Objective To compare the transfection rate of AAV2-EGFP and AAV2/1-EGFP to human skin fibroblast(HFB).Methods Two recombinant adeno-associated viruses(AAV) encoding enhanced green fluorescent protein(EGFP) were constructed and transfected to HFB at multiple of infection MOI ranging from 104 to 106.Twenty-four hours after the infection,the expression rates of EGFP on cultured HFB were assessed by flow cytometry and the transfected cells were observed under fluorescence microscope.The killing effect of the virus on the infected cells was assayed by MTT.Results The transfection efficiency of AAV2-EGFP was increased as MOI increased.When MOI was 104,the transfection efficiency of AAV2-EGFP was 7.68%?1.18%;When MOI was 105,that was 52.12%?1.59%;When MOI was 106,that showed no significant increase.However,the transfection efficiency of AAV2/1-EGFP showed no obvious changes at any MOI.Conclusion AAV2 is more efficient than AAV2/1 in transfecting HFB,but neither AAV has a high transfection efficiency.

OBJECTIVE:To investigate the inhibitory effect of siRNA expression vector inhibiting human insulin-like growth factor 2(IGF2)gene on the proliferation of hepatoma cell line Huh-7. METHODS:siRNA expression vector pGL3-hAFP-hTERT-siRNA3(“siRNA3”)which inhibited IGF2 gene by dual promoter regulation of recombinant human alpha-foetoprotein(hAFP)and human telomerase reverse transcriptase(hTERT)was transfected into the Huh-7 cell and normal hepatocyte L-02,and then a nega-tive control group(vector pGL3-hAFP-hTERT)and a blank control group were set up. IGF2 mRNA expression was detected by re-al-time fluorescent quantitative polymerase chain reaction 48 h after transfection into the cells in all groups;the activity of the cells by the microplate reader 0,24,48 and 72 h thereafter;and the cell cycle and apoptosis by the flow cytometer 48 h thereafter,and the changes in the protein levels of IGF2,PCNA,Cyclin E2,Cyclin D2,Cdc2 and Bcl-2 in the cell were detected by Western blot. RESULTS:Compared with the negative control group and blank control group,IGF2 mRNA expression in the Huh-7 cell transfected with siRNA3 was obviously weaker;at 48 and 72 h after transfection,the activity of Huh-7 cell signigicantly reduced, Huh-7 cells at G1 phase obviously increased and those at S phase markedly decreased;the occurrence of early,late and total apopto-sis in Huh-7 cells apparently increased,and the protein expression of IGF2,PCNA,Cyclin E2,Cyclin D2,Cdc2 and Bcl-2 in cells significantly weakened,with statistically significance(P<0.01 or P<0.05). No obvious change in the above-mentioned index-es could be found in L-02 cells transfected with siRNA3 expression vector (P>0.05). CONCLUSIONS:siRNA which inhibited IGF2 gene by dual promoter regulation of recombinant hAFP and hTERT can specially inhibit IGF2 gene expression and the prolifer-ation of Huh-7 cells,which may be involved with down-regulated protein expression of cell proliferation-associated gene PCNA, cell cycle control-associated genes Cyclin E2,Cyclin D2 and Cdc2 and apoptosis regulation-associated gene Bcl-2 as a result of down-regulated IGF2 mRNA expression and protein expres-sion.

Objective To investigate the xenotransplantation model of fetal pig skin precursor tissue and its development after transplantaion. Methods Porcine skin precursor tissue was obtained from the embryo of gestation day 56 (E56), and made into microskin or stamp skin graft. The microskin was transplanted to the dorsal wound in BALB/c nude mice, then covered with human corpse skin. The stamp skin graft was imbedded subcutaneously into the back of nude mice, and microskin was injected subcutaneously into the auricles of nude mice. Their growth and development were observed and they were examined by HE staining at 6th and 12th week after transplantation respectively. Two-sample t test was used to analyze the size of newly grown skin tissue. Results Porcine skin precursor tissue graft in three models above survived and continued growth after transplantation, and growth ability of the dorsal wound transplantation model was significantly stronger than that of the auricle model. Epidermis and hypodermis were detected in newly grown skin tissues. Hair follicles, a few of sebaceous glands, but no sweat glands were observed in auricle model, while many sebaceous glands and sweat glands were observed in the dorsal wound model. Conclusion Transplantation of microskin to dorsal wound is the optimal model of investigating the xenotransplantation of fetal pig skin precursor tissue and its development after transplantion.

