in dogs whose heads had been irradiated with 200 rad X-irradiation at a rate of 60.6 rad/min are reported. Approximately 20 h after irradiation 2 i.u. insulin/kg body weight was administered to both irradiated and control (non-irradiated) dogs. The secretion of both adrenaline and noradrenaline in five control dogs which received insulin had increased markedly 30 min after the injection and it was sustained over the first 120 min. Five irradiated dogs also responded to the injection of insulin by secreting appreciable amounts of both adrenaline and noradrenaline, but the responsiveness was considerably lower; adrenaline and noradrenaline secretion 30 and 60 min after the injection was 59 and 33% less than that caused by insulin in control animals respectively, and these differences were significant (P < 0.01). Since insulin induces hypoglycaemia and thereby leads to an increase in the adrenal medullary secretion through the central mechanism, the present results observed 1 day after X-irradiation of the head indicate that the susceptibility of the adrenomedullary activating mechanism in the central nervous system may be diminished considerably after X-irradiation, even at doses as low as 200 rad. (U.K.)

  7. Effect of single x-irradiation on glucocorticoid function of adrenal glands of adult and old rats

    International Nuclear Information System (INIS)

    Gorban', Je.M.; Topol'nyikova, N.V.

    2001-01-01

    The peculiarities of short-term (1 h, 1 day) adrenal glucocorticoid function in adult and old rats after single x-irradiation at different doses was studied. changes in the glucocorticoid function of the adrenal glands at studied terms after single x-irradiation at used doses were observed in adult but not in old animals. This testifies to an age-related decrease in the range of adaptive possibilities of this link of the organism adaptive system to x-irradiation effects

  8. Radiosensitivity and chimera formation in Hibiscus syriacus

    International Nuclear Information System (INIS)

    Kwon, S.H.; Won, J.L.

    1980-01-01

    Radiosensitivity of gamma-irradiated Hibiscus syriacus and chimera formation were investigated. The lethal dose-50 percent with respect to seeding and cuttings was 15kR and 2 approximately 3 kR respectively, chlorophyll mutation rate of seeds irradiated with 15 kR being about 13 percent. The degree of chimeric leaf mutants from the buds by radiation treatment depends on the bud position of the branch. Buds of the middle part of V 1 branch seemed to be more multi-cellular condition than the upper and low part when irradiation was made. It is assumed that at least two primordia of V 2 branch were already differentiated from the V 1 branch in Hibiscus syriacus plant. (Author)

  9. Involvement of placental/umbilical cord blood acid-base status and gas values on the radiosensitivity of human fetal/neonatal hematopoietic stem/progenitor cells

    International Nuclear Information System (INIS)

    Yamaguchi, Masaru; Ebina, Satoko; Kashiwakura, Ikuo

    2013-01-01

    Arterial cord blood (CB) acid-base status and gas values, such as pH, PCO 2 , PO 2 , HCO 3 - and base excess, provide useful information on the fetal and neonatal condition. However, it remains unknown whether these values affect the radiosensitivity of fetal/neonatal hematopoiesis. The present study evaluated the relationship between arterial CB acid-base status, gas values, and the radiosensitivity of CB hematopoietic stem/progenitor cells (HSPCs). A total of 25 CB units were collected. The arterial CB acid-base status and gas values were measured within 30 min of delivery. The CD34 + HSPCs obtained from CB were exposed to 2 Gy X-irradiation, and then assayed for colony-forming unit-granulocyte-macrophage, burst-forming unit-erythroid (BFU-E), and colony-forming unit-granulocyte erythroid, macrophage and megakaryocyte cells. Acid-base status and gas values for PCO 2 and HCO 3 - showed a statistically significant negative correlation with the surviving fraction of BFU-E. In addition, a significant positive correlation was observed between gestational age and PCO 2 . Moreover, the surviving fraction of BFU-E showed a significant negative correlation with gestational age. Thus, HSPCs obtained from CB with high PCO 2 /HCO 3 - levels were sensitive to X-irradiation, which suggests that the status of arterial PCO 2 /HCO 3 - influences the radiosensitivity of fetal/neonatal hematopoiesis, especially erythropoiesis. (author)

  10. The effect of low-dose X-irradiation on immune system

    International Nuclear Information System (INIS)

    Ishii, Keiichiro

    1996-01-01

    The hypothesis of radiation hormesis has been proposed. To elucidate the hormetic effect on the immune system, we studied the mitogen-induced proliferation of splenocytes of F344/NSlc rat and BALB/c mouse after low-dose X-irradiation. Con A, PHA or LPS-induced proliferation of rat splenocytes prepared at 4 hr after irradiation was augmented with 5 cGy. This augmentation was observed within a few hours after irradiation, being a temporary effect. In case of mice, the proliferation of splenocytes induced by Con A, PHA or LPS was augmented by irradiation with 2.5 cGy. Thus, some phenomena of hormetic effect on the immune system were observed. However, the mechanism of augmentation of immune splenocytes is uncertainty. Therefore, we examined changes in production of LTB 4 and IL-1 being inflammatory mediators. After 5 cGy irradiation the production of LTB 4 of rat splenocyte showed a significant increase. Furthermore, 2.5 cGy irradiation also enhanced, the biological activity of intracellular IL-1 of LPS-stimulated mouse splenocytes. Additionally, to elucidate the stimulative effect on the antitumor immunity by low-dose X-irradiation, we studied the changes in the incidence of thymic lymphoma using AKR mice and of spontaneous metastasis to lung using tumor bearing mice. The incidence of thymic lymphoma was significantly decreased and the life span was significantly prolonged by periodical low-dose X-irradiation in terms of breeding of AKR mice. By an irradiation with 15 cGy, numbers of lung colony in the tumor bearing mice were decreased by 57% relative to the sham-irradiated controls. Then, IL-6 and TNF-α production of tumor bearing mice splenocytes were enhanced. These findings suggest that the low-dose X-irradiation might have caused a light inflammation and might have induced an augmentation of immune splenocytes. Furthermore, these results indicate that an augmentation of the antitumor immunity was induced by low-dose X-irradiation. (author). 127 refs

  11. The effect of low-dose X-irradiation on immune system

    Energy Technology Data Exchange (ETDEWEB)

    Ishii, Keiichiro [Central Research Inst. of Electric Power Industry, Komae, Tokyo (Japan). Komae Research Lab.

    1996-06-01

    The hypothesis of radiation hormesis has been proposed. To elucidate the hormetic effect on the immune system, we studied the mitogen-induced proliferation of splenocytes of F344/NSlc rat and BALB/c mouse after low-dose X-irradiation. Con A, PHA or LPS-induced proliferation of rat splenocytes prepared at 4 hr after irradiation was augmented with 5 cGy. This augmentation was observed within a few hours after irradiation, being a temporary effect. In case of mice, the proliferation of splenocytes induced by Con A, PHA or LPS was augmented by irradiation with 2.5 cGy. Thus, some phenomena of hormetic effect on the immune system were observed. However, the mechanism of augmentation of immune splenocytes is uncertainty. Therefore, we examined changes in production of LTB{sub 4} and IL-1 being inflammatory mediators. After 5 cGy irradiation the production of LTB{sub 4} of rat splenocyte showed a significant increase. Furthermore, 2.5 cGy irradiation also enhanced, the biological activity of intracellular IL-1 of LPS-stimulated mouse splenocytes. Additionally, to elucidate the stimulative effect on the antitumor immunity by low-dose X-irradiation, we studied the changes in the incidence of thymic lymphoma using AKR mice and of spontaneous metastasis to lung using tumor bearing mice. The incidence of thymic lymphoma was significantly decreased and the life span was significantly prolonged by periodical low-dose X-irradiation in terms of breeding of AKR mice. By an irradiation with 15 cGy, numbers of lung colony in the tumor bearing mice were decreased by 57% relative to the sham-irradiated controls. Then, IL-6 and TNF-{alpha} production of tumor bearing mice splenocytes were enhanced. These findings suggest that the low-dose X-irradiation might have caused a light inflammation and might have induced an augmentation of immune splenocytes. Furthermore, these results indicate that an augmentation of the antitumor immunity was induced by low-dose X-irradiation. 127 refs.

  12. Biochemical evidence for deficient DNA repair leading to enhanced G2 chromatid radiosensitivity and susceptibility to cancer

    International Nuclear Information System (INIS)

    Gantt, R.; Parshad, R.; Price, F.M.; Sanford, K.K.

    1986-01-01

    Human tumor cells and cells from cancer-prone individuals, compared with those from normal individuals, show a significantly higher incidence of chromatid breaks and gaps seen in metaphase cells immediately after G2 X irradiation. Previous studies with DNA repair-deficient mutants and DNA repair inhibitors strongly indicate that the enhancement results from a G2 deficiency(ies) in DNA repair. We report here biochemical evidence for a DNA repair deficiency that correlates with the cytogenetic studies. In the alkaline elution technique, after a pulse label with radioactive thymidine in the presence of 3-acetylaminobenzamide (a G2-phase blocker) and X irradiation, DNA from tumor or cancer-prone cells elutes more rapidly during the postirradiation period than that from normal cells. These results indicate that the DNA of tumor and cancer-prone cells either repairs more slowly or acquires more breaks than that of normal cells; breaks can accumulate during incomplete or deficient repair processes. The kinetic difference between normal and tumor or cancer-prone cells in DNA strand-break repair reaches a maximum within 2 h, and this maximum corresponds to the kinetic difference in chromatid aberration incidence following X irradiation reported previously. These findings support the concept that cells showing enhanced G2 chromatid radiosensitivity are deficient in DNA repair. The findings could also lead to a biochemical assay for cancer susceptibility

  13. Effect of electroporation on radiosensitization with cisplatin in two cell lines with different chemo- and radiosensitivity

    International Nuclear Information System (INIS)

    Kranjc, S.; Cemazar, M.; Grosel, A.; Pipan, Z.; Sersa, G.

    2003-01-01

    Aim. Radiosensitization with cisplatin can be enhanced by electroporation of cells and tumours. The aim of this study was to extend our previous studies on two carcinoma tumour models with different chemo- and radiosensitivity in order to evaluate whether this treatment is effective also on less chemo- and radiosensitive tumour cells. Materials and methods. This in vitro study was performed on carcinoma SCK and EAT-E cells. The cytotoxicity of three-modality treatment consisting of cisplatin, electroporation and irradiation was determined by the clonogenic assay. Results. The radiosensitizing effect of cisplatin on the two cell lines was greatly enhanced by electroporation. By this combined treatment, less chemo and radiosensitive EAT-E cells were rendered as sensitive as more chemo and radiosensitive SCK cells. Conclusion. The enhancement of cisplatin-induced radiosensitization of cells by electroporation could be beneficially used in the treatment of intrinsically less chemo- and radiosensitive tumours. (author)

  14. Increased radiosensitivity of cerebral capillaries in neonatal Gunn rats as compared to Sprague-Dawley rats

    International Nuclear Information System (INIS)

    Landolt, R.; Arn, D.

    1979-01-01

    The extent of petechial haemorrhages of the cerebral cortex examined between 14 hours and 4 days after X-irradiation to the head was compared in Sprague-Dawley and homozygous Gunn rats with congenital hyperbilirubinaemia. Animals 1 to 2 days old received single doses of either 250, 500 or 750 rad. By means of a special scoring scale the degree of the damage to the micro vasculature was semi-quantitatively estimated. In both strains a significant difference in effect was obtained between 250 and 500 rad, but not between 500 and 750 rad. The shape of the dose-effect curve in Gunn rats was similar to that of Sprague-Dawley rats, but displaced upwards. In Gunn rats the effect of 250 rad was greater that that of 750 rad in Sprague-Dawley rats. Possible radiosensitizing mechanisms are discussed with reference to the literature and these results. (author)

  15. Histopathologic changes induced in rats by localized x-irradiation of an exteriorized segment of the small intestine

    Energy Technology Data Exchange (ETDEWEB)

    Sebes, J I; Zaldivar, R; Vogel, Jr, H H [Tennessee Univ., Memphis (USA). Dept. of Radiation Oncology; Tennessee Univ., Memphis (USA). Dept. of Diagnostic Radiology)

    1975-10-01

    The sequence of histopathological changes was described after X-irradiation of the exteriorized segment (3 cm) of the rat ileum with a single dose of 2,200 R. A one-year follow-up was provided in rats whose exteriorized intestinal segments were irradiated. Comparisons were made between one group of animals in which the superior mesenteric artery and vein were clamped during irradiation and a second group in which these vessels were not clamped. A third group of sham-irradiated controls was used for comparisons. There was a delay in the onset and progression of the radiation damage to the mucosa of the hypoxic animals in the acute post-irradiation phase. In addition, prolongation of survival in the rats with the superior mesenteric vessels clamped was observed. Mucosal regeneration was noted, occurring at 52 days post-exposure. No adenocarcinomas were found up to 354 days after irradiation. An angiofibroma and a highly differentiated osteoid lesion were described.

  16. Effects of AET, MEA, or 5-HT treatment before X-irradiation of pregnant C57B mice

    International Nuclear Information System (INIS)

    Mazur, L.

    1985-01-01

    C57B mice were either whole body X-irradiated with a dose of 200 R or, 15 minutes before X-radiation injected with AET, MEA, or 5-HT, in a dose of 40 mg/kg of body weight, on the first day of gestation. Uterine contents were examined on the nineteenth day of pregnancy. The number of corpora lutea was assumed as 100% and the percentage values of live and dead foetuses, resorptions, and non-implanted embryos were calculated. The percentage ratio of females with live foetuses in the uterus, in relation to the total number of those with a vaginal plug was also determined. X-irradiation of pregnant mice influenced the embryonic survival. As compared with controls, in only X-irradiated mice a lower percentage value of live foetuses and higher percentage values of non-implanted embryos and resorptions were found. One dead foetus was only observed in X-irradiated females. Percentage value of X-irradiated females with live foetuses was lower than that of control ones. High mortality of embryos occurred more often before than after the implantation of blastocysts. The percentage value of non-implanted embryos was higher than that of resorptions. AET, MEA, and 5-HT when injected to mice before their X-irradiation acted as radioprotectors. The strongest radioprotective effect was obtained following AET administration, intermediate after 5-HT treatment and the weakest one when MEA was injected. (orig.) [de

  17. Membrane specific drugs as radiosensitizers

    Energy Technology Data Exchange (ETDEWEB)

    George, K.C.; Mishra, K.P.; Shenoy, M.A.; Singh, B.B.; Srinivasan, V.T.; Verma, N.C.

    1981-01-01

    Procaine, paracetamol, and chlorpromazine showed inhibition of post irradiation repair. The chlorpromazie effect could be further augmented by treatment of cells with procaine. Chlorpromazine was also found to be preferentially toxic to hypoxid bacterial cells, and the survivors showed extreme radiosensitivity to gamma rays. Chlorpromazine was found to inhibit tumour growth in swiss mice when given intraperitoneally as well as when injected directly into the tumour. When combined with single x-ray doses, significant radiosensitization was observed in two in vivo tumours sarcoma 180A and fibrosarcoma. These results indicated that chlorpromazine may prove a good drug for combined chemo-radiotherapy of solid tumours. Investigations continued studying various aspects such as effectiveness in other tumour lines, distribution in healthy and tumour bearing animals, hyperthermia and drug combination effects, and encapsulation of the drug in artificial liposomes and blood cells. (ERB)

  18. Radiosensitivity of garlic air bulbs

    International Nuclear Information System (INIS)

    Zhila, Eh.D.

    1975-01-01

    The paper presents data on the radiosensitivity of various sorts of garlic. It is shown that the frequency of chromosomal aberrations in the irradiated aerial bulbs of stemmed varieties of garlic is directly dependent upon the gmma-ray dose. With increasing dose the germination capacity and the viability of the plants diminishes. A dose of 750 r was found to be critical for the bulbs of the garlic varieties studied

  19. Radiosensitivity in ataxia-telangiectasia

    International Nuclear Information System (INIS)

    Lavin, M.F.; Khanna, K.K.; Watters, D.

    1998-01-01

    Full text: Radiosensitivity is a major hallmark of the human genetic disorder ataxia-telangiectasia. This hypersensitivity to ionizing radiation has been demonstrated in vitro after exposure of patients to therapeutic thought to be the major factor contculture. Clearly an understanding of the nature of the molecular defect in ataxia-telangiectasia will be of considerable assistance in delineating additional pathways that determine cellular radiosensitivity/radioresistance. Furthermore, since patients with this syndrome are also predisposed to developing a number of leukaemias and lymphomas the possible connection between radiosensitivity and cancer predisposition is of interest. Now that the gene (ATM) responsible for this genetic disease has been cloned and identified, progress is being made in determining the role of the ATM protein in mediating the effects of cellular exposure to ionizing radiation and other forms of redox stress. Proteins such as the product of the tumour suppressor gene p53 and the proto-oncogene c-Abl (a protein tyrosine kinase) have been shown to interact with ATM. Since several intermediate steps in both the p53 and c-Abl pathways, activated by ionizing radiation, are known it will be possible to map the position of ATM in these pathways and describe its mechanism of action. What are the clinical implications of understanding the molecular basis of the defect in ataxia-telangiectasia? As outlined above since radiosensitivity is a universal characteristic of A-T understanding the mechanism of action of ATM will provide additional information or radiation signalling in human cells. With this information it may be possible to sensitize tumour cells to radiation and thus increase the therapeutic benefit of radiotherapy. This might involve the use of small molecules that would interfere with the normal ATM controlled pathways and thus sensitize cells to radiation or alternatively it might involve the efficient introduction of ATM anti-sense c

  20. Radiosensitivity in ataxia-telangiectasia

    Energy Technology Data Exchange (ETDEWEB)

    Lavin, M.F. [Royal Brisbane Hospital, QLD (Australia). Queensland Institute of Medical Research and The Department of Surgery; Khanna, K.K.; Watters, D. [Royal Brisbane Hospital, QLD (Australia). Queensland Institute of Medical Research

    1998-12-31

    Full text: Radiosensitivity is a major hallmark of the human genetic disorder ataxia-telangiectasia. This hypersensitivity to ionizing radiation has been demonstrated in vitro after exposure of patients to therapeutic thought to be the major factor contculture. Clearly an understanding of the nature of the molecular defect in ataxia-telangiectasia will be of considerable assistance in delineating additional pathways that determine cellular radiosensitivity/radioresistance. Furthermore, since patients with this syndrome are also predisposed to developing a number of leukaemias and lymphomas the possible connection between radiosensitivity and cancer predisposition is of interest. Now that the gene (ATM) responsible for this genetic disease has been cloned and identified, progress is being made in determining the role of the ATM protein in mediating the effects of cellular exposure to ionizing radiation and other forms of redox stress. Proteins such as the product of the tumour suppressor gene p53 and the proto-oncogene c-Abl (a protein tyrosine kinase) have been shown to interact with ATM. Since several intermediate steps in both the p53 and c-Abl pathways, activated by ionizing radiation, are known it will be possible to map the position of ATM in these pathways and describe its mechanism of action. What are the clinical implications of understanding the molecular basis of the defect in ataxia-telangiectasia? As outlined above since radiosensitivity is a universal characteristic of A-T understanding the mechanism of action of ATM will provide additional information or radiation signalling in human cells. With this information it may be possible to sensitize tumour cells to radiation and thus increase the therapeutic benefit of radiotherapy. This might involve the use of small molecules that would interfere with the normal ATM controlled pathways and thus sensitize cells to radiation or alternatively it might involve the efficient introduction of ATM anti-sense c

  1. Studies on Drosophila radiosensitivity strains

    International Nuclear Information System (INIS)

    Varentsova, E.R.; Sharygin, V.I.; Khromykh, Yu.U.

    1985-01-01

    Fertility of radiosensitive mutant drosophila female strain rad (2) 201 61 after irradiation and frequency of dominant lethal mutations (DLM), induced by γ-radiation for 0-5 h and 5-7 days, are investigated. It is shown, that oocytes of the mutant strain are more radiosensitive as compared with cells of mongrel flies as to criterion of DLM appearance over the period of maturing. Early oocytes of stages 2-7 are the most sensitive, i.e. at the stages, corresponding to the manifestation of previously established recombination-defective properties of mutations rad (2) 201 61 . It is also sown, that doses of γ-rays, exceeding 10 Gy produce a strong sterilizing effect on mutant females due to destruction and resorption of egg chambers, irradiated at the stages of previtellogenetic growth of oocytes. In females, carrying mutation of radiosensitivity there is no direct correlation betwen sensitivity of oocytes proper to DLM induction and sensitivity of egg folleicles to resorbing effect of γ-rays. The ways of possible involvement of mutant locus studied into genetic processes in various specialized cells of drosophila

  2. Potentiation of radiosensitivity by tetrandrine in human breast cancer cells and its mechanism

    International Nuclear Information System (INIS)

    Sun Xinchen; Zhen Yongsu; Shao Rongguang; Wang Junjie

    2003-01-01

    Objective: To investigate the potentiation of radiosensitivity and mechanism by tetrandrine (Tet) in human breast cancer p53-mutant MCF-7/ADR and p53-wt MCF-7 cells. Methods: Clonogenic assay, flow cytometry, Western blotting were preformed in this experiment. Results: The data of clonogenic assay showed that Tet markedly sensitized MCF-7/ADR cell to X-rays, and the sensitization enhancement ratio (SER) of Tet was 1.51. Flow cytometry assay showed that exposure of MCF-7/ADR cells to X-rays caused cells to arrest in G 2 phase, whereas Tet was able to lower the number of cells arrested in G 2 phase. However, in MCF-7 cells, the potentiation effect of Tet was lower, and its SER was 1.10. MCF-7 cells were induced to arrest in G 1 and G 2 phases by X-rays, and the number of cells arrested in G 2 phase abrogated by Tet was less than that in MCF-7/ADR cells. Furthermore, the results showed that the levels of Cyclin B1 and Cdc2 expression decreased after X-irradiation, and the mitotic index was lower too. Tet could reverse this decrease and induce X-ray-irradiated cells to enter mitosis. Conclusion: Tet is a potent G 2 checkpoint abrogator and markedly enhances the cytotoxicity of X irradiation in the p53-mutant cancer cells

  3. The inherited basis of human radiosensitivity

    International Nuclear Information System (INIS)

    Gatti, R.A.

    2001-01-01

    Certain individuals cannot tolerate 'conventional' doses of radiation therapy. This is known to be true of patients with ataxia-telangiectasia and ligase IV deficiency. Although in vitro testing may not correlate completely with clinical radiosensitivity, fibroblasts and lymphoblasts from patients with both of these disorders have been clearly shown to be radiosensitive. Using a colony survival assay (CSA) to test lymphoblastoid cells after irradiation with 1 Gy, a variety of other genetic disorders have been identified as strong candidates for clinical radiosensitivity, such as Nijmegen breakage syndrome, Mre11 deficiency, and Fanconi's anemia. These data are presented and considered as a starting-point for the inherited basis of human radiosensitivity

  4. Independent occurence of gastric tumor and intestinal metaplasia by x-irradiation

    International Nuclear Information System (INIS)

    Watanabe, Hiromitsu; Ito, Akihiro

    1986-01-01

    The selective occurence of gastric tumors and intestinal metaplasias in the stomach by X-irradiation were described both in mice and rats. The appearance of both lesions was greatly influenced by animal's strains in both species and also by the sex in rats. A few gastric tumors were observed in the animals given a high does with spilt into low doses of X-irradiation. The adequate dose for gastric tumorigenesis may be around 20 Gy in mice and 15 Gy in rats. A good relationship between X-ray dose and incidence of gastric tumor was observed in ICR mice. Frequency of intestinal metaplasia by X-irradiation was much higher in rats compared to that in mice. X-ray dose requested for moderate and induction of intestinal metaplasia was decreased with a dose which was induced erosion and gastric tumor. It has been empirically clarified that an elevation of pH value in the gastric juice is one of the principal factors responsible for the development of intestinal metaplasia in the gastric mucosa among the conditions thus for introduced. In this article, we have introduced the relevant examples about intestinal metaplasia without carcinogenic insult, and the relationship between gastric tumor and intestinal metaplasia were described. The intestinal metaplasia was not always observed within or adjacent to neoplastic gastric glands. A combined treatment of X-ray and MNNG was not effective for gastric tumor and frequency of intestinal metaplasia was inversely related to the incidence of gastric tumors. In conclusion, occurrence of gastric tumor and intestinal metaplasia may be independent, and intestinal metaplasia might not be a prerequite for the occurrence of gastric tumor. (author)

  5. Effect of low level prenatal X-irradiation on postnatal growth in the Wistar rat

    International Nuclear Information System (INIS)

    Jensh, R.P.; Brent, R.L.

    1988-01-01

    Forty-five pregnant Wistar strain rats were exposed to 0.0, 0.4, 0.6, or 0.8 Gy X-radiation on the 9th or 17th day of gestation to determined if prenatal X-irradiation would result in alterations in postnatal growth or growth rate. The mothers delivered their offspring, and the litters were reduced to a maximum of eight per litter on the second postnatal day. The 336 offspring were weighed weekly from day 3 until day 86, at which time they were killed, an autopsy was performed, and selected organs were removed and weighed. Postnatal growth rates did not differ significantly in irradiated offspring compared to sham irradiated animals. Irradiation on the 9th day, at any of the 3 dosage levels, did not result in significant differences in weekly weight. Weekly weight remained significantly lower due to irradiation on the 17th day of gestation. The gonadal weight ratio was significantly reduced in males irradiated on the 9th day. There were not other statistically significant changes in organ weight or organ/body weight ratios due to these levels of prenatal X-irradiation on the 9th or 17th day of pregnancy. These results indicate that low level prenatal X-irradiation, on the 17th day of rat gestation, causes prenatal growth retardation, evident at birth, which is not recuperable postnatally. Exposure to x-radiation at this time, however, does not affect the rate at which offspring grow during postnatal life. Offspring are smaller because they never fully recover from the original radiation-induced prenatal growth retardation

  6. Effect of x-irradiation in rats bearing walker-256-carcinosarcoma and normal rats

    International Nuclear Information System (INIS)

    Ehara, Kazuhiko

    1978-01-01

    Serum protein fractions and total proteins were studied with bloods obtained from the rats exposed each to the partial-, whole-bodies and the transplanted tumors (Walker-256-carcinosarcoma transplanted in the right hind leg). The electrophoretic variation induced in the sera of tumor-bearing rats (Group II), and the content of total proteins decreased. Early irradiation to the tumor part of rats less induced the variations of the electrophoretic pattern and the decrease of the amount of serum total proteins. When the distant metastasis appeared during irradiation treatment, the electrophoretic patterns and content of total proteins changed proportionally to the variation in sera of Group II. On the other hand, the γ-globulin (G) fraction increased in the long-term survival rat. The separation of the rat serum β-G into two peaks of β 1 - and β 2 -G was shown only in Group IV (late irradiation to the right hind leg). This finding supposed that some factors involve in the sera of rats with transplanted primary tumor grown up to a fixed size and guessed the appearance of the distant metastasis during x-irradiation. The percentages of the albumin and γ-G decreased slightly and those of the α 1 -, α 2 - and β-G increased slightly in the rats with 300 rad partial-body (the right hind leg) x-irradiation daily for 20 days. The remarkable decrease of the albumin and γ-G, the increase of the α 1 - and β-G, the marked increase of the α 2 -G and the decrease of serum total proteins were demonstrated for the sera of rats with 1,000 rad whole-body x-irradiation at a time. These phenomena seem to be related to the destructive and reticuloendothelial injury by the exposure. (auth.)

  7. RNA precursor pool metabolism and RNA synthesis in X-irradiated Tetrahymena

    International Nuclear Information System (INIS)

    Stephens, R.E.; Paul, I.J.; Zimmerman, A.M.

    1976-01-01

    The incorporation of a radioactive RNA precursor ( 3 H-uridine) has been used in many studies as an index for measuring the synthesis of RNA, yet there is a distinct possibility that the results so obtained were significantly influenced by radiation-induced effects on the metabolism of this precursor into UTP (the primary immediate precursor of RNA) before its incorporation into RNA. A direct examination was therefore undertaken of the effects of X-irradiation on the metabolism of 3 H-uridine and its relationship to RNA synthesis as determined by incorporation. X-irradiation of logarithmically growing Tetrahymena pyriformis caused a dose-dependent depression of total cellular RNA synthesis. Ribosomal RNA (which comprises about 80 per cent of total cellular RNA) synthesis was also depressed by X-irradiation in a dose-dependent manner. Measurements of the levels of radioactivity present in the UTP precursor pool of both irradiated and unirradiated cells were obtained by means of DEAE-cellulose column chromatography of the extracted free nucleotides. Metabolism of 3 H-uridine into UMP, UDP and UTP was depressed by 40%, 26% and 27% respectively, whereas incorporation of 3 H-uridine into RNA was depressed by 77%. The results show that about one-third of the observed (apparent) depression in RNA synthesis was due to radiation-induced effects on the precursor pool, and the remaining two-thirds due to some definite effect of radiation at the transcription level leading to depressed synthesis of RNA. (U.K.)

  8. Cytotoxic effect of x-irradiation of mouse tumor cells in the presence of Korean ginseng extract

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Hyoung Cheol; Kim, Jin Ki; Kim, Jung Soo [College of Medicine, Chonbuk National Univ., Junju (Korea, Republic of); Choi, Dong Seong [College of Medicine, Woosuck Univ., Wanju (Korea, Republic of)

    2000-09-01

    We already reported the results that aqueous extract of Korean ginseng roots showed a marked cytotoxicity. In this study, we investigated whether combined ginseng product with X-irradiation increase the cytotoxicity of tumor cells than X-irradiation or not. Fifty gram of Korean ginseng powder mixed with 1 L of distilled water was extracted with reflux flask under condition of 100 .deg. C for 5 hrs. This aqueous ginseng extract was filtered, centrifuged and then was freezed under condition of -90 .deg. C for 16-18 hrs. The freezing extract was dried with freeze drier, and then diluted. X-irradiation was given to tumor cells by 6 MeV linear accelerator. The cytotoxicity of ginseng in vitro was evaluated from its ability to reduce the clonogenecity of fibrosarcoma (FSa ll) cells. In X-irradiation alone group, each 2, 4, 6 and 8 Gy was given to tumor cells. In X-irradiation with ginseng group, 0.2 mg/mL or ginseng extract was exposed to tumor cells for 1 hour before X-irradiation. The yield for 50 g of ginseng extract which was treated with freezing drier was 3.13 g(6.3%). Cytotoxicity in vitro was measured as survival fraction which was judged from the curve, at ginseng concentration of 0.001, 0.01, 0.1 and 1 mg/ml were 0.89{+-}0.04, 0.86{+-}0.06, 0.73{+-}0.01 and 0.09{+-}0.02, respectively. Survival fraction at X-irradiation alone of 2, 4, 6 and 8 Gy were 0.81{+-}0.07, 0.42{+-}0.08, 0.15{+-}0.02, 0.03{+-}0.01, respectively. But, survival fraction in combined group of X-irradiation and ginseng (0.2mg/mL) at each same radiation dose were 0.28{+-}0.01, 0.18{+-}0.03, 0.08{+-}0.02, 0.006{+-}0.002, respectively (p<0.05). The yield for ginseng extract which was treated with freezing drier was 6.3%. Cytotoxicity of Fsa II in combined ginseng with X-irradiation group was increased than that at X-irradiation alone group, and its enhancing effect seemed to be added.

  9. Cytotoxic effect of x-irradiation of mouse tumor cells in the presence of Korean ginseng extract

    International Nuclear Information System (INIS)

    Kwon, Hyoung Cheol; Kim, Jin Ki; Kim, Jung Soo; Choi, Dong Seong

    2000-01-01

    We already reported the results that aqueous extract of Korean ginseng roots showed a marked cytotoxicity. In this study, we investigated whether combined ginseng product with X-irradiation increase the cytotoxicity of tumor cells than X-irradiation or not. Fifty gram of Korean ginseng powder mixed with 1 L of distilled water was extracted with reflux flask under condition of 100 .deg. C for 5 hrs. This aqueous ginseng extract was filtered, centrifuged and then was freezed under condition of -90 .deg. C for 16-18 hrs. The freezing extract was dried with freeze drier, and then diluted. X-irradiation was given to tumor cells by 6 MeV linear accelerator. The cytotoxicity of ginseng in vitro was evaluated from its ability to reduce the clonogenecity of fibrosarcoma (FSa ll) cells. In X-irradiation alone group, each 2, 4, 6 and 8 Gy was given to tumor cells. In X-irradiation with ginseng group, 0.2 mg/mL or ginseng extract was exposed to tumor cells for 1 hour before X-irradiation. The yield for 50 g of ginseng extract which was treated with freezing drier was 3.13 g(6.3%). Cytotoxicity in vitro was measured as survival fraction which was judged from the curve, at ginseng concentration of 0.001, 0.01, 0.1 and 1 mg/ml were 0.89±0.04, 0.86±0.06, 0.73±0.01 and 0.09±0.02, respectively. Survival fraction at X-irradiation alone of 2, 4, 6 and 8 Gy were 0.81±0.07, 0.42±0.08, 0.15±0.02, 0.03±0.01, respectively. But, survival fraction in combined group of X-irradiation and ginseng (0.2mg/mL) at each same radiation dose were 0.28±0.01, 0.18±0.03, 0.08±0.02, 0.006±0.002, respectively (p<0.05). The yield for ginseng extract which was treated with freezing drier was 6.3%. Cytotoxicity of Fsa II in combined ginseng with X-irradiation group was increased than that at X-irradiation alone group, and its enhancing effect seemed to be added

  10. Fine-structural effects of 1200-R abdominal x irradiation on rat intestinal epithelium

    International Nuclear Information System (INIS)

    Lieb, R.J.; McDonald, T.F.; McKenney, J.R.

    1977-01-01

    Male Charles River CD rats were shielded from the xiphoid process cranially with lead and were exposed to 1200-R abdominal x irradiation. Animals were sacrificed at 1 through 4 days following irradiation and tissues from both ileum and jejunum were prepared for electron microscopic examination. At the fine-structural level early changes were confined to a proliferation and dilation of smooth endoplasmic reticulum and to an increase in the number of lysosomes. At 4 days postirradiation, cells covering the villi were cuboidal rather than columnar and appeared to be immature crypt-type cells. The appearance of these cells was coincident with the onset of diarrhea in these animals

  11. Nucleic acid metabolism in sea urchin embryos and its alteration after x-irradiation

    International Nuclear Information System (INIS)

    Kimura, I.

    1974-01-01

    Nucleic acid metabolism observed during embryogenesis of the sea urchin (Hemicentrotus pulcherrimus) and its alteration after x irradiation were studied on both qualitative and quantitative bases. MAK chromatographic analysis has revealed that the stage-dependent synthesis of RNA occurred during embryogenesis: some RNA families were observed specifically for early cleavage stage, not being observed at stages later than gastrulation. Further, they were modified by irradiation pari passu with delay and inhibition of cleavage. These results were discussed in comparison with our previous results on normal and regenerating rat liver

  12. 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.)

  13. Effects of X-irradiation on gonadotropin secretion in rat anterior pituitary cells

    International Nuclear Information System (INIS)

    Li Xinmin; Liu Shuzheng

    1988-01-01

    The dispersed rat anterior pituitary cells cultured in 3 days was exposed to single doses of X-irradiation in the range of 0.5-8.0 Gy. LH and FSH contents in both the supernatant and the cells were measured. The LH secretion was significantly increased at the doses greater than 0.5 Gy and FSH secretion was also significantly enhanced at the dose of 4.0 Gy. The cellular contents of both LH and FSH remained near the control levels. It is concluded that gonadotropin secretion can be stimulated by single doses of X-rays in the range of 0.5-8.0 Gy

  14. The effect of x-irradiation on the development of Fasciola gigantica (cobbold, 1885) in goats

    International Nuclear Information System (INIS)

    Ravi Chandra

    1976-01-01

    The effect of varying doses (1 kr, 3 kr, 5 kr) of x-irradiation on the development of Fasciola gigantica, the common liver fluke of livestock in India has been investigated in goat kids with a view to develop a radiation attenuated vaccine against the pathogen. The growth and development of the flukes recovered from animals infected with irradiated metacercarie is found to be retarded. Metacecariae exposed to 3 kr can develop further, but number of flukes recovered from animals infected with metacecariae exposed to 5 kr is considerably less than the one from animals infected with non-irradiated metacercariae. (M.G.B.)

  15. Effect of local x-irradiation on mice reproduction in two successive generations

    International Nuclear Information System (INIS)

    Strel'nikova, N.K.; Lisenkova, L.N.

    1978-01-01

    For an experimental assessment of the biologic effectiveness of a single exposure to local irradiation exposure in simulating the conditions of exposure in X ray studies, an experiment was carried out on white mice. Mice of two successive generations were exposed to local X irradiation in the eye region. The radiation was found to bring about changes in the reproductive function (such as sterility, reduced litter size and fertility of females); these changes being dose-dependent in a nonlinear manner. The biologic effect of irradiation was greater in the second-generation mice

  16. Alteration in adenylate cyclase response to aminergic stimulation following neonatal x-irradiation

    International Nuclear Information System (INIS)

    Chronister, R.B.; Palmer, G.C.; Gerbrandt, L.

    1980-01-01

    X-irradiation of the rat neonatal hippocampus produces severe alterations in the architectonic features of the mature hippocampus. The most prominent alteration is a marked depletion of the granule cells of the dentate gyrus, with a subsequent realignment of CA 4 cells. The present data also show that norepinephrine (NE), dopamine and histamine stimulation of adenylate cyclase activity is severely attenuated in the hippocampi of irradiated animals. This failure suggests that the NE fibers of irradiated subjects, although normal in content of NE, are not functional in some of their NE-effector actions

  17. Deficit in DNA content relative to histones in X-irradiated HeLa cells

    International Nuclear Information System (INIS)

    Bases, R.; Mendez, F.; Neubort, S.

    1976-01-01

    The DNA and histone content of HeLa S-3 cell cultures was measured by direct mass assays 21 hours after 1000 rad of X-irradiation, when the cells were arrested in G2 phase. The nuclear DNA content of such cultures was found to be deficient (73 per cent of control values). In contrast, the synthesis of nuclear histones persisted, and the total histone content was close to 100 per cent of control values. When synchronously-growing cultures were irradiated in mid-S phase and examined 3.5 hours later in G2 phase, both DNA and histone content were equal to control values. (author)

  18. X-irradiation affects all DNA replication intermediates when inhibiting replication initiation

    International Nuclear Information System (INIS)

    Loenn, U.; Karolinska Hospital, Stockholm

    1982-01-01

    When a human melanoma line was irradiated with 10 Gy, there was, after 30 to 60 min, a gradual reduction in the DNA replication rate. Ten to twelve hours after the irradiation, the DNA replication had returned to near normal rate. The results showed tht low dose-rate X-irradiation inhibits preferentially the formation of small DNA replication intermediates. There is no difference between the inhibition of these replication intermediates formed only in the irradiated cells and those formed also in untreated cells. (U.K.)

  19. Responses to selection for body weight in descendants of x-irradiated rats

    International Nuclear Information System (INIS)

    Gianola, D.; Chapman, A.B.; Rutledge, J.J.

    1979-01-01

    Th effectiveness of selection for high and low body weight at six weeks of age was studied in descendants of x-irradiated (R) and nonirradiated (C) inbred rats. There were two replicates of each of the direction of selection--irradiation treatments. In C lines, there were no consistent responses to selection, probably due to a low level of genetic variability. In R rats, selection was effective only for decreased body weight. The results of this experiment do not suggest the use of irradiation combined with selection as a means of enhancing responses to selection in animals

  20. Epithelial regeneration of transposed intestine after high doses of X-irradiation

    International Nuclear Information System (INIS)

    Both, N.J. de; Vermey, M.

    1976-01-01

    The regeneration capacities of normal and transposed small bowel epithelium were compared in rats after applying high doses of X-irradiation. It has been shown that the potency of the mucosa to regenerate was much higher than assumed and that the mucosa could regenerate after single doses varying from 2000 to 5000 R. Even in the villus epithelium and in flat epithelium covering infiltrates of the lamina propria cells survived, which were still able to resume proliferative activity several days after irradiation. (author)

  1. Preliminary screening of the radiosensitivity-associated genes on colorectal cancer

    International Nuclear Information System (INIS)

    Xing Chungen; Yang Xiaodong; Zhou Liying; Wu Yongyou; Jiang Yinfen; Dai Hong; Lv Xiaodong; Gong Wei

    2007-01-01

    The screening of radiosensitive genes of human colorectal cancer was made by gene chip. Two human colorectal cancer cell lines LOVO and SW480 were cultivated and the total RNA was extracted from at least lxl0 7 cells. Then the gene expression profiling was performed by HG-U133 Plus 2.0 Array and the difference of gene expression has been analyzed. The results shows that there are 16882 genes expressed in LOVO cell and 17114 genes expressed in SW480 cell through gene expression profiling. It has been found that the genes with 2-fold expressed differentially include 908 genes up-regulated and 1312 genes down-regulated. The same genes, such as Fas and NFkB which is up-regulated, Caspas6, and RAD21 which is down-regulated, have been proved to be related to radiosensitivity. The genes with high expression level including CEACAM5, THBS1, SERPINE2, ARL7, HPGD in LOVO cell may also be related to the radiosensitivity. And the genes with high expression level including SCD, NQ01, LYZ, KRT20, ATP1B1 in SW480 cell may be related to the radioresistance of human colorectal cancer. It could be concluded that the radiosensitivity of colorectal cancer can be reflected from gene and protein expression level. And gene expression profiling is a fast and sensitive tool to predict the radiosensitivity and screen radiosensitive genes of colorectal cancer. (authors)

  2. Enterolactone: A novel radiosensitizer for human breast cancer cell lines through impaired DNA repair and increased apoptosis

    International Nuclear Information System (INIS)

    Bigdeli, Bahareh; Goliaei, Bahram; Masoudi-Khoram, Nastaran; Jooyan, Najmeh; Nikoofar, Alireza; Rouhani, Maryam; Haghparast, Abbas; Mamashli, Fatemeh

    2016-01-01

    Introduction: Radiotherapy is a potent treatment against breast cancer, which is the most commonly diagnosed cancer among women. However, the emergence of radioresistance due to increased DNA repair leads to radiotherapeutic failure. Applying polyphenols combined with radiation is a more promising method leading to better survival. Enterolactone, a phytoestrogenic polyphenol, has been reported to inhibit an important radioresistance signaling pathway, therefore we conjectured that enterolactone could enhance radiosensitivity in breast cancer. To assess this hypothesis, radiation response of enterolactone treated MDA-MB-231 and T47D cell lines and corresponding cellular mechanisms were investigated. Methods: Cytotoxicity of enterolactone was measured via MTT assay. Cells were treated with enterolactone before X-irradiation, and clonogenic assay was used to evaluate radiosensitivity. Cell cycle distribution and apoptosis were measured by flow cytometric analysis. In addition, DNA damages and corresponding repair, chromosomal damages, and aberrations were assessed by comet, micronucleus, and cytogenetic assays, respectively. Results: Enterolactone decreased the viability of cells in a concentration- and time dependent manner. Enterolactone significantly enhanced radiosensitivity of cells by abrogating G2/M arrest, impairing DNA repair, and increasing radiation-induced apoptosis. Furthermore, increased chromosomal damages and aberrations were detected in cells treated with enterolactone combined with X-rays than X-ray alone. These effects were more prominent in T47D than MDA-MB-231 cells. Discussion: To our knowledge, this is the first report that enterolactone is a novel radiosensitizer for breast cancer irrespective of estrogen receptor status. Authors propose enterolactone as a candidate for combined therapy to decrease the radiation dose delivered to patients and subsequent side effects. - Highlights: • Enterolactone is proposed to be a novel radiosensitizer for

  3. Enterolactone: A novel radiosensitizer for human breast cancer cell lines through impaired DNA repair and increased apoptosis

    Energy Technology Data Exchange (ETDEWEB)

    Bigdeli, Bahareh, E-mail: bhr.bigdeli@ut.ac.ir [Department of Biophysics, Institute of Biochemistry and Biophysics, University of Tehran, 16th Azar St., Enghelab Sq., Tehran (Iran, Islamic Republic of); Goliaei, Bahram, E-mail: goliaei@ut.ac.ir [Department of Biophysics, Institute of Biochemistry and Biophysics, University of Tehran, 16th Azar St., Enghelab Sq., Tehran (Iran, Islamic Republic of); Masoudi-Khoram, Nastaran, E-mail: n.masoudi@alumni.ut.ac.ir [Department of Biophysics, Institute of Biochemistry and Biophysics, University of Tehran, 16th Azar St., Enghelab Sq., Tehran (Iran, Islamic Republic of); Jooyan, Najmeh, E-mail: n.jooyan@ut.ac.ir [Department of Biophysics, Institute of Biochemistry and Biophysics, University of Tehran, 16th Azar St., Enghelab Sq., Tehran (Iran, Islamic Republic of); Nikoofar, Alireza, E-mail: nikoofar@iums.ac.ir [Department of Radiotherapy, Iran University of Medical Sciences (IUMS), Shahid Hemmat Highway, Tehran (Iran, Islamic Republic of); Rouhani, Maryam, E-mail: rouhani@iasbs.ac.ir [Department of Biological Sciences, Institute for Advanced Studies in Basic Sciences (IASBS), Prof. Yousef Sobouti Blvd., Gava Zang, Zanjan (Iran, Islamic Republic of); Haghparast, Abbas, E-mail: Haghparast@sbmu.ac.ir [Neuroscience Research Center, Shahid Beheshti University of Medical Sciences, Daneshjo St., Evin, Tehran (Iran, Islamic Republic of); Mamashli, Fatemeh, E-mail: mamashli@ut.ac.ir [Department of Biophysics, Institute of Biochemistry and Biophysics, University of Tehran, 16th Azar St., Enghelab Sq., Tehran (Iran, Islamic Republic of)

    2016-12-15

    Introduction: Radiotherapy is a potent treatment against breast cancer, which is the most commonly diagnosed cancer among women. However, the emergence of radioresistance due to increased DNA repair leads to radiotherapeutic failure. Applying polyphenols combined with radiation is a more promising method leading to better survival. Enterolactone, a phytoestrogenic polyphenol, has been reported to inhibit an important radioresistance signaling pathway, therefore we conjectured that enterolactone could enhance radiosensitivity in breast cancer. To assess this hypothesis, radiation response of enterolactone treated MDA-MB-231 and T47D cell lines and corresponding cellular mechanisms were investigated. Methods: Cytotoxicity of enterolactone was measured via MTT assay. Cells were treated with enterolactone before X-irradiation, and clonogenic assay was used to evaluate radiosensitivity. Cell cycle distribution and apoptosis were measured by flow cytometric analysis. In addition, DNA damages and corresponding repair, chromosomal damages, and aberrations were assessed by comet, micronucleus, and cytogenetic assays, respectively. Results: Enterolactone decreased the viability of cells in a concentration- and time dependent manner. Enterolactone significantly enhanced radiosensitivity of cells by abrogating G2/M arrest, impairing DNA repair, and increasing radiation-induced apoptosis. Furthermore, increased chromosomal damages and aberrations were detected in cells treated with enterolactone combined with X-rays than X-ray alone. These effects were more prominent in T47D than MDA-MB-231 cells. Discussion: To our knowledge, this is the first report that enterolactone is a novel radiosensitizer for breast cancer irrespective of estrogen receptor status. Authors propose enterolactone as a candidate for combined therapy to decrease the radiation dose delivered to patients and subsequent side effects. - Highlights: • Enterolactone is proposed to be a novel radiosensitizer for

  4. Metabolic changes after non-lethal X-irradiation of rats. II

    International Nuclear Information System (INIS)

    Ahlers, I.; Ahlersova, E.; Sedlakova, A.; Praslicka, M.

