This paper introduces a typical network framework based on VPN.With emphasis on network's security and stability,it describes how to construct a remote network based on Internet with VPN by focusing on such facts as security,service quality and expansion,etc.Finally,some natures about VPN both in technique and security are shown.

Objective To study the best extraction method for Radix Salvia Miltiorrhiza effective component. Methods Several extraction methods for Radix Salvia Miltiorrhiza (water decoction, alcohol reflux, ultrasonic extraction and supercritical CO2 extraction) were compared, to optimize the extraction methods by determined of Danshensu and Tanshinone IIA of Radix Salvia Miltiorrhiza. Results Supercritical CO2 extraction had high content of effective component of Danshensu and Tanshinone IIA. Conclusion Supercritical CO2 extraction was the best extraction method for Radix Salvia Miltiorrhiza. This result would be an experimental proof for pre-processing the preparation of Radix Salvia Miltiorrhiza.

Radiation proctitis is one of the complications after radiotherapy for pelvic malignancies.Surgery is not necessary for the most of radiation proctitis.However, surgery is unavoidable when rectal obstruction, uncontrollable bleeding, and fistula occur. This article reviews the progress in surgical treatment of radiation proctitis.

[Objective]To discuss the result of using latissimus dorsi musculocutaneous flap which function was recovered by repairing the thoracodorsal nerve with nerve transfering for reconstruction of flexor of elbow or digits in brachial plexus injury patients.[Method]From march 2000 to June 2003,eight patients with brachial plexus total roots avulsion were treated by mlutiple donor nerves transfer.The function of latissimus dorsi muscle recorved well but not the biceps muscle in five patients.The function of flex digits did not recover while the latissimus dorsi muscule recorverd well in three patients.All of them had the aid of latissimus dorsi musculocutaneous flap to reconstruct the flexor of elbow or digits.[Result]The patients were followed up for one year to half past three years,all of musculocutaneous flap were survived,the muscle strenght graded 3 to 4 and the active motion of the elbow was over 100 degrees in flexion and 10 degrees to 25 degrees in extension.All the digits can grasp,the fist closure was about 2 cm and the muscle strenght was grade 3 of the involved digits.[Conclusion]It is a good method to reconstruct the flexor of elbow or digits by the recovered latissimus dorsi musculocutaneous flap in brachial plexus total roots avulsion patients.When treating brachial plexus total roots avulsion patients,it is necessary to repair the thoracodorsal nerve.

[Objective]To investigate the morphological characteristic of the scalenus minimus. [Methods]Totally 32(64 sides) embalmed adult cadavers were dissected and studied,the morphology of scalenus minimus and its relationship to brachial plexus was observed.Ten scalenus minimus were stained by HE to study membrane of the muscles.Twenty-seven(54 sides) embalmed adult cadavers were dissected carefully to investigate its nerve and blood supply.[Results]Scalenus minimus was found in 84.4% of cadavers(54/64).Its insertion was mainly composed of tendinous tissue,which was spaned by the lower trunk of brachial plexus.Scalenus minimus supply nerve branches was from ventral rami of the cervical seven root,and vascular supply was from:(1) branches of deep cervical artery,(2) branches of subclavia artery.[Conclusion]Scalenus minimus muscle,an independent but inconstant muscle,is existed in most people and sometimes responsible for compression of brachial plexus.It is suggested that scalenus minimus muscle should be resected carefully as well as scalenus anticus and medius during surgical treatment of thoracic outlet syndrome.

Objective To compare medium-term therapeutic effect by bilateral and unilateral puncture plasma coblation nucleoplasty(PCN) in the lumbar disc herniation patients. Methods 90 cases confirmed no significant rupture of annulus fibrosus of lumbar disc herniation by CT or MRI were randomly divided into two groups. Bilateral and unilateral puncture plasma coblation nucleoplasty groups were respectively divided into group A and group B, and compared the JOA scores. Results 82 patients were followed up for 10 ～ 32 months,the average follow-up time was 16.2 months. Preoperative JOA scores of the two groups were not statistically significant(P ＞ 0.05) but the postoperative follow-up JOA scores were higher than preoperative(P ＜0.05) and the JOA scores of group A were higher than group B(P ＜0.05). Conclusion The medium-term therapeutic efficacy of bilateral puncture coblation nucleoplasty was superior to unilateral therpy.

