Aim To develop the in vitro and in vivo models induced by shrimp tropomyosin( ST) and mono-clonal tropomyosin-specific murine IgE antibody ( anti-ST-IgE mAb) . Methods ST was purified from Metap-enaeusensis by an isoelectric precipitation method. The anti-ST-IgE mAb was obtained from hybridomas. After RBL-2 H3 cells were sensitized with anti-ST-IgE mAb and challenged with ST,β-hexosaminidase release was determined. Passive systemic anaphylaxis ( PSA ) was induced in mice and the rectal temperature was recor-ded after ST challenge within 30 min by a thermal probe. Results A significant increase ofβ-hexosamin-idase was observed in sensitized cells after ST chal-lenge. The average temperature drop after ST challenge was 1. 44℃ in PSA mice within 30 min. Conclusion The in vitro and in vivo models induced by ST and anti-ST-IgE mAb are established as an improvement of pres-ent models of type Ⅰ allergy.

Objective:To develop murine models of Th2 response induced by shrimp tropomyosin (ST). Methods:Mice were sensitized with ST for 6 weeks. The serum antigen-special IgE (sIgE),total IgE and sIgG level,Th1/Th2 cytokines production were measured by ELISA. The basophil activation in mice was measured by flow cytometry. Results:The intraperitoneal sensitization with ST for 6 weeks induced significant increase of serum sIgE,total IgE and sIgG (sIgG1,sIgG2a and sIgG2b) level in mice. Th2 cell response was induced and cytokines (IL-4,IL-5,IL-10 and IL-13) production increased in splenocytes stimulated by ST,while Th1 cytokine (IFN-γ) production decreased. As the markers of basophil activation,CD200R and CD41 expression also increased in response to ST. Conclusion:The Th2 response is dominant in ST-induced anaphylaxis in mice.

Objective:To explore the role of WeChat platform combined with flipped classroom in improving the working ability of resident doctors in the fever clinic.Methods:A total of 118 resident doctors who rotated in the fever clinic of department of emergency medicine were selected as the study subjects, and they were randomized into experimental group and control group, with 59 people in each group. The experimental group used WeChat platform and flipped classroom teaching, and the control group used traditional teaching. The results of theory assessment, operation performance and questionnaire survey were compared between the two groups. SPSS 26.0 statistical software was used for t test and chi-square test. Results:There was no significant difference in theoretical test scores between the experimental group and the control group ( P>0.05). The experimental group scored (91.61±3.01) points and the control group scored (84.52±4.02) points in operational assessment, with significant differences ( t=-10.85, P<0.05). The results of the satisfaction survey showed that there was no significant difference in teaching time distribution between the two groups, and the experimental group was better than the control group in any other aspects. Conclusion:The use of WeChat platform combined with flipped classroom during the COVID-19 epidemic can improve the level of operational skills of the resident doctors to wear or take off the protective clothing and collect nasopharyngeal swabs, help residents to avoid the infections, and improve the level of daily diagnosis and treatment of fever clinic.

Objective:To investigate the normal range of exhaled nitric oxide (FeNO) in 6-18-year-old children in China, so as to provide a data base for the establishment of FeNO standards for Chinese children.Methods:A multi-center study was conducted on 5 949 children aged 6-18 (3 101 males and 2 848 females) in 16 pro-vinces of 7 administrative districts in China.According to the technical standard recommended by American Thoracic Society/European Respiratory Association, FeNO was measured, and the relationship of FeNO with the sex, age, height, weight, body mass index and region was discussed.Results:The geometric mean FeNO value of Chinese children aged 6-18 was 14.1 ppb, and its 95% confidence interval (skewness distribution) was 1.0-38.2 ppb.The geometric mean FeNO values of children aged 6-11 and 12-18 were 13.1 ppb and 15.7 ppb, respectively, and their 95% confidence intervals (skewness distribution) were 1.0-38.1 ppb and 2.0-38.2 ppb.For children at and under 11 years old, FeNO decreased with age, with a mean decline of 1 ppb per year.The multiple linear regression results suggested that there was a significant correlation between FeNO and age for children aged 6-11, and FeNO of children aged 12-18 was significantly correlated with the gender, height, and region(all P<0.01). Conclusions:FeNO values of Chinese children and adolescents in this study are higher than those obtained by the previous study conducted from 2010 to 2012.For children aged 12-18, 16 ppb is recommended as the clinical cut-off point.For children at or under 11 years old, the influence of age on FeNO should be considered, and the cut-off point of FeNO decreases by 1 ppb as the age is reduced by one year.