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51.
Gudrun Lisa Bovenkamp Ulrike Zanzen Katla Sai Krishna Josef Hormes Alexander Prange 《Applied and environmental microbiology》2013,79(20):6385-6390
Silver ions are widely used as antibacterial agents, but the basic molecular mechanism of this effect is still poorly understood. X-ray absorption near-edge structure (XANES) spectroscopy at the Ag LIII, S K, and P K edges reveals the chemical forms of silver in Staphylococcus aureus and Escherichia coli (Ag+ treated). The Ag LIII-edge XANES spectra of the bacteria are all slightly different and very different from the spectra of silver ions (silver nitrate and silver acetate), which confirms that a reaction occurs. Death or inactivation of bacteria was observed by plate counting and light microscopy. Silver bonding to sulfhydryl groups (Ag-S) in cysteine and Ag-N or Ag-O bonding in histidine, alanine, and dl-aspartic acid was detected by using synthesized silver-amino acids. Significantly lower silver-cysteine content, coupled with higher silver-histidine content, in Gram-positive S. aureus and Listeria monocytogenes cells indicates that the peptidoglycan multilayer could be buffering the biocidal effect of silver on Gram-positive bacteria, at least in part. Bonding of silver to phosphate groups was not detected. Interaction with DNA or proteins can occur through Ag-N bonding. The formation of silver-cysteine can be confirmed for both bacterial cell types, which supports the hypothesis that enzyme-catalyzed reactions and the electron transport chain within the cell are disrupted. 相似文献
52.
Lucia Vergauwen Dries Knapen An Hagenaars Gudrun De Boeck Ronny Blust 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》2013,183(1):109-121
The zebrafish has become a valuable vertebrate model organism in a wide range of scientific disciplines, but current information concerning the physiological temperature response of adult zebrafish is rather scarce. In this study, zebrafish were experimentally acclimated for 28 days to 18, 26 or 34 °C and a suite of non-invasive and invasive methods was applied to determine the thermal dependence of zebrafish physiological condition. With decreasing temperature, the metabolic rate of zebrafish decreased, as shown by the decreasing oxygen uptake and ammonia excretion rates, limiting the critical swimming speed, probably due to a decreased muscle fibre power output. In response to exercise, fuel stores were mobilized to the liver as shown by the increased hepatosomatic index, liver total absolute energetic value and liver carbohydrate concentration but due to the low metabolic rate they could not be adequately addressed to power swimming activity at 18 °C. Conversely, the increased metabolic performance at high temperature came with an increased metabolic cost resulting in decreased energy status reflected particularly well by the non-invasive condition factor and invasive measures of carcass protein concentration, carcass total absolute energetic value and liver carbohydrate concentration. We showed that the combined measurement of the relative condition factor and critical swimming speed is a powerful non-invasive tool for long-term follow-up studies. Invasive methods were redundant for measuring general energy status but they provided detailed information concerning metabolic reorganization. With this study we proved that the usefulness of the zebrafish as a model organism can easily be expanded to include physiological studies and we provided a reference dataset for the selection of measures of physiological responses for future studies using the zebrafish. 相似文献
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54.
Pathophysiology of white-nose syndrome in bats: a mechanistic model linking wing damage to mortality
Lisa Warnecke James M. Turner Trent K. Bollinger Vikram Misra Paul M. Cryan David S. Blehert Gudrun Wibbelt Craig K. R. Willis 《Biology letters》2013,9(4)
White-nose syndrome is devastating North American bat populations but we lack basic information on disease mechanisms. Altered blood physiology owing to epidermal invasion by the fungal pathogen Geomyces destructans (Gd) has been hypothesized as a cause of disrupted torpor patterns of affected hibernating bats, leading to mortality. Here, we present data on blood electrolyte concentration, haematology and acid–base balance of hibernating little brown bats, Myotis lucifugus, following experimental inoculation with Gd. Compared with controls, infected bats showed electrolyte depletion (i.e. lower plasma sodium), changes in haematology (i.e. increased haematocrit and decreased glucose) and disrupted acid–base balance (i.e. lower CO2 partial pressure and bicarbonate). These findings indicate hypotonic dehydration, hypovolaemia and metabolic acidosis. We propose a mechanistic model linking tissue damage to altered homeostasis and morbidity/mortality. 相似文献
55.
