We investigated mutations induced by gamma-rays in major organogenesis using New HITEC mice, which have rpsL gene as a reporter for mutation detection. The pregnant mice were exposed to 2 Gy of gamma-rays on day 9.5 of gestation. On day 18.5 of gestation, fetuses were removed by cesarean operation, and forelimb, hindlimb and tail were extracted and the mutation frequencies were analyzed. The mutation frequencies in forelimb, hindlimb and tail of the irradiated group increased about 2 times compared with the control group. In contrast, after irradiation, most fetuses had tail anomaly, but there were very few fetuses had malformations of forelimb and hindlimb. The relationship between radiation-induced malformation and mutation was not recognized. [J Radiat Res 44:419 (2003)]

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To examine the transgenerational mutations by ionising radiation in human, microsatellite length polymorphic mutations have been investigated in the F1 offspring of the liquidators who worked for the Chernobyl accident. Sixty four exposed families (liquidators living in Minsk after the accident) and 67 unexposed families living in Minsk were examined. DNA were extracted from the peripheral lymphocytes (father, mother and children) and used for amplifying microsatellites by PCR. Mutations were detected using automated sequencer with Gene Scan program. Five and four mutations were found in the 61 (69 F1) exposed and 23 (25 F1) unexposed families, respectively, using 15 microsatellites linked with X- and autosomes. Only one mutation was found at two Y linked microsatellites among 39 exposed families (42 sons) and none were found in 13 unexposed families (13 sons). Significant differences are not found between exposed and unexposed groups at present. [J Radiat Res 44:420 (2003)]

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The primary feature of the environmental impact by the JCO criticality accident was that neutrons were the main contributor of its radiological consequences. We continue the efforts to reconstruct the behavior of neutrons in the environment around the JCO facilities, using three dimensional Monte Carlo transport codes (MORSE, MCNP) and two dimensional Sn transport code (DOT3.5). The geometry inside the JCO territory was modeled with a cluster of 8 buildings including the Uranium Conversion Testing Building (UCTB) where the criticality accident took place. Neutron dose and neutron-induced activities (Co58, Cr51, Co60 etc.) have been calculated around the JCO territory and compared with measured values. So far, we succeeded in reconstructing neutron doses at 13 monitoring points along the JCO territory (70 - 540 m from UCTB) within the maximum deviation of 40% from measurements. Self-shielding of sampled materials and shielding effects of houses are being calculated using forward-adjoint coupling technique. We will evaluate neutron spectrum and neutron dose inside houses. [J Radiat Res 44:420 (2003)]

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An X-ray contrast medium, Thorotrast, composed of Th-232, developed liver cancers including cholangiocarcinoma, angiosarcoma after intravascular injections. Also, alpha-particle induced liver cancers were observed in workers engaged in nuclear weapon production at Mayak establishment in Russia. We compared pathology of the liver tumors, particularly angiosarcoma, between Thorotrast patients and Mayak workers. Numbers, mean ages, gender (F:M), mean latency, liver dose (or activity) and external irradiation of angiosarcoma cases (Thorotrast/Mayak) were 56/10, 57.4/62.4yr, 7:49/8:2, 62.4/57.4yr, 8.26Gy/273nCi, 0/2.57Gy, respectively. Histological features were (1) no remarkable difference in histology between the two; (2) relevant lesions such as dysplasia and foamy Kupffer cell aggregation were seen surrounding main tumors in both; (3) Thorotrast granules and liver cirrhosis were found only in Thorotrast cases. These three characters are explained by different routes and size of alpha-emitters. We conclude angiosarcoma is an index tumor of alpha-particle irradiation to liver. [J Radiat Res 44:420 (2003)]

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It is well known that numerous cave dwellings are widely distributed in Chinese loess plateau. In order to prevent an interference by this thoron presence to radon measurements, a simple discriminative passive monitor was newly developed and then was introduced to the survey program of the Chinese loess plateau. As a result, high concentrations of indoor thoron over 200 Bq/m3 were observed. Comparing with such gas concentrations, equilibrium equivalent thoron concentrations, EETC, were found to be not so high. It suggests that equilibrium factor is fairly low, comparing with the conservative expectation in the UNSCEAR 2000 report. Effective doses due to radon and thoron were estimated, respectively. As the contribution of thoron to an effective dose is large, importance of the radon and thoron discriminative measurement is reconfirmed. [J Radiat Res 44:420 (2003)]

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Reactive oxygen species (ROS) give rise to various types of oxidative damage and some responses such as activation of stress responsive transcription and/or repair factors in cells. Proteome analysis using 2D-PAGE and peptide mass fingerprinting is suitable for the study on the post-translational modifications of proteins. When glial cells were exposed to hydroperoxide, the relative abundance of 9 spots changed on 2D gels, as compared with control gels. MALDI-TOF MS analysis after in-gel digestion revealed that these spots corresponded to at least 3 pairs of proteins. These pairs of protein spots had different isoelectric points each other and were identified as peroxiredoxin II, peroxiredoxin III and calpactin. It was suggested that peroxiredoxin II, peroxiredoxin III and calpactin were changed to their modified forms of a different isoelectric point by hydroperoxide. In the present work, we studied also the variant expressions of proteins caused by irradiation, and will discuss the effects of oxidative stress on proteins in the presentation. [J Radiat Res 44:421 (2003)]

