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| 1.
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Kakimoto, Hitoshi ; Oka, Hideo ; Harada, Yumiko ; Ushijima, Shigeru ; Toriba, Akira ; Kizu, Ryoichi ; Hayakawa, Kazuichi
概要:
Dioxins are present as impurities in agrochemicals applied to the soil. To examine the possibility that dioxins end up in the atmosphere, we compare the homologue composition and some characteristic isomer distributions of
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polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) in air and soil samples collected at sites in Ishikawa Prefecture, Japan. Tetrachloro dibenzo-p-dioxin (TeCDD) was the most abundant PCDD homologue in the air samples, while octachloro dibenzo-p-dioxin (OCDD) was the most abundant PCDD homologue in the soil samples. However, at several site, the most predominant homologue in the soil sample was not OCDD but TeCDD. The mean ratio of TeCDDs to PCDDs in the air samples was significantly smaller in winter than in other seasons, but no such seasonal variation was observed in the distribution of PCDF homologues. The abundance of PCDF homologues was inversely related to the number of chlorine substitutions in the air samples. The contribution of each toxic isomer (2,3,7,8-chlorine-substituted) to the total toxicity equivalency quantity (TEQ) in the air samples tended to be intermediate between their contributions to the TEQs in the soil and cinder samples. This result suggested that the air samples were influenced by both soil/dust suspension and combustion. In order to clarify the contributions of agrochemicals to dioxins in the air, we focused on the ratios of several characteristic isomers that are indicators of agrochemicals (chloronitrophen: CNP and pentachlorophenol: PCP) to their homologues. Significant decreases in the ratios of the isomers to their homologues in the air samples were observed only in winter, probably as a result of suppression of dust suspension by the snow cover. Therefore, the contribution of combustion to the dioxin concentration in the air was thought to be relatively large in winter.
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| 2.
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Tozuka, Yoshiko ; Watanabe, Nobue ; Osawa, Masanobu ; Toriba, Akira ; Kizu, Ryoichi ; Hayakawa, Kazuichi
概要:
Polycyclic aromatic hydrocarbons (PAHs) were analyzed in maternal blood and fetuses from Fischer 344 rats exposed to diesel exhaust (DE) during pregnancy, and in breast milk from rats exposed to DE during pregnancy and lactation using
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high performance liquid chromatography with fluorescence detection. Concentrations of phenanthrene (Phe), anthracene (Ant) and benz[a]anthracene (BaA) were significantly higher in maternal blood of the DE group than those of the control group. Concentration of Phe in fetuses of the DE group was significantly higher than those of the control group. Concentrations of fluorene, Ant, fluoranthene (Flu), pyrene (Pyr), BaA and chrysene (Chr) tended to be higher in fetuses of the DE group. The levels of Ant, Flu, Pyr and Chr in breast milk from the DE group were significantly higher than those of the control group. These results indicate that PAHs taken into mother rat by the inhalation of DE are transferred into fetuses via placenta and into breast milk. This is the first report to clarify the transportation of inhaled PAHs into fetuses and breast milk from mother rats.
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| 3.
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Kizu, Ryoichi ; Otsuki, Naoki ; Kishida, Yoshiko ; Toriba, Akira ; Mizokami, Atsushi ; Burnstein, Kerry L. ; Klinge, Carolyn M. ; Hayakawa, Kazuichi
概要:
We developed a new mammalian cell-based luciferase reporter gene assay for androgenic and antiandrogenic activities of c
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hemicals and environmental samples. Environmental samples usually have a complex matrix that may contain the constituents acting as androgen receptor (AR) agonists, AR antagonists or aryl hydrocarbon receptor (AhR) agonists. AhR agonists are known to elicit the antiandrogenic effect through cross-talk between AR and AhR signal transduction pathways. In this study, PC3/AR human prostate carcinoma cells were transiently transfected with a prostate-specific antigen (PSA) promoter-driven luciferase expression plasmid. The cells were treated with a test compound or an environmental sample for 24 h at 37°C and then measured for luciferase activity. The luciferase activity was induced by dihydrotestosterone (DHT) in a concentration-dependent manner in a concentration range from 10 fM to I nM. R1881, a synthetic androgen receptor agonist, induced luciferase activity and its inductive effects was additive to that of DHT. The luciferase activity was not induced by cortisol, a glucocorticoid, progesterone, a progestin, and 17β-estradiol, an estrogen in a concentration range of up to 1 μM. DHT-induced luciferase activity was reduced by bicalutamide and cyproterone acetate, AR antagonists, and also by benzo[a]pyrene, an aryl hydrocarbon receptor agonist, through AhR-mediated pathways. All of these findings indicate that the present assay system correctly responds to AR agonists, AR antagonists and AhR agonist and, therefore, it is a powerful tool for the sensitive and selective screening of chemicals and environmental samples for their androgenic and antiandrogenic activities. We developed the first assay system, in which the expression of luciferase was driven by the promoter of a prostate-specific antigen gene, a typical human androgen-regulated gene.
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| 4.
