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Sukeo Onodera, Masakazu Sugimoto, Tsuyoshi Takagi, Kazuo Tanaka
1999 Volume 45 Issue 1 Pages
1-7
Published: February 28, 1999
Released on J-STAGE: April 14, 2008
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Surface sediments were collected from eight sampling points, representing upper, mid-and downstream regions, of the Tama River, to obtain background information on the polychlorinated dibenzo-p-dioxin/dibenzofuran (PCDD/DF) levels, profiles and transport in this river. The sediment profiles of PCDD/DF were strongly dependent on the sampling points, with total PCDD/DF levels ranging from 27.0 to 231.6pg/g dry weight (mean value, 90.7pg/g) and the I-TEQ values ranging from 0.05 to 2.8pg/g (mean value, 1.2pg/g). Two maxima in the PCDD/DF concentrations were observed for the sediment samples taken from stations 3 (midstream) and 7 (upstream) in this river, although none for the samples from downstream (industrial area). Sediment samples taken from the midstream near waste water discharges and a municipal solid waste (MSW) incinerator plant showed high TEQ values of 0.5 to 1.2 and 13.0pg/g, respectively, indicating a potential PCDD/DF source in this river. In contrast, the PCDD/DF concentrations in the sediment samples taken from five tributaries flowing into the midstream region were very low, indicating no PCDD/DF impact into the studied areas. These data suggest a multiplicity of sources ranging from agricultural activities to urban activities such as emission gas from MSW incinerators and effluents from wastewater treatment plants.
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Takayuki Nakahama, Shigenori Sarutani, Yoshio Inouye
1999 Volume 45 Issue 1 Pages
8-14
Published: February 28, 1999
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Trichloroethylene (TCE) is a highly toxic compound which belongs to the class of volatile halogenated hydrocarbons, which are well-known pollutants of drinking water and the atmosphere. The effects of moderately toxic concentration of TCE on the levels of cytochrome P450 (CYP) isoforms and on their phenobarbital (PB) induction in rats were studied. Monooxygenase activities associated with individual CYP isoforms, i.e., CYP1A, 2B, 2E1 and 3A, were measured in microsomal fractions prepared from both lungs and livers of male and female Wistar rats (7-weeks old). Differences in constitutive levels of CYP isoforms were observed between liver and lung of mock-treated rat ; microsomal CYP2B activity was solely detected in lung while the activities of CYP1A, 2EI and 3A, but not 2B were detected in liver. Among these, the pulmonary CYP2B and hepatic CYP2E1 activities were reduced by TCE-treatment. PB-treatment resulted in the detection of increased levels of hepatic CYP1A and 2E1 and of pulmonary CYP2B activities, and also the appearance of hepatic CYP2B activity. Coadministration of TCE was suppressive against the activities of CYP isoforms except for hepatic CYP2E1 in PB-treated rats. The lowered CYP2B activity in the presence of TCE was accompanied by the reduction in the amount of CYP2B apoprotein.
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Baoxu Zhang, Masahiko Satoh, Chiharu Tohyama
1999 Volume 45 Issue 1 Pages
15-19
Published: February 28, 1999
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To investigate the possible involvement of metallothionein (MT) in acetaminophen (AC)-induced liver damage, MT-I and MT-II gene knock-out transgenic mice (MT-null mice) and wild-type control mice were i.p. treated with AC at a single dose of 250mg/kg and compared. At 24h after AC treatment severe liver damage characterized by necrosis of hepatocytes and increased serum GPT activity was found in MT-null mice while a limited degree of change such as a slight increase in serum GPT activity without necrosis was observed in wild-type mouse liver. MT-null hepatocytes also showed elevated PCNA (proliferating cell nuclear antigen)-positive activity around the necrosis area. AC administration resulted in an increase in lipid peroxidation in MT-null mice, but not in the wild-type mice. The liver in the wild-type mice showed an increased MT amount after AC treatment. These results indicate that MT acts as an endogenous defensive factor against AC-induced hepatotoxicity via oxidative stress.
