基质辅助激光解吸电离飞行时间质谱在临床微生物检测和鉴定中的应用

现今临床主要通过观察细菌菌落形态、革兰染色、显微镜检查,以及各种生化试验等方法对致病菌进行检测和鉴定。这些方法主要依赖致病菌的生长代谢,其周期较长,并且带有一定的主观性［1］,不能满足临床上对致病菌进行快速诊断的需要。基质辅助激光解吸电离飞行时间质谱（ matrix assisted laser desorption／ionization time-of-fight mass spectrometry , MALDI-TOF MS）的诞生和发展奠定了用蛋白质指纹图谱鉴定微生物的基础。通过检测未知微生物的蛋白质指纹图谱并与质谱图数据库中特征性谱图进行比对,从而对待测微生物进行快速鉴定。该技术具有速度快,灵敏度高,操作简单,信息直观,成本低廉等特点,在对病原微生物进行快速鉴定方面具有良好的应用前景。     

人体体液多肽组质谱分析方法优化

人体体液中多肽组成分近年来获得越来越多的关注。不同体液作为不同器官、细胞在生理或病理状态下的分泌产物,对其成分特定改变的监测具有无创性、早期、敏感特异地预测人体健康状态、疾病变化、治疗疗效、药物毒性等体内变化方面的潜力。而体液成分多而复杂,体液系统易受干扰,富集、提取分离出相对分子质量整体较低的多肽组成分并进行特定多肽成分的准确计量非常重要而具有挑战性。目前对人体体液多肽组成分的研究多采用基质辅助激光解吸电离飞行时间质谱法。对此方法的实验偏差进行分析、提出改进方法,可以提高人体体液多肽组成分分析的准确性。应用基质辅助激光解吸电离飞行时间质谱法对人体体液多肽组成分进行质谱分析是人体健康状况临床检查的新思路,其中特定多肽组成分有潜力成为监测人体相关部位健康状况的生物标志物。     

复发性卵巢癌血清差异表达蛋白分析

目的探讨血清差异表达蛋白对提高复发性卵巢癌的诊断意义。方法采用弱阳离子（WCX）磁珠纯化试剂盒和基质辅助激光解吸电离飞行时间质谱（MALDI-TOF-MS）技术,对21例复发性卵巢癌和18例完全临床缓解期卵巢癌患者（对照组）的血清标本进行检测,筛选出复发性卵巢癌患者与对照组血清中的差异表达质谱峰,并建立诊断模型。结果在Mr1000～12000区段,发现复发性卵巢癌与对照组间差异表达蛋白峰10个（P〈0.05）。其中Mr1944、1980、2080、2661、2993、4450、4659、5359的蛋白峰显著上调,Mr1897、7868则显著下调。结论 MALDI-TOF-MS结合磁珠技术能直接检测出复发性卵巢癌患者血清差异表达蛋白,对提高复发性卵巢癌诊断的敏感性和特异性具有一定的临床意义。     

3种MALDI⁃TOF MS微生物鉴定系统的比较研究

目的 比较基质辅助激光解吸电离飞行时间质谱(MALDI-TOF MS)的3个微生物鉴定系统[法国生物梅里埃公司的VITEK MS(包括IVD和RUO)、德国布鲁克公司的Biotyper和国内融智生物科技公司的QuanID]对各种致病微生物的鉴定效果.方法 采用直涂法对33个属75个种共121株常见致病微生物菌株进行鉴定...     

基于基质辅助激光解吸电离飞行时间质谱技术建立结直肠癌诊断模型及初步验证

目的 基于基质辅助激光解吸电离飞行时间质谱(MALDI-TOF MS)技术建立结直肠癌(CRC)诊断模型,寻找CRC潜在的血清学标志物。方法 收集自2018年12月至2020年12月于联勤保障部队960医院就诊的114例CRC初诊患者(CRC组)和进行体检的60例健康体检者(健康组)的血清标本,按照3∶1的比例随机分为训练组131例(CRC患者87例,健康者44例)与验证组43例(CRC患者27例,健康者16例),分别用于模型的建立和初步验证。应用弱阳离子交换磁珠(MB-WCX)进行血清中低丰度蛋白提取纯化,经MALDI-TOF MS筛选CRC组和健康组中差异蛋白峰;基于3种算法(遗传算法、监督神经网络算法和快速分类算法)建立诊断模型,选取差异最显著的两个蛋白峰做聚类分析,将验证组数据带入诊断模型验证其敏感性、特异性及诊断效率。结果 CRC组与健康组蛋白指纹图谱存在明显差异,共筛选出9个有统计学意义的差异蛋白峰(曲线下面积>0.70),在CRC组表达上调7个,下调2个;其中,m/z 4645.32和m/z 5906.48差异最显著(P<0.01),曲线下面积分别为0.91、...     

