OBJECTIVEThis study aims to evaluate the effect of ptxA and ptxB genes, which are important genes in the L-ascorbate phosphotransferase system (PTS) of Streptococcus mutans (S. mutans).

METHODSThe ptxA-, ptxB-, and ptxAB-double deficient mutant as well as ptxAB-complemented strain were constructed. Quantitative real-time polymerase chain reaction analysis was performed to evaluate the expression of the target genes of wild-type S. mutans when L-ascorbate was used as the sole carbohydrate source. The OD₆₀₀ values of the wild type, deficient, and complemented strains were continuously monitored, and their growth curves were constructed to compare growth capacity.

RESULTSPolymerase chain reaction and sequencing analyses suggested that deficient and complemented strains were successfully constructed. The expression levelsof ptxA and ptxB significantly increased (P < 0.01) when L-ascorbate was used as the sole carbohydrate source. The growth capacity of the deficient mutants decreased compared with that of the wild-type strain. However, the wild-type phenotype could be restored in the complemented strain.

CONCLUSIONptxA and ptxB genes are associated with L-ascorbate metabolism of S. mutans. The construction of deficient strains and complemented strain lay a foundation for further mechanism study on L-ascorbate metabolism in S. mutans.

Bacterial Proteins ; genetics ; Genes, Bacterial ; Phosphotransferases ; metabolism ; Real-Time Polymerase Chain Reaction ; Streptococcus mutans ; physiology ; Transcription Factors ; genetics

Objective To evaluate the role of miR219‐2‐3p in gastric cancer and the underlying mechanisms .Methods Real time RT‐PCR was employed to quantify the expression level of miR219‐2‐3p in matched tissues of 82 patients .In vitro cell proliferation , the expression of tumorgenesis related protein ERK1/2 was performed by overexpressing miR‐219‐2‐3p in gastric cancer cell line MGC803 .Results The expression level of miR‐219‐2‐3p significantly decreased in late stage gastric cancer (P< 0 .05) .The cell proliferation rate was significantly reduced in gastric cancer cell lines overexpressing miR‐219‐2‐3p .Furthermore ,the expression level of p‐ERK that activated form of ERK was significantly decreased whereas the total level of ERK was unchanged after overex‐pressing of miR‐219‐2‐3p in MGC803 cell lines .The expression level of p‐ERK was also increased in gastric cancer tissues .Conclu‐sion miR‐219‐2‐3p may acts as a tumor suppressor in gastric cancer by decreasing the activity of ERK 1/2 signaling pathway .

Objective To establish a method for high throughput screening single nucleotide polymorphism(SNP) by tag microarray,and then apply the method to study the gene SNP which is related to the motor function of normal people.Methods The genes related to motor function were firstly defined,and then 48 SNP loci were determined.The rs numbers of these SNP loci were fingered out from PubMed,and the primers were designed with the software in web site "www.autoprimer.com".The primer sequences were then downloaded and sent to the biologic corporation for synthesis.After being synthesized and purified by HPLC these primers were used in the experiments according to the instruction of Bakeman's SNPstream machine.The key techniques of SNPstream machine were tag microarray and single nucleotide extension assay.Once the determination was finished,both the gene frequency and allele frequency of every locus could be statistically analyzed.Results The information of the 48 SNP loci that related to motor function had been determined simultaneously by tag microarray,regardless the number of samples to be detected at the same time.The number of the samples was variable to meet the need.The data of gene frequency and allele frequency of these 48 SNP loci may be used in the subsequent studies.Conclusions Tag microarray used to high throughput screening SNP has the advantages of accuracy,speed,efficiency and reasonable cost.Therefore it can be applied to study the relationship between the SNP and many kinds of diseases.

Objective To explore the application value of right heart contrast echocardiography in patients with transient ischemic stroke (TIA) of unknow cause.Methods Totally 120 patients with TIA (TIA group) and 60 cases of normal healthy volunteers (normal group) were enrolled.Two groups underwent right heart contrast echocardiography to observe whether there was a foramen ovale arteriosus (PFO) or not.Diagnostic criteria were left ventricular internal appearing micro bubble≥5 that came from the right atrium to left atrium in three cardiac cycles.Results Small and medium amount of right to left shunt had no significant difference between TIA group and normal group (both P＞0.05),and large amount of right to left shunt had significant difference between the two groups (P＜0.01).Conclusion Contrast echocardiography can effectively diagnose of PFO,and amount of right to left shunt of PFO has relationship with the onset of TIA.

The voltage-gated potassium channels Kvl.5 is widely expressed in the plasma membranes of numerous tumor cells and it can contribute to a variety of cellular functions such as proliferation,ap optosis,and cell cycle.Several types of antineoplastic drugs can change the expression of Kv1.5 and then affect the biological processes.Kv1.5 is identified as a novel target for therapy in human cancer.The researches of Kv1.5 will contribute to gain a further understanding of the molecular mechanism of tumor and provide therapeutic opportunity for the prevention and treatment of cancer.

