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Duraj T, Carrión-Navarro J, Seyfried TN, García-Romero N, Ayuso-Sacido A. Metabolic therapy and bioenergetic analysis: The missing piece of the puzzle. Mol Metab 2021; 54:101389. [PMID: 34749013 PMCID: PMC8637646 DOI: 10.1016/j.molmet.2021.101389] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Revised: 10/29/2021] [Accepted: 11/01/2021] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Aberrant metabolism is recognized as a hallmark of cancer, a pillar necessary for cellular proliferation. Regarding bioenergetics (ATP generation), most cancers display a preference not only toward aerobic glycolysis ("Warburg effect") and glutaminolysis (mitochondrial substrate level-phosphorylation) but also toward other metabolites such as lactate, pyruvate, and fat-derived sources. These secondary metabolites can assist in proliferation but cannot fully cover ATP demands. SCOPE OF REVIEW The concept of a static metabolic profile is challenged by instances of heterogeneity and flexibility to meet fuel/anaplerotic demands. Although metabolic therapies are a promising tool to improve therapeutic outcomes, either via pharmacological targets or press-pulse interventions, metabolic plasticity is rarely considered. Lack of bioenergetic analysis in vitro and patient-derived models is hindering translational potential. Here, we review the bioenergetics of cancer and propose a simple analysis of major metabolic pathways, encompassing both affordable and advanced techniques. A comprehensive compendium of Seahorse XF bioenergetic measurements is presented for the first time. MAJOR CONCLUSIONS Standardization of principal readouts might help researchers to collect a complete metabolic picture of cancer using the most appropriate methods depending on the sample of interest.
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Affiliation(s)
- Tomás Duraj
- Faculty of Medicine, Institute for Applied Molecular Medicine (IMMA), CEU San Pablo University, 28668, Madrid, Spain.
| | - Josefa Carrión-Navarro
- Faculty of Experimental Sciences, Universidad Francisco de Vitoria, 28223, Madrid, Spain; Brain Tumor Laboratory, Fundación Vithas, Grupo Hospitales Vithas, 28043, Madrid, Spain.
| | - Thomas N Seyfried
- Biology Department, Boston College, 140 Commonwealth Ave, Chestnut Hill, MA, 02467, USA.
| | - Noemí García-Romero
- Faculty of Experimental Sciences, Universidad Francisco de Vitoria, 28223, Madrid, Spain; Brain Tumor Laboratory, Fundación Vithas, Grupo Hospitales Vithas, 28043, Madrid, Spain.
| | - Angel Ayuso-Sacido
- Faculty of Experimental Sciences, Universidad Francisco de Vitoria, 28223, Madrid, Spain; Brain Tumor Laboratory, Fundación Vithas, Grupo Hospitales Vithas, 28043, Madrid, Spain; Faculty of Medicine, Universidad Francisco de Vitoria, 28223, Madrid, Spain.
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Cantow K, Evans RG, Grosenick D, Gladytz T, Niendorf T, Flemming B, Seeliger E. Quantitative Assessment of Renal Perfusion and Oxygenation by Invasive Probes: Basic Concepts. Methods Mol Biol 2021; 2216:89-107. [PMID: 33475996 PMCID: PMC9703258 DOI: 10.1007/978-1-0716-0978-1_6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/21/2023]
Abstract
Renal tissue hypoperfusion and hypoxia are early key elements in the pathophysiology of acute kidney injury of various origins, and may also promote progression from acute injury to chronic kidney disease. Here we describe basic principles of methodology to quantify renal hemodynamics and tissue oxygenation by means of invasive probes in experimental animals. Advantages and disadvantages of the various methods are discussed in the context of the heterogeneity of renal tissue perfusion and oxygenation.This chapter is based upon work from the COST Action PARENCHIMA, a community-driven network funded by the European Cooperation in Science and Technology (COST) program of the European Union, which aims to improve the reproducibility and standardization of renal MRI biomarkers. This introduction chapter is complemented by a separate chapter describing the experimental procedure and data analysis.
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Affiliation(s)
- Kathleen Cantow
- Working Group Integrative Kidney Physiology, Institute of Physiology, Charité-University Medicine Berlin, Berlin, Germany
| | - Roger G Evans
- Cardiovascular Disease Program, Biomedicine Discovery Institute and Department of Physiology, Monash University, Melbourne, Australia
| | - Dirk Grosenick
- Physikalisch-Technische Bundesanstalt (German Federal Metrologic Institute), Berlin, Germany
| | - Thomas Gladytz
- Physikalisch-Technische Bundesanstalt (German Federal Metrologic Institute), Berlin, Germany
| | - Thoralf Niendorf
- Berlin Ultrahigh Field Facility (B.U.F.F.), Max Delbrück Center for Molecular Medicine (MDC) in the Helmholtz Association, Berlin, Germany
| | - Bert Flemming
- Working Group Integrative Kidney Physiology, Institute of Physiology, Charité-University Medicine Berlin, Berlin, Germany
| | - Erdmann Seeliger
- Working Group Integrative Kidney Physiology, Institute of Physiology, Charité-University Medicine Berlin, Berlin, Germany.
