肝癌微环境中影响转移相关通路的基因富集分析

目的 探讨肝癌微环境对肝癌发生门静脉转移起重要作用的基因簇或通路,为肝癌的治疗和研究提供理论依据.方法 利用基因组富集（GSEA）的方法,对美国国家生物技术信息中心（NCBI）的综合性的基因表达与杂交排序数据库（GEO数据库）中的11例肝癌无门静脉癌栓（PVTT）和9例肝癌合并PVTT的癌旁相对正常组织基因表达谱芯片进行分析,分析其在肿瘤相关通路中的富集特征与核心富集基因.结果 找到15条相关的信号通路,这些通路与癌旁微环境中的免疫功能状态有关,对于肝癌发生PVTT转移可能起重要作用.结论 肝癌发生门静脉转移除了与肿瘤细胞本身的恶性增殖和侵袭有关以外,还与周围微环境中的免疫状态和炎症反应有重要联系.     

基于DCMTK实现DICOM医学影像文件与常见格式的转换

目的 使用简单快捷的方法实现DICOM图像格式向常用图像格式转换.方法 采用面向对象的思想解析DICOM文件,参考和使用DCMTK工具包对DICOM图像进行转换.结果 建立VC++项目,基于DCMTK工具包,实现DICOM医学影像向几种常见格式的转换.结论 这种方法简单快捷地实现了几种格式转换,转换后的图像完全达到了使用标准,并极大地方便后续处理和操作.     

Serum markers detect the presence of liver fibrosis: a cohort study

BACKGROUND & AIMS: Histologic examination of a liver biopsy specimen is regarded as the reference standard for detecting liver fibrosis. Biopsy can be painful and hazardous, and assessment is subjective and prone to sampling error. We developed a panel of sensitive automated immunoassays to detect matrix constituents and mediators of matrix remodeling in serum to evaluate their performance in the detection of liver fibrosis. METHODS: In an international multicenter cohort study, serum levels of 9 surrogate markers of liver fibrosis were compared with fibrosis stage in liver biopsy specimens obtained from 1021 subjects with chronic liver disease. Discriminant analysis of a test set of samples was used to identify an algorithm combining age, hyaluronic acid, amino-terminal propeptide of type III collagen, and tissue inhibitor of matrix metalloproteinase 1 that was subsequently evaluated using a validation set of biopsy specimens and serum samples. RESULTS: The algorithm detected fibrosis (sensitivity, 90%) and accurately detected the absence of fibrosis (negative predictive value for significant fibrosis, 92%; area under the curve of a receiver operating characteristic plot, .804; standard error, .02; P < .0001; 95% confidence interval, .758-.851). Performance was excellent for alcoholic liver disease and nonalcoholic fatty liver disease. The algorithm performed equally well in comparison with each of the pathologists. In contrast, pathologists' agreement over histologic scores ranged from very good to moderate (kappa = .97-.46). CONCLUSIONS: Assessment of liver fibrosis with multiple serum markers used in combination is sensitive, specific, and reproducible, suggesting they may be used in conjunction with liver biopsy to assess a range of chronic liver diseases.     

Coherent Point Drift Registration Combined with Image Feature and its Application

A key step of constructing active appearance model is requiring a set of appropriate training shapes with well-defined correspondences. In this paper, we introduce a novel point correspondence method （FB-CPD）, which can improve the accuracy of coherent point drift （CPD） by using the information of image feature. The objective function of the proposed method is defined by both of geometric spatial information and image feature information, and the origin Gaussian mixture model in CPD is modified according to the image feature of points. FB-CPD is tested on the 3D prostate and liver point sets through the simulation experiments. The registration error can be reduced efficiently by FB-CPD. Moreover, the active appearance model constructed by FB-CPD can obtain fine segmentation in 3D CT prostate image. Compared with the original CPD, the overlap ratio of voxels was improved from 88.7% to 90.2% by FB-CPD.     