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Activation of MEK/ERK pathway generally results in stimulation of cell growth and confers a survival adavantage. The potential involvement of this pathway in cellular radiosensitivity, however, still remains unclear. The purpose of this study was to examine whether ERK pathway affects intrinsic radiosensitivity in mammalian cells. In order to inhibit MEK/ERK pathway, a MEK inhibitor, PD98059 was employed. When rat 3Y1 cells were treated with PD98059, at a concentration of 25uM, ionizing radiation-induced ERK activation at 6 Gy was almost completely inhibited. Cell growth was significantly suppressed even at 1uM. PD98059 treatment unexpectedly induced clonogenic radioresistance in a dose-dependent manner. Similar effect was observed by expression of kinase-deficient MEK, confirming the effect induced by PD98059 treatment. Radiation-induced apoptotic activity was significantly reduced in cells PD98059-treated cells as evaluated by PARP cleavage. The present study serves as a reminder that therapeutic interventions established based upon a general view could conversely work in certain conditions; characterization of individual tumors and a careful consideration are required. [J Radiat Res 44:421 (2003)]

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p53 protein is a stress-responsive molecule that is accumulated and activated by X-irradiation and induces a cell cycle arrest or apoptosis. It has been thought that p53 is accumulated by the inhibition of the interaction between p53 and its specific ubiquitin ligase MDM2 caused by the phosphorylation of p53 at Ser15, Thr18, or Ser20. However, the physiological significance of the phosphorylation of each site remains elusive. Therefore, in the present study, we aimed at elucidateing a role of the phosphorylation on X-ray-induced p53 accumulation. First, we constructed ecdyson-inducible vectors containing the mutant p53 gene in which Ser15, Thr18, and Ser20 were substituted by alanine. Then, these vectors were stably transfected into HT1080. The expression of Ala mutant p53 was induced by ponasterone A (PA). In response to 4 Gy of X-rays, every PA-induced mutant p53 protein was accumulated, although the basal levels and the degree of accumulation were slightly different among the clones. These results indicate that other major mechanism than the inhibition of p53-MDM2 binding can be involved in p53 accumulation. [J Radiat Res 44:421 (2003)]

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To understand the molecular mechanism of base damages by Auger effect on oxygen and nitrogen atom in DNA molecule, guanine radicals have been studied using a newly developed an EPR spectrometer installed in a soft X-ray beamline in SPring-8. This system enables us to irradiate monochromatic ultrasoft X-rays to a sample and observe radicals induced simultaneously. The unique character of this apparatus revealed the induction of unstable short-lived radicals in guanine pellet sample irradiated in a vacuum at 77 K. The EPR spectrum was clearly distinguished from that of stable one which still exists after exposing to ultrasoft X-rays. Thus, we conclude that 1) short-lived species are mainly induced by as a result of the final state of the resonant Auger process on solely existing oxygen atom in carbonyl group in guanine, 2) Auger events at the other atoms in guanine, namely carbon and nitrogen, do not induce this radical process significantly, even though the abundant of these atoms is dominant in guanine molecule. [J Radiat Res 44:421-422 (2003)]

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Pyrococccus horikoshii OT3 (OT3) is the anaerobic hyperthermophilic archaeon, whose genome analysis has been completed. Instead of normal SOD/catalase system, this strain possesses unusual scavenging system for O₂⁻and H₂O₂ due to Superoxide reductase/ Peroxideredoxin, in which O₂ is not generated as a byproduct. Thymine glycol (Tg) is a well-known oxidative base lesion, which blocks DNA replication. The endonuclease III (Nth) has been isolated and characterized from various aerobes as a repair enzyme for Tg. To understand repair mechanism for oxidative base lesions in OT3, we search homologues in the database, and found a candidate for Nth homologue. To clarify whether this candidate is functional, we cloned the gene, purified OT3-Nth, and measured the enzymatic activity by using nicking assay with dsDNAs containing various oxidative lesions including Tg. The OT3-Nth was able to release these lesions by glycosylase activity and also cleave backbone producing 3'-OH at AP site by AP lyase activity. These results strongly suggest that OT3-Nth is the Nth homologue in Pyrococccus horikoshii OT3. [J Radiat Res 44:422 (2003)]

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It is known that superoxide anions (O₂⁻), one of reactive oxygen species (ROS), which damage cells, cause by electron leakage from the mitochondrial electron transport system as a major endogenous source. To further explore the relation between overproduction of O₂⁻ and cellular damage, we established a transgenic cell line with a point mutation in the cytochrome b large subunit (SDHC) of complex II, which overproduces intercellular (O₂⁻).As expected, this increased O₂⁻ induces many apoptosis during cultivation of the cells. Interestingly, many survivors of apoptosis were transformed at higher frequencies compared to non-transgenic cell line. Oxidative stress results in damage to mitochondria as well as other cellular components, and thereby may lead to apoptosis. In addition to it, oxidative stress causes mutations in DNA and leads to cancer. These data support that oxidative stress from mitochondria plays an important role in apoptosis, which leads to precocious aging and carcinogenesis. [J Radiat Res 44:422 (2003)]

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Available evidence suggests that insulin-like growth factor I receptor (IGF-IR) expression leads to increased cellular radioresistance via downstream survival signals. However, expression of a membrane-targeted C-terminal fragment of IGF-IR has been reported to send a signal strongly and ultimately lead to cell death; this pro-death signal is not suppressed by survival signals from IGF-IR. We sought to explore the ability of the C-terminus of intact IGF-IR to become activated and lead to the abrogation of IGF-IR-mediated radioresistance. In the present study, we show evidence that IGF-IR-mediated radioresistance could be abrogated by mutations at tyrosine residues 1250 and 1251 in the C-terminus. This effect is presumably through activation of the C-terminal cell killing effect in IGF-IR because the essential domain for the effect was also required for the abrogation of radioresistance and the activation of downstream survival signaling pathways are still maintained. [J Radiat Res 44:422 (2003)]

