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Authors |
Achievements |
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Prof. Hisato Iwata |
To evaluate the sensitivity and responses to dioxins via aryl
hydrocarbon receptor (AHR) in Baikal seals (Pusa
sibirica),
we constructed an in vitro reporter gene assay system, and
measured the AHR-mediated transactivation potencies by each
dioxin congener. The
results demonstrated that the seal AHR is very sensitive to
2,3,7,8-TCDD, the most toxic dioxin congener.
New!
Eun-Young, Kim, Tomoko Suda, Shinsuke Tanabe,
Valeriy Batoev, Evgeny Petrov, Hisato Iwata
Evaluation of relative potencies for in vitro transactivation of
the Baikal seal aryl hydrocarbon receptor by dioxin-like
compounds
Environ. Sci. Technol., 45(4), 1652-1658
(2011)
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Prof.
Satoru Suzuki |
The prevalence of four different tetracycline-resistance genes,
tetA, tetC, tetH and tetM, in sediments from four aquaculture
farms and their surroundings in the Baltic Sea was monitored by
quantitative polymerase chain reaction (qPCR). The presence of
three additional tetracycline-resistance genes (tetE, tetG and
tetW) was studied qualitatively by standard PCR, and the amount
of bioavailable tetracyclines and total amounts of tetracycline
and oxytetracycline in samples were also measured.None of the
farms were using tetracycline at the time of the sampling and
one of the farms had stopped all antibiotic use six years prior
to the first sampling. Our results showed greater copy numbers
of tetA, tetC, tetH and tetM at the farms compared to pristine
sites and demonstrated the presence of tetE, tetG and tetW genes
in the sediments under aquaculture farms at most sampling times.
However, most resistance genes were not found in samples
collected 200 m from any of the farms. None of the samples
contained any tetracyclines at any of the sampling times,
suggesting that the increase in the prevalence of tetracycline
resistance genes is caused by the persistence of these genes in
the absence of selection pressure. This work is collaboration
product between University of Helsinki and CMES, and the first
author was a visiting scientist at CMES in 2009. Part of this
work was performed at Matsuyama.
New!
Manu Tamminen, Antti Karkman, Andres Lõhmus, Windi Indra
Muziasari,
Hiroyuki Takasu, Shigeki Wada, Satoru Suzuki, Marko Virta.
TETRACYCLINE RESISTANCE GENES PERSIST AT AQUACULTURE FARMS IN
THE ABSENCE OF SELECTION PRESSURE
Environ. Sci. Technol., 45, 386-391 (2011)
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Prof.
Hisato Iwata |
This study demonstrates that the chicken aryl hydrocarbon
receptor (AHR) repressor (AHRR) has the same repressive
capabilities as mammalian and zebrafish AHRRs, but the critical
regions involved in the repressive activity and the mode of
action of repression may be different across species. This paper
is selected as a "Highlighted Article" of this issue.
Jin-Seon Lee, Eun-Young Kim, Koji Nomaru, and Hisato Iwata.
(2011).
Molecular and functional characterization of aryl hydrocarbon
receptor repressor from the chicken (Gallus gallus):
interspecies similarities and differences.
Toxicological Sciences, 119(2), 319–334.
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Assistant Prof.
Kei Nomiyama |
In the present study,
we
determined the residue levels and patterns of PCB and OH-PCB
congeners, and examined correlations between OH-PCB
metabolites and parent PCBs in the blood from eight species
of toothed whales and three species of baleen whales
stranded along the Japanese coast. As the results, it
revealed that the accumulation profiles of OH-PCBs in
cetacean blood are clearly different from the profiles found
in other mammals. This study is the first report to
comprehensively document the accumulation profiles of
OH-PCBs in cetaceans.
Nomiyama, K., Murata, S., Kunisue T., Yamada T.K., Mizukawa
H., Takahashi, S.,
& Tanabe S. (2010).
Polychlorinated Biphenyls and Their Hydroxylated Metabolites
(OH-PCBs) in the Blood of Toothed and Baleen Whales Stranded
along Japanese Coastal Waters.
Environmental Science and Technology, 44(10), 3732-3738.
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Prof.
