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Zhao M, Wang X, Wang S, Lu W, He M, Gao M. Long-lasting organics removal via •OH adsorbed transition metal flocs: Electron transfer-mediated H-bond and van der Waals force. Proc Natl Acad Sci U S A 2024; 121:e2403072121. [PMID: 39226340 PMCID: PMC11406266 DOI: 10.1073/pnas.2403072121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Accepted: 07/11/2024] [Indexed: 09/05/2024] Open
Abstract
Homogenous advanced oxidation processes (AOPs) based on transition metal catalysts toward the activation of H2O2 to hydroxyl radical (•OH) have been widely applied to organic pollutants removal, such as Fenton and Fenton-like processes. These transition metal catalysts mostly flocculate as the pH increases. It's worth noting that the formed transition metal flocs are complex heterogeneous aggregations with active substances, providing diverse reaction spaces and interfaces. However, it is a challenge to distinguish the roles of transition metal flocs in the organic pollutants removal from homogeneous catalytic reactions. Herein, we unveiled a pathway for the long-lasting removal of organic pollutants via Cr flocs adsorbed with •OH (HO•-Cr flocs) using a stepwise method. First, adsorbed •OH (•OHads) within the HO•-Cr flocs was proved to be the active site forming hydrogen bond (H-bond) and van der Waals force with organic pollutants. Then, the presence of switchable electron transfer between Cr and OH groups within the HO•-Cr flocs was revealed, contributing to the persistent existence of •OHads and consequently ensuring the long-lasting organics removal. Further, this removal pathway of organic pollutants was confirmed during the leather wastewater treatment. These findings will complement a different pathway for organic pollutants removal via transition metal flocs and extend the lifetime of homogeneous AOPs based on transition metal catalysts, providing significant implications for their design and optimization.
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Affiliation(s)
- Manshu Zhao
- School of Environmental Science and Engineering, Shandong University, Qingdao 266237, China
| | - Xinhua Wang
- School of Environmental Science and Engineering, Shandong University, Qingdao 266237, China
- Shandong Key Laboratory of Environmental Processes and Health, Shandong University, Qingdao 266237, China
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, Shandong University, Qingdao 266237, China
| | - Shuguang Wang
- School of Environmental Science and Engineering, Shandong University, Qingdao 266237, China
- Shandong Key Laboratory of Environmental Processes and Health, Shandong University, Qingdao 266237, China
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, Shandong University, Qingdao 266237, China
| | - Wenhui Lu
- Faculty of Light Industry, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250353, China
| | - Maoxia He
- Environment Research Institute, Shandong University, Qingdao 266237, China
| | - Mingming Gao
- School of Environmental Science and Engineering, Shandong University, Qingdao 266237, China
- Shandong Key Laboratory of Environmental Processes and Health, Shandong University, Qingdao 266237, China
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, Shandong University, Qingdao 266237, China
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Amponsah-Offeh M, Diaba-Nuhoho P, Speier S, Morawietz H. Oxidative Stress, Antioxidants and Hypertension. Antioxidants (Basel) 2023; 12:281. [PMID: 36829839 PMCID: PMC9952760 DOI: 10.3390/antiox12020281] [Citation(s) in RCA: 25] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2022] [Revised: 01/18/2023] [Accepted: 01/22/2023] [Indexed: 01/28/2023] Open
Abstract
As a major cause of morbidity and mortality globally, hypertension remains a serious threat to global public health. Despite the availability of many antihypertensive medications, several hypertensive individuals are resistant to standard treatments, and are unable to control their blood pressure. Regulation of the renin-angiotensin-aldosterone system (RAAS) controlling blood pressure, activation of the immune system triggering inflammation and production of reactive oxygen species, leading to oxidative stress and redox-sensitive signaling, have been implicated in the pathogenesis of hypertension. Thus, besides standard antihypertensive medications, which lower arterial pressure, antioxidant medications were tested to improve antihypertensive treatment. We review and discuss the role of oxidative stress in the pathophysiology of hypertension and the potential use of antioxidants in the management of hypertension and its associated organ damage.
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Affiliation(s)
- Michael Amponsah-Offeh
- Institute of Physiology, Faculty of Medicine Carl Gustav Carus, Technische Universität Dresden, Fetscherstr. 74, 01307 Dresden, Germany
- Department of Cardiovascular Research, European Center for Angioscience (ECAS), Medical Faculty Mannheim, Heidelberg University, 68167 Mannheim, Germany
| | - Patrick Diaba-Nuhoho
- Division of Vascular Endothelium and Microcirculation, Department of Medicine III, University Hospital and Faculty of Medicine Carl Gustav Carus, Technische Universität Dresden, 01307 Dresden, Germany
- Department of Paediatric and Adolescent Medicine, Paediatric Haematology and Oncology, University Hospital Münster, 48149 Münster, Germany
| | - Stephan Speier
- Institute of Physiology, Faculty of Medicine Carl Gustav Carus, Technische Universität Dresden, Fetscherstr. 74, 01307 Dresden, Germany
- Paul Langerhans Institute Dresden (PLID) of the Helmholtz Zentrum München at University Clinic Carl Gustav Carus and Faculty of Medicine, Technische Universität Dresden, Fetscherstr. 74, 01307 Dresden, Germany
- German Center for Diabetes Research (DZD), 85764 München-Neuherberg, Germany
| | - Henning Morawietz
- Division of Vascular Endothelium and Microcirculation, Department of Medicine III, University Hospital and Faculty of Medicine Carl Gustav Carus, Technische Universität Dresden, 01307 Dresden, Germany
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Guan C, Guo Q, Wang Z, Wei X, Han B, Luo X, Pan H, Jiang J. Bisulfite activated permanganate for oxidative water decontamination. WATER RESEARCH 2022; 216:118331. [PMID: 35358879 DOI: 10.1016/j.watres.2022.118331] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 03/17/2022] [Accepted: 03/18/2022] [Indexed: 06/14/2023]
