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991.
Metabolic activation of 2,4-dinitrobiphenyl derivatives for their mutagenicity in Salmonella typhimurium TA98 总被引:1,自引:0,他引:1
In order to elucidate the mechanisms of mutagenic activation of nitroarenes, we tested the mutagenic potency of 18 kinds of nitroarenes including nitrated biphenyl, fluorene, phenanthrene and pyrene on Salmonella typhimurium TA98 in the absence and presence of S9 mix. The mutagenicities of 2,4-dinitrobiphenyl derivatives and 4-nitrobiphenyl were enhanced by the addition of S9. 2,4,6-Trinitrobiphenyl (3 net rev./10 micrograms without S9) was activated 60-fold by the mammalian metabolic system (181 net rev./10 micrograms with 10% S9). The mutagenic potency of 2,4,2',4'-tetranitrobiphenyl in TA98, TA98NR and TA98/1,8-DNP6 was also enhanced by the addition of 10% S9. But 1-nitropyrene and 1,3-dinitropyrene, which are well-known mutagens and carcinogens, were deactivated to 3% and 0.4%, respectively, by the addition of 10% S9. Separate addition of microsomal and cytosolic fractions slightly activated the mutagenicity of 2,4,6-trinitrobiphenyl, and 2,4,2',4'-tetranitrobiphenyl was activated not only by S9 but also by the cytosolic fraction. 相似文献
992.
Hiroshi Yao Takashi Matsumoto Makoto Hirano Toshihide Kuroki Tetsuyuki Tsutsumi Hideyuki Uchimura Kaoru Nakamura Tatsuo Nakahara Masatoshi Fujishima 《Neurochemical research》1989,14(1):75-79
This study attempted to investigate the possible involvement of the brain stem noradrenergic system in the development of hypertension in spontaneously hypertensive rats. Steady-state norepinephrine, dopamine, serotonin and 5-hydroxyindoleacetic acid concentrations and norepinephrine turnover were determined in the individual brain stem nuclei using high performance liquid chromatography with electrochemical detection. Decreased norepinephrine contents in the nucleus tractus solitarii in spontaneously hypertensive rats compared with Wistar-Kyoto rats at the age of 4, 8, and 16 weeks were demonstrated. In later stages (8 and 16 weeks), increased norepinephrine levels were observed in the nucleus reticularis gigantocellularis, the A1 and A5 areas. Norepinephrine turnover was not different between spontaneously hypertensive rats and Wistar-Kyoto rats in the nucleus tractus solitarii at the age of 4 and 16 weeks and increased in the nucleus reticularis gigantocellularis of spontaneously hypertensive rats at 16 weeks. Our results indicate that altered norepinephrine metabolism in the specific brain stem nuclei, especially the consistently decreased norepinephrine in the nucleus tractus solitarii of spontaneously hypertensive rats, contribute to the development of genetic hypertension. 相似文献
993.
Isolation of 9-hydroxy-delta-tetradecalactone from lipid A of Pseudomonas diminuta and Pseudomonas vesicularis 总被引:1,自引:0,他引:1
A lipid component was isolated from the fatty acid fraction of acid hydrolysates of lipid A derived from Pseudomonas diminuta JCM 2788 and Pseudomonas vesicularis JCM 1477 lipopolysaccharides. By structural analysis of the lipid and its trimethylsilyl and acetyl derivatives by thin-layer chromatography, gas chromatography-mass spectrometry, mass spectrometry, infrared spectrometry and 13C-NMR, it was identified as 9-hydroxy-delta-tetradecalactone. 相似文献
994.
K. Hirayama S. Kawamura T. Mitsuoka† K. Tashiro‡ 《Journal of applied microbiology》1989,67(4):411-415
The faecal floras of two adult (male and female) and one infant (male) giant panda kept at the Ueno Zoo, Tokyo, Japan were examined and shown to be quite different from those of other animals. The predominant bacteria in the adults were Streptococcus (including Enterococcus ) and Enterobacteriaceae, while obligate anaerobes had minor populations. Fastidious anaerobes were not detected. The predominant bacteria in the suckling infant were Lactobacillus and Streptococcus , followed by Bifidobacterium. After the infant began to eat bamboo leaves the number of Lactobacillus decreased and Bifidobacterium became undetectable, whereas Enterobacteriaceae became one of the most predominant flora. The most dominant streptococcus isolated from the female panda was identified as Streptococcus bovis , but those from the male adult and the weaned infant were not identified as any known species. 相似文献
995.
Summary The phenotypes of alpha-1-antitrypsin have been analyzed by isoelectric focusing on polyacrylamide gels in 232 healthy Japanese blood donors and in 240 Japanese patients with chronic liver diseases: 69 with chronic active hepatitis, 122 with liver cirrhosis, 41 with hepatocellular carcinoma and 8 with primary biliary cirrhosis. The liver cirrhosis patients had a gene frequency of 0.07 forPI
*
M3, which was significantly higher (P<0.01) than that (0.03) in blood donors. The gene frequency of PI
*
M3 was significantly increased in cryptogenic liver cirrhosis (P<0.05), and there was a tendency toward an increased frequency of PI
*
M3 in post-transfusion groups, and in primary biliary cirrhosis. There were also tendenciestoward increased frequencies of PI
*
M3 in cryptogenic and post-transfusion groups of patients with chronic active hepatitis. The present study indicates that PI
*
M3 is a genetic or predisposing factor for chronic liver diseases, especially for cryptogenic and/or non A-non B viral chronic liver disease and also for primary biliary cirrhosis. 相似文献
996.
