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

ObjectiveTo observe the effects of electroacupuncture on IL-1β in brain tissue of rats after total cerebral ischemia-reperfusion.MethodsThirty male Wistar rats were randomly divided into the sham operation group, model group and acupuncture group, in each group. In acupuncture group and model group, 4-vessel-occlusion method was used to make a rat model of cerebral ischemia reperfusion. Acupuncture group used electroacupuncture on points Quchi and Zusanli, 6 hours after reperfusion. The rats of each group were killed and ELISA was used for the measurement of IL-1β in brain tissues.ResultsIL-1β in brain tissue in model group increased significantly compared with sham operation group and acupuncture group(P<0-001). No significant differences were found between sham operation group and acupuncture group (P>0-05).ConclusionAcupuncture can lower IL-1β content of brain tissue of rats with brain ischemia/reperfusion injury.

Objective:To evaluate the preventive effect of proximal splenic vein ligation after splenectomy on the splenic vein originated portal vein thrombosis (PVT) in portal hypertension.Methods:The clinical data of 94 patients of portal hypertension who had received splenectomy were retrospectively analysed. The proximal splenic vein was ligated in 36 cases during pericardial devascularization and coronary renal shunt with splenectomy. The other 58 cases who had received pericardial devascularization without proximal splenic vein ligation served as control. All of the patients in both groups were given heparin infusion postoperatively through the catheter which was placed in the right gastroepiploic vein during operation. CT portal veinography was performed at the 7th-14th postoperative day for detection of PVT.Results:None of the PVT occurred in the splenic vein ligation group. In the control group, PVT occurred in 22 cases(38%) and splenic vein thrombosis occurred in all the 58 cases (100%). PVT incidence between the two groups is significantly different (0 vs. 38%, χ 2=17.828, P<0.05). Conclusions:Ligation of the proximal splenic vein during splenectomy can effectively prevent the postoperative splenic vein originated PVT in portal hypertension.

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 explore the influence of electrical stimulation on prefrontal cortical neurons and synaptic ultramicrostructure of hypoxic-ischemic brain damage(HIBD)in neonatal rats.Methods The sixty 7-day-old newborn healthy SD rats were randomly divided into hypoxic-ischemic group(model group),electrical stimulation(intervention)group and sham operation group(control group),which 20 for each group.The models of perinatal HIBD rats were prepared by ligation of left common carotid artery with a temporary systemic hypoxia for 2 hours.Intervention group was subject to electric stimulation for 30 minutes,once everyday after surgery.Control group and model group were not subject to electric stimulation but caught to fix in corresponding period.Fastigial nucleus electric stimulations were performed for 3 d,14 d and 21 d.Five rats were killed in each group after the application of electron microscope to observe the brain cortex neurons and synaptic ultrastructure changes.Results In model group,the neuronal shrinkage,the amount of organelles dacrease,ob-vious edema of cytoplasm,obvious swellen mitochondria,and synapse quantity decrease,synaptic space fusion,obvious synaptic vesicle were observed.Intervention group different times,mitochondria hydrops gradually alleviated,synaptic space gradually cleared,synaptic vesicle increased,pathological changes obviously lessened compared to model group at the same time,and there was no apparent abnormality compared with control group on the 21st d.Conclusion Electric stimulation can promote the ultramicrostructures recovery of HIBD rats.

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.