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Atsushi Takeda, Yuka Kodama, Shoji Okada
1999 Volume 45 Issue 1 Pages
20-23
Published: February 28, 1999
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Brain parenchyma is protected against excess metals by the barrier system in the brain. To evaluate the expression of metallothionein (MT), a protective protein against heavy metals, in the brain parenchyma, zinc sulfate (0.2 or 2μmol) or cadmium chloride (2 or 20nmol) was injected into the left striatum of rats. Seventy-two h later, the MT level in the ipsilateral striatum injected with 0.2μmol of zinc sulfate was not significantly higher than that after injection with vehicle. When the striatum was injected with 2μmol of zinc sulfate, on the other hand, the MT level in the ipsilateral striatum, showing apparent degeneration, was significantly higher than that after injection with vehicle : the former was approximately 1.5 times the latter. In the case of injection with cadmium chloride at doses of 2 and 20nmol, the MT levels in the ipsilateral striatum was approximately twice that after injection with vehicle. The MT level in the contralateral striatum and other brain regions were not affected by injection with either metal salt at any dose. When zinc sulfate of 100μmol/kg body weight, corresponding to the lower dose tested(0.1μmol/g brain), was subcutaneously injected, the hepatic MT level was approximately four times higher than the normal hepatic level. These results suggest that the changes of MT level in the brain were small compared to those observed in the liver.
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Kimiko Hirayama, Akira Yasutake
1999 Volume 45 Issue 1 Pages
24-27
Published: February 28, 1999
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To elucidate the involvement of reactive oxygen in in vivo demethylation of methylmercury(MeHg), the effects of paraquat (PQ) and other reactive oxygen modulators on inorganic-Hg (I-Hg) production in MeHg-administered rats were examined. Rats were intravenously (i.v.) injected with MeHgCl (2mg/kg). After MeHg administration, I-Hg levels time-dependently increased in the liver up to 9h, whereas the renal levels did not change during the first 3h, and then increased up to 24h in a time-dependent manner. PQ stimulated I-Hg production in the liver but not in the kidney, whereas it increased 2-thiobarbituric acid-reactive substance (TBA-RS) levels in both tissues. PQ-induced stimulation of I-Hg production was not further accelerated by an OH· enhancer, such as FeSO
4 or Fe(III)EDTA. Hepatic I-Hg production in MeHg-administered rats (without PQ) was suppressed by NaCN (a potent inhibitor of mitochondrial cytochorome oxidase) but not by desferal or Fe(III) EDTA (an OH· modulalator). These results suggest that hepatic mitochondria may play an important role in in vivo demethylation of MeHg, and that reactive oxygen species other than OH· may participate in it.
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Kazuaki Kawai
1999 Volume 45 Issue 1 Pages
28-36
Published: February 28, 1999
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Since early 1980s Drosophila melanogaster larvae heterozygous for recessive visible markers and those with defective DNA repair capability have been intensively used as simple in vivo testers of mutagenicity of environmental agents. In pallalel with this activity, the somatic tests have recently been deployed as tools for the detection of modifiers of the mutagenicity and understanding of basic mechanisms of the effects. Here, I characterize the somatic systems in relation to the biotransforming ability of promutagens and the outcomes from the mutagenicity tests and review some aspects of the deployment.
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Hideo Miyazaki, Seiji Suzuki, Hiroshi Tsujibo, Katsumi Imada
1999 Volume 45 Issue 1 Pages
37-41
Published: February 28, 1999
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A Ferric-EDTA(Fe-EDTA)-degrading bacterium, strain A-1 was characterized by its physiological properties. The rate of degradation of Fe-EDTA was measured by the titration method and ion chromatography. The former method has the advantage of allowing a greater number of sample measurements of samples at one time. The rate of degradation of Fe-EDTA was higher in a stationary culture than in a shaked one. The optimum pH for the degradation rate was approximately 8.2. Strain A-1 grew in the presence of various kinds of metal-EDTA chelates, but a Na salt, Mg and Ca chelates of EDTA inhibited the growth. Their MICs (minimual inhibitory concentration) were 0.0045, 0.03 and 0.006%, respectively. These characteristics of strain A-1 have similarities to those of strain B-3, but were different from those of Agrobacterium sp. which were reported by Lauff previously (Appl. Environ. Microbiol., 56, 3346 (1990)). All of the detail taxonomic characters indicate that the isolate strain A-1 belongs to a Pseudomonas sp.