    1981-01-01

    Male rats of the Wistar strain were subjected to whole-body X-irradiation with 2.39 Gy (250 R) and after irradiation they were pair-fed with the sham-irradiated control group. One, 6 and 24 h, 2, 3, 7, 14, 21, 28, and 38 days after exposure the animals were sacrificed and examined for serum and some tissue lipids. In the first hours an increase in lipolysis in the white adipose tissue and accumulation of non-esterified fatty acids and triacylglycerols (TG) in the liver predominated; phospholipid level increased in serum and liver and decreased in bone marrow and thymus. The later phase was characterized by hypertriacylglycerolaemia and a transient hypercholesterolaemia; accumulation of TG in bone marrow was the most important change, however. Changes in the lipid composition of the serum and tissues, except for an increase in TG level in thymus, returned to normal levels at the end of the observation period. Pair-feeding provided an equivalent nutritional situation in irradiated and sham-irradiated animals and thus eliminated the non-specific changes caused by different levels of food intake in both groups of animals, especially in the initial period. A sufficiently long observation period is necessary for estimating the kinetics of metabolic changes in rats exposed to non-lethal doses of X-irradiation. (author)

  5. Intestinal metaplasia induced by x-irradiation in different strains of rats

    International Nuclear Information System (INIS)

    Watanabe, Hiromitsu; Naito, Masashi; Kawashima, Kengo; Ito, Akihiro

    1985-01-01

    Attempts were made to examine strain differences in the susceptibility of rats to intestinal metaplasia induced by X-irradiation. The gastric regions of 4 inbred male rats (SHR, F344, WKY, and LEW strains) in 5-week-old and 2 random bred male rats (SD, and WIS strains) were irradiated with a total dose of 20 Gy X-ray given in two equal fractions separated by three days. Upon sacrifice at 6 months after the last irradiation, the number of intestinal metaplastic crypts with positive reaction to alkaline phosphatase (ALP) appeared highest in the SHR and lowest in the WIS rats. Morphologically, the number of crypts with intestinal metaplasia in whole glandular stomachs of SHR, WIS, F344, and SD rats were higher than those in WKY and LEW rats. In the pyloric gland, it was highest in WIS rats, while in the fundic gland it was highest in SHR rats. The results show that the appearance and location of intestinal metaplasia by X-irradiation are greatly influenced by the strain of the rat. (author)

  6. BCR-ABL fusion genes are inducible by X-irradiation in vitro

    International Nuclear Information System (INIS)

    Ito, Takashi; Seyama, Toshio; Mizuno, Terumi; Hayashi, Tomonori; Nakamura, Nori; Akiyama, Mitoshi; Dohi, Kiyohiko.

    1992-01-01

    The Philadelphia chromosome consists of a reciprocal translocation between the ABL oncogene at chromosome 9q34 and the BCR gene at chromosome 22q resulting in the expression of chimeric BCR-ABL mRNAs specific to chronic myelogenous leukemia (CML). The presence of the fusion genes can be detected with high specificity and sensitivity by means of reverse transcription and polymerase chain reaction. Using this assay, it was possible to detect BCR-ABL fusion genes induced among HL60 cells after 100 Gy of X-irradiation in vitro. A total of five fusion gene transcripts were obtained. These fusion genes contained not only CML-specific BCR-ABL rearrangements, but also other forms of BCR-ABL fusions. These latter genes had junctions of BCR exon 4/ABL exon 2 intervened by a segment of DNA of unknown origin, BCR exon 5/ABL exon 2, and BCR exon 4/ABL exon 2. The results appear to be the first evidence for the induction of the BCR-ABL fusion gene by X-irradiation. In terms of leukemogenesis, it is suggested that only those cells bearing certain CML-related BCR-ABL fusion genes are positively selected by virtue of a growth advantage in vivo. (author)

  7. Ontogenetic changes in the ultrastructure of rat hepatocyte organelles after prenatal x irradiation

    International Nuclear Information System (INIS)

    Chedid, A.; Nair, V.

    1975-01-01

    The effects of prenatal x irradiation on the development of hepatocyte organelles have been studied in Sprague-Dawley rats. Pregnant rats received 50 R to the pelvic region on the 13th gestation day (g.d.). Animals were sacrificed on g.d.'s 15 and 20, day of birth, and 5th postnatal day. The fetal and neonatal livers were obtained and processed for electron-microscopic examination. The most striking discernible change after irradiation involves the appearance of cytoplasmic ''polyribosomal aggregates'' in the hepatocyte specimens of 15th and 20th g.d.'s. In the control rat, smooth endoplasmic reticulum (SER) appears for the first time on 20th g.d., while no SER could be detected in the hepatocytes from the irradiated animals at this period nor on day of birth. In the irradiated animals, SER was observed on the 5th postnatal day. Our results are consistent with the hypothesis that lipid peroxidation membrane alteration, delayed appearance of SER, and ''polyribosomal aggregation'' may be sequentially linked events after prenatal x irradiation. (U.S.)

  8. Adaptive response of the chicken embryo to low doses of x-irradiation

    International Nuclear Information System (INIS)

    Tempel, K.; Schleifer, S.

    1995-01-01

    Chicken embryos were x-irradiated in ovo with 5-30 cGy (=priming dose) at the 13th-15th day of development. After 3-48 h, brain- and liver-cell suspensions were x-irradiated in vitro with (challenge) doses of 4-32 Gy. Significantly less radiation damage was observed when the radiation response was measured by scheduled DNA synthesis, nucleoid sedimentation and viscosity of alkaline cell lysates 12-36 h after the priming exposure. In vivo, pre-irradiation with 10 cGy enhanced regeneration as evidenced by the DNA content of chicken embryo brain and liver 24 h following a challenge dose of 4 Gy. From nucleoid sedimentation analyses in brain and liver cells immediately after irradiation with 16 Gy and after a 30-min repair period in the presence of aphidicolin, dideoxythymidine and 3-aminobenzamide or in the absence of these DNA repair inhibitors, it is concluded that a reduction of the initial radiation damage is the dominant mechanism of the ''radio-adaptive'' response of the chicken embryo. Sedimentation of nucleoids from ethidium bromide (EB) (0.75-400 μg/ml)-treated cells suggests a higher tendency of ''radio-adapted'' cells to undergo positive DNA supercoiling in the presence of high EB concentrations. (orig.)

  9. The effects of x-irradiation in the mosquito Aedes aegypti (L)

    International Nuclear Information System (INIS)

    Read, N.G.

    1980-01-01

    Newly emerged mosquitoes (Aedes aegypti (L)) were exposed to doses of 500 to 32,000 rad X-irradiation and the LD 50 and mean survival time determined. Radiation doses between 500 and 8,000 rad had only a slight effect on longevity whereas exposure to 32,000 had an appreciable effect. The midgut structure of newly emerged, X-irradiated female Aedes aegypti imagines was examined at set intervals after irradiation. The cytochemical localization of midgut acid phosphatase, alkaline phosphatase and adenosine triphosphatase, and also quantitative estimates of midgut acid and alkaline phosphatase were carried out on mosquitoes exposed to 32,000 rad. Considerable changes in the structure of the midgut cells were apparent. With 500, 4,000 and 8,000 rad there was evidence of cellular repair and recovery. However, with 32,000 rad cellular damage was most extensive, with considerable loss of cell structure. The ultrastructural changes noted suggest that the primary radiation damage was to the plasma and organelle membranes, which is in agreement with the membrane-damage/enzyme release hypothesis. (author)

  10. Effects of x irradiation on estrogen-induced synthetic processes of the avian liver

    International Nuclear Information System (INIS)

    Holshouser, S.J.; Schjeide, O.A.; Briles, W.E.

    1975-01-01

    Effects of x irradiation on protein and lipid synthesis were studied, using estrogen-induced yolk protein syntheses by the avian liver as a test model. Female chickens, receiving a single sublethal whole-body exposure of 600 R of x irradiation at 5 wk of age, laid fewer and smaller eggs upon reaching maturity as compared to nonirradiated controls. However, chemical contents and ultracentrifuge patterns of yolk proteins were not found to be qualitatively different. Accordingly, the synthesis of no one major yolk protein appeared to be selectively inhibited by exposure of the bird to irradiation. Injection of Estrogenic Substances into hens over a period of 3 days resulted in a much greater enlargement of livers in control estrogenized birds than in irradiated estrogenized birds. Differences were also ascertained to exist between control and irradiated birds in terms of total liver RNA. This would seem to indicate a greater potential for synthesis of serum yolk protein precursors in nonirradiated estrogenized hens. (U.S.)

  11. Characterization through a data display of the different cellular responses in X-irradiated small intestine

    International Nuclear Information System (INIS)

    Carr, K.E.; McCullough, J.S.; Nelson, A.C.; Hume, S.P.

    1992-01-01

    Previous work on small intestinal radiation injury has reported changes in epithelial and non-epithelial tissues, but with few quantitative comparisons of different responses by individual cell types. The approach used here quantifies the responses of mouse duodenum to X-irradiation with 6 Gy, 10 Gy and 20 Gy, sampled three days after treatment, and 10 Gy sampled 6 hours, 1 day and 3 days after treatment. Tissue area measurements and counts per circumference for 13 different structural elements are subjected to statistical tests. New data reported here for X-irradiation include the fact that cryptal cells do not respond uniformly, indicating that the crypt/microcolony cannot always be used as a standard unit in assessing radiation injury. Non-epithelial structures, such as submucosal arterioles, are also affected. The data display also includes control-referenced ratios, from which are calculated Tissue Indices and a final Morphological Index, which estimates total structural damage. The Indices are useful in drawing attention to unexpected changes in extent or range of data sets. In addition, the Epithelial Index appears to be a sensitive indicator of radiation damage, even at low doses and early time points. The data display includes a graph of the total Indices and summary tables of data, and encourages close study of the constituent data points. (author)

  12. Vaccination against bovine schistosomiasis japonica with highly X-irradiated schistosomula

    International Nuclear Information System (INIS)

    Hsue, S.Y.; Hsue, H.F.; Xu, S.T.; Shi, F.H.; He, Y.X.; Clarke, W.R.; Johnson, S.C.

    1983-01-01

    Cercariae of the Chinese mainland strain of Schistosoma japonicum were used. Eighteen cattle, divided into six groups of three each, were immunized with schistosomula transformed from cercariae exposed to three different doses of X-irradiation (24, 36, and 48 kR). The immunization was given either once, twice, or thrice, and the number of immunizing schistosomula was 10,000 or more in each immunization. The immunized cattle were challenged with 500 normal cercariae. Five native cattle were similarly infected with normal cercariae as controls. All cattle were killed 32-33 days after challenge or infection, and the worms were obtained by perfusion. The mean worm reduction in the 18 experimental animals varied from 42.1 to 96.0%. The mean percent worm reduction of the six experimental groups varied from 54.8 to 87.1. The reduction was greater with increasing numbers of immunizations, and was higher in the groups immunized with schistosomula exposed to 36 kR than in those exposed to 24 or 48 kR. Statistical analyses showed that all immunized groups yielded significantly fewer worms than controls. However, the three doses of X-irradiation (24, 36, and 48 kR) had no significant effect for a fixed number of immunizations (1, 2, or 3). The means for both two and three immunizations were significantly different from the mean for one immunization, although they were not significantly different from each other

  13. Changes in nucleoid viscosity following X-irradiation of rat thymic and splenic cells in vitro

    International Nuclear Information System (INIS)

    Tempel, K.

    1990-01-01

    In the present investigations, damage and repair of DNA supercoiling was measured in T- and S-cells following X-irradiation in vitro by using the nucleoid sedimentation technique and a simplified low-shearing viscometric test. - X-irradiation resulted in a dose(0.6-19.2 Gy)-dependent reduction in sedimentation and viscosity of nucleoids. Within a post-irradiation period of 30-45 min after a challenge dose of 19.2 Gy, DNA repair was accompanied by an increase in nucleoid sedimentation and viscosity in T-cells by about 60 and 300, in S-cells by almost 40 and 100%, resp. The increase in nucleoid viscosity within a 30 min repair period could be reduced in a concentration-dependent manner by DNA polymerase-inhibitors and proteinase K. - The higher DNA repair capacity of T-cells as reflected by UDS is confirmed therefore by the nucleoid characteristics. A part from this suggestion, measuring nucleoid viscosity may be considered as a sensitive, simple and rapid device to detect radiation-induced DNA supercoiling phenomena. (orig./MG)

  14. Entire litters developed from transferred eggs in whole body x-irradiated female mice

    International Nuclear Information System (INIS)

    Lin, T.P.

    1980-01-01

    The sensitivity of mouse eggs to sublethal x-irradiation was determined in vitro and in vivo with regard to the development of donor litters in foster mothers. One thousand seven hundred fifty-eight unfertilized eggs of agouti dark-eyed donor mice were transferred into 293 unirradiated or x-irradiated, mated female pink-eyed mice. Two hundred thirty-nine recipients became pregnant; of these 35 produced litters containing solely dark-eyed fetuses. Sublethal doses of x-radiation administered to donor eggs in vitro before transferring into unirradiated recipients did not influence significantly the number of litters of exclusively dark-eyed fetuses produced. However, recipients irradiated by 250 roentgens (r) produced more solely dark-eyed litters than did those irradiated with 100 r. In 21 pregnant females irradiated by 100 r, only 3 (14%) developed solely dark-eyed fetuses as compared to 22 pregnant females irradiated by 250 r, of which 13 (59%) developed solely dark-eyed fetuses, all from unirradiated, transferred eggs. Of another group of 22 pregnant females which received 250 r body irradiation and subsequently received eggs also irradiated by 250 r, only 7 (32%) produced litters of dark-eyed fetuses. No one female of these three groups carried native fetuses. Such radiation-induced infertility resulting from damage of native eggs rather than loss of mother's ability to carry a pregnancy, is frequently remedied by egg transfer

  15. Apoptosis in the chicken bursa of fabricius induced by X-irradiation.

    Science.gov (United States)

    Arai, S; Kowada, T; Takehana, K; Miyoshi, K; Nakanishi, Y H; Hayashi, M

    1996-10-01

    Immature B lymphocytes in the chicken bursa of Fabricius have previously been reported to undergo apoptosis by low doses of ionizing radiation. In the present study, newly hatched chickens were subjected to whole-body X-irradiation, and the bursa of Fabricius was examined at various postirradiation times by light and electron microscopy to obtain information on the change of ultrastructure of irradiated bursal cells as well as on the time course and dose-response for the induction of apoptosis. Histological examination by light microscopy showed that pyknotic cells started to increase in the bursa within a few hours after irradiation and the frequency of occurrence reached a maximum at 6 hr. An evident increase of the pyknotic cells in number was observed at a dose of as little as 1 Gy, and the frequency increased with increases in the dose, reaching over 90% at 15 Gy. Electron microscopy of the irradiated bursa revealed typical apoptotic morphology such as chromatin condensation, nuclear fragmentation, formation of apoptotic bodies and phagocytosis of pyknotic cells. Induction of apoptosis was also confirmed by the appearance of a typical DNA ladder pattern on agarose gel. Thus, the present results demonstrate that the chicken bursal cells are hypersensitive to X-irradiation with regard to induction of apoptosis, and that the apoptotic bursal cells exhibit most of the ultrastructural features known to be typical of apoptosis.

  16. Response of resting L5178Y-S and L5178Y-R cells with different radiosensitivity to radiation and hydroxyurea

    International Nuclear Information System (INIS)

    Afanas'ev, G.G.; Shumel', I.; Valitska, M.; Nekokojchitska, Eh.; Beer, Ya. Z.; Pelevina, I.I.

    1981-01-01

    A study was made of cloning capacity of radiosensitive L5178YS and radioresjstant L5J78YR cells of mouse leukaemia suspension culture after X-irradiation and postradiation treatment with hydroxyurea at 37 deg and 34 deg C. It was shown that both cell lines possess a good cloning capacity at the stationary phase of growth; they are more radiosensitive than cells at the logarithmic phase of growth and cannot repair potentially lethal damages either after decreasing the temperature or the administration of h droxyurea. The postradiation treatment with hydroxyurea enhances the effect of radiation by 2 times in the case of R cells, and by 2 and 1.3 times, depending on the incubation temperature, in the case of S cells

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

    International Nuclear Information System (INIS)

    Prusek, W.; Astaldi, G.

    1979-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1979-01-01

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

  19. Radiosensitivity of lymphocytes among Filipinos: final report

    International Nuclear Information System (INIS)

    Medina, F.I.S.; Gregorio, J.S.; Aguilar, C.P.; Poblete, E.E.

    1996-01-01

    This report is about the studies on the radiosensitivity of Filipino lymphocytes to radiation that can elucidate on the potential of blood chromosomes as biological dosimeters. The objective of this study is to determine the radiosensitivity of lymphocytes among Filipinos and to establish the radiation-induced chromosome anomaly standard curve in lymphocytes for radiological dosimetry. 47 refs., 9 figs., 1 tab

  20. Effects of hyperthermia and x irradiation on sister chromatid exchange (SCE) frequency in Chinese hamster ovary (CHO) cells

    International Nuclear Information System (INIS)

    Livingston, G.K.; Dethlefsen, L.A.

    1979-01-01

    The BrdUrd labeling method was used to evaluate the effects of hyperthermia, x irradiation, and the combined treatment on the incidence of sister chromatid exchange (SCE) in Chinese hamster ovary (CHO) cells. Cells cultured in McCoy's 5A media containing 10 μM 5-bromodeoxyuridine were synchronized after one cell cycle by mitotic shake-off. Early-G 1 cells were heated by submerging culture flasks in a 44 +- 0.05 0 C water bath for periods of 20, 40, and 60 min. By the same method, other cultures were x irradiated at doses of 100, 200, 400, and 600 rad. A third protocol involved combined treatment of 20 min at 44 0 C followed immediately by one of the above radiation doses. A fourth protocol reversed the sequence of the combined treatment applying x irradiation (200 or 400 rad) followed immediately by hyperthermia. The data showed that hyperthermia and x irradiation both elevated the frequency of SCEs significantly whether applied separately or together. The combined treatment (heat: 20 min at 44 0 C plus varying x-radiation doses) produced results suggestive of a synergistic interaction. The sequence of the heat and x irradiation did not appear to have a significant effect on the production of SCE

  1. Radiosensitivity of mesothelioma cell lines

    International Nuclear Information System (INIS)

    Haekkinen, A.M.; Laasonen, A.; Linnainmaa, K.; Mattson, K.; Pyrhoenen, S.

    1996-01-01

    The present study was carried out in order to examine the radiosensitivity of malignant pleural mesothelioma cell lines. Cell kinetics, radiation-induced delay of the cell cycle and DNA ploidy of the cell lines were also determined. For comparison an HeLa and a human foetal fibroblast cell line were simultaneously explored. Six previously cytogenetically and histologically characterized mesothelioma tumor cell lines were applied. A rapid tiazolyl blue microtiter (MTT) assay was used to analyze radiosensitivity and cell kinetics and DNA ploidy of the cultured cells were determined by flow cytometry. The survival fraction after a dose of 2 Gy (SF2), parameters α and β of the linear quadratic model (LQ-model) and mean inactivation dose (D MID ) were also estimated. The DNA index of four cell lines equaled 1.0 and two cell lines equaled 1.5 and 1.6. Different mesothelioma cell lines showed a great variation in radiosensitivity. Mean survival fraction after a radiation dose of 2 Gy (SF2) was 0.60 and ranged from 0.36 to 0.81 and mean α value was 0.26 (range 0.48-0.083). The SF2 of the most sensitive diploid mesothelioma cell line was 0.36: Less than that of the foetal fibroblast cell line (0.49). The survival fractions (0.81 and 0.74) of the two most resistant cell lines, which also were aneuploid, were equal to that of the HeLa cell line (0.78). The α/β ratios of the most sensitive cell lines were almost an order of magnitude greater than those of the two most resistant cell lines. Radiation-induced delay of the most resistant aneuploid cell line was similar to that of HeLa cells but in the most sensitive (diploid cells) there was practically no entry into the G1 phase following the 2 Gy radiation dose during 36 h. (orig.)

  2. Isolation and characterization of a radiosensitive Chinese hamster ovary cell line

    International Nuclear Information System (INIS)

    Fuller, L.F.

    1987-01-01

    A x-ray sensitive Chinese hamster ovary cell line was isolated using a semi-automated procedure in which mutagenized CHO cells were allowed to form colonies on top of agar, x-irradiated, then photographed at two later times. Comparison of the photographs allowed the identification of colonies which displayed significant growth arrest. One of the colonies identified in this manner produced a stable, radiosensitive line. This cell line is normal in x-ray induced inhibition of DNA synthesis, and single- and double-strand break repair, and is moderately sensitive to ethyl methane sulfonate and UV light. The sensitive line performs only half as much x-ray-induced repair replication as the parental line and this deficiency is believed to be the primary cause of its radiosensitivity. The sensitive line produces significantly higher numbers of x-ray-induced chromosome and chromatid aberrations including chromatid aberrations following exposure during the G 1 phase of the cell cycle. The line is hypomutable compared to the parental line with x-ray exposure inducing only one-third as many 6-thioguanine resistant colonies

  3. Effect of sanguinarine on the growth and radiosensitivity of human ovarian cancer cells

    International Nuclear Information System (INIS)

    Xu Jiaying; Ji Junmin; Jiao Yang; Wu Li; Fan Sanjun

    2012-01-01

    Objective: To study the effect of sanguinarine on the growth and radiosensitivity of ovarian cancer SK-OV-3 cells. Methods: Cell growth was determined by MTT and clonogenic assay. Cell cycle analysis was performed by flow cytometry assay. The cell apoptosis was analyzed by Annexin V/PI assay. Results: Sanguinarine inhibited SK-OV-3 cell growth in a dose-and time-dependent fashion and its IC 50 values were 3.02 and 1.11 μmol/L at 24 and 48 h, respectively. Sanguinarine also significantly triggered a sub-G 1 peak, an indicator of apoptosis,and caused a G 0 /G 1 arrest. Furthermore, the cell apoptosis induced by X-irradiation was significantly increased at 6 Gy when the cells were pre-treated with sanguinarine, in which the early apoptotic population increased from 10.28% to 43.28% (t=19.41, P<0.01) and the late apoptotic population increased from 20.26% to 30.80% (t=8.78, P<0.01). The multi-target click model was used to fit survival curves and the SER of sanguinarine treatment approached to 1.625 at the dose of D 0 . Conclusions: Sanguinarine could inhibit SK-OV-3 cell growth by inducing apoptosis and cell cycle arrest and enhance cell radiosensitivity at low doses. (authors)

  4. Induction of DNA breakage in X-irradiated nucleoids selectively stripped of nuclear proteins in two mouse lymphoma cell lines differing in radiosensitivity

    International Nuclear Information System (INIS)

    Kruszewski, M.; Iwanenko, T.

    1998-01-01

    The role of nuclear proteins in protection of DNA against ionizing radiation and their contribution to the radiation sensitivity was examined by an alkaline version of comet assay in two L5178Y (LY) mouse lymphoma cell lines differing in sensitivity t o ionizing radiation. LY-S cells are twice more sensitive to ionizing radiation than LY-R cells (D 0 values of survival curves are 0.5 Gy and 1 Gy, respectively). Sequential removal of nuclear proteins by extraction with NaCl of different concentrations increased the X-ray induced DNA damage in LY-R nucleoids. In contrast, in the radiation sensitive LY-S cell line, depletion of nuclear proteins practically did not affect DNA damage. Although there is no doubt that the main cause of LY-S cells' sensitivity to ionizing radiation is a defect in the repair of double-strand breaks, our data support the concept that nuclear matrix organization may contribute to the cellular susceptibility to DNA damaging agents. (author)

  5. Attempts at immunization against Malayan filariasis using X-irradiated infective larvae

    International Nuclear Information System (INIS)

    Ramachandran, C.P.

    1975-01-01

    Recent studies on immunity to helminthic infections have shown that some degree of protective immunity may be stimulated by inoculations of attenuated living worms or their metabolites. Although much on these lines has been done with several helminths, little if any has been done with filarial infections in general. Experiments were designed to observe the effects of attempted immunization in the rhesus monkey as well as the domestic cat by the use of attenuated infective larvae of Brugia malayi. The sub-periodic strain of Brugia malayi, the major filarial parasite of man in Malaysia, maintained in the laboratory on experimentally infected cats and rhesus monkeys were used for the preparation of X-irradiated vaccines as well as for challenge inoculations. Third-stage infective larvae of Brugia malayi were obtained from experimentally fed Aedes togoi mosquitoes. Infective larvae were irradiated by X-rays, using a Dermopan X-ray unit at exposures between 10 - 40 kR. Rhesus monkeys and cats were inoculated twice with 100 - 400 attenuated larvae per inoculation at 2 week intervals and challenged about a month later by inoculation of 100 normal larvae. Control animals for each vaccination dose as well as for challenge doses were maintained. In rhesus monkeys persistent immunity to challenge infections (expressed as failure to cause microfilaraemia) were obtained in animals vaccinated with 200 infective larvae attenuated by X-irradiation at 20000 R. Encouraged with the results obtained on rhesus monkeys, similar experiments on an enlarged scale using varying strengths of the vaccines were carried out on the domestic cat, which is a more receptive animal host for Brugia malayi. However, all cats vaccinated when challenged came down with patent infection indicating lack of any definite immunity. In all these experiments, results of vaccine control animals showed that inoculation of irradiated larvae was not followed by the infection of microfilaria in the blood, indicating

  6. Different mechanisms between premitotic apoptosis and postmitotic apoptosis in X-irradiated U937 cells

    International Nuclear Information System (INIS)

    Shinomiya, Nariyoshi; Kuno, Yukie; Yamamoto, Fuyumi; Fukasawa, Masashi; Okumura, Atsushi; Uefuji, Megumi; Rokutanda, Makoto

    2000-01-01

    Purpose: Apoptosis is currently being evaluated for its importance as a pathway of radiation-induced cell death. However, the difference in the mechanisms between premitotic and postmitotic apoptosis following X-irradiation remains not well understood. We show here that the human monoblastoid cell line U937 can be induced to undergo these two different types of apoptosis. Methods and Materials: U937 cells were irradiated at a dose of 5 or 20 Gy, and the DNA fragmentation rate was measured by both flow cytometric analysis and gel electrophoresis. Activation of caspase-3 was detected by Western blot analysis and fluorogenic assay using acetyl-Asp-Glu-Val-Asp-7-amino-4-methyl-coumarin (Ac-DEVD-AMC). Detection of mitochondrial transmembrane potential (no. DELTAno. no. PSIno. ) was performed by using Rho123. Chasing of S-phase fraction following X-irradiation was performed after labeling with 5-bromo-2'-deoxyuridine (BrdU). Thymidine was used for synchronization of the cells. Inhibition of caspase-3 activity was achieved by Acetyl-Asp-Glu-Val-Asp-aldehyde (Ac-DEVD-CHO). Results: Time courses of the apoptotic rates, caspase activation, and no. DELTAno. no. PSIno. indicated that two different types of cell death were induced by the different X-ray doses. High-dose X-ray (20 Gy) induced a rapid and strong apoptosis, whereas low-dose X-ray (5 Gy) induced a slow and mild apoptosis. Cell-cycle analyses revealed that there was cell death before cell division in the former apoptosis but the cells must be dying after cell division in the latter apoptosis. By means of cell-cycle synchronization, the S-phase cells proved to be the most sensitive fraction to premitotic apoptosis, but an obvious difference in the susceptibility to cell death among the cell-cycle phases was not observed in postmitotic apoptosis. Ac-DEVD-CHO treatment effectively blocked caspase activity and premitotic apoptosis, but it failed to block postmitotic apoptosis. Conclusions: Irradiation of U937 cells at

  7. 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)

  8. Effect of low dose x irradiation on the succinate dehydrogenase activity of guinea pig, rat and mouse tissues

    Energy Technology Data Exchange (ETDEWEB)

    Shah, V C; Bhatavdekar, J M; Aravinda Babu, K [Gujarat Univ., Ahmedabad (India). Dept. of Zoology

    1976-07-01

    The histochemical changes in succinate dehydrogenase (SDH) were investigated in pectoralis major muscle of guinea pig, rat and mouse after level X-irradiation (72 R and 240 R) and compared with control animals. Biochemical studies were carried out on liver, kidney, muscle (pectoralis major), adrenal and spleen of these animals after low dose local X-irradiation and compared with control animals. Changes in SDH activity were studied up to 72-h post-irradiation, which shows that low dose local X-irradiation leads to increased enzymic activity. The increase in enzymic activity was remarkable in mouse tissues as compared with guinea pig and rat. Adrenals of all the three animals showed significant activation after all the doses of radiation studied. The significance of these results, with special reference to oxidative metabolism, has been discussed.

  9. Radiosensitivity of soft tissue sarcomas

    International Nuclear Information System (INIS)

    Hirano, Toru; Iwasaki, Katsuro; Suzuki, Ryohei; Monzen, Yoshio; Hombo, Zenichiro

    1989-01-01

    The correlation between the effectiveness of radiation therapy and the histology of soft tissue sarcomas was investigated. Of 31 cases with a soft tissue sarcoma of an extremity treated by conservative surgery and postoperative radiation of 3,000-6,000 cGy, local recurrence occurred in 12; 5 out of 7 synovial sarcomas, 4 of 9 MFH, one of 8 liposarcomas, none of 4 rhabdomyosarcomas and 2 of 3 others. As for the histological subtyping, the 31 soft tissue sarcomas were divided into spindle cell, pleomorphic cell, myxoid and round cell type, and recurrence rates were 75%, 33.3%, 16.7% and 0%, respectively. From the remarkable difference in recurrent rate, it was suggested that round cell and myxoid type of soft tissue sarcomas showed a high radiosensitivity compared to the spindle cell type with low sensitivity. Clarifying the degree of radiosensitivity is helpful in deciding on the management of limb salvage in soft tissue sarcomas of an extremity. (author)

  10. Hyperthermic radiosensitization of synchronous Chinese hamster cells: relationship between lethality and chromosomal aberrations

    International Nuclear Information System (INIS)

    Dewey, W.C.; Sapareto, S.A.; Betten, D.A.

    1978-01-01

    Synchronous Chinese hamster cells in vitro were obtained by mitotic selection. The cells were heated at 45.5 0 C for 4 min in mitosis, 11 min in G 1 , or 7 min in S sphase and then x-irradiated immediately thereafter. Colony survival from heat alone was 0.30 to 0.45, and the frequency of chromosomal aberrations induced by heat was 0.00, 0.14, or 0.97 for heat treatments during M, G 1 , or S, respectively. As shown previously, lethality from hyperthermia alone is due to chromosomal aberrations only when the cells are heated during S phase. The log survival (D 0 /sup approximately/ = 80 rad) and aberration frequency curves for cells irradiated during mitosis were linear, and the only effect of hyperthermia was to shift the curves in accord with the effect from heat alone. Thus, hyperthermia did not radiosensitize the mitotic cells. The cells irradiated in G 1 were more resistant (D 0 /sup approximately/ = 100 rad) than those irradiated in mitosis, and the survival and aberration frequency curves both had shoulders. The primary effect of hyperthermia was to greatly reduce the shoulders of the curves and to increase the slopes by about 23%. The cells irradiated in S were the most resistant (D 0 /sup approximately/ = 140 rad), and the survival and aberration frequency curves both had large shoulders. For both end points of lethality and chromosomal aberrations, heat selectively radiosensitized S-phase cells relative to G 1 cells by removing most of the shoulder and increasing the slope by about 45%. For cells treated in G 1 or S, the increase in radiosensitization following hyperthermia can be accounted for by an increase in the frequency of chromosomal aberrations

  11. Effects of X-irradiation on N-methyl-N-nitrosourea-induced multi-organ carcinogenesis in rats

    International Nuclear Information System (INIS)

    Morishita, Yukiko; Tanaka, Takuji; Mori, Hideki; Sasaki, Shunsaku.

    1993-01-01

    The effects of X-irradiation on N-methyl-N-nitrosourea (MNU)-induced multi-organ carcinogenesis were examined in both sexes of ACI/N rats. At 6 weeks of age, rats in groups 1 (25 males, 25 females) and 3 (24 males, 23 females) received a single intraperitoneal injection of MNU (25 mg/kg body weight), while those in groups 2 (25 males, 26 females) and 4 (25 males, 25 females) were administered the carcinogen at a dose of 50 mg/kg body weight. At 10 weeks of age, group 3 and group 4 were X-irradiated at dose of 3 Gy. Group 5 (24 males, 24 females) received X-irradiation alone. Group 6 (21 males, 21 females) served as an untreated control. As a result, neoplasms developed mainly in the digestive tract, kidney, uterus, and hematopoietic organ in groups 1-5. The incidences of adenocarcinoma in small and large intestines of male rats of group 4 (50 mg/kg MNU and X-irradiation) (small intestine: 48%, large intestine: 32%) were significantly higher than those of group 2 (50 mg/kg MNU) (small intestine: 17%, p<0.05; large intestine: 8%, p<0.05), and also the frequency of adenocarcinoma in the large intestine of males of group 3 (25 mg/kg MNU and X-irradiation) (22%) was significantly greater than that of group 1 (25 mg/kg MNU) (0%, p<0.05). These results indicated that X-irradiation enhanced the development of intestinal neoplasms induced by MNU in male ACI/N rats. (author)

  12. Effects of X-irradiation on N-methyl-N-nitrosourea-induced multi-organ carcinogenesis in rats

    Energy Technology Data Exchange (ETDEWEB)

    Morishita, Yukiko; Tanaka, Takuji; Mori, Hideki (Gifu Univ. (Japan). Faculty of Medicine); Sasaki, Shunsaku

    1993-01-01

    The effects of X-irradiation on N-methyl-N-nitrosourea (MNU)-induced multi-organ carcinogenesis were examined in both sexes of ACI/N rats. At 6 weeks of age, rats in groups 1 (25 males, 25 females) and 3 (24 males, 23 females) received a single intraperitoneal injection of MNU (25 mg/kg body weight), while those in groups 2 (25 males, 26 females) and 4 (25 males, 25 females) were administered the carcinogen at a dose of 50 mg/kg body weight. At 10 weeks of age, group 3 and group 4 were X-irradiated at dose of 3 Gy. Group 5 (24 males, 24 females) received X-irradiation alone. Group 6 (21 males, 21 females) served as an untreated control. As a result, neoplasms developed mainly in the digestive tract, kidney, uterus, and hematopoietic organ in groups 1-5. The incidences of adenocarcinoma in small and large intestines of male rats of group 4 (50 mg/kg MNU and X-irradiation) (small intestine: 48%, large intestine: 32%) were significantly higher than those of group 2 (50 mg/kg MNU) (small intestine: 17%, p<0.05; large intestine: 8%, p<0.05), and also the frequency of adenocarcinoma in the large intestine of males of group 3 (25 mg/kg MNU and X-irradiation) (22%) was significantly greater than that of group 1 (25 mg/kg MNU) (0%, p<0.05). These results indicated that X-irradiation enhanced the development of intestinal neoplasms induced by MNU in male ACI/N rats. (author).

  13. Glyoxylic compounds as radiosensitizers of hypoxic cells

    International Nuclear Information System (INIS)

    Cornago, M.P.; Lopez Zumel, M.C.; Alvarez, M.V.; Izquierdo, M.C.

    1990-01-01

    The radiosensitizing effect of five glyoxal derivatives on the survival of TC-SV40 cells has been measured, under aerobic and hypoxic conditions. A toxicity study was previously performed in order to use nontoxic concentrations. The OER for the TC-SV40 cells was 2.74. None of the glyoxylic compounds showed radiosensitizing activity under aerobic conditions while in hypoxia their radiosensitizing factors decreased in the order phenylglyoxylic acid (1.68 at 8 x 10(-3) mole dm-3) greater than phenylglyoxal (1.55 at 5 x 10(-6) mole dm-3) greater than 2-2' furil (1.48 at 5 x 10(-5) mole dm-3) greater than glyoxylic acid (1.39 at 1 x 10(-3) mole dm-3) greater than glyoxal (1.30 at 5 x 10(-5) mole dm-3). The dose-modifying factors were also determined at two equimolar concentrations 5 x 10(-5) and 5 x 10(-6) mole dm-3. A concentration effect was noticed for all the compounds although their relative radiosensitizing activity kept, independently of the concentration, the same order noted above. Glyoxals with aromatic or heterocyclic rings exert a greater radiosensitization than the others. The acidic compounds have less radiosensitizing activity than their aldehydic counterparts. Interaction of these glyoxals with NPSH cellular groups was tested and the low degree of inhibition shows that this mechanism would contribute very little, if any, to the radiosensitization effect

  14. Influence of x-irradiation on pharyngeal induction in the Planarian, Dugesia japonica japonica

    International Nuclear Information System (INIS)

    Asai, Etsuo

    1980-01-01

    Pharyngeal formation was examined in cases where normal or X-irradiated head pieces were transplanted into the postpharyngeal region of normal or irradiated worms. Transplantation experiments were carried out in four different combinations of hosts and grafts: (1) normal host and graft (control), (2) normal host and irradiated graft, (3) irradiated host and normal graft, (4) irradiated host and graft. In the first experiment, well developed pharynges were formed in the areas both anterior and posterior to the graft on the 14th day after transplantation. In the second experiment, formation of new pharynges was delayed compared with that in the first group. In the third experiment, only one pharynx developed in the area posterior to each graft in most cases. In the last experiment, no new pharynx appeared at all. From these results, the influence of X-rays on factors participating in pharyngeal induction was discussed. (author)

  15. Effects of X-irradiation on artificial blood vessel wall degradation by invasive tumor cells

    International Nuclear Information System (INIS)

    Heisel, M.A.; Laug, W.E.; Stowe, S.M.; Jones, P.A.

    1984-01-01

    Artificial vessel wall cultures, constructed by growing arterial endothelial cells on preformed layers of rat smooth muscle cells, were used to evaluate the effects of X-irradiation on tumor cell-induced tissue degradation. Bovine endothelial cells had radiation sensitivities similar to those of rat smooth muscle cells. Preirradiation of smooth muscle cells, before the addition of human fibrosarcoma (HT 1080) cells, did not increase the rate of degradation and destruction by the invasive cells. However, the degradation rate was decreased if the cultures were irradiated after the addition of HT 1080 cells. The presence of bovine endothelial cells markedly inhibited the destructive abilities of fibrosarcoma cells, but preirradiation of artificial vessel walls substantially decreased their capabilities to resist HT 1080-induced lysis. These findings suggest that the abilities of blood vessels to limit extravasation may be compromised by ionizing radiation

  16. Effects of ancestral x irradiation followed by random mating on body weight of rats

    International Nuclear Information System (INIS)

    Gianola, D.; Chapman, A.B.; Rutledge, J.J.

    1977-01-01

    Effects of nine generations of 450R per generation of ancestral spermatogonial x irradiation of inbred rats on body weight were examined. After six generations of random mating (avoiding inbreeding) following the termination of irradiation, descendants of irradiated males (R) were significantly lighter than their controls (C) at 3 and 6 weeks, but not at 10 weeks of age. However, differences in growth between R and C populations were small. Among-litter and within-litter variance estimates were generally larger in the R lines than in the C lines, suggesting that selection responses would be greater in R than in C lines. In conjunction with previous evidence--obtained during the irradiation phase of the experiment--this suggested that more rapid response to selection for 6-week body weight, in particular, might accrue in the R lines

  17. Cerebral malformation induced by prenatal X-irradiation: an autoradiographic and Golgi study

    Energy Technology Data Exchange (ETDEWEB)

    Ferrer, I.; Xumetra, A.; Santamaria, J. (Neuropatologia, Depto. Anatomia Patologica, C.S. ' Principes de Espana' , Hospitalet de Llobregat, Barcelona (Spain))

    1984-01-01

    Brain malformations are produced after X-irradiation at different post-conceptional ages in the rat. Malformed cortical patterns result from abnormal organisation and capricious orientation of the neurons, while a radical migratory pattern of neuroblasts outwards to the cerebral cortex is preserved in animals irradiated on the fourteenth, sixteenth or eighteenth days of gestation. Migratory disturbances are restricted to the large subcortical ectopic masses found in rats irradiated on the fourteenth gestational day and to pyramidal ectopic nodules in the hippocampus in rats irradiated on the sixteenth gestational day. Subcortical ectopic masses develop from ectopic germinal rosettes and are formed by several types of cortical neuron distributed in a stereotyped pattern. The presence of large numbers of intrinsic, afferent and efferent connections are indicative of integrative functions of the subcortical masses.

  18. Infectivity and development of X-irradiated third-stage larvae of Angiostrongylus cantonensis in rats

    International Nuclear Information System (INIS)

    Fujiu, Yoshinori

    1989-01-01

    Angiostrongylus cantonensis third-stage larvae were exposed to less than 10Krad of X-radiation and then given orally to white rats to examine the effects of X-radiation on infectivity and development of the irradiated third-stage larvae and on fecundity of adults developing from the irradiated third-stage larvae. The deleterious effects of X-radiation were observed at relatively lower dosage in the above three parameters. A degree in susceptibility on X-radiation was shown to be radiation-dose-dependent. Comparing to the irradiation of larvae in vitro, the irradiation of larvae in snails caused less deleterious effects at the same dose of X-irradiation. Application of X-radiation to food hygiene was also discussed. (author)

  19. Protective effect of alkali extract of Huangmo (AEHM) on immunological function in X-irradiated mice

    International Nuclear Information System (INIS)

    Ye Fei; Wu Congmei; Su Shijie; Cao Ruimin

    1996-01-01

    The male mice were given ip AEHM 5 mg/kg, wt/d before irradiation with 2.0 Gy X-rays for 3 days, and the changes of several immunological indexes were observed 24 h after X-irradiation. The results showed that AEHM significantly increased the numbers of splenocytes and thymocytes, the reaction of splenocytes to ConA and the spontaneous proliferation of thymocytes in irradiated mice, and decreased the fall of spleen and thymus. In addition, a tendency of the increases in the above indexes in the intact mice treated with AEHM was observed. Meanwhile, AEHM possessed similar radioprotective effect on immunological functions to polysaccharides of Ginseng. The results suggest that AEHM has not only a radioprotective effect on immunological functions in the irradiated mice, but also an enhancing effect on the defence functions in the intact mice. It is very hopeful that AEHM acted as immune-enhanced drug should be used in the clinic

  20. Cerebral malformation induced by prenatal X-irradiation: an autoradiographic and Golgi study

    International Nuclear Information System (INIS)

    Ferrer, I.; Xumetra, A.; Santamaria, J.

    1984-01-01

    Brain malformations are produced after X-irradiation at different post-conceptional ages in the rat. Malformed cortical patterns result from abnormal organisation and capricious orientation of the neurons, while a radical migratory pattern of neuroblasts outwards to the cerebral cortex is preserved in animals irradiated on the fourteenth, sixteenth or eighteenth days of gestation. Migratory disturbances are restricted to the large subcortical ectopic masses found in rats irradiated on the fourteenth gestational day and to pyramidal ectopic nodules in the hippocampus in rats irradiated on the sixteenth gestational day. Subcortical ectopic masses develop from ectopic germinal rosettes and are formed by several types of cortical neuron distributed in a stereotyped pattern. The presence of large numbers of intrinsic, afferent and efferent connections are indicative of integrative functions of the subcortical masses. (author)

  1. The effect of X-irradiation on aqueous media containing traces of oxygen

    International Nuclear Information System (INIS)

    Evans, N.T.S.

    1981-01-01

    The effect of X-irradiation on small amounts of oxygen dissolved in 1 mM potassium chloride solution, tap water or Eagle's tissue culture medium has been followed with polarographic electrodes. Oxygen is removed from all these solutions down to concentrations corresponding to a few parts per million in the gas phase. Small amounts of hydrogen are also produced by irradiation and can be measured polarographically. Except in Eagle's medium, hydrogen peroxide is formed in the anoxic solutions, and molecular oxygen can be detected after irradiation when catalase is present in the solution. A non-volatile polarographically reducible substance is generated by irradiation of anoxic Eagle's medium. It is not decomposed by catalase but decays spontaneously in solution at a slow rate. (author)

  2. The effect of cyclophosphamide and x-irradiation on experimental influenza in mice

    International Nuclear Information System (INIS)

    Frankova, V.

    1989-01-01

    Mice treated with Cyclophosphamide (Cy) shortly before inoculation of influenza A virus exhibited increased mortality and delayed mean time of death. The extrapulmonary dissemination of the infection was observed more often in Cy-treated animals with the titres of virus in different organs substantially higher than in equally infected immunocompetent controls. Although the humoral antibody response was not impaired in Cy-treated mice, they were more susceptible to challenge with a lethal dose of virus than normal animals. In X-irradiated mice, the increased multiplication of virus in lungs and spread of the infection to other organs was observed, with prolonged persistence of virus in lungs and brains as compared to adequate controls, reminding of previous observation in immunocompromised persons, who died in the course of influenza. (author) 1 fig., 4 tabs., 23 refs

  3. 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

  4. Alternative types of duodenal ulcer induced in mice by partial X irradiation of the thorax

    International Nuclear Information System (INIS)

    Michalowski, A.; Uehara, S.; Yin, W.B.; Burgin, J.; Silvester, J.A.

    1983-01-01

    The present study extends our earlier observations on gastrointestinal pathology in thorax-irradiated female CFLP mice. It shows that exposure of the lower mediastinum to single doses of 14-30 Gy X rays results in the formation of the proximal duodenal ulcer accompanied frequently by erosion of the antral gastric mucosa. X irradiation of the lateral thoracic fields is responsible for single ulcers in the proximity of duodenal papilla, often associated with a circumscribed area of degeneration of the fundic mucosa of the stomach. In view of the small amount of radiation received by the subdiaphragmatic parts of the alimentary tract, these gastro-duodenal lesions represent abscopal effects of thoracic irradiation

  5. The effects of X irradiation on the metamorphosis and budding of Aurelia aurita

    International Nuclear Information System (INIS)

    Prokopchak, M.J.; Spangenberg, D.B.; Shaeffer, J.