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Transcriptional activity of p53-target genes is enhanced by irradiation with a low-dose of ionizing radiation. However the detailed mechanisms for promoter activation by radiation are not elucidated. One of the reasons is that a reporter vector responsive to radiation has not been developed. We here show that a luciferase gene-based reporter plasmid, containing the p21 gene promoter, weakly but significantly responds to 0.5Gy of X rays in MCF-7 cells. We also show that the response of the construct to X rays is not enhanced by introducing the 3'UTR of the p21 gene at the 3'end of the luciferase gene, indicating that the 3'UTR of the p21 gene does not function in stabilization of mRNA in response to radiation. In addition we show that expression of phRL-TK vector, which is generally used as a transfection efficiency control, is reduced after irradiation, suggesting that the phRL-TK is inadequate as a control vector in the study of transcriptional regulation by radiation. We speculate that a radiation-inducible Egr-1 may block association of Sp1 to the TK promoter in phRL-TK. [J Radiat Res 44:422-423 (2003)]

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PURPOSE: HB-EGF is synthesized as a membrane-anchored form (proHB-EGF) and proHB-EGF is cleaved on the cell surface to yield soluble HB-EGF by the mechanism called "ectodomain shedding". The aim of this study is to determine whether various stress induce ectodomain shedding of proHB-EGF. MATERIALS AND METHODS: Vero-H cells were cultured for 15h in serum free MEM-NEAA, then treated with anisomycin, sorbitol, or H₂O₂. For UV and X-ray irradiation, Vero-H were exposed to 40 mJ UV using a Spectrolinker and 1 Gy using X-ray generator, respectively. Following incubation for 30 min with stimili, the cells were collected and shedding was detected by western blot analysis. RESULT: An inhibitor of p38 MAPK inhibited the stress-induced ectodomain shedding of proHB-EGF. The stress induced shedding was inhibited neither by the inhibitor of TPA- or LPA- induced shedding , nor by dn forms of molecules involved in TPA- or LPA- induced proHB-EGF shedding pathway. [J Radiat Res 44:423 (2003)]

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ATM kinase plays a crucial role in the initiation of signaling pathways in mammalian cells following exposure to IR and other DNA DSB-inducing agents. Loss of function in this protein causes the human disease Ataxia-telangiectasia (AT), characterized by sensitivity to IR, genetic instability, cancer predisposition, and neurodegeneration. Since the only known function of ATM is that of a serine-threonine kinase, we analyzed the subset of phosphorylated proteins in wild-type and ATM-deficient cells using a combination of ³²P labeling, selective visualization of phosphorylated proteins in 2DE gels using a phosphoprotein-specific stain (Pro-Q Diamond) and MALDI-TOF mass spectrometry. Using this approach, we were able to generate 2DE phosphoproteome profiles of ATM-deficient cells during DSB-induction. By comparing 2DE profiles of these cells with that from wild-type cells, we were able to identify novel proteins that exhibited differential phosphorylation states in these two cell lines. The possible relation of these putative novel proteins to AT is discussed. [J Radiat Res 44:423 (2003)]

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Histone H3 is phosphorylated during the late G2 and mitosis. The phosphorylation is required for proper chromosome condensation and segregation. The mammalian Aurora B kinase, AIM-1, is responsible for the phosphorylation of H3 histone. When cells are exposed to ionizing radiation (IR), the mitotic phosphorylation of histone H3 is transiently suppressed with dependency of the irradiation doses. Here, we have shown that the regulation of AIM-1 kinase activity is involved in this radiation-induced signal transduction pathway. The repression of the kinase activity induced by IR is independent of functions of either ATM and TP53, upstream checkpoint regulators for Cdc2 kinase during G2 phase. A kinase-negative AIM-1 suppresses the mitotic phosphorylation of histone H3 without Cdc2 inactivation. Thus, the appearance of IR-induced G2 arrest is likely as a result of a mixture of these checkpoint signals. [J Radiat Res 44:423 (2003)]

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Phosphorylation of p53 by ATM and ATR is important for its stabilization and activation. We investigated the effects of caffeine and wortmannin, the protein kinase inhibitors of both ATM and ATR, and ATM, respectively, on S-phase DNA checkpoint in mouse zygote fertilized with irradiated sperm. DNA synthesis was measured by labeling with 3H-labeled thymidine. S-phase suppression in irradiated-sperm mouse zygote was abrogated by caffeine, and also by wortmannin. These results suggest that the suppression of DNA synthesis was dependent on ATM. Next, we tried to explore whether p53 suppresses DNA synthesis via some down stream target gene. A transcriptional inhibitor, had no effect on the suppression. p53 mutants, which lack the ability to bind DNA, were unable to suppress DNA synthesis in irradiated-sperm mouse zygote. In addition, p21-/- zygotes exhibited the same level of suppression upon fertilization by irradiated sperm. Therefore, the supprerrion is dependent on the DNA binding function of p53, but not on the transactivation function. [J Radiat Res 44:423-424 (2003)]

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We have previously reported that the mRNA of heme oxygenase-1 (HO-1) gene in the liver was increased transiently by an X-ray irradiation of the rat. HO-1 is a stress-responsive gene with a cytoprotective function. In the present work we have examined the effectiveness of several natural compounds with redox activities upon the activation of HO-1 gene in a mouse macrophage-like cell line, RAW 264.7. Cells were cultured in a 35-mm dish. DMEM medium with FCS was changed to DMEM without FCS which was supplimented with various natural compounds. 4 hrs. later, total RNA preparations were obtained. The level of HO-1 mRNA was measured with an RT-PCR system. In the cells treated with caffeic acid phenethylester for 4 hrs. the level of mRNA of HO-1 was enhanced remarkably as much as the extent of stimulation by diethylmaleate, a typical inducer of HO-1 gene. However, no or little stimulation were detected with EGCG, resveratrol or ellagic acid. [J Radiat Res 44:424 (2003)]

