排序方式: 共有65条查询结果,搜索用时 15 毫秒
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Mullany P Williams R Langridge GC Turner DJ Whalan R Clayton C Lawley T Hussain H McCurrie K Morden N Allan E Roberts AP 《Applied and environmental microbiology》2012,78(7):2147-2153
The insertion sites of the conjugative transposon Tn916 in the anaerobic pathogen Clostridium difficile were determined using Illumina Solexa high-throughput DNA sequencing of Tn916 insertion libraries in two different clinical isolates: 630ΔE, an erythromycin-sensitive derivative of 630 (ribotype 012), and the ribotype 027 isolate R20291, which was responsible for a severe outbreak of C. difficile disease. A consensus 15-bp Tn916 insertion sequence was identified which was similar in both strains, although an extended consensus sequence was observed in R20291. A search of the C. difficile 630 genome showed that the Tn916 insertion motif was present 100,987 times, with approximately 63,000 of these motifs located in genes and 35,000 in intergenic regions. To test the usefulness of Tn916 as a mutagen, a functional screen allowed the isolation of a mutant. This mutant contained Tn916 inserted into a gene involved in flagellar biosynthesis. 相似文献
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Vera Choinitzki Nadine Zwink Enrika Bartels Friederike Baudisch Thomas M. Boemers Alice Hölscher Salmai Turial Haitham Bachour Andreas Heydweiller Ralf Kurz Peter Bartmann Markus Pauly Ulrike Brokmeier Andreas Leutner Markus M. Nöthen Johannes Schumacher Ekkehart Jenetzky Heiko Reutter 《Birth defects research. Part A, Clinical and molecular teratology》2013,97(12):786-791
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Patrick Paulus Johannes Holfeld Anja Urbschat Haitham Mutlak Pia Alexandra Ockelmann Sabine Tacke Kai Zacharowski Christin Reissig David Stay Bertram Scheller 《PloS one》2013,8(8)
The lung is, more than other solid organs, susceptible for ischemia reperfusion injury after orthotopic transplantation. Corticosteroids are known to potently suppress pro-inflammatory processes when given in the post-operative setting or during rejection episodes. Whereas their use has been approved for these clinical indications, there is no study investigating its potential as a preservation additive in preventing vascular damage already in the phase of ischemia. To investigate these effects we performed orthotopic lung transplantations (LTX) in the rat. Prednisolone was either added to the perfusion solution for lung preservation or omitted and rats were followed for 48 hours after LTX. Prednisolone preconditioning significantly increased survival and diminished reperfusion edema. Hypoxia induced vasoactive cytokines such as VEGF were reduced. Markers of leukocyte invasiveness like matrix metalloprotease (MMP)-2, or common pro-inflammatory molecules like the CXCR4 receptor or the chemokine (C-C motif) ligand (CCL)-2 were downregulated by prednisolone. Neutrophil recruitment to the grafts was only increased in Perfadex treated lungs. Together with this, prednisolone treated animals displayed significantly reduced lung protein levels of neutrophil chemoattractants like CINC-1, CINC-2α/β and LIX and upregulated tissue inhibitor of matrix metalloproteinase (TIMP)-1. Interestingly, lung macrophage invasion was increased in both, Perfadex and prednisolone treated grafts, as measured by MMP-12 or RM4. Markers of anti-inflammatory macrophage transdifferentiation like MRC-1, IL-13, IL-4 and CD163, significantly correlated with prednisolone treatment. These observations lead to the conclusion that prednisolone as an additive to the perfusion solution protects from hypoxia triggered danger signals already in the phase of ischemia and thus reduces graft edema in the phase of reperfusion. Additionally, prednisolone preconditioning might also lead to macrophage polarization as a beneficial long-term effect. 相似文献
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Elbir H Gimenez G Robert C Bergström S Cutler S Raoult D Drancourt M 《Journal of bacteriology》2012,194(14):3723-3724
We announce the draft genome sequence of Borrelia crocidurae (strain Achema). The 1,557,560-bp genome (27% GC content) comprises one 919,477-bp linear chromosome and 638,083-bp plasmids that together carry 1,472 open reading frames, 32 tRNAs, and three complete rRNAs, with almost complete colinearity between B. crocidurae and Borrelia duttonii chromosomes. 相似文献
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The herbicide-inducible, soluble cytochrome P450s CYP105A1 and CYP105B1 and their adjacent ferredoxins, Fd1 and Fd2, of Streptomyces griseolus were expressed in Escherichia coli to high levels. Conditions for high-level expression of active enzyme able to catalyze hydroxylation have been developed. Analysis of the expression levels of the P450 proteins in several different E. coli expression hosts identified E. coli BL21 Star(DE3)pLysS as the optimal host cell to express CYP105B1 as judged by CO difference spectra. Examination of the codons used in the CYP1051A1 sequence indicated that it contains a number of codons corresponding to rare E. coli tRNA species. The level of its expression was improved in the modified forms of E. coli BL21(DE3), which contain extra copies of rare codon E. coli tRNA genes. The activity of correctly folded cytochrome P450s was further enhanced by cloning a ferredoxin reductase from Streptomyces coelicolor downstream of CYP105A1 and CYP105B1 and their adjacent ferredoxins. Expression of CYP105A1 and CYP105B1 was also achieved in Streptomyces lividans 1326 by cloning the P450 genes and their ferredoxins into the expression vector pBW160. S. lividans 1326 cells containing CYP105A1 or CYP105B1 were able efficiently to dealkylate 7-ethoxycoumarin. 相似文献
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DNA polymerase beta 总被引:6,自引:0,他引:6
Idriss HT Al-Assar O Wilson SH 《The international journal of biochemistry & cell biology》2002,34(4):321-324
Mammalian DNA polymerase beta(beta-pol) is a single polypeptide chain enzyme of 39kDa. beta-pol has enzymatic activities appropriate for roles in base excision repair and other DNA metabolism events involving gap-filling DNA synthesis. Many crystal structures of beta-pol complexed with dNTP and DNA substrates have been solved, and mouse fibroblast cell lines deleted in the beta-pol gene have been examined. These approaches have enhanced our understanding of structural and functional aspects of beta-pol's role in protecting genomic DNA. 相似文献
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Khalid F. AlHabib Kadhim Sulaiman Jassim Al Suwaidi Wael Almahmeed Alawi A. Alsheikh-Ali Haitham Amin Mohammed Al Jarallah Hussam F. Alfaleh Prashanth Panduranga Ahmad Hersi Tarek Kashour Zohair Al Aseri Anhar Ullah Hani B. Altaradi Kazi Nur Asfina Robert C. Welsh Salim Yusuf 《PloS one》2016,11(1)