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Marine bacteria from aquaculture areas with industrial use of quinolones have the potential to pass quinolone resistance genes to animal and human pathogens. The VPA0095 gene, related to the quinolone resistance determinant qnrA, from clinical isolates of epidemic Vibrio parahaemolyticus conferred reduced susceptibility to quinolone after cloning into Escherichia coli K-12 either when acting alone or synergistically with DNA gyrase mutations. In addition, a plasmid-mediated quinolone resistance gene from marine bacteria, aac(6′)-Ib-cr, was identical to aac(6′)-Ib-cr from urinary tract isolates of E. coli, suggesting a recent flow of this gene between these bacteria isolated from different environments. aac(6′)-Ib-cr from E. coli also conferred reduced susceptibility to quinolone and kanamycin when cloned into E. coli K-12. 相似文献
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Juha J. Saarinen Alison G. Boyer James H. Brown Daniel P. Costa S. K. Morgan Ernest Alistair R. Evans Mikael Fortelius John L. Gittleman Marcus J. Hamilton Larisa E. Harding Kari Lintulaakso S. Kathleen Lyons Jordan G. Okie Richard M. Sibly Patrick R. Stephens Jessica Theodor Mark D. Uhen Felisa A. Smith 《Proceedings. Biological sciences / The Royal Society》2014,281(1784)
There is accumulating evidence that macroevolutionary patterns of mammal evolution during the Cenozoic follow similar trajectories on different continents. This would suggest that such patterns are strongly determined by global abiotic factors, such as climate, or by basic eco-evolutionary processes such as filling of niches by specialization. The similarity of pattern would be expected to extend to the history of individual clades. Here, we investigate the temporal distribution of maximum size observed within individual orders globally and on separate continents. While the maximum size of individual orders of large land mammals show differences and comprise several families, the times at which orders reach their maximum size over time show strong congruence, peaking in the Middle Eocene, the Oligocene and the Plio-Pleistocene. The Eocene peak occurs when global temperature and land mammal diversity are high and is best explained as a result of niche expansion rather than abiotic forcing. Since the Eocene, there is a significant correlation between maximum size frequency and global temperature proxy. The Oligocene peak is not statistically significant and may in part be due to sampling issues. The peak in the Plio-Pleistocene occurs when global temperature and land mammal diversity are low, it is statistically the most robust one and it is best explained by global cooling. We conclude that the macroevolutionary patterns observed are a result of the interplay between eco-evolutionary processes and abiotic forcing. 相似文献
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N. I. Lisyanyi V. A. Rudenko O. V. Markova I. A. Gnedkova T. A. Lisyanaya L. D. Lyubich O. B. Gorobets L. N. Bel’skaya 《Human physiology》2000,26(1):79-85
The data on the immune and autoimmune disturbances in certain brain diseases such as brain tumors, remote consequences of
craniocerebral injury, epilepsy, and postradiation encephalopathy are presented. Various changes in cellular and humoral immunity
are established. The development of autoimmune reactions to brain antigens is analyzed in comparison with the level of immune
complexes. The results are discussed in the context of disruption of the immune system neurohumoral regulation and development
of neurogenic immunity deficiency and its different types. The specific function of the immunocompetent cells, which penetrated
beyond the blood-brain barrier under physiological and immunopathological conditions of the CNS, and the apoptotic death of
the lymphocytes were suggested. Attention was drawn to the importance of the investigation of systemic, as well as regional,
immune processes outside the blood-brain barrier. 相似文献