Objective:To establish a mice model that is more in line with the human immunocompromised state,and to inves-tigate the regulatory effect of Rosa laevigata Michx.,probiotics and their combination on their immune function.Methods:Immunosup-pressive model of mice was established by using cyclophosphamide with different dosage,time and end point,and compared with im-munosuppressive model induced by hydrocortisone and cyclosporine A,immunosuppressive model of mice was established by injecting 25 mg/kg cyclophosphamide 7 times every other day,without recovery period;changes in the proportion of lymphocytes in spleen(CD4+T cells,CD8+T cells,CD19+B cells)were analyzed by flow cytometry;qRT-PCR was used to detect expression levels of inflam-matory factors(IL-1β and IL-6)mRNA in spleen.Results:After continuous injection of 80 mg/kg cyclophosphamide for 3 days,the thymus was atrophied,the spleen was significantly swelling,proportion of immune cells CD4+T cells,CD8+T cells and CD19+B cells in spleen were significantly decreased,while mRNA expressions of IL-1β and IL-6 were up-regulated.After 7 injections of 25 mg/kg cyclophosphamide every other day,the thymus and the spleen were significantly atrophied,proportion of CD4+T cells and CD8+T cells in spleen showed an increasing trend,and mRNA expressions of IL-1β and IL-6 were up-regulated;after 1 week or 2 weeks recovery period from cyclophosphamide injection,weight and index of immune organs,proportion of spleen lymphocytes and mRNA expres-sions of inflammatory cytokines in spleen were significantly reversed;Rosa laevigata Michx.combined with probiotics could signifi-cantly reverse the up-regulation of CD4+T cells and inflammatory factor IL-1β caused by cyclophosphamide.Conclusion:In this study,an immunocompromised mice model has been established with 7 injections of 25 mg/kg cyclophosphamide every other day and without recovery period.And a certain positive immunomodulatory effect of the combination of Rosa laevigata Michx.and probiotics has been found.

Objective To understand and analyze the epidemiological and pathogenic characteristics of foodborne diseases in Changzhou in the past five years, so as to provide evidence for prevention and control measures. Methods All foodborne disease surveillance information reported by Changzhou foodborne disease sentinel hospital from 2016 to 2020 was collected through the ^“Foodborne Disease Surveillance and Reporting System^”. The distribution of reported cases and etiological results was described, and the possible factors affecting pathogen detection results were analyzed. Results A total of 14 931 cases of foodborne diseases were reported, mainly distributed in summer and autumn, and peaked in July and August. The age group of reported cases was 25-34 years old, and the occupations were mainly workers, and farmers and migrant workers, accounting for 23.2% and 36.9%, respectively. Among the reported cases of 3 120 anal swabs were collected and tested for etiology , of which 291 specimens were positive, with a positive detection rate of 9.32%. Among the 291 positive results of 118 cases of norovirus were detected, with a detection rate of 6.03% . 66 cases of salmonella were detected, with a detection rate of 2.12% . 25 cases of vibrio parahaemolyticus were detected, with a detection rate of 0.80% . 7 cases of diarrhea-causing Escherichia coli was detected, with a detection rate of 0.22% ; and 5 cases of shigella was detected, with a detection rate of 0.16% . Single factor analysis of the results of pathogen detection showed that there were no statistical differences in the distribution of positive pathogen detection rate between males and females, and between different suspicious exposed foods (all P>0.05). There were statistical differences in different age groups, occupations, seasons and eating places (all P<0.05). Multivariate Logistic regression analysis showed that age and season were correlated with the detection rates of pathogenic microorganisms (all P<0.05) , and age was negatively correlated with the positive rate of pathogenic microorganisms (OR=0.863). The detection rates in the first and fourth quarters were higher than those in the second and third quarters. Conclusion Summer and autumn are the seasons with high incidence of foodborne diseases in Changzhou. Norovirus is the main pathogen. Age and season are closely related to the detection results of pathogenic microorganisms. Comprehensive prevention and control measures should be implemented for key population in summer and autumn to reduce the occurrence and outbreak of foodborne diseases.

Objective: To observe and compare the effects of two standards on the overweight trend in urban Shanghai infants and young children. Methods: A cluster randomized controlled trial was conducted in 19 communities in two districts of Shanghai, and the subjects (n=15 019) were divided into S-group and W-group by sealed envelope randomization. The subjects were newborns born between November 2013 and December 2014. The 2005 Shanghai growth standard was applied in the S-group and the 2006 WHO growth standard was used in the W-group. At each follow-up time point age of 1, 2, 4, 6, 9, 12 and 18 months, the outpatient physician assessed the length and weight of the infants according to the standard adopted by each group and provided feeding guidance. The weight-for-age Z scores (WAZ), length-for-age Z scores (LAZ) and weight-for-length Z scores (WLZ) were calculated according to the WHO standard. Weight, length, WAZ, LAZ, WLZ and overweight ratio (WLZ≥2) were compared between the two groups using t test, Wilcoxon test and χ² test. Results: A total of 6 509 infants (3 391 were boys, 3 118 were girls) were in the W-group, and 8 510 infants (4 374 were boys, 4 136 were girls) were in the S-group. Among the boys, the weight values at the age of 4, 6, 9, 12, 18 months in the W-group were all lower than those in the S-group ((7.5±0.8) vs. (7.7±0.8) kg, (8.6±0.8) vs. (8.7±0.8) kg, (9.6±0.9) vs. (9.7±0.9) kg, (10.4±1.0) vs. (10.5±1.0) kg, (11.5±1.1) vs.(11.7±1.1) kg; t=4.329, 2.422, 3.739, 2.451, 2.736; P<0.01, 0.015,<0.01, 0.014, 0.009). The length had no significant difference between two groups at all months of age(all P>0.05). The overweight ratio in the W-group was lower than that in the S-group at the age of 9, 12, 18 months(3.3% (71/2 170) vs. 4.9% (143/2 927), 2.5% (51/2 037) vs. 4.5% (126/2 818), 0.8% (7/832) vs. 3.1% (39/1 266); χ²=6.520, 14.209, 12.350; P=0.011,<0.01,<0.01).Among the girls, except at the age of 2 months (W-group (5.6±0.6) vs. S-group (5.7±0.6), t=2.935, P=0.003), weight values had no significant difference between the two groups at other age months (all P>0.05).The length in the W-group was higher than that in the S-group at 12 and 18 months of age ((75.6±2.4) vs.(75.5±2.3)cm, (82.4±2.9) vs.(82.2±2.7) cm; t=2.351, 2.197; P=0.019, 0.028). The ratio of overweight in the W-group was lower than that of S-group at the age of 12 and 18 months (1.8% (33/1 871) vs.3.0% (80/2 658), 0.6% (5/790) vs.1.7% (20/1 178); χ²=6.764,4.276; P=0.009, 0.039). Conclusions The application of WHO growth standard can help to reduce the weight gain rate of boys, promote the linear growth of girls, and thus alleviate the overweight trend of infants within 18 months. It suggested that 2006 WHO growth standard should be applied to infants within 1 year of age in Shanghai.