    1990-01-01

    With the aid of the Aurelia metamorphosis test system, the acute and subtle developmental and behavioral effects of X irradiation in the presence and absence of thyroxine on the Norfolk Aurelia aurita were described. Radiation doses were 0 (control), 50, 100, 150, 200, and 400 Gy. Morphology of the ephyrae, and statolith and rhopalia numbers were recorded using the light microscope. Developmental abnormalities of the polyps and ephyrae were recorded with the scanning electron microscope and light microscope. Major findings from this investigation were the absence of rhopalia and statoliths in ephyrae at 150 and 200 Gy, a reduction in pulses per minute in the ephyrae at 100, 150, and 200 Gy, a reduction in ephyrae released at 150, 200, and 400 Gy, and the development of polyp monsters. There was a significantly higher frequency of polyp monsters in the group exposed to thyroxine prior to radiation than in the thyroxine-free group prior to radiation

  6. Influence of x irradiation and diet on pituitary/thyroid function in the rat

    International Nuclear Information System (INIS)

    Qassar, I.G.

    1979-01-01

    Rats were maintained on low iodine diet or treated with T 4 . A significant increase in thyroid weight was observed in rats on low iodine diet whereas among rats on normal diet with thyroxine injections, the thyroid was lower in weight than thyroids of control animals. Pituitary weight increased significantly in rats on low iodine diet or T 4 treatment. Labelling index was significantly higher in the group on low iodine diet. A significantly lower labelling index was observed after thyroxine treatment. Where PTU was administered to rats pretreated with either normal diet, normal diet plus T 4 , or maintained on low iodine diet and then exposed to radiation (100 to 400R) to the neck, it was not possible to distinguish the effect of such local radiation on body growth. The pre-radiation treatment did not have any effect on thyroid weight during two weeks post-radiation, suggesting that a four week post-radiation period is essential to elicit radiation effects on the thyroid. Contrary to low iodine treatment, administration of PTU did not result in any increase in pituitary weight in rats maintained on normal diet prior to radiation or in rats maintained on low iodine diet prior to radiation. There was, however, a significant increase in pituitary weight in rats injected with thyroxine prior to radiation (250R or 400R). A significant increase in serum TSH was observed two weeks after radiation and PTU treatment. A lower TSH level was observed, however, in the 250R sub-group (normal diet or T 4 injection) and in the 400R sub-group (low iodine diet). There was a significant difference among sham-irradiated and the three x-irradiated sub-groups maintained on low iodine diet. The results of these studies indicate that local x irradiation with 100 to 400R to the neck may influence thyroid/pituitary function in the rat

  7. Late effects of X-irradiation in patients treated for metropathia haemorrhagica

    Energy Technology Data Exchange (ETDEWEB)

    Smith, P G; Doll, R [Department of Health and Social Security, Cancer Epidemiology and Clinical Trials Unit, 9 Keble Road, Oxford (UK)

    1976-03-01

    The causes of death among 2,068 patients treated with X-irradiation for metropathia haemorrhagica at three Scottish radiotherapy centres between 1940 and 1960 have previously been reported. (Dol, R., and Smith, P.G., 1968, Br. J. Radiol., vol. 41, 362). This cohort of women has now been followed up for a further seven years. 500 (24 per cent) women have now died, 78 (3.8 per cent) have emigrated and 25 (1.2 per cent) could not be traced. The numbers of deaths from different causes have been compared with the numbers expected in a population of similar age and sex exposed to the Scottish national mortality rates over the same period. An excess of deaths from leukaemia (7 observed, 2.3 expected) and of cancers of the heavily irradiated sites (59 observed, 40.1 expected) continues to be observed five or more years after treatment. There is no indication of any change in the excess death rate, due to cancers of sites in the radiation field, with time since treatment up to at least 20 years after the radiation exposure. Over the same period the number of deaths from cancer of the breast was below expectation (10 observed, 22.3 expected) and no increased mortality from coronary disease was seen (102 observed, 100.9 expected). The mean dose of radiaton to the bone marrow has been determined for each woman and it is estimated that the excess rate of leukaemia in the first 20 years after treatment in about 1.1 per million women per year per rad. This figure is in accord with the estimates derived from the survivors of the atomic bomb explosions in Hiroshima and Nagasaki and among patients with ankylosing spondylitis treated with X-irradiation. However, the simple assumption of a linear dose response relationship for leukaemia is probably incorrect, at least when high doses of radiation are delivered to a small volume of marrow.

  8. X-irradiation of mice in the early fetal period. Pt. 2

    International Nuclear Information System (INIS)

    Kriegel, H.; Weber, L.; Schmahl, W.

    1979-01-01

    Pregnant NMRI mice were X-irradiated with 50, 100 and 200 R, respectively, on the twelfth gestational day. The brains of their offspring were weighed and examined for acetylcholinesterase and Na,K-ATPase activities from birth until the 64th postnatal day. The postnatal brain weights were influenced by the prenatal irradiation in a dose-dependent manner. At birth the brains of the treated animals weighed less than those of the controls. After a limited period of restitution (postnatal days 3 to 10), weights fell again, as compared to the controls, and persisted at subnormal levels. This was assumed to be a sequel of surplus neuron cell formation and their speedy degradation as soon as neuronal function had been established. The curves of the activites (per gram of brain tissue) of acetylcholinesterase as well as Na,K-ATPase showed oscillating compensatory responses to the prenatal irradiation. Activities were preferentially found at supernormal levels, the oscillation lasting as long as the restitution period of the brain weights. With the 50 R and 100 R groups, enzyme activities were steadily above the control levels from the 16th until the 48th day after birth. On the 64th postnatal day all enzyme activities but one (200 R, Na,K-ATPase) had returned to the control levels. Oscillating responses to prenatal X-irradiation have been described for the DNA-synthesis in livers and brains of mice during the first three postnatal weeks. From this perspective, our results are discussed as the outcome of radiation-induced alterations in genome activity. (orig.) [de

  9. Protein Oxidation in the Lungs of C57BL/6J Mice Following X-Irradiation

    Science.gov (United States)

    Barshishat-Kupper, Michal; McCart, Elizabeth A.; Freedy, James G.; Tipton, Ashlee J.; Nagy, Vitaly; Kim, Sung-Yop; Landauer, Michael R.; Mueller, Gregory P.; Day, Regina M.

    2015-01-01

    Damage to normal lung tissue is a limiting factor when ionizing radiation is used in clinical applications. In addition, radiation pneumonitis and fibrosis are a major cause of mortality following accidental radiation exposure in humans. Although clinical symptoms may not develop for months after radiation exposure, immediate events induced by radiation are believed to generate molecular and cellular cascades that proceed during a clinical latent period. Oxidative damage to DNA is considered a primary cause of radiation injury to cells. DNA can be repaired by highly efficient mechanisms while repair of oxidized proteins is limited. Oxidized proteins are often destined for degradation. We examined protein oxidation following 17 Gy (0.6 Gy/min) thoracic X-irradiation in C57BL/6J mice. Seventeen Gy thoracic irradiation resulted in 100% mortality of mice within 127–189 days postirradiation. Necropsy findings indicated that pneumonitis and pulmonary fibrosis were the leading cause of mortality. We investigated the oxidation of lung proteins at 24 h postirradiation following 17 Gy thoracic irradiation using 2-D gel electrophoresis and OxyBlot for the detection of protein carbonylation. Seven carbonylated proteins were identified using mass spectrometry: serum albumin, selenium binding protein-1, alpha antitrypsin, cytoplasmic actin-1, carbonic anhydrase-2, peroxiredoxin-6, and apolipoprotein A1. The carbonylation status of carbonic anhydrase-2, selenium binding protein, and peroxiredoxin-6 was higher in control lung tissue. Apolipoprotein A1 and serum albumin carbonylation were increased following X-irradiation, as confirmed by OxyBlot immunoprecipitation and Western blotting. Our findings indicate that the profile of specific protein oxidation in the lung is altered following radiation exposure. PMID:28248270

  10. Normal cellular radiosensitivity in an adult Fanconi anaemia patient with marked clinical radiosensitivity

    International Nuclear Information System (INIS)

    Marcou, Yiola; D'Andrea, Andrew; Jeggo, Penelope A.; Plowman, Piers N.

    2001-01-01

    Background: Fanconi anaemia is a rare disease associated with cellular sensitivity to chemicals (e.g. mitomycin C and diepoxybutane); variable but mild cellular radiosensitivity has also been reported. Materials and methods: A 32-year-old patient with Fanconi anaemia and tonsillar carcinoma, treated by radiotherapy, was found to exhibit profound clinical radiosensitivity. Confluent, ulcerating oropharyngeal mucositis developed after a conventionally fractionated dose of 34 Gy and healing was incomplete by 2 months after cessation of therapy. Results: Cellular radiosensitivity assays and RPLD studies from this patient did not suggest any major detectable radiosensitivity. Conclusion: There is a discrepancy between the observed clinical radiosensitivity and the usual 'predictive' radiosensitivity assays in this patient with Fanconi anaemia

  11. Radiogenomics: predicting clinical normal tissue radiosensitivity

    DEFF Research Database (Denmark)

    Alsner, Jan

    2006-01-01

    Studies on the genetic basis of normal tissue radiosensitivity, or  'radiogenomics', aims at predicting clinical radiosensitivity and optimize treatment from individual genetic profiles. Several studies have now reported links between variations in certain genes related to the biological response...... to radiation injury and risk of normal tissue morbidity in cancer patients treated with radiotherapy. However, after these initial association studies including few genes, we are still far from being able to predict clinical radiosensitivity on an individual level. Recent data from our own studies on risk...

  12. Nervous system disease associated with dominant cellular radiosensitivity

    International Nuclear Information System (INIS)

    Kidson, C.; Chen, P.; Imray, F.P.; Gipps, E.

    1983-01-01

    Ionizing radiation sensitivity has been demonstrated in the following neurological diseases: sporadic and familial Alzheimer's disease, familial non-specific dementia, amyotrophic lateral sclerosis and Parkinsonism dementia of Guam, Huntington's disease, multiple sclerosis. Family studies in many cases give data consistent with dominant genetics, as does cell fusion analysis in the one disease so studied. In no case was there an absolute association between radiosensitivity and a given neurological disease. It is proposed that the underlying mutations are in genes controlling facets of nervous or immune system differentiation and development. 15 references, 2 tables

  13. Effect of cisplatin on the clinically relevant radiosensitivity of human cervical carcinoma cell lines

    International Nuclear Information System (INIS)

    Britten, Richard A.; Evans, Andrew J.; Allalunis-Turner, M. Joan; Pearcey, Robert G.

    1996-01-01

    Purpose: To evaluate the effect of clinically relevant levels of cisplatin on the radiosensitivity of human cervical tumor cells, and to estimate what changes in local control rates might be expected to accrue from the concomitant use of cisplatin during fractionated radiotherapy. Methods and Materials: The effects of concomitant cisplatin (1 μg/ml, a typical intratumor concentration) on the clinically relevant radiosensitivity, i.e., surviving fraction after 2 G (SF 2 ) values, was determined in 19 cloned human cervical tumor cell lines. These early passage cell lines had SF 2 values ranging from 0.26 to 0.87. Results: The concomitant administration of cisplatin reduced the clinically relevant radiosensitivity in the majority (11 out of 19) of the human tumor cell lines investigated. In only 4 out of 19 was any radiosensitization observed, and in 4 out of 19 cell lines there was no significant change in radiosensitivity. However, the sum of the independent cell killing by radiation and cisplatin, was approximately twofold higher than after radiation alone. There was no apparent dependence of the cisplatin-induced changes in SF 2 values upon the level of cell killing by cisplatin. However, there is a suggestion that concomitant cisplatin administration may have a differential effect in inherently radiosensitive and resistant human tumor cell lines. Conclusions: Our data suggest that concomitant cisplatin/radiotherapy regimens may result in a higher level of local tumor control, but primarily through additive toxicity and not through radiosensitization. Future improvements in local tumor control may, thus, be derived by increasing the total dose of cisplatin

  14. Radiosensitivity of mesothelioma cell lines

    Energy Technology Data Exchange (ETDEWEB)

    Haekkinen, A.M. [Dept. of Oncology, Univ. Central Hospital, Helsinki (Finland); Laasonen, A. [Dept. of Pathology, Central Hospital of Etelae-Pohjanmaa, Seinaejoki (Finland); Linnainmaa, K. [Dept. of Industrial Hygiene and Toxicology, Inst. of Occupational Health, Helsinki (Finland); Mattson, K. [Dept. Pulmonary Medicine, Univ. Central Hospital, Helsinki (Finland); Pyrhoenen, S. [Dept. of Oncology, Univ. Central Hospital, Helsinki (Finland)

    1996-10-01

    The present study was carried out in order to examine the radiosensitivity of malignant pleural mesothelioma cell lines. Cell kinetics, radiation-induced delay of the cell cycle and DNA ploidy of the cell lines were also determined. For comparison an HeLa and a human foetal fibroblast cell line were simultaneously explored. Six previously cytogenetically and histologically characterized mesothelioma tumor cell lines were applied. A rapid tiazolyl blue microtiter (MTT) assay was used to analyze radiosensitivity and cell kinetics and DNA ploidy of the cultured cells were determined by flow cytometry. The survival fraction after a dose of 2 Gy (SF2), parameters {alpha} and {beta} of the linear quadratic model (LQ-model) and mean inactivation dose (D{sub MID}) were also estimated. The DNA index of four cell lines equaled 1.0 and two cell lines equaled 1.5 and 1.6. Different mesothelioma cell lines showed a great variation in radiosensitivity. Mean survival fraction after a radiation dose of 2 Gy (SF2) was 0.60 and ranged from 0.36 to 0.81 and mean {alpha} value was 0.26 (range 0.48-0.083). The SF2 of the most sensitive diploid mesothelioma cell line was 0.36: Less than that of the foetal fibroblast cell line (0.49). The survival fractions (0.81 and 0.74) of the two most resistant cell lines, which also were aneuploid, were equal to that of the HeLa cell line (0.78). The {alpha}/{beta} ratios of the most sensitive cell lines were almost an order of magnitude greater than those of the two most resistant cell lines. Radiation-induced delay of the most resistant aneuploid cell line was similar to that of HeLa cells but in the most sensitive (diploid cells) there was practically no entry into the G1 phase following the 2 Gy radiation dose during 36 h. (orig.).

  15. Effects of X irradiation on the cytoskeleton of rat alveolar macrophages in vitro

    International Nuclear Information System (INIS)

    Ladyman, S.J.; Townsend, K.M.S.; Edwards, C.

    1984-01-01

    The three-dimensional visualization of Triton X-100 resistant cytoskeletons has been used to demonstrate that an absorbed dose of 120 Gy from X rays causes a distinctive and reproducible alteration of the cytoskeleton of intact rat alveolar macrophages in vitro. The alteration has also been shown to be rapidly and completely ''repaired'' and to be apparently similar to alterations caused by colchicine but dissimilar to those caused by cytochalasin B. From these observations and those of other workers who have studied the irradiation of extracted microtubular proteins in vitro, the authors think it likely that microtubules rather than microfilaments are the radiosensitive component of the macrophage cytoskeleton

  16. Activity and isoenzyme composition of lipoxygenase of X-irradiated pea seeds

    International Nuclear Information System (INIS)

    Chepurenko, N.V.; Borisova, I.G.; Budnitskaya, E.V.

    1977-01-01

    Action of X-radiation, in vitro, on the isoenzyme composition and activity of lipoxygenase (E. C. 1.13.11.12), that catalyzes the process of peroxidation of unsaturated higher fatty acids, has been studied. Radiosensitivity of lipoxygenase isoenzymes has been found to vary. After doses above 10 krad, the postirradiation inactivation of lipoxygenase was due to a changed ratio of isoenzymes and their depolymerization; and it was accompanied by the appearance of a new protein fragment that had no specific lipoxygenase activity

  17. Influence of spermatogenesis functional state on female sterility under single local x-irradiation

    International Nuclear Information System (INIS)

    Strel'nikova, N.K.; Kudritskaya, O.Yu.

    1978-01-01

    An experiment which simulated conditions of radiation exposure in X ray studies of human beings was staged to see what was the contribution of the sex-related radiosensitivity to the biologic effect from local exposure of the pelvis region. Second-generation white mice were irradiated with doses of 7.34 to 360 R. It was found that with the dose increase, the number of sterile females also increased with a concomitant reduction in the number of live spermatozoa in the seman of males, which can be considered as evidence that these two processes are interrelated

  18. The inherited basis of human radiosensitivity

    Energy Technology Data Exchange (ETDEWEB)

    Gatti, R.A. [Univ. of California, School of Medicine, Los Angeles, CA (United States). Experimental Pathology

    2001-11-01

    Certain individuals cannot tolerate 'conventional' doses of radiation therapy. This is known to be true of patients with ataxia-telangiectasia and ligase IV deficiency. Although in vitro testing may not correlate completely with clinical radiosensitivity, fibroblasts and lymphoblasts from patients with both of these disorders have been clearly shown to be radiosensitive. Using a colony survival assay (CSA) to test lymphoblastoid cells after irradiation with 1 Gy, a variety of other genetic disorders have been identified as strong candidates for clinical radiosensitivity, such as Nijmegen breakage syndrome, Mre11 deficiency, and Fanconi's anemia. These data are presented and considered as a starting-point for the inherited basis of human radiosensitivity.

  19. Comparative radiosensitivity in the class insecta

    International Nuclear Information System (INIS)

    Willard, W.K.; Cherry, D.S.

    1975-01-01

    A 'radiosensitivity index' (LT 50 /mean longevity) was correlated with the mean longevity and dry weight of 37 insect species (both sexes of 12 species) representing eight orders. Curvilinear regression analysis relating radiosensitivity to mean longevity and mean dry weight indicated that 46.3% of the observed variation could be attributed to longevity and 32.6% to the dry weight of the species. In general, large long-lived adults were more radiosensitive than small short-lived adults. Correlation of the phylogeny of insect orders and order groupings with the radio-sensitivity index was found to be poor. However, when the index was related to longevity, there was a tendency for species comprising the major orders investigated to occur in groups along the predicted curve. (author)

  20. DNA-membrane complex restoration in Micrococcus radiodurans after X-irradiation: relation to repair, DNA synthesis and DNA degradation

    Energy Technology Data Exchange (ETDEWEB)

    Dardalhon-Samsonoff, M; Averbeck, D [Institut du Radium, 75 - Paris (France). Lab. Curie

    1980-07-01

    The DNA-membrane complex in Micrococcus radiodurans was shown to be essentially constituted of proteins, lipids and DNA. The complex was dissociated immediately after X-irradiation of cells and restored during post-incubation in complete medium. In X-irradiated protoplasts some DNA remained associated with the complex. Restoration of the complex during post-incubation was only seen in a medium favouring DNA polymerase and ligase activities. Under this condition no DNA synthesis occurred, suggesting that complex restoration may involve ligase activity. The complex restoration in the wild type and the X-ray sensitive mutant UV17 of M. radiodurans was strictly dependent on the X-ray dose. It was correlated with survival and DNA degradation but always preceded the onset of DNA synthesis after X-irradiation. At the same dose the complex restoration was about 2 fold lower in mutant than in wild type cells indicating that the restoration of the complex is related to repair capacity. The results are consistent with the idea that the complex protects X-irradiated DNA of M. radiodurans from further breakdown and, subsequently, permits DNA synthesis and repair to occur.

  1. Enhancement of the effect of X-irradiation against cultured human glioblastoma cells by pretreatment with ACNU

    Energy Technology Data Exchange (ETDEWEB)

    Mashiyama, Shoji; Katakura, Ryuichi; Takahashi, Kou; Kitahara, Masakazu; Suzuki, Jiro [Tohoku Univ., Sendai (Japan). Inst. of Brain Diseases; Sasaki, Takehito

    1989-12-01

    Human glioblastoma A-7 (GB A-7) cells can apparently recover from potentially lethal X-irradiation. The authors, using a colony-forming assay, studied the influence of pretreatment with 1-(4-amino-2-methyl-5-pyrimidinyl)methyl-3- (2-chloroethyl)-3-nitrosourea hydrochloride (ACNU) on the effectiveness of X-irradiation against GB A-7 cells grown in monolayers and as multicellular spheroids. Pre-exposure to ACNU inhibited the recovery of irradiated GB A-7 cells. In monolayer cells, the combination treatment was most effective when ACNU was applied 2 to 8 hours prior to irradiation, and the larger the X-ray dose, the more potent the effect. ACNU pretreatment was more effective against large spheroids (enhancement ratio 1.86) than against small ones (1.34). Large spheroids showed necrosis, whereas small ones did not. Isobolographic analysis disclosed that the effect of combining X-irradiation and ACNU is within an additive envelope at the surviving fraction of 10{sup -2}, while supra-additive at the surviving fraction of 10{sup -3}. These results suggest that the potency of X-irradiation is augmented by ACNU pretreatment through an interactive mechanism. Further, suppression of recovery from X-ray induced potentially lethal damage was influenced by the presence of necrosis. (author).

  2. Sedimentation of nucleoids from thymus and spleen cells of rats after X-irradiation in vitro and in vivo

    International Nuclear Information System (INIS)

    Heinzelmann, R.

    1987-01-01

    The reaction to irradiation of thymocytes was tested immediately and 6 hours after whole body X-irradiation of rats with doses from 190 cGy up to 1520 cGy by nucleoid sedimentation. For comparison, examinations of thymus and spleen cells after X-irradiation in vitro were done. Preliminary analyses should find a possible coergism between X-rays on one side and hyperthermia and inhibitors of DNA-synthesis or DNA-repair (cytosinearabinoside, dideoxythymidine, 3-amino-benzamide, ethidiumbromide, and novobiocine) on the other side. From the results the following conclusions may be drawn: 1) With respect to the detection of in vivo effects of X-irradiation, the nucleoid sedimentation is less sensitive than biochemical methods. 2) Some hours after sublethal X-irradiation in vivo, free DNA and/or polydesoxyribonucleotides appear. At the same time cross-links can be detected in the chromatin fraction. 3) The reduction of the nucleoid sedimentation immediately after high doses of whole-body irradiation is the result of primary DNA lesions. The changes detectable some hours after are due to the secondary enzymatic changes, that are connected with the interphase death of thymocytes, and coincide with the present opinions about the irradiation induced apoptosis of cells. (orig./ECB) [de

  3. Enhancement of the effect of X-irradiation against cultured human glioblastoma cells by pretreatment with ACNU

    International Nuclear Information System (INIS)

    Mashiyama, Shoji; Katakura, Ryuichi; Takahashi, Kou; Kitahara, Masakazu; Suzuki, Jiro; Sasaki, Takehito.

    1989-01-01

    Human glioblastoma A-7 (GB A-7) cells can apparently recover from potentially lethal X-irradiation. The authors, using a colony-forming assay, studied the influence of pretreatment with 1-(4-amino-2-methyl-5-pyrimidinyl)methyl-3- (2-chloroethyl)-3-nitrosourea hydrochloride (ACNU) on the effectiveness of X-irradiation against GB A-7 cells grown in monolayers and as multicellular spheroids. Pre-exposure to ACNU inhibited the recovery of irradiated GB A-7 cells. In monolayer cells, the combination treatment was most effective when ACNU was applied 2 to 8 hours prior to irradiation, and the larger the X-ray dose, the more potent the effect. ACNU pretreatment was more effective against large spheroids (enhancement ratio 1.86) than against small ones (1.34). Large spheroids showed necrosis, whereas small ones did not. Isobolographic analysis disclosed that the effect of combining X-irradiation and ACNU is within an additive envelope at the surviving fraction of 10 -2 , while supra-additive at the surviving fraction of 10 -3 . These results suggest that the potency of X-irradiation is augmented by ACNU pretreatment through an interactive mechanism. Further, suppression of recovery from X-ray induced potentially lethal damage was influenced by the presence of necrosis. (author)

  4. Radiosensitivity and cell kinetics of the human solid cancer transplanted to nude mouse

    International Nuclear Information System (INIS)

    Ikeuchi, Shunji

    1983-01-01

    This study was undertaken to analyse the relationship between radiosensitivity and cell kinetics of human solid cancer in experimental nude mouse system. Four strains of tumors used for the experiment were poorly differentiated squamous cell carcinoma of the lung (Lu-9), oat cell carcinoma of the lung (Lu-24), well differentiated squamous cell carcinoma of the tongue (To-1) and moderately differentiated squamous cell carcinoma of the esophagus (Es-4) which were serially transplantable to BALB/c nude mice. Radiosensitivity was evaluated by tumor growth in terms of inhibition rate, histological change and host reaction after irradiation. Cell kinetics were studied by autoradiography with pulse administration of 3 H-thymidine to mice. Although Lu-24 was most radiosensitive, followed by To-1, Es-4 and Lu-9 in the order of sensitivity, it was suggested that they might be more radioresistant in nude mice without T-cell function than in human. Regarding squamous cell carcinomas, well differentiated type was more radiosensitive than poorly differentiated one. All of these tumors in nude mouse revealed distinct percent labeled mitosis curves with two clear peaks which were quite different from those in human body. Lu-24 showed a characteristic pattern with a long time lag before visible growth, short G 1 , and low growth fraction, compared to other three tumors. Three strains of squamous cell carcinoma demonstrated similar cell kinetic factors which were almost the same as those in human body reported previously. The differences in volume doubling time of tumor, growth fraction and cell loss factor were partially related to those of radiosensitivities among tumors except for Lu-24. The theoretical volume doubling time was proved to be most reliable for estimation of effectiveness of irradiation, but the labeling index was not a valuable indicator for it. (author)

  5. Regional difference of radiosensitivity of neural cells in the fetal brain of mice on day 13 of gestation

    International Nuclear Information System (INIS)

    Hoshino, Kiyoshi; Kameyama, Yoshiro

    1986-01-01

    Pregnant Slc: ICR mice were exposed to a single whole-body X-irradiation at a dose of 12.5 R or 25 R on day 13 of gestation. After irradiation, fetuses were obtained from mothers at 1- or 3-hour intervals and coronal histological sections were made. Pyknotic cells were counted in the ventricular zone of brain mantle, hippocampal anlage and olfactory bulb. In the 25 R group, peak incidences of pyknotic cells in brain mantle, hippocampal anlage and olfactory bulb were 13.2 %, 6.9 % and 2.2 %, respectively. In the 12.5 R group, these were 6.0 %, 3.2 % and 1.7 %, respectively. This result indicates that neural cells in the ventricular zone of brain mantle are the most radiosensitive among the cerebral regions examined in day-13 mouse fetuses. (author)

  6. The protective effects of vitamin E on microcephaly in rats X-irradiated in utero: DNA, lipid peroxide and confronting cisternae

    International Nuclear Information System (INIS)

    Tanaka, Harumi; Iwasaki, Setsuo; Inomata, Kenichirou; Nasu, Fumio; Nishimura, Shigeru

    1986-01-01

    Fetuses from rats given either water or 0.03% D,L-α-tocopherol acetate (vitamin E) as a drinking fluid and X-irradiated with 100 rad on gestational day 13 were examined on gestational day 21. Mean cerebral weight which was significantly reduced by the X-irradiation was increased by vitamin E supplementation but the level did not reach that in sham-irradiated controls. Administration of vitamin E caused an increase in DNA concentration which was significantly reduced by X-irradiation with water treatment. An increase in the mean level of lipid peroxide formation was observed in the water-treated, X-irradiated group in the sample at zero time but not in the vitamin E-treated, X-irradiated group. In the cytoplasm of fetal cerebral neurons from X-irradiated dams with vitamin E supplementation, confronting cisternae were frequently observed between two nuclear envelopes. Confronting cisternae may be considered as a repair mechanism of vitamin E against X-irradiated neuronal damage in the fetal cerebrum. This study provides evidence of the protection by vitamin E of neuronal development in X-irradiated fetuses, through its antioxidant properties, against attacks by free radicals and/or lipid peroxide. (orig.)

  7. Quantification of 5-hydroxytryptamine1A receptors in the cerebellum of normal and x-irradiated rats during postnatal development

    International Nuclear Information System (INIS)

    Matthiessen, L.; Daval, G.; Bailly, Y.; Gozlan, H.; Hamon, M.; Verge, D.

    1992-01-01

    5-Hydroxytryptamine 1A receptors were studied in rats during the first postnatal month in the normal cerebellum and in the granule cell-deprived cerebellum produced by X-irradiation at postnatal day 5. Quantitative autoradiographic studies on sagittal sections of cerebellar vermis, using [ 125 1]BH-8-MeO-N-PAT as radioligand or specific anti-receptor antibodies, revealed that 5-hydroxytryptamine 1A receptors existed in the molecular/Purkinje cell layer but at variable density from one lobule to another. Thus, in both normal and X-irradiated rats, the posterior lobules were more heavily labelled than the anterior ones, and the density of 5-hydroxytryptamine 1A sites decreased progressively in all the cerebellar folia down to hardly detectable levels at postnatal day 21. However, the intensity of labelling remained higher at postnatal day 8 and postnatal day 12 in X-irradiated rats than in age-paired controls. Measurements of [ 3 H]8-OH-DPAT [8-hydroxy-2-(di-n-propylamino)tetralin] specific binding to membranes from whole cerebellum confirmed that the density of 5-hydroxytryptamine 1A sites per mg membrane protein (B max ) was higher in X-irradiated animals than in age-paired controls. However, on a ''per cerebellum'' basis, no significant difference could be detected between the total number of 5-hydroxytryptamine 1A sites, which progressively increased in both control and X-irradiated animals during the first postnatal month. These results therefore show that 5-hydroxytryptamine 1A receptors are not located on developing granule cells. (author)

  8. The prospective application of a hypoxic radiosensitizer, doranidazole to rat intracranial glioblastoma with blood brain barrier disruption

    International Nuclear Information System (INIS)

    Yasui, Hironobu; Asanuma, Taketoshi; Kino, Junichi; Yamamori, Tohru; Meike, Shunsuke; Nagane, Masaki; Kubota, Nobuo; Kuwabara, Mikinori; Inanami, Osamu

    2013-01-01

    Glioblastoma is one of the intractable cancers and is highly resistant to ionizing radiation. This radioresistance is partly due to the presence of a hypoxic region which is widely found in advanced malignant gliomas. In the present study, we evaluated the effectiveness of the hypoxic cell sensitizer doranidazole (PR-350) using the C6 rat glioblastoma model, focusing on the status of blood brain barrier (BBB). Reproductive cell death in the rat C6 glioma cell line was determined by means of clonogenic assay. An intracranial C6 glioma model was established for the in vivo experiments. To investigate the status of the BBB in C6 glioma bearing brain, we performed the Evans blue extravasation test. Autoradiography with [ 14 C]-doranidazole was performed to examine the distribution of doranidazole in the glioma tumor. T2-weighted MRI was employed to examine the effects of X-irradiation and/or doranidazole on tumor growth. Doranidazole significantly enhanced radiation-induced reproductive cell death in vitro under hypoxia, but not under normoxia. The BBB in C6-bearing brain was completely disrupted and [ 14 C]-doranidazole specifically penetrated the tumor regions. Combined treatment with X-irradiation and doranidazole significantly inhibited the growth of C6 gliomas. Our results revealed that BBB disruption in glioma enables BBB-impermeable radiosensitizers to penetrate and distribute in the target region. This study is the first to propose that in malignant glioma the administration of hydrophilic hypoxic radiosensitizers could be a potent strategy for improving the clinical outcome of radiotherapy without side effects

  9. Effects of early postnatal X-irradiation of the hippocampus on discrimination learning in adult rats

    International Nuclear Information System (INIS)

    Gazzara, R.A.

    1980-01-01

    Rats with x-irradiation-produced degranulation of the hippocampal dentate gyrus were trained in the acquisition and reversal of simultaneous visual and tactile discriminations in a T-maze. These experiments employed the same treatment, apparatus, and procedure, but varied in task difficulty. In the brightness and roughness discriminations, the irradiated rats were not handicapped in acquiring or reversing discriminations of low or low-moderate task-difficulty. However, these rats were handicapped in acquiring and reversing discriminations of moderate and high task-difficulty. In a Black/White discrimination, in which the stimuli were restricted to the goal-arm walls, the irradiated rats were handicapped in the acquisition (low task-difficulty) and reversal (moderate task-difficulty) phases of the task. These results suggest that the irradiated rats were not handicapped when the noticeability of the stimuli was high, irrespective of modality used, but were handicapped when the noticeability of the stimuli was low. In addition, these results are consistent with the hypothesis that hippocampal-damaged rats are inattentive due to hyperactivity

  10. Effects of neonatal thymic exposure to high doses of X-irradiation

    International Nuclear Information System (INIS)

    Bains, G.S.; Sundaram, K.

    1979-01-01

    The thymic region of neonatal Swiss mice was exposed to doses varying from 1000 R to 2000 R of X-irradiation. The animals did not show any signs of wasting syndrome up to 6 months after irradiation. At this time hyperplasia of the thymus with an associated lymphocytosis was evident in irradiated animals. Antibody production to sheep red blood cells (SRBC) was not affected. However, at 12 months post-irradiation the animals showed signs of wasting disease with a progressive increase in their numbers at 18 and 24 months of age. The percentage incidence of animals with wasting disease was dose dependent. At this stage in the majority of the animals with the disease the thymus showed varying degrees of atrophy along with splenomegaly. There were no significant differences in the number of lymphocytes but the number of granulocytes showed a substantial increase. This was more evident in animals exposed to 2000 R to the thymic region. Though one observed a lowered ability to form antibodies to bovine serum albumin (BSA) with advancing age, the thymic irradiation did not affect the immune response to BSA even in animals manifesting wasting disease. An interesting observation has been the development of a severe loss of muscle power and tone in the hind limbs in a large majority of animals. (author)

  11. Early postnatal x-irradiation of the hippocampus and discrimination learning in adult rats

    International Nuclear Information System (INIS)

    Gazzara, R.A.; Altman, J.

    1981-01-01

    Rats with X-irradiation-produced degranulation of the hippocampal dentate gyrus were trained in the acquisition and reversal of simultaneous visual and tactile discriminations in a T-maze. These experiments employed the same treatment, apparatus, and procedure but varied in task difficulty. In the brightness and roughness discriminations, the irradiated rats were not handicapped in acquiring or reversing discriminations of low or low-moderate task difficulty. However, these rats were handicapped in acquiring and reversing discriminations of moderate and high task difficulty. In a Black/White discrimination, in which the stimuli were restricted to the goal-arm walls, the irradiated rats were handicapped in the acquisition (low task difficulty) and reversal (moderate task difficulty) phases of the task. These results suggest that the irradiated rats were not handicapped when the noticeability of the stimuli was high, irrespective of modality used, but were handicapped when the noticeability of the stimuli was low. In addition, these results are consistent with the hypothesis that rats with hippocampal damage are inattentive due to hyperactivity

  12. ENDOR-Induced EPR of Disordered Systems: Application to X-Irradiated Alanine.

    Science.gov (United States)

    Kusakovskij, Jevgenij; Maes, Kwinten; Callens, Freddy; Vrielinck, Henk

    2018-02-15

    The electron paramagnetic resonance (EPR) spectra of radiation-induced radicals in organic solids are generally composed of multiple components that largely overlap due to their similar weak g anisotropy and a large number of hyperfine (HF) interactions. Such properties make these systems difficult to study using standard cw EPR spectroscopy even in single crystals. Electron-nuclear double-resonance (ENDOR) spectroscopy is a powerful and widely used complementary technique. In particular, ENDOR-induced EPR (EIE) experiments are useful for separating the overlapping contributions. In the present work, these techniques were employed to study the EPR spectrum of stable radicals in X-irradiated alanine, which is widely used in dosimetric applications. The principal values of all major proton HF interactions of the dominant radicals were determined by analyzing the magnetic field dependence of the ENDOR spectrum at 50 K, where the rotation of methyl groups is frozen. Accurate simulations of the EPR spectrum were performed after the major components were separated using an EIE analysis. As a result, new evidence in favor of the model of the second dominant radical was obtained.

  13. DNA strand breaks, repair, and survival in x-irradiated mammalian cells

    International Nuclear Information System (INIS)

    Dugle, D.L.; Gillespie, C.J.; Chapman, J.D.

    1976-01-01

    The yields of unrepairable single- and double-strand breaks in the DNA of x-irradiated Chinese hamster cells were measured by low-speed neutral and alkaline sucrose density gradient sedimentation in order to investigate the relation between these lesions and reproductive death. After maximal single-strand rejoining, at all doses, the number of residual single-strand breaks was twice the number of residual double-strand breaks. Both double-strand and unrepairable single-strand breaks were proportional to the square of absorbed dose, in the range 10-50 krad. No rejoining of double-strand breaks was observed. These observations suggest that, in mammalian cells, most double-strand breaks are not repairable, while all single-strand breaks are repaired except those that are sufficiently close on complementary strands to constitute double-strand breaks. Comparison with cell survival measurements at much lower doses suggests that loss of reproductive capacity corresponds to induction of approximately one double-strand break

  14. The analysis of the defense mechanism against indigenous bacterial translocation in X-irradiated mice

    International Nuclear Information System (INIS)

    Kobayashi, Toshiya; Ohmori, Toshihiro; Yanai, Minoru; Kawanishi, Gosei; Mitsuyama, Masao; Nomoto, Kikuo.

    1991-01-01

    The defense mechanism against indigenous bacterial translocation was studied using a model of endogenous infection in X-irradiated mice. All mice irradiated with 9 Gy died from day 8 to day 15 after irradiation. The death of mice was observed in parallel with the appearance of bacteria from day 7 in various organs, and the causative agent was identified to be Escherichia coli, an indigenous bacterium translocating from the intestine. Decrease in the number of blood leukocytes, peritoneal cells and lymphocytes in Peyer's patches or mesenteric lymph nodes was observed as early as 1 day after irradiation with 6 or 9 Gy. The mitogenic response of lymphocytes from various lymphoid tissues was severely affected as well. The impairment of these parameters for host defense reached the peak 3 days after irradiation and there was no recovery. However, in vivo bacterial activity of Kupffer cells in mice irradiated with 9 Gy was maintained in a normal level for a longer period. It was suggested that Kupffer cells play an important role in the defense against indigenous bacteria translocating from the intenstine in mice. (author)

  15. Changes with age in swimming performance of X-irradiated mice

    International Nuclear Information System (INIS)

    Norimura, T.; Yoshikawa, I.; Okajima, S.

    1980-01-01

    The time required to swim 250 cm was determined once weekly for the entire life of fifteen pairs of male dd/K mice. The irradiated group was exposed to a single 224 rad of X-rays at 20 weeks of age. Median survival time (ST 50 ) for the control was 88.9 weeks and that for the irradiated group was 77.4 weeks, and both regression lines relating to death rate and age were parallel. The swimming ability of control mice began to decrease when the mice were 40 weeks of age, after which there was a gradual reduction with age at 0.00646/day. In the irradiated group, the swimming ability decreased from seven weeks after irradiation. The time of 50% reduction of swimming speed (TRS 50 ) for the control was 78.9 weeks and that for the irradiated group was 66.3 weeks, and the slopes of the regression lines relating reduction rate and age were similar. Differences between ST 50 and TRS 50 were 10 weeks in the control and 11 weeks in the irradiated group, respectively. These results indicate that there is no basic difference in the reduction in swimming ability between control and irradiated mice. The X-irradiation may simply mean that the reduction in the swimming ability is displaced to an earlier time with no alteration in the rate of reduction, and that the earlier appearance in the irradiated group is related to premature aging as induced by irradiation. (author)

  16. Go/no-go discriminated avoidance learning in prenatally x-irradiated rats

    International Nuclear Information System (INIS)

    Tamaki, Y.; Inouye, M.

    1988-01-01

    Male Fischer344 rats were exposed to x-irradiation at a dose of 200 rad on Day 17 of gestation. Irradiated and control rats were tested at 10-13 weeks of age with the paradigm of go/no-go (active-passive) discriminated avoidance conditioning for three consecutive daily sessions. During the first conditioning session, they learned only active avoidance responses to two different warning signals. During the second and third sessions, they learned active and passive avoidance responses: in response to one warning signal, rats were required to make an active response to avoid a shock, but not to run in response to the other signal in order to avoid a shock. Prenatally irradiated rats made more active avoidance responses to both warning signals than controls (first session). In the early training phase of the go/no-go task, irradiated rats performed significantly higher active and lower passive avoidance responses than controls. Irradiated rats established a strong tendency to respond actively to the no-go signal, but eventually learned to respond to it

  17. Estimates of genetic parameters of body weight in descendants of x-irradiated rat spermatogonia

    International Nuclear Information System (INIS)

    Gianola, D.; Chapman, A.B.; Rutledge, J.J.

    1977-01-01

    Effects of nine generations of 450 R per generation of ancestral spermatogonial x irradiation of inbred rats on genetic parameters of body weight at 3, 6 and 10 weeks of age and of weight gains between these periods were studied. Covariances among relatives were estimated by mixed model and regression techniques in randomly selected lines with (R) and without (C) radiation history. Analyses of the data were based on five linear genetic models combining additive direct, additive indirect (maternal), dominance and environmental effects. Parameters in these models were estimated by generalized least-squares. A model including direct and indirect genetic effects fit more closely to the data in both R and C lines. Overdominance of induced mutations did not seem to be present. Ancestral irradiation increased maternal additive genetic variances of body weights and gains but not direct genetic variances. Theoretically, due to a negative direct-maternal genetic correlation, within full-sib family selection would be ineffective in increasing body weight at six weeks in both R and C lines. However, progress from mass selection would be expected to be faster in the R lines

  18. Changes in activities of adaptive liver enzymes in rats after non-lethal x-irradiation

    International Nuclear Information System (INIS)

    Toropila, M.; Ahlersova, E.; Ahlers, I.; Benova, K.

    1998-01-01

    The effect of a single dose of whole-body X-irradiation of 2.39 Gy (250 R) on the activities of selected adaptive rat liver enzymes and blood serum corticosterone concentrations was followed for a period of 28 days. Rats of Wistar strain SPF breeding (VELAZ Prague) were used. Both irradiated and control animals were fed in pairs with the same amount of feed as was consumed by irradiated animals in the pilot experiment. The feed intake of irradiated animals decreased significantly until the fourth day. During the rest of the experimental period no significant differences were recorded in feed intake between the experimental and control groups. The activity of tyrosine aminotransferase (TAT) in the liver of irradiated animals increased, with the exception of the initial period. Similar changes were recorded in the activity of tryptophane-2-3 dioxygenase (TO). A significant increase on the third day and a significant decrease from the seventh day after irradiation was recorded in the activity of aspartate aminotransferase (AST). Similar changes were observed with alanine aminotransferase (ALT). It is necessary to stress that the activity of this enzyme decreased also on the first day after irradiation. Until the third day there was a marked increase of serum corticosterone in the irradiated animals. The results point not only towards significant changes to the parameters observed, caused by a non-lethal irradiation dose, but also towards the importance of the nutritional regime, so-called paired feeding

  19. Functional and structural alterations of epithelial barrier properties of rat ileum following X-irradiation

    International Nuclear Information System (INIS)

    Dublineau, I.; Lebrun, F.; Grison, S.; Griffiths, N.M.

    2004-01-01

    Irradiation of the digestive system leads to alterations of the small intestine. We have characterized the disruption of the barrier integrity in rat ileum from 1 to 14 days following irradiation ranging from 6 to 12 Gy. The intestinal permeability to 14 C-mannitol and 3 H-dextran 70,000 was measured in vitro in Ussing chambers. In parallel to these functional studies, immunohistochemical analyses of junctional proteins (ZO-1 and β-catenin) of ileal epithelium were performed by confocal microscopy. Irradiation with 10 Gy induced a marked decrease in epithelial tissue resistance at three days and a fivefold increase in mannitol permeability, without modifications of dextran permeability. A disorganization of the localization for ZO-1 and β-catenin was also observed. At 7 days after irradiation, we observed a recovery of the organization of junctional proteins in parallel to a return of intestinal permeability to control value. In addition to these time-dependent effects, a gradual effect on epithelial integrity of the radiation doses was observed 3 days after irradiation. This study shows a disruption of the integrity of the intestinal barrier in rat ileum following abdominal X-irradiation, depending on the time postirradiation and on the delivered dose. The loss of barrier integrity was characterized by a disorganization of proteins of tight and adherent junctions, leading to increased intestinal permeability to mannitol. (author)

  20. Brightness discrimination learning in a Skinner box in prenatally X-irradiated rats

    International Nuclear Information System (INIS)

    Tamaki, Y.; Inouye, M.

    1976-01-01

    Male MP 1 albino rats were exposed to x-irradiation in utero at a single dose of 200 R on day 17 of gestation. The light-dark discrimination training in a Skinner box was continued until the animals attained a learning criterion of 0.80 correct response ratio for 3 consecutive days. Although during the unreinforced baseline sessions the total number of bar pressings in the irradiated animals was superior to that in the controls, performance between the control and the irradiated animals did not differ significantly in (a) the number of training days required to attain the learning criterion, (b) the total number of days on which the animals produced a correct response ratio more than 0.80, and (c) the number of consecutive days during which the correct response ratio was more than 0.75. The results obtained suggest that the irradiated animals were able to discriminate in brightness cues as well, or nearly as well, as the controls. The cortical-subcortical system mediating brightness discrimination in the irradiated animals is discussed. (author)

  1. 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

  2. Reactivation of Immunological Response in Lethally X-Irradiated Mice Treated with Isogeneic Bone Marrow

    Energy Technology Data Exchange (ETDEWEB)

    Stankovic, V.; Slijepcevic, M.; Hrsak, I. [Institute Ruder Boskovic, Zagreb, Yugoslavia (Croatia)

    1968-08-15

    Male and female C57BL/H and CBA/H mice aged 10-12 weeks were used as recipients and donors, respectively. All recipient mice were given a lethal whole-body X-irradiation dose (850 R for C57BL and 950 R for CBA mice) followed by iv injection of 10 x 106 isogeneic eosin-negative bone-marrow cells suspended in 0.5 ml of Hank's solution. The number of eosin-positive cells was less than 10%. The state of immunological responsiveness of irradiated recipients was measured at different time intervals up to 86 days after irradiation. The immune response to bacterial antigen was measured with the titre of agglutinating antibodies in serum six days after iv antigenic stimulation with a suspension of 2 x 10{sup 7} killed Salmonella typhimurium cells. The immune response to tissue antigens was evaluated by: (a) the effectiveness of the spleen cells from isologous radiation chimeric parental mice in preventing bone marrow from F{sub 1} (C57BL x CBA) hybrid donor from therapeutically affecting lethally irradiated F j recipient mice; (b) the effectiveness of the spleen cells in inducing splenom egaly in recipient F{sub 1} hybrid mice (Simonsen test). It was found that the responsiveness to bacterial antigens reappears much earlier and increases much faster than the immunological responsiveness to tissue antigens. (author)

  3. Immunomodulatory Properties and Molecular Effects in Inflammatory Diseases of Low-Dose X-Irradiation

    International Nuclear Information System (INIS)

    Rödel, Franz; Frey, Benjamin; Manda, Katrin; Hildebrandt, Guido; Hehlgans, Stephanie; Keilholz, Ludwig; Seegenschmiedt, M. Heinrich; Gaipl, Udo S.; Rödel, Claus

    2012-01-01

    Inflammatory diseases are the result of complex and pathologically unbalanced multicellular interactions. For decades, low-dose X-irradiation therapy (LD-RT) has been clinically documented to exert an anti-inflammatory effect on benign diseases and chronic degenerative disorders. By contrast, experimental studies to confirm the effectiveness and to reveal underlying cellular and molecular mechanisms are still at their early stages. During the last decade, however, the modulation of a multitude of immunological processes by LD-RT has been explored in vitro and in vivo. These include leukocyte/endothelial cell adhesion, adhesion molecule and cytokine/chemokine expression, apoptosis induction, and mononuclear/polymorphonuclear cell metabolism and activity. Interestingly, these mechanisms display comparable dose dependences and dose-effect relationships with a maximum effect in the range between 0.3 and 0.7 Gy, already empirically identified to be most effective in the clinical routine. This review summarizes data and models exploring the mechanisms underlying the immunomodulatory properties of LD-RT that may serve as a prerequisite for further systematic analyses to optimize low-dose irradiation procedures in future clinical practice.