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Zang L, Zhao H. Lutetium-containing sinoporphyrin sodium: a water-soluble photosensitizer with balanced fluorescence and phosphorescence for ratiometric oxygen sensing. RSC Adv 2020; 10:32938-32945. [PMID: 35516503 PMCID: PMC9056626 DOI: 10.1039/d0ra05400c] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2020] [Accepted: 08/25/2020] [Indexed: 12/26/2022] Open
Abstract
Development of a photosensitizer for ratiometric O2 sensing is desirable for the precise treatment of cancer by photodynamic therapy. Herein, lutetium(iii)-containing sinoporphyrin sodium (Lu-DVDMS) was designed as a phosphorescent photosensitizer to balance phosphorescence and fluorescence emissions for ratiometric O2 sensing. Lu-DVDMS exhibited high water solubility, chemical stability, photostability, photosensitivity, and singlet-oxygen quantum yield of 0.23 ± 0.06. The phosphorescence and fluorescence quantum yields of Lu-DVDMS were 0.33 and 0.32%, respectively. Compared with the phosphorescence-to-fluorescence ratio (R) of gadolinium-DVDMS (Gd-DVDMS), which was >10, that of Lu-DVDMS was ∼1, facilitating ratiometric O2 sensing. The relatively weak phosphorescence-inducing effect of Lu(iii) owing to the absence of paramagnetism, as compared to Gd(iii), balanced the phosphorescence and fluorescence emissions of Lu-DVDMS. The fluctuation of R for Lu-DVDMS was approximately one-sixth of Gd-DVDMS, owing to the high signal-to-noise ratio simultaneously achieved for both phosphorescence and fluorescence emissions. The intensity and lifetime Stern–Volmer plots for Lu-DVDMS were 0.9840 + 0.0024[O2] and 0.9517 + 0.0034[O2], respectively ([O2]: oxygen concentration). Fast response and recovery times (<2 min) were achieved. The precision of oxygen detection using Lu-DVDMS was better than 0.5 μM in the 0–400 μM oxygen detection range. Therefore, Lu-DVDMS is a potential phosphorescent photosensitizer for ratiometric O2 sensing. A lutetium(iii)-porphyrin was designed as a phosphorescent photosensitizer to balance phosphorescence and fluorescence emissions for ratiometric O2 sensing.![]()
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Affiliation(s)
- Lixin Zang
- College of Chemistry, Chemical Engineering and Materials Science, Collaborative Innovation Center of Functionalized Probes for Chemical Imaging in Universities of Shandong, Key Laboratory of Molecular and Nano Probes, Ministry of Education, Shandong Provincial Key Laboratory of Clean Production of Fine Chemicals, Shandong Normal University Ji'nan 250014 China
| | - Huimin Zhao
- Shandong Provincial Engineering and Technical Center of Light Manipulations, Shandong Provincial Key Laboratory of Optics and Photonic Device, School of Physics and Electronics, Shandong Normal University Ji'nan 250014 China
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Helm I, Karina G, Jalukse L, Pagano T, Leito I. Comparative validation of amperometric and optical analyzers of dissolved oxygen: a case study. ENVIRONMENTAL MONITORING AND ASSESSMENT 2018; 190:313. [PMID: 29705878 DOI: 10.1007/s10661-018-6692-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Accepted: 04/16/2018] [Indexed: 05/27/2023]
Abstract
A comprehensive comparative validation for two different types of dissolved oxygen (DO) analyzers, amperometric and optical, is presented on two representative commercial DO analyzers. A number of performance characteristics were evaluated including drift, intermediate precision, accuracy of temperature compensation, accuracy of reading (under different measurement conditions), linearity, flow dependence of the reading, repeatability (reading stability), and matrix effects of dissolved salts. The matrix effects on readings in real samples were evaluated by analyzing the dependence of the reading on salt concentration (at saturation concentration of DO). The analyzers were also assessed in DO measurements of a number of natural waters. The uncertainty contributions of the main influencing parameters were estimated under different experimental conditions. It was found that the uncertainties of results for both analyzers are quite similar but the contributions of the uncertainty sources are different. Our results imply that the optical analyzer might not be as robust as is commonly assumed; however, it has better reading stability, lower stirring speed dependence, and typically requires less maintenance. On the other hand, the amperometric analyzer has a faster response and wider linear range. Both analyzers seem to have issues with the accuracy of temperature compensation. The approach described in this work will be useful to practitioners carrying out DO measurements for ensuring reliability of their measurements.
