C1qa deficiency in mice increases susceptibility to mouse hepatitis virus A59 infection

BackgroundMouse hepatitis virus (MHV) A59 is a highly infectious pathogen and starts in the respiratory tract and progresses to systemic infection in laboratory mice. The complement system is an important part of the host immune response to viral infection. It is not clear the role of the classical complement pathway in MHV infection.ObjectivesThe purpose of this study was to determine the importance of the classical pathway in coronavirus pathogenesis by comparing C1qa KO mice and wild-type mice.MethodsWe generated a C1qa KO mouse using CRISPR/Cas9 technology and compared the susceptibility to MHV A59 infection between C1qa KO and wild-type mice. Histopathological and immunohistochemical changes, viral loads, and chemokine expressions in both mice were measured.ResultsMHV A59-infected C1qa KO mice showed severe histopathological changes, such as hepatocellular necrosis and interstitial pneumonia, compared to MHV A59-infected wild-type mice. Virus copy numbers in the olfactory bulb, liver, and lungs of C1qa KO mice were significantly higher than those of wild-type mice. The increase in viral copy numbers in C1qa KO mice was consistent with the histopathologic changes in organs. These results indicate that C1qa deficiency enhances susceptibility to MHV A59 systemic infection in mice. In addition, this enhanced susceptibility effect is associated with dramatic elevations in spleen IFN-γ, MIP-1 α, and MCP-1 in C1qa KO mice.ConclusionsThese data suggest that C1qa deficiency enhances susceptibility to MHV A59 systemic infection, and activation of the classical complement pathway may be important for protecting the host against MHV A59 infection.     

玉米基因雄性不育双杂合保持系的选育研究

本研究从1982年开始,选用玉米ms1、ms2和ms10三个雄性核不育基因以及易位断点与相应ms基因紧密连锁的T4-6b、T9-10a、T4-10f和T6-10（5519）四个易位系作为基础材料，采用细胞遗传技术育成若干个骨干自交系的基因雄性不育双杂合保持系。至今，已选育出黄早四和Mo17背景的ms2基因杂合保持系。保持系与ms2基因不育系杂交，子代     

皮质醇对黄颡鱼成鱼吞噬细胞和补体活性的影响

采用皮质醇混饲投喂的方法．模拟自然条件下的慢性应激,研究皮质醇对黄颡鱼咸鱼吞噬细胞呼吸暴发和血清补体旁路溶血活性（ACH50）的影响。研究结果与结论如下。皮质醇混饲投喂可使血清皮质醇浓度持续显著升高,各周对照组血清皮质醇含量均无显著性差异,证明采用皮质醇混饲投喂的方法可模拟自然慢性应激情况下的血清皮质醇浓度持续显著升高。从第2周开始头肾吞噬细胞的呼吸暴发功能显著下降（P〈0．05）,证明皮质醇对头肾吞噬细胞的杀菌能力产生显著抑制作用。10mg／kg剂量组,ACH50在投喂第2、第5、第6周显著低于对照组（P〈0．05）,100mg／kg剂量组,ACH50从第2周开始一直都极显著低于同期对照组（P〈0．01）,证明皮质醇显著抑制血清补体旁路溶血活性,且血清皮质醇浓度越高其抑制作用越强。     

hrp基因关键调控因子HrpG在水稻白叶枯病菌和条斑病菌中的交叉互补性研究

 水稻白叶枯病菌(Xanthomonas oryzae pv. oryzae, Xoo)和条斑病菌(X. oryzae pv. oryzicola, Xoc)在非寄主烟草上产生过敏反应(HR)和在寄主水稻上具有致病性,是由hrp致病岛决定的,其中HrpG为关键调控因子。Xoo和Xoc侵染水稻途径和在水稻上产生病害症状的不同,是否与hrpG基因有关,还不清楚。本研究利用反向遗传学方法获得了Xoo和Xoc的hrpG突变体PΔhrpG和RΔhrpG,并用hrpG_Xoo基因和hrpG_Xoc基因分别互补上述2个突变体,获得了相应的互补菌株。致病性测定结果显示,PΔhrpG和RΔhrpG突变体丧失了在水稻上的致病性和在非寄主烟草上产生HR的能力,而hrpG_Xoo基因和hrpG_Xoc基因可分别互补上述突变体至野生型水平。利用GUS报告基因检测基因启动子活性发现,hrpG_Xoo和hrpG_Xoc的启动子活性没有显著差别;RT-PCR和Western杂交结果显示,hrpG基因交叉互补菌株中HrpG调控的下游基因hrpX、hpaR、hrcT、hpa2和hrpD6的表达没有差异,且III型分泌系统分泌蛋白Hpa2的分泌性没有受到影响。这些结果表明,稻黄单胞菌hrpG基因可在Xoo和Xoc中交叉互置,位于其上游和下游的调控途径可能相似,而决定Xoo和Xoc在水稻上的侵染途径以及所致病害症状差异可能与hrpG基因位点无关。     

