ABSTRACT
Objective@#To evaluate the immunity and influencing factors of diphtheria among preschool children in Shenzhen,to provide reference for effective monitoring of diphtheria IgG antibody level in preschool children.@*Methods@#Serum samples were collected from 296 preschool children aged 4-6 who were recruited in Shenzhen. The diphtheria antibody titer in serum was determined by enzyme linked immunosorbent assay, and the effect of different immumuzation schedule including types of vaccine and vaccination timing, on the geometric mean concentration (GMC) of diphtheria IgG antibody and antibody positive rate were analyzed.@*Results@#The GMC of diphtheria IgG antibody was 0.71 IU/mL, and the positive conversion rate was 33.1%. There were significant differences in antibody GMC and antibody positive conversion rate of diphtheria in different age groups( F/χ 2=11.77, 27.45, P < 0.01 ). The GMC and antibody positive conversion rate showed significant differences by diphtheria antibodies, vaccine types and end dose vaccination intervals( F=49.53, 12.95，11.61, P <0.01). There were statistically significant differences in the positive conversion rate of diphtheria antibodies in children with different types of diphtheria antibodies, vaccine types of diphtheria antibodies, and diphtheria antibodies at the time interval of final vaccination (Fisher exact probability method, P <0.01).@*Conclusion@#The overall positive conversion rate of diphtheria antibody in preschool children in Shenzhen is high. Timely completion of full diphtheria vaccination can improve the antibody level and plays a better role in protecting preschool children.
ABSTRACT
Thymosin alpha 1 (Tα1) has been shown to have beneficial effects on numerous immune system parameters, but little is known about the effects of Tα1 on patients with gastric carcinoma. The objective of this study was to determine the effect of Tα1 on subpopulations of Th1, Th2, Th17, and regulatory T cells (Tregs) in vitro, and to evaluate its efficacy as an immunoregulatory factor in patients with gastric carcinoma. We compared the effect of Tα1 on the frequency of CD4+ and CD8+ T cells, especially the CD4+CD25+Foxp3+ Tregs in peripheral blood mononuclear cells (PBMCs) from gastric carcinoma patients (N = 35) and healthy donors (N = 22). We also analyzed the changes in the proliferation of PBMCs in response to treatment with Tα1, and examined the production of Th1, Th2, and Th17 cytokines by PBMCs and tumor-infiltrating lymphocytes. The treatment of PBMCs from gastric cancer patients, with Tα1 (50 µg/mL) alone increased the percentage of CD4+CD25+Foxp3+ (suppressive antitumor-specific Tregs) from 1.68 ± 0.697 to 2.19 ± 0.795 percent (P < 0.05). Our results indicate that Tα1 increases the percentage of Tregs and IL-1β, TNF-α, and IL-6 in vitro.