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In radiotherapy, it use to single and combination of radiation and chemotherapy by side effect becomes have a most problem. In this study, chaga and propolis investigated anti-oxidation action, SOD-activity, immunization activation activity and anti-cancer effect. Furthermore, we reviewed reduction of side effect by radiation protection in combination with radiotherapy. The rate that a patient is saved will be highest without lowering immunization action of a patient by putting these and an immunization effect with if a treatment is pushed forward. We think that which is an effective ingredient of flavonoids, beta-1,3D-glucan and alkaloid. Therefore, the immunization reinforcement action, anti-oxidation action, anti-inflammatory action and an indirectly anti-cancer effect were provided by self-healing power. In addition, we think that altefirin C and tritelpenoid was effects by anti-cancer material of a propolis having a high anti-cancer effect of chaga acts on a direct tumor and an anti-cancer effect was provided. [J Radiat Res 44:424 (2003)]

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We investigated the effect of epidermal growth factor(EGF), melatonin, and edaravone on the radiation intestinal injury. C3H/He female mice were X-irradiated to the whole body at the total dose of 15,17,19, or 18 Gy. Mice were administered subcutaneously with EGF or melatonin after irradiation. Edaravone was administered intrapeitoneally before irradiation or after irradiation. Small intestine of the mice was removed at 3.5 day after irradiation and stained with haematoxylin and eosin. The numbers of regenerating crypts ware measured. The survival ratio of crypts per circumference was calculated. There was no difference between EGF or melatonin, administering group and the control group in the survival ratio. However, The survival ratio of edaravone, administered mice was significantly higher than that of the control group when mice were administered with edaravone 1 hour before irradiation. The result indicated that the premedication of edaravone protected the intestinal injury caused by the radiation. [J Radiat Res 44:424 (2003)]

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Purpose: To examine effects of hypoxia and doranidazole on apoptotic signaling pathway.Materials and methods: Immediately after human leukemia cell line MOLT-4 cells were exposed to X rays of 15 Gy under the normoxic condition at ice-cold temperature, cells were incubated under the hypoxic condition without or with doranidazole. Apoptotic cell death, phosphorylation of SAPK/JNK, expression of Fas, activation of caspase-3 and intracellular glutathione concentration [GSH]i were measured by morphological observation, Western blotting and fluorometric assay, respectively. Results: Induction of radiation-induced apoptosis was lowered by post-irradiation incubation of cells under the hypoxic condition. Suppression of radiation-induced phosphorylation of SAPK/JNK, expression of Fas and activation of caspase-3 was also observed. However, the presence of doranidazole under the hypoxic condition not only suppressed the induction of apoptosis but also restored the SAPK/JNK/Fas/caspase-3 signaling. The recovery of decreased [GSH]i was also observed under these conditions. Conclusion: These results suggested that hypoxia and doranidazole altered the apoptotic signaling pathway through intracellular redox condition. [J Radiat Res 44:424-425 (2003)]

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Hsp90 plays a key role in the stability and function of many cell-signaling molecules. We examined the effects of Hsp90 inhibitor, 17-allylamino-17-demethoxygeldanamycin (17AAG), on radiosensitivity and signal transduction pathways in human tumor cell lines. 17AAG, a less toxic derivative of geldanamycin, radiosensitized both SQ-5 and DLD-1 derived from lung carcinoma and colon adnocarcinoma, respectively. It also sensitized other squamous cell carcinoma cells. 17AAG inhibited protein expression of ErbB-2 and also reduced the expression of Akt and phosphorylated Akt (pAkt) expression in squamous cell carcinoma cells. Akt is thought to mediate namy biological actions toward anti-apoptotic responce. Inhibiting activation of Akt by 17AAG caused increase of apoptosis in squamous cell carcinoma cells. These findings suggest that 17AAG enhances the radiation sensitivity of human tumor cells by inhibiting PI3K-Akt signaling pathway. Hsp90 inhibitor should be a potent therapeutic drug that can enhance the clinical effectiveness of radiation upon radioresistant tumor cells. [J Radiat Res 44:425 (2003)]

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We have investigated the radio-protective effect of melatonin on mice. Melatonin was dissolved with Soybean oil. Then ICR (male, 7 week) mice were given a peritoneal injection of melatonin (250mg/kg/0.2ml) or only soybean oil as control one hour before whole body irradiation. Radioprotection by melatonin was evaluated by calculating LD50/30. The LD50/30 for melatonin for X-rays was 8.25 Gy for melatonin injection group and 7.25 Gy for control group, respectively. This result suggests that melatonin effectively protect mice from X-irradiation. The same experiment is under way using 13keV/micron and 50 keV/micron carbon beams. [J Radiat Res 44:425 (2003)]

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We observed a change in the amount of drug uptake into the tumor tissues, tumor growth, and a cell survival rate by using mild-hyperthermia combined with chemotherapy in vivo and in vitro. As a result,the amounts of drug uptake to the tumor were increased with in vivo, and tumor growth rate were decreased, a cell survival rate were decreased in vitro study.Therefore, these results suggested that mild-hyperthermia combined with chemotherapy were increase the tumor damages due to the uptake of drugs,because of increase of blood flow in tumor tissue.Also these results predicted the elevated QOL and decrease of metastasis after mild-hyperthermia combined with chemotherapy. [J Radiat Res 44:425 (2003)]

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Objective: To examine the possibility of NO radical generators as thermo-chemo-sensitizers using human tumors bearing the wild-type or mutant p53 gene. Materials & Methods: We used transplanted tumors of human non-small lung cancer H1299 cells (p53-null) transfected with neo, wild-type or mutant p53 expression vector, H1299/neo, H1299/wtp53 or H1299/mp53 cells, respectively, in nude mice. We used Isosorbide Dinitrate as an NO radical generator. We examined the potentiation of hyperthermia-induced tumor regrowth delay by the NO radical generator. Results: We found that Isosorbide Dinitrate potentiated the hyperthermia-induced tumor regrowth delay in a p53-indepedndent manner. It is suggested that NO radical generators may be useful for the thermo-chemo-therapy as sensitizers. [J Radiat Res 44:425 (2003)]

