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.

AIM: To investigate the effects of p27kip1 ge ne on DNA replication and protein synthesis in esophageal carcinoma cells. METHODS: Recombinant adenovirus Ad-p27kip1 was constructed and transf ected into esophageal carcinoma cell EC-9706, and its effects on DNA replication , protein synthesis and the growth of esophageal carcinoma cells were explored b y means of cell growth count, -TdR, -Leucine incorporation meth od and flow cytometry. RESULTS: The growth of esophageal carcino ma cells was inhibited obviously. The radioactive intensity of -TdR and -Leucine in Ad-p27kip1 group decreased significantly than that in contr ol group after EC-9706 transfection (P

Objective Objective To study the influence of NS-398,a selective cyclooxygenase-2 inhibitor on the radiosensitivity of human esophageal carcinoma cell line EC9706 cell. Methods EC9706 cell, highly expressing COX-2, had been incubated with NS-398 at 10、20、50 and 100??mol/L for 24?h or 48?h before irradiation ranging from 0 to 10?Gy. Cell survival was measured by a standard clonogenic assay after 8 days of incubation. Apoptotic percentage was measured by FCM and DNA fragmentation by agarose electrophronesis. Results The senstization enhancement ratios (ratio of D_q) in EC9706 cell were 1.11, 1.24, 1.40, 1.54 at 10, 20, 50, 100??mol/L of NS-398 for 24?h pre-incubation and 1.11, 1.27, 1.58, 1.67 for 48?h pre-incubation, which showed a dose-dependant and time-dependant manner. FCM analysis revealed a higher sub-G_1 cell peak in NS-398 group after irradiation. Agarose electrophronesis showed a marked ladder. Radiation-induced apoptosis was enhanced by NS-398 (P

AIM: To investigate the effect on growth and activity of telomerase in esophageal carcinoma cells by inhibiting ubiquitin-proteasome pathway(UPP). METHODS: The esophageal carcinoma cell strain Eca9706 was treated with MG-132 to inhibit its UPP specially. The effect of growth suppression on cells was evaluated with MTT assay, morphologic changes of cells were observed under microscope, cell cycle and apoptosis were detected by flow cytometry (FCM). DNA fragment analysis was used to confirm the presence of apoptosis. The activity of telomerase was detected. RESULTS: MG-132 had obvious inhibitory effect on the growth of Eca9706 cells in a dose and time-dependent manner. Obvious pathologic change of cells were observed under microscope, cells became round, small and exfoliating. The FCM analysis showed that the ratio of esophageal carcinoma cells of G_1 phase increased and a obviously apoptotic sub-G_1 peak was found. Agarose electrophoresis showed marked ladder. The activity of telomerase was obviously inhibited. CONCLUSIONS: MG-132 significantly inhibits the growth and the activity of telomerase of Eca 9706 cells. These findings indicate that inhibiting UPP is a new strategy for the treatment of esophageal carcinoma. [

OBJECTIVE:To investigate effects of ubiquitin-proteasome inhibitor MG-132on apoptosis and survivin expression of esophageal carcinoma cells.METHODS:The esophageal carcinoma cells Eca9706were treated with MG-132,the growth inhibitory rate was determined with MTT assay,apoptosis was detected by flow cytometry,expression of survivin was detected by immunocytochemical technique.RESULTS:MG-132had obvious inhibitory effects on the growth of gastric car?cinoma cells,IC 50 of24hrs,48hrs,72hrs and96hrs were120.2,18.1,—12.2,and—16.9?mol/L respectively;Treated with5.0?mol/L MG-132for24hrs,48hrs,72hrs and96hrs,apoptotic rates of cells were(3.1?0.4)%、(31.7?3.5)%、(50.4?4.8)%and(66.6?6.2)%respectively;Expression of survivin was high in esophageal carcinoma cells and it was decreased in cells treated with MG-132.CONCLUSIONS:MG-132can significantly inhibit the proliferation of esophageal carcinoma cells and induce apoptosis,which might be associated with down-regulated expression of survivin.

