All issues
Volume 44 (2003)
- Issue 4 Pages 311-
- Issue 3 Pages 203-
- Issue 2 Pages 95-
- Issue 1 Pages 1-
Volume 44, Issue 3
Displaying 1-14 of 14 articles from this issue
- |<
- <
- 1
- >
- >|
Minireview
-
MIKINORI KUWABARA, KENJI TAKAHASHI, OSAMU INANAMIArticle type: Minireviews
2003 Volume 44 Issue 3 Pages 203-209
Published: 2003
Released on J-STAGE: November 28, 2003
JOURNAL FREE ACCESSA post-irradiation treatment of the human leukemia cell line MOLT-4 with the anitoxidant Trolox attenuated capase-3 dependent apoptosis. The increase in the p53 expression and SAPK/JNK activation after X irradiation was also inhibited by a Trolox treatment, but the expression of BCL-2 and BAX, which would occur downstream from p53, was not changed. Studies on the effects of the intracellular calcium chelator BAPTA-AM on the induction of apoptosis and the activation of SAPK/JNK and capase-3 proved that the chelation of calcium merely delayed the onset of radiation-induced apoptosis and the activation of SAPK/JNK and caspase-3. When the effects of the protein synthesis inhibitor cycloheximde on the apoptotic signaling pathways, including the activation of caspase family proteins and SAPK/JNK, were investigated, the expression of death receptor Fas through SAPK/JNK activation was found to be required for radiation-induced apoptosis. Finally, the relationship between the amounts of DNA dsb and induction of apoptosis was examined by irradiating BrdU-incorporated cells. An increase in DNA dsb caused by BrdU was found, but the induction of apoptosis was not enhanced. From these data, we could get no positive evidence for DNA as a target of X-rays and p53 as an indispensable factor to induced apoptosis in X-irradiated MOLT-4 cells.
View full abstractDownload PDF (323K)
Regular Papers
-
MEHMET KOC, SEYITHAN TAYSI, MEHMET EMIN BUYUKOKUROGLU, NURI BAKANArticle type: Regular papers
2003 Volume 44 Issue 3 Pages 211-215
Published: 2003
Released on J-STAGE: November 28, 2003
JOURNAL FREE ACCESSThe aim of this study was to investigate the antioxidant roles of different doses of melatonin (5 and 10 mg kg -1 ) against γ-irradiation-caused oxidative damage in liver tissue after total body irradiation (TBI) with a single dose of 6.0 Gy. Fifty adult rats were divided into 5 equal groups, 10 rats each. Groups I and II were injected with 5 and 10 mg kg -1 of melatonin, and group III was injected with an isotonic NaCl solution. Group IV was injected with only 5 mg kg -1 of melatonin. Group V was reserved as a sham control. Following a 30-min-period, 6.0 Gy TBI was given to groups 1, 2 and 3 in a single fraction. The liver malondialdehyde (MDA) levels, super oxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities were measured in all groups. TBI resulted in a significant increase in the liver tissue MDA levels and a decrease of SOD and GSH-Px activities. The results demonstrated that the liver tissue MDA levels in irradiated rats that were pretreated with melatonin (5 or 10 mg kg -1 ) were significantly decreased, while the SOD and GSH-Px activities were significantly increased. Decreasing the MDA levels by melatonin was dose dependent, but the liver tissue SOD and GSH activities were not. The data obtained in this study suggest that melatonin administration prior to irradiation may prevent liver damage by irradiation.
View full abstractDownload PDF (68K) -
RENATA KOZICZAK, MARTA GONCIARZ, ANITA KROKOSZ, ZOFIA SZWEDA-LEWANDOWS ...Article type: Regular papers
2003 Volume 44 Issue 3 Pages 217-222
Published: 2003
Released on J-STAGE: November 28, 2003
JOURNAL FREE ACCESSHuman erythrocyte suspensions in an isotonic Na-phosphate buffer, pH 7.4, of hematocrit of 2% were exposed under air to gamma radiation at a dose rate of 2.2 kGy. Erythrocytes were irradiated with single doses, and identical doses split into two fractions with an interval time of 3.5 h between following exposures. The obtained results indicated that the irradiation of enucleated human erythrocytes with split doses caused a reduction of hemolysis (2.4 times), a decrease in the level of damage to membrane lipids and the contents of MetHb, compared with identical single doses. However, the splitting of radiation doses did not change the level of damage to the membrane proteins, as was estimated with a maleimide spin label. The obtained results suggest that a decrease in the level of damage to lipids was related to a decrease in hemolysis.
