荧光共振能量转移技术在激光共聚焦显微镜中的应用

荧光共振能量转移（FRET）技术广泛用于活细胞中生物大分子构象变化和分子间动态相互作用的实时研究.受体光漂白法和敏化发射测量方法是激光共聚焦显微镜研究FRET的两类常用方法,在实验中应注意FRET荧光对样品选择的要求及FRET技术的局限性等问题.FRET技术作为活细胞研究强有力的工具在生命科学领域具有广阔的应用前景.     

荧光成像技术在神经定位中的研究进展

术中神经定位困难常可增大神经损伤的风险,从而导致患者神经功能障碍。因此,如何在涉及神经的手术(如复发性腮腺肿瘤、前列腺等手术)中准确定位神经成为手术成功的关键因素之一。术中实时定位神经的方法众多,其中荧光成像技术具有高灵敏、易使用、低成本、无辐射的独特优势,因此受到越来越多研究者的关注。该文就荧光成像技术在神经定位中的相关研究成果进行综述。     

The performance of gradient alloy quantum dots in cell labeling

The interest in using quantum dots (QDots) as highly fluorescent and photostable nanoparticles in biomedicine is vastly increasing. One major hurdle that slows down the (pre)clinical translation of QDots is their potential toxicity. Several strategies have been employed to optimize common core–shell QDots, such as the use of gradient alloy (GA)-QDots. These particles no longer have a size-dependent emission wavelength, but the emission rather depends on the chemical composition of the gradient layer. Therefore, particles of identical sizes but with emission maxima spanning the entire visible spectrum can be generated. In the present study, two types of GA-QDots are studied with respect to their cytotoxicity and cellular uptake. A multiparametric cytotoxicity approach reveals concentration-dependent effects on cell viability, oxidative stress, cell morphology and cell functionality (stem cell differentiation and neurite outgrowth), where the particles are very robust against environmentally-induced breakdown. Non-toxic concentrations are defined and compared to common core–shell QDots analyzed under identical conditions. Additionally, this value is translated into a functional value by analyzing the potential of the particles for cell visualization. Interestingly, these particles result in clear endosomal localization, where different particles result in identical intracellular distributions. This is in contrast with CdTe QDots with the same surface coating, which resulted in clearly distinct intracellular distributions as a result of differences in nanoparticle diameter. The GA-QDots are therefore ideal platforms for cell labeling studies given their high brightness, low cytotoxicity and identical sizes, resulting in highly similar intracellular particle distributions which offer a lot of potential for optimizing drug delivery strategies.     

Intraoperative efficiency of fluorescence imaging by Visually Enhanced Lesion Scope (VELscope®) in patients with bisphosphonate related osteonecrosis of the jaw (BRONJ)

ObjectivesThe purpose of this study was to determine the potential of tissue fluorescence imaging by using Visually Enhanced Lesion Scope (VELscope^®) for the detection of osteonecrosis of the jaw induced by bisphosphonates (BRONJ).MethodsWe investigated 20 patients (11 females and 9 males; mean age 74 years, standard deviation ± 6.4 years), over a period of 18 month with the diagnosis of BRONJ in this prospective cohort study. All patients received doxycycline as a fluorescending marker for osseous structures. VELscope^® has been used intraoperatively using the loss of fluorescence to detect presence of osteonecrosis. Osseous biopsies were taken to confirm definite histopathological diagnosis of BRONJ in each case.ResultsDiagnosis of BRONJ was confirmed for every patient. In all patients except one, VELscope^® was sufficient to differentiate between healthy and necrotic bone by visual fluorescence retention (VFR) and visual fluorescence loss (VFL). 19 cases out of a total of 20 showed no signs of recurrence of BRONJ during follow-up (mean 12 months, range 4–18 months).ConclusionVELscope^® examination is a suitable tool to visualize necrotic areas of the bone in patients with bisphosphonate related osteonecrosis of the jaw. Loss of fluorescence in necrotic bone areas is useful intraoperatively as a tool for fluorescence-guided bone resection with relevant clinical interpretation.     

肺癌患者化疗前后血清自体荧光光谱的测定

目的 研究肺癌患者化疗前后血清自体荧光光谱,探讨其临床意义.方法 应用F-4500型荧光分光光度计,激发光波长301nm,测定200～800nm发射光范围内的肺癌患者化疗前后及正常对照组的血清自体荧光光谱.结果 ①肺癌患者化疗前第3、4、6峰的荧光强度及第3峰与第4峰的荧光强度比值I3/I4高于正常对照组(P＜0.01);②肺癌患者化疗后第4、6峰的荧光强度低于化疗前(P＜0.01).结论 血清自体荧光光谱测定可望用于肺癌辅助诊断及疗效观察.     

N-乙酰基转移酶基因多态性与帕金森病相关性研究

目的　探讨N -乙酰基转移酶 (NAT2 )基因多态性与散发性帕金森病 (Parkinson’sdisease ,PD)的关系。方法　应用自动实时荧光Light-Cycler技术 ,分析 88例PD患者和 112例健康人NAT2 4个位点的基因多态性 ,比较PD患者与对照组间频率差异。结果　早发PD组NAT2 6A等位基因频率与对照组比较有显著性差异 (P <0 .0 5 ) ,使患PD的危险度提高了 2 .0 8倍 (P <0 .0 5 ) ,NAT2 5A和NAT2 7A/B等位基因频率与对照组比较无显著性差异 (P >0 .0 5 ) ;晚发PD组NAT2 4个多态位点各等位基因频率与对照组比较无显著性差异 (P >0 .0 5 ) ;未检测到NAT2 14A等位基因。结论　NAT2 6A等位基因可能主要与早发PD的易感性相关 ,并参与了神经毒素的解毒。     

VAMP4 and its cognate SNAREs are required for maintaining the ribbon structure of the Golgi apparatus

Background

The Golgi apparatus is at a crossroads between anterograde and retrograde trafficking. It exhibits a twisted ribbon-like network in the juxtanuclear region of vertebrate cells. Vesicle-associated membrane protein 4 (VAMP4) is a unique v-SNARE expressed exclusively in trans-Golgi networks (TGN), where it regulates retrograde trafficking from the early endosome to the TGN with its cognate SNARE partners Syntaxin 6, Syntaxin 16, and Vti1a.