BACKGROUND:Mechanical factors play an important role in wound healing and scar formation. Finite element model is established to stimulate, analyze and optimize different sutures, which has become a hotspot to guide surgies accurately. OBJECTIVE:To analyze the stress distribution of different simple interrupted suturing directions on the skin wound by establishing the skin finite element model, and to provide basic data for the study of scar formation. METHODS:Porcine back skin uniaxial tensile test was performed to provide reference for the mechanical properties of human skin. Orthotropic skin wound model was established using ABAQUS to calculate the stress distribution on the wound in different suturing directions. RESULTS AND CONCLUSION:The anisotropic mechanical properties of skin wound influenced the suture stress significantly. The elastic modulus along the Langer’s line was larger than that in the vertical direction. The stress increased orderly in the Langer’s line direction, the Langer’s line deflected 30°, bias Langer’s line 45° and vertical Langer’s line. These results suggest that the clinical incision should be made along the Langer’s line direction. Additional y, the cut at an angle with Langer’s line can also reduce the stress of suture.

Objective To study the activation induced cell death(AICD) in peripheral blood T lymphocytes(PBL T) from patients with chronic hepatitis B(CHB), and the role of AICD in the pathogenesis of chronic hepatitis B. Methods The PBL Ts of 14 patients were isolated with negative selection by magnetic beads, and cultured with or without anti CD3 mAb in the presence of PMA and ionomycin. The apoptosis of PBL T was observed by TUNEL staining and assessed by Flow Cytometry. Results In CHB patients, the apoptotic rate of PBL T activated with anti CD3 mAb was significantly higher than that of without activation (16.73%?0.99% vs. 9.74%?1.14%, P 0.05), and a negative correlation existed between the level of INF? and apoptotic rate of T cell( r =-0.87126, P

Objective To test whether urinary sulfur excretion can be used as an accurate indicator of the catabolism of sulfur amino acid in growing newborn piglets. Methods Using a well-nourished enteral nutrition piglet model,we tested whether intravenous inorganic sulfate and methionine were fully excreted as sulfur in the urine. Results Recovery rate of inorganic sulfate and methionine as total sulfur in urine were 95.6% and 105.5%, respectively. Conclusions Detection of urinary sulfur, as a non-tracer and noninvasive method, may be employed to accurately measure the catabolism of sulfur amino acid in the growing piglet model.

