排序方式: 共有33条查询结果,搜索用时 31 毫秒
21.
22.
23.
24.
Seiwert SD 《Parasitology today (Personal ed.)》1995,11(10):362-368
Over 30 million people in tropical regions suffer from Chagas disease, African sleeping sickness or leishmaniasis. The causative agents of these diseases, flagellated protozoa collectively known as kinetoplastids, represent an ancient lineage of eukaryotes. These unusual organisms carry out a large number of unique biochemical processes, one striking example being the sequence editing of mitochondrial messenger RNAs. In this review, Scott Seiwert focuses on recent studies that examine the reaction mechanism, molecular machinery and evolutionary history of this unusual RNA processing reaction. 相似文献
25.
Yu-Chung Chiang Kuo-Hsiang Hung Shann-Jye Moore Xue-Jun Ge Shong Huang Tsai-Wen Hsu Barbara A Schaal TY Chiang 《BMC evolutionary biology》2009,9(1):161
Background
This study addresses the apportionment of genetic diversity between Cycas revoluta and C. taitungensis, species that constitute the section Asiorientales and represent a unique, basal lineage of the Laurasian genus Cycas. Fossil evidence indicates divergence of the section from the rest of Cycas at least 30 million years ago. Geographically, C. taitungensis is limited to Taiwan whereas C. revoluta is found in the Ryukyu Archipelago and on mainland China. 相似文献26.
国际植物学墨尔本大会上命名法规的变化 总被引:1,自引:0,他引:1
2011年7月在第18届国际植物学大会命名法分会上通过了命名法规的一系列重大改动,并在全体大会上得到了接受批准。文中就命名法规的变化进行了简单概述,同时也讨论了这些变化的意义,特别是对菌物研究的意义,以期引起广大研究人员的关注。 相似文献
27.
Vaish NK Jadhav VR Kossen K Pasko C Andrews LE McSwiggen JA Polisky B Seiwert SD 《RNA (New York, N.Y.)》2003,9(9):1058-1072
We describe a strategy for the ultra-sensitive detection of nucleic acids using "half" ribozymes that are devoid of catalytic activity unless completed by a trans-acting target nucleic acid. The half-ribozyme concept was initially demonstrated using a construct derived from a multiple turnover Class I ligase. Iterative RNA selection was carried out to evolve this half-ribozyme into one activated by a conserved sequence present in the hepatitis C virus (HCV) genome. Following sequence optimization of substrate RNAs, this HCV-activated half-ribozyme displayed a maximal turnover rate of 69 min(-1) (pH 8.3) and was induced in rate by approximately 2.6 x 10(9)-fold by the HCV target. It detected the HCV target oligonucleotide in the zeptomole range (6700 molecules), a sensitivity of detection roughly 2.6 x 10(6)-fold greater than that previously demonstrated by oligonucleotide-activated ribozymes, and one that is sufficient for molecular diagnostic applications. 相似文献
28.
Vaish NK Dong F Andrews L Schweppe RE Ahn NG Blatt L Seiwert SD 《Nature biotechnology》2002,20(8):810-815
An allosteric hammerhead ribozyme activated specifically by the unphosphorylated form of the protein kinase ERK2 was created through a rational design strategy that relies on molecular recognition of ERK2 to decrease the formation of an alternate, inactive ribozyme conformer. Neither closely related mitogen-activated protein kinases (MAPKs) nor the phosphorylated form of ERK2 induced ribozyme activity. The ribozyme quantitatively detected ERK2 added to mammalian cell lysates and also functioned quantitatively in a multiplexed solution-phase assay. This same strategy was used to construct a second ribozyme selectively activated by the phosphorylated (active) form of ERK2. This approach is generally applicable to the development of ribozymes capable of monitoring post-translational modification of specific proteins. 相似文献
29.
Yang X Regan K Huang Y Zhang Q Li J Seiwert TY Cohen EE Xing HR Lussier YA 《PLoS computational biology》2012,8(1):e1002350
Gene expression signatures that are predictive of therapeutic response or prognosis are increasingly useful in clinical care; however, mechanistic (and intuitive) interpretation of expression arrays remains an unmet challenge. Additionally, there is surprisingly little gene overlap among distinct clinically validated expression signatures. These “causality challenges” hinder the adoption of signatures as compared to functionally well-characterized single gene biomarkers. To increase the utility of multi-gene signatures in survival studies, we developed a novel approach to generate “personal mechanism signatures” of molecular pathways and functions from gene expression arrays. FAIME, the Functional Analysis of Individual Microarray Expression, computes mechanism scores using rank-weighted gene expression of an individual sample. By comparing head and neck squamous cell carcinoma (HNSCC) samples with non-tumor control tissues, the precision and recall of deregulated FAIME-derived mechanisms of pathways and molecular functions are comparable to those produced by conventional cohort-wide methods (e.g. GSEA). The overlap of “Oncogenic FAIME Features of HNSCC” (statistically significant and differentially regulated FAIME-derived genesets representing GO functions or KEGG pathways derived from HNSCC tissue) among three distinct HNSCC datasets (pathways:46%, p<0.001) is more significant than the gene overlap (genes:4%). These Oncogenic FAIME Features of HNSCC can accurately discriminate tumors from control tissues in two additional HNSCC datasets (n = 35 and 91, F-accuracy = 100% and 97%, empirical p<0.001, area under the receiver operating characteristic curves = 99% and 92%), and stratify recurrence-free survival in patients from two independent studies (p = 0.0018 and p = 0.032, log-rank). Previous approaches depending on group assignment of individual samples before selecting features or learning a classifier are limited by design to discrete-class prediction. In contrast, FAIME calculates mechanism profiles for individual patients without requiring group assignment in validation sets. FAIME is more amenable for clinical deployment since it translates the gene-level measurements of each given sample into pathways and molecular function profiles that can be applied to analyze continuous phenotypes in clinical outcome studies (e.g. survival time, tumor volume). 相似文献
30.
Tanguy Y. Seiwert XiaoZhe Wang Jana Heitmann Vivian Villegas-Bergazzi Kam Sprott Stephen Finn Esther O'Regan Allan D. Farrow Ralph R. Weichselbaum Mark W. Lingen Ezra E. W. Cohen Kerstin Stenson David T. Weaver Everett E. Vokes 《PloS one》2014,9(7)