Objective: To investigate the feasibility of tracheal prosthesis made from biomaterials in the replacement of the circumferential tracheal defects. Methods: Surgical resection and replacement of the cervical trachea with different prosthesis was performed in 16 mongrel dogs. Bronchoscopic, roentgenographic, macroscopic and histopathologic examinations were employed to evaluate the efficacy of the tracheal substitutes. Results: In group A (with type-I prosthesis, n=8), one dog died from prosthetic dehiscence on 96th days postimplantation, another one died from anastomotic leakage caused by severe infection in cervical incision on postoperative 45th days. The other 6 of group A had uneventful postoperative courses and did not show any respiratory symptoms. Tracheal prostheses were completely healed with the recipient's trachea and combined in its integrity. Varied degrees of epithelial lining were observed to have formed near both the anastomotic ends. In addition, many scattered and varied sizes of neo-ossification substances were found at the sites surrounding implanted prostheses. In group B ( type-II prosthesis ,n=4), dehiscence and dislocation of implanted prostheses often occurred with time after operation, which inevitably resulted in severe and fatal postoperative complications .In group C (type-III prosthesis, n=4), all 4 dogs died within 28 days after operation. The leading causes of death were mesh exposure, collapse, infection and air leakage from implanted prosthesis itself. Conclusion: Type-I tracheal prosthesis is a suitable alternative method in reconstruction of tracheal defects, which appears very promising for the clinical application, with further improvements in promoting the epitheli alization completely.

Objective To investigate the distribution of hepatitis B virus (HBV) genotypes in patients with chronic HBV infections and the correlations of genotypes with liver fibrosis and hepatocellular carcinoma (HCC).Methods Serological,virological and pathological data of 190 patients with chronic HBV infections admitted to Hangzhou First People's Hospital during June 2007 and June 2012 were retrospectively analyzed.The series included 62 cases of chronic hepatitis B (CHB),60 cases of liver cirrhosis and 68 cases of HCC.HBV was genotyped by multiplex PCR,and subgenotyped by restriction fragment length polymorphism (RFLP).SPSS 11.0 was used for statistical analysis.Results Among 190 patients,61 were HBV genotype B (32.1％),126 were genotype C (66.3％),and 3 were B + C hybrid.HBV B2 (61/61,100.0％) and C2 (123/126,97.6％) were the major subgenotypes.HBV genotype B was more prevalent in CHB patients (46.8％,29/62) than in liver cirrhosis (20.0％,12/60) and in HCC patients (29.4％,20/68) (x2 =8.73 and 4.16,P＜0.01 or P＜0.05),whereas the prevalence of genotype C was higher in liver cirrhosis and HCC than that in CHB (x2 =9.54 and 4.17,P ＜0.01 or P ＜ 0.05).Patients with genotype C2 had higher serum hyaluronic acid level than with genotype B2 in 3 groups (t =2.685,2.433 and 2.015,P ＜ 0.01 or P ＜ 0.05).CHB patients with C2 infections had higher liver fibrosis grade than those with B2 (x2 =6.726,P =0.010),while there was no statistical difference in liver inflammation grade (x2 =0.601,P ＞ 0.05).HCC patients with B2 infection tended to have larger tumor diameter (≥5 cm) (x2 =7.231,P ＜ 0.01) and those with C2 infection were prone to be more serious cirrhosis (x2 =4.910,P ＜ 0.05).Conclusions HBV genotypes C2 and B2 are predominant in patients with chronic HBV infections in Hangzhou.HCC patients infected with HBV C2 may be complicated with more severe liver fibrosis,and those with HBV B2 infections may tend to have larger liver tumor.

Objective: To replace esophageal defects with artificially composed biodegradable materials and non-biodegradable materials. Met hods: A two-layered tube consisting of a collagen-chitosan sponge and an inner polyurethane stent was used to replace 5 cm esophageal segmental defect s in 15 dogs. The inner polyurethane stent was removed endoscopically at weekly intervals from 2 or 4 weeks. Results: Partial regeneration of es ophageal epithelia was observed in 5 dogs at week 2, and progressing constricti on occurred and the dogs became unable to swallow within 1 month. In the 10 dog s that the polyurethane stent was removed at week 4, regenerated esophageal tiss ue successfully replaced the defects, and complete epithelization was observed 1 month after surgery. Complete regeneration of esophageal mucosa structures, inc luding mucosal smooth muscle and mucosal glands were observed 3 months after surgery, and partial regeneration of esophageal muscle tissue was also observed 6 months after surgery. Conclusion: Our artificial prosthesis i n reconstruction of the cervical esophagus segment in dogs is feasible. Through temporary polyurethane tube, collagen-chitosan sponge provides a three-dimensi onal structure suitable for the regeneration and sufficient degradation time for the complete regeneration of esophagus.

