Stage IV malignant intrapericardial germ cell tumor: a case report

Fetal nucleated red cells which pass into the maternal circulation during pregnancy are a potential cell source for non-invasive prenatal genetic diagnosis. To sort these rare cells with a high degree of specificity, we focussed our attention on the erythropoietin receptor, a strictly erythroid-specific antigen. We first labelled these receptors with biotin-(sialyl)-erythropoietin, then isolated the erythroid cells by magnetic beads conjugated with streptavidin in a MiniMACS (magnetic cell separator). The effectiveness of this strategy for the enrichment of fetal cells was evaluated by assessing its accuracy for gender prediction in 18 male-bearing pregnancies. Polymerase chain reaction (PCR) results on maternal blood samples sorted for Epo-r and CD71 antigens displayed similar sensitivity (55% Epo-r, 61% CD71) in detecting Y-specific sequences while immunocytochemical studies on four maternal blood samples, sorted after increasing the binding time of the ligand to Epo-r (8 h), showed a substantial improvement in fetal cell recovery and purity. We conclude that sorting by Epo-r/biotin-(sialyl)-erythropoietin provides effective enrichment of fetal nucleated red cells allowing the possibility of direct prenatal cytogenetic analysis by multiprobe fluorescent in-situ hybridization (FISH).     

Solution structure of recombinant human interleukin-6

Interleukin-6 (IL-6) is a 185 amino acid cytokine which exerts multiple biological effects in vivo and whose dysregulation underlies several disease processes. The solution structure of recombinant human interleukin-6 has now been determined using heteronuclear three and four-dimensional NMR spectroscopy. The structure of the molecule was determined using 3044 distance and torsion restraints derived by NMR spectroscopy to generate an ensemble of 32 structures using a combined distance geometry/simulated annealing protocol. The protein contains five alpha-helices interspersed with variable-length loops; four of these helices constitute a classical four-helix bundle with the fifth helix located in the CD loop. There were no distance violations greater than 0.3 A in any of the final 32 structures and the ensemble has an average-to-the-mean backbone root-mean-square deviation of 0.50 A for the core four-helix bundle. Although the amino-terminal 19 amino acids are disordered in solution, the remainder of the molecule has a well defined structure that shares many features displayed by other long-chain four-helix bundle cytokines. The high-resolution NMR structure of hIL-6 is used to rationalize available mutagenesis data in terms of a heteromeric receptor complex.     

Regulation of nuclear factor-kappa B and its inhibitor I kappa B-alpha/MAD-3 in monocytes by Mycobacterium tuberculosis and during human tuberculosis

Blood monocytes from patients with active tuberculosis are activated in vivo, as evidenced by an increase in the stimulated release of proinflammatory cytokines, such as TNF-alpha, and the spontaneous expression of IL-2R. Further, monocytes from patients demonstrate an augmented susceptibility to a productive infection with HIV-1 in vitro. Mycobacterium tuberculosis and its components are strong signals to activate monocytes to production of cytokines. In this study we examined the basis of activation of monocytes during active tuberculosis and by M. tuberculosis. We found a constitutive degradation of I kappa B-alpha, the major cytoplasmic inhibitor of nuclear factor kappa B (NF-kappa B), in freshly isolated PBMC and monocytes from patients with tuberculosis. In contrast, I kappa B-alpha levels in PBMC and monocytes from healthy subjects or from patients with nontuberculous pulmonary conditions were intact. Further, by electrophoretic mobility shift assay, NF-kappa B was activated in monocytes from tuberculous patients. The expression of I kappa B-alpha gene, which is responsive to activation by NF-kappa B, was up-regulated in PBMC and monocytes from patients, but not in mononuclear cells from healthy subjects or those with nontuberculous lung diseases. By contrast, the expression of other adherence-associated early genes, such as IL-8 and IL-1 beta, was not up-regulated in PBMC of tuberculous patients. Further, M. tuberculosis and its tuberculin, purified protein derivative, induced the degradation of I kappa B-alpha and the expression of I kappa B-alpha mRNA, and purified protein derivative induced the activation of NF-kappa B in monocytes.     

