In plant genetic engineering, selectable marker is needed to distinguish transformant. As the commercialization of transgenic plants, people are more and more paying close attention to their safety, among which mainly refers to the safety of selectable marker. In order to increase the safety of transgenic plants, biologists began to search for biosafe selectable marker.Current research progress of taking key enzyme in metabolic pathways were overviewed,which include glycometabolism, amino acid metabolism, hormone metabolism ,nucleotide metabolism and protein metabolism et cetera, as selectable marker in transgenic plants.

The rodipicolinate synthase gene was cloned from Nicotiana tabacum L.cv,which encodes the key enzyme in the synthesis of lysine,and then a vitro molecular reform reliefing feedback suppression was made. Some resistant seedlings were acquired using the mutated gene as selectable marker and analog of lysine as selectable reagent,and the detection results were positive by means of PCR and Real-Time PCR,however the phenotype is somewhat abnormal.

Malignant biliary tract obstruction is a common disease.Nowadays,endoscopic biliary drainage (EBD) and percutaneous transhepatic biliary drainage (PTBD) have been used to treat such disease.EBD is a first-line intervention for lower segment of biliary duct obstruction caused by pancreatic cancer or other tumors.PTBD is a first-line treatment for gallbladder cancer or other tumors which lead to the hilar and intrahepatic bile duct obstruction and abnormal digestive anatomy.In a word,the proper selection of the drainage should be based on the patients' condition with minimal trauma and maximum therapeutic effect.

Heart ; drug effects ; Heart Failure ; drug therapy ; Humans ; Hydrogen Bonding ; Nitrogen Oxides ; pharmacology ; therapeutic use

AIM:To put forward three-level design(Box-Behnken design)for fitting response surfaces to optimize the extraction technology of total flavonoids from Hypericum ascyron L.METHODS:Four factors,including temperature,reflux time,concentration of ethanol,ratio of solvent to raw material were used to examine the yield of total flavonoids.Prediction was carried out through comparing the observed and predicted values.RESULTS:The results suggested that ethanol concentration and extraction temperature were two statistically significant factors.The optimum conditions of extraction process consisted of the ratio(mL:g)of solvent to material(13.3:1),ethanol concentration(53.2%),extraction temperature(78.7℃)and extraction time(2.3h).Regression coefficient of binomial fitting complex model was as high as 0.984 6.Bias between observed and predicted values was-4.01%.CONCLUSION:Box-Behnken design is success in optimizing the extaction in close agreement with the predicted values of the mathematic model.

Objective To investigate the effects of electrical stimulation on vascular endothelial growth factor(VEGF) and its receptor expressions of neonatal rat brain with hypoxic-ischemic brain damage(HIBD).Methods Seventy-five 7-day-old newborn health SD rats were randomly divided into sham operation group(control group,n=25),hypoxia-ischemia group(model group,n=25) and the electrical sti-mulation group(intervention group,n=25).To bulid HIBD animal model of neonatal rats,the left common carotid artery was ligated and nitrogen-oxygen gas mixture was inhaled 2 hours.Fastigial nucleus stimulation was given 12 hours after the operation in intervention group,30 min?time-1,1 time?d-1,the time length was 1 d,3 d,7 d,14 d or 21 d,respectively.There was no electrical stimulation in model group and control group.The rats in these groups were captured at the corresponding time.Five rats in each group were killed at the corresponding pe-riods after electrical stimulation,the expression of VEGF and its receptor fam-like tyrosine kinase receptor(flt-1 / VEGFR1),fetal liver kinase receptor(flk-1/KDR/VEGFR2) in hippocampus were observed by immunohistochemistry.SPSS 15.0 software was used to analyze the data.Results The expression of VEGF,VEGFR1,VEGFR2 at every time point in electrical stimulation group were higher significantly than those in model group and control group(Pa0.05).Conclusion Electrical stimulation can promote the expression of VEGF and its receptors VEGFR1,VEGFR2.