Joanna Szkandera Gudrun Absenger Bernadette Liegl-Atzwanger Martin Pichler Michael Stotz Stefan Gerger Maximilian Zacherl Wilfried Renner Miao Haijun Andreas Leithner Armin Gerger 《Cancer epidemiology》2013,37(6):1003-1009
BackgroundDNA repair mechanisms play a major role in cancer risk and progression. Germline variants in DNA repair genes may result in altered gene function and/or activity, thereby causing inter-individual differences in a patient's tumor recurrence capacity. In genes of the DNA repair pathway the gene variants RAD51 rs1801320 G > C, XRCC2 rs3218536 G > A and XPD rs13181 A > C have been previously related to genetic predisposition and prognosis of various cancer entities. In this study we investigated the association between these polymorphisms and time to recurrence (TTR) and overall survival (OS) in soft-tissue sarcoma (STS) patients after curative surgery.MethodsTwo hundred sixty STS patients were included in this retrospective study. Germline DNA was genotyped by 5′-exonuclease (TaqMan) technology. Kaplan Meier curves and multivariate Cox proportional models were calculated for TTR and OS.ResultsA statistically significant association was observed between tumor grade and adjuvant radiotherapy and TTR and between tumor grade and OS. No association was found between RAD51 rs1801320 G > C, XRCC2 rs3218536 G > A and XPD rs13181 A > C and TTR and OS in univariate and multivariate analysis.ConclusionOur results underline a prognostic effect of tumor grade and adjuvant radiotherapy in STS patients but indicate no association between RAD51 rs1801320 G > C, XRCC2 rs3218536 G > A and XPD rs13181 A > C and clinical outcome in STS patients after curative surgery. 相似文献
56.
Epigenetic dysregulation in the developing Down syndrome cortex 总被引:1,自引:0,他引:1
Nady El Hajj Marcus Dittrich Julia Böck Theo F. J. Kraus Indrajit Nanda Tobias Müller 《Epigenetics》2016,11(8):563-578
57.
Elizabeth P. St. John Birgitte B. Simen Gregory S. Turenchalk Michael S. Braverman Isabella Abbate Jeroen Aerssens Olivier Bouchez Christian Gabriel Jacques Izopet Karolin Meixenberger Francesca Di Giallonardo Ralph Schlapbach Roger Paredes James Sakwa Gudrun G. Schmitz-Agheguian Alexander Thielen Martin Victor Karin J. Metzner Martin P. D?umer HIV- Alpha Study Group 《PloS one》2016,11(1)
58.
Gerald Sendlhofer David Benjamin Lumenta Karina Leitgeb Brigitte Kober Lydia Jantscher Monika Schanbacher Andrea Berghold Gudrun Pregartner Gernot Brunner Christa Tax Lars Peter Kamolz 《PloS one》2016,11(2)
Background
“The Surgical Safety Checklist (SSC) is important, but we don’t use it adequately” is a well-suited statement that reflects the SSC''s application in hospitals. Our aim was to follow up on our initial study on compliance (2014) by analysing differences between individual perception and compliance with the SSC.Methods
We conducted a follow-up online survey to assess healthcare professionals’ individual perception of, as well as satisfaction and compliance with the SSC three years following its thorough implementation.Results
171 (19.5%) of 875 operating team members completed the online survey. 99.4% confirmed using the SSC. Self-estimated subjective knowledge about the intention of the checklist was high, whereas objective knowledge was moderate, but improved as compared to 2014. According to an independent audit the SSC was used in 93.1% of all operations and among the SSCs used the completion rate was 57.2%. The use of the SSC was rated as rather easy [median (IQR): 7 (6–7)], familiar [7 (6–7)], generally important [7 (7–7)], and good for patients [7 (6–7)] as well as for employees [7 (7–7)]. Only comfort of use was rated lower [6 (5–7)].Conclusion
There is a gap between individual perception and actual application of the SSC. Despite healthcare professionals confirming the importance of the SSC, compliance was moderate. The introduction of SSCs in the health care sector remains a constant challenge and requires continuous re-evaluation as well as a sensible integration into existing workflows in hospitals. 相似文献59.
60.
Alibrahim Ammar Al-Gharabally Dunia Mahmoud Huda Dittrich Maria 《Extremophiles : life under extreme conditions》2019,23(6):765-781
Extremophiles - Microbes can be found in hypersaline environments forming diverse populations with complex ecological interactions. Microbes in such environments were found to be involved in the... 相似文献