BALB/c小鼠肺组织中氧化及抗氧化系统的动态研究

为探讨BALB/c小鼠正常生理状况下肺组织中的氧化及抗氧化系统的动态变化规律,采用分光光度计法分别测定了肺组织中的黄嘌呤氧化酶（xanthine oxidase,XOD）活性、丙二醛（malondialdehyde,MDA）含量、超氧化物歧化酶（superoxide dismutase,SOD）活性变化。结果表明,在第3、6、7、12天BALB/c小鼠肺组织的XOD活性、MDA含量、SOD活性均无显著差异（P＞0.05）。说明生理状态下,BALB/c小鼠肺组织中自由基的产生与清除的酶系统之间维持动态平衡。     

牛巴贝斯虫新疆株MSA-2c基因的克隆表达及其重组蛋白免疫原性

本试验将新疆株牛巴贝斯虫的MSA-2c基因克隆,并构建重组质粒pGEX-4T-2/MSA-2c.利用大肠杆菌原核表达系统进行外源蛋白的表达,并成功诱导出GST-MSA-2c融合蛋白.通过优化诱导条件,得到了较高的可溶性表达;利用亲和层析技术纯化后的重组蛋白皮下免疫试验小鼠.间接ELISA检测发现,免疫接种56 d后,抗重组蛋白的抗体效价达到1∶220 000以上.用获得的抗血清进行Western-blot试验,可获得清晰的免疫反应条带.结果表明,本试验所表达的MSA-2c蛋白与文献报道的目的蛋白相符,并具有免疫原性.同时本试验也为建立以MSA-2c重组蛋白作为抗原的血清学诊断体系奠定了基础.     

牛巴贝斯虫GST-MSA-2c融合蛋白间接ELISA血清学诊断方法的建立

[目的与方法]在优化表达牛巴贝斯虫GST-MSA-2c融合蛋白和建立ELISA反应条件的基础上,进-步探讨牛巴贝斯虫GST-MSA-2c融合蛋白及其所建立的ELISA检测方法的特异性,从而建立牛巴贝斯虫GST-MSA-2c融合蛋白间接ELISA血清学检测方法.[结果]牛巴贝斯虫GST-MSA-2c融合蛋白间接ELISA检测方法能排除GST的干扰,与其它梨形虫病无交叉反应,与牛巴贝斯虫巢式PCR检测方法的阳性符合率为96;.[结论]所建立的GST-MSA-2c融合蛋白间接ELISA血清学检测方法重复性好、特异性强、灵敏度高.这是国内首次利用重组蛋白抗原建立的牛巴贝斯病血清学诊断方法,为大规模地进行牛巴贝斯虫病的流行病学调查和血清学诊断提供有效的技术手段.     

家蚕细胞色素C基因的克隆及其蛋白在家蚕凋亡细胞中的释放

 【目的】细胞色素C是线粒体凋亡路径上的关键因子,通过家蚕细胞色素C基因的克隆和其蛋白在家蚕凋亡细胞中的释放研究,为家蚕细胞凋亡的研究奠定基础。【方法】利用生物信息学和分子生物学方法克隆家蚕细胞色素C基因,通过紫外线照射诱导家蚕细胞凋亡,应用流式细胞仪和Western-blotting检测家蚕凋亡细胞的线粒体膜电位变化和细胞色素C的释放。【结果】在家蚕中克隆了一个含有细胞色素C保守结构域的同源基因,该基因cDNA长570 bp,有3个外显子,开放阅读框（open reading frame,ORF）长324 bp,编码108个氨基酸,存在参与细胞凋亡时与下游凋亡蛋白酶激活因子（Apaf－1）相互作用的保守关键位点;紫外线诱导家蚕胚胎细胞BmE-SWU1凋亡后12 h,细胞线粒体跨膜电位明显下降,同时检测到了细胞色素C由线粒体向细胞质释放。【结论】在家蚕细胞凋亡中可能存在细胞色素C由线粒体释放的路径。     

猪流感病毒A/swine/Guangdong/2/2012(H1N1)毒株攻毒BALB/c小鼠细胞因子动态变化的研究

为了测定H1N1亚型猪流感病毒(swine influenza virus,SIV)对小鼠的致病性,本试验对A/swine/Guangdong/2/2012(H1N1)株SIV HA基因进行克隆及遗传分析,并将SIV尿囊液经鼻腔感染6周龄BALB/c小鼠,观察感染后小鼠的一般状况、器官系数和组织病理学变化,在病毒感染后第1、3和7天使用荧光定量PCR测定小鼠肺脏、脾脏、脑组织中7种细胞因子mRNA的表达量,研究其对小鼠的致病特性。结果显示,该病毒属于经典SIV,病毒经鼻腔感染后可引起小鼠活动减少、采食量降低,但无咳嗽和死亡;病理组织学变化为肺间隔较正常组织明显增厚,毛细血管明显扩张充血,周围肺泡腔呈代偿性肺气肿;小鼠肺脏、脾脏组织样本中IFN-α、IFN-β、IP-10、IL-1β、TNF-α、IRF-3和IL-10 mRNA含量在感染后第3天均显著升高(P<0.05),而脑组织样本中IL-1β和IL-10在小鼠攻毒后第3和7天均显著上调(P<0.05)。     

