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961.
Alpha-lipoic acid (LA) has recently been reported to afford protective effects in neurodegenerative disorders. However, the
mechanisms underlying LA-mediated neuroprotection remain to be investigated. This study was undertaken to determine whether
LA treatment could increase endogenous antioxidants and phase 2 enzymes in cultured human neuroblastoma SH-SY5Y cells, and
whether such increased cellular defenses could afford protection against cytotoxicity induced by neurotoxicants. Incubation
of SH-SY5Y cells with micromolar concentrations of LA for 24 h resulted in a significant increase in the levels of reduced
glutathione (GSH) and NAD(P)H:quinone oxidoreductase 1 (NQQ1) in a concentration-dependent fashion. Treatment of the cells
with LA also led to an increased mRNA expression of γ-glutamylcysteine ligase catalytic subunit (GCLC) and NQO1. To determine
the protective effects of the LA-induced cellular defenses on neurotoxicant-elicitedl cell injury, SH-SY5Y cells were pretreated
with LA for 24 h and then exposed to acrolein, 4-hydroxy-2-nonenal (HNE), H2O2 and the peroxynitrite generator, 3-morpholinosydnonimine (SIN-1). We observed that LA pretreatment of SH-SY5Y cells led to
a marked protection against acrolein, HNE, H2O2 and SIN-1-mediated cytotoxicity, as detected by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium reduction assay. Taken
together, this study demonstrates for the first time that LA can induce GSH and NQO1 in cultured human neuroblastoma cells
and LA-upregulated cellular defenses are accompanied by a markedly increased resistance to cytotoxicity induced by various
neurotoxicants. The results of this study may have important implications for the neuroprotective effects of LA. 相似文献
962.
Efforts in optimizing reducing agents, cysteine-HCl.H2O and sodium sulfide in order to attain satisfactory responses during acetic acid fermentation have been carried out in this study. Cysteine-HCl.H2O each with five concentrations (0.00-0.50 g/L) was optimized one at a time and followed by sodium sulfide component (0.00-0.50 g/L). Response surface methodology (RSM) was used to determine the optimum concentrations of cysteine-HCl.H2O and sodium sulfide. The statistical analysis showed that the amount of cells produced and efficiency in CO conversion were not affected by sodium sulfide concentration. However, sodium sulfide is required as it does influence the acetic acid production. The optimum reducing agents for acetic acid fermentation was at 0.30 g/L cysteine-HCl.H2O and sodium sulfide respectively and when operated for 60 h cultivation time resulted in 1.28 g/L acetic acid production and 100% CO conversion. 相似文献
963.
George D Friedman M Allen H Argiriadi M Barberis C Bischoff A Clabbers A Cusack K Dixon R Fix-Stenzel S Gordon T Janssen B Jia Y Moskey M Quinn C Salmeron JA Wishart N Woller K Yu Z 《Bioorganic & medicinal chemistry letters》2008,18(18):4952-4955
Evaluation of hit chemotypes from high throughput screening identified a novel series of 2,4-disubstituted thieno[2,3-c]pyridines as COT kinase inhibitors. Structural modifications exploring SAR at the 2- and 4-positions resulting in inhibitors with improved enzyme potency and cellular activity are disclosed. 相似文献
964.
Nie Z Perretta C Erickson P Margosiak S Lu J Averill A Almassy R Chu S 《Bioorganic & medicinal chemistry letters》2008,18(2):619-623
A series of macrocyclic derivatives has been designed and synthesized based on the X-ray co-crystal structures of pyrazolo[1,5-a] [1,3,5]triazines with corn CK2 (cCK2) protein. Bioassays demonstrated that these macrocyclic pyrazolo[1,5-a] [1,3,5]triazine compounds are potent CK2 inhibitors with K(i) around 1.0 nM and strongly inhibit cancer cell growth with IC(50) as low as approximately 100 nM. 相似文献
965.
Wang Hong Xu Wei Zheng Yong Bing Xiang Zhi Xian Ruan Jia Rong Cheng Qi Dai Yu Tang Gao Xiao Ou Shu 《BMJ (Clinical research ed.)》2004,328(7451):1285
Objective To evaluate the association of intake of soya food, a rich source of phytoestrogens, with the risk of endometrial cancer.Design Population based case-control study, with detailed information on usual soya food intake over the past five years collected by face to face interview using a food frequency questionnaire.Setting Urban Shanghai, China.Participants 832 incident cases of endometrial cancer in women aged of 30 to 69 years diagnosed during 1997-2001 and identified from the Shanghai Cancer Registry; 846 control women frequency matched to cases on age and randomly selected from the Shanghai Residential Registry.Main outcome measures Odds ratios for risk of endometrial cancer in women with different intakes of soya foods.Results Regular consumption of soya foods, measured as amount of either soya protein or soya isoflavones, was inversely associated with the risk of endometrial cancer. Compared with women with the lowest quarter of intake, the adjusted odds ratio of endometrial cancer was reduced from 0.93 to 0.85 and 0.67 with increasing quarter of soya protein intake (P for trend 0.01). A similar inverse association was observed for soya isoflavones and soya fibre intake. The inverse association seemed to be more pronounced among women with high body mass index and waist:hip ratio.Conclusion Regular intake of soya foods is associated with a reduced risk of endometrial cancer. 相似文献
966.
