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 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 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 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 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 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 assess clinical features and treatment of angiosarcoma.Methods A retrospective study was carried out among seven patients hospitalized for angiosarcoma in the Department of Plastic Surgery,Zhongshan Hospital of Fudan University from January 2004 to March 2012.Clinical behaviors,therapeutic strategies and outcomes of angiosarcoma were analyzed in these patients.Results Of the seven patients,four were male,and three were female,with a median age of 67 years (range,37-77 years).Clinical presentations were various,including irregular ulcerous nodular masses in four patients,localized ulcer in one patient,and irregular erythematous nodules in two patients.All the patients were treated surgically with or without postoperative adjuvant therapy.Pathological examination revealed various degrees of differentiation and atypia of tumor cells,as well as obvious proliferation of endothelial cells,and all of these patients were diagnosed as angiosarcoma.Immunohistochemical analysis revealed a positive staining for CD31 and CD34.After surgical treatment,angiosarcoma recurred in four patients with the median time to the first recurrence being 3.5 months (range,1-6 months),cerebral metastasis occurred in one patient 5 months later,and two patients died.Conclusions Angiosarcoma is a rare and heterogeneous sarcoma with diverse clinical presentations.Local wide resection is the cornerstone of angiosarcoma treatment,and adjuvant therapy may improve its prognosis.

Objective To identify high-risk group among gastric cancer patients treated with curative resection and more than D1 dissection, and investigate the indications for proper adjuvant therapy.Methods 297 patients who met the following enrolled criteria were retrospectively analyzed:treated between January 2002 and December 2004, primary gastric or gastroesophageal cancer, underwent curative gastrectomy and more than D1 lymphadenectomy, pathologically staged as T3-4N0-1M0,or TxN2-3M0.The overall survival (OS), disease-free survival (DFS), local-regional recurrence-free survival (LRFS) and distant metastasis-free survival (DMFS) were calculated, and possible prognostic factors were analyzed.Results The median follow-up time was 61 months.The follow-up rate was 92.3%.The 5-year OS, DFS, LRFS and DMFS were 57.9%, 52.2%, 70.6% and 71.7%, respectively.Four independent prognostic variables identified for OS, DFS, LRFS and DMFS using multivariate analysis were Borrmann type (Ⅰ+Ⅱ/Ⅲ+Ⅳ), total number of dissected lymph nodes (>18/≤18), number of positive lymph nodes (0-3/≥4), and 6th AJCC TNM stage (Ⅱ+Ⅲ a/Ⅲ b+ⅣM0)(χ2=3.94-16.34,P<0.05).If one unfavorable prognostic factor was scored as 1, according to the total scores of the four prognostic factors, four risk groups were generated as low (score:0), low-intermediate (score:1), high-intermediate (score:2) and high risk group (score:3 or 4).The 5-year OS, DFS, LRFS and DMFS were 85.7%, 61.0%, 58.6% and 38.6%(χ2=31.20,P<0.01) in low risk group, 85.2%, 61.3%, 48.1% and 31.8%(χ2=31.88,P<0.01) in low-intermediate risk group, 94.4%, 77.8%, 64.4% and 57.2%(χ2=18.36,P<0.01) in high-intermediate risk group and 87.9%, 75.0%, 74.2% and 55.5%(χ2=19.30,P<0.01) in high risk group.Conclusions Even with R0 resection and more than D1 lymphadenectomy, the outcome was poor for gastric cancer patients with two or more unfavorable prognostic factors.Prospective study is warranted to evaluate the efficacy of adjuvant concurrent chemoradiotherapy for this group of patients.

Objective To evaluate the role of postmastectomy radiotherapy in four subgroups of high-risk breast cancer patients, who were grouped by the status of estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor 2 (Her-2). Methods A total of 437 invasive breast cancer patients with T3-4N1 or N2-3 and available immunohistochemistry results of ER, PR and Her-2 were retrospectively analyzed. Patients were classified into 4 subgroups according to hormone receptors (ER or PR, Rec) and Her-2 status:Rec-/Her-2-(triple negative), Rec-/Her-2 +, Rec +/Her-2 + and Rec +/Her-2-. Rec-was defined as ER-and PR-. Rec + was defined as ER + and/or PR +. Her-2 positive was defined as Her-2 + + or Her-2 + + +. End points were isolated locoregional recurrence (LRR), distant metastasis (DM), disease-free survival (DFS) and overall survival (OS). Results The median follow up time was 48 months. Sixty-nine (15. 8%) patients were Rec-/Her-2-, 62 (14. 2%) Rec-/Her-2 +, 89 (20.4%) Rec +/Her-2 + and 217 (49.7%) Rec +/Her-2-. 480(93.4%) patients received chemotherapy and 352(80. 5%) received radiotherapy. Radiotherapy significantly reduced the 5-year LRR rates of all the four subgroups (Rec-/Her-2-: 13.1% vs. 33. 3%, Rec-/Her-2 + :9. 3% vs. 21.2%, Rec + /Her-2 + :9. 7% vs. 47.0%, Rec +/Her-2-:3. 2% vs. 15.4%). Radiotherapy significantly lowered the 5-year DM rates (26. 7% vs. 49.4%, 27.6% vs. 67. 5%, 18.4% vs. 100%) and improved the 5-year DFS rate (66. 7% vs. 33. 3% , 67.7% vs. 33. 3% , 72. 6% vs. 0%) as well as OS (73.9% vs. 25.2% ,69. 8% vs.41.5%, 91.0% vs. 32. 8%) of patients with Rec-/Her-2-, Rec-/Her-2 + and Rec +/Her-2 +. Conclusions In high-risk breast cancer patients, all subgroups of patients grouped by ER, PR and Her-2 status can benefit from postmastectomy radiotherapy.