BACKGROUND: Lentivirus-mediated RNA interference technology has been widely used in the study of gene function because of its specificity, high inhibition efficiency and persistent effects. Virus packaging, transfection, as well as small hairpin RNA (shRNA)-coding sequence could affect the inhibition efficiency. Therefore, impact factors of RNA interference for human Bax inhibitor 1 (BI-1) was studied in this experiment.OBJECTIVE: To find the valid small interference RNA (siRNA) targeting human BI-1 gene by Lentivirus.DESIGN, TIME AND SETTING: Single sample observation was completed in Department of Medical Genetics, Basic Medical College, Peking University Health Science Center from September 2007 to December 2008.MATERIALS: 293T cell and SH-SY5Y cells were preserved in this laboratory; 4 shRNAs were designed through a use of online design tool by Ambion (www.ambion.com). METHODS: Several recombinant plasmids which expressed shRNAs targeting different regions of the BI-1 gene and labeled enhanced green fluorescent protein as a fusion gene were constructed. Four types of shRNA-expressing virions were obtained by cotransfection of shRNA-expressing plasmid and package protein-expressing plasmids into 293T cells. Green fluorescent protein expression was determined using flow cytometry to search the optimal package conditions. Real-time PCR and beta actin mRNA was used as an internal control, four types of recombinant viral supernatant and control viral supernatant were added on the SH-SY5Y cells, knock-down efficacies of the endogenous BI-1 gene were determined, and the RNA interference effective sequences were optimized. MAIN OUTCOME MEASURES: Intracellular green fluorescent protein expression rate of the cells infected with different packaging virus. RESULTS: The optimal infective packaging virus could be obtained when the ratio of plasmids pLentiLox3.7, REV, VSVG and RRE was 2:1:1:1 and the supernatants were collected 48 hours after transfection. Replacement of culture media 24 hours after transfection could increase the infection efficacy of the virions. shRNA targeting-2-17nt (start coding region) of BI-1 gene was most valid interference efficiency and could decrease the gene expression to 40%. CONCLUSION: Influencing factors of Lentivirus-mediated RNA interference technology virus packages were investigated in this study, which could be a foundation for constructing stable BI-1 knocked down neuronal cell model and for studying the abnormal expression of BI-1 related to the neuron apoptosis disease.

How does brain select and adjust the distributed neural activities to achieve its function? To address this problem,researchers introduce Granger causality analysis method to brain functional study,which deals with the estimation of causal influences among multi-variables.First,basic principles of Granger Causality and its improved algorithm structural vector autoregression (SVAR) are introduced.Then several technical problems are reviewed which should be noted when analyzing brain functional signals by Granger Causality Methods.In the end,the application foreground of Granger Causality in epilepsy localization is introduced by taking idiopathic generalized epilepsy as the example.

Objective To investigate the value of 18F-FDG PET/CT and serum CEA in patients with advanced gastric cancer after neoadjuvant chemotherapy combined with surgical treatment.Methods 96 cases of patients with advanced gastric cancer who underwent neoadjuvant chemotherapy combined with surgery as the research object,after more than 2 years of follow-up,PET/CT imaging and serum CEA levels were detected,and the diagnostic value of recurrence or metastasis of the two groups were evaluated and analyzed.Results Of the 96 patients enrolled in the study,there were 47 cases of recurrence and metastasis,PET/CT combined with CEA for recurrence or metastasis positive diagnosis rate and negative diagnosis rate was significantly higher than that of pure PET/CT and serum CEA,the difference was statistically significant(P<0.05).The sensitivity,specificity and accuracy of PET/CT combined with CEA in the diagnosis of recurrence or metastasis were higher than that of PET/CT and serum CEA,the difference was statistically significant(P<0.05).Conclusion The combined monitoring of 18F-FDG PET/CT imaging and serum CEA level in patients with advanced gastric cancer after neoadjuvant chemotherapy combined with surgical treatment is helpful to improve the diagnosis of metastasis or recurrence.

Objective To design nursing occupational safety and health curriculum reasonably.Methods With a semi-structured interview outline,focus group interviews among eight clinical nursing and nursing education specialists were conducted to develop the occupational safety and health curriculum design.Results It was important to set up nursing occupational safety and health curriculum.The main object,contents,teaching and evaluation methods were identified.Conclusions Occupational safety and health curriculum can be involved in nursing curriculum system to reduce occupational hazards and maintain physical and mental health of nursing students.