Objective:To evaluate the role of hippocampal hemeoxygenase-1 (HO-1) in electroacupuncture (EA)-induced reduction of lipopolysaccharide (LPS)-induced brain injury in mice.Methods:Twenty-four healthy adult C57BL/6J mice of both sexes, weighing 18-22 g, were divided into 4 groups ( n=6 each) using a random number table method: control group (group C), LPS-induced brain injury group (LPS group), LPS plus EA group, and LPS plus EA plus HO-1 inhibitor zinc protoporphyria (ZnPP) group (LPS+ EA+ ZnPP group). A virus carrying calcium ion fluorescent probes was injected into and an optical fiber was implanted into the hippocampal CA1 region to record changes in the calcium fluorescence signals.Three weeks later, Baihui, Quchi and Zusanli acupoints were stimulated with constant voltage (2/15 Hz) and disperse-dense waves for 30 min once a day for 5 consecutive days, and the stimulation intensity was defined as less than 1 mA causing slight muscle contraction.ZnPP 50 μmol/kg was intraperitoneally injected at 12 h before each stimulation in LPS+ EA+ ZnPP group, and the equal volume of normal saline was given instead in the other groups.After the end of EA stimulation on the last day, LPS 5 mg/kg was intraperitoneally injected to induce brain injury.Open field tests were performed at 1 day after LPS injection to record the number of rearing and amplitude of neuronal calcium signals during rearing.Novel object recognition tests were conducted at 3 days after LPS injection, and the exploration index and amplitude of neuronal calcium signals while exploring novel objects were recorded.The mice were sacrificed after the end of behavioral testing, and the brain tissues were obtained and stained by Nissl, and the neurons in the hippocampal CA1 region were counted. Results:Compared with group C, the number of rearing and amplitude of calcium signals in neurons in the hippocampal CA1 region during rearing were significantly decreased, the exploration index and amplitude of calcium signals in neurons in the hippocampal CA1 region while exploring novel objects were decreased, and the neuron counts were reduced in LPS, LPS+ EA and LPS+ EA+ ZnPP groups ( P<0.05 or 0.01). Compared with group LPS, the number of rearing and amplitude of calcium signals in neurons in the hippocampal CA1 region during rearing were significantly increased, and the exploration index and amplitude of calcium signals in neurons in the hippocampal CA1 region while exploring novel objects were increased in group LPS+ EA ( P<0.05), and no significant change was found in the parameters mentioned above in group LPS+ EA+ ZnPP ( P>0.05). Compared with group LPS+ EA, the number of rearing and amplitude of calcium signals in neurons in the hippocampal CA1 region during rearing were significantly decreased, and the exploration index and amplitude of calcium signals in neurons in the hippocampal CA1 region while exploring novel objects were decreased in group LPS+ EA+ ZnPP ( P<0.05). Conclusion:The mechanism by which EA reduces LPS-induced brain injury is related to the activation of the endogenous protective mechanism HO-1 in mice.

This paper introduces the failure phenomenon, failure analysis, maintenance process and method of SIEMENS PRIMUS linear accelerator.
Particle Accelerators ; Radiotherapy Dosage

Objective: To summarize the experience of reoperations on patients who had late complications related to previous aortic surgery for Stanford type A dissection. Methods: From August 2008 to October 2016, 14 patients (10 male and 4 female patients) who underwent previous cardiac surgery for Stanford type A aortic dissection accepted reoperations on the late complications at Department of Thoracic and Cardiovascular Surgery, Nanjing Hospital Affiliated to Nanjing Medical University. The range of age was from 41 to 76 years, the mean age was (57±12) years. In these patients, first time operations were ascending aorta replacement procedure in 3 patients, ascending aorta combined with partial aortic arch replacement in 4 patients, aortic root replacement (Bentall) associated with Marfan syndrome in 3 patients, aortic valve combined with ascending aorta replacement (Wheat) in 1 patient, ascending aorta combined with Sun′s procedure in 1 patient, Wheat combined with Sun′s procedure in 1 patient, Bentall combined with Sun′s procedure in 1 patient. The interval between two operations averaged 0.3 to 10.0 years with a mean of (4.8±3.1) years. The reasons for reoperations included part anastomotic split, aortic valve insufficiency, false aneurysm formation, enlargement of remant aortal and false cavity. The selection of reoperation included anastomotic repair, aortic valve replacement, total arch replacement and Sun′s procedure. Results: Of the 14 patients, the cardiopulmonary bypass times were 107 to 409 minutes with a mean of (204±51) minutes, cross clamp times were 60 to 212 minutes with a mean of (108±35) minutes, selective cerebral perfusion times were 16 to 38 minutes with a mean of (21±11) minutes. All patients survived from the operation, one patient died from severe pulmonary infection 50 days after operation. Three patients had postoperative complications, including acute renal failure of 2 patients and pulmonary infection of 1 patient, and these patients were recovered after treatment. Thirteen patients were finally recovered from hospital. The patients were followed up for 16 to 45 months, and no aortic rupture, paraplegia and death were observed in the follow-up. Conclusions Patients for residual aortic dissection after initial operations on Stanford type A aortic dissection should be attached great importance and always need emergency surgery, but the technique is demanding and risk is great for surgeons and patients, which need enough specification and accurate on aortic operation. More importantly, the Sun′s procedure also should be performed on the treatment of residual aortic dissection or distal arch expansion, and obtains the short- and long-term results in the future.

Objective    To analyze the clinical effect of partial aortic root remodeling for root reconstruction on Stanford type A aortic dissection. Methods    From January 2010 to December 2015, 30 patients (25 males, 5 females) underwent partial aortic root remodeling for root reconstruction on Stanford type A aortic dissection with involvement of aortic root. The range of age was from 27 to 72 years, and the mean age was 51.2±8.0 years. The proximal aortic dissection received partial aortic root remodeling, and the operation procedures included partial aortic root remodeling+ascending aortic replacement in 9 patients, partial aortic root remodeling+ascending aortic replacement+hemi-arch replacement in 6 patients, partial aortic root remodeling+ascending aortic replacement+Sun's procedure in 15 patients. The patients were followed up for 10 to 60 months with a mean of 37.9±3.2 months. Preoperative and postoperative degrees of aortic regurgitation were compared. Results    All patients survived from the operation, and one patient died from severe pulmonary infection 15 days after operation. The overall survival rate was 96.7% (29/30). One patient died during the follow-up. Two patients underwent aortic valve replacement in the 12th and 15th postoperative month respectively because of severe aortic regurgitation (AI). Up to the last follow-up, trivial or no aortic regurgitation was demonstrated in 24 patients, but mild aortic regurgitation occurred in 2 patients. Conclusion    The surgical treatment for aortic root pathology due to Stanford type A aortic dissection is challenging, and partial aortic root remodeling operations could restore valve durability and function, and obtains the early- and mid-term results.