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1.
《DNA Repair》2017
Infliction of DNA damage initiates a complex cellular reaction – the DNA damage response – that involves both signaling and DNA repair networks with many redundancies and parallel pathways. Here, we reveal the three strategies that the simple multicellular eukaryote, C. elegans, uses to deal with DNA damage induced by light. Separately inactivating repair or replicative bypass of photo-lesions results in cellular hypersensitivity towards UV-light, but impeding repair of replication associated DNA breaks does not. Yet, we observe an unprecedented synergistic relationship when these pathways are inactivated in combination. C. elegans mutants that lack nucleotide excision repair (NER), translesion synthesis (TLS) and alternative end joining (altEJ) grow undisturbed in the dark, but become sterile when grown in light. Even exposure to very low levels of normal daylight impedes animal growth. We show that NER and TLS operate to suppress the formation of lethal DNA breaks that require polymerase theta-mediated end joining (TMEJ) for their repair. Our data testifies to the enormous genotoxicity of light and to the demand of multiple layers of protection against an environmental threat that is so common. 相似文献
2.
黑米稻为中国著名的珍稀稻种。黑米不仅富含的蛋白质、氨基酸、维生素以及钙、铁、锌、硒等矿物营养元素,而且还含有具重要天然色素"黑米色素"。由于黑米营养价值高于普通稻米,且富含花色甘类抗氧化色素,是现代食品行业理想的天然抗氧化剂来源。以黑糙米作为研究材料,无水乙醇作为提取溶剂,采用萃取法对黑米色素的提取工艺做了较为全面的研究。试验结果表明:以无水乙醇作为黑米色素萃取剂时,按照料液比(w/v)1∶8,萃取时间60 min,萃取温度80℃,黑米色素提取效果最佳。 相似文献
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P. Bourke D. Ziuzina L. Han P.J. Cullen B.F. Gilmore 《Journal of applied microbiology》2017,123(2):308-324
There is a diverse range of microbiological challenges facing the food, healthcare and clinical sectors. The increasing and pervasive resistance to broad‐spectrum antibiotics and health‐related concerns with many biocidal agents drives research for novel and complementary antimicrobial approaches. Biofilms display increased mechanical and antimicrobial stability and are the subject of extensive research. Cold plasmas (CP) have rapidly evolved as a technology for microbial decontamination, wound healing and cancer treatment, owing to the chemical and bio‐active radicals generated known collectively as reactive oxygen and nitrogen species. This review outlines the basics of CP technology and discusses the interactions with a range of microbiological targets. Advances in mechanistic insights are presented and applications to food and clinical issues are discussed. The possibility of tailoring CP to control specific microbiological challenges is apparent. This review focuses on microbiological issues in relation to food‐ and healthcare‐associated human infections, the role of CP in their elimination and the current status of plasma mechanisms of action. 相似文献
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Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is a multifunctional protein with diverse biological functions in human cells. In bacteria, moonlighting GAPDH functions have only been described for the secreted protein in pathogens or probiotics. At the intracellular level, we previously reported the interaction of Escherichia coli GAPDH with phosphoglycolate phosphatase, a protein involved in the metabolism of the DNA repair product 2-phosphoglycolate, thus suggesting a putative role of GAPDH in DNA repair processes. Here, we provide evidence that GAPDH is required for the efficient repair of DNA lesions in E. coli. We show that GAPDH-deficient cells are more sensitive to bleomycin or methyl methanesulfonate. In cells challenged with these genotoxic agents, GAPDH deficiency results in reduced cell viability and filamentous growth. In addition, the gapA knockout mutant accumulates a higher number of spontaneous abasic sites and displays higher spontaneous mutation frequencies than the parental strain. Pull-down experiments in different genetic backgrounds show interaction between GAPDH and enzymes of the base excision repair pathway, namely the AP-endonuclease Endo IV and uracil DNA glycosylase. This finding suggests that GAPDH is a component of a protein complex dedicated to the maintenance of genomic DNA integrity. Our results also show interaction of GAPDH with the single-stranded DNA binding protein. This interaction may recruit GAPDH to the repair sites and implicates GAPDH in DNA repair pathways activated by profuse DNA damage, such as homologous recombination or the SOS response. 相似文献