Decrease in bladder cell micronucleus prevalence after intervention to lower the concentration of arsenic in drinking water

Epidemiological studies performed in Taiwan, Argentina, and Chile suggest that ingestion of arsenic (As) may cause bladder cancer. Because of these findings, we previously investigated the relationship between As ingestion and genetic damage to the urothelium in two cross-sectional biomarker studies, one in Nevada and one in Chile. In both studies, we found that increased levels of micronucleated cells (MNCs) in exfoliated bladder cells were associated with elevated concentrations of As in drinking water, suggesting that As induces genetic damage to bladder cells. To further investigate this relationship, we conducted an intervention study in a subset of highly exposed men (n = 34) from the cross-sectional study in Chile. Subjects whose usual source of water contained about 600 micrograms/liter As were supplied with water lower in As (45 micrograms/liter) for 8 weeks, allowing ample opportunity for renewal and exfoliation of bladder epithelial cells. Mean urinary As levels decreased during the intervention from 742 to 225 micrograms/liter. Bladder MNC prevalence also decreased from 2.63 MNCs/1000 cells preintervention to 1.79 MNCs/1000 cells postintervention (P < 0.05). When the analysis was limited to individuals previously having subcytotoxic urinary As levels (< 700 micrograms/liter), the change between pre- and postintervention MNC was more pronounced: the level decreased from 3.54 to 1.47 MNCs/1000 cells, respectively (P = 0.002). Among smokers, MNC prevalences decreased from 4.45 MNCs/1000 cells preintervention to 1.44 MNCs/1000 cells postintervention (P = 0.002). Among nonsmokers, the decrease was much smaller: 2.04 MNCs/1000 cells preintervention to 1.90 MNCs/1000 cells postintervention (P = 0.25), suggesting that smoker's bladder cells could be more susceptible to genotoxic damage caused by As. The reduction in bladder MNC prevalence with reduction in As intake provides further evidence that As is genotoxic to bladder cells.     

基于范围分割数据的负载平衡算法的研究*

基于范围分割提出了一个有效的、渐近的负载平衡算法,可确保在任意时间的存储平衡,理论分析证明了该方法的有效性。     

2010年上海世博会运行综合管理系统研究

从2010年上海世博会运行管理的需求出发,构建了运行综合管理的系统框架,研究了实现此功能框架的关键技术,包括子系统集成与协同工作方案、决策指挥控制的技术体系和管理体系、门户技术以及安全管理技术等。     

AODV中基于能量的簇头选择算法

为了解决无线自组网按需平面距离矢量路由协议(AODV)网络生存时间短、节点死亡率高的问题,通过对现有的簇头选择算法的分析并利用网络仿真软件(NS2)进行了大量的仿真模拟,提出了一种基于能量的簇头选择算法。该方法与现有的簇头选择算法最大的不同在于:它是通过在邻居节点中选择一个剩余能量最大的节点当做簇头,而不是根据节点的地理位置。为防止节点能量被过度的消耗设置了能量阈值,只有节点剩余能量大于该阈值的节点才能当做簇头,对于簇头节点规定了它所能管理的最大节点数。NS2仿真结果表明,该方法可以延长网络的生存时间,降低节点的死亡率。     

基于Solr的体育视频信息全文搜索研究

为解决体育网络视频搜索问题,提出一种基于Solr技术的体育视频信息全文搜索系统。收集和处理原始体育视频信息,使用Solr建立索引进行搜索,对搜索结果进行处理和呈现,给出应用系统的系统架构,介绍原始数据信息收集、Solr全文搜索服务、搜索结果预处理的过程。实验结果表明,该系统的命中率和正确率较高,当采用多类聚集方法时搜索效果更优。     

遗传算法在求解最小生成树中的运用

以图论和遗传算法为基础,提出了求解最小生成树问题的遗传算法。该算法解决了常用二进制编码不能正确表达最小生成树的问题,利用Prufer数对生成树进行编码;在遗传操作中对变异算子进行了改进,避免了由于变异产生大量不可行解。从而提高了遗传算法的效率;通过数值试验,表明该算法简单,高效,收敛率高。