View full abstractDownload PDF (493K) -
CHUN-MENG SHI, JI-FU QU, TIAN-MIN CHENGArticle type: Regular papers
2003 Volume 44 Issue 3 Pages 223-228
Published: 2003
Released on J-STAGE: November 28, 2003
JOURNAL FREE ACCESSHigh dose of ionizing radiation could cause bone-marrow aplasia and delay wound healing. Nerve growth factor (NGF) has been demonstrated to play roles in wound healing and to affect the functional activities of mature immune and hematopoietic cells. In this study, we investigated the effects of NGF on survival and wound healing in mice with combined radiation and wound injury. Immunohistochemical analysis indicated that the expression of NGF decreased significantly at postwounding days 3, 5, 7, 10 and 14 in wounded tissues combined with total body irradiation of 5 Gy. NGF significantly increased the survival and migration of skin fibroblasts with the irradiation of 15 Gy in in vitro experiments. Intraperitoneal and topical applications of NGF increased the survival rate, peripheral white blood cells and bone-marrow nucleated cells; they also promoted wound healing and increased the cell number of fibroblasts and blood capillaries in granulation tissues. These results showed evidence that NGF could increase wound healing and promote survival in irradiated animals. This dual effect of NGF may provide a new tool for the treatment of radiation-combined injuries.
View full abstractDownload PDF (486K) -
KARPAGAM PASUPATHY, CHERUPALLY KRISHNAN K. NAIRArticle type: Regular papers
2003 Volume 44 Issue 3 Pages 229-235
Published: 2003
Released on J-STAGE: November 28, 2003
JOURNAL FREE ACCESSThe response of different tumours to radiation varies. This variation has been attributed to, among others, varying DNA repair capabilities The response of three tumour lines, differing in their sensitivities to radiation, namely, murine fibrosarcoma, lymphosarcoma and ascites, was studied by following the activities of enzymes known to be involved in DNA repair. The activities of poly (ADP-ribose) polymerase (PARP), DNA polymerase b and DNA ligase in fibrosarcoma, lymphosarcoma and ascites recorded varying degrees of increase following gamma irradiation (2 Gy). The increase was more pronounced in fibrosarcoma, which recorded a maximum 2 h after irradiation for b polymerase, and at 4 h for ligase and PARP, thereafter declining to near normal levels after 24 h. In contrast, the activity of DNA Topoisomerase I declined, corresponding to an increase in the PARP activity. The maximum increase in the activity of β polymerase, ligase and PARP from lymphosarcoma and ascites was observed 2 h after irradiation with a corresponding decrease in Topoisomerase I activity. Search for the target enzymes and proteins for modification by PARP in gamma -irradiated fibrosarcoma tumour cells revealed that nuclei, and not chromatin, were preferentially modified by PARP. Among the nuclear proteins, histones were found to be ribosylated. The enzyme topoisomerase was ribosylated by PARP in vitro, and this modification was found to inhibit topoisomerase activity. We speculate that a possible role of PARP is to coordinate the activities of other enzymes in DNA repair by selectively inhibiting certain enzymes by the ribosylation process.
View full abstractDownload PDF (352K) -
SEYED JALAL HOSSEINIMEHR, HASSAN TAVAKOLI, GHOLAMREZA POURHEIDARI, ALI ...Article type: Regular papers
2003 Volume 44 Issue 3 Pages 237-241
Published: 2003
Released on J-STAGE: November 28, 2003
JOURNAL FREE ACCESSThe radioprotective effects of citrus extract were investigated by using the micronucleus test for anticlastogenic and cell proliferation activity. A single intraperitoneal (i.p.) injection of citrus extract (Citrus aurantium var. amara) at 250, 500, 1,000 mg/kg body weight 1 h prior to γ-ray irradiation (1.5 Gy) reduced the frequencies of micronucleated polychromatic erythrocytes (MnPCES) and normochromatic erythrocytes (MnNCE S). All three doses of citrus extract significantly reduced the frequencies of MnPCEs and MnNCEs in mice bone marrow compared to non-drug-treated irradiated control (p < 0.005-0.05). The optimum dose for protection in mouse was 250 mg/kg to protect mice bone marrow 2.2-fold against the side effects of γ-irradiation with respect to the non-drug-treated irradiated control. The flavonoids were contained in citrus extract, probably to show protective activity, and reduced the clastogenic effect of radiation on mice bone marrow. Therefore fruits and vegetables contain flavonoids to be useful as protective effects under such stress conditions as irradiation.
