基质辅助激光解析电离飞行时间质谱检测耐甲氧西林金黄色葡萄球菌δ-毒素的应用

目的 本研究采用基质辅助激光解析电离飞行时间质谱(MALDI-TOF MS)检测δ-毒素,评估其在耐甲氧西林金黄色葡萄球菌(MRSA)的分型和毒力表达中的作用。方法 使用Bruker microflex MALDI-TOF仪器,采集2000~20000Da质量范围内,以正线性模式采集图谱,使用仪器配套的MALDI Biotyper 2.0软件分析MRSA菌株的原始图谱,产生的峰列表直接使用flexAnalysis、clinProTools3.0软件分析。结果 本研究中共检测83株MRSA,共有39(47.0%)株MRSA检出(3005±5)m/z信号峰,其中HA-MRSA 19(22.9%)株,CA-MRSA 20(26.5%)株,P=0.766,两者之间无显著性差异;33(39.8%)株MRSA检出(3035±5)m/z信号峰,其中HA-MRSA 9 (10.8%)株,CA-MRSA 24(28.9%)株,P=0.003,两者之间有显著性差异;11(13.%)株MRSA既未检出(3005±5)m/z信号峰也未检出(3035±5)m/z信号峰,全部为HA-MRSA菌株。spa分型中检出(3005±5)m/z信号峰,15(18.1%)株为t062型,8株为t015(9.6%)型,4株为t030(4.8%)株,P=0,有显著性差异;检出(3035±5)m/z信号峰,31(37.3%)株为t437型,2(2.4%)株t8660型,P=0,有显著性差异;(3035±5)m/z作为spa t437型特征信号ROC曲线下面积0.89,P=0。11株未检出δ-毒素,6株分离自骨关节标本,3株分离自呼吸道标本,1株分离自慢性溃疡的分泌物标本,1株分离自血液;在血平板的菌落特征,6株MRSA菌落形态发生改变,5株菌落形态正常。结论 MALDI-TOF MS使用常规方法即可快速检测MRSA的δ-毒素,其质谱峰为(3005±5)m/z和(3035±5)m/z两种;(3035±5)m/z是δ-毒素的同基因变异体(HldG10S)的质谱峰,该峰可快速鉴别spa t437型;不产生δ-毒素的菌株是agr调控系统失调的表现,与慢性感染、小菌落形成、无明显β-溶血有关。     

Quantitative Prediction of Oral Bioavailability of a Lipophilic Antineoplastic Drug Bexarotene Administered in Lipidic Formulation Using a Combined In Vitro Lipolysis/Microsomal Metabolism Approach

For performance assessment of the lipid-based drug delivery systems (LBDDSs), in vitro lipolysis is commonly applied because traditional dissolution tests do not reflect the complicated in vivo micellar formation and solubilization processes. Much of previous research on in vitro lipolysis has mostly focused on rank-ordering formulations for their predicted performances. In this study, we have incorporated in vitro lipolysis with microsomal stability to quantitatively predict the oral bioavailability of a lipophilic antineoplastic drug bexarotene (BEX) administered in LBDDS. Two types of LBDDS were applied: lipid solution and lipid suspension. The predicted oral bioavailability values of BEX from linking in vitro lipolysis with microsomal stability for lipid solution and lipid suspension were 34.2 ± 1.6% and 36.2 ± 2.6%, respectively, whereas the in vivo oral bioavailability of BEX was tested as 31.5 ± 13.4% and 31.4 ± 5.2%, respectively. The predicted oral bioavailability corresponded well with the oral bioavailability for both formulations, demonstrating that the combination of in vitro lipolysis and microsomal stability can quantitatively predict oral bioavailability of BEX. In vivo intestinal lymphatic uptake was also assessed for the formulations and resulted in <1% of the dose, which confirmed that liver microsomal stability was necessary for correct prediction of the bioavailability.     

