Objective To investigate the expression of serum microRNA(miR)-494 and miR-155 in chil-dren with Enterovirus type 71 hand-foot-mouth disease(EV71-HFMD),and to analyze the clinical significance of serum miR-494 and miR-155 in EV71-HFMD.Methods A total of 145 children with EV71-HFMD treated in this hospital from May 2021 to May 2023 were selected.According to the severity of the disease,they were divided into mild group(n=81)and severe group(n=64).In addition,73 healthy and disease-free children in the hospital were included in the health group.Serum expression levels of miR-494 and miR-155 as well as helper T cell 17(Th17),regulatory T cell(Treg)and Th17/Treg in the three groups were detected and com-pared.Pearson correlation analysis was used to analyze the correlation between the expression levels of serum miR-494,miR-155,Th17 and Treg,as well as Th17/Treg.The clinical data of children with EV71-HFMD were collected,and the factors influencing the severity of EV71-HFMD were analyzed by multivariate Logistic regression model.Results Compared with healthy group,serum miR-494,miR-155,Th17 and Th17/Treg in mild and severe groups were increased,and Treg were decreased(P＜0.05).Compared with mild group,ser-um miR-494,miR-155,Th17 and Th17/Treg in severe group were increased,and Treg was decreased(P＜0.05).Pearson correlation analysis showed that Th17 and Th17/Treg were positively correlated with the ex-pression levels of serum miR-494 and miR-155,while Treg was negatively correlated with the expression lev-els of serum miR-494 and miR-155(P＜0.05).The peak temperature,duration of fever ≥3 d proportion and eruption of isthmus in severe group were higher than those in mild group(P＜0.05).Multivariate Logistic re-gression results showed that the duration of fever ≥3 d,eruption in the isthmus,the high expression level of miR-494 and the high expression level of miR-155 were risk factors for severe EV71-HFMD(P＜0.05).Conclusion Se-rum miR-494 and miR-155 are abnormally elevated in children with EV71-HFMD,and the changes in their levels are closely related to Th17/Treg imbalance.Increased expression levels of serum miR-494 and miR-155 are risk factors for severe EV71-HFMD.

The aims of this research were to isolate a Aspergillus niger strain with higher beta-glucosidase activity. We utilized the beta-glucosidase producing strain Aspergillus niger CGMCC 3.316 as the original strain to first obtain a mutant 3-3M through ultraviolet irradiation. Then we studied the conditions of protoplast release and regeneration for strain 3-3M. We treated the protoplasts of strain 3-3M via ultraviolet irradiation and obtained another isolated mutant 60B-3D. The strain 60B-3D showed much higher beta-glucosidase production than the original strain and 3-3M strain. The beta-glucosidase activity of strain 60B-3D was 23.4 IU/mL, with an improvement of 39% compared with the original strain, and 23% compared with strain 3-3M. We also studied the fermentation process of strain 60B-3D, and compared it with the original strain and strain 3-3M. We found the strain 60B-3D exhibited an improvement in xylanase production. The comparison results also showed that the strain 60B-3D secreted more protein. These results were beneficial for producing beta-glucosidase through this productive mutant.
Amino Acid Sequence ; Aspergillus niger ; enzymology ; genetics ; Endo-1,4-beta Xylanases ; biosynthesis ; Fermentation ; Molecular Sequence Data ; Mutagenesis ; Mutation ; Protoplasts ; enzymology ; beta-Glucosidase ; biosynthesis