不同性别急性心梗患者的临床特征及院内治疗预后分析

目的:观察首次确诊为急性心肌梗死(AMI)患者的临床特征并分析不同性别人群的在入院治疗及院内短期预后的差异。方法:回顾性分析2010年2月至2012年4月在沈阳军区总医院心内科初次确诊为AMI的患者271例,并按性别分为两组,其中男性组180例,女性组91例,统计其临床特征、入院后的药物和手术治疗情况,以及院内并发症及预后情况,分析总结两组患者各自的特点和差异。结果:女性患者的年龄要大于男性患者(63±14vs71±11,P0.001),且同时更易患有高血压等心血管疾病合并症(73.3%vs 58.2%,P0.05)。女性患者的发病至入院治疗时间长于男性(P0.001),且入院后行PCI治疗的比例要明显低于男性患者(67%vs 79.4%,P0.05)。初步分析结果表明,女性患者的院内死亡率高于男性(11%vs 3.3%,OR:3.11,95%CI:1.53-7.15),但排除不均衡因素的影响后,男女患者的院内死亡率无明显差异(OR:2.11,95%CI:0.68-5.12)。结论:两性AMI患者的临床特征、入院后治疗及院内短期预后均存在一定差异。根据女性患者的临床特征和院内治疗及预后的现状,应进一步加强对女性高危人群的冠心病诊治知识普及和教育,且对入院后的女性患者应采取更为积极的药物和介入手术治疗手段,以改善预后。     

Machine learning approaches in MALDI-MSI: clinical applications

Introduction: Despite the unquestionable advantages of Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry Imaging in visualizing the spatial distribution and the relative abundance of biomolecules directly on-tissue, the yielded data is complex and high dimensional. Therefore, analysis and interpretation of this huge amount of information is mathematically, statistically and computationally challenging.

Areas covered: This article reviews some of the challenges in data elaboration with particular emphasis on machine learning techniques employed in clinical applications, and can be useful in general as an entry point for those who want to study the computational aspects. Several characteristics of data processing are described, enlightening advantages and disadvantages. Different approaches for data elaboration focused on clinical applications are also provided. Practical tutorial based upon Orange Canvas and Weka software is included, helping familiarization with the data processing.

Expert commentary: Recently, MALDI-MSI has gained considerable attention and has been employed for research and diagnostic purposes, with successful results. Data dimensionality constitutes an important issue and statistical methods for information-preserving data reduction represent one of the most challenging aspects. The most common data reduction methods are characterized by collecting independent observations into a single table. However, the incorporation of relational information can improve the discriminatory capability of the data.     

凝溶胶蛋白基因的生物学功能及其应用研究进展

凝溶胶蛋白(gelsolin,GSN)是Gelsolin/Villin超家族的核心成员,是一种多功能的钙依赖性肌动蛋白结合蛋白,在细胞中Ca^2+和PIP2等多因素的调控下,对细胞凋亡、吞噬功能、肌动蛋白微丝切割、细胞信号转导等方面起着重要的作用。近年来,凝溶胶蛋白还被频繁用于相关疾病的预防、诊断与治疗,但其在调控细胞凋亡、炎症等病理生理中的作用机制还存在些许争议。本研究综述了凝溶胶蛋白的结构特点、生物学功能以及对疾病的诊断和治疗,旨在了解凝溶胶蛋白在生物医学及动物科学等领域的应用以及未来凝溶胶蛋白的发展前景。     

基于序列特征的环状RNA识别

环状RNA是新发现的一类具有重要生物学功能的RNA。现有的环状RNA识别工具依赖高通量测序数据,因数据本身和识别方式的弊端而普遍存在准确性不足、不同方法间重复性低以及假阳性率/假阴性率高等缺点。为了解决该问题,我们搭建模型来实现不依赖于测序数据而根据序列的内在特征的环状RNA从头预测。本文选取了包括剪接位点上下游内含子的长度、A-to-I密度和Alu重复序列等100个与RNA成环相关的序列特征,建立了机器学习模型,并识别了人类基因组中的环状RNA,比较了两种机器学习方法随机森林法(RF)和支持向量机(SVM)的分类效果。结果表明,所选序列特征能有效地鉴别RNA能否成环,同时,不同序列特征对模型的分类预测能力的贡献也不同。相比于SVM方法,RF分类的效果更好。     

