原发性IgA肾病与非IgA肾病生物化学鉴别诊断方法探索

目的: 研究探讨原发性IgA肾病和非IgA肾病的生物化学鉴别诊断方法。方法选取我院收治确诊为原发性IgA肾病和非IgA肾病且未经治疗的患者共60例作为研究对象。空腹状态下采集4ml静脉血标本,经处理后使用基质辅助激光解吸电离飞行时间质谱技术分别对患者的血清肽质量指纹图谱进行分析。结果: 经分析,原发性IgA肾病和非IgA肾病的血清肽质量指纹图谱有9个差异多肽,其中多肽峰5338是粘蛋白4同工型的片段,多肽峰2082是α1-Ⅱ型胶原同工型的片段。结论: 质谱的应用在肾病的诊断鉴别中有重要的意义,依据血清肽指纹图谱鉴别在IgA肾病和非IgA肾病的具有可行性。     

应用SRAP标记构建山药种质资源DNA指纹图谱

利用30对多态性良好的SRAP引物对90份山药种质资源进行PCR扩增,构建扩增图谱,共扩增到722个位点,多态性位点581个,多态性比例为80.47%,每对引物组合检测多态性位点3~30个,每对引物能鉴别6~51份山药种质资源;采用DNA数据分析软件对扩增出的多态性位点进行分析,构建山药种质资源方框指纹图谱,该图谱清晰地反映出每对引物能扩增的多态位点数、鉴别资源份数及资源具体编号,资源在该引物组合下所能检测得到的多态位点数及所处的具体位置等信息;从10对SRAP引物组合中挑选出的21个多态性位点,根据谱带的有无转化成的1/0字符串编码,形成山药种质资源DNA数字指纹图谱,该图谱可鉴别区分90份山药种质资源中的82份资源。同时这些指纹图谱可为下一步的山药品种鉴定,种质资源评价、利用,分子标记辅助育种及品种权保护提供技术支撑。     

RAPD技术在昆虫学研究中的进展

综合论述了RAPD技术在昆虫分类学、物种的亲缘关系、系统发育、分子连锁图谱的构建、有害生物鉴定、害虫抗药性诊断、分子标记辅助育种和生态学这几方面研究中的应用,指出RAPD技术存在的问题,并提出一定的相关对策,阐明随着理论的发展和试验技术的进步,分子标记技术将使昆虫分子生物学研究迈上一个新台阶．     

中国农作物病虫图谱(第一集)

这本图谱是按照农作物的分类编著的,内容分为病害、虫害两部分。在虫害部分,计有稻作害虫16种、麦类害虫15种、杂粮害虫4种、薯类害虫3种、棉花和麻类害虫15种、桑树害虫4种、糖料作物和烟草害虫3种、豆类害虫3种、果树害虫17种、蔬菜害虫10种、储粮害虫9种、蝗虫12种。这些害虫,都是目前生产上的重要害虫。 每种害虫均绘制彩色图,分为各期虫态和被害物,并附有相应的简要说明,包括害虫的名称(学名、科     

PCR技术在植物病原细菌研究中的应用*

利用rep-PCR、AFLP和RAPD等多种基因组指纹分析方法,指纹图谱结合计算机辅助分析,用于研究植物病原细菌群体遗传多样性;遗传多样性图谱有助于理解病原细菌的分类、群体结构,还有利于设计特异、灵敏、快速检测策略用于植物病原检测和病害诊断。已有许多以PCR为基础的检测技术如rDNA-PCR、ITS-PCR、ARDRA等,有很多特异性引物及检测程序,已在植物病原检测和病害诊断中广泛应用。PCR技术的应用和计算机的辅助分析,为植物病原细菌群体动态和生态学知识提供了基本框架,使植物病理学进入一个新时代。     

