2006年5月以来,我国部分猪场暴发了一种以高热、高发病率和高死亡率为特征的传染性疾病,经病原分离及分子流行病学分析证明是由一种带有nsp2部分缺失的、对猪呈高致病性的猪繁殖与呼吸综合征病毒(Porcine reproductive and respiratory ...2006年5月以来,我国部分猪场暴发了一种以高热、高发病率和高死亡率为特征的传染性疾病,经病原分离及分子流行病学分析证明是由一种带有nsp2部分缺失的、对猪呈高致病性的猪繁殖与呼吸综合征病毒(Porcine reproductive and respiratory syndrome virus,PRRSV)引起的。本实验参考GenBank发表的以及本实验室分离鉴定的PRRSV的nsp2基因序列,在nsp2缺失区的两端的保守区设计并合成了一对引物,建立了一种PRRSV的RT-PCR检测方法。该方法扩增高致病性PRRSV基因组时可获得230bp的片段,扩增经典型PRRSV时则获得320bp的片段,根据RT-PCR产物大小可将二者区分开来。通过大量临床病料的检测,并配合PCR产物测序验证,结果表明该方法简便、快速、特异,可以鉴别高致病性PRRSV,为进一步的PRRS流行病学研究提供了重要的技术手段。展开更多
AIM：To analyze the genetic and epigenetic alterations of RUNX3 gene, a potential putative tumor suppressor gene,in hepatocellular carcinoma (HCC).METHODS: PCR-based loss of heterozygosity (LOH) detection, analysis of...AIM：To analyze the genetic and epigenetic alterations of RUNX3 gene, a potential putative tumor suppressor gene,in hepatocellular carcinoma (HCC).METHODS: PCR-based loss of heterozygosity (LOH) detection, analysis of mutation with PCR-single strand conformational polymorphism (SSCP) and sequencing, and methylation study with methylation specific PCR (MSP) were performed on RUNX3 gene in a series of 62 HCCs along with their matched normal tissues.RESULTS:Mutation of RUNX3 gene was not found, but one single nucleotide polymorphism with T to A transversion at the second nucleotide of the 18th condon was found.Nine of 26 informative cases (34.6%) showed allelic loss on the polymorphic site and 30 cases (48.4%) revealed hypermethylation of RUNX3 gene in promoter CpG islands.Furthermore,of the 9 cases with LOH, 8 (88.9%) also had hypermethylation.CONCLUSION:Our findings indicate that inactivation of RUNX3 gene through allelic loss and promoter hypermethylation might be one of the major mechanisms in hepatocellualr carcinogenesis.展开更多
AIM: To identify the differentially secreted proteins or polypeptides associated with tumorigenesis of esophageal squamous cell carcinoma (ESCC) from serum and to find potential tumor secreted biomarkers.METHODS: Prot...AIM: To identify the differentially secreted proteins or polypeptides associated with tumorigenesis of esophageal squamous cell carcinoma (ESCC) from serum and to find potential tumor secreted biomarkers.METHODS: Proteins from human ESCC tissue and its matched adjacent normal tissue; pre-surgery and postsurgery serum; and pre-surgery and normal control serum were separated by two-dimensional electrophoresis (2-DE)to identify differentially expressed proteins. The silverstained 2-DE were scanned with digital ImageScanner and analyzed with ImageMaster 2D Elite 3.10 software. A cluster of protein spots differentially expressed were selected and identified with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). One of the differentially expressed proteins, clusterin, was downregulated in cancer tissue and pre-surgery serum, but it was reversed in post-surgery serum. The results were confirmed by semi-quantitative reverse-transcription (RT)-PCR and western blot.RESULTS: Comparisons of the protein spots identified on the 2-DE maps from human matched sera showed that some proteins were differentially expressed, with most of them showing no differences in composition, shape or density.Being analyzed by MALDI-TOF-MS and database searching,clusterin was differentially expressed and down-regulated in both cancer tissue and pre-surgery serum compared with their counterparts. The results were also validated by RTPCR and western blot.CONCLUSION: The differentially expressed clusterin may play a key role during tumorigenesis of ESCC. The 2DE-MS based proteomic approach is one of the powerful tools for discovery of secreted markers from peripheral.展开更多
AIM: To construct a vacA-knockout Helicobacter pylori mutant strain, whose only difference from the wild strain is its disrupted vacA gene.METHODS AND RESULTS: A clone containing kanamycin resistance gene used for hom...AIM: To construct a vacA-knockout Helicobacter pylori mutant strain, whose only difference from the wild strain is its disrupted vacA gene.METHODS AND RESULTS: A clone containing kanamycin resistance gene used for homologous recombination was constructed in a directional cloning procedure into pBluescript ⅡSK, and then transformed into vacA+ H pylori by electroporation.Colonies growing on the selective media containing kanamycin were harvested for chromosomal DNA extraction,and the allelic exchange was determined by polymerase chain reactions and sequencing. Loss of vacuolating activity of the vaci-knockout strain was confirmed by examining the gastric cells co-cultured with cell-free supernatants from H pylori wild strain or the mutant.CONCLUSION: We constructed a vacA-knockout strain of H pylori through direct mutagenesis, which creates an important precondition for the future research on virulence comparison with gene expression analysis.展开更多