Abstract
Recently, bisulfite-activated permanganate (MnO4-; Mn(VII)) process has attracted considerable attention as a novel class of advanced oxidation technology for destruction of organic contaminants in water. However, disputes over the underlying activation mechanism as well as reactive species generated in the Mn(VII)/bisulfite system remain for a long period due to the fairly complex chemistry involved in this system. This article aims to present a critical review on scientific development of the Mn(VII)/bisulfite system, with particular focus on the generation and contribution of various reactive intermediates. Both reactive manganese species (RMnS) (i.e., soluble Mn(III), Mn(V), and Mn(VI)) and radical species (primarily SO4•-) are identified as the oxidizing components responsible for enhanced degradation of organic contaminants by the Mn(VII)/bisulfite system. Bisulfite plays a dual role of being an activating agent for reactive intermediates generation and acting as a complexing agent to stabilize RMnS. Solution chemistry (e.g., the [Mn(VII)]/[bisulfite] molar ratio, solution pH, the type of contaminants, ligands, and water matrix components) greatly impacts the generation and consumption of RMnS and radicals, thus influencing the degradation kinetics and pathways of organics. Particularly, dissolved oxygen (DO) is a vital factor for driving the oxidation of organics since the absence of DO can block the generation of SO4•- and meantime causes the consumption of RMnS by excess SO3•- as a strong reductant. Interestingly, ferrate (FeO42-, Fe(VI)) and hexavalent chromium (CrO42-/HCrO4-, Cr(VI)) that are high-valent metal oxyanions analogous to Mn(VII) can be activated by bisulfite via a similar pathway (i.e. both high-valent metal-oxo intermediates and reactive radicals are involved). Furthermore, key knowledge gaps are identified and future research needs are proposed to address the potential challenges encountered in practical application of the Mn(VII)/bisulfite oxidation technology.
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Affiliation(s)
- Chaoting Guan
- Key Laboratory for City Cluster Environmental Safety and Green Development of the Ministry of Education, School of Ecology, Environment and Resources, Guangdong University of Technology, Guangzhou 510006, China; Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 511458, China
| | - Qin Guo
- Key Laboratory for City Cluster Environmental Safety and Green Development of the Ministry of Education, School of Ecology, Environment and Resources, Guangdong University of Technology, Guangzhou 510006, China; Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 511458, China
| | - Zhen Wang
- Key Laboratory for City Cluster Environmental Safety and Green Development of the Ministry of Education, School of Ecology, Environment and Resources, Guangdong University of Technology, Guangzhou 510006, China; Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 511458, China
| | - Xipeng Wei
- Key Laboratory for City Cluster Environmental Safety and Green Development of the Ministry of Education, School of Ecology, Environment and Resources, Guangdong University of Technology, Guangzhou 510006, China; Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 511458, China
| | - Bin Han
- Key Laboratory for City Cluster Environmental Safety and Green Development of the Ministry of Education, School of Ecology, Environment and Resources, Guangdong University of Technology, Guangzhou 510006, China; Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 511458, China
| | - Xiaonan Luo
- Key Laboratory for City Cluster Environmental Safety and Green Development of the Ministry of Education, School of Ecology, Environment and Resources, Guangdong University of Technology, Guangzhou 510006, China; Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 511458, China
| | - Hanping Pan
- Key Laboratory for City Cluster Environmental Safety and Green Development of the Ministry of Education, School of Ecology, Environment and Resources, Guangdong University of Technology, Guangzhou 510006, China; Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 511458, China
| | - Jin Jiang
- Key Laboratory for City Cluster Environmental Safety and Green Development of the Ministry of Education, School of Ecology, Environment and Resources, Guangdong University of Technology, Guangzhou 510006, China; Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 511458, China.
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Weaver J, Liu KJ. A Review of Low-Frequency EPR Technology for the Measurement of Brain pO2 and Oxidative Stress. APPLIED MAGNETIC RESONANCE 2021; 52:1379-1394. [PMID: 35340811 PMCID: PMC8945541 DOI: 10.1007/s00723-021-01384-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Revised: 06/24/2021] [Accepted: 06/30/2021] [Indexed: 06/14/2023]
Abstract
EPR can uniquely measure paramagnetic species. Although commercial EPR was introduced in 1950s, the early studies were mostly restricted to chemicals in solution or cellular experiments using X-band EPR equipment. Due to its limited penetration (<1 mm), experiments with living animals were almost impossible. To overcome these difficulties, Swartz group, along with several other leaders in field, pioneered the technology of low frequency EPR (e.g., L-band, 1-2 GHz). The development of low frequency EPR and the associated probes have dramatically expanded the application of EPR technology into the biomedical research field, providing answers to important scientific questions by measuring specific parameters that are impossible or very difficult to obtain by other approaches. In this review, which is aimed at highlighting the seminal contribution from Swartz group over the last several decades, we will focus on the development of EPR technology that was designed to deal with the potential challenges arising from conducting EPR spectroscopy in living animals. The second half of the review will be concentrated on the application of low frequency EPR in measuring cerebral tissue pO2 changes and oxidative stress in various physiological and pathophysiological conditions in the brain of animal disease models.
