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111.
Antonin Holy Ivan Rosenberg Hana Dvofakova Erik Declercq 《Nucleosides, nucleotides & nucleic acids》2013,32(5-6):667-670
Abstract Acyclic nucleotide analogs derived from antiviral 9-(2-phosphonylmethoxyethyl)adenine by modification at the side chain or by alternation of the heterocyclic base were synthesized and investigated for their antiviral activity. 相似文献
112.
Pavol Kois Zdenek Tocik Maria Spassova Wu-Yun Ren Ivan Rosenberg Jaume Farras Soler 《Nucleosides, nucleotides & nucleic acids》2013,32(10):1093-1109
Abstract In order to find the effects of unnatural nucleosides on the stability of duplex, several oligonucleotides containing 1-(2-deoxy-2-fluoro-β-D-arabinofuranosyl)-uracil(FAU),-cytosine (FAC) and -thymine (FMAU) were synthesized by two alternative approaches: phosphoramidite method on an ABI 392 synthesizer and H-phosphonate procedure on our GeneSyn I universal module synthesizer. It was shown from the melting profiles that the presence of FMAU has a large stabilizing effect on the duplex. Replacement of thymidine with FAU, or deoxycytidine with FAC resulted in the formation of less stable duplexes. Temperature-dependent CD spectroscopy demonstrated that the structures of the fluorine containing oligomers are very similar to those of unmodified oligomers. 相似文献
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114.
Ivan Sabath Aleksandra Skrajna Xiao-cui Yang Micha? Dadlez William F. Marzluff Zbigniew Dominski 《RNA (New York, N.Y.)》2013,19(12):1726-1744
3′-End cleavage of animal replication-dependent histone pre-mRNAs is controlled by the U7 snRNP. Lsm11, the largest component of the U7-specific Sm ring, interacts with FLASH, and in mammalian nuclear extracts these two proteins form a platform that recruits the CPSF73 endonuclease and other polyadenylation factors to the U7 snRNP. FLASH is limiting, and the majority of the U7 snRNP in mammalian extracts exists as a core particle consisting of the U7 snRNA and the Sm ring. Here, we purified the U7 snRNP from Drosophila nuclear extracts and characterized its composition by mass spectrometry. In contrast to the mammalian U7 snRNP, a significant fraction of the Drosophila U7 snRNP contains endogenous FLASH and at least six subunits of the polyadenylation machinery: symplekin, CPSF73, CPSF100, CPSF160, WDR33, and CstF64. The same composite U7 snRNP is recruited to histone pre-mRNA for 3′-end processing. We identified a motif in Drosophila FLASH that is essential for the recruitment of the polyadenylation complex to the U7 snRNP and analyzed the role of other factors, including SLBP and Ars2, in 3′-end processing of Drosophila histone pre-mRNAs. SLBP that binds the upstream stem–loop structure likely recruits a yet-unidentified essential component(s) to the processing machinery. In contrast, Ars2, a protein previously shown to interact with FLASH in mammalian cells, is dispensable for processing in Drosophila. Our studies also demonstrate that Drosophila symplekin and three factors involved in cleavage and polyadenylation—CPSF, CstF, and CF Im—are present in Drosophila nuclear extracts in a stable supercomplex. 相似文献
115.
Marina P. Arbetman Ivan Meeus Carolina L. Morales Marcelo A. Aizen Guy Smagghe 《Biological invasions》2013,15(3):489-494
The worldwide trade in bumblebees can lead to the spread of diseases, which in turn has been claimed as a factor in bumblebee decline. Populations of the introduced Bombus terrestris, which invaded NW Patagonia, Argentina, in 2006, harbor the highly pathogenic protozoan Apicystis bombi. We asked whether A. bombi had been co-introduced with B. terrestris, and if so, whether spillover occurred to the two resident bumblebee species in the region: the introduced European Bombus ruderatus and the native Bombus dahlbomii. We searched for A. bombi by means of PCR in samples of B. ruderatus and B. dahlbomii collected before and after the invasion of B. terrestris and in samples of the latter. We found no A. bombi in samples of B. ruderatus and B. dahlbomii collected before B. terrestris invasion, whereas post invasion, A. bombi was present in all 3 species. The identity of the parasite was established by sequencing the 18S region, which was identical for the three bumblebee species and also matched the European sequence, confirming it to be A. bombi. This is the first report of A. bombi in B. ruderatus and B. dahlbomii. Moreover, our results suggest that Patagonia had been free of A. bombi until this parasite was co-introduced with B. terrestris, and spilled over in situ to these two previously resident species. Finally, our findings provide indirect circumstantial evidence of a potential link between the population collapse and geographic retraction of B. dahlbomii and the introduction of this novel parasite. 相似文献
116.
