Objective:TO explore the effectiveness of splenic tissue autotransplantation in restoring host defense. Methods: Rabbits were divided into three groups,Sham Operation(SO), Splenic Autotransplantation(SA)and Total Splenectomy(TS), and dynamic changes in histology and immunology were observed for over 24 weeks. Results: Histologic study shows that the white pulps were poorly developed and central arterioles disappeared in the regenerated splenic tissue. The weight of regenerated spleens recovered six months later in SA was 11% of that in SO, and was significantly reduced comparing with the implanted weight( P ＜0.05). Tere were no significant difference in the number of T lymphocytes and the levels of serum lysozyme among the three groups. A poor antibody response by the rabbits of SA and TS as compared to those of SO was noted after the primary intravenous administration with sheep red blood cells. After the challenge with type 3 pneumococci intravenously, pneumococcal clearance from bloodstream in SA did not differ significantly from that in TS,but was marKedly delayed compared with that in SO(P＜0.01). Conclusion: The results indicate that the low quantity and poor quality of the regenerated spleens may contribute to the inferior immunoprotective ability of 1/3 splenic autotransplantation. Therefore, it implies that the regenerated spleens can not fully compensate the original one in im-munology, especially, host resistance to infection.

Objective: To explore the relationship between cardiorespiratory fitness and executive function in Chinese adolescents, so as to provide a reference for promoting the overall development of Chinese adolescents physical and mental health. Methods: From September to December 2022, a total of 5 018 adolescents aged 13 to 18 years from Shanghai, Suzhou, Taiyuan, Wuyuan, Xingyi, and Urumqi were selected by stratified cluster sampling method to assess cardiorespiratory fitness and executive function. Pearson s correlation and linear hierarchical regression were performed to analyze the relationship between cardiorespiratory fitness and executive functions. Results: Among the sample of adolescents, maximal oxygen consumption (VO 2max ) was negatively correlated with the refreshing(1-back, 2-back) and conversion executive function responses ( r=-0.07, -0.12, -0.12, P <0.01). Linear regression analysis showed that VO 2max was negatively correlated with the reaction times of the refreshing(1-back, 2-back) and conversion functions ( B=-2.99, -6.44, -1.69, P <0.01). Conclusions Higher cardiorespiratory fitness among adolescents is associated with better performance in executive function. Teenagers should strengthen high intensity cardiopulmonary endurance exercise to promote the improvement of executive function.