排序方式: 共有102条查询结果,搜索用时 31 毫秒
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Amegbey G Chang Z Stothard P Yee A Arrowsmith C Wishart DS 《Journal of biomolecular NMR》2004,30(4):459-460
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The Evolutionary History of the Genus Acanthamoeba and the Identification of Eight New 18S rRNA Gene Sequence Types 总被引:6,自引:0,他引:6
Diane R. Stothard Jill M. Schroeder-Diedrich Mohammad H. Awwad Rebecca J. Gast Dolena R. Ledee Salvador Rodriguez-Zaragoza Chantal L. Dean Paul A. Fuerst Thomas J. Byers 《The Journal of eukaryotic microbiology》1998,45(1):45-54
ABSTRACT The 18S rRNA gene ( Rns ) phylogeny of Acanthamoeba is being investigated as a basis for improvements in the nomenclature and taxonomy of the genus. We previously analyzed Rns sequences from 18 isolates from morphological groups 2 and 3 and found that they fell into four distinct evolutionary lineages we called sequence types T1-T4. Here, we analyzed sequences from 53 isolates representing 16 species and including 35 new strains. Eight additional lineages (sequence types T5-T12) were identified. Four of the 12 sequence types included strains from more than one nominal species. Thus, sequence types could be equated with species in some cases or with complexes of closely related species in others. The largest complex, sequence type T4, which contained six closely related nominal species, included 24 of 25 keratitis isolates. Rns sequence variation was insufficient for full phylogenetic resolution of branching orders within this complex, but the mixing of species observed at terminal nodes confirmed that traditional classification of isolates has been inconsistent. One solution to this problem would be to equate sequence types and single species. Alternatively, additional molecular information will be required to reliably differentiate species within the complexes. Three sequence types of morphological group 1 species represented the earliest divergence in the history of the genus and, based on their genetic distinctiveness, are candidates for reclassification as one or more novel genera. 相似文献
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S. Wilkinson A. M. Emery I. S. Khamis A. F. Mgeni J. R. Stothard & D. Rollinson 《Journal of Zoology》2007,272(3):329-339
In Zanzibar, the freshwater hermaphroditic snail Bulinus globosus is the intermediate host of the human parasite Schistosoma haematobium . To shed light on the patterns of genetic variation within Bu. globosus , variation at six polymorphic microsatellite loci was assessed to quantify spatial genetic structure within eight populations and temporal changes in a further four populations of the snails. Limited genetic variation was observed within populations, possibly reflecting both partial-selfing and fluctuations in population size. Although a statistically significant heterozygote deficiency was observed, Bu. globosus appears to be a preferential out-crosser, which was consistent with the absence of genotypic linkage disequilibria. Genetic variation across populations was substantial, illustrating significant isolation-by-distance on a regional scale and that gene flow was restricted to nearby populations. The temporal survey showed that levels of genetic variation and inbreeding changed over a 1-year period, consistent with field observations of seasonal change. The results strongly support a snail demographic model of population expansion and contraction throughout the year with habitats re-colonized by aestivating or surviving snails from local refugia. This model might help explain co-evolution of snails and schistosomes in Zanzibar as local populations of Bu. globosus have varying degrees of susceptibility to S. haematobium . 相似文献
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Circular genome visualization and exploration using CGView 总被引:1,自引:0,他引:1
SUMMARY: CGView (Circular Genome Viewer) is a Java application and library for generating high-quality, zoomable maps of circular genomes. It converts XML or tab-delimited input into a graphical map (PNG, JPG or Scalable Vector Graphics format), complete with sequence features, labels, legends and footnotes. In addition to the default full view map, the program can generate a series of hyperlinked maps showing expanded views. The linked maps can be explored using any Web browser, allowing rapid genome browsing and facilitating data sharing. AVAILABILITY: CGView (the standalone application, library or applet), sample input, sample maps and documentation can be obtained from http://wishart.biology.ualberta.ca/cgview/ CONTACT: david.wishart@ualberta.ca. 相似文献