Hisato Iwata |
We found that the
endangered black-footed albatross is contaminated by high levels
of dioxins, and a xenobiotic metabolizing enzyme, cytochrome
P4501A is induced by the dioxins accumulated in the liver. This
study is the first direct demonstration indicating the impacts
of dioxins in this rare species.
Kubota, A., Watanabe, M.,
Kunisue, T., Kim, E. Y., Tanabe, S., & Iwata, H.
(2010).
Hepatic CYP1A induction by
chlorinated dioxins and related compounds in the endangered
black-footed albatross from the North Pacific.
Environmental Science and
Technology,
44(9), 3559-3565.
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(Away from this site) |
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Prof.
Hisato Iwata |
We clarified the the associations between
genetic polymorphisms of glutathione S-transferases and profiles
of arsenic metabolites in the residents of northern Vietnam.
Agusa, T., Iwata, H., Fujihara, J., Kunito, T., Takeshita, H.,
Minh, T. B., Trang, P.T.K., Viet, P.H., Tanabe, S. (2009):
Genetic polymorphisms of glutathione S-transferase (GST)
superfamily and arsenic metabolism in residents of the Red River
Delta, Vietnam. Toxicology and Applied Pharmacology, 242,
352-362
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Prof.
Takeshi Miura |
Trypsin is a multifunctional factor in spermatogenesis Chiemi
Miura, Takashi Ohta, Yuichi Ozaki, Hideki Tanaka and Takeshi
Miura
Proceedings of the National Academy of Science,
USA. 2009
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Prof.
Hisato Iwata |
We clarified that one of nuclear receptors, the constitutive
androstane receptor (CAR) in seals is highly reactive to
environmental chemicals like PCBs. The methodology
established in the present study is valid for the risk
assessment of chemicals in wildlife.
Sakai, H., Kim, E. -., Petrov, E. A., Tanabe, S., &
Iwata, H. (2009).
Transactivation potencies of baikal seal constitutive
active/androstane receptor by persistent organic pollutants
and brominated flame retardants.
Environmental Science and Technology, 43(16),
6391-6397.
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(Away from this site) |
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Prof.
Takeshi Miura |
Zn is an essential trace element for regulation of
spermatogenesis, such as maintenance, proliferation and
meiosis of germ cells; and sperm motility in Japanese eel.
This is the first report on clarification of the direct
effects of Zn on spermatogenesis in vertebrates.
Yamaguchi S., Miura, C., Kikuchi K., Celino F. T.
Agusa T., Tanabe., Miura T. (2009). Zinc is an essential
trace element for spermatogenesis.
Proceedings of the National Academy of Science, USA.
2009 106:10859-10864
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Global COE Program |
We are pleased to inform you that the second volume of our
series “Interdisciplinary Studies on Environmental
Chemistry” has been published.
http://www.terrapub.co.jp/onlineproceedings/ec/02/index.html
The volume titled “Environmental Research in Asia for
Establishing a Scientist's Network” delivers full papers of
the research presented at the International Symposium held
on November 11-13, 2008 in Ehime University.
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Prof.
Hisato Iwata |
Associations of single nucleotide polymorphisms (SNPs) in As
(+3 oxidation state) methyltransferase (AS3MT) with
the As concentrations in residents from the Red River Delta,
Vietnam are clarified.
Agusa, T., Iwata, H., Fujihara, J., Kunito, T., Takeshita,
H., Minh, T. B., Trang, P.T.K., Viet, P.H., Tanabe, S.
(2009): Genetic polymorphisms in AS3MT and arsenic
metabolism in residents of the red river delta, Vietnam.
Toxicology and Applied Pharmacology, 236(2), 131-141.
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Prof.
Satoru Suzuki |
Tetracycline resistance gene tet(M) was found to
distribute among various environments without drug
contamination, such as Antarctic Adelie penguin intestine
and marine sediment of Pacific Ocean. Report on various
genotyping of tet(M) in these environments is the
first evidence.
Rahman, H.M., Nonaka, L., Tago, R., & Suzuki, S. (2008)
Occurrence of two genotypes of tetracycline (TC) resistance
gene tet(M) in the TC-resistant bacteria in marine
sediments of Japan. Environmental Science and Technology,
42(14), 5055-5061.
