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61.
Cancers arise owing to mutations in a subset of genes that confer growth advantage. The availability of the human genome sequence led us to propose that systematic resequencing of cancer genomes for mutations would lead to the discovery of many additional cancer genes. Here we report more than 1,000 somatic mutations found in 274 megabases (Mb) of DNA corresponding to the coding exons of 518 protein kinase genes in 210 diverse human cancers. There was substantial variation in the number and pattern of mutations in individual cancers reflecting different exposures, DNA repair defects and cellular origins. Most somatic mutations are likely to be 'passengers' that do not contribute to oncogenesis. However, there was evidence for 'driver' mutations contributing to the development of the cancers studied in approximately 120 genes. Systematic sequencing of cancer genomes therefore reveals the evolutionary diversity of cancers and implicates a larger repertoire of cancer genes than previously anticipated.  相似文献   
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S Tokuda  T Arrington  E H Goldberg  J Richey 《Nature》1977,267(5610):433-434
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The increased production of the 42 aminoacids long beta-amyloid (Aβ42) peptide has been established as a causal mechanism of the familial early onset Alzheimer’s disease (AD). In contrast, the causal mechanisms of the late-onset AD (LOAD), that affects most AD patients, remain to be established. Indeed, Aβ42 accumulation has been detected more than 30 years before diagnosis. Thus, the mechanisms that control Aβ accumulation in LOAD likely go awry long before pathogenesis becomes detectable. Early on, APOE4 was identified as the biggest genetic risk factor for LOAD. However, since APOE4 is not present in all LOAD patients, genome-wide association studies of thousands of LOAD patients were undertaken to identify other genetic variants that could explain the development of LOAD. PICALM, BIN1, CD2AP, SORL1, and PLD3 are now with APOE4 among the identified genes at highest risk in LOAD that have been implicated in Aβ42 production. Recent evidence indicates that the regulation of the endocytic trafficking of the amyloid precursor protein (APP) and/or its secretases to and from sorting endosomes is determinant for Aβ42 production. Thus, here, we will review the described mechanisms, whereby these genetic risk factors can contribute to the enhanced endocytic production of Aβ42. Dissecting causal LOAD mechanisms of Aβ42 accumulation, underlying the contribution of each genetic risk factor, will be required to identify therapeutic targets for novel personalized preventive strategies.  相似文献   
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Bacterial pathogens evolve during the infection of their human host(1-8), but separating adaptive and neutral mutations remains challenging(9-11). Here we identify bacterial genes under adaptive evolution by tracking recurrent patterns of mutations in the same pathogenic strain during the infection of multiple individuals. We conducted a retrospective study of a Burkholderia dolosa outbreak among subjects with cystic fibrosis, sequencing the genomes of 112 isolates collected from 14 individuals over 16 years. We find that 17 bacterial genes acquired nonsynonymous mutations in multiple individuals, which indicates parallel adaptive evolution. Mutations in these genes affect important pathogenic phenotypes, including antibiotic resistance and bacterial membrane composition and implicate oxygen-dependent regulation as paramount in lung infections. Several genes have not previously been implicated in pathogenesis and may represent new therapeutic targets. The identification of parallel molecular evolution as a pathogen spreads among multiple individuals points to the key selection forces it experiences within human hosts.  相似文献   
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LIVESTOCK PRODUCTION PLANNING UNDER ENVIRONMENTAL RISKS AND UNCERTAINTIES   总被引:9,自引:0,他引:9  
1. Introduction The world food economy is increasingly being driven by a shift of diets towards livestock products. In the developing countries, consumption of meat has been growing at 5-6 percent p.a., and that of milk and dairy products at 3.3-3.5 percent p.a. in the last few decades. Much of the growth is taking place in China (Huang and Zhang et al. 2003a, Huang and Liu 2003b, Keyzer and van Veen 2004, Ma and Huang et al. 2004, Simpson and Cheng et al.1994, USDA Economic Research Se…  相似文献   
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Russia is currently attempting to create a modern, innovative economy, which requires a new type of worker and a new, more cooperative style of management. Twenty years of Russian market reforms have clearly shown that one of the most serious obstacles to creating an innovative economy in Russia is to change the totalitarian style of thinking. A person needs to be considered as more than a means to achieve economic goals. This paper aims to describe some aspects of the social, economic and organizational changes occurring in Russia and one way out of the current predicament: using a constructivist approach to education in order to develop the innovative competencies of people. In this action research a presumption is made that changes in mentality and patterns of behavior are required for both managers and workers. Style of management in organizations should change in a manner that would support the creation of an innovative society.  相似文献   
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