AIM： Hydrodynamics based transfection （HBT）, the injection of a large volume of naked plasmid DNA in a short time is a relatively simple, efficient and safe method for in vivo transfection of liver cells. Though us...AIM： Hydrodynamics based transfection （HBT）, the injection of a large volume of naked plasmid DNA in a short time is a relatively simple, efficient and safe method for in vivo transfection of liver cells. Though used for quite some time, the mechanism of gene transfection has not yet been elucidated. METHODS： A lucJferase encoding plasmid was injected using the hydrodynamics based procedure into normal and thioacetamide-induced fibrotic Sprague Dawley rats. Scanning and transmission electron microscopy images were taken. The consequence of a dual injection of Ringer solution and luciferase pDNA was followed. Halofuginone, an anti collagen type I inhibitor was used to reduce ECM load in fibrotic rats prior to the hydrodynamic injection. RESULTS： Large endothelial gaps formed as soon as 10＇ following hydrodynamic injection; these gradually returned to normal 10 d post injection. Hydrodynamic administration of Ringer 10 or 30 m prior to moderate injection of plasmid did not result in efficient transfection suggesting that endothelial gaps by themselves are not sufficient for gene expression. Gene transfection following hydrodynamic injection in thioacetamide induced fibrotic rats was diminished coinciding with the level of fibrosis. Halofuginone, a specific collagen type I inhibitor, alleviated this effect. CONCLUSION： The hydrodynamic pressure formed following HBT results in the formation of large endothelial gaps. These gaps, though important in the transfer of DNA molecules from the blood to the space of Disse are not enough to provide the appropriate conditions for hepatocyte transfection. Hydrodynamics based injection is applicable in fibrotic rats provided that ECM load is reduced.展开更多
Endoscopic submucosal dissection(ESD)and endoscopic mucosal resection(EMR)are useful therapeutic techniques for colorectal tumors.Currently,new techniques based on these procedures are available,such as endoscopic sub...Endoscopic submucosal dissection(ESD)and endoscopic mucosal resection(EMR)are useful therapeutic techniques for colorectal tumors.Currently,new techniques based on these procedures are available,such as endoscopic submucosal dissection with snare(ESD-S)and endoscopic mucosal resection with pre-cutting(EMR-P).For the excision of colorectal tumors,each of these techniques has been characterized as having a high total resection rate,low recurrence rate or low complication rate.In this study,we analysed clinical trials that had recently been published,to search for the most appropriate endoscopic treatment for colorectal tumors.Our search results revealed the following:for a tumor with a diameter less than 20mm,the surgeon should choose ESD,ESD-S,EMR-P or EMR,depending on the condition of the tumor.On the other hand,to excise a tumor larger than 20mm in diameter,ESD and ESD-S should be the first choices.However,if the patient has a high risk of complications due to ESD or ESD-S,the use of EMR-P would be suitable.Because of the high possibility of canceration in a tumor larger than 20mm in diameter,EMR is not the optimal endoscopic treatment for the excision of a colorectal tumor,due to a low total resection rate and a high recurrence rate.展开更多
Avermectin,a new antibiotic biologicalpesticide,is poisonous on contact,poisonousif ingested and has strong penetrating power.But it has extensive applications.It can be usedas insecticide for agriculture,anthelmintic...Avermectin,a new antibiotic biologicalpesticide,is poisonous on contact,poisonousif ingested and has strong penetrating power.But it has extensive applications.It can be usedas insecticide for agriculture,anthelmintic foranimals,chemical for household sanitation andalso as a filaria repellent for human bodies.展开更多
基金Supported by the Israel Science Foundation, No. 537/01, the C. Rosenblantt Cancer Research Fund and the Rappaport Institute Fund
文摘AIM： Hydrodynamics based transfection （HBT）, the injection of a large volume of naked plasmid DNA in a short time is a relatively simple, efficient and safe method for in vivo transfection of liver cells. Though used for quite some time, the mechanism of gene transfection has not yet been elucidated. METHODS： A lucJferase encoding plasmid was injected using the hydrodynamics based procedure into normal and thioacetamide-induced fibrotic Sprague Dawley rats. Scanning and transmission electron microscopy images were taken. The consequence of a dual injection of Ringer solution and luciferase pDNA was followed. Halofuginone, an anti collagen type I inhibitor was used to reduce ECM load in fibrotic rats prior to the hydrodynamic injection. RESULTS： Large endothelial gaps formed as soon as 10＇ following hydrodynamic injection; these gradually returned to normal 10 d post injection. Hydrodynamic administration of Ringer 10 or 30 m prior to moderate injection of plasmid did not result in efficient transfection suggesting that endothelial gaps by themselves are not sufficient for gene expression. Gene transfection following hydrodynamic injection in thioacetamide induced fibrotic rats was diminished coinciding with the level of fibrosis. Halofuginone, a specific collagen type I inhibitor, alleviated this effect. CONCLUSION： The hydrodynamic pressure formed following HBT results in the formation of large endothelial gaps. These gaps, though important in the transfer of DNA molecules from the blood to the space of Disse are not enough to provide the appropriate conditions for hepatocyte transfection. Hydrodynamics based injection is applicable in fibrotic rats provided that ECM load is reduced.
基金The National Natural Science Foundation of China(Grant No.81101566).
文摘Endoscopic submucosal dissection(ESD)and endoscopic mucosal resection(EMR)are useful therapeutic techniques for colorectal tumors.Currently,new techniques based on these procedures are available,such as endoscopic submucosal dissection with snare(ESD-S)and endoscopic mucosal resection with pre-cutting(EMR-P).For the excision of colorectal tumors,each of these techniques has been characterized as having a high total resection rate,low recurrence rate or low complication rate.In this study,we analysed clinical trials that had recently been published,to search for the most appropriate endoscopic treatment for colorectal tumors.Our search results revealed the following:for a tumor with a diameter less than 20mm,the surgeon should choose ESD,ESD-S,EMR-P or EMR,depending on the condition of the tumor.On the other hand,to excise a tumor larger than 20mm in diameter,ESD and ESD-S should be the first choices.However,if the patient has a high risk of complications due to ESD or ESD-S,the use of EMR-P would be suitable.Because of the high possibility of canceration in a tumor larger than 20mm in diameter,EMR is not the optimal endoscopic treatment for the excision of a colorectal tumor,due to a low total resection rate and a high recurrence rate.
文摘Avermectin,a new antibiotic biologicalpesticide,is poisonous on contact,poisonousif ingested and has strong penetrating power.But it has extensive applications.It can be usedas insecticide for agriculture,anthelmintic foranimals,chemical for household sanitation andalso as a filaria repellent for human bodies.
