稳定、高效表达肝细胞生长因子的中国仓鼠卵巢细胞系的构建

目的:构建hHGF-pCDNA3.1表达载体,在中国仓鼠卵巢细胞中获得具有生物学活性的重组人肝细胞生长因子蛋白的高效、稳定表达。方法:RT-PCR扩增人肝脏中hHGF全长cDNA片段,克隆入pCDNA3.1( )真核表达载体中,构建hHGF-pCD-NA3.1重组质粒并转染中国仓鼠卵巢细胞,经筛选得到了高效、稳定表达hHGF的细胞克隆,采用RT-PCR和ELISA方法检测hHGF在中国仓鼠卵巢细胞中的表达。结果:酶切及测序结果表明重组质粒构建正确,RT-PCR显示细胞的rhHGF mRNA呈现高水平,ELISA检测hHGF在细胞中的分泌性表达,浓度达10ug/L。结论:成功地在中国仓鼠卵巢细胞中获得了hHGF蛋白的高效、稳定表达。为下一步将表达hHGF的细胞微囊化制备基因工程细胞,并移植用于相关疾病的基因治疗奠定了基础。     

应用抑制性消减杂交技术筛选及鉴定高温致金黄地鼠神经管畸形下调表达基因

目的克隆高温致金黄地鼠神经管畸形下调表达基因，探讨其分子生物学机理。方法应用抑制性消减杂交技术构建高温致畸金黄地鼠胚胎神经管反向消减cDNA文库；联合蓝白斑和菌落PCR方法筛选阳性克隆进行测序和同源性分析；用Northern印迹方法证实这些基因的表达。结果成功构建高温致畸金黄地鼠胚胎神经管反向消减cDNA文库，从中筛选到15个基因，均与GenBank中已知基因有同源性。Northern印迹证实这些基因在高温致畸胚胎神经管中均呈下调表达。结论发现了高温致金黄地鼠神经管畸形过程中的一些重要相关基因并对其功能进行了初步探讨。     

重组人肝细胞生长因子在人脐带间质干细胞中高效表达

目的：构建能表达人肝细胞生长因子(hHGF) 的pWPI-hHGF载体，并将含hHGF基因的重组慢病毒载体转染人脐带间质干细胞（hUCMSCs），观察人脐带间质干细胞中hHGF的表达情况。方法：将携带目的基因hHGF的 pUC-SRα/hHGF质粒亚克隆到真核细胞表达载体pWPI载体上，构建重组质粒pWPI-hHGF。基因测序进行HGF的鉴定。用磷酸钙沉淀法，将pWPI-hHGF、pAX2、pMD2G共同转染包装细胞293T细胞，获得携带目的基因hHGF和GFP基因的重组慢病毒pWPI-hHGF。将pWPI-hHGF及阳性对照质粒pWPI-GFP分别用Lipofectamin 2000介导转染体外培养的hUCMSCs。在荧光显微镜下计数，确定阳性对照质粒的转染数，从而估计该基因的转染效率。蛋白印迹法检测HGF和GFP蛋白的表达，ELISA法检测细胞上清液hHGF含量。结果：DNA 测序显示hHGF基因成功地插入到pWPI载体中。包装细胞293T转导pWPI-HGF质粒后，转染阳性率达100％。阳性对照质粒转染人脐带间质干细胞24 h后，在荧光显微镜下观察，其转染效率达80%以上。蛋白印迹法检测靶细胞中hHGF表达呈强阳性，而对照组表达量极低，两者差异显著(P<0.01)。检测收集转染hHGF后的人间质干细胞上清液中hHGF的表达含量明显高于对照组(P<0.01)。结论：构建的在真核细胞内表达hHGF的重组质粒pWPI-hHGF转染人脐带间质干细胞，能获得hHGF基因在人脐带间质干细胞中大量、稳定的表达。     

肝癌组织差异表达基因cDNA序列的筛选与鉴定

目的：筛选并鉴定肝癌组织特异表达基因。方法：通过菌落原位杂交技术筛选用抑制消减杂交法构建肝癌与癌旁肝组织差异表达基因消减cDNA文库，用PCR方法进一步筛选出有插入片段的阳性克隆，将阳性克隆进行DNA测序和同源性比较分析，用Northern印迹方法对新的cDNA序列进行初步鉴定。结果：从消减文库中随机挑取的100个白色克隆中筛选出13个阳性克隆，DNA测序获得11个不同的cDNA序列；同源性比较分析表明，6个cDNA片段与在基因高度同源，5个cDNA片段为新的序列。其长度大于300bp的3个新序列，Norther印迹证实它都来源于肝癌组织。结论：用抑制消减杂交方法构建的肝癌差异表达基因消减cDNA文库富含肝癌特异表达基因，经验证的3个新的cDNA序列可能为肝癌特异的基因序列。     