Multi-centre evaluation of mass spectrometric identification of anaerobic bacteria using the VITEK® MS system

Accurate and timely identification of anaerobic bacteria is critical to successful treatment. Classic phenotypic methods for identification require long turnaround times and can exhibit poor species level identification. Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) is an identification method that can provide rapid identification of anaerobes. We present a multi-centre study assessing the clinical performance of the VITEK^® MS in the identification of anaerobic bacteria. Five different test sites analysed a collection of 651 unique anaerobic isolates comprising 11 different genera. Multiple species were included for several of the genera. Briefly, anaerobic isolates were applied directly to a well of a target plate. Matrix solution (α-cyano-4-hydroxycinnamic acid) was added and allowed to dry. Mass spectra results were generated with the VITEK^® MS, and the comparative spectral analysis and organism identification were determined using the VITEK^® MS database 2.0. Results were confirmed by 16S rRNA gene sequencing. Of the 651 isolates analysed, 91.2% (594/651) exhibited the correct species identification. An additional eight isolates were correctly identified to genus level, raising the rate of identification to 92.5%. Genus-level identification consisted of Actinomyces, Bacteroides and Prevotella species. Fusobacterium nucleatum, Actinomyces neuii and Bacteroides uniformis were notable for an increased percentage of no-identification results compared with the other anaerobes tested. VITEK^® MS identification of clinically relevant anaerobes is highly accurate and represents a dramatic improvement over other phenotypic methods in accuracy and turnaround time.     

表面增强激光解吸离子化飞行时间质谱血清蛋白指纹图谱在喉癌诊断中的应用

目的：用表面增强激光解吸离子化飞行时间质谱（SELDI-TOF—MS）分析喉癌和正常人血清蛋白指纹图谱的变化,建立能鉴别喉癌和正常人血清标志物的诊断模型。方法：收集46例喉癌患者和51例正常人的血清,用WCX2（弱阳离子交换芯片）蛋白质芯片和SELDI—TOF—MS检测蛋白质质谱的表达。用Biomarker Patterns Software分析软件进行数据处理,建立区分喉癌与正常人血清中蛋白质谱差异表达模型,并用此模型对另外12例喉癌患者及13例正常人进行盲法交叉验证。结果：在分子量2000～20000范围内,共检测到76个有差异的蛋白峰,其中27个有统计学意义（P〈0．05）,建立了由3个差异蛋白组成的喉癌诊断模型,其准确率为88．7％（86／97）,敏感性为87％（40／46）,特异性为90．2％（46／51）,双盲法验证结果其敏感性为83．3％（10／12）,特异性为84．6％（11／13）。结论：用SELDI—TOF—MS技术初步建立的区分喉癌与正常人血清蛋白差异表达模型可以区别喉癌和正常人,可能为喉癌的早期诊断提供了新的手段。     

应用蛋白质组学技术筛选胰腺癌生物标志物的研究进展

胰腺癌是一种十分凶险的恶性肿瘤.胰腺癌早期症状不明显,临床确诊的患者多已处于中晚期,大多失去手术治疗机会.蛋白质组技术的快速发展为研究胰腺癌发病机制、发现早期诊断和预后的生物标志物提供了可能.本文就蛋白质组学技术在胰腺癌细胞系、组织、血清和胰液等方面的应用作一综述.     

An extractive nanoelectrospray ionization-mass spectrometry method for Chinese herbal medicine authentication

Herein, we describe a rapid, sensitive, and nondestructive method—extractive nanoelectrospray ionization-mass spectrometry (EnESI-MS)—for traditional Chinese medicine (TCM) authentication. The mass-spectral fingerprints of volatile compounds released from various TCMs can be rapidly acquired using EnESI-MS without sample pretreatment. EnESI-MS was applied to successfully differentiate between two commonly used medicinal herbs, Schisandra chinensis and Schisandra sphenanthera, which are morphologically similar but exhibit different therapeutic effects. Specific volatile compounds of each herb in a ten-component Chinese herbal product, Jia Wei Xiao Yao San, were also identified, and the method was applied to discriminate between the commercial product and a substandard version.     