→ Abstract (Away from this site)
Rahman, H.M., Sakamoto, K.Q., Nonaka, L., & Suzuki,
S. (2008) Occurrence and diversity of the tetracycline
resistance gene tet(M) in enteric bacteria of
Atrantic Adelie penguins. Journal of Antimicrobial
Chemotherapy, 62(3), 627-628.
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Prof.
Shinsuke Tanabe |
Levels of dioxins and related compounds and PCBs in Baikal
seals have not declined since 1992. Therefore, contamination
and risk by these contaminants are expected to last longer.
Imaeda, D., Kunisue, T., Ochi, Y., Iwata, H., Tsydenova, O.,
Takahashi, S., Amano, M., Petrov, E. A., Batoev, V. B.,
Tanabe, S. (2009). Accumulation features and temporal trends
of PCDDs, PCDFs and PCBs in Baikal seals (Pusa sibirica).
Environmental Pollution, 157(3), 737-747.
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Prof.
Hisato Iwata |
Function of avian metallothionein isoforms is characterized
and a detoxification mechanism of toxic metals is unveiled.
Nam, D. H., Kim, E. Y., & Iwata, H. (2008). Functional
analysis of avian metallothionein isoforms: An
ecotoxicological approach for assessing potential
tolerability to element exposure. Environmental Science and
Technology, 42(24), 9391-9396.
→ Abstract (Away from this site) |
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Global COE Program |
We are pleased to inform you that the first volume of our
series “Interdisciplinary Studies on Environmental
Chemistry” has been published.
http://www.terrapub.co.jp/onlineproceedings/ec/01/index.html
The volume titled “Biological Responses to Chemical
Pollutants” delivers full papers of the research presented
at the International Symposium on Biological Responses to
Chemical Pollutants held on March 6-7, 2008 in Ehime
University. |
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Prof.
Hisato Iwata |
The promoter/enhancer regions in common cormorant CYP1A5
(ccCYP1A5) and chicken CYP1A5 (ckCYP1A5) were functionally
characterized to clarify the induction mechanism of the
avian CYP1A5 by dioxins and to explicate the mechanism of
species differences in dioxin-sensitivity.
Lee, J. -S., Kim, E. -Y., & Iwata, H. (2009): Dioxin
activation of CYP1A5 promoter/enhancer regions from two
avian species, common cormorant (Phalacrocorax carbo)
and chicken (Gallus gallus): Association with aryl
hydrocarbon receptor 1 and 2 isoforms. Toxicology and
Applied Pharmacology, 234(1), 1-13.
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Prof.
Satoru Suzuki |
Original article on genogrouping of marine aquabirnaviruses
published in Journal of Fish Diseases (27, 633-643, 2004)
was ranked at 17th position as highly cited papers between
2004~2007. (When it was updated on Mar. 19, 2008)
Now it has already been renewed, but there were only two
papers by the Japanese including this paper in the best 20
when it was updated on Mar. 19, 2008.
http://www.blackwell-synergy.com/action/showMostCitedArticles?journalCode=jfd
Zhang, C.X. and Suzuki S.(2004): Aquabirnaviruses isolated
from marine organisms form a distinct genogroup from other
aquabirnaviruses. Journal of Fish Diseases, 27(11), 633-643.
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Prof.
Hisato Iwata |
Information on the publication of our articles in
peer-reviewed journals: Russian seals are
contaminated by perfluorochemicals, and their
receptor-mediated effects are speculated.
Ishibashi, H., Iwata, H., Kim, E. Y., Tao, L.,
Kannan, K., Amano, M., Miyazaki, N., Tanabe, S., Batoev, V.
B. and Petrov, E. A. (2008): Contamination and effects of
perfluorochemicals in Baikal seal (Pusa sibirica). 1.
Residue level, tissue distribution, and temporal trend.
Environmental Science & Technology, 42(7), 2295-2301.
→ Abstract (Away from this site)
Ishibashi, H., Iwata, H., Kim, E. Y., Tao, L.,
Kannan, K., Tanabe, S., Batoev, V. B. and Petrov, E. A.
(2008): Contamination and effects of perfluorochemicals in
Baikal seal (Pusa sibirica). 2. Molecular characterization,
expression level, and transcriptional activation of
peroxisome proliferator-activated receptor α. Environmental
Science & Technology, 42(7), 2302-2308.
→ Abstract (Away from this site)
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