紫外指纹图谱结合化学计量学对黄精基原植物的鉴别

运用紫外光谱技术结合化学计量学,建立快速鉴别不同基原黄精的方法。通过单因素实验确定黄精最佳提取溶剂、时间和用量,制备测试液,采用紫外光谱技术建立3种基原黄精的紫外指纹图谱,光谱数据转化后进行主成分(PCA)和系统聚类分析(HCA)。该方法重现性、精密度、稳定性较好,结果表明不同种类黄精紫外指纹图谱具有指纹特性,3种基原植物黄精紫外光谱图在210 nm、220 nm、280 nm附近差异明显;聚类分析和主成分分析三维投影图反映出不同种类黄精的化学成分积累具有差异,能较好地区分滇黄精(Polygonatumkingianum)、黄精(P.sibiricum)与多花黄精(P.cyrtonema)。紫外光谱结合化学计量学能快速鉴别不同种类黄精,可作为黄精的鉴别和质量控制新方法,为黄精临床应用、资源开发及黄精属植物分类提供辅助方法。     

茶树病虫害多媒体数据库的开发研究

本介绍了应用Ｖｉｓｕａｌ ｆｏｘｐｒｏ６．０语言、结合我我媒体技术开发茶树病虫害数据库的结果。该数据库包括：４２种茶树害虫和２１种茶树病害的鉴别、咨询知识库,主要病虫的测报、防治决策专家系统,常用农药知识库及系统维护等模块,是一种查询简便、计算的茶树病虫计算机决策系统。     

PCR技术在植物病原细菌研究中的应用

利用rep-PCR,AFLP和RAPD等多种基因组指纹分析方法,指纹图谱结合计算机辅助分析,用于研究植物病原细菌群体遗传多样性;遗传多样性图谱有助于理解病原细菌的分类,群体结构。还有利于设计特异,灵敏,快速检测策略用于植物病原检测和病害诊断。已有许多以PCR为基础的检测技术如rDNA-PCR,ITS-PCR,ARDRA等,有很多特异性引物及检测程序,已在植物病原检测和病害诊断中广泛应用,PCR技术的应用和计算机的辅助分析。为植物病原细菌群体动态和生态学知识提供了基本框架,使植物病理学进入一个新时代。     

IPM计算机决策技术简述

害虫综合管理的对象是一个复杂的生态系统。计算机已成为操纵这种复杂系统的有效决策工具。ＩＰＭ统计分析,模型生成,生态过程模拟和数据管理是计算机辅助决策的初级形式。在此基础上,ＩＰＭ决策过程的计算机化在近几年达到了很高的程度,出现了ＩＰＭ决策支持和专家系统。这标志着ＩＰＭ科学决策时代的到来。在某种意义上,计算机软硬件的技术进步改变了ＩＰＭ的过去,影响着ＩＰＭ的现在,决定着ＩＰＭ的未来。     

昆虫脑神经髓结构图谱构建方法综述

脑控制和调节所有动物的行为,昆虫也不例外,构建脑神经髓结构图谱有利于阐明其对行为调控的神经机制.目前,除一些模式昆虫的脑图谱被构建外,大多数昆虫仅针对少数易识别的神经髓(如视叶、触角叶和蕈形体等)进行了三维重建,而对脑内大部分区域还未描述,这与其结构的复杂性有关.随着共聚焦显微成像和计算机三维重建技术的发展,人们有机会...     

Screening,library-assisted identification and validated quantification of oral antidiabetics of the sulfonylurea-type in plasma by atmospheric pressure chemical ionization liquid chromatography-mass spectrometry

An atmospheric pressure chemical ionization liquid chromatographic-mass spectrometric (APCI-LC-MS) LC-MS assay is presented for fast and reliable screening and identification as well as precise and sensitive quantification of oral antidiabetics of the sulfonylurea-type (OADs) in plasma. It allowed the specific diagnosis of an overdose situation or a Munchausen syndrome caused by ingestion of OADs. After liquid-liquid extraction, the OADs glibenclamide, glibornuride, gliclazide, glimepiride, glipizide, gliquidone, glisoxepide, tolazamide and tolbutamide were separated using fast gradient elution. After screening and identification in the scan mode using our new LC-MS library, the OADs were quantified in the selected-ion mode. The quantification assay was validated according to the criteria established by the Journal of Chromatography B. All validation data were inside the required limits. The assay is part of a general LC-MS procedure for fast screening, identification and quantification of different toxicologically relevant compounds in plasma and has proven to be appropriate for OADs.     