生物质谱技术在蛋白质结构鉴定中的应用进展

本文综述了生物质谱技术在蛋白质结构鉴定中的应用新进展,讨论了生物质谱在蛋白质初步鉴定、蛋白质翻译后修饰的鉴别、蛋白质-蛋白质间相互作用等研究方面的应用趋势,以及生物质谱仪的一些最新发展,指出了生物质谱技术现存的主要问题,探讨了可能的解决方案。     

生物组织的基质辅助激光解吸电离质谱成像新进展

基质辅助激光解吸电离质谱成像技术分析组织切片已成为临床质谱学的一个新领域。该技术通过研究生物组织产生的“二维离子密度图像”，可以快速评估完整组织中蛋白质、药物及其代谢产物的空间分布。利用质谱成像技术研究阿尔茨海默病、神经胶质瘤、肺癌和前列腺癌等组织取得一定进展，本文对质谱成像原理、方法学及相关应用进行了综述。     

脑损伤后大鼠海马差异蛋白质组学分析

目的 研究脑损伤后大鼠海马组织蛋白质组差异表达变化情况.方法 采用侧方液压冲击装置,建立大鼠中度脑损伤模型,分别取外伤组(3只)与假手术组(3只)大鼠海马组织总蛋白,通过差异荧光双向凝胶电泳(DIGE)分离蛋白,获得蛋白质分离图谱,经胶内酶切、抽提酶解肽段、MALDI-TOF/TOF质谱分析研究差异的蛋白质点,鉴定出变化的蛋白质.结果 经De-Cyder 5.0及BVA图像分析软件比较,发现17个蛋白点表达水平具有显著差异变化.鉴定出的蛋白质考染点含有14个蛋白质,2个为同一种蛋白,实际差异蛋白数为13个.依其功能属于细胞骨架蛋白、介导能量代谢的酶类、参与核酸合成及氧化应激反应的蛋白质、神经突触功能蛋白、细胞内信号传递蛋白及未知蛋白. 结论脑损伤后大鼠海马组织蛋白质表达谱存在差异,并初步鉴定出脑损伤后差异表达蛋白,为深入研究脑损伤的病理机制奠定基础.     

应用基质辅助激光解吸电离飞行时间质谱研究细菌性血流感染的血清多肽指纹图谱

目的 应用基质辅助激光解吸电离飞行时间质谱系统(MALDI-TOF MS)分析金黄色葡萄球菌、大肠埃希菌引起的血流感染血清多肽指纹图谱,寻找差异多肽峰并建立相应的诊断模型.方法 建立ICR小鼠金黄色葡萄球菌、大肠埃希菌血流感染模型,收集血清标本,经弱阳离子交换磁珠纯化,MALDI-TOF MS检测及BioExplorer生物软件分析研究金葡菌感染组与正常对照组、大肠埃希菌感染组与正常对照组间血清多肽指纹图谱.结果 比较金葡菌感染组与正常对照组发现,表达上调的多肽有6个,表达下调的多肽有7个,表达呈先上调后下调的多肽有8个.比较大肠埃希感染组与正常对照组发现,表达下调的多肽有5个,表达呈先下调后上调的多肽有4个,表达呈先上调后下调的多肽有8个.结论 利用MALDI-TOF MS技术和BioExplorer软件研究大肠埃希菌和金黄色葡萄球菌血流感染的血清多肽,可以发现感染组与正常对照组间的差异多肽并有效地建立这两种细菌感染的诊断模型,对于细菌性血流感染的诊断具有一定的价值.     