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Affiliation(s)
- John Weaver
- Department of Pharmaceutical Sciences, College of Pharmacy, University of New Mexico Health Sciences Center, Albuquerque, NM 87131
| | - Ke Jian Liu
- Department of Pharmaceutical Sciences, College of Pharmacy, University of New Mexico Health Sciences Center, Albuquerque, NM 87131
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Dong H, Wei G, Cao T, Shao B, Guan X, Strathmann TJ. Insights into the Oxidation of Organic Cocontaminants during Cr(VI) Reduction by Sulfite: The Overlooked Significance of Cr(V). ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:1157-1166. [PMID: 31858777 DOI: 10.1021/acs.est.9b03356] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Literature works reported that organic cocontaminants could be degraded during Cr(VI), a contaminant, reduction by sulfite (Cr(VI)/sulfite process). However, the role of Cr(V) and Cr(IV) intermediates in the Cr(VI)/sulfite process has been overlooked. In this study, we confirmed the generation of Cr(V) and proposed a new mechanism for the decomposition of coexisting organic contaminants during Cr(VI)/sulfite reactions occurring in oxygenated solutions at pHini 4.0 with the molar ratio of sulfite to Cr(VI) of 10.0. UV-visible and electron paramagnetic resonance (EPR) spectra indicate that Cr(V) was the predominant Cr intermediates in oxygenated solutions, while Cr(IV) accumulated in deoxygenated solutions. The contribution of Cr(V) to the degradation of organic contaminants was verified by the EPR spectra collected at 2 K and using methyl phenyl sulfoxide as a probe compound. Both Cr(V) and SO4•- contributed to the decomposition of organic contaminants in oxygenated solutions, with the relative contributions from each species being strongly dependent on properties of the target organic cocontaminants. The key mechanisms responsible for Cr(V) accumulation were supported by DFT calculations, and the degradation kinetics of organic cocontaminants was simulated with the program Kintecus 6.51. This work advances the fundamental understanding of the oxidative transformation of coexisting organic contaminants in this process.
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Affiliation(s)
- Hongyu Dong
- Shanghai Institute of Pollution Control and Ecological Security , Shanghai 200092 , China
| | | | | | - Binbin Shao
- Shanghai Institute of Pollution Control and Ecological Security , Shanghai 200092 , China
| | - Xiaohong Guan
- Shanghai Institute of Pollution Control and Ecological Security , Shanghai 200092 , China
| | - Timothy J Strathmann
- Department of Civil & Environmental Engineering , Colorado School of Mines , Golden , Colorado 80401 , United States
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6
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Mazumder J, Kizawa Y, Espulgar W, Yoshikawa H, Saito M, Koyama S, Takamatsu H, Kumanogoh A, Tamiya E. Electrochemiluminescence-based Monitoring of Activated Human Neutrophils Using Luminol Derivative Immobilized onto Screen-printed Electrodes. CHEM LETT 2018. [DOI: 10.1246/cl.180600] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
- Joyotu Mazumder
- Department of Applied Physics, Tamiya Laboratory, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Yuka Kizawa
- Department of Applied Physics, Tamiya Laboratory, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Wilfred Espulgar
- Department of Applied Physics, Tamiya Laboratory, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Hiroyuki Yoshikawa
- Department of Applied Physics, Tamiya Laboratory, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Masato Saito
- Department of Applied Physics, Tamiya Laboratory, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
- Advanced Photonics and Biosensing Open Innovation Laboratory, AIST-Osaka University, 2-1 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Shouhei Koyama
- Department of Respiratory Medicine and Clinical Immunology, Graduate School of Medicine, Osaka University, Suita, Osaka 565-0871, Japan
| | - Hyota Takamatsu
- Department of Respiratory Medicine and Clinical Immunology, Graduate School of Medicine, Osaka University, Suita, Osaka 565-0871, Japan
| | - Atsushi Kumanogoh
- Department of Respiratory Medicine and Clinical Immunology, Graduate School of Medicine, Osaka University, Suita, Osaka 565-0871, Japan
| | - Eiichi Tamiya
- Department of Applied Physics, Tamiya Laboratory, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
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7
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Gallez B. Contribution of Harold M. Swartz to In Vivo EPR and EPR Dosimetry. RADIATION PROTECTION DOSIMETRY 2016; 172:16-37. [PMID: 27421469 DOI: 10.1093/rpd/ncw157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
In 2015, we are celebrating half a century of research in the application of Electron Paramagnetic Resonance (EPR) as a biodosimetry tool to evaluate the dose received by irradiated people. During the EPR Biodose 2015 meeting, a special session was organized to acknowledge the pioneering contribution of Harold M. (Hal) Swartz in the field. The article summarizes his main contribution in physiology and medicine. Four emerging themes have been pursued continuously along his career since its beginning: (1) radiation biology; (2) oxygen and oxidation; (3) measuring physiology in vivo; and (4) application of these measurements in clinical medicine. The common feature among all these different subjects has been the use of magnetic resonance techniques, especially EPR. In this article, you will find an impressionist portrait of Hal Swartz with the description of the 'making of' this pioneer, a time-line perspective on his career with the creation of three National Institutes of Health-funded EPR centers, a topic-oriented perspective on his career with a description of his major contributions to Science, his role as a mentor and his influence on his academic children, his active role as founder of scientific societies and organizer of scientific meetings, and the well-deserved international recognition received so far.
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Affiliation(s)
- Bernard Gallez
- Université Catholique de Louvain, Louvain Drug Research Institute, Biomedical Magnetic Resonance Research Group, Avenue Mounier 73.08, B-1200, Brussels, Belgium
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Panth N, Paudel KR, Parajuli K. Reactive Oxygen Species: A Key Hallmark of Cardiovascular Disease. Adv Med 2016; 2016:9152732. [PMID: 27774507 PMCID: PMC5059509 DOI: 10.1155/2016/9152732] [Citation(s) in RCA: 227] [Impact Index Per Article: 28.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Revised: 08/11/2016] [Accepted: 08/24/2016] [Indexed: 02/07/2023] Open
Abstract
Cardiovascular diseases (CVDs) have been the prime cause of mortality worldwide for decades. However, the underlying mechanism of their pathogenesis is not fully clear yet. It has been already established that reactive oxygen species (ROS) play a vital role in the progression of CVDs. ROS are chemically unstable reactive free radicals containing oxygen, normally produced by xanthine oxidase, nicotinamide adenine dinucleotide phosphate oxidase, lipoxygenases, or mitochondria or due to the uncoupling of nitric oxide synthase in vascular cells. When the equilibrium between production of free radicals and antioxidant capacity of human physiology gets altered due to several pathophysiological conditions, oxidative stress is induced, which in turn leads to tissue injury. This review focuses on pathways behind the production of ROS, its involvement in various intracellular signaling cascades leading to several cardiovascular disorders (endothelial dysfunction, ischemia-reperfusion, and atherosclerosis), methods for its detection, and therapeutic strategies for treatment of CVDs targeting the sources of ROS. The information generated by this review aims to provide updated insights into the understanding of the mechanisms behind cardiovascular complications mediated by ROS.