MALDI-TOF-MS分析新疆食管鳞状细胞癌的蛋白组学

目的:分析新疆食管鳞状细胞癌和食管正常上皮细胞的差异表达蛋白.方法:运用激光捕获显微切割技术(LCM)分别获取食管鳞状癌细胞和食管正常上皮细胞,应用二维凝胶电泳技术(2-DE)分离纯化细胞,Imagemaster 2D软件比较分析两者电泳图谱的差异,基质辅助激光解吸电离飞行时间质谱(MALDI-TOF-MS)鉴定分析两者表达的差异蛋白.结果:建立了食管鳞状癌细胞和食管正常上皮细胞的2-DE图谱,获得43个差异蛋白点,通过质谱鉴定出17种蛋白,其中15种蛋白如Trangelin2、HSP27、S100A11、GSTP等在食管鳞状癌细胞中表达明显增高,2种蛋白如SCCA1,在食管鳞状癌细胞中表达明显降低.结论:提示17种差异蛋白可能与食管鳞状细胞癌的发生和发展有关,为筛选食管鳞状细胞癌的特异性分子标志物奠定基础.     

皮肤细胞蛋白质组质谱分析方法的建立及肽质量指纹图谱的构建

目的建立人皮肤细胞蛋白质组学研究所需的质谱分析方法,并获得皮肤细胞蛋白质肽质量指纹图谱。方法体外培养人皮肤成纤维细胞与角质形成细胞,采用固相pH梯度双向凝胶电泳分离其总蛋白质,凝胶经染色后,在图谱上选取2个角质形成细胞蛋白点与1个成纤维细胞蛋白点,进行胶内酶切、基质辅助激光解吸电离飞行时间(MALDI-TOF)质谱分析鉴定。结果获得3个点的肽质量指纹图谱,经Mascot软件搜索人非冗余蛋白质数据库后,鉴定为细胞骨架Actingamma1、tubulinα2及热休克蛋白HSP70。结论皮肤细胞基质辅助激光解吸电离飞行时间(MALDI-TOF)质谱分析技术的建立为皮肤蛋白质组学的进一步研究提供手段。     

马兜铃酸Ⅰ-DNA加合物合成及电喷雾质谱法检测

目的建立体外合成及检测马兜铃酸Ⅰ(aristolochic acid I,AAⅠ)-DNA加合物的方法。方法分别采用酶活化法和化学活化法活化AAⅠ后与脱氧腺苷酸反应以合成AAⅠ-DNA加合物,优化各种反应条件,使用液相色谱/串联质谱(LC/MS/MS)法对合成的AAⅠ-DNA加合物进行结构鉴定。结果两种方法均可制得AAⅠ-DNA加合物,质谱负离子采集模式下测得其准分子离子峰m/z621,电喷雾串联质谱(ESI-MS/MS)谱图提供了丰富的结构信息。结论AAⅠ活化后能与腺嘌呤形成AAⅠ-DNA加合物,LC/MS/MS技术能够快速方便准确地检测AAⅠ-DNA加合物。     

蛋白质组学技术分析小鼠中脑能量代谢蛋白

目的：采用蛋白质组学技术鉴定小鼠中脑部位与能量代谢相关的蛋白,探讨这些蛋白与神经性疾病的关系。方法提取小鼠中脑蛋白质,采用双向电泳分离,切取蛋白点进行基质辅助激光解吸/电离飞行时间质谱(MALDI-TOF MS)鉴定。结果双向电泳技术结合 MALDI-TOF MS 成功鉴定出24个与能量代谢相关蛋白。结论建立了小鼠中脑部位蛋白质的鉴定方法,为探讨这类蛋白质在神经系统疾病中的作用奠定了基础。