抑制性消减杂交技术筛选重组IFNβ下调HepG2细胞靶基因

目的利用抑制性消减杂交（SSH）技术构建重组干扰素β（IFNβ）刺激人肝癌细胞系HepG2差异表达基因的cDNA消减文库，筛选IFNβ下凋HepG2相关基因。方法重组IFNβ2000U／ml刺激对数生长期HepG2细胞，以生理盐水作用的HepG2细胞为阴性对照；制备细胞裂解液，从中提取mRNA并逆转录为cDNA，经Rsa Ⅰ酶切后将实验组cDNA分成两份，分别与两种不同的接头连接，再与对照组cDNA进行两次消减杂交及两次抑制性PCR，将产物与T／A载体连接，构建cDNA消减文库，并转染大肠埃希菌进行文库扩增，随机挑选克隆PCR后进行测序及同源性分析。结果成功构建重组IFNβ刺激HepG2细胞差异表达基因的cDNA消减文库。文库扩增后，得到58个阳性克隆，进行菌落PCR分析，均得到200～1000bp插入片段。随机挑选其中35个插入片段测序，并通过生物信息学分析，结果共获得12种编码基因。结论应用SSH技术成功构建了IFNβ刺激HepG2细胞差异表达基因的cDNA消减文库，为进一步了解IFNβ在肝细胞内的免疫调节机制提供了依据。     

hLMO3基因真核表达载体的构建及蛋白的表达和定位

目的 构建hLMO3真核表达载体并证实融合蛋白在细胞内的表达及定位.方法 以人胎脑文库cDNA为模板,PCR扩增hLMO3基因cDNA全长,亚克隆至pEGFP表达载体中.将构建的重组质粒进行酶切测序鉴定,并转染到人上皮细胞HEK293细胞中,提取细胞蛋白进行Western blot检测.利用激光扫描共聚焦显微镜观察pE...     

人Plk3基因真核表达载体的构建及蛋白表达和定位

目的构建hPlk3真核表达载体并证实融合蛋白在细胞内的表达及定位。方法提取工具细胞Hela的mRNA,反转录为cDNA。PCR扩增hPlk3基因cDNA全长,并将其亚克隆至pEGFP-C1表达载体中。然后将构建的重组质粒进行酶切和测序鉴定,并转染到工具细胞COS-7中,提取细胞蛋白进行Westernblot检测其表达。最后利用激光共聚焦扫描显微镜观察pEGFP-hPlk3在COS-7细胞内的定位。结果hPlk3基因cDNA全长克隆到了真核表达载体pEGFP-C1中,酶切鉴定片段为1941bp,并测序成功。Westernblot检测到了GFP-hPlk3融合蛋白表达,分子量约为98kDa。pEGFP-hPlk3在COS-7细胞中主要定位于细胞质和核周。结论成功构建了hPlk3基因cDNA全长的真核表达载体,pEGFP-hPlk3蛋白在COS-7细胞中主要定位于细胞质和核周。     

丙型肝炎病毒非结构蛋白NS4B肝细胞结合蛋白基因的筛选与克隆

目的筛选并克隆人肝细胞cDNA文库中与丙型肝炎病毒(HCV)非结构蛋白4B(NS4B)相互作用蛋白的基因,明确其具体作用机制。方法应用酵母双杂交系统3,将多聚酶链反应(PCR)法扩增的HCVNS4B基因连接入酵母表达载体pGBKT7中构建诱饵质粒,转化酵母细胞AH109并在其内表达,然后与转化了人肝cDNA文库质粒pACT2的酵母细胞Y187进行配合,在营养缺陷型培养基和Xα半乳糖(Xαgal)上进行双重筛选阳性菌落,提取阳性酵母菌落的质粒转化大肠埃希菌,接种在氨苄西林LB平板上,选择生长菌落,提取质粒酶切鉴定,测序并在GenBank中进行生物信息学分析。结果成功克隆出HCVNS4B基因并在酵母细胞中表达,与肝文库配合后选出既能在4缺(SD/TrpLeuAdeHis)培养基又能在铺有Xαgal的4缺培养基上生长,并变成蓝色的真阳性菌落5个,序列分析显示,筛选到的肝细胞蛋白编码基因参与细胞代谢、生物氧化、生长调节等多种生物学过程。结论成功克隆出HCVNS4B蛋白与肝细胞相互作用蛋白,为进一步研究NS4B蛋白的功能,阐明HCV致病的分子生物学机制提供了新线索。     

人Flt3配体基因的克隆及其在CHO细胞中的表达

目的克隆人Flt3配体（Flt3 LIg and，FL），并在CHO细胞中进行表达。方法从健康人外周血中提取总RNA，通过RT-PCR技术，扩增Flt3配体胞外区cDNA功能性片段，经DNA测序证实后，将得到的片段基因插入pcDNA3．0表达载体，构建了pcDNA3．0-FL真核表达载体；将重组质粒pcDNA3．0-FL转染CHO细胞．经G418筛选出阳性细胞克隆，扩大培养，提取细胞总蛋白，用SDS—PAGE分离并Western blotting检测到在相对分子质量约24000处有一显色条带。结果FL胞外区cDNA被正确克隆到真核表达载体pcDNA3．0中并在CHO细胞中成功表达。结论成功构建了真核表达载体pcDNA3．0-FL并在CHO细胞中成功表达，为FL的相关研究和应用开发奠定了基础。     

Interaction of the human polyomavirus, JCV, with human B-lymphocytes.

