Microtubules and mitosis]

The mitotic chromosome movements are discussed in relation with recent studies on tubulins, their assembly and disassembly, and the associated proteins. The role of contractile proteins in the mitotic spindle is considered, and also that of the calcium regulating protein (CDR) which has been demonstrated recently in the mitotic spindle. The study of more "primitive" mitoses underlines the differences between polar and chromosomal MT. The linear growth of the first, and the sliding movements of MT from opposing poles, explain the growth in length of the mitotic figure and the separation of chromosomes. The complex relations between various types of MT and the possibility of biochemical varieties of tubulins, are discussed.     

Current Reviews in Musculoskeletal Medicine: Current Controversies for Treatment of Meniscus Root Tears

Purpose of ReviewThe role of the meniscus in preserving the biomechanical function of the knee joint has been clearly defined. The hypothesis that meniscus root integrity is a prerequisite for meniscus function is supported by the development of progressive knee osteoarthritis (OA) following meniscus root tears (MRTs) treated either non-operatively or with meniscectomy. Consequently, there has been a resurgence of interest in the diagnosis and treatment of MRTs. This review examines the contemporary literature surrounding the natural history, clinical presentation, evaluation, preferred surgical repair technique and outcomes.Recent FindingsSurgeons must have a high index of suspicion in order to diagnose a MRT because of the nonspecific clinical presentation and difficult visualization on imaging. Compared with medial MRTs that commonly occur in middle age/older patients, lateral meniscus root injuries tend to occur in younger males with lower BMIs, less cartilage degeneration, and with concomitant ligament injury. Subchondral insufficiency fractures of the knee have been found to be associated with both MRTs and following arthroscopic procedures. Meniscus root repair has demonstrated good outcomes, and acute injuries with intact cartilage should be repaired. Cartilage degeneration, BMI, and malalignment are important considerations when choosing surgical candidates. Meniscus centralization has emerged as a viable adjunct strategy aimed at correcting meniscus extrusion.SummaryMeniscus root repair results in a decreased rate of OA and arthroplasty and is economically advantageous when compared with nonoperative treatment and partial meniscectomy. The transtibial pull-through technique with the addition of centralization for the medial meniscus is associated with encouraging early results.     

平贝碱乙的分离和鉴定

本文报道了自东北平贝母(Fritillaria ussuriensis Maxim)中分得一种新的甾体生物碱,经光谱(IR,MS,¹HNMR及¹³CNMR)解析和衍生物制备,推定其结构为5α,17β,22α-cevanine-3 β,6α,12α,14α,16β,20β-hexol,定名为平贝碱乙。     

单克隆抗体博来霉素A6偶联物对白血病细胞特异性结合与内化

抗CCT2单克隆抗体博来霉素A6偶联物可吸附胶体金颗粒(McAb-A6-Au)。电镜观察表明,在4℃,1h,表面有McAb-A6-Au颗粒的CEM细胞最高达78%;在37℃,4h,内化McAb-A6-Au颗粒的CEM细胞高达72%。而抗原性无关的U937细胞仅为14%。并且McAb-A6-Au颗粒能直接穿过细胞膜、核膜进入细胞浆和细胞核。37℃,1h已有10～18%的CEM细胞核内有McAb-A 6-Au颗粒。实验结果提示了单抗与博来霉素A6的偶联物与选择性地结合靶细胞,而且进入细胞速度快、穿透力强,有可能成为治疗白血病药物。