Application of polytetrafluoroethylene as VEGF gene carrier / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To investigate the feasibility of vascular graft material polytetrafluoroethylene (PTFE) as gene carrier of vascular endothelial growth factor (VEGF).</p><p><b>METHODS</b>The PTFE strips were soaked in pCDI-hVEGF(121) solution,marked with EB solution, and then observed under ultraviolet light. The PTFE strips carrying pCDI-hVEGF(121) were soaked in normal saline and the value of optical density at 260 nm on different time was measured, then the controlled release curve was made. The PTFE strips carrying pCDI-hVEGF(121) were implanted into the left thigh muscles of rabbits and the PTFE strips without VEGF gene were implanted into the right. The expression of VEGF(121) mRNA versus beta-actin mRNA in muscles around vascular graft materials was evaluated by reverse transcriptase polymerase chain reaction(RT-PCR). The expression of VEGF(121) protein in muscle was determined by Western blot method.</p><p><b>RESULT</b>The fluorescence on PTFE strips carrying pCDI-hVEGF(121) was observed under ultraviolet light. The controlled release curve demonstrated that the gene release was fast during 0.5 -4 h, then slowed down afterwards,and lasted for 72 h. RT-PCR and Western blot showed VEGF(121)/beta-actin mRNA ratios were 1.053+/-0.356,1. 718+/-0.404, 2.021+/-0.303, 1.872+/-0.231, 0.986+/-0.254, 0.340+/-0.116 and VEGF(121)protein expression levels were 0.328+/-0.088, 1.019+/-0.105, 2.249 +/-0.203, 2.036+/-0.079, 1.670+/-0.132, 0.636+/-0.107 at 1, 7, 14, 28, 42, and 56 days after implantation, respectively.</p><p><b>CONCLUSION</b>The PTFE graft can be used as carrier of VEGF gene and VEGF gene can be transferred to skeletal muscle by this method.</p>

Proliferation of endothelial cell on polytetrafluoroethylene vascular graft materials carried VEGF gene plasmid / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

<p><b>OBJECTIVE</b>To investigate whether vascular endothelial growth factor (VEGF) gene plasmid carried by polytetrafluoroethylene (PTFE) vascular graft materials could transfect endothelial cells (ECs) and promote their growth.</p><p><b>METHODS</b>PTFE vascular graft materials carried with pCDI-hVEGF(121), pCDI or pEGFP were incubated in Tris-buffer solution and the values of optical density of 260 nm at different time were plotted, then the DNA controlled release curve was made. ECs derived from human umbilical vein were seeded on the pCDI-hVEGF(121)/pCDI/pEGFP-PTFE materials or tissue culture plates, ECs numbers were counted and VEGF protein concentrations at different time were measured by enzyme-linked immunoadsorbent assay method. Green fluorescent protein (GFP) expression in ECs on pEGFP-PTFE materials was examined with fluorescence microscopy.</p><p><b>RESULTS</b>The controlled release curve showed that the gene released from PTFE materials was rapid within 8 h, then slowed down and that the gene released continuously even after 72 h. At 24, 72 and 120 h, ECs number and proliferation rate of pCDI-hVEGF(121)-PTFE materials were higher than those of pCDI or pEGFP-PTFE materials (P<0.05). VEGF protein concentration of pCDI-hVEGF(121)-PTFE materials was higher than that of pCDI or pEGFP-PTFE materials at 6, 24, 72 and 120 h (P<0.01). GFP expression in ECs on the pEGFP-PTFE materials could be detected by fluorescence microscopy.</p><p><b>CONCLUSION</b>PTFE graft can be used as a carrier of VEGF gene plasmid, VEGF gene carried by PTFE can transfect ECs and promote ECs growth.</p>

Patients' quality of life after laparoscopic or open cholecystectomy / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

