Objective:To investigate the m echanism of D- amino acid oxidase/D- Alanine system in killing K5 6 2 e cells in vitro.Methods:The killing effects of D- Ala on K5 6 2 e cells stably expressing DAAO and GFP were observed.H2 O2 production by DAAO+ cells were m easured by the phenol red oxidation assay.L owry method was used to determ ine the protein quantities of cells and fluorescent intensities of GFP+ cells were assayed by flow cytom eter.Results:KDf Gd cells were killed completely after treated with 2 5 mm ol/L D- Ala for 2 4 h.The effect of D - Ala at 2 0 m mol/L on KDf Gd cells increased apparently within 4 8h,but the same effect was not observed if D - Ala was below 15 m mol/L .The cytotoxicity of D- Ala in KDf Gd cells was more sensitive than in parental K 5 6 2 e cells.The H2 O2 levels in the medium were consistent with the killing effects of D- Ala.Conclusion:The killing effects of DAAO/D- Ala system is m ediated by H2 O2 . [

Objective To obtain different biomechanical conditions of the tibia section with different osteotomy thickness under different activity states,so as to provide theoretical basis for total knee arthroplasty (TKA) and patient activities after operation.Methods The three-dimensional models of lower limb were reconstructed and the proximal tibia was resect by 0 mm,5 mm,7 mm,9 mm,respectively,based on the principle of bone resection in TKA.The tibia models after osteotomy were assigned with the material properties,and the stress and strain of the tibia cross-section were then analyzed under the following activity states:standing,walking,running and climbing upstairs.Results The stress and displacement of the tibia cross-section increased with the increase of osteotomy thickness under the same activity state.The maximum stress and displacement of tibia cross-section with the same osteotomy thickness showed an increasing trend when the strength of activity increased.Conclusions For TKA in clinic,the stress and strain on tibia cross-section become larger with the thicker tibia osteotomy and the stronger postoperative activity.Excessive osteotomy in TKA and activity too intensively after TKA should be avoided,so as to reduce stress and strain of the tibia plateau and promote long-term life of the prosthesis.

Avian trichomoniasis caused by Trichomonas gallinae is a serious protozoan disease worldwide. The domestic pigeon (Columba livia domestica) is the main host for T. gallinae and plays an important role in the spread of the disease. Based on the internal transcribed spacers of nuclear ribosomal DNA of this parasite, a pair of primers (TgF2/TgR2) was designed and used to develop a PCR assay for the diagnosis of T. gallinae infection in domestic pigeons. This approach allowed the identification of T. gallinae, and no amplicons were produced when using DNA from other common avian pathogens. The minimum amount of DNA detectable by the specific PCR assay developed in this study was 15 pg. Clinical samples from Guangzhou, China, were examined using this PCR assay and a standard microscopy method, and their molecular characteristics were determined by phylogenetic analysis. All of the T. gallinae-positive samples detected by microscopic examination were also detected as positive by the PCR assay. Most of the samples identified as negative by microscopic examination were detected as T. gallinae positive by the PCR assay and were confirmed by sequencing. The positive samples of T. gallinae collected from Guangzhou, China, were identified as T. gallinae genotype B by sequencing and phylogenetic analyses, providing relevant data for studying the ecology and population genetic structures of trichomonads and for the prevention and control of the diseases they cause.
China* ; Columbidae* ; Diagnosis ; DNA ; DNA, Ribosomal ; Ecology ; Genetic Structures ; Genotype ; Methods ; Microscopy ; Parasites ; Polymerase Chain Reaction* ; Trichomonas*

OBJECTIVETo study the academic level of randomized controlled trials (RCT) published in the Chinese Journal of Gastrointestinal Surgery between 2003 and 2009.

METHODSPublished RCTs in the 42 issues of the Chinese Journal of Gastrointestinal Surgery was searched for relevant articles published between 2003 and 2009. Data extracted for analysis included the time at manuscript received, publication time, total number of citations, number of citations in Chinese, number of citations in English, author's affiliations, single- or multi- center study, positive conclusions from RCTs, number of patients recruited in RCTs, research funding source, the start time, the finish time and the number of authors in RCTs.

RESULTSDuring the past seven years, a total of 80 clinical RCTs were published in the Chinese Journal of Gastrointestinal Surgery, accounting for 12% of all the clinical studies published in the journal, and the average number of RCTs in each issue was 1.6. The average delay time before publication was 208 days. The total number of citations and the total number of patients in RCTs were 685 and 9402. The average number of citations, the average number of patients recruited in each RCT, and the average research period in RCTs were 8.6, 118 and 29.2. There were 7 multi-center studies, and the number of single-center study was 73. All the RCT studies had significant conclusions, and 17 (21.3%) RCT studies were funded. Nanjing general hospital of Nanjing military command had the largest number of RCTs (n=6).

