AIM: To study the transcriptional regulation of human telomerase reverse transcriptase (hTERT) mRNA in normal human cholangiocytes (HBECs) after hepatitis B virus X (HBx) gene transfection and to elucidate the possibl...AIM: To study the transcriptional regulation of human telomerase reverse transcriptase (hTERT) mRNA in normal human cholangiocytes (HBECs) after hepatitis B virus X (HBx) gene transfection and to elucidate the possible mechanism of HBV infection underlying cholangiocarcinoma.METHODS: HBECs were cultured in vitroand co-transfected with a eukaryotic expression vector containing the HBx coding region and a doning vector containing coding sequences of enhanced green fluorescent protein (EGFP) using lipidmediated gene transfer. The transfection efficiency was determined by the expression of EGFP. The expressions of hTERT mRNA and HBx protein in HBECs were detected by RT-PCR and immunocytochemical stain, respectively.RESULTS: The transfection efficiencies were about 15% for both HBx gene expression plasmid and empty vector.No hTERT mRNA was expressed in HBECs when transfected with OPTI-NEN medium and empty vector, but a dramatic increase was observed for hTERT mRNA expression in HBECs when transfected with HBx expression vector. HBx proyein was only expressed in HBECs when transfected with HBx expression vector.CONCLUSION: HBx transfection can activate thet ranscriptional expression of hTERT mRNA. Cis-activation of hTERT mRNA by HBx gene is the primary mechanism underlying the proliferation, differentiation and tumorigenesis of biliary epithelia.展开更多
The application of paclitaxel(PTX) in clinic has been restricted due to its poor solubility.Several traditional nano-medicines have been developed to improve this defect,while they are still lack of tumor targeting ab...The application of paclitaxel(PTX) in clinic has been restricted due to its poor solubility.Several traditional nano-medicines have been developed to improve this defect,while they are still lack of tumor targeting ability and rapid drug release. In this work,an amphiphilic polymeric micelle of hyaluronic acid(HA) – all-trans-retinoid acid(ATRA) with a disulfide bond,was developed successfully for the co-delivery of PTX and ATRA. The combination chemotherapy of PTX and ATRA can strengthen the anti-tumor activity. Along with selfassembling to micelles in water,the delivery system displayed satisfying drug loading capacities for both PTX(32.62% ± 1.39%) and ATRA,due to directly using ATRA as the hydrophobic group. Rapid drug release properties of the PTX-loaded redox-sensitive micelles(HA-SS-ATRA) in vitro were confirmed under reducing condition containing GSH. Besides,HA-CD44 mediated endocytosis promoted the uptake of HA-SS-ATRA micelles by B16 F10 cells. Due to these properties,cytotoxicity assay verified that PTX-loaded HA-SS-ATRA micelles showed concentration-dependent cytotoxicity and displayed obvious combination therapy of PTX and ATRA. Importantly,HA-SS-ATRA micelles could remarkably prolong plasma circulation time after intravenously administration. Therefore,redox-sensitive HASS-ATRA micelles could be utilized and explored as a promising drug delivery system for cancer combination chemotherapy.展开更多
The second-order optical nonlinearity of CdS nanoparticles with different diameters of 28.0, 30.0, 31.5, 50.0, and 91.0 A was studied by hyper-Rayleigh scattering technique. Results show that the first-order hyperpola...The second-order optical nonlinearity of CdS nanoparticles with different diameters of 28.0, 30.0, 31.5, 50.0, and 91.0 A was studied by hyper-Rayleigh scattering technique. Results show that the first-order hyperpolarizability P value per CdS partiele decreases as size is reduced to diameter of 31.5 A; however, as CdS size further decreases, this trend is reversed and (J value increases. Substantially, the normalized P value per CdS formula unit, β0, exhibits systematic enhancement with decreasing size. This phenomenon is interpreted in terms of a so-called surfaee contribution mechanism.展开更多
The paper analyzes the interaction between the pension system and capital marketdevelopment, especially the case of China. A funded pension system is most likely to boostthe capital market, but in the absence of a sup...The paper analyzes the interaction between the pension system and capital marketdevelopment, especially the case of China. A funded pension system is most likely to boostthe capital market, but in the absence of a supportive financial infrastructure and effectivefinancial regulation, a funded system will not be successful. Chinas determination to establisha partially funded system is a first step in the right direction, but without the separation ofindividual accounts from the social pooling and their replenishment, the working out of theimplicit pension debt, and improvements in pension fund management and regulation, thepension system will not be sustainable. The key to capital market development in the processof the pension reform is to enact laws to protect the interests of pensioners, to contract outpension fund management to professional asset managers, and to accelerate the financialopening.展开更多
