Construction of an immunoconjugate targeting tissue factor and its effect on colorectal cancer cells

AIM: To construct a recombinant eukaryotic expression vector pcDNA3.1(+)-hFVII-LC+hIgG1-Fc, and to produce and purify the immunoconjugate hFVII-LC+hIgG1-Fc protein. METHODS: The target sequences were amplified by RT-PCR from hepatic tissue and lymphocyte RNA, and cloned into eukaryotic expression vector pcDNA3.1(+). After confirmed by restriction endonuclease digestion and DNA sequencing, the recombinant plasmid was transfected into CHO-K1 cells by lipofectamine 2000. The transfectant clones were selected by G418 screening. The positive monoclonals were grown in CHO-K1 serum-free medium Excel 301 and the culture medium was collected. The hFVII-LC+hIgG1-Fc protein was purified by affinity Ni-NTA resin. The immunoconjugate was identified by ELISA with tissue factor (TF) affinity and specificity. Induction of NK cell-mediated antibody-dependent cell cytotoxicity(ADCC) was examined in HT-29 colorectal cancer cell line. RESULTS: Human liver tissue and lymphocytes from Han population were used as template for amplification of hFVII-LC and hIgG1-Fc DNA fragments, which were confirmed by sequencing and were exactly the same as those GenBank reported. The eukaryotic expression vector pcDNA3.1(+)-hFVII-LC+hIgG1-Fc was successfully constructed, and 1.3 mg of hFVII-LC+hIgG1-Fc protein could be prepared from 1 liter of Excel 301 serum-free culture medium through Ni-NTA affinity chromatography. The immunoconjugate was specially bound to TF and induced a significant ADCC response in HT-29 cells. CONCLUSION: The human hFVII-LC+hIgG1-Fc recombinant plasmid and the hFVII-LC+hIgG1-Fc immunoconjugate are obtained, which provide the basis for further study of cancer-targeted therapy.     

Inactivation of Antinutritive Factors in Soya Bean by Proteolytic Enzymes

１ＩｎｒｏｄｕｃｔｉｏｎＩｔｈａｓｌｏｎｇｂｅｅｎｋｎｏｗｎｔｈａｔｓｏｙｂｅａｎｓｃｏｎｔａｉｎａｎｕｍｂｅｒｏｆｍａｊｏｒａｎｔｉ－ｎｕｔｒｉｔｉｏｎａｌｆａｃｔｏｒｓ（ＡＮＦｓ）Ｔｈｅｐｒｅｓｅｎｃｅｏｆｗｈｉｃｈｌｉｍｉｔｓｔｈｅｎｕｔｒｉｔ...     

Inactivation of Antinutritional Factors in Paseolus Vulgris by Proteases and Their Combinations with α-Deglycosidase

Aseries of in vitro trials was carried out to examine the capacity of eight proteolytic enxymes,which are either of bacterial or of fungal origins,and their combinations with a-deglycosidase in denaturing the activity of lectin and trypsin inhibitors in Paseolus vulgris,seed type “processor”,under the similar conditions to those of the gut.Znzymes,P3 and P4,were the most effective of hydrolyisis of trypsin inhibitory activity.After two hours incubation,trypsin inhibitory activity was reduced to 50 and 40% of the original value by P3 and P4 respectively.The rests of enzymes had little effects.Ompared with trypsin inhibitors,lectin was more resistant to hydrolysis.Only P4 reduced it by 26% of the original value.Pre-incubation with α-deglycosidase at its optimum conditions for one hour had no significant benefits for the tested proteases.     

树干输注黄叶清矫治果树黄叶病研究

因缺铁所造成的黄叶病,是果树常见的生理病害,在我国西北、华北等地发生普遍.发病果园病株率在20%以上,严重的甚至达80%,据在邯郸市郊和各县区的调查,梨发病株率达95%,苹果发病株率60%,桃病株率80%.     

渔区和谐社会建设中平安渔业建设的对策与建议

和谐渔区是和谐社会的重要组成部分,而平安渔业建设对于渔区和谐社会的构建至关重要,渔业专业合作经济组织、渔区社会保障体系以及政策性渔业保险制度三个方面的政策研究对于大力推进平安渔业建设具有较强的紧迫性和现实性.     

水果黄瓜日光温室无公害栽培技术要点

水果黄瓜又称迷你黄瓜、小黄瓜等。该品种具有果面光滑易清洗．口感清香脆甜．不含苦味素等特点．适于做水果鲜食，市场前景广阔。我所近几年先后引进了10余种水果黄瓜品种进行品比试验．从中筛选出适于我市大棚栽培的中农19号、京研迷你二号2个水果黄瓜品种。现将其栽培要点介绍如下：     

山区小流域不同海拔和坡位土壤养分分布及相关性分析

通过对河北省易县观坐岭小流域不同海拔和坡位土壤有机质、速效氮、速效磷、速效钾测定分析,得出了该小流域土壤在不同海拔和坡位的肥力状况。结果表明：随海拔降低,土壤有机质和速效氮含量有增加趋势,增幅分别为40%和35%;土壤速效磷和速效钾的变化比较复杂,主要与土壤母质有关。不同坡位土壤养分表现出向下汇集的趋势,下坡位土壤养分含量高于上坡位和中坡位养分含量,但有机质变化趋势相反,是人为活动的影响结果。相关分析结果表明,海拔与土壤有机质、速效氮和速效钾呈显著负相关,与速效磷不相关;各养分含量间,土壤有机质、速效氮、速效钾之间分别呈相关关系,速效磷与速效氮相关显著,与速效钾无相关性。在不同坡位上,土壤养分间的差异不显著。     

微波消解法快速测定土壤中有机质的含量

报道了用微波消解取代油浴消解或灼烧法来测定土壤中有机质的含量,详细讨论了微波消解法的有关测定条件.该法和传统的重铬酸钾油浴法相比,具有快速、经济、重复性好等优点,值得在相关行业中推广应用.     

冬小麦不同生长类型群体超高产的中期栽培调控

以黄淮冬麦区种植面积较大的普通小麦半冬性品种温麦6号(穗数型)、徐州25(中间型)为试验材料, 采用不同措施于拔节前形成群体规模和特征有较大差异且有代表性的大、中、小三类群体, 拔节后(即中期)对各类群体进行4种不同施氮量处理, 重点研究不同类型群体中期施氮肥的调控效应. 结果如下: 不同类型群体在中期因苗合理施氮可达     

太阳能杀虫灯物联网研究现状与展望

太阳能杀虫灯在农业趋光性害虫受灯光引诱并接触金属网时释放高压脉冲电流杀灭害虫,可有效减少施用农药造成的环境污染和食品安全问题。本文介绍了利用无线传感器网络技术提升太阳能杀虫灯在农业迁飞性趋光害虫防治领域的应用效果,明确提出了一种新型农业物联网——太阳能杀虫灯物联网。首先,从杀虫灯在国内农业生产中的应用研究现状出发,总结了杀虫灯在林果、水稻和蔬菜等作物生产种植中的部署特点和杀虫工作时段分布情况;其次,分析了现有联网型太阳能杀虫灯节点的产品特点和杀虫灯物联网研究现状;然后,结合太阳能杀虫灯的能量采集方式、田间部署特点,综合分析了基于太阳能能量采集方式的传感器网络研究现状和基于启发式的传感器网络节点部署研究现状;最后,探讨了太阳能杀虫灯物联网的节点部署、能量预留管理、虫害爆发区域边界定位、虫情数据抗干扰传输等关键研究问题,并对太阳能杀虫灯物联网在农业生产中的应用进行了总结和展望。