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61.
Yasuko Hirakawa Hiraku Sasaki Eiichi Kawamoto Hiroki Ishikawa Tetsuya Matsumoto Naoki Aoyama Koh Kawasumi Hiromi Amao 《BMC veterinary research》2010,6(1):52
Background
Chinchillas (Chinchilla laniger) are popular as pets and are often used as laboratory animals for various studies. Pseudomonas aeruginosa is a major infectious agent that causes otitis media, pneumonia, septicaemia enteritis, and sudden death in chinchillas. This bacterium is also a leading cause of nosocomial infections in humans. To prevent propagation of P. aeruginosa infection among humans and animals, detailed characteristics of the isolates, including antibiotic susceptibility and genetic features, are needed. In this study, we surveyed P. aeruginosa distribution in chinchillas bred as pets or laboratory animals. We also characterized the isolates from these chinchillas by testing for antibiotic susceptibility and by gene analysis. 相似文献62.
63.
Yusuke Nakatsu Yasuka Matsunaga Takeshi Yamamotoya Koji Ueda Masa-ki Inoue Yu Mizuno Mikako Nakanishi Tomomi Sano Yosuke Yamawaki Akifumi Kushiyama Hideyuki Sakoda Midori Fujishiro Akihide Ryo Hiraku Ono Tohru Minamino Shin-Ichiro Takahashi Haruya Ohno Masayasu Yoneda Tomoichiro Asano 《Cell reports》2019,26(12):3221-3230.e3
64.
Ohsumi K Matsueda H Hatanaka T Hirama R Umemura T Oonuki A Ishida N Kageyama Y Maezono K Kondo N 《Bioorganic & medicinal chemistry letters》2003,13(14):2269-2272
O-glucuronides and O-glucosides of a series of pyrazoles analogues were synthesized and evaluated for their SGLT inhibitory activity in brush border membrane vehicles (BBMVs) of rat kidney. O-glucosides of certain pyrazole analogues inhibited the transport of [(14)C]-glucose in BBMVs, and induced glucosuria in Wistar rats by intravenous injection. 相似文献
65.
The mechanism of metal-mediated DNA damage by carcinogenic danthron (1,8-dihydroxyanthraquinone) and anthraquinone was investigated by the DNA sequencing technique using 32P-labeled human DNA fragments obtained from the human c-Ha-ras-1 proto-oncogene and the p53 tumor suppressor gene. Danthron caused DNA damage particularly at guanines in the 5'-GG-3', 5-GGGG-3', 5'-GGGGG-3' sequences (damaged bases are underlined) in the presence of Cu(II), cytochrome P450 reductase and the NADPH-generating system. The DNA damage was inhibited by catalase and bathocuproine, suggesting the involvement of H2O2 and Cu(I). The formation of 8-oxo-7,8-dihydro-2'-deoxyguanosine increased with increasing concentration of danthron. On the other hand, carcinogenic anthraquinone induced less oxidative DNA damage than danthron. Electron spin resonance study showed that the semiquinone radical could beproduced by P450 reductase plus NADPH-mediated reduction of danthron, while little signal was observed with anthraquinone. These results suggest that danthron is much more likely to be reduced by P450 reductase and generate reactive oxygen species through the redox cycle, leading to more extensive Cu(II)-mediated DNA damage than anthraquinone. In the case of anthraquinone, its hydroxylated metabolites with similar reactivity to danthron may participate in DNA damage in vivo. We conclude that oxidative DNA damage by danthron and anthraquinone seems to be relevant for the expression of their carcinogenicity. 相似文献
66.
Protective effect of phytic acid on oxidative DNA damage with reference to cancer chemoprevention. 总被引:10,自引:0,他引:10
K Midorikawa M Murata S Oikawa Y Hiraku S Kawanishi 《Biochemical and biophysical research communications》2001,288(3):552-557
Phytic acid (myo-inositol hexaphosphate) is one of the most promising cancer chemopreventive agents. We investigated the mechanism by which phytic acid expresses preventive action to cancer. Phytic acid inhibited the formation of 8-oxo-7,8-dihydro-2'-deoxyguanosine in cultured cells treated with an H2O2-generating system, although it did not scavenge H2O2. Site-specific DNA damage by H2O2 and Cu(II) at GG and GGG sequences was inhibited by phytic acid, but not by myo-inositol. Phytic acid alone did not cause DNA damage and thus, it should not act as a prooxidant. We conclude that phytic acid acts as an antioxidant to inhibit the generation of reactive oxygen species from H2O2 by chelating metals, resulting in chemoprevention of cancer. 相似文献
67.