  4. Immunomodulatory Properties and Molecular Effects in Inflammatory Diseases of Low-Dose X-Irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Rödel, Franz [Department of Radiotherapy and Oncology, University Hospital of Frankfurt, Johann Wolfgang-Goethe Universität, Frankfurt am Main (Germany); Frey, Benjamin [Department of Radiation Oncology, University Hospital Erlangen, Friedrich-Alexander Universität Erlangen-Nürnberg, Erlangen (Germany); Manda, Katrin; Hildebrandt, Guido [Department of Radiotherapy and Radiation Oncology, University of Rostock, Rostock (Germany); Hehlgans, Stephanie [Department of Radiotherapy and Oncology, University Hospital of Frankfurt, Johann Wolfgang-Goethe Universität, Frankfurt am Main (Germany); Keilholz, Ludwig [Department of Radiotherapy, Clinical Center Bayreuth, Bayreuth (Germany); Seegenschmiedt, M. Heinrich [Strahlenzentrum Hamburg Medizinisches Versorgungszentrum, Hamburg (Germany); Gaipl, Udo S. [Department of Radiation Oncology, University Hospital Erlangen, Friedrich-Alexander Universität Erlangen-Nürnberg, Erlangen (Germany); Rödel, Claus, E-mail: franz.roedel@kgu.de [Department of Radiotherapy and Oncology, University Hospital of Frankfurt, Johann Wolfgang-Goethe Universität, Frankfurt am Main (Germany)

    2012-09-25

    Inflammatory diseases are the result of complex and pathologically unbalanced multicellular interactions. For decades, low-dose X-irradiation therapy (LD-RT) has been clinically documented to exert an anti-inflammatory effect on benign diseases and chronic degenerative disorders. By contrast, experimental studies to confirm the effectiveness and to reveal underlying cellular and molecular mechanisms are still at their early stages. During the last decade, however, the modulation of a multitude of immunological processes by LD-RT has been explored in vitro and in vivo. These include leukocyte/endothelial cell adhesion, adhesion molecule and cytokine/chemokine expression, apoptosis induction, and mononuclear/polymorphonuclear cell metabolism and activity. Interestingly, these mechanisms display comparable dose dependences and dose-effect relationships with a maximum effect in the range between 0.3 and 0.7 Gy, already empirically identified to be most effective in the clinical routine. This review summarizes data and models exploring the mechanisms underlying the immunomodulatory properties of LD-RT that may serve as a prerequisite for further systematic analyses to optimize low-dose irradiation procedures in future clinical practice.

  5. Kinetically directed combination therapy with adriamycin and x-irradiation in a mammary tumor model

    International Nuclear Information System (INIS)

    Braunschweiger, P.G.; Schenken, L.L.; Schiffer, L.M.

    1981-01-01

    In the present studies, the interaction of adriamycin (A) and x-irradiation (X) in T1699 mouse mammary tumors was evaluated. Mitotic indices and thymidine labeling indices were determined at various intervals after A or X alone, and after A + X given in combination. The results with A (1.0 mg/kg) and X(200 R) alone suggest that those quantities of each agent induce a G 2 progression delay of 9 to 12 h. The kinetic results after A + X in combination indicated increased S phase transit time and G 2 progression delay. Recovery kinetics after A + X were used to predict optimum sequence intervals for subsequent A + X fractions. Sequential A + X treatment schedules, up to 4 fractions, were designed and evaluated by regrowth delay measurements. The results indicated that the interaction was additive when A and X were given together in combination. Fractionation of A + X to minimize proliferative recovery between fractions resulted in an enhanced antitumor effect

  6. 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.)

  7. Effects of x-irradiation of young female beagles on life span and tumor incidence

    International Nuclear Information System (INIS)

    Rosenblatt, L.S.; Book, S.A.; Goldman, M.

    1986-01-01

    Causes of death and the occurrence of neoplasia in female beagle dogs were evaluated retrospectively for 57 unexposed and 296 exposed dogs given single or fractionated whole-body x-irradiation exposures of 100 or 300 R. Some dogs subsequently were bred, and all were observed for the duration of their lives. The pathology for these dogs was derived from clinical records, gross-necropsy reports, tissue slides, and Formalin-fixed tissues. The results of this study indicated dose-related shortening of life span was clearly evident; causes of death due to either neoplasia (50%) or nonneoplastic disease (50%), with few exceptions, were similar in control and irradiated dogs; the incidences of neoplasms were not significantly greater for irradiated dogs than for controls, but the latency period decreased as dose increased; protraction increased survival in dogs given 300 R but not 100 R, which is attributable solely to amelioration of incidence rates of nonmammary neoplasia; and the cumulative rates of death due to mammary tumors were the same in dogs exposed to 100 R and 300 R. 14 refs., 6 figs., 2 tabs

  8. Response of irradiated diet fed rats to whole body X irradiation

    International Nuclear Information System (INIS)

    Hasan, S.S.; Kushwaha, A.K.S.

    1985-01-01

    The response to whole body X irradiation has been studied in the brain of rats fed both on a normal diet (consisting of equal parts of wheat and gram flour) and on a low protein irradiated diet (consisting of a part of normal diet and three parts of wheat). The activity of enzymes related to the glucose metabolism (glucose 6-phosphate dehydrogenase and fructose diphosphate aldolase) is reduced, while that of peroxidant enzymes (catalase and lipid peroxidase) increased in the brain of rats that received a diet poor in proteins and irradiated diets (normal or hypoproteic). DNA and RNA levels and protein content show a significant reduction in the brain of rats with hypoproteic and irradiated diets. The total body irradiation causes serious alterations in the brain in animals with a hypoproteic malnutritions due both to a low protein and an irradiated diet. The brain of rats fed on a low protein and irradiated diet exhibits after whole body irradiation damages more severe than those in rats fed on a normal irradiated diet

  9. Effects of sex hormones on induction of intestinal metaplasia by X-irradiation in rats

    International Nuclear Information System (INIS)

    Watanabe, Hiromitsu; Okamoto, Taro; Matsuda, Masahiro; Takahashi, Tadateru; Ogundigie, P.S.; Ito, Akihiro

    1993-01-01

    The influence of sex hormones on induction of intestinal metaplasia was examined in 5 week old Crj:CD (SD) rats of both sexes. At the age of 4 weeks, the animals were gonadectomized and given testosterone or dimethyl estradiol (DES). One week after operation, they were irradiated with two 10 Gy doses of X-rays to the gastric region at a 3 day interval for a total of 20 Gy. At the termination of the experiment, 6 months after the X-irradiation, the incidence of intestinal metaplasia with alkaline phosphatase (ALP) positive foci in males was significantly higher than in females, in orchidectomized males or orchidectomized plus DES treated rats (P<0.01). On the other hand, the incidence of intestinal metaplasia with ALP-positive foci in normal females appeared lower than in ovariectomized females (P<0.01), and was increased in rats by treatment with testosterone or decreased by DES. Numbers of foci of intestinal metaplasias with Paneth cells and total numbers appeared to increase in males treated with DES. The results suggested a promising role for testosterone in the development of ALP positive lesions and indicated considerable heterogeneity between intestinal metaplasia subtypes. (author)

  10. N-ethylmaleimide sensitization of x-irradiated hypoxic Chinese hamster cells

    International Nuclear Information System (INIS)

    Kimler, B.F.; Sinclair, W.K.; Elkind, M.M.

    1977-01-01

    Chinese hamster cells were x irradiated either aerobically or hypoxically, after flushing with nitrogen plus carbon dioxide. In agreement with earlier data, for asynchronous cells, the oxygen enhancement ratio (OER) was approximately three. If the sulfhydryl-binding agent N-ethylmaleimide (NEM) was present during or immediately after irradiation, the principal effect was a pronounced decrease in the extrapolation number of the survival curve of NEM-treated cells compared to nontreated cells. This was observed with hypoxic as well as aerobic cells and the OER for NEM-treated cells was also about three. For NEM treatments which were essentially nontoxic, NEM acts synergistically with X rays, suggestive of an inhibition by NEM of a cell's ability to repair sublethal damage. For synchronous cells obtained by mitotic selection, a result consistent with the above was obtained; a dose three times as large was necessary to reduce survival to the same level for hypoxic cells as for aerobic cells, whether or not the cells were treated with NEM. Thus the OER was independent of NEM treatment throughout the cell cycle, with the possible exception of mitosis which could not be studied with the methods used. It is concluded that the action of NEM at low concentrations (0.75 μM) is largely independent of oxygen tension. Oxygen acts to produce more damage per unit dose in the cell while NEM sensitizes apparently by preventing the repair of sublethal damage

  11. Oscillations of serum and tissue lipids in rats X-irradiated at different times of day

    International Nuclear Information System (INIS)

    Ahlers, I.; Ahlersova, E.; Toropila, M.; Smajda, B.; Praslicka, M.

    1983-01-01

    Young male Wistar rats (mean body mass 200 g) adapted to a 12:12 h light:dark regimen (7 a.m. to 7 p.m., 7 p.m. to 7 a.m.) were X-irradiated at 3-h intervals during one day with doses of 2.39 or 14.25 Gy and were killed 48 or 24 h afterwards. Nonesterified fatty acids were determined in their serum and white and brown adipose tissue, and triacylglycerols, phospholipids and total cholesterol in their serum and liver. The reaction of serum and tissue lipids during the day varied after both non-lethal and lethal irradiation. After non-lethal exposure, most of the curves, as regards their course, the presence of rhythm and their oscillation properties, concurred with the lipid indicator curves in the control series and indicated that the organism's response is dependent on the time of day. Circadian variation of serum and adipose tissue nonesterified fatty acid levels, the liver triacylglycerol concentration and the adrenal cholesterol concentration in lethally irradiated animals showed no significant dependence on the time of application of the stimulus. An analysis of circadian variation of the effectiveness of a stimulus facilitates understanding of the organism's reactivity better than a single examination in the morning. (author)

  12. An unexpected response of torulopsis glabrata fusion products to x-irradiation

    International Nuclear Information System (INIS)

    Galeotti, C.L.; Sriprakash, K.S.; Batum, C.M.; Clark-Walker, G.D.

    1981-01-01

    Intra-species fusion products of Saccharomyces cerevisiae, Saccharomyces unisporus and Torulopsis glabrata have been isolated following polyethylene glycol-induced fusion of protoplasts and selection for prototrophic colonies. Staining with lomofungin showed that all fusion products were uninucleate. Measurement of DNA content mostly gave values between haploid and diploid levels indicating that the majority of fusion products were aneuploid. Nevertheless fusion products of S. cerevisiae and S. unisporus were, as expected, more resistant to X-irradiation than their haploid parents. By contrast, the X-ray doze-response curve of all T. glabrata fusion products was indistinguishable from their progenitors despite the fact that mitotic segregants could be recovered amongst the survivors to X-rays. A possible explanation for the behaviour towards X-rays of T. glabrata fusion products is that this species lacks a DNA repair pathway involving recombination between homologous chromosomes. We conclude from this study that the shape of the X-ray dose-response curve should not be taken to indicate the ploidy of new yeast isolates without supporting data. (orig.)

  13. Sertoli cell death by apoptosis in the immature rat testis following x-irradiation

    International Nuclear Information System (INIS)

    Allan, D.J.; Gobe, G.C.; Harmon, B.V.

    1988-01-01

    The importance of the morphological study of cell death has recently been emphasized by the recognition that the ultrastructural features of dying cells allow categorization of the death as either apoptosis or necrosis. This classification enables inferences to be drawn about the mechanism and biological significance of the death occurring in a particular set of circumstances. In this study, Sertoli cell death induced in the immature testis of three and four day old rats by 5 Gy (500 rads) x-irradiation was described by light and transmission electron microscopy with the objective of categorizing the death as apoptosis or necrosis. The testes were examined 1, 2, 3, 4, 8, and 24 h after irradiation. Following irradiation, there was a wave of apoptosis of the Sertoli cells starting in three to four hours and reaching a peak between four and eight hours. At 24 hours, only 61% of the expected number of Sertoli cells remained. These findings are in accord with recent ultrastructural reports that ionizing radiation induces cell death by apoptosis in rapidly proliferating cell populations. New insights into the pathogenesis of radiation-induced cell death might thus be expected to stem from future elucidation of the general molecular events involved in triggering apoptosis

  14. Physiological and pharmacological properties of Purkinje cells in rat cerebellum degranulated by postnatal x irradiation

    International Nuclear Information System (INIS)

    Woodward, D.J.; Hoffer, B.J.; Altman, J.

    1974-01-01

    Elimination of most granule, basket, and stellate interneurons in the rat cerebellum was achieved by repeated doses of low level x irradiation applied during the first two weeks of postnatal life. Purkinje neurons in these rats, studied when adults, exhibited sustained spiking activity in Halothane anesthetized preparations. Mean firing rates were 35 to 40/sec, no different from normal. Spontaneous bursts presumed to be generated by climbing fiber synaptic activity differed from normal by often consisting of full sized spikes rather than characteristic inactivation responses. Intracellularly observed correlates of bursts consisted of epsp's of several discretely different amplitudes appearing independently in time. Stimulation of white matter revealed evidence for, a) graded synaptic excitation of Purkinje cells indicating more than one converging excitatory synapse, and b) inhibitory actions on Purkinje cells either through a few remaining inhibitory interneurons or through Purkinje cell recurrent collaterals. Iontophoretic drug application studies showed normal chemosensitivity of the Purkinje cell membrane, i.e., excitation by flutamate and inhibition by gamma-amino butyric acid, serotonin, norepinephrine, and 3'5' cyclic AMP. These studies indicate considerable autonomy of Purkinje cell ontogenesis in the absence of normal interneuronal input. A unique synaptic relation only rarely found in normal cerebellum is the innervation of single Purkinje cells by more than one climbing fiber. (U.S.)

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

    Energy Technology Data Exchange (ETDEWEB)

    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. Types of structural chromosome aberrations and their incidences in human spermatozoa X-irradiated in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Kamiguchi, Yujiroh; Tateno, Hiroyuki; Mikamo, Kazuya (Asahikawa Medical College (Japan). Department of Biological Sciences)

    1990-02-01

    The authors studied the effects of in vitro X-irradiation on human sperm chromosomes, using our interspecific in vitro fertilization system between human spermatozoa and zona-free hamster oocytes. 28 semen samples from 5 healthy men were exposed to 0.23, 0.45, 0.91 and 1.82 Gy of X-rays. Totals of 2098 and 2862 spermatozoa were karyotyped in the control and the irradiated groups, respectively. The indicence of spermatozoa with X-ray-induced structural chromosome aberrations (Y) increased linearly with increasing dosage (D), being best expressed by the equation, Y = 0.08 + 34.52 D. The incidence of breakage-type aberrations was moe than 9 times higher than that of exchange-type aberrations. Both of them showed linear dose-dependent increases, which were expressed by the regression lines, Y = -0.014 + 0.478 D and Y -0.010 + 0.057 D, respectively. The incidence of chromosome-ltype aberrations was about 6 times higher than that of chromatid-type aberrations. Their dose-dependent increases were expressed by the regression lines, Y = -0.015 + 0.462 D and Y = -0.006 + 0.079 D, respectively. These results are discussed in relation to the previous data obtained with {gamma}-rays. The repair mechanism of X-ray-induced sperm DNA lesions is also discussed. (author). 21 refs.; 4 figs.; 4 tabs.

  17. Skin response to X-irradiation in the guinea-pig

    Energy Technology Data Exchange (ETDEWEB)

    Berry, R J; Mole, R H; Barnes, D W.H. [Medical Research Council, Harwell (UK). Radiobiological Research Unit

    1976-12-01

    Skin reaction to X-irradiation has been studied in the albino quinea-pig; early response in limited-field irradiations of the flank was comparable to that commonly seen in rodents, swine and man, and was dose-dependent with a dynamic range from mild erythema to moist desquamation. The peak early skin reaction was seen between 14 and 21 days after irradiation, and declined before 30 days except at the highest doses used. Fractionation of the X-ray dose at 24 hours resulted in a 'sparing' of about 340 rad. Permanent partial epilation was detectable at doses in excess of 1400 rad, and complete epilation at 1 year occurred in 50 per cent of irradiated fields at 1740 rad. Twenty-four hour two-dose fractionation resulted in a 'sparing' of about 500 rad for epilation. Palpable dermal 'fibrosis' was detectable at 3 months after irradiation in fields given more than 2070 rad, and at 1 year after irradiation in fields given more than 1800 rad; 50 per cent of fields showed palpable 'fibrosis' at 1 year at 1930 rad. Unlike domestic swine and man, skin fields in the quinea-pig showed no dimensional contraction after X-ray doses which produced gross early skin damage.

  18. Enzyme release in the skin of mice as an effect of soft X-irradiation

    International Nuclear Information System (INIS)

    Soltesz, L.

    1976-01-01

    The shaved skin of 7-8 week old male mice was irradiated locally on the back by doses of 100, 500, 1000, 2000 or 4000 R of soft X-ray. The enzyme activity of the washing solution and of the homogenate of the removed skin, the nitrogen content and the incorporation of 3 H-thymidine were measured immediately after irradiation or 1,2,4,8,16 hours later. The activity of lysosomal enzymes (acid phosphatase, beta-glucuronidase, cathepsine D) increased in the washing solution, whereas in the homogenate no significant change was observed. The maximal values were measured on the second day after irradiation with 1000 R. Tha activity of alkaline phosphatase and leucinaminopeptidase (non-lysosomal enzymes) did not change. Neither was any change observed in the nitrogen content of the skin. The incorporation of 3 H-thymidine considerably decreased. It can be concluded that small doses (500-1000 R) of local X-irradiation damage the membrane of lysosoms and lead to a release of cell destructing enzymes. (L.E.)

  19. 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.)

  20. The induction of micronuclei in X-irradiated Beagle dog lymphocytes

    International Nuclear Information System (INIS)

    Rithidech, K.; Lozano, D.; Brooks, A.L.

    1988-01-01

    We developed a simple, sensitive, and reproducible method using the micronucleus assay in dog blood lymphocytes for detecting genotoxic effects of ionizing radiation. Micronuclei (MM) are expressed in cells that have undergone 1 cell division. Thus, it was important to determine the optimum culture condition and sampling time to obtain a maximum number of such cells. To identify cells that have divided, cytochalasin B was added to block cytokinesis. Cells were harvested at 72, 76, or 94 h after incubation with different concentrations of phytohaemagglutinin (PHA) 15 or 16. After optimizing the culture time and PHA concentration, the system was calibrated by evaluating the dose response for the induction of MN by X rays. Blood samples were drawn, X-irradiated (0.0, 0.5, 1.0, 2.0, or 4.0 Gy), grown in optimum culture medium, harvested at 94 h after incubation, and the frequency of MN analyzed in binucleated cells. The dose-response relationship was fit by a quadratic model; micronuclei/binucleated cell = 0.017 + 0.046D + 0.0093D 2 , where D = dose. The MN assay in dog blood lymphocytes provides a sensitive and reliable technique for measuring genotoxic damage in a large animal model. The MN assay will be very useful for evaluating genotoxic effects of hazardous agents after both chronic and acute exposures and for estimating radiation dose. (author)

  1. W-reactivation of phage lambda in X-irradiated mutants of Escherichia coli K-12

    Energy Technology Data Exchange (ETDEWEB)

    Martignoni, K D; Haselbacher, I [Muenchen Univ. (Germany, F.R.). Strahlenbiologisches Inst.

    1980-07-01

    The survival of UV irradiated phage lambda was increased on X-irradiated E.coli K-12 host cells over that on unirradiated cells. The frequency of c mutants among the surviving phages was increased to a similar extent by the X-ray exposure of the host cells as by UV light. This W-reactivation of phage lambda occurred in uvrA, polA, and recB mutants besides the wild type at about equal X-ray doses, but at a reduced reactivation efficiency compared with the wild type. W-reactivation was undetectable in recA mutants. While maximal UV induced W-reactivation occured 30 min after irradiation, the maximal X-ray induced reactivation was found immediately after irradiation. Chloramphenicol (100 ..mu..g/ml) and nitrofurantoin (50 ..mu..g/ml) inhibited W-reactivation of phage lambda if added before irradiation of the host cells, indicating the necessity of protein synthesis for W-reactivation.

  2. Growth hormone and somatomedin effects on calcification following X-irradiation, glucocorticoid treatment or fasting

    International Nuclear Information System (INIS)

    Dearden, L.C.; Mosier, H.D. Jr.

    1986-01-01

    Growth hormone (GH) is thought to activate the liver to produce a peptide called somatomedin (SM) and this substance putatively stimulates linear growth in long bones by its action on cartilagenous epiphyseal plates. These actions include stimulating chondrocytes to synthesize the carbohydrate and protein components of proteoglycan and of collagen, enhancing the synthesis of ribo and desoxyribonucleic acids, and possibly to increase cell division. In GH deficiencies there is a narrowing of the epiphyseal growth plate and cartilage calcification is enhanced concurrent with proteoglycan and collagen alterations in the extracellular matrix. Calcium and phosphate ions accumulate in mitochondria followed by their release as the calcification zone is approached, and matrix vesicles, which possess the chemical machinery necessary to induce the format0344of apatite crystals within them, increase. Therefore, if GH and/or SM levels are altered, there should be corresponding alterations in growth or in cartilage calcification. In the present study we have investigated rats after head X-irradiation, fasting, and corticosteroid treatment, and all of these treatments reduce GH and SM. (Auth.)

  3. Physiological properties of afferents to the rat cerebellum during normal development and after postnatal x irradiation

    International Nuclear Information System (INIS)

    Puro, D.G.

    1975-01-01

    The consequences of an altered cerebellar cortical development on afferent transmission and terminal organization were analyzed in adult rats which had received x irradiation to the cerebellum postnatally. Rats, anesthetized with 0.5 percent halothane, were studied in various ages from day 3 to adult. The ascending mossy and climbing fiber systems were activated by electrical stimulation of the limbs with needle electrodes. Stimulation of the motor cortex activated the descending climbing fiber pathways. Extracellular responses from cerebellar Purkinje cells were observed on an oscilloscope as poststimulus time histograms were constructed ''on-line''. Conclusions and assertions include: (1) Synaptogenesis between incoming afferent fibers and target neurons takes place early in cerebellar cortical development. (2) Mossy fiber transmission is mature before the bulk of cerebellar synaptogenesis occurs. (3) The ascending and descending components of the climbing fiber system mature, with respect to latency, in synchrony. (4) The terminal synaptic organization has little effect on the development of transmission characteristics in these afferent systems. (5) One possible mechanism by which an adult neural structure can have an abnormal synaptic organization is to maintain immature synaptic relationships due to the neonatal loss of interneurons

  4. Survival of human diploid skin fibroblasts from normal individuals after X-irradiation

    International Nuclear Information System (INIS)

    Little, J.B.; Nove, J.; Strong, L.C.; Nichols, W.W.

    1988-01-01

    The cytotoxic effect of X-rays was measured by a colony formation assay in multiple experiments with fibroblast cell strains derived from 24 presumably normal individuals, received as 65 different coded and blinded samples. Each strain was received on two or more occasions at different times and bearing different codes. The means and standard deviations of the survival curve parameters for the 24 strains were: D 0 = 123 +- 23; D 10 = 273 +- 42 cGy. The D 0 ranged from 89 to 175 and the D 10 from 196 to 372 cGy. The degree of interexperimental variation, though generally minimal, differed considerably among cell strains. There was no systematic effect of passage level, cloning efficiency, serum lot, age or sex of the donor on X-ray survival. These results confirm that the intrinsic radiosensitivity varies significantly among skin fibroblasts isolated from clinically normal individuals, apparently owing to as yet unidentified genetic factors. (Author)

  5. Indirect effects are involved in the production of potentially lethal damage in X irradiated escherichia coli

    International Nuclear Information System (INIS)

    Billen, D.

    1985-01-01

    When living cells are exposed to low LET radiation, 60 to 70% of the resulting lethality is said to be due to indirect effects. Using the OH radical scavengers: glycerol n-butanol, t-butanol, and NO/sub 2//sup -/. The authors observed that a radiosensitive E. coli K-12 mutant (W 3110 thy/sup -/ polAl/sup -/) lacking DNA polymerase 1 displays a markedly enhanced radioresistance when exposed to X rays in the presence of these chemicals. The extent of protection afforded by these chemicals correlated with their OH radical scavenging ability over the limited range of concentrations of the chemicals studied. (Only non-toxic concentrations of the chemicals were used). The presence of 2M glycerol during irradiation of the PolAl/sup -/ cells results in a survival level higher than that seen for the unprotected parent strain (W 3110 thy polA/sup +/)

  6. 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

  7. Effect of RNAi p21 gene on uncoupling of EL-4 cells induced by X-irradiation

    International Nuclear Information System (INIS)

    Ju Guizhi; Yan Fengqin; Fu Shibo; Shen Bo; Sun Shilong; Yang Ying; Li Pengwu

    2008-01-01

    Objective: To investigate the effect of RNAi p21 gene on uncoupling of EL-4 cells induced by X-irradiation. Methods: Construction of RNAi p21 plasmid of pSileneer3.1-H1 neo-p21 was performed. Lipofectamine transfection assay was used to transfer the p21siBNA into EL-4 cells. Fluorescent staining and flow cytometry (FCM) analysis were employed for measurement of protein expression. Fluorescent staining of propidium iodide (PI) and FCM were used for measurement of potyploid cells. Results: In dose-effect experiment it was found that the expression of P21 protein of EL-4 cells increased significantly 24 h after X- irradiation with different doses compared with sham-inadiated control. In time course experiment it was found that the expression of P21 protein of EL-4 cells increased significantly at 8 h to 72 h after 4.0 Gy X-irradiation compared with sham-irradiated control. The results showed that the number of polyploid cells in EL-4 cells was not changed markedly after X-irradiation with doses of 0.5-6.0 Gy. After RNA interference with p21 gene, the expression of P21 protein of EL-4 cells decreased significantly 24 h and 48 h after 4.0 Gy X-irradiation in transfection of plasmid of pSilencer3.1-H1 neo-p21 compared with transfection of plasmid of pSilencer3.1-H1 nco control. And at the same time, the number of polyploid cells in EL-4 cells was increased significantly in transfection of plasmid of pSilencer3.1-H1 neo-p21 compared with transfection of plasmid of pSilencer3.1-H1 nco control. Conclusions: Uncoupling could be induced by X-irradiation in EL-4 cells following BNAi p21 gene, suggesting that P21 protein may play an important role in uncoupling induced by X-rays. (authors)

  8. Similarity between the effects of carbon-ion irradiation and X-irradiation on the development of rat brain

    International Nuclear Information System (INIS)

    Inouye, Minoru; Hayasaka, Shizu; Murata, Yoshiharu; Takahashi, Sentaro; Kubota, Yoshihisa

    2000-01-01

    The effects of carbon-ion irradiation and X-irradiation on the development of rat brain were compared. Twenty pregnant rats were injected with bromodeoxyuridine (BrdU) at 9 pm on day 18 pregnancy and divided into five groups. Three hours after injection (day 19.0) one group was exposed to 290 MeV/u carbon-ion radiation by a single dose of 1.5 Gy. Other groups were exposed to X-radiation by 1.5, 2.0 or 2.5 Gy, or sham-treated, respectively. Fetuses were removed from one dam in each group 8 h after exposure and examined histologically. Extensive cell death was observed in the brain mantle from the irradiated groups. The cell death after 1.5 Gy carbon-ion irradiation was remarkably more extensive than that after 1.5 Gy X-irradiation, but comparable to that after 2.0 Gy or 2.5 Gy X-irradiation. The remaining rats were allowed to give birth and the offspring were sacrificed at 6 weeks of age. All of the irradiated offspring manifested microcephaly. The size of the brain mantle exposed to 1.5 Gy carbon-ion radiation was significantly smaller than that exposed to 1.5 Gy X-radiation and larger than that exposed to 2.5 Gy X-radiation. A histological examination of the cerebral cortex revealed that cortical layers II-IV were malformed. The defect by 1.5 Gy carbon-ion irradiation was more severe than that by the same dose of X-irradiation. Although the BrdU-incorporated neurons were greatly reduced in number in all irradiated groups, these cells reached the superficial area of the cortex. These findings indicated that the effects of both carbon-ion irradiation and X-irradiation on the development of rat brain are similar in character, and the effect of 1.5 Gy carbon-ion irradiation compares to that of 2.0-2.5 Gy X-irradiation. (author)

  9. Radiosensitivity in cultured human fibroblasts

    International Nuclear Information System (INIS)

    Cox, R.; Masson, W.K.

    1980-01-01

    Caution is urged in the use of freshly isolated cultures of human diploid fibroblasts for quantitative studies of radiosensitivity. The distribution of x ray sensitivities of 'normal' human fibroblast cultures of foetal origin (10 subjects, skin or lung biopsy) and post-foetal origin (34 subjects, skin biopsy) are compared with the distribution in 12 patients with ataxia telangiectasia (probability of including any one of these in a normal post-foetal distribution is 0.01%). Cultures from nominally normal subjects showed a broad distribution of D 0 range of 98 +- 160 rad and assuming normal distribution, a mean +- one standard deviation of 122 +- 17 rad. Mean D 0 values for foetal origin cultures were 117 +- 12; values for post-foetal cultures D 0 were 124 +- 18. No systematic variation in D 0 was observed for age of donor, number of cell divisions in culture or for cloning efficiency. For ataxia telangiectasia D 0 values were 46 +- 7 rad. (U.K.)

  10. DNA damage repair and radiosensitivity

    International Nuclear Information System (INIS)

    Suzuki, Norio

    2003-01-01

    Tailored treatment is not new in radiotherapy; it has been the major subject for the last 20-30 years. Radiation responses and RBE (relative biological effectiveness) depend on assay systems, endpoints, type of tissues and tumors, radiation quality, dose rate, dose fractionation, physiological and environmental factors etc, Latent times to develop damages also differ among tissues and endpoints depending on doses and radiation quality. Recent progress in clarification of radiation induced cell death, especially of apoptotic cell death, is quite important for understanding radiosensitivity of tumor cure process as well as of tumorigenesis. Apoptotic cell death as well as dormant cells had been unaccounted and missed into a part of reproductive cell death. Another area of major progress has been made in clarifying repair mechanisms of radiation damage, i.e., non-homologous end joining (NHEJ) and homologous recombinational repair (HRR). New approaches and developments such as cDNA or protein micro arrays and so called informatics in addition to basic molecular biological analysis are expected to aid identifying molecules and their roles in signal transduction pathways, which are multi-factorial and interactive each other being involved in radiation responses. (authors)

  11. Effect of hypothermia on radiosensitization

    International Nuclear Information System (INIS)

    Nias, A.H.W.; Perry, P.; Photiou, A.; Reghebi, K.

    1986-01-01

    The blood supply and oxygen tension have been measured in C3H mouse mammary tumours under hypothermia and hyperbaric oxygen, and the enhancement of radiosensitivity by hyperbaric oxygen has been estimated in mice irradiated at different temperatures with and without anaesthesia. Measurement of xenon-133 clearance showed that the blood supply of a tumour tended to increase when anaesthetized mice became hypothermic. Oxygen cathode data showed that the oxygen tension tended to be relatively higher in tumours and lower in subcutaneous tissue when mice exposed to hyperbaric oxygen became hypothermic under anaesthesia. Hyperbaric oxygen enhanced the radiation response of the tumour in terms of an increase in regrowth delay by a factor of 1.7 when the mice had been anaesthetized, whether or not they became hypothermic. A lower factor of 1.4 was obtained without anaesthesia although induced hypothermia increased the response to a small extent. The authors conclude that anaesthesia and hypothermia affect oxygen metabolism in tumours by different mechanisms. (author)

  12. A single whole-body low dose X-irradiation does not affect L1, B1 and IAP repeat element DNA methylation longitudinally.

    Directory of Open Access Journals (Sweden)

    Michelle R Newman

    Full Text Available The low dose radioadaptive response has been shown to be protective against high doses of radiation as well as aging-induced genomic instability. We hypothesised that a single whole-body exposure of low dose radiation would induce a radioadaptive response thereby reducing or abrogating aging-related changes in repeat element DNA methylation in mice. Following sham or 10 mGy X-irradiation, serial peripheral blood sampling was performed and differences in Long Interspersed Nucleic Element 1 (L1, B1 and Intracisternal-A-Particle (IAP repeat element methylation between samples were assessed using high resolution melt analysis of PCR amplicons. By 420 days post-irradiation, neither radiation- or aging-related changes in the methylation of peripheral blood, spleen or liver L1, B1 and IAP elements were observed. Analysis of the spleen and liver tissues of cohorts of untreated aging mice showed that the 17-19 month age group exhibited higher repeat element methylation than younger or older mice, with no overall decline in methylation detected with age. This is the first temporal analysis of the effect of low dose radiation on repeat element methylation in mouse peripheral blood and the first to examine the long term effect of this dose on repeat element methylation in a radiosensitive tissue (spleen and a tissue fundamental to the aging process (liver. Our data indicate that the methylation of murine DNA repeat elements can fluctuate with age, but unlike human studies, do not demonstrate an overall aging-related decline. Furthermore, our results indicate that a low dose of ionising radiation does not induce detectable changes to murine repeat element DNA methylation in the tissues and at the time-points examined in this study. This radiation dose is relevant to human diagnostic radiation exposures and suggests that a dose of 10 mGy X-rays, unlike high dose radiation, does not cause significant short or long term changes to repeat element or global DNA

  13. Targeted radiosensitization of cells expressing truncated DNA polymerase {beta}.

    NARCIS (Netherlands)

    Neijenhuis, S.; Verwijs-Janssen, M.; Broek, Bart van den; Begg, A.C.; Vens, C.

    2010-01-01

    Ionizing radiation (IR) is an effective anticancer treatment, although failures still occur. To improve radiotherapy, tumor-targeted strategies are needed to increase radiosensitivity of tumor cells, without influencing normal tissue radiosensitivity. Base excision repair (BER) and single-strand

  14. Hyperthermic radiosensitization : mode of action and clinical relevance

    NARCIS (Netherlands)

    Kampinga, HH; Dikomey, E

    Purpose: To provide an update on the recent knowledge about the molecular mechanisms of thermal radiosensitization and its possible relevance to thermoradiotherapy. Summary: Hyperthermia is probably the most potent cellular radiosensitizer known to date. Heat interacts with radiation and potentiates

  15. ADPRT inhibitors and hyperthermia as radiosensitizers

    International Nuclear Information System (INIS)

    Jonsson, G.G.

    1985-01-01

    Hyperthermia given in combination with gamma radiation has given considerable improvement in the therapeutic results for treatment of malignant tumors. The mechanism behind the hyperthermia effect is probably operative at the tissue level as well as at the molecular level. The metabolism of NAD + in relation to the activity of the chromosomal enzyme ADP-ribosyl transferase (ADPRT) has been studied as a possible molecular mechanism for this effect. The ADPRT activity was measured after radiosensitization with both hyperthermia and nicotinamide, which is a potent inhibitor of ADPRT. The results indicate that hyperthermia can improve the effect of radiotherapy by reducing the supply of NAD + , which is a co-substrate for ADPRT, while nicotinamide functions as a radiosensitizing agent by direct inhibition of the enzyme. The hypothesis is discussed in the thesis where inhibition of ADPRT might increase the radiosensitivity because the radiation-induced DNA damage can not be repaired with normal efficiency. The function of nicotinamide as a radiosensitizer was verified by studies on C3H mice with transplanted spontaneous mammary tumors. Because nicotinamide is not toxic, it seems quite attractive to test this vitamin as a radiosensitizing agent against human tumors. (251 refs.) (author)

  16. The effect of X-irradiation on vitamin E deficient rat liver mitochondrial ATPase and cytochrome c oxidase

    International Nuclear Information System (INIS)

    Korkut, S.

    1978-01-01

    Male albino rats were fed for 3 weeks on standard diets or on diets either deficient in or supplemented by vitamin E, whole-body X-irradiated and then immediately decapitated. Liver mitochondrial ATPase activity was stimulated and cytochrome c oxidase inhibited in the irradiated vitamin E deficient group. These activities were not influenced by irradiation in the rats fed on vitamin E supplemented and standard diets. The live mitochondrial vitamin E level was decreased in rats fed on the deficient diet. No differences in liver mitochondrial vitamin E levels were observed after X-irradiation of rats fed on any of the diets. The results suggest that the liver mitochondrial inner-membrane structure may be altered by a diet deficient in vitamin E. (U.K.)

  17. Effect of thoracic x-irradiation on glucose-6-phosphate dehydrogenase activity of the pectoral muscle of guinea pig

    International Nuclear Information System (INIS)

    Bhatavdekar, J.M.; Shah, V.C.

    1981-01-01

    The histochemical distribution of glucose-6-phosphate dehydrogenase (G6PD) was observed in the major pectoral muscle of a guinea pig that had received 240 R thoracic X-irradiation. The irradiation effects were studied at 24, 48 and 72 hrs after X-irradiation. Type I fibres of the pectoral muscle were deeply stained showing high activity whereas type II fibres demonstrated minimum enzyme activity. The intermediate fibres had medium levels of G6PD activity. Type II fibres showed more staining at 24 and 48 hrs as compared with control muscle. However, at 72 hrs all three fibre types showed a marked inhibition of G6PD activity. The significance of these changes suggests that muscle G6PD metabolism generally altered after irradiation, but the specific nature of these changes and their causes still remain unclear. (author)

  18. Effects of caffeine on protein phosphorylation and cell cycle progression in X-irradiated two-cell mouse embryos

    International Nuclear Information System (INIS)

    Jung, Th.; Streffer, C.

    1992-01-01

    To understand the mechanism of the caffeine-induced uncoupling of mitosis and the cellular reactions to DNA-damaging agents, the authors studied the effects of caffeine treatment on cell cycle progression and protein phosphorylation in two-cell mouse embryos after X-irradiation. Caffeine alone had no effect on timing of and changes in phosphorylation associated with the embryonic cell cycle. In combination with X-rays, caffeine was able to override the radiation induced G 2 block and restored normal timing of these phosphorylation changes after X-irradiation. New additional changes in protein phosphorylation appeared after the combined treatment. Isobutyl-methylxanthine (IBMX), a substance chemically related to caffeine but a more specific inhibitor of the phosphodiesterase that breaks down cyclic AMP, reduced radiation induced G 2 block from 4 to 5 h to about 1 h and restored the cell cycle associated changes in protein phosphorylation. (author)

  19. Effect of X-irradiation and vitamin C on DNA degradation and endogenous DNAase in embryonic chick lens cells

    International Nuclear Information System (INIS)

    Trevithick, J.R.; Chaudun, E.; Muel, A.S.; Courtois, Y.; Counis, M.F.

    1987-01-01

    The lens is an organ in which epithelial cells become elongated fibers. During this process, nuclei are transformed and the DNA is degraded. In previous studies, we described an autodigestion of the chromatin in isolated fiber nuclei but not in epithelial nuclei, but the level of DNAase activity was found to be identical in both epithelial and fiber nuclei of lenses at 11 days of development. In this study, we have investigated the possibility that x-irradiation might stimulate the nuclear endogenous activity responsible for chromatin breakdown or epithelial cells to a level comparable to that observed in fiber cells. We have observed that x-irradiation does not increase the nuclear epithelial DNAase activity. Conversely, vitamin C, suspected to prevent cataract formation by protecting DNA against free radical formation, has a damaging effect on the DNA of the lens of chick embryo in vitro. (author)

  20. Effects of caffeine on protein phosphorylation and cell cycle progression in X-irradiated two-cell mouse embryos

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Th. (AFRC Institute of Animal Physiology and Genetics Research, Babraham (United Kingdom)); Streffer, C. (Essen Univ (Germany). Inst. fuer Medizinische Strahlenbiolgie)

    1992-08-01

    To understand the mechanism of the caffeine-induced uncoupling of mitosis and the cellular reactions to DNA-damaging agents, the authors studied the effects of caffeine treatment on cell cycle progression and protein phosphorylation in two-cell mouse embryos after X-irradiation. Caffeine alone had no effect on timing of and changes in phosphorylation associated with the embryonic cell cycle. In combination with X-rays, caffeine was able to override the radiation induced G[sub 2] block and restored normal timing of these phosphorylation changes after X-irradiation. New additional changes in protein phosphorylation appeared after the combined treatment. Isobutyl-methylxanthine (IBMX), a substance chemically related to caffeine but a more specific inhibitor of the phosphodiesterase that breaks down cyclic AMP, reduced radiation induced G[sub 2] block from 4 to 5 h to about 1 h and restored the cell cycle associated changes in protein phosphorylation. (author).

  1. Migration inhibition of immune mouse spleen cells by serum from x-irradiated tumor-bearing mice

    International Nuclear Information System (INIS)

    Moroson, H.

    1978-01-01

    Tumor-specific antigens of the chemically induced MC 429 mouse fibrosarcoma were detected in a 3 M KCl extract of tumor by the inhibition of migration of specifically immune spleen cells. Using this assay with serum from tumor-bearing mice no tumor antigen was detected in serum of mice bearing small tumors, unless the tumor was exposed to local x irradiation (3000 R) 1 day prior to collection of serum. It was concluded that local x irradiation of tumor caused increased concentration of tumor antigen in the serum. When the tumor was allowed to grow extremely large, with necrosis, then host serum did cause migration inhibition of both nonimmune and immune spleen cells. This migration-inhibition effect was not associated with tumor antigen, but with a nonspecific serum factor

  2. Application of bio-marker to study on tumor radiosensitivity

    International Nuclear Information System (INIS)

    Guo Wanfeng; Ding Guirong; Han Liangfu

    2001-01-01

    To definite tumor radiosensitivity is important for applying the schedules of individualization of patient radiotherapy. Many laboratories were carrying on the research which predict the tumor radiosensitivity with one bio-marker or/and multi-bio-marker in various levels. At present has not witnessed the specific bio-marker, but it provides an excellent model for predicting tumor radiosensitivity

  3. Morphoquantitative changes in central and intermediate sections of visual analyzer after whole-body x-irradiation

    International Nuclear Information System (INIS)

    Logvinov, S.V.; Ryzhov, A.I.

    1989-01-01

    Morphoquantitative estimation of changes in 4 and 5 layers of visual cortex and outer geniculated bodies of the brain of guinea pigs subjected to whole-body X-irradiation with a median lethal doses shows that neurons from the visual analyzer sections under study are differently damaged. The morphogenesis of changes is connected with the original variations in the quantitative structure of a neuron-glial complex displaying and selective alterative and productive reaction of the perivascular glia

  4. Levels of glutamate, aspartate, GABA, and taurine in different regions of the cerebellum after x-irradiation-induced neuronal loss

    International Nuclear Information System (INIS)

    Rea, M.A.; McBride, W.J.; Rohde, B.H.

    1981-01-01

    The levels of glutamate (Glu), aspartate (Asp), gamma-amino-n-butyric acid (GABA), and taurine (Tau) were determined in the cortex, molecular layer, and deep nuclei of cerebella of adult rats exposed to X-irradiation at 12-15 days following birth (to prevent the acquisition of late-forming granule cells; 12-15x group) and 8-15 days following birth (to prevent the acquisition of granule and stellate cells; 8-15x group). Also, the levels of the four amino acids were measured in the crude synaptosomal fraction (P2) isolated from the whole cerebella of the control, 12-15x, and 8-15x groups. The level of Glu was significantly decreased by (1) 6-20% in the cerebellar cortex; (2) 15-20% in the molecular layer; and (3) 25-50% in the P2 fraction of the X-irradiated groups relative to control values. The content of Glu in the deep nuclei was not changed by X-irradiation treatment. Regional levels of Asp were unchanged by X-irradiation, while its level in P2 decreased by 15-30% after treatment. The levels of GABA and Tau in the molecular layer, deep nuclei, or P2 were not changed in the experimental groups. However, there was a 15% increase in the levels of GABA and Tau in the cerebellar cortex of the 8-15x group relative to control values. The data support the proposed role of glutamate as the excitatory transmitter released from the cerebellar granule cells but are inconclusive regarding a transmitter role for either Tau or GABA from cerebellar stellate cells

  5. Destruction and regeneration of seminiferous tubules after local x-irradiation of testes of the adult rats

    International Nuclear Information System (INIS)

    Kurnosova, T.R.; Rajtsina, S.S.

    1987-01-01

    It was established that the local X-irradiation (1000 R) of testes of the adult rats results in a total destruction of seminiferous tubules. The restitution of the organ structure proceeds via formation of new seminiferous tubules in which spermatogenic epithelium later develops. Rete testis and germ cells preserved in its epithelium from embryogenesis are a source of regeneration material. The results obtained favour the suggestion about the dynamic structure of mammalian testis

  6. Enhancement of the efficacy of x-irradiation by pentobarbital in a rodent brain-tumor model

    International Nuclear Information System (INIS)

    Olson, J.J.; Friedman, R.; Orr, K.; Delaney, T.; Oldfield, E.H.

    1990-01-01

    Radiation therapy is an important component of brain tumor treatment, but its efficacy is limited by its toxicity to the surrounding normal tissue. Pentobarbital acts as a cerebral radioprotectant, but the selectivity of its protection for the central nervous system has not been demonstrated. To determine if pentobarbital also protects tumor against ionizing radiation, five groups of Fischer 344 rats were observed after exposure to varying combinations of the presence or absence of implanted tumor, pentobarbital, and radiation treatment. The first three groups underwent cerebral implantations of a suspension of 9L gliosarcoma cells. Group 1 was left untreated and served as tumor-bearing controls. Group 2 received 30 Gy of whole-brain x-irradiation without anesthesia 8 days after tumor implantation. Group 3 received the same radiation treatment 15 minutes after pretreatment with 60 mg/kg of pentobarbital intraperitoneally. Groups 4 and 5 served as radiation controls, receiving 30 Gy of x-irradiation while awake and 30 Gy of x-irradiation after pentobarbital administration, respectively. Survival was calculated from the death of the last tumor-bearing rat. The mean survival time in tumor-bearing control rats was 20.8 +/- 2.6 days (+/- standard deviation). X-irradiation alone significantly enhanced the period of survival in rats implanted with the 9L tumor (29.7 +/- 5.6 days, p less than 0.03). Further significant prolongation of survival was seen with the addition of pentobarbital to the treatment regimen (39.9 +/- 13.5 days, p less than 0.01). Nontumor-bearing rats irradiated while awake (Group 4) survived 30.9 +/- 2.3 days. All of their pentobarbital-anesthetized counterparts in Group 5 survived. If pentobarbital had offered radioprotection to the tumor, then Group 3 would have had a shorter survival period than Group 2

  7. Interplay of thymus and bone marrow regeneration in x-irradiated mice

    International Nuclear Information System (INIS)

    Hiesche, K.-D.

