含脐血MSCs 体系扩增后的脐血重建 NOD/SCID小鼠造血的研究

【目的】探讨含人脐血(umbilical cord blood，UCB)来源的间充质干细胞(mesenchymal stem cells，MSCs)联合造血生长因子(hematopoietic growth factors，HGFs)体系扩增后的脐血造血细胞在NOD／SCID小鼠体内植入及重建小鼠造血的能力。【方法】①用含女性胎儿脐血MSCs(UCBMSCs)及HGFs组合的无血清扩增体系体外扩增男性新生儿UCB CD34~+细胞。②收获扩增第6天的UCB细胞，经尾静脉移植给亚致死量照射后的雌性NOD／SCID小鼠。③动态观察移植后小鼠生存情况及外周血象的恢复。④移植后8周，流式细胞仪检测存活小鼠骨髓中人CD45~+、CD45~+CD33~+、CD45~+CD41~+、CD45~+CD3~+和CD45~+CD19~+细胞含量；PCR法检测移植小鼠外周血中人Y染色体表达。【结果】①非扩增组小鼠存活率为60％，扩增组存活率为90％。②动态观察发现：扩增组白细胞和血红蛋白于移植后第20天恢复，PLT于移植后第40天恢复，明显短于非扩增组。③移植后8周，两组小鼠外周血中人Y染色体检测均为阳性，扩增组和非扩增组小鼠骨髓中人CD45+细胞的含量分别为18.5％±8.3％和16.5％±5.7％，差异无统计学意义(P＞0.05)。④移植后8周，扩增组小鼠体内CD45~+CD33~+和CD45~+CD41a~+细胞的百分率均高于非扩增组，但CD45~+CD3~+、CD45~+CD19~+细胞百分比均低于非扩增组。【结论】①含人UCBMSCs体系扩增后的UCB细胞具有NOD／SCID小鼠体内植入并重建小鼠造血的能力，似不具有提高小鼠体内植入率的作用。②扩增后的UCB移植可显著促进移植后小鼠造血恢复，提高小鼠存活率。③扩增后的UCB移植主要促进小鼠髓系及巨核系的植入，但对淋巴系的植入有抑制作用

Determination of the number of ψ(3686) events taken at BESIII

The number of ψ(3686) events collected by the BESIII detector during the 2021 run period is determined to be (2259.3±11.1)×106 by counting inclusive ψ(3686) hadronic events. The uncertainty is systematic and the statistical uncertainty is negligible. Meanwhile, the numbers of ψ(3686) events collected during the 2009 and 2012 run periods are updated to be (107.7±0.6)×106 and (345.4±2.6)×106, respectively. Both numbers are consistent with the previous measurements within one standard deviation. The total number of ψ(3686) events in the three data samples is (2712.4±14.3)×10^