ObjectiveTo examine whether Shenfu injection (SFI) reduces post-resuscitation myocardial dysfunction in a pig model by modulating expression imbalance of transcription factors of regulatory T cell, namely GATA-3 and T-bet.Methods Thirty pigs were randomly divided into sham group (n = 6) and cardiopulmonary resuscitation (CPR) group (n = 24) according to the random number table method, and the pigs in the CPR group were randomly subdivided into normal saline (NS) group, epinephrine (EP) group, and SFI group (n = 8 per group). After 8minutes of untreated ventricular fibrillation (VF) followed by 2 minutes of CPR, animals in three groups respectively received central venous injection of either 20 mL SFI (1.0 mL/kg, SFI group), EP (0.02 mg/kg, EP group) or NS (NS group). Blood samples were obtained before VF and 0.5, 2, 6 hours after restoration of spontaneous circulation (ROSC), and the parameters of hemodynamics and oxygen metabolism were determined. Surviving pigs were sacrificed at 24 hours after ROSC, the pathological changes in myocardium were observed, the levels of interleukin-4 (IL-4), tumor necrosis factor-α (TNF-α) andγ-interferon (IFN-γ) were measured by enzyme linked immunosorbent assay (ELISA), and expressions of protein and mRNA of GATA-3 and T-bet were determined by Western Blot and quantitative real-time polymerase chain reaction (RT-qPCR), respectively.Results Six pigs of three resuscitation groups were successfully resuscitated. The CPR time, number of defibrillation, defibrillation energy, and ROSC time were significantly decreased in the EP and SFI groups compared with those in the NS group. Compared with the sham group, the parameters of left ventricular systolic function and oxygen metabolism were significantly decreased, myofibril organelles were extensively damaged, and progressive and severe deterioration of the myocardium was found, and mitochondrial structure was not recognizable in the NS group; the level of IL-4 in myocardium were markedly decreased, while that of TNF-α, IFN-γand IFN-γ/ IL-4 [reflecting helper T cell 1/2 (Th1/Th2)] were significantly increased. Protein and mRNA expressions of GATA-3 were markedly reduced in the myocardium of pigs in the NS group compared with that of the sham group at 24 hours after ROSC, while T-bet was significantly increased. Compared with the NS group, animals treated with SFI had minimal myocardial intracellular damage, with decreased heart rate (HR, bpm: 90.33±3.79 vs. 106.83±5.36) and increased mean arterial pressure (MAP), cardiac output (CO), oxygen delivery (DO2), and oxygen consumption (VO2) at 6 hours after ROSC [MAP (mmHg, 1 mmHg = 0.133 kPa): 107.67±1.96 vs. 86.83±1.85, CO (L/min): 2.47±0.08 vs. 2.09±0.04, DO2 (mL/min): 364.31±4.21 vs. 272.33±3.29, VO2 (mL/min): 95.00±2.22 vs. 82.50±2.28, allP<0.05]. Compared with the NS groups at 24 hours after ROSC, level of IL-4 was markedly increased in myocardial cells (ng/L: 33.80±3.06 vs. 16.15±1.34,P< 0.05), while the levels of TNF-α, IFN-γ and IFN-γ/IL-4 were lowered significantly [TNF-α (ng/L): 18.16±0.71 vs. 29.64±1.89, IFN-γ (ng/L): 373.75±18.36 vs. 512.86±27.86, IFN-γ/IL-4: 16.15±1.34 vs. 33.80±3.06, allP< 0.05], and myocardial T-bet protein and mRNA expressions were reduced [T-bet protein (gray value): 0.41±0.07 vs. 0.59±0.11, T-bet mRNA (2-ΔΔCt): 4.37±0.21 vs. 7.57±0.55, bothP< 0.05], furthermore, myocardial GATA-3 protein and mRNA expressions were significantly up-regulated in SFI group [GATA-3 protein (gray value): 0.25±0.07 vs. 0.16±0.07, GATA-3 mRNA (2-ΔΔCt): 0.63±0.07 vs. 0.34±0.05, bothP< 0.05]. The parameters in SFI group were significantly improved compared with those of the EP group.ConclusionsMyocardial immune dysfunction is induced by Th1/Th2 imbalance following myocardial injury subsequent to CPR in pigs. SFI can attenuate myocardial injury and regulate myocardial immune disorders, protect post-resuscitation myocardial injury by modulating expression imbalance of transcription factors GATA-3 and T-bet.

Objective To investigate the role of Toll like receptor 4/nuclear factor-κB (TLR4/NF-κB) signal pathway on myocardial dysfunction after cardiac arrest-cardiopulmonary resuscitation (CA-CPR) in animal model. Methods Twenty-six pigs were randomly divided into sham group (n = 6), CA-CPR 12 hours group (n = 10) and CA-CPR 24 hours group (n = 10). The model of CA-CPR was reproduced by endocardial electrical stimulation for 8 minutes followed by CPR, and the pigs in sham group were only given anesthesia and tracheal intubation. The changes in hemodynamics including mean arterial pressure (MAP) and cardiac output (CO), as well as morphology and ultrastructure of myocardial cells were observed before and after CPR. The levels of serum tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) were determined by enzyme linked immunosorbent assay (ELISA), and protein and mRNA expressions of TLR4/NF-κB in the myocardium were determined by Western Blot and real-time fluorescence quantitative reverse transcription-polymerase chain reaction (RT-PCR), respectively. Results Hemodynamic disturbance and myocardial serious injury were observed in CA-CPR groups. Compared with sham group, the levels of serum TNF-α were markedly increased 0.5 hour after return of spontaneous circulation (ROSC) in CA-CPR 12 hours and 24 hours groups (pg/L: 62.49±6.66, 48.39±2.37 vs. 10.75±0.74, both P < 0.05), and peaked at 2 hours (pg/L: 70.93±5.51, 66.03±2.60 vs. 10.87±0.91, both P < 0.05) followed by a gradual decline. The levels of serum IL-6 at 0.5 hours after ROSC in CA-CPR 12 hours and 24 hours groups were markedly higher than those of sham group (pg/L: 14.42±1.99, 11.23±1.12 vs. 8.75±0.74, both P < 0.05), and peaked at 12 hours (pg/L: 36.50±2.91, 38.15±1.26 vs. 8.88±0.62, both P < 0.05) followed by a gradual decline. The protein expressions of TLR4 and NF-κB in the myocardium were significantly increased in CA-CPR 12 hours and 24 hours groups as compared with sham group [TLR4 protein (gray value): 0.11±0.03, 0.24±0.05 vs. 0.05±0.02; NF-κB protein (gray value): 0.27±0.04, 0.24±0.03 vs. 0.09±0.02, all P < 0.05]. The mRNA levels of TLR4 in CA-CPR 12 hours and 24 hours groups were increased by approximately (9.93±1.07) folds and (9.21±1.27) folds of sham group respectively, and NF-κB mRNA expressions were increased by (4.44±0.96) folds and (6.09±0.81) folds of sham group respectively (all P < 0.01). Conclusion Activation of TLR4/NF-κB signal pathway may be one of the main pathological mechanisms of post resuscitation myocardial injury in a porcine model of CA-CPR.

