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131.
Janoueix-Lerosey I Lequin D Brugières L Ribeiro A de Pontual L Combaret V Raynal V Puisieux A Schleiermacher G Pierron G Valteau-Couanet D Frebourg T Michon J Lyonnet S Amiel J Delattre O 《Nature》2008,455(7215):967-970
Neuroblastoma, a tumour derived from the peripheral sympathetic nervous system, is one of the most frequent solid tumours in childhood. It usually occurs sporadically but familial cases are observed, with a subset of cases occurring in association with congenital malformations of the neural crest being linked to germline mutations of the PHOX2B gene. Here we conducted genome-wide comparative genomic hybridization analysis on a large series of neuroblastomas. Copy number increase at the locus encoding the anaplastic lymphoma kinase (ALK) tyrosine kinase receptor was observed recurrently. One particularly informative case presented a high-level gene amplification that was strictly limited to ALK, indicating that this gene may contribute on its own to neuroblastoma development. Through subsequent direct sequencing of cell lines and primary tumour DNAs we identified somatic mutations of the ALK kinase domain that mainly clustered in two hotspots. Germline mutations were observed in two neuroblastoma families, indicating that ALK is a neuroblastoma predisposition gene. Mutated ALK proteins were overexpressed, hyperphosphorylated and showed constitutive kinase activity. The knockdown of ALK expression in ALK-mutated cells, but also in cell lines overexpressing a wild-type ALK, led to a marked decrease of cell proliferation. Altogether, these data identify ALK as a critical player in neuroblastoma development that may hence represent a very attractive therapeutic target in this disease that is still frequently fatal with current treatments. 相似文献
132.
133.
Long-billed curlew populations were studied in the upper Green River Basin of Wyoming. Sites were selected where curlew populations appear constant in numbers and declining in numbers. Results show that while few habitat differences were found between the two areas, disturbances such as grazing and dragging during nesting reduced productivity. Nest failures were also correlated with field fertilization and early season grazing. Within each area curlews nested successfully on field sites that were elevated and had adequate grass cover but not tall grass. 相似文献
134.
Jean Leclercq 《Cellular and molecular life sciences : CMLS》1946,2(4):145-146
Summary Experiments were carried out to test the effects of relative humidity on prepupae and pupae of the Silkworm,Bombyx mori L., at 250 C. It was found that:(1) duration of prepupal + pupal stages is the same at all relative humidities between 7 and 100%;(2) mortality seems unaffected in all these humidity conditions;(3) moths obtained in percentages between 55 and 100% R. H. have the same average wet weight; moths obtained under dryer conditions have a lower average weight (expressed in percentage of initial weights of prepupae);(4) pupae extracted from their cocoons develop as quickly and as well as pupae in their cocoons. 相似文献
135.
Eumeces capito Boucourt, 1879, is a senior synonym of Eumeces xanthi Günther, 1889. No exception to application of the Law of Priority is recommended in this case. The type locality of E. capito as originally published (“La côte oriental des Etats - Unis”) is erroneous. Undoubtedly the correct locality is China, but it is not restricted at present. 相似文献
136.
137.
Taylor TD Noguchi H Totoki Y Toyoda A Kuroki Y Dewar K Lloyd C Itoh T Takeda T Kim DW She X Barlow KF Bloom T Bruford E Chang JL Cuomo CA Eichler E FitzGerald MG Jaffe DB LaButti K Nicol R Park HS Seaman C Sougnez C Yang X Zimmer AR Zody MC Birren BW Nusbaum C Fujiyama A Hattori M Rogers J Lander ES Sakaki Y 《Nature》2006,440(7083):497-500
Chromosome 11, although average in size, is one of the most gene- and disease-rich chromosomes in the human genome. Initial gene annotation indicates an average gene density of 11.6 genes per megabase, including 1,524 protein-coding genes, some of which were identified using novel methods, and 765 pseudogenes. One-quarter of the protein-coding genes shows overlap with other genes. Of the 856 olfactory receptor genes in the human genome, more than 40% are located in 28 single- and multi-gene clusters along this chromosome. Out of the 171 disorders currently attributed to the chromosome, 86 remain for which the underlying molecular basis is not yet known, including several mendelian traits, cancer and susceptibility loci. The high-quality data presented here--nearly 134.5 million base pairs representing 99.8% coverage of the euchromatic sequence--provide scientists with a solid foundation for understanding the genetic basis of these disorders and other biological phenomena. 相似文献
138.
139.
This study is the foundation of a new interpretation of the introduction and the three first books of Diophantus’s Arithmetica, one that opens the way to a historically correct contextualization of the work. Its purpose, as indicated in the title,
is to renew the traditional discussion on the methods of problem-solving used by Diophantus, through the detailed exposition
of a new analytical framework that aims to give an account of the coherence and progressive nature of the material included
in the three first books of the Arithmetica. One outcome of this new ‘toolbox’ is a new conspectus of the problems and solutions contained in the latter, which is presented
in appendix. The first part of the article clarifies, as a necessary preliminary, the key notions and terminology underlying
our analysis. Among these new concepts is the notion of “method of invention,” which accounts in general for any way, by which
“positions” (hypostaseis) are used in the Arithmetica. The next part proposes a complete inventory of the various methods of invention found in the three first books. Finally
the last part presents the above mentioned conspectus and proposes a series of preliminary conclusions that can be drawn from
it. 相似文献
140.