Objective To investigate the adaptive expression of brush-border disaccharidases in the residual digestive tract of rats following a total small bowel resection. Methods Mucosa was scraped off with a piece of glass from the colon,the cecum and the duodenum of the rats with a total small bowel resection (experimental group,n =10) and normal rats (control group,n =10). Diaccharidase activities were determined in accordance with the method of Dahlqvist. Results Specific activities and total activities of sucrase,maltase in the colon,the cecum and the duodenum in the experimental group were significantly greater than those in the control group( P 0.05). Conclusions Total small bowel resection caused significant adaptive expression of brush-border sucrase and maltase in the residual digestive tract in the rats after a total small bowel resection.

ObjectiveTo discuss the effect of evidence-based nursing in improvement of unhealthy emotion and treatment compliance of patients undergoing painless gastroscopy. Methods134 patients from May 2008 to December 2010 undergoing painless gastroscopy were chosen as study object.According to voluntariness of the patients and their families,they were divided into the evidence-based nursing group (70 cases) and the routine psychological care group (68 cases).The satisfaction degree with nursing,unhealthy emotion,and the compliance during treatment process were evaluated with SAS and SDS.ResultsThe satisfaction degree of patients in the evidence-based nursing group was 92.86％,higher than 79.41％ in the routine psychological care group.No significant difference was shown in SAS and SDS score before treatment between two groups,but unhealthy emotion and treatment compliance after treatment significantly improved,and the improvement degree of the evidence-based nursing group was more evident. ConclusionsApplication of evidence-based care model in painless gastroscopy has more obvious advantages in improvement of unhealthy emotions and treatment compliance compared with routine nursing.It has more important value for clinical practice and is more conducive to improve the quality of life of patients.

Objective:To study the anti-proliferation effects of a heat shock protein 90(Hsp90) inhibitor,17-allylamino-17-demethoxygeldanamycin(17-AAG),on a human breast cancer cell line,SKBr3,and related mechanism.Methods:MTT assay was used to detect the growth inhibition of SKBr3 cells.Cell cycle and apoptosis were analyzed by flow cytometry.Alteration of human epidermal growth factor receptor 2(HER2) in SKBr3 cells being treated with 17-AAG were measured by immunohistochemistry.Results:17-AAG significantly inhibited growth of SKBr3 cells in vitro in a dose-dependent manner with an IC_(50) value at 3.09 ?g/ml.Under concentrations of 0,0.625,1.250,2.500,5.000 and 10.000(?g/ml,)the percentages of cell apoptosis were(1.03?0.08)%,(3.68?0.67)%,(7.06?1.12)%,(11.23?1.36)%,(20.32?1.98)%,and(31.65?2.96)%;the percentages of cells at G_(0)/G_(l) phase were 58.61%,54.34%,49.55%,43.73%,35.52%,and 27.46%;the percentages of cells at S phase were 29.57%,25.21%,19.65%,22.98%,19.71%,and 15.46%;the percentages of cells at G_(2) /M phase were 11.82%,20.45%,30.18%,33.29%,44.77%,and 57.08%,respectively.The level of HER2 expression in SKBr3 cells being treated with 17-AAG,compared to that in control cells,was reduced significantly.Conclusion:17-AAG can inhibit the growth of human breast cancer cell and enhance its apoptosis.It may be a promising anti-tumor drug.

Objective. To observe the effects of closed reduction and pereutaneous K-wires fixation of displacd supracondylar humnerus fracture in children. Methods. Retrospective review of fourteen patients who sustained displaced supmcondylar fracture of distal humerus treated by closed reduction and percutaneous K-wires fixation. Results. All patients' K-wires were removed at 4 weeks post-operation. Their elbow function regained at 8weeks. The average period of followed up was 10 month (varies from 6 to 18 month), all fractmes healed very well without any permanent complications. Two transient nerves palsy, ulnar and radial nerve each, recovered completely at12 weeks and 16 weeks post-operation respectively. Conclusion. Closed reduction and percutaneous K-wires fixation is a safe and efficient treatment for displaced humerus surpracondylar fracture in children.

Objective The aim of this retrospective study was to analyze the role of surgery in the management of limited-stage-Ⅱ small cell lung cancer.Methods A retrospective review of 82 patients with limited-stage Ⅱ small cell lung cancer between January 2001 and December 2009 was performed.The prognostic impact of different therapy and the clinicopathologic factors were analyzed.Using SPSS 16.0 statistical software for data analysis.Log-rank test for the difference of survivale rate.Using the Cox model for muliti-factor survival analysis.Chi-square test for local recurrence and distant metastasis rate.Results The overall median survival time and the 1-,3-,and 5-year overall survival rates were 27.0 months,62.1％,35.9％,and 21.0％,respectively.Median survival was 34.0 months in surgical patients vs 16.0 months in nonsurgical patients (P =0.000).Median survival after lobectomy or pneumonectomy was significantly longer than after wedge resection (P =0.048).However,survival after wedge resection was still significantly longer than survival in nonsurgical patients(P =0.024).Survival analysis confirmed that the operation,chemotherapy and radiotherapy were showed to be independent prognostic factors.The local-regional recurrencer rates of lobectomy or pneumonectomy group was lower than wedge resection group(P =0.030).The distant metastasis rates of lobectomy or pneumonectomy group was lower than nonsurgical grou (P =0.021).Conclusion This study suggests that lobectomy or pneumonectomy combined with adjuvant radio-chemotherapy should be recommended for patients with limited-stage Ⅱ small cell lung cancer.