Aim To study the adaptive protection of H_2O_2 preconditioning against dopamine-induced damage in PC12 cells.Methods The apoptosis of PC12 cells was observed by electron microscope, PI stain flow cytometry (FCM) and Hoechst stain. The mitochondrial energy redox state was measured by MTT assay. The mitochondrial membrane potential(△?m) was investigated by the fluorescent probe of rhodamine 123.Results PC12 cells exposed to 50 ?mol?L -1 DA showed chromatin condensation and nucleus fragmentation observed by electron microscope. Exposure to DA (50 ?mol?L -1) for 24 h, the apoptosis of PC12 cells preconditioned by 10 ?mol?L -1 H_2O_2 for 90 min as measured by Hoechst stain was significantly decreased,compared with no-preconditioned cells. Exposure to 50,100,and 200 ?mol?L -1 H_2O_2 for 24 h, the proportion of apoptosis of PC12 cells was decreased from (20.9?1.8)%, (40.5?6.4)% and (88.1?3.9)% to (4.9?2.9)%, (12.0?1.4)%, (61.5?3.4)% after H_2O_2 preconditioning, respectively. By exposuring PC12 cells to 20,40,and 80 ?mol?L -1 DA for 24 h, the rates of MTT metabolism were reduced and the effect was prevented by H_2O_2 preconditioning. After 50 ?mol?L -1 DA exposure for 24 h,the mean fluorescence intensity of rhodamine 123 in no-preconditioned PC12 cells was decreased from (46.87?0.33) to (4.39?2.93),and that of preconditioned PC12 cells was decreased from (46.87?0.33) to (10.50?0.28). Conclusion H_2O_2 preconditioning possesses adaptive protection against dopamine-induced damage in PC12 cells.

Objective\ Treatment of spondylolisthesis using freeze dried femoral ring allografts plus morselled cancellous autografts (called as composite cortical ring) by anterior lumbar interbody fusion (ALIF). Methods\ Fourteen patients were treated by this procedure, there were six males and eight females. The age of the patients range from 40 to 56(average 46). Ten segments were of grade Ⅱspondylolisthesis, five segments were of gradeⅠ. Ten patients were treated with RF as internal fixation, four patients with short Harrington rod as internal fixation. Results\ The fusion rate and clinical results of ALIF were analyzed by comparing the findings on the X-ray films taken preoperatively and 6 months postoperatively as well as by JOA score. The fusion rate of 15 segments of 14 patients(two segments of 1 patient was fused) is 85.7%, the average improvement rate of JOA score is 73.3%at an average follow up of 26.6 months. Conclusion\ ALIF with composite cortical ring could successfully restore the spinal structure, maintain the interspace height distracted intraoperatively, obtain high fusion rate and excellent clinical results.\;

[Objective]To compare the purity and extraction rate of four purecollagen type I products prepared from various biomaterials by a limited enzyme digestion method for the use in tissue engineering.[Method]Bovine cortical bone, bovine achilles tendon, porcine achilles tendon and porcine skin were splitted into pieces of 0.2-0.5 mm. After being immersed in glacial acetic acid, they were extracted with pepsin. Then the crude products were dissolved, centrifuged, dialyzed and freeze drying to prepare pure collagen type I. The final products were confirmed by absorbance, amino acid analysis and'SDS-PAGE electrophoresis comparing them with the products of Sigma Company.[Result]The wave length of maximum absorbance of the final products was 230 nm, and the amino acid analysis and SDS-PAGE electrophoresis confirmed that the final products were collagen type I. The purity of product extracted from bovine cortical bone was the highest (96.12%) and higher than that from Sigma Company. The extraction rate of bovine achilles tendon collagen was the highest (75.34%).[Conclusion]Collagen type I of higher purity and higher extraction rate can be prepared using a limited enzyme digestion method.And the product from bovine cortical bone is better than the others,which has a promising prospect.

[Objective]To observe the biological properties of a novel collagen/hydroxyapatite composite scaffold in vitro and to evaluate the possibility of application being used in tissue engineering for osteochondral repair.[Method]The scaffolds were constructed of collagen I and hydroxyapatite.The pore size and interpores of the scaffold were observed by scanning electronmicroscopy(SEM).The porosity was measured by liquid displacement method.Rabbit bone marrow stromal cells(BMSCs) were isolated and amplified,then inoculated onto the scaffold.By SEM scanning,the condition of the cells adhering onto the scaffold was observed.The proliferation of the cells on the scaffolds was examined using MTT method,and the growth curve was drawn.[Result]The scaffold possessed high porosity and proper pore size.The pore diameter of the collagen layer was about 90?m,the pore diameter of the HA layer was about 120?m,and the overall porosity of the composite scaffold was 75%.The proliferation of the cells on the scaffold was good.[Conclusion]The novel collagen/hydroxyapatite composite scaffold possesses desirable pore structure and good biocompatibility,and it can be used in tissue engineering for osteochondral repair.

0.05).[Conclusion]The osteochondral scaffold of the collagenⅠ-sodium hyaluronate-fbrin glue tri-copolymer scaffold bonding with antigen-extracted bovine cancellous bone has an appropriate structure and a good biocompatibility,which makes it a useful scaffold in the osteochondral tissue engineering.

