AIM: To evaluate whether attenuated Salmonellatyphimurium producing Helicobacter pylori ( H pylori) urease subunit B (UreB) could induce systemic immune responses against H pylori infection.METHODS: Attenuated S. typh...AIM: To evaluate whether attenuated Salmonellatyphimurium producing Helicobacter pylori ( H pylori) urease subunit B (UreB) could induce systemic immune responses against H pylori infection.METHODS: Attenuated S. typhimurium SL3261 was used as a live carrier of plasmid pTC01-UreB, which encodes recombinant H pylori UreB protein. Balb/c mice were given oral immunization with two doses of SL3261/pTC01-UreBat a 3-wk interval. Twelve weeks after oral immunization of mice, serum IgG antibodies were evaluated by ELISA assay. Gamma interferon (IFN-γ) and interleukin 10 (IL-10)in the supernatant of spleen cell culture were also assessed by ELISA.RESULTS: After oral immunization of mice, serum specific IgG antibodies against UreB in vaccine group were much higher than that in PBS and native Salmonella SL3261control groups (A450, 0.373±0.100 vs 0.053±0.022, 0.142±0.039, respectively, P＜0.01). Moreover, IFN-γ in vaccine group was on average 167.53±29.93 pg/mL, which showed a significant increase vs that of PBS control group (35.68±3.55 pg/mL, P＜0.01). There was also a tremendous increase of IL-L0 in vaccine group compared to PBS and SL3261 control groups (275.13±27.65 pg/mL vs 56.00±7.15 pg/mL, 68.02±15.03 pg/mL, respectively, P＜0.01). In addition, no obvious side effects in mice and no change in gastric inflammation were observed. CONCLUSION: The multiple oral immunizations with the attenuated S. typhimurium expressing H pylori UreB could induce significant systemic immune responses, suggesting it may be used as oral vaccine against H pylori infection.展开更多
Exactly modeling of anti-shock isolation system of a marinein its design.For an isolation system with some rigid stops,the enginebody and isolators as springs and dampers,for which three nonlinearengine is an importan...Exactly modeling of anti-shock isolation system of a marinein its design.For an isolation system with some rigid stops,the enginebody and isolators as springs and dampers,for which three nonlinearengine is an important stepcan be modeled as a rigidfactors exist.This paper isaimed at that whether there are any nonlinear factors can be neglected?In this paper, the marine en-gine with anti-shock isolation system is firstly suggested as a vibro-impact system to study.An ap-proximate discrete model described by impact Poincaré map can be derived.Analysis of example shows that O-order approximate model conceals possible chaotic phenomenon; simultaneously,limiting clearance of stops can influence bifurcation area in bifurcation diagram.展开更多
Previously, we isolated a vernalization-related gene, VER2, from winter wheat (Triticum aestivum L.) and its expression was restricted in the immature leaves of vernal-ized wheat seedlings. To further investigate the ...Previously, we isolated a vernalization-related gene, VER2, from winter wheat (Triticum aestivum L.) and its expression was restricted in the immature leaves of vernal-ized wheat seedlings. To further investigate the regulation of VER2 expression and the function of its promoter, we iso-lated a 41.7 kb genomic clone containing VER2 gene from a transformation-competent artificial chromosome (TAC) li-brary of wheat (Triticum aestivum-Haynaldia villosa). The sequence analysis showed that there were eleven predicted genes in the TAC. The exons of gene 3 corresponded to the cDNA sequence of VER2 gene. Analysis of VER2 promoter structure showed that there were three small repeat se-quences divided by two large repeat sequences. The putative response elements, such as abscisic acid response elements (ABRE), MeJA-response elements (Me-JARE), low-tempe- rature response elements (LTR), endosperm expression ele-ments, MYB binding sites and similar elements to GA re-sponse elements (GARE), were involved in the VER2 pro-moter region. Construct containing the VER2 promoter (-5895 to +73) driving GFP reporter gene was bombarded into vernalized or non-vernalized immature leaves in wheat. The vernalized immature leaves showed bright green fluo-rescence after incubation for 24 h, however, the green fluo-rescence was not observed in the non-vernalization leaves under the same condition. These results suggested that vernalization was essential for the function of VER2 promoter in the immature leaves of winter wheat.展开更多
