AIM: To construct eukaryotic expression vector of small interfering RNA(siRNA) specific to bcl-2 and investigate the effect of recombinant plasmid on suppressing bladder cancer cell growth.METHODS: siRNA of bcl-2 gene was designed according to the principle of RNAi-based medicine, and was converted into cDNA coding expression of small hairpin RNAs(shRNA) of siRNA. The cDNA was synthesized and inserted into plasmid pGenesil-1. The recombinant eukaryotic expression vectors of pGenesil-1545 and pGenesil-1555 were controlled by the U6 promoter of RNA polymerase Ⅲ, identified by the restriction map and the sequence analysis, and transfected into T24 cells. After T24 cells were transfected for 72 h, expression of bcl-2 mRNA was assayed by RT-PCR; and MTT was used to observe the proliferation of T24 cells.RESULTS: The recombinant plasmids of pGenesil-1545 and pGenesil-1555 were identified by the restriction map and the sequence analysis. The sequences completely coincided with the designs. The expression of the bcl-2 mRNA in T24 cells transfected with recombinant plasmid decreased nearly 80%, and the growth of T24 cells was suppressed significantly.CONCLUSION: The siRNA eukaryotic expression vector against bcl-2 gene is successfully constructed. It effectively downregulates the expression of bcl-2 in T24 cells and suppresses the cell growth.

OBJECTIVETo study the changes in biological behaviors of meningitis E. coli K1 strain E44 after deletion of polyphosphate kinase 1 (ppk1) gene and explore the role of ppk1 in the pathogenesis of E. coli K1-induced meningitis.

METHODSThe wild-type strain E. coli K1 and ppk1 deletion mutant were exposed to heat at 56 degrees celsius; for 6 min, and their survival rates were determined. The adhesion and invasion of the bacteria to human brain microvascular endothelial cells (HBMECs) were observed using electron microscopy and quantitative tests. HBMECs were co-incubated with wild-type strain or ppk1 deletion mutant, and the cytoskeleton rearrangement was observed under laser scanning confocal microscope.

RESULTSThe survival rate of the ppk1 deletion mutant was significantly lower than that of the wild-type strain after heat exposure. The ppk1 deletion mutant also showed lowered cell adhesion and invasion abilities and weakened ability to induce cytoskeleton rearrangement in HBMECs.

CONCLUSIONSppk1 gene is important for E.coli K1 for heat resistance, cell adhesion and invasion, and for inducing cytoskeletal rearrangement in HBMECs.

Brain ; cytology ; Cells, Cultured ; Cytoskeleton ; Endothelial Cells ; cytology ; microbiology ; Escherichia coli ; genetics ; physiology ; Escherichia coli Proteins ; genetics ; Gene Deletion ; Humans ; Phosphotransferases (Phosphate Group Acceptor) ; genetics

Objective To analyze the pathogenic features and risk factors of hospital-acquired pneumonia in patients with acute spontaneous intracerebral hemorrhage (sICH) in intensive care unit (ICU).Methods The clinical data of 110 patients with sICH admitted in ICU during January 2015 and February 2017 were collected.Patients were divided into hospital-acquired pneumonia group (HAP group,n =66) and non-HAP group (n =44).Multivariate Logistic regression was used to study the risk factors of HAP,and pathogen distribution and drug susceptibility were analyzed.Results Multivariate Logistic regression demonstrated that long-term mechanical ventilation (OR =1.028,95％ CI 1.012-1.044,P ＜ 0.01),lower score of glasgow coma scale (GCS) (OR =1.550,95％ CI 1.148-2.093,P ＜ 0.01),prolonged hospital stay (OR =1.131,95％ CI 1.046-1.224,P ＜0.01) and underlying diseases more than two forms (OR =9.793,95％ CI 1.012-1.044,P ＜ 0.01) were the independent risk factors of HAP,while high plasma albumin level was protective factor for HAP (OR =0.897,95％ CI O.811-0.992,P ＜ 0.05).One hundred and eighty-three bacterial strains were isolated from 66 patients,the top 4 pathogens were Acinetobacter baumannii (28.96％,53/183),Klebsiella pneumonia (15.85％,29/183),Pseudomonas aeruginosa (13.11％,24/183) and Staphylococcus aureus (12.02％,22/183).Acinetobacter baumannii,Klebsiella pneumoniae and Pseudomonas aeruginosa were highly resistant to the majority of antibiotics,some of which even reached 100％.Staphylococcus aureus showed high resistance to macrolides,fluoroquinolones and β-lactam antibiotics.Conclusions There is high incidence of HAP in patients with sICH,and the pathogenic bacteria are mainly gram-negative bacteria.Effective prevention and treatment measures should be taken to reduce the incidence of HAP for patients with sICH in ICU.

OBJECTIVE： To compare inhibitory effects of ethanol extract of different medicinal parts （root， stem， leaf， seed， flower and flesh） from Syzygium jambos on the activities of α-glycosidase and α-amylase. METHODS： Using half-inhibitory concentration value （IC50） as evaluation index， acarbose as positive control， inhibitory effects of ethanol extract of different medicinal parts from S. jambos on the activities of α-glycosidase （from yeast and small instestine in mice） and α-amylase were evaluated with in vitro inhibition model. The enzymatic dynamics and Lineweaver-Burk methods were used to analyze the inhibitory type of the best medicinal part on the activities of α-glycosidase and α-amylase. RESULTS： In the yeast α-glucosidase inhibitory activity test， the order of inhibitory activity was S. jambos seed＞S. jambos stem＞S. jambos leaf＞S. jambos root＞S. jambos flower＞S. jambos flesh＞acarbose. In the mice intestine α-glucosidase inhibitory activity test， the order of inhibitory activity was S. jambos seed＞S. jambos stem＞S. jambos root＞S. jambos leaf＞S. jambos flower＞S. jambos flesh＞acarbose. In the α-amylase inhibitory activity test， the order of inhibitory activity was acarbose＞S. jambos seed＞S. jambos stem＞S. jambos root＞S. jambos leaf＞S. jambos flesh＞S. jambos flower. Ethanol extract of S. jambos seed had the stronger inhibition activity against α-glucosidase from yeast，α-glucosidase from small intestine in mice and α-amylase than other medicinal parts [IC50 were（6.64±0.24）， （32.77±2.46） and （41.18±1.63） μg/mL]. Ethanol extract of S. jambos seed had the stronger inhibition activity against α-glucosidase than acarbose [IC50 to α-glucosidase from yeast and α-glucosidase from small intestine in mice were （2 833.33±5.48）， （1 304.21±6.45） μg/mL] （P＜0.05）. The inhibitory effect of ethanol extract from S. jambos on the activity of α-amylase was less than that of acarbose [IC50 was （27.27±1.24） μg/mL] （P＜0.05）. Enzymatic dynamics showed that the inhibitory type of ethanol extract from S. jambos seed on α-glucosidase and α-amylase were both reversible competitive inhibition. CONCLUSIONS： Among different parts of S. jambos such as root， stem， leaf， seed， flower and flesh， S. jambos seed shows the strongest inhibitory effects on the activities of α-glucosidase and α-amylase， which has the value of being developed for the treatment of diabetes or health food.