[Objective]To prepare a cartilage acellular matrix scaffold and to explore its feasibility in cartilage tissue engineering. [Methods]Microparticles about 100 ?m~154 ?m were prepared after calf cartilage physically shattered and experienced gradient centrifugation,and then treated by a modified Courtman's four-step method which was improved to produce acellular cartilage matrix.After this treatment the microparticles were made into 3% suspension which was placed into moulds.With the freeze-drying method,3-D cartilage acellular matrix (CACM) was prepared.The scaffolds were cross-linked by a neotype crosslinking agent genepin for 48h,and then placed into glycine solution server times for removing redundant genepin.The freeze-drying method was used to prepare CACM.The scaffolds were investigated by gross observation,histological staining (haematoxylin-eosin,toluidine blue) ,scanning electron microscope (SEM) observation and porosity measurement,water absorption rate and degradation rate analysis.After being cultivated for ten days,bone marrow stranal cells (BMSCs) of rabbit were seeded into the scaffold.MTT test and SEM were done to assess the growth and proliferation of BMSCs.[Results]Gross observation showed the scaffolds had a loosely porous and dark blue appearance after being cross-linked by genepin.The histological staining (haematoxylin-eosin,toluidine blue staining) showed that there were no chondrocyte fragments in the scaffold.The CACM scaffold had 90% porosity,(1314?337) % water absorption rate,and (13.69?7.3)% or (25.99?8.9) % degradation rate at 2 or 4 weeks.MTT test showed that BMSCs grew well in the 3-D CACM scaffolds of logarithmic trend,supporting that the scaffolds had no cytotoxic effect on BMSCs.SEM micrographs indicated that the scaffolds were porous and the cells covered the scaffolds firmly with cell processes.[Conclusion]The improved Courtman's four-step method makes a more thoroughly acellular scaffold.The 3-D CACM scaffold retains most of extracelluar matrix.After being cross-linked by genepin,the 3-D CACM scaffold has good biocompatibility and degradation rate of the scaffolds is decreased,which makes it a suitable carrier for cartilage tissue engineering.

OBJECTIVE:To provide scientific basis for the research quality of pharmacoeconomic on the domestic digestive system diseases.METHODS:The pharmacoeconomic research literatures published on professional academic magazines before2003were collected either by computer or by manual research,and which were then systematically evaluated.RESULTS:Some problems were found in the88pharmacoeconomic research literatures obtained,including the study perspective,design,result analysis and discussion of study.CONCLUSION:It is suggested a guideline for pharmacoeconomic research be made and the pharmacoeconomic research be further standardized,the academic exchanges and evaluation feedbacks be increased;meanwhile,personnel training should be emphasized for a better formulation of the related policies and the rational medication in the clinic.

This paper studied the protective effect of gypenosides (GPS) on oxidative damage of myocardium of guinea pig, Using xan-thine-xanthine oxidase (X-XOD) producing free radicals. In the isolated guinea pig papillary muscles, X- XOD produced the quick positive inotropism at first and then the continuous negative one, shortened the functional refractory period (FRP) and elevated the excitability and increased the automaticity induced by adrenaline, inhibited the activity of superoxide dismutase (SOD) and increased the content of malondi-aldehyde (MDA). GPS inhibited the negative inotropism of papillary muscles produced by X-XOD,resisted the changes of FRP, automaticity and excitability induced by X- XOD. Meanwhile, GPS antagonized the effect of X-XOD which decreased activity of SOD and increased the content of MDA. These studies indicate that GPS can protect the myocardium from oxidative damage.

Nuclear receptors pregnane X receptor (PXR) and constitutive androstane receptor (CAR) are originally characterized as transcription factors regulating many target genes. Recent works have revealed that these nuclear receptors play critical roles in regulating genes that encode drug metabolism enzymes and modulating hepatic energy metabolism, such as down-regulating gluconeogenesis, fatty acid oxidation, and ketogenesis, as well as up-regulating lipogenesis. Studies on PXR and CAR have important implication on drug-drug interaction (DDI) and potential disease treatment targets.

To investigate the optimum transfection condition in transfecting human keratinocytes with plasmid-liposome complexes in vitro,the cultured human keratinocytes at 60% ～ 100% confluences were exposed to the eukaryotic expression plasmid,pCMV*SPORT-β-gal,coated with LipofectAMINE in different DNA/liposome mixing concentration ratios.After cultured for another 48 hours following the ends of 6 ～ 24 hours exposures to the DNA-liposome complexes,the transfected human keratinocytes were visualized by β-galactosidase staining.Then,the transfection efficiency was determined by calculating the rate of β-galactosidase staining positive cells.β-galactosidase expression was showed clearly in human keratinocytes transfected with the DNA-liposome complexes.The highest efficiency was achieved with cultured cells at 80% and 90% confluences,demonstrating by the transfection rates of (31.35±1.35)% and (32.32±2.47)% respectively.Meanwhile,the essential transfection conditions for these efficiencies were in coating pCMV*SPORT-β-gal DNA of 1.5μg/100μL with LipofectAMINE of 12.5μL/100μL,and exposing the cells to the DNA-liposome complexes for 8 hours.These results indicate that LipofectAMINE could effectively transfer eukaryotic expression plasmid into human keratinocytes in vitro,for which the optimization of transfection conditions involve in cells growth state,DNA/liposome mixing concentration ratio,and exposure time of cells to DNA-liposome complexes.