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Makoto Nakai, Yukiko Tabira, Yoshikuni Yakabe, Etsuko Tsukamoto, Yasuy ...
1999 Volume 45 Issue 1 Pages
P1-1
Published: February 28, 1999
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Shinobu Kinoshita, Mitsuhiro Wada, Naotaka Kuroda, Kenichiro Nakashima
1999 Volume 45 Issue 1 Pages
P2-2
Published: February 28, 1999
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Atsuko Takeuchi, Toshio Okano
1999 Volume 45 Issue 1 Pages
P3-3
Published: February 28, 1999
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Tomoo Shibahara, Yoshihisa Kato, Koichi Haraguchi, Shinya Yumoto, Yosh ...
1999 Volume 45 Issue 1 Pages
P4-4
Published: February 28, 1999
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Kazumi Sugihara, Kazuhiro Shimomiya, Shigeyuki Kitamura, Shigeru Ohta, ...
1999 Volume 45 Issue 1 Pages
P5-5
Published: February 28, 1999
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Shigeki Shimba, Hideko Sone, Junzo Yonemoto, Masakatsu Tezuka
1999 Volume 45 Issue 1 Pages
P6-6
Published: February 28, 1999
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Akira Hiratsuka, Hiroshi Saito, Kenichiro Hirose, Tadashi Watabe
1999 Volume 45 Issue 1 Pages
P7-7
Published: February 28, 1999
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Yuji Okamoto, Shigeyuki Kitamura, Mitsuhiro Takeshita, Shigeru Ohta
1999 Volume 45 Issue 1 Pages
P8-8
Published: February 28, 1999
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Takafumi Ochi
1999 Volume 45 Issue 1 Pages
P9-9
Published: February 28, 1999
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Yoshiyuki Nakamura, Ayako Hirasawa, Takeshi Honma, Masakuni Degawa
1999 Volume 45 Issue 1 Pages
P10-10
Published: February 28, 1999
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Satoshi Watanabe, Akiko Ishiguro, Shin-ichi Togashi, Masami Ohishi, No ...
1999 Volume 45 Issue 1 Pages
P11-11
Published: February 28, 1999
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Hiroyasu Yamazaki, Yoko Orito, Sachiko Katayama, Aki Kamei, Takako Yam ...
1999 Volume 45 Issue 1 Pages
P12-12
Published: February 28, 1999
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Yasuyuki Fujiwara, Toshiyuki Kaji
1999 Volume 45 Issue 1 Pages
P13-13
Published: February 28, 1999
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Sachiyo Takefuta, Atsushi Takeda, Hiromi Ijiro, Miho Ohnuma, Jinko Saw ...
1999 Volume 45 Issue 1 Pages
P14-14
Published: February 28, 1999
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Yumiko Nakamura, Yukari Tsumura, Yasuhide Tonogai, Tadashi Shibata
1999 Volume 45 Issue 1 Pages
P15-15
Published: February 28, 1999
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Hideaki Kido, Mitsuhiro Wada, Naotaka Kuroda, Masaharu Shironita, Keni ...
1999 Volume 45 Issue 1 Pages
P16-16
Published: February 28, 1999
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Sadahiro Kawazoe, Yuki Tanimoto, Fumie Kurita, Tamio Mizutani
1999 Volume 45 Issue 1 Pages
P17-17
Published: February 28, 1999
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Hideto Jinno, Tamao Ozawa, Nobumitsu Hanioka, Toshiko Tanaka-Kagawa, T ...
1999 Volume 45 Issue 1 Pages
P18-18
Published: February 28, 1999
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Takumi Ishida, Daisuke Maji, Yuko Yoshioka, Yuji Ishii, Kazuta Oguri
1999 Volume 45 Issue 1 Pages
P19-19
Published: February 28, 1999
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Kazuo Asaoka, Tetuo Satoh, Akira Narita
1999 Volume 45 Issue 1 Pages
P20-20
Published: February 28, 1999
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Yoshihisa Kato, Koichi Haraguchi, Shinya Yumoto, Tomoo Shibahara, Hiro ...
1999 Volume 45 Issue 1 Pages
P21-21
Published: February 28, 1999
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Tomoyuki Odani, Tsuyoshi Nakanishi, Akiko Matuyama, Norio Itoh, Keiich ...
