SERCA regulates collective cell migration by maintaining cytoplasmic Ca~(2+) homeostasis

<正>Characterized by multicellular migratory behavior and cooperative ability,collective cell migration plays critical roles in developmental,physiological and pathological processes,such as organogenesis,wound healing and tumor metastasis (Friedl and Gilmour,2009).Molecular features of collective cell migration including collective polarization,coordinated cytoskeletal activity,and guidance signaling have been recently investigated in a variety of in vivo and in vitro model systems (Scarpa and Mayor,2016),but many other aspects of regulatory mechanisms remain unexplored.     

Rho‐associated coiled‐coil kinase 1 activation mediates amyloid precursor protein site‐specific Ser655 phosphorylation and triggers amyloid pathology

Rho‐associated coiled‐coil kinase 1 (ROCK1) is proposed to be implicated in Aβ suppression; however, the role for ROCK1 in amyloidogenic metabolism of amyloid precursor protein (APP) to produce Aβ was unknown. In the present study, we showed that ROCK1 kinase activity and its APP binding were enhanced in AD brain, resulting in increased β‐secretase cleavage of APP. Furthermore, we firstly confirmed that APP served as a substrate for ROCK1 and its major phosphorylation site was located at Ser655. The increased level of APP Ser655 phosphorylation was observed in the brain of APP/PS1 mice and AD patients compared to controls. Moreover, blockade of APP Ser655 phosphorylation, or inhibition of ROCK1 activity with either shRNA knockdown or Y‐27632, ameliorated amyloid pathology and improved learning and memory in APP/PS1 mice. These findings suggest that activated ROCK1 targets APP Ser655 phosphorylation, which promotes amyloid processing and pathology. Inhibition of ROCK1 could be a potential therapeutic approach for AD.     

Determination of oxytetracycline hydrochloride in milk and egg white samples using Ru(bipy)32+–Ce(SO4)2 chemiluminescence

A novel, rapid and sensitive chemiluminescence (CL) method for the determination of oxytetracycline hydrochloride (OTCH) is described in this paper. The presented method was based on the fact that OTCH could immensely enhance the CL of the reaction of cerium sulfate and tris(2,2‐bipyridyl) ruthenium (II) in acidic medium. Under optimal experimental conditions, CL intensity was favorably linear for OTCH in the range 5.0 × 10^?7 to 5.0 × 10^?5 g/ml, with a detection limit of 1.5 × 10^?7 g/ml (S/N = 3). The relative standard detection was 4.76% for 5.0 × 10^?6 g/ml (n = 11). This method was successfully applied to the analysis of OTCH in milk and egg white samples. According to the results of the kinetic curves for OTCH in the Ru(bipy)₃²⁺–Ce(SO₄)₂ CL system, together with CL and ultraviolet (UV)–visible spectra, the possible mechanism of the CL reaction is discussed briefly.     

精细化管理在病理学技术质量控制中的应用

精准医疗是近年来医学的发展方向,精准医疗依赖于精准的诊断,而精准诊断则需要高质量病理学切片技术作为支撑。武汉大学人民医院病理科将精细化管理理念融入病理学技术质控和管理工作的每一环节,通过采用不同颜色包埋框对组织分类、时间梯度法调控出片时间、根据人员资质及医疗风险对病理学技术人员分级授权、专人专机负责制、信息化管理、PDCA循环法持续改进等管理措施为精准病理学诊断打好基础,大大提高了诊断准确率和及时率,为临床病理学诊断提供了可靠的技术支撑。     

Using focus ion beam to prepare crystal lamella for electron diffraction

Electron diffraction provides a powerful tool to solve the structures of small protein crystals. However, strong interactions between the electrons and the materials limit the application of the electron crystallographic method on large protein crystals with micrometer or larger sizes. Here, we used the focused ion beam (FIB) equipped on the scanning electron microscope (SEM) to mill a large crystal to thin lamella. The influences of the milling on the crystal lamella were observed and investigated, including radiation damage on the crystal surface during the FIB imaging, deformation of the thin crystal lamella, and variation in the diffraction intensities under electron radiation. These observations provide important information to optimize the FIB milling, and hence is important to obtain high-quality crystal samples for routine structure determination of protein crystals using the electron cryo-microscope.     

人中鼻甲来源嗅鞘细胞培养与鉴定的初步研究

目的探索一种从人中鼻甲分离培养嗅鞘细胞的方法并鉴定所获得的细胞。 方法通过手术获取人中鼻甲黏膜组织,随后进行两步消化并剥离黏膜上皮组织,得到体积较小的组织块,再进行组织块原代（传代）培养并加压筛选,最终得到双极或多极样细胞并对获得的细胞进行免疫荧光鉴定。上皮样细胞比例、S100β和p75阳性细胞比例用 ±s表示,组间比较采用独立样本t检验。 结果将不剥离上皮层与剥离上皮层培养的原代细胞中上皮样细胞的比例进行对比,发现上皮层组上皮样细胞比例为（92.23±3.93）%高于剥离上皮层组上皮样细胞的比例（77.63±2.97）%,差异具有统计学意义（t = 5.129,P = 0.007）。采用剥离上皮层法培养原代细胞,经过加压筛选的细胞呈现双极或多极样,符合嗅鞘细胞形态学特点。免疫荧光染色发现,S100β阳性细胞占总细胞量的（8.1±1.7）%,而p75阳性细胞占总细胞量的5%以下,达到国内外研究同等水平。 结论通过使用两步消化法和加压筛选联合的方法从人中鼻甲粘膜组织中成功获得了人中鼻甲嗅鞘细胞,相比较传统方法,细胞分离培养周期明显缩短。