View full abstractDownload PDF (61K) -
AKIRA OOTSUYAMA, RYUJI OKAZAKI, TOSHIYUKI NORIMURAArticle type: Regular papers
2003 Volume 44 Issue 3 Pages 243-247
Published: 2003
Released on J-STAGE: November 28, 2003
JOURNAL FREE ACCESSThe purpose of this paper is to analyze the relationship between alterations of splenic T-cell subpopulations and the amelioration of autoimmune diseases of MRL/MpTn-gld/gld mice (MRL/gld mice) after extended exposure to low-dose radiation. After the onset of disease, 4-month-old MRL/gld mice were exposed to doses of 0.05, 0.2, and 0.5 Gy/day for 4 weeks (5 days/week), for total doses of 1, 4, and 10 Gy, respectively. The MRL/gld mice that were irradiated with 0.2 and 0.5 Gy/day showed an obvious decrease in the proportion of splenic CD4-CD8- T cells and remission of their autoimmune diseases. After the last irradiation, apoptotic cells were found in the white pulp of the spleen of the MRL/gld mice irradiated with 0.2 Gy/day, but not in the MRL/MpJ-+/+ mice (MRL/wild mice), which experienced a similar treatment. Before the onset of disease, 3-month-old MRL/gld mice subjected to 0.2 Gy/day showed a decrease in the proportion of splenic CD4-CD8- T cells and less remission of their autoimmune diseases than the 4-month-old mice. These results suggest that the accumulated CD4-CD8- T cells are more sensitive to radiation than other T-cell subpopulations, and that decreasing CD4-CD8- T cells with extended exposure to low-dose radiation leads to the amelioration of autoimmune disease.
View full abstractDownload PDF (1300K) -
NOBUKO MORI, JYOJI YAMATE, SEI-ICHI UMESAKO, DOO-PYO HONG, MASAAKI OKU ...Article type: Regular papers
2003 Volume 44 Issue 3 Pages 249-254
Published: 2003
Released on J-STAGE: November 28, 2003
JOURNAL FREE ACCESSBALB/c mice are susceptible to radiation-induced mammary tumors as well as lymphomas. We investigated the effects of the p53 deficient allele and of X-irradiation on the tumor spectrum in the BALB/c background. Substantially all p53 -/-animals died of thymic lymphomas before 36 weeks of age, while none of the p53 +/+ animals died during that period. At this age, mortalities of p53 +/- females and males were 5% (1/22) and 11% (1/9), respectively, due to non-thymic lymphoma and sarcoma. When exposed to 4 Gy of X-irradiation, 100% (44/44) and 95% (18/19) of p53 +/- mice died with tumors within 36 weeks. Among these, the predominant cause of death was lymphoma in either sex [26/44 (59%) in females; 13/19 (68%) in males]; mammary adenocarcinoma (15/44, 34%) and sarcoma (3/19, 16%) were semi-dominant in females and males, respectively. The mortalities of similarly treated p53 +/+ mice were 16% (5/31) in females and 17% (3/18) in males: virtually all deaths were due to thymic lymphomas in either sex. When exposed to 4 ¤ 0.7 Gy of X-irradiation at weekly intervals, 23/23 (100%) of the p53 +/-females died of tumors within 36 weeks. In these animals, mammary adenocarcinoma (15/23, 65%), instead of lymphoma (7/23, 30%), was dominant. None of the similarly treated p53 +/+ females developed malignant tumors during the period. Mammary adenocarcinomas generated in p53 +/- females exposed or non-exposed to radiation showed a frequent loss of the p53 wild-type allele. Hence, we provided a useful experimental system to study radiation-induced mammary tumors in mice.