    1975-01-01

    aim of the prepresent investigation was to study the modifying effects of bone marrow cells on regeneration, after X-irradiation, of thymus and bone marrow cell populations. Data are presented which indicate that the cellular composition of the thymus and, in particular, the frequency of the stem cells in the organ at the time of radiation exposure determines thymic regeneration for about two weeks after irradiation. After this period, regeneration depends on new precursors from the bone marrow which have previously seeded the thymus. In contrast to the thymus, cellular restoration of the bone marrow is already initially dependent on the number of protected or transplanted marrow cells. Two phases in the recovery of thymic PHA-reactivity after irradiation were observed: one initial phase which is independent on the number of the available bone marrow cells, and a subsequent phase during which PHA-reactivity is slightly increased in mice irradiated with partly protected bone marrow in comparison to in total body irradiated animals. During the entire observation period, PHA-reactivity remains at a low level not exeeding 50 % of that in untreated mice. In contrast the thymus is fully repopulated with regard to the number of nonreactive cells. Alternative pathways of thymocyte development within the thymus are discussed. Bone marrow X cells were shown to be as sensitive to in vitro treatment with a specific H-2 antiserum as were lymphocytes from normal bone marrow. This finding was teken to indicate that the X cells represent a particular lymphoid cell type. A xenogeneic rabbit-anti-mouse embryo antiserum was more toxic to pre-irradiated bone marrow, with high proportion of X cells, than to bone marrow from untreated mice, using in vitro cytotoxicity test. A possible embryonic character of the X cells is discussed. (author)

  8. Shielding of the abdominal region during X-irradiation: Effect on haemopoietic stem cells

    International Nuclear Information System (INIS)

    Vavrova, J.; Petyrek, P.

    1984-01-01

    The shielding of the abdominal region during X-irradiation is important for two reasons: 1) it prevents the development of the gastrointestinal syndrome following higher radiation doses; 2) it prevents the development of the lethal form of the bone marrow syndrome by shielding a portion of the spinal column bone marrow and the spleen. The dose reduction factor in partial irradiated mice compared to whole-body irradiated mice was 2.6. 15 mins after irradiation with the dose of 10 Gy, the number of spleen colony-forming cells (CFU-S) decreased in the femoral bone marrow of both the group receiving whole-body irradiation and the group having the abdominal region shielded. This decrease persisted in both groups for five hours after irradiation. 48 hours after whole-body irradiation, the number of CFU-S in the femoral bone marrow of the unshielded animals decreased almost to zero values. In shielded group, a statistically significant increase in the number of CFU-S in the femur was observed at 48 hours. At 120 hours, the number of CFU-S in so irradiated mice was at the level of the unirradiated group. In the spleen a great decrease in the number of CFU-S was caused by whole-body irradiation of mice as early as 15 mins after irradiation and the low-levels were recorded until the death of animals. In the shielded group, a statistically signifjcant decrease in the number of CFU-S was observed 15 mins after irradiation, which may have been due to the abscopal effect of irradiation. After a transient recovery 2 hours after irradiation, a significant decrease in the number of CFU-S in the spleens was observed in the subsequent interval from five to 120 hours after irradiation. (author)

  9. Late vascular effects of whole brain X-irradiation in the mouse

    Energy Technology Data Exchange (ETDEWEB)

    Yoshii, Y [Tsukuba Univ., Sakma, Ibaraki (Japan). Inst. of Clinical Medicine; Phillips, T L [California Univ., San Francisco (USA). Dept. of Radiation Oncology

    1982-01-01

    The whole brains of mice were irradiated with 250kVp X-rays at 120 rads min/sup -1/ (1.6 mm Cu HVL, TSD 50 cm), and a histological study was carried out. The dose range of X-irradiation was from 1,300 to 2,500 rads, i.e., 1,300, 1,500, 1,750, 2,000, and 2,500 rads. Eighty-six mice were used for histological examination. For microscopic examination, the mice were killed at regular postirradiation intervals between 15 and 20, 31 and 40, 41 and 50, 51 and 60, 61 and 70, 71 and 80, 81 and 90, 139 and 177 weeks. The brains were removed immediately thereafter, fixed in Bouin's solution, and embedded in paraffin. A histological examination was performed by a morphometric estimation of vascular lesions, in which the degree of the damage to the arterial system was scored in whole serial brain section. Necrosis (encephalomalacia), atrophy, cell infiltration, and telangiectactic vascular change of the brain, caused as a result of the fibrinoid necrosis of the large arteries, were observed. Dose-dependent incidence of the fibrinoid necrosis increased between 41 and 87 weeks after irradiation. Mean score of fibrinoid necrosis increased dose dependently approximately 60 weeks after irradiation. It is suggested that scores of large vessel damage do relate to dose at 41 to 87 weeks, and can be used to quantify the vessel injury, and that fibrinoid necrosis of the large vessels may relate to the incidence of radionecrosis.

  10. Late vascular effects of whole brain X-irradiation in the mouse

    International Nuclear Information System (INIS)

    Yoshii, Y.; Phillips, T.L.

    1982-01-01

    The whole brains of mice were irradiated with 250kVp X-rays at 120 rads min -1 (1.6 mm Cu HVL, TSD 50 cm), and a histological study was carried out. The dose range of X-irradiation was from 1,300 to 2,500 rads, i.e., 1,300, 1,500, 1,750, 2,000, and 2,500 rads. Eighty-six mice were used for histological examination. For microscopic examination, the mice were killed at regular postirradiation intervals between 15 and 20, 31 and 40, 41 and 50, 51 and 60, 61 and 70, 71 and 80, 81 and 90, 139 and 177 weeks. The brains were removed immediately thereafter, fixed in Bouin's solution, and embedded in paraffin. A histological examination was performed by a morphometric estimation of vascular lesions, in which the degree of the damage to the arterial system was scored in whole serial brain section. Necrosis (encephalomalacia), atrophy, cell infiltration, and telangiectactic vascular change of the brain, caused as a result of the fibrinoid necrosis of the large arteries, were observed. Dose-dependent incidence of the fibrinoid necrosis increased between 41 and 87 weeks after irradiation. Mean score of fibrinoid necrosis increased dose dependently approximately 60 weeks after irradiation. It is suggested that scores of large vessel damage do relate to dose at 41 to 87 weeks, and can be used to quantify the vessel injury, and that fibrinoid necrosis of the large vessels may relate to the incidence of radionecrosis. (Author)

  11. Mechanism of derivation of radioresistance in HeLa cell population after repeated x-irradiation

    International Nuclear Information System (INIS)

    Kubo, Kihei; Koiwai, Soichiro; Morita, Kazuo

    1982-01-01

    The Radioresistant strain (X-8-5) was obtained from HeLa-SC population X-irradiated repeatedly for five times with 800 rad. The mean lethal dose (D 0 ) was 196 rad for X-8-5 cells, while it was 166 rad for control HeLa-SC cells. The fraction of cells containing an unusually long acrocentric chromosome (LA 2) exclusively increased with increasing number of irradiation of HeLa-SC population. A clonal strain with LA 2 marker was isolated from X-8-5 population and named RC-355. Since the RC-355 cells were more resistant (D 0 = 220 rad)than parental X-8-5 cells (D 0 = 196 rad), it was suggested that the cells with LA 2 were responsible for the radioresistance of X-8-5 population. The RC-355 cells were further subjected to the analysis of Q-banded karyotypes and it was observed that 18 types of specific markers (rm 1-17 and LA 2) were included in RC-355 cells in addition to 12 types of markers observed in most of HeLa-SC cells. Since the analysis of Q-banded karyotypes of RC-355 cells showed that RC-355 specific markers were not produced by radiation-induced rearrangements of HeLa-SC chromosomes, because twelve kinds of HeLa-SC markers were presented in RC-355 cells without any change, it was concluded that a small number of cells with LA 2 marker were originally presented in the control population and the relative fraction of them occupied increased after irradiation. (author)

  12. Interplay of thymus and bone marrow regeneration in x-irradiated mice

    Energy Technology Data Exchange (ETDEWEB)

    Hiesche, K D

    1975-01-01

    The aim of the present investigation was to study the modifying effects of bone marrow cells on regeneration, after X-irradiation, of thymus and bone marrow cell populations. Data are presented which indicate that the cellular composition of the thymus and, in particular, the frequency of the stem cells in the organ at the time of radiation exposure determines thymic regeneration for about two weeks after irradiation. After this period, regeneration depends on new precursors from the bone marrow which have previously seeded the thymus. In contrast to the thymus, cellular restoration of the bone marrow is already initially dependent on the number of protected or transplanted marrow cells. Two phases in the recovery of thymic PHA-reactivity after irradiation were observed: one initial phase which is independent on the number of the available bone marrow cells, and a subsequent phase during which PHA-reactivity is slightly increased in mice irradiated with partly protected bone marrow in comparison to in total body irradiated animals. During the entire observation period, PHA-reactivity remains at a low level not exeeding 50 % of that in untreated mice. In contrast the thymus is fully repopulated with regard to the number of nonreactive cells. Alternative pathways of thymocyte development within the thymus are discussed. Bone marrow X cells were shown to be as sensitive to in vitro treatment with a specific H-2 antiserum as were lymphocytes from normal bone marrow. This finding was teken to indicate that the X cells represent a particular lymphoid cell type. A xenogeneic rabbit-anti-mouse embryo antiserum was more toxic to pre-irradiated bone marrow, with high proportion of X cells, than to bone marrow from untreated mice, using in vitro cytotoxicity test. A possible embryonic character of the X cells is discussed.

  13. Age-dependent radiosensitivity of mouse oocytes

    International Nuclear Information System (INIS)

    Koehler, C.

    1976-01-01

    It has been shown that there are three distinct phases of radiosensitivity in oocytes of prepubertal mice: a period of rapidly increasing sensitivity between 0 and 4 days of age; a period of consistent, high sensitivity between 5 and 18 days of age; and a period of decreasing sensitivity from 19 to at least 21 days of age. Two distinct phases have been demonstrated for the rate of population decline of the oocytes of primary follicles: an initial period of rapid loss from 0 to 4 days of age; and a period of much slower loss from 5 through 23 days of age. Correlations have been drawn between the first two phases of radiosensitivity and morphological changes in the oocyte, and between the third phase of radiosensitivity and endocrinological changes in the maturing animal. The reaction of oocytes to radiation has been separated into two categories: immediate death (within 24 hours); and delayed death (over the entire lifespan of the animal)

  14. Radiosensitizers in cervical cancer. Cisplatin and beyond

    International Nuclear Information System (INIS)

    Candelaria, Myrna; Garcia-Arias, Alicia; Cetina, Lucely; Dueñas-Gonzalez, Alfonso

    2006-01-01

    Cervical cancer continues to be a significant health burden worldwide. Globally, the majority of cancers are locally advanced at diagnosis; hence, radiation remains the most frequently used therapeutical modality. Currently, the value of adding cisplatin or cisplatin-based chemotherapy to radiation for treatment of locally advanced cervical cancer is strongly supported by randomized studies and meta-analyses. Nevertheless, despite these significant achievements, therapeutic results are far from optimal; thus, novel therapies need to be assayed. A strategy currently being investigated is the use of newer radiosensitizers alone or in combination with platinum compounds. In the present work, we present preclinical information on known and newer cytotoxic agents as radiosensitizers on cervical cancer models, as well as the clinical information emanating from early phase trials that incorporate them to the cervical cancer management. In addition, we present the perspectives on the combined approach of radiation therapy and molecular target-based drugs with proven radiosensitizing capacity

  15. 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)

  16. 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)

  17. Effect of whole body X-irradiation on the NP-SH level of blood in rabbits

    International Nuclear Information System (INIS)

    Suh, Soo Jhi; Woo, Won Hyung

    1972-01-01

    In hope to elucidate possible changes in blood NP-SH levels when X-irradiation is made in single or fractionate dose, a whole body X-irradiation was done to rabbits either in single dose of 900 r or in fractionated dose of 300 r per day for three days. The NP-SH was measured at 1, 3, 5, 24 and 48 post-irradiation hours, and the results were compared with the normal value of the blood NP-SH. The results obtained are as follows: 1. The normal value of blood NP-SH in the rabbit was 2.11 ± 0.40 μmol/ml. 2. In the single X-irradiation group, the blood NP-SH decreased most prominently at five hours after-irradiation, and a tendency of recovery to the normal level was observed thereafter. 3. In the fractionated group, the blood NP-SH levels were higher, than in the single irradiation group throughout the experiment, and the levels were also higher than the normal in general

  18. A comparison of effects between accelerated heavy ion irradiation and X-irradiation on the development of rat cerebellum

    International Nuclear Information System (INIS)

    Inouye, Minoru; Hayasaka, Shizu; Murata, Yoshiharu; Takahashi, Sentaro; Kubota, Yoshihisa

    1999-01-01

    The purpose of this experiment is to compare the effects of 290 MeV/u carbon-ion irradiation and X-irradiation on the development of rat cerebellum. Pregnant rats were exposed to carbon-ion beams at a single dose of 1.5 Gy on day 19.0 of gestation. Other groups of pregnant rats were exposed to X-rays on day 19.0 at single doses of 1.5, 2.0 and 2.5 Gy. Their fetuses were removed 8 hr after exposure, and an acute effect examined microscopically for cell death in the external granular layer of the cerebellum. Other dams were allowed to give birth and rear their litters. The offspring were sacrificed at 6 weeks of age, and their cerebella were examined for foliar malformation. The results showed that the effect of 1.5 Gy carbon-ion irradiation on the development of cerebellum was stronger than that of 1.5 Gy X-irradiation and similar to 2.0-2.5 Gy X-irradiation. (author)

  19. Radio-sensitivity of the cells from amyotrophic lateral sclerosis model mice transfected with human mutant SOD1

    International Nuclear Information System (INIS)

    Wate, Reika; Ito, Hidefumi; Kusaka, Hirofumi; Takahashi, Sentaro; Kubota, Yoshihisa; Suetomi, Katsutoshi; Sato, Hiroshi; Okayasu, Ryuichi

    2005-01-01

    In order to clarify the possible involvement of oxidative damage induced by ionizing radiation in the onset and/or progression of familial amyotrophic lateral sclerosis (ALS), we studied radio-sensitivity in primary cells derived from ALS model mice expressing human mutant Cu/Zn superoxide dismutase (SOD1). The primary mouse cells expressed both mouse and the mutant human SOD1. The cell survival of the transgenic mice (with mutant SOD1), determined by counting cell numbers at a scheduled time after X-irradiation, is very similar to that of cells from wild type animals. The induction and repair of DNA damage in the transgenic cells, measured by single cell gel electrophoresis and pulsed field gel electrophoresis, are also similar to those of wild type cells. These results indicate that the human mutant SOD1 gene does not seem to contribute to the alteration of radio-sensitivity, at least in the fibroblastic cells used here. Although it is necessary to consider the difference in cell types between fibroblastic and neuronal cells, the present results may suggest that ionizing radiation is not primarily responsible for the onset of familial ALS with the SOD1 mutation, and that the excess risks are probably not a concern for radiation diagnosis and therapy in familial ALS patients. (author)

  20. The influence of gender- and age-related differences in the radiosensitivity of hematopoietic progenitor cells detected in steady-state human peripheral blood

    International Nuclear Information System (INIS)

    Kato, Kengo; Kashiwakura, Ikuo; Kuwabara, Mikinori

    2011-01-01

    To investigate the importance of gender and aging on the individual radiosensitivity of lineage-committed myeloid hematopoietic stem/progenitor cells (HSPCs) detected in mononuclear cells (MNCs) of steady-state human peripheral blood (PB), the clonogenic survival of HPCs, including colony-forming unit-granulocyte macrophage; burst-forming unit-erythroid; colony-forming unit-granulocyte-erythroid-macrophage-megakaryocyte cells derived from MNCs exposed to 0.5 Gy and 2 Gy X-irradiation were estimated. MNCs were prepared from the buffy-coats of 59 healthy individual blood donors. The results showed that large individual differences exist in the number of HSPCs, as well as in the surviving fraction of cells. Furthermore, the number of progenitor cells strongly correlated with their surviving fraction, suggesting that the radiosensitivity of hematopoietic progenitor cells decreases with the number of cells in the 10 5 cells population. A statistically significant negative correlation was observed between the surviving fraction observed at a dose of 0.5 Gy and the age of an individual, however, none of these correlations were observed after 2 Gy irradiation. No statistically significant difference was observed in individual radiosensitivity between males and females at either radiation dose. The present results indicated a correlation between the individual responsiveness of HSPCs to ionizing irradiation, especially to low dose irradiation, and aging. (author)

  1. Genetic control of the radiosensitivity of lymphoid cells for antibody-forming ability in CXS series of recombinant inbred mouse strains

    International Nuclear Information System (INIS)

    Okumoto, M.; Mori, N.; Nishikawa, R.; Imai, S.; Hilgers, J.; Takamori, Y.; Yagasaki, O.

    1992-01-01

    Incidence of radiation-induced lymphomas differs remarkably among various mouse strains. BALB/cHeA (C) mice are highly susceptible to radiation induction of lymphomas, while STS/A (S) mice are resistant. Thus, the induction of the disease is controlled by some genetic factors. To examine an involvement of radiosensitivity of lymphoid cells in lymphomagenesis, we have compared genetic control of the radiosensitivity for antibody-forming ability with that of lymphoma development in BALB/cHeA, STS/A, (CXS)F 1 hybrids and CXS series of recombinant inbred strains. Decrease of number of splenic plaque-forming cell (PFC) in Jerne's method by 3 Gy of X-irradiation for BALB/cHeA mice was larger than that for STS/A mice by more than one order of magnitude. (CXS)F 1 hybrid mice showed small number of decrease of PFC similar to STS/A mice suggesting that phenotype of radioresistance was dominant over sensitivity. The best concordance between genetic markers and radiosensitivities of antibody-forming ability in recombinant inbred strains was observed in a region containing Igh locus on chromosome 12. The results show that one locus controlling the radioresistance of lymphoid cells for antibody-forming ability might exist in the region containing Igh locus, and that this region clearly differ from a region with Ifa locus on chromosome 4 which regulate the susceptibility to radiation-induced lymphomagenesis. (author)

  2. Chromosome aberrations in human lymphocytes for investigation of individual radiosensitivity

    International Nuclear Information System (INIS)

    Zitzelsberger, H.; Bauchinger, M.

    2000-01-01

    Stable translocations and insertions which are not selected against during cell proliferation can be reliably scored by use of fluorescence in situ hybridisation (FISH) which allows painting of selected chromosomes along their entire length. This temporal persistence makes them particulary valuable for quantifying post human radiation exposures ('biodosimetry'). A disadvantage of this approach is that for routine use only a partial genome analysis can be performed which is mostly based on triple combinations of DNA probes for particular chromosomes. Translocation frequencies from partial genome analysis are often scaled-up to equal the full genome. Basic assumptions for such scaling are, that double strand breaks leading to translocations must be distributed randomly throughout the genome and no preferential interaction between particular pairs of chromosomes occurs. Thus, the probability of a particular chromosome being involved in an exchange is proportional to its DNA content. However, this is not always supported by experimental findings and may thus indicate a differential radiosensitivity of particular chromosomes. Translocation measurements in peripheral blood of different healthy donors irradiated in vitro with the same dose revealed also some evidence for the existence of interindividual differences in radiosensitivity. Similar findings have been already demonstrated after therapeutic irradiation of tumour patients. Consequences thereof may result for long-term retrospective biodosimetry. In order to provide reliable estimates of an individual's exposure to ionising radiation, the extent, distribution and dose-dependence of the observed variability has to be carefully examined in larger groups of persons and larger sets of calibration data. (orig.) [de

  3. LET effects on normal and radiosensitive cell lines

    International Nuclear Information System (INIS)

    Geard, C.R.; Travisano, M.

    1986-01-01

    Charged particles in the track segment mode were produced by the RARAF Van de Graaff accelerator and used to irradiate two CHO cell lines, a radiosensitive hypermutable line EM9 and its normal parent AA8. Asynchronous cells were irradiated attached to 6 micrometer thick Mylar with protons, deuterons and helium-3 particles at LETs ranging from 10 to 150 keV per micrometer. A 50 kVp x-ray tube integrated into the track segment facility provided a low LET comparison. Following irradiation cells were monitored for clonogenicity, and in a separate series of experiments frequencies of sister chromatid exchanges. Up to 9 experiments were carried out at each LET, with a total of 8 radiations of different LETs being compared. The optimally effective LET for cell survival was between 80 and 120 keV per micrometer, with the 150 keV per micrometer particles indicating energy wastage. The differential between the normal and radiosensitive cell lines was maintained at all LETs

  4. On the Path to Seeking Novel Radiosensitizers

    International Nuclear Information System (INIS)

    Katz, David; Ito, Emma; Liu Feifei

    2009-01-01

    Radiation therapy is a highly effective cancer treatment modality, and extensive investigations have been undertaken over the years to augment its efficacy in the clinic. This review summarizes the current understanding of the biologic bases underpinning many of the clinically used radiosensitizers. In addition, this review illustrates how the advent of innovative, high-throughput technologies with integration of different disciplines could be harnessed for an expeditious discovery process for novel radiosensitizers, providing an exciting future for such pursuits in radiation biology and oncology

  5. Enhanced spermatogonial stem cell killing and reduced translocation yield from X-irradiated 101/H mice

    Energy Technology Data Exchange (ETDEWEB)

    Cattanach, B M; Kirk, M J

    1987-01-01

    The spermatogonial stem cells of 101/H mice have been found to be more sensitive to killing by acute X-ray doses than those of the 'standard' C3H/HeH x 101/H F/sub 1/ hybrid. Duration of the sterile period was longer throughout the 0.5-8.0-Gy dose range tested and 'recovered' testis weights, taken after recovery of fertility, were more severely reduced. The shapes of the sterile period dose-response curves were similar, but with the 101/H mice the plateau occurred at 3-5 Gy, rather than at 6 Gy. An equivalent observation was made with the testis weight data. The translocation dose-response curve was bell-shaped, as previously found with the hybrid, but yields were lower at all but the lowest doses. Notably, peak yields occurred at 3-5 Gy, rather than at 6 Gy. The altered stem cell killing and genetic responses may be explained either by a higher proportion of radiosensitive cells in the heterogeneous stem cell population or by a higher ratio of cell killing to recoverable chromosome damage which might imply a reduced repair capacity. (Auth.). 43 refs.; 5 figs.; 5 tabs.

  6. Low-level x-irradiation of the brain during development morphological, physiological, and behavioral consequences. Final report, September 1, 1976--August 31, 1977

    International Nuclear Information System (INIS)

    Altman, J.

    1977-01-01

    Morphological research was continued in the following areas: glial recovery patterns in the rat corpus callosum after x-irradiation during infancy; the prenatal development of the deep nuclei and cortex of the cerebellum; the prenatal development of the inferior olive, pontine gray and the precerebellar reticular nuclei; and the postnatal development of the olfactory bulb. In these studies autoradiography and x-irradiation were among the experimental techniques utilized. The behavioral studies, all of which are still in progress, are concerned with the effects of different schedules of postnatal x-irradiation of the cerebellum, and the effects of x-irradiation of the olfactory bulb. A list is included of 14 publications that report results in detail

  7. Preferential radiosensitization of G1 checkpoint--deficient cells by methylxanthines

    International Nuclear Information System (INIS)

    Russell, Kenneth J.; Wiens, Linda W.; Demers, G. William; Galloway, Denise A.; Le, Tiep; Rice, Glenn C.; Bianco, James A.; Singer, Jack W.; Groudine, Mark

    1996-01-01

    Purpose: To develop a checkpoint-based strategy for preferential radiosensitization of human tumors with deficient and/or mutant p53. Methods and Materials: A549 human lung adenocarcinoma cell lines differing in their expression of the p53 tumor suppressor gene were produced by transduction with the E6 oncogene from human papilloma virus type 16. The cells expressing E6 (E6+) lack a G1 arrest in response to ionizing radiation, are deficient in p53 and p21 expression, and exhibit a fivefold greater clonogenic survival following 10 Gy radiation. Results: Postirradiation incubation with millimolar concentrations of the methylxanthine pentoxifylline (PTX) results in preferential radiosensitization of the E6+ cells compared to the LXSN+ vector transduced controls. There is a threefold sensitization of the LXSN+ cells and a 15-fold sensitization of the E6+ cells, which results in equal clonogenic survival of the two lines. Flow cytometry reveals PTX abrogation of the radiation induced G2 arrest for both cell lines. PTX also prolongs G1 transit for both cell lines. Preliminary results are presented using a novel methylxanthine, lisofylline (LSF), which has similar cell cycle effects on G1 and G2 and achieves differential radiosensitization at micromolar concentrations that are sustainable in humans. Conclusions: This checkpoint-based strategy is a promising approach for achieving preferential radiosensitization of p53- tumors relative to p53+ normal tissues

  8. Different radiosensitivities of mast-cell precursors in the bone marrow and skin of mice

    International Nuclear Information System (INIS)

    Kitamura, Y.; Yokoyama, M.; Sonoda, T.; Mori, K.J.

    1983-01-01

    Although tissue mast cells are derived from the bone marrow, some descendants of bone marrow-derived precursors retain the ability to proliferate and differentiate into mast cells even after localization in the skin. The purpose of the present study was to determine the D0 values for mast-cell precursors in the bone marrow and those localized in the skin. Bone marrow cells were removed from (WB X C57BL/6)F1-+/+ mice after various doses of irradiation and injected into the skin of the congenic W/Wv mice which were genetically without mast cells. Radiosensitivity of mast-cell precursors in the bone marrow was evaluated by determining the proportion of the injection sites at which mast cells did not appear. For the assay of the radiosensitivity of mast-cell precursors localized in the skin, pieces of skin were removed from beige C57BL/6 (bgJ/bgJ. Chediak-Higashi syndrome) mice after various doses of irradiation and grafted onto the back of the normal C57BL/6 mice. Radiosensitivity of mast-cell precursors in the skin was evaluated by determining the decrease of beige-type mast cells which possessed giant granules. Mast-cell precursors in the bone marrow were much more radiosensitive than those localized in the skin. D0 value was about 100 rad for the former and about 800 rad for the latter

  9. Comparison of radiosensitivity between tumor and normal tissue in terms of cell population kinetics

    International Nuclear Information System (INIS)

    Sugahara, Tsutomu; Utsumi, Hiroshi

    1975-01-01

    Puck and Marcus in 1956 established the in vitro colony formation of mammalian cells and demonstrated a dose-survival curve of mammalian cells well fitted to the target theory. Since then almost all of the work on the radiosensitivity of malignant and normal cells has been based on the reproductive integrity of cells. However, in the author's laboratory, a recent work was done on the effect of ionizing radiation on the differentiative trait, using clonal cell cultures developed by Coon (1966) in chick embryonic cartilage cells. This work demonstrated clearly that the differentiative trait is more radiosensitive than is reproduction. Based on this finding a new compartment model is proposed for a cell renewal system which demonstrates the difference between normal and malignant tissue. (author)

  10. Development of Radiosensitizer using farnesyltransferase inhibitors

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Jong Seok; Choe, Yong Kyung; Han, Mi Young; Kim, Kwang Dong [Korea Research Institute of Bioscience and Biotechnology, Taejon (Korea)

    1999-03-01

    We selected some compounds that were reported to have an activity of farneyltransferase inhibitor and tested the hypothesis that they might be used to radiosensitize cells transformed by ras oncogenes. The inhibition of ras processing using some, but not all, inhibitors resulted in higher levels of cell death after {gamma}-irradiation and increased radiosensitivity in H-ras-transformed NIH3T3 cells and MCF-10A human tumor cells. They did not induce additional cell death in control cells that doe not have ras mutation. Furthermore, the treatment of inhibitors alone induced a weak G0/G1 block, whereas inhibitors in combination with {gamma}-irradiation induced an additional enrichment in the G2/M phase of the cell cycle that typically represents irradiation-induced growth arrest. At present, the underling mechanism by which the farnesylltransferase inhibitors exert radiosensitizing effect is not known. In summary, our results suggest and lead to the possibility that some of farnesylation inhibitors may prove clinically useful not only as antitumor agents, but also radiosensitizers of tumors whose growth is dependent on ras function. (author). 15 refs., 10 figs., 4 tabs.

  11. Radiosensitivity of quince seeds (Cydonia oblonga Mill.)

    International Nuclear Information System (INIS)

    Dall'Orto, F.A.C.; Ojima, M.; Hiroce, R.; Igue, T.; Ferraz, E.S.B.; Nascimento Filho, V.F. do; Menten, J.O.M.; Tulmann Neto, A.; Ando, A.

    1984-01-01

    The investigation with quince seeds (Cydonia oblonga Mill.) radiosensitivity and the mineral composition of the plants obtained for mutation breeding are related. The concentration of some macro and micronutrients in quince seedlings obtained from irradiated seeds are studied. (M.A.C.) [pt

  12. Radiosensitivity of human lymphocytes and thymocytes

    International Nuclear Information System (INIS)

    Kwan, D.K.; Norman, A.

    1977-01-01

    The in vitro survival of human peripheral blood lymphocytes and thymocytes was measured 4 days following graded doses of γ radiation. Results indicate considerable heterogeneity among lymphocyte subpopulations with respect to radiosensitivity. Total T lymphocytes were characterized by rosette formation with neuraminidase-treated sheep red blood cells (nSRBC); early T (T/sub E/) cells, by early rosettes; and B cells, by their inability to form nSRBC rosettes. Late T (T/sub L/) cells were defined as T -- T/sub E/. Survival curves of T, T/sub E/, and B cells are biphasic. The radiosensitive and radioresistant components of T, T/sub E/, and B cells all have a D 0 of about 50 and 550 rad, respectively. B cells appeared to be slightly more radiosensitive than T cells. T/sub L/ cells and thymocytes, however, appeared to be homogeneous with respect to radiosensitivity, both having D 0 values of about 135 rad. The survival of T cells in mixed T and B cell cultures resembled that of separated T cells, suggesting that ionizing radiation has no significant effect on rosette formation. It also indicates that interactions of T and B cells do not significantly affect their radiation responses

  13. Osmotic homeostasis and NKLy lymphoma cells radiosensitivity

    International Nuclear Information System (INIS)

    Tishchenko, V.V.; Magda, I.N.

    1992-01-01

    In experiments with cells of ascites NKLy lymphoma differing in ploidy and position in the cell cycle, a study was made of the radiosensitivity, osmotic homeostasis peculiarities and thermoradiation changes in potassium content. It was shown that the resistance of osmotic homeostasis of NKLy cells to thermoradiation correlated with their radioresistance

  14. Photosensitizers and radiosensitizers in dermatology and oncology

    International Nuclear Information System (INIS)

    Bruckner, V.

    1979-01-01

    Two therapeutic modalities are currently of great interest, namely photo- and radiosensitization. Whereas photosensitizers only function in combination with ultraviolet (UV) light, radiosensitizers act only in combination with ionizing radiation. Because of the small UV penetration, up to a maximum of 0,5 mm, photosensitization can take place only at the surface of the body, i.e. the skin. Photosensitizers are applied in dermatology in order to optimize and improve the UV therapy of certain diseases (mainly psoriasis, mycosis fungoides and vitiligo). Radiosensitizers lead to an increase in sensitivity of the hypoxic and therefore radioresistant parts of tumours against X- and gamma-radiation. With sufficient concentration within the tumour, they can act where the radiation can reach, even in the deeper parts of the body. They represent a modern and useful aid to radiation oncology. Because of neurotoxic effects, however, their practical use is limited. A short review of the history, mechanisms of action, application and side-effects of these photo- and radiosensitizers is presented

  15. Photosensitizers and radiosensitizers in dermatology and oncology

    Energy Technology Data Exchange (ETDEWEB)

    Bruckner, V [Stellenbosch University, Parowvallei (South Africa). Departments of Medical Physics and Radiology

    1979-09-22

    Two therapeutic modalities are currently of great interest, namely photo- and radiosensitization. Whereas photosensitizers only function in combination with ultraviolet (UV) light, radiosensitizers act only in combination with ionizing radiation. Because of the small UV penetration, up to a maximum of 0,5 mm, photosensitization can take place only at the surface of the body, i.e. the skin. Photosensitizers are applied in dermatology in order to optimize and improve the UV therapy of certain diseases (mainly psoriasis, mycosis fungoides and vitiligo). Radiosensitizers lead to an increase in sensitivity of the hypoxic and therefore radioresistant parts of tumours against X- and gamma-radiation. With sufficient concentration within the tumour, they can act where the radiation can reach, even in the deeper parts of the body. They represent a modern and useful aid to radiation oncology. Because of neurotoxic effects, however, their practical use is limited. A short review of the history, mechanisms of action, application and side-effects of these photo- and radiosensitizers is presented.

  16. Effect of x irradiation on the biochemical maturation of rat cerebellum: Metabolism of [14C]glucose and [14C]acetate

    International Nuclear Information System (INIS)

    Patel, A.J.; Balazs, R.

    1975-01-01

    The effect was studied of selective x-irradiation of the cerebellum (100 R daily in the first 10 days after birth) on the maturation of glucose metabolism and the development of metabolic compartmentation, in 10-, 16-, and 23-day-old rats by using, respectively, [2- 14 C]glucose and [1- 14 C] acetate (40 μ Ci/100 g body weight each) as precursors. At day 10 significant changes, in comparison with the unirradiated controls, were observed: aspartate and γ-aminobutyrate, respectively, contained 36 percent and 64 percent more and glutamine 42 percent less glucose-carbon combined in amino acids; the glutamine/glutamate specific radioactivity ratio (RSA) was 25 percent less, and the conversion of both glucose and acetate carbons into acid-insoluble constituents was markedly reduced. However, in the postirradiation period both the conversion of glucose carbon into amino acids, and the RSA of glutamine after the administration of [ 14 C]acetate increased in a more or less normal fashion, although certain quantitative differences were noted. It seems, therefore, that the normal progress of biochemical differentiation was only affected to a small degree by the irradiation of the cerebellum, although the treatment interfered severely with cell proliferation. (U.S.)

  17. The effect of X-irradiation on membrane lipids of lymphosarcoma cells in vivo and in vitro

    NARCIS (Netherlands)

    Fonck, K; Scherphof, GL; Konings, AWT

    1982-01-01

    Phospholipids of the membranes of spleen lymphosarcoma cells were radioactively labelled with the radioresistant fatty acid palmitic acid (16:0) and the radiosensitive fatty acid arachidonic acid (20:4). The effect of irradiation on the specific radioactivity of the phospholipids was studied. For

  18. X irradiation combined with TNF alpha-related apoptosis-inducing ligand (TRAIL) reduces hypoxic regions of human gastric adenocarcinoma xenografts in SCID mice

    International Nuclear Information System (INIS)

    Takahashi, Momoko; Yasui, Hironobu; Ogura, Aki; Asanuma, Taketoshi; Inanami, Osamu; Kubota, Nobuo; Tsujitani, Michihiko; Kuwabara, Mikinori

    2008-01-01

    Our previous study showed that X irradiation induced the expression of death receptor DR5 on the cell surface in tumor cell lines under not only normoxia but also hypoxia. X irradiation combined with TNF α-related apoptosis-inducing ligand (TRAIL), which is the ligand of DR5, induced apoptosis in vitro (Takahashi et al., (2007) Journal of Radiation Research, 48: 461-468). In this report, we examined the in vivo antitumor efficacy of X irradiation combined with TRAIL treatment in tumor xenograft models derived from human gastric adenocarcinoma MKN45 and MKN28 cells in severe combined immunodeficiency (SCID) mice. X irradiation combined with TRAIL synergistically suppressed the tumor growth rates in the xenograft models derived from MKN45 and MKN28 cells, which have wild type Tp53 and mutated Tp53, respectively, indicating that the antitumor effects occurred in a Tp53-independent manner. Histological analysis showed that the combination of X irradiation and TRAIL induced caspase-3-dependent apoptotic cell death. Moreover, the immunohistochemical detection of hypoxic regions using the hypoxic marker pimonidazole revealed that caspase-3-dependent apoptosis occurred in the hypoxic regions in the tumors. These results indicated that X irradiation combined with TRAIL may be a useful treatment to reduce tumor growth in not only normoxic but also hypoxic regions. (author)

  19. Increased radiosensitivity of a subpopulation ot T-lymphocyte progenitors from patients with Fanconi's anemia

    International Nuclear Information System (INIS)

    Knox, S.J.; Wilson, F.D.; Greenberg, B.R.; Shifrine, M.; Rosenblatt, L.S.; Reeves, J.D.; Misra, H.

    1981-01-01

    In vitro radiation survival of peripheral blood T lymphocytes was studied in 15 clinically normal adults and 4 patients with Fanconi's anemia. Tritiated thymidine incorporation in a whole blood lymphocyte stimulation test (LST) and a newly developed whole blood T-lymphocyte colony assay were used to measure lymphocyte blastogenesis and colony formation in response to phytohemagglutinin (PHA) or concanavalin-A (Con-A) stimulation. Lymphocyte colony formation was found to be consistently more sensitive than the LST for detection of low-level radiation effects using both normal cells and lymphocytes from Fanconi's anemia patients. Lymphocytes from patients with Fanconi's anemia were significantly more sensitive to in vitro x-irradiation than lymphocytes from clinically normal individuals as measured by their ability to divide when stimulated by PHA in the LST (patients, D37 . 198 R; normals, D37 . 309 R, p . 0.057) and colony formation assay (patients, D37 . 53 R; normals, D37 . 109 R, p . 0.016). No significant difference in the radiosensitivity of the Con-A response was observed between the two groups. The PHA-responsive T-lymphocyte subpopulation in Fanconi's anemia patients appears to be intrinsically defective. The nature of this defect, significance in the disease process, and relevancy of these findings to the establishment of radiation protection standards are discussed

  20. Increased radiosensitivity of a subpopulation of T-lymphocyte progenitors from patients with Fanconi's anemia

    International Nuclear Information System (INIS)

    Knox, S.J.; Wilson, F.D.; Greenberg, B.R.; Shifrine, M.; Rosenblatt, L.S.; Reeves, J.D.; Misra, H.

    1981-01-01

    In vitro radiation survival of peripheral blood T lymphocytes was studied in 15 clinically normal adults and 4 patients with Fanconi's anemia. Tritiated thymidine incorporation in a whole blood lymphocyte stimulation test (LST) and a newly developed whole blood T-lymphocyte colony assay were used to measure lymphocyte blastogenesis and colony formation in response to phytohemagglutinin (PHA) or concanavalin-A (Con-A) stimulation. Lymphocyte colony formation was found to be consistently more sensitive than the LST for detection of low-level radiation effects using both normal cells and lymphocytes from Fanconi's anemia patients. Lymphocytes from patients with Fanconi's anemia were significantly more sensitive to in vitro x irradiation than lymphocytes from clinically normal individuals as measured by their ability to divide when stimulated by PHA in the LST and colony formation assay. No significant difference in the radiosensitivity of the Con-A response was observed between the two groups. The PHA-responsive T-lymphocyte subpopulation in Fanconi's anemia patients appears to be intrinsically defective. The nature of this defect, significance in the disease process, and relevancy of these findings to the establishment of radiation protection standards are discussed

  1. Tumour-specific radiosensitizers for radiation therapy

    International Nuclear Information System (INIS)

    Denekamp, J.

    1977-01-01

    Recently Adams and coworkers at the Gray Laboratory have developed a new class of radiosensitizers which act specifically on hypoxic cells by abolishing the protection afforded by low oxygen concentrations. Since most experimental tumours contain a high proportion of oxygen-deprived cells, and most normal tissues are well oxygenated, these drugs are tumour specific radiosensitizers. Based on the hypothesis that sensitization increases with increasing electron affinity, the two nitroimidazoles, metronidazole (Flagyl) and Ro-07/0582 were identified as potent radiosensitizers with low toxicity. These drugs are effective only in the absence of oxygen, and only if the drug is present at the time of irradiation. The degree of sensitization increases with drug concentration rapidly over the range 0.1 to 1.0mg/g body weight for Ro-07-0582, and more gradually for Flagyl. Tumour studies have been performed on at least 12 different experimental tumours, using a variety of end points. Significant sensitization has been observed in every tumour studied, often corresponding to a dose reduction factor of 2.0 for high but non-toxic drug doses. Fractionated studies have also been performed on a few tumour lines. In most cases a useful therapeutic advantage was observed, although the sensitization was smaller. Ro-07-0582 used with X-rays gives a therapeutic gain comparable with that from cyclotron-produced fast neutrons. Neutrons used together with Ro-07-0582 are even more effective. In addition to the radiosensitization there is a specific cytotoxicity to hypoxic cells after prolonged exposure to Ro-07-0582. This cytotoxicity can be greatly enhanced in vitro by moderate hyperthermia. Flagyl and Ro-07-0582 have been used clinically as radiosensitizers, with promising early results. The clinical application is limited to certain dose fractionation patterns because of neurotoxicity. (author)

  2. Chromosomal radiosensitivity of prostate cancer patients

    International Nuclear Information System (INIS)

    McRobbie, M.L.; Riches, A.; Baxby, K.

    2003-01-01

    Full text: Radiosensitivity of peripheral blood lymphocytes from prostate cancer patients is being investigated using the G2 assay and the Cytokinesis Block Micronucleus(CBMN)assay. The G2 assay evaluates chromosomal damage caused by irradiating cells in the G2 phase of the cell cycle. The CBMN assay quantifies the post mitotic micronuclei, which are the expression of damage incurred during G0. An association between hypersensitivity to the chromosome damaging effects of ionising radiation and cancer predispostion has been demonstrated in a number of heritable conditions by using the aforementioned techniques. Recently, increased chromosomal radiosensitivity has been demonstrated in a significant proportion of patients with no obvious family history of malignancy. The aim of this study is to establish whether a group of prostatic carcinoma patients exists and if so whether there are any correlations between their G2 and G0 sensitivities. The study has shown there is no correlation between G2 and G0 sensitivity, confirming the general trend that individuals exhibiting chromosomal radiosensitivity are defective in only one mechanism and G2 and G0 sensitivity are largely independent. Current data indicates that there is an identifiable group of men within the prostate cancer population with increased chromosomal radiosensitivity. Using the G2 assay and the 90th percentile of the controls as a cut off point for sensitivity, no significant difference between the controls and the patient population has been found. However, using the CBMN assay and again the 90th percentile, approximately 11% of the control group are sensitive compared with approximately 40% of the carcinoma cases. The implications of this increased radiosensitivity are as yet unclear, but it is indicative of increased chromosomal fragility and therefore, possibly associated with malignant transformation. Hence, it may prove a useful tool in identifying individuals at increased risk of developing

  3. 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)

  4. Chromosomal instability and the abrogated G2/M arrest in x-irradiated myelodysplastic syndrome cells

    International Nuclear Information System (INIS)

    Ban, S.; Sudo, H.; Saegusa, K.; Sagara, M.; Imai, T.; Kimura, A.

    2003-01-01

    A preliminary epidemiological study demonstrated that myelodysplastic syndrome (MDS) has an excess relative risk per sievert of 13 in atomic bomb survivors in Hiroshima. MDS is the only other radiogenic blood disease apart from leukemia. Clinically, MDS involves dysplastic hematopoiesis and an increased risk of leukemic transformation. Because it is uncertain whether MDS pathogenesis affects lymphoid progenitor cells as well as myeloid progenitor cells, we investigated the karyotypes of bone marrow cells and the micronucleus (MN) frequency in peripheral T lymphocytes of twenty- three atomic bomb survivors with MDS and five normal individuals. Aneuploidy was observed in 10 of 23 patients. Chromosome aberrations were observed in 3 of 12 patients with mild symptoms, and six of 11 patients of severe symptoms. The spontaneous- and X-ray-induced-MN frequencies were significantly higher in MDS patients than in normal individuals. Interestingly, radiation sensitivity increased along with the severity of MDS clinical subtypes. Because many of the patients in this study had not been exposed to chemo- or radiation- therapy, their unusual radiosensitivity may be related to their chromosomal or genomic instability. Immortalized lymphoid cell lines were established from B-lymphocytes infected with Epstein-Barr virus in vitro. The abrogation of radiation-induced-G2/M arrest was observed in 10 of 12 MDS-B lymphoid cell lines, but not in the normal B lymphoid cell lines. Our data suggest that the control of chromosomal stability is impaired in pluripotent stem cells of MDS patients, and that the abrogated G2/M arrest may be involved in the pathophysiology of disease progression and the high radiation sensitivity of patients

  5. Development of resistance to coccidiosis in the absence of merogonic development using X-irradiated Eimeria acervulina oocysts

    International Nuclear Information System (INIS)

    Jenkins, M.C.; Augustine, P.C.; Barta, J.R.; Castle, M.D.; Danforth, H.D.

