口服携带细胞因子基因的减毒沙门氏菌对小鼠肿瘤的预防作用

将真核表达载体EGFPN1，pCMVhIL-12,pCMVhGM-CSF,pCMVmIL-12和pMCMVmGM-CSF分别导入减毒鼠伤寒沙门氏菌SL3261中，扩增后经由胃管饲予BALB／c和C57BL/6小鼠，6周后用Lewis肺癌细胞和4T1乳腺癌细胞对上述小鼠进行攻击。在小鼠的肝脏、脾脏、肾脏、小肠和肿瘤等组织器官中均可观察到绿色荧光蛋白的表达和相应真核表达载体的整合。小鼠血清中相应的细胞因子水平升高，CD8^ /CD4^ 比较增大，细胞免疫功能增强。各实验组肿瘤的生长较对照组缓慢，部分小鼠肿瘤消退，小鼠生存时间明显延长。该研究为减毒沙门氏菌作为口服基因治疗载体用于肿瘤的预防和治疗提供了实验依据。     

雏鸭混合感染基因A型和基因C型鸭甲肝病毒研究

研究了2013年四川地区某鸭场暴发的基因A型鸭甲肝病毒(DHAV-A)和基因C型鸭甲肝病毒(DHAV-C)的混合感染病例.疾病发生于20~25日龄雏鸭,发病率25%~30%,死亡率为20%~30%,临死前出现明显的神经症状,病死雏鸭肝脏肿大,出血.利用双重RT-PCR从病死雏鸭的肝脏组织中同时检测出DHAV-A和DHAV-C.这是四川省养鸭密集区第一次发现雏鸭混合感染DHAV-A和DHAV-C的情况.此外,对2009~2012年四川省各养鸭密集区鸭甲肝炎流行情况做了调查.一共从四川省养鸭密集区采集312份疑似鸭肝炎样本中检测出120份鸭甲型肝病毒性肝炎.其中基因C型鸭肝炎阳性率为75%,基因A型鸭肝炎仅为25%,未发现基因A型和基因C型混合感染情况.结果说明2009~2012年我省鸭病毒性肝炎以基因C型鸭甲肝病毒为优势病原.2013年,开始出现DHAV-A和DHAV-C混合感染病例.因此如何采取有效措施应对其危害,这应该引起养鸭界及相关部门的高度重视.     

读懂疫苗那些事

正近日,山东非法经营疫苗案件引起公众对疫苗的关注:什么是疫苗?有何作用?疫苗有几类?疫苗不经冷链运输会有什么后果?担心接种的疫苗无效要不要补种?我们—起来读懂疫苗那些事。什么是疫苗?有何作用?疫苗是将病原微生物(如细菌、立克次氏体、病毒等)及其代谢产物,经过人工减毒、灭活或利用基因工程     

七种情况暂时别要宝宝

<正>一位产妇满怀欣喜地期待宝宝出生,可没想到,孩子生下后却发现是唇腭裂(俗称兔唇)。探究原因时才发现,原来她孕前3个月时曾患过"风疹"。门诊中,经常有孕妇问我:"吃了紧急避孕药还是怀了,这宝宝能要吗?""怀孕时吃了感冒药,孩子会不会有事?"等问题。我的回答是,如果妈妈在孕前出现以下一些状况,会影响到宝宝的发育。1.有病毒感染、发热者。怀孕前有过不明原因的全身瘙痒、风团、荨麻疹等"过敏"症状;近期患     

麻疹病毒CC47疫苗测序分析及与其他A基因型病毒株比较

对长春-47(CC47)麻疹病毒减毒活疫苗即CC47疫苗进行测序分析,并与其他A基因型病毒株进行了比较。通过RT-PCR法扩增了6个编码基因,用双脱氧链终止法对产物进行自动测序。对结果进行比较分析发现,CC47疫苗有13个特有的氨基酸改变分别位于N,P和L蛋白,可以看做是该疫苗株的"疫苗标签"。通过构建系统发生树,分析了11株麻疹病毒的亲缘关系。本研究完善了CC47疫苗基因组信息,提供了对麻疹流行进行监测和对病毒减毒基因学基础进行进一步研究的潜在目标。     

华东师范大学1988年初甲肝暴发流行的资料分析

1988年初全校共有急性病毒性肝炎病人228例,发病率为1.93%。168例入病房隔离治疗。本文从流行病学、临床特点和甲肝特异性诊断(血清抗—HAV-IgM)等方面的资料分析,证实与全市甲肝疫情相符,为一起由生食不洁毛蚶引起的同源性甲肝暴发流行。本次甲肝预后良好,92.73%的病人在3月内获得临床痊愈。     

OPV疫苗液体剂型稳定性影响因素分析

 分析了温度、反复冻融、冷链运输过程对口服脊髓灰质炎减毒活疫苗(OPV)滴度的影响,检测结果显示OPV分别在37℃条件下放置3d,25℃放置14d,-20℃放置36个月、反复冻化35次,感染性滴度均无明显变化.在冷链条件下运输,其感染性滴度无明显变化.液体剂型的稳定性优于糖丸剂型(t=3.2043,P<0.01).     

免疫沉淀法分离纯化感染细胞保的甲肝病毒RNA

本研究采用抗血清（多抗血清）沉淀甲肝病毒，并用盐酸胍－酸性酚，氯仿一生法分离纯化病毒ＲＮＡ。此方法能排除非病毒ＲＮＡ的污染，操作简单，要求条件较低，ＲＮＡ的纯度和完整性都较好。     

Specific anti-tumor effect induced by attenuated <Emphasis Type="Italic">Salmonella typhimurium</Emphasis> vaccine expressing extracellular region of vascular endothelial growth factor receptor 2

The purposes of this research were to study the stable expression of exogenous gene encoding therapeutic protein in attenuated Salmonella typhimurium, observe the metabolism of oral gene vaccine carried by attenuated Salmonella typhimurium in BALB/c mouse, and investigate the feasibility of prevention and treatment of tumors by the recombinant bacteria. Recombinant plasmid pcDNA3.1＋ VEGFR2（n1-7） was transformed into competent attenuated Salmonella typhimuriurn SL3261 to develop oral DNA vaccine SL3261-pcDNA3.1＋VEGFR2（n1-7）. To observe whether the exogenous gene can be expressed in the recombinant bacteria, PCR was performed to amplify the CMV promoter of the eukaryotic expression vector as the proof of stable expression of exogenous protein; transmission elec- tron microscopy （TEM） was applied to observe the morphology of the recombinant bacteria to confirm that the exogenous gene has no impact on the growth of the bacteria, and then BALB/c mice were immunized with the gene vaccine. After inoculation of the gene vaccine, the recombinant bacteria SL3261 could be detected in the tissues such as small intestine, colon, liver and spleen. And then, mice in each group were challenged with tumor cells. The results of animal experiment showed that tumor growth of the mice in experimental group was inhibited and survival time of immunized mice was prolonged compared with control groups. A higher lymphocyte infiltration in tumors from animals treated with DNA vaccine was observed. Immunohistochemical analysis of tumor samples revealed an enhanced accumulation of CD8^＋ cytotoxic T lymphocytes, as well as an increase in CD4^＋ cells in the tumore of animals treated with the oral gene vaccine compared to tumors from control group mice. UI- trestructure of the tumor tissue showed that tumor cells in the samples of the immunized mice were well-differentiated. Our research confirmed that the exogenous gene can be stably expressed in the attenuated Salmonella typhimurium and has no impact on the growth of the r