New antibiotics with novel modes of action and structures are urgently needed to combat the emergence of multidrug-resistant bacteria. Bacterial signal peptidase I (SPase I) is an indispensable enzyme responsible for cleaving the signal peptide of preprotein to release the matured proteins. Increasing evidence suggests that SPase I plays a crucial role in bacterial pathogenesis by regulating the excretion of a variety of virulent factors, maturation of quorum sensing factor and the intrinsic resistance against beta-lactams. Recently, breakthrough has been achieved in the understanding of three-dimensional structure of SPase I as well as the mechanism of enzyme-inhibitors interaction. Three families of inhibitors are identified, i.e. signal peptide derivatives, beta-lactams and arylomycins. In this article, we summarize the recent advance in the study of structure, activity and structure-activity relationship of SPase I inhibitors.

Objective To discuss and evaluate the value of insertion of inferior vena cava filter in treating lower extremity deep venous thrombosis(DVT).Methods Inferior vena cava filters were placed in 46 patients with lower extremity DVT prior treatment,20 in which were treated by therapy with anticoagulation and thrombolysis,and therapy with pressure gradient,and the other 26 patients by operation and thrombolysis therapy,and therapy with pressure gradient.Whether patients occurred pulmonary embolism was observed and the form and site of filters were monitored by periodic fluoroscopy.Results Inferior vena cava filters were placed successfully in all patients,38 cases were implanted permanence inferior vena cava filter,8 cases were implanted temporary inferior vena cava filter.Symptoms and signs of DVT disappeared or remitted in 44/46 patients after treatment.None of pulmonary embolism was occurred.Follow up 2-24 months(average 13 months) for 36 cases with permanence inferior vena cava filter,there was no complication of the filter and pulmonary embolism occurred.Conclusions The method of inserting inferior vena cava filter is simple and safe,which can prevent pulmonary embolism effectually to offer sufficient safeguard for the treatment of DVT.

Objective In a large-scale clinical medical examination, A2 type best multiple-choice test questions to the same knowledge were used respectively in simple and complex form, to compare the difficulty and discrimination indices of the two forms of test questions and provide evidence to the improve-ment of clinical medical examination. Method In a large-scale clinical medical examination more than 4000 candidates participated, and 20 questions to different knowledge points were randomly selected and used in the examination respectively in simple and complex A2 type best multiple-choice test questions. The difficulty and discrimination indices of the two forms of test questions were compared. Results The average difficulty coefficient of the 20 simple test questions (65.5 words per question in average) is 0.6829, and the average discriminative powers are 0.2675 and 0.2579 respectively using identification index method and point biserial correlation method. The average difficulty coefficient of the 20 complex test ques-tions (135.5 words per question in average) is 0.7095, and the average discriminative powers are 0.3065 and 0.2967 respectively using identification index method and point biserial correlation method. Conclusion To the same knowledge points, the average difficulty of complex A2 type best multiple-choice test questions is slightly lower than the simple ones, while the average discriminative power is increased in the complex questions. The complex A2 type test questions are of higher quality and more in line with the requirements of the medical entrance examination, medical education and examination reform.

Objective To evaluate short-term curative effect of endovascular abdominal aortic aneurysm repair. Methods Twelve cases of infra-renal abdominal aortic aneurysms were checked. Results The av-erage bleeding in the operation was 245 millimeter, the avenage hospitalization time was 8.6 days, and the average abrosia time was 1.5 days. White blood cell, hemoglobin, thrombocyte, hepatic function, and renal function were in the normal limits. Prothrombin time and activated partial thromboplastin time were post-poned after operation, and recovered normally within one week. Complications of operations were as follows:1 case of pulmonary infection, 2 cases of abdominal distention, and 1 case of intraoperafive endoleak. The former two kinds of complications alleviated after conventional treatment, and the latter disappeared naturally after 3 months. Conclusion Endovascular abdominal aortic aneurysm repair is safe, mini-invasive, and has little disturbance for body internal environment.