    1991-01-01

    Sporulated oocysts of the protozoan Eimeria acervulina were subjected to 0, 10, 15, 20, or 30 krad of X-irradiation and inoculated into susceptible outbred chickens to determine if radioattenuated coccidia could induce protection against parasite challenge. Irradiation treatment had an appreciable dose-dependent effect on parasite development. Insignificant numbers of oocysts were produced by chickens inoculated with parasites that had been exposed to greater than 10 krad X-irradiation. Sporozoites exposed to 15 or 20 krad irradiation conferred significant protection against the appearance of intestinal lesions after parasite challenge. Sporozoites subjected to the highest dose level (30 krad) did not produce any significant level of protection. To investigate this phenomenon further and assess intracellular parasite development, susceptible outbred strains of chickens were administered either nonirradiated (0 krad) oocysts or oocysts that were exposed to an optimal dose (15 krad) or a high dose (30 krad) of X-irradiation. Immunofluorescence staining of tissue sections from each treatment group at various intervals after the initial administration of irradiated parasites indicated that sporozoites exposed to 15 krad irradiation were as capable of invading the host intestinal epithelium as nonirradiated sporozoites. However, at 48, 60, 72, and 96 hr, there was a marked reduction in merogonic development in groups receiving irradiated sporozoites compared to those inoculated with nonirradiated parasites. The latter parasites underwent profuse merogonic development; in contrast, irradiated parasites demonstrated little (15 krad) or no (30 krad) merogonic development. These results suggest that induction of a protective immune response occurs during a critical period early in intracellular development of E. acervulina

  6. Effects of ionizing radiation on differentiation of murine bone marrow cells into mast cells

    International Nuclear Information System (INIS)

    Murakami, Sho; Yoshino, Hironori; Ishikawa, Junya; Yamaguchi, Masaru; Tsujiguchi, Takakiyo; Nishiyama, Ayaka; Yokoyama, Kouki; Kashiwakura, Ikuo

    2015-01-01

    Mast cells, immune effector cells produced from bone marrow cells, play a major role in immunoglobulin E–mediated allergic responses. Ionizing radiation affects the functions of mast cells, which are involved in radiation-induced tissue damage. However, whether ionizing radiation affects the differential induction of mast cells is unknown. Here we investigated whether bone marrow cells of X-irradiated mice differentiated into mast cells. To induce mast cells, bone marrow cells from X-irradiated and unirradiated mice were cultured in the presence of cytokines required for mast cell induction. Although irradiation at 0.5 Gy and 2 Gy decreased the number of bone marrow cells 1 day post-irradiation, the cultured bone marrow cells of X-irradiated and unirradiated mice both expressed mast cell–related cell-surface antigens. However, the percentage of mast cells in the irradiated group was lower than in the unirradiated group. Similar decreases in the percentage of mast cells induced in the presence of X-irradiation were observed 10 days post irradiation, although the number of bone marrow cells in irradiated mice had recovered by this time. Analysis of mast cell function showed that degranulation of mast cells after immunoglobulin E–mediated allergen recognition was significantly higher in the X-irradiated group compared with in the unirradiated group. In conclusion, bone marrow cells of X-irradiated mice differentiated into mast cells, but ionizing radiation affected the differentiation efficiency and function of mast cells. (author)

  7. Genetic components for radiosensitivity. Gene expression in radiosensitive monocygotic twins. Final report

    International Nuclear Information System (INIS)

    Dikomey, Ekkehard

    2012-01-01

    The underlying hypothesis of this project was that the variation of individual radiosensitivity is determined by the different expression of single gens. This concept was tested using 60 monozygotic twin pairs, followed by an evaluation with 80 prostate cancer patients. Radiosensitivity was assessed for both G0- as well as G2-phase using chromosomal assays. G0- radiosensitivity is determined by lethal chromosomal aberrations and reflects the individual amount of cell killing, while G2-sensitivity is determined by chromatid breaks and is taken as an indicator of individual cancer risk. For both populations, G0- and G2-radiosensitivity are characterized by substantial variation with a CV of 11 and 14% or 27 and 21%, respectively. While the mean G0-sensitivity is the same for both populations, there is a slight difference for G2. The slightly higher value of G2-sensitivity found for prostate cancer patients might result from the higher age of this group. For both populations gene expression profiles were determined using the Affymetrix chip HG-U133+2.0. Overall gene expression was characterized by a huge variation covering more than four decades. However, for single genes, expression showed little variation with CV generally ranging only between 2 and 8%. Analysis of data using several different methods revealed that variation of both G0- as well as G2-radiosensitivity cannot be ascribed to the different expression of single genes. For twins, random forests can be used to identify 8 to 10 genes than are relevant either for G0- or G2-radiosensitivity. However, these genes cannot be confirmed by an evaluation with 80 prostate cancer patients. This finding clearly demonstrates that the hypothesis, due to which variation of individual radiosensitivity is caused by different expression of single genes, has to be rejected. It appears more likely that this parameter is determined by complex interactions of several genes in functional networks. (orig.)

  8. Radioprotective properties of some heterocyclic nitrogenous compounds against changes in hemoglobin concentration and hematocrit value in x-irradiated mice

    International Nuclear Information System (INIS)

    Rousdhy, H.; Pierotti, T.; Polverelli, M.

    1969-01-01

    Radioprotective properties of imidazole and benzimidazole have been proved in previous works. In this study, authors try to demonstrate radioprotective action of these compounds in comparison with cysteamine upon the hematopoietic system after lethal X-irradiation. Results show: no drastic variations of hematologic constants (hemoglobin concentration and hematocrit value) after intraperitoneal injection of radioprotective compounds apart certain apparent reactions with the heterocyclic compounds; the better radioprotective action of benzimidazole. Twenty five days after irradiation, hemoglobin concentration and hematocrit of radio protected mice return to normal values. (author) [fr

  9. The UV-light and X-irradiation induced conversion of p-phenoxyphenol in aqueous solution at 250C

    International Nuclear Information System (INIS)

    Ehrl, A.

    1975-01-01

    UV-photolysis and X-radiolysis of p-phenoxyphenol was expected to yield products analogous to those of thyronine, after aromatic structures being equivalent. When exposed to UV-light, p-phenoxyphenol was found being selectively converted into phenylhydroquinone in consequence of intramolecular rearrangement. The reaction heat was estimated applying bond energies to the conversion and comparing the result with differences in the combustion heat of homologous compounds. After X-irradiation, phenylhydroquinone however was not present. Formation of the irradiation products phenol, hydroquinone, p-benzoquinone and pyrocatechol presumed breakage of substrate molecules in consequence of intermolecular interaction with transient water radiolysis species. (orig.) [de

  10. Accumulation of lipid peroxidation products in eye structures of mice subjected to whole-body X-irradiation

    International Nuclear Information System (INIS)

    Sakina, N.L.; Dontsov, A.E.; Afanas'ev, G.G.; Ostrovskij, M.A.; Pelevina, I.I.

    1990-01-01

    In studying the effect of whole-body X-irradiation on the accumulation of lipid peroxidation products (conjugated dienes, TBA-active products, and Sciff bases) in retina and retinal pigmented epithelium of pigmented and nonpigmented mice it was shown that irradiation of dark-pigmented mice does not cause even a slight accumulation of lipid peroxidation products as compared to that in the controls. Albino mice exhibited a marked increase in the level of lipid peroxidation products which was manifested soon after irradiation and persisted for at least 3 months after irradiation. Melanine is suggested to participate in protecting eye structures against pro-oxidizing action of ionizing radiation

  11. Studies on c-AMP contents in sea urchin eggs fertilized with normal and x-irradiated sperm

    International Nuclear Information System (INIS)

    Kimura, Hiroshi

    1975-01-01

    Intracellular levels of cyclic 3', 5'-adenosine monophosphate (c-AMP) seemed to remain constant through the first cleavage cycle of sea urchin eggs. X-irradiation to the sperm, which induced the first cleavage delay, did not change this level. Although it was shown in the previous paper that X-ray-induced cleavage delay was reduced by caffeine but not by aminophyline, both caffeine and aminophyline caused an increase in c-AMP levels. These results indicated the possibility that c-AMP does not mediate this caffeine effect on cleavage delay. (auth.)

  12. Effect of X-irradiation on the alanine- and aspartate aminotransferase activity in the liver, kidney and spleen of mice

    Energy Technology Data Exchange (ETDEWEB)

    Jungowska-Klin, B; Lozinska, M; Wojtaszek, J [Wroclaw Univ. (Poland)

    1975-01-01

    The alanine- and aspartate aminotransferase (GOT and GPT) activities and the protein content were measured in the liver, kidney and spleen homogenates of mice exposed to a single whole body X-irradiation with a 900 R dose. The assays were performed in 6 h intervals during the first day and 24 h intervals from the 2nd until the 6th day after the exposure. Significant differences in the enzymatic activity were found in the course of 24 h in control animals and a marked increase of this activity was found after irradiation. This may be explained by changes in the permeability of the mitochondrial membrane for enzyme molecules.

  13. The inhibition of DNA repair by aphidicolin or cytosine arabinoside in X-irradiated normal and xeroderma pigmentosum fibroblasts

    International Nuclear Information System (INIS)

    Waters, R.; Crocombe, K.; Mirzayans, R.

    1981-01-01

    Normal and excision-deficient xeroderma pigmentosum fibroblasts were X-irradiated and the influence on DNA repair of either the repair inhibitor cytosine arabinoside or the specific inhibitor of DNA polymerase α, aphidicolin, investigated. The data indicated that the repair of a certain fraction of X-ray-induced lesions can be inhibited in both cell lines by both compounds. Thus, as aphidicolin blocks the operation of polymerase α, this enzyme must be involved in an excision repair pathway operating in both normal and excision-deficient xeroderma pigmentosum cells. (orig.)

  14. Correlation between residual level of DNA double-strand breaks and the radiosensitivity of cancer cells

    International Nuclear Information System (INIS)

    Sun Jianxiang; Sun Weijian; Sui Jianli; Zhou Pingkun

    2008-01-01

    Objective: To understand the variation of the DNA double-strand break rejoining capacity among different cultured cancer cell lines and the primary cancer cells from brain cancer patients, and to explore the predictor of radiotherapy responses of cancers. Methods: DNA double-strand breaks (DSBs) were induced by 60 Co γ-irradiation. Pulsed-field gel electrophoresis was used to analyze the initial production and rejoining of DNA DSBs. Radiosensitivity was determined by in vitro assay of clonogenic-forming capacity. Results: A wide variation of radiosensitivity, e.g. the survival parameter of Do varied from 0.65 to 2.15 Gy, was displayed among the eight cell lines derived from different type of cancers. Although differential level of initial DNA DSBs induced by 20 Gy γ-rays was observed among various cell lines, it was not correlated with the radiosensitivity. The deficiency of DNA DSB rejoining in radiosensitive cell lines was shown either in the early rapid-rejoining phase (SX-10 cells) or in the late slow-rejoining phase (A2780 cells). A significant relationship was observed between the residual level of DNA DSBs measured at 2 h post-20 Gy irradiation and the cellular radiosensitivity (D 0 or SF 2 ). The kinetic curves of rejoining DNA DSBs in the primary human brain tumor cells indicated a variation on DSB rejoining capacity among different individual tumor. The residual level of DNA DSBs after 2 h of rejoining post 20 Gy irradiation in primary human brain tumor cells is compatible to the results obtained in vitro culture cancer cell lines. Conclusions: The residual level of DNA DSBs is correlated with radioresistance of cancer cells, and the residual DNA damage is a useful parameter in predicting the response of tumor tissue to radiotherapy. (authors)

  15. Evaluation of a MTT assay in measurement of radiosensitizing effect

    International Nuclear Information System (INIS)

    Higuchi, Keiko; Mitsuhashi, Norio; Saitoh, Jun-ichi; Maebayashi, Katsuya; Sakurai, Hideyuki; Akimoto, Tetsuo; Niibe, Hideo

    1999-01-01

    The usefulness of a MTT assay by measuring the radiosensitizing effect of caffeine on rat yolk sac tumor cell line with a mutant-type p53 in vitro was evaluated. A rat yolk sac tumor cell line with a mutant-type p53, NMT-1R, was used in this study. The radiosensitivity of NMT-1R with or without caffeine was measured with a MTT assay. The results were compared with those by a clonogenic assay. Caffeine at a concentration of 2.0 mM which released radiation-induced G 2 block demonstrated a radiosensitizing effect, but caffeine at a concentration of 0.5 mM did not. The radiosensitizing effect of caffeine measured by a MTT assay correlated with that measured by a clonogenic assay. A MTT assay was useful to measure radiosensitivity and/or a radiosensitizing effect in vitro. (author)

  16. Gamma radiosensitivity of a common bean cultivar

    International Nuclear Information System (INIS)

    Colaco, W.; Martinez, C.R.

    1995-01-01

    A preliminary experiment was conducted to evaluate the radiosensitivity of common bean (Phaseolous vulgaris L.), cultivar to gamma rays from a 60 Co source. Sets of seeds (60 seed/sample) irradiated with 50, 100, 150, 200, and 250 Gy, were compared to a control without irradiation (0 Gy), under greenhouse conditions. The radiosensitivity was evaluated through seedling height reduction, determined at 15 days after emergence (DAE), and also through seedling survival, root length, and dry matter production of leaves, shoots and roots. Seedling height was significantly reduced for the treatments with 150 and 250 Gy, in relation to the control. The dose causing reduction of 50% seedling height was between 150 and 200 Gy. Survival rates corresponding to these doses, were, respectively, 85% and 60%. Root length and dry matter of leaves, shoots and roots, were inversely related to the doses. (author). 15 refs, 3 figs, 1 tab

  17. Effect of laser radiation on rat radiosensitivity

    Energy Technology Data Exchange (ETDEWEB)

    Laprun, I.B.

    1979-03-01

    Quite a few experimental data have been obtained to date indicating that radioresistance of the organism is enhanced under the influence of electromagnetic emissions in the radiofrequency and optical ranges. But no studies were made of the possible radioprotective properties of coherent laser radiation. At the same time, it was demonstrated that the low-energy emission of optical quantum generators (lasers) in the red band stimulates the protective forces of the organism and accelerates regenerative processes; i.e., it induces effects that are the opposite of that of ionizing radiation. Moreover, it was recently demonstrated that there is activation of catalase, a radiosensitive enzyme that plays an important role in the metabolism of peroxide compounds, under the influence of lasers. For this reason, the effect of pre-exposure to laser beams on radiosensitivity of rats was tested.

  18. Predictive radiosensitivity tests in human lymphocytes

    International Nuclear Information System (INIS)

    Di Giorgio, Marina; Vallerga, Maria B.; Taja, Maria R.; Sardi, M.; Busto, E.; Mairal, L.; Roth, B.; Menendez, P.; Bonomi, M.

    2004-01-01

    Individual radiosensitivity is an inherent characteristic, associated with an abnormally increased reaction to ionising radiation of both the whole body and cells derived from body tissues. Human population is not uniform in its radiation sensitivity. Radiosensitive sub-groups exist, which would suffer an increased incidence of both deterministic and stochastic effects. Clinical studies have suggested that a large part of the spectrum of normal tissue reaction may be due to differences in individual radiosensitivity. The identification of such sub-groups should be relevant for radiation therapy and radiation protection purposes. It is suggested that DNA repair mechanisms are involved. Consequently, the characterization of DNA repair in lymphocytes through cytokinesis blocked micronucleus (MN) and alkaline single-cell microgel electrophoresis (comet) assays could be a suitable approache to evaluate individual radiosensitivity in vitro. The aims of this study were: 1) To assess the in vitro radiosensitivity of peripheral blood lymphocytes from two groups of cancer patients (prospectively and retrospectively studied), using MN and comet assays, in comparison with the clinical radiation reaction and 2) To test the predictive potential of both techniques for the identification of radiosensitivity sub-groups. 38 cancer patients receiving radiation therapy were enrolled in this study. 19 patients were evaluated prior, mid-way and on completion of treatment (prospective group) and 19 patients were evaluated about 6-18 month after radiotherapy (retrospective group). Cytogenetic data from the prospective group were analysed using a mathematical model to evaluate the attenuation of the cytogenetic effect as a function of the time between a single exposure and blood sampling, estimating a cytogenetic recovery factor k. In the retrospective group, blood samples were irradiated in vitro with 0 (control) or 2 Gy and evaluated using MN test. Cytogenetic data were analysed

  19. Radiosensitizers action on Iodine 131 therapeutical effect

    International Nuclear Information System (INIS)

    Agote, Marcos; Kreimann, Erica L.; Bocanera, Laura V.; Dagrosa, Maria A.; Juvenal, Guillermo J.; Pisarev, Mario A.

    1999-01-01

    Present studies were aimed to research the possible application of a radiosensitizer, nicotinamide, to increase the therapeutical effect of radioiodine. There were used goitrous and normal rats with growing dose of Iodine 131, with and without simultaneous treatment with nicotinamide. The obtained results show that the nicotinamide treatment importantly increases the thyroid radio destructive effect induced by radioiodine. Under these experimental conditions, nicotinamide induces to a significant increase of thyroid vascularisation, without changes in the proteins ADP-ribosylation activity. These results show, for the first time, the radiosensitizer effect of nicotinamide in front of Iodine 131 and give the possibility of using it in the treatment of hyperthyroid or thyroid difference cancer patients. (author)

  20. Radiosensitivity study of salmonella enteritidis in chickens

    International Nuclear Information System (INIS)

    Fernandez Gianotti, Tomas

    1997-01-01

    One of the applications of ionizing radiations in food is the inactivation of vegetative phatogenic bacteria (radicidation) such as Salmonella, Shigella, Campylobacter, Vibro and Listeria. These bacteria are associated with the diseases transmitted by food (ETA). Fresh and frozen farmyard fowls can be contaminated with pathogenic microorganisms, between them Salmonella. In Argentine, between years 1987-1990, Salmonella enteritidis was the main cause of salmonellosis. In food irradiation, with the aim of improving and assuring its hygienic quality, it is important to know the radiosensitivity of microorganisms to be inactivated. Inactivation of a determined microorganism shall depend, between others factors, of the species, strain, number and of the irradiation conditions (temperature, media, etc.). D 10 value is a very useful data in order to compare radiosensitivities between the microorganisms and the influence of different factors in their sensitivities. In this paper, it was determined the sensitivity to the gamma radiation of Salmonella enteritidis in fresh and frozen chickens

  1. Development of a new mouse palate organ culture system and effect of X-irradiation on palatogenesis

    International Nuclear Information System (INIS)

    Hiranuma, Hiroko; Jikko, Akitoshi; Maeda, Takashi; Furukawa, Souhei

    1999-01-01

    On the basis of an already established suspension system of organ culture for mouse palate explants, we developed a new culture system, which has several advantages over the previous methods. We used a 48-well culture plate in which the explants can be cultured individually, and only 300 μl of medium is needed for each well. In order to optimize the culture results, we systematically studied the influence of main ''culture conditions'' such as tilt degree of the culturing palate, rotation speed, and addition of ascorbic acid to the medium. This system allows culturing of palates from day 13.5 of gestation to day 16.5 under serum-free conditions using a chemically defined medium, which resulted in 78% of the palates growing fused. Utilizing this culture system, the direct effect of X-irradiation on palataogesis was analyzed. A 4 Gy dose of X-irradiation was administrated at the beginning of culture period. The incidence of palatal fusion was not significantly different from that of the non-irradiated group. (author)

  2. X-irradiation effects on growth and metamorphosis of gastropod larvae (Crepidula fornicata): A model for environmental radiation teratogenesis

    International Nuclear Information System (INIS)

    Gould, L.; Lord, A.; Pechenik, J.; Kase, K.; Fitzgerald, T.J.; Greenberger, J.S.

    1985-01-01

    Little information is available on the effects of x-irradiation on multicellular marine organisms. C. fornicata larvae were irradiated at 200 rad/min, 250 kVp x-rays to doses between 50 and 20,000 rad in a single fraction. Shell length, biomass, metamorphosis to the next stage of development, and mortality were measured. The results demonstrated a dose-dependent decrease in 20 day shell length at doses above 2000 rad (control 850 +- 110 μm length, 820 +- 100μm for 50 rad, 750 +- 30 μm for 2000 rad, 710 +- 30 μm for 5000 rad, 620 +- 30 μm for 10,000 rad, 580 +- 15 μm for 20,000 rad). There was a dose dependent decrease in shell length growth between days 1 and 20. Biomass was significantly decreased per 100μm shell length for doses above 10,000 rad. A significant increase in larvae mortality was detected with doses above 2000 rad. Most significantly, the cumulative percent of larval metamorphosis was significantly decreased by doses as low as 500 rad and was detectable as early as 18 days after irradiation. C. fornicata may provide a very sensitive system in which to study teratogenic effects of x-irradiation on multicellular organisms

  3. X-irradiation effects on growth and metamorphosis of gastropod larvae (Crepidula fornicata): a model for environmental radiation teratogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Greenberger, J S; Pechenik, J; Lord, A; Gould, L; Naparstek, E; Kase, K; FitzGerald, T J

    1986-02-01

    Little information is available on the effects of x-irradiation on the development of multicellular marine organisms. Larvae of the marine gastropod Crepidula fornicata were irradiated at 200 rad/min, 250 kVp X-rays, to doses between 500 and 20,000 rad in a single fraction. During the weeks following exposure, changes in shell length and biomass, incidence of metamorphosis to the juvenile stage of development, and mortality were measured. The results over a 20-day period demonstrated a dose-dependent decrease in growth rate of larval shells following doses above 2000 rad (control at day 20 = 850 +/- 110 ..mu..m length, 820 +/- 11 ..mu..m for 500 rad, 750 +/- 30 ..mu..m for 2000 rad, 710 +/- 30 ..mu..m for 5000 rad, 620 +/- 30 ..mu..m for 10,000 rad, and 580 +/- 15 ..mu..m for 20,000 rad). Shell length-specific biomass was significantly decreased for doses above 10,000 rad. A significant increase in larval mortality was detected with doses above 2000 rad. The cumulative percent of larval metamorphosis was decreased by exposures to 5000 rad and was detectable as early as 18 days after irradiation; however, metamorphosis of larvae after 5000 rad occurred faster by day 21 while other groups metamorphosis required 34-35 days for completion. Crepidula fornicata may provide a very sensitive and convenient system in which to study teratogenic effects of x-irradiation on multicellular organisms.

  4. Ataxia-telangiectasia cells are not uniformly deficient in poly(ADP-ribose) synthesis following X-irradiation

    International Nuclear Information System (INIS)

    Zwelling, L.A.; Kerrigan, D.; Mattern, M.R.

    1983-01-01

    The synthesis of poly(adenosine diphosphoribose [poly(ADP-R)] follows the DNA strand breakage produced by a number of physical and chemical agents, including X-radiation, and may be important for repair of several types of DNA damage. The reduction or abolition of its synthesis following X-irradiation might explain the enhanced sensitivity of ataxia-telangiectasia (A-T) cells to X-ray. We have examined 8 lines of human fibroblasts (including 4 A-T lines) for stimulation of the synthesis of poly(ADP-R) by X-irradiation. Similar amounts of X-ray-stimulated synthesis of poly(ADP-R) were detected in 4 lines of A-T fibroblasts, and in fibrolasts from a xeroderma pigmentosum (XP) patient, a Fanconi's anemia (FA) patient and 2 normal patients. 6 lines of human lymphoblastoid lines were also examined for X-ray-stimulated poly(ADP-R) synthesis. 4 A-T lines displayed an unusually high synthesis of poly(ADP-R) in unirradiated cells compared with 2 normal lines. (orig./AJ)

  5. Ataxia-telangiectasia cells are not uniformly deficient in poly(ADP-ribose) synthesis following X-irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Zwelling, L.A.; Kerrigan, D. (National Cancer Inst., Bethesda, MD (USA). Lab. of Molecular Pharmacology); Mattern, M.R. (National Cancer Inst., Bethesda, MD (USA). Lab. of Molecular Carcinogenesis)

    1983-04-01

    The synthesis of poly(adenosine diphosphoribose (poly(ADP-R)) follows the DNA strand breakage produced by a number of physical and chemical agents, including X-radiation, and may be important for repair of several types of DNA damage. The reduction or abolition of its synthesis following X-irradiation might explain the enhanced sensitivity of ataxia-telangiectasia (A-T) cells to X-ray. We have examined 8 lines of human fibroblasts (including 4 A-T lines) for stimulation of the synthesis of poly(ADP-R) by X-irradiation. Similar amounts of X-ray-stimulated synthesis of poly(ADP-R) were detected in 4 lines of A-T fibroblasts, and in fibrolasts from a xeroderma pigmentosum (XP) patient, a Fanconi's anemia (FA) patient and 2 normal patients. 6 lines of human lymphoblastoid lines were also examined for X-ray-stimulated poly(ADP-R) synthesis. 4 A-T lines displayed an unusually high synthesis of poly(ADP-R) in unirradiated cells compared with 2 normal lines.

  6. Effect of ethyl methanesulphonate and X-irradiation on the spermatocyte chromosomes of the grasshopper, Gesonula punctifrons

    International Nuclear Information System (INIS)

    Ghosh, Mita; Majumdar, K.C.; Duttagupta, A.K.

    1977-01-01

    Present investigation was performed to find out the effect of ethyl methanesulfonate (EMS) and X-irradiation on the meiotic cells of the grasshopper Gesonula punctifrons. Adult male grasshoppers were administered EMS (intraperitoneal injection) with one of the following concentration : 0.05%, 0.05% + 0.05%, 0.1%, 0.2%. Only 0.002 ml of required concentration were injected/animal and irradiated with 200R of X-ray in one acute dose/animal as per experimental schedule. Controls were injected with distilled water with a quantity 0.002 ml/animal. Treated and control animals were sacrificed 24 hours and 48 hours after treatment and the dividing spermatocytes were analysed for chromosomal aberrations. It was shown that EMS had stage spcificity as compared to the 200R of X-ray on the production of chromosome aberrations. Combined treatment of X-ray and EMS showed an additive effect compared to the individual effect of X-irradiation or EMS. (author)

  7. Procaine-mediated modification of membranes and of the response to x irradiation and hyperthermia in mammalian cells

    International Nuclear Information System (INIS)

    Yau, T.M.

    1979-01-01

    Procaine, a membrane-specific agent, was found to protect the response of oxygenated mammalian cells toward x irradiation in vitro. In addition, the drug also potentiates hyperthermic killing of cells. In an effort to gain further insights into the mechanisms underlying the action of procaine as a modifier of cell injury in x-irradiated and heated cells, the effects of procaine on cellular morphology, membrane fluidity, and cellular electrokinetic properties were studied. It was found that procaine can reversibly influence the cellular morphology. Using scanning electron microscopy, we were able to demonstrate the presence of numerous smooth blebs on the cell surface of either normal or SV40-transformed 3T3 mouse fibroblasts treated with procaine. When 1,6-diphenyl-1,3,5-hexatriene was used as a membrane probe, the overall fluidity of cell membranes from 3T3 cells grown as monolayers or L5178Y lymphoma cells grown in suspensions was not significantly changed by procaine; however, when perylene was used as a probe, the overall fluidity of cell membranes of procaine-treated cells was found to increase significantly. Lastly, procaine was found to alter the electrophoretic mobility of cells. These results indicate that procaine may exert its modification of radiation- and heat-induced effects via a still elusive membrane-mediated mechanism(s). It is anticipated that membrane-active agents with different specificities may be employed as tools to probe the role of membranes in the radiation or heat response of cells

  8. Types and three-dimensional distribution of neuronal ectopias in the brain of mice prenatally subjected to X-irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Xue-Zhi; Takahashi, Sentaro; Kubota, Yoshihisa; Sato, Hiroshi [National Inst. of Radiological Sciences, Chiba (Japan); Cui, Chun; Fukui, Yoshihiro [Tokushima Univ. (Japan). School of Medicine; Inouye, Minoru [Shin Nippon Biomedical Lab., Ltd., Miyanoura, Kagoshima (Japan)

    2002-03-01

    The types and three-dimensional distribution of neocortical ectopias following prenatal exposure to X-irradiation were studied by a histological examination and computer reconstruction techniques. Pregnant ICR mice were subjected to X-irradiation at a dose of 1.5 Gy on embryonic day 13. The brains from 30-day-old mice were serially sectioned on the frontal plane at 15 {mu}m, stained with HE and observed with a microscope. The image data for the sections were input to a computer, and then reconstructed to three-dimensional brain structures using the Magellan 3.6 program. Sectional images were then drawn on a computer display at 240 {mu}m intervals, and the positions of the different types of neocortical ectopias were marked using color coding. Three types of neocortical ectopias were recognized in the irradiated brains. Neocortical Lay I ectopias were identified as small patches in the caudal occipital cortex, and were located more laterally in the neocortex in caudal sections than in the rostral sections. Periventricular ectopias were located more rostrally than Lay I ectopias, and were found from the most caudal extent of the presumed motor cortex to the most caudal extent of the lateral ventricle. Hippocampal ectopias appeared as continuous linear bands, and were frequently associated with the anterior parts of the periventricular ectopias. (author)

  9. G2 block in Chinese hamster cells induced by x-irradiation, hyperthermia, cycloheximide, or actinomycin-D

    International Nuclear Information System (INIS)

    Dewey, W.C.; Highfield, D.P.

    1976-01-01

    The entry of cells into mitosis was monitored by shaking off mitotic cells from monolayer cultures. The location in G 2 of the x-ray transition point (TP), beyond which the cells were not delayed by x irradiation moved closer to mitosis as the dose was increased, i.e., at 10 min before prophase for 100 to 200 rad, and at 19 min for 30 to 60 rad. Treatment with cycloheximide (CH, 20 μg/ml) at the time of irradiation (50 to 100 rad) shifted the TP for x irradiation by 5 to 9 min toward mitosis. Calculations from these shifts in TP with radiation dose indicated that the logarithm of both the fraction of cells in G 2 not delayed by irradiation and the fraction beyond the TP for CH (located at 26 min before phophase for 5 to 50 μg/ml) not delayed by irradiation decreased linearly with dose (anti D 0 of 30 rad). Furthermore, inhibition of protein synthesis by CH, with or without a simultaneous treatment with actinomycin D (AMD), prevented repair of damage causing mitotic delay for a period of time equal to the duration of the CH treatment

  10. Effects of X-irradiation and thymectomy on the immune response of the marine teleost, Sebastiscus marmoratus

    International Nuclear Information System (INIS)

    Nakanishi, T.

    1986-01-01

    Effects of X-irradiation and thymectomy on the immune response of the rock fish, S. marmoratus were studied. Animals were thymectomized and irradiated at the dose of 2000 R. In non-thymectomized and irradiated fish, injected with SRBC one week after irradiation, antibody production was completely suppressed and they required twice the time for rejection of scales allografted three days after irradiation. On the other hand, fish which were irradiated four days after thymectomy and injected one week after irradiation, showed a fairly high level of antibody, although, in the allograft rejection, no significant difference was observed when compared to the irradiated fish. Furthermore, animals thymectomized, irradiated and autoimplanted showed higher production of antibody when immunized three months after irradiation compared to matched controls. In the same manner, in the allograft rejection, a slight restoration was found in fish reconstituted with a non-irradiated thymus. From these results, it is considered that, as in mammals, the adult thymus of fish plays an important role in recovery from the damage to the immune system caused by irradiation. Furthermore, a combination of X-irradiation and thymectomy suggests that suppressor T-cells which are resistant to X-rays exist in the fish thymus

  11. The effect of X-irradiation on Na-K ATPase and cation distribution in rabbit lens

    International Nuclear Information System (INIS)

    Matsuda, H.; Giblin, F.J.; Reddy, V.N.

    1982-01-01

    The Na-K ATPase activity of rabbit lens was measured at various times after exposure to a single dose of 2000 rads of X-ray and was compared with that in contralateral control eyes. A decrease in enzyme activity in both whole lens and in isolated capsule-epithelium was first observed 3 to 4 weeks after irradiation and became increasingly marked at 7.5 weeks after X-ray. These findings are consistent with our earlier observations that active transport of cations is reduced in these lenses and support the view that loss of membrane ATPase is responsible for the impairment of the cation pump in X-irradiated lenses. Despite a significant loss of the enzyme, X-irradiated lenses were able to maintain near normal levels of total cations (Na+ + K+), thus accounting for their normal hydration. The results of the changes in lens Na+ and K+ levels revealed that between 4 and 7.5 weeks after X-ray, the gain in Na+ was compensated by an equivalent loss of K+. A breakdown of this relationship of 1:1 exchange of Na+ for K+ is accompanied by a disproportionate increase in Na+ and water

  12. Characterization of the multiple drug resistance phenotype expressed by tumour cells following in vitro exposure to fractionated X-irradiation

    International Nuclear Information System (INIS)

    Hill, B.T.; McClean, S.; Hosking, L.; Shellard, S.; Dempke, W.; Whelan, R.

    1992-01-01

    The major clinical problem of the emergence of drug resistant tumor cell populations is recognized in patients previously treated with antitumor drugs and with radiotherapy. It is proposed that, although radiation-induced vascular fibrosis may limit drug delivery to the tumor, exposure to radiation may 'induce' or 'select for' drug resistance. This hypothesis was examined by establishing in vitro model systems to investigate the resistance phenotype of tumor cells following exposure to X-rays. Characteristically tumor cells surviving exposure to a series of fractions of X-irradiation are shown to have consistently expressed resistance to multiple drugs, including the Vinca alkaloids and the epipodophyllotoxins. Currently this research is aimed at determining whether distinctive resistance mechanisms operate depending on whether resistance results following drug or X-ray exposure. Initial results indicate that whilst some common mechanisms operate, drug resistant tumor cells identified following exposure to X-irradiation appear to exhibit a novel multidrug resistance phenotype. (author). 13 refs., 1 tab

  13. Radiosensitivity of primary cultured fish cells with different ploidy

    International Nuclear Information System (INIS)

    Mitani, Hiroshi; Egami, Nobuo; Kobayashi, Hiromu.

    1986-01-01

    The radiosensitivity of primary cultured goldfish cells (Carassius auratus) was investigated by colony formation assay. The radiosensitivity of cells from two varieties of goldfish, which show different sensitivity to lethal effect of ionizing radiation in vivo, was almost identical. Primary cultured cells from diploid, triploid and tetraploid fish retained their DNA content as measured by microfluorometry, and the nuclear size increases as ploidy increases. However, radiosensitivity was not related to ploidy. (author)

  14. DNA repair , cell repair and radiosensitivity

    International Nuclear Information System (INIS)

    Zhestyanikov, V.D.

    1983-01-01

    Data obtained in laboratory of radiation cytology and literature data testifying to a considerable role of DNA repair in cell sensitivity to radiation and chemical DNA-tropic agents have been considered. Data pointing to the probability of contribution of inducible repair of DNA into plant cells sensitivity to X-rays are obtained. Certain violations of DNA repair do not result in the increase of radiosensitivity. It is assumed that in the cases unknown mechanisms of DNA repair operate

  15. Radiosensitivity of red flour beetle tribolium castaneum

    International Nuclear Information System (INIS)

    Sattar, A.; Khattak, S.; Hamed, M.

    1992-07-01

    In this report radiosensitivity of red beetle has been discussed. Red flour beetle is the most injurious pest causing great losses to stored grain. Radiation is one of the best tools of insect control. Different radiation doses (50 to 200 krads) were employed for different age groups from 1 to 60 days. It is concluded from these results that 200 krad radiation dose caused 100% mortality in red beetle in all age group. (A.B.)

  16. Evidence for the re-establishment of a heterogeneity in radiosensitivity among spermatogonial stem cells repopulating the mouse testis following depletion by X-rays

    International Nuclear Information System (INIS)

    Cattanach, B.M.; Barlow, J.H.

    1984-01-01

    Earlier studies have shown that the spermatogonial stem cells of the mouse testis recovering from previous radiation or chemical mutagen exposure give subnormal yields of genetic damage with subsequent X-irradiation. This response has been investigated further: (a) with a high, 9-Gy X-ray dose given 4, 12 or 21 days after a 1-Gy conditioning dose and (b) with a 1 + 7-Gy, 24-h fractionation regime given 4 or 14 days after a 1-Gy conditioning dose. The results of the experiments suggest that a heterogeneity in radiosensitivity, such as exists in unirradiated stem cell populations and absent 24-48 h after radiation depletion, is quickly re-established among the stem cells repopulating the testis. And that the newly established heterogeneity is removed by the second 1-Gy conditioning dose. With longer intervals between treatments, genetic yields consistent with additivity were obtained in Expt. 1; less clear results were obtained in Expt. 2. Comparison with earlier data generally suggested that the duration of the repopulating period is dose-dependent. In a third experiment evidence was obtained that genetic damage induced by X-irradiation can be reduced by a subsequent treatment with triethylenemelamine (TEM) during the repopulating phase. This confirmed an earlier finding. Such an interaction could not be demonstrated with two X-ray treatments. An explanation for the X-ray/TEM interaction is offered. (Auth.)

  17. Clinical studies on radiosensitization of cervical cancer by cisplatinum

    International Nuclear Information System (INIS)

    Yu Shiying; Chen Yuan; Xu Zhiqiang

    1993-01-01

    A prospective randomized clinical trial on the radiosensitizing effect of cisplatinum was carried out in 60 patients with cervical cancer, of whom 30 were given cisplatinum in combination with radiotherapy (radiosensitizing group) and the remaining 30 radiotherapy alone (control group). The results showed that the length of time of immediate CR and PR was shorter in the radiosensitizing group than in the control group. The sensitive enhancement ratio was 1.846. No toxicity was observed in the radiosensitizing group, and the treatment was well tolerated by the patients

  18. Catecholamines of the body tissues and radiosensitivity of rodents

    Energy Technology Data Exchange (ETDEWEB)

    Grayevskaya, V M; Zolotariova, N N [AN SSSR, Moscow. Inst. Morfologii Zhivotnykh

    1975-01-01

    Various species of rodents are distinguished by their radiosensitivity (increasing): bank vole < Wistar rat < wild mouse < CC/sub 57/Br mouse < golden hamster < BALB mouse < guinea pig. There is a positive correlation between radiosensitivity of these species and catecholamines content in the adrenals, urea and blood; and negative correlation between radiosensitivity and adrenaline and noradrenaline concentrations in liver and spleen cells. Presumable causes of this correlation, and the possibility of application of the index under study for predicting the organism radiosensitivity and forecasting the outcome of radiation damage are discussed.

  19. Catecholamines of the body tissues and radiosensitivity of rodents

    International Nuclear Information System (INIS)

    Grayevskaya, V.M.; Zolotariova, N.N.

    1975-01-01

    Various species of rodents are distinguished by their radiosensitivity (increasing): bank vole 57 Br mouse < golden hamster < BALB mouse < guinea pig. There is a positive correlation between radiosensitivity of these species and catecholamines content in the adrenals, urea and blood; and negative correlation between radiosensitivity and adrenaline and noradrenaline concentrations in liver and spleen cells. Presumable causes of this correlation, and the possibility of application of the index under study for predicting the organism radiosensitivity and forecasting the outcome of radiation damage are discussed

  20. Radiosensitivity related to neuroendocrine and endodermal differentation in lung carcinoma lines

    International Nuclear Information System (INIS)

    Duchesne, G.; Casoni, A.; Pera, M.

    1988-01-01

    A panel of human lung carcinoma lines was studied with respect to hormone production and intermediate filament expression to distinguish between endodermal and neuroendocrine differentation. An index of the degree of neuroendocrine differentiation of each line was derived from the presence or absence of hormone production, cytokeratins, neurofilaments and an embryonic endodermal cell marker, which allowed identification of three groups showing high, intermediate or low neuroendocrine expression. This grouping correlated well with the in vitro radiosensitivity of the lines, those expressing pure neuroendocrine features being significantly more radiosensitive than those with an endodermal phenotype, with the intermediate group having intermediate sensitivity. Use of such an index might predict those patients likely to benefit from the use of radiotherapy in their management. 30 refs.; 3 figs.; 3 tabs

  1. Relation between number of hemopoietic stem cells in newborn mice and their radiosensitivity

    International Nuclear Information System (INIS)

    Sutter, T.; Maes, J.; Gerber, G.B.; Leonard, A.

    1985-01-01

    Fractionation of a radiation exposure causes greater damage in newborn mice than a single application since it induces radioresistant foetal hemopoietic stem cells to differentiate prematurely to more radiosensitive adult ones. In the present investigation, it was studied whether other agents that give rise to extensive stem cell destruction also lead to such a change in radiosensitivity. Indeed, treatment with cytostatic drugs which reduces the number of spleen colony forming units (CFU-s) and total cells also diminished the D 0 value of the surviving cells 3 days later. Adriamycin was most effective in causing damage to hemopoietic stem cells and in inducing micronuclei in bone marrow; it also had the most marked action on the D 0 of the surviving stem cells. (orig.)

  2. Wnt activation affects proliferation, invasiveness and radiosensitivity in medulloblastoma.

    Science.gov (United States)

    Salaroli, Roberta; Ronchi, Alice; Buttarelli, Francesca Romana; Cortesi, Filippo; Marchese, Valeria; Della Bella, Elena; Renna, Cristiano; Baldi, Caterina; Giangaspero, Felice; Cenacchi, Giovanna

    2015-01-01

    Medulloblastomas (MBs) associated with the Wnt activation represent a subgroup with a favorable prognosis, but it remains unclear whether Wnt activation confers a less aggressive phenotype and/or enhances radiosensitivity. To investigate this issue, we evaluated the biological behavior of an MB cell line, UW228-1, stably transfected with human β-catenin cDNA encoding a nondegradable form of β-catenin (UW-B) in standard culture conditions and after radiation treatment. We evaluated the expression, transcriptional activity, and localization of β-catenin in the stably transfected cells using immunofluorescence and WB. We performed morphological analysis using light and electron microscopy. We then analyzed changes in the invasiveness, growth, and mortality in standard culture conditions and after radiation. We demonstrated that (A) Wnt activation inhibited 97 % of the invasion capability of the cells, (B) the growth of the UW-B cells was statistically significantly lower than that of all the other control cells (p < 0.01), (C) the mortality of irradiated UW-B cells was statistically significantly higher than that of the controls and their nonirradiated counterparts (p < 0.05), and (D) morphological features of neuronal differentiation were observed in the Wnt-activated cells. In tissue samples, the Ki-67 labeling index (LI) was lower in β-catenin-positive samples compared to non-β-catenin positive ones. The Ki-67 LI median (LI = 40) of the nuclear β-catenin-positive tumor samples was lower than that of non-nuclear β-catenin-positive samples (LI = 50), but the difference was not statistically significant. Overall, our data suggest that activation of the Wnt pathway reduces the proliferation and invasion of MBs and increases the tumor's radiosensitivity.

  3. Repopulation of the seminiferous epithelium of the rhesus monkey after X irradiation

    International Nuclear Information System (INIS)

    van Alphen, M.M.; van de Kant, H.J.; de Rooij, D.G.

    1988-01-01

    Repopulation of the seminiferous epithelium became evident from Day 75 postirradiation onward after doses of 0.5, 1.0, and 2.0 Gy of X rays. Cell counts in cross sections of seminiferous tubules revealed that during this repopulation the numbers of Apale (Ap) spermatogonia, Adark (Ad) spermatogonia, and B spermatogonia increased simultaneously. After 0.5 Gy the number of spermatogonia increased from approximately 10% of the control level at Day 44 to 90% at Day 200. After 1.0 and 2.0 Gy the numbers of spermatogonia increased from less than 5% at Day 44 to 70% at Days 200 and 370. The number of Ad and B spermatogonia, which are considered to be resting and differentiating spermatogonia, respectively, already had increased when the number of proliferating Ap spermatogonia was still very low. This early inactivation and differentiation of a large part of the population of Ap spermatogonia slows down repopulation of the seminiferous epithelium of the primates. By studying repopulating colonies in whole mounts of seminiferous tubules various types of colonies were found. In colonies consisting of only A spermatogonia, 40% of the A spermatogonia were found to be of the Ad type, which indicates that even before the colony had differentiated, 40% of the A spermatogonia were inactivated into Ad. Differentiating colonies were also found in which one or two generations of germ cells were missing. In some of those colonies it was found that the Ap spermatogonia did not form any B spermatogonia during one or two cycles of the seminiferous epithelium, while in other colonies all Ap spermatogonia present had differentiated into B spermatogonia. This indicates that the differentiation of Ap into B spermatogonia is a stochastic process

  4. Sensing radiosensitivity of human epidermal stem cells

    International Nuclear Information System (INIS)

    Rachidi, Walid; Harfourche, Ghida; Lemaitre, Gilles; Amiot, Franck; Vaigot, Pierre; Martin, Michele T.

    2007-01-01

    Purpose: Radiosensitivity of stem cells is a matter of debate. For mouse somatic stem cells, both radiosensitive and radioresistant stem cells have been described. By contrast, the response of human stem cells to radiation has been poorly studied. As epidermis is a radiosensitive tissue, we evaluated in the present work the radiosensitivity of cell populations enriched for epithelial stem cells of human epidermis. Methods and materials: The total keratinocyte population was enzymatically isolated from normal human skin. We used flow cytometry and antibodies against cell surface markers to isolate basal cell populations from human foreskin. Cell survival was measured after a dose of 2 Gy with the XTT assay at 72 h after exposure and with a clonogenic assay at 2 weeks. Transcriptome analysis using oligonucleotide microarrays was performed to assess the genomic cell responses to radiation. Results: Cell sorting based on two membrane proteins, α6 integrin and the transferrin receptor CD71, allowed isolation of keratinocyte populations enriched for the two types of cells found in the basal layer of epidermis: stem cells and progenitors. Both the XTT assay and the clonogenic assay showed that the stem cells were radioresistant whereas the progenitors were radiosensitive. We made the hypothesis that upstream DNA damage signalling might be different in the stem cells and used microarray technology to test this hypothesis. The stem cells exhibited a much more reduced gene response to a dose of 2 Gy than the progenitors, as we found that 6% of the spotted genes were regulated in the stem cells and 20% in the progenitors. Using Ingenuity Pathway Analysis software, we found that radiation exposure induced very specific pathways in the stem cells. The most striking responses were the repression of a network of genes involved in apoptosis and the induction of a network of cytokines and growth factors. Conclusion: These results show for the first time that keratinocyte

  5. MicroRNA-449a enhances radiosensitivity in CL1-0 lung adenocarcinoma cells.

    Directory of Open Access Journals (Sweden)

    Yi-Jyun Liu

    Full Text Available Lung cancer is the leading cause of cancer-related mortality worldwide. Radiotherapy is often applied for treating lung cancer, but it often fails because of the relative non-susceptibility of lung cancer cells to radiation. MicroRNAs (miRNAs have been reported to modulate the radiosensitivity of lung cancer cells and have the potential to improve the efficacy of radiotherapy. The purpose of this study was to identify a miRNA that can adjust radiosensitivity in lung adenocarcinoma cells. Two lung adenocarcinoma cell lines (CL1-0 and CL1-5 with different metastatic ability and radiosensitivity were used. In order to understand the regulatory mechanisms of differential radiosensitivity in these isogenic tumor cells, both CL1-0 and CL1-5 were treated with 10 Gy radiation, and were harvested respectively at 0, 1, 4, and 24 h after radiation exposure. The changes in expression of miRNA upon irradiation were examined using Illumina Human microRNA BeadChips. Twenty-six miRNAs were identified as having differential expression post-irradiation in CL1-0 or CL1-5 cells. Among these miRNAs, miR-449a, which was down-regulated in CL1-0 cells at 24 h after irradiation, was chosen for further investigation. Overexpression of miR-449a in CL1-0 cells effectively increased irradiation-induced DNA damage and apoptosis, altered the cell cycle distribution and eventually led to sensitization of CL1-0 to irradiation.

  6. Radiosensitivity of grapevines. Empirical modelling of the radiosensitivity of some clones to x-ray irradiation. Pt. 1

    International Nuclear Information System (INIS)

    Koeroesi, F.; Jezierska-Szabo, E.

