BACKGROUND: There are different methods to isolate and culture human nucleus pulposus cells, and the differences in digestive enzymes components and digestion time quite are significant. So how to rapidly and efficiently harvest human nucleus pulposus cells has become a research hotspot. OBJECTIVE: To optimize the digestive enzymes components and digestion methods for the preparation of human nucleus pulposus cells. METHODS: Nucleus pulposus tissue specimens were selected from three adult discs in the Department of Orthopedics, China-Japan Union Hospital of Jilin University. The acute traumatic disc tissues that outstanding to the spinal canal were taken under aseptic conditions, and then the peripheral white annulus and jel y-like nucleus pulposus in the center could be seen. According to different mixed enzyme concentration ratio, the samples were divided into two groups. The enzyme Ⅰ group was treated with 0.2% Ⅱ col agenase; and the mixed enzymeⅡ group was digested with 0.25% trypsin for 30 minutes, and then treated with 0.2% Ⅱ col agenase. According to digestion time, each group was divided into three subgroups: 2 hours group, 4 hours group, and overnight group. Final y, suspended cel volume was decided as 2 mL to count cells. Dulbecco’s modified Eagle’s medium containing fetal bovine serum was used for cel culture in vitro. Trypan blue staining was performed to count total cel number and ratio of living cells. Methylthiazolyldiphenyl-tetrazolium bromide assay was used to detect the growth curve of nucleus pulposus cells. RESULTS AND CONCLUSION: Based on the two digestion enzyme concentration, the number of digested cells in the enzyme Ⅰ group was larger than that in the enzyme Ⅱ group after digested for 2 and 4 hours, but the difference was not significant (P > 0.05). Overnight, cellsurvival rate was decreased in the enzyme Ⅰ group after digested for 2 and 4 hours when compared with the enzyme Ⅱ group, and the difference was significant (P < 0.05). After digested for 4 hours, tissue blocks disappeared, and the number of cells reached maximum. The results indicate that enzyme Ⅰgroup composite with Ⅱ col agenase is benefit for the separation of nucleus pulposus cells, and the digestion time is appropriate to 4 hours. This condition has the advantages of simple operation, high efficiency and low cost, and it considered that digestion of nucleus pulposus tissues with 0.2% Ⅱ col agenase for 4 hours is the best condition to obtain nucleus pulposus cells.

BACKGROUND:Advancement in bioengineering based upon tissue engineering techniques may offer the possibility of repairing degenerative intervertebral disc.
OBJECTIVE:To summarize the research progress in the scaffolds of tissue engineered intervertebral disc.
METHODS:A computer-based retrieval was performed to search manuscripts describing tissue engineered intervertebral disc scaffolds published between January 1st, 1900 and December 31st, 2012 in PubMed database with the key words of“tissue engineering, intervertebral disc, scaffold”in English.
RESULTS AND CONCLUSION:Scaffold is an important part of tissue-engineered research. There are three kinds of materials for intervertebral disc scaffolds:natural biomaterials, synthetic materials, and composite materials. A variety of scaffold materials have their own advantages and disadvantages. Up to now, none of these scaffold materials is accepted as the most suitable one. The selection of scaffold materials is stil to be further studied. The study and development of nanoscale biomaterials is an inevitable trend. Otherwise, with the help of bionics, improving scaffolds is also an inexorable trend in progress of simulating human intervertebral disc. Furthermore, injectable scaffold is also an research hot spot, and the selection range of injectable scaffold materials mainly focuses on chitosan, typeⅡcolagen,hyaluronic acid,fibrin,elastin,and alginate.C urrently, studies on chitosan as a scaffold material are relatively more.

Objective To evaluate HBeAg quantification in predicting the efficacy of pegylated interferon (PegIFN) α treatment for patients with HBeAg-positive chronic hepatitis B (CHB).Methods A total of 216 HBeAg-positive CHB patients admitted in Ningbo No.2 Hospital during March 2009 and December 2011 were enrolled in the study.All patients were given subcutaneous injection of PegIFNα-2a or PegIFNα-2b weekly for 48 weeks and followed up for 24 weeks after discontinuation.Patients were divided into HBeAg seroconversion group and non-seroconversion group at the end of the follow-up.Receiver operating characteristic (ROC) curves were used to evaluate HBeAg levels at baseline and 12,24 weeks of treatment in predicting HBeAg seroconversion.Results HBeAg seroconversion was observed in 31.48％ (68/216) patients at the end of follow-up,and there was no significant difference in seroconversion rate between patients treated with PegIFNα-2a and those with PegIFNα-2b (32.00％ vs.29.27％,P ＞ 0.05).There was significant difference in baseline HBeAg levels between patients with HBeAg seroconversion and those without HBeAg seroconversion (Z =-3.834,P ＜ 0.05).HBeAg seroconversion patients had a tendency of rapidly decreasing HBeAg level,but there was no significant difference in decreasing rate between seroconversion and non-seroconversion patients (F =3.321,P ＞ 0.05).ROC curves showed that HBeAg level at 24-week was the best indicator for predicting HBeAg seroconversion with area under curve of 0.861.Conclusion Serum HBeAg level at 24-week of treatment may be used to predict the HBeAg seroconversion in HBeAg-positive CHB patients treated with PegIFNα.