CDCA8对肝细胞癌患者预后的影响

目的：肝细胞癌预后相关的分子标志物对提高患者生存质量和改善疗效至关重要,本研究旨在探究细胞分裂周期相关基因8(cell division cycle associated 8,CDCA8)对肝细胞癌预后的影响及潜在分子机制。方法：432例肝细胞癌样本的转录组数据及对应患者的临床信息下载自肿瘤基因表达图谱（The Cancer Genome Atlas,TCGA）数据库。分析肿瘤组织和正常组织中CDCA8 mRNA差异;根据CDCA8 mRNA中位数将肝细胞癌患者分为高表达组和低表达组,绘制生存曲线。采用Kruskal检验分析CDCA8与肿瘤分期、分级和T分期的相关性。采用单因素和多因素Cox回归分析探究CDCA8能否作为肝细胞癌患者的独立预后因子。采用基因集富集分析（gene set enrichment analysis,GSEA）探究CDCA8在肝细胞癌中的潜在作用机制。结果：CDCA8在肿瘤组织中的mRNA水平明显高于正常对照组织（P<0.001）,CDCA8高表达患者的生存率明显低于低表达组（P<0.001）。随着肿瘤分期（P<0.001）、分级（P<0...     

Statistical Region-Based Segmentation of Ultrasound Images

Segmentation of ultrasound images is a challenging problem due to speckle, which corrupts the image and can result in weak or missing image boundaries, poor signal to noise ratio and diminished contrast resolution. Speckle is a random interference pattern that is characterized by an asymmetric distribution as well as significant spatial correlation. These attributes of speckle are challenging to model in a segmentation approach, so many previous ultrasound segmentation methods simplify the problem by assuming that the speckle is white and/or Gaussian distributed. Unlike these methods, in this article we present an ultrasound-specific segmentation approach that addresses both the spatial correlation of the data as well as its intensity distribution. We first decorrelate the image and then apply a region-based active contour whose motion is derived from an appropriate parametric distribution for maximum likelihood image segmentation. We consider zero-mean complex Gaussian, Rayleigh, and Fisher-Tippett flows, which are designed to model fully formed speckle in the in-phase/quadrature (IQ), envelope detected, and display (log compressed) images, respectively. We present experimental results demonstrating the effectiveness of our method and compare the results with other parametric and nonparametric active contours. (E-mail:greg.slabaugh@gmail.com)     

An Implanted Closed-loop Chip System for Heart Rate Control: System Design and Effects in Conscious Rats

Objective

To evaluate the efficiency of an implanted chip system for the control of heart rate (HR).

Methods

The HR was recorded in six conscious Sprague-Dawley (SD) rats. An implanted chip system was designed to regulate the HR by stimulating the right cervical vagus nerve according to the feedback of real time HR. Each rat was subjected to 30-min regulation and 30-min recovery. The change of HR during the regulation period was compared with the control. The ECG was recorded during the experiment for 24 h.

Results

The ECG signals were successfully recorded during the experiment. The HR was significantly decreased during the period of regulation compared with control (-79.3 ±34.5, P < 0.01, n = 6) and then recovered to normal after regulation.

Conclusion

The described implanted chip system can regulate the HR to a designated set point.     

Practical tips and tricks for the measurement of fractional flow reserve

Coronary pressure measurement has emerged as one of the most promising tool to assist interventional cardiologist to make accurate clinical decisions. Fractional flow reserve (FFR) is a simple way of reliably assessing the functional consequences of coronary atherosclerosis. The training in FFR is easy, and coronary pressure measurements can be obtained swiftly in the catheterization laboratory. This review outlines the practical set up of FFR in the catheterization laboratory and also discusses the potential pitfalls in the measurement of FFR. © 2010 Wiley‐Liss, Inc.     

一种基于粗集理论的遗传分类算法

本文提出了一种基于粗集理论的遗传分类算法,该算法可以无需任何辅助信息,只根据数据自身提供的信息对数据进行简化,提取有用的特征,并求得相应的规则.同时,还提出了一种基于属性重要度的分辨矩阵简化方法,该方法可提高对条件属性的约简效率.