Objective To evaluate 11C-MDA,a cardiac sympathetic nerve presynaptic molecular probe,in acute myocardial ischemia (AMI) and to compare with 13N-Ammonia myocardial perfusion imaging.Methods Twelve Bama miniature pigs were used to establish AMI models.11C-MDA and 13N-Ammonia PET/CT were performed before and after model establishment.The defect fraction,ratio of defect to normal region,defect volume of 11C-MDA and 13N-Ammonia PET/CT were calculated.Paired-t test and twosample t test were used.Results Eight models were established successfully and 4 pigs died.The defect fractions on 11C-MDA and 13N-Ammonia myocardial imaging were significantly different (13.4±3.3 vs 7.4±1.0,18.8±4.4 vs 4.8±1.0,10.5±4.2 vs 4.4±0.9;t values:4.901,8.864,4.030,all P＜0.001) at the first,third and sixth month post-model establishment.The ratios of defect to normal region on 11C-MDA and 13N-Ammonia PET/CT myocardial images were significantly different (0.47±0.14 vs 0.59±0.10,0.43±0.13 vs 0.61±0.09;t values:-2.166,-3.415,both P＜0.05) at the first and third month post-model establishment.The defect volumes on 11C-MDA and 13N-Ammonia PET/CT were significantly different ((4.20±0.34) vs (2.55±0.11) cm3,(10.66±0.71) vs (2.46±0.12) cm3,(5.95±0.50) vs (2.44±0.11) cm3;t values:12.925,32.149,19.440,all P＜0.001) at the first,third and sixth month post-model establishment.Conclusions Myocardial ischemia-reperfusion and cardiac sympathetic restoration might occur at different times.The recovery of myocardial ischemia-reperfusion is earlier than that of the cardiac sympathetic nerve.

Objective To study the anatomic features of surface vasa vasorum on longissimus in thoracolumbar segments,and its protection function during the internal fixation for thoracolumbar fracture via Wiltse approach.Methods From March 2010 to October 2012,a total of 97 patients with thoracolumbar fractures underwent posterior internal fixation with pedicle screw system.The trend and distribution of surface vasa vasorum on longissimus in thoracolumbar segments were observed in the operation,and the vessels were protected during the surgical procedures by using specific devices and techniques.Operative time and intra-operative blood loss were recorded.Visual analogue scale (VAS) values were evaluated after 3 days,1 month,6 months postoperatively,and 1 month after the removal of internal fixation.MRI images of longissimus in thoracolumbar segments were compared after preoperative and postoperative 6 months.Results Surface vasa vasorum distribution on 194 longissimus and 402 inter-pedicle areas of 97 patients were observed.In 402 areas,94.3％ of surface vasa vasorum presented sarciniform,while only 5.7％ of surface vasa vasorum presented tube shape.In 379 areas of sarciniform distribution,9.8％ of blood vessel bundles were located in vertebral pedicle area;76.0％ of blood vessel bundles were located in the upper inter-pedicle areas;12.4％ of blood vessel bundles were located in middle inter-pedicle areas;1.8％ of blood vessel bundles were located in lower inter-pedicle areas.In 379 areas,87.3％ of blood vessel bundles could be completely retained;12.7％ of blood vessel bundles were treated by electro coagulation and burning.Intra-operative blood loss was 21±9.3 ml.VAS values after 3 days,1 month,6 months postoperatively,and 1 month after the removal of internal fixation were 3.3± 1.6,2.1± 1.4,1.2±0.7 and 1.1±0.7.The longissimus treated with electro coagulation demonstrated pimelosis change on MRI after postoperative 6 months.Conclusion Surface vasa vasorum on longissimus in thoracolumbar segments are generally of sarciniform,and most of them are located in upper inter-pedicle areas.The protection of vasa vasorum can reduce the intra-operative lesion and postoperative pimelosis change of longissimus.

Objective To study the effect of precise locating technique of C?arm fluoroscopy in order to reduce the radia?tion exposure during the surgical procdure for thoracolumbar fracture. Methods From March 2010 to Octorber 2012, a total of 92 cases with thoracolumbar fracture underwent postierior internal fixation procdures with pedicle instrumentation. C?arm fluoros?copy was used in 44 cases with precise locating technique, while in 48 cases with traditional methods. In precise locating group,C?arm fluoroscopy was used after anesthesia. Once an ideal view was got, the position parameters of C?arm fluoroscopy machine were recorded. The machine was positioned according to the recording for the secondary fluoroscopy. Pre?operative and intra?operative number of times of exposure, length of exposure time, time for fluoroscopy and total operating time were recorded and compared be?tween two groups. Results Pre?operative number of times of exposure, exposure time, and time for fluoroscopy in precise locating group were (5.51±2.47), (2.26±1.05) s and (9.83±3.67) min,which were higher than those of (4.02±2.42), (1.78±0.98) s and (8.29± 3.52) min in traditional group. However, intra?operative number of times of exposure, exposure time, and time for fluoroscopy in precise locating group were (5.26±3.64), (2.24±1.24) s and (10.39±4.82) min,which were lower than those of (9.74±4.38), (4.21± 2.38) s and (24.69±6.35) min in traditional group,and total number of times of exposure, exposure time, time for fluoroscopy and total operating time in precise locating group were(10.77±4.16), (4.50±1.83) s, (20.22±5.03) min and(70.52±18.33)min,which were also lower than those of (13.76±5.31), (5.99±3.27) s , (32.98±7.83) min and(81.86±21.57)min in traditional group. Conclu?sion Precise locating technique of C?arm fluoroscopy reduces the radiation exposure during the surgical procdure for thoracolum?bar fracture.

