In order to increase antigenicity of H. pylori-specific antigens and decrease the cost of further industrial production, we used a special PCR with linking primers to construct a fusion gene containing H.pylori ureB and hpaA genes and E.coli ltB gene, and to costract its prokaryotic expression system pET42a-ltB-ureB-hpaA-E.coliBL21DE3. The sequencing result indicated the 100% nucleotide sequence homology of the constructed ltB-ureB-hpaA fusion gene compared to those of the original separated genes. Output of the target recombinant protein rLTB-UreB-HpaA was approximate 15% of the total bacterial proteins measured by SDS-PAGE. The rLTB-UreB-HpaA could induce the immunized rabbits to produce specific antibodies with immunodiffusion titer of 1∶8, and could combine to the commercial rabbit antibody against the whole cell of H.pylori as well as rabbit anti-UreB and anti-HpaA sera by using Western bolt assays. Using GM1-ELISA, the ability of rLTB-UreB-HpaA binding to bovine GM1 was confirmed.And rLTB-UreB-HpaA (200 μg per mouse) could prevent 100% of the immunized BaLb/C mice from H.pylori strain SS1 infection. The co-administration with 10 μg rLTB, the rUreB or rHpa could increase its protective rates in the immunized mice from 66.7% to 81.8% and 83.3%, respectively. All these data leads a conclusion that rLTB-UreB-HpaA is a great potential as a practical genetic engineering vaccine to prevent H.pylori infection.

Objective To study the effects of hyperbaric oxygen (HBO) preconditioning (PC) on motor function and mitochondrial apoptosis after spinal cord injury (SCI) in rats.Methods Thirty-six healthy,male Wistar rats were randomly divided into 3 groups (each n =12):a control (CON) group,an SCI model group and an HBO-PC group.The SCI group and the HBO-PC group after 7 sessions of HBO-PC treatment were subjected to SCI modeling using Allen's method.The CON group was not given any special treatment.Two weeks after the modeling,Basso,Beattie,and Bresnahan BBB scale was used to rate the rats' locomotor function,and the T8 segment of the rats' spinal cords was removed.After extracting total RNA from the spinal cord tissue,real-time quantitative PCR was used to detect the mRNA expression levels ofcaspase-3,cytochrome C (CYC),Bak,Bax,Bcl-x and Bcl-2 in the spinal cord tissue.Results Two weeks after modeling,compared with the CON group,the average BBB locomotion score of the SCI model group had decreased.In contrast,caspase-3,CYC,Bak and Bax mRNA expressions had increased significantly.Compared with the CON group,the average BBB locomotion score of the HBO-PC group had decreased,caspase-3 expression had increased,and Bax mRNA expression had decreased,but the differences in the changes between the two groups were not statistically significant.Bak mRNA expression increased and CYC expression decreased,and the difference between the two groups was statistically significant.Compared with the SCI model group,the average BBB locomotion score of the HBO-PC group increased while caspase-3,CYC,Bak and Bax mRNA expressions decreased,but none of these differences between the two groups was statistically significant.Bak mRNA expression increased and CYC mRNA expression decreased,and those differences between the two groups were statistically significant.Bcl-x and Bcl-2 mRNA expression in the CON,HBO-PC and SCI model groups were significantly different.Conclusion HBO-PC can reduce the loss of motor function after SCI,at least in rats.The mechanism may be related to reducing neuron mitochondrial apoptosis.