Objective To compare the roles of Toll-like receptor 4 (TLR4)/NF-κB signal pathway in acute lung injury (ALl) induced by blunt chest trauma and by blunt chest trauma-hemorrhagic shock and resuscitation (double hits) in rats.Methods Forty male Sprague-Dawley rats,aged 8 weeks,weighing 240-280 g,were randomly assigned into 3 equal groups (n =10 each) using a random number table:sham operation group (S group),blunt chest trauma group (T group),and blunt chest trauma and hemorrhagic shock and resuscitation group (group THSR).Lung contusion was induced in anesthetized rats by dropping a 300 g weight onto a precordial protective shield to direct the impact force away from the heart and toward the lungs.Blood was withdrawn via the femoral artery 5 min later until MAP was decreased to 35-45 mmHg within 15 min and maintained at this level for 60 min,followed by resuscitation.At 6 h after the model was established,the arterial blood samples were collected for blood gas analysis and detection of tumor necrosis factor-alpha (TNF-α) concentrations in serum.Oxygenation index (PaO2/FiO2) was calculated.The rats were then sacrificed and pulmonary specimens were obtained for determination of TLR4 expression and NF-κB ac tivity (by immunohistochemistry and Western blot) in lung tissues and for microscopic examination.Results Compared with group S,PaO2 and PaO2/FiO2 were significantly decreased,PaCO2 and TNF-α concentrations in serum were increased,TLR4 expression was up-regulated,and NF-κB activity was enhanced in T and THSR groups (P ＜ 0.05).Compared with group T,PaO2 and PaO2/FiO2 were significantly decreased,PaCO2 and TNF-α concentrations in serum were increased,TLR4 expression was up-regulated,and NF-κcB activity was enhanced in THSR group (P ＜ 0.05).The histopathological damage to lung tissues was aggravated in THSR group as compared with T group.Conclusion The role of TLR-4/NF-κB signal pathway in ALI induced by blunt chest traumahemorrhagic shock and resuscitation (double hits) is significantly stronger than that in ALI induced by blunt chest trauma alone in rats.

Objective To lateralize epileptic foci in interictal electroencephalography (EEG) signal by using causal analysis method.Methods On the basis of frequency domain causal analysis,the adapted directed transfer function (ADTF),power spectrum weighted ADTF(psADTF) method was proposed by applying the power spectrum information in defined frequency band with normalized ADTF,to fit the frequency information features of different epileptic wave.EEG signals of two groups of 30 epilepsy patients were analyzed by psADTF.Group Ⅰ included 15 presurgical patients and 104 epilepsy spikes were picked from EEG signals.Group Ⅱ included 15 outpatient patients and 98 epilepsy spikes were picked from EEG signals.Results 96 of 104 spikes of group Ⅰ were lateralized properly by psADTF according to surgery sites,and the accuracy rate was 92％.94 of 98 spikes of group Ⅱ were lateralized properly by psADTF according to three technicians' judgments,with the accuracy rate of 96％.Conclusion Our results proves that the psADTF method over interictal EEG spikes can be a great help to clinical epileptic foci lateralization.

Objective To explore the value of BI-RADS scoring system based on the sonographic features in the breast nodules.Methods In order to build a Logistic regression model,regression was made to analyse 401 patients ' sonographic features of breast nodules.A scoring system was developed based on the results of regression's filter and the weight of each factor,used to score and classify the other 243 patients.It's diagnostic value was evaluated through comparing all types of theoretic risk ranges of BI-RADS.Results Age,morphology,orientation,margin,echo pattern and microcalcifications in a mass were selected in the final step of the logistic regression analysis.By means of scoring system,the scores corresponding to BI-RADS 3,4a,4b,4c,5 classes are 6,7-8,9-15,16-22 and ≥23 respectively.Case study comprehensive score of BI-RADS 3-5 classification' s positive predictive values were 0,4.17％,21.43％,84.85％,1 00％,and the area under the ROC curve scoring system was 0.947.Conclusions The scoring system can objectively score and classify breast nodules,and therefore provide an effective reference for clinical evaluation of benign and malignant breast.