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Proteomic changes in the brain of the western painted turtle (Chrysemys picta bellii) during exposure to anoxia 下载免费PDF全文
During anoxia, overall protein synthesis is almost undetectable in the brain of the western painted turtle. The aim of this investigation was to address the question of whether there are alterations to specific proteins by comparing the normoxic and anoxic brain proteomes. Reductions in creatine kinase, hexokinase, glyceraldehyde‐3‐phosphate dehydrogenase, and pyruvate kinase reflected the reduced production of adenosine triphosphate (ATP) during anoxia while the reduction in transitional endoplasmic reticulum ATPase reflected the conservation of ATP or possibly a decrease in intracellular Ca2+. In terms of neural protection programed cell death 6 interacting protein (PDCD6IP; a protein associated with apoptosis), dihydropyrimidinase‐like protein, t‐complex protein, and guanine nucleotide protein G(o) subunit alpha (Go alpha; proteins associated with neural degradation and impaired cognitive function) also declined. A decline in actin, gelsolin, and PDCD6IP, together with an increase in tubulin, also provided evidence for the induction of a neurological repair response. Although these proteomic alterations show some similarities with the crucian carp (another anoxia‐tolerant species), there are species‐specific responses, which supports the theory of no single strategy for anoxia tolerance. These findings also suggest the anoxic turtle brain could be an etiological model for investigating mammalian hypoxic damage and clinical neurological disorders. 相似文献
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组蛋白乙酰化是表观遗传修饰的重要方式,主要受到组蛋白乙酰转移酶(histone acetyltransferases,HATs)和组蛋白去乙酰化酶(histone deacetylase,HDACs)催化.MYST是人类HATs的4大家族之一,包括MOF(males absent on the first),TIP60(tat interacting protein 60 kD),结合ORC1的组蛋白乙酰转移酶(histone acetyltransferase binding to ORC1,HBO1),单核细胞白血病锌指蛋白(monocytic leukemia zinc finger protein,MOZ)和MOZ相关蛋白(MOZ related factor,MORF)等,均具有典型的MYST结构域.MYST介导的乙酰化是重要的翻译后修饰,其催化底物包括组蛋白和非组蛋白,如组蛋白H3,H4,H2A,H2A突变体,以及许多参与DNA代谢、细胞增殖和发育调控的蛋白因子.MYST蛋白家族参与许多细胞的生理过程,本文主要综述其在调节基因转录、DNA损伤修复和肿瘤发生发展等方面的生物学功能. 相似文献
9.
基于上转磷光颗粒的AFP免疫层析定量检测 总被引:1,自引:0,他引:1
目的:建立了上转磷光免疫层析快速定量检测AFP的方法,用于原发性肝癌的诊断。方法:利用上转磷光标记的双抗夹心免疫层析技术检测血清中AFP的含量。将AFP单克隆抗体分别标记上转磷光颗粒并包被硝酸纤维膜,制成免疫层析检测试纸。评价该试纸的灵敏度、特异性和精密度。并通过临床50例血清样本,探讨上转磷光技术与化学发光检测方法的一致性。结果:该方法能在20min内完成,检测灵敏度达5ng/ml。浓度范围从5-1000ng/ml作标准曲线,呈现较好的线性。通过三组平行实验探讨其精密度,变异系数都在10%以内。应用于其它肿瘤标志物如CEA、CA199、AFU和NSE的检测,无交叉反应。与化学发光相比,决定系数R2=0.9692,一致性较好。结论:该方法简便、快速、廉价,可以实现定量,尤其适合基层门诊和体检现场使用。 相似文献
10.
《Saudi Journal of Biological Sciences》2017,24(4):787-796
The current study was aimed to fabricate customized root form dental implant using additive manufacturing technique for the replacement of missing teeth. The root form dental implant was designed using Geomagic™ and Magics™, the designed implant was directly manufactured by layering technique using ARCAM A2™ electron beam melting system by employing medical grade Ti–6Al–4V alloy powder. Furthermore, the fabricated implant was characterized in terms of certain clinically important parameters such as surface microstructure, surface topography, chemical purity and internal porosity. Results confirmed that, fabrication of customized dental implants using additive rapid manufacturing technology offers an attractive method to produce extremely pure form of customized titanium dental implants, the rough and porous surface texture obtained is expected to provide better initial implant stabilization and superior osseointegration. 相似文献