Objective To evaluate the efficacy of Grosse Kempf interlocking intramedullary nailing (Grosse Kempf IIN) and AO plate in the treatment of tibial fractures. Methods A retrospective analysis was done on the recovery of 55 cases with tibial fractures treated with the Grosse Kempf IIN (Group A) and 40 treated with AO plate (Group B) from 1994. Results The 10 26 months follow up showed that the healing rate and the infection rate were 98.2% (54/55) and 1.8% (1/55) respectively in the Group A with a mean healing time for 5.6 months and 90.0% (36/40) and 12.5% (5/40) respectively in the Group B with a mean healing time for 7.5 months. Conclusions The Grosse Kempf IIN has obvious advantage of excellent biodynamics, reliable fixation, simple operation, less trauma on regional blood supply and is more effective in the treatment of tibial fractures than the AO plate. Nevertheless, I IN itself has limitation for further application.

Objective To explore the transcription pattern of ND1, ND2 and mtTFA gene in the myocardial cells and intestinal epithelial cells of rats after hemorrhagic shock. Methods Total RNA of myocardial cells and intestinal epithelial cells in rats were extracted after hemorrhagic shock. ND1, ND2, and mtTFA gene transcription levels were measured by reverse transcription and polymerase chain reaction (RT PCR). Results During the period from 1 to 2 h after hemorrhagic shock, the ND1 gene transcription levels in myocardial cells in the hemorrhagic shock groups were higher than that in the normal control group, but the levels in intestinal epithelial cells were lower than that in the normal control group. The pattern for the changes of ND2 gene transcription in myocardial cells and intestinal epithelial cells was basically similar. Conclusion There might exist certain tissue differences in the changes of ND1 gene transcripts in myocardial cells and intestinal epithelial cells of rats with hypoxic and ischemic damage.

Objective To investigate exogenous PTEN gene transfected human breast cancer cell line MDA MB 468. MethodsUsing the lipofectamine 2000 transfection technique,wild type PTEN gene was transducted into an in vitro cultured highly metastatic breast cancer cell line MDA MB 468.After transfection, the cells were selected by G418.Then resistant clones were chosen and expanded in DMEM culture medium. RT PCR, immunohistochemical method and western blot were used to determine the expression of target genes. ResultsAn anti G418 cell clone was established and expanded in culture. The transfected PTEN gene MDA MB 468 cells showed expression of PTEN mRNA and PTEN protein. ConclusionHuman breast cancer cell line MDA MB 468 established in this study expresses consistently exogenous PTEN genes.

Objective To investigate the effects and mechanisms of bile on small intestine mucosal barrier.Methods Fifty Wistar rats were assinged into 3 groups randomly: obstructive jaundice(OJ) group(n=20),biliary external drainage group(n=20) and control group(n=10).Ten days after operation,the plasma endotoxin level was determinated,the terminal ileum mucosas was obtained to be morphologically measured by light microscope,and immunohistochemistry and Western blot were uesd to examine the expressions of tight junction proteins zona occludens-1(ZO-1) and occludin in the mucosas.Results Atrophy significantly appeared in the distal ileum mucosas in OJ group.Compared with control group,the intestinal villus height,mucosa thickness and crypt depth in OJ group were obviously decreased 27.8%,21.7%,and 25.4%(P=0.001,0.001,0.040).There were no differences between external drainage group and control group(P=0.050,0.070,0.080);While the values of external drainage group were significantly higher than those in OJ group(all P=0.001).The level of plasma endotoxin was up to(1.49?0.27) EU/ml in OJ group compared with control group((0.27?0.09) EU/ml),P=0.001.In external drainage group,the value was(0.91?0.25) EU/ml,which was obviously higher than that in control group and lower than that in OJ group(all P=0.001).Immunohistochemical study showed strong positive expression of ZO-1 dropped from 7/10 in the control group to 6/20 in OJ group(P=0.040),occludin expression was 8/10 in control group and 7/20 in OJ Group(P=0.020);expressions of them in external drainage group(8/20(P=0.100,0.210) and 9/20(P=0.060,0.200)) displayed no significant differences compared with the other twogroups.Quantitative testing of Western blot showed the expressions of ZO-1 and occludin in OJ group were significantly lower than those in control group(P=0.001,0.010),the values in external drainage group were higher than those in OJ group(P=0.005,0.014).The expression of ZO-1 was lower in external drainage group than that in control group(P=0.001),and there was no significant difference of occludin between the two groups(P=0.062).Conclusion Lack of intestinal bile will undermine the intestinal tight junction protein composition,and make intestinal mucosal barrier impaired.The intestinal barrier more severely injured when biliary tract obstructs because of multiple factors.Bile plays an important role in the maintenance of intestinal mucosal barrier.