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Volume 42 (2001)
- Issue 4 Pages 347-
- Issue 3 Pages 247-
- Issue 2 Pages 117-
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Volume 42, Issue 2
Displaying 1-9 of 9 articles from this issue
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Regular Papers
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TOSHIYUKI FUKUHARA, GERALD B. SHARP, TERUMI MIZUNO, HIDEYO ITAKURA, MA ...Article type: Regular papers
2001 Volume 42 Issue 2 Pages 117-130
Published: 2001
Released on J-STAGE: October 27, 2001
JOURNAL FREE ACCESSHistological features of primary liver cancer among atomic-bomb survivors and their relationship to hepatitis B (HBV) and C viral (HCV) infections are of special interest because of the increased risk of liver cancer in persons exposed to ionizing radiation and the high and increasing liver cancer rates in Japan and elsewhere. We conducted a pathology review of liver cancers occurring from 1958 to 1987 among subjects in the 120,321 member cohort of 1945 Hiroshima and Nagasaki residents. A panel of pathologists classified tumor histological types and defined accompanying cirrhotic changes of the liver. Archival tissue samples were assessed for HBV using pathology stains and PCR. Reverse transcriptase (RT) PCR was used to determine HCV status. We used unconditional logistic regression to compare 302 hepatocellular carcinoma (HCC) cases to 53 cholangiocarcinoma (CC) cases, adjusting for age, year of diagnosis, sex and viral status.View full abstractDownload PDF (58K) -
NATSUO OYA, KEISUKE SASAI, TORU SHIBATA, TAKEHISA TAKAGI, KEIKO SHIBUY ...Article type: Regular papers
2001 Volume 42 Issue 2 Pages 131-141
Published: 2001
Released on J-STAGE: October 27, 2001
JOURNAL FREE ACCESSWe compared the tumor reoxygenation patterns in three different murine tumor cell lines after X-irradiation with those after carbon-beam irradiation using a heavy-ion medical accelerator (HIMAC) system. The tumors of the cell lines SCCVII, SCCVII-variant-1 and EMT6 on the hind legs of mice received local priming irradiation with a carbon-beam (8 Gy, 73 keV/μm in LET, 290 MeV/u, 6 cm SOBP) or X-rays (13 Gy, 250 kVp). After various intervals, the mice were given whole-body test irradiation (16 Gy, 250 kVp X-ray) either in air or after they were killed. The hypoxic fractions were estimated as the proportions of the surviving fractions of the tumors in <killed mice to those in air-breathing mice. In the SCCVII tumors, the hypoxic fractions at 0.5 h were 50% and 21% (p<0.05) after the priming X-irradiation and carbon-beam irradiation, respectively. In the SCCVII-variant-1 tumors, the hypoxic fractions were 85% and 82% at 0.5 h, 84% and 20% at 12 h (p<0.01), and 21% and 31% at 24 h after X-ray and after carbon-beam irradiation, respectively. In the EMT6 tumors, the reoxygenation patterns after X-irradiation and carbon-beam irradiation were quite similar. We concluded that the reoxygenation pattern differed among the three tumor cell lines, and that reoxygenation tended to occur more rapidly after carbon-beam irradiation than after X-irradiation for SCCVII and SCCVII-variant-1 tumors.View full abstractDownload PDF (80K) -
YUMIKO NITTA, SATORU ENDO, NARIAKI FUJIMOTO, KENJI KAMIYA, MASAHARU HO ...Article type: Regular papers
2001 Volume 42 Issue 2 Pages 143-155
Published: 2001
Released on J-STAGE: October 27, 2001
JOURNAL FREE ACCESSFemale rats of the Fischer 344 strain at ages of 1, 4 and 9 weeks were exposed to 131I intraperitoneally with activities of 0.38, 1.03 and 3.42 kBq per gram of body weight under the condition of iodine deficiency. The absorbed doses in the thyroid increased linearly depending on the injected activities. Irradiation at 1 week old caused heavier exposure than those at 4 and 9 weeks old by 7.5 and 7.7 times, respectively; however, damage of the thyroid tissue was more obvious in the 4-week-old groups than in the 1-week-old groups. The absorbed doses in the total body were proportional to the square root of the injected activities. The one-week-old groups were exposed more heavily than the 4- and 9-week-old groups by 3.6 and 4.7 times, respectively, shown by the slow excretion of 131I with the values of effective half-life of 131I activity (Teff). An IDD-treatment was not so effective to enhance the 131I absorption in the total body, as in the thyroid. No matter how the iodine concentration in the blood changed, the 1-week-old groups could not react to normalize the level. We drew standard curves, which enabled us to estimate the absorbed doses in the thyroid and the total body in the case of the injected activities of 131I for the newborn, pubertal and adult rats.View full abstractDownload PDF (1033K) -