Objective To investigate the changes in plasma very long chain fatty acids (VLCFAs),and to explore its relationship with obesity-related index in obese children.Methods One hundred and sixty-six obese children aged 7 to 12 years old were investigated and 148 health children matched with age and sex were selected as control group.Their height,weight,and waist circumference (WC) were measured.The percentage of body fat (PBF) was tested by dual-energy X-ray absorptiometry.Fasting blood triglycerides (TG),total cholesterol (TC),high density lipoprotein-cholesterol (HDL-C),low density lipoprotein-cholesterol (LDL-C) levels,fasting plasma glucose,and fasting insulin (FINS) were determined.The body mass index (BMI),BMI-Z score,waist to height ratio (WHtR),and homeostasis model assessment for insulin resistance (HOMA-IR) were calculated.The plasma VLCFAs were analyzed by gas chromatography-mass spectrometry.Results (1) Compared with normal control children,body weight,BMI,BMI-Z score,WC,WHtR,PBF,TG,TC,LDL-C,FINS,and HOMA-IR in obese children were increased (all P ＜ 0.05),and the level of HDL-C was decreased (P ＜ 0.05).(2) The plasma levels of docosamonoenoic acid (C22 ∶ 1 n-9) and arachidonic acid (C20 ∶ 4n-6) were decreased while the levels of arachicacid (C20 ∶ 0) and eicosapentaenoic acid (C20 ∶ 5n-3) increased in obese children compared to non-obese children.(3) The linear correlation analysis showed that PBF was positively correlated with C20 ∶ 0 and C20 ∶ 5n-3,and negatively correlated with C20 ∶ 4n-6.WHtR was negatively correlated with C22 ∶ 1 n-9 and positively correlated with C20 ∶ 0 (4) The multiple stepwise regression analysis showed that C20 ∶ 0 was the main factor for PBF,and C22 ∶ 1 n-9 and C20 ∶ 0 were the main factors for WHtR.Conclusion The metabolic abnormality of plasma very long chain fatty acids exists in obese children.The changes in C20 ∶ 0,C22 ∶ 1 n-9,and C20 ∶ 5n-3 may be associated with obesity in children.

Objective: PCBP1 is a family member of heterogeneous nuclear ribonucleoproteins (hnRNPs) that belong to RNA-binding proteins and bear three KH domains. The protein plays a pivotal role in post-transcriptional regulation for RNA metabolism and RNA function in gene expression. We hy-pothesized and were going to identify that the regulatory function of PCBP1 is performed through different complexes of proteins that include PCBP1. Methods: To test our hypothesis, approaches of protein wal-king with a yeast two-hybrid system (Y2H), pulling down in yeasts, co-immunoprecipitation and immu-nofluorescent microscopy assay were employed in this study. The PCBP1 was used as the initial "walker" to search for its interaction partner(s). Results: Candidate proteins including MYL6, PECAM1, CSH1,RAB7, p57KIP2, ACTG1, RBMS1 and PSG4-1ike were identified with selection mediums and preceding methods. Conclusion: With these candidate protein molecules, some protein complexes associating with PCBP1 are proposed, which may help in a better understanding of physiological functions of PCBP1 and proved evidence that PCBP1 is involved in variant biological pathways.

ObjectiveTo investigate the correlation of hippocampal synaptic plasticity with spatial learning and memory under normal and pathological condition,and provide experimental evidence for the coincidence of hippocampal late-phase long-term potentiation (L-LTP) and behavioral experiments.Methods 38 SD rats were randomly divided into two groups,control and AD model.First,Morris water maze was used to test the ability of spatial learning and memory of rats.The escape latencies for rats to search for an underwater platform in 5 days of navigation tests and the swimming time percentage in target qtuadrant on the 6th day after withdrawing the platform in probe trails were recorded.Then,in vivo hippocampus L-LTP of field excitatory postsynaptic potential (fEPSP)in CA1 region was recorded after delivering high frequency stimulation (HFS).ResultsBilateral intrahippocampal injection of 4 nmol amyloid β peptide ( Aβ 25-35 ) significantly impaired spatial learning and memory of rats in water maze tests,as well as in vivo hippocampal L-LTP.In control group,there was a significant negative correlation between the amplitude of fEPSP and the escape latency ( r =-0.8306,P ＜ 0.01 ) and a significant positive correlation between the amplitude of fEPSP and the swimming time percentage in target quadrant ( r=0.7709,P＜0.01 ).In AD model group,similar correlations were found,with a correlation coefficient of r =-0.7675 (P ＜0.01 ) and r =0.8049 (P ＜ 0.01 ),respectively.When putting all data from the two groups together,the hippocampal L-LTP was more correlated with escape latency ( r =-0.9124,P ＜ 0.01 ) and swimming time percentage ( r=0.9745,P＜0.01).ConclusionThere is very close correlation between the hippocampal L-LTP and the spatial learning and memory behavior in rats,suggesting that the hippocampal L-LTP may be involved in the electrophysiological mechanism of spatial learning and memory in rats,and the impairment of L-LTP could partly represent the deficits in cognitive function of animals.