    1999-01-01

    Empirical and formal (Poisson) models were utilized, applying experimental growth data to characterize the radiosensitivity of six grapevine clones to X-ray irradiation. According to the radiosensitivity constants (k), target numbers (n) and volumes, GR 37 doses and energy deposition, the following radiosensitivity order has been found for various vine brands: Chardonnay clone type < Harslevelue K. 9 < Koevidinka K. 8 < Muscat Ottonel clone type < Irsai Oliver K. 11 < Cabernet Sauvignon E. 153. The model can be expanded to describe the radiosensitivity of other plant species and varieties, and also the efficiency of various radioprotecting agents and conditions. (author)

  7. Enhanced apoptosis and radiosensitization by combined 13-CIS-retinoic acid and interferon-α2a; role of RAR-β gene

    International Nuclear Information System (INIS)

    Ryu, Samuel; Stein, Joseph P.; Chung, Chung T.; Lee, Yong J.; Kim, Jae Ho

    2001-01-01

    Purpose: Combined use of 13-cis-retinoic acid (cRA) and interferon-α2a (IFNα) induced significant radiosensitization in human cervical cancer ME-180 cell line, whereas it failed to achieve similar radiation enhancement in HeLa cells. The differential radiosensitization could be from the difference of retinoic acid receptor (RAR) expression because RAR-β was highly expressed in ME-180 cells in contrast to the HeLa cells where RAR-β was not detectable. We examined the role of this gene in mediating radiosensitization by cRA and IFNα, and explored the mechanism of radiation-induced cell killing. Methods and Materials: Human cervical cancer cell lines, ME-180 and HeLa, were treated with cRA and IFNα followed by radiation. Apoptosis and radiosensitization were quantitated by TUNEL assay (in situ DNA nick end labeling) and colony-forming ability of surviving cells. The cells were transfected with bcl-2 gene and RAR-β gene to test the role of these genes in mediating radiosensitization and apoptosis. Results: Synergistic radiosensitization and apoptosis was observed by combined use of cRA and IFNα with radiation in ME-180 cells which express high level of RAR-β mRNA, whereas these were not seen in HeLa cells where RAR-β mRNA is not detectable. Both radiosensitization and apoptosis were abolished by bcl-2 gene in ME-180 cells. RAR-β gene transfection induced similar radiation enhancement and apoptosis in HeLa cells. Conclusion: Apoptosis and radiation response were enhanced in the cells with high level of RAR-β mRNA expression. The RAR-β gene appears to mediate the radiation-induced apoptosis by cRA and IFNα. These findings indicate that presence of RAR-β in the cancer cells could be exploited for patient selection in using these drugs for apoptosis and radiosensitization

  8. Targeting Mcl-1 for Radiosensitization of Pancreatic Cancers

    Directory of Open Access Journals (Sweden)

    Dongping Wei

    2015-02-01

    Full Text Available In order to identify targets whose inhibition may enhance the efficacy of chemoradiation in pancreatic cancer, we previously conducted an RNAi library screen of 8,800 genes. We identified Mcl-1 (myeloid cell leukemia-1, an anti-apoptotic member of the Bcl-2 family, as a target for sensitizing pancreatic cancer cells to chemoradiation. In the present study we investigated Mcl-1 inhibition by either genetic or pharmacological approaches as a radiosensitizing strategy in pancreatic cancer cells. Mcl-1 depletion by siRNA produced significant radiosensitization in BxPC-3 and Panc-1 cells in association with Caspase-3 activation and PARP cleavage, but only minimal radiosensitization in MiaPaCa-2 cells. We next tested the ability of the recently identified, selective, small molecule inhibitor of Mcl-1, UMI77, to radiosensitize in pancreatic cancer cells. UMI77 caused dissociation of Mcl-1 from the pro-apoptotic protein Bak and produced significant radiosensitization in BxPC-3 and Panc-1 cells, but minimal radiosensitization in MiaPaCa-2 cells. Radiosensitization by UMI77 was associated with Caspase-3 activation and PARP cleavage. Importantly, UMI77 did not radiosensitize normal small intestinal cells. In contrast, ABT-737, an established inhibitor of Bcl-2, Bcl-XL, and Bcl-w, failed to radiosensitize pancreatic cancer cells suggesting the unique importance of Mcl-1 relative to other Bcl-2 family members to radiation survival in pancreatic cancer cells. Taken together, these results validate Mcl-1 as a target for radiosensitization of pancreatic cancer cells and demonstrate the ability of small molecules which bind the canonical BH3 groove of Mcl-1, causing displacement of Mcl-1 from Bak, to selectively radiosensitize pancreatic cancer cells.

  9. Low-dose X-irradiation of adjuvant-induced arthritis in rats. Efficacy of different fractionation schedules

    International Nuclear Information System (INIS)

    Liebmann, A.; Hindemith, M.; Jahns, J.; Kamprad, F.; Hildebrandt, G.; Madaj-Sterba, P.; Weisheit, S.

    2004-01-01

    Background and purpose: low-dose radiotherapy is widely accepted as a very effective treatment option for inflammatory symptoms associated with painful degenerative joint disorders. Radiation doses and fractionation schedules in practical use are empirical and mainly based on clinical observations. Experimental data are rare. The efficacy of low-dose X-irradiation on adjuvant induced arthritis in rats using different fractionation schemes was investigated in vivo, in order to explore whether there is a dose and fractionation dependence. Material and methods: adjuvant arthritis in female lewis rats (n = 128) was induced by intradermal injection of heat-inactivated Mycobacterium tuberculosis on day 0. Both arthritic hind paws were sham-irradiated (group 1: days 10-14; group 2: days 15-19; group 3: days 22-26) or X-irradiated with either 5 x 1.0 Gy (group 4: days 10-14; group 6: days 15-19; group 8: days 22-26; group 10: days 10, 12, 14, 16, and 18) or 5 x 0.5 Gy (group 5: days 10-14; group 7: days 15-19; group 9: days 22-26; group 11: days 10, 12, 14, 16, and 18; group 12: days 10-14 and 22-26). The clinical parameters arthritis score (AS), hind paw volume (HPV), and body weight were determined. Results: a significant decrease of the clinical arthritis parameters was observed following 5 x 0.5 Gy or 5 x 1.0 Gy during the acute maximum of the inflammatory response (days 15-19). The most pronounced treatment effect was reached after two daily fractionated series of 5 x 0.5 Gy with an early treatment onset (days 10-14) and repetition in interval (days 22-26). After the application of 5 x 1.0 Gy on days 10-14 or in a protracted scheme (days 10, 12, 14, 16, and 18), only a nonsignificant positive trend could be detected. Daily fractionated X-irradiation in the chronic phase of adjuvant arthritis (days 22-26) did not show any positive clinical effect. Conclusion: low-dose radiotherapy is able to prevent a full-blown arthritic reaction if given during the florid phase of

  10. Increase of survival of x-irradiated mice by postirradiation injections of a splenic extract prepared from vaccine or endotoxin-treated syngeneic animals

    Energy Technology Data Exchange (ETDEWEB)

    Tsuneoka, K; Takagi, Y; Shikita, M [National Inst. of Radiological Sciences, Chiba (Japan)

    1977-05-01

    Spleens of mice which had been treated with E. coli endotoxin or typhoid-paratyphoid vaccine were extracted with isotonic saline. The extract was filtered through an asbestos filter and chromatographed on a Sephadex G-200 column. The fraction which was excluded at around 2.5-void volume (molecular weight, about 20,000) was significantly effective in increasing survival of animals when it was repeatedly injected in mice after x irradiation (600 R). The injection caused an increase of the weight of spleen of the animals with an increased number of endogenous spleen colonies. The result suggests that the life-saving effect of the spleen extract is based on its effect of stimulating repopulation of autochthonous hematopoietic cells in the x-irradiated animals. A similar splenic extract prepared from normal mice had an ambiguous effect on the survival of x-irradiated animals.

  11. Effect of Whole-Body X-Irradiation of the Synthesis of Individual Fatty Acids in Liver Slices from Normal and Fasted Rats

    DEFF Research Database (Denmark)

    Hansen, Heinz Johs. Max; Hansen, Lisbeth Grænge; Faber, M.

    1965-01-01

    (1) Using (2-14C) acetate and (1-14C) butyrate as precursors, rat-liver fatty acids were synthesized in vitro and assayed by paper chromatography. (2) Whole-body x-irradiation induced a change in the synthetic pattern of hepatic fatty acids towards a relatively enhanced synthesis of palmitic acid....... (3) X-irradiation and fasting seem to have opposite effects on fatty-acid synthesis. X-irradiation counteracts the drop in total synthesis and the relatively enhanced synthesis of palmitoleic acid induced by fasting. The relative enhancement of palmitic-acid synthesis mentioned under (2) stands...... in contrast to the effect of fasting, which specifically decreases the hepatic synthesis of palmitic acid. (4) There is a general similarity between corresponding fatty-acid patterns based on synthesis from (2-14C) acetate and (1-14C) butyrate, respectively....

  12. Evaluation of different biomarkers to predict individual radiosensitivity in an inter-laboratory comparison--lessons for future studies.

    Directory of Open Access Journals (Sweden)

    Burkhard Greve

    Full Text Available Radiotherapy is a powerful cure for several types of solid tumours, but its application is often limited because of severe side effects in individual patients. With the aim to find biomarkers capable of predicting normal tissue side reactions we analysed the radiation responses of cells from individual head and neck tumour and breast cancer patients of different clinical radiosensitivity in a multicentric study. Multiple parameters of cellular radiosensitivity were analysed in coded samples of peripheral blood lymphocytes (PBLs and derived lymphoblastoid cell lines (LCLs from 15 clinical radio-hypersensitive tumour patients and compared to age- and sex-matched non-radiosensitive patient controls and 15 lymphoblastoid cell lines from age- and sex- matched healthy controls of the KORA study. Experimental parameters included ionizing radiation (IR-induced cell death (AnnexinV, induction and repair of DNA strand breaks (Comet assay, induction of yH2AX foci (as a result of DNA double strand breaks, and whole genome expression analyses. Considerable inter-individual differences in IR-induced DNA strand breaks and their repair and/or cell death could be detected in primary and immortalised cells with the applied assays. The group of clinically radiosensitive patients was not unequivocally distinguishable from normal responding patients nor were individual overreacting patients in the test system unambiguously identified by two different laboratories. Thus, the in vitro test systems investigated here seem not to be appropriate for a general prediction of clinical reactions during or after radiotherapy due to the experimental variability compared to the small effect of radiation sensitivity. Genome-wide expression analysis however revealed a set of 67 marker genes which were differentially induced 6 h after in vitro-irradiation in lymphocytes from radio-hypersensitive and non-radiosensitive patients. These results warrant future validation in larger

  13. Effects of x irradiation on the postnatally-forming granule cell populations in the olfactory bulb, hippocampus, and cerebellum of the rat

    International Nuclear Information System (INIS)

    Bayer, S.A.; Altman, J.

    1975-01-01

    Beginning on the second postnatal day, either two (2X group), four (4X group) or six (6X group) daily or alternate daily exposures to low-level x irradiation (150 to 200 R) were used to interfere with the acquisition of granule cells in the olfactory bulb, hippocampus, and cerebellum of the rat. At 60 days of age, the relationship between post-irradiation recovery and permanent granule cell loss was assessed with two quantitative techniques. First, the total number of granule cells was determined to estimate the magnitude of permanent loss. Secondly, the number of labeled granule cells were counted on day 60 after a 3 H-thymidine injection given on either day 15 or on day 20 to estimate differential rates of cell proliferation during the recovery period. Permanent loss of granule cells was sustained in all regions by all schedules of irradiation. The time for the most effective exposures was earlier in the hippocampus and olfactory bulb than in the cerebellum. In all regions, both the irradiated groups and the controls showed a decrease in the level of cell proliferation between 15 and 20 days. The number of cells that could be labeled after either the 15 or 20 day injection was below control levels for all groups in the hippocampus, at control levels for all groups in the cerebellum, and either at (2X and 4X) or below (6X) control levels in the olfactory bulb. These results are discussed in the light of the formation time of the granule cells in each region

  14. Effects of x-irradiation on the postnatally-forming granule cell populations in the olfactory bulb, hippocampus, and cerebellum of the rat

    International Nuclear Information System (INIS)

    Bayer, S.A.; Altman, J.

    1975-01-01

    Beginning on the second postnatal day, either two (2X group), four (4X group) or six (6X group) daily or alternate daily exposures to low-level x irradiation (150-200 r) were used to interfere with the acquisition of granule cells in the olfactory bulb, hippocampus, and cerebellum of the rat. At 60 days of age, the relationship between post-irradiation recovery and permanent granule cell loss was assessed with two quantitative techniques. First, the total number of granule cells was determined to estimate the magnitude of permanent loss. Secondly, the number of labeled granule cells were counted on day 60 after a 3 H-thymidine injection given on either day 15 or on day 20 to estimate differential rates of cell proliferation during the recovery period. Permanent loss of granule cells was sustained in all regions by all schedules of irradiation. The time for the most effective exposures was earlier in the hippocampus and olfactory bulb than in the cerebellum. In all regions, both the irradiated groups and the controls showed a decrease in the level of cell proliferation between 15 and 20 days. The number of cells that could be labeled after either the 15 or 20 day injection was below control levels for all groups in the hippocampus, at control levels for all groups in the cerebellum, and either at (2X and 4X) or below (6X) control levels in the olfactory bulb. These results are discussed in the light of the formation time of the granule cells in each region

  15. A high frequency of induction of chromosome aberrations in the bone marrow cells of LEC strain rats by X-irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Okui, Toyo (Hokkaido Inst. of Public Health, Sapporo (Japan)); Hayashi, Masanobu; Watanabe, Tomomasa; Namioka, Shigeo (Dept. of Lab. Animal Science, Hokkaido Univ., Sapporo (Japan)); Endoh, Daiji; Sato, Fumiaki (Dept. of Radiation Biology, Faculty of Veterinary Medicine, Hokkaido Univ., Sapporo (Japan)); Kasai, Noriyuki (Inst. for Animal Experimentation, Hokkaido Univ., Sapporo (Japan))

    1994-08-01

    LEC strain rats, which have been known to develop hereditarily spontaneous fulminant hepatitis 4 to 5 months after birth, are highly sensitive to whole-body X-irradiation when compared to WKAH strain rats. The present results showed that the frequencies of all types of chromosome aberrations induced by X-irradiation in the bone marrow cells of LEC rats were approximately 2- to 3-fold higher than those of WKAH rats, though no significant difference was observed in the frequency of spontaneous chromosome aberrations between LEC and WKAH rats.

  16. Molecular events associated with increased regenerative capacity of the goldfish retinal ganglion cells following X-irradiation: decreased level of axonal growth inhibitors

    International Nuclear Information System (INIS)

    Rachailovich, I.; Schwartz, M.

    1984-01-01

    In our previous work we established conditions to study the contribution of non-neuronal cells to the process of goldfish optic nerve regeneration. This issue has been studied successfully by adapting the use of X-irradiation to manipulate division of non-neuronal cells associated with the injured nerve. The regenerative capacity of the goldfish retinal ganglion cells was determined subsequent to the X-ray treatment. The authors present an analysis of the molecular events associated with regeneration and enhanced regenerative capacity which follows X-irradiation. (Auth.)

  17. Molecular events associated with increased regenerative capacity of the goldfish retinal ganglion cells following X-irradiation: decreased level of axonal growth inhibitors

    Energy Technology Data Exchange (ETDEWEB)

    Rachailovich, I.; Schwartz, M. (Weizmann Inst. of Science, Rehovot (Israel). Dept. of Neurobiology)

    1984-07-23

    In our previous work we established conditions to study the contribution of non-neuronal cells to the process of goldfish optic nerve regeneration. This issue has been studied successfully by adapting the use of X-irradiation to manipulate division of non-neuronal cells associated with the injured nerve. The regenerative capacity of the goldfish retinal ganglion cells was determined subsequent to the X-ray treatment. The authors present an analysis of the molecular events associated with regeneration and enhanced regenerative capacity which follows X-irradiation.

  18. Lack of effect on the chromosomal non-disjunction in aged female mice after low dose x-irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Strausmanis, R; Hendrikson, I B; Holmberg, M; Roennbaeck, C [Research Inst. of National Defence, Sundbyberg (Sweden). Dept. 4

    1978-02-01

    Karyotypes were determined in 1064 embryos of aged C57/BL mothers. The virgin female mice were irradiated with 0, 4, 8 or 16 R of X-rays, respectively, and placed with young untreated males 5 days after irradiation. 10.5-days old embryos were recovered from the uterus. Aneuploid embryos classified as alive (heart beats observed at the dissection) were 1 monosomic in the control group (496 embryos) and 2 trisomics in the irradiated group (568 embryos). The number of aneuploid embryos classified as dead was 4 trisomic cases in the control group and 3 trisomics in the irradiated group. The data indicate that trisomic embryos are not uncommon in the mouse but are eliminated in post-implantation death. In contrast to the results of Yamamoto et al. the present data do not demonstrate an increased frequency of chromosome abnormalities in embryos of aged mice X-irradiated before mating as compared to non-irradiated ones.

  19. Axo-somatic synapses in the normal and X-irradiated dendate gyrus; factors affecting the density of afferent innervation

    International Nuclear Information System (INIS)

    Lee, K.S.; Gerbrandt, L.; Lynch, G.

    1982-01-01

    The density of synaptic input to the somata of dentate gyrus granule cells was examined utilizing quantitative electron microscopic techniques. In control (non-irradiated) material, greater numbers of axo-somatic synapses were observed in the superficial, earlier-generated cells as compared to the deep, later-generated cells. We further studied the X-irradiated dentate gyrus, in which the majority of granule cells were destroyed during postnatal genesis. The surviving cells displayed a density of innervation on their somata which exceeded that observed in either layer of the control material. These data are discussed in terms of the possible contribution of afferent-target cell interactions to the regulation of the density of synaptic innervation. (Auth.)

  20. Hypothyroidism after x irradiation to the neck: three case reports and a brief review of the literature

    International Nuclear Information System (INIS)

    Adler, R.A.; Corrigan, D.F.; Wartofsky, L.

    1976-01-01

    Three patients who developed hypothyroidism after x irradiation to the neck are presented. The first two cases demonstrate that patients can develop clinical and chemical hypothyroidism after a very short interval following radiotherapy. Hypothyroidism developed in the first patient in the absence of surgical manipulation of the neck, or a large iodine load 4 months after receiving 6800 rad of x-ray therapy to his neck for carcinoma of the larynx. The second patient developed hypothyroidism approximately 6 months after his radiotherapy for carcinoma of the esophagus. Both of these patients demonstrated high titers of serum antithyroid antibodies. A third patient with Hodgkin's disease did not manifest clinical symptoms and signs of hypothyroidism until 6 years after radiation therapy. These cases demonstrate the variability of onset of hypothyroidism after radiotherapy and emphasize the need for careful evaluation of thyroid function before and after neck irradiation

  1. Effects of X-irradiation alone and in combination with ACNU on human glioblastoma cells in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Mashiyama, Shoji; Katakura, Ryuichi; Takahashi, Kou; Kitahara, Masakazu; Suzuki, Jiro [Tohoku Univ., Sendai (Japan). School of Medicine; Sasaki, Takehito

    1990-05-01

    The combined effects of x-irradiation and 1-(4-amino-2-methyl-5-pyrimidinyl) methyl-3-(2-chloro-ethyl)-3-nitrosourea (ACNU) on multicellular glioblastoma A-7 spheroids were analyzed by means of cell survival and dose-response curves. The actual dose-response curve for small spheroids was almost identical to that estimated from the cell survival curve. It was strongly suggested that a small number of radiation-resistant cells, which were not detected in the cell survival curve, were present in large spheroids with central necrosis. The enhancing effect of ACNU was greater with large spheroids than with monolayer cells or small spheroids. A possible explanation for this is that ACNU is higher effective against the few radiation-resistant cells that may be present in larger spheroids. (author).

  2. Observations on the interactions of Schwann cells and astrocytes following x irradiation of neonatal rat spinal cord

    Energy Technology Data Exchange (ETDEWEB)

    Blakemore, W F; Patterson, R C

    1975-10-01

    Myelination was inhibited in the spinal cord of three day-old rats with 2000 rads of x irradiation. Myelination subsequently occurred as a result of caudal migration of oligodendrocytes and extensive invasion of the cord by Schwann cells. Although oligodendrocytes were present in areas containing Schwann cells, astrocytes were absent. The presence of Schwann cells in the neuropil of the spinal cord did not stimulate production of basement membrane by astrocytes, so no new glial limiting membrane was formed. Evidence is presented which suggests that if astrocytes do not form a glial limiting membrane when opposed by large numbers of Schwann cells they are destroyed by the invading cells. It is suggested that the glial limiting membrane normally inhibits entry of Schwann cells into the central nervous system; if this is destroyed and not reconstituted, Schwann cells can migrate freely into the neuropil.

  3. Effect of experimental immune atrophic gastritis on the induction of gastric carcinoma by x-irradiation in ICR mice

    International Nuclear Information System (INIS)

    Hirose, Fumio; Watanabe, Hiromitsu; Takeichi, Nobuo; Naito, Yukiko; Inoue, Shozo

    1976-01-01

    Divided doses of 6,000 or 8,000 rad of x-ray were given to the gastric region of ICR/JCL female mice with immune atrophic gastritis produced by the injection with allogenic stomach antigen. The carcinogenic effect of x-rays for inducing gastric carcinoma was significantly increased by this method. Two points can be presented as its reason. First, the pyloric gland mucosa regenerating from injuries by immunization was exposed to the divided doses of x-rays. Second, the marked requirement of gastrin secretion attributable to severe injuries of parietal cell mass by immunization and local x-irradiation acted as a promoting factor on the induction of gastric carcinoma by x-ray for a long time through the trophic effects on the pyloric gland. (auth.)

  4. G/sub 2/ arrest in mouse zygotes after X-irradiation: reversion by caffeine and influence of chromosome abnormalities

    Energy Technology Data Exchange (ETDEWEB)

    Grinfeld, S.; Jacquet, P.

    1988-08-01

    The effect of caffeine was studied on mouse zygotes blocked in the G/sub 2/ phase of the first cell cycle after X-irradiation. Caffeine (2 mM) effectively reversed the G/sub 2/ arrest when zygotes were incubated in its presence at the time when first mitosis normally takes place. This effect of caffeine was inhibited by cycloheximide (5 ..mu..g ml/sup -1/). In embryos escaping the G/sub 2/ arrest the frequencies of chromosome aberrations varied as a function of the time of irradiation, showing a clear relationship with the varying rates of lethality occurring from the morula stage. Blocked zygotes suffered major chromosome damage: however, this did not appear to be the only cause of the G/sub 2/ arrest. Triploid zygotes were preferentially blocked, suggesting that nuclei contain the target for this X-ray effect.

  5. Optical bleaching of F-centers in BaFCl crystals after X-irradiation at room temperature

    International Nuclear Information System (INIS)

    Inabe, K.; Nakamura, S.; Takeuchi, N.

    1988-01-01

    The optical bleaching behaviour of the F-band formed by X-irradiation in BaFCl crystals is investigated paying attention to the difference between two types of F-centers. Optical absorption spectra, decay curves of the F-band under excitation with F light and excitation spectra of the bleaching are given and discussed. The bleaching of the F-bands is achieved by light in the absorption band irrespective of the component. Energy transfer among excited states of F-centers is responsible for the bleaching of F-centers in BaFCl crystals, involving energy transfer between F(Cl - ) and F(F - ) centers in their optical bleaching process

  6. Axo-somatic synapses in the normal and X-irradiated dendate gyrus; factors affecting the density of afferent innervation

    Energy Technology Data Exchange (ETDEWEB)

    Lee, K S [Max-Planck-Institut fuer Psychiatrie, Muenchen (Germany, F.R.); Gerbrandt, L [Neuroscience Research Program, Boston, MA (USA); Lynch, G [California Univ., Irvine (USA)

    1982-10-07

    The density of synaptic input to the somata of dentate gyrus granule cells was examined utilizing quantitative electron microscopic techniques. In control (non-irradiated) material, greater numbers of axo-somatic synapses were observed in the superficial, earlier-generated cells as compared to the deep, later-generated cells. We further studied the X-irradiated dentate gyrus, in which the majority of granule cells were destroyed during postnatal genesis. The surviving cells displayed a density of innervation on their somata which exceeded that observed in either layer of the control material. These data are discussed in terms of the possible contribution of afferent-target cell interactions to the regulation of the density of synaptic innervation.

  7. The contribution of late-generated neurons to the callosal projection in rat: a study with prenatal x-irradiation

    International Nuclear Information System (INIS)

    Jensen, K.F.; Altman, J.

    1982-01-01

    Studies utilizing horseradish peroxidase tracing methods have suggested that there are species differences in the relative contribution of the different neocortical layers to the callosal projection. The present investigation utilized x-irradiation at different gestational ages to eliminate the late-generated neurons in the rat neocortex. The caudorostral gradient of reduction in the neuronal population of the supragranular layers is closely correlated with the gradient of reduction in the size of the corpus callosum. Furthermore, the callosal projection is absent in anteroposterior cortical segments in which the development of the supragranular layers was prevented without a reduction of the number of neurons in the infragranular layers of the neocortex. These results indicate that late-generated neurons residing primarily in the supragranular layers are essential for the formation of the corpus callosum

  8. Lack of effect on the chromosomal non-disjunction in aged female mice after low dose x-irradiation

    International Nuclear Information System (INIS)

    Strausmanis, R.; Hendrikson, I.-B.; Holmberg, M.; Roennbaeck, C.

    1978-01-01

    Karyotypes were determined in 1064 embryos of aged C57/BL mothers. The virgin female mice were irradiated with 0, 4, 8 or 16 R of X-rays, respectively, and placed with young untreated males 5 days after irradiation. 10.5-days old embryos were recovered from the uterus. Aneuploid embryos classified as alive (heart beats observed at the dissection) were 1 monosomic in the control group (496 embryos) and 2 trisomics in the irradiated group (568 embryos). The number of aneuploid embryos classified as dead was 4 trisomic cases in the control group and 3 trisomics in the irradiated group. The data indicate that trisomic embryos are not uncommon in the mouse but are eliminated in post-implantation death. In contrast to the results of Yamamoto et al. the present data do not demonstrate an increased frequency of chromosome abnormalities in embryos of aged mice X-irradiated before mating as compared to non-irradiated ones

  9. Effects of X-irradiation alone and in combination with ACNU on human glioblastoma cells in vitro

    International Nuclear Information System (INIS)

    Mashiyama, Shoji; Katakura, Ryuichi; Takahashi, Kou; Kitahara, Masakazu; Suzuki, Jiro; Sasaki, Takehito.

    1990-01-01

    The combined effects of x-irradiation and 1-(4-amino-2-methyl-5-pyrimidinyl) methyl-3-(2-chloro-ethyl)-3-nitrosourea (ACNU) on multicellular glioblastoma A-7 spheroids were analyzed by means of cell survival and dose-response curves. The actual dose-response curve for small spheroids was almost identical to that estimated from the cell survival curve. It was strongly suggested that a small number of radiation-resistant cells, which were not detected in the cell survival curve, were present in large spheroids with central necrosis. The enhancing effect of ACNU was greater with large spheroids than with monolayer cells or small spheroids. A possible explanation for this is that ACNU is higher effective against the few radiation-resistant cells that may be present in larger spheroids. (author)

  10. Effects of x-irradiation on steroid biotransformations by testicular tissue. Progress report, August 1, 1974--July 31, 1975

    International Nuclear Information System (INIS)

    Ellis, L.C.

    1975-01-01

    X irradiation of rat testicular tissue either in vivo or in vitro labilized the lysosomal membranes with a release of both acid phosphatase and phospholipase A 2 resulting in an increased lipid peroxidation. The results from these investigations suggest that the lipid endoperoxides and malonaldehyde are responsible for mediating the effects of radiation on steroid biotransformations. Estradiol, testosterone, 5α-dihydrotestosterone, prolactin, acetylcholine, cGMP, H 2 O 2 , PUFA, ethanol and vitamin A increased lysosomal fragility and initiated enzyme release while ATP, cAMP, vitamin E, theophylline, indomethacin, caffeine, cortisol, epinephrine, NADPH, NDGA, FSH and Zn ++ decreased both phenomena. An increase in catalase activity was consistently observed after irradiation and by cAMP indicative of an increase in testicular cAMP content following irradiation. Seminiferous tubules were found to be dependent on prostaglandins for their contractions. (U.S.)

  11. Myelin repair by Schwann cells in the regenerating goldfish visual pathway: regional patterns revealed by X-irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Nona, S.N.; Stafford, C.A.; Cronly-Dillon, J.R. (Manchester Univ. (United Kingdom). Inst. of Science and Technology); Duncan, A. (Guy' s Hospital, London (United Kingdom). Dept. of Anatomy); Scholes, J. (University Coll., London (United Kingdom))

    1994-07-01

    In the regenerating goldfish optic nerves, Schwann cells of unknown origin reliably infiltrate the lesion site forming a band of peripheral-type myelinating tissue by 1-2 months, sharply demarcated form the adjacent new CNS myelin. To investigate this effect, we have interfered with cell proliferation by locally X-irradiating the fish visual pathway 24 h after the lesion. As assayed by immunohistochemistry and EM, irradiation retards until 6 months formation of new myelin by Schwann cells at the lesion site, and virtually abolishes oligodendrocyte myelination distally, but has little or no effect on nerve fibre regrowth. Optic nerve astrocyte processes normally fail to re-infiltrate the lesion, but re-occupy it after irradiation, suggesting that they are normally excluded by early cell proliferation at this site. Moreover, scattered myelinating Schwann cells also appear in the oligodendrocyte-depleted distal optic nerve after irradiation, although only as far as the optic tract. (Author).

  12. Validation of a radiosensitivity molecular signature in breast cancer

    NARCIS (Netherlands)

    S.A. Eschrich (Steven); C. Fulp (Carl); Y. Pawitan (Yudi); J.A. Foekens (John); M. Smid (Marcel); J.W.M. Martens (John); M. Echevarria (Michelle); P.S. Kamath (Patrick); J.-H. Lee (Ji-Hyun); E.E. Harris (Eleanor); J. Bergh (Jonas); J.F. Torres-Roca (Javier)

    2012-01-01

    textabstractPurpose: Previously, we developed a radiosensitivity molecular signature [radiosensitivity index (RSI)] that was clinically validated in 3 independent datasets (rectal, esophageal, and head and neck) in 118 patients. Here, we test RSI in radiotherapy (RT)-treated breast cancer patients.

  13. Characteristics of histocompatibility barriers in congenis strains of mice. III. Passive enhancement of skin allografts in x-irradiated hosts

    International Nuclear Information System (INIS)

    Cantrell, J.L.; Kaliss, N.; Hildemann, W.H.

    1975-01-01

    Passive immunological enhancement of skin allografts was investigated in three donor-host combinations of congenic mice disparate at non-H-2 loci. Serum against the graft donor was derived from mice that had received donor strain lymphoid cells as neonates, and thereby were rendered specifically tolerant of a skin allograft. We refer to this serum as ''allograft-tolerant'' serum. Each strain combination was chosen to provide only two non-H-2 histoincompatibilities present in the donor and absent in the host. The differences are categorized as immunogenetically strong, moderate, or weak, on the basis of skin allograft survival times. With passively administered allograft-tolerant serum, significantly prolonged graft survivals were noted for the weakest combination only. Combined treatment with sublethal x-irradiation and allograft-tolerant serum significantly prolonged graft survival in both the moderate and weak combinations, with the largest effect present in the weakest disparity. A hyperimmune alloantiserum (produced in adults) directed against the graft donor prolonged allograft survival in the strongest disparity when given in combination with irradiation. In this combination, graft survival time was increased in hosts exposed to x-ray alone, but joint treatment with x-ray and the alloantiserum gave the largest increment. In contrast, combined treatment with the serum and an antithymocyte alloantiserum did not affect graft survival times. Treatment with both radiation and antithymocyte serum did not prolong graft survival beyond that in mice given only x-radiation. Immunological enhancement with central inhibition is assumed as the mechanism underlying prolonged graft survival, and it is suggested that a population of thymus-derived killer cells, sensitive to x-irradiation, is required for normal graft rejection. (U.S.)

  14. Fruit and seed characteristics of diploid seedless watermelon (citrullus lanatas) cultivars produced by soft-X-irradiated pollen

    Energy Technology Data Exchange (ETDEWEB)

    Sugiyama, Keita; Morishita, Masami [National Research Insti. of Vegetables, Ornamental Plants and Tea, Fukuoka (Japan). Kurume Branch

    2000-11-01

    We compared the differences in number of seeds, size of normal and empty seeds, and fruit quality of seedless fruit induced by soft- X- irradiated pollen to determine which cultivars are best suited for breeding and producing high quality seedless watermelon. Two wild types, eleven Japanese, one Chinese, and three American watermelon cultivars were studied. We also observed the effect of soft- X- rays on pollen germination and elongation of the pollen tube. The germination rates of pollen treated with 1000 to 2000 Gy of soft-X-ray were almost the same as those of the control, whereas the rate was significantly reduced at 3000 Gy. Soft-X- irradiated pollen germinated on a stigma, and the pollen tube elongated in the embryo sac. Watermelon fruit pollinated with pollen irradiated with 800 Gy of soft-X-ray had no normal seeds but only empty ones. To delineate the varietal differences by the number of empty seeds and seed size in seedless fruit, wild types, Japanese, Chinese, and American watermelon cultivars were investigated. The number and size of empty seeds varied among cultivars. A low correlation (r=0.272) existed between the total number of seeds in the control fruit and the number of empty seeds in the seedless fruit. Whereas, a high correlation (seed length: r=0.943, P<0.001, seed width: r=0.883, P < 0.001) was found between the size of normal seeds in control fruit and empty seeds in seedless fruit. Diploid seedless fruit was similar to control fruit in size, shape, color, rind thickness, sugar content, and days from pollination to maturity. (author)

  15. Relation between histamine release and dye permeability of pulmonary blood-air barrier in x-irradiated rat

    Energy Technology Data Exchange (ETDEWEB)

    Yamazaki, H [Kobe Univ. (Japan). School of Medicine

    1976-04-01

    The histamine-release kinetics and the influence of released histamine on the permeability of the pulmonary blood-air(BA) barrier during the early period after either whole-body or thoracic x irradiation of the rat were studied. Histamine contents of skin and lung of the irradiated rat decreased rapidly, reaching a minimum at 5 h, and this histamine depletion continued for at least 7 days. Conversely, in circulating blood histamine increased during the early period of 5 h and then decreased gradually. This early increase was linear up to 500R and then became saturated between 500 and 1,000R. Administration of polymixine B (5mg/100g body weight) to rats liberated histamine similarly. Rat sera containg histamine released soon after irradiation enhanced the capillary permeability of Evans blue(EB) in the guinea pig skin reaction, which was effectively countered by pretreatment of the guinea pig with anti-histaminic pyribenzamine (29..mu..g/100g body weight), but not by anti-serotonic chlorpromazine (0.3mg/100g body weight). Similarly, perhaps only the EB-bound serum albumin (EB-albumin), that was seen in alveolar perfusate, penetrated more through the pulmonary BA-barrier with increasing x-ray dose, in parallel with the increase in blood histamine. Pyribenzamine inhibited this effect effectively, but cysteamine (a radical scavenger) did so only partially. Thus, it seems possible that at soon after x irradiation the enhanced permeability of EB-albumin through the BA barrier of rat lung is due preferentially to the pharmacologic action of released histamine and subsidiarily to radiation damage to pulmonary cells.

  16. Fruit and seed characteristics of diploid seedless watermelon (citrullus lanatas) cultivars produced by soft-X-irradiated pollen

    International Nuclear Information System (INIS)

    Sugiyama, Keita; Morishita, Masami

    2000-01-01

    We compared the differences in number of seeds, size of normal and empty seeds, and fruit quality of seedless fruit induced by soft- X- irradiated pollen to determine which cultivars are best suited for breeding and producing high quality seedless watermelon. Two wild types, eleven Japanese, one Chinese, and three American watermelon cultivars were studied. We also observed the effect of soft- X- rays on pollen germination and elongation of the pollen tube. The germination rates of pollen treated with 1000 to 2000 Gy of soft-X-ray were almost the same as those of the control, whereas the rate was significantly reduced at 3000 Gy. Soft-X- irradiated pollen germinated on a stigma, and the pollen tube elongated in the embryo sac. Watermelon fruit pollinated with pollen irradiated with 800 Gy of soft-X-ray had no normal seeds but only empty ones. To delineate the varietal differences by the number of empty seeds and seed size in seedless fruit, wild types, Japanese, Chinese, and American watermelon cultivars were investigated. The number and size of empty seeds varied among cultivars. A low correlation (r=0.272) existed between the total number of seeds in the control fruit and the number of empty seeds in the seedless fruit. Whereas, a high correlation (seed length: r=0.943, P<0.001, seed width: r=0.883, P < 0.001) was found between the size of normal seeds in control fruit and empty seeds in seedless fruit. Diploid seedless fruit was similar to control fruit in size, shape, color, rind thickness, sugar content, and days from pollination to maturity. (author)

  17. 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)

  18. Modern concepts for basic radiobiological factors characterizing tumor tissue radiosensitivity

    International Nuclear Information System (INIS)

    Gocheva, L.; Sergieva, K.

    2002-01-01

    Traditionally radiotherapy is prescribed at doses consistent with the expected therapeutic response and tolerance of tumor and normal tissues without consideration to individual differences in radiosensitivity. However, the basic radiobiological knowledge and clinical experience along this line point to significant variations in the observed therapeutic results. It has been established that cells and tissues under experimental and clinical conditions manifest a wide spectrum of individual radiosensitivity. The aim of this survey is to outline the current concepts for the basic radiobiological factors influencing tumor radiosensitivity. A thorough discussion is done of the essence, mechanisms of action, methods of determination and measurement, and effect on the prognosis in patients with malignant diseases of a number of radiobiological factors, such as: tumor-cell proliferation, apoptosis, tumor hypoxia and neovascularization. Although the knowledge of the mechanisms of radiosensitivity is constantly expanding, its clinical implementation is still rather limited. The true role of radiosensitivity in predicting the therapeutic response should be more accurately defined. (authors)

  19. Chromosomal radiosensitivity in patients with multiple sclerosis

    International Nuclear Information System (INIS)

    Milenkova, Maria; Milanov, Ivan; Kmetska, Ksenia; Deleva, Sofia; Popova, Ljubomira; Hadjidekova, Valeria; Groudeva, Violeta; Hadjidekova, Savina; Domínguez, Inmaculada

    2013-01-01

    Highlights: • We studied radiosensitivity to in vitro γ-irradiated lymphocytes from MS patients. • Immunotherapy in RRMS patients reduced the yield of radiation induced MN. • The group of treated RRMS accounts for the low radiosensitivity in MS patients. • Spontaneous yield of MN was similar in treated and untreated RRMS patients. - Abstract: Multiple sclerosis is a clinically heterogeneous autoimmune disease leading to severe neurological disability. Although during the last years many disease-modifying agents as treatment options for multiple sclerosis have been made available, their mechanisms of action are still not fully determined. In the present study radiosensitivity in lymphocytes of patients with relapsing–remitting multiple sclerosis, secondary progressive multiple sclerosis and healthy controls was investigated. Whole blood cultures from multiple sclerosis patients and healthy controls were used to analyze the spontaneous and radiation-induced micronuclei in binucleated lymphocytes. A subgroup of patients with relapsing–remitting multiple sclerosis was treated with immunomodulatory agents, interferon β or glatiramer acetate. The secondary progressive multiple sclerosis patients group was not receiving any treatment. Our results reveal that the basal DNA damage was not different between relapsing–remitting and secondary progressive multiple sclerosis patients, and healthy controls. No differences between gamma-irradiation induced micronuclei frequencies in binucleated cells from relapsing–remitting and secondary progressive multiple sclerosis patients, and healthy controls were found either. Nevertheless, when we compared the radiation induced DNA damage in binucleated cells from healthy individuals with the whole group of patients, a reduction in the frequency of micronuclei was obtained in the patients group. Induced micronuclei yield was significantly lower in the irradiated samples from treated relapsing–remitting multiple

  20. Chromosomal radiosensitivity in patients with multiple sclerosis

    Energy Technology Data Exchange (ETDEWEB)

    Milenkova, Maria; Milanov, Ivan; Kmetska, Ksenia [III Neurological Clinic, University Hospital Saint Naum, Sofia (Bulgaria); Deleva, Sofia; Popova, Ljubomira; Hadjidekova, Valeria [Laboratory of Radiation Genetics, NCRRP, Sofia (Bulgaria); Groudeva, Violeta [Department of Diagnostic Imaging, University Hospital St. Ekaterina, Sofia (Bulgaria); Hadjidekova, Savina [Department of Medical Genetics, Medical University, Sofia (Bulgaria); Domínguez, Inmaculada, E-mail: idomin@us.es [Department of Cell Biology, Faculty of Biology, University of Seville, Avda. Reina Mercedes 6, 41012 (Spain)

    2013-09-15

    Highlights: • We studied radiosensitivity to in vitro γ-irradiated lymphocytes from MS patients. • Immunotherapy in RRMS patients reduced the yield of radiation induced MN. • The group of treated RRMS accounts for the low radiosensitivity in MS patients. • Spontaneous yield of MN was similar in treated and untreated RRMS patients. - Abstract: Multiple sclerosis is a clinically heterogeneous autoimmune disease leading to severe neurological disability. Although during the last years many disease-modifying agents as treatment options for multiple sclerosis have been made available, their mechanisms of action are still not fully determined. In the present study radiosensitivity in lymphocytes of patients with relapsing–remitting multiple sclerosis, secondary progressive multiple sclerosis and healthy controls was investigated. Whole blood cultures from multiple sclerosis patients and healthy controls were used to analyze the spontaneous and radiation-induced micronuclei in binucleated lymphocytes. A subgroup of patients with relapsing–remitting multiple sclerosis was treated with immunomodulatory agents, interferon β or glatiramer acetate. The secondary progressive multiple sclerosis patients group was not receiving any treatment. Our results reveal that the basal DNA damage was not different between relapsing–remitting and secondary progressive multiple sclerosis patients, and healthy controls. No differences between gamma-irradiation induced micronuclei frequencies in binucleated cells from relapsing–remitting and secondary progressive multiple sclerosis patients, and healthy controls were found either. Nevertheless, when we compared the radiation induced DNA damage in binucleated cells from healthy individuals with the whole group of patients, a reduction in the frequency of micronuclei was obtained in the patients group. Induced micronuclei yield was significantly lower in the irradiated samples from treated relapsing–remitting multiple

  1. Increased radiosensitivity of HPV-positive head and neck cancer cell lines due to cell cycle dysregulation and induction of apoptosis

    International Nuclear Information System (INIS)

    Arenz, Andrea; Ziemann, Frank; Wittig, Andrea; Preising, Stefanie; Engenhart-Cabillic, Rita; Mayer, Christina; Wagner, Steffen; Klussmann, Jens-Peter; Wittekindt, Claus; Dreffke, Kirstin

    2014-01-01

    Human Papillomavirus (HPV)-related head and neck squamous cell carcinoma (HNSCC) respond favourably to radiotherapy as compared to HPV-unrelated HNSCC. We investigated DNA damage response in HPV-positive and HPV-negative HNSCC cell lines aiming to identify mechanisms, which illustrate reasons for the increased sensitivity of HPV-positive cancers of the oropharynx. Radiation response including clonogenic survival, apoptosis, DNA double-strand break (DSB) repair, and cell cycle redistribution in four HPV-positive (UM-SCC-47, UM-SCC-104, 93-VU-147T, UPCI:SCC152) and four HPV-negative (UD-SCC-1, UM-SCC-6, UM-SCC-11b, UT-SCC-33) cell lines was evaluated. HPV-positive cells were more radiosensitive (mean SF2: 0.198 range: 0.22-0.18) than HPV-negative cells (mean SF2: 0.34, range: 0.45-0.27; p = 0.010). Irradiated HPV-positive cell lines progressed faster through S-phase showing a more distinct accumulation in G2/M. The abnormal cell cycle checkpoint activation was accompanied by a more pronounced increase of cell death after x-irradiation and a higher number of residual and unreleased DSBs. The enhanced responsiveness of HPV-related HNSCC to radiotherapy might be caused by a higher cellular radiosensitivity due to cell cycle dysregulation and impaired DNA DSB repair. (orig.) [de

  2. Induction of carcinomas in rat glandular stomach by direct X-irradiation of the stomach wall

    International Nuclear Information System (INIS)

    Kondratenko, A.G.; Bykorez, A.I.

    1980-01-01

    To induce carcinoma in rat stomach the direct irradiation of the organ wall with X-rays in a dose of 16.22 Gy has been used. In the period from the 8-th to the 15-th month after irradiation in mucous membrane of stomach foci of atrophy, sections of regenerating hyperplasia of glands and methaplasia of stomach gland cells in the epithelium of the intestine type have been observed. Highly differentiated adenocarcinomas growing through all the walls of stomach are found in 18.5% rats [ru

  3. Chemical radiosensitizers with special reference to metronidazole

    International Nuclear Information System (INIS)

    Sharma, R.; Purohit, O.P.; Nair, C.R.; Dutta, T.K.

    1982-01-01

    An attempt at rationalisation of drug dose schedule for a radiosensitizer in a cancer clinic is attempted. A prospective analysis of tissue tolerance, response data and complications of the two groups of patients (treated by oral and high intermittent rectal routes) was made with matched control. The study group has definite use of metronidazole. It is further highlighted that there is an additional advantage of the rectal administration route of the drug as compared to that of the oral route. This is a preliminary communication. (author)

  4. Radiosensitization of thymidine in deaerated aqueous solution

    International Nuclear Information System (INIS)

    Berger, Maurice.

    1982-09-01

    This work investigates the mode of action of various radiosensitizing agents on the radio-induced degradation of thymidine in deaerated aqueous solution. A special effort was devoted to the separation of addition products formed by one of these substances (a stable nitroxide radical: TAN) with the radio-induced neutral radicals of thymidine. The complex mixture of different diastereoisomers resulting from the covalent addition of the TAN molecule on the thymidine carbons C (5) or C (6) was resolved by HPLC. The structural determination of these adducts (absolute configuration) was achieved by various spectroscopic techniques and specific chemical syntheses. A conformational study has been undertaken [fr

  5. Analysis of mice radiosensitivity depending on age

    International Nuclear Information System (INIS)

    Bogatyrev, A.V.; Timoshenko, S.I.; Nikanorova, N.G.; Sverdlov, A.G.

    1979-01-01

    In order to elucidate mechanisms of age variations in radiosensitivity of mice a study was made of the sensitivity of in vitro irradiated bone marrow stem cells, taken from animals of different age, and postradiation recovery of leukocyte content of peripheral blood and cellularity of bone marrow and spleen. Using the method of spleen colonies similar affections were revealed in bone marrow cells of animals of different age. The degree of recovery of the hemopoietic cell pool was significantly lower in newborn mice than in adults after exposure to a dose (LDsub(50/30)) equally effective with respect to mortality

  6. Radiosensitivity study in rice (Oriza Sativa Lin.)

    International Nuclear Information System (INIS)

    Gonzalez, M.; Santana, N.; Diaz, R.

    1987-01-01

    Four rice varieties (J-104, Amistad-82, 6066 and IR-1529) were irradiated at doses of 10,15,20,25,30,35,40,45,50 and 55 Krad of gamma rays so as to determine radiosensitivity curves for each of the varieties for the following factors; seed germination percentage; survival percentage; height of the plant; length of roots. It was determined that IR-1529 variety is the one with the highest sensitivity and that radiations over 35 Krad should not be used for none of the varieties above mentioned

  7. Different radiosensitivities of mast-cell precursors in the bone marrow and skin of mice

    International Nuclear Information System (INIS)

    Kitamura, Y.; Yokoyama, M.; Sonoda, T.; Mori, K.J.