2,4,6-trinitrotoluene-induced reproductive toxicity via oxidative DNA damage by its metabolite 总被引:5,自引:0,他引:5
Homma-Takeda S Hiraku Y Ohkuma Y Oikawa S Murata M Ogawa K Iwamuro T Li S Sun GF Kumagai Y Shimojo N Kawanishi S 《Free radical research》2002,36(5):555-566
Several epidemiological studies and animal experiments showed that 2,4,6-trinitrotoluene (TNT), a commonly used explosive, induced reproductive toxicity. To clarify whether the toxicity results from the interference of endocrine systems or direct damage to reproductive organs, we examined the effects of TNT on the male reproductive system in Fischer 344 rats. TNT administration induced germ cell degeneration, the disappearance of spermatozoa in seminiferous tubules, and a dramatic decrease in the sperm number in both the testis and epididymis. TNT increased the formation of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) in sperm whereas plasma testosterone levels did not decrease. These results suggest that TNT-induced toxicity is derived from direct damage to spermatozoa rather than testosterone-dependent mechanisms. To determine the mechanism of 8-oxodG formation in vivo , we examined DNA damage induced by TNT and its metabolic products in vitro . 4-Hydroxylamino-2,6-dinitrotoluene, a TNT metabolite, induced Cu(II)-mediated damage to 32 P-labeled DNA fragments and increased 8-oxodG formation in calf thymus DNA, although TNT itself did not. DNA damage was enhanced by NADH, suggesting that NADH-mediated redox reactions involving TNT metabolites enhanced toxicity. Catalase and bathocuproine inhibited DNA damage, indicating the involvement of H 2 O 2 and Cu(I). These findings suggest that TNT induces reproductive toxicity through oxidative DNA damage mediated by its metabolite. We propose that oxidative DNA damage in the testis plays a role in reproductive toxicity induced by TNT and other nitroaromatic compounds. 相似文献
68.
Toshiya Katano Shin-ichi Nakano Osamu Mitamura Haruko Yoshida Hisayuki Azumi Yoshiki Matsuura Yuji Tanaka Hiraku Maezono Yasuhiro Satoh Takeshi Satoh Yuko Sugiyama Yasunori Watanabe Tetsuro Mimura Yuki Akagashi Hiroshi Machida Valentin V. Drucker Irina Tikhonova Olga Belykh Vladimir A. Fialkov Myung-Soo Han Sung-Ho Kang Masahito Sugiyama 《Limnology》2008,9(2):105-114
In Lake Baikal, picocyanobacteria are the most important primary producers during the summer. Freshwater picocyanobacteria
are discriminated into either the phycoerythrin (PE)-rich or the phycocyanin (PC)-rich types according to their pigment composition.
The distributions of these two types of picocyanobacteria were investigated in Barguzin Bay. The PC-rich type accounted for
>98% of the total picocyanobacteria at the station near the shore of the bay where river water flows directly in. In the offshore
area of the lake, all of the picocyanobacteria cells were of the PE-rich type. In addition, the occurrence of the PC-rich
type was restricted to the station, where the attenuation coefficient exceeded 0.25 m−1. Near the shore, where the turbidity was high (>1 NTU), the cell densities of both the PE- and PC-rich types increased away
from the river mouth. This indicates that the PC-rich type cells grow near the shore of the bay where turbidity is high. Since
the PC-rich type could not grow well when cells were incubated in offshore lake water, restricted distribution of the PC-rich
type could also be explained by their growth capability. The present study clearly demonstrated the shift in the pigment type
composition of picocyanobacteria from the coastal to the pelagic zone of Lake Baikal. The co-existence of the two pigment
types probably enables the abundance of the picocyanobacterial community to be stable over a broader range of environmental
conditions than would be possible for a single pigment type. 相似文献
69.
70.
Itadani Hiraku; Wakasugi Tatsuya; Sugita Mamoru; Sugiura Masahiro; Nakazono Mikio; Hirai Atsushi 《Plant & cell physiology》1994,35(8):1239-1244
The nucleotide sequence of a 27,588-bp region of rice mitochondrialDNA was determined. This sequence contains putative genes thatencode initiator methionine tRNA (trnfM), subunits III (nad3)and IV (nad4) of the NADH dehydrogenase complex, and ribosomalproteins S3 (rps3), S12 (rps12) and L16 (rp116). An open readingframe that contains sequences homologous to parts of rps2 andatpA is also present. In addition to these regions, there aremany short sequences with homology to fragments of mitochondrialDNAs from rice or other plants. These sequences may be remnantsof multiple rearrangements of the genome and their presenceseems to explain, in part, the large sizes of the mitochondrialgenomes of higher plants. (Received July 15, 1994; Accepted September 26, 1994) 相似文献