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1.
Igor Loncaric Gabrielle L. Stalder Kemal Mehinagic Renate Rosengarten Franz Hoelzl Felix Knauer Chris Walzer 《PloS one》2013,8(12)
In order to test whether rooks (Corvus frugilegus) represent good indicators for the potential circulation of antibiotics in their native habitat, two populations with different migratory behavior were tested for the presence of beta-lactamase producing Enterobacteriaceae and methicillin-resistant Staphylococcus aureus (MRSA). In all, 54 and 102 samples of fresh feces of a migratory and a resident population were investigated. A total of 24 and 3 cefotaxime-resistant enterobacterial isolates were obtained from the migratory and resident population, respectively. In these isolates CTX-M-1 (n = 15), CTX-M-3 (n = 3), and CTX-M-15 (n = 3) genes were detected. TEM-1 and OXA-1 were associated with CTX-M in 3 and 2 isolates, respectively. In two E. coli isolates CMY-2 could be detected, where from one isolate displayed an overexpression of chromosomal AmpC as well. Among E. coli isolates the most common phylogenetic group was A (n = 11) and ST1683 (n = 5). In one E. coli of B2-ST131 the rfbO25b locus was detected. Three Enterobacter isolates were stably derepressed AmpC-producers. In five samples of the migratory population, PVL positive MRSA could be isolated. Two isolates were typed SCCmec IVa, spa type t127, and ST1. Three isolates carried a SCCmec type IVc, with spa type t852 and ST22. The highly significant difference of the occurrence of antibiotic resistance between the migratory population from eastern Europe compared to resident population in our study indicates that rooks may be good indicator species for the evaluation of environmental contamination with antibiotic resistant bacteria, especially due to their ecology, foraging behavior and differing migratory behavior. 相似文献
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Nimra Khan Dylan Pelletier Thomas S. McAlear Nathalie Croteau Simon Veyron Andrew N. Bayne Corbin Black Muneyoshi Ichikawa Ahmad Abdelzaher Zaki Khalifa Sami Chaaban Igor Kurinov Gary Brouhard Susanne Bechstedt Khanh Huy Bui Jean-François Trempe 《Structure (London, England : 1993)》2021,29(6):572-586.e6
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J R Lakowicz J Ku?ba W Wiczk I Gryczynski H Szmacinski M L Johnson 《Biophysical chemistry》1991,39(1):79-84
We report the first resolution of both the conformational distribution and end-to-end diffusion coefficient of a flexible molecule. This molecular information was recovered using only the donor intensity decay in a single solvent at a single viscosity, as observed by the technique of frequency-domain fluorometry. This technique can be extended to measurements of structural fluctuations of biological macromolecules. 相似文献
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Our studies aimed at determining a loss of active heparin from the peritoneal cavity after its intraperitoneal administration (250 JU/l of dialysis fluid) in 16 patients treated because of the end-stage renal failure with intermittent peritoneal dialysis and at comparing heparin influx clearance with that of glucose. It has been shown that heparin used in this dose loses 60-70% of its activity after 20-minute equilibration of dialysis fluid in the peritoneal cavity. Heparin influx clearance is higher than that of glucose but it depends on utilization of heparin in peritoneal cavity rather than on its penetration to the blood circulation. 相似文献
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Katharine Y. Ku Fred R. Butcher 《Biochimica et Biophysica Acta (BBA)/General Subjects》1980,631(1):70-78
Calmodulin coupled to Sepharose has provided a rapid and sensitive means of isolating a cyclic nucleotide phosphodiesterase activity which is stimulated by the calmodulin-Ca2+ complex, from rat parotid gland. Initial experiments established that phosphodiesterase activity sensitive to calmodulin and Ca2+ could not be demonstrated in crude extracts of rat parotid gland or after partial purification of rat parotid phosphodiesterase over DEAE-cellulose. However, it was possible to readily demonstrate the presence of a cyclic nucleotide phosphodiesterase activity regulated by calmodulin if the extracts were first purified by batch ion-exchange chromatography over DEAE-cellulose followed by affinity chromatography with calmodulin coupled to Sepharose. The batch ion-exchange chromatography step removed the major portion of free parotid calmodulin which could compete with calmodulin-coupled Sepharose for the proteins regulated by calmodulin. Thus, by employing an initial chromatography step over DEAE-cellulose to separate phosphodiesterase activity from calmodulin, it was possible to increase the recovery of calmodulin-sensitive phosphodiesterase after affinity chromatography with calmodulin coupled to Sepharose. This approach should be useful for demonstrating the presence of and for purifying other parotid proteins regulated by calmodulin. 相似文献
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In vitro as well as in vivo evaluation of the reactivating efficacy of various oximes against nerve agent-inhibited acetylcholinesterase has been usually done with the help of animal experiments. Nevertheless, previously published data indicate that the reactivation potency of oximes may be different in human and animal species, which may hamper the extrapolation of animal data to human data. Therefore, to better evaluate the efficacy of various oximes (pralidoxime, obidoxime, HI-6, K033) to reactivate brain acetylcholinesterase inhibited by sarin by in vitro methods, human, rat and pig brain acetylcholinesterase were used to calculate kinetic parameters for the reactivation. Our results show differences among the species, depending on the type of oxime, and indicate that data from animal experiments needs to be carefully evaluated before extrapolation to humans. 相似文献