文摘AIM: To evaluate whether attenuated Salmonellatyphimurium producing Helicobacter pylori ( H pylori) urease subunit B (UreB) could induce systemic immune responses against H pylori infection.METHODS: Attenuated S. typhimurium SL3261 was used as a live carrier of plasmid pTC01-UreB, which encodes recombinant H pylori UreB protein. Balb/c mice were given oral immunization with two doses of SL3261/pTC01-UreBat a 3-wk interval. Twelve weeks after oral immunization of mice, serum IgG antibodies were evaluated by ELISA assay. Gamma interferon (IFN-γ) and interleukin 10 (IL-10)in the supernatant of spleen cell culture were also assessed by ELISA.RESULTS: After oral immunization of mice, serum specific IgG antibodies against UreB in vaccine group were much higher than that in PBS and native Salmonella SL3261control groups (A450, 0.373±0.100 vs 0.053±0.022, 0.142±0.039, respectively, P＜0.01). Moreover, IFN-γ in vaccine group was on average 167.53±29.93 pg/mL, which showed a significant increase vs that of PBS control group (35.68±3.55 pg/mL, P＜0.01). There was also a tremendous increase of IL-L0 in vaccine group compared to PBS and SL3261 control groups (275.13±27.65 pg/mL vs 56.00±7.15 pg/mL, 68.02±15.03 pg/mL, respectively, P＜0.01). In addition, no obvious side effects in mice and no change in gastric inflammation were observed. CONCLUSION: The multiple oral immunizations with the attenuated S. typhimurium expressing H pylori UreB could induce significant systemic immune responses, suggesting it may be used as oral vaccine against H pylori infection.
文摘Exactly modeling of anti-shock isolation system of a marinein its design.For an isolation system with some rigid stops,the enginebody and isolators as springs and dampers,for which three nonlinearengine is an important stepcan be modeled as a rigidfactors exist.This paper isaimed at that whether there are any nonlinear factors can be neglected?In this paper, the marine en-gine with anti-shock isolation system is firstly suggested as a vibro-impact system to study.An ap-proximate discrete model described by impact Poincaré map can be derived.Analysis of example shows that O-order approximate model conceals possible chaotic phenomenon; simultaneously,limiting clearance of stops can influence bifurcation area in bifurcation diagram.
文摘Previously, we isolated a vernalization-related gene, VER2, from winter wheat (Triticum aestivum L.) and its expression was restricted in the immature leaves of vernal-ized wheat seedlings. To further investigate the regulation of VER2 expression and the function of its promoter, we iso-lated a 41.7 kb genomic clone containing VER2 gene from a transformation-competent artificial chromosome (TAC) li-brary of wheat (Triticum aestivum-Haynaldia villosa). The sequence analysis showed that there were eleven predicted genes in the TAC. The exons of gene 3 corresponded to the cDNA sequence of VER2 gene. Analysis of VER2 promoter structure showed that there were three small repeat se-quences divided by two large repeat sequences. The putative response elements, such as abscisic acid response elements (ABRE), MeJA-response elements (Me-JARE), low-tempe- rature response elements (LTR), endosperm expression ele-ments, MYB binding sites and similar elements to GA re-sponse elements (GARE), were involved in the VER2 pro-moter region. Construct containing the VER2 promoter (-5895 to +73) driving GFP reporter gene was bombarded into vernalized or non-vernalized immature leaves in wheat. The vernalized immature leaves showed bright green fluo-rescence after incubation for 24 h, however, the green fluo-rescence was not observed in the non-vernalization leaves under the same condition. These results suggested that vernalization was essential for the function of VER2 promoter in the immature leaves of winter wheat.
