固定化嗜热脂肪芽孢杆菌连续合成半乳糖寡糖的研究

利用固定了产β-半乳糖苷酶的嗜热脂肪芽孢杆菌,以乳糖为底物,在纤维床反应器中连续合成半乳糖寡糖(GOS),最高得率为50.7%。在连续反应体系中,研究了底物浓度、pH、反应温度和停留时间对半乳糖寡糖合成的影响,确定最佳反应条件为底物浓度450 g/L、反应温度55℃、pH7.0、停留时间100 min。在连续反应24h后,流加1.5%的D-半乳糖能提高合成GOS的能力,固定化细胞反应体系中连续稳定操作120 h。     

球花石楠离体培养及快速繁殖研究

取球花石楠的不同器官、不同部位的材料进行离体培养及快速繁殖研究。试验结果表明,根部萌蘖条和盆栽大苗的嫩茎为首选外植体,在MS+6-BA 2 mg·L^-1+NAA 0.5 mg·L^-1的培养基上有较高的腋芽萌发率,增殖阶段以MS+6-BA 4 mg·L^-1+NAA 0.1 mg·L^-1培养基上的小苗最多,生长健壮,生根可在1/2 MS+IBA 0.25 mg·L^-1的培养基上进行。分析了生根较低的原因并提出改进措施。     

细胞黏附分子互作网络的构建与分析

借助网络分析可对基因调控、蛋白质互作和信号转导等细胞活动进行全局和局部性质分析.以细胞黏附的蛋白质相互作用为对象,通过数据挖掘和可视化软件构建了整合蛋白介导的黏附分子互作网络,该分子互作网络由156种蛋白质通过690种相互作用相连,其平均节点度为8.66、平均聚集系数为0.24,平均路径长度为2.6.黏附分子互作网络中包含数个功能模块,这些模块涉及网络内部多种分子相互作用的启动与停止,并进一步影响细胞的黏附、迁移和骨架组织.对黏附分子网络进行模体筛选和比较,发现一些数量相对较少、以三元复合物为主要结构的关键模体,同时对各网络模块和模体对细胞黏附的调控作用进行了探讨.     

场景的一致性效应及其机制

有关场景一致性效应的研究发现,人们对与背景语义一致的前景物体的命名、分类、搜索和再认等都快于与背景不一致的物体.和与情境一致的物体相比,与情境不一致的物体在中央顶区等部位,会诱发一个幅度更大的负波(N390).旁海马皮层/旁海马位置区(PHC/PPA)和压部后皮层(RSC)是负责场景加工的重要脑区.场景一致性效应的时间进程可能首先由低空间分辨率(LSF)信息激活眶额皮层(OFC)(130 ms左右)、PHC/PPA和RSC,之后LSF信息与高空间分辨率(HSF)信息在颞叶进行整合.在诸多理论模型中,情境促进模型从生理角度对一致性效应作了较充分的解释.     

Detection of <Emphasis Type="Italic">Xanthomonas oryzae</Emphasis> pv. <Emphasis Type="Italic">oryzae</Emphasis> in seeds using a specific TaqMan probe

Xanthomonas oryzae pv. oryzae is the pathogen that causes bacterial leaf blight in rice. Bacterial leaf blight is the main cause for severe rice underproduction in many countries. However, with conventional methods it is difficult to quickly and reliably distinguish this pathogen from other closely related pathogenic bacteria, especially X. oryzae pv. oryzicola, the causal organism of bacterial leaf streak in rice. We have developed a novel and highly sensitive real-time method for the identification of this specific bacteria based on a TaqMan probe. This probe is designed to recognize the sequence of a putative siderophore receptor gene cds specific to X. oryzae pv. oryzae, and can be identified from either a bacterial culture or naturally infected rice seeds and leaves in only 2 h. The sensitivity of the method is 100 times higher than that of the current polymerase chain reaction (PCR) gel electrophoresis method for diagnosis.     

绿盲蝽腹神经节的解剖结构

【目的】揭示绿盲蝽Apolygus lucorum腹神经节的组成结构。【方法】采用免疫组织化学染色方法,利用突触蛋白抗体对绿盲蝽成虫的腹神经节进行免疫标记,激光共聚焦扫描显微镜扫描照相获得原始数据,用图像分析软件进行标记,构建三维结构模型。【结果】绿盲蝽成虫腹神经节位于腹神经索的末端,与其前方的后胸神经节和中胸神经节紧密融合,形成后部神经节。与脑和胸神经节类似,腹神经节由周围的细胞体和内部的神经髓构成。腹神经节的神经纤维束主要包括位于腹侧的两条纵向神经连索和向两侧发出的9束神经纤维。9束神经纤维连接着9个神经原节,即富含突触联系的神经髓。这些神经原节紧密融合,无明显的边界,最后两节形成膨大的末端腹神经节。两侧的神经原节由横向的神经连锁连接起来。腹神经节外周的细胞体数量较多,排列紧密,大小一致,仅在前端背侧中间和后端腹侧中间位置分别有2个和5个体积较大的细胞体。【结论】本研究结果明确了绿盲蝽腹神经节的结构,为进一步研究昆虫的行为调控及神经系统发育和演化奠定一定的形态学基础。     

Role of the prostaglandin E2/E-prostanoid 2 receptor signalling pathway in TGFβ-induced mice mesangial cell damage

