ABSTRACT
BACKGROUND:The increase in multi-drug resistant bacterial infections has become a major problem in modern healthcare due to the development of bacterial resistance to antibiotics and the development of new antibacterial alternative drug materials is of great importance. OBJECTIVE:To synthesize and perform a series of characterization of a CeO2 nanoenzyme to investigate its biocompatibility and antibacterial properties against Escherichia coli. METHODS:CeO2 nanoenzymes were synthesized using a hydrothermal method.The morphology,product composition,and chemical composition were analyzed using characterization methods such as X-ray diffraction,X-ray photoelectron spectroscopy,Fourier infrared analysis,Raman spectroscopy,scanning electron microscopy,and transmission electron microscopy.The peroxide-mimetic enzyme activity of CeO2 nanoenzymes was characterized using TMB color development assay.The toxic effect of CeO2 nanoenzymes at different concentrations(10,25,and 50 μg/mL)on mouse fibroblast L929 cells was evaluated using the CCK-8 assay.The antibacterial properties of CeO2 nanoenzymes against Escherichia coli under different conditions were evaluated using the plate coating method.Changes in intra-bacterial reactive oxygen species after treatment with different conditions were detected using a reactive oxygen species detection kit. RESULTS AND CONCLUSION:(1)The morphology of the synthesized CeO2 nanoparticles was rod-shaped,with Ce3+ accounting for 29.87%of the total Ce3+/Ce4+ and an average grain size of 7.4 nm.In a slightly acidic environment containing TMB and pH=5.5,CeO2 nanoenzymes mixed with H2O2 showed excellent peroxidase activity,but did not show peroxidase simulated activity at pH=7.4.(2)There was no statistically significant difference in the toxic effects of CeO2 nanoparticles at various mass concentrations on mouse fibroblast L929 cells.(3)In a slightly acidic environment at pH 5.5,Escherichia coli was inhibited to a certain extent in the presence of CeO2 nanoenzyme alone at a concentration of 10 μg/mL,with a decrease in CFU results of about 0.5 log(P＜0.01);in a slightly acidic environment containing 50 μmol/L H2O2,CeO2 nanoenzyme showed excellent antibacterial effects against Escherichia coli,with a decrease in Escherichia coli CFU results of by about 1.5 log(P＜0.001).After CeO2 nanoenzymes interacted with Escherichia coli,the level of reactive oxygen species in Escherichia coli increased(P＜0.05);after CeO2 nanoenzymes interacted with Escherichia coli together with H2O2,the level of reactive oxygen species in Escherichia coli increased significantly(P＜0.001).(4)The results show that the CeO2 nanoenzymes have good biocompatibility,are inherently antibacterial,and can exhibit peroxidase activity in a slightly acidic environment containing low concentrations of H2O2,and generate reactive oxygen species to kill bacteria,thus showing excellent antibacterial effects.
ABSTRACT
Objective:To explore the effect of auricular point pressing pill combined with rhubarb acupoint application on intestinal preparation and prevention of adverse events in colonoscopy.Methods:A total of 220 patients who met the inclusion criteria from May 2019 to February 2020 were randomly divided into 4 groups, 55 in each group. The control group was only given compound polyethylene glycol electrolyte powder. The auricular plaster group was combined with auricular point pressing pill on the basis of the control group. The acupoint sticking group was combined with rhubarb acupoint application on the basis of the control group. The combination group was combined with auricular point pressing pill and rhubarb acupoint application on the basis of the control group. The quality of bowel preparation was evaluated by Boston Bowel Preparation Scale(BBPS), and the adverse events such as perianal discomfort, defecation discomfort, abdominal pain and abdominal distension were observed.Results:After treatment, there was significant difference in BBPS score among the four groups ( F=3.038, P=0.030). The BBPS score in the acupoint sticking group (7.45 ± 1.20 vs. 6.78 ± 1.32) and combination group (7.26 ± 1.11 vs. 6.78 ± 1.32) were significantly higher than those in the control group( P<0.05). After treatment, there were significant differences in abdominal pain and abdominal distension scores among the four groups ( F=2.947, 5.879, P=0.034, 0.001). The scores of perianal discomfort (0.07 ± 0.38 vs. 0.44 ± 1.07), defecation discomfort (0.40 ± 0.81 vs. 0.87 ± 1.32) and abdominal pain (0.93 ± 1.32 vs. 1.69 ± 1.61) in the combination group were significantly lower than those in the control group ( P<0.05), and the abdominal distension score (1.05 ± 1.00 vs. 1.64 ± 0.95) in the acupoint sticking was significantly lower than that of the control group ( P<0.05). Conclusion:Auricular combined with rhubarb powder acupoint application can improve the quality of bowel preparation and reduce intestinal adverse reactions. It can be used with polyethylene glycol electrolyte powder for the intestinal preparation process.
ABSTRACT
Objective To clarify whether the Cosmc gene down-regnhtion in lgA nephropathy (IgAN) patients is resulted from genetic disorders or external suppressions. Methods Forty IgAN patients, 16 non-IgAN glomerulonephritis patients and 21 healthy controls were enrolled in the study. Genomie DNA was extracted and then Cosmc gene was amplified and sequenced. Peripheral B lymphoeytes were isolated and cultured with RPMI-1640 alone or plus lipopolysaecharide (LPS). The Cosmc mRNA expression levels at baseline, after RPMI-1640 culture or RPMI-1640+LPS treatment were measured respectively by real-time RT-PCR. Results (1) Only 2 missense mutations and 2 silent mutations were detected in coding frame region of Cosine gene in 2 IgAN patients. (2) The baseline Cosmc gene expression level was significantly lower in IgAN patients (31% of that in healthy controls) than that in healthy controls. (3) Relative quantification PCR indicated that Cosmc mRNA expression level was significantly increased (219% of baseline) after RPMI-1640 culture, and treatment of LPS could strongly inhibit this effect. (4) The Cosmc gene expression of healthy control was not affected by RPMI-1640 or LPS. Conclusion It is not genetic disorders but external suppression to cause the down-regulation of Cosmc gene mRNA expression in IgAN.