View full abstractDownload PDF (110K) -
NITIN MOTILAL GANDHI, USULUMARTY VENU GOPALASWAMY, CHERUPALLY KRISHNAN ...Article type: Regular papers
2003 Volume 44 Issue 3 Pages 255-259
Published: 2003
Released on J-STAGE: November 28, 2003
JOURNAL FREE ACCESSDisufiram (a drug used for the treatment of alcoholism) protected microsomal membranes and plasmid DNA against damages induced by gamma-radiation. The peroxidation of membrane lipids increased linearly with the radiation dose up to 600 Gy, and the presence of disulfiram inhibited membrane lipid peroxidation as assayed by the presence of thiobarbituric acid reacting substances. The reduction of the quantity of the supercoiled (ccc) form of plasmid pBR322 DNA is directly related to the radiation-induced damage, particularly to DNA strand breaks. There was a complete protection of plasmid DNA when exposed to gamma-radiation in the presence of disufiram (0.1 mM) at 300 Gy. This drug also protected deoxyribose against damages caused by hydroxyl radicals produced by the Fenton reaction. The administration of DSF to mice prior to whole-body radiation exposure (4 Gy) resulted in a reduction of peroxidation of membrane lipids in mice liver as well as a decrease in radiation-induced damage to cellular DNA, as assayed by single-cell gel electrophoresis (comet assay). The results thus suggest the possible use of DSF as a radioprotector.
View full abstractDownload PDF (449K) -
YOICHI OGHISO, YUTAKA YAMADAArticle type: Regular papers
2003 Volume 44 Issue 3 Pages 261-270
Published: 2003
Released on J-STAGE: November 28, 2003
JOURNAL FREE ACCESSRadiation-induced pulmonary carcinogenesis was compared in female Wistar rats following either inhalation exposure to alpha-emitting 239PuO2 aerosols, whole-body or thoracic X-ray irradiation. Dose-dependent survival reduction was correlated with increased malignant lung tumors at doses over 0.45 Gy, reaching the maximum incidence of 90% at 6.6-8.5 Gy in 239Pu-exposed rats. While the differential dose responses for each histopathological type of tumors were noted, almost 70-80% were carcinomas among all of the primary tumors from 239Pu-exposed rats. As the dose response curves for lung carcinomas were compared, the slope of the fit linear equation and the calculated relative effectiveness for 50% incidence of lung carcinomas were approximately 11-times as high in 239Pu-exposure as those of thoracic X-irradiation. The numbers of tumor lesions distributed in the lung per tumor-bearing animal were about 2-fold more in 239Pu-exposed rats, while the proportions of their histopathological types were similar between 239Pu-exposure and X-irradiation. These results indicate that the magnitudes of the relative effectiveness or risk for pulmonary carcinogenesis are greater in 239Pu-exposure than X-irradiation, and that radiation-induced lung tumors appear to originate mostly from the same target epithelial cells.
View full abstractDownload PDF (274K) -
TAKAKO TAKANAMI, YONGZHAO ZHANG, HIDETOSHI AOKI, TOMOKO ABE, SHIGEO YO ...Article type: Regular papers
2003 Volume 44 Issue 3 Pages 271-276
Published: 2003
Released on J-STAGE: November 28, 2003
JOURNAL FREE ACCESSThe effects of heavy ion particle irradiation on meiosis and reproductive development in the nematode Caenorhabditis elegans were studied. Meiotic pachytene nuclei are significantly resistant to particle irradiation by the heavy ions carbon and argon, as well as to X-rays, but not UV, whereas diplotene to diakinesis stage oocytes and early embryonic cells are not. Chromosomal abnormalities appear in mitotic cells and in maturing oocytes irradiated with heavy ion particles during the diplotene to the early diakinesis stages, but not in oocytes irradiated during the pachytene stage. The pachytene nuclei of ced-3 mutants, which are defective in apoptosis, are similarly resistant to ionizing radiation, but pachytene nuclei depleted for Ce-atl-1 (ataxia-telangiectasia like 1) or Ce-rdh-1/rad-51 are more sensitive. Pachytene nuclei thus appear to effectively repair heavy ion-induced DNA damage by the meiotic homologous recombination system.