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Affiliation(s)
- Irja Helm
- Institute of Chemistry, University of Tartu, Ravila 14a, 50411, Tartu, Estonia
| | - Gerli Karina
- Institute of Chemistry, University of Tartu, Ravila 14a, 50411, Tartu, Estonia
- Estonian Veterinary and Food Laboratory, Kreutzwaldi 30, 51006, Tartu, Estonia
| | - Lauri Jalukse
- Institute of Chemistry, University of Tartu, Ravila 14a, 50411, Tartu, Estonia
- Estonian Veterinary and Food Laboratory, Kreutzwaldi 30, 51006, Tartu, Estonia
| | - Todd Pagano
- Department of Science & Mathematics, Rochester Institute of Technology, Rochester, NY, 14623, USA
| | - Ivo Leito
- Institute of Chemistry, University of Tartu, Ravila 14a, 50411, Tartu, Estonia.
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An Effective, Versatile, and Inexpensive Device for Oxygen Uptake Measurement. J Clin Med 2017; 6:jcm6060058. [PMID: 28594349 PMCID: PMC5483868 DOI: 10.3390/jcm6060058] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Revised: 05/19/2017] [Accepted: 06/06/2017] [Indexed: 12/28/2022] Open
Abstract
In the last ten years, the use of fluorescent probes developed to measure oxygen has resulted in several marketed devices, some unreasonably expensive and with little flexibility. We have explored the use of the effective, versatile, and inexpensive Redflash technology to determine oxygen uptake by a number of different biological samples using various layouts. This technology relies on the use of an optic fiber equipped at its tip with a membrane coated with a fluorescent dye (www.pyro-science.com). This oxygen-sensitive dye uses red light excitation and lifetime detection in the near infrared. So far, the use of this technology has mostly been used to determine oxygen concentration in open spaces for environmental studies, especially in aquatic media. The oxygen uptake determined by the device can be easily assessed in small volumes of respiration medium and combined with the measurement of additional parameters, such as lactate excretion by intact cells or the membrane potential of purified mitochondria. We conclude that the performance of by this technology should make it a first choice in the context of both fundamental studies and investigations for respiratory chain deficiencies in human samples.
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Abstract
Molecular oxygen (O2) is essential to brain function and mechanisms necessary to regulate variations in delivery or utilization of O2 are crucial to support normal brain homeostasis, physiology and energy metabolism. Any imbalance in cerebral tissue partial pressure of O2 (pO2) levels may lead to pathophysiological complications including increased reactive O2 species generation leading to oxidative stress when tissue O2 level is too high or too low. Accordingly, the need for oximetry methods, which assess cerebral pO2in vivo and in real time, is imperative to understand the role of O2 in various metabolic and disease states, including the effects of treatment and therapy options. In this review, we provide a brief overview of the common in vivo oximetry methodologies for measuring cerebral pO2. We discuss the advantages and limitations of oximetry methodologies to measure cerebral pO2in vivo followed by a more in-depth review of electron paramagnetic resonance oximetry spectroscopy and imaging using several examples of current electron paramagnetic resonance oximetry applications in the brain.
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Affiliation(s)
- John M Weaver
- Department of Pharmaceutical Sciences, College of Pharmacy, University of New Mexico Health Sciences Center, Albuquerque, NM, USA.,Center of Biomedical Research Excellence, College of Pharmacy, University of New Mexico Health Sciences Center, Albuquerque, NM, USA
| | - Ke Jian Liu
- Department of Pharmaceutical Sciences, College of Pharmacy, University of New Mexico Health Sciences Center, Albuquerque, NM, USA.,Center of Biomedical Research Excellence, College of Pharmacy, University of New Mexico Health Sciences Center, Albuquerque, NM, USA.,Department of Neurology, University of New Mexico Health Sciences Center, Albuquerque, NM, USA
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Einstein SA, Weegman BP, Firpo MT, Papas KK, Garwood M. Development and Validation of Noninvasive Magnetic Resonance Relaxometry for the In Vivo Assessment of Tissue-Engineered Graft Oxygenation. Tissue Eng Part C Methods 2016; 22:1009-1017. [PMID: 27758135 PMCID: PMC5116663 DOI: 10.1089/ten.tec.2016.0106] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Accepted: 09/26/2016] [Indexed: 11/12/2022] Open
Abstract
Techniques to monitor the oxygen partial pressure (pO2) within implanted tissue-engineered grafts (TEGs) are critically necessary for TEG development, but current methods are invasive and inaccurate. In this study, we developed an accurate and noninvasive technique to monitor TEG pO2 utilizing proton (1H) or fluorine (19F) magnetic resonance spectroscopy (MRS) relaxometry. The value of the spin-lattice relaxation rate constant (R1) of some biocompatible compounds is sensitive to dissolved oxygen (and temperature), while insensitive to other external factors. Through this physical mechanism, MRS can measure the pO2 of implanted TEGs. We evaluated six potential MRS pO2 probes and measured their oxygen and temperature sensitivities and their intrinsic R1 values at 16.4 T. Acellular TEGs were constructed by emulsifying porcine plasma with perfluoro-15-crown-5-ether, injecting the emulsion into a macroencapsulation device, and cross-linking the plasma with a thrombin solution. A multiparametric calibration equation containing R1, pO2, and temperature was empirically generated from MRS data and validated with fiber optic (FO) probes in vitro. TEGs were then implanted in a dorsal subcutaneous pocket in a murine model and evaluated with MRS up to 29 days postimplantation. R1 measurements from the TEGs were converted to pO2 values using the established calibration equation and these in vivo pO2 measurements were simultaneously validated with FO probes. Additionally, MRS was used to detect increased pO2 within implanted TEGs that received supplemental oxygen delivery. Finally, based on a comparison of our MRS data with previously reported data, ultra-high-field (16.4 T) is shown to have an advantage for measuring hypoxia with 19F MRS. Results from this study show MRS relaxometry to be a precise, accurate, and noninvasive technique to monitor TEG pO2 in vitro and in vivo.
