Polymer hydrogels composed of highly hydrated crosslinked network mimic the composites of the cartilage extracelular matrix and are embedded with articular chondrocytes not only to support chondrocytes growth but also to promote chondrocytes proliferation and division which wil induce the cartilage regeneration and repair. OBJECTIVE:To review several kinds of natural polymer hydrogels and their newest progress and achievements. METHODS:Relative literatures from January 1994 to July 2013 were classified and analyzed by searching the databases through PubMed, Springer, Sciencedirect and Ovid databases using the keywords of “natural polymers, biodegradable polymers, hydrogel scaffold, articular cartilage, regeneration”.RESULTS AND CONCLUSION:Natural proteins (colagen, gelatin) and polysaccharides (chitosan, hyaluronic acid) are widely used as natural polymer hydrogels. The natural polymer hydrogels have not only the physical characters beneficial to articular cartilage regeneration, but also the important biological parameters, such as biocompatibility, low immunological response, low cytotoxicity and degradation. Meanwhile, the polymer hydrogels with natural origin can promote celladhesion, proliferation and division, and enhance the regeneration of new tissue. Moreover, they also can serve as carriers to sustain the release of drugs and growth factors. Al in al, natural polymer hydrogels have a potential application in articular cartilage regeneration and repair.

Objective To develop a new designed Kirschner wires guider for patellar fracture,and to evaluate its clinic outcomes.Methods From October 2010 to November 2015,totally 72 patients with patellar fracture were detected for this study.Divided them into 3 groups, named as the second-generation guider group,the first-generation guider group and the control group.And then evaluated the clinic outcomes in treatment of patellar fracture of the 3 groups.Results The surgery time,accuracy of placement needle position of the second-generation guider group were better than the other two groups with significant statistical differences (P <0.01).And the clinic outcomes of the first-generation guider group were better than the control group,and the differences were statistically significant (P <0.05).Conclusion The second-generation Kirschner wires guider is reasonable in design and convenient for use.Moreover,it can improve the accuracy and quality of surgery,reduce the operation time,and enhance the clinical effects.

Objective To explore an effective way for medical students and young surgeons learning operative approach .Methods A total of 50 medical students and young surgeons in our hospital were detected for this study .They were randomly divided into the BOOK class (group A) and the 3D computer class (group B) to learn the course of anthropotomy.After learning each section, they were examined to-gether on fresh corpse , and the examined results of the two groups were compared and assessed .Results In the general surgery examina-tions, there was no difference in the examined results with no statistically significant difference (P>0.05).But in the orthopedics examina-tions, the difference of intra-group comparison both in group A and group B were of statistical significance (P<0.05), and the results of group B were better than group A with statistically significant difference (P<0.05).Conclusion For the general surgical approach learn-ing, both of the two methods could achieve good effect .For the orthopedics surgical approach learning ,it can receive better results through computer software ,but it still cannot achieve the ideal effect ,which indicates that the teaching through fresh corpse could not be replaced yet .

Objective To test the biomechanical properties and evaluate the feasibility of the new developed external fixator system,so as to provide reliable theoretical basis for further clinical research.Methods The tibia of 10 fresh male cadaver were made into fracture model.In order to fix the fracture of tibia,experimental group were treated with the new developed external fixator system and the control group were treated with the Hoffman 2 external fixator which was used in clinic commonly.Then axial compression and horizontal torsion test were made on tibia fracture model.The test results were recorded and statistically analyzed.Results There was no statistical difference on the aspect of the ability to resist axial compression and horizontal torsion between the experimental group and the control group(P >0.05). The new developed external fixator system could meet the criterion in clinical application.Conclusion The new developed external fixation system can meet the requirement of biomechanics on fixing the fracture of bone,and it can greatly simplify and diversify the clinical applica-tion of external fixation device.

Objective To develop a newly designed guide and evaluate its clinic application prospect in treatment of patella fracture. Methods In our mechanical experiment, we carried out the tensile test of the two generation drilling guides by biomechanics machine and then analyzed the difference in their deformation. In the corpse experiment , we transversed fractures at the equator of the patella obtained from 10 fresh cadaver speci-mens. They were divided into 2 groups randomly: a test group and a control group. The second-generation of the aiming guide was used for the test group but not for the control group during the experiment. Then we evaluated its clinic application in the treatment of patella fracture. Results In the mechanical experiment, the displace-ment of the first generation guide was significantly larger than that of the newly one. The accuracy in the place-ment of k-wires by the second generation guide was significantly higher than by the first generation guide (P <0.05). Conclusions The drilling guide is reasonable in design and convenient in use. Moreover, it can improve the accuracy and quality of insertion of tension-band wiring of patellar fractures. The second-generation one is better and thus it is worth clinically spreading.

Objective To screen and identify the recombinants from the cDNA library of the adult Paragonimus west-ermani (PwA) for immunodiagnosis and immunoprophylaxis. Methods PwA cDNA library was screened with the PwA antigen immunized rabbit sera(IRS) pre-absorbed by the extract of E. coli XLl-Blue. The recombinants from positive clones were amplified by PCR, sequenced and cut off by KpnI/BarnHI and, then sub-cloned into pRESETB vector. The fusion protein was expressed,analysed by SDS-PAGE and identified by Western blotting with immune rabbit serum against worm antigen of Paragonimus westerrnani. Results The inserted cDNA fragment from the positive clone Pw-2 was about 800 bp, which contained an open reading frame(ORF) encoding Pw pre-procathepsin L belonging to cysteinase family. Expression product of Pw-2 was a fusion protein of 32 kDa, which can be recognized by immune rabbit serum against worm antigen of Paragonimus 晈esterrnani. Conclusion A recombinant plasmid Pw-2 encodes Pw pre-procathepsin L is constructed.