<p><b>OBJECTIVE</b>This study was aimed at evaluating and comparing the quality of life in patients who underwent laparoscopic and open cholecystectomy for chronic cholecystolithiasis.</p><p><b>METHODS</b>The study included 25 patients with laparoscopic cholecystectomy (LC group) and 26 with open cholecystectomy (OC group). The quality of life was measured with the Gastrointestinal Quality of Life Index (GLQI) preoperatively, thereafter regularly at 2, 5, 10 and 16 weeks after the operation.</p><p><b>RESULTS</b>The mean preoperative overall GLQI scores were 112.5 and 110.3 in LC and OC group respectively (P>0.05). In the LC group, the mean overall GLQI score reduced slightly to 110.0 two weeks after the operation (P>0.05). The LC group showed significant improvement in overall score and in the aspects of symptomatology, emotional and physiological status from 5 to 16 weeks postoperatively. In the OC group, the GLQI score reduced to 102.0 two weeks after surgery (P<0.05). Significant reductions were shown in the aspects of symptomatology, physiological and social status. The GLQI scores returned to the preoperative level of 115.6 ten weeks after the operation (P>0.05). The patients experienced significant improvements of GLQI sixteen weeks after OC operation (P<0.01~0.05). Within the 10 postoperative weeks, the LC group had significantly higher GLQI scores than the OC group (P<0.05).</p><p><b>CONCLUSIONS</b>LC can improve the quality of life postoperatively better and more rapidly than OC. The assessment of quality of life assessment is a valid method for measuring the effects of surgical treatment.</p>

Surgical management of gastric stump cancer: a report of 37 cases / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

<p><b>OBJECTIVE</b>To observe the clinicopathological characteristics of gastric stump cancer (GSC) and evaluate the benefits of radical surgery of GSC.</p><p><b>METHODS</b>The clinicopathological characteristics and postoperative survival time of 37 GSC patients who underwent surgery were investigated retrospectively. The survival time was compared according to the type of surgical operation (radical resection vs palliative operation). Twenty-one cases that received radical resection were analyzed based on the pTMN stage. Survival curves were traced by using Kaplan-Meier methods.</p><p><b>RESULTS</b>Most GSC (32/37) was detected in patients who had received Billroth II reconstruction after partial gastrectomy for benign gastric disease. The lesser curvature side and the suture line of anastomosis were the most frequent sites where GSC occurred (27/37). Differentiated adenocarcinoma was the dominant histopathological type (24/37). The postoperative 5-year survival rate of early stage GSC patients (n=9) was significantly higher than advanced stage GSC (n=12) (55.6% vs 16.5%, xL2=11.48, P<0.01). Five-year survival rate of 21 GSC patients with radical resection were 75% (3/4) for stage I, 60% (3/5) for stage II, 14.2% (1/7) for stage III, and 0% (0/5) for stage IV respectively. The median survival time of 21 GSC patients who underwent radical resection was longer than those undergoing palliative operation (43.0 m vs 13.0 m, x L2=36.31, P<0.01), the median survival time of stage IV patients with radical resection was 23.8 months.</p><p><b>CONCLUSIONS</b>Without remote metastasis, radical resection for GSC is possible, and is an effective way to improve the prognosis of GSC. Even in stage IV GSC, radical resection can still prolong the survival time. It is necessary for the patients with benign gastric diseases who received partial gastrectomy to carry out the endoscopy follow-up, especially in patients with Billroth II reconstruction procedure at 15-20 years.</p>

Dual cell seeding to improve cell retention on polytetrafluoroethylene grafts / 中华外科杂志

<p><b>OBJECTIVE</b>To improve cell retention on the graft with dual cell seeding technique, adding a layer of smooth muscle cells (SMCs) between the graft and endothelial cells (ECs).</p><p><b>METHODS</b>Polytetrafluoroethylene (PTFE) grafts pretreated with fibronectin were seeded with SMC followed by ECs one day later and exposure to an in vitro flow system. The number of ECs on grafts was counted under microscope.</p><p><b>RESULTS</b>After exposure to the flow for 1 hour, 61% of the ECs lost when the ECs were seeded alone, whereas only 27% of the ECs lost when the ECs were seeded on the top of SMCs. Preconditioning of a cell seeded graft in a low rate flow did not improve cell retention when late exposure to a higher rate flow.</p><p><b>CONCLUSION</b>This in vitro study indicates that using SMCs as a media layer between ECs and graft surface can improve the retention of seeded ECs on PTFE graft.</p>