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Affiliation(s)
- Samuel A. Einstein
- Department of Radiology, Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, Minnesota
| | - Bradley P. Weegman
- Department of Radiology, Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, Minnesota
| | - Meri T. Firpo
- Department of Medicine, Stem Cell Institute, University of Minnesota, Minneapolis, Minnesota
| | | | - Michael Garwood
- Department of Radiology, Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, Minnesota
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Okusa MD, Jaber BL, Doran P, Duranteau J, Yang L, Murray PT, Mehta RL, Ince C. Physiological biomarkers of acute kidney injury: a conceptual approach to improving outcomes. CONTRIBUTIONS TO NEPHROLOGY 2013; 182:65-81. [PMID: 23689656 DOI: 10.1159/000349967] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The past 5-10 years have brought significant advances in the identification and validation of novel biochemical biomarkers in the prevention and treatment of acute kidney injury (AKI). These biochemical biomarkers remain research tools but we anticipate that soon they will be employed in clinical practice. A Consensus Conference held by the Acute Dialysis Quality Initiative (ADQI) recently reviewed the evidence, and identified gaps and a research agenda. Furthermore, at this meeting was the birth of an initiative to comprehensively identify new opportunities to characterize the physiological changes during the course of AKI based upon a conceptual framework for the detection and monitoring of renal ischemia-reperfusion injury. This framework includes a transition from monitoring physiological biomarkers of adequate renal perfusion, to pathophysiologic biomarkers of renal hypoperfusion, and finally biomarkers of kidney cell structural injury/damage. Techniques to measure physiological changes in AKI include several physiological variables that might be used in an interactive way to supplement clinical information and biochemical damage biomarkers in the diagnosis and management of AKI. This review summarizes the spectrum of physiological parameters and potential new physiological methods that enable identification of high-risk patients for AKI, facilitate early diagnosis, and differential diagnosis to guide therapeutic management and prognostication. Finally, we propose a research agenda for the next 5 years to facilitate the development and validation of physiological biomarkers in AKI.
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Affiliation(s)
- Mark D Okusa
- Division of Nephrology and Center for Immunity, Inflammation and Regenerative Medicine, University of Virginia, Charlottesville, Va., USA.
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Yang Y, Guo Q, Chen H, Zhou Z, Guo Z, Shen Z. Thienopyrrole-expanded BODIPY as a potential NIR photosensitizer for photodynamic therapy. Chem Commun (Camb) 2013; 49:3940-2. [DOI: 10.1039/c3cc40746b] [Citation(s) in RCA: 159] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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Siasios I, Kapsalaki EZ, Fountas KN. The role of intraoperative micro-Doppler ultrasound in verifying proper clip placement in intracranial aneurysm surgery. Neuroradiology 2012; 54:1109-18. [PMID: 22415343 DOI: 10.1007/s00234-012-1023-y] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2011] [Accepted: 02/24/2012] [Indexed: 12/29/2022]
Abstract
INTRODUCTION Aneurysmal subarachnoid hemorrhage constitutes a clinical entity associated with high mortality and morbidity. It is widely accepted that improper clip placement may have as a result of incomplete aneurysm occlusion and/or partial or complete obstruction of an adjacent vessel. Various modalities, including intraoperative or postoperative digital subtracting angiography, near-infrared indocyanine green angiography, micro-Doppler ultrasonography (MDU), and neurophysiological studies, have been utilized for verifying proper clip placement. The aim of our study was to review the role of MDU during aneurysmal surgery. METHODS A literature search was performed using any possible combination of the following terms: "aneurysm," "brain," "cerebral," "clip," "clipping," "clip malpositioning," "clip repositioning," "clip suboptimal positioning," "Doppler," "intracranial," "microsurgery," "micro-Doppler," "residual neck," "ultrasonography," "ultrasound," and "vessel occlusion". Additionally, reference lists from the retrieved articles were reviewed for identifying any additional articles. Case reports and miniseries were excluded. RESULTS A total of 19 series employing intraoperative MDU during aneurysmal microsurgery were retrieved. All studies demonstrated that MDU accuracy is extremely high. The highest reported false-positive rate of MDU was 2 %, while the false-negative rate was reported as high as 1.6 %. It has been demonstrated that the presence of subarachnoid hemorrhage, specific anatomic locations, and large size may predispose to improper clip placement. Intraoperative MDU's technical limitations and weaknesses are adequately identified, in order to minimize the possibility of any misinterpretations. CONCLUSION Intraoperative MDU constitutes a safe, accurate, and low cost imaging modality for evaluating blood flow and for verifying proper clip placement during microsurgical clipping.