两种过滤特征基因选择算法的有效性研究

对基因表达谱进行特征基因选择不仅能改善疾病分类方法的效能,而且为寻找与疾病相关的特征基因提供新的途径．通过比较用调整p值的t检验、非参数评分两种特征基因选择算法后和未进行选择时支持向量机(SVM)分类器的分类性能、支持向量(SV)的吻合度、错分样本ID的吻合度和对样本均匀翻倍后的稳定性．结果发现：特征选择后线性、核函数为二阶多项式和径向基的SVM分类性能明显提高;特征选择前后的SV及错分样本ID的吻合度均较高;SVM的稳定性较好．由此得出结论：这两种特征选择算法具有一定的有效性．     

Molecular classification of cancer types from microarray data using the combination of genetic algorithms and support vector machines

Simultaneous multiclass classification of tumor types is essential for future clinical implementations of microarray-based cancer diagnosis. In this study, we have combined genetic algorithms (GAs) and all paired support vector machines (SVMs) for multiclass cancer identification. The predictive features have been selected through iterative SVMs/GAs, and recursive feature elimination post-processing steps, leading to a very compact cancer-related predictive gene set. Leave-one-out cross-validations yielded accuracies of 87.93% for the eight-class and 85.19% for the fourteen-class cancer classifications, outperforming the results derived from previously published methods.     

Hydraulic conductivities of competing root systems of Grevillea robustaand maize in agroforestry

Models of water uptake in mixed stands of vegetation commonly assume that water is partitioned among competing root systems in proportion to relative root length densities. Such an approach assumes implicitly that roots of different species have equivalent hydraulic properties. This was tested for root systems of Grevillea robustaA. Cunn. and maize (Zea maysL.) at a semi-arid site in Kenya. The hydraulic conductances for roots of both species were measured in situat the scale of the whole root or root system using a high pressure flow meter (HPFM). Hydraulic conductivities (_r) were expressed per unit root length. Root lengths were estimated for maize plants by soil coring and for G. robustausing a fractal branching model calibrated against soil coring. Mean _r was 1.88×10^–7 ±0.28×10^–7kg s^–1 MPa^–1 m^–1 for G. robustaand 1.25×10^–7 ±0.13×10^–7kg s^–1 MPa^–1 m^–1 for maize. Values of _r were not significantly different (P<0.05), suggesting that the assumption of hydraulic equivalence for root systems of the two species may be valid, at least when hydrostatic gradients are the major driving force for water uptake. Differences in conductivities between these species could arise, however, because of variation in the hydraulic properties of roots not accounted for here, for example because of root age, phenology or responses to the soil environment.     

浙江天台山甜槠群落研究

以分布在浙江省天台山的甜储群落为对象,分析了群落的特征和性质。甜储群落中,甜储的优势突出,呈单优势群落。群落垂直结构复杂,可分为乔木层、灌木层、草本层,亦有一定数量的层间植物。乔木层的物种多样性指数偏低,这与特定生境所形成的单优势群落有关。各样地间的植物种类具有较高的相似性,群落内种类组成相对一致。群落内优势种群甜储、木荷的年龄结构属稳定型或增长型,它们在各样地的分布格局均呈集群分布。     

Haplorchis taichui as a Possible Etiologic Agent of Irritable Bowel Syndrome-Like Symptoms

The aim of this study is to clarify the clinical features of Haplorchis taichui infection in humans in Nan Province, Thailand, and to correlate the clinical features with irritable bowel syndrome (IBS)-like symptoms. In this study area, only H. taichui, but neither other minute intestinal flukes nor small liver flukes were endemic. The degree of infection was determined by fecal egg counts and also by collecting adult worms after deworming. The signs and symptoms of individual patients together with their hematological and biochemical laboratory data were gathered to evaluate the relationship between the clinical features and the severity of infection. Special emphasis was made to elucidate the possible similarities of the clinical features of H. taichui infection and IBS-like symptoms. The results showed useful clinical information and the significant (> 50%) proportion of haplorchiasis patients complained of abdominal pain, lassitude, and flatulence, which were the important diagnostic symptoms of IBS. This study has reported a possible link between H. taichui and IBS, and H. taichui might probably play a role in the etiology of these IBS-like symptoms.