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Affiliation(s)
- Nisha Panth
- Department of Pharmacy, School of Health and Allied Sciences, Pokhara University, Dhungepatan, Kaski 33701, Nepal
| | - Keshav Raj Paudel
- Department of Pharmacy, School of Health and Allied Sciences, Pokhara University, Dhungepatan, Kaski 33701, Nepal
| | - Kalpana Parajuli
- Department of Pharmacy, School of Health and Allied Sciences, Pokhara University, Dhungepatan, Kaski 33701, Nepal
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Dikalov SI, Harrison DG. Methods for detection of mitochondrial and cellular reactive oxygen species. Antioxid Redox Signal 2014; 20:372-82. [PMID: 22978713 PMCID: PMC3887411 DOI: 10.1089/ars.2012.4886] [Citation(s) in RCA: 425] [Impact Index Per Article: 42.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
SIGNIFICANCE Mitochondrial and cellular reactive oxygen species (ROS) play important roles in both physiological and pathological processes. Different ROS, such as superoxide (O2(•-)), hydrogen peroxide, and peroxynitrite (ONOO(-)), stimulate distinct cell-signaling pathways and lead to diverse outcomes depending on their amount and subcellular localization. A variety of methods have been developed for ROS detection; however, many of these methods are not specific, do not allow subcellular localization, and can produce artifacts. In this review, we will critically analyze ROS detection and present advantages and the shortcomings of several available methods. RECENT ADVANCES In the past decade, a number of new fluorescent probes, electron-spin resonance approaches, and immunoassays have been developed. These new state-of-the-art methods provide improved selectivity and subcellular resolution for ROS detection. CRITICAL ISSUES Although new methods for HPLC superoxide detection, application of fluorescent boronate-containing probes, use of cell-targeted hydroxylamine spin probes, and immunospin trapping have been available for several years, there has been lack of translation of these into biomedical research, limiting their widespread use. FUTURE DIRECTIONS Additional studies to translate these new technologies from the test tube to physiological applications are needed and could lead to a wider application of these approaches to study mitochondrial and cellular ROS.
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Affiliation(s)
- Sergey I Dikalov
- Division of Clinical Pharmacology, Vanderbilt University Medical Center , Nashville, Tennessee
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Armstrong JA, Cash N, Soares PMG, Souza MHLP, Sutton R, Criddle DN. Oxidative stress in acute pancreatitis: lost in translation? Free Radic Res 2013; 47:917-33. [PMID: 23952531 DOI: 10.3109/10715762.2013.835046] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Oxidative stress has been implicated in the pathogenesis of acute pancreatitis, a severe and debilitating inflammation of the pancreas that carries a significant mortality, and which imposes a considerable financial burden on the health system due to patient care. Although extensive efforts have been directed towards the elucidation of critical underlying mechanisms and the identification of novel therapeutic targets, the disease remains without a specific therapy. In experimental animal models of acute pancreatitis, increased oxidative stress and decreased antioxidant defences have been observed, changes also detected in patients clinically. However, despite the promise of studies evaluating the effects of antioxidants in these model systems, translation to the clinic has thus far been disappointing. This may reflect many factors involved in the design of both preclinical and clinical evaluations of antioxidant therapy, not least the fact that most experimental studies have focussed on pre-treatment rather than post-injury assessment. This review has examined evidence relating to the involvement of oxidative stress in the pathophysiology of acute pancreatitis, focussing on experimental models and the clinical experience, including the experimental techniques employed and potential of antioxidant therapy.
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Affiliation(s)
- J A Armstrong
- NIHR Liverpool Pancreas Biomedical Research Unit, RLBUHT , Liverpool , UK
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Leinisch F, Ranguelova K, DeRose EF, Jiang J, Mason RP. Evaluation of the Forrester-Hepburn mechanism as an artifact source in ESR spin-trapping. Chem Res Toxicol 2011; 24:2217-26. [PMID: 22004308 PMCID: PMC3412421 DOI: 10.1021/tx2003323] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Nitrone spin traps such as 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) are commonly used for free radical detection. Though proven examples are rare, artifact formation must be considered. For example, the Forrester-Hepburn mechanism yields the same radical adduct as that formed by genuine radical trapping. A hydroxylamine is formed by nucleophilic attack of the substrate on DMPO and subsequently oxidized to the respective nitroxide radical. One potential candidate for this artifact is the sulfur trioxide radical adduct (DMPO/(•)SO(3)(-)), as detected in spin-trapping experiments with horseradish peroxidase and sulfite. It has previously been shown by NMR experiments that the hydroxylamine intermediate does indeed form, but no direct proof for the ESR artifact has been provided. Here, we used isotopically labeled DMPO with horseradish peroxidase and ferricyanide to test for the Forrester-Hepburn artifact directly in a spin-trapping experiment. Besides sulfite, we investigated other nucleophiles such as cyanide, cysteine, and glutathione. Neither sulfite nor biological thiols produced detectable spin-trapping artifacts, but with cyanide the relatively weak signal originated entirely from the nucleophilic reaction. The hydroxylamine intermediate, which is more abundant with cyanide than with sulfite, was identified as cyano-hydroxylamine by means of 2D NMR experiments. Although our study found that spin trapping provided authentic free radical signals with most of the substrates, the occurrence of the Forrester-Hepburn mechanism artifact with cyanide emphasizes the importance of isotope measurements with nucleophile substrates.