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Affiliation(s)
- Ioannis Siasios
- Department of Neurosurgery, University Hospital of Larisa, Biopolis, 41110 Larissa, Greece
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A novel technique for monitoring of fast variations in brain oxygen tension using an uncoated fluorescence quenching probe (Foxy AL-300). J Neurosurg Anesthesiol 2012; 23:341-6. [PMID: 21897296 DOI: 10.1097/ana.0b013e31822cf893] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND A novel uncoated fluorescence quenching probe allows fast measurement of oxygen tension in vessels and tissue. The present study reports the first use of the technology for dual measurements of arterial (paO(2)) and brain tissue oxygen tension (ptiO(2)) during hypoxic challenge in a pig model. METHODS Eight pigs were anesthetized using fentanyl and propofol. Fluorescence quenching pO(2) probes (Foxy AL-300, Ocean Optics, Dunedin, FL) were placed in the ascending aorta (Foxy-paO(2)) and subcortically at 14 mm in brain tissue (Foxy-ptiO(2)). As reference, a clark-type electrode probe (Licox-ptiO(2)) was placed into brain tissue close to the Foxy probe (Licox, Integra Neurosciences, Plainsboro, NJ). Measurements were taken at baseline (FiO(2) 1.0), during episodes of apnea, and during recovery (FiO(2) 1.0). STATISTICS descriptive results. RESULTS Individual Foxy-paO(2), Foxy-ptiO(2), and Licox-ptiO(2) courses were related to episodes of apnea. The response time of the Foxy measurements was 10 Hz. Baseline values at FiO(2) 1.0 were Foxy-paO(2) 520±120 mm Hg, Foxy-ptiO(2) 62±24 mm Hg, and Licox-ptiO(2) 55±29 mm Hg; apnea values were Foxy-paO(2) 64±10 mm Hg, Foxy-ptiO(2) 37±12 mm Hg, and Licox-ptiO(2) 31±16 mm Hg; recovery values at FiO(2) 1.0 were Foxy-paO(2) 478±98 mm Hg, Foxy-ptiO(2) 78±26 mm Hg, and Licox-ptiO(2) 62±32 mm Hg. CONCLUSIONS The present study demonstrates the feasibility of pO(2) measurements in macrocirculation and cerebral microcirculation using a novel uncoated fluorescence quenching probe. The technology allows for real-time investigation of pO(2) changes at a temporal resolution of 0.05 to 10 Hz.
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Gallavardin T, Armagnat C, Maury O, Baldeck PL, Lindgren M, Monnereau C, Andraud C. An improved singlet oxygen sensitizer with two-photon absorption and emission in the biological transparency window as a result of ground state symmetry-breaking. Chem Commun (Camb) 2012; 48:1689-91. [DOI: 10.1039/c2cc15904j] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Liu S, Shah SJ, Wilmes LJ, Feiner J, Kodibagkar VD, Wendland MF, Mason RP, Hylton N, Hopf HW, Rollins MD. Quantitative tissue oxygen measurement in multiple organs using 19F MRI in a rat model. Magn Reson Med 2011; 66:1722-30. [PMID: 21688315 DOI: 10.1002/mrm.22968] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2010] [Revised: 02/24/2011] [Accepted: 03/23/2011] [Indexed: 11/10/2022]
Abstract
Measurement of individual organ tissue oxygen levels can provide information to help evaluate and optimize medical interventions in many areas including wound healing, resuscitation strategies, and cancer therapeutics. Echo planar (19) F MRI has previously focused on tumor oxygen measurement at low oxygen levels (pO(2)) <30 mmHg. It uses the linear relationship between spin-lattice relaxation rate (R(1)) of hexafluorobenzene (HFB) and pO(2). The feasibility of this technique for a wider range of pO(2) values and individual organ tissue pO(2) measurement was investigated in a rat model. Spin-lattice relaxation times (T(1) = 1/R(1)) of hexafluorobenzene were measured using (19) F saturation recovery echo planar imaging. Initial in vitro studies validated the linear relationship between R(1) and pO(2) from 0 to 760 mmHg oxygen partial pressure at 25, 37, and 41°C at 7 Tesla for hexafluorobenzene. In vivo experiments measured rat tissue oxygen (ptO2) levels of brain, kidney, liver, gut, muscle, and skin during inhalation of both 30 and 100% oxygen. All organ ptO(2) values significantly increased with hyperoxia (P < 0.001). This study demonstrates that (19) F MRI of hexafluorobenzene offers a feasible tool to measure regional ptO2 in vivo, and that hyperoxia significantly increases ptO2 of multiple organs in a rat model.