Objective: To design the ribozymes to cleave human TIMP 1 mRNA, and embed them into U 6snRNA to make them stable. Methods: Ribozymes were designed according to the “hammerhead structure” described by Symons.Computer was used to analyze the possible cleavage sites. Results: Three ribozymes targeting the nt123, nt299 and nt353 on TIMP 1 mRNA were designed. Embedding ribozyme in U 6snRNA had little effect on its binding with the substrate. Conclusion: Computer assisted design is indispensable in studying ribozyme. Embedding ribozymes in U 6snRNA may be a good way to solve the problems existing in ribozyme study. [

OBJECTIVE Toobservetheeffectoftemozolomide(TMZ)incombinationwithtetran-drine(TET)on cell viability,colony formation,migration and cell apoptosis of human glioblastoma U87 cells.METHODS TheviabilityofU87cellstreatedwithTET(8-64μmol·L-1),TMZ(50-400 μmol·L-1 )and TMZ combined with TET (3.2,6.4 μmol·L-1 )was detected by cytotoxicity assays with Cell Counting Kit-8 (CCK-8),the colony formation was detected by Giemsa staining,cell migration ability was detected by Transwell migration assay,cell apoptosis was assayed by flow cytometry using Annexin Ⅴ /PI double staining,and the expression of apoptosis-related proteins expression was detec-tedbyWesternblotting.RESULTS ThedataofCCK-8showedthatTET(r=0.903,P<0.05)orTMZ (r=0.995,P<0.05)could inhibit U87 cell viability alone in a concentration-dependent manner.The cell viability inhibition rate of U87 cells by TMZ co mbined with TET was higher than by TMZ or TET alone. Data showed that the effect of TMZ combined with TET was additive.TMZ 100 μmol·L-1 inhibited U87 cell colony formation and migration ablility compared with normal control.The inhibition rate of U87 cells by TMZ 100 μmol·L-1 combined with TET (3.2 and 6.4 μmol·L-1 )was more significant than by TMZ alone (P<0.05).Compared with TMZ alone,TMZ combined with TET (3.2 and 6.4 μmol·L-1 )signifi-cantly down-regulated the expression of anti-apoptotic protein Bcl-XL,but significantly up-regulated the expression of cleaved caspase 3 protein and cleaved poly(ADP-ribose)polymerase.CONCLUSION TET combined with TMZ can inhibit U87 cell viability,colony formation and migration by activating caspase-dependent apoptotic pathway,resulting in apoptosis.

Objective To investigate the inhibitory effect of aspirin on liver metastasis of colon cancer in mice and the possible mechanism.Methods A total of 32 BALB/C mice were injected with CT26 colorectal cancer cells to establish colon cancer liver metastatic model,with 3 mice dead,15 mice in control group and 14 mice in experimental group.The control group was given saline 0.2 mL/d,the experimental group were given aspirin 30 mg/kg.The liver weight and the number of metastatic tumors were calculated after 30 days of intervention.HE and CD31 staining was performed by immunohistochemistry to observe the metastasis and angiogenesis.The protein expression of VEGF and cox-2 were analyzed by Western blot.Results The average liver weight and number of liver metastases nodules in the experimental group were significantly lower than those in the control group(P<0.05).Pathological examination showed that the experimental group of mice the number of liver cells and liver tumor angiogenesis were significantly less than the control group(P<0.05).Western blot showed that the expression of VEGF and cox-2 of CT26 cells were down-regulated after treated with aspirin.Conclusion Aspirin can down regulate the protein expression of VEGF and cox-2 protein to inhibit liver metastasis of colon tumor proliferation and angiogenesis,thereby inhibiting metastasis of colon cancer cells,for therapeutic purposes.

Objective To investigate the role and mechanism of platelet in the development of salt-sensitive hypertension.Methods 25 Dahl salt-sensitive rats (Dahl SS) were divided into three groups: low-salt diet (0.12% NaCl, LS), high-salt diet (8%NaCl, HS) and high-salt diet + platelet inhibitor (8%NaCl+busulfan, HS+bus).Blood pressures were measured by tail-cuff method.After six weeks, animals were sacrificed.Platelet p-selectin expression, platelet cytosolic Ca2+ concentration, platelet-leukocyte aggregation (PLA) in peripheral blood, and immune cells infiltrated on aortic walls were assessed by flow cytometry, and serum IL-6 level was tested by ELISA in vivo.Platelets purified from SD rats were treated with normal salt (0.9%NaCl) and high salt (1.3%NaCl), then the cytosolic Ca2+ concentration and p-selectin expression of platelet were detected.Results We found that Dahl SS rats with high-salt diet, relative to low-salt diet, presented with high blood pressure and increased the ratio of platelet p-selectin expression, Ca2+ concentration.IL-6 level and PLA in peripheral blood, and the number of infiltrated immune cells on aortic walls were also significantly elevated in high-salt diet group.The whole events were ameliorated by the platelet inhibitor busulfan.Cytosolic Ca2+ concentration and p-selectin expression were also increased in purified platelets treated with high salt than those treated with low salt (P < 0.05).Conclusions Our findings suggest that high salt induced platelet activation with increased Ca2+ concentration may play an important role in the development of salt-sensitive hypertension via vascular inflammation.However, the detailed mechanisms of platelet activation and development of high blood pressure via inflammation induced by high salt intake remain to be determined.