CONCLUSIONThe Chinese Journal of Gastrointestinal Surgery puts emphasis on clinical studies of high evidence level such as RCT, which provide evidence for making the clinical guidelines in the specialty of gastrointestinal surgery.

OBJECTIVETo study the effect of cordycepin on cell cycle, apoptosis and autophagy of human tongue cancer TCA-8113 cells and explore the mechanism of cordycepin for inhibiting the occurrence of tongue cancer.

METHODSCCK-8 method was used to assess the inhibitory effect of cordycepin on TCA-8113 cell proliferation in vitro. The cell cycle and cell apoptosis of TCA-8113 cells treated with different concentrations of cordycepin were analyzed using flow cytometry. The expressions of apoptosis-related genes caspase-3, caspase-9, Bcl-2, and Bax were examined using quantitative real-time PCR and Western blotting, and immunohistochemistry was used to detect the expressions of autophagy-related proteins LC-3β, P62, p-mTOR, and AMPK.

RESULTSCCK-8 assay showed that cordycepin significantly inhibited the proliferation of TCA-8113 cells in a concentration-dependent manner with an IC of 3.548 mg/mL at 24 h and an IC of 1.185 mg/mL at 48 h. Flow cytometric analysis showed that cordycepin caused cell cycle arrest at S phase and dose-dependently increased the apoptotic rate of TCA-8113 cells. Treatment of the cells with cordycepin enhanced the expressions of Bax, caspase-3 and caspase-9 at both the mRNA and protein levels and inhibited the expression of the antiapoptotic gene Bcl-2. Immunohistochemistry demonstrated that cordycepin promoted the expression of LC-3β and AMPK and inhibited the expression of P62 and p-mTOR.

CONCLUSIONCordycepin inhibits the proliferation and induces apoptosis of HCT-116 cells through the mitochondrial pathway and induces autophagy via the AMPK/mTOR pathway.

Objective To explore the appropriate ways and contents of reproductive health education for middle school students and to understand reproductive health related sexual behavior and influencing factors among middle school students. Methods Reproductive health related sexual behavior was evaluated among junior and senior middle school students in Luoyang by cluster sampling. The statistical software of SAS 8.1 was adopted for data analyses. Sexual behavior and influencing factors were analyzed by logistic regression. Results Critical sexual behaviors were found significantly higher in senior students,including masturbation, sexual fantasy and sexual intercourse than that in junior students (P<0.05), and boys had higher prevalence than girls (P<0.05). Results from multivariate logistic regression model analyses indicated that incidence rate of sexual behavior among those who ever having had experiences was higher than those who were inexperienced ( OR = 2.62,95 % CI:1.21-5.66). Incidence rate of sexual behavior was related to access of reproductive health and STD/AIDS knowledge ( OR = 3.09,95 % CI:1.43-6.51). In addition, incidence rate of sexual behavior was related to attitude and relation of amour between boys and girls ( OR = 2.24,95 % CI:1.32-3.75). Conclusion Awareness on reproductive health knowledge among middle school students was not enough. Marginal sexual behaviors as masturbation and sexual fantasy had not been correctly and openly discussed to avoid inappropriate sexual activities.

Objective To obtain biomechanical conditions of the tibia section with different osteotomy thickness under different activity states, so as to provide theoretical basis for osteotomy thickness in total knee arthroplasty (TKA) and activities of patients after operation. Methods The three-dimensional models of the lower limb were reconstructed and the proximal tibia was resected by 0 mm,5 mm,7 mm,9 mm respectively based on the principle of bone resection in TKA. The tibia model after osteotomy were assigned the material properties and the stress and strain of the tibia cross-section were analyzed under the following activity states: standing, walking, running and going upstairs. Results The stress and displacement of the tibia cross-section increased with the increase in osteotomy thickness under the same activity state. The maximum stress and displacement of tibia cross-section increased in general with the same osteotomy thickness, when the strength of activity increased. Conclusions During TKA in clinic, the stress and strain on tibia cross-section became larger as the tibia osteotomy became thicker and the postoperative activity became stronger. Excessive osteotomy in TKA and high intensive activity after TKA should be avoided, so as to reduce stress and strain of the tibia plateau and promote long-term life of the prosthesis.