Chinese urban migrants' sense of place: Emotional attachment,identity formation,and place dependence in the city and community of Guangzhou

In this paper, we study urban migrants' sense of place in Guangzhou, China, focusing on the structural relations between place attachment, identification and dependence as the three key place dimensions. Through both quantitative structural equation modelling and qualitative analysis of in‐depth interviews data, our research suggests that migrants' sense of place demonstrates complex relationships between the three registers of emotional attachment, identity formation and functional dependence. The construction of sense of place is also related to the personal experiences of living as urban ‘outsiders’. Our research also reveals a striking difference between the city and community levels in terms of the ways in which migrants' sense of place is constructed. Urban migrants tend to exploit the functional utilities of microscopic urban spaces to meet their demands for recreation, education and socialisation. On the other hand, their sense of place to the city is largely compromised by their attachment to the hometown and conditioned by their personal identification to the city.     

The membrane‐type estrogen receptor G‐protein‐coupled estrogen receptor suppresses lipopolysaccharide‐induced interleukin 6 via inhibition of nuclear factor‐kappa B pathway in murine macrophage cells

The female sex hormone estrogen exerts anti‐inflammatory effects. The G‐protein‐coupled estrogen receptor (GPER) has been recently identified as a novel membrane‐type estrogen receptor that can mediate non‐genomic estrogenic effects on many cell types. We previously demonstrated that GPER inhibits tumor necrosis factor alpha‐induced expression of interleukin 6 (IL‐6) through repression of nuclear factor‐kappa B (NF‐κB) promoter activity using human breast cancer cells. Although several reports have indicated that GPER suppresses Toll‐like receptor‐induced inflammatory cytokine expression in macrophages, the molecular mechanisms of the inhibition of cytokine production via GPER remain poorly understood. In the present study, we examined GPER‐mediated inhibition of IL‐6 expression induced by lipopolysaccharide (LPS) stimulation in a mouse macrophage cell line. We found that the GPER agonist G‐1 inhibited LPS‐induced IL‐6 expression in macrophage cells, and this inhibition was due to the repression of NF‐κB promoter activity by GPER. G‐1 treatment also decreased the phosphorylation of inhibitor of κB kinases. Among the mitogen‐activated protein kinases, the phosphorylation of c‐jun N‐terminal kinase (JNK) was increased by G‐1. These findings delineate the novel mechanism of the inhibition of LPS‐induced IL‐6 through GPER‐activated JNK‐mediated negative regulation of the NF‐κB pathway in murine macrophage cells, which links anti‐inflammatory effects to estrogen.     

Effects of Different Milk Samples on Sensitization in BALB/c Mice

In order to study the allergenicity of camel milk,cow milk and human milk,sixty BALB/c mice were randomly divided into β-lactoglobulin (β-lg) group (positive control group),cow milk group,camel milk group,human milk group and blank group (negative control group). Each group of mice received 1 mg/g BW samples and 0.3 μg/g cholera toxin (CT) per week,while mice in control group were received PBS and CT. After six weeks of intragastric administration,some allergic symptoms,the serum specific immunoglobulin E (IgE) and immunoglobulin G1 (IgG1) levels,plasma histamine levels and vascular permeability were detected. The results showed that the body weight of mice in camel milk,human milk and blank groups were normally increased,while that in β-lg and cow milk groups tended to slow down. The serum-specific IgE,IgG1 levels and histamine level in β-lg and cow milk groups were extremely significantly higher than blank group (P<0.01),the vascular permeability was increased,and the allergy symptoms were obvious. While the specific IgE and IgG1 levels of camel milk group were extremely significantly lower than cow milk group (P<0.01),but there were no significant difference with human milk group (P>0.05),and the allergy symptoms were mild. This study showed that the sensitization of camel milk was lower than cow milk,and similar to human milk.     

郏县红牛SREBP-1c基因84 bp缺失突变的检测及其对6个生长性状的影响

旨在研究牛SREBP-1c基因内含子7区域84bp缺失的遗传多态性及其对生长性状的影响。本试验以中国地方品种郏县红牛共计441头个体为实验动物,通过DNA测序技术和琼脂糖凝胶电泳方法检测该区域缺失突变的多态性。结果发现,在该突变位点检测到2种基因型:WW和WD型,等位基因W和D频率分别为0.8651和0.1349。He、Ne和PIC值都很低,说明在本突变位点遗传多态性不够丰富。该突变位点处于Hardy-Weinberg平衡状态(P0.05)。该位点的多态性与郏县红牛6个生长性状指标关联分析显示,郏县红牛WD基因型个体在12、18、24月龄的体质量和胸围显著高于WW基因型个体(P0.01或P0.05),基因型WD个体在18、24月龄的体斜长显著高于WW基因型个体(P0.05),基因型WD个体在18月龄的平均日增体质量显著高于WW基因型个体(P0.01)。初步认为WD型是提高黄牛体质量和体尺指标性状的有利基因型。本研究结果表明,黄牛SREBP-1c基因内含子7区域84bp缺失位点可作为郏县红牛生长性状的潜在分子育种标记,具有很大的研究价值。