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Tang, Ning ; Taga, Rina ; Hattori, Tetsuyuki ; Tamura, Kenji ; Toriba, Akira ; Kizu, Ryoichi ; Hayakawa, Kazuichi
概要:
A method using high-performance liquid chromatography with chemiluminescence detection was developed for analyzing mutagenic nitrobenzanthrone (NBA) isomers in airborne particulates. The method was a modification of our previously
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described method for analyzing nitropolycyclic aromatic hydrocarbons (NPAHs). The pretreatment and reducing conditions for 1-, 2-, 3- and 10-NBAs were the same as those for NPAHs. In order to separate these NBA isomers, we used a polymeric-type ODS column (Cosmosil 5C-18MS); a mixture of 40% acetonitrile and 60% 10 mM imidazole-HClO4 buffer was employed as the mobile phase at a flow rate of 1 mL/min. The isomers of 1-, 2-, 3- and 10-NBA were determined in chemiluminescence with linear calibration graphs from 0.1 to 4 pmol, from 200 to 4000 pmol, from 1 to 50 pmol and from 10 to 400 pmol, respectively. The detection limits (S/N = 3) of 1-, 2-, 3- and 10-NBA isomers were 0.02 pmol, 35 pmol, 0.3 pmol and 3 pmol, respectively. The method was used to analyze airborne particulates at a heavy traffic site in Kanazawa. 2- and 3-NBAs were detected in the extracts of the particulates, while 1-NBA and 10-NBA were not detected. The atmospheric concentrations of 2- and 3-NBAs were 1.83 pmol/m3 and 24.7 fmol/m3, respectively.
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| 5.
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Kizu, Ryoichi ; Hayakawa, Kazuichi
概要:
金沢大学大学院自然科学研究科<br />Proceeding : International Symposium of Kanazawa University 21st-Century COE Program Vol.2(2004),Sch
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edule: February 29(SUN)-March 3(WED), Venue: 29 FEB, Ishikawa Life-Long Learning Center(Former Prefectural Government Building) / 1-3 MAR Kanazawa Art Hall, Organized by: Kanazawa University 21st-Century COE Program / Ishikawa International Cooperation Research Centre / United Nations University-Institute of Advanced Studies, Supported by: Ishikawa Prefectural Government / City of Kanazawa, Eds : Hayakawa, Kazuichi / Kizu, Ryoichi / Kamata, Naoki
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| 6.
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論文
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Chetiyanukornkul, Thaneeya ; Toriba, Akira ; Kizu, Ryoichi ; Hayakawa, Kazuichi
概要:
金沢大学大学院自然科学研究科<br />Proceeding : International Symposium of Kanazawa University 21st-Century COE Program Vol.2(2004),Sch
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edule: February 29(SUN)-March 3(WED), Venue: 29 FEB, Ishikawa Life-Long Learning Center(Former Prefectural Government Building) / 1-3 MAR Kanazawa Art Hall, Organized by: Kanazawa University 21st-Century COE Program / Ishikawa International Cooperation Research Centre / United Nations University-Institute of Advanced Studies, Supported by: Ishikawa Prefectural Government / City of Kanazawa, Eds : Hayakawa, Kazuichi / Kizu, Ryoichi / Kamata, Naoki
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| 7.
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Tamura, Kenji ; Shima, Masayuki ; Tang, Ning ; Hayakawa, Kazuichi ; Sun, Guifan
概要:
国立環境研究所<br />千葉大学<br />金沢大学大学院自然科学研究科<br />China Medical University<br />Proceeding : International Symposium of Kanazaw
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a University 21st-Century COE Program Vol.2(2004),Schedule: February 29(SUN)-March 3(WED), Venue: 29 FEB, Ishikawa Life-Long Learning Center(Former Prefectural Government Building) / 1-3 MAR Kanazawa Art Hall, Organized by: Kanazawa University 21st-Century COE Program / Ishikawa International Cooperation Research Centre / United Nations University-Institute of Advanced Studies, Supported by: Ishikawa Prefectural Government / City of Kanazawa, Eds : Hayakawa, Kazuichi / Kizu, Ryoichi / Kamata, Naoki
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| 8.
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Okamura, Kazumasa ; Kizu, Ryoichi ; Hayakawa, Kazuichi ; Toriba, Akira
概要:
金沢大学大学院自然科学研究科<br />Proceeding : International Symposium of Kanazawa University 21st-Century COE Program Vol.2(2004),Sch
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edule: February 29(SUN)-March 3(WED), Venue: 29 FEB, Ishikawa Life-Long Learning Center(Former Prefectural Government Building) / 1-3 MAR Kanazawa Art Hall, Organized by: Kanazawa University 21st-Century COE Program / Ishikawa International Cooperation Research Centre / United Nations University-Institute of Advanced Studies, Supported by: Ishikawa Prefectural Government / City of Kanazawa, Eds : Hayakawa, Kazuichi / Kizu, Ryoichi / Kamata, Naoki
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| 9.
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論文
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Tang, Ning ; Taga, Rina ; Hattori, Tetsuyuki ; Toriba, Akira ; Kizu, Ryoichi ; Hayakawa, Kazuichi ; Tamura, Kenji ; Kakimoto, Hitoshi
概要:
金沢大学大学院自然科学研究科<br />国立環境研究所<br />石川県保健環境センター<br />Proceeding : International Symposium of Kanazawa University 21st-Centu
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ry COE Program Vol.2(2004),Schedule: February 29(SUN)-March 3(WED), Venue: 29 FEB, Ishikawa Life-Long Learning Center(Former Prefectural Government Building) / 1-3 MAR Kanazawa Art Hall, Organized by: Kanazawa University 21st-Century COE Program / Ishikawa International Cooperation Research Centre / United Nations University-Institute of Advanced Studies, Supported by: Ishikawa Prefectural Government / City of Kanazawa, Eds : Hayakawa, Kazuichi / Kizu, Ryoichi / Kamata, Naoki
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