Ivan Literák Petr Heneberg Jiljí Sitko Eric J. Wetzel Jorge Manuel Cardenas Callirgos Miroslav Čapek Daniel Valle Basto Ivo Papoušek 《Parasitology international》2013,62(4):390-396
Until now, four species of eye trematodes have been found in South America. Of them, Philophthalmus lucipetus (synonymized with Philophthalmus gralli) displays a broad host spectrum, with at least 30 bird species (prevalently large water birds), five mammal species and humans serving as definitive hosts, and with snails Fagotia (Microcolpia) acicularis, Amphimelania holandri, Melanopsis praemorsa and Melanoides tuberculata serving as intermediate hosts. When examining a total of 50 birds of ten species in the wetland of Pantanos de Villa, Lima, Peru in July 2011, eye trematodes were identified visually in the edematous conjunctival sac of 11 (48%) out of 23 resident many-colored rush tyrants Tachuris rubrigastra. Based on morphometric characteristics, the trematodes were identified as P. lucipetus. ITS2 and CO1 gene of the examined specimens combined showed a 99% similarity to an Iranian isolate of Philophthalmus sp. from the intermediate host Melanoides tuberculata, an invasive freshwater snail, suggesting that these two isolates represent the same species with a wide geographical range. Moreover, the prevalence of infection with the philophthalmid cercariae was 31% in 744 Melanoides tuberculata examined in Pantanos de Villa in 2010. It is evident that P. lucipetus occurs throughout the world as well as locally, including Eurasia and South America. Here we report this trematode for the first time in Peru, and we were the first to sequence any of the South American eye trematodes. Low host specificity of P. lucipetus and the invasive character of Melanoides tuberculata as a competent intermediate host suggest that eye trematodosis caused by P. lucipetus may emerge frequently in various parts of the world, especially in the tropics. Increase of the zoonotic potential of the P. lucipetus associated with this invasive snail spreading across the world is predictable and should be of interest for further research. 相似文献
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118.
Natalia A. Kuzmina Philippe Lemey Ivan V. Kuzmin Bonny C. Mayes James A. Ellison Lillian A. Orciari Dillon Hightower Steven T. Taylor Charles E. Rupprecht 《PloS one》2013,8(12)
The south-central skunk rabies virus (SCSK) is the most broadly distributed terrestrial viral lineage in North America. Skunk rabies has not been efficiently targeted by oral vaccination campaigns and represents a natural system of pathogen invasion, yielding insights to rabies emergence. In the present study we reconstructed spatiotemporal spread of SCSK in the whole territory of its circulation using a combination of Bayesian methods. The analysis based on 241 glycoprotein gene sequences demonstrated that SCSK is much more divergent phylogenetically than was appreciated previously. According to our analyses the SCSK originated in the territory of Texas ~170 years ago, and spread geographically during the following decades. The wavefront velocity in the northward direction was significantly greater than in the eastward and westward directions. Rivers (except the Mississippi River and Rio Grande River) did not constitute significant barriers for epizootic spread, in contrast to deserts and mountains. The mean dispersal rate of skunk rabies was lower than that of the raccoon and fox rabies. Viral lineages circulate in their areas with limited evidence of geographic spread during decades. However, spatiotemporal reconstruction shows that after a long period of stability the dispersal rate and wavefront velocity of SCSK are increasing. Our results indicate that there is a need to develop control measures for SCSK, and suggest how such measure can be implemented most efficiently. Our approach can be extrapolated to other rabies reservoirs and used as a tool for investigation of epizootic patterns and planning interventions towards disease elimination. 相似文献
119.
Emma Louise Clifford Margaret M. Collins Claire M. Buckley Anthony P. Fitzgerald Ivan J. Perry 《PloS one》2013,8(12)
Objectives
To study the determinants of health-related quality of life (HRQoL) in Irish patients with diabetes using the Centres for Disease Controls'' (CDC''s) ‘Unhealthy Days’ summary measure and to assesses the agreement between this generic HRQoL measure and the disease-specific Audit of Diabetes Dependant Quality of Life (ADDQoL) measure.Research Design and Methods
Data were analysed from the Diabetes Quality of Life Study, a cross-sectional study of 1,456 people with diabetes in Ireland (71% response rate). Unhealthy days were assessed using the CDC''s ‘Unhealthy days’ summary measure. Quality of life (QoL) was also assessed using the ADDQoL measure. Analyses were conducted primarily using logistic regression. The agreement between the two QoL instruments was measured using the kappa co-efficient.Results
Participants reported a median of 2 unhealthy days per month. In multivariate analyses, female gender (P = 0.001), insulin use (P = 0.030), diabetes complications (P = <0.001) were significantly associated with more unhealthy days. Older patients had fewer unhealthy days per month (P = 0.003). Agreement between the two measures of QoL (unhealthy days measure and ADDQoL) was poor, Kappa = 0.234Conclusions
The findings highlight the determinants of HRQoL in patients with diabetes using a generic HRQoL summary measure. The ‘Unhealthy Days’ and the ADDQoL have poor agreement, therefore the ‘Unhealthy Days’ summary measure may be assessing a different construct. Nonetheless, this study demonstrates that the generic ‘Unhealthy Days’ summary measure can be used to detect determinants of HRQoL in patients with diabetes. 相似文献120.
Codon usage bias (CUB) results from the complex interplay between translational selection and mutational biases. Current methods for CUB analysis apply heuristics to integrate both components, limiting the depth and scope of CUB analysis as a technique to probe into the evolution and optimization of protein-coding genes. Here we introduce a self-consistent CUB index (scnRCA) that incorporates implicit correction for mutational biases, facilitating exploration of the translational selection component of CUB. We validate this technique using gene expression data and we apply it to a detailed analysis of CUB in the Pseudomonadales. Our results illustrate how the selective enrichment of specific codons among highly expressed genes is preserved in the context of genome-wide shifts in codon frequencies, and how the balance between mutational and translational biases leads to varying definitions of codon optimality. We extend this analysis to other moderate and fast growing bacteria and we provide unified support for the hypothesis that C- and A-ending codons of two-box amino acids, and the U-ending codons of four-box amino acids, are systematically enriched among highly expressed genes across bacteria. The use of an unbiased estimator of CUB allows us to report for the first time that the signature of translational selection is strongly conserved in the Pseudomonadales in spite of drastic changes in genome composition, and extends well beyond the core set of highly optimized genes in each genome. We generalize these results to other moderate and fast growing bacteria, hinting at selection for a universal pattern of gene expression that is conserved and detectable in conserved patterns of codon usage bias. 相似文献