Objective To investigate the efficacy of polyethylene glycol (PEG)-interferon α (PEG-IFNα) in treating HBeAg-positive chronic hepatitis B (CHB) and explore the relationship between hepatitis B virus (HBV) genotypes and the effect of interferon α (IFNα) therapy.Methods A total of 199 CHB patients with known genotypes were given subcutaneous injection of PEG-IFNα-2a or PEG-IFNαt-2b once a week for 48 weeks,with another 24 weeks follow up.The seroconversion of HBeAg influenced by HBV genotypes were analyzed after discontinuation of treatment.Results In local area,genotype C was the major genotype[64.32％ (128/199)].Except serum ALT and AST level,the differences in gender,age,liver inflammation,degree of liver fibrosis,HBeAg level and HBV DNA level between genotype B and C were not statistically significant(all P ＞0.05).The seroconversion rate of HBeAg in patients with genotype B at early stage of therapy (3 months) was significantly higher than that of patients with genotype C [26.76％ (19/71) vs 10.16％ (13/128),x2 =9.330,P =0.002].While at the end of follow-up,seroconversion rate of HBeAg in patients with genotype B (followed up for 6 months) was higher than that of patients with genotype C [39.44％ (28/71) vs 30.47％ (39/128)],but the difference was not statistically significant(x2 =1.645,P =0.200).By univariate analysis based on log-rank test,the time of HBeAg seroconversion in patients with genotype B was much earlier than that of genotype C [(13.99 ± 0.67) months vs (15.47 ± 0.41)months],but the difference was not statistically significant (P =0.150).Conclusions The seroconversion rate of HBeAg in patients with genotype B treated with PEG-IFNα was significantly higher than that of genotype C in early stage of therapy (3 months),while similar at the end of therapy.

The application of cerebrovascular intervention brings the diagnosis and treatment of cerebrovascular disease into a brand-new domain. Many neurological physicians have become physicians of cerebrovascular intervention by training. In the big teaching hospitals carrying out cerebrovascular intervention, advanced physicians are the hard strength in the lot of cerebrovascular intervention. The training aiming at cerebrovascular intervention and comprehensive abilities affects both the training results and the therapeutic results of cerebrovascular intervention. Therefore, it is an important issue to explore how to consummate and standard the training methods of advanced physicians studying cerebrovascular intervention.

AIM: To study the relationship between prostaglandins and acute pulpitis. METHODS: Rat traumatic pulpitis model was established by pulp exposure. The kinetic pathological changes in dental pulpal tissues and changes of PGE 2?6-Keto-PGF 1? and TXB 2 concentration in dental pulp were observed. RESULTS: After pulpal trauma, the dental pulp showed inflammatory changes and the concentrations of PGE 2?6-Keto-PGF 1? and TXB 2 were increased, which peaked at 6 hour post-trauma. CONCLUSION: Prostaglandins play a significant role in the pathogenesis of pulpitis.

Nitric oxide (NO) is an intra- and intercellular messenger with a broad spectrum of activities in the central nervous system, cardiovascular and immune systems. Mitochondrial nitric oxide synthase(mtNOS), which might be a new form of NOS in mitochondria, has been discovered to be active in the regulation of mitochondrial respiration, energy metabolism and many pathophysiological processes. In this review, the location, properties, physiological and pathophysiological significance of mtNOS were summarized.

