Refolding and purification of interferon-gamma in industry by hydrophobic interaction chromatography

A new technology for renaturation with simultaneous purification of the recombinant human interferon-gamma (rhIFN-gamma) in downstream of biotechnology is presented. The strategies to develop the new technology in industry scale were suggested. Based on chemical equilibrium and molecular interactions, the principle of rhIFN-gamma refolding by HPHIC was described. The kind of stationary and mobile phases were evaluated and found the former to contribute to the rhIFN-gamma refolding more than the latter. The extract containing the rhIFN-gamma in gram scale in 7.0 mol L(-1) guanidine hydrochloride solution of 700 mL was directly pumped into a unit of simultaneous renaturation and purification of proteins (USRPP, 10 x 300 mm i.d.) packed by small particle packings of hydrophobic interaction chromatography and a satisfactory recovery of bioactivity and mass of the rhIFN-gamma was obtained. With flow rate 100 mL min(-1) and a gradient elution by only one step in 4h, the purity and specific bioactivity approach to 95% and 8.7 x 10(7) IU(-1) mg, respectively. To evaluate the goodness of the presented new technology in this study, a usual method with the renaturation by dilution method firstly and then purification with a series of LC in literature was employed to compare with each other. The obtained result in terms of purity, recoveries of mass and bioactivity, cost time as well as expenses, the former is much better than the latter. Comparing the total bioactivity of rhIFN-gamma in the extract before to that after the renaturation by the USRPP, the total bioactivity of rhIFN-gamma increased 62-fold.     

Regulation of vascular endothelial growth factor-dependent retinal neovascularization by insulin-like growth factor-1 receptor

Although insulin-like growth factor 1 (IGF-1) has been associated with retinopathy, proof of a direct relationship has been lacking. Here we show that an IGF-1 receptor antagonist suppresses retinal neovascularization in vivo, and infer that interactions between IGF-1 and the IGF-1 receptor are necessary for induction of maximal neovascularization by vascular endothelial growth factor (VEGF). IGF-1 receptor regulation of VEGF action is mediated at least in part through control of VEGF activation of p44/42 mitogen-activated protein kinase, establishing a hierarchical relationship between IGF-1 and VEGF receptors. These findings establish an essential role for IGF-1 in angiogenesis and demonstrate a new target for control of retinopathy. They also explain why diabetic retinopathy initially increases with the onset of insulin treatment. IGF-1 levels, low in untreated diabetes, rise with insulin therapy, permitting VEGF-induced retinopathy.     

应用X光荧光法检测硫的化学位移和研究病毒感染植物中硫状态的改变

应用双晶X光荧光光谱仪研究生理性和病理性植物组织中某些元素的分布特征已有报道。本研究工作中采用日本国东芝厂出品的AFV701型双晶X光荧光光谱仪,测定并比较了植物感染病毒前、后的叶片中,不同硫状态相对比例的改变。应用此仪器首先测定各种标准硫化物硫状态的化学位移数值,在确定标准图谱及可分性之后,再测定感染蚕豆萎蔫病毒(BBWV)、黄瓜花叶病毒(CMV)、芜菁花叶病毒(TuMV)的茄、苋色藜、烟草和萝卜等四种寄主植物的显症病叶中不同硫状态的相对比例。发现应用此技术能明显地区别出病态植物与健康植物中硫状态相对比例的变化差异。     

黄腹角雉的种群数量及其结构研究

1983—1986年在浙江省乌岩岭自然保护区,应用标图法和线路统计法,对野生黄腹角雉种群、数量进行了统计分析。结果表明冬季种群约50只。种群数量有明显的季节变动:繁殖后期数量增加,秋末冬初开始明显下降。黄腹角雉繁殖力低,卵的损失率高,使种群数量上升十分缓慢。成体性比接近1:1,在各样区之间略有差异。在性比偏离1:1较大的样区,亚成体比例较高。     

弱氧化醋杆菌阿拉伯糖醇脱氢酶基因克隆及其在大肠杆菌中的表达

The partial genomic library of Acetobacter suboxydans was constructed using Yeast\| E.coli shuttle plasmid YEp352 as vector.Two positive transformants,designated as DH5α(pAD91) and DH5α(pAD98),were obtained by screening the growth of transformants on the agar plate in which D\|arabitol was used as the sole carbon source.The results of Southern blot and restriction endonuclease analysis showed that the two recombinants are identical.The insert is about 2.3kb.Arabitol dehydrogenase activity assay indic…     