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Angiogenesis is required for the growth and progression of malignancies. Recent studies have shown that the p53 gene is one of the factors for determining cellular thermosensitivity. Previously, we have reported that the cellular thermosensitivity of wild-type (wt) p53 cells was higher than that of p53-deficient or mutant (m) p53 cells. We have also found that the thermosensitivity of wtp53 tumors was higher than that of mp53 tumors. These findings suggest that the induction or suppression of tumor environmental factors due to a p53-dependent manner may contribute to the kinetics of tumor regrowth after hyperthermia. However, the correlation of p53 functions and the induction of VEGF by hyperthermia remains unclear. In the present study using human glioblastoma cells, we found that the accumulation of VEGF was induced by hyperthermia at 44 degrees C in the mp53 cells, but not in the wtp53 cells. We will discuss the contribution of p53 gene to anti-tumor effects of hyperthermia. [J Radiat Res 44:426 (2003)]

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A stable membrane-permeable nitroxide, Tempo, exerts an SOD-like antioxidant activity against ROS. Reportedly, Tempo inhibits ROS-induced thymocyte apoptosis, while 10 mM Tempo activates JNK1 to induce apoptosis in breast cancer cells. We have observed that nontoxic 5 mM Tempo enhances suboptimal hyperthermia (44C/10 min)-induced apoptosis in U937 cells. We have been investigating the sensitizing mechanism(s), focusing on activation and targeting of Bax to mitochondria, changes in intracellular and mitochondrial Ca²⁺ concentrations ([Ca²⁺]i, [Ca²⁺]m), and in mitochondrial membrane potential which mediate the mitochondrial permeability transition (MPT), and cytochrome c release from mitochondria to the cytosol that activates the downstream apoptosome in the mitochodnrial death pathway. Our results suggest that the above sensitization involves the two principal mechanisms: (1) the increased permeability of the outer mitochondrial membrane by the direct targeting of activated Bax to mitochondria and (2) the Ca²⁺-mediated MPT, leading to cytochrome c release, mitochondrial dysfunction and ultimately to cell death. [J Radiat Res 44:426 (2003)]

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We studied about radioprotection effect in Lyophyllum decastes sing and Propolis. We used C57Bl and ICR mice in FACS. And we used too ICR mice in antioxidant activity.Increase in the number of leukocytes, the number of lymphocytes, the number of monocytes and the number of granulocytes was seen in the L group and the M group. And, increase in the CD3,CD4 double positive cell was recognized, too. As for the P group, increase in LP activity and increase in the CD3,CD4 double positive cell were recognized. SOD activity related to scavenging of superoxide in the L group and the M group was recognized with the anti oxidization ability. And, the PX GROUP before the irradiation recognized repression of a decrease of the number of lymphocytes right after the irradiation. [J Radiat Res 44:426 (2003)]

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We previously found that drinking beer reduces chromosome aberrations in blood lymphocytes that were collect and irradiated in vitro. In this study, human whole blood was in vitro exposed to 200 kVp X rays or 50 keV/μm carbon ions in the presence or absence of beer, ethanol and β-pseudouridine (one of the beer components). All three agents reduced the chromosome aberrations (dicentric) caused by either X rays or carbon ions of 4 Gy. The maximum protection for X rays by ethanol, beer and β-pseudouridine was 64%, 26% and 34%, respectively, while the maximum protection for carbon-ion by ethanol, beer and β-pseudouridine was 22%, 26% and 32%, respectively. It is concluded that β-pseudouridine, a nucleoside present in tRNA, is a potent protector against damage caused by radiation with direct and indirect actions. [J Radiat Res 44:426 (2003)]

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Edaravone (Radicut) is a brain protecting agent clinically used for acute ischemic stroke with a reaction mechanism of free radical scavenging. Since the initial process of radiation damages is the formation of free radicals, the drug is expected to be effective for the protection of the lethal damage caused by ionizing radiation. In the present study, we examined in vivo radioprotection of edaravone against whole body X-ray irradiation of mice. A solution of edaravone was administered intraperitoneally to mice (C3H, male, 10 weeks old) and the mice were irradiated at the total dose of 8.0 Gy. Edaravone showed significant radioprotection. Edaravone injected at 30 min before the X-ray irradiation showed the strongest radioprotection, whereas the injection earlier or later than at 30 min showed less effect. The injection after the X-ray irradiation showed no effect. Since the radioprotection is observed only when the reagent was administered before irradiation, the primary action of edaravone is quenching of free radicals generated by the irradiation. [J Radiat Res 44:426-427 (2003)]

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HSP90 combines many oncogene products and cell-signaling moleculues, and it plays a key role in the function and stability of these moleculues. We examined the effects of HSP90 inhibitors, geldanamycin (GA) on radiosensitivity and signal transduction pathways in normal and tumor cells derived from mouse and human. GA radiosensitized all tumor cells used in this experiment, but the degree of the radiosensitization were depend on cells. On the other hand, GA hardly sensitized normal cells to radiation. EGFR family that consisted of EGFR and ErbB-2 is client proteins of HSP90. We found that GA reduced EGFR and ErbB-2 levels in DLD-1, T-24, and normal cells, and reduced only ErbB-2 level in HMV-1 cells. GA also reduced the high basal levels of p-Akt in tumor cells, but normal cells have low basal levels of p-Akt. These findings suggest that GA enhances radiosensitivity of tumor cells by inhibiting PI3K/Akt signaling pathway. HSP90 inhibitor such as geldanamycin should be a potent therapeutic agent that can sensitize tumor cells, but not normal cells. [J Radiat Res 44:427 (2003)]