Yukiyoshi Shirasaka Dr. Masatoshi Ito Hideo Tsuda Hideyuki Shiraishi Katsuhiko Oguro Kozoh Mutoh Haruki Mikawa 《Neurochemical research》1990,15(9):869-874
Benzodiazepine receptors and subtypes were examined in El mice and normal ddY mice with a quantitative autoradiographic technique. Specific [3H]flunitrazepam binding in stimulated El mice, which had experienced repeated convulsions, was significantly lower in the cortex and hippocampus than in ddY mice and unstimulated El mice. In the amygdala, specific [3H]flunitrazepam binding in stimulated El mice was lower than in ddY mice. There was a tendency for the [3H]flunitrazepam binding in these regions in unstimulated El mice to be intermediate between that in stimulated El mice and that in ddY mice, but there was no significant difference between unstimulated El mice and ddY mice. [3H]Flunitrazepam binding displaced by CL218,872 was significantly lower in the cortex of stimulated El mice than in that of the other two groups, and in the hippocampus of stimulated than of unstimulated El mice. These data suggest that the decrease in [3H]flunitrazepam binding in stimulated El mice may be due mainly to that of type 1 receptor and may be the result of repeated convulsions. 相似文献
997.
Yoshinari Yamazaki Yumiko Hayashi Masatoshi Arita Tadaharu Hieda Yoichi Mikami 《Applied microbiology》1988,54(10):2354-2360
α-Ionone, α-methylionone, and α-isomethylionone were converted by Aspergillus niger JTS 191. The individual bioconversion products from α-ionone were isolated and identified by spectrometry and organic synthesis. The major products were cis-3-hydroxy-α-ionone, trans-3-hydroxy-α-ionone, and 3-oxo-α-ionone. 2,3-Dehydro-α-ionone, 3,4-dehydro-β-ionone, and 1-(6,6-dimethyl-2-methylene-3-cyclohexenyl)-buten-3-one were also identified. Analogous bioconversion products from α-methylionone and α-isomethylionone were also identified. From results of gas-liquid chromatographic analysis during the fermentation, we propose a metabolic pathway for α-ionones and elucidation of stereochemical features of the bioconversion. 相似文献
998.
By use of pulse-chase exposure of dissociated cells of rat fetal spinal cord or brain to [3H]thymidine (TdR) and unlabeled TdR it has been shown that oligodendroglial precursors which do not express galactocerebroside (GalC) divide first and later differentiate to express GalC. The rate of proliferation of more mature GalC+ oligodendrocytes is considerably lower than that of their GalC- precursors. It has been found that oligodendrocyte precursor cells are extremely sensitive to [3H]TdR irradiation. Exposure to as little as 0.03 microCi/ml for 24 hr proved to be harmful, particularly during a critical period before birth. This critical period corresponded to the peak of division of oligodendrocyte precursor cells. 相似文献
999.
Isolation and Molecular Characterization of Entamoeba nuttalli Strains Showing Novel Isoenzyme Patterns from Wild Toque Macaques in Sri Lanka
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Hiroshi Tachibana Tetsuo Yanagi Meng Feng K. B. Anura T. Bandara Seiki Kobayashi Xunjia Cheng Kenji Hirayama R. P. V. Jayanthe Rajapakse 《The Journal of eukaryotic microbiology》2016,63(2):171-180
We have proposed the revival of the name Entamoeba nuttalli for a virulent ameba strain, P19‐061405, from a rhesus macaque and located it phylogenetically between E. histolytica and E. dispar. As E. nuttalli was originally described for an ameba found in a toque macaque in Sri Lanka, the prevalence and characteristics of Entamoeba species in wild toque macaques were examined. PCR analysis of 227 stool samples from six locations showed positive rates for E. nuttalli, E. dispar, and E. histolytica of 18.5%, 0.4%, and 0%, respectively. Fifteen E. nuttalli strains were cultured successfully from five locations. The 18S ribosomal RNA gene showed only three nucleotide differences in comparison with P19‐061405 strain. In isoenzyme analysis, the pattern of hexokinase in Sri Lankan strains was different from that of P19‐061405 strains and the difference was confirmed by analysis of the genes. Hepatic inoculation of one of the Sri Lankan E. nuttalli strains in hamsters resulted in amebic abscess formation and body weight loss. These results demonstrate that E. nuttalli is prevalent in wild toque macaques and that several characteristics of the strains are unique. We conclude that use of the name E. nuttalli is appropriate for the new Entamoeba species found in nonhuman primates. 相似文献
1000.
Dang My Nhi Nguyen Tien Huy Kaname Ohyama Daisuke Kimura Nguyen Thi Phuong Lan Leo Uchida Nguyen Van Thuong Cao Thi My Nhon Le Hong Phuc Nguyen Thi Mai Shusaku Mizukami Lam Quoc Bao Nguyen Ngoc Doan Nguyen Van Thanh Binh Luong Chan Quang Juntra Karbwang Katsuyuki Yui Kouichi Morita Vu Thi Que Huong Kenji Hirayama 《PLoS neglected tropical diseases》2016,10(2)