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Morley EK Williams RH Hughes JM Thomasson D Terry RS Duncanson P Smith JE Hide G 《Parasitology》2008,135(2):169-173
A study carried out on a sheep farm examined whether Toxoplasma gondii foetal infection and associated abortion occur in successive lambings. We identified 29 ewes that gave birth to lambs on at least 2 successive years over our study period, 2000-2003. Tissue samples from the progeny of these ewes were analysed by PCR to determine infection status with T. gondii. T. gondii-infected lambs were born in 31% of successive pregnancies. T. gondii-positive lambs were aborted in successive pregnancies in 21% of lambings during study period, 2000-2003. The frequency of successive abortions within this flock over the period 1992-2003 was 18%. If a lamb was congenitally infected there was a high risk (69%) that the successive lamb from that ewe would also be congenitally infected. Similarly, if a lamb was aborted there was a high risk (55%) of abortion in the next lamb produced. These data suggest that life-long immunity to T. gondii infections may not always be acquired following an initial infection and raises the question as to whether the mechanisms of T. gondii transmission prior to and during ovine pregnancies are fully understood. 相似文献
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Katy L. Blake Alex J. O'Neill Dominique Mengin-Lecreulx Peter J. F. Henderson Julieanne M. Bostock Colin J. Dunsmore Katie J. Simmons Colin W. G. Fishwick Jennifer A. Leeds Ian Chopra 《Molecular microbiology》2009,72(2):335-343
Staphylococcus aureus and a number of other Gram-positive organisms harbour two genes ( murA and murZ ) encoding UDP- N -acetylglucosamine enolpyruvyl transferase activity for catalysing the first committed step of peptidoglycan biosynthesis. We independently inactivated murA and murZ in S. aureus and established that either can sustain viability. Purification and characterization of the MurA and MurZ enzymes indicated that they are biochemically similar in vitro , consistent with similar overall structures predicted for the isozymes by molecular modelling. Nevertheless, MurA appears to be the primary enzyme utilized in the staphylococcal cell. Accordingly, murA expression was approximately five times greater than murZ expression during exponential growth, and the peptidoglycan content of S. aureus was reduced by approximately 25% following inactivation of murA , but remained almost unchanged following inactivation of murZ . Despite low level expression during normal growth, murZ expression was strongly induced (up to sixfold) following exposure to inhibitors of peptidoglycan biosynthesis, which was not observed for murA . Strains generated in this study were validated as potential tools for identifying novel anti-staphylococcal agents targeting peptidoglycan biosynthesis using known inhibitors of the pathway. 相似文献
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Andrew D. Morley Peter W. Kenny Brenda Burton Robert A. Heald Philip A. MacFaul Julia Mullett Ken Page Soraya S. Porres Lyn Rosenbrier Ribeiro Phil Smith Stuart Ward Tina J. Wilkinson 《Bioorganic & medicinal chemistry letters》2009,19(6):1658-1661
A series of pyrimidine nitrile inhibitors of Cathepsin K with reduced glutathione reactivity has been identified and Molecular Core Matching (MoCoM) has been used to quantify the effect of an amino substituent at C5. 相似文献
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Nabil Asaad Paul A. Bethel Michelle D. Coulson Jack E. Dawson Susannah J. Ford Stefan Gerhardt Matthew Grist Gordon A. Hamlin Michael J. James Emma V. Jones Galith I. Karoutchi Peter W. Kenny Andrew D. Morley Keith Oldham Neil Rankine David Ryan Stuart L. Wells Linda Wood Martin Augustin Stephan Krapp Stefan Steinbacher 《Bioorganic & medicinal chemistry letters》2009,19(15):4280-4283
A series of potent Cathepsin L inhibitors with good selectivity with respect to other cysteine Cathepsins is described and SAR is discussed with reference to the crystal structure of a protein-ligand complex. 相似文献
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