View full abstractDownload PDF (1425K) -
LILIANA CIUFFO, HUGO VELASCO, MAR BELLI, UMBERTO SANSONEArticle type: Regular papers
2003 Volume 44 Issue 3 Pages 277-283
Published: 2003
Released on J-STAGE: November 28, 2003
JOURNAL FREE ACCESSIn the present study we assessed the radiocaesium uptake by plants in order to piece together information on factors affecting the uptake processes, particularly K supply and plant species differences. Vegetation uptake from soil contaminated by the Chernobyl accident was compared at two semi-natural grasslands. The Cs/K discrimination factor (DF), which is often used to evaluate a plant's efficiency in absorbing nutrients from soil, was estimated. The obtained DF values (0.01 to 0.8) vary with K soil concentrations and plant species, indicating that the 40K is more efficiently absorbed than 137Cs. The soil-to-plant relationship was evaluated by means of the transfer factor (TF). The 137Cs TFsp values obtained from separated plant species varied within the range of 0.016 to 0.400 (site 1) and 0.017 to 0.171 (site 2). When mixed grass samples were considered a large variation was observed, mainly for site 1. The 137Cs TFmix ranges were: 0.018 to 0.250 for site 1 and 0.017 to 0.167 for site 2. These values fall within the range of TFs commonly reported (0.0001-1). Our present data suggest that these pastures are apt for forage use. Different plant species presented different individual behavior regarding their 137Cs TFsp when the 40K soil activity concentration was taken in account. For most of the species analyzed, we observed a gradual decrease in the individual 137Cs TFsp when the 40K soil activity concentration was increased, with the exception of Taraxacum officinale at one of the sampling sites.
View full abstractDownload PDF (206K) -
DARYOUSH SHAHBAZI-GAHROUEIArticle type: Regular papers
2003 Volume 44 Issue 3 Pages 285-287
Published: 2003
Released on J-STAGE: November 28, 2003
JOURNAL FREE ACCESSThe natural background radiation has been measured in one of the highest altitude regions (Zagros Mountains), Chaharmahal and Bakhtiari province, in the south west of Iran. The outdoors-environmental monitoring exposure rate of radiation was measured in 200 randomly chosen regions using portable Geiger-Muller and scintillation detectors. Eight measurements were made in each region and an average value was used to calculate the exposure rate from natural background radiation. The average exposure rate was found to be 0.246 μGy/h and the annual average effective dose equivalent was found to be 0.49 mSv. An overall population-weighted mean outdoor dose rate was calculated to be 49 nGy/h, which is higher than the world-wide mean value of 44 nGy/h, as reported by UNSCEAR in 1998, and is comparable to the annual effective dose equivalent of 0.38 mSv. A good correlation between the altitude and the exposure rate was observed, as the higher altitude regions have higher natural background radiation levels.
View full abstractDownload PDF (483K)
Short Communication
-
PERVEEN AKHTER, MUHAMMAD KHALEEQ-UR-RAHMAN, KUNIO SHIRAISHI, HISAO KAW ...Article type: Short communications
2003 Volume 44 Issue 3 Pages 289-293
Published: 2003
Released on J-STAGE: November 28, 2003
JOURNAL FREE ACCESSTo strengthen the radiation protection infrastructure in Pakistan, the uranium concentration in daily diet was measured and its associated radiation risks were estimated for the adult population. Food samples were collected from major cities and districts of the country by the market basket method, from which daily diets were prepared. These diet samples were analyzed using inductively coupled plasma mass spectrometry (ICP-MS) at the National Institute of Radiological Sciences, Japan, the regional Central Reference Laboratory of the Reference Asian Man Project. The measured values of the uranium content were found to vary from 2.3 ng (g dry)-1 to 11 ng (g dry)-1. The geometric mean concentration and geometric standard deviation were 4.5 ×/÷1.7 ng (g dry)-1. This leads to a daily dietary intake of 2.6 ×/÷ 1.7 μg d-1 or 33 ×/÷ 1.7 mBq d-1, which is approximately 40% higher than the ICRP value. The measured value, i.e. 33 mBq d-1, contributes 12 Bq y-1 to annual intake of 238U activity and 0.54 μSv to the committed effective dose to the adult population. This is a very small fraction of the ICRP annual effective dose limit of 1 mSv for the general public. Therefore, it would pose no significant health hazard.
View full abstractDownload PDF (90K)
- |<
- <
- 1
- >
- >|