1999 Volume 45 Issue 1 Pages
P22-22
Published: February 28, 1999
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Tomoki Kimura, Isami Fujita, Tsuyoshi Nakanishi, Norio Itoh, Norio Mut ...
1999 Volume 45 Issue 1 Pages
P23-23
Published: February 28, 1999
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Atsuko Adachi, Sokichi Takagi, Tomoko Komiyama, Tomoko Tanaka, Maki Na ...
1999 Volume 45 Issue 1 Pages
P24-24
Published: February 28, 1999
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Hitoshi Ueno, Koji Oishi, Tomoyuki Kubota, Yasuyoshi Sayato, Katsuhiko ...
1999 Volume 45 Issue 1 Pages
P25-25
Published: February 28, 1999
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Kazuhito Watanabe, Naomi Akagi, Masato Usuki, Maki Yamada, Noriyuki Us ...
1999 Volume 45 Issue 1 Pages
P26-26
Published: February 28, 1999
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Toshiko Tanaka-Kagawa, Hideto Jinno, Nobumitsu Hanioka, Tetsuji Nishim ...
1999 Volume 45 Issue 1 Pages
P27-27
Published: February 28, 1999
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Kenzo Yamanaka, Akira Hasegawa, Hirotaka Sonoki, Mikio Hoshino, Shoji ...
1999 Volume 45 Issue 1 Pages
P28-28
Published: February 28, 1999
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Kazuo Asaoka, Yasushi Sakamoto, Kazuyuki Yano
1999 Volume 45 Issue 1 Pages
P29-29
Published: February 28, 1999
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Mariko Tachikawa, Takasi Aburada, Masakatsu Tezuka, Ryoji Sawamura
1999 Volume 45 Issue 1 Pages
P30-30
Published: February 28, 1999
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Sawako Miyajima, Chika Yamamoto, Yasuyuki Fujiwara, Toshiyuki Kaji, Fu ...
1999 Volume 45 Issue 1 Pages
P31-31
Published: February 28, 1999
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Naomi Kudo, Erika Suzuki, Kohtaro Ohmori, Yoichi Kawashima
1999 Volume 45 Issue 1 Pages
P32-32
Published: February 28, 1999
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Tetsuya Murakami, Masaki Watanabe, Masakatsu Tezuka
1999 Volume 45 Issue 1 Pages
P33-33
Published: February 28, 1999
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Yasuji Hojo, Yasuko Asano, Yuko Tonan
1999 Volume 45 Issue 1 Pages
P34-34
Published: February 28, 1999
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Yasuhiro Ishibashi, Yasuhiro Tabira, Yoshinobu Joh, Yuji Takao, Shinya ...
1999 Volume 45 Issue 1 Pages
P35-35
Published: February 28, 1999
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Ayako Fukuda, Ryuichi Kurogi, Kenji Tasaki, Takumi Ishida, Yuji Ishii, ...
1999 Volume 45 Issue 1 Pages
P36-36
Published: February 28, 1999
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Shinya Kohra, Nobuaki Tominaga, Yoshinori Mitsui, Yuji Takao, Yasuhiro ...
1999 Volume 45 Issue 1 Pages
P37-37
Published: February 28, 1999
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Fumi Dakeyama, Jun-ichi Nishikawa, Jun Goto, Koichi Saito, Masayoshi I ...
1999 Volume 45 Issue 1 Pages
P38-38
Published: February 28, 1999
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Yuji Takao, Ho Chul Lee, Yasuhiro Ishibashi, Shinya Kohra, Nobuaki Tom ...
1999 Volume 45 Issue 1 Pages
P39-39
Published: February 28, 1999
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Katsuhiko Saido, D.L. Daubaras, Olga Zaborina, A.M. Chakrabarty
1999 Volume 45 Issue 1 Pages
P40-40
Published: February 28, 1999
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Kiyomatsu Hashizume, Chitose Toda, Teruyo Yasui, Hideo Nagano, Tsutomu ...
1999 Volume 45 Issue 1 Pages
P41-41
Published: February 28, 1999
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Sokichi Takagi, Atsuko Adachi, Chiho Ikeda, Norie Fukao, Emi Yoshii, T ...
1999 Volume 45 Issue 1 Pages
P42-42
Published: February 28, 1999
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