在广西象州中泥盆统东岗岭组壳相含泥质石灰岩中发现一个海星口面化石 ,定名为Devonasterguangxiensissp .nov .。该种中盘较大 ,腕长且直 ,下缘板发育 ,口角板肥大 ,略尖 ,与美国标本Devonastereucharis(Hall)相比 ,有一定的区别。海星化石与东岗岭组常见化石Actinopteria(双壳类 )和Atrypa(腕足类 ) 相似文献
967.
受干扰长白山阔叶红松林林分结构组成特征及健康距离评估 总被引:10,自引:1,他引:9
通过样地调查对不同干扰方式产生的过伐天然林、次生白桦林和人工落叶松林等群落的结构组成进行分析和分类探讨,并选取能够表征结构完整性和稳定性的一些指标因子,利用健康距离法对长白山阔叶红松林区的森林生态系统健康进行了评估实践,结果按顺序依次为:原始阔叶类0.14<结构转换型0.23<结构保留型0.32<结构破坏型0.33<严重干扰类型0.44<次生白桦林0.53<人工落叶松林0.68.以期对阔叶红松林生态系统的恢复和区域林业可持续发展提供参考. 相似文献
968.
Tian X.L. Cao L.X. Tan H.M. Zeng Q.G. Jia Y.Y. Han W.Q. Zhou S.N. 《World journal of microbiology & biotechnology》2004,20(3):303-309
The populations of endophytic fungi and actinomycetes from four rice cultivars in the Panyu district (Site 1) and Wushan district
(Site 2) in Guangdong province, South China, were studied. The preponderant endophytic fungi and actinomycetes isolated belonged
to Fusarium and Streptomyces respectively. The incidence of Streptomycetes griseofuscus ranged from 36.1 to 69% out of all the different rice cultivars from the two sites. It is the commonest population of endophytic
actinomycetes, and constituted the greatest part of all the antagonistic communities. The distributions of endophytic fungi
and actinomycetes in roots and leaves were different, endophytic fungi from leaves were diverse, some were organ-specific.
More diverse endophytic actinomycetes were isolated from roots than from leaves. The endophytic fungi isolated from rice in
Site 2 were more diverse than that in Site 1. The diversity of the endophytic actinomycetes, however, was less than that in
Site 1. Acid soil in Site 2 is ideal for the growth and colonization of fungi while the alkaline soil in Site 1 is better
for the growth and colonization of actinomycetes. The results suggested that differences in the chemical composition of soil
could influence the endophytic microbial communities of rice plants. The endophytic fungi and actinomycetes isolated from
poor-growing seedlings and susceptible rice cultivars were more abundant than that the disease-resistant counterparts. In
the dual culture and activity detection of the metabolites, 41.2% of all the isolated endophytic fungi showed antagonism to
rice pathogens. Fifty percent of all the isolated endophytic actinomycetes were antagonistic to those pathogens. The percentage
of Streptomyces griseofuscus and hygroscopicus reached 55.4 and 21.4% of all the active actinomycetes.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
969.
Liu Q He X Liu Y Du B Wang X Zhang W Jia P Dong J Ma J Wang X Li S Zhang H 《Biochemical and biophysical research communications》2008,377(3):775-779
Oxidative damage is an important mechanism in X-ray-induced cell death. Radiolysis of water molecules is a source of reactive oxygen species (ROS) that contribute to X-ray-induced cell death. In this study, we showed by ROS detection and a cell survival assay that NADPH oxidase has a very important role in X-ray-induced cell death. Under X-ray irradiation, the upregulation of the expression of NADPH oxidase membrane subunit gp91phox was dose-dependent. Meanwhile, the cytoplasmic subunit p47phox was translocated to the cell membrane and localized with p22phox and gp91phox to form reactive NADPH oxidase. Our data suggest, for the first time, that NADPH oxidase-mediated generation of ROS is an important contributor to X-ray-induced cell death. This suggests a new target for combined gene transfer and radiotherapy. 相似文献
970.