Psychostimulant is a type of psychoactive substances that stimulate central and peripheral nervous system as well as induce drug dependence.A series of studies indicate that monoamine especially dopamine plays an important role in behavior and drug dependence,moreover,dopamine transporter(DAT)controls homeostasis of dopamine in neuron and transmission of dopamine pathways.Thus DAT might play an important role in the reward and behavioral stimulation of psychostimulant.

Objective:To compare the effect of Rain Classroom and traditional teaching model on the academic achievement of domestic medical undergraduates by Meta-analysis.Methods:All literature were retrieved from CNKI, Wanfang Med Online, VIP, and CBM databases, and the retrieval time limited from the establishment of the database to October 2019. Randomized controlled trials (RTCs) for the evaluation of the effects of Rain Classroom method in undergraduate medical education were selected. Literature were screened according to the established inclusion and exclusion criteria. Data was extracted and the quality of the literature was assessed using the Jadad scale. All analyses were performed by Stata 12.0 software.Results:A total of 3 662 medical undergraduates in 20 RCTs were included. Meta-analysis results showed that student's theoretical and practical scores of the Rain Classroom teaching group were significantly higher than those of the traditional teaching group (theoretical scores: WMD = 8.52, 95%CI = 7.30 -9.74, P < 0.001; practical scores: WMD = 8.95, 95%CI = 5.42 -12.49, P < 0.001). Conclusion:The Rain Classroom teaching method can effectively improve the theoretical and practical academic achievement among medical undergraduates and enhance the teaching effect. This study has also provided the evidence -based basis for the promotion and application of the Rain Classroom teaching method in medical undergraduate courses.

Objective To construct the expression box of fusion gene NT4-p53(N15)-Ant.Methods The gene of p53(N15)-Ant was obtained by PCR of two primers templating with each other and T-vector cloning method.The positive clone was identified and analyzed by the restriction enzymes and sequencing respectively.After digested with restriction enzyme,the interest gene of p53(N15)-Ant was subcloned into the plasmid pBV220/NT4.Results The gene of p53(N15)-Ant was confirmed by the digestion of restriction enzyme and sequencing.The recombinant plasmid pBV220/NT4p53(N15)Ant was identified by the digestion of restriction enzyme and agarose gel electrophoresis and the results conformed theoretical values.Conclusion The plasmid pBV220 containing the expression box of NT4-p53(N15)-Ant was successfully constructed by molecular cloning and recombination techniques in vitro,which will guide further study on gene therapy of cancer.

Objective To construct and expr es s a recombinant plasmid of nonstructural protein NS3-NS4 of hepatitis C virus ( HCV), and to identify the antigenicity of the expressed protein. Methods A gene region encompassing the nonstructural protei n NS3-NS4 of HCV was amplified by polymerase chain reaction (PCR) from the pUC1 9/HCV template. The recombinant expression plasmid containing the pBV220/NS3-NS 4 sequence was constructed, and the nonfused NS3-NS4 recombinant protein was ex pressed in E.coli DH5? efficiently. The recombinant protein was det ected by SDS-PAGE and ELISA. Results We successfully constructed and expressed the recom binant plasmid in prokaryote. Its antigenicity was detected with 50 standard ser a. Compared with the second-generation diagnostic Kit, the total detection rate was 96%. Conclusion The whole NS3-NS4 protein, a region of dominant immunogenicity, should be the effective component of the HCV diagnostic Kit and provide the clue for developing HCV DNA vaccine.

Objective:To construct a recombinant adenovirus vector harboring fusion gene NT4-p53(N15)-Ant,laying a foundation for gene therapy research of malignant tumors.Methods:The p53(N15)-Ant gene was obtained by T-vector method and was inserted in pBV220/NT4 vector after digested with restriction enzyme.The fusion gene of NT4-p53(N15)-Ant was subcloned into the shuttle plasmid of adenovirus;the products were cotransfered into HEK-293 cell line with helper plasmid PJM17.The recombinant adenovirus was produced by homologous recombination of above 2 plasmids in HEK-293 cells and its titer was measured by plaque-forming.The expression of Ad.NT4p53Ant in transfected 293 cells was confirmed by reverse transcription polymerase chain reaction(RT-PCR)procedure.The effect of Ad.NT4p53Ant on HepG2 cell line was measured by a colorimetric 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide(MTT)assay.Results:The p53(N15)-Ant gene was confirmed by restriction enzyme digestion and DNA sequencing.High titer of recombinant adenovirus was obtained by homologous recombination in HEK-293 cells(1?10 11pfu/ml).The expression of NT4-p53(N15)-Ant gene in 293 cells was confirmed by RT-PCR.Ad.NT4p53Ant had strong killing effect on HepG2 cells.Compared with Ad.GFP,Ad.NT4p53Ant significantly decreased the survival rate of HepG2 cells.Conclusion:The recombinant adenovirus vector encoding gene NT4-p53(N15)-Ant has been successfully constructed in this experiment by molecular cloning and in vitro recombination techniques,laying a foundation for further research of gene therapy of cancer.

