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1.
    
Purpose : We aimed to identify novel chemotherapy responsiveness biomarkers for osteosarcoma (OS) by investigating the global protein expression profile of 12 biopsy samples from OS patients. Experimental design : Six patients were classified as good responders and six as poor responders, according to the Huvos grading system. The protein expression profiles obtained by 2‐D DIGE consisted of 2250 protein spots. Results : Among them, we identified 55 protein spots whose intensity was significantly different (Bonferroni adjusted p‐value<0.01) between the two patient groups. Mass spectrometric protein identification demonstrated that the 55 spots corresponded to 38 distinct gene products including peroxiredoxin 2 (PRDX 2). Use of a specific antibody against PRDX 2 confirmed the differential expression of PRDX 2 between good and poor responders, while PRDX 2 levels as measured by Western blotting correlated highly with their corresponding 2‐D DIGE values. The predictive value of PRDX 2 expression was further confirmed by examining an additional four OS cases using Western blotting. Conclusions and clinical relevance : These results establish PRDX 2 as a candidate for chemotherapy responsiveness marker in OS. Measuring PRDX 2 in biopsy samples before treatment may contribute to more effective management of OS.  相似文献   

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Human myometrium undergoes a major phenotypic change at labour likely involving modifications to key regulatory proteins. In some cases, the myometrium fails to activate normally and medical intervention is required to induce labour. In this study, 2‐D DIGE was used to examine changes in the myometrial proteome at the time of spontaneous (SL) and induced labour (IL). Proteomic profiles of nonlabouring term myometria (NL, n = 6) were quantitatively compared to SL (n = 6) and prostaglandin/oxytocin‐IL term myometria (n = 6). In SL samples, 23 differentially expressed protein spots were detected (9 increased/14 decreased compared to NL, p<0.05). In IL samples, 59 differentially expressed spots were observed (13 increased/46 decreased compared to NL). Comparison of SL and IL proteomes revealed 69 differentially expressed proteins (7 increased/62 decreased). Two proteins consistently decreased in SL and IL samples were identified as transgelin (1.98‐ and 1.97‐fold decrease in SL and IL, respectively) and αB‐crystallin (3.27‐ and 2.49‐fold decrease). Levels of desmin and cytosolic phospholipase A2 β were decreased 2.9‐ and 2.65‐fold, respectively only in IL samples. Our results show human labour is accompanied by general downregulation of specific myometrial proteins. Differences exist between SL and IL myometrial proteomes indicating divergence of underlying processes and highlighting the importance of distinguishing these groups in future studies of parturition. Our findings underscore the utility of discovery approaches in investigations of organ‐wide protein changes that underlie discrete physiological events including human labour.  相似文献   

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Difference gel electrophoresis enables the accurate quantification of changes in the proteome including combinations of PTMs and protein isoform expression. Here, we review recent advances in study design, image acquisition, and statistical analysis. We also compare DIGE to established and emerging mass spectrometric analysis technologies. Despite these recent advances in MS and the still unsolved limitations of 2DE to map hydrophobic, high molecular weight proteins with extreme pIs, DIGE remains the most comprehensive top-down method to study changes in abundance of intact proteins.  相似文献   

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Dendritic cells (DCs) are unique antigen presenting cells, which upon maturation change from a specialized antigen‐capturing cell towards a professional antigen presenting cells. In this study, a 2‐D DIGE analysis of immature and mature DCs was performed, to identify proteins changing in expression upon maturation. The protein expression profile of immature and mature DCs, derived from CD14+ peripheral blood monocytes was investigated using two pH ranges (pH 4–7 and 6–9) (n = 4). Ninety one differentially expressed spots (p<0.01) were detected, from which we identified 74 spots (81.32%) corresponding to 41 different proteins. The proteins identified play a role in diverse processes, such as antigen processing/presentation, vesicle transport and cytoskeleton remodeling. In addition, a protein interaction network contained 29 (out of 41) proteins, suggesting that, although they functionally originate from distinct classes, these proteins are acting as a protein‐interactome. In conclusion, the proteins shown here to be altered in expression upon maturation are in line with the morphological and functional changes observed during the maturation process, providing a better understanding of the processes involved. This will open new avenues for investigating treatment regimens for immune‐associated disorders.  相似文献   

6.
利用Windows操作系统平台正的DirectX多媒体接口技术,本文提出了利用平面图像实现三维仿真场景的相关实用技术方法。  相似文献   

7.
    