Objective To evaluate hepatitis B virus large surfsce protein(LHBs) in monitoring of antiviral treatment.Methods LHBs.HBV serum markers and HBV DNA loads in 46 patients with adefovir dipivoxil(ADV) therapy were monitored for the whole course(60 weeks).Enzyme linked immunosorbent assay(ELISA),time differentiate immunofluoresence assay and real.time polymerase chain reaction(RT-PCR)were performed to detect LHBs,HBV serum markers and HBV DNA loads,respectively.And correlation analysis was also performed.Results Both LHBs and HBV DNA declined during the ADV treatment.and the correlation coefficient was 0.97.but LHBs declined after HBV DNA.There were 20 patients with HBV DNA<5×102/mL at 60th week.in which 8 were LHBs negative;in 14 recurrent patients,the HBV DNA turned to negative and became positive again,3 with negative LHBs;while in 12 patients resistant to the ADV therapy.2 were LHBs negative.Conclusion Dynamic monitoring of LHBs is useful in the evaluation of antiviral treatment.

Cytotoxicity and cytocompatibility remains the principal theme for biomaterials application in medicine. The purpose of this study was to investigate the cytotoxicity and cytocompatibility of collagen/hydroxyapatite(CHA) composite material in vitro in order to provide useful scientific basis for clinical use. Cellular cultivation in vitro and MTT assay were conducted for evaluating the composite material's influence on the morphology, growth and proliferation of cultured cell(L-929 cell). The hemolysis test was also performed for evaluating the impact on the function and metabolism of erythrocyte. These results demonstrated that the CHA composite material had no cytotoxicity and no hemolytic effect, and it might not be harmful to the morphology of the L-929 cell. The growth and proliferation of the L-929 cell could not be inhibited significantly. The cytotoxicity score of the composite material was grade 0. The hemolysis rate was 1.85%. In conclusion, collagen/hydroxyapatite (CHA) composite material might have good cytocompatibility and be safe for clinical use.
Animals ; Biocompatible Materials ; toxicity ; Cells, Cultured ; Collagen ; toxicity ; Hydroxyapatites ; toxicity ; Mice ; Prostheses and Implants ; Toxicity Tests ; Trachea

The medical-industrial fusion training model combines the knowledge and technology of medical and engineering disciplines in the training of oncology graduate students, which can help accurate diagnosis and treatment of tumors, promote cooperation and innovation in oncology research, as well as promote the cultivation and exchanges of composite and innovative medical talents in oncology, promote the innovation and development of oncology diagnostic and treatment technology, and improve the survival rate and quality of life of oncology patients. This paper discusses the application of medical-industrial fusion training model in the training of o ncology professionals, and explores the new teaching mode of medical-industrial fusion thinking in the cultivation of complex and innovative medical talents in oncology under the background of "new medical science".

With the deepening of China's medical reform, people's demand for health is growing, which promotes the construction of "new medicine" and puts forward higher requirements for the cultivation and education of medical students. Undergraduate medical education is a crucial period for the growth of medical students, and how to do a good job in undergraduate teaching under the background of "new medicine" is currently a research hotspot. The clinical teaching stage is an important period for medical students to fully understand clinical disciplines and cultivate their understanding of specialties. Therefore, we should explore new teaching methods and means to adapt to the needs of the new era. In the context of "new medicine", the medical-engineering fusion diagnosis and treatment technology has become an important trend in the clinical diagnosis and treatment of oncology. In order to adapt to this change, clinical teaching and teaching management in oncology also need new exploration and research. Taking the clinical teaching of oncology as an example, this article discusses how to cultivate medical students' thinking of medical-engineering fusion.