Objective To summarize complications and early clinical effect of less invasive stabilization system and the femoral condylar support plates in treatment of AO type C distal femoral fractures. Methods We reviewed 46 patients who had internal fixation of AO type C distal femoral fractures. Of all 46 patients, 25 were with less invasive stabilization sys-tem and 21 were with femoral condylar support plates fixation. Comparative analysis was performed using intraoperative in-dex, postoperative complications and the Evanich score at follow-up. Results All 46 patients were followed up with a mean time of 19.6 months after surgery. The difference in incision length, blood loss, fracture healing time was significant between the 2 groups(P＜0.05)but not in the duration of operations and hospital stays(P>0.05). The statistical signifi-cance was also found in the total incidence of postoperative complications and the Evanich score at the last follow-up(P＜0.05). Conclusion Patients with less invasive stabilization system fixation had the characteristics of less trauma, shorter fracture healing time, less postoperative complications and better functional recovery compared with femoral condylar sup-port plates. Less invasive stabilization system had became an ideal internal fixation in treatment of AO type C distal femoral fractures.

Objective To summarize the clinical features,diagnosis,treatment and prognosis of hepatolithiasis complicating cholangiocarcinoma. Methods From June 1958 to March 2011,709 cases of hepatolithiasis were admitted to Department of General Surgery,Peking University Third Hospital.The cases concomitant with cholangiocarcinoma were reviewed. Results 20 of 709 (2.8％ ) hepatolithiasis cases developed cholangiocarcinoma.17 cases (85％,17/20) were followed-up for 2 years (0 - 15 years).The hepatolithiasis course before the malignant diagnosis was 15 ± 1 1 years (3 -38 years).14 cases had frequent episodes of cholangitis,15 cases had liver cirrhosis.Preoperative diagnosis was established by CT,MRCP,B-ultrasound and tumor markers in 55％ (11/20) cases.4 cases underwent radical resection,7 received palliative resection,9 cases received conservative treatment.In radical resection,one lost to follow-up,one survived one year,two for 5 years.In palliative resection,2 lost to follow-up,two survived one year,one survived 3 years, one for 5 years. None in conservative group survived more than one year.Conclusions Cholangiocarcinoma developed from hepatolithiasis with a long history,frequent cholangitis,liver cirrhosis,especially in cases with imige showing thickness of bile duct or mass and rising tumor markers (CA19-9,CA125,CEA).The cases undergoing radical resection may have a favorable prognosis.