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Affiliation(s)
- Fabian Leinisch
- Laboratory of Toxicology and Pharmacology, National Institute of Environmental Health Sciences, National Institutes of Health, 111 T. W. Alexander Drive, Research Triangle Park, North Carolina 27709, USA.
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Staško A, Brezová V, Zalibera M, Biskupič S, Ondriaš K. Electron transfer: A primary step in the reactions of sodium hydrosulphide, an H2S/HS−donor. Free Radic Res 2009; 43:581-93. [DOI: 10.1080/10715760902977416] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Andrej Staško
- Institute of Physical Chemistry and Chemical Physics, Faculty of Chemical and Food Technology, Slovak University of Technology in Bratislava, Radlinského 9, SK-812 37, Bratislava, Slovak Republic
| | - Vlasta Brezová
- Institute of Physical Chemistry and Chemical Physics, Faculty of Chemical and Food Technology, Slovak University of Technology in Bratislava, Radlinského 9, SK-812 37, Bratislava, Slovak Republic
| | - Michal Zalibera
- Institute of Physical Chemistry and Chemical Physics, Faculty of Chemical and Food Technology, Slovak University of Technology in Bratislava, Radlinského 9, SK-812 37, Bratislava, Slovak Republic
| | - Stanislav Biskupič
- Institute of Physical Chemistry and Chemical Physics, Faculty of Chemical and Food Technology, Slovak University of Technology in Bratislava, Radlinského 9, SK-812 37, Bratislava, Slovak Republic
| | - Karol Ondriaš
- Institute of Molecular Physiology and Genetics, Centre of Excellence for Cardiovascular Research, Slovak Academy of Sciences, Vlárska 5, SK-833 34, Bratislava, Slovak Republic
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Potapenko DI, Clanton TL, Bagryanskaya EG, Gritsan NP, Reznikov VA, Khramtsov VV. Nonradical mechanism of (bi)sulfite reaction with DEPMPO: cautionary note for SO3*- radical spin trapping. Free Radic Biol Med 2003; 34:196-206. [PMID: 12521601 DOI: 10.1016/s0891-5849(02)01194-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Knowledge of the formation of radicals from sulfites, in vivo, is of interest in understanding the allergic and inflammatory responses to environmental sulfur dioxide exposure. Sulfite anion trioxide (SO(3)(-*)) radical formation was measured in mice, preloaded with the spin trap, 5-(diethoxy-phosphoryl)-5-methyl-pyrrolidine-N-oxide, (DEPMPO). Based on spin trapping NMR, a surprising quantity of reduced SO(3)(-*)-adduct was observed that did not depend on co-administration of oxidizing agents, suggesting a possible nonradical reaction between (bi)sulfite and DEPMPO. The products of the reversible nucleophylic addition of (bi)sulfite to the nitrone functional group were identified using (31)P-NMR, (1)H-NMR, and (13)C-NMR spectroscopy as cis- and trans- stereoisomers of hydroxylamine and confirmed by quantum chemical calculations. Oxidation of the hydroxylamines results in the formation of two corresponding cis- and trans-isomeric nitroxides, only one of which has been earlier described as the paramagnetic adduct of genuinely trapped SO(3)(-*) radical. The results demonstrate that SO(3)(-*) detection using nitrone spin traps such as DEPMPO and DMPO may involve nonradical addition reactions except in cases when the required controls unambiguously prove a radical mechanism.
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Abstract
The ingredients of oxidative stress include a variety of reactive species such as reactive oxygen and reactive nitrogen species (ROS, RNS). While sulfur is usually considered as part of cellular antioxidant systems there is mounting evidence that reactive sulfur species (RSS) with stressor properties similar to the ones found in ROS are formed under conditions of oxidative stress. Thiols as well as disulfides are easily oxidised to sulfur species with sulfur in higher oxidation states. Such agents include thiyl radicals, disulfides, sulfenic acids and disulfide-S-oxides. They rapidly oxidise and subsequently inhibit thiol-proteins and enzymes and can be considered as a separate class of oxidative stressors providing new antioxidant drug targets.
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15
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Shrivastava HY, Nair BU. Chromium(III)-mediated structural modification of glycoprotein: impact of the ligand and the oxidants. Biochem Biophys Res Commun 2001; 285:915-20. [PMID: 11467838 DOI: 10.1006/bbrc.2001.5258] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The interaction of three types of chromium(III) complexes, [Cr(salen) (H2O2]+, [Cr(en)3]3+, and [Cr(EDTA) (H2O)]- with AGP has been investigated. [Cr(salen) (H2O2]+, [Cr(en)3]3+ and [Cr(EDTA) (H2O]- bind to Human alpha1-acid glycoprotein with a protein:metal ratio of 1:8, 1:6, and 1:4, respectively. The binding constant, K(b) was estimated to be 1.37 +/- 0.12 x 10(5) M(-1), 1.089 +/- 0.05 x 10(5) M(-1) and 5.3 +/- 0.05 x 10(4) M(-1) for [Cr(salen) (H2O2]+, [Cr(en)3]3+, and [Cr(EDTA) (H2O)]-, respectively. [Cr(en)3]3+ has been found to induce structural transition of AGP from the native twisted beta sheet to a more compact alpha-helix. The complexes, [Cr(salen) (H2O2]+ and [Cr(EDTA) (H2O]-, in the presence of H2O2, have been found to bring about nonspecific cleavage of AGP, whereas [Cr(en)3]3+ does not bring about any protein damage. Treatment of [Cr(salen) (H2O)2]+-protein adduct with iodosyl benzene on the other hand led to site specific cleavage of the protein. These results clearly demonstrate that protein damage brought about by chromium(III) complexes depends on the nature of the coordinated ligand, nature of the metal complex, and the nature of the oxidant.
