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排序方式: 共有123条查询结果,搜索用时 31 毫秒
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S. Troupel G. Le Moel A. Bouten H. Fessi Z. Boukhalfa G. Stamatakis V. Lecon JP. Mery J. Agneray C. Jacobs 《Amino acids》1992,2(1-2):127-132
Summary A well preserved nutritional status is beneficial in chronically uremic patients for slowing the pace of deterioration of renal function, and delaying the need for dialysis therapy. The purpose of this study was to assess the nutritional profile of 10 patients in a steady state of advanced CRF, and of 15 patients with terminal renal failure immediately prior to their first hemodialysis session (J0), and 7, 14, 45, 60, days post start of dialysis. Patients were 18 to 65 years old with total plasma proteins 60g/1. Plasma concentrations of amino acids, nutrition proteins, apolipoproteins A1, and B were evaluated. Non inflammatory reaction was evaluated by determination of alpha-1-acid glycoprotein, and C reactive protein. The data (mean ± 1 SD) were compared with mean values of 15 healthy individuals. 相似文献
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Ribotyping of Erwinia chrysanthemi Strains in Relation to Their Pathogenic and Geographic Distribution 总被引:1,自引:0,他引:1
Nassar A Bertheau Y Dervin C Narcy JP Lemattre M 《Applied and environmental microbiology》1994,60(10):3781-3789
16S and 23S rRNAs from Escherichia coli were used to study the relationship among a representative collection of strains of Erwinia chrysanthemi differing in their original host and geographical origin. Phenetic analysis of restriction fragment length polymorphisms allowed the distribution of the studied strains into seven clusters. These clusters were similar to those obtained by cladistic methods and appeared to correlate well with the established pathovars and biovars but to a lesser extent with geographical distribution. Except for two groups of strains defined as tropical and temperate isolates (clusters 3 and 4, respectively), our clustering correlated well with botanical classifications of host plants. However, the rRNA groupings were shown to be more discriminative than biovar analysis. To assess the relationship between rRNA clusters and pathogenicity, 12 representative strains from different clusters were tested for pathogenicity on different plants. The two typical symptoms, maceration and wilting, were observed for these strains. The occurrence of the tobacco hypersensitivity reaction for a subset of these strains is discussed in light of recent results concerning the presence of an hrp gene. Considering symptom expression only, rather than the capacity for plant infection, strains from the same cluster were shown to induce similar symptoms in test plants. Thus, since host specificity is still quite controversial, rRNA patterns may constitute a useful tool in taxonomic and epidemiological studies of Erwinia chrysanthemi species. 相似文献
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Juhas M Power PM Harding RM Ferguson DJ Dimopoulou ID Elamin AR Mohd-Zain Z Hood DW Adegbola R Erwin A Smith A Munson RS Harrison A Mansfield L Bentley S Crook DW 《Genome biology》2007,8(11):R237-14
Background
A major part of horizontal gene transfer that contributes to the diversification and adaptation of bacteria is facilitated by genomic islands. The evolution of these islands is poorly understood. Some progress was made with the identification of a set of phylogenetically related genomic islands among the Proteobacteria, recognized from the investigation of the evolutionary origins of a Haemophilus influenzae antibiotic resistance island, namely ICEHin1056. More clarity comes from this comparative analysis of seven complete sequences of the ICEHin1056 genomic island subfamily.Results
These genomic islands have core and accessory genes in approximately equal proportion, with none demonstrating recent acquisition from other islands. The number of variable sites within core genes is similar to that found in the host bacteria. Furthermore, the GC content of the core genes is similar to that of the host bacteria (38% to 40%). Most of the core gene content is formed by the syntenic type IV secretion system dependent conjugative module and replicative module. GC content and lack of variable sites indicate that the antibiotic resistance genes were acquired relatively recently. An analysis of conjugation efficiency and antibiotic susceptibility demonstrates that phenotypic expression of genomic island-borne genes differs between different hosts.Conclusion
Genomic islands of the ICEHin1056 subfamily have a longstanding relationship with H. influenzae and H. parainfluenzae and are co-evolving as semi-autonomous genomes within the 'supragenomes' of their host species. They have promoted bacterial diversity and adaptation through becoming efficient vectors of antibiotic resistance by the recent acquisition of antibiotic resistance transposons. 相似文献98.
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Luis Clepf Passos Marianne Araújo Soares Mariana Abreu Costa JP Michaud Brenda Carolina Freire Geraldo Andrade Carvalho 《Biocontrol Science and Technology》2017,27(9):1082-1095
In order to aid the integration of biological and chemical controls for the tomato leaf miner, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), this study evaluated the relative toxicity of five insecticides to the leaf miner predator Macrolophus basicornis (Stal) (Hemiptera: Miridae). The insecticides evaluated were teflubenzuron, abamectin, chlorantraniliprole, chlorfenapyr, and cartap hydrochloride, all of which are recommended for control of T. absoluta in Brazil. Nymphs and adults of M. basicornis were exposed to tomato leaves treated with the insecticides, under laboratory and greenhouse conditions. The overall mortality caused by the products in both situations was recorded, and the survival of congeneric groups was analysed using the Weibull model. The persistence of the insecticides was also evaluated and they were categorised into toxicity classes proposed by the International Organisation for Biological Control (IOBC) based on predator mortality and persistence. Abamectin and chlorfenapyr were toxic to M. basicornis nymphs and adults in all bioassays. Cartap hydrochloride was slightly harmful to adults in laboratory assays, but harmful to nymphs, and moderately harmful under greenhouse conditions. Chlorantraniliprole and teflubenzuron were harmless in most assays, except when nymphs were exposed in the laboratory, where they were moderately and slightly harmful, respectively. Chlorantraniliprole and teflubenzuron should be preferred insecticides for use in tomato leaf miner IPM programmes that aim to conserve M. basicornis populations. 相似文献
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We have studied the functional effects of extracellular Cd(2+) on human ether-a-go-go-related gene (HERG) encoded K(+) channels. Low concentrations (10-200 &mgr;M) of extracellular Cd(2+) increased outward currents through HERG channels; 200 &mgr;M Cd(2+) more than doubled HERG currents and altered current kinetics. Cd(2+) concentrations up to 200 &mgr;M did not change the voltage dependence of channel activation, but shifted the voltage dependence of inactivation to more depolarized membrane potentials. Cd(2+) concentrations >/=500 &mgr;M shifted the voltage dependence of channel activation to more positive potentials. These results are consistent with a somewhat specific ability of Cd(2+) to destabilize the inactivated state. We tested the hypothesis that channel inactivation is essential for Cd(2+)-induced increases in HERG K(+) currents, using a double point mutation (G628C/S631C) that diminishes HERG inactivation (Smith, P. L., T. Baukrowitz, and G. Yellen. 1996. Nature (Lond.). 379:833-836). This inactivation-removed mutant is insensitive to low concentrations of Cd(2+). Thus, Cd(2+) had two distinct effects on HERG K(+) channels. Low concentrations of Cd(2+) caused relatively selective effects on inactivation, resulting in a reduction of the apparent rectification of the channel and thereby increasing HERG K(+) currents. Higher Cd(2+) concentrations affected activation gating as well, possibly by a surface charge screening mechanism or by association with a lower affinity site. 相似文献