C5a受体颉颃剂及其在动物疾病模型治疗中的研究进展

C5a受体是人和动物体内补体系统的重要组成部分,与C5a结合后介导了众多生物学效应,参与了许多疾病的发生、发展,并在多种病变中起重要作用,如器官缺血再灌注损伤、急性肺损伤、脓毒血症、类风湿性关节炎、肾小球肾炎等疾病。如何抑制C5a受体的生物活性,从而减轻炎症反应一直是免疫学研究的热点问题。文章着重介绍了C5a受体颉颃剂及其在动物疾病模型治疗中的研究进展。     

High stocking density produces crowding stress altering some physiological and biochemical parameters in gilthead seabream, Sparus aurata, juveniles

High stocking density has been shown to produce a wide variety of effects on cultured fish populations, such as alterations in behavior and poor feed utilization, resulting in mortality and poor growth. High stocking density has also been reported to produce chronic stress and mobilization of energy sources in fish. There are few studies focusing on the effect of high stocking density on one of the most important marine fish species for Mediterranean aquaculture, gilthead seabream (Sparus aurata). Consequently, this study investigates the effect of high stocking density on juveniles of this species, focusing on effects of stocking density on growth, biochemical composition, immune status and hematology.The results of this study showed that high stocking density produced a chronic stress situation. Plasma cortisol levels increased up to 16.25 ng ml–1 in fish held at high stocking; this value was 4 fold that of fish held at low stocking; density (3.91 ng ml–1 ). As a consequenceof this stressful situation, there was both haemoconcentration and a decrease in alternative complement pathway (ACP), an important component of the immune system of fish (from 167.23 U ml–1 down to 146.37 U ml–1). Haematocrit, haemoglobin concentration and red blood cell count were significantly higher in fish held at high stocking density (43.87%, 10.76 9dl–1 and 3.36 ×106 mm–3, respectively) compared with those fish held at low stocking density (37.21%, 9.32 g/dlg–1 and 2.82 ×106 mm–3, respectively).In addition, high stocking density produced a decrease in hepatosomatic index (from 2.26 down to 2.04) and altered liver fatty acid composition. Oleic acid (18: 1n-9) decreased in liver total lipids of fish held at high stocking density and arachidonic acid (20: 4-n6) and n-3 high unsaturated fatty acids (n-3 HUFA) were reduced in liver polar lipids of those fish. These alterations reflect the effect of stocking density on lipid metabolism to help meet the increased energy demand.     

中草药添加剂对生长肥育猪免疫功能的影响研究

 选用20 kg左右的“杜长大”三元杂交猪120头,分成对照组、中药组、中药+西药组,每组4个重复,进行饲养试验。每期实验结束前,每组采集8头猪血样,测定生长育肥猪血清中免疫球蛋白IgG,IgA,IgM和补体C₃,C₄的含量。结果表明:在20～30 kg,30～70 kg和70～110 kg阶段,与对照组相比,中药组、中+西组猪的血清IgG水平,分别提高了23.75%（P<0.05）和18.49%（P<0.05）,17.66%（P<0.05）和13.93%（P<0.05）,14.79%（P<0.05）和11.87%（P<0.05）;IgM水平,分别提高了25.04%（P<0.05）和14.99%（P<0.05）,22.81%（P<0.05）和15.18%（P<0.05）,5.79%（P>0.05）和4.23%（P>0.05）;IgA水平,分别提高了9.71%（P>0.05）和0.57%（P>0.05）,16.92%（P<0.05）和7.60%(P>0.05),15.01%（P<0.05）和7.23%（P>0.05）; C₃水平,分别提高了12.16%（P<0.05）和14.19%（P<0.05）,15.87%（P<0.05）和17.46%（P<0.05）,14.29%（P<0.05）和21.43%（P<0.05）;C₄水平,分别提高了13.51%（P<0.05）,5.02%（P<0.05）,6.67%（P<0.05）.研究结果提示,中草药添加剂对生长育肥猪体液免疫功能的影响,不仅促进免疫球蛋白的生成,而且还促进补体的生成,从而改善机体的体液免疫功能。     

优势互补 共存共荣

从图书馆的教育功能和服务职能看纸质文献和数字文献的优势互补。     

对进一步发挥多媒体在教学中的作用的思考

从介绍多媒体技术入手，阐述在教学中应用多媒体技术带来的效应，总结了当前在教学中应用多媒体技术尚存在的不足之处。进而提出进一步发挥多媒体技术在教学中的作用的对策建议，突出主张多媒体教学和传统教学的共处、结合和竞争，倡导在竞争和互补中推动多媒体教学的发展。