Objective: To establish a method for simultaneous determination of calceolarioside B and chlorogenic acid in Caulis Stauntoniae Chinensis tablets by HPLC.
Methods: The analysis was performed on a Thermo BDS HYPERSIL C₁₈ column (4.6 mm×250 mm,5 μm) maintained at 35 ℃. The mobile phase was consisted of methanol and 0.1% phosphoric acid solution, and gradient eluted with a flow rate of 1.0 mL·min^-1. The detection wavelength was 327 nm, and the injection volume was 10 μL.
Results: The linear ranges of calceolarioside B and chlorogenic acid were 0.51-20.60 μg·mL^-1 (r=1.000) and 0.52-20.63 μg·mL^-1 (r=1.000), respectively. The average recoveries were 100.3% with RSD as 1.1% and 105.9% with RSD as 1.4%, respectively. The content results of 5 batches of Caulis Stauntoniae Chinensis tablets were 0.083-1.115 mg·g^-1 for calceolarioside B and 0.161-1.204 mg·g^-1 for chlorogenic acid.
Conclusion: The method can be used for improving the quality evaluation standard of Caulis Stauntoniae Chinensis tablets.

Objective To assess the curative effect of percutem transilluminated with negative pressured on the potaried technique on the treatment of venous ulcer in lower extremity.Methods The clinical date of 300 cases involving 300 legs with venous ulcer in lower extremity,who underwent the percutum transilluminated negative pressured potaried technique using TRIVEXTM Ⅱ potaried system or the percutum transfixion surgical treatment from October 2005 to June 2009,were analyzed.Three hundred cases were randomly divided into potaried group and transfixion group.In potaried group,there were 190 cases involving 190 legs treated with TRIVEXTM Ⅱ potaried system.In transfixion group,110 cases involving 110 legs treated with percutum transfixion.The clinical indexes of skin infection rate and skin necrosis rate,shrinkage rate of wound area and skin depigmentation rate,ulcer healing rate and ulcer recurrence rate were calculated to assess the clinical curative effect on day 5,day 20,day 120 and day 360 after operation respectively.Results The rates of skin infection and skin necrosis were significantly decreased in potaried group compared with transfixion group on day 5 after operation (P0.05).Ulcer recurrence rate was remarkably lower in potaried group than that in transfixion group on day 360 (P

A plane, three-dimensional chamber of pulsatile-flow-cultivation and the liquid store chamber connected by medical silica gel tube were designed and constructed by ourselves according to the design principle. The rotator pump of cardiopulmonary bypass unit was acted as the power source. The mixed gas containing 5% CO2 and 95% air was supplied through the ventilation orifice of the liquid store chamber. The temperature of these components was stabilized by thermostatic waterbath. The test of biomechanics and biological compatibility for the system was carried out by cultures experiment during two weeks. The results of the experiment showed that there was no leak in the pulsatile-flow-cultivation components in which the concentration of CO2 was controlled about 5%+1%, the temperature at 37 +/- 1 degree C, and the value of pH between 6.8 and 7.5. The flow rate of the system could be adjusted exactly between 0.125 L/min and 6.0 L/min. The endothelial cells on the viable homograft valve increased about 10 times after being cultured for 2 weeks. The cultures of cell and mould taken from the leaf and Dacron cloth of homograft valve were reported to be negative. The results of the experiment demonstrated that there was satisfactory homeostasis of these components in effective modeling pulsatile-flow-field for the implantation cells cultured, proliferated, and remodeled under the condition inferior or superior to physiological level in vitro. The system can meet the need for study of pulsatile-flow-cultivation and tissue engineering heart valve constructed in vitro.
Biocompatible Materials ; chemistry ; Biomechanical Phenomena ; Cells, Cultured ; Computer Simulation ; Endothelial Cells ; cytology ; Heart Valve Prosthesis ; Humans ; Models, Biological ; Prosthesis Design ; Pulsatile Flow ; physiology ; Tissue Engineering ; methods ; Tissue Scaffolds