The gastrointestinal stromal tumor (GIST) is the most common mesenchymal malignancy of the gastrointestinal tract. Its clinical course ranges widely from a curable disorder to a highly malignant disease. Although its clinical and molecular characteristics depend on the anatomic site of origin, the molecular background of GIST arising in different anatomical site has not been studied yet. To investigate the proteomic background of GIST, we examined the proteomic features corresponding to the anatomic site of tumor origin. Comparison of the proteomic profile of gastric (23 cases) and small intestinal (9 cases) GIST by 2‐DE revealed 105 protein spots with significantly different intensity (p <0.01) between the two groups. Mass spectrometric study identified 68 distinct proteins for these 105 protein spots, including cancer‐associated ones such as prohibitin, pigment epithelium‐derived factor, and alpha‐actinin 4. The intensity of 37/105 (35.2%) protein spots was significantly concordant with the corresponding mRNA levels (p <0.01). Although both 2‐D DIGE and microarray experiments showed significant up‐regulation of vimentin expression in small intestinal GIST, Western blotting did not show a significant difference between the two groups. In conclusion, our study demonstrates the proteins specially expressed in GIST depending on their site of origin, as well as the unique advantage offered by use of proteomics to acquire such data. The identified proteins may provide clues to understanding the different characteristics of GIST depending on their site of origin.  相似文献   

8.
    
Now that the genomics revolution is tailing off proteomics promises an even more radical transformation of biological and medical research. Ultimately, the clues to the mysteries of biological processes will lye within the proteins present at a given time. Proteomics, the characterization of complex protein mixtures, builds on a wide range of expertise from protein chemistry to mass spectrometry and bioinformatics. Each step from sample preparation, high resolution protein separation to protein identification is underpinned by the latest technological developments in protein separation and mass spectrometry and supported by powerful computational image and data analysis algorithms which requires large scale data management and storage facilities. The success of proteomics depends on further developments in technology which need a wide range of scientific expertise. This meeting, the first BSPR London Regional Meeting, brought together scientists from a broad background who share a common interest in novel solutions for the characterization of complex protein mixtures.  相似文献   

9.
    
The receptor tyrosine kinase ErbB2 (HER2/neu) is overexpressed in ?30% of breast cancers and is associated with poor prognosis and an increased likelihood of metastasis. Clinical treatments such as trastuzumab are effective in less than 35% of women diagnosed as ErbB2‐positive, highlighting the necessity of searching for novel targets and alternative therapies. Herein, a proteomic screening strategy combining quantitative‐based gel electrophoresis and MS was used to compare the protein expression of 48 normal human breast and tumour tissues differing in ErbB2 expression and lymph node status. The aim was to identify proteins associated with the aggressive phenotype of ErbB2‐positive breast cancer which could be potential biomarkers of the disease as well as therapy targets. In total, 177 protein isoforms (107 gene products) differentially expressed between tissue groups were identified. Immunohistochemical staining of a tissue‐microarray was used for validation of selected protein candidates. We found that expression of HSP90α, laminin and GSTP1 significantly correlated with ErbB2 expression, while others such as AGR2, NM23H1 and Annexin 2 were overexpressed in greater than 40% of tumours. Finally, knocking‐down the expression by RNA interference of three candidates, AGR2, Transgelin2 and NM23H1 resulted in an enhanced invasive capacity of MDA‐MB435 cells. These data support the involvement of these targets in tumour progression and identify them as novel biomarkers of the disease.  相似文献   

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针对任意构型双基SAR基于传统Taylor级数展开斜距方法的边缘点散焦问题,提出了一种基于Legendre正交多项式逼近的双基SAR二维频域成像算法。该算法基于对斜距函数的Legendre多项式展开推导了点目标二维频谱,解除了回波信号距离—方位的耦合,使成像处理更高效。在二维频域对场景区域的点目标采用二维频域成像算法进行成像。该算法改善了场景边缘点的聚焦效果,增加了场景边缘点的聚焦深度。理论推导和仿真结果验证了该算法的有效性和可行性。  相似文献   

12.
    
Cervical cancer screening is ideally suited for the development of biomarkers due to the ease of tissue acquisition and the well-established histological transitions. Furthermore, cell and biologic fluid obtained from cervix samples undergo specific molecular changes that can be profiled. However, the ideal manner and techniques for preparing cervical samples remains to be determined. To address this critical issue a patient screening protein and nucleic acid collection protocol was established. RNAlater was used to collect the samples followed by proteomic methods to identify proteins that were differentially expressed in normal cervical epithelial versus cervical cancer cells. Three hundred ninety spots were identified via 2-D DIGE that were expressed at either higher or lower levels (>three-fold) in cervical cancer samples. These proteomic results were compared to genes in a cDNA microarray analysis of microdissected neoplastic cervical specimens to identify overlapping patterns of expression. The most frequent pathways represented by the combined dataset were: cell cycle: G2/M DNA damage checkpoint regulation; aryl hydrocarbon receptor signaling; p53 signaling; cell cycle: G1/S checkpoint regulation; and the ER stress pathway. HNRPA2B1 was identified as a biomarker candidate with increased expression in cancer compared to normal cervix and validated by Western blot.  相似文献   

13.
    