乳腺癌患者血清蛋白质组的特征研究

目的比较乳腺癌患者、乳腺良性病患者及健康女性血清蛋白质组的差异,以期发现可用于乳腺癌诊断的生物学指标。方法采用表面增强激光解吸离子化飞行时间质谱(SELDI-TOF-MS)蛋白芯片技术,检测46例乳腺癌患者、40例乳腺良性病患者及40例健康女性血清,筛选出有分类意义的差异蛋白并建立分类树模型。再从同期住院或健康体检人群中随机抽取乳腺癌患者、乳腺良性病患者及健康女性各10例组成测试组,对诊断分类树模型进行独立双盲验证。结果比较三组血清,共发现22种差异蛋白质(P<0.05),由其中质荷比(M/Z)为3162、3960、4213、4526、5908、5386、11383、11735、13892、6007的10种蛋白建立的诊断分类树模型,对乳腺癌、乳腺良性病、健康女性的分类准确率为98.4%(124/126),灵敏度及特异度分别为100.0%(46/46)和97.5%(78/80),经独立双盲验证该模型诊断乳腺癌的准确率、灵敏度及特异度分别为83.3%(25/30)、80.0%(8/10)、85.0%(17/20)。结论利用SELDI-TOF-MS技术建立的乳腺癌诊断分类树模型具有较高的敏感度和特异度,可用于乳腺癌...     

Negative spot sign in primary intracerebral hemorrhage: potential impact in reducing imaging

Intracerebral hemorrhage (ICH) is one of the most devastating and costly diagnoses in the USA. ICH is a common diagnosis, accounting for 10–15 % of all strokes and affecting 20 out of 100,000 people. The CT angiography (CTA) spot sign, or contrast extravasation into the hematoma, is a reliable predictor of hematoma expansion, clinical deterioration, and increased mortality. Multiple studies have demonstrated a high negative predictive value (NPV) for ICH expansion in patients without spot sign. Our aim is to determine the absolute NPV of the spot sign and clinical characteristics of patients who had ICH expansion despite the absence of a spot sign. This information may be helpful in the development of a cost effective imaging protocol of patients with ICH. During a 3-year period, 204 patients with a CTA with primary intracerebral hemorrhage were evaluated for subsequent hematoma expansion during their hospitalization. Patients with intraventricular hemorrhage were excluded. Clinical characteristics and antithrombotic treatment on admission were noted. The number of follow-up NCCT was recorded. Of the resulting 123 patients, 108 had a negative spot sign and 7 of those patients subsequently had significant hematoma expansion, 6 of which were on antithrombotic therapy. The NPV of the CTA spot sign was calculated at 0.93. In patients without antithrombotic therapy, the NPV was 0.98. In summary, the negative predictive value of the CTA spot sign for expansion of ICH, in the absence of antithrombotic therapy and intraventricular hemorrhage (IVH) on admission, is very high. These results have the potential to redirect follow-up imaging protocols and reduce cost.     

噬菌体治疗细菌性疾病的研究进展

噬菌体自发现之初就被人们应用于治疗各种细菌感染.近年来由于各种耐药菌株的出现,新抗生素的研制困难重重,研究噬菌体用于治疗细菌性疾病又重新受到重视.本文综述了近年来噬菌体治疗方面的研究进展.     

Image-guided brachytherapy for cervical cancer: Analysis of D2 cc hot spot in three-dimensional and anatomic factors affecting D2 cc hot spot in organs at risk

PurposeTo analyze the D_{2 cc} hot spot in three-dimensional CT and anatomic factors affecting the D_{2 cc} hot spot in organs at risk (OARs).Methods and MaterialsThirty-one patients underwent pelvic CT scan after insertion of the applicator. High-dose-rate treatment planning was performed with standard loading patterns. The D_{2 cc} structures in OARs were generated in three dimensional if the total equivalent dose in 2 Gy exceeded our defined dose limits (hot spot). The location of D_{2 cc} hot spot was defined as the center of the largest D_{2 cc} fragment. The relationship between the hot spot and the applicator position was reported in Digital Imaging and Communication in Medicine coordinates.ResultsThe location of sigmoid, small bowel, and bladder D_{2 cc} hot spots was around the endocervix: The mean location of sigmoid hot spot for lateral view was 1.6 cm posteriorly and 2.3 cm superiorly (Y, 1.6 and Z, 2.3), small bowel was 1.6 cm anteriorly and 2.7 cm superiorly (Y, −1.6 and Z, 2.7). The mean location of bladder hot spot was 1.6 cm anteriorly and 1.6 cm superiorly (Y, −1.6 and Z, 1.6). These hot spots were near the plane of Point A (X, 2.0 or −2.0; Y, 0; and Z, 2.0). The mean location of rectal hot spot was 1.6 cm posteriorly and 1.9 cm inferiorly (Y, 1.6 and Z, −1.9). D_{2 cc} hot spot was affected by uterine wall thickness, uterine tandem position, fibroids, bladder fullness, bowel gas, and vaginal packing.ConclusionsBecause of the location of the D_{2 cc} hot spots, larger tumors present a challenge for adequate tumor coverage with a conventional brachytherapy applicator without an interstitial implant. Additionally, anatomic factors were identified which affect the D_{2 cc} hot spot in OARs.     