双孢蘑菇菇脚氨基酸含量的测定及营养评价

测定了双孢蘑菇菇脚中蛋白质和氨基酸的含量,应用模糊识别法和氨基酸比值系数法,以鸡蛋蛋白为标准蛋白,以WHO/FAO的必需氨基酸参考模式为评价标准,对双孢蘑菇菇脚的蛋白质营养价值进行了全面评价,并与双孢蘑菇子实体的蛋白质进行比较.结果表明:双孢蘑菇菇脚蛋白质中总氨基酸含量为73.16％,氨基酸种类齐全,必需氨基酸含量占氨...     

Identification of gametes and treatment of linear dependencies in the gametic QTL-relationship matrix and its inverse

The estimation of gametic effects via marker-assisted BLUP requires the inverse of the conditional gametic relationship matrix G. Both gametes of each animal can either be identified (distinguished) by markers or by parental origin. By example, it was shown that the conditional gametic relationship matrix is not unique but depends on the mode of gamete identification. The sum of both gametic effects of each animal – and therefore its estimated breeding value – remains however unaffected. A previously known algorithm for setting up the inverse of G was generalized in order to eliminate the dependencies between columns and rows of G. In the presence of dependencies the rank of G also depends on the mode of gamete identification. A unique transformation of estimates of QTL genotypic effects into QTL gametic effects was proven to be impossible. The properties of both modes of gamete identification in the fields of application are discussed.     

The identification of trimethylsilylated dipeptides with chemical ionization mass spectrometry.

The chemical ionization (CI) and electron impact (EI) mass spectra were compared for over 40 trimethylsilylated (Me₃Si) dipeptides. The dipeptides chosen had all 20 common amino acids represented at amino and carboxyl positions. The CI mass spectra of Me₃Si dipeptides typically contain three ions of high abundance used for dipeptide identification: a sequence-determining ion and two molecular weight-determining ions. The intensity of the molecular weight-determining ions relative to that of the ion that characterizes the N-terminal residue (β-cleavage ion) is greater in the CI mode than in the EI mode. Because the available intensity of the β-cleavage ion is similar in both modes, use of the CI mode will extend the lower limit for Me₃Si dipeptide identification.     

Rapid protein identification using direct infusion nanoelectrospray ionization mass spectrometry

Current protein identification techniques are largely based on MALDI-TOF mass fingerprinting and LC-ESI MS/MS sequence tag analysis. Here we describe an improved method for rapid protein identification that uses direct infusion nanoelectrospray quadrupole time-of-flight (nanoESI QTOF) MS. Protein digests were analyzed without LC separation using nanoESI on a QSTAR XL MS/MS system in information dependent data acquisition mode. The protein identification conditions and parameters were extensively evaluated with in-solution and in-gel digested protein samples. Rapid identification of proteins was achieved and compared directly to the results obtained on the same samples using nanoflow HPLC-MS/MS on the QSTAR system. The increased throughput, reproducibility, the high data quality, and the ease of use make the direct infusion system an efficient and affordable technique for protein identification analysis.     