Objective To investigate the short-term clinical efficacy of radioactive125I seed implantation in the treatment of patients with thymoma recurrence. Methods Clinical data of patients with thymoma, who underwent radioactive125I seed implantation in Huadong Hospital of Fudan University during Sep. 2016 and Jun. 2017, were retrospectively collected. Inclusion criteria: local pleural recurrence lesions; intolerable to systemic chemotherapy or failure in previous chemotherapy; previously received high-dose chest radiotherapy; and normal coagulation function. All the patients were examined by computed tomography (CT), ultrasound and positron emission tomography-computed tomography (PET-CT) before operation. According to the Radiotherapy Planning System (TPS), the patients were inserted with the particle needles at the puncture point under the guidance of CT or ultrasound, and the distance between the sources was generally 0.5 cm. The clinical efficacy and adverse reactions were observed at 2 months after treatment. The patients were followed up for 3-9 months. Results A total of 13 patients underwent radioactive125I seed implantation, aged from 30 to 78 years, with 7 males and 6 females. The median number of implanted particles was 30, ranging from 20 to 58; the median dose of the particles was 1.9×107 Bq, and the range was (1.5-2.6)×107 Bq. The objective response rate was 100% (7 cases in complete remission and 6 in partial remission) after 2 months of follow-up, and all the 4 patients with chest wall pain were relieved. Pneumothorax occurred in 1 patient during particle implantation. During 3 to 9 months of follow-up, no patient developed disease progression at the site of particle implantation. Conclusion Radioactive125I seed implantation is a safe and effective method in the treatment of pleural recurrence of patients with thymoma, and can be used as a salvage therapy after the failure of traditional radiotherapy and chemotherapy, but its long-term effect needs further observation.

Objective To investigate genotypes and antimicrobial susceptibility of Rhizobium radiobacter (R.radiobact-er)isolated from pediatric patients with bacteremia.Methods R.radiobacter strains from blood cultures of pediatric pa-tients with bacteremia from February 2013 through February 2014 were collected.16S rDNA fragment was amplified by polymerase chain reaction(PCR),bacterial genotypes were identified by pulsed-field gel electrophoresis (PFGE),antimi-crobial susceptibility testing were performed by Kirby-Bauer disk diffusion method.Results 13 isolates of R.radiobacter were isolated from 12 children with positive blood culture,which including 3 genotypes,the homology of 16S rDNA fragment and R.radiobacter IFM 10623 was up to 99%.According to CLSI 2003 standard,these 13 R.radiobacter were resistant to ceftazidime,piperacillin,ticarcillin,piperacillin/tazobactam,ticarcillin/clavulanic acid,aztreo-nam and polymyxin B,but sensitive to cefepime,doripenem,imipenem,meropenem,tobramycin,netilmicin,cip-rofloxacin,levofloxacin,and norfloxacin.In addition,cefotaxime and ceftriaxone showed larger inhibition zone. Conclusion Therapy of R.radiobacter infection should be based on antimicrobial susceptibility testing results;cefo-taxime and ceftriaxone are better selection for the therapy of R.radiobacter infection in pediatric patients.

Objective To assess the liver biopsy and the clinical characteristics of inactive HBsAg carriers.Methods One hundred and ten inactive HBsAg carriers,including 76 males and 34 females aged (38.9 ± 9.4) years (21-66),underwent liver biopsy from January 2011 to September 2015,the histopathological findings and clinical features were analyzed.Among 110 cases the inflammation activity (A) was ＜ A2 in 73 cases and ≥A2 in 37 cases;the fibrosis (F) ＜ F2 in 63 cases and ≥F2 in 47 cases.The upper limits of normal (ULN) for ALT was defined as 30 U/L for men and 19 U/L for women according to World Health Organization (WHO) standard,and 50 U/L for men and 40 U/L for women according to Chinese national standard.There were 59 cases with ALT ＜ 1 × ULN of WHO standard and 110 cases with ALT ＜ 1 × ULN of Chinese standard.Results In 110 inactive HBsAg carriers,there were 100 cases (90.9％) ≥A1 and 37 cases (33.6％) ≥A2,84 cases (76.3％) ≥F1 and 47 cases (42.7％) ≥F2.The severity of A and F were both higher in males than that in females,especially that of F (U =2.162,P =0.032;x2 =5.315,P =0.021).But there were no statistical differences between WHO standard group and Chinese standard group (U =0.951,0.435;P =0.341,0.663).Along with the increase of age,the degrees of A and F aggravated (F =3.705,5.915;P =0.014,0.001).The average ages in ≥ A2 group and ≥F2 group were (41.7 ± 9.6) years and (38.7 ± 8.1) years,respectively.The independent risk factors for severity of A and F were age,gender (male) and age,respectively.Conclusion There may be histological damages of varying degree in liver tissues of most inactive HBsAg carriers,and for those aged 40 years and over,especially males screening of liver histological activity and fibrosis would be necessary.