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As part of a urinary schistosomiasis control programme on Zanzibar, an aged cross-sectional survey of 305 children from three schools on Unguja was conducted to investigate the relationships between levels of excreted albumin and haemoglobin in urine and Schistosoma haematobium infection status. Diagnosis was determined by standard parasitological methods, dipstick reagents for microhaematuria, visual inspection for macrohaematuria as well as collection of case-history questionnaire data for self-diagnosis. Prevalence of infection as determined by parasitology was 53.9% and approximately, one quarter of the children examined were anaemic (<11 g dl(-1)). A statistically significant negative association of blood haemoglobin levels of boys and S. haematobium infection intensity status was observed (rs=-0.23, P=0.005). Through sensitivity analysis of urine-albumin values it was determined that a concentration of above >40 mg l(-1), as measured with the HemoCue urine-albumin photometer, had sensitivity, specificity, positive and negative predictive values of 0.90, 0.83, 0.86 and 0.89 respectively against 'gold-standard' parasitology. There was a clear association of reported pain upon micturition for children with elevated urine-albumin levels, with an odds ratio of 20 to 1. Levels of excreted blood in urine were quantified with the HemoCue Plasma/Low Hb photometer. However, dipsticks remain the method of choice for urine-haemoglobin of 0.1 g l(-1) and below. Urine parameters over a 24-h period were assessed in a small sub-sample. Reductions in both albumin and haemoglobin excretion were observed in 11 children 54 days after praziquantel treatment. It was concluded that these rapid, high-through-put, portable HemoCue assays could play a role in better describing and monitoring the occurrence, severity and evolution of urinary schistosomiasis disease. The urine-albumin assay has particular promise as a biochemical marker of S. haematobium induced kidney- and upper urinary tract-morbidity. 相似文献
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Stothard JR Lockyer AE Kabatereine NB Tukahebwa EM Kazibwe F Rollinson D Fenwick A 《Journal of helminthology》2004,78(3):281-284
During routine parasitological surveillance and monitoring activities within a National Control Programme for control of human schistosomiasis in Uganda, it was noted that cattle grazing in a water meadow immediately adjacent to Tonya primary school, where the prevalence of intestinal schistosomiasis in children was in excess of 90%, were unusually emaciated. To test the hypothesis that there may have been an anthropozoonotic focus of Schistosoma mansoni within the local herd, a young female heifer, clearly emaciated and c. 8 months old, was slaughtered from which schistosome worms were later recovered by dissection. As female worms inspected by microscopy were not gravid, morphological identification proved inconclusive but analysis of cytochrome oxidase subunit I (COI) and small subunit (SSU) ribosomal DNA sequences from these worms identified them as Schistosoma bovis Sonsino, 1876. This is the first substantiated report of S. bovis from Lake Albert, western Uganda. Further epidemiological surveys are needed to clarify the extent of bovine schistosomiasis within this region, particularly so since this lakeside plain has been earmarked as a future game reserve. 相似文献
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AW Solomon D Engels RL Bailey IM Blake S Brooker JX Chen JH Chen TS Churcher CJ Drakeley T Edwards A Fenwick M French AF Gabrielli NC Grassly EM Harding-Esch MJ Holland A Koukounari PJ Lammie J Leslie DC Mabey M Rhajaoui WE Secor JR Stothard H Wei AL Willingham XN Zhou RW Peeling 《PLoS neglected tropical diseases》2012,6(7):e1746
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Bonnie L. Webster Aiden M. Emery Joanne P. Webster Anouk Gouvras Amadou Garba Oumar Diaw Mohmoudane M. Seye Louis Albert Tchuem Tchuente Christopher Simoonga Joseph Mwanga Charles Lange Curtis Kariuki Khalfan A. Mohammed J. Russell Stothard David Rollinson 《PLoS neglected tropical diseases》2012,6(10)