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Affiliation(s)
- H Y Shrivastava
- Chemical Laboratory, Central Leather Research Institute, Chennai, 600 020, India
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16
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Miura Y, Anzai K, Ueda JI, Ozawa T. Pathophysiological significance of in vivo ESR signal decay in brain damage caused by X-irradiation. Radiation effect on nitroxyl decay of a lipophilic spin probe in the head region. BIOCHIMICA ET BIOPHYSICA ACTA 2001; 1525:167-72. [PMID: 11342266 DOI: 10.1016/s0304-4165(00)00184-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
X-irradiation of mice decreased the decay rate of the in vivo ESR signal in the head region to 75% of the control when 3-methoxycarbonyl-2,2,5,5-tetramethylpyrrolidine-1-yloxy (MCPROXYL), a lipophilic and blood-brain barrier-permeable spin probe, was used. We attempted to identify the specific factor responsible for the decrease in the signal decay rate caused by X-irradiation. The signal decay of MCPROXYL in the head region depends on the following three factors: (1) blood concentration of MCPROXYL, (2) reduction to the corresponding hydroxylamine in the brain tissue, and (3) effusion of MCPROXYL from the brain tissue. Irradiation at 15 Gy did not significantly change the rate of decrease of blood concentration of MCPROXYL at 1 h post-irradiation. The reducing activity of the brain homogenate was not changed by the X-irradiation (15 Gy). The contents of MCPROXYL and its hydroxylamine derivative in the brain of 15 Gy-irradiated mice remained higher than in non-irradiated mice. These findings suggest that the effect of X-irradiation observed by in vivo ESR is attributable not to the redox reaction of MCPROXYL in the brain but to the change of the efflux rate of the MCPROXYL from the brain.
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Affiliation(s)
- Y Miura
- Department of Bioregulation Research, National Institute of Radiological Sciences, Chiba, Japan
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17
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Timmins GS, Liu KJ, Bechara EJ, Kotake Y, Swartz HM. Trapping of free radicals with direct in vivo EPR detection: a comparison of 5,5-dimethyl-1-pyrroline-N-oxide and 5-diethoxyphosphoryl-5-methyl-1-pyrroline-N-oxide as spin traps for HO* and SO4*-. Free Radic Biol Med 1999; 27:329-33. [PMID: 10468206 DOI: 10.1016/s0891-5849(99)00049-0] [Citation(s) in RCA: 144] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
To spin trap hydroxyl radical (HO*) with in vivo detection of the resultant radical adducts, the use of two spin traps, 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) and 5-diethoxyphosphoryl-5-methyl-1-pyrroline-N-oxide (DEPMPO) (10 mmol/kg) has been compared. In mice treatment with 5-aminolevulinic acid and Fe3+ resulted in detection of adducts of hydroxyl radicals (HO*), but only with use of DEPMPO. Similarly, 'HO* adducts' generated via nucleophilic substitution of SO4*- adducts formed in vivo could be observed only when using DEPMPO as the spin trap. The reasons for the differences observed between DEPMPO and DMPO are likely due to different in vivo lifetimes of their hydroxyl radical adducts. These results seem to be the first direct in vivo EPR detection of hydroxyl radical adducts.
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Affiliation(s)
- G S Timmins
- EPR Center for the Study of Viable Systems, Dartmouth Medical School, Hanover, NH 03755, USA
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18
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Chamulitrat W. Activation of the superoxide-generating NADPH oxidase of intestinal lymphocytes produces highly reactive free radicals from sulfite. Free Radic Biol Med 1999; 27:411-21. [PMID: 10468216 DOI: 10.1016/s0891-5849(99)00088-x] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The objective of this study was to investigate the ability of immune cells of the small intestine to produce highly reactive free radicals from the food additive sulfites. These free radicals were characterized with a spin-trapping technique using the spin traps 5-diethoxyphosphoryl-5-methyl-1-pyrroline N-oxide (DEPMPO) and 5,5-dimethyl-1-pyrroline N-oxide (DMPO). In the presence of glucose, purified lymphocytes from intestinal Peyer's patches (PP) and mesenteric lymph nodes (MLN) were stimulated with phorbol 12-myristate 13-acetate (PMA) to produce superoxide and hydroxyl DEPMPO radical adducts. The formation of these adducts was inhibited by superoxide dismutase or diphenyleneiodonium chloride, indicating that these cells produced superoxide radical during reduced nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activation. With the treatment of sodium sulfite, PMA-stimulated PP lymphocytes produced a DEPMPO-sulfite radical adduct and an unknown radical adduct. When DEPMPO was replaced with DMPO, DMPO-sulfite and hydroxyl radical adducts were detected. The latter adduct resulted from DMPO oxidation by sulfate radical, which was capable of oxidizing formate or ethanol. Oxygen consumption rates were further increased after the addition of sulfite to PMA-stimulated lymphocytes, suggesting the presence of sulfiteperoxyl radical. Taken together, oxidants generated by stimulated lymphocytes oxidized sulfite to sulfite radical, which subsequently formed sulfiteperoxyl and sulfate radicals. The latter two radicals are highly reactive, contributing to increased oxidative stress, which may lead to sulfite toxicity, altered functions in intestinal lymphocytes, or both.
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Affiliation(s)
- W Chamulitrat
- Department of Physiology, Louisiana State University Medical Center, New Orleans 70112-1393, USA.
