SARS-CoV GDH株N蛋白全长基因克隆及其可溶性表达

目的构建SARS冠状病毒N蛋白的原核表达质粒,诱导重组蛋白表达并纯化,鉴定其抗原性。方法以我国SARS冠状病毒GDH株总RNA为模板,采用RT-PCR技术扩增N蛋白的全长基因,TA克隆后测序。构建pET-23d的N基因表达载体,用IPTG诱导目的蛋白表达,利用硫酸铵沉淀、分子筛层析及离子交换层析纯化重组蛋白,免疫印迹鉴定重组蛋白。结果RT-PCR扩增出1269bpSARS冠状病毒N蛋白的基因片段,其序列分析结果与SARS-CoVGD01、BJ01株的同源性为99.92%;该基因在大肠杆菌表达系统中高效表达,占可溶性蛋白的33.57%,表达产物为非融合的可溶性蛋白,Westernblot结果显示重组N蛋白具有良好的抗原性;纯化后重组N蛋白纯度为92.9%。结论成功构建了SARS冠状病毒N蛋白的重组表达质粒,并在大肠杆菌中以非融合蛋白的形式得到高效的可溶性表达,为SRAS的诊断和疫苗的研制奠定了基础。     

诺氟沙星缓释片的初步研究

本文初步研究了诺氟沙星缓释片的处方组成。并对不同处方进行了体外溶出试验,实验结果表明：本品的体外释药可维持12h以上且体外溶出符合一级动力学过程。     

对硝基苯乙醚的合成

目的：研究对硝基苯乙醚的合成方法。方法：以三乙胺-氯苄为相转移催化剂催化合成对硝基苯乙醚。结果：采用本方法简化工艺流程。缩短了生产周期,节约了能源,降低了生产成本。结论：有利于工业化生产,具有良好的应用前景。     

Functional significance of the signal transduction pathways Akt and Erk in ovarian follicles: in vitro and in vivo studies in cattle and sheep

Background

The intracellular signalling mechanisms that regulate ovarian follicle development are unclear; however, we have recently shown differences in the Akt and Erk signalling pathways in dominant compared to subordinate follicles. The aim of this study was to investigate the effects of inhibiting Akt and Erk phosphorylation on IGF- and gonadotropin- stimulated granulosa and theca cell function in vitro, and on follicle development in vivo.

Methods

Bovine granulosa and theca cells were cultured for six days and stimulated with FSH and/or IGF, or LH in combination with PD98059 (Erk inhibitor) and/or LY294002 (Akt inhibitor) and their effect on cell number and hormone secretion (estradiol, activin-A, inhibin-A, follistatin, progesterone and androstenedione) determined. In addition, ovarian follicles were treated in vivo with PD98059 and/or LY294002 in ewes on Day 3 of the cycle and follicles were recovered 48 hours later.

Results

We have shown that gonadotropin- and IGF-stimulated hormone production by granulosa and theca cells is reduced by treatment with PD98059 and LY294002 in vitro. Furthermore, treatment with PD98059 and LY294002 reduced follicle growth and oestradiol production in vivo.

Conclusion

These results demonstrate an important functional role for the Akt and Erk signalling pathways in follicle function, growth and development.     

The impact of transportation infrastructure on bicycling injuries and crashes: a review of the literature

Background  

Bicycling has the potential to improve fitness, diminish obesity, and reduce noise, air pollution, and greenhouse gases associated with travel. However, bicyclists incur a higher risk of injuries requiring hospitalization than motor vehicle occupants. Therefore, understanding ways of making bicycling safer and increasing rates of bicycling are important to improving population health. There is a growing body of research examining transportation infrastructure and the risk of injury to bicyclists.     

Genetic Immunization Maps T Cell (Auto)Immune Responses to Self Antigens Homologous to Exogenous Proteins

Genetic immunization represents a new tool for investigating physiological and pathological immune responses. Here we used genetic immunization with naked DNA to study the immune relevance of aminoacid sequence homologies by evaluating the outcome of immunization to a viral protein homologous to an HLA molecule. The viral protein was Balf2, a protein of Epstein-Barr virus (EBV) that shares aminoacid sequence homology with the HLA allele DRB1*0801. After genetic immunization of BALB/c mice with a construct encoding Balf2, we analyzed T cell responses of immunized mice. We found that cross-reactive proliferative and cytotoxic responses were raised to the homologous sequence as expressed by HLA-DRB1*0801. Furthermore, preferential secretion of Th1-type pro-inflammatory cytokines occurred. This strategy can allow rapid screening of interactive immune networks involving aminoacid sequence homologies between organisms.