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81.
Preventing and eradicating biofilms remains a challenge in clinical and industrial settings. Recently, the present authors demonstrated that silver oxynitrate (Ag7NO11) prevented and eradicated single-species planktonic and biofilm populations of numerous microbes at lower concentrations than other silver (Ag) compounds. Here, the antimicrobial and anti-biofilm efficacy of Ag7NO11 is elaborated by testing its in vitro activity against combinations of dual-species, planktonic and biofilm populations of Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa. As further evidence emerges that multispecies bacterial communities are more common in the environment than their single-species counterparts, this study reinforces the diverse applicability of the minimal biofilm eradication concentration (MBEC?) assay for testing antimicrobial compounds against biofilms. Furthermore, this study demonstrated that Ag7NO11 had enhanced antimicrobial and anti-biofilm activity compared to copper sulfate (CuSO4) and silver nitrate (AgNO3) against the tested bacterial species. 相似文献
82.
Nghiem Peter P. Bello Luca Balog-Alvarez Cindy López Sara Mata Bettis Amanda Barnett Heather Hernandez Briana Schatzberg Scott J. Piercy Richard J. Kornegay Joe N. 《Mammalian genome》2017,28(3-4):106-113
Mammalian Genome - Dystrophin is a key cytoskeletal protein coded by the Duchenne muscular dystrophy (DMD) gene located on the X-chromosome. Truncating mutations in the DMD gene cause loss of... 相似文献
83.
Cell division in Escherichia coli is mediated by a large protein complex called the divisome. Most of the divisome proteins have been identified, but how they assemble onto the Z ring scaffold to form the divisome and work together to synthesize the septum is not well understood. In this review, we summarize the latest findings on divisome assembly and activation as well as provide our perspective on how these two processes might be regulated. 相似文献
84.
Analysis of individual cells identifies cell‐to‐cell variability following induction of cellular senescence 下载免费PDF全文
Christopher D. Wiley James M. Flynn Christapher Morrissey Ronald Lebofsky Joe Shuga Xiao Dong Marc A. Unger Jan Vijg Simon Melov Judith Campisi 《Aging cell》2017,16(5):1043-1050
Senescent cells play important roles in both physiological and pathological processes, including cancer and aging. In all cases, however, senescent cells comprise only a small fraction of tissues. Senescent phenotypes have been studied largely in relatively homogeneous populations of cultured cells. In vivo, senescent cells are generally identified by a small number of markers, but whether and how these markers vary among individual cells is unknown. We therefore utilized a combination of single‐cell isolation and a nanofluidic PCR platform to determine the contributions of individual cells to the overall gene expression profile of senescent human fibroblast populations. Individual senescent cells were surprisingly heterogeneous in their gene expression signatures. This cell‐to‐cell variability resulted in a loss of correlation among the expression of several senescence‐associated genes. Many genes encoding senescence‐associated secretory phenotype (SASP) factors, a major contributor to the effects of senescent cells in vivo, showed marked variability with a subset of highly induced genes accounting for the increases observed at the population level. Inflammatory genes in clustered genomic loci showed a greater correlation with senescence compared to nonclustered loci, suggesting that these genes are coregulated by genomic location. Together, these data offer new insights into how genes are regulated in senescent cells and suggest that single markers are inadequate to identify senescent cells in vivo. 相似文献
85.
86.
Joe G. G. Vethanayagam Edie H. Green Richard C. Rose Ann M. Bode 《Free radical biology & medicine》1999,26(11-12):1591-1598
An efficient regeneration of vitamin C (ascorbate) from its oxidized byproduct, dehydroascorbate (DHAA), is necessary to maintain sufficient tissue levels of the reduced form of the vitamin. Additionally, the recycling may be more significant in mammals, such as guinea pigs and humans, who have lost the ability to synthesize ascorbate de novo, than it is in most other mammals who have retained the ability to synthesize the vitamin from glucose. Both a chemical and an enzymatic reduction of DHAA to ascorbate have been proposed. Several reports have appeared in which proteins, including thioltransferase, protein disulfide isomerase, and 3-alpha-hydroxysteroid dehydrogenase, characterized for other activities have been identified as having DHAA reductase activity in vitro. Whether these previously characterized proteins catalyze the reduction of DHAA in vivo is unclear. In the present study, a 66 kD protein was purified strictly on the basis of its DHAA-reductase activity and was identified as rat serum albumin. The protein was further characterized and results support the suggestion that serum albumin acts as an antioxidant and exerts a significant glutathione-dependent DHAA-reductase activity that may be important in the physiologic recycling of ascorbic acid. 相似文献
87.