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 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 investigate the clinicopathological features, treatment and prognosis of neuroendocrine carcinoma of the breast.Methods:Clinical data of 26 patients with neuroendocrine carcinoma of the breast admitted to the Northern Jiangsu People's Hospital from July 2013 to Mar 2021 were analyzed.Results:All 26 cases were female, the average aged of (62.81±11.95) years, the first clinical manifestations were painless breast masses, the average size being of (23.34±9.47) mm. At the time of diagnosis, regional lymph node metastasis was found in 4 cases, 1 case developed distant metastasis. Most patients' were on stage Ⅱ by TNM staging, molecular typing was Luminal A, and invasive mammary carcinoma with neuroendocrine differentiation was most common, with positive rates of ER and PR of 96%, the positive rate of CgA and Syn were 69% and 100%, and there was not positive expression of HER2. All patients received surgical treatment, 25 patients underwent postoperative adjuvant therapy. Twenty-five patients were followed up for a median follow-up time of 39.50 months. During the follow-up, 3 cases developed distant metastasis, 1 case died, the mean survival time was (40.81±26.90) months, there was ao satistically significant difference compared with invasive mammary carcinoma ( t=1.291, P=0.209). The mean disease free interval is (39.96±27.58) months. The overall survival and disease free survival at 1, 2 and 5 years are 100%, 100% and 87%, respectively. Conclusions:Neuroendocrine carcinoma of the breast occurs more frequently in elderly women, often with large tumor size, low rate of regional lymph node and distant metastasis, moderate histological grade, early clinical stage, and the molecular typing is mostly Luminal A.The overall prognosis is fair.

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

Objective:To investigate the effects of tamoxifen on high glucose-induced epithelial-to-mesenchymal transition of rat peritoneal mesothelial cells and the underlying mechanism.Methods:The peritoneal mesothelial cells of normal male SD rats were selected between January 2015 and June 2016 and then cultured and divided into blank control, high-glucose stimulation and drug intervention groups. High-glucose stimulation group: primary cultured rat peritoneal mesothelial cells (RPMCs) were treated with 60 mmol/L high-concentration glucose to induce epithelial-to-mesenchymal transition. Drug intervention group: (1) RPMCs were treated with 60 mmol/L high-concentration glucose and different concentrations (0.5 μmol/L, 2 μmol/L) of tamoxifen. After 72 hours of stimulation, protein was extracted. (2) RPMCs were treated with 60 mmol/L high-concentration glucose and 2 μmol/L tamoxifen with or without 2 μmol/L ER-α antagonist for 1 hour to extract protein and for 6 hours to extract RNA. (3) RPMCs were treated with high-concentration glucose and 2 μmol/L tamoxifen with or without 1 μmol/L 1 μM proteasome inhibitor for 1 hour to extract protein. Western blot analysis was performed to analyze change in E-cadherin, α-SMA, Smad2, p-Smad2, Smad3, p-Smad3 and Smad4 protein. Real-time fluorescence quantitative PCR was performed to detect the change in mRNA expression of Smad2, Smad3, connective tissue growth factor and plasminogen activator inhibitor 1.Results:Tamoxifen attenuated epithelial-to-mesenchymal transition on RPMCs induced by high-level glucose, showing increased expression of epithelial cell marker E-cadherin and decreased expression of α-SMA in a concentration-dependent manner ( tE-cadherin = 2.31, tα-SMA =-2.53, both P < 0.05).TGF-β1/R-Smad signal pathway was activated by high-concentration glucose. Phosphorylation of Smad2/3 and mRNA expression of CTGF and PAI-1 were increased. Tamoxifen remarkably reduced protein and mRNA level of above mentioned protein and related target genes ( tp-Smad2 = -3.38, tCTGF = -3.81, P < 0.05), which could be blocked by ER-α antagonist. Finally, proteasome inhibitor could weaken the inhibitory effects of tamoxifen on p-Smad2/3 and increase p-Smad2/3 protein level ( tp-Smad2 = 3.94, P < 0.05). Conclusion:Tamoxifen activates ER-α on RPMCs, weakens the activation of TGF-β1/R-Smad signal pathway through decreasing p-Smad2 protein level, and effectively inhibits the progression of high-concentration glucose-induced epithelial-to-mesenchymal transition possibly through degrading p-Smad2 protein through proteasome. The role of tamoxifen in epithelial-to-mesenchymal transition may provide a possible guide for research, prevention and treatment of peritoneal fibrosis.