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通过逆转录-聚合酶链反应从我国河南省2例重叠感染HCV或HBV/HDV的献血啼中,分离到HBVNS5区的部分cDNA,对其进行序列分析比较,结果表明,河南株HGVNS5工核苷酸与两中国HGV主同源性高于国外代表株(88.5-90.6%),但由核苷酸推导的氨基酸的同源性都无明显的地区性区别。HGVNS5区氨基酸序列较保守,缺乏明显高变区,中国4株HGV在7384位发生了由C→T的变异,从而导致一个人 相似文献
156.
Glucose oxidation modulates anoikis and tumor metastasis 总被引:1,自引:0,他引:1
Kamarajugadda S Stemboroski L Cai Q Simpson NE Nayak S Tan M Lu J 《Molecular and cellular biology》2012,32(10):1893-1907
Cancer cells exhibit altered glucose metabolism characterized by a preference for aerobic glycolysis or the Warburg effect, and the cells resist matrix detachment-induced apoptosis, which is called anoikis, a barrier to metastasis. It remains largely unclear whether tumor metabolism influences anoikis and metastasis. Here we show that when detached from the matrix, untransformed mammary epithelial cells undergo metabolic reprogramming by markedly upregulating pyruvate dehydrogenase (PDH) kinase 4 (PDK4) through estrogen-related receptor gamma (ERRγ), thereby inhibiting PDH and attenuating the flux of glycolytic carbon into mitochondrial oxidation. To decipher the significance of this metabolic response, we found that depletion of PDK4 or activation of PDH increased mitochondrial respiration and oxidative stress in suspended cells, resulting in heightened anoikis. Conversely, overexpression of PDKs prolonged survival of cells in suspension. Therefore, decreased glucose oxidation following cell detachment confers anoikis resistance. Unlike untransformed cells, most cancer cells demonstrate reduced glucose oxidation even under attached conditions, and thus they inherently possess a survival advantage when suspended. Normalization of glucose metabolism by stimulating PDH in cancer cells restores their susceptibility to anoikis and impairs their metastatic potential. These results suggest that the Warburg effect, more specifically, diminished glucose oxidation, promotes anoikis resistance and metastasis and that PDKs are potential targets for antimetastasis therapy. 相似文献
157.
DGGE fingerprinting of bacteria in soils from eight ecologically different sites around Casey Station,Antarctica 总被引:3,自引:0,他引:3
C. W. Chong G. Y. Annie Tan Richard C. S. Wong Martin J. Riddle Irene K. P. Tan 《Polar Biology》2009,32(6):853-860
Bacterial community structures in soils collected from eight sites around Casey Station, Antarctica, were investigated using
denaturing gradient gel electrophoresis (DGGE) of amplified 16S rRNA gene fragments. Higher bacterial diversity was found
in soils from protected or relatively low human-impacted sites in comparison to highly impacted sites. However, the highest
diversity was detected in samples from Wilkes Tip, a former waste disposal site that has been undisturbed for the last 50 years.
Comparison of community structure based on non-metric multidimensional scaling plots revealed that all sites, except the hydrocarbon-contaminated
(oil spill) site, were clustered with a 45% similarity. A total of 23 partial 16S rRNA gene sequences were obtained from the
excised DGGE bands, with the majority of the sequences closely related to those of the Cytophaga–Flexibacter–Bacteroides group. No significant correlation was established between environmental variables, including soil pH, electrical conductivity,
carbon, nitrogen, water content and heavy metals, with bacterial diversity across the eight study sites. 相似文献
158.
Acetylcholine is an important neurotransmitter, and the habenulo-interpeduncular projection is a major cholinergic pathway in the brain. To study the physiological properties of cholinergic transmission in the interpeduncular nucleus (IPN), we used a transgenic mouse line in which the light-gated cation channel ChannelRhodopsin-2 is selectively expressed in cholinergic neurons. Cholinergic axonal terminals were activated by light pulses, and postsynaptic responses were recorded from IPN neurons. Surprisingly, brief photostimulation produces fast excitatory postsynaptic currents that are mediated by ionotropic glutamate receptors, suggesting wired transmission of glutamate. By contrast, tetanic photostimulation generates slow inward currents that are largely mediated by nicotinic acetylcholine receptors, suggesting volume transmission of acetylcholine. Finally, vesicular transporters for glutamate and acetylcholine are coexpressed on the same axonal terminals in the IPN. These results strongly suggest that adult brain "cholinergic" neurons can corelease glutamate and acetylcholine, but these two neurotransmitters activate postsynaptic neurons via different transmission modes. 相似文献
159.
Chronic Helicobacter pylori Infection Does Not Significantly Alter the Microbiota of the Murine Stomach 总被引:1,自引:0,他引:1 下载免费PDF全文
Mai Ping Tan Maria Kaparakis Maja Galic John Pedersen Martin Pearse Odilia L. C. Wijburg Peter H. Janssen Richard A. Strugnell 《Applied microbiology》2007,73(3):1010-1013
We examined the impact of Helicobacter pylori infection on the murine gastric microbiota by culture and terminal-restriction fragment length polymorphism and found that neither acute nor chronic H. pylori infection substantially affected the gastric microbial composition. Interestingly, the total H. pylori burden detected by real-time PCR was significantly higher than that revealed by viable counts, suggesting that the antigenic load sustaining H. pylori-induced gastritis could be considerably higher than previously believed. 相似文献
160.
同地共栖三种鼠耳蝠食性差异及其生态位分化 总被引:1,自引:0,他引:1
2005年9—11月在贵州省安龙县笃山乡暗河村,分析了共栖同一山洞3种鼠耳蝠的形态特征和食性。在体型上,华南水鼠耳蝠体重为(4.46±0.53)g,前臂长为(34.63±1.45)mm;毛腿鼠耳蝠体重为(5.15±1.76)g,前臂长为(35.20±1.07)mm;西南鼠耳蝠体重为(10.94±0.87)g,前臂长为(45.21±1.15)mm。3种鼠耳蝠的体重两两之间差异显著,西南鼠耳蝠与另外2种鼠耳蝠的前臂长相比两两之间差异显著。在食物组成上,华南水鼠耳蝠主要捕食近水面活动的双翅目及其幼虫,体积百分比和频次百分比分别为79.7%和100%;毛腿鼠耳蝠主要捕食双翅目和小型鞘翅目,体积百分比分别占59.6%和28.8%,频次百分比分别为91.3%和80.1%;西南鼠耳蝠的食物组成主要为近地面或在地表活动的鞘翅目步甲科和埋葬虫科昆虫,体积百分比和频次百分比分别为80.8%和100%;3种鼠耳蝠食物组成存在显著差异。结果表明,同地共栖3种鼠耳蝠除了形态结构上出现差异,食物组成也存在明显的差异。据此,推测3种鼠耳蝠可能采取不同的捕食生境和捕食策略,从而导致捕食生态位分离,避免出现激烈竞争,使得3种近缘鼠耳蝠能够同地共栖。 相似文献