ObjectiveLoss-of-function mutation of p53,a tumor suppressor gene,is an important mechanism for the development of human cancers.In this study we tried to transfect p53N15-based fusion peptide into H1299,a lung cancer cell line,and evaluate the anti-tumor effects of the fusion peptide.MethodsAdeno-associated virus ( AAV) vectors were used for transfecting p53N15 fusion peptide into p53-null lung adenocarcinoma H1299 cells.The anti-replication effects of p53N15 fusion peptide were evaluated with inverted microscopy,MTT test for cell viability and flow cytometry.ResultsFusion peptides in H1299 cells was highly expressed and had detectable suppressive effects on cell proliferation.A large amount of dead cells were seen under microscope after the transfection of recombinant viruses for 72 hours.Cells activity was reduced significantly in the virus-transfecting groups as demonstrated by MTT test.The flow cytometry showed that a large number of dead cells were present in the virus-transfecting groups.ConclusionThe growth of H1299 lung adenocarcinoma cells could be inhibited in vitro by being transfected with p53N15 fusion peptide,which may be a potential gene therapy alone or as an adjuvant option in the treatment of lung cancer.

[ABSTRACT]AIM:ToinvestigatetheeffectofmiR-155-specificsiRNAaloneorincombinationwithcytosinear-abinoside (Ara-C) on the growth and apoptosis of Burkitt lymphoma Raji cells .METHODS: miR-155-specific siRNA and/or Ara-C were used to treat the cells .Quantitative real-time polymerase chain reaction was used to detect the expres-sion of miR-155.The growth of the cells was analyzed by CKK-8 assay.The cell apoptosis was determined by flow cytome-try.RESULTS:The miR-155 expression level of the cells transfected with miR-155 siRNA was significantly lower than that in the 2 control groups .Ara-C or miR-155 siRNA alone inhibited the growth of Raji cells in a dose-depend manner . miR-155 siRNA combined with Ara-C produced more inhibition of cell proliferation (P<0.05).After treatment for 48 h, the apoptotic rate of Raji cells in miR-155 siRNA+Ara-C group [(38.4 ±1.4)%] was higher than that in Ara-C group [(16.5 ±0.3)%] and miR-155 siRNA group [(14.6 ±0.3)%], with statistically significant difference (P<0.05). The expression of caspase-3 in Ara-C+miR-155 siRNA group was increased significantly as compared with Ara-C group and miR-155 siRNA group.CONCLUSION:miR-155-specific siRNA enhances the chemosensitivity of Raji cells to Ara-C by inducing apoptosis through the caspase-3 pathway .

ObjectiveTo express the hepatitis C virus (HCV) core gene in E . coli on a high level. Methods　The cDNA coding for HCV core protein was amplified by polymerase chain reaction (PCR). The PCR product was　purified and digested with restriction enzymes and inserted into the downstream of PRPL promoter of a high-level ex- pression vector pBV220. HCV core gene was expressed in E. coli in a non-fused form. The expression protein was analysed by SDS-PAGE , and its immunoactivity was tested by ELISA. Results Sequence analysis of the amplified PCR products confirmed that we have successfully cloned and expresssed the intact core protein of HCV. SDS-PAGE showed that a specific protein with a molecular weight of 21kDa at a level of 14. 0％ of the total bacterial proteins ap- peared in bacteria harboring pBV/HCVCore, while this protein was absent in the control bacteria harboring pBV220. The results of enzyme immunoassay analysis showed that this protein could be specifically recognized by the HCV pos- itive sera from patients with hepatitis C . Conclusion The intact HCV core protein was successfully expressed in E . coli in a non-fused form on a high level, and its immunoactivity was high.

Objective To develop an instrument for measuring ICU staff′s beliefs and attitudes towards patients′early mobility and to establish the psychometric characteristics of this scale. Methods Based on the ICU medical personnel questionnaire developed by Jolley and a large number of related literature, the item pool was formulated. Preliminary draft was formed through expert consultation and a small sample pre-test. Totally 336 ICU staff were surveyed for investigation to test the validity and reliability. Results ICU staff's beliefs and attitudes of patients′ early mobility scale consisted of 38 items; there were 34 belief scales and 4 attitude scales, the exploratory factor analysis identified five principal factors and explained for 60.50％variance. The item content validity index ranged from 0.667 to 1.000, the scale content validity index was 0.911. The Cronbach α coefficient of the beliefs scale was 0.927 and the attitudes scale was 0.822. The Cronbachαcoefficient of each dimension of the beliefs scale was 0.616-0.906. Conclusions The self-designed ICU staff's beliefs and attitudes of patients′ early mobility scale has good validity, reliability and applicability to ICU staff.

Objective:To investigate the features of chest computed tomography (CT) imaging and dynamic changes of severe corona virus disease 2019 (COVID-19).Methods:The clinical and CT data of 17 patients diagnosed with severe COVID-19 admitted to Chongqing Public Health Medical Center from January 24 to February 6, 2020 were collected. The first chest CT manifestations and the dynamic changes of imaging during treatment were retrospectively analyzed.Results:The first chest CT manifestations of the 17 patients showed that 16 cases presented with peripheral and subpleural distributions, and two cases presented with three lobes involved, one case with four lobes involved and 14 cases with five lobes involved, and 17 cases presented with ground-glass opacities, ten cases with consolidation, seven cases with subpleural line, nine cases with air bronchogram, three cases with thickened lobular septum, two cases with bronchiectasis, two cases with pleural effusion, three cases with lymphadenopathy with the short diameter of 1.0-1.2 cm.Among 16 patients who underwent repeated CT examination, the lesions of eight patients showed continuous improvement, and those of the other eight patients showed fluctuating changes.Conclusions:The CT findings of severe COVID-19 patients are mainly ground-glass opacities and consolidation, with the peripheral distribution. The range of lesions is wide, with five-lobe involvement mostly. Lymphadenopathy or pleural effusion is rare. Pynamic monitoring chest CT is useful for the evaluation for the therapeutic effects.