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19
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Nishino N, Yasui H, Sakurai H. In vivo L-band ESR and quantitative pharmacokinetic analysis of stable spin probes in rats and mice. Free Radic Res 1999; 31:35-51. [PMID: 10489118 DOI: 10.1080/10715769900300581] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Free radical species in animals have been measured by X-band ESR spectrometric method on a block of organs or a portion of homogenized samples. However, a nondestructive in vivo ESR measurement has been realized by using a recently developed L-band ESR spectrometry. With this L-band ESR method, we measured ESR spectra in animals, who received stable nitroxide radicals. L-band ESR spectra were observed at the upper abdomen of mice as well as at the heads of mice and rats at various ages immediately after the intravenous injections of nitroxide radicals such as 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl (4-hydroxy-TEMPO) and 3-carbamoyl-2,2,5,5-tetramethylpyrrolidine-1-oxyl (3-carbamoyl-PROXYL), in which ESR measurements of the radicals were performed noninvasively at the real time. On the basis of the observed time-dependent free radical clearance curves, the following important results were obtained: (1) Free radical clearances were able to analyze by the pharmacokinetic method. (2) The radicals at the head of mice, given 4-hydroxy-TEMPO, were determined quantitatively by a new analytical method using L-band ESR for the first time. (3) The elimination of the radical was found to be saturated in mice. (4) The clearance rate constant of 4-hydroxy-TEMPO detected at the head of mice was decreased in dose- and age-dependent manners. While, no age-dependent clearance rate constant of 4-hydroxy-TEMPO was observed at the upper abdomen of mice. (5) Ratios of the amount of the detected radicals to that of the administered radicals were decreased age-dependently, but they were independent of the dose of the radicals, suggesting the age-dependent decrease of distribution capacity ratio of the radical at the head of animals. (6) Clearance rate constants of 4-hydroxy-TEMPO and 3-carbamoyl-PROXYL, that were estimated by X- and L-band ESR for the collected blood of mice and rats, were found to be remarkably smaller than those in whole living animals observed by in vivo L-band ESR method. The results suggest that the clearance of the nitroxide radical is relevant to the alteration of the radical in animals following the change of organ distribution and metabolism. (7) Both the radical and its corresponding hydroxylamine, which is the reduced form of the radical, were detectable by X-band ESR method in the collected urine of mice and rats without and with an oxidizing agent, respectively. On the basis of the results on L-band ESR spectrometry, the first quantitative pharmacokinetic analysis of stable spin probes in animals is proposed.
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Affiliation(s)
- N Nishino
- Department of Analytical and Bioinorganic Chemistry, Kyoto Pharmaceutical University, Japan
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20
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Liu KJ, Kotake Y, Lee M, Miyake M, Sugden K, Yu Z, Swartz HM. High-performance liquid chromatography study of the pharmacokinetics of various spin traps for application to in vivo spin trapping. Free Radic Biol Med 1999; 27:82-9. [PMID: 10443923 DOI: 10.1016/s0891-5849(99)00042-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
In vivo spin trapping is potentially a very useful tool to investigate the role of free radicals in physiologic processes and disease development. Unfortunately, knowledge on the stability and distribution of spin traps in living systems is limited. Therefore, in our study, we selected 11 acyclic and cyclic nitrone spin traps with diverse properties to determine their pharmacokinetics in mice. At varying times after intraperitoneal administration, we measured the concentration of the spin traps in the liver, heart, and blood. Our results showed that most spin traps were rapidly absorbed and were approximately evenly distributed throughout the mouse body. It was also found that most of the traps were relatively stable in vivo with more than half of the injected amount still available for spin trapping free radicals after an hour. Two of the 11 tested spin traps, however, decomposed after injection. These results indicate that for a successful in vivo spin trapping experiment, the stability of the spin trap is not of major concern, but the time course of distribution may be important.
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Affiliation(s)
- K J Liu
- Department of Radiology, Dartmouth College, Hanover, NH 03755, USA.
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21
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Abstract
Cellular toxicity, pharmacokinetics, and the in vitro and in vivo stability of the SO3*- spin adduct of the spin trap, 5-diethoxyphosphoryl-5-methyl-1-pyrroline-n-oxide (DEPMPO), was investigated, and the results were compared with those of the widely used spin trap 5,5-dimethyl-1-pyrroline-N-oxide (DMPO). Similar to DMPO, DEPMPO was quickly taken up (<15 min) after intraperitoneal injection, and distributed evenly in the liver, heart, and blood of the mice. In the presence of ascorbate the in vitro stability of the adduct DEPMPO/SO3*- was 7 times better than DMPO/SO3*-. Under in vivo conditions, the spin adduct DEPMPO/SO3*- was 2-4 times more stable than DMPO/ SO3*-, depending on the route of administration of the adducts. Using a low frequency EPR spectrometer, we were able to observe the spin trapped SO3*- radical both with DMPO and DEPMPO directly in the intact mouse. DEPMPO had a detectable spin adduct signal at a concentration as low as 1 mM, as compared to 5 mM for DMPO. We conclude that DEPMPO is potentially a good candidate for trapping radicals in functioning biological systems, and represents an improvement over the commonly used trap DMPO.
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Affiliation(s)
- K J Liu
- Department of Radiology, Dartmouth Medical School, Hanover, NH 03755, USA.
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22
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Swartz HM, Walczak T. Developing in vivo EPR oximetry for clinical use. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1999; 454:243-52. [PMID: 9889898 DOI: 10.1007/978-1-4615-4863-8_29] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
This paper describes the rationale for carrying out electron paramagnetic resonance (EPR) oximetry studies in human subjects in the clinical setting and the potential approaches and specific steps needed to make such studies feasible and useful. While the approach is described specifically for EPR oximetry, many of the principles may apply to the initial clinical uses of other techniques. The suggested operational approach is to have the initial applications occur in as clinically useful and simple a manner as possible, with the expectation that once the technique is introduced and accepted in the clinical setting, that more complex and/or more technically difficult applications will be able to be developed. The initial approach will be based on EPR spectroscopy at 1.2 GHz focusing on applications for which in vivo EPR provides a clearly useful approach to important clinical problems for which currently there is no good alternative method. The EPR measurements can be carried out non-invasively by measurements within 10 mm of the surface after the placement of the paramagnetic material at the site of interest, or by the placement of a needle/catheter in the site of interest for the required time period. The suggested initial clinical applications are guiding therapy for individual patients with tumors or vascular disease, by direct measurements of tissue pO2.