基金Supported by the National High Technology Research and Development Program of China,863 Program,No.2002AA214061
文摘AIM: To study the transcriptional regulation of human telomerase reverse transcriptase (hTERT) mRNA in normal human cholangiocytes (HBECs) after hepatitis B virus X (HBx) gene transfection and to elucidate the possible mechanism of HBV infection underlying cholangiocarcinoma.METHODS: HBECs were cultured in vitroand co-transfected with a eukaryotic expression vector containing the HBx coding region and a doning vector containing coding sequences of enhanced green fluorescent protein (EGFP) using lipidmediated gene transfer. The transfection efficiency was determined by the expression of EGFP. The expressions of hTERT mRNA and HBx protein in HBECs were detected by RT-PCR and immunocytochemical stain, respectively.RESULTS: The transfection efficiencies were about 15% for both HBx gene expression plasmid and empty vector.No hTERT mRNA was expressed in HBECs when transfected with OPTI-NEN medium and empty vector, but a dramatic increase was observed for hTERT mRNA expression in HBECs when transfected with HBx expression vector. HBx proyein was only expressed in HBECs when transfected with HBx expression vector.CONCLUSION: HBx transfection can activate thet ranscriptional expression of hTERT mRNA. Cis-activation of hTERT mRNA by HBx gene is the primary mechanism underlying the proliferation, differentiation and tumorigenesis of biliary epithelia.
基金financially supported by the National Natural Science Foundation of China (Grant Nos. 81703382 and 81673567)
文摘The application of paclitaxel(PTX) in clinic has been restricted due to its poor solubility.Several traditional nano-medicines have been developed to improve this defect,while they are still lack of tumor targeting ability and rapid drug release. In this work,an amphiphilic polymeric micelle of hyaluronic acid(HA) – all-trans-retinoid acid(ATRA) with a disulfide bond,was developed successfully for the co-delivery of PTX and ATRA. The combination chemotherapy of PTX and ATRA can strengthen the anti-tumor activity. Along with selfassembling to micelles in water,the delivery system displayed satisfying drug loading capacities for both PTX(32.62% ± 1.39%) and ATRA,due to directly using ATRA as the hydrophobic group. Rapid drug release properties of the PTX-loaded redox-sensitive micelles(HA-SS-ATRA) in vitro were confirmed under reducing condition containing GSH. Besides,HA-CD44 mediated endocytosis promoted the uptake of HA-SS-ATRA micelles by B16 F10 cells. Due to these properties,cytotoxicity assay verified that PTX-loaded HA-SS-ATRA micelles showed concentration-dependent cytotoxicity and displayed obvious combination therapy of PTX and ATRA. Importantly,HA-SS-ATRA micelles could remarkably prolong plasma circulation time after intravenously administration. Therefore,redox-sensitive HASS-ATRA micelles could be utilized and explored as a promising drug delivery system for cancer combination chemotherapy.
基金supposed by the National Natural Science Foundation of China(Nos.50202009,10074023)the National Postdoctoral Foundation(No.2002031222).
文摘The second-order optical nonlinearity of CdS nanoparticles with different diameters of 28.0, 30.0, 31.5, 50.0, and 91.0 A was studied by hyper-Rayleigh scattering technique. Results show that the first-order hyperpolarizability P value per CdS partiele decreases as size is reduced to diameter of 31.5 A; however, as CdS size further decreases, this trend is reversed and (J value increases. Substantially, the normalized P value per CdS formula unit, β0, exhibits systematic enhancement with decreasing size. This phenomenon is interpreted in terms of a so-called surfaee contribution mechanism.
文摘The paper analyzes the interaction between the pension system and capital marketdevelopment, especially the case of China. A funded pension system is most likely to boostthe capital market, but in the absence of a supportive financial infrastructure and effectivefinancial regulation, a funded system will not be successful. Chinas determination to establisha partially funded system is a first step in the right direction, but without the separation ofindividual accounts from the social pooling and their replenishment, the working out of theimplicit pension debt, and improvements in pension fund management and regulation, thepension system will not be sustainable. The key to capital market development in the processof the pension reform is to enact laws to protect the interests of pensioners, to contract outpension fund management to professional asset managers, and to accelerate the financialopening.