Joe B. Gilroy Michael J. Ferguson Robert McDonald Robin G. Hicks 《Inorganica chimica acta》2008,361(12-13):3388-3393
3-Nitroformazans react with bis(1,1,1,5,5,5-hexafluroacetylacetonato)palladium to afford monometallic complexes. The complexes were characterized via X-ray crystallography, cyclic voltammetry, and electronic spectroscopy. The nature of the aryl substituents on the formazan ligands had a profound effect on the structure and spectroscopy of the complexes, with o-substituted aromatic rings twisted with respect to the ligand, while the p-tolyl substituted derivative adopted a planar structure. The complexes undergo irreversible reductions near ?1 V versus Fc/Fc+. 相似文献
88.
Manoharan Melvin Joe Mohinutheen Chanbhasa Allen John Henry 《Archives Of Phytopathology And Plant Protection》2017,50(9-10):491-503
In the present study the antibacterial activity of spent green tea (SGT) was evaluated against Pectobacterium spp. causing soft rot incidence. Gas chromatography and mass spectroscopy (GC-MS) analysis reveal the presence of caffeine in the SGT extracts. Time kill assay revealed that SGT was able to kill Pectobacterium spp. at 18 h at 10 × MIC and at 24 h at 1 × MIC concentration. SGT led to the significant decrease in pectin lyase (PL), polygalcturonase (PG) and pectin methyl esterase activity in carrots challenge inoculated with Pectobacterium spp. SGT treated carrots recorded low degree of maceration, and relative electrolyte leakage (REL) values and also maintained high β carotene content, phenolic content and total antioxidant percentage. Based on the results of this study it could be concluded that SGT was able to offer protection to carrot against soft rot causing Pectobacterium spp. under post-harvest storage conditions. 相似文献
89.
Reviewing the Technical Designs for Experiments with Ultraviolet-B Radiation and Impact on Photosynthesis, DNA and Secondary Metabolism 总被引:1,自引:0,他引:1
The ultraviolet-B (UV-B) portion of sunlight has received much attention in the last three decades, because radiation from this spectral region increases due to the stratospheric ozone depletion, which results from increases of chlorofluorocarbons in the atmosphere. Plant responses to UV-B exposure vary greatly and the interpretation of and comparison between studies is hindered, mainly by the contrasting experimental conditions used and interactive factors such as low light levels and possible artifacts due to the artificial experimental conditions. It seems likely that increases in solar UV-B radiation of the magnitude anticipated under current stratospheric ozone projections will not significantly inhibit photosynthesis and cause DNA damage in plants. This is in part due to the well-evolved protection mechanisms present in most plant species. One of the significant plant responses to UV-B is changes in foliar secondary chemistry, which could be translated into significant effects at higher trophic levels through plant-herbivore interactions and decomposition. Enhanced UV-B radiation due to stratospheric ozone depletion could also cause morphological changes that would affect competitive interactions, especially if contrasting UV-B sensitivity exists among the competitors. 相似文献
90.
Christian S. A. da SILVA TORRES Robert W. MATTHEWS John R. RUBERSON W. Joe LEWIS 《Entomological Science》2005,8(4):355-362
Parasitoids are expected to have the ability to find, recognize, and perhaps to discern potential hosts that can best support the development of their progeny. Melittobia Westwood (Hymenoptera: Eulophidae) are gregarious ectoparasitoids, which primarily attack mud daubers (Hymenoptera: Sphecidae). How Melittobia females locate their host is not well known, but the process may involve host‐related chemical signals. In this study, we investigated the roles of host chemical cues and natal rearing effect in host recognition by Mel. digitata Dahms. In an olfactometer that contained prepupae of Trypoxylon politum Say (Hymenoptera: Sphecidae), Megachile rotundata (Fabricius) (Hymenoptera: Megachilidae), puparia of Neobellieria bullata (Parker) (Diptera: Sarcophagidae), empty or intact host cocoons, or nest mud, Mel. digitata females spent significantly more time in air fields that contained T. politum (prepupae + cocoon) and Meg. rotundata (prepupae + cocoon) than in N. bullata and control fields. Nest mud and natal host had no attraction for parasitoid host choice. Most first and last choices of Mel. digitata females in the olfactometer were not consistent, suggesting an initial random dispersion, although they responded positively towards hosts in cocoons. 相似文献