Proteomics is increasingly being applied to the human plasma proteome to identify biomarkers of disease for use in non‐invasive assays. 2‐D DIGE, simultaneously analysing thousands of protein spots quantitatively and maintaining protein isoform information, is one technique adopted. Sufficient numbers of samples must be analysed to achieve statistical power; however, few reported studies have analysed inherent variability in the plasma proteome by 2‐D DIGE to allow power calculations. This study analysed plasma from 60 healthy volunteers by 2‐D DIGE. Two samples were taken, 7 days apart, allowing estimation of sensitivity of detection of differences in spot intensity between two groups using either a longitudinal (paired) or non‐paired design. Parameters for differences were: two‐fold normalised volume change, α of 0.05 and power of 0.8. Using groups of 20 samples, alterations in 1742 spots could be detected with longitudinal sampling, and in 1206 between non‐paired groups. Interbatch gel variability was small relative to the detection parameters, indicating robustness and reproducibility of 2‐D DIGE for analysing large sample sets. In summary, 20 samples can allow detection of a large number of proteomic alterations by 2‐D DIGE in human plasma, the sensitivity of detecting differences was greatly improved by longitudinal sampling and the technology was robust across batches.  相似文献   

14.
The aim of our study was to analyze the proteomic pattern of human macrophages obtained over a 4 year period from blood donors. The purpose was to simulate a long-term clinical study to assess the application of 2-D DIGE technique for differential proteomic analysis of these scarce samples. Bioinformatic analysis of 2-D DIGE gels of 19 different cultures of macrophages assessed whether they did or did not contain at least specific five spots identified by MS as being or containing bovine deoxyribonuclease I (DNase I). Bovine DNase I was used during sample treatment to remove nucleic acids from protein extracts. Macrophages were classified in two groups, which appeared to be differentiated by the completeness of DNase I treatment. Further detailed analysis revealed a different proteomic pattern of macrophage protein samples according to the completeness of this treatment. The major group of proteins affected, accounting for one third of the differentially expressed proteins, included proteins involved in cell motion and actin cytoskeleton reorganization. The use of DNase I for the removal of nucleic acids from protein samples must be avoided in proteomic studies since it can generate bias in the analysis of protein expression patterns.  相似文献   

15.
根据一维递归Gabor滤波算法设计了二维RGF(Recursive Gabor Filtering)算法,通过实验论证了RGF不仅与Gabor 滤波等价,而且速度更快.在此基础上提出了RGF方法代替传统的Gabor滤波器方法应用到指纹特征提取,并用实验论证了参数的选择.实验结果显示该方法的有效性,具有很高的实用价值.  相似文献   

16.
设计了一种在水平坐标面内测量的高精度二维智能测头;论述了采用硬件和软件结合方法设计智能测头的总体方案。测头采用两组平行片簧组合作为微位移机构,精密差动传感器作为检测器件,根据测头的动态数学模型对系统状态估值和实际测值比较判断测头与工件接触状态,实现了测头工作的自适应控制,保证了精度与快速性要求。静态和动态试验结果证明:该测头技术指标达到了设计要求。  相似文献   

17.
基于多重压缩与加密的信息隐藏方法   总被引:2,自引:0,他引:2  
混沌系统具有对初始值的极端敏感性,具有白噪声的统计特性以及伪随机性且易生成的特点。二维条码容量大,成本低,纠错能力强并且能够自动识读,论文将二者结合起来,进行多重压缩与加密处理,即首先对信息进行压缩及混沌加密处理,然后利用二维条码来实现信息的隐藏、存储、传输和自动识读。实验表明,该方法不仅能够实现信息的保密性与安全存储,同时还能够实现信息的自动识读。  相似文献   

18.
文章提出了一种新型二维边沿检测滤波器,利用二维滤波器模板与任意方向边沿的互相关最大值检测边沿,具有良好的噪声特性及较小的系统误差。  相似文献   

19.
    
Purpose : Exercise‐induced proteinuria is a well‐known phenomenon and the influence of parameters such as intensity and duration was studied extensively. Usually, total protein or albumin was measured for diagnosis of a proteinuria, and the present study was performed to search for qualitative differences in the urinary proteome before and after endurance exercise. Experimental design : Urine samples were concentrated and proteins separated by means of 2‐D PAGE. Proteins differing in the investigated groups were identified by nano‐UPLC‐Orbitrap MS after trypsin digestion. Results : The study yielded several proteins such as hemopexin, albumin, orosomucoid 1, transferrin or carbonic anhydrase 1 that were elevated after a marathon run in comparison to a control group. These are linked to physiological changes resulting from endurance exercise such as destruction of erythrocytes or increased fat metabolism. On the contrary, 2‐D PAGE profiles of athletes at rest did not differ from those of control samples. Conclusions and clinical relevance: The study is a starting point to build up individual 2‐D PAGE protein maps of athletes. Further studies will investigate intra‐individual differences and further exercise parameters, which potentially lead to a physiological monitoring system for athletes in training and competition and may also complement the blood passport in doping control.  相似文献   

20.
本文指出并纠正了文[1~3]关于2-D系统模能控性和模能观性判据的错误。  相似文献   

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