A preliminary study of side population cells in human gastric cancer cell line HGC-27.

BACKGROUND: Cancer stem cell-like side population (SP) cells, which may be responsible for recurrence, tumor metastasis, and resistance to cancer therapy, have been identified and characterized in several types of cell lines from gastric cancer. However, there is no report on isolation of SP cells from human gastric cancer cell line HGC-27. This study aims to analyze the proportion of SP cells in HGC-27 cell line, differentiate SP from non-side population (NSP) cells, and determine whether the SP cells have certain biological properties of stem cells. MATERIAL AND METHODS: (1) HGC-27 suspension was prepared and stained with Hoechst33342 and PI for flow cytometric isolation of SP (2). Differences in proliferation and stemness-related gene expression profiles (CD133, CD44, OCT-4, MDR1, EpCAM, and ABCG2) between SP and NSP cells were detected by gastric formation assay and quantitative real-time PCR (3). Oncogenicity of SP and NSP cells was determined in nude mice in vivo. RESULTS: (1) SP cells accounted for 0.1-1.0% of HGC-27 cells, and decreased to 0% after verapamil inhibition. Using flow cytometry, we sorted 7.5×105 SP cells and most HGC-27 cells were NSP cells (2). Gastric formation assay and MTT demonstrated that there was a significant difference in proliferation between SP and NSP cells. Gene expression analysis showed that the expression of genes was significantly higher in SP cells (3). The oncogenicity experiment in nude mice revealed that 105 SP cells were able to form tumors, which demonstrated higher tumorigenicity than non-SP cells. CONCLUSIONS: These results collectively suggested that SP cells from HGC-27 cell line have some cancer stem cell properties and could be used for studying the pathogenesis of gastric cancer, which may contribute to discovery of novel therapeutic targets.

A biplanar robot navigation system for the distal locking of intramedullary nails.

BACKGROUND: Distal locking is the key procedure of the intramedullary nailing operation. It is difficult to precisely locate the locking path, and intraoperative radiation exposure is also a serious problem. The advantages and disadvantages of different approaches applied in this operation are summarized. METHOD: A biplanar robot navigation system for the distal locking of intramedullary nails is presented. The novel mechanical structure and the surgical process are introduced. Then the positioning accuracy of the robot is experimented and validated. RESULTS: The positioning precision of the biplanar robot is tested, and the average error is 0.24 mm. The tibia sawbone is used for distal locking to test the accuracy of the robot navigation system. The maximal deviation between the drilling centre and the nail hole centre is 0.44 mm. CONCLUSION: The biplanar robot has the advantages of high positioning accuracy, operational stability and safety. It can be used not only for the distal locking of intramedullary nails but also for other orthopaedic surgeries that demand precise positioning.

Geometric Modeling of Prosthetic Socket / 中国康复理论与实践

@#Objective To investigate the geometric modeling method for trans-femoral prosthetic socket. Methods The socket reference shapes (i.e. shape templates) were constructed based on the statistic analysis and integrated into the CASD program. The initial socket shape was obtained by transformation from the corresponding reference shape based on the data from the patient's stump and the final socket shape was determined by a kind of three-dimensional interaction method under the OpenGL environment. The fabrication experiment is conducted on the specialized numerical control machine. Results The interactive modification method was easy to use. The machined socket mold is consistent with the designed model in the shape and the precision. Conclusion This method can meet the clinical requirements in the main, but need to optimize the surface shaping characters and rules during the interactive modification stage.

Research progress of joint kinematics and kinetics / 生物医学工程学杂志

The development process of joint kinematics and kinetics is expatiated from the aspects of technology and method. Firstly, the classical mechanics-based methods are introduced. Secondly, the computer assisted methods are analyzed from the technical aspects of video tracking, fluoroscopy and MR imaging separately. Then the assistance of robotic technique in this field is discussed. Finally the potential trend in the joint kinematics and kinetics is concluded.

