Objective To investigate the molecular characteristics and intracellular growth ability of Legionella pneumophila(L. pneumophila) strains from 1989 to 2016 in Sichuan Province, China. Methods Seventy-nine isolates of ...Objective To investigate the molecular characteristics and intracellular growth ability of Legionella pneumophila(L. pneumophila) strains from 1989 to 2016 in Sichuan Province, China. Methods Seventy-nine isolates of L. pneumophila were collected from environmental and clinical sources, including cooling towers, hot springs, bath water, fountains, and patients, and identified with 16 S rRNA gene analysis and serum agglutination assay. The isolates were then typed by Sequence-Based Typing(SBT), and Genotyping of forty-two LP1 strains were analyzed by means of multiple-locus VNTR analysis with 8 loci(MLVA-8). All strains were further analyzed for two virulence genes: Legionella vir homologue(lvh) and repeats in structural toxin(rtx A). The intracellular growth ability of 33 selected isolates was determined by examining their interaction with J774 cells. Results All isolates were identified to L. pneumophila including 11 serogroups, among which the main serogroup were LP1, accounting for 54.43%. Thirty-three different sequence types(STs) from five main clonal groups and five singletons were identified, along with 8 different MLVA patterns. Both the lvh and rtx A loci were found in all 79 strains. Thirty isolates showed high intracellular growth ability in J774 cells. Conclusion L. pneumophila is a potential threat to public health, and effective control and prevention strategies are urgently needed.展开更多
The effects of epidermal growth factor （EGF） on proliferation of G15 glioma cells and the possible mechanisms were investigated. GFAP and EGFR expression was detected by immunohistochemical method. After the cells w...The effects of epidermal growth factor （EGF） on proliferation of G15 glioma cells and the possible mechanisms were investigated. GFAP and EGFR expression was detected by immunohistochemical method. After the cells were treated with EGF at different concentrations, cell count method was used to determine the proliferation of glioma cells, cell cycle and apoptosis were analyzed by flow cytometry （FCM）, and laser scan confocal microscope （LSCM） was used to measure the cytoplasmic free calcium. The results showed that GFAP was diffusedly expressed in GLI5 cells and EGFR was over-expressed. EGF at doses of ≤ 1 ng/mL could significantly stimulate cell proliferation, cells in phase G0/G1 decreased, and those in phase S increased. EGF at doses of 10 and 100ng/ml could inhibit the cell proliferation significantly, and the apoptosis ratio in high dose of EGF group was higher than in control group. EGF could significantly induce a quick rise of intracellular free calcium, but the peak value of intracellular free calcium activated by high dose of EGF was higher than by low dose of EGF. It was suggested that EGF had a dual effect on gliomas： low dose of EGF could stimulate the cell proliferation of gliomas, but high dose of EGF could induce the cell apoptosis and inhibit the proliferation of gliomas, which might be contributed to the difference of intracellular free calcium.展开更多
目的 :探讨细菌脂多糖 (lipopolysaccharide,L PS)对 NIH 3T3细胞增生、胞内游离钙及 c AMP浓度的影响。 方法 :以中性红比色法检测细胞生长 ,酚试剂法检测细胞蛋白质合成 ,并动态检测 L PS对胞内游离钙和 c AMP浓度的影响。 结果 :1...目的 :探讨细菌脂多糖 (lipopolysaccharide,L PS)对 NIH 3T3细胞增生、胞内游离钙及 c AMP浓度的影响。 方法 :以中性红比色法检测细胞生长 ,酚试剂法检测细胞蛋白质合成 ,并动态检测 L PS对胞内游离钙和 c AMP浓度的影响。 结果 :1微量 L PS可促进细胞生长及蛋白质合成 ;2 L PS作用后 3～ 5 min可使胞内游离钙浓度升高 ,作用 1 m in后使 c AMP浓度升高 ,并保持较高水平。 结论 :胞内游离钙 ([Ca2 + ]i)及 c AMP是 L PS对展开更多
基金supported by grants from the National Natural Science Foundation of China [81672048]the Youth Innovation Project of Sichuan Medical Association Foundation [Q15081]the Priority Project on Infectious Disease Control and Prevention [2018ZX10714002]
文摘Objective To investigate the molecular characteristics and intracellular growth ability of Legionella pneumophila(L. pneumophila) strains from 1989 to 2016 in Sichuan Province, China. Methods Seventy-nine isolates of L. pneumophila were collected from environmental and clinical sources, including cooling towers, hot springs, bath water, fountains, and patients, and identified with 16 S rRNA gene analysis and serum agglutination assay. The isolates were then typed by Sequence-Based Typing(SBT), and Genotyping of forty-two LP1 strains were analyzed by means of multiple-locus VNTR analysis with 8 loci(MLVA-8). All strains were further analyzed for two virulence genes: Legionella vir homologue(lvh) and repeats in structural toxin(rtx A). The intracellular growth ability of 33 selected isolates was determined by examining their interaction with J774 cells. Results All isolates were identified to L. pneumophila including 11 serogroups, among which the main serogroup were LP1, accounting for 54.43%. Thirty-three different sequence types(STs) from five main clonal groups and five singletons were identified, along with 8 different MLVA patterns. Both the lvh and rtx A loci were found in all 79 strains. Thirty isolates showed high intracellular growth ability in J774 cells. Conclusion L. pneumophila is a potential threat to public health, and effective control and prevention strategies are urgently needed.
文摘The effects of epidermal growth factor （EGF） on proliferation of G15 glioma cells and the possible mechanisms were investigated. GFAP and EGFR expression was detected by immunohistochemical method. After the cells were treated with EGF at different concentrations, cell count method was used to determine the proliferation of glioma cells, cell cycle and apoptosis were analyzed by flow cytometry （FCM）, and laser scan confocal microscope （LSCM） was used to measure the cytoplasmic free calcium. The results showed that GFAP was diffusedly expressed in GLI5 cells and EGFR was over-expressed. EGF at doses of ≤ 1 ng/mL could significantly stimulate cell proliferation, cells in phase G0/G1 decreased, and those in phase S increased. EGF at doses of 10 and 100ng/ml could inhibit the cell proliferation significantly, and the apoptosis ratio in high dose of EGF group was higher than in control group. EGF could significantly induce a quick rise of intracellular free calcium, but the peak value of intracellular free calcium activated by high dose of EGF was higher than by low dose of EGF. It was suggested that EGF had a dual effect on gliomas： low dose of EGF could stimulate the cell proliferation of gliomas, but high dose of EGF could induce the cell apoptosis and inhibit the proliferation of gliomas, which might be contributed to the difference of intracellular free calcium.
文摘目的 :探讨细菌脂多糖 (lipopolysaccharide,L PS)对 NIH 3T3细胞增生、胞内游离钙及 c AMP浓度的影响。 方法 :以中性红比色法检测细胞生长 ,酚试剂法检测细胞蛋白质合成 ,并动态检测 L PS对胞内游离钙和 c AMP浓度的影响。 结果 :1微量 L PS可促进细胞生长及蛋白质合成 ;2 L PS作用后 3～ 5 min可使胞内游离钙浓度升高 ,作用 1 m in后使 c AMP浓度升高 ,并保持较高水平。 结论 :胞内游离钙 ([Ca2 + ]i)及 c AMP是 L PS对