文摘AIM：To analyze the genetic and epigenetic alterations of RUNX3 gene, a potential putative tumor suppressor gene,in hepatocellular carcinoma (HCC).METHODS: PCR-based loss of heterozygosity (LOH) detection, analysis of mutation with PCR-single strand conformational polymorphism (SSCP) and sequencing, and methylation study with methylation specific PCR (MSP) were performed on RUNX3 gene in a series of 62 HCCs along with their matched normal tissues.RESULTS:Mutation of RUNX3 gene was not found, but one single nucleotide polymorphism with T to A transversion at the second nucleotide of the 18th condon was found.Nine of 26 informative cases (34.6%) showed allelic loss on the polymorphic site and 30 cases (48.4%) revealed hypermethylation of RUNX3 gene in promoter CpG islands.Furthermore,of the 9 cases with LOH, 8 (88.9%) also had hypermethylation.CONCLUSION:Our findings indicate that inactivation of RUNX3 gene through allelic loss and promoter hypermethylation might be one of the major mechanisms in hepatocellualr carcinogenesis.
基金the Major State Basic Research Development Program of China,No.G19980512 and No.2001CB510201the National Hi-Tech R & D Program of China,No.2001AA227091 and No.2001 AA233061National Natural Science Foundation of China,No.39990570,No.30171049,30225045 and No.39990600
文摘AIM: To identify the differentially secreted proteins or polypeptides associated with tumorigenesis of esophageal squamous cell carcinoma (ESCC) from serum and to find potential tumor secreted biomarkers.METHODS: Proteins from human ESCC tissue and its matched adjacent normal tissue; pre-surgery and postsurgery serum; and pre-surgery and normal control serum were separated by two-dimensional electrophoresis (2-DE)to identify differentially expressed proteins. The silverstained 2-DE were scanned with digital ImageScanner and analyzed with ImageMaster 2D Elite 3.10 software. A cluster of protein spots differentially expressed were selected and identified with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). One of the differentially expressed proteins, clusterin, was downregulated in cancer tissue and pre-surgery serum, but it was reversed in post-surgery serum. The results were confirmed by semi-quantitative reverse-transcription (RT)-PCR and western blot.RESULTS: Comparisons of the protein spots identified on the 2-DE maps from human matched sera showed that some proteins were differentially expressed, with most of them showing no differences in composition, shape or density.Being analyzed by MALDI-TOF-MS and database searching,clusterin was differentially expressed and down-regulated in both cancer tissue and pre-surgery serum compared with their counterparts. The results were also validated by RTPCR and western blot.CONCLUSION: The differentially expressed clusterin may play a key role during tumorigenesis of ESCC. The 2DE-MS based proteomic approach is one of the powerful tools for discovery of secreted markers from peripheral.
基金Ministry of Education Research Foundation for Returned Overseas Chinese Scholars Abroad(2001)498
文摘AIM: To construct a vacA-knockout Helicobacter pylori mutant strain, whose only difference from the wild strain is its disrupted vacA gene.METHODS AND RESULTS: A clone containing kanamycin resistance gene used for homologous recombination was constructed in a directional cloning procedure into pBluescript ⅡSK, and then transformed into vacA+ H pylori by electroporation.Colonies growing on the selective media containing kanamycin were harvested for chromosomal DNA extraction,and the allelic exchange was determined by polymerase chain reactions and sequencing. Loss of vacuolating activity of the vaci-knockout strain was confirmed by examining the gastric cells co-cultured with cell-free supernatants from H pylori wild strain or the mutant.CONCLUSION: We constructed a vacA-knockout strain of H pylori through direct mutagenesis, which creates an important precondition for the future research on virulence comparison with gene expression analysis.