Clearing a blind spot in knee arthroscopy: popliteal bursa

Each arthroscopic portal to the knee has a blind area that cannot be inspected directly. In particular, visualization of the posterior compartment is difficult to access. Although arthroscopic procedures for the posterior compartment of the knee joint have been developed through posteromedial, posterolateral and posterior trans-septal portal, the popliteal bursa remains as an area that is difficult to access and manipulate. We report a surgical procedure that can examine one of the blind spots in knee arthroscopy, popliteal bursa.     

2型糖尿病颈动脉粥样硬化斑块的初步研究

目的探讨2型糖尿病患者颈动脉粥样硬化斑块的不稳定性及发生机制。方法收集33例符合下列条件的2型糖尿病死亡患者:既往有明确的脑梗死或短暂性脑缺血发作,有相应的病史、体征以及影象学证据。同时选取年龄、性别、血压、血脂等相匹配的18例无糖尿病的死亡病例作为对照。将51例死者的双侧颈内动脉完整剥离后连续取材,常规固定、脱水、石蜡包埋、切片、HE染色,从每例中挑选一块组织行免疫组化CD3、CD68、SMA、MMP-2和MMP-9染色,光镜观察HE及免疫组化染色切片,并采用图像分析仪测定颈动脉粥样硬化斑块的纤维帽厚度以及SMA、MMP-2和MMP-9的阳性面积百分比。结果在已经发生过缺血性脑卒中的2型糖尿病病例中,颈内动脉粥样硬化斑块中不稳定斑块的比例显著高于对照组。2型糖尿病组的不稳定斑块中,CD68、CD3、MMP-2及MMP-9的表达要明显强于稳定斑块,而SMA的表达正好相反。结论 2型糖尿病颈动脉粥样硬化斑块中不稳定斑块增多,这与巨噬细胞和T细胞的浸润以及MMP分泌增多有关。     

The paper spot test: a rapid method for quantitating stannous concentrations in radiopharmaceutical kits

We have developed a simplified, semiquantitative test for the determination of stannous tin in pyrophosphate and other tin-containing radiopharmaceuticals, excluding those stabilized with ascorbic acid and MAA preparations. The test involves the formation and disappearance of a positive red color complex in the presence of Sn(II) and in acidified porphyrin solution. With this technique, the time of spot disappearance is directly proportional to the Sn(II) concentration spotted. The procedure is easy to use, requiring only a high-intensity light source (30-watt light bulb) and a timing device. The test is accurate, reproducible, and sensitive to Sn(II) levels as low as 40 micrograms/ml. Because the procedure is rapid (requiring less than 5 min), it can easily be incorporated into the routine radiopharmaceutical quality-control program of any nuclear medicine facility.     

个体化药物：转化研究的新契机

医疗模式转换和改革的重点已由传统的疾病治疗为主逐步向健康为主转移,建立以预防医学、预测医学为主的干预医学和个性化处方用药的人类生命新健康保健思路。本文从药物治疗的影响因素、个体化药物、药物基因组学等方面进行论述,以肿瘤的靶向药物为例提出发展基于基因导向的个性化药物的必要性。     

TACE治疗原发性肝癌伴门静脉癌栓研究进展

目前以TACE为基础的联合介入治疗方法,均可在不同程度控制原发性肝细胞癌(PHC)进展的同时达到缓解门静脉高压、解除门静脉阻塞、控制顽固性腹水、降低上消化道出血概率的目的,从而提高患者生活质量,延长生存期.该文就近年国内外TACE联合其它介入方法治疗PHC伴门静脉癌栓研究进展作一综述,以期为临床诊疗提供帮助.