    1983-01-01

    Although tissue mast cells are derived from the bone marrow, some descendants of bone marrow-derived precursors retain the ability to proliferate and differentiate into mast cells even after localization in the skin. The purpose of the present study was to determine the D 0 values for mast-cell precursors in the bone marrow and those localized in the skin. Bone marrow cells were removed from (WB X C57BL/6)F 1 +/+ mice after various doses of irradiation and injected into the skin of the congenic W/W/sup v/ mice which were genetically without mast cells. Radiosensitivity of mast-cell precursors in the bone marrow was evaluated by determining the proportion of the injection sites at which mast cells did not appear. For the assay of the radiosensitivity of mast-cell precursors localized in the skin, pieces of skin were removed from beige C57BL/6 (bg/sup J//bg/sup J/, Chediak-Higashi syndrome) mice after various doses of irradiation and grafted onto the backs of the normal C57BL/6 mice. Radiosensitivity of mast-cell precursors in the skin was evaluated by determining the decrease of beige-type mast cells which possessed giant granules. Mast-cell precursors in the bone marrow were much more radiosenitive than those localized in the skin. D 0 value was about 100 rad for the former and about 800 rad for the latter

  8. Thermal sensitivity and thermally enhanced radiosensitivity of murine bone marrow granulocyte-macrophage colony-forming units (CFU-GM)

    International Nuclear Information System (INIS)

    Yoshida, Hiroshi

    1994-01-01

    This study was to evaluate thermal response of granulocyte-macrophage colony-forming unit (CFU-GM) in vitro and to investigate the difference of thermally enhanced radiosensitivity on cell survivals of CFU-GM between in vitro and in vivo. In in vitro heating exposure, bone marrow suspensions, obtained from mouse femora or tibiae, were incubated; and in vivo heating exposure, the lower half-body of mice were immersed in a circulating hot water bath. For irradiation schedules, cell suspensions were irradiated in vitro or in vivo (whole-body irradiation). Thermal sensitivity curve, obtained by in vivo heating exposure, showed a shoulder region at short exposures followed by an exponential decline during longer heating exposures. The Arrhenius curve showed a break at 42.3deg C and inactivation enthalpy was 1836 kJ/mol (438 kcal/mole) below the break point and 704 kJ/mole (168 kcal/mole) above the point. When bone marrow suspensions, obtained after either in vitro or in vivo irradiation, were heated in vitro at 42deg C for 60 min, supura-additive effect on cell survivals was observed by in vivo irradiation, but not observed by in vitro irradiation. Thermal enhancement ratio (TER), defined as D 0 of combined in vivo irradiation and in vitro heating divided by D 0 of the sole in vivo irradiation, was 1.12. In vivo heating following in vivo irradiation also showed supra-additive effect, giving TER of 1.66. These findings indicated that murine marrow CFU-GM is sensitive to hyperthermia and that thermal radiosensitization is never negligible when hyperthermia is employed with preceding X-irradiation. Thus, combined use of radiotherapy and hyperthermia may decrease bone marrow function. (N.K.)

  9. The toxic effects, GSH depletion and radiosensitivity by BSO on retinoblastoma

    International Nuclear Information System (INIS)

    Xianjin Yi; Li Ding; Yizun Jin; Chuo Ni; Wenji Wang

    1994-01-01

    Retinoblastoma is the most common intraocular malignant tumor in children. Previous investigations have reported that buthionine sulfoximine (BSO) can deplete intracellular glutathione (GSH) by specific inhibition and increase cellular radiosensitivity. The toxic effects, GSH depletion and radiosensitivity effects of BSO on retinoblastoma cells are reported in this paper. GSH content of retinoblastoma cell lines Y-79, So-Rb50 and retinoblastoma xenograft is 2.7 ± 1.3 X 1.0 -12 mmol/cell, 1.4 ± 0.2 X 1.0 -12 mmol/cell, and 2.8 ± 1.2 μmol/g, respectively. The ID 50 of BSO on Y-79 and So-Rb50 in air for 3 h exposure is 2.5 mM and 0.2 mM, respectively. GSH depletion by 0.1 mM BSO for 24 h on Y-79 cells and 0.01 mM BSO for 24 h on So-Rb50 cells is 16.35%, and 4.7% of control. GSH depletion in tumor and other organ tissues in retinoblastoma-bearing nude mice after BSO administration is differential. GSH depletion after BSO exposure in Y-79 cells in vitro decreases the Do value of retinoblastoma cells. The SER of 0.01 mM and 0.05 mM BSO for 24 h under hypoxic conditions is 1.21 and 1.36, respectively. Based on these observations, the authors conclude that BSO toxicity on retinoblastoma cells depends on the characteristics of the cell line and that BSO can increase hypoxic retinoblastoma cells' radiosensitivity in vitro. Further study of BSO radiosensitization on retinoblastoma in vivo using nude mouse xenografts is needed. 25 refs., 3 figs., 3 tabs

  10. The toxic effects, GSH depletion and radiosensitivity by BSO on retinoblastoma

    International Nuclear Information System (INIS)

    Yi Xianjin; Ni Chuo; Wang Wengi; Li Ding; Jin Yizun

    1993-01-01

    Retinoblastoma is the most common intraocular malignant tumor in children. Previous investigations have reported that buthionine sulfoximine (BSO) can deplete intracellular glutathione (GSH) by the specific inhibition and increase cellular radiosensitivity. The toxic effects, GSH depletion and radiosensitivity of BSO on retinoblastoma were reported. GSH content of retinoblastoma cell lines Y-79, So-Rb50 and retinoblastoma xenograft is (2.7 +- 1.3) x 10 -12 mmol/cell, (1.4 +- 0.2) x 10 -12 mmol/cell, and 2.8 +- 1.2 μmol/g respectively. The ID50 of BSO on Y-79 and So-Rb50 in air for 3h exposure is 2.5 mM and 0.2 mM respectively. GSH depletion by 0.1 mM BSO for 24h on Y-79 cells and 0.01 mM BSO for 24 h on So-Rb50 cells is 16.35%, and 4.7% of control. GSH depletion in tumor and other organ tissues in retinoblastoma bearing nude mice after BSO administration is differential. BSH depletion after BSO exposure in Y-79 cells in vitro decrease the D 0 value of retinoblastoma cells. The SER of 0.01 mM and 0.05 mM BSO for 24 h under the hypoxic condition is 1.21 and 1.36 respectively. Based on these observations, the authors conclude that BSO toxicity on retinoblastoma cells depends on the characteristics of cell line and BSO can increase hypoxic retinoblastoma cells radiosensitivity in vitro. Further study of BSO radiosensitization on retinoblastoma in vivo using nude mouse xenograft is needed

  11. Spontaneous and x-irradiation induced carcinomas of small intestine in Wistar-Furth rats

    Energy Technology Data Exchange (ETDEWEB)

    Maeura, Y; Kosaki, G; Kitamura, H [Osaka Univ. (Japan). Faculty of Medicine; Nagatomo, T

    1980-04-01

    Spontaneous carcinoma of the small intestine in Wistar-Furth (WF) rats and carcinoma of the small intestine induced by local x-ray irradiation to the abdomen of WF rats without carcinoma were observed, and x-ray sensitivity of the small intestine mucosa was reported. Out of 19 rats with spontaneous carcinoma of the small intestine, 18 also had carcinoma of the colon, and 4 also had gastric cancer. They already had spontaneous carcinoma of the small intestine within 2 weeks after their birth, and the ratio of female and male was 13 : 6. Histological type of this carcinoma in all 19 rats was highly differentiated adenocarcinoma, and small intestine epithelium around carcinoma presented atypical epithelium. As to mice without carcinoma, x-ray, 1,000 R, 1,500 R, and 2,000 R, was irradiated to the abdomen of Sprague-Dawley (SD) and WF rats. In the irradiation with 1,000 R, carcinogenesis was not found in rats of both strains. In the irradiation with 1,500 R, carcinogenesis was hardly found, but in the irradiation with 2,000 R, carcinoma of small intestine occurred in 5 of 17 rats 15 weeks after the irradiation, 9 of 19 rats 25 weeks after the irradiation, and 9 of 14 rats 35 weeks after the irradiation. Histological type of carcinoma in irradiated rats was highly differentiated adenocarcinoma. The incidence of carcinoma in irradiated rats was higher in WF rats than SD rats through the course after the irradiation, which suggested that x-ray sensitivity of WF rats was higher than that of SD rats. Therefore, carcinoma of the small intestine in irradiated mice seemed to be induced by x-ray.

  12. Evaluation of nitrobenzimidazoles as hypoxic cell radiosensitizers

    International Nuclear Information System (INIS)

    Wright, J.; Frank, L.R.; Bush, D.; Harrison, G.H.

    1983-01-01

    Radiobiological and pharmacokinetic assays were performed to determine the potential of 2-nitrobenzimidazole (NBI) as a hypoxic cell radiosensitizing agent. As judged by comparing survival curve slopes of Serratia marcescens irradiated under aerated and hypoxic conditions, the NBI enhancement ratio (ER) at 2 mM concentration was 2.4 +- 0.2, compared with an oxygen enhancement ratio of 3.3 +- 0.3. 2,5-Dinitrobenzimidazole (DNBI) was investigated in vitro; its ER was 3.0 +- 0.3 at 4 mM concentration. Very poor tissue penetration of DNBI precluded further testing in vivo. Acute toxic signs appeared in C3H/HeJ mice following ip injection of NBI at 100 mg/kg. These would be partly attributable to the stress caused by the high pH of the injection vehicle. The LD 50 was estimated to be 125 to 150 mg/kg. Mammary adenocarcinoma tumors grown in the flanks of these mice exhibited maximum NBI levels at 5 min postinjection (ip). Peak tumor radiosensitization occurred in the interval between 5 and 10 min postinjection. The ER for tumor regrowth delay was 2.1 +- 0.3 following 50 mg/kg injected into mice 5 min before irradiation. Functional evaluation up to 40 days after treatment revealed no evidence of neurological deficit

  13. Evaluation of nitrobenzimidazoles as hypoxic cell radiosensitizers

    International Nuclear Information System (INIS)

    Wright, J.; Frank, L.R.; Bush, D.; Harrison, G.H.

    1983-01-01

    Radiobiological and pharmacokinetic assays were performed to determine the potential of 2-nitrobenzimidazole (NBI) as a hypoxic cell radiosensitizing agent. As judged by comparing survival curve slopes of Serratia marcescens irradiated under aerated and hypoxic conditions, the NBI enhancement ratio (ER) at 2 mM concentration was 2.4 +/- 0.2, compared with an oxygen enhancement ratio of 3.3 +/- 0.3. 2,5-Dinitrobenzimidazole (DNBI) was investigated in vitro; its ER was 3.0 +/- 0.3 at 4 mM concentration. Very poor tissue penetration of DNBI precluded further testing in vivo. Acute toxic signs appeared in C3H/HeJ mice following ip injection of NBI at 100 mg/kg. These would be partly attributable to the stress caused by the high pH of the injection vehicle. The LD50 was estimated to be 125-150 mg/kg. Mammary adenocarcinoma tumors grown in the flanks of these mice exhibited maximum NBI levels at 5 min postinjection (ip). Peak tumor radiosensitization occurred in the interval between 5 and 10 min postinjection. The ER for tumor regrowth delay was 2.1 +/- 0.3 following 50 mg/kg injected into mice 5 min before irradiation. Functional evaluation up to 40 days after treatment revealed no evidence of neurological deficit

  14. Mechanisms of oxygen radiosensitization in CHO cells

    International Nuclear Information System (INIS)

    Whillans, D.W.

    1981-01-01

    A model is presented for repair and fixation pathways when CHO cells are irradiated in the presence of O 2 . This analysis predicts that an increase in the repair path such as has been postulated for addition of a radioprotective sulfhydryl should increase OER/sub max/ in porportion to k prime, the new repair rate constant and also increase K with k prime. Any radiosensitizer which mimics the action of O 2 simply increases k prime 2 , so that the OER/sub max/ decreases at 1/k prime 2 but K increases as k prime 2 . These predictions have been tested in mammalian CHO cells making use of a Clark-type oxygen probe with defined conditions to ensure that O 2 is not depleted by radiation or cellular consumption, and so O 2 levels are known with accuracy. In a complementary study, the technique of rapid-mixing was used to measure the rate of development of O 2 sensitization in these same cells. By a variation of this rapid-mixing approach, the rate of diffusion into these cells has also been measured independently. Neither the dependence of OER on O 2 concentration nor the development of radiosensitivity with time of incubation in O 2 gives evidence in CHO cells for two components of sensitization indicative of two sites or two mechanisms of action, as seen in some V79 sublines. 13 references, 4 figures

  15. Molecular mechanism of radiosensitization by nitro compounds

    International Nuclear Information System (INIS)

    Kagiya, T.; Wada, T.; Nishimoto, S.I.

    1984-01-01

    In this chapter a molecular mechanism of radiosensitization by electron-affinic nitro compounds is discussed, mainly on the basis of the results of the radiation-induced chemical studies of DNA-related compounds in aqueous solutions. In Section II the general aspects of the radiation chemistry of organic compounds in the absence and presence of oxygen in aqueous solution are shown in order to demonstrate characteristic differences between radiation chemical reactions in hypoxic and oxic cells. The effects of nitro compounds on the radiolysis yields of DNA-related compounds in aqueous solutions are described in Section III. In Section IV the retardation effects of misonidazole on the radiation chemical processes of DNA-related compounds are shown along with the reaction characteristics of misonidazole with hydroxyl radical ( . OH) and hydrated electron (e/sub aq/-bar) produced by the radiolysis of water. The promotion of radiation-induced oxidation of thymine into thymine glycol (TG) by nitro radiosensitizers in deoxygenated solution and the relations between the activity of nitro compound for the thymine glycol formation and the enhancement activity measured in vitro are described in Section V. Finally, the protection against radiation-induced damage of thymine by a sulfhydryl compound of glutathione and the ability of electron-affinic compounds to decompose the intracellular radioprotector are described in Section VI

  16. Sequence-dependent toxicity and small bowel mucosal injury in neonatal mice treated with low doses of 5-azacytidine and X-irradiation at the late organogenesis stage

    International Nuclear Information System (INIS)

    Schmahl, W.

    1983-01-01

    A combined treatment of pregnant mice on day 12 of gestation with both azacytidine and X-irradiation in low doses induces sequence-dependent histological effects. These effects, in turn, induce different symptomatic signs if evaluated either prenatally or neonatally. In the azacytidine treatment/X-irradiation sequence the malformations of the fetal forebrain are predominant. Consequently, these dams show a high incidence in the stillbirth rate. Conversely, the X-irradiation/azacytidine treatment schedule leads only to a mild brain hypoplasia, and does not cause an increased stillbirth rate. In these offspring, however, a severe impairment of small bowel epithelial proliferation capacity was found. This is linked to an outstanding neonatal mortality within 48 h after birth. The pathogenesis of these sequence-dependent effects can be attributed to a selective vulnerability of cells in different stages of the generation cycle. This comprises a high degree of cytolethality affecting the S/G 2 -stage cells in azacytidine/X-irradiation treatment and the G 1 /S-stage cells in the reverse combinations (Schmahl 1979). The present observations show the validity of a teratological assay in providing a detailed analysis of the cell kinetic responses after combined noxious influences. (orig.)

  17. Effects of x-irradiation induced loss of cerebellar granule cells on the synaptosomal levels and the high affinity uptake of amino acids

    International Nuclear Information System (INIS)

    Rohde, B.H.; Rea, M.A.; Simon, J.R.; McBride, W.J.

    1979-01-01

    Crude synaptosomal (P 2 ) preparations were obtained from the cerebella of rats in which the granule cell population had been selectively reduced by X-irradiation treatment and from the cerebella of control animals. In the P 2 fraction form control cerebella, the level of glutamate was greater than any other of the 5 amino acids measured and was 2-fold higher than taurine. The content of taurine, GABA, glycine, and alanine were not changed by the X-irradiation treatment. The uptake of 1.0 micrometers-L-[ 3 H]glutamate and L-[ 3 H]aspartate was reduced approx 20% by X-irradiation treatment, whereas the uptake of 1.0 micrometers-[ 3 H]GABA and [ 3 H]taurine was unchanged. In a second study, the uptake of L-[ 3 H]glutamate, L-[ 3 H]aspartate and [ 3 H]GABA was measured using P 2 fractions obtained from the cerebella of rats in which the population of granule, stellate and basket cells had been reduced by X-irradiation treatment. The uptake of 1.0 micrometers-L-[ 3 H]glutamate, L-[ 3 H]aspartate and [ 3 H]GABA was significantly (P < 0.05) reduced to 57.68 and 59% respectively, of control values. The data are discussed in terms of glutamate being the excitatory neurotransmitter released from granule cells and GABA being the inhibitory neurotransmitter released from basket cells. (author)

  18. Synergistic induction of tumors in NMRI mice by combined fetal X-irradiation with low doses and ethylnitrosourea administered to juvenile offspring

    Energy Technology Data Exchange (ETDEWEB)

    Schmahl, W.

    1988-08-01

    Mice were X-irradiated on day 15 of gestation with 0.2, 0.4, 0.8 or 1.6 Gy. Offspring were reared by their mothers and divided into two subgroups at an age of 21 days, one subgroup receiving a single dose (45 mg/kg) of ethylnitrosourea (ENU). All animals were kept ultimately until 22 months to register the long-term tumor pattern. The carcinogenic effects of ENU alone were also studied in two separate experiments. Prenatal X-irradiation with 1.6 Gy mostly abolished the carcinogenic late effects of ENU, with the exception of an almost constant leucosis incidence and an unchanged lung tumor frequency. Lowering the prenatal X-ray dose to 0.8 Gy resulted in a significantly increased rate of liver tumors and ovary tumors. Synergistic effects on various tissues were observed after both 0.4- and 0.2-Gy fetal X-irradiation treatment in combination with postnatal application of ENU. These effects mainly involved a significant increase in the frequency of leucosis and of tumors of the liver, intestine, uterus and ovaries. The greater-than-additive effect in the case of these tumors suggests that low-level prenatal X-irradiation leads to a lasting sensitivity of some tissues towards a subsequent carcinogenic stimulus.

  19. Low-level x-irradiation of the brain during development: morphological, physiological, and behavioral consequences. Progress report, September 1, 1974--August 31, 1975

    International Nuclear Information System (INIS)

    Altman, J.

    1975-01-01

    Progress is reported on studies on the effects of exposure to low-dose x radiation on the developing brain of rats. Brief summaries of results of morphological, physiological, and behavioral studies on rats exposed using various x-irradiation schedules are included. A list of papers published and submitted for publication during the period is included. (U.S.)

  20. Quercetin suppresses DNA double-strand break repair and enhances the radiosensitivity of human ovarian cancer cells via p53-dependent endoplasmic reticulum stress pathway

    Directory of Open Access Journals (Sweden)

    Gong C

    2017-12-01

    Full Text Available Cheng Gong,1 Zongyuan Yang,1 Lingyun Zhang,2 Yuehua Wang,2 Wei Gong,2 Yi Liu3 1Department of Obstetrics and Gynecology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 2Department of Oncology, XiangYang Central Hospital, Hubei University of Arts and Science, XiangYang, 3Department of Medicinal Chemistry, School of Pharmacy, Hubei University of Chinese Medicine, Wuhan, China Abstract: Quercetin is proven to have anticancer effects for many cancers. However, the role of tumor suppressor p53 on quercetin’s radiosensitization and regulation of endoplasmic reticulum (ER stress response in this process remains obscure. Here, quercetin exposure resulted in ER stress, prolonged DNA repair, and the expression of p53 protein; phosphorylation on serine 15 and 20 increased in combination with X-irradiation. Quercetin pretreatment could potentiate radiation-induced cell death. The combination of irradiation and quercetin treatment aggravated DNA damages and caused typical apoptotic cell death; as well the expression of Bax and p21 elevated and the expression of Bcl-2 decreased. Knocking down of p53 could reverse all the above effects under quercetin in combination with radiation. In addition, quercetin-induced radiosensitization was through stimulation of ATM phosphorylation. In human ovarian cancer xenograft model, combined treatment of quercetin and radiation significantly restrained the growth of tumors, accompanied with the activation of p53, CCAAT/enhancer-binding protein homologous protein, and γ-H2AX. Overall, these results indicated that quercetin acted as a promising radiosensitizer through p53-dependent ER stress signals. Keywords: quercetin, p53, endoplasmic reticulum stress, DNA double-strand breaks, eIF-2α (eukaryotic initiation factor 2α, ATM kinase

  1. Enhancement of in vivo Radiosensitization by Combination with Pentoxifylline and Nicotinamide

    International Nuclear Information System (INIS)

    Lee, In Tae; Cho, Moon June

    1991-01-01

    Pentoxifylline (PENTO) has been known to improve RBC fluidity, and thus improve the flux of RBC through narrow capillaries. Additionally, PENTO also decreases the O2 release from RBC. Nicotinamide (N4) has been reported to decrease the number of acutely hypoxic cells in tumors by temporarily increasing tumor blood flow. Therefore, the purpose of this study was to examine whether the combination of PENTO and NA (PENTO+NA) would reduce the radioresistance of the the FSa II murine fibrosarcoma by oxygenation the hypoxic cells. We observed a significantly enhanced radiation-induced growth delay of the FSa II tumors by PENTO-NA. Thus the enhancement ration was between 2.5 and 2.8 in growth delay assay. The TCD 50 of control tumors was about 57 Gy, but that of PENTO-NA treated tumors was about 32 Gy. The TCD50 was modified by a factor of 1.8. We also observed that PENTO+NA, changes in tumor blood flow and intratumor pO2 were measured using laser Doppler flowmetry and O2 microelectrode methods. The tumor blood flow significantly increased at 10 min. after injection of PENTO+NA. Furthermore, we also found that PENTO+NA significantly increased intratumor pO2 from 8 to 19 mmHg. We concluded that PENTO+NA was far more effective than NA alone or PENTO alone. The increase in the response of tumor in vivo to X-irradiation appeared to be due mainly to an increase in the tumor oxygenation. Further studies using various concentrations of PENTO alone and in combination with NA to obtain better sequencing and maximal radiosensitization are warranted

  2. Determination of the oxygen enhancement ratio (OER) of human colon tumor cells in vitro after chronic exposure to the differentiation-inducing agents n-methylformamide (NMF) and sodium butyrate (NAB)

    International Nuclear Information System (INIS)

    Hallows, K.; Bliven, S.; Leith, J.T.

    1987-01-01

    The authors previously showed that both rodent and human tumor cells in either exponentially growing or plateau phase cultures can be sensitized to X-irradiation by chronic exposure to NMF or NAB. This effect is particularly evident in the low dose region of the survival curve as noted by a significant increase in the term of the linear-quadratic equation or by a significant decrease in the D/sub q/ value using single-hit, multitarget nomenclature. However, these agents are operationally distinct, as these changes are accompanied by inhibition of sublethal damage recovery (SLDR) after NAB treatment, while no effect on SLDR is seen with NMF treatment. As they think that the use of differentiation-inducing agent such as NMF or NAB may be useful in combining modality therapy of solid tumors, the authors extended their previous studies to note if any change in the OER accompanying this observed radiosensitization of oxic cells could be found. Tumor cells were grown in either 170mM NMF or 2 mM NAB and were irradiated with 250 kVp x-rays. Data is presented

  3. Expression of IL-1β mRNA in mice after whole body X-irradiation

    International Nuclear Information System (INIS)

    Nemoto, Kumie; Ishihara, Hiroshi; Tanaka, Izumi; Suzuki, Gen; Tsuneoka, Kazuko; Yoshida, Kazuko; Ohtsu, Hiroshi

    1995-01-01

    IL-1β is a stimulator of hematopoietic and inflammatory systems, and also acts as a radioprotector. After whole-body exposure to sublethal doses of ionizing radiation, the IL-1β mRNA level in spleen cells increases for a short time prior to regeneration of the spleen. We analyzed spleen cells of C3H/He mice after whole-body irradiation with 3 Gy x-rays to determine the cause of this short-term increase in the transcription level. An increase in the level of the message in spleen cells, found by Northern blot hybridization, reached its peak 5 to 7 days after irradiation. There was a low correlation between the curves of the mRNA level and the ratio of monocyte/macrophage lineage cells; a typical source of the message. Spleen macrophages that produce a large amount of the message were found 7 days after irradiation in an in situ hybridization experiment in which heterogeneous spleen cell populations were used. In contrast, spleen cells had no detectable levels of macrophages rich in IL-1β mRNA before and 17 days after irradiation. Additionally, the population of message-rich cells was 9.4% of the total number of monocytes/macrophages in the spleen. These results suggest that the short-term increase in IL-1β mRNA is a result of the heterogeneous differentiation of a subpopulation of spleen macrophages before regeneration of the spleen. (author)

  4. Quantitative changes in the cellularity of the rat subependymal plate after X-irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Hubbard, B; Hopewell, J W [Oxford Univ. (UK). Churchill Hospital Research Institute

    1980-07-01

    The brains of young adult rats were irradiated with a single dose of 8 Gy (800 rad) of 250 kVp X-rays. Within 2 weeks of treatment the cell population of the subependymal plate was reduced by 30%. During this period the cell cycle time remained unchanged but the labelling index was reduced. The cell population subsequently returned to normal after 39-52 weeks. Damage and subsequent recovery of the plate was due mainly to changes in the number of cells with small dark nuclei. Cells with small and large light nuclei were little affected. A model for the production and differentiation of cells in the subependymal region is proposed on the basis of age-related changes in the total number and proportions of the various cell types in the subependymal plate of normal rats. This is discussed both in terms of the radiation response of cells in the plate and the manifestation of delayed white matter necrosis after higher doses.

  5. Immunization against Capillaria hepatica: The effects of primary infections, X-irradiated stages, non-embryonated eggs and soluble egg extracts

    Energy Technology Data Exchange (ETDEWEB)

    Zahner, H.; Schmidt, H.; Laemmler, G.; Geyer, E.

    1980-01-01

    The worm reproductivity was significantly suppressed in a sublethal challenge infection given 11 days after a primary infection of Mastomys natalensis with 50, 150, 400, and 800 eggs per animal. The administration of 600 X-irradiated (2.2 Krd) embryonated eggs 36 days before challenge as well as an intraperitoneal injection of non-embryonated eggs 12, 10, 8, 6, 4, and 2 days before challenge also reduced significantly the egg production of a weak (50 eggs/animal) infection. No effect was observed on a moderate challenge (300 eggs/animal). The effect was not markedly enhanced by the repeated administration of X-irradiated eggs or by the combination of X-irradiated infective eggs and non-embryonated eggs. Immunization of mice with soluble egg extracts resulted in significant reduction of egg production determined 60 days after challenge. Two hundred and thirty eggs of C. hepatica/g bodyweight proved to be a lethal infection dose for M. natalensis. The animals died between 20 and 35 days after infection. After single infections with 50, 150, 400, or 800 eggs per animal the mortality of Mastomys challenged 36 or 52 days later was reduced to 0-30%. Using X-irradiated embryonated eggs for immunization only repeated administration led to protection in 70 to 80%, of the animals. About 40% of the animals could be protected by the intraperitoneal injection of non-embryonated eggs. If death occurred it was delayed. The combination of X-irradiated stages and eggs did not enhance the protection.

  6. Inductive potential of recombinant human granulocyte colony-stimulating factor to mature neutrophils from X-irradiated human peripheral blood hematopoietic progenitor cells

    International Nuclear Information System (INIS)

    Katsumori, Takeo; Yoshino, Hironori; Hayashi, Masako; Takahashi, Kenji; Kashiwakura, Ikuo

    2009-01-01

    Recombinant human granulocyte colony-stimulating factor (rhG-CSF) has been used for treatment of neutropenia. Filgrastim, Nartograstim, and Lenograstim are clinically available in Japan. However, the differences in potential benefit for radiation-induced disorder between these types of rhG-CSFs remain unknown. Therefore, the effects of three different types of rhG-CSFs on granulocyte progenitor cells and expansion of neutrophils from nonirradiated or 2 Gy X-irradiated human CD34 + hematopoietic progenitor cells were examined. For analysis of granulocyte colony-forming units (CFU-G) and a surviving fraction of CFU-G, nonirradiated or X-irradiated CD34 + cells were cultured in methylcellulose containing rhG-CSF. These cells were cultured in serum-free medium supplemented with rhG-CSF, and the expansion and characteristics of neutrophils were analyzed. All three types of rhG-CSFs increased the number of CFU-G in a dose-dependent manner; however, Lenograstim is superior to others because of CFU-G-derived colony formation at relatively low doses. The surviving fraction of CFU-G was independent of the types of rhG-CSFs. Expansion of neutrophils by rhG-CSF was largely attenuated by X-irradiation, though no significant difference in neutrophil number was observed between the three types of rhG-CSFs under both nonirradiation and X-irradiation conditions. In terms of functional characteristics of neutrophils, Lenograstim-induced neutrophils produced high levels of reactive oxygen species compared to Filgrastim, when rhG-CSF was applied to nonirradiated CD34 + cells. In conclusion, different types of rhG-CSFs lead to different effects when rhG-CSF is applied to nonirradiated CD34 + cells, though Filgrastim, Nartograstim, and Lenograstim show equal effects on X-irradiated CD34 + cells. (author)

  7. Treatment Combining X-Irradiation and a Ribonucleoside Anticancer Drug, TAS106, Effectively Suppresses the Growth of Tumor Cells Transplanted in Mice

    International Nuclear Information System (INIS)

    Yasui, Hironobu; Inanami, Osamu; Asanuma, Taketoshi; Iizuka, Daisuke; Nakajima, Takayuki; Kon, Yasuhiro; Matsuda, Akira; Kuwabara, Mikinori

    2007-01-01

    Purpose: To examine the in vivo antitumor efficacy of X-irradiation combined with administration of a ribonucleoside anticancer drug, 1-(3-C-ethynyl-β-D-ribo-pentofuranosyl)cytosine (TAS106, ECyd), to tumor cell-transplanted mice. Methods and Materials: Colon26 murine rectum adenocarcinoma cells and MKN45 human gastric adenocarcinoma cells were inoculated into the footpad in BALB/c mice and severe combined immunodeficient mice, respectively. They were treated with a relatively low dose of X-irradiation (2 Gy) and low amounts of TAS106 (0.1 mg/kg and 0.5 mg/kg). The tumor growth was monitored by measuring the tumor volume from Day 5 to Day 16 for Colon26 and from Day 7 to Day 20 for MKN45. Histologic analyses for proliferative and apoptotic cells in the tumors were performed using Ki-67 immunohistochemical and terminal deoxynucleotidyl transferase-mediated nick end labeling staining. The expression of survivin, a key molecule related to tumor survival, was assessed by quantitative polymerase chain reaction and immunohistochemical analysis. Results: When X-irradiation and TAS106 treatment were combined, significant inhibition of tumor growth was observed in both types of tumors compared with mice treated with X-irradiation or TAS106 alone. Marked inhibition of tumor growth was observed in half of the mice that received the combined treatment three times at 2-day intervals. Parallel to these phenomena, the suppression of survivin expression and appearance of Ki-67-negative and apoptotic cells were observed. Conclusions: X-irradiation and TAS106 effectively suppress tumor growth in mice. The inhibition of survivin expression by TAS106 is thought to mainly contribute to the suppression of the tumor growth

  8. Quantification of 5-hydroxytryptamine[sub 1A] receptors in the cerebellum of normal and x-irradiated rats during postnatal development

    Energy Technology Data Exchange (ETDEWEB)

    Matthiessen, L; Daval, G; Bailly, Y [Pierre et Marie Curie Univ., Paris (France). Centre National de la Recherche Scientifique, UA; Gozlan, H; Hamon, M; Verge, D [INSERM, Paris (France). Lab. de Neurobiologie Cellulaire et Fonctionnelle

    1992-11-01

    5-Hydroxytryptamine[sub 1A] receptors were studied in rats during the first postnatal month in the normal cerebellum and in the granule cell-deprived cerebellum produced by X-irradiation at postnatal day 5. Quantitative autoradiographic studies on sagittal sections of cerebellar vermis, using [[sup 125]1]BH-8-MeO-N-PAT as radioligand or specific anti-receptor antibodies, revealed that 5-hydroxytryptamine[sub 1A] receptors existed in the molecular/Purkinje cell layer but at variable density from one lobule to another. Thus, in both normal and X-irradiated rats, the posterior lobules were more heavily labelled than the anterior ones, and the density of 5-hydroxytryptamine[sub 1A] sites decreased progressively in all the cerebellar folia down to hardly detectable levels at postnatal day 21. However, the intensity of labelling remained higher at postnatal day 8 and postnatal day 12 in X-irradiated rats than in age-paired controls. Measurements of [[sup 3]H]8-OH-DPAT [8-hydroxy-2-(di-n-propylamino)tetralin] specific binding to membranes from whole cerebellum confirmed that the density of 5-hydroxytryptamine[sub 1A] sites per mg membrane protein (B[sub max]) was higher in X-irradiated animals than in age-paired controls. However, on a ''per cerebellum'' basis, no significant difference could be detected between the total number of 5-hydroxytryptamine[sub 1A] sites, which progressively increased in both control and X-irradiated animals during the first postnatal month. These results therefore show that 5-hydroxytryptamine[sub 1A] receptors are not located on developing granule cells. (author).

  9. Marked radiosensitization of cells in culture to x ray by 5-chlorodeoxycytidine coadministered with tetrahydrouridine, and inhibitors of pyrimidine biosynthesis

    International Nuclear Information System (INIS)

    Perez, L.M.; Mekras, J.A.; Briggle, T.V.; Greer, S.

    1984-01-01

    The authors approach to overcome the problem of rapid catabolism and general toxicity encountered with 5-halogenated analogues of deoxyuridine (5-bromo, chloro or iododeoxyuridine), which has limited their use as tumor radiosensitizers, is to utilize 5-chlorodeoxycytidine (CldC) with tetrahydrouridine (H 4 U). They propose that CldC, coadministered with H 4 U, is metabolized in the following manner: CldC → CldCMP → CldUMP → → CldUTP → DNA. All the enzymes of this pathway are elevated in many human malignant tumors and in HEp-2 cells. In x irradiation studies with HEp-2 cells, limited to 1 or 2 radiation doses. They obtained 3.0 to 3.8 apparent dose enhancement ratios when cells were preincubated with inhibitors of pyrimidine biosynthesis. Enzymatic studies indicate that this toxicity may be tumor selective. Preliminary toxicity studies indicate that mice will tolerate treatment protocols with marginal weight loss (4%). In this approach the authors seek to obtain preferential conversion of CldC to CldUTP at the tumor site by taking advantage of quantitative differences in enzyme levels between tumors and normal tissues

  10. The development of genes associated with radiosensitivity of cervical cancer

    International Nuclear Information System (INIS)

    Li Hongyan; Chen Zhihua; He Guifang

    2007-01-01

    It has a good application prospect to predict effects of radiotherapy by examining radiosensitivity of patients with cervical cancers before their radiotherapy. Prediction of tumor cell radiosensitivity according to their level of gene expression and gene therapy to reverse radio-resistance prior to radiation on cervical cancers are heated researches on tumor therapy. The expression of some proliferation-related genes, apoptosis-related genes and hypoxia-related genes can inerease the radiosensitivity of cervical cancer. Microarray technology may have more direct applications to the study of biological pathway contributing to radiation resistance and may lead to development of alternative treatment modalities. (authors)

  11. Prenatal deaths and external malformations caused by x-irradiation during the preimplantation period of ddy mice

    International Nuclear Information System (INIS)

    Ro, Hee Jeong; Choi, Ihl Bhong; Gu, Yeun Wha

    1998-01-01

    To evaluate the effects of x-irradiation on prenatal deaths, i.e., preimplantation deaths. embryonic deaths, and fetal deaths, and on external malformations in precompacted preimplantation ddy mice. Pregnant mice (n=85), obtained by limiting the mating time to from 6 to 9 A.M., were segregated into 11 groups, The first five groups (n=26) were irradiated with X-ray doses of 0.1, 0.5, 0.75, 1.5, and 3 Gy, respectively, at 24 h post conception (p.c.) of the preimplantation period. The second five (n=27) groups were irradiated at the same X-ray doses, respectively, but at 48 h p.c. of the preimplantation period. The last group (n=32) was the control group. The uterine contents were examined on the 18th day of gestation for prenatal deaths and external malformations. 1) A statistically significant increase in preimplantation deaths with increasing dose was observed in the experimental groups irradiated at 24 h p.c. and in the groups irradiated at 48 h p.c., as compared to the control group. The threshold dose was close to 0.05 Gy and 0.075 Gy for the irradiations at 24 h p.c. and 48 h p.c. respectively. 2) A statistically significant increase in embryonic deaths with increasing dose was observed in all irradiation groups, except the group irradiated with a dose of 0,1 Gy at 48 h p.c.. 3) No fetal deaths were found in any experimental group. 4) In the experimental groups irradiated at 24 h p.c., anomalies increased with statistical significance, as compared with the control group: 2 exencephalies, 2 open eyelids,' 3 anophthalmias, 2 cleft palates. 2 gastroschisis, 1 abdominal wall defect. 1 leg defect, and 2 short tail anomalies; the threshold dose for external malformations was close to 0.2 Gy at 24 h p.c.. In the groups irradiated at 48 h p.c., 1 open eyelid and 2 short tail anomalies were observed, but there was no statistical significance in those malformations. The results of this study reveal that x-irradiation of precompacted preimplantation ddy mice causes not

  12. Characterization of an organ-specific differentiator substance

    International Nuclear Information System (INIS)

    Steele, V.E.

    1975-01-01

    Cell regeneration in planaria (Dugesia etrusca) was studied. An attempt was made to characterize a diffusible brain inhibitory substance, to elucidate its role in the maintenance of anterior-posterior polarity during head or tail regeneration, and to utilize its action in measuring the differentiative integrity of the stem cells following x-irradiation. (U.S.)

  13. Clinical experience with the radiosensitizer misonidazole

    International Nuclear Information System (INIS)

    Kogelnik, D.; Szepesi, T.; Kaercher, K.H.; Seitz, W.

    1979-01-01

    From April 1976 to June 1978, 74 cancer patients were treated with multiple doses of misonidazole at the University Clinic for Radiotherapy and Radiobiology of Vienna. Thirtyone patients had inoperable brain tumors or high-grade astrocytomas, the remaining patients suffered from late stages of various extracerebral malignancies. All patients were hospitalized and thoroughly examined for possible side-effects of this currently most promising hypoxic cell radiosensitizer. Neurotoxicity, principally the development of peripheral neuropathies, is the most important limiting factor in the clinical application of misonidazole. With total doses of 12 g/m 2 of surface area a low and acceptable incidence of neuropathies is seen. By extension of the over-all treatment time to 6-8 weeks the total dose may be increased to 15 g/m 2 . (orig.) 891 MG/orig. 892 RDG [de

  14. Radiosensitivity of cultured insect cells: II. Diptera

    International Nuclear Information System (INIS)

    Koval, T.M.

    1983-01-01

    The radiosensitivity of five dipteran cell lines representing three mosquito genera and one fruit fly genus were examined. These lines are: (1) ATC-10, Aedes aegypti; (2) RU-TAE-14, Toxorhynchites amboinensis; (3) RU-ASE-2A, Anopheles stephensi; (4) WR69-DM-1, Drosophila melanogaster; and (5) WR69-DM-2, Drosophila melanogaster. Population doubling times for these lines range from approximately 16 to 48 hr. Diploid chromosome numbers are six for the mosquito cells and eight for the fruit fly cells D 0 values are 5.1 and 6.5 Gy for the Drosophila cell lines and 3.6, 6.2, and 10.2 Gy for the mosquito cell lines. The results of this study demonstrate that dipteran insect cells are a few times more resistant to radiation than mammalian cells, but not nearly as radioresistant as lepidopteran cells

  15. High incidence of acute myeloid leukemia in SJL/J mice after X-irradiation and corticosteroids

    International Nuclear Information System (INIS)

    Resnitzky, P.; Estrov, Z.; Hebrew Univ., Jerusalem; Haran-Ghera, N.

    1985-01-01

    SJL/J mice which developed a high incidence of spontaneous reticulum cell neoplasms, developed a low rate incidence (20-25%) of myeloid leukemia (ML) after X-irradiation. The possible effect of adrenal steroid imbalance to radiation-induced ML in SJL/J mice was tested. Intact and thymectomized animals were exposed to a single dose of 300 r whole body irradiation and treated with either hydrocortisone acetate, prednisone, metyrapone and adrenocorticotropin as coleukemogenic agents. Hydrocortisone and prednisone exerted a marked coleukemogenic effect, increasing the ML incidence to a similar rate of about 50-70%, at a mean latent period of 300 days. Prominent leukemic infiltration were observed in the bone marrow, spleen, lymph nodes and liver of the leukemic animals. Results of cytological and histological studies, including cytochemistry and ultrastructure, were all consistent with the diagnosis of acute myeloid leukemia (AML). Since AML is the type of human secondary leukemia which appears increasingly in patients treat with alkylating drugs and/or irradiation and corticosteroids for Hodgkin's disease or other neoplastic diseases, the experimental model of AML induced in SJL/J mice could be used for elucidation of mechanisms of leukemogenesis in secondary leukemia. (author)

  16. High incidence of acute myeloid leukemia in SJL/J mice after X-irradiation and corticosteroids

    Energy Technology Data Exchange (ETDEWEB)

    Resnitzky, P; Estrov, Z; Haran-Ghera, N

    1985-01-01

    SJL/J mice which developed a high incidence of spontaneous reticulum cell neoplasms, developed a low rate incidence (20-25%) of myeloid leukemia (ML) after X-irradiation. The possible effect of adrenal steroid imbalance to radiation-induced ML in SJL/J mice was tested. Intact and thymectomized animals were exposed to a single dose of 300 r whole body irradiation and treated with either hydrocortisone acetate, prednisone, metyrapone and adrenocorticotropin as coleukemogenic agents. Hydrocortisone and prednisone exerted a marked coleukemogenic effect, increasing the ML incidence to a similar rate of about 50-70%, at a mean latent period of 300 days. Prominent leukemic infiltration were observed in the bone marrow, spleen, lymph nodes and liver of the leukemic animals. Results of cytological and histological studies, including cytochemistry and ultrastructure, were all consistent with the diagnosis of acute myeloid leukemia (AML). Since AML is the type of human secondary leukemia which appears increasingly in patients treat with alkylating drugs and/or irradiation and corticosteroids for Hodgkin's disease or other neoplastic diseases, the experimental model of AML induced in SJL/J mice could be used for elucidation of mechanisms of leukemogenesis in secondary leukemia.

  17. Induction and repair of DNA base damage studied in X-irradiated CHO cells using the M. luteus extract

    International Nuclear Information System (INIS)

    Foehe, C.; Dikomey, E.

    1994-01-01

    DNA base damage was measured in Chinese hamster ovary cells X-irradiated under aerobic conditions using an extract of the bacterium Micrococcus luteus. The glycosylases and endonucleases present in this extract recognize damaged bases and convert them into strand breaks (termed endonuclease-sensitive sites, enss). Strand breaks were detected by the alkaline unwinding technique. The induction of enss was measured for X-ray doses ranging up to 45 Gy. The relative frequency of all enss related to all radiation induced strand breaks was 1.7 ± 0.4. Repair of enss was studied for a radiation dose of 45 Gy. The number of enss was found to decrease exponentially with time after irradiation with a half-time of τ enss = 37 ± 8 min. The repair kinetics that were also measured for all X-ray-induced DNA strand breaks were found to consist of three phases: fast, intermediate and slow. The intermediate phase was fitted under the assumption that this phase results from the information and repair of secondary single-strand breaks generated by enzymatic incision at the sites of base damage repair. (author)

  18. Molecular and genetic approach to understanding the mechanisms by which fractionated X-irradiation induces leukemia in mice

    Energy Technology Data Exchange (ETDEWEB)

    Meruelo, D; Rossomando, A

    1986-01-01

    The authors laboratory's approach to try to shed light on the question of a viral etiology for radiation-induced leukemia has focused on defining, localizing and understanding the mode of action of genes involved in susceptibility to fractionated x-irradiation-(FXI) induced disease. These studies have indicated that multiple genes control the process of leukemogenesis. Not every mouse strain which shows some susceptibility to FXI-induced leukemia carries the susceptible gene at each of the multiple loci involved in the disease process. It is plausible to conclude that more than one mechanism of leukemogenesis can be triggered by FXI. Studies have focused on the mode of action of one such locus Ril-1. Several reagents have been developed to help clone and characterize this locus. Currently chromosomal ''walking'' and ''hopping'' techniques are being used in conjunction with an RFLP molecular probe which is adjacent to Ril-1. In addition a cDNA library has been prepared from a radiation-induced thymoma and substraction hybridization analysis is being used in the search for Ril-1.

  19. Long-term effect of whole-body X-irradiation on cell-mediated immune reaction in mice

    International Nuclear Information System (INIS)

    Norimura, Toshiyuki; Tsuchiya, Takehiko

    1989-01-01

    Age-related change in immunological activity was examined at 10 to 91 weeks following whole-body irradiation by determining the specific anti-tumor cell-mediated immunity in host mice induced and/or enhanced by local irradiation to transplanted tumor. Median survival time of the non-irradiated C3H/He female mice was 98.6 weeks while the median life-span of the mice exposed to two and four Gy of 250 kVp X-rays at the age of 10-12 weeks was shortened by 14.9 and 23.4 weeks, respectively. The rate of tumor reduction within two weeks after local irradiation to tumor and the growth inhibitory activitiy of spleen cells from tumor irradiated mice were reduced in a dose-dependent manner when assessed 10 weeks after whole-body irradiation, but recovered to the near-complete level of the non-irradiated controls within a few months, then gradually decreased with normal aging. These results suggest that the age-dependent decline of this immunological activity apears earlier in the irradiated mice as a result of whole-body X-irradiation at a young age, suggesting accelerated aging of the immune system. (author)

  20. A longitudinal analysis of regional brain volumes in macaques exposed to X-irradiation in early gestation.

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    Kristina Aldridge

    Full Text Available Early gestation represents a period of vulnerability to environmental insult that has been associated with adult psychiatric disease. However, little is known about how prenatal perturbation translates into adult brain dysfunction. Here, we use a longitudinal study design to examine the effects of disruption of early gestational neurogenesis on brain volume in the non-human primate.Five Rhesus macaques were exposed to x-irradiation in early gestation (E30-E41, and four control monkeys were sham-irradiated at comparable ages. Whole brain magnetic resonance imaging was performed at 6 months, 12 months, and 3 and 5 years of age. Volumes of whole cerebrum, cortical gray matter, caudate, putamen, and thalamus were estimated using semi-automated segmentation methods and high dimensional brain mapping. Volume reductions spanning all ages were observed in irradiated monkeys in the putamen (15-24%, p = 0.01 and in cortical gray matter (6-15%, p = 0.01. Upon covarying for whole cerebral volume, group differences were reduced to trend levels (putamen: p = 0.07; cortical gray matter: p = 0.08. No group-by-age effects were significant.Due to the small number of observations, the conclusions drawn from this study must be viewed as tentative. Early gestational irradiation may result in non-uniform reduction of gray matter, mainly affecting the putamen and cerebral cortex. This may be relevant to understanding how early prenatal environmental insult could lead to brain morphological differences in neurodevelopmental diseases.