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Objective To investigate the Rv2346c gene function through constructing Rv2346c gene knockout strains of Mycobacterium tuberculosis (M . tuberculosis) mediated by bacteriophage and observing its virulence after infecting mice lung tissue in vivo .Methods The affinal exchange sites (AES) of the target gene was built ,and then integrated into the phage genomes of M .tuberculosis for harvesting the phagemids .The phagemids was imparted into Mycobacterium smegmatis to get recombinant phages with the same AES .A high titer of the recombinant phages was harvested through amplification in vitro . The M .tuberculosis was transfected and coated on solid medium with hygromycin resistance and cultured for 4 weeks at 37℃ .Single clone was picked out and gene knock-out was confirmed by PCR . Then C57BL/6J mice were infected with either wild type strain (WT ) or knockout strain (KO ) of M . tuberculosis .Mice mortality ,lung tissue inflammation and colony-forming units (CFU ) counts in vitro were observed 6 to 8weeks post infection with different strains . Paired-samples t test was used for comparison between groups ,chi-square test was used for comparison of rates .Results The products of PCR and inserted fragment sizes were consisted with the expectation and confirmed to be the target gene . The target fragment of Rv2346c was removed successfully and the mice were infected for 6-8 weeks .Themice infected with Rv2346c KO strain had reduced mortality (53％ vs 20％ ,χ2 =6 .1112 ,P<0 .05) ,lung tissue inflammation (1040 ± 89 vs 1960 ± 56 ,t=7 .1016 ,P<0 .05) and CFU count in vitro (15 .0 ± 0 .8 vs 90 .0 ± 1 .5 ,t=23 .0361 , P<0 .05) compared with WT strain 6-8 weeks post infection .Conclusion Rv2346c gene knockout strains of M . tuberculosis mediated by bacteriophageis are successfully constructed ,which establishes the foundation for the future gene function study of Rv2346c .
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Objective@#To investigate whether Pseudomonas aeruginosa recombinant protein PA3611 can induce the in vitro epithelial-mesenchymal transformation (EMT) of rat bronchial epithelial cells.@*Methods@#A series of processes including DNA synthesis, gene amplification, vector construction, induction of expression and protein purification was used to synthesize the recombinant protein PA3611. CCK-8 kit was used to detect the proliferation of bronchial epithelial cells after stimulation with the protein PA3611. Morphological changes in bronchial epithelial cells were observed. Western blot and qPCR were performed to measure the expression of E-cadherin (E-CAD) and α-smooth muscle actin (α-SMA). T test was used for statistical analysis.@*Results@#DNA sequencing verified the successful preparation of the recombinant protein PA3611. PA3611 inhibited the proliferation (P<0.05) and induced the EMT of bronchial epithelial cells. Moreover, it also inhibited the expression of E-CAD protein, but promoted the expression of α-SMA (P<0.05).@*Conclusion@#The recombinant protein PA3611 can induce the EMT of bronchial epithelial cells and the underlying mechanisms are worthy of further investigation.
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Objective To screen B and T cell antigen epitopes on Acinetobacter baumannii outer membrane protein 33×103-36×103 (OMP33-36).Methods B and T cell epitopes on OMP33-36 of Acinetobacter baumannii were predicted by bioinformatics methods and synthesized.Recombinant expression plasmid pET-30a-OMP33-36 was cloned and used to express OMP33-36 in a prokaryotic expression system.The expressed OMP33-36 was used to immunize BALB/c mice after purification.Serum sample was collected from each mouse in immunization and negative control groups, and then analyzed by indirect ELISA with synthesized peptides to identify B cell epitopes.Splenocytes were separated from every mouse and then cultured with each of the synthesized peptides, respectively.Double sandwich ELISA was performed to detect IFN-γ secretion in the supernatant of cell cultures for screening of T cell epitopes.Results Candidates of B and T cell epitopes were constructed, which were PB1, PB2, PB3, PT1, PT2 and PT3.Results of the indirect ELISA showed that peptides PB1 and PB2 reacted with the serum samples collected from immunized mice and A450 values of the immunization group were significant higher than those of the negative control group.Compared with the negative control group, enhanced secretion of IFN-γ following peptide PT3 stimulation was observed in the immunization group as indicated by the double sandwich ELISA.Conclusion Two B cell epitopes PB1 and PB2, and one T cell epitope PT3 on the OMP33-36 of Acinetobacter baumannii were successfully constructed and screened out.
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Objective To evaluate the rewarming and?anesthetic recovery regularity in different body mass index(BMI) patients with primary liver cancer by the same rewarming measures. Methods The data of 67 primary liver cancer patients with hypothermia after surgery were analyzed retrospectively and divided into three groups (low BMI group:BMI<18.50 kg/m2,normal BMI group: BMI 18.50-22.99 kg/m2, and high BMI group: BMI≥23.00 kg/m2) according to the standard of Asian BMI. Rewarming time and speed, spontaneous breathing recovery time,waking time and shivers in the three groups were observed and compared. Results Rewarming time, spontaneous breathing recovery time,waking time were (114.75± 21.91), (62.60±23.47), (94.65±20.54) min in low BMI group, (93.46±30.39), (41.19±21.47), (66.11±24.78) min in normal BMI group and (61.43±16.37), (25.81±8.90), (50.57±10.41) min in high BMI group,there were significant differences among three groups (F=25.300, 18.962, 25.647, all P<0.05). Rewarming speed was (0.85±0.13) ℃/h in high BMI group, (0.44±0.10) ℃/h in normal BMI group, (0.47±0.16) ℃/h in low BMI group,there were significant differences among three groups(F=65.810, P<0.05). Conclusions Rewarming for a long time in the primary liver cancer patients with low BMI and hypothermia after surgery by the same measures.More attentions should be paid to management of low BMI patients in the rewarming process, and aggressive measures should be taken to restore body temperature to normal.