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Objective To evaluate the effect of silencing leptin by small interfering RNA(siRNA)on the expression of lep‐tin ,and apoptosis ,proliferation and intracellular Ca2+ concentration([Ca2+ ]i )of hepatic stellate cells(HSCs)and to provide evi‐dence for liver fibrosis gene therapy.Methods HSCs were divided into normal control group ,blank vector group ,siRNA nega‐tive control group and leptin‐siRNA group.After transfection of the leptin‐siRNAs into HSCs ,cell proliferation was measured by MTT assay.Cell cycle and apoptosis were measured by flow cytometry.Expression of leptin was detected by immunocyto‐chemistry and Western blot. [Ca2+ ]i was measured by Fura‐2/AM loading.Results Compared with the normal control group , the blank vector group and the siRNA control group ,the protein expression of leptin and the cell growth were significantly in‐hibited in the leptin‐siRNA group(P<0.05). The proliferation rate of HSCs was significantly different at different time points (24 ,48 and 72 h)(P<0.05).The cell apoptosis rate was increased significantly in the leptin‐siRNA group(P<0.01).At the same time ,Leptin‐siRNA‐induced [Ca2+ ]i was also significantly reduced(P<0.05).Conclusion The leptin gene may play an important role in liver fibrosis progression and is potentially a novel predictive and prognostic marker for liver fibrosis.
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To construct the specific siRNA expression vectors and investigate their effect on leptin and collagen I in HSC, which provide a new approach to the prevent and treat hepatic fibrosis. The five siRNAs against leptin gene were transcript synthesized intracellularly by expression templates of plasmid vector psiRNA-hH1neo. The recombinant leptin siRNA plasmid vectors could express in eukaryocyte , and then to evaluate them by using enzyme cutting and sequencing. The recombinant plasmids were transfected into HSCs using Lipofectamine methods respectively. The cells were selected after growing in DMEM containing 300 μg/mL G418 for about 4 weeks. Gene expression of leptin and collagen I were showed by Western blot analysis and reverse transcription polymerase chain reaction (RT-PCR). Identification by enzyme cutting and sequencing showed that the leptin siRNA expression vectors were constructed successfully, and leptin siRNA could inhibit the leptin and collagen I gene expression effectively. It was concluded that RNA interference-mediated silencing of leptin gene diminished leptin and collagen I gene expression in HSCs. Furthermore, attenuated the extracellular matrix over-deposition at the same time. Leptin gene is ideal targets of gene therapy for liver fibrosis.
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To investigate the killing effect of PNP/MeP-dR suicide gene system on hepatoma cells,pcDNA3. 0/PNP, an eukaryotic expression vector harboring E. coli PNP gene, was transfected into human hepatoma HepG2 cells by liposome-mediated method. A HepG2 cell line with stable PNP gene expression, HepG2/PNP, was established with presence of G418 selection. The cell growth curves were determined with trypan blue staining. The sensitivity of HepG2/PNP to MePdR and bystander effects were assayed by MTT and FCM methods. The enzymatic activity of the product of PNP gene was determined by HPLC method. The cytotoxic effects of MeP-dR on HepG2/PNP cells were obvious (IC50 =4.5μmol/L) and all HepG2/PNP cells were killed 4 days after the treatment with 100μmol/L MeP～dR. In mixed cultures containing increasing percentages of HepG2/PNP cells, total population killing was demonstrated when HepG2/PNP cells accounted for as few as 5% of all HepG2 cells 8 days after the treatment with 100μmol MeP-dR. Highpressure liquid chromatography (HPLC) demonstrated that the PNP enzyme could convert MePdR into 6-MP. PNP/MeP-dR suicide gene system had an advantage over traditional suicide gene systems for hepatoma gene therapy. Our e results suggest that high-level bystander effects of this system result in significant anti-tumor responses to hepatoma gene therapy, especially in vivo.
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Objectives:To discuss the characteristics of nursing care of patients with cardiomegaly after heart valve replacement operation. Methods:From October 1997 to January 2000, 65 patients with cardiomegaly received heart valve replacement operations. According to the degree of cardiomegaly, these patients were divided into 3 types: left atrium, left ventricle and whole heart cardiomegaly. Different nursings were applied depending on the features of each type. Results:Complications occurred in 28 patients(12 in left atrium,11 in left ventricle and 5 in whole heart cardiomegaly),all of whom were cured;2 patients died, the mortality rate was 3.08%. Conclusions: To lower the morbidity and mortality, different kinds of nursing care should be applied to different cardiomegaly after heart valve replacement operations.
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AIM: To study the effects of hypothermia on the contents of AVP,Ang Ⅱ,L-EK,cAMP,Mg 2+ and Ca 2+ in rat plasma and different brain regions.METHODS: The model of experimental hypothermia rat was established and treated in groups randomly.At the end of the experiment,samples of plasma and braintissues were taken and the contents of L-EK,cAMP,AVP,Ang Ⅱ were determined by RIA methods,Mg 2+ and Ca 2+ by atom absorption methods.RESULTS: The contents of Ang Ⅱ,AVP increased significantly in the plasma of Ⅰ,Ⅲ group( P