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Objective To determine whether regulatory T cells (Tregs) are involved in sevoflurane preconditioning-induced brain protection against cerebral ischemia/reperfusion injury. Methods C57BL/6 mice were preconditioned with sevoflurane and then subjected to the middle cerebral artery occlusion modeling. The brain infarct volume and neurological score were assessed at 48 hours after cerebral reperfusion. Meanwhile, the proportion of Tregs in the spleen was analyzed by flow cytometry. Then, CD25 neutralizing antibody was administrated by intraperitoneal injection, following with the analysis of cerebral ischemia/reperfusion injury and the proportion of Tregs in the spleen after sevoflurane preconditioning. Results Compared with a control group, sevoflurane preconditioning markedly mitigated the cerebral ischemia/reperfusion injury in the mice including the infarct volume and neurological score. In the meantime, sevoflurane preconditioning significantly increased the proportion of Tregs in the spleen at 48 hours after cerebral reperfusion. Compared with the isotype antibody group, the CD25 neutralizing antibody reversed the increase of Tregs induced by sevoflurane preconditioning at 48 hours after reperfusion, which was also associated with the reversal of sevoflurane preconditioning-induced protectetion against cerebral ischemia/reperfusion injury. Conclusion Tregs are involved in sevoflurane preconditioning-induced cerebral protection against ischemia/reperfusion injury.

Objective: To investigate the cerebral infarct volume 24 hours after transient middle cerebral artery occlusion (tMCAO) and the proportion of CD4⁺;CD25⁺;Foxp3⁺; regulatory T cells (Tregs) in splenocytes in diverse periods after all-trans retinoic acid (ATRA) treatment in mice, so as to explore whether ATRA have the protection against cerebral ischemia damage in mice through intervening Treg differentiation., Methods: Sixty male Kunming mice were randomly divided into two groups, i.e. pretreatment (n=40) and post-treatment (n=20) groups. Each group was against divided into two subgroups, i.e. tMCAO combined with ATRA treatment group, tMCAO combined with DMSO control group. Pretreatment groups: mice were treated intraperitoneally with ATRA (10 mg/kg) dissolved in 100 mL/L DMSO or equivalent volume of 100 mL/L DMSO daily for 7 days (n=20/group). Ten mice in each group were sacrificed and the proportion of Tregs in splenocytes was analyzed by flow cytometry (FCM) after 7-day pretreatment. The other 10 mice in each group were subjected to tMCAO by modified monofilament method. Neurologic deficit score (NDS) was recorded and the infarct volume was assessed by 2, 3, 5-triphenyltetrazolium chloride(TTC) staining 24 hours after tMCAO. The mice in post-treatment groups were treated intraperitoneally with ATRA (10 mg/kg) or equivalent volume of 100 mL/L DMSO immediately after the reperfusion of tMCAO modeling (n=10/group). NDS and infarct volume were assessed and the proportion of Tregs in splenocytes was analyzed 24 hours after tMCAO., Results: ATRA pretreatment for 7 days failed to improve neurologic function deficit (P>0.05) and to reduce the cerebral infarct volume (P>0.05) 24 hours after tMCAO in mice. ATRA post-treatment could markedly improve neurologic function (P<0.05) and reduce the cerebral infarct volume (P<0.05) 24 hours after tMCAO. However, neither ATRA pretreatment nor post-treatment had effect on the proportion of Tregs in the splenocytes of mice (P>0.05)., Conclusion: ATRA administered before tMCAO for 7 days failed to protect brain against ischemic damage. ATRA administered immediately following tMCAO induced cerebral protective effect 24 hours after tMCAO. The results suggest that Tregs change is not involved in the neuroprotection mechanism of ATRA.

Objective: In order to systematically investigate the cry gene resources from Bacillus thuringiensis (Bt) in different ecological regions in Sichuan Basin and further clone novel cry genes., Methods: We used the methods of microscopic and scanning electron microscopic observation, PCR-restriction fragment length polymorphism (PCR-RFLP) analysis, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and test of insecticidal activities to research Bt strains collected in this basin., Results: We screened 791 Bt isolates from 2650 soil samples, and found cryl, cry2, cry3, cry4/10, cry9, cry30, and cry40-type genes in this basin. Strains containing cryl genes were the most abundant in our collection (66%), and 21 different cry1-type gene combinations were found. Furthermore, several novel holotype cry genes were found and the full-length sequences of 3 novel cry genes were designated as cry54Aa1, cry30Fa1, and cry30 Ga1 by B. thuringiensis Pesticidal Crystal Protein Nomenclature Committee. The results of insecticidal activities showed that Sichuan Basin harbored Bt isolates with insecticidal activities. SDS-PAGE assay of 80 strains without PCR products indicated that these strains may harbor potentially novel cry proteins gene., Conclusion: The diversity and particularity of cry gene resources in Sichuan Basin have important meanings in theories and practices.