Applications and performance of a MALDI-ToF mass spectrometer with quadratic field reflectron technology

A new matrix-assisted laser desorption/ionization time of flight mass spectrometer (MALDI-ToF MS), developed specifically for the identification and characterization of proteins and peptides in proteomic investigations, is described. The mass spectrometer which can be integrated with the 2-D gel electrophoresis workflow is a bench-top instrument, enabling rapid, reliable and unattended protein identification in low-, as well as high-throughput proteomics applications. To obtain precise information on peptide sequences, the instrument utilizes a timed ion gate and a unique quadratic field reflectron (Z2 technology), allowing single-run, post-source decay (PSD) of selected peptides. In this study, the performance of the instrument in reflectron, PSD and linear mode, respectively, was investigated. The results showed that the limit of detection for a single peptide in reflectron mode was 125 amol with a signal to noise ratio exceeding 20. Average mass resolution for peptides larger than 2000 u was around 13,000 full width, half maximum (FWHM). The limit for protein identification during peptide mass fingerprinting (PMF) was 500 amol with a sequence coverage of 18%. Mass error during PMF analysis was less than 15 ppm for 17 out of 25 (68%) identified peptides. In PSD mode, a complete series of y-ions of a CAF-derivatized peptide could be obtained from 3.75 fmol of material. The average mass error of PSD-generated fragments was less than 0.14 u. Finally, in linear mode, intact proteins with molecular masses greater than 300,000 u were detected with mass errors below 0.2%.     

Intact protein profiling in breast cancer biomarker discovery: Protein identification issue and the solutions based on 3D protein separation,bottom‐up and top‐down mass spectrometry

Proteomics profiling of intact proteins based on MALDI‐TOF MS and derived platforms has been used in cancer biomarker discovery studies. This approach suffers from a number of limitations such as low resolution, low sensitivity, and that no knowledge is available on the identity of the respective proteins in the discovery mode. Nevertheless, it remains the most high‐throughput, untargeted mode of clinical proteomics studies to date. Here we compare key protein separation and MS techniques available for protein biomarker identification in this type of studies and define reasons of uncertainty in protein peak identity. As a result of critical data analysis, we consider 3D protein separation and identification workflows as optimal procedures. Subsequently, we present a new protocol based on 3D LC‐MS/MS with top‐down at high resolution that enabled the identification of HNRNP A2/B1 intact peptide as correlating with the estrogen receptor expression in breast cancer tissues. Additional development of this general concept toward next generation, top‐down based protein profiling at high resolution is discussed.     

Discovery of a potent CDK2 inhibitor with a novel binding mode, using virtual screening and initial, structure-guided lead scoping

Virtual screening against a pCDK2/cyclin A crystal structure led to the identification of a potent and novel CDK2 inhibitor, which exhibited an unusual mode of interaction with the kinase binding motif. With the aid of X-ray crystallography and modelling, a medicinal chemistry strategy was implemented to probe the interactions seen in the crystal structure and to establish SAR. A fragment-based approach was also considered but a different, more conventional, binding mode was observed. Compound selectivity against GSK-3beta was improved using a rational design strategy, with crystallographic verification of the CDK2 binding mode.     

Discovery of novel drug targets and their functions using phenotypic screening of natural products

Natural products are valuable resources that provide a variety of bioactive compounds and natural pharmacophores in modern drug discovery. Discovery of biologically active natural products and unraveling their target proteins to understand their mode of action have always been critical hurdles for their development into clinical drugs. For effective discovery and development of bioactive natural products into novel therapeutic drugs, comprehensive screening and identification of target proteins are indispensable. In this review, a systematic approach to understanding the mode of action of natural products isolated using phenotypic screening involving chemical proteomics-based target identification is introduced. This review highlights three natural products recently discovered via phenotypic screening, namely glucopiericidin A, ecumicin, and terpestacin, as representative case studies to revisit the pivotal role of natural products as powerful tools in discovering the novel functions and druggability of targets in biological systems and pathological diseases of interest.     

Clean absorption mode NMR data acquisition based on time-proportional phase incrementation

Clean absorption mode NMR data acquisition is presented based on mirrored time domain sampling and widely used time-proportional phase incrementation (TPPI) for quadrature detection. The resulting NMR spectra are devoid of dispersive frequency domain peak components. Those peak components exacerbate peak identification and shift peak maxima, and thus impede automated spectral analysis. The new approach is also of unique value for obtaining clean absorption mode reduced-dimensionality projection NMR spectra, which can rapidly provide high-dimensional spectral information for high-throughput NMR structure determination.