A cellular protein specifically binds to the 3'-terminal sequences of hepatitis C virus intermediate negative-strand RNA / 中华医学杂志(英文版)

<p><b>OBJECTIVE</b>To study the mechanism of the cellular proteins involved in the process of replication of hepatitis C virus (HCV) negative-strand RNA.</p><p><b>METHODS</b>Ultraviolet (UV) cross-linking was used to identify the cellular proteins that would bind to the 3'-end of HCV negative-strand RNA. Competition experiment was used to confirm the specificity of this binding, in which excess nonhomologous protein and RNA transcripts were used as competitors. The required binding sequence was determined by mapping, then the binding site was predicted through secondary structure analysis.</p><p><b>RESULTS</b>A cellular protein of 45 kD (p45) was found to bind specifically to the 3'-end of HCV negative-strand RNA by UV cross-linking. Nonhomologous proteins and RNA transcripts could not compete out this binding, whereas the unlabeled 3'-end of HCV negative-strand RNA could. Mapping of the protein-binding site suggested that the 3'-end 131-278nt of HCV negative-strand RNA was the possible protein-binding region. Analysis of RNA secondary structure presumed that the potential binding site was located at 194-GAAAGAAC-201.</p><p><b>CONCLUSION</b>The cellular protein p45 could specifically bind to the secondary structure of the 3'-end of HCV intermediate negative-strand RNA, and may play an important role in HCV RNA replication.</p>

Detection of Leptin mRNA Expression Obese Subjects with Digoxigenin Labeled Probe / 中山大学学报(医学科学版)

【Objective】 To study the expression of leptin mRNA in Chinese obese subjects using dot blot hybridization with a digoxigenin labele d probe. 【Methods】 11 Chinese nonobese subjects (bodymass index, BMI 21.0 kg/ m2±1.5 kg/m2) and 12 Chinese obese subjects(BMI 28.5 kg/m2±2.3 kg/m 2) parti cipated in the study. The human leptin cDNA probe was labeled wih digoxigenin(DI G) b y the random priming method. Expression of leptin mRNA in abdominal adipose tiss ue has been examined using dot blot hybridization with this probe. 【Results】 T he expression of leptin mRNA was significantly higher in obese subjects than in non-obese ones (312.8±108.9 vs 175.9±81.5, relative units, P<0.0 5), an d correlated with BMI (r=0.56, P<0.05). 【Conclusions】 Leptin mRNA le vel is high in obese subjects, and correlated with BMI.

Study of CD40 and CD80 on peripheral blood dendritic cells in patients with chronic hepatitis B in vitro / 中国免疫学杂志

Objective:To study the relation between the costimulating molecules CD40,CD80 on DC and their antigen presentation function in patients with chrnic HBV infection .Methods:The DC from healthy donors and patients were stained with anti human specific mouse monoclonal antibodies conjugated with fluorescein isothiocyanate(FITC) respectively.Mouse McAb used were anti HLA ABC,HLA DR,CD1a,CD14,CD40,CD80.Results:There are no remarkable difference in MHC I?MHC II between two groups;remarkable difference was showed in CD40(P

Signal peptide sequence of human interleukin-2 influenced hEndostatin gene expression and protein secretion in HepG2 cells / 中国病理生理杂志

AIM: The role of human interleukin-2(IL-2) signal peptide sequence in the effect of human Endostatin (hEndostatin) expression and secretion was investigated in HeG2 cells. METHODS: RT-PCR and Western-blotting were conduct to observe mRNA level difference of hEndostatin gene, its protein expression and secretion level difference between with hIL-2 signal peptide sequence and without it. RESULTS: mRNA level of hEndostatin gene in HepG2 (pBlast-hIL2-hEndo) cells was higher than that in HepG2(pBlast-hEndo)( P