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Affiliation(s)
- Siyuan Liu
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, California 94143-0464, USA
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Park YH, Shui YB, Beebe DC. Comparison of two probe designs for determining intraocular oxygen distribution. Br J Ophthalmol 2010; 95:118-22. [PMID: 20870641 DOI: 10.1136/bjo.2010.186064] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
INTRODUCTION Alterations in intraocular oxygen levels are important contributors to, or indications of, ocular disease. Polarographic electrodes and fibre-optic sensors (optodes) have been used to measure oxygen and to map the distribution of oxygen in animal models and in human eyes. A recent study reported the use of a commercial electrode to compare oxygen distribution in the vitreous of patients undergoing vitrectomy related to central retinal vein occlusion, macular hole or preretinal membrane. The results of this study were at variance with previous measures of oxygen distribution in the human vitreous using polarographic or optical sensors. To resolve this discrepancy, the present study compared measurements made in vitro or in animal eyes, using the electrode employed in the previous study or a fibre-optic sensor of a different design. STUDY DESIGN Comparative in vitro and in vivo measurements. RESULTS In vitro, the two devices reported similar levels of oxygen, although the electrode consistently detected levels above the calculated values. In rabbit eyes, the electrode had a slow response time and was unable to detect oxygen gradients that were readily measured by the smaller optode. When the electrode was inserted into an eye of similar size to the human eye, the reference thermistor measured the temperature outside the eye, not in the vitreous. CONCLUSIONS The design of the electrode used in the previous study makes it unsuitable for measurements of oxygen distribution in the eye.
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Affiliation(s)
- Young-Hoon Park
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St Louis, Missouri, USA
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Li B, Freeman RD. Neurometabolic coupling in the lateral geniculate nucleus changes with extended age. J Neurophysiol 2010; 104:414-25. [PMID: 20463197 DOI: 10.1152/jn.00270.2010] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Attempts have been made in various studies to identify and trace changes in function in the aging visual system. Some results are conflicting and we report here a unique approach in an attempt to resolve selected issues. We have estimated neurometabolic coupling in the central visual pathway in young and old cats. Our technique provides high resolution simultaneous measurements of neuronal activity and changes in concentration of tissue oxygen in the thalamus of young and old cats. Following visual stimulation, we find shorter latency and time to peak in tissue oxygen responses in old compared with young animals. Estimates of local activity induced initial negative oxygen response show substantial reductions in older animals. Measurements of neural activity in the form of multiple unit activity are similar in the two age groups. To investigate the mechanisms underlying the changes in tissue oxygen response in older animals, we measured vascular capillary density and found it to be substantially lower in old than that in young animals. Together, these findings suggest that the changes in metabolic responses with age may be largely accounted for by alterations in the cerebral microvasculature rather than by changes in neural activity.
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Affiliation(s)
- Baowang Li
- Group in Vision Science, School of Optometry, Helen Wills Neurosciences Institute, University of California, Berkeley, California 94720-2020, USA
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Oxygen and steroid concentrations in preovulatory follicles of lactating dairy cows exposed to acute heat stress. Theriogenology 2008; 69:805-13. [DOI: 10.1016/j.theriogenology.2007.12.008] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2007] [Revised: 12/14/2007] [Accepted: 12/15/2007] [Indexed: 11/20/2022]
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Driessen B, Zarucco L, Gunther RA, Burns PM, Lamb SV, Vincent SE, Boston RA, Jahr JS, Cheung ATW. Effects of low-volume hemoglobin glutamer-200 versus normal saline and arginine vasopressin resuscitation on systemic and skeletal muscle blood flow and oxygenation in a canine hemorrhagic shock model. Crit Care Med 2007; 35:2101-9. [PMID: 17581486 DOI: 10.1097/01.ccm.0000277040.31978.3d] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE To test the hypothesis that low-volume resuscitation with hemoglobin glutamer-200 improves hemodynamic function and tissue oxygenation, whereas arginine vasopressin resuscitation improves blood pressures more than low-volume saline or hemoglobin glutamer infusion but compromises systemic and muscle blood flow and oxygenation. DESIGN Randomized laboratory investigation. SETTING University research facility. SUBJECTS Nineteen dogs. INTERVENTIONS Dogs were instrumented to determine heart rate; arterial, central venous, pulmonary arterial, and pulmonary arterial occlusion pressures; cardiac output; and quadriceps muscle blood flow and oxygen tension (PMo2). Total and plasma hemoglobin, oxygen content, lactate, pH, standard base excess, and arginine vasopressin levels were determined, and systemic oxygen delivery (Do2I) and extraction ratio were calculated. Measurements were made before and 30 mins following hemorrhage. Dogs were resuscitated over 60 mins with saline (8.5 mL/kg), arginine vasopressin (0.4 IU/kg bolus plus 0.08 IU x kg x min), or 1:1 diluted hemoglobin glutamer-200. Recordings were then repeated. Subsequently, animals received 30 mL/kg shed blood (60 mL x kg x hr), and recordings were repeated immediately and 1 hr later. MEASUREMENTS AND MAIN RESULTS Hemorrhage ( approximately 52 mL/kg) caused characteristic changes in hemodynamic, hematologic, systemic PMo2, and acid-base variables. Saline resuscitation increased both Do2I and muscle perfusion by 42% and 51%, while arginine vasopressin treatment reduced heart rate by 31% and increased mean arterial pressure by 22% but not cardiac output, Do2I, or muscle blood flow, resulting in a further decrease of PMo2 by 68% and worse metabolic acidosis. Hemoglobin glutamer-200 infusion caused systemic and pulmonary vasoconstriction, however, without deterioration of cardiac output, Do2I, muscle blood flow, or PMo2 despite lack of oxygen content increase. Blood transfusion restored most variables. CONCLUSIONS Low-volume crystalloid or hemoglobin glutamer-200 resuscitation posthemorrhage may improve (but not restore) macro- and microvascular functions and tissue oxygenation, while arginine vasopressin infusion may only improve blood pressures and result in lower overall systemic perfusion compared with low-volume saline or hemoglobin glutamer-200 treatment and worsening of anaerobic conditions in skeletal muscle.