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Selenium compounds are known to have cancer preventive effects. It is reported recently that selenomethionine (SeMet) can protect cells with wild type p53 from UV-induced cell killing by activating the DNA repair mechanism of p53 via redox factor Ref1 by reducing p53 cysteine residue 275 and 277. We examined the effect of SeMet on X-ray sensitivity in several cell lines with different p53 status by clonogenic assay in vitro. Cell lines used were as follows: H1299/neo; human lung cancer cell line of p53 null type, H1299/wp53; wild type p53 transfected counterpart. A172/neo and SAS/neo; human glioblastoma and tongue cancer cell line with wild p53. A172/mp53-248 and SAS/mp53-248; mp53 (248-mutant, ARG to TRP) transfected counterpart. SeMet (20uM, 24 hours) had no cytotoxicity in these cell lines. SeMet (20uM, 24 hours) had no modification effect on radiation cell killing in these cell lines except A172/neo, which was sensitized by SeMet. The effects of p53 on interaction of SeMet and X-ray differ according to cell lines. [J Radiat Res 44:427 (2003)]

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Amrubicin (AMR) is a totally synthetic 9-aminoanthracyclin anticancer drug. The antitumor activity of adriamycin (AMR) was found to be superior to that of ADM in experimental therapeutic models with human tumor xenografts. AMR was converted in vivo to major metabolite, amrubicinol (AMROH), which was markedly more effective cytotoxic agent than the parent compound. We examined chemical modification of radio- and thermo-sensitivity by AMR or AMROH in cultured human lung adenocarcinoma A549 cells. Sublethal damage repair (SLDR) was inhibited by the pretreatment with AMR or AMROH followed by X-irradiation. This finding suggests the possibility of the combined treatment of AMR or AMROH and X-irradiation as clinical cancer therapy strategy, since the doses in the routine clinical cancer therapy is ranged within 2 Gy, so-called "sublethal doses". We also found that SLDR was inhibited by the pretreatment with AMR or AMROH followed by hyperthermia. [J Radiat Res 44:427 (2003)]

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Usually, temperature of over 42.5C were used for clinically in hyperthermic treatment. We observed that temperature below 41C has effects of increase the immunological activity on mild hyperthermia. We used animals were SCC-VII tumor bearing C3H mouse. These mouse were treated with mild hyperthermia as below 41C,30min by water bath. Mild hyperthernia were carried out as continue and several intervals treatment. Anti-tumor effects were observed in the continuous treatment than the intervals treatment group. NK cells activity were increase in the continuous treatment than the interval treatment, and aloso enhance the apoptosis generation. Increased the number of lymphocytes and white blood cells after continuous treatment. These results suggest that mild hyperthermia has effects the patients QOL and control the metastasis for patients after cancer treatment in clinically. [J Radiat Res 44:427-428 (2003)]

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It has been shown that heat treatment has lethal effects on mammalian cells. Generally, cells in S phase are resistant to X-rays, whereas they are the most sensitive to heat shock. We have previously reported that heat shock induces centrosome dysfunction. Because centrosome duplication occurs during S phase, we examined the effect of heat shock on centrosome in normal human diploid (HE49) cells during S phase. HE49 cells were synchronized in G0, then 16hr after release we labeled early S phase cells with BrdU. The frequency of cells with abnormal centrosomes was examined 72hr after heat shock, and 86% of BrdU-positive cells showed the abnormality of the centrosome (multiple, minute and no), whereas those cells were 66% of BrdU-negative cells. Especially, cells with no centrosome were frequently detected in BrdU-positive cell. These results indicate that heat shock causes more detrimental effects on centrosomes in early S phase, the resultant failure in cell division, could result in cell death. [J Radiat Res 44:428 (2003)]

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DNA-PK is considered one of critical enzymes in the repair and/or signal transduction of DNA double-strand breaks. We and others have demonstrated hyperthermic lability of Ku subunits in DNA-PK as a possible mechanism for hyperthermic radiosensitization. We have examined in detail the effects of hyperthermia on DNA-PK in situ, i.e., in various cultured cell lines from mouse, hamster, human and chicken. We found that DNA-PK activity in human cells was more heat resistant than that in rodent cells. In conjunction with this, human cells exhibited smaller hyperthermic radiosensitization than rodent cells. Additionally, the activity could be restored when cells were returned to normal temperature and DNA-PK became less heat-sensitive in thermotolerant cells. The elucidation of the mechanisms protecting and recovering DNA-PK from heat damage may possibly provide a new approach to improve cancer therapy through hyperthermia, either by itself or in combination with radiation. [J Radiat Res 44:428 (2003)]

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To explore the roles of two major pathways of DNA double-strand break repair, i.e., NHEJ and HR, in hyperthermic radiosensitization, we examined chicken B lymphocyte DT40 cells and its derivatives lacking Ku70, DNA-PKcs or Rad54. When these cells were irradiated with X-ray after 20 or 40min-treatment at 46°C, the radiosensitivity was enhanced in any of mutants as well as wild-type cells. Notably, however, in Ku70-/- and DNA-PKcs-/-/-, which are consisted of two subpopulations with greatly different radiosensitivity, the radioresistant fraction, rather than the radiosensitive fraction, was sensitized. It has been considered that the radioresistant fraction of these cell lines might represent cells in late S- and G2-phases, with efficient repair through HR. In conjunction with this, the present observation suggested that hypethermia might have inhibited homologous recombinational repair of DNA double-strand breaks. [J Radiat Res 44:428 (2003)]