Objective To confirm whether in post-resuscitation myocardial dysfunction involved in myocyte apoptosis mechanism in porcine model of cardiac arrest and apoptosis index varied from different modalities of cardiopulmonary resuscitation or not.Methods A total of 22 WZSP inbred small swine were randomly (random number) divided into sham operation group (SHAM) (n =6),defibrillation first group (DF,n =8) and chest compression first group (CF,n =8).Eight minutes after ventricular fibrillation was set up,standard CPR was carried out subsequently after defibrillation in porcine models of cardiac arrest in DF group and defibrillation after standard CPR in CF group,and hemodynamics were monitored.Twentyfour hours after restoration of spontaneous circulation (ROSC),animals were sacrificed,and myocardial specimens were examined with electron microscopy,Western blot,quantitative RT-PCR,and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay.The experimental data were analyzed by SPSS 17.0.Student's t test was employed for comparisons between two groups.Differences within groups at different time intervals were compared with repeated measures ANOVA.A two-tailed value of P ＜ 0.05 was considered statistically significant.Results Myocardial function was significantly impaired after ROSC.Levels of Bcl-2,Bax and caspase-3 protein was markedly increased in the CF and DF groups than those in the SHAM group (P ＜ 0.05) at 24 h after ROSC,while Bcl-2/Bax was significantly reduced in the CF and DF group compared with the SHAM group (P ＜ 0.05),and much more apoptotic cells were observed in cardiac arrest animals in comparison with sham-operation animals (P ＜ 0.05).Six hours after ROSC,hemodynamic indicators improved significantly in group DF than those in group CF,but Bcl-2,Bax and caspase-3 protein levels and apoptotic index were not significantly different bewteen the DF group and CF group (P ＞ 0.05).Conclusions Caspase-3-mediated apoptosis might be one of the main pathological mechanisms of postresuscitation myocardial injury in a porcine model of cardiac arrest,but there was no statistically significant difference in apoptosis index between two resuscitation modalities,showing no one modality was superior over another.

Objective To study the role of imbalance between transcription factors GATA-3 and T-bet expressions in causing acute lung injury after resuscitation in cardiac arrest model of swine.Methods Mter swine model of electrically induced cardiac arrest was established for 8 minutes,animals were resuscitated to get restoration of spontaneous circulation (ROSC).The swine with ROSC were randomly assigned to be sacrificed at 12 and 24 h after ROSC (n =8 in each group).CD3 +,CD4+ and CD8 + lymphocyte subsets were determined by flow cytometry,and the levels of serum IL-4,TNF-α,and IFN-γ were measured by using ELLSA.The protein levels and expressions of GATA-3/T-bet mRNA were detected in lung tissue by western blotting and quantitative real-time PCR device,respectively.Results Pulmonary function was significantly impaired after ROSC.CD4 + lymphocyte subsets (28.4 ± 2.3) ％,(24.1 ± 1.6) ％ and CD4 +/CD8 + (1.7 ±0.9),(1.5 ± 1.0) were significantly lower in the post-ROSC group compared with the sham-operated group (48.4±2.9)％,(51.1±5.4)％ (2.5±1.3),(2.7±1.1) (P＜0.05) at 12 h and 24 h after ROSC.The levels of serum IL-4 and TNF-α were markedly increased,while IFN-γ and IFN-γ/IL-4 were significantly decreased in the post-ROSC group compared with the sham-operated group (P ＜0.05) at 2-12 h after ROSC.Protein level and expression of GATA-3 mRNA in lung tissue were markedly increased,while those of T-bet were significantly reduced in the post-ROSC group compared with the sham-operated group (P ＜0.05) at 12 and 24 h after ROSC.Conclusions The lung immune dysfunction induced by imbalance between transcription factors GATA-3 mRNA and T-bet mRNA expressions may complicate in the process of post-resuscitation lung injury in a porcine model of cardiac arrest.

Objective To study the bowel-cleansing efficacy, patient security and mucosal injury of low-volume PEG plus ascorbic acid regimen. Methods Five hundred patients referred for colonoscopy were enrolled and randomly divided into two groups. Group A received low-volume PEG regimen, Group B received sodium phosphate (NaP) regimen for bowel preparation. Patients of the two groups drank solution 5 h before colonoscopies, serum creatinine and electrolyte were monitored at 5 h and 3 h before colonoscopies. The bowel-cleansing efficacy was rated during colonoscopy. All mucosal injuries observed during colonoscopy were biopsied and histopathologically reviewed. Results The patients of group A completed bowel preparation of 233 cases, completed colonoscopy 226 Cases, group B completed bowel preparation 238 cases, completed colonoscopy 210 cases. There was no significant difference in bowel cleansing between the groups (P > 0.05). Group A reported less incidence rate of the mucosal injuries than Group B. Group A reported better patient security than Group B at the same time. Conclusion Compared with sodium phosphate (NaP) regimen low-volume Polyethylene Glycol (PEG) plus ascorbic acid regimen exhibited equivalent bowel-cleansing efficacy and less incidence rate of the mucosal injuries and better patient security.