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Affiliation(s)
- Bernd Driessen
- University of Pennsylvania, School of Veterinary Medicine, Department of Clinical Studies, Section of Critical Care, New Bolton Center, Kennett Square, PA, USA.
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Ehrismann D, Flashman E, Genn D, Mathioudakis N, Hewitson K, Ratcliffe P, Schofield C. Studies on the activity of the hypoxia-inducible-factor hydroxylases using an oxygen consumption assay. Biochem J 2007; 401:227-34. [PMID: 16952279 PMCID: PMC1698668 DOI: 10.1042/bj20061151] [Citation(s) in RCA: 180] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The activity and levels of the metazoan HIF (hypoxia-inducible factor) are regulated by its hydroxylation, catalysed by 2OG (2-oxoglutarate)- and Fe(II)-dependent dioxygenases. An oxygen consumption assay was developed and used to study the relationship between HIF hydroxylase activity and oxygen concentration for recombinant forms of two human HIF hydroxylases, PHD2 (prolyl hydroxylase domain-containing protein 2) and FIH (factor inhibiting HIF), and compared with two other 2OG-dependent dioxygenases. Although there are caveats on the absolute values, the apparent K(m) (oxygen) values for PHD2 and FIH were within the range observed for other 2OG oxygenases. Recombinant protein substrates were found to have lower apparent K(m) (oxygen) values compared with shorter synthetic peptides of HIF. The analyses also suggest that human PHD2 is selective for fragments of the C-terminal over the N-terminal oxygen-dependent degradation domain of HIF-1alpha. The present results, albeit obtained under non-physiological conditions, imply that the apparent K(m) (oxygen) values of the HIF hydroxylases enable them to act as oxygen sensors providing their in vivo capacity is appropriately matched to a hydroxylation-sensitive signalling pathway.
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Affiliation(s)
- Dominic Ehrismann
- *Chemistry Research Laboratory, Department of Chemistry and Oxford Centre for Molecular Sciences, University of Oxford, Oxford OXI 3TA, U.K
| | - Emily Flashman
- *Chemistry Research Laboratory, Department of Chemistry and Oxford Centre for Molecular Sciences, University of Oxford, Oxford OXI 3TA, U.K
| | - David N. Genn
- *Chemistry Research Laboratory, Department of Chemistry and Oxford Centre for Molecular Sciences, University of Oxford, Oxford OXI 3TA, U.K
| | - Nicolas Mathioudakis
- *Chemistry Research Laboratory, Department of Chemistry and Oxford Centre for Molecular Sciences, University of Oxford, Oxford OXI 3TA, U.K
| | - Kirsty S. Hewitson
- *Chemistry Research Laboratory, Department of Chemistry and Oxford Centre for Molecular Sciences, University of Oxford, Oxford OXI 3TA, U.K
| | - Peter J. Ratcliffe
- †The Henry Wellcome Building for Molecular Physiology, Roosevelt Drive, Oxford OX3 7BN, U.K
- Correspondence may be addressed to either of the authors (email and )
| | - Christopher J. Schofield
- *Chemistry Research Laboratory, Department of Chemistry and Oxford Centre for Molecular Sciences, University of Oxford, Oxford OXI 3TA, U.K
- Correspondence may be addressed to either of the authors (email and )
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Shen J, Liu S, Miyake M, Liu W, Pritchard A, Kao JPY, Rosen GM, Tong Y, Liu KJ. Use of 3-acetoxymethoxycarbonyl-2,2,5,5-tetramethyl-1-pyrrolidinyloxyl as an EPR oximetry probe: Potential for in vivo measurement of tissue oxygenation in mouse brain. Magn Reson Med 2006; 55:1433-40. [PMID: 16680679 DOI: 10.1002/mrm.20894] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Measurement of oxygen concentration and distribution in the brain is essential for understanding the pathophysiology of stroke. Low-frequency electron paramagnetic resonance (EPR) spectroscopy with a paramagnetic probe is an attractive imaging modality that potentially can be used to map O(2) concentration in the brain. We examined two nitroxides, 3-methoxycarbonyl-2,2,5,5-tetramethyl-1-pyrrolidinyloxyl [2] and 3-acetoxymethoxycarbonyl-2,2,5,5-tetramethyl-1-pyrrolidinyloxyl [3], as pro-imaging agents to deliver 3-carboxy-2,2,5,5-tetramethyl-1-pyrrolidinyloxyl [1] across the blood-brain barrier (BBB). In primary cultured neurons, nitroxide [3] but not [2] was hydrolyzed by intracellular esterases to [1], which, being anionic at physiologic pH, was well retained intracellularly. In contrast, [2] was not well retained