The human polyomavirus, JCV, is the causative agent of the central nervous system demyelinating disease progressive multifocal leukoencephalopathy (PML). The principal target of JCV infection in the central nervous system (CNS) is the myelinating oligodendrocyte. However, the site of JCV multiplication outside of the CNS and the mechanism by which virus gains access to the brain are not known. Recently, JCV infected B-lymphocytes have been demonstrated in PML patients in several lymphoid organs, in circulating peripheral lymphocytes, and in brain, suggesting a possible role of B-lymphocytes in the dissemination of virus to the brain. The experiments reported here were undertaken to understand more about the interactions of JCV with human B-lymphocytes. The data show that JCV is able to multiply in either Epstein-Barr virus transformed (EBV) or EBV negative human B cell lines resulting in production of infectious, progeny virions. In addition, nuclear proteins extracted from these B cells bind to similar nucleotides within the JCV regulatory region that are bound by nuclear proteins extracted from human fetal glial cells, the most susceptible host and principal target cell for JCV infection in vitro. It is not known, however, whether these DNA binding proteins from susceptible B cells and glial cells are similar.     

Infection and maturation of monocyte-derived human dendritic cells by human respiratory syncytial virus, human metapneumovirus, and human parainfluenza virus type 3

Human respiratory syncytial virus (HRSV), human metapneumovirus (HMPV), and human parainfluenza virus type 3 (HPIV3) are common, important respiratory pathogens, but HRSV has a substantially greater impact with regard to acute disease, long-term effects on airway function, and frequency of re-infection. It has been reported to strongly interfere with the functioning of dendritic cells (DC). We compared HRSV to HMPV and HPIV3 with regard to their effects on human monocyte-derived immature DC (IDC). Side-by-side analysis distinguished between common effects versus those specific to individual viruses. The use of GFP-expressing viruses yielded clear identification of robustly infected cells and provided the means to distinguish between direct effects of robust viral gene expression versus bystander effects. All three viruses infected inefficiently based on GFP expression, with considerable donor-to donor-variability. The GFP-negative cells exhibited low, abortive levels of viral RNA synthesis. The three viruses induced low-to-moderate levels of DC maturation and cytokine/chemokine responses, increasing slightly in the order HRSV, HMPV, and HPIV3. Infection at the individual cell level was relatively benign, such that in general GFP-positive cells were neither more nor less able to mature compared to GFP-negative bystanders, and cells were responsive to a secondary treatment with lipopolysaccharide, indicating that the ability to mature was not impaired. However, there was a single exception, namely that HPIV3 down-regulated CD38 expression at the RNA level. Maturation by these viruses was anti-apoptotic. Inefficient infection of IDC and sub-optimal maturation might result in reduced immune responses, but these effects would be common to all three viruses rather than specific to HRSV.     

Induction of human leukocyte antigen-A,B,C and -DR on cultured human oligodendrocytes and astrocytes by human gamma-interferon

gamma-Interferon (IFN-gamma) is known to induce expression of major histocompatibility complex (MHC) class II antigens on murine astrocytes and MHC class I antigens on murine oligodendrocytes. We studied whether the human IFN-gamma could induce the expression of Human Leukocyte Antigen (HLA)-A, B, C and -DR antigens on cultured human glia from autopsied brain white matter tissue. HLA-A, B, C antigens were induced on both human astrocytes and oligodendrocytes, whereas HLA-DR antigens were induced only on some astrocytes. From these results, it is suggested that IFN-gamma affects the expression of MHC class I and class II antigens on astrocytes and oligodendrocytes derived from human brain. The relationship between the induction of MHC class I and class II antigens by IFN-gamma and the pathogenesis of multiple sclerosis is discussed.     

Prospective study of human herpesvirus 6, human herpesvirus 7, and cytomegalovirus infections in human immunodeficiency virus-positive patients.

Blood samples from human immunodeficiency virus (HIV)-positive patients were monitored for cytomegalovirus (CMV), human herpesvirus 6 (HHV-6), and HHV-7 by PCR. We detected CMV in 17% of the patients, HHV-6 in 6%, and HHV-7 in 3%. The viral loads of CMV were significantly higher than those of HHV-6 (P = 0.007) or HHV-7 (P = 0.01). Detection of CMV and HHV-6 was associated with low and high CD4 counts, respectively.     

Modeling, control, and simulation of human movement

This article is a discussion and survey of current research activities in modeling, control, and simulation of human movement; the rationale for this methodology, its philosophical implications; current modular implementation; practical and theoretical contributions to other fields such as robotics, prosthetics, medicine, and anatomy; its inherent limitations; relation to other disciplines dealing with human movement; future directions; and the emerging principles that govern human movement.