Tumor stem cells and gastric carcinoma / 中国组织工程研究

Adult stem cells have great differentiation plasticity as embryonic stem cells,can differentiate into other cells or tissues,and have been a hot research spot.This article mainly analyzed the occurrence of tumor stem cells,believed that tumor stem cells are the root of tumor growth,invasion,migration and relapsing,discussed stomach stem cells,tried to search the correlation of carcinoma and stomach stem cells,and analyzed that carcinoma may be a kind of stem cell disease.

The bi-planar navigation robot system: application for insertion of sacroiliac screws / 中华创伤骨科杂志

Objective To assess effects and security of the insertion of sacroiliac screws by the bi-planar navigation robot system. Methods In a simulated surgical setup, 12 AO cannulated screws were placed into the S1 vertebral bodies of 4 human pelvic bone under the guidance of the bi-planar navigation robot system which was developed jointly by Beijing Aeronautics and Space University and our hospital. To compare this new technique with the conventional technique, another 12 cannulated screws were placed into 4 Synbone pelvic models under fluoroscopic control. The fluoroscopic times, the radiation exposure time and operation time between image acquisition and guide-wire insertion were recorded. Results With the guidance of the bi-planar navigation robot system, the average fluoroscopic times were 2.5, the average radiation exposure time was 1.5 seconds, and the average operation time was 253 seconds. All the screws were in the safe area. Under the fluoroscopic control, the average fluoroscopic times were 20.3, the average radiation exposure time was 13.7 seconds, and the average operation time was 246 seconds. Two screws (16.7%) were misplaced. The fluoroscopic times and the radiation exposure time were reduced significantly when the bi-planar navigation robot system was used (P0.05). Conclusions The bi-planar navigation robot system can provide precise navigation for insertion of sacroiliac screws within several minutes, and reduce the radiation exposure to the patient and the staff significantly. The results of this prospectively controlled experimental study are encouraging for further clinical trials.

Isolation and identification of two new compounds from Erigeron breviscapus / 中草药

Object To investigate the chemical constituents of Erigeron breviscapus (Vant.) Hand. Mazz. (Compositae) Methods Compounds were isolated from the ethanolic extract with column chromatography and identified on the basis of spectral analysis (IR, EI MS, FAB MS, 1HNMR, 13 CNMR, 2DNMR) and physiochemical properties Results Two compounds were identified as 1 hydroxy 2,3,5 trimethoxy xanthone (Ⅴ), and 1 (2′ ? pyranone) 6 caffeoyl ? D pyranoglucose (Ⅵ) Conclusion Both of the two compounds were new Compound Ⅵ showed inhibitory effects on the adhesion of endothelial induced by TNF ?, indicating its protective effect against injury due to ischemic reperfusion

Lignans from Patrinia scabra / 中草药

Objective To study the lignans in Patrinia scabra. Methods The constituents were separated and purified by column chromatographies with silica gel, RP-silica gel, and Sephadex LH-20. Their structures were elucidated on the basis of spectral data (IR, MS, 1H-NMR , 13 C-NMR , DEPT, HMQC and HMBC). Results There were four lignans obtained from P. scabra with the structures identified as pinoresinol-4, 4′-di-O-?-D-glucopyranoside (Ⅰ), and matairesinol-4, 4′-di-O-?-D-glucopyranoside (Ⅱ), lariciresinol-4′-O-?-D-glucopyranoside (Ⅲ), and lariciresinol-4-O-?-D-glucopyranoside (Ⅳ). Conclusion All the four compounds are found in P. scabra for the first time. The NMR data of compound Ⅱ are given first.

Study on chemical constituents of Bletilla striata(I) / 第二军医大学学报

Objective: To study the chemical constituents of Bletilla striata (Thunb. ) Reichb. f. Methods: The con-stituents were separated and purified by column chromatography with silica gel and Sephadex LH-20,and were identified byspectral analysis. Results: Five compounds were identified as: 2, 7-dihydroxy-4-methoxy-9, 10-dihydrophenanthrene (1), 2, 7-dihydroxy-3, 4-dimethoxyphenanthrene (2), 3, 7-dihydroxy-2, 4-dimethoxyphenanthrene (3 ), 3', 3--dihydroxy--5-methoxybiben-zyl(4), p-hydroxybenzaldehyde (5), Conclusion: Compound 2, 3, 4 are isolated from this plant for the first time.