The Experts below are selected from a list of 157974 Experts worldwide ranked by ideXlab platform
Frank E Loffle - One of the best experts on this subject based on the ideXlab platform.
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fnr etra acts as a fine tuning regulator of Anaerobic Metabolism in shewanella oneidensis mr 1
BMC Microbiology, 2011Co-Authors: Jeffrey A Gralnick, Claribel Cruzgarcia, Aliso E Murray, Jorge L M Rodrigues, Lee A Mccue, Margare F Romine, Frank E LoffleAbstract:Background EtrA in Shewanella oneidensis MR-1, a model organism for study of adaptation to varied redox niches, shares 73.6% and 50.8% amino acid sequence identity with the oxygen-sensing regulators Fnr in E. coli and Anr in Pseudomonas aeruginosa, respectively; however, its regulatory role of Anaerobic Metabolism in Shewanella spp. is complex and not well understood.
Claribel Cruzgarcia - One of the best experts on this subject based on the ideXlab platform.
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fnr etra acts as a fine tuning regulator of Anaerobic Metabolism in shewanella oneidensis mr 1
BMC Microbiology, 2011Co-Authors: Jeffrey A Gralnick, Claribel Cruzgarcia, Aliso E Murray, Jorge L M Rodrigues, Lee A Mccue, Margare F Romine, Frank E LoffleAbstract:Background EtrA in Shewanella oneidensis MR-1, a model organism for study of adaptation to varied redox niches, shares 73.6% and 50.8% amino acid sequence identity with the oxygen-sensing regulators Fnr in E. coli and Anr in Pseudomonas aeruginosa, respectively; however, its regulatory role of Anaerobic Metabolism in Shewanella spp. is complex and not well understood.
Aliso E Murray - One of the best experts on this subject based on the ideXlab platform.
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fnr etra acts as a fine tuning regulator of Anaerobic Metabolism in shewanella oneidensis mr 1
BMC Microbiology, 2011Co-Authors: Jeffrey A Gralnick, Claribel Cruzgarcia, Aliso E Murray, Jorge L M Rodrigues, Lee A Mccue, Margare F Romine, Frank E LoffleAbstract:Background EtrA in Shewanella oneidensis MR-1, a model organism for study of adaptation to varied redox niches, shares 73.6% and 50.8% amino acid sequence identity with the oxygen-sensing regulators Fnr in E. coli and Anr in Pseudomonas aeruginosa, respectively; however, its regulatory role of Anaerobic Metabolism in Shewanella spp. is complex and not well understood.
Jeanlouis Teboul - One of the best experts on this subject based on the ideXlab platform.
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lactate and venoarterial carbon dioxide difference arterial venous oxygen difference ratio but not central venous oxygen saturation predict increase in oxygen consumption in fluid responders
Critical Care Medicine, 2013Co-Authors: Xavier Monnet, Nadia Anguel, Florence Julien, Nora Aithamou, Marie Lequoy, Clement Gosset, Mathieu Jozwiak, Romain Persichini, Christian Richard, Jeanlouis TeboulAbstract:Objectives:During circulatory failure, the ultimate goal of treatments that increase cardiac output is to reduce tissue hypoxia. This can only occur if oxygen consumption depends on oxygen delivery. We compared the ability of central venous oxygen saturation and markers of Anaerobic Metabolism to pr
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combination of venoarterial pco2 difference with arteriovenous o2 content difference to detect Anaerobic Metabolism in patients
Intensive Care Medicine, 2002Co-Authors: Armand Mekontsodessap, Vince Castelai, Nadia Anguel, Mabrouk Ahloul, Franck Schauvliege, C Richard, Jeanlouis TeboulAbstract:Objective: Under conditions of tissue hypoxia total CO2 production (VCO2) should be less reduced than O2 consumption (VO2) since an Anaerobic CO2 production should occur. Thus the VCO2/VO2 ratio, and hence the venoarterial CO2 tension difference/arteriovenous O2 content difference ratio (ΔPCO2/C(a-v)O2), should increase. We tested the value of the ΔPCO2/C(a-v)O2 ratio in detecting the presence of global Anaerobic Metabolism as defined by an increase in arterial lactate level above 2 mmol/l (Lac+). Design and setting: Retrospective study over a 17-month period in medical intensive care unit of a university hospital. Patients: We obtained 148 sets of measurements in 89 critically ill patients monitored by a pulmonary artery catheter. Results: The ΔPCO2/C(a-v)O2 ratio was higher in those with increased (n=73) than in the normolactatemic group (2.0±0.9 vs. 1.1±0.6, p<0.0001). Among all the O2- and CO2-derived parameters the ΔPCO2/C(a-v)O2 ratio had the highest correlation with the arterial lactate level (r=0.57). Moreover, for a threshold value of 1.4 the ΔPCO2/C(a-v)O2 ratio predicted significantly better than the other parameters (receiver operating characteristic curves) the presence of hyperlactatemia (positive and negative predictive values of 86% and 80%, respectively). The overall survival estimate at 1 month was greater when the ΔPCO2/C(a-v)O2 ratio was less than 1.4 on the first set of measurements (38±10% vs. 20±8%, p<0.01). Conclusion: The ΔPCO2/C(a-v)O2 ratio seems a reliable marker of global Anaerobic Metabolism. Its calculation would be helpful for a better interpretation of pulmonary artery catheter data.
Ricardo Saraiva Louro - One of the best experts on this subject based on the ideXlab platform.
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characterization of the periplasmic redox network that sustains the versatile Anaerobic Metabolism of shewanella oneidensis mr 1
Frontiers in Microbiology, 2015Co-Authors: Monica N Alves, S E Neto, Alexandra S Alves, Uno M Fonseca, Afonso Carrelo, Isabel Pacheco, Catarina M Paquete, Claudio M Soares, Ricardo Saraiva LouroAbstract:The versatile Anaerobic Metabolism of the Gram-negative bacterium Shewanella oneidensis MR-1 (SOMR-1) relies on a multitude of redox proteins found in its periplasm. Most are multiheme cytochromes that carry electrons to terminal reductases of insoluble electron acceptors located at the cell surface, or bona fide terminal reductases of soluble electron acceptors. In this study, the interaction network of several multiheme cytochromes was explored by a combination of NMR spectroscopy, activity assays followed by UV-visible spectroscopy and comparison of surface electrostatic potentials. From these data the small tetraheme cytochrome (STC) emerges as the main periplasmic redox shuttle in SOMR-1. It accepts electrons from CymA and distributes them to a number of terminal oxidoreductases involved in the respiration of various compounds. STC is also involved in the electron transfer pathway to reduce nitrite by interaction with the octaheme tetrathionate reductase (OTR), but not with cytochrome c nitrite reductase (ccNiR). In the main pathway leading the metal respiration STC pairs with flavocytochrome c (FccA), the other major periplasmic cytochrome, which provides redundancy in this important pathway. The data reveals that the two proteins compete for the binding site at the surface of MtrA, the decaheme cytochrome inserted on the periplasmic side of the MtrCAB-OmcA outer-membrane complex. However, this is not observed for the MtrA homologues. Indeed, neither STC nor FccA interact with MtrD, the best replacement for MtrA, and only STC is able to interact with the decaheme cytochrome DmsE of the outer-membrane complex DmsEFABGH. Overall, these results shown that STC plays a central role in the Anaerobic respiratory Metabolism of SOMR-1. Nonetheless, the trans-periplasmic electron transfer chain is functionally resilient as a consequence of redundancies that arise from the presence of alternative pathways that bypass/compete with STC.