Objective To compare the cardiac function parameters in gated SPECT determined by filtered back projection (FBP) and OSEM reconstruction methods. Methods One hundred and forty-four patients underwent 99Tcm-MIBI gated-SPECT imaging studies. The parameters LVEF, EDV and ESV, were derived using quantitative gated SPECT (QGS), four-dimensional model SPECT (4D-MSPECT) and emory cardiac toolbox (ECToolbox) softwares. Each image was reconstructed by FBP or OSEM. Bland-Altman analysis and paired t-test were applied to evaluate those parameters. Results Correlation coefficients for LVEF, EDV and ESV between FBP and OSEM methods were all more than 0.93 (all P<0.001). EDV calculated by FBP was lower than that by OSEM using QGS software, but became the opposite when using 4D-MSPECT and ECToolbox softwares. (QGS: (82.2±39.1) ml vs (83.5±40.8) ml, t=-2.53, P<0.05; 4D-MSPECT: (93.5±46.9) ml vs (88.8±45.2) ml, t=5.95, P<0.01; ECToolbox: (106.4±51.1) ml vs (100.8±49.0) ml, t=3.99, P<0.01). ESV calculated by FBP was higher than that by OSEM using 4D-MSPECT software (4D-MSPECT:(37.5±41.4) ml vs (34.8±37.6) ml, t=3.92, P<0.01). LVEF calculated by FBP was lower than that by OSEM using QGS software ((62.1±16.9)% vs (63.1±16.1)%, t=-3.14, P<0.05), but higher than that by OSEM using ECToolbox software ((74.1±18.8)% vs (71.3±17.1)%, t=5.28, P<0.01). Conclusion Generally, cardiac functional parameters based on FBP and OSEM construction methods correlated well, although they might have singnificantly different results.

Objective To discuss the role of miRNA-374a in invasion and metastasis of breast cancer.Methods Breast tissues from 48 patients(32 patients with breast cancer)were classified into high invasive and metastatic group(HIMG,group A),low invasive and metastatic group(LIMG,group B),and normal group (group C).Each group contained 16 specimens.6 samples were selected randomly from each group and were detected by microRNA array.Key microRNA (miRNA-374a)was selected and its target protein(BMP-2) was predicted by bioinformatics software.The rest 10 specimens of each group were detected by real-time qRT-PCR and Western blot to test the content of miRNA-374a,mRNA and protein of BMP-2.Correlation analysis was performed between miRNA and the target protein.SPSS 18.0 was used to make statistical analysis.Results The relative content of miRNA-374a was higher in group C than in group B,higher in group B than in group A(P ＜ 0.05).BMP-2 mRNA level was higher in group A and group B than in group C (P ＜ 0.05).The expression level of BMP-2 protein was lower in group C than in group B,lower in group B than in group A(P ＜0.05).Correlation analysis showed that miRNA-374a was negatively correlated with BMP-2 protein(P =-0.412 8).Conclusion miRNA-374a inhibits the invasion and metastasis by regulating BMP-2 in human breast cancer.

Objective:To develop the instrument for the evaluation of the report quality of clinical trials with the modified Delphi method in combination with panel discussions, and assess its validity and reliability. Method: For the development of the instrument, the modified Delphi method in combination with a panel discussion was applied. The consulting panel included pharmacologists, clinical doctors, epidemiologists, statisticians and editors of journal. 30 reports for the therapy of hypertension published in 2000 were selected for the estimation of the instrument of the validity and reliability. The interclass correlation coefficient (ICC) was used to test the reliability. The CONSORT statement was used as a control, and a Kendall correlation was worked out to estimate the validity. Result:A total of 10 specialists took part in the consultation. During the first round of consultation, the expert harmonious coefficient (W) reached to 0. 505 and 19 items were identified. A total of 100 scores were distributed to the 19 items in the second round, and finally the scale was completed. After scoring the 30 reports on hypertension therapy by two readers independently, the interclass correlation coefficients (ICC) of the total score were 0.921,and 0.987 in the introduction part, 0.875 in materials and methods, 0.902 in results, and 0.966 in the discussion and others, P