0.05),the inhibitory rates in the other groups were increased compared with control group(P0.05),the expressions of COX-2 and VEGF in MCF-7 cells in the other groups were lower than that in negative control group(P

Objective: To understand the results of tuberculin skin test (PPD) in preschool children after the vaccination of BCG, and to analyze the effect of BCG vaccination on latent tuberculosis infection in children. Methods: From January to November 2018, a total of 1 359 preschool children from 14 kindergartens in 8 districts and cities of Jiangsu Province were selected for tuberculin test(PPD), and chest X-ray examination was performed on children with strong PPD results. Results: The positive rate of PPD in preschool children in Jiangsu Province was 23.33%, of which strong positive and moderate positive (PPD≥10 mm) were totaled 6.47%. There were 149 boys (21.29%) with PPD positive reactions and 168 girls(25.50%) with PPD positive reactions, and differences of PPD positive reactions with different genders were of no statistical significance (χ2=3.36, P>0.05) And there were 201 children (25.35%) with PPD positive reactions in northern Jiangsu, 116 children (20.50%) with PPD positive reactions in southern Jiangsu. There were significant differences in the results of PPD positive and negative reactions between different regions(χ2=4.35, P<0.05). There was 1 case of PPD positive reactions among 3-year-old children(0.71%), 19 cases among 4-year-old children(3.89%), 31 cases among 5-year-old children(8.96%), and 37 cases among 6-year-old children(9.63%), and the differences of PPD positive reactions of different age groups were of statistical significance(χ2=21.69, P<0.01). Conclusion The positive rate of PPD in preschool children in Jiangsu Province is very low, indicating that PPD can be used as a detection method for latent infection in children. The overall positive rate of PPD in preschool children in Jiangsu Province is also low, and appropriate measures should be taken to protect susceptible children and effectively prevent and control childhood tuberculosis.