抑制O~6-甲基鸟嘌呤-DNA甲基转移酶活性与肿瘤细胞对亚硝脲药物敏感性关系的研究

80％以上的肿瘤细胞为O~6-甲基鸟嘌吟-DNA甲基转移酶(O~6-MT)活性较高的Mer~+型,能够修复亚硝脲药物(NU)造成的DNA烷化损伤,对NU不敏感。本实验证明,用0.75,0.50和0.25mmol/L甲基亚硝脲(MNU)分别处理Mer~+型的HeLaS3,SMMC-7721和表现Mer~-型特征的Cc801,均能明显降低细胞中O~6-MT活性,从而显著提高了三种细胞对嘧啶亚硝脲和双氯乙亚硝脲的敏感性,提示降低O~6-MT活性是使用NU对Mer~+型肿瘤进行有效治疗的前提。     

Soil organic matter molecular composition and state of decomposition in three locations of the European Arctic

Increased mineralization of the organic matter (OM) stored in permafrost is expected to constitute the largest additional global warming potential from terrestrial ecosystems exposed to a warmer climate. Chemical composition of permafrost OM is thought to be a key factor controlling the sensitivity of decomposition to warming. Our objective was to characterise OM from permafrost soils of the European Arctic: two mineral soils—Adventdalen, Svalbard, Norway and Vorkuta, northwest Russia—and a “palsa” (ice-cored peat mound patterning in heterogeneous permafrost landscapes) soil in Neiden, northern Norway, in terms of molecular composition and state of decomposition. At all sites, the OM stored in the permafrost was at an advanced stage of decomposition, although somewhat less so in the palsa peat. By comparing permafrost and active layers, we found no consistent effect of depth or permafrost on soil organic matter (SOM) chemistry across sites. The permafrost-affected palsa peat displayed better preservation of plant material in the deeper layer, as indicated by increasing contribution of lignin carbon to total carbon with depth, associated to decreasing acid (Ac) to aldehyde (Al) ratio of the syringyl (S) and vanillyl (V) units, and increasing S/V and contribution of plant-derived sugars. By contrast, in Adventdalen, the Ac/Al ratio of lignin and the Alkyl C to O-alkyl C ratio in the NMR spectra increased with depth, which suggests less oxidized SOM in the active layer compared to the permafrost layer. In Vorkuta, SOM characteristics in the permafrost profile did not change substantially with depth, probably due to mixing of soil layers by cryoturbation. The composition and state of decomposition of SOM appeared to be site-specific, in particular bound to the prevailing organic or mineral nature of soil when attempting to predict the SOM proneness to degradation. The occurrence of processes such as palsa formation in organic soils and cryoturbation should be considered when up-scaling and predicting the responses of OM to climate change in arctic soils.     

Genetic Variability of PRNP in Chinese Indigenous Goats

Polymorphism of the prion protein gene (PRNP) is usually associated with scrapie susceptibility or resistance. To determine the variability of PRNP in Chinese indigenous goat breeds, we isolated genomic DNA from goat blood and amplified and sequenced the coding region of the gene. We identified 10 polymorphic sites that gave rise to 28 haplotypes. Clear frequency differences were found between northern and southern breeds and confirmed by genetic distance analysis, except for the Tangshan dairy goat. Phylogeographic analysis supported the idea that northern and southern breeds might be considered separate clusters, except for the Tangshan dairy goat. The finding of significant differences in allele distribution in northern and southern goats, especially if involved in modulating resistance/susceptibility, needs to be carefully considered for the feasibility of selection plans for resistance to scrapie.     

Selecting appropriate methods of knowledge synthesis to inform biodiversity policy

Responding to different questions generated by biodiversity and ecosystem services policy or management requires different forms of knowledge (e.g. scientific, experiential) and knowledge synthesis. Additionally, synthesis methods need to be appropriate to policy context (e.g. question types, budget, timeframe, output type, required scientific rigour). In this paper we present a range of different methods that could potentially be used to conduct a knowledge synthesis in response to questions arising from knowledge needs of decision makers on biodiversity and ecosystem services policy and management. Through a series of workshops attended by natural and social scientists and decision makers we compiled a range of question types, different policy contexts and potential methodological approaches to knowledge synthesis. Methods are derived from both natural and social sciences fields and reflect the range of question and study types that may be relevant for syntheses. Knowledge can be available either in qualitative or quantitative form and in some cases also mixed. All methods have their strengths and weaknesses and we discuss a sample of these to illustrate the need for diversity and importance of appropriate selection. To summarize this collection, we present a table that identifies potential methods matched to different combinations of question types and policy contexts, aimed at assisting teams undertaking knowledge syntheses to select appropriate methods.