NATARAJAN GAJENDIRAN, KIMIO TANAKA, NANAO KAMADAArticle type: Regular papers
2001 Volume 42 Issue 2 Pages 157-163
Published: 2001
Released on J-STAGE: October 27, 2001
JOURNAL FREE ACCESSThe non-target effect of neutron-irradiation was assessed in unirradiated human peripheral blood lymphocytes using an alkaline comet assay. The isolated cells were incubated with an autologous plasma for 1 h at 37°C before performing the assay. The cells exhibited a significant increase in the tailmoment when the irradiated blood (2 Gy, 570 keV neutron) was the source of plasma. The genotoxic effect lasted for 96 h when stored at -20°C. It is believed to be mediated by the release of cytokines or other factors released by the irradiated cells. Plasma obtained from unirradiated blood or further irradiation of plasma did not enhance the tailmoment significantly. Thus, the adverse effect of neutron-exposure can be passed on to unirradiated neighbourhood through irradiated blood tissue without involving cell-cell contact. The non-targeted radiation effect assumes greater consequences in radiotherapy and biodosimetry.View full abstractDownload PDF (109K) -
LAURENCE ROY, VALERIE DURAND, MARTINE DELBOS, IRENE SOROKINE-DURM, FRA ...Article type: Regular papers
2001 Volume 42 Issue 2 Pages 165-177
Published: 2001
Released on J-STAGE: October 27, 2001
JOURNAL FREE ACCESSBecause of the large number of cells to be analyzed in cases of overexposure to ionizing radiation, an automated imaging system is desirable for scoring both translocations and dicentrics. This system should include three essential steps: automatic metaphase finding, automatic image capture at high magnification, and, finally, optimized data analysis for aberration interpretation. We evaluated a new image analysis system (CYTOGEN, IMSTAR, France) and found that its metaphase finder saved time, as much as quadrupling the speed of scoring chromosomal aberrations. Automatic metaphase selection did not appear to induce bias. We confirmed the equivalence of observing aberrations on a screen after automatic image capture and direct observation under a microscope. This work validated all of the steps necessary for obtaining images for automatic chromosomal aberration detection. The protocols for the detection of translocations may now be applied for biological dosimetry. This step will be validated in a future study.View full abstractDownload PDF (284K) -
NICOLAAS A. P. FRANKEN, CHRIS VAN BREE, MARTIJN A. T. VELTMAAT, HANS M ...Article type: Regular papers
2001 Volume 42 Issue 2 Pages 179-190
Published: 2001
Released on J-STAGE: October 27, 2001
JOURNAL FREE ACCESSSensitization by bromodeoxyuridine (BrdUrd) and hyperthermia (HT) on cell reproductive death induced by ionizing radiation was analyzed using the linear-quadratic [S(D)/S(0)=exp{-( αD+βD2 )}] model. Plateau-phase human lung tumor cells (SW-1573) and human colorectal carcinonoma cells (RKO) were treated with BrdUrd, radiation and HT. LQ-analysis was performed at iso-incubation dose and at iso-incorporation level of BrdUrd, and at iso-HT doses and iso-survival levels after HT. Clonogenic assays were performed 24 h after treatment to allow repair of potentially lethal damage (PLD). In SW cells BrdUrd, HT or the combination significantly increased the α-parameter (factor 2.0-5.7), without altering the β-parameter. In RKO cells sensitization with BrdUrd increased both α (factor 1.4) and β (factor 1.3) while HT only influenced β (factor 2.1-4.0). The combination did not further increase the α and β. The results indicate that BrdUrd has its main effect on the parameter α, dominant at clinically relevant radiation doses but that HT can affect both α and β. The addition of BrdUrd and HT provides a method to enhance the efficacy of radiotherapy.View full abstractDownload PDF (82K) -
MASAKO NOSE, AKIKO UZAWA, TOSHIAKI OGYU, GEN SUZUKIArticle type: Regular papers
