间充质干细胞来源的胞外体对阿尔茨海默病的调控作用

阿尔茨海默病(Alzheimer’s disease，AD)为最常见的老年痴呆性疾病之一，约占所有痴呆患者的75%。 其病理特征为具有很强神经毒性作用的β-淀粉样蛋白(β-amyloid，Aβ)沉积在脑组织，并且许多神经元内tau 蛋白的过 度磷酸化形成神经纤维缠结(neurofibrillary tangles，NFT)，导致大量神经元坏死，大脑功能调控紊乱，从而出现严重 的认知功能障碍。间充质干细胞(mesenchymal stem cells，MSCs)是一种成体干细胞，能产生大量多囊泡体分泌至胞外 形成胞外体。胞外体大小不等，直径为30~150 nm，可跨越血脑屏障，携带大量小分子miRNA和蛋白质分子到达脑组 织内发挥作用。MSCs来源的胞外体对AD具有调控作用。

Arthroscopic meniscus plasty of the discoid cartilage of the knee joint

From 1989 to 1998, arthroscopic discoid lateral meniscus plasty was performed in twenty eight patients(thirty one joints), and evaluated in a short follow up term. The mean age was 21.5(6～42) years. The average follow up period lasted 8.4 months. The results were assessed by the Ikeuchi’s grading, 87.1% joints had excellent and good results, including all incomplete types and 77.8% complete type of discoid meniscus. It is suggested that arthroscopic meniscus plasty plays an important role in the treatment of discoid meniscus of knee, and should be performed possibly as soon as the disease was diagnosed by arthroscopic examination