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Since the Gulf-Bay war in 1991, usage of depleted uranium was big problem which may cause severe health effects. DU bullets were used in the Iraq War in 2003, however, isotopic evidence has not been reported.In the present work, U-235/U-238 isotopic ratios were measured by gamma spectrometry for the samples collected just after the end of Iraq War. The samples are black powderfrom desgtroyed factory, powder collected by smear method from inner wall of tank and bullets surface.U-238 and U-235 were determined by 63 keV gamma ray from Th-234 and 186 keV one from U-235 by Ge detectors in Ogoya Underground Laboratory. The U-235/U-238 isotopic ratios were measured to be 0.209 ± 0.04% for black powder, 0.186 ± 0.006% for fine powder from inner wall of tank and 0.197 ± 0.011% for bullet surface. These values agree with those measured by Kosovo samples indicating that DU were used in the Iraq War. [J Radiat Res 44:429 (2003)]

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The tritium gas (HT) oxidizing bacteria were isolated from cultivated soils in Ibaraki Prefecture. Among 963 isolates, 92% were actinomycetes, and its one-tenth were actinomycetes with meso-DAP in their cell wall. The isolated strains with meso-DAP were divided into 4 groups according to morphological and chemotaxonomic analyses. 16S rRNA sequence analyses were also conducted for some representative isolated strains. The several strains belonged to the group with gray colony color, smooth-surface spores, long straight spore chains, meso-DAP, galactose and mannose as whole-cell sugars, phospholipid type of II, non-mycolic acids, and menaquinones were classified to the genus Kitasatospora. Their tritium gas oxidizing activities were somewhat higher than those of the other isolates. [J Radiat Res 44:429 (2003)]

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We evaluated separation factors of deuterium and tritium on SPE (Solid Polymer Electrolyte) electrolytic enrichment. Enrichment of 6.3 and 8.4 times was observed for deuterium and tritium, respectively, when 1000 ml water was reduced to 61 ml. The isotopic equilibrium of tritium and hydrogen atom between molecular hydrogen and water vapor determined the separation factor because the obtained separation factor is close to the reported value for the isotopic equilibrium. Chemical composition of rain before and after the electrolytic enrichment showed elevation of H⁺ and Na⁺ and reduction of Mg²⁺ and Ca²⁺ concentrations. F⁻, which was not contained in the sample, was observed after the enrichment with reduction of SO₄^2-, Cl⁻ and NO₃⁻ concentrations. The change of ionic composition is attributed to the material of SPE, which uses F-type cation-exchange membrane. The tritium concentrations in Kumamoto City was mostly less than 1 Bq/L and showed a relationship with pH, probably suggesting a long rage transport from the China continent. [J Radiat Res 44:429 (2003)]

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Squids, a member of marine mollusks, have been used as a "biological monitor" for evaluating the Ag-108m contamination in the marine environment, since the presence of the nuclide in the lever of squids was firstly reported in 1970. We reported that not only squids but also snails(gastropods), another member of mollusks, could be used successfully for the purpose, and showed that Ag-108m was possibly distributed rather uniformly from coast to coast and from surface to bottom in the coastal sea of Japan on the basis of the consistent values of the specific activity of the nuclide in the viscera of the mollusks. The present study reports the results of additional analyses of the Ag-108m specific activity in another species of mollusks including a species of octopus obtained in the fishry ports different from the previous study. The need for a more conprehensive investigation was also stressed in order to prepare information on the backgound level of Ag-108m in the marine environment of concern for the commencement of operation of the spent fuel reprocessing plant in due time. [J Radiat Res 44:429 (2003)]

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¹³⁷Cs, which is of great interest and importance as an indicator of radioactive pollution in marine environments, is one of the long-lived artificial radio-nuclides introduced by the atmospheric deposition of debris from nuclear explosions mainly before 1962. For the estimation of effects of the effluents from nuclear facilities, it is necessary to know the natural variations in the concentration of ¹³⁷Cs and factors affecting variations in marine organisms. We observed positive correlation between growth and ¹³⁷Cs in 4 species among 14 major teleost species from fishing grounds along the coast of Japan. No increase in ¹³⁷Cs concentration with increase of growth was observed in 2 species. In the remaining species no specific correlation is observed. These differences in the patterns were dependent on a change of food habits with growth. As little is known of the ¹³⁷Cs concentration in selachian we have investigated the natural variations of ¹³⁷Cs in stingray. The correlation between growth and the concentration of ¹³⁷Cs in stingray will be discussed. [J Radiat Res 44:430 (2003)]

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Epidemiological studies of radiologists, radiologic technologists, and other medical radiation workers have been conducted in several countries. Since many of the study populations started radiological work before introduction of routine monitoring of occupational exposure, cancer risks have not been well examined in terms of exposure dose. Most of the studies used surrogate variables for exposure doses, e.g., calendar year employed, showing significantly higher cancer risks among those who worked in earlier periods. In Chinese and Japanese studies, occupational doses were estimated for sub-cohorts of the studies, based on information on past work history etc. In the US radiologic technologists study, occupational doses are being estimated using archived dosimetry records together with individual work histories and literature-based annual dose estimates for early periods. Although the reconstructed doses can involve much uncertainty, retrospective dosimetry in epidemiological studies of medical radiation workers is essential for better understanding of risk due to chronic exposure to low to moderate doses of radiation. [J Radiat Res 44:430 (2003)]

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We evaluated the teratogenesis and DNA damage caused by maternal exposures to protein synthesis inhibitor, tritiated water, and gamma-rays in rats. Pregnant Donryu rats were exposed to Fertilysin, tritiated water (HTO) and gamma-rays on days 9-18 of gestation. The animals were sacrificed on day 18 of gestation and examined for lethality and surviving fetuses, and they were microdissected. Teratogenesis occurred in a dose dependent manner in each treated group. Our studies showed that Fertilysin, HTO and gamma-rays exposure induced similar malformations of the craniofacial, cardiovascular, respiratory and skeletal systems in rat fetuses. These included craniofacial anomalies, conotruncal anomalies, aortic arch anomalies, thymic defects, lungs and trachea defects as well as limb and tail malformations in HTO syndrome. These results are similar to those found in human DiGeorge syndrome, which are considered pharyngeal arch syndromes related to a cephalic neurocristopathy. [J Radiat Res 44:430 (2003)]