The prostaglandin E2 receptor, EP2 (E-prostanoid 2), plays an important role in mice glomerular MCs (mesangial cells) damage induced by TGFβ1 (transforming growth factor-β1); however, the molecular mechanisms for this remain unknown. The present study examined the role of the EP2 signalling pathway in TGFβ1-induced MCs proliferation, ECM (extracellular matrix) accumulation and expression of PGES (prostaglandin E₂ synthase). We generated primary mice MCs. Results showed MCs proliferation promoted by TGFβ1 were increased; however, the production of cAMP and PGE₂ (prostaglandin E₂) was decreased. EP2 deficiency in these MCs augmented FN (fibronectin), Col I (collagen type I), COX2 (cyclooxygenase-2), mPGES-1 (membrane-associated prostaglandin E1), CTGF (connective tissue growth factor) and CyclinD1 expression stimulated by TGFβ1. Silencing of EP2 also strengthened TGFβ1-induced p38MAPK (mitogen-activated protein kinase), ERK1/2 (extracellular-signal-regulated kinase 1/2) and CREB1 (cAMP responsive element-binding protein 1) phosphorylation. In contrast, Adenovirus-mediated EP2 overexpression reversed the effects of EP2-siRNA (small interfering RNA). Collectively, the investigation indicates that EP2 may block p38MAPK, ERK1/2 and CREB1 phosphorylation via activation of cAMP production and stimulation of PGE₂ through EP2 receptors which prevent TGFβ1-induced MCs damage. Our findings also suggest that pharmacological targeting of EP2 receptors may provide new inroads to antagonize the damage induced by TGFβ1.     

中国和美国红火蚁毒腺生物碱组分的比较分析

【目的】比较两个入侵地红火蚁Solenopsis invicta毒腺生物碱成分及相对含量的地区间差异。【方法】以在中国广东省惠州、 广州、 深圳、 东莞、 珠海和美国阿拉巴马州采集的红火蚁工蚁为材料, 用正己烷溶剂浸提48 h获得浸提液, 将浸提液进行硅胶柱层析分离, 用气相色谱-质谱联用仪（GC-MS）分析其所含的生物碱成分及其相对含量。【结果】红火蚁毒腺生物碱含顺式生物碱组分和反式生物碱组分。通过总离子图对比, 得到了7种顺式生物碱、 8种四氢吡啶和7种反式生物碱, 并计算得到这些组分的相对百分含量。【结论】中国广东省5个地区红火蚁生物碱组成无差别, 相对含量略有差异, 惠州种群和深圳种群差别最大, 其他地区间没有差别。中美两国入侵地的红火蚁种群生物碱成分种类无差别, 其各个组分之间相对含量略有差异, 美国阿拉巴马州种群与中国深圳种群各组分相对含量差别最大, 与中国广州种群差别最小。另外, 在检测的中国广东样品中, 只确认了红火蚁的存在, 提示杂合蚁与黑火蚁还未传入中国。     

Inhibiting gene expression of alpha3 nicotinic receptor in SH-SY5Y cells with the effects on APP metabolism and antioxidation in Alzheimer's disease

In order to examine the effects of alpha3 nicotinic acetylcholine receptor (nAChR) in connection with the pathogenesis of Alzheimer's disease (AD), neuroblastoma (SH-SY5Y) cells were transfected with small interference RNAs (siRNAs) that target specifically towards alpha3 nAChR. The expressions of alpha3 nAChR mRNA and protein were measured by real-time PCR and Western blotting, respectively. The levels of the alpha-form of secreted amyloid precursor protein (alphaAPPs) and total-APP were determined by Western blotting. SH-SY5Y cells transfected with siRNA were then treated with 1muM beta-amyloid peptide (Abeta)(1-42), following which the levels of lipid peroxidation, the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), and the reduction rate of MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] were characterized by utilizing spectrophotometric procedures. As compared to controls, SH-SY5Y cells transfected with siRNA expressed the decreases in the levels of alpha3 nAChR mRNA and protein by 98% and 66% lower levels, respectively; exhibited reduced level of the alphaAPPs; and demonstrated enhanced lipid peroxidation, decreased rate of MTT reduction, and declined activities of SOD and GSH-Px. Inhibited gene expression of the alpha3 nAChR enhanced the toxicity exerted by Abeta. These results indicate that alpha3 nAChR may improve cleavage of APP by alpha-secretase, enhance antioxidation and inhibit the toxicity of Abeta, suggesting that the receptor might play an important role in AD.     

牛疱疹病毒Ⅰ型VP22和猪繁殖与呼吸综合征病毒GP5融合基因DNA疫苗的免疫效应

为了提高表达GP5的猪繁殖与呼吸综合征病毒（PRRSV）DNA疫苗的免疫效应,将具有蛋白转导功能的牛疱疹病毒1型（BHV-1）VP22基因插入到经过修饰具有更好免疫原性的PRRSV修饰型ORF5基因（ORF5M）上游,构建VP22和ORF5M融合表达的真核表达质粒pCI-VP22-ORF5M。经间接免疫荧光试验（IFA）和Westernblot检测证实体外表达后,免疫BALB/c小鼠,检测小鼠免疫后的GP5特异性ELISA抗体、抗PRRSV中和抗体和脾淋巴细胞增殖反应,并与非融合的真核表达质粒pCI-ORF5M进行比较。结果显示,融合表达VP22-GP5的DNA疫苗 pCI-VP22ORF5M诱导的体液免疫和细胞免疫反应均明显高于非融合表达的DNA疫苗pCI-ORF5M,表明蛋白转导相关蛋白BHV-1 VP22能显著增强表达GP5的PRRSV DNA 疫苗的免疫效应,有效发挥了基因免疫佐剂效应;这为研制PRRSV高效DNA疫苗奠定了基础,同时也为其它疾病的高效新型疫苗研究提供了思路。