2001 Volume 42 Issue 2 Pages 191-200
Published: 2001
Released on J-STAGE: October 27, 2001
JOURNAL FREE ACCESSAcute radiation induces bacterial translocation from the gut, followed by systemic infection and sepsis. In order to reduce the mortality after acute whole body irradiation, it is essential to control bacterial translocation. In this study, we established a bacterial translocation assay as a sensitive method to detect minor mucosal injury by radiation. By utilizing this assay, we evaluated the adverse effects, if any, of hematopoietic reagents on the mucosal integrity in the respiratory and gastro-intestinal tracts. Bacterial translocation to the liver and spleen occurred after whole-body irradiation if the dose exceeded 6 Gy. The administration of G-CSF unexpectedly increased the bacterial translocation in 8 Gy-irradiated mice. The pharmaceutical preparation of low-virulent Streptococcus pyogenes, OK-432, significantly reduced the endotoxin levels in peripheral blood without any reduction of bacterial translocation. A combined treatment with G-CSF and OK-432 decreased bacterial translocation and prevented death. This result indicates that the early administration of G-CSF has an adverse effect on bacterial translocation, and that a combined treatment of G-CSF and OK-432 attenuates the adverse effect of G-CSF and improves the survival rate after acute irradiation.View full abstractDownload PDF (106K) -
HIROKO HAMA-INABA, KEUN HEE CHOI, BING WANG, KEIKO HAGINOYA, TAKESHI Y ...Article type: Regular papers
2001 Volume 42 Issue 2 Pages 201-215
Published: 2001
Released on J-STAGE: October 27, 2001
JOURNAL FREE ACCESSWe previously observed that p53-mutated human epithelial tumor A431 cells underwent apoptosis after ultraviolet C (UVC) irradiation through the caspases-8 and -3 pathway. Fas/FasL is known to initiate apoptosis in several cell lines via caspase-8 activation. Then, to determine if Fas/FasL mediates apoptosis in A431, we investigated Fas expression and modulation in UVC-irradiated A431 cells. A431 constitutively expressed Fas, which gradually decreased after UVC-irradiation. Pretreatment with a neutralizing anti-Fas antibody, ZB4, did not abrogate the UVC-induced apoptosis. An agonistic anti-Fas antibody, CH11, very slowly induced apoptosis in A431, suggesting that the constitutively expressed Fas had a low functional potential. Hence, UVC-induced apoptosis in A431 seems to occur independent of the Fas signal. Interestingly, however, a pretreatment with CH11 remarkably potentiated UVC-induced apoptosis. An inhibitor of caspase-8, Ac-IETD-CHO, partially inhibited UVC-induced apoptosis. JNK was phosphorylated immediately after exposure to UVC, prior to apoptotic chromatin condensation. Our data suggest that the activation of caspase-8 occurs independent of Fas upregulation, and that JNK/SAPK contributes to UVC-induced apoptosis in human epithelial A431 cells.View full abstractDownload PDF (248K) -
KARPAGAM PASUPATHY, CHERUPALLY K. K. NAIR, TSUTOMU V. KAGIYAArticle type: Regular papers
2001 Volume 42 Issue 2 Pages 217-227
Published: 2001
Released on J-STAGE: October 27, 2001
JOURNAL FREE ACCESSYeast Saccharomyces cerevisiae can exist in two physiological states, namely anaerobic and aerobic. They differ in their response to gamma- radiation and radiomodification. We report hereon our results concerning radiosensitization by Sanazole (AK-2123), a well-known hypoxic radio sensitizer, whose mechanism of action has been studied extensively. The results have revealed that Sanazole (1mM) when present during irradiation could specifically sensitize wild-type anaerobic yeast cells with a DMF of 2.4. In a radiation-sensitive mutant which lacks a DNA repair pathway specific for the recovery from gamma-radiation induced DNA damage, the extent of sensitization was considerably lower and the DMF was only 1.3. Studies on the liquid holding recovery of cells of both wild- type and rad52 yeast cells exposed to radiation in presence of Sanazole revealed that sensitization by Sanazole is due to a preferential increase in the DNA damage, and not by impairing DNA repair. This system thus holds promise for screening potential hypoxic chemical radiosensitizers.View full abstractDownload PDF (77K)
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