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At radiation emergency with heavy internal-contamination, prompt estimation of doses at specific organs is sometimes needed for planning clinical treatments. Recently developed biokinetic models of ICRP permit more realistic description of the behaviour of radionuclides in human body. This, however, has made the interpretation of bioassay data extremely difficult. Thus computer programs for implementing these models have become needed, but very few. The present work provides a PC software: MONDAL3 (Monitoring to Dose Calculation Ver.3) that enables users, even if non-specialists, to estimate readily intake of radionuclides and resulting equivalent doses in organs and effective doses at radiation emergency with internal contamination from measurement results of radioactivity in a whole body or in specific organs or in excreta. [J Radiat Res 44:430 (2003)]

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IVR techniques are remarkablly advanced recently. We present 6 cases of radiation ulcer/dermatitis as late effects in the skin due to CAG or PTCA. Case1: 60y.o,woman. She received four times of CAG or PTCA (totally 58.5Gy). Radiation ulcer was detected 4 months after final examination. Case2: 68y.o,woman. She received 5 times of examination(totally 45.5Gy), radiation ulcer was made 22 months after final examination. Case3: 77y.o,man. He received 4 times of CAG or PTCD. Radiation ulcer was found 6 months after final examination. Case 4:61y.o,woman. She received 3 times of CAG or PTCA , fainaly radiation ulcer was detected 15 months after final examination. Case5:66y.o,man. He received 4 times of CAG or PTCA(totally 25.8Gy), it coursed radiation ulcer . Case6 :65y.o,women. 11 times of CAG or PTCD were performed and he is still sufferring from radiation dermatitis. To avoid the radiation ulcer as a late effect of CAG or PTCD, radiologists must educate the doctors of other department and should take care of irradiated dose in each examination. [J Radiat Res 44:430-431 (2003)]

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As a standard biodosimeter, scoring chromosomal aberrations is widely used (cytogenetic biodosimeter). However, when cells are irradiated with large doses (more than 10 Gy), most cells arrest in G2 phase and do not enter mitosis and it is thus difficult or even impossible to obtain chromosomes using conventional colcemid block. Therefore, this problem has limited the use of cytogenetic biodosimeter for estimate the irradiation dose over 10 Gy. Recently, Gotoh and Asakawa first overcame this limitation using their developed drug induced premature chromosome condensation (PCC) method. Based on this report, Kanda et al. then proposed an easy method for biodosimeter by scoring Giemsa stained ring chromosomes using drug induced PCC method. Here we report that the total number of Giemsa stained prematurely condensed chromosomes well correlates to the irradiation dose, and combined with the PCC index, it is possible to estimate the irradiation dose up to 40 Gy with quite ease and quick. Therefore, we propose this simple protocol for a new cytogenetic biodosimeter. [J Radiat Res 44:431 (2003)]

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Some results by geographical correlation studies can raise a social concern even for small radiation risks due to nuclear power plant (NPP) routine operations. Our recent analysis showed no increased risk for solid cancer mortality in areas with a NPP in Japan. Further examinations using Poisson regression were conducted for mortality rates from digestive cancers. Digestive cancer constituted about 65.6% of all solid cancers in 100 selected municipalities. A minimum latency of 5 years was assumed from the commissioning year of a NPP. A small decreased risk of digestive cancer mortality in all periods and 20 municipalities with a NPP was found compared with in the remaining 80 control areas. Similar results were seen for each gender but for ages at death of 50 years old or more, especially for stomach cancer. Variations of apparent excess risk were considered to be due to heterogeneities of factors (the environments, life-styles, and disease misclassification) to determine temporal pattern of digestive cancer mortality at old ages as well as statistical randomness. [J Radiat Res 44:431 (2003)]

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DNA double strand break (DSB) causes many cytotoxic effects such as cellular lethality, somatic mutation, and carcinogenesis. Fidelity of DSB repair is a important factor that determines the quality of genomic stability. It is known that the most of DSBs are properly repaired on the earth, however, little is known whether those are rejoined at the same fidelity even under the space environment. One of the DSB repair pathway, homologous recombination (HR), allows the cells to repair their DSBs with error free. Therefore, the efficiency of HR is a good index to assess the fidelity of DSB repair. In order to clarify the effect of gravity stress on HR pathway, we established a cell line that can detect a site-specific DNA repair via HR. The cells carrying a reporter construct for HR were incubated under hypergravity condition after induction of site specific DSB. Our preliminary results suggest that the gravity stress may affect the HR efficiency. Further analysis is in progress. [J Radiat Res 44:431 (2003)]

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Effects of heavy ion particle radiation on mature rats were examined to know damages in astronauts during and after space radiation exposure. Two hundred female Wistar rats of 12 months old were divided into five groups (n=40), and heavy ion (Carbon) particle radiation induced by HIMAC was irradiated to four groups with doses of 0.5, 0.75, 1.0 and 5.0 Gy. Rats were bred until death after irradiation. Life spans of each radiation groups were significantly shorter than that of control group. In the 0.75 and 1.0Gy groups, the incidence of tumors in ovaries and uterus, kung, liver, and digestive tract were higher, but lower in mammary gland and pituitary, than those of control group. Bone mineral density was decreased in the 5.0 Gy group. The results indicate that heavy ion particle radiation of more than 0.75Gy occurs shortening of life span as well as tumors in various organs even in mature rats of low radiation sensitivity. [J Radiat Res 44:431-432 (2003)]

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