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81.
M E MacDonald A Novelletto C Lin D Tagle G Barnes G Bates S Taylor B Allitto M Altherr R Myers 《Nature genetics》1992,1(2):99-103
Analysis of 78 Huntington's disease (HD) chromosomes with multi-allele markers revealed 26 different haplotypes, suggesting a variety of independent HD mutations. The most frequent haplotype, accounting for about one third of disease chromosomes, suggests that the disease gene is between D4S182 and D4S180. However, the paucity of an expected class of chromosomes that can be related to this major haplotype by assuming single crossovers may reflect the operation of other mechanisms in creating haplotype diversity. Some of these mechanisms sustain alternative scenarios that do not require a multiple mutational origin for HD and/or its positioning between D4S182 and D4S180. 相似文献
82.
MacArthur DG Seto JT Raftery JM Quinlan KG Huttley GA Hook JW Lemckert FA Kee AJ Edwards MR Berman Y Hardeman EC Gunning PW Easteal S Yang N North KN 《Nature genetics》2007,39(10):1261-1265
More than a billion humans worldwide are predicted to be completely deficient in the fast skeletal muscle fiber protein alpha-actinin-3 owing to homozygosity for a premature stop codon polymorphism, R577X, in the ACTN3 gene. The R577X polymorphism is associated with elite athlete status and human muscle performance, suggesting that alpha-actinin-3 deficiency influences the function of fast muscle fibers. Here we show that loss of alpha-actinin-3 expression in a knockout mouse model results in a shift in muscle metabolism toward the more efficient aerobic pathway and an increase in intrinsic endurance performance. In addition, we demonstrate that the genomic region surrounding the 577X null allele shows low levels of genetic variation and recombination in individuals of European and East Asian descent, consistent with strong, recent positive selection. We propose that the 577X allele has been positively selected in some human populations owing to its effect on skeletal muscle metabolism. 相似文献
83.
R. Cavelti 《Cellular and molecular life sciences : CMLS》1948,4(12):487-489
Summary (1) Doubly refracting lipoid droplets can be demonstrated in normal and pathological sera by means of alcohol ether extraction. This is not possible with ether extraction alone.(2) These lipoid droplets can be demonstrated only, or almost only, when they are precipitated out of alcohol or ether alcohol 相似文献
84.
Larrucea S Butta N Rodriguez RB Alonso-Martin S Arias-Salgado EG Ayuso MS Parrilla R 《Cellular and molecular life sciences : CMLS》2007,64(22):2965-2974
Podocalyxin (PODXL) is a mucin protein of the CD34 family expressed in kidney glomerular podocytes, vascular endothelium,
progenitor bone marrow and tumor cells. It is assumed that PODXL plays an anti-adherent role in kidney podocytes. CHO cells
stably expressing human PODXL (CHO-PODXL) or human tumor cells (Tera-1) inherently expressing PODXL showed increased adherence
to platelets. The adherence of cells was inhibited (70%) by blockers of platelet P-selectin, prevented by the soluble ectodomain
of human PODXL (PODXL-Δ) or by the arginine-glycine-aspartate (RGDS) peptide and partially impeded by inhibition of integrin
αVβ3/αVβ5, suggesting a coordinated action of P-selectin and integrins. Colocalization of platelet P-selectin and PODXL expressed
on CHO cells was demonstrated by confocal immunofluorescence. No adherence to platelets was observed when PODXL was expressed
in glycomutant CHO cells deficient in sialic acid.
Received 14 August 2007; received after revision 12 September 2007; accepted 13 September 2007 相似文献
85.
86.
LANE RE 《Advancement of science》1948,5(18):96-118
87.
88.
概化理论是一种发展较晚但功能全面的现代测试理论,能有效地设计、分析和评估测试项目。直到上个世纪八九十年代,Robert Brennan等人开发了GENOVA等一系列应用软件后,概化理论才在心理和教育测量领域的研究中逐渐受到重视,此后,运用概化理论研究实际问题的项目也逐渐多了起来。概化理论与项目反应理论属于不同的理论范畴,它们的基本假设也有很大的差别。 相似文献
89.
Aldose reductase and aldehyde reductase belong to the aldo-keto reductase superfamily of enzymes whose members are responsible
for a wide variety of biological functions. Aldose reductase has been identified as the first enzyme involved in the polyol
pathway of glucose metabolism which converts glucose into sorbitol. Glucose over-utilization through the polyol pathway has
been linked to tissue-based pathologies associated with diabetes complications, which make the development of a potent aldose
reductase inhibitor an obvious and attractive strategy to prevent or delay the onset and progression of the complications.
Structural studies of aldose reductase and the homologous aldehyde reductase in complex with inhibitor were carried out to
explain the difference in the potency of enzyme inhibition. The aim of this review is to provide a comprehensive summary of
previous studies to aid the development of aldose reductase inhibitors that may have less toxicity problems than the currently
available ones.
Received 4 December 2006; received after revision 12 February 2007; accepted 20 April 2007 相似文献
90.