Objective To study biological characteristics of R5 tropic human immunodeficiency virus (HIV)-1 strains in different disease stage. Methods Primary clinical viruses were isolated from fresh peripheral blood mononuclear cells (PBMC) using co-culture methods; meanwhile, viral co receptor usage and infectivity were tested using flow cytometry on GHOST (3) cell lines,which expressed CD4 receptor and CC ehemokine receptor 5 (CCR5) or CXCR4 eoreceptor; to identified CCR5 tropic viruses(R5 tropic strains). Viral replication kinetics was detected in PBMCs. Plasma viral load was measured using an HIV-1 nucleotide fluorescence quantification assay kit. Results There were 22 individuals with HIV-1 subtype B' infection, in which 11 were CD4>0. 2 × 109/L and 11 were CD4≤0. 2 × 109/L. All isolated viruses used CCR5 coreceptor and therefore were HIV-1 R5 tropic strains. The infectivity of R5 tropic strains isolated from patients with CD4≤0.2 × 109/L was (7.392 7 ± 4. 584 2) % ; while the infectivity of R5 tropic strain from patients with CD4>0. 2 × 109/L was (2. 613 6 ± 1. 610 5)%. There were significant statistical difference(t= 3. 262, P<0.05). The possibility of viral replication became strong after the day 7 post-infection. There was a significant difference of viral replication between two groups in the day 7,10, 15 post-infection(t value was 3. 771, 2. 509 and 2. 260 respectively, P<0. 05). The possibility of viral replication was higher in CD4≤0.2 ×109/L group than that of CD4>0.2 × 109/L group. The logarithm of viral load was (5. 606 8 ± 0. 815 1 ) copies/mL in CD4≤0.2 × 109/L group and (4. 729 8 ± 0. 431 6) copies/mL in CD4> 0.2 × 109/L group. There was a significant difference between two groups(t = 3. 771 ; P<0.05). Conclusion Viral infection and replication are enhanced during progression of disease, even if viral coreceptor usage do not switch from CCR5 to CXCR4.

Through studying the process of glycerol fermentation to 1, 3-propanediol(1, 3-PD) by Klebsiella pneumoniae, it was found that the cell growth and product (or by-product) production were under salt stress. Cell growth and product formation kept high rate at low salt concentration. High salt concentration led to low growth of cells, final concentration of 1, 3-PD and conversion from glycerol to 1, 3-PD, and, 1, 3-propanediol oxidoreductase activity decreased. When the salt concentration in 5 m3 bioreactor was controlled under appropriate manner, the concentration of 1, 3-PD production was markedly enhanced. The final 1, 3-PD concentration ,the conversion of glycerol to 1, 3-PD and productivity were 64 g/L, 61% and 2.1 g/(L x h).
Alcohol Dehydrogenase ; Alcohol Oxidoreductases ; metabolism ; Culture Media ; Culture Techniques ; Fermentation ; Glycerol ; metabolism ; Klebsiella pneumoniae ; growth & development ; metabolism ; physiology ; Propylene Glycols ; metabolism ; Sodium Chloride ; pharmacology ; Stress, Physiological

OBJECTIVE: To design and construct a graphene oxide (GO)/silver nitrate (Ag₃PO₄)/chitosan (CS) composite coating for rapidly killing bacteria and preventing postoperative infection in implant surgery. METHODS: GO/Ag₃PO₄ composites were prepared by ion exchange method, and CS and GO/Ag₃PO₄ composites were deposited on medical titanium (Ti) sheets successively. The morphology, physical image, photothermal and photocatalytic ability, antibacterial ability, and adhesion to the matrix of the materials were characterized. RESULTS: The GO/Ag₃PO₄ composites were successfully prepared by ion exchange method and the heterogeneous structure of GO/Ag₃PO₄ was proved by morphology phase test. The heterogeneous structure formed by Ag₃PO₄ and GO reduced the band gap from 1.79 eV to 1.39 eV which could be excited by 808 nm near-infrared light. The photothermal and photocatalytic experiments proved that the GO/Ag₃PO₄/CS coating had excellent photothermal and photodynamic properties. In vitro antibacterial experiments showed that the antibacterial rate of the GO/Ag₃PO₄/CS composite coating against Staphylococcus aureus reached 99.81% after 20 minutes irradiation with 808 nm near-infrared light. At the same time, the composite coating had excellent light stability, which could provide stable and sustained antibacterial effect. CONCLUSION GO/Ag₃PO₄/CS coating can be excited by 808 nm near infrared light to produce reactive oxygen species, which has excellent antibacterial activity under light.
Chitosan ; Silver Nitrate ; Titanium ; Anti-Bacterial Agents/pharmacology* ; Coloring Agents