by neurons. In vivo pharmacokinetic and pharmacodynamic studies in mice suggested that esterase-labile nitroxide [3] crossed the BBB, and was converted to [1] and retained. Retention occurred in brain tissue and not in the extensive vasculature, as evidenced by the fact that removal of blood by whole-body saline perfusion did not eliminate the nitroxide EPR signal from the brain. The EPR linewidths of [1] and [3] were more O(2)-sensitive than that of the commonly-used oximetry probe 4-oxo-2,2,6,6-tetramethylpiperidine-d(16)-1-(15)N-oxyl [4]. Moreover, we used [3] in vivo to estimate O(2) concentration in mouse brains. These results indicate that nitroxide [3] could be useful for mapping O(2) distribution in the brain following stroke.
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Affiliation(s)
- Jiangang Shen
- Center of Biomedical Research Excellence, College of Pharmacy, University of New Mexico, Albuquerque, 87131, USA
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Riha PD, Bruchey AK, Echevarria DJ, Gonzalez-Lima F. Memory facilitation by methylene blue: Dose-dependent effect on behavior and brain oxygen consumption. Eur J Pharmacol 2005; 511:151-8. [PMID: 15792783 DOI: 10.1016/j.ejphar.2005.02.001] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2004] [Revised: 01/28/2005] [Accepted: 02/01/2005] [Indexed: 11/22/2022]
Abstract
Methylene blue administered post-training improves memory retention in avoidance and appetitive tasks, and restores spatial memory impaired by an inhibitor of cytochrome oxidase. Methylene blue may improve memory retention by increasing brain oxygen utilization. We investigated which doses improve memory without nonspecific behavioral effects, and whether methylene blue enhances brain oxygen consumption. Different doses were evaluated 24 h after administration in wheel running, feeding, open field habituation and object recognition tests. The 1-10 mg/kg methylene blue-treated rats were not different from saline-treated rats in locomotion or feeding behavior. The 50-100 mg/kg doses decreased running wheel behavior. The 4 mg/kg dose improved behavioral habituation and object memory recognition. Dose-dependent effects of methylene blue on brain oxygen consumption revealed that low concentrations increased brain oxygen consumption in vitro and 24 h after in vivo administration. Therefore, methylene blue doses that increase brain oxygen consumption also facilitate memory retention.
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Affiliation(s)
- Penny D Riha
- Department of Psychology, University of Texas at Austin, TX 78712, USA
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Ragheb J, Buggy DJ. Tissue oxygen tension ( P T O2 ) in anaesthesia and perioperative medicine. Br J Anaesth 2004; 92:464-8. [PMID: 15013958 DOI: 10.1093/bja/aeh090] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Henning T, Kraus M, Brischwein M, Otto AM, Wolf B. Relevance of tumor microenvironment for progression, therapy and drug development. Anticancer Drugs 2004; 15:7-14. [PMID: 15090737 DOI: 10.1097/00001813-200401000-00002] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Tumor interstitium exhibits a microenvironment that differs from corresponding normal tissues. Tumor phenotype shows, for example, an elevated intracellular pH (pHi), a lowered extracellular pH (pHe), a low oxygen concentration and low glucose levels. These differences are caused by cell biological (so called intrinsic) factors, e.g. a higher acidification rate, as well as by more systemic (extrinsic) factors, e.g. poor tumor vascularization. They represent important factors for invasiveness, immune suppression and proliferation, and they imply possibilities for diagnosis, prognosis and therapy. We have developed an experimental data-based computer model, which has simulated the potential role of metabolic effects on tumor progression. We show an experiment on cellular metabolism demonstrating the immunosuppressive impact of low pHe on peripheral blood mononuclear cells. Finally, we review important findings on the tumor microenvironment leading to possibilities for therapy which are currently evolving and which promise higher effectiveness for cancer therapy.
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Affiliation(s)
- Tobias Henning
- Heinz-Nixdorf-Lehrstuhl für Medizinische Elektronik, Technische Universität München, München, Germany
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