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Affiliation(s)
- H M Swartz
- Department of Radiology, Dartmouth Medical School, Hanover, New Hampshire 03755, USA
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23
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Abstract
The aim of this article is to discuss the applications of in vivo EPR in the field of pharmacy. In addition to direct detection of free radical metabolites and measurement of oxygen, EPR can be used to characterize the mechanisms of drug release from biodegradable polymers. Unique information about drug concentration, the microenvironment (viscosity, polarity, pH) and biodistribution (by localized measurement or EPR Imaging) can be obtained.
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Affiliation(s)
- K Mäder
- Philipps University Marburg, Department of Pharmaceutics and Biopharmacy, Germany
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24
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Quaresima V, Ferrari M. Current status of electron spin resonance (ESR) for in vivo detection of free radicals. Phys Med Biol 1998; 43:1937-47. [PMID: 9703057 DOI: 10.1088/0031-9155/43/7/015] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Much outstanding progress concerning the application of ESR spectroscopy/imaging in the biomedical field has been made in recent years. The literature in this field has already been specifically covered by several reviews. The aim of this article is to provide an overview of the most important findings, obtained in the last four years, in the detection and localization of different exogenous free radicals, as well as of endogenous free radicals in diverse experimental animal models.
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Affiliation(s)
- V Quaresima
- Dipartimento di Scienze e Tecnologie Biomediche, Università di L'Aquila, Italy.
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25
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Swartz HM, Dunn J, Grinberg O, O'Hara J, Walczak T. What does EPR oximetry with solid particles measure--and how does this relate to other measures of PO2? ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1998; 428:663-70. [PMID: 9500113 DOI: 10.1007/978-1-4615-5399-1_93] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- H M Swartz
- Department of Radiology, Dartmouth Medical School, Hanover, New Hampshire 03755, USA
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26
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Sugden KD, Wetterhahn KE. Identification of the Oxidized Products Formed upon Reaction of Chromium(V) with Thymidine Nucleotides. J Am Chem Soc 1996. [DOI: 10.1021/ja962428x] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Kent D. Sugden
- Contribution from 6128 Burke Laboratory, Department of Chemistry, Dartmouth College, Hanover, New Hampshire 03755-3564
| | - Karen E. Wetterhahn
- Contribution from 6128 Burke Laboratory, Department of Chemistry, Dartmouth College, Hanover, New Hampshire 03755-3564
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27
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Mäder K, Gallez B, Swartz HM. In vivo EPR: an effective new tool for studying pathophysiology, physiology and pharmacology. Appl Radiat Isot 1996; 47:1663-7. [PMID: 9022207 DOI: 10.1016/s0969-8043(96)00237-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The development of spectrometers working at lower frequencies with improved resonators now permits the routine use of non-invasive EPR spectroscopy in vivo. The capabilities of EPR spectra to reflect environmental conditions, combined with the use of paramagnetic materials as selective non-toxic labels, has led to increasingly widespread and productive applications of the technique to complex problems involving physiology, pharmacology and pathophysiology. Some of the especially promising applications in which EPR techniques uniquely appear to provide valuable information are illustrated, including the measurement of oxygen and oxygen gradients, monitoring of the metabolism of xenobiotics, monitoring pharmacokinetics of drugs, measurement of perfusion, measurement of pH, recognition and labeling of receptors, and characterization of drug releasing systems.
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Affiliation(s)
- K Mäder
- Department of Radiology, Dartmouth Medical School, Hanover, NH 03755, USA
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28
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Gallez B, Mäder K, Swartz HM. Noninvasive measurement of the pH inside the gut by using pH-sensitive nitroxides. An in vivo EPR study. Magn Reson Med 1996; 36:694-7. [PMID: 8916019 DOI: 10.1002/mrm.1910360507] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The use of pH-sensitive probes permits the measurement of the proton activity in biological systems by EPR spectroscopy. To illustrate the potential of this technique for in vivo purposes, the authors took advantage of the oral administration of nitroxides to monitor the pH value inside the stomach of mice after administration of different antacidics. The results indicate that EPR can be a valuable tool to characterize the pH in vivo in a continuous and noninvasive way.
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Affiliation(s)
- B Gallez
- Department of Medicinal Chemistry, University of Louvain, Brussels, Belgium
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29
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Sugden KD, Wetterhahn KE. EPR Evidence for Chromium(V) Binding to Phosphate and Pyrophosphate: Implications for Chromium(V)-DNA Interactions. Inorg Chem 1996; 35:3727-3728. [PMID: 11666556 DOI: 10.1021/ic960199+] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Kent D. Sugden
- 6128 Burke Laboratory, Department of Chemistry, Dartmouth College, Hanover, New Hampshire 03755-3564
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30
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Jiang JJ, Liu KJ, Swartz HM. Low frequency epr surface probe based on dielectric resonator. RESEARCH ON CHEMICAL INTERMEDIATES 1996. [DOI: 10.1163/156856796x00160] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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31
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Swartz HM, Walczak T. An overview of considerations and approaches for developing in vivo EPR for clinical applications. RESEARCH ON CHEMICAL INTERMEDIATES 1996. [DOI: 10.1163/156856796x00719] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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32
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Liu KJ, Jiang JJ, Ji LL, Shi X, Swartz HM. An HPLC and EPR investigation on the stability of DMPO and DMPO spin adducts in vivo